WorldWideScience

Sample records for highly textured transition

  1. Transition Texture Synthesis

    Institute of Scientific and Technical Information of China (English)

    Yueh-Yi Lai; Wen-Kai Tai

    2008-01-01

    Synthesis of transition textures is essential for displaying visually acceptable appearances on a terrain. This investigation presents a modified method for synthesizing the transition texture to be tiled on a terrain. All transition pattern types are recognized for a number of input textures. The proposed modified patch-based sampling texture synthesis approach, using the extra feature map of the input source and target textures for patch matching, can synthesize any transition texture on a succession pattern by initializing the output texture using a portion of the source texture enclosed in a transition cut. The transition boundary is further enhanced to improve the visual effect by tracing out the integral texture elements. Either the Game of Life model or Wang tiles method are exploited to present a good-looking profile of successions on a terrain for tiling transition textures. Experimental results indicate that the proposed method requires few input textures, yet synthesizes numerous tileable transition textures, which are useful for obtaining a vivid appearance of a terrain.

  2. Magnetostructural transition and magnetocaloric effect in highly textured Ni-Mn-Sn alloy

    Science.gov (United States)

    Czaja, P.; Chulist, R.; Szczerba, M. J.; Przewoźnik, J.; Olejnik, E.; Chrobak, A.; Maziarz, W.; Cesari, E.

    2016-04-01

    Ni49.4Mn38.5Sn12.1 near single crystal was obtained by the Bridgman method. At room temperature, it consisted of a mixture of the parent austenite phase with the cubic L21 Heusler structure (ac = 5.984 Å) and modulated, tetragonal martensite phase 4M (at = 4.337 Å, ct = 5.655 Å). Under the application of a magnetic field, the specimen undergoes field induced reverse martensitic transformation, which combined with the Curie transition in austenite leads to the coexistence of direct and inverse magnetocaloric effects. The maximum entropy change at 280 K and under 5 T amounts to 3.4 J.kg-1.K-1 for the structural transition and at 316 K reaches -2.7 J.kg-1.K-1 for the magnetic transformation. The magnetic entropy change occurs over a wide temperature span leading to improved refrigerant capacity of 101 J.kg-1 (5 T). Hysteretic losses are considerably reduced, which is promising with respect to improved cyclic stability of such a material.

  3. Older people with dysphagia: transitioning to texture-modified food.

    Science.gov (United States)

    Ullrich, Sandra; Crichton, Jonathan

    Older people with dysphagia are at high risk of malnutrition. To maintain safe oral and nutritional intake, solid food may be texture-modified. Little is known about the transition experiences of older people who move from normal to texture-modified foods. The aim of this study was to describe residents' experiences as they transitioned from normal food to texture-modified food. The study used a qualitative descriptive design and individual interviews were conducted with a study group of 28 participants (residents, family members, nursing and care staff, and speech and language therapists). The interviews were thematically analysed. The findings suggest that transition creates the risk of distress, reducing eating to a matter of necessity and hunger, and that the process is perceived as abrupt, and characterised by lack of communication and awareness of the need for change. A key finding is that the language used during transition can be adversely affected by the management of risk. This language promotes a culture of care that emphasises the limitations of residents, reduces their motivation to eat and hinders the delivery of person-centred care. The findings suggest that care facilities for older people need to revisit their dysphagia management protocols to ensure that they support a person-centred approach for recipients of texture-modified food.

  4. Modeling texture transitions in cholesteric liquid crystal droplets

    Science.gov (United States)

    Selinger, Robin; Gimenez-Pinto, Vianney; Lu, Shin-Ying; Selinger, Jonathan; Konya, Andrew

    2012-02-01

    Cholesteric liquid crystals can be switched reversibly between planar and focal-conic textures, a property enabling their application in bistable displays, liquid crystal writing tablets, e-books, and color switching ``e-skins.'' To explore voltage-pulse induced switching in cholesteric droplets, we perform simulation studies of director dynamics in three dimensions. Electrostatics calculations are solved at each time step using an iterative relaxation method. We demonstrate that as expected, a low amplitude pulse drives the transition from planar to focal conic, while a high amplitude pulse drives the transition from focal conic back to the planar state. We use the model to explore the effects of droplet shape, aspect ratio, and anchoring conditions, with the goal of minimizing both response time and energy consumption.

  5. Wetting transitions on textured hydrophilic surfaces

    Science.gov (United States)

    Ishino, C.; Okumura, K.

    2008-04-01

    We consider the quasi-static energy of a drop on a textured hydrophilic surface, with taking the contact angle hysteresis (CAH) into account. We demonstrate how energy varies as the contact state changes from the Cassie state (in which air is trapped at the drop bottom) to the Wenzel state (in which liquid fills the texture at the drop bottom) assuming that the latter state nucleates from the center of the drop bottom. When the textured substrate is hydrophilic enough to allow spontaneous penetration of liquid film of the texture thickness, the present theory asserts that the drop develops into an experimentally observed state in which a drop looks like an egg fried without flipped over (sunny-side up) with a well-defined radius of “the egg yolk.” Otherwise, the final contact state of the drop becomes like a Wenzel state, but with the contact circle smaller than the original Wenzel state due to the CAH. We provide simple analytical estimations for the yolk radius of the “sunny-side-up” state and for the final radius of the contact circle of the pseudo-Wenzel state.

  6. The Infiltration Process and Texture Transition of 2D C/C Composites

    Institute of Scientific and Technical Information of China (English)

    Hejun Li; Guozhong Xu; Kezhi Li; Chuang Wang; Wei Li; Miaoling Li

    2009-01-01

    2D needle-punched fiber felt was infiltrated by a kind of rapid isothermal chemical vapor infiltration technique. The infiltration process and texture transition of the infiltrated C/C composites were investigated. The porosity and the variations of the cumulative pore volume were determined by mercury porosimetry. The texture of matrix carbon was studied under a polarized light microscope. The results show that the relative mass gain of the sample increases directly as the infiltration time at the initial stage until 20 h, and subsequently the increasing rate of the relative mass gain decreases gradually with the prolonging of infiltration time. Three layers of pyrocarbon were formed around fibers. Low-textured pyrocarbon was obtained at the initial stage. With the densification going on, high-textured pyrocarbon was formed on the surface of low-textured pyrocarbon. Then, low-textured pyrocarbon was produced again during the final stage of densification. The texture transition is ascribed to the variation of the ratio of cumulative inner surface area to volume of pores and the gas partial pressure in pores.

  7. Surface texture metrology for high precision surfaces

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Gasparin, Stefania; Tosello, Guido

    2010-01-01

    This paper introduces some of the challenges related to surface texture measurement of high precision surfaces. The paper is presenting two case studies related to polished tool surfaces and micro part surfaces. In both cases measuring instrumentation, measurement procedure and the measurement...

  8. Surface texture metrology for high precision surfaces

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Gasparin, Stefania; Tosello, Guido

    2010-01-01

    This paper introduces some of the challenges related to surface texture measurement of high precision surfaces. The paper is presenting two case studies related to polished tool surfaces and micro part surfaces. In both cases measuring instrumentation, measurement procedure and the measurement re...

  9. Transition from Cassie to impaled state during drop impact on groove-textured solid surfaces.

    Science.gov (United States)

    Vaikuntanathan, V; Sivakumar, D

    2014-05-07

    Liquid drops impacted on textured surfaces undergo a transition from the Cassie state characterized by the presence of air pockets inside the roughness valleys below the drop to an impaled state with at least one of the roughness valleys filled with drop liquid. This occurs when the drop impact velocity exceeds a particular value referred to as the critical impact velocity. The present study investigates such a transition process during water drop impact on surfaces textured with unidirectional parallel grooves referred to as groove-textured surfaces. The process of liquid impalement into a groove in the vicinity of drop impact through de-pinning of the three-phase contact line (TPCL) beneath the drop as well as the critical impact velocity were identified experimentally from high speed video recordings of water drop impact on six different groove-textured surfaces made from intrinsically hydrophilic (stainless steel) as well as intrinsically hydrophobic (PDMS and rough aluminum) materials. The surface energy of various 2-D configurations of liquid-vapor interface beneath the drop near the drop impact point was theoretically investigated to identify the locally stable configurations and establish a pathway for the liquid impalement process. A force balance analysis performed on the liquid-vapor interface configuration just prior to TPCL de-pinning provided an expression for the critical drop impact velocity, Uo,cr, beyond which the drop state transitions from the Cassie to an impaled state. The theoretical model predicts that Uo,cr increases with the increase in pillar side angle, α, and intrinsic hydrophobicity whereas it decreases with the increase in groove top width, w, of the groove-textured surface. The quantitative predictions of the theoretical model were found to show good agreement with the experimental measurements of Uo,cr plotted against the surface texture geometry factor in our model, {tan(α/2)/w}(0.5).

  10. The activation energy for the FCC rolling texture transition and the activation energy for cross slip

    DEFF Research Database (Denmark)

    Leffers, T.; Pedersen, O.B.

    2002-01-01

    Already in 1968 one of the present authors determined the activation energy for the rolling-texture transition in Cu-5%Zn as a spin off of an investigation of the strain-rate dependence of the rolling texture. In the present work this determination of theactivation energy is explained and discussed...... (whereas very few details were given in the original work), and an error in the original work is corrected. The activation energy for the texture transition is compared with recent values for the activationenergy for cross slip derived from atomic-scale modelling. After adjustment to a stress level...... corresponding to the stress in Cu-5%Zn during heavy rolling the theoretical activation energy for cross slip is pretty close to the activation energy for thetexture transition. It is concluded that the texture transition is governed by cross slip, and the detailed mechanism is discussed....

  11. Textures in high purity aluminum foils and AA3004 sheets

    Institute of Scientific and Technical Information of China (English)

    肖亚庆; 张新明; 唐建国; 邓运来; 陈志永

    2003-01-01

    The simulation of rolling texture with "minimum shear principle" and the strengthening of cube recrystallization texture by inhomogeneous rolling, low strain deformation and multistage annealing, of the formation and evolution of texture in high purity Al were presented. The plastic anisotropy of crystalline materials were also summarized, including determination of the co-yield surfaces and condition of slipping as well as mechanical twinning, prediction of plastic anisotropy of deep drawing with modified Tuckers method, evolution of earing behavior of Al alloy sheets for deep drawing with CMTP approach, and construction of texture balance design and some technologies to suppress plastic anisotropy in practical production.

  12. Highly textured oxypnictide superconducting thin films on metal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Kazumasa, E-mail: iida@nuap.nagoya-u.ac.jp; Kurth, Fritz; Grinenko, Vadim; Hänisch, Jens [Institute for Metallic Materials, IFW Dresden, D-01171 Dresden (Germany); Chihara, Masashi; Sumiya, Naoki; Hatano, Takafumi; Ikuta, Hiroshi [Department of Crystalline Materials Science, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Ichinose, Ataru; Tsukada, Ichiro [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Matias, Vladimir [iBeam Materials, Inc., 2778A Agua Fria Street, Santa Fe, New Mexico 87507 (United States); Holzapfel, Bernhard [Institute for Technical Physics, Karlsruhe Institute of Technology, Hermann von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-27

    Highly textured NdFeAs(O,F) thin films have been grown on ion beam assisted deposition-MgO/Y{sub 2}O{sub 3}/Hastelloy substrates by molecular beam epitaxy. The oxypnictide coated conductors showed a superconducting transition temperature (T{sub c}) of 43 K with a self-field critical current density (J{sub c}) of 7.0×10{sup 4} A/cm{sup 2} at 5 K, more than 20 times higher than powder-in-tube processed SmFeAs(O,F) wires. Albeit higher T{sub c} as well as better crystalline quality than Co-doped BaFe{sub 2}As{sub 2} coated conductors, in-field J{sub c} of NdFeAs(O,F) was lower than that of Co-doped BaFe{sub 2}As{sub 2}. These results suggest that grain boundaries in oxypnictides reduce J{sub c} significantly compared to that in Co-doped BaFe{sub 2}As{sub 2} and, hence biaxial texture is necessary for high J{sub c.}.

  13. Evolution of recrystallization textures in high voltage aluminum capacitor foils

    Institute of Scientific and Technical Information of China (English)

    刘楚明; 张新明; 周鸿章; 陈志永; 邓运来; 周卓平

    2001-01-01

    The evolution of recrystallization textures in high voltage aluminum capacitor foils which are produced with a high level of cold reduction was tracked by analysis of microstructure and crystallographic texture. The results show that the deformation textures are mainly composed of S-orientation, Cu-orientation and a little Bs-orientation. During the low temperature stages of final annealing, the iron precipitates first along the sub-grain boundaries, and the Fe concentration in the matrix becomes low. Then, the cube grains nucleate preferably into the sub-grains. At high temperature stages, the cube nuclei can grow preferably because of their 40°〈111〉 orientation relationship to the S orientation, the main component of the rolling texture. Finally, the cube texture is sharply strong and the R orientation is very weak in the foils.

  14. High Rate Laser Pitting Technique for Solar Cell Texturing

    Energy Technology Data Exchange (ETDEWEB)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a

  15. Growth, dynamics, and texture modeling of the lamellar smectic-A liquid crystalline transition

    Science.gov (United States)

    Abukhdeir, Nasser Mohieddin

    2009-11-01

    This thesis is focused on the study of material transformations from the disordered state to the lamellar-ordered/smectic-A liquid crystalline state via multi-scale multi-transport modeling and simulation. This approach utilizes a high-order Landau-de Gennes phenomenological model able to bridge the gap between experimentally observed macro-scale phenomena and the nano-scale growth and structure inherent to liquid crystalline ordering. A unique feature of this simulation-based thesis is the direct verification of predictions with past experimental observations. In this context, the main contributions of this thesis work focuses on three experimental systems: free growth of an isolated domain, defect/texture formation, and the evolution of texture/defect interactions as the system approaches equilibrium. Simulation studies of free growth were first performed under conditions of deep undercooling, where non-isothermal effects can be neglected. The growth/shape kinetic evolution of initially textured and homogeneous spherulites growing into an unstable isotropic matrix phase was found, elucidating nano-scale morphology/texture processes and growth instabilities inaccessible experimentally. Undulation instabilities in growing smectic-A spherulites discovered in this work shed light on a possible mechanism for the formation of experimentally observed anisotropic "batonnet" morphologies and two-dimension focal conic defect structures. Recent experimental observations of growth kinetic phenomena of meta-stable nematic pre-ordering was studied, showing that the high-order model both predicts this phenomenon and explains the underlying mechanisms for experimentally determined morphological trends. A non-isothermal extension to the high-order model is derived and applied to study free growth under shallow undercooling conditions, where latent heat and anisotropic thermal diffusion are non-negligible. Growth laws, agreeing with experimental observations, are determined and

  16. Recrystallization Texture Transition in Fe-2.1 Wt Pct Si Steel by Different Cold Rolling Reduction

    Science.gov (United States)

    Shan, Ning; Sha, Yuhui; Zhang, Fang; Liu, Jinlong; Zuo, Liang

    2016-12-01

    The competition dependent on cold rolling reduction among main recrystallization texture components in Fe-2.1 wt pct Si sheets was investigated from the hot band characterized by strong Cube ({001}) at center layer and weak Goss ({110}) at quarter layer. The deformation and recrystallization textures through thickness were both analyzed by X-ray diffraction technique. Goss, Cube, and {111} components dominate the recrystallization texture in sequence with the cold rolling reduction increasing from 60 to 90 pct. This recrystallization texture transition with cold rolling reduction can be explained in terms of the number and nature of nucleation sites for various texture components. A variety of final recrystallization textures are proposed for non-oriented silicon steel by designing texture and microstructure of hot band and cold rolling reduction.

  17. Classification of high spatial resolution imagery using optimal Gabor-filters-based texture features

    Science.gov (United States)

    Zhao, Yindi; Wu, Bo

    2007-06-01

    Texture analysis has received great attention in the interpretation of high-resolution satellite images. This paper aims to find optimal filters for discriminating between residential areas and other land cover types in high spatial resolution satellite imagery. Moreover, in order to reduce the blurring border effect, inherent in texture analysis and which introduces important errors in the transition areas between different texture units, a classification procedure is designed for such high spatial resolution satellite images as follows. Firstly, residential areas are detected using Gabor texture features, and two clusters, one a residential area and the other not, are detected using the fuzzy C-Means algorithm, in the frequency space based on Gabor filters. Sequentially, a mask is generated to eliminate residential areas so that other land-cover types would be classified accurately, and not interfered with the spectrally heterogeneous residential areas. Afterwards, other objects are classified using spectral features by the MAP (maximum a posterior) - ICM (iterated conditional mode) classification algorithm designed to enforce the spatial constraints into classification. Experimental results on high spatial resolution remote sensing data confirm that the proposed algorithm provide remarkably better detection accuracy than conventional approaches in terms of both objective measurements and visual evaluation.

  18. Soft matter in hard confinement: phase transition thermodynamics, structure, texture, diffusion and flow in nanoporous media.

    Science.gov (United States)

    Huber, Patrick

    2015-03-18

    Spatial confinement in nanoporous media affects the structure, thermodynamics and mobility of molecular soft matter often markedly. This article reviews thermodynamic equilibrium phenomena, such as physisorption, capillary condensation, crystallisation, self-diffusion, and structural phase transitions as well as selected aspects of the emerging field of spatially confined, non-equilibrium physics, i.e. the rheology of liquids, capillarity-driven flow phenomena, and imbibition front broadening in nanoporous materials. The observations in the nanoscale systems are related to the corresponding bulk phenomenologies. The complexity of the confined molecular species is varied from simple building blocks, like noble gas atoms, normal alkanes and alcohols to liquid crystals, polymers, ionic liquids, proteins and water. Mostly, experiments with mesoporous solids of alumina, gold, carbon, silica, and silicon with pore diameters ranging from a few up to 50 nm are presented. The observed peculiarities of nanopore-confined condensed matter are also discussed with regard to applications. A particular emphasis is put on texture formation upon crystallisation in nanoporous media, a topic both of high fundamental interest and of increasing nanotechnological importance, e.g. for the synthesis of organic/inorganic hybrid materials by melt infiltration, the usage of nanoporous solids in crystal nucleation or in template-assisted electrochemical deposition of nano structures.

  19. Simulations of in situ x-ray diffraction from uniaxially compressed highly textured polycrystalline targets

    Energy Technology Data Exchange (ETDEWEB)

    McGonegle, David, E-mail: d.mcgonegle1@physics.ox.ac.uk; Wark, Justin S.; Higginbotham, Andrew [Department of Physics, Clarendon Laboratory University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Milathianaki, Despina [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Remington, Bruce A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-08-14

    A growing number of shock compression experiments, especially those involving laser compression, are taking advantage of in situ x-ray diffraction as a tool to interrogate structure and microstructure evolution. Although these experiments are becoming increasingly sophisticated, there has been little work on exploiting the textured nature of polycrystalline targets to gain information on sample response. Here, we describe how to generate simulated x-ray diffraction patterns from materials with an arbitrary texture function subject to a general deformation gradient. We will present simulations of Debye-Scherrer x-ray diffraction from highly textured polycrystalline targets that have been subjected to uniaxial compression, as may occur under planar shock conditions. In particular, we study samples with a fibre texture, and find that the azimuthal dependence of the diffraction patterns contains information that, in principle, affords discrimination between a number of similar shock-deformation mechanisms. For certain cases, we compare our method with results obtained by taking the Fourier transform of the atomic positions calculated by classical molecular dynamics simulations. Illustrative results are presented for the shock-induced α–ϵ phase transition in iron, the α–ω transition in titanium and deformation due to twinning in tantalum that is initially preferentially textured along [001] and [011]. The simulations are relevant to experiments that can now be performed using 4th generation light sources, where single-shot x-ray diffraction patterns from crystals compressed via laser-ablation can be obtained on timescales shorter than a phonon period.

  20. HIGH AND LOW RESOLUTION TEXTURED MODELS OF COMPLEX ARCHITECTURAL SURFACES

    Directory of Open Access Journals (Sweden)

    E. K. Stathopoulou

    2012-09-01

    Full Text Available During the recent years it has become obvious that 3D technology, applied mainly with the use of terrestrial laser scanners (TLS is the most suitable technique for the complete geometric documentation of complex objects, whether they are monuments or architectural constructions in general. However, it is rather a challenging task to convert an acquired point cloud into a realistic 3D polygonal model that can simultaneously satisfy high resolution modeling and visualization demands. The aim of the visualization of a simple or complex object is to create a 3D model that best describes the reality within the computer environment. This paper is dedicated especially in the visualization of a complex object's 3D model, through high, as well as low resolution textured models. The object of interest for this study was the Almoina (Romanesque Door of the Cathedral of Valencia in Spain.

  1. High and Low Resolution Textured Models of Complex Architectural Surfaces

    Science.gov (United States)

    Stathopoulou, E. K.; Valanis, A.; Lerma, J. L.; Georgopoulos, A.

    2011-09-01

    During the recent years it has become obvious that 3D technology, applied mainly with the use of terrestrial laser scanners (TLS) is the most suitable technique for the complete geometric documentation of complex objects, whether they are monuments or architectural constructions in general. However, it is rather a challenging task to convert an acquired point cloud into a realistic 3D polygonal model that can simultaneously satisfy high resolution modeling and visualization demands. The aim of the visualization of a simple or complex object is to create a 3D model that best describes the reality within the computer environment. This paper is dedicated especially in the visualization of a complex object's 3D model, through high, as well as low resolution textured models. The object of interest for this study was the Almoina (Romanesque) Door of the Cathedral of Valencia in Spain.

  2. ''Textural analysis of multiparametric MRI detects transition zone prostate cancer''

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, Harbir S.; Johnston, Edward W.; Taylor, Stuart A.; Halligan, Steve [Centre for Medical Imaging, University College London, London (United Kingdom); University College London Hospitals NHS Foundation Trust, London (United Kingdom); Benigno, Salvatore; Dikaios, Nikos [Centre for Medical Imaging, University College London, London (United Kingdom); Ganeshan, Balaji [Institute of Nuclear Medicine, University College London, University College Hospital, London (United Kingdom); Allen, Clare; Kirkham, Alex [University College London Hospitals NHS Foundation Trust, London (United Kingdom); Groves, Ashley M. [University College London Hospitals NHS Foundation Trust, London (United Kingdom); Institute of Nuclear Medicine, University College London, University College Hospital, London (United Kingdom); Ahmed, Hashim U.; Emberton, Mark [University College London Hospitals NHS Foundation Trust, London (United Kingdom); University College London, Research Department of Urology, London (United Kingdom); Punwani, Shonit [Centre for Medical Imaging, University College London, London (United Kingdom); University College London Hospitals NHS Foundation Trust, London (United Kingdom); Centre for Medical Imaging, University College London and University College London Hospitals NIHR Biomedical Research Centre, London (United Kingdom)

    2017-06-15

    To evaluate multiparametric-MRI (mpMRI) derived histogram textural-analysis parameters for detection of transition zone (TZ) prostatic tumour. Sixty-seven consecutive men with suspected prostate cancer underwent 1.5T mpMRI prior to template-mapping-biopsy (TPM). Twenty-six men had 'significant' TZ tumour. Two radiologists in consensus matched TPM to the single axial slice best depicting tumour, or largest TZ diameter for those with benign histology, to define single-slice whole TZ-regions-of-interest (ROIs). Textural-parameter differences between single-slice whole TZ-ROI containing significant tumour versus benign/insignificant tumour were analysed using Mann Whitney U test. Diagnostic accuracy was assessed by receiver operating characteristic area under curve (ROC-AUC) analysis cross-validated with leave-one-out (LOO) analysis. ADC kurtosis was significantly lower (p < 0.001) in TZ containing significant tumour with ROC-AUC 0.80 (LOO-AUC 0.78); the difference became non-significant following exclusion of significant tumour from single-slice whole TZ-ROI (p = 0.23). T1-entropy was significantly lower (p = 0.004) in TZ containing significant tumour with ROC-AUC 0.70 (LOO-AUC 0.66) and was unaffected by excluding significant tumour from TZ-ROI (p = 0.004). Combining these parameters yielded ROC-AUC 0.86 (LOO-AUC 0.83). Textural features of the whole prostate TZ can discriminate significant prostatic cancer through reduced kurtosis of the ADC-histogram where significant tumour is included in TZ-ROI and reduced T1 entropy independent of tumour inclusion. (orig.)

  3. Nano-textured high sensitivity ion sensitive field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Hajmirzaheydarali, M.; Sadeghipari, M.; Akbari, M.; Shahsafi, A.; Mohajerzadeh, S., E-mail: mohajer@ut.ac.ir [Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)

    2016-02-07

    Nano-textured gate engineered ion sensitive field effect transistors (ISFETs), suitable for high sensitivity pH sensors, have been realized. Utilizing a mask-less deep reactive ion etching results in ultra-fine poly-Si features on the gate of ISFET devices where spacing of the order of 10 nm and less is achieved. Incorporation of these nano-sized features on the gate is responsible for high sensitivities up to 400 mV/pH in contrast to conventional planar structures. The fabrication process for this transistor is inexpensive, and it is fully compatible with standard complementary metal oxide semiconductor fabrication procedure. A theoretical modeling has also been presented to predict the extension of the diffuse layer into the electrolyte solution for highly featured structures and to correlate this extension with the high sensitivity of the device. The observed ultra-fine features by means of scanning electron microscopy and transmission electron microscopy tools corroborate the theoretical prediction.

  4. Texture classification of vegetation cover in high altitude wetlands zone

    Science.gov (United States)

    Wentao, Zou; Bingfang, Wu; Hongbo, Ju; Hua, Liu

    2014-03-01

    The aim of this study was to investigate the utility of datasets composed of texture measures and other features for the classification of vegetation cover, specifically wetlands. QUEST decision tree classifier was applied to a SPOT-5 image sub-scene covering the typical wetlands area in Three River Sources region in Qinghai province, China. The dataset used for the classification comprised of: (1) spectral data and the components of principal component analysis; (2) texture measures derived from pixel basis; (3) DEM and other ancillary data covering the research area. Image textures is an important characteristic of remote sensing images; it can represent spatial variations with spectral brightness in digital numbers. When the spectral information is not enough to separate the different land covers, the texture information can be used to increase the classification accuracy. The texture measures used in this study were calculated from GLCM (Gray level Co-occurrence Matrix); eight frequently used measures were chosen to conduct the classification procedure. The results showed that variance, mean and entropy calculated by GLCM with a 9*9 size window were effective in distinguishing different vegetation types in wetlands zone. The overall accuracy of this method was 84.19% and the Kappa coefficient was 0.8261. The result indicated that the introduction of texture measures can improve the overall accuracy by 12.05% and the overall kappa coefficient by 0.1407 compared with the result using spectral and ancillary data.

  5. Deposition of highly textured AlN thin films by reactive high power impulse magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Milena A. [Department of Solid State Electronics, Ångström Laboratory, Uppsala University, Box 534, SE-752 21 Uppsala, Sweden and School of Electrical and Computer Engineering, University of Campinas, CEP 13.083-852 Campinas-SP (Brazil); Törndahl, Tobias; Katardjiev, Ilia; Kubart, Tomas, E-mail: tomas.kubart@angstrom.uu.se [Department of Solid State Electronics, Ångström Laboratory, Uppsala University, Box 534, SE-752 21 Uppsala (Sweden)

    2015-03-15

    Aluminum nitride thin films were deposited by reactive high power impulse magnetron sputtering (HiPIMS) and pulsed direct-current on Si (100) and textured Mo substrates, where the same deposition conditions were used for both techniques. The films were characterized by x-ray diffraction and atomic force microscopy. The results show a pronounced improvement in the AlN crystalline texture for all films deposited by HiPIMS on Si. Already at room temperature, the HiPIMS films exhibited a strong preferred (002) orientation and at 400 °C, no contributions from other orientations were detected. Despite the low film thickness of only 200 nm, an ω-scan full width at half maximum value of 5.1° was achieved on Si. The results are attributed to the high ionization of sputtered material achieved in HiPIMS. On textured Mo, there was no significant difference between the deposition techniques.

  6. Textural and morphological studies of transition metal doped SBA-15 by co-condensation method

    Indian Academy of Sciences (India)

    P H K Charan; G Ranga Rao

    2015-05-01

    The 3d transition metals were incorporated into SBA-15 matrix by co-condensation synthesis method. Very low concentrations of metals were introduced into silica framework by maintaining the metal to silica ratio in the synthesis gel at 0.01. The difference in hydrolysis rates of metal and silica precursors have led to textural modifications while demonstrating the structural integrity akin to pristine SBA-15. The physicochemical properties obtained offer some insights into the P123 micelle aggregation and mechanism of formation of silica network in the presence of metal salts under similar synthesis conditions of pure SBA-15. The metal doping into SBA-15 leads to increased pore diameters. Higher lattice constants (a0) observed in these samples are attributed to the increased pore wall thickness. The significant retention of the hexagonal mesostructure seen in LXRD indicates diminutive influence of metal salts at lower concentrations.Macroscopic morphologies studied by SEM show the formation of spheres along with conventional fibre-like rods.

  7. High Tc YBCO superconductor deposited on biaxially textured Ni substrate

    Science.gov (United States)

    Budai, John D.; Christen, David K.; Goyal, Amit; He, Qing; Kroeger, Donald M.; Lee, Dominic F.; List, III, Frederick A.; Norton, David P.; Paranthaman, Mariappan; Sales, Brian C.; Specht, Eliot D.

    1999-01-01

    A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.

  8. Growth of (100)-highly textured BaBiO{sub 3} thin films on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires (Argentina); Marchini, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires (Argentina); Granell, P. [INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Golmar, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, 1650 San Martín, Buenos Aires (Argentina); Albornoz, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); and others

    2016-08-01

    We report on the growth and characterization of non-epitaxial but (100)-highly textured BaBiO{sub 3} thin films on silicon substrates. We have found the deposition conditions that optimize the texture, and show that the textured growth is favoured by the formation of a BaO layer at the first growth stages. X-ray diffraction Φ-scans, together with the observation that the same textured growth is found on films grown on Pt and SiO{sub 2} buffered Si, demonstrate the absence of epitaxy. Finally, we have shown that our (100)-oriented BaBiO{sub 3} films can be used as suitable buffers for the growth of textured heterostructures on silicon, which could facilitate the integration of potential devices with standard electronics. - Highlights: • BaBiO{sub 3} thin films were grown on Si substrates and characterized. • Films prepared using optimized conditions are highly textured in the (100) direction. • The absence of in-plane texture was demonstrated by X-ray diffraction. • Our films are suitable buffers for the growth of (100)-textured oxide heterostructures.

  9. An investigation on the role of texture evolution and ordered phase transition in soft magnetic properties of Fe-6.5 wt%Si electrical steel

    Science.gov (United States)

    Cai, Guojun; Li, Changsheng; Cai, Ban; Wang, Qiwen

    2017-05-01

    Fe-6.5 wt%Si electrical steel characterized with excellent soft magnetic properties such as almost zero magnetostriction, low eddy current and hysteresis losses characteristics has been widely applied in high frequency fields. In this work, the role of texture evolution and ordered phase transition in soft magnetic properties of annealed sheets was explored using EBSD, XRD and TEM. The results demonstrate that accompanied with the increase of annealing temperatures, an increase on the B8 is attributable to a contribution combining the sizes of recrystallization grains with APBs of ordered phases as pinning the migration of magnetic domain wall. Whereas B50 declines to a minimum value (1.479 T) and then increases to a certain value (1.695 T) due to different types and intensities of textures affecting on the magnetocrystalline anisotropy energy. Meanwhile, the dislocation density gradually decreases and corresponding to a gradual decline in the internal stress, which makes the coercive force (Hc) decrease monotonically.

  10. Multivariate Texture segmentation of high-resolution remotely sensed imagery for identification of fuzzy objects

    NARCIS (Netherlands)

    Lucieer, A.; Stein, A.; Fisher, P.

    2005-01-01

    In this study, a segmentation procedure is proposed, based on grey¿level and multivariate texture to extract spatial objects from an image scene. Object uncertainty was quantified to identify transitions zones of objects with indeterminate boundaries. The Local Binary Pattern (LBP) operator, modelli

  11. Textures and Properties of Hot Rolled High Strength Ti-IF Steels

    Institute of Scientific and Technical Information of China (English)

    GUO Yan-hui; WANG Zhao-dong; ZOU Wen-wen; LIU Xiang-hua; WANG Guo-dong

    2008-01-01

    The texture evolution in a high strength Ti-IF steel during the processing of hot rolling,cold rolling,and annealing is studied.For comparison,both ferrite rolling and austenite rolling are employed.It is found that the texture type is the.same after ferrite rolling and austenite rolling,but the texture intensity is much higher in the ferriterolled sample.Furthermore,texture characteristics at the surface are absolutely different from those at the mid-section in both ferrite rolled and austenite rolled samples,as well as under the cold rolled and annealed conditions.The shear texture {110} disappears and orientation rotates along {110} →{554}→{111}→{111}→{223} during cold rolling.Compared to the austenite rolled sample,the properties of the cold rolled and annealed sheet which is subjected to ferrite rolling are higher.

  12. Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

    Science.gov (United States)

    Ngo, Chi-Vinh; Chun, Doo-Man

    2017-07-01

    Recently, the fabrication of superhydrophobic metallic surfaces by means of pulsed laser texturing has been developed. After laser texturing, samples are typically chemically coated or aged in ambient air for a relatively long time of several weeks to achieve superhydrophobicity. To accelerate the wettability transition from hydrophilicity to superhydrophobicity without the use of additional chemical treatment, a simple annealing post process has been developed. In the present work, grid patterns were first fabricated on stainless steel by a nanosecond pulsed laser, then an additional low-temperature annealing post process at 100 °C was applied. The effect of 100-500 μm step size of the textured grid upon the wettability transition time was also investigated. The proposed post process reduced the transition time from a couple of months to within several hours. All samples showed superhydrophobicity with contact angles greater than 160° and sliding angles smaller than 10° except samples with 500 μm step size, and could be applied in several potential applications such as self-cleaning and control of water adhesion.

  13. High fidelity replication of surface texture and geometric form of a high aspect ratio aerodynamic test component

    Science.gov (United States)

    Walton, Karl; Fleming, Leigh; Goodhand, Martin; Racasan, Radu; Zeng, Wenhan

    2016-06-01

    This paper details, assesses and validates a technique for the replication of a titanium wind tunnel test aerofoil in polyurethane resin. Existing resin replication techniques are adapted to overcome the technical difficulties associated with casting a high aspect ratio component. The technique is shown to have high replication fidelity over all important length-scales. The blade chord was accurate to 0.02%, and the maximum blade thickness was accurate to 2.5%. Important spatial and amplitude areal surface texture parameter were accurate to within 2%. Compared to an existing similar system using correlation areal parameters the current technique is shown to have lower fidelity and this difference is discussed. The current technique was developed for the measurement of boundary layer flow ‘laminar to turbulent’ transition for gas turbine compressor blade profiles and this application is illustrated.

  14. Geochemical and Textural Evidence for Transitions in Degassing Regimes at Merapi Volcano, Java, Indonesia

    Science.gov (United States)

    Genareau, K. D.; Cronin, S. J.; Lube, G.

    2013-12-01

    Transitions in degassing regimes at erupting volcanoes can cause significant changes in magma rheology and the intensity of eruptive activity. The October/November 2010 events at Merapi Volcano, Java, Indonesia began with an intrusive stage (Phase 1), followed by an explosion on October 26th (Phase 2) that removed the pre-existing dome causing deadly pyroclastic density currents (PDCs). This led to rapid ascent of juvenile magma that progressively degassed and crystallized until a large-scale collapse (Phase 3) of the new lava dome on November 5th and associated explosions produced even larger PDCs, killed more citizens, and destroyed several more distal villages. PDC deposits from the two main surge events on October 26th and November 5th, in addition to tephras generated by intermediate explosions, were sampled from numerous locations on the edifice. Secondary ion mass spectrometer (SIMS) depth profiling analyses were performed on free feldspar phenocrysts from the PDC deposits to examine the behavior of volatile elements during the eruptive events of 2010. Phenocrysts were mounted in indium and depth profiled with an O2+ primary ion beam for 2-14 hours. Profiles encounter glass and groundmass on the surface of the crystals before the feldspar is reached, determined from the point at which the B/Si and F/Si signals fall below detection limits. For all samples, the H/Si signal decreases from the glass into the crystal, but the Li/Si signal behaves differently between samples from Phase 2 and Phase 3. In Phase 2 samples, Li/Si ratios are higher in the glass compared to the crystal, revealing a build-up of Li in the groundmass not observed in Phase 3 samples. These observations suggest that Li was able to successfully diffuse out of both the feldspar and the surrounding groundmass in the Phase 3 products, but remained trapped in the groundmass of the Phase 2 products. The build-up of Li in the groundmass, coupled with textural evidence of a late-stage vesiculation

  15. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  16. Highly textured Gd2Zr2O7 films grown on textured Ni-5 at.%W substrates by solution deposition route: Growth, texture evolution, and microstructure dependency

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; Napari, M.

    2012-01-01

    Growth, texture evolution and microstructure dependency of solution derived Gd2Zr2O7 films deposited on textured Ni-5 at.%W substrates have been extensively studied. Influence of processing parameters, in particular annealing temperature and dwell time, as well as thickness effect on film texture...... and morphology are investigated in details. It is found that a rotated cube-on-cube epitaxy of Gd2Zr2O7//NiW in-plane texture forms as soon as the (004) out-plane texture appears, implying that epitaxial growth dominates the crystallization processes. Thermal energy plays an important role in minimizing...... the difference of interfacial energy along two directions in the anisotropic metallic substrate. Growth of Gd2Zr2O7 films displays an ultrafast kinetics under optimized conditions. Independency of sharp epitaxial (004) and polycrystalline (222) orientation is revealed from further synchrotron diffraction studies...

  17. Change detection in high resolution SAR images based on multiscale texture features

    Science.gov (United States)

    Wen, Caihuan; Gao, Ziqiang

    2011-12-01

    This paper studied on change detection algorithm of high resolution (HR) Synthetic Aperture Radar (SAR) images based on multi-scale texture features. Firstly, preprocessed multi-temporal Terra-SAR images were decomposed by 2-D dual tree complex wavelet transform (DT-CWT), and multi-scale texture features were extracted from those images. Then, log-ratio operation was utilized to get difference images, and the Bayes minimum error theory was used to extract change information from difference images. Lastly, precision assessment was done. Meanwhile, we compared with the result of method based on texture features extracted from gray-level cooccurrence matrix (GLCM). We had a conclusion that, change detection algorithm based on multi-scale texture features has a great more improvement, which proves an effective method to change detect of high spatial resolution SAR images.

  18. Classification of High Resolution C-Band PolSAR Data on Polarimetric and Texture Features

    Science.gov (United States)

    Zhao, Lei; Chen, Erxue; Li, Zengyuan; Feng, Qi; Li, Lan

    2014-11-01

    PolSAR image classification is an important technique in the remote sensing area. For high resolution PolSAR image, polarimetric and texture features are equally important for the high resolution PolSAR image classification. The texture features are mainly extracted through Gray Level Co-occurrence Matrix (GLCM) method, but this method has some deficiencies. First, GLCM method can only work on gray-scale images; Secondly, the number of texture features extracted by GLCM method is generally up dozens, or even hundreds. Too many features may exist larger redundancy and will increase the complexity of classification. Therefore, this paper introduces a new texture feature factor-RK that derived from PolSAR image non-Gaussian statistic model.Using the domestic airborne C-band PolSAR image data, we completed classification combined the polarization and texture characteristics.The results showed that this new texture feature factor-RK can overcome the above drawbacks and can achieve same performance compared with GLCM method.

  19. Microstructure and texture development during high-strain torsion of NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Kloeden, B.

    2006-07-01

    In this study polycrystalline NiAl has been subjected to torsion deformation. The deformation, microstructure and texture development subject to the shear strain are studied by different techniques (Electron Back-Scatter and High Energy Synchrotron Radiation). Beside the development of microstructure and texture with shear strain, the effect of an initial texture as well as the deformation temperature on the development of texture and microstructure constitute an important part of this study. Therefore, samples with three different initial textures were deformed in the temperature range T=700 K-1300 K. The shear stress-shear strain curves are characterized by a peak at low strains, which is followed by softening and a steady state at high strains. Grain refinement takes place for all samples and the average grain size decreases with temperature. For temperatures T>1000 K, discontinuous dynamic recrystallization occurs, by which new grains form by nucleation and subsequent growth. The texture is characterized by two components, {l_brace}100{r_brace}<100> (cube,C) and {l_brace}110{r_brace}<100> (Goss,G). Torsional creep of NiAl is characterized by a stress exponent, which depends on temperature and an activation energy, which is stress dependent. The Swift effect, due to which samples change their axial dimension during torsion without applied axial stress, is observed for NiAl. (orig.)

  20. Adolescents Transitioning to High School.

    Science.gov (United States)

    Williams, Susan G; Langhinrichsen-Rohling, Jennifer; Wornell, Cory; Finnegan, Heather

    2017-01-01

    Adolescents transitioning to high school may be at greater risk of depression and suicide if they are victims of bullying behavior. This study explored sex differences in bullying victimization (physical, verbal/social, and cyberbullying) and the impact on depressive symptoms and suicidal behaviors in ninth-grade students ( N = 233). Females reported significantly more verbal/social and cyberbullying than male students. There were no significant sex differences in physical bullying; male students who reported physical bullying victimization were more likely to experience depressive symptoms. Verbal/social bullying predicted depressive symptoms in males and females. Females who reported being victims of cyberbullying were more likely to report depressive symptoms, suicide ideation, and suicide attempts. Eighteen students reported suicide attempts, and each also experienced verbal/social bullying. School nurses are positioned to reach out to transitioning students, screen for mental health issues, provide a safe place to talk about bullying experiences, and promote positive mental health.

  1. Local shear texture formation in adiabatic shear bands by high rate compression of high manganese TRIP steels

    Science.gov (United States)

    Li, J.; Yang, P.; Mao, W. M.; Cui, F. E.

    2015-04-01

    Local shear textures in ASBs of high manganese TRIP steels under high rate straining are determined and the influences of initial microstructure is analyzed using EBSD technique. It is seen that even at the presence of majority of two types of martensite before deformation, ASB is preferred to evolve in austenite, rather than in martenite, due to reverse transformation. Ultrafine grains of thress phases due to dynamic recrystallization are formed and all show shear textures. The less ε-martensite in ASB is distributed as islands and its preferred orientation can be found to originate from the variants in matrix. The grain orientation rotation around ASB in multi-phase alloy reveals significant influence of α'- martensite on texture in ASB. The mechanism of local texture formation in ASB of high manganese TRIP steel is proposed in terms of the interaction of early TRIP and later reverse transformation.

  2. A novel optical technique to characterize fiberization of textured vegetable proteins under high-moisture extrusion

    Science.gov (United States)

    Yao, Gang; Liu, Keshun; Hsieh, Fu-Hung

    2004-11-01

    There have been great interests in using twin-screw extruders under high moisture conditions to produce textured vegetable proteins. Unlike the low moisture extrusion counterpart, a product extruded under high moisture can have well-defined fiber orientation and bears a strong resemblance to muscle meat. The textural properties of such extruded products are important for consumer acceptance. In this study, we developed a novel fluorescence polarization based technique that measures the fiber formation of extruded protein products. The experimental results using our new technique showed good agreements with results obtained from visual inspection and digital imaging of the dissected samples. The new technique provides an in vivo and noninvasive approach to characterize the fiber formation of textured vegetable proteins under high moisture extrusion. It has a potential to be used as a real time monitoring tool in food extrusion studies.

  3. Surface Texturing Investigated for a High Solar Absorptance Low Infrared Emittance Solar Collector

    Science.gov (United States)

    Jaworske, Donald A.

    2001-01-01

    The objective of this work was to design, build, and vacuum test a high solar absorptance, low infrared emittance solar collector for heat engine and thermal switching applications. Mini-satellites proposed by the Applied Physics Laboratory for operation in environments that are subject to radiation threat may utilize a heat engine for power and a thermal bus for thermal control. To achieve this goal, a surface having high solar absorptance and low infrared emittance is needed. At the NASA Glenn Research Center, one concept being pursued to achieve this goal is texturing high thermal conductivity graphite epoxy composites using a directed atomic oxygen beam and then coating the textured surface with a reflective metallic coating. Coupons were successfully textured, coated, and evaluated. A variety of texturing conditions were explored, and textures were documented by scanning electron microscopy. Copper, gold, silver, iridium, and aluminum coatings were applied, and the highest solar absorptance to infrared emittance ratio was found to be 1.3. A full-sized solar collector was manufactured with this ratio, and the amount of heat collected was observed using an Inconel calorimeter installed in a bench-top vacuum chamber equipped with a solar simulator. Results to date indicate good heat flow through the system, with 9 W of heat flow measured by the calorimeter.

  4. Effect of fabric texture and material on perceived discomfort at high humidity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Rasmussen, Leif W.; Mackeprang, Jørgen

    1999-01-01

    This study investigated the effect of material (cotton/polyester) and texture (woven/knitted) of the inner layer of a clothing ensemble on human discomfort at high skin humidity. No clear effect on discomfort of material and texture could be detected. However, acceptability of skin humidity de......-crea-sed with increasing relative skin humidity. A model was developed that predicts the percentage of persons dissatisfied due to humid skin as a function of relative skin humidity. The model applies for woven and knitted cot-ton and polyester materials and for activity levels typical for office work. Even at very high...

  5. High-power piezoelectric characteristics of textured bismuth layer structured ferroelectric ceramics.

    Science.gov (United States)

    Ogawa, Hirozumi; Kawada, Shinichiro; Kimura, Masahiko; Shiratsuyu, Kousuke; Sakabe, Yukio

    2007-12-01

    Abstract-The high-power piezoelectric characteristics in h001i oriented ceramics of bismuth layer structured ferroelectrics (BLSF), SrBi(2)Nb(2)O(9) (SBN), (Bi,La)(4)Ti(3)O(12) (BLT), and CaBi(4)Ti(4)O(15) (CBT), were studied by a constant voltage driving method. These textured ceramics were fabricated by a templated grain growth (TGG) method, and their Lotgering factors were 95%, 97%, and 99%, respectively. The vibration velocities of the longitudinal mode (33-mode) increased proportionally to an applied electric field up to 2.5 m/s in these textured BLSF ceramics, although, the vibration velocity of the 33-mode was saturated at more than 1.0 m/s in the Pb(Mn,Nb)O(3)-PZT ceramics. The resonant frequencies were constant up to the vibration velocity of 2.5 m/s in the SBN and CBT textured ceramics; however, the resonant frequency decreased with increasing over the vibration velocity of 1.5 m/s in the BLT textured ceramics. The dissipation power density of the BLT was almost the same as that of the Pb(Mn,Nb)O(3)-PZT ceramics. However, the dissipation power densities of the SBN and CBT were lower than those of the BLT and Pb(Mn,Nb)O(3)-PZT ceramics. The textured SBN and CBT ceramics are good candidates for high-power piezoelectric applications.

  6. Image Segmentation By Cluster Analysis Of High Resolution Textured SPOT Images

    Science.gov (United States)

    Slimani, M.; Roux, C.; Hillion, A.

    1986-04-01

    Textural analysis is now a commonly used technique in digital image processing. In this paper, we present an application of textural analysis to high resolution SPOT satellite images. The purpose of the methodology is to improve classification results, i.e. image segmentation in remote sensing. Remote sensing techniques, based on high resolution satellite data offer good perspectives for the cartography of littoral environment. Textural information contained in the pan-chromatic channel of ten meters resolution is introduced in order to separate different types of structures. The technique we used is based on statistical pattern recognition models and operates in two steps. A first step, features extraction, is derived by using a stepwise algorithm. Segmentation is then performed by cluster analysis using these extracted. features. The texture features are computed over the immediate neighborhood of the pixel using two methods : the cooccurence matrices method and the grey level difference statistics method. Image segmentation based only on texture features is then performed by pixel classification and finally discussed. In a future paper, we intend to compare the results with aerial data in view of the management of the littoral resources.

  7. A Color-Texture-Structure Descriptor for High-Resolution Satellite Image Classification

    Directory of Open Access Journals (Sweden)

    Huai Yu

    2016-03-01

    Full Text Available Scene classification plays an important role in understanding high-resolution satellite (HRS remotely sensed imagery. For remotely sensed scenes, both color information and texture information provide the discriminative ability in classification tasks. In recent years, substantial performance gains in HRS image classification have been reported in the literature. One branch of research combines multiple complementary features based on various aspects such as texture, color and structure. Two methods are commonly used to combine these features: early fusion and late fusion. In this paper, we propose combining the two methods under a tree of regions and present a new descriptor to encode color, texture and structure features using a hierarchical structure-Color Binary Partition Tree (CBPT, which we call the CTS descriptor. Specifically, we first build the hierarchical representation of HRS imagery using the CBPT. Then we quantize the texture and color features of dense regions. Next, we analyze and extract the co-occurrence patterns of regions based on the hierarchical structure. Finally, we encode local descriptors to obtain the final CTS descriptor and test its discriminative capability using object categorization and scene classification with HRS images. The proposed descriptor contains the spectral, textural and structural information of the HRS imagery and is also robust to changes in illuminant color, scale, orientation and contrast. The experimental results demonstrate that the proposed CTS descriptor achieves competitive classification results compared with state-of-the-art algorithms.

  8. Elasto-Plastic Behavior of High RRR Niobium: Effects of Crystallographic Texture, Microstructure and Hydrogen Concentration

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Myneni; S.R. Agnew

    2002-11-01

    Conventional assessments of the mechanical properties of polycrystalline high RRR niobium via tensile testing have revealed unusually low apparent Young's moduli and yield strength in annealed samples. These observations motivated the current investigation of a variety of possible contributors: crystallographic texture, grain size, and impurity concentration. It is shown that the crystallographic textures of a single lot of niobium are essentially unchanged by post-recrystallization anneals at temperatures up to 800 C. Ultrasonic measurements reveal that the elastic response is not degraded by annealing. Rather, the material's extremely low yield point gives the impression of a low elastic modulus during tensile testing.

  9. High coercivity through texture formation in SmCo5/Co multilayers

    Science.gov (United States)

    Sastry, P. U.; Mishra, P. K.; Krishnan, M.; Chowdhury, P.; Ravikumar, G.

    2013-02-01

    We have shown that high coercivity in SmCo5/Co multilayer exchange spring magnet can be obtained on silicon substrates as well. This is achieved by annealing the as-grown sample at an optimum temperature that favors texture formation. This compares well with multilayers grown on MgO substrates and post-annealed at the same temperature.

  10. Retrieval Using Texture Features in High Resolution Multi-spectral Satellite Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Newsam, S D; Kamath, C

    2004-01-22

    Texture features have long been used in remote sensing applications to represent and retrieve image regions similar to a query region. Various representations of texture have been proposed based on the Fourier power spectrum, spatial co-occurrence, wavelets, Gabor filters, etc. These representations vary in their computational complexity and their suitability for representing different region types. Much of the work done thus far has focused on panchromatic imagery at low to moderate spatial resolutions, such as images from Landsat 1-7 which have a resolution of 15-30 m/pixel, and from SPOT 1-5 which have a resolution of 2.5-20 m/pixel. However, it is not clear which texture representation works best for the new classes of high resolution panchromatic (60-100 cm/pixel) and multi-spectral (4 bands for red, green, blue, and near infra-red at 2.4-4 m/pixel) imagery. It is also not clear how the different spectral bands should be combined. In this paper, we investigate the retrieval performance of several different texture representations using multi-spectral satellite images from IKONOS. A query-by-example framework, along with a manually chosen ground truth dataset, allows different combinations of texture representations and spectral bands to be compared. We focus on the specific problem of retrieving inhabited regions from images of urban and rural scenes. Preliminary results show that (1) the use of all spectral bands improves the retrieval performance, and (2) co-occurrence, wavelet and Gabor texture features perform comparably.

  11. Event Texture Search for Phase Transitions in Pb+Pb Collisions

    CERN Document Server

    Bearden, I G; Bøggild, H; Boissevain, J; Conin, L; Dood, J; Erazmus, B; Esumi, S; Fabjan, B W; Ferenc, D; Fields, D E; Franz, A; Gaardhodje, J J; Hansen, A G; Hansen, O; Hardtke, D; Hecke, V H; Holzer, E B; Humanic, T J; Hummel, P; Jacak, V B; Jayanti, R; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M L; Letchouk, M; Ljubicic, A; Lörstad, B; Maeda, N; Matin, L; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Pothekin, M; Poulard, G; Reichhold, D; Sakaguchi, A; Schimdt-Sorensen, J; Simmon-Gillo, J; Sondheime, W; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K L; Xu, N; Zachary, D S

    2002-01-01

    NA44 uses a 512 channel Si pad array covering $1.5 <\\eta < 3.3$ to study charged hadron production in 158 A GeV Pb+Pb collisions at the CERN SPS. We apply a multiresolution analysis, based on a Discrete Wavelet Transformation, to probe the texture of particle distributions event-by-event, allowing simultaneous localization of features in space and scale. Scanning a broad range of multiplicities, we search for signals of clustering and of critical behavior in the power spectra of local density fluctuations. The data are compared with detailed simulations of detector response, using heavy ion event generators, and with a reference sample created via event mixing. An upper limit is set on the probability and magnitude of dynamical fluctuations.

  12. Fabrication and Piezoelectric Property of Highly Textured CaBi2Nb2O9 Ceramics by Tape Casting

    Science.gov (United States)

    Chen, Huanbei; Fu, Fang; Zhai, Jiwei

    2011-05-01

    Textured high-Curie-point lead-free piezoelectric ceramics, CaBi2Nb2O9 (CBN), were prepared by the tape casting method. Highly textured ceramics with a single phase and 95% Lotgering factor were obtained by the templated grain growth (TGG) technique. The textured CBN ceramics had a higher piezoelectric constant (d33 = 17.8 pC/N) than their non textured counterparts (d33 = 6.2 pC/N) prepared by a conventional solid-state sintering process. Furthermore, they had excellent thermostable of piezoelectric properties from room temperature to near Curie temperature. This type of textured CBN ceramic that can be prepared using the low-cost and scalable tape casting technique should be a promising candidate for high-temperature piezoelectric applications.

  13. Aircraft Detection in High-Resolution SAR Images Based on a Gradient Textural Saliency Map

    Science.gov (United States)

    Tan, Yihua; Li, Qingyun; Li, Yansheng; Tian, Jinwen

    2015-01-01

    This paper proposes a new automatic and adaptive aircraft target detection algorithm in high-resolution synthetic aperture radar (SAR) images of airport. The proposed method is based on gradient textural saliency map under the contextual cues of apron area. Firstly, the candidate regions with the possible existence of airport are detected from the apron area. Secondly, directional local gradient distribution detector is used to obtain a gradient textural saliency map in the favor of the candidate regions. In addition, the final targets will be detected by segmenting the saliency map using CFAR-type algorithm. The real high-resolution airborne SAR image data is used to verify the proposed algorithm. The results demonstrate that this algorithm can detect aircraft targets quickly and accurately, and decrease the false alarm rate. PMID:26378543

  14. Effect of creep and α-Zr ↔ (α + β)-Zr transition in Zr1Nb cladding on texture analyzed by neutron diffraction

    Science.gov (United States)

    Vetvicka, Ivan

    2014-10-01

    Zr1Nb alloy tubes used as nuclear fuel cladding in VVER reactors were deformed by isothermal creep under a temperature comprised between 350 °C and 850 °C and constant tensile stress of 5-200 MPa in axial direction (AD). Deformation texture was analyzed by neutron diffraction. Two types of texture were found. For the final type of texture, the test temperature was the decisive factor. Within the temperature range up to 600 °C, the effect of creep or plastic deformation dominates and the texture changes continuously with increasing deformation. The influence of the ratio of wall thickness reduction to diameter reduction (Rw/Rd) on texture originated by plastic deformation by compression of seamless tubes made of elemental zirconium or Zircaloy described by Tenckhoff (2005), was verified for textures formed by creep of cladding tubes made of Zr1Nb alloy (E110) by constant tensile stress at the 350-600 °C range. At 700 °C temperature or higher, the texture was formed mainly by reversible α-Zr ↔ (α + β)-Zr phase transition of significant proportion of zirconium crystals and the formation of a new texture was observed: The highest pole density in the TD have been observed for the pyramid (1 0 1bar 1) followed by the prism (1 0 1bar 0), which can be the effect of {1 1 2bar 1} twining. The prism (1 12bar 0) rotates preferentially perpendicular to AD, while the pole density of prism (1 0 1bar 0) is markedly low.

  15. Giant rotating magnetocaloric effect induced by highly texturing in polycrystalline DyNiSi compound.

    Science.gov (United States)

    Zhang, Hu; Li, YaWei; Liu, Enke; Ke, YaJiao; Jin, JinLing; Long, Yi; Shen, BaoGen

    2015-07-10

    Large rotating magnetocaloric effect (MCE) has been observed in some single crystals due to strong magnetocrystalline anisotropy. By utilizing the rotating MCE, a new type of rotary magnetic refrigerator can be constructed, which could be more simplified and efficient than the conventional one. However, compared with polycrystalline materials, the high cost and complexity of preparation for single crystals hinder the development of this novel magnetic refrigeration technology. For the first time, here we observe giant rotating MCE in textured DyNiSi polycrystalline material, which is larger than those of most rotating magnetic refrigerants reported so far. This result suggests that DyNiSi compound could be attractive candidate of magnetic refrigerants for novel rotary magnetic refrigerator. By considering the influence of demagnetization effect on MCE, the origin of large rotating MCE in textured DyNiSi is attributed to the coexistence of strong magnetocrystalline anisotropy and highly preferred orientation. Our study on textured DyNiSi not only provides a new magnetic refrigerant with large rotating MCE for low temperature magnetic refrigeration, but also opens a new way to exploit magnetic refrigeration materials with large rotating MCE, which will be highly beneficial to the development of rotating magnetic refrigeration technology.

  16. Structure and magnetic properties of highly textured nanocrystalline Mn–Zn ferrite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Jaison, E-mail: jaisonjosephp@gmail.com [Department of Physics, Goverment College, Khandola, Goa 403107 India (India); Tangsali, R.B. [Department of Physics, Goa University, Taleigao Plateau, Goa 403206 India (India); Pillai, V.P. Mahadevan [Department of Optoelectronics, University of Kerala,Thiruvananthapuram, Kerala 695581 India (India); Choudhary, R.J.; Phase, D.M.; Ganeshan, V. [UGC-DAE-CSR Indore, Madhya Pradesh 452017 India. (India)

    2015-01-01

    Nanoparticles of Mn{sub 0.2}Zn{sub 0.8}Fe{sub 2}O{sub 4} were chemically synthesized by co-precipitating the metal ions in aqueous solutions in a suitable alkaline medium. The identified XRD peaks confirm single phase spinal formation. The nanoparticle size authentication is carried out from XRD data using Debye Scherrer equation. Thin film fabricated from this nanomaterial by pulse laser deposition technique on quartz substrate was characterized using XRD and Raman spectroscopic techniques. XRD results revealed the formation of high degree of texture in the film. AFM analysis confirms nanogranular morphology and preferred directional growth. A high deposition pressure and the use of a laser plume confined to a small area for transportation of the target species created certain level of porosity in the deposited thin film. Magnetic property measurement of this highly textured nanocrystalline Mn–Zn ferrite thin film revealed enhancement in properties, which are explained on the basis of texture and surface features originated from film growth mechanism.

  17. Effects of high-pressure CO2 processing on flavor, texture, and color of foods.

    Science.gov (United States)

    Zhou, Linyan; Bi, Xiufang; Xu, Zenghui; Yang, Yingjie; Liao, Xiaojun

    2015-01-01

    High-pressure CO2 (HPCD) is a pasteurization method that inactivates microorganism and enzymes through molecular effects of CO2 under pressures below 50 MPa without exposing foods to adverse effects of heat. Thermal pasteurization can impart undesirable changes on organoleptic and nutritional quality of the foods, which can reduce sensory perception and consumer acceptance of the foods. As a novel nonthermal processing technique, HPCD does avoid drawbacks such as loss of flavor, denaturation of nutrients, production of side toxic reactions, as well as changes in physical, mechanical, and optical properties of the food materials involved in the processing. This review gives a survey and analysis of recent publications regarding the effects of HPCD on the flavor, texture and color of processed foods, and possible mechanisms explaining HPCD technique on the flavor, texture, and color of the foods were discussed.

  18. High-resolution texture imaging with hard synchrotron radiation in the moving area detector technique

    CERN Document Server

    Wcislak, L; Klein, H; Garbe, U; Schneider, J R

    2003-01-01

    The orientation distribution of crystallites in polycrystalline materials (called texture) is usually measured by polycrystal X-ray diffraction by 'step-scanning' the sample in angular intervals in the order of 1 deg. This technique is not suited to fully exploit the low angular divergence of hard synchrotron radiation in the order of 'milliradian'. Hence, step-scanning was replaced by a continuous 'sweeping' technique using a continuously shifted area detector. In order to avoid overlapping from different reflections (hkl) a Bragg-angle slit was introduced. The 'moving-detector' technique can be applied to obtain images of orientation as well as of location distributions of crystallites in polycrystalline samples. It is suitable for imaging continuous 'orientation density' distribution functions as well as of 'grain-resolved' textures. The excellent features of high-energy synchrotron radiation combined with the moving area detector technique will be illustrated with several examples including very sharp def...

  19. Physical and mechanical properties of highly textured polycrystalline Nb4AlC3 ceramic

    Directory of Open Access Journals (Sweden)

    Chunfeng Hu, Yoshio Sakka, Toshiyuki Nishimura, Shuqi Guo, Salvatore Grasso and Hidehiko Tanaka

    2011-01-01

    Full Text Available Highly textured polycrystalline Nb4AlC3 ceramic was fabricated by slip casting in a strong magnetic field followed by spark plasma sintering. Its Lotgering orientation factor was determined on the textured top and side surfaces as f(00l ~1.0 and f(hk0=0.36, respectively. This ceramic showed layered microstructure at the scales ranging from nanometers to millimeters. The as-prepared ceramic had excellent anisotropic physical properties. Along the c-axis direction, it showed higher hardness, bending strength, and fracture toughness of 7.0 GPa, 881 MPa and 14.1 MPa m1/2, respectively, whereas higher values of electrical conductivity (0.81×106 Ω−1 m−1, thermal conductivity (21.20 W m−1 K−1 and Young's modulus (365 GPa were obtained along the a- or b-axis direction.

  20. Impact of triacylglycerol composition on shear-induced textural changes in highly saturated fats.

    Science.gov (United States)

    Gregersen, Sandra B; Andersen, Morten D; Hammershøj, Marianne; Wiking, Lars

    2017-01-15

    This study demonstrates a strong interaction between triacylglycerol (TAG) composition and effects of shear rate on the microstructure and texture of fats. Cocoa butter alternatives with similar saturated fat content, but different major TAGs (PPO-, PSO-, SSO-, POP- and SOS-rich blends) were evaluated. Results show how shear can create a harder texture in fat blends based on symmetric monounsaturated TAGs (up to ∼200%), primarily due to reduction in crystal size, whereas shear has little effect on hardness of asymmetric monounsaturated TAGs. Such differences could not be ascribed to differences in the degree of supercooling, but was found to be a consequence of differences in the crystallisation behaviour of different TAGs. The fractal dimension was evaluated by dimensional detrended fluctuation analysis and Fourier transformation of microscopy images. However, the concept of fractal patterns was found to be insufficient to describe microstructural changes of fat blends with high solid fat content.

  1. Ultrafast laser direct hard-mask writing for high efficiency c-Si texture designs

    Science.gov (United States)

    Kumar, Kitty; Lee, Kenneth K. C.; Nogami, Jun; Herman, Peter R.; Kherani, Nazir P.

    2013-03-01

    This study reports a high-resolution hard-mask laser writing technique to facilitate the selective etching of crystalline silicon (c-Si) into an inverted-pyramidal texture with feature size and periodicity on the order of the wavelength which, thus, provides for both anti-reflection and effective light-trapping of infrared and visible light. The process also enables engineered positional placement of the inverted-pyramid thereby providing another parameter for optimal design of an optically efficient pattern. The proposed technique, a non-cleanroom process, is scalable for large area micro-fabrication of high-efficiency thin c-Si photovoltaics. Optical wave simulations suggest the fabricated textured surface with 1.3 μm inverted-pyramids and a single anti-reflective coating increases the relative energy conversion efficiency by 11% compared to the PERL-cell texture with 9 μm inverted pyramids on a 400 μm thick wafer. This efficiency gain is anticipated to improve further for thinner wafers due to enhanced diffractive light trapping effects.

  2. Ultrafast laser direct hard-mask writing for high efficiency c-Si texture designs

    Directory of Open Access Journals (Sweden)

    Nogami Jun

    2013-03-01

    Full Text Available This study reports a high-resolution hard-mask laser writing technique to facilitate the selective etching of crystalline silicon (c-Si into an inverted-pyramidal texture with feature size and periodicity on the order of the wavelength which, thus, provides for both anti-reflection and effective light-trapping of infrared and visible light. The process also enables engineered positional placement of the inverted-pyramid thereby providing another parameter for optimal design of an optically efficient pattern. The proposed technique, a non-cleanroom process, is scalable for large area micro-fabrication of high-efficiency thin c-Si photovoltaics. Optical wave simulations suggest the fabricated textured surface with 1.3 μm inverted-pyramids and a single anti-reflective coating increases the relative energy conversion efficiency by 11% compared to the PERL-cell texture with 9 μm inverted pyramids on a 400 μm thick wafer. This efficiency gain is anticipated to improve further for thinner wafers due to enhanced diffractive light trapping effects.

  3. Exploiting High Resolution Multi-Seasonal Textural Measures and Spectral Information for Reedbed Mapping

    Directory of Open Access Journals (Sweden)

    Alex Okiemute Onojeghuo

    2016-02-01

    Full Text Available Reedbeds across the UK are amongst the most important habitats for rare and endangered birds, wildlife and organisms. However, over the past century, this valued wetland habitat has experienced a drastic reduction in quality and spatial coverage due to pressures from human related activities. To this end, conservation organisations across the UK have been charged with the task of conserving and expanding this threatened habitat. With this backdrop, the study aimed to develop a methodology for accurate reedbed mapping through the combined use of multi-seasonal texture measures and spectral information contained in high resolution QuickBird satellite imagery. The key objectives were to determine the most effective single-date (autumn or summer and multi-seasonal QuickBird imagery suitable for reedbed mapping over the study area; to evaluate the effectiveness of combining multi-seasonal texture measures and spectral information for reedbed mapping using a variety of combinations; and to evaluate the most suitable classification technique for reedbed mapping from three selected classification techniques, namely maximum likelihood classifier, spectral angular mapper and artificial neural network. Using two selected grey-level co-occurrence textural measures (entropy and angular second moment, a series of experiments were conducted using varied combinations of single-date and multi-seasonal QuickBird imagery. Overall, the results indicate the multi-seasonal pansharpened multispectral bands (eight layers combined with all eight grey level co-occurrence matrix texture measures (entropy and angular second moment computed using windows 3 × 3 and 7 × 7 produced the optimal reedbed (76.5% and overall classification (78.1% accuracies using the maximum likelihood classifier technique. Using the optimal 16 layer multi-seasonal pansharpened multispectral and texture combined image dataset, a total reedbed area of 9.8 hectares was successfully mapped over the

  4. Conduit dynamics in transitional rhyolitic activity recorded by tuffisite vein textures from the 2008-2009 Chaitén eruption

    Directory of Open Access Journals (Sweden)

    Elodie eSaubin

    2016-05-01

    Full Text Available The mechanisms of hazardous silicic eruptions are controlled by complex, poorly-understood conduit processes. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. Intersection of foam domains by tuffisite veins appears critical to efficient outgassing. However, knowledge is currently lacking into textural heterogeneities within shallow conduits, their relationship with tuffisite vein propagation, and the implications for fragmentation and degassing processes. Similarly, the magmatic vesiculation response to upper conduit pressure perturbations, such as those related to the slip of dense magma plugs, remains largely undefined. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of various juvenile clast types.Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-350 metres depth in the conduit, permitting vertical gas and pyroclast mobility over hundreds of metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation

  5. Conduit dynamics in transitional rhyolitic activity recorded by tuffisite vein textures from the 2008-2009 Chaitén eruption

    Science.gov (United States)

    Saubin, Elodie; Tuffen, Hugh; Gurioli, Lucia; Owen, Jacqueline; Castro, Jonathan; Berlo, Kim; McGowan, Ellen; Schipper, C.; Wehbe, Katia

    2016-05-01

    The mechanisms of hazardous silicic eruptions are controlled by complex, poorly-understood conduit processes. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. Intersection of foam domains by tuffisite veins appears critical to efficient outgassing. However, knowledge is currently lacking into textural heterogeneities within shallow conduits, their relationship with tuffisite vein propagation, and the implications for fragmentation and degassing processes. Similarly, the magmatic vesiculation response to upper conduit pressure perturbations, such as those related to the slip of dense magma plugs, remains largely undefined. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of various juvenile clast types. Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-350 metres depth in the conduit, permitting vertical gas and pyroclast mobility over hundreds of metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation and sintering

  6. Conduit dynamics in transitional rhyolitic activity recorded by tuffisite vein textures from the 2008-2009 Chaitén eruption

    Science.gov (United States)

    Saubin, Elodie; Tuffen, Hugh; Gurioli, Lucia; Owen, Jacqueline; Castro, Jonathan; Berlo, Kim; McGowan, Ellen; Schipper, C. Ian; Wehbe, Katia

    2016-04-01

    Conduit processes govern the mechanisms of hazardous silicic eruptions, but our understanding of complex conduit behaviour is far from complete. Observations of recent Chilean rhyolite eruptions have revealed the importance of hybrid activity, involving simultaneous explosive and effusive emissions from a common vent[1]. Such behaviour hinges upon the ability of gas to decouple from magma in the shallow conduit. Tuffisite veins are increasingly suspected to be a key facilitator of outgassing, as they repeatedly provide a transient permeable escape route for volcanic gases. However, we have limited insights into the interactions between tuffisites and foams that appear critical to efficient outgassing[2], and into how heterogeneous conduit magma responds to pressure perturbations related to repeated disruption or slip of dense magma plugs. Here we provide a detailed characterization of an exceptionally large tuffisite vein within a rhyolitic obsidian bomb ejected during transitional explosive-effusive activity at volcán Chaitén, Chile in May 2008. Vein textures and chemistry provide a time-integrated record of the invasion of a dense upper conduit plug by deeper fragmented magma. Quantitative textural analysis reveals diverse vesiculation histories of varied juvenile clast types. Using vesicle size distributions, bubble number densities, zones of diffusive water depletion, and glass H2O concentrations, we propose a multi-step degassing/fragmentation history, spanning deep degassing to explosive bomb ejection. Rapid decompression events of ~3-4 MPa are associated with fragmentation of foam and dense magma at ~200-300 metres depth in the conduit, permitting vertical gas and pyroclast mobility over >100-200 metres. Permeable pathway occlusion in the dense conduit plug by pyroclast accumulation and sintering preceded ultimate bomb ejection, which triggered a final bubble nucleation event. Our results highlight how the vesiculation response of magma to decompression

  7. Formation of structure and crystallographic texture in Fe-50%Ni thin tapes under high magnetic field annealing

    Energy Technology Data Exchange (ETDEWEB)

    Gervasyeva, I.V., E-mail: gervasy@imp.uran.ru [Institute of Metal Physics, Ural Division, Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Beaugnon, E. [National Laboratory of High Magnetic Field, CNRS, B.P. 166 38042, Grenoble cedex 9 (France); Milyutin, V.A.; Volkova, E.G.; Rodionov, D.P.; Khlebnikova, Yu.V. [Institute of Metal Physics, Ural Division, Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Shishkin, D.A. [Institute of Metal Physics, Ural Division, Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Institute of Natural Sciences, Ural Federal University, 620083 Ekaterinburg (Russian Federation)

    2015-07-15

    For the first time the influence of a high direct current (DC) magnetic field on the structure and texture formation in tapes of Ni{sub 48.8}Fe{sub 51.2} alloy was investigated. Cube texture formation was studied in tapes after cold rolling to 98.8% and annealing in a high magnetic field up to 20 T. Samples were subjected to magnetic annealing below and above the Curie point. Structure and texture were studied using electron backscatter diffraction (EBSD) technique, transmission electron microscopy, and magnetic hysteresis loops measurements. The experiments show a significant increase of the {001}±10° volume fraction in the recrystallization texture with the main orientation {100}〈001〉, when the magnetic annealing is carried out at a temperature below the Curie point.

  8. High friction on ice provided by elastomeric fiber composites with textured surfaces

    Science.gov (United States)

    Rizvi, R.; Naguib, H.; Fernie, G.; Dutta, T.

    2015-03-01

    Two main applications requiring high friction on ice are automobile tires and footwear. The main motivation behind the use of soft rubbers in these applications is the relatively high friction force generated between a smooth rubber contacting smooth ice. Unfortunately, the friction force between rubber and ice is very low at temperatures near the melting point of ice and as a result we still experience automobile accidents and pedestrian slips and falls in the winter. Here, we report on a class of compliant fiber-composite materials with textured surfaces that provide outstanding coefficients of friction on wet ice. The fibrous composites consist of a hard glass-fiber phase reinforcing a compliant thermoplastic polyurethane matrix. The glass-fiber phase is textured such that it is aligned transversally and protruding out of the elastomer surface. Our analysis indicates that the exposed fiber phase exhibits a "micro-cleat" effect, allowing for it to fracture the ice and increase the interfacial contact area thereby requiring a high force to shear the interface.

  9. Detection of sub-kilometer craters in high resolution planetary images using shape and texture features

    Science.gov (United States)

    Bandeira, Lourenço; Ding, Wei; Stepinski, Tomasz F.

    2012-01-01

    Counting craters is a paramount tool of planetary analysis because it provides relative dating of planetary surfaces. Dating surfaces with high spatial resolution requires counting a very large number of small, sub-kilometer size craters. Exhaustive manual surveys of such craters over extensive regions are impractical, sparking interest in designing crater detection algorithms (CDAs). As a part of our effort to design a CDA, which is robust and practical for planetary research analysis, we propose a crater detection approach that utilizes both shape and texture features to identify efficiently sub-kilometer craters in high resolution panchromatic images. First, a mathematical morphology-based shape analysis is used to identify regions in an image that may contain craters; only those regions - crater candidates - are the subject of further processing. Second, image texture features in combination with the boosting ensemble supervised learning algorithm are used to accurately classify previously identified candidates into craters and non-craters. The design of the proposed CDA is described and its performance is evaluated using a high resolution image of Mars for which sub-kilometer craters have been manually identified. The overall detection rate of the proposed CDA is 81%, the branching factor is 0.14, and the overall quality factor is 72%. This performance is a significant improvement over the previous CDA based exclusively on the shape features. The combination of performance level and computational efficiency offered by this CDA makes it attractive for practical application.

  10. Changes in protein structures to improve the rheology and texture of reduced-fat sausages using high pressure processing.

    Science.gov (United States)

    Yang, Huijuan; Khan, Muhammad Ammar; Yu, Xiaobo; Zheng, Haibo; Han, Minyi; Xu, Xinglian; Zhou, Guanghong

    2016-11-01

    This study investigated the role of high-pressure processing (HPP) for improving the functional properties of meat batters and the textural properties of reduced-fat sausages. Application of 200MPa pressure at 10°C for 2min to pork batters containing various fat contents (0-30%) affected their rheological properties, cooking losses, color, textual properties and their protein imaging. The results revealed that both application of 200MPa and increasing fat content decreased cooking loss, as well as improved the textural and rheological properties. Cooking losses, texture and sensory evaluation of 200MPa treated sausages having 20% fat were similar to those of the 0.1MPa treated sausages having 30% fat. Principal component analysis revealed that certain quality attributes were affected differently by the levels of fat addition and by HPP. These findings indicated the potential of HPP for improving yield and texture of emulsion-type sausages having reduced fat contents.

  11. Classification of High Resolution C-Band PolSAR Data Based on Polarimetric and Texture Features

    Science.gov (United States)

    Zhao, Lei; Chen, Erxue; Li, Zengyuan; Feng, Qi; Li, Lan

    2014-11-01

    PolSAR image classification is an important technique in the remote sensing area. For high resolution PolSAR image, polarimetric and texture features are equally important for the high resolution PolSAR image classification. The texture features are mainly extracted through Gray Level Co-occurrence Matrix (GLCM) method, but this method has some deficiencies. First, GLCM method can only work on gray-scale images; Secondly, the number of texture features extracted by GLCM method is generally up dozens, or even hundreds. Too many features may exist larger redundancy and will increase the complexity of classification. Therefore, this paper introduces a new texture feature factor-RK that derived from PolSAR image non-Gaussian statistic model. Using the domestic airborne C-band PolSAR image data, we completed classification combined the polarization and texture characteristics. The results showed that this new texture feature factor-RK can overcome the above drawbacks and can achieve same performance compared with GLCM method.

  12. Micro-texture and Structure of High-pressure Quenched Graphite and Related Carbon Materials

    Science.gov (United States)

    Ohfuji, H.; Aibara, K.; Sumiya, H.; Irifune, T.

    2007-12-01

    There have been extensive studies in room-temperature compression of graphite and related carbon materials such as nanotubes and fullerene. Some reports claimed that the transformation of carbon hybridized state from sp2 to sp3 takes place under high pressure at room temperature, and the hardness of the quench products may be comparable to that of cubic diamond. Here, we investigated the micro-texture and structure involved in such high-pressure quenched carbon materials using high-resolution electron microscopy. High- pressure experiments were conducted on a variety of carbon materials including graphite (synthetic, highly- oriented sheet), single/multi-walled carbon nanotubes, amorphous carbons in a diamond anvil cell (DAC, with 250 μm culet non-beveled anvils) at room temperature. Pelletized sample was loaded into a 70 μm hall, drilled in a preindented Re gasket, without a pressure medium. The sample was compressed up to 70 ~ 90 GPa at room temperature, kept at the highest pressure at least overnight, and then decompressed. The pressure dependence of graphite E2g( G) Raman band at ~1580cm-1 was measured on compression and decompression. A1g( D) band, so called defect band at ~1350 cm-1, was also collected for the recovered products. The quenched materials were examined by high-resolution (HR) field emission (FE-) SEM and (HR)TEM. A focused ion beam (FIB) was employed to fabricate thin cross-sections of the samples. The most notable change in texture upon compression was observed in multi-walled carbon nanotube (MWNT); the elongated tubes were fragmented into short rods (ca. 100 - 300 nm in length and 80 - 100 nm in width, almost two times wider than that of the original MWNT). TEM observations showed that the short rod- shaped particles consist of piles of graphene shells (stacked walls of MWNT, characterized by (002) lattice fringes) which were significantly bent and fragmented. Some of those rod-shaped particles showed lattice fringes with an interlayer

  13. Enhanced electromechanical properties and phase transition temperatures in [001] textured Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary ceramics

    Science.gov (United States)

    Chang, Yunfei; Wu, Jie; Sun, Yuan; Zhang, Shantao; Wang, Xiaohui; Yang, Bin; Messing, Gary L.; Cao, Wenwu

    2015-08-01

    [001] oriented relaxor based ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ceramics were fabricated by templated grain growth. The effects of BaTiO3 template amount on the [001] orientation degree, microstructure, and resulting changes in dielectric, piezoelectric, and ferroelectric properties of PIN-PMN-PT were investigated. A high [001] texture fraction of 93% was achieved in the PIN-PMN-PT ceramics at 5 vol. % BaTiO3 template. Giant electromechanical properties (d33* = 1555 pC/N, d33 = 824 pC/N, and kp = 0.81) and high ferroelectric properties (Ec = 8.3 kV/cm and Pr = 31 μC/cm2) were obtained from those highly textured ceramics, which are much superior to those of randomly oriented counterpart. Furthermore, the textured ternary ceramics exhibited remarkably improved phase transition temperatures (Tr-t = 120 °C and Tc = 203 °C) compared with previously reported binary PMN-PT textured ceramics. The domain structure was characterized by piezoelectric force microscopy, and domain contribution to the enhanced piezoelectric response in the textured PIN-PMN-PT ceramics was analyzed. The high-quality textured ternary ceramics are very promising for new-generation electromechanical devices with high performance and wide temperature usage range.

  14. Effect of high-energy ball milling in the structural and textural properties of kaolinite

    Directory of Open Access Journals (Sweden)

    E. C. Leonel

    2014-06-01

    Full Text Available Through the process of high-energy ball milling it is possible to obtain solid materials with higher surface area and different particle sizes. These characteristics are very important for some application such as adsorption. Besides, applications of some clays depend on the functionalization which, for kaolinite, takes place in the aluminol groups. Modification in the structural and textural properties of kaolinite by high-energy milling can improve functionalization of kaolinite due to the exposure of aluminol groups. In this work studies were done on the influence of high-energy ball milling on the morphological properties of kaolinite, taking into account parameters such as filling of the miller, number of balls and amount of mass to be milled. Moreover, studies involving milling kinetics of purified kaolinite were carried out to verify modification in the morphology of kaolinite with milling time.

  15. Melting temperatures of MgO under high pressure by micro-texture analysis

    Science.gov (United States)

    Kimura, T.; Ohfuji, H.; Nishi, M.; Irifune, T.

    2017-06-01

    Periclase (MgO) is the second most abundant mineral after bridgmanite in the Earth's lower mantle, and its melting behaviour under pressure is important to constrain rheological properties and melting behaviours of the lower mantle materials. Significant discrepancies exist between the melting temperatures of MgO determined by laser-heated diamond anvil cell (LHDAC) and those based on dynamic compressions and theoretical predictions. Here we show the melting temperatures in earlier LHDAC experiments are underestimated due to misjudgment of melting, based on micro-texture observations of the quenched samples. The high melting temperatures of MgO suggest that the subducted cold slabs should have higher viscosities than previously thought, suggesting that the inter-connecting textural feature of MgO would not play important roles for the slab stagnation in the lower mantle. The present results also predict that the ultra-deep magmas produced in the lower mantle are peridotitic, which are stabilized near the core-mantle boundary.

  16. High friction and low wear properties of laser-textured ceramic surface under dry friction

    Science.gov (United States)

    Xing, Youqiang; Deng, Jianxin; Wu, Ze; Wu, Fengfang

    2017-08-01

    Two kinds of grooved textures with different spacing were fabricated on Al2O3/TiC ceramic surface by an Nd:YAG laser. The dry tribological properties of the textured samples were investigated by carrying out unidirectional rotary sliding friction and wear tests using a ball-on-disk tribometer. Results show that the laser textured samples exhibit higher friction coefficient and excellent wear resistance compared with the smooth sample under dry friction conditions. Furthermore, the texture morphology and spacing have a significant influence on the tribological properties. The sample with small texture spacing may be beneficial to increasing the friction coefficient, and the wavy-grooved sample exhibits the highest friction coefficient and shallowest wear depth. The increasing friction coefficient and anti-wear properties are attributed to the combined effects of the increased surface roughness, reduced real contact area, micro-cutting effect by the texture edges and entrapment of wear debris.

  17. High flux film and transition boiling

    Science.gov (United States)

    Witte, L. C.

    1993-02-01

    An investigation was conducted on the potential for altering the boiling curve through effects of high velocity and high subcooling. Experiments using water and Freon-113 flowing over cylindrical electrical heaters in crossflow were made to see how velocity and subcooling affect the boiling curve, especially the film and transition boiling regions. We sought subcooling levels down to near the freezing points of these two liquids to prove the concept that the critical heat flux and the minimum heat flux could be brought together, thereby averting the transition region altogether. Another emphasis was to gain insight into how the various boiling regions could be represented mathematically on various parts of the heating surface. Motivation for the research grew out of a realization that the effects of very high subcooling and velocity might be to avert the transition boiling altogether so that the unstable part of the boiling curve would not limit the application of high flux devices to temperatures less than the burnout temperatures. Summaries of results from the study are described. It shows that the potential for averting the transition region is good and points the way to further research that is needed to demonstrate the potential.

  18. Analysis of breast lesions on contrast-enhanced magnetic resonance images using high-dimensional texture features

    Science.gov (United States)

    Nagarajan, Mahesh B.; Huber, Markus B.; Schlossbauer, Thomas; Leinsinger, Gerda; Wismueller, Axel

    2010-03-01

    Haralick texture features derived from gray-level co-occurrence matrices (GLCM) were used to classify the character of suspicious breast lesions as benign or malignant on dynamic contrast-enhanced MRI studies. Lesions were identified and annotated by an experienced radiologist on 54 MRI exams of female patients where histopathological reports were available prior to this investigation. GLCMs were then extracted from these 2D regions of interest (ROI) for four principal directions (0°, 45°, 90° & 135°) and used to compute Haralick texture features. A fuzzy k-nearest neighbor (k- NN) classifier was optimized in ten-fold cross-validation for each texture feature and the classification performance was calculated on an independent test set as a function of area under the ROC curve. The lesion ROIs were characterized by texture feature vectors containing the Haralick feature values computed from each directional-GLCM; and the classifier results obtained were compared to a previously used approach where the directional-GLCMs were summed to a nondirectional GLCM which could further yield a set of texture feature values. The impact of varying the inter-pixel distance while generating the GLCMs on the classifier's performance was also investigated. Classifier's AUC was found to significantly increase when the high-dimensional texture feature vector approach was pursued, and when features derived from GLCMs generated using different inter-pixel distances were incorporated into the classification task. These results indicate that lesion character classification accuracy could be improved by retaining the texture features derived from the different directional GLCMs rather than combining these to yield a set of scalar feature values instead.

  19. Instrumental and Sensory Texture Attributes of High-Protein Nutrition Bars Formulated with Extruded Milk Protein Concentrate.

    Science.gov (United States)

    Banach, J C; Clark, S; Lamsal, B P

    2016-05-01

    Previous instrumental study of high-protein nutrition (HPN) bars formulated with extruded milk protein concentrate (MPC) indicated slower hardening compared to bars formulated with unmodified MPC. However, hardness, and its change during storage, insufficiently characterizes HPN bar texture. In this study, MPC80 was extruded at 2 different conditions and model HPN bars were prepared. A trained sensory panel and instrumental techniques were used to measure HPN bar firmness, crumbliness, fracturability, hardness, cohesiveness, and other attributes to characterize texture change during storage. Extrusion modification, storage temperature, and storage time significantly affected the instrumental and sensory panel measured texture attributes. The HPN bars became firmer and less cohesive during storage. When evaluated at the same storage conditions, the texture attributes of the HPN bars formulated with the different extrudates did not differ significantly from each other. However, textural differences were noted most of the time between the control and the HPN bars formulated with extruded MPC80. An adapted HPN bar crumbliness measurement technique produced results that were correlated with sensory panel measured crumbliness (r = 0.85) and cohesiveness (r = -0.84). Overall, the HPN bars formulated with extruded MPC80 were significantly softer, less crumbly, and more cohesive than the control during storage.

  20. Growth of highly textured PbTiO3 films on conductive substrate under hydrothermal conditions

    Science.gov (United States)

    Tang, Haixiong; Zhou, Zhi; Bowland, Christopher C.; Sodano, Henry A.

    2015-08-01

    Perovskite structure (ABO3) thin films have wide applications in electronic devices due to their unique properties, including high dielectric permittivity, ferroelectricity and piezoelectric coupling. Here, we report an approach to grow highly textured thick lead titanate (PbTiO3) films on conductive substrates by a two-step hydrothermal reaction. Initially, vertically aligned TiO2 nanowire arrays are grown on fluorine-doped tin oxide (FTO) coated glass, which act as template crystals for conversion to the perovskite structure. The PbTiO3 films are then converted from TiO2 NW arrays by diffusing Pb2+ ions into the template through a second hydrothermal reaction. The dielectric permittivity and piezoelectric coupling coefficient (d33) of the PbTiO3 films are as high as 795 at 1 kHz and 52 pm V-1, respectively. The reported process can also potentially be expanded for the assembly of other complex perovskite ATiO3 (A = Ba, Ca, Cd, etc) films by using the highly aligned TiO2 NW arrays as templates. Therefore, the approach introduced here opens up a new door to synthesize ferroelectric thin films on conductive substrates for application in sensors, actuators, and ultrasonic transducers that are important in various industrial and scientific areas.

  1. Creating textured substrate tapes of Cu-Fe alloys for second-generation high-temperature superconductors

    Science.gov (United States)

    Khlebnikova, Yu. V.; Gervas'eva, I. V.; Suaridze, T. R.; Rodionov, D. P.; Egorova, L. Yu.

    2014-10-01

    It is established that Cu-1.6 at % Fe alloy tapes obtained through cold rolling to 98.9% followed by recrystallization annealing possess a sharp cube texture, which opens prospects of using thin tapes of this alloy as substrates for second-generation high-temperature superconductors. The optimum regime of annealing is determined that allows an alloy with sharp biaxial texture containing more than 97% cubic grains to be obtained. The yield stress of a 90-μm-thick Cu-1.6 at % Fe alloy tape upon recrystallization annealing at 800°C for 1 h amounts to 78 MPa, which is about three times higher than the value for a pure copper tape with sharp cube texture.

  2. Effects of electric field on recrystallization texture evolution in cold-rolled high-purity aluminum sheet during annealing

    Institute of Scientific and Technical Information of China (English)

    WU Yan; ZHAO Xiang; HE Chang-shu; ZHAO Zhi-peng; ZUO Liang; C. ESLING

    2007-01-01

    The effects of an external DC (direct current) electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99% purity were investigated by means of X-ray diffraction techniques. The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200, 300 and 400 ℃, respectively with and without an external DC electric field of 800 V/mm. The results show that with DC electric field, the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.

  3. Perpendicular magnetic anisotropy, unconventional magnetization texture and extraordinary gradual spin reorientation transition of cobalt films in contact with graphene (Conference Presentation)

    Science.gov (United States)

    Rougemaille, Nicolas; Vu, Anh Duc; Chen, Gong; N'Diaye, Alpha T.; Schmid, Andreas K.; Coraux, Johann

    2016-10-01

    Owing to its peculiar electronic band structure, high carrier mobility and long spin diffusion length, graphene is a promising two-dimensional material for microelectronics and spintronics. Graphene also shows interesting magnetic properties when in contact with a ferromagnetic metal (FM). For instance, graphene carries a net magnetic moment when deposited on Fe/Ni(111), and a significant spin splitting can be induced in graphene due to proximity with a heavy element. While these results illustrate potential advantages of integrating graphene within a magnetic stack, the influence of graphene on the magnetic properties of a FM is still largely unexplored. In particular, non-magnetic overlayers generally affect the magnetic anisotropy energy (MAE) of thin layers, where interfaces play an important role. We can then wonder how an interface with graphene would influence the MAE of a thin FM film. Using spin-polarized low-energy electron microscopy, we study how a graphene overlayer affects the magnetic properties of atomically flat, nm-thick Co films grown on Ir(111). In this contribution, we report several astonishing magnetic properties of graphene-covered Co films: 1) Perpendicular magnetic anisotropy is favored over an unusually large thickness range, 2) Vectorial magnetic imaging reveals an extraordinarily gradual thickness-dependent spin reorientation transition (SRT), 3) During the SRT, cobalt films are characterized by an unconventional spin texture, 4) Spectroscopy measurements indicate that incident spin-polarized electrons do not suffer substantial spin-dependent collisions a few electron-Volts above the vacuum level. These properties strikingly differ from those of pristine cobalt films and could open new prospects in surface magnetism and spintronics.

  4. High-performance FeSe0.5Te0.5 thin films fabricated on less-well-textured flexible coated conductor templates

    Science.gov (United States)

    Xu, Zhongtang; Yuan, Pusheng; Ma, Yanwei; Cai, Chuanbing

    2017-03-01

    We report on the transport properties of FeSe0.5Te0.5 (FST) thin films fabricated on less-well-textured flexible coated conductor templates with LaMnO3 (LMO) as buffer layers using pulsed laser deposition. The LMO buffer layers exhibit large in-plane misalignment of ˜7.72°, which is unfavorable for cuprate-coated conductors due to the high grain boundaries. The FST thin films show a superconducting transition temperature of 16.8 K, higher than that of bulk materials due to the compressive strain between LMO and FST. Atomic force microscopy observations reveal that island-like features appear at the surfaces of both LMO and FST, confirming the island growth mode. A self-field transport critical-current density of up to 0.43 MA cm-2 at 4.2 K has been observed in FST thin films, which is much higher than that in powder-in-tube processed FST tapes. The films are capable of carrying current densities of over 105 A cm-2 in the whole applied magnetic field up to 9 T, showing great potential for high-field applications. The results indicate that, for FST, highly textured metal tapes are not needed to produce coated conductors with high performance, which is of great advantage over cuprate-coated conductors.

  5. Novel texturing method for sputtered zinc oxide films prepared at high deposition rate from ceramic tube targets

    Directory of Open Access Journals (Sweden)

    Hüpkes J.

    2011-10-01

    Full Text Available Sputtered and wet-chemically texture etched zinc oxide (ZnO films on glass substrates are regularly applied as transparent front contact in silicon based thin film solar cells. In this study, chemical wet etching in diluted hydrofluoric acid (HF and subsequently in diluted hydrochloric acid (HCl on aluminum doped zinc oxide (ZnO:Al films deposited by magnetron sputtering from ceramic tube targets at high discharge power (~10 kW/m target length is investigated. Films with thickness of around 800 nm were etched in diluted HCl acid and HF acid to achieve rough surface textures. It is found that the etching of the films in both etchants leads to different surface textures. A two steps etching process, which is especially favorable for films prepared at high deposition rate, was systematically studied. By etching first in diluted hydrofluoric acid (HF and subsequently in diluted hydrochloric acid (HCl these films are furnished with a surface texture which is characterized by craters with typical diameter of around 500 − 1000 nm. The resulting surface structure is comparable to etched films sputtered at low deposition rate, which had been demonstrated to be able to achieve high efficiencies in silicon thin film solar cells.

  6. Novel Texture-based Visualization Methods for High-dimensional Multi-field Data Sets

    Science.gov (United States)

    2013-07-06

    gradient image is multiplied with the first texture image, resulting in the second texture image appearing as “bumps”. The concept of Gestalt ...originates from the fine arts and expresses the notion that the whole contains more information than the parts. Perception of Gestalt is influenced by...We exploit Gestalt perception by using different masks, which subdivide the domain of two fields, and show for each section only one field. By

  7. Method for Fabricating Textured High-Haze ZnO:Al Transparent Conduction Oxide Films on Chemically Etched Glass Substrates.

    Science.gov (United States)

    Park, Hyeongsik; Nam, Sang-Hun; Shin, Myunghun; Ju, Minkyu; Lee, Youn-Jung; Yu, Jung-Hoon; Jung, Junhee; Kim, Sunbo; Ahn, Shihyun; Boo, Jin-Hyo; Yi, Junsin

    2016-05-01

    We developed a technique for forming textured aluminum-doped zinc oxide (ZnO:Al) transparent conductive oxide (TCO) films on glass substrates, which were etched using a mixture of hydrofluoric (HF) and hydrochloric (HCl) acids. The etching depth and surface roughness increased with an increase in the HF content and the etching time. The HF-based residues produced insoluble hexafluorosilicate anion- and oxide impurity-based semipermeable films, which reduced the etching rate. Using a small amount of HCl dissolved the Ca compounds, helping to fragment the semipermeable film. This formed random, complex structures on the glass substrates. The angled deposition of three layers of ZnO:Al led to the synthesis of multiscaled ZnO:Al textures on the glass substrates. The proposed approach resulted in textured ZnO:Al TCO films that exhibited high transmittance (-80%) and high haze (> 40%) values over wavelengths of 400-1000 nm, as well as low sheet resistances (ZnO:Al textured TCO films exhibited photocurrents and cell efficiencies that were 40% higher than those of cells with conventional TCO films.

  8. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou

    2014-04-01

    Full Text Available Laser texturing is a relatively new multiprocess technique that has been used for machining 3D curved surfaces; it is more flexible and efficient to create decorative texture on 3D curved surfaces of injection molds so as to improve the surface quality and achieve cosmetic surface of molded plastic parts. In this paper, a novel method of laser texturing 3D curved surface based on 3-axis galvanometer scanning unit has been presented to prevent the texturing of injection mold surface from much distortion which is often caused by traditional texturing processes. The novel method has been based on the computer texture mapping technology which has been developed and presented. The developed texture mapping algorithm includes surface triangulation, notations, distortion measurement, control, and numerical method. An interface of computer texture mapping has been built to implement the algorithm of texture mapping approach to controlled distortion rate of 3D texture math model from 2D original texture applied to curvature surface. Through a case study of laser texturing of a high curvature surface of injection mold of a mice top case, it shows that the novel method of laser texturing meets the quality standard of laser texturing of injection mold.

  9. Highly textured and transparent RF sputtered Eu2O3 doped ZnO films.

    Science.gov (United States)

    Sreedharan, Remadevi Sreeja; Ganesan, Vedachalaiyer; Sudarsanakumar, Chellappan Pillai; Bhavsar, Kaushalkumar; Prabhu, Radhakrishna; Mahadevan Pillai, Vellara Pappukutty Pillai

    2015-01-01

    Background : Zinc oxide (ZnO) is a wide, direct band gap II-VI oxide semiconductor. ZnO has large exciton binding energy at room temperature, and it is a good host material for obtaining visible and infrared emission of various rare-earth ions. Methods : Europium oxide (Eu2O3) doped ZnO films are prepared on quartz substrate using radio frequency (RF) magnetron sputtering with doping concentrations 0, 0.5, 1, 3 and 5 wt%. The films are annealed in air at a temperature of 773 K for 2 hours. The annealed films are characterized using X-ray diffraction (XRD), micro-Raman spectroscopy, atomic force microscopy, ultraviolet (UV)-visible spectroscopy and photoluminescence (PL) spectroscopy. Results : XRD patterns show that the films are highly c-axis oriented exhibiting hexagonalwurtzite structure of ZnO. Particle size calculations using Debye-Scherrer formula show that average crystalline size is in the range 15-22 nm showing the nanostructured nature of the films. The observation of low- and high-frequency E2 modes in the Raman spectra supports the hexagonal wurtzite structure of ZnO in the films. The surface morphology of the Eu2O3 doped films presents dense distribution of grains. The films show good transparency in the visible region. The band gaps of the films are evaluated using Tauc plot model. Optical constants such as refractive index, dielectric constant, loss factor, and so on are calculated using the transmittance data. The PL spectra show both UV and visible emissions. Conclusion : Highly textured, transparent, luminescent Eu2O3 doped ZnO films have been synthesized using RF magnetron sputtering. The good optical and structural properties and intense luminescence in the ultraviolet and visible regions from the films suggest their suitability for optoelectronic applications.

  10. Highly textured and transparent RF sputtered Eu2O3 doped ZnO films

    Directory of Open Access Journals (Sweden)

    Remadevi Sreeja Sreedharan

    2015-03-01

    Full Text Available Background: Zinc oxide (ZnO is a wide, direct band gap II-VI oxide semiconductor. ZnO has large exciton binding energy at room temperature, and it is a good host material for obtaining visible and infrared emission of various rare-earth ions. Methods: Europium oxide (Eu2O3 doped ZnO films are prepared on quartz substrate using radio frequency (RF magnetron sputtering with doping concentrations 0, 0.5, 1, 3 and 5 wt%. The films are annealed in air at a temperature of 773 K for 2 hours. The annealed films are characterized using X-ray diffraction (XRD, micro-Raman spectroscopy, atomic force microscopy, ultraviolet (UV-visible spectroscopy and photoluminescence (PL spectroscopy. Results: XRD patterns show that the films are highly c-axis oriented exhibiting hexagonalwurtzite structure of ZnO. Particle size calculations using Debye-Scherrer formula show that average crystalline size is in the range 15–22 nm showing the nanostructured nature of the films. The observation of low- and high-frequency E2 modes in the Raman spectra supports the hexagonal wurtzite structure of ZnO in the films. The surface morphology of the Eu2O3 doped films presents dense distribution of grains. The films show good transparency in the visible region. The band gaps of the films are evaluated using Tauc plot model. Optical constants such as refractive index, dielectric constant, loss factor, and so on are calculated using the transmittance data. The PL spectra show both UV and visible emissions. Conclusion: Highly textured, transparent, luminescent Eu2O3 doped ZnO films have been synthesized using RF magnetron sputtering. The good optical and structural properties and intense luminescence in the ultraviolet and visible regions from the films suggest their suitability for optoelectronic applications.

  11. Dependence of Deformation Twinning on Grain Orientation and Texture Evolution of High Manganese TWIP Steels at Different Deformation Temperatures%Dependence of Deformation Twinning on Grain Orientation and Texture Evolution of High Manganese TWIP Steels at Different Deformation Temperatures

    Institute of Scientific and Technical Information of China (English)

    FANG Xiu-hui; YANG Ping; LU Fa-yun; MENG Li

    2011-01-01

    Mechanical properties, microstructure and texture evolution were studied in two tensile-deformed high manganese TWIP steels at different temperatures. Special attention was paid to the effects of deformation tempera- ture and grain orientation on twinning behavior. The results showed that, at --70 ℃ and at room temperature, both twins and hexagonal martensite were found in a lower manganese steel of 26Mn. With deformation temperature ris- ing, twins became less and they disappeared at 500 ℃. Strong 〈111〉 texture appeared at 300 ℃, while it weakened at 500 ℃ due to the low strain rate and higher stacking fault energy. EBSD measurement revealed the dependence of deformation twinning on grain orientation at all test temperatures.

  12. Effect of texture and heat treatment on high temperature deformation of Zircaloy-2

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, E.F. (Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.); Choubey, R. (Combustion Engineering-Superheater Ltd., Moncton, New Brunswick (Canada)); Jonas, J.J. (McGill Univ., Montreal, Quebec (Canada). Dept. of Metallurgical Engineering)

    1984-09-01

    Cylindrical specimens machined from Zircaloy-2 plate have been tested under compression at 295, 675 and 1075 K. The plate was in three conditions (a) as hot rolled, (b) oil quenched from 1130 K and (c) oil quenched from 1340 K. These conditions simulate the structures in fuel cladding in regions near brazed spacers. The structures and crystallographic textures of the material in these conditions were characterized. Specimens with axes along the longitudinal, transverse and thickness directions were tested to determine the effect of temperature, texture and structure on the mechanical properties, particularly with respect to postulated LOCA conditions. The tests showed that (I) factors for mechanical anisotropy derived from room temperature results should be valid for LOCA analysis, (II) anisotropy factors from the results are consistent with about 67% prism and 33% basal slip in the early stages of deformation and (III) oil quenching from 1130 K changes the texture and strength in a minor way, while quenching from 1340 K (..beta.. phase) gives an almost random texture, little mechanical anisotropy and a small change in the average strength.

  13. The influence of rolling practice on notch toughness and texture development in high-strength linepipe

    Energy Technology Data Exchange (ETDEWEB)

    Baczynski, G.J.; Jonas, J.J.; Collins, L.E.

    1999-12-01

    The mechanical properties and notch toughnesses of an X80 linepipe steel were determined for various test directions in the plane of sheet that had been finish rolled in the {gamma} and in the intercritical ({alpha} + {gamma}) regions. The anisotropies of yield strength (YS) and of impact energy are correlated to the presence of various texture components, as detected by the use of an orientation distribution function (ODF) analysis. The final microstructures were similar and consisted of polygonal and acicular ferrite. The textures were also similar; however, after rolling in the ({alpha} + {gamma}) region, the intensity of the texture was significantly higher. These textures were mainly comprised of two fibers, the rolling direction (RD), {l{underscore}angle}110{r{underscore}angle}//RD, and the normal direction (ND), {l{underscore}angle}111{r{underscore}angle}//ND, fibers. The observations show that the RD fiber centered at {l{underscore}brace}112{r{underscore}brace}{l{underscore}angle}110{r{underscore}angle} and the {l{underscore}brace}10{r{underscore}brace}{l{underscore}angle}001{r{underscore}angle} orientation were responsible for the YS anisotropy. The relationships between notch toughness and texture were considered for the brittle or cleavage ({minus}196 C), mixed brittle-ductile ({minus}60 C), and ductile (room temperature (RT)) modes of fracture. This work shows that the anisotropy of impact energy associated with ductile fracture at the higher temperatures is caused by the {l{underscore}brace}112{r{underscore}brace}{l{underscore}angle}110{r{underscore}angle} component, and that the {l{underscore}brace}001{r{underscore}brace}{l{underscore}angle}110{r{underscore}angle} and {l{underscore}brace}110{r{underscore}brace}{l{underscore}angle}001{r{underscore}angle} components (if present) are responsible for the anisotropy of the impact energy associated with cleavage at low temperatures. The lack of anisotropy of the impact energy observed at {minus}196 C and

  14. TEXTURAL FRACTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Hynek Lauschmann

    2011-05-01

    Full Text Available The reconstitution of the history of a fatigue process is based on the knowledge of any correspondences between the morphology of the crack surface and the velocity of the crack growth (crack growth rate - CGR. The textural fractography is oriented to mezoscopic SEM magnifications (30 to 500x. Images contain complicated textures without distinct borders. The aim is to find any characteristics of this texture, which correlate with CGR. Pre-processing of images is necessary to obtain a homogeneous texture. Three methods of textural analysis have been developed and realized as computational programs: the method based on the spectral structure of the image, the method based on a Gibbs random field (GRF model, and the method based on the idealization of light objects into a fibre process. In order to extract and analyze the fibre process, special methods - tracing fibres and a database-oriented analysis of a fibre process - have been developed.

  15. Fabrication of high-aspect-ratio polymer microstructures and hierarchical textures using carbon nanotube composite master molds.

    Science.gov (United States)

    Copic, Davor; Park, Sei Jin; Tawfick, Sameh; De Volder, Michael F L; Hart, A John

    2011-05-21

    Scalable and cost effective patterning of polymer structures and their surface textures is essential to engineer material properties such as liquid wetting and dry adhesion, and to design artificial biological interfaces. Further, fabrication of high-aspect-ratio microstructures often requires controlled deep-etching methods or high-intensity exposure. We demonstrate that carbon nanotube (CNT) composites can be used as master molds for fabrication of high-aspect-ratio polymer microstructures having anisotropic nanoscale textures. The master molds are made by growth of vertically aligned CNT patterns, capillary densification of the CNTs using organic solvents, and capillary-driven infiltration of the CNT structures with SU-8. The composite master structures are then replicated in SU-8 using standard PDMS transfer molding methods. By this process, we fabricated a library of replicas including vertical micro-pillars, honeycomb lattices with sub-micron wall thickness and aspect ratios exceeding 50:1, and microwells with sloped sidewalls. This process enables batch manufacturing of polymer features that capture complex nanoscale shapes and textures, while requiring only optical lithography and conventional thermal processing.

  16. Pan-Tropical Forest Mapping by Exploiting Textures of Multi-Temporal High Resolution SAR Data

    Science.gov (United States)

    Knuth, R.; Eckardt, R.; Richter, N.; Schmullius, C.

    2012-12-01

    radar images were processed using an operational processing chain that includes radiometric transformation, noise reduction, and georeferencing of the SAR data. In places with pronounced topography both satellites were used as single pass interferometer to derive a digital surface model in order to perform an orthorectification followed by a topographic normalization of the SAR backscatter values. As prescribed by the FAO, the final segment-based classification algorithm was fed by multi-temporal backscatter information, a set of textural features, and information on the degree of coherence between the multi-temporal acquisitions. Validation with available high resolution optical imagery suggests that the produced forest maps possess an overall accuracy of 75 percent or higher.

  17. Textural performance of crosslinked or reduced-calcium milk protein ingredients in model high-protein nutrition bars.

    Science.gov (United States)

    Banach, J C; Clark, S; Metzger, L E; Lamsal, B P

    2016-08-01

    Transglutaminase (Tgase) crosslinking and calcium reduction were investigated as ways to improve the texture and storage stability of high-protein nutrition (HPN) bars formulated with milk protein concentrate (MPC) and micellar casein concentrate (MCC). The MPC and MCC crosslinked at none, low, and high levels, and a reduced-calcium MPC (RCMPC) were each formulated into model HPN bars. Hardness, crumbliness, moisture content, pH, color, and water activity of the HPN bars were measured during accelerated storage. The HPN bars prepared with MPC were harder and more cohesive than those prepared with MCC. Higher levels of Tgase crosslinking improved HPN bar cohesiveness and decreased hardening during storage. The RCMPC produced softer, yet crumblier HPN bars. Small textural differences were observed for the HPN bars formulated with the transglutaminase crosslinked proteins or RCMPC when compared with their respective controls. However, modification only slightly improved protein ingredient ability to slow hardening while balancing cohesion and likely requires further improvement for increased applicability in soft-texture HPN bars.

  18. Two-step preparation of laser-textured Ni/FTO bilayer composite films with high photoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Huang, Li-jing [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Ren, Nai-fei [Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd, Taixing 225400 (China)

    2015-08-15

    Highlights: • A two-step strategy was proposed to prepare laser-textured Ni/FTO composite films. • Ni/FTO film with a 10-nm-thick Ni layer (Ni{sub 10}/FTO film) had the best performance. • The Ni{sub 10}/FTO film underwent magnetic-field-assisted and -free laser irradiations. • All the magnetic laser-irradiated (MLI-NF) films were textured and annealed. • The MLI-NF film using a fluence of 1.0 J/cm{sup 2} showed the highest figure of merit. - Abstract: A two-step strategy, i.e. sputtering Ni layers on FTO glass combined with magnetic-field-assisted laser irradiation, was proposed to prepare laser-textured Ni/FTO bilayer composite films. By analyzing surface morphology, crystal structure and photoelectric properties of Ni/FTO films with different Ni layer thicknesses, the Ni/FTO film with a 10-nm-thick Ni layer (Ni{sub 10}/FTO film), which had the best overall photoelectric property, was chosen to undergo magnetic-field-assisted laser irradiation with different laser fluences. Magnetic-field-free laser irradiation of the Ni{sub 10}/FTO film was also carried out for comparison purpose. It was found that magnetic-field-assisted laser irradiation using a fluence of 1.0 J/cm{sup 2} was more effective for simultaneously achieving texturing and annealing, resulting in formation of ideal grating textures and significantly increased grain size. The corresponding film (MLI-NF1.0 film) showed the highest figure of merit of 22.8 × 10{sup −3} Ω{sup −1} compared to 13.1 × 10{sup −3} Ω{sup −1} of the FTO glass and 1.4 × 10{sup −3} Ω{sup −1} of the Ni{sub 10}/FTO film, suggesting that the two-step strategy is excellent for preparing textured Ni/FTO films with high photoelectric properties.

  19. Surface morphology of highly ordered nanotube formed and laser textured beta titanium alloys.

    Science.gov (United States)

    Kim, Jae-Un; Jeong, Yong-Hoon; Choe, Han-Cheol

    2013-03-01

    The aim of the present study is to produce and characterize a well-controlled surface texture on Ti-35Nb-xHf alloys to promote osseointegration. Ti-35Nb-xHf (x = 0, 3, 7 and 15 wt.%) alloys were prepared by arc melting and heat treated for 12 hr at 1000 degrees C in an argon atmosphere and then water quenching. For surface texturing, an amplified Ti: sapphire laser system was used for generating 184 femtosecond (FS, 10(-15) sec) laser pulses with the pulse energy over 30 mJ at a 1 kHz repetition rate with a central wavelength of 800 nm. The nanotube formation was achieved by anodizing a Ti-35Nb-xHf alloy in H3PO4 electrolytes containing 0.8 wt.% NaF at room temperature. The surface morphology of nano/micro structure will enhance osseointegration and cell adhesion.

  20. Probing the Nanodomain Origin and Phase Transition Mechanisms in (UnPoled PMN-PT Single Crystals and Textured Ceramics

    Directory of Open Access Journals (Sweden)

    Aneta Slodczyk

    2010-11-01

    Full Text Available Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−xPbMg1/3Nb2/3O3−xPbTiO3 solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6, determine the short range arrangement and the outstanding ferro- and piezoelectric properties.

  1. Arrested development - a comparative analysis of multilayer corona textures in high-grade metamorphic rocks

    Science.gov (United States)

    Ogilvie, Paula; Gibson, Roger L.

    2017-02-01

    Coronas, including symplectites, provide vital clues to the presence of arrested reaction and preservation of partial equilibrium in metamorphic and igneous rocks. Compositional zonation across such coronas is common, indicating the persistence of chemical potential gradients and incomplete equilibration. Major controls on corona mineralogy include prevailing pressure (P), temperature (T) and water activity (aH2O) during formation, reaction duration (t) single-stage or sequential corona layer growth; reactant bulk compositions (X) and the extent of metasomatic exchange with the surrounding rock; relative diffusion rates for major components; and/or contemporaneous deformation and strain. High-variance local equilibria in a corona and disequilibrium across the corona as a whole preclude the application of conventional thermobarometry when determining P-T conditions of corona formation, and zonation in phase composition across a corona should not be interpreted as a record of discrete P-T conditions during successive layer growth along the P-T path. Rather, the local equilibria between mineral pairs in corona layers more likely reflect compositional partitioning of the corona domain during steady-state growth at constant P and T. Corona formation in pelitic and mafic rocks requires relatively dry, residual bulk rock compositions. Since most melt is lost along the high-T prograde to peak segment of the P-T path, only a small fraction of melt is generally retained in the residual post-peak assemblage. Reduced melt volumes with cooling limit length scales of diffusion to the extent that diffusion-controlled corona growth occurs. On the prograde path, the low melt (or melt-absent) volumes required for diffusion-controlled corona growth are only commonly realized in mafic igneous rocks, owing to their intrinsic anhydrous bulk composition, and in dry, residual pelitic compositions that have lost melt in an earlier metamorphic event. Experimental work characterizing rate

  2. Three-dimensional analysis of vesicle and crystal fragment textures in pumice using high-resolution X-ray CT: Textural evidence of eruptive processes

    Science.gov (United States)

    Ketcham, R. A.; Gardner, J. E.; Abbott, S.

    2011-12-01

    Three-dimensional analysis of high-resolution X-ray computed tomographic (CT) imagery of pumice from Popocatépetl Volcano in central Mexico yields fresh insights into processes of vesicle formation and coalescence and crystal fragmentation that occur during explosive volcanism. Six ~2 cm pumice fragments of varying bulk vesicularity were imaged at ~20 μm resolution. Three-dimensional blob and fabric analysis quantitatively document textural features, and visualization facilitated contextualization of measurements and overall interpretation. Vesicles range in size from mm-scale to below the resolution of the scan data. By comparing the whole-sample 3D vesicle size distributions derived from CT with more detailed distributions from sub-volumes obtained by standard petrographic analysis, we can discern two distinct, roughly log-normal populations in each sample. Vesicles in all samples have preferred orientations, and fabric analysis based on the star volume distribution and displayed as 3D rose diagrams documents a range of preferred shapes from elongate to flattened. Aspect ratios range from 1 to 6, and converge to values of ~2-3 with increasing size. Surface to volume ratios show increasing departure from sphericity with increasing size, which is probably attributable in large part to irregular shapes caused by coalescence. The vesicle fabric was strongest in the highest-vesicularity sample. Some pumices showed evidence of welding or poor mixing between two or more differently devolatilized portions of melt. Interfaces are in some cases apparently welded, with low-vesicularity glass contact zones, and in others are simply sub-planar intersections between distinct glasses. In one instance of the latter, correlated vesicle and phenocryst orientations across both melt portions and not parallel to their interface suggests that their juxtaposition took place before final eruption, while there was still time for fabric development. The pumices show abundant evidence of

  3. Microstructural and Texture Development in Two Austenitic Steels with High-Manganese Content

    DEFF Research Database (Denmark)

    Bhattacharya, Basudev; Ray, Ranjit Kumar; Leffers, Torben

    2015-01-01

    Two austenitic steels, Fe-21.3Mn-3.44Si-3.74Al-0.5C and Fe-29.8Mn-2.96Si-2.73Al-0.52C, were subjected to cold rolling with 30 to 80 pct reduction with an increment of 10 pct and subsequently the development of their microstructures and textures were studied. The overall texture after 80 pct cold...... reduction was Brass type. A weak Copper component {112}〈111〉 was present at the early stage of deformation, which disappeared completely after 60 pct cold reduction. Extensive shear banding took place in both the steels, right from rather low cold rolling levels, which became more prominent at higher...... amounts of cold rolling. Formation of twin bands, along with cellular dislocation network, was observed in Steel A after 30 pct cold rolling. In case of Steel B, denser twin bands and dislocation cellular network were observed in early stage of deformation. After 80 pct cold reduction, the development...

  4. Gallery of melt textures developed in Westerly Granite during high-pressure triaxial friction experiments

    Science.gov (United States)

    Moore, Diane E.; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M.

    2016-09-23

    IntroductionMelting occurred during stick-slip faulting of granite blocks sheared at room-dry, room-temperature conditions in a triaxial apparatus at 200–400 megapascals (MPa) confining pressure. Petrographic examinations of melt textures focused largely on the 400-MPa run products. This report presents an overview of the petrographic data collected on those samples, followed by brief descriptions of annotated versions of all the images.Scanning electron microscope (SEM) images of the starting materials and the three examined 400-MPa samples are presented in this report. Secondary-electron (SE) and backscattered-electron (BSE) imaging techniques were used on different samples. The SE images look down on the sawcut surfaces, yielding topographic and three-dimensional textural information. The BSE imaging was done on samples cut to provide cross-sectional views of the glass-filled shear band (or zone) that developed along the sawcut. Brightness in the BSE images increases with increasing mean atomic number of the material. Additional chemical information about the quenched melt and adjoining minerals was obtained using the energy dispersive system of the SEM during BSE examinations. However, the very narrow shear-band thicknesses and common occurrence of very fine lamellar compositional layering limited the usefulness of this technique for estimating melt chemistry.

  5. Textured Nanoporous Mo:BiVO4 Photoanodes with High Charge Transport and Charge Transfer Quantum Efficiencies for Oxygen Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Vineet; Perkins, Craig L.; Lin, Qiyin; Law, Matt

    2016-04-01

    We have developed a simple spin coating method to make high-quality nanoporous photoelectrodes of monoclinic BiVO4 and studied the ability of these electrodes to transport photogenerated carriers to oxidize sulfite and water. Samples containing molybdenum and featuring [001] out-of-plane crystallographic texture show a photocurrent and external quantum efficiency (EQE) for sulfite oxidation as high as 3.1 mA cm-2 and 60%, respectively, at 1.23 V versus reversible hydrogen electrode. By using an optical model of the electrode stack to accurately determine the fraction of electrode absorptance due to the BiVO4 active layer, we estimate that on average 70 +/- 5% of all photogenerated carriers escape recombination. A comparison of internal quantum efficiency as a function of film processing, illumination direction, and film thickness shows that electron transport is efficient and hole transport limits the photocurrent (hole diffusion length <40 nm). We find that Mo addition primarily improves electron transport and texturing mostly improves hole transport. Mo enhances electron transport by thinning the surface depletion layer or passivating traps and recombination centers at grain boundaries and interfaces, while improved hole transport in textured films may result from more efficient lateral hole extraction due to the texturing itself or the reduced density of deep gap states observed in photoemission measurements. Photoemission data also reveal that the films have bismuth-rich, vanadium- and oxygen-deficient surface layers, while ion scattering spectroscopy indicates a Bi-V-O surface termination. Without added catalysts, the plain BiVO4 electrodes oxidized water with an initial photocurrent and peak EQE of 1.7 mA cm-2 and 30%, respectively, which equates to a hole transfer efficiency to water of >64% at 1.23 V. The electrodes quickly photocorrode during water oxidation but show good stability during sulfite oxidation and indefinite stability in the dark. By improving

  6. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.;

    2012-01-01

    Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period...

  7. Geomorphological diversity of Dong-Sha Atoll based on spectrum and texture analysis in high resolution remote sensing imagery

    Science.gov (United States)

    Chen, Jianyu; Mao, Zhihua; He, Xianqiang

    2009-01-01

    Coral reefs are complex marine ecosystems that are constructed and maintained by biological communities that thrive in tropical oceans. The Dong-Sha Atoll is located at the northern continental margin of the South China Sea. It has being abused by destructive activity of human being and natural event during recent decades. Remote sensing offers a powerful tool for studying coral reef geomorphology and is the most cost-effective approach for large-scale reef survey. In this paper, the high-resolution Quickbird2 imageries which covered the full atoll are used to categorize the current distribution of coral reefs geomorphological structure therein with the auxiliary SPOT5 and ASTER imageries. Spectral and texture analysis are used to distinguish the geomorphological diversity during data processing. The Gray Level Co-occurrence Matrices is adopted for texture feature extraction and atoll geomorphology mapping in the high-resolution pan-color image of Quickbird2. Quickbird2 is considered as the most appropriate image source for coral reefs studies. In the Dong-Sha Atoll, various dynamical geomorphologic units are developed according to wave energy zones. There the reef frame types are classified to 3 different types according as its diversity at the image. The radial structure system is the most characteristic and from high resolution imagery we can distinguish the discrepancy between them.

  8. Creation of a sharp cube texture in ribbon substrates of Cu-40% Ni- M ( M = Fe, Cr, V) ternary alloys for high-temperature second generation superconductors

    Science.gov (United States)

    Khlebnikova, Yu. V.; Rodionov, D. P.; Gervas'eva, I. V.; Suaridze, T. R.; Egorova, L. Yu.

    2016-11-01

    The structure and the process of texture formation in ribbons made of Cu-Ni- M ( M = Fe, Cr, V) ternary alloys have been studied upon cold rolling deformation to a degree of 99% and subsequent recrystallization annealing. The possibility of obtaining a perfect cube texture in a thin ribbon made of copper-nickel-based ternary alloys with additives of iron, chromium, and vanadium has been shown, which opens the prospects of the use of these alloys as substrates in the technology of production of tapes of high-temperature second-generation superconductors. Optimal annealing regimes have been determined, which make it possible to obtain a perfect biaxial texture close to single-crystalline one with the content of cube-oriented grains {001}±10° more than 99% on the surface of the textured ribbon.

  9. Micro-texturing into DLC/diamond coated molds and dies via high density oxygen plasma etching

    Directory of Open Access Journals (Sweden)

    Yunata Ersyzario Edo

    2015-01-01

    Full Text Available Diamond-Like Carbon (DLC and Chemical Vapor Deposition (CVD-diamond films have been widely utilized not only as a hard protective coating for molds and dies but also as a functional substrate for bio-MEMS/NEMS. Micro-texturing into these hard coated molds and dies provides a productive tool to duplicate the original mother micro-patterns onto various work materials and to construct any tailored micro-textures for sensors and actuators. In the present paper, the high density oxygen plasma etching method is utilized to make micro-line and micro-groove patterns onto the DLC and diamond coatings. Our developing oxygen plasma etching system is introduced together with characterization on the plasma state during etching. In this quantitative plasma diagnosis, both the population of activated species and the electron and ion densities are identified through the emissive light spectroscopy and the Langmuir probe method. In addition, the on-line monitoring of the plasmas helps to describe the etching process. DLC coated WC (Co specimen is first employed to describe the etching mechanism by the present method. Chemical Vapor Deposition (CVD diamond coated WC (Co is also employed to demonstrate the reliable capacity of the present high density oxygen plasma etching. This oxygen plasma etching performance is discussed by comparison of the etching rates.

  10. High flux film and transition boiling

    Energy Technology Data Exchange (ETDEWEB)

    Witte, L.C.

    1990-01-01

    This report is a bench-scale experiment on transition boiling. The author gives a detailed description on experimental apparatus and conditions. The visual observed boiling phenomena; nucleate boiling and film boiling, and the effect of heat transfer are also elucidated. 10 refs., 11 figs., 1 tab.

  11. The effect of textural complexity of solid foods on satiation.

    Science.gov (United States)

    Tang, Jingyuan; Larsen, Danaé S; Ferguson, Lynnette R; James, Bryony J

    2016-09-01

    Previous studies have shown that food texture affects satiation by influencing the eating rate, bite size and oral transit time. However, investigations into the direct effect of texture on satiation are limited. The objective of the current study was to investigate the effect of textural complexity on satiation, independent of oral processing time and energy density. A preload-test meal design was used in this study; model foods with three levels of textural complexity (low, medium and high) were consumed as preload foods followed by a two-course ad libitum meal. This study was a randomized cross-over trial with 38 subjects. The results clearly showed that food with greater textural complexity led to significantly lower food intake overall. The first course of the meal and total food intake was significantly reduced (psatiety after three hours post-trial and the time taken to the next eating occasion did not differ between different preload conditions. Increased textural complexity in food enhances satiation and may potentially impact on satiety however this needs to be further confirmed in future studies. The findings suggest that foods with more complex textures can be a helpful tool in reducing the short-term food intake and enhancing the satiation response.

  12. Cyber High School Students' Transition to a Traditional University

    Science.gov (United States)

    Gracey, Dorothy M.

    2010-01-01

    This mixed-method study identifies cyber high school graduates' perceptions of the effect of a cyber high school education on successful transition to a traditional university. The study examined students' perceptions of the advantages and disadvantages their cyber education experience contributed to their academic and social transition to…

  13. Improvement of texture and palatability of chicken breast: effect of high hydrostatic pressure and sodium hydrogen carbonate

    Science.gov (United States)

    Tabe, Kanae; Kim, Yun-Jung; Ohnuma, Shun; Ogoshi, Hiro; Suzuki, Atsushi; Nishiumi, Tadayuki

    2013-06-01

    Chicken breast is not preferred in Japan because it is not juicy. In this study, the effect of combined high pressure and sodium hydrogen carbonate (NaHCO3) treatment on the texture and palatability of chicken breast was investigated. The sample used was broiler chicken breast. Meat samples were soaked in.0-.4 M NaHCO3 solution and then pressurized at 100-400 MPa. After pressurization, the samples were heated for 30 min at 80°C and cooled down in ice-cold water. High pressure and NaHCO3 treatment of broiler chicken breast resulted in increased water content, and decreased weight reduction and rupture stress. Moreover, meat exposed to 200 MPa pressurization and.3 M NaHCO3 treatment was judged tender, juicy and of good taste by sensory evaluation. The combination of high pressure and NaHCO3 treatment can be effectively used for broiler chicken breast production.

  14. High-pressure homogenization of raw and pasteurized milk modifies the yield, composition, and texture of queso fresco cheese.

    Science.gov (United States)

    Escobar, D; Clark, S; Ganesan, V; Repiso, L; Waller, J; Harte, F

    2011-03-01

    High-pressure homogenization (HPH) of milk was studied as an alternative processing operation in the manufacturing of queso fresco cheese. Raw and pasteurized (65°C for 30 min) milks were subjected to HPH at 0, 100, 200, and 300 MPa and then used to manufacture queso fresco. The cheeses were evaluated for yield, moisture content, titratable acidity, nitrogen content, whey protein content, yield force, yield strain, and tactile texture by instrumental or trained panel analyses. The combination of HPH and thermal processing of milk resulted in cheeses with increased yield and moisture content. The net amount of protein transferred to the cheese per kilogram of milk remained constant for all treatments except raw milk processed at 300 MPa. The highest cheese yield, moisture content, and crumbliness were obtained for thermally processed milk subjected to HPH at 300 MPa. The principal component analysis of all measured variables showed that the variables yield, moisture content, and crumbliness were strongly correlated to each other and negatively correlated to the variables yield strain, protein content (wet basis), and sensory cohesiveness. It is suggested that the combination of thermal processing and HPH promotes thermally induced denaturation of whey protein, together with homogenization-induced dissociation of casein micelles. The combined effect results in queso fresco containing a thin casein-whey matrix that is able to better retain sweet whey. These results indicate that HPH has a strong potential for the manufacture of queso fresco with excellent yield and textural properties.

  15. Physical property and Textural transition across the Unconformity and Major Seismic Reflectors in the Upper plate of the Costa Rica Subduction zone offshore Osa Peninsula

    Science.gov (United States)

    Hamahashi, M.; Screaton, E.; Tanikawa, W.; Hashimoto, Y.; Martin, K. M.; Saito, S.; Kimura, G.

    2014-12-01

    At the Costa Rica subduction zone offshore Osa Peninsula, the Cocos plate and Cocos Ridge subduct under the Caribbean plate along the Middle America Trench, creating active seismicity. In this region, the Caribbean plate is characterized by a well-consolidated, high velocity framework material beneath the slope sediments, but the nature of the upper plate material is yet unknown. During Integrated Ocean Drilling Program (IODP) Expedition 334 and 344, the unconformity between the slope sediments (Unit 1) and upper plate material (Units 2 and 3) consisting of lithic sedimentary units was penetrated at mid-slope Site 1380. In the current study, to characterize the compaction behavior of the upper plate material, we investigate the physical properties, texture and composition of the sediments at Site 1380 by conducting microstructural observations, resistivity measurements, particle size analyses, X-ray fluorescence and X-ray diffraction analyses. The microstructures of sediments observed through the microscope tend to develop dense and cohesive textures in low porosity sediments, and particle size changes across several unconformities. In particular, the small particle-sized lithic fragments compose larger bodies and form cohesive structures. The cross correlation between measured particle size and shipboard porosity show negative correlation especially at Unit 2, indicating that larger sized particles form smaller or fewer pores. From the results of XRF and XRD analyses, we found that Al, K, Ti tend to concentrate in the higher porosity sediments of Unit 1, whereas Si, Ca, P, Mg, Na, and Mn concentrate in the lower porosity sediments of Unit 2 and 3. The higher concentration in Mg, Na, Mn, Si may be due to minerals such as chlorite, serpentine, amphibole, and sodium manganese. The crossplots between porosity and element concentration show negative correlations in Mg, Na, and Mn with porosity, suggesting that the minerals rich in these elements may relate with the

  16. Simulation of transition dynamics to high confinement in fusion plasmas

    CERN Document Server

    Nielsen, A H; Madsen, J; Naulin, V; Rasmussen, J Juul; Wan, B N

    2014-01-01

    The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in close agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST. Particularly, the slow transition with an intermediate dithering phase is well reproduced by the numerical solutions. Additionally, the model reproduces the experimentally determined L-H transition power threshold scaling that the ion power threshold increases with increasing particle density. The results hold promise for developing predictive models of the transition, essential for understanding and optimizing future fusion power reactors.

  17. Growth of highly textured SnS on mica using an SnSe buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C., E-mail: charles.surya@polyu.edu.hk

    2014-08-01

    We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer.

  18. Elastic phase transitions in metals at high pressures.

    Science.gov (United States)

    Krasilnikov, O M; Vekilov, Yu Kh; Mosyagin, I Yu; Isaev, E I; Bondarenko, N G

    2012-04-19

    The elastic phase transitions of cubic metals at high pressures are investigated within the framework of Landau theory. It is shown that at pressures comparable with the magnitude of the bulk modulus the phase transition is connected with the loss of stability relative to uniform deformation of the crystalline lattice. Discontinuity of the order parameter at the transition point and its equilibrium value are expressed through the second- to fourth-order elastic constants. The second-,third- and fourth-order elastic constants and phonon dispersion curves of vanadium under hydrostatic pressure are obtained by first-principles calculations. Structural transformation in vanadium under pressure is studied using the obtained results. It is shown that the experimentally observed at P ≈ 69 GPa phase transition in vanadium is the first-order phase transition close to a second-order phase transition.

  19. High hydrostatic pressure modification of whey protein concentrate for improved body and texture of lowfat ice cream.

    Science.gov (United States)

    Lim, S-Y; Swanson, B G; Ross, C F; Clark, S

    2008-04-01

    Previous research demonstrated that application of high hydrostatic pressure (HHP), particularly at 300 MPa for 15 min, can enhance foaming properties of whey protein concentrate (WPC). The purpose of this research was to determine the practical impact of HHP-treated WPC on the body and texture of lowfat ice cream. Washington State University (WSU)-WPC was produced by ultrafiltration of fresh separated whey received from the WSU creamery. Commercial whey protein concentrate 35 (WPC 35) powder was reconstituted to equivalent total solids as WSU-WPC (8.23%). Three batches of lowfat ice cream mix were produced to contain WSU-WPC without HHP, WSU-WPC with HHP (300 MPa for 15 min), and WPC 35 without HHP. All lowfat ice cream mixes contained 10% WSU-WPC or WPC 35. Overrun and foam stability of ice cream mixes were determined after whipping for 15 min. Ice creams were produced using standard ice cream ingredients and processing. The hardness of ice creams was determined with a TA-XT2 texture analyzer. Sensory evaluation by balanced reference duo-trio test was carried out using 52 volunteers. The ice cream mix containing HHP-treated WSU-WPC exhibited the greatest overrun and foam stability, confirming the effect of HHP on foaming properties of whey proteins in a complex system. Ice cream containing HHP-treated WSU-WPC exhibited significantly greater hardness than ice cream produced with untreated WSU-WPC or WPC 35. Panelists were able to distinguish between ice cream containing HHP-treated WSU-WPC and ice cream containing untreated WPC 35. Improvements of overrun and foam stability were observed when HHP-treated whey protein was used at a concentration as low as 10% (wt/wt) in ice cream mix. The impact of HHP on the functional properties of whey proteins was more pronounced than the impact on sensory properties.

  20. Chameleons: Reptilian Texture

    Science.gov (United States)

    Petersen, Hugh

    2009-01-01

    This article presents an art project inspired by a drawing of a chameleon the author saw in an art-supply catalog. Chameleons prove to be a good subject to highlight shape, color and texture with eigth-graders. In this project, middle- and high-school students draw a chameleon, learn how to use shapes to add to their chameleon drawing, learn how…

  1. Texture & Textiles, Together

    Science.gov (United States)

    Guhin, Paula

    2011-01-01

    Creating a painting with texture is easy, although using heavy gel medium or modeling paste may be pricey ways to go about it. High school artists generally like making collages and mixed-media. In this article, the author suggests ways to capitalize on that interest with inexpensive fabric in a painting project.

  2. Anti-adhesion effects of liquid-infused textured surfaces on high-temperature stainless steel for soft tissue

    Science.gov (United States)

    Zhang, Pengfei; Chen, Huawei; Zhang, Liwen; Zhang, Deyuan

    2016-11-01

    Soft tissue adhesion on the electrosurgical instruments can induce many serious complications, such as failure of hemostasis and damage to the surrounding soft tissue. The soft tissue adhesion is mainly caused by the high temperature on the instrument surface generally made of stainless steel. Nepenthes inspired liquid-infused surfaces (LIS), highly promising for anti-adhesion, have attracted considerable interests. In this paper, we investigated the anti-adhesion effects of LIS on high-temperature stainless steel for soft tissue for the first time, aiming to develop a new approach to solve the soft tissue adhesion problem. The textured surface, acting as the holding structures, was fabricated by photolithography-assisted chemical etching. Silicone oil, with good biocompatibility and high-temperature resistance, was chosen as the infused liquid. The adhesion force measurements for soft tissue on the LIS at high temperatures indicated that the soft tissue adhesion force was decreased by approximately 80% at 250 °C. Besides, the cycle tests of soft tissue adhesion force demonstrated the excellent stability of prepared LIS. We anticipate that LIS will be of great promise for practical applications on the electrosurgical instruments.

  3. Towards an Improved Algorithm for Estimating Freeze-Thaw Dates of a High Latitude Lake Using Texture Analysis of SAR Images

    Science.gov (United States)

    Uppuluri, A. V.; Jost, R. J.; Luecke, C.; White, M. A.

    2008-12-01

    Analyzing the freeze-thaw dates of high latitude lakes is an important part of climate change studies. Due to the various advantages provided by the use of SAR images, with respect to remote monitoring of small lakes, SAR image analysis is an obvious choice to estimate lake freeze-thaw dates. An important property of SAR images is its texture. The problem of estimating freeze-thaw dates can be restated as a problem of classifying an annual time series of SAR images based on the presence or absence of ice. We analyzed a few algorithms based on texture to improve the estimation of freeze-thaw dates for small lakes using SAR images. We computed the Gray Level Co-occurrence Matrix (GLCM) for each image and extracted ten different texture features from the GLCM. We used these texture features (namely, Energy, Contrast, Correlation, Homogeneity, Entropy, Autocorrelation, Dissimilarity, Cluster Shade, Cluster Prominence and Maximum Probability as previously used in studies related to the texture analysis of SAR sea ice imagery) as input to a group of classification algorithms to find the most accurate classifier and set of texture features that can help to decide the presence or absence of ice on the lake. The accuracy of the estimated freeze-thaw dates is dependent on the accuracy of the classifier. It is considered highly difficult to differentiate between open water (without wind) and the first day of ice formed on the lake (due to the similar mean backscatter values) causing inaccuracy in calculating the freeze date. Similar inaccuracy in calculating the thaw date arise due to the close backscatter values of water (with wind) and later stages of ice on the lake. Our method is promising but requires further research in improving the accuracy of the classifiers and selecting the input features.

  4. Facile fabrication of functional PDMS surfaces with tunable wettablity and high adhesive force via femtosecond laser textured templating

    Directory of Open Access Journals (Sweden)

    Yanlei Hu

    2014-12-01

    Full Text Available Femtosecond laser processing is emerged as a promising tool to functionalize surfaces of various materials, including metals, semiconductors, and polymers. However, the productivity of this technique is limited by the low efficiency of laser raster scanning. Here we report a facile approach for efficiently producing large-area functional polymer surfaces, by which metal is firstly textured by a femtosecond laser, and the as-prepared hierarchical structures are subsequently transferred onto polydimethylsiloxane (PDMS surfaces. Aluminum pieces covered by laser induced micro/nano-structures act as template masters and their performance of displaying diverse colors are investigated. Polymer replicas are endowed with tunable wetting properties, which are mainly attributed to the multi-scale surface structures. Furthermore, the surfaces are found to have extremely high adhesive force for water drops because of the high water penetration depth and the resultant high contact angle hysteresis. This characteristic facilitates many potential applications like loss-free tiny water droplets transportation. The reusability of metal master and easiness of soft lithography make it to be a very simple, fast and cost-efficient way for mass production of functional polymeric surfaces.

  5. Structural transition of FeSe under high pressure

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Chen Jun-Fang; He Qin-Yu; Wang Teng; Pan Zhong-Liang

    2011-01-01

    The density functional calculations of the energy band structure and density of state for the tetragonal PbO-type phase α-FeSe and hexagonal NiAs-type phase β-FeSe are reported in this paper. The structural phase transition from tetragonal to hexagonal FeSe under high pressure is investigated, it is found that the calculated transition pressure for the α→β phase transformation is 8.5 GPa. Some fluctuations in the transition pressure maybe occurred by different external factors such as temperature and stress condition. There is about 17% volume collapse accompanying the α→β phase transformation.

  6. Highly birefringent crystal for Raman transitions with phase modulators

    Science.gov (United States)

    Arias, Nieves; Abediyeh, Vahide; Hamzeloui, Saeed; Jeronimo-Moreno, Yasser; Gomez, Eduardo

    2016-05-01

    We present a system to excite Raman transitions with minimum phase noise. The system uses a phase modulator to generate the phase locked beams required for the transition. We use a long calcite crystal to filter out one of the sidebands, avoiding the cancellation that appears at high detunings for phase modulation. The measured phase noise is limited by the quality of the microwave synthesizer. We use the calcite crystal a second time to produce a co-propagating Raman pair with perpendicular polarizations to drive velocity insensitive Raman transitions. Support from CONACYT and Fundacion Marcos Moshinsky.

  7. Simulation of transition dynamics to high confinement in fusion plasmas

    DEFF Research Database (Denmark)

    Nielsen, Anders Henry; Xu, G. S.; Madsen, Jens;

    2015-01-01

    The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST. Particula......The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST....... Particularly, the slow transition with an intermediate dithering phase is well reproduced at proper parameters. The model recovers the power threshold for the L-H transition as well as the decrease in power threshold switching from single to double null configuration observed experimentally. The results...

  8. Texture characteristics analysis of ultra-high pressure instant porridge based on texture profile analysis%基于质构曲线解析法的超高压方便粥质地分析

    Institute of Scientific and Technical Information of China (English)

    刘春娟; 丁亚西; 李东升; 张守勤; 侯丽丽

    2011-01-01

    Texture characteristics of three kinds of porridge with a single material(shelled corn,kidney bean and brown rice respectively)were analysed by Texture Profile Analysis(TPA).The results showed that ultra-high pressure processing could significantly reduce the extent of the retrogradation of porridge,and the hardness and gumminess of different cereal in porridge were decreased by ultra-high pressure processing.This effect was not obvious in the early storage,but apparent in the later.After the longtime process of storage,the texture characteristics of the samples processed at the condition of 300MPa for 5 minutes were similar to those of just cooked porridge compared with other conditions.%对玉米、芸豆和糙米三种单一原料高压方便粥采用质构曲线解析法进行质地分析,分析结果显示高压处理能缓解粥存储过程中的回生程度,主要表现在降低粥的硬度及胶着度,这种作用在存储初期并不明显,但随货架期的延长,压力处理样与未压力处理样在这两个指标上有明显区别。经过长时间放置后,300MPa处理5min样的各项质地指标最为接近新鲜米粥。

  9. A New Class of High Z Nanocrystalline and Textured Oxide-Based Thermoelectric Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop high figure of merit (ZT) oxide-based thermoelectric materials. This will be accomplished by engineering a novel microstructure that will lead...

  10. High-efficiency si/polymer hybrid solar cells based on synergistic surface texturing of Si nanowires on pyramids.

    Science.gov (United States)

    He, Lining; Lai, Donny; Wang, Hao; Jiang, Changyun; Rusli

    2012-06-11

    An efficient Si/PEDOT:PSS hybrid solar cell using synergistic surface texturing of Si nanowires (SiNWs) on pyramids is demonstrated. A power conversion efficiency (PCE) of 9.9% is achieved from the cells using the SiNW/pyramid binary structure, which is much higher than similar cells based on planar Si, pyramid-textured Si, and SiNWs. The PCE is the highest reported to-date for hybrid cells based on Si nanostructures and PEDOT.

  11. Highly Sensitive and Practical Detection of Plant Viruses via Electrical Impedance of Droplets on Textured Silicon-Based Devices

    Science.gov (United States)

    Ambrico, Marianna; Ambrico, Paolo Francesco; Minafra, Angelantonio; De Stradis, Angelo; Vona, Danilo; Cicco, Stefania R.; Palumbo, Fabio; Favia, Pietro; Ligonzo, Teresa

    2016-01-01

    Early diagnosis of plant virus infections before the disease symptoms appearance may represent a significant benefit in limiting disease spread by a prompt application of appropriate containment steps. We propose a label-free procedure applied on a device structure where the electrical signal transduction is evaluated via impedance spectroscopy techniques. The device consists of a droplet suspension embedding two representative purified plant viruses i.e., Tomato mosaic virus and Turnip yellow mosaic virus, put in contact with a highly hydrophobic plasma textured silicon surface. Results show a high sensitivity of the system towards the virus particles with an interestingly low detection limit, from tens to hundreds of attomolar corresponding to pg/mL of sap, which refers, in the infection time-scale, to a concentration of virus particles in still-symptomless plants. Such a threshold limit, together with an envisaged engineering of an easily manageable device, compared to more sophisticated apparatuses, may contribute in simplifying the in-field plant virus diagnostics. PMID:27869726

  12. Drastic Control of Texture in a High Performance n-Type Polymeric Semiconductor and Implications for Charge Transport

    KAUST Repository

    Rivnay, Jonathan

    2011-07-12

    Control of crystallographic texture from mostly face-on to edge-on is observed for the film morphology of the n-type semicrystalline polymer {[N,N-9-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl] -alt-5,59-(2,29-bithiophene)}, P(NDI2OD-T2), when annealing the film to the polymer melting point followed by slow cooling to ambient temperature. A variety of X-ray diffraction analyses, including pole figure construction and Fourier transform peak shape deconvolution, are employed to quantify the texture change, relative degree of crystallinity and lattice order. We find that annealing the polymer film to the melt leads to a shift from 77.5% face-on to 94.6% edge-on lamellar texture as well as to a 2-fold increase in crystallinity and a 40% decrease in intracrystallite cumulative disorder. The texture change results in a significant drop in the electron-only diode current density through the film thickness upon melt annealing, while little change is observed in the in-plane transport of bottom gated thin film transistors. This suggests that the texture change is prevalent in the film interior and that either the (bottom) surface structure is different from the interior structure or the intracrystalline order and texture play a secondary role in transistor transport for this material. © 2011 American Chemical Society.

  13. Textural analysis of pre-therapeutic [18F]-FET-PET and its correlation with tumor grade and patient survival in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Thomas; Hiob, Daniela; Wester, Hans-Juergen [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [Klinikum Rechts der Isar der TU Muenchen, Neurosurgic Department, Munich (Germany); Schlegel, Juergen [Klinikum Rechts der Isar der TU Muenchen, Institute of Pathology and Neuropathology, Munich (Germany); Bette, Stefanie [Klinikum Rechts der Isar der TU Muenchen, Neuroradiologic department, Munich (Germany); Foerster, Stefan [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Klinikum Rechts der Isar der TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-01-15

    Amino acid positron emission tomography (PET) with [18F]-fluoroethyl-L-tyrosine (FET) is well established in the diagnostic work-up of malignant brain tumors. Analysis of FET-PET data using tumor-to-background ratios (TBR) has been shown to be highly valuable for the detection of viable hypermetabolic brain tumor tissue; however, it has not proven equally useful for tumor grading. Recently, textural features in 18-fluorodeoxyglucose-PET have been proposed as a method to quantify the heterogeneity of glucose metabolism in a variety of tumor entities. Herein we evaluate whether textural FET-PET features are of utility for grading and prognostication in patients with high-grade gliomas. One hundred thirteen patients (70 men, 43 women) with histologically proven high-grade gliomas were included in this retrospective study. All patients received static FET-PET scans prior to first-line therapy. TBR (max and mean), volumetric parameters and textural parameters based on gray-level neighborhood difference matrices were derived from static FET-PET images. Receiver operating characteristic (ROC) and discriminant function analyses were used to assess the value for tumor grading. Kaplan-Meier curves and univariate and multivariate Cox regression were employed for analysis of progression-free and overall survival. All FET-PET textural parameters showed the ability to differentiate between World Health Organization (WHO) grade III and IV tumors (p < 0.001; AUC 0.775). Further improvement in discriminatory power was possible through a combination of texture and metabolic tumor volume, classifying 85 % of tumors correctly (AUC 0.830). TBR and volumetric parameters alone were correlated with tumor grade, but showed lower AUC values (0.644 and 0.710, respectively). Furthermore, a correlation of FET-PET texture but not TBR was shown with patient PFS and OS, proving significant in multivariate analysis as well. Volumetric parameters were predictive for OS, but this correlation did not

  14. Seamless texture mapping algorithm for image-based three-dimensional reconstruction

    Science.gov (United States)

    Liu, Jiapeng; Liu, Bin; Fang, Tao; Huo, Hong; Zhao, Yuming

    2016-09-01

    Texture information plays an important role in rendering true objects, especially with the wide application of image-based three-dimensional (3-D) reconstruction and 3-D laser scanning. This paper proposes a seamless texture mapping algorithm to achieve a high-quality visual effect for 3-D reconstruction. At first, a series of image sets is produced by analyzing the visibility of triangular facets, the image sets are clustered and segmented into a number of optimal reference texture patches. Second, the generated texture patches are sequenced to create a rough texture map, then a weighting process is adopted to reduce the color discrepancies between adjacent patches. Finally, a multiresolution decomposition and fusion technique is used to generate the transition section and eliminate the boundary effect. Experiments show that the proposed algorithm is effective and practical for obtaining high-quality 3-D texture mapping for 3-D reconstruction. Compared with traditional methods, it maintains the texture clarity while eliminating the color seams, in addition, it also supports 3-D texture mapping for big data application.

  15. Investigation of work softening mechanisms and texture in a hot deformed 6061 aluminum alloy at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ezatpour, H.R., E-mail: H.R.Ezatpour@gmail.com [Department of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Haddad Sabzevar, M.; Sajjadi, S.A. [Department of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Huang, Yz., E-mail: yzhuang@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2014-06-01

    Hot deformation behavior of 6061 aluminum alloy was investigated by performing compression test in the temperature range of 350–500 °C. Equivalent strain rates were selected in the range of 0.0005–0.5 s{sup −1} in order to obtain processing and stability maps of the studied material using a Dynamic Material Model. Microstructure of the samples after deformation was analyzed by light and electron microscopy and the differences were compared together. The stresses obtained from the flow curves were related to strain rate (ε) and temperature (T) by a constitutive equation in hyperbolic sine function with hot deformation activation energy of 274 kJ/mol, and were described by the Zener–Hollomon equation. Microstructure results showed that with decreasing Z value, the elongated grains coarsened and the tendency of dynamic recrystallization enhanced. Correspondingly, the subgrain size increased and the dislocation density decreased. Moreover, the main softening mechanism of the alloy transformed from dynamic recovery to dynamic recrystallization. XRD results showed that the (200) texture has an important role in development of dynamic recystallization at high temperature.

  16. Effect of high pressure processing on textural and microbiological quality of pink perch (Nemipterus japonicus) sausage during chilled storage

    Science.gov (United States)

    Kunnath, Sarika; Panda, Satyen Kumar; Jaganath, Bindu; Gudipati, Venkateshwarlu

    2015-10-01

    The non-thermal high pressure (HP) processing was studied on fish sausage to enhance the quality during chilled storage. Pink perch (Nemipterus japonicus) sausages, packed in poly amide casing under vacuum were subjected to 400, 500 and 600 MPa pressures (dwell time: 10 min and ramp rate: 300 MPa/min) and compared with heat-set samples for physico-chemical and microbial quality parameters. Pressurized samples formed softer and glossier gels with a slight reduction in water-holding capacity. HP made the texture of sausage softer, cohesive and less chewy and gummier than heat-treated ones. Folding test seen higher acceptance values in samples treated at 500 and 600 MPa, during storage. Maximum log reduction in microbial count was observed in 600 MPa immediately, and significant difference in cooked and pressurized sausages was seen only up to 7th day. This revealed the potential application of HP in replacing conventional heat treatment for sausages preparation with enhanced shelf-life.

  17. Fluorinated epoxy resins with high glass transition temperatures

    Science.gov (United States)

    Griffith, James R.

    1991-01-01

    Easily processed liquid resins of low dielectric constants and high glass transition temperatures are useful for the manufacture of certain composite electronic boards. That combination of properties is difficult to acquire when dielectric constants are below 2.5, glass transition temperatures are above 200 C and processability is of conventional practicality. A recently issued patent (US 4,981,941 of 1 Jan. 1991) teaches practical materials and is the culmination of 23 years of research and effort and 15 patents owned by the Navy in the field of fluorinated resins of several classes. In addition to high fluorine content, practical utility was emphasized.

  18. Microstructures, textures and geothermometry of graphitic carbon in low- to high-grade mylonites

    Science.gov (United States)

    Cao, Shuyun; Neubauer, Franz; Lv, Meixia; Li, Junyu; Dong, Yanlong

    2017-04-01

    Graphitization differs from most mineral transformations occurring during diagenesis and metamorphism in that is an irreversible process. Graphitic carbon exhibits a large range of structures and chemical compositions, ranging from amorphous-like compounds (e.g. soot, low-grade coal), through a myriad of turbostratic structures (e.g. carbonaceous materials in metamorphic rocks), to rather rare crystalline flaky graphite. Graphitic material has a number of properties and the most significant one is the structural change of the graphitic materials with increase of temperature in the fault zones as well as in very low-grade to high-grade metamorphic terrains. During metamorphic processes, organic matter is progressively transformed into graphite and the degree of maturation or graphitization of graphitic materials is a potential tool, therefore, considered as a reliable indicator of peak conditions of the metamorphic grade in metamorphic petrology. In mylonites and brittle fault zones, graphitic material is rheologically very weak, a phenomenon, which results in shear concentration along zones rich in graphitic material. The characteristics and metamorphic peak conditions of graphitic material-bearing mylonites from fault zones are studied using optical microscopy, SEM, Electron Back-Scattered Diffraction (EBSD) and Raman microspectroscopy and carbon isotopic analysis. The graphite grains are distributed parallel to the mylonitic foliation and present coarse to very fine-grained microstructures. The deformation includes dislocation glide. The deformed graphite lattice-preferred orientation by EBSD measured records presents intracrystalline slip system, which is easy in the direction of the -axes and, in fact, nearly in any direction within the basal planes. The thermometry of graphitic material by Raman spectroscopy was calibrated for the temperature range from 360 to 650 °C. These structural analyses of graphitic material in mylonitic rocks allow unraveling the

  19. High-Cadence Transit Timing Variation Monitoring of Extrasolar Planets

    Directory of Open Access Journals (Sweden)

    Naef D.

    2011-02-01

    Full Text Available We report ground-based high-cadence transit timing observations of the extrasolar planet WASP-2b. We achieve a typical timing error of 15-30 sec. The data show no significant deviations from the predicted ephemeris.

  20. Transition of control in highly automated vehicles : a literature review.

    NARCIS (Netherlands)

    Vlakveld, W.P.

    2016-01-01

    The Directorate-General of Highways, Waterways, and Water Systems (Rijkswaterstaat in Dutch) of the Ministry of Infrastructure and the Environment (Ministerie van Infrastructuur en Milieu (IenM) in Dutch) has commissioned SWOV to conduct a literature review about transition of control in highly and

  1. High pressure structural phase transitions of PbPo

    Energy Technology Data Exchange (ETDEWEB)

    Bencherif, Y.; Boukra, A. [Departement de Physique, Faculte des Sciences, Universite de Mostaganem (Algeria); Departement de Physique, Universite des Sciences et de la Technologie d' Oran, USTO, Oran (Algeria); Zaoui, A., E-mail: azaoui@polytech-lille.fr [Universite Lille Nord de France, LGCgE (EA 4515) Lille1, Polytech' Lille, Cite Scientifique, Avenue Paul Langevin, 59655 Villeneuve D' Ascq Cedex (France); Ferhat, M. [Departement de Physique, Universite des Sciences et de la Technologie d' Oran, USTO, Oran (Algeria)

    2012-09-01

    First-principles calculations have been performed to investigate the high pressure phase transitions and dynamical properties of the less known lead polonium compound. The calculated ground state parameters for the NaCl phase show good agreement with the experimental data. The obtained results show that the intermediate phase transition for this compound is the orthorhombic Pnma phase. The PbPo undergoes from the rocksalt to Pnma phase at 4.20 GPa. Further structural phase transition from intermediate to CsCl phase has been found at 8.5 GPa. In addition, phonon dispersion spectra were derived from linear-response to density functional theory. In particular, we show that the dynamical properties of PbPo exhibit some peculiar features compared to other III-V compounds. Finally, thermodynamics properties have been also addressed from quasiharmonic approximation.

  2. Evolution of Microstructure and Texture during Annealing of Aluminum AA1050 Cold Rolled to High and Ultrahigh Strains

    DEFF Research Database (Denmark)

    Mishin, Oleg; Juul Jensen, Dorte; Hansen, Niels

    2010-01-01

    orientation: the mean size of grains having orientations of the rolling texture was smaller than the size of grains with other orientations. The orientation dependence of the recrystallized grain size was more pronounced in the samples rolled to ultrahigh strains. © 2010 The Minerals, Metals & Materials...

  3. Image-space texture-based output-coherent surface flow visualization.

    Science.gov (United States)

    Huang, Jin; Pan, Zherong; Chen, Guoning; Chen, Wei; Bao, Hujun

    2013-09-01

    Image-space line integral convolution (LIC) is a popular scheme for visualizing surface vector fields due to its simplicity and high efficiency. To avoid inconsistencies or color blur during the user interactions, existing approaches employ surface parameterization or 3D volume texture schemes. However, they often require expensive computation or memory cost, and cannot achieve consistent results in terms of both the granularity and color distribution on different scales. This paper introduces a novel image-space surface flow visualization approach that preserves the coherence during user interactions. To make the noise texture under different viewpoints coherent, we propose to precompute a sequence of mipmap noise textures in a coarse-to-fine manner for consistent transition, and map the textures onto each triangle with randomly assigned and constant texture coordinates. Further, a standard image-space LIC is performed to generate the flow texture. The proposed approach is simple and GPU-friendly, and can be easily combined with various texture-based flow visualization techniques. By leveraging viewpoint-dependent backward tracing and mipmap noise phase, our method can be incorporated with the image-based flow visualization (IBFV) technique for coherent visualization of unsteady flows. We demonstrate consistent and highly efficient flow visualization on a variety of data sets.

  4. Do Red Edge and Texture Attributes from High-Resolution Satellite Data Improve Wood Volume Estimation in a Semi-Arid Mountainous Region?

    DEFF Research Database (Denmark)

    Schumacher, Paul; Mislimshoeva, Bunafsha; Brenning, Alexander;

    2016-01-01

    Remote sensing-based woody biomass quantification in sparsely-vegetated areas is often limited when using only common broadband vegetation indices as input data for correlation with ground-based measured biomass information. Red edge indices and texture attributes are often suggested as a means...... to overcome this issue. However, clear recommendations on the suitability of specific proxies to provide accurate biomass information in semi-arid to arid environments are still lacking. This study contributes to the understanding of using multispectral high-resolution satellite data (RapidEye), specifically...... red edge and texture attributes, to estimate wood volume in semi-arid ecosystems characterized by scarce vegetation. LASSO (Least Absolute Shrinkage and Selection Operator) and random forest were used as predictive models relating in situ-measured aboveground standing wood volume to satellite data...

  5. Design of periodic nano- and macro-scale textures for high-performance thin-film multi-junction solar cells

    Science.gov (United States)

    Krc, J.; Sever, M.; Kovacic, M.; Moulin, E.; Campa, A.; Lipovsek, B.; Steltenpool, M.; van Erven, A. J. M.; Haug, F.-J.; Ballif, C.; Topic, M.

    2016-06-01

    Surface textures in thin-film silicon multi-junction solar cells play an important role in gaining the photocurrent of the devices. In this paper, a design of the textures is carried out for the case of amorphous silicon/micro-crystalline silicon (a-Si:H/μc-Si:H) solar cells, employing advanced modelling to determine the textures for defect-free silicon layer growth and to increase the photocurrent. A model of non-conformal layer growth and a hybrid optical modelling approach are used to perform realistic 3D simulations of the structures. The hybrid optical modelling includes rigorous modelling based on the finite element method and geometrical optics models. This enables us to examine the surface texture scaling from nano- to macro-sized (several tens or hundreds of micrometers) texturisation features. First, selected random and periodic nanotextures are examined with respect to critical positions of defect-region formation in Si layers. We show that despite careful selection of a well-suited semi-ellipsoidal periodic texture for defect-free layer growth, defective regions in Si layers of a-Si:H/μc-Si:H cell cannot be avoided if the lateral and vertical dimensions of the nano features are optimised only for high gain in photocurrent. Macro features are favourable for defect-free layer growth, but do not render the photocurrent gains as achieved with light-scattering properties of the optimised nanotextures. Simulation results show that from the optical point of view the semi-ellipsoidal periodic nanotextures with lateral features smaller than 0.4 μm and vertical peak-to-peak heights around or above 0.3 μm are required to achieve a gain in short-circuit current of the top cell with respect to the state-of-the-art random texture (>16% increase), whereas lateral dimensions around 0.8 μm and heights around 0.6 μm lead to a >6% gain in short-circuit current of the bottom cell.

  6. Effects of textural and surface characteristics of microporous activated carbons on the methane adsorption capacity at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bastos-Neto, M. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Canabrava, D.V. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Torres, A.E.B. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil); Rodriguez-Castellon, E. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Malaga, 29071 Malaga (Spain); Jimenez-Lopez, A. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Malaga, 29071 Malaga (Spain); Azevedo, D.C.S. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil)]. E-mail: diana@gpsa.ufc.br; Cavalcante, C.L. [Grupo de Pesquisas em Separacoes por Adsorcao (GPSA), Departamento de Engenharia Quimica, Universidade Federal do Ceara, Campus Universitario do Pici, Bl 709 60455-760 Fortaleza, CE (Brazil)

    2007-04-30

    The objective of this study is to relate textural and surface characteristics of selected microporous activated carbons to their methane storage capacity. In this work, a magnetic suspension balance (Rubotherm, Germany) was used to measure methane adsorption isotherms of several activated carbon samples. Textural characteristics were assessed by nitrogen adsorption on a regular surface area analyzer (Autosorb-MP, by Quantachrome, USA). N{sub 2} adsorption was analysed by conventional models (BET, DR, HK) and by Monte Carlo molecular simulations. Elemental and surface analyses were performed by X-ray photoelectronic spectroscopy (XPS) for the selected samples. A comparative analysis was then carried out with the purpose of defining some correlation among the variables under study. For the system under study, pore size distribution and micropore volume seem to be a determining factor as long as the solid surface is perfectly hydrophobic. It was concluded that the textural parameters per se do not unequivocally determine natural gas storage capacities. Surface chemistry and methane adsorption equilibria must be taken into account in the decision-making process of choosing an adsorbent for gas storage.

  7. High pressure behavior of 3d transition metal carbonates

    Science.gov (United States)

    Farfan, G. A.; Wang, S.; Boulard, E.; Mao, W. L.

    2012-12-01

    Understanding the behavior of carbon-rich phases in Earth's lower mantle is critical for modeling the global carbon cycle since the lower mantle may be the major repository for carbon in our planet. We were interested in the behavior of carbonates containing 3d transition metals, which can exhibit unusual properties at extreme conditions. Thus, we studied siderite (FeCO3) and rhodochrosite (MnCO3) at high pressure using a diamond anvil cell coupled with Raman spectroscopy, X-ray diffraction (XRD) and X-ray emission spectroscopy. In siderite we observed a high to low spin transition and associated volume collapse at approximately 46 GPa which is consistent with previous reports. Our Raman data show that the C-O bonds soften when the Fe2+ volume collapses (Farfan et al, 2012). In contrast, our XES results indicate that the Mn2+ in rhodochrosite does not undergo a spin transition like siderite up to 50 GPa. We observed a new Raman peak emerging above 48 GPa, which is a similar pressure at which a new structure was found in a previous XRD study.

  8. New Experimental Method for In Situ Determination of Material Textures at Simultaneous High-Pressure and -Temperature by Means of Radial Diffraction in the Diamond Anvil Cell.

    Energy Technology Data Exchange (ETDEWEB)

    Liermann, H; Merkel, S; Miyagi, L; Wenk, H; Shen, G; Cynn, H; Evans, W J

    2009-07-15

    We introduce the design and capabilities of a new resistive heated diamond anvil cell that can be used for side diffraction at simultaneous high-pressure and -temperature. The device can be used to study lattice-preferred orientations in polycrystalline samples up to temperatures of 1100 K and pressures of 36 GPa. Capabilities of the instrument are demonstrated with preliminary results on the development of textures in the BCC, FCC and HCP polymorphs of iron during a non-hydrostatic compression experiment at simultaneous high-pressure and -temperature.

  9. High Throughput Interrogation of Behavioral Transitions in C. elegans

    Science.gov (United States)

    Liu, Mochi; Shaevitz, Joshua; Leifer, Andrew

    We present a high-throughput method to probe transformations from neural activity to behavior in Caenorhabditis elegans to better understand how organisms change behavioral states. We optogenetically deliver white-noise stimuli to target sensory or inter neurons while simultaneously recording the movement of a population of worms. Using all the postural movement data collected, we computationally classify stereotyped behaviors in C. elegans by clustering based on the spectral properties of the instantaneous posture. (Berman et al., 2014) Transitions between these behavioral clusters indicate discrete behavioral changes. To study the neural correlates dictating these transitions, we perform model-driven experiments and employ Linear-Nonlinear-Poisson cascades that take the white-noise stimulus as the input. The parameters of these models are fitted by reverse-correlation from our measurements. The parameterized models of behavioral transitions predict the worm's response to novel stimuli and reveal the internal computations the animal makes before carrying out behavioral decisions. Preliminary results are shown that describe the neural-behavioral transformation between neural activity in mechanosensory neurons and reversal behavior.

  10. High frequency microphone measurements for transition detection on airfoils

    DEFF Research Database (Denmark)

    Døssing, Mads

    Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given...... pressure) and Tollmien-Schlichting frequencies. The tests were made at Reynolds and Mach numbers corresponding to the operating conditions of a typical horizontal axis wind turbine (HAWT). The Risø B1-18, Risø C2-18 and NACA0015 profiles were tested and the measured transition points are reported....

  11. Isostructural Transition of MgB2 Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Ling; WU Qi; ZHAN Zai-Ji; WANG Wen-Kui; WANG Wen-Kui; T.Kikegawa

    2001-01-01

    The high-pressure behaviour of the superconductor MgB2 with a hexagonal structure has been investigated by the in situ synchrotron radiation x-ray diffraction method under pressures up to 42.2 GPa in a diamond anvil cell. An abrupt decrease of about 7% in the unit cell volume of this material occurs in the pressure range of 26.3-30.2 GPa. A split of the Raman spectrum was also observed. The jump of the compression curve and Raman spectrum are ascribed to an isostructural transition in MgB2 at a pressure of 30.2 GPa.

  12. Inverting Aboveground Biomass–Canopy Texture Relationships in a Landscape of Forest Mosaic in the Western Ghats of India Using Very High Resolution Cartosat Imagery

    Directory of Open Access Journals (Sweden)

    Sourabh Pargal

    2017-03-01

    Full Text Available Large scale assessment of aboveground biomass (AGB in tropical forests is often limited by the saturation of remote sensing signals at high AGB values. Fourier Transform Textural Ordination (FOTO performs well in quantifying canopy texture from very high-resolution (VHR imagery, from which stand structure parameters can be retrieved with no saturation effect for AGB values up to 650 Mg·ha−1. The method is robust when tested on wet evergreen forests but is more demanding when applied across different forest types characterized by varying structures and allometries. The present study focuses on a gradient of forest types ranging from dry deciduous to wet evergreen forests in the Western Ghats (WG of India, where we applied FOTO to Cartosat-1a images with 2.5 m resolution. Based on 21 1-ha ground control forest plots, we calibrated independent texture–AGB models for the dry and wet zone forests in the area, as delineated from the distribution of NDVI values computed from LISS-4 multispectral images. This stratification largely improved the relationship between texture-derived and field-derived AGB estimates, which exhibited a R2 of 0.82 for a mean rRMSE of ca. 17%. By inverting the texture–AGB models, we finally mapped AGB predictions at 1.6-ha resolution over a heterogeneous landscape of ca. 1500 km2 in the WG, with a mean relative per-pixel propagated error <20% for wet zone forests, i.e., below the recommended IPCC criteria for Monitoring, Reporting and Verification (MRV methods. The method proved to perform well in predicting high-resolution AGB values over heterogeneous tropical landscape encompassing diversified forest types, and thus presents a promising option for affordable regional monitoring systems of greenhouse gas (GhG emissions related to forest degradation.

  13. Spherical harmonics in texture analysis

    Science.gov (United States)

    Schaeben, Helmut; van den Boogaart, K. Gerald

    2003-07-01

    The objective of this contribution is to emphasize the fundamental role of spherical harmonics in constructive approximation on the sphere in general and in texture analysis in particular. The specific purpose is to present some methods of texture analysis and pole-to-orientation probability density inversion in a unifying approach, i.e. to show that the classic harmonic method, the pole density component fit method initially introduced as a distinct alternative, and the spherical wavelet method for high-resolution texture analysis share a common mathematical basis provided by spherical harmonics. Since pole probability density functions and orientation probability density functions are probability density functions defined on the sphere Ω3⊂ R3 or hypersphere Ω4⊂ R4, respectively, they belong at least to the space of measurable and integrable functions L1( Ωd), d=3, 4, respectively. Therefore, first a basic and simplified method to derive real symmetrized spherical harmonics with the mathematical property of providing a representation of rotations or orientations, respectively, is presented. Then, standard orientation or pole probability density functions, respectively, are introduced by summation processes of harmonic series expansions of L1( Ωd) functions, thus avoiding resorting to intuition and heuristics. Eventually, it is shown how a rearrangement of the harmonics leads quite canonically to spherical wavelets, which provide a method for high-resolution texture analysis. This unified point of view clarifies how these methods, e.g. standard functions, apply to texture analysis of EBSD orientation measurements.

  14. Structural phase transitions in high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Tatarenko, H.M. [Toulon Univ., 83 - Le Garde (France). Lab. des Materiaux Multiphases et Interfaces; Nihoul, G.E. [Toulon Univ., 83 - Le Garde (France). Lab. des Materiaux Multiphases et Interfaces

    1995-11-01

    This chapter is devoted to the study of the order-disorder like phase transitions which occur in the high-temperature superconductors (HTS). We mainly consider Lanthanium based compounds like La{sub 2}CuO{sub 4+{delta}} or La{sub 2-x}M{sub x}CuO{sub 4+{delta}} (where M is an alkali atom Ba, Sr, Ca, Na, K, ..) and Yttrium based superconductors like YBa{sub 2}Cu{sub 3}O{sub 6+{delta}}. Different kinds of ordered structures were found in these compounds by X-ray and neutron diffraction, as well as by High Resolution Electron Microscopy imaging and are described. The theoretical models, which describe the structural evolution as temperature and/or concentration of the different components vary, are considered in detail. The relation between structural instabilities and high-temperature superconductivity is discussed. (orig.)

  15. Rheologic Transitions During Exhumation of High-Pressure Metamorphic Rocks

    Science.gov (United States)

    Whitney, D. L.; Teyssier, C. P.; Rey, P. F.

    2015-12-01

    The exhumation of deeply buried rocks typically involves dynamic feedbacks between deformation and metamorphic reactions (+ fluid and/or melt) that influence rheology and facilitate or drive large-magnitude exhumation. The evolution of grain-scale to terrane-scale processes during decompression can be seen in rocks exhumed from oceanic and continental subduction and from orogenic crust. In the Sivrihisar (Turkey) high-P/low-T (oceanic subduction) complex, microstructures record deformation and syn-kinematic reactions during decompression from eclogite to blueschist facies conditions; this transformation resulted in dramatic strength reduction that promoted strain localization along the subduction interface. In quartz-rich rocks, qz was deformed in the dislocation creep regime and records transitions in microstructure and slip systems during near-isothermal decompression from 2.5 to 1.5 GPa; these transitions may be related to decreasing water fugacity over tens of km of decompression. High-to ultrahigh-P eclogite in exhumed continental subduction zones such as the Western Gneiss Region (Norway) record decompression from >2.5 GPa to crust, upper crustal extension/transtension drives rapid ascent of the deep crust to form migmatite-cored domes. The exhuming deep crust entrains HP relics such as eclogite (e.g. Montagne Noire dome, France) as it traverses much of the orogenic crust, from >1.2 GPa to (in some cases) crust reaches the near-surface. In summary, decompression of subducted or deeply buried crust systematically leads to rheologic transitions and feedbacks between deformation and metamorphism in the presence of aqueous fluid and/or melt.

  16. High performance thin film transistor (flex-TFT) with textured nanostructure ZnO film channel fabricated by exploiting electric double layer gate insulator

    Science.gov (United States)

    Ghimire, Rishi Ram; Raychaudhuri, A. K.

    2017-01-01

    We report a flexible thin film transistor (flex-TFT) fabricated on a commonly available polyimide (Kapton®) tape with a channel of highly textured nanocrystalline ZnO film grown by pulsed laser deposition. The flex-TFT with an electric double layer (EDL) gate insulator shows a low threshold for operation (Vth ≤ 1 V), an ON/OFF ratio reaching ≈107 and a subthreshold swing ≈75 mV/dec. The superior performance is enabled by a high saturation mobility (μs ≈ 70 cm2/V s) of the highly textured nanocrystalline channel. The low Vth arises from large charge density (≈1014/cm2) induced into the channel by EDL gate insulator. The large charge density induced by the EDL gate dielectric also enhances the Hall mobility in the film and brings down the sheet resistance by nearly 2 orders, which leads to large ON/OFF ratio. The flex-TFT operation can be sustained with reproducibility when the TFT is bent down to a radius of curvature ≈2 cm.

  17. Texturing of high T(sub c) superconducting polycrystalline fibers/wires by laser-driven directional solidification in an thermal gradient

    Science.gov (United States)

    Varshney, Usha; Eichelberger, B. Davis, III

    1995-01-01

    This paper summarizes the technique of laser-driven directional solidification in a controlled thermal gradient of yttria stabilized zirconia core coated Y-Ba-Cu-O materials to produce textured high T(sub c) superconducting polycrystalline fibers/wires with improved critical current densities in the extended range of magnetic fields at temperatures greater than 77 K. The approach involves laser heating to minimize phase segregation by heating very rapidly through the two-phase incongruent melt region to the single phase melt region and directionally solidifying in a controlled thermal gradient to achieve highly textured grains in the fiber axis direction. The technique offers a higher grain growth rate and a lower thermal budget compared with a conventional thermal gradient and is amenable as a continuous process for improving the J(sub c) of high T(sub c) superconducting polycrystalline fibers/wires. The technique has the advantage of suppressing weak-link behavior by orientation of crystals, formation of dense structures with enhanced connectivity, formation of fewer and cleaner grain boundaries, and minimization of phase segregation in the incongruent melt region.

  18. Automated Transition State Theory Calculations for High-Throughput Kinetics.

    Science.gov (United States)

    Bhoorasingh, Pierre L; Slakman, Belinda L; Seyedzadeh Khanshan, Fariba; Cain, Jason Y; West, Richard Henry

    2017-08-18

    A scarcity of known chemical kinetic parameters leads to the use of many reaction rate estimates, which are not always sufficiently accurate, in the construction of detailed kinetic models. To reduce the reliance on these estimates and improve the accuracy of predictive kinetic models, we have developed a high-throughput, fully automated, reaction rate calculation method, AutoTST. The algorithm integrates automated saddle-point geometry search methods and a canonical transition state theory kinetics calculator. The automatically calculated reaction rates compare favorably to existing estimated rates. Comparison against high level theoretical calculations show the new automated method performs better than rate estimates when the estimate is made by a poor analogy. The method will improve by accounting for internal rotor contributions and by improving methods to determine molecular symmetry.

  19. Comparison between the magnetic and transport critical current densities in high critical current density melt-textured yttrium barium copper-oxide

    Science.gov (United States)

    Gao, L.; Meng, R. L.; Xue, Y. Y.; Hor, P. H.; Chu, C. W.

    1991-01-01

    Using a recently developed pulsed critical current density (Jc) measuring system, the Jc of the high-Jc melt-textured YBa2Cu3O(7-delta) (Y123) bulk samples has been determined. I-V curves with a voltage resolution of 0.5 microV were obtained, and transport Jc's along the a-b plane as high as 7.2 x 10 to the 4th A/sq cm were extracted. These results are comparable to the values obtained magnetically. On the other hand, transport Jc along the c axis were found to be two orders of magnitude smaller, even though the magnetic Jc along the c axis is only about five times smaller than Jc along the a-b plane. It is suggested that for the high-temperature superconducting materials which are highly anisotropic, caution should be taken when using the nontransport magnetic methods to determine Jc.

  20. Large Energy Storage Density and High Thermal Stability in a Highly Textured (111)-Oriented Pb0.8Ba0.2ZrO3 Relaxor Thin Film with the Coexistence of Antiferroelectric and Ferroelectric Phases.

    Science.gov (United States)

    Peng, Biaolin; Zhang, Qi; Li, Xing; Sun, Tieyu; Fan, Huiqing; Ke, Shanming; Ye, Mao; Wang, Yu; Lu, Wei; Niu, Hanben; Zeng, Xierong; Huang, Haitao

    2015-06-24

    A highly textured (111)-oriented Pb0.8Ba0.2ZrO3 (PBZ) relaxor thin film with the coexistence of antiferroelectric (AFE) and ferroelectric (FE) phases was prepared on a Pt/TiOx/SiO2/Si(100) substrate by using a sol-gel method. A large recoverable energy storage density of 40.18 J/cm(3) along with an efficiency of 64.1% was achieved at room temperature. Over a wide temperature range of 250 K (from room temperature to 523 K), the variation of the energy density is within 5%, indicating a high thermal stability. The high energy storage performance was endowed by a large dielectric breakdown strength, great relaxor dispersion, highly textured orientation, and the coexistence of FE and AFE phases. The PBZ thin film is believed to be an attractive material for applications in energy storage systems over a wide temperature range.

  1. High Energy Transitions in the Decay of 132I

    DEFF Research Database (Denmark)

    Johnson, N.; Wilsky, K.; Gregers Hansen, P.

    1965-01-01

    A study of the high-energy gamma rays of 132I with a three-crystal pair spectrometer has disclosed the presence of several new transitions. In addition, it has permitted more precise energy assignments for the previously observed gamma rays. Gamma rays having energies greater than the pair......-ray spectrometer covering the energy range of 100–2200 keV. Electron lines were observed corresponding to transitions at 147.4±0.9, 263.0±0.9, 285.5±1.1, 523.0±1.2, 631.5±1.4, 669.0±1.2 (complex), 728.8±1.7, 773.8±1.6, 954.9±1.9 and 1395±8 keV. A careful study of the end-point region of the beta spectrum has shown...... thet the maximum energy beta ray of 132I is at 2118±15 keV....

  2. R(2OBBIE-3D, a Fast Robotic High-Resolution System for Quantitative Phenotyping of Surface Geometry and Colour-Texture.

    Directory of Open Access Journals (Sweden)

    António F Martins

    Full Text Available While recent imaging techniques provide insights into biological processes from the molecular to the cellular scale, phenotypes at larger scales remain poorly amenable to quantitative analyses. For example, investigations of the biophysical mechanisms generating skin morphological complexity and diversity would greatly benefit from 3D geometry and colour-texture reconstructions. Here, we report on R(2OBBIE-3D, an integrated system that combines a robotic arm, a high-resolution digital colour camera, an illumination basket of high-intensity light-emitting diodes and state-of-the-art 3D-reconstruction approaches. We demonstrate that R(2OBBIE generates accurate 3D models of biological objects between 1 and 100 cm, makes multiview photometric stereo scanning possible in practical processing times, and enables the capture of colour-texture and geometric resolutions better than 15 μm without the use of magnifying lenses. R(2OBBIE has the potential to greatly improve quantitative analyses of phenotypes in addition to providing multiple new applications in, e.g., biomedical science.

  3. AC susceptibilities of grain-textured superconductors

    Science.gov (United States)

    Sakamoto, N.; Fukuda, Y.; Koga, M.; Akune, T.; Khan, H. R.; Lüders, K.

    2008-09-01

    In-phase χ n‧ and out-phase χ n″ components of nth harmonics of AC susceptibility with measuring parameters of a DC magnetic field Bdc, an amplitude Ba and a frequency f of the superimposed AC magnetic fields give substantial information of the superconducting properties. In low- Tc metallic superconductors, χ1‧ shows smooth transition and χ1″ does single peak. High- Tc oxide superconductors with anisotropic and grain-textured structures show deformed complex characteristics. Double peaks in χ1″ and shoulders in χ1‧ appear in AC susceptibility of Hg-1223 superconductors. Instead of simple Bean model, a grained model, where the superconducting grains are immersed in weak superconducting matrix, are proposed. The susceptibilities numerically analyzed using the model show varied and deformed curves and are successfully compared with the measured results.

  4. The Science of Soil Textures

    Science.gov (United States)

    Bigham, Gary

    2010-01-01

    Off-road motorcycle racing and ATV riding. Gardening and fishing. What do these high-adrenaline and slower-paced pastimes have in common? Each requires soil, and the texture of that soil has an effect on all of them. In the inquiry-based lessons described here, students work both in the field or laboratory and in the classroom to collect soil…

  5. Accelerated Parallel Texture Optimization

    Institute of Scientific and Technical Information of China (English)

    Hao-Da Huang; Xin Tong; Wen-Cheng Wang

    2007-01-01

    Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis (PCA) are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000+ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.

  6. 3D textural evidence for the formation of ultra-high tenor precious metal bearing sulphide microdroplets in offset reefs: An extreme example from the Platinova Reef, Skaergaard Intrusion, Greenland

    Science.gov (United States)

    Holwell, David A.; Barnes, Stephen J.; Le Vaillant, Margaux; Keays, Reid R.; Fisher, Louise A.; Prasser, Richard

    2016-07-01

    The Platinova Reef in the Skaergaard Intrusion, east Greenland, is an example of a type of layered-intrusion-hosted, precious metal-enriched, stratiform, disseminated sulphide deposit referred to as "offset reefs". These typically show platinum-group element (PGE) enrichment immediately below a major increase in the abundance of Cu-rich sulphides, with a prominent peak in Au enrichment exactly at that transition between the PGE-rich and the Cu-sulphide-rich zones. The reasons for the relative sequence of offsets in metal peaks, and the occasionally very high metal tenors have been subject to great debate. Here we use an integrated approach of high-resolution X-ray computed tomography (HRXCT), SEM, synchrotron and desktop microbeam XRF mapping, and thin section petrography to comprehensively classify the textural relations of the precious metal-bearing sulphides of the Platinova Reef as an extreme end member example of an exceedingly high tenor offset deposit. Our results show that in the zones of PGE enrichment, precious metal minerals (PMMs) are intimately associated with Cu sulphide globules, mostly located at, or close to, silicate and oxide boundaries. The textures are identical in zones enriched in Pd and Au, and thus we do not see any evidence for different processes forming the different zones. The PMM:Cu sulphide ratio in each globule varies significantly but overall the size of the globules increases from the Pd-rich, through the Au-rich, and into the Cu zone, with a significant corresponding decrease in PM tenor. As such, this records a progression of exceedingly high tenor, microdroplets of sulphide, which progressively get larger up through the section, and decrease in tenor proportionally to their size. Cumulus droplets of Cu sulphide became enriched in metals, and were trapped in situ without significant transport from their point of nucleation. The transition to larger sulphides represents a change from sulphides nucleated and trapped in situ, to

  7. Textures in Dilaton Gravity

    CERN Document Server

    Dando, O

    1999-01-01

    We examine the field equations of a self-gravitating texture in low-energy superstring gravity, allowing for an arbitrary coupling of the texture field to the dilaton. Both massive and massless dilatons are considered. For the massless dilaton, we find that non-singular spacetimes only exist for certain values of the coupling, dependent on the gravitational strength of the texture. For the massive dilaton, the texture induces a long-range dilaton cloud, but we expect the gravitational behaviour of the defect to be similar to that found in Einstein theory. We compare these results with those found for other global topological defects.

  8. Texture Evolution During Laser Direct Metal Deposition of Ti-6Al-4V

    Science.gov (United States)

    Sridharan, Niyanth; Chaudhary, Anil; Nandwana, Peeyush; Babu, Sudarsanam Suresh

    2016-03-01

    Titanium alloys are used in a wide variety of high-performance applications and hence the processing of titanium and the resulting microstructures after additive manufacturing has received significant attention. During additive manufacturing, the processing route involves the transition from a liquid to solid state. The addition of successive layers results in a complex microstructure due to solid-state transformations. The current study focuses on understanding the phase transformations and relate them to the transformation texture in Ti-6Al-4V to identify conditions leading to a strong alpha transformation texture. The as-deposited builds were characterized using optical microscopy and electron backscattered diffraction. The results showed columnar prior β grains with a martensitic structure after the deposition of a single layer. On subsequent depositions, the martensitic microstructure decomposed to a colony and basketweave microstructure with a stronger transformation texture. The alpha texture with a colony and basketweave microstructure showed a stronger transformation texture as a result of variant selection. Thus, by controlling the cooling rate of the build from the β transus, it is possible to control the alpha transformation texture.

  9. High Power Picosecond Laser Surface Micro-texturing of H13 Tool Steel and Pattern Replication onto ABS Plastics via Injection Moulding

    Science.gov (United States)

    Otanocha, Omonigho B.; Li, Lin; Zhong, Shan; Liu, Zhu

    2016-03-01

    H13 tool steels are often used as dies and moulds for injection moulding of plastic components. Certain injection moulded components require micro-patterns on their surfaces in order to modify the physical properties of the components or for better mould release to reduce mould contamination. With these applications it is necessary to study micro-patterning to moulds and to ensure effective pattern transfer and replication onto the plastic component during moulding. In this paper, we report an investigation into high average powered (100 W) picosecond laser interactions with H13 tool steel during surface micro-patterning (texturing) and the subsequent pattern replication on ABS plastic material through injection moulding. Design of experiments and statistical modelling were used to understand the influences of laser pulse repetition rate, laser fluence, scanning velocity, and number of scans on the depth of cut, kerf width and heat affected zones (HAZ) size. The characteristics of the surface patterns are analysed. The process parameter interactions and significance of process parameters on the processing quality and efficiency are characterised. An optimum operating window is recommended. The transferred geometry is compared with the patterns generated on the dies. A discussion is made to explain the characteristics of laser texturing and pattern replication on plastics.

  10. High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation.

    Science.gov (United States)

    Nomoto, Junichi; Makino, Hisao; Yamamoto, Tetsuya

    2016-12-01

    Five hundred-nanometer-thick ZnO-based textured polycrystalline films consisting of 490-nm-thick Al-doped ZnO (AZO) films deposited on 10-nm-thick Ga-doped ZnO (GZO) films exhibited a high Hall mobility (μ H) of 50.1 cm(2)/Vs with a carrier concentration (N) of 2.55 × 10(20) cm(-3). Firstly, the GZO films were prepared on glass substrates by ion plating with dc arc discharge, and the AZO films were then deposited on the GZO films by direct current magnetron sputtering (DC-MS). The GZO interface layers with a preferential c-axis orientation play a critical role in producing AZO films with texture development of a well-defined (0001) orientation, whereas 500-nm-thick AZO films deposited by only DC-MS showed a mixture of the c-plane and the other plane orientation, to exhibit a μ H of 38.7 cm(2)/Vs with an N of 2.22 × 10(20) cm(-3).

  11. High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation

    Science.gov (United States)

    Nomoto, Junichi; Makino, Hisao; Yamamoto, Tetsuya

    2016-06-01

    Five hundred-nanometer-thick ZnO-based textured polycrystalline films consisting of 490-nm-thick Al-doped ZnO (AZO) films deposited on 10-nm-thick Ga-doped ZnO (GZO) films exhibited a high Hall mobility ( μ H) of 50.1 cm2/Vs with a carrier concentration ( N) of 2.55 × 1020 cm-3. Firstly, the GZO films were prepared on glass substrates by ion plating with dc arc discharge, and the AZO films were then deposited on the GZO films by direct current magnetron sputtering (DC-MS). The GZO interface layers with a preferential c-axis orientation play a critical role in producing AZO films with texture development of a well-defined (0001) orientation, whereas 500-nm-thick AZO films deposited by only DC-MS showed a mixture of the c-plane and the other plane orientation, to exhibit a μ H of 38.7 cm2/Vs with an N of 2.22 × 1020 cm-3.

  12. Using numerical analysis to develop and evaluate the method of high temperature sous-vide to soften carrot texture in different-sized packages.

    Science.gov (United States)

    Hong, Yoon-Ki; Uhm, Joo-Tae; Yoon, Won Byong

    2014-04-01

    The high-temperature sous-vide (HTSV) method was developed to prepare carrots with a soft texture at the appropriate degree of pasteurization. The effect of heating conditions, such as temperature and time, was investigated on various package sizes. Heating temperatures of 70, 80, and 90 °C and heating times of 10 and 20 min were used to evaluate the HTSV method. A 3-dimensional conduction model and numerical simulations were used to estimate the temperature distribution and the rate of heat transfer to samples with various geometries. Four different-sized packages were prepared by stacking carrot sticks of identical size (9.6 × 9.6 × 90 mm) in a row. The sizes of the packages used were as follows: (1) 9.6 × 86.4 × 90, (2) 19.2 × 163.2 × 90, (3) 28.8 × 86.4 × 90, and (4) 38.4 × 86.4 × 90 mm. Although only a moderate change in color (L*, a*, and b*) was observed following HTSV cooking, there was a significant decrease in carrot hardness. The geometry of the package and the heating conditions significantly influenced the degree of pasteurization and the final texture of the carrots. Numerical simulations successfully described the effect of geometry on samples at different heating conditions. © 2014 Institute of Food Technologists®

  13. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    K T Kashyap

    2001-02-01

    The development of recrystallization textures has been debated for the past 50 years. Essentially the rival theories of evolution of recrystallization textures i.e. oriented nucleation (ON) and oriented growth (OG) has been under dispute. In the ON model, it has been argued that a higher frequency of the special orientation (grains) than random occur, thus accounting for the texture. In the OG model, it has been argued that the specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random orientations thus contributing to the final recrystallization texture. In FCC metals and alloys like aluminium, cube orientation [(001) $\\langle$100$\\rangle$] is the recrystallization texture component. In the classic OG model, cube orientation is supposed to be misoriented from -orientation [(123) $\\langle$63$\\bar{4}\\rangle$] which is a deformation texture component by a 40° about $\\langle$111$\\rangle$ relationship which is supposed to be a high mobility boundary leading to faster growth of cube grains. Stereographic calculations and analytical calculations are presented in this paper to the effect that the -orientation (123) $\\langle$63$\\bar{4}\\rangle$ is not misoriented from cube (100) $\\langle$001$\\rangle$ by 40° (111) whereas another deformation texture component (123) $\\langle$41$\\bar{2}\\rangle$ which is termed the -component is misoriented from cube component by 40°$\\ \\langle$111$\\rangle$ . -component is also seen in deformation textures of aluminium and hence the classic OG model remains valid with respect to the -component.

  14. Theoretical and experimental study of highly textured GaAs on silicon using a graphene buffer layer

    Science.gov (United States)

    Alaskar, Yazeed; Arafin, Shamsul; Lin, Qiyin; Wickramaratne, Darshana; McKay, Jeff; Norman, Andrew G.; Zhang, Zhi; Yao, Luchi; Ding, Feng; Zou, Jin; Goorsky, Mark S.; Lake, Roger K.; Zurbuchen, Mark A.; Wang, Kang L.

    2015-09-01

    A novel heteroepitaxial growth technique, quasi-van der Waals epitaxy, promises the ability to deposit three-dimensional GaAs materials on silicon using two-dimensional graphene as a buffer layer by overcoming the lattice and thermal expansion mismatch. In this study, density functional theory (DFT) simulations were performed to understand the interactions at the GaAs/graphene hetero-interface as well as the growth orientations of GaAs on graphene. To develop a better understanding of the molecular beam epitaxy-grown GaAs films on graphene, samples were characterized by x-ray diffraction (θ-2θ scan, ω-scan, grazing incidence XRD and pole figure measurement) and transmission electron microscopy. The realizations of smooth GaAs films with a strong (111) oriented fiber-texture on graphene/silicon using this deposition technique are a milestone towards an eventual demonstration of the epitaxial growth of GaAs on silicon, which is necessary for integrated photonics application.

  15. Surface Evolution of Nano-Textured 4H–SiC Homoepitaxial Layers after High Temperature Treatments: Morphology Characterization and Graphene Growth

    Directory of Open Access Journals (Sweden)

    Xingfang Liu

    2015-09-01

    Full Text Available Nano-textured 4H–SiC homoepitaxial layers (NSiCLs were grown on 4H–SiC(0001 substrates using a low pressure chemical vapor deposition technique (LPCVD, and subsequently were subjected to high temperature treatments (HTTs for investigation of their surface morphology evolution and graphene growth. It was found that continuously distributed nano-scale patterns formed on NSiCLs which were about submicrons in-plane and about 100 nanometers out-of-plane in size. After HTTs under vacuum, pattern sizes reduced, and the sizes of the remains were inversely proportional to the treatment time. Referring to Raman spectra, the establishment of multi-layer graphene (MLG on NSiCL surfaces was observed. MLG with sp2 disorders was obtained from NSiCLs after a high temperature treatment under vacuum at 1700 K for two hours, while MLG without sp2 disorders was obtained under Ar atmosphere at 1900 K.

  16. High pressure phase transitions for CdSe

    Indian Academy of Sciences (India)

    Bo Kong; Ti-Xian Zeng; Zhu-Wen Zhou; De-Liang Chen; Xiao-Wei Sun

    2014-05-01

    The structure and pressure-induced phase transitions for CdSe are investigated using first-principles calculations. The pressure-induced phase transition sequence WZ/ZB $\\to$ Rs $\\to$ $\\to$ CsCl for CdSe is drawn reasonably for the fist time, the corresponding transition pressures are 3.8, 29 and 107 GPa, respectively and the intermediate states between the structure and the CsCl structure should exist.

  17. High-pressure phase transition of alkali metal-transition metal deuteride Li2PdD2

    Science.gov (United States)

    Yao, Yansun; Stavrou, Elissaios; Goncharov, Alexander F.; Majumdar, Arnab; Wang, Hui; Prakapenka, Vitali B.; Epshteyn, Albert; Purdy, Andrew P.

    2017-06-01

    A combined theoretical and experimental study of lithium palladium deuteride (Li2PdD2) subjected to pressures up to 50 GPa reveals one structural phase transition near 10 GPa, detected by synchrotron powder x-ray diffraction, and metadynamics simulations. The ambient-pressure tetragonal phase of Li2PdD2 transforms into a monoclinic C2/m phase that is distinct from all known structures of alkali metal-transition metal hydrides/deuterides. The structure of the high-pressure phase was characterized using ab initio computational techniques and from refinement of the powder x-ray diffraction data. In the high-pressure phase, the PdD2 complexes lose molecular integrity and are fused to extended [PdD2]∞ chains. The discovered phase transition and new structure are relevant to the possible hydrogen storage application of Li2PdD2 and alkali metal-transition metal hydrides in general.

  18. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Science.gov (United States)

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin

    2016-05-01

    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  19. Electronic transitions in highly charged ion-atom collisions

    Science.gov (United States)

    Schmidt-Böcking, H.; Ullrich, J.; Schuch, R.; Olson, R. E.; Dörner, R.

    1989-09-01

    Three different aspects of electronic transitions in fast, highly charged ion-atom collisions are discussed. First, experimental data and n-CTMC calculations for differential multiple ionization cross sections of 1.4 {MeV}/{u} U 32+on rare gas atoms are presented. It is shown that the electronic motion has a dramatic influence on the kinematics of the emitted particles (in particular the nuclei). The possibility is discussed to measure in fast ionizing processes by a recoil ion-projectile coincidence technique the internal sum momentum of "electron clusters" in atoms. This new "technique" opens a new field of atomic structure research at high-energy heavy-ion accelerators. Second, the use of the H-like heavy ions as projectiles is discussed to measure, through observable interference structures, static and dynamic properties of transiently formed superheavy quasimolecular systems. Third, the "ancient" gas target-solid target difference in the impact-parameter dependence of K-shell ionization in nearly symmetric ion-atom collisions is presented. This severe discrepancy between gas and solid still remains an unsolved fundamental problem in the field of inner-shell ionization in the MO regime.

  20. Characterizing the transition from high recycling to partial detachment

    Science.gov (United States)

    McLean, A. G.; Allen, S. L.; Fenstermacher, M.; Lasnier, C.; Meyer, W. H.; Porter, G.; Soukhanovskii, V.; Bray, B. D.; Carlstrom, T. N.; Leonard, A. W.; Liu, C.; Eldon, D.; Groth, M.; Stangeby, P. C.; Tsui, C.

    2014-10-01

    Experiments at DIII-D have explored the transition from the high recycling to the partially detached divertor condition in L- and H-mode with an unprecedented level of detail. Improved divertor and core Thomson scattering diagnostics were coupled with high resolution spectroscopic studies of molecular and neutral emissions. 2-D Te and ne profiles of the outer leg reveal the earliest indications of formation of the detachment front at the target plate, reducing local Te at the outer strike point from 8-10 eV to 2-3 eV with a marginal ( upstream. These data help guide and expose any missing physics in simulations of detachment onset using state-of-the-art boundary codes, and in predictions for operation with a partial detached divertor in future devices. This work supported in part by the US Department of Energy under DE-AC52-07NA27344 and DE-FC02-04ER54698.

  1. Measurement of Color Texture

    NARCIS (Netherlands)

    Hoang, M.A.; Geusebroek, J.M.; Chantler, M.

    2002-01-01

    In computer vision, measurement of image properties such as color or texture is essential. In this paper, we propose a solid framework for the local measurement of texture in color images. We give a physical basis for the integration of the well-known Gabor filters with the measurement of color. Our

  2. Measurement of Color Texture

    NARCIS (Netherlands)

    Hoang, M.A.; Geusebroek, J.M.; Deprettere, E.F.; Belloum, A.; Heijnsdijk, J.W.J.; van der Stappen, F.

    2002-01-01

    In computer vision, measurement of image properties such as color or texture is essential. However, existing methods for measuring color and texture in combination are not well-defined neither from a measurement theoretical basis nor from a physical point of view. We propose a solid framework for th

  3. Layered Textures for Image-Based Rendering

    Institute of Scientific and Technical Information of China (English)

    en-Cheng Wang; ui-Yu Li; in Zheng; n-Hua Wu

    2004-01-01

    An extension to texture mapping is given in this paper for improving the efficiency of image-based rendering. For a depth image with an orthogonal displacement at each pixel, it is decomposed by the displacement into a series of layered textures (LTs) with each one having the same displacement for all its texels. Meanwhile,some texels of the layered textures are interpolated for obtaining a continuous 3D approximation of the model represented in the depth image. Thus, the plane-to-plane texture mapping can be used to map these layered textures to produce novel views and the advantages can be obtained as follows: accelerating the rendering speed,supporting the 3D surface details and view motion parallax, and avoiding the expensive task of hole-filling in the rendering stage. Experimental results show the new method can produce high-quality images and run faster than many famous image-based rendering techniques.

  4. Automatic Texture Reconstruction of 3d City Model from Oblique Images

    Science.gov (United States)

    Kang, Junhua; Deng, Fei; Li, Xinwei; Wan, Fang

    2016-06-01

    In recent years, the photorealistic 3D city models are increasingly important in various geospatial applications related to virtual city tourism, 3D GIS, urban planning, real-estate management. Besides the acquisition of high-precision 3D geometric data, texture reconstruction is also a crucial step for generating high-quality and visually realistic 3D models. However, most of the texture reconstruction approaches are probably leading to texture fragmentation and memory inefficiency. In this paper, we introduce an automatic framework of texture reconstruction to generate textures from oblique images for photorealistic visualization. Our approach include three major steps as follows: mesh parameterization, texture atlas generation and texture blending. Firstly, mesh parameterization procedure referring to mesh segmentation and mesh unfolding is performed to reduce geometric distortion in the process of mapping 2D texture to 3D model. Secondly, in the texture atlas generation step, the texture of each segmented region in texture domain is reconstructed from all visible images with exterior orientation and interior orientation parameters. Thirdly, to avoid color discontinuities at boundaries between texture regions, the final texture map is generated by blending texture maps from several corresponding images. We evaluated our texture reconstruction framework on a dataset of a city. The resulting mesh model can get textured by created texture without resampling. Experiment results show that our method can effectively mitigate the occurrence of texture fragmentation. It is demonstrated that the proposed framework is effective and useful for automatic texture reconstruction of 3D city model.

  5. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.

    2012-01-01

    : The observations are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period...

  6. High haze textured surface B-doped ZnO-TCO films on wet-chemically etched glass substrates for thin film solar cells

    Science.gov (United States)

    Xinliang, Chen; Jieming, Liu; Jia, Fang; Ze, Chen; Ying, Zhao; Xiaodan, Zhang

    2016-08-01

    Textured glass substrates with crater-like feature sizes of ˜5-30 μm were obtained using the chemical etching method through adjusting the treatment round (R). Pyramid-like boron-doped zinc oxide (ZnO:B) films with feature sizes of ˜300-800 nm were deposited on the etched glass substrates by the metal organic chemical deposition (MOCVD) technique using water, diethylzinc and 1%-hydrogen-diluted diborane. The ZnO:B films on the etched glass with micro/nano double textures presented a much stronger light-scattering capability than the conventional ZnO:B on the flat glass and their electrical properties changed little. Typical etched glass-3R/ZnO:B exhibited a high root mean square (RMS) roughness of ˜160 nm. The haze values at the wavelengths of 550 nm and 850 nm for etched glass-3R/ZnO:B sample were 61% and 42%, respectively. Finally, the optimized etched glass/ZnO:B was applied in the silicon (Si) based thin film solar cells. The high haze etched glass/ZnO:B substrates have potential merits for thin film solar cells. Project supported by the State Key Development Program for Basic Research of China (Nos. 2011CBA00706, 2011CBA00707), the Tianjin Applied Basic Research Project and Cutting-Edge Technology Research Plan (No. 13JCZDJC26900), the Tianjin Major Science and Technology Support Project (No. 11TXSYGX22100), the National High Technology Research and Development Program of China (No. 2013AA050302), and the Fundamental Research Funds for the Central Universities (No. 65010341).

  7. High-resolution (SIMS) versus bulk sulfur isotope patterns of pyrite in Proterozoic microbialites with diverse mat textures

    Science.gov (United States)

    Gomes, M. L.; Fike, D. A.; Bergmann, K.; Knoll, A. H.

    2015-12-01

    Sulfur (S) isotope signatures of sedimentary pyrite preserved in marine rocks provide a rich suite of information about changes in biogeochemical cycling associated with the evolution of microbial metabolisms and oxygenation of Earth surface environments. Conventionally, these S isotope records are based on bulk rock measurements. Yet, in modern microbial mat environments, S isotope compositions of sulfide can vary by up to 40‰ over a spatial range of ~ 1 mm. Similar ranges of S isotope variability have been found in Archean pyrite grains using both Secondary Ion Mass Spectrometry and other micro-analytical techniques. These micron-scale patterns have been linked to changes in rates of microbial sulfate reduction and/or sulfide oxidation, isotopic distillation of the sulfate reservoir due to microbial sulfate reduction, and post-depositional alteration. Fine-scale mapping of S isotope compositions of pyrite can thus be used to differentiate primary environmental signals from post-depositional overprinting - improving our understanding of both. Here, we examine micron-scale S isotope patterns of pyrite in microbialites from the Mesoproterozoic-Neoproterozoic Sukhaya Tunguska Formation and Neoproterozoic Draken Formation in order to explore S isotope variability associated with different mat textures and pyrite grain morphologies. A primary goal is to link modern observations of how sulfide spatial isotope distributions reflect active microbial communities present at given depths in the mats to ancient processes driving fine-sale pyrite variability in microbialites. We find large (up to 60‰) S isotope variability within a spatial range of less than 2.5cm. The micron-scale S isotope measurements converge around the S isotope composition of pyrite extracted from bulk samples of the same microbialites. These micron-scale pyrite S isotope patterns have the potential to reveal important information about ancient biogeochemical cycling in Proterozoic mat environments

  8. Fast cartoon + texture image filters.

    Science.gov (United States)

    Buades, Antoni; Le, Triet M; Morel, Jean-Michel; Vese, Luminita A

    2010-08-01

    Can images be decomposed into the sum of a geometric part and a textural part? In a theoretical breakthrough, [Y. Meyer, Oscillating Patterns in Image Processing and Nonlinear Evolution Equations. Providence, RI: American Mathematical Society, 2001] proposed variational models that force the geometric part into the space of functions with bounded variation, and the textural part into a space of oscillatory distributions. Meyer's models are simple minimization problems extending the famous total variation model. However, their numerical solution has proved challenging. It is the object of a literature rich in variants and numerical attempts. This paper starts with the linear model, which reduces to a low-pass/high-pass filter pair. A simple conversion of the linear filter pair into a nonlinear filter pair involving the total variation is introduced. This new-proposed nonlinear filter pair retains both the essential features of Meyer's models and the simplicity and rapidity of the linear model. It depends upon only one transparent parameter: the texture scale, measured in pixel mesh. Comparative experiments show a better and faster separation of cartoon from texture. One application is illustrated: edge detection.

  9. Texture and nano-scale internal microstructure of otoliths in the Atlantic molly, Poecilia mexicana: a high-resolution EBSD study.

    Science.gov (United States)

    Schulz-Mirbach, T; Götz, A; Griesshaber, E; Plath, M; Schmahl, W W

    2013-08-01

    Otoliths of modern bony fishes are massive polycrystalline structures consisting mainly of calcium carbonate (primarily aragonite), and 1-10% organic residuals. Unlike other biomineralisates like shells, teeth and bones, they are not optimized for mechanical loads but serve the senses of hearing and balance in the inner ear. We examined internal structural variation of otoliths through microstructural and texture analyses. Our study applied the electron backscattered diffraction technique (EBSD) to whole sections of saccular otoliths on cave- and surface-dwelling fish. Application of high spatial resolution EBSD on otoliths of the livebearing fish Poecilia mexicana allowed for an investigation of crystal orientation despite the small size (<150 nm) of aragonite crystallites. Crystallites at the rims of otoliths had a higher structural organization than those situated near the center, where no dominant orientation pattern was discernible. Moreover, the medial (sulcal) face of otoliths, which makes contact with the sensory epithelium, was more structured than the lateral (antisulcal) face.

  10. Raman imaging of grain growth mechanism in highly textured Pb(Mg{1{/}3}Nb{2{/}3})O{3}-PbTiO{3} piezoelectric ceramics*

    Science.gov (United States)

    Colomban, P.; Pham Thi, Mai

    2005-06-01

    Pb(Mg{1 / 3}Nb{2 / 3})O{3}-PbTiO{3} solid solution ((1-x)PMN-xPT) tape cast ceramics have been prepared by homo-epitaxial templated grain growth (HTGG) using cubic 0.75PMN 0.25 PT single crystal seeds as template (a few wt%) and x = 0.35 nanoparticles for the ceramic matrix. Raman imaging studied representative medium and highly textured ceramics. On the base of a previous study which has shown that the Raman peak centre of gravity depends on the solid solution composition whereas peak intensity is correlated to the unit-cell distortion, Raman imaging shows that the final composition and structure is very close to that of the matrix.

  11. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    Directory of Open Access Journals (Sweden)

    ZHANG Chunsen

    2015-07-01

    Full Text Available This paper proposes a city texture fast reconstruction method based on aerial tilt image for reconstruction of three-dimensional city model. Based on the photogrammetry and computer vision theory and using the city building digital surface model obtained by prior treatment, through collinear equation calculation geometric projection of object and image space, to obtain the three-dimensional information and texture information of the structure and through certain the optimal algorithm selecting the optimal texture on the surface of the object, realize automatic extraction of the building side texture and occlusion handling of the dense building texture. The real image texture reconstruction results show that: the method to the 3D city model texture reconstruction has the characteristics of high degree of automation, vivid effect and low cost and provides a means of effective implementation for rapid and widespread real texture rapid reconstruction of city 3D model.

  12. Phase Transition and Structure of Silver Azide at High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    D Hou; F Zhang; C Ji; T Hannon; H Zhu; J Wu; V Levitas; Y Ma

    2011-12-31

    Silver azide (AgN{sub 3}) was compressed up to 51.3 GPa. The results reveal a reversible second-order orthorhombic-to-tetragonal phase transformation starting from ambient pressure and completing at 2.7 GPa. The phase transition is accompanied by a proximity of cell parameters a and b, a 3{sup o} rotation of azide anions, and a change of coordination number from 4-4 (four short, four long) to eight fold. The crystal structure of the high pressure phase is determined to be in I4/mcm space group, with Ag at 4a, N{sub 1} at 4d, and N{sub 2} at 8h Wyckoff positions. Both of the two phases have anisotropic compressibility: the orthorhombic phase exhibits an anomalous expansion under compression along a-axis and is more compressive along b-axis than c-axis; the tetragonal phase is more compressive along the interlayer direction than the intralayer directions. The bulk moduli of the orthorhombic and tetragonal phases are determined to be K{sub OT} = 39{+-}5 GPa with K{sub OT'} = 10{+-}7 and K{sub OT} = 57 {+-}2 GPa with K{sub OT'} = 6.6{+-}0.2, respectively.

  13. Texture and anisotropy of ferroelectric bismuth titanate

    Science.gov (United States)

    Jones, Jacob Leo

    Ferroelectric bismuth titanate, Na0.5Bi4.5 Ti4O15, is a piezoelectric ceramic used as an electromechanical sensor in high temperature environments (T piezoelectric constant, d33, is relatively low in randomly oriented ceramics. Crystallographic texturing is often employed to increase the piezoelectric constant because the spontaneous polarization axes of the grains are better aligned. This research distinguishes between the crystallographic texture induced to the grains from tape casting and crystallographic texture induced to the ferroelectric domains from electrical poling. Novel quantitative approaches describe texture of both types independently using conventional and synchrotron X-ray sources as well as time-of-flight neutron diffraction with multiple detectors. Furthermore, methods are developed to describe the combined effect of a ferroelectric texture superimposed on a paraelectric texture. Texture of the paraelectric crystallographic axes was induced by novel processing approaches. An alternative to using plate-shaped template particles was developed utilizing calcined powder. Paraelectric texture develops from particle settling and strong surface energy anisotropy during sintering. The 00l textures induced from this process are on the order of two to four multiples of a random distribution. These textures create property anisotropies between the casting plane and normal directions of 6.4 and 5.7 in piezoelectric d33 constant and remanent polarization, respectively. Texture of the ferroelectric crystallographic axes was induced by electrical poling at different temperatures and in different orientations. Ceramics with an initial paraelectric texture can exhibit greater change in the domain volume fractions during electrical poling than randomly oriented ceramics. This is demonstrated by applying novel quantitative approaches to reflection X-ray spectra from many sample directions. Because orthorhombic Na0.5Bi 4.5Ti4O15 has two ferroelectric domains that

  14. High pressure and microwave based synthesis of transition metal pnictides

    Energy Technology Data Exchange (ETDEWEB)

    Pobel, Roman Rupert

    2016-04-11

    The goal of this thesis was to explore the possibilities of synthetic methods that are not very common in current transition metal pnictide research. The substitution of the Ca-site in CaFe{sub 2}As{sub 2} with rare earth elements such as Pr the has been reported to induce superconductivity. However, some inconsistencies in the data suggested a non-intrinsic origin of the observed diamagnetic signal. Furthermore a solubility limit of 13% was found when prepared in an electrical furnace thus leaving a huge part of the physical phase diagram inaccessible. A high pressure/high temperature synthesis was developed to allow access to the whole doping range and an in-depth characterization of this compound was carried out. During the experiments concerning the high pressure synthesis of Ca{sub 1-x}Pr{sub x}Fe{sub 2}As{sub 2} the new ternary iron arsenide CaFe{sub 5}As{sub 3} was identified and classified as a member of the Ca{sub n(n+1)/2}(Fe{sub 1-x}M{sub x}){sub (2+3n)}M'{sub n(n-1)/2}As{sub (n+1)(n+2)/2} (n = 1-3; M =Nb, Pd, Pt; M' = □, Pd, Pt) family. The complete solid solution Ca{sub 1-x}Pr{sub x}Fe{sub 5}As{sub 3} (O ≤ x ≤ 1) was prepared and physically characterized. Furthermore, several useful techniques were developed to aid in future high pressure based investigations of transition metal pnictides. The second part of this thesis concerns a completely different, but equally promising synthetic approach. Microwave based synthesis is a well-established technique in many solution based fields, such as organic, medicinal or nano chemistry. For solid state and materials research several parameters and particularities have to be considered. But when successful, it allows for the reduction of reaction time by several orders of magnitude. It has very rarely been applied in the preparation of pnictides and on1y once in the context of pnictide superconductor research. The possibilities of this method were explored and employed in the preparation of several

  15. High transition-temperature SQUID magnetometers and practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Dantsker, Eugene [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa2Cu3O7-x (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO3-YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz-1/2 at 1 Hz and 8.5 fT Hz-1/2 at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz-1/2 at 1 Hz and 18 fT Hz-1/2 at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room.

  16. High transition-temperature SQUID magnetometers and practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Dantsker, E [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO{sub 3}-YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz{sup {minus}1/2} at 1 Hz and 8.5 fT Hz{sup {minus}1/2} at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz{sup {minus}1/2} at 1 Hz and 18 fT Hz{sup {minus}1/2} at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room.

  17. High-Fidelity Aerodynamic Design with Transition Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To enhance aerodynamic design capabilities, Desktop Aeronautics proposes to combine a new sweep/taper integrated-boundary-layer (IBL) code that includes transition...

  18. Impact of storage on dark chocolate: texture and polymorphic changes.

    Science.gov (United States)

    Nightingale, Lia M; Lee, Soo-Yeun; Engeseth, Nicki J

    2011-01-01

    Chocolate storage is critical to final product quality. Inadequate storage, especially with temperature fluctuations, may lead to rearrangement of triglycerides that make up the bulk of the chocolate matrix; this rearrangement may lead to fat bloom. Bloom is the main cause of quality loss in the chocolate industry. The effect of storage conditions leading to bloom formation on texture and flavor attributes by human and instrumental measures has yet to be reported. Therefore, the impact of storage conditions on the quality of dark chocolate by sensory and instrumental measurements was determined. Dark chocolate was kept under various conditions and analyzed at 0, 4, and 8 wk of storage. Ten members of a descriptive panel analyzed texture and flavor. Instrumental methods included texture analysis, color measurement, lipid polymorphism by X-ray diffraction and differential scanning calorimetry, triglyceride concentration by gas chromatography, and surface properties by atomic force microscopy. Results were treated by analysis of variance, cluster analysis, principal component analysis, and linear partial least squares regression analysis. Chocolate stored 8 wk at high temperature without fluctuations and 4 wk with fluctuations transitioned from form V to VI. Chocolates stored at high temperature with and without fluctuations were harder, more fracturable, more toothpacking, had longer melt time, were less sweet, and had less cream flavor. These samples had rougher surfaces, fewer but larger grains, and a heterogeneous surface. Overall, all stored dark chocolate experienced instrumental or perceptual changes attributed to storage condition. Chocolates stored at high temperature with and without fluctuations were most visually and texturally compromised. Practical Application: Many large chocolate companies do their own "in-house" unpublished research and smaller confectionery facilities do not have the means to conduct their own research. Therefore, this study relating

  19. Textured Image Segmentation

    Science.gov (United States)

    1980-01-01

    security applications of scene analysis are reconnaissance, night vision, mapping and terrain classification, target detection and tracking, traffic ... stereopsis and relative motion. 5 *’"." * * m - _- , . _ . . . b -.- -, . ..,. .. . .. . ... . ..... . .... .. . Texture perception is itself a

  20. Texture of Frozen Food

    Science.gov (United States)

    Wani, Kohmei

    Quantitative determination of textural quality of frozen food due to freezing and storage conditions is complicated,since the texture is consisted of multi-dimensiona1 factors. The author reviewed the importance of texture in food quality and the factors which is proposed by a priori estimation. New classification of expression words of textural properties by subjective evaluation and an application of four elements mechanical model for analysis of physical characteristics was studied on frozen meat patties. Combination of freezing-thawing condition on the subjective properties and physiochemical characteristics of beef lean meat and hamachi fish (Yellow-tail) meat was studied. Change of the plasticity and the deformability of these samples differed by freezing-thawing rate and cooking procedure. Also optimum freezing-thawing condition was differed from specimens.

  1. In Situ Observation of Gypsum-Anhydrite Transition at High Pressure and High Temperature

    Institute of Scientific and Technical Information of China (English)

    LIU Chuan-Jiang; ZHENG Hai-Fei

    2012-01-01

    An in-situ Raman spectroscopic study of gypsum-anhydrite transition under a saturated water condition at high pressure and high temperature is performed using a hydrothermal diamond anvil cell (HDAC).The experimental results show that gypsum dissolvs in water at ambient temperature and above 496 MPa.With increasing temperature,the anhydrite (CaSO4) phase precipitates at 250 320℃ in the pressure range of 1.0 1.5 GPa,indicating that under a saturated water condition,both stable conditions of pressure and temperature and high levels of Ca and SO4 ion concentrations in aqueous solution are essential for the formation of anhydrite.A linear relationship between the pressure and temperature for the precipitation of anhydrite is established as P(GPa) =0.0068T - 0.7126 (250℃≤T≤320℃).Anhydrite remained stable during rapid cooling of the sample chamber,showing that the gypsum-anhydrite transition involving both dissolution and precipitation processes is irreversible at high pressure and high temperature.%An in-situ Raman spectroscopic study of gypsum-anhydrite transition under a saturated water condition at high pressure and high temperature is performed using a hydrothermal diamond anvil cell (HDAC). The experimental results show that gypsum dissolvs in water at ambient temperature and above 496 Mpa. With increasing temperature, the anhydrite (CaSO4) phase precipitates at 250-320℃ in the pressure range of 1.0-1.5 Gpa, indicating that under a saturated water condition, both stable conditions of pressure and temperature and high levels of Ca and SO4 ion concentrations in aqueous solution are essential for the formation of anhydrite. A linear relationship between the pressure and temperature for the precipitation of anhydrite is established as P(Gpa) = 0.0068T - 0.7126 (250℃≤T≤320℃). Anhydrite remained stable during rapid cooling of the sample chamber, showing that the gypsum-anhydrite transition involving both dissolution and precipitation processes is

  2. Textures of liquid crystals

    CERN Document Server

    Dierking, Ingo

    2006-01-01

    A unique compendium of knowledge on all aspects of the texture of liquid crystals, providing not just detailed information on texture formation and determination, but also an in-depth discussion of different characterization methods. Experts as well as graduates entering the field will find all the information they need in this handbook, while the magnitude of the color images make it valuable hands-on-reference.

  3. Simulating the directional, spectral and textural properties of a large-scale scene at high resolution using a MODIS BRDF product

    Science.gov (United States)

    Rengarajan, Rajagopalan; Goodenough, Adam A.; Schott, John R.

    2016-10-01

    Many remote sensing applications rely on simulated scenes to perform complex interaction and sensitivity studies that are not possible with real-world scenes. These applications include the development and validation of new and existing algorithms, understanding of the sensor's performance prior to launch, and trade studies to determine ideal sensor configurations. The accuracy of these applications is dependent on the realism of the modeled scenes and sensors. The Digital Image and Remote Sensing Image Generation (DIRSIG) tool has been used extensively to model the complex spectral and spatial texture variation expected in large city-scale scenes and natural biomes. In the past, material properties that were used to represent targets in the simulated scenes were often assumed to be Lambertian in the absence of hand-measured directional data. However, this assumption presents a limitation for new algorithms that need to recognize the anisotropic behavior of targets. We have developed a new method to model and simulate large-scale high-resolution terrestrial scenes by combining bi-directional reflectance distribution function (BRDF) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data, high spatial resolution data, and hyperspectral data. The high spatial resolution data is used to separate materials and add textural variations to the scene, and the directional hemispherical reflectance from the hyperspectral data is used to adjust the magnitude of the MODIS BRDF. In this method, the shape of the BRDF is preserved since it changes very slowly, but its magnitude is varied based on the high resolution texture and hyperspectral data. In addition to the MODIS derived BRDF, target/class specific BRDF values or functions can also be applied to features of specific interest. The purpose of this paper is to discuss the techniques and the methodology used to model a forest region at a high resolution. The simulated scenes using this method for varying

  4. Vertically aligned biaxially textured molybdenum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Rahul [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Riley, Michael [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina [US Army Armament Research, Development and Engineering Center, Benet Labs, Watervliet, New York 12189 (United States); Lu, Toh-Ming [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2011-09-15

    Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

  5. High precision wavelength measurements of QED-sensitive forbidden transitions in highly charged argon ions.

    Science.gov (United States)

    Draganić, I; Crespo López-Urrutia, J R; DuBois, R; Fritzsche, S; Shabaev, V M; Orts, R Soria; Tupitsyn, I I; Zou, Y; Ullrich, J

    2003-10-31

    We present the results of an experimental study of magnetic dipole (M1) transitions in highly charged argon ions (Ar X, Ar XI, Ar XIV, Ar XV) in the visible spectral range using an electron beam ion trap. Their wavelengths were determined with, for highly charged ions, unprecedented accuracy up to the sub-ppm level and compared with theoretical calculations. The QED contributions, calculated in this Letter, are found to be 4 orders of magnitude larger than the experimental error and are absolutely indispensable to bring theory and experiment to a good agreement. This method shows great potential for the study of QED effects in relativistic few-electron systems.

  6. Peculiarities of high-overtone transition probabilities in carbon monoxide revealed by high-precision calculation

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, Emile S., E-mail: esmedved@orc.ru [The Institute of Problems of Chemical Physics, Russian Academy of Sciences, Prospect Akademika Semenova 1, 142432 Chernogolovka (Russian Federation); Meshkov, Vladimir V.; Stolyarov, Andrey V. [Department of Chemistry, Lomonosov Moscow State University, Leninskie gory 1/3, 119991 Moscow (Russian Federation); Gordon, Iouli E. [Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, Massachusetts 02138 (United States)

    2015-10-21

    In the recent work devoted to the calculation of the rovibrational line list of the CO molecule [G. Li et al., Astrophys. J., Suppl. Ser. 216, 15 (2015)], rigorous validation of the calculated parameters including intensities was carried out. In particular, the Normal Intensity Distribution Law (NIDL) [E. S. Medvedev, J. Chem. Phys. 137, 174307 (2012)] was employed for the validation purposes, and it was found that, in the original CO line list calculated for large changes of the vibrational quantum number up to Δn = 41, intensities with Δn > 11 were unphysical. Therefore, very high overtone transitions were removed from the published list in Li et al. Here, we show how this type of validation is carried out and prove that the quadruple precision is indispensably required to predict the reliable intensities using the conventional 32-bit computers. Based on these calculations, the NIDL is shown to hold up for the 0 → n transitions till the dissociation limit around n = 83, covering 45 orders of magnitude in the intensity. The low-intensity 0 → n transition predicted in the work of Medvedev [Determination of a new molecular constant for diatomic systems. Normal intensity distribution law for overtone spectra of diatomic and polyatomic molecules and anomalies in overtone absorption spectra of diatomic molecules, Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 1984] at n = 5 is confirmed, and two additional “abnormal” intensities are found at n = 14 and 23. Criteria for the appearance of such “anomalies” are formulated. The results could be useful to revise the high-overtone molecular transition probabilities provided in spectroscopic databases.

  7. Relighting multiple color textures

    Institute of Scientific and Technical Information of China (English)

    DIAO Chang-yu; LU Dong-ming; LIU Gang

    2005-01-01

    With the development of digital library technology, library books made of paper can be digital released and read, and Endangered Cultural Heritages can be preserved. Traditional library's contents and functions can be greatly enhanced by digital technologies. For these new library objects, the primary key problem is precisely reconstructing their 3D models. When constructing complete 3D models, multiple color texture maps are often necessary. A commonly encountered problem uncounted during fusing of textures from multiple color images is color distortion. Each texture of a single 3D model may be obtained under possibly different lighting conditions and color response of the camera. To remove any visible seam and improve color consistency between the textures while avoiding color distortion, we propose a new efficient algorithm to relight all the texture images globally,spread residual light difference, and recolor each image by homogeneous transformation. A relative illumination model was adopted to obtain the relighting function. We choose lαβ color space with minimal correlation between channels for many natural scenes, for calculating the relighting result. Looking into two overlapped images A and B, we can pairwise relight B into A's luminosity condition in two steps. We first scale B's l channel by the lA/lB ratio of the overlapped region. We can assume A and B are in a same color plane now. Then a homogeneous transformation is applied to B's α and β channels which moves B into A's hue and saturation condition. For multiple overlapped color textures, a patch based weighted global relighting method was proposed to minimize the total color difference. The pairwise relighting method was used between each two overlapped images, and the difference in every overlapped region after relighting was weighted and summed up to construct an energy value. We used Nelder-Mead method to find a minimal energy value and the relighting parameters for every image. After

  8. Continuums of Precarity: Refugee Youth Transitions in American High Schools

    Science.gov (United States)

    McWilliams, Julia Ann; Bonet, Sally Wesley

    2016-01-01

    This article examines how the pre-migratory experiences of 90 Bhutanese, Burmese, and Iraqi refugee youth shape their aspirations, needs and capabilities as they transition to postsecondary education and work in the American urban context. It further explores how their schooling experiences in precarious urban school districts influence their…

  9. Aesthetics by numbers:Links between perceived texture qualities and computed visual texture properties

    Directory of Open Access Journals (Sweden)

    Richard Henrikus Augustinus Hubertus Jacobs

    2016-07-01

    Full Text Available Our world is filled with texture. For the human visual system, this is an important source of information for assessing environmental and material properties. Indeed – and presumably for this reason– the human visual system has regions dedicated to processing textures. Despite their abundance and apparent relevance, only recently the relationships between texture features and high-level judgments have captured the interest of mainstream science, despite long-standing indications for such relationships. In this study, we explore such relationships, as these might be used to predict perceived texture qualities. This is relevant, not only from a psychological/neuroscience perspective, but also for more applied fields such as design, architecture, and the visual arts. In two separate experiments, observers judged various qualities of visual textures such as beauty, roughness, naturalness, elegance, and complexity. Based on factor analysis, we find that in both experiments, ~75% of the variability in the judgments could be explained by a two-dimensional space, with axes that are closely aligned to the beauty and roughness judgments. That a two-dimensional judgment space suffices to capture most of the variability in the perceived texture qualities suggests that observers use a relatively limited set of internal scales on which to base various judgments, including aesthetic ones.Finally, for both of these judgments, we determined the relationship with a large number of texture features computed for each of the texture stimuli. We find that the presence of lower spatial frequencies, oblique orientations, higher intensity variation, higher saturation, and redness correlates with higher beauty ratings. Features that captured image intensity and uniformity correlated with roughness ratings. Therefore, a number of computational texture features are predictive of these judgments. This suggests that perceived texture qualities – including the aesthetic

  10. Watermarking textures in video games

    Science.gov (United States)

    Liu, Huajian; Berchtold, Waldemar; Schäfer, Marcel; Lieb, Patrick; Steinebach, Martin

    2014-02-01

    Digital watermarking is a promising solution to video game piracy. In this paper, based on the analysis of special challenges and requirements in terms of watermarking textures in video games, a novel watermarking scheme for DDS textures in video games is proposed. To meet the performance requirements in video game applications, the proposed algorithm embeds the watermark message directly in the compressed stream in DDS files and can be straightforwardly applied in watermark container technique for real-time embedding. Furthermore, the embedding approach achieves high watermark payload to handle collusion secure fingerprinting codes with extreme length. Hence, the scheme is resistant to collusion attacks, which is indispensable in video game applications. The proposed scheme is evaluated in aspects of transparency, robustness, security and performance. Especially, in addition to classical objective evaluation, the visual quality and playing experience of watermarked games is assessed subjectively in game playing.

  11. Texture of lipid bilayer domains

    DEFF Research Database (Denmark)

    Jensen, Uffe Bernchou; Brewer, Jonathan R.; Midtiby, Henrik Skov

    2009-01-01

    chains. By imaging the intensity variations as a function of the polarization angle, we map the lateral variations of the lipid tilt within domains. Results reveal that gel domains are composed of subdomains with different lipid tilt directions. We have applied a Fourier decomposition method......We investigate the texture of gel (g) domains in binary lipid membranes composed of the phospholipids DPPC and DOPC. Lateral organization of lipid bilayer membranes is a topic of fundamental and biological importance. Whereas questions related to size and composition of fluid membrane domain...... are well studied, the possibility of texture in gel domains has so far not been examined. When using polarized light for two-photon excitation of the fluorescent lipid probe Laurdan, the emission intensity is highly sensitive to the angle between the polarization and the tilt orientation of lipid acyl...

  12. Supporting the Development of Emotional Intelligence Competencies to Ease the Transition from Primary to High School

    Science.gov (United States)

    Qualter, P.; Whiteley, H. E.; Hutchinson, J. M.; Pope, D. J.

    2007-01-01

    This study aims to explore (1) whether pupils with high emotional intelligence (EI) cope better with the transition to high school; and (2) whether the introduction of an intervention programme to support the development of EI competencies can increase EI and self-worth, and so ease the negative effects of transition. Results suggest that pupils…

  13. Moving from Middle to High School: Making Sense of the Freshman Transition

    Science.gov (United States)

    Dudley, Rachel E.

    2012-01-01

    Educators have noticed students moving from eighth grade middle school programs to ninth grade high school environments encounter difficulties during the first year of the transition. Students who do not successfully transition to high school run the risk of repeating ninth grade, falling behind their peers and possibly dropping out of high…

  14. Classification of textures in satellite image with Gabor filters and a multi layer perceptron with back propagation algorithm obtaining high accuracy

    Directory of Open Access Journals (Sweden)

    Adriano Beluco, Paulo M. Engel, Alexandre Beluco

    2015-01-01

    Full Text Available The classification of images, in many cases, is applied to identify an alphanumeric string, a facial expression or any other characteristic. In the case of satellite images is necessary to classify all the pixels of the image. This article describes a supervised classification method for remote sensing images that integrates the importance of attributes in selecting features with the efficiency of artificial neural networks in the classification process, resulting in high accuracy for real images. The method consists of a texture segmentation based on Gabor filtering followed by an image classification itself with an application of a multi layer artificial neural network with a back propagation algorithm. The method was first applied to a synthetic image, like training, and then applied to a satellite image. Some results of experiments are presented in detail and discussed. The application of the method to the synthetic image resulted in the identification of 89.05% of the pixels of the image, while applying to the satellite image resulted in the identification of 85.15% of the pixels. The result for the satellite image can be considered a result of high accuracy.

  15. Characterization of Breast Implant Surfaces, Shapes, and Biomechanics: A Comparison of High Cohesive Anatomically Shaped Textured Silicone, Breast Implants from Three Different Manufacturers.

    Science.gov (United States)

    Atlan, Michael; Bigerelle, Maxence; Larreta-garde, Véronique; Hindié, Mathilde; Hedén, Per

    2016-02-01

    Several companies offer anatomically shaped breast implants but differences among manufacturers are often misunderstood. The shell texture is a crucial parameter for anatomically shaped implants to prevent rotation and to decrease the risk of capsular contracture, even though concerns have recently been raised concerning the complications associated with textured breast implants. The aim of this study was to characterize differences in terms of texture, cell adhesion, shape, and stiffness between some commonly used anatomically shaped implants from three different manufacturers. Five commercially available anatomically shaped breast implants from 3 different manufacturers (Allergan, Mentor, and Sebbin) were used. Scanning electron microscopy, X-ray microtomography, and scanning mechanical microscopy were used to characterize the shell texture. Human fibroblast adhesion onto the shells was evaluated. 3D models of the implants were obtained using CT-scan acquisitions to analyze their shape. Implant stiffness was evaluated using a tractiometer. Major differences were observed in the topography of the textures of the shells, but this was not conveyed by a statistically significant fibroblast adhesion difference. However, fibroblasts adhered better on anatomically shaped textured implants than on smooth implants (p Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

  16. A new texture and shape based technique for improving meningioma classification.

    Science.gov (United States)

    Fatima, Kiran; Arooj, Arshia; Majeed, Hammad

    2014-11-01

    Over the past decade, computer-aided diagnosis is rapidly growing due to the availability of patient data, sophisticated image acquisition tools and advancement in image processing and machine learning algorithms. Meningiomas are the tumors of brain and spinal cord. They account for 20% of all the brain tumors. Meningioma subtype classification involves the classification of benign meningioma into four major subtypes: meningothelial, fibroblastic, transitional, and psammomatous. Under the microscope, the histology images of these four subtypes show a variety of textural and structural characteristics. High intraclass and low interclass variabilities in meningioma subtypes make it an extremely complex classification problem. A number of techniques have been proposed for meningioma subtype classification with varying performances on different subtypes. Most of these techniques employed wavelet packet transforms for textural features extraction and analysis of meningioma histology images. In this article, a hybrid classification technique based on texture and shape characteristics is proposed for the classification of meningioma subtypes. Meningothelial and fibroblastic subtypes are classified on the basis of nuclei shapes while grey-level co-occurrence matrix textural features are used to train a multilayer perceptron for the classification of transitional and psammomatous subtypes. On the whole, average classification accuracy of 92.50% is achieved through the proposed hybrid classifier; which to the best of our knowledge is the highest. © 2014 Wiley Periodicals, Inc.

  17. Windows open for highly tunable magnetostructural phase transitions

    KAUST Repository

    Li, Y.

    2016-07-18

    An attempt was made to tailor the magnetostructural transitions over a wide temperature range under the principle of isostructural alloying. A series of wide Curie-temperature windows (CTWs) with a maximal width of 377 K between 69 and 446 K were established in the Mn1− yCoyNiGe1− xSix system. Throughout the CTWs, the magnetic-field-induced metamagnetic behavior and giant magnetocaloric effects are obtained. The (Mn,Co)Ni(Ge,Si) system shows great potential as multifunctional phase-transition materials that work in a wide range covering liquid-nitrogen and above water-boiling temperatures. Moreover, general understanding of isostructural alloying and CTWs constructed in (Mn,Co)Ni(Ge,Si) as well as (Mn,Fe)Ni(Ge,Si) is provided.

  18. The neutron texture diffractometer at the China Advanced Research Reactor

    Science.gov (United States)

    Li, Mei-Juan; Liu, Xiao-Long; Liu, Yun-Tao; Tian, Geng-Fang; Gao, Jian-Bo; Yu, Zhou-Xiang; Li, Yu-Qing; Wu, Li-Qi; Yang, Lin-Feng; Sun, Kai; Wang, Hong-Li; Santisteban, J. r.; Chen, Dong-Feng

    2016-03-01

    The first neutron texture diffractometer in China has been built at the China Advanced Research Reactor, due to strong demand for texture measurement with neutrons from the domestic user community. This neutron texture diffractometer has high neutron intensity, moderate resolution and is mainly applied to study texture in commonly used industrial materials and engineering components. In this paper, the design and characteristics of this instrument are described. The results for calibration with neutrons and quantitative texture analysis of zirconium alloy plate are presented. The comparison of texture measurements with the results obtained in HIPPO at LANSCE and Kowari at ANSTO illustrates the reliability of the texture diffractometer. Supported by National Nature Science Foundation of China (11105231, 11205248, 51327902) and International Atomic Energy Agency-TC program (CPR0012)

  19. Processing, properties, and application of textured 0.72lead(magnesium niobate)-0.28lead titanate ceramics

    Science.gov (United States)

    Brosnan, Kristen H.

    In this study, XRD and electron backscatter diffraction (EBSD) techniques were used to characterize the fiber texture in oriented PMN-28PT and the intensity data were fit with a texture model (the March-Dollase equation) that describes the texture in terms of texture fraction (f), and the width of the orientation distribution (r). EBSD analysis confirmed the orientation of the microstructure, with no distinguishable randomly oriented, fine grain matrix. Although XRD rocking curve and EBSD data analysis gave similar f and r values, XRD rocking curve analysis was the most efficient and gave a complete description of texture fraction and texture orientation (f = 0.81 and r = 0.21, respectively). XRD rocking curve analysis was the preferred approach for characterization of the texture volume and the orientation distribution of texture in fiber-oriented PMN-PT. The dielectric, piezoelectric and electromechanical properties for random ceramic, 69 vol% textured, 81 vol% textured, and single crystal PMN-28PT were fully characterized and compared. The room temperature dielectric constant at 1 kHz for highly textured PMN-28PT was epsilonr ≥ 3600 with low dielectric loss (tan delta = 0.004). The temperature dependence of the dielectric constant for 81 vol% textured ceramic followed a similar trend as the single crystal PMN-28PT up to the rhombohedral to tetragonal transition temperature (TRT) at 104°C. 81 vol% textured PMN-28PT consistently displayed 60 to 65% of the single crystal PMN-28PT piezoelectric coefficient (d33) and 1.5 to 3.0 times greater than the random ceramic d33 (measured by Berlincourt meter, unipolar strain-field curves, IEEE standard resonance method, and laser vibrometry). The 81 vol% textured PMN-28PT displayed similarly low piezoelectric hysteresis as single crystal PMN-28PT measured by strain-field curves at 5 kV/cm. 81 vol% textured PMN-28PT and single crystal PMN-28PT displayed similar mechanical quality factors of QM = 74 and 76, respectively. The

  20. Stress-anneal-induced magnetic anisotropy in highly textured Fe-Ga and Fe-Al magnetostrictive strips for bending-mode vibrational energy harvesters

    Directory of Open Access Journals (Sweden)

    Jung Jin Park

    2016-05-01

    Full Text Available Magnetostrictive Fe-Ga and Fe-Al alloys are promising materials for use in bending-mode vibrational energy harvesters. For this study, 50.8 mm × 5.0 mm × 0.5 mm strips of Fe-Ga and Fe-Al were cut from 0.50-mm thick rolled sheet. An atmospheric anneal was used to develop a Goss texture through an abnormal grain growth process. The anneal lead to large (011 grains that covered over 90% of sample surface area. The resulting highly-textured Fe-Ga and Fe-Al strips exhibited saturation magnetostriction values (λsat =  λ∥ − λ⊥ of ∼280 ppm and ∼130 ppm, respectively. To maximize 90° rotation of magnetic moments during bending of the strips, we employed compressive stress annealing (SA. Samples were heated to 500°C, and a 100-150 MPa compressive stress was applied while at 500°C for 30 minutes and while being cooled. The effectiveness of the SA on magnetic moment rotation was inferred by comparing post-SA magnetostriction with the maximum possible yield of rotated magnetic moments, which is achieved when λ∥ = λsat and λ⊥ = 0. The uniformity of the SA along the sample length and the impact of the SA on sensing/energy harvesting performance were then assessed by comparing pre- and post-SA bending-stress-induced changes in magnetization at five different locations along the samples. The SA process with a 150 MPa compressive load improved Fe-Ga actuation along the sample length from 170 to 225 ppm (from ∼60% to within ∼80% of λsat. The corresponding sensing/energy harvesting performance improved by as much as a factor of eight in the best sample, however the improvement was not at all uniform along the sample length. The SA process with a 100 MPa compressive load improved Fe-Al actuation along the sample length from 60 to 73 ppm (from ∼46% to ∼56% of λsat, indicating only a marginally effective SA and suggesting the need for modification of the SA protocol. In spite of this, the SA was effective at improving the sensing

  1. Stress-anneal-induced magnetic anisotropy in highly textured Fe-Ga and Fe-Al magnetostrictive strips for bending-mode vibrational energy harvesters

    Science.gov (United States)

    Park, Jung Jin; Na, Suok-Min; Raghunath, Ganesh; Flatau, Alison B.

    2016-05-01

    Magnetostrictive Fe-Ga and Fe-Al alloys are promising materials for use in bending-mode vibrational energy harvesters. For this study, 50.8 mm × 5.0 mm × 0.5 mm strips of Fe-Ga and Fe-Al were cut from 0.50-mm thick rolled sheet. An atmospheric anneal was used to develop a Goss texture through an abnormal grain growth process. The anneal lead to large (011) grains that covered over 90% of sample surface area. The resulting highly-textured Fe-Ga and Fe-Al strips exhibited saturation magnetostriction values (λsat = λ∥ - λ⊥) of ˜280 ppm and ˜130 ppm, respectively. To maximize 90° rotation of magnetic moments during bending of the strips, we employed compressive stress annealing (SA). Samples were heated to 500°C, and a 100-150 MPa compressive stress was applied while at 500°C for 30 minutes and while being cooled. The effectiveness of the SA on magnetic moment rotation was inferred by comparing post-SA magnetostriction with the maximum possible yield of rotated magnetic moments, which is achieved when λ∥ = λsat and λ⊥ = 0. The uniformity of the SA along the sample length and the impact of the SA on sensing/energy harvesting performance were then assessed by comparing pre- and post-SA bending-stress-induced changes in magnetization at five different locations along the samples. The SA process with a 150 MPa compressive load improved Fe-Ga actuation along the sample length from 170 to 225 ppm (from ˜60% to within ˜80% of λsat). The corresponding sensing/energy harvesting performance improved by as much as a factor of eight in the best sample, however the improvement was not at all uniform along the sample length. The SA process with a 100 MPa compressive load improved Fe-Al actuation along the sample length from 60 to 73 ppm (from ˜46% to ˜56% of λsat, indicating only a marginally effective SA and suggesting the need for modification of the SA protocol. In spite of this, the SA was effective at improving the sensing/energy harvesting

  2. Unconventional Face-On Texture and Exceptional In-Plane Order of a High Mobility n-Type Polymer

    KAUST Repository

    Rivnay, Jonathan

    2010-07-09

    Substantial in-plane crystallinity and dominant face-on stacking are observed in thin films of a high-mobility n-type rylene-thiophene copolymer. Spun films of the polymer, previously thought to have little or no order are found to exhibit an ordered microstructure at both interfaces, and in the bulk. The implications of this type of packing and crystalline morphology are discussed as they relate to thin-film transistors. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Improvement of texture and sensory properties of cakes by addition of potato peel powder with high level of dietary fiber and protein.

    Science.gov (United States)

    Ben Jeddou, Khawla; Bouaziz, Fatma; Zouari-Ellouzi, Soumaya; Chaari, Fatma; Ellouz-Chaabouni, Semia; Ellouz-Ghorbel, Raoudha; Nouri-Ellouz, Oumèma

    2017-02-15

    Demand for health oriented products such as low calories and high fiber product is increasing. The aim of the present work was to determine the effect of the addition of potato peel powders as protein and dietary fiber source on the quality of the dough and the cake. Powders obtained from the two types of peel flour showed interesting water binding capacity and fat absorption capacity. Potato peel flours were incorporated in wheat flours at different concentration. The results showed that peel powders additionally considerably improved the Alveograph profile of dough and the texture of the prepared cakes. In addition color measurements showed a significant difference between the control dough and the dough containing potato peels. The replacement of wheat flour with the potato powders reduced the cake hardness significantly and the L(*) and b(*) dough color values. The increased consumption of cake enriched with potato peel fiber is proposed for health reasons. The study demonstrated that protein/fiber-enriched cake with good sensory quality could be produced by the substitution of wheat flour by 5% of potato peel powder. In addition and technological point of view, the incorporation of potato peel powder at 5% increase the dough strength and elasticity-to-extensibility ratio (P/L).

  4. Textural analyses of carbon fiber materials by 2D-FFT of complex images obtained by high frequency eddy current imaging (HF-ECI)

    Science.gov (United States)

    Schulze, Martin H.; Heuer, Henning

    2012-04-01

    Carbon fiber based materials are used in many lightweight applications in aeronautical, automotive, machine and civil engineering application. By the increasing automation in the production process of CFRP laminates a manual optical inspection of each resin transfer molding (RTM) layer is not practicable. Due to the limitation to surface inspection, the quality parameters of multilayer 3 dimensional materials cannot be observed by optical systems. The Imaging Eddy- Current (EC) NDT is the only suitable inspection method for non-resin materials in the textile state that allows an inspection of surface and hidden layers in parallel. The HF-ECI method has the capability to measure layer displacements (misaligned angle orientations) and gap sizes in a multilayer carbon fiber structure. EC technique uses the variation of the electrical conductivity of carbon based materials to obtain material properties. Beside the determination of textural parameters like layer orientation and gap sizes between rovings, the detection of foreign polymer particles, fuzzy balls or visualization of undulations can be done by the method. For all of these typical parameters an imaging classification process chain based on a high resolving directional ECimaging device named EddyCus® MPECS and a 2D-FFT with adapted preprocessing algorithms are developed.

  5. Textural discrimination in unconstrained environment

    Science.gov (United States)

    Albalooshi, Fatema A.; Asari, Vijayan K.

    2014-03-01

    is iteratively grown by comparing all unallocated neighbouring pixels to that region. The di erence between seed pixels' mean intensity value and the region's textural descriptors is used as a measure of similarity of pixels. The pixel with the smallest di erence measured would be allocated to the particular segmentation region. Seeded region growing factors would change interactively according to the intensity levels of the chosen object of interest. The algorithm automatically computes segmentation thresholds based on local feature analysis. The system starts by measuring the intensity level of the selected object and accordingly adapts growing and stopping rules of the segmented region. The proposed segmentation method has been tested on a relatively large variety of databases with di erent objects of varying textures. The experimental results show that this simple framework is capable of achieving high quality performance and that this method can better handle the problem of segmenting objects of non-homogeneous textural bodies and correctly separate those objects from other objects and complex backgrounds. This framework can also be easily adapted to di erent applications by substituting suitable image feature de nitions.

  6. Texture growth of Bi-2212 tapes in high magnetic fields; Bi2212 tepu senzai no jibachu shosei

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.P. [Science and Technology Agency, Tokyo (Japan); Maeda, H. [Kitami Inst. of Tech., Hokkaido (Japan); Kakimoto, K.; Watanabe, K.; Motokaw, M. [Tohoku Univ., Miyagi (Japan); Kitaguchi, H.; Kumakura, H. [National Research Inst. of Metals, Tsukuba (Japan)

    1999-06-07

    In order to improve the Jc of high temperature superconducting bulk material, the improvement of the crystal orientation is indispensable. In this paper, in regard to Bi2212 tapes with high Jc, the magnetic field strength dependence during the baking of the crystal orientation was examined, and the examined result of the relevance with structures was reported. The used tapes were the Ag covering Bi2212 composite tapes synthesized with and without the PAIR (Pre-Annealing-Intermediate-Rolling) process and has already been conducted the final baking treatment and non-treatment. Though the tapes were placed in the burning division of an electric furnace installed in a refrigerating machine cryogenic superconducting magnet and pure O{sub 2} was flowed in the fixed magnetic field Ha to 10T, the baking in magnetic field was carried out by the partial melting- slow cooling method. As results of the XRD and SEM observation, the crystal C axis orientated prior to the Ha direction. In the vertical configuration regardless to the thin oxide core layer thickness, the crystal orientation was considerably disturbed, many crystals perpendicular to the tape plane could be seen. (NEDO)

  7. Birefringent Electroweak Textures

    CERN Document Server

    Thatcher, M J; Thatcher, Marcus J.; Morgan, Michael J.

    1999-01-01

    The behaviour of electromagnetic waves propagating through an electroweak homilia string network is examined. This string network is topologically stable as a cosmic texture, and is characterized by the spatial variation of the isospin rotation of the Higgs field. As a consequence the photon field couples to the intermediate vector bosons, producing a finite range electromagnetic field. It is found that the propagation speed of the photon depends on its polarization vector, whence an homilia string network acts as a birefringent medium. We estimate the birefringent scale for this texture and show that it depends on the frequency of the electromagnetic wave and the length scale of the homilia string network.

  8. Optimal Capacity Conversion for Product Transitions Under High Service Requirements

    OpenAIRE

    Li, Hongmin; Graves, Stephen C.; Huh, Woonghee Tim

    2012-01-01

    We consider the capacity planning problem during a product transition in which demand for a new-generation product gradually replaces that for the old product. Capacity for the new product can be acquired both by purchasing new production lines and by converting existing production lines for the old product. Furthermore, in either case, the new product capacity is “retrofitted” to be flexible, i.e., to be able to also produce the old product. This capacity planning problem arises regularly at...

  9. Anisotropic 3D texture synthesis with application to volume rendering

    DEFF Research Database (Denmark)

    Laursen, Lasse Farnung; Ersbøll, Bjarne Kjær; Bærentzen, Jakob Andreas

    2011-01-01

    We present a novel approach to improving volume rendering by using synthesized textures in combination with a custom transfer function. First, we use existing knowledge to synthesize anisotropic solid textures to fit our volumetric data. As input to the synthesis method, we acquire high quality....... This method is applied to a high quality visualization of a pig carcass, where samples of meat, bone, and fat have been used to produce the anisotropic 3D textures....

  10. Effect of inulin on textural and sensory characteristics of sorghum based high fibre biscuits using response surface methodology.

    Science.gov (United States)

    Banerjee, Chandralekha; Singh, Rakhi; Jha, Alok; Mitra, Jayeeta

    2014-10-01

    Five blends of sorghum (Sorghum bicolor) flour (25.0-45.0 %) and whole wheat flour were used to make biscuits using inulin (5.0-10.0 %) and guar gum (1.0-2.0 %). An experimental investigation was carried out with the aim of evaluating the effect of fat replacer (inulin) and sorghum flour on the quality of high fibre and low calorie biscuits. For this purpose, the biscuit dough and the biscuit samples were analyzed. The analysis was based on hardness of the dough, hardness of the biscuit, fracturability and overall acceptability (OAA) scores. Results showed that increasing the amount of sorghum flour in biscuit increased the dough hardness and biscuit hardness, whereas, biscuit fracturability decreased and OAA scores increased up to the level at which sorghum flour ranged from 35.0 to 40.0 % after which it decreased. An increase in the amount of inulin was followed by an increase in biscuit hardness, while, fracturability and OAA scores decreased and there was little effect on the dough hardness. Optimum conditions generated from the analysis was 40.8 % sorghum flour, 6.5 % inulin and 1.0 % guar gum. The predicted response in terms of dough hardness, fracturability, biscuit hardness and OAA were 212.4 g, 36.4 mm, 4.8 kg and 7.06, respectively. The desirability of the optimum condition was 0.827.

  11. Glass transition of ionic liquids under high pressure

    Science.gov (United States)

    Ribeiro, Mauro C. C.; Pádua, Agílio A. H.; Gomes, Margarida F. Costa

    2014-06-01

    The glass transition pressure at room temperature, pg, of six ionic liquids based on 1-alkyl-3-methylimidazolium cations and the anions [BF4]-, [PF6]-, and bis(trifluromethanesulfonyl)imide, [NTf2]-, has been obtained from the pressure dependence of the bandwidth of the ruby fluorescence line in diamond anvil cells. Molar volume, Vm(pg), has been estimated by a group contribution model (GCM) developed for the ionic liquids. A density scaling relation, TVγ, has been considered for the states Vm(pg, 295 K) and Vm(Tg, 0.1 MPa) using the simplifying condition that the viscosity at the glass transition is the same at pg at room temperature and at atmospheric pressure at Tg. Assuming a constant γ over this range of density, a reasonable agreement has been found for the γ determined herein and that of a previous density scaling analysis of ionic liquids viscosities under moderate conditions. Further support for the appropriateness of extrapolating the GCM equation of state to the GPa pressure range is provided by comparing the GCM and an equation of state previously derived in the power law density-scaling regime.

  12. Interfacial stick–slip transition in hydroxyapatite filled high density polyethylene composite

    Indian Academy of Sciences (India)

    Roy Joseph; M T Martyn; K E Tanner; P D Coates

    2006-02-01

    Effect of filler addition and temperature on the stick–slip transition in high density polyethylene melt was studied. Results showed that shear stresses corresponding to stick–slip transition increases with the addition of filler. Increase in temperature also increases the shear stresses for stick–slip transition. The features of the flow curves of composites and that of unfilled system remain identical. Filler addition lowers the shear rate at which the transition occurs. The composite extrudate did not show characteristic extrudate distortions associated with the unfilled polymer.

  13. Fully Consistent Finite-Strain Landau Theory for High-Pressure Phase Transitions

    Science.gov (United States)

    Tröster, A.; Schranz, W.; Karsai, F.; Blaha, P.

    2014-07-01

    Landau theory (LT) is an indispensable cornerstone in the thermodynamic description of phase transitions. As with structural transitions, most applications require one to consistently take into account the role of strain. If temperature drives the transition, the relevant strains are, as a rule, small enough to be treated as infinitesimal, and therefore one can get away with linearized elasticity theory. However, for transitions driven by high pressure, strains may become so large that it is absolutely mandatory to treat them as finite and deal with the nonlinear nature of the accompanying elastic energy. In this paper, we explain how to set up and apply what is, in fact, the only possible consistent Landau theory of high-pressure phase transitions that systematically allows us to take these geometrical and physical nonlinearities into account. We also show how to incorporate available information on the pressure dependence of elastic constants taken from experiment or simulation. We apply our new theory to the example of the high-pressure cubic-tetragonal phase transition in strontium titanate, a model perovskite that has played a central role in the development of the theory of structural phase transitions. Armed with pressure-dependent elastic constants calculated by density-functional theory, we give an accurate description of recent high-precision experimental data and predict a number of elastic transition anomalies accessible to experiments.

  14. Theoretical description of the octupole phase transition in Lanthanide nuclei at high spin

    CERN Document Server

    Garrote, E; Robledo, L M

    1999-01-01

    The phase transition to reflection asymmetric intrinsic nuclear shapes at high angular momentum is analyzed in the framework of the cranked Hartree-Fock-Bogoliubov approximation, with the Gogny interaction, using approximate parity projection before variation. The N=88 isotones are studied and good agreement is found for the energy splitting and dipole moments before and after the transition.

  15. Metamagnetic transitions of DyAg in pulsed high magnetic field

    Science.gov (United States)

    Yamagishi, A.; Yonenobu, K.; Kondo, O.; Morin, P.; Date, M.

    1990-12-01

    Metamagnetic transitions of a single crystal DyAg are investigated by using pulsed magnetic fields up to 410 kOe. Four step-magnetizations are found with the field along the [111] direction. These transitions are well understood by introducing a new model that the quadrupole order is quenched under high magnetic field.

  16. Metamagnetic transitions of DyAg in pulsed high magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Yamagishi, A.; Yonenobu, K.; Kondo, O.; Date, M. (Research Center for Extreme Materials, Osaka Univ. (Japan)); Morin, P. (Lab. Louis Neel, CNRS, 38 - Grenoble (France))

    1990-12-01

    Metamagnetic transitions of a single crystal DyAg are investigated by using pulsed magnetic fields up to 410 kOe. Four step-magnetizations are found with the field along the (111) direction. These transitions are well understood by introducing a new model that the quadrupole order is quenched under high magnetic field. (orig.).

  17. Improving the Transition from High School to Postsecondary Education. Working Paper Series 04-1

    Science.gov (United States)

    Policy Analysis for California Education, PACE (NJ3), 2004

    2004-01-01

    This publication presents three working papers on the inadequacies and difficulties of successful transition from high school to college. These papers are derived from The Bridge Project, a six-state study of K-16 issues. These three papers do not attempt to cover all aspects of K-16 and transition issues. Consequently, the policy implications at…

  18. Texture and mechanical properties of tape substrates from binary and ternary copper alloys for second-generation high-temperature superconductors

    Science.gov (United States)

    Khlebnikova, Yu. V.; Rodionov, D. P.; Gervas'eva, I. V.; Suaridze, T. R.; Egorova, L. Yu.; Akshentsev, Yu. N.; Kazantsev, V. A.

    2015-01-01

    The process of texture formation in tapes made of a number of binary and ternary copper alloys upon cold rolling to degrees of deformation of 98.6-99% and subsequent recrystallization annealing has been studied. The possibility of designing multicomponent alloys based on the binary Cu-30% Ni alloy additionally alloyed with elements that strengthen the fcc matrix, such as iron or chromium, has been shown. The opportunity of obtaining a perfect cube texture in a thin tape made of binary and ternary copper alloys opens prospects for their use as substrates in the technology of second-generation HTSC cables. Optimum regimes of annealing have been determined, which make it possible to obtain in the Cu- M and Cu-(30-40)Ni- M ( M = Fe, Cr, Mn) alloys a perfect biaxial texture with the fraction of cube grains {001} on the surface of the tape more than 94%. The estimation of the mechanical properties of the textured tapes of the investigated alloys demonstrates a yield strength that is 2.5-4.5 times greater than that in the textured tape of pure copper.

  19. TEXTURE PRESERVING IMAGE CODING USING ORTHOGONAL POLYNOMIALS

    Directory of Open Access Journals (Sweden)

    R. Krishnamoorthi

    2010-08-01

    Full Text Available In order to replace the artifacts in the textured background, a new texture preserving image coder using the set of orthogonal polynomials is proposed in this paper. The proposed scheme is based on the model that represents textures using points spread operator relating to a linear system. In the proposed texture based image coding scheme, the encoder first identifies textured regions, which are then analyzed to produce the model features. Then these features are later transmitted to decoder which decodes to form a synthetic texture and results into synthetic stage. The proposed modeling delivers to attain high compression ratio by maintaining constantly excellent visual quality. 92.31% with a PSNR value of 31.93dB when the quality factor is 5 for D96 image is achieved by the proposed scheme. By keeping up the quality factor as a constant constrained, we obtain 91.11% of compression ratio with a PSNR value of 33.26dB for different set of image that is, D38 image.

  20. Texture affects color emotion

    NARCIS (Netherlands)

    Lucassen, M.P.; Gevers, T.; Gijsenij, A.

    2011-01-01

    Several studies have recorded color emotions in subjects viewing uniform color (UC) samples. We conduct an experiment to measure and model how these color emotions change when texture is added to the color samples. Using a computer monitor, our subjects arrange samples along four scales: warm-cool,

  1. Textured Sling Pots

    Science.gov (United States)

    Skophammer, Karen

    2010-01-01

    Clay is one of the most satisfying mediums for children to work with. It's relatively inexpensive, and the texture and changes that take place with the clay during firing make it irresistible. Molding clay from rolled-out slabs of clay is an easy way to make simple, shallow vessels or display pots. In this article, the author describes how her…

  2. Texture affects color emotion

    NARCIS (Netherlands)

    Lucassen, M.P.; Gevers, T.; Gijsenij, A.

    2011-01-01

    Several studies have recorded color emotions in subjects viewing uniform color (UC) samples. We conduct an experiment to measure and model how these color emotions change when texture is added to the color samples. Using a computer monitor, our subjects arrange samples along four scales: warm-cool,

  3. Highly textured Li(Ni0.5Mn0.3Co0.2)O2 thin films on stainless steel as cathode for lithium-ion battery

    Science.gov (United States)

    Jacob, Clement; Lynch, Tommy; Chen, Aiping; Jian, Jie; Wang, Haiyan

    2013-11-01

    Epitaxial and highly textured Li(NixMnyCo1-x-y)O2 thin film cathodes are deposited by a one-step, high temperature pulsed laser deposition technique. Structural characterization using X-ray diffraction, transmission electron microscopy and selected area electron diffraction (SAED) reveals highly textured film along (003). The best film quality has been achieved at high temperature, with temperature as high as 750 °C. Different substrates and buffer layers have been investigated and Li(Ni0.5Mn0.3Co0.2)O2 (NMC) on stainless steel with a thin Au-buffer layer gives the best film quality. The NMC thin film cathodes give a high capacity of 167 mAh g-1 and 125 mAh g-1 at 0.1 C and 0.5 C, respectively. In addition, the cyclic voltammetry and charge discharge curves obtained after different cycles indicate good electrochemical stability with capacity retention of 89% after 100 cycles at 0.5 C. The electrochemical characteristics are correlated to the microstructure of the film and the effects of texture, grain size and density are discussed.

  4. Contrast negation and texture synthesis differentially disrupt natural texture appearance.

    Science.gov (United States)

    Balas, Benjamin

    2012-01-01

    Natural textures have characteristic image statistics that make them discriminable from unnatural textures. For example, both contrast negation and texture synthesis alter the appearance of natural textures even though each manipulation preserves some features while disrupting others. Here, we examined the extent to which contrast negation and texture synthesis each introduce or remove critical perceptual features for discriminating unnatural textures from natural textures. We find that both manipulations remove information that observers use for distinguishing natural textures from transformed versions of the same patterns, but do so in different ways. Texture synthesis removes information that is relevant for discrimination in both abstract patterns and ecologically valid textures, and we also observe a category-dependent asymmetry for identifying an "oddball" real texture among synthetic distractors. Contrast negation exhibits no such asymmetry, and also does not impact discrimination performance in abstract patterns. We discuss our results in the context of the visual system's tuning to ecologically relevant patterns and other results describing sensitivity to higher-order statistics in texture patterns.

  5. Raman Scattering Spectroscopy of Phase Transition in n-Pentadecane under High Temperature and High Pressure

    Institute of Scientific and Technical Information of China (English)

    QIAO Er-Wei; ZHENG Hai-Fei; XU Bei

    2009-01-01

    The Raman spectroscopy of n-pentadecane is investigated in a moissanite anvil cell at normal temperatures and a diamond anvil cell under pressure to about 3000 MPa and at temperature from 298 to 573 K. Result indicates that at room temperature the vibration modes, assigned to the symmetric and asymmetric stretching of CH3 and CH2 stretching, shift to higher frequency and display a pressure dependent quasi-linear curve. A liquid-solid phase transition appears at a pressure of 150 MPa. The high temperature solidus line of n-pentadecane follows a quadratic function of P = 0.02369T2 - 9.117T + 725.58, in agreement with previous conclusion derived from studies of other hydrocarbons. Upon phase transition, fitting the experimental data obtained in a temperature range of 283-553 K to the Clausius-Clapeyron equation allows one to define the thermodynamic parameters of n-pentadecane of dP/dT = 0.04738T - 9.117.

  6. Lasing and high temperature phase transitions in atomic systems with dressed state polaritons

    CERN Document Server

    Chestnov, I Yu

    2013-01-01

    We consider the fundamental problem of high temperature phase transitions in the system of high density two-level atoms off-resonantly interacting with a pump field in the presence of optical collisions (OCs) and placed in the cavity. OCs are considered in the framework of thermalization of atomic dressed state (DS) population. For the case of a strong atom-field coupling condition we analyze the problem of thermodynamically equilibrium superradiant phase transition for the order parameter representing a real amplitude of cavity mode and taking place as a result of atomic DSs thermalization process. Such transition is also connected with condensed (coherent) properties of low branch (LB) DS-polaritons occurring in the cavity. For describing non-equilibrium phase transitions we derive Maxwell-Bloch like equations which account for cavity decay rate, collisional decay rate and spontaneous emission. Various aspects of transitions to laser field formation by using atomic DS levels for both positive and negative d...

  7. Validation of a RANS transition model using a high-order weighted compact nonlinear scheme

    Science.gov (United States)

    Tu, GuoHua; Deng, XiaoGang; Mao, MeiLiang

    2013-04-01

    A modified transition model is given based on the shear stress transport (SST) turbulence model and an intermittency transport equation. The energy gradient term in the original model is replaced by flow strain rate to saving computational costs. The model employs local variables only, and then it can be conveniently implemented in modern computational fluid dynamics codes. The fifth-order weighted compact nonlinear scheme and the fourth-order staggered scheme are applied to discrete the governing equations for the purpose of minimizing discretization errors, so as to mitigate the confusion between numerical errors and transition model errors. The high-order package is compared with a second-order TVD method on simulating the transitional flow of a flat plate. Numerical results indicate that the high-order package give better grid convergence property than that of the second-order method. Validation of the transition model is performed for transitional flows ranging from low speed to hypersonic speed.

  8. Image statistics underlying natural texture selectivity of neurons in macaque V4

    Science.gov (United States)

    Okazawa, Gouki; Tajima, Satohiro; Komatsu, Hidehiko

    2015-01-01

    Our daily visual experiences are inevitably linked to recognizing the rich variety of textures. However, how the brain encodes and differentiates a plethora of natural textures remains poorly understood. Here, we show that many neurons in macaque V4 selectively encode sparse combinations of higher-order image statistics to represent natural textures. We systematically explored neural selectivity in a high-dimensional texture space by combining texture synthesis and efficient-sampling techniques. This yielded parameterized models for individual texture-selective neurons. The models provided parsimonious but powerful predictors for each neuron’s preferred textures using a sparse combination of image statistics. As a whole population, the neuronal tuning was distributed in a way suitable for categorizing textures and quantitatively predicts human ability to discriminate textures. Together, we suggest that the collective representation of visual image statistics in V4 plays a key role in organizing the natural texture perception. PMID:25535362

  9. Adaptive texture filtering for defect inspection in ultrasound images

    Science.gov (United States)

    Zmola, Carl; Segal, Andrew C.; Lovewell, Brian; Nash, Charles

    1993-05-01

    The use of ultrasonic imaging to analyze defects and characterize materials is critical in the development of non-destructive testing and non-destructive evaluation (NDT/NDE) tools for manufacturing. To develop better quality control and reliability in the manufacturing environment advanced image processing techniques are useful. For example, through the use of texture filtering on ultrasound images, we have been able to filter characteristic textures from highly-textured C-scan images of materials. The materials have highly regular characteristic textures which are of the same resolution and dynamic range as other important features within the image. By applying texture filters and adaptively modifying their filter response, we have examined a family of filters for removing these textures.

  10. Bismuth Vanadate: A High-Pressure, High-Temperature Crystallographic Study of the Ferroelastic-Paraelastic Transition

    Science.gov (United States)

    Hazen, R. M.; Mariathasan, J. W. E.

    1982-05-01

    Lattice dimensions of bismuth vanadate have been determined under 37 different high-pressure or high-temperature conditions or a combination of these conditions. New high-pressure, high-temperature, single-crystal x-ray techniques were used to bracket the reversible monoclinic (ferroelastic) to tetragonal (paraelastic) transition.

  11. Configuration effects on texture transparency.

    Science.gov (United States)

    Kawabe, Takahiro; Miura, Kayo

    2004-01-01

    This study examined the factors producing the perception of transparency between overlaid regions composed of Gabor micro-patterns as functions of their spatial frequency, separation of overlaid regions, and types of orientation modulation. The results showed that the likelihood of perceiving transparency was high both when (1) the difference in Gabor spatial frequency between regions was large, and (2) the region boundary, which was formed by short-range orientation differences in the Gabor micro-patterns, clearly emerged. We conclude that texture transparency appears to result from an interaction between a boundary-detection mechanism defining the shape of each region and a surface-detection mechanism assigning the boundary.

  12. Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE)

    Energy Technology Data Exchange (ETDEWEB)

    Overman, N. R.; Whalen, S. A.; Bowden, M. E.; Olszta, M. J.; Kruska, K.; Clark, T.; Stevens, E. L.; Darsell, J. T.; Joshi, V. V.; Jiang, X.; Mattlin, K. F.; Mathaudhu, S. N.

    2017-07-01

    Shear Assisted Processing and Extrusion (ShAPE) -a novel processing route that combines high shear and extrusion conditions- was evaluated as a processing method to densify melt spun magnesium alloy (AZ91E) flake materials. This study illustrates the microstructural regimes and transitions in crystallographic texture that occur as a result of applying simultaneous linear and rotational shear during extrusion. Characterization of the flake precursor and extruded tube was performed using scanning and transmission electron microscopy, x-ray diffraction and microindentation techniques. Results show a unique transition in the orientation of basal texture development. Despite the high temperatures involved during processing, uniform grain refinement and material homogenization are observed. These results forecast the ability to implement the ShAPE processing approach for a broader range of materials with novel microstructures and high performance.

  13. Development of low friction snake-inspired deterministic textured surfaces

    Science.gov (United States)

    Cuervo, P.; López, D. A.; Cano, J. P.; Sánchez, J. C.; Rudas, S.; Estupiñán, H.; Toro, A.; Abdel-Aal, H. A.

    2016-06-01

    The use of surface texturization to reduce friction in sliding interfaces has proved successful in some tribological applications. However, it is still difficult to achieve robust surface texturing with controlled designer-functionalities. This is because the current existing gap between enabling texturization technologies and surface design paradigms. Surface engineering, however, is advanced in natural surface constructs especially within legless reptiles. Many intriguing features facilitate the tribology of such animals so that it is feasible to discover the essence of their surface construction. In this work, we report on the tribological behavior of a novel class of surfaces of which the spatial dimensions of the textural patterns originate from micro-scale features present within the ventral scales of pre-selected snake species. Mask lithography was used to produce implement elliptical texturizing patterns on the surface of titanium alloy (Ti6Al4V) pins. To study the tribological behavior of the texturized pins, pin-on-disc tests were carried out with the pins sliding against ultra-high molecular weight polyethylene discs with no lubrication. For comparison, two non-texturized samples were also tested under the same conditions. The results show the feasibility of the texturization technique based on the coefficient of friction of the textured surfaces to be consistently lower than that of the non-texturized samples.

  14. Characterization of color texture: color texture based sorting of tiles

    Science.gov (United States)

    Bourada, Y.; Lafon, Dominique; Eterradossi, O.

    1998-09-01

    Many materials used by the building industry show a color texture which affects the product commercial value. This texture can be seen as the spatial arrangement of regions of acceptable color differences. This work describes an appearance based automated sorting via color texture analysis, using ceramic tiles as example. Textural analysis of the tiles digital images expressed in CIEL*a*b* color system is performed through the analysis of intrinsic features of each region and relationships between regions. Results obtained through the automated process are compared to a visual sorting which leads to calculation of application dependant color and texture tolerances.

  15. Parallel-Sequential Texture Analysis

    NARCIS (Netherlands)

    Broek, E.L. van den; Rikxoort, E.M. van

    2005-01-01

    Color induced texture analysis is explored, using two texture analysis techniques: the co-occurrence matrix and the color correlogram as well as color histograms. Several quantization schemes for six color spaces and the human-based 11 color quantization scheme have been applied. The VisTex texture

  16. Parallel-Sequential Texture Analysis

    NARCIS (Netherlands)

    van den Broek, Egon; Singh, Sameer; Singh, Maneesha; van Rikxoort, Eva M.; Apte, Chid; Perner, Petra

    2005-01-01

    Color induced texture analysis is explored, using two texture analysis techniques: the co-occurrence matrix and the color correlogram as well as color histograms. Several quantization schemes for six color spaces and the human-based 11 color quantization scheme have been applied. The VisTex texture

  17. From food structure to texture

    NARCIS (Netherlands)

    Wilkinson, C.; Dijksterhuis, G.B.; Minekus, M.

    2000-01-01

    Understanding the relationship between food texture perception and food structure is of increasing importance for companies wishing to produce texturally attractive food products. The perception of texture is a complex process involving the senses of vision, hearing, somesthesis and kinesthesis. Tex

  18. X-ray resonant photoexcitation: linewidths and energies of Kα transitions in highly charged Fe ions.

    Science.gov (United States)

    Rudolph, J K; Bernitt, S; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H-C; Yavaş, H; Ullrich, J; Crespo López-Urrutia, J R

    2013-09-06

    Photoabsorption by and fluorescence of the Kα transitions in highly charged iron ions are essential mechanisms for x-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main Kα transitions in highly charged iron ions from heliumlike to fluorinelike (Fe24+ to Fe17+) using monochromatic x rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in x-ray binary stars and active galactic nuclei.

  19. Phase transition of solid bismuth under high pressure

    Science.gov (United States)

    Chen, Hai-Yan; Xiang, Shi-Kai; Yan, Xiao-Zhen; Zheng, Li-Rong; Zhang, Yi; Liu, Sheng-Gang; Bi, Yan

    2016-10-01

    As a widely used pressure calibrator, the structural phase transitions of bismuth from phase I, to phase II, to phase III, and then to phase V with increasing pressure at 300 K have been widely confirmed. However, there are different structural versions for phase III, most of which are determined by x-ray diffraction (XRD) technology. Using x-ray absorption fine structure (XAFS) measurements combined with ab initio calculations, we show that the proposed incommensurate composite structure of bismuth of the three configurations is the best option. An abnormal continuous increase of the nearest-neighbor distance of phase III with elevated pressure is also observed. The electronic structure transformation from semimetal to metal is responsible for the complex behavior of structure transformation. Project supported by the National Natural Science Foundation of China (Grant Nos. 10904133, 11304294, 11274281, 11404006, and U1230201), the Development Foundation of China Academy of Engineering Physics (Grant Nos. 2015B0101004, 2013B0401062, and 2012A0101001), the Research Foundation of the Laboratory of Shock Wave and Detonation, China (Grant No. 9140C670201140C67282).

  20. K-theory and phase transitions at high energies

    Directory of Open Access Journals (Sweden)

    T. V. Obikhod

    2016-06-01

    Full Text Available The duality between E8xE8 heteritic string on manifold K3xT2 and Type IIA string compactified on a Calabi-Yau manifold induces a correspondence between vector bundles on K3xT2 and Calabi-Yau manifolds. Vector bundles over compact base space K3xT2 form the set of isomorphism classes, which is a semi-ring under the operation of Whitney sum and tensor product. The construction of semi-ring V ect X of isomorphism classes of complex vector bundles over X leads to the ring KX = K(V ect X, called Grothendieck group. As K3 has no isometries and no non-trivial one-cycles, so vector bundle winding modes arise from the T2 compactification. Since we have focused on supergravity in d = 11, there exist solutions in d = 10 for which space-time is Minkowski space and extra dimensions are K3xT2. The complete set of soliton solutions of supergravity theory is characterized by RR charges, identified by K-theory. Toric presentation of Calabi-Yau through Batyrev's toric approximation enables us to connect transitions between Calabi-Yau manifolds, classified by enhanced symmetry group, with K-theory classification.

  1. Laser surface texturing of cast iron steel: dramatic edge burr reduction and high speed process optimisation for industrial production using DPSS picosecond lasers

    Science.gov (United States)

    Bruneel, David; Kearsley, Andrew; Karnakis, Dimitris

    2015-07-01

    In this work we present picosecond DPSS laser surface texturing optimisation of automotive grade cast iron steel. This application attracts great interest, particularly in the automotive industry, to reduce friction between moving piston parts in car engines, in order to decrease fuel consumption. This is accomplished by partially covering with swallow microgrooves the inner surface of a piston liner and is currently a production process adopting much longer pulse (microsecond) DPSS lasers. Lubricated interface conditions of moving parts require from the laser process to produce a very strictly controlled surface topography around the laser formed grooves, whose edge burr height must be lower than 100 nm. To achieve such a strict tolerance, laser machining of cast iron steel was investigated using an infrared DPSS picosecond laser (10ps duration) with an output power of 16W and a repetition rate of 200 kHz. The ultrashort laser is believed to provide a much better thermal management of the etching process. All studies presented here were performed on flat samples in ambient air but the process is transferrable to cylindrical geometry engine liners. We will show that reducing significantly the edge burr below an acceptable limit for lubricated engine production is possible using such lasers and remarkably the process window lies at very high irradiated fluences much higher that the single pulse ablation threshold. This detailed experimental work highlights the close relationship between the optimised laser irradiation conditions as well as the process strategy with the final size of the undesirable edge burrs. The optimised process conditions are compatible with an industrial production process and show the potential for removing extra post)processing steps (honing, etc) of cylinder liners on the manufacturing line saving time and cost.

  2. Gravitational waves from the first order phase transition of the Higgs field at high energy scales

    Science.gov (United States)

    Jinno, Ryusuke; Nakayama, Kazunori; Takimoto, Masahiro

    2016-02-01

    In a wide class of new physics models, there exist scalar fields that obtain vacuum expectation values of high energy scales. We study the possibility that the standard model Higgs field has experienced first order phase transition at the high energy scale due to the couplings with these scalar fields. We estimate the amount of gravitational waves produced by the phase transition, and discuss observational consequences.

  3. Gravitational Waves from the First Order Phase Transition of the Higgs Field at High Energy Scales

    CERN Document Server

    Jinno, Ryusuke; Takimoto, Masahiro

    2015-01-01

    In a wide class of new physics models, there exist scalar fields which obtain vacuum expectation values of high energy scales. We study the possibility that the standard model Higgs field has experienced first-order phase transition at the high energy scale due to the couplings with these scalar fields.We estimate the amount of gravitational waves produced by the phase transition, and discuss observational consequences.

  4. 熔融织构YBa2Cu3O7-δ晶体中磁通涡旋锁定转变反常行为研究∗%Abnormal b ehaviors in lo ck-in transition of the vortices in melt textured growth of YBa2Cu3O7-δ crystals

    Institute of Scientific and Technical Information of China (English)

    吴董杰; 徐克西; 唐天威

    2016-01-01

    The magnetization behavior of the layered anisotropic high-Tc superconductor in the mixed state Hc1 In this paper, we systematically measure the magnetic torque signal in melt texture growth YBCO (MTG-YBCO) bulk and observe an abnormal lock-in transition behavior in the vortex system. The critical angle of the lock-in transition is found to be directly proportional to the strength of the magnetic field, which is contrary to the observations in the common cases. According to the framework of the Ginzburg-Landau theory and the kink structure model of the vortex line, we discuss the abnormal phenomenon, and propose that there is a type of extend-correlated defect structure, which is parallel to the a-b plane, in the MTG-YBCO crystal. The relationship between the critical angle of the lock-in transition to the temperature and the magnetic field is established theoretically, and the theoretical results coincide well with the torque measurements.%通过改变磁场与c轴方向夹角测量了熔融织构YBa2Cu3O7−δ(YBCO)晶体的磁力矩信号响应,观察到了磁通涡旋系统的锁定(lock-in)转变行为以及锁定转变角正比于外磁场强度的反常现象。基于Ginzburg-Landau理论和磁通涡旋线Kink结构模型,对上述锁定转变反常现象进行了分析讨论,提出了熔融织构YBCO晶体中存在平行于a-b面的延展性关联缺陷结构假设,导出了锁定转变临界角与温度和磁场之间的关系,理论分析模型结果与实验测量结果基本符合。

  5. Design and mechanism of cost-effective and highly efficient ultrathin (< 0.5 μm GaAs solar cells employing nano/micro-hemisphere surface texturing

    Directory of Open Access Journals (Sweden)

    J. S. Li

    2013-03-01

    Full Text Available Low aspect-ratio nano/micro-hemisphere surface texturing is introduced for improving light management in ultrathin GaAs solar cells. A 200 nm thick film textured by the optimal GaAs nano/micro-hemisphere array with both the hemisphere diameter and array periodicity of 500 nm can achieve >90% light absorption from 1.44 to 2.5 eV, lying in the high photon density energy regime of the solar spectrum for GaAs. The excellent light confinement and low aspect ratio, which is thus convenient for conformal deposition of electrodes for efficient photogenerated carrier collection of the proposed structure will facilitate realization of highly efficient and cost-effective ultrathin GaAs solar cells.

  6. The transit dose component of high dose rate brachytherapy: Direct measurements and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Bastin, K.T.; Podgorsak, M.B.; Thomadsen, B.R. (Univ. of Wisconsin Hospitals and Clinics, Madison, WI (United States))

    1993-07-15

    The purpose was to measure the transit dose produced by a moving high dose rate brachytherapy source and assess its clinical significance. The doses produced from source movement during Ir-192 HDR afterloading were measured using calibrated thermoluminescent dosimeter rods. Transit doses at distances of 0.5-4.0 cm from an endobronchial applicator were measured using a Lucite phantom accommodating 1 x 1 x 6 mm thermoluminescent rods. Surface transit dose measurements were made using esophageal and endobronchial catheters, a gynecologic tandem, and an interstitial needle. No difference was detected in thermoluminescent dosimeter rod responses to 4 MV and Ir-192 spectra (427 nC/Gy) in a range of dose between 2 and 300 cGy. The transit dose at 0.5 cm from an endobronchial catheter was 0.31 cGy/(Curie-fraction) and followed an inverse square fall-off with increasing distance. Surface transit doses ranged from 0.38 cGy/(Curie-fraction) for an esophageal catheter to 1.03 cGy/(Curie-fraction) for an endobronchial catheter. Source velocity is dependent on the interdwell distance and varies between 220-452 mm/sec. A numeric algorithm was developed to calculate total transit dose, and was based on a dynamic point approximation for the moving high dose rate source. This algorithm reliably predicted the empirical transit doses and demonstrated that total transit dose is dependent on source velocity, number of fractions, and source activity. Surface transit doses are dependent on applicator diameter and wall material and thickness. Total transit doses within or outside the desired treatment volume are typically <100 cGy, but may exceed 200 cGy when using a large number of fractions with a high activity source. 9 refs., 8 figs., 1 tab.

  7. AC susceptibilities of grain-textured superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, N. [Department of Electrical Engineering, Kyushu Sangyo University, 2-3-1 Matsukadai, 813-8503 Fukuoka (Japan)], E-mail: saka@te.kyusan-u.ac.jp; Fukuda, Y.; Koga, M.; Akune, T. [Department of Electrical Engineering, Kyushu Sangyo University, 2-3-1 Matsukadai, 813-8503 Fukuoka (Japan); Khan, H.R. [Institut von Ionenstrahl und Vakuum Technologie, 73728 Esslingen (Germany); Lueders, K. [Freie Universitaet Berlin, Arnimallee, Fac.Physik, D-14195 Berlin (Germany)

    2008-09-15

    In-phase {chi}{sub n}' and out-phase {chi}{sub n}'' components of nth harmonics of AC susceptibility with measuring parameters of a DC magnetic field B{sub dc}, an amplitude B{sub a} and a frequency f of the superimposed AC magnetic fields give substantial information of the superconducting properties. In low-T{sub c} metallic superconductors, {chi}{sub 1}' shows smooth transition and {chi}{sub 1}'' does single peak. High-T{sub c} oxide superconductors with anisotropic and grain-textured structures show deformed complex characteristics. Double peaks in {chi}{sub 1}'' and shoulders in {chi}{sub 1}' appear in AC susceptibility of Hg-1223 superconductors. Instead of simple Bean model, a grained model, where the superconducting grains are immersed in weak superconducting matrix, are proposed. The susceptibilities numerically analyzed using the model show varied and deformed curves and are successfully compared with the measured results.

  8. Dislocation density and Burgers vector population in fiber-textured Ni thin films determined by high-resolution X-ray line profile analysis

    DEFF Research Database (Denmark)

    Csiszár, Gábor; Pantleon, Karen; Alimadadi, Hossein

    2012-01-01

    Nanocrystalline Ni thin films have been produced by direct current electrodeposition with different additives and current density in order to obtain 〈100〉, 〈111〉 and 〈211〉 major fiber textures. The dislocation density, the Burgers vector population and the coherently scattering domain size distri...

  9. Crystallographic texture and microstructural changes in fusion welds of recrystallized Zry-4 rolled plates

    Science.gov (United States)

    Moya Riffo, A.; Vicente Alvarez, M. A.; Santisteban, J. R.; Vizcaino, P.; Limandri, S.; Daymond, M. R.; Kerr, D.; Okasinski, J.; Almer, J.; Vogel, S. C.

    2017-05-01

    This work presents a detailed characterization of the microstructural and crystallographic texture changes observed in the transition region in a weld between two Zircaloy-4 cold rolled and recrystallized plates. The microstructural study was performed by optical microscopy under polarized light and scanning electron microscopy (SEM). Texture changes were characterized at different lengthscales: in the micrometric size, orientation imaging maps (OIM) were constructed by electron backscatter diffraction (EBSD), in the millimetre scale, high energy XRD experiments were done at the Advanced Photon Source (USA) and compared to neutron diffraction texture determinations performed in the HIPPO instrument at Los Alamos National Laboratory. In the heat affected zone (HAZ) we observed the development of Widmanstätten microstructures, typical of the α(hcp) to β(bcc) phase transformation. Associated with these changes a rotation of the c-poles is found in the HAZ and fusion zone. While the base material shows the typical texture of a cold rolled plate, with their c-poles pointing 35° apart from the normal direction of the plate in the normal-transversal line, in the HAZ, c-poles align along the transversal direction of the plate and then re-orient along different directions, all of these changes occurring within a lengthscale in the order of mm. The evolution of texture in this narrow region was captured by both OIM and XRD, and is consistent with previous measurements done by Neutron Diffraction in the HIPPO diffractometer at Los Alamos National Laboratory, USA. The microstructural and texture changes along the HAZ were interpreted as arising due to the effect of differences in the cooling rate and β grain size on the progress of the different α variants during transformation. Fast cooling rates and large β grains are associated to weak variant selection during the β->α transformation, while slow cooling rates and fine β grains result in strong variant selection.

  10. Crystallographic texture and microstructural changes in fusion welds of recrystallized Zry-4 rolled plates

    Energy Technology Data Exchange (ETDEWEB)

    Riffo, A. Moya; Alvarez, M.A.Vicente; Santisteban, J R; Vizcaino, P; Limandri, S.; Daymond, M. R.; Kerr, D.; Vogel, S C; Almer, J.; Okasinski, J.

    2017-02-08

    This study presents a detailed characterization of the microstructural and crystallographic texture changes observed in the transition region in a weld between two Zircaloy-4 cold rolled and recrystallized plates. The microstructural study was performed by optical microscopy under polarized light and scanning electron microscopy (SEM). Texture changes were characterized at different lengthscales: in the micrometric size, orientation imaging maps (OIM) were constructed by electron backscatter diffraction (EBSD), in the millimetre scale, high energy XRD experiments were done at the Advanced Photon Source (USA) and compared to neutron diffraction texture determinations performed in the HIPPO instrument at Los Alamos National Laboratory. In the heat affected zone (HAZ) we observed the development of Widmanstätten microstructures, typical of the α(hcp) to β(bcc) phase transformation. Associated with these changes a rotation of the c-poles is found in the HAZ and fusion zone. While the base material shows the typical texture of a cold rolled plate, with their c-poles pointing 35° apart from the normal direction of the plate in the normal-transversal line, in the HAZ, c-poles align along the transversal direction of the plate and then re-orient along different directions, all of these changes occurring within a lengthscale in the order of mm. The evolution of texture in this narrow region was captured by both OIM and XRD, and is consistent with previous measurements done by Neutron Diffraction in the HIPPO diffractometer at Los Alamos National Laboratory, USA. The microstructural and texture changes along the HAZ were interpreted as arising due to the effect of differences in the cooling rate and β grain size on the progress of the different α variants during transformation. Fast cooling rates and large β grains are associated to weak variant selection during the β–>α transformation, while slow cooling rates and fine β grains result in strong

  11. Texturized pinto bean protein fortification in straight dough bread formulation

    Science.gov (United States)

    Pinto beans were milled and then air-classified to obtain a raw high protein fraction (RHPF) followed by extrusion to texturize the protein fraction. The texturized high protein fraction (THPF) was then milled to obtain flour, and combined with wheat flour at 5%, 10%, and 15% levels to make bread. A...

  12. High-precision Stellar Limb-darkening in Exoplanetary Transits

    Science.gov (United States)

    Morello, G.; Tsiaras, A.; Howarth, I. D.; Homeier, D.

    2017-09-01

    Characterization of the atmospheres of transiting exoplanets relies on accurate measurements of the extent of the optically thick area of the planet at multiple wavelengths with a precision ≲ 100 parts per million (ppm). Next-generation instruments onboard the James Webb Space Telescope (JWST) are expected to achieve ∼10 ppm precision for several tens of targets. A similar precision can be obtained in modeling only if other astrophysical effects, including the stellar limb-darkening, are properly accounted for. In this paper, we explore the limits on precision due to the mathematical formulas currently adopted to approximate the stellar limb-darkening, and due to the use of limb-darkening coefficients obtained either from stellar-atmosphere models or empirically. We recommend the use of a two-coefficient limb-darkening law, named “power-2,” which outperforms other two-coefficient laws adopted in the exoplanet literature in most cases, and particularly for cool stars. Empirical limb-darkening based on two-coefficient formulas can be significantly biased, even if the light-curve residuals are nearly photon-noise limited. We demonstrate an optimal strategy to fitting for the four-coefficient limb-darkening in the visible, using prior information on the exoplanet orbital parameters to break some of the degeneracies that otherwise would prevent the convergence of the fit. Infrared observations taken with the JWST will provide accurate measurements of the exoplanet orbital parameters with unprecedented precision, which can be used as priors to improve the stellar limb-darkening characterization, and therefore the inferred exoplanet parameters, from observations in the visible, such as those taken with Kepler/K2, the JWST, and other past and future instruments.

  13. Symmetrization driven spin transition in ɛ-FeOOH at high pressure

    Science.gov (United States)

    Gleason, A. E.; Quiroga, C. E.; Suzuki, A.; Pentcheva, R.; Mao, W. L.

    2013-10-01

    Structural and electronic spin transitions in high-pressure ε-FeOOH are studied using a combination of high pressure X-ray emission spectroscopy (XES), X-ray diffraction (XRD) and density functional theory (DFT) calculations. Using XES, a high- to low-spin transition in trivalent iron is found in ε-FeOOH on compression between 40 and 60 GPa. This is accompanied by a sudden discontinuity in unit cell volume at 53(±2) GPa, obtained from XRD data collected over the same compression range. These results are consistent with DFT calculations using an on-site Coulomb repulsion term (GGA+U), which predict a spin transition in ε-FeOOH at 64.8 GPa. A second order phase transition from P21nm to Pnnm is predicted from DFT at ∼43 GPa and evidenced in the XRD data from the anisotropic stiffening of the lattice parameters around the spin transition. In addition, the DFT results give evidence that the spin collapse is assisted by symmetrization of hydrogen bonds during the transition from P21nm to Pnnm. As the presence of hydrogen, even in small quantities, can affect phase relations, melting temperature, rheology, and other key properties of the Earth's mantle, our study unveils a connection between water (hydroxyl) content and the spin-transition pressure of Fe3+ in the Earth's mantle.

  14. Phase transition and high pressure behavior of Zirconium and Niobium carbides

    Science.gov (United States)

    Singh, Archana; Aynyas, Mahendra; Sanyal, Sankar

    2009-03-01

    We have predicted the phase transition pressure (PT)and high pressure behavior of Zirconium and Niobium carbide (ZrC, NbC). The high pressure structural phase transitions in ZrC and NbC has been studied by using a two body inter-ionic potential model, which includes the Coulomb screening effect, due to the semi-metallic nature of these compounds. These transition metal carbides have been found to undergo NaCl (B1) to CsCl (B2)-type structural phase transition, at high pressure like other binary systems. We predict such structural transformation in ZrC and NbC at a pressure of 98GPa and 85GPa respectively. We have also predicted second order elastic constant and bulk modulus. The present theoretical work has been compared with the corresponding experimental data and prediction of LAPW and GGA and LDA theories.

  15. Transition radiation at radio frequencies from ultra-high energy neutrino-induced showers

    CERN Document Server

    Motloch, Pavel; Privitera, Paolo; Zas, Enrique

    2015-01-01

    Coherent radiation at radio frequencies from high-energy showers fully contained in a dense radio-transparent medium - like ice, salt or regolith - has been extensively investigated as a promising technique to search for ultra-high energy (UHE) neutrinos. Additional emission in the form of transition radiation may occur when a neutrino-induced shower produced close to the Earth surface emerges from the ground into atmospheric air. We present the first detailed evaluation of transition radiation from high-energy showers crossing the boundary between two different media. We found that transition radiation is sizable over a wide solid angle and coherent up to $\\sim$ 1 GHz. These properties encourage further work to evaluate the potential of a large-aperture UHE neutrino experiment based on detection of transition radiation.

  16. Gabor transform in texture analysis

    Science.gov (United States)

    Chen, Chien-Chang; Chen, Chaur-Chin

    1994-10-01

    Gabor transform has recently been exploited to do texture analysis, including texture edge detection, texture segmentation/discrimination, and texture synthesis. For most of the applications using Gabor transform, people convolve the given texture image with a set of Gabor filters with some user specified parameters. Although the mathematical formulation of applications involve the Fourier transform, few have investigated mathematical properties of the relationship between Gabor filters and their Fourier transform. This paper mainly studies mathematical properties of real Gabor filters and their corresponding Fourier transform. The goal is to select a set of `interesting' Gabor filters, or say, a set of parameters for Gabor filters to do texture analysis. We demonstrate, by means of 3-D graphical displays, that a Gabor filter or its corresponding Fourier transform may have a single peak or double peaks according to different parameters. Experiments for texture discrimination are given to demonstrate the applications of Gabor transform.

  17. Numerical analysis of monocrystalline silicon solar cells with fine nanoimprinted textured surface

    Science.gov (United States)

    Yoshinaga, Seiya; Ishikawa, Yasuaki; Araki, Shinji; Honda, Tatsuki; Jiang, Yunjiang; Uraoka, Yukiharu

    2017-02-01

    We investigated the surface reflectance of nanoimprinted textures on silicon. Zirconium oxide, which is a wide-bandgap inorganic dielectric material, was used as the texturing material. We performed several calculations to optimize the textures for the production of high-efficiency bulk-type monocrystalline silicon solar cells. Our analysis revealed that nanoimprinted textured solar cells exhibit a lower reverse saturation current density than a solar cell with a conventional etched texture. It was also confirmed that the photocarrier generation rate for a solar cell with a submicron-scale nanoimprinted texture has little dependence on the texture shape. Furthermore, the weighted average reflectance of an optimized nanoimprinted textured solar cell was substantially reduced to 3.72%, suggesting that texture formation by nanoimprint lithography is an extremely effective technology for producing high-efficiency solar cells at a low cost.

  18. Spatial Arrangement in Texture Discrimination and Texture Segregation

    Directory of Open Access Journals (Sweden)

    Kathleen Vancleef

    2013-02-01

    Full Text Available We investigated the role of spatial arrangement of texture elements in three psychophysical experiments on texture discrimination and texture segregation. In our stimuli, oriented Gabor elements formed an iso-oriented and a randomly oriented texture region. We manipulated (1 the orientation similarity in the iso-oriented region by adding orientation jitter to the orientation of each Gabor; (2 the spatial arrangement of the Gabors: quasi-random or regular; and (3 the shape of the edge between the two texture regions: straight or curved. In Experiment 1, participants discriminated an iso-oriented stimulus from a stimulus with only randomly oriented elements. Experiment 2 required texture segregation to judge the shape of the texture edge. Experiment 3 replicated Experiment 2 with Gabors of a smaller spatial extent in a denser arrangement. We found comparable performance levels with regular and quasi-random Gabor positions in the discrimination task but not in the segregation tasks. We conclude that spatial arrangement plays a role in a texture segregation task requiring shape discrimination of the texture edge but not in a texture discrimination task in which it is sufficient to discriminate an iso-oriented region from a completely random region.

  19. Model investigation of non-thermal phase transition in high energy collisions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The non-thermal phase transition in high energy collisions is studied in detail in the framework of random cascade model. The relation between the characteristic parameter λq of phase transition and the rank q of moment is obtained using Monte Carlo simulation, and the existence of two phases in self-similar cascading multiparticle systems is shown. The relation between the critical point qc of phase transition on the fluctuation parameter α is obtained and compared with the experimental results from NA22. The same study is carried out also by analytical calculation under central limit approximation. The range of validity of the central limit approximation is discussed.

  20. Phase transition and elastic properties of zinc sulfide under high pressure from first principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Wei [Hubei Univ. of Education, Wuhan (China). Dept. of Physics and Electronics; Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Fluid Physics; Song, Jin-Fan; Wang, Ping; Lu, Cheng; Lu, Zhi-Wen [Nanyang Normal Univ. (China). Dept. of Physics; Tan, Xiao-Ming [Ludong Univ., Yantai (China). Dept. of Physics

    2011-10-15

    A theoretical investigation on structural and elastic properties of zinc sulfide semiconductor under high pressure is performed by employing the first-principles method based on the density functional theory. The calculated results show that the transition pressure P{sub t} for the structural phase transition from the B3 structure to the B1 structure is 17.04 GPa. The calculated values are generally speaking in good agreement with experiments and with similar theoretical calculations. (orig.)

  1. Combining multiple features for color texture classification

    Science.gov (United States)

    Cusano, Claudio; Napoletano, Paolo; Schettini, Raimondo

    2016-11-01

    The analysis of color and texture has a long history in image analysis and computer vision. These two properties are often considered as independent, even though they are strongly related in images of natural objects and materials. Correlation between color and texture information is especially relevant in the case of variable illumination, a condition that has a crucial impact on the effectiveness of most visual descriptors. We propose an ensemble of hand-crafted image descriptors designed to capture different aspects of color textures. We show that the use of these descriptors in a multiple classifiers framework makes it possible to achieve a very high classification accuracy in classifying texture images acquired under different lighting conditions. A powerful alternative to hand-crafted descriptors is represented by features obtained with deep learning methods. We also show how the proposed combining strategy hand-crafted and convolutional neural networks features can be used together to further improve the classification accuracy. Experimental results on a food database (raw food texture) demonstrate the effectiveness of the proposed strategy.

  2. Refining Parameters of the XO-5 Planetary System with High-Precision Transit Photometry

    CERN Document Server

    Maciejewski, G; Adam, Ch; Raetz, St; Neuhaeuser, R

    2011-01-01

    Studies of transiting extrasolar planets offer an unique opportunity to get to know the internal structure of those worlds. The transiting exoplanet XO-5 b was found to have an anomalously high Safronov number and surface gravity. Our aim was to refine parameters of this intriguing system and search for signs of transit timing variations. We gathered high-precision light curves of two transits of XO-5 b. Assuming three different limb darkening laws, we found the best-fitting model and redetermined parameters of the system, including planet-to-star radius ratio, impact parameter and central time of transits. Error estimates were derived by the prayer bead method and Monte Carlo simulations. Although system's parameters obtained by us were found to agree with previous studies within one sigma, the planet was found to be notable smaller with the radius of 1.03+0.06-0.05 Jupiter radii. Our results confirm the high Safronov number and surface gravity of the planet. With two new mid-transit times, the ephemeris was...

  3. Microcrystalline Silicon Films and Solar Cells Prepared by Photochemical Vapor Deposition on Textured SnO2 with High Haze Factors

    Science.gov (United States)

    Zhao, Ying; Miyajima, Shinsuke; Ide, Yoshinori; Yamada, Akira; Konagai, Makoto

    2002-11-01

    Microcrystalline silicon (μc-Si) films and solar cells were prepared by mercury-sensitized photochemical vapor deposition (photo-CVD). The changes in the structural properties of a series of μc-Si films grown under various H2 dilution and deposition pressure conditions were discussed. The results indicated that the properties of μc-Si films depend strongly on the atomic hydrogen. The microstructures of μc-Si films on textured SnO2 with different haze factors (from 13% to 65%) were observed with a scanning electron microscope and a transmission electron microscope. The observations revealed that the μc-Si layers grew from the initial stage of deposition with columnar grains and that they were conformal to the surface of textured SnO2. The grain boundary density of μc-Si film on SnO2 with higher haze factors was lower than that on SnO2 with lower haze factors. The effect of textured SnO2 with different haze ratios on p-i-n μc-Si cell characteristics was discussed and it was found that the higher haze factors showed a higher degree of light trapping in our μc-Si cells. We deposited μc-Si cells with an intrinsic μc-Si layer thickness of 430 nm on a textured SnO2 sample with a haze factor of 42% and achieved a conversion efficiency of 6.55%.

  4. [Visual Texture Agnosia in Humans].

    Science.gov (United States)

    Suzuki, Kyoko

    2015-06-01

    Visual object recognition requires the processing of both geometric and surface properties. Patients with occipital lesions may have visual agnosia, which is impairment in the recognition and identification of visually presented objects primarily through their geometric features. An analogous condition involving the failure to recognize an object by its texture may exist, which can be called visual texture agnosia. Here we present two cases with visual texture agnosia. Case 1 had left homonymous hemianopia and right upper quadrantanopia, along with achromatopsia, prosopagnosia, and texture agnosia, because of damage to his left ventromedial occipitotemporal cortex and right lateral occipito-temporo-parietal cortex due to multiple cerebral embolisms. Although he showed difficulty matching and naming textures of real materials, he could readily name visually presented objects by their contours. Case 2 had right lower quadrantanopia, along with impairment in stereopsis and recognition of texture in 2D images, because of subcortical hemorrhage in the left occipitotemporal region. He failed to recognize shapes based on texture information, whereas shape recognition based on contours was well preserved. Our findings, along with those of three reported cases with texture agnosia, indicate that there are separate channels for processing texture, color, and geometric features, and that the regions around the left collateral sulcus are crucial for texture processing.

  5. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  6. High Energy Rate Forming Induced Phase Transition in Austenitic Steel

    Science.gov (United States)

    Kovacs, T.; Kuzsella, L.

    2017-02-01

    In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea means indirect hardening setup. Austenitic stainless steels have high plasticity and can be cold formed easily. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness [1]. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

  7. Directional Filters for Cartoon + Texture Image Decomposition

    Directory of Open Access Journals (Sweden)

    Antoni Buades

    2016-05-01

    Full Text Available We present in this article a detailed analysis and implementation of the cartoon+texture decomposition algorithm proposed in [A. Buades, J.L. Lisani, 'Directional filters for color cartoon + texture image and video decomposition', Journal of Mathematical Imaging and Vision, 2015]. This method follows the approach proposed by [A. Buades, T. Le, J-M. Morel, L. Vese, 'Cartoon+Texture Image Decomposition', IPOL 2011], based on low/high-pass filtering, but replaces the isotropic filters by a bank of low-pass directional filters. The cartoon image is obtained by filtering in the direction that leads to the largest local total variation rate reduction. This permits to improve the performance of the decomposition near image discontinuities, where an halo effect was produced by the previous method.

  8. Texture synthesis via the matching compatibility between patches

    Institute of Scientific and Technical Information of China (English)

    WANG WenCheng; LIU FeiTong; HUANG PeiJie; WU EnHua

    2009-01-01

    A new patch-based texture synthesis method is presented in this paper.By the method,a set of patches that can be matched with a sampled patch for growing textures effectively,called the matching compatibility between patches,is generated first for each patch,and the set is further optimized by culling the patches that may cause synthesis conflicts.In this way,similarity measurement calculation for selecting suitable patches in texture synthesis can be greatly saved,and synthesis conflicts between neighbouring patches are substantially reduced.Furthermore,retrace computation is Integrated in the synthesis process to improve the texture quality.As a result,the new method can produce high quality textures as texture optimization,the best method to date for producing good textures,and run in a time complexity linear to the size of the output texture.Experimental results show that the new method can interactively generate a large texture in 1024 × 1024 pixels,which is very difficult to achieve by existing methods.

  9. Effect of stellar activity on the high precision transit light curve

    Directory of Open Access Journals (Sweden)

    Oshagh, M.

    2015-01-01

    Full Text Available Stellar activity features such as spots and plages can create difficulties in determining planetary parameters through spectroscopic and photometric observations. The overlap of a transiting planet and a stellar spot, for instance, can produce anomalies in the transit light curve that may lead to inaccurate estimation of the transit duration, depth, and timing. Such inaccuracies can affect the precise derivation of the planet’s radius. In this talk we will present the results of a quantitative study on the effects of stellar spots on high precision transit light curves. We show that spot anomalies can lead to the estimate of a planet radius that is 4% smaller than the real value. The effects on the transit duration can also be of the order of 4%, longer or shorter. Depending on the size and distribution of spots, anomalies can also produce transit timing variations with significant amplitudes. For instance, TTVs with signal amplitudes of 200 seconds can be produced by spots as large as the largest sunspot. Finally, we examine the impact of active regions on the transit depth measurements in different wavelengths, in order to probe the impact of this effect on transmission spectroscopy measurements. We show that significant (up to 10% underestimation/overestimation of the planet-to-star radius ratio can be measured, especially in the short wavelength regime.

  10. Development of a Transition Process Scale for High-risk Infant’s Caregiver

    Directory of Open Access Journals (Sweden)

    Mi YU

    2016-02-01

    Full Text Available Background: Transition into parenthood is a major developmental life event and is very significant because development in infanthood is affected by the transition process of mothers parenting an infant. This study aimed to develop the assessment tool for transition process of high risk infant’s caregiver in Korea.Methods: The participants were 246 mothers of premature infant born with gestational age (< 37 weeks or low birth weight (< 2500 gm, of less than 24 months of age. Preliminary items were derived from transition process scale for parent of children with autism. Factor analysis was performed to test construct validity of the scale, the correlation between transition processes and parenting efficacy was used for testing predictive validity.Results: The final scale was composed of 23 items divided into 5 factors: wandering (7 items, devotion (5 items, acceptance (4 items, denial (4 items, frustration (3 items. The total variance for validity described by the 5 factors was 60.8% and the reliability of the scale was total Cronbach’s α 0.90 and wandering 0.85, devotion 0.78, acceptance 0.72, denial 0.72, and frustration 0.71. Correlation between transition process and parenting efficacy was statistically significant; wandering(r=-0.61, P <.001, devotion (r=-0.60, P<.001, acceptance (r=0.30, P <.001, denial (r=-0.31, P <.001 and frustration (r= -0.27, P <.001.Conclusion: This final assessment scale will be used to investigate high-risk infant caregiver’s transition process and provide basic data for program development to provide differentiated support and care at each process. Keywords: Caregiver, High risk, Infant, Scale, Transition

  11. A Texture Analysis of 3D Radar Images

    NARCIS (Netherlands)

    Deiana, D.; Yarovoy, A.

    2009-01-01

    In this paper a texture feature coding method to be applied to high-resolution 3D radar images in order to improve target detection is developed. An automatic method for image segmentation based on texture features is proposed. The method has been able to automatically detect weak targets which fail

  12. The magic of four zero neutrino Yukawa textures

    CERN Document Server

    Roy, Probir

    2010-01-01

    Four is the maximum number of texture zeros allowed in the Yukawa coupling matrix of three massive neutrinos. These completely fix the high scale CP violation needed for leptogenesis in terms of that accessible at laboratory energies. $\\mu\\tau$ symmetry drastically reduces such allowed textures. Only one form of the light neutrinos mass matrix survives comfortably while another is marginally allowed.

  13. Parental involvement protects against self-medication behaviors during the high school transition.

    Science.gov (United States)

    Gottfredson, Nisha C; Hussong, Andrea M

    2011-12-01

    We examined how drinking patterns change as adolescents transition to high school, particularly as a function of parental involvement. Stress associated with the transition to high school may deplete psychological resources for coping with negative daily emotions in an environment when opportunities to drink are more common. A cohort of elevated-risk middle school students completed daily negative affect (sadness, worry, anger, and stress) and alcohol use assessments before and after the transition to high school, resulting in a measurement burst design. Adolescents who reported less parental involvement were at higher risk for drinking on any given day. After (but not before) the transition to high school, daily within-person fluctuations of sadness predicted an increased probability of same-day alcohol use for adolescents who reported that their parents were minimally involved in their lives. The other negative affect indicators were not predictive of use. Our results suggest that the transition to high school may represent an important intervention leverage point, particularly for adolescents who lack adequate parental support to help them cope with day-to-day changes in sadness.

  14. Melt textured YBaCuO transport current capability. Application to current limitation; Capacite de transport et de limitation du courant des materiaux YBaCuO textures

    Energy Technology Data Exchange (ETDEWEB)

    Porcar, L.; Belmont, O.; Noudem, J.G.; Barbut, J.M.; Barrault, M. [Schneider Electric S.A., Grenoble (France); Bourgault, D.; Chaud, X.; Tournier, R. [CNRS-EPM/Matformag, Grenoble (France); Tixador, P. [CNRS-CRTBT/LEG, Grenoble (France)

    1998-01-01

    Pulsed and permanent sinusoidal transport current have been applied to melt textured Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} in order to estimate its current limitation capability. High pulsed transport currents reaching 9000A (23000 A/cm{sup 2}) crossed a 4 cm long sample. In permanent sinusoidal current, 3000 A (7800 A/cm{sup 2}) crossed the sample without showing any resistive losses. Above the critical current, the transition from the superconducting to the normal state is strongly abrupt. (orig.). 8 refs.

  15. Effect of moisture content on textural attributes of dried figs

    Science.gov (United States)

    Ansari, Sara; Maftoon-Azad, Neda; Farahnaky, Asgar; Hosseini, Ebrahim; Badii, Fojan

    2014-10-01

    Due to their soft texture consumers prefer moist figs, which has motivated fig processors to increase the production of this product. However, as water enhances the browning reaction rate, moisture content optimisation of moist figs is very important. Processed figs must have suitable texture softness with browning kept to a minimum. The purpose of this study was to examine the effect of moisture content on the textural attributes of dried figs. Hardness, compression energy, gradient, gumminess and chewiness of fig samples decreased with moisture content exponentially, whereas the trend of springiness and cohesiveness with change of moisture content was nearly constant. Moreover, in the texture profile analysis plot of rehydrated figs, the presence of negative area is an indication of adhesiveness which was zero in control dried figs. The results of the texture profile analysis tests proved the existence of a critical moisture content of about 18.4%, above which no significant effect of moisture content on textural parameters was found. The glass-rubber transition results from differential scanning calorimeter may explain the different texture profile analysis attributes of dried figs compared with rehydrated figs.

  16. High pressure structural phase transitions of TiO2 nanomaterials

    Science.gov (United States)

    Quan-Jun, Li; Bing-Bing, Liu

    2016-07-01

    Recently, the high pressure study on the TiO2 nanomaterials has attracted considerable attention due to the typical crystal structure and the fascinating properties of TiO2 with nanoscale sizes. In this paper, we briefly review the recent progress in the high pressure phase transitions of TiO2 nanomaterials. We discuss the size effects and morphology effects on the high pressure phase transitions of TiO2 nanomaterials with different particle sizes, morphologies, and microstructures. Several typical pressure-induced structural phase transitions in TiO2 nanomaterials are presented, including size-dependent phase transition selectivity in nanoparticles, morphology-tuned phase transition in nanowires, nanosheets, and nanoporous materials, and pressure-induced amorphization (PIA) and polyamorphism in ultrafine nanoparticles and TiO2-B nanoribbons. Various TiO2 nanostructural materials with high pressure structures are prepared successfully by high pressure treatment of the corresponding crystal nanomaterials, such as amorphous TiO2 nanoribbons, α-PbO2-type TiO2 nanowires, nanosheets, and nanoporous materials. These studies suggest that the high pressure phase transitions of TiO2 nanomaterials depend on the nanosize, morphology, interface energy, and microstructure. The diversity of high pressure behaviors of TiO2 nanomaterials provides a new insight into the properties of nanomaterials, and paves a way for preparing new nanomaterials with novel high pressure structures and properties for various applications. Project supported by the National Basic Research Program of China (Grant No. 2011CB808200), the National Natural Science Foundation of China (Grant Nos. 11374120, 11004075, 10979001, 51025206, 51032001, and 21073071), and the Cheung Kong Scholars Programme of China.

  17. Computational study of textured ferroelectric polycrystals: Texture development during templated grain growth

    Science.gov (United States)

    Zhou, Jie E.; Yan, Yongke; Priya, Shashank; Wang, Yu U.

    2017-02-01

    Quantitative relationships between processing, microstructure, and properties in textured ferroelectric polycrystals and the underlying responsible mechanisms are investigated by phase field modeling and computer simulation. This study focuses on three important aspects of textured ferroelectric ceramics: (i) grain microstructure evolution during templated grain growth processing, (ii) crystallographic texture development as a function of volume fraction and seed size of the templates, and (iii) dielectric and piezoelectric properties of the obtained template-matrix composites of textured polycrystals. Findings on the first two aspects are presented here, while an accompanying paper of this work reports findings on the third aspect. In this paper, grain microstructure evolution in the polycrystalline matrix with different template volume fractions and seed sizes is simulated. To quantitatively characterize the crystallographic texture development during templated grain growth processing, a numerical algorithm is developed to compute the diffraction peak intensities and Lotgering factor of the simulated polycrystals during grain microstructure evolution. This novel approach provides a direct link between phase field simulation and diffraction experiment. This computational study clarifies the effects of the template volume fraction and template seed size on the final grain microstructure and texture. It is found that, while the degree of crystallographic texture generally increases with increasing template volume fraction, it is the average distance between template seeds that plays an important role. This finding suggests that reducing the template seed size and shortening the seed distance is an effective way to achieve higher texture at a lower template volume fraction, which is highly desired for enhancing the piezoelectric properties of ferroelectric polycrystals. The computational results are compared with complementary experiments, where good agreement is

  18. Texture Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Stegmann, Mikkel Bille; Darkner, Sune;

    2007-01-01

    to excessive storage and computational requirements. We propose to reduce the dimensionality of the textural components by selecting a subset of basis functions from a larger dictionary, estimate regression splines and model only the coeffcients of the retained basis functions. We demonstrate the use of two...... types of bases, namely wavelets and wedgelets. Theformer extends the previous work of Wolstenholme and Taylor where Haar wavelet coeffcients subsets were applied. The latter introduces the wedgelet regression tree based on triangulated domains. The wavelet and wedgelet regression splines are functional...

  19. The effect of substrate texture and oxidation temperature on oxide texture development in zirconium alloys

    Science.gov (United States)

    Garner, A.; Frankel, P.; Partezana, J.; Preuss, M.

    2017-02-01

    During corrosion of zirconium alloys a highly textured oxide is formed, the degree of this preferred orientation has previously been shown to be an important factor in determining the corrosion behaviour of these alloys. Two distinct experiments were designed in order to investigate the origin of this oxide texture development on two commercial alloys. Firstly, sheet samples of Zircaloy-4 were oxidised between 500 and 800 °C in air. The resulting monoclinic oxide texture strength was observed to decrease with increasing oxidation temperature. In a second experiment, orthogonal faces of Low Tin ZIRLO™ were oxidised in 360 °C water, providing different substrate textures but identical microstructures. The substrate texture was observed to have a negligible effect on the corrosion performance whilst the major orientation of both oxide phases was found to be independent of substrate orientation. It is concluded that the main driving force for oxide texture development in single-phase zirconium alloys is the compressive stress caused by the Zrsbnd ZrO2 transformation.

  20. The Experience of Transitioning Two Adolescents with Asperger Syndrome in Academically Focused High Schools

    Science.gov (United States)

    Dixon, Roselyn M.; Tanner, Kathleen

    2013-01-01

    Adolescents with Asperger syndrome (AS) are increasingly being placed in academically focused high schools. These students, although academically able, may not be coping with the wider classroom and social demands of transition to, and within, the high school environment. Schools are keen to enroll these students. However, there appears to be a…

  1. Transition to College and Students with High Functioning Autism Spectrum Disorder: Strategy Considerations for School Counselors

    Science.gov (United States)

    Dipeolu, Abiola O.; Storlie, Cassandra; Johnson, Carol

    2014-01-01

    There are limited school counseling resources that address the unique post high school transition issues faced by students with High-functioning Autism Spectrum Disorder (HASD). While many school counselors have excellent skills in assessment, advising, and career planning, it is worthwhile to expand these to include working with students with…

  2. College Student for a Day: A Transition Program for High School Students with Disabilities

    Science.gov (United States)

    Novakovic, Alexandra; Ross, Denise E.

    2015-01-01

    High school students with disabilities can benefit from early exposure to campus-based accommodations and supports as they transition to college. College Student for a Day (CSFAD) is an on-campus activity-based program that introduces high school students with disabilities to supports and accommodations on a college campus. This Practice Brief…

  3. Phase transition and superconductivity of SrFe2As2 under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Uhoya, Walter [University of Alabama, Birmingham; Montgomery, Jeffrey M [University of Alabama, Birmingham; Tsoi, Georgiy [University of Alabama, Birmingham; Vohra, Yogesh [University of Alabama, Birmingham; McGuire, Michael A [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Sales, Brian C [ORNL; Weir, S. T. [Lawrence Livermore National Laboratory (LLNL)

    2011-01-01

    High pressure x-ray diffraction and electrical resistance measurements have been carried out on SrFe{sub 2}As{sub 2} to a pressure of 23 GPa and temperature of 10 K using a synchrotron source and designer diamond anvils. At ambient temperature, a phase transition from the tetragonal phase to a collapsed tetragonal (CT) phase is observed at 10 GPa under non-hydrostatic conditions. The experimental relation that T-CT transition pressure for 122 Fe-based superconductors is dependent on ambient pressure volume is affirmed. The superconducting transition temperature is observed at 32 K at 1.3 GPa and decreases rapidly with a further increase of pressure in the region where the T-CT transition occurs. Our results suggest that T{sub C} falls below 10 K in the pressure range of 10-18 GPa where the CT phase is expected to be stable.

  4. Quantitative texture analysis of electrodeposited line patterns

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A.J.

    2005-01-01

    Free-standing line patterns of Cu and Ni were manufactured by electrochemical deposition into lithographically prepared patterns. Electrodeposition was carried out on top of a highly oriented Au-layer physically vapor deposited on glass. Quantitative texture analysis carried out by means of x...

  5. Quantitative texture analysis of electrodeposited line patterns

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A.J.

    2005-01-01

    Free-standing line patterns of Cu and Ni were manufactured by electrochemical deposition into lithographically prepared patterns. Electrodeposition was carried out on top of a highly oriented Au-layer physically vapor deposited on glass. Quantitative texture analysis carried out by means of x...

  6. Exoplanet transits enable high-resolution spectroscopy across spatially resolved stellar surfaces

    CERN Document Server

    Dravins, Dainis; Dahlén, Erik; Pazira, Hiva

    2016-01-01

    Observations of stellar surfaces - except for the Sun - are hampered by their tiny angular extent, while observed spectral lines are smeared by averaging over the stellar surface, and by stellar rotation. Exoplanet transits can be used to analyze stellar atmospheric structure, yielding high-resolution spectra across spatially highly resolved stellar surfaces, free from effects of spatial smearing and the rotational wavelength broadening present in full-disk spectra. During a transit, stellar surface portions successively become hidden, and differential spectroscopy between various transit phases provides spectra of those surface segments then hidden behind the planet. The small area subtended by even a large planet (about 1% of a main-sequence star) offers high spatial resolution but demands very precise observations. We demonstrate the reconstruction of photospheric FeI line profiles at a spectral resolution R=80,000 across the surface of the solar-type star HD209458. Any detailed understanding of stellar at...

  7. Features improvement techniques supply of highly skilled bodybuilders in transition training

    Directory of Open Access Journals (Sweden)

    Oleksandr Aghyppo

    2015-03-01

    Full Text Available Purpose of this paper is to improve the supply of highly skilled technique bodybuilders training in a transition period with the restoration of lean body mass and functional state of an athlete after a competitive activity. Material and Method: the study involved 18 highly skilled bodybuilders are included in the team of the Kharkiv region of Ukraine and bodybuilding. Results: a comparative characteristic of the conventional technique that is often used in the training process in bodybuilding. Developed and justified the optimal technique for highly skilled bodybuilders, depending on the initial form of the athlete at the beginning of the transition period of training. Conclusions: on the basis of the study the author suggests best practices in supply depending on the microcycle training in transition training.

  8. Structural and magnetic phase transitions in NdCoAsO under high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Uhoya, Walter; Tsoi, Georgiy M.; Vohra, Yogesh K.; McGuire, Michael A.; Sefat, Athena S.; Sales, Brian C.; Mandrus, David; Weir, Samuel T. (UAB); (ORNL); (LLNL)

    2010-05-04

    We have investigated structural and magnetic phase transitions under high pressures in a quaternary rare-earth transition-metal arsenide oxide NdCoAsO compound that is isostructural to the high temperature superconductor parent phase NdFeAsO. The four-probe electrical resistance measurements carried out in a designer diamond anvil cell show that the ferromagnetic Curie temperature and antiferromagnetic Neel temperature increase with an increase in pressure. High pressure x-ray diffraction studies using a synchrotron source show a structural phase transition from a tetragonal phase to a new crystallographic phase at a pressure of 23 GPa at 300 K. The NdCoAsO sample remained antiferromagnetic and non-superconducting down to 10 K and up to the highest pressure achieved in this experiment, 53 GPa. A P-T phase diagram for NdCoAsO is presented from ambient conditions to P = 53 GPa and T = 10 K.

  9. Structural and magnetic phase transitions in NdCoAsO under high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Uhoya, Walter [University of Alabama, Birmingham; Tsoi, Georgiy [University of Alabama, Birmingham; Vohra, Y. K. [University of Alabama, Birmingham; McGuire, Michael A [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Sales, Brian C [ORNL; Mandrus, David [ORNL; Weir, S. T. [Lawrence Livermore National Laboratory (LLNL)

    2010-01-01

    We have investigated structural and magnetic phase transitions under high pressures in a quaternary rare-earth transition-metal arsenide oxide NdCoAsO compound that is isostructural to the high temperature superconductor parent phase NdFeAsO. The four-probe electrical resistance measurements carried out in a designer diamond anvil cell show that the ferromagnetic Curie temperature and antiferromagnetic Neel temperature increase with an increase in pressure. High pressure x-ray diffraction studies using a synchrotron source show a structural phase transition from a tetragonal phase to a new crystallographic phase at a pressure of 23 GPa at 300 K. The NdCoAsO sample remained antiferromagnetic and non-superconducting down to 10 K and up to the highest pressure achieved in this experiment, 53 GPa. A P-T phase diagram for NdCoAsO is presented from ambient conditions to P = 53 GPa and T = 10 K.

  10. 热等静压法制备高立方织构的镍基合金复合基带%Fabrication of Ni-based alloy composite substrate with high cube texture using hot isostatic presses method

    Institute of Scientific and Technical Information of China (English)

    邱火勤; 索红莉; 寇生中; 马麟; 田辉; 刘敏; 袁冬梅; 王营霞

    2011-01-01

    采用热等静压(HIP)法制备芯层为Ni-12%W(Ni12W,摩尔分数)合金、外层为Ni-5%W(Ni5W,摩尔分数)合金的Ni5W/Ni12W/Ni5W 3层复合初始坯锭:采用压延辅助双轴织构技术(RABiTSTM)通过直接冷轧及再结晶退火获得Ni5W/Ni12W/NiSW复合基带;采用X射线四环衍射技术(XRD)及背散射电子衍射技术(EBSD)对复合基带表面冷轧及再结晶织构进行分析.结果表明:冷轧复合基带表面形成较强的铜型形变织构,再结晶退火后复合基带表面形成锐利的立方织构,其立方织构含量达到99.1%(≤10°),与商业用Ni5W合金基带水平相当.%A tri-layer composite alloy ingot was fabricated by hot isostatic presses (HIP) method, in which the outer layer is Ni-5%W(Ni5W, mole fraction) alloy and the inner layer is Ni-12%W(Ni12W, mole fraction) alloy. The composite ingot was cold-rolled using the process of rolling assisted biaxially textured substrate (RABiTS?) technology and annealed to obtain the Ni5W/Ni12W/Ni5W composite substrate with high cube texture. The cold rolling and the recrystallization textures on the surface of the as-obtained composite substrate were studied systematically by X-ray and EBSD measurements. The results show that a strong deformation copper-type texture is obtained in the cold rolled composite substrate, and a sharp cube texture is formed on the surface of Ni5W/Ni12W/Ni5W composite substrate after a recrystallization annealing process. The percentage of the cube orientated grain within a misorientation angle of 10° is as high as 99.1%, which is in the same level as that of the commercial Ni5W tape.

  11. Optical transitions in highly charged californium ions with high sensitivity to variation of the fine-structure constant.

    Science.gov (United States)

    Berengut, J C; Dzuba, V A; Flambaum, V V; Ong, A

    2012-08-17

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf(16+) is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf(16+) has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters.

  12. Texture development in Galfenol wire

    Science.gov (United States)

    Boesenberg, A. J.; Restorff, J. B.; Wun-Fogle, M.; Sailsbury, H.; Summers, E.

    2013-05-01

    Galfenol (Fe-Ga alloy) wire fabrication provides a low cost alternative to directional solidification methods. This work evaluates the compositional dependence of the wire drawing suitability of Fe-Ga and characterizes the microstructural and magnetic properties of these wires. Wire has been produced with Ga contents between 10 at. % and 17 at. % to allow determination of the ductile to brittle transition (DTBT) in wire manufacture. Published results on chill cast bend specimens indicated that a DTBT occurs at roughly 15 at. % Ga. This DTBT was observed under tensile loading with a corresponding change in fracture behavior from transverse fracture to intergranular fracture. For improved magnetostrictive performance, higher Ga contents are desired, closer to the 17 at. % Ga evaluated in this work. Electron backscattered diffraction B-H loop and resonance measurements as a function of magnetic field (to determine modulus and coupling factor) are presented for as-drawn, furnace, and direct current (DC) annealed wire. Galfenol wire produced via traditional drawing methods is found to have a strong (α) texture parallel to the drawing direction. As-drawn wire was observed to have a lower magnetic permeability and larger hysteresis than DC annealed wire. This is attributed to the presence of a large volume of crystalline defects; such as vacancies and dislocations.

  13. Height and Tilt Geometric Texture

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

    2009-01-01

    We propose a new intrinsic representation of geometric texture over triangle meshes. Our approach extends the conventional height field texture representation by incorporating displacements in the tangential plane in the form of a normal tilt. This texture representation offers a good practical...... compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

  14. Measurements in Transitional Boundary Layers Under High Free-Stream Turbulence and Strong Acceleration Conditions.

    Science.gov (United States)

    Volino, Ralph John

    1995-01-01

    Measurements from transitional, heated boundary layers along a concave-curved test wall are presented and discussed. A boundary layer subject to low free-stream turbulence intensity (FSTI), which contains stationary streamwise (Gortler) vortices, is documented. The low FSTI measurements are followed by measurements in boundary layers subject to high (initially 8%) free-stream turbulence intensity and moderate to strong (K = {nuover U_sp{infty} {2}}{dUinftyover dx} as high as 9times 10^{ -6}) acceleration. The high FSTI experiments are the main focus of the work. Conditions were chosen to simulate those present on the downstream half of the pressure side of a gas turbine airfoil. The high FSTI boundary layers undergo transition from a strongly disturbed non-turbulent state to a fully-turbulent state. Due to the stabilizing effect of strong acceleration, the transition zones are of extended length in spite of the high FSTI. Transitional values of skin friction coefficients and Stanton numbers drop below flat-plate, low FSTI, turbulent flow correlations, but remain well above laminar flow values. Mean velocity and temperature profiles exhibit clear changes in shape as the flow passes through transition. Turbulence statistics, including the turbulent shear stress, turbulent heat flux, and turbulent Prandtl number, are documented. Turbulent transport is strongly suppressed below values in unaccelerated turbulent boundary layers. A technique called "octant analysis" is introduced and applied to several cases from the literature as well as to data from the present study. Octant analysis shows a fundamental difference between transitional and fully-turbulent boundary layers. Transitional boundary layers are characterized by incomplete mixing compared to fully-turbulent boundary layers. Similar octant analysis results are observed in both low and high FSTI cases. Spectral analysis suggests that the non-turbulent zone of the high FSTI flow is dominated by large scale

  15. Regrouping: organized activity involvement and social adjustment across the transition to high school.

    Science.gov (United States)

    Bohnert, Amy M; Aikins, Julie Wargo; Arola, Nicole T

    2013-01-01

    Although organized activities (OAs) have been established as important contexts of development, limited work has examined the role of OAs across the high school transition in buffering adolescents' social adjustment by providing opportunities for visibility and peer affiliation. The transition to high school is characterized by numerous changes and OAs may provide an important setting for establishing and maintaining peer relationships during this tumultuous time. This study included 151 8th grade U.S. students (58% male) who were assessed across the transition to high school (spring of 8th and 9th grade). Continuous involvement in academic activities across the transition and becoming involved (i.e., initiation) in community/service activities following the transition was associated with fewer depressive symptoms in the spring of 9th grade. Continuous involvement in sports and initiation of academic activities was associated with having more friendships. In addition, links between OAs and loneliness were only evident among females. There appear to be significant social benefits for OA involvement.

  16. LOCAL TEXTURE DESCRIPTION FRAMEWORK FOR TEXTURE BASED FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    R. Reena Rose

    2014-02-01

    Full Text Available Texture descriptors have an important role in recognizing face images. However, almost all the existing local texture descriptors use nearest neighbors to encode a texture pattern around a pixel. But in face images, most of the pixels have similar characteristics with that of its nearest neighbors because the skin covers large area in a face and the skin tone at neighboring regions are same. Therefore this paper presents a general framework called Local Texture Description Framework that uses only eight pixels which are at certain distance apart either circular or elliptical from the referenced pixel. Local texture description can be done using the foundation of any existing local texture descriptors. In this paper, the performance of the proposed framework is verified with three existing local texture descriptors Local Binary Pattern (LBP, Local Texture Pattern (LTP and Local Tetra Patterns (LTrPs for the five issues viz. facial expression, partial occlusion, illumination variation, pose variation and general recognition. Five benchmark databases JAFFE, Essex, Indian faces, AT&T and Georgia Tech are used for the experiments. Experimental results demonstrate that even with less number of patterns, the proposed framework could achieve higher recognition accuracy than that of their base models.

  17. High-speed laminar-turbulent boundary layer transition induced by a discrete roughness element

    Science.gov (United States)

    Iyer, Prahladh; Mahesh, Krishnan

    2013-11-01

    Direct numerical simulation (DNS) is used to study laminar to turbulent transition induced by a discrete hemispherical roughness element in a high-speed laminar boundary layer. The simulations are performed under conditions matching the experiments of Danehy et al. (AIAA Paper 2009-394, 2009) for free-stream Mach numbers of 3.37, 5.26 and 8.23. It is observed that the Mach 8.23 flow remains laminar downstream of the roughness, while the lower Mach numbers undergo transition. The Mach 3.37 flow undergoes transition closer to the bump when compared with Mach 5.26, in agreement with experimental observations. Transition is accompanied by an increase in Cf and Ch (Stanton number). Even for the case that did not undergo transition (Mach 8.23), streamwise vortices induced by the roughness cause a significant rise in Cf until 20 D downstream. The mean van Driest transformed velocity and Reynolds stress for Mach 3.37 and 5.26 show good agreement with available data. A local Reynolds number based on the wall properties is seen to correlate with the onset of transition for the cases considered. Partially supported by NASA.

  18. Theory of quantum metal to superconductor transitions in highly conducting systems

    Energy Technology Data Exchange (ETDEWEB)

    Spivak, B.

    2010-04-06

    We derive the theory of the quantum (zero temperature) superconductor to metal transition in disordered materials when the resistance of the normal metal near criticality is small compared to the quantum of resistivity. This can occur most readily in situations in which 'Anderson's theorem' does not apply. We explicitly study the transition in superconductor-metal composites, in an swave superconducting film in the presence of a magnetic field, and in a low temperature disordered d-wave superconductor. Near the point of the transition, the distribution of the superconducting order parameter is highly inhomogeneous. To describe this situation we employ a procedure which is similar to that introduced by Mott for description of the temperature dependence of the variable range hopping conduction. As the system approaches the point of the transition from the metal to the superconductor, the conductivity of the system diverges, and the Wiedemann-Franz law is violated. In the case of d-wave (or other exotic) superconductors we predict the existence of (at least) two sequential transitions as a function of increasing disorder: a d-wave to s-wave, and then an s-wave to metal transition.

  19. Magnetic-dipole transitions in highly charged ions as a basis of ultraprecise optical clocks.

    Science.gov (United States)

    Yudin, V I; Taichenachev, A V; Derevianko, A

    2014-12-05

    We evaluate the feasibility of using magnetic-dipole (M1) transitions in highly charged ions as a basis of an optical atomic clockwork of exceptional accuracy. We consider a range of possibilities, including M1 transitions between clock levels of the same fine-structure and hyperfine-structure manifolds. In highly charged ions these transitions lie in the optical part of the spectra and can be probed with lasers. The most direct advantage of our proposal comes from the low degeneracy of clock levels and the simplicity of atomic structure in combination with negligible quadrupolar shift. We demonstrate that such clocks can have projected fractional accuracies below the 10^{-20}-10^{-21} level for all common systematic effects, such as blackbody radiation, Zeeman, ac-Stark, and quadrupolar shifts.

  20. Crystal plasticity modeling of through-thickness texture heterogeneity in heavily rolled aluminum

    DEFF Research Database (Denmark)

    Delannay, Laurent; Mishin, Oleg V.

    2013-01-01

    The textures measured at different depths inside a cold rolled aluminium sheet are compared to results obtained by crystal plasticity predictions. Different assumptions about the micro-to-macro scale transitions are considered. The input texture reveals a through-thickness gradient that originate...

  1. Magnetic transition temperatures follow crystallographic symmetry in samarium under high-pressures and low-temperatures

    Science.gov (United States)

    Johnson, Craig R.; Tsoi, Georgiy M.; Vohra, Yogesh K.

    2017-02-01

    Magnetic ordering temperatures in rare earth metal samarium (Sm) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to high-pressure up to 47 GPa and low-temperature to 10 K. The two magnetic transitions at 106 K and 14 K in the α-Sm phase, attributed to antiferromagnetic ordering on hexagonal and cubic layers respectively, collapse in to one magnetic transition near 10 GPa when Sm assumes a double hexagonal close packed (dhcp) phase. On further increase in pressure above 34 GPa, the magnetic transitions split again as Sm adopts a hexagonal-hP3 structure indicating different magnetic transition temperatures for different crystallographic sites. A model for magnetic ordering for the hexagonal-hP3 phase in samarium has been proposed based on the experimental data. The magnetic transition temperatures closely follow the crystallographic symmetry during α-Sm  →  dhcp  →  fcc/dist.fcc  →  hP3 structure sequence at high-pressures and low-temperatures.

  2. Role of relativity in high-pressure phase transitions of thallium.

    Science.gov (United States)

    Kotmool, Komsilp; Chakraborty, Sudip; Bovornratanaraks, Thiti; Ahuja, Rajeev

    2017-02-20

    We demonstrate the relativistic effects in high-pressure phase transitions of heavy element thallium. The known first phase transition from h.c.p. to f.c.c. is initially investigated by various relativistic levels and exchange-correlation functionals as implemented in FPLO method, as well as scalar relativistic scheme within PAW formalism. The electronic structure calculations are interpreted from the perspective of energetic stability and electronic density of states. The full relativistic scheme (FR) within L(S)DA performs to be the scheme that resembles mostly with experimental results with a transition pressure of 3 GPa. The s-p hybridization and the valence-core overlapping of 6s and 5d states are the primary reasons behind the f.c.c. phase occurrence. A recent proposed phase, i.e., a body-centered tetragonal (b.c.t.) phase, is confirmed with a small distortion from the f.c.c. phase. We have also predicted a reversible b.c.t. → f.c.c. phase transition at 800 GPa. This finding has been suggested that almost all the III-A elements (Ga, In and Tl) exhibit the b.c.t. → f.c.c. phase transition at extremely high pressure.

  3. High-pressure phase transitions in the rare-earth orthoferrite LaFeO3.

    Science.gov (United States)

    Etter, Martin; Müller, Melanie; Hanfland, Michael; Dinnebier, Robert E

    2014-06-01

    Sequential Rietveld refinements were applied on high-pressure synchrotron powder X-ray diffraction measurements of lanthanum ferrite (LaFeO3) revealing two phase transitions on the room-temperature isotherm up to a pressure of 48 GPa. The first structural phase transition of second order occurs at a pressure of 21.1 GPa, changing the space group from Pbnm to Ibmm. The second transition, involving a isostructural first-order phase transition, occurs at approximately 38 GPa, indicating a high-spin to low-spin transition of the Fe(3+) ion. Following the behavior of the volume up to the hydrostatic limit of methanol-ethanol it was possible to use inverted equations of state (EoS) to determine a bulk modulus of B0 = 172 GPa and a corresponding pressure derivative of B'0 = 4.3. In addition, the linearized version of the inverted EoS were used to determine the corresponding moduli and pressure derivatives for each lattice direction.

  4. Laser textured surface gradients

    Science.gov (United States)

    Ta, Van Duong; Dunn, Andrew; Wasley, Thomas J.; Li, Ji; Kay, Robert W.; Stringer, Jonathan; Smith, Patrick J.; Esenturk, Emre; Connaughton, Colm; Shephard, Jonathan D.

    2016-05-01

    This work demonstrates a novel technique for fabricating surfaces with roughness and wettability gradients and their subsequent applications for chemical sensors. Surface roughness gradients on brass sheets are obtained directly by nanosecond laser texturing. When these structured surfaces are exposed to air, their wettability decreases with time (up to 20 days) achieving both spatial and temporal wettability gradients. The surfaces are responsive to organic solvents. Contact angles of a series of dilute isopropanol solutions decay exponentially with concentration. In particular, a fall of 132° in contact angle is observed on a surface gradient, one order of magnitude higher than the 14° observed for the unprocessed surface, when the isopropanol concentration increased from 0 to 15.6 wt%. As the wettability changes gradually over the surface, contact angle also changes correspondingly. This effect offers multi-sensitivity at different zones on the surface and is useful for accurate measurement of chemical concentration.

  5. Emotional effects of dynamic textures

    NARCIS (Netherlands)

    Toet, A.; Henselmans, M.; Lucassen, M.P.; Gevers, T.

    2011-01-01

    This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music) and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely

  6. Emotional Effects of Dynamic Textures

    Directory of Open Access Journals (Sweden)

    Alexander Toet

    2011-12-01

    Full Text Available This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely unknown, despite their natural ubiquity and increasing use in digital media. Participants watched a set of dynamic textures, representing either water or various different media, and self-reported their emotional experience. Motion complexity was found to have mildly relaxing and nondominant effects. In contrast, motion change complexity was found to be arousing and dominant. The speed of dynamics had arousing, dominant, and unpleasant effects. The amplitude of dynamics was also regarded as unpleasant. The regularity of the dynamics over the textures' area was found to be uninteresting, nondominant, mildly relaxing, and mildly pleasant. The spatial scale of the dynamics had an unpleasant, arousing, and dominant effect, which was larger for textures with diverse content than for water textures. For water textures, the effects of spatial contrast were arousing, dominant, interesting, and mildly unpleasant. None of these effects were observed for textures of diverse content. The current findings are relevant for the design and synthesis of affective multimedia content and for affective scene indexing and retrieval.

  7. Color texture measurement and segmentation

    NARCIS (Netherlands)

    Hoang, M.A.; Geusebroek, J.M.; Smeulders, A.W.M.

    2005-01-01

    In computer vision, meaurement of image properties such as color or texture is essential. In this paper, we propose a solid framework for the local measurement of texture in color images. We give a physical basis for the integration of the well-known Gabor filters with the measurement of color. Our

  8. Quantitative Characterisation of Surface Texture

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Lonardo, P.M.; Trumpold, H.

    2000-01-01

    This paper reviews the different methods used to give a quantitative characterisation of surface texture. The paper contains a review of conventional 2D as well as 3D roughness parameters, with particular emphasis on recent international standards and developments. It presents new texture...

  9. Texture of mayonnaise and dressing

    NARCIS (Netherlands)

    Terpstra, M.E.J.; Janssen, A.M.; Gemert, van L.J.; Doorn, van R.J.M.; Wijk, de R.A.; Weenen, H.; Linden, van der E.

    2003-01-01

    Relationships between sensory texture attributes and physical properties of mayonnaise and dressings have been explored. The focus of the work was in creaminess and related texture attributes. Samples ranging from 0-70% oil were tested sensorially by QDA-panels. Physical caharacterisation of these

  10. An integrated spectral-textural approach for environmental change monitoring and assessment: analyzing the dynamics of green covers in a highly developing region.

    Science.gov (United States)

    Sakieh, Yousef; Gholipour, Mostafa; Salmanmahiny, Abdolrassoul

    2016-04-01

    The present study compares the effectiveness of two common preclassification change detection (CD) methods that use two-dimensional data space of spectral-textural (S-T) change information. The methods are principal component analysis (PCA) and change vector analysis (CVA) in the Gorgan Township area, Golestn Province, Iran. A series of texture-based information was calculated mainly to separate those land use/land cover (LULC) conversions that are spectrally indistinguishable and also to provide a basis for automatic classification of S-T data space. Both methods were evaluated in terms of accuracy and the required time and expertise. Having the two-dimensional S-T data space generated, support vector machine (SVM) classifier was implemented to automatically extract changed pixels and the receiving operator characteristic (ROC) was employed to assess the accuracy of the output. According to the results, the study area has witnessed substantial mutual transformations between various LULCs among agricultural lands were the most dynamic category in the region. The PCA method applied to the S-T information achieved a ROC of 0.90-indicating an acceptable performance-while the S-T CVA method achieved a lower value of 0.75. The S-T PCA method was considerably less time-consuming and less expertise demanding as well as more accurate in our study area.

  11. Textural changes in metallurgical coke prepared with polyethylene

    Institute of Scientific and Technical Information of China (English)

    Stanislav S.Gornostayev; Jyrki J.Heino; Tommi M.T.Kokkonen; Hannu T.Makkonen; Satu M.M.Huttunen; Timo M.J.Fabritius

    2014-01-01

    The effect of high-density polyethylene (HDPE) on the textural features of experimental coke was investigated using polar-ized-light optical microscopy and wavelet-based image analysis. Metallurgical coke samples were prepared in a laboratory-scale furnace with 2.5%, 5.0%, 7.5%, 10.0%, and 12.5%HDPE by mass, and one sample was prepared by 100%coal. The amounts and distribution of textures (isotropic, mosaic and banded) and pores were obtained. The calculations reveal that the addition of HDPE results in a decrease of mosaic texture and an increase of isotropic texture. Ethylene formed from the decomposition of HDPE is considered as a probable reason for the texture modifications. The approach used in this study can be applied to indirect evaluation for the reactivity and strength of coke.

  12. Academic Achievement and Emotional Intelligence: Predicting the Successful Transition from High School to University

    Science.gov (United States)

    Parker, James D. A.; Duffy, Jon M.; Wood, Laura M.; Bond, Barbara J.; Hogan, Marjorie J.

    2005-01-01

    This study examined the impact of emotional intelligence (EI) on the successful transition from high school to university. The short form of the Emotional Quotient Inventory (EQ-i) was completed by 1,426 first-year students attending four different universities within the first week of classes (September). At the end of the academic year (May),…

  13. High-precision photometry by telescope defocusing - I. The transiting planetary system WASP-5

    DEFF Research Database (Denmark)

    Southworth, J.; Hinse, T. C.; Jørgensen, U. G.;

    2009-01-01

    We present high-precision photometry of two transit events of the extrasolar planetary system WASP-5, obtained with the Danish 1.54-m telescope at European Southern Obseratory La Silla. In order to minimize both random and flat-fielding errors, we defocused the telescope so its point spread...

  14. Managing the Transition to Ninth Grade in a Comprehensive Urban High School. Snapshot

    Science.gov (United States)

    Smith, Thomas J.

    2007-01-01

    This "snapshot" illustrates how one school is managing to make a positive difference for ninth graders. It describes the Ninth Grade Success Academy, a school-within-a-school at Thomas A. Edison High School in Philadelphia, Pennsylvania, which has a number of features specifically designed to help ninth-graders make successful transitions. A list…

  15. Assessment of Food Safety Knowledge of High School and Transition Teachers of Special Needs Students

    Science.gov (United States)

    Pivarnik, Lori F.; Patnoad, Martha S.; Richard, Nicole Leydon; Gable, Robert K.; Hirsch, Diane Wright; Madaus, Joseph; Scarpati, Stan; Carbone, Elena

    2009-01-01

    Adolescents with disabilities require access to general education and life skills instruction. Knowledge of food safety for this audience is important for health and valuable for work placement. The objective was to implement a survey to assess high school and transition special education teachers in RI, CT, and MA for food safety knowledge and…

  16. Supporting LGBTQ Students in High School for the College Transition: The Role of School Counselors

    Science.gov (United States)

    Jackson, Ken

    2017-01-01

    This phenomenological study sought to understand how lesbian, gay, bisexual, transgender, and queer (LGBTQ) college students described their high school experiences and their later transitions to college. The study data revealed five findings: (a) enduring unsupportive/hostile educational environments, (b) experiencing a lack of family and social…

  17. Experiences of Adolescents with Type 1 Diabetes as They Transition from Middle School to High School

    Science.gov (United States)

    Fleischman, Katie; Smothers, Melissa K.; Christianson, Heidi F.; Carter, Laura; Hains, Anthony A.; Davies, W. Hobart

    2011-01-01

    The purpose of this study was to explore the experiences of adolescents with Type 1 Diabetes Mellitus (T1DM) as they transitioned into high school in order to understand the contextual factors that impact diabetic health-related behaviors and self-identity. A qualitative interviewing methodology called consensual qualitative research (CQR) was…

  18. Childhood trauma and clinical outcome in patients at ultra-high risk of transition to psychosis

    NARCIS (Netherlands)

    Kraan, Tamar; van Dam, Daniella S.; Velthorst, Eva; de Ruigh, Esther L.; Nieman, Dorien H.; Durston, Sarah; Schothorst, Patricia; van der Gaag, Mark; de Haan, Lieuwe

    2015-01-01

    Background: Although transition rates in 'ultra-high risk' (UHR) for psychosis samples are declining,many young individuals at UHR still experience attenuated positive symptoms and impaired functioning at follow-up. The present study examined the association between a history of childhood trauma and

  19. Pathological Behavior of Renormalization-Group Maps at High Fields and Above the Transition Temperature

    NARCIS (Netherlands)

    Enter, Aernout C.D. van; Fernández, Roberto; Kotecký, Roman

    We show that decimation transformations applied to high-q Potts models result in non-Gibbsian measures even for temperatures higher than the transition temperature. We also show that majority transformations applied to the Ising model in a very strong field at low temperatures produce non-Gibbsian

  20. Assessment of Food Safety Knowledge of High School and Transition Teachers of Special Needs Students

    Science.gov (United States)

    Pivarnik, Lori F.; Patnoad, Martha S.; Richard, Nicole Leydon; Gable, Robert K.; Hirsch, Diane Wright; Madaus, Joseph; Scarpati, Stan; Carbone, Elena

    2009-01-01

    Adolescents with disabilities require access to general education and life skills instruction. Knowledge of food safety for this audience is important for health and valuable for work placement. The objective was to implement a survey to assess high school and transition special education teachers in RI, CT, and MA for food safety knowledge and…

  1. Processing and properties of textured potassium strontium niobate (KSr2Nb5O15) ceramic fibers--effect of texture on the electrical properties.

    Science.gov (United States)

    Alkoy, Sedat; Dursun, Sinan

    2013-10-01

    Textured ceramic fibers were fabricated from the tungsten-bronze-type piezoelectric (KSr2Nb5O15) . Development of crystallographic texture was evaluated through rocking curve analysis and a texture with Lotgering factor of 0.97 was achieved. 1-3 piezocomposites were prepared from the textured fibers and their electrical properties were evaluated. Highly enhanced properties that are 2 to 3 times higher than the random case were observed with increasing texture fraction with P(r) and d33 reaching 20 μC/cm(2) and 75 pC/N, respectively.

  2. BHQ revisited (2): Texture development

    Science.gov (United States)

    Kilian, Rüdiger; Heilbronner, Renée

    2016-04-01

    Analysis of crystallographic preferred orientations (CPO) is mostly used to derive the kinematics of flow or conditions and processes of deformation. Observations from naturally and experimentally deformed rocks indicate that specific texture types might relate to deformation conditions or flow laws - with a number of variables being based on assumptions that are not fully tested. For example, the activity of certain slip systems is interpreted from pole figure geometries assuming that grains are oriented such that the shear stress is minimized, thus enforcing specific c-axis and a-xis directions, so-called "easy glide" orientations. Black Hills Quartzite (BHQ) deformed experimentally in the dislocation creep regime reveals a CPO development that depends on finite strain (Heilbronner & Tullis, 2006). In that study the CPO development was tracked through the analysis of optically derived C-axis pole figures and corresponding orientation maps indicating a transition from a girdle distribution to a single maximum around the kinematic y-axis with increasing strain. In this contribution, we re-measure the same samples using EBSD. The availability of the full crystal orientations in combination with novel techniques of orientation and misorientation mapping and combinations of fabric and texture data allow us to analyze the texture development in more detail. Special emphasis is on (a) the ratio of glide to dynamic recrystallization, (b) the relation of grain scale strain to bulk strain and (c) the development of intragranular misorientations with increasing recrystallization and strain. One interesting result of our analysis concerns the inference of "easy glide" grains based on their c-axis direction. As it turns out, the alignment of -directions at the periphery of the pole figure is more rapidly attained than the clustering of the c-axis about the y-axis (classical interpretation for prism glide) or at the periphery (classical interpretation for basal glide). It

  3. Molecular Dynamical Simulation of Ice Phase Transition: Ice Ih to High-Density Amorphous

    Institute of Scientific and Technical Information of China (English)

    DONG Shun-Le; WANG Yan

    2005-01-01

    @@ We put 5kbar and 12kbar on perfect ice Ih lattice at 77K and 180K. After 30000 simulation steps (in units of 10-15 s), high-density amorphous ice is formed. Four-site simple-pair potential TIP4P is used for molecular interactions and the rigid molecular model is employed. Phase transition processes are fitted by an exponential function, and different phase transition times τ are obtained from O-O radial distribution functions (366 and 359fs for 77K and 180K) and O-O-O angle distribution functions (126 and 116fs for 77K and 180K).

  4. The insulating-to-superconducting transition in europium high-temperature superconducting ceramics

    CERN Document Server

    Rosenbaum, R

    1997-01-01

    Experiment resistivity data on high-temperature superconducting ceramics of fully oxygenated EuBa sub 2 Cu sub 3 sub - sub x Co sub x O sub y show that the insulating-to-superconducting transitions take place at liquid-helium temperature, provided that the cobalt fraction x exceeds 0.3. The resistivity follows a simple power-law dependence rho propor to T sup - sup 1 sup / sup 2 , attributed to electron-electron interactions. A model based upon intrinsic Josephson tunnelling junctions is suggested to explain the transition from insulating to superconducting states. (author)

  5. Low-level contrast statistics are diagnostic of invariance of natural textures.

    Science.gov (United States)

    Groen, Iris I A; Ghebreab, Sennay; Lamme, Victor A F; Scholte, H Steven

    2012-01-01

    Texture may provide important clues for real world object and scene perception. To be reliable, these clues should ideally be invariant to common viewing variations such as changes in illumination and orientation. In a large image database of natural materials, we found textures with low-level contrast statistics that varied substantially under viewing variations, as well as textures that remained relatively constant. This led us to ask whether textures with constant contrast statistics give rise to more invariant representations compared to other textures. To test this, we selected natural texture images with either high (HV) or low (LV) variance in contrast statistics and presented these to human observers. In two distinct behavioral categorization paradigms, participants more often judged HV textures as "different" compared to LV textures, showing that textures with constant contrast statistics are perceived as being more invariant. In a separate electroencephalogram (EEG) experiment, evoked responses to single texture images (single-image ERPs) were collected. The results show that differences in contrast statistics correlated with both early and late differences in occipital ERP amplitude between individual images. Importantly, ERP differences between images of HV textures were mainly driven by illumination angle, which was not the case for LV images: there, differences were completely driven by texture membership. These converging neural and behavioral results imply that some natural textures are surprisingly invariant to illumination changes and that low-level contrast statistics are diagnostic of the extent of this invariance.

  6. High Temperature Superconductivity in Praseodymium Doped (0%, 2%, 4%) in Melt-Textured Y(1-x)Pr(x)Ba2Cu3O(7-delta) Systems

    Science.gov (United States)

    James, Claudell

    1995-01-01

    A study of the magnetic and structural properties of the alloy Y(1-x)Pr(x)Ba2Cu3O(7-delta) of 0%, 2%, and 4% doping of praseodymium is presented. The resulting oxides of the alloy series are a high-temperature superconductor Y-Ba-Cu-O, which has an orthorhombic superconducting crystal-lattice. Magnetic relaxation studies have been performed on the Y-Pr-Ba-CuO bulk samples for field orientation parallel to the c-axis, using a vibrating sample magnetometer. Relaxation was measured at several temperatures to obtain the irreversible magnetization curves used for the Bean model. Magnetization current densities were derived from the relaxation data. Field and temperature dependence of the logarithmic flux-creep relaxation was measured in critical state. The data indicates that the effective activation energy U(eff) increases with increasing T between 77 K and 86 K. Also, the data shows that U(eff)(T) and superconducting transition temperature, Tc, decreased as the lattice parameters increased with increasing Pr ion concentration, x, for the corresponding Y(1-x)Pr(x)Ba(x)Cu3O(7-delta) oxides. One contribution to Tc decrease in this sampling is suspected to be due to the larger ionic radius of the Pr(3+) ion. The upper critical field (H(sub c2)) was measured in the presence of magnetic field parallel to the c axis. A linear temperature dependence with H(sub c2) was obtained.

  7. Numerical modeling of the transition from low to high confinement in magnetically confined plasma

    DEFF Research Database (Denmark)

    Rasmussen, Jens Juul; Nielsen, Anders Henry; Madsen, Jens;

    2016-01-01

    The transition dynamics from low (L) to high (H) mode confinement in magnetically confined plasmas is investigated using a four-field drift fluid model—HESEL (Hot Edge-Sol-Electrostatic). The model includes profile evolution and is solved in a 2D domain at the out-board mid-plane of a tokamak......–I–H transition with an intermediate I-phase displaying limit-cycle oscillations (LCO). The model recovers the power threshold for the L–H transition, the scaling of the threshold with the density and with the loss-rate in the SOL, indicating a decrease in power threshold when switching from single to double null...

  8. Phase transitions in Group III-V and II-VI semiconductors at high pressure

    Science.gov (United States)

    Yu, S. C.; Liu, C. Y.; Spain, I. L.; Skelton, E. F.

    1979-01-01

    The structures and transition pressures of Group III-V and II-VI semiconductors and of a pseudobinary system (Ga/x/In/1-x/Sb) have been investigated. Results indicate that GaP, InSb, GaSb, GaAs and possible AlP assume Metallic structures at high pressures; a tetragonal, beta-Sn-like structure is adopted by only InSb and GaSb. The rocksalt phase is preferred in InP, InAs, AlSb, ZnO and ZnS. The model of Van Vechten (1973) gives transition pressures which are in good agreement with measured values, but must be refined to account for the occurrence of the ionic rocksalt structure in some compounds. In addition, discrepancies between the theoretical scaling values for volume changes at the semiconductor-to-metal transitions are observed.

  9. Initial rigid response and softening transition of highly stretchable kirigami sheet materials

    CERN Document Server

    Isobe, Midori

    2016-01-01

    We study, experimentally and theoretically, the mechanical response of sheet materials on which line cracks or cuts are arranged in a simple pattern. Such sheet materials, often called kirigami (the Japanese words, kiri and gami, stand for cut and paper, respectively), demonstrate a unique mechanical response promising for various engineering applications such as stretchable batteries: kirigami sheets possess a mechanical regime in which sheets are highly stretchable and very soft compared with the original sheets without line cracks, by virtue of out-of-plane deformation. However, this regime starts after a transition from an initial stiff regime governed by in-plane deformation. In other words, the softness of the kirigami structure emerges as a result of a transition from the two-dimensional to three-dimensional deformation, i.e., from stretching to bending. We clarify the physical origins of the transition and mechanical regimes, which are revealed to be governed by simple scaling laws. The results could ...

  10. Rare twin linked to high-pressure phase transition in iron

    Energy Technology Data Exchange (ETDEWEB)

    Dougherty, L.M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: lmdough@lanl.gov; Gray, G.T.; Cerreta, E.K.; McCabe, R.J.; Field, R.D.; Bingert, J.F. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2009-05-15

    At approximately 13 GPa, body-centered cubic alpha-iron undergoes a fully reversible, pressure-induced phase transition into hexagonal close-packed epsilon-iron. Microstructural evidence of this phase transition has been identified in the fully reverted alpha-iron as a large number of {l_brace}3 3 2{r_brace}<113> twins found primarily as secondary twins within {l_brace}1 1 2{r_brace}<111> primary twins. The {l_brace}3 3 2{r_brace}<113> twins were produced during high-pressure shock-loading of 1018 steel at a peak pressure above the alpha-epsilon phase transition pressure. The twins were identified using electron backscattered diffraction and transmission electron microscopy.

  11. Multiple high-temperature transitions driven by dynamical structures in NaI

    Science.gov (United States)

    Manley, M. E.; Jeffries, J. R.; Lee, H.; Butch, N. P.; Zabalegui, A.; Abernathy, D. L.

    2014-06-01

    Multiple, consecutive high-temperature transitions in NaI involving dynamical order and/or localization in the energy-momentum spectrum but not in the average crystal structure are revealed by lattice dynamics, x-ray lattice spacing, and heat-capacity measurements. Distinctive energy-momentum patterns and lattice distortions indicate dynamical structures forming within randomly stacked planes, rather than the isolated point-defect-like intrinsic localized modes predicted. Transition entropies are accounted for by vibrational entropy changes, and the transition enthalpies are explained by the strain energy of forming stacking-fault-like planar distortions deduced from x-ray-diffraction peak shifts. The vibrational entropy of the dynamical structures stabilizes surrounding elastic distortions.

  12. Melting and High P-T Transitions of Hydrogen up to 300 GPa.

    Science.gov (United States)

    Zha, Chang-Sheng; Liu, Hanyu; Tse, John S; Hemley, Russell J

    2017-08-18

    High P-T Raman spectra of hydrogen in the vibron and lattice mode regions were measured up to 300 GPa and 900 K using externally heated diamond anvil cell techniques. A new melting line determined from the disappearance of lattice mode excitations was measured directly for the first time above 140 GPa. The results differ from theoretical predictions and extrapolations from lower pressure melting relations. In addition, discontinuities in Raman frequencies are observed as a function of pressure and temperature indicative of phase transition at these conditions. The appearance of a new Raman feature near 2700  cm^{-1} at ∼300  GPa and 370 K indicates the transformation to a new crystalline phase. Theoretical calculations of the spectrum suggest the new phase is the proposed Cmca-4 metallic phase. The transition pressure is close to that of a recently reported transition observed on dynamic compression.

  13. Quantum topological transition in hyperbolic metamaterials based on high Tc superconductors.

    Science.gov (United States)

    Smolyaninov, Igor I

    2014-07-30

    Hyperbolic metamaterials are known to exhibit a transition in the topology of the photon iso-frequency surface from a closed ellipsoid to an open hyperboloid, resulting in a considerable increase of the photonic density of states. This topological transition may also be described as a change of metric signature of the effective optical space. Here we demonstrate that high Tc superconductors exhibit hyperbolic metamaterial behavior in the far infrared and THz frequency ranges. In the THz range the hyperbolic behavior occurs only in the normal state, while no propagating photon modes exist in the superconducting state. Thus, a quantum topological transition may be observed for THz photons at zero temperature as a function of the external magnetic field, in which the effective Minkowski spacetime arises in the mixed state of the superconductor at some critical value of the external magnetic field. Nucleation of effective Minkowski spacetime occurs via the formation of quantized Abrikosov vortices.

  14. High-efficiency transition between rectangular waveguide and domino plasmonic waveguide

    Science.gov (United States)

    Liu, Liangliang; Li, Zhuo; Xu, Bingzheng; Gu, Changqing; Chen, Chen; Ning, Pingping; Yan, Jian; Chen, Xingyu

    2015-02-01

    In this work, we propose an optimized transition structure to realize smooth and high efficiency conversion from the guided wave supported by a conventional rectangular waveguide (CRW) to the domino plasmon polaritons (DPPs) supported by a domino plasmonic waveguide (DPW) and vice versa in the X-band (8.2GHz˜12.4GHz). This transition structure consists of two tapered CRWs connected by a gradient domino array with optimized gradient heights and lateral widths. Experimental results of the S-parameters show excellent agreement with the simulations and the optimization scheme can be readily extended to other bands. Furthermore, a domino plasmonic power divider is implemented to demonstrate the application of the transition structure in the integration of conventional microwave circuits with plasmonic devices.

  15. Model investigation of non-thermal phase transition in high energy collisions

    Institute of Scientific and Technical Information of China (English)

    王琴; 李治明; 刘连寿

    2000-01-01

    The non-thermal phase transition in high energy collisions is studied in detail in the frame-work of random cascade model. The relation between the characteristic parameter γq of phase transition and the rank q of moment is obtained using Monte Carlo simulation, and the existence of two phases in self-similar cascading multiparticle systems is shown. The relation between the critical point qc of phase transition on the fluctuation parameter a is obtained and compared with the experimental results from NA22. The same study is carried out also by analytical calculation under central limit ap-proximation. The range of validity of the central limit approximation is discussed.

  16. Behavior of Quasinormal Modes and high dimension RN-AdS Black Hole phase transition

    CERN Document Server

    Chabab, M; Iraoui, S; Masmar, K

    2016-01-01

    In this work we use the quasinormal frequencies of a massless scalar perturbation to probe the phase transition of the high dimension charged-AdS black hole. The signature of the critical behavior of this black hole solution is detected in the isobaric as well as in isothermal process. This paper is a natural generalization of \\cite{base} to higher dimensional spacetime. More precisely our study shows a clear signal for any dimension $d$ in the isobaric process. As to the isothermal case, we find out that this signature can be affected by other parameters like the pressure and the horizon radius. We conclude that the quasinormal modes can be an efficient tool to investigate the first order phase transition, but fail to disclose the signature of the second order phase transition.

  17. High-pressure elasticity of stishovite and the P42/mnm ⇌ Pnnm phase transition

    Science.gov (United States)

    Carpenter, Michael A.; Hemley, Russell J.; Mao, Ho-Kwang

    2000-05-01

    A Landau free energy expansion has been developed to describe the elastic constant variations of stishovite (SiO2) associated with the P42/mnm (rutile-type) ⇌ Pnnm (CaCl2-type) phase transition as a function of pressure. The transition appears to display classical second-order character, with an equilibrium transition pressure which is renormalized by coupling of the soft optic mode with spontaneous strain. Lattice parameter data from the literature show that the symmetry breaking strain is large, while the nonsymmetry breaking strains are small. These have been used to constrain the numerical values of the strain/order parameter coupling coefficients, which in turn have been used to constrain values for the Landau coefficients. When substituted into expressions for all the individual elastic constants, taking values for experimental and calculated values of the bare elastic constants from the literature, a clear view of the pattern of elastic constant variations is produced. Variations of P and S wave velocities derived from the calculated elastic constants for a second-order transition show a dip as the transition point is approached from high pressure and from low pressure but do not show a discontinuity. The velocity anomaly provides a signature for the presence of free silica in the lower mantle.

  18. Phase transition of a heavy-fermion superconductor in a high magnetic field: Entanglement analysis

    Science.gov (United States)

    Afzali, R.; Ebrahimian, N.

    2013-08-01

    When the magnetic field is only acting on the spin of electrons, a transition from a normal to a modulated superconducting state or Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting state may occur at low temperatures. A FFLO superconducting state, which accompanies an order parameter that oscillates spatially, may be stabilized by a high applied magnetic field or a molecular field. Quantum multipartite entanglement is a new procedure for investigating quantum phase transitions. In this article, we deal with the phase transition of the FFLO state of CeCoIn5 to a normal state by obtaining quantum multipartite entanglement of the system. For this purpose, using normal and anomalous Green functions and the density matrix, we obtain concurrence, as a measure of bipartite entanglement. Then, the order parameter and the magnetic -field dependence of multipartite entanglement in momentum space is calculated. The phase transition is determined, and the behavior of the system based on order parameter is discussed. Furthermore, the phase transitions of both the Bardeen-Cooper-Schrieffer (BCS) and FFLO states to the normal state are compared.

  19. Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

    Science.gov (United States)

    Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

    2013-01-01

    High-speed laminar-to-turbulent transition and turbulence affect the control of flight vehicles, the heat transfer rate to a flight vehicle's surface, the material selected to protect such vehicles from high heating loads, the ultimate weight of a flight vehicle due to the presence of thermal protection systems, the efficiency of fuel-air mixing processes in high-speed combustion applications, etc. Gaining a fundamental understanding of the physical mechanisms involved in the transition process will lead to the development of predictive capabilities that can identify transition location and its impact on parameters like surface heating. Currently, there is no general theory that can completely describe the transition-to-turbulence process. However, transition research has led to the identification of the predominant pathways by which this process occurs. For a truly physics-based model of transition to be developed, the individual stages in the paths leading to the onset of fully turbulent flow must be well understood. This requires that each pathway be computationally modeled and experimentally characterized and validated. This may also lead to the discovery of new physical pathways. This document is intended to describe molecular based measurement techniques that have been developed, addressing the needs of the high-speed transition-to-turbulence and high-speed turbulence research fields. In particular, we focus on techniques that have either been used to study high speed transition and turbulence or techniques that show promise for studying these flows. This review is not exhaustive. In addition to the probe-based techniques described in the previous paragraph, several other classes of measurement techniques that are, or could be, used to study high speed transition and turbulence are excluded from this manuscript. For example, surface measurement techniques such as pressure and temperature paint, phosphor thermography, skin friction measurements and

  20. On the texturization of monocrystalline silicon with sodium carbonate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vallejo, B.; Gonzalez-Manas, M.; Martinez-Lopez, J.; Caballero, M.A. [Departamento de Cristalografia, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real (Spain)

    2007-05-15

    The texturization of monocrystalline silicon wafers using sodium carbonate solution has been investigated. This etching process has been evaluated in terms of the surface morphology and the reflectance value. The results show that for low concentration of sodium carbonate the increase of texturing time decreases the reflectance value because of the change in morphology from hillocks to pyramidal; on the contrary for intermediate and high concentrations the increase of time has a detrimental effect on texturization because it increases both the pyramid sizes and their non-uniform distribution. However, a good cell performance could be obtained by etching at high concentrations and short times. (author)

  1. Micro-Texture Synthesis by Phase Randomization

    Directory of Open Access Journals (Sweden)

    Bruno Galerne

    2011-09-01

    Full Text Available This contribution is concerned with texture synthesis by example, the process of generating new texture images from a given sample. The Random Phase Noise algorithm presented here synthesizes a texture from an original image by simply randomizing its Fourier phase. It is able to reproduce textures which are characterized by their Fourier modulus, namely the random phase textures (or micro-textures.

  2. Possible field-tuned superconductor-insulator transition in high-Tc superconductors: implications for pairing at high magnetic fields.

    Science.gov (United States)

    Steiner, M A; Boebinger, G; Kapitulnik, A

    2005-03-18

    The behavior of some high temperature superconductors (HTSC), such as La(2-x)Sr(x)CuO(4) and Bi(2)Sr(2-x)La(x)CuO(6 + delta), at very high magnetic fields, is similar to that of thin films of amorphous InOx near the magnetic-field-tuned superconductor-insulator transition. Analyzing the InOx data at high fields in terms of persisting local pairing amplitude, we argue by analogy that the local pairing amplitude also persists well into the dissipative state of the HTSCs, the regime commonly denoted as the "normal state" in very high magnetic field experiments.

  3. Transpression and tectonic exhumation in the Heimefrontfjella, western orogenic front of the East African/Antarctic Orogen, revealed by quartz textures of high strain domains

    Directory of Open Access Journals (Sweden)

    Wilfried Bauer

    2016-06-01

    Full Text Available The metamorphic basement of the Heimefrontfjella in western Dronning Maud Land (Antarctica forms the western margin of the major ca. 500 million year old East African/East Antarctic Orogen that resulted from the collision of East Antarctica and greater India with the African cratons. The boundary between the tectonothermally overprinted part of the orogen and its north-western foreland is marked by the subvertical Heimefront Shear Zone. North-west of the Heimefront Shear Zone, numerous low-angle dipping ductile thrust zones cut through the Mesoproterozoic basement. Petrographic studies, optical quartz c-axis analyses and x-ray texture goniometry of quartz-rich mylonites were used to reveal the conditions that prevailed during the deformation. Mineral assemblages in thrust mylonites show that they were formed under greenschist-facies conditions. Quartz microstructures are characteristic of the subgrain rotation regime and oblique quartz lattice preferred orientations are typical of simple shear-dominated deformation. In contrast, in the Heimefront Shear Zone, quartz textures indicate mainly flattening strain with a minor dextral rotational component. These quartz microstructures and lattice preferred orientations show signs of post-tectonic annealing following the tectonic exhumation. The spatial relation between the sub-vertical Heimefront Shear Zone and the low-angle thrusts can be explained as being the result of strain partitioning during transpressive deformation. The pure-shear component with a weak dextral strike-slip was accommodated by the Heimefront Shear Zone, whereas the north–north-west directed thrusts accommodate the simple shear component with a tectonic transport towards the foreland of the orogen.

  4. Ethnicity distinctiveness through iris texture features using Gabor filters

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, Gugulethu P

    2017-02-01

    Full Text Available and ethnicity. Researchers have reported that iris texture features contain information that is inclined to human genetics and is highly discriminative between different eyes of different ethnicities. This work applies image processing and machine learning...

  5. Peak activation of lower limb musculature during high flexion kneeling and transitional movements.

    Science.gov (United States)

    Kingston, David C; Tennant, Liana M; Chong, Helen C; Acker, Stacey M

    2016-09-01

    Few studies have measured lower limb muscle activation during high knee flexion or investigated the effects of occupational safety footwear. Therefore, our understanding of injury and disease mechanisms, such as knee osteoarthritis, is limited for these high-risk postures. Peak activation was assessed in eight bilateral lower limb muscles for twelve male participants, while shod or barefoot. Transitions between standing and kneeling had peak quadriceps and tibialis anterior (TA) activations above 50% MVC. Static kneeling and simulated tasks performed when kneeling had peak TA activity above 15% MVC but below 10% MVC for remaining muscles. In three cases, peak muscle activity was significantly higher (mean 8.9% MVC) when shod. However, net compressive knee joint forces may not be significantly increased when shod. EMG should be used as a modelling input when estimating joint contact forces for these postures, considering the activation levels in the hamstrings and quadriceps muscles during transitions. Practitioner Summary: Kneeling transitional movements are used in activities of daily living and work but are linked to increased knee osteoarthritis risk. We found peak EMG activity of some lower limb muscles to be over 70% MVC during transitions and minimal influence of wearing safety footwear.

  6. Highly Accurate and Precise Infrared Transition Frequencies of the H_3^+ Cation

    Science.gov (United States)

    Perry, Adam J.; Markus, Charles R.; Hodges, James N.; Kocheril, G. Stephen; McCall, Benjamin J.

    2016-06-01

    Calculation of ab initio potential energy surfaces for molecules to high accuracy is only manageable for a handful of molecular systems. Among them is the simplest polyatomic molecule, the H_3^+ cation. In order to achieve a high degree of accuracy (transitions of H_3^+ with MHz-level precision, all of which have arisen from low lying rotational levels. Here we present new measurements of rovibrational transitions arising from higher rotational and vibrational levels. These transitions not only allow for probing higher energies on the potential energy surface, but through the use of combination differences, will ultimately lead to prediction of the "forbidden" rotational transitions with MHz-level accuracy. L.G. Diniz, J.R. Mohallem, A. Alijah, M. Pavanello, L. Adamowicz, O.L. Polyansky, J. Tennyson Phys. Rev. A (2013), 88, 032506 O.L. Polyansky, A. Alijah, N.F. Zobov, I.I. Mizus, R.I. Ovsyannikov, J. Tennyson, L. Lodi, T. Szidarovszky, A.G. Császár Phil. Trans. R. Soc. A (2012), 370, 5014 J.N. Hodges, A.J. Perry, P.A. Jenkins II, B.M. Siller, B.J. McCall J. Chem. Phys. (2013), 139, 164201 A.J. Perry, J.N. Hodges, C.R. Markus, G.S. Kocheril, B.J. McCall J. Molec. Spectrosc. (2015), 317, 71-73.

  7. Depth image enhancement using perceptual texture priors

    Science.gov (United States)

    Bang, Duhyeon; Shim, Hyunjung

    2015-03-01

    A depth camera is widely used in various applications because it provides a depth image of the scene in real time. However, due to the limited power consumption, the depth camera presents severe noises, incapable of providing the high quality 3D data. Although the smoothness prior is often employed to subside the depth noise, it discards the geometric details so to degrade the distance resolution and hinder achieving the realism in 3D contents. In this paper, we propose a perceptual-based depth image enhancement technique that automatically recovers the depth details of various textures, using a statistical framework inspired by human mechanism of perceiving surface details by texture priors. We construct the database composed of the high quality normals. Based on the recent studies in human visual perception (HVP), we select the pattern density as a primary feature to classify textures. Upon the classification results, we match and substitute the noisy input normals with high quality normals in the database. As a result, our method provides the high quality depth image preserving the surface details. We expect that our work is effective to enhance the details of depth image from 3D sensors and to provide a high-fidelity virtual reality experience.

  8. High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Richard T. Scalettar; Warren E. Pickett

    2005-08-02

    This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.

  9. 微型车刀微孔织构设计及高速微车削试验∗%Design of Micro Hole Texture Tool and Experimental Study on High Speed Micro-turning

    Institute of Scientific and Technical Information of China (English)

    于占江; 王雯; 张超楠; 许金凯

    2016-01-01

    Aimed at the serious problem of tool wear during micro⁃cutting process at high speed,the micro⁃hole texture was designed on tool face based on non⁃smooth technology of surface,and the dynamic simulation analysis of metal turning was carried out by using DEFORM⁃3D.The results show that the main cutting force,the maximum temperature of tool tip, and the wear loss on the rake face of the tools with micro⁃hole texture are decreased obviously as compared with the untex⁃ture tool.By utilizing micro⁃electric discharge machining ( EDM) technology,the micro⁃hole texture was machined in the tool surface,and a micro⁃machining experiment of Aluminium alloy of 6061 with the micro hole texture tool was performed by a self⁃made high⁃speed micro⁃turning experimental device.The cutting properties were evaluated from three aspects,in⁃cluding chip form,tool wear condition and roughness of machined surface.The experimental results show that the micro⁃hole texture improves the wear resistance of tools and the quality of machined surface.Moreover,the micro texture improves the chip form,and enhances the heat rejection and anti⁃sticking performance of tools.%针对微型刀具高速微切削过程中磨损严重的问题,基于表面非光滑技术,在刀具表面进行微孔织构设计,并采用Deform⁃3D进行金属切削动态模拟分析。分析表明,前刀面带有微孔织构的微型车刀主切削力、刀尖最高温度、刀具磨损量,与无织构车刀相比都明显降低。利用微细电火花加工技术在微型车刀表面加工微孔织构,使用自行研制的高速微车削实验装置进行6061铝合金的微加工实验,并从刀具表面磨损状况、切屑形态、已加工表面粗糙度3个方面进行评价。实验结果表明,微孔织构在提高刀具减磨性能和已加工表面质量方面效果良好,微织构改善了切屑形态,增强了刀具排热、抗黏结性能。

  10. Dynamic Texture Coding using Modified Haar Wavelet with CUDA Premanand

    Directory of Open Access Journals (Sweden)

    P Ghadekar

    2015-03-01

    Full Text Available Texture is an image having repetition of patterns. There are two types, static and dynamic texture. Static texture is an image having repetitions of patterns in the spatial domain. Dynamic texture is number of frames having repetitions in spatial and temporal domain. This paper introduces a novel method for dynamic texture coding to achieve higher compression ratio of dynamic texture using 2D-modified Haar wavelet transform. The dynamic texture video contains high redundant parts in spatial and temporal domain. Redundant parts can be removed to achieve high compression ratios with better visual quality. The modified Haar wavelet is used to exploit spatial and temporal correlations amongst the pixels. The YCbCr color model is used to exploit chromatic components as HVS is less sensitive to chrominance. To decrease the time complexity of algorithm parallel programming is done using CUDA (Compute Unified Device Architecture. GPU contains the number of cores as compared to CPU, which is utilized to reduce the time complexity of algorithms.

  11. Deformation Behavior across the Zircon-Scheelite Phase Transition

    Science.gov (United States)

    Yue, Binbin; Hong, Fang; Merkel, Sébastien; Tan, Dayong; Yan, Jinyuan; Chen, Bin; Mao, Ho-Kwang

    2016-09-01

    The pressure effects on plastic deformation and phase transformation mechanisms of materials are of great importance to both Earth science and technological applications. Zircon-type materials are abundant in both nature and the industrial field; however, there is still no in situ study of their deformation behavior. Here, by employing radial x-ray diffraction in a diamond anvil cell, we investigate the dislocation-induced texture evolution of zircon-type gadolinium vanadate (GdVO4 ) in situ under pressure and across its phase transitions to its high-pressure polymorphs. Zircon-type GdVO4 develops a (001) compression texture associated with dominant slip along ⟨100 ⟩{001 } starting from 5 GPa. This (001) texture transforms into a (110) texture during the zircon-scheelite phase transition. Our observation demonstrates a martensitic mechanism for the zircon-scheelite transformation. This work will help us understand the local deformation history in the upper mantle and transition zone and provides fundamental guidance on material design and processing for zircon-type materials.

  12. Deformation Behavior across the Zircon-Scheelite Phase Transition.

    Science.gov (United States)

    Yue, Binbin; Hong, Fang; Merkel, Sébastien; Tan, Dayong; Yan, Jinyuan; Chen, Bin; Mao, Ho-Kwang

    2016-09-23

    The pressure effects on plastic deformation and phase transformation mechanisms of materials are of great importance to both Earth science and technological applications. Zircon-type materials are abundant in both nature and the industrial field; however, there is still no in situ study of their deformation behavior. Here, by employing radial x-ray diffraction in a diamond anvil cell, we investigate the dislocation-induced texture evolution of zircon-type gadolinium vanadate (GdVO_{4}) in situ under pressure and across its phase transitions to its high-pressure polymorphs. Zircon-type GdVO_{4} develops a (001) compression texture associated with dominant slip along ⟨100⟩{001} starting from 5 GPa. This (001) texture transforms into a (110) texture during the zircon-scheelite phase transition. Our observation demonstrates a martensitic mechanism for the zircon-scheelite transformation. This work will help us understand the local deformation history in the upper mantle and transition zone and provides fundamental guidance on material design and processing for zircon-type materials.

  13. "Life Skills": A Single-Sex Classroom Intervention for Black Boys Transitioning from Middle School to High School

    Science.gov (United States)

    Flennaugh, Terry

    2017-01-01

    The transition from middle school to high school can be difficult for many students due to increases in school size, the structure of an academic schedule, and the complexity of social interactions in high school. However, Black boys face unique challenges during this transition period due to racism and structural inequalities. In response to…

  14. Correlation between texture and mechanical stress durability of thin aluminum films

    Energy Technology Data Exchange (ETDEWEB)

    Nüssl, R., E-mail: rudolf.nuessl@uct.ac.za [Institut für Physik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg (Germany); Jewula, T.; Ruile, W. [TDK Corporation, Systems, Acoustics, Waves Business Group, Anzingerstraße 13, 81617 Munich (Germany); Sulima, T.; Hansch, W. [Institut für Physik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85579 Neubiberg (Germany)

    2014-04-01

    In this article, differently textured aluminum (Al) metallizations of surface acoustic wave (SAW) devices have been exposed to cyclic mechanical stress in order to investigate a potential correlation between their texture and their mechanical stress durability. Samples of SAW devices with differently textured Al thin film electrodes have been manufactured, and texture measurements have been carried out on all samples with electron backscatter diffraction. Subsequently, the SAW devices have been operated at heavy electrical load until a defined mechanical fatigue of its Al electrodes occurred. SAW devices with highly textured Al electrodes showed almost 20 times higher power durability than SAW devices with untextured Al electrodes. We show that this increase in electrical power durability has to be fully attributed to the strongly enhanced mechanical stress durability of highly textured Al films. Furthermore, a positive correlation between the Al films' texture and its electrical conductivity has been found. - Highlights: • We show highly textured growth of thin Al films on a clean, monocrystalline LiTaO{sub 3} • Highly textured Al growth gets disturbed by prior photolithographic process steps • Power durability of a SAW device increases with texture of its metallization • Texture and mechanical stress durability of a thin Al film are tightly correlated.

  15. Texture and microstructure of the austenite in multiphased steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Regle, H. [ARCELOR Group, CMC-IRSID, Maizieres-les-Metz (France); Maruyama, N.; Yoshinaga, N. [Nippon Steel Corp. - Technical Development Bureau, Futtsu (Japan)

    2004-07-01

    In this paper we present results obtained in collaboration between NSC and Arcelor on the austenite of a multiphased steel and on a 70%Ni-30Fe alloy. The work concerns the formation of the crystallographic textures during the recrystallisation of austenite, since these textures have a strong influence, after the phase transformation, on the forming properties of the sheets. The microstructure and the textures of the austenite and the FeNi alloy were measured with X-Ray diffraction techniques and with EBSD on a high resolution FEG-SEM. (orig.)

  16. Selective Extraction of Entangled Textures via Adaptive PDE Transform

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2012-01-01

    Full Text Available Texture and feature extraction is an important research area with a wide range of applications in science and technology. Selective extraction of entangled textures is a challenging task due to spatial entanglement, orientation mixing, and high-frequency overlapping. The partial differential equation (PDE transform is an efficient method for functional mode decomposition. The present work introduces adaptive PDE transform algorithm to appropriately threshold the statistical variance of the local variation of functional modes. The proposed adaptive PDE transform is applied to the selective extraction of entangled textures. Successful separations of human face, clothes, background, natural landscape, text, forest, camouflaged sniper and neuron skeletons have validated the proposed method.

  17. Conductive and robust nitride buffer layers on biaxially textured substrates

    Science.gov (United States)

    Sankar, Sambasivan [Chicago, IL; Goyal, Amit [Knoxville, TN; Barnett, Scott A [Evanston, IL; Kim, Ilwon [Skokie, IL; Kroeger, Donald M [Knoxville, TN

    2009-03-31

    The present invention relates to epitaxial, electrically conducting and mechanically robust, cubic nitride buffer layers deposited epitaxially on biaxially textured substrates such as metals and alloys. The invention comprises of a biaxially textured substrate with epitaxial layers of nitrides. The invention also discloses a method to form such epitaxial layers using a high rate deposition method as well as without the use of forming gases. The invention further comprises epitaxial layers of oxides on the biaxially textured nitride layer. In some embodiments the article further comprises electromagnetic devices which may have superconducting properties.

  18. Enhancement of M1 Transition Rates at High Spin in 90Mo

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-Guang; YANG Chun-Xiang; LI Guang-Sheng; PENG Zhao-Hua; WEN Shu-Xian; HAN Guang-Bing; LI Cheng-Po; LU Shao-Jun; WU Shao-Yong; YUAN Guan-Jun

    2001-01-01

    High spin states in 90Mo have been populated through the 59Co (35C1,2p2n) 90Mo reaction at a beam energy of116 Me V. Level lifetimes of the positive-parity decay sequence are measured by using the Doppler shift attenuationmethod. It is observed that the M1 transition strengths show a substantial enhancement at high spin. Thisbehaviour may be related to occupation of high Ω orbitals by a pair of g9/2 protons. A deformed, oblate, shapeis suggested above the 13+ state.

  19. Quantum metallicity on the high-field side of the superconductor-insulator transition.

    Science.gov (United States)

    Baturina, T I; Strunk, C; Baklanov, M R; Satta, A

    2007-03-23

    We investigate ultrathin superconducting TiN films, which are very close to the localization threshold. Perpendicular magnetic field drives the films from the superconducting to an insulating state, with very high resistance. Further increase of the magnetic field leads to an exponential decay of the resistance towards a finite value. In the limit of low temperatures, the saturation value can be very accurately extrapolated to the universal quantum resistance h/e2. Our analysis suggests that at high magnetic fields a new ground state, distinct from the normal metallic state occurring above the superconducting transition temperature, is formed. A comparison with other studies on different materials indicates that the quantum metallic phase following the magnetic-field-induced insulating phase is a generic property of systems close to the disorder-driven superconductor-insulator transition.

  20. Laser spectroscopy on forbidden transitions in trapped highly charged Ar(13+) ions.

    Science.gov (United States)

    Mäckel, V; Klawitter, R; Brenner, G; Crespo López-Urrutia, J R; Ullrich, J

    2011-09-30

    We demonstrate resonant fluorescence laser spectroscopy in highly charged ions (HCI) stored in an electron beam ion trap by investigating the dipole-forbidden 1s(2)2s(2)2p (2)P(3/2)-(2)P(1/2) transition in boronlike Ar(13+) ions. Forced evaporative cooling yielded a high resolving power, resulting in an accurate wavelength determination to λ=441.255 68(26)  nm. By applying stronger cooling and two-photon excitation, new optical frequency standards based upon ultrastable transitions in such HCI could be realized in the future, e.g., for the search of time variations of the fine-structure constant.

  1. High pressure induced phase transition and superdiffusion in anomalous fluid confined in flexible nanopores

    Energy Technology Data Exchange (ETDEWEB)

    Bordin, José Rafael, E-mail: josebordin@unipampa.edu.br [Campus Caçapava do Sul, Universidade Federal do Pampa, Caixa Postal 15051, CEP 96570-000, Caçapava do Sul, RS (Brazil); Krott, Leandro B., E-mail: leandro.krott@ufrgs.br; Barbosa, Marcia C., E-mail: marcia.barbosa@ufrgs.br [Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

    2014-10-14

    The behavior of a confined spherical symmetric anomalous fluid under high external pressure was studied with Molecular Dynamics simulations. The fluid is modeled by a core-softened potential with two characteristic length scales, which in bulk reproduces the dynamical, thermodynamical, and structural anomalous behavior observed for water and other anomalous fluids. Our findings show that this system has a superdiffusion regime for sufficient high pressure and low temperature. As well, our results indicate that this superdiffusive regime is strongly related with the fluid structural properties and the superdiffusion to diffusion transition is a first order phase transition. We show how the simulation time and statistics are important to obtain the correct dynamical behavior of the confined fluid. Our results are discussed on the basis of the two length scales.

  2. Transition in Deformation Mechanism of AZ31 Magnesium Alloy during High-Temperature Tensile Deformation

    Directory of Open Access Journals (Sweden)

    Masafumi Noda

    2011-01-01

    Full Text Available Magnesium alloys can be used for reducing the weight of various structural products, because of their high specific strength. They have attracted considerable attention as materials with a reduced environmental load, since they help to save both resources and energy. In order to use Mg alloys for manufacturing vehicles, it is important to investigate the deformation mechanism and transition point for optimizing the material and vehicle design. In this study, we investigated the transition of the deformation mechanism during the high-temperature uniaxial tensile deformation of the AZ31 Mg alloy. At a test temperature of 523 K and an initial strain rate of 3×10−3 s-1, the AZ31 Mg alloy (mean grain size: ~5 μm exhibited stable deformation behavior and the deformation mechanism changed to one dominated by grain boundary sliding.

  3. On field effect studies and superconductor-insulator transition in high-Tc cuprates

    Science.gov (United States)

    Dubuis, G.; Bollinger, A. T.; Pavuna, D.; Božović, I.

    2013-07-01

    We summarize previous field effect studies in high- T c cuprates and then discuss our method to smoothly tune the carrier concentration of a cuprate film over a wide range using an applied electric field. We synthesized epitaxial one-unit-cell thick films of La2- x Sr x CuO4 and from them fabricated electric double layer transistor devices utilizing various gate electrolytes. We were able to vary the carrier density by about 0.08 carriers per Cu atom, with the resulting change in T c of 30 K. The superconductor-insulator transition occurred at the critical resistance very close to the quantum resistance for pairs, R Q = h/(2 e)2 = 6.5 kΩ. This is suggestive of a quantum phase transition, possibly driven by quantum phase fluctuations, between a "Bose insulator" and a high- T c superconductor state.

  4. Symmetry realization of texture zeros

    Energy Technology Data Exchange (ETDEWEB)

    Grimus, W. [Institut fuer Theoretische Physik, Universitaet Wien, Boltzmanngasse 5, 1090, Wien (Austria); Joshipura, A.S. [Physical Research Laboratory, 380009, Ahmedabad (India); Lavoura, L. [Centro de Fisica das Interaccoes Fundamentais, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, 1049-001, Lisboa (Portugal); Tanimoto, M. [Department of Physics, Niigata University, Ikarashi 2-8050, 950-2181, Niigata (Japan)

    2004-08-01

    We show that it is possible to enforce texture zeros in arbitrary entries of the fermion mass matrices by means of Abelian symmetries; in this way, many popular mass-matrix textures find a symmetry justification. We propose two alternative methods which allow one to place zeros in any number of elements of the mass matrices that one wants. They are applicable simultaneously in the quark and lepton sectors. They are also applicable in grand unified theories. The number of scalar fields required by our methods may be large; still, in many interesting cases this number can be reduced considerably. The larger the desired number of texture zeros is, the simpler are the models which reproduce the texture. (orig.)

  5. Symmetry realization of texture zeros

    CERN Document Server

    Grimus, Walter; Lavoura, L; Tanimoto, M

    2004-01-01

    We show that it is possible to enforce texture zeros in arbitrary entries of the fermion mass matrices by means of Abelian symmetries; in this way, many popular mass-matrix textures find a symmetry justification. We propose two alternative methods which allow to place zeros in any number of elements of the mass matrices that one wants. They are applicable simultaneously in the quark and lepton sectors. They are also applicable in Grand Unified Theories. The number of scalar fields required by our methods may be large; still, in many interesting cases this number can be reduced considerably. The larger the desired number of texture zeros is, the simpler are the models which reproduce the texture.

  6. High pressure phase transition and variation of elastic constants of diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Varshney, Dinesh; Sharma, P.; Kaurav, N. [School of Physics, Vigyan Bhawan, Devi Ahilya University, Takshila Campus, Indore 452017 (India); Shah, S. [Department of Physics, P. M. B. Gujarati Science College, Indore-452001 (India); Singh, R.K. [M. P. Bhoj (Open) University, Shivaji Nagar, Bhopal-462016 (India)

    2004-11-01

    A theoretical study of the high-pressure phase transition and elastic behavior in diluted magnetic semiconductors Zn{sub 0.83}Mn{sub 0.17}Se, using a three-body interaction (TBI) potential caused by the electron-shell deformation of the overlapping ions is carried out. The estimated values of phase transition pressure and the vast volume discontinuity in pressure-volume (PV) phase diagram indicate the structural phase transition from zincblende (B3) to rock salt (B1). The variation of second-order elastic constants with pressure resembles that observed in some binary semiconductors. The inconsistency in the deduced value of pressure derivative of second order elastic constant with the available data is attributed to the fact that we derive expressions neglecting thermal effects and assuming the overlap repulsion significant only up to nearest neighbors. The vdW interaction is effective in obtaining the thermodynamical parameters such as Debye temperature, Gruneisen parameter, thermal expansion coefficient, compressibility as well phase stability in diluted magnetic semiconductors. It is revealed that TBI model has a promise to predict the phase transition pressure and the pressure variation of elastic constants of other semiconductors as well. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. High-Speed Imaging Analysis of Register Transitions in Classically and Jazz-Trained Male Voices.

    Science.gov (United States)

    Dippold, Sebastian; Voigt, Daniel; Richter, Bernhard; Echternach, Matthias

    2015-01-01

    Little data are available concerning register functions in different styles of singing such as classically or jazz-trained voices. Differences between registers seem to be much more audible in jazz singing than classical singing, and so we hypothesized that classically trained singers exhibit a smoother register transition, stemming from more regular vocal fold oscillation patterns. High-speed digital imaging (HSDI) was used for 19 male singers (10 jazz-trained singers, 9 classically trained) who performed a glissando from modal to falsetto register across the register transition. Vocal fold oscillation patterns were analyzed in terms of different parameters of regularity such as relative average perturbation (RAP), correlation dimension (D2) and shimmer. HSDI observations showed more regular vocal fold oscillation patterns during the register transition for the classically trained singers. Additionally, the RAP and D2 values were generally lower and more consistent for the classically trained singers compared to the jazz singers. However, intergroup comparisons showed no statistically significant differences. Some of our results may support the hypothesis that classically trained singers exhibit a smoother register transition from modal to falsetto register. © 2015 S. Karger AG, Basel.

  8. Structures and phase transitions of ScH3 under high pressure

    Institute of Scientific and Technical Information of China (English)

    Kong Bo; Zhou Zhu-Wen; Chen De-Liang; Ling-hu Rong-Feng

    2013-01-01

    The structures and the phase transitions of ScH3 under high pressure are investigated using first-principles calculations.The calculated structural parameters at zero pressure agree well with the available experimental data.With increasing pressure,the transition sequence hcp (GdH3-type)→ C2/m →fcc→hcp (YH3-type)→Cmcm of ScH3 is predicted first; the corresponding transition pressures at 0 K are 23 GPa,25 GPa,348 GPa,and 477 GPa,respectively.The C2/m symmetry structure is a possible candidate but not a good one as the intermediate state from hexagonal to cubic in ScH3.On the other hand,via the analysis of the structures of hexagonal ScH2.9,cubic ScH3,and cubic ScH2,we find that the repulsive interactions of H-H atoms must play an important role in the transition from hexagonal to cubic.

  9. Two-electron and one-photon transitions in highly charged nickel-like ions

    Institute of Scientific and Technical Information of China (English)

    Xie Lu-You; Dong Chen-Zhong; Jiang Jun; Wan Jian-Jie; Yan Jun

    2008-01-01

    This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon(TEOP) transition from the(38-11/24dj)J:1,2 to(3p-13/24s1/2)J=1 and the(3p-11/2481/2)J=1 to(3d-1j4dj1)J=1,2 for highly charged Ni-like ions with atomic number Z in the range 47≤Z≤92.In the calculations,the multi-configuration Dirac-Fock method and corresponding program packages GRASP92 and REOS99 were used,and the relativistic effects,correlation effects and relaxation effects were considered systematically.It is found that the TEOP transitions are very sensitive to the correlation of electrons,and the probabilities will be enhanced sharply in some special Z regions along the isoelectronic sequence.The present TEOP transition wavelengths are compared with the available data from some previous publications,good agreement is obtained.

  10. The Visual N1 Is Sensitive to Deviations from Natural Texture Appearance.

    Science.gov (United States)

    Balas, Benjamin; Conlin, Catherine

    2015-01-01

    Disruptions of natural texture appearance are known to negatively impact performance in texture discrimination tasks, for example, such that contrast-negated textures, synthetic textures, and textures depicting abstract art are processed less efficiently than natural textures. Presently, we examined how visual ERP responses (the P1 and the N1 in particular) were affected by violations of natural texture appearance. We presented participants with images depicting either natural textures or synthetic textures made from the original stimuli. Both stimulus types were additionally rendered either in positive or negative contrast. These appearance manipulations (negation and texture synthesis) preserve a range of low-level features, but also disrupt higher-order aspects of texture appearance. We recorded continuous EEG while participants completed a same/different image discrimination task using these images and measured both the P1 and N1 components over occipital recording sites. While the P1 exhibited no sensitivity to either contrast polarity or real/synthetic appearance, the N1 was sensitive to both deviations from natural appearance. Polarity reversal and synthetic appearance affected the N1 latency differently, however, suggesting a differential impact on processing. Our results suggest that stages of visual processing indexed by the P1 and N1 are sensitive to high-order statistical regularities in natural textures and also suggest that distinct violations of natural appearance impact neural responses differently.

  11. The Visual N1 Is Sensitive to Deviations from Natural Texture Appearance.

    Directory of Open Access Journals (Sweden)

    Benjamin Balas

    Full Text Available Disruptions of natural texture appearance are known to negatively impact performance in texture discrimination tasks, for example, such that contrast-negated textures, synthetic textures, and textures depicting abstract art are processed less efficiently than natural textures. Presently, we examined how visual ERP responses (the P1 and the N1 in particular were affected by violations of natural texture appearance. We presented participants with images depicting either natural textures or synthetic textures made from the original stimuli. Both stimulus types were additionally rendered either in positive or negative contrast. These appearance manipulations (negation and texture synthesis preserve a range of low-level features, but also disrupt higher-order aspects of texture appearance. We recorded continuous EEG while participants completed a same/different image discrimination task using these images and measured both the P1 and N1 components over occipital recording sites. While the P1 exhibited no sensitivity to either contrast polarity or real/synthetic appearance, the N1 was sensitive to both deviations from natural appearance. Polarity reversal and synthetic appearance affected the N1 latency differently, however, suggesting a differential impact on processing. Our results suggest that stages of visual processing indexed by the P1 and N1 are sensitive to high-order statistical regularities in natural textures and also suggest that distinct violations of natural appearance impact neural responses differently.

  12. 超高压处理对圣女果质构及色泽的影响%Ultra-high Pressure Treatment on Texture and Color of Cherry Tomatoes

    Institute of Scientific and Technical Information of China (English)

    田莹; 侯建设; 薛风照; 李丹; 费斐

    2009-01-01

    利用超高压处理圣女果,探讨了处理压力对圣女果质构及色泽的影响,并对储藏期间色泽的变化进行记录.结果表明:处理压力上升到300 MPa时,圣女果硬度、脆度、黏着性等与对照相比变化不大.施加超过400MPa的压力,圣女果的质构变化明显.加压对圣女果色泽影响不大,圣女果经400 MPa以上压力处理后室温下储存,色泽稳定,可接受性好,这对于圣女果的加工保藏具有参考意义.%Cherry tomatoes were treated by ultra-high pressure. The effects on texture and color of cherry tomatoes were observed. The results showed that with pressure up to 300 MPa,the hardness,brittleness and adhesiveness of cherry tomatoes changed little compared to controls, apparent changes on texture can be detected when pressure went up to 400 MPa,500 MPa,600 MPa. The colors of cherry tomatoes could be kept quite well during 3 months with pressure above 400 MPa.

  13. Electric field induced phase transitions in polymers: a novel mechanism for high speed energy storage.

    Science.gov (United States)

    Ranjan, V; Nardelli, Marco Buongiorno; Bernholc, J

    2012-02-24

    Using first-principles simulations, we identify the microscopic origin of the nonlinear dielectric response and high energy density of polyvinylidene-fluoride-based polymers as a cooperative transition path that connects nonpolar and polar phases of the system. This path explores a complex torsional and rotational manifold and is thermodynamically and kinetically accessible at relatively low temperatures. Furthermore, the introduction of suitable copolymers significantly alters the energy barriers between phases providing tunability of both the energy density and the critical fields.

  14. High-order harmonic generation from gapped graphene: Perturbative response and transition to nonperturbative regime

    Science.gov (United States)

    Dimitrovski, Darko; Madsen, Lars Bojer; Pedersen, Thomas Garm

    2017-01-01

    We consider the interaction of gapped graphene in the two-band approximation using an explicit time-dependent approach. In addition to the full high-order harmonic generation (HHG) spectrum, we also obtain the perturbative harmonic response using the time-dependent method at photon energies covering all the significant features in the responses. The transition from the perturbative to the fully nonperturbative regime of HHG at these photon energies is studied in detail.

  15. Operation of the ATLAS Transition Radiation Tracker under very high irradiation at the CERN LHC

    CERN Document Server

    Åkesson, T; Baker, K; Baron, S; Benjamin, D; Bertelsen, H; Bondarenko, V; Bychkov, V; Callahan, J; Capéans-Garrido, M; Cardiel-Sas, L; Catinaccio, A; Cetin, S A; Cwetanski, Peter; Dam, M; Danielsson, H; Dittus, F; Dolgoshein, B A; Dressnandt, N; Driouichi, C; Ebenstein, W L; Eerola, Paule Anna Mari; Farthouat, Philippe; Fedin, O; Froidevaux, D; Gagnon, P; Grichkevitch, Y; Grigalashvili, N S; Hajduk, Z; Hansen, P; Kayumov, F; Keener, P T; Kekelidze, G D; Khristatchev, A; Konovalov, S; Koudine, L; Kovalenko, S; Kowalski, T; Kramarenko, V A; Krüger, K; Laritchev, A; Lichard, P; Luehring, F C; Lundberg, B; Maleev, V; McFarlane, K W; Mialkovski, V; Mindur, B; Mitsou, V A; Morozov, S; Munar, A; Muraviev, S; Nadtochy, A; Newcomer, F M; Ögren, H O; Oleshko, S; Olszowska, J; Passmore, S; Patritchev, S; Peshekhonov, V D; Petti, R; Price, M; Rembser, C; Rohne, O; Romaniouk, A; Rust, D R; Ryabov, Yu; Shchegelskii, V; Seliverstov, D M; Shin, T; Shmeleva, A; Smirnov, S; Sosnovtsev, V V; Soutchkov, V; Spiridenkov, E; Tikhomirov, V; Van Berg, R; Vassilakopoulos, V I; Vassilieva, L; Wang, C; Williams, H H; Zalite, A

    2004-01-01

    The ATLAS Transition Radiation Tracker (TRT) performance depends critically on the choice of the active gas and on its properties. The most important operational aspects, which have led to the final choice of the active gas for the operation of the TRT at the LHC design luminosity, are presented. The TRT performance expected at these conditions is reviewed, including pile-up effects at high luminosity. (9 refs).

  16. EUROMET SUPPLEMENTARY COMPARISON - SURFACE TEXTURE

    DEFF Research Database (Denmark)

    Koenders, L.; Andreasen, Jan Lasson; De Chiffre, Leonardo

    At the length meeting in Prague in Oct. 1999 a new comparison was suggested on surface texture. The last comparison on this field was finished in 1989. In the meantime the instrumentation, the standards and the written standards have been improved including some software filters. The pilot...... laboratories for this supplementary comparison on surface texture are the Centre for Geometrical Metrology at the Technical University of Denmark and the Micro- and Nanotopography laboratory at the Physikalisch-Technische Bundesanstalt, Germany....

  17. Laser surface texturing: chosen problems

    Science.gov (United States)

    Antoszewski, Bogdan; Sek, Piotr

    2013-01-01

    In modern machines for realization of goals like lubrication intesyfication, heat flow intensyfiacation, microflow simulation; more and more often surface texturing is used. It became possible due to develepment of technologies that use sources of concentrated energy stream like microlasers. The paper shows results of experimental investigation on seal rings made of silicon carbide. Experiments were conducted using seal rings without surface modifications and a seal rings with a geometrical surface textures made with Nd:Yag laser.

  18. CRUMB TEXTURE OF SPELT BREAD

    Directory of Open Access Journals (Sweden)

    Joanna Korczyk-Szabó

    2013-12-01

    Full Text Available Abstract The bread quality is considerably dependent on the texture characteristic of bread crumb. Crumb texture is an important quality indicator, as consumer prefer different bread taste. Texture analysis is primarily concerned with the evaluation of mechanical characteristics where a material is subjected to a controlled force from which a deformation curve of its response is generated. It is an objective physical examination of baked products and gives direct information on the product quality, oppositely to dough rheology tests what inform on the baking suitability of the flour, as raw material. This is why the texture analysis is one of the most helpful analytical methods of the product development. In the framework of our research during the years 2008 – 2009 were analyzed selected indicators for bread texture quality of five Triticum spelta L. varieties – Altgold, Oberkulmer Rotkorn, Ostro, Rubiota and Franckenkorn grown in an ecological system. The bread texture quality was evaluated on texture analyzer TA.XT Plus (Stable Micro Systems, Surrey, UK, following the AACC (74-09 standard method and expressed as crumb firmness (N, stiffness (N.mm-1 and relative elasticity (%. Our research proved that all selected indicators were significantly influenced by the year of growing and variety. The most soft bread was achieved in Rubiota, whereas bread crumb samples from Franckenkorn and Altgold were the most firm and stiff. Correlation analysis showed strong negative correlation between relative elasticity and bread crumb firmness as well as bread stiffness (-0.81++, -0.78++. The spelt grain can be a good source for making bread flour, but is closely dependent on choice of spelt variety. The spelt wheat bread crumb texture need further investigation as it can be a reliable quality parameter.

  19. Laboratory measurements of K-shell transitions in highly charged iron ions

    Science.gov (United States)

    Steinbrügge, René; Rudolph, Jan K.; Bernitt, Sven; Crespo López-Urrutia, José R.

    2016-09-01

    The x-ray spectra of celestial sources show a plethora of features originating from highly charged ions. These can be used to determine the flow, temperatures, and abundances of elements in the star, which are needed to benchmark-stellar evolution models. However, the underlying atomic transition data of the ions are often only known by theoretical calculations, thus testing them in laboratory measurements is crucial. We present our measurements of energies, natural linewidths, radiative and Auger decay rates for K-shell transitions in He-like to F-like iron ions. In this experiments, an electron beam ion trap was used to create a target of highly charged ions, which were resonantly excited by monochromatic light from the PETRA III synchrotron radiation source. Fluorescence was observed while simultaneously detecting photoionization by the change in the ionic charge state. This method, combined with the high resolution of the monochromator used, yields uncertainties on the ppm-level for the excitation energies and below 10% for the linewidths and transition rates, thus providing a valuable benchmark for atomic theory.

  20. Epitaxial hexagonal materials on IBAD-textured substrates

    Energy Technology Data Exchange (ETDEWEB)

    Matias, Vladimir; Yung, Christopher

    2017-08-15

    A multilayer structure including a hexagonal epitaxial layer, such as GaN or other group III-nitride (III-N) semiconductors, a <111> oriented textured layer, and a non-single crystal substrate, and methods for making the same. The textured layer has a crystalline alignment preferably formed by the ion-beam assisted deposition (IBAD) texturing process and can be biaxially aligned. The in-plane crystalline texture of the textured layer is sufficiently low to allow growth of high quality hexagonal material, but can still be significantly greater than the required in-plane crystalline texture of the hexagonal material. The IBAD process enables low-cost, large-area, flexible metal foil substrates to be used as potential alternatives to single-crystal sapphire and silicon for manufacture of electronic devices, enabling scaled-up roll-to-roll, sheet-to-sheet, or similar fabrication processes to be used. The user is able to choose a substrate for its mechanical and thermal properties, such as how well its coefficient of thermal expansion matches that of the hexagonal epitaxial layer, while choosing a textured layer that more closely lattice matches that layer.

  1. Titanite mineralization of bioalteration textures - the possible Ti precursor

    Science.gov (United States)

    Fliegel, D.; Wirth, R.; Simonetti, A.; McLoughlin, N.; Furnes, H.

    2009-12-01

    Bioalteration textures in the glassy rims of pillow basalts are found in in-situ oceanic crust of any age, in Phanerozoic ophiolites and from Precambrian greenstone belts. In ancient and metamorphosed rocks, these bioalteration textures are often mineralized by titanite (CaSiTiO5). The presence of titanite provides a way to constrain the age of these tracefossils using in-situ U-Pb dating with LA-MC-ICPMS. Until now the pathway for mineralization by titanite was unclear. We investigate here bioalteration textures from in-situ oceanic crust (DSDP 418A) using transmission electron microscopy (TEM), electron energy loss spectrometry (EELS) and scanning transmission X-ray microscopy (STXM). Using high spatial resolved spectroscopy, Ti enrichments and the Ti speciation was determined in the bioalteration textures. In addition TEM and EELS revealed the microstructure of the bioalteration textures and with STXM the redox chemistry at the interface between texture and host glass was examined. The observed Ti can serve as precursor for subsequent titanite mineralization during sub-seafloor and/or later regional metamorphism. We present here therefore a model for the mineralization and thus preservation of bioalteration textures in the oceanic crust.

  2. High-temperature and high-pressure phase transitions in uranium

    Science.gov (United States)

    Bouchet, J.; Bottin, F.

    2017-02-01

    The phase diagram of uranium has been explored up to 100 GPa and 2000 K by means of ab initio molecular dynamics (AIMD) simulations. The lattice dynamics and energetics of the stable phases observed experimentally in this range of pressure and temperature are studied in this work. The phonon spectra of the α and γ phases are shown to evolve strongly as a function of temperature, unveiling the huge anharmonic effects present in this material. If the elastics constants and the bulk and shear moduli of the γ phase do not disclose any temperature effects, the shear modulus of the α phase decreases strongly as a function of temperature. Using the pressure- and temperature-dependent vibrational density of states and the Gibbs free energy of these two structures, we found a line transition between the α and γ phases which slightly underestimates the experimental one. Coherently with experiments, the bct structure is never found stable between 0 and 100 GPa.

  3. A Neuro-Fuzzy based System for Classification of Natural Textures

    Science.gov (United States)

    Jiji, G. Wiselin

    2016-12-01

    A statistical approach based on the coordinated clusters representation of images is used for classification and recognition of textured images. In this paper, two issues are being addressed; one is the extraction of texture features from the fuzzy texture spectrum in the chromatic and achromatic domains from each colour component histogram of natural texture images and the second issue is the concept of a fusion of multiple classifiers. The implementation of an advanced neuro-fuzzy learning scheme has been also adopted in this paper. The results of classification tests show the high performance of the proposed method that may have industrial application for texture classification, when compared with other works.

  4. Stato dell’arte nella sintesi di texture sonore

    Directory of Open Access Journals (Sweden)

    Diemo Schwarz

    2016-06-01

    Full Text Available The synthesis of sound textures, such as rain, wind, or crowds, is an important application for cinema, multimedia creation, games and installations. However, despite the clearly defined requirements of naturalness and flexibility, no automatic method has yet found widespread use. After clarifying the definition, terminology, and usages of sound texture synthesis, we will give an overview of the many existing methods and approaches, and the few available software implementations, and classify them by the synthesis model they are based on, such as subtractive or additive synthesis, granular synthesis, corpus-based concatenative synthesis, wavelets, or physical modeling. Additionally, an overview is given over analysis methods used for sound texture synthesis, such as segmentation, statistical modeling, timbral analysis, and modeling of transitions.

  5. Audio Classification from Time-Frequency Texture

    CERN Document Server

    Yu, Guoshen

    2008-01-01

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.

  6. High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region.

    Science.gov (United States)

    Hirano, Y; Kiyama, S; Fujiwara, Y; Koguchi, H; Sakakita, H

    2015-11-01

    A high current density (≈3 mA/cm(2)) hydrogen ion beam source operating in an extremely low-energy region (E(ib) ≈ 150-200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when E(ib) is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.

  7. Dropwise condensation on inclined textured surfaces

    CERN Document Server

    Khandekar, Sameer

    2014-01-01

    Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

  8. Phase transitions of boron carbide: Pair interaction model of high carbon limit

    Science.gov (United States)

    Yao, Sanxi; Huhn, W. P.; Widom, M.

    2015-09-01

    Boron Carbide exhibits a broad composition range, implying a degree of intrinsic substitutional disorder. While the observed phase has rhombohedral symmetry (space group R 3 bar m), the enthalpy minimizing structure has lower, monoclinic, symmetry (space group Cm). The crystallographic primitive cell consists of a 12-atom icosahedron placed at the vertex of a rhombohedral lattice, together with a 3-atom chain along the 3-fold axis. In the limit of high carbon content, approaching 20% carbon, the icosahedra are usually of type B11 Cp, where the p indicates the carbon resides on a polar site, while the chains are of type C-B-C. We establish an atomic interaction model for this composition limit, fit to density functional theory total energies, that allows us to investigate the substitutional disorder using Monte Carlo simulations augmented by multiple histogram analysis. We find that the low temperature monoclinic Cm structure disorders through a pair of phase transitions, first via a 3-state Potts-like transition to space group R3m, then via an Ising-like transition to the experimentally observed R 3 bar m symmetry. The R3m and Cm phases are electrically polarized, while the high temperature R 3 bar m phase is nonpolar.

  9. RESEARCH ON SCHEME OF HIGH-SPEED ROTOR/WING TRANSITION HELICOPTER RD15

    Institute of Scientific and Technical Information of China (English)

    WANGHuan-jin; GAOZheng

    2004-01-01

    To analyze the existing schemes of high-speed rotorcrafts and some new technologies, a new conceptual sketch of the high-speed rotor/wing transition helicopter RD15 is proposed. The overall layout of the RD15 is given out and the transition process from the helicopter mode to the airplane mode is designed. The lift system consists of a circular disk-wing with four retractable blades. The technology of individual blade control is adopted for flight control in hover and low speed flight. The tail is a vectored thrust duct propeller. It can provide the anti-torque in hover, and offer the multi-directional controls and propulsion drive for the airplane mode flight. The aerodynamic characteristics and key technologies in the transition process for this layout, including the nose up angle of disk-wing, the length of the blade, rotation speed, pitch angle and other parameters, are theoretically ana lyzed and experimentally tested. Calculation and experiments show that the shift process of the lift, the power and controls are smooth, and the designed scheme is feasible.

  10. Unintentional carbide formation evidenced during high-vacuum magnetron sputtering of transition metal nitride thin films

    Science.gov (United States)

    Greczynski, G.; Mráz, S.; Hultman, L.; Schneider, J. M.

    2016-11-01

    Carbide signatures are ubiquitous in the surface analyses of industrially sputter-deposited transition metal nitride thin films grown with carbon-less source materials in typical high-vacuum systems. We use high-energy-resolution photoelectron spectroscopy to reveal details of carbon temporal chemical state evolution, from carbide formed during film growth to adventitious carbon adsorbed upon contact with air. Using in-situ grown Al capping layers that protect the as-deposited transition metal nitride surfaces from oxidation, it is shown that the carbide forms during film growth rather than as a result of post deposition atmosphere exposure. The XPS signature of carbides is masked by the presence of adventitious carbon contamination, appearing as soon as samples are exposed to atmosphere, and eventually disappears after one week-long storage in lab atmosphere. The concentration of carbon assigned to carbide species varies from 0.28 at% for ZrN sample, to 0.25 and 0.11 at% for TiN and HfN, respectively. These findings are relevant for numerous applications, as unintentionally formed impurity phases may dramatically alter catalytic activity, charge transport and mechanical properties by offsetting the onset of thermally-induced phase transitions. Therefore, the chemical state of C impurities in PVD-grown films should be carefully investigated.

  11. High transition frequencies of dynamic functional connectivity states in the creative brain

    Science.gov (United States)

    Li, Junchao; Zhang, Delong; Liang, Aiying; Liang, Bishan; Wang, Zengjian; Cai, Yuxuan; Gao, Mengxia; Gao, Zhenni; Chang, Song; Jiao, Bingqing; Huang, Ruiwang; Liu, Ming

    2017-01-01

    Creativity is thought to require the flexible reconfiguration of multiple brain regions that interact in transient and complex communication patterns. In contrast to prior emphases on searching for specific regions or networks associated with creative performance, we focused on exploring the association between the reconfiguration of dynamic functional connectivity states and creative ability. We hypothesized that a high frequency of dynamic functional connectivity state transitions will be associated with creative ability. To test this hypothesis, we recruited a high-creative group (HCG) and a low-creative group (LCG) of participants and collected resting-state fMRI (R-fMRI) data and Torrance Tests of Creative Thinking (TTCT) scores from each participant. By combining an independent component analysis with a dynamic network analysis approach, we discovered the HCG had more frequent transitions between dynamic functional connectivity (dFC) states than the LCG. Moreover, a confirmatory analysis using multiplication of temporal derivatives also indicated that there were more frequent dFC state transitions in the HCG. Taken together, these results provided empirical evidence for a linkage between the flexible reconfiguration of dynamic functional connectivity states and creative ability. These findings have the potential to provide new insights into the neural basis of creativity. PMID:28383052

  12. High transition frequencies of dynamic functional connectivity states in the creative brain.

    Science.gov (United States)

    Li, Junchao; Zhang, Delong; Liang, Aiying; Liang, Bishan; Wang, Zengjian; Cai, Yuxuan; Gao, Mengxia; Gao, Zhenni; Chang, Song; Jiao, Bingqing; Huang, Ruiwang; Liu, Ming

    2017-04-06

    Creativity is thought to require the flexible reconfiguration of multiple brain regions that interact in transient and complex communication patterns. In contrast to prior emphases on searching for specific regions or networks associated with creative performance, we focused on exploring the association between the reconfiguration of dynamic functional connectivity states and creative ability. We hypothesized that a high frequency of dynamic functional connectivity state transitions will be associated with creative ability. To test this hypothesis, we recruited a high-creative group (HCG) and a low-creative group (LCG) of participants and collected resting-state fMRI (R-fMRI) data and Torrance Tests of Creative Thinking (TTCT) scores from each participant. By combining an independent component analysis with a dynamic network analysis approach, we discovered the HCG had more frequent transitions between dynamic functional connectivity (dFC) states than the LCG. Moreover, a confirmatory analysis using multiplication of temporal derivatives also indicated that there were more frequent dFC state transitions in the HCG. Taken together, these results provided empirical evidence for a linkage between the flexible reconfiguration of dynamic functional connectivity states and creative ability. These findings have the potential to provide new insights into the neural basis of creativity.

  13. A new high-pressure phase transition in natural Fe-bearing orthoenstatite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jin S.; Dera, Przemyslaw; Bass, Jay D. (UC); (UIUC)

    2016-07-29

    Single-crystal X-ray structure refinements have been carried out on natural Fe-bearing orthoenstatite (OEN) at pressures up to 14.53 GPa. We report a new high-pressure phase transition from OEN to a monoclinic phase (HPCEN2) with space group P2{sub 1}/c, with a density change of {approx}1.9(3)%. The HPCEN2 phase is crystallographically different from low-pressure clinoenstatite (LPCEN), which also has P2{sub 1}/c symmetry. Upon release of pressure HPCEN2 reverts to OEN, and the transition pressure is bracketed between 9.96 and 14.26 GPa at room temperature. We find no evidence for a C2/c phase at high pressure. The lattice constants for the new phase at 14.26 GPa are a = 17.87(2), b = 8.526(9), c = 4.9485(10) {angstrom}, {beta} = 92.88(4){sup o} [{rho} = 3.658(9) g/cm{sup 3}]. Refinement of the new structure indicates rotation of tetrahedral chain as the key characteristic of this transition. This experiment points to the possibility of OEN and HPCEN2 as the stable phases in Earth's upper mantle.

  14. Comparative High Field Magneto-transport Of Rare Earth Oxypnictides With Maximum Transition Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Balakirev, Fedor F [Los Alamos National Laboratory; Migliori, A [MPA-NHMFL; Riggs, S [NHMFL-FSU; Hunte, F [NHMFL-FSU; Gurevich, A [NHMFL-FSU; Larbalestier, D [NHMFL-FSU; Boebinger, G [NHMFL-FSU; Jaroszynski, J [NHMFL-FSU; Ren, Z [CHINA; Lu, W [CHINA; Yang, J [CHINA; Shen, X [CHINA; Dong, X [CHINA; Zhao, Z [CHINA; Jin, R [ORNL; Sefat, A [ORNL; Mcguire, M [ORNL; Sales, B [ORNL; Christen, D [ORNL; Mandrus, D [ORNL

    2008-01-01

    We compare magnetotransport of the three iron-arsenide-based compounds ReFeAsO (Re=La, Sm, Nd) in very high DC and pulsed magnetic fields up to 45 and 54 T, respectively. Each sample studied exhibits a superconducting transition temperature near the maximum reported to date for that particular compound. While high magnetic fields do not suppress the superconducting state appreciably, the resistivity, Hall coefficient, and critical magnetic fields, taken together, suggest that the phenomenology and superconducting parameters of the oxypnictide superconductors bridges the gap between MgB{sub 2} and YBCO.

  15. High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics

    Science.gov (United States)

    Sirena, M.; Félix, L. Avilés; Haberkorn, N.

    2013-07-01

    High transition temperature superconductor (HTc)/SrTiO3 (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (λ ˜ 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (˜5 × 10-5 defects/μm2). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

  16. Crossover of high and low spin states in transition metal complexes

    CERN Document Server

    Raebiger, Hannes; Yasuhara, Hiroshi

    2012-01-01

    The stability of high vs. low spin states of transition metal complexes has been interpreted by ligand field theory, which is a perturbation theory of the electron-electron interaction. The present first principles calculation of a series of five cobalt complexes shows that the electron-electron interaction energy difference between the two states (i) exhibits the opposite trend to the total energy difference as the ligand nuclear charge varies, and (ii) is three or four orders of magnitude greater than the total energy difference. A new interpretation of the crossover of high and low spin states is given in terms of the chemical bonding.

  17. Structural Transition of Gd2O3:Eu Induced by High Pressure

    Institute of Scientific and Technical Information of China (English)

    CHEN Hai-Yong; ZOU Guang-Tian; HE Chun-Yuan; GAO Chun-Xiao; ZHANG Jia-Hua; GAO Shi-Yong; LU Hong-Liang; NIE Yan-Guang; LI Dong-Mei; KAN Shi-Hai

    2007-01-01

    @@ The structural transition of bulk and nano-size Gd2O3:Eu are studied by high pressure energy disperse x-ray diffraction (XRD) and high pressure photoluminescence. Our results show that in spite of different size of Gd2O3 particles, the cubic structure turns into a possible hexagonal one above 13.4 GPa. When the pressure is released,the sample reverses to the monoclinic structure. No cubic structure presents in the released samples. That is to say, the compression and relaxation of the sample leads to the cubic Gd2O3:Eu then turns into the monoclinic one.

  18. Turbulence at the transition to the high density H-mode in Wendelstein 7-AS plasmas

    DEFF Research Database (Denmark)

    Basse, N.P.; Zoletnik, S.; Baumel, S.

    2003-01-01

    Recently a new improved confinement regime was found in the Wendelstein 7-AS (W7-AS) stellarator (Renner H. et al 1989 Plasma Phys. Control. Fusion 31 1579). The discovery of this high density high confinement mode (HDH-mode) was facilitated by the installation of divertor modules. In this paper...... of the fluctuation level associated with the transition from NC- to HDH-mode. Correlation calculations on a 20 mus timescale between magnetic and density fluctuations lead to the result that the fluctuations are correlated in NC- but not in HDH-mode. Finally, a comparative analysis between the enhanced D-alpha H...

  19. Self-adaptive surface texture design for friction reduction across the lubrication regimes

    Science.gov (United States)

    Hsu, Stephen M.; Jing, Yang; Zhao, Fei

    2016-03-01

    Surface texturing has been shown to reduce friction and improve durability in mechanical face seals and metal forming operations, and lightly loaded thrust bearings. However, the success has been limited to conformal contacts and low load high speed operating conditions, i.e. hydrodynamic lubrication dominated regime. Both experiments and numerical simulations have shown that textural patterns, under higher loading and/or slower speeds may increase friction and even cause the lubrication film collapse. Specific designs of surface texture pattern, as its shape, depth and density, are required for different lubrication regimes. Our own study has shown (Hsu et al 2014 J. Phys. D: Appl. Phys. 47 335307) that large/shallow dimple reduces friction in hydrodynamic lubrication regime, whereas small/deep dimple shows benefit in mixed/boundary lubrication regimes (if the textural designs can provides hydrodynamic/hydrostatic lift forces to reduce the machine loading). In considering an engine component typically experiences duty cycles that may cross various lubrication regimes, a multiscale surface texture design appears attractive. This type of mixed shape texturing combines textures designed for low load, high speed operating conditions and the textures that are designed for high load, low speed operations. In this paper, two types of multiscale surface texture designs are presented. Ball-on-three-flats (BOTF) wear tester (under high loading conditions) is used to evaluate the performance of these multiscale texture designs along with the baselines of un-textured surfaces under the same surface preparation procedures. Two texture designs with only a single shape dimples are included in the study. Results suggest that multiscale surface texture design not only further reduces friction in comparison to the textures with single shape dimples, but also shows the effectiveness across hydrodynamic regimes to the mixed lubrication regimes.

  20. Embedded wavelet packet transform technique for texture compression

    Science.gov (United States)

    Li, Jin; Cheng, Po-Yuen; Kuo, C.-C. Jay

    1995-09-01

    A highly efficient texture compression scheme is proposed in this research. With this scheme, energy compaction of texture images is first achieved by the wavelet packet transform, and an embedding approach is then adopted for the coding of the wavelet packet transform coefficients. By comparing the proposed algorithm with the JPEG standard, FBI wavelet/scalar quantization standard and the EZW scheme with extensive experimental results, we observe a significant improvement in the rate-distortion performance and visual quality.

  1. Structure transition of multiferroic hexagonal TmMnO3 compound under high pressure

    Science.gov (United States)

    Wang, L. J.; Feng, S. M.; Zhu, J. L.; Liu, Q. Q.; Li, Y. C.; Li, X. D.; Liu, J.; Jin, C. Q.

    2010-06-01

    The high-pressure-induced structure transition in multiferroic hexagonal TmMnO3 (h-TmMnO3) has been investigated using an in situ angle-dispersive synchrotron X-ray diffraction technique in a diamond anvil cell. The experimental results show that the phase transition from ambient hexagonal to orthorhombic structure with space group Pbnm begins around 10.2 GPa. The Rietveld refinement method was used to determine the lattice parameters and lattice compressibility of the h-TmMnO3 compound from 0.8 to 28.6 GPa. The pressure evolution of average bond distances and bond angles between the Mn and O atoms in the ab-plane was obtained. The magnetic properties under different pressures as well as their effect on multiferroic properties are discussed using extrapolations from the empirical relation of magnetic order versus rare-earth ionic radius.

  2. A compact ultranarrow high-power laser system for experiments with 578 nm ytterbium clock transition

    Energy Technology Data Exchange (ETDEWEB)

    Cappellini, G., E-mail: cappellini@lens.unifi.it [LENS European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino (Italy); Lombardi, P. [Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino (Italy); INO-CNR Istituto Nazionale di Ottica del CNR, Sezione di Sesto Fiorentino, 50019 Sesto Fiorentino (Italy); Mancini, M.; Pagano, G. [Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino (Italy); Pizzocaro, M. [INRIM Istituto Nazionale di Ricerca Metrologica, Torino 10135 (Italy); Fallani, L. [LENS European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino (Italy); Department of Physics and Astronomy, University of Florence, 50019 Sesto Fiorentino (Italy); Catani, J. [LENS European Laboratory for Nonlinear Spectroscopy, 50019 Sesto Fiorentino (Italy); INO-CNR Istituto Nazionale di Ottica del CNR, Sezione di Sesto Fiorentino, 50019 Sesto Fiorentino (Italy)

    2015-07-15

    In this paper, we present the realization of a compact, high-power laser system able to excite the ytterbium clock transition at 578 nm. Starting from an external-cavity laser based on a quantum dot chip at 1156 nm with an intra-cavity electro-optic modulator, we were able to obtain up to 60 mW of visible light at 578 nm via frequency doubling. The laser is locked with a 500 kHz bandwidth to an ultra-low-expansion glass cavity stabilized at its zero coefficient of thermal expansion temperature through an original thermal insulation and correction system. This laser allowed the observation of the clock transition in fermionic {sup 173}Y b with a <50 Hz linewidth over 5 min, limited only by a residual frequency drift of some 0.1 Hz/s.

  3. Structural stability and phase transition of Bi 2 Te 3 under high pressure and low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. L.; Zhang, S. J.; Zhu, J. L.; Liu, Q. Q.; Wang, X. C.; Jin, C. Q.; Yu, J. C.

    2017-09-01

    Structural stability and phase transition of topological insulator Bi2Te3 were studied via angle-dispersive synchrotron radiation X-ray diffraction under high pressure and low temperature condition. The results manifest that the R-3m phase (phase I) is stable at 8 K over the pressure range up to 10 GPa and phase transition occurs between 8 K and 45 K at 8 GPa. According to the Birch-Murnaghan equation of state, the bulk modulus at ambient pressure B0 was estimated to be 45 ± 3 GPa with the assumption of B0' = 4. The structural robustness of phase I at 8 K suggests that the superconductivity below 10 GPa is related to phase I. Topological properties of superconducting Bi2Te3 phase under pressure were discussed.

  4. The Phase Transition of Eu2O3 under High Pressures

    Institute of Scientific and Technical Information of China (English)

    JIANG Sheng; BAI Li-Gang; LIU Jing; XIAO Wan-Sheng; LI Xiao-Dong; LI Yan-Chun; TANG Ling-Yun; ZHANG Yu-Feng; ZHANG De-Chun; ZHENG Li-Rong

    2009-01-01

    Pressure-induced phase transition of cubic Eu2Oa is studied by angle-dispersive x-ray diffraction (ADXD) up to 42.3 GPa at room temperature. A structural transformation from a cubic phase to a hexagonal phase is observed,which starts at 5.0 GPa and finishes at about 13.1 GPa. The phase transition leads to a volume collapse of 9.0% at 8.6 GPa. The hexagonal phase of Eu2O3 maintains stable up to the highest experiment pressure. After release of pressure, the high-pressure phase transforms to a monoclinic phase. The pressure-volume data are fitted with the Birch-Murnaghan equation of state. The bulk moduli obtained upon compression from the fitting are 145(2) GPa and 151(6) GPa for the cubic and hexagonal phases, respectively, when their first pressure derivatives are fixed at 4.

  5. A covariant model for the gamma N -> N(1535) transition at high momentum transfer

    CERN Document Server

    Ramalho, G

    2011-01-01

    A relativistic constituent quark model is applied to the gamma N -> N(1535) transition. The N(1535) wave function is determined by extending the covariant spectator quark model, previously developed for the nucleon, to the S11 resonance. The model allows us to calculate the valence quark contributions to the gamma N -> N(1535) transition form factors. Because of the nucleon and N(1535) structure the model is valid only for Q^2> 2.3 GeV^2. The results are compared with the experimental data for the electromagnetic form factors F1* and F2* and the helicity amplitudes A_1/2 and S_1/2, at high Q^2.

  6. A covariant model for the gamma N -> N(1535) transition at high momentum transfer

    Energy Technology Data Exchange (ETDEWEB)

    G. Ramalho, M.T. Pena

    2011-08-01

    A relativistic constituent quark model is applied to the gamma N -> N(1535) transition. The N(1535) wave function is determined by extending the covariant spectator quark model, previously developed for the nucleon, to the S11 resonance. The model allows us to calculate the valence quark contributions to the gamma N -> N(1535) transition form factors. Because of the nucleon and N(1535) structure the model is valid only for Q^2> 2.3 GeV^2. The results are compared with the experimental data for the electromagnetic form factors F1* and F2* and the helicity amplitudes A_1/2 and S_1/2, at high Q^2.

  7. Coexisting shape- and high-K isomers in the shape transitional nucleus {sup 188}Pt

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, S., E-mail: somm@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Biswas, D.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Tandel, S.K. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Danu, L.S.; Joshi, B.N.; Prajapati, G.K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nag, Somnath [Dept. of Physics, IIT Kharagpur, Kharagpur 721302 (India); Trivedi, T.; Saha, S.; Sethi, J.; Palit, R. [Dept. of Nuclear and Atomic Physics, TIFR, Mumbai 400005 (India); Joshi, P.K. [Homi Bhabha Centre for Science Education, TIFR, Mumbai 400088 (India)

    2014-12-12

    A high-spin study of the shape transitional nucleus {sup 188}Pt reveals the unusual coexistence of both shape- and K-isomeric states. Reduced B(E2) transition probabilities for decays from these states inferred from the data clearly establish their hindered character. In addition to other excited structures, a rotational band built upon the K isomer is identified, and its configuration has been assigned through an analysis of alignments and branching ratios. The shape evolution with spin in this nucleus has been inferred from both experimental observables and cranking calculations. The yrast positive parity structure appears to evolve from a near-prolate deformed shape through triaxial at intermediate excitation, and eventually to oblate at the highest spins.

  8. Structural and magnetic phase transitions in gadolinium under high pressures and low temperatures

    Science.gov (United States)

    Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; Vohra, Yogesh K.

    2014-10-01

    High pressure structural transition studies have been carried out on rare earth metal gadolinium in a diamond anvil cell at room temperature to 169 GPa. Gadolinium has been compressed to 38% of its initial volume at this pressure. With increasing pressure, a crystal structure sequence of hcp → Sm-type → dhcp → fcc → dfcc → monoclinic has been observed in our studies on gadolinium. The measured equation of state of gadolinium is presented to 169 GPa at ambient temperature. Magnetic ordering temperature of gadolinium has been studied using designer diamond anvils to a pressure of 25 GPa and a temperature of 10 K. The magnetic ordering temperature has been determined from the four-point electrical resistivity measurements carried out on gadolinium. Our experiments show that the magnetic transition temperature decreases with increasing pressure to 19 GPa and then increases when gadolinium is subjected to higher pressures.

  9. High-field superconductivity at an electronic topological transition in URhGe

    Science.gov (United States)

    Yelland, E. A.; Barraclough, J. M.; Wang, W.; Kamenev, K. V.; Huxley, A. D.

    2011-11-01

    The emergence of superconductivity at high magnetic fields in URhGe is regarded as a paradigm for new state formation approaching a quantum critical point. Until now, a divergence of the quasiparticle mass at the metamagnetic transition was considered essential for superconductivity to survive at magnetic fields above 30T. Here we report the observation of quantum oscillations in URhGe revealing a tiny pocket of heavy quasiparticles that shrinks continuously with increasing magnetic field, and finally disappears at a topological Fermi surface transition close to or at the metamagnetic field. The quasiparticle mass decreases and remains finite, implying that the Fermi velocity vanishes due to the collapse of the Fermi wavevector. This offers a novel explanation for the re-emergence of superconductivity at extreme magnetic fields and makes URhGe the first proven example of a material where magnetic field-tuning of the Fermi surface, rather than quantum criticality alone, governs quantum phase formation.

  10. High-temperature phase transitions in SrHfO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B.J.; Howard, C.J. [School of Chemistry, The University of Sydney, Sydney, New South Wales 2006 (Australia); Chakoumakos, B.C. [Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    1999-08-01

    The crystal structure of SrHfO{sub 3} has been studied at high temperatures using powder neutron diffraction and the Rietveld method. From 300 K to approximately 670 K the structure of SrHfO{sub 3} is orthorhombic ({ital Pnma}). By 870 K the material adopts a second orthorhombic structure ({ital Cmcm}). The material then undergoes a further phase transition and is tetragonal (I4/mcm) from {approximately}1000 to 1353 K. At higher temperatures ({gt}1360 K) the structure is the ideal cubic perovskite (Pm{bar 3}m). The angle of rotation of the oxygen octahedron in the tetragonal phase is taken as the order parameter and its temperature variation is consistent with a second order phase transition. {copyright} {ital 1999} {ital The American Physical Society}

  11. Lizard-Skin Surface Texture

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1 The south polar region of Mars is covered seasonally with translucent carbon dioxide ice. In the spring gas subliming (evaporating) from the underside of the seasonal layer of ice bursts through weak spots, carrying dust from below with it, to form numerous dust fans aligned in the direction of the prevailing wind. The dust gets trapped in the shallow grooves on the surface, helping to define the small-scale structure of the surface. The surface texture is reminiscent of lizard skin (figure 1). Observation Geometry Image PSP_003730_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 14-May-2007. The complete image is centered at -85.2 degrees latitude, 181.5 degrees East longitude. The range to the target site was 248.5 km (155.3 miles). At this distance the image scale is 24.9 cm/pixel (with 1 x 1 binning) so objects 75 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 06:04 PM and the scene is illuminated from the west with a solar incidence angle of 69 degrees, thus the sun was about 21 degrees above the horizon. At a solar longitude of 237.5 degrees, the season on Mars is Northern Autumn.

  12. Texturing of sodium bismuth titanate-barium titanate ceramics by templated grain growth

    Science.gov (United States)

    Yilmaz, Huseyin

    2002-01-01

    Sodium bismuth titanate modified with barium titanate, (Na1/2Bi 1/2)TiO3-BaTiO3 (NBT-BT), is a candidate lead-free piezoelectric material which has been shown to have comparatively high piezoelectric response. In this work, textured (Na1/2Bi1/2)TiO 3-BaTiO3 (5.5mol% BaTiO3) ceramics with pc (where pc denotes the pseudocubic perovskite cell) orientation were fabricated by Templated Grain Growth (TGG) or Reactive Templated Grain Growth (RTGG) using anisotropically shaped template particles. In the case of TGG, molten salt synthesized SrTiO3 platelets were tape cast with a (Na1/2Bi1/2)TiO3-5.5mol%BaTiO3 powder and sintered at 1200°C for up to 12 hours. For the RTGG approach, Bi4Ti3O12 (BiT) platelets were tape cast with a Na2CO3, Bi2O3, TiO 2, and BaCO3 powder mixture and reactively sintered. The TGG approach using SrTiO3 templates gave stronger texture along [001] compared to the RTGG approach using BiT templates. The textured ceramics were characterized by X-ray and electron backscatter diffraction for the quality of texture. The texture function was quantified by the Lotgering factor, rocking curve, pole figures, inverse pole figures, and orientation imaging microscopy. Electrical and electromechanical property characterization of randomly oriented and pc textured (Na1/2Bi1/2)TiO 3-5.5 mol% BaTiO3 rhombohedral ceramics showed 0.26% strain at 70 kV/cm, d33 coefficients over 500 pC/N have been obtained for highly textured samples (f ˜ 90%). The piezoelectric coefficient from Berlincourt was d33 ˜ 200 pC/N. The materials show considerable hysteresis. The presence of hysteresis in the unipolar-electric field curve is probably linked to the ferroelastic phase transition seen in the (Na 1/2Bi1/2)TiO3 system on cooling from high temperature at ˜520°C. The macroscopic physical properties (remanent polarization, dielectric constant, and piezoelectric coefficient) of random and textured ([001] pc) rhombohedral perovskites were estimated by linear averaging of single

  13. Texture coding in the rat whisker system: slip-stick versus differential resonance.

    Directory of Open Access Journals (Sweden)

    Jason Wolfe

    2008-08-01

    Full Text Available Rats discriminate surface textures using their whiskers (vibrissae, but how whiskers extract texture information, and how this information is encoded by the brain, are not known. In the resonance model, whisker motion across different textures excites mechanical resonance in distinct subsets of whiskers, due to variation across whiskers in resonance frequency, which varies with whisker length. Texture information is therefore encoded by the spatial pattern of activated whiskers. In the competing kinetic signature model, different textures excite resonance equally across whiskers, and instead, texture is encoded by characteristic, nonuniform temporal patterns of whisker motion. We tested these models by measuring whisker motion in awake, behaving rats whisking in air and onto sandpaper surfaces. Resonant motion was prominent during whisking in air, with fundamental frequencies ranging from approximately 35 Hz for the long Delta whisker to approximately 110 Hz for the shorter D3 whisker. Resonant vibrations also occurred while whisking against textures, but the amplitude of resonance within single whiskers was independent of texture, contradicting the resonance model. Rather, whiskers resonated transiently during discrete, high-velocity, and high-acceleration slip-stick events, which occurred prominently during whisking on surfaces. The rate and magnitude of slip-stick events varied systematically with texture. These results suggest that texture is encoded not by differential resonant motion across whiskers, but by the magnitude and temporal pattern of slip-stick motion. These findings predict a temporal code for texture in neural spike trains.

  14. Motion texture using symmetric property and graphcut algorithm

    Institute of Scientific and Technical Information of China (English)

    SHEN Jian-bing; JIN Xiao-gang; ZHOU Chuan; ZHAO Han-li

    2006-01-01

    In this paper, a novel motion texture approach is presented for synthesizing long character motion (e.g., kungfu) that is similar to the original short input motion. First, a new motion with repeated frames is genterated by exploiting the symmetric properties of the frames and reversing the motion sequence playback in a given motion sequence. Then, the order of the above motion sequence is rearranged by putting the start and the end frames together. The graphcut algorithm is used to seamlessly synthesize the transition between the start and the end frames, which is noted as graphcut-based motion-texton. Finally, we utilize the motion-textons to synthesize long motion texture, which can be patched together like the image texture synthesis method using graphcut algorithm, and automatically form a long motion texture endlessly. Our approach is demonstrated by synthesizing the long kungfu motion texture without visual artifacts, together with post-processing including our new developed graphcut-based motion blending and Poisson-based motion smoothing techniques.

  15. New, mechanically textured high-efficiency solar cells of low-cost silicon foil material. Final report; Neuartige, mechanisch texturierte Hochleistungssolarzellen aus kostenguenstigem Siliziumfolienmaterial. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bucher, E.; Fath, P.; Boueke, A.; Gerhards, C.; Huster, F.; Kuehn, R.; Hahn, G.; Terheiden, B.

    2001-07-01

    The project investigated the efficiency increase of solar cells made of multicrystalline silicon. Since 1992, Constance University has been working on a texturing process based on fast rotating profile tools. The technology is a low-cost grinding technology and will enhance the efficiency of multicrystalline Si solar cell processes in industrial applications. Combined with innovative cell concepts (semi-transparent POWER solar cells, rolling pressure metallization, innovative cell connection), the process has considerable technology transfer and marketing potential. The project intended a systematic improvement of the results achieved so far on the basis of new ideas and full exploitation of the available technological potential in the field of wafer, foil and thin film processes. [German] Zu Beginn des Vorhabens zeichnete sich weltweit der Trend ab, zunehmend multikristallines Silizium, blockgegossenes sowie foliengezogenes, in der Photovoltaik einzusetzen. Daraus ergab sich die Fragestellung der Steigerung des Solarzellenwirkungswirkungsgrades insbesondere auf diesen Materialien. Zwei wesentliche Aspekte sind dabei zu beruecksichtigen: eine effiziente Oberflaechentextur und eine angepasste Prozessoptimierung inklusive Volumenpasssivierung. Bei dem an der Universitaet Konstanz seit 1992 in der Laborentwicklung befindlichen Texturierungsverfahren auf Basis schnellrotierenden Profilwerkzeuge handelte es sich um eine vielseitig verwendbare Technologie, die zum einen als reines mechanisches Schleifverfahren kostenguenstig erscheint und zum anderen zu Wirkungsgradsteigerungen bei industrienahen multikristallinen Silizium-Solarzellenprozessen fuehrt. In Verbindung mit innovativen Zellkonzepten (semitransparente POWER-Solarzellen, Rolldruckmetallisierung, innovative Zellverschaltung) verfuegt dieses Verfahren ueber ein erhebliches Technologietransfer- und Marktpotential. Das vorliegende Vorhaben verfolgte eine systematische Verbesserung der bereits erzielten Ergebnisse

  16. Magmatic emulsion texture formed by mixing during extrusion, Rauðafell composite complex, Breiðdalur volcano, eastern Iceland

    DEFF Research Database (Denmark)

    Charreteur, Gilles; Tegner, Christian

    2013-01-01

    is the presence of antecrysts of both end-members. When the basaltic end-member represents c. 65 to 30 % of the mixture, we observe emulsion textures composed of finely comingled basalt and rhyolite. The difference between these two textural expressions of mixing is due to effects of diffusion. The third texture...... of emulsion textures is rare and highly dependent on cooling history....

  17. Transition Temperatures of Thermotropic Liquid Crystals from the Local Binary Gray Level Cooccurrence Matrix

    Directory of Open Access Journals (Sweden)

    S. Sreehari Sastry

    2012-01-01

    Full Text Available This paper presents a method which combines the statistical analysis with texture structural analysis called Local Binary Gray Level Cooccurrence Matrix (LBGLCM to investigate the phase transition temperatures of thermotropic p,n-alkyloxy benzoic acid (nOBA, n=4,6,8,10 and 12 liquid crystals. Textures of the homeotropically aligned liquid crystal compounds are recorded as a function of temperature using polarizing optical microscope attached to the hot stage and high resolution camera. In this method, second-order statistical parameters (contrast, energy, homogeneity, and correlation are extracted from the LBGLCM of the textures. The changes associatedwiththe values of extracted parameters as a function of temperature are a helpful process to identify the phases and phase transition temperatures of the samples. Results obtained from this method have validity and are in good agreement with the literature.

  18. Determination of the transition to the high entropy regime for alloys of refractory elements

    Energy Technology Data Exchange (ETDEWEB)

    Grosso, Mariela F. del [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499 (B1650KNA), San Martin (Argentina); CONICET, Buenos Aires (Argentina); Grupo de Caracterizacion y Modelizacion de Materiales, UTN, FRGP, H. Yrigoyen 288, (B1617FRG) Gral. Pacheco (Argentina); Bozzolo, Guillermo, E-mail: guille_bozzolo@yahoo.com [Loyola University Maryland, 4501 N. Charles St., Baltimore, MD 21210 (United States); Mosca, Hugo O. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499 (B1650KNA), San Martin (Argentina); Grupo de Caracterizacion y Modelizacion de Materiales, UTN, FRGP, H. Yrigoyen 288, (B1617FRG) Gral. Pacheco (Argentina)

    2012-09-05

    Highlights: Black-Right-Pointing-Pointer Atomistic modeling using a quantum approximate method for the energetics. Black-Right-Pointing-Pointer Modeling of the phase structure of high entropy alloys of refractory elements. Black-Right-Pointing-Pointer Comparison of modeled structure with experimental results for five-element alloys. Black-Right-Pointing-Pointer Determination of bulk properties of transitional chains from 4 to 5 element alloys. Black-Right-Pointing-Pointer Introduction of an algorithm to aid in the design of high entropy alloys. - Abstract: The development of high entropy alloys is currently limited to experimental work aimed at the determination of specific compositions that exhibit particular properties. The main feature of these alloys is their particular phase structure, which tends to be a continuous solid solution in spite of the large number of constituents which would otherwise form a large number of intermetallic phases. While it is known that equimolar concentrations and large number of elements are two necessary conditions for achieving high entropy behavior, not much is known regarding the transition to this regime in the presence of specific elements. Such knowledge would be useful when determining alloy compositions, as it would set boundaries for the necessary concentrations of each element in experimental situations. In this work, results of a computational modeling effort are presented, where a recently developed 5-element high entropy alloy of refractory elements is used as the foundation needed to examine such transition and determine the necessary lower bounds for the concentration of each element. Details of the phase structure of the quaternary combinations of W, Nb, Mo, Ta and V as they evolve upon the addition of a fifth element are discussed. The results are compared to the experimental case for the case of V added to W-Nb-Mo-Ta. Using these examples as a reference, the concept of critical concentrations for each element

  19. Designing Robust Hierarchically Textured Oleophobic Fabrics.

    Science.gov (United States)

    Kleingartner, Justin A; Srinivasan, Siddarth; Truong, Quoc T; Sieber, Michael; Cohen, Robert E; McKinley, Gareth H

    2015-12-08

    Commercially available woven fabrics (e.g., nylon- or PET-based fabrics) possess inherently re-entrant textures in the form of cylindrical yarns and fibers. We analyze the liquid repellency of woven and nanotextured oleophobic fabrics using a nested model with n levels of hierarchy that is constructed from modular units of cylindrical and spherical building blocks. At each level of hierarchy, the density of the topographical features is captured using a dimensionless textural parameter D(n)*. For a plain-woven mesh comprised of chemically treated fiber bundles (n = 2), the tight packing of individual fibers in each bundle (D2* ≈ 1) imposes a geometric constraint on the maximum oleophobicity that can be achieved solely by modifying the surface energy of the coating. For liquid droplets contacting such tightly bundled fabrics with modified surface energies, we show that this model predicts a lower bound on the equilibrium contact angle of θ(E) ≈ 57° below which the Cassie–Baxter to Wenzel wetting transition occurs spontaneously, and this is validated experimentally. We demonstrate how the introduction of an additional higher order micro-/nanotexture onto the fibers (n = 3) is necessary to overcome this limit and create more robustly nonwetting fabrics. Finally, we show a simple experimental realization of the enhanced oleophobicity of fabrics by depositing spherical microbeads of poly(methyl methacrylate)/fluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) onto the fibers of a commercial woven nylon fabric.

  20. Pyramidal texturing of silicon solar cell with TMAH chemical anisotropic etching

    Energy Technology Data Exchange (ETDEWEB)

    Papet, P.; Nichiporuk, O.; Kaminski, A.; Rozier, Y.; Kraiem, J.; Lelievre, J.-F.; Chaumartin, A.; Fave, A.; Lemiti, M. [Laboratoire de Physique de la Matiere, UMR-CNRS 5511, Institut National des Sciences Appliquees de Lyon, Bat Blaise Pascal, 7 avenue Jean Capelle, 69621 Villeurbanne Cedex (France)

    2006-09-22

    High-efficiency silicon solar cells need a textured front surface to reduce reflectance and to improve light trapping. Texturing of monocrystalline silicon is usually done in alkaline solutions. These solutions are cheaper, but are pollutants of silicon technologies. In this paper, we investigate an alternative solution containing tetramethyl ammonium hydroxide ((CH{sub 3}){sub 4}NOH, TMAH ). This study shows the influence of different parameters (concentration, agitation, duration and temperature), to obtain uniform and reliable pyramidal texturization on different silicon surfaces (as cut, etched and polished). Under optimized conditions, TMAH-textured surface led to an average weighted reflectance of 13%, without any antireflection coating independent of the initial silicon surface. Unlike potassium hydroxide (KOH) texturing solution, characterization of silicon oxide layer contamination after TMAH texturing process revealed no pollution, and passivation is less affected by TMAH than by KOH texturization. (author)

  1. Low-to-high confinement transition mediated by turbulence radial wave number spectral shift in a fusion plasma

    DEFF Research Database (Denmark)

    Xu, G. S.; Wan, B. N.; Wang, H. Q.;

    2016-01-01

    A new model for the low-to-high (L-H) confinement transition has been developed based on a new paradigm for turbulence suppression by velocity shear [G. M. Staebler et al., Phys. Rev. Lett.110, 055003 (2013)]. The model indicates that the L-H transition can be mediated by a shift in the radial wa...

  2. A Case of High-grade Transitional Cell Carcinoma of the Bladder in a Pediatric Patient With Turner Syndrome.

    Science.gov (United States)

    Aguiar, Liza; Danialan, Richard; Kim, Christina

    2015-06-01

    Transitional cell carcinoma is a rare entity in children, especially in the first decade of life. The majority of these tumors are of low grade and noninvasive. We report an interesting case of a high-grade superficial transitional cell carcinoma in a 3-year-old girl with Turner syndrome.

  3. Texture discrimination by Gabor functions.

    Science.gov (United States)

    Turner, M R

    1986-01-01

    A 2D Gabor filter can be realized as a sinusoidal plane wave of some frequency and orientation within a two dimensional Gaussian envelope. Its spatial extent, frequency and orientation preferences as well as bandwidths are easily controlled by the parameters used in generating the filters. However, there is an "uncertainty relation" associated with linear filters which limits the resolution simultaneously attainable in space and frequency. Daugman (1985) has determined that 2D Gabor filters are members of a class of functions achieving optimal joint resolution in the 2D space and 2D frequency domains. They have also been found to be a good model for two dimensional receptive fields of simple cells in the striate cortex (Jones 1985; Jones et al. 1985). The characteristic of optimal joint resolution in both space and frequency suggests that these filters are appropriate operators for tasks requiring simultaneous measurement in these domains. Texture discrimination is such a task. Computer application of a set of Gabor filters to a variety of textures found to be preattentively discriminable produces results in which differently textured regions are distinguished by first-order differences in the values measured by the filters. This ability to reduce the statistical complexity distinguishing differently textured region as well as the sensitivity of these filters to certain types of local features suggest that Gabor functions can act as detectors of certain "texton" types. The performance of the computer models suggests that cortical neurons with Gabor like receptive fields may be involved in preattentive texture discrimination.

  4. Bolus matters: the influence of food oral breakdown on dynamic texture perception.

    Science.gov (United States)

    Devezeaux de Lavergne, Marine; van de Velde, Fred; Stieger, Markus

    2017-02-22

    This review article focuses on design of food structure, characterisation of oral processing by boli characterisation and dynamic texture perception. Knowledge of the food properties governing bolus formation and bolus properties determining temporal changes in texture perception is of major importance. Such knowledge allows academia to better understand the mechanisms underlying texture perception and food industry to improve product texture. For instance, such knowledge can be used for developing foods with desired texture perception that fit in a healthy diet or that are customized to specific consumer groups. The end point of oral processing is the formation of a safe-to-swallow bolus. The transitions of solid and soft solid foods into bolus are accompanied by tremendous modifications of food properties. The review discusses dynamic changes in bolus properties resulting in dynamic changes of texture perception during oral processing. Studies monitoring chewing behaviour are discussed to complement the relationships between bolus properties and dynamic texture perception. We conclude that texture perception evolves over mastication time and depends on food properties, such as mechanical properties, mainly in the beginning of oral processing. Towards the middle and end of oral processing, bolus properties depend on food properties and explain texture perception better than food properties.

  5. Texture analysis of Napoleonic War Era copper bolts

    Science.gov (United States)

    Malamud, Florencia; Northover, Shirley; James, Jon; Northover, Peter; Kelleher, Joe

    2016-04-01

    Neutron diffraction techniques are suitable for volume texture analyses due to high penetration of thermal neutrons in most materials. We have implemented a new data analysis methodology that employed the spatial resolution achievable by a time-of-flight neutron strain scanner to non-destructively determine the crystallographic texture at selected locations within a macroscopic sample. The method is based on defining the orientation distribution function of the crystallites from several incomplete pole figures, and it has been implemented on ENGIN-X, a neutron strain scanner at the Isis Facility in the UK. Here, we demonstrate the application of this new texture analysis methodology in determining the crystallographic texture at selected locations within museum quality archaeological objects up to 1 m in length. The results were verified using samples of similar, but less valuable, objects by comparing the results of applying this method with those obtained using both electron backscatter diffraction and X-ray diffraction on their cross sections.

  6. Critical heat flux maxima during boiling crisis on textured surfaces

    Science.gov (United States)

    Dhillon, Navdeep Singh; Buongiorno, Jacopo; Varanasi, Kripa K.

    2015-01-01

    Enhancing the critical heat flux (CHF) of industrial boilers by surface texturing can lead to substantial energy savings and global reduction in greenhouse gas emissions, but fundamentally this phenomenon is not well understood. Prior studies on boiling crisis indicate that CHF monotonically increases with increasing texture density. Here we report on the existence of maxima in CHF enhancement at intermediate texture density using measurements on parametrically designed plain and nano-textured micropillar surfaces. Using high-speed optical and infrared imaging, we study the dynamics of dry spot heating and rewetting phenomena and reveal that the dry spot heating timescale is of the same order as that of the gravity and liquid imbibition-induced dry spot rewetting timescale. Based on these insights, we develop a coupled thermal-hydraulic model that relates CHF enhancement to rewetting of a hot dry spot on the boiling surface, thereby revealing the mechanism governing the hitherto unknown CHF enhancement maxima. PMID:26346098

  7. Phase transitions in Cd3P2 at high pressures and high temperatures

    DEFF Research Database (Denmark)

    Yel'kin, F.S.; Sidorov, V.A.; Waskowska, A.;

    2008-01-01

    The high-pressure, high-temperature structural behaviour of Cd3P2 has been studied using electrical resistance measurements, differential thermal analysis, thermo baric analysis and X-ray diffraction. At room temperature, a phase transformation is observed at 4.0 GPa in compression....... The experimental zero-pressure bulk modulus of the low-pressure phase is 64.7(7) GPa, which agrees quite well with the calculated value of 66.3 GPa using the tight-binding linear muffin-tin orbital method within the local density approximation. Tentatively, the high-pressure phase has an orthorhombic crystal...

  8. Significant improvement in Mn2O3 transition metal oxide electrical conductivity via high pressure

    Science.gov (United States)

    Hong, Fang; Yue, Binbin; Hirao, Naohisa; Liu, Zhenxian; Chen, Bin

    2017-01-01

    Highly efficient energy storage is in high demand for next-generation clean energy applications. As a promising energy storage material, the application of Mn2O3 is limited due to its poor electrical conductivity. Here, high-pressure techniques enhanced the electrical conductivity of Mn2O3 significantly. In situ synchrotron micro X-Ray diffraction, Raman spectroscopy and resistivity measurement revealed that resistivity decreased with pressure and dramatically dropped near the phase transition. At the highest pressure, resistivity reduced by five orders of magnitude and the sample showed metal-like behavior. More importantly, resistivity remained much lower than its original value, even when the pressure was fully released. This work provides a new method to enhance the electronic properties of Mn2O3 using high-pressure treatment, benefiting its applications in energy-related fields. PMID:28276479

  9. Dynamic Heterogeneity in Highly Cross-linked Epoxy in the Vicinity of Glass Transition

    Science.gov (United States)

    Lin, Po-Han; Khare, Rajesh

    2010-03-01

    Cross-linked epoxy has been widely used in aerospace and electronics industries. The highly cross-linked nature of these systems leads to different chain dynamics as compared to the linear polymeric systems. In this work, we have used molecular dynamics (MD) simulations to study the dynamic heterogeneity in cross-linked epoxy near the glass transition temperature. Well-relaxed atomistic models of cross-linked epoxy were first created by employing the simulated annealing polymerization approach. The specific epoxy system studied consisted of diglycidyl ether of bisphenol-A (DGEBA) as the epoxy monomer and trimethylene glycol di-p-aminobenzoate (TMAB) as the cross-linker. The glass transition temperature of these model structures was determined from MD simulation by monitoring their volume-temperature behaviour in a stepwise cooling run. The chain dynamics of these systems were characterized by their local translational and orientational mobility. Furthermore, dynamic heterogeneity was studied by analyzing the spatial distribution of the mobile and immobile atoms in the system near the glass transition temperature.

  10. Effects of the quark-hadron phase transition on highly magnetized neutron stars

    Science.gov (United States)

    Franzon, B.; Gomes, R. O.; Schramm, S.

    2016-11-01

    The presence of quark-hadron phase transitions in neutron stars can be related to several interesting phenomena. In particular, previous calculations have shown that fast rotating neutron stars, when subjected to a quark-hadron phase transition in their interiors, could give rise to the backbending phenomenon characterized by a spin-up era. In this work, we use an equation of state composed of two phases, containing nucleons (and leptons) and quarks. The hadronic phase is described in a relativistic mean field formalism that takes many-body forces into account, and the quark phase is described by the MIT bag model with a vector interaction. Stationary and axisymmetric stellar models are obtained in a self-consistent way by solving numerically the Einstein-Maxwell equations by means of a pseudo-spectral method. As a result, we obtain the interesting backbending phenomenon for fast spinning neutron stars. More importantly, we show that a magnetic field, which is assumed to be axisymmetric and poloidal, can also be enhanced due to the phase transition from normal hadronic matter to quark matter on highly magnetized neutron stars. Therefore, in parallel to the spin-up era, classes of neutron stars endowed with strong magnetic fields may go through a `magnetic-up era' in their lives.

  11. Identification and Plasma Diagnostics Study of Extreme Ultraviolet Transitions in Highly Charged Yttrium

    Directory of Open Access Journals (Sweden)

    Roshani Silwal

    2017-09-01

    Full Text Available Extreme ultraviolet spectra of the L-shell ions of highly charged yttrium (Y 26 + –Y 36 + were observed in the electron beam ion trap of the National Institute of Standards and Technology using a flat-field grazing-incidence spectrometer in the wavelength range of 4 nm-20 nm. The electron beam energy was systematically varied from 2.3 keV–6.0 keV to selectively produce different ionization stages. Fifty-nine spectral lines corresponding to Δ n = 0 transitions within the n = 2 and n = 3 shells have been identified using detailed collisional-radiative (CR modeling of the non-Maxwellian plasma. The uncertainties of the wavelength determinations ranged between 0.0004 nm and 0.0020 nm. Li-like resonance lines, 2s– 2 p 1 / 2 and 2s–2 p 3 / 2 , and the Na-like D lines, 3s– 3 p 1 / 2 and 3s– 3 p 3 / 2 , have been measured and compared with previous measurements and calculations. Forbidden magnetic dipole (M1 transitions were identified and analyzed for their potential applicability in plasma diagnostics using large-scale CR calculations including approximately 1.5 million transitions. Several line ratios were found to show strong dependence on electron density and, hence, may be implemented in the diagnostics of hot plasmas, in particular in fusion devices.

  12. Highly Flexible and High-Performance Complementary Inverters of Large-Area Transition Metal Dichalcogenide Monolayers

    KAUST Repository

    Pu, Jiang

    2016-03-23

    Complementary inverters constructed from large-area monolayers of WSe2 and MoS2 achieve excellent logic swings and yield an extremely high gain, large total noise margin, low power consumption, and good switching speed. Moreover, the WSe2 complementary-like inverters built on plastic substrates exhibit high mechanical stability. The results provide a path toward large-area flexible electronics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Self-structuring foods based on acid-sensitive low and high acyl mixed gellan systems to impact on satiety

    OpenAIRE

    2014-01-01

    This study investigated the in vitro acid-induced gelation of mixed systems of two biopolymers; low acyl and high acyl gellan gum. Rheological and texture analysis showed that these mixed gels displayed textures that lay between the material properties exhibited for the low and high acyl variants. DSC analysis showed that mixtures of the low acyl and high acyl forms exhibit two separate conformational transitions at temperatures coincident with each of the individual biopolymers. Various meta...

  14. Maximum entropy principle and texture formation

    CERN Document Server

    Arminjon, M; Arminjon, Mayeul; Imbault, Didier

    2006-01-01

    The macro-to-micro transition in a heterogeneous material is envisaged as the selection of a probability distribution by the Principle of Maximum Entropy (MAXENT). The material is made of constituents, e.g. given crystal orientations. Each constituent is itself made of a large number of elementary constituents. The relevant probability is the volume fraction of the elementary constituents that belong to a given constituent and undergo a given stimulus. Assuming only obvious constraints in MAXENT means describing a maximally disordered material. This is proved to have the same average stimulus in each constituent. By adding a constraint in MAXENT, a new model, potentially interesting e.g. for texture prediction, is obtained.

  15. Spinifex-textured komatiites in the south border of the Carajas ridge, Selva Greenstone belt, Carajás Province, Brazil

    Science.gov (United States)

    Siepierski, Lincoln; Ferreira Filho, Cesar Fonseca

    2016-03-01

    .%, and cumulate textured komatiites have MgO contents up to 40.6 wt.%. When plotted vs MgO contents, most major and minor elements fall on well-defined linear trends indicating control by olivine fractionation or accumulation. Komatiites from the Selva and Seringa (located in the Rio Maria Domain) belts are Al-undepleted with Al2O3/TiO2 ratios close to 20. Results for CaO, Na2O, and REE suggest that these elements were mobile and their abundances have been modified during metasomatic alteration. REE contents in some samples are very high (up to 40 times primitive mantle values) and REE patterns vary from flat (La/YbMN ∼ 1) to highly enriched in LREE (La/YbMN up to ∼ 10). The REE mobility may be related to hydrothermal alteration associated to Cu-Au mineralization in the region. The identification of spinifex-textured komatiites close to the Carajás Basin suggests the continuation of 3.0-2.9 Ga greenstone belts of the Rio Maria Domain within the Transition Subdomain, and enlarges the area with potential to host komatiite-associated Ni-Cu-PGE deposits.

  16. Phonon density of states of Sn in textured SnO under high pressure: Comparison of nuclear inelastic x-ray scattering spectra to a shell model

    Science.gov (United States)

    Giefers, H.; Koval, S.; Wortmann, G.; Sturhahn, W.; Alp, E. E.; Hu, M. Y.

    2006-09-01

    The local phonon density of states (DOS) at the Sn site in tin monoxide (SnO) is studied at pressures up to 8GPa with Sn119 nuclear resonant inelastic x-ray scattering (NRIXS) of synchrotron radiation at 23.88keV . The preferred orientation (texture) of the SnO crystallites in the investigated samples is used to measure NRIXS spectra preferentially parallel and almost perpendicular to the c axis of tetragonal SnO . A subtraction method is applied to these NRIXS spectra to produce projected local Sn DOS spectra as seen parallel and perpendicular to the c axis of SnO . These experimentally obtained local Sn DOS spectra, both in the polycrystalline case as well as projected parallel and perpendicular to the c axis, are compared with corresponding theoretical phonon DOS spectra, derived from dispersion relations calculated with a recently developed shell model. Comparison between the experimental projected Sn DOS spectra and the corresponding theoretical DOS spectra enables us to follow the pressure-induced shifts of several acoustic and optic phonon modes. While the principal spectral features of the experimental and theoretical phonon DOS agree well at energies above 10meV , the pressure behavior of the low-energy part of the DOS is not well reproduced by the theoretical calculations. In fact, they exhibit, in contrast to the experimental data, a dramatic softening of two low-energy modes, their energies approaching zero around 2.5GPa , clearly indicating the limitations of the applied shell model. These difficulties are obviously connected with the complex Sn-O and Sn-Sn bindings within and between the Sn-O-Sn layers in the litharge structure of SnO . We derived from the experimental and theoretical DOS spectra a variety of elastic and thermodynamic parameters of the Sn sublattice, such as the Lamb-Mössbauer factor, the mean force constant, and Debye temperatures, as well as the vibrational contributions to the Helmholtz free energy, specific heat, entropy, and

  17. Insights into the water mean transit time in a high-elevation tropical ecosystem

    Science.gov (United States)

    Mosquera, Giovanny M.; Segura, Catalina; Vaché, Kellie B.; Windhorst, David; Breuer, Lutz; Crespo, Patricio

    2016-07-01

    This study focuses on the investigation of the mean transit time (MTT) of water and its spatial variability in a tropical high-elevation ecosystem (wet Andean páramo). The study site is the Zhurucay River Ecohydrological Observatory (7.53 km2) located in southern Ecuador. A lumped parameter model considering five transit time distribution (TTD) functions was used to estimate MTTs under steady-state conditions (i.e., baseflow MTT). We used a unique data set of the δ18O isotopic composition of rainfall and streamflow water samples collected for 3 years (May 2011 to May 2014) in a nested monitoring system of streams. Linear regression between MTT and landscape (soil and vegetation cover, geology, and topography) and hydrometric (runoff coefficient and specific discharge rates) variables was used to explore controls on MTT variability, as well as mean electrical conductivity (MEC) as a possible proxy for MTT. Results revealed that the exponential TTD function best describes the hydrology of the site, indicating a relatively simple transition from rainfall water to the streams through the organic horizon of the wet páramo soils. MTT of the streams is relatively short (0.15-0.73 years, 53-264 days). Regression analysis revealed a negative correlation between the catchment's average slope and MTT (R2 = 0.78, p < 0.05). MTT showed no significant correlation with hydrometric variables, whereas MEC increases with MTT (R2 = 0.89, p < 0.001). Overall, we conclude that (1) baseflow MTT confirms that the hydrology of the ecosystem is dominated by shallow subsurface flow; (2) the interplay between the high storage capacity of the wet páramo soils and the slope of the catchments provides the ecosystem with high regulation capacity; and (3) MEC is an efficient predictor of MTT variability in this system of catchments with relatively homogeneous geology.

  18. BREAD CRUMBS TEXTURE OF SPELT

    Directory of Open Access Journals (Sweden)

    Joanna Korczyk – Szabó

    2014-02-01

    Full Text Available Texture analysis is an objective physical examination of baked products and gives direct information on the product quality, oppositely to dough rheology tests what inform on the baking suitability of the flour, as raw material. Evaluation of the mechanical properties of bread crumb is important not only for quality assurance in the bakeries, but also for assessing the effects of changes in dough ingredients and processing condition and also for describing the changes in bread crumb during storage. Crumb cellular structure is an important quality criterion used in commercial baking and research laboratories to judge bread quality alongside taste, crumb colour and crumb physical texture. In the framework of our research during the years 2010 – 2011 were analyzed selected indicators of bread crumb for texture quality of three Triticum spelta L. cultivars – Altgold, Rubiota and Ostro grown in an ecological system. The bread texture quality was evaluated on texture analyzer TA.XT Plus (Stable Micro Systems, Surrey, UK, following the AACC (74-09 standard and expressed as crumb firmness (N, stiffness (N.mm-1 and relative elasticity (%. Our research proved that all selected indicators were significantly influenced by the year of growing and variety. The most soft bread was achieved in Rubiota, whereas bread crumb samples from Altgold and Ostro were the most firm and stiff. Correlation analysis showed strong negative correlation between relative elasticity and bread crumb firmness as well as bread stiffness (-0.65++, -0.66++. The spelt wheat bread crumb texture need further investigation as it can be a reliable quality parameter.

  19. High frequency microphone measurements for transition detection on airfoils. NACA-0015 appendix report

    DEFF Research Database (Denmark)

    Døssing, Mads

    Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given...... pressure) and Tollmien-Schlichting frequencies. The tests were made at Reynolds and Mach numbers corresponding to the operating conditions of a typical horizontal axis wind turbine (HAWT). The Risø B1-18, Risø C2-18 and NACA0015 profiles were tested and the measured transition points are reported....

  20. A Simple System to Measure Superconducting Transition Temperature at High Pressure

    Institute of Scientific and Technical Information of China (English)

    YU Yong; ZHAI Guang-Jie; JIN Chang-Qing

    2009-01-01

    A simple hydride system is fabricated to measure the superconducting transition temperature Tc under high pressure using a diamond anvil cell (DAC). The system is designed with centrosymetric coils around the diamond that makes it easy to keep balance between the pick-up coil and the inductance coil, while the superconducting states can be modulated with a low-frequency small external magnetic field. Using the device we successfully obtain the Tc evolution as a function of applied pressure up to 10 GPa for YBa2 Cu3O6+δ superconductor single crystal.

  1. Circular dichroism in free-free transitions of high energy electron-atom scattering

    CERN Document Server

    Cionga, Aurelia; Zloh, Gabriela; 10.1103/PhysRevA.62.063406

    2013-01-01

    We consider high energy electron scattering by hydrogen atoms in the presence of a laser field of moderate power and higher frequencies. If the field is a superposition of a linearly and a circularly polarized laser beam in a particular configuration, then we can show that circular dichroism in two photon transitions can be observed not only for the differential but also for the integrated cross sections, provided the laser-dressing of the atomic target is treated in second order perturbation theory and the coupling between hydrogenic bound and continuum states is involved.

  2. Momentum-space spin texture in a topological superconductor

    Science.gov (United States)

    Loder, Florian; Kampf, Arno P.; Kopp, Thilo; Braak, Daniel

    2017-07-01

    A conventional superconductor with spin-orbit coupling turns into a topological superconductor beyond a critical strength of the Zeeman energy. The spin-expectation values S (k ) in momentum space trace this transition via a characteristic change in the topological character of the spin texture within the Brillouin zone. At the transition the skyrmion counting number switches from 0 to 1/2 identifying the topological superconductor via its meron-like spin texture. The change in the skyrmion counting number is crucially controlled by singular points of the map S (k )/|S (k )| from the Brillouin zone, i.e., a torus, to the unit sphere. The complexity of this spin map is discussed at zero temperature as well as for the extension to finite temperatures.

  3. Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)

    CERN Document Server

    Tennyson, Jonathan; Campargue, Alain; Csaszar, Attila G; Daumont, Ludovic; Gamache, Robert R; Hodges, Joseph T; Lisak, Daniel; Naumenko, Olga V; Rothman, Laurence S; Tran, Ha; Zobov, Nikolai F; Buldyreva, Jeanna; Boone, Chris D; De Vizia, Maria Domenica; Gianfrani, Livio; Hartmann, Jean-Michel; McPheat, Robert; Murray, Jonathan; Ngo, Ngoc Hoa; Polyansky, Oleg L; Weidmann, Damien

    2014-01-01

    The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should b...

  4. Nanosecond Ultrasonics to Study Phase Transitions in Solid and Liquid Systems at High Pressure and Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B P; Berge, P A; Carlson, S C; Farber, D L; Akella, J

    2007-03-21

    This report describes the development of a high-frequency ultrasonic measurement capability for application to the study of phase transitions at elevated pressure and temperature. We combined expertise in various aspects of static high-pressure technique with recent advances in wave propagation modeling, ultrasonic transducer development, electronic methods and broadband instrumentation to accomplish the goals of this project. The transduction and electronic systems have a demonstrated bandwidth of 400 MHz, allowing investigations of phenomena with characteristic times as short as 2.5 nS. A compact, pneumatically driven moissanite anvil cell was developed and constructed for this project. This device generates a high-pressure environment for mm dimension samples to pressures of 3 GPa. Ultrasonic measurements were conducted in the moissanite cell, an LLNL multi-anvil device and in a modified piston cylinder device. Measurements for water, and elemental tantalum, tin and cerium demonstrate the success of the methods. The {gamma}-{alpha} phase transition in cerium was clearly detected at {approx}0.7 GPa with 75 MHz longitudinal waves. These results have direct application to important problems in LLNL programs, as well as seismology and planetary science.

  5. Very high thermoelectric figure of merit found in hybrid transition-metal-dichalcogenides

    Science.gov (United States)

    Ouyang, Yulou; Xie, Yuee; Zhang, Zhongwei; Peng, Qing; Chen, Yuanping

    2016-12-01

    The search for thermoelectrics with higher figures of merit (ZT) will never stop due to the demand of heat harvesting. Single layer transition metal dichalcogenides (TMD), namely, MX2 (where M is a transition metal and X is a chalcogen), that have electronic band gaps are among the new materials that have been the focus of such research. Here, we investigate the thermoelectric transport properties of hybrid armchair-edged TMD nanoribbons, by using the nonequilibrium Green's function technique combined with the first principles and molecular dynamics methods. We find a ZT as high as 7.4 in hybrid MoS2/MoSe2 nanoribbons at 800 K, creating a new record for ZT. Moreover, the hybrid interfaces by substituting X atoms are more efficient than those by substituting M atoms to tune the ZT. The origin of such a high ZT of hybrid nanoribbons is the high density of the grain boundaries: the hybrid interfaces decrease thermal conductance drastically without a large penalty to electronic conductance.

  6. KOI-1299 b: a massive planet in a highly eccentric orbit transiting a red giant

    CERN Document Server

    Ciceri, Simona; Southworth, John; Mancini, Luigi; Henning, Thomas; Barrado, David

    2014-01-01

    We confirm the planetary nature of the Kepler object of interest KOI-1299 b. We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By a simultaneous fit of these new data and Kepler photometry, we found that KOI-1299 b is a dense transiting exoplanet, having a mass of Mp = 4.87 +/- 0.48 MJup and radius of Rp = 1.120 +/- 0.036 RJup. The planet revolves around a K giant star, ascending the red giant branch, every 52.5 d, moving on a highly eccentric orbit with e = 0.535 +/- 0.030. By analysing two NIR high-resolution images, we found that a star occurs at 1.1 from KOI-1299, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, KOI-1299 occupies an almost-desert region of parameter space, which is important to constrain the evolutionary processes of planetary systems.

  7. Integrated High-Rate Transition Radiation Detector and Tracking Chamber for the LHC

    CERN Multimedia

    2002-01-01

    % RD-6 \\\\ \\\\Over the past five years, RD-6 has developed a transition radiation detector and charged particle tracker for high rate operation at LHC. The detector elements are based on C-fibre reinforced kapton straw tubes of 4~mm diameter filled with a Xenon gas mixture. Detailed measurements with and without magnetic field have been performed in test beams, and in particular have demonstrated the possibility of operating straw tubes at very high rate (up to 20~MHz) with accurate drift-time measurement accuracy. A full-scale engineering prototype containing 10~000 straws is presently under assembly and will be accurately measured with a powerful X-ray tube. Integrated front-end electronics with fast readout have been designed and successfully operated in test beam. \\\\ \\\\Finally extensive simulations performed for ATLAS have shown that such a detector will provide powerful pattern recognition, accurate momentum measurements, efficient level-2 triggering and excellent electron identification, even at the highe...

  8. High pressure effect on structural transition of Fe cluster during rapid quenching processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Molecular dynamics simulations of 21,952 atoms have been performed to study local structure evolution and glass formation in iron melts rapidly cooled under high pressures.In the quenching processes,structural transition details have been analyzed by using the radial distribution function g(r) and bond pair analysis technique.It is shown that high pressure strengthens the order degree of the glass system and favors the glass formation.That means with the increase of pressures,a more compacted local structure with more ideal icosahedra can be obtained.The calculations of free volume of the system indicate that the decrease of the number of the defected ideal icosahedra under high pressure contributes to the glass formation of Fe.

  9. Stress management with adolescents at the junior high transition: an outcome evaluation of coping skills intervention.

    Science.gov (United States)

    Schinke, S P; Schilling, R F; Snow, W H

    1987-01-01

    This paper reports an outcome study of coping skills intervention to help adolescents manage stress associated with the transition from elementary school to junior high. In a randomized design, sixth grade students from four elementary schools were pretested, then two schools each were assigned to an intervention condition and to a control condition. Intervention condition subjects received eight sessions of instruction and practice in coping skills intervention. Following intervention, all subjects were posttested. At posttest and relative to control condition subjects, intervention condition subjects scored more positively on measures of problem solving, assertive direct refusals, adequacy of information about junior high school, ability to handle stress, ability to deal with peer pressure, and general readiness for junior high school.

  10. High-latitude ocean ventilation and its role in Earth's climate transitions.

    Science.gov (United States)

    Naveira Garabato, Alberto C; MacGilchrist, Graeme A; Brown, Peter J; Evans, D Gwyn; Meijers, Andrew J S; Zika, Jan D

    2017-09-13

    The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Authors.

  11. Transition-Metal-Free Highly Efficient Aerobic Oxidation of Sulfides to Sulfoxides under Mild Conditions

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    2009-12-01

    Full Text Available A highly efficient transition-metal-free catalytic system Br2/NaNO2/H2O has been developed for a robust and economic acid-free aerobic oxidation of sulfides. It is noteworthy that the sulfide function reacts under mild conditions without over-oxidation to sulfone. The role of NaNO2as an efficient NO equivalent for the activation of molecular oxygen was identified. Under the optimal conditions, a broad range of sulfide substrates were converted into their corresponding sulfoxides in high yields by molecular oxygen. The present catalytic system utilizes cheap and readily available agents as the catalysts, exhibits high selectivity for sulfoxide products and releases only innocuous water as the by-products.

  12. Deformation texture evolution of pure aluminum sheet under electromagnetic bulging

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi-Gang; Li, Ning; Jiang, Hua-Wen; Xiong, Yuan-Yuan; Liu, Lin, E-mail: lliu2000@mail.hust.edu.cn

    2014-03-15

    Highlights: • Pure Al sheet was deformed by electromagnetic bulging at strain rate over 10{sup 3} s{sup −1}. • Texture evolution shows a function of strain path and high strain rate. • Goss and Rotated Goss finally tend to stabilize at P texture for strain path effect. • The mean intra-granular misorientations increase along the function of strain path. • Extra path of texture evolution for enhanced cross slip activity at high strain rate. -- Abstract: The deformation texture and microstructure evolution in pure aluminum sheet after electromagnetic bulging was investigated in detail by using electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) techniques. It was found that the textural and microstructural developments were correlated with the complex strain path and the high strain rate. Stress–strain states from approximate uniaxial tension, non-equibiaxial tension to equibiaxial tension were experienced in the formed conical-shape workpiece along with the increasing strain ratio (i.e., the ratio between minor strain and major strain, representing the strain path of the formed workpiece). The grain orientation and distribution of boundary misorientation were found to be a function of the strain ratio, especially for the texture evolution in volume fraction of 〈1 1 0〉 fiber. A specific orientation with high Taylor factor, Rotated Goss 〈1 1 0〉, was observed and analyzed in terms of the contribution of preferable stress–strain state from the complex strain path and the assistance of high strain rate, which could increase the cross-slip activity, and eventually facilitate the texture development and induce more uniform microstructure.

  13. Phase Transition and EOS of Cinnabar (α-HgS) at High Pressure and High Temperature

    Institute of Scientific and Technical Information of China (English)

    FAN Da-Wei; ZHOU Wen-Ge; LIU Cong-Qiang; WAN Fang; XING Yin-Suo; LIU Jing; LI Yan-Chun; XIE Hong-Sen

    2009-01-01

    @@ Phase relations and equation of state (EOS) of natural cinnabar (α-HgS) are investigated by high-pressure and high-temperature synchrotron x-ray powder diffraction. The unambiguous cinnabar-rocksalt structure phase boundaries are determined to be Plower(Gpa)=15.54-0.014T(℃) and Pupper(Gpa)= 23.84 - 0.014T(℃) at 300--623K. With K' axed at 4, we obtain K0 = 37(4) Gpa, ( K/ T)p=-0.025(2) GPaK-1, and α0= 3.79(20)× 10-5 K-1 for the cinnabar phase of α-HgS. The ( K/ T)p and α0 of cinnabar phase are obtained for the first time. A nearly isotropic compression of cinnabar phase is observed by linear regressions.

  14. A high-resolution chronology of rapid forest transitions following polynesian arrival in New Zealand.

    Science.gov (United States)

    McWethy, David B; Wilmshurst, Janet M; Whitlock, Cathy; Wood, Jamie R; McGlone, Matt S

    2014-01-01

    Human-caused forest transitions are documented worldwide, especially during periods when land use by dense agriculturally-based populations intensified. However, the rate at which prehistoric human activities led to permanent deforestation is poorly resolved. In the South Island, New Zealand, the arrival of Polynesians c. 750 years ago resulted in dramatic forest loss and conversion of nearly half of native forests to open vegetation. This transformation, termed the Initial Burning Period, is documented in pollen and charcoal records, but its speed has been poorly constrained. High-resolution chronologies developed with a series of AMS radiocarbon dates from two lake sediment cores suggest the shift from forest to shrubland occurred within decades rather than centuries at drier sites. We examine two sites representing extreme examples of the magnitude of human impacts: a drier site that was inherently more vulnerable to human-set fires and a wetter, less burnable site. The astonishing rate of deforestation at the hands of small transient populations resulted from the intrinsic vulnerability of the native flora to fire and from positive feedbacks in post-fire vegetation recovery that increased landscape flammability. Spatially targeting burning in highly-flammable seral vegetation in forests rarely experiencing fire was sufficient to create an alternate fire-prone stable state. The New Zealand example illustrates how seemingly stable forest ecosystems can experience rapid and permanent conversions. Forest loss in New Zealand is among the fastest ecological transitions documented in the Holocene; yet equally rapid transitions can be expected in present-day regions wherever positive feedbacks support alternate fire-inhibiting, fire-prone stable states.

  15. A high-resolution chronology of rapid forest transitions following polynesian arrival in New Zealand.

    Directory of Open Access Journals (Sweden)

    David B McWethy

    Full Text Available Human-caused forest transitions are documented worldwide, especially during periods when land use by dense agriculturally-based populations intensified. However, the rate at which prehistoric human activities led to permanent deforestation is poorly resolved. In the South Island, New Zealand, the arrival of Polynesians c. 750 years ago resulted in dramatic forest loss and conversion of nearly half of native forests to open vegetation. This transformation, termed the Initial Burning Period, is documented in pollen and charcoal records, but its speed has been poorly constrained. High-resolution chronologies developed with a series of AMS radiocarbon dates from two lake sediment cores suggest the shift from forest to shrubland occurred within decades rather than centuries at drier sites. We examine two sites representing extreme examples of the magnitude of human impacts: a drier site that was inherently more vulnerable to human-set fires and a wetter, less burnable site. The astonishing rate of deforestation at the hands of small transient populations resulted from the intrinsic vulnerability of the native flora to fire and from positive feedbacks in post-fire vegetation recovery that increased landscape flammability. Spatially targeting burning in highly-flammable seral vegetation in forests rarely experiencing fire was sufficient to create an alternate fire-prone stable state. The New Zealand example illustrates how seemingly stable forest ecosystems can experience rapid and permanent conversions. Forest loss in New Zealand is among the fastest ecological transitions documented in the Holocene; yet equally rapid transitions can be expected in present-day regions wherever positive feedbacks support alternate fire-inhibiting, fire-prone stable states.

  16. Characterization of the K2-19 Multiple-Transiting Planetary System via High-Dispersion Spectroscopy, AO Imaging, and Transit Timing Variations

    CERN Document Server

    Narita, Norio; Fukui, Akihiko; Hori, Yasunori; Sanchis-Ojeda, Roberto; Winn, Joshua N; Ryu, Tsuguru; Kusakabe, Nobuhiko; Kudo, Tomoyuki; Onitsuka, Masahiro; Delrez, Laetitia; Gillon, Michael; Jehin, Emmanuel; McCormac, James; Holman, Matthew; Izumiura, Hideyuki; Takeda, Yoichi; Tamura, Motohide; Yanagisawa, Kenshi

    2015-01-01

    K2-19 (EPIC201505350) is a unique planetary system in which two transiting planets with radii ~ 7 $R_{Earth}$ (inner planet b) and ~ 4 $R_{Earth}$ (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2m telescope. We find that the host star is relatively old (>8 Gyr) late G-type star ($T_{eff}$ ~ 5350 K, $M_s$ ~ 0.9 $M_{Sun}$, and $R_{s}$ ~ 0.9 $R_{Sun}$). We do not find any contaminating faint objects near the host star which could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2m telescope, TRAPPISTCAM on the TRAPPIST 0.6m telescope, and MuSCAT on the OAO 1.88m telescope. We confirm the presence of transit-timing variations, as previously re...

  17. Validation of CBCT for the computation of textural biomarkers

    Science.gov (United States)

    Paniagua, Beatriz; Ruellas, Antonio C.; Benavides, Erika; Marron, Steve; Wolford, Larry; Cevidanes, Lucia

    2015-03-01

    Osteoarthritis (OA) is associated with significant pain and 42.6% of patients with TMJ disorders present with evidence of TMJ OA. However, OA diagnosis and treatment remain controversial, since there are no clear symptoms of the disease. The subchondral bone in the TMJ is believed to play a major role in the progression of OA. We hypothesize that the textural imaging biomarkers computed in high resolution Conebeam CT (hr- CBCT) and μCT scans are comparable. The purpose of this study is to test the feasibility of computing textural imaging biomarkers in-vivo using hr-CBCT, compared to those computed in μCT scans as our Gold Standard. Specimens of condylar bones obtained from condylectomies were scanned using μCT and hr- CBCT. Nine different textural imaging biomarkers (four co-occurrence features and five run-length features) from each pair of μCT and hr-CBCT were computed and compared. Pearson correlation coefficients were computed to compare textural biomarkers values of μCT and hr-CBCT. Four of the nine computed textural biomarkers showed a strong positive correlation between biomarkers computed in μCT and hr-CBCT. Higher correlations in Energy and Contrast, and in GLN (grey-level non-uniformity) and RLN (run length non-uniformity) indicate quantitative texture features can be computed reliably in hr-CBCT, when compared with μCT. The textural imaging biomarkers computed in-vivo hr-CBCT have captured the structure, patterns, contrast between neighboring regions and uniformity of healthy and/or pathologic subchondral bone. The ability to quantify bone texture non-invasively now makes it possible to evaluate the progression of subchondral bone alterations, in TMJ OA.

  18. Phase transition studies of the exsoluted ilmenite-hematite at high pressure and temperature conditions

    Science.gov (United States)

    Kim, Y.; Secco, R.; Hwang, G.; Bao, X.; Ming, L.

    2011-12-01

    Ilmenite minerals found in Switzerland Alpe Arami peridotite massif indicate that these precipitates are metastable phases converted from the single perovskite phase during the ascending process in the mantle. After this work, lots of subsequent high pressure-temperature experiments on ilmenite itself and its solid solution phases were performed to check the phase boundary from the starting phase to perovskite structure. This study also aims to identify the phase transition sequence(s) of the exsoluted ilmenite-hematite specimen where its locality is the Allard Lake area, Quebac, Canada, under high pressure and high temperature conditions. Bulky ore sample consists of 76.2% ilmenite and 23.8% hematite in volume. Chemistry of ilmenite is Fe1.02Mg0.13Ti0.92O3 and that of hematite, Fe2O3. Lattice parameters of ilmenite are a=5.08287(2)Å, c=14.0511(1)Å, and those of hematite a=5.04378(4)Å, c=13.7757(2)Å. Walker-type large volume multi anvil cell was employed for high pressure and high temperature experiment up to 14GPa and 2400K, respectively. Recovered samples after high pressure-temperature treatment were subjected to identify the product phase(s) by the general area detector x-ray diffraction method with conventional x-radiation as well as the x-ray micro-diffraction technique using synchrotron radiation. Phase transition sequences observed are the followings: starting exsoluted ilmenite-hematite phase transforms to the single phase of perovskite, then this perovskite phase disproportionate into various kind of oxides. Phase boundaries to perovskite, then to oxides were determined to be P(GPa)=31.8 - 0.0178T(K), and P(GPa)=23.8 - 0.0072T(K), respectively. Present result is different from the previous reports of Syono et al. (1980)(i.e., P(GPa)=25.2 - 0.01T(K)) and Ming et al. (2006)(i.e., P(GPa)=16.0 - 0.0012T(K)). Based on the present results applied to the Alpe Arami peridotite massif, source region would be much shallower part at the upper mantle(i.e., 240km

  19. X-ray resonant photoexcitation: line widths and energies of K{\\alpha} transitions in highly charged Fe ions

    CERN Document Server

    Rudolph, J K; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H -C; Yavas, H; Ullrich, J; López-Urrutia, J R Crespo

    2013-01-01

    Photoabsorption by and fluorescence of the K{\\alpha} transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main K{\\alpha} transitions in highly charged iron ions from heliumlike to fluorinelike (Fe 24+...17+) using monochromatic X-rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in X-ray binaries and active galactic nuclei.

  20. Predicting the Crystal Structure and Phase Transitions in High-Entropy Alloys

    Science.gov (United States)

    King, D. M.; Middleburgh, S. C.; Edwards, L.; Lumpkin, G. R.; Cortie, M.

    2015-06-01

    High-entropy alloys (HEAs) have advantageous properties compared with other systems as a result of their chemistry and crystal structure. The transition between a face-centered cubic (FCC) and body-centered cubic (BCC) structure in the Al x CoCrFeNi high-entropy alloy system has been investigated on the atomic scale in this work. The Al x CoCrFeNi system, as well as being a useful system itself, can also be considered a model HEA material. Ordering in the FCC structure was investigated, and an order-disorder transition was predicted at ~600 K. It was found that, at low temperatures, an ordered lattice is favored over a truly random lattice. The fully disordered BCC structure was found to be unstable. When partial ordering was imposed (lowering the symmetry), with Al and Ni limited specific sites of the BCC system, the BCC packing was stabilized. Decomposition of the ordered BCC single phase into a dual phase (Al-Ni rich and Fe-Cr rich) is also considered.

  1. High-pressure structural phase transitions in chromium-doped BaFe2As2

    Energy Technology Data Exchange (ETDEWEB)

    Uhoya, Walter [University of Alabama, Birmingham; Brill, Joseph W. [University of Kentucky; Montgomery, Jeffrey M [University of Alabama, Birmingham; Samudrala, G K [University of Alabama, Birmingham; Tsoi, Georgiy [University of Alabama, Birmingham; Vohra, Y. K. [University of Alabama, Birmingham; Weir, S. T. [Lawrence Livermore National Laboratory (LLNL); Safa-Sefat, Athena [ORNL

    2012-01-01

    We report on the results from high pressure x-ray powder diffraction and electrical resistance measurements for hole doped BaFe{sub 2-x}Cr{sub x}As{sub 2} (x = 0, 0.05, 0.15, 0.4, 0.61) up to 81 GPa and down to 10 K using a synchrotron source and diamond anvil cell (DAC). At ambient temperature, an isostructural phase transition from a tetragonal (T) phase (I4/mmm) to a collapsed tetragonal (CT) phase is observed at 17 GPa. This transition is found to be dependent on ambient pressure unit cell volume and is slightly shifted to higher pressure upon increase in the Cr-doping. Unlike BaFe{sub 2}As{sub 2} which superconduct under high pressure, we have not detected any evidence of pressure induced superconductivity in chromium doped samples in the pressure and temperature range of this study. The measured equation of state parameters are presented for both the tetragonal and collapsed tetragonal phases for x = 0.05, 0.15, 0.40 and 0.61.

  2. First-principles prediction of new complex transition metal hydrides for high temperature applications.

    Science.gov (United States)

    Nicholson, Kelly M; Sholl, David S

    2014-11-17

    Metal hydrides with high thermodynamic stability are desirable for high-temperature applications, such as those that require high hydrogen release temperatures or low hydrogen overpressures. First-principles calculations have been used previously to identify complex transition metal hydrides (CTMHs) for high temperature use by screening materials with experimentally known structures. Here, we extend our previous screening of CTMHs with a library of 149 proposed materials based on known prototype structures and charge balancing rules. These proposed materials are typically related to known materials by cation substitution. Our semiautomated, high-throughput screening uses density functional theory (DFT) and grand canonical linear programming (GCLP) methods to compute thermodynamic properties and phase diagrams: 81 of the 149 materials are found to be thermodynamically stable. We identified seven proposed materials that release hydrogen at higher temperatures than the associated binary hydrides and at high temperature, T > 1000 K, for 1 bar H2 overpressure. Our results indicate that there are many novel CTMH compounds that are thermodynamically stable, and the computed thermodynamic data and phase diagrams should be useful for selecting materials and operating parameters for high temperature metal hydride applications.

  3. Fabrication of a Textured Non-Magnetic Ni-12at.%V Alloy Substrate for Coated Conductors

    DEFF Research Database (Denmark)

    Gao, M. M.; Grivel, Jean-Claude; Suo, H. L.;

    2011-01-01

    Ni-12at.%V alloy is a promising candidate for non-magnetic cube textured metallic substrates used for high temperature coated conductors. In this work, a textured Ni-12at.%V substrate has been fabricated by powder metallurgy route. After cold rolling and recrystallization annealing, a cube texture...

  4. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Köster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19-60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  5. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Koster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19¿60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  6. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, T. van; Aken, G.A. van; Jongh, H.H.J. de; Hamer, R.J.

    2009-01-01

    Recently, considerable attention has been given to the understanding of texture attributes that cannot directly be related to physical properties of food, such as creamy, crumbly and watery. The perception of these attributes is strongly related to the way the food is processed during food intake, m

  7. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, van T.

    2010-01-01

    The perception of complex textures in food is strongly related to the way food is processed during eating, and is modulated by other basic characteristics, such as taste and aroma. An understanding at the colloidal level of the basic processes in the mouth is essential in order to link the compositi

  8. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, T. van; Aken, G.A. van; Jongh, H.H.J. de; Hamer, R.J.

    2009-01-01

    Recently, considerable attention has been given to the understanding of texture attributes that cannot directly be related to physical properties of food, such as creamy, crumbly and watery. The perception of these attributes is strongly related to the way the food is processed during food intake,

  9. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Köster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19-60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  10. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Koster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19¿60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  11. Characterization of Urban Landscape Using Super-Resolution UAS Data, Multiple Textural Scales and Data-Mining Techniques

    Science.gov (United States)

    Voss, M.; Blundell, B.

    2015-12-01

    Characterization of urban environments is a high priority for the U.S. Army as battlespaces have transitioned from the predominantly open spaces of the 20th century to urban areas where soldiers have reduced situational awareness due to the diversity and density of their surroundings. Creating high-resolution urban terrain geospatial information will improve mission planning and soldier effectiveness. In this effort, super-resolution true-color imagery was collected with an Altivan NOVA unmanned aerial system over the Muscatatuck Urban Training Center near Butlerville, Indiana on September 16, 2014. Multispectral texture analysis using different algorithms was conducted for urban surface characterization at a variety of scales. Training samples extracted from the true-color and texture images. These data were processed using a variety of meta-algorithms with a decision tree classifier to create a high-resolution urban features map. In addition to improving accuracy over traditional image classification methods, this technique allowed the determination of the most significant textural scales in creating urban terrain maps for tactical exploitation.

  12. In situ X-ray observation of phase transitions in ZnF2 under high pressure and high temperature

    Science.gov (United States)

    Kusaba, Keiji; Kikegawa, Takumi

    2008-02-01

    High-pressure and high-temperature behavior of ZnF 2 with the rutile-type structure was investigated using an energy-dispersive-type X-ray diffraction method. Two high-pressure phases were found in the range up to 15 GPa and 400 ∘C. The CaCl 2-type phase with an orthorhombic cell (space group: Pnnm) was clearly observed at 5.4 GPa and 400 ∘C. Further phase transition was induced above 10 GPa at room temperature. The single phase of the high-pressure phase was obtained at 15.3 GPa and 350 ∘C. The high-pressure phase was found to have the PdF 2-type structure with a cubic cell (space group: Pa-3). The single phase was observed above 4 GPa in a pressure-release process at room temperature, and completely reverted to a mixture of the rutile-type phase and the α- PbO 2-type phase at ambient condition. The high-pressure behavior of ZnF 2 was similar to that of MgF 2.

  13. High resolution N2 adsorption isotherms at 77.4 K and 87.3 K by carbon blacks and activated carbon fibers--analysis of porous texture of activated carbon fibers by αs-method.

    Science.gov (United States)

    Nakai, Kazuyuki; Nakada, Yoko; Hakuman, Masako; Yoshida, Masayuki; Senda, Yousuke; Tateishi, Yuko; Sonoda, Joji; Naono, Hiromitsu

    2012-02-01

    The standard α(s)-data of N(2) at 87.3 K by graphitized and nongraphitized carbon black samples (GCB-I and NGCB) (cf.Figs. 3 and 4) have been determined on the basis of the high resolution adsorption isotherms of N(2) at 87.3 K, which were repeatedly measured in the pressure range of p/p(o)=5×10(-8)-0.4. The high resolution adsorption isotherms of N(2) by two kinds of activated carbon fibers (ACF-I and ACF-II) were measured from p/p(o)=10(-7) to p/p(o)=0.995 at 77.4 K and from p/p(o)=10(-7) to p/p(o)=0.4 at 87.3 K. Combination of the adsorption isotherms by ACF-I and ACF-II with the standard α(s)-data by NGCB at 77.4 K and 87.3 K make it possible to construct the high resolution α(s)-plots from very low filling (1%) to complete filling (100%). The high resolution α(s)-plots of N(2) at 77.4 K and 87.3 K were analyzed. On the basis of the analyzed result, the porous textures of ACF-I and ACF-II will be discussed.

  14. High magnetic field studies of the hidden order transition in URu2Si2.

    Science.gov (United States)

    Jaime, M; Kim, K H; Jorge, G; McCall, S; Mydosh, J A

    2002-12-31

    We studied in detail the low temperature/high magnetic field phases of URu2Si2 single crystals with specific heat, magnetocaloric effect, and magnetoresistance in magnetic fields up to 45 T. Data obtained down to 0.5 K, and extrapolated to T=0, show a suppression of the hidden-order phase at H0(0)=35.9+/-0.35 T and the appearance of a new phase for magnetic fields in excess of H1(0)=36.1+/-0.35 T observed only at temperatures lower than 6 K. In turn, complete suppression of this high field state is attained at a critical magnetic field H2(0)=39.7+/-0.35 T. No phase transitions are observed above 40 T. We discuss our results in the context of itinerant versus localized f electrons.

  15. High Speed Pump-Probe Apparatus for Observation of Transitional Effects in Ultrafast Laser Micromachining Processes

    Directory of Open Access Journals (Sweden)

    Ilya Alexeev

    2015-12-01

    Full Text Available A pump-probe experimental approach has been shown to be a very efficient tool for the observation and analysis of various laser matter interaction effects. In those setups, synchronized laser pulses are used to create an event (pump and to simultaneously observe it (probe. In general, the physical effects that can be investigated with such an apparatus are restricted by the temporal resolution of the probe pulse and the observation window. The latter can be greatly extended by adjusting the pump-probe time delay under the assumption that the interaction process remains fairly reproducible. Unfortunately, this assumption becomes invalid in the case of high-repetition-rate ultrafast laser material processing, where the irradiation history strongly affects the ongoing interaction process. In this contribution, the authors present an extension of the pump-probe setup that allows to investigate transitional and dynamic effects present during ultrafast laser machining performed at high pulse repetition frequencies.

  16. Transition metal complexes on mesoporous silica nanoparticles as highly efficient catalysts for epoxidation of styrene.

    Science.gov (United States)

    Tang, Duihai; Zhang, Wenting; Zhang, Yinling; Qiao, Zhen-An; Liu, Yunling; Huo, Qisheng

    2011-04-01

    We have synthesized a series of catalysts for epoxidation of styrene by immobilizing salicylaldimine transition metal (copper, manganese, and cobalt) complexes on mesoporous silica nanoparticles (MSNs) with diameters of 120-150 nm. The prepared catalysts are characterized by infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP), CHN elemental analysis, nitrogen adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). These catalysts possess excellent catalytic efficiency in epoxidation of styrene when using tert-BuOOH (TBHP) as oxidant. Styrene shows a high conversion (∼99%) as well as epoxide selectivity (∼80%) over Cu-MSN catalysts, and high conversion (∼99%) and moderate epoxide selectivity (∼65%) over Mn-MSN and Co-MSN catalysts. The recycling experiment results indicate that these catalysts maintain catalytic activity even after being used for three cycles. Our results indicate that MSNs can serve as better catalyst supports.

  17. High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics

    Energy Technology Data Exchange (ETDEWEB)

    Sirena, M.; Félix, L. Avilés [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Haberkorn, N. [Consejo Nacional de Investigaciones Científicas y Técnicas, Centro Atómico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)

    2013-07-29

    High transition temperature superconductor (HTc)/SrTiO{sub 3} (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (λ ∼ 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (∼5 × 10{sup −5} defects/μm{sup 2}). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

  18. High Power, Room Temperature Terahertz Emitters Based on Dopant Transitions in 6H-Silicon Carbide

    Institute of Scientific and Technical Information of China (English)

    James Kolodzey; Guang-Chi Xuan; Peng-Cheng Lv; Nathan Sustersic; Xin Ma

    2014-01-01

    Electrically pumped high power terahertz (THz) emitters that operated above room temperature in a pulse mode were fabricated from nitrogen-doped n-type 6H-SiC. The emission spectra had peaks centered on 5 THz and 12 THz (20 meV and 50 meV) that were attributed to radiative transitions of excitons bound to nitrogen donor impurities. Due to the relatively deep binding energies of the nitrogen donors, above 100 meV, and the high thermal conductivity of the SiC substrates, the THz output power and operating temperature were significantly higher than previous dopant based emitters. With peak applied currents of a few amperes, and a top surface area of 1 mm2, the device emitted up to 0.5 mW at liquid nitrogen temperature (77 K), and tens of microwatts up to 333 K. This result is the highest temperature of THz emission reported from impurity-based emitters.

  19. Polarization measurement of dielectronic recombination transitions in highly charged krypton ions

    CERN Document Server

    Shah, Chintan; Bernitt, Sven; Dobrodey, Stepan; Steinbrügge, René; Beilmann, Christian; Amaro, Pedro; Hu, Zhimin; Weber, Sebastian; Fritzsche, Stephan; Surzhykov, Andrey; López-Urrutia, José R Crespo; Tashenov, Stanislav

    2016-01-01

    We report linear polarization measurements of x rays emitted due to dielectronic recombination into highly charged krypton ions. The ions in the He-like through O-like charge states were populated in an electron beam ion trap with the electron beam energy adjusted to recombination resonances in order to produce $K\\alpha$ x rays. The x rays were detected with a newly developed Compton polarimeter using a beryllium scattering target and 12 silicon x-ray detector diodes sampling the azimuthal distribution of the scattered x rays. The extracted degrees of linear polarization of several dielectronic recombination transitions agree with results of relativistic distorted--wave calculations. We also demonstrate a high sensitivity of the polarization to the Breit interaction, which is remarkable for a medium-$Z$ element like krypton. The experimental results can be used for polarization diagnostics of hot astrophysical and laboratory fusion plasmas.

  20. Characterization of the K2-19 Multiple-transiting Planetary System via High-dispersion Spectroscopy, AO Imaging, and Transit Timing Variations

    Science.gov (United States)

    Narita, Norio; Hirano, Teruyuki; Fukui, Akihiko; Hori, Yasunori; Sanchis-Ojeda, Roberto; Winn, Joshua N.; Ryu, Tsuguru; Kusakabe, Nobuhiko; Kudo, Tomoyuki; Onitsuka, Masahiro; Delrez, Laetitia; Gillon, Michael; Jehin, Emmanuel; McCormac, James; Holman, Matthew; Izumiura, Hideyuki; Takeda, Yoichi; Tamura, Motohide; Yanagisawa, Kenshi

    2015-12-01

    K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ∼7 R⊕ (inner planet b) and ∼4 R⊕ (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2 m telescope. We find that the host star is a relatively old (≥8 Gyr) late G-type star (Teff ∼ 5350 K, Ms ∼ 0.9 M⊙, and Rs ∼ 0.9 R⊙). We do not find any contaminating faint objects near the host star that could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2 m telescope, TRAPPISTCAM on the TRAPPIST 0.6 m telescope, and MuSCAT on the OAO 1.88 m telescope. We confirm the presence of transit timing variations (TTVs), as previously reported by Armstrong and coworkers. We model the observed TTVs of the inner planet using the synodic chopping formulae given by Deck & Agol. We find two statistically indistinguishable solutions for which the period ratios (Pc/Pb) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet Pb ∼ 7.921 days and the mass of the outer planet Mc ∼ 20 M⊕. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet.