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Sample records for level surface concave

  1. Study on design of the regular concave surface profiles

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Regular concave surface profiles are adopted in many friction surfaces. But up to now,this is seldom tutored by the theory of lubrication. To design them, a model of the regular depthoptimization was provided. To determine the other size, two propositions are given. At same time,two main effect factors on lubrication were discussed in detail. A lubrication test for different regu-lar concave surface profiles was performed on a pin and ring tester. On the basis of theory analy-sis and experiment, a principle to design regular concave surface profiles is provided.

  2. Focusing of Intense Laser via Parabolic Plasma Concave Surface

    Science.gov (United States)

    Zhou, Weimin; Gu, Yuqiu; Wu, Fengjuan; Zhang, Zhimeng; Shan, Lianqiang; Cao, Leifeng; Zhang, Baohan

    2015-12-01

    Since laser intensity plays an important role in laser plasma interactions, a method of increasing laser intensity - focusing of an intense laser via a parabolic plasma concave surface - is proposed and investigated by three-dimensional particle-in-cell simulations. The geometric focusing via a parabolic concave surface and the temporal compression of high harmonics increased the peak intensity of the laser pulse by about two orders of magnitude. Compared with the improvement via laser optics approaches, this scheme is much more economic and appropriate for most femtosecond laser facilities. supported by National Natural Science Foundation of China (Nos. 11174259, 11175165), and the Dual Hundred Foundation of China Academy of Engineering Physics

  3. 3D reconstruction of concave surfaces using polarisation imaging

    Science.gov (United States)

    Sohaib, A.; Farooq, A. R.; Ahmed, J.; Smith, L. N.; Smith, M. L.

    2015-06-01

    This paper presents a novel algorithm for improved shape recovery using polarisation-based photometric stereo. The majority of previous research using photometric stereo involves 3D reconstruction using both the diffuse and specular components of light; however, this paper suggests the use of the specular component only as it is the only form of light that comes directly off the surface without subsurface scattering or interreflections. Experiments were carried out on both real and synthetic surfaces. Real images were obtained using a polarisation-based photometric stereo device while synthetic images were generated using PovRay® software. The results clearly demonstrate that the proposed method can extract three-dimensional (3D) surface information effectively even for concave surfaces with complex texture and surface reflectance.

  4. Transversal stability of the bouncing ball on a concave surface

    Science.gov (United States)

    Chastaing, J.-Y.; Pillet, G.; Taberlet, N.; Géminard, J.-C.

    2015-05-01

    A ball bouncing repeatedly on a vertically vibrating surface constitutes the famous "bouncing ball" problem, a nonlinear system used in the 1980s, and still in use nowadays, to illustrate the route to chaos by period doubling. In experiments, in order to avoid the ball escape that would be inevitable with a flat surface, a concave lens is often used to limit the horizontal motion. However, we observe experimentally that the system is not stable. The ball departs from the system axis and exhibits a pendular motion in the permanent regime. We propose theoretical arguments to account for the decrease of the growth rate and of the asymptotic-size of the trajectory when the frequency of the vibration is increased. The instability is very sensitive to the physics of the contacts, which makes it a potentially interesting way to study the collisions rules, or to test the laws used in numerical studies of granular matter.

  5. Tunable far-field acoustic imaging by two-dimensional sonic crystal with concave incident surface

    Science.gov (United States)

    Shen, Feng-Fu; Lu, Dan-Feng; Zhu, Hong-Wei; Ji, Chang-Ying; Shi, Qing-Fan

    2017-01-01

    An additional concave incident surface comprised of two-dimensional (2D) sonic crystals (SCs) is employed to tune the acoustic image in the far-field region. The tunability is realized through changing the curvature of the concave surface. To explain the tuning mechanism, a simple ray-trace analysis is demonstrated based on the wave-beam negative refractive law. Then, a numerical confirmation is carried out. Results show that both the position and the intensity of the image can be tuned by the introduced concave surface.

  6. Eye movement patterns during the recognition of three-dimensional objects: preferential fixation of concave surface curvature minima.

    Science.gov (United States)

    Leek, E Charles; Cristino, Filipe; Conlan, Lina I; Patterson, Candy; Rodriguez, Elly; Johnston, Stephen J

    2012-01-11

    This study used eye movement patterns to examine how high-level shape information is used during 3D object recognition. Eye movements were recorded while observers either actively memorized or passively viewed sets of novel objects, and then during a subsequent recognition memory task. Fixation data were contrasted against different algorithmically generated models of shape analysis based on: (1) regions of internal concave or (2) convex surface curvature discontinuity or (3) external bounding contour. The results showed a preference for fixation at regions of internal local features during both active memorization and passive viewing but also for regions of concave surface curvature during the recognition task. These findings provide new evidence supporting the special functional status of local concave discontinuities in recognition and show how studies of eye movement patterns can elucidate shape information processing in human vision.

  7. A concave photonic crystal waveguide with a corrugated surface for high-quality focusing

    Institute of Scientific and Technical Information of China (English)

    Hong Wu; Liyong Jiang; Haipeng Li; Wei Jia; Gaige Zheng; Haixia Qiang; Xiangyin Li

    2011-01-01

    @@ A concave two-dimensional (2D) photonic crystal waveguide (PCW) with corrugated surface is theoretically used as a focusing structure. To design this structure, a genetic algorithm is combined with the finite-difference time-domain method. For PCWs with different degrees of concaveness, the power reaches about 80% at different focusing points when the morphology of the concave surface is optimized. More importantly, the focusing location is easily controlled by changing the location of the detector placed in the output field.%A concave two-dimensional (2D) photonic crystal waveguide (PCW) with corrugated surface is theoretically used as a focusing structure. To design this structure, a genetic algorithm is combined with the finite-difference time-domain method. For PCWs with different degrees of concaveness, the power reaches about 80% at different focusing points when the morphology of the concave surface is optimized. More importantly, the focusing location is easily controlled by changing the location of the detector placed in the output field.

  8. Indirect methods to measure wetting and contact angles on spherical convex and concave surfaces.

    Science.gov (United States)

    Extrand, C W; Moon, Sung In

    2012-05-22

    In this work, a method was developed for indirectly estimating contact angles of sessile liquid drops on convex and concave surfaces. Assuming that drops were sufficiently small that no gravitational distortion occurred, equations were derived to compute intrinsic contact angles from the radius of curvature of the solid surface, the volume of the liquid drop, and its contact diameter. These expressions were tested against experimental data for various liquids on polytetrafluoroethylene (PTFE) and polycarbonate (PC) in the form of flat surfaces, spheres, and concave cavities. Intrinsic contact angles estimated indirectly using dimensions and volumes generally agreed with the values measured directly from flat surfaces using the traditional tangent method.

  9. Influence of patterned concave depth and surface curvature on anodization of titania nanotubes and alumina nanopores.

    Science.gov (United States)

    Chen, Bo; Lu, Kathy

    2011-10-04

    Vertically aligned TiO(2) nanotube and Al(2)O(3) nanopore arrays have been obtained by pattern guided anodization with uniform concave depths. There are some studies about the effect of surface curvature on the growth of Al(2)O(3) nanopores. However, the surface curvature influence on the development of TiO(2) nanotubes is seldom studied. Moreover, there is no research about the effect of heterogeneous concave depths of the guiding patterns on the anodized TiO(2) nanotube and Al(2)O(3) nanopore characteristics, such as diameter, growth direction, and termination/bifurcation. In this study, focused ion beam lithography is used to create concave patterns with heterogeneous depths on flat surfaces and with uniform depths on curved surfaces. For the former, bending and bifurcation of nanotubes/nanopores are observed after the anodization. For the latter, bifurcation of a large tube into two smaller tubes occurs on concave surfaces, while termination of existing tubes occurs on convex surfaces. The growth direction of all TiO(2) nanotubes is perpendicular to the local surface and thus is different on different facets of the same Ti foil. At the edge of the Ti foil where two facets meet, the nanotube growth direction is bent, resulting in a large stress release that causes the formation of cracks. © 2011 American Chemical Society

  10. Reproducible and recyclable SERS substrates: Flower-like Ag structures with concave surfaces formed by electrodeposition

    Science.gov (United States)

    Bian, Juncao; Shu, Shiwei; Li, Jianfu; Huang, Chao; Li, Yang Yang; Zhang, Rui-Qin

    2015-04-01

    Direct synthesis of three-dimensional Ag structures on solid substrates for the purposes of producing reproducible and recyclable surface-enhanced Raman scattering (SERS) applications remains challenging. In this work, flower-like Ag structures with concave surfaces (FACS) were successfully electrodeposited onto ITO glass using the double-potentiostatic method. The FACS, with an enhancement factor of the order of 108, exhibited a SERS signal intensity 3.3 times stronger than that measured from Ag nanostructures without concave surfaces. A cleaning procedure involving lengthy immersion of the sample in ethanol and KNO3 was proposed to recycle the substrate and confirmed by using rhodamine 6G, adenine, and 4-aminothiophenol as target molecules. The findings can help to advance the practical applications of Ag nanostructure-based SERS substrates.

  11. The contact angle for a droplet on homogeneous and spherical concave surfaces

    Science.gov (United States)

    Hu, Ai-Jun; Lv, Bao-Zhan; Wang, Xiao-Song; Zhou, Long

    2016-03-01

    Wetting of droplets on homogeneous and spherical concave rough surfaces is investigated based on thermodynamics. In this study, neglecting the droplet gravity and the thickness of the precursor film of the liquid-vapor interface, the three-phase system is divided into six parts using Gibbs concept of dividing surface. The system Helmholtz free energy is established based on thermodynamics. Supposing the temperature and chemical potential to be constant, a new generalized Young’s equation of the equilibrium contact angle for a spherical droplet on a spherical concave rough surfaces is obtained including the line tension effects. Under certain conditions, this generalized Young’s equation is the same as the Rusanov’s equation.

  12. Surface tension-induced high aspect-ratio PDMS micropillars with concave and convex lens tips

    KAUST Repository

    Li, Huawei

    2013-04-01

    This paper reports a novel method for the fabrication of 3-dimensional (3D) Polydimethylsiloxane (PDMS) micropillars with concave and convex lens tips in a one-step molding process, using a CO2 laser-machined Poly(methyl methacrylate) (PMMA) mold with through holes. The PDMS micropillars are 4 mm high and have an aspect ratio of 251. The micropillars are formed by capillary force drawing up PDMS into the through hole mold. The concave and convex lens tips of the PDMS cylindrical micropillars are induced by surface tension and are controllable by changing the surface wetting properties of the through holes in the PMMA mold. This technique eliminates the requirements of expensive and complicated facilities to prepare a 3D mold, and it provides a simple and rapid method to fabricate 3D PDMS micropillars with controllable dimensions and tip shapes. © 2013 IEEE.

  13. Experimental study of curvature effects on jet impingement heat transfer on concave surfaces

    Directory of Open Access Journals (Sweden)

    Ying Zhou

    2017-04-01

    Full Text Available Experimental study of the local and average heat transfer characteristics of a single round jet impinging on the concave surfaces was conducted in this work to gain in-depth knowledge of the curvature effects. The experiments were conducted by employing a piccolo tube with one single jet hole over a wide range of parameters: jet Reynolds number from 27000 to 130000, relative nozzle to surface distance from 3.3 to 30, and relative surface curvature from 0.005 to 0.030. Experimental results indicate that the surface curvature has opposite effects on heat transfer characteristics. On one hand, an increase of relative nozzle to surface distance (increasing jet diameter in fact enhances the average heat transfer around the surface for the same curved surface. On the other hand, the average Nusselt number decreases as relative nozzle to surface distance increases for a fixed jet diameter. Finally, experimental data-based correlations of the average Nusselt number over the curved surface were obtained with consideration of surface curvature effect. This work contributes to a better understanding of the curvature effects on heat transfer of a round jet impingement on concave surfaces, which is of high importance to the design of the aircraft anti-icing system.

  14. Computational flow and heat transfer of a row of circular jets impinging on a concave surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, B.V.N.R.; Prasad, B.V.S.S.S. [Indian Institute of Technology Madras, Thermal Turbomachines Lab, Chennai (India)

    2008-04-15

    A computational investigation is carried out to study the flow and heat transfer from a row of circular jets impinging on a concave surface. The computational domain simulates the impingement cooling zone of a gas turbine nozzle guide vane. The parameters, which are varied in the study include jet Reynolds number (Re{sub d} = 5000-67800), inter-jet distance to jet diameter ratio (c/d = 3.33 and 4.67) and target plate distance to jet diameter ratio (H/d = 1, 3 and 4). The flow field, predicted with K-{omega} turbulence model and using Fluent 6.2.16, is characterized with the presence of a pair of counter rotating vortices, an upwash fountain flow and entrainment. The local pressure coefficient and Nusselt number variations along the concave plate are presented and these values are found to under predict the available experimental data by about 12%. (orig.)

  15. Effect of Concave Sound Reflecting Surfaces on Speech Intelligibility and Articulation Index.

    Science.gov (United States)

    Khaiyat, Sami Abdulrahman

    Three different methods are used to assess speech intelligibility in spaces with and without concave sound reflecting surfaces: calculated articulation index (AI), measured rapid speech transmission index (RASTI), and modified rhyme tests (MRT) with occupants. Factors such as the room size, size of curvature, the speaker's position, and the background noise level are considered in the two on -site testing methods. The MRT results show unexpectedly significant deviation from results obtained through the other methods such that they are de-emphasized in all discussions. Results from rooms without curvatures show no significant differences between the AI and RASTI values; whereas, these differences are significant when rooms with curvatures are considered. A modification factor to be subtracted from calculated AI values to account for erosional effects of the curved surfaces is developed according to further analysis of the differences between the AI and RASTI values. The magnitude of the modification factors depends on all the above factors as well as the location of the listeners within the room. There are no clear indications of any dead spots, however, the sound foci from both the 2ft. and 8ft. curvatures have caused certain group locations to have smaller modification factors than that of all other locations. The magnitude of the developed modification factors ranges between 0.01, for the 16ft. curvature in the small rooms, to 0.17, for the 8ft. curvature in the large room with NC-45 and the speaker's position is on the center. This range is of almost the same magnitude as that of the erosional corrections to calculated AI due to elevated reverberation time. This range is also of almost same magnitude as that of improvement in calculated AI due to presence of visual cues.

  16. Tuning negative refractive collimation beam by square lattice sonic crystal with concave incident surface

    Directory of Open Access Journals (Sweden)

    F. Shen

    2016-02-01

    Full Text Available Negative refractive collimation beam at the low frequency region is achieved in a square lattice sonic crystal with the small magnitude of effective refractive index. A simple tuning approach for such acoustic beam is also proposed by attaching an additional concave surface of incidence to the crystal slab. This can increase the propagation distance of collimation beam, enhance or suppress the beam intensity. The proposed approach is rather general and applicable to other acoustic materials as long as their effective index can be retrieved. Moreover, the results can be applied to wavefront manipulation and transmission enhancement.

  17. Surface Micromachined Adjustable Micro-Concave Mirror for Bio-Detection Applications

    Institute of Scientific and Technical Information of China (English)

    KUO Ju-Nan; CHEN Wei-Lun; JYWE Wen-Yuh

    2009-01-01

    We present a bio-detection system integrated with an adjustable micro-concave mirror.The bio-detection system consists of an adjustable micro-concave mirror,micro flow cytometer chip and optical detection module.The adjustable micro-concave mirror can be fabricated with ease using commercially available MEMS foundry services (such as multiuser MEMS processes,MUMPs) and its curvature can be controlled utilizing thermal or electrical effects.Experimental results show that focal lengths of the micro-concave mirror ranging from 313.5 to 2275.0 μm are achieved.The adjustable micro-concave mirror can be used to increase the efficiency of optical detection and provide a high signal-to-noise ratio.The developed micro-concave mirror is integrated with a micro flow cytometer for cell counting applications.Successful counting of fluorescent-labeled beads is demonstrated using the developed method.

  18. Numerical modeling of a turbulent semi-confined slot jet impinging on a concave surface

    Directory of Open Access Journals (Sweden)

    Ahmadi Hadi

    2015-01-01

    Full Text Available This article presents results from a numerical study of a turbulent slot jet impinging on a concave surface. Five different low Reynolds number k-ε models were evaluated to predict the heat transfer under a two dimensional steady turbulent jet. The effects of flow and geometrical parameters (e.g. jet Reynolds number and jet-to-target separation distance have been investigated. The Yap correction is applied for reducing the over-prediction of Nusselt number in the near wall region. It is shown that among the models tested in this study, the LS-Yap model is capable of predicting local Nusselt number in good agreement with the experimental data in both stagnation and wall jet region. Moreover, after implementation of Yap correction, no significant effect of the nozzle-to-surface distance, h/B, on the predicted stagnation Nusselt number has been found. Finally it is demonstrated that the higher values of turbulent Prandtl number reduces the heat diffusion along the wall and consequently the predicted local Nusselt number is reduced especially in the wall jet region.

  19. An orthogonal coordinate grid following the three-dimensional viscous flow over a concave surface

    Science.gov (United States)

    Dagenhart, J. R; Saric, W. S.

    1983-01-01

    Swept wings designed for laminar flow control exhibit both centrifugal and crossflow instabilities which produce streamwise vortices that can lead to early transition from laminar to turbulent flow in the presence of Tollmien-Schlichting waves. This paper outlines an iterative algorithm for generation of an orthogonal, curvilinear, coordinate grid following the streamlines of the three-dimensional viscous flow over a swept, concave surface. The governing equations for the metric tensor are derived from the Riemann-Christoffel tensor for an Euclidian geometry. Unit vectors along streamline, normal and binormal directions are determined. The governing equations are not solved directly, but are employed only as compatibility equations. The scale factor for the streamline coordinate is obtained by an iterative integration scheme on a 200 x 100 x 5 grid, while the other two scale factors are determined from definitions. Sample results are obtained which indicate that the compatibility equation error decreases linearly with grid step size. Grids smaller than 200 x 100 x 5 are found to be inadequate to resolve the grid curvature.

  20. Development of twin-illumination and subtraction technique for detection of concave and convex defects on steel surfaces

    Science.gov (United States)

    Ono, Hiroaki; Ogawa, Akihiro; Yamasaki, Takahiro; Koshihara, Takahiro; Kodama, Toshifumi; Iizuka, Yukinori; Oshige, Takahiko

    2016-09-01

    Optical surface inspection of steel mill products such as pipes, plates and slabs usually has the problem of overdetection, which is caused by signals from harmless parts such as scale and surface texture. The authors propose a new inspection technique based on the experience that most harmful defects on these products have a concave or convex shape, whereas most harmless parts that might be overdetected have flat shapes. The proposed technique is called the `twin-illumination and subtraction technique'. In this technique, firstly, two images of the target area on a steel surface illuminated from the two sides are captured, respectively. A subtraction image is then calculated from these images. Comparing the images illuminated from the different sides, the images from concave or convex defects look different due to their different shadows, while images from harmless flat parts look the same because illumination does not cause any shadow. As a result, two images with the same appearances from a harmless part are canceled by subtraction, and two images with different appearances from a concave or convex defect remain even after subtraction. Finally, it is possible to detect only concave or convex defects without overdetecting flat patterns. In this manuscript, first, we explain the proposed technique and confirmation experiments in the laboratory. We also explain a new optical inspection system based on the concept described above and its application to moving hot pipes in a steel manufacturing plant to prove the effectiveness of the technique. We concluded that the inspection system has sufficient performance for use as a practical system.

  1. Restricted mobility of side chains on concave surfaces of solenoid proteins may impart heightened potential for intermolecular interactions.

    Science.gov (United States)

    Ramya, L; Gautham, N; Chaloin, Laurent; Kajava, Andrey V

    2015-09-01

    Significant progress has been made in the determination of the protein structures with their number today passing over a hundred thousand structures. The next challenge is the understanding and prediction of protein-protein and protein-ligand interactions. In this work we address this problem by analyzing curved solenoid proteins. Many of these proteins are considered as "hub molecules" for their high potential to interact with many different molecules and to be a scaffold for multisubunit protein machineries. Our analysis of these structures through molecular dynamics simulations reveals that the mobility of the side-chains on the concave surfaces of the solenoids is lower than on the convex ones. This result provides an explanation to the observed preferential binding of the ligands, including small and flexible ligands, to the concave surface of the curved solenoid proteins. The relationship between the landscapes and dynamic properties of the protein surfaces can be further generalized to the other types of protein structures and eventually used in the computer algorithms, allowing prediction of protein-ligand interactions by analysis of protein surfaces.

  2. Refined ray tracing inside single- and double-curvatured concave surfaces

    CERN Document Server

    Choudhury, Balamati

    2016-01-01

    This book describes the ray tracing effects inside different quadric surfaces. Analytical surface modeling is a priori requirement for electromagnetic (EM) analysis over aerospace platforms. Although numerically-specified surfaces and even non-uniform rational basis spline (NURBS) can be used for modeling such surfaces, for most practical EM applications, it is sufficient to model them as quadric surface patches and the hybrids thereof. It is therefore apparent that a vast majority of aerospace bodies can be conveniently modeled as combinations of simpler quadric surfaces, i.e. hybrid of quadric cylinders and quadric surfaces of revolutions. Hence the analysis of geometric ray tracing inside is prerequisite to analyzing the RF build-up. This book, describes the ray tracing effects inside different quadric surfaces such as right circular cylinder, general paraboloid of revolution (GPOR), GPOR frustum of different shaping parameters and the corresponding visualization of the ray-path details. Finally ray tracin...

  3. MOF-templated synthesis of porous Co(3)O(4) concave nanocubes with high specific surface area and their gas sensing properties.

    Science.gov (United States)

    Lü, Yinyun; Zhan, Wenwen; He, Yue; Wang, Yiting; Kong, Xiangjian; Kuang, Qin; Xie, Zhaoxiong; Zheng, Lansun

    2014-03-26

    Porous metal oxides nanomaterials with controlled morphology have received great attention because of their promising applications in catalysis, energy storage and conversion, gas sensing, etc. In this paper, porous Co3O4 concave nanocubes with extremely high specific surface area (120.9 m(2)·g(-1)) were synthesized simply by calcining Co-based metal-organic framework (Co-MOF, ZIF-67) templates at the optimized temperature (300 °C), and the formation mechanism of such highly porous structures as well as the influence of the calcination temperature are well explained by taking into account thermal behavior and intrinsic structural features of the Co-MOF precursors. The gas-sensing properties of the as-synthesized porous Co3O4 concave nanocubes were systematically tested towards volatile organic compounds including ethanol, acetone, toluene, and benzene. Experimental results reveal that the porous Co3O4 concave nanocubes present the highest sensitivity to ethanol with fast response/recovery time (< 10 s) and a low detection limit (at least 10 ppm). Such outstanding gas sensing performance of the porous Co3O4 concave nanocubes benefits from their high porosity, large specific surface area, and remarkable capabilities of surface-adsorbed oxygen.

  4. Reproducible Construction of Surface Tension-Mediated Honeycomb Concave Microwell Arrays for Engineering of 3D Microtissues with Minimal Cell Loss.

    Science.gov (United States)

    Lee, GeonHui; Lee, JaeSeo; Oh, HyunJik; Lee, SangHoon

    2016-01-01

    The creation of engineered 3D microtissues has attracted prodigious interest because of the fact that this microtissue structure is able to mimic in vivo environments. Such microtissues can be applied extensively in the fields of regenerative medicine and tissue engineering, as well as in drug and toxicity screening. Here, we develop a novel method of fabricating a large number of dense honeycomb concave microwells via surface tension-mediated self-construction. More specifically, in order to control the curvature and shape of the concavity in a precise and reproducible manner, a custom-made jig system was designed and fabricated. By applying a pre-set force using the jig system, the shape of the honeycomb concave well was precisely and uniformly controlled, despite the fact that wells were densely packed. The thin wall between the honeycomb wells enables the minimization of cell loss during the cell-seeding process. To evaluate the performance of the honeycomb microwell array, rat hepatocytes were seeded, and spheroids were successfully formed with uniform shape and size. Liver-specific functions such as albumin secretion and cytochrome P450 were subsequently analyzed. The proposed method of fabricating honeycomb concave wells is cost-effective, simple, and reproducible. The honeycomb well array can produce multiple spheroids with minimal cell loss, and can lead to significant contributions in tissue engineering and organ regeneration.

  5. 2D numerical simulation of impinging jet onto the concave surface by k - w - overline{{v2 }} - f turbulence model

    Science.gov (United States)

    Seifi, Zeinab; Nazari, Mohammad Reza; Khalaji, Erfan

    2016-03-01

    In the present article, the characteristics of turbulent jet impinging onto a concave surface is studied using k - w - overline{{v2 }} - f turbulence model. Dependent parameters such as inlet Reynolds number (2960 heat transfer of stagnation area and wall jet goes up and down through nozzle-plate distance enhancement respectively. Finally, the effects of sinusoidal pulsed inlet profile on heat transfer of unconfined impinging jet indicate direct affiliation of amplitude and neutral impact of frequency on Nusselt number distribution.

  6. Investigation of Micro-wear and Micro-friction Properties for Bionic Non-smooth Concave Components

    Institute of Scientific and Technical Information of China (English)

    Han Zhi-wu; Xu Xiao-xia; Qiu Zhao-mei; Ren Lu-quan

    2005-01-01

    Five kinds of 45# steel samples with concave features on the surface were manufactured using Laser Texturing Technology (LTT). Optimum design theory was used to design the experiment, and a two-level orthogonal table -L16 (215) design was adopted . Micro-wear and micro-friction experienced by samples with concave surface features and samples with smooth surfaces were compared experimentally. The wear resistance of samples with concave surface features was increased most,and different surface morphologies had different effects on friction and wear properties.

  7. Configuration design and accuracy analysis of a novel magneto rheological finishing machine tool for concave surfaces with small radius of curvature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Henan; Chen, Mingjun [Harbin Institute of Technology, Harbin (China); Yu, Bo; Zhen, Fang [China Electronics Technology Group Corporation No.26 Research Institute, Chongqing (China)

    2016-07-15

    Magnetorheological finishing (MRF) is a computer-controlled deterministic polishing technique that is widely used in the production of high-quality optics. In order to overcome the defects of existing MRF processes that are unable to achieve concave surfaces with small radius of curvature, a configuration method of a novel structured MRF machine tool using small ball-end permanent-magnet polishing head is proposed in this paper. The preliminary design focuses on the structural configuration of the machine, which includes the machine body, motion units and accessory equipment, and so on. Structural deformation and fabrication accuracy of the machine are analyzed theoretically, in which the reasonable structure sizes, manufacturing errors and assembly errors of main structural components are given for configuration optimization. Based on the theoretical analysis, a four-axes linkage MRF machine tool is developed. Preliminary experiments of spot polishing are carried out and the results indicate that the proposed MRF process can achieve stable polishing area which meets requirement of deterministic polishing. A typical small-bore complex component is polished on the developed device and fine surface quality is obtained with sphericity of the finished spherical surfaces 1.3 μm and surface roughness Ra less than 0.018 μm.

  8. Concave Pit-Containing Scaffold Surfaces Improve Stem Cell-Derived Osteoblast Performance and Lead to Significant Bone Tissue Formation

    Science.gov (United States)

    Cusella-De Angelis, Maria Gabriella; Laino, Gregorio; Piattelli, Adriano; Pacifici, Maurizio; De Rosa, Alfredo; Papaccio, Gianpaolo

    2007-01-01

    Background Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear. Methodology and Findings In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA) scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone) to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i) large microcavities of 80–120 µm in diameter and 40–100 µm in depth, which we termed primary; and (ii) smaller microcavities of 10–20 µm in diameter and 3–10 µm in depth located within the primary cavities, which we termed secondary. We asked whether a microcavity-rich scaffold had distinct bone-forming capabilities compared to a smooth one. To do so, mesenchymal stem cells derived from human dental pulp were seeded onto the two types of scaffold and monitored over time for cytoarchitectural characteristics, differentiation status and production of important factors, including bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF). We found that the microcavity-rich scaffold enhanced cell adhesion: the cells created intimate contact with secondary microcavities and were polarized. These cytological responses were not seen with the smooth-surface scaffold. Moreover, cells on the microcavity-rich scaffold released larger amounts of BMP-2 and VEGF into the culture medium and expressed higher alkaline phosphatase activity. When this type of scaffold was transplanted into rats, superior bone formation was elicited compared to cells seeded on the smooth scaffold. Conclusion In conclusion, surface microcavities appear to support a more vigorous osteogenic response of stem cells and should be used in the design of therapeutic substrates to improve bone repair and

  9. Cuspidal caustic and focusing of acoustical waves generated by a parametric array onto a concave reflecting surface

    Science.gov (United States)

    Castagnède, Bernard; Sahraoui, Sohbi; Tournat, Vincent; Tahani, Najat

    2009-09-01

    The present Note is devoted to the study of the so-called cuspidal caustic at the surface of a hemi-cylindrical reflector illuminated with plane waves. In order to generate low frequency (e.g. in the range of 4 kHz) acoustical plane waves, a commercially available parametric array has been used. It produces powerful ultrasonic carrier waves at 40 kHz which can be electronically modulated between 200 Hz and 10 kHz. Further self-demodulation process during propagation in air generates an ultra-directive acoustical field (i.e. quasi-planar wavefronts) enabling to accurately study the focusing process occurring along the cuspidal caustic. The focusing coefficient can be computed locally by using two numerical tools, on one hand by computing the density of tangent rays to the caustic, and on the other hand by using some numerical results provided by a ray tracing algorithm. Some preliminary experimental data are then provided in order to validate the numerical predictions (spatial position of the caustic and focusing coefficient). To cite this article: B. Castagnède et al., C. R. Mecanique 337 (2009).

  10. Optimal convex shapes for concave functionals

    CERN Document Server

    Bucur, Dorin; Lamboley, Jimmy

    2011-01-01

    Motivated by a long-standing conjecture of Polya and Szeg\\"o about the Newtonian capacity of convex bodies, we discuss the role of concavity inequalities in shape optimization, and we provide several counterexamples to the Blaschke-concavity of variational functionals, including capacity. We then introduce a new algebraic structure on convex bodies, which allows to obtain global concavity and indecomposability results, and we discuss their application to isoperimetriclike inequalities. As a byproduct of this approach we also obtain a quantitative version of the Kneser-S\\"uss inequality. Finally, for a large class of functionals involving Dirichlet energies and the surface measure, we perform a local analysis of strictly convex portions of the boundary via second order shape derivatives. This allows in particular to exclude the presence of smooth regions with positive Gauss curvature in an optimal shape for Polya-Szeg\\"o problem.

  11. Fast approximate convex decomposition using relative concavity

    KAUST Repository

    Ghosh, Mukulika

    2013-02-01

    Approximate convex decomposition (ACD) is a technique that partitions an input object into approximately convex components. Decomposition into approximately convex pieces is both more efficient to compute than exact convex decomposition and can also generate a more manageable number of components. It can be used as a basis of divide-and-conquer algorithms for applications such as collision detection, skeleton extraction and mesh generation. In this paper, we propose a new method called Fast Approximate Convex Decomposition (FACD) that improves the quality of the decomposition and reduces the cost of computing it for both 2D and 3D models. In particular, we propose a new strategy for evaluating potential cuts that aims to reduce the relative concavity, rather than absolute concavity. As shown in our results, this leads to more natural and smaller decompositions that include components for small but important features such as toes or fingers while not decomposing larger components, such as the torso, that may have concavities due to surface texture. Second, instead of decomposing a component into two pieces at each step, as in the original ACD, we propose a new strategy that uses a dynamic programming approach to select a set of n c non-crossing (independent) cuts that can be simultaneously applied to decompose the component into n c+1 components. This reduces the depth of recursion and, together with a more efficient method for computing the concavity measure, leads to significant gains in efficiency. We provide comparative results for 2D and 3D models illustrating the improvements obtained by FACD over ACD and we compare with the segmentation methods in the Princeton Shape Benchmark by Chen et al. (2009) [31]. © 2012 Elsevier Ltd. All rights reserved.

  12. Bi-log-concave Distribution Functions

    DEFF Research Database (Denmark)

    Dümbgen, Lutz; Kolesnyk, Petro; Wilke, Ralf

    2017-01-01

    Nonparametric statistics for distribution functions F or densities f=F′ under qualitative shape constraints constitutes an interesting alternative to classical parametric or entirely nonparametric approaches. We contribute to this area by considering a new shape constraint: F is said to be bi......-log-concave, if both logF and log(1−F) are concave. Many commonly considered distributions are compatible with this constraint. For instance, any c.d.f. F with log-concave density f=F′ is bi-log-concave. But in contrast to log-concavity of f, bi-log-concavity of F allows for multimodal densities. We provide various...

  13. Convex and Radially Concave Contoured Distributions

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Richter

    2015-01-01

    Full Text Available Integral representations of the locally defined star-generalized surface content measures on star spheres are derived for boundary spheres of balls being convex or radially concave with respect to a fan in Rn. As a result, the general geometric measure representation of star-shaped probability distributions and the general stochastic representation of the corresponding random vectors allow additional specific interpretations in the two mentioned cases. Applications to estimating and testing hypotheses on scaling parameters are presented, and two-dimensional sample clouds are simulated.

  14. Flow behind concave shock waves

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Curved shock theory is introduced and applied to calculate the flow behind concave shock waves. For sonic conditions, three characterizing types of flow are identified, based on the orientation of the sonic line, and it is shown that, depending on the ratio of shock curvatures, a continuously curving shock can exist with Type III flow, where the sonic line intercepts the reflected characteristics from the shock, thus preventing the formation of a reflected shock. The necessary shock curvature ratio for a Type III sonic point does not exist for a hyperbolic shock so that it will revert to Mach reflection for all Mach numbers. A demonstration is provided, by CFD calculations, at Mach 1.2 and 3.

  15. Flow behind concave shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is introduced and applied to calculate the flow behind concave shock waves. For sonic conditions, three characterizing types of flow are identified, based on the orientation of the sonic line, and it is shown that, depending on the ratio of shock curvatures, a continuously curving shock can exist with Type III flow, where the sonic line intercepts the reflected characteristics from the shock, thus preventing the formation of a reflected shock. The necessary shock curvature ratio for a Type III sonic point does not exist for a hyperbolic shock so that it will revert to Mach reflection for all Mach numbers. A demonstration is provided, by CFD calculations, at Mach 1.2 and 3.

  16. Chernoff's density is log-concave.

    Science.gov (United States)

    Balabdaoui, Fadoua; Wellner, Jon A

    2014-02-01

    We show that the density of Z = argmax{W (t) - t(2)}, sometimes known as Chernoff's density, is log-concave. We conjecture that Chernoff's density is strongly log-concave or "super-Gaussian", and provide evidence in support of the conjecture.

  17. Nonparametric Bayes inference for concave distribution functions

    DEFF Research Database (Denmark)

    Hansen, Martin Bøgsted; Lauritzen, Steffen Lilholt

    2002-01-01

    Bayesian inference for concave distribution functions is investigated. This is made by transforming a mixture of Dirichlet processes on the space of distribution functions to the space of concave distribution functions. We give a method for sampling from the posterior distribution using a Pólya urn...

  18. Concave cell design for FTIR measurements

    Institute of Scientific and Technical Information of China (English)

    Xiang Qin Lin; Zhi Xiang Zhang; Wan Qun Hu

    2011-01-01

    Wedged and V-shaped cells have advantages on depressing strong absorption bands and keeping the photo windows wide open without absorption block. Alternatively, this work presents a concave cell design, which is constructed by a plano-convex CaF2 lens in combination with a flat plate. Mathematical equations have been provided for data treatment with Matlab programs. The result indicates that the concave cell has advantages similar to the V-shaped cell. Reflection-absorption measurements of ethanol have been conducted on the cell in mid-IR region for demonstration. The spectrum obtained from the concave cell can easily be interpreted to regenerate its normal spectrum, which is fitting well with the spectrum taken in a conventional thin-layer cell. The concave cell is easier to construct and more convenient to operate, willing to have popular usages.

  19. The Iterative Method of Generalized -Concave Operators

    Directory of Open Access Journals (Sweden)

    Zhou Yanqiu

    2011-01-01

    Full Text Available We define the concept of the generalized -concave operators, which generalize the definition of the -concave operators. By using the iterative method and the partial ordering method, we prove the existence and uniqueness of fixed points of this class of the operators. As an example of the application of our results, we show the existence and uniqueness of solutions to a class of the Hammerstein integral equations.

  20. Resource Allocation Problems with Concave Reward Functions

    NARCIS (Netherlands)

    Grundel, S.; Borm, P.E.M.; Hamers, H.J.M.

    2013-01-01

    Abstract: In a resource allocation problem there is a common-pool resource, which has to be divided among agents. Each agent is characterized by a claim on this pool and an individual concave reward function on assigned resources. An assignment of resources is optimal if the total joint reward is ma

  1. MISR Level 2 Surface parameters V002

    Data.gov (United States)

    National Aeronautics and Space Administration — This Level 2 Land Surface product contains information on land directional reflectance properties,albedos(spectral & PAR integrated),FPAR,asssociated radiation...

  2. Optimal Portfolio Selection Under Concave Price Impact

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jin, E-mail: jinma@usc.edu [University of Southern California, Department of Mathematics (United States); Song Qingshuo, E-mail: songe.qingshuo@cityu.edu.hk [City University of Hong Kong, Department of Mathematics (Hong Kong); Xu Jing, E-mail: xujing8023@yahoo.com.cn [Chongqing University, School of Economics and Business Administration (China); Zhang Jianfeng, E-mail: jianfenz@usc.edu [University of Southern California, Department of Mathematics (United States)

    2013-06-15

    In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a 'piecewise constant' form, reflecting a more practical perspective.

  3. Optimal Portfolio Selection under Concave Price Impact

    CERN Document Server

    Ma, Jin; Xu, Jing; Zhang, Jianfeng

    2012-01-01

    In this paper we study an optimal portfolio selection problem under instantaneous price compact. Based some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either the liquidity cost or transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a "piecewise constant" form, reflecting a more practical perspective.

  4. Local matching indicators for concave transport costs

    CERN Document Server

    Delon, Julie; Sobolevskii, A

    2009-01-01

    In this note, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of $N$ demands and $N$ supplies in $\\mathbf{R}$ in the case where the cost function is concave. The cost of these indicators is small and independent of $N$. Using them recursively according to a particular algorithm allows to find an optimal transport plan in less than $N^2$ evaluations of the cost function.

  5. Mills' ratio: Reciprocal concavity and functional inequalities

    CERN Document Server

    Baricz, Árpád

    2010-01-01

    This note contains suficient conditions for the probability density function of an arbitrary continuous univariate distribution such that the corresponding Mills ratio to be reciprocally convex (concave). To illustrate the applications of the main results, the Mills ratio of some common continuous univariate distributions, like gamma, log-normal and Student's t distributions, are discussed in details. The application to monopoly theory is also summarized.

  6. Microtrap on a concave grating reflector for atom trapping

    Science.gov (United States)

    Zhang, Hui; Li, Tao; Yin, Ya-Ling; Li, Xing-Jia; Xia, Yong; Yin, Jian-Ping

    2016-08-01

    We propose a novel scheme of optical confinement for atoms by using a concave grating reflector. The two-dimension grating structure with a concave surface shape exhibits strong focusing ability under radially polarized illumination. Especially, the light intensity at the focal point is about 100 times higher than that of the incident light. Such a focusing optical field reflected from the curved grating structure can provide a deep potential to trap cold atoms. We discuss the feasibility of the structure serving as an optical dipole trap. Our results are as follows. (i) Van der Waals attraction potential to the surface of the structure has a low effect on trapped atoms. (ii) The maximum trapping potential is ˜ 1.14 mK in the optical trap, which is high enough to trap cold 87Rb atoms from a standard magneto-optical trap with a temperature of 120 μK, and the maximum photon scattering rate is lower than 1/s. (iii) Such a microtrap array can also manipulate and control cold molecules, or microscopic particles. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374100, 91536218, and 11274114) and the Natural Science Foundation of Shanghai Municipality, China (Grant No. 13ZR1412800).

  7. Negative Goos-Hänchen shift on a concave dielectric interface.

    Science.gov (United States)

    Zhou, L-M; Zou, C-L; Han, Z-F; Guo, G-C; Sun, F-W

    2011-03-01

    We study the Goos-Hänchen shift (GHS) on a curved surface through numerical simulation by the boundary element method. A negative GHS is first discovered on a concave dielectric interface below the critical angle, accompanied by a large positive GHS on the convexity. The simulation shows that the GHS on a planar interface is the composition of the GHS from a concave and the corresponding convex interface. This work will enrich the study of the GHS for different curved surfaces, which will have potential applications in micro-optics and near-field optics.

  8. Concave Majorants of Random Walks and Related Poisson Processes

    CERN Document Server

    Abramson, Josh

    2010-01-01

    We offer a unified approach to the theory of concave majorants of random walks by providing a path transformation for a walk of finite length that leaves the law of the walk unchanged whilst providing complete information about the concave majorant. This leads to a description of a walk of random geometric length as a Poisson point process of excursions away from its concave majorant, which is then used to find a complete description of the concave majorant for a walk of infinite length. In the case where subsets of increments may have the same arithmetic mean, we investigate three nested compositions that naturally arise from our construction of the concave majorant.

  9. The concave river long profile: a morphodynamic steady state?

    Science.gov (United States)

    Blom, A.

    2011-12-01

    By definition, a morphodynamic steady state is governed by a spatially constant sediment transport rate. As the sediment transport rate is a function of shear stress associated with skin friction, the morphodynamic steady state has been considered to be governed by a spatially constant bed slope. For this reason, the typical concave river long profile has been considered to be a quasi-steady state. The river's steady state has been considered to be one with a spatially constant bed slope, with tributaries inducing a stepwise decrease in bed slope in streamwise direction. Yet, for the sediment transport rate to be spatially constant, it rather is the product of water surface slope and water depth associated with skin friction that needs to be constant. This implies that physical mechanisms that induce streamwise variation in the sediment transport rate can be compensated by a streamwise variation in bed slope so as to guarantee a spatially constant sediment transport rate. Following the river course, such physical mechanisms can be bedrock exposure, partial transport, and a spatially lagging bedform growth. At locations where tributaries increase the water discharge, the above mechanisms cause the river bed profile to be upward concave over a significant reach. At bifucations or at locations where river widening prevails, the river bed profile is upward convex.

  10. Irradiation of target volumes with concave outlines

    Energy Technology Data Exchange (ETDEWEB)

    De Neve, W.; Fortan, L.; Derycke, S.; Van Duyse, B.; DE Wagter, C. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

    1995-12-01

    A heuristic planning procedure allowing to obtain a 3-dimensional conformal dose distribution for target volumes with concavities has been investigated. The procedure divides the planning problem into a number of sub-problems each solvable by known methods. By patching together the solutions to the sub-problems, a solution with a predictable dosimetric outcome can be obtained. The procedure can be applied to most 3-dimensional systems. The procedure is described and its applications to the irradiation of neoplasms are discussed. (A.S.).

  11. Nanoscale aluminum concaves for light-trapping in organic thin-films

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    2016-01-01

    Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation...... technique. Local ablation spots, corresponding to field enhancement on the ridge edges of the aluminum concave nanostructures, are observed in surface-covering polymer films, and confirmed with FDTD studies. The field enhancement leads to improved light absorption in the applied polymer layers, which may...

  12. An acoustical analysis of a room with a concave dome ceiling element

    Science.gov (United States)

    Utami, Sentagi S.

    2004-05-01

    Concave surfaces are often considered detrimental in room acoustics, especially because of the impact they have on the distribution of sound energy. This paper explores certain acoustical characteristics and anomalies found in spaces below concave dome ceiling elements. The architectural design of the Darusshollah mosque in East Java, Indonesia is used as a case study with specific spatial and functional concerns. Investigations of the mosque have been conducted through both a 1:12 scale model and a computer model that utilizes ray tracing and image source methods. Analysis techniques are discussed. Results are presented and compared to provide useful insights into the acoustics of such distinctive environments.

  13. Laser detection of ultrasonic waves with concave portions of the wave fronts.

    Science.gov (United States)

    Korkh, Yulia; Perov, Dmitry; Rinkevich, Anatoly

    2012-10-01

    Special features of ultrasonic pulse wave field detection with concave regions of the wave fronts are investigated with the use of ultrasonic laser interferometry technique. Experimental proofs of the wave front with concave regions are obtained and it is found that the nonmonotonic wave front profiles are well described by the fourth-order even polynomial. The model proposed is applied to the investigation of the spatiotemporal structure of elastic wave fields on solid surfaces. The results obtained can be used for estimating the local wave front curvature.

  14. Nanoscale aluminum concaves for light-trapping in organic thin-films

    Science.gov (United States)

    Goszczak, Arkadiusz Jarosław; Adam, Jost; Cielecki, Paweł Piotr; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten

    2016-07-01

    Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation technique. Local ablation spots, corresponding to field enhancement on the ridge edges of the aluminum concave nanostructures, are observed in surface-covering polymer films, and confirmed with FDTD studies. The field enhancement leads to improved light absorption in the applied polymer layers, which may be used as an efficient method for enhancing the power conversion efficiency of organic solar cells.

  15. A study of the depth and size of concave cube Au nanoparticles as highly sensitive SERS probes

    Science.gov (United States)

    Romo-Herrera, J. M.; González, A. L.; Guerrini, L.; Castiello, F. R.; Alonso-Nuñez, G.; Contreras, O. E.; Alvarez-Puebla, R. A.

    2016-03-01

    High and uniform near fields are localized at the eight similar sharp corners of cubic gold nanoparticles. Moreover, by introducing concavity in the particle lateral planes, such field intensities can be further increased and tuned in the near infrared region without altering the overall size of the nanoparticles. Herein, we perform a thorough investigation of the morphological, crystallographic and plasmonic properties of concave gold nanocubes (GNCs) in the sub-70 nm size range, for their potential application as highly efficient SERS substrates in size-limiting cases. Theoretical calculations indicate that the highest increment of the near-field is located at the eight sharp tips and, interestingly, a medium near-field increment is also activated over the volume next to the concave surface. Remarkably, the plasmonic response of the concave cubic morphology showed great sensitivity to the concavity degree. Experimental SERS analysis nicely matches the outcome of the theoretical model, confirming that medium-sized concave GNCs (35 nm side length) possess the highest SERS activity upon excitation with a 633 nm laser, whereas larger 61 nm side concave GNCs dominate the optical response at 785 nm. Due to their size-intensity trade off, we envision that such small concave gold nanocubes can provide a highly active and efficient SERS platform for size-limiting applications, especially when near infrared excitations are required.High and uniform near fields are localized at the eight similar sharp corners of cubic gold nanoparticles. Moreover, by introducing concavity in the particle lateral planes, such field intensities can be further increased and tuned in the near infrared region without altering the overall size of the nanoparticles. Herein, we perform a thorough investigation of the morphological, crystallographic and plasmonic properties of concave gold nanocubes (GNCs) in the sub-70 nm size range, for their potential application as highly efficient SERS

  16. An experimental investigation of the supersonic turbulent boundary layer subjected to concave curvature

    Science.gov (United States)

    Wang, Qian-cheng; Wang, Zhen-guo; Zhao, Yu-xin

    2016-09-01

    By employing particle image velocimetry, the response of a Mach 2.95 turbulent boundary layer to the concave curvature is experimentally investigated. The radius of the concave wall is 350 mm, and the turning angle is 20∘. Logarithmic law is well preserved in the profile of streamwise velocity at all streamwise positions despite the impact of curvature. The varying trend of principal strain rate is found to be different at different heights within the boundary layer, which cannot be explained by the suggestion given by former researchers. Based on the three-layer model proposed in this paper, distribution of the principal strain rate is carefully analyzed. The streamwise increase of wall friction is suggested to be brought by the increase of velocity gradient in the thin subsonic layer. Increases of the static temperature and the related sound speed are responsible for that. Larger correlated turbulent motions could be introduced by the concave curvature. The probability density histograms of streamwise velocity reveal that the large scale hairpin packets are statistically well organized. The concave curvature is found to have the potential of reinforcing the organization, which explains the increase of turbulent level in the supersonic concave boundary layer.

  17. A Universal Generator for Bivariate Log-Concave Distributions

    OpenAIRE

    Hörmann, Wolfgang

    1995-01-01

    Different universal (also called automatic or black-box) methods have been suggested to sample from univariate log-concave distributions. The description of a universal generator for bivariate distributions has not been published up to now. The new algorithm for bivariate log-concave distributions is based on the method of transformed density rejection. In order to construct a hat function for a rejection algorithm the bivariate density is transformed by the logarithm into a concave function....

  18. MECHANICAL ANALYSIS OF CYLINDERS BEING UPSET BETWEEN SPHERICAL CONCAVE PLATEN AND CONCAVE SUPPORTING PLATE

    Institute of Scientific and Technical Information of China (English)

    LIU Guohui; XIAO Wenhui; NI Liyong; LIU Zhubai

    2008-01-01

    Mechanical analysis of cylinders being upset between spherical concave platen and concave supporting plate is conducted. Rigid-plastic mechanical models for cylinders are presented. When the ratio of height to diameter, is larger than 1, there exists two-dimensional tensile stress in the deformed body, when the ratio is smaller than 1, there exists shear stress in static hydraulic zone. The former breaks through the theory that there is three-dimensional compressive stress irrespective of any ratio of height to diameter. The latter satisfactorily explains the mechanism of layer-like cracks in disk-shaped forgings and the flanges of forged gear axles. The representation of the two models makes the upsetting theory into correct and perfect stage.

  19. Application of concave microwells to pancreatic tumor spheroids enabling anticancer drug evaluation in a clinically relevant drug resistance model.

    Directory of Open Access Journals (Sweden)

    Sang-Eun Yeon

    Full Text Available Intrinsic drug resistance of pancreatic ductal adenocarcinoma (PDAC warrants studies using models that are more clinically relevant for identifying novel resistance mechanisms as well as for drug development. Tumor spheroids (TS mimic in vivo tumor conditions associated with multicellular resistance and represent a promising model for efficient drug screening, however, pancreatic cancer cells often fail to form spheroids using conventional methods such as liquid overlay. This study describes the induction of TS of human pancreatic cancer cells (Panc-1, Aspc-1, Capan-2 in concave polydimethylsiloxane (PDMS microwell plates and evaluation of their usefulness as an anticancer efficacy test model. All three cell lines showed TS formation with varying degree of necrosis inside TS. Among these, Panc-1 spheroid with spherical morphology, a rather rough surface, and unique adhesion structures were successfully produced with no notable necrosis in concave microwell plates. Panc-1 TS contained growth factors or enzymes such as TGF-β1, CTGF, and MT1-MMP, and extracellular matrix proteins such as collagen type I, fibronectin, and laminin. Panc-1 cells grown as TS showed changes in stem cell populations and in expression levels of miRNAs that may play roles in chemoresistance. Visualization of drug penetration and detection of viability indicators, such as Ki-67 and MitoSOX, were optimized for TS for quantitative analysis. Water-soluble tetrazolium (MTS and acid phosphatase (APH assays were also successfully optimized. Overall, we demonstrated that concave PDMS microwell plates are a novel platform for preparation of TS of weakly aggregating cells and that Panc-1 spheroids may represent a novel three-dimensional model for anti-pancreatic cancer drug screening.

  20. Application of concave microwells to pancreatic tumor spheroids enabling anticancer drug evaluation in a clinically relevant drug resistance model.

    Science.gov (United States)

    Yeon, Sang-Eun; No, Da Yoon; Lee, Sang-Hoon; Nam, Suk Woo; Oh, Il-Hoan; Lee, Jaehwi; Kuh, Hyo-Jeong

    2013-01-01

    Intrinsic drug resistance of pancreatic ductal adenocarcinoma (PDAC) warrants studies using models that are more clinically relevant for identifying novel resistance mechanisms as well as for drug development. Tumor spheroids (TS) mimic in vivo tumor conditions associated with multicellular resistance and represent a promising model for efficient drug screening, however, pancreatic cancer cells often fail to form spheroids using conventional methods such as liquid overlay. This study describes the induction of TS of human pancreatic cancer cells (Panc-1, Aspc-1, Capan-2) in concave polydimethylsiloxane (PDMS) microwell plates and evaluation of their usefulness as an anticancer efficacy test model. All three cell lines showed TS formation with varying degree of necrosis inside TS. Among these, Panc-1 spheroid with spherical morphology, a rather rough surface, and unique adhesion structures were successfully produced with no notable necrosis in concave microwell plates. Panc-1 TS contained growth factors or enzymes such as TGF-β1, CTGF, and MT1-MMP, and extracellular matrix proteins such as collagen type I, fibronectin, and laminin. Panc-1 cells grown as TS showed changes in stem cell populations and in expression levels of miRNAs that may play roles in chemoresistance. Visualization of drug penetration and detection of viability indicators, such as Ki-67 and MitoSOX, were optimized for TS for quantitative analysis. Water-soluble tetrazolium (MTS) and acid phosphatase (APH) assays were also successfully optimized. Overall, we demonstrated that concave PDMS microwell plates are a novel platform for preparation of TS of weakly aggregating cells and that Panc-1 spheroids may represent a novel three-dimensional model for anti-pancreatic cancer drug screening.

  1. Log-concave Probability Distributions: Theory and Statistical Testing

    DEFF Research Database (Denmark)

    An, Mark Yuing

    1996-01-01

    This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete and mul...

  2. Nearly unbiased variable selection under minimax concave penalty

    CERN Document Server

    Zhang, Cun-Hui

    2010-01-01

    We propose MC+, a fast, continuous, nearly unbiased and accurate method of penalized variable selection in high-dimensional linear regression. The LASSO is fast and continuous, but biased. The bias of the LASSO may prevent consistent variable selection. Subset selection is unbiased but computationally costly. The MC+ has two elements: a minimax concave penalty (MCP) and a penalized linear unbiased selection (PLUS) algorithm. The MCP provides the convexity of the penalized loss in sparse regions to the greatest extent given certain thresholds for variable selection and unbiasedness. The PLUS computes multiple exact local minimizers of a possibly nonconvex penalized loss function in a certain main branch of the graph of critical points of the penalized loss. Its output is a continuous piecewise linear path encompassing from the origin for infinite penalty to a least squares solution for zero penalty. We prove that at a universal penalty level, the MC+ has high probability of matching the signs of the unknowns, ...

  3. GNCCP-Graduated NonConvexityand Concavity Procedure.

    Science.gov (United States)

    Zhi-Yong Liu; Hong Qiao

    2014-06-01

    In this paper we propose the graduated nonconvexity and concavity procedure (GNCCP) as a general optimization framework to approximately solve the combinatorial optimization problems defined on the set of partial permutation matrices. GNCCP comprises two sub-procedures, graduated nonconvexity which realizes a convex relaxation and graduated concavity which realizes a concave relaxation. It is proved that GNCCP realizes exactly a type of convex-concave relaxation procedure (CCRP), but with a much simpler formulation without needing convex or concave relaxation in an explicit way. Actually, GNCCP involves only the gradient of the objective function and is therefore very easy to use in practical applications. Two typical related NP-hard problems, partial graph matching and quadratic assignment problem (QAP), are employed to demonstrate its simplicity and state-of-the-art performance.

  4. Laser micro-fabrication of concave, low-roughness features in silica

    CERN Document Server

    Hunger, David; Barbour, Russell J; Warburton, Richard J; Reichel, Jakob

    2011-01-01

    We describe a micro-fabrication method to create concave features with ultra-low surface roughness in silica, either on the end facets of optical fibers or on flat substrates. The machining uses a single focused CO2 laser pulse. Parameters are chosen such that material is removed by thermal evaporation while simultaneously producing excellent surface quality by surface tension-induced movement in a low-viscosity melt layer. A surface roughness {\\sigma}~0.2nm is regularly obtained. The concave depressions are near-spherical close to the center with radii of curvature between 20 and 2000{\\mu}m. The method allows the fabrication of low-scatter micro-optical devices such as mirror substrates for high-finesse cavities or negative lenses on the tip of optical fibers, extending the range of micro-optical components.

  5. Log-concavity property for some well-known distributions

    Directory of Open Access Journals (Sweden)

    G. R. Mohtashami Borzadaran

    2011-12-01

    Full Text Available Interesting properties and propositions, in many branches of science such as economics have been obtained according to the property of cumulative distribution function of a random variable as a concave function. Caplin and Nalebuff (1988,1989, Bagnoli and Khanna (1989 and Bagnoli and Bergstrom (1989 , 1989, 2005 have discussed the log-concavity property of probability distributions and their applications, especially in economics. Log-concavity concerns twice differentiable real-valued function g whose domain is an interval on extended real line. g as a function is said to be log-concave on the interval (a,b if the function ln(g is a concave function on (a,b. Log-concavity of g on (a,b is equivalent to g'/g being monotone decreasing on (a,b or (ln(g" 6] have obtained log-concavity for distributions such as normal, logistic, extreme-value, exponential, Laplace, Weibull, power function, uniform, gamma, beta, Pareto, log-normal, Student's t, Cauchy and F distributions. We have discussed and introduced the continuous versions of the Pearson family, also found the log-concavity for this family in general cases, and then obtained the log-concavity property for each distribution that is a member of Pearson family. For the Burr family these cases have been calculated, even for each distribution that belongs to Burr family. Also, log-concavity results for distributions such as generalized gamma distributions, Feller-Pareto distributions, generalized Inverse Gaussian distributions and generalized Log-normal distributions have been obtained.

  6. Exceptional methanol electro-oxidation activity by bimetallic concave and dendritic Pt-Cu nanocrystals catalysts

    Science.gov (United States)

    Wang, Ying-Xia; Zhou, Hui-Jing; Sun, Ping-Chuan; Chen, Tie-Hong

    2014-01-01

    PtCux (x = 1, 2 and 3) bimetallic nanocrystals with concave surface and dendritic morphology were prepared and used as electrocatalysts in methanol oxidation reaction (MOR) for polymer electrolyte membrane fuel cells. The bimetallic nanocrystals were synthesized via one-pot co-reduction of H2PtCl6 and Cu(acac)2 by oleylamine and polyvinyl pyrrolidone (PVP) in an autoclave at 180 °C. The concave dendritic bimetallic nanostructure consisted of a core rich in Cu and nanodendrites rich in Pt, which was formed via galvanic replacement of Cu by Pt. It was found that PVP played an important role in initiating, facilitating, and directing the replacement reaction. The electrochemical properties of the PtCux were characterized by cyclic voltammetry (CV) and chronoamperometry (CA). The concave dendritic PtCu2/C nanocrystals exhibited exceptionally high activity and strong poisoning resistance in MOR. At 0.75 V (vs. reversible hydrogen electrode, RHE) the mass activity and specific activity of PtCu2/C were 3.3 and 4.1 times higher than those of the commercial Pt/C catalysts, respectively. The enhanced catalytic activity could be attributed to the unique concave dendritic morphology of the bimetallic nanocrystals.

  7. Laser micro-fabrication of concave, low-roughness features in silica

    Directory of Open Access Journals (Sweden)

    D. Hunger

    2012-03-01

    Full Text Available We describe a micro-fabrication method to create concave features with ultra-low roughness in silica, either on optical fibers or on flat substrates. The machining uses a single CO2 laser pulse train. Parameters are chosen such that evaporation removes material while a low-viscosity melt layer produces excellent surface quality. A surface roughness σ ∼ 0.2 nm is regularly obtained. The concave depressions are near-spherical close to the center with radii of curvature between 20 and 2000 μm. The method allows fabrication of low-scatter micro-optical devices such as mirror substrates for high-finesse cavities or negative lenses on fiber tips, extending the range of micro-optical components.

  8. Generalized concavity in fuzzy optimization and decision analysis

    CERN Document Server

    Ramík, Jaroslav

    2002-01-01

    Convexity of sets in linear spaces, and concavity and convexity of functions, lie at the root of beautiful theoretical results that are at the same time extremely useful in the analysis and solution of optimization problems, including problems of either single objective or multiple objectives. Not all of these results rely necessarily on convexity and concavity; some of the results can guarantee that each local optimum is also a global optimum, giving these methods broader application to a wider class of problems. Hence, the focus of the first part of the book is concerned with several types of generalized convex sets and generalized concave functions. In addition to their applicability to nonconvex optimization, these convex sets and generalized concave functions are used in the book's second part, where decision-making and optimization problems under uncertainty are investigated. Uncertainty in the problem data often cannot be avoided when dealing with practical problems. Errors occur in real-world data for...

  9. Log-concave Probability Distributions: Theory and Statistical Testing

    DEFF Research Database (Denmark)

    An, Mark Yuing

    1996-01-01

    This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete...... and multivariate distributions are also discussed. We propose simple non-parametric testing procedures for log-concavity. The test statistics are constructed to test one of the two implicati ons of log-concavity: increasing hazard rates and new-is-better-than-used (NBU) property. The test for increasing hazard...... rates are based on normalized spacing of the sample order statistics. The tests for NBU property fall into the category of Hoeffding's U-statistics...

  10. Classroom Note: Concavity and the Second Law of Thermodynamics

    Science.gov (United States)

    Dunning-Davies, J.

    2003-01-01

    The importance of the mathematical notion of concavity in relation to thermodynamics is stressed and it is shown how it can be useful in increasing the enthusiasm of physics' students for their mathematics' courses.

  11. Double Pyramidal Central Configurations with a Concave Quadrilateral Base

    Institute of Scientific and Technical Information of China (English)

    LIUXuefei

    2002-01-01

    As for a doudle pyramidal central configuration in 6-body problems,the case when its bese is a concave polygon is studied.By advancing several assumptions according to the definition of double pyramidal central configuration and deducing two theorems and two corollaries on this subject,the essential and sufficient conditions to form a double pyramidal central configuration with a concave quadriateral base are demonstrated.

  12. The Tucker technique: the proximal hollow grind to address a root concavity.

    Science.gov (United States)

    Hess, T A

    2014-01-01

    Cast gold inlays have long been used to conservatively restore compromised tooth structure. When the mesial or distal proximal surfaces are indicated for restoration and a cast gold restoration is desired, traditionally a box is prepared with an external bevel. Often a root concavity does not allow for a standard box form or the external and/or internal bevels. A proximal hollow grind can be utilized to address limits of standard inlay or onlay preparation design.

  13. Integration of polystyrene microlenses with both convex and concave profiles in a polymer-based microfluidic system

    KAUST Repository

    Fan, Yiqiang

    2013-12-20

    This paper reports a new technique of fabricating polystyrene microlenses with both convex and concave profiles that are integrated in polymer-based microfluidic system. The polystyrene microlenses, or microlens array, are fabricated using the free-surface thermal compression molding method. The laser fabricated poly(methyl methacrylate) (PMMA) sheet is used as the mold for the thermal compression molding process. With different surface treatment methods of the PMMA mold, microlenses with either convex or concave profiles could be achieved during the thermal molding process. By integrating the microlenses in the microfluidic systems, observing the flow inside the microchannels is easier. This new technique is rapid, low cost, and it does not require cleanroom facilities. Microlenses with both convex and concave profiles can be easily fabricated and integrated in microfluidic system with this technique. © 2013 Springer-Verlag Berlin Heidelberg.

  14. Surface-to-surface registration using level sets

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Erbou, Søren G.; Vester-Christensen, Martin;

    2007-01-01

    This paper presents a general approach for surface-to-surface registration (S2SR) with the Euclidean metric using signed distance maps. In addition, the method is symmetric such that the registration of a shape A to a shape B is identical to the registration of the shape B to the shape A. The S2S...

  15. A Simple Universal Generator for Continuous and Discrete Univariate T-concave Distributions

    OpenAIRE

    Leydold, Josef

    2000-01-01

    We use inequalities to design short universal algorithms that can be used to generate random variates from large classes of univariate continuous or discrete distributions (including all log-concave distributions). The expected time is uniformly bounded over all these distributions. The algorithms can be implemented in a few lines of high level language code. In opposition to other black-box algorithms hardly any setup step is required and thus it is superior in the changing parameter case. (...

  16. Uniform Magnetic Field Between Face-to-Face HTS Bulk Magnets Combining Concave and Convex Magnetic Field Distributions

    Science.gov (United States)

    Oka, T.; Takahashi, Y.; Yaginuma, S.; Ogawa, J.; Fukui, S.; Sato, T.; Yokoyama, K.; Nakamura, T.

    The authors have been attempting to obtain the uniform magnetic field distribution in the space between the face-to-face HTS bulk magnets. The magnetic poles containing the HTS bulk magnets are usually characterized as non-uniform magnetic field distribution. Since the distributions show the conical or convex shapes, it is difficult to obtain the uniform magnetic field spaces even when the magnetic poles would be placed face-to-face. The authors have modified the shape of the distribution of one-side magnetic pole by attaching an iron plate on the surface, and formed the concave magnetic field distribution on the pole surface. The steep concave or convex distributions at each pole surface change to be flat with increasing distance from the pole surface. After the experimental result recording the best uniformity of 358 ppm by combining the concave and convex field distributions face-to-face, we attempted to simulate the feasible performance in this configuration. In the numerical simulation, the concave field distribution modified by attaching an imaginary spiral coil on the pole surface was coupled with the original convex field. We succeeded in obtaining the best uniformity of 30 ppm at 1.1 T in 4 x 4 mm2x-y plane at 7 mm distant from the pole surface in the gap of 30 mm. This result suggests that the concave and convex magnetic field distributions compensate the field uniformity with each other with keeping the magnetic field strength in the gap, and also suggests the novel compact NMR/MRI devices in the future.

  17. Anterior Shoulder Instability Is Associated With an Underlying Deficiency of the Bony Glenoid Concavity.

    Science.gov (United States)

    Moroder, Philipp; Ernstbrunner, Lukas; Pomwenger, Werner; Oberhauser, Florian; Hitzl, Wolfgang; Tauber, Mark; Resch, Herbert; Moroder, Rudi

    2015-07-01

    To determine whether anterior shoulder instability is associated with an inherent deficiency of the bony glenoid concavity, which results in a reduced bony shoulder stability ratio (BSSR). In this case-control study, we searched the institutional database for patients treated for unilateral recurrent anterior shoulder instability. We included 30 consecutive patients with atraumatic instability, 30 consecutive patients with traumatic instability, and 36 matched healthy controls, for a total of 96 shoulders. Computed tomography images of the unaffected shoulders of the instability patients were compared with images of the ipsilateral shoulders of age- and sex-matched healthy controls for differences in glenoid morphology. By use of a mathematical formula based on Pythagorean trigonometric identities, the mean BSSRs of the different groups were calculated and compared. Validation of the formula was accomplished by finite element analysis. The mean BSSR of atraumatic instability patients was 17.9% ± 8.5% and therefore significantly lower than the mean BSSR of 31.1% ± 7.5% of the control group (13.2%; 95% confidence interval [CI], 9.1% to 17.4%; P < .001). The mean BSSR of the traumatic instability group was higher, at 23.9% ± 8.5% (P = .007), but still showed a deficit of 7.2% (95% CI, 2.8% to 11.7%; P = .002) compared with controls. The atraumatic instability group showed a mean reduction of 0.9 mm (95% CI, 0.6 to 1.1 mm; P < .001) in concavity depth and a decrease of 2.9° (95% CI, 0.4° to 5.3°; P = .021) in concavity retroversion, whereas the traumatic instability patients had a reduction of 0.4 mm (95% CI, 0.1 to 0.8 mm; P = .006) in concavity depth. Neither of the instability groups differed significantly from their respective controls in terms of glenoid concavity diameter, head radius, or glenoid vault morphology. Anterior shoulder instability is associated with an inherent flattening of the bony glenoid concavity, which significantly decreases the

  18. Inviscid Uniform Shear Flow past a Smooth Concave Body

    Directory of Open Access Journals (Sweden)

    Abdullah Murad

    2014-01-01

    Full Text Available Uniform shear flow of an incompressible inviscid fluid past a two-dimensional smooth concave body is studied; a stream function for resulting flow is obtained. Results for the same flow past a circular cylinder or a circular arc or a kidney-shaped body are presented as special cases of the main result. Also, a stream function for resulting flow around the same body is presented for an oncoming flow which is the combination of a uniform stream and a uniform shear flow. Possible fields of applications of this study include water flows past river islands, the shapes of which deviate from circular or elliptical shape and have a concave region, or past circular arc-shaped river islands and air flows past concave or circular arc-shaped obstacles near the ground.

  19. A Hybrid Dynamic Programming Method for Concave Resource Allocation Problems

    Institute of Scientific and Technical Information of China (English)

    姜计荣; 孙小玲

    2005-01-01

    Concave resource allocation problem is an integer programming problem of minimizing a nonincreasing concave function subject to a convex nondecreasing constraint and bounded integer variables. This class of problems are encountered in optimization models involving economies of scale. In this paper, a new hybrid dynamic programming method was proposed for solving concave resource allocation problems. A convex underestimating function was used to approximate the objective function and the resulting convex subproblem was solved with dynamic programming technique after transforming it into a 0-1 linear knapsack problem. To ensure the convergence, monotonicity and domain cut technique was employed to remove certain integer boxes and partition the revised domain into a union of integer boxes. Computational results were given to show the efficiency of the algorithm.

  20. Log-concavity of the genus polynomials of Ringel Ladders

    Directory of Open Access Journals (Sweden)

    Jonathan L Gross

    2015-10-01

    Full Text Available A Ringel ladder can be formed by a self-bar-amalgamation operation on a symmetric ladder, that is, by joining the root vertices on its end-rungs. The present authors have previously derived criteria under which linear chains of copies of one or more graphs have log-concave genus polyno- mials. Herein we establish Ringel ladders as the first significant non-linear infinite family of graphs known to have log-concave genus polynomials. We construct an algebraic representation of self-bar-amalgamation as a matrix operation, to be applied to a vector representation of the partitioned genus distribution of a symmetric ladder. Analysis of the resulting genus polynomial involves the use of Chebyshev polynomials. This paper continues our quest to affirm the quarter-century-old conjecture that all graphs have log-concave genus polynomials.

  1. Near concavity of the growth rate for coupled LDPC chains

    CERN Document Server

    Hassani, S Hamed; Mori, Ryuhei

    2011-01-01

    Convolutional Low-Density-Parity-Check (LDPC) ensembles have excellent performance. Their iterative threshold increases with their average degree, or with the size of the coupling window in randomized constructions. In the later case, as the window size grows, the Belief Propagation (BP) threshold attains the maximum-a-posteriori (MAP) threshold of the underlying ensemble. In this contribution we show that a similar phenomenon happens for the growth rate of coupled ensembles. Loosely speaking, we observe that as the coupling strength grows, the growth rate of the coupled ensemble comes close to the concave hull of the underlying ensemble's growth rate. For ensembles randomly coupled across a window the growth rate actually tends to the concave hull of the underlying one as the window size increases. Our observations are supported by the calculations of the combinatorial growth rate, and that of the growth rate derived from the replica method. The observed concavity is a general feature of coupled mean field g...

  2. Technology for fabricating micro-lens arrays utilizing lithographically replicated concave resist patterns

    Science.gov (United States)

    Kobayashi, Noa; Sasaki, Ryunosuke; Horiuchi, Toshiyuki

    2016-05-01

    Lithography has been generally used for printing two-dimensional patterns on flat wafers. Recently, however, it is also applied to a three-dimensional patterning for fabricating various MEMS (Micro Electro Mechanical Systems) components. The purpose of this research is to develop a new method for fabricating micro-lens arrays. At first, resist (Tokyo Ohka Kogyo, PMER LA-900PM) mold patterns with densely arrayed square or hexagonal concaves were replicated by intentionally shifting the focal position of projection exposure. The size of resist-mold was 2 mm square, and the initial thickness of the resist was 10 μm. Next, the wafer with the concave resist patterns was cut into small chips, and each wafer chip was fixed at the bottom of a paper cup using an adhesive tape. Then the epoxy resin (Nissin resin, Crystal resin Neo) was poured on the concave resist-mold patterns, and the resin was coagulated. Afterward, the hardened resin was grooved along the wafer chip using a cutter knife, and the wafer chip with the resist-mold patterns was forcibly removed using a pair of tweezers. Finally, both sides of the resin block were polished, and the thickness was reduced. Although the transparency and roughness of the resin block surfaces should be improved, epoxy micro-lens arrays were certainly fabricated. The mean values of curvature radius and lens height were 28.3μm and 4.9 μm, respectively.

  3. Universal tectonic dichotomy of small celestial bodies expressed in their common convexo-concave shapes

    Science.gov (United States)

    Kochemasov, G. G.

    2008-09-01

    The wave planetology [1, 2, 3 & others] declares in its first theorem that all celestial bodies are dichotomous. This is a result of a warping action of the fundamental wave (wave 1 long 2πR where R is a body radius) that appears in any body due to its movement in non-round (elliptical, parabolic) keplerian orbits with periodically changing accelerations. Having a standing character and four crossing directions in rotating bodies (but all bodies rotate!) these waves inevitably press in one hemisphere and bulge out the opposite one tending to impose on a body convexo-concave shape. This shape is leveled out in larger bodies due to enhanced gravity but is clearly observed in smaller ones with diminished gravity. Still, in the larger bodies as, for an example, in Earth the tectonic dichotomy is expressed as an opposition of the subsided western Pacific hemisphere and the uplifted eastern continental hemisphere. At Mars even sharper dichotomy is in the north-south direction. Small bodies (normally less than 400-500 km across) notwithstanding their type (asteroids, comets, satellites), size and composition (stones, metals, ices) are flattened and bended by the fundamental wave. That is why all asteroids in the main asteroid belt have an oblong shape what was established rather long ago but never was properly explained. Now a number of small satellites is observed by Cassini spacecraft in the saturnian system that makes together with jovian and martian small satellites a representative group for comparisons. In the figures below are shown asteroids, satellites and a comet arranged in a row of increasing sizes. They all are flattened except the largest in the row Enceladus (505 km) and bended tending to acquire a convexo-concave shape. Asteroids: Itokawa (0.5 km long), Eros (33 km, PIA03111). Satellites: Calypso (22 km, PIA07633), Atlas (32 km, PIA08233), Prometheus (102 km, PIA08192), Hyperion (350 km, PIA06645), Enceladus (505 km, PIA08258, comet-like behaviour). Comet

  4. A BRANCH AND BOUND ALGORITHM FOR SEPARABLE CONCAVE PROGRAMMING

    Institute of Scientific and Technical Information of China (English)

    Hong-gang Xue; Cheng-xian; Feng-min Xu

    2004-01-01

    In this paper, we propose a new branch and bound algorithm for the solution of large scale separable concave programming problems. The largest distance bisection (LDB)technique is proposed to divide rectangle into sub-rectangles when one problem is branched into two subproblems. It is proved that the LDB method is a normal rectangle subdivision(NRS). Numerical tests on problems with dimensions from 100 to 10000 show that the proposed branch and bound algorithm is efficient for solving large scale separable concave programming problems, and convergence rate is faster than ω-subdivision method.

  5. Evaluation of the levels of phthalate ester plasticizers in surface ...

    African Journals Online (AJOL)

    Evaluation of the levels of phthalate ester plasticizers in surface water of Ethiope River System, Delta State, Nigeria. ... studies of the river. Keywords: phthalates, acid esters, plasticizers, Ethiope River, surface water, pollution ... Article Metrics.

  6. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, Berend; Schumacher, Johannes M.

    2016-01-01

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal repr

  7. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, B.; Schumacher, Hans

    2016-01-01

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal repre

  8. Local matching indicators for transport problems with concave costs

    CERN Document Server

    Delon, Julie; Sobolevskii, Andrei

    2011-01-01

    In this paper, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of N demands and M supplies in R in the case where the cost function is concave. The computational cost of these indicators is small and independent of N. A hierarchical use of them enables to obtain an efficient algorithm.

  9. Concavity of Solutions of the Porous Medium Equation.

    Science.gov (United States)

    1985-08-01

    R x (0,T), for initial data not necessarily concave. She obtains results about existence, uniqueness and nonuniqueness for suitable classes of weak... Lipschitz -continuous curves (the interfaces), si(o) = a, s2(0) = b, and (-1) isi(t) is nondecreasing in time. Along the interfaces the derivative vx is

  10. Fault-tolerant Concave Facility Location Problem with Uniform Requirements

    Institute of Scientific and Technical Information of China (English)

    Xing WANG; Da-Chuan XU; Zheng-Hai HUANG

    2012-01-01

    In this paper,we consider the fault-tolerant concave facility location problem (FTCFL) with uniform requirements. By investigating the structure of the FTCFL,we obtain a modified dual-fitting bifactor approximation algorithm.Combining the scaling and greedy argumentation technique,the approximation factor is proved to be 1.52.

  11. COMPUTATION OF NONEQUILIBRIUM HYPERSONIC FLOW OVER CONCAVE CORNERS

    Institute of Scientific and Technical Information of China (English)

    Taehoon Park; You-lan Zhu

    2001-01-01

    This paper is devoted to computation of hypersonic flow of air with chemical reactions over concave corners. A technique combining smooth transformation of domain and implicit difference methods is used to overcome numerical difficulties associated with the lack of resolution behind the shock and near the body. The implicit treatment of right hand side terms is also an important part of our method.

  12. Existence of orthogonal geodesic chords on Riemannian manifolds with concave boundary and homeomorphic to the N-dimensional disk

    CERN Document Server

    Giambo', R; Piccione, P

    2010-01-01

    In this paper we give a proof of the existence of an orthogonal geodesic chord on a Riemannian manifold homeomorphic to a closed disk and with concave boundary. This kind of study is motivated by the link of the multiplicity problem with the famous Seifert conjecture (formulated in 1948) about multiple brake orbits for a class of Hamiltonian systems at a fixed energy level.

  13. Probing Surface Chemistry at the Nanoscale Level

    Science.gov (United States)

    Rene-Boisneuf, Laetitia

    Studies various nanostructured materials have gained considerable interest within the past several decades. This novel class of materials has opened up a new realm of possibilities, both for the fundamental comprehension of matter, but also for innovative applications. The size-dependent effect observed for these systems often lies in their interaction with the surrounding environment and understanding such interactions is the pivotal point for the investigations undertaken in this thesis. Three families of nanoparticles are analyzed: semiconductor quantum dots, metallic silver nanoparticles and rare-earth oxide nanomaterials. The radical scavenging ability of cerium oxide nanoparticles (CeO 2) is quite controversial since they have been labeled as both oxidizing and antioxidant species for biological systems. Here, both aqueous and organic stabilized nanoparticles are examined in straightforward systems containing only one reactive oxygen species to ensure a controlled release. The apparent absence of their direct radical scavenging ability is demonstrated despite the ease at which CeO2 nanoparticles generate stable surface Ce 3+ clusters, which is used to explain the redox activity of these nanomaterials. On the contrary, CeO2 nanoparticles are shown to have an indirect scavenging effect in Fenton reactions by annihilating the reactivity of Fe 2+ salts. Cadmium selenide quantum dots (CdSe QD) constitute another highly appealing family of nanocolloids in part due to their tunable, size-dependent luminescence across the visible spectrum. The effect of elemental sulfur treatment is investigated to overcome one of the main drawbacks of CdSe QD: low fluorescence quantum yield. Herein, we report a constant and reproducible quantum yield of 15%. The effect of sulfur surface treatment is also assessed following the growth of a silica shell, as well as the response towards a solution quencher (4-amino-TEMPO). The sulfur treated QD is also tested for interaction with

  14. A New Method for Machining Concave Profile of the Worms' Thread

    Directory of Open Access Journals (Sweden)

    Tareq Abu Shreehah

    2010-09-01

    Full Text Available Research and development of wormgear drives have significantly focused on their geometrical accuracy, loadability tests, and their wear resistance and efficiency. The research has been going on in several directions. Individual method of problem solving is development new worm-gear sets and tools for their manufacturing. In the present study, worms with concave profile of their thread have been considered. To avoid the technological difficulties relevant to the application of special cutting tools for machining such gear sets, a rigid incongruent generating pair consisting of a standard hob and toroidal tool has been developed for processing the concave worm profile. The generating surface of the developed toroidal tool, which is essential for the tool manufacturing, was modeled on the basis of hob-toroidal tool interaction. The proposed method of modeling w as divided into three steps: first, the common surface for both hobbing and toroidal tools has been found in terms of hyperboloid of revolution of one sheet, then, the matrix method of transforming the coordinates, from the hob-axis reference frame to the toroidal tool-axis reference frame, has been utilized, and finally, an equation described the generating surface of the toroidal tool has been derived and presented. By using the proposed model and the obtained final equation the worm thread surface machined by the mentioned tool can be defined and experimented.

  15. Curvature morphology of the mandibular dentition and the development of concave-convex vertical stripping instruments.

    Science.gov (United States)

    Ihlow, Dankmar; Kubein-Meesenburg, Dietmar; Hunze, Justus; Dathe, Henning; Planert, Jens; Schwestka-Polly, Rainer; Nägerl, Hans

    2002-07-01

    Radii for concave-convex vertical stripping instruments can be derived from measurements of the natural curvature morphology in the horizontal contact area of the mandibular dentition. The concave-convex adjustment of contacts in the anterior dental arch with a newly developed set of concave-convex stripping instruments should enable orthodontic crowding problems to be alleviated biomechanically.

  16. Smoothed log-concave maximum likelihood estimation with applications

    CERN Document Server

    Chen, Yining

    2011-01-01

    We study the smoothed log-concave maximum likelihood estimator of a probability distribution on $\\mathbb{R}^d$. This is a fully automatic nonparametric density estimator, obtained as a canonical smoothing of the log-concave maximum likelihood estimator. We demonstrate its attractive features both through an analysis of its theoretical properties and a simulation study. Moreover, we show how the estimator can be used as an intermediate stage of more involved procedures, such as constructing a classifier or estimating a functional of the density. Here again, the use of the estimator can be justified both on theoretical grounds and through its finite sample performance, and we illustrate its use in a breast cancer diagnosis (classification) problem.

  17. Negative time delay of light by a gravitational concave lens

    CERN Document Server

    Nakajima, Koki; Asada, Hideki

    2014-01-01

    Gravitational lens models, some of which might act as if a concave lens, have been recently investigated by using a static and spherically symmetric modified spacetime metric that depends on the inverse distance to the $n$-th power [Kitamura, Nakajima and Asada, PRD 87, 027501 (2013)]. We reexamine the time delay of light in a gravitational concave lens as well as a gravitational convex one. The frequency shift due to the time delay is also investigated. We show that the sign of the time delay in the lens models is the same as that of the deflection angle of light. The size of the time delay decreases with increase in the parameter $n$. We discuss also possible parameter ranges that are relevant to pulsar timing measurements in our galaxy.

  18. Miniature anastigmatic spectrometer design with a concave toroidal mirror.

    Science.gov (United States)

    Dong, Jianing; Chen, He; Zhang, Yinchao; Chen, Siying; Guo, Pan

    2016-03-01

    An advanced optical design for a low-cost and astigmatism-corrected spectrometer with a high resolution is presented. The theory and method of astigmatism correction are determined with the use of a concave toroidal mirror. The performances of a modified spectrometer and a traditional spectrometer are compared, and the analysis is verified. Experimentally, the limiting resolution of our spectrometer is 0.1 nm full width at half-maximum, as measured for 579.1 nm.

  19. New progress on acoustic communication in the concave-eared torrent frog and its revelation

    Institute of Scientific and Technical Information of China (English)

    Shen Junxian

    2007-01-01

    Animals have special solution to the problem of communication in high levels of background noise.A small group of vertebrates (bats, dolphins and whales, and some rodents) that use ultrasound for communication. Our research first demonstrated that the concave-eared torrent frog is the first nonmammalian vertebrate found to be capable of producing and detecting ultrasounds for communication. This study may provide a clue for understanding why humans have ear canals and how animals auditory systems have evolved, and inspire in developing bionic tecnology for improving hearing in noise.

  20. Level curve cutting of NURBS-approximated free formed surfaces

    Science.gov (United States)

    Schoene, Rene; Zimmermann, Alexander; Hanning, Tobias

    2005-06-01

    The requirements of optical surfaces are increasing with respect to their functionality and accuracy of form. Furthermore, it is a goal for the optical industry to unify the lens process from development to production. In our phase of design we have an arbitrary set of 3D-points of a free formed surface. With approximation through NURBS, we get a continuous description of this surface. To the generated NURB-Spline, we have developed a CNC-program for the UPM-3000 machine, which drives the cutter along the level curve. Therefore, we triangulate the NURBS-surface. By the desired accuracy and the generated triangles, we determine levels of the surface. Thus, we refine the given triangulation. Hence we have a triangular decomposition for each level, which will be driven along by the cutter. The described method will be compared to the common raster-fly-cut-method for accuracy and cutting time.

  1. 3D Surface Editing Based on Level-Sets

    Institute of Scientific and Technical Information of China (English)

    Lin Maosong; Zhang Dianhua

    2005-01-01

    A novel method which integrates the topological flexibility of the level-set approach and the simphcity of point-sampled surfaces is proposed. The grid structure resulted from the level-set approach not only offers a wide range of powerful surface editing techniques for the point set surface editing, but also facilitates the topological change with ease. With the aid of point-based resampling,the method updates the surface shape of the point-based geometry quickly without worrying about point connectivity at all. The point set surface can also change its topology properly whenever a collision with other parts of itself is detected. The experiment demonstrates their effectiveness on several scanned objects and scan-converted models. Four examples of surface editing operations: smoothing, tapering, deforming, and Boolean operations, are presented.

  2. MISR Level 2 FIRSTLOOK Surface parameters V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This Level 2 FIRSTLOOK Land Surface product contains directional reflectance properties,albedo(spectral to study, on a global basis,the magnitude and natural...

  3. The surface core level shift for lithium at the surface of lithium borate

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, David [Air Force Institute of Technology, 2950 Hobson Way, Wright Patterson Air Force Base, OH 45433-7765 (United States); Ketsman, I.; Xiao, Jie [Department of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, P.O. Box 880111, Lincoln, NE 68588-0111 (United States); Losovyj, Ya.B. [Department of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, P.O. Box 880111, Lincoln, NE 68588-0111 (United States); J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Petrosky, J.; McClory, J. [Air Force Institute of Technology, 2950 Hobson Way, Wright Patterson Air Force Base, OH 45433-7765 (United States); Burak, Ya.V.; Adamiv, V.T. [Institute of Physical Optics, Dragomanov 23, Lviv 79005 (Ukraine); Dowben, P.A., E-mail: pdowben@unl.ed [Department of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, P.O. Box 880111, Lincoln, NE 68588-0111 (United States)

    2010-01-01

    The shallow Li 1s core level exhibits a surface-to-bulk core level shift for the stoichiometric Li{sub 2}B{sub 4}O{sub 7}(1 1 0) surface. Angle-resolved photoemission spectroscopy was used to indentify Li 1s bulk and surface core level components at binding energies -56.5+-0.4 and -53.7+-0.5 eV, respectively. We find photoemission evidence for surface states of Li{sub 2}B{sub 4}O{sub 7}(1 1 0) that exist in the gap of the projected bulk density of states. The existence of surface states is consistent with the large surface-to-bulk core level shift for the Li 1s core.

  4. Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

    Institute of Scientific and Technical Information of China (English)

    余立立; 寿文德; 惠春

    2012-01-01

    A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov-Zabolotskaya-Kuznetsov (KZK) model, respectively. Axia/dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field.

  5. Surface core-level shifts for Pt single-crystal surfaces

    Science.gov (United States)

    Baetzold, R. C.; Apai, G.; Shustorovich, E.; Jaeger, R.

    1982-10-01

    The (111) and (110) surfaces of Pt, clean, oxidized, and covered by CO, have been investigated for surface 4f core-level binding-energy shifts. For the (111) face the surface Pt4f72 core level was shifted by 0.40+/-0.05 eV to lower binding energy relative to the bulk peak. On the (110)-(1×2) reconstructed surface similarly shifted peaks at 0.21+/-0.05 and 0.55+/-0.05 eV were observed. Chemisorbed carbon monoxide shifts the Pt(111) surface-related core level by 1.3 eV to higher binding energy. Formation of subsurface oxygen did not produce changes in the Pt(111)4f72 core-level binding energies. The results obtained are explained and their possible implications are discussed.

  6. Effect of surface charge on hydrophobicity levels of insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Villa, V.M.; Ponce-Velez, M.A.; Valle-Jaime, E.; Fierro-Chavez, J.L. [Instituto de Investigaciones Electricas, Mor (Mexico). Unidad de Materiales Electricos

    1998-11-01

    A correlation between the hydrophobic characteristics and accumulation of static charge on several insulating surfaces (ceramic and non- ceramic) is studied. Although numerous experimental studies on the loss and recovery of hydrophobicity on insulator surfaces have been carried out, no efforts for establishing a correlation between such hydrophobic properties and the presence of surface charge have yet been made, especially when attention is paid to ceramic surfaces. This experiment consists of simultaneous measurements of surface charge decay and contact angle recovery against time on samples previously exposed to corona impingement; a comparison between charge decay and hydrophobicity recovery trends is then made. From the data obtained, a lowering of the original hydrophobicity level for each material as a consequence of surface charge accumulation is identified. The decay of surface charge and the corresponding recovery of the initial hydrophobic characteristics with time are observed. Loss and recovery of hydrophobicity resulting from surface charging and charge decay, respectively, are identified as mechanisms occurring not only on polymeric surfaces, but also on ceramic ones. From a number of laboratory studies it has been confirmed, and extensively reported by several researchers, that surface charging of insulators due to electrical activity (partial discharging) can be achieved. Based on the above, as well as on the results obtained from this experimental work, surface charging of insulators is a phenomenon which may occur under realistic operational conditions, and is therefore proposed as a factor responsible for the loss of the initial highly hydrophobic characteristics of polymeric insulators and coatings, in addition to other well established mechanisms. (author)

  7. Confidence sets for optimal factor levels of a response surface.

    Science.gov (United States)

    Wan, Fang; Liu, Wei; Bretz, Frank; Han, Yang

    2016-12-01

    Construction of confidence sets for the optimal factor levels is an important topic in response surfaces methodology. In Wan et al. (2015), an exact (1-α) confidence set has been provided for a maximum or minimum point (i.e., an optimal factor level) of a univariate polynomial function in a given interval. In this article, the method has been extended to construct an exact (1-α) confidence set for the optimal factor levels of response surfaces. The construction method is readily applied to many parametric and semiparametric regression models involving a quadratic function. A conservative confidence set has been provided as an intermediate step in the construction of the exact confidence set. Two examples are given to illustrate the application of the confidence sets. The comparison between confidence sets indicates that our exact confidence set is better than the only other confidence set available in the statistical literature that guarantees the (1-α) confidence level. © 2016, The International Biometric Society.

  8. Surface characterization of commercial oral implants on the nanometer level.

    Science.gov (United States)

    Svanborg, Lory Melin; Andersson, Martin; Wennerberg, Ann

    2010-02-01

    Lately, there has been a growing interest in how the presence of nanometer structures on a bone integrated implant surface influences the healing process. Recent in vitro studies have revealed an increased osteoblast response to different nanophase surfaces. Some commercial implant brands claim their implants have nanometer structures. However, at present, there are no studies where the nano topography of today's commercially available oral implants has been investigated. The aim of this study was to characterize commercial oral implants on the nanometer level and to investigate whether or not the nanometer surface roughness was correlated to the more well-known micrometer roughness on the implants. Twelve different commercial screw-shaped oral implants with various surface modifications were examined using scanning electron microscopy and a white light interferometer. The interferometer is suitable for detection of nanoscale roughness in the vertical dimension; however, limitation exists on the horizontal due to the wavelength of the light. A 1 x 1 microm Gaussian filter was found to be useful for identifying nm roughness with respect to height deviation. The results demonstrated that an implant that was smooth on the micrometer level was not necessarily smooth on the nanometer level. Different structures in the nanometer scale was found on some of the implants, indicating that to fully understand the relationship between the properties of an implant surface and its osseointegration behavior, a characterization at the nanometer scale might be relevant.

  9. Origin of metallic surface core-level shifts

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Abrikosov, I. A.

    1995-01-01

    The unique property of the open 4f energy shell in the lanthanide metals is used to show that the initial-state energy shift gives an insufficient description of surface core-level shifts. Instead a treatment, which fully includes the final-state screening, account for the experimentally observed...

  10. SMAP Level 4 Surface and Root Zone Soil Moisture

    Science.gov (United States)

    Reichle, R.; De Lannoy, G.; Liu, Q.; Ardizzone, J.; Kimball, J.; Koster, R.

    2017-01-01

    The SMAP Level 4 soil moisture (L4_SM) product provides global estimates of surface and root zone soil moisture, along with other land surface variables and their error estimates. These estimates are obtained through assimilation of SMAP brightness temperature observations into the Goddard Earth Observing System (GEOS-5) land surface model. The L4_SM product is provided at 9 km spatial and 3-hourly temporal resolution and with about 2.5 day latency. The soil moisture and temperature estimates in the L4_SM product are validated against in situ observations. The L4_SM product meets the required target uncertainty of 0.04 m(exp. 3)m(exp. -3), measured in terms of unbiased root-mean-square-error, for both surface and root zone soil moisture.

  11. GABA and GABA receptors alterations in the primary visual cortex of concave lens-induced myopic model.

    Science.gov (United States)

    Zhao, Wen; Bi, Ai-Ling; Xu, Chao-Li; Ye, Xiang; Chen, Mei-Qing; Wang, Xin-Ting; Zhang, Xiao-Yan; Guo, Jun-Guo; Jiang, Wen-Jun; Zhang, Jin; Bi, Hong-Sheng

    2017-02-02

    Until recently most researches on myopia mechanisms have mainly been focused on the eye ball and few investigations were explored on the upper visual pathway, such as the visual cortex. The roles of gamma-aminobutyric acid (GABA) in the retinal and in the upper visual pathway are inter-correlated. As the retinal glutamate decarboxylase (GAD), GABA, and the mRNA levels of GABA receptors increased during the concave lens induced myopia formation, however, whether GABA alterations also occurred in the visual cortex during the concave lens induction is still unknown. In the present study, using HPLC, Enzyme-Linked Immunosorbent Assay (ELISA) and Real-Time Quantitative-PCR (RT-PCR) methods, we observed the changing trends of GABA, glutamate decarboxylase (GAD), and GABA receptors in the visual cortex of concave lens-induced myopic guinea pigs. Similar to the changing patterns of retinal GABA, the concentrations of GAD, GABA and the mRNA levels of GABA receptors in the visual cortex also increased. These results indicate that the exploration on myopia mechanisms should possibly be investigated on the whole visual pathway and the detailed significance of cortical GABA alterations needs further investigation.

  12. Tailoring Thermal Radiative Properties with Film-Coupled Concave Grating Metamaterials

    CERN Document Server

    Wang, Hao

    2014-01-01

    This work numerically investigates the radiative properties of film-coupled metamaterials made of a two-dimensional metallic concave grating on a continuous metal film separated by an ultrathin dielectric spacer. Spectrally-selective absorption is demonstrated in the visible and near-infrared regime, and underlying mechanisms are elucidated to be either localized magnetic polaritons (MPs) or surface plasmon polaritons (SPPs). The unique behaviors of MPs and SPPs are explained with the help of electromagnetic field distributions at respective resonance frequencies. An inductor-capacitor model is utilized to further confirm the excitation of MP, while dispersion relation is used to understand the behaviors of different SPP modes. Geometric effects of ridge width and grating period on the resonance absorption peaks are discussed. Moreover, directional responses at oblique incidences for different polarization states are studied. Fundamental understanding gained here will facilitate the design of novel metamateri...

  13. Concave Generalized Flows with Applications to Market Equilibria

    CERN Document Server

    Vegh, Laszlo A

    2011-01-01

    We consider a nonlinear extension of the generalized network flow model, with the flow leaving an arc being an increasing concave function of the flow entering it, as proposed by Truemper and Shigeno. We give the first polynomial time combinatorial algorithm for solving corresponding optimization problems, finding a epsilon-approximate solution in O(m(m+\\log n)\\log(MUm/epsilon)) arithmetic operations and value oracle queries, where M and U are upper bounds on simple parameters. For (linear) generalized flows, our algorithm can be seen as a variant of the highest-gain augmenting path algorithm by Goldfarb, Jin and Orlin. We show that this general convex programming model serves as a common framework for several market equilibrium problems, including the linear Fisher market model and its various extensions. Our result immediately enables us to extend these market models to more general settings and to solve some open problems in the literature.

  14. Double concave cesium encapsulation by two charged sumanenyl bowls

    Energy Technology Data Exchange (ETDEWEB)

    Spisak, Sarah N.; Wei, Zheng; Petrukhina, Marina A. [Department of Chemistry, University at Albany, State University of New York, Albany, NY (United States); Rogachev, Andrey Yu. [Department of Chemistry, Illinois Institute of Technology, Chicago, IL (United States); Amaya, Toru [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita (Japan); Hirao, Toshikazu [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita (Japan); The Institute of Scientific and Industrial Research, Osaka University (Japan)

    2017-03-01

    The controlled reaction of Na and Cs, two alkali metals of different ionic sizes and binding abilities, with sumanene (C{sub 21}H{sub 12}) affords a novel type of organometallic sandwich [Cs(C{sub 21}H{sub 11}{sup -}){sub 2}]{sup -}, which crystallized as a solvent-separated ion pair with a [Na(18-crown-6)(THF){sub 2}]{sup +} cation (where THF=tetrahydrofuran). The unprecedented double concave encapsulation of a metal ion by two bowl-shaped sumanenyl anions in [Cs(C{sub 21}H{sub 11}{sup -}){sub 2}]{sup -} was revealed crystallographically. Evaluation of bonding and energetics of the remarkable product was accomplished computationally (B2PLYP-D/TZVP/ZORA), providing insights into its formation. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. A Level Set Discontinuous Galerkin Method for Free Surface Flows

    DEFF Research Database (Denmark)

    Grooss, Jesper; Hesthaven, Jan

    2006-01-01

    We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by embedding and represented by a levelset. We discuss the discretization of the flow equations and the level set equation...... as well a various ways of advancing the equations in time using velocity projection techniques. The efficacy of the method for the representation of the levelset and its reinitialization is discussed and several numerical tests confirm the robustness and versatility of the proposed scheme....

  16. Efficient Clustering for Irregular Geometries Based on Identification of Concavities

    Directory of Open Access Journals (Sweden)

    Velázquez-Villegas Fernando

    2014-04-01

    Full Text Available Two dimensional clustering problem has much relevance in applications related to the efficient use of raw material, such as cutting stock, packing, etc. This is a very complex problem in which multiple bodies are accommodated efficiently in a way that they occupy as little space as possible. The complexity of the problem increases with the complexity of the bodies. Clearly the number of possible arrangements between bodies is huge. No Fit Polygon (NFP allows to determine the entire relative positions between two patterns (regular or irregular in contact, non-overlapping, therefore the best position can be selected. However, NFP generation requires a lot of calculations; besides, selecting the best cluster isn’t a simple task because, between two irregular patterns in contact, hollows (unusable areas and external concavities (usable areas can be produced. This work presents a quick and simple method to reduce calculations associated with NFP generation and to minimize unusable areas in a cluster. This method consists of generating partial NFP, just on concave regions of the patterns, and selecting the best cluster using a total weighted efficiency, i.e. a weighted value of enclosure efficiency (ratio of occupied area on convex hull area and hollow efficiency (ratio of occupied area on cluster area. The proposed method produces similar results as those obtained by other methods; however the shape of the clusters obtained allows to accommodate more parts in similar spaces, which is a desirable result when it comes to optimizing the use of material. We present two examples to show the performance of the proposal.

  17. Evaluation of hydrogen and oxygen impurity levels on silicon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, M.J.; Wielunski, L.S.; Netterfield, R.P.; Martin, P.J.; Leistner, A. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

    1996-12-31

    This paper reports on surface analytical techniques used to quantify surface concentrations of impurities such as oxygen and hydrogen. The following analytical techniques were used: Rutherford and Backscattering, elastic recoil detection, time-of-flight SIMS, spectroscopic ellipsometry, x-ray photoelectron spectroscopy. The results have shown a spread in thickness of oxide layer, ranging from unmeasurable to 1.6 nm. The data must be considered as preliminary at this stage, but give some insight into the suitability of the techniques and a general idea of the significance of impurities at the monolayer level. These measurements have been carried out on a small number of silicon surfaces both semiconductor grade <111> crystalline material and silicon which has been used in sphere fabrication. 5 refs., 1 fig.

  18. Surface core-level shifts for simple metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1994-01-01

    . We discuss the surface shifts of the electrostatic potentials and the band centers in order to trace the microscopic origin of the SCLS in the simple metals and find that the anomalous subsurface core-level shifts in beryllium are caused by charge dipoles, which persist several layers into the bulk......We have performed an ab initio study of the surface core-level binding energy shift (SCLS) for 11 of the simple metals by means of a Green’s-function technique within the tight-binding linear-muffin-tin-orbitals method. Initial- and final-state effects are included within the concept of complete....... We furthermore conclude that the unexpected negative sign of the SCLS in beryllium is predominantly an initial-state effect and is caused by the high electron density in this metal....

  19. The effect of polarity and surface states on the Fermi level at III-nitride surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, P; Bryan, I; Bryan, Z; Guo, W; Hussey, L; Collazo, R; Sitar, Z

    2014-09-28

    Surface states and their influence on the Fermi level at the surface of GaN and AlN are studied using x-ray photoelectron spectroscopy (XPS). The effect of polarity on surface electronic properties was studied. Accurate modeling of the valence band edge and comparison with XPS data revealed the presence of donor surface states at 1.4 eV and acceptor states at energies > 2.7 eV from the valence band in GaN. Al polar AlN showed acceptor states at energies > 3.3 eV. Density of acceptor surface states was estimated to be between 10(13) and 10(14) eV(-1) cm(-2) in both GaN and AlN. The shift in charge neutrality levels and barrier heights due to polarity and the density of surface states on AlN and GaN were estimated from XPS measurements. Theoretical modeling and comparison with XPS data implied full compensation of spontaneous polarization charge by charged surface states. Barrier height measurements also reveal a dependence on polarity with phi(metal-polar)>phi(non-polar)>phi(nitrogen-polar) suggesting that the N-polar surface is the most suitable for Ohmic contacts. (C) 2014 AIP Publishing LLC.

  20. Holographic fabrication of large-constant concave gratings for wide-range flat-field spectrometers with the addition of a concave lens.

    Science.gov (United States)

    Zhou, Qian; Li, Xinghui; Ni, Kai; Tian, Rui; Pang, Jinchao

    2016-01-25

    We present a new design for the fabrication of concave gratings with large grating constants for flat-field miniature spectrometers with a wide spectral band. In this new design, one of the two optical paths for the holographic lithography of a curved grating structure with variable line spacing is modified by adding a concave lens in front of the point source. The addition of the concave lens allows the real point source, as well as the spatial filter for generating this point source, to be moved back. In this manner, the two spatial filters for generating two point sources are separated. Avoiding the physical conflict between these two spatial filters reduces the difficulty of fabricating large-constant concave gratings. Experimental results verify the feasibility of the proposed design in fabricating concave gratings with large grating constants. The resolution of a spectrometer using the fabricated concave grating is evaluated and found to be better than 1.1 nm across a spectral band ranging from 360 nm to 825 nm.

  1. A Deterministic Inventory/Production Model with General Inventory Cost Rate Function and Concave Production Costs

    NARCIS (Netherlands)

    S.I. Birbil (Ilker); J.B.G. Frenk (Hans); Z.P. Bayindir (Pelin)

    2004-01-01

    textabstractWe present a thorough analysis of the economic order quantity model with shortages under a general inventory cost rate function and concave production costs. By using some standard results from convex analysis, we show that the model exhibits a composite concave-convex structure.

  2. Concave distal end of ulna metaphysis alone is not a sign of rickets

    Energy Technology Data Exchange (ETDEWEB)

    Oestreich, Alan E. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, 5031, Cincinnati, OH (United States)

    2015-07-15

    Statements have been made in the literature and in legal testimony that misrepresent the radiographic finding of concave distal end of the ulnar metaphysis. To demonstrate that a concave distal end of the ossified ulna in infancy can be normal. Eighty distal wrists of randomly selected infants in the first year of life with radiographic evidence that ruled out rickets were reviewed. In 16 of the cases (20%), mild or moderate concavity of the distal end of the ulna was seen. An intact metaphyseal collar of distal radius or ulna confirmed the absence of radiographic rickets. The finding of 20% of concave distal ulnas in the first year of life confirms the widely acknowledged statements that concave distal end of the ulna alone is not indicative of rickets. Statements to the contrary are not justified. (orig.)

  3. Elastomeric inverse moulding and vacuum casting process characterization for the fabrication of arrays of concave refractive microlenses

    Science.gov (United States)

    Desmet, L.; Van Overmeire, S.; Van Erps, J.; Ottevaere, H.; Debaes, C.; Thienpont, H.

    2007-01-01

    We present a complete and precise quantitative characterization of the different process steps used in an elastomeric inverse moulding and vacuum casting technique. We use the latter replication technique to fabricate concave replicas from an array of convex thermal reflow microlenses. During the inverse elastomeric moulding we obtain a secondary silicone mould of the original silicone mould in which the master component is embedded. Using vacuum casting, we are then able to cast out of the second mould several optical transparent poly-urethane arrays of concave refractive microlenses. We select ten particular representative microlenses on the original, the silicone moulds and replica sample and quantitatively characterize and statistically compare them during the various fabrication steps. For this purpose, we use several state-of-the-art and ultra-precise characterization tools such as a stereo microscope, a stylus surface profilometer, a non-contact optical profilometer, a Mach-Zehnder interferometer, a Twyman-Green interferometer and an atomic force microscope to compare various microlens parameters such as the lens height, the diameter, the paraxial focal length, the radius of curvature, the Strehl ratio, the peak-to-valley and the root-mean-square wave aberrations and the surface roughness. When appropriate, the microlens parameter under test is measured with several different measuring tools to check for consistency in the measurement data. Although none of the lens samples shows diffraction-limited performance, we prove that the obtained replicated arrays of concave microlenses exhibit sufficiently low surface roughness and sufficiently high lens quality for various imaging applications.

  4. Accuracy of Low-level Surface in Hierarchical Construction of Potential Energy Surface

    Institute of Scientific and Technical Information of China (English)

    Chun-rui Wang; Dong H. Zhang

    2012-01-01

    The effects of low-level PES on the overall accuracy of the final surface constructed by using hierarchical construction were investigated with the constructions of a number of global surfaces for the H3 system at UHF (UMP2,DFT-B3LYP,UCCSD(T))/vtz,and UCCSD(T)/avqz levels of theory.The total reaction probabilities for the H+H2 reaction calculated on these surfaces revealed that the accuracy of UCCSD(T)/avqz surface is very close to the well-known BKMP2 surface,while the UCCSD(T)/vtz PES has a slightly higher barrier.In contrast,the low-level theories (UHF,UMP2,DFT-B3LYP) with vtz basis set can only provide a qualitative description of this simplest reaction despite the fact that they are widely used to study reactions in complex systems.On the other hand,although these theories are not accurate on describing the reaction,they can be used to provide the lowlevel PESs for hierarchical construction of the UCCSD(T)/avqz PES with the number of UCCSD(T)/avqz energies substantially reduced.

  5. Ab initio surface core-level shifts and surface segregation energies

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1993-01-01

    We have calculated the surface core-level energy shifts of the 4d and 5d transition metals by means of local-density theory and a Green’s-function technique based on the linear muffin-tin orbitals method. Final-state effects are included by treating the core-ionized atom as an impurity located...

  6. Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

    CERN Document Server

    Díez Muniño, Ricardo

    2013-01-01

    This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

  7. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

  8. Study on the wavelength calibration of type III concave grating spectrometry system

    Institute of Scientific and Technical Information of China (English)

    Li Bai(白力); Ningfang Liao(廖宁放); Zhaojian Li(栗兆剑); Weiping Yang(杨卫平)

    2004-01-01

    We discuss and calibrate the spectrometry system based on concave reflection grating. The working principle, structure and parameters of the spectrometry system are introduced. For the wavelength calibration problem, three methods are put forward and discussed in detail with formulation calculation method, circular iteration method and interpolation. Interpolation is used to calibrate the concave reflection grating spectrometry system and the error is less than 1 nm. Four spectrum images that the system collected are given in this paper. The experimental results indicate that a spectrometry system can be based on concave reflection grating and be calibrated by interpolation.

  9. Error compensation on precision machine tool servo control system based on digital concave filter

    Institute of Scientific and Technical Information of China (English)

    王立松; 苏宝库; 张晶; 董申

    2001-01-01

    It is concluded from the results of testing the frequency characteristics of the sub-micron precision machine tool servo control system, that the existence of several oscillating modalities is the main factor that affects the performance of the control system. To compensate for this effect, several concave filters are utilized in the system to improve the control accuracy. The feasibility of compensating for several oscillating modalities with a single concave filter is also studied. By applying a modified Butterworth concave filter to the practical system, the maximum stable state output error remains under + 10 nm in the closed-loop positioning system.

  10. 3D MODELLING OF A SHRINK FITTED CONCAVE ENDED CYLINDRICAL TANK FOR AUTOMOTIVE INDUSTRY

    National Research Council Canada - National Science Library

    Mirela C Ghita; Constantin A Micu; Mihai D L Talu; Stefan D L Talu

    2013-01-01

      The aim of this work is to present a method that allows the optimal design of a shrink fitted concave ended cylindrical tank for the storage of methane gas, based on the application of the Finite Element Method (FEM...

  11. Profile measurement of concave spherical mirror and a flat mirror using a high-speed nanoprofiler.

    Science.gov (United States)

    Usuki, Koji; Kitayama, Takao; Matsumura, Hiroki; Kojima, Takuya; Uchikoshi, Junichi; Higashi, Yasuo; Endo, Katsuyoshi

    2013-05-16

    Ultraprecise aspheric mirrors that offer nanofocusing and high coherence are indispensable for developing third-generation synchrotron radiation and X-ray free-electron laser sources. In industry, the extreme ultraviolet (wavelength: 13.5 nm) lithography used for high-accuracy aspheric mirrors is a promising technology for fabricating semiconductor devices. In addition, ultraprecise mirrors with a radius of curvature of less than 10 mm are needed in many digital video instruments. We developed a new type of nanoprofiler that traces the normal vector of a mirror's surface. The principle of our measuring method is that the normal vector at each point on the surface is determined by making the incident light beam on the mirror surface and the reflected beam at that point coincide, using two sets of two pairs of goniometers and one linear stage. From the acquired normal vectors and their coordinates, the three-dimensional shape is calculated by a reconstruction algorithm. The characteristics of the measuring method are as follows: the profiler uses the straightness of laser light without using a reference surface. Surfaces of any shape can be measured, and there is no limit on the aperture size. We calibrated this nanoprofiler by considering the system error resulting from the assembly error and encoder scale error, and evaluated the performance at the nanometer scale. We suppressed the effect of random errors by maintaining the temperature in a constant-temperature room within ±0.01°C. We measured a concave spherical mirror with a radius of curvature of 400 mm and a flat mirror and compared the results with those obtained using a Fizeau interferometer. The profiles of the mirrors were consistent within the range of system errors.

  12. Nasal bone grafts from the removed hump used as overlay grafts to camouflage concave lateral crura.

    Science.gov (United States)

    Kubilay, Utku; Erdogdu, Suleyman; Sezen, Ozan Seymen

    2014-01-01

    Alar cartilage consists of a medial crus, middle crus and lateral crus. The lateral crus is an important aesthetic and functional structure of the nose. A 32-year-old male patient with concave lateral crura was operated by the authors. An open rhinoplasty with a dorsal approach to the septum is preferred. The nasal bones harvested from the hump, which is an autogenous graft trimmed and sutured on both concave lateral crura as an overlay camouflage grafts. Satisfactory result was achieved.

  13. Existence and uniqueness for a class of double pyramidal central configurations with a concave pentagonal base

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with a concave pentagonal base in 7-body problems are proved and the range of the ratio between radius and half-height is obtained, within which the 7 bodies involved form a central configuration or form uniquely a central configuration.

  14. Convex decomposition of concave clouds for the ultra-short-term power prediction of distributed photovoltaic system

    Institute of Scientific and Technical Information of China (English)

    蔡世波

    2016-01-01

    Concave clouds will cause miscalculation by the power prediction model based on cloud features for distributed photovoltaic (PV) plant.The algorithm for decomposing concave cloud into convex images is proposed .Adopting minimum polygonal approximation ( MPP) to demonstrate the contour of concave cloud , cloud features are described and the subdivision lines of convex decomposition for the concave clouds are determined by the centroid point scattering model and centroid angle func -tion, which realizes the convex decomposition of concave cloud .The result of MATLAB simulation indicates that the proposed algorithm can accurately detect cloud contour corners and recognize the concave points .The proposed decomposition algorithm has advantages of less time complexity and decomposition part numbers compared to traditional algorithms .So the established model can make the convex decomposition of complex concave clouds completely and quickly , which is available for the existing prediction algorithm for the ultra-short-term power output of distributed PV system based on the cloud features .

  15. Plasmonic enhancement of UV emission from ZnO thin films induced by Al nano-concave arrays

    Energy Technology Data Exchange (ETDEWEB)

    Norek, Małgorzata, E-mail: mnorek@wat.edu.pl [Department of Advanced Materials and Technologies, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); Łuka, Grzegorz [Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw (Poland); Włodarski, Maksymilian [Institute of Optoelectronics, Military University of Technology, Str. Kaliskiego 2, 00-908 Warszawa (Poland)

    2016-10-30

    Highlights: • Al nano-concave arrays with different interpore distance (D{sub c}) were prepared. • PL of ZnO thin films deposited directly on the Al nano-concaves were studied. • The effect of 10 nm Al{sub 2}O{sub 3} spacer on PL emission from ZnO thin films was analyzed. • Plasmonic enhancement of the PL emission was dependent on the D{sub c} and the spacer. • The highest 9-fold enhancement was obtained for the Al/ZnO sample with D{sub c} ∼333 nm. - Abstract: Surface plasmons (SPs) supported by Al nano-concave arrays with increasing interpore distance (D{sub c}) were used to enhance the ultraviolet light emission from ZnO thin films. Two sets of samples were prepared: in the first set the thin ZnO films were deposited directly on Al nanoconcaves (the Al/ZnO samples) and in the second set a 10 nm − Al{sub 2}O{sub 3} spacer was placed between the textured Al and the ZnO films (the Al/Al{sub 2}O{sub 3}-ALD/ZnO samples). In the Al/ZnO samples the enhancement was limited by a nonradiative energy dissipation due to the Ohmic loss in the Al metal. However, for the ZnO layer deposited directly on Al nanopits synthesized at 150 V (D{sub c} = 333 ± 18 nm), the largest 9-fold enhancement was obtained by achieving the best energy fit between the near band-edge (NBE) emission from ZnO and the λ{sub (0,1)} SPP resonance mode. In the Al/Al{sub 2}O{sub 3}-ALD/ZnO samples the amplification of the UV emission was smaller than in the Al/ZnO samples due to a big energy mismatch between the NBE emission and the λ{sub (0,1)} plasmonic mode. The results obtained in this work indicate that better tuning of the NBE − λ{sub (0,1)} SPP resonance mode coupling is possible through a proper modification of geometrical parameters in the Al/Al{sub 2}O{sub 3}-ALD/ZnO system such as Al nano-concave spacing and the thickness of the corresponding layer. This approach will reduce the negative influence of the non-radiative plasmonic modes and most likely will lead to further

  16. One-pot synthesis of high-index faceted AgCl nanocrystals with trapezohedral, concave hexoctahedral structures and their photocatalytic activity

    Science.gov (United States)

    Zhang, Haibin; Lu, Yonggang; Liu, Hong; Fang, Jingzhong

    2015-07-01

    AgCl semiconductor nanocrystals (NCs) with trapezohedral (TPH) and concave hexoctahedral (HOH) structures have been successfully synthesized for the first time in high yield by a direct one-pot solvothermal method. The as-prepared TPH, concave HOH AgCl NCs with unconventional polyhedral shapes and smooth surfaces were enclosed by 24 high-index {311} facets and 48 high-index {15 5 2} facets, respectively. A specific ionic liquid poly(diallyldimethylammonium) chloride (PDDA) acted as both a Cl- ion precursor and a morphology-controlled stabilizer, which was indispensable for the formation of these high-index faceted AgCl polyhedra and the derived uniform octahedral AgCl in an appropriate concentration of hot AgNO3 and ethylene glycol (EG) solution. With high-index facets exposed, both TPH and concave HOH AgCl NCs exhibit much higher photocatalytic activity than octahedral AgCl NCs that have mainly {111} faces exposed, with lower surface areas and surface energies, for the degradation of organics under sunlight. It is expected that the use of polyhedral AgCl NCs with high-index facets is an effective approach for the design of alternative semiconductor photocatalysts with a high performance, which may find potential applications such as in photochromics and environmental management.

  17. Synthesis of Pd-Pt bimetallic nanocrystals with a concave structure through a bromide-induced galvanic replacement reaction.

    Science.gov (United States)

    Zhang, Hui; Jin, Mingshang; Wang, Jinguo; Li, Weiyang; Camargo, Pedro H C; Kim, Moon J; Yang, Deren; Xie, Zhaoxiong; Xia, Younan

    2011-04-20

    This article describes a systematic study of the galvanic replacement reaction between PtCl(6)(2-) ions and Pd nanocrystals with different shapes, including cubes, cuboctahedrons, and octahedrons. It was found that Br(-) ions played an important role in initiating, facilitating, and directing the replacement reaction. The presence of Br(-) ions led to the selective initiation of galvanic replacement from the {100} facets of Pd nanocrystals, likely due to the preferential adsorption of Br(-) ions on this crystallographic plane. The site-selective galvanic replacement resulted in the formation of Pd-Pt bimetallic nanocrystals with a concave structure owing to simultaneous dissolution of Pd atoms from the {100} facets and deposition of the resultant Pt atoms on the {111} facets. The Pd-Pt concave nanocubes with different weight percentages of Pt at 3.4, 10.4, 19.9, and 34.4 were also evaluated as electrocatalysts for the oxygen reduction reaction (ORR). Significantly, the sample with a 3.4 wt.% of Pt exhibited the largest specific electrochemical surface area and was found to be four times as active as the commercial Pt/C catalyst for the ORR in terms of equivalent Pt mass.

  18. Concave pulse shaping of a circularly polarized laser pulse from non-uniform overdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Min Sup [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan, 689-798 (Korea, Republic of); Kulagin, Victor V. [Sternberg Astronomical Institute, Moscow State University, Universitetsky prosp. 13, Moscow, 119992 (Russian Federation); Suk, Hyyong, E-mail: hysuk@gist.ac.kr [Department of Physics and Photon Science, GIST, 123 Cheomdan-gwangiro, Buk-gu, Gwangju, 500-712 (Korea, Republic of)

    2015-03-20

    Pulse shaping of circularly polarized laser pulses in nonuniform overdense plasmas are investigated numerically. Specifically we show by two-dimensional particle-in-cell simulations the generation of a concave pulse front of a circularly polarized, a few tens of petawatt laser pulse from a density-tapered, overdense plasma slab. The concept used for the transverse-directional shaping is the differential transmittance depending on the plasma density, and the laser intensity. For suitable selection of the slab parameters for the concave pulse shaping, we studied numerically the pulse transmittance, which can be used for further parameter design of the pulse shaping. The concavely shaped circularly polarized pulse is expected to add more freedom in controlling the ion-beam characteristics in the RPDA regime. - Highlights: • Laser pulse shaping for a concave front by non-uniform overdense plasma was studied. • Particle-in-cell (PIC) simulations were used for the investigation. • A laser pulse can be shaped by a density-tapered overdense plasma. • The concave and sharp pulse front are useful in many laser–plasma applications. • They are important for ion acceleration, especially in the radiation pressure dominant regime.

  19. Structural Health Monitoring of Tall Buildings with Numerical Integrator and Convex-Concave Hull Classification

    Directory of Open Access Journals (Sweden)

    Suresh Thenozhi

    2012-01-01

    Full Text Available An important objective of health monitoring systems for tall buildings is to diagnose the state of the building and to evaluate its possible damage. In this paper, we use our prototype to evaluate our data-mining approach for the fault monitoring. The offset cancellation and high-pass filtering techniques are combined effectively to solve common problems in numerical integration of acceleration signals in real-time applications. The integration accuracy is improved compared with other numerical integrators. Then we introduce a novel method for support vector machine (SVM classification, called convex-concave hull. We use the Jarvis march method to decide the concave (nonconvex hull for the inseparable points. Finally the vertices of the convex-concave hull are applied for SVM training.

  20. Performance Comparison between Nonidentical Segmented Exponential Concave and Nonidentical Segmented Exponential Convex Serrated CATRs

    Directory of Open Access Journals (Sweden)

    T. Venkata Rama Krishna

    2008-01-01

    Full Text Available This paper presented a theoretical and numerical assessment for nonidentical segmented exponential- (NISE- convex and NISE-concave serrated plane CATRs by changing number of serrations. The investigation was based on diffraction theory and, more specifically, on the diffraction formulation of Fresnel. The compact antenna test range (CATR provides uniform illumination within the Fresnel region to the test antenna. Application of serrated edges has been shown to be a good method to control diffraction at the edges of the reflectors. In this paper, the Fresnel fields of NISE-convex and NISE-concave serrated CATRs are analyzed using physical optics (PO technique. The PO analysis is applied in this paper for plane reflector serrated CATR only. The same analysis is applied to any type of reflector. In this paper, lens-based reflector is not considered. It is observed that NISE-concave serrated CATR gives less ripple and enhanced quiet zone width than NISE-convex.

  1. Design and analysis of spectral beam combining system for fiber lasers based on a concave grating

    Institute of Scientific and Technical Information of China (English)

    WU Zhuo-liang; ZHAO Shang-hong; CHU Xing-chun; ZHANG Xi; ZHAN Sheng-bao; MA Li-hua

    2012-01-01

    Anovel fiber laser spectral beam combining scheme based on a concave grating is presented.The principle of the presented system is analyzed,and a concave grating with blazed structure for spectral beam combining is designed.The combining potential of the system is analyzed,and the results show that 39 Yb-doped fiber laser can be spectrally beam combined via the designed system.By using scalar diffraction theory,the combining effect of the system is analyzed.The results show that the diffraction efficiency of the designed concave grating is higher than 72% over the whole gain bandwidth,and the combining efficiency is 73.4%.With output power of 1 kW for individual fiber laser,combined power of 28.6 kW can be achieved.

  2. Solution structure of histone chaperone ANP32B: interaction with core histones H3-H4 through its acidic concave domain.

    Science.gov (United States)

    Tochio, Naoya; Umehara, Takashi; Munemasa, Yoshiko; Suzuki, Toru; Sato, Shin; Tsuda, Kengo; Koshiba, Seizo; Kigawa, Takanori; Nagai, Ryozo; Yokoyama, Shigeyuki

    2010-08-01

    Eukaryotic gene expression is regulated by histone deposition onto and eviction from nucleosomes, which are mediated by several chromatin-modulating factors. Among them, histone chaperones are key factors that facilitate nucleosome assembly. Acidic nuclear phosphoprotein 32B (ANP32B) belongs to the ANP32 family, which shares N-terminal leucine-rich repeats (LRRs) and a C-terminal variable anionic region. The C-terminal region functions as an inhibitor of histone acetylation, but the functional roles of the LRR domain in chromatin regulation have remained elusive. Here, we report that the LRR domain of ANP32B possesses histone chaperone activity and forms a curved structure with a parallel beta-sheet on the concave side and mostly helical elements on the convex side. Our analyses revealed that the interaction of ANP32B with the core histones H3-H4 occurs on its concave side, and both the acidic and hydrophobic residues that compose the concave surface are critical for histone binding. These results provide a structural framework for understanding the functional mechanisms of acidic histone chaperones.

  3. A Molecular-Level Account of the Antigenic Hantaviral Surface

    Directory of Open Access Journals (Sweden)

    Sai Li

    2016-05-01

    Full Text Available Hantaviruses, a geographically diverse group of zoonotic pathogens, initiate cell infection through the concerted action of Gn and Gc viral surface glycoproteins. Here, we describe the high-resolution crystal structure of the antigenic ectodomain of Gn from Puumala hantavirus (PUUV, a causative agent of hemorrhagic fever with renal syndrome. Fitting of PUUV Gn into an electron cryomicroscopy reconstruction of intact Gn-Gc spike complexes from the closely related but non-pathogenic Tula hantavirus localized Gn tetramers to the membrane-distal surface of the virion. The accuracy of the fitting was corroborated by epitope mapping and genetic analysis of available PUUV sequences. Interestingly, Gn exhibits greater non-synonymous sequence diversity than the less accessible Gc, supporting a role of the host humoral immune response in exerting selective pressure on the virus surface. The fold of PUUV Gn is likely to be widely conserved across hantaviruses.

  4. Metacoatings for wavelength scale, high NA plano-concave focusing lenses

    CERN Document Server

    Naserpour, Mahin; Díaz-Aviñó, Carlos; Hashemi, Mahdieh

    2016-01-01

    We design plano-concave silicon lenses with coupled gradient-index plasmonic metacoatings for ultrawide apertured focusing utilizing a reduced region of $\\sim 20 \\lambda^2$. The anomalous refraction induced in the planar input side of the lens and in the boundary of the wavelength-scale focal region boosts the curvature of the emerging wavefront, thus significantly enhancing the resolution of the tightly-focused optical wave. The formation of a light tongue with dimensions approaching those of the concave opening is here evidenced. This scheme is expected to have potential applications in optical trapping and detection.

  5. The Successor Function and Pareto Optimal Solutions of Cooperative Differential Systems with Concavity. I

    DEFF Research Database (Denmark)

    Andersen, Kurt Munk; Sandqvist, Allan

    1997-01-01

    We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution.......We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution....

  6. The effect of capillary pressure for concave liquid-vapor interface on interfacial evaporation

    Institute of Scientific and Technical Information of China (English)

    张金涛; 王补宣; 彭晓峰

    2001-01-01

    The analysis in this paper demonstrates that the capillary pressure on the concave liquid-vapor interface will promote the interfacial evaporation, therefore clarifying the confusion over the great difference between the estimated and real rate of interfacial evaporation. This difference increases with decreasing capillary radius, and becomes more apparent for liquid with high latent heat. The present analysis also shows that the capillary pressure on the concave interface will result in a decrease in liquid phase equilibrium temperature, which can explain the possibility of vapor bubble formation on micro liquid layer interfacial evaporation under low superheat, or even below the nominal saturated temperature.

  7. Supercontinuum Spectra generation in the single-mode optical fibre with Concave dispersion profile

    Institute of Scientific and Technical Information of China (English)

    Xu Wen-Cheng; Gao Jie-Li; Liang Zhan-Qiang; Chen Qiao-Hong; Liu Song-Hao

    2006-01-01

    In this paper,a new method is proposed to generate broad supercontinuum (SC) spectra in the single-mode optical fibre with concave dispersion profile.We numerically simulate pulse evolutions and discuss physics mechanism in detail for SC spectrum generation in the optical fibre with concave dispersion profile.Furthermore,general criteria are presented for specifying the shape of SC spectrum by introducing normalized parameters,which are related to the fibres and the initial pump pulses.The results show that the flat and broad SC spectra are indeed generated in our proposed optical fibre.

  8. Ocular surface adverse effects of ambient levels of air pollution

    Directory of Open Access Journals (Sweden)

    André Augusto Miranda Torricelli

    2011-10-01

    Full Text Available It is widely recognized today that outdoor air pollution can affect human health. Various chemical components that are present in ambient pollution may have an irritant effect on the mucous membranes of the body, particularly those of the respiratory tract. Much less attention has been focused on the adverse effect on the ocular surface, despite the fact that this structure is even more exposed to air pollution than the respiratory mucosa since only a very thin tear film separates the corneal and conjunctival epithelia from the air pollutants. So far, clinical data are the more widespread tools used by ophthalmologists for assessing possible aggression to the ocular surface; however, clinical findings alone appears not to correlate properly with the complaints presented by the patients pointing out the need for further clinical and laboratory studies on the subject. The purpose of this study is to review signs and symptoms associated with chronic long-term exposure to environmental air pollutants on the ocular structures currently defined as the ocular surface and to review clinical and laboratory tests used to investigate the adverse effects of air pollutants on such structures. We also review previous studies that investigated the adverse effects of air pollution on the ocular surface and discuss the need for further investigation on the subject.

  9. Characterization of some psorosis and concave gum isolates from northwestern Argentina Caracterización de aislamientos de psorosis y concave gum del noroeste argentino

    Directory of Open Access Journals (Sweden)

    Julia Figueroa

    Full Text Available The Citrus Sanitation Center of the Estación Experimental Agroindustrial Obispo Colombres in Tucumán, Argentina, has developed a virus bank of various graft-transmissible citrus pathogens found in northwestern Argentina. In this bank, several psorosis and concave gum isolates are maintained in Pineapple sweet orange seedlings. In order to characterize these pathogens, 11 isolates were indexed to seedlings of Pineapple sweet orange, Dweet tangor, Eureka lemon plus Etrog citron budded on rough lemon seedlings. Cross protection was applied for identifying psorosis-A. Symptoms obtained were variable and ranged from mild to very severe. A clear effect of temperature on symptom expression, and distinct differences in the reactions between psorosis-A and concave gum viruses were detected.El Centro de Saneamiento de Citrus de la Estación Experimental Agroindustrial Obispo Colombres, de Tucumán, Argentina, ha constituido un banco de virus de cítricos con material recolectado en la región noroeste del país. El mismo cuenta con varios aislamientos de psorosis y concave gum que se mantienen en plantas de naranjo dulce Pineapple. Con el objetivo de caracterizar biológicamente 11 de estos aislamientos, se inocularon plantines de naranjo dulce Pineapple, Dweet tangor, limonero Eureka y plantas injertadas de cidro Etrog en limoneros rugoso. Las pruebas con Pineapple se realizaron por duplicado bajo dos condiciones de temperatura: frías y calientes. La confirmación de psorosis A se realizó mediante prueba de protección cruzada con un aislamiento de psorosis B. Los resultados obtenidos muestran una amplia diversidad biológica entre los aislamientos, con expresión de síntomas que variaron desde suaves a muy severos. Se confirmó la presencia de psorosis A y se encontró que los aislamientos de "concave gum" del banco de virus no estaban en mezcla con psorosis. El efecto de la temperatura en la manifestación de los síntomas fue significativo y se

  10. Atomic-level imaging, processing and characterization of semiconductor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kazmerski, L.L.

    1995-08-22

    A method for selecting and removing single specific atoms from a solid material surface uses photon biasing to break down bonds that hold the selected atom in the lattice and to reduce barrier effects that hold the atom from transferring to a probe. The photon bias is preferably light or other electromagnetic radiation with a wavelength and frequency that approximately matches the wave function of the target atom species to be removed to induce high energy, selective thermionic-like vibration. An electric field potential is then applied between the probe and the surface of the solid material to pull the atom out of the lattice and to transfer the atom to the probe. Different extrinsic atoms can be installed in the lattice sites that are vacated by the removed atoms by using a photon bias that resonates the extrinsic atom species, reversing polarity of the electric field, and blowing gas comprising the extrinsic atoms through a hollow catheter probe. 8 figs.

  11. Atomic-level imaging, processing and characterization of semiconductor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kazmerski, Lawrence L. (Lakewood, CO)

    1995-01-01

    A method for selecting and removing single specific atoms from a solid material surface uses photon biasing to break down bonds that hold the selected atom in the lattice and to reduce barrier effects that hold the atom from transferring to a probe. The photon bias is preferably light or other electromagnetic radiation with a wavelength and frequency that approximately matches the wave function of the target atom species to be removed to induce high energy, selective thermionic-like vibration. An electric field potential is then applied between the probe and the surface of the solid material to pull the atom out of the lattice and to transfer the atom to the probe. Different extrinsic atoms can be installed in the lattice sites that are vacated by the removed atoms by using a photon bias that resonates the extrinsic atom species, reversing polarity of the electric field, and blowing gas comprising the extrinsic atoms through a hollow catheter probe.

  12. STS Observations of Landau Levels at Graphite Surfaces

    OpenAIRE

    Matsui, T.; Kambara, H.; Niimi, Y.; Tagami, K.; Tsukada, M; Fukuyama, Hiroshi

    2004-01-01

    Scanning tunneling spectroscopy measurements were made on surfaces of two different kinds of graphite samples, Kish graphite and highly oriented pyrolytic graphite (HOPG), at very low temperatures and in high magnetic fields. We observed a series of peaks in the tunnel spectra, which grow with increasing field, both at positive and negative bias voltages. These are associated with Landau quantization of the quasi two-dimensional electrons and holes in graphite in magnetic fields perpendicular...

  13. GHRSST Level 4 ODYSSEA Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  14. GHRSST Level 4 GAMSSA Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Australian Bureau...

  15. GHRSST Level 4 RAMSSA Australian Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Australian Bureau...

  16. GHRSST Level 4 EUR Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily by Ifremer/CERSAT (France) using optimal...

  17. GHRSST Level 4 ODYSSEA Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  18. GHRSST Level 4 ODYSSEA Eastern Central Pacific Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  19. GHRSST Level 4 G1SST Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the JPL OurOcean...

  20. GHRSST Level 4 DMI_OI Global Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  1. GHRSST Level 4 OSTIA Global Foundation Sea Surface Temperature Analysis (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the UK Met Office...

  2. GHRSST Level 4 MW_OI Global Foundation Sea Surface Temperature analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.25 degree grid at Remote Sensing...

  3. GHRSST Level 4 MUR North America Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced as a retrospective dataset at the JPL Physical...

  4. GHRSST Level 4 OSPO Global Nighttime Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Office of...

  5. GHRSST Level 4 OSPO Global Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Office of...

  6. GHRSST Level 4 AVHRR_AMSR_OI Global Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.25 degree grid at the NOAA...

  7. GHRSST Level 4 K10_SST Global 1 meter Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Naval...

  8. Attachment of Surface "Fermi Arcs" to the Bulk Fermi Surface: "Fermi-Level Plumbing" in Topological Metals

    OpenAIRE

    Haldane, F. D. M.

    2014-01-01

    The role of "Fermi arc" surface-quasiparticle states in "topological metals" (where some Fermi surface sheets have non-zero Chern number) is examined. They act as "Fermi-level plumbing" conduits that transfer quasiparticles among groups of apparently-disconnected Fermi sheets with non-zero Chern numbers to maintain equality of their chemical potentials, which is required by gauge invariance. Fermi arcs have a chiral tangential attachment to the surface projections of sheets of the bulk Fermi ...

  9. Etude aerodynamique d'un jet turbulent impactant une paroi concave

    Science.gov (United States)

    LeBlanc, Benoit

    Etant donne la demande croissante de temperatures elevees dans des chambres de combustion de systemes de propulsions en aerospatiale (turbomoteurs, moteur a reaction, etc.), l'interet dans le refroidissement par jets impactant s'est vu croitre. Le refroidissement des aubes de turbine permet une augmentation de temperature de combustion, ce qui se traduit en une augmentation de l'efficacite de combustion et donc une meilleure economie de carburant. Le transfert de chaleur dans les au bages est influence par les aspects aerodynamiques du refroidissement a jet, particulierement dans le cas d'ecoulements turbulents. Un manque de comprehension de l'aerodynamique a l'interieur de ces espaces confinees peut mener a des changements de transfert thermique qui sont inattendus, ce qui augmente le risque de fluage. Il est donc d'interet pour l'industrie aerospatiale et l'academie de poursuivre la recherche dans l'aerodynamique des jets turbulents impactant les parois courbes. Les jets impactant les surfaces courbes ont deja fait l'objet de nombreuses etudes. Par contre des conditions oscillatoires observees en laboratoire se sont averees difficiles a reproduire en numerique, puisque les structures d'ecoulements impactants des parois concaves sont fortement dependantes de la turbulence et des effets instationnaires. Une etude experimentale fut realisee a l'institut PPRIME a l'Universite de Poitiers afin d'observer le phenomene d'oscillation dans le jet. Une serie d'essais ont verifie les conditions d'ecoulement laminaires et turbulentes, toutefois le cout des essais experimentaux a seulement permis d'avoir un apercu du phenomene global. Une deuxieme serie d'essais fut realisee numeriquement a l'Universite de Moncton avec l'outil OpenFOAM pour des conditions d'ecoulement laminaire et bidimensionnel. Cette etude a donc comme but de poursuivre l'enquete de l'aerodynamique oscillatoire des jets impactant des parois courbes, mais pour un regime d'ecoulement transitoire, turbulent

  10. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    Directory of Open Access Journals (Sweden)

    Arkadiusz Jarosław GOSZCZAK

    2017-02-01

    Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

  11. Vertices of the least concave majorant of Brownian motion with parabolic drift

    CERN Document Server

    Groeneboom, Piet

    2010-01-01

    It was shown in Groeneboom (1983) that the least concave majorant of one-sided Brownian motion without drift can be characterized by a jump process with independent increments, which is the inverse of the process of slopes of the least concave majorant. This result can be used to prove the result of Sparre Andersen (1954) that the number of vertices of the smallest concave majorant of the empirical distribution function of a sample of size n from the uniform distribution on [0,1] is asymptotically normal, with an asymptotic expectation and variance which are both of order log n. A similar (Markovian) inverse jump process was introduced in Groeneboom (1989), in an analysis of the least concave majorant of two-sided Brownian motion with a parabolic drift. This process is quite different from the process for one-sided Brownian motion without drift: the number of vertices in a (corresponding slopes) interval has an expectation proportional to the length of the interval and the variance of the number of vertices i...

  12. On some fractional equations with convex-concave and logistic-type nonlinearities

    Science.gov (United States)

    Carboni, Giulia; Mugnai, Dimitri

    2017-02-01

    We consider existence and multiplicity results for a semilinear problem driven by the square root of the negative Laplacian in presence of a nonlinear term which is the difference of two powers. In the case of convex-concave powers, a precise description of the problem at the threshold value of a given parameter is established through variational methods and truncation techniques.

  13. Bicuspid aortic valve hemodynamics does not promote remodeling in porcine aortic wall concavity

    Institute of Scientific and Technical Information of China (English)

    Samantha K Atkins; Alison N Moore; Philippe Sucosky

    2016-01-01

    AIM: To investigate the role of type-I left-right bicuspid aortic valve(LR-BAV) hemodynamic stresses in the remodeling of the thoracic ascending aorta(AA) concavity, in the absence of underlying genetic or structural defects.METHODS: Transient wall shear stress(WSS) profiles in the concavity of tricuspid aortic valve(TAV) and LR-BAV AAs were obtained computationally. Tissue specimens excised from the concavity of normal(nondilated) porcine AAs were subjected for 48 h to those stress environments using a shear stress bioreactor. Tissue remodeling was characterized in terms of matrix metalloproteinase(MMP) expression and activity via immunostaining and gelatin zymography.RESULTS: Immunostaining semi-quantification results indicated no significant difference in MMP-2 and MMP-9 expression between the tissue groups exposed to TAV and LR-BAV AA WSS(P = 0.80 and P = 0.19, respectively). Zymography densitometry revealed no difference in MMP-2 activity(total activity, active form and latent form) between the groups subjected to TAV AA and LR-BAV AA WSS(P = 0.08, P = 0.15 and P = 0.59, respectively).CONCLUSION: The hemodynamic stress environment present in the concavity of type-I LR-BAV AA does not cause any significant change in proteolytic enzyme expression and activity as compared to that present in the TAV AA.

  14. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    Directory of Open Access Journals (Sweden)

    Arkadiusz Jarosław GOSZCZAK

    2017-02-01

    Full Text Available In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al films evaporated via e-beam evaporation on Si substrates. The template formation leads to natural patterning of the underlying Al layers that are used as rigid masters for stamp fabrication, after selective etching of the porous anodic alumina. PDMS stamps were made after replicating the Al concave patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption that is attributed to field enhancement and diffuse scattering, leading to efficient light trapping for a selected active layer material (P3HT:PCBM.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14188

  15. Stable anisotropic plasma confinement in magnetic configurations with convex-concave field lines

    Science.gov (United States)

    Tsventoukh, M. M.

    2014-02-01

    It is shown that a combination of the convex and the concave part of a field line provides a strong stabilizing action against convective (flute-interchange) plasma instability (Tsventoukh 2011 Nucl. Fusion 51 112002). This results in internal peaking of the stable plasma pressure profile that is calculated from the collisionless kinetic stability criterion for any magnetic confinement system with combination of mirrors and cusps. Connection of the convex and concave field line parts results in a reduction of the space charge that drives the unstable E × B motion, as there is an opposite direction of the particle drift in a non-uniform field at convex and concave field lines. The pressure peaking arises at the minimum of the second adiabatic invariant J that takes place at the ‘middle’ of a tandem mirror-cusp transverse cross-section. The position of the minimum in J varies with the particle pitch angle that results in a shift of the peaking position depending on plasma anisotropy. This allows one to improve a stable peaked pressure profile at a convex-concave field by changing the plasma anisotropy over the trap cross-section. Examples of such anisotropic distribution functions are found that give an additional substantial enhancement in the maximal central pressure. Furthermore, the shape of new calculated stable profiles has a wide central plasma layer instead of a narrow peak.

  16. The Scallop's Eye--A Concave Mirror in the Context of Biology

    Science.gov (United States)

    Colicchia, Giuseppe; Waltner, Christine; Hopf, Martin; Wiesner, Hartmut

    2009-01-01

    Teaching physics in the context of medicine or biology is a way to generate students' interest in physics. A more uncommon type of eye, the scallop's eye (an eye with a spherical concave mirror, which is similar to a Newtonian or Schmidt telescope) and the image-forming mechanism in this eye are described. Also, a simple eye model, which can…

  17. An analytic solution for calculating the beam intensity profiles useful to irradiate target volumes with bi-concave outlines

    Energy Technology Data Exchange (ETDEWEB)

    De Neve, W.; Derycke, S.; De Wagter, C. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

    1995-12-01

    A heuristic planing procedure allowing to obtain a 3-dimensional conformal dose distribution in radiotherapy for target volumes with a bi-concave or multi-concave shape has been developed. The described method is tested on a phantom simulating a pelvic target, described by Brahme.

  18. Elevated Channel Concavities Arising from Sediment-Flux Effects in Natural Rivers

    Science.gov (United States)

    Hobley, D. E. J.; Sinclair, H. D.; Gasparini, N. M.; Tucker, G. E.; Cowie, P. A.; Adams, J. M.; Hutton, E. W. H.; Istanbulluoglu, E.; Nudurupati, S. S.

    2014-12-01

    The concavity of an incising river system - a measure of the rate of change of its bed slope with increasing discharge downstream - is a commonly used metric in fluvial geomorphology. It is commonly used in assessing variation of factors such as uplift, climate, and rock type along a system in a qualitative way, and underpins a number of quantitative analyses in tectonic geomorphology, such as the normalized channel steepness index. However, the factors that fundamentally control channel concavities in rocky streams remain relatively poorly understood, especially in rivers that are undergoing transient response to a perturbation in their boundary conditions.Here we use a combination of field data and numerical modeling to demonstrate that elevated channel concavities are a common and shared response to the propagation of a convex-upward "knickzone" through a bedrock channel long profile. Simulations using the novel modeling framework Landlab exploring thresholded incision and saltation-abrasion theory indicate that the presence of the knickzone can perturb the relative sediment flux in the area immediately downstream of the convexity, allowing enhanced erosion there and systematic elevation of channel concavities in reaches downstream of this point. The reality of this effect is demonstrated using field and remotely sensed data from three sites - the Red River area, Yunnan, China; channels on the Ladakh batholith, Indian Himalaya; and the Fagaras Alps, Romania. All contain broad scale migrating knickzones, but the causes of the disturbances that produced them and scales of the systems differ. Nonetheless, the concavities of all the channels are all elevated in the same way downstream of knickzones, consistent with the modeling output. These results demonstrate the ubiquity of sediment flux effects on erosion rates in many natural channels, and have consequences for the way we read tectonic histories from landscapes.

  19. Concave-hemisphere-patterned organic top-light emitting device

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen R.; Slootsky, Michael; Lunt, Richard

    2015-06-09

    A first device is provided. The first device includes an organic light emitting device, which further comprises a first electrode, a second electrode, and an organic emissive layer disposed between the first and second electrode. Preferably, the second electrode is more transparent than the first electrode. The organic emissive layer has a first portion shaped to form an indentation in the direction of the first electrode, and a second portion shaped to form a protrusion in the direction of the second electrode. The first device may include a plurality of organic light emitting devices. The indentation may have a shape that is formed from a partial sphere, a partial cylinder, a pyramid, or a pyramid with a mesa, among others. The protrusions may be formed between adjoining indentations or between an indentation and a surface parallel to the substrate.

  20. Self-aligning concave relativistic plasma mirror with adjustable focus

    CERN Document Server

    Tsai, Hai-En; Shaw, Joseph M; Stark, David J; Wang, Xiaoming; Zgadzaj, Rafal; Downer, M C

    2016-01-01

    We report an experimental-computational study of the optical properties of plasma mirrors (PMs) at the incident laser frequency when irradiated directly at relativistic intensity (1e18 < I_0 < 1e19 W/cm^2) by near-normally incident (4 degree), high-contrast, 30 fs, 800 nm laser pulses. We find that such relativistic PMs are highly reflective (0.6 to 0.8), and focus a significant fraction of reflected light to intensity as large as 10I_0 at distance f as small 25 microns from the PM, provided that pre-pulses do not exceed 1e14 W/cm^2 prior to 20 ps before arrival of the main pulse peak. Particle-in-cell simulations show that focusing results from denting of the reflecting surface by light pressure combined with relativistic transparency, and that reflectivity and f can be adjusted by controlling pre-plasma length L over the range 0.5 < L < 3 microns. Pump-probe reflectivity measurements show the PM's focusing properties evolve on a ps time scale.

  1. 78 FR 21980 - Aging Management of Internal Surfaces, Service Level III and Other Coatings, Atmospheric Storage...

    Science.gov (United States)

    2013-04-12

    ... COMMISSION Aging Management of Internal Surfaces, Service Level III and Other Coatings, Atmospheric Storage...-2012-02, ``Aging Management of Internal Surfaces, Service Level III and Other Coatings, Atmospheric... aging management programs (AMP) and aging management review (AMR) items in NUREG-1801, Revision 2...

  2. Understanding the formation of CuS concave superstructures with peroxidase-like activity

    Science.gov (United States)

    He, Weiwei; Jia, Huimin; Li, Xiaoxiao; Lei, Yan; Li, Jing; Zhao, Hongxiao; Mi, Liwei; Zhang, Lizhi; Zheng, Zhi

    2012-05-01

    Copper sulfide (CuS) concave polyhedral superstructures (CPSs) have been successfully prepared in an ethanolic solution by a simple solvothermal reaction without the use of surfactants or templates. Two typical well defined, high symmetry CuS concave polyhedrons, forming a concave truncated cuboctahedron and icosahedron were prepared. The effect of the reaction time, temperature and different Cu ion and sulfur sources on the formation of CuS CPSs were investigated and a possible formation mechanism was proposed and discussed based on gas chromatography-mass spectrometry. More importantly, we found, for the first time, that the CuS CPSs exhibit intrinsic peroxidase-like activity, as they can quickly catalyze the oxidation of typical horseradish peroxidase (HRP) substrates, 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD), in the presence of hydrogen peroxide. In addition to the recent discoveries regarding peroxidase mimetics on Fe3O4 NPs and carbon nanostructures, our findings suggest a new kind of candidate for peroxidase mimics. This may open up a new application field of CuS micro-nano structures in biodetection, biocatalysis and environmental monitoring.Copper sulfide (CuS) concave polyhedral superstructures (CPSs) have been successfully prepared in an ethanolic solution by a simple solvothermal reaction without the use of surfactants or templates. Two typical well defined, high symmetry CuS concave polyhedrons, forming a concave truncated cuboctahedron and icosahedron were prepared. The effect of the reaction time, temperature and different Cu ion and sulfur sources on the formation of CuS CPSs were investigated and a possible formation mechanism was proposed and discussed based on gas chromatography-mass spectrometry. More importantly, we found, for the first time, that the CuS CPSs exhibit intrinsic peroxidase-like activity, as they can quickly catalyze the oxidation of typical horseradish peroxidase (HRP) substrates, 3

  3. Effects of surface drag on upper-level frontogenesis within a developing baroclinic wave

    Science.gov (United States)

    Zhang, Yi; Tan, Zhemin; Chu, Kekuan

    2016-08-01

    This paper investigates the effects of surface drag on upper-level front with a three-dimensional nonhydrostatic mesoscale numerical model (MM5). To this end, a new and simple potential vorticity intrusion (PVI) index is proposed to quantitatively describe the extent and path that surface drag affects upper-level front. From a PV perspective, the formation of the upper-level front is illustrated as the tropopause folding happens from the stratosphere. The PVI index shows a good correlation with the minimum surface pressure, and tends to increase with the deepening of the surface cyclone and upper-level front. The surface drag acts to damp and delay the development of upper-level front, which could reduce the growth rate of the PVI index. However, the damping presents different effects in different development stages. It is the most significant during the rapid development stage of the surface cyclone. Compared with no surface drag cases, the tropopause is less inclined to intrude into the troposphere due to the surface drag. Positive feedback between the surface cyclone and upper-level front could accelerate the development of the frontal system.

  4. Effects of surface drag on low-level frontogenesis within baroclinic waves

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; TAN ZheMin

    2007-01-01

    Using a three-dimensional nonhydrostatic mesoscale numerical model (MM5), the evolution and structures of baroclinic waves with and without surface drag in case of dry and moist atmosphere are simulated, with special emphases on the effects of surface drag on the low-level frontal structure and frontogenesis. There are two different effects of surface drag on the low-level frontogenesis in the dry case. On one hand, the surface drag weakens the low-level frontogenesis and less inclined to develop the baroclinic wave due to the dissipation. But on the other hand, the surface drag induces a strong ageostrophic flow, which prolongs the low-level frontogenesis and finally leads to the enhancement of cold front. Compared with the no surface drag case, the surface drag increases the frontal slope especially in the boundary layer, where the front is almost vertical to the surface, and then enhances the prefrontal vertical motion. All these conclusions expanded the analytical theory of Tan and Wu (1990). In the moist atmosphere, the influence of surface drag on frontal rainbands is also obvious. The surface drag weakens the convection, and reduces the energy dissipation near the surface when the initial relative humidity is relatively weak. At this time, the confluence induced post-frontal updrafts moves across the cold front and reinforces the prefrontal convection, which is beneficial to the maintenance of the rainband in cold sector. Given the enhancement of relative humidity, the moist convection dominates the low-level frontogenesis while the retardation of surface drag on energy dissipation is not obvious, therefore the effects of surface drag on the low-level frontogenesis and precipitation are reduced.

  5. Effects of surface drag on low-level frontogenesis within baroclinic waves

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using a three-dimensional nonhydrostatic mesoscale numerical model (MM5), the evolution and structures of baroclinic waves with and without surface drag in case of dry and moist atmosphere are simulated, with special emphases on the effects of surface drag on the low-level frontal structure and frontogenesis. There are two different effects of surface drag on the low-level frontogenesis in the dry case. On one hand, the surface drag weakens the low-level frontogenesis and less inclined to develop the baroclinic wave due to the dissipation. But on the other hand, the surface drag induces a strong ageostrophic flow, which prolongs the low-level frontogenesis and finally leads to the enhancement of cold front. Compared with the no surface drag case, the surface drag increases the frontal slope espe- cially in the boundary layer, where the front is almost vertical to the surface, and then enhances the prefrontal vertical motion. All these conclusions expanded the analytical theory of Tan and Wu (1990). In the moist atmosphere, the influence of surface drag on frontal rainbands is also obvious. The surface drag weakens the convection, and reduces the energy dissipation near the surface when the initial relative humidity is relatively weak. At this time, the confluence induced post-frontal updrafts moves across the cold front and reinforces the prefrontal convection, which is beneficial to the maintenance of the rainband in cold sector. Given the enhancement of relative humidity, the moist convection domi- nates the low-level frontogenesis while the retardation of surface drag on energy dissipation is not obvious, therefore the effects of surface drag on the low-level frontogenesis and precipitation are re- duced.

  6. Improved 2D Intelligent Driver Model simulating synchronized flow and evolution concavity in traffic flow

    CERN Document Server

    Tian, Junfang; Li, Geng; Treiber, Martin; Zhu, Chenqiang; Jia, Bin

    2016-01-01

    This paper firstly show that 2 Dimensional Intelligent Driver Model (Jiang et al., PloS one, 9(4), e94351, 2014) is not able to replicate the synchronized traffic flow. Then we propose an improved model by considering the difference between the driving behaviors at high speeds and that at low speeds. Simulations show that the improved model can reproduce the phase transition from synchronized flow to wide moving jams, the spatiotemporal patterns of traffic flow induced by traffic bottleneck, and the evolution concavity of traffic oscillations (i.e. the standard deviation of the velocities of vehicles increases in a concave/linear way along the platoon). Validating results show that the empirical time series of traffic speed obtained from Floating Car Data can be well simulated as well.

  7. Elliptical concave microlens arrays built in the photosensitive TiO2/ormosils hybrid films

    Science.gov (United States)

    Zhang, Xuehua; Que, Wenxiu; Javed, Hafiz M. Asif; Wei, Wei

    2014-11-01

    Photosensitive TiO2/organically modified silane hybrid thin films were prepared by a low-temperature sol-gel spin-coating technique. Optical and structural properties of the hybrid films with different titanium contents were characterized by prism coupling technique, UV-visible spectroscopy, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. Advantages for fabrication of elliptical concave micro-lens arrays (MLAs) based on the as-prepared hybrid films were demonstrated by combining polydimethylsiloxane soft mold with a UV-cured imprint technique. Results indicate that the as-prepared hybrid films have great applicability for the fabrication of photonic components, and the fabrication technique provides a simple and cost-effective way for the fabrication of the sol-gel elliptical concave MLAs.

  8. Solution of an open problem for Schur convexity or concavity of the Gini mean values

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Schur convexity or concavity problem of the Gini mean values S(a, b; x, y) with respect to (x, y) ∈ (0, ∞) × (0, ∞) for fixed (a, b) ∈ R × R is still open. In this paper, we prove that S(a, b; x, y) is Schur convex with respect to (x, y) ∈ (0, ∞) × (0, ∞) if and only if (a, b) ∈ {(a, b) : a 0, b 0, a + b 1}, and Schur concave with respect to (x, y) ∈ (0, ∞) × (0, ∞) if and only if (a, b) ∈ {(a, b) : b 0, b a, a + b 1} ∪ {(a, b) : a 0, a b, a + b 1}.

  9. Solution of an open problem for Schur convexity or concavity of the Gini mean values

    Institute of Scientific and Technical Information of China (English)

    CHU YuMing; XIA WeiFeng

    2009-01-01

    The Schur convexity or concavity.problem of the Gini mean values S(a,b;x,y) with respect to (x,y)∈(0,∞) × (0,∞) for fixed (a,b)∈R×R is still open.In this paper,we prove that S(a,b;x,y) is Schur convex with respect to (x,y)∈(0,∞)× (0,∞) if and only if (a,b) ∈{(a,b):a≥0,b≥0,a+b≥1},and Schur concave with respect to (x,y)∈(0,∞)× (0,∞) if and only if (a,b)∈{(a,b):b≤0,b≤a,a+b≤1}∪{(a,b):a≤0,a≤b,a+b≤1}.

  10. The Virtual Private Network Design Problem with Concave Costs (Oberwolfach abstract)

    CERN Document Server

    Fiorini, Samuel; Sanità, Laura; Theis, Dirk Oliver

    2008-01-01

    The symmetric Virtual Private Network Design (VPND) problem is concerned with buying capacity on links (edges) in a communication network such that certain traffic demands can be met. We investigate a natural generalization of VPND where the cost per unit of capacity may decrease if a larger amount of capacity is reserved (economies of scale principle). The growth of the cost of capacity is modelled by a non-decreasing concave function $f$. We call the problem the concave symmetric Virtual Private Network Design (cVPND) problem. After showing that a generalization of the so-called Pyramidal Routing problem and hence also the cVPND have the so-called tree routing property, we study approximation algorithms for cVPND. For general $f$, using known results on the so-called Single Source Buy at Bulk problem by Grandoni and Italiano, we give a randomized 24.92-approximation algorithm.

  11. Sea level and turbidity controls on mangrove soil surface elevation change

    Science.gov (United States)

    Lovelock, Catherine E.; Adame, Maria Fernanda; Bennion, Vicki; Hayes, Matthew; Reef, Ruth; Santini, Nadia; Cahoon, Donald R.

    2015-02-01

    Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on the soil surface and belowground production of roots are proposed to increase with increasing sea level, enabling intertidal habitats to maintain their position relative to mean sea level, but there are few tests of these predictions in mangrove forests. Here we used variation in sea level and the availability of sediments caused by seasonal and inter-annual variation in the intensity of La Nina-El Nino to assess the effects of increasing sea level on surface elevation gains and contributing processes (accretion on the surface, subsidence and root growth) in mangrove forests. We found that soil surface elevation increased with mean sea level (which varied over 250 mm during the study) and with turbidity at sites where fine sediment in the water column is abundant. In contrast, where sediments were sandy, rates of surface elevation gain were high, but not significantly related to variation in turbidity, and were likely to be influenced by other factors that deliver sand to the mangrove forest. Root growth was not linked to soil surface elevation gains, although it was associated with reduced shallow subsidence, and therefore may contribute to the capacity of mangroves to keep pace with sea level rise. Our results indicate both surface (sedimentation) and subsurface (root growth) processes can influence mangrove capacity to keep pace with sea level rise within the same geographic location, and that current models of tidal marsh responses to sea level rise capture the major feature of the response of mangroves where fine, but not coarse, sediments are abundant.

  12. Surface Landau levels and spin states in bismuth (111) ultrathin films.

    Science.gov (United States)

    Du, Hongjian; Sun, Xia; Liu, Xiaogang; Wu, Xiaojun; Wang, Jufeng; Tian, Mingyang; Zhao, Aidi; Luo, Yi; Yang, Jinlong; Wang, Bing; Hou, J G

    2016-03-11

    The development of next-generation electronics is much dependent on the discovery of materials with exceptional surface-state spin and valley properties. Because of that, bismuth has attracted a renewed interest in recent years. However, despite extensive studies, the intrinsic electronic transport properties of Bi surfaces are largely undetermined due to the strong interference from the bulk. Here we report the unambiguous determination of the surface-state Landau levels in Bi (111) ultrathin films using scanning tunnelling microscopy under magnetic fields perpendicular to the surface. The Landau levels of the electron-like and the hole-like carriers are accurately characterized and well described by the band structure of the Bi (111) surface from density functional theory calculations. Some specific surface spin states with a large g-factor are identified. Our findings shed light on the exploiting surface-state properties of Bi for their applications in spintronics and valleytronics.

  13. Monotone Concave Operators: An application to the existence and uniqueness of solutions to the Bellman equation

    OpenAIRE

    Cuong LE VAN; Morhaim, Lisa; Vailakis, Yiannis

    2008-01-01

    We propose a new approach to the issue of existence and uniqueness of solutions to the Bellman equation, exploiting an emerging class of methods, called monotone map methods, pioneered in the work of Krasnosel’skii (1964) and Krasnosel’skii-Zabreiko (1984). The approach is technically simple and intuitive. It is derived from geometric ideas related to the study of fixed points for monotone concave operators defined on partially order spaces.

  14. Matrix decomposition and Lagrangian dual method for discrete portfolio optimization under concave transaction costs

    Institute of Scientific and Technical Information of China (English)

    GAO Zhen-xing; ZHANG Shi-tao; SUN Xiao-ling

    2009-01-01

    In this paper, the discrete mean-variance model is considered for portfolio selection under concave transaction costs. By using the Cholesky decomposition technique, the convariance matrix to obtain a separable mixed integer nonlinear optimization problem is decomposed. A brand-and-bound algorithm based on Lagrangian relaxation is then proposed. Com-putational results are reported for test problems with the data randomly generated and those from the US stock market.

  15. Multiple positive solutions for Kirchhoff type problems involving concave and convex nonlinearities in R^3

    Directory of Open Access Journals (Sweden)

    Xiaofei Cao

    2016-11-01

    Full Text Available In this article, we consider the multiplicity of positive solutions for a class of Kirchhoff type problems with concave and convex nonlinearities. Under appropriate assumptions, we prove that the problem has at least two positive solutions, moreover, one of which is a positive ground state solution. Our approach is mainly based on the Nehari manifold, Ekeland variational principle and the theory of Lagrange multipliers.

  16. The concave versus convex approach for minimally invasive lateral lumbar interbody fusion for thoracolumbar degenerative scoliosis.

    Science.gov (United States)

    Scheer, Justin K; Khanna, Ryan; Lopez, Alejandro J; Fessler, Richard G; Koski, Tyler R; Smith, Zachary A; Dahdaleh, Nader S

    2015-10-01

    We retrospectively reviewed patient charts to compare the approach-related (convex versus concave) neurological complications and magnitude of correction in patients undergoing lateral lumbar interbody fusion (LLIF). It is yet to be quantitatively determined if correction of adult degenerative scoliosis from either side of the curve apex using a LLIF results in a reduction in complications and/or improved corrective ability. The inclusion criteria for this study were patients who underwent a LLIF for adult degenerative thoracolumbar scoliosis and had the LLIF prior to any other supplemental procedures. Patients were grouped based on the approach toward the curve apex concavity (CAVE) or the convexity (VEX). Standard coronal and sagittal radiographic measurements were made. Neurological complications and reoperation indications were also recorded. We included 32 patients for review (CAVE: 17; VEX: 15) with a mean age of 65.5 years±a standard deviation of 10.2, and mean follow-up of 17.0 months±15.7. There were eight postoperative neurological complications in eight patients (25.0%), and seven reoperations for six patients (18.8%; CAVE: 4/17 [23.5%]; VEX: 2/15 [13.3%]). The CAVE group had 6/17 neurological complications (35.3%; four ipsilateral and two contralateral to approach side) and VEX had 2/15 (13.3%; one ipsilateral and one bilateral to approach side; p>0.05). All patients significantly improved in the mean regional and segmental Cobb angles (p0.05). There were no significant differences between the groups for any of the radiographic parameters measured (p>0.05). Approaching the curve apex from either the concave or convex side resulted in significant improvements. The concave approach was associated with more postoperative neurological complications.

  17. Special function related to the concave-convex boundary problem of the diffraction theory

    CERN Document Server

    Kazakov, A Y

    2003-01-01

    The concave-convex boundary problem of the diffraction theory is studied. It corresponds to the scattering of a whispering gallery mode on the point of inflection of the boundary. A new special function related to this boundary problem is introduced and its particular properties are discussed. This special function is defined as a contour integral on the complex plane and its behaviour in different domains of parameters is considered.

  18. Concave Cu-Pd bimetallic nanocrystals: Ligand-based Co-reduction and mechanistic study

    Institute of Scientific and Technical Information of China (English)

    Lan Zhang[1; Hongyang Su[1; Mei Sun[1; Youcheng Wang[1; Wenlong Wu[1; Taekyung Yu[2; Jie Zeng[1

    2015-01-01

    The synthesis of highly uniform alloy nanocrystals with a concave feature is desirable for applications in catalysis but is an arduous task. This article proposes an initiative protocol for the fabrication of novel Cu-Pd alloy nanocrystals, wherein the volume of decylamine (DA) in the reaction system was found to greatly influence the formation of different morphologies, including the tetrahedron (TH), concave tetrahedron (CTH), rhombohedral-tetrapod (RTP), and tetrapod (TP). The alloy structure of the products arises from the coordination interaction between the DA and metal ions, which affects the reduction potential of Cu and Pd species, and thus yields co-reduction. Other reaction parameters, such as the type of ligand, amount of reductant, and temperature, were also altered to study the growth mechanism, yielding consistent conclusions in the diffusion-controlled regime. As a catalyst, 48-nm Cu-Pd concave tetrahedral nanocrystals were highly active for the hydrogenation of 3-nitrostyrene and exhibited 〉99.9% chemoselectivity to C=C instead of-NO2.

  19. Hydrophobic concave surfaces and cavities by combination of calix[4]arenes and resorcin[4]arenes

    NARCIS (Netherlands)

    Timmerman, P.; Nierop, Klaas G.A.; Brinks, Erik A.; Verboom, Willem; van Veggel, F.C.J.M.; van Hoorn, Willem P.; van Hoorn, W.P.; Reinhoudt, David

    1995-01-01

    A general approach to the family of completely spirocyclopropanated macrocyclic polydiacetylenes, that is, cyclic dehydrooligomers of 1,1-diethynylcyclopropane 4, is reported. The characterized examples of these 'exploding' [n]rotanes are for n = 5, 6, 7, 8, 9, 10, and 12. X-ray crystal structure

  20. Alternative hypotheses to explain why biodiversity-ecosystem functioning relationships are concave-up in some natural ecosystems but concave-down in manipulative experiments.

    Science.gov (United States)

    Mora, Camilo; Danovaro, Roberto; Loreau, Michel

    2014-06-25

    Recent studies of the relationship between biodiversity and functioning in marine ecosystems have yielded non-saturating patterns that contrast sharply with the results of experimental studies, where ecosystem functioning rapidly saturates with increases in biodiversity. Here we provide a simple theoretical framework of three alternative hypotheses that, individually or combined, are likely to explain this contrast: i) the use of functional richness instead of species richness, ii) an increased production efficiency of species in producing biomass when more ecological interactions are present, and iii) the fact that communities are likely assembled in an ordered succession of species from low to high ecological efficiency. Our results provide theoretical support for concave-up biodiversity-ecosystem functioning relationships in natural ecosystems and confirm that the loss of species can have substantially larger effects on the functioning of natural ecosystems than anticipated from controlled manipulative experiments.

  1. Surface solar ultraviolet radiation for paleoatmospheric levels of oxygen and ozone

    Science.gov (United States)

    Levine, J. S.

    1980-01-01

    Many investigators have concluded that the level of solar ultraviolet radiation (200-300 nm) reaching the surface was a key parameter in the origin and evolution of life on earth. The level of solar ultraviolet radiation between 200 and 300 nm is controlled primarily by molecular absorption by ozone, whose presence is strongly coupled to the level of molecular oxygen. In this paper, a series of calculations is presented of the solar ultraviolet radiation reaching the surface for oxygen levels ranging from 0.0001 the present atmospheric level to the present level. The solar spectrum between 200 and 300 nm has been divided into 34 spectral intervals. For each spectral interval, the solar ultraviolet radiation reaching the earth's surface has been calculated by considering the attenuation of the incoming beam due to ozone and oxygen absorption. A one-dimensional photochemical model of the atmosphere was used for these calculations.

  2. Seamless lamination of a concave-convex architecture with single-layer graphene

    Science.gov (United States)

    Park, Ji-Hoon; Lim, Taekyung; Baik, Jaeyoon; Seo, Keumyoung; Moon, Youngkwon; Park, Noejung; Shin, Hyun-Joon; Kyu Kwak, Sang; Ju, Sanghyun; Real Ahn, Joung

    2015-10-01

    Graphene has been used as an electrode and channel material in electronic devices because of its superior physical properties. Recently, electronic devices have changed from a planar to a complicated three-dimensional (3D) geometry to overcome the limitations of planar devices. The evolution of electronic devices requires that graphene be adaptable to a 3D substrate. Here, we demonstrate that chemical-vapor-deposited single-layer graphene can be transferred onto a silicon dioxide substrate with a 3D geometry, such as a concave-convex architecture. A variety of silicon dioxide concave-convex architectures were uniformly and seamlessly laminated with graphene using a thermal treatment. The planar graphene was stretched to cover the concave-convex architecture, and the resulting strain on the curved graphene was spatially resolved by confocal Raman spectroscopy; molecular dynamic simulations were also conducted and supported the observations. Changes in electrical resistivity caused by the spatially varying strain induced as the graphene-silicon dioxide laminate varies dimensionally from 2D to 3D were measured by using a four-point probe. The resistivity measurements suggest that the electrical resistivity can be systematically controlled by the 3D geometry of the graphene-silicon dioxide laminate. This 3D graphene-insulator laminate will broaden the range of graphene applications beyond planar structures to 3D materials.Graphene has been used as an electrode and channel material in electronic devices because of its superior physical properties. Recently, electronic devices have changed from a planar to a complicated three-dimensional (3D) geometry to overcome the limitations of planar devices. The evolution of electronic devices requires that graphene be adaptable to a 3D substrate. Here, we demonstrate that chemical-vapor-deposited single-layer graphene can be transferred onto a silicon dioxide substrate with a 3D geometry, such as a concave-convex architecture. A

  3. Mapping Urban Impervious Surface by Fusing Optical and SAR Data at the Decision Level

    Directory of Open Access Journals (Sweden)

    Zhenfeng Shao

    2016-11-01

    Full Text Available The proliferation of impervious surfaces results in a series of environmental issues, such as the decrease of vegetated areas and the aggravation of the urban heat island effects. The mapping of impervious surface and its spatial distributions is of significance for the ecological study of urban environment. Currently, the integration of optical and synthetic aperture radar (SAR data has shown advantages in accurately characterizing impervious surface. However, the fusion mainly occurs at the pixel and feature levels which are subject to influences of data noises and feature selections, respectively. In this paper, an innovative and effective method was developed to extract urban impervious surface by synergistically utilizing optical and SAR images at the decision level. The objective of this paper was to obtain an accurate urban impervious surface map based on the random forest classifier and the evidence theory and to provide a detailed uncertainty analysis accompanying the fused impervious surface maps. In this study, both the GaoFen (GF-1 and Sentinel-1A imagery were first used as independent data sources for mapping urban impervious surfaces. Then additional spectral features and texture features were extracted and integrated with the original GF-1 and Sentinel-1A images in generating impervious surfaces. Finally, based on the Dempster-Shafer (D-S theory, impervious surfaces were produced by fusing the previously estimated impervious surfaces from different datasets at the decision level. Results showed that impervious surfaces estimated from the combined use of original images and features yielded a higher accuracy than those from the original optical or SAR data. Further validations suggested that optical data was better than SAR data in separating impervious surfaces from non-impervious surfaces. The fused impervious surfaces at the decision level had a higher overall accuracy than those produced independently by optical or SAR data. It

  4. Concave Pd-Pt Core-Shell Nanocrystals with Ultrathin Pt Shell Feature and Enhanced Catalytic Performance.

    Science.gov (United States)

    Zhang, Ying; Bu, Lingzheng; Jiang, Kezhu; Guo, Shaojun; Huang, Xiaoqing

    2016-02-10

    One-pot creation of unique concave Pd-Pt core-shell polyhedra has been developed for the first time using an efficient approach. Due to the concave feature and ultrathin Pt shell, the created Pd-Pt core-shell polyhedra exhibit enhanced catalytic performance in both the electrooxidation of methanol and hydrogenation of nitrobenzene, as compared with commercial Pt black and Pd black catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Effect of a concave grid mesh in a carbon nanotube-based field emission X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Suk; Castro, Edward Joseph D. [Regional Innovation Center for Next Generation Industrial Radiation Technology, Division of Microelectronics and Display Technology, Iksan (Korea, Republic of); Lee, Choong Hun, E-mail: chlee12345@gmail.com [Regional Innovation Center for Next Generation Industrial Radiation Technology, Division of Microelectronics and Display Technology, Iksan (Korea, Republic of); Solar Cell Research Institute, Wonkwang University, Iksan (Korea, Republic of)

    2014-10-15

    Highlights: • Successful design using a concave grid mesh for the focusing electron. • Much better X-ray image due to the concave grid mesh. • Higher anode current efficiency using the concave grid mesh versus a flat grid mesh. - Abstract: This study introduces a simple approach to improve the X-ray image quality produced by the carbon nanotube (CNT) field emitter X-ray source by altering the geometrical shape of the grid mesh from the conventional flat shape to a concave one in a typical triode structure. The concave shape of the grid electrode increases the effective number of the grid cells in the mesh, which exerted an electric field in the direction of the emitted electrons, thereby increasing the emission current reaching the anode. Furthermore, the curved mesh (concave grid mesh), which was responsible for the extraction of electrons from the field emitter, exhibited a focusing effect on the electron beam trajectory thereby, reducing the focal spot size impinging on the anode and resulted in a better spatial resolution of the X-ray images produced.

  6. Flat-ramp vs. convex-concave thrust geometries in a deformable hanging wall: new insights from analogue modeling experiments

    Science.gov (United States)

    Almeida, Pedro; Tomas, Ricardo; Rosas, Filipe; Duarte, Joao; Terrinha, Pedro

    2015-04-01

    Different modes of strain accommodation affecting a deformable hanging-wall in a flat-ramp-flat thrust system were previously addressed through several (sandbox) analog modeling studies, focusing on the influence of different variables, such as: a) thrust ramp dip angle and friction (Bonini et al, 2000); b) prescribed thickness of the hanging-wall (Koy and Maillot, 2007); and c) sin-thrust erosion (compensating for topographic thrust edification, e.g. Persson and Sokoutis, 2002). In the present work we reproduce the same experimental procedure to investigate the influence of two different parameters on hanging-wall deformation: 1) the geometry of the thrusting surface; and 2) the absence of a velocity discontinuity (VD) that is always present in previous similar analogue modeling studies. Considering the first variable we use two end member ramp geometries, flat-ramp-flat and convex-concave, to understand the control exerted by the abrupt ramp edges in the hanging-wall stress-strain distribution, comparing the obtain results with the situation in which such edge singularities are absent (convex-concave thrust ramp). Considering the second investigated parameter, our motivation was the recognition that the VD found in the different analogue modeling settings simply does not exist in nature, despite the fact that it has a major influence on strain accommodation in the deformable hanging-wall. We thus eliminate such apparatus artifact from our models and compare the obtained results with the previous ones. Our preliminary results suggest that both investigated variables play a non-negligible role on the structural style characterizing the hanging-wall deformation of convergent tectonic settings were such thrust-ramp systems were recognized. Acknowledgments This work was sponsored by the Fundação para a Ciência e a Tecnologia (FCT) through project MODELINK EXPL/GEO-GEO/0714/2013. Pedro Almeida wants to thank to FCT for the Ph.D. grant (SFRH/BD/52556/2014) under the

  7. A Level Set Discontinuous Galerkin Method for Free Surface Flows - and Water-Wave Modeling

    DEFF Research Database (Denmark)

    Grooss, Jesper

    2005-01-01

    We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by a level set technique. We describe the discontinuous Galerkin method in general, and its application to the flow equations....... The deferred correction method is applied on the fluid flow equations and show good results in periodic domains. We describe the design of a level set method for the free surface modeling. The level set utilize the high order accurate discontinuous Galerkin method fully and represent smooth surfaces very...... equations in time are discussed. We investigate theory of di erential algebraic equations, and connect the theory to current methods for solving the unsteady fluid flow equations. We explore the use of a semi-implicit spectral deferred correction method having potential to achieve high temporal order...

  8. A Level Set Discontinuous Galerkin Method for Free Surface Flows - and Water-Wave Modeling

    DEFF Research Database (Denmark)

    Grooss, Jesper

    2005-01-01

    We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by a level set technique. We describe the discontinuous Galerkin method in general, and its application to the flow equations....... accurately. We present techniques for reinitialization, and outline the strengths and weaknesses of the level set method. Through a few numerical tests, the robustness and versatility of the proposed scheme is confirmed.......We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by a level set technique. We describe the discontinuous Galerkin method in general, and its application to the flow equations....... The deferred correction method is applied on the fluid flow equations and show good results in periodic domains. We describe the design of a level set method for the free surface modeling. The level set utilize the high order accurate discontinuous Galerkin method fully and represent smooth surfaces very...

  9. Prediction of the mid-tracheal level using surface anatomical landmarks in adults

    Science.gov (United States)

    Jang, Young-Eun; Kim, Eun-Hee; Song, In-Kyung; Lee, Ji-Hyun; Ryu, Ho-Geoul; Kim, Hee-Soo; Kim, Jin-Tae

    2017-01-01

    Abstract Endotracheal tube (ETT) should be placed at the optimal level to avoid single lung ventilation or accidental extubation. This study was performed to estimate the mid-tracheal level by using surface anatomical landmarks in adult patients. Neck computed tomography images of 329 adult patients between the ages of 16 and 79 years were reviewed. In the midline sagittal plane, the levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified. The surface distances from the cricoid cartilage to the suprasternal notch (extCC-SSN) and that from the suprasternal notch to the manubriosternal junction (extSSN-MSJ) were measured. The relationship between mid-tracheal level and the surface distances was analyzed using Bland–Altman plot. The difference between the extCC-SSN and the mid-tracheal level was −6.6 (12.5) mm, and the difference between the extSSN-MSJ and the mid-tracheal level was −19.2 (6.1) mm. The difference between the extCC-SSN and the mid-tracheal level was smaller in females compared with males [−1.7 (11.7) mm vs −12.8 (10.7) mm; P < 0.001]. The mid-tracheal level, which is helpful in planning the insertion depth of an ETT, can be predicted by the surface distance between the cricoid cartilage and suprasternal notch in adults, especially in females. PMID:28328810

  10. 3D modelling of interaction of strongly nonlinear internal seiches with a concave lake topography and a phenomenon of the "lake monsters".

    Science.gov (United States)

    Terletska, Kateryna; Maderich, Vladimir; Brovchenko, Igor; Jung, Kyung Tae

    2013-04-01

    In the freshwater lakes in moderate latitudes stratification occurs as a result of the seasonal warming of the surface water layer. Than the intense wind surges (usually in autumn) tilt the surface and generate long basin-scale low-frequency standing internal waves (seiches). Depending on the initial interface tilt and stratification wide spectra of possible flow regimes can be observed [1]-[2].They varied from small amplitude symmetric seiches to large amplitude nonlinear waves.Nonlinearity leads to an asymmetry of internal waves and appearance of the surge or bore and further disintegration of it on a sequence of solitary waves. In present study degeneration of the strongly nonlinear internal seiches in elongated lakes with a concave "spoon-like" topography is investigated.Two different three-dimensional non-hydrostatic free-surface numerical models are used to investigate degeneration of large internal waves and its subsequent interaction with the concave lake slope. One of this model is non-hydrostatic model [3] and the other is a well-known MIT model. At first we consider idealized elongated elliptic-shape lake with the dimension of 5 km X 1 km with the maximal depth 30 m. The stratification in lake is assumed to be given in a form of the tangent function with a density difference between upper and lower layers 2 kgm-3 . It is assumed that motion in such lake is initiated by inclination of thermocline on a certain angle. Than lake adjusts to return to its original state producing internal seiches which begin interacting with a bottom topography. The process of degeneration of internal seiches in the lake with concave ends consist of chain of elementary processes: 1) steeping of long basin scale large amplitude wave, that evolve into internal surge, 2) surge interact with concave lake ends that leads the concentration of the flow and formation of down slope bottom jet along the lake axis, 3) due to cumulative effect local velocity in the jet accelerates up to

  11. A histopathological evaluation of a concave-shaped low-intensity band on T1-weighted MR images in a subchondral insufficiency fracture of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Garida; Ikemura, Satoshi; Nakashima, Yasuharu; Mawatari, Taro; Motomura, Goro; Iwamoto, Yukihide [Kyushu University, Department of Orthopaedic Surgery, Fukuoka (Japan); Yamamoto, Takuaki [Kyushu University, Department of Orthopaedic Surgery, Fukuoka (Japan); Kyushu University, Department of Orthopaedic Surgery, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan)

    2010-02-15

    A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped low-intensity area just beneath the articular cartilage as well as a low-intensity band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-intensity band observed on the T1-weighted image. (orig.)

  12. Limit Distribution Theory for Maximum Likelihood Estimation of a Log-Concave Density.

    Science.gov (United States)

    Balabdaoui, Fadoua; Rufibach, Kaspar; Wellner, Jon A

    2009-06-01

    We find limiting distributions of the nonparametric maximum likelihood estimator (MLE) of a log-concave density, i.e. a density of the form f(0) = exp varphi(0) where varphi(0) is a concave function on R. Existence, form, characterizations and uniform rates of convergence of the MLE are given by Rufibach (2006) and Dümbgen and Rufibach (2007). The characterization of the log-concave MLE in terms of distribution functions is the same (up to sign) as the characterization of the least squares estimator of a convex density on [0, infinity) as studied by Groeneboom, Jongbloed and Wellner (2001b). We use this connection to show that the limiting distributions of the MLE and its derivative are, under comparable smoothness assumptions, the same (up to sign) as in the convex density estimation problem. In particular, changing the smoothness assumptions of Groeneboom, Jongbloed and Wellner (2001b) slightly by allowing some higher derivatives to vanish at the point of interest, we find that the pointwise limiting distributions depend on the second and third derivatives at 0 of H(k), the "lower invelope" of an integrated Brownian motion process minus a drift term depending on the number of vanishing derivatives of varphi(0) = log f(0) at the point of interest. We also establish the limiting distribution of the resulting estimator of the mode M(f(0)) and establish a new local asymptotic minimax lower bound which shows the optimality of our mode estimator in terms of both rate of convergence and dependence of constants on population values.

  13. Repair of facial concave deformity%面部凹陷畸形的修复

    Institute of Scientific and Technical Information of China (English)

    熊爱兵; 郭力; 吴国平

    2008-01-01

    Objective To investigate two techniques and outcome in repairing facial concave deficits.Methods Eleven patients with facial concave deformity were included in this study:nine were treated with autologous fat granule injection,1,3 and 5 patients were given fat granules injection fourth,twice and once,respectivly.The other 2 patients were repaired with homolateral temporal fascia flap.Results The implantation by using autologous fat granules in all 9 patients showed excellent results.Homolateral temporal fascia flaps were used in 2 cases,one of which was formed hematoma after operation and scavenged thereafter.All the patients had satisfactory results.Conclusion Both approaches well rehabilitate patients' facial contour,and thus are capable of repairing moderate or minimal facial concave deficit and worth recommendation.%目的 探讨面部凹陷畸形的修复方法及其效果.方法 对面部凹陷畸形患者11例,采用自体脂肪颗粒注射移植9例:其中1例注射4次,3例注射2次,其余5例均注射1次.同侧岛状颞筋膜瓣修复2例.结果 9例自体脂肪颗粒注射移植者,效果满意.2例同侧岛状颞筋膜瓣修复者,其中1例术后形成血肿,予以清除,效果亦均较满意.结论 自体脂肪颗粒注射移植及同侧岛状颞筋膜瓣移植对轻、中度面部凹陷畸形的修复不失为一良好方法,值得推广.

  14. Inference from concave stochastic frontiers and the covariance of firm efficiency measures across firms

    Energy Technology Data Exchange (ETDEWEB)

    Dashti, Imad [Kuwait Univ., Economics Dept., Kuwait (Kuwait)

    2003-11-01

    This paper uses a Bayesian stochastic frontier model to obtain confidence intervals on firm efficiency measures of electric utilities rather than the point estimates reported in most previous studies. Results reveal that the stochastic frontier model yields imprecise measures of firm efficiency. However, the application produces much more precise inference on pairwise efficiency comparisons of firms due to a sometimes strong positive covariance of efficiency measures across firms. In addition, we examine the sensitivity to functional form by repeating the analysis for Cobb-Douglas, translog and Fourier frontiers, with and without imposing monotonicity and concavity. (Author)

  15. Is There Asymmetry Between the Concave and Convex Pedicles in Adolescent Idiopathic Scoliosis? A CT Investigation.

    Science.gov (United States)

    Davis, Colin M; Grant, Caroline A; Pearcy, Mark J; Askin, Geoffrey N; Labrom, Robert D; Izatt, Maree T; Adam, Clayton J; Little, J Paige

    2017-03-01

    Adolescent idiopathic scoliosis is a complex three-dimensional deformity of the spine characterized by deformities in the sagittal, coronal, and axial planes. Spinal fusion using pedicle screw instrumentation is a widely used method for surgical correction in severe (coronal deformity, Cobb angle > 45°) adolescent idiopathic scoliosis curves. Understanding the anatomic difference in the pedicles of patients with adolescent idiopathic scoliosis is essential to reduce the risk of neurovascular or visceral injury through pedicle screw misplacement. To use CT scans (1) to analyze pedicle anatomy in the adolescent thoracic scoliotic spine comparing concave and convex pedicles and (2) to assess the intra- and interobserver reliability of these measurements to provide critical information to spine surgeons regarding size, length, and angle of projection. Between 2007 and 2009, 27 patients with adolescent idiopathic scoliosis underwent thoracoscopic anterior correction surgery by two experienced spinal surgeons. Preoperatively, each patient underwent a CT scan as was their standard of care at that time. Twenty-two patients (mean age, 15.7 years; SD, 2.4 years; range, 11.6-22 years) (mean Cobb angle, 53°; SD, 5.3°; range, 42°-63°) were selected. Inclusion criteria were a clinical diagnosis of adolescent idiopathic scoliosis, female, and Lenke type 1 adolescent idiopathic scoliosis with the major curve confined to the thoracic spine. Using three-dimensional image analysis software, the pedicle width, inner cortical pedicle width, pedicle height, inner cortical pedicle height, pedicle length, chord length, transverse pedicle angle, and sagittal pedicle angles were measured. Randomly selected scans were remeasured by two of the authors and the reproducibility of the measurement definitions was validated through limit of agreement analysis. The concave pedicle widths were smaller compared with the convex pedicle widths at T7, T8, and T9 by 37% (3.44 mm ± 1.16 mm vs 4

  16. Optimal transportation network with concave cost functions: loop analysis and algorithms.

    Science.gov (United States)

    Shao, Zhen; Zhou, Haijun

    2007-06-01

    Transportation networks play a vital role in modern societies. Structural optimization of a transportation system under a given set of constraints is an issue of great practical importance. For a general transportation system whose total cost C is determined by C = Sigma(ioptimal network topology is a tree if C(ij) proportional |I(ij)|(gamma) with 0 optimality of tree-formed networks is given. The simple intuitive picture of this proof then leads to an efficient global algorithm for the searching of optimal structures for a given transportation system with concave cost functions.

  17. Double-concave Lens Thickness and Refractive Index Determination of the Radius of Curvature%双凹厚透镜曲率半径和折射率的测定

    Institute of Scientific and Technical Information of China (English)

    徐建丽; 顾菊观; 张良锋

    2011-01-01

    It observes the image caused by spherical refraction of double-concave lens,utilizes this experimental phenomenon combined the image formula to determine the refractive index and curvature radius of double thick lens lens's front and back surface.It may extract the concave-concave thick lens' radius of curvature using two spherical surface catoptrical imaging,two methods can be comparable.This method can correct the error caused by neglecting lens thickness in the measurement of thin lens.%观察双凹厚透镜的球面反射成像,利用这一实验现象结合物像公式测定双凹厚透镜前后表面的曲率半径和折射率。利用两次球面反射成像可求出双凹厚透镜的曲率半径,两种方法可比较。对于薄透镜,这种方法可以修正在实际测量中忽略透镜厚度所产生的误差。

  18. Synergistic prevention of biofouling in seawater desalination by zwitterionic surfaces and low-level chlorination.

    Science.gov (United States)

    Yang, Rong; Jang, Hongchul; Stocker, Roman; Gleason, Karen K

    2014-03-19

    Smooth, durable, ultrathin antifouling layers are deposited onto commercial reverse osmosis membranes without damaging them and they exhibit a fouling reduction. A new synergistic approach to antifouling, by coupling surface modification and drinking-water-level chlorination is enabled by the films' unique resistance against chlorine degradation. This approach substantially enhances longer-term fouling resistance compared with surface modification or chlorination alone, and can reduce freshwater production cost and its collateral toxicity to marine biota.

  19. A statistical method to get surface level air-temperature from satellite observations of precipitable water

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Shikauchi, A.; Sugimori, Y.; Kubota, M.

    Vol. 49, pp. 551 to 558. 1993 A Statistical Method to Get Surface Level Air-Temperature from Satellite Observations of Precipitable Water PANKAJAKSHAN THADATHIL*, AKIRA SHIKAUCHI, YASUHIRO SUGIMORI and MASAHISA KUBOTA School of Marine Science... observations for getting the estimates of heat flux across the air-sea boundary (Miller, 1981; Liu, 1988). Bulk method has widely been used for this purpose and the parameters required are: sea surface temperature, and wind speed, air-temperature and specific...

  20. [Optimization of broad-band flat-field holographic concave grating without astigmatism].

    Science.gov (United States)

    Kong, Peng; Tang, Yu-guo; Bayanheshig; Li, Wen-hao; Cui, Jin-jiang

    2012-02-01

    The desirable imaging locations of the flat-field holographic concave gratings should be in a plane. And the object can be imaged perfectly by the grating when the tangential focal curve and sagittal focal curve both superpose the intersection of the image plane and dispersion plane. But actually, the defocus can not be eliminated over the entire wavelength range, while the astigmatism vanishes when the grating parameters satisfy some conditions. An optimization method for broad-band flat-field holographic concave gratings with absolute astigmatism correction was proposed. The ray tracing software ZEMAX was used for investigating the imaging properties of the grating. And we made a comparison between spectral performance of gratings designed by this new method and that by conventional method, respectively. The results indicated that the spectral performance of gratings designed by using the absolute astigmatism correction method can be as good as gratings designed with the conventional method. And the focusing performance in the sagittal direction is much better, so that the S/N ratio can be greatly improved.

  1. Pebble bed structures in the vicinity of concave and convex walls

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Joerg, E-mail: reimann-langhans@web.de [Karlsruhe Institute of Technology, Karlsruhe (Germany); Brun, Emmanuel [European Synchrotron Radiation Facility, Grenoble (France); Ludwig-Maximilians-University, Garching (Germany); Ferrero, Claudio [European Synchrotron Radiation Facility, Grenoble (France); Vicente, Jérôme [Polytech Marseille, Marseille (France)

    2015-10-15

    Highlights: • Detailed tomography experiments were performed to study the packing structure close to concave and convex walls. • A model for arbitrary container geometries is proposed to predict the inner packing factor based on the known total packing factor. • The results are important for the design of ceramic breeder blankets. • The results are relevant for models describing the thermo-mechanical interaction of pebble beds with the blanket structure. - Abstract: Computed tomography experiments were performed with mostly spherical particles in containers with concave, plane and convex walls. Regular pebble packings exist also close to convex cylindrical walls even if the cylinder-to-pebble diameter ratio is about 1, characteristic of thermocouples within the pebble bed. A model for arbitrary container shapes is proposed which predicts the inner packing factor based on the known total packing factor. With increasing vibration efficiency the total packing factor rises because the zones with structured packing increase. Depending on container dimensions, a structured packing can occur in the total pebble bed. Large packing factors are desirable, however, these pebble beds can probably no longer be considered as isotropic with respect to thermo-mechanic properties.

  2. First-principles calculation of core-level binding energy shift in surface chemical processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Combined with third generation synchrotron radiation light sources, X-ray photoelectron spectroscopy (XPS) with higher energy resolution, brilliance, enhanced surface sensitivity and photoemission cross section in real time found extensive applications in solid-gas interface chemistry. This paper reports the calculation of the core-level binding energy shifts (CLS) using the first-principles density functional theory. The interplay between the CLS calculations and XPS measurements to uncover the structures, adsorption sites and chemical reactions in complex surface chemical processes are highlight. Its application on clean low index (111) and vicinal transition metal surfaces, molecular adsorption in terms of sites and configuration, and reaction kinetics are domonstrated.

  3. Gait Characteristics Associated with Trip-Induced Falls on Level and Sloped Irregular Surfaces

    Directory of Open Access Journals (Sweden)

    Andrew Merryweather

    2011-11-01

    Full Text Available Same level falls continue to contribute to an alarming number of slip/trip/fall injuries in the mining workforce. The objective of this study was to investigate how walking on different surface types and transverse slopes influences gait parameters that may be associated with a trip event. Gait analysis was performed for ten subjects on two orientations (level and sloped on smooth, hard surface (control and irregular (gravel, larger rocks surfaces. Walking on irregular surfaces significantly increased toe clearance compared to walking on the smooth surface. There was a significant (p < 0.05 decrease in cadence (steps/min, stride length (m, and speed (m/s from control to gravel to larger rocks. Significant changes in external rotation and increased knee flexion while walking on irregular surfaces were observed. Toe and heel clearance requirements increased on irregular surfaces, which may provide an explanation for trip-induced falls; however, the gait alterations observed in the experienced workers used as subjects would likely improve stability and recovery from a trip.

  4. 5-level polysilicon surface micromachine technology: Application to complex mechanical systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, M.S.; Sniegowski, J.J.

    1998-06-01

    The authors recently reported on the development of a 5-level poly-ilicon surface micromachine fabrication process consisting of four levels of mechanical poly plus an electrical interconnect layer. They are now reporting on the first components designed for and fabricated in this process. These are demonstration systems, which definitively show that five levels of polysilicon provide greater performance, reliability, and significantly increased functionality. This new technology makes it possible to realize levels of system complexity that have so far only existed on paper, while simultaneously adding to the robustness of many of the individual subassemblies.

  5. L2CXCV: A Fortran 77 package for least squares convex/concave data smoothing

    Science.gov (United States)

    Demetriou, I. C.

    2006-04-01

    Fortran 77 software is given for least squares smoothing to data values contaminated by random errors subject to one sign change in the second divided differences of the smoothed values, where the location of the sign change is also unknown of the optimization problem. A highly useful description of the constraints is that they follow from the assumption of initially increasing and subsequently decreasing rates of change, or vice versa, of the process considered. The underlying algorithm partitions the data into two disjoint sets of adjacent data and calculates the required fit by solving a strictly convex quadratic programming problem for each set. The piecewise linear interpolant to the fit is convex on the first set and concave on the other one. The partition into suitable sets is achieved by a finite iterative algorithm, which is made quite efficient because of the interactions of the quadratic programming problems on consecutive data. The algorithm obtains the solution by employing no more quadratic programming calculations over subranges of data than twice the number of the divided differences constraints. The quadratic programming technique makes use of active sets and takes advantage of a B-spline representation of the smoothed values that allows some efficient updating procedures. The entire code required to implement the method is 2920 Fortran lines. The package has been tested on a variety of data sets and it has performed very efficiently, terminating in an overall number of active set changes over subranges of data that is only proportional to the number of data. The results suggest that the package can be used for very large numbers of data values. Some examples with output are provided to help new users and exhibit certain features of the software. Important applications of the smoothing technique may be found in calculating a sigmoid approximation, which is a common topic in various contexts in applications in disciplines like physics, economics

  6. Statistical analysis of global surface air temperature and sea level using cointegration methods

    DEFF Research Database (Denmark)

    Schmith, Torben; Johansen, Søren; Thejll, Peter

    Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to physically-based models being unable to simulate observed sea level trends, semi-empirical models have been applied as an alternative for projecting...... of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and surface air temperature, capable of handling such peculiarities. We find a relationship between sea...... level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s is exceptional in the sense that sea level and warming deviates from the expected...

  7. Development, characterization, and optimization of protein level in date bars using response surface methodology.

    Science.gov (United States)

    Nadeem, Muhammad; Salim-ur-Rehman; Muhammad Anjum, Faqir; Murtaza, Mian Anjum; Mueen-ud-Din, Ghulam

    2012-01-01

    This project was designed to produce a nourishing date bar with commercial value especially for school going children to meet their body development requirements. Protein level of date bars was optimized using response surface methodology (RSM). Economical and underutilized sources, that is, whey protein concentrate and vetch protein isolates, were explored for protein supplementation. Fourteen date bar treatments were produced using a central composite design (CCD) with 2 variables and 3 levels for each variable. Date bars were then analyzed for nutritional profile. Proximate composition revealed that addition of whey protein concentrate and vetch protein isolates improved the nutritional profile of date bars. Protein level, texture, and taste were considerably improved by incorporating 6.05% whey protein concentrate and 4.35% vetch protein isolates in date bar without affecting any sensory characteristics during storage. Response surface methodology was observed as an economical and effective tool to optimize the ingredient level and to discriminate the interactive effects of independent variables.

  8. Dust emissions created by low-level rotary-winged aircraft flight over desert surfaces

    Science.gov (United States)

    Gillies, J. A.; Etyemezian, V.; Kuhns, H.; McAlpine, J. D.; King, J.; Uppapalli, S.; Nikolich, G.; Engelbrecht, J.

    2010-03-01

    There is a dearth of information on dust emissions from sources that are unique to U.S. Department of Defense testing and training activities. Dust emissions of PM 10 and PM 2.5 from low-level rotary-winged aircraft travelling (rotor-blade ≈7 m above ground level) over two types of desert surfaces (i.e., relatively undisturbed desert pavement and disturbed desert soil surface) were characterized at the Yuma Proving Ground (Yuma, AZ) in May 2007. Fugitive emissions are created by the shear stress of the outflow of high speed air created by the rotor-blade. The strength of the emissions was observed to scale primarily as a function of forward travel speed of the aircraft. Speed affects dust emissions in two ways: 1) as speed increases, peak shear stress at the soil surface was observed to decline proportionally, and 2) as the helicopter's forward speed increases its residence time over any location on the surface diminishes, so the time the downward rotor-generated flow is acting upon that surface must also decrease. The state of the surface over which the travel occurs also affects the scale of the emissions. The disturbed desert test surface produced approximately an order of magnitude greater emission than the undisturbed surface. Based on the measured emission rates for the test aircraft and the established scaling relationships, a rotary-winged aircraft similar to the test aircraft traveling 30 km h -1 over the disturbed surface would need to travel 4 km to produce emissions equivalent to one kilometer of travel by a light wheeled military vehicle also traveling at 30 km h -1 on an unpaved road. As rotary-winged aircraft activity is substantially less than that of off-road vehicle military testing and training activities it is likely that this source is small compared to emissions created by ground-based vehicle movements.

  9. Visually assessing the level of development and soil surface stability of cyanobacterially dominated biological soil crusts

    Science.gov (United States)

    Belnap, J.; Phillips, S.L.; Witwicki, D.L.; Miller, M.E.

    2008-01-01

    Biological soil crusts (BSCs) are an integral part of dryland ecosystems and often included in long-term ecological monitoring programs. Estimating moss and lichen cover is fairly easy and non-destructive, but documenting cyanobacterial level of development (LOD) is more difficult. It requires sample collection for laboratory analysis, which causes soil surface disturbance. Assessing soil surface stability also requires surface disturbance. Here we present a visual technique to assess cyanobacterial LOD and soil surface stability. We define six development levels of cyanobacterially dominated soils based on soil surface darkness. We sampled chlorophyll a concentrations (the most common way of assessing cyanobacterial biomass), exopolysaccharide concentrations, and soil surface aggregate stability from representative areas of each LOD class. We found that, in the laboratory and field, LOD classes were effective at predicting chlorophyll a soil concentrations (R2=68-81%), exopolysaccharide concentrations (R2=71%), and soil aggregate stability (R2=77%). We took representative photos of these classes to construct a field guide. We then tested the ability of field crews to distinguish these classes and found this technique was highly repeatable among observers. We also discuss how to adjust this index for the different types of BSCs found in various dryland regions.

  10. Low-Cost Dielectric Reflective Surface for Low-Level Backscattered Diffuse Reflections

    Science.gov (United States)

    Al-Nuaimi, Mustafa K. Taher; Hong, Wei; Gao, Xiqi

    2017-02-01

    This article presents the design of non-subwavelength, non-resonant, and non-absorptive dielectric surface that creates a low-level backward diffuse reflections under illumination of a far-field plane wave at millimeter wave regime. Thus, radar cross section reduction of a solid metallic object can be achieved. The dielectric surface is consist of unit cells of only two different electric permittivity ( ɛ r1 = 6.14 and ɛ r2 = 3.49) distributed across the surface aperture to achieve low-level backscattered diffuse reflections. The unit cells used are having non-subwavelength size (0.53λ80GHz) which ensures an easier fabrication of the presented surface using low cost simple PCB technology, in particular at high frequencies. RCS reduction of more than 10 dBsm is achieved from 70 to 87 GHz (BW ≈ 21.65 %) using the presented dielectric surface of optimized permittivity distribution. The RCS reduction capabilities of the presented surface are studied theoretically under both normal and oblique incidences and then fabricated and verified experimentally by reflectivity measurements.

  11. Fusion of multi-sensory NDT data for reliable detection of surface cracks: Signal-level vs. decision-level

    Science.gov (United States)

    Heideklang, René; Shokouhi, Parisa

    2016-02-01

    We present and compare two different approaches for NDT multi-sensor data fusion at signal (low) and decision (high) levels. Signal-level fusion is achieved by applying simple algebraic rules to strategically post-processed images. This is done in the original domain or in the domain of a suitable signal transform. The importance of signal normalization for low-level fusion applications is emphasized in regard to heterogeneous NDT data sets. For fusion at decision level, we develop a procedure based on assembling joint kernel density estimation (KDE). The procedure involves calculating KDEs for individual sensor detections and aggregating them by applying certain combination rules. The underlying idea is that if the detections from more than one sensor fall spatially close to one another, they are likely to result from the presence of a defect. On the other hand, single-senor detections are more likely to be structural noise or false alarm indications. To this end, we design the KDE combination rules such that it prevents single-sensor domination and allows data-driven scaling to account for the influence of individual sensors. We apply both fusion rules to a three-sensor dataset consisting in ET, MFL/GMR and TT data collected on a specimen with built-in surface discontinuities. The performance of the fusion rules in defect detection is quantitatively evaluated and compared against those of the individual sensors. Both classes of data fusion rules result in a fused image of fewer false alarms and thus improved defect detection. Finally, we discuss the advantages and disadvantages of low-level and high-level NDT data fusion with reference to our experimental results.

  12. Large-scale synthesis of palladium concave nanocubes with high-index facets for sustainable enhanced catalytic performance.

    Science.gov (United States)

    Xie, Xiaobin; Gao, Guanhui; Pan, Zhengyin; Wang, Tingjun; Meng, Xiaoqing; Cai, Lintao

    2015-02-17

    The catalytic activity of palladium (Pd) nanostructures highly relies on their size and morphology, especially enclosed with high-index facets, which provide more active sites so as to enhance their catalytic performance comparing with their low-index facet counterparts. Herein, Pd concave nanocubes enclosed with {730} facets by a one-pot scalable liquid method, with various high-index facets are synthesized via tuning reduction kinetics. Due to their high-index facets, the Pd concave nanocubes exhibit much higher electrocatalytic activity and stability for methanol oxidation than the Pd nanocubes enclosed by {100} facets and commercial Pd/C. Furthermore, we scale up synthesis of Pd concave nanocubes by expanding the volume of all species to fifty times with high-yield production.

  13. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    Science.gov (United States)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  14. Emotional responses during repeated sprint intervals performed on level, downhill and uphill surfaces.

    Science.gov (United States)

    Baron, Bertrand; Guilloux, Bertrand; Begue, Mylène; Uriac, Stéphane

    2015-01-01

    The purpose of this study was to test emotional responses during sprint intervals performed on a level, down and up surface. Fifty trained participants performed a maximal effort during a 60-m sprint and 10 repetitions of 60 m running sprints on a level, down and up surface on a 5.9% slope. Running speeds, emotional responses and heart rate were measured. Self-selected speeds were correlated with the rating of perceived exertion, the affective balance, the desire to stop and the resources needed for the task in all conditions whereas the pleasure, the desire to continue and the capacity to realise the task were correlated with speeds only during level and uphill running. Mean values of emotional parameters were significantly different (P < 0.05) during running on a flat surface, downhill and uphill. When the gradient of running surface is changed, the pattern of emotional responses was just translated, i.e. most of the slope between the evolution of emotional parameters and the repetitions were not significantly different whereas Y-intercepts were different. Consented effort is highly correlated with the resources needed for the task (P < 0.001, r(2) = 0.72). We propose that the difference in the resources needed for the task between level, downhill and uphill running (F 2, 1499 = 166.5, P < 0.001, Eta(2) = 0.18) is the most important key that explains our results.

  15. Deep layer-resolved core-level shifts in the beryllium surface

    DEFF Research Database (Denmark)

    Aldén, Magnus; Skriver, Hans Lomholt; Johansson, Börje

    1993-01-01

    Core-level energy shifts for the beryllium surface region are calculated by means of a Green’s function technique within the tight-binding linear muffin-tin orbitals method. Both initial- and final-state effects in the core-ionization process are fully accounted for. Anomalously large energy shifts...

  16. Polarization-induced renormalization of molecular levels at metallic and semiconducting surfaces

    DEFF Research Database (Denmark)

    García Lastra, Juan Maria; Rostgaard, Carsten; Rubio, A.

    2009-01-01

    On the basis of first-principles G0W0 calculations we systematically study how the electronic levels of a benzene molecule are renormalized by substrate polarization when physisorbed on different metallic and semiconducting surfaces. The polarization-induced reduction in the energy gap between...

  17. A new method for the determination of particulate contamination levels for surface cleanliness of fluid systems

    Science.gov (United States)

    1969-01-01

    Levels of contamination in fluid systems can be determined by a definition of a particle by a mathematical model, a method for calculating the tolerance limits of contamination, and an estimation of the probability that the contamination on the surface will migrate with the fluid in the system.

  18. Water level observations from Unmanned Aerial Vehicles for improving estimates of surface water-groundwater interaction

    DEFF Research Database (Denmark)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten

    2017-01-01

    . However, traditional river gauging stations are normally spaced too far apart to capture spatial patterns in the water surface, while spaceborne observations have limited spatial and temporal resolution. UAVs (Unmanned Aerial Vehicles) can retrieve river water level measurements, providing: i) high...

  19. Statistical analysis of global surface temperature and sea level using cointegration methods

    DEFF Research Database (Denmark)

    Schmidt, Torben; Johansen, Søren; Thejll, Peter

    2012-01-01

    Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to the lack of representation of ice-sheet dynamics in present-day physically-based climate models being unable to simulate observed sea level trends......, semi-empirical models have been applied as an alternative for projecting of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and land-ocean surface air...... temperature, capable of handling such peculiarities. We find a relationship between sea level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s...

  20. Microarray analysis of genes associated with cell surface NIS protein levels in breast cancer

    Directory of Open Access Journals (Sweden)

    Richardson Andrea L

    2011-10-01

    Full Text Available Abstract Background Na+/I- symporter (NIS-mediated iodide uptake allows radioiodine therapy for thyroid cancer. NIS is also expressed in breast tumors, raising potential for radionuclide therapy of breast cancer. However, NIS expression in most breast cancers is low and may not be sufficient for radionuclide therapy. We aimed to identify biomarkers associated with NIS expression such that mechanisms underlying NIS modulation in human breast tumors may be elucidated. Methods Published oligonucleotide microarray data within the National Center for Biotechnology Information Gene Expression Omnibus database were analyzed to identify gene expression tightly correlated with NIS mRNA level among human breast tumors. NIS immunostaining was performed in a tissue microarray composed of 28 human breast tumors which had corresponding oligonucleotide microarray data available for each tumor such that gene expression associated with cell surface NIS protein level could be identified. Results and Discussion NIS mRNA levels do not vary among breast tumors or when compared to normal breast tissues when detected by Affymetrix oligonucleotide microarray platforms. Cell surface NIS protein levels are much more variable than their corresponding NIS mRNA levels. Despite a limited number of breast tumors examined, our analysis identified cysteinyl-tRNA synthetase as a biomarker that is highly associated with cell surface NIS protein levels in the ER-positive breast cancer subtype. Conclusions Further investigation on genes associated with cell surface NIS protein levels within each breast cancer molecular subtype may lead to novel targets for selectively increasing NIS expression/function in a subset of breast cancers patients.

  1. Observational evidence of temperature trends at two levels in the surface layer

    Directory of Open Access Journals (Sweden)

    X. Lin

    2015-09-01

    Full Text Available Long-term surface air temperatures at 1.5 m screen level over land are used in calculating a global average surface temperature trend. This global trend is used by the IPCC and others to monitor, assess, and describe global warming or warming hiatus. Current knowledge of near-surface temperature trends with respect to height, however, is limited and inadequately understood because surface temperature observations at different heights in the surface layer in the world are rare especially from a high-quality and long-term climate monitoring network. Here we use high-quality two-height Oklahoma Mesonet observations, synchronized in time, fixed in height, and situated in relatively flat terrain, to assess temperature trends and differentiating temperature trends with respect to heights (i.e., near-surface lapse rate trend over the period 1997 to 2013. We show that the near-surface lapse rate has significantly decreased with a trend of −0.18 ± 0.03 °C (10 m−1 decade−1 indicating that the 9 m height temperatures increased faster than temperatures at the 1.5 m screen level and conditions at the 1.5 m height cooled faster than at the 9 m height. However, neither of the two individual height temperature trends by themselves were statistically significant. The magnitude of lapse rate trend is greatest under lighter winds at night. Nighttime lapse rate trends were significantly more negative than daytime lapse rate trends and the average lapse rate trend was three times more negative under calm conditions than under windy conditions. Our results provide the first observational evidence of near-surface temperature changes with respect to height that could enhance the assessment of climate model predictions.

  2. An Intelligent Response Surface Methodology for Modeling of Domain Level Constraints

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An effective modeling method of domain level constraints in the constraint network for concurrent engineering (CE) was developed. The domain level constraints were analyzed and the framework of modeling of domain level constraints based on simulation and approximate technology was given. An intelligent response surface methodology (IRSM) was proposed, in which artificial intelligence technologies are introduced into the optimization process. The design of crank and connecting rod in the V6 engine as example was given to show the validity of the modeling method.

  3. A design method based on photonic crystal theory for Bragg concave diffraction grating

    Science.gov (United States)

    Du, Bingzheng; Zhu, Jingping; Mao, Yuzheng; Li, Bao; Zhang, Yunyao; Hou, Xun

    2017-02-01

    A design method based on one-dimensional photonic crystal theory (1-D PC theory) is presented to design Bragg concave diffraction grating (Bragg-CDG) for the demultiplexer. With this design method, the reflection condition calculated by the 1-D PC theory can be matched perfectly with the diffraction condition. As a result, the shift of central wavelength of diffraction spectra can be improved, while keeping high diffraction efficiency. Performances of Bragg-CDG for TE and TM-mode are investigated, and the simulation results are consistent with the 1-D PC theory. This design method is expected to be applied to improve the accuracy and efficiency of Bragg-CDG after further research.

  4. One algorithm for branch and bound method for solving concave optimization problem

    Science.gov (United States)

    Andrianova, A. A.; Korepanova, A. A.; Halilova, I. F.

    2016-11-01

    The article describes the algorithm for branch and bound method for solving the concave programming problem, which is based on the idea of similarity the necessary and sufficient conditions of optimum for the original problem and for a convex programming problem with another feasible set and reverse the sign of the objective function. To find the feasible set of the equivalent convex programming problem we construct an algorithm using the idea of the branch and bound method. We formulate various branching techniques and discusses the construction of the lower objective function evaluations for the node of the decision tree. The article discusses the results of experiments of this algorithm for some famous test problems of a particular form.

  5. Concave soft sets, critical soft points, and union-soft ideals of ordered semigroups.

    Science.gov (United States)

    Jun, Young Bae; Song, Seok Zun; Muhiuddin, G

    2014-01-01

    The notions of union-soft semigroups, union-soft l-ideals, and union-soft r-ideals are introduced, and related properties are investigated. Characterizations of a union-soft semigroup, a union-soft l-ideal, and a union-soft r-ideal are provided. The concepts of union-soft products and union-soft semiprime soft sets are introduced, and their properties related to union-soft l-ideals and union-soft r-ideals are investigated. Using the notions of union-soft l-ideals and union-soft r-ideals, conditions for an ordered semigroup to be regular are considered. The concepts of concave soft sets and critical soft points are introduced, and their properties are discussed.

  6. Concave Soft Sets, Critical Soft Points, and Union-Soft Ideals of Ordered Semigroups

    Directory of Open Access Journals (Sweden)

    Young Bae Jun

    2014-01-01

    Full Text Available The notions of union-soft semigroups, union-soft l-ideals, and union-soft r-ideals are introduced, and related properties are investigated. Characterizations of a union-soft semigroup, a union-soft l-ideal, and a union-soft r-ideal are provided. The concepts of union-soft products and union-soft semiprime soft sets are introduced, and their properties related to union-soft l-ideals and union-soft r-ideals are investigated. Using the notions of union-soft l-ideals and union-soft r-ideals, conditions for an ordered semigroup to be regular are considered. The concepts of concave soft sets and critical soft points are introduced, and their properties are discussed.

  7. Aerosols attenuating the solar radiation collected by solar tower plants: The horizontal pathway at surface level

    Science.gov (United States)

    Elias, Thierry; Ramon, Didier; Dubus, Laurent; Bourdil, Charles; Cuevas-Agulló, Emilio; Zaidouni, Taoufik; Formenti, Paola

    2016-05-01

    Aerosols attenuate the solar radiation collected by solar tower plants (STP), along two pathways: 1) the atmospheric column pathway, between the top of the atmosphere and the heliostats, resulting in Direct Normal Irradiance (DNI) changes; 2) the grazing pathway close to surface level, between the heliostats and the optical receiver. The attenuation along the surface-level grazing pathway has been less studied than the aerosol impact on changes of DNI, while it becomes significant in STP of 100 MW or more. Indeed aerosols mostly lay within the surface atmospheric layer, called the boundary layer, and the attenuation increases with the distance covered by the solar radiation in the boundary layer. In STP of 100 MW or more, the distance between the heliostats and the optical receiver becomes large enough to produce a significant attenuation by aerosols. We used measured aerosol optical thickness and computed boundary layer height to estimate the attenuation of the solar radiation at surface level at Ouarzazate (Morocco). High variabilities in aerosol amount and in vertical layering generated a significant magnitude in the annual cycle and significant inter-annual changes. Indeed the annual mean of the attenuation caused by aerosols over a 1-km heliostat-receiver distance was 3.7% in 2013, and 5.4% in 2014 because of a longest desert dust season. The monthly minimum attenuation of less than 3% was observed in winter and the maximum of more than 7% was observed in summer.

  8. Surface shift of the occupied and unoccupied 4f levels of the rare-earth metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Johansson, Börje; Skriver, Hans Lomholt

    1995-01-01

    The surface energy shifts of the occupied and unoccupied 4f levels for the lanthanide metals have been calculated from first principles by means of a Green’s-function technique within the tight-binding linear muffin-tin orbitals method. We use the concept of complete screening to identify the occ...... played by the initial and the different final states of the core-excitation process, permitted by the fact that the so-called initial-state effect is identical upon 4f removal and 4f addition. Surface energy and work function calculations are also reported....

  9. Mapping Hydrophobicity on the Protein Molecular Surface at Atom-Level Resolution

    Science.gov (United States)

    Nicolau Jr., Dan V.; Paszek, Ewa; Fulga, Florin; Nicolau, Dan V.

    2014-01-01

    A precise representation of the spatial distribution of hydrophobicity, hydrophilicity and charges on the molecular surface of proteins is critical for the understanding of the interaction with small molecules and larger systems. The representation of hydrophobicity is rarely done at atom-level, as this property is generally assigned to residues. A new methodology for the derivation of atomic hydrophobicity from any amino acid-based hydrophobicity scale was used to derive 8 sets of atomic hydrophobicities, one of which was used to generate the molecular surfaces for 35 proteins with convex structures, 5 of which, i.e., lysozyme, ribonuclease, hemoglobin, albumin and IgG, have been analyzed in more detail. Sets of the molecular surfaces of the model proteins have been constructed using spherical probes with increasingly large radii, from 1.4 to 20 Å, followed by the quantification of (i) the surface hydrophobicity; (ii) their respective molecular surface areas, i.e., total, hydrophilic and hydrophobic area; and (iii) their relative densities, i.e., divided by the total molecular area; or specific densities, i.e., divided by property-specific area. Compared with the amino acid-based formalism, the atom-level description reveals molecular surfaces which (i) present an approximately two times more hydrophilic areas; with (ii) less extended, but between 2 to 5 times more intense hydrophilic patches; and (iii) 3 to 20 times more extended hydrophobic areas. The hydrophobic areas are also approximately 2 times more hydrophobicity-intense. This, more pronounced “leopard skin”-like, design of the protein molecular surface has been confirmed by comparing the results for a restricted set of homologous proteins, i.e., hemoglobins diverging by only one residue (Trp37). These results suggest that the representation of hydrophobicity on the protein molecular surfaces at atom-level resolution, coupled with the probing of the molecular surface at different geometric resolutions

  10. Principle and geomorphological applicability of summit level and base level technique using Aster Gdem satellite-derived data and the original software Baz

    Directory of Open Access Journals (Sweden)

    Akihisa Motoki

    2015-05-01

    Full Text Available This article presents principle and geomorphological applicability of summit level technique using Aster Gdem satellite-derived topographicdata. Summit level corresponds to thevirtualtopographic surface constituted bylocalhighest points, such as peaks and plateau tops, and reconstitutes palaeo-geomorphology before the drainage erosion. Summit level map is efficient for reconstitution of palaeo-surfaces and detection of active tectonic movement. Base level is thevirtualsurface composed oflocallowest points, as valley bottoms. The difference between summit level and base level is called relief amount. Thesevirtualmapsareconstructed by theoriginalsoftwareBaz. Themacroconcavity index, MCI, is calculated from summit level and relief amount maps. The volume-normalised three-dimensional concavity index, TCI, is calculated from hypsometric diagram. The massifs with high erosive resistance tend to have convex general form and low MCI and TCI. Those with low resistance have concave form and high MCI and TCI. The diagram of TCI vs. MCI permits to distinguish erosive characteristics of massifs according to their constituent rocks. The base level map for ocean bottom detects the basement tectonic uplift which occurred before the formation of the volcanic seamounts.

  11. Estimation of surface UV levels based on Meteor-3/TOMS ozone data

    Energy Technology Data Exchange (ETDEWEB)

    Borisov, Y.A. [Central Aerological Observatory, Moscow (Russian Federation); Geogdzhaev, I.V. [Moscow Inst. of Physics and Technology, Moscow (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Moscow (Russian Federation)

    1995-12-31

    The major consequence of ozone layer depletion for the environment is an increase of harmful ultraviolet (UV) radiation on the Earth surface and in the upper ocean. This implies the importance of environmental UV monitoring. Since the direct global monitoring is not currently possible, indirect estimations of surface UV levels may be used based on satellite ozone data (Madronich, S. 1992). Total Ozone Mapping Spectrometer (TOMS) on board the METEOR-3 satellite provided regular set of data for such estimates. During the time of its operation (August, 1991 - December, 1994) the instrument registered several ozone hole events over Antarctica, when ozone levels dropped by as much as 60 % from their unperturbed values. Probably even more alarming ozone depletions were observed over highly populated regions of middle latitudes of northern hemisphere. Radiative transfer modeling was used to convert METEOR-3/TOMS daily ozone values into regional and global maps of biologically active UV. Calculations demonstrate the effect on surface UV levels produced by ozone hole over Antarctica and ozone depletions over the territory of Russia (March, 1994). UV contour lines deviate from the normal appearance which is determined by growing southward solar elevation. UV contour lines are almost perpendicular to the ozone ones in the ozone depletions areas. The 30 % ozone depletion, over Siberia caused more than 30 % increase in noontime erythemal UV levels, which is equivalent to 10-15 degrees southward latitude displacement. Higher UV radiation increases were found in ozone hole over South America (October 1992) equivalent to about 20 degrees southward displacement

  12. Two Surface-Tension Formulations For The Level Set Interface-Tracking Method

    Energy Technology Data Exchange (ETDEWEB)

    Shepel, S.V.; Smith, B.L

    2005-03-01

    The paper describes a comparative study of two surface-tension models for the Level Set interface tracking method. In both models, the surface tension is represented as a body force, concentrated near the interface, but the technical implementation of the two options is different. The first is based on a traditional Level Set approach, in which the surface tension is distributed over a narrow band around the interface using a smoothed Delta function. In the second model, which is based on the integral form of the fluid-flow equations, the force is imposed only in those computational cells through which the interface passes. Both models have been incorporated into the Finite-Element/Finite-Volume Level Set method, previously implemented into the commercial Computational Fluid Dynamics (CFD) code CFX-4. A critical evaluation of the two models, undertaken in the context of four standard Level Set benchmark problems, shows that the first model, based on the smoothed Delta function approach, is the more general, and more robust, of the two. (author)

  13. Differential internalin A levels in biofilms of Listeria monocytogenes grown on different surfaces and nutrient conditions.

    Science.gov (United States)

    Gilmartin, Niamh; Gião, Maria S; Keevil, Charles W; O'Kennedy, Richard

    2016-02-16

    Listeria monoctyogenes is a foodborne pathogen containing the surface protein, internalin A (InlA). The expression of this protein permits the invasion of L. monocytogenes into intestinal epithelial cells expressing the receptor E-cadherin, thus crossing the intestinal barrier and resulting in listerosis. The main aim of this work was to investigate InlA levels in different L. monocytogenes strains in both planktonic and sessile states using an anti-InlA antibody. Biofilms were grown in high and low nutrient environments on glass, stainless steel and polytetrafluoroethylene (PTFE). This study demonstrated that InlA levels varied greatly between strains and serotypes of L. monocytogenes. However, the serotypes 1/2a, 1/2b and 4b, associated with the largest number of outbreaks of listerosis consistently showed the highest InlA levels, regardless of nutrient content or planktonic or sessile state. Differences in InlA levels were also observed in biofilms grown on different surfaces such as glass, stainless steel and PTFE, with a significant reduction in InlA levels observed in biofilms on PTFE. Interestingly, although a large number of the total cells observed in biofilms formed in tap-water were non-cultivable, the virulence factor, InlA, was expressed at levels between 78 and 85%, thus indicating that these cells may still be virulent. A greater understanding of the factors that affect the levels of InlA on the surface of L. monocytogenes, is essential in the appreciation of the role of InlA in the persistence of biofilms containing L. monocytogenes and their potential to cause food borne disease.

  14. Fabrication of a molecular-level multilayer film on organic polymer surfaces via chemical bonding assembly.

    Science.gov (United States)

    Zhao, Hongchi; Yang, Peng; Deng, Jianping; Liu, Lianying; Zhu, Jianwu; Sui, Yuan; Lu, Jiaoming; Yang, Wantai

    2007-02-13

    A fresh multilayer film was fabricated on a molecular level and successfully tethered to the surface of a hydroxylated organic substrate via chemical bonding assembly (CBA). Sulfate anion groups (SO4-) were preintroduced onto the surface of biaxially oriented polypropylene (BOPP) films via a reference method. Upon hydrolysis of the SO4- groups, hydroxyl groups (--OH) were formed that subsequently acted as initial reagents for a series of alternate reactions with terephthalyl chloride (TPC) and bisphenol A (BPA). A stable and well-defined multilayer film was thus fabricated via the CBA method. As a result of the nanoscale multilayer fresh film being abundant with reactive groups, it is believed that the film and its fabrication method should provide a fundamental platform for further surface functionalization and direct the design of advanced materials with desired properties.

  15. Exploring the core level shift origin of sulfur and thiolates on Pd(111) surfaces.

    Science.gov (United States)

    Salvarezza, Roberto Carlos; Carro, Pilar

    2015-10-01

    Thiol molecules on planar metal surfaces are widely used for building sensing and electronic devices and also as capping agents to protect and to control the size and shape of nanoparticles. In the case of Pd the thiol molecules exhibit a complex behavior because C-S bond scission is possible, resulting in a significant amount of co-adsorbed S. Therefore identification of these species on Pd is a key point for many applications, a task that is usually achieved by XPS. Here we show, from DFT calculations, that the core level shift (CLS) of the S 2p binding energy (BE) of thiol and sulfur on different thiol-Pd(111) surface models strongly depends on the adsorbed or subsurface state of sulfur atoms. Our results reflect the complexity of S 2p BE behavior and contribute to understanding and reanalyzing the experimental data of thiolated Pd surfaces.

  16. GHRSST Level 4 RTO Terra MODIS-AMSRE Day North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  17. GHRSST Level 4 RTO Aqua MODIS-AMSRE Night North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  18. GHRSST Level 4 RTO Terra MODIS-AMSRE Night North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  19. GHRSST Level 4 RTO Aqua MODIS-AMSRE Day North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  20. GHRSST Level 4 CMC0.2deg Global Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature (SST) analysis produced daily on an operational basis at the Canadian...

  1. GHRSST Level 4 REMO_OI_SST_5km Regional Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature (SST) analysis produced daily on an operational basis by the...

  2. GHRSST Level 4 ODYSSEA North-Western Europe Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  3. GHRSST Level 4 DMI_OI North Sea and Baltic Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  4. GHRSST Level 4 MW_IR_OI Global Foundation Sea Surface Temperature analysis (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.81 degree grid at Remote Sensing...

  5. GHRSST Level 4 MUR Global Foundation Sea Surface Temperature Analysis (v4.1) (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced as a retrospective dataset (four day latency) and...

  6. A level set based segmentation approach for point-sampled surfaces

    Institute of Scientific and Technical Information of China (English)

    MIAO Yong-wei; FENG Jie-qing; ZHENG Guo-xian; PENG Qun-sheng

    2007-01-01

    Segmenting a complex 3D surface model into some visually meaningful sub-parts is one of the fundamental problems in digital geometry processing. In this paper, a novel segmentation approach of point-sampled surfaces is proposed, which is based on the level set evolution scheme. To segment the model so as to align the patch boundaries with high curvature zones, the driven speed function for the zero level set inside narrow band is defined by the extended curvature field, which approaches zero speed as the propagating front approaches high curvature zone. The effectiveness of the proposed approach is demonstrated by our experimental results. Furthermore, two applications of model segmentation are illustrated, such as piecewise parameterization and local editing for point-sampled geometry.

  7. Higher-Order Level-Set Method and Its Application in Biomolecular Surfaces Construction

    Institute of Scientific and Technical Information of China (English)

    Chandrajit L. Bajaj; Guo-Liang Xu; Qin Zhang

    2008-01-01

    We present a general framework for a higher-order spline level-set (HLS) method and apply this to biomolecule surfaces construction. Starting from a first order energy functional, we obtain a general level set formulation of geometric partial differential equation, and provide an efficient approach to solving this partial differential equation using a C2 spline basis. We also present a fast cubic spline interpolation algorithm based on convolution and the Z-transform, which exploits the local relationship of interpolatory cubic spline coefficients with respect to given function data values. One example of our HLS method is demonstrated, which is the construction of biomolecule surfaces (an implicit salvation interface) with their individual atomic coordinates and solvated radii as prerequisites.

  8. The assessment of ultrasonic root surface debridement by determination of residual endotoxin levels.

    Science.gov (United States)

    Smart, G J; Wilson, M; Davies, E H; Kieser, J B

    1990-03-01

    Recent demonstrations of the superficial nature and ease of removal of root-surface-associated cytotoxic materials suggest that extensive root-surface instrumentation is not warranted clinically. This in vitro investigation determined the detoxifying effects of a conservative regime of ultrasonic root debridement, using the Limulus amoebocyte lysate assay for lipopolysaccharide (LPS) as an indication of the presence or absence of cytotoxic materials. 20 extracted periodontally-involved single-rooted teeth, with no clinically detectable calculus deposits, were debrided with a Cavitron TF-10 tip. Light pressure, resulting from a force application of approximately 50 g, lasting for 0.8 s/mm2 of root surface was used and complete overlapping instrumentation ensured. The finding of LPS levels of less than 2.5 ng per root in 19 out of 20 teeth after such debridement was comparable to LPS levels found on healthy, uninvolved control teeth, and thus endorses the growing belief that root surface cleanliness can be readily achieved.

  9. Spontaneous radiative decay of translational levels of an atom near a dielectric surface

    CERN Document Server

    Le Kien, F; Kien, Fam Le

    2006-01-01

    We study spontaneous radiative decay of translational levels of an atom in the vicinity of a semi-infinite dielectric. We systematically derive the microscopic dynamical equations for the spontaneous decay process. We calculate analytically and numerically the radiative linewidths and the spontaneous transition rates for the translational levels. The roles of the interference between the emitted and reflected fields and of the transmission into the evanescent modes are clearly identified. Our numerical calculations for the silica--cesium interaction show that the radiative linewidths of the bound excited levels with large enough but not too large vibrational quantum numbers are moderately enhanced by the emission into the evanescent modes and those for the deep bound levels are substantially reduced by the surface-induced red shift of the transition frequency.

  10. Iterative algorithm for reconstructing rotationally asymmetric surface deviation with pixel-level spatial resolution

    Science.gov (United States)

    Quan, Haiyang; Wu, Fan; Hou, Xi

    2015-10-01

    New method for reconstructing rotationally asymmetric surface deviation with pixel-level spatial resolution is proposed. It is based on basic iterative scheme and accelerates the Gauss-Seidel method by introducing an acceleration parameter. This modified Successive Over-relaxation (SOR) is effective for solving the rotationally asymmetric components with pixel-level spatial resolution, without the usage of a fitting procedure. Compared to the Jacobi and Gauss-Seidel method, the modified SOR method with an optimal relaxation factor converges much faster and saves more computational costs and memory space without reducing accuracy. It has been proved by real experimental results.

  11. Development, Characterization, and Optimization of Protein Level in Date Bars Using Response Surface Methodology

    OpenAIRE

    Muhammad Nadeem; Salim-ur-Rehman,; Faqir Muhammad Anjum; Mian Anjum Murtaza; Ghulam Mueen-ud-Din

    2012-01-01

    This project was designed to produce a nourishing date bar with commercial value especially for school going children to meet their body development requirements. Protein level of date bars was optimized using response surface methodology (RSM). Economical and underutilized sources, that is, whey protein concentrate and vetch protein isolates, were explored for protein supplementation. Fourteen date bar treatments were produced using a central composite design (CCD) with 2 variables and 3 lev...

  12. Variability of the Coupling Between Surface Air Temperature and Northern Annular Mode at Various Levels

    Institute of Scientific and Technical Information of China (English)

    TAN Benkui; SUO Lingling; HUANG Jiayou

    2008-01-01

    This article focuses on the variability of the coupling between surface air temperature(SAT)and northern annular mode(NAM)at various levels.To measure the coupling intensity between the SAT and the NAM anomaly fields.the coupling index has been defined as the leading principal component of the partial least squares regression model of the SAT and NAM anomalies.Both a composite analysis and the coupling index have been used to reveal level-by-level and month-to-month variability of the coupling between the upper anomalous NAM and the SAT in the Northern Hemisphere.The major results are as follows:the January SAT anomaly is more strongly coupled with the January NAM anomaly at the middle-upper tropospheric levels than that at the other levels,while the same is true for the February SAT anomaly with the January NAM anomaly at the lower stratospheric levels.The January NAM anomaly at the middleupper tropospheric levels is most strongly coupled with the January SAT anomaly,and the coupling intensity is successively reduced month by month and becomes trivial after April.The January NAM anomaly at the lower stratospheric levels is more strongly coupled with January,Febrnary and March SAT anomalies,but the coupling becomes trivial after April.

  13. Optimization of radiotherapy to target volumes with concave outlines: target-dose homogenization and selective sparing of critical structures by constrained matrix inversion

    Energy Technology Data Exchange (ETDEWEB)

    Colle, C.; Van den Berge, D.; De Wagter, C.; Fortan, L.; Van Duyse, B.; De Neve, W.

    1995-12-01

    The design of 3D-conformal dose distributions for targets with concave outlines is a technical challenge in conformal radiotherapy. For these targets, it is impossible to find beam incidences for which the target volume can be isolated from the tissues at risk. Commonly occurring examples are most thyroid cancers and the targets located at the lower neck and upper mediastinal levels related to some head and neck. A solution to this problem was developed, using beam intensity modulation executed with a multileaf collimator by applying a static beam-segmentation technique. The method includes the definition of beam incidences and beam segments of specific shape as well as the calculation of segment weights. Tests on Sherouse`s GRATISTM planning system allowed to escalate the dose to these targets to 65-70 Gy without exceeding spinal cord tolerance. Further optimization by constrained matrix inversion was investigated to explore the possibility of further dose escalation.

  14. A comparative study of the phosphate levels in some surface and ground water bodies of Swaziland

    Directory of Open Access Journals (Sweden)

    A.O. Fadiran

    2008-08-01

    Full Text Available The levels of total phosphate in selected surface water and groundwater bodies from Manzini and Lubombo regions of Swaziland were determined using UV spectroscopic method. Samples were collected from three rivers (upstream and downstream of each, three industrial effluents, one reservoir, one pond, one tap water and fifteen boreholes. Mean phosphate levels in the tap water and reservoir varied between 0.08-0.09 mg/L while for the river samples, the range was 0.11-0.37 and for the industrial discharge, it was 0.11-1.60 mg/L PO4–P. For the ground water systems it ranged between 0.10-0.49 mg/L PO4–P. The mean phosphate levels in all the analyzed surface and groundwater samples were below the recommended maximum contaminant level (MCL by SWSC (Swaziland Water Service Corporation – i.e. 1.0 mg/L for drinking water; 2.0 mg/L for rivers and industrial effluents, and the South African criterion of 1.0 mg/L PO4–P, for sewage effluents being discharged into receiving waters. However, pooled mean values for all the sites were higher than the USEPA criterion of 0.03 mg/L maximum for uncontaminated lakes. Dominant factors considered to have influenced the levels of phosphates in both the surface and groundwater samples analyzed include industrial activities (where present, agricultural activities (including livestock, population density, location (urban, suburban or rural, soil/rock type in the vicinity of the sampling point, climate and rainfall pattern of the area or region concerned.

  15. Potential energy surface and rovibrational energy levels of the H2-CS van der Waals complex.

    Science.gov (United States)

    Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe; Dubernet, Marie-Lise; Marinakis, Sarantos

    2012-12-21

    Owing to its large dipole, astrophysicists use carbon monosulfide (CS) as a tracer of molecular gas in the interstellar medium, often in regions where H(2) is the most abundant collider. Predictions of the rovibrational energy levels of the weakly bound complex CS-H(2) (not yet observed) and also of rate coefficients for rotational transitions of CS in collision with H(2) should help to interpret the observed spectra. This paper deals with the first goal, i.e., the calculation of the rovibrational energy levels. A new four-dimensional intermolecular potential energy surface for the H(2)-CS complex is presented. Ab initio potential energy calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and midbond functions. The potential energy surface was obtained by an analytic fit of the ab initio data. The equilibrium structure of the H(2)-CS complex is found to be linear with the carbon pointing toward H(2) at the intermolecular separation of 8.6 a(o). The corresponding well depth is -173 cm(-1). The potential was used to calculate the rovibrational energy levels of the para-H(2)-CS and ortho-H(2)-CS complexes. The present work provides the first theoretical predictions of these levels. The calculated dissociation energies are found to be 35.9 cm(-1) and 49.9 cm(-1), respectively, for the para and ortho complexes. The second virial coefficient for the H(2)-CS pair has also been calculated for a large range of temperature. These results could be used to assign future experimental spectra and to check the accuracy of the potential energy surface.

  16. Core levels, valence band structure and unoccupied states of clean InN surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Himmerlich, Marcel; Eisenhardt, Anja; Schaefer, Juergen A.; Krischok, Stefan [Institut fuer Physik and Institut fuer Mikro- und Nanotechnologien, TU Ilmenau (Germany)

    2008-07-01

    In this study we used a surface analytics system directly connected to a MBE growth module to study the surface properties of thin InN films. The samples were prepared by plasma assisted molecular beam epitaxy on GaN/Al{sub 2}O{sub 3}(0001) templates and exhibited a 2 x 2 reconstruction after growth. The prepared samples were analysed by photoelectron spectroscopy as well as electron energy loss spectroscopy (EELS). For the occupied states, a very good agreement to available theoretical calculations is found. Although, the valence band maximum is located at 1.6 eV, indicating strong downward band bending of {proportional_to}0.9 eV, photoemission is detected up to E{sub F}. This indicates that the Fermi level is pinned above the conduction band minimum, as recently predicted. The spin-orbit splitting of the In 4d level at 17.8 eV could be resolved using He II radiation. Furthermore, from the fine structure of the secondary electron cascade peak we extract the energy of different unoccupied states 0 eV to 9 eV above the vacuum level. These measurements enable us to identify features in the InN EELS spectra, with a loss energy larger than 16 eV, as interband transitions from the In 4d level.

  17. Development, Characterization, and Optimization of Protein Level in Date Bars Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem

    2012-01-01

    Full Text Available This project was designed to produce a nourishing date bar with commercial value especially for school going children to meet their body development requirements. Protein level of date bars was optimized using response surface methodology (RSM. Economical and underutilized sources, that is, whey protein concentrate and vetch protein isolates, were explored for protein supplementation. Fourteen date bar treatments were produced using a central composite design (CCD with 2 variables and 3 levels for each variable. Date bars were then analyzed for nutritional profile. Proximate composition revealed that addition of whey protein concentrate and vetch protein isolates improved the nutritional profile of date bars. Protein level, texture, and taste were considerably improved by incorporating 6.05% whey protein concentrate and 4.35% vetch protein isolates in date bar without affecting any sensory characteristics during storage. Response surface methodology was observed as an economical and effective tool to optimize the ingredient level and to discriminate the interactive effects of independent variables.

  18. Influence of reconstruction water-bearing levels on surface displacement of post-mining areas

    Science.gov (United States)

    Milczarek, Wojciech; Blachowski, Jan; Grzempowski, Piotr

    2014-05-01

    The phenomenon of secondary deformation characteristic of the post-mining areas is not sufficiently recognized. For ground surfaces phenomenon may be continuous or discontinuous. There is no sufficient information that describes behavior of the rock mass in the long term after end of exploitation. It is considered that this phenomenon is gradually disappears with end of exploitation. Reliable quantitative data comes only from the analysis of direct measurements in selected areas: geodetic and satellites measurements. Analyzing current situation of operating mines can be said that in the near years, more centers will limit the mining of coal mining. This will contribute to separation further of post-mining areas, in which will be required to maintaining a permanent monitoring and making predictions on the impact of ended exploitation of the rock mass surface. This will be particularly important for highly urbanized areas. This study used finite element method (FEM) to describe phenomenon of reconstruction water-bearing levels and its impact on displacement on the ground surface. It was assumed that significant factors that influence the occurrence and size of secondary deformations are: reconstruction of water-bearing levels in the prior drainer rock mass, size of past exploitation, spatial distribution of coal seams and geological and tectonic structure has been assumed. The transversally isotropic model of six elastic constants: E1 = E2, E3, ν = ν12, ν13, G12, G13 has been assumed to describe of rock mass in the numerical calculations. Geometrical models used in the numerical calculations have been developed using GIS tools. For the study two-dimensional and three-dimensional models characterized by different geological conditions and different configuration of mining data have been developed. The results obtained displacements of the ground surface for the period of mining activity has been verified with the results based on the Knothe theory. The results of

  19. Exceptionally crystalline and conducting acid doped polyaniline films by level surface assisted solution casting approach

    Energy Technology Data Exchange (ETDEWEB)

    Puthirath, Anand B.; Varma, Sreekanth J.; Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Cochin, Kerala 682022 (India); Methattel Raman, Shijeesh [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Cochin, Kerala 682022 (India)

    2016-04-18

    Emeraldine salt form of polyaniline (PANI) was synthesized by chemical oxidative polymerisation method using ammonium persulfate as oxidant. Resultant emeraldine salt form of PANI was dedoped using ammonia solution and then re-doped with camphor sulphonic acid (CSA), naphthaline sulphonic acid (NSA), hydrochloric acid (HCl), and m-cresol. Thin films of these doped PANI samples were deposited on glass substrates using solution casting method with m-cresol as solvent. A level surface was employed to get homogeneous thin films of uniform thickness. Detailed X-ray diffraction studies have shown that the films are exceptionally crystalline. The crystalline peaks observed in the XRD spectra can be indexed to simple monoclinic structure. FTIR and Raman spectroscopy studies provide convincing explanation for the exceptional crystallinity observed in these polymer films. FESEM and AFM images give better details of surface morphology of doped PANI films. The DC electrical conductivity of the samples was measured using four point probe technique. It is seen that the samples also exhibit quite high DC electrical conductivity, about 287 S/cm for CSA doped PANI, 67 S/cm for NSA doped PANI 65 S/cm for HCl doped PANI, and just below 1 S/cm for m-cresol doped PANI. Effect of using the level surface for solution casting is studied and correlated with the observed crystallinity.

  20. Exceptionally crystalline and conducting acid doped polyaniline films by level surface assisted solution casting approach

    Science.gov (United States)

    Puthirath, Anand B.; Methattel Raman, Shijeesh; Varma, Sreekanth J.; Jayalekshmi, S.

    2016-04-01

    Emeraldine salt form of polyaniline (PANI) was synthesized by chemical oxidative polymerisation method using ammonium persulfate as oxidant. Resultant emeraldine salt form of PANI was dedoped using ammonia solution and then re-doped with camphor sulphonic acid (CSA), naphthaline sulphonic acid (NSA), hydrochloric acid (HCl), and m-cresol. Thin films of these doped PANI samples were deposited on glass substrates using solution casting method with m-cresol as solvent. A level surface was employed to get homogeneous thin films of uniform thickness. Detailed X-ray diffraction studies have shown that the films are exceptionally crystalline. The crystalline peaks observed in the XRD spectra can be indexed to simple monoclinic structure. FTIR and Raman spectroscopy studies provide convincing explanation for the exceptional crystallinity observed in these polymer films. FESEM and AFM images give better details of surface morphology of doped PANI films. The DC electrical conductivity of the samples was measured using four point probe technique. It is seen that the samples also exhibit quite high DC electrical conductivity, about 287 S/cm for CSA doped PANI, 67 S/cm for NSA doped PANI 65 S/cm for HCl doped PANI, and just below 1 S/cm for m-cresol doped PANI. Effect of using the level surface for solution casting is studied and correlated with the observed crystallinity.

  1. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. I. Argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Culver, Cody [Materials Science Program, University of Wisconsin, Madison, WI 53706 (United States); Wang, Shicong; Wendt, Amy E. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI 53706 (United States); Radovanov, Svetlana; Persing, Harold [Varian Semiconductor Equipment, Applied Materials Inc., Gloucester, MA 01939 (United States)

    2014-03-15

    Vacuum ultraviolet (VUV) photons emitted from excited atomic states are ubiquitous in material processing plasmas. The highly energetic photons can induce surface damage by driving surface reactions, disordering surface regions, and affecting bonds in the bulk material. In argon plasmas, the VUV emissions are due to the decay of the 1s{sub 4} and 1s{sub 2} principal resonance levels with emission wavelengths of 104.8 and 106.7 nm, respectively. The authors have measured the number densities of atoms in the two resonance levels using both white light optical absorption spectroscopy and radiation-trapping induced changes in the 3p{sup 5}4p→3p{sup 5}4s branching fractions measured via visible/near-infrared optical emission spectroscopy in an argon inductively coupled plasma as a function of both pressure and power. An emission model that takes into account radiation trapping was used to calculate the VUV emission rate. The model results were compared to experimental measurements made with a National Institute of Standards and Technology-calibrated VUV photodiode. The photodiode and model results are in generally good accord and reveal a strong dependence on the neutral gas temperature.

  2. Reduction of Fermi level pinning and recombination at polycrystalline CdTe surfaces by laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Simonds, Brian J. [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Kheraj, Vipul [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Applied Physics, S. V. National Institute of Technology, Surat 395 007 (India); Palekis, Vasilios; Ferekides, Christos [Electrical Engineering, University of South Florida, Tampa, Florida 33620 (United States); Scarpulla, Michael A., E-mail: scarpulla@eng.utah.edu [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

    2015-06-14

    Laser processing of polycrystalline CdTe is a promising approach that could potentially increase module manufacturing throughput while reducing capital expenditure costs. For these benefits to be realized, the basic effects of laser irradiation on CdTe must be ascertained. In this study, we utilize surface photovoltage spectroscopy (SPS) to investigate the changes to the electronic properties of the surface of polycrystalline CdTe solar cell stacks induced by continuous-wave laser annealing. The experimental data explained within a model consisting of two space charge regions, one at the CdTe/air interface and one at the CdTe/CdS junction, are used to interpret our SPS results. The frequency dependence and phase spectra of the SPS signal are also discussed. To support the SPS findings, low-temperature spectrally-resolved photoluminescence and time-resolved photoluminescence were also measured. The data show that a modest laser treatment of 250 W/cm{sup 2} with a dwell time of 20 s is sufficient to reduce the effects of Fermi level pinning at the surface due to surface defects.

  3. Surface elevation change and susceptibility of coastal wetlands to sea level rise in Liaohe Delta, China

    Science.gov (United States)

    Wang, Guo-dong; Wang, Ming; Lu, Xian-guo; Jiang, Ming

    2016-10-01

    The Liaohe Delta in China is an ecologically and commercially important wetland system under threat from sea level rise and marsh subsidence. Sediments deposited in coastal marshes could offer wetlands a potentially important means for adjusting surface elevation with rising sea level, yet coastal wetland stability in Liaohe Delta is not well understood due to limited data from long-term experiments. In this study, wetland surface elevation and vertical accretion were measured from 2011 to 2015 using a surface elevation table (SET) and feldspar marker horizons in two Phragmites and two Suaeda marshes receiving Liaohe River water. The analysis shows that the Phragmites marshes exhibited higher rates of marsh accretion and elevation change than the Suaeda marshes. The two Phragmites marsh sites had average surface elevation change rates at 8.8 and 9.3 mm yr-1, vertical accretion at 17.4 and 17.6 mm yr-1, and shallow subsidence at 8.6 and 8.3 mm yr-1. The average rates of elevation change, vertical accretion, and shallow subsidence at two Suaeda marsh sites were 5.8 and 6.3 mm yr-1, 13.6 and 14.8 mm yr-1, and 7.8 and 8.5 mm yr-1, respectively. The trends suggest that coastal marshes in Liaohe Delta are experiencing changes in average soil elevation that range from a net increase of 0.3 mm y-1 to 6.9 mm y-1 relative to averaged sea level rise in Bohai Sea reported by the 2016 State Oceanic Administration People's Republic of China projection (2.4-5.5 mm y-1), which indicated that the four wetland sites would adjust to the sea level rise and even continue to gain elevation, especially for the Phragmites sites. Nevertheless, the vulnerability of coastal wetlands in Liaohe Delta need further assessment considering the accelerated sea level rise, the high rate of subsidence, and the declining sediment delivery owing to anthropogenic activities such as dam constructions in the river basin.

  4. An ab initio potential energy surface and vibrational energy levels of HXeBr

    Institute of Scientific and Technical Information of China (English)

    Zheng Guo Huang; En Cui Yang; Dai Qian Xie

    2008-01-01

    A three-dimensional global potential energy surface for the electronic ground state of HXeBr molecule is constructed from morethan 4200 ab initio points. These points are generated using an internally contracted multi-reference configuration interactionmethod with the Davidson correction (icMRCI + Q) and large basis sets. The stabilities and dissociation barriers are identified fromthe potential energy surfaces. The three-body dissociation channel is found to be the dominate dissociation channel for HXeBr.Based on the obtained potentials, low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm is found tobe in good agreement with the available experimental band origins.2008 Zheng Guo Huang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  5. Design and fabrication of concave-convex lens for head mounted virtual reality 3D glasses

    Science.gov (United States)

    Deng, Zhaoyang; Cheng, Dewen; Hu, Yuan; Huang, Yifan; Wang, Yongtian

    2015-08-01

    As a kind of light-weighted and convenient tool to achieve stereoscopic vision, virtual reality glasses are gaining more popularity nowadays. For these glasses, molded plastic lenses are often adopted to handle both the imaging property and the cost of massive production. However, the as-built performance of the glass depends on both the optical design and the injection molding process, and maintaining the profile of the lens during injection molding process presents particular challenges. In this paper, optical design is combined with processing simulation analysis to obtain a design result suitable for injection molding. Based on the design and analysis results, different experiments are done using high-quality equipment to optimize the process parameters of injection molding. Finally, a single concave-convex lens is designed with a field-of-view of 90° for the virtual reality 3D glasses. The as-built profile error of the glass lens is controlled within 5μm, which indicates that the designed shape of the lens is fairly realized and the designed optical performance can thus be achieved.

  6. A proof of convergence of the concave-convex procedure using Zangwill's theory.

    Science.gov (United States)

    Sriperumbudur, Bharath K; Lanckriet, Gert R G

    2012-06-01

    The concave-convex procedure (CCCP) is an iterative algorithm that solves d.c. (difference of convex functions) programs as a sequence of convex programs. In machine learning, CCCP is extensively used in many learning algorithms, including sparse support vector machines (SVMs), transductive SVMs, and sparse principal component analysis. Though CCCP is widely used in many applications, its convergence behavior has not gotten a lot of specific attention. Yuille and Rangarajan analyzed its convergence in their original paper; however, we believe the analysis is not complete. The convergence of CCCP can be derived from the convergence of the d.c. algorithm (DCA), proposed in the global optimization literature to solve general d.c. programs, whose proof relies on d.c. duality. In this note, we follow a different reasoning and show how Zangwill's global convergence theory of iterative algorithms provides a natural framework to prove the convergence of CCCP. This underlines Zangwill's theory as a powerful and general framework to deal with the convergence issues of iterative algorithms, after also being used to prove the convergence of algorithms like expectation-maximization and generalized alternating minimization. In this note, we provide a rigorous analysis of the convergence of CCCP by addressing two questions: When does CCCP find a local minimum or a stationary point of the d.c. program under consideration? and when does the sequence generated by CCCP converge? We also present an open problem on the issue of local convergence of CCCP.

  7. Reliable single chip genotyping with semi-parametric log-concave mixtures.

    Directory of Open Access Journals (Sweden)

    Ralph C A Rippe

    Full Text Available The common approach to SNP genotyping is to use (model-based clustering per individual SNP, on a set of arrays. Genotyping all SNPs on a single array is much more attractive, in terms of flexibility, stability and applicability, when developing new chips. A new semi-parametric method, named SCALA, is proposed. It is based on a mixture model using semi-parametric log-concave densities. Instead of using the raw data, the mixture is fitted on a two-dimensional histogram, thereby making computation time almost independent of the number of SNPs. Furthermore, the algorithm is effective in low-MAF situations.Comparisons between SCALA and CRLMM on HapMap genotypes show very reliable calling of single arrays. Some heterozygous genotypes from HapMap are called homozygous by SCALA and to lesser extent by CRLMM too. Furthermore, HapMap's NoCalls (NN could be genotyped by SCALA, mostly with high probability. The software is available as R scripts from the website www.math.leidenuniv.nl/~rrippe.

  8. Waves and rays in plano-concave laser cavities: I. Geometric modes in the paraxial approximation

    Science.gov (United States)

    Barré, N.; Romanelli, M.; Lebental, M.; Brunel, M.

    2017-05-01

    Eigenmodes of laser cavities are studied theoretically and experimentally in two companion papers, with the aim of making connections between undulatory and geometric properties of light. In this first paper, we focus on macroscopic open-cavity lasers with localized gain. The model is based on the wave equation in the paraxial approximation; experiments are conducted with a simple diode-pumped Nd:YAG laser with a variable cavity length. After recalling fundamentals of laser beam optics, we consider plano-concave cavities with on-axis or off-axis pumping, with emphasis put on degenerate cavity lengths, where modes of different order resonate at the same frequency, and combine to form surprising transverse beam profiles. Degeneracy leads to the oscillation of so-called geometric modes whose properties can be understood, to a certain extent, also within a ray optics picture. We first provide a heuristic description of these modes, based on geometric reasoning, and then show more rigorously how to derive them analytically by building wave superpositions, within the framework of paraxial wave optics. The numerical methods, based on the Fox-Li approach, are described in detail. The experimental setup, including the imaging system, is also detailed and relatively simple to reproduce. The aim is to facilitate implementation of both the numerics and of the experiments, and to show that one can have access not only to the common higher-order modes but also to more exotic patterns.

  9. Comparison pesticide residue levels in the surface of Bertam River in Cameron Highlands, Pahang

    Energy Technology Data Exchange (ETDEWEB)

    Haron, S. H., E-mail: ismail@ukm.edu.my; Ismail, B. S., E-mail: sthumaira@yahoo.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600 UKM, Bangi, Selangor (Malaysia)

    2015-09-25

    The presence of pesticide residues in the surface water of Bertam River in the agricultural areas of Cameron Highlands in Pahang, Malaysia was monitored from May to October 2014. The sampling sites were located at 10 sampling points along the Bertam River in the vegetable planting areas. The extraction method of the pesticide (organophosphate/pyrethroid) from the river samples used solid phase extraction followed by gas chromatography (with electron capture detector, ECD). Insecticides, cypermethrin and chlorpyrifos were found in the surface water of Bertam River. High level concentrations of those insecticides in the river were observed during the period from May to October 2014, a period which included both seasons (wet and dry seasons). The highest concentration of 2.66 µg/mL and 1.23 µg/mL of cypermethrin was observed during the wet and dry seasons respectively. This could be due to the frequent usage of the above-mentioned insecticides coupled with contamination that could have originated from the application sites. Meanwhile, the lowest concentration detected in the surface water was chlorpyrifos (0.11 µg/mL and 0.17 µg/mL) during the dry and wet seasons, respectively.

  10. Comparison pesticide residue levels in the surface of Bertam River in Cameron Highlands, Pahang

    Science.gov (United States)

    Haron, S. H.; Ismail B., S.

    2015-09-01

    The presence of pesticide residues in the surface water of Bertam River in the agricultural areas of Cameron Highlands in Pahang, Malaysia was monitored from May to October 2014. The sampling sites were located at 10 sampling points along the Bertam River in the vegetable planting areas. The extraction method of the pesticide (organophosphate/pyrethroid) from the river samples used solid phase extraction followed by gas chromatography (with electron capture detector, ECD). Insecticides, cypermethrin and chlorpyrifos were found in the surface water of Bertam River. High level concentrations of those insecticides in the river were observed during the period from May to October 2014, a period which included both seasons (wet and dry seasons). The highest concentration of 2.66 µg/mL and 1.23 µg/mL of cypermethrin was observed during the wet and dry seasons respectively. This could be due to the frequent usage of the above-mentioned insecticides coupled with contamination that could have originated from the application sites. Meanwhile, the lowest concentration detected in the surface water was chlorpyrifos (0.11 µg/mL and 0.17 µg/mL) during the dry and wet seasons, respectively.

  11. Half-filled Landau level, topological insulator surfaces, and three-dimensional quantum spin liquids

    Science.gov (United States)

    Wang, Chong; Senthil, T.

    2016-02-01

    We synthesize and partly review recent developments relating the physics of the half-filled Landau level in two dimensions to correlated surface states of topological insulators in three dimensions. The latter are in turn related to the physics of certain three-dimensional quantum spin liquid states. The resulting insights provide an interesting answer to the old question of how particle-hole symmetry is realized in composite fermion liquids. Specifically the metallic state at filling ν =1/2 —described originally in pioneering work by Halperin, Lee, and Read as a liquid of composite fermions—was proposed recently by Son to be described by a particle-hole symmetric effective field theory distinct from that in the prior literature. We show how the relation to topological insulator surface states leads to a physical understanding of the correctness of this proposal. We develop a simple picture of the particle-hole symmetric composite fermion through a modification of older pictures as electrically neutral "dipolar" particles. We revisit the phenomenology of composite fermi liquids (with or without particle-hole symmetry), and show that their heat/electrical transport dramatically violates the conventional Wiedemann-Franz law but satisfies a modified one. We also discuss the implications of these insights for finding physical realizations of correlated topological insulator surfaces.

  12. Formation of Triboelectric Series via Atomic-Level Surface Functionalization for Triboelectric Energy Harvesting.

    Science.gov (United States)

    Shin, Sung-Ho; Bae, Young Eun; Moon, Hyun Kyung; Kim, Jungkil; Choi, Suk-Ho; Kim, Yongho; Yoon, Hyo Jae; Lee, Min Hyung; Nah, Junghyo

    2017-06-27

    Triboelectric charging involves frictional contact of two different materials, and their contact electrification usually relies on polarity difference in the triboelectric series. This limits the choices of materials for triboelectric contact pairs, hindering research and development of energy harvest devices utilizing triboelectric effect. A progressive approach to resolve this issue involves modification of chemical structures of materials for effectively engineering their triboelectric properties. Here, we describe a facile method to change triboelectric property of a polymeric surface via atomic-level chemical functionalizations using a series of halogens and amines, which allows a wide spectrum of triboelectric series over single material. Using this method, tunable triboelectric output power density is demonstrated in triboelectric generators. Furthermore, molecular-scale calculation using density functional theory unveils that electrons transferred through electrification are occupying the PET group rather than the surface functional group. The work introduced here would open the ability to tune triboelectric property of materials by chemical modification of surface and facilitate the development of energy harvesting devices and sensors exploiting triboelectric effect.

  13. Preferences of lame cows for type of surface and level of social contact in hospital pens

    DEFF Research Database (Denmark)

    Jensen, Margit Bak; Herskin, Mette S; Thomsen, Peter T.

    2015-01-01

    in a neighboring pen. These results suggest that provision of a deep-bedded lying area in hospital pens is important to the welfare of lame cows. We found no evidence of isolation-seeking behavior in animals with these diagnoses (and no systemic symptoms) while they were kept in individual hospital pens.......To investigate preferences of lame cows for flooring and level of social contact, 37 lame, lactating dairy cows (diagnosed with sole ulcer or white line disease) were housed individually for 6 d in experimental hospital pens, where they could choose between 2 equally sized areas (6m × 4.5m......) with either deep-bedded sand or a rubber surface. On both surfaces, cows could choose between 2 equally sized areas either near or away from heifers in a neighboring group pen. Cows spent more time lying on the deep-bedded sand than on the rubber surface (870 vs. 71min/d), whereas they spent less time upright...

  14. Fabrication of Surface Level Cu/SiCp Nanocomposites by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Cartigueyen Srinivasan

    2015-01-01

    Full Text Available Friction stir processing (FSP technique has been successfully employed as low energy consumption route to prepare copper based surface level nanocomposites reinforced with nanosized silicon carbide particles (SiCp. The effect of FSP parameters such as tool rotational speed, processing speed, and tool tilt angle on microstructure and microhardness was investigated. Single pass FSP was performed based on Box-Behnken design at three factors in three levels. A cluster of blind holes 2 mm in diameter and 3 mm in depth was used as particulate deposition technique in order to reduce the agglomeration problem during composite fabrication. K-type thermocouples were used to measure temperature histories during FSP. The results suggest that the heat generation during FSP plays a significant role in deciding the microstructure and microhardness of the surface composites. Microstructural observations revealed a uniform dispersion of nanosized SiCp without any agglomeration problem and well bonded with copper matrix at different process parameter combinations. X-ray diffraction study shows that no intermetallic compound was produced after processing. The microhardness of nanocomposites was remarkably enhanced and about 95% more than that of copper matrix.

  15. Reduction Expansion Synthesis as Strategy to Control Nitrogen Doping Level and Surface Area in Graphene

    Directory of Open Access Journals (Sweden)

    Russell Canty

    2015-10-01

    Full Text Available Graphene sheets doped with nitrogen were produced by the reduction-expansion (RES method utilizing graphite oxide (GO and urea as precursor materials. The simultaneous graphene generation and nitrogen insertion reactions are based on the fact that urea decomposes upon heating to release reducing gases. The volatile byproducts perform two primary functions: (i promoting the reduction of the GO and (ii providing the nitrogen to be inserted in situ as the graphene structure is created. Samples with diverse urea/GO mass ratios were treated at 800 °C in inert atmosphere to generate graphene with diverse microstructural characteristics and levels of nitrogen doping. Scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to study the microstructural features of the products. The effects of doping on the samples structure and surface area were studied by X-ray diffraction (XRD, Raman Spectroscopy, and Brunauer Emmet Teller (BET. The GO and urea decomposition-reduction process as well as nitrogen-doped graphene stability were studied by thermogravimetric analysis (TGA coupled with mass spectroscopy (MS analysis of the evolved gases. Results show that the proposed method offers a high level of control over the amount of nitrogen inserted in the graphene and may be used alternatively to control its surface area. To demonstrate the practical relevance of these findings, as-produced samples were used as electrodes in supercapacitor and battery devices and compared with conventional, thermally exfoliated graphene.

  16. Measurements of Location-Dependent Nitric Oxide Levels on Skin Surface in relation to Acupuncture Point.

    Science.gov (United States)

    Ha, Yejin; Kim, Misun; Nah, Jiseon; Suh, Minah; Lee, Youngmi

    2012-01-01

    Location-dependent skin surface's partial nitric oxide pressure (pNO) is studied using highly sensitive amperometric NO microsensor with a small sensing area (diameter  = 76 μm). The pNO level of LI4 (Hegu) acupuncture point is measured and compared with the pNO level of nonacupuncture point. In addition, the mapping of pNO is carried out over the left wrist skin area one- as well as two-dimensionally. Statistically higher pNO levels near the position of acupuncture points than non-acupuncture points are observed consistently, implying tight relationship between the level of NO release of skin and acupuncture points. The amperometric planar NO microsensor successfully monitors the heterogeneity of skin pNO distribution in high spatial resolution due to its advantageous features such as high sensitivity and small sensing dimension. The current study suggests the direct connection between NO and acupuncture points and possibly provides beneficial information to understand physiological roles and basis of the acupuncture points.

  17. PHOTOMETRIC STEREO SHAPE-AND-ALBEDO-FROM-SHADING FOR PIXEL-LEVEL RESOLUTION LUNAR SURFACE RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    W. C. Liu

    2017-07-01

    Full Text Available Shape and Albedo from Shading (SAfS techniques recover pixel-wise surface details based on the relationship between terrain slopes, illumination and imaging geometry, and the energy response (i.e., image intensity captured by the sensing system. Multiple images with different illumination geometries (i.e., photometric stereo can provide better SAfS surface reconstruction due to the increase in observations. Photometric stereo SAfS is suitable for detailed surface reconstruction of the Moon and other extra-terrestrial bodies due to the availability of photometric stereo and the less complex surface reflecting properties (i.e., albedo of the target bodies as compared to the Earth. Considering only one photometric stereo pair (i.e., two images, pixel-variant albedo is still a major obstacle to satisfactory reconstruction and it needs to be regulated by the SAfS algorithm. The illumination directional difference between the two images also becomes an important factor affecting the reconstruction quality. This paper presents a photometric stereo SAfS algorithm for pixel-level resolution lunar surface reconstruction. The algorithm includes a hierarchical optimization architecture for handling pixel-variant albedo and improving performance. With the use of Lunar Reconnaissance Orbiter Camera - Narrow Angle Camera (LROC NAC photometric stereo images, the reconstructed topography (i.e., the DEM is compared with the DEM produced independently by photogrammetric methods. This paper also addresses the effect of illumination directional difference in between one photometric stereo pair on the reconstruction quality of the proposed algorithm by both mathematical and experimental analysis. In this case, LROC NAC images under multiple illumination directions are utilized by the proposed algorithm for experimental comparison. The mathematical derivation suggests an illumination azimuthal difference of 90 degrees between two images is recommended to achieve

  18. Automatic choroid cells segmentation and counting based on approximate convexity and concavity of chain code in fluorescence microscopic image

    Science.gov (United States)

    Lu, Weihua; Chen, Xinjian; Zhu, Weifang; Yang, Lei; Cao, Zhaoyuan; Chen, Haoyu

    2015-03-01

    In this paper, we proposed a method based on the Freeman chain code to segment and count rhesus choroid-retinal vascular endothelial cells (RF/6A) automatically for fluorescence microscopy images. The proposed method consists of four main steps. First, a threshold filter and morphological transform were applied to reduce the noise. Second, the boundary information was used to generate the Freeman chain codes. Third, the concave points were found based on the relationship between the difference of the chain code and the curvature. Finally, cells segmentation and counting were completed based on the characteristics of the number of the concave points, the area and shape of the cells. The proposed method was tested on 100 fluorescence microscopic cell images, and the average true positive rate (TPR) is 98.13% and the average false positive rate (FPR) is 4.47%, respectively. The preliminary results showed the feasibility and efficiency of the proposed method.

  19. WEIGHTED KOPPELMAN-LERAY-NORGUET FORMULAS ON A LOCAL q-CONCAVE WEDGE IN A COMPLEX MANIFOLD

    Institute of Scientific and Technical Information of China (English)

    邱春晖; 姚宗元

    2003-01-01

    A weighted Koppelman-Leray-Norguet formula of (r, s) differential forms ona local q-concave wedge in a complex manifold is obtained. By constructing the newweighted kernels, the authors give a new weighted Koppelman-Leray-Norguet formula with-out boundary integral of (r, s) differential forms, which is different from the classical one.The new weighted formula is especially suitable for the case of the local q-concave wedgewith a non-smooth boundary, so one can avoid complex estimates of boundary integralsand the density of integral may be not defined on the boundary but only in the domain.Moreover, the weighted integral formulas have much freedom in applications such as in theinterpolation of functions.

  20. Numerical Simulation on Process of Hydrostatic Extrusion for Tungsten Alloy through Concave Dies with Equal-strain Contour Lines

    Institute of Scientific and Technical Information of China (English)

    Zhaohui ZHANG; Fuchi WANG

    2001-01-01

    The numerical simulation to the process of hydrostatic extrusion for tungsten alloy through the concave dies with the equal-strain contour lines was carried out in this paper by the large deformation and elasto-plastic finite theory and ANSYS software. Both the pressure in the process of extrusion and the stress-strain distribution in the sample were analyzed, which founds a basis to the engineering application.

  1. Effect of hydroxyapatite surface morphology on cell adhesion.

    Science.gov (United States)

    Iwamoto, Takashi; Hieda, Yohki; Kogai, Yasumichi

    2016-12-01

    We obtained hydroxyapatite (HAp) materials as a block by mixing HAp nanoparticles and polymer, and then calcining the mixtures. The surface morphology of the HAp materials was tuned by varying heat treatment conditions. After calcining the mixtures at 1200 or 800°C for 4h, the surface morphology of the HAp materials was flat or convexo-concave, respectively. The flat surface morphology, which showed micrometer-ordered grain boundaries, was formed by the aggregation of HAp nanoparticles. On the other hand, the convexo-concave surface morphology resulted from the agglomeration of HAp nanoparticles after heat treatment at 800°C for 4h with nanometer-ordered particle size. We tested cell adhesion to HAp materials with flat or convexo-concave surface morphology and found that cells adhered well to the flat HAp materials but not to the convexo-concave HAp materials. This technique for selectively preparing HAp materials with flat or convexo-concave surface morphology was very easy because we merely mixed commercial HAp nanoparticles with polymer and then calcined the mixtures. As a result, the heat treatment temperature affected the surface morphology of our HAp materials, and their surface morphologies contributed to cell adhesion independently of other material properties.

  2. ANISOTROPY OF X-RAY BURSTS FROM NEUTRON STARS WITH CONCAVE ACCRETION DISKS

    Energy Technology Data Exchange (ETDEWEB)

    He, C.-C. [College of Physics, Jilin University, Changchun 130012 (China); Keek, L., E-mail: jordanhe1994@gmail.com [CRESST and X-ray Astrophysics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States)

    2016-03-01

    Emission from neutron stars and accretion disks in low-mass X-ray binaries is anisotropic. The non-spherical shape of the disk as well as blocking of the neutron star by the disk make the observed flux dependent on the inclination angle of the disk with respect to the line of sight. This is of importance for the interpretation of thermonuclear X-ray bursts from neutron stars. Because part of the X-ray burst is reflected off the disk, the observed burst flux depends on the anisotropies for both direct emission from the neutron star and reflection off the disk. This influences measurements of source distance, mass accretion rate, and constraints on the neutron star’s equation of state. Previous predictions of the anisotropy factors assumed a geometrically flat disk. Detailed observations of two so-called superbursts allowed for the direct and the reflected burst fluxes to each be measured separately. The reflection fraction was much higher than what the anisotropies of a flat disk can account for. We create numerical models to calculate the anisotropy factors for different disk shapes, including concave disks. We present the anisotropy factors of the direct and reflected burst fluxes separately, as well as the anisotropy of the persistent flux. Reflection fractions substantially larger than unity are produced in the case where the inner accretion disk increases steeply in height, such that part of the star is blocked from view. Such a geometry could possibly be induced by the X-ray burst if X-ray heating causes the inner disk to puff up.

  3. Loss of anterior concavity of the first sacrum can predict spinal involvement in ankylosing spondylitis.

    Science.gov (United States)

    Kim, Ji Young; Lee, Seunghun; Joo, Kyung Bin; Song, Yoonah; Joo, Young Bin; Kim, Tae-Hwan

    2016-01-01

    In this study, we evaluated the frequency of squaring of the first sacrum (S1), defined as the loss of anterior concavity, in patients with ankylosing spondylitis (AS). We also determined the interobserver reliability in the assessment of S1 squaring and the relationships of S1 squaring with MRI findings and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). To this end, we performed a retrospective study of 100 patients with AS (mean age 33.2 years; range 19-57 years) and 100 control patients (mean age 35.6 years; range 19-50 years). Four experienced radiologists independently assessed the presence of S1 squaring in the AS and control groups. The frequencies of S1 squaring as scored by the four observers were 47, 48, 46, and 42 in the AS group and 3, 6, 4, and 6 in the control group. The interobserver agreement among the four observers with respect to S1 squaring was excellent (κ value 0.80) in the AS group and fair to good (κ value 0.61) in the control group. In patients with AS, the presence of S1 squaring showed fair to good agreement with the MRI changes (κ value 0.74). Moreover, the mSASSSs of patients with versus without S1 squaring were significantly different (mean 23.9 vs 7.0, p < 0.001). In conclusion, S1 squaring is relatively common in patients with AS. Moreover, S1 squaring is closely correlated with MRI changes and significantly associated with the mSASSS. Assessment of S1 squaring could be a simple method that is potentially useful for predicting early spinal structural involvement in patients with AS.

  4. The Interior City. Infinity and Concavity in the No-Stop City(1970-1971

    Directory of Open Access Journals (Sweden)

    Pablo Martínez Capdevila

    2013-10-01

    Full Text Available AbstractIn the late 60s it had become clear how the environment technification had allowed some typologies (supermarkets, car parks, factories to reach potentially unlimited built depths becoming, therefore, independent from the outside. The No-Stop City is born from a very simple idea: to extend this technification to the totality of built reality encompassing, not only almost all functions, but ultimately, the whole city. This operation has paradoxical effects: as architecture grows, it loses most of the features that have traditionally defined it. A dissolution by hypertrophy that gives rise to an homogeneous, concave and potentially infinite space.But beyond the pure technical feasibility, there are two key influences, seemingly contradictory, that explain this endeavor for an interior and endless city: Marxism and Pop Art. The project is, in many senses, a built manifesto reflecting the militancy of the group members within the Italian Marxism. But it is also the embodiment of the group's declared interest in Pop Art, popular culture and mass society. The cross-influence of communism and consumerism explains this "quantitative utopia" in which the society and the factory, the production and consumption, would match. A city based on the centrality of consumer products and the subsequent loss of prominence of architecture, in which the urban phenomenon, while spreading endlessly over territory, ignoring its rural exteriority, dissolves the home as a sphere of privacy, ignoring its domestic interiority.A project, also in the wake of Marshall McLuhan, that illustrates like few others the conversion of the urbane into a virtually omnipresent "condition" and that still interrogates us with questions that are, on the other hand, eternal: What is a building? What is a city?Key wordsBranzi, dissolution, pop, Marxism, neo-avant-garde

  5. Process control plan for tank 241-SY-101 surface level rise remediation

    Energy Technology Data Exchange (ETDEWEB)

    ESTEY, S.D.

    1999-06-29

    The tank 241-SY-101 transfer system was conceived and designed to address the immediate needs presented by rapidly changing waste conditions in tank 241-SY-101. Within the past year or so, the waste in this tank has exhibited unexpected behavior in the form of rapidly increasing crust growth. The Process Control Plan (PCP), HNF-4264, was written to translate high-level guidance and regulatory criteria and express it in terms of operating instructions for the waste transfer system. These controls include: (1) Tank Farm Operations Administrative Controls developed in response to DOE-ORP direction reg,arding supplemental controls placed upon tank 241-SY-101 surface level rise remediation activities specifically involving waste transfer activities. (2) Authorization Basis controls (Basis for Interim Operation (BIO)/Technical Safety Requirements (TSRs)) and supplemental DOE direction. (3) Environmental, Industrial Hygiene and Safety controls. (4) Operating Specification Document (OSD) controls. (5) Good operating practices. Included in the document are descriptions of tank conditions, waste conditions, major equipment, and a high-level overview of the system and the line-ups in which it operates. Primarily, the PCP addresses how the waste transfer will be managed, defining the monitoring and control methods including material balances to determine the progress and to define completion criteria for the transfer. The actual plant modifications and waste transfer will be authorized and controlled by plant procedures.

  6. Holocene depositional environments and surface-level changes at Lake Fryxell, Antarctica

    Science.gov (United States)

    Whittaker, T.E.; Hall, B.L.; Hendy, C.H.; Spaulding, S.A.

    2008-01-01

    We report on Holocene surface-level variations of Lake Fryxell, Antarctica, as determined from multi-proxy analyses of 18 sediment cores. During this time accumulating sediments were predominantly aeolian sand with algal and carbonate laminae. Based on stratigraphy, mineralogy and diatom assemblages we suggest some carbonate laminae were deposited when lake level dropped, leading to concentration and subsequent precipitation of salts. Although lake level appears to have remained relatively stable throughout the Holocene, minor (<4.5 m below present) lowstands occurred at approximately 6400, 4700, 3800 and ??? 1600 cal. yr BP. The stability of Lake Fryxell during the Holocene contrasts with large-scale variability at other Dry Valleys lakes (eg, Lake Vanda) and with suggestions from chemical diffusion models of a near-desiccation at ???1200 cal. yr BP. The reason for the comparative stability of Lake Fryxell is uncertain, but may be the result of basin morphology and the number, aspect and proximity of meltwater sources. ?? 2008 SAGE Publications.

  7. Null tests for oblate spheroids. [aspheric surfaces in reflecting optical system designs

    Science.gov (United States)

    Rodgers, J. M.; Parks, R. E.

    1984-01-01

    In most real cases requiring simple null optics, the optical path difference cannot be reduced to zero but can be kept at a fractional wavelength level so that interferometric data reduction can be used to account for the residual error. In other cases, computer-generated holograms may be used to obtain apparently straight fringes when the desired surface is obtained. Two examples, one involving an f/2.5 concave oblate spheroid and the other a Paul-Baker secondary, are examined. It is shown that although the null tests are not generally perfect, the residual error is small and the tests are simple.

  8. Improving Limit Surface Search Algorithms in RAVEN Using Acceleration Schemes: Level II Milestone

    Energy Technology Data Exchange (ETDEWEB)

    Alfonsi, Andrea [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Rabiti, Cristian [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Sen, Ramazan Sonat [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Smith, Curtis Lee [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2015-07-01

    , subject of the analysis. These methodologies are named, in the RAVEN environment, adaptive sampling strategies. These methodologies infer system responses from surrogate models constructed from already existing samples (produced using high fidelity simulations) and suggest the most relevant location (coordinate in the input space) of the next sampling point to be explored in the uncertain/parametric domain. When using those methodologies, it is possible to understand features of the system response with a small number of carefully selected samples. This report focuses on the development and improvement of the limit surface search. The limit surface is an important concept in system reliability analysis. Without going into the details, which will be covered later in the report, the limit surface could be briefly described as an hyper-surface in the system uncertainty/parametric space separating the regions leading to a prescribed system outcome. For example, if the uncertainty/parametric space is the one generated by the reactor power level and the duration of the batteries, the system is a nuclear power plant and the system outcome discriminating variable is the clad failure in a station blackout scenario, then the limit surface separates the combinations of reactor power level and battery duration that lead to clad failure from the ones that do not.

  9. Using the level set method in geodynamical modeling of multi-material flows and Earth's free surface

    NARCIS (Netherlands)

    Hillebrand, B.; Thieulot, C.; Geenen, T.; Van Den Berg, A. P.; Spakman, W.

    2014-01-01

    The level set method allows for tracking material surfaces in 2-D and 3-D flow modeling and is well suited for applications of multi-material flow modeling. The level set method utilizes smooth level set functions to define material interfaces, which makes the method stable and free of oscillations

  10. Using the level set method in geodynamical modeling of multi-material flows and Earth's free surface

    NARCIS (Netherlands)

    Hillebrand, B.; Thieulot, C.; Geenen, T.; Van Den Berg, A. P.; Spakman, W.

    2014-01-01

    The level set method allows for tracking material surfaces in 2-D and 3-D flow modeling and is well suited for applications of multi-material flow modeling. The level set method utilizes smooth level set functions to define material interfaces, which makes the method stable and free of oscillations

  11. BOREAS Level-2 MAS Surface Reflectance and Temperature Images in BSQ Format

    Science.gov (United States)

    Hall, Forrest G. (Editor); Newcomer, Jeffrey (Editor); Lobitz, Brad; Spanner, Michael; Strub, Richard; Lobitz, Brad

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Aircraft Data Acquisition Program focused on providing the research teams with the remotely sensed aircraft data products they needed to compare and spatially extend point results. The MODIS Airborne Simulator (MAS) images, along with other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes biophysical parameter maps such as surface reflectance and temperature. Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-2 MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C130 navigation data in a MAS scan model. The data are provided in binary image format files.

  12. Simulation of droplet impact on a solid surface using the level contour reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seung Won [Hongik University, Seoul (Korea, Republic of); Juric, Damir [Laboratoire d' Informatique pour la Mecanique et les Sciences de l' Ingenieur, Orsay (France)

    2009-09-15

    We simulate the three-dimensional impact of a droplet onto a solid surface using the level contour reconstruction method (LCRM). A Navier-slip dynamic contact line model is implemented in this method and contact angle hysteresis is accounted for by fixing the contact angle limits to prescribed advancing or receding angles. Computation of a distance function directly from the tracked interface enables a straightforward implementation of the contact line dynamic model in the LCRM. More general and sophisticated contact line models are readily applicable in this front tracking approach with few modifications, since complete knowledge of the geometrical information of the interface in the vicinity of the wall contact region is available. Several validation tests are performed including 2D planar droplet, 2D axisymmetric droplet, and full three-dimensional droplet splashing problems. The results show good agreement compared with existing numerical and experimental solutions

  13. Reduction of endoplasmic reticulum Ca2+ levels favors plasma membrane surface exposure of calreticulin.

    Science.gov (United States)

    Tufi, R; Panaretakis, T; Bianchi, K; Criollo, A; Fazi, B; Di Sano, F; Tesniere, A; Kepp, O; Paterlini-Brechot, P; Zitvogel, L; Piacentini, M; Szabadkai, G; Kroemer, G

    2008-02-01

    Some chemotherapeutic agents can elicit apoptotic cancer cell death, thereby activating an anticancer immune response that influences therapeutic outcome. We previously reported that anthracyclins are particularly efficient in inducing immunogenic cell death, correlating with the pre-apoptotic exposure of calreticulin (CRT) on the plasma membrane surface of anthracyclin-treated tumor cells. Here, we investigated the role of cellular Ca(2+) homeostasis on CRT exposure. A neuroblastoma cell line (SH-SY5Y) failed to expose CRT in response to anthracyclin treatment. This defect in CRT exposure could be overcome by the overexpression of Reticulon-1C, a manipulation that led to a decrease in the Ca(2+) concentration within the endoplasmic reticulum lumen. The combination of Reticulon-1C expression and anthracyclin treatment yielded more pronounced endoplasmic reticulum Ca(2+) depletion than either of the two manipulations alone. Chelation of intracellular (and endoplasmic reticulum) Ca(2+), targeted expression of the ligand-binding domain of the IP(3) receptor and inhibition of the sarco-endoplasmic reticulum Ca(2+)-ATPase pump reduced endoplasmic reticulum Ca(2+) load and promoted pre-apoptotic CRT exposure on the cell surface, in SH-SY5Y and HeLa cells. These results provide evidence that endoplasmic reticulum Ca(2+) levels control the exposure of CRT.

  14. Functional levels of floor surface roughness for the prevention of slips and falls: clean-and-dry and soapsuds-covered wet surfaces.

    Science.gov (United States)

    Kim, In-Ju; Hsiao, Hongwei; Simeonov, Peter

    2013-01-01

    Literature has shown a general trend that slip resistance performance improves with floor surface roughness. However, whether slip resistance properties are linearly correlated with surface topographies of the floors or what roughness levels are required for effective slip resistance performance still remain to be answered. This pilot study aimed to investigate slip resistance properties and identify functional levels of floor surface roughness for practical design applications in reducing the risk of slip and fall incidents. A theory model was proposed to characterize functional levels of surface roughness of floor surfaces by introducing a new concept of three distinctive zones. A series of dynamic friction tests were conducted using 3 shoes and 9 floor specimens under clean-and-dry as well as soapsuds-covered slippery wet environments. The results showed that all the tested floor-shoe combinations provided sufficient slip resistances performance under the clean-and-dry condition. A significant effect of floor type (surface roughness) on dynamic friction coefficient (DFC) was found in the soapsuds-covered wet condition. As compared to the surface roughness effects, the shoe-type effects were relatively small. Under the soapsuds-covered wet condition, floors with 50 μm in Ra roughness scale seemed to represent an upper bound in the functional range of floor surface roughness for slip resistance because further increase of surface roughness provided no additional benefit. A lower bound of the functional range for slip resistance under the soapsuds-covered wet condition was estimated from the requirement of DFC > 0.4 at Ra ≅ 17 μm. Findings from this study may have potential safety implications in the floor surface design for reducing slip and fall hazards.

  15. Empirical Results of a Surface-Level GNSS-R Experiment in a Wave Channel

    Directory of Open Access Journals (Sweden)

    Hugo Carreno-Luengo

    2015-06-01

    Full Text Available The scattering of GNSS signals over a water surface is studied when the receiver is at a low height, as in GNSS-R coastal altimetry. The precise determination of the local sea level and wave state from the coast will provide useful altimetry and wave information as “dry” tide and wave gauges. An experiment has been conducted at the Canal d'Investigació i Experimentació Marítima (CIEM wave channel for two simulated “sea” states. The GNSS-reflectometer used is the P(Y and C/A ReflectOmeter (PYCARO instrument, a closed-loop receiver with delay and Doppler tracking loops that uses the conventional GNSS-R technique for the GPS C/A code. After retracking of the scattered GPS signals, the coherent and incoherent components have been studied. To reproduce the transmitted GPS signals indoors, a Rohde and Schwarz signal generator is used. It is found that, despite the ratio of the coherent and incoherent components being ~1, the coherent component is strong enough that it can be tracked. The coherent component comes from clusters of points on the surface that approximately satisfy the specular reflection conditions (“roughed facet”. The Pearson’s linear correlation coefficients of the derived “sea” surface height with the wave gauge data are: 0.78, 0.85 and 0.81 for a SWH = 36 cm and 0.34, 0.74, and 0.72 for a SWH = 64 cm, respectively, for transmitter elevation angles of = 60°, 75° and 86°, respectively. Finally, the rms phase of the received signal before the retracking processing is used to estimate the effective rms surface height of the ‘facets’, where the waves get scattered. It is found to be between 2.5- and 4.1-times smaller than the theoretical values corresponding to the half of the coherent reflectivity decaying factor.

  16. Fabrication of piezoelectric P(VDF-TrFE) microcantilevers by wafer-level surface micromachining

    Science.gov (United States)

    Oh, Sharon Roslyn; Yao, Kui; Eng Hock Tay, Francis

    2013-09-01

    A wafer-level microfabrication process using standard cleanroom facilities was established and implemented to batch produce free-standing poly(vinylidine fluoride-trifluoroethylene) (P(VDF-TrFE)) piezoelectric microelectromechanical systems cantilevers via surface micromachining. Furthermore, the fabrication of a prototype of double-level cantilevers was demonstrated. The fabrication of working piezoelectric polymer cantilever structures required the deposition and patterning of multiple polymer and metal layers including the pattering and removal of the sacrificial layer, which posed many challenging limitations on the chemicals and processing conditions. Dedicatedly selected chemicals and materials were used in our fabrication, including water soluble PVA with an appropriate molecular weight and degree of hydrolysis as the sacrificial layer for releasing the cantilever structure. The temperature in the whole process was kept low with controlled durations, due to the sensitivity of the polymers to thermal impacts. The P(VDF-TrFE) active layers, after going through the fabrication, exhibited ferroelectric and piezoelectric properties comparable to the intact films. Furthermore, the free-standing P(VDF-TrFE) cantilevers exhibited piezoelectric vibrations under electrical excitation. This low temperature fabrication method, which only involves mild chemicals, also has the potential to be integrated with CMOS processes.

  17. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance.

    Science.gov (United States)

    Pozo, Antonio M; Pérez-Ocón, Francisco; Rabaza, Ovidio

    2016-05-19

    A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR) to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel) and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU(-1) and a resolution of between 5.7 × 10(-4) and 16.5 × 10(-4) RIU.

  18. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance

    Science.gov (United States)

    Pozo, Antonio M.; Pérez-Ocón, Francisco; Rabaza, Ovidio

    2016-01-01

    A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR) to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel) and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU−1 and a resolution of between 5.7 × 10−4 and 16.5 × 10−4 RIU. PMID:27213388

  19. A Continuous Liquid-Level Sensor for Fuel Tanks Based on Surface Plasmon Resonance

    Directory of Open Access Journals (Sweden)

    Antonio M. Pozo

    2016-05-01

    Full Text Available A standard problem in large tanks at oil refineries and petrol stations is that water and fuel usually occupy the same tank. This is undesirable and causes problems such as corrosion in the tanks. Normally, the water level in tanks is unknown, with the problems that this entails. We propose herein a method based on surface plasmon resonance (SPR to detect in real time the interfaces in a tank which can simultaneously contain water, gasoline (or diesel and air. The plasmonic sensor is composed of a hemispherical glass prism, a magnesium fluoride layer, and a gold layer. We have optimized the structural parameters of the sensor from the theoretical modeling of the reflectance curve. The sensor detects water-fuel and fuel-air interfaces and measures the level of each liquid in real time. This sensor is recommended for inflammable liquids because inside the tank there are no electrical or electronic signals which could cause explosions. The sensor proposed has a sensitivity of between 1.2 and 3.5 RIU−1 and a resolution of between 5.7 × 10−4 and 16.5 × 10−4 RIU.

  20. Levels of Organochlorine Pesticides and Heavy Metals in Surface Waters of Konya Closed Basin, Turkey

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Aydin

    2013-01-01

    Full Text Available The concentrations of organochlorine pesticides (OCPs, including α-, β-, γ-, and δ-hexachlorocyclohexane (HCH, heptachlor, heptachlor epoxide, dieldrin, aldrin, endrin, endrin aldehyde, endrin ketone, endosulfan I, endosulfan II, endosulfan sulfate, p,p′-DDE, p,p′-DDD, p,p′-DDT, methoxychlor, chlordane I, chlordane II, and heavy metals, such as As, Cr, Cu, Fe, Mn, and Ni in surface water samples from the Konya closed basin were determined to evaluate the level of contamination. Among all HCH isomers, β-HCH is the main isomer with a concentration range of 0.015–0.065 μg/L. DDE, DDD, and DDT were almost determined in all samples, in which DDE isomer had the highest concentration ranged from not detected to 0.037 μg/L. In all studied OCPs, aldrin showed the highest concentration at 0.220 μg/L. The concentrations of heavy metals in water samples were observed with order: Mn < Cu < Ni < As < Cr < Fe. In some samples, As, Fe, and Cr concentrations exceeded the drinking water quality recommended by EU, US EPA, WHO, and Turkish Regulation, while Cu, Ni, and Mn concentrations are below the guideline values. The levels of both OCPs and heavy metals were also compared with other previously published data.

  1. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

    Science.gov (United States)

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-05-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds.

  2. An Analysis of the Steric Sea Level Change by Introducing Sea Surface Temperature

    Institute of Scientific and Technical Information of China (English)

    SUN Ruili; LI Lei; LI Peiliang

    2013-01-01

    In this paper,we use the optimum interpolation sea surface temperature (OISST) provided by the National Center for Environmental Prediction (NCEP) to replace the temperature in the top three layers in the ISHII data,and make use of the modified ISHII temperature data to calculate the thermosteric sea level (called modified steric sea level (SSL) hereafter).We subtract the modified SSL and the steric sea level (called ordinary SSL hereafter) derived from the ISHII temperature and salinity from the steric sea level (SSL) provided by the Gravity Recovery and Climate Experiment (GRACE),respectively,and find that the rms error of the difference of the former is obviously smaller than that of the latter.Therefore we reach the conclusion that under the assumption that the GRACE SSL is accurate,the modified SSL can reflect the true steric sea level more accurately.Making use of the modified SSL,we can find that the modified SSL in sea areas of different spatial scales shows an obvious rising trend in the upper 0-700 m layer for the period 1982-2006.The global mean SSL rises with a rate of 0.6 mm year-1.The modified SSLs in sea areas of different spatial scales all show obvious oscillations with period of one year.There are oscillations with periods of 4-8 years in global oceans and with periods of 2-7 years in the Pacific.The Empirical Orthogonal Function method is applied to the sea areas of different spatial scales and we find that the first modes all have obvious 1-year period oscillations,the first mode of the global ocean has 4-8 year period oscillations,and that of the Pacific has 2-6 year period oscillations.The spatial distribution of the linear rising trend of the global modified SSL in the upper 0-700 m layer is inhomogeneous with intense regional characteristics.The modified SSL linear trend indicates a zonal dipole in the tropical Pacific,rising in the west and descending in the east.In the North Atlantic,the modified SSL indicates a meridional dipole,rising in

  3. Direct Measurements of Fermi Level Pinning at the Surface of Intrinsically n-Type InGaAs Nanowires.

    Science.gov (United States)

    Speckbacher, Maximilian; Treu, Julian; Whittles, Thomas J; Linhart, Wojciech M; Xu, Xiaomo; Saller, Kai; Dhanak, Vinod R; Abstreiter, Gerhard; Finley, Jonathan J; Veal, Tim D; Koblmüller, Gregor

    2016-08-10

    Surface effects strongly dominate the intrinsic properties of semiconductor nanowires (NWs), an observation that is commonly attributed to the presence of surface states and their modification of the electronic band structure. Although the effects of the exposed, bare NW surface have been widely studied with respect to charge carrier transport and optical properties, the underlying electronic band structure, Fermi level pinning, and surface band bending profiles are not well explored. Here, we directly and quantitatively assess the Fermi level pinning at the surfaces of composition-tunable, intrinsically n-type InGaAs NWs, as one of the prominent, technologically most relevant NW systems, by using correlated photoluminescence (PL) and X-ray photoemission spectroscopy (XPS). From the PL spectral response, we reveal two dominant radiative recombination pathways, that is, direct near-band edge transitions and red-shifted, spatially indirect transitions induced by surface band bending. The separation of their relative transition energies changes with alloy composition by up to more than ∼40 meV and represent a direct measure for the amount of surface band bending. We further extract quantitatively the Fermi level to surface valence band maximum separation using XPS, and directly verify a composition-dependent transition from downward to upward band bending (surface electron accumulation to depletion) with increasing Ga-content x(Ga) at a crossover near x(Ga) ∼ 0.2. Core level spectra further demonstrate the nature of extrinsic surface states being caused by In-rich suboxides arising from the native oxide layer at the InGaAs NW surface.

  4. Experimental study on particulate materials collected by a concave of sea floor; Kaitei kubochi ni hoshusareru ryujobutsu ni kansuru jikkenteki kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hoshika, A.; Tanimoto, T. [Government Industrial Research Chugoku, Hiroshima (Japan)

    1996-07-10

    As one of the method of sea cleaning method, an idea where concave is dredged on the sea floor and suspended substances and polluted sediment particles are collected, is popular. In this research, simple experiment was carried out for collecting the materials by using a polyvinylchloride cylindrical vessel (50cm in diameter, 70cm in depth) set on the sea floor of Osaka Bay area and fundamental study about the quality of collected materials, collection effectiveness and so forth was carried out. Further, along with the collection experiment, measurement of degree of pollution and investigation of bottom laminar flow which is thought to be the direct outer force for particulate material movement were carried out in order to study the flow mechanism of particulate materials. As a result, with the setting of collection vessel, particulate materials about 9 times more than that of estimated natural sedimentation amount were collected. This corresponds to the 5% of the horizontal flux of suspended substances in the bottom layer water. Among the collected particulate materials, about 30% are suspended substances, about 70% are surface sediment substances. This kind of method, when combined suitably with the method for removing collected particulate materials, can be one of the effective method for the purification of polluted sediment materials. 8 refs., 9 figs., 3 tabs.

  5. Semi-Automated Detection of Surface Degradation on Bridges Based on a Level Set Method

    Science.gov (United States)

    Masiero, A.; Guarnieri, A.; Pirotti, F.; Vettore, A.

    2015-08-01

    Due to the effect of climate factors, natural phenomena and human usage, buildings and infrastructures are subject of progressive degradation. The deterioration of these structures has to be monitored in order to avoid hazards for human beings and for the natural environment in their neighborhood. Hence, on the one hand, monitoring such infrastructures is of primarily importance. On the other hand, unfortunately, nowadays this monitoring effort is mostly done by expert and skilled personnel, which follow the overall data acquisition, analysis and result reporting process, making the whole monitoring procedure quite expensive for the public (and private, as well) agencies. This paper proposes the use of a partially user-assisted procedure in order to reduce the monitoring cost and to make the obtained result less subjective as well. The developed method relies on the use of images acquired with standard cameras by even inexperienced personnel. The deterioration on the infrastructure surface is detected by image segmentation based on a level sets method. The results of the semi-automated analysis procedure are remapped on a 3D model of the infrastructure obtained by means of a terrestrial laser scanning acquisition. The proposed method has been successfully tested on a portion of a road bridge in Perarolo di Cadore (BL), Italy.

  6. Crystal Quality and Light Output Power of GaN-Based LEDs Grown on Concave Patterned Sapphire Substrate.

    Science.gov (United States)

    Wu, YewChung Sermon; Isabel, A Panimaya Selvi; Zheng, Jian-Hsuan; Lin, Bo-Wen; Li, Jhen-Hong; Lin, Chia-Chen

    2015-04-22

    The crystal quality and light output power of GaN-based light-emitting diodes (LEDs) grown on concave patterned sapphire substrate (CPSS) were investigated. It was found that the crystal quality of GaN-based LEDs grown on CPSS improved with the decrease of the pattern space (percentage of c-plane). However, when the pattern space decreased to 0.41 μm (S0.41-GaN), the GaN crystallinity dropped. On the other hand, the light output power of GaN-based LEDs was increased with the decrease of the pattern space due to the change of the light extraction efficiency.

  7. Combining Convex-Concave Decompositions and Linearization Approaches for solving BMIs, with application to Static Output Feedback

    CERN Document Server

    Dinh, Quoc Tran; Michiels, Wim; Diehl, Moritz

    2011-01-01

    A novel optimization method is proposed to minimize a convex function subject to bilinear matrix inequality (BMI) constraints. The key idea is to decompose the bilinear mapping as a difference between two positive semidefinite convex mappings. At each iteration of the algorithm the concave part is linearized, leading to a convex subproblem.Applications to various output feedback controller synthesis problems are presented. In these applications the subproblem in each iteration step can be turned into a convex optimization problem with linear matrix inequality (LMI) constraints. The performance of the algorithm has been benchmarked on the data from COMPleib library.

  8. Impacts of Future Climate Change and Baltic Sea Level Rise on Groundwater Recharge, Groundwater Levels, and Surface Leakage in the Hanko Aquifer in Southern Finland

    Directory of Open Access Journals (Sweden)

    Samrit Luoma

    2014-11-01

    Full Text Available The impact of climate change and Baltic Sea level rise on groundwater resources in a shallow, unconfined, low-lying coastal aquifer in Hanko, southern Finland, was assessed using the UZF1 model package coupled with the three-dimensional groundwater flow model MODFLOW to simulate flow from the unsaturated zone through the aquifer. The snow and PET models were used to calculate the surface water availability for infiltration from the precipitation data used in UZF1. Infiltration rate, flow in the unsaturated zone and groundwater recharge were then simulated using UZF1. The simulation data from climate and sea level rise scenarios were compared with present data. The results indicated changes in recharge pattern during 2071–2100, with recharge occurring earlier in winter and early spring. The seasonal impacts of climate change on groundwater recharge were more significant, with surface overflow resulting in flooding during winter and early spring and drought during summer. Rising sea level would cause some parts of the aquifer to be under sea level, compromising groundwater quality due to intrusion of sea water. This, together with increased groundwater recharge, would raise groundwater levels and consequently contribute more surface leakage and potential flooding in the low-lying aquifer.

  9. Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

    Science.gov (United States)

    Brakenridge, G. R.; Birkett, C. M.

    2013-12-01

    Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage

  10. Contamination levels of human pharmaceutical compounds in French surface and drinking water.

    OpenAIRE

    Mompelat, S.; Thomas, Olivier; Le Bot, Barbara

    2011-01-01

    International audience; The occurrence of 20 human pharmaceutical compounds and metabolites from 10 representative therapeutic classes was analysed from resource and drinking water in two catchment basins located in north-west France. 98 samples were analysed from 63 stations (surface water and drinking water produced from surface water). Of the 20 human pharmaceutical compounds selected, 16 were quantified in both the surface water and drinking water, with 22% of the values above the limit o...

  11. Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks.

    Science.gov (United States)

    Li, Hong-Bo; Yu, Shen; Li, Gui-Lin; Liu, Yi; Yu, Guang-Bin; Deng, Hong; Wu, Sheng-Chun; Wong, Ming-Hung

    2012-08-15

    Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (<63 μm) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous.

  12. Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong-Bo [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Shen, E-mail: syu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Li, Gui-Lin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Liu, Yi; Yu, Guang-Bin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Deng, Hong [Department of Environmental Sciences, Tiantong National Station of Forest Ecosystem, Key Laboratory of Urbanization and Ecological Restoration, East China Normal University, Shanghai 200062 (China); Wu, Sheng-Chun [State Key Laboratory in Marine Pollution, Biology and Chemistry Department, City University of Hong Kong, Hong Kong (China); Wong, Ming-Hung [Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong (China)

    2012-08-15

    Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (< 63 {mu}m) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous. -- Highlights: Black-Right-Pointing-Pointer Obvious

  13. In-situ surface wettability parameters of submerged in brackish water surfaces derived from captive bubble contact angle studies as indicators of surface condition level

    Science.gov (United States)

    Pogorzelski, S. J.; Mazurek, A. Z.; Szczepanska, A.

    2013-06-01

    The characterization of wetting properties (by contact angles) of several undersea artificial (glass plates,) and natural (stones, sand layers, soft-bottom structures, aquatic macrophytes, sediments, and seafloor communities) solid substrata in the Baltic Sea brackish water (Gulf of Gdansk). The studies were performed under laboratory and field conditions using a novel captive bubble air-pipette computer microscope system. A set of the surface wettability parameters: the apparent surface free energy γSV, adhesive layer film pressure Π, work of adhesion WA, and work of spreading WS were determined to quantify the wetting properties of model substrata using the contact angle hysteresis (CAH) approach. The useful technique to measure in situ the contact angle giving reproducible and accurate values of CA turned out to be a captive bubble method, for fully hydrated interfacial layers of highly hydrophilic and porous nature met at seabed (Rodrigues-Valverde et al., 2002). CA measurements revealed mostly hydrophilic nature of the studied solid material (CA oil film covering lead to surface hydrophobization (CA↑, γSV ↓,WA↓, WS more negative). The adhesion of biofouling was correlated both with CAH and the dispersive interaction term γSVd of the total γSV. Monitoring of the artificial substrata of the hydrophilic nature with a CA technique can be used to observe the development of the organisms community i.e., microfouling, and to carry out a comprehensive study of surfaces of the submerged macrophytes (Potamogeton lucens in particular). Since aquatic macrophytes can act as bio-indicators of water chemistry their surface wettability may reflect plant surface erosion and organic matter accumulation state being of particular value in biological assessment of ecosystems status.

  14. Error Rates of the Maximum-Likelihood Detector for Arbitrary Constellations: Convex/Concave Behavior and Applications

    CERN Document Server

    Loyka, Sergey; Gagnon, Francois

    2009-01-01

    Motivated by a recent surge of interest in convex optimization techniques, convexity/concavity properties of error rates of the maximum likelihood detector operating in the AWGN channel are studied and extended to frequency-flat slow-fading channels. Generic conditions are identified under which the symbol error rate (SER) is convex/concave for arbitrary multi-dimensional constellations. In particular, the SER is convex in SNR for any one- and two-dimensional constellation, and also in higher dimensions at high SNR. Pairwise error probability and bit error rate are shown to be convex at high SNR, for arbitrary constellations and bit mapping. Universal bounds for the SER 1st and 2nd derivatives are obtained, which hold for arbitrary constellations and are tight for some of them. Applications of the results are discussed, which include optimum power allocation in spatial multiplexing systems, optimum power/time sharing to decrease or increase (jamming problem) error rate, an implication for fading channels ("fa...

  15. Flexible Helicoids, Atomic Force Microscopy (AFM Cantilevers in High Mode Vibration, and Concave Notch Hinges in Precision Measurements and Research

    Directory of Open Access Journals (Sweden)

    Yakov Tseytlin

    2012-05-01

    Full Text Available Flexible structures are the main components in many precision measuring and research systems. They provide miniaturization, repeatability, minimal damping, low measuring forces, and very high resolution. This article focuses on the modeling, development, and comparison of three typical flexible micro- nano-structures: flexible helicoids, atomic force microscopy (AFM cantilevers, and concave notch hinges. Our theory yields results which allow us to increase the accuracy and functionality of these structures in new fields of application such as the modeling of helicoidal DNA molecules’ mechanics, the definition of instantaneous center of rotation in concave flexure notch hinges, and the estimation of the increase of spring constants and resolution at higher mode vibration in AFM cantilevers with an additional concentrated and end extended mass. We developed the original kinetostatic, reverse conformal mapping of approximating contours, and non-linear thermomechanical fluctuation methods for calculation, comparison, and research of the micromechanical structures. These methods simplify complicated solutions in micro elasticity but provide them with necessary accuracy. All our calculation results in this article and in all corresponding referenced author’s publications are in a good agreement with experimental and finite element modeling data within 10% or less.

  16. A free energy-based surface tension force model for simulation of multiphase flows by level-set method

    Science.gov (United States)

    Yuan, H. Z.; Chen, Z.; Shu, C.; Wang, Y.; Niu, X. D.; Shu, S.

    2017-09-01

    In this paper, a free energy-based surface tension force (FESF) model is presented for accurately resolving the surface tension force in numerical simulation of multiphase flows by the level set method. By using the analytical form of order parameter along the normal direction to the interface in the phase-field method and the free energy principle, FESF model offers an explicit and analytical formulation for the surface tension force. The only variable in this formulation is the normal distance to the interface, which can be substituted by the distance function solved by the level set method. On one hand, as compared to conventional continuum surface force (CSF) model in the level set method, FESF model introduces no regularized delta function, due to which it suffers less from numerical diffusions and performs better in mass conservation. On the other hand, as compared to the phase field surface tension force (PFSF) model, the evaluation of surface tension force in FESF model is based on an analytical approach rather than numerical approximations of spatial derivatives. Therefore, better numerical stability and higher accuracy can be expected. Various numerical examples are tested to validate the robustness of the proposed FESF model. It turns out that FESF model performs better than CSF model and PFSF model in terms of accuracy, stability, convergence speed and mass conservation. It is also shown in numerical tests that FESF model can effectively simulate problems with high density/viscosity ratio, high Reynolds number and severe topological interfacial changes.

  17. Abdominal strengthening using the AbVice machine as measured by surface electromyographic activation levels.

    Science.gov (United States)

    Avedisian, Lori; Kowalsky, Don S; Albro, Richard C; Goldner, Daniel; Gill, Robert C

    2005-08-01

    Twenty-four college students served as subjects in a study that examined the effect of a prototypical abdominal muscle strengthening device (AbVice) compared with other devices currently on the market. The purpose of the present study was to investigate a prototypical device (AbVice) that incorporates contraction of the hamstring and gluteal musculature in conjunction with the abdominals, which may assist in decreasing activation of the hip flexors by allowing greater activity levels of the abdominal musculature via the theory of reflex inhibition, compared with other devices currently available on the market (AbRoller and AbRocker). The repeated-measures study included 17 women and 7 men who ranged in age from 20-23 years (mean +/- SD age, 21.3 +/- 1.5 years). Each subject underwent a single session of data collection during which they completed 10 repetitions of abdominal crunches per device. Subjects completed 4 different crunch sets (AbRocker, AbRoller, standard crunch, AbVice). Counterbalancing of the device was used to negate the effect of fatigue. Speed of repetitions was ensured via use of a metronome set at 40 b.min(-1) to permit similar contraction times and rest periods between repetitions. Rest between conditions was 3 minutes. Mean activation levels of surface electromyography (EMG) were recorded for each condition at the following locations on the right side of the body: rectus abdominis 2.5 cm superior to the umbilicus, rectus abdominis 2.5 cm inferior to the umbilicus, external oblique abdominis 1.0 cm medial to the anterior superior iliac spine, and external oblique abdominis less than 1.0 cm superior to the inguinal ligament. Mean (SD) activation was 1,165.21 mV (634.60 mV) with the AbVice, 242.92 mV (263.03 mV) with the AbRocker, 753.29 mV (514.80 mV) with the standard crunch, and 757.67 mV (542.85 mV) with the AbRoller. Broken down by sex, women had the following mean (SD) EMG values: 1,079.76 mV (705.02 mV) with the AbVice, 680.35 mV (535.35 m

  18. Surface tension, viscosity, and rheology of water-based nanofluids: a microscopic interpretation on the molecular level

    Science.gov (United States)

    Lu, Gui; Duan, Yuan-Yuan; Wang, Xiao-Dong

    2014-09-01

    Nanofluids are suspensions of nanometer-sized particles which significantly modify the properties of the base fluids. Nanofluids exhibit attractive properties, such as high thermal conductivity, tunable surface tension, viscosity, and rheology. Various attempts have been made to understand the mechanisms for these property modifications caused by adding nanoparticles; however, due to the lack of direct nanoscale evidence, these explanations are still controversial. This work calculated the surface tension, viscosity, and rheology of gold-water nanofluids using molecular dynamics simulations which provide a microscopic interpretation for the modified properties on the molecular level. The gold-water interaction potential parameters were changed to mimic various nanoparticle types. The results show that the nanoparticle wettability is responsible for the modified surface tension. Hydrophobic nanoparticles always tend to stay on the free surface so they behave like a surfactant to reduce the surface tension. Hydrophilic nanoparticles immersed into the bulk fluid impose strong attractive forces on the water molecules at the free surface which reduces the free surface thickness and increases the surface tension of the nanofluid. Solid-like absorbed water layers were observed around the nanoparticles which increase the equivalent nanoparticle radius and reduce the mobility of the nanoparticles within the base fluid which increases the nanofluid viscosity. The results show the water molecule solidification between two or many nanoparticles at high nanoparticle loadings, but the solidification effect is suppressed for shear rates greater than a critical shear rate; thus Newtonian nanofluids can present shear-thinning non-Newtonian behavior.

  19. Pressurizable structures comprising different surface sections

    NARCIS (Netherlands)

    Koussios, S.; Bergsma, O.K.; Beukers, A.

    2004-01-01

    The invention relates to composite pressurizable structures which are overwound with fibres or are braided. The pressurizable structures comprise axial sections which in turn comprise both concave and convex surfaces. The shape characteristics are related to geodesic as well as non-geodesic trajecto

  20. Monitoring of ppm level humic acid in surface water using ZnO-chitosan nano-composite as fluorescence probe

    Science.gov (United States)

    Basumallick, Srijita; Santra, Swadeshmukul

    2017-05-01

    Surface water contains natural pollutants humic acid (HA) and fulvic acid at ppm level which form carcinogenic chloro-compounds during chlorination in water treatment plants. We report here synthesis of ZnO-chitosan (CS) nano-composites by simple hydrothermal technique and examined their application potential as fluorescent probe for monitoring ppm level HA. These ZnO-CS composites have been characterized by HRTEM, EDX, FTIR, AFM and Fluorescence Spectra. HRTEM images show the formation of ZnO-CS nano-composites of average diameter of 50-250 nm. Aqueous dispersions of these nano-composites show fluorescence emission at 395 nm when excited at 300 nm which is strongly quenched by ppm level HA indicating their possible use in monitoring ppm level HA present in surface water.

  1. Can a global model reproduce observed trends in summertime surface ozone levels?

    OpenAIRE

    S. Koumoutsaris; I. Bey

    2012-01-01

    Quantifying trends in surface ozone concentrations are critical for assessing pollution control strategies. Here we use observations and results from a global chemical transport model to examine the trends (1991–2005) in daily maximum 8-hour average concentrations in summertime surface ozone at rural sites in Europe and the United States. We find a decrease in observed ozone concentrations at the high end of the probability distribution at many of the sites in both regions. The model attribut...

  2. Limiting Factors for Satellite-Based Retrievals of Surface-Level Carbon Monoxide

    Science.gov (United States)

    Martinez-Alonso, S.; Deeter, M. N.; Worden, H. M.; Barré, J.

    2015-12-01

    CO is mostly produced in the lower troposphere by incomplete combustion of biomass and fuels. CO oxidation consumes ~75% of the tropospheric OH, which then is not available to remove CH4 and other greenhouse gases. CO oxidation also leads to the production of tropospheric O3. These critical impacts of CO on air quality and climate require accurate determination of the abundance and evolution of CO near the surface.Satellite retrievals would be well-suited to monitor surface CO globally. However, how do they compare to actual surface abundances? Some aspects to be considered include: the vertical sensitivity of retrievals (given by the averaging kernels), or how thick are the atmospheric layers that can be resolved; the vertical correlation length of CO with respect to the thickness of those layers; and the horizontal variability of CO with respect to the instrument's footprint.To investigate these questions we analyze MOPITT retrievals, DISCOVER-AQ and NOAA profiles, as well as WDCGG surface measurements. MOPITT, on board NASA's Terra satellite, has been measuring tropospheric CO since 2000, providing the longest global CO record to date. Its unique multispectral CO product offers enhanced sensitivity to CO near the surface. Vertical profiles of the lower troposphere were acquired during the DISCOVER-AQ airborne campaigns over selected regions of the USA. NOAA's airborne flask sampling program results in a multi-year, multi-seasonal record of vertical profiles from near the surface up to the mid troposphere, acquired over a number of stations, mostly in North America. Long-term, cross-calibrated surface CO data from ground stations worldwide are available through the WDCGG.Statistical analyses of the DISCOVER-AQ and NOAA profiles indicate that surface vertical correlation length varies greatly depending on geographic location. This may explain contrasting results obtained for different ground stations when comparing MOPITT and WDCGG co-located data and timeseries.

  3. Contamination levels of human pharmaceutical compounds in French surface and drinking water.

    Science.gov (United States)

    Mompelat, S; Thomas, O; Le Bot, B

    2011-10-01

    The occurrence of 20 human pharmaceutical compounds and metabolites from 10 representative therapeutic classes was analysed from resource and drinking water in two catchment basins located in north-west France. 98 samples were analysed from 63 stations (surface water and drinking water produced from surface water). Of the 20 human pharmaceutical compounds selected, 16 were quantified in both the surface water and drinking water, with 22% of the values above the limit of quantification for surface water and 14% for drinking water). Psychostimulants, non-steroidal anti-inflammatory drugs, iodinated contrast media and anxiolytic drugs were the main therapeutic classes of human pharmaceutical compounds detected in the surface water and drinking water. The results for surface water were close to results from previous studies in spite of differences in prescription rates of human pharmaceutical compounds in different countries. The removal rate of human pharmaceutical compounds at 11 water treatment units was also determined. Only caffeine proved to be resistant to drinking water treatment processes (with a minimum rate of 5%). Other human pharmaceutical compounds seemed to be removed more efficiently (average elimination rate of over 50%) by adsorption onto activated carbon and oxidation/disinfection with ozone or chlorine (not taking account of the disinfection by-products). These results add to the increasing evidence of the occurrence of human pharmaceutical compounds in drinking water that may represent a threat to human beings exposed to a cocktail of human pharmaceutical compounds and related metabolites and by-products in drinking water.

  4. Preliminary evaluation of two new cable surface innovations

    DEFF Research Database (Denmark)

    Burlina, Celeste; Georgakis, Christos T.; Larsen, S.V.;

    2015-01-01

    In this paper, the aerodynamic performance of two innovative bridge cable surfaces with concave fillets are examined and compared with traditional helical fillets. To this end, an extensive wind-tunnel test campaign was undertaken to measure the aerodynamic static force coefficients up to a Reyno......In this paper, the aerodynamic performance of two innovative bridge cable surfaces with concave fillets are examined and compared with traditional helical fillets. To this end, an extensive wind-tunnel test campaign was undertaken to measure the aerodynamic static force coefficients up...... to a Reynolds number of 3.2 x 105. The tests confirmed the results obtained from the preliminary tests performed by Kleissl and Georgakis (2013) on the prototype cable surfaces with the concave fillets. Despite a more than 100% increase of the fillet height compared to a traditional helical fillet profile...

  5. 凹资源配置问题的混合动态规划方法%A Hybrid Dynamic Programming Method for Concave Resource Allocation Problems

    Institute of Scientific and Technical Information of China (English)

    姜计荣; 孙小玲

    2005-01-01

    Concave resource allocation problem is an integer programming problem of minimizing a nonincreasing concave function subject to a convex nondecreasing constraint and bounded integer variables. This class of problems are encountered in optimization models involving economies of scale. In this paper, a new hybrid dynamic programming method was proposed for solving concave resource allocation problems. A convex underestimating function was used to approximate the objective function and the resulting convex subproblem was solved with dynamic programming technique after transforming it into a 0-1 linear knapsack problem. To ensure the convergence, monotonicity and domain cut technique was employed to remove certain integer boxes and partition the Reviseddomain into a union of integer boxes. Computational results were given to show the efficiency of the algorithm.

  6. Draft Genome Sequences of Biosafety Level 2 Opportunistic Pathogens Isolated from the Environmental Surfaces of the International Space Station.

    Science.gov (United States)

    Checinska Sielaff, Aleksandra; Singh, Nitin K; Allen, Jonathan E; Thissen, James; Jaing, Crystal; Venkateswaran, Kasthuri

    2016-12-29

    The draft genome sequences of 20 biosafety level 2 (BSL-2) opportunistic pathogens isolated from the environmental surfaces of the International Space Station (ISS) were presented. These genomic sequences will help in understanding the influence of microgravity on the pathogenicity and virulence of these strains when compared with Earth strains.

  7. Fusion to green fluorescent protein improves expression levels of Theileria parva sporozoite surface antigen p67 in insect cells

    NARCIS (Netherlands)

    Kaba, S.A.; Nene, V.; Musoke, A.J.; Vlak, J.M.; Oers, van M.M.

    2002-01-01

    East Coast fever (ECF) is a fatal disease of cattle caused by the protozoan parasite Theileria parva. The development of a subunit vaccine, based on the sporozoite-specific surface antigen p67, has been hampered by difficulties in achieving high-level expression of recombinant p67 in a near-authenti

  8. Effects of rice harvest moisture on kernel damage and milled rice surface free fatty acid levels.

    Science.gov (United States)

    Parker, Amanda M; Proctor, Andrew; Eason, Robert L; Jain, Vishal

    2007-01-01

    Surface free fatty acid (FFA) on milled rice is a key factor in determining rice quality and acceptability to the brewing industry. Rice FFA oxidizes, causing off-flavors and odors to develop, compromising the brewing quality of milled rice. The effect of harvest moisture (13%, 16%, and 20%), harvester type (1688 Case and 9500 John Deere), and rice variety (Cocodrie and Bengal) on harvest damaged rough rice and milled rice surface FFA after drying to 12% moisture and 6 mo rough rice storage was examined. The Case harvester produced more damaged kernels than the John Deere harvester, but this was not reflected in surface FFA development. There were no significant FFA differences in variety or harvester type. Rice harvested at a higher moisture content (20%) produced significantly greater FFA values, with a peak near 0.1%, than rice harvested at lower moisture contents (13% and 16%), which had FFA values near 0.08%. Retention of bran by damaged kernels at high harvest moisture probably was responsible for promoting surface FFA development, but if bran was lost at lower harvest moistures, surface FFA, development was limited. Harvest moisture affected milled rice FFA, although rough rice was dried to 12% immediately after harvesting.

  9. Correlating the Local Defect-Level Density with the Macroscopic Composition and Energetics of Chalcopyrite Thin-Film Surfaces.

    Science.gov (United States)

    Bröker, Sebastian; Kück, Dennis; Timmer, Alexander; Lauermann, Iver; Ümsür, Bünyamin; Greiner, Dieter; Kaufmann, Christian A; Mönig, Harry

    2015-06-17

    The unusual defect chemistry of polycrystalline Cu(In,Ga)Se2 (CIGSe) thin films is a main issue for a profound understanding of recombination losses in chalcopyrite thin-film solar cells. Especially, impurity-driven passivation of electronic levels due to point defects segregating at the surface and at grain boundaries is extensively debated. By combining current imaging tunneling spectroscopy with photoelectron spectroscopy, the local defect-level density and unusual optoelectronic grain-boundary properties of this material are correlated with the macroscopic energy levels and surface composition. Vacuum annealing of different CIGSe materials provides evidence that Na diffusion from the glass substrate does not affect the surface defect passivation or grain-boundary properties of standard Cu-poor materials. Furthermore, we find no major impact on the observed thermally activated dipole compensation or the accompanying change in surface band bending (up to 0.6 eV) due to Na. In contrast, Cu-rich CIGSe shows an opposing surface defect chemistry with only minor heat-induced band bending. Our results lead to a comprehensive picture, where the highly desirable type inversion at the p/n interface in standard chalcopyrite thin-film solar cells is dominated by band bending within the CIGSe absorber rather than the result of Na impurities or an n-type defect phase segregating at the interface. This is in accordance with recent studies suggesting a surface reconstruction as the origin for Cu depletion and band-gap widening at the surface of chalcopyrite thin films.

  10. Decreases in CD31 and CD47 levels on the cell surface during etoposide-induced Jurkat cell apoptosis.

    Science.gov (United States)

    Azuma, Yutaro; Nakagawa, Hideaki; Dote, Kanae; Higai, Koji; Matsumoto, Kojiro

    2011-01-01

    Engulfment of apoptotic cells is regulated by 'eat me' and 'don't eat me' signals on the cell surface. Alterations to the 'eat me' signals have been well described; however, very little is known about the 'don't eat me' signals on the cell surface during apoptosis. In the present study, apoptosis of Jurkat cells was induced by treatment with topoisomerase II inhibitor etoposide, and then the CD31 and CD47 levels on the apoptotic cell surface and in microparticles were estimated by flow cytometry and immunoblotting methods in the presence of caspase, metalloproteinase, and Rho-associated coiled-coil containing protein kinase 1 (ROCK1) inhibitors. The CD31 and CD47 levels on the cell surface of apoptotic Jurkat cells had decreased after treatment with etoposide. These decreases in CD31 and CD47 levels on the apoptotic cell surface were almost completely suppressed by the caspase 3 inhibitor, Ac-DEVD-CHO, and partially suppressed by caspase 8 (Ac-IETD-CHO) and caspase 9 (Ac-LEHE-CHO) inhibitors but not by the metalloproteinase inhibitors GM6001 and TAPI-0. Microparticle counts in culture supernatants were higher during etoposide-induced apoptosis. The ROCK1 inhibitor, Y27632, suppressed blebbing formation and microparticle release. Moreover, flow cytometry and immunoblotting revealed CD31 and CD47 in the microparticles. These results indicate that CD31 and CD47 were released by the apoptotic Jurkat cells into the culture supernatant in microparticles, but not in soluble forms, resulting in decreased levels on the apoptotic cell surface.

  11. SU-E-T-379: Concave Approximations of Target Volume Dose Metrics for Intensity- Modulated Radiotherapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y; Chen, Y; Wickerhauser, M [Washington University in St. Louis, St. Louis, MO (United States); Deasy, J [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: The widely used treatment plan metric Dx (mimimum dose to the hottest x% by volume of the target volume) is simple to interpret and use, but is computationally poorly behaved (non-convex), this impedes its use in computationally efficient intensity-modulated radiotherapy (IMRT) treatment planning algorithms. We therefore searched for surrogate metrics that are concave, computationally efficient, and accurately correlated to Dx values in IMRT treatment plans. Methods: To find concave surrogates of D95—and more generally, Dx values with variable x values—we tested equations containing one or two generalized equivalent uniform dose (gEUD) functions. Fits were obtained by varying gEUD ‘a’ parameter values, as well as the linear equation coefficients. Fitting was performed using a dataset of dose-volume histograms from 498 de-identified head and neck IMRT treatment plans. Fit characteristics were tested using a crossvalidation process. Reported root-mean-square error values were averaged over the cross-validation shuffles. Results: As expected, the two-gEUD formula provided a superior fit, compared to the single-gEUD formula. The best approximation uses two gEUD terms: 16.25 x gEUD[a=0.45] – 15.30 x gEUD[a=1.75] – 0.69. The average root-mean-square error on repeated (70/30) cross validation was 0.94 Gy. In addition, a formula was found that reasonably approximates Dx for x between 80% and 96%. Conclusion: A simple concave function using two gEUD terms was found that correlates well with PTV D95s for these head and neck treatment plans. More generally, a formula was found that represents well the Dx for x values from 80% to 96%, thus providing a computationally efficient formula for use in treatment planning optimization. The formula may need to be adjusted for other institutions with different treatment planning protocols. We conclude that the strategy of replacing Dx values with gEUD-based formulas is promising.

  12. Preliminary Requirement of Hot Pool Free Surface Level from PGSFR Reactor Head

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Gyeonghoi; Joo, Hyeongkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The sensitivity study on structural integrity evaluations are carried out to make a decision of a hot pool free surface location from the reactor head for a preliminary designed reactor enclosure system. To do this, the thermal stress evaluations for a reactor vessel are carried out for a steady state normal operating condition with detailed heat transfer analyses through the reactor enclosure system. From these results, the preliminary design requirement of a hot pool free surface location from the reactor head is established to be 2.0m. From the sensitivity studies on the structural integrity evaluations for a steady state condition, the preliminary distance from the hot pool free surface to the reactor head is determined to be 2.0m same as a conceptual design. More detailed structural analyses for a reactor enclosure system will be carried out as a PGSFR structural design goes forward in detail.

  13. 1.34μm Nd:YVO4 high efficiency laser end-pumped by diode-laser of flat-concave cavity type

    Institute of Scientific and Technical Information of China (English)

    Shang Lian-Ju; Ning Ji-Ping

    2005-01-01

    The parameters of 1.34μm Nd:YVO4 laser end-pumped with flat-concave cavity are theoretically analysed. The analysis in this paper may be helpful to the designing of kindred lasers. The operation of 1.34μm Nd:YVO4 laser end-pumped by a diode-laser with flat-concave cavity is achieved. The output power of 3.51W at 1.34μm and optical to optical conversion efficiency of 39.0% are obtained at the pump power of 9.0W.

  14. Potential dose distributions at proposed surface radioactvity clearance levels resulting from occupational scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Kamboj, S.; Yu, C.; Rabovsky, J. (Environmental Science Division); (USDOE)

    2011-08-02

    The purpose of this report is to evaluate the potential dose distribution resulting from surface radioactivity, using occupational radiation exposure scenarios. The surface radioactivity clearance values considered in this analysis may ultimately replace those currently specified in the U.S. Department of Energy (DOE) requirements and guidance for radiological protection of workers, the public and the environment. The surface contamination values apply to radioactive contamination deposited on a surface (i.e., not incorporated into the interior of the material). For these calculations, the dose coefficients for intake of radionuclides were taken from ICRP Publication 68 (ICRP 1994), and external exposure dose coefficients were taken from the compact disc (CD) that accompanied Federal Guidance Report (FGR) 13 (Eckerman et al. 1999). The ICRP Publication 68 dose coefficients were based on ICRP Publication 60 (ICRP 1990) and were used specifically for worker dose calculations. The calculated dose in this analysis is the 'effective dose' (ED), rather than the 'effective dose equivalent' (EDE).

  15. The SMAP level 4 surface and root zone soil moisture data assimilation product

    Science.gov (United States)

    The NASA Soil Moisture Active Passive (SMAP) mission is scheduled for launch in January 2015 and will provide L-band radar and radiometer observations that are sensitive to surface soil moisture (in the top few centimeters of the soil column). For several of the key applications targeted by SMAP, ho...

  16. High levels of surface differential rotation on the young G0 dwarf HD 171488

    NARCIS (Netherlands)

    Jeffers, S.V.; Donati, J.F.

    2008-01-01

    We present high-resolution images of the young, rapidly rotating G0 dwarf HD 171488, using both Stokes I and Stokes V data. The observations were secured with the MuSiCoS spectropolarimeter at Telescope Bernard Lyot from 2005 May 31 to June 10. The photospheric surface brightness distributions show

  17. Statistical analysis of global surface air temperature and sea level using cointegration methods

    DEFF Research Database (Denmark)

    Schmith, Torben; Johansen, Søren; Thejll, Peter

    Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to physically-based models being unable to simulate observed sea level trends, semi-empirical models have been applied as an alternative for projecting...

  18. Monitoring sea level and sea surface temperature trends from ERS satellites

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Knudsen, Per; Beckley, B.

    2002-01-01

    over this period. In the Indian Ocean and particularly the Pacific Ocean the trends in both sea level and temperature are still dominated by the large changes associated with the El Nino Southern Oscillation. In terms of contribution to the total global sea level change, the contribution of the central...

  19. Extraction of a strongly focusing He+ beam from three-stage concave electrodes for alpha particle measurement system in ITER.

    Science.gov (United States)

    Kobuchi, T; Sasao, M; Kisaki, M; Tsumori, K; Tanaka, N; Okamoto, A; Kitajima, S; Kaneko, O; Shinto, K; Wada, M

    2012-02-01

    A strongly focusing He(+) ion beam source equipped with concave multi-aperture electrodes was developed for production of He(-) through a charge exchange cell. The beam was extracted at a voltage less than 20 kV from 301 apertures distributed in an area of 100 mm φ, and focused at 750 mm distance. The beam current and the beam size of 2 A and 20 mm in diameter, respectively, were achieved with an arc power less than 10 kW. The optimum perveance was obtained at 0.02 A∕kV(1.5) at the beam energy less than 20 keV which is suitable for the conversion to He(-) in an alkali vapor cell.

  20. Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine ligands

    Directory of Open Access Journals (Sweden)

    Rainer Hovorka

    2014-02-01

    Full Text Available Two new 9,9’-spirobifluorene-based bis(4-pyridines were synthesised in enantiopure and one also in racemic form. These ligands act as concave templates and form metallosupramolecular [(dppp2M2L2] rhombi with cis-protected [(dpppPd]2+ and [(dpppPt]2+ ions. The self-assembly process of the racemic ligand preferably occurs in a narcissistic self-recognising manner. Hence, a mixture of all three possible stereoisomers [(dppp2M2{(R-L}2](OTf4, [(dppp2M2{(S-L}2](OTf4, and [(dppp2M2{(R-L}{(S-L}](OTf4 was obtained in an approximate 1.5:1.5:1 ratio which corresponds to an amplification of the homochiral assemblies by a factor of approximately three as evidenced by NMR spectroscopy and mass spectrometry. The racemic homochiral assemblies could also be characterised by single crystal X-ray diffraction.

  1. Numerically Studying the Effect of Stiffening Rings on Reducing the Thickness of Torospherical Heads under Pressure on Their Concave Side

    Directory of Open Access Journals (Sweden)

    Sa'id Golabi

    2008-01-01

    Full Text Available The high thickness of heads used in pressure vessels is always one of the main concerns of designers and manufacturers. A thorough study has been conducted on all types of heads including torospherical heads, with external and internal pressure to reduce their thickness using stiffening rings by finite element technique. Here the result of analysis on heads with pressure on their concave side is presented. The results include a method for determining the dimensions of the most suitable ring and its location on heads from one hand and its effect on reduction of the head thickness from the other hand. The result of analysis showed that using suitable stiffening ring may reduce up to 30% of the head thickness.

  2. High-resolution X-ray focusing concave (elliptical) curved crystal spectrograph for laser-produced plasma

    Institute of Scientific and Technical Information of China (English)

    Shali xiao(肖沙里); Yingjun Pan(潘英俊); Xianxin Zhong(钟先信); Xiancai Xiong(熊先才); Guohong Yang(杨国洪); Zongli Liu(刘宗礼); Yongkun Ding(丁永坤)

    2004-01-01

    The X-ray spectrum emitted from laser-produced plasma contains plentiful information.X-ray spectrometer is a powerful tool for plasma diagnosis and studying the information and evolution of the plasma.X-ray concave(elliptical)curved crystals analyzer was designed and manufactured to investigate the properties of laser-produced plasma.The experiment was carried out on Mianyang Xingguang-ⅡFacility and aimed at investigating the characteristics of a high density iron plasma.Experimental results using KAP,LIF,PET,and MICA curved crystal analyzers are described,and the spectra of Au,Ti laser-produced plasma are shown.The focusing crystal analyzer clearly gave an increase in sensitivity over a flat crystal.

  3. Robust Segmentation of Voxel Shapes using Medial Surfaces

    NARCIS (Netherlands)

    Reniers, Dennie; Telea, Alexandru

    2008-01-01

    We present a new patch-type segmentation method for 3D voxel shapes based on the medial surface, also called surface skeleton. The boundaries of the simplified fore- and background skeletons map one-to-one to increasingly fuzzy, soft convex, respectively concave, edges of the shape. Using this prope

  4. Microbiological levels of randomly selected food contact surfaces in hotels located in Spain during 2007-2009.

    Science.gov (United States)

    Doménech-Sánchez, Antonio; Laso, Elena; Pérez, María José; Berrocal, Clara Isabel

    2011-09-01

    The aim of this study was to survey the microbial levels of food contact surfaces in hotels. Microbiological levels of 4611 surfaces (chopping machines, kitchenware, knives, worktops, and cutting boards) from 280 different facilities in Spain were determined in a 3-year period. The contact-plate technique was used throughout the survey. Overall, the mean of the log of total aerobic count cm(-2) was 0.62, better than those reported for child-care and assisted living facilities. Significant differences were detected among different types of surfaces, time of sampling, season, and year. The majority (74%) of food contact surfaces sampled in Spanish hotels was within the recommended standard of <1.3 log CFU cm(-2), and differences depend on several factors. Our results set a representative picture of the actual situation in our resorts and establish the basis for the development of educational programs to improve food handlers' knowledge of foodborne diseases and their transmission via food contact surfaces.

  5. Theoretical Calculation of a Focused Acoustic Field from a Linear Phased Array on a Concave Cylindrical Transducer

    Institute of Scientific and Technical Information of China (English)

    YU Li-Li; SHOU Wen-De; HUI Chun

    2011-01-01

    A new linear phased array on a concave cylindrical transducer is designed for meeting the specific requirements of applications for interstitial thermal ablation. Using the array, a focal line can be generated rapidly and the focal position can be adjusted in the proper range without the use of complex mechanical structures. The focused acoustic Reid distributions in the axial, radial and azimuthal directions of the transducer are investigated theoretically by numerical simulation. Effects of the focal distance, steering angle, element arc-width, arc-space between adjacent elements and number of elements on the acoustic field are also thoroughly studied. Many important results are obtained.%A new linear phased array on a concave cylindrical transducer is designed for meeting the specific requirements of applications for interstitial thermal ablation.Using the array,a focal line can be generated rapidly and the focal position can be adjusted in the proper range without the use of complex mechanical structures.The focused acoustic field distributions in the axial,radial and azimuthal directions of the transducer are investigated theoretically by numerical simulation.Effects of the focai distance,steering angle,element arc-width,arc-space between adjacent elements and number of elements on the acoustic field are also thoroughly studied.Many important results are obtained.Interstitial thermal ablation is a promising technique for treating tumors that are both nonresectable and difficult to reach with extracorporeal therapy.[1,2] In this method,a small transducer is brought into contact with the targeted region and emits a highintensity acoustic wave;the interaction between the wave and the tissues causes a strong heating effect that induces the thermal coagulation and necrosis of the target.[3

  6. Origin of surface electron accumulation and fermi level pinning in low energy ion induced InN/GaN heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Monu; Shibin Krishna, T.C. [Surface Physics and Nanostructure Heteroepitaxy Laboratory, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Academy of Scientific and Innovative Research (AcSIR), CSIR-NPL Campus, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Kumar, Mukesh [Surface Physics and Nanostructure Heteroepitaxy Laboratory, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Gupta, Govind, E-mail: govind@nplindia.org [Surface Physics and Nanostructure Heteroepitaxy Laboratory, Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Academy of Scientific and Innovative Research (AcSIR), CSIR-NPL Campus, Dr. K.S. Krishnan Marg, New Delhi 110012 (India)

    2015-07-15

    InN/GaN heterostructure was fabricated via reactive low energetic Nitrogen ion (LENI at 300 eV) bombardment at lower substrate temperature (350 °C). X-Ray Photoemission spectroscopic (XPS) and Atomic Force Microscopic (AFM) measurements were performed to analyse the electronic structure, surface chemistry, band alignment, and the morphology of the grown heterostructure. XPS analysis revealed the evolution of InN structure with nitridation time, surface electron accumulation, fermi level pinning and the band offset of the grown InN/GaN hetero structure. The valence band and conduction band offsets (VBO & CBO) were calculated to be 0.49 ± 0.19 eV and 2.21 ± 0.1 eV and divulged the formation of a type-I heterojunction. A Fermi Level (FL) pinning of 1.5 ± 0.1 eV above the conduction band minima was perceived and indicated towards strong downward band bending. The analysis of the VB spectra suggested that surface electron accumulation occurred due to the presence of metallic In-adlayer on the surface which resulted in FL pinning and the corresponding downward band bending. Atomic Force Microscopy analysis divulged the formation of smooth surface with granular structure. It was also observed that the growth parameters (e.g. substrate temperature) strongly influence the aforementioned surface and interfacial properties. - Highlights: • A novel technique for the growth of ultrathin InN/GaN heterostructure is reported. • Surface Electron Accumulation and FL Pinning were observed. • A strong downward band bending was also observed in the InN/GaN heterostructure.

  7. Determining the level of heavy metal pollution in surface sediments of the Gulf of Chabahar

    OpenAIRE

    Bazzi, A

    2015-01-01

    Background & Objectives: This paper, discussed the concentrations of heavy metals such as cadmium, copper, lead, zinc, nickel, chromium, iron, and magnesium in surface sediments of the Gulf of Chabahar. Materials & Methods: Samples of coastal sediment and shallow waters were collected from five different stations in summer and winter, 2013. Results: The research found that the concentrations of heavy metals in sediments is more than water, although the concentrations of metals in sedime...

  8. Chemical bonding of water to metal surfaces studied with core-level spectroscopies

    DEFF Research Database (Denmark)

    Schiros, T.; Andersson, Klas Jerker; Pettersson, L.G.M.;

    2010-01-01

    and the interaction between the water monolayer and the surface. By combining synchrotron radiation-based X-ray photoelectron spectroscopy (XPS). X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) techniques with density functional theory (DFT) computational methods we obtain element......-specific information on the partial local density of states, local atomic structure, geometrical parameters and molecular orientation, allowing general principles for water-metal interaction to be derived....

  9. Pore-level numerical analysis of the infrared surface temperature of metallic foam

    Science.gov (United States)

    Li, Yang; Xia, Xin-Lin; Sun, Chuang; Tan, He-Ping; Wang, Jing

    2017-10-01

    Open-cell metallic foams are increasingly used in various thermal systems. The temperature distributions are significant for the comprehensive understanding of these foam-based engineering applications. This study aims to numerically investigate the modeling of the infrared surface temperature (IRST) of open-cell metallic foam measured by an infrared camera placed above the sample. Two typical approaches based on Backward Monte Carlo simulation are developed to estimate the IRSTs: the first one, discrete-scale approach (DSA), uses a realistic discrete representation of the foam structure obtained from a computed tomography reconstruction while the second one, continuous-scale approach (CSA), assumes that the foam sample behaves like a continuous homogeneous semi-transparent medium. The radiative properties employed in CSA are directly determined by a ray-tracing process inside the discrete foam representation. The IRSTs for different material properties (material emissivity, specularity parameter) are computed by the two approaches. The results show that local IRSTs can vary according to the local compositions of the foam surface (void and solid). The temperature difference between void and solid areas is gradually attenuated with increasing material emissivity. In addition, the annular void space near to the foam surface behaves like a black cavity for thermal radiation, which is ensued by copious neighboring skeletons. For most of the cases studied, the mean IRSTs computed by the DSA and CSA are close to each other, except when the material emissivity is highly weakened and the sample temperature is extremely high.

  10. Concentration level and geographical distribution of nitrobenzene in Chinese surface waters

    Institute of Scientific and Technical Information of China (English)

    GAO Jijun; LIU Linghua; LIU Xiaoru; ZHOU Huaidong; WANG Zijian; HUANG Shengbiao

    2008-01-01

    Nitrobenzene was reported to occur at relatively high concentrations in some Chinese surface water and to cause an environmental pollution event in 2005. In order to map the distribution of nitrobenzene in the Chinese surface water throughout China, surface water samples were collected from over 600 sites in the 7 major watersheds and three drainage areas. The samples were analyzed for concentration of nitrobenzene. Overall, nitrobenzene was more frequently detected at higher concentrations in the rivers of North China, including Songhuajiang River, Liaohe River, Haihe River, Yellow River, Huaihe River and Northwest drainage area rivers, compared with those in the rivers of South China, including Yangtze river, Pearl river, Southeast drainage area rivers and Southwest drainage rivers. The detection rate of nitrobenzene was the 83.2 % for all the samples, with a mean value of 18.1 ng/L and a range of < 0.3-8,450.0 ng/L. The highest mean concentration of nitrobenzene was observed in the Yellow River, followed by Huaihe River . The results of this investigation indicated that nitrobenzene should be of particular concern in China and its ecological and health risk should be assessed.

  11. Probabilistic assessment of surface level seismic hazard in India using topographic gradient as a proxy for site condition

    Institute of Scientific and Technical Information of China (English)

    T.G. Sitharam; Sreevalsa Kolathayar; Naveen James

    2015-01-01

    This paper presents spatial variation of seismic hazard at the surface level for India, covering 6e38? N and 68e98? E. The most recent knowledge on seismic activity in the region has been used to evaluate the hazard incorporating uncertainties associated with the seismicity parameters using different modeling methodologies. Three types of seismic source models, viz. linear sources, gridded seismicity model and areal sources, were considered to model the seismic sources and different sets of ground motion pre-diction equations were used for different tectonic provinces to characterize the attenuation properties. The hazard estimation at bedrock level has been carried out using probabilistic approach and the results obtained from various methodologies were combined in a logic tree framework. The seismic site char-acterization of India was done using topographic slope map derived from Digital Elevation Model data. This paper presents estimation of the hazard at surface level, using appropriate site amplification factors corresponding to various site classes based on VS30 values derived from the topographic gradient. Spatial variation of surface level peak horizontal acceleration (PHA) for return periods of 475 years and 2475 years are presented as contour maps.

  12. Probabilistic assessment of surface level seismic hazard in India using topographic gradient as a proxy for site condition

    Directory of Open Access Journals (Sweden)

    T.G. Sitharam

    2015-11-01

    Full Text Available This paper presents spatial variation of seismic hazard at the surface level for India, covering 6–38° N and 68–98° E. The most recent knowledge on seismic activity in the region has been used to evaluate the hazard incorporating uncertainties associated with the seismicity parameters using different modeling methodologies. Three types of seismic source models, viz. linear sources, gridded seismicity model and areal sources, were considered to model the seismic sources and different sets of ground motion prediction equations were used for different tectonic provinces to characterize the attenuation properties. The hazard estimation at bedrock level has been carried out using probabilistic approach and the results obtained from various methodologies were combined in a logic tree framework. The seismic site characterization of India was done using topographic slope map derived from Digital Elevation Model data. This paper presents estimation of the hazard at surface level, using appropriate site amplification factors corresponding to various site classes based on VS30 values derived from the topographic gradient. Spatial variation of surface level peak horizontal acceleration (PHA for return periods of 475 years and 2475 years are presented as contour maps.

  13. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite produced by NAVO (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  14. GHRSST Level 2P Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-18 satellite produced by NAVO (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in...

  15. GHRSST Level 2P Atlantic Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset for the Atlantic Ocean and nearby regions based on multi-channel sea surface...

  16. GHRSST Level 2P Atlantic Regional Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-16 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset for the Atlantic Ocean and nearby regions based on multi-channel sea surface...

  17. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-17 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset based on multi-channel sea surface temperature (SST) retrievals from the...

  18. GHRSST Level 2P Global Bulk Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-16 satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 2P Group for High Resolution Sea Surface Temperature (GHRSST) dataset based on multi-channel sea surface temperature (SST) retrievals from the...

  19. GHRSST Level 4 AVHRR_OI Global Blended Sea Surface Temperature Analysis (GDS version 2) from NCEI (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.25 degree grid at the NOAA...

  20. Modulation of single quantum dot energy levels by a surface-acoustic-wave

    Science.gov (United States)

    Gell, J. R.; Ward, M. B.; Young, R. J.; Stevenson, R. M.; Atkinson, P.; Anderson, D.; Jones, G. A. C.; Ritchie, D. A.; Shields, A. J.

    2008-08-01

    This letter presents an experimental investigation into the effect of a surface-acoustic-wave (SAW) on the emission of a single InAs quantum dot. The SAW causes the energy of the transitions within the dot to oscillate at the frequency of the SAW, producing a characteristic broadening of the emission lines in their time-averaged spectra. This periodic tuning of the transition energy is used as a method to regulate the output of a device containing a single quantum dot and we study the system as a high-frequency periodic source of single photons.

  1. Dexamethasone reduces cell surface levels of CD11b on human eosinophils

    Directory of Open Access Journals (Sweden)

    A. M. Das

    1997-01-01

    Full Text Available Overnight incubation of human eosinophils (Eøs with the glucocorticoid hormone dexamethasone (DEX; 0.1 μM resulted in lower expression of the CD11b, but not CD49d, antigen on their plasma membrane, as assessed by flow cytometry. DEX produced a consistent inhibitory effect (ranging from 16% to 20% when tested at a concentration of 0.1 μM. Eø stimulation with 100 ng/ml eotaxin produced an increase in CD11b (+26%, but not CD11c, levels and concomitantly a reduction (–25% on CD62L expression. The inhibition exerted by DEX upon CD11b levels was also evident following eotaxin upregulation, with a degree of inhibition similar to that seen on basal levels. These data highlight a novel mechanism of action by which glucocorticoid hormones may be effective in reducing Eø accumulation during allergic inflammation in man.

  2. Reconstruction of the surface-layer vertical structure from measurements of wind, temperature and humidity at two levels

    Science.gov (United States)

    Musson-Genon, Luc; Dupont, Eric; Wendum, Denis

    2007-08-01

    We present a comparison between several methods used to reconstruct fluxes and vertical profiles of wind, temperature and humidity from measurements at two levels in the atmospheric surface layer for different practical applications. An analytical method and an iterative method are tested by evaluating the quality of estimations of surface fluxes from detailed field measurements obtained during a campaign on the site of Lannemezan in the south-west of France. The iterative method yields better results, but the analytical one can give results of the same level of accuracy provided that specific constants in its formulation are modified. Then these techniques are applied to wind and temperature reconstruction for an experiment dedicated to wind power estimates over flat terrain. If turbulent fluxes are not needed, a simple power law appears to be sufficient, as the method based on Monin-Obukhov theory does not improve the accuracy of the vertical profile reconstruction.

  3. Effect of carbamide peroxide and hydrogen peroxide on the surface morphology and zinc oxide levels of IRM fillings.

    Science.gov (United States)

    Rostein, I; Cohenca, N; Mor, C; Moshonov, J; Stabholz, A

    1995-12-01

    The effect of 10% carbamide peroxide or 10% hydrogen peroxide on the surface morphology and zinc oxide levels of IRM fillings was tested. Ninety IRM samples were treated with either 10% carbamide peroxide, 10% hydrogen peroxide or phosphate buffer which served as control. Treatment consisted of placing the samples in a dry incubator at 37 degrees C for 1, 3 or 7 days. At each time point, the samples were removed from the test solutions, dried and prepared for surface scanning electron microscopy and energy dispersive spectrometric analysis. After 3 days, 10% carbamide peroxide significantly reduced the zinc oxide levels as compared to the 10% hydrogen peroxide group (IRM fillings, but their modes of action differed.

  4. Global Sea Surface Temperature and Sea Level Rise Estimation with Optimal Historical Time Lag Data

    Directory of Open Access Journals (Sweden)

    Mustafa M. Aral

    2016-11-01

    Full Text Available Prediction of global temperatures and sea level rise (SLR is important for sustainable development planning of coastal regions of the world and the health and safety of communities living in these regions. In this study, climate change effects on sea level rise is investigated using a dynamic system model (DSM with time lag on historical input data. A time-invariant (TI-DSM and time-variant dynamic system model (TV-DSM with time lag is developed to predict global temperatures and SLR in the 21st century. The proposed model is an extension of the DSM developed by the authors. The proposed model includes the effect of temperature and sea level states of several previous years on the current temperature and sea level over stationary and also moving scale time periods. The optimal time lag period used in the model is determined by minimizing a synthetic performance index comprised of the root mean square error and coefficient of determination which is a measure for the reliability of the predictions. Historical records of global temperature and sea level from 1880 to 2001 are used to calibrate the model. The optimal time lag is determined to be eight years, based on the performance measures. The calibrated model was then used to predict the global temperature and sea levels in the 21st century using a fixed time lag period and moving scale time lag periods. To evaluate the adverse effect of greenhouse gas emissions on SLR, the proposed model was also uncoupled to project the SLR based on global temperatures that are obtained from the Intergovernmental Panel on Climate Change (IPCC emission scenarios. The projected SLR estimates for the 21st century are presented comparatively with the predictions made in previous studies.

  5. Improving the spectral resolution of flat-field concave grating miniature spectrometers by dividing a wide spectral band into two narrow ones.

    Science.gov (United States)

    Zhou, Qian; Pang, Jinchao; Li, Xinghui; Ni, Kai; Tian, Rui

    2015-11-10

    In this study, a new flat-field concave grating miniature spectrometer is proposed with improved resolution across a wide spectral band. A mirror is added to a conventional concave grating spectrometer and placed near the existing detector array, allowing a wide spectral band to be divided into two adjacent subspectral bands. One of these bands is directly detected by the detector, and the other is indirectly analyzed by the same detector after being reflected by the mirror. These two subspectral bands share the same entrance slit, concave grating, and detector, which allows for a compact size, while maintaining an improved spectral resolution across the entire spectral band. The positions of the mirror and other parameters of the spectrometer are designed by a computer procedure and the optical design software ZEMAX. Simulation results show that the resolution of this kind of flat-field concave grating miniature spectrometer is better than 1.6 nm across a spectral band of 700 nm. Experiments based on three laser sources reveal that the measured resolutions are comparable to the simulated ones, with a maximum relative error between them of less than 19%.

  6. Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction

    Science.gov (United States)

    Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

    2015-12-01

    Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611} high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H2PtCl6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells.

  7. Correlation between the Sensitivity to TRAIL and the Expression Level of DR5 on the Surface of Tumor Cells

    Institute of Scientific and Technical Information of China (English)

    Yuanfang Ma; Jun Zhang; Yueping Zhao

    2005-01-01

    OBJECTIVE To investigate the correlation between the sensitivity to the tumor necrosis factor- related apoptosis inducing ligand (TRAIL) and the level of expression of the death receptor 5 (DR5) on the surface of tumor cells.METHODS Anti-DR5 mAbs were used to directly detect the level of expression of DR5 on the surface of tumor cells. Using a TRAIL apoptosis kit and flow cytometry, the sensitivity of the tumor cells to TRAIL-induced apoptosis was determined and the correlation between DR5 expression and sensitivity to TRAIL analyzed.RESULTS The expression level of DR5 on the surface of different tumor cells was as follows: 97.9% in U937 cells, 95.1% in Jurkat cells, 93.8% in SW480 cells, 86.2% in HCT116 cells, 64.2% in HL-60 cells, 46.6% in Hela cells and 13.1% in K562 cells. The TRAIL-induced apoptotic rate was 72.6% in U937 cells, 85.2% in Jurkat cells, 78.6% in SW480 cells, 70.2% in HCT116 cells,60.1% in HL-60 cells, 45.4% in Hela cells and 12.3% in K562 cells. Statistical analysis showed there was a significant positive correlation (r=0.997, P<0.001) between DR5 expression and sensitivity to TRAIL.CONCLUSION The sensitivity of tumor cells to TRAIL is related to the level of expression of DR5 on the surface of tumor cells. These results confirm the importance of DR5 expression for induction of apoptosis by TRAIL.

  8. Can a global model reproduce observed trends in summertime surface ozone levels?

    Directory of Open Access Journals (Sweden)

    S. Koumoutsaris

    2012-01-01

    Full Text Available Quantifying trends in surface ozone concentrations are critical for assessing pollution control strategies. Here we use observations and results from a global chemical transport model to examine the trends (1991–2005 in daily maximum 8-hour average concentrations in summertime surface ozone at rural sites in Europe and the United States. We find a decrease in observed ozone concentrations at the high end of the probability distribution at many of the sites in both regions. The model attributes these trends to a decrease in local anthropogenic ozone precursors, although simulated decreasing trends are overestimated in comparison with observed ones. The low end of observed distribution show small upward trends over Europe and the western US and downward trends in Eastern US. The model cannot reproduce these observed trends, especially over Europe and the western US. In particular, simulated changes between the low and high end of the distributions in these two regions are not significant. Sensitivity simulations indicate that emissions from far away source regions do not affect significantly ozone trends at both ends of the distribution. This is in contrast with previously available results, which indicated that increasing ozone trends at the low percentiles may reflect an increase in ozone background associated with increasing remote sources of ozone precursors. Possible reasons for discrepancies between observed and simulated trends are discussed.

  9. Estimating seepage flux from ephemeral stream channels using surface water and groundwater level data

    Science.gov (United States)

    Noorduijn, Saskia L.; Shanafield, Margaret; Trigg, Mark A.; Harrington, Glenn A.; Cook, Peter G.; Peeters, L.

    2014-02-01

    Seepage flux from ephemeral streams can be an important component of the water balance in arid and semiarid regions. An emerging technique for quantifying this flux involves the measurement and simulation of a flood wave as it moves along an initially dry channel. This study investigates the usefulness of including surface water and groundwater data to improve model calibration when using this technique. We trialed this approach using a controlled flow event along a 1387 m reach of artificial stream channel. Observations were then simulated using a numerical model that combines the diffusion-wave approximation of the Saint-Vénant equations for streamflow routing, with Philip's infiltration equation and the groundwater flow equation. Model estimates of seepage flux for the upstream segments of the study reach, where streambed hydraulic conductivities were approximately 101 m d-1, were on the order of 10-4 m3 d-1 m-2. In the downstream segments, streambed hydraulic conductivities were generally much lower but highly variable (˜10-3 to 10-7 m d-1). A Latin Hypercube Monte Carlo sensitivity analysis showed that the flood front timing, surface water stage, groundwater heads, and the predicted streamflow seepage were most influenced by specific yield. Furthermore, inclusion of groundwater data resulted in a higher estimate of total seepage estimates than if the flood front timing were used alone.

  10. Pesticide levels in ground and surface waters of Primavera do Leste Region, Mato Grosso, Brazil.

    Science.gov (United States)

    Dores, Eliana F G C; Carbo, Leandro; Ribeiro, Maria L; De-Lamonica-Freire, Ermelinda M

    2008-08-01

    Residues of the herbicides simazine, metribuzin, metolachlor, trifluralin, atrazine, and two metabolites of atrazine, deisopropylatrazine (DIA) and deethylatrazine (DEA), are surveyed in the surface and groundwater of the Primavera do Leste region, Mato Grosso, Brazil during September and December 1998 and April 1999. Different water source sampling stations of groundwater (irrigation water well, drinking water well, and water hole) and surface water (dam and river) are set up based on agricultural land use. A solid-phase extraction procedure followed by gas chromatography-nitrogen-phosphorus detection is used for the determination of these compounds. All compounds are detected at least once in water samples. A temporal trend of pesticide contamination is observed, with the highest contamination frequency occurring in December during the main application season. Metribuzin shows the highest individual detection frequencies throughout the monitoring period, followed by metolachlor, simazine, and DEA. The maximum mean concentrations of pesticides in this study are in the range from 0.14 to 1.7 microg/L. We deduct that the contamination of water resources is predominantly caused by non-point pollution of pesticides used in intensive cash-crop cultures of the Cerrado area. Therefore, a continuous monitoring of pesticide concentrations in water resources of this tropical region is necessary to detect the longer term contamination trends and developing health risks.

  11. Optimum crushing level of blasted rock at the Prokop'evsk surface coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Gemba, V.I.; Starkov, V.L.; Ustyuzhanin, V.S.

    1987-06-01

    Explains that improving the quality of rock crushing using blasting energy increases the efficiency of excavators and other mining equipment, reduces the energy required for scooping and loading tasks and hence reduces the cost of excavating and transporting rock. Investigations performed in surface mines in the Southern Urals and the Kuzbass coal sections showed that changing the mean linear dimensions of the lumps of blasted rock from 0.2 to 0.8 m increased the power consumption of a EhKG-4,6 excavator from 0.12 to 0.3 kWh/m/sup 3/ and that of loading from 0.1 to 1.56 kWh/m/sup 3/. Uses actual values for the efficiency and costs of blasting, excavation and transporting operations (presented in tabular form) as the basis for a comparative evaluation with the aim of determining how to achieve maximum cost-efficiency and, taking all factors into account, calculates that for the Prokop'evsk surface mine the optimum lump size is 0.4 m.

  12. Created mangrove wetlands store belowground carbon and surface elevation change enables them to adjust to sea-level rise

    Science.gov (United States)

    Krauss, Ken W.; Cormier, Nicole; Osland, Michael J.; Kirwan, Matthew L.; Stagg, Camille L.; Nestlerode, Janet A.; Russell, Marc J.; From, Andrew; Spivak, Amanda C.; Dantin, Darrin D.; Harvey, James E.; Almario, Alejandro E.

    2017-01-01

    Mangrove wetlands provide ecosystem services for millions of people, most prominently by providing storm protection, food and fodder. Mangrove wetlands are also valuable ecosystems for promoting carbon (C) sequestration and storage. However, loss of mangrove wetlands and these ecosystem services are a global concern, prompting the restoration and creation of mangrove wetlands as a potential solution. Here, we investigate soil surface elevation change, and its components, in created mangrove wetlands over a 25 year developmental gradient. All created mangrove wetlands were exceeding current relative sea-level rise rates (2.6 mm yr−1), with surface elevation change of 4.2–11.0 mm yr−1 compared with 1.5–7.2 mm yr−1 for nearby reference mangroves. While mangrove wetlands store C persistently in roots/soils, storage capacity is most valuable if maintained with future sea-level rise. Through empirical modeling, we discovered that properly designed creation projects may not only yield enhanced C storage, but also can facilitate wetland persistence perennially under current rates of sea-level rise and, for most sites, for over a century with projected medium accelerations in sea-level rise (IPCC RCP 6.0). Only the fastest projected accelerations in sea-level rise (IPCC RCP 8.5) led to widespread submergence and potential loss of stored C for created mangrove wetlands before 2100.

  13. Measurements of Location-Dependent Nitric Oxide Levels on Skin Surface in relation to Acupuncture Point

    Directory of Open Access Journals (Sweden)

    Yejin Ha

    2012-01-01

    Full Text Available Location-dependent skin surface’s partial nitric oxide pressure (pNO is studied using highly sensitive amperometric NO microsensor with a small sensing area (diameter  = 76 μm. The pNO level of LI4 (Hegu acupuncture point is measured and compared with the pNO level of nonacupuncture point. In addition, the mapping of pNO is carried out over the left wrist skin area one- as well as two-dimensionally. Statistically higher pNO levels near the position of acupuncture points than non-acupuncture points are observed consistently, implying tight relationship between the level of NO release of skin and acupuncture points. The amperometric planar NO microsensor successfully monitors the heterogeneity of skin pNO distribution in high spatial resolution due to its advantageous features such as high sensitivity and small sensing dimension. The current study suggests the direct connection between NO and acupuncture points and possibly provides beneficial information to understand physiological roles and basis of the acupuncture points.

  14. Optical properties and defect levels in a surface layer found on CuInSe{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Abulfotuh, F.; Wangensteen, T.; Ahrenkiel, R.; Kazmerski, L.L. [National Renewable Energy Lab., Golden, CO (United States)

    1996-09-01

    In this paper the authors have used photoluminescence (PL) and wavelength scanning ellipsometry (WSE) to clarify the relationship among the electro-optical properties of copper indium diselenide (CIS) thin films, the type and origin of dominant defect states, and device performance. The PL study has revealed several shallow acceptor and donor levels dominating the semiconductor. PL emission from points at different depths from the surface of the CIS sample has been obtained by changing the angle of incidence of the excitation laser beam. The resulting data were used to determine the dominant defect states as a function of composition gradient at the surface of the chalcopyrite compound. The significance of this type of measurement is that it allowed the detection of a very thin layer with a larger bandgap (1.15--1.26 eV) than the CIS present on the surface of the CIS thin films. The presence of this layer has been correlated by several groups to improve the CIS cell performance. An important need that results from detecting this layer on the surface of the CIS semiconductor is the determination of its thickness and optical constants (n, k) as a function of wavelength. The thickness of this surface layer is about 500 {angstrom}.

  15. Optical properties and defect levels in a surface layer found on CuInSe{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Abulfotuh, F.; Wangensteen, T.; Ahrenkiel, R.; Kazmerski, L.L. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    In this paper the authors have used photoluminescence (PL) and wavelength scanning ellipsometry (WSE) to clarify the relationship among the electro-optical properties of copper indium diselenide (CIS) thin films, the type and origin of dominant defect states, and device performance. The PL study has revealed several shallow acceptor and donor levels dominating the semiconductor. PL emission from points at different depths from the surface of the CIS sample has been obtained by changing the angle of incidence of the excitation laser beam. The resulting data were used to determine the dominant defect states as a function of composition gradient at the surface of the chalcopyrite compound. The significance of this type of measurement is that it allowed the detection of a very thin layer with a larger bandgap (1.15-1.26 eV) than the CIS present on the surface of the CIS thin films. The presence of this layer has been correlated by several groups to improvement of the CIS cell performance. An important need that results from detecting this layer on the surface of the CIS semiconductor is the determination of its thickness and optical constants (n, k) as a function of wavelength. The thickness of this surface layer is about 500 {Angstrom}.

  16. Global and local aspects of the surface potential landscape for energy level alignment at organic-ZnO interfaces

    Science.gov (United States)

    Stähler, Julia; Rinke, Patrick

    2017-03-01

    Hybrid systems of organic and inorganic semiconductors are a promising route for the development of novel opto-electronic and light-harvesting devices. A key ingredient for achieving a superior functionality by means of a hybrid system is the right relative position of energy levels at the interfaces of the two material classes. In this Perspective, we address the sensitivity of the potential energy landscape at various ZnO surfaces, a key ingredient for interfacial energy level alignment, by combining one- and two-photon photoelectron spectroscopy with density-functional theory calculations (DFT). We show that even very large work function changes (>2.5 eV) do not necessarily have to be accompanied by surface band bending in ZnO. Band bending - if it does occur - may be localized to few Å or extend over hundreds of nanometers with very different results for the surface work function and energy level alignment. Managing the delicate balance of different interface manipulation mechanisms in organic-inorganic hybrid systems will be a major challenge towards future applications.

  17. FRACTIONAL-STEP FINITE ELEMENT METHOD FOR CALCULATION OF 3-D FREE SURFACE PROBLEM USING LEVEL SET METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lan-hao; LI Tong-chun; WANG Ling; HERREROS M. I.; PASTOR M.

    2006-01-01

    A two-step Taylor-Galerkin fractional-step finite element method, which is of second order accuracy in space and time, was proposed for the three-dimensional free surface problem. With this method, the intermediate velocity was explicitly obtained by neglecting pressure gradient term, and then the velocity was corrected by adding the effects of pressure once the pressure field had been obtained from the pressure Poisson equation. The level set approach was applied to track implicitly the free surface. In order to track the free surface, the transport equation of the level set function was solved at each time step and the level set function is reinitialized through iteration to maintain it as a distance function. The governing equations of the system were discretized by the two- step Taylor-Galerkin method, which is of high-order accuracy and easy to be used. The validity and reliability of this method in this article were proved by two numerical examples.

  18. Termination-specific study of oxygen vacancy transition levels on SrTiO3(001) surfaces by scanning tunneling spectroscopy

    Science.gov (United States)

    Sitaputra, Wattaka; Sivadas, Nikhil; Skowronski, Marek; Xiao, Di; Feenstra, Randall

    2015-03-01

    We have studied the surface electronic structure of oxygen vacancies on SrTiO3(001) surfaces using scanning tunneling spectroscopy and DFT calculations with local spin density approximation (LSDA +U). With high dynamic range measurements, a mid-gap level associated with the surface oxygen vacancies was observed for SrO-terminated surfaces. TiO2-terminated surfaces, on the other hand, did not exhibit observable mid-gap states (this lack of signal is believed to be due to the nature of defect wavefunction involved, as well as possibly involving transport limitations in the STS measurements). Both vacuum-cleaved and MBE-grown surface have been studied. For the former, the Fermi level is pinned near mid-gap owing to disorder-induced surface states. The amount of surface disorder can be controlled in the case of epitaxially grown surfaces. Rougher MBE-grown surfaces were found to exhibit similar spectral characteristics to the cleaved surfaces, while a shift of the Fermi level toward the conduction band was observed for flatter grown surfaces. Notably, with a decreasing number of disorder-induced surface states, the Fermi level is found to be pinned within the observed band of oxygen vacancy levels. This research was supported by AFOSR Grant No. FA9550-12-1-0479, and it used resources of the National Energy Research Scientific Computing Center, supported by the Office of Science, US Department of Energy under Contract No. DEAC02-05CH11231.

  19. Characterization of Drain Surface Water: Environmental Profile, Degradation Level and Geo-statistic Monitoring

    Directory of Open Access Journals (Sweden)

    Muhammad Waseem Mumtaz

    2015-12-01

    Full Text Available The physico-chemical characterization of the surface water. Samples was carried out collected from nine sampling points of drain passing by the territory of Hafizabad city, Punjab, Pakistan. The water of drain is used by farmers for irrigation purposes in nearby agricultural fields. Twenty water quality parameters were evaluated in three turns and the results obtained were compared with the National Environmental Quality Standards (NEQS municipal and industrial effluents prescribed limits. The highly significant difference (p0.05 was noted for temperature, pH, electrical conductivity, hardness, calcium, sodium, chemical oxygen demand and chloride among water samples from different sampling points. Furthermore, the experimental results of different water quality parameters studied at nine sampling points of the drain were used and interpolated in ArcGIS 9.3 environment system using kriging techniques to obtain calculated values for the remaining locations of the Drain.

  20. Invariant Surface EMG Feature Against Varying Contraction Level for Myoelectric Control Based on Muscle Coordination.

    Science.gov (United States)

    He, Jiayuan; Zhang, Dingguo; Sheng, Xinjun; Li, Shunchong; Zhu, Xiangyang

    2015-05-01

    Variations in muscle contraction effort have a substantial impact on performance of pattern recognition based myoelectric control. Though incorporating changes into training phase could decrease the effect, the training time would be increased and the clinical viability would be limited. The modulation of force relies on the coordination of multiple muscles, which provides a possibility to classify motions with different forces without adding extra training samples. This study explores the property of muscle coordination in the frequency domain and found that the orientation of muscle activation pattern vector of the frequency band is similar for the same motion with different force levels. Two novel features based on discrete Fourier transform and muscle coordination were proposed subsequently, and the classification accuracy was increased by around 11% compared to the traditional time domain feature sets when classifying nine classes of motions with three different force levels. Further analysis found that both features decreased the difference among different forces of the same motion ) and maintained the distance among different motions p > 0.1). This study also provided a potential way for simultaneous classification of hand motions and forces without training at all force levels.

  1. Happiness and loss aversion : is utility concave or convex in relative income?

    NARCIS (Netherlands)

    Woltjer, G.B.; Vendrik, M.

    2007-01-01

    Abstract A central finding in happiness research is that a person's life satisfaction depends on the level of her income relative to the average income in her social reference group. This dependence of life satisfaction on relative income can be related to the reference dependence of the value

  2. Revisiting Snodgrass and Vanderwart's object pictorial set: the role of surface detail in basic-level object recognition.

    Science.gov (United States)

    Rossion, Bruno; Pourtois, Gilles

    2004-01-01

    Theories of object recognition differ to the extent that they consider object representations as being mediated only by the shape of the object, or shape and surface details, if surface details are part of the representation. In particular, it has been suggested that color information may be helpful at recognizing objects only in very special cases, but not during basic-level object recognition in good viewing conditions. In this study, we collected normative data (naming agreement, familiarity, complexity, and imagery judgments) for Snodgrass and Vanderwart's object database of 260 black-and-white line drawings, and then compared the data to exactly the same shapes but with added gray-level texture and surface details (set 2), and color (set 3). Naming latencies were also recorded. Whereas the addition of texture and shading without color only slightly improved naming agreement scores for the objects, the addition of color information unambiguously improved naming accuracy and speeded correct response times. As shown in previous studies, the advantage provided by color was larger for objects with a diagnostic color, and structurally similar shapes, such as fruits and vegetables, but was also observed for man-made objects with and without a single diagnostic color. These observations show that basic-level 'everyday' object recognition in normal conditions is facilitated by the presence of color information, and support a 'shape + surface' model of object recognition, for which color is an integral part of the object representation. In addition, the new stimuli (sets 2 and 3) and the corresponding normative data provide valuable materials for a wide range of experimental and clinical studies of object recognition.

  3. Land Surface Water Mapping Using Multi-Scale Level Sets and a Visual Saliency Model from SAR Images

    Directory of Open Access Journals (Sweden)

    Chuan Xu

    2016-05-01

    Full Text Available Land surface water mapping is one of the most basic classification tasks to distinguish water bodies from dry land surfaces. In this paper, a water mapping method was proposed based on multi-scale level sets and a visual saliency model (MLSVS, to overcome the lack of an operational solution for automatically, rapidly and reliably extracting water from large-area and fine spatial resolution Synthetic Aperture Radar (SAR images. This paper has two main contributions, as follows: (1 The method integrated the advantages of both level sets and the visual saliency model. First, the visual saliency map was applied to detect the suspected water regions (SWR, and then the level set method only needed to be applied to the SWR regions to accurately extract the water bodies, thereby yielding a simultaneous reduction in time cost and increase in accuracy; (2 In order to make the classical Itti model more suitable for extracting water in SAR imagery, an improved texture weighted with the Itti model (TW-Itti is employed to detect those suspected water regions, which take into account texture features generated by the Gray Level Co-occurrence Matrix (GLCM algorithm, Furthermore, a novel calculation method for center-surround differences was merged into this model. The proposed method was tested on both Radarsat-2 and TerraSAR-X images, and experiments demonstrated the effectiveness of the proposed method, the overall accuracy of water mapping is 98.48% and the Kappa coefficient is 0.856.

  4. The Sentinel-3 Surface Topography Mission (S-3 STM): Level 2 SAR Ocean Retracker

    Science.gov (United States)

    Dinardo, S.; Lucas, B.; Benveniste, J.

    2015-12-01

    The SRAL Radar Altimeter, on board of the ESA Mission Sentinel-3 (S-3), has the capacity to operate either in the Pulse-Limited Mode (also known as LRM) or in the novel Synthetic Aperture Radar (SAR) mode. Thanks to the initial results from SAR Altimetry obtained exploiting CryoSat-2 data, lately the interest by the scientific community in this new technology has significantly increased and consequently the definition of accurate processing methodologies (along with validation strategies) has now assumed a capital importance. In this paper, we present the algorithm proposed to retrieve from S-3 STM SAR return waveforms the standard ocean geophysical parameters (ocean topography, wave height and sigma nought) and the validation results that have been so far achieved exploiting the CryoSat-2 data as well as the simulated data. The inversion method (retracking) to extract from the return waveform the geophysical information is a curve best-fitting scheme based on the bounded Levenberg-Marquardt Least-Squares Estimation Method (LEVMAR-LSE). The S-3 STM SAR Ocean retracking algorithm adopts, as return waveform’s model, the “SAMOSA” model [Ray et al, 2014], named after the R&D project SAMOSA (led by Satoc and funded by ESA), in which it has been initially developed. The SAMOSA model is a physically-based model that offers a complete description of a SAR Altimeter return waveform from ocean surface, expressed in the form of maps of reflected power in Delay-Doppler space (also known as stack) or expressed as multilooked echoes. SAMOSA is able to account for an elliptical antenna pattern, mispointing errors in roll and yaw, surface scattering pattern, non-linear ocean wave statistics and spherical Earth surface effects. In spite of its truly comprehensive character, the SAMOSA model comes with a compact analytical formulation expressed in term of Modified Bessel functions. The specifications of the retracking algorithm have been gathered in a technical document (DPM

  5. Surface plasmon resonance sensor for phosmet of agricultural products at the ppt detection level.

    Science.gov (United States)

    Song, Yang; Liu, Ming; Wang, Shuo

    2013-03-20

    A surface plasmon resonance (SPR) immunoassay using a PH-BSA immobilized sensor chip was developed to measure phosmet in food samples. The in-competitive inhibition assay showed highly sensitive and good specificity of the cross-reactivity with analogue structure pesticides. The biosensor exhibited a linear detection range from 8.0 to 60.0 ng/L of phosmet with a lower detection limit of 1.6 ng/L (S/N = 3). The sensitivity obtained with the present SPR affinity biosensor was significantly higher than most of the sensors reported with different measurement methodologies for phosmet. A recovery test of pesticide quantification in peaches, apples, cabbages, and rapes was also studied. Good recoveries (86.4-102.8%) and coefficients of variation (CVs) (5.1-12.6%) were obtained in all cases. The SPR biosensor assay method was compared with cd-ELISA in terms of analysis time, antibody dosage, recoveries, precision, detection limit, pretreatment, and testing costs, and clear advantages could be seen over the traditional ELISA-based detection systems. The developed SPR method was suitable for the rapid quantitative or qualitative determination of phosmet in agricultural products.

  6. BOREAS RSS-14 Level -3 Gridded Radiometer and Satellite Surface Radiation Images

    Science.gov (United States)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Hodges, Gary; Smith, Eric A.

    2000-01-01

    The BOREAS RSS-14 team collected and processed GOES-7 and -8 images of the BOREAS region as part of its effort to characterize the incoming, reflected, and emitted radiation at regional scales. This data set contains surface radiation parameters, such as net radiation and net solar radiation, that have been interpolated from GOES-7 images and AMS data onto the standard BOREAS mapping grid at a resolution of 5 km N-S and E-W. While some parameters are taken directly from the AMS data set, others have been corrected according to calibrations carried out during IFC-2 in 1994. The corrected values as well as the uncorrected values are included. For example, two values of net radiation are provided: an uncorrected value (Rn), and a value that has been corrected according to the calibrations (Rn-COR). The data are provided in binary image format data files. Some of the data files on the BOREAS CD-ROMs have been compressed using the Gzip program. See section 8.2 for details. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  7. TanDEM-X the Earth surface observation project from space level - basis and mission status

    Directory of Open Access Journals (Sweden)

    Jerzy Wiśniowski

    2015-03-01

    Full Text Available TanDEM-X is DLR (Deutsches Zentrum für Luft- und Raumfahrt the Earth surface observation project using high-resolution SAR interferometry. It opens a new era in space borne radar remote sensing. The system is based on two satellites: TerraSAR-X (TSX and TanDEM-X (TDX flying on the very close, strictly controlled orbits. This paper gives an overview of the radar technology and overview of the TanDEM-X mission concept which is based on several innovative technologies. The primary objective of the mission is to deliver a global digital elevation model (DEM with an unprecedented accuracy, which is equal to or surpass the HRTI-3 specifications (12 m posting, relative height accuracy ±2 m for slope < 20% and ±4 m for slope > 20% [8]. Beyond that, TanDEM-X provides a highly reconfigurable platform for the demonstration of new radar imaging techniques and applications.[b]Keywords[/b]: remote sensing, Bistatic SAR, digital elevation model (DEM, Helix formation, SAR interferomery, HRTI-3, synchronization

  8. Dynamics and kinematics of ant locomotion: do wood ants climb on level surfaces?

    Science.gov (United States)

    Reinhardt, Lars; Weihmann, Tom; Blickhan, Reinhard

    2009-08-01

    The biomechanics of running in small animals have remained poorly characterized because of the difficulty of recording three-dimensional ground reaction forces. Available techniques limit investigations to animals with a body mass above 1 g. Here we present, for the first time, single-leg ground reaction forces of ants (body mass 10 mg), measured with a custom-built miniature force plate. We investigated forces and high-speed kinematics for straight level runs (average speed: 8.4 cm s(-1)) of Formica polyctena workers. The major finding was that the time course of ground reaction forces strongly differed from previous observations of larger insects. Maximum vertical force was reached during the first third of the tripod contact phase. During this period the body was decelerated predominantly by the front legs. Subsequently, the front legs pulled and accelerated the body. This 'climbing' type of stride may be useful on the bumpy and unstable substrates that the animals face in their natural habitats, and may therefore also occur on level ground. Propulsive forces were generated predominantly by the front and hind legs. Dragging of the gaster on the substrate resulted in a breaking momentum, which was compensated by the legs. Future investigations will reveal, whether the identified pattern is due to specialization.

  9. A new accurate ground-state potential energy surface of ethylene and predictions for rotational and vibrational energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, Thibault, E-mail: thibault.delahaye@univ-reims.fr; Rey, Michaël, E-mail: michael.rey@univ-reims.fr; Tyuterev, Vladimir G. [Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, F-51687, Reims Cedex 2 (France); Nikitin, Andrei [Laboratory of Theoretical Spectroscopy, Institute of Atmospheric Optics, Russian Academy of Sciences, 634055 Tomsk, Russia and Quamer, State University of Tomsk (Russian Federation); Szalay, Péter G. [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518 Budapest (Hungary)

    2014-09-14

    In this paper we report a new ground state potential energy surface for ethylene (ethene) C{sub 2}H{sub 4} obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82 542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally computed vibrational levels of the C{sub 2}H{sub 4} molecule was obtained with a RMS(Obs.–Calc.) deviation of 2.7 cm{sup −1} for fundamental bands centers and 5.9 cm{sup −1} for vibrational bands up to 7800 cm{sup −1}. Large scale vibrational and rotational calculations for {sup 12}C{sub 2}H{sub 4}, {sup 13}C{sub 2}H{sub 4}, and {sup 12}C{sub 2}D{sub 4} isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm{sup −1} are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of {sup 13}C{sub 2}H{sub 4} and {sup 12}C{sub 2}D{sub 4} and rovibrational levels of {sup 12}C{sub 2}H{sub 4}.

  10. Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.J. [Colorado School of Mines, Golden, CO (United States); Berry, G.; Rockett, A. [Univ. of Illinois, Urbana-Champaign, IL (United States)] [and others

    1997-04-01

    Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.

  11. Investigation of Surface Pre-Treatment Methods for Wafer-Level Cu-Cu Thermo-Compression Bonding

    Directory of Open Access Journals (Sweden)

    Koki Tanaka

    2016-12-01

    Full Text Available To increase the yield of the wafer-level Cu-Cu thermo-compression bonding method, certain surface pre-treatment methods for Cu are studied which can be exposed to the atmosphere before bonding. To inhibit re-oxidation under atmospheric conditions, the reduced pure Cu surface is treated by H2/Ar plasma, NH3 plasma and thiol solution, respectively, and is covered by Cu hydride, Cu nitride and a self-assembled monolayer (SAM accordingly. A pair of the treated wafers is then bonded by the thermo-compression bonding method, and evaluated by the tensile test. Results show that the bond strengths of the wafers treated by NH3 plasma and SAM are not sufficient due to the remaining surface protection layers such as Cu nitride and SAMs resulting from the pre-treatment. In contrast, the H2/Ar plasma–treated wafer showed the same strength as the one with formic acid vapor treatment, even when exposed to the atmosphere for 30 min. In the thermal desorption spectroscopy (TDS measurement of the H2/Ar plasma–treated Cu sample, the total number of the detected H2 was 3.1 times more than the citric acid–treated one. Results of the TDS measurement indicate that the modified Cu surface is terminated by chemisorbed hydrogen atoms, which leads to high bonding strength.

  12. County-Level Climate Uncertainty for Risk Assessments: Volume 15 Appendix N - Forecast Surface Runoff.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lowry, Thomas Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Shannon M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walker, La Tonya Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Malczynski, Leonard A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

  13. County-Level Climate Uncertainty for Risk Assessments: Volume 14 Appendix M - Historical Surface Runoff.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

    2017-06-01

    This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

  14. Improvement of proteolytic efficiency towards low-level proteins by an antifouling surface of alumina gel in a microchannel.

    Science.gov (United States)

    Liu, Yun; Wang, Huixiang; Liu, Qingping; Qu, Haiyun; Liu, Baohong; Yang, Pengyuan

    2010-11-07

    A microfluidic reactor has been developed for rapid enhancement of protein digestion by constructing an alumina network within a poly(ethylene terephthalate) (PET) microchannel. Trypsin is stably immobilized in a sol-gel network on the PET channel surface after pretreatment, which produces a protein-resistant interface to reduce memory effects, as characterized by X-ray fluorescence spectrometry and electroosmotic flow. The gel-derived network within a microchannel provides a large surface-to-volume ratio stationary phase for highly efficient proteolysis of proteins existing both at a low level and in complex extracts. The maximum reaction rate of the encapsulated trypsin reactor, measured by kinetic analysis, is much faster than in bulk solution. Due to the microscopic confinement effect, high levels of enzyme entrapment and the biocompatible microenvironment provided by the alumina gel network, the low-level proteins can be efficiently digested using such a microreactor within a very short residence time of a few seconds. The on-chip microreactor is further applied to the identification of a mixture of proteins extracted from normal mouse liver cytoplasm sample via integration with 2D-LC-ESI-MS/MS to show its potential application for large-scale protein identification.

  15. Highly Accurate Potential Energy Surface, Dipole Moment Surface, Rovibrational Energy Levels, and Infrared Line List for (32)S(16)O2 up to 8000 cm(exp -1)

    Science.gov (United States)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2014-01-01

    A purely ab initio potential energy surface (PES) was refined with selected (32)S(16)O2 HITRAN data. Compared to HITRAN, the root-mean-squares error (RMS) error for all J=0-80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm(exp -1). Combined with a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296K and covers up to 8,000 cm(exp -1). Compared to the HITRAN and CDMS databases, the intensity agreement for most vibrational bands is better than 85-90%. Our predictions for (34)S(16)O2 band origins, higher energy (32)S(16)O2 band origins and missing (32)S(16)O2 IR bands have been verified by most recent experiments and available HITRAN data. We conclude that the Ames-1 PES is able to predict (32/34)S(16)O2 band origins below 5500 cm(exp -1) with 0.01-0.03 cm(exp -1) uncertainties, and the Ames-296K line list provides continuous, reliable and accurate IR simulations. The Ka-dependence of both line position and line intensity errors is discussed. The line list will greatly facilitate SO2 IR spectral experimental analysis, as well as elimination of SO2 lines in high-resolution astronomical observations.

  16. High level theoretical study of binding and of the potential energy surface in benzene-hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Coletti, Cecilia, E-mail: ccoletti@unich.it [Dipartimento di Scienze del Farmaco, Universita ' G. d' Annunzio' Chieti-Pescara, Via dei Vestini 31, 66100 Chieti (Italy); Re, Nazzareno [Dipartimento di Scienze del Farmaco, Universita ' G. d' Annunzio' Chieti-Pescara, Via dei Vestini 31, 66100 Chieti (Italy)

    2012-04-04

    Graphical abstract: In-plane minimum geometries for benzene-H{sup -} non-covalent adducts: linear adduct (left) with the hydride ion hydrogen bonded to one aromatic hydrogen; bifurcated adduct (right), with the hydride ion hydrogen bonded to two adjacent aromatic hydrogens. Highlights: Black-Right-Pointing-Pointer Theoretical study on covalent and non-covalent binding in benzene-hydride. Black-Right-Pointing-Pointer Two non-covalent stable adducts were characterized in the in-plane geometry. Black-Right-Pointing-Pointer Significant sections of the potential energy surface were determined. Black-Right-Pointing-Pointer Formation of a very stable C{sub 6}H{sub 7}{sup -} anion upon covalent binding to carbon. - Abstract: High level ab initio calculations were performed on the interaction of the hydride anion with benzene, a system of potential interest for modelling the interactions occurring in hydrogen rich planetary atmospheres. We investigated both non-covalent and covalent binding, exploring the complete basis set limit using highly correlated MP2 and CCSD(T) levels of theory. Two non-covalent minima on the potential energy surface have been characterized, and found to correspond to moderately strong hydrogen bonding interactions. To gain further insight on the nature of binding, the total interaction energy was decomposed into its physically meaningful components and selected sections of the potential energy surface were calculated. Moreover, we found that H{sup -} can easily covalently bind to one of the carbon atoms of benzene to form a stable C{sub 6}H{sub 7}{sup -} anion, a global minimum on the potential energy surface, characterized by a puckered geometry, with a carbon atom bending out of the benzene plane. A slightly less stable planar C{sub 6}H{sub 7}{sup -} structure was also identified, corresponding to the transition state for the flipping motion of the puckered species.

  17. Process Control Plan for Tank 241-SY-101 Surface Level Rise Remediation

    Energy Technology Data Exchange (ETDEWEB)

    ESTEY, S.D.

    1999-09-28

    The tank 241-SY-101 transfer system was conceived and designed to address the immediate needs presented by rapidly changing waste conditions in tank 241-SY-101. Within the last year or so, the waste in this tank has exhibited unexpected behavior (Rassat et al. 1999) in the form of rapidly increasing crust growth. This growth has been brought about by a rapidly increasing rate of gas entrapment within the crust. It has been conceived that the lack of crust agitation beginning upon the advent of mixer pump operations may have set-up a more consolidated, gas impermeable barrier when compared to a crust regularly broken up by the prior buoyant displacement events within the tank. As a result, a series of level-growth remediation activities have been developed for tank 241-SY-101. The initial activities are also known as near-term crust mitigation. The first activity of near-term mitigation is to perform the small transfer of convective waste from tank 241-SY-101 into tank 241-SY-102. A 100 kgal transfer represents about a 10% volume reduction allowing a 10% water in-tank dilution. Current thinking holds that this should be enough to dissolve nitrite solids in the crust and perhaps largely eliminate gas retention problem in the crust (Raymond 1999).

  18. Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

    Science.gov (United States)

    Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

    2017-08-01

    Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

  19. International Workshop on “Generalized Concavity, Fractional Programming and Economic Applications”

    CERN Document Server

    Castagnoli, Erio; Martein, Laura; Mazzoleni, Piera; Schaible, Siegfried

    1990-01-01

    Generalizations of convex functions have been used in a variety of fields such as economics. business administration. engineering. statistics and applied sciences.· In 1949 de Finetti introduced one of the fundamental of generalized convex functions characterized by convex level sets which are now known as quasiconvex functions. Since then numerous types of generalized convex functions have been defined in accordance with the need of particular applications.· In each case such functions preserve soine of the valuable properties of a convex function. In addition to generalized convex functions this volume deals with fractional programs. These are constrained optimization problems which in the objective function involve one or several ratios. Such functions are often generalized convex. Fractional programs arise in management science. economics and numerical mathematics for example. In order to promote the circulation and development of research in this field. an international workshop on "Generalized Concavi...

  20. Influence of SHI upon nanohole free volume and micro scale level surface modifications of polyethyleneterephthalate polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com; Singh, Paramjit

    2015-05-15

    Highlights: • Ion irradiation of PET polymer (used for gas separation applications) for structural, optical, chemical, surface and free volume studies. • The amorphization and decrease of the band gap energy after ions irradiation. • The value of R increased after ion irradiation due to the expansion of the polymeric chains and increase of the size of cavities. • Increase in the surface roughness creating the site of track formation. - Abstract: Topographic micro scale and in-depth nano scale level modifications of polymeric materials play an important role in engineering their physical and chemical properties. Polyethylene terephthalate (PET) is an important class of semi-crystalline polymers used for gas separation properties. The gas diffusion and permeability parameters are directly related to the free volume fractions and the hole distributions. The controlled and precise ion beam irradiation can be used to induce surface and in-depth modifications in the properties of the polymers which help in modifying free volume holes and their distributions. In the present study, the investigation of free volume (nano scale level) and surface (micro scale level) properties of PET polymeric thin films after SHI treatment were employed by means of positron annihilation lifetime spectroscopy (PALS) and atomic force microscopy (AFM), respectively. The PET thin films were irradiated by 50 MeV lithium ions as a function of ion fluence. The value of hole radius (R) and intensity (I{sub 3}) of o-Ps were observed to be increased after ion beam treatment. The further analyses were employed to calculate the free volume and fractional free volume of holes from the obtained values of R and I{sub 3}. The AFM studies reveal the surface modifications of the irradiated polymer films. The structural, optical and chemical properties were investigated by X-ray diffraction (XRD), UV–visible (UV–vis) and Fourier transform infrared (FTIR) spectrophotometry. Different parameters

  1. Establishment and experimental verification of the photoresist model considering interface slip between photoresist and concave spherical substrate

    Directory of Open Access Journals (Sweden)

    S. Yang

    2015-07-01

    Full Text Available A thickness distribution model of photoresist spin-coating on concave spherical substrate (CSS has been developed via both theoretical studies and experimental verification. The stress of photoresist on rotating CSS is analyzed and the boundary conditions of hydrodynamic equation are presented under the non-lubricating condition. Moreover, a multivariable polynomial equation of photoresist-layer thickness distribution is derived by analyzing and deducing the flow equation where the evaporation rate, substrate topography, interface slip between liquid and CSS, and the variation of rotational speed and photoresist parameters are considered in detail. Importantly, the photoresist-layer thickness at various CSS rotational speeds and liquid concentrations can be obtained according to the theoretical equation. The required photoresist viscosity and concentration parameters of different photoresist coating thickness under a certain coating speeds can be also solved through this equation. It is noted that the calculated theoretical values are well consistent with the experimental results which were measured with various CSS rotational speeds and liquid concentrations at steady state. Therefore, both our experimental results and theoretical analysis provide the guidance for photoresist dilution and pave the way for potential improvements and microfabrication applications in the future.

  2. A Linear Programming Approach to Routing Control in Networks of Constrained Nonlinear Positive Systems with Concave Flow Rates

    Science.gov (United States)

    Arneson, Heather M.; Dousse, Nicholas; Langbort, Cedric

    2014-01-01

    We consider control design for positive compartmental systems in which each compartment's outflow rate is described by a concave function of the amount of material in the compartment.We address the problem of determining the routing of material between compartments to satisfy time-varying state constraints while ensuring that material reaches its intended destination over a finite time horizon. We give sufficient conditions for the existence of a time-varying state-dependent routing strategy which ensures that the closed-loop system satisfies basic network properties of positivity, conservation and interconnection while ensuring that capacity constraints are satisfied, when possible, or adjusted if a solution cannot be found. These conditions are formulated as a linear programming problem. Instances of this linear programming problem can be solved iteratively to generate a solution to the finite horizon routing problem. Results are given for the application of this control design method to an example problem. Key words: linear programming; control of networks; positive systems; controller constraints and structure.

  3. The evolution of orientational order in sheared, 2D granular media of convex and concave elongated particles

    Science.gov (United States)

    Marschall, Theodore; Teitel, Stephen

    We simulate granular media consisting of elongated grains in two dimensions with a uniform background shear. We study the orientational distribution and rotation over a wide range of packing fractions, and find that the distribution reaches a stable steady-state under most initial conditions. The nematic director increases with the packing fraction, but the nematic order parameter exhibits non-monotonic behavior, which occurs well below jamming. We observe the evolution of the orientational distribution starting from configurations with the director out of alignment from its steady state orientation, and the evolution of highly ordered initial states. In general, the tumbling motion caused by the background shear causes such systems to reorder into the steady-state, but some dense, highly-ordered configurations maintain their order and exhibit wagging behavior. This can occur both above and below the jamming transition. These results for smooth, convex, spherocylindrical particles are contrasted with those for concave cross-like particles. This work is supported by NSF Grant DMRPD-09-1765.

  4. Process Control Plan for Tank 241-SY-101 Surface Level Rise Remediation

    Energy Technology Data Exchange (ETDEWEB)

    ESTEY, S.D.

    1999-11-01

    The tank 241-SY-101 transfer system was conceived and designed to address the immediate needs presented by rapidly changing waste conditions in tank 241-SY-101. Within approximately the last year, the waste in this tank has exhibited unexpected behavior (Rassat et al. 1999) in the form of rapidly increasing crust growth. This growth has been brought about by a rapidly increasing rate of gas entrapment within the crust. It has been conceived that the lack of crust agitation beginning upon the advent of mixer pump operations may have set-up a more consolidated, gas impermeable barrier when compared to a crust regularly broken up by the prior buoyant displacement events within the tank. The interim goals of the project are to: (1) protect the mixer pump operability (2) begin releasing gas from the crust, and (3) begin dissolving the crust and solids in the slurry layer. The final goals of the project (Final State) are to solve both the level growth and BD-GRE safety issues in this tank by achieving a condition of the waste such that no active measures are required to safely store the waste, i.e., crust and non convective layer are mostly dissolved, and therefore the mixer pump will no longer be needed to prevent BD-GREs in excess of 100% LFL. Transfers (which are designed to create space in the tank) and dilution (which will dissolve the solids) will accomplish this. Dissolution of solids will result in a release of gas retained by those solids and remove that volume of solids as a future retention site.

  5. Discontinuity surfaces and event stratigraphy of Okha Shell Limestone Member: Implications for Holocene sea level changes, western India

    Indian Academy of Sciences (India)

    Uday Bhonde; Bhawanisingh G Desai

    2011-08-01

    The Okha Shell Limestone Member of Chaya Formation is the coarse grained, shell rich deposit commonly recognized as the beach rocks. It has been age bracketed between Late Pleistocene and Holocene. Late Quaternary sea level changes have been studied with beach rocks along the Saurashtra coastal region. The present study has been carried out in the Okhamandal area of the Saurashtra peninsula especially on the Okha Shell Limestone Member as exposed at various locations along the coast from north to south. Temporal and spatial correlations of the observations have revealed three events in the Okha Shell Limestone Member of Chaya Formation that are correlated laterally. The events show depositional breaks represented by discontinuity surfaces, the taphofacies varieties and ichnological variations. The present study in the context of available geochrnological data of the region suggests a prominent depositional break representing low sea level stand (regression) during an Early Holocene during the deposition of Okha Shell Limestone Member.

  6. Time prediction of an onset of shallow landslides based on the monitoring of the groundwater level and the surface displacement at different locations on a sandy model slope

    Science.gov (United States)

    Sasahara, Katsuo

    2016-04-01

    Location of monitoring of the deformation and the groundwater level in a slope is important for time-prediction of an onset of shallow landslides based on the monitoring. The analysis of the monitored data of the surface displacement and the groundwater level at different locations in sandy model slope under artificial rainfall was conducted in this study. The monitored data showed that the surface displacement increased with the increase of the groundwater level significantly. Then the analysis of the monitored data revealed that the relation between the surface displacement and the groundwater level can be modified as hyperbolic curve. The surface displacement grew larger and maximum groundwater level was smaller at farther location from the toe of the slope. Time-prediction of an onset of a landslide based on the monitored data at different location on the slope was proposed as following procedures. (1) To make a regression equation for the relation between the surface displacement and the groundwater level based on the monitored data at any time before the failure, (2) To make a regression equation for the relation between the time and the groundwater level based on the same data with (1), and (3) To incorporate the equation for the relation between the time and the groundwater level into that between the surface displacement and the groundwater level to derive the time - the surface displacement relation. (4) To derive the time - the inverse of the surface displacement velocity from the equation for the time - the surface displacement relation. The equation for the time - the surface displacement and the equation for the time - the inverse of the surface displacement velocity could simulate the actual phenomena of the slope well based on the monitored data at any location on the model slope.

  7. Influence of surface states on deep level transient spectroscopy in AlGaN/GaN heterostructure

    Science.gov (United States)

    Qing, Zhu; Xiao-Hua, Ma; Wei-Wei, Chen; Bin, Hou; Jie-Jie, Zhu; Meng, Zhang; Li-Xiang, Chen; Yan-Rong, Cao; Yue, Hao

    2016-06-01

    Deep level transient spectroscopy (DLTS) as a method to investigate deep traps in AlGaN/GaN heterostructure or high electron mobility transistors (HEMTs) has been widely utilized. The DLTS measurements under different bias conditions are carried out in this paper. Two hole-like traps with active energies of E v + 0.47 eV, and E v + 0.10 eV are observed, which are related to surface states. The electron traps with active energies of E c - 0.56 eV are located in the channel, those with E c - 0.33 eV and E c - 0.88 eV are located in the AlGaN layer. The presence of surface states has a strong influence on the detection of electron traps, especially when the electron traps are low in density. The DLTS signal peak height of the electron trap is reduced and even disappears due to the presence of plentiful surface state. Project supported by the National Key Basic Research Program of China (Grant No. 2011CBA00606), the Program for New Century Excellent Talents in University, China (Grant No. NCET-12-0915), and the National Natural Science Foundation of China (Grant Nos. 61334002 and 61404097).

  8. Tuning the surface Fermi level on p-type gallium nitride nanowires for efficient overall water splitting.

    Science.gov (United States)

    Kibria, M G; Zhao, S; Chowdhury, F A; Wang, Q; Nguyen, H P T; Trudeau, M L; Guo, H; Mi, Z

    2014-04-30

    Solar water splitting is one of the key steps in artificial photosynthesis for future carbon-neutral, storable and sustainable source of energy. Here we show that one of the major obstacles for achieving efficient and stable overall water splitting over the emerging nanostructured photocatalyst is directly related to the uncontrolled surface charge properties. By tuning the Fermi level on the nonpolar surfaces of gallium nitride nanowire arrays, we demonstrate that the quantum efficiency can be enhanced by more than two orders of magnitude. The internal quantum efficiency and activity on p-type gallium nitride nanowires can reach ~51% and ~4.0 mol hydrogen h(-1) g(-1), respectively. The nanowires remain virtually unchanged after over 50,000 μmol gas (hydrogen and oxygen) is produced, which is more than 10,000 times the amount of photocatalyst itself (~4.6 μmol). The essential role of Fermi-level tuning in balancing redox reactions and in enhancing the efficiency and stability is also elucidated.

  9. Effect of wind turbine wakes on cropland surface fluxes in the US Great Plains during a Nocturnal Low Level Jet

    Science.gov (United States)

    Rhodes, M. E.; Aitken, M.; Lundquist, J. K.; Takle, E. S.; Prueger, J. H.

    2010-12-01

    Installation of large scale wind farms is becoming a common operation in the Midwest, and wind farms frequently are situated among fields of agricultural crops. Each wind turbine is known to alter the behavior of the air mass downwind of the rotor; consequently, the rotor wakes alter the local microclimate. Quantification of the effects of wind turbine wakes on local microclimate is required to understand how large-scale wind deployment affects large-scale agriculture. This study examines the potential effect of wind turbine wakes on a corn crop in central Iowa during summer 2010. The field site consisted of one surface flux tower upwind of a row of five modern wind turbine generators, an identical surface flux station downwind of the turbine row, and a ground based LIDAR system downwind of the wind turbines. Each flux tower was instrumented with an array consisting of radiometers, a three-dimensional sonic anemometer, an open cell CO2 analyzer, a cup anemometer and wind vane, temperature and relative humidity sensors, and a tipping bucket. The LIDAR system reliably obtained readings up to 200 m above ground level (AGL), spanning the entire rotor disk (~40 m to 120 m AGL). This presentation examines wake-surface interaction on one particular night, during which the prevailing winds situated the LIDAR directly behind a wind turbine approximately 2 rotor diameters downwind of the turbine tower. As expected preliminary LIDAR results indicate that in the turbine rotor shadow there is a strong deficit of horizontal momentum. Additionally, a strong nocturnal low-level jet occurred above the turbine rotor disk. Wavelet spectral analysis indicates that oscillatory behavior, with frequencies characteristic of wind turbine wakes, is observed in the LIDAR horizontal and vertical winds and in the downwind flux station datastreams. The characterization of wake effects provided by this unique dataset will allow for better parameterization and modeling of wind turbine wake

  10. Decreased blood hepatitis B surface antibody levels linked to e-waste lead exposure in preschool children

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xijin [Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases, Shantou University Medical College, Shantou 515041, Guangdong (China); Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, Guangdong (China); Chen, Xiaojuan; Zhang, Jian [Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases, Shantou University Medical College, Shantou 515041, Guangdong (China); Guo, Pi [Department of Public Health, Shantou University Medical College, Shantou 515041, Guangdong (China); Fu, Tingzao; Dai, Yifeng [Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases, Shantou University Medical College, Shantou 515041, Guangdong (China); Lin, Stanley L. [Department of Pathophysiology and Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, Guangdong (China); Huo, Xia, E-mail: xhuo@stu.edu.cn [Laboratory of Environmental Medicine and Developmental Toxicology, and Guangdong Provincial Key Laboratory of Infectious Diseases, Shantou University Medical College, Shantou 515041, Guangdong (China)

    2015-11-15

    Highlights: • Secondary exploratory analyses displayed a correlation of blood Pb to HBsAb levels. • Generalized linear mixed models were used to analyze two-phase data. • Children from an e-waste area had higher blood Pb levels and lower HBsAb titers. • Nearly 50% of Pb-exposed children fail to develop sufficient HBV immunity. • Different vaccination strategies are required for in e-waste areas. - Abstract: Lead (Pb) is a widespread environmental contaminant that can profoundly affect the immune system in vaccinated children. To explore the association between blood Pb and HBsAb levels in children chronically exposed to Pb, we measured hepatitis B surface antibody (HBsAb) titers, to reflect the immune response in the children of Guiyu, an electronic and electrical waste (e-waste) recycling area well known for environmental Pb contamination. We performed secondary exploratory analyses of blood Pb levels and plasma HBsAb titers in samples, taken in two phases between 2011 and 2012, from 590 children from Guiyu (exposed group) and Haojiang (reference group). Children living in the exposed area had higher blood Pb levels and lower HBsAb titers compared with children from the reference area. At each phase, generalized linear mixed models (GLMMs) showed that HBsAb titers were significantly negatively associated with child blood Pb levels. This work shows that a decreased immune response to hepatitis B vaccine and immune system might have potential harm to children with chronic Pb exposure. Importantly, nearly 50% of chronically exposed children failed to develop sufficient immunity to hepatitis in response to vaccination. Thus different vaccination strategies are needed for children living under conditions of chronic Pb exposure.

  11. Surface elevation change and susceptibility of different mangrove zones to sea-level rise on Pacific high islands of Micronesia

    Science.gov (United States)

    Krauss, K.W.; Cahoon, D.R.; Allen, J.A.; Ewel, K.C.; Lynch, J.C.; Cormier, N.

    2010-01-01

    Mangroves on Pacific high islands offer a number of important ecosystem services to both natural ecological communities and human societies. High islands are subjected to constant erosion over geologic time, which establishes an important source of terrigeneous sediment for nearby marine communities. Many of these sediments are deposited in mangrove forests and offer mangroves a potentially important means for adjusting surface elevation with rising sea level. In this study, we investigated sedimentation and elevation dynamics of mangrove forests in three hydrogeomorphic settings on the islands of Kosrae and Pohnpei, Federated States of Micronesia (FSM). Surface accretion rates ranged from 2.9 to 20.8 mm y-1, and are high for naturally occurring mangroves. Although mangrove forests in Micronesian high islands appear to have a strong capacity to offset elevation losses by way of sedimentation, elevation change over 61/2 years ranged from -3.2 to 4.1 mm y-1, depending on the location. Mangrove surface elevation change also varied by hydrogeomorphic setting and river, and suggested differential, and not uniformly bleak, susceptibilities among Pacific high island mangroves to sea-level rise. Fringe, riverine, and interior settings registered elevation changes of -1.30, 0.46, and 1.56 mm y-1, respectively, with the greatest elevation deficit (-3.2 mm y-1) from a fringe zone on Pohnpei and the highest rate of elevation gain (4.1 mm y-1) from an interior zone on Kosrae. Relative to sea-level rise estimates for FSM (0.8-1.8 mm y-1) and assuming a consistent linear trend in these estimates, soil elevations in mangroves on Kosrae and Pohnpei are experiencing between an annual deficit of 4.95 mm and an annual surplus of 3.28 mm. Although natural disturbances are important in mediating elevation gain in some situations, constant allochthonous sediment deposition probably matters most on these Pacific high islands, and is especially helpful in certain hydrogeomorphic zones

  12. 凹面轮廓凸轮轴成形磨削工艺研究%Research on profile grinding process of concave camshaft

    Institute of Scientific and Technical Information of China (English)

    邓朝晖; 彭欢欢; 万林林; 粟福喻; 黄强

    2014-01-01

    By analyzing the difficulties about the concave contour of camshaft in CNC grinding ,a new grinding process that the concave camshaft is machined by two grinding wheels of different diameters was proposed .A calculation formula about the small wheel radius is given ,and calculating the minimum radius of curvature of the concave contour can help us decide whether it need to switch the grinding wheel .Analyzes in detail the profile grinding process with large size and small size grinding wheels .Be-sides,some experiments are also carried out on the CNC 8325B ultra high speed camshaft grinder .The experimental results show that the concave contour grinding of camshaft can be achieved by this new process and meet the machining accuracy require -ments.%分析带有凹面轮廓的凸轮轴(简称凹面凸轮轴)数控磨削加工难点,提出采用大砂轮与小砂轮复合数控成形磨削凹面凸轮轴新工艺。给出了小砂轮半径的计算公式,通过计算凹面轮廓的最小曲率半径,对比判断是否需要切换砂轮。详细分析了大砂轮与小砂轮复合数控成形磨削凹面凸轮轴新工艺过程,并在CNC8325B全数控凸轮轴超高速复合磨床上进行了高速磨削加工实验,实验结果表明,该工艺方法可以实现凹面凸轮轴轮廓的磨削成形加工,满足了加工精度要求。

  13. About the indentation of a rigid punch with concave base into half plane, taking into account the influence of filler in cavity

    Directory of Open Access Journals (Sweden)

    Amirjanyan H.A.

    2012-03-01

    Full Text Available The contact problem of elasticity theory about the indentation of a rigid punch with concave base into elastic half plane is considered. It is supposed that the cavity between punch and boundary of half plane is filled with air or ideal incompressible liquid. The problem was solved by the method of a discrete singularities. The distribution of contact stresses, the pressure inside cavity and the length of contact area were obtained.

  14. Retrospective study of the bone morphology in the posterior mandibular region. Evaluation of the prevalence and the degree of lingual concavity and their possible complications

    Science.gov (United States)

    Herranz-Aparicio, Judit; Marques, José; Almendros-Marqués, Nieves

    2016-01-01

    Background In order to choose the appropriate implant size and to prevent complications, an oral surgeon must know the size and shape of the mandible. In the posterior mandibular region, a lingual undercut is often found and could represent a difficulty hard to manage if a lingual or buccal perforation occur. A large series of computed tomography (CT) images of the mandibular first molar was evaluated and the bone morphology, the prevalence and the degree of the lingual concavity in the first molar region were studied. Material and Methods One hundred and fifty-one computed tomography (CT) examinations of patients were retrospectively evaluated to determine anatomical variations in bone morphology in the submandibular fossa region. Results A total of 151 subjects were included, consisting of 64 males (M) (42.4%) and 87 females (F) (57.6%). The under-cut type ridge was present in 64.2% of the cases. The concavity angle was 66.6 ± 8.9° (M) and 71.6 ± 8.4° (F) and the linear concavity depth 4.5 ± 2.3 mm (M) and 3.1 ± 1.7 mm (F) (p>0.05). Conclusions Mandibles with any lingual concavity present a potential increased risk of lingual cortical perforation during implant placement surgery. CT imaging allows characterizing the anatomy of the submandibular fossa and provides other important information for the preoperative assessment of the posterior mandible for dental implants placement. Key words:Anatomy, computed tomography, dental implants, intraoperative complications, mandible, panoramic radiography, radiographic examination. PMID:27694785

  15. Kinetics of Hepatitis B Surface Antigen Level in Chronic Hepatitis B Patients who Achieved Hepatitis B Surface Antigen Loss during Pegylated Interferon Alpha-2a Treatment

    Science.gov (United States)

    Li, Ming-Hui; Zhang, Lu; Qu, Xiao-Jing; Lu, Yao; Shen, Ge; Wu, Shu-Ling; Chang, Min; Liu, Ru-Yu; Hu, Lei-Ping; Li, Zhen-Zhen; Hua, Wen-Hao; Song, Shu-Jing; Xie, Yao

    2017-01-01

    Background: Hepatitis B surface antigen (HBsAg) loss/seroconversion is considered to be the ideal endpoint of antiviral therapy and the ultimate treatment goal in chronic hepatitis B (CHB). This study aimed to assess the patterns of HBsAg kinetics in CHB patients who achieved HBsAg loss during the treatment of pegylated interferon (PEG-IFN) α-2a. Methods: A total of 150 patients were enrolled, composing of 83 hepatitis B envelope antigen (HBeAg)-positive and 67 HBeAg-negative patients. Patients were treated with PEG-IFN α-2a180 μg/week until HBsAg loss/seroconversion was achieved, which occurred within 96 weeks. Serum hepatitis B virus deoxyribonucleic acid and serological indicators (HBsAg, anti-HBs, HBeAg, and anti-HBe) were determined before and every 3 months during PEG-IFN α-2a treatment. Biochemical markers and peripheral blood neutrophil and platelet counts were tested every 1–3 months. Results: Baseline HBsAg levels were 2.5 ± 1.3 log IU/ml, and decreased rapidly at 12 and 24 weeks by 48.3% and 88.3%, respectively. The mean time to HBsAg loss was 54.2 ± 30.4 weeks, though most patients needed extended treatment and 30.0% of HBsAg loss occurred during 72–96 weeks. Baseline HBsAg levels were significantly higher in HBeAg-positive patients (2.9 ± 1.1 log IU/ml) compared with HBeAg-negative patients (2.0 ± 1.3 log IU/ml; t = 4.733, P < 0.001), but the HBsAg kinetics were similar. Patients who achieved HBsAg loss within 48 weeks had significantly lower baseline HBsAg levels and had more rapid decline of HBsAg at 12 weeks compared to patients who needed extended treatment to achieve HBsAg loss. Conclusions: Patients with lower baseline HBsAg levels and more rapid decline during early treatment with PEG-IFN are more likely to achieve HBsAg loss during 96 weeks of treatment, and extended therapy longer than 48 weeks may be required to achieve HBsAg loss. PMID:28229987

  16. Mean sea level and surface circulation variability of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetry

    Science.gov (United States)

    Larnicol, Gilles; Le Traon, Pierre-Yves; Ayoub, Nadia; de Mey, Pierre

    1995-12-01

    We describe the circulation and mean sea level variations of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetric data. It is first shown that the response of the Mediterranean Sea to atmospheric pressure forcing is close to an inverse barometer (except at high frequencies) which means that the adjustment is accompanied by a flow through the Straits of Sicily and Gibraltar. We then use TOPEX/POSEIDON to study the mean sea level variations, representing steric effects and integrated large-scale changes of the mass of the Mediterranean Sea. We observe an annual cycle with a fast drop during winter. Steric effects account for about half of the observed variations. The remaining signal is believed to be driven by evaporation minus precipitation (E - P) forcing and internal hydraulic control in the Straits of Gibraltar. Using suboptimal space-time objective analysis, the classic components of the Mediterranean surface circulation are recovered, despite low signal-to-noise ratio (the rms of sea level variability is less than 10 cm). The variable Mediterranean circulation is seen as a complex combination of mesoscale and large-scale variations. The surface circulation is more complex in the eastern basin than in the western basin. In the east it is composed of subbasin-scale gyres, such as the so-called Mersa-Matruh and Shikmona gyres, which do not have an obvious recurrence period. We also observe an intensification of the large-scale cyclonic winter circulation in the western and in the Ionian basins. Several mesoscale structures, such as the Alboran gyres and the Ierepetra gyre, show a clear seasonal cycle, with a maximum in summer. The good qualitative and quantitative agreement of the results with previous data from the Mediterranean illustrates the improved accurary of TOPEX/POSEIDON over its predecessors.

  17. Core-level spectroscopy investigation of the Mo{sub 0.75}Re{sub 0.25}(100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Lyman, P.F.; Zehner, D.M.

    1993-10-01

    Preferential surface segregation in the Mo{sub 0.75}(100) surface region was investigated using high-resolution core-level spectroscopy with synchrotron radiation. The magnitude and direction of the surface core-level shifts observed in this study can be qualitatively understood by comparison to W and Mo core-level shifts. Measured core-level intensities are found to be consistent with the segregation of Mo to the surface of the alloy, with an enrichment of Re in the second layer (as found in previous investigations). It is inferred that both Tc and Os will segregate to the Mo{sub 0.75}Re{sub 0.25}(100) surface.

  18. 太阳能技术在“绿色凹宅”中的应用%Application of Solar Energy Technology in Green Concave House

    Institute of Scientific and Technical Information of China (English)

    莫理莉

    2014-01-01

    This paper introduced the application of solar energy technology in green concave house.The grid-connection photovoltaic power generation was used,which sent the redundant power back to the power network.The photovoltaic solar-thermal integrated solar panels provided the output of electricity and daily at the same time.The smart home system provided the comfortable environment for green concave house.The green concave house is a successful and low energy consumption example,which could provide references for the area of abundant solar energy and dispersal residence.%介绍了太阳能技术在“绿色凹宅”中的应用。采用的并网型太阳能光伏发电系统,当有余电时可回馈电网。铺设的光伏光热一体化太阳能板,在电力输出的同时提供生活热水。智能家居系统给“绿色凹宅”提供舒适的环境。“绿色凹宅”是一个比较成功的环保、低能耗的住宅实例,对太阳能资源丰富而又居住分散的地区有很好的借鉴意义。

  19. The role of surface and subsurface processes in keeping pace with sea level rise in intertidal wetlands of Moreton Bay, Queensland, Australia

    Science.gov (United States)

    Lovelock, Catherine E.; Bennion, Vicki; Grinham, Alistair; Cahoon, Donald R.

    2011-01-01

    Increases in the elevation of the soil surfaces of mangroves and salt marshes are key to the maintenance of these habitats with accelerating sea level rise. Understanding the processes that give rise to increases in soil surface elevation provides science for management of landscapes for sustainable coastal wetlands. Here, we tested whether the soil surface elevation of mangroves and salt marshes in Moreton Bay is keeping up with local rates of sea level rise (2.358 mm y-1) and whether accretion on the soil surface was the most important process for keeping up with sea level rise. We found variability in surface elevation gains, with sandy areas in the eastern bay having the highest surface elevation gains in both mangrove and salt marsh (5.9 and 1.9 mm y-1) whereas in the muddier western bay rates of surface elevation gain were lower (1.4 and -0.3 mm y-1 in mangrove and salt marsh, respectively). Both sides of the bay had similar rates of surface accretion (~7–9 mm y-1 in the mangrove and 1–3 mm y-1 in the salt marsh), but mangrove soils in the western bay were subsiding at a rate of approximately 8 mm y-1, possibly due to compaction of organic sediments. Over the study surface elevation increments were sensitive to position in the intertidal zone (higher when lower in the intertidal) and also to variation in mean sea level (higher at high sea level). Although surface accretion was the most important process for keeping up with sea level rise in the eastern bay, subsidence largely negated gains made through surface accretion in the western bay indicating a high vulnerability to sea level rise in these forests.

  20. One-bit-matching theorem for ICA, convex-concave programming on polyhedral set, and distribution approximation for combinatorics.

    Science.gov (United States)

    Xu, Lei

    2007-02-01

    According to the proof by Liu, Chiu, and Xu (2004) on the so-called one-bit-matching conjecture (Xu, Cheung, and Amari, 1998a), all the sources can be separated as long as there is an one-to-one same-sign correspondence between the kurtosis signs of all source probability density functions (pdf's) and the kurtosis signs of all model pdf's, which is widely believed and implicitly supported by many empirical studies. However, this proof is made only in a weak sense that the conjecture is true when the global optimal solution of an independent component analysis criterion is reached. Thus, it cannot support the successes of many existing iterative algorithms that usually converge at one of the local optimal solutions. This article presents a new mathematical proof that is obtained in a strong sense that the conjecture is also true when any one of local optimal solutions is reached in helping to investigating convex-concave programming on a polyhedral set. Theorems are also provided not only on partial separation of sources when there is a partial matching between the kurtosis signs, but also on an interesting duality of maximization and minimization on source separation. Moreover, corollaries are obtained on an interesting duality, with supergaussian sources separated by maximization and subgaussian sources separated by minimization. Also, a corollary is obtained to confirm the symmetric orthogonalization implementation of the kurtosis extreme approach for separating multiple sources in parallel, which works empirically but lacks mathematical proof. Furthermore, a linkage has been set up to combinatorial optimization from a distribution approximation perspective and a Stiefel manifold perspective, with algorithms that guarantee convergence as well as satisfaction of constraints.

  1. Surface aerosol and rehabilitation properties of ground-level atmosphere in the mountains of the North Caucasus

    Science.gov (United States)

    Reps, Valentina; Efimenko, Natalia; Povolotskaya, Nina; Abramtsova, Anna; Ischenko, Dmitriy; Senik, Irina; Slepikh, Victor

    2017-04-01

    The rehabilitative properties (RP) of ground-level atmosphere (GA) of Russian resorts are considered as natural healing resources and received state legal protection [1]. Due to global urbanization the chemical composition and particle size distribution of the surface aerosol are changing rapidly. However, the influence of surface aerosol on the RP of GA has been insufficiently studied. At the resort region of the North Caucasus complex monitoring (aerosol, trace gases NOx, CO, O3, CH4; periodically - heavy metals) is performed at two high levels (860 masl - a park zone of a large mountain resort, 2070 masl - alpine grassland, the net station). The results of the measurements are used in programs of bioclimatic, landscape and medical monitoring to specify the influence of aerosol on rehabilitation properties of the environment and human adaptative reserves. The aerosol particles of size range 500-1000 nm are used as a marker of the pathogenic effect of aerosol [2]. In the conditions of regional urbanization and complicated mountain atmospheric circulation the influence of aerosol on RP of GA and the variability of heart rhythm with the volunteers at different heights were investigated. At the height of 860 masl (urbanized resort) there have been noticed aerosol variations in the range of 0,04-0,35 particles/cm3 (slightly aerosol polluted), in mountain conditions - background pollution aerosol level. The difference of bioclimatic conditions at the specified high-rise levels has been referred to the category of contrasts. The natural aero ionization ∑(N+)+(N-) varied from 960 ion/cm3 to 1460 ion/cm3 in the resort park (860 m); from 1295 ion/cm3 to 4850 ion/cm3 on the Alpine meadow (2070 m); from 1128 ion/cm3 to 3420 ion/cm3 - on the tested site near the edge of the pinewood (1720 m). In the group of volunteers the trip from low-hill terrain zone (860 m) to the lower zone of highlands (2070 m) caused the activation of neuro and humoral regulation, vegetative and

  2. Estimating Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR

    Directory of Open Access Journals (Sweden)

    X. Fettweis

    2012-08-01

    Full Text Available We report future projections of Surface Mass Balance (SMB over the Greenland ice sheet (GrIS obtained with the regional climate model MAR, forced by the outputs of three CMIP5 General Circulation Models (GCMs when considering two different warming scenarios (RCP 4.5 and RCP 8.5. The GCMs selected in this study have been chosen according to their ability to simulate the current climate over Greenland. Our results indicate that in a warmer climate (i the mass gained due to increased precipitation over GrIS does not compensate the mass lost through increased run-off; (ii the surface melt increases non-linearly with rising temperatures due to the positive feedback between surface albedo and melt, associated with the expansion of bare ice zones which, in addition, decreases the ice sheet refreezing capacity; (iii most of the precipitation is expected to fall as rainfall in summer, which further increases surface melt; (iv no considerable change is expected on the length of the melting season, since heavier winter snowfall dampens the melt increase at the end of spring; (v the increase of meltwater run-off versus temperature anomalies is dependent of the GCM-forced MAR ability to simulate the current climate; (vi the MAR-simulated SMB changes can be approximated using the annual accumulated snowfall and summer 600 hPa temperature increase simulated by the forcing GCMs. In view of the large range in the CMIP5 future projections for the same future scenario, the GCM-based SMB approximations allow us to estimate what future projections are most likely within the CMIP5 multi-model ensemble. In 2100, the ensemble mean projects a sea level rise, resulting from a GrIS SMB decrease, estimated to be +4 ± 2 cm and +9 ± 4 cm for the RCP 4.5 and RCP 8.5 scenarios, respectively. The GrIS SMB should remain positive with respect to RCP 4.5 scenario and becomes negative around 2070 in the case of the RCP 8.5 scenario since a global warming >+3 °C is needed

  3. Power spectral analysis of surface electromyography (EMG) at matched contraction levels of the first dorsal interosseous muscle in stroke survivors.

    Science.gov (United States)

    Li, Xiaoyan; Shin, Henry; Zhou, Ping; Niu, Xun; Liu, Jie; Rymer, William Zev

    2014-05-01

    The objective of this study was to help assess complex neural and muscular changes induced by stroke using power spectral analysis of surface electromyogram (EMG) signals. Fourteen stroke subjects participated in the study. They were instructed to perform isometric voluntary contractions by abducting the index finger. Surface EMG signals were collected from the paretic and contralateral first dorsal interosseous (FDI) muscles with forces ranging from 30% to 70% maximum voluntary contraction (MVC) of the paretic muscle. Power spectral analysis was performed to characterize features of the surface EMG in paretic and contralateral muscles at matched forces. A Linear Mixed Model was applied to identify the spectral changes in the hemiparetic muscle and to examine the relation between spectral parameters and contraction levels. Regression analysis was performed to examine the correlations between spectral characteristics and clinical features. Differences in power spectrum distribution patterns were observed in paretic muscles when compared with their contralateral pairs. Nine subjects showed increased mean power frequency (MPF) in the contralateral side (>15 Hz). No evident spectrum difference was observed in 3 subjects. Only 2 subjects had higher MPF in the paretic muscle than the contralateral muscle. Pooling all subjects' data, there was a significant reduction of MPF in the paretic muscle compared with the contralateral muscle (paretic: 168.7 ± 7.6 Hz, contralateral: 186.1 ± 8.7 Hz, mean ± standard error, F=36.56, ppower spectrum did not confirm a significant correlation between the MPF and contraction force in either hand (F=0.7, p>0.5). There was no correlation between spectrum difference and Fugl-Meyer or Chedoke scores, or ratio of paretic and contralateral MVC (p>0.2). There appears to be complex muscular and neural processes at work post stroke that may impact the surface EMG power spectrum. The majority of the tested stroke subjects had lower MPF in the

  4. Ab initio potential energy surface and vibration-rotation energy levels of silicon dicarbide, SiC2.

    Science.gov (United States)

    Koput, Jacek

    2016-10-01

    The accurate ground-state potential energy surface of silicon dicarbide, SiC2 , has been determined from ab initio calculations using the coupled-cluster approach. Results obtained with the conventional and explicitly correlated coupled-cluster methods were compared. The core-electron correlation, higher-order valence-electron correlation, and scalar relativistic effects were taken into account. The potential energy barrier to the linear SiCC configuration was predicted to be 1782 cm(-1) . The vibration-rotation energy levels of the SiC2 , (29) SiC2 , (30) SiC2 , and SiC(13) C isotopologues were calculated using a variational method. The experimental vibration-rotation energy levels of the main isotopologue were reproduced to high accuracy. In particular, the experimental energy levels of the highly anharmonic vibrational ν3 mode of SiC2 were reproduced to within 6.7 cm(-1) , up to as high as the v3  = 16 state.

  5. Features, events, processes, and safety factor analysis applied to a near-surface low-level radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, M.E.; Dolinar, G.M.; Lange, B.A. [Atomic Energy of Canada Limited, Ontario (Canada)] [and others

    1995-12-31

    An analysis of features, events, processes (FEPs) and other safety factors was applied to AECL`s proposed IRUS (Intrusion Resistant Underground Structure) near-surface LLRW disposal facility. The FEP analysis process which had been developed for and applied to high-level and transuranic disposal concepts was adapted for application to a low-level facility for which significant efforts in developing a safety case had already been made. The starting point for this process was a series of meetings of the project team to identify and briefly describe FEPs or safety factors which they thought should be considered. At this early stage participants were specifically asked not to screen ideas. This initial list was supplemented by selecting FEPs documented in other programs and comments received from an initial regulatory review. The entire list was then sorted by topic and common issues were grouped, and issues were classified in three priority categories and assigned to individuals for resolution. In this paper, the issue identification and resolution process will be described, from the initial description of an issue to its resolution and inclusion in the various levels of the safety case documentation.

  6. Potentiometric Surfaces and Water-Level Trends in the Cockfield and Wilcox Aquifers of Southern and Northeastern Arkansas, 2006

    Science.gov (United States)

    Schrader, T.P.

    2007-01-01

    The Cockfield Formation of Claiborne Group and the Wilcox Group contain aquifers that provide sources of ground water in southern and northeastern Arkansas. In 2000, about 9.9 million gallons per day was withdrawn from the Cockfield Formation of Claiborne Group and about 22.2 million gallons per day was withdrawn from the Wilcox Group. Major withdrawals from the aquifers were for industrial and public water supplies. A study was conducted by the U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey to determine the water level associated with the aquifers in the Cockfield Formation of Claiborne Group and the Wilcox Group in southern and northeastern Arkansas. During February and March 2006, 56 water-level measurements were made in wells completed in the Cockfield aquifer and 59 water-level measurements were made in wells completed in the Wilcox aquifer, 16 in southwestern and 43 in northeastern Arkansas. This report presents the results as potentiometric-surface maps and as long-term water-level hydrographs. The regional direction of ground-water flow in the Cockfield Formation of Claiborne Group generally is towards the east and southeast, away from the outcrop, except in areas of intense ground-water withdrawals, such as western Drew County, southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. There are three cones of depression indicated by relatively low water-level altitudes in southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. The lowest water-level altitude measured was 44 feet above the National Geodetic Vertical Datum of 1929 in Lincoln County; the highest water-level altitude measured was 346 feet above the National Geodetic Vertical Datum of 1929 in Columbia County at the outcrop area. Hydrographs from 40 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to

  7. The Research on Friction Characteristics of Non Smooth Bionic Mesoscopic Surface

    Directory of Open Access Journals (Sweden)

    Su Chunjian

    2014-12-01

    Full Text Available The application of using friction to transmit power and prevent slippage is very widely used, many animals have very strong adhesion climbing ability, and it has important theoretical significance and wide application prospect to research and the prepare bionic surface to increase transmission friction using the bionic technology. In recent years, the research of foot structure of climbing animals shows that their surface morphology has both macro and micro scale features, and only study from the macro to the micro scale surface structure can be better elucidate the mechanism of increasing-friction of climbing animal. This paper will study bionic surface structure on mesoscopic scale from micron to millimeter level, research the influence of foot structure of climbing animal under mesoscopic scale on characteristics of increasing friction using bionic technology, prepare the bionic non-smooth surface of convex or concave using bionic manufacturing technology, establish the friction model of non-smooth surface, investigate the increasing-friction mechanism of the bionic surface morphology on mesoscopic scales, reveals the influence of surface morphology, layout, size and material properties on the friction characteristics, provide the design of bionic friction surface and calculation method of friction coefficient and provide reliable theoretical basis for engineering application.

  8. Soil Moisture Active Passive (SMAP) Mission Level 4 Surface and Root Zone Soil Moisture (L4_SM) Product Specification Document

    Science.gov (United States)

    Reichle, Rolf H.; Ardizzone, Joseph V.; Kim, Gi-Kong; Lucchesi, Robert A.; Smith, Edmond B.; Weiss, Barry H.

    2015-01-01

    This is the Product Specification Document (PSD) for Level 4 Surface and Root Zone Soil Moisture (L4_SM) data for the Science Data System (SDS) of the Soil Moisture Active Passive (SMAP) project. The L4_SM data product provides estimates of land surface conditions based on the assimilation of SMAP observations into a customized version of the NASA Goddard Earth Observing System, Version 5 (GEOS-5) land data assimilation system (LDAS). This document applies to any standard L4_SM data product generated by the SMAP Project. The Soil Moisture Active Passive (SMAP) mission will enhance the accuracy and the resolution of space-based measurements of terrestrial soil moisture and freeze-thaw state. SMAP data products will have a noteworthy impact on multiple relevant and current Earth Science endeavors. These include: Understanding of the processes that link the terrestrial water, the energy and the carbon cycles, Estimations of global water and energy fluxes over the land surfaces, Quantification of the net carbon flux in boreal landscapes Forecast skill of both weather and climate, Predictions and monitoring of natural disasters including floods, landslides and droughts, and Predictions of agricultural productivity. To provide these data, the SMAP mission will deploy a satellite observatory in a near polar, sun synchronous orbit. The observatory will house an L-band radiometer that operates at 1.40 GHz and an L-band radar that operates at 1.26 GHz. The instruments will share a rotating reflector antenna with a 6 meter aperture that scans over a 1000 km swath.

  9. Surface chemistry and Fermi level movement during the self-cleaning of GaAs by trimethyl-aluminum

    Science.gov (United States)

    Tallarida, M.; Adelmann, C.; Delabie, A.; Van Elshocht, S.; Caymax, M.; Schmeisser, D.

    2011-07-01

    The removal of the native oxides from NH4OH-cleaned p-GaAs (100) by exposure to trimethyl-aluminum (TMA) was studied by in situ photoelectron spectroscopy using synchrotron radiation. The reduction of high-valence As- and Ga-oxides occurred through different routes: while As3+ was reduced to As(1±Δ)+ suboxides (with 0 ≤ Δ ≤ 1), Ga3+ was directly removed. The surface Fermi level was shifted by about 100 meV towards the valence band edge upon TMA exposure. This indicates that removing the native oxide of GaAs by TMA is insufficient to create interfaces between GaAs and Al2O3 with defects densities below the 1012 cm-2 range.

  10. The concept of an ACEX® cost-effective first level surface detector trigger in the Pierre Auger Observatory

    Science.gov (United States)

    Szadkowski, Z.

    2005-10-01

    The paper describes the new design of the first level trigger for the surface array in the Pierre Auger Observatory. The previous design was tested in a small test segment called Engineering Array (EA). It confirmed full functionality and reliability of the PLD approach. However, because of the high price of the chips available at that time, a new cost-effective design was developed. Altera® offered cost-effective family, which allows reducing the total budget of the electronics without compromise in the functionality. The here described concept of a splitting of data processing into two sub-channels implemented into the parallel working chips, the chips synchronization and the automatization of internal processing management, together with the fully pipelined AHDL code became the framework for the further implementation in the environmental condition of the Argentinian pampa.

  11. Rapid Detection of Polychlorinated Biphenyls at Trace Levels in Real Environmental Samples by Surface-Enhanced Raman Scattering

    Directory of Open Access Journals (Sweden)

    Zhengjun Zhang

    2011-11-01

    Full Text Available Detection of trace levels of persistent pollutants in the environment is difficult but significant. Organic pollutant homologues, due to their similar physical and chemical properties, are even more difficult to distinguish, especially in trace amounts. We report here a simple method to detect polychlorinated biphenyls (PCBs in soil and distilled spirit samples by the surface-enhanced Raman scattering technique using Ag nanorod arrays as substrates. By this method, polychlorinated biphenyls can be detected to a concentration of 5 μg/g in dry soil samples within 1 minute. Furthermore, based on simulation and understanding of the Raman characteristics of PCBs, we recognized homologues of tetrachlorobiphenyl by using the surface-enhance Raman scattering method even in trace amounts in acetone solutions, and their characteristic Raman peaks still can be distinguished at a concentration of 10-6 mol/L. This study provides a fast, simple and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.

  12. Safety assessment on the human intrusion scenarios of near surface disposal facility for low and very low level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Wook; Park, Jin Baek [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Park, Sang Ho [Chungnam National University, Daejeon (Korea, Republic of)

    2016-03-15

    The second-stage near surface disposal facility for low and very low level radioactive waste's permanent disposal is to be built. During the institutional control period, the inadvertent intrusion of the general public is limited. But after the institutional control period, the access to the general public is not restricted. Therefore human who has purpose of residence and resource exploration can intrude the disposal facility. In this case, radioactive effects to the intruder should be limited within regulatory dose limits. This study conducted the safety assessment of human intrusion on the second-stage surface disposal facility through drilling and post drilling scenario. Results of drilling and post drilling scenario were satisfied with regulatory dose limits. The result showed that post-drilling scenario was more significant than drilling scenario. According to the human intrusion time and behavior after the closure of the facility, dominant radionuclide contributing to the intruder was different. Sensitivity analyses on the parameters about the human behavior were also satisfied with regulatory dose limits. Especially, manual redistribution factor was the most sensitive parameter on exposure dose. A loading plan of spent filter waste and dry active waste was more effective than a loading plan of spent filter waste and other wastes for the radiological point of view. These results can be expected to provide both robustness and defense in depth for the development of safety case further.

  13. Anti-wear properties on 20CrMnTi steel surfaces with biomimetic non-smooth units

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to gain a sufficient wear resistance for applications, the biomimetic non-smooth units in concave were fabricated on the surfaces of 20CrMnTi steel using a biomimetic laser remelting technology. The diameter and distribution of the concaves were optimized using orthogonal experiment. The microstructures of the biomimetic non-smooth units were examined. The anti-wear behaviors were investigated by the rolling wear test with lubricant. The results of wear tests indicated that the biomimetic surfaces exhibit a higher anti-wear ability than the smooth surfaces. The biomimetic surface with concaves of 250 μm in diameter and transverse distance of 270 μm and longitudinal distance of 400 μm exhibits the best anti-wear property. The enhancement of wear resistance can be mainly attributed to the action of biomimetic non-smooth units and the super fined microstructure and hardness in the biomimetic unit zones.

  14. Surface anatomy of major anatomical landmarks of the neck in an adult population: A Ct Evaluation of Vertebral Level.

    Science.gov (United States)

    Badshah, Masroor; Soames, Roger; Ibrahim, Muhammad; Khan, Muhammad Jaffar; Khan, Adnan

    2017-09-01

    To compare the projectional surface anatomy of healthy individuals in an adult population with those with a thyroid mass, using computed tomography (CT). Sixteen slice CT images of 101 individuals were analyzed using a 32-bit Radiant DICOM viewer to establish the relationships among major anatomical landmarks in the neck and their vertebral levels. The structures investigated included: hard palate (HP), hyoid bone (HB) including body and lesser horns, soft palate (SP), thyroid gland (TG) (both superior and inferior poles), thyroid gland anteroposterior (APD) and superoinferior (SID) diameters, thyroid isthmus (TI) superoinferior dimension, epiglottis, vertebral arteries (right and left), and both right and left parotid glands (superior and inferior extents). The vertebral levels noted most frequently were: body of hyoid bone (C4, 42.71%); lesser horns of hyoid bone (C3, 36.46%); thyroid gland superior pole (C6, 31.25%); and thyroid gland inferior pole (T2, 30.2%). TG-ID, TG-APD, and TG-SID were not significantly different between males and females in the healthy group; however, there was a significant gender difference in thyroid gland inferior diameter in the pathology group [males 2.16(±1.16) vs. females 3.37(±1.30), P = 0.01, paired sample t-test]. Further studies are needed to determine whether neck pathology in those with a thyroid mass affects the dimensions of the thyroid gland. Moreover, the surface anatomy of the neck should be revisited using modern imaging techniques to address inconsistencies in anatomy and clinical reference texts. Clin. Anat. 30:781-787, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  15. GHRSST Level 2P Global 1 meter Sea Surface Temperature from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on retrievals from the Visible Infrared Imaging Radiometer Suite (VIIRS)....

  16. GHRSST Level 3C North Atlantic Regional (NAR) subskin Sea Surface Temperature from SNPP/VIIRS (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 3 Collated (L3C) dataset for the North Atlantic Region (NAR) based on retrievals from the...

  17. GHRSST Level 3P Global Subskin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A global Level 3 Group for HIgh Resolution Sea Surface Temperature (GHRSST) dataset from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A platform...

  18. China's air pollution reduction efforts may result in an increase in surface ozone levels in highly polluted areas.

    Science.gov (United States)

    Anger, Annela; Dessens, Olivier; Xi, Fengming; Barker, Terry; Wu, Rui

    2016-03-01

    China, as a fast growing fossil-fuel-based economy, experiences increasing levels of air pollution. To tackle air pollution, China has taken the first steps by setting emission-reduction targets for nitrogen oxides (NO x ) and sulphur dioxide (SO2) in the 11th and 12th Five Year Plans. This paper uses two models-the Energy-Environment-Economy Model at the Global level (E3MG) and the global Chemistry Transport Model pTOMCAT-to test the effects of these policies. If the policy targets are met, then the maximum values of 32 % and 45 % reductions below 'business as usual' in the monthly mean NO x and SO2 concentrations, respectively, will be achieved in 2015. However, a decrease in NO x concentrations in some highly polluted areas of East, North-East and South-East China can lead to up to a 10% increase in the monthly mean concentrations in surface ozone in 2015. Our study demonstrates an urgent need for the more detailed analysis of the impacts and designs of air pollution reduction guidelines for China.

  19. Surface water characteristics and trace metals level of the Bonny/New Calabar River Estuary, Niger Delta, Nigeria

    Science.gov (United States)

    Onojake, M. C.; Sikoki, F. D.; Omokheyeke, O.; Akpiri, R. U.

    2017-05-01

    Surface water samples from three stations in the Bonny/New Calabar River Estuary were analyzed for the physicochemical characteristics and trace metal level in 2011 and 2012, respectively. Results show pH ranged from 7.56 to 7.88 mg/L; conductivity, 33,489.00 to 33,592.00 µScm-1; salinity, 15.33 to 15.50 ‰; turbidity, 4.35 to 6.65 NTU; total dissolved solids, 22111.00 to 23263.00 gm-3; dissolved oxygen, 4.53 to 6.65 mg/L; and biochemical oxygen demand, 1.72 mg/L. The level of some trace metals (Ca, Mg, K, Zn, Pb, Cd, Co, Cr, Cu, Fe, Ni, and Na) were also analyzed by Atomic absorption spectrometry with K, Zn, and Co being statistically significant ( P Concentrations of trace metals such as Pb, Cd, Zn, Ni, and Cr were higher than stipulated limits by WHO (2006). The result of the Metal Pollution Index suggests that the river was slightly affected and therefore continuous monitoring is necessary to avert possible public health implications of these metals on consumers of water and seafood from the study area.

  20. Surface water characteristics and trace metals level of the Bonny/New Calabar River Estuary, Niger Delta, Nigeria

    Science.gov (United States)

    Onojake, M. C.; Sikoki, F. D.; Omokheyeke, O.; Akpiri, R. U.

    2015-07-01

    Surface water samples from three stations in the Bonny/New Calabar River Estuary were analyzed for the physicochemical characteristics and trace metal level in 2011 and 2012, respectively. Results show pH ranged from 7.56 to 7.88 mg/L; conductivity, 33,489.00 to 33,592.00 µScm-1; salinity, 15.33 to 15.50 ‰; turbidity, 4.35 to 6.65 NTU; total dissolved solids, 22111.00 to 23263.00 gm-3; dissolved oxygen, 4.53 to 6.65 mg/L; and biochemical oxygen demand, 1.72 mg/L. The level of some trace metals (Ca, Mg, K, Zn, Pb, Cd, Co, Cr, Cu, Fe, Ni, and Na) were also analyzed by Atomic absorption spectrometry with K, Zn, and Co being statistically significant (P salinity during the dry season than wet season. Concentrations of trace metals such as Pb, Cd, Zn, Ni, and Cr were higher than stipulated limits by WHO (2006). The result of the Metal Pollution Index suggests that the river was slightly affected and therefore continuous monitoring is necessary to avert possible public health implications of these metals on consumers of water and seafood from the study area.

  1. Aliphatic and polycyclic aromatic hydrocarbons in surface sediments collected from mangroves with different levels of urbanization in southern Brazil.

    Science.gov (United States)

    Assunção, Maíra Algarve; Frena, Morgana; Santos, Ana Paula Stein; Dos Santos Madureira, Luiz Augusto

    2017-06-15

    Three mangroves located in southern Brazil, Carijós (CA), Rio Tavares (RT) and Itacorubi (ITA), with distinct anthropogenic influences, were assessed with regard to the presence of aliphatic and polycyclic aromatic hydrocarbons (PAH). In this study, the n-alkane concentrations ranged from 1.9μg g(-1) (CA) to 55.6μg g(-1) (ITA) (dry weight). The carbon preference index (CPI) ranged from 2.1 to 7.9 and values for the terrestrial/aquatic ratio (TAR) were >1. Thus, both indexes indicated the predominance of sediment of terrestrial origin, mainly comprised of higher plants. Concentrations of total PAH ranged from 6.8ng g(-1) (RT) to 437.3ng g(-1) (ITA). The PAH isomeric ratios indicated that these compounds originated mainly from pyrogenic sources. Nevertheless, levels of n-alkanes in the three mangroves were relatively low and they are considered typical of uncontaminated surface sediments, while the level of contamination with PAH was classified as low to moderate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Muscle-tendon units localization and activation level analysis based on high-density surface EMG array and NMF algorithm

    Science.gov (United States)

    Huang, Chengjun; Chen, Xiang; Cao, Shuai; Zhang, Xu

    2016-12-01

    Objective. Some skeletal muscles can be subdivided into smaller segments called muscle-tendon units (MTUs). The purpose of this paper is to propose a framework to locate the active region of the corresponding MTUs within a single skeletal muscle and to analyze the activation level varieties of different MTUs during a dynamic motion task. Approach. Biceps brachii and gastrocnemius were selected as targeted muscles and three dynamic motion tasks were designed and studied. Eight healthy male subjects participated in the data collection experiments, and 128-channel surface electromyographic (sEMG) signals were collected with a high-density sEMG electrode grid (a grid consists of 8 rows and 16 columns). Then the sEMG envelopes matrix was factorized into a matrix of weighting vectors and a matrix of time-varying coefficients by nonnegative matrix factorization algorithm. Main results. The experimental results demonstrated that the weightings vectors, which represent invariant pattern of muscle activity across all channels, could be used to estimate the location of MTUs and the time-varying coefficients could be used to depict the variation of MTUs activation level during dynamic motion task. Significance. The proposed method provides one way to analyze in-depth the functional state of MTUs during dynamic tasks and thus can be employed on multiple noteworthy sEMG-based applications such as muscle force estimation, muscle fatigue research and the control of myoelectric prostheses. This work was supported by the National Nature Science Foundation of China under Grant 61431017 and 61271138.

  3. Structure-based sampling and self-correcting machine learning for accurate calculations of potential energy surfaces and vibrational levels

    Science.gov (United States)

    Dral, Pavlo O.; Owens, Alec; Yurchenko, Sergei N.; Thiel, Walter

    2017-06-01

    We present an efficient approach for generating highly accurate molecular potential energy surfaces (PESs) using self-correcting, kernel ridge regression (KRR) based machine learning (ML). We introduce structure-based sampling to automatically assign nuclear configurations from a pre-defined grid to the training and prediction sets, respectively. Accurate high-level ab initio energies are required only for the points in the training set, while the energies for the remaining points are provided by the ML model with negligible computational cost. The proposed sampling procedure is shown to be superior to random sampling and also eliminates the need for training several ML models. Self-correcting machine learning has been implemented such that each additional layer corrects errors from the previous layer. The performance of our approach is demonstrated in a case study on a published high-level ab initio PES of methyl chloride with 44 819 points. The ML model is trained on sets of different sizes and then used to predict the energies for tens of thousands of nuclear configurations within seconds. The resulting datasets are utilized in variational calculations of the vibrational energy levels of CH3Cl. By using both structure-based sampling and self-correction, the size of the training set can be kept small (e.g., 10% of the points) without any significant loss of accuracy. In ab initio rovibrational spectroscopy, it is thus possible to reduce the number of computationally costly electronic structure calculations through structure-based sampling and self-correcting KRR-based machine learning by up to 90%.

  4. High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment.

    Science.gov (United States)

    Ozaktas, Tugba; Taskin, Bilgin; Gozen, Ayse G

    2012-12-01

    Freshwater fish, Alburnus alburnus (bleak), were captured from Lake Mogan, situated in Ankara, during spring. The surface mucus of the fish was collected and associated bacteria were cultured and isolated. By sequencing PCR-amplified 16S RNA encoding genes, the isolates were identified as members of 12 different genera: Acinetobacter, Aeromonas, Bacillus, Brevundimonas, Gordonia, Kocuria, Microbacterium, Mycobacterium, Pseudomonas, Rhodococcus, and Staphylococcus, in addition to one strain that was unidentified. The mucus-dwelling bacterial isolates were tested for resistance against ampicillin, kanamycin, streptomycin and chloramphenicol. About 95% of the isolates were found to be resistant to ampicillin, 93% to chloramphenicol, and 88% to kanamycin and streptomycin. A Microbacterium oxydans and the unidentified environmental isolate were resistant to all four antibiotics tested at very high levels (>1600 μg/ml ampicillin and streptomycin; >1120 μg/ml kanamycin; >960 μg/ml chloramphenicol). Only a Kocuria sp. was sensitive to all four antibiotics at the lowest concentrations tested (3.10 μg/ml ampicillin and streptomycin; 2.15 μg/ml kanamycin; 1.85 μg/ml chloramphenicol). The rest of the isolates showed different resistance levels. Plasmid isolations were carried out to determine if the multiple antibiotic resistance could be attributed to the presence of plasmids. However, no plasmid was detected in any of the isolates. The resistance appeared to be mediated by chromosome-associated functions. This study indicated that multiple antibiotic resistance at moderate to high levels is common among the current phenotypes of the fish mucus-dwelling bacterial populations in this temperate, shallow lake which has not been subjected to any aquaculturing so far but under anthropogenic effect being in a recreational area.

  5. Curve/surface representation and evolution using vector level sets with application to the shape-based segmentation problem.

    Science.gov (United States)

    Abd El Munim, Hossam E; Farag, Aly A

    2007-06-01

    In this paper, we revisit the implicit front representation and evolution using the vector level set function (VLSF) proposed in [1]. Unlike conventional scalar level sets, this function is designed to have a vector form. The distance from any point to the nearest point on the front has components (projections) in the coordinate directions included in the vector function. This kind of representation is used to evolve closed planar curves and 3D surfaces as well. Maintaining the VLSF property as the distance projections through evolution will be considered together with a detailed derivation of the vector partial differential equation (PDE) for such evolution. A shape-based segmentation framework will be demonstrated as an application of the given implicit representation. The proposed level set function system will be used to represent shapes to give a dissimilarity measure in a variational object registration process. This kind of formulation permits us to better control the process of shape registration, which is an important part in the shape-based segmentation framework. The method depends on a set of training shapes used to build a parametric shape model. The color is taken into consideration besides the shape prior information. The shape model is fitted to the image volume by registration through an energy minimization problem. The approach overcomes the conventional methods problems like point correspondences and weighing coefficients tuning of the evolution (PDEs). It is also suitable for multidimensional data and computationally efficient. Results in 2D and 3D of real and synthetic data will demonstrate the efficiency of the framework.

  6. Experimental Study of Reciprocating Friction between Rape Stalk and Bionic Nonsmooth Surface Units

    Directory of Open Access Journals (Sweden)

    Zheng Ma

    2015-01-01

    Full Text Available Background. China is the largest producer of rape oilseed in the world; however, the mechanization level of rape harvest is relatively low, because rape materials easily adhere to the cleaning screens of combine harvesters, resulting in significant cleaning losses. Previous studies have shown that bionic nonsmooth surface cleaning screens restrain the adhesion of rape materials, but the underlying mechanisms remain unclear. Objective. The reciprocating friction between rape stalk and bionic nonsmooth metal surface was examined. Methods. The short-time Fourier transform method was used to discriminate the stable phase of friction signals and the stick-lag distance was defined to analyze the stable reciprocating friction in a phase diagram. Results. The reciprocating friction between rape stalk and metal surface is a typical stick-slip friction, and the bionic nonsmooth metal surfaces with concave or convex units reduced friction force with increasing reciprocating frequency. The results also showed that the stick-lag distance of convex surface increased with reciprocating frequency, which indicated that convex surface reduces friction force more efficiently. Conclusions. We suggest that bionic nonsmooth surface cleaning screens, especially with convex units, restrain the adhesion of rape materials more efficiently compared to the smooth surface cleaning screens.

  7. Experimental Study of Reciprocating Friction between Rape Stalk and Bionic Nonsmooth Surface Units.

    Science.gov (United States)

    Ma, Zheng; Li, Yaoming; Xu, Lizhang

    2015-01-01

    Background. China is the largest producer of rape oilseed in the world; however, the mechanization level of rape harvest is relatively low, because rape materials easily adhere to the cleaning screens of combine harvesters, resulting in significant cleaning losses. Previous studies have shown that bionic nonsmooth surface cleaning screens restrain the adhesion of rape materials, but the underlying mechanisms remain unclear. Objective. The reciprocating friction between rape stalk and bionic nonsmooth metal surface was examined. Methods. The short-time Fourier transform method was used to discriminate the stable phase of friction signals and the stick-lag distance was defined to analyze the stable reciprocating friction in a phase diagram. Results. The reciprocating friction between rape stalk and metal surface is a typical stick-slip friction, and the bionic nonsmooth metal surfaces with concave or convex units reduced friction force with increasing reciprocating frequency. The results also showed that the stick-lag distance of convex surface increased with reciprocating frequency, which indicated that convex surface reduces friction force more efficiently. Conclusions. We suggest that bionic nonsmooth surface cleaning screens, especially with convex units, restrain the adhesion of rape materials more efficiently compared to the smooth surface cleaning screens.

  8. Level and ecological risk of four common metals in surface water along the Qinhuangdao coastal areas, China

    Science.gov (United States)

    Wang, Liping; Lei, Kun; Qiao, Yanzhen; Hao, Chenlin

    2017-01-01

    Heavy metals have been a widespread environmental contamination. Due to their associated ecological risk, the presence in water environment has attracted broad attention to public. Here 4 most common metals including copper (Cu), lead (Pb), cadmium (Cd) and zinc (Zn) were determined in surface water along the Qinhuangdao coastal areas, China. And their ecological risk was assessed using species sensitivity distribution (SSD) method. Total 12 stations were designed near the main estuary in the study area. The results showed that the concentrations of Cu, Pb, Cd and Zn of surface water were in the range of 847.81-1602.81µg/L, 0.42-1.59µg/L, 1.82-7.99µg/L and 26.9 -59.36µg/L, respectively. According to the National Seawater Quality Standard of China (GB3097-1997), Cu concentration in each station was much higher than the standard value of IV level (50µg/L), thus Cu could not even met the lowest level of water quality. In contrast, Pb met the I or II level of water quality, Cd and Zn met the II or III level. The HC5 (hazardous concentration for 5% of species) of each metal was obtained from their corresponding SSD curve. In case of Cu and Zn, the concentration at all sites exceeded their HC5 values, suggesting both of them had adverse effect on the aquatic organism, especially Cu. While Pb concentration at all sites was much lower than its HC5 value, thus Pb had no negative effect on aquatic life. In case of Cd, the concentration at 5 sites was higher than its HC5 value, and the other 7 sites was lower than its HC5 value, suggesting that adverse effect only occur at partial region in the study area. The RQ (risk quotient) value of Cu varied between 1355.41 and 2621.28, far larger than 1, indicating that 100% of sites had a much higher risk. The RQ of Zn varied between 6.06 and 13.88 (>1) indicating that Zn had a high risk in the study area. In case of Cd, the RQ ranged from 0.94 to 4.41 and about 92% of sites were larger than 1, suggesting that Cd had a high risk

  9. Insecticide-treated bed nets reduce plasma antibody levels and limit the repertoire of antibodies to Plasmodium falciparum variant surface antigens

    DEFF Research Database (Denmark)

    Askjaer, N; Maxwell, C; Chambo, W

    2001-01-01

    variant surface antigens (VSA) are important in the development of naturally acquired immunity to Plasmodium falciparum malaria and may thus be good indicators of immune status. We have compared the levels of VSA antibodies in plasma from children who have used ITN for 4 years to levels in plasma from...

  10. Concentration Levels and Ecological Risks of Persistent Organic Pollutants in the Surface Sediments of Tianjin Coastal Area, China

    Science.gov (United States)

    Lu, Xiaoxia; Chen, Chaoqi; Zhang, Shu; Hou, Zhen; Yang, Junjun

    2013-01-01

    Sediments were sampled from different surface water bodies in Tianjin coastal area, China, and persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were measured using GC/MS or GC/ECD. The purposes were to investigate the concentration levels of the POPs and to assess their ecological risks. The results showed that all the 16 priority PAHs were detected from the 10 sediments sampled with the total concentrations of the 16 PAHs ranging from 274.06 μg/kg to 2656.65 μg/kg, while the concentrations of the halogenated POPs were generally low except in the Dagu waste discharging river where the total concentrations of 24 OCPs, 35 PCBs, and 14 PBDEs were 3103.36 μg/kg, 87.31 μg/kg, and 13.88 μg/kg, respectively. In the studied sediments, PAHs exhibited risks to benthonic organisms; particularly the concentrations of naphthalene and/or acenaphthene exceeded their probable effect concentrations in several locations. In comparison, only in the Dagu waste discharging river, OCPs exhibited risks with the concentrations of heptachlor epoxide and lindane exceeding their probable effect concentrations. PCBs and PBDEs posed rare risks in the studied area. PMID:23401668

  11. Concentration Levels and Ecological Risks of Persistent Organic Pollutants in the Surface Sediments of Tianjin Coastal Area, China

    Directory of Open Access Journals (Sweden)

    Xiaoxia Lu

    2013-01-01

    Full Text Available Sediments were sampled from different surface water bodies in Tianjin coastal area, China, and persistent organic pollutants (POPs including polycyclic aromatic hydrocarbons (PAHs, organochlorine pesticides (OCPs, polychlorinated biphenyls (PCBs, and polybrominated diphenyl ethers (PBDEs were measured using GC/MS or GC/ECD. The purposes were to investigate the concentration levels of the POPs and to assess their ecological risks. The results showed that all the 16 priority PAHs were detected from the 10 sediments sampled with the total concentrations of the 16 PAHs ranging from 274.06 μg/kg to 2656.65 μg/kg, while the concentrations of the halogenated POPs were generally low except in the Dagu waste discharging river where the total concentrations of 24 OCPs, 35 PCBs, and 14 PBDEs were 3103.36 μg/kg, 87.31 μg/kg, and 13.88 μg/kg, respectively. In the studied sediments, PAHs exhibited risks to benthonic organisms; particularly the concentrations of naphthalene and/or acenaphthene exceeded their probable effect concentrations in several locations. In comparison, only in the Dagu waste discharging river, OCPs exhibited risks with the concentrations of heptachlor epoxide and lindane exceeding their probable effect concentrations. PCBs and PBDEs posed rare risks in the studied area.

  12. First evaluation of the serum level of anti-hepatitis B surface antigen after vaccination in Libya.

    Science.gov (United States)

    Madour, A; Alkout, A; Vanin, S

    2013-12-01

    The hepatitis B virus (HBV) vaccination schedule in Libya follows international recommendations (1st dose at birth, 2nd after 1 month and 3rd after 6 months). This research aimed to evaluate the long-term protection of the HBV immunization programme in Tripoli and to determine the best age to administer booster doses. Serum levels of hepatitis B surface antigen were determined in 277 randomly selected children aged 1-12 years. The response to HBV vaccine in 1-3-year-olds was 93.2%, but this declined with age and at 7-9 years after initial vaccination only 53.1% of children had protective titres (> or = 10 mIU/mL). No significant differences between males and females in antibody persistence or response to vaccine were observed. We recommend continuing the HBV vaccination programme and that a booster dose be given to 6-year-old children to ensure maximum protection during the period of school entry and beyond.

  13. Use of the discriminant Fourier-derived cepstrum with feature-level post-processing for surface electromyographic signal classification.

    Science.gov (United States)

    Chen, Xinpu; Zhu, Xiangyang; Zhang, Dingguo

    2009-12-01

    Myoelectrical pattern classification is a crucial part in multi-functional prosthesis control. This paper investigates a discriminant Fourier-derived cepstrum (DFC) and feature-level post-processing (FLPP) to discriminate hand and wrist motions using the surface electromyographic signal. The Fourier-derived cepstrum takes advantage of the Fourier magnitude or sub-band power energy of signals directly and provides flexible use of spectral information changing with different motions. Appropriate cepstral coefficients are selected by a proposed separability criterion to construct DFC features. For the post-processing, FLPP which combines features from several analysis windows is used to improve the feature performance further. In this work, two classifiers (a linear discriminant classifier and quadratic discriminant classifier) without hyper-parameter optimization are employed to simplify the training procedure and avoid the possible bias of feature evaluation. Experimental results of the 11-motion problem show that the proposed DFC feature outperforms traditional features such as time-domain statistics and autoregressive-derived cepstrum in terms of the classification accuracy, and it is a promising method for the multi-functionality and high-accuracy control of myoelectric prostheses.

  14. BAERLIN2014 - the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin

    Science.gov (United States)

    Bonn, Boris; von Schneidemesser, Erika; Andrich, Dorota; Quedenau, Jörn; Gerwig, Holger; Lüdecke, Anja; Kura, Jürgen; Pietsch, Axel; Ehlers, Christian; Klemp, Dieter; Kofahl, Claudia; Nothard, Rainer; Kerschbaumer, Andreas; Junkermann, Wolfgang; Grote, Rüdiger; Pohl, Tobias; Weber, Konradin; Lode, Birgit; Schönberger, Philipp; Churkina, Galina; Butler, Tim M.; Lawrence, Mark G.

    2016-06-01

    organic compounds (VOCs) at representative sites for traffic- and vegetation-affected sites. The quantification displayed notable horizontal heterogeneity of the short-lived gases and particle number concentrations. For example, baseline concentrations of the traffic-related chemical species CO and NO varied on average by up to ±22.2 and ±63.5 %, respectively, on the scale of 100 m around any measurement location. Airborne observations revealed the dominant source of elevated urban particulate number and mass concentrations being local, i.e., not being caused by long-range transport. Surface-based observations related these two parameters predominantly to traffic sources. Vegetated areas lowered the pollutant concentrations substantially with ozone being reduced most by coniferous forests, which is most likely caused by their reactive biogenic VOC emissions. With respect to the overall potential to reduce air pollutant levels, forests were found to result in the largest decrease, followed by parks and facilities for sports and leisure. Surface temperature was generally 0.6-2.1 °C lower in vegetated regions, which in turn will have an impact on tropospheric chemical processes. Based on our findings, effective future mitigation activities to provide a more sustainable and healthier urban environment should focus predominantly on reducing fossil-fuel emissions from traffic as well as on increasing vegetated areas.

  15. Self-consistent Green’s-function technique for bulk and surface impurity calculations: Surface core-level shifts by complete screening

    DEFF Research Database (Denmark)

    Aldén, M.; Abrikosov, I. A.; Johansson, B.

    1994-01-01

    We have implemented an efficient self-consistent Green's-function technique, based on the tight-binding linear-muffin-tin-orbitals method, for calculating the electronic structure and total energy of a substitutional impurity located either in the bulk or at the surface. The technique makes use...

  16. Ground-water-level monitoring, basin boundaries, and potentiometric surfaces of the aquifer system at Edwards Air Force Base, California, 1992

    Science.gov (United States)

    Rewis, D.L.

    1995-01-01

    A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.

  17. Potentiometric surface, 2012, and water-level differences, 2005-12, of the Sparta Aquifer in north-central Louisiana

    Science.gov (United States)

    McGee, Benton D.; Brantly, Jeffrey A.

    2015-01-01

    The Sparta aquifer is used in 15 parishes in north-central Louisiana, primarily for public supply and industrial purposes. Of those parishes, eight (Bienville, Claiborne, Jackson, Lincoln, Ouachita, Union, Webster, and Winn) rely on the Sparta aquifer as their principal source of groundwater. In 2010, withdrawals from the Sparta aquifer in Louisiana totaled 63.11 million gallons per day (Mgal/d), a reduction of more than 11 percent from 1995, when the highest rate of withdrawals (71.32 Mgal/d) from the Sparta aquifer were documented. The Sparta aquifer provides water for a variety of purposes which include public supply (34.61 Mgal/d), industrial (25.60 Mgal/d), rural domestic (1.50 Mgal/d), and various agricultural (1.40 Mgal/d). Of the 13 major aquifers or aquifer systems in Louisiana, the Sparta aquifer is currently (2012) the sixth most heavily pumped. The Sparta aquifer is the second most heavily pumped aquifer in Arkansas, which borders Louisiana to the north. In 2005, 170 Mgal/d were withdrawn from the Sparta aquifer in eastern and southern Arkansas; of that total, about 15.55 Mgal/d were withdrawn from the aquifer in Union County, which borders Claiborne and Union Parishes to the north. By 1997, a large cone of depression (a cone-shaped depression in the potentiometric surface caused by and centered on a pumping well or wells) in the Sparta aquifer centered over Union County had merged with the cone of depression at West Monroe. In 2004, the rate of withdrawal from the Sparta aquifer in Union County began to decline and water levels in the aquifer began to rise in nearby areas of Arkansas and Louisiana.

  18. Reduction of Fermi level pinning at Au-MoS2 interfaces by atomic passivation on Au surface

    Science.gov (United States)

    Min, Kyung-Ah; Park, Jinwoo; Wallace, Robert M.; Cho, Kyeongjae; Hong, Suklyun

    2017-03-01

    Monolayer molybdenum disulfide (MoS2), which is a semiconducting material with direct band gap of ˜1.8 eV, has drawn much attention for application in field effect transistors (FETs). In this connection, it is very important to understand the Fermi level pinning (FLP) which occurs at metal-semiconductor interfaces. It is known that MoS2 has an n-type contact with Au, which is a high work function metal, representing the strong FLP at Au-MoS2 interfaces. However, such FLP can obstruct the attainment of high performance of field effect devices. In this study, we investigate the reduction of FLP at Au-MoS2 interfaces by atomic passivation on Au(111) using first-principles calculations. To reduce the FLP at Au-MoS2 interfaces, we consider sulfur, oxygen, nitrogen, fluorine, and hydrogen atoms that can passivate the surface of Au(111). Calculations show that passivating atoms prevent the direct contact between Au(111) and MoS2, and thus FLP at Au-MoS2 interfaces is reduced by weak interaction between atom-passivated Au(111) and MoS2. Especially, FLP is greatly reduced at sulfur-passivated Au-MoS2 interfaces with the smallest binding energy. Furthermore, fluorine-passivated Au(111) can form ohmic contact with MoS2, representing almost zero Schottky barrier height (SBH). We suggest that SBH can be controlled depending on the passivating atoms on Au(111).

  19. A novel model to assess the efficacy of steam surface pasteurization of cooked surimi gels inoculated with realistic levels of Listeria innocua.

    Science.gov (United States)

    Skåra, Torstein; Valdramidis, Vasilis P; Rosnes, Jan Thomas; Noriega, Estefanía; Van Impe, Jan F M

    2014-12-01

    Steam surface pasteurization is a promising decontamination technology for reducing pathogenic bacteria in different stages of food production. The effect of the artificial inoculation type and initial microbial load, however, has not been thoroughly assessed in the context of inactivation studies. In order to optimize the efficacy of the technology, the aim of this study was to design and validate a model system for steam surface pasteurization, assessing different inoculation methods and realistic microbial levels. More specifically, the response of Listeria innocua, a surrogate organism of Listeria monocytogenes, on a model fish product, and the effect of different inoculation levels following treatments with a steam surface pasteurization system was investigated. The variation in the resulting inoculation level on the samples was too large (77%) for the contact inoculation procedure to be further considered. In contrast, the variation of a drop inoculation procedure was 17%. Inoculation with high levels showed a rapid 1-2 log decrease after 3-5 s, and then no further inactivation beyond 20 s. A low level inoculation study was performed by analysing the treated samples using a novel contact plating approach, which can be performed without sample homogenization and dilution. Using logistic regression, results from this method were used to model the binary responses of Listeria on surfaces with realistic inoculation levels. According to this model, a treatment time of 23 s will result in a 1 log reduction (for P = 0.1).

  20. History of surface displacements at the Yellowstone Caldera, Wyoming, from leveling surveys and InSAR observations, 1923-2008

    Science.gov (United States)

    Dzurisin, Daniel; Wicks, Charles W.; Poland, Michael P.

    2012-01-01

    during June-July 1995 - the strongest swarm since 1985. Rather than a single deformation source as inferred from leveling surveys, the InSAR images revealed two distinct sources - one beneath each resurgent dome on the caldera floor. Subsequently, repeated GPS surveys (sometimes referred to as "campaign" surveys to distinguish them from continuous GPS observations) and InSAR images revealed a third deformation source beneath the north caldera rim. The north-rim source started to inflate in or about 1995, resulting in as much as 80 mm of surface uplift by 2000. Meanwhile, motion of the caldera floor changed from uplift to subsidence during 1997-8. The north rim area rose, while the entire caldera floor (including both domes) subsided until 2002, when both motions paused. Uplift in the northeast part of the caldera resumed in mid-2004 at a historically unprecedented rate of as much as 70 mm/yr, while the north rim area subsided at a lesser rate. Resurveys of the level line across the northeast part of the caldera in 2005 and 2007 indicated the greatest average uplift rate since the initial survey in 1923-53±3 mm/yr. Data from a nearby continuous GPS (CGPS) station showed that the uplift rate slowed to 40-50 mm/yr during 2007-8 and to near zero by September 2009. Following an intense earthquake swarm during January-February 2010, this one near the northwest caldera rim and the strongest since the 1985 swarm in the same general area, CGPS stations recorded the onset of subsidence throughout the entire caldera. Any viable model for the cause(s) of ground deformation at Yellowstone should account for (1) three distinct deformation sources and their association with both resurgent domes and the north caldera rim; (2) interplay among these sources, as suggested by the timing of major changes in deformation mode; (3) migration of the area of greatest subsidence or uplift from the northeast part of the caldera to the southwest part during 1992-95 and 1995-97, respectively; (4

  1. AVHRR Pathfinder version 5.3 level 3 collated (L3C) global 4km sea surface temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AVHRR Pathfinder Version 5.3 (PFV53) L3C Sea Surface Temperature data set is a collection of global, twice-daily (Day and Night) 4km sea surface temperature...

  2. Use of Surface-Enhanced Raman Spectroscopy in Inorganic Syntheses for an Upper-Level Exploratory Lab

    Science.gov (United States)

    Seney, Caryn S.; Yelverton, Joshua C.; Eanes, Sharon; Patel, Vikas; Riggs, Julia; Wright, Sarah; Bright, Robin M.

    2007-01-01

    An experiment is designed where students will be using both gold and silver nanoparticles to study the enhancement factors of organic molecules adsorbed to the surface of the nanoparticles during or after synthesis by using surface-enhanced Raman spectroscopy (SERS). The experiment has helped students learn about the theory and experimental…

  3. ENSO Forced Variations of the Sea Surface Temperature and Adjusted Sea Level Along the West Coast of the United States

    Science.gov (United States)

    1993-12-01

    Schwing, Co-Advisor Curtis A. Collins, Co-Advisor and Chairman Department of Oceanography ii ABSTRACT Daily coastal surface temperature and adjusted...5 II . ANALYSIS METHODS .................................................................................. 6 A. SURFACE TEMPERATURE...73 V. CONCLUSIONS AND RECOMMENDATIONS ............................................. 78 APPENDIX A - FARALLON ISLANDS TEMPERATURES FILLED BY BODEGA

  4. High-performance chromatofocusing using linear and concave pH gradients formed with simple buffer mixtures. II. Separation of proteins.

    Science.gov (United States)

    Kang, X; Bates, R C; Frey, D D

    2000-08-18

    The separation of proteins using high-performance chromatofocusing with linear or concave pH gradients formed using simple mixtures of buffering species in the elution buffer is investigated experimentally. The separation achieved is comparable to that using polyampholyte elution buffers with these types of systems. More specifically, protein band widths at one half of the band height in the range between 0.1 and 0.025 pH units were observed, and good resolution was achieved of protein variants differing by a single amino acid residue in separation times of 30 min or less. An especially useful elution buffer is investigated that contains only four buffering species and that produces a linear pH gradient in the range between pH 9.5 and 6.0 when used together with a particular high-performance column packing made specifically for chromatofocusing. This elution buffer and column packing combination is evaluated by using it for the chromatofocusing of equine myoglobin and human hemoglobin variants. Additional applications are described in which a polyethyleneimine derivatized silica column packing and a pH gradient that is concave in shape are used for the separation of proteins in an E. coli cell lysate.

  5. Electrically templated dewetting of a UV-curable prepolymer film for the fabrication of a concave microlens array with well-defined curvature.

    Science.gov (United States)

    Li, Xiangming; Tian, Hongmiao; Ding, Yucheng; Shao, Jinyou; Wei, Yuping

    2013-10-23

    This paper presents an economic method, based on electrically templated dewetting of a UV-curable prepolymer, for fabricating a concave microlens array (MLA) of high quality and high density. In our strategy, a voltage is applied to an electrode pair consisting of a conductive substrate coated with a UV-curable prepolymer film and a microhole-arrayed silicon template, sandwiching an air gap, to dewet the prepolymer film into a curved air-liquid interface. At or beyond a critical voltage, the curved prepolymer can be pulled quickly into contact with the protrusive underside of the silicon template. Contact of the prepolymer with the template can be detected by monitoring the leaky current in the polymer, followed by a UV curing of the prepolymer. Finally, by separating the mold from the solidified polymer, a concave MLA is obtained. The curvature of the MLA can be well-defined simply by changing the air gap between the mold and prepolymer film. Besides, the dewetting strategy results in a much smaller adhesion area between the mold and solidified polymer structures, which allows for easy separation of the mold from the MLA in a large-area operation.

  6. Effect of Welding Speeds on Mechanical Properties of Level Compensation Friction Stir Welded 6061-T6 Aluminum Alloy

    Science.gov (United States)

    Wen, Quan; Yue, Yumei; Ji, Shude; Li, Zhengwei; Gao, Shuangsheng

    2016-04-01

    In order to eliminate the flash, arc corrugation and concave in weld zone, level compensation friction stir welding (LCFSW) was put forward and successfully applied to weld 6061-T6 aluminum alloy with varied welding speed at a constant tool rotational speed of 1,800 rpm in the present study. The glossy joint with equal thickness of base material can be attained, and the shoulder affected zone (SAZ) was obviously reduced. The results of transverse tensile test indicate that the tensile strength and elongation reach the maximum values of 248 MPa and 7.1% when the welding speed is 600 mm/min. The microhardness of weld nugget (WN) is lower than that of base material. The tensile fracture position locates at the heat affected zone (HAZ) of the advancing side (AS), where the microhardness is the minimum. The fracture surface morphology represents the typical ductile fracture.

  7. Quantum surface of section method demonstration of semiclassical Berry-Robnik energy level spacing distribution in a generic 2-dim hamiltonian system

    CERN Document Server

    Prosen, T

    1995-01-01

    The recently developed quantum surface of section method is applied to a search for extremely high-lying energy levels in a simple but generic Hamiltonian system between integrability and chaos, namely the semiseparable 2-dim oscillator. Using the stretch of 13,445 consecutive levels with the sequential number around 1.8\\cdot 10^7 (eighteen million) we have clearly demonstrated the validity of the semiclassical Berry-Robnik level spacing distribution while at 1000 times smaller sequential quantum numbers we find the very persistent quasi universal phenomenon of power-law level repulsion which is globally very well described by the Brody distribution.

  8. Towards an atomic level understanding of niobia based catalysts and catalysis by combining the science of catalysis with surface science

    Directory of Open Access Journals (Sweden)

    Martin Schmal

    2009-06-01

    Full Text Available The science of catalysis and surface science have developed, independently, key information for understanding catalytic processes. One might argue: is there anything fundamental to be discovered through the interplay between catalysis and surface science? Real catalysts of monometallic and bimetallic Co/Nb2O5 and Pd-Co/Nb2O5 catalysts showed interesting selectivity results on the Fischer-Tropsch synthesis (Noronha et al. 1996, Rosenir et al. 1993. The presence of a noble metal increased the C+5 selectivity and decreased the methane formation depending of the reduction temperature. Model catalyst of Co-Pd supported on niobia and alumina were prepared and characterized at the atomic level, thus forming the basis for a comparison with "real" support materials. Growth, morphology and structure of both pure metal and alloy particles were studied. It is possible to support the strong metal support interaction suggested by studies on real catalysts via the investigation of model systems for niobia in comparison to alumina support in which this effect does not occur. Formation of Co2+ penetration into the niobia lattice was suggested on the basis of powder studies and can be fully supported on the basis of model studies. It is shown for both real catalysts and model systems that oxidation state of Co plays a key role in controlling the reactivity in Fischer-Tropsch reactions systems and that the addition of Pd is a determining factor for the stability of the catalyst. It is demonstrated that the interaction with unsaturated hydrocarbons depends strongly on the state of oxidation.As ciências da catálise e da superfície têm desenvolvido independentemente temas básicos para o entendimento de processos catalíticos. Pode-se até questionar se há ainda algo fundamental para ser descoberto através da interface entre catálise eciência da superfície? Catalisadores mono e bimetálicos de Co/Nb2O5 e Pd-Co/ Nb2O5 apresentaram resultados interessantes de

  9. Rendering of surface-geometries at job-generation level for camouflaging the layered nature of Additively Manufactured parts

    DEFF Research Database (Denmark)

    Pedersen, D. B.; Hansen, H. N.; Nielsen, J. S.

    2014-01-01

    . An often used method for visualization of complex geometries within CGI is by producing a geometrical primitive after which the primitive is passed through a renderer.[2] Examples can be geometries with hair, leather structure and their like. Should the entire geometry including surface definition sought......] It is proposed to camouflage these layers in order to produce parts with a better visual appeal, and to add functional surface structures. In order to generate such surface structures without adding a challenging computational overhead at job-generation, inspiration from Computer Generated Imaging (CGI) is found...

  10. Residue determination and levels of glyphosate in surface waters, sediments and soils associated with oil palm plantation in Tasik Chini, Pahang, Malaysia

    Science.gov (United States)

    Mardiana-Jansar, K.; Ismail, B. S.

    2014-09-01

    Levels of glyphosate and its main metabolite were determined in surface water, soil and sediment samples from an oil palm plantation area located at Tasik Chini, Pahang, Malaysia. The optimization analytical method has been developed for the determination of glyphosate herbicide and its metabolite amino-methyl-phosphonic acid (AMPA) in surface waters to a level of 0.1μg/L, while in sediments and soils to a level of 0.5μg/g with a good linearity in the calibration range of 1-100μg/L. The procedure involves a pre-columnderivatization step with 9-fluorenyl-methyl-chloroformate (FMOC-Cl) yielding highly fluorescent derivatives of the analytes which can be determined by HPLC with fluorescence detection. In the field, levels of glyphosate in surface waters ranges from not detected to 1.0mg/L, while in soils and sediments were from not detected to 6.0mg/kg. For AMPA, the residues in surface waters were between not detected to 2.0mg/L, while in soil and sediment samples were from not detected to 5mg/kg. This variation of glyphosate and AMPA levels depended directly on time of pesticide application and the season.

  11. Sensitivity of the Mediterranean sea level to atmospheric pressure and free surface elevation numerical formulation in NEMO

    Directory of Open Access Journals (Sweden)

    P. Oddo

    2014-06-01

    Full Text Available The sensitivity of the dynamics of the Mediterranean Sea to atmospheric pressure and free surface elevation formulation using NEMO (Nucleus for European Modelling of the Ocean was evaluated. Four different experiments were carried out in the Mediterranean Sea using filtered or explicit free surface numerical schemes and accounting for the effect of atmospheric pressure in addition to wind and buoyancy fluxes. Model results were evaluated by coherency and power spectrum analysis with tide gauge data. We found that atmospheric pressure plays an important role for periods shorter than 100 days. The free surface formulation is important to obtain the correct ocean response for periods shorter than 30 days. At frequencies higher than 15 days−1 the Mediterranean basin's response to atmospheric pressure was not coherent and the performance of the model strongly depended on the specific area considered. A large amplitude seasonal oscillation observed in the experiments using a filtered free surface was not evident in the corresponding explicit free surface formulation case which was due to a phase shift between mass fluxes in the Gibraltar Strait and at the surface. The configuration with time splitting and atmospheric pressure always performed best; the differences were enhanced at very high frequencies.

  12. Kinetics of Hepatitis B Surface Antigen Level in Chronic Hepatitis B Patients who Achieved Hepatitis B Surface Antigen Loss during Pegylated Interferon Alpha-2a Treatment

    Directory of Open Access Journals (Sweden)

    Ming-Hui Li

    2017-01-01

    Conclusions: Patients with lower baseline HBsAg levels and more rapid decline during early treatment with PEG-IFN are more likely to achieve HBsAg loss during 96 weeks of treatment, and extended therapy longer than 48 weeks may be required to achieve HBsAg loss.

  13. Structural origin of Si-2p core-level shifts from Si(100)-c[4x2] surface: A spectral x-ray photoelectron diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Tonner, B.P. [Univ. of Wisconsin, Milwaukee, WI (United States); Denlinger, J. [Univ. of Wisconsin, Milwaukee, WI (United States)][Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The authors have performed angle-resolved x-ray photoelectron diffraction (XPD) from a Si(100)-c(4x2) surface to study the structural origin of Si-2p core-level shifts. In the experiment, the highly resolved surface Si-2p core-level spectra were measured as a fine grid of hemisphere and photon energies, using the SpectroMicroscopy Facility {open_quotes}ultraESCA{close_quotes} instrument. By carefully decomposing the spectra into several surface peaks, the authors are able to obtain surface-atom resolved XPD patterns. Using a multiple scattering analysis, they derived a detailed atomic model for the Si(100)-c(4x2) surface. In this model, the asymmetric dimers were found tilted by 11.5 plus/minus 2.0 degrees with bond length of 2.32 plus/minus 0.05{angstrom}. By matching model XPD patterns to experiment, the authors can identify which atoms in the reconstructed surface are responsible for specific photoemission lines in the 2p spectrum.

  14. Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

    2016-10-19

    OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

  15. Raising surface water levels in peat areas with dairy farming upscaling hydrological, agronomical and economic effects from farm-scale to local scale.

    NARCIS (Netherlands)

    Vos, de J.A.; Bakel, van P.J.T.; Hoving, I.E.; Smidt, R.A.

    2010-01-01

    Raising surface water levels in peat areas is a measure to reduce soil subsidence, to prevent decay of wooden foundations and to stimulate wet nature restoration and reduce greenhouse gas emissions. However, in these areas dairy farms are present and farming at wetter soils is difficult due to lower

  16. Estimating the Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR

    NARCIS (Netherlands)

    Fettweis, X.; Franco, B.; Tedesco, M.; van Angelen, J.H.; Lenaerts, J.T.M.; van den Broeke, M.R.; Gallée, H.

    2013-01-01

    To estimate the sea level rise (SLR) originating from changes in surface mass balance (SMB) of the Greenland ice sheet (GrIS), we present 21st century climate projections obtained with the regional climate model MAR (Mod`ele Atmosph´erique R´egional), forced by output of three CMIP5 (Coupled Model I

  17. Comparative assessment of the recognition of domain-specific CD163 monoclonal antibodies in human monocytes explains wide discrepancy in reported levels of cellular surface CD163 expression

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Etzerodt, Anders; Moestrup, Søren Kragh;

    2011-01-01

    continue to exhibit great discrepancy in the measured percentage of CD163-expressing blood monocytes in healthy individuals. In this study we sought to clarify this inconsistency in reported levels of CD163 surface expression by a detailed analysis of a panel of CD163 antibodies used in previous studies...... 1 (MAC2-158), domain 4 (R-20), domain 7 (GHI/61), and domain 9 (RM3/1). The CD163 monoclonal antibodies were characterized in binding and endocytosis experiments in human macrophages and CD163-transfected Flp-In CHO cells. Calcium-dependent ligand binding was assessed using surface plasmon resonance......-terminal part of CD163, remote from the membrane surface. Moreover, the proportion of CD163 positive monocytes observed was highly dependent on free calcium. GHI/61 did not exhibit CD163 binding in the presence of calcium as measured by surface plasmon resonance, which was in agreement with the concordant loss...

  18. Effect of uncertainty in surface mass balance elevation feedback on projections of the future sea level contribution of the Greenland ice sheet – Part 2: Projections

    Directory of Open Access Journals (Sweden)

    A. Quiquet

    2013-02-01

    Full Text Available We apply a new parameterisation of the Greenland ice sheet (GrIS feedback between surface mass balance (SMB: the sum of surface accumulation and surface ablation and surface elevation in the MAR regional climate model (Edwards et al., 2013 to projections of future climate change using five ice sheet models (ISMs. The MAR climate projections are for 2000–2199, forced by the ECHAM5 and HadCM3 global climate models (GCMs under the SRES A1B emissions scenario. The additional sea level contribution due to the SMB-elevation feedback averaged over five ISM projections for ECHAM5 and three for HadCM3 is 4.3% (best estimate; 95% credibility interval 1.8–6.9% at 2100, and 9.6% (best estimate; 95% credibility interval 3.6–16.0% at 2200. In all results the elevation feedback is significantly positive, amplifying the GrIS sea level contribution relative to the MAR projections in which the ice sheet topography is fixed: the lower bounds of our 95% credibility intervals (CIs for sea level contributions are larger than the "no feedback" case for all ISMs and GCMs. Our method is novel in sea level projections because we propagate three types of modelling uncertainty – GCM and ISM structural uncertainties, and elevation feedback parameterisation uncertainty – along the causal chain, from SRES scenario to sea level, within a coherent experimental design and statistical framework. The relative contributions to uncertainty depend on the timescale of interest. At 2100, the GCM uncertainty is largest, but by 2200 both the ISM and parameterisation uncertainties are larger. We also perform a~perturbed parameter ensemble with one ISM to estimate the shape of the projected sea level probability distribution; our results indicates that the probability density is slightly skewed towards higher sea level contributions.

  19. Molecular-Level Insight of the Effect of Hofmeister Anions on the Interfacial Surface Tension of a Model Protein

    Energy Technology Data Exchange (ETDEWEB)

    Willow, Soohaeng Yoo; Xantheas, Sotiris S.

    2017-03-21

    The effect of the Hofmeister anion series on the structure and stability of proteins is often discussed using simple systems such as a water-vapor interface with the assumption that the vapor region mimics the hydrophobic surface. Microscopic theories suggest that the Hofmeister anion series is highly correlated with the different contributions of the various ions to the surface tension of such a water-vapor interface. Proteins, however, have both hydrophobic and hydrophilic regions rather than just a pure hydrophobic one. Using a solvated parallel β -sheet layer consisting of both hydrophobic and positively charged hydrophilic surfaces as a more realistic model to represent a protein surface, we investigated the interaction of such a system with hydrophilic-like (SO42-) and hydrophobic-like (ClO4-) anions via Born-Oppenheimer Molecular Dynamics (BOMD) simulations. We found that both the SO42- and ClO4- anions prefer to reside on the hydrophilic rather than on the hydrophobic surface of the parallel β -sheet layer. In addition, our simulations suggest that the ClO4- ions not only penetrate towards the peptide groups through the hydrophilic residues, but also allow water molecules to penetrate as well to form water-peptide hydrogen bonds, while the SO42- ions stabilize the interface of the water-hydrophilic surface. Our results render a plausible explanation of why hydrophobic-like Hofmeister anions act as protein denaturants. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle.

  20. Fabrication and qualification of roughness reference samples for industrial testing of surface roughness levels below 0.5 nm Sq

    Science.gov (United States)

    Faehnle, O.; Langenbach, E.; Zygalsky, F.; Frost, F.; Fechner, R.; Schindler, A.; Cumme, M.; Biskup, H.; Wünsche, C.; Rascher, R.

    2015-08-01

    Applying reactive ion beam etching (RIBE) processes at the Leibniz Institute of Surface Modification (IOM), several reference samples to be used in industry for calibrating of roughness testing equipment have been generated with the smoothest sample featuring 0.1 nm rms Sq. Subsequently these reference samples have been measured cross-site applying atomic force microscopy (AFM), white light interferometry (WLI), Nomarski1 microscopy (NM) and scatterometry (iTIRM2) determining the appropriate range of measurable rms surface roughness for each industrial measuring device.