WorldWideScience

Sample records for surfaces remained smooth

  1. Thermal smoothing of rough surfaces in vacuo

    Science.gov (United States)

    Wahl, G.

    1986-01-01

    The derivation of equations governing the smoothing of rough surfaces, based on Mullins' (1957, 1960, and 1963) theories of thermal grooving and of capillarity-governed solid surface morphology is presented. As an example, the smoothing of a one-dimensional sine-shaped surface is discussed.

  2. Rubber friction on (apparently) smooth lubricated surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mofidi, M; Prakash, B [Division of Machine Elements, Luleaa University of Technology, Luleaa SE-97187 (Sweden); Persson, B N J [IFF, FZ-Juelich, 52425 Juelich (Germany); Albohr, O [Pirelli Deutschland AG, 64733 Hoechst/Odenwald, Postfach 1120 (Germany)

    2008-02-27

    We study rubber sliding friction on hard lubricated surfaces. We show that even if the hard surface appears smooth to the naked eye, it may exhibit short-wavelength roughness, which may make the dominant contribution to rubber friction. That is, the observed sliding friction is mainly due to the viscoelastic deformations of the rubber by the counterface surface asperities. The results presented are of great importance for rubber sealing and other rubber applications involving (apparently) smooth surfaces.

  3. Rubber friction on (apparently) smooth lubricated surfaces

    Science.gov (United States)

    Mofidi, M.; Prakash, B.; Persson, B. N. J.; Albohr, O.

    2008-02-01

    We study rubber sliding friction on hard lubricated surfaces. We show that even if the hard surface appears smooth to the naked eye, it may exhibit short-wavelength roughness, which may make the dominant contribution to rubber friction. That is, the observed sliding friction is mainly due to the viscoelastic deformations of the rubber by the counterface surface asperities. The results presented are of great importance for rubber sealing and other rubber applications involving (apparently) smooth surfaces.

  4. Smooth surfaces from rational bilinear patches

    KAUST Repository

    Shi, Ling

    2014-01-01

    Smooth freeform skins from simple panels constitute a challenging topic arising in contemporary architecture. We contribute to this problem area by showing how to approximate a negatively curved surface by smoothly joined rational bilinear patches. The approximation problem is solved with help of a new computational approach to the hyperbolic nets of Huhnen-Venedey and Rörig and optimization algorithms based on it. We also discuss its limits which lie in the topology of the input surface. Finally, freeform deformations based on Darboux transformations are used to generate smooth surfaces from smoothly joined Darboux cyclide patches; in this way we eliminate the restriction to surfaces with negative Gaussian curvature. © 2013 Elsevier B.V.

  5. Smooth surfaces from bilinear patches: Discrete affine minimal surfaces

    KAUST Repository

    Käferböck, Florian

    2013-06-01

    Motivated by applications in freeform architecture, we study surfaces which are composed of smoothly joined bilinear patches. These surfaces turn out to be discrete versions of negatively curved affine minimal surfaces and share many properties with their classical smooth counterparts. We present computational design approaches and study special cases which should be interesting for the architectural application. 2013 Elsevier B.V.

  6. Smooth embeddings with Stein surface images

    CERN Document Server

    Gompf, Robert E

    2011-01-01

    A simple characterization is given of open subsets of a complex surface that smoothly perturb to Stein open subsets. As applications, complex 2-space C^2 contains domains of holomorphy (Stein open subsets) that are exotic R^4's, and others homotopy equivalent to the 2-sphere but cut out by smooth, compact 3-manifolds. Pseudoconvex embeddings of Brieskorn spheres and other 3-manifolds into complex surfaces are constructed, as are pseudoconcave holomorphic fillings (with disagreeing contact and boundary orientations). Pseudoconcave complex structures on Milnor fibers are found. A byproduct of this construction is a simple polynomial expression for the signature of the (p,q,npq-1) Milnor fiber. Akbulut corks in complex surfaces can always be chosen to be pseudoconvex or pseudoconcave submanifods. The main theorem is expressed via Stein handlebodies (possibly infinite), which are defined holomorphically in all dimensions by extending Stein theory to manifolds with noncompact boundary.

  7. How a Nanodroplet Diffuses on Smooth Surfaces

    Science.gov (United States)

    Li, Chu; Huang, Jizu; Li, Zhigang

    2016-11-01

    In this study, we investigate how nanodroplets diffuse on smooth surfaces through molecular dynamics (MD) simulations and theoretical analyses. The simulations results show that the surface diffusion of nanodroplet is different from that of single molecules and solid nanoparticles. The dependence of nanodroplet diffusion coefficient on temperature is surface wettability dependent, which undergoes a transition from linear to nonlinear as the surface wettability is weakened due to the coupling of temperature and surface energy. We also develop a simple relation for the diffusion coefficient by using the contact angle and contact radius of the droplet. It works well for different surface wettabilities and sized nanodroplets, as confirmed by MD simulations. This work was supported by the Research Grants Council of the Hong Kong Special Administrative Region under Grant No. 615312.

  8. Method for producing smooth inner surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Charles A.

    2016-05-17

    The invention provides a method for preparing superconducting cavities, the method comprising causing polishing media to tumble by centrifugal barrel polishing within the cavities for a time sufficient to attain a surface smoothness of less than 15 nm root mean square roughness over approximately a 1 mm.sup.2 scan area. The method also provides for a method for preparing superconducting cavities, the method comprising causing polishing media bound to a carrier to tumble within the cavities. The method also provides for a method for preparing superconducting cavities, the method comprising causing polishing media in a slurry to tumble within the cavities.

  9. Drop splash on a smooth, dry surface

    Science.gov (United States)

    Riboux, Guillaume; Gordillo, Jose Manuel; Korobkin, Alexander

    2013-11-01

    It is our purpose here to determine the conditions under which a drop of a given liquid with a known radius R impacting against a smooth impermeable surface at a velocity V, will either spread axisymmetrically onto the substrate or will create a splash, giving rise to usually undesired star-shaped patterns. In our experimental setup, drops are generated injecting low viscosity liquids falling under the action of gravity from a stainless steel hypodermic needle. The experimental observations using two high speed cameras operating simultaneously and placed perpendicularly to each other reveal that, initially, the drop deforms axisymmetrically, with A (T) the radius of the wetted area. For high enough values of the drop impact velocity, a thin sheet of liquid starts to be ejected from A (T) at a velocity Vjet > V for instants of time such that T >=Tc . If Vjet is above a certain threshold, which depends on the solid wetting properties as well as on the material properties of both the liquid and the atmospheric gas, the rim of the lamella dewets the solid to finally break into drops. Using Wagner's theory we demonstrate that A (T) =√{ 3 RVT } and our results also reveal that Tc We - 1 / 2 =(ρV2 R / σ) - 1 / 2 and Vjet We 1 / 4 .

  10. Studies on argon collisions with smooth and rough tungsten surfaces.

    Science.gov (United States)

    Ozhgibesov, M S; Leu, T S; Cheng, C H; Utkin, A V

    2013-09-01

    The aim of this work is to investigate argon scattering behaviors on the smooth and rough tungsten surfaces. Current work deals with numerical simulation of nanoscale heat transfer process accompanying with rarefied gas-solid substrate interactions using molecular dynamics (MD) method. Taking into account that this method is very time consuming, MD simulation using CUDA capable Graphic Cards is implemented. The results found that imperfection of the surface significantly influences on gas atom's momentum change upon collision. However, the energy exchange rate remains unchanged regardless to the surface roughness. This finding is in contrast with the results in extant literatures. We believed the results found in this paper are important for both numerical and theoretical analyses of rarefied gas flow in micro- and nano-systems where the choice of boundary conditions significantly influences flow.

  11. Smooth coronal surface, resin restoration and microleakage.

    Science.gov (United States)

    Yanikoğlu, F; Türkmen, C; Kartal, N; Başaran, B

    1997-09-01

    The space between the resin and the cavity walls has always become interesting to search. The aim of this study was to evaluate any differences on leakage values of Class 5 type resin restorations prepared on surrounding surfaces of the tooth crown. Ninety human teeth were prepared as Class 5 cavities on buccal, lingual, mesial and distal surfaces and were randomly divided into groups for bevelling, groove preparation and as control. The subgroups were arranged as fluoride gel and/or sealant applications. Fluoride gel was applied following the cavity preparations. Sealant was applied over composite resin restorations. Treated teeth were thermocycled and immersed into dye solution for 96 hours. The restorations were evaluated in a stereo-microscope following the sectioning. Bevelling of the cavosurfaces and/or preparation of a groove addition to cavity procedures did not make any difference on the microleakage scores of the restorations done on either surfaces statistically.

  12. On Two Kinds of Differential Operators on General Smooth Surfaces

    CERN Document Server

    Xie, Xi-Lin

    2013-01-01

    Two kinds of differential operators that can be generally defined on an arbitrary smooth surface in a finite dimensional Euclid space are studied, one is termed as surface gradient and the other one as Levi-Civita gradient. The surface gradient operator is originated from the differentiability of a tensor field defined on the surface. Some integral and differential identities have been theoretically studied that play the important role in the studies on continuous mediums whose geometrical configurations can be taken as surfaces and on interactions between fluids and deformable boundaries. The definition of Levi-Civita gradient is based on Levi-Civita connections generally defined on Riemann manifolds. It can be used to set up some differential identities in the intrinsic/coordiantes-independent form that play the essential role in the theory of vorticity dynamics for two dimensional flows on general fixed smooth surfaces.

  13. E-Polytopes in Picard Groups of Smooth Rational Surfaces

    Directory of Open Access Journals (Sweden)

    Jae-Hyouk Lee

    2016-04-01

    Full Text Available In this article, we introduce special divisors (root, line, ruling, exceptional system and rational quartic in smooth rational surfaces and study their correspondences to subpolytopes in Gosset polytopes k 21 . We also show that the sets of rulings and exceptional systems correspond equivariantly to the vertices of 2 k 1 and 1 k 2 via E-type Weyl action.

  14. Modelling free surface flows with smoothed particle hydrodynamics

    Directory of Open Access Journals (Sweden)

    L.Di G.Sigalotti

    2006-01-01

    Full Text Available In this paper the method of Smoothed Particle Hydrodynamics (SPH is extended to include an adaptive density kernel estimation (ADKE procedure. It is shown that for a van der Waals (vdW fluid, this method can be used to deal with free-surface phenomena without difficulties. In particular, arbitrary moving boundaries can be easily handled because surface tension is effectively simulated by the cohesive pressure forces. Moreover, the ADKE method is seen to increase both the accuracy and stability of SPH since it allows the width of the kernel interpolant to vary locally in a way that only the minimum necessary smoothing is applied at and near free surfaces and sharp fluid-fluid interfaces. The method is robust and easy to implement. Examples of its resolving power are given for both the formation of a circular liquid drop under surface tension and the nonlinear oscillation of excited drops.

  15. Recovering Epipolar Geometry from Images of Smooth Surfaces

    CERN Document Server

    Kupervasser, Oleg

    2011-01-01

    We present four methods for recovering the epipolar geometry from images of smooth surfaces. Existing methods for recovering epipolar geometry use corresponding feature points that cannot be found in such images. The first method is based on finding corresponding characteristic points created by illumination (ICPM - illumination characteristic points method). The second method is based on correspondent tangency points created by tangents from epipoles to outline of smooth bodies (OTPM - outline tangent points method). These two methods are exact and give correct results for real images, because positions of the corresponding illumination characteristic points and corresponding outline are known with small errors. But the second method is limited either to special type of scenes or to restricted camera motion. We also consider two else methods, termed CCPM (curve characteristic points method) and CTPM (curve tangent points method), for search epipolar geometry for images of smooth bodies based on a set of leve...

  16. Smooth surface glass ionomer restoration for primary teeth.

    Science.gov (United States)

    Killian, C M; Croll, T P

    1991-01-01

    Glass ionomer restorative cement offers the clinician an alternative to bonded composite resin for restoration of certain lesions in primary teeth. This article details a step-by-step procedure for restoration of a smooth surface carious lesion in a primary incisor using an encapsulated glass ionomer restorative material and reviews advantages and limitations of the cement. A light-hardened glass ionomer liner/base that has proven useful as an enamel and dentin restorative is also described.

  17. Highly smooth Nb surfaces fabricated by buffered electropolishing

    Energy Technology Data Exchange (ETDEWEB)

    Andy T. Wu; John Mammossor; H. Phillips; Jean Delayen; Charles Reece; Amy Wilkerson; David Smith; Robert Ike

    2005-05-01

    It is demonstrated that highly smooth Nb surfaces can be obtained through Buffered ElectroPolishing (BEP) employing an electrolyte consisting of lactic, sulfuric, and hydrofluoric acids. Parameters that control the polishing process are optimized to achieve the smoothest surface finish with the help of surface observations using a scanning electron microscope and a Metallographic Optical Microscope (MOM). The polishing rate of BEP is determined to be 0.646 {micro}m/min that is much higher than 0.381 {micro}m/min achieved by the conventional ElectroPolishing (EP) process widely used in the Superconducting Radio Frequency (SRF) community. A high precision and large scan area 3-D profilometer is used to view morphology of the treated Nb surfaces. Statistical data, such as, rms, total indicator runout, and arithmetic mean deviation of the Nb surfaces are extracted from the profilometer images. It is found that Nb surfaces treated by BEP are an order of magnitude smoother than those treated by the optimized EP process. The chemical composition of the Nb surfaces after BEP is analyzed by static and dynamic Secondary Ion Mass Spectrometer (SIMS) systems. Cracking patterns of the Nb surfaces under different primary ion sources of Ga{sup +}, Au{sup +}, and Ar{sup +} are reported. The depth profile of the surface niobium oxides is studied through continuously monitoring niobium and its relevant oxides' peaks as a function of time. Dynamic SIMS results imply that the surface oxide structure of Nb may be more complicated than what usually believed and can be inhomogeneous. Preliminary results of BEP on Nb SRF single cell cavities and half-cells are reported. It is shown that smooth and bright surfaces can be obtained in 30 minutes when the electric field inside a SRF cavity is uniform during a BEP process. This study reveals that BEP is a highly promising technique for surface treatment on Nb SRF cavities to be used in particle accelerators.

  18. Isophotes on a smooth surface related to scene geometry

    Science.gov (United States)

    Mamassian, Pascal

    1993-06-01

    It is shown, through elementary differential geometry, how the shape of the isophotes on a smooth surface is related to the underlying object and the location of the light source. Taking advantage of the principal directions, several characteristics of the isophotes are expressed, among which the geodesic curvature is emphasized. From these results, a variational method is discussed to estimate the surface shape from the image irradiance, subject to a geodesicity constraint on the isophotes. Finally, a local solid shape characteristic based on the principal curvatures ratio is offered.

  19. Smooth Surfaces: A review of current and planned smooth surface technologies for fouling resistance in boiler

    Energy Technology Data Exchange (ETDEWEB)

    Corkery, Robert; Baefver, Linda; Davidsson, Kent; Feiler, Adam

    2012-02-15

    Here we have described the basics of boilers, fuels, combustion, flue gas composition and mechanisms of deposition. We have reviewed coating technologies for boiler tubes, including their materials compositions, nano structures and performances. The surface forces in boilers, in particular those relevant to formation of unwanted deposits in boilers have also been reviewed, and some comparative calculations have been included to indicate the procedures needed for further study. Finally practical recommendations on the important considerations in minimizing deposition on boiler surfaces are made

  20. Autocalibrating Tiled Projectors on Piecewise Smooth Vertically Extruded Surfaces.

    Science.gov (United States)

    Sajadi, Behzad; Majumder, Aditi

    2011-09-01

    In this paper, we present a novel technique to calibrate multiple casually aligned projectors on fiducial-free piecewise smooth vertically extruded surfaces using a single camera. Such surfaces include cylindrical displays and CAVEs, common in immersive virtual reality systems. We impose two priors to the display surface. We assume the surface is a piecewise smooth vertically extruded surface for which the aspect ratio of the rectangle formed by the four corners of the surface is known and the boundary is visible and segmentable. Using these priors, we can estimate the display's 3D geometry and camera extrinsic parameters using a nonlinear optimization technique from a single image without any explicit display to camera correspondences. Using the estimated camera and display properties, the intrinsic and extrinsic parameters of each projector are recovered using a single projected pattern seen by the camera. This in turn is used to register the images on the display from any arbitrary viewpoint making it appropriate for virtual reality systems. The fast convergence and robustness of this method is achieved via a novel dimension reduction technique for camera parameter estimation and a novel deterministic technique for projector property estimation. This simplicity, efficiency, and robustness of our method enable several coveted features for nonplanar projection-based displays. First, it allows fast recalibration in the face of projector, display or camera movements and even change in display shape. Second, this opens up, for the first time, the possibility of allowing multiple projectors to overlap on the corners of the CAVE-a popular immersive VR display system. Finally, this opens up the possibility of easily deploying multiprojector displays on aesthetic novel shapes for edutainment and digital signage applications.

  1. A theory of static friction between homogeneous surfaces based on compressible elastic smooth microscopic inclines

    CERN Document Server

    Thun, Freeman Chee Siong; Chan, Kin Sung

    2014-01-01

    We develop a theory of static friction by modeling the homogeneous surfaces of contact as being composed of a regular array of compressible elastic smooth microscopic inclines. Static friction is thought of as the resistance due to having to push the load over these smooth microscopic inclines that share a common inclination angle. As the normal force between the surfaces increases, the microscopic inclines would be compressed elastically. Consequently, the coefficient of static friction does not remain constant but becomes smaller for a larger normal force, since the load would then only need to be pushed over smaller angles. However, a larger normal force would also increase the effective compressed area between the surfaces, as such the pressure is distributed over this larger effective compressed area. The relationship between the normal force and the common angle is therefore non-linear. Overall, static friction is shown to depend on the normal force, apparent contact area, Young's modulus, and the compr...

  2. Surface smoothness and marginal fit with phosphate-bonded investments.

    Science.gov (United States)

    Cooney, J P; Doyle, T M; Caputo, A A

    1979-04-01

    Two phosphate-bonded investments and one calcium sulfate investment were evaluated for the surface smoothness and marginal fit they impart to gold castings. A modified technique was also evaluated for each phosphate-bonded investment, where the silica sol was not diluted and the spatulation time was reduced. The results of this study lead to the following conclusions: 1. The marginal fits obtained with all four phosphate-bonded methods were comparable to each other and superior to that obtained with the calcium sulfate investment. 2. The presence of nodules on the surface of the castings was more prevalent with the phosphate-bonded investments. However, this effect was not statistically significant. 3. Clinical assessment of the roughness of the castings revealed that all the methods tested produced clinically acceptable castings. 4. Visual observation by five dentists revealed that both the recommended and modified techniques for one of the phosphate-bonded investments (Ceramigold) produced a smoother surface than any other investment tested. Rating of scanning electron microscope photographs (X600) revealed no difference in the surface roughness between any of the castings. Consequently, no definitive relation between investment type or technique and surface roughness was established. 5. No correlation was demonstrated between surface roughness, as evaluated by either clinical observation or scanning electron microscope photography, and marginal fit of the castings.

  3. Feature-preserving surface mesh smoothing via suboptimal Delaunay triangulation.

    Science.gov (United States)

    Gao, Zhanheng; Yu, Zeyun; Holst, Michael

    2013-01-01

    A method of triangular surface mesh smoothing is presented to improve angle quality by extending the original optimal Delaunay triangulation (ODT) to surface meshes. The mesh quality is improved by solving a quadratic optimization problem that minimizes the approximated interpolation error between a parabolic function and its piecewise linear interpolation defined on the mesh. A suboptimal problem is derived to guarantee a unique, analytic solution that is significantly faster with little loss in accuracy as compared to the optimal one. In addition to the quality-improving capability, the proposed method has been adapted to remove noise while faithfully preserving sharp features such as edges and corners of a mesh. Numerous experiments are included to demonstrate the performance of the method.

  4. Scattering of mid-IR-range surface electromagnetic waves by optically smooth metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bonch-Bruevich, A.M.; Libenson, M.N.; Makin, V.S.; Pudkov, S.D.; Trubaev, V.V.

    1985-09-01

    The paper reports the experimental observation of the intense scattering of surface electromagnetic waves with a wavelength of 10.6 microns excited on an optically smooth metal surface with a residual roughness having a mean square height of less than 25 A. A method for determining the attenuation of surface electromagnetic waves is proposed, and a test of the method is reported which involves the measurement of the relative intensity of the local scattering of the waves along their path. 9 references.

  5. Computer simulation of rolling wear on bionic non-smooth convex surfaces

    Institute of Scientific and Technical Information of China (English)

    HAN Zhi-wu; LIU Zu-bin; YANG Zhuo-juan; YAN Yu-ying; REN Lu-quan

    2004-01-01

    The study of bionics has found that the skins of many burrow animals which live in soil and stone conditions have an anti wear function, and which is related to their body surfaces' non-smooth morphology. In the present study, bionic non-smooth surfaces are used in roll surface design, and roll models with convex non-smooth surfaces are developed. The rolling wear of non-smooth roll in steel rolling is simulated by the FEM software-ANSYS. The equivalent stress, the node friction stress, and the node contact pressure between the roll and the rolling piece are calculated; and the anti-wear mechanism is analyzed.

  6. Nonabelian Jacobian of smooth projective surfaces and representation theory

    CERN Document Server

    Reider, Igor

    2011-01-01

    The paper studies representation theoretic aspects of a nonabelian version of the Jacobian for a smooth complex projective surface $X$ introduced in [R1]. The sheaf of reductive Lie algebras $\\bf\\calG$ associated to the nonabelian Jacobian is determined and its Lie algebraic properties are explicitly related to the geometry of configurations of points on $X$. In particular, it is shown that the subsheaf of centers of $\\bf\\calG$ determines a distinguished decomposition of configurations into the disjoint union of subconfigurations. Furthermore, it is shown how to use $sl_2$-subalgebras associated to certain nilpotent elements of $\\bf\\calG$ to write equations defining con?figurations of $X$ in appropriate projective spaces. The same nilpotent elements are used to establish a relation of the nonabelian Jacobian with such fundamental objects in the representation theory as nilpotent orbits, Springer resolution and Springer fibres of simple Lie algebras of type $A_n$, for appropriate values of $n$. This leads to a...

  7. The global ring of a smooth projective surface

    Directory of Open Access Journals (Sweden)

    Salvatore Giuffrida

    2000-05-01

    Full Text Available Let X be a smooth projective variety over an algebraically closed field k. We associate to X , in a functorial way, a multigraded k-algebra G(X, called the global ring of X . We find some results when dim X = 2, and we explicitly determine the global ring in two particular cases.

  8. Differential topology of complex surfaces elliptic surfaces with p g=1 smooth classification

    CERN Document Server

    Morgan, John W

    1993-01-01

    This book is about the smooth classification of a certain class of algebraicsurfaces, namely regular elliptic surfaces of geometric genus one, i.e. elliptic surfaces with b1 = 0 and b2+ = 3. The authors give a complete classification of these surfaces up to diffeomorphism. They achieve this result by partially computing one of Donalson's polynomial invariants. The computation is carried out using techniques from algebraic geometry. In these computations both thebasic facts about the Donaldson invariants and the relationship of the moduli space of ASD connections with the moduli space of stable bundles are assumed known. Some familiarity with the basic facts of the theory of moduliof sheaves and bundles on a surface is also assumed. This work gives a good and fairly comprehensive indication of how the methods of algebraic geometry can be used to compute Donaldson invariants.

  9. Non-Smooth Morphologies of Typical Plant Leaf Surfaces and Their Anti-Adhesion Effects

    Institute of Scientific and Technical Information of China (English)

    Lu-quan Ren; Shu-jie Wang; Xi-mei Tian; Zhi-wu Han; Lin-na Yan; Zhao-mei Qiu

    2007-01-01

    The micromorphologies of surfaces of several typical plant leaves were investigated by scanning electron microscopy(SEM).Different non-smooth surface characteristics were described and classified.The hydrophobicity and anti-adhesion of non-smooth leaf surfaces were quantitatively measured.Results show that the morphology of epidermal cells and the morphology and distribution density of epicuticular wax directly affect the hydrophobicity and anti-adhesion.The surface with uniformly distributed convex units shows the best anti-adhesion,and the surface with regularly arranged trellis units displays better anti-adhesion.In contrast,the surface with randomly distributed hair units performs relatively bad anti-adhesion.The hydrophobic models of papilla-ciliary and fold-setal non-smooth surfaces were set up to determine the impacts of geometric parameters on the hydrophobicity.This study may provide an insight into surface machine molding and apparent morphology design for biomimetics engineering.

  10. Three-Dimensional Smoothed Particle Hydrodynamics Simulation for Liquid Droplet with Surface Tension

    OpenAIRE

    Terissa, Hanifa; Barecasco, Agra; Naa, Christian Fredy

    2013-01-01

    We provide a basic method of Smoothed Particle Hydrodynamics (SPH) to simulate liquid droplet with surface tension in three dimensions. Liquid droplet is a simple case for surface tension modeling. Surface tension works only on fluid surface. In SPH method, we simply apply the surface tension on the boundary particles of liquid. The particle on the 3D boundary was detected dynamically using Free-Surface Detection algorithm. The normal vector and curvature of the boundary surface were calculat...

  11. Damage Mechanism in Counter Pairs Caused by Bionic Non-smoothed Surface

    Directory of Open Access Journals (Sweden)

    ZHANG Zhan-hui

    2016-08-01

    Full Text Available Four biomimetic non-smoothed surface specimens with different shapes were prepared by laser processing. Tests were conducted on MMU-5G wear and abrasion test machine to study the influencing rule of non-smoothed surfaces on counter pairs. The results show that the mass loss of the friction pair matching with the non-smoothed units is much greater than the ones matching with the smooth specimens. The pairs matching with different non-smoothed units suffer differently. The non-smoothed surface protruding zone exerts micro cutting on counter pairs. The striation causes the greatest mass loss of the pairs than the other non-smoothed units, which almost doubles the damage of the grid ones suffering the least. The difference in pairs damage is attributed to the different mechanism of undertaking the load in the process of wear. The damage can be alleviated effectively by changing the shapes of the units without increasing or decreasing the area ratio of the non-smoothed units.

  12. Effect of interaction of embedded crack and free surface on remaining fatigue life

    Directory of Open Access Journals (Sweden)

    Genshichiro Katsumata

    2016-12-01

    Full Text Available Embedded crack located near free surface of a component interacts with the free surface. When the distance between the free surface and the embedded crack is short, stress at the crack tip ligament is higher than that at the other area of the cracked section. It can be easily expected that fatigue crack growth is fast, when the embedded crack locates near the free surface. To avoid catastrophic failures caused by fast fatigue crack growth at the crack tip ligament, fitness-for-service (FFS codes provide crack-to-surface proximity rules. The proximity rules are used to determine whether the cracks should be treated as embedded cracks as-is, or transformed to surface cracks. Although the concepts of the proximity rules are the same, the specific criteria and the rules to transform embedded cracks into surface cracks differ amongst FFS codes. This paper focuses on the interaction between an embedded crack and a free surface of a component as well as on its effects on the remaining fatigue lives of embedded cracks using the proximity rules provided by the FFS codes. It is shown that the remaining fatigue lives for the embedded cracks strongly depend on the crack aspect ratio and location from the component free surface. In addition, it can be said that the proximity criteria defined by the API and RSE-M codes give overly conservative remaining lives. On the contrary, the WES and AME codes always give long remaining lives and non-conservative estimations. When the crack aspect ratio is small, ASME code gives non-conservative estimation.

  13. Surface morphology evolution during plasma etching of silicon: roughening, smoothing and ripple formation

    Science.gov (United States)

    Ono, Kouichi; Nakazaki, Nobuya; Tsuda, Hirotaka; Takao, Yoshinori; Eriguchi, Koji

    2017-10-01

    Atomic- or nanometer-scale roughness on feature surfaces has become an important issue to be resolved in the fabrication of nanoscale devices in industry. Moreover, in some cases, smoothing of initially rough surfaces is required for planarization of film surfaces, and controlled surface roughening is required for maskless fabrication of organized nanostructures on surfaces. An understanding, under what conditions plasma etching results in surface roughening and/or smoothing and what are the mechanisms concerned, is of great technological as well as fundamental interest. In this article, we review recent developments in the experimental and numerical study of the formation and evolution of surface roughness (or surface morphology evolution such as roughening, smoothing, and ripple formation) during plasma etching of Si, with emphasis being placed on a deeper understanding of the mechanisms or plasma–surface interactions that are responsible for. Starting with an overview of the experimental and theoretical/numerical aspects concerned, selected relevant mechanisms are illustrated and discussed primarily on the basis of systematic/mechanistic studies of Si etching in Cl-based plasmas, including noise (or stochastic roughening), geometrical shadowing, surface reemission of etchants, micromasking by etch inhibitors, and ion scattering/chanelling. A comparison of experiments (etching and plasma diagnostics) and numerical simulations (Monte Carlo and classical molecular dynamics) indicates a crucial role of the ion scattering or reflection from microscopically roughened feature surfaces on incidence in the evolution of surface roughness (and ripples) during plasma etching; in effect, the smoothing/non-roughening condition is characterized by reduced effects of the ion reflection, and the roughening-smoothing transition results from reduced ion reflections caused by a change in the predominant ion flux due to that in plasma conditions. Smoothing of initially rough

  14. An in vitro study to identify a ceramic polishing protocol effecting smoothness superior to glazed surface.

    Science.gov (United States)

    Manjuran, Noxy George; Sreelal, T

    2014-09-01

    Polishing is taken up as an alternative to reglazing after adjustments of glazed ceramic prosthesis. An in vitro study was carried out to evaluate three different ceramic polishing systems and their combinations to identify a method that would achieve surface smoothness superior to the glazed surface. 77 glazed feldspathic porcelain disc surfaces, of diameter 12.5 mm and thickness 2 mm were constituted into seven groups of 11 specimen surfaces each. The glazed surfaces in the first group served as control (C). They were not subjected to deglazing or polishing. The remaining 66 surfaces underwent deglazing. The deglazed surfaces in the second group (D) were retained as such and did not undergo polishing. The deglazed surfaces in the third group (Wh), were polished using a polishing wheel (CeraMaster). In the fourth group (K), an adjustment kit (Porcelain Adjustment kit) was used for polishing the deglazed surfaces. The fifth group (Wx) was polished with diamond particle-impregnated wax (Dura-Polish Dia). In all these three groups, polishing was done for 40 s. The deglazed surfaces of the sixth group (WhWx) were polished initially with polishing wheel for 40 s and then with diamond particle-impregnated wax for 40 s. In the seventh group (KWx), the deglazed surfaces were polished with an adjustment kit (Porcelain Adjustment kit) for 40 s followed by diamond particle-impregnated wax (Dura-Polish Dia) for 40 s. In the sixth and seventh groups, the total polishing time was 80 s each. From each group, one specimen was set aside for scanning electron microscopy (SEM). The remaining ten specimens in each group underwent colorimetry and profilometry. Colorimeter (Minolta CR-200b ChromaMeter; Minolta, Osaka, Japan) was used to measure parameters according to CIE L*a*b* colour system and colour difference (ΔE) between control and other groups were calculated. Profilometer (Talysurf CLI 2000) was used to measure the surface roughness (Ra). The data were statistically

  15. Adhesion of smooth and rough phenotypes of Flavobacterium psychrophilum to polystyrene surfaces.

    Science.gov (United States)

    Högfors-Rönnholm, E; Norrgård, J; Wiklund, T

    2015-05-01

    Phenotypic smooth cells of the fish pathogenic bacterium Flavobacterium psychrophilum have previously been reported to be more adhesive to polystyrene surfaces than corresponding rough cells. In this study, the adhesion ability of smooth and rough cells of F. psychrophilum to polystyrene surfaces was investigated in detail with a crystal violet staining method. By treating both polystyrene surfaces with fish mucus and carbohydrates and the bacterial cells with carbohydrates, the involvement of lectins in the adhesion process was investigated. Smooth cells showed significantly higher adhesion ability to untreated polystyrene surfaces compared with corresponding rough cells and increasing water hardness had an inhibitory effect on the adhesion. Treatment of polystyrene surfaces with D-glucose, D-galactose and fish mucus increased the adhesion ability of smooth cells to polystyrene. Furthermore, treatment of the smooth cells with D-glucose, D-galactose and sialic acid decreased the adhesion ability of the cells, indicating that the adhesion is likely mediated by complementary lectins on the surface of the cells. Sodium (meta)periodate treatment of smooth cells also decreased the adhesion ability to polystyrene, suggesting that the lectins, such as the dominating sialic acid-binding lectin, are probably localized in the extracellular polysaccharides surrounding the cells.

  16. 3D description of particle detachment from a smooth surface

    Science.gov (United States)

    Liberzon, Alex; Traugott, Hadar; International CollaborationTurbulence Research Collaboration

    2011-11-01

    This study explores the necessary turbulent flow conditions for initial entrainment of particles from smooth beds into zero-mean-shear flow in an oscillating grid chamber as compared to the bounded shear flow created in a lid-driven cavity. The experiments are not designed to fully mimic the real problem of sediment transport but rather identify key mechanisms, utilizing direct observation and quantification of particle motion at the beginning, during and after lift-off. In both turbulent flows, particle image velocimetry (PIV) and three-dimensional particle tracking velocimetry (3D-PTV) are used to determine the properties of turbulent flows and to track the movement of individual particles through the various phases of the resuspension. The combination of the experimental methods allow to correlate in a quantitative manner the flow conditions responsible for rolling, pick-up, detachment and re-entrainment of particles. The study is supported by the Israel Science Foundation under grant 782/08.

  17. Anisotropism of the Non-Smooth Surface of Butterfly Wing

    Institute of Scientific and Technical Information of China (English)

    Gang Sun; Yan Fang; Qian Cong; Lu-quan Ren

    2009-01-01

    Twenty-nine species of butterflies were collected for observation and determination of the wing surfaces using a Scanning Electron Microscope (SEM). Butterfly wing surface displays structural anisotropism in micro-, submicro- and nano-scales. The scales on butterfly wing surface arrange like overlapping roof tiles. There are submicrometric vertical gibbosities, horizontal links, and nano-protuberances on the scales. First-incline-then-drip method and first-drip-then-incline method were used to measure the Sliding Angle (SA) of droplet on butterfly wing surface by an optical Contact Angle (CA) measuring system.Relatively smaller sliding angles indicate that the butterfly wing surface has fine self-cleaning property. Significantly different SAs in various directions indicate the anisotropic self-cleaning property of butterfly wing surface. The SAs on the butterfly wing surface without scales are remarkably larger than those with scales, which proves the crucial role of scales in determining the self-cleaning property. Butterfly wing surface is a template for design and fabrication of biomimetic materials and self-cleaning substrates. This work may offer insights into how to design directional self-cleaning coatings and anisotropic wetting surface.

  18. Martian airfall dust on smooth, inclined surfaces as observed on the Phoenix Mars Lander telltale mirror

    Science.gov (United States)

    Moores, John E.; Ha, Taesung; Lemmon, Mark T.; Gunnlaugsson, Haraldur Páll

    2015-10-01

    The telltale mirror, a smooth inclined surface raised over 1 m above the deck of the Phoenix Mars Lander, was observed by the Surface Stereo Imager (SSI) several times per sol during the Phoenix Mars Lander mission. These observations were combined with a radiative transfer model to determine the thickness of dust on the wind telltale mirror as a function of time. 239 telltale sequences were analyzed and dustiness was determined on a diurnal and seasonal basis. The thickness of accumulated dust did not follow any particular diurnal or seasonal trend. The dust thickness on the mirror over the mission was 0.82±0.39 μm, which suggests a similar thickness to the modal scattering particle diameter. This suggests that inclining a surface beyond the angle of repose and polishing it to remove surface imperfections is an effective way to mitigate the accumulation of dust to less than a micron over a wide range of meteorological conditions and could be beneficial for surfaces which can tolerate some dust but not thick accumulations, such as solar panels. However, such a surface will not remain completely dust free through this action alone and mechanical or electrical clearing must be employed to remove adhered dust if a pristine surface is required. The single-scattering phase function of the dust on the mirror was consistent with the single-scattering phase function of martian aerosol dust at 450 nm, suggesting that this result is inconsistent with models of the atmosphere which require vertically or horizontally separated components or broad size distributions to explain the scattering behavior of these aerosols in the blue. The single-scattering behavior of the dust on the mirror is also consistent with Hapke modeling of spherical particles. The presence of a monolayer of particles would tend to support the spherical conclusion: such particles would be most strongly adhered electrostatically.

  19. Over rough and smooth : Amputee gait on an irregular surface

    NARCIS (Netherlands)

    Curtze, C.; Hof, A.L.; Postema, K.; Otten, B.

    2011-01-01

    When negotiating irregular surfaces, the control of dynamic stability is challenged. In this study, we compared the adjustments in stepping behaviour and arm-swing of 18 unilateral transtibial amputees and 17 able-bodied participants when walking on flat and irregular surfaces. Experimental findings

  20. Experiment about Drag Reduction of Bionic Non-smooth Surface in Low Speed Wind Tunnel

    Institute of Scientific and Technical Information of China (English)

    Tian Li-mei; Ren Lu-quan; Han Zhi-wu; Zhang Shi-cun

    2005-01-01

    The body surface of some organisms has non-smooth structure, which is related to drag reduction in moving fluid. To imitate these structures, models with a non-smooth surface were made. In order to find a relationship be tween drag reduction and the non-smooth surface, an orthogonal design test was employed in a low speed wind tunnel. Six factors likely to influence drag reduction were considered, and each factor tested at three levels. The six factors were the configuration, diameter/bottom width, height/depth, distribution, the arrangement of the rough structures on the experimental model and the wind speed. It was shown that the non-smooth surface causes drag reduction and the distribution of non-smooth structures on the model, and wind speed, are the predominant factors affecting drag reduction. Using analysis of variance, the optimal combination and levels were obtained, which were a wind speed of 44 m/s, distribution of the non-smooth structure on the tail of the experimental model, the configuration of riblets, diameter/bottom width of 1 mm, height/depth of 0.5 mm, arranged in a rhombic formation. At the optimal combination mentioned above, the 99% confidence interval for drag reduction was 11.13 % to 22.30%.

  1. Diagnosis of osteoarthritis by cartilage surface smoothness quantified automatically from knee MRI

    DEFF Research Database (Denmark)

    Tummala, Sudhakar; Bay-Jensen, Anne-Christine; Karsdal, Morten A.

    2011-01-01

    Objective: We investigated whether surface smoothness of articular cartilage in the medial tibiofemoral compartment quantified from magnetic resonance imaging (MRI) could be appropriate as a diagnostic marker of osteoarthritis (OA). Method: At baseline, 159 community-based subjects aged 21 to 81......, specifically cartilage volume from MRI, joint space width (JSW) from radiographs, and pain scores. Results: A total of 140 subjects concluded the 21-month study. Cartilage smoothness provided diagnostic ability in all compartments (P ... with pain severity (e.g., r = -0.32). The longitudinal change in smoothness was correlated with cartilage loss (r up to 0.60, P radiographic OA. Furthermore...

  2. Design Principles of the Non-smooth Surface of Bionic Plow Moldboard

    Institute of Scientific and Technical Information of China (English)

    Luquan Ren; Shiqiao Deng; Jingchun Wang; Zhiwu Han

    2004-01-01

    The diverse non-smooth body surfaces to reduce soil adhesion are the evolutional results for the soil animals to fit the adhesive and wet environment and can be used as a biological basis for the design of bionic plow moldboard. The model surfaces for bionic simulation should be taken from soil animal digging organs, on which the soil motion is similar to what is on the surface of moldboard. By analyzing the distribution of non-smooth units on the body surface of the ground beetle jaw and the soil moving stresses, the design principles of the bionic moldboard for the local and the whole moldboard were presented respectively. As well, the effect of soil moving speed on reducing adhesion, the dimensions relationship between soil particles and non-smooth convexes, the relationship between the enveloping surface of non-smooth convexes and the initial smooth surface of the plow body, and the convex types of the sphere coronal and the pangolin scales, etc. were discussed.

  3. Analysis of the Contact Area of Smooth and Rough Surfaces in Contact with Sphere Indenter Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Kartini

    2016-01-01

    Full Text Available This paper analyzes the contact area of the contact between a deformable rough surface (smooth and rough and a hard smooth sphere indenter using finite element method. A method was introduced to generate a three dimensional rough surfaces using Computer Aided Design (CAD software. The rough surface model was developed based on the surface measurement data, while the smooth surface model was generated from the CAD software. Contact area and contact deformation were analyzed. Results showed that the contact area between rough surface versus sphere and smooth surface versus sphere is different.

  4. Chemical milling solution produces smooth surface finish on aluminum

    Science.gov (United States)

    Lorenzen, H. C.

    1966-01-01

    Elementary sulfur mixed into a solution of caustic soda and salts produces an etchant which will chemically mill end-grain surfaces on aluminum plate. This composition results in the least amount of thickness variation and pitting.

  5. Increased Wear Resistance of Surfaces of Rotation Bearings Methods Strengthening-Smoothing Processing

    OpenAIRE

    2016-01-01

    International audience; Trends of modern engineering put forward higher requirements for quality bearings. This is especially true on production of bearings for special purposes with high speeds of rotation and resource. Much more opportunities in the technology management quality surface layers appear in the application of smoothing-strengthening methods, based on superficial plastic deformation. Working models of cutting lathes, grinders and tool smoothing sequence revealed the formation of...

  6. Volume radiation generated by a medium-IR SEW propagating on a smooth metal surface

    Energy Technology Data Exchange (ETDEWEB)

    Libenson, M.N.; Makin, V.S.; Trubaev, V.V. [Vavilov State Optical Inst., St. Petersburg (Russian Federation)

    1995-03-01

    The volume wave radiating from a smooth surface region that guides an SEW is shown to be a grazing wave; in earlier experiments, this wave was detected at relatively large angles with respect to the surface. 4 refs., 2 figs., 1 tab.

  7. Human Coronavirus 229E Remains Infectious on Common Touch Surface Materials.

    Science.gov (United States)

    Warnes, Sarah L; Little, Zoë R; Keevil, C William

    2015-11-10

    The evolution of new and reemerging historic virulent strains of respiratory viruses from animal reservoirs is a significant threat to human health. Inefficient human-to-human transmission of zoonotic strains may initially limit the spread of transmission, but an infection may be contracted by touching contaminated surfaces. Enveloped viruses are often susceptible to environmental stresses, but the human coronaviruses responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) have recently caused increasing concern of contact transmission during outbreaks. We report here that pathogenic human coronavirus 229E remained infectious in a human lung cell culture model following at least 5 days of persistence on a range of common nonbiocidal surface materials, including polytetrafluoroethylene (Teflon; PTFE), polyvinyl chloride (PVC), ceramic tiles, glass, silicone rubber, and stainless steel. We have shown previously that noroviruses are destroyed on copper alloy surfaces. In this new study, human coronavirus 229E was rapidly inactivated on a range of copper alloys (within a few minutes for simulated fingertip contamination) and Cu/Zn brasses were very effective at lower copper concentration. Exposure to copper destroyed the viral genomes and irreversibly affected virus morphology, including disintegration of envelope and dispersal of surface spikes. Cu(I) and Cu(II) moieties were responsible for the inactivation, which was enhanced by reactive oxygen species generation on alloy surfaces, resulting in even faster inactivation than was seen with nonenveloped viruses on copper. Consequently, copper alloy surfaces could be employed in communal areas and at any mass gatherings to help reduce transmission of respiratory viruses from contaminated surfaces and protect the public health. Respiratory viruses are responsible for more deaths globally than any other infectious agent. Animal coronaviruses that "host jump" to humans result in

  8. Injection Induced Mixing in Flows Separating From Smooth Surfaces

    Science.gov (United States)

    Adamczyk, John J. (Technical Monitor); Wundrow, David W.

    2004-01-01

    An analytic model for predicting the effect of unsteady local surface injection on the flow separating from a streamlined body at angle of attack is proposed. The model uses the premise that separation control results from enhanced mixing along the shear layer that develops between the main stream and the fluid in the underlying recirculation zone. High-Reynolds-number asymptotic methods are used to connect the unsteady surface injection to an instability wave propagating on the separating shear layer and then to the large-scale coherent structures that produce the increased mixing. The results is a tool that can guide the choice of fluid-actuator parameters to maximize flow-control effectiveness and may also facilitate computer-based numerical experiments.

  9. Effects of smooth random surface on fluid monolayer thermodynamics

    Science.gov (United States)

    Khlyupin, A. N.

    2016-11-01

    We consider the lattice gas approach to statistical mechanics of fluid adsorbed on random surfaces with fluid-fluid and fluid-surface potentials. It was shown that effective Hamiltonian contains quenched random interactions and random site fields. Their statistical features combine the properties of random geometry and fluid-fluid pair interaction potential. The high-temperature expansion leads to infinite-ranged random field model and Sherrington-Kirkpatrick spin-glass model. Thermodynamic properties are evaluated using replica theory procedure widely used to analyze quenched disorder systems. On the other hand we consider the random field model in random graph with finite connectivity instead of previous “infinite-ranged” approximations. This model has been investigated using finite connectivity technique. The replica symmetry ansatz for the order function is expressed in terms of an effective-field distribution. Analysis of random geometry effects on thermodynamic properties in such approach was done for the first time.

  10. Smooth connection method of segment test data in road surface profile measurement

    Science.gov (United States)

    Duan, Hu-Ming; Ma, Ying; Shi, Feng; Zhang, Kai-Bin; Xie, Fei

    2012-01-01

    It's reviewed that the measurement system of road surface profile and the calculation method of segment road test data have been introduced. Because of there are sudden vertical steps at the connection points of segment data which will influence the application of road surface data in automotive engineering. So a new smooth connection method of segment test data is proposed which revised the sudden vertical steps connection by the Signal Local Baseline Adjustment (SLBA) method. Besides, there is an actual example which mentioned the detailed process of the smooth connection of segment test data by the SLBA method and the adjusting results at these connection points. The application and calculation results show that the SLBA method is simple and has achieved obvious effect in smooth connection of the segment road test data. The method of SLBA can be widely applied to segment road surface data processing or the long period vibration signal processing.

  11. Review of applications and surface smoothing mechanisms of optical waveguide devices

    Directory of Open Access Journals (Sweden)

    Haiquan TANG

    2017-02-01

    Full Text Available Optical waveguide devices are widely used in many fields and have good development prospects. But surface roughness of waveguide device induces a passive effect on the light transmission loss and the Q value of ring cavity, which restricts the development and applications of optical waveguide devices. Currently, the common used surface and side wall smoothing methods for waveguide devices are the thermal oxidation method, laser beam method, and hydrogen annealing method, and the surface hydrogen annealing method has better smoothing effect. However, the mechanism of hydrogen annealing method is still not clear so far, thus the experimental parameters cannot be further optimized to obtain optimal experimental result. Based on the review of the contents mentioned above, the hydrogen annealing mechanism is primarily studied through the simulation analysis by Materials Studio, which provides theoretical foundation and guidance for smoothing of waveguide device by hydrogen annealing technology.

  12. CLOSED SMOOTH SURFACE DEFINED FROM CUBIC TRIANGULAR SPLINES

    Institute of Scientific and Technical Information of China (English)

    Ren-zhong Feng; Ren-hong Wang

    2005-01-01

    In order to construct closed surfaces with continuous unit normal, we introduce a new spline space on an arbitrary closed mesh of three-sided faces. Our approach generalizes an idea of Goodman and is based on the concept of 'Geometric continuity' for piecewise polynomial parametrizations. The functions in the spline space restricted to the faces are cubic triangular polynomials. A basis of the spline space is constructed of positive functions which sum to 1. It is also shown that the space is suitable for interpolating data at the midpoints of the faces.

  13. Invariant Geometric Evolutions of Surfaces and Volumetric Smoothing

    Science.gov (United States)

    1994-04-15

    curves on surfaces, Part II. Intersections, blow-up, and generalized solutions," Annals of Mathematics 133, pp. 171-215, 1991. [7] S. Angenent, "Some...1-67, 1992. [19] K.-Ecker and G. Huisken, "Mean curvature evolution of entire graphs," Annals of . Mathematics 130, pp. 453-471, 1989. [20] K. Ecker...1987. [28] M. Grayson, "Shortening embedded curves," Annals of Mathematics 129, pp. 71-111, 1989. 22 [29] M. Grayson, "A short note on the evolution of

  14. Surface critical behavior of the smoothly inhomogeneous Ising model

    Science.gov (United States)

    Burkhardt, Theodore W.; Guim, Ihnsouk

    1984-01-01

    We consider a semi-infinite two-dimensional Ising model with nearest-neighbor coupling constants that deviate from the bulk coupling by Am-y for large m, m being the distance from the edge. The case ALeeuwen. We report exact results for the boundary magnetization and boundary pair-correlation function when A>0. At the bulk critical temperature there is a rich variety of critical behavior in the A -y plane with both paramagnetic and ferromagnetic surface phases. Some of our results can be derived and generalized with simple scaling arguments.

  15. Comparison of waxy and normal potato starch remaining granules after chemical surface gelatinization: Pasting behavior and surface morphology

    NARCIS (Netherlands)

    Huang, J.; Chen Zenghong,; Xu, Yalun; Li, Hongliang; Liu, Shuxing; Yang, Daqing; Schols, H.A.

    2014-01-01

    o understand the contribution of granule inner portion to the pasting property of starch, waxy potato starch and two normal potato starches and their acetylated starch samples were subjected to chemical surface gelatinization by 3.8 mol/L CaCl2 to obtain remaining granules. Native and acetylated, or

  16. Comparison of waxy and normal potato starch remaining granules after chemical surface gelatinization: Pasting behavior and surface morphology

    NARCIS (Netherlands)

    Huang, J.; Chen Zenghong,; Xu, Yalun; Li, Hongliang; Liu, Shuxing; Yang, Daqing; Schols, H.A.

    2014-01-01

    o understand the contribution of granule inner portion to the pasting property of starch, waxy potato starch and two normal potato starches and their acetylated starch samples were subjected to chemical surface gelatinization by 3.8 mol/L CaCl2 to obtain remaining granules. Native and acetylated,

  17. Smooth surface micro finite element modelling of a cancellous bone analogue material.

    Science.gov (United States)

    Leung, S Y; Browne, M; New, A M

    2008-01-01

    Tetrahedral finite element meshes with smooth surfaces can be created from computed tomography scans of cancellous bone in order to evaluate its mechanical properties. Image processing before creation of the mesh can affect the accuracy of determined mechanical properties. For a cancellous bone analogue, threshold, mesh density and surface smoothing parameters used in mesh generation were varied and the mechanical properties predicted by the resulting meshes were compared to experimental results. This study has shown that threshold selection is vital for accurate determination of volume fraction and resulting mechanical properties.

  18. Locally controlled globally smooth ground surface reconstruction from terrestrial point clouds

    CERN Document Server

    Rychkov, Igor

    2012-01-01

    Approaches to ground surface reconstruction from massive terrestrial point clouds are presented. Using a set of local least squares (LSQR) planes, the "holes" are filled either from the ground model of the next coarser level or by Hermite Radial Basis Functions (HRBF). Global curvature continuous as well as infinitely smooth ground surface models are obtained with Partition of Unity (PU) using either tensor product B-Splines or compactly supported exponential function. The resulting surface function has local control enabling fast evaluation.

  19. Comparison of waxy and normal potato starch remaining granules after chemical surface gelatinization: pasting behavior and surface morphology.

    Science.gov (United States)

    Huang, Junrong; Chen, Zhenghong; Xu, Yalun; Li, Hongliang; Liu, Shuxing; Yang, Daqing; Schols, Henk A

    2014-02-15

    To understand the contribution of granule inner portion to the pasting property of starch, waxy potato starch and two normal potato starches and their acetylated starch samples were subjected to chemical surface gelatinization by 3.8 mol/L CaCl2 to obtain remaining granules. Native and acetylated, original and remaining granules of waxy potato starch had similar rapid visco analyzer (RVA) pasting profiles, while those of two normal potato starches behaved obviously different from each other. All remaining granules had lower peak viscosity than the corresponding original granules. Contribution of waxy potato starch granule's inner portion to the peak viscosity was significant more than those of normal potato starches. The shell structure appearing on the remaining granule surface for waxy potato starch was smoother and thinner than that for normal potato starches as observed by scanning electron microscopy, indicating a more regular structure of shell and a more ordered packing of shell for waxy potato starch granules. The blocklet size of waxy potato starch was smaller and more uniform than those of normal potato starches as shown by atomic force microscopy images of original and remaining granules. In general, our results provided the evidence for the spatial structure diversity between waxy and normal potato starch granules: outer layer and inner portion of waxy potato starch granule had similar structure, while outer layer had notably different structure from inner portion for normal potato starch granule.

  20. Wetting property of smooth and textured hydrophobic surfaces under condensation condition

    Science.gov (United States)

    Hao, PengFei; Lv, CunJing; Yao, ZhaoHui; Niu, FengLei

    2014-11-01

    Static and dynamic wetting behaviors of sessile droplet on smooth, microstructured and micro/nanostructured surface under condensation condition are systematically studied. In contrast to the conventional droplet wetting on such natural materials by dropping, we demonstrate here that when dropwise condensation occurs, the sessile droplet will transit from the Cassie-Baxter wetting state to the Wenzel wetting state or partial Cassie-Baxter wetting state on the microstructured surface or the micro/nanostructured surface, which leads to a strong adhesion between the droplet and the substrate. In contrast, the apparent contact angle and the sliding angle on the smooth surface changes a little before and after the condensation because of small roughness. Theoretical analysis shows that the roughness factor controls the adhesion force of the droplet during condensation, and a theoretical model is constructed which will be helpful for us to understand the relationship between the adhesion force and the geometry of the surface.

  1. Three-Dimensional Smoothed Particle Hydrodynamics Simulation for Liquid Droplet with Surface Tension

    CERN Document Server

    Terissa, Hanifa; Naa, Christian Fredy

    2013-01-01

    We provide a basic method of Smoothed Particle Hydrodynamics (SPH) to simulate liquid droplet with surface tension in three dimensions. Liquid droplet is a simple case for surface tension modeling. Surface tension works only on fluid surface. In SPH method, we simply apply the surface tension on the boundary particles of liquid. The particle on the 3D boundary was detected dynamically using Free-Surface Detection algorithm. The normal vector and curvature of the boundary surface were calculated simultaneously with 3D boundary surface reconstruction using Moving Least-Squares (MLS) method. Before the reconstruction, the coordinate system was transformed into a local coordinate system. Afterwards, the surface tension force which depends on curvature of the surface, was calculated and applied on the boundary particles of the droplet. We present the simulation result of droplet motion with gravity force. By using the basic method of SPH for fluid modeling, and a combination of 3D Free-Surface Detection algorithm ...

  2. A Fast Variational Method for the Construction of Resolution Adaptive C-Smooth Molecular Surfaces.

    Science.gov (United States)

    Bajaj, Chandrajit L; Xu, Guoliang; Zhang, Qin

    2009-05-01

    We present a variational approach to smooth molecular (proteins, nucleic acids) surface constructions, starting from atomic coordinates, as available from the protein and nucleic-acid data banks. Molecular dynamics (MD) simulations traditionally used in understanding protein and nucleic-acid folding processes, are based on molecular force fields, and require smooth models of these molecular surfaces. To accelerate MD simulations, a popular methodology is to employ coarse grained molecular models, which represent clusters of atoms with similar physical properties by psuedo- atoms, resulting in coarser resolution molecular surfaces. We consider generation of these mixed-resolution or adaptive molecular surfaces. Our approach starts from deriving a general form second order geometric partial differential equation in the level-set formulation, by minimizing a first order energy functional which additionally includes a regularization term to minimize the occurrence of chemically infeasible molecular surface pockets or tunnel-like artifacts. To achieve even higher computational efficiency, a fast cubic B-spline C(2) interpolation algorithm is also utilized. A narrow band, tri-cubic B-spline level-set method is then used to provide C(2) smooth and resolution adaptive molecular surfaces.

  3. In-vitro characteristics of cemented titanium femoral stems with a smooth surface finish.

    Science.gov (United States)

    Akiyama, Haruhiko; Yamamoto, Koji; Kaneuji, Ayumi; Matsumoto, Tadami; Nakamura, Takashi

    2013-01-01

    In cemented total hip arthroplasty (THA), a polished tapered femoral stem with a design based on the taper-slip concept enables extremely reliable and durable fixation. In contrast, cemented femoral stems made from titanium alloys are not favored because of reports describing insufficient clinical outcomes. However, we have reported excellent clinical and radiological outcomes for cemented titanium stems made using the composite-beam concept. This study examines the characteristics of cemented titanium femoral stems with a smooth surface. The bonding strength between titanium alloys with different surface finishes and bone cement was evaluated by use of push-out and detachment tests. Torsional stability tests were performed to evaluate the initiation and propagation of disruption of the fixation of cemented stems at the cement-implant interface. The wear resistance was investigated by use of wear-friction tests performed using a multidirectional pin-on-disc machine. The bone strain loaded on to the femoral cortex was measured by use of an implanted Sawbone and analyzed by use of the finite element method. The push-out and detachment tests revealed increasing cement adhesion strength with increasing degree of roughness of the metal surface. The torsional stability tests indicated that a load >1,000 N led to progressive debonding between the cement and the implant with a smooth surface finish. Interestingly, wear-friction tests revealed the wear rate for polished titanium surfaces was clearly higher than for smooth surfaces. In addition, the greater elasticity of titanium stems compared with cobalt-chromium stems transmitted the external load to the proximal side of the femur more effectively. The smooth surface finish of the stems is an important factor for the satisfactory clinical and radiological outcomes of cemented titanium femoral stems. The greater elasticity of a titanium stem effectively transmits the external load to the medial side of the femur.

  4. 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.

  5. Comparison of QLF and DIAGNOdent for quantification of smooth surface caries.

    Science.gov (United States)

    Shi, X Q; Tranaeus, S; Angmar-Månsson, B

    2001-01-01

    The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light-induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non-cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five-point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman's rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D(3) level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut-off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut-off value of 20% of fluorescence loss. Spearman's rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

  6. Contact angle and droplet heat transfer during evaporation on structured and smooth surfaces of heated wall

    Science.gov (United States)

    Misyura, S. Y.

    2017-08-01

    Water evaporation in a wide range of droplet diameters and wall temperatures on the structured and smooth surfaces were studied experimentally. Linear dependence of evaporation rate (dV/dt) on a droplet radius varies when the volume is greater than 40-60 μl. The static contact angles on the structured surface vary with a droplet diameter for high wall superheating. Dependence of the contact angle on diameter for the corrugated surface is defined by a change in both potential energy barrier U and three-phase contact line tension τcl. This energy barrier for the structured wall changes with an increase in the initial droplet diameter and becomes constant for the large droplets. For high wall superheating, the power in the law of evaporation increases from 1 to 1.45 with an increase in the initial droplet diameter. Depending on the droplet radius, number of droplets and heater length, four different characters of evaporation are realized. Complete droplet evaporation time on structured surface is less than smooth wall. Heat transfer coefficient is greater for structured wall than smooth one. When simulating droplet evaporation and heat transfer, it is necessary to take into account free convection of air and vapor.

  7. MC3T3-E1 Cells on Titanium Surfaces with Nanometer Smoothness and Fibronectin Immobilization

    Directory of Open Access Journals (Sweden)

    Tohru Hayakawa

    2012-01-01

    Full Text Available The present study was aimed to evaluate the viability and total protein contents of osteoblast-like cells on the titanium surface with different surface mechanical treatment, namely, nanometer smoothing (Ra: approximately 2.0 nm and sandblasting (Ra: approximately 1.0 μm, and biochemical treatment, namely, with or without fibronectin immobilization. Fibronectin could be easily immobilized by tresyl chloride-activation technique. MC3T3-E1 cells were seeded on the different titanium surfaces. Cell viability was determined by MTT assay. At 1 day of cell culture, there were no significant differences in cell viability among four different titanium surfaces. At 11 days, sandblasted titanium surface with fibronectin immobilization showed the significantly highest cell viability than other titanium surface. No significant differences existed for total protein contents among four different titanium surfaces at 11 days of cell culture. Scanning electron microscopy observation revealed that smoothness of titanium surface produced more spread cell morphologies, but that fibronectin immobilization did not cause any changes of the morphologies of attached cells. Fibronectin immobilization provided greater amount of the number of attached cells and better arrangement of attached cells. In conclusion, the combination of sandblasting and fibronectin immobilization enhanced the cell viability and fibronectin immobilization providing better arrangements of attached cells.

  8. Local Adaptive Calibration of the GLASS Surface Incident Shortwave Radiation Product Using Smoothing Spline

    Science.gov (United States)

    Zhang, X.; Liang, S.; Wang, G.

    2015-12-01

    Incident solar radiation (ISR) over the Earth's surface plays an important role in determining the Earth's climate and environment. Generally, can be obtained from direct measurements, remotely sensed data, or reanalysis and general circulation models (GCMs) data. Each type of product has advantages and limitations: the surface direct measurements provide accurate but sparse spatial coverage, whereas other global products may have large uncertainties. Ground measurements have been normally used for validation and occasionally calibration, but transforming their "true values" spatially to improve the satellite products is still a new and challenging topic. In this study, an improved thin-plate smoothing spline approach is presented to locally "calibrate" the Global LAnd Surface Satellite (GLASS) ISR product using the reconstructed ISR data from surface meteorological measurements. The influences of surface elevation on ISR estimation was also considered in the proposed method. The point-based surface reconstructed ISR was used as the response variable, and the GLASS ISR product and the surface elevation data at the corresponding locations as explanatory variables to train the thin plate spline model. We evaluated the performance of the approach using the cross-validation method at both daily and monthly time scales over China. We also evaluated estimated ISR based on the thin-plate spline method using independent ground measurements at 10 sites from the Coordinated Enhanced Observation Network (CEON). These validation results indicated that the thin plate smoothing spline method can be effectively used for calibrating satellite derived ISR products using ground measurements to achieve better accuracy.

  9. Surface topography of cylindrical gear wheels after smoothing in abrasive mass, honing and shot peening

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, J; Pawlus, P [Rzeszow University of Technology, W Pola 2, 35-935 Rzeszow (Poland); Zelasko, W, E-mail: jmichals@prz.edu.pl [Technical School Complex at Lezajsk, Mickiewicza 67, 37-300 Lezajsk (Poland)

    2011-08-19

    The present paper presents the analysis of surface topography of gear teeth as the result of final machining processes. Teeth of multiple cylindrical gears shaped by grinding were smoothed in abrasive mass, honed or shot peened. The measurement of gears were made using coordinate measuring machine and 3D surface topography stylus instrument. The following deviations were studied; pitch deviation, total pitches deviations, variation of teeth thickness and deviation of gear radial run-out. Changes in teeth surface topography during machining process were determined. 3D surface topography parameters, surface directionality as well as areal autocorrelation and power spectral density functions were taken into consideration. As the results of the analysis, the best surface topography with regard to gear operational properties was recommended.

  10. Surface topography of cylindrical gear wheels after smoothing in abrasive mass, honing and shot peening

    Science.gov (United States)

    Michalski, J.; Pawlus, P.; Żelasko, W.

    2011-08-01

    The present paper presents the analysis of surface topography of gear teeth as the result of final machining processes. Teeth of multiple cylindrical gears shaped by grinding were smoothed in abrasive mass, honed or shot peened. The measurement of gears were made using coordinate measuring machine and 3D surface topography stylus instrument. The following deviations were studied; pitch deviation, total pitches deviations, variation of teeth thickness and deviation of gear radial run-out. Changes in teeth surface topography during machining process were determined. 3D surface topography parameters, surface directionality as well as areal autocorrelation and power spectral density functions were taken into consideration. As the results of the analysis, the best surface topography with regard to gear operational properties was recommended.

  11. Structures and ultrafast dynamics of interfacial water assemblies on smooth hydrophobic surfaces

    Science.gov (United States)

    Yang, Ding-Shyue; He, Xing

    2017-09-01

    Using time-averaged and ultrafast electron diffraction, structures and ultrafast dynamics of interfacial water assemblies on smooth hydrophobic surfaces are reported. The lack of hydrophilic interaction and topographical template effect from the support surface leads to the formation of small, mostly randomly-oriented, ice crystallites with the cubic structure. Dynamically, following the substrate photoexcitation, interfacial water assemblies undergo four stages of changes-ultrafast melting, nonequilibrium isotropic phase transformation, annealing, and restructuring-which are closely correlated with the substrate dynamics. The connectivity and cooperative nature of the hydrogen-bonded network is considered crucial for water assemblies to withstand large structural motions without sublimation on ultrashort times.

  12. Effects of bionic non-smooth surface on reducing soil resistance to disc ploughing

    Institute of Scientific and Technical Information of China (English)

    CHIRENDE; Benard; SIMALENGA; Timothy; Emmanuel

    2010-01-01

    Past researches have shown that the non-smooth body surfaces of soil burrowing animals help to reduce soil resistance. In this research, this concept of bionic non-smooth surface was applied to disc ploughs and an experiment was conducted in an indoor soil bin to find out the effects of different bionic units on reducing soil resistance to disc ploughing. Horizontal force acting on the disc plough during soil deformation was measured using a 5 kN sensor. Convex and concave bionic units were used and the material used for making convex ones is ultra high molecular weight polyethylene (UHMWPE) which is hydrophobic. From the experiment results, higher or deeper bionic units always resulted in less soil resistance. Convex bionic units gave the highest resistance reduction reaching a maximum of 19% reduction (from 1715.36 N to 1383.65 N) compared to concave bi-onic units. Also, samples with a bionic unit density of 30% gave the highest resistance reduction compared to the other two, which were either plain or had 10% density. In conclusion, the concept of bionic non-smooth units can be applied to disc ploughs in order to reduce soil resistance.

  13. Smoothing Algorithm for Planar and Surface Mesh Based on Element Geometric Deformation

    Directory of Open Access Journals (Sweden)

    Shuli Sun

    2015-01-01

    Full Text Available Smoothing is one of the basic procedures for improvement of mesh quality. In this paper, a novel and efficient smoothing approach for planar and surface mesh based on element geometric deformation is developed. The presented approach involves two main stages. The first stage is geometric deformation of all the individual elements through a specially designed two-step stretching-shrinking operation (SSO, which is performed by moving the vertices of each element according to a certain rule in order to get better shape of the element. The second stage is to determine the position of each node of the mesh by a weighted average strategy according to quality changes of its adjacent elements. The suggested SSO-based smoothing algorithm works efficiently for triangular mesh and can be naturally expanded to quadrilateral mesh, arbitrary polygonal mesh, and mixed mesh. Combined with quadratic error metric (QEM, this approach may be also applied to improve the quality of surface mesh. The proposed method is simple to program and inherently very suitable for parallelization, especially on graphic processing unit (GPU. Results of numerical experiments demonstrate the effectiveness and potential of this method.

  14. A two-step process for controlling the surface smoothness of polyelectrolyte-based microcapsules.

    Science.gov (United States)

    Lacík, I; Anilkumar, A V; Wang, T G

    2001-01-01

    Biocompatibility is one of the crucial requirements to be fulfilled when designing devices for immunoisolation of transplanted cells. The quality of the capsule surface (smoothness/roughness) influences the nature of cell overgrowth on it by immunocytes, which eventually may lead to the transplant failure. A microcapsule has been developed based on the polyelectrolyte complexation of the polyanions sodium alginate and cellulose sulphate with the polycation poly(methylene-co-guanidine), which was successfully tested in rodent animal models. Recently, the principles for controlling the surface smoothness of these capsules has been identified. This paper reports on a two-step process used for production of stable capsules with improved surface properties. The methodology involves separating the process of drop shape recovery and precursor capsule formation from the process of membrane formation by applying a two-reactor design. The multi-loop reactors are connected in series, and the process separation is given by the different composition of cation solutions flowing in each reactor. This process enables one to prepare the microcapsule immunoisolation device, which can differ in the extent of surface roughness and, thus, is suitable for studying the effect of surface morphology of the immunoisolation device on cell overgrowth. The effect of this process on the capsule permeability has also been evaluated.

  15. Wetting property of smooth and textured hydrophobic surfaces under condensation condition

    Institute of Scientific and Technical Information of China (English)

    HAO PengFei; LV CunJing; YAO ZhaoHui; NIU FengLei

    2014-01-01

    Static and dynamic wetting behaviors of sessile droplet on smooth,microstructured and micro/nanostructured surface under condensation condition are systematically studied.In contrast to the conventional droplet wetting on such natural materials by dropping,we demonstrate here that when dropwise condensation occurs,the sessile droplet will transit from the Cassie-Baxter wetting state to the Wenzel wetting state or partial Cassie-Baxter wetting state on the microstructured surface or the micro/nanostructured surface,which leads to a strong adhesion between the droplet and the substrate.In contrast,the apparent contact angle and the sliding angle on the smooth surface changes a little before and after the condensation because of small roughness.Theoretical analysis shows that the roughness factor controls the adhesion force of the droplet during condensation,and a theoretical model is constructed which will be helpful for us to understand the relationship between the adhesion force and the geometry of the surface.

  16. Kelvin Helmholtz instability in an ultrathin air film causes drop splashing on smooth surfaces

    CERN Document Server

    Liu, Yuan; Xu, Lei

    2015-01-01

    When a fast-moving drop impacts onto a smooth substrate, splashing will be produced at the edge of the expanding liquid sheet. This ubiquitous phenomenon lacks a fundamental understanding. Combining experiment with model, we illustrate that the ultrathin air film trapped under the expanding liquid front triggers splashing. Because this film is thinner than the mean free path of air molecules, the interior airflow transfers momentum with an unusually high velocity comparable to the speed of sound and generates a stress 10 times stronger than the airflow in common situations. Such a large stress initiates Kelvin Helmholtz instabilities at small length scales and effectively produces splashing. Our model agrees quantitatively with experimental verifications and brings a fundamental understanding to the ubiquitous phenomenon of drop splashing on smooth surfaces.

  17. Pairwise Force Smoothed Particle Hydrodynamics model for multiphase flow: Surface tension and contact line dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Tartakovsky, Alexandre M.; Panchenko, Alexander

    2016-01-01

    We present a novel formulation of the Pairwise Force Smoothed Particle Hydrodynamics Model (PF-SPH) and use it to simulate two- and three-phase flows in bounded domains. In the PF-SPH model, the Navier-Stokes equations are discretized with the Smoothed Particle Hydrodynamics (SPH) method and the Young-Laplace boundary condition at the fluid-fluid interface and the Young boundary condition at the fluid-fluid-solid interface are replaced with pairwise forces added into the Navier-Stokes equations. We derive a relationship between the parameters in the pairwise forces and the surface tension and static contact angle. Next, we demonstrate the accuracy of the model under static and dynamic conditions. Finally, to demonstrate the capabilities and robustness of the model we use it to simulate flow of three fluids in a porous material.

  18. Pairwise Force Smoothed Particle Hydrodynamics model for multiphase flow: Surface tension and contact line dynamics

    Science.gov (United States)

    Tartakovsky, Alexandre M.; Panchenko, Alexander

    2016-01-01

    We present a novel formulation of the Pairwise Force Smoothed Particle Hydrodynamics (PF-SPH) model and use it to simulate two- and three-phase flows in bounded domains. In the PF-SPH model, the Navier-Stokes equations are discretized with the Smoothed Particle Hydrodynamics (SPH) method, and the Young-Laplace boundary condition at the fluid-fluid interface and the Young boundary condition at the fluid-fluid-solid interface are replaced with pairwise forces added into the Navier-Stokes equations. We derive a relationship between the parameters in the pairwise forces and the surface tension and static contact angle. Next, we demonstrate the model's accuracy under static and dynamic conditions. Finally, we use the Pf-SPH model to simulate three phase flow in a porous medium.

  19. Kelvin-Helmholtz instability in an ultrathin air film causes drop splashing on smooth surfaces.

    Science.gov (United States)

    Liu, Yuan; Tan, Peng; Xu, Lei

    2015-03-17

    When a fast-moving drop impacts onto a smooth substrate, splashing will be produced at the edge of the expanding liquid sheet. This ubiquitous phenomenon lacks a fundamental understanding. Combining experiment with model, we illustrate that the ultrathin air film trapped under the expanding liquid front triggers splashing. Because this film is thinner than the mean free path of air molecules, the interior airflow transfers momentum with an unusually high velocity comparable to the speed of sound and generates a stress 10 times stronger than the airflow in common situations. Such a large stress initiates Kelvin-Helmholtz instabilities at small length scales and effectively produces splashing. Our model agrees quantitatively with experimental verifications and brings a fundamental understanding to the ubiquitous phenomenon of drop splashing on smooth surfaces.

  20. Left ventricle endocardium segmentation for cardiac CT volumes using an optimal smooth surface

    Science.gov (United States)

    Zheng, Yefeng; Georgescu, Bogdan; Vega-Higuera, Fernando; Comaniciu, Dorin

    2009-02-01

    We recently proposed a robust heart chamber segmentation approach based on marginal space learning. In this paper, we focus on improving the LV endocardium segmentation accuracy by searching for an optimal smooth mesh that tightly encloses the whole blood pool. The refinement procedure is formulated as an optimization problem: maximizing the surface smoothness under the tightness constraint. The formulation is a convex quadratic programming problem, therefore has a unique global optimum and can be solved efficiently. Our approach has been validated on the largest cardiac CT dataset (457 volumes from 186 patients) ever reported. Compared to our previous work, it reduces the mean point-to-mesh error from 1.13 mm to 0.84 mm (22% improvement). Additionally, the system has been extensively tested on a dataset with 2000+ volumes without any major failure.

  1. Laboratory evaluation of toothbrush/toothpaste abrasion resistance after smooth enamel surface sealing.

    Science.gov (United States)

    Korbmacher-Steiner, Heike M; Schilling, Arndt F; Huck, Lothar G; Kahl-Nieke, Bärbel; Amling, Michael

    2013-04-01

    The use of dental sealants has been extended to smooth enamel surfaces. The present study was conducted to test the in vitro performance of four sealants with different characteristics (highly and lowly filled, self-etching features). Eighty human teeth (lower incisors and premolars) were randomly divided into following sealant test groups: ProSeal(TM), LightBond(TM), OrthoSolo(TM), and Seal&Protect(®). Twenty untreated teeth served as a control group. Tooth brushing was conducted for a period of time simulating 12, 18, and 24 months. During the toothbrush abrasion protocol, the specimens were subjected to thermal and acidic challenge. Sealant thickness was determined with μCT imaging, and qualitative and quantitative surface effects were investigated using stereo microscopy and raster electron microscopy, respectively. Data were subjected to t test or Kruskal-Wallis/Mann-Whitney tests (alpha, 5%). The wear behavior and film integrity of highly filled sealants were superior to lowly filled sealants. Even after 1 year of tooth brushing, significant surface deterioration with deleterious loss of enamel and discoloration was observed in all tested materials (χ(2) = 15.349; P = 0.004). The size of the observed defects increased over time. These results suggest that the application of sealants on smooth enamel surfaces should be limited to special indications, and their usefulness has to be revisited. Based on the results of this in vitro study, the general overall application of enamel sealants needs to be questioned.

  2. Genetic Susceptibility to Dental Caries on Pit and Fissure and Smooth Surfaces

    Science.gov (United States)

    Shaffer, J.R.; Wang, X.; DeSensi, R.S.; Wendell, S.; Weyant, R.J.; Cuenco, K.T.; Crout, R.; McNeil, D.W.; Marazita, M.L.

    2012-01-01

    Carious lesions are distributed nonuniformly across tooth surfaces of the complete dentition, suggesting that the effects of risk factors may be surface-specific. Whether genes differentially affect caries risk across tooth surfaces is unknown. We investigated the role of genetics on two classes of tooth surfaces, pit and fissure surfaces (PFS) and smooth surfaces (SMS), in more than 2,600 subjects from 740 families. Participants were examined for surface-level evidence of dental caries, and caries scores for permanent and/or primary teeth were generated separately for PFS and SMS. Heritability estimates (h2, i.e. the proportion of trait variation due to genes) of PFS and SMS caries scores were obtained using likelihood methods. The genetic correlations between PFS and SMS caries scores were calculated to assess the degree to which traits covary due to common genetic effects. Overall, the heritability of caries scores was similar for PFS (h2 = 19–53%; p caries scores for both PFS and SMS in the primary dentition was greater than in the permanent dentition and total dentition. With one exception, the genetic correlation between PFS and SMS caries scores was not significantly different from 100%, indicating that (mostly) common genes are involved in the risk of caries for both surface types. Genetic correlation for the primary dentition dfs (decay + filled surfaces) was significantly less than 100% (p caries risk in PFS versus SMS in the primary dentition. PMID:22286298

  3. Osteogenic potential of bone marrow stromal cells on smooth, roughened, and tricalcium phosphate-modified titanium alloy surfaces.

    LENUS (Irish Health Repository)

    Colombo, John S

    2012-09-01

    This study investigated the influence of smooth, roughened, and tricalcium phosphate (TCP)-coated roughened titanium-aluminum-vanadium (Ti-6Al-4V) surfaces on the osteogenic potential of rat bone marrow stromal cells (BMSCs).

  4. 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.

  5. Surface Wave Tomography with Spatially Varying Smoothing Based on Continuous Model Regionalization

    Science.gov (United States)

    Liu, Chuanming; Yao, Huajian

    2017-03-01

    Surface wave tomography based on continuous regionalization of model parameters is widely used to invert for 2-D phase or group velocity maps. An inevitable problem is that the distribution of ray paths is far from homogeneous due to the spatially uneven distribution of stations and seismic events, which often affects the spatial resolution of the tomographic model. We present an improved tomographic method with a spatially varying smoothing scheme that is based on the continuous regionalization approach. The smoothness of the inverted model is constrained by the Gaussian a priori model covariance function with spatially varying correlation lengths based on ray path density. In addition, a two-step inversion procedure is used to suppress the effects of data outliers on tomographic models. Both synthetic and real data are used to evaluate this newly developed tomographic algorithm. In the synthetic tests, when the contrived model has different scales of anomalies but with uneven ray path distribution, we compare the performance of our spatially varying smoothing method with the traditional inversion method, and show that the new method is capable of improving the recovery in regions of dense ray sampling. For real data applications, the resulting phase velocity maps of Rayleigh waves in SE Tibet produced using the spatially varying smoothing method show similar features to the results with the traditional method. However, the new results contain more detailed structures and appears to better resolve the amplitude of anomalies. From both synthetic and real data tests we demonstrate that our new approach is useful to achieve spatially varying resolution when used in regions with heterogeneous ray path distribution.

  6. Discussion on a mechanical equilibrium condition of a sessile drop on a smooth solid surface.

    Science.gov (United States)

    Yonemoto, Yukihiro; Kunugi, Tomoaki

    2009-04-14

    Young's equation describes an interfacial equilibrium condition of a liquid droplet on a smooth solid surface. This relation is derived by Thomas Young in 1805. It has been discussed until today after his work. In general, Young's equation is discussed from the viewpoint of thermodynamics and derived by minimizing the total free energy of the system with intensive parameters in the total free energy kept constant, i.e., the variation in the total free energy is zero. In the derivation, the virtual work variations in the horizontal and vertical directions of the droplet on the smooth solid are considered independently. However, the virtual work variation at the droplet surface depends on the variation of the horizontal and vertical directions, which are related to an incline of the droplet surface. This point has been overlooked in past studies. In this study, by considering this directional dependency, we derive the modified Young's equation based on the thermodynamics. Finally, we evaluate the modified Young's equation by comparing the analytical solution of the relationship between a contact angle and the contact line radii of the droplet with some experimental data. Moreover, we investigated the line tension itself.

  7. Validation of DIAGNOdent for quantification of smooth-surface caries: an in vitro study.

    Science.gov (United States)

    Shi, X Q; Tranaeus, S; Angmar-Månsson, B

    2001-04-01

    The aims were 1) to validate a laser-based device, KaVo DIAGNOdent, for quantification of caries lesions on smooth surfaces, using histopathologic and microradiographic analyses as the gold standard, and 2) to test inter- and intra-observer agreements. We also investigated the influence on DIAGNOdent readings of the storage medium used for extracted teeth. Two observers measured independently the tooth surfaces of 40 extracted premolars that had been stored in thymol-saturated saline. After subsequent storage in neutral-buffered formalin for 14 days they were re-measured. The teeth were then sectioned for histopathologic and microradiographic analysis. The Spearman rank correlation coefficients between lesion depth and DIAGNOdent readings were 0.78-0.83 and 0.85 for teeth stored in thymol-saturated saline and formalin, respectively. Inter- and intra-observer agreements were 0.94 and 0.95 when the teeth were stored in thymol-saturated saline. The DIAGNOdent reading was almost 1.5 times higher for teeth stored in formalin than for those stored in thymol saline. The Spearman rank correlation coefficient between mineral loss in enamel (deltaZ) and DIAGNOdent readings ranged from 0.64 to 0.68. It was concluded that DIAGNOdent may be helpful for assessing smooth-surface caries, but the cut-off points need to be assessed under clinical conditions. The increase in fluorescence associated with storage of teeth in formalin warrants further investigation.

  8. Optimization of atomically smooth and metallic surface of SrTiO3

    Science.gov (United States)

    Kwak, In Hae; Varnoosfaderani, Sima saeidi; Barquist, Colin S.; Paykar, Ashkan; Shakya, Ambika; Lee, Yoonseok; Hebard, Arthur F.; Biswas, Amlan

    2017-04-01

    We obtained metallic SrTiO3 with an atomically smooth surface, where the step height is close to the unit cell height of the crystal. After the surface treatments for generating the TiO2 terminated layer, the optimal conditions for vacuum annealing were found. The atomically smooth surface was verified by atomic force microscopy and lateral force microscopy. The temperature dependent resistance R(T) measured down to 52 mK indicates the metallic behavior, and its physical origin of the conduction was analyzed by fitting an equation involving electron-phonon and electron-electron scattering mechanisms. Our results are similar to R(T) reported for LaAlO3/SrTiO3 interfaces. In addition, the Hall effect measurement shows a clear resemblance between our reduced SrTiO3 and LaAlO3/SrTiO3 interfaces with sheet carrier density and Hall mobility. We expect that our treatments not only promote the usage of conducting SrTiO3 substrates for subsequent thin film growth but also contribute to the current research interest in two dimensional electron gas (2DEG) SrTiO3 and the interfaces between insulating oxides of LaAlO3/SrTiO3.

  9. The Mechanism of Drag Reduction around Bodies of Revolution Using Bionic Non-Smooth Surfaces

    Institute of Scientific and Technical Information of China (English)

    Li-mei Tian; Lu-quan Ren; Qing-ping Liu; Zhi-wu Han; Xiao Jiang

    2007-01-01

    Bionic non-smooth surfaces (BNSS) can reduce drag. Much attention has been paid to the mechanism of shear stress reduction by riblets. The mechanism of pressure force reduction by bionic non-smooth surfaces on bodies of revolution has not been, well investigated. In this work CFD simulation has revealed the mechanism of drag reduction by BNSS, which may work in three ways. First, BNSS on bodies of revolution may lower the surface velocity of the medium, which prevents the sudden speed up of air on the cross section. So the bottom pressure of the model would not be disturbed sharply, resulting in less energy loss and drag reduction. Second, the magnitude of vorticity induced by the bionic model becomes smaller because, due to the sculpturing, the growth of tiny air bubbles is avoided. Thus the large moment of inertia induced by large air bubble is reduced. The reduction of the vorticity could reduce the dissipation of the eddy. So the pressure force could also be reduced. Third, the thickness of the momentum layer on the model becomes less which, according to the relationship between the drag coefficient and the momentum thickness, reduces drag.

  10. Realization of effective light trapping and omnidirectional antireflection in smooth surface silicon nanowire arrays.

    Science.gov (United States)

    Xie, W Q; Oh, J I; Shen, W Z

    2011-02-11

    We have successfully fabricated well-ordered silicon nanowire (SiNW) arrays of smooth surface by using a low-cost and facile Ag-assisted chemical etching technique. We have experimentally found that the reflectance can be significantly suppressed (absorption in SiNW arrays, we have obtained a photocurrent enhancement of up to 425% per unit volume of material as compared to crystalline Si, implying that effective light trapping can be realized in the as-grown samples. In addition, we have demonstrated experimentally and theoretically that the as-grown samples have an omnidirectional high-efficiency antireflection property.

  11. Electronic structure for a topological insulator with a smoothly varying step on surface

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ma; Liu, Yiman; Shao, Huaihua; Zhou, Xiaoying; Zhou, Guanghui, E-mail: ghzhou@hunnu.edu.cn

    2014-12-01

    We study the penetration depth (PD) of surface state into the bulk, the local density of states (LDOS) and the spin-polarized STM tip tunneling conductance (TG) for a smoothly varying step described by an asymptotic model, on the surface of a three-dimensional (3D) topological insulator (TI). Using curvilinear coordinates for calculation, we find that the PD shows two peaks near step edges with maximum surface curvature and a dip value of flat surface at step middle with zero curvature. In contrast, the LDOS exhibits a double valley (dip) pattern, in which it rapidly declines from the highest value for flat surface to the dip value near step edges, and then shows a small peak at step middle. This interesting small peak is in good agreement with experimentally observed LDOS peak within a step of definite span on a 3D TI surface. Moreover, the calculated surface spin-polarized STM tip TG also confirms the LDOS qualitatively. The findings here may provide a further understanding of 3D TI surface with step line defects.

  12. Noncontact monitoring of surface-wave nonlinearity for predicting the remaining life of fatigued steels

    Science.gov (United States)

    Ogi, Hirotsugu; Hirao, Masahiko; Aoki, Shinji

    2001-07-01

    A nonlinear acoustic measurement is studied for fatigue damage monitoring. An electromagnetic acoustic transducer (EMAT) magnetostrictively couples to a surface-shear-wave resonance along the circumference of a rod specimen during rotating bending fatigue of carbon steels. Excitation of the EMAT at half of the resonance frequency caused the standing wave to contain only the second-harmonic component, which was received by the same EMAT to determine the second-harmonic amplitude. Thus measured surface-wave nonlinearity always showed two distinct peaks at 60% and 85% of the total life. We attribute the earlier peak to crack nucleation and growth, and the later peak to an increase of free dislocations associated with crack extension in the final stage. This noncontact resonance-EMAT measurement can monitor the evolution of the surface-shear-wave nonlinearity throughout the metal's fatigue life and detect the pertinent precursors of the eventual failure.

  13. Brief communication: a pilot study: smooth surface early caries (caries incipiens) detection with KaVo DIAGNODent in historical material.

    Science.gov (United States)

    Tomczyk, Jacek; Komarnitki, Iulian; Olczak-Kowalczyk, Dorota

    2013-03-01

    In many odontological studies concerning archeological material, there is no analysis of early caries lesions (caries incipiens) that manifest as a carious spot. At this stage of caries, the enamel is still hard, and thus, it is impossible to diagnose caries by visual methods. We assessed the usefulness of the DIAGNODent pen (DD laser) in analyzing noncavity lesions on the smooth surface sites of crowns from historical populations. Twenty-seven individuals were examined: 18 from Radom (Poland), and nine from Tell Masaikh and Terqa (Syria). A total of 562 teeth were characterized. The series represented different climatic zones, but were dated from the similar period, 18th to 19th century AD. We used four diagnostic techniques: visual, DD laser, radiographic, and histological as the gold standard. DD laser showed that the mean values of healthy enamel in both series did not exceed 15 units. The mean values of smooth and rough spots in the Syrian population were significantly higher than those from Poland. This study showed that all the noncarious spots from the Radom series did not exceed 30 units. In the Syrian samples, this limit was higher at 44 units. These results were confirmed by histology and radiography. The DD laser provided good results in detecting dentine carious lesions in historical material, but its efficiency in diagnosing early caries (caries incipiens) remains uncertain based on the presented series.

  14. Coupling of Smoothed Particle Hydrodynamics with Finite Volume method for free-surface flows

    Science.gov (United States)

    Marrone, S.; Di Mascio, A.; Le Touzé, D.

    2016-04-01

    A new algorithm for the solution of free surface flows with large front deformation and fragmentation is presented. The algorithm is obtained by coupling a classical Finite Volume (FV) approach, that discretizes the Navier-Stokes equations on a block structured Eulerian grid, with an approach based on the Smoothed Particle Hydrodynamics (SPH) method, implemented in a Lagrangian framework. The coupling procedure is formulated in such a way that each solver is applied in the region where its intrinsic characteristics can be exploited in the most efficient and accurate way: the FV solver is used to resolve the bulk flow and the wall regions, whereas the SPH solver is implemented in the free surface region to capture details of the front evolution. The reported results clearly prove that the combined use of the two solvers is convenient from the point of view of both accuracy and computing time.

  15. Transitions between smooth and complex stick-slip sliding of surfaces

    Science.gov (United States)

    Gourdon, Delphine; Israelachvili, Jacob N.

    2003-08-01

    Shear measurements were performed on mica surfaces with molecularly thin films of squalane (C30H62) confined between them. Squalane is a branched hydrocarbon liquid that can be in the liquid, glassy, or liquid-crystalline state under confinement. The friction forces, especially the transitions between smooth and intermittent (e.g., stick-slip) sliding, were measured over a wider range of applied loads (pressures), sliding velocities (shear rates), and temperatures than in previous studies. The results reveal that, depending on the conditions, qualitatively different behavior can arise in the same system. These include both abrupt and continuous transitions, both upper and lower critical transition temperatures, short and very long transient effects, and chaotic, sawtooth, or sinusoidal stick-slip that can slowly decay with time or distance sheared. The differences between these branched and simpler, e.g., spherical, unbranched molecules are compared, as well as with unlubricated (dry) surfaces and macroscopic (geological) systems.

  16. A computational study of high-speed microdroplet impact onto a smooth solid surface

    CERN Document Server

    Feng, James Q

    2016-01-01

    Numerical solutions of high-speed microdroplet impact onto a smooth solid surface are computed, using the interFoam VoF solver of the OpenFOAM CFD package. Toward the solid surface, the liquid microdroplet is moving with an impinging gas flow, simulating the situation of ink droplets being deposited onto substrate with a collimated mist jet in the Optomec Aerosol Jet printing process. The computed values of maximum spread factor, for the range of parameters of practical interest to Aerosol Jet printing, were found in very good agreement with some of the correlation formulas proposed by previous authors in the literature. Combining formulas selected from different authors with appropriate modifications yields a maximum spread factor formula that can be used for first-order evaluations of deposited in droplet size during the Aerosol Jet technology development. The computational results also illustrate droplet impact dynamics with lamella shape evolution throughout the spreading, receding-relaxation, and wetting...

  17. Wettability influence on the onset temperature of pool boiling: Experimental evidence onto ultra-smooth surfaces.

    Science.gov (United States)

    Bourdon, B; Bertrand, E; Di Marco, P; Marengo, M; Rioboo, R; De Coninck, J

    2015-07-01

    In this article we study systematically the effect of wettability on the onset of boiling on the same nanometrically smooth surface. By grafting different monolayers of molecules, we were able to explore the wettability from the equilibrium static contact angle, θ0=0° to θ0=110°, without changing the surface topography. The superheat temperature at the onset of pool boiling was measured and eventually a non-classical trend of TONB as a function of wettability was observed. The nucleation site densities for the different grafting cases were also measured by image analysis. Moreover, we propose a novel theoretical interpretation to this phenomenon linking nucleation and the molecular diffusion coefficient. MD simulation results support this approach. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Feature-preserving surface mesh smoothing via suboptimal Delaunay triangulation ☆

    Science.gov (United States)

    Gao, Zhanheng; Yu, Zeyun; Holst, Michael

    2012-01-01

    A method of triangular surface mesh smoothing is presented to improve angle quality by extending the original optimal Delaunay triangulation (ODT) to surface meshes. The mesh quality is improved by solving a quadratic optimization problem that minimizes the approximated interpolation error between a parabolic function and its piecewise linear interpolation defined on the mesh. A suboptimal problem is derived to guarantee a unique, analytic solution that is significantly faster with little loss in accuracy as compared to the optimal one. In addition to the quality-improving capability, the proposed method has been adapted to remove noise while faithfully preserving sharp features such as edges and corners of a mesh. Numerous experiments are included to demonstrate the performance of the method. PMID:23580890

  19. Optimal smoothing length scale for actuator line models of lifting surfaces

    CERN Document Server

    Martinez-Tossas, Luis A

    2015-01-01

    The actuator line model (ALM) is a commonly used method to represent lifting surfaces such as wind turbine blades within Large-Eddy Simulations (LES). In ALM the lift and drag forces are replaced by an imposed body force which is typically smoothed over several grid points using a Gaussian kernel with some prescribed smoothing width $\\epsilon$. To date, the choice of $\\epsilon$ has most often been based on numerical considerations mostly related to the grid spacing used in LES. However, especially for finely resolved LES with grid spacings on the order or smaller than the chord-length of the blade, the best choice of $\\epsilon$ is not known. Focusing first on the lift force, here we find $\\epsilon$ and the force center location that minimize the square difference between the velocity fields obtained from solving 2D potential flow over Joukowski airfoils and solving the Euler equations including the imposed body force. The latter solution is found for the linearized problem, and is valid for small angles of at...

  20. Investigations of influence of vibration smoothing conditions of geometrical structure on machined surfaces

    Science.gov (United States)

    Bańkowski, D.; Spadło, S.

    2017-02-01

    The paper presents influence of the type of abrasive media on the operating parameters of the surface of components made of composite ceramic-glass, coated with a layer of antiferromagnetic. The research presents the possibilities offered by the use of resin bonded media with different intensities abrasive, understood as different content of abrasive grains. There were used Rollwasch smoothing media PB series – resin plastic media. Media were cone-shaped, with different abrasive properties (10%, 50% and 85%). The process was carried out by using chemical compounds - liquid supportive ME series L100 A22 / NF. Attention has also been given to the relation between the properties of abrasive media and surfaces that can be obtained after polishing with porcelain media and deburring with resin bonded media. As the output surface used the disc of hard drive. Then, to analysis of the possibility various kinds of abrasive media in vibratory finishing the analysis of surface texture with an optical profilometer Talysurf CCI Lite - Taylor Hobson were done. As a result of the effects polishing and deburring using vibratory finishing were compared.

  1. Low-damage surface smoothing of laser crystallized polycrystalline silicon using gas cluster ion beam

    Science.gov (United States)

    Tokioka, H.; Yamarin, H.; Fujino, T.; Inoue, M.; Seki, T.; Matsuo, J.

    2007-04-01

    Surface smoothing of laser crystallized polycrystalline silicon (poly-Si) films using gas cluster ion beam (GCIB) technology has been studied. It is found that both SF6-GCIB and O2-GCIB decrease the height of hillocks and reduce the surface roughness of the irradiated films. The mean surface roughness value of poly-Si films was reduced from 10.8 nm to 2.8 nm by SF6-GCIB irradiation at 80°. Ultraviolet reflectance measurement reveals that GCIB irradiation causes damage near-surface of the poly-Si films. Formation of the damage, however, can be suppressed by using GCIB irradiation at high incident angle. Effect of GCIB irradiation in a metal-insulator-semiconductor (MIS) capacitor has also been investigated. The capacitance-voltage curves of MIS capacitor with SF6-GCIB irradiation are distorted. On the contrary, the distortion is reduced by O2-GCIB irradiation at 80, which suggests that electrical-activated damage of the films can be decreased by using O2-GCIB irradiation.

  2. Dependence of surface smoothing, sputtering and etching phenomena on cluster ion dosage

    CERN Document Server

    Song, J H; Choi, W K

    2002-01-01

    The dependence of surface smoothing and sputtering phenomena of Si (1 0 0) solid surfaces irradiated by CO sub 2 cluster ions on cluster-ion dosage was investigated using an atomic force microscope. The flux and total ion dosage of impinging cluster ions at the acceleration voltage of 50 kV were fixed at 10 sup 9 ions/cm sup 2 s and were scanned from 5x10 sup 1 sup 0 to 5x10 sup 1 sup 3 ions/cm sup 2 , respectively. The density of hillocks induced by cluster ion impact was gradually increased with the dosage up to 5x10 sup 1 sup 1 ions/cm sup 2 , which caused that the irradiated surface became rough from 0.4 to 1.24 nm in root-mean-square roughness (sigma sub r sub m sub s). At the boundary of the ion dosage of 10 sup 1 sup 2 ions/cm sup 2 , the density of the induced hillocks was decreased and sigma sub r sub m sub s was about 1.21 nm, not being deteriorated further. At the dosage of 5x10 sup 1 sup 3 ions/cm sup 2 , the induced hillocks completely disappeared and the surface became very flat as much as sigma...

  3. Clifford groups of quantum gates, BN-pairs and smooth cubic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Planat, Michel [Institut FEMTO-ST, CNRS, 32 Avenue de l' Observatoire, F-25044 Besancon (France); Sole, Patrick [CNRS I3S, Les Algorithmes, Euclide B, 2000 route des Lucioles, BP 121, 06903 Sophia Antipolis (France)

    2009-01-30

    The recent proposal (Planat and Kibler 2008 arXiv:0807.3650 [quant-ph]) of representing Clifford quantum gates in terms of unitary reflections is revisited. In this communication, the geometry of a Clifford group G is expressed as a BN-pair, i.e. a pair of subgroups B and N that generate G, is such that intersection H = B intersection N is normal in G, the group W = N/H is a Coxeter group and two extra axioms are satisfied by the double cosets acting on B. The BN-pair used in this decomposition relies on the swap and match gates already introduced for classically simulating quantum circuits (Jozsa and Miyake 2008 arXiv:0804.4050 [quant-ph]). The two- and three-qubit cases are related to the configuration with 27 lines on a smooth cubic surface. (fast track communication)

  4. Experimental Study of Turbulent Boundary Layers on Groove/Smooth Flat Surfaces

    Institute of Scientific and Technical Information of China (English)

    Hongwei MA; Qiao TIAN; Hui WU

    2005-01-01

    This paper presents an experimental investigation of the turbulent boundary layers on both groove and smooth flat surfaces. The flow structures were shown in a water tunnel using the hydrogen-bubble flow visualization technique. The measurement results indicate that: (1) the grooves can effectively reduce accumulation of low-speed fluids, decrease the number of the low-speed streaks and depress oscillation of the streaks in the sublayer; (2) the grooves can restrain forming of the horseshoe vortices in the buffer region; (3) the grooves bate oscillation and kinking of the quasi-streamwise vortices and restrain production of the hairpin vortices and the ring vortices, reducing both frequency and intensity of the turbulence bursting; (4) the grooves directly affect the flow structures in the sublayer of the boundary layer and then modulate the flow field up to the buffer region and the logarithmic region by restraining development and interaction of the vortices.

  5. A Computational Study of High-Speed Microdroplet Impact onto a Smooth Solid Surface

    Directory of Open Access Journals (Sweden)

    J. Q. Feng

    2017-01-01

    Full Text Available Numerical solutions of high-speed microdroplet impact onto a smooth solid surface are computed, using the interFoam VoF solver of the OpenFOAM® CFD package. Toward the solid surface, the liquid microdroplet is moving with an impinging gas flow, simulating the situation of ink droplets being deposited onto substrate with a collimated mist jet in the Optomec Aerosol Jet® printing process. For simplicity and computational efficiency, axisymmetric incompressible flow is assumed here for the free-surface fluid dynamic problem. The computed values of maximum spread factor ξ, for the range of parameters relevant to Aerosol Jet® printing, are found in good agreement with some of the correlation formulas proposed by previous authors in the literature. A formula of improved accuracy is then obtained for evaluating ξ of Aerosol Jet® deposited droplets, by combining selected formulas from different authors with appropriate modifications. The computational results also illustrate droplet impact dynamics with lamella shape evolution throughout the spreading, receding-relaxation, and wetting equilibrium phases, consistent with that observed and described by many authors. This suggests a scale-invariant nature of the basic droplet impact behavior such that experiments with larger droplets at the same nondimensional parameter values may be applicable for studying microdroplet impact dynamics. Significant free surface oscillations can be observed with low viscosity droplets. The border line between free surface oscillations and aperiodic creeping to the capillary equilibrium shape appears at Oh ∼ 0.25. Droplet bouncing after receding is prompted with large contact angles at solid surface (as consistent with findings reported in the literature, but can be suppressed by increasing the droplet viscosity.

  6. Study of CO2 laser smoothing of surface roughness in fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen, N; Matthews, J; Fair, J E; Britten, J A; Nguyen, H T; Cooke, D; Elhadj, S; Henshaw, D; Guss, G M; Guss, G M; Yang, T

    2009-11-03

    Small micrometer-sized roughness on optical surfaces, caused by laser damage and/or redeposition of laser ablated material, can cause local electric field intensification which may lead to damage initiation both on the optics and/or downstream. We examined the smoothing of etched periodic surface structures on SiO{sub 2} substrate with 10.6 {micro}m CO{sub 2} laser using atomic force microscopy. The characteristic surface tension driven mass flow of the glass under different laser parameters were simulated using computational fluid dynamics and correlated with experimental results. We found that during CO{sub 2} laser polishing the estimate viscosity of the silica glass appears to be higher than typical literature values measured at a temperature similar to the laser heating conditions. This discrepancy can be explained by the observation that at high temperature, a significant portion of the hydroxyl content in the layer of heated silica glass can diffuse out resulting in a much stiffer glass.

  7. Super-aperture metrology: overcoming a fundamental limit in imaging smooth highly curved surfaces.

    Science.gov (United States)

    Liu, J; Liu, C; Tan, J; Yang, B; Wilson, T

    2016-03-01

    The imaging of smooth, highly curved or tilted surfaces is widely recognized as one of the most challenging and unsolved problems in optical imaging and metrology today. The reason is that even when such surfaces are imaged using high aperture microscope objectives the steepness of the features causes the light to be reflected in such a way that it is not captured by the lens. This is true even in the limiting case of unity numerical aperture since the illuminating light may also be reflected in the forward direction. In order to overcome this fundamental problem we have developed a method whereby such specimens are covered with a readily removable organic fluorescent film thereby creating an isotropic scattering surface. We show that we are readily able to detect slopes with angles close 90° using a 0.75 NA objective--an 82% improvement over the theoretical aperture limit. Issues of variation in film thickness deposition are shown to be readily accommodated. This approach may be used with other fluorophore materials, organic or inorganic, since there is no need for biocompatibility in this application.

  8. Deposited nanohelices on smooth surface: morphology and SERS application (Conference Presentation)

    Science.gov (United States)

    Jen, Yi-Jun; Liu, Wei-Chih; Huang, Yu-Jie; Weng Lin, Yueh

    2016-10-01

    Metal nanohelix arrays have been fabricated using glancing angle deposition. Comparing with method of substrate patterning, nanohelices with average arm width of 32 nm, pitch length of 34 nm and radius of curvature around 12.5 nm grew on a regular seeded layer with period of 79 nm and average seed diameter of 14 nm. In order to mass produce metal nanohelices, smooth substrates were adopted to deposited nanohelix arrays. Due to shadowing effect achieved under substrate cooling, the silver and gold nanohelix arrays could be grown successfully on smooth substrates by well controlling the substrate spin rate with respect to the deposition rate. In this work, the thickness of deposition monitored by quartz monitor was kept at 0.3 nm/s. The substrate was cooled to a low temperature around -10oC. The average arm width, pitch length, radius of curvature and spacer between nanohelices vary with deposition angle are investigated here. The morphology of nanohelix varies with different deposition angles (from 86o to 80o) were also to be investigated. In this work, the average space between adjacent nanohelices and radius of curvature were reduced and increased by increasing the deposition angle, respectively. The average pitch of each nanohelix array was low dependent on the deposition angle. The overlap effect occurs between adjacent nanohelices and the gaps between nanohelices support local field enhancement. The area associated local field enhancement called hot spots. Surface-enhanced Raman scattering (SERS) signals from nanostructured thin films were measured and compared with near-field simulations.

  9. Numerical simulation of effect of bionic V-riblet non-smooth surface on tire anti-hydroplaning

    Institute of Scientific and Technical Information of China (English)

    周海超; 王国林; 杨建; 薛开鑫

    2015-01-01

    Inspired by the idea that bionic non-smooth surfaces (BNSS) can reduce fluid adhesion and resistance, and the effect of bionic V-riblet non-smooth structure arranged in tire tread pattern grooves surface on anti-hydroplaning performance was investigated by using computational fluid dynamics (CFD). The physical model of the object (model of V-riblet surface distribution, hydroplaning model) and SSTk−ω turbulence model were established for numerical analysis of tire hydroplaning. With the help of a orthogonal table L16(45), the parameters of V-riblet structure design compared to the smooth structure were analyzed, and obtained the priority level of the experimental factors as well as the best combination within the scope of the experiment. The simulation results show that V-riblet structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, the preferred type of V-riblet non-smooth structure was arranged on the bottom of tire grooves for hydroplaning performance analysis. The results show that bionic V-riblet non-smooth structure can effectively increase hydroplaning velocity and improve tire anti-hydroplaning performance. Bionic design of tire tread pattern grooves is a good way to promote anti-hydroplaning performance without increasing additional groove space, so that tire grip performance and roll noise are avoided due to grooves space enlargement.

  10. Smoothing potential energy surface of proteins by hybrid coarse grained approach

    Science.gov (United States)

    Lu, Yukun; Zhou, Xin; OuYang, ZhongCan

    2017-05-01

    Coarse-grained (CG) simulations can more efficiently study large conformational changes of biological polymers but usually lose accuracies in the details. Lots of different hybrid models involving multiple different resolutions have been developed to overcome the difficulty. Here we propose a novel effective hybrid CG (hyCG) approach which mixes the fine-grained interaction and its average in CG space to form a more smoothing potential energy surface. The hyCG approximately reproduces the potential of mean force in the CG space, and multiple mixed potentials can be further combined together to form a single effective force field for achieving both high efficiency and high accuracy. We illustrate the hyCG method in Trp-cage and Villin headpiece proteins to exhibit the folding of proteins. The topology of the folding landscape and thus the folding paths are preserved, while the folding is boosted nearly one order of magnitude faster. It indicates that the hyCG approach could be applied as an efficient force field in proteins. Project supported by the National Basic Research Program of China (Grant No. 2013CB932803), the National Natural Science Foundation of China (Grant No. 11574310), and the Joint NSFC-ISF Research Program, jointly funded by the National Natural Science Foundation of China and the Israel Science Foundation (Grant No. 51561145002).

  11. Towards accelerating Smoothed Particle Hydrodynamics simulations for free-surface flows on multi-GPU clusters

    CERN Document Server

    Valdez-Balderas, Daniel; Rogers, Benedict D; Crespo, Alejandro J C

    2012-01-01

    Starting from the single graphics processing unit (GPU) version of the Smoothed Particle Hydrodynamics (SPH) code DualSPHysics, a multi-GPU SPH program is developed for free-surface flows. The approach is based on a spatial decomposition technique, whereby different portions (sub-domains) of the physical system under study are assigned to different GPUs. Communication between devices is achieved with the use of Message Passing Interface (MPI) application programming interface (API) routines. The use of the sorting algorithm radix sort for inter-GPU particle migration and sub-domain halo building (which enables interaction between SPH particles of different subdomains) is described in detail. With the resulting scheme it is possible, on the one hand, to carry out simulations that could also be performed on a single GPU, but they can now be performed even faster than on one of these devices alone. On the other hand, accelerated simulations can be performed with up to 32 million particles on the current architec...

  12. Boiling heat transfer enhancement of nanofluids on a smooth surface with agitation

    Science.gov (United States)

    Kong, Xin; Qi, Baojin; Wei, Jinjia; Li, Wei; Ding, Jie; Zhang, Yonghai

    2016-12-01

    The pool boiling heat transfer performance on a smooth silicon chip surface with agitation was experimentally investigated in this study. The nanofluids (Ag/alcohol) of 0.02 % volume concentration and ethyl alcohol with purification over 99.9 % were the two contrast working fluids. For each group, subcoolings of 40, 50 and 60 K were conducted under atmospheric pressure. To enhance the heat transfer performance, an agitating device was fixed above the top of the chip. The experimental results indicated that nanofluids could enhance the heat transfer performance especially in the nucleate boiling region. The heat transfer coefficient was significantly increased with nanofluids, while the critical heat flux (CHF) was nearly not changed. In the agitation Reynolds number of 20,300, the heat transfer performance of nanofluids was significantly enhanced in the convection region, and the CHF was increased by more than 25 % for all groups. This boiling phenomenon was observed for both nanofluids and alcohol groups. Meanwhile, the boiling curves of different liquid subcoolings in the nucleate region were quite similar to each other under agitation.

  13. Influence of non-smooth surface on tribological properties of glass fiber-epoxy resin composite sliding against stainless steel under natural seawater lubrication

    Science.gov (United States)

    Wu, Shaofeng; Gao, Dianrong; Liang, Yingna; Chen, Bo

    2015-11-01

    With the development of bionics, the bionic non-smooth surfaces are introduced to the field of tribology. Although non-smooth surface has been studied widely, the studies of non-smooth surface under the natural seawater lubrication are still very fewer, especially experimental research. The influences of smooth and non-smooth surface on the frictional properties of the glass fiber-epoxy resin composite (GF/EPR) coupled with stainless steel 316L are investigated under natural seawater lubrication in this paper. The tested non-smooth surfaces include the surfaces with semi-spherical pits, the conical pits, the cone-cylinder combined pits, the cylindrical pits and through holes. The friction and wear tests are performed using a ring-on-disc test rig under 60 N load and 1000 r/min rotational speed. The tests results show that GF/EPR with bionic non-smooth surface has quite lower friction coefficient and better wear resistance than GF/EPR with smooth surface without pits. The average friction coefficient of GF/EPR with semi-spherical pits is 0.088, which shows the largest reduction is approximately 63.18% of GF/EPR with smooth surface. In addition, the wear debris on the worn surfaces of GF/EPR are observed by a confocal scanning laser microscope. It is shown that the primary wear mechanism is the abrasive wear. The research results provide some design parameters for non-smooth surface, and the experiment results can serve as a beneficial supplement to non-smooth surface study.

  14. Influence of Non-smooth Surface on Tribological Properties of Glass Fiber-epoxy Resin Composite Sliding against Stainless Steel under Natural Seawater Lubrication

    Institute of Scientific and Technical Information of China (English)

    WU Shaofeng; GAO Dianrong; LIANG Yingna; CHEN Bo

    2015-01-01

    With the development of bionics, the bionic non-smooth surfaces are introduced to the field of tribology. Although non-smooth surface has been studied widely, the studies of non-smooth surface under the natural seawater lubrication are still very fewer, especially experimental research. The influences of smooth and non-smooth surface on the frictional properties of the glass fiber-epoxy resin composite (GF/EPR) coupled with stainless steel 316L are investigated under natural seawater lubrication in this paper. The tested non-smooth surfaces include the surfaces with semi-spherical pits, the conical pits, the cone-cylinder combined pits, the cylindrical pits and through holes. The friction and wear tests are performed using a ring-on-disc test rig under 60 N load and 1000 r/min rotational speed. The tests results show that GF/EPR with bionic non-smooth surface has quite lower friction coefficient and better wear resistance than GF/EPR with smooth surface without pits. The average friction coefficient of GF/EPR with semi-spherical pits is 0.088, which shows the largest reduction is approximately 63.18% of GF/EPR with smooth surface. In addition, the wear debris on the worn surfaces of GF/EPR are observed by a confocal scanning laser microscope. It is shown that the primary wear mechanism is the abrasive wear. The research results provide some design parameters for non-smooth surface, and the experiment results can serve as a beneficial supplement to non-smooth surface study.

  15. On the geometry of a smooth model of a fibre product of families of K3 surfaces

    Science.gov (United States)

    Nikol'skaya, O. V.

    2014-02-01

    The Hodge conjecture on algebraic cycles is proved for a smooth projective model X of a fibre product X_1\\times_C X_2 of nonisotrivial 1-parameter families of K3 surfaces (possibly with degeneracies) X_{k} \\to C ( k=1,2) over a smooth projective curve C under the assumption that, for generic geometric fibres X_{1s} and X_{2s}, the ring \\operatorname{End}_{\\operatorname{Hg}(X_{1s})}\\operatorname{NS}_{ Q}(X_{1s})^{\\perp} is an imaginary quadratic field, \\operatorname{rank}\\operatorname{NS}(X_{1s})\

  16. Surface smoothing effect of an amorphous thin film deposited by atomic layer deposition on a surface with nano-sized roughness

    Directory of Open Access Journals (Sweden)

    W. S. Lau

    2014-02-01

    Full Text Available Previously, Lau (one of the authors pointed out that the deposition of an amorphous thin film by atomic layer deposition (ALD on a substrate with nano-sized roughness probably has a surface smoothing effect. In this letter, polycrystalline zinc oxide deposited by ALD onto a smooth substrate was used as a substrate with nano-sized roughness. Atomic force microscopy (AFM and cross-sectional transmission electron microscopy (XTEM were used to demonstrate that an amorphous aluminum oxide thin film deposited by ALD can reduce the surface roughness of a polycrystalline zinc oxide coated substrate.

  17. Preparation of Smooth Surface TiO2 Photoanode for High Energy Conversion Efficiency in Dye-Sensitized Solar Cells

    OpenAIRE

    Sasipriya Kathirvel; Huei-Siou Chen; Chaochin Su; Hsiue-Hsyan Wang; Chung-Yen Li; Wen-Ren Li

    2013-01-01

    Dye-sensitized solar cells (DSSCs) based on a TiO2 photoanode have been considered as an alternative source in the field of renewable energy resources. In DSSCs, photoanode plays a key role to achieve excellent photo-to-electric conversion efficiency. The surface morphology, surface area, TiO2 crystal phase, and the dispersion of TiO2 nanoparticles are the most important factors influencing the properties of a photoanode. The smooth TiO2 surface morphology of the photoanode indicates closely ...

  18. Effects of electrolytic composition on the electric double-layer capacitance at smooth-surface carbon electrodes in organic media

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In-Tae; Egashira, Minato; Yoshimoto, Nobuko [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1, Tokiwadai, Ube, 755-8611 (Japan); Morita, Masayuki, E-mail: morita@yamaguchi-u.ac.j [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1, Tokiwadai, Ube, 755-8611 (Japan)

    2010-09-01

    As a fundamental research on the optimization of electrolyte composition in practical electrochemical capacitor device, double-layer capacitance at Glassy Carbon (GC) and Boron-doped Diamond (BDD), as typical smooth-surface carbon electrodes, has been studied as a function of the electrolyte composition in organic media. Specific capacitance (differential capacitance: F cm{sup -2}) determined by an AC impedance method, in which no contribution of mass-transport effects is included, corresponded well to integrated capacitance evaluated by conventional cyclic voltammetry. The specific capacitance at the GC electrode varied with polarized potential and showed clear PZC (potential of zero charge), while the potential dependence of the capacitance at BDD was very small. The effects of the solvent and the electrolytic salt on the capacitance behavior were common for both electrodes. That is, the sizes of the solvent molecule and the electrolytic ion (cation) strongly affected the capacitance at these smooth-surface carbon electrodes.

  19. A Mathematical and Numerically Integrable Modeling of 3D Object Grasping under Rolling Contacts between Smooth Surfaces

    Directory of Open Access Journals (Sweden)

    Suguru Arimoto

    2011-01-01

    Full Text Available A computable model of grasping and manipulation of a 3D rigid object with arbitrary smooth surfaces by multiple robot fingers with smooth fingertip surfaces is derived under rolling contact constraints between surfaces. Geometrical conditions of pure rolling contacts are described through the moving-frame coordinates at each rolling contact point under the postulates: (1 two surfaces share a common single contact point without any mutual penetration and a common tangent plane at the contact point and (2 each path length of running of the contact point on the robot fingertip surface and the object surface is equal. It is shown that a set of Euler-Lagrange equations of motion of the fingers-object system can be derived by introducing Lagrange multipliers corresponding to geometric conditions of contacts. A set of 1st-order differential equations governing rotational motions of each fingertip and the object and updating arc-length parameters should be accompanied with the Euler-Lagrange equations. Further more, nonholonomic constraints arising from twisting between the two normal axes to each tangent plane are rewritten into a set of Frenet-Serre equations with a geometrically given normal curvature and a motion-induced geodesic curvature.

  20. Below the Callus Surface: Applying Paleohistological Techniques to Understand the Biology of Bone Healing in Skeletonized Human Remains.

    Science.gov (United States)

    Assis, Sandra; Keenleyside, Anne

    2016-01-01

    Bone trauma is a common occurrence in human skeletal remains. Macroscopic and imaging scrutiny is the approach most currently used to analyze and describe trauma. Nevertheless, this line of inquiry may not be sufficient to accurately identify the type of traumatic lesion and the associated degree of bone healing. To test the usefulness of histology in the examination of bone healing biology, we used an integrative approach that combines gross inspection and microscopy. Six bone samples belonging to 5 adult individuals with signs of bone trauma were collected from the Human Identified Skeletal Collection from the Museu Bocage (Lisbon, Portugal). Previous to sampling, the lesions were described according to their location, morphology, and healing status. After sampling, the bone specimens were prepared for plane light and polarized light analysis. The histological analysis was pivotal: (1) to differentiate between types of traumatic lesions; (2) to ascertain the posttraumatic interval, and (3) to diagnose other associated pathological conditions. The outer surface of a bone lesion may not give a complete picture of the biology of the tissue's response. Accordingly, microscopic analysis is essential to differentiate, characterize, and classify trauma signs. © 2016 S. Karger AG, Basel.

  1. Simulations of flow mode distributions on rough fracture surfaces using a parallelized Smoothed Particle Hydrodynamics (SPH) model

    Science.gov (United States)

    Kordilla, J.; Shigorina, E.; Tartakovsky, A. M.; Pan, W.; Geyer, T.

    2015-12-01

    Under idealized conditions (smooth surfaces, linear relationship between Bond number and Capillary number of droplets) steady-state flow modes on fracture surfaces have been shown to develop from sliding droplets to rivulets and finally (wavy) film flow, depending on the specified flux. In a recent study we demonstrated the effect of surface roughness on droplet flow in unsaturated wide aperture fractures, however, its effect on other prevailing flow modes is still an open question. The objective of this work is to investigate the formation of complex flow modes on fracture surfaces employing an efficient three-dimensional parallelized SPH model. The model is able to simulate highly intermittent, gravity-driven free-surface flows under dynamic wetting conditions. The effect of surface tension is included via efficient pairwise interaction forces. We validate the model using various analytical and semi-analytical relationships for droplet and complex flow dynamics. To investigate the effect of surface roughness on flow dynamics we construct surfaces with a self-affine fractal geometry and roughness characterized by the Hurst exponent. We demonstrate the effect of surface roughness (on macroscopic scales this can be understood as a tortuosity) on the steady-state distribution of flow modes. Furthermore we show the influence of a wide range of natural wetting conditions (defined by static contact angles) on the final distribution of surface coverage, which is of high importance for matrix-fracture interaction processes.

  2. Preparation of Smooth Surface TiO2 Photoanode for High Energy Conversion Efficiency in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Sasipriya Kathirvel

    2013-01-01

    Full Text Available Dye-sensitized solar cells (DSSCs based on a TiO2 photoanode have been considered as an alternative source in the field of renewable energy resources. In DSSCs, photoanode plays a key role to achieve excellent photo-to-electric conversion efficiency. The surface morphology, surface area, TiO2 crystal phase, and the dispersion of TiO2 nanoparticles are the most important factors influencing the properties of a photoanode. The smooth TiO2 surface morphology of the photoanode indicates closely packed arrangement of TiO2 particles which enhance the light harvesting efficiency of the cell. In this paper, a smooth TiO2 photoanode has been successfully prepared using a well-dispersed anatase TiO2 nanosol via a simple hydrothermal process. The above TiO2 photoanode was then compared with the photoanode made from commercial TiO2 nanoparticle pastes. The morphological and structural analyses of both the aforementioned photoanodes were comprehensively characterized by scanning electron microscopy and X-ray diffraction analysis. The DSSC fabricated by using a-TiO2 nanosol-based photoelectrode exhibited an overall light conversion efficiency of 7.20% and a short-circuit current density of 13.34 mA cm−2, which was significantly higher than those of the DSSCs with the TiO2 nanoparticles-based electrodes.

  3. Detailed comparative study and a mechanistic model of resuspension of spherical particles from rough and smooth surfaces

    CERN Document Server

    Shnapp, Ron

    2014-01-01

    Resuspension of solid particles by a tornado-like vortex from surfaces of different roughness is studied using a three-dimensional particle tracking velocimetry (3D-PTV) method. By utilizing the three-dimensional information on particle positions, velocities and accelerations before, during and after the resuspension (lift-off) event, we demonstrate that the resuspension efficiency is significantly higher from the rough surface, and propose a mechanistic model of this peculiar effect. The results indicate that for all Reynolds numbers tested, the resuspension rate, as well as particle velocities and accelerations, are higher over the rough surface, as compared to the smooth counterpart. The results and the model can help to improve modeling and analysis of resuspension rates in engineering and environmental applications.

  4. Structural and chemical characteristics of atomically smooth GaN surfaces prepared by abrasive-free polishing with Pt catalyst

    Science.gov (United States)

    Murata, Junji; Sadakuni, Shun; Okamoto, Takeshi; Hattori, Azusa N.; Yagi, Keita; Sano, Yasuhisa; Arima, Kenta; Yamauchi, Kazuto

    2012-06-01

    This paper reports the structural and chemical characteristics of atomically flat gallium nitride (GaN) surfaces prepared by abrasive-free polishing with platinum (Pt) catalyst. Atomic force microscopy revealed regularly alternating wide and narrow terraces with a step height equivalent to that of a single bilayer on the flattened GaN surfaces, which originate from the differences in etching rate of two neighboring terraces. The material removal characteristics of the method for GaN surfaces were investigated in detail. We confirmed that an atomically smooth GaN surface with an extremely small number of surface defects, including pits and scratches, can be achieved, regardless of the growth method, surface polarity, and doping concentration. X-ray photoelectron spectroscopy showed that the flattening method produces clean GaN surfaces with only trace impurities such as Ga oxide and metallic Ga. Contamination with the Pt catalyst was also evaluated using total-reflection X-ray fluorescence analysis. A wet cleaning method with aqua regia is proposed, which markedly eliminates this Pt contamination without affecting the surface morphology.

  5. Hierarchical Genetic Algorithm for B-Spline Surface Approximation of Smooth Explicit Data

    OpenAIRE

    Garcia-Capulin, C. H.; F. J. Cuevas; Trejo-Caballero, G.; Rostro-Gonzalez, H.

    2014-01-01

    B-spline surface approximation has been widely used in many applications such as CAD, medical imaging, reverse engineering, and geometric modeling. Given a data set of measures, the surface approximation aims to find a surface that optimally fits the data set. One of the main problems associated with surface approximation by B-splines is the adequate selection of the number and location of the knots, as well as the solution of the system of equations generated by tensor pro...

  6. Native gallium adatoms discovered on atomically-smooth gallium nitride surfaces at low temperature.

    Science.gov (United States)

    Alam, Khan; Foley, Andrew; Smith, Arthur R

    2015-03-11

    In advanced compound semiconductor devices, such as in quantum dot and quantum well systems, detailed atomic configurations at the growth surfaces are vital in determining the structural and electronic properties. Therefore, it is important to investigate the surface reconstructions in order to make further technological advancements. Usually, conventional semiconductor surfaces (e.g., arsenides, phosphides, and antimonides) are highly reactive due to the existence of a high density of group V (anion) surface dangling bonds. However, in the case of nitrides, group III rich growth conditions in molecular beam epitaxy are usually preferred leading to group III (Ga)-rich surfaces. Here, we use low-temperature scanning tunneling microscopy to reveal a uniform distribution of native gallium adatoms with a density of 0.3%-0.5% of a monolayer on the clean, as-grown surface of nitrogen polar GaN(0001̅) having the centered 6 × 12 reconstruction. Unseen at room temperature, these Ga adatoms are strongly bound to the surface but move with an extremely low surface diffusion barrier and a high density saturation coverage in thermodynamic equilibrium with Ga droplets. Furthermore, the Ga adatoms reveal an intrinsic surface chirality and an asymmetric site occupation. These observations can have important impacts in the understanding of gallium nitride surfaces.

  7. New model for estimating the relationship between surface area and volume in the human body using skeletal remains.

    Science.gov (United States)

    Kasabova, Boryana E; Holliday, Trenton W

    2015-04-01

    A new model for estimating human body surface area and body volume/mass from standard skeletal metrics is presented. This model is then tested against both 1) "independently estimated" body surface areas and "independently estimated" body volume/mass (both derived from anthropometric data) and 2) the cylindrical model of Ruff. The model is found to be more accurate in estimating both body surface area and body volume/mass than the cylindrical model, but it is more accurate in estimating body surface area than it is for estimating body volume/mass (as reflected by the standard error of the estimate when "independently estimated" surface area or volume/mass is regressed on estimates derived from the present model). Two practical applications of the model are tested. In the first test, the relative contribution of the limbs versus the trunk to the body's volume and surface area is compared between "heat-adapted" and "cold-adapted" populations. As expected, the "cold-adapted" group has significantly more of its body surface area and volume in its trunk than does the "heat-adapted" group. In the second test, we evaluate the effect of variation in bi-iliac breadth, elongated or foreshortened limbs, and differences in crural index on the body's surface area to volume ratio (SA:V). Results indicate that the effects of bi-iliac breadth on SA:V are substantial, while those of limb lengths and (especially) the crural index are minor, which suggests that factors other than surface area relative to volume are driving morphological variation and ecogeographical patterning in limb prorportions.

  8. Application of atmospheric pressure plasma polishing method in machining of silicon ultra-smooth surfaces

    Institute of Scientific and Technical Information of China (English)

    Jufan ZHANG; Bo WANG; Shen DONG

    2008-01-01

    The modern optics industry demands rigorous surface quality with minimum defects, which presents challenges to optics machining technologies. There are always certain defects on the final surfaces of the compo-nents formed in conventional contacting machining proc-esses, such as micro-cracks, lattice disturbances, etc. It is especially serious for hard-brittle functional materials, such as crystals, glass and ceramics because of their special characteristics. To solve these problems, the atmospheric pressure plasma polishing (APPP) method is developed. It utilizes chemical reactions between reactive plasma and surface atoms to perform atom-scale material removal. Since the machining process is chemical in nature, APPP avoids the surface/subsurface defects mentioned above. As the key component, a capacitance coupled radio-fre-quency plasma torch is first introduced. In initial opera-tions, silicon wafers were machined as samples. Before applying operations, both the temperature distribution on the work-piece surface and the spatial gas diffusion in the machining process were studied qualitatively by finite element analysis. Then the following temperature measurement experiments demonstrate the formation of the temperature gradient on the wafer surface predicted by the theoretical analysis and indicated a peak temper-ature about 90℃ in the center. By using commercialized form talysurf, the machined surface was detected and the result shows regular removal profile that corresponds well to the flow field model. Moreover, the removal profile also indicates a 32 mm3/min removal rate. By using atomic force microscopy (AFM), the surface roughness was also measured and the result demonstrates an Ra 0.6 nm surface roughness. Then the element composition of the machined surface was detected and analyzed by X-ray photoelectron spectroscopy (XPS) technology. The results also demonstrate the occurrence of the anticipated main reactions. All the experiments have proved that

  9. Comparison of microfacet BRDF model to modified Beckmann-Kirchhoff BRDF model for rough and smooth surfaces.

    Science.gov (United States)

    Butler, Samuel D; Nauyoks, Stephen E; Marciniak, Michael A

    2015-11-02

    A popular class of BRDF models is the microfacet models, where geometric optics is assumed. In contrast, more complex physical optics models may more accurately predict the BRDF, but the calculation is more resource intensive. These seemingly disparate approaches are compared in detail for the rough and smooth surface approximations of the modified Beckmann-Kirchhoff BRDF model, assuming Gaussian surface statistics. An approximation relating standard Fresnel reflection with the semi-rough surface polarization term, Q, is presented for unpolarized light. For rough surfaces, the angular dependence of direction cosine space is shown to be identical to the angular dependence in the microfacet distribution function. For polished surfaces, the same comparison shows a breakdown in the microfacet models. Similarities and differences between microfacet BRDF models and the modified Beckmann-Kirchhoff model are identified. The rationale for the original Beckmann-Kirchhoff F(bk)(2) geometric term relative to both microfacet models and generalized Harvey-Shack model is presented. A modification to the geometric F(bk)(2) term in original Beckmann-Kirchhoff BRDF theory is proposed.

  10. Magnetic Bingham fluid-assisted deterministic polishing for super-smooth surfaces

    Institute of Scientific and Technical Information of China (English)

    CHENG Haobo; FENG Zhijing; WANG Yingwei; LEI Shuting

    2005-01-01

    The characteristics of magnetorheological finishing (MRF) technique such as the behavior of magnetic particles and the magnetic field distribution have been investigated. Based on the established theoretical model, material removal function and removal rate experiments involving a K9 glass mirror are designed and carried out. Further experiments are carried out to improve the surface roughness of the workpiece. The final surface roughness with an initial value of 17.58 nm reached 0.4351 nm rms after 35 min of deterministic MRF, and the AFM measurements on microstructures of the polished surface are also improved by 0.445 nm rms without obvious defects.

  11. Surface Smoothing of Blasted Glass Micro-Channels Using Abrasive Waterjet

    Energy Technology Data Exchange (ETDEWEB)

    Son, Sunggyun; Han, Solyi; Kim, Wookbae [Korea Polytechnic Univ., Siheung (Korea, Republic of); Sung, Inha [Hannam Univ., Daejeon (Korea, Republic of)

    2013-12-15

    Powder blasting, which is an efficient micromachining method for glass, silicon, and ceramics, has a critical disadvantage in that the surface finish is poor owing to the brittle fracture of materials. Low-pressure waterjet machining can be applied to smoothen the rough surface inside the blasted structure. In this study, the surface roughness and sectional dimension of micro-channels are observed during the repetitive application of a waterjet to blasted micro-channels. The asperities and subsurface cracks created by blasting are removed by waterjet machining. Along with the surface roughness, it is found that the sectional dimension increases and the edges of the finished micro-channel become slightly round. Finally, a microfluidic chip is machined by the blasting-waterjet process and a transparent microfluidic channel is obtained efficiently.

  12. Smooth-surface silver nanowire electrode with high conductivity and transparency on functional layer coated flexible film

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Hee; Lim, Sooman; Kim, Haekyoung, E-mail: hkkim@ynu.ac.kr

    2015-08-31

    Transparent conductive electrode (TCE) with silver nanowires has been widely studied as an alternative of indium tin oxide for flexible electronic or optical devices such as organic light-emitting diodes, and solar cells. However, it has an issue of surface roughness due to nanowire's intrinsic properties. Here, to achieve a smooth electrode with high conductivity and transmittance on polyethylene terephthalate (PET) substrates, a functional layer of poly(N-vinylpyrrolidone) (PVP) is utilized with a mechanical transfer process. The silver nanowire electrode on PVP-coated PET with low surface roughness of 9 nm exhibits the low sheet resistance of 18 Ω □{sup −1} and high transmittance of 87.6%. It is produced by transferring the silver nanowire electrode spin-coated on the glass to PVP-coated PET using a pressure of 10 MPa for 10 min. Silver nanowire electrode on PVP-coated PET demonstrates the stable sheet resistance of 18 Ω □{sup −1} after the mechanical taping test due to strong adhesion between PVP functional layer and silver nanowires. Smooth TCE with silver nanowires could be proposed as a transparent electrode for flexible electronic or optical devices, which consist of thin electrical active layers on TCE. - Highlights: • Silver nanowire (Ag NWs) transparent electrodes were fabricated on flexible film. • Flexible film was coated with poly N-vinylpyrrolidone (PVP). • PVP layer plays roles as an adhesive layer and matrix in electrode. • Ag NWs electrode exhibited with low surface roughness of 9 nm. • Ag NWs electrode has a low resistance (18 Ω ☐{sup −1}) and high transmittance (87.6%)

  13. Surface-mediated functional gene delivery: an effective strategy for enhancing competitiveness of endothelial cells over smooth muscle cells.

    Science.gov (United States)

    Chang, Hao; Ren, Ke-feng; Wang, Jin-Lei; Zhang, He; Wang, Bai-liang; Zheng, Shan-mei; Zhou, Yuan-yuan; Ji, Jian

    2013-04-01

    The non-biorecognition of general biomaterials and inherent biospecificity of biological systems pose key challenges to the optimal functions of medical devices. In this study, we constructed the surface-mediated functional gene delivery through layer-by-layer self-assembly of protamine sulfate (PrS) and plasmid DNA encoding hepatocyte growth factor (HGF), aiming at specific enhancing endothelial cells (EC) compeititiveness over smooth muscle cells (SMC). Characterizations of the (PrS/HGF-pDNA) multilayered films present the linear buildup with homogeneous and flat topographical feature. The amount of DNA can be easily controlled. By using these multilayered films, both human umbilical vein endothelial cells (HUVEC) and human umbilical artery smooth muscle cells (HUASMC) can be directly transfected when they contact with the multilayered films. On transfection, increasing secretion of HGF has been detected in both HUVEC and HUASMC culture, which leads to selective promotion of HUVEC proliferation. In the co-culture experiment, we also exhibit the promoted and hindered growth of HUVEC and HUASMC, respectively, which could be attributed to the inverse influence of HUVEC on HUASMC. These results collectively demonstrate that our system can be served as a powerful tool for enhancing competitiveness of EC over SMC, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy.

  14. Slip length measurement of confined air flow on three smooth surfaces.

    Science.gov (United States)

    Pan, Yunlu; Bhushan, Bharat; Maali, Abdelhamid

    2013-04-01

    An experimental measurement of the slip length of air flow close to three different solid surfaces is presented. The substrate was driven by a nanopositioner moving toward an oscillating glass sphere glued to an atomic force microscopy (AFM) cantilever. A large separation distance was used to get more effective data. The slip length value was obtained by analyzing the amplitude and phase data of the cantilever. The measurements show that the slip length does not depend on the oscillation amplitude of the cantilever. Because of the small difference among the slip lengths of the three surfaces, a simplified analysis method was used. The results show that on glass, graphite, and mica surfaces the slip lengths are 98, 234, and 110 nm, respectively.

  15. A Multi Asperity Model of Contact Between a Smooth Sphere and a Rough Flat Surface in Presence of Adhesion

    Directory of Open Access Journals (Sweden)

    K. Saha

    2011-03-01

    Full Text Available Multi asperity elastic-plastic adhesive contact between a smooth sphere and a rough flat surface is considered. To incorporate the effect of adhesion, JKR (Johnson–Kendall–Roberts contacts are assumed and the mixed asperity contact model for a sphere with rough flats, developed by Kagami et al, is used. The results are obtained in terms of plots of radial pressure distribution, contact radius versus load, and compliance versus load and they are studied for different conditions that arise from varying loading and material parameters. The results obtained exhibit a negative pressure region at the edge of contact. It is observed that larger sphere radius gives lower pressure distribution and lower compliance.

  16. Effects of Methanol on Wettability of the Non-Smooth Surface on Butterfly Wing

    Institute of Scientific and Technical Information of China (English)

    Yan Fang; Gang Sun; Qian Cong; Guang-hua Chen; Lu-quan Ren

    2008-01-01

    The contact angles of distilled water and methanol solution on the wings of butterflies were determined by a visual contact angle measuring system. The scale structures of the wings were observed using scanning electron microscopy, The influence of the scale micro- and ultra-structure on the wettability was investigated. Results show that the contact angle of distilled water on the wing surfaces varies from 134.0° to 159.2°. High hydrophobicity is found in six species with contact angles greater than 150°. The wing surfaces of some species are not only hydrophobic but also resist the wetting by methanol solution with 55% concentration. Only two species in Parnassius can not resist the wetting because the micro-structure (spindle-like shape) and ultra-structure (pinnule-like shape) of the wing scales are remarkably different from that of other species. The concentration of methanol solution for the occurrence of spreading/wetting on the wing surfaces of different species varies from 70% to 95%. After wetting by methanol solution for 10 min, the distilled water contact angle on the wing surface increases by 0.8°-2.1°, showing the promotion of capacity against wetting by distilled water.

  17. Patterned hydrophobic and hydrophilic surfaces of ultra-smooth nanocrystalline diamond layers

    Science.gov (United States)

    Mertens, M.; Mohr, M.; Brühne, K.; Fecht, H. J.; Łojkowski, M.; Święszkowski, W.; Łojkowski, W.

    2016-12-01

    In this work, we show that ultra nanocrystalline diamond (UNCD) surfaces have been modified to add them hydrophobic and hydrophilic properties. The nanocrystalline diamond films were deposited using the hot filament chemical vapor deposition (HFCVD) technique. This allows growing diamond on different substrates which can be even 3D or structured. Silicon and, for optical applications, transparent quartz glass are the preferred substrates for UNCD layers growth. Fluorine termination leads to strong hydrophobic properties as indicated by a high contact angle for water of more than 100°. Hydrogen termination shows lesser hydrophobic behavior. Hydrophilic characteristics has been realised with oxygen termination. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) measurements confirm the oxygen and fluorine- termination on the nanocrystalline diamond surface. Further, by micropatterning using photolithography, multi-terminated layers have been created with both hydrophobic and hydrophilic areas. In addition, we have shown that retermination is achieved, and the properties of the surface have been changed from hydrophobic to hydrophilic and vice versa. Micro- roughness and stress in the grown film influences slightly the wetting angle as well. The opportunity to realize local differences in hydrophobicity on nanocrystalline diamond layers, in any size or geometry, offers interesting applications for example in microbiological investigations. Multi-terminated arrays show identical surface roughness and at the same time differences in hydrophobicity. These arrays have been visualized with scanning electron microscopy (SEM) and lateral force microscopy (LFM).

  18. Surface smoothness requirements for the mirrors of the IXO X-ray telescope

    CERN Document Server

    Spiga, D

    2015-01-01

    The International X-ray Observatory (IXO) is a very ambitious mission, aimed at the X-ray observation of the early Universe. This makes IXO extremely demanding in terms of effective area and angular resolution. In particular, the HEW requirement below 10 keV is 5 arcsec Half-Energy Width (HEW). At higher photon energies, the HEW is expected to increase, and the angular resolution to be correspondingly degraded, due to the increasing relevance of the X-ray scattering off the reflecting surfaces. Therefore, the HEW up to 40 keV is required to be better than 30 arcsec, even though the IXO goal is to achieve an angular resolution as close as possible to 5 arcsec also at this energy. To this end, the roughness of the reflecting surfaces has to not exceed a tolerance, expressed in terms of a surface roughness PSD (Power-Spectral-Density). In this work we provide such tolerances by simulating the HEW scattering term for IXO, assuming a specific configuration for the optical module and different hypotheses on the PSD...

  19. Hydrophobicity mechanism of non-smooth pattern on surface of butterfly wing

    Institute of Scientific and Technical Information of China (English)

    FANG Yan; SUN Gang; WANG TongQing; CONG Qian; REN LuQuan

    2007-01-01

    Twenty-nine species (24 genera, 6 families) of butterflies typical and common in northeast China were selected to make qualitative and quantitative studies on the pattern, hydrophobicity and hydrophobicity mechanism by means of scanning electron microscopy and contact angle measuring system. The scale surface is composed of submicro-class vertical gibbosities and horizontal links. The distance of scale is 48-91 μm, length 65-150 μm, and width 35-70 μm. The distance of submicro-class vertical gibbosities on scale is 1.06-2.74 μm, height 200-900 nm, and width 200-840 nm. The better hydrophobicity on the surface of butterfly wing (static contact angle 136.3°-156.6°) is contributed to the co-effects of micro-class scale and submicro-class vertical gibbosities on the wing surface. The Cassie equation was revised, and new mathematical models and equations were established.

  20. Polymer Droplet Dynamic Wetting Measurement at the Nanometer Scale on Smooth Surfaces Using Atomic Force Microscopy

    Science.gov (United States)

    Soleymaniha, Mohammadreza; Felts, Jonathan Robert; Anml Team

    2016-11-01

    Fluid spreading is a complex phenomenon driven strongly by intermolecular forces that requires nanometer scale microscopy to observe and understand. We present a technique for measuring molten polymer spreading dynamics with nanometer scale spatial resolution at elevated temperatures on sapphire, silicon oxide and mica using tapping-mode atomic force microscopy (AFM). The experimental setup is used to measure the spreading dynamics of polystyrene droplets with 2 μ m diameters at 115-175 C. Custom image processing algorithms realize the droplet height, radius, volume and contact angle of the droplet over time. The contact angle evolution followed a power law with time with experimental exponent values of -0.26, -0.08, and -0.2 for sapphire, silicon oxide, and mica, respectively at 115 C. The non-zero steady state contact angles result in a slower evolution of contact angle with time compared to Tanner's Law, as expected. We observe local crystallinity on the molten droplet surface, where crystalline structures appear to nucleate at the contact line and migrate toward the top of the droplet. Increasing the temperature from 115 C to 175 C reduced surface crystallinity from 35% to 12%, consistent with increasingly energetically favorable amorphous phase as the temperature approaches the melting temperature. This platform provides a way to measure spreading dynamics of extremely small volumes of heterogeneously complex fluids not possible through other means. Dr.Jonathan Felts is the principal investigator of the ANML research group in Mechanical Engineering Department of Texas A&M University.

  1. Unusual dynamic dewetting behavior of smooth perfluorinated hybrid films: potential advantages over conventional textured and liquid-infused perfluorinated surfaces.

    Science.gov (United States)

    Urata, Chihiro; Masheder, Benjamin; Cheng, Dalton F; Hozumi, Atsushi

    2013-10-08

    From a viewpoint of reducing the burden on the environment and human health, an alternative method for preparing liquid-repellent surfaces without relying on the long perfluorocarbons (C((X-1)/2)F(X), X ≥ 17) has been strongly demanded lately. In this study, we have successfully demonstrated that dynamic dewettability toward various probe liquids (polar and nonpolar liquids with high or low surface tension) can be tuned by not only controlling surface chemistries (surface energies) but also the physical (solid-like or liquid-like) nature of the surface. We prepared smooth and transparent organic-inorganic hybrid films exhibiting unusual dynamic dewetting behavior toward various probe liquids using a simple sol-gel reaction based on the co-hydrolysis and co-condensation of a mixture including a range of perfluoroalkylsilanes (FASX, C((X-1)/2)F(X)CH2CH2Si(OR)3, where X = 3, 9, 13, and 17) and tetramethoxysilane (Si(OCH3)4, TMOS). Dynamic contact angle (CA) and substrate tilt angle (TA) measurements confirmed that our FASX-hybrid films exhibited excellent dynamic dewetting properties and were mostly independent of the length of perfluoroalkyl (Rf) groups. For example, 10 μL droplets of ultralow surface tension liquids (e.g., diethyl ether (γ = 16.26 dyn/cm) and n-pentane (γ = 15.51 dyn/cm)) could move easily on our FAS9-, FAS13-, and FAS17-hybrid film surfaces at low substrate TAs (dynamic dewetting behavior appeared only when TMOS molecules were added to the precursor solutions; we assume this is due to co-condensed TMOS-derived silica species working as spacers between the neighboring Rf chains, enabling them to rotate freely and in doing so provide a surface with liquid-like properties. This led to the distinguished dynamic dewettability of our hybrid films, regardless of the small static CAs. Our FASX-hybrid films also displayed excellent chemical and physical durability against thermal stress (~250 °C), high-temperature (150 °C) oil vapor, and various

  2. Evaluation of laser fluorescence in monitoring non-cavitated caries lesion progression on smooth surfaces in vitro.

    Science.gov (United States)

    Rodrigues, J A; Sarti, C S; Assunção, C M; Arthur, R A; Lussi, A; Diniz, M B

    2017-07-02

    The aim of this study was to evaluate the performance of a pen-type laser fluorescence (LF) device (LFpen: DIAGNOdent pen) to detect and monitor the progression of caries-like lesions on smooth surfaces. Fifty-two bovine enamel blocks were submitted to three different demineralisation cycles for caries-like lesion induction using Streptococcus mutans, Lactobacillus casei and Actinomyces naeslundii. At baseline and after each cycle, the enamel blocks were analysed under Knoop surface micro-hardness (SMH) and an LFpen. One enamel block after each cycle was randomly chosen for Raman spectroscopy analysis. Cross-sectional micro-hardness (CSMH) was performed at different depths (20, 40, 60, 80 and 100 μm) in 26 enamel blocks after the second cycle and 26 enamel blocks after the third cycle. Average values of SMH (± standard deviation (SD)) were 319.3 (± 21.5), 80.5 (± 31.9), 39.8 (± 12.7), and 29.77 (± 10.34) at baseline and after the first, second and third cycles, respectively. Statistical significant difference was found among all periods (p  0.05). One sample of each cycle was characterised through Raman spectroscopy analysis. It can be concluded that LF was effective in detecting the first demineralisation on enamel; however, the method did not show any effect in monitoring lesion progression after three cycles of in vitro demineralisation.

  3. MMP20 Promotes a Smooth Enamel Surface, a Strong DEJ, and a Decussating Enamel Rod Pattern

    Science.gov (United States)

    Bartlett, John D.; Skobe, Ziedonis; Nanci, Antonio; Smith, Charles E.

    2012-01-01

    Mutations of the Matrix metalloproteinase-20 (MMP20, enamelysin) gene cause autosomal recessive amelogenesis imperfecta and Mmp20 ablated mice also have malformed dental enamel. Here we show that Mmp20 null mouse secretory stage ameloblasts maintained a columnar shape and were present as a single layer of cells. However, the null maturation stage ameloblasts covered extraneous nodules of ectopic calcified material formed at the enamel surface. Remarkably, nodule formation occurs in null mouse enamel when MMP20 is normally no longer expressed. The malformed enamel in Mmp20 null teeth was loosely attached to the dentin and the entire enamel layer tended to separate from the dentin indicative of a faulty DEJ. The enamel rod pattern was also altered in Mmp20 null mice. Each enamel rod is formed by a single ameloblast and is a mineralized record of the migration path of the ameloblast that formed it. The Mmp20 null mouse enamel rods were grossly malformed or were absent indicating that the ameloblasts do not migrate properly when backing away from the DEJ. Thus, MMP20 is required for ameloblast cell movement necessary to form the decussating enamel rod patterns, for the prevention of ectopic mineral formation, and to maintain a functional DEJ. PMID:22243247

  4. Co-culture of vascular endothelial cells and smooth muscle cells by hyaluronic acid micro-pattern on titanium surface

    Science.gov (United States)

    Li, Jingan; Li, Guicai; Zhang, Kun; Liao, Yuzhen; Yang, Ping; Maitz, Manfred F.; Huang, Nan

    2013-05-01

    Micro-patterning as an effective bio-modification technique is increasingly used in the development of biomaterials with superior mechanical and biological properties. However, as of now, little is known about the simultaneous regulation of endothelial cells (EC) and smooth muscle cells (SMC) by cardiovascular implants. In this study, a co-culture system of EC and SMC was built on titanium surface by the high molecular weight hyaluronic acid (HMW-HA) micro-pattern. Firstly, the micro-pattern sample with a geometry of 25 μm wide HMW-HA ridges, and 25 μm alkali-activated Ti grooves was prepared by microtransfer molding (μTM) for regulating SMC morphology. Secondly, hyaluronidase was used to decompose high molecular weight hyaluronic acid into low molecular weight hyaluronic acid which could promote EC adhesion. Finally, the morphology of the adherent EC was elongated by the SMC micro-pattern. The surface morphology of the patterned Ti was imaged by SEM. The existence of high molecular weight hyaluronic acid on the modified Ti surface was demonstrated by FTIR. The SMC micro-pattern and EC/SMC co-culture system were characterized by immunofluorescence microscopy. The nitric oxide release test and cell retention calculation were used to evaluate EC function on inhibiting hyperplasia and cell shedding, respectively. The results indicate that EC in EC/SMC co-culture system displayed a higher NO release and cell retention compared with EC cultured alone. It can be suggested that the EC/SMC co-culture system possessed superiority to EC cultured alone in inhibiting hyperplasia and cell shedding at least in a short time of 24 h.

  5. Effect of chamber pressure on spreading and splashing of liquid drops upon impact on a dry smooth stationary surface

    Science.gov (United States)

    Mishra, Neeraj Kumar; Zhang, Yan; Ratner, Albert

    2011-08-01

    Liquid drop impacts on a smooth surface were studied at elevated chamber pressures to characterize the effect of gas pressure on drop spreading and splashing. Five common liquids were tested at impact speeds between 1.0 and 3.5 m/s and pressure up to 12 bars. Based on experiments at atmospheric pressure, a modification to the "free spreading" model (Scheller and Bousfield in AIChE Paper 41(6):1357-1367, 1995) has been proposed that improves the prediction accuracy of maximum spread factors from an error of 15-5%. At high chamber pressures, drop spreading and maximum spread factor were found to be independent of pressure. The splash ratio (Xu et al. in Phys Rev Lett 94:184505, 2005) showed a non-constant behavior, and a power-law model was demonstrated to predict the increase in splash ratio with decreasing impact speed in the low impact speed regime. Also, drop shape was found to affect splash promotion or suppression for an asymmetry greater than 7-8% of the equivalent drop diameter. The observations of the current work could be especially useful for the study of formation of deposits and wall combustion in engine cylinders.

  6. Measuring the specific surface area of snow with X-ray tomography and gas adsorption: comparison and implications for surface smoothness

    Directory of Open Access Journals (Sweden)

    M. Kerbrat

    2008-03-01

    Full Text Available Chemical and physical processes, such as heterogeneous chemical reactions, light scattering, and metamorphism occur in the natural snowpack. To model these processes in the snowpack, the specific surface area (SSA is a key parameter. In this study, two methods, computed tomography and methane adsorption, which have intrinsically different effective resolutions – molecular and 30 μm, respectively – were used to determine the SSA of similar natural snow samples. Except for very fresh snow, the two methods give identical results, with an uncertainty of 3%. This implies that the surface of aged natural snow is smooth up to a scale of about 30 μm and that if smaller structures are present they do not contribute significantly to the overall SSA. It furthermore implies that for optical methods a voxel size of 10 μm is sufficient to capture all structural features of this type of snow; however, fresh precipitation appears to contain small features that cause an under-estimation of SSA with tomography at this resolution. The methane adsorption method is therefore superior to computed tomography for very fresh snow having high SSA. Nonetheless, in addition to SSA determination, tomography provides full geometric information about the ice matrix. It can also be advantageously used to investigate layered snow packs, as it allows measuring SSA in layers of less than 1 mm.

  7. Remaining Sites Verification Package for the 100-B-1 Surface Chemical and Solid Waste Dumping Area, Waste Site Reclassification Form 2006-003

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Carlson

    2006-04-24

    The 100-B-1 waste site was a dumping site that was divided into two areas. One area was used as a laydown area for construction materials, and the other area was used as a chemical dumping area. The 100-B-1 Surface Chemical and Solid Waste Dumping Area site meets the remedial action objectives specified in the Remaining Sites ROD. The results demonstrate that residual contaminant concentrations support future unrestricted land uses that can be represented by a rural-residential scenario. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  8. Randomised Clinical Trial on Resin Infiltration and Fluoride Varnish vs Fluoride Varnish Treatment Only of Smooth-surface Early Caries Lesions in Deciduous Teeth.

    Science.gov (United States)

    Turska-Szybka, Anna; Gozdowski, Dariusz; Mierzwińska-Nastalska, Elżbieta; Olczak-Kowalczyk, Dorota

    2016-01-01

    To clinically evaluate the effectiveness of resin infiltration in conjunction with fluoride varnish treatment vs fluoride varnish treatment alone on facial smooth-surface caries lesions in deciduous teeth. This randomised clinical trial was conducted in 419 children aged 18-71 months with at least two active smooth-surface caries lesions in deciduous teeth (ICDAS II score 2). Eighty-one participants met the inclusion criteria and were allocated to one of the two treatment groups: resin infiltration and fluoride varnish (RI+FV) (n = 41) and fluoride varnish only (FV) (n = 40). The prevalence of treated white spot lesions (WSL) was scored. Fluoride varnish was applied in both groups every 3 months for a year. The mean baseline age of children was 3.8 ± 1.3 years. The effectiveness of resin infiltration measured as the percentage of children who did not present any progression of the treated lesions amounted to 43.1%. After one year, 92.1% of the infiltrated lesions (RI+FV) and 70.6% of the FV lesions had not progressed (p fluoride varnish treatment of early facial smooth-surface caries lesions in deciduous teeth is superior to fluoride varnish treatment alone for reducing lesion progression.

  9. Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries.

    Science.gov (United States)

    Gliesche, Daniel G; Hussner, Janine; Witzigmann, Dominik; Porta, Fabiola; Glatter, Timo; Schmidt, Alexander; Huwyler, Jörg; Meyer Zu Schwabedissen, Henriette E

    2016-07-01

    Cardiovascular diseases are the leading causes of death in industrialized countries. Atherosclerotic coronary arteries are commonly treated with percutaneous transluminal coronary intervention followed by stent deployment. This treatment has significantly improved the clinical outcome. However, triggered vascular smooth muscle cell (SMC) proliferation leads to in-stent restenosis in bare metal stents. In addition, stent thrombosis is a severe side effect of drug eluting stents due to inhibition of endothelialization. The aim of this study was to develop and test a stent surface polymer, where cytotoxic drugs are covalently conjugated to the surface and released by proteases selectively secreted by proliferating smooth muscle cells. Resting and proliferating human coronary artery smooth muscle cells (HCASMC) and endothelial cells (HCAEC) were screened to identify an enzyme exclusively released by proliferating HCASMC. Expression analyses and enzyme activity assays verified selective and exclusive activity of the matrix metalloproteinase-9 (MMP-9) in proliferating HCASMC. The principle of drug release exclusively triggered by proliferating HCASMC was tested using the biodegradable stent surface polymer poly-l-lactic acid (PLLA) and the MMP-9 cleavable peptide linkers named SRL and AVR. The specific peptide cleavage by MMP-9 was verified by attachment of the model compound fluorescein. Fluorescein release was observed in the presence of MMP-9 secreting HCASMC but not of proliferating HCAEC. Our findings suggest that cytotoxic drug conjugated polymers can be designed to selectively release the attached compound triggered by MMP-9 secreting smooth muscle cells. This novel concept may be beneficial for stent endothelialization thereby reducing the risk of restenosis and thrombosis.

  10. 肋条状仿生非光滑表面铸造成型方法%Casting method of rib-like bionic non-smooth surface

    Institute of Scientific and Technical Information of China (English)

    田丽梅; 卜兆国; 陈庆海; 李文渊; 李新红

    2011-01-01

    It is already confirmed that the riblets on the shark skin have the function of drag reduction, however, it is very difficult to achieve on surfaces of complex casting parts for such bionic non-smooth surface, which seriously restricted its engineering applications. This paper took non-smooth structure of triangle section as a example, and took the centrifugal pump impeller surface of rib-like on the type of 200QJ50-26 as a carrier and discussed a casting forming principle and process of bionic non-smooth surface. First, according to designing request, rib-like non-smooth structures were sculptured using knife and ruler on the hard rubber pad. Second, heat-resisting lacquer was spread evenly on the two side of the riblet and made them natural drying. Third, utilizing the characteristic of rubber, the rib-shape rubber was adhered to the sand moulding surface of impeller according to the shape of it. Finally, cast molding. Selecting heating-resisting lacquer and painting it play a vital role in casting process .The sharp edges of the triangle groove that meet the design requirements can be formed by using a casting shaping method of bionic non-smooth surface, and non-smooth surface can be formed in the full port of impeller internal, and this method adapts to the processing of the non-smooth surface of complex parts.%鲨鱼皮肤表面的肋条状(riblet)非光滑结构具有减阻功能,已经被证实,但这种仿生非光滑表面在复杂铸件表面上难以实现,严重制约了它在工程上的应用.该文以横截面为三角形的非光滑结构为例,以200QJ50-26型离心式水泵叶轮表面为载体,对仿生非光滑表面一次铸造成型原理及工艺进行探讨.该工艺采用原料→切割成型→涂高温漆→粘贴→风干→修剪→成型→铸造的流程,尤其是高温漆的选择及涂抹对该成型工艺具有至关重要的作用.采用仿生非光滑表面一次铸造成型法能形成设计要求的三角形沟槽的尖角,而

  11. Buffered Electropolishing – A New Way for Achieving Extremely Smooth Surface Finish on Nb SRF Cavities to be Used in Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Hui Tian, Charles Reece, Michael Kelley

    2009-05-01

    Future accelerators require unprecedented cavity performance, which is strongly influenced by interior surface nano-smoothness. Electropolishing (EP) is the technique of choice to be developed for high-field superconducting radio frequency (SRF) cavities. Electrochemical impedance spectroscopy (EIS) and related techniques point to the electropolishing mechanism of Nb in a sulphuric and hydrofluoric acid electrolyte controlled by a compact surface salt film under F- diffusion-limited mass transport control. These and other findings are guiding a systematic characterization to form the basis for cavities process optimization.

  12. Smooth magnetogenesis

    CERN Document Server

    Campanelli, L

    2016-01-01

    In the Ratra scenario of inflationary magnetogenesis, the kinematic coupling between the photon and the inflaton undergoes a nonanalytical jump at the end of inflation. Using smooth interpolating analytical forms of the coupling function, we show that such unphysical jump does not invalidate the main prediction of the model, which still represents a viable mechanism for explaining cosmic magnetization. Nevertheless, there is a spurious result associated with the nonanaliticity of the coupling, to wit, the prediction that the spectrum of created photons has a power-law decay in the ultraviolet regime. This issue is discussed using both semiclassical approximation and smooth coupling functions.

  13. 修正表面张力算法的SPH方法及其实现%Smoothed Particle Hydrodynamics Method with Modified Surface Tension and Its Implementation

    Institute of Scientific and Technical Information of China (English)

    强洪夫; 陈福振; 高巍然

    2011-01-01

    Modified equations for surface tension are derived by modifying normal and curvature with corrected smoothed particle method (CSPM). It is based on smoothed particle hydrodynamics (SPH) method with surface tension proposed by Morris. Both Morris and our method are tested via a semicircular problem. Factors that affect accuracy are investigated including surface definition, normal and curvature calculation. Smoothed length in curvature calculation is also confirmed reasonable. Furthermore, formation of a liquid drop with initial square shape under surface tension is simulated. Compared with Morris method and grid-based volume of fluid method,it is proved that the accuracy of our method is higher and particle distribution is more homogeneous. Finally, coalescence process of two oil drops in water under surface tension is simulated.%在Morris提出的表面张力SPH方法基础上,通过引入CSPM方法对边界法向的计算和曲率的计算进行修正,得到表面张力修正方程组;通过半圆形算例测试方法和Morris方法在边界定位、法向计算和曲率计算等影响表面张力关键因素的求解精度,研究曲率计算中应采用的光滑长度值.模拟初始方形液滴在表面张力作用下的自然变化过程,并与Morris方法及VOF有限体积法进行对比,表明方法精度较高,稳定性较好.最后,模拟水溶液中两个油滴的互溶过程.

  14. Smoothed Invariants

    CERN Document Server

    Dye, H A

    2011-01-01

    We construct two knot invariants. The first knot invariant is a sum constructed using linking numbers. The second is an invariant of flat knots and is a formal sum of flat knots obtained by smoothing pairs of crossings. This invariant can be used in conjunction with other flat invariants, forming a family of invariants. Both invariants are constructed using the parity of a crossing.

  15. Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

    Science.gov (United States)

    Fujikura, Hajime; Konno, Taichiro; Yoshida, Takehiro; Horikiri, Fumimasa

    2017-08-01

    Thick (20-30 µm) layers of highly pure GaN with device-quality smooth as-grown surfaces were prepared on freestanding GaN substrates by using our advanced hydride-vapor-phase epitaxy (HVPE) system. Removal of quartz parts from the HVPE system markedly reduced concentrations of residual impurities to below the limits of detection by secondary-ion mass spectrometry. Appropriate gas-flow management in the HVPE system realized device-quality, smooth, as-grown surfaces with an excellent uniformity of thickness. The undoped GaN layer showed insulating properties. By Si doping, the electron concentration could be controlled over a wide range, down to 2 × 1014 cm-3, with a maximum mobility of 1150 cm2·V-1·s-1. The concentration of residual deep levels in lightly Si-doped layers was in the 1014 cm-3 range or less throughout the entire 2-in. wafer surface. These achievements clearly demonstrate the potential of HVPE as a tool for epitaxial growth of power-device structures.

  16. A Method for Decreasing the Amount of the Drug Remaining on the Surfaces of the Mortar and Pestle after Grinding Small Amount of Tablets.

    Science.gov (United States)

    Kawakami, Miki; Kitada, Rika; Kurita, Takuro; Tokumura, Tadakazu

    2017-01-01

     The aim of the present study was to develop a method for grinding tablets with a mortar and pestle while reducing drug loss because grinding tablets is known to be associated with reductions in tablet weight and loss of the active drug. Seven kinds of tablets were subjected to grinding. The proportion (%) of the amount of the active drug in the powder remaining on the surfaces of the mortar and pestle relative to the total amount of the drug recovered (the recovery percent) was calculated. The recovery percent of the 7 kinds of tablets ranged from 17.2-35.9%, and the tablets' recovery percent decreased as the tablet weight increased. When the grinding was performed with 1 g of lactose monohydrate or 1 g of D-mannitol moistened with water, the recovery percent of the tablets decreased to 2.6-9.9% and 3.8-9.9%, respectively. The effects of the weight of lactose monohydrate on the recovery percent of Allegra(®) 60 mg tablets were examined. It was found that at least 0.6 g of lactose monohydrate was required to have a sufficient effect on drug recovery. Therefore, additives that have stronger effects at lower amounts were sought. As a result, calcium monohydrogen phosphate was found to have the strongest effect on drug recovery. The addition of 0.4 g calcium monohydrogen phosphate resulted in the recovery percent of 5.1%, which was significantly lower than that of 15.0% observed after the addition of 0.4 g lactose monohydrate, and lower than the 6.8% of 1 g lactose monohydrate.

  17. Gallic acid tailoring surface functionalities of plasma-polymerized allylamine-coated 316L SS to selectively direct vascular endothelial and smooth muscle cell fate for enhanced endothelialization.

    Science.gov (United States)

    Yang, Zhilu; Xiong, Kaiqin; Qi, Pengkai; Yang, Ying; Tu, Qiufen; Wang, Jin; Huang, Nan

    2014-02-26

    The creation of a platform for enhanced vascular endothelia cell (VEC) growth while suppressing vascular smooth muscle cell (VSMC) proliferation offers possibility for advanced coatings of vascular stents. Gallic acid (GA), a chemically unique phenolic acid with important biological functions, presents benefits to the cardiovascular disease therapy because of its superior antioxidant effect and a selectivity to support the growth of ECs more than SMCs. In this study, GA was explored to tailor such a multifunctional stent surface combined with plasma polymerization technique. On the basis of the chemical coupling reaction, GA was bound to an amine-group-rich plasma-polymerized allylamine (PPAam) coating. The GA-functionalized PPAam (GA-PPAam) surface created a favorable microenvironment to obtain high ECs and SMCs selectivity. The GA-PPAam coating showed remarkable enhancement in the adhesion, viability, proliferation, migration, and release of nitric oxide (NO) of human umbilical vein endothelial cells (HUVECs). The GA-PPAam coating also resulted in remarkable inhibition effect on human umbilical artery smooth muscle cell (HUASMC) adhesion and proliferation. These striking findings may provide a guide for designing the new generation of multifunctional vascular devices.

  18. Reconstruction of Cell Surface Densities of Ion Pumps, Exchangers, and Channels from mRNA Expression, Conductance Kinetics, Whole-Cell Calcium, and Current-Clamp Voltage Recordings, with an Application to Human Uterine Smooth Muscle Cells.

    Directory of Open Access Journals (Sweden)

    Jolene Atia

    2016-04-01

    Full Text Available Uterine smooth muscle cells remain quiescent throughout most of gestation, only generating spontaneous action potentials immediately prior to, and during, labor. This study presents a method that combines transcriptomics with biophysical recordings to characterise the conductance repertoire of these cells, the 'conductance repertoire' being the total complement of ion channels and transporters expressed by an electrically active cell. Transcriptomic analysis provides a set of potential electrogenic entities, of which the conductance repertoire is a subset. Each entity within the conductance repertoire was modeled independently and its gating parameter values were fixed using the available biophysical data. The only remaining free parameters were the surface densities for each entity. We characterise the space of combinations of surface densities (density vectors consistent with experimentally observed membrane potential and calcium waveforms. This yields insights on the functional redundancy of the system as well as its behavioral versatility. Our approach couples high-throughput transcriptomic data with physiological behaviors in health and disease, and provides a formal method to link genotype to phenotype in excitable systems. We accurately predict current densities and chart functional redundancy. For example, we find that to evoke the observed voltage waveform, the BK channel is functionally redundant whereas hERG is essential. Furthermore, our analysis suggests that activation of calcium-activated chloride conductances by intracellular calcium release is the key factor underlying spontaneous depolarisations.

  19. Reconstruction of Cell Surface Densities of Ion Pumps, Exchangers, and Channels from mRNA Expression, Conductance Kinetics, Whole-Cell Calcium, and Current-Clamp Voltage Recordings, with an Application to Human Uterine Smooth Muscle Cells.

    Science.gov (United States)

    Atia, Jolene; McCloskey, Conor; Shmygol, Anatoly S; Rand, David A; van den Berg, Hugo A; Blanks, Andrew M

    2016-04-01

    Uterine smooth muscle cells remain quiescent throughout most of gestation, only generating spontaneous action potentials immediately prior to, and during, labor. This study presents a method that combines transcriptomics with biophysical recordings to characterise the conductance repertoire of these cells, the 'conductance repertoire' being the total complement of ion channels and transporters expressed by an electrically active cell. Transcriptomic analysis provides a set of potential electrogenic entities, of which the conductance repertoire is a subset. Each entity within the conductance repertoire was modeled independently and its gating parameter values were fixed using the available biophysical data. The only remaining free parameters were the surface densities for each entity. We characterise the space of combinations of surface densities (density vectors) consistent with experimentally observed membrane potential and calcium waveforms. This yields insights on the functional redundancy of the system as well as its behavioral versatility. Our approach couples high-throughput transcriptomic data with physiological behaviors in health and disease, and provides a formal method to link genotype to phenotype in excitable systems. We accurately predict current densities and chart functional redundancy. For example, we find that to evoke the observed voltage waveform, the BK channel is functionally redundant whereas hERG is essential. Furthermore, our analysis suggests that activation of calcium-activated chloride conductances by intracellular calcium release is the key factor underlying spontaneous depolarisations.

  20. Functional Spline Curves and Surfaces with Different Degrees of Smoothness%异度隐函数样条曲线曲面

    Institute of Scientific and Technical Information of China (English)

    朱春钢; 李彩云; 王仁宏

    2009-01-01

    Implicit curves and surfaces are extensively used in interpolation, approximation and blending. By adding auxiliary curves and surfaces, the functional spline curves and surfaces with different degrees of smoothness are presented. In addition, convexity, regularity and convexity are also discussed. The examples show that the functional spline curves and surfaces provide the lower degree, simple, and flexible interpolation and blending means of curves and surfaces.%隐式曲线曲面被广泛应用于曲线曲面插值、逼近与拼接. 通过添加辅助曲线曲面,提出异度隐函数样条曲线曲面方法,并对其插值性、凸性与正则性进行分析. 具体实例表明,异度隐函数样条提供了次数低、构造简单、灵活性好的曲线曲面插值与拼接方法.

  1. Micro- and nanostructured Al{sub 2}O{sub 3} surfaces for controlled vascular endothelial and smooth muscle cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Aktas, Cenk, E-mail: cenk.aktas@inm-gmbh.de [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Doerrschuck, Eva; Schuh, Cathrin [Clinic of Paediatric Cardiology, Saarland University, Building 9, 66424 Homburg (Germany); Miro, Marina Martinez; Lee, Juseok [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Puetz, Norbert; Wennemuth, Gunther [Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424 Homburg (Germany); Metzger, Wolfgang; Oberringer, Martin [Department of Trauma-, Hand- and Reconstructive Surgery, Saarland University, Building 57, 66424 Homburg (Germany); Veith, Michael [INM - Leibniz Institute for New Materials, CVD/Biosurfaces Division, 66123 Saarbruecken (Germany); Department of Inorganic Chemistry, University of Saarland, Building C 4 1, 66123 Saarbruecken (Germany); Abdul-Khaliq, Hashim [Clinic of Paediatric Cardiology, Saarland University, Building 9, 66424 Homburg (Germany)

    2012-07-01

    The effect of the micro- and nanotopography on vascular cell-surface interaction is investigated using nano- and microstructured Al{sub 2}O{sub 3} as model substrate. Two different nanostructured Al{sub 2}O{sub 3} surfaces composed of low density (LD) and high density (HD) nanowires (NWs) were synthesized by chemical vapour deposition (CVD) and commercially available microstructured Al{sub 2}O{sub 3} plates were used for comparison. A clear diverging response of human umbilical vein endothelial cells (HUVEC) and human umbilical vein smooth muscle cells (HUVSMC) was observed on these nano- and microstructured surfaces. LD Al{sub 2}O{sub 3} NWs seem to enhance the proliferation of HUVECs selectively. This selective control of the cell-surface interaction by topography may represent a key issue for the future stent material design. - Highlights: Black-Right-Pointing-Pointer Nanostructured alumina surfaces triggers selective adhesion and proliferation of endothelial cells. Black-Right-Pointing-Pointer Catalyst free synthesis of nanowires. Black-Right-Pointing-Pointer Topography induces selective cell response.

  2. Clumping and the Interpretation of kpc-Scale Maps of the Interstellar Medium: Smooth HI and Clumpy, Variable H2 Surface Density

    CERN Document Server

    Leroy, Adam K; Schruba, Andreas; Bolatto, Alberto; Hughes, Annie; Pety, Jerome; Sandstrom, Karin; Schinnerer, Eva; Walter, Fabian

    2013-01-01

    Many recent models consider the structure of individual interstellar medium (ISM) clouds as a way to explain observations of large parts of galaxies. To compare such models to observations, one must understand how to translate between surface densities observed averaging over large (~kpc) scales and surface densities on the scale of individual clouds (~pc scale), which are treated by models. We define a "clumping factor" that captures this translation as the ratio of the mass-weighted surface density, which is often the quantity of physical interest, to the area-weighted surface density, which is observed. We use high spatial resolution (sub-kpc) maps of CO and HI emission from nearby galaxies to measure the clumping factor of both atomic and molecular gas. The molecular and atomic ISM exhibit dramatically different degrees of clumping. As a result, the ratio H2/HI measured at ~kpc resolution cannot be trivially interpreted as a cloud-scale ratio of surface densities. HI emission appears very smooth, with a c...

  3. Surface-gradient cross-linked polyethylene acetabular cups: oxidation resistance and wear against smooth and rough femoral balls.

    Science.gov (United States)

    Shen, Fu-Wen; McKellop, Harry

    2005-01-01

    Two methods were developed and evaluated for cross-linking the bearing surface of a polyethylene acetabular cup to a limited depth, in order to improve its resistance to wear without degrading the mechanical properties of the bulk of the component. In the first method, low-energy electron beams were used to cross-link only the bearing surface of the cups to a maximum depth of about 2 mm. The cups then were annealed at 100 degrees C in vacuum for 3 or 6 days to reduce the residual free radicals, and the resultant resistance to oxidation was compared by artificially aging the cups at 80 degrees C in air. Chemically cross-linked surface layers were produced by coating the bearing surfaces of the cups with a thin layer of polyethylene powder mixed with 1% weight peroxide, and compressing them at 6.9 MPa (1000 psi) and 170 degrees C. This resulted in a cross-linked surface layer that extended about 3 mm deep, with a gradual transition to conventional (noncross-linked) polyethylene in the bulk of the implant. In hip simulator wear tests with highly polished (implant quality) femoral balls, both types of surface cross-linking were found to improve markedly the wear resistance of the acetabular cups. In tests with roughened femoral balls, the wear rates were much higher and were comparable to those obtained with similarly roughened balls against noncross-linked polyethylene cups in a previous study, indicating that the full benefit of cross-linking may not be realized under conditions of severe third-body abrasion. Nevertheless, these results show a promising approach for optimizing the wear resistance and the bulk mechanical properties of polyethylene components in total joint arthroplasty.

  4. Effect of Increasing Doses of γ-Radiation on Bone Marrow Stromal Cells Grown on Smooth and Rough Titanium Surfaces

    Directory of Open Access Journals (Sweden)

    Bo Huang

    2015-01-01

    Full Text Available Radiation therapy for oral and maxillofacial tumors could damage bone marrow stromal cells (BMSCs in jaw, which caused dental implant failure. However, how radiation affects BMSCs on SLA (sandblasted with large-grits, acid-etched surfaces is still unknown. The aim of this study was to investigate effect of different dose of γ-radiation on BMSCs on SLA and PT (polished titanium surfaces. Rat BMSCs were radiated with 2, 4, and 8 Gy γ-radiation and then seeded on both surfaces. Cell adhesion, spreading, and proliferation were tested. The osteogenesis and the adipogenesis ability were examined by Alizarin-Red and Oil-Red staining, respectively. Real-time PCR was performed to detect osteogenic (osteocalcin, OCN; runt-related transcription factor 2, Runx2 and adipogenic (peroxisome proliferator-activated receptor gamma, PPARγ gene expression at days 7 and 14 postirradiation. Results showed that γ-radiation reduced cell proliferation, adhesion, spreading, and osteogenic differentiation. 2 Gy radiation promoted adipogenic differentiation, but it was significantly decreased when dosage reached 4 Gy. In conclusion, results suggest that γ-radiation influenced BMSCs behaviors in a dosage-dependent manner except adipogenic differentiation, low dose promoted it, and high dose inhibited it. This effect was influenced by surface characteristics, which may explain the different failure rate of various implants in patients after radiation.

  5. CLUMPING AND THE INTERPRETATION OF kpc-SCALE MAPS OF THE INTERSTELLAR MEDIUM: SMOOTH H I AND CLUMPY, VARIABLE H{sub 2} SURFACE DENSITY

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, Adam K. [National Radio Astronomy Observtory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Lee, Cheoljong [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Schruba, Andreas [California Institute for Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States); Bolatto, Alberto [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Hughes, Annie; Sandstrom, Karin; Schinnerer, Eva; Walter, Fabian [Max Planck Institute fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Pety, Jerome [Institut de Radioastronomie Millimetrique, 300 Rue de la Piscine, F-38406 Saint Martin d' Heres (France)

    2013-05-20

    Many recent models consider the structure of individual interstellar medium (ISM) clouds as a way to explain observations of large parts of galaxies. To compare such models to observations, one must understand how to translate between surface densities observed averaging over large ({approx}kpc) scales and surface densities on the scale of individual clouds ({approx}pc scale), which are treated by models. We define a ''clumping factor'' that captures this translation as the ratio of the mass-weighted surface density, which is often the quantity of physical interest, to the area-weighted surface density, which is observed. We use high spatial resolution (sub-kpc) maps of CO and H I emission from nearby galaxies to measure the clumping factor of both atomic and molecular gas. The molecular and atomic ISM exhibit dramatically different degrees of clumping. As a result, the ratio H{sub 2}/H I measured at {approx}kpc resolution cannot be trivially interpreted as a cloud-scale ratio of surface densities. H I emission appears very smooth, with a clumping factor of only {approx}1.3. Based on the scarce and heterogeneous high-resolution data available, CO emission is far more clumped with a widely variable clumping factor, median {approx}7 for our heterogeneous data. Our measurements do not provide evidence for a universal mass-weighted surface density of molecular gas, but also cannot conclusively rule out such a scenario. We suggest that a more sophisticated treatment of molecular ISM structure, one informed by high spatial resolution CO maps, is needed to link cloud-scale models to kpc-scale observations of galaxies.

  6. Validation of a nylon-flocked-swab protocol for efficient recovery of bacterial spores from smooth and rough surfaces.

    Science.gov (United States)

    Probst, Alexander; Facius, Rainer; Wirth, Reinhard; Moissl-Eichinger, Christine

    2010-08-01

    In order to meet planetary-protection requirements, culturable bacterial spore loads are measured representatively for the total microbial contamination of spacecraft. However, the National Aeronautics and Space Administration's (NASA's) cotton swab protocols for spore load determination have not changed for decades. To determine whether a more efficient alternative was available, a novel swab was evaluated for recovery of different Bacillus atrophaeus spore concentrations on stainless steel and other surfaces. Two protocols for the nylon-flocked swab (NFS) were validated and compared to the present NASA standard protocol. The results indicate that the novel swab protocols recover 3- to 4-fold more (45.4% and 49.0% recovery efficiency) B. atrophaeus spores than the NASA standard method (13.2%). Moreover, the nylon-flocked-swab protocols were superior in recovery efficiency for spores of seven different Bacillus species, including Bacillus anthracis Sterne (recovery efficiency, 20%). The recovery efficiencies for B. atrophaeus spores from different surfaces showed a variation from 5.9 to 62.0%, depending on the roughness of the surface analyzed. Direct inoculation of the swab resulted in a recovery rate of about 80%, consistent with the results of scanning electron micrographs that allowed detailed comparisons of the two swab types. The results of this investigation will significantly contribute to the cleanliness control of future life detection missions and will provide significant improvement in detection of B. anthracis contamination for law enforcement and security efforts.

  7. Statistical analysis of turbulent super-streamwise vortices based on observations of streaky structures near the free surface in the smooth open channel flow

    Science.gov (United States)

    Zhong, Qiang; Chen, Qigang; Wang, Hao; Li, Danxun; Wang, Xingkui

    2016-05-01

    Long streamwise-elongated high- and low-speed streaks are repeatedly observed near the free surface in open channel flows in natural rivers and lab experiments. Super-streamwise vortex model has been proposed to explain this widespread phenomenon for quite some time. However, statistical evidence of the existence of the super-streamwise vortices as one type of coherent structures is still insufficient. Correlation and proper orthogonal decomposition (POD) analysis based on PIV experimental data in the streamwise-spanwise plane near the free surface in a smooth open channel flow are employed to investigate this topic. Correlation analysis revealed that the streaky structures appear frequently near the free surface and their occurrence probability at any spanwise position is equal. The spanwise velocity fluctuation usually flows from low-speed streaks toward high-speed streaks. The average spanwise width and spacing between neighboring low (or high) speed streaks are approximately h and 2h respectively. POD analysis reveals that there are streaks with different spanwise width in the instantaneous flow fields. Typical streamwise rotational movement can be sketched out directly based on the results from statistical analyses. Point-by-point analysis indicates that this pattern is consistent everywhere in the measurement window and is without any inhomogeneity in the spanwise direction, which reveals the essential difference between coherent structures and secondary flow cells. The pattern found by statistical analysis is consistent with the notion that the super-streamwise vortices exist universally as one type of coherent structure in open channel flows.

  8. Remaining Sites Verification Package for the 100-B-23, 100-B/C Area Surface Debris, Waste Site, Waste Site Reclassification Form 2008-027

    Energy Technology Data Exchange (ETDEWEB)

    J. M. Capron

    2008-06-16

    The 100-B-23, 100-B/C Surface Debris, waste consisted of multiple locations of surface debris and chemical stains that were identified during an Orphan Site Evaluation of the 100-B/C Area. Evaluation of the collected information for the surface debris features yielded four generic waste groupings: asbestos-containing material, lead debris, oil and oil filters, and treated wood. Focused verification sampling was performed concurrently with remediation. Site remediation was accomplished by selective removal of the suspect hazardous items and potentially impacted soils. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  9. Smoothing function suitable for estimation of amplification factor of the surface ground from microtremor and its application; Joji bido no suihei/joge supekutoru hi wo mochiiru zofuku bairitsu no suitei ni tekishita heikatsuka to sono tekiyorei

    Energy Technology Data Exchange (ETDEWEB)

    Konno, K. [Shibaura Institute of Technology, Tokyo (Japan); Omachi, T. [Tokyo Institute of Technology, Tokyo (Japan)

    1995-10-21

    When properly smoothed spectral ratios between horizontal and vertical components of Rayleigh waves are well correlated with amplification factors of SH waves in the surface ground. This is demonstrated by a series of numerical simulations for various soft surface layers. For this reason, a smoothing function is newly proposed and applied to estimation of the amplification factor from microtremor data observed in Tokyo area. An amplification factor map resulting from the estimation shows a good resemblance with an existing map to a satisfactory level of accuracy. 20 refs., 25 figs., 2 tabs.

  10. Surface electromyography studies in standing position confirm that ankle strategy remains disturbed even following successful treatment of patients with a history of sciatica

    OpenAIRE

    Huber, Juliusz; Lisiński, Przemysław; Ciesielska, Jagoda; Kulczyk, Aleksandra; Lipiec, Joanna; Bandosz, Agata

    2016-01-01

    [Purpose] It is hypothesized that ankle strategy can be changed in patients with a history of sciatica. The aim of this study was to detect residual disturbances following successful treatment. [Subjects and Methods] In patients with a history of sciatica (N=11) and pseudo-sciatica (N=9), differences in muscle activity were recorded with bilateral surface polyelectromyography and stability measurements (center of foot pressure sway and center of spectrum) in normal standing and tandem positio...

  11. Exotic smoothness and quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Asselmeyer-Maluga, T, E-mail: torsten.asselmeyer-maluga@dlr.d [German Aerospace Center, Berlin, Germany and Loyola University, New Orleans, LA (United States)

    2010-08-21

    Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (2009 arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the 'smoothness structure' part of the path integral in quantum gravity assuming that the 'sum over geometries' is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery in the manner of Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, for the construction of an exotic 4-manifold using the knot 5{sub 2} and the Whitehead link Wh. By using Mostow rigidity, we obtain a topological contribution to the expectation value of the volume. Furthermore, we obtain a justification of area quantization.

  12. Exotic Smoothness and Quantum Gravity

    CERN Document Server

    Asselmeyer-Maluga, Torsten

    2010-01-01

    Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the "smoothness structure" part of the path integral in quantum gravity assuming that the "sum over geometries" is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery a la Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, f...

  13. Surface fuels quantification in forest plantations and remaining of atlantic forest in the “Brejo” region in Paraíba State, Brazil”

    Directory of Open Access Journals (Sweden)

    Patrícia Carneiro Souto

    2009-12-01

    Full Text Available Studies on the accumulation of combustible material in native forests and plantations are mainly important tool for estimating the risk of forest fires. This study aimed to determine the amount of combustible material in forest stands and in the remaining rain forest located in the municipality of Areia, in Brejo of Paraiba. The collection of combustible material was carried out in plots of 1m ², randomly selected areas. The fuel accumulated in the different areas were classified according to the physiological state of alive and dead. The largest amount of combustible material was obtained in the area of the Atlantic with 19.47 Mg ha-1. The amount of combustible material alive did not differ between the studied areas.

  14. Relative Smooth Topological Spaces

    Directory of Open Access Journals (Sweden)

    B. Ghazanfari

    2009-01-01

    Full Text Available In 1992, Ramadan introduced the concept of a smooth topological space and relativeness between smooth topological space and fuzzy topological space in Chang's (1968 view points. In this paper we give a new definition of smooth topological space. This definition can be considered as a generalization of the smooth topological space which was given by Ramadan. Some general properties such as relative smooth continuity and relative smooth compactness are studied.

  15. Effect of Fuchunsan I on healing of remaining wound surface in burn%复春散Ⅰ号对烧伤残余创面愈合的影响

    Institute of Scientific and Technical Information of China (English)

    黄灿全

    2003-01-01

    @@ BACKGROUND: Remaining wound surface in late stage isoften found in patients with big area of deep burn and infection iscomplicated in most cases. There are many causes for remainingwound surface, but local repeated infection is one of the importantreasons. Once infection occurred at wound surface, growth of ep-ithelial cells will be influenced seriously because of large amount ofbacteria and products of metabolism and effect of skin graft isn' tsatisfying. So, an effective method must be adopted to replace skingraft and promote healing of wound surface. Fuchunsan I effectivelyresolved this problem.

  16. Peripheral snap-fit locking mechanisms and smooth surface finish of tibial trays reduce backside wear in fixed-bearing total knee arthroplasty.

    Science.gov (United States)

    Łapaj, Łukasz; Mróz, Adrian; Kokoszka, Paweł; Markuszewski, Jacek; Wendland, Justyna; Helak-Łapaj, Celina; Kruczyński, Jacek

    2017-02-01

    Background and purpose - Severe backside wear, observed in older generations of total knee replacements (TKRs), led to redesign of locking mechanisms to reduce micromotions between tibial tray and inlay. Since little is known about whether this effectively reduces backside wear in modern designs, we examined backside damage in retrievals of various contemporary fixed-bearing TKRs. Patients and methods - A consecutive series of 102 inlays with a peripheral (Stryker Triathlon, Stryker Scorpio, DePuy PFC Sigma, Aesculap Search Evolution) or dovetail locking mechanism (Zimmer NexGen, Smith and Nephew Genesis II) was examined. Articular and backside surface damage was evaluated using the semiquantitative Hood scale. Inlays were examined using scanning electron microscopy (SEM) to determine backside wear mechanisms. Results - Mean Hood scores for articular (A) and backside (B) surfaces were similar in most implants-Triathlon (A: 46, B: 22), Genesis II (A: 55, B: 24), Scorpio (A: 57, B: 24), PFC (A: 52, B: 20); Search (A: 56, B: 24)-except the NexGen knee (A: 57, B: 60), which had statistically significantly higher backside wear scores. SEM studies showed backside damage caused by abrasion related to micromotion in designs with dovetail locking mechanisms, especially in the unpolished NexGen trays. In implants with peripheral liner locking mechanism, there were no signs of micromotion or abrasion. Instead, "tray transfer" of polyethylene and flattening of machining was observed. Interpretation - Although this retrieval study may not represent well-functioning TKRs, we found that a smooth surface finish and a peripheral locking mechanism reduce backside wear in vivo, but further studies are required to determine whether this actually leads to reduced osteolysis and lower failure rates.

  17. Peripheral snap-fit locking mechanisms and smooth surface finish of tibial trays reduce backside wear in fixed-bearing total knee arthroplasty

    Science.gov (United States)

    Łapaj, Łukasz; Mróz, Adrian; Kokoszka, Paweł; Markuszewski, Jacek; Wendland, Justyna; Helak-Łapaj, Celina; Kruczyński, Jacek

    2017-01-01

    Background and purpose — Severe backside wear, observed in older generations of total knee replacements (TKRs), led to redesign of locking mechanisms to reduce micromotions between tibial tray and inlay. Since little is known about whether this effectively reduces backside wear in modern designs, we examined backside damage in retrievals of various contemporary fixed-bearing TKRs. Patients and methods — A consecutive series of 102 inlays with a peripheral (Stryker Triathlon, Stryker Scorpio, DePuy PFC Sigma, Aesculap Search Evolution) or dovetail locking mechanism (Zimmer NexGen, Smith and Nephew Genesis II) was examined. Articular and backside surface damage was evaluated using the semiquantitative Hood scale. Inlays were examined using scanning electron microscopy (SEM) to determine backside wear mechanisms. Results — Mean Hood scores for articular (A) and backside (B) surfaces were similar in most implants—Triathlon (A: 46, B: 22), Genesis II (A: 55, B: 24), Scorpio (A: 57, B: 24), PFC (A: 52, B: 20); Search (A: 56, B: 24)—except the NexGen knee (A: 57, B: 60), which had statistically significantly higher backside wear scores. SEM studies showed backside damage caused by abrasion related to micromotion in designs with dovetail locking mechanisms, especially in the unpolished NexGen trays. In implants with peripheral liner locking mechanism, there were no signs of micromotion or abrasion. Instead, “tray transfer” of polyethylene and flattening of machining was observed. Interpretation — Although this retrieval study may not represent well-functioning TKRs, we found that a smooth surface finish and a peripheral locking mechanism reduce backside wear in vivo, but further studies are required to determine whether this actually leads to reduced osteolysis and lower failure rates. PMID:27781667

  18. Fish remains and humankind

    Directory of Open Access Journals (Sweden)

    Andrew K G Jones

    1997-08-01

    Full Text Available The four papers in this issue represent a trawl of the reports presented to the Fourth meeting of the International Council for Archaeozoology (ICAZ Fish Remains Working Group, which met at the University of York in 1987. The conference discussed material from many parts of the world - from Australasia to the north-west coast of America - and many eras, ranging in date from the early Pleistocene to the 1980s. It demonstrated both the variety of work being carried out and the growing interest in ancient fish remains. Internet Archaeology plans to publish other batches of papers from this conference. These reports will demonstrate the effort being made to distinguish between assemblages of fish remains which have been deposited by people and those which occur in ancient deposits as a result of the action of other agents. To investigate this area, experiments with modern material and observations of naturally occurring fish bone assemblages are supplemented with detailed analysis of ancient and modern fish remains. The papers published here illustrate the breadth of research into osteology, biogeography, documentary research, and the practicalities of recovering fish remains. Read, digest and enjoy them! Using the Internet for publishing research papers is not only ecologically sound (saving paper, etc. it disseminates scholarship to anyone anywhere on the planet with access to what is gradually becoming necessary technology in the late 20th century. Hopefully, future groups of papers will include video and audio material recorded at the conference, and so enable those who could not attend to gain further insights into the meeting and the scholarship underpinning this area of research.

  19. Surface electromyography studies in standing position confirm that ankle strategy remains disturbed even following successful treatment of patients with a history of sciatica

    Science.gov (United States)

    Huber, Juliusz; Lisiński, Przemysław; Ciesielska, Jagoda; Kulczyk, Aleksandra; Lipiec, Joanna; Bandosz, Agata

    2016-01-01

    [Purpose] It is hypothesized that ankle strategy can be changed in patients with a history of sciatica. The aim of this study was to detect residual disturbances following successful treatment. [Subjects and Methods] In patients with a history of sciatica (N=11) and pseudo-sciatica (N=9), differences in muscle activity were recorded with bilateral surface polyelectromyography and stability measurements (center of foot pressure sway and center of spectrum) in normal standing and tandem positions. Results were compared with recordings in healthy people (N=9) to identify abnormalities in electromyographic and postural studies. [Results] Increased amplitude of electromyographic recordings from the gastrocnemius and extensor digiti muscles on the affected side was detected more in patients with a history of sciatica than pseudo-sciatica syndromes in tandem position. Fewer amplitude fluctuations were observed in both positions preferably in patients following sciatica. Changes in center of foot pressure sway and center of spectrum during balance platform studies were detected in normal standing position in this group of patients. No similar abnormalities in electromyographic and postural studies were detected in healthy people. [Conclusion] Sciatica and pseudo-sciatica evoke persistent disturbances in activity of muscles responsible for ankle strategy. Electromyography differentiates the two groups of patients better than postural studies. PMID:27065544

  20. [PALEOPATHOLOGY OF HUMAN REMAINS].

    Science.gov (United States)

    Minozzi, Simona; Fornaciari, Gino

    2015-01-01

    Many diseases induce alterations in the human skeleton, leaving traces of their presence in ancient remains. Paleopathological examination of human remains not only allows the study of the history and evolution of the disease, but also the reconstruction of health conditions in the past populations. This paper describes the most interesting diseases observed in skeletal samples from the Roman Imperial Age necropoles found in urban and suburban areas of Rome during archaeological excavations in the last decades. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumours, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, the palaeopathological study allowed to highlight the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

  1. EVALUATION OF THE FUNCTIONAL PROPERTIES OF HUMAN ENDOTHELIAL AND SMOOTH MUSCLE CELLS AFTER SEEDING ON THE SURFACE OF NATURAL AND SYNTHETIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Sh. B. Saaya

    2016-01-01

    Full Text Available At present, vascular surgery using small diameter synthetic grafts is associated with a higher incidence of complications (thrombosis, restenosis, intimal hyperplasia than in operations using autologous vessels. However, the occurrence of concomitant pathology, reoperations and multifocal vascular disease limit the use of autologous vein and arteries. The important factor providing a long-term patency is the presence of vascular cells, which produce biologically active substance and provide mechanical properties. Aim. Selection of the optimal scaffold for creating cell-seeded tissue-engineering vessels. Materials and methods. Endothelial (EC and smooth muscle cells (SMC derived from human myocardium were seeded on different surfaces: decellularized homoarteriа, хenopericardium, polytetrafl uoroethylene (PTFE, polyethylene terephthalate (PET, polycaprolactone (PCL and polylactide-co-glycolide (PLGA. Results. Synthetic biodegradable materials polycaprolactone and polylactide-co-glycolide provide cell adhesion. The cells cultured on the polycaprolactone and polylactide-coglycolide scaffolds retain their functional properties: viability and proliferative properties, maintain specifi c endothelial antigens and synthesis of extracellular matrix. Conclusion. Synthetic biodegradable polycaprolactone and polylactide-co-glycolide electrospun scaffolds can be used for creation of cell-fi lled vascular prostheses. 

  2. Dynamic behavior of the water droplet impact on a textured hydrophobic/superhydrophobic surface: the effect of the remaining liquid film arising on the pillars' tops on the contact time.

    Science.gov (United States)

    Li, Xiying; Ma, Xuehu; Lan, Zhong

    2010-04-06

    We have fabricated a series of textured silicon surfaces decorated by square arrays of pillars whose radius and pitch can be adjusted independently. These surfaces possessed a hydrophobic/superhydrophobic property after silanization. The dynamic behavior of water droplets impacting these structured surfaces was examined using a high-speed camera. Experimental results validated that the remaining liquid film on the pillars' tops gave rise to a wet surface instead of a dry surface as the water droplet began to recede away from the textured surfaces. Also, experimental results demonstrated that the difference in the contact time was subjected to the solid fraction referred to as the ratio of the actual area contacting with the liquid to its projected area on the textured surface. Because the mechanism by which the residual liquid film emerges on the pillars' tops can essentially be ascribed to the pinch-off of the liquid threads, we further addressed the changes in the contact time in terms of the characteristic time of pinch-off of an imaginary liquid cylinder whose radius is related to the solid fraction and the maximum contact area. The match of the theoretical analysis and the experimental results substantiates the assumption aforementioned.

  3. Wetting on smooth micropatterned defects

    CERN Document Server

    Debuisson, Damien; Senez, Vincent; Arscott, Steve

    2011-01-01

    We develop a model which predicts the contact angle hysteresis introduced by smooth micropatterned defects. The defects are modeled by a smooth function and the contact angle hysteresis is explained using a tangent line solution. When the liquid micro-meniscus touches both sides of the defect simultaneously, depinning of the contact line occurs. The defects are fabricated using a photoresist and experimental results confirm the model. An important point is that the model is scale-independent, i.e. the contact angle hysteresis is dependent on the aspect ratio of the function, not on its absolute size; this could have implications for natural surface defects.

  4. Smooth Neutrosophic Topological Spaces

    Directory of Open Access Journals (Sweden)

    M. K. EL Gayyar

    2016-08-01

    Full Text Available As a new branch of philosophy, the neutrosophy was presented by Smarandache in 1980. It was presented as the study of origin, nature, and scope of neutralities; as well as their interactions with different ideational spectra. The aim in this paper is to introduce the concepts of smooth neutrosophic topological space, smooth neutrosophic cotopological space, smooth neutrosophic closure, and smooth neutrosophic interior. Furthermore, some properties of these concepts will be investigated.

  5. Smooth Neutrosophic Topological Spaces

    OpenAIRE

    M. K. EL GAYYAR

    2016-01-01

    As a new branch of philosophy, the neutrosophy was presented by Smarandache in 1980. It was presented as the study of origin, nature, and scope of neutralities; as well as their interactions with different ideational spectra. The aim in this paper is to introduce the concepts of smooth neutrosophic topological space, smooth neutrosophic cotopological space, smooth neutrosophic closure, and smooth neutrosophic interior. Furthermore, some properties of these concepts will be investigated.

  6. Smooth K-Theory

    CERN Document Server

    Bunke, Ulrich

    2007-01-01

    We construct an analytic multiplicative model of smooth K-theory. We further introduce the notion of a smooth K-orientation of a proper submersion and define the associated push-forward which satisfies functoriality, compatibility with pull-back diagrams, and projection and bordism formulas. We construct a multiplicative lift of the Chern character from smooth K-theory to smooth rational cohomology and verify that the cohomological version of the Atiyah-Singer index theorem for families lifts to smooth cohomology.

  7. Stability of smooth and rough mini-implants: clinical and biomechanical evaluation - an in vivostudy

    Directory of Open Access Journals (Sweden)

    Giselle Naback Lemes Vilani

    2015-10-01

    Full Text Available Objective: To compare in vivo orthodontic mini-implants (MI of smooth (machined and rough (acid etched surfaces, assessing primary and secondary stability.Methods:Thirty-six (36 MI were inserted in the mandibles of six (6 dogs. Each animal received six (6 MI. In the right hemiarch, three (3 MI without surface treatment (smooth were inserted, whereas in the left hemiarch, another three (3 MI with acid etched surfaces (rough were inserted. The two distal MI in each hemiarch received an immediate load of 1.0 N for 16 weeks, whereas the MI in the mesial extremity was not subject to loading. Stability was measured by insertion and removal torque, initial and final mobility and by inter mini-implant distance.Results:There was no statistical behavioral difference between smooth and rough MI. High insertion torque and reduced initial mobility were observed in all groups, as well as a reduction in removal torques in comparison with insertion torque. Rough MI presented higher removal torque and lower final mobility in comparison to smooth MI. MI did not remain static, with displacement of rough MI being smaller in comparison with smooth MI, but with no statistical difference.Conclusions:MI primary stability was greater than stability measured at removal. There was no difference in stability between smooth and rough MI when assessing mobility, displacement and insertion as well as removal torques.

  8. On the dynamic smoothing of mountains

    Science.gov (United States)

    Bonetti, S.; Porporato, A.

    2017-06-01

    After their formation, mountainous landscapes gradually evolve toward smoother geometries controlled by the interplay of erosion and sedimentation. The statistical mechanical properties of this process and the link between topography and geology have remained largely unexplored. We analyze the slope statistics of different mountains worldwide, showing that landscape age is fingerprinted in their distribution tails. Data reveal a universal relaxation process, through an algebraic decay progressively replaced by an exponential one, with exponents described by a global monotonic function. We then investigate the dominant components of this dynamic smoothing using a landscape evolution model, showing that the time evolution of slope statistics results from a delicate balance between diffusive soil creep, noise, and advective river incision, with the relaxation phase mainly dominated by diffusion. Results may suggest ways to formulate reduced order topographic evolution models for geomorphological and climatological applications, and to explore similarities in surface evolution in different contexts.

  9. Development of a dynamic in vitro model of a stented blood vessel to evaluate the effects of stent strut material selection and surface coating on smooth muscle cell response

    Science.gov (United States)

    Winn, Bradley Huegh

    formation of this new tissue, primarily consisting of VSMCs of the synthetic phenotype and their subsequent extracellular matrix, is the sole causation of in-stent restenosis since the stent serves to prevent elastic recoil and negative remodeling. This doctoral research program is focused on endovascular stent biomaterials science and engineering. Overall, this doctoral project is founded on the hypothesis that smooth muscle cell hyperplasia, as an important causative factor for vascular restenosis following endovascular stent deployment, is triggered by the various effects of stent strut contact on the vessel wall including contact forces and material biocompatibility. In this program, a dynamic in vitro model of a stented blood vessel aimed at evaluating the effect of stent strut material selection, and surface coating on smooth muscle cell response was developed. The in vitro stented artery model was validated through the proliferation of VSMC in contact with stent struts. Additionally, it was demonstrated that, with respect to known biocompatible materials such as Nitinol and 316L stainless steel, DNA synthesis and alpha-actin expression, as indicators of VSMC phenotype, are independent of stent material composition. Furthermore, hydroxyapatite was shown to be a biocompatible stent surface coating with acceptable post-strain integrity. This coating was shown in a feasibility study to be capable of serving as a favorable drug delivery platform able to reliably deliver locally therapeutic doses of bisphosphonates, such as alendronate, to control VSMC proliferation in an in vitro model of a stented blood vessel. This stent coating/drug combination may be effective for reducing restenosis as a result of VSMC hyperplasia in vivo.

  10. Smooth sandwich gravitational waves

    CERN Document Server

    Podolsky, J

    1999-01-01

    Gravitational waves which are smooth and contain two asymptotically flat regions are constructed from the homogeneous pp-waves vacuum solution. Motion of free test particles is calculated explicitly and the limit to an impulsive wave is also considered.

  11. smooth-muscle activity

    African Journals Online (AJOL)

    with atropine could not abolish the effect of the venom on smooth muscle. ... cholenergic factor with acetylcholine was confirmed using radioimmunoassay of ... peripheral nervous antagonists on the venom action are still uncertain. The present.

  12. Smoothing error pitfalls

    Science.gov (United States)

    von Clarmann, T.

    2014-09-01

    The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by a diagnostic quantity called smoothing error. In this paper it is shown that, regardless of the usefulness of the smoothing error as a diagnostic tool in its own right, the concept of the smoothing error as a component of the retrieval error budget is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state; in other words, to characterize the full loss of information with respect to the true atmosphere, the effect of the representation of the atmospheric state on a finite grid also needs to be considered. The idea of a sufficiently fine sampling of this reference atmospheric state is problematic because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help, because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully discuss temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the covariance matrix involved has been evaluated on the comparison grid rather than resulting from interpolation and if the averaging kernel matrices have been evaluated on a grid fine enough to capture all atmospheric variations that the instruments are sensitive to. This is, under the assumptions stated, because the undefined component of the smoothing error, which is the

  13. SPH方法对金属表面微射流的数值模拟%Simulated Microjet from Free Surface of Aluminum Using Smoothed Particle Hydrodynamics

    Institute of Scientific and Technical Information of China (English)

    王裴; 秦承森; 张树道; 刘超

    2004-01-01

    光滑粒子流体动力学(Smoothed Particle Hydrodynamics)方法是一种无网格的拉氏计算方法,具有计算格式简单、易于计算大变形问题等优势.用二维SPH程序模拟了冲击加载下金属铝表面的沟槽状缺陷产生微射流的过程,得到了喷射物的总质量、最大速度和质量-速度曲线.还计算了相同深度、不同夹角的沟槽微射流,并与实验结果进行了比较.结果表明:计算得到的喷射物总质量和最大速度与实验结果符合较好,SPH方法对于估算金属表面的微射流提供了一种有效的数值模拟手段.

  14. Parasite remains in archaeological sites.

    Science.gov (United States)

    Bouchet, Françoise; Guidon, Niéde; Dittmar, Katharina; Harter, Stephanie; Ferreira, Luiz Fernando; Chaves, Sergio Miranda; Reinhard, Karl; Araújo, Adauto

    2003-01-01

    Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefy surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

  15. Parasite remains in archaeological sites

    Directory of Open Access Journals (Sweden)

    Françoise Bouchet

    2003-01-01

    Full Text Available Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefly surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

  16. Acquired smooth muscle hamartoma

    Directory of Open Access Journals (Sweden)

    Bari Arfan ul

    2006-01-01

    Full Text Available Smooth muscle hamartoma is an uncommon, usually congenital, cutaneous hyperplasia of the arrectores pilorum muscles. When it is acquired, it may be confused with Becker′s nevus. We report a case of this rare tumor in a 19-year-old man. The disease started several years ago as multiple small skin-colored papules that subsequently coalesced to form a large soft plaque on the back of the left shoulder. The diagnosis of acquired smooth muscle hamartoma was confirmed on histopathology. The patient was reassured about the benign nature of the lesion and was not advised any treatment.

  17. Revealed smooth nontransitive preferences

    DEFF Research Database (Denmark)

    Keiding, Hans; Tvede, Mich

    2013-01-01

    consumption bundle, all strictly preferred bundles are more expensive than the observed bundle. Our main result is that data sets can be rationalized by a smooth nontransitive preference relation if and only if prices can normalized such that the law of demand is satisfied. Market data sets consist of finitely...... many observations of price vectors, lists of individual incomes and aggregate demands. We apply our main result to characterize market data sets consistent with equilibrium behaviour of pure-exchange economies with smooth nontransitive consumers....

  18. Molecular Dynamics Simulation of Wetting Behavior of Water Nano-droplets on Smooth Surfaces%纳米水滴在光滑壁面上润湿行为的分子动力学模拟

    Institute of Scientific and Technical Information of China (English)

    王甜; 王宝和

    2015-01-01

    Molecular dynamics simulation is applied to research wetting behavior of water nano-droplets on smooth surfaces.Simulation results show that surface widths,thicknesses and water molecular numbers have little influence on the contact angels and vapor-liquid interface thicknesses.With surface potential energy decreasing,the contact angles increase linearly.When the surface potential energy is 1.674 kJ/mol,the contact angel is about 90°.With temperature increasing,the vapor-liquid interface thickness in-creases gradually.The contact angles for the hydrophobic surfaces increases with temperatures increase-ing,the contact angles for the neutral surfaces has no obvious change with temperatures increasing,and the contact angles for the hydrophilic surfaces decrease with temperatures increasing.%采用分子动力学模拟技术,研究了纳米水滴在光滑壁面上的润湿行为规律。模拟结果表明,壁面宽度、厚度以及水分子数对接触角及汽—液界面厚度的影响不大。随着壁面作用势能的减小,接触角线性增大;当壁面作用势能为1.674 kJ/mol时,接触角约为90°。随着温度的提高,汽—液界面厚度逐渐增大;疏水壁面的接触角随温度的提高而逐渐增大;对于中性壁面,温度对接触角影响不大;亲水壁面的接触角随温度的提高而逐渐减小。

  19. Nonequilibrium Flows with Smooth Particle Applied Mechanics.

    Science.gov (United States)

    Kum, Oyeon

    simulations of Rayleigh-Benard convection. Nevertheless, the smooth particle trajectories are essentially Newtonian trajectories, for particles with mass m, subject to an effective potential function 2Pn-^{ -2}w(r). Accordingly, high-pressure subsonic problems, with v^2 << c^2, cannot be reliably solved using this method. A further limitation of the method is its inability to treat free surfaces accurately. Not just subsonic flows can be treated. Shock waves propagate very well in smooth particle systems. For the Richtmyer-Meshkov instability problem with a small amplitude interface perturbation, compared to the wavelength, the interface amplitude grows linearly and the growth rate agrees with the analytic value within 3%. The smooth particle method promises to be of special interest whenever it is desirable to include fluctuations. Smooth particles also provide an interesting eddy viscosity for use in turbulence studies.

  20. Smoothed Particle Hydrodynamic Simulator

    Energy Technology Data Exchange (ETDEWEB)

    2016-10-05

    This code is a highly modular framework for developing smoothed particle hydrodynamic (SPH) simulations running on parallel platforms. The compartmentalization of the code allows for rapid development of new SPH applications and modifications of existing algorithms. The compartmentalization also allows changes in one part of the code used by many applications to instantly be made available to all applications.

  1. Organic Chemicals Remain High Prices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Phenol In early April 2007, China's phenol price remained bullish, and with the restart of phenol/acetone units in Sinopec Beijing Yanhua Petrochemical being ahead of schedule, there were few trading actions in the market, and the price of phenol dropped considerably afterwards.

  2. Transcriptional upregulation of α2δ-1 elevates arterial smooth muscle cell voltage-dependent Ca2+ channel surface expression and cerebrovascular constriction in genetic hypertension.

    Science.gov (United States)

    Bannister, John P; Bulley, Simon; Narayanan, Damodaran; Thomas-Gatewood, Candice; Luzny, Patrik; Pachuau, Judith; Jaggar, Jonathan H

    2012-10-01

    A hallmark of hypertension is an increase in arterial myocyte voltage-dependent Ca2+ (CaV1.2) currents that induces pathological vasoconstriction. CaV1.2 channels are heteromeric complexes composed of a pore-forming CaV1.2α1 with auxiliary α2δ and β subunits. Molecular mechanisms that elevate CaV1.2 currents during hypertension and the potential contribution of CaV1.2 auxiliary subunits are unclear. Here, we investigated the pathological significance of α2δ subunits in vasoconstriction associated with hypertension. Age-dependent development of hypertension in spontaneously hypertensive rats was associated with an unequal elevation in α2δ-1 and CaV1.2α1 mRNA and protein in cerebral artery myocytes, with α2δ-1 increasing more than CaV1.2α1. Other α2δ isoforms did not emerge in hypertension. Myocytes and arteries of hypertensive spontaneously hypertensive rats displayed higher surface-localized α2δ-1 and CaV1.2α1 proteins, surface α2δ-1:CaV1.2α1 ratio, CaV1.2 current density and noninactivating current, and pressure- and depolarization-induced vasoconstriction than those of Wistar-Kyoto controls. Pregabalin, an α2δ-1 ligand, did not alter α2δ-1 or CaV1.2α1 total protein but normalized α2δ-1 and CaV1.2α1 surface expression, surface α2δ-1:CaV1.2α1, CaV1.2 current density and inactivation, and vasoconstriction in myocytes and arteries of hypertensive rats to control levels. Genetic hypertension is associated with an elevation in α2δ-1 expression that promotes surface trafficking of CaV1.2 channels in cerebral artery myocytes. This leads to an increase in CaV1.2 current-density and a reduction in current inactivation that induces vasoconstriction. Data also suggest that α2δ-1 targeting is a novel strategy that may be used to reverse pathological CaV1.2 channel trafficking to induce cerebrovascular dilation in hypertension.

  3. Smooth surfaces in very thin GdBa{sub 2}Cu{sub 3}O{sub 7−δ} films for application in superconducting tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, H., E-mail: henrynavarro@cab.cnea.gov.ar [Instituto Balseiro, Universidad Nacional de Cuyo & CNEA, 8400 Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica. Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Sirena, M. [Instituto Balseiro, Universidad Nacional de Cuyo & CNEA, 8400 Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica. Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Kim, Jeehoon [Department of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); CALDES, Institute for Basic Science, Pohang (Korea, Republic of); Haberkorn, N. [Instituto Balseiro, Universidad Nacional de Cuyo & CNEA, 8400 Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica. Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina)

    2015-03-15

    Highlights: • A detailed study of the morphological properties of GdBa{sub 2}Cu{sub 3}O{sub 7−δ} thin films was realized. • The inclusion of a very thin SrTiO{sub 3} buffer layer modifies the surface of the SrTiO{sub 3} substrates. • The inclusion of the buffer layer suppress the three dimensional nucleation in the GdBa{sub 2}Cu{sub 3}O{sub 7−δ} film. • GdBa{sub 2}Cu{sub 3}O{sub 7−δ} films with large areas free of topological defects and T{sub c} close to liquid nitrogen can be obtained. - Abstract: This paper provides a systematic analysis of the morphology and the superconducting critical temperature obtained in very thin GdBa{sub 2}Cu{sub 3}O{sub 7−δ} films grown on (0 0 1) SrTiO{sub 3} substrates by DC sputtering. We find that the use of a very thin SrTiO{sub 3} buffer layer (≈2 nm) modify the nucleation of GdBa{sub 2}Cu{sub 3}O{sub 7−δ} on the surface of the substrate reducing the formation of 3 dimensional clusters. Our results demonstrate that 16 nm thick GdBa{sub 2}Cu{sub 3}O{sub 7−δ} films with an average root-mean-square (RMS) smaller than 1 nm and large surface areas (up 10 μm{sup 2}) free of 3 dimensional topological defects can be obtained. In films thinner than 24 nm the onset (zero resistance) of superconducting transition of the films is reduced, being close to liquid nitrogen. This fact can be associated with stress reducing the orthorhombicity and slightly drop in oxygen stoichiometry.

  4. Influence of surface smoothing on spin Seebeck effect of Ce1Y2Fe5O12 deposited by metal organic decomposition

    Science.gov (United States)

    Hirata, Satoshi; Ono, Tatsuyoshi; Amemiya, Yoshiteru; Tabei, Tetsuo; Yokoyama, Shin

    2017-04-01

    Thus far, Bi1Y2Fe5O12 (Bi:YIG) films deposited by metal organic decomposition (MOD) are mainly used for magnetic insulation film of spin Seebeck devices. In order to increase the power conversion efficiency of these devices, we focused on Ce1Y2Fe5O12 (Ce:YIG), which has a larger Faraday rotation than Bi:YIG. Since there has been no report, except for the patent document, concerning the deposition of Ce:YIG films by MOD, we investigated the appropriate annealing temperatures, and we found that Ce:YIG films are crystallized when the annealing temperature is over 800 °C. However, since no electromotive force has been observed, we checked the surface roughness of Ce:YIG films by atomic force microscopy (AFM). Since their surfaces of Ce:YIG films were very rough, it was mechanically polished (MP). Then, an electromotive force of, at most, 11.3 µV was generated. This is the first report concerning the spin Seebeck effect of Ce:YIG deposited by MOD.

  5. Smooth e-beam-deposited tin-doped indium oxide for III-nitride vertical-cavity surface-emitting laser intracavity contacts

    Science.gov (United States)

    Leonard, J. T.; Cohen, D. A.; Yonkee, B. P.; Farrell, R. M.; DenBaars, S. P.; Speck, J. S.; Nakamura, S.

    2015-10-01

    We carried out a series of simulations analyzing the dependence of mirror reflectance, threshold current density, and differential efficiency on the scattering loss caused by the roughness of tin-doped indium oxide (ITO) intracavity contacts for 405 nm flip-chip III-nitride vertical-cavity surface-emitting lasers (VCSELs). From these results, we determined that the ITO root-mean-square (RMS) roughness should be <1 nm to minimize scattering losses in VCSELs. Motivated by this requirement, we investigated the surface morphology and optoelectronic properties of electron-beam (e-beam) evaporated ITO films, as a function of substrate temperature and oxygen flow and pressure. The transparency and conductivity were seen to increase with increasing temperature. Decreasing the oxygen flow and pressure resulted in an increase in the transparency and resistivity. Neither the temperature, nor oxygen flow and pressure series on single-layer ITO films resulted in highly transparent and conductive films with <1 nm RMS roughness. To achieve <1 nm RMS roughness with good optoelectronic properties, a multi-layer ITO film was developed, utilizing a two-step temperature scheme. The optimized multi-layer ITO films had an RMS roughness of <1 nm, along with a high transparency (˜90% at 405 nm) and low resistivity (˜2 × 10-4 Ω-cm). This multi-layer ITO e-beam deposition technique is expected to prevent p-GaN plasma damage, typically observed in sputtered ITO films on p-GaN, while simultaneously reducing the threshold current density and increasing the differential efficiency of III-nitride VCSELs.

  6. Smooth Neighborhood Structures in a Smooth Topological Spaces

    Directory of Open Access Journals (Sweden)

    A. A. Ramadan

    2010-01-01

    Full Text Available Various concepts related to a smooth topological spaces have been introduced and relations among them studied by several authors (Chattopadhyay, Ramadan, etc. In this study, we presented the notions of three sorts of neighborhood structures of a smooth topological spaces and give some of their properties which are results by Ying extended to smooth topological spaces.

  7. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Benedictus Margaux

    2015-05-01

    Let be a scheme. Assume that we are given an action of the one dimensional split torus $\\mathbb{G}_{m,S}$ on a smooth affine -scheme $\\mathfrak{X}$. We consider the limit (also called attractor) subfunctor $\\mathfrak{X}_{}$ consisting of points whose orbit under the given action `admits a limit at 0’. We show that $\\mathfrak{X}_{}$ is representable by a smooth closed subscheme of $\\mathfrak{X}$. This result generalizes a theorem of Conrad et al. (Pseudo-reductive groups (2010) Cambridge Univ. Press) where the case when $\\mathfrak{X}$ is an affine smooth group and $\\mathbb{G}_{m,S}$ acts as a group automorphisms of $\\mathfrak{X}$ is considered. It also occurs as a special case of a recent result by Drinfeld on the action of $\\mathbb{G}_{m,S}$ on algebraic spaces (Proposition 1.4.20 of Drinfeld V, On algebraic spaces with an action of $\\mathfrak{G}_{m}$, preprint 2013) in case is of finite type over a field.

  8. Alarms Remain,Efforts Continue

    Institute of Scientific and Technical Information of China (English)

    Alice

    2007-01-01

    @@ China must come to terms with the fact that it has quality problems in at least 1% of its products.Though there is no country in the world that can completely avoid problems,given the responsible role China plays on the intemational stage,China should stop to take a look at itself and find ways to improve.China must examine herself carefully,when looking at the production chain;we have to keep aware that some alarms still remain.

  9. 蜂窝夹芯板表面加工的平整度分析%Surface Artifactitious Smoothness Analysis of Honeycomb Sandwich Panel

    Institute of Scientific and Technical Information of China (English)

    夏盛来; 何景武; 王耀东

    2012-01-01

    Honeycomb sandwich structure with high specific strength, stiffness and light weight, etc. , are widely used in aerospace applications. Therefore, analysis of its mechanical properties has a great value in theoretical research and engineering application. Using the honeycomb sandwich panels that are commonly used for the satellite structure, sandwich panel test measured the surface roughness. According to theory, this paper deduced the equivalent material parameters of honeycomb sandwich structure, and also analyzed the panel surface roughness with finite element software MSC. Patran/ Nastran. Comparison between the test results and calculate results with the difference of 5. 9%, indicate the feasibility of theoretical derivation. According to the equivalent sandwich theory, proposed the establishment of the equivalent coefficient database about the cellular equivalent parameters which was the common specifications, facilitating the engineering applications of honeycomb sandwich structure.%蜂窝夹芯结构具有高的比强度、比刚度以及质量轻等优点,被广泛应用于航空航天领域.因此,对其进行力学特性分析具有理论研究和工程应用价值.针对卫星常用的蜂窝夹芯结构板,实验测得夹芯板的表面平整度.根据理论推导得出蜂窝夹芯结构的等效材料参数,利用有限元分析软件MSC.Patran/Nastran进行蜂窝夹芯板的表面平整度分析.对比发现,实验结果和计算分析结果相差为5.9%,表明理论推导的可行性.根据三明治等效理论,提出建立常用规格的蜂窝的等效参数的等效系数库,便于蜂窝夹芯结构的工程应用.

  10. Anti-smooth muscle antibody

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003531.htm Anti-smooth muscle antibody To use the sharing features on this page, please enable JavaScript. Anti-smooth muscle antibody is a blood test that detects the ...

  11. EMBEDDING FLOWS AND SMOOTH CONJUGACY

    Institute of Scientific and Technical Information of China (English)

    ZHANGMEIRONG; LIWEIGU

    1997-01-01

    The authors use the functional equation for embedding vector fields to study smooth embedding flows of one-dimensional diffeomorphisms. The existence and uniqueness for smooth embedding flows and vector fields are proved. As an application of embedding flows, some classification results about local and giobal diffeomorphisms under smooth conjugacy are given.

  12. And the Dead Remain Behind

    Directory of Open Access Journals (Sweden)

    Peter Read

    2013-08-01

    Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

  13. Compensating for estimation smoothing in kriging

    Science.gov (United States)

    Olea, R.A.; Pawlowsky, Vera

    1996-01-01

    Smoothing is a characteristic inherent to all minimum mean-square-error spatial estimators such as kriging. Cross-validation can be used to detect and model such smoothing. Inversion of the model produces a new estimator-compensated kriging. A numerical comparison based on an exhaustive permeability sampling of a 4-fr2 slab of Berea Sandstone shows that the estimation surface generated by compensated kriging has properties intermediate between those generated by ordinary kriging and stochastic realizations resulting from simulated annealing and sequential Gaussian simulation. The frequency distribution is well reproduced by the compensated kriging surface, which also approximates the experimental semivariogram well - better than ordinary kriging, but not as well as stochastic realizations. Compensated kriging produces surfaces that are more accurate than stochastic realizations, but not as accurate as ordinary kriging. ?? 1996 International Association for Mathematical Geology.

  14. Experimental Study of Pool Boiling of FC-72 Over Smooth Surface Under Microgravity%微重力下光滑表面上FC-72的池沸腾实验研究

    Institute of Scientific and Technical Information of China (English)

    薛艳芳; 魏进家; 赵建福; 李晶; 郭栋; 万士昕

    2011-01-01

    Experiments of subcooled pool boiling of FC-72 on a small scale smooth silicon chip with the dimensions of 10 mm×10 mm×0.5 mm were studied in short-term microgravity utilizing Drop-Tower Beijing with duration of about 3.6 s. The smooth silicon chip was heated by means of controlling heating current for the desired heat flux. The results indicate that steady or quasi-steady nucleate pool boiling was observed in the experiments in low and intermediate heat flux regions. The performance of boiling heat transfer can be maintained unchanged. It is found that the oscillation due to coalescence of adjacent bubbles is the primary reason of bubbles departure in microgravity condition in intermediate heat flux regime. At high heat fluxes, a large coalesced bubble forms quickly and covers the heater surface completely in microgravity, followed by shrinking to an oblate in shape and smooth in contour due to the highly subcooled condensation. The mean heater surface temperature increases significantly, which indicates the deterioration of boiling heat transfer. It is possible for the occurrence of local dry-out or transition to film boiling at the bottom of the large coalesced bubble.%本文利用小尺度光滑芯片(10 mmxl0 mmx0.5 mm),通过控制加热电流方法,在北京落塔进行了持续3.6 s有效微重力时间的过冷池沸腾实验研究.在低热流和中等热流区,微重力条件下可以观察到稳态或准稳态池沸腾现象,传热特性基本维持不变;在中等热流区域,气泡的横向合并会引起合并后的大气泡表面剧烈震荡,进而引发合并大气泡从加热表面脱落.在高热流密度区,微重力条件下加热表面很快形成半球形状并几乎完全覆盖其表面的聚合大气泡;随后,由于高过冷液体冷凝作用,聚合大气泡收缩为半椭球形状,界面也变得更为光滑,且完全覆盖了加热表面,壁温曲线明显升高,可能提前发生临界热流或转变为膜态沸腾,导致微重力条件下沸腾换热显著恶化.

  15. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  16. Droplet deformation and surface tension modeling using the smoothed particle hydrodynamics method%液滴变形及表面张力模拟的光滑粒子动力学方法

    Institute of Scientific and Technical Information of China (English)

    刘栋; 郭印诚; 林文漪

    2013-01-01

    光滑粒子动力学(smoothed particle hydrodynamics,SPH)方法是一种Lagrange无网格粒子方法,在多相流模拟方向有着巨大的潜力.液体表面张力是多相流动的一个很重要的作用力.该文采用连续表面力(continuum surface force,CSF)模型和粒子间相互作用力(inter-particle interaction force,IIF)模型在SPH方法中引入表面张力,比较了这两种模型对液滴变形过程的模拟.CSF模型与理论结果之间的比较表明,CSF模型很好地模拟表面张力的效应.而IIF模型虽然也可以用于计算表面张力,但与CSF模型相比,其模型参数的确定较为困难.

  17. Classification of smooth Fano polytopes

    DEFF Research Database (Denmark)

    Øbro, Mikkel

    Fano polytopes up to isomorphism. A smooth Fano -polytope can have at most vertices. In case of vertices an explicit classification is known. The thesis contains the classification in case of vertices. Classifications of smooth Fano -polytopes for fixed exist only for . In the thesis an algorithm...... for the classification of smooth Fano -polytopes for any given is presented. The algorithm has been implemented and used to obtain the complete classification for .......A simplicial lattice polytope containing the origin in the interior is called a smooth Fano polytope, if the vertices of every facet is a basis of the lattice. The study of smooth Fano polytopes is motivated by their connection to toric varieties. The thesis concerns the classification of smooth...

  18. Evaporation of sessile droplets on smooth and structured substrates

    Science.gov (United States)

    Colinet, Pierre; Flandroy, Marie; Dehaeck, Sam; Rednikov, Alexey; Sobac, Benjamin; Tsoumpas, Yannis

    2015-11-01

    Evaporation of sessile droplets remains a topic of active research nowadays, not only due to its widespread occurrence both in nature and technology, but also because it raises a number of interesting fundamental questions. Among these, the influence of the substrate topography is far from being understood. In this presentation, we focus on the difference between droplet evaporation dynamics on a smooth substrate and on substrates with controlled geometrical heterogeneities (square or hexagonal arrays of cylindrical pillars). While the wetting dynamics of droplets on such structured substrates has already been studied (in particular it is known that the droplet shape typically tends to adopt the symmetry of the pattern it lies upon), the influence the structure has on the evaporation dynamics (including the influence of pinning) has not yet received much attention. From interferometric measurements of droplet shapes, we highlight in particular that the evaporation from structured substrates is generally faster than on smooth substrates, and that the scaling exponents characterizing the evolution of radius versus time are also different. Pinning is also shown to be favored above a certain surface fraction of pillars, both for hexagonal and square arrays. Financial support of FRS-FNRS, ESA-BELSPO PRODEX, ULB, and BELSPO IAP 7/38 is gratefully acknowledged.

  19. Air flow through smooth and rough cracks

    Energy Technology Data Exchange (ETDEWEB)

    Kula, H.-G.; Sharples, S. [Sheffield Univ. (United Kingdom). Dept. of Building Science

    1994-12-31

    A series of laboratory experiments are described which investigated the effect of surface roughness on the air flow characteristics of simple, straight-through, no-bend cracks with smooth and rough internal surfaces. The crack thicknesses used in the study were 1.0, 1.5 and 2.0mm. The crack lengths, in the direction of flow, were 50.8mm and 76.2mm. For the rough cracks the roughness was simulated with two different grades of commercially available energy-cloth (grade 60 and 100). The experimental results were satisfactorily fitted to a quadratic relationship between {Delta}p and Q of the form {Delta}p = AQ + BQ{sup 2} for both the smooth and rough crack data. The effect of roughness on the reduction of air flowing through a crack is also discussed. (author)

  20. Modeling Water Waves with Smoothed Particle Hydrodynamics

    Science.gov (United States)

    2013-09-30

    flows, such as undertow, longshore currents, and rip currents. APPROACH The approach is based on improving various aspects of the SPH code ...Smoothed Particle Hydrodynamics ( SPH ) is a meshless numerical method that is being developed for the study of nearshore waves and other Navy needs. The...Lagrangian nature of SPH allows the modeling of wave breaking, surf zones, ship waves, and wave-structure interaction, where the free surface becomes

  1. Evaluation of Pulsed Oral Irrigator Against Plaque on Smooth Surfaces and Gingivitis%脉冲式冲牙器抑制牙菌斑和牙龈炎的效果评价

    Institute of Scientific and Technical Information of China (English)

    冯岩; 林樑钦; 陈瑞斌; 黄晓宇; 张燕; 邓曲

    2012-01-01

    Objective To explore the effect of oral irrigation as an auxiliary method on reducing the accumulation of plaque on smooth surface and gingivitis among the adults. Methods Thirty volunteers between 18 and 23 were randomly divided into three groups: brushing group, oral irrigation group and brushing combined with oral irrigation group. The volunteers were required to have the baseline checking with plaque index(PI) and gingivitis index(GI). After being scaled and polished, the three groups used different ways to have the Oral Hygiene. After 2 and 4 weeks, subjects were evaluated for PI and GI. Results Compared with the results of two weeks later, PI of the brushing group, oral irrigation group and brushing combined with oral irrigation group respectively reduced 22. 17%, 44. 59% and 34. 17% after 4 weeks. Meanwhile, GI of brushing group and brushing combined with oral irrigation group increased 14. 31% and 82. 19% after 4 weeks. But GI of the irrigation group reduced 13. 63%. Conclusion The oral irrigation can reduce the plaque on smooth surface in a short-term and it should be used as an auxiliary method to prevent and control periodontitis.%目的 探讨以脉冲式冲牙器作为机械性控制菌斑的辅助措施下抑制光滑面菌斑积聚和牙龈炎的效果.方法 将30名18~23周岁的青年志愿者随机均分为3组,即单纯刷牙组、单纯使用冲牙器组和刷牙加冲牙器组,在对受检者进行彻底的龈上洁治和牙面抛光的基础上,比较3组受检者使用不同的口腔清洁措施2,4周后的菌斑指数和龈炎指数的变化情况.结果 3组的龈炎指数均先上升后下降;使用4周与2周比较,3组受试对象的菌斑指数分别下降了22.17%,44.59%,34.17%,而龈炎指数则表现为单纯使用冲牙器组下降了13.63%,单纯刷牙组、刷牙加用冲牙器组则分别上升了14.31%,82.19%.结论 脉冲式冲牙器能够在短期内抑制光滑面的菌斑形成,可以作为预防和控制牙周疾病的一种辅助方法.

  2. The Topological Effects of Smoothing.

    Science.gov (United States)

    Shafii, S; Dillard, S E; Hlawitschka, M; Hamann, B

    2012-01-01

    Scientific data sets generated by numerical simulations or experimental measurements often contain a substantial amount of noise. Smoothing the data removes noise but can have potentially drastic effects on the qualitative nature of the data, thereby influencing its characterization and visualization via topological analysis, for example. We propose a method to track topological changes throughout the smoothing process. As a preprocessing step, we oversmooth the data and collect a list of topological events, specifically the creation and destruction of extremal points. During rendering, it is possible to select the number of topological events by interactively manipulating a merging parameter. The result that a specific amount of smoothing has on the topology of the data is illustrated using a topology-derived transfer function that relates region connectivity of the smoothed data to the original regions of the unsmoothed data. This approach enables visual as well as quantitative analysis of the topological effects of smoothing.

  3. Conservative smoothing versus artificial viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, C.; Hicks, D.L. [Michigan Technological Univ., Houghton, MI (United States); Swegle, J.W. [Sandia National Labs., Albuquerque, NM (United States). Solid and Structural Mechanics Dept.

    1994-08-01

    This report was stimulated by some recent investigations of S.P.H. (Smoothed Particle Hydrodynamics method). Solid dynamics computations with S.P.H. show symptoms of instabilities which are not eliminated by artificial viscosities. Both analysis and experiment indicate that conservative smoothing eliminates the instabilities in S.P.H. computations which artificial viscosities cannot. Questions were raised as to whether conservative smoothing might smear solutions more than artificial viscosity. Conservative smoothing, properly used, can produce more accurate solutions than the von Neumann-Richtmyer-Landshoff artificial viscosity which has been the standard for many years. The authors illustrate this using the vNR scheme on a test problem with known exact solution involving a shock collision in an ideal gas. They show that the norms of the errors with conservative smoothing are significantly smaller than the norms of the errors with artificial viscosity.

  4. Smoothness in Binomial Edge Ideals

    Directory of Open Access Journals (Sweden)

    Hamid Damadi

    2016-06-01

    Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

  5. Time Critical Isosurface Refinement and Smoothing

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, V.; Bajaj, C.L.

    2000-07-10

    Multi-resolution data-structures and algorithms are key in Visualization to achieve real-time interaction with large data-sets. Research has been primarily focused on the off-line construction of such representations mostly using decimation schemes. Drawbacks of this class of approaches include: (i) the inability to maintain interactivity when the displayed surface changes frequently, (ii) inability to control the global geometry of the embedding (no self-intersections) of any approximated level of detail of the output surface. In this paper we introduce a technique for on-line construction and smoothing of progressive isosurfaces. Our hybrid approach combines the flexibility of a progressive multi-resolution representation with the advantages of a recursive sub-division scheme. Our main contributions are: (i) a progressive algorithm that builds a multi-resolution surface by successive refinements so that a coarse representation of the output is generated as soon as a coarse representation of the input is provided, (ii) application of the same scheme to smooth the surface by means of a 3D recursive subdivision rule, (iii) a multi-resolution representation where any adaptively selected level of detail surface is guaranteed to be free of self-intersections.

  6. Smooth analysis in Banach spaces

    CERN Document Server

    Hájek, Petr

    2014-01-01

    This bookis aboutthe subject of higher smoothness in separable real Banach spaces.It brings together several angles of view on polynomials, both in finite and infinite setting.Also a rather thorough and systematic view of the more recent results, and the authors work is given. The book revolves around two main broad questions: What is the best smoothness of a given Banach space, and its structural consequences? How large is a supply of smooth functions in the sense of approximating continuous functions in the uniform topology, i.e. how does the Stone-Weierstrass theorem generalize into in

  7. SMOOTHING BY CONVEX QUADRATIC PROGRAMMING

    Institute of Scientific and Technical Information of China (English)

    Bing-sheng He; Yu-mei Wang

    2005-01-01

    In this paper, we study the relaxed smoothing problems with general closed convex constraints. It is pointed out that such problems can be converted to a convex quadratic minimization problem for which there are good programs in software libraries.

  8. Wetting on smooth micropatterned defects

    OpenAIRE

    Debuisson, Damien; Dufour, Renaud; Senez, Vincent; Arscott, Steve

    2011-01-01

    We develop a model which predicts the contact angle hysteresis introduced by smooth micropatterned defects. The defects are modeled by a smooth function and the contact angle hysteresis is explained using a tangent line solution. When the liquid micro-meniscus touches both sides of the defect simultaneously, depinning of the contact line occurs. The defects are fabricated using a photoresist and experimental results confirm the model. An important point is that the model is scale-independent,...

  9. Smooth quantum gravity: Exotic smoothness and Quantum gravity

    CERN Document Server

    Asselmeyer-Maluga, Torsten

    2016-01-01

    Over the last two decades, many unexpected relations between exotic smoothness, e.g. exotic $\\mathbb{R}^{4}$, and quantum field theory were found. Some of these relations are rooted in a relation to superstring theory and quantum gravity. Therefore one would expect that exotic smoothness is directly related to the quantization of general relativity. In this article we will support this conjecture and develop a new approach to quantum gravity called \\emph{smooth quantum gravity} by using smooth 4-manifolds with an exotic smoothness structure. In particular we discuss the appearance of a wildly embedded 3-manifold which we identify with a quantum state. Furthermore, we analyze this quantum state by using foliation theory and relate it to an element in an operator algebra. Then we describe a set of geometric, non-commutative operators, the skein algebra, which can be used to determine the geometry of a 3-manifold. This operator algebra can be understood as a deformation quantization of the classical Poisson alge...

  10. A fibroblast-associated antigen: Characterization in fibroblasts and immunoreactivity in smooth muscle differentiated stromal cells

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Celis, Julio E.; van Deurs, Bo

    1992-01-01

    Fibroblasts with smooth muscle differentiation are frequently derived from human breast tissue. Immunofluorescence cytochemistry of a fibroblast-associated antigen recognized by a monoclonal antibody (MAb), 1B10, was analyzed with a view to discriminating smooth muscle differentiated fibroblasts...... from vascular smooth muscle cells. The antigen was detected on the cell surface and in cathepsin D-positive and acridine orange-accumulating vesicular compartments of fibroblasts. Ultrastructurally, the antigen was revealed in coated pits and in endosomal and lysosomal structures. 1B10 recognized three...... immunoreactivity was specific to fibroblasts and smooth muscle differentiated fibroblasts within the context of vascular smooth muscle cells....

  11. Research on theManufacturing Mechanism and Technology of Atomically Smooth Surfaces%原子级光滑表面的制造技术与机理研究

    Institute of Scientific and Technical Information of China (English)

    潘国顺; 雒建斌; 路新春; 郭丹; 段芳莉; 徐进; 陈入领; 张伟; 胡元中

    2011-01-01

    methods in Precise-Microscopic and Digitalized Design and Manufacture for High-Performance Electronic Products". These achievements include breakthrough in several key techniques of Chemical-Mechanical Polishing (CMP), research on the mechanism of CMP, and computer simulations and experimental studies on nano-particle behavior in CMP. Experiments, theoretical analyses and computer simulations were carried out concerning manufacture of atomically smooth surfaces and CMP. The study covered various aspects of the subject: screening of solid abrasive particles,surface modification and dispersion of abrasive particles,optimization of particle size and content; understanding the functions of slurry components such as oxidant, complex agent, sustained-release agent and other chemical additives;optimization of technical parameters like pressure and speed in CMP process,molecular dynamics simulations of nano-particle behavior and collision between nano-cluster and silicon substrate, impact test between nano-particle and substrate, fluorescent tracing on nano-particle motion in two-phase flow and CMP, etc. Results show that solid abrasive particles in slurry can play a significant role in material removal and formation of high quality surfaces during CMP process. To diminish particle size would be beneficial for improving surface quality in general, but the key lies in ensuring uniform particle size,for large particle may lead to surface scratch or other defects. High quality of polished surfaces and high rate of material removal can be realized by optimizing the size and content of abrasive particles. Apart from solid abrasive particles, CMP slurry also contains various components such as oxidant .complex agent,sustained-release agent and other chemical additives. The role of oxidant is to react with the surface of workpiece to be polished and form a passivation layer, which is soft and easy to be removed by abrasion of polishing pad and solid particles, creating a cyclic process

  12. Smooth Nanowire/Polymer Composite Transparent Electrodes

    KAUST Repository

    Gaynor, Whitney

    2011-04-29

    Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Scott's Lake Excavation Letters on Human Remains

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is two letters written about the repatriation of Santee Indian human remains and funerary objects to Santee Sioux Tribe. Includes an inventory of human remains...

  14. Condensation of refrigerants flowing inside smooth and corrugated tubes

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, D.L. [Tennessee State Univ., Nashville, TN (United States); Conklin, J.C.; Vineyard, E.A. [Oak Ridge National Lab., TN (United States)

    1995-07-01

    Because heat exchanger thermal performance has a direct fluence on the overall cycle performance of vapor-compression refrigeration machinery,enhanced heat transfer surfaces are of interest to improve the efficiency of heat pumps and air conditioners. We investigated R-22 and a nonazeotropic refrigerant mixture (NARM) of 75% R-143a and 25% R-124 (by mass) to study their thermal performance in a condenser made of conventional smooth tubes and another condenser made of corrugated, or spirally indented, tubes. We investigated the condensing heat transfer and pressure drop characteristics in an experimental test loop model of a domestic beat pump system employing a variable speed compressor. The refrigerant circulates inside the central tube and the water circulates in the annulus. At refrigerant mass fluxes of approximately 275--300 kg/m{sup 2}s, the measured irreversible pressure drop of the corrugated surface was 23% higher than that of the smooth surface for the R-22. At refrigerant mass fluxes of 350-370 kg/m{sup 2}s, the irreversible pressure drop of the corrugated surface was 36% higher than that of the smooth surface for the NARM. The average heat transfer coefficient for the corrugated surface for R-22 was roughly 40% higher than that for the smooth tube surface at refrigerant mass fluxes of 275--295 kg/m{sup 2}s. The average heat transfer coefficient for the corrugated surface for the NARM was typically 70% higher than that for the smooth tube surface at refrigerant mass fluxes of 340--385 kg/m{sup 2}s.

  15. Selective Smoothed Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The paper examines three selective schemes for the smoothed finite element method (SFEM) which was formulated by incorporating a cell-wise strain smoothing operation into the standard compatible finite element method (FEM). These selective SFEM schemes were formulated based on three selective integration FEM schemes with similar properties found between the number of smoothing cells in the SFEM and the number of Gaussian integration points in the FEM. Both scheme 1 and scheme 2 are free of nearly incompressible locking, but scheme 2 is more general and gives better results than scheme 1. In addition, scheme 2 can be applied to anisotropic and nonlinear situations, while scheme 1 can only be applied to isotropic and linear situations. Scheme 3 is free of shear locking. This scheme can be applied to plate and shell problems. Results of the numerical study show that the selective SFEM schemes give more accurate results than the FEM schemes.

  16. α-compactness in smooth topological spaces

    Directory of Open Access Journals (Sweden)

    Chun-Kee Park

    2003-01-01

    Full Text Available We introduce the concepts of smooth α-closure and smooth α-interior of a fuzzy set which are generalizations of smooth closure and smooth interior of a fuzzy set defined by Demirci (1997 and obtain some of their structural properties.

  17. Restorative resins: hardness and strength vs. quantity of remaining double bonds.

    Science.gov (United States)

    Asmussen, E

    1982-12-01

    It has been hypothesized that the Wallace indentation hardness of smooth surface resins is a factor of prime importance for the abrasion by food of Class 1 restorations. In the present work factors affecting the hardness of polymers were investigated. In addition the tensile strength of composite resins was measured and related to the catalytic system of the polymer. It was found that for a given composition of the monomer the Wallace hardness number increased with increasing content of inhibitor, decreased with increasing content of peroxide, and was unaffected by changes in the content of amine. The hardness was well correlated with the quantity of double bonds remaining in the polymer. BISGMA-based polymers showed no variation in hardness when the originating monomer varied with respect to content of a bi- or a trifunctional diluting monomer. Light-polymerized polymers were relatively hard as compared to chemically cured materials of adequate setting time. The tensile strength of composite resins was predominantly determined by the monomer content of peroxide and increased herewith. The tensile strength was well correlated with the quantity of remaining double bonds in the constituting polymer.

  18. Extracellular proteolysis and the migrating vascular smooth muscle cell

    NARCIS (Netherlands)

    Leeuwen, R.T.J. van

    1996-01-01

    Smooth muscle cells (SMC) form the major cell type in the arterial blood vessels. In the undamaged vessel wall they remain in a contractile state characterized by the absence of cell division, a low metabolic activity and a high actin-myosin content. As a reaction to injury of the vessel wall they c

  19. Ureter smooth muscle cell orientation in rat is predominantly longitudinal.

    Directory of Open Access Journals (Sweden)

    Bart Spronck

    Full Text Available In ureter peristalsis, the orientation of the contracting smooth muscle cells is essential, yet current descriptions of orientation and composition of the smooth muscle layer in human as well as in rat ureter are inconsistent. The present study aims to improve quantification of smooth muscle orientation in rat ureters as a basis for mechanistic understanding of peristalsis. A crucial step in our approach is to use two-photon laser scanning microscopy and image analysis providing objective, quantitative data on smooth muscle cell orientation in intact ureters, avoiding the usual sectioning artifacts. In 36 rat ureter segments, originating from a proximal, middle or distal site and from a left or right ureter, we found close to the adventitia a well-defined longitudinal smooth muscle orientation. Towards the lamina propria, the orientation gradually became slightly more disperse, yet the main orientation remained longitudinal. We conclude that smooth muscle cell orientation in rat ureter is predominantly longitudinal, though the orientation gradually becomes more disperse towards the proprial side. These findings do not support identification of separate layers. The observed longitudinal orientation suggests that smooth muscle contraction would rather cause local shortening of the ureter, than cause luminal constriction. However, the net-like connective tissue of the ureter wall may translate local longitudinal shortening into co-local luminal constriction, facilitating peristalsis. Our quantitative, minimally invasive approach is a crucial step towards more mechanistic insight into ureter peristalsis, and may also be used to study smooth muscle cell orientation in other tube-like structures like gut and blood vessels.

  20. Dynamic smoothing of nanocomposite films

    NARCIS (Netherlands)

    Pei, Y.T.; Turkin, A; Chen, C.Q.; Shaha, K.P.; Vainshtein, D.; Hosson, J.Th.M. De

    2010-01-01

    In contrast to the commonly observed dynamic roughening in film growth we have observed dynamic smoothing in the growth of diamondlike-carbon nanocomposite (TiC/a-C) films up to 1.5 mu m thickness. Analytical and numerical simulations, based on the Edwards-Wilkinson model and the Mullins model, visu

  1. Nonlinear smoothing for random fields

    NARCIS (Netherlands)

    Aihara, Shin Ichi; Bagchi, Arunabha

    1995-01-01

    Stochastic nonlinear elliptic partial differential equations with white noise disturbances are studied in the countably additive measure set up. Introducing the Onsager-Machlup function to the system model, the smoothing problem for maximizing the modified likelihood functional is solved and the exp

  2. Investigating the Impact of Acetone Vapor Smoothing on the Strength and Elongation of Printed ABS Parts

    Science.gov (United States)

    Gao, Harry; Kaweesa, Dorcas V.; Moore, Jacob; Meisel, Nicholas A.

    2017-03-01

    Acetone vapor smoothing is a chemical treatment that "melts" the surface of additively manufactured acrylonitrile butadiene styrene parts. The process fuses layers together and allows them to reform when vapor is removed, resulting in a smooth surface finish. Although commonly used to improve aesthetics, recent work has begun to investigate the effects of vapor smoothing on part strength. Nevertheless, most of this work has failed to take into account the anisotropic nature of printed parts. Prior research has shown that vapor smoothing reduces strength under best-case loading conditions, when the tensile load is parallel with the direction of the layers. In this article, the authors hypothesize that vapor smoothing may increase strength under nonoptimal loading conditions as a result of increased cohesion between layers and a reduction in stress concentrations. They use a design of experiments approach to identify the combined impact of printing and vapor smoothing parameters on part material properties.

  3. Role of mobile IPv6 for mobile networks and its remaining issues

    Science.gov (United States)

    Ma, Jian; Kan, Zhigang

    2001-10-01

    Mobile IPv6 has received tremendous attention from the cellular telephony industry for use in the next generation networks. This paper starts with recent development of Mobile IPv6 technologies and its standards, and explores remaining issues such as fast handover, smooth handover, mobility managements, AAA, QoS, security and scenarios in its deployment, with particular attention to IPv6.

  4. Luminescence of thermally altered human skeletal remains

    NARCIS (Netherlands)

    Krap, Tristan; Nota, Kevin; Wilk, Leah; van de Goot, Frank; Ruijter, Jan; Duijst, Wilma; Oostra, Roelof Jan

    2017-01-01

    Literature on luminescent properties of thermally altered human remains is scarce and contradictory. Therefore, the luminescence of heated bone was systemically reinvestigated. A heating experiment was conducted on fresh human bone, in two different media, and cremated human remains were recovered

  5. Mammalian Remains from Indian Sites on Aruba

    NARCIS (Netherlands)

    Hooijer, D.A.

    1960-01-01

    Mr. H. R. VAN HEEKEREN and Mr. C. J. DU RY, of the Rijksmuseum voor Volkenkunde at Leiden, entrusted me with the identification of some animal remains collected from Indian sites on Aruba by Professor J. P. B. DE JOSSELIN DE JONG in 1923. These remains relate for the most part to marine turtles (Che

  6. Multiscale modeling with smoothed dissipative particle dynamics.

    Science.gov (United States)

    Kulkarni, Pandurang M; Fu, Chia-Chun; Shell, M Scott; Leal, L Gary

    2013-06-21

    In this work, we consider two issues related to the use of Smoothed Dissipative Particle Dynamics (SDPD) as an intermediate mesoscale model in a multiscale scheme for solution of flow problems when there are local parts of a macroscopic domain that require molecular resolution. The first is to demonstrate that SDPD with different levels of resolution can accurately represent the fluid properties from the continuum scale all the way to the molecular scale. Specifically, while the thermodynamic quantities such as temperature, pressure, and average density remain scale-invariant, we demonstrate that the dynamic properties are quantitatively consistent with an all-atom Lennard-Jones reference system when the SDPD resolution approaches the atomistic scale. This supports the idea that SDPD can serve as a natural bridge between molecular and continuum descriptions. In the second part, a simple multiscale methodology is proposed within the SDPD framework that allows several levels of resolution within a single domain. Each particle is characterized by a unique physical length scale called the smoothing length, which is inversely related to the local number density and can change on-the-fly. This multiscale methodology is shown to accurately reproduce fluid properties for the simple problem of steady and transient shear flow.

  7. Hidden Degeneracies in Piecewise Smooth Dynamical Systems

    Science.gov (United States)

    Jeffrey, Mike R.

    When a flow suffers a discontinuity in its vector field at some switching surface, the flow can cross through or slide along the surface. Sliding along the switching surface can be understood as the flow along an invariant manifold inside a switching layer. It turns out that the usual method for finding sliding modes — the Filippov convex combination or Utkin equivalent control — results in a degeneracy in the switching layer whenever the flow is tangent to the switching surface from both sides. We derive the general result and analyze the simplest case here, where the flow curves parabolically on either side of the switching surface (the so-called fold-fold or two-fold singularities). The result is a set of zeros of the fast switching flow inside the layer, which is structurally unstable to perturbation by terms nonlinear in the switching parameter, terms such as (signx)2 [where the superscript does mean “squared”]. We provide structurally stable forms, and show that in this form the layer system is equivalent to a generic singularity of a two timescale system. Finally we show that the same degeneracy arises when a discontinuity is smoothed using standard regularization methods.

  8. Very Smooth Points of Spaces of Operators

    Indian Academy of Sciences (India)

    T S S R K Rao

    2003-02-01

    In this paper we study very smooth points of Banach spaces with special emphasis on spaces of operators. We show that when the space of compact operators is an -ideal in the space of bounded operators, a very smooth operator attains its norm at a unique vector (up to a constant multiple) and ( ) is a very smooth point of the range space. We show that if for every equivalent norm on a Banach space, the dual unit ball has a very smooth point then the space has the Radon–Nikodým property. We give an example of a smooth Banach space without any very smooth points.

  9. Smooth extrapolation of unknown anatomy via statistical shape models

    Science.gov (United States)

    Grupp, R. B.; Chiang, H.; Otake, Y.; Murphy, R. J.; Gordon, C. R.; Armand, M.; Taylor, R. H.

    2015-03-01

    Several methods to perform extrapolation of unknown anatomy were evaluated. The primary application is to enhance surgical procedures that may use partial medical images or medical images of incomplete anatomy. Le Fort-based, face-jaw-teeth transplant is one such procedure. From CT data of 36 skulls and 21 mandibles separate Statistical Shape Models of the anatomical surfaces were created. Using the Statistical Shape Models, incomplete surfaces were projected to obtain complete surface estimates. The surface estimates exhibit non-zero error in regions where the true surface is known; it is desirable to keep the true surface and seamlessly merge the estimated unknown surface. Existing extrapolation techniques produce non-smooth transitions from the true surface to the estimated surface, resulting in additional error and a less aesthetically pleasing result. The three extrapolation techniques evaluated were: copying and pasting of the surface estimate (non-smooth baseline), a feathering between the patient surface and surface estimate, and an estimate generated via a Thin Plate Spline trained from displacements between the surface estimate and corresponding vertices of the known patient surface. Feathering and Thin Plate Spline approaches both yielded smooth transitions. However, feathering corrupted known vertex values. Leave-one-out analyses were conducted, with 5% to 50% of known anatomy removed from the left-out patient and estimated via the proposed approaches. The Thin Plate Spline approach yielded smaller errors than the other two approaches, with an average vertex error improvement of 1.46 mm and 1.38 mm for the skull and mandible respectively, over the baseline approach.

  10. Remaining Life Expectancy With and Without Polypharmacy

    DEFF Research Database (Denmark)

    Wastesson, Jonas W; Canudas-Romo, Vladimir; Lindahl-Jacobsen, Rune

    2016-01-01

    OBJECTIVES: To investigate the remaining life expectancy with and without polypharmacy for Swedish women and men aged 65 years and older. DESIGN: Age-specific prevalence of polypharmacy from the nationwide Swedish Prescribed Drug Register (SPDR) combined with life tables from Statistics Sweden...... was used to calculate the survival function and remaining life expectancy with and without polypharmacy according to the Sullivan method. SETTING: Nationwide register-based study. PARTICIPANTS: A total of 1,347,564 individuals aged 65 years and older who had been prescribed and dispensed a drug from July 1...... to September 30, 2008. MEASUREMENTS: Polypharmacy was defined as the concurrent use of 5 or more drugs. RESULTS: At age 65 years, approximately 8 years of the 20 remaining years of life (41%) can be expected to be lived with polypharmacy. More than half of the remaining life expectancy will be spent...

  11. Regulation of human airway smooth muscle cell migration and relevance to asthma.

    Science.gov (United States)

    Salter, Brittany; Pray, Cara; Radford, Katherine; Martin, James G; Nair, Parameswaran

    2017-08-16

    Airway remodelling is an important feature of asthma pathogenesis. A key structural change inherent in airway remodelling is increased airway smooth muscle mass. There is emerging evidence to suggest that the migration of airway smooth muscle cells may contribute to cellular hyperplasia, and thus increased airway smooth muscle mass. The precise source of these cells remains unknown. Increased airway smooth muscle mass may be collectively due to airway infiltration of myofibroblasts, neighbouring airway smooth muscle cells in the bundle, or circulating hemopoietic progenitor cells. However, the relative contribution of each cell type is not well understood. In addition, although many studies have identified pro and anti-migratory agents of airway smooth muscle cells, whether these agents can impact airway remodelling in the context of human asthma, remains to be elucidated. As such, further research is required to determine the exact mechanism behind airway smooth muscle cell migration within the airways, how much this contributes to airway smooth muscle mass in asthma, and whether attenuating this migration may provide a therapeutic avenue for asthma. In this review article, we will discuss the current evidence with respect to the regulation of airway smooth muscle cell migration in asthma.

  12. Isotropic Growth of Graphene toward Smoothing Stitching.

    Science.gov (United States)

    Zeng, Mengqi; Tan, Lifang; Wang, Lingxiang; Mendes, Rafael G; Qin, Zhihui; Huang, Yaxin; Zhang, Tao; Fang, Liwen; Zhang, Yanfeng; Yue, Shuanglin; Rümmeli, Mark H; Peng, Lianmao; Liu, Zhongfan; Chen, Shengli; Fu, Lei

    2016-07-26

    The quality of graphene grown via chemical vapor deposition still has very great disparity with its theoretical property due to the inevitable formation of grain boundaries. The design of single-crystal substrate with an anisotropic twofold symmetry for the unidirectional alignment of graphene seeds would be a promising way for eliminating the grain boundaries at the wafer scale. However, such a delicate process will be easily terminated by the obstruction of defects or impurities. Here we investigated the isotropic growth behavior of graphene single crystals via melting the growth substrate to obtain an amorphous isotropic surface, which will not offer any specific grain orientation induction or preponderant growth rate toward a certain direction in the graphene growth process. The as-obtained graphene grains are isotropically round with mixed edges that exhibit high activity. The orientation of adjacent grains can be easily self-adjusted to smoothly match each other over a liquid catalyst with facile atom delocalization due to the low rotation steric hindrance of the isotropic grains, thus achieving the smoothing stitching of the adjacent graphene. Therefore, the adverse effects of grain boundaries will be eliminated and the excellent transport performance of graphene will be more guaranteed. What is more, such an isotropic growth mode can be extended to other types of layered nanomaterials such as hexagonal boron nitride and transition metal chalcogenides for obtaining large-size intrinsic film with low defect.

  13. Maximal right smooth extension chains

    CERN Document Server

    Huang, Yun Bao

    2010-01-01

    If $w=u\\alpha$ for $\\alpha\\in \\Sigma=\\{1,2\\}$ and $u\\in \\Sigma^*$, then $w$ is said to be a \\textit{simple right extension}of $u$ and denoted by $u\\prec w$. Let $k$ be a positive integer and $P^k(\\epsilon)$ denote the set of all $C^\\infty$-words of height $k$. Set $u_{1},\\,u_{2},..., u_{m}\\in P^{k}(\\epsilon)$, if $u_{1}\\prec u_{2}\\prec ...\\prec u_{m}$ and there is no element $v$ of $P^{k}(\\epsilon)$ such that $v\\prec u_{1}\\text{or} u_{m}\\prec v$, then $u_{1}\\prec u_{2}\\prec...\\prec u_{m}$ is said to be a \\textit{maximal right smooth extension (MRSE) chains}of height $k$. In this paper, we show that \\textit{MRSE} chains of height $k$ constitutes a partition of smooth words of height $k$ and give the formula of the number of \\textit{MRSE} chains of height $k$ for each positive integer $k$. Moreover, since there exist the minimal height $h_1$ and maximal height $h_2$ of smooth words of length $n$ for each positive integer $n$, we find that \\textit{MRSE} chains of heights $h_1-1$ and $h_2+1$ are good candidates t...

  14. 基于光学相干断层成像量化评估平滑面早期牙釉质龋的研究进展%Research advances in quantitative assessment of early enamel caries on the smooth surface based on optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    李燕妮; 姚晖

    2011-01-01

    BACKGROUND: Early enamel caries on the smooth surface is the subsurface demineralization limited in the enamel with anintact surface. It is difficult for routine clinical methods to make a definite diagnosis of early caries.OBJECTIVE: To summarize the histological characteristics and detecting methods of early enamel caries on the smooth surface,and the progress of quantitative assessment by optical coherence tomography.METHODS: Literatures about quantitative assessment of early caries on the smooth surface based on optical coherencetomography from CNKI and EBSCO HOST databases published from 1979 to 2011 were searched by the first author. The keywords were “optical coherence tomography, early caries, smooth surface, quantitative assessment” both in English and Chinese.Papers published recently or in authoritative journals were selected. Totally 78 documents were initially searched and 31 includedin this review.RESULTS AND CONCLUSION: The new technology, optical coherence tomography, which can image the demineralized enamelthrough detecting the back scatter signals and quantify early enamel caries with the parameters such as depth, reflectivity andattenuation coefficient, provides a new evidence to the diagnosis of early enamel caries.%背景:平滑面早期牙釉质龋虽然已发生脱矿改变但无肉眼可见的龋洞形成,目前临床采用的常规检测方法难以对其准确诊断.目的:应用光学相干断层成像技术对平滑面早期牙釉质龋的量化研究进展进行综述.方法:由第一作者检索CNKI和EBSCO HOST数据库中1979/2011发表的关于光学相干断层成像技术定量研究平滑面早期龋的相关文献,以"光学相干断层成像,早期龋,平滑面,量化评估"和"optical coherence tomography,early caries,smooth surface,quantitative assessment"为检索词进行检索.纳入31篇进行综述.结果与结论:新兴的光学相干断层成像技术能够检测龋变牙釉质的背向散射信号使脱矿牙釉

  15. Pharmacology of airway smooth muscle proliferation

    NARCIS (Netherlands)

    Gosens, Reinoud; Roscioni, Sara S.; Dekkers, Bart G. J.; Pera, Tonio; Schmidt, Martina; Schaafsma, Dedmer; Zaagsma, Johan; Meurs, Herman

    2008-01-01

    Airway smooth muscle thickening is a pathological feature that contributes significantly to airflow limitation and airway hyperresponsiveness in asthma. Ongoing research efforts aimed at identifying the mechanisms responsible for the increased airway smooth muscle mass have indicated that hyperplasi

  16. Smooth Optimization Approach for Sparse Covariance Selection

    OpenAIRE

    Lu, Zhaosong

    2009-01-01

    In this paper we first study a smooth optimization approach for solving a class of nonsmooth strictly concave maximization problems whose objective functions admit smooth convex minimization reformulations. In particular, we apply Nesterov's smooth optimization technique [Y.E. Nesterov, Dokl. Akad. Nauk SSSR, 269 (1983), pp. 543--547; Y. E. Nesterov, Math. Programming, 103 (2005), pp. 127--152] to their dual counterparts that are smooth convex problems. It is shown that the resulting approach...

  17. A SAS IML Macro for Loglinear Smoothing

    Science.gov (United States)

    Moses, Tim; von Davier, Alina

    2011-01-01

    Polynomial loglinear models for one-, two-, and higher-way contingency tables have important applications to measurement and assessment. They are essentially regarded as a smoothing technique, which is commonly referred to as loglinear smoothing. A SAS IML (SAS Institute, 2002a) macro was created to implement loglinear smoothing according to…

  18. Luminescence of thermally altered human skeletal remains.

    Science.gov (United States)

    Krap, Tristan; Nota, Kevin; Wilk, Leah S; van de Goot, Franklin R W; Ruijter, Jan M; Duijst, Wilma; Oostra, Roelof-Jan

    2017-07-01

    Literature on luminescent properties of thermally altered human remains is scarce and contradictory. Therefore, the luminescence of heated bone was systemically reinvestigated. A heating experiment was conducted on fresh human bone, in two different media, and cremated human remains were recovered from a modern crematory. Luminescence was excited with light sources within the range of 350 to 560 nm. The excitation light was filtered out by using different long pass filters, and the luminescence was analysed by means of a scoring method. The results show that temperature, duration and surrounding medium determine the observed emission intensity and bandwidth. It is concluded that the luminescent characteristic of bone can be useful for identifying thermally altered human remains in a difficult context as well as yield information on the perimortem and postmortem events.

  19. Influence of rough and smooth walls on macroscale granular segregation patterns

    Science.gov (United States)

    D'Ortona, Umberto; Thomas, Nathalie; Lueptow, Richard M.

    2016-02-01

    Size bidisperse granular materials in a spherical tumbler segregate into two different patterns of three bands with either small particles at the equator and large particles at the poles or vice versa, depending upon the fill level in the tumbler. Here we use discrete element method simulations with supporting qualitative experiments to explore the effect of the tumbler wall roughness on the segregation pattern, modeling the tumbler walls as either a closely packed monolayer of fixed particles resulting in a rough wall or a frictional geometrically smooth wall. Even though the tumbler wall is in contact with the flowing layer only at its periphery, the impact of wall roughness is profound. Smooth walls tend toward a small-large-small (SLS) band pattern at the pole-equator-pole at all but the highest fill fractions; rough walls tend toward a large-small-large (LSL) band pattern at all but the lowest fill fractions. This comes about because smooth walls induce poleward axial drift of small particles and an equator-directed drift for large particles, resulting in an SLS band pattern. On the other hand, rough walls result in both sizes of particles moving poleward at the surface of the flow. Due to radial segregation, small particles percolate lower in the flowing layer and when arriving near the pole are caught in the return current drift that carries them back toward the equator incrementally with each passage through the flowing layer, while large particles remain at the surface near the pole, resulting in an LSL band pattern. The tendency toward either of the two segregation patterns depends on the fill level in the tumbler and the roughness of the tumbler's bounding wall.

  20. A potential smoothing algorithm accurately predicts transmembrane helix packing.

    Science.gov (United States)

    Pappu, R V; Marshall, G R; Ponder, J W

    1999-01-01

    Potential smoothing, a deterministic analog of stochastic simulated annealing, is a powerful paradigm for the solution of conformational search problems that require extensive sampling, and should be a useful tool in computational approaches to structure prediction and refinement. A novel potential smoothing and search (PSS) algorithm has been developed and applied to predict the packing of transmembrane helices. The highlight of this method is the efficient manner in which it circumvents the combinatorial explosion associated with the large number of minima on multidimensional potential energy surfaces in order to converge to the global energy minimum. Here we show how our potential smoothing and search method succeeds in finding the global minimum energy structure for the glycophorin A (GpA) transmembrane helix dimer by optimizing interhelical van der Waals interactions over rigid and semi-rigid helices. Structures obtained from our ab initio predictions are in close agreement with recent experimental data.

  1. Fish remains and humankind: part two

    Directory of Open Access Journals (Sweden)

    Andrew K G Jones

    1998-07-01

    Full Text Available The significance of aquatic resources to past human groups is not adequately reflected in the published literature - a deficiency which is gradually being acknowledged by the archaeological community world-wide. The publication of the following three papers goes some way to redress this problem. Originally presented at an International Council of Archaeozoology (ICAZ Fish Remains Working Group meeting in York, U.K. in 1987, these papers offer clear evidence of the range of interest in ancient fish remains across the world. Further papers from the York meeting were published in Internet Archaeology 3 in 1997.

  2. Predicting the remaining service life of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, J.F.

    1991-11-01

    Nuclear power plants are providing, currently, about 17 percent of the U.S. electricity and many of these plants are approaching their licensed life of 40 years. The U.S. Nuclear Regulatory Commission and the Department of Energy`s Oak Ridge National Laboratory are carrying out a program to develop a methodology for assessing the remaining safe-life of the concrete components and structures in nuclear power plants. This program has the overall objective of identifying potential structural safety issues, as well as acceptance criteria, for use in evaluations of nuclear power plants for continued service. The National Institute of Standards and Technology (NIST) is contributing to this program by identifying and analyzing methods for predicting the remaining life of in-service concrete materials. This report examines the basis for predicting the remaining service lives of concrete materials of nuclear power facilities. Methods for predicting the service life of new and in-service concrete materials are analyzed. These methods include (1) estimates based on experience, (2) comparison of performance, (3) accelerated testing, (4) stochastic methods, and (5) mathematical modeling. New approaches for predicting the remaining service lives of concrete materials are proposed and recommendations for their further development given. Degradation processes are discussed based on considerations of their mechanisms, likelihood of occurrence, manifestations, and detection. They include corrosion, sulfate attack, alkali-aggregate reactions, frost attack, leaching, radiation, salt crystallization, and microbiological attack.

  3. Juveniles' Motivations for Remaining in Prostitution

    Science.gov (United States)

    Hwang, Shu-Ling; Bedford, Olwen

    2004-01-01

    Qualitative data from in-depth interviews were collected in 1990-1991, 1992, and 2000 with 49 prostituted juveniles remanded to two rehabilitation centers in Taiwan. These data are analyzed to explore Taiwanese prostituted juveniles' feelings about themselves and their work, their motivations for remaining in prostitution, and their difficulties…

  4. Identification of ancient remains through genomic sequencing

    Science.gov (United States)

    Blow, Matthew J.; Zhang, Tao; Woyke, Tanja; Speller, Camilla F.; Krivoshapkin, Andrei; Yang, Dongya Y.; Derevianko, Anatoly; Rubin, Edward M.

    2008-01-01

    Studies of ancient DNA have been hindered by the preciousness of remains, the small quantities of undamaged DNA accessible, and the limitations associated with conventional PCR amplification. In these studies, we developed and applied a genomewide adapter-mediated emulsion PCR amplification protocol for ancient mammalian samples estimated to be between 45,000 and 69,000 yr old. Using 454 Life Sciences (Roche) and Illumina sequencing (formerly Solexa sequencing) technologies, we examined over 100 megabases of DNA from amplified extracts, revealing unbiased sequence coverage with substantial amounts of nonredundant nuclear sequences from the sample sources and negligible levels of human contamination. We consistently recorded over 500-fold increases, such that nanogram quantities of starting material could be amplified to microgram quantities. Application of our protocol to a 50,000-yr-old uncharacterized bone sample that was unsuccessful in mitochondrial PCR provided sufficient nuclear sequences for comparison with extant mammals and subsequent phylogenetic classification of the remains. The combined use of emulsion PCR amplification and high-throughput sequencing allows for the generation of large quantities of DNA sequence data from ancient remains. Using such techniques, even small amounts of ancient remains with low levels of endogenous DNA preservation may yield substantial quantities of nuclear DNA, enabling novel applications of ancient DNA genomics to the investigation of extinct phyla. PMID:18426903

  5. Kadav Moun PSA (:60) (Human Remains)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about safety precautions for those handling human remains. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  6. The case for fencing remains intact.

    Science.gov (United States)

    Packer, C; Swanson, A; Canney, S; Loveridge, A; Garnett, S; Pfeifer, M; Burton, A C; Bauer, H; MacNulty, D

    2013-11-01

    Creel et al. argue against the conservation effectiveness of fencing based on a population measure that ignores the importance of top predators to ecosystem processes. Their statistical analyses consider, first, only a subset of fenced reserves and, second, an incomplete examination of 'costs per lion.' Our original conclusions remain unaltered.

  7. Removing the remaining ridges in fingerprint segmentation

    Institute of Scientific and Technical Information of China (English)

    ZHU En; ZHANG Jian-ming; YIN Jian-ping; ZHANG Guo-min; HU Chun-feng

    2006-01-01

    Fingerprint segmentation is an important step in fingerprint recognition and is usually aimed to identify non-ridge regions and unrecoverable low quality ridge regions and exclude them as background so as to reduce the time expenditure of image processing and avoid detecting false features. In high and in low quality ridge regions, often are some remaining ridges which are the afterimages of the previously scanned finger and are expected to be excluded from the foreground. However, existing segmentation methods generally do not take the case into consideration, and often, the remaining ridge regions are falsely classified as foreground by segmentation algorithm with spurious features produced erroneously including unrecoverable regions as foreground. This paper proposes two steps for fingerprint segmentation aimed at removing the remaining ridge region from the foreground. The non-ridge regions and unrecoverable low quality ridge regions are removed as background in the first step, and then the foreground produced by the first step is further analyzed for possible remove of the remaining ridge region. The proposed method proved effective in avoiding detecting false ridges and in improving minutiae detection.

  8. Why Agricultural Educators Remain in the Classroom

    Science.gov (United States)

    Crutchfield, Nina; Ritz, Rudy; Burris, Scott

    2013-01-01

    The purpose of this study was to identify and describe factors that are related to agricultural educator career retention and to explore the relationships between work engagement, work-life balance, occupational commitment, and personal and career factors as related to the decision to remain in the teaching profession. The target population for…

  9. Essential Qualities of Math Teaching Remain Unknown

    Science.gov (United States)

    Cavanagh, Sean

    2008-01-01

    According to a new federal report, the qualities of an effective mathematics teacher remain frustratingly elusive. The report of the National Mathematics Advisory Panel does not show what college math content and coursework are most essential for teachers. While the report offered numerous conclusions about math curriculum, cognition, and…

  10. Juveniles' Motivations for Remaining in Prostitution

    Science.gov (United States)

    Hwang, Shu-Ling; Bedford, Olwen

    2004-01-01

    Qualitative data from in-depth interviews were collected in 1990-1991, 1992, and 2000 with 49 prostituted juveniles remanded to two rehabilitation centers in Taiwan. These data are analyzed to explore Taiwanese prostituted juveniles' feelings about themselves and their work, their motivations for remaining in prostitution, and their difficulties…

  11. Smoothing of Piecewise Linear Paths

    Directory of Open Access Journals (Sweden)

    Michel Waringo

    2008-11-01

    Full Text Available We present an anytime-capable fast deterministic greedy algorithm for smoothing piecewise linear paths consisting of connected linear segments. With this method, path points with only a small influence on path geometry (i.e. aligned or nearly aligned points are successively removed. Due to the removal of less important path points, the computational and memory requirements of the paths are reduced and traversing the path is accelerated. Our algorithm can be used in many different applications, e.g. sweeping, path finding, programming-by-demonstration in a virtual environment, or 6D CNC milling. The algorithm handles points with positional and orientational coordinates of arbitrary dimension.

  12. Income and Consumption Smoothing among US States

    DEFF Research Database (Denmark)

    Sørensen, Bent; Yosha, Oved

    states. The fraction of a shock to gross state products smoothed by the federal tax-transfer system is the same for various regions and other clubs of states. We calculate the scope for consumption smoothing within various regions and clubs, finding that most gains from risk sharing can be achieved......We quantify the amount of cross-sectional income and consumption smoothing achieved within subgroups of states, such as regions or clubs, e.g. the club of rich states. We find that there is much income smoothing between as well as within regions. By contrast, consumption smoothing occurs mainly...... within regions but not between regions. This suggests that capital markets transcend regional barriers while credit markets are regional in their nature. Smoothing within the club of rich states is accomplished mainly via capital markets whereas consumption smoothing is dominant within the club of poor...

  13. Remaining Phosphorus Estimate Through Multiple Regression Analysis

    Institute of Scientific and Technical Information of China (English)

    M. E. ALVES; A. LAVORENTI

    2006-01-01

    The remaining phosphorus (Prem), P concentration that remains in solution after shaking soil with 0.01 mol L-1 CaCl2 containing 60 μg mL-1 P, is a very useful index for studies related to the chemistry of variable charge soils. Although the Prem determination is a simple procedure, the possibility of estimating accurate values of this index from easily and/or routinely determined soil properties can be very useful for practical purposes. The present research evaluated the Premestimation through multiple regression analysis in which routinely determined soil chemical data, soil clay content and soil pH measured in 1 mol L-1 NaF (pHNaF) figured as Prem predictor variables. The Prem can be estimated with acceptable accuracy using the above-mentioned approach, and PHNaF not only substitutes for clay content as a predictor variable but also confers more accuracy to the Prem estimates.

  14. Contact allergy to rubber accelerators remains prevalent

    DEFF Research Database (Denmark)

    Schwensen, J F; Menné, T; Johansen, J D

    2016-01-01

    INTRODUCTION: Chemicals used for the manufacturing of rubber are known causes of allergic contact dermatitis on the hands. Recent European studies have suggested a decrease in thiuram contact allergy. Moreover, while an association with hand dermatitis is well established, we have recently observ.......2% (19/54) and 35.4% (17/48) of the cases respectively. CONCLUSION: Contact allergy to rubber accelerators remains prevalent. Clinicians should be aware of the hitherto unexplored clinical association with facial dermatitis....

  15. [Professional confidentiality: speak out or remain silent? ].

    Science.gov (United States)

    Daubigney, Jean-claude

    2014-01-01

    People who work with children, in their daily tasks, must choose whether to disclose information entrusted to them. However, they are subject to the law, which authorises or imposes speaking out or remaining silent. In terms of ethics, they can seek the best possible response while respecting professional secrecy when meeting an individual, in a situation, in a place or at a particular time. They must then take responsibility for that decision.

  16. Terminology for houses and house remains

    OpenAIRE

    Rosberg, Karin

    2013-01-01

    In order to obtain lucidity, it is essential to choose adequate terminology when speaking of prehistoric houses. The understanding of house construction requires a terminology with a focus on construction. Very often, archaeologists instead use a terminology with a focus on the remains, and use an inadequate terminology for constructions, indicating that they do not fully consider how the constructions work. The article presents some suggestions for adequate construction terminology.

  17. Why do some cores remain starless ?

    CERN Document Server

    Anathpindika, S

    2016-01-01

    Physical conditions that could render a core starless(in the local Universe) is the subject of investigation in this work. To this end we studied the evolution of four starless cores, B68, L694-2, L1517B, L1689, and L1521F, a VeLLO. The density profile of a typical core extracted from an earlier simulation developed to study core-formation in a molecular cloud was used for the purpose. We demonstrate - (i) cores contracted in quasistatic manner over a timescale on the order of $\\sim 10^{5}$ years. Those that remained starless did briefly acquire a centrally concentrated density configuration that mimicked the density profile of a unstable Bonnor Ebert sphere before rebounding, (ii) three of our test cores viz. L694-2, L1689-SMM16 and L1521F remained starless despite becoming thermally super-critical. On the contrary B68 and L1517B remained sub-critical; L1521F collapsed to become a VeLLO only when gas-cooling was enhanced by increasing the size of dust-grains. This result is robust, for other cores viz. B68, ...

  18. The transcription factor TEAD1 represses smooth muscle-specific gene expression by abolishing myocardin function.

    Science.gov (United States)

    Liu, Fang; Wang, Xiaobo; Hu, Guoqing; Wang, Yong; Zhou, Jiliang

    2014-02-07

    The TEAD (transcriptional enhancer activator domain) proteins share an evolutionarily conserved DNA-binding TEA domain, which binds to the MCAT cis-acting regulatory element. Previous studies have shown that TEAD proteins are involved in regulating the expression of smooth muscle α-actin. However, it remains undetermined whether TEAD proteins play a broader role in regulating expression of other genes in vascular smooth muscle cells. In this study, we show that the expression of TEAD1 is significantly induced during smooth muscle cell phenotypic modulation and negatively correlates with smooth muscle-specific gene expression. We further demonstrate that TEAD1 plays a novel role in suppressing expression of smooth muscle-specific genes, including smooth muscle α-actin, by abolishing the promyogenic function of myocardin, a key mediator of smooth muscle differentiation. Mechanistically, we found that TEAD1 competes with myocardin for binding to serum response factor (SRF), resulting in disruption of myocardin and SRF interactions and thereby attenuating expression of smooth muscle-specific genes. This study provides the first evidence demonstrating that TEAD1 is a novel general repressor of smooth muscle-specific gene expression through interfering with myocardin binding to SRF.

  19. Finishing aeronautical planetary herringbone gear wheels in container vibrating smoothing machine

    Directory of Open Access Journals (Sweden)

    Jacek MICHALSKI

    2015-12-01

    Full Text Available The paper presents the technological process of abrasive-chemical machining wheel bearing surface of the cylindrical herringbone gears planetary gear in vibrating container smoothing machine according to Isotropic Finishing ISF® technology of the REM Chemicals Inc. company. Gear wheels are made of stainless Pyrowear 53 and subjected to carburizing, hardening, cold working and low tempering. The change in value of deviation indicators for the kinematic accuracy, smoothness and geometric structure of the machined surfaces of the gear teeth after smoothing compared with the contoured grinding were analyzed. The findings are different a characteristic performance on the surface of the tooth side along the outline, especially with a higher value at the head of the tooths. This creates a need for appropriate modification of the lateral surface of the teeth in the process of contoured grinding. The results of the mechanical strength of the samples gear wheel after the smoothing process and evaluating the hydrogen embrittlement are presented.

  20. Distribution of albatross remains in the Far East regions during the Holocene, based on zooarchaeological remains.

    Science.gov (United States)

    Eda, Masaki; Higuchi, Hiroyoshi

    2004-07-01

    Many albatross remains have been found in the Japanese Islands and the surrounding areas, such as Sakhalin and South Korea. These remains are interesting for two reasons: numerous sites from which albatross remains have been found are located in coastal regions of the Far East where no albatrosses have been distributed recently, and there are some sites in which albatross remains represent a large portion of avian remains, although albatrosses are not easily preyed upon by human beings. We collected data on albatross remains from archaeological sites in the Far East regions during the Holocene and arranged the remains geographically, temporally and in terms of quantity. Based on these results, we showed that coastal areas along the Seas of Okhotsk and Japan have rarely been used by albatrosses in Modern times, though formerly there were many albatrosses. We proposed two explanations for the shrinkage of their distributional range: excessive hunting in the breeding areas, and distributional changes of prey for albatrosses.

  1. Dual conformal transformations of smooth holographic Wilson loops

    CERN Document Server

    Dekel, Amit

    2016-01-01

    We study dual conformal transformations of minimal area surfaces in $AdS_5 \\times S^5$ corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual space by means of T-duality, then we apply a conformal transformation and finally T-dualize back to the original space. The transformation maps between string solutions with different boundary contours. The boundary contours of the minimal surfaces are not mapped back to the AdS boundary, and the regularized area of the surface changes.

  2. So close: remaining challenges to eradicating polio.

    Science.gov (United States)

    Toole, Michael J

    2016-03-14

    The Global Polio Eradication Initiative, launched in 1988, is close to achieving its goal. In 2015, reported cases of wild poliovirus were limited to just two countries - Afghanistan and Pakistan. Africa has been polio-free for more than 18 months. Remaining barriers to global eradication include insecurity in areas such as Northwest Pakistan and Eastern and Southern Afghanistan, where polio cases continue to be reported. Hostility to vaccination is either based on extreme ideologies, such as in Pakistan, vaccination fatigue by parents whose children have received more than 15 doses, and misunderstandings about the vaccine's safety and effectiveness such as in Ukraine. A further challenge is continued circulation of vaccine-derived poliovirus in populations with low immunity, with 28 cases reported in 2015 in countries as diverse as Madagascar, Ukraine, Laos, and Myanmar. This paper summarizes the current epidemiology of wild and vaccine-derived poliovirus, and describes the remaining challenges to eradication and innovative approaches being taken to overcome them.

  3. Resolution of smooth group actions

    CERN Document Server

    Albin, Pierre

    2010-01-01

    A refined form of the `Folk Theorem' that a smooth action by a compact Lie group can be (canonically) resolved, by iterated blow up, to have unique isotropy type is proved in the context of manifolds with corners. This procedure is shown to capture the simultaneous resolution of all isotropy types in a `resolution structure' consisting of equivariant iterated fibrations of the boundary faces. This structure projects to give a similar resolution structure for the quotient. In particular these results apply to give a canonical resolution of the radial compactification, to a ball, of any finite dimensional representation of a compact Lie group; such resolutions of the normal action of the isotropy groups appear in the boundary fibers in the general case.

  4. Smooth ergodic theory for endomorphisms

    CERN Document Server

    Qian, Min; Zhu, Shu

    2009-01-01

    This volume presents a general smooth ergodic theory for deterministic dynamical systems generated by non-invertible endomorphisms, mainly concerning the relations between entropy, Lyapunov exponents and dimensions. The authors make extensive use of the combination of the inverse limit space technique and the techniques developed to tackle random dynamical systems. The most interesting results in this book are (1) the equivalence between the SRB property and Pesin’s entropy formula; (2) the generalized Ledrappier-Young entropy formula; (3) exact-dimensionality for weakly hyperbolic diffeomorphisms and for expanding maps. The proof of the exact-dimensionality for weakly hyperbolic diffeomorphisms seems more accessible than that of Barreira et al. It also inspires the authors to argue to what extent the famous Eckmann-Ruelle conjecture and many other classical results for diffeomorphisms and for flows hold true. After a careful reading of the book, one can systematically learn the Pesin theory for endomorphis...

  5. Learning Smooth Pattern Transformation Manifolds

    CERN Document Server

    Vural, Elif

    2011-01-01

    Manifold models provide low-dimensional representations that are useful for processing and analyzing data in a transformation-invariant way. In this paper, we study the problem of learning smooth pattern transformation manifolds from image sets that represent observations of geometrically transformed signals. In order to construct a manifold, we build a representative pattern whose transformations accurately fit various input images. We examine two objectives of the manifold building problem, namely, approximation and classification. For the approximation problem, we propose a greedy method that constructs a representative pattern by selecting analytic atoms from a continuous dictionary manifold. We present a DC (Difference-of-Convex) optimization scheme that is applicable to a wide range of transformation and dictionary models, and demonstrate its application to transformation manifolds generated by rotation, translation and anisotropic scaling of a reference pattern. Then, we generalize this approach to a s...

  6. Smooth halos in the cosmic web

    CERN Document Server

    Gaite, Jose

    2014-01-01

    Dark matter halos can be defined as smooth distributions of dark matter placed in a non-smooth cosmic web structure. This definition of halos demands a precise definition of smoothness and a characterization of the manner in which the transition from smooth halos to the cosmic web takes place. We introduce entropic measures of smoothness, related to measures of equality previously used in economy and with the advantage of being connected with standard methods of multifractal analysis already used for characterizing the cosmic web structure in $N$-body simulations. These entropic measures provide us with a quantitative description of the transition from the small scales portrayed as a distribution of halos to the larger scales portrayed as a cosmic web and, therefore, allow us to assign definite sizes to halos. However, these "smoothness sizes" have no direct relation to the virial radii.

  7. Smooth GERBS, orthogonal systems and energy minimization

    Science.gov (United States)

    Dechevsky, Lubomir T.; Zanaty, Peter

    2013-12-01

    New results are obtained in three mutually related directions of the rapidly developing theory of generalized expo-rational B-splines (GERBS) [7, 6]: closed-form computability of C∞-smooth GERBS in terms of elementary and special functions, Hermite interpolation and least-squares best approximation via smooth GERBS, energy minimizing properties of smooth GERBS similar to those of the classical cubic polynomial B-splines.

  8. Smooth Crossed Products of Rieffel's Deformations

    Science.gov (United States)

    Neshveyev, Sergey

    2014-03-01

    Assume is a Fréchet algebra equipped with a smooth isometric action of a vector group V, and consider Rieffel's deformation of . We construct an explicit isomorphism between the smooth crossed products and . When combined with the Elliott-Natsume-Nest isomorphism, this immediately implies that the periodic cyclic cohomology is invariant under deformation. Specializing to the case of smooth subalgebras of C*-algebras, we also get a simple proof of equivalence of Rieffel's and Kasprzak's approaches to deformation.

  9. Airway Epithelium Stimulates Smooth Muscle Proliferation

    OpenAIRE

    Malavia, Nikita K.; Raub, Christopher B.; Mahon, Sari B.; Brenner, Matthew; Reynold A Panettieri; George, Steven C.

    2009-01-01

    Communication between the airway epithelium and stroma is evident during embryogenesis, and both epithelial shedding and increased smooth muscle proliferation are features of airway remodeling. Hence, we hypothesized that after injury the airway epithelium could modulate airway smooth muscle proliferation. Fully differentiated primary normal human bronchial epithelial (NHBE) cells at an air–liquid interface were co-cultured with serum-deprived normal primary human airway smooth muscle cells (...

  10. Properties of the extremal infinite smooth words

    Directory of Open Access Journals (Sweden)

    Srecko Brlek

    2007-05-01

    Full Text Available Smooth words are connected to the Kolakoski sequence. We construct the maximal and the minimal infinite smooth words, with respect to the lexicographical order. The naive algorithm generating them is improved by using a reduction of the De Bruijn graph of their factors. We also study their Lyndon factorizations. Finally, we show that the minimal smooth word over the alphabet {1,3} belongs to the orbit of the Fibonacci word.

  11. Does hypertension remain after kidney transplantation?

    Directory of Open Access Journals (Sweden)

    Gholamreza Pourmand

    2015-05-01

    Full Text Available Hypertension is a common complication of kidney transplantation with the prevalence of 80%. Studies in adults have shown a high prevalence of hypertension (HTN in the first three months of transplantation while this rate is reduced to 50- 60% at the end of the first year. HTN remains as a major risk factor for cardiovascular diseases, lower graft survival rates and poor function of transplanted kidney in adults and children. In this retrospective study, medical records of 400 kidney transplantation patients of Sina Hospital were evaluated. Patients were followed monthly for the 1st year, every two months in the 2nd year and every three months after that. In this study 244 (61% patients were male. Mean ± SD age of recipients was 39.3 ± 13.8 years. In most patients (40.8% the cause of end-stage renal disease (ESRD was unknown followed by HTN (26.3%. A total of 166 (41.5% patients had been hypertensive before transplantation and 234 (58.5% had normal blood pressure. Among these 234 individuals, 94 (40.2% developed post-transplantation HTN. On the other hand, among 166 pre-transplant hypertensive patients, 86 patients (56.8% remained hypertensive after transplantation. Totally 180 (45% patients had post-transplantation HTN and 220 patients (55% didn't develop HTN. Based on the findings, the incidence of post-transplantation hypertension is high, and kidney transplantation does not lead to remission of hypertension. On the other hand, hypertension is one of the main causes of ESRD. Thus, early screening of hypertension can prevent kidney damage and reduce further problems in renal transplant recipients.

  12. Heat transfer of smooth and finned tubes in A CFBC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.H. [Korea Electric Power Research Institute, Taejeon (Korea); Cho, H.H. [Yonsei University, Seoul (Korea)

    2000-11-01

    The objective of present work is to investigate experimentally the characteristics of heat transfer. A fluidized bed combustion has advantages of pollution control, fuel flexibility and excellent heat transfer. The present study investigates fundamental phenomena of bed-to-surface heat transfer in high temperature fluidized beds to improve design of immersed tube surface. The tested operating variables are bed temperature, superficial velocity, mean size of bed material, and the rake angle of fin. Generally, heat transfer rates between the fluidized bed and immersed finned-tube are much higher than those of a smooth tube. A life time of finned-tube is generally longer than that of smooth tube. (author). 4 figs.

  13. Smoothing techniques for macromolecular global optimization

    Energy Technology Data Exchange (ETDEWEB)

    More, J.J.; Wu, Zhijun

    1995-09-01

    We study global optimization problems that arise in macromolecular modeling, and the solution of these problems via continuation and smoothing. Our results unify and extend the theory associated with the use of the Gaussian transform for smoothing. We show that the, Gaussian transform can be viewed as a special case of a generalized transform and that these generalized transforms share many of the properties of the Gaussian transform. We also show that the smoothing behavior of the generalized transform can be studied in terms of the Fourier transform and that these results indicate that the Gaussian transform has superior smoothing properties.

  14. Molecular dynamics simulation of wetting on modified amorphous silica surface

    Science.gov (United States)

    Chai, Jingchun; Liu, Shuyan; Yang, Xiaoning

    2009-08-01

    The microscopic wetting of water on amorphous silica surfaces has been investigated by molecular dynamics simulation. Different degrees of surface hydroxylation/silanization were considered. It was observed that the hydrophobicity becomes enhanced with an increase in the degree of surface silanization. A continuous transformation from hydrophilicity to hydrophobicity can be attained for the amorphous silica surfaces through surface modification. From the simulation result, the contact angle can exceed 90° when surface silanization percentage is above 50%, showing a hydrophobic character. It is also found that when the percentage of surface silanization is above 70% on the amorphous silica surface, the water contact angle almost remains unchanged (110-120°). This phenomenon is a little different from the wetting behavior on smooth quartz plates in previous experimental report. This change in the wettability on modified amorphous silica surfaces can be interpreted in terms of the interaction between water molecules and the silica surfaces.

  15. Smoothed Particle Hydrodynamic of Hydraulic Jumps in Spillways

    OpenAIRE

    Jonsson, Patrick

    2015-01-01

    This thesis focus on the complex natural phenomena of hydraulic jumps using the numerical method Smoothed Particle Hydrodynamics (SPH). A hydraulic jump is highly turbulent and associated with turbulent energy dissipation, air entrainment, surface waves and spray and strong dissipative processes. It can be found not only in natural streams and in engineered open channels, but also in your kitchen sink at home. The dissipative features are utilized in hydropower spillways and stilling basins t...

  16. Smoothed Particle Hydrodynamics Model for Reactive Transport and Mineral Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Tartakovsky, Alexandre M.; Scheibe, Timothy D.; Redden, George; Meakin, Paul; Fang, Yilin

    2006-06-30

    A new Lagrangian particle model based on smoothed particle hydrodynamics was used to simulate pore scale precipitation reactions. The side-by-side injection of reacting solutions into two halves of a two-dimensional granular porous medium was simulated. Precipitation on grain surfaces occurred along a narrow zone in the middle of the domain, where the reacting solutes mixed to generate a supersaturated reaction product. The numerical simulations qualitatively reproduced the behavior observed in related laboratory experiments.

  17. Geology of Smooth Ridge: MARS-IODP Cabled Observatory Site

    Science.gov (United States)

    Jordahl, K. A.; Paull, C. K.; Ussler, W.; Aiello, I. W.; Mitts, P.; Greene, H. G.; Gibbs, S.

    2004-12-01

    cores, and ROV observations and sampling reveal that sediments have not been accumulating in the Holocene. Exposure of Plio-Pleistocene strata on the surface of Smooth Ridge in water depths of less than 1 km indicates that this is an area of active seafloor erosion. Measurements of sulfate gradients in piston cores indicate sulfate depletion occurs between 3 to 5 m below the seafloor, which is unusually shallow for continental margin sediments and suggests enhanced biogeochemical/microbiological activity occurs in the subsurface under Smooth Ridge.

  18. "Recent" macrofossil remains from the Lomonosov Ridge, central Arctic Ocean

    Science.gov (United States)

    Le Duc, Cynthia; de Vernal, Anne; Archambault, Philippe; Brice, Camille; Roberge, Philippe

    2016-04-01

    The examination of surface sediment samples collected from 17 sites along the Lomonosov Ridge at water depths ranging from 737 to 3339 meters during Polarstern Expedition PS87 in 2014 (Stein, 2015), indicates a rich biogenic content almost exclusively dominated by calcareous remains. Amongst biogenic remains, microfossils (planktic and benthic foraminifers, pteropods, ostracods, etc.) dominate but millimetric to centrimetric macrofossils occurred frequently at the surface of the sediment. The macrofossil remains consist of a large variety of taxa, including gastropods, bivalvia, polychaete tubes, scaphopods, echinoderm plates and spines, and fish otoliths. Among the Bivalvia, the most abundant taxa are Portlandia arctica, Hyalopecten frigidus, Cuspidaria glacilis, Policordia densicostata, Bathyarca spp., and Yoldiella spp. Whereas a few specimens are well preserved and apparently pristine, most mollusk shells displayed extensive alteration features. Moreover, most shells were covered by millimeter scale tubes of the serpulid polychaete Spirorbis sp. suggesting transport from low intertidal or subtidal zone. Both the ecological affinity and known geographic distribution of identified bivalvia as named above support the hypothesis of transportation rather than local development. In addition to mollusk shells, more than a hundred fish otoliths were recovered in surface sediments. The otoliths mostly belong to the Gadidae family. Most of them are well preserved and without serpulid tubes attached to their surface, suggesting a local/regional origin, unlike the shell remains. Although recovered at the surface, the macrofaunal assemblages of the Lomonosov Ridge do not necessarily represent the "modern" environments as they may result from reworking and because their occurrence at the surface of the sediment may also be due to winnowing of finer particles. Although the shells were not dated, we suspect that their actual ages may range from modern to several thousands of

  19. Recovery of human remains after shark attack.

    Science.gov (United States)

    Byard, Roger W; James, Ross A; Heath, Karen J

    2006-09-01

    Two cases of fatal shark attack are reported where the only tissues recovered were fragments of lung. Case 1: An 18-year-old male who was in the sea behind a boat was observed by friends to be taken by a great white shark (Carcharodon carcharias). The shark dragged him under the water and then, with a second shark, dismembered the body. Witnesses noted a large amount of blood and unrecognizable body parts coming to the surface. The only tissues recovered despite an intensive beach and sea search were 2 fragments of lung. Case 2: A 19-year-old male was attacked by a great white shark while diving. A witness saw the shark swim away with the victim's body in its mouth. Again, despite intensive beach and sea searches, the only tissue recovered was a single piece of lung, along with pieces of wetsuit and diving equipment. These cases indicate that the only tissue to escape being consumed or lost in fatal shark attacks, where there is a significant attack with dismemberment and disruption of the integrity of the body, may be lung. The buoyancy of aerated pulmonary tissue ensures that it rises quickly to the surface, where it may be recovered by searchers soon after the attack. Aeration of the lung would be in keeping with death from trauma rather than from drowning and may be a useful marker in unwitnessed deaths to separate ante- from postmortem injury, using only relatively small amounts of tissues. Early organ recovery enhances the identification of human tissues as the extent of morphologic alterations by putrefactive processes and sea scavengers will have been minimized. DNA testing is also possible on such recovered fragments, enabling confirmation of the identity of the victim.

  20. Remaining Useful Lifetime (RUL - Probabilistic Predictive Model

    Directory of Open Access Journals (Sweden)

    Ephraim Suhir

    2011-01-01

    Full Text Available Reliability evaluations and assurances cannot be delayed until the device (system is fabricated and put into operation. Reliability of an electronic product should be conceived at the early stages of its design; implemented during manufacturing; evaluated (considering customer requirements and the existing specifications, by electrical, optical and mechanical measurements and testing; checked (screened during manufacturing (fabrication; and, if necessary and appropriate, maintained in the field during the product’s operation Simple and physically meaningful probabilistic predictive model is suggested for the evaluation of the remaining useful lifetime (RUL of an electronic device (system after an appreciable deviation from its normal operation conditions has been detected, and the increase in the failure rate and the change in the configuration of the wear-out portion of the bathtub has been assessed. The general concepts are illustrated by numerical examples. The model can be employed, along with other PHM forecasting and interfering tools and means, to evaluate and to maintain the high level of the reliability (probability of non-failure of a device (system at the operation stage of its lifetime.

  1. The Human Remains from HMS Pandora

    Directory of Open Access Journals (Sweden)

    D.P. Steptoe

    2002-04-01

    Full Text Available In 1977 the wreck of HMS Pandora (the ship that was sent to re-capture the Bounty mutineers was discovered off the north coast of Queensland. Since 1983, the Queensland Museum Maritime Archaeology section has carried out systematic excavation of the wreck. During the years 1986 and 1995-1998, more than 200 human bone and bone fragments were recovered. Osteological investigation revealed that this material represented three males. Their ages were estimated at approximately 17 +/-2 years, 22 +/-3 years and 28 +/-4 years, with statures of 168 +/-4cm, 167 +/-4cm, and 166cm +/-3cm respectively. All three individuals were probably Caucasian, although precise determination of ethnicity was not possible. In addition to poor dental hygiene, signs of chronic diseases suggestive of rickets and syphilis were observed. Evidence of spina bifida was seen on one of the skeletons, as were other skeletal anomalies. Various taphonomic processes affecting the remains were also observed and described. Compact bone was observed under the scanning electron microscope and found to be structurally coherent. Profiles of the three skeletons were compared with historical information about the 35 men lost with the ship, but no precise identification could be made. The investigation did not reveal the cause of death. Further research, such as DNA analysis, is being carried out at the time of publication.

  2. Smart Point Cloud: Definition and Remaining Challenges

    Science.gov (United States)

    Poux, F.; Hallot, P.; Neuville, R.; Billen, R.

    2016-10-01

    Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data) rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

  3. SMART POINT CLOUD: DEFINITION AND REMAINING CHALLENGES

    Directory of Open Access Journals (Sweden)

    F. Poux

    2016-10-01

    Full Text Available Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

  4. Turbidite plays` immaturity means big potential remains

    Energy Technology Data Exchange (ETDEWEB)

    Pettingill, H.S. [Repsol Exploracion SA, Madrid (Spain)

    1998-10-05

    The international exploration and production industry is increasingly focusing on deepwater plays. Turbidites are not the only reservoir type that occurs in deepwater frontiers, but they are the primary reservoir type of those plays. A worldwide data base assembled from published information on 925 fields and discoveries with deepwater clastic reservoirs (turbidites sensu lato) has been employed to investigate the large-scale exploration and production trends. Coverage of the Former Soviet Union, China, and the Indian subcontinent has been minor, but with the large data base of fields and discoveries from the rest of the world, the broad conclusions should remain valid. This article describes the global turbidite play in terms of: (1) basins of the world where turbidite fields have been discovered; (2) the five largest basins in terms of total discovered resources; and (3) a summary of trap type, which is a critical geological factor in turbidite fields. The second article will summarize a population of the world`s 43 largest turbidite fields and discoveries.

  5. Exotic smooth R^4, noncommutative algebras and quantization

    CERN Document Server

    Asselmeyer-Maluga, Torsten

    2010-01-01

    The paper shows deep connections between exotic smoothings of small R^4, noncommutative algebras of foliations and quantization. At first, based on the close relation of foliations and noncommutative C*-algebras we show that cyclic cohomology invariants characterize some small exotic R^4. Certain exotic smooth R^4's define a generalized embedding into a space which is K-theoretic equivalent to a noncommutative Banach algebra. Furthermore, we show that a factor III von Neumann algebra is naturally related with nonstandard smoothing of a small R^4 and conjecture that this factor is the unique hyperfinite factor III_1. We also show how an exotic smoothing of a small R^4 is related to the Drinfeld-Turaev (deformation) quantization of the Poisson algebra (X(S,SL(2,C),{,}) of complex functions on the space of flat connections X(S,SL(2,C) over a surface S, and that the result of this quantization is the skein algebra (K_t(S),[,]) for the deformation parameter t=exp(h/4). This skein algebra is retrieved as a II_1 fac...

  6. Avaliação dos efeitos de três métodos de remoção da resina remanescente do braquete na superfície do esmalte Effects evaluation of remaining resin removal (three modes on enamel surface after bracket debonding

    Directory of Open Access Journals (Sweden)

    Karine Macieski

    2011-10-01

    Full Text Available INTRODUÇÃO: é fundamental, para alcançar a correta técnica de descolagem, a seleção adequada do instrumental para remover o braquete e a resina remanescente. OBJETIVO: avaliar a superfície do esmalte com Microscópio Eletrônico de Varredura (MEV após a utilização de três métodos de remoção da resina remanescente da descolagem do braquete. MÉTODOS: foram selecionados 18 incisivos bovinos, divididos em três grupos (A, B e C, contendo 6 dentes cada. Previamente à colagem do braquete, os dentes foram moldados com silicone de adição e preenchidos com resina epóxi, para o registro das características do esmalte, assim formando o Grupo Controle. Os métodos de remoção da resina remanescente utilizados foram: Grupo A - Soflex granulações grossa e média; Grupo B - broca Carbide em baixa rotação; Grupo C - broca Carbide em alta rotação. Polimento com Soflex granulações fina e ultrafina no Grupo A, pontas de borracha nos grupos B e C, e pasta de polimento para esmalte nos três grupos. Após cada etapa de remoção da resina remanescente e polimento, os dentes foram novamente moldados, duplicados e as réplicas analisadas em MEV. Foram, então, comparadas as características do esmalte inicial (Grupo Controle com o aspecto do esmalte após as etapas de remoção de resina, assim possibilitando avaliar o método que gerou menor abrasão ao esmalte. RESULTADOS E CONCLUSÃO: a remoção do remanescente adesivo com broca Carbide multilaminada em baixa rotação, polimento com pontas de borracha, e polimento final com pasta de polimento é o procedimento que ocasiona menor dano ao esmalte.INTRODUCTION: To achieve the correct debonding technique, it's essential the appropriate instruments selection to remove the bracket and the remaining resin. OBJECTIVE: To evaluate the enamel surface in a Scanning Electron Microscope (SEM after the utilization of three methods for removing the remaining resin after debonding the bracket

  7. Remaining phosphorus estimated by pedotransfer function

    Directory of Open Access Journals (Sweden)

    Joice Cagliari

    2011-02-01

    Full Text Available Although the determination of remaining phosphorus (Prem is simple, accurate values could also be estimated with a pedotransfer function (PTF aiming at the additional use of soil analysis data and/or Prem replacement by an even simpler determination. The purpose of this paper was to develop a pedotransfer function to estimate Prem values of soils of the State of São Paulo based on properties with easier or routine laboratory determination. A pedotransfer function was developed by artificial neural networks (ANN from a database of Prem values, pH values measured in 1 mol L-1 NaF solution (pH NaF and soil chemical and physical properties of samples collected during soil classification activities carried out in the State of São Paulo by the Agronomic Institute of Campinas (IAC. Furthermore, a pedotransfer function was developed by regressing Prem values against the same predictor variables of the ANN-based PTF. Results showed that Prem values can be calculated more accurately with the ANN-based pedotransfer function with the input variables pH NaF values along with the sum of exchangeable bases (SB and the exchangeable aluminum (Al3+ soil content. In addition, the accuracy of the Prem estimates by ANN-based PTF were more sensitive to increases in the experimental database size. Although the database used in this study was not comprehensive enough for the establishment of a definitive pedotrasnfer function for Prem estimation, results indicated the inclusion of Prem and pH NaF measurements among the soil testing evaluations as promising ind order to provide a greater database for the development of an ANN-based pedotransfer function for accurate Prem estimates from pH NaF, SB, and Al3+ values.

  8. Ghost Remains After Black Hole Eruption

    Science.gov (United States)

    2009-05-01

    NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after

  9. Smooth horizons and quantum ripples

    CERN Document Server

    Golovnev, Alexey

    2014-01-01

    Black Holes are unique objects which allow for meaningful theoretical studies of strong gravity and even quantum gravity effects. An infalling and a distant observer would have very different views on the structure of the world. However, a careful analysis has shown that it entails no genuine contradictions for physics, and the paradigm of observer complementarity has been coined. Recently this picture was put into doubt. In particular, it was argued that in old Black Holes a firewall must form in order to protect the basic principles of quantum mechanics. This AMPS paradox has already been discussed in a vast number of papers with different attitudes and conclusions. Here we want to argue that a possible source of confusion is neglection of quantum gravity effects. Contrary to widespread perception, it does not necessarily mean that effective field theory is inapplicable in rather smooth neighbourhoods of large Black Hole horizons. The real offender might be an attempt to consistently use it over the huge di...

  10. Local Transfer Coefficient, Smooth Channel

    Directory of Open Access Journals (Sweden)

    R. T. Kukreja

    1998-01-01

    Full Text Available Naphthalene sublimation technique and the heat/mass transfer analogy are used to determine the detailed local heat/mass transfer distributions on the leading and trailing walls of a twopass square channel with smooth walls that rotates about a perpendicular axis. Since the variation of density is small in the flow through the channel, buoyancy effect is negligible. Results show that, in both the stationary and rotating channel cases, very large spanwise variations of the mass transfer exist in he turn and in the region immediately downstream of the turn in the second straight pass. In the first straight pass, the rotation-induced Coriolis forces reduce the mass transfer on the leading wall and increase the mass transfer on the trailing wall. In the turn, rotation significantly increases the mass transfer on the leading wall, especially in the upstream half of the turn. Rotation also increases the mass transfer on the trailing wall, more in the downstream half of the turn than in the upstream half of the turn. Immediately downstream of the turn, rotation causes the mass transfer to be much higher on the trailing wall near the downstream corner of the tip of the inner wall than on the opposite leading wall. The mass transfer in the second pass is higher on the leading wall than on the trailing wall. A slower flow causes higher mass transfer enhancement in the turn on both the leading and trailing walls.

  11. Smooth horizons and quantum ripples

    Energy Technology Data Exchange (ETDEWEB)

    Golovnev, Alexey [Saint Petersburg State University, High Energy Physics Department, Saint-Petersburg (Russian Federation)

    2015-05-15

    Black holes are unique objects which allow for meaningful theoretical studies of strong gravity and even quantum gravity effects. An infalling and a distant observer would have very different views on the structure of the world. However, a careful analysis has shown that it entails no genuine contradictions for physics, and the paradigm of observer complementarity has been coined. Recently this picture was put into doubt. In particular, it was argued that in old black holes a firewall must form in order to protect the basic principles of quantum mechanics. This AMPS paradox has already been discussed in a vast number of papers with different attitudes and conclusions. Here we want to argue that a possible source of confusion is the neglect of quantum gravity effects. Contrary to widespread perception, it does not necessarily mean that effective field theory is inapplicable in rather smooth neighbourhoods of large black hole horizons. The real offender might be an attempt to consistently use it over the huge distances from the near-horizon zone of old black holes to the early radiation. We give simple estimates to support this viewpoint and show how the Page time and (somewhat more speculative) scrambling time do appear. (orig.)

  12. Smoothed particle hydrodynamics and magnetohydrodynamics

    Science.gov (United States)

    Price, Daniel J.

    2012-02-01

    This paper presents an overview and introduction to smoothed particle hydrodynamics and magnetohydrodynamics in theory and in practice. Firstly, we give a basic grounding in the fundamentals of SPH, showing how the equations of motion and energy can be self-consistently derived from the density estimate. We then show how to interpret these equations using the basic SPH interpolation formulae and highlight the subtle difference in approach between SPH and other particle methods. In doing so, we also critique several 'urban myths' regarding SPH, in particular the idea that one can simply increase the 'neighbour number' more slowly than the total number of particles in order to obtain convergence. We also discuss the origin of numerical instabilities such as the pairing and tensile instabilities. Finally, we give practical advice on how to resolve three of the main issues with SPMHD: removing the tensile instability, formulating dissipative terms for MHD shocks and enforcing the divergence constraint on the particles, and we give the current status of developments in this area. Accompanying the paper is the first public release of the NDSPMHD SPH code, a 1, 2 and 3 dimensional code designed as a testbed for SPH/SPMHD algorithms that can be used to test many of the ideas and used to run all of the numerical examples contained in the paper.

  13. NDSPMHD Smoothed Particle Magnetohydrodynamics Code

    Science.gov (United States)

    Price, Daniel J.

    2011-01-01

    This paper presents an overview and introduction to Smoothed Particle Hydrodynamics and Magnetohydrodynamics in theory and in practice. Firstly, we give a basic grounding in the fundamentals of SPH, showing how the equations of motion and energy can be self-consistently derived from the density estimate. We then show how to interpret these equations using the basic SPH interpolation formulae and highlight the subtle difference in approach between SPH and other particle methods. In doing so, we also critique several 'urban myths' regarding SPH, in particular the idea that one can simply increase the 'neighbour number' more slowly than the total number of particles in order to obtain convergence. We also discuss the origin of numerical instabilities such as the pairing and tensile instabilities. Finally, we give practical advice on how to resolve three of the main issues with SPMHD: removing the tensile instability, formulating dissipative terms for MHD shocks and enforcing the divergence constraint on the particles, and we give the current status of developments in this area. Accompanying the paper is the first public release of the NDSPMHD SPH code, a 1, 2 and 3 dimensional code designed as a testbed for SPH/SPMHD algorithms that can be used to test many of the ideas and used to run all of the numerical examples contained in the paper.

  14. Strain history and TGF-β1 induce urinary bladder wall smooth muscle remodeling and elastogenesis

    OpenAIRE

    Heise, Rebecca L.; Parekh, Aron; Joyce, Erinn M.; Michael B. Chancellor; Sacks, Michael S.

    2011-01-01

    Mechanical cues that trigger pathological remodeling in smooth muscle tissues remain largely unknown and are thought to be pivotal triggers for strain-induced remodeling. Thus, an understanding of the effects mechanical stimulation is important to elucidate underlying mechanisms of disease states and in the development of methods for smooth muscle tissue regeneration. For example, the urinary bladder wall (UBW) adaptation to spinal cord injury (SCI) includes extensive hypertrophy as well as i...

  15. Smoothing a Piecewise-Smooth: An Example from Plankton Population Dynamics

    DEFF Research Database (Denmark)

    Piltz, Sofia Helena

    2016-01-01

    In this work we discuss a piecewise-smooth dynamical system inspired by plankton observations and constructed for one predator switching its diet between two different types of prey. We then discuss two smooth formulations of the piecewise-smooth model obtained by using a hyperbolic tangent...

  16. Smoothing the output from a DAC

    Science.gov (United States)

    Wagner, C.

    1980-01-01

    Circuit smooths stepped waveform from analog-to-digital converter without appreciable phase shift between stepped input signal and smoothed output signal and without any effect from stepping rate. Waveform produced is suitable for driving controls used in manufacturing processes, aerospace systems, and automobiles.

  17. Smoothed dynamics in the central field problem

    CERN Document Server

    Santoprete, Manuele

    2009-01-01

    Consider the motion of a material point of unit mass in a central field determined by a homogeneous potential of the form $(-1/r^{\\alpha})$, $\\alpha>0,$ where $r$ being the distance to the centre of the field. Due to the singularity at $r=0,$ in computer-based simulations, usually, the potential is replaced by a similar potential that is smooth, or at least continuous. In this paper, we compare the global flows given by the smoothed and non-smoothed potentials. It is shown that the two flows are topologically equivalent for $\\alpha < 2,$ while for $\\alpha \\geq 2,$ smoothing introduces fake orbits. Further, we argue that for $\\alpha\\geq 2,$ smoothing should be applied to the amended potential $c/(2r^2)-1/r^{\\alpha},$ where $c$ denotes the angular momentum constant.

  18. Cursive writing with smooth pursuit eye movements.

    Science.gov (United States)

    Lorenceau, Jean

    2012-08-21

    The eyes never cease to move: ballistic saccades quickly turn the gaze toward peripheral targets, whereas smooth pursuit maintains moving targets on the fovea where visual acuity is best. Despite the oculomotor system being endowed with exquisite motor abilities, any attempt to generate smooth eye movements against a static background results in saccadic eye movements. Although exceptions to this rule have been reported, volitional control over smooth eye movements is at best rudimentary. Here, I introduce a novel, temporally modulated visual display, which, although static, sustains smooth eye movements in arbitrary directions. After brief training, participants gain volitional control over smooth pursuit eye movements and can generate digits, letters, words, or drawings at will. For persons deprived of limb movement, this offers a fast, creative, and personal means of linguistic and emotional expression. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Improved Edge Awareness in Discontinuity Preserving Smoothing

    CERN Document Server

    Heinrich, Stuart B

    2011-01-01

    Discontinuity preserving smoothing is a fundamentally important procedure that is useful in a wide variety of image processing contexts. It is directly useful for noise reduction, and frequently used as an intermediate step in higher level algorithms. For example, it can be particularly useful in edge detection and segmentation. Three well known algorithms for discontinuity preserving smoothing are nonlinear anisotropic diffusion, bilateral filtering, and mean shift filtering. Although slight differences make them each better suited to different tasks, all are designed to preserve discontinuities while smoothing. However, none of them satisfy this goal perfectly: they each have exception cases in which smoothing may occur across hard edges. The principal contribution of this paper is the identification of a property we call edge awareness that should be satisfied by any discontinuity preserving smoothing algorithm. This constraint can be incorporated into existing algorithms to improve quality, and usually ha...

  20. A Smoothed Particle Hydrodynamics approach for poroelasticity

    Science.gov (United States)

    Osorno, Maria; Steeb, Holger

    2016-04-01

    Within the framework of the SHynergie project we look to investigate hydraulic fracturing and crack evolving in poroelastic media. We model biphasic media assuming incompressible solid grain and incompressible pore liquid. Modeling evolving fractures and fracture networks in elastic and poroelastic media by mesh-based numerical approaches, like X-FEM, is especially in 3-dim a challenging task. Therefore, we propose a meshless particle method for fractured media based on the Smoothed Particle Hydrodynamics (SPH) approach. SPH is a meshless Lagrangian method highly suitable for the simulation of large deformations including free surfaces and/or interfaces. Within the SPH method, the computational domain is discretized with particles, avoiding the computational expenses of meshing. Our SPH solution is implemented in a parallel computational framework, which allows to simulate large domains more representative of the scale of our study cases. Our implementation is carefully validated against classical mesh-based approaches and compared with classical solutions for consolidation problems. Furthermore, we discuss fracture initiation and propagation in poroelastic rocks at the reservoir scale.

  1. SMACK - SMOOTHING FOR AIRCRAFT KINEMATICS

    Science.gov (United States)

    Bach, R.

    1994-01-01

    The computer program SMACK (SMoothing for AirCraft Kinematics) is designed to provide flightpath reconstruction of aircraft forces and motions from measurements that are noisy or incomplete. Additionally, SMACK provides a check on instrument accuracy and data consistency. The program can be used to analyze data from flight-test experiments prior to their use in performance, stability and control, or aerodynamic modeling calculations. It can also be used in the analysis of aircraft accidents, where the actual forces and motions may have to be determined from a very limited data set. Application of a state-estimation method for flightpath reconstruction is possible because aircraft forces and motions are related by well-known equations of motion. The task of postflight state estimation is known as a nonlinear, fixed-interval smoothing problem. SMACK utilizes a backward-filter, forward-smoother algorithm to solve the problem. The equations of motion are used to produce estimates that are compared with their corresponding measurement time histories. The procedure is iterative, providing improved state estimates until a minimum squared-error measure is achieved. In the SMACK program, the state and measurement models together represent a finite-difference approximation for the six-degree-of-freedom dynamics of a rigid body. The models are used to generate time histories which are likely to be found in a flight-test measurement set. These include onboard variables such as Euler angles, angular rates, and linear accelerations as well as tracking variables such as slant range, bearing, and elevation. Any bias or scale-factor errors associated with the state or measurement models are appended to the state vector and treated as constant but unknown parameters. The SMACK documentation covers the derivation of the solution algorithm, describes the state and measurement models, and presents several application examples that should help the analyst recognize the potential

  2. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Shvydky, A.; Marozas, J. A.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road Rochester, Rochester, New York 14623 (United States); Fiksel, G. [Nuclear Engineering and Radiological Sciences (NERS), University of Michigan, Ann Arbor, Michigan 48109 (United States); Meyerhofer, D. D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-09-15

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ∼50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  3. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    Science.gov (United States)

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-01

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh-Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ˜50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  4. Theoretical effect of modifications to the upper surface of two NACA airfoils using smooth polynomial additional thickness distributions which emphasize leading edge profile and which vary quadratically at the trailing edge. [using flow equations and a CDC 7600 computer

    Science.gov (United States)

    Merz, A. W.; Hague, D. S.

    1975-01-01

    An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of the NACA 64-206 and 64 sub 1 - 212 airfoils. The additional thickness distribution had the form of a continuous mathematical function which disappears at both the leading edge and the trailing edge. The function behaves as a polynomial of order epsilon sub 1 at the leading edge, and a polynomial of order epsilon sub 2 at the trailing edge. Epsilon sub 2 is a constant and epsilon sub 1 is varied over a range of practical interest. The magnitude of the additional thickness, y, is a second input parameter, and the effect of varying epsilon sub 1 and y on the aerodynamic performance of the airfoil was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic airfoils, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.

  5. Approximation of Bivariate Functions via Smooth Extensions

    Science.gov (United States)

    Zhang, Zhihua

    2014-01-01

    For a smooth bivariate function defined on a general domain with arbitrary shape, it is difficult to do Fourier approximation or wavelet approximation. In order to solve these problems, in this paper, we give an extension of the bivariate function on a general domain with arbitrary shape to a smooth, periodic function in the whole space or to a smooth, compactly supported function in the whole space. These smooth extensions have simple and clear representations which are determined by this bivariate function and some polynomials. After that, we expand the smooth, periodic function into a Fourier series or a periodic wavelet series or we expand the smooth, compactly supported function into a wavelet series. Since our extensions are smooth, the obtained Fourier coefficients or wavelet coefficients decay very fast. Since our extension tools are polynomials, the moment theorem shows that a lot of wavelet coefficients vanish. From this, with the help of well-known approximation theorems, using our extension methods, the Fourier approximation and the wavelet approximation of the bivariate function on the general domain with small error are obtained. PMID:24683316

  6. Convective Heat-Transfer Characteristics of Laminar Flow Through Smooth- and Rough-Wall Microchannels

    Science.gov (United States)

    Natrajan, V. K.; Christensen, K. T.

    2009-11-01

    The convective heat-transfer behavior of laminar flow through smooth- and rough-wall microchannels is investigated by performing non-intrusive measurements of fluid temperature using a microscale adaptation of two-color laser-induced fluorescent thermometry for flow through a heated copper microchannel testbed of hydraulic diameter Dh=600,μm. These measurements, in concert with pressure-drop measurements, are performed for a smooth-wall case and two different rough-wall cases with roughness that is reminiscent of the surface irregularities one might encounter due to imperfect fabrication methods. Pressure-drop measurements reveal the onset of transition above Recr=1800 for the smooth-wall case and deviation from laminar behavior at progressively lower Re with increasing surface roughness. The local Nusselt number (Nu) for smooth-wall flow over the range 200flow.

  7. Multiple Liquid Bridges with Non-Smooth Interfaces

    CERN Document Server

    Fel, Leonid; Ratner, Vadim

    2015-01-01

    We consider a coexistence of two axisymmetric liquid bridges LB_i and LB_m of two immiscible liquids i and m which are immersed in a third liquid (or gas) e and trapped between two smooth solid bodies with axisymmetric surfaces S_1,S_2 and free contact lines. Evolution of liquid bridges allows two different configurations of LB_i and LB_m with multiple (five or three) interfaces of non-smooth shape. We formulate a variational problem with volume constraints and present its governing equations supplemented by boundary conditions. We find a universal relationship between curvature of the interfaces and discuss the Young relation at the singular curve where all liquids meet together.

  8. A generalized transport-velocity formulation for smoothed particle hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chi; Hu, Xiangyu Y., E-mail: xiangyu.hu@tum.de; Adams, Nikolaus A.

    2017-05-15

    The standard smoothed particle hydrodynamics (SPH) method suffers from tensile instability. In fluid-dynamics simulations this instability leads to particle clumping and void regions when negative pressure occurs. In solid-dynamics simulations, it results in unphysical structure fragmentation. In this work the transport-velocity formulation of Adami et al. (2013) is generalized for providing a solution of this long-standing problem. Other than imposing a global background pressure, a variable background pressure is used to modify the particle transport velocity and eliminate the tensile instability completely. Furthermore, such a modification is localized by defining a shortened smoothing length. The generalized formulation is suitable for fluid and solid materials with and without free surfaces. The results of extensive numerical tests on both fluid and solid dynamics problems indicate that the new method provides a unified approach for multi-physics SPH simulations.

  9. Dual-support Smoothed Particle Hydrodynamics

    CERN Document Server

    Ren, Huilong; Zhuang, Xiaoying; Rabczuk, Timon

    2016-01-01

    In this paper we develop a dual-support smoothed particle hydrodynamics (DS-SPH) that naturally satisfies the conservation of momentum, angular momentum and energy when the varying smoothing length is utilized. The DS-SPH is based on the concept of dual-support, which is introduced to consider the unbalanced interactions between the particles with different smoothing lengths. Our DS-SPH formulation can be implemented in traditional SPH with little changes and improve the computational efficiency. Several numerical examples are presented to demonstrate the capability of the method.

  10. Mineral content of the dentine remaining after chemomechanical caries removal.

    Science.gov (United States)

    Yip, H K; Beeley, J A; Stevenson, A G

    1995-01-01

    Although the dentine remaining after chemomechanical caries removal appears sound by normal clinical criteria, no definitive evidence has yet been obtained to confirm that the dentine surface is in fact mineralised. The aim of this study was to use backscattered electron (BSE) imaging and electron probe micro-analysis (EPMA) to ascertain the level of mineralisation of the dentine remaining in cavities prepared by this technique. Carious dentine was removed from carious lesions by means of N-monochloro-DL-2-aminobutyric acid (NMAB) or NMAB containing 2 mol/l urea. Sections of teeth in which caries removal was complete by normal clinical criteria were examined by EPMA and BSE. Dentine adjacent to the pulp was found to be less mineralised than the surrounding dentine. Although the superficial layer of dentine remaining on the cavity floors frequently appeared to have a slightly reduced mineral content, the results clearly indicated that there was no significant difference between this dentine and the underlying sound dentine.

  11. Smoothing Proximal Gradient Method for General Structured Sparse Learning

    CERN Document Server

    Chen, Xi; Kim, Seyoung; Carbonell, Jaime G; Xing, Eric P

    2012-01-01

    We study the problem of learning high dimensional regression models regularized by a structured-sparsity-inducing penalty that encodes prior structural information on either input or output sides. We consider two widely adopted types of such penalties as our motivating examples: 1) overlapping group lasso penalty, based on the l1/l2 mixed-norm penalty, and 2) graph-guided fusion penalty. For both types of penalties, due to their non-separability, developing an efficient optimization method has remained a challenging problem. In this paper, we propose a general optimization approach, called smoothing proximal gradient method, which can solve the structured sparse regression problems with a smooth convex loss and a wide spectrum of structured-sparsity-inducing penalties. Our approach is based on a general smoothing technique of Nesterov. It achieves a convergence rate faster than the standard first-order method, subgradient method, and is much more scalable than the most widely used interior-point method. Numer...

  12. Interferometric measurements of sea surface temperature and emissivity

    Science.gov (United States)

    Fiedler, Lars; Bakan, Stephan

    1997-09-01

    A new multispectral method to derive sea surface emissivity and temperature by using interferometer measurements of the near surface upwelling radiation in the infrared window region is presented. As reflected sky radiation adds substantial spectral variability to the otherwise spectrally smooth surface radiation, an appropriate estimate of surface emissivity allows the measured upwelling radiation to be corrected for the reflected sky component. The remaining radiation, together with the estimated surface emissivity, yields an estimate of the sea surface temperature. Measurements from an ocean pier in the Baltic Sea in October 1995 indicate an accuracy of about 0.1 K for the sea surface temperature thus derived. A strong sea surface skin effect of about 0.6 K is found in that particular case.

  13. Fractional Smoothness of Some Stochastic Integrals

    Institute of Scientific and Technical Information of China (English)

    Peng XIE; Xi Cheng ZHANG

    2007-01-01

    We study the fractional smoothness in the sense of Malliavin calculus of stochastic integralsof the form ∫10 φ(Xs)d Xs,where Xs is a semimartingale and φ belongs to some fractional Sobolev spaceover R.

  14. Spectral sequences in smooth generalized cohomology

    CERN Document Server

    Grady, Daniel

    2016-01-01

    We consider spectral sequences in smooth generalized cohomology theories, including differential generalized cohomology theories. The main differential spectral sequences will be of the Atiyah-Hirzebruch (AHSS) type, where we provide a filtration by the Cech resolution of smooth manifolds. This allows for systematic study of torsion in differential cohomology. We apply this in detail to smooth Deligne cohomology, differential topological complex K-theory, and to a smooth extension of integral Morava K-theory that we introduce. In each case we explicitly identify the differentials in the corresponding spectral sequences, which exhibit an interesting and systematic interplay between (refinement of) classical cohomology operations, operations involving differential forms, and operations on cohomology with U(1) coefficients.

  15. Integrated Groups and Smooth Distribution Groups

    Institute of Scientific and Technical Information of China (English)

    Pedro J. MIANA

    2007-01-01

    In this paper, we prove directly that α-times integrated groups define algebra homo-morphisms. We also give a theorem of equivalence between smooth distribution groups and α-times integrated groups.

  16. Cardiac, Skeletal, and smooth muscle mitochondrial respiration

    DEFF Research Database (Denmark)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I

    2014-01-01

    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial function. Therefore, this study examined mitochondrial respiratory rates in the smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscle. Cardiac......, skeletal, and smooth muscle was harvested from a total of 22 subjects (53±6 yrs) and mitochondrial respiration assessed in permeabilized fibers. Complex I+II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac, skeletal, to smooth muscle (54±1; 39±4; 15......±1 pmol•s(-1)•mg (-1), psmooth muscle (222±13; 115±2; 48±2 umol•g(-1)•min(-1), p

  17. Valiente Kroon's obstructions to smoothness at infinity

    Science.gov (United States)

    Grant, James; Tod, Paul

    2015-03-01

    We conjecture an interpretation in terms of multipole moments of the obstructions to smoothness at infinity found for time-symmetric, conformally-flat initial data by Kroon (Commun Math Phys 244(1):133-156, 2004).

  18. An Owner's Guide to Smoothed Particle Hydrodynamics

    OpenAIRE

    Martin, T.J.; Pearce, F. R.; Thomas, P. A.

    1993-01-01

    We present a practical guide to Smoothed Particle Hydrodynamics (\\SPH) and its application to astrophysical problems. Although remarkably robust, \\SPH\\ must be used with care if the results are to be meaningful since the accuracy of \\SPH\\ is sensitive to the arrangement of the particles and the form of the smoothing kernel. In particular, the initial conditions for any \\SPH\\ simulation must consist of particles in dynamic equilibrium. We describe some of the numerical difficulties that may be...

  19. Robust chaos in smooth unimodal maps

    Science.gov (United States)

    Andrecut, M.; Ali, M. K.

    2001-08-01

    Robust chaos is defined by the absence of periodic windows and coexisting attractors in some neighborhood of the parameter space. It has been conjectured that robust chaos cannot occur in smooth systems [E. Barreto, B. Hunt, and C. Grebogi, Phys. Rev. Lett. 78, 4561 (1997); 80, 3049 (1998)]. Contrary to this conjecture, we describe a general procedure for generating robust chaos in smooth unimodal maps.

  20. Observability and Controllability for Smooth Nonlinear Systems

    OpenAIRE

    Schaft, A.J. van der

    1982-01-01

    The definition of a smooth nonlinear system as proposed recently, is elaborated as a natural generalization of the more common definitions of a smooth nonlinear input-output system. Minimality for such systems can be defined in a very direct geometric way, and already implies a usual notion of observability, namely, local weak observability. As an application of this theory, it is shown that observable nonlinear Hamiltonian systems are necessarily controllable, and vice versa.

  1. Doing smooth pursuit paradigms in Windows 7

    DEFF Research Database (Denmark)

    Wilms, Inge Linda

    Smooth pursuit eye movements are interesting to study as they reflect the subject’s ability to predict movement of external targets, keep focus and move the eyes appropriately. The process of smooth pursuit requires collaboration between several systems in the brain and the resulting action may p...... in Windows 7 with live capturing of eye movements using a Tobii TX300 eye tracker. In particular, the poster describes the challenges and limitations created by the hardware and the software...

  2. Efficient Smoothing for Boundary Value Models

    Science.gov (United States)

    1989-12-29

    IEEE Transactions on Automatic Control , vol. 29, pp. 803-821, 1984. [2] A. Bagchi and H. Westdijk, "Smoothing...and likelihood ratio for Gaussian boundary value processes," IEEE Transactions on Automatic Control , vol. 34, pp. 954-962, 1989. [3] R. Nikoukhah et...77-96, 1988. [6] H. L. Weinert and U. B. Desai, "On complementary models and fixed- interval smoothing," IEEE Transactions on Automatic Control ,

  3. Beam-smoothing investigation on Heaven I

    Science.gov (United States)

    Xiang, Yi-huai; Gao, Zhi-xing; Tong, Xiao-hui; Dai, Hui; Tang, Xiu-zhang; Shan, Yu-sheng

    2007-01-01

    Directly driven targets for inertial confinement fusion (ICF) require laser beams with extremely smooth irradiance profiles to prevent hydrodynamic instabilities that destroy the spherical symmetry of the target during implosion. Such instabilities can break up and mix together the target's wall and fuel material, preventing it from reaching the density and temperature required for fusion ignition. 1,2 Measurements in the equation of state (EOS) experiments require laser beams with flat-roofed profiles to generate uniform shockwave 3. Some method for beam smooth, is thus needed. A technique called echelon-free induced spatial incoherence (EFISI) is proposed for producing smooth target beam profiles with large KrF lasers. The idea is basically an image projection technique that projects the desired time-averaged spatial profile onto the target via the laser system, using partially coherent broadband lighe. Utilize the technique, we developing beam- smoothing investigation on "Heaven I". At China Institute of Atomic Energy , a new angular multiplexing providing with beam-smoothing function has been developed, the total energy is 158J, the stability of energy is 4%, the pulse duration is 25ns, the effective diameter of focusing spot is 400um, and the ununiformity is about 1.6%, the power density on the target is about 3.7×10 12W/cm2. At present, the system have provided steady and smooth laser irradiation for EOS experiments.

  4. Simulating frictional contact in smoothed particle hydrodynamics

    Institute of Scientific and Technical Information of China (English)

    WANG; Jian; WU; Hao; GU; ChongShi; HUA; Hui

    2013-01-01

    Smoothed Particle Hydrodynamics (SPH) is a powerful tool for large deformation computation of soil flow. However, the method to simulate frictional contact in the framework of SPH is still absent and needs to be developed. This paper presents an algorithm to simulate frictional contact between soil and rigid or deformable structure in the framework of SPH. In this algo-rithm, the computational domain is divided into several sub-domains according to the existing contact boundaries, and contact forces are used as bridges of these sub-domains to fulfill problem solving. In the process of the SPH discretization for govern-ing equation of each sub-domain, the inherent problem of boundary deficiency of SPH is handled properly. Therefore, the par-ticles located at contact boundary can have precise acceleration, which is critical for contact detection. Then, based on the as-sumption that the SPH particle of soil can slightly penetrate into the structure, the contact forces along normal and tangential directions of the contact surface are computed by momentum principle, and the frictional force is modified if sliding occurs.Compared with previous methods, in which only particle-to-particle contact is considered or frictional sliding is just ignored,the method proposed in this study is more efficient and accurate, and is suitable for simulating interaction between soft materi-als and rigid or deformable structures, which are very common in geotechnical engineering. A number of numerical tests have been carried out to verify the accuracy and stability of the proposed algorithm, and the results have been compared with ana-lytical solutions or FEM results. The consistency obtained from these comparisons indicates that the algorithm is robust and can enhance the computing capability of SPH.

  5. Nonequilibrium flows with smooth particle applied mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Kum, Oyeon [Univ. of California, Davis, CA (United States)

    1995-07-01

    Smooth particle methods are relatively new methods for simulating solid and fluid flows through they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image particles is a good way to prevent a density anomaly at the boundary and to keep the fluxes continuous there. Boundary values of temperature and velocity can be separately controlled. The gradient algorithm, based on differentiating the smooth particle expression for (uρ) and (Tρ), does not show numerical instabilities for the stress tensor and heat flux vector quantities which require second derivatives in space when Fourier`s heat-flow law and Newton`s viscous force law are used. Smooth particle methods show an interesting parallel linking to them to molecular dynamics. For the inviscid Euler equation, with an isentropic ideal gas equation of state, the smooth particle algorithm generates trajectories isomorphic to those generated by molecular dynamics. The shear moduli were evaluated based on molecular dynamics calculations for the three weighting functions, B spline, Lucy, and Cusp functions. The accuracy and applicability of the methods were estimated by comparing a set of smooth particle Rayleigh-Benard problems, all in the laminar regime, to corresponding highly-accurate grid-based numerical solutions of continuum equations. Both transient and stationary smooth particle solutions reproduce the grid-based data with velocity errors on the order of 5%. The smooth particle method still provides robust solutions at high Rayleigh number where grid-based methods fails.

  6. Radial Basis Function Based Quadrature over Smooth Surfaces

    Science.gov (United States)

    2016-03-24

    Function Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.3 Weight calculations...methods: product Gaussian quadrature and finite element integration. The product Gaussian quadrature uses Gauss-Legendre nodes and quadrature weights ...with Gaussian Radial Basis Functions ,” SIAM J. Sci. Comput., vol. 33, pp. 869–892, 2011. 10. B. Fornberg and J. Zuev, “The Runge Phenomenon and

  7. Mechanism for perching on smooth surfaces using aerial impacts

    NARCIS (Netherlands)

    Wopereis, Han Willem; van der Molen, T.D.; Post, Tjark; Stramigioli, Stefano; Fumagalli, Matteo

    2016-01-01

    One important issue of multirotor UAVs is their limited operational time due to their high power consumption. This issue may hinder the application of aerial robots for security purposes as their flight endurance can be exploited for just a finite amount of time, which is not necessarily sufficient

  8. On the problems of non-smooth railway vehicle dynamics

    DEFF Research Database (Denmark)

    Thomsen, Per Grove; True, Hans

    2005-01-01

    Railway vehicle dynamics is inherently a problem of nonlinear dynamics. The unavoidable nonlinearities stem from the rail/wheel contact geometry and the stress/strain velocity relation in the rail/wheel contact surface. In addition motion delimiters and dry friction contact between elements...... in the construction create discontinuities in the mathematical dynamic model. The stick/slip of dry friction can be modelled as a discontinuity or be smoothed whereby discontinuities of higher order spatial derivatives are introduced. Higher order discontinuities are also introduced through the rail/wheel contact...

  9. OX40: Structure and function - What questions remain?

    Science.gov (United States)

    Willoughby, Jane; Griffiths, Jordana; Tews, Ivo; Cragg, Mark S

    2017-03-01

    OX40 is a type 1 transmembrane glycoprotein, reported nearly 30 years ago as a cell surface antigen expressed on activated T cells. Since its discovery, it has been validated as a bone fide costimulatory molecule for T cells and member of the TNF receptor family. However, many questions still remain relating to its function on different T cell sub-sets and with recent interest in its utility as a target for antibody-mediated immunotherapy, there is a growing need to gain a better understanding of its biology. Here, we review the expression pattern of OX40 and its ligand, discuss the structure of the receptor:ligand interaction, the downstream signalling it can elicit, its function on different T cell subsets and how antibodies might engage with it to provide effective immunotherapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. IP3 receptors regulate vascular smooth muscle contractility and hypertension

    Science.gov (United States)

    Lin, Qingsong; Zhao, Guiling; Fang, Xi; Peng, Xiaohong; Tang, Huayuan; Wang, Hong; Jing, Ran; Liu, Jie; Ouyang, Kunfu

    2016-01-01

    Inositol 1, 4, 5-trisphosphate receptor–mediated (IP3R-mediated) calcium (Ca2+) release has been proposed to play an important role in regulating vascular smooth muscle cell (VSMC) contraction for decades. However, whether and how IP3R regulates blood pressure in vivo remains unclear. To address these questions, we have generated a smooth muscle–specific IP3R triple-knockout (smTKO) mouse model using a tamoxifen-inducible system. In this study, the role of IP3R-mediated Ca2+ release in adult VSMCs on aortic vascular contractility and blood pressure was assessed following tamoxifen induction. We demonstrated that deletion of IP3Rs significantly reduced aortic contractile responses to vasoconstrictors, including phenylephrine, U46619, serotonin, and endothelin 1. Deletion of IP3Rs also dramatically reduced the phosphorylation of MLC20 and MYPT1 induced by U46619. Furthermore, although the basal blood pressure of smTKO mice remained similar to that of wild-type controls, the increase in systolic blood pressure upon chronic infusion of angiotensin II was significantly attenuated in smTKO mice. Taken together, our results demonstrate an important role for IP3R-mediated Ca2+ release in VSMCs in regulating vascular contractility and hypertension.

  11. Smoothing methods in biometry: a historic review

    Directory of Open Access Journals (Sweden)

    Schimek, Michael G.

    2005-06-01

    Full Text Available In Germany around 25 years ago nonparametric smoothing methods have found their way into statistics and with some delay also into biometry. In the early 1980's there has been what one might call a boom in theoretical and soon after also in computational statistics. The focus was on univariate nonparametric methods for density and curve estimation. For biometry however smoothing methods became really interesting in their multivariate version. This 'change of dimensionality' is still raising open methodological questions. No wonder that the simplifying paradigm of additive regression, realized in the generalized additive models (GAM, has initiated the success story of smoothing techniques starting in the early 1990's. In parallel there have been new algorithms and important software developments, primarily in the statistical programming languages S and R. Recent developments of smoothing techniques can be found in survival analysis, longitudinal analysis, mixed models and functional data analysis, partly integrating Bayesian concepts. All new are smoothing related statistical methods in bioinformatics. In this article we aim not only at a general historical overview but also try to sketch activities in the German-speaking world. Moreover, the current situation is critically examined. Finally a large number of relevant references is given.

  12. Smooth muscle actin and myosin expression in cultured airway smooth muscle cells.

    Science.gov (United States)

    Wong, J Z; Woodcock-Mitchell, J; Mitchell, J; Rippetoe, P; White, S; Absher, M; Baldor, L; Evans, J; McHugh, K M; Low, R B

    1998-05-01

    In this study, the expression of smooth muscle actin and myosin was examined in cultures of rat tracheal smooth muscle cells. Protein and mRNA analyses demonstrated that these cells express alpha- and gamma-smooth muscle actin and smooth muscle myosin and nonmuscle myosin-B heavy chains. The expression of the smooth muscle specific actin and myosin isoforms was regulated in the same direction when growth conditions were changed. Thus, at confluency in 1 or 10% serum-containing medium as well as for low-density cells (50-60% confluent) deprived of serum, the expression of the smooth muscle forms of actin and myosin was relatively high. Conversely, in rapidly proliferating cultures at low density in 10% serum, smooth muscle contractile protein expression was low. The expression of nonmuscle myosin-B mRNA and protein was more stable and was upregulated only to a small degree in growing cells. Our results provide new insight into the molecular basis of differentiation and contractile function in airway smooth muscle cells.

  13. Distribution Estimation with Smoothed Auxiliary Information

    Institute of Scientific and Technical Information of China (English)

    Xu Liu; Ahmad Ishfaq

    2011-01-01

    Distribution estimation is very important in order to make statistical inference for parameters or its functions based on this distribution. In this work we propose an estimator of the distribution of some variable with non-smooth auxiliary information, for example, a symmetric distribution of this variable. A smoothing technique is employed to handle the non-differentiable function. Hence, a distribution can be estimated based on smoothed auxiliary information. Asymptotic properties of the distribution estimator are derived and analyzed.The distribution estimators based on our method are found to be significantly efficient than the corresponding estimators without these auxiliary information. Some simulation studies are conducted to illustrate the finite sample performance of the proposed estimators.

  14. Archetypal oscillator for smooth and discontinuous dynamics.

    Science.gov (United States)

    Cao, Qingjie; Wiercigroch, Marian; Pavlovskaia, Ekaterina E; Grebogi, Celso; Thompson, J Michael T

    2006-10-01

    We propose an archetypal system to investigate transitions from smooth to discontinuous dynamics. In the smooth regime, the system bears significant similarities to the Duffing oscillator, exhibiting the standard dynamics governed by the hyperbolic structure associated with the stationary state of the double well. At the discontinuous limit, however, there is a substantial departure in the dynamics from the standard one. In particular, the velocity flow suffers a jump in crossing from one well to another, caused by the loss of local hyperbolicity due to the collapse of the stable and unstable manifolds of the stationary state. In the presence of damping and external excitation, the system has coexisting attractors and also a chaotic saddle which becomes a chaotic attractor when a smoothness parameter drops to zero. This attractor can bifurcate to a high-period periodic attractor or a chaotic sea with islands of quasiperiodic attractors depending on the strength of damping.

  15. Multiple predictor smoothing methods for sensitivity analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Helton, Jon Craig; Storlie, Curtis B.

    2006-08-01

    The use of multiple predictor smoothing methods in sampling-based sensitivity analyses of complex models is investigated. Specifically, sensitivity analysis procedures based on smoothing methods employing the stepwise application of the following nonparametric regression techniques are described: (1) locally weighted regression (LOESS), (2) additive models, (3) projection pursuit regression, and (4) recursive partitioning regression. The indicated procedures are illustrated with both simple test problems and results from a performance assessment for a radioactive waste disposal facility (i.e., the Waste Isolation Pilot Plant). As shown by the example illustrations, the use of smoothing procedures based on nonparametric regression techniques can yield more informative sensitivity analysis results than can be obtained with more traditional sensitivity analysis procedures based on linear regression, rank regression or quadratic regression when nonlinear relationships between model inputs and model predictions are present.

  16. Tapered dielectric structure in metal as a wavelength-selective surface plasmon polariton focuser

    Institute of Scientific and Technical Information of China (English)

    Zhang Yang; Zhao Qing; Liao Zhi-Min; Yu Da-Peng

    2009-01-01

    Symmetric tapered dielectric structures in metal have demonstrated applications such as the nanofocusing of surface plasmon polaxitons, as well as the waveguiding of V-channel polaxitons. Yet the fabrication of smooth-surfaced tapered structure remains an obstacle to most researchers. We have successfully developed a handy method to fabricate metal-sandwiched tapered nanostructures simply with electron beam lithography. Though these structures are slightly different from conventional symmetric V-shaped structures, systematic simulations show that similar functionality of surface plasmon polaxiton nanofocusing can still be achieved, When parameters are properly selected, wavelengthselective nanofocusing of surface plasmon polaritons can be obtained.

  17. Several methods of smoothing motion capture data

    Science.gov (United States)

    Qi, Jingjing; Miao, Zhenjiang; Wang, Zhifei; Zhang, Shujun

    2011-06-01

    Human motion capture and editing technologies are widely used in computer animation production. We can acquire original motion data by human motion capture system, and then process it by motion editing system. However, noise embed in original motion data maybe introduced by extracting the target, three-dimensional reconstruction process, optimizing algorithm and devices itself in human motion capture system. The motion data must be modified before used to make videos, otherwise the animation figures will be jerky and their behavior is unnatural. Therefore, motion smoothing is essential. In this paper, we compare and summarize three methods of smoothing original motion capture data.

  18. Smooth models for the Coulomb potential

    CERN Document Server

    González-Espinoza, Cristina E; Karwowski, Jacek; Savin, Andreas

    2016-01-01

    Smooth model potentials with parameters selected to reproduce the spectrum of one-electron atoms are used to approximate the singular Coulomb potential. Even when the potentials do not mimic the Coulomb singularity, much of the spectrum is reproduced within the chemical accuracy. For the Hydrogen atom, the smooth approximations to the Coulomb potential are more accurate for higher angular momentum states. The transferability of the model potentials from an attractive interaction (Hydrogen atom) to a repulsive one (Harmonium and the uniform electron gas) is discussed.

  19. Production of super-smooth articles

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  20. Nonlinear edge: preserving smoothing by PDEs

    Science.gov (United States)

    Ha, Yan; Liu, Jiejing

    2008-12-01

    This work introduces a new algorithm for image smoothing. Nonlinear partial differential equations (PDEs) are employed to smooth the image while preserving the edges and corners. Compared with other filters such as average filter and median filter, it is found that the effects of image denoising by the new algorithm are better than that by other filters. The experimental results show that this method can not only remove the noise but also preserve the edges and corners. Due to its simplicity and efficiency, the algorithm becomes extremely attractive.

  1. Bernstein-type approximations of smooth functions

    Directory of Open Access Journals (Sweden)

    Andrea Pallini

    2007-10-01

    Full Text Available The Bernstein-type approximation for smooth functions is proposed and studied. We propose the Bernstein-type approximation with definitions that directly apply the binomial distribution and the multivariate binomial distribution. The Bernstein-type approximations generalize the corresponding Bernstein polynomials, by considering definitions that depend on a convenient approximation coefficient in linear kernels. In the Bernstein-type approximations, we study the uniform convergence and the degree of approximation. The Bernstein-type estimators of smooth functions of population means are also proposed and studied.

  2. Mounier-Kuhn syndrome: a case of tracheal smooth muscle remodeling.

    Science.gov (United States)

    Cook, Daniel P; Adam, Ryan J; Abou Alaiwa, Mahmoud H; Eberlein, Michael; Klesney-Tait, Julia A; Parekh, Kalpaj R; Meyerholz, David K; Stoltz, David A

    2017-02-01

    Mounier-Kuhn syndrome is a rare clinical disorder characterized by tracheobronchial dilation and recurrent lower respiratory tract infections. While the etiology of the disease remains unknown, histopathological analysis of Mounier-Kuhn airways demonstrates that the disease is, in part, characterized by cellular changes in airway smooth muscle.

  3. Mesenchymal stem cell interaction with ultra smooth nanostructured diamond for wear resistant orthopaedic implants

    OpenAIRE

    Clem, William C.; Chowdhury, Shafiul; Catledge, Shane A.; Weimer, Jeffrey J.; Shaikh, Faheem M; Hennessy, Kristin M; Konovalov, Valery V.; Hill, Michael R; Waterfeld, Alfred; Bellis, Susan L.; Vohra, Yogesh K.

    2008-01-01

    Ultra smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H) -terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen (O) and fluorine (F) -terminated surfaces resisted cell adhesion, indicating that USND can be modifi...

  4. Nano-indentation Experiment for Super-smooth Surface of Glass-ceramicin Li2O-Al2O3-SiO2 System%Li2O-Al2O3-SiO2微晶玻璃超光滑表面纳米压痕实验研究

    Institute of Scientific and Technical Information of China (English)

    向勇; 陈静; 白满社; 任杰; 陈勇; 张晋宽

    2013-01-01

    Nano-indentation tests on super-smooth surface of glass-ceramic in the Li2O-Al2O3-SiO2 system are conducted through Nano-indentation technique. The mean value of nano-hardness and elastic modulus is 8.808 GPa and 77.65 GPa separately. 2D axisymmetric finite element model (FEM) was established for glass-ceramic nano-indentation process with commercial finite element software package ABAQUS. The depth-load curve calculated by FEM was compared with nano-indentation experimental depth-load curve. The material's plastic properties are gained through repeatedly modified the calculated curve obtained from FEM.%基于纳米压痕技术对Li2O-Al2O3-SiO2微晶玻璃超光滑表面进行了纳米压痕实验,通过实验测得微晶玻璃纳米硬度和弹性模量的平均值分别为8.808 GPa和77.65 GPa。采用有限元软件ABAQUS建立了微晶玻璃纳米压痕过程的2D轴对称数值模型,通过比较有限元计算所得的载荷-位移曲线和实际纳米压痕试验得到的曲线,反复修正得出材料塑性性能。

  5. Study on Control Standard of Ground Surface Settlement of Shallow -burying and Under-excavating Tunnel Based on Smoothness of Existing Line%基于既有线平顺性浅埋暗挖隧道地面沉降控制标准

    Institute of Scientific and Technical Information of China (English)

    尚淑萍; 胡玉娇; 徐彦妮

    2014-01-01

    以西安地铁4号线下穿西安铁路站场咽喉区为例,从隧道施工引起的地层变位的一般规律出发,根据隧道施工地面沉降经典 Peck 法,基于既有线的平顺性,依据规范规定的既有线路的允许偏差值,应用数学力学的基本分析方法,分析了隧道施工对既有线路的影响及浅埋暗挖隧道施工对铁路站场的路线影响,系统地建立浅埋暗挖隧道施工地表沉降控制标准,为地铁隧道工程的资金投入和施工方案、加固方案的选取提供依据。%Taking Xi’an Underground Railway No .4 Line which crosses below Xi’an Station for example ,according to the general deformation regulation in tunnel construction and the classical Peak Method ,and based on the smoothness and the permissible deviation of existing lines ,the impacts of tunnel construction on existing lines and railway stations are an -alyzed ,and the control standard for the ground surface settlement in shallow-burying and under-excavating tunnel con-struction is estabilished by using basic mathematic and mechanical analysis methods ,which could provide some references for the fund investment of metro tunnel engineerings and the selecting of construction and reinforcement schemes .

  6. Architectural Surfaces and Structures from Circular Arcs

    KAUST Repository

    Shi, Ling

    2013-12-01

    In recent decades, the popularity of freeform shapes in contemporary architecture poses new challenges to digital design. One of them is the process of rationalization, i.e. to make freeform skins or structures affordable to manufacture, which draws the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how to employ them nicely and repetitively in architectural design, in order to decrease the cost in manufacturing. Firstly, we study Darboux cyclides, which are algebraic surfaces of order ≤ 4. We provide a computational tool to identify all families of circles on a given cyclide based on the spherical model of M ̈obius geometry. Practical ways to design cyclide patches that pass through certain inputs are presented. In particular, certain triples of circle families on Darboux cyclides may be suitably arranged as 3-webs. We provide a complete classification of all possible 3-webs of circles on Darboux cyclides. We then investigate the circular arc snakes, which are smooth sequences of circu- lar arcs. We evolve the snakes such that their curvature, as a function of arc length, remains unchanged. The evolution of snakes is utilized to approximate given surfaces by circular arcs or to generated freeform shapes, and it is realized by a 2-step pro- cess. More interestingly, certain 6-arc snake with boundary constraints can produce a smooth self motion, which can be employed to build flexible structures. Another challenging topic is approximating smooth freeform skins with simple panels. We contribute to this problem area by approximating a negatively-curved 5 surface with a smooth union of rational bilinear patches. We provide a proof for vertex consistency of hyperbolic nets using the CAGD approach of the rational B ́ezier form. Moreover, we use Darboux transformations for the

  7. Full Waveform Inversion Using Nonlinearly Smoothed Wavefields

    KAUST Repository

    Li, Y.

    2017-05-26

    The lack of low frequency information in the acquired data makes full waveform inversion (FWI) conditionally converge to the accurate solution. An initial velocity model that results in data with events within a half cycle of their location in the observed data was required to converge. The multiplication of wavefields with slightly different frequencies generates artificial low frequency components. This can be effectively utilized by multiplying the wavefield with itself, which is nonlinear operation, followed by a smoothing operator to extract the artificially produced low frequency information. We construct the objective function using the nonlinearly smoothed wavefields with a global-correlation norm to properly handle the energy imbalance in the nonlinearly smoothed wavefield. Similar to the multi-scale strategy, we progressively reduce the smoothing width applied to the multiplied wavefield to welcome higher resolution. We calculate the gradient of the objective function using the adjoint-state technique, which is similar to the conventional FWI except for the adjoint source. Examples on the Marmousi 2 model demonstrate the feasibility of the proposed FWI method to mitigate the cycle-skipping problem in the case of a lack of low frequency information.

  8. Hydrodynamics of nearly smooth granular gases.

    Science.gov (United States)

    Goldhirsch, I; Noskowicz, S H; Bar-Lev, O

    2005-11-17

    Hydrodynamic equations of motion for a monodisperse collection of nearly smooth homogeneous spheres have been derived from the corresponding Boltzmann equation, using a Chapman-Enskog expansion around the elastic smooth spheres limit. Because in the smooth limit the rotational degrees of freedom are uncoupled from the translational ones, it turns out that the required hydrodynamic fields include (in addition to the standard density, velocity, and translational granular temperature fields) the (infinite) set of number densities, n(s,r, t), corresponding to the continuum of values of the angular velocities. The Chapman-Enskog expansion was carried out to high (up to 10th) order in a Sonine polynomial expansion by using a novel computer-aided method. One of the consequences of these equations is that the asymptotic spin distribution in the homogeneous cooling state for nearly smooth, nearly elastic spheres, is highly non-Maxwellian. The simple sheared flow possesses a highly non-Maxwellian distribution as well. In the case of wall-bounded shear, it is shown that the angular velocity injected at the boundaries has a finite penetration length.

  9. Smooth structures on Eschenburg spaces: numerical computations

    CERN Document Server

    Butler, Leo T

    2009-01-01

    This paper numerically computes the topological and smooth invariants of Eschenburg spaces with small fourth cohomology group, following Kruggel's determination of the Kreck-Stolz invariants of Eschenburg spaces that satisfy condition C. The GNU GMP arbitrary-precision library is utilised.

  10. Quantitative analysis of arm movement smoothness

    Science.gov (United States)

    Szczesna, Agnieszka; Błaszczyszyn, Monika

    2017-07-01

    The paper deals with the problem of motion data quantitative smoothness analysis. We investigated values of movement unit, fluidity and jerk for healthy and paralyzed arm of patients with hemiparesis after stroke. Patients were performing drinking task. To validate the approach, movement of 24 patients were captured using optical motion capture system.

  11. Autophagic regulation of smooth muscle cell biology

    Science.gov (United States)

    Salabei, Joshua K.; Hill, Bradford G.

    2014-01-01

    Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (patho)physiology. PMID:25544597

  12. Optimality conditions in smooth nonlinear programming

    NARCIS (Netherlands)

    Still, G.; Streng, M.

    1996-01-01

    This survey is concerned with necessary and sufficient optimality conditions for smooth nonlinear programming problems with inequality and equality constraints. These conditions deal with strict local minimizers of order one and two and with isolated minimizers. In most results, no constraint qualif

  13. Topics in particle filtering and smoothing

    NARCIS (Netherlands)

    Saha, Saikat

    2009-01-01

    Particle filtering/smoothing is a relatively new promising class of algorithms to deal with the estimation problems in nonlinear and/or non- Gaussian systems. Currently, this is a very active area of research and there are many issues that are not either properly addressed or are still open. One of

  14. Autonomic Modification of Intestinal Smooth Muscle Contractility

    Science.gov (United States)

    Montgomery, Laura E. A.; Tansey, Etain A.; Johnson, Chris D.; Roe, Sean M.; Quinn, Joe G.

    2016-01-01

    Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe…

  15. Recursive Filtering And Smoothing In Robot Dynamics

    Science.gov (United States)

    Rodriguez, Guillermo

    1992-01-01

    Techniques developed originally for electronic systems also useful for multibody mechanical systems. Report summarizes methods developed to solve nonlinear forward-dynamics problem for robot of multiple-link arms connected by joints. Primary objective to show equivalence between recursive methods of dynamical analysis and some filtering and smoothing techniques from state-estimation theory.

  16. Autophagic regulation of smooth muscle cell biology

    Directory of Open Access Journals (Sweden)

    Joshua K. Salabei

    2015-04-01

    Full Text Available Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (pathophysiology.

  17. Artistic edge and corner enhancing smoothing

    NARCIS (Netherlands)

    Papari, Giuseppe; Petkov, Nicolai; Campisi, Patrizio

    2007-01-01

    Two important visual properties of paintings and painting-like images are the absence of texture details and the increased sharpness of edges as compared to photographic images. Painting-like artistic effects can be achieved from photographic images by filters that smooth out texture details, while

  18. Dynamic contact angle measurements on superhydrophobic surfaces

    Science.gov (United States)

    Kim, Jeong-Hyun; Kavehpour, H. Pirouz; Rothstein, Jonathan P.

    2015-03-01

    In this paper, the dynamic advancing and receding contact angles of a series of aqueous solutions were measured on a number of hydrophobic and superhydrophobic surfaces using a modified Wilhelmy plate technique. Superhydrophobic surfaces are hydrophobic surfaces with micron or nanometer sized surface roughness. These surfaces have very large static advancing contact angles and little static contact angle hysteresis. In this study, the dynamic advancing and dynamic receding contact angles on superhydrophobic surfaces were measured as a function of plate velocity and capillary number. The dynamic contact angles measured on a smooth hydrophobic Teflon surface were found to obey the scaling with capillary number predicted by the Cox-Voinov-Tanner law, θD3 ∝ Ca. The response of the dynamic contact angle on the superhydrophobic surfaces, however, did not follow the same scaling law. The advancing contact angle was found to remain constant at θA = 160∘, independent of capillary number. The dynamic receding contact angle measurements on superhydrophobic surfaces were found to decrease with increasing capillary number; however, the presence of slip on the superhydrophobic surface was found to result in a shift in the onset of dynamic contact angle variation to larger capillary numbers. In addition, a much weaker dependence of the dynamic contact angle on capillary number was observed for some of the superhydrophobic surfaces tested.

  19. A Computational Model of Soil Adhesion and Resistance for a Non-smooth Bulldozing Plate

    Institute of Scientific and Technical Information of China (English)

    Shi Wei-ping; Ren Lu-quan; Tian Li-mei

    2005-01-01

    Adhesive forces exist between soil and the surfaces of soil-engaging components; they increase working resistance and energy consumption. This paper tries to find an approach to reduce the adhesion and resistance of bulldozing plate. A simplified mechanical model of adhesion and resistance between soil and a non-smooth bulldozing plate is proposed. The interaction force between moist soil and a non-smooth bulldozing plate is analyzed. The pressure and friction distribution on the bulldozing plate are computed, and the anti-adhesive effect of a corrugated bulldozing plate is simulated numerically.Numerical results show that the wavy bulldozing plate achieves an effective drag reduction in moist soil. The optimal wavy shape of the corrugated bulldozing plate with the minimal resistance is designed. The basic principle of reducing soil adhesion of the non-smooth surface is discovered.

  20. Role of Smooth Muscle in Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Stephen M Collins

    1996-01-01

    Full Text Available The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD. While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility and pain (via either altered motility or stricture formation. The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.

  1. Smooth muscle cell phenotype modulation and contraction on native and cross-linked polyelectrolyte multilayers.

    Science.gov (United States)

    Moussallem, Maroun D; Olenych, Scott G; Scott, Shannon L; Keller, Thomas C S; Schlenoff, Joseph B

    2009-11-09

    Smooth muscle cells convert between a motile, proliferative "synthetic" phenotype and a sessile, "contractile" phenotype. The ability to manipulate the phenotype of aortic smooth muscle cells with thin biocompatible polyelectrolyte multilayers (PEMUs) with common surface chemical characteristics but varying stiffness was investigated. The stiffness of (PAH/PAA) PEMUs was varied by heating to form covalent amide bond cross-links between the layers. Atomic force microscopy (AFM) showed that cross-linked PEMUs were thinner than those that were not cross-linked. AFM nanoindentation demonstrated that the Young's modulus ranged from 6 MPa for hydrated native PEMUs to more than 8 GPa for maximally cross-linked PEMUs. Rat aortic A7r5 smooth muscle cells cultured on native PEMUs exhibited morphology and motility of synthetic cells and expression of the synthetic phenotype markers vimentin, tropomyosin 4, and nonmuscle myosin heavy chain IIB (nmMHCIIB). In comparison, cells cultured on maximally cross-linked PEMUs exhibited the phenotype markers calponin, smooth muscle myosin heavy chain (smMHC), myocardin, transgelin, and smooth muscle alpha-actin (smActin) that are characteristic of the smooth muscle "contractile" phenotype. Consistent with those cells being "contractile", A7r5 cells grown on cross-linked PEMUs produced contractile force when stimulated with a Ca(2+) ionophore.

  2. Highly efficient DNA extraction method from skeletal remains

    Directory of Open Access Journals (Sweden)

    Irena Zupanič Pajnič

    2011-03-01

    Full Text Available Background: This paper precisely describes the method of DNA extraction developed to acquire high quality DNA from the Second World War skeletal remains. The same method is also used for molecular genetic identification of unknown decomposed bodies in routine forensic casework where only bones and teeth are suitable for DNA typing. We analysed 109 bones and two teeth from WWII mass graves in Slovenia. Methods: We cleaned the bones and teeth, removed surface contaminants and ground the bones into powder, using liquid nitrogen . Prior to isolating the DNA in parallel using the BioRobot EZ1 (Qiagen, the powder was decalcified for three days. The nuclear DNA of the samples were quantified by real-time PCR method. We acquired autosomal genetic profiles and Y-chromosome haplotypes of the bones and teeth with PCR amplification of microsatellites, and mtDNA haplotypes 99. For the purpose of traceability in the event of contamination, we prepared elimination data bases including genetic profiles of the nuclear and mtDNA of all persons who have been in touch with the skeletal remains in any way. Results: We extracted up to 55 ng DNA/g of the teeth, up to 100 ng DNA/g of the femurs, up to 30 ng DNA/g of the tibias and up to 0.5 ng DNA/g of the humerus. The typing of autosomal and YSTR loci was successful in all of the teeth, in 98 % dekalof the femurs, and in 75 % to 81 % of the tibias and humerus. The typing of mtDNA was successful in all of the teeth, and in 96 % to 98 % of the bones. Conclusions: We managed to obtain nuclear DNA for successful STR typing from skeletal remains that were over 60 years old . The method of DNA extraction described here has proved to be highly efficient. We obtained 0.8 to 100 ng DNA/g of teeth or bones and complete genetic profiles of autosomal DNA, Y-STR haplotypes, and mtDNA haplotypes from only 0.5g bone and teeth samples.

  3. Effects of (-)-desmethoxyverapamil on heart and vascular smooth muscle

    Energy Technology Data Exchange (ETDEWEB)

    Nawrath, H.; Raschack, M.

    1987-09-01

    (-)-Desmethoxyverapamil (also known as (-)-devapamil or (-)-D888) has been developed as a verapamil type radioligand for the study of calcium channels. In the present investigation, the effects of (-)-desmethoxyverapamil on action potential (AP) and force of contraction in heart muscle preparations and on tension and /sup 45/Ca influx in vascular smooth muscle are described. In part, the effects were compared with the (+)-isomer of desmethoxyverapamil and the isomers of both verapamil and methoxyverapamil. In atrial and/or ventricular heart muscle preparations from guinea pigs, cats and man, (-)-desmethoxyverapamil decreased the force of contraction and shortened the AP duration. Slow response APs were depressed, whereas dV/dtmax of phase 0 of the AP remained unchanged. The rank order of potency of the (-)-isomers was as follows: desmethoxyverapamil greater than methoxyverapamil greater than verapamil. Potassium-induced contractures and /sup 45/Ca influx were depressed by the (-)-isomers of desmethoxyverapamil, methoxyverapamil and verapamil in the same potency rank order as observed in heart muscle. The (+)-isomers exerted qualitatively similar effects at about 10 to 200 times higher concentrations. Correspondingly, the increase in potency of the racemic mixtures of the drugs was accompanied by increases in stereoselectivity. It is concluded that (-)-desmethoxyverapamil is the most potent stereoselective calcium antagonist of the verapamil type with respect to its effects on heart and vascular smooth muscle.

  4. Microintegrating smooth muscle cells into a biodegradable, elastomeric fiber matrix.

    Science.gov (United States)

    Stankus, John J; Guan, Jianjun; Fujimoto, Kazuro; Wagner, William R

    2006-02-01

    Electrospinning permits fabrication of biodegradable elastomers into matrices that can resemble the scale and mechanical behavior of the native extracellular matrix. However, achieving high-cellular density and infiltration with this technique remains challenging and time consuming. We have overcome this limitation by electrospraying vascular smooth muscle cells (SMCs) concurrently with electrospinning a biodegradable, elastomeric poly(ester urethane)urea (PEUU). Trypan blue staining revealed no significant decrease in cell viability from the fabrication process and electrosprayed SMCs spread and proliferated similar to control unprocessed SMCs. The resulting SMC microintegrated PEUU constructs were cultured under static conditions or transmural perfusion. Higher cell numbers resulted with perfusion culture with 131% and 98% more viable cells versus static culture at days 4 and 7 (pfibers after perfusion culture. SMC microintegrated PEUU was strong, flexible and anisotropic with tensile strengths ranging from 2.0 to 6.5 MPa and breaking strains from 850 to 1,700% dependent on the material axis. The ability to microintegrate smooth muscle or other cell types into a biodegradable elastomer fiber matrix embodies a novel tissue engineering approach that could be applied to fabricate high cell density elastic tissue mimetics, blood vessels or other cardiovascular tissues.

  5. Calculation note for an underground leak which remains underground

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, H.J.

    1997-05-20

    This calculation note supports the subsurface leak accident scenario which remains subsurface. It is assumed that a single walled pipe carrying waste from tank 106-C ruptures, releasing the liquid waste into the soil. In this scenario, the waste does not form a surface pool, but remains subsurface. However, above the pipe is a berm, 0.762 m (2.5 ft) high and 2.44 m (8 ft) wide, and the liquid released from the leak rises into the berm. The slurry line, which transports a source term of higher activity than the sluice line, leaks into the soil at a rate of 5% of the maximum flow rate of 28.4 L/s (450 gpm) for twelve hours. The dose recipient was placed a perpendicular distance of 100 m from the pipe. Two source terms were considered, mitigated and unmitigated release as described in section 3.4.1 of UANF-SD-WM-BIO-001, Addendum 1. The unmitigated consisted of two parts of AWF liquid and one part AWF solid. The mitigated release consisted of two parts SST liquid, eighteen parts AWF liquid, nine parts SST solid, and one part AWF solid. The isotopic breakdown of the release in these cases is presented. Two geometries were considered in preliminary investigations, disk source, and rectangular source. Since the rectangular source results from the assumption that the contamination is wicked up into the berm, only six inches of shielding from uncontaminated earth is present, while the disk source, which remains six inches below the level of the surface of the land is often shielded by a thick shield due to the slant path to the dose point. For this reason, only the rectangular source was considered in the final analysis. The source model was a rectangle 2.134 m (7 ft) thick, 0.6096 m (2 ft) high, and 130.899 m (131 ft) long. The top and sides of this rectangular source was covered with earth of density 1.6 g/cm{sup 3} to a thickness of 15.24 cm (6 in). This soil is modeled as 40% void space. The source consisted of earth of the same density with the void spaces filled with

  6. Validation of CMIP5 multimodel ensembles through the smoothness of climate variables

    KAUST Repository

    Lee, Myoungji

    2015-05-14

    Smoothness is an important characteristic of a spatial process that measures local variability. If climate model outputs are realistic, then not only the values at each grid pixel but also the relative variation over nearby pixels should represent the true climate. We estimate the smoothness of long-term averages for land surface temperature anomalies in the Coupled Model Intercomparison Project Phase 5 (CMIP5), and compare them by climate regions and seasons. We also compare the estimated smoothness of the climate outputs in CMIP5 with those of reanalysis data. The estimation is done through the composite likelihood approach for locally self-similar processes. The composite likelihood that we consider is a product of conditional likelihoods of neighbouring observations. We find that the smoothness of the surface temperature anomalies in CMIP5 depends primarily on the modelling institution and on the climate region. The seasonal difference in the smoothness is generally small, except for some climate regions where the average temperature is extremely high or low.

  7. A Generalized Eigensolver based on Smoothed Aggregation (GES-SA) for Initializing Smoothed Aggregation Multigrid (SA)

    Energy Technology Data Exchange (ETDEWEB)

    Brezina, M; Manteuffel, T; McCormick, S; Ruge, J; Sanders, G; Vassilevski, P S

    2007-05-31

    Consider the linear system Ax = b, where A is a large, sparse, real, symmetric, and positive definite matrix and b is a known vector. Solving this system for unknown vector x using a smoothed aggregation multigrid (SA) algorithm requires a characterization of the algebraically smooth error, meaning error that is poorly attenuated by the algorithm's relaxation process. For relaxation processes that are typically used in practice, algebraically smooth error corresponds to the near-nullspace of A. Therefore, having a good approximation to a minimal eigenvector is useful to characterize the algebraically smooth error when forming a linear SA solver. This paper discusses the details of a generalized eigensolver based on smoothed aggregation (GES-SA) that is designed to produce an approximation to a minimal eigenvector of A. GES-SA might be very useful as a standalone eigensolver for applications that desire an approximate minimal eigenvector, but the primary aim here is for GES-SA to produce an initial algebraically smooth component that may be used to either create a black-box SA solver or initiate the adaptive SA ({alpha}SA) process.

  8. Degenerate polynomial patches of degree 4 and 5 used for geometrically smooth interpolation in R3

    NARCIS (Netherlands)

    Neamtu, M.; Pfluger, P.R.

    1994-01-01

    The problem of interpolating scattered 3D data by a geometrically smooth surface is considered. A completely local method is proposed, based on employing degenerate triangular Bernstein-Bézier patches. An analysis of these patches is given and some numerical experiments with quartic and quintic patc

  9. CD40 and OX40 ligand are differentially regulated on asthmatic airway smooth muscle

    NARCIS (Netherlands)

    Krimmer, D I; Loseli, M; Hughes, J M; Oliver, B G G; Moir, L M; Hunt, N H; Black, J L; Burgess, J K

    2009-01-01

    BACKGROUND: CD40 and OX40 Ligand (OX40L) are cell-surface molecules expressed on airway smooth muscle (ASM) that can enhance inflammatory cell activation and survival. The aim of this study was to examine the effect of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on ASM

  10. Monocyte-expressed urokinase regulates human vascular smooth muscle cell migration in a coculture model.

    Science.gov (United States)

    Kusch, Angelika; Tkachuk, Sergey; Lutter, Steffen; Haller, Hermann; Dietz, Rainer; Lipp, Martin; Dumler, Inna

    2002-01-01

    Interactions of vascular smooth muscle cells (VSMC) with monocytes recruited to the arterial wall at a site of injury, with resultant modulation of VSMC growth and migration, are central to the development of vascular intimal thickening. Urokinase-type plasminogen activator (uPA) expressed by monocytes is a potent chemotactic factor for VSMC and might serve for the acceleration of vascular remodeling. In this report, we demonstrate that coculture of human VSMC with freshly isolated peripheral blood-derived human monocytes results in significant VSMC migration that increases during the coculture period. Accordingly, VSMC adhesion was inhibited with similar kinetics. VSMC proliferation, however, was not affected and remained at the same basal level during the whole period of coculture. The increase of VSMC migration in coculture was equivalent to the uPA-induced migration of monocultured VSMC and was blocked by addition into coculture of soluble uPAR (suPAR). Analysis of uPA and uPAR expression in cocultured cells demonstrated that monocytes are a major source of uPA, whose expression increases in coculture five-fold, whereas VSMC display an increased expression of cell surface-associated uPAR. These findings indicate that upregulated uPA production by monocytes following vascular injury acts most likely as an endogenous activator of VSMC migration contributing to the remodeling of vessel walls.

  11. Lithium-ion battery remaining useful life prediction based on grey support vector machines

    Directory of Open Access Journals (Sweden)

    Xiaogang Li

    2015-12-01

    Full Text Available In this article, an improved grey prediction model is proposed to address low-accuracy prediction issue of grey forecasting model. The first step is using a trigonometric function to transform the original data sequence to smooth the data, which is called smoothness of grey prediction model, and then a grey support vector machine model by integrating the improved grey model with support vector machine is introduced. At the initial stage of the model, trigonometric functions and accumulation generation operation can be used to preprocess the data, which enhances the smoothness of the data and reduces the associated randomness. In addition, support vector machine is implemented to establish a prediction model for the pre-processed data and select the optimal model parameters via genetic algorithms. Finally, the data are restored through the ‘regressive generate’ operation to obtain the forecasting data. To prove that the grey support vector machine model is superior to the other models, the battery life data from the Center for Advanced Life Cycle Engineering are selected, and the presented model is used to predict the remaining useful life of the battery. The predicted result is compared to that of grey model and support vector machines. For a more intuitive comparison of the three models, this article quantifies the root mean square errors for these three different models in the case of different ratio of training samples and prediction samples. The results show that the effect of grey support vector machine model is optimal, and the corresponding root mean square error is only 3.18%.

  12. SPHGR: Smoothed-Particle Hydrodynamics Galaxy Reduction

    Science.gov (United States)

    Thompson, Robert

    2015-02-01

    SPHGR (Smoothed-Particle Hydrodynamics Galaxy Reduction) is a python based open-source framework for analyzing smoothed-particle hydrodynamic simulations. Its basic form can run a baryonic group finder to identify galaxies and a halo finder to identify dark matter halos; it can also assign said galaxies to their respective halos, calculate halo & galaxy global properties, and iterate through previous time steps to identify the most-massive progenitors of each halo and galaxy. Data about each individual halo and galaxy is collated and easy to access. SPHGR supports a wide range of simulations types including N-body, full cosmological volumes, and zoom-in runs. Support for multiple SPH code outputs is provided by pyGadgetReader (ascl:1411.001), mainly Gadget (ascl:0003.001) and TIPSY (ascl:1111.015).

  13. Robust Metric Learning by Smooth Optimization

    CERN Document Server

    Huang, Kaizhu; Xu, Zenglin; Liu, Cheng-Lin

    2012-01-01

    Most existing distance metric learning methods assume perfect side information that is usually given in pairwise or triplet constraints. Instead, in many real-world applications, the constraints are derived from side information, such as users' implicit feedbacks and citations among articles. As a result, these constraints are usually noisy and contain many mistakes. In this work, we aim to learn a distance metric from noisy constraints by robust optimization in a worst-case scenario, to which we refer as robust metric learning. We formulate the learning task initially as a combinatorial optimization problem, and show that it can be elegantly transformed to a convex programming problem. We present an efficient learning algorithm based on smooth optimization [7]. It has a worst-case convergence rate of O(1/{\\surd}{\\varepsilon}) for smooth optimization problems, where {\\varepsilon} is the desired error of the approximate solution. Finally, our empirical study with UCI data sets demonstrate the effectiveness of ...

  14. Anisotropic properties of tracheal smooth muscle tissue.

    Science.gov (United States)

    Sarma, P A; Pidaparti, R M; Meiss, R A

    2003-04-01

    The anisotropic (directional-dependent) properties of contracting tracheal smooth muscle tissue are estimated from a computational model based on the experimental data of length-dependent stiffness. The area changes are obtained at different muscle lengths from experiments in which stimulated muscle undergoes unrestricted shortening. Then, through an interative process, the anisotropic properties are estimated by matching the area changes obtained from the finite element analysis to those derived from the experiments. The results obtained indicate that the anisotropy ratio (longitudinal stiffness to transverse stiffness) is about 4 when the smooth muscle undergoes 70% strain shortening, indicating that the transverse stiffness reduces as the longitudinal stiffness increases. It was found through a sensitivity analysis from the simulation model that the longitudinal stiffness and the in-plane shear modulus are not very sensitive as compared to major Poisson's ratio to the area changes of the muscle tissue. Copyright 2003 Wiley Periodicals, Inc.

  15. On smoothness-asymmetric null infinities

    Energy Technology Data Exchange (ETDEWEB)

    Valiente Kroon, Juan Antonio [School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2006-05-21

    We discuss the existence of asymptotically Euclidean initial data sets for the vacuum Einstein field equations which would give rise (modulo an existence result for the evolution equations near spatial infinity) to developments with a past and a future null infinity of different smoothness. For simplicity, the analysis is restricted to the class of conformally flat, axially symmetric initial data sets. It is shown how the free parameters in the second fundamental form of the data can be used to satisfy certain obstructions to the smoothness of null infinity. The resulting initial data sets could be interpreted as those of some sort of (nonlinearly) distorted Schwarzschild black hole. Their developments would be that they admit a peeling future null infinity, but at the same time have a polyhomogeneous (non-peeling) past null infinity.

  16. Quantum state smoothing for classical mixtures

    CERN Document Server

    Tan, D; Mølmer, K; Murch, K W

    2016-01-01

    In quantum mechanics, wave functions and density matrices represent our knowledge about a quantum system and give probabilities for the outcomes of measurements. If the combined dynamics and measurements on a system lead to a density matrix $\\rho(t)$ with only diagonal elements in a given basis $\\{|n\\rangle\\}$, it may be treated as a classical mixture, i.e., a system which randomly occupies the basis states $|n\\rangle$ with probabilities $\\rho_{nn}(t)$. Fully equivalent to so-called smoothing in classical probability theory, subsequent probing of the occupation of the states $|n\\rangle$ improves our ability to retrodict what was the outcome of a projective state measurement at time $t$. Here, we show with experiments on a superconducting qubit that the smoothed probabilities do not, in the same way as the diagonal elements of $\\rho$, permit a classical mixture interpretation of the state of the system at the past time $t$.

  17. Protostellar outflows with Smoothed Particle Magnetohydrodynamics (SPMHD)

    CERN Document Server

    Bürzle, Florian; Stasyszyn, Federico; Dolag, Klaus; Klessen, Ralf S

    2011-01-01

    The protostellar collapse of a molecular cloud core is usually accompanied by outflow phenomena. The latter are thought to be driven by magnetorotational processes from the central parts of the protostellar disc. While several 3D AMR/nested grid studies of outflow phenomena in collapsing magnetically supercritical dense cores have been reported in the literature, so far no such simulation has been performed using the Smoothed Particle Hydrodynamics (SPH) method. This is mainly due to intrinsic numerical difficulties in handling magnetohydrodynamics within SPH, which only recently were partly resolved. In this work, we use an approach where we evolve the magnetic field via the induction equation, augmented with stability correction and divergence cleaning schemes. We consider the collapse of a rotating core of one solar mass, threaded by a weak magnetic field initially parallel to the rotation axis so that the core is magnetically supercritical. We show, that Smoothed Particle Magnetohydrodynamics (SPMHD) is a...

  18. Just-in-Time Smoothing Through Batching

    OpenAIRE

    Wieslaw Kubiak; Mesut Yavuz

    2008-01-01

    This paper presents two methods to solve the production smoothing problem in mixed-model just-in-time (JIT) systems with large setup and processing time variability between different models the systems produce. The problem is motivated by production planning at a leading U.S. automotive pressure hose manufacturer. One method finds all Pareto-optimal solutions that minimize total production rate variation of models and work in process (WIP), and maximize system utilization and responsiveness. ...

  19. Virtual Cinematography Using Optimization and Temporal Smoothing

    OpenAIRE

    Litteneker, Alan Ulfers

    2016-01-01

    The problem of automatic virtual cinematography is often approached as an optimization problem. By identifying the extrema of an objective function matching some desired parameters, such as those common in live action photography or cinematography, a suitable camera pose or path can be automatically determined. With several constraints on function form, multiple objective functions can be combined into a single optimizable function, which can be further extended to model the smoothness of the...

  20. GLOBAL SMOOTHNESS PRESERVATION BY BIVARIATE INTERPOLATION OPERATORS

    Institute of Scientific and Technical Information of China (English)

    S.G.Gal; J.Szabados

    2003-01-01

    Extending the results of [4] in the univariate case, in this paper we prove that the bivariate interpolation polynomials of Hermite-Fejer based on the Chebyshev nodes of the first kind, those of Lagrange based on the Chebyshev nodes of second kind and ± 1, and those of bivariate Shepard operators, have the property of partial preservation of global smoothness, with respect to various bivariate moduli of continuity.

  1. The Smooth Muscle of the Artery

    Science.gov (United States)

    1975-01-01

    ruling out the oossibility that depolarization is a junction potential due to rnovement. The low resting potential shown is indicative of the degree of...which is embryologically Soditm Pump in the Con- and functionally related to vascular trol ot %tscle Contrac- smooth muscle, many of the electrical...consideration a 5-hydroxytryptamine as well as histamine as being the factor that we are studying. This does not rule out the posni- bility that either

  2. Robust Filtering and Smoothing with Gaussian Processes

    OpenAIRE

    Deisenroth, Marc Peter; Turner, Ryan; Huber, Marco F.; Hanebeck, Uwe D.; Rasmussen, Carl Edward

    2012-01-01

    We propose a principled algorithm for robust Bayesian filtering and smoothing in nonlinear stochastic dynamic systems when both the transition function and the measurement function are described by non-parametric Gaussian process (GP) models. GPs are gaining increasing importance in signal processing, machine learning, robotics, and control for representing unknown system functions by posterior probability distributions. This modern way of "system identification" is more robust than finding p...

  3. Demosaicing by Smoothing along 1D Features

    OpenAIRE

    Ajdin, Boris; Hullin, Matthias B.; Fuchs, Christian; Seidel, Hans-Peter; Lensch, Hendrik P. A.

    2008-01-01

    Most digital cameras capture color pictures in the form of an image mosaic, recording only one color channel at each pixel position. Therefore, an interpolation algorithm needs to be applied to reconstruct the missing color information. In this paper we present a novel Bayer pattern demosaicing approach, employing stochastic global optimization performed on a pixel neighborhood. We are minimizing a newly developed cost function that increases smoothness along one-dimen...

  4. Random Walk Smooth Transition Autoregressive Models

    OpenAIRE

    2004-01-01

    This paper extends the family of smooth transition autoregressive (STAR) models by proposing a specification in which the autoregressive parameters follow random walks. The random walks in the parameters can capture structural change within a regime switching framework, but in contrast to the time varying STAR (TV-STAR) speciifcation recently introduced by Lundbergh et al (2003), structural change in our random walk STAR (RW-STAR) setting follows a stochastic process rather than a determinist...

  5. Drop Impact on Superheated Surfaces

    NARCIS (Netherlands)

    Tran, A.T.; Staat, H.J.J.; Prosperetti, A.; Sun, C.; Lohse, D.

    2012-01-01

    At the impact of a liquid droplet on a smooth surface heated above the liquid’s boiling point, the droplet either immediately boils when it contacts the surface (“contact boiling”), or without any surface contact forms a Leidenfrost vapor layer towards the hot surface and bounces back (“gentle film

  6. The magnetic field of gastrointestinal smooth muscle activity

    Science.gov (United States)

    Bradshaw, Alan; Ladipo, Jk; Richards, William; Wikswo, John

    1997-11-01

    The gastrointestinal (GI) tract controls the absorption and transport of ingested materials. Its function is determined largely by the electrical activity of the smooth muscle that lines the GI tract. GI electrical activity consists of an omnipresent slowly oscillating wave known as the basic electrical rhythm (BER) that modulates a higher-frequency spiking activity associated with muscle contraction. The BER has been shown to be a reliable indicator of intestinal viability, and thus, recording of smooth muscle activity may have clinical value. The BER is difficult to measure with cutaneous electrodes because layers of low-conductivity fat between the GI tract and the abdominal surface attenuate the potential. On the other hand, the magnetic field associated with GI electrical activity is mostly unaffected by intervening fat layers. We recorded the magnetic fields from GI activity in 12 volunteers using a multichannel Superconducting QUantum Interference Device (SQUID) magnetometer. Characteristics typical of gastric and intestinal BER were apparent in the data. Channels near the epigastrium recorded gastric BER, and channels in intestinal areas recorded small bowel BER. These results suggest that a single multichannel SQUID magnetometer is able to measure gastrointestinal electrical activity from multiple locations around the abdomen simultaneously.

  7. Defining an olfactory receptor function in airway smooth muscle cells

    Science.gov (United States)

    Aisenberg, William H.; Huang, Jessie; Zhu, Wanqu; Rajkumar, Premraj; Cruz, Randy; Santhanam, Lakshmi; Natarajan, Niranjana; Yong, Hwan Mee; De Santiago, Breann; Oh, Jung Jin; Yoon, A-Rum; Panettieri, Reynold A.; Homann, Oliver; Sullivan, John K.; Liggett, Stephen B.; Pluznick, Jennifer L.; An, Steven S.

    2016-01-01

    Pathways that control, or can be exploited to alter, the increase in airway smooth muscle (ASM) mass and cellular remodeling that occur in asthma are not well defined. Here we report the expression of odorant receptors (ORs) belonging to the superfamily of G-protein coupled receptors (GPCRs), as well as the canonical olfaction machinery (Golf and AC3) in the smooth muscle of human bronchi. In primary cultures of isolated human ASM, we identified mRNA expression for multiple ORs. Strikingly, OR51E2 was the most highly enriched OR transcript mapped to the human olfactome in lung-resident cells. In a heterologous expression system, OR51E2 trafficked readily to the cell surface and showed ligand selectivity and sensitivity to the short chain fatty acids (SCFAs) acetate and propionate. These endogenous metabolic byproducts of the gut microbiota slowed the rate of cytoskeletal remodeling, as well as the proliferation of human ASM cells. These cellular responses in vitro were found in ASM from non-asthmatics and asthmatics, and were absent in OR51E2-deleted primary human ASM. These results demonstrate a novel chemo-mechanical signaling network in the ASM and serve as a proof-of-concept that a specific receptor of the gut-lung axis can be targeted to treat airflow obstruction in asthma. PMID:27905542

  8. On the thermodynamics of smooth muscle contraction

    Science.gov (United States)

    Stålhand, Jonas; McMeeking, Robert M.; Holzapfel, Gerhard A.

    2016-09-01

    Cell function is based on many dynamically complex networks of interacting biochemical reactions. Enzymes may increase the rate of only those reactions that are thermodynamically consistent. In this paper we specifically treat the contraction of smooth muscle cells from the continuum thermodynamics point of view by considering them as an open system where matter passes through the cell membrane. We systematically set up a well-known four-state kinetic model for the cross-bridge interaction of actin and myosin in smooth muscle, where the transition between each state is driven by forward and reverse reactions. Chemical, mechanical and energy balance laws are provided in local forms, while energy balance is also formulated in the more convenient temperature form. We derive the local (non-negative) production of entropy from which we deduce the reduced entropy inequality and the constitutive equations for the first Piola-Kirchhoff stress tensor, the heat flux, the ion and molecular flux and the entropy. One example for smooth muscle contraction is analyzed in more detail in order to provide orientation within the established general thermodynamic framework. In particular the stress evolution, heat generation, muscle shorting rate and a condition for muscle cooling are derived.

  9. Notch Signaling in Vascular Smooth Muscle Cells.

    Science.gov (United States)

    Baeten, J T; Lilly, B

    2017-01-01

    The Notch signaling pathway is a highly conserved pathway involved in cell fate determination in embryonic development and also functions in the regulation of physiological processes in several systems. It plays an especially important role in vascular development and physiology by influencing angiogenesis, vessel patterning, arterial/venous specification, and vascular smooth muscle biology. Aberrant or dysregulated Notch signaling is the cause of or a contributing factor to many vascular disorders, including inherited vascular diseases, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, associated with degeneration of the smooth muscle layer in cerebral arteries. Like most signaling pathways, the Notch signaling axis is influenced by complex interactions with mediators of other signaling pathways. This complexity is also compounded by different members of the Notch family having both overlapping and unique functions. Thus, it is vital to fully understand the roles and interactions of each Notch family member in order to effectively and specifically target their exact contributions to vascular disease. In this chapter, we will review the Notch signaling pathway in vascular smooth muscle cells as it relates to vascular development and human disease.

  10. Mineralized Remains of Morphotypes of Filamentous Cyanobacteria in Carbonaceous Meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2005-01-01

    ) investigations of freshly fractured interior surfaces of carbonaceous meteorites, terrestrial rocks, and recent microbial extremophiles and filamentous cyanobacteria. These studies have resulted in the detection in a several carbonaceous meteorites of the mineralized remains of a wide variety of complex filamentous trichomic microorganisms. These embedded forms are consistent in size and microstructure with well-preserved morphotypes of mat- forming filamentous trichomic cyanobacteria and the degraded remains of microfibrils of cyanobacterial sheaths. We present the results of comparative imaging studies and EDAX elemental analyses of recent cyanobacteria (e.g. Calothrix, Oscillatoria, and Lyngbya) that are similar in size, morphology and microstructure to morphotypes found embedded in meteorites. EDAX elemental studies reveal that forms found in carbonaceous meteorites often have highly carbonized sheaths in close association with permineralized filaments, trichomes and microbial cells. Ratios of critical bioelements (C:O, C:N, C:P, and C:S) reveal dramatic differences between microfossils in Earth rocks and meteorites and in filaments, trichomes, hormogonia, and cells of recent cyanobacteria.

  11. Validation of a smooth configuration surface for compact heat exchangers using a numerical method//Validación de la superficie de un intercambiador de calor compacto en configuración lisa utilizando un método numérico

    Directory of Open Access Journals (Sweden)

    José‐L. Leiro‐Garrido

    2014-08-01

    Full Text Available This work determines the thermo hydraulics behavior of smooth configuration surface for a compact heat exchanger by means of numerical simulation. The objective is to use the results as baseline for research in the enhancement of heat transfer and drag reduction, directed to reduce the energy consumption and diminish the environmental impact. The fin tube heat exchanger models described.The constraints used in the implementation of the equation solver are announced. The average heat transfer coefficient and pressure drop obtained from numerical simulation are compare to experimental results presented in literature for models with the same dimensions and configuration. A good agreement between numerical and experimental results is reached. Local mechanisms responsible for the heat transfer and pressure drop are detailed. The study is conducted inside thelaminar regime for frontal velocities ranging between 0.5 and 6 m/s.Key words: compact heat exchanger, heat transfer coefficient, numerical simulation, pressure drop.______________________________________________________________________________ResumenEste trabajo determina el comportamiento termo hidráulico de una superficie perteneciente a un intercambiador de calor compacto en configuración lisa utilizando un método de simulación numérica. El objetivo es caracterizar la superficie para poder utilizarla como una referencia en las comparaciones con superficies de intercambio de calor intensificadas. Los datos obtenidos seutilizaran en la determinación de los valores relativos de intensificación de la transferencia de calor y el arrastre intentando reducir el consumo energético y su impacto ambiental. Se describe el modelo de intercambiador de calor con tubos aletados. Los resultados numéricos obtenidos presentan unbuen ajuste con los valores experimentales. Los resultados del coeficiente de transferencia de calor global y la caída de presión son explicados a partir de las

  12. Isotopic Implicit Surface Meshing

    NARCIS (Netherlands)

    Boissonnat, Jean-Daniel; Cohen-Steiner, David; Vegter, Gert

    2004-01-01

    This paper addresses the problem of piecewise linear approximation of implicit surfaces. We first give a criterion ensuring that the zero-set of a smooth function and the one of a piecewise linear approximation of it are isotopic. Then, we deduce from this criterion an implicit surface meshing algor

  13. A Discontinuous Extended Kalman Filter for non-smooth dynamic problems

    Science.gov (United States)

    Chatzis, M. N.; Chatzi, E. N.; Triantafyllou, S. P.

    2017-08-01

    Problems that result into locally non-differentiable and hence non-smooth state-space equations are often encountered in engineering. Examples include problems involving material laws pertaining to plasticity, impact and highly non-linear phenomena. Estimating the parameters of such systems poses a challenge, particularly since the majority of system identification algorithms are formulated on the basis of smooth systems under the assumption of observability, identifiability and time invariance. For a smooth system, an observable state remains observable throughout the system evolution with the exception of few selected realizations of the state vector. However, for a non-smooth system the observable set of states and parameters may vary during the evolution of the system throughout a dynamic analysis. This may cause standard identification (ID) methods, such as the Extended Kalman Filter, to temporarily diverge and ultimately fail in accurately identifying the parameters of the system. In this work, the influence of observability of non-smooth systems to the performance of the Extended and Unscented Kalman Filters is discussed and a novel algorithm particularly suited for this purpose, termed the Discontinuous Extended Kalman Filter (DEKF), is proposed.

  14. Visual crowding is anisotropic along the horizontal meridian during smooth pursuit.

    Science.gov (United States)

    Harrison, W J; Remington, R W; Mattingley, J B

    2014-01-22

    Humans make smooth pursuit eye movements to foveate moving objects of interest. It is known that smooth pursuit alters visual processing, but there is currently no consensus on whether changes in vision are contingent on the direction the eyes are moving. We recently showed that visual crowding can be used as a sensitive measure of changes in visual processing, resulting from involvement of the saccadic eye movement system. The present paper extends these results by examining the effect of smooth pursuit eye movements on the spatial extent of visual crowding-the area over which visual stimuli are integrated. We found systematic changes in crowding that depended on the direction of pursuit and the distance of stimuli from the pursuit target. Relative to when no eye movement was made, the spatial extent of crowding increased for objects located contraversive to the direction of pursuit at an eccentricity of approximately 3°. By contrast, crowding for objects located ipsiversive to the direction of pursuit remained unchanged. There was no change in crowding during smooth pursuit for objects located approximately 7° from the fovea. The increased size of the crowding zone for the contraversive direction may be related to the distance that the fovea lags behind the pursuit target during smooth eye movements. Overall, our results reveal that visual perception is altered dynamically according to the intended destination of oculomotor commands.

  15. Stability of compressible boundary layers over a smooth backward-facing step

    Science.gov (United States)

    Ragab, S. A.; Nayfeh, A. H.; Krishna, R. C.

    1990-01-01

    An investigation is conducted into the determination of the credibility of interacting boundary layers in predicting compressible subsonic flows over smooth surface imperfections. The case of smooth backward-facing steps is considered. The predicted mean flows are compared with those obtained using a Navier-Stokes solver. Moreover, the linear 2-D compressible stability characteristics of both mean flows are compared. The results show that the interacting boundary-layer formulation produces accurate mean flows that yield accurate linear stability characteristics, such as growth rates and amplification factors.

  16. Some Remarks on the Boundedness and Convergence Properties of Smooth Sliding Mode Controllers

    Institute of Scientific and Technical Information of China (English)

    Wallace Moreira Bessa

    2009-01-01

    Conventional sliding mode controllers are based on the assumption of switching control, but a well-known drawback of such controllers is the chattering phenomenon. To overcome the undesirable chattering effects, the discontinuity in the control law can be smoothed out in a thin boundary layer neighboring the switching surface. In this paper, rigorous proofs of the boundedness and convergence properties of smooth sliding mode controllers are presented. This result corrects flawed conclusions previously reached in the literature. An illustrative example is also presented in order to confirm the convergence of the tracking error vector to the defined bounded region.

  17. Applying Contact Angle to a 2D Multiphase Smoothed Particle Hydrodynamics Model

    OpenAIRE

    Farrokhpanah, Amirsaman; Samareh, Babak; Mostaghimi, Javad

    2016-01-01

    Equilibrium contact angle of liquid drops over horizontal surfaces has been modeled using Smoothed Particle Hydrodynamics (SPH). The model is capable of accurate implementation of contact angles to stationary and moving contact lines. In this scheme, the desired value for stationary or dynamic contact angle is used to correct the profile near the triple point. This is achieved by correcting the surface normals near the contact line and also interpolating the drop profile into the boundaries. ...

  18. Smooth Fano polytopes can not be inductively constructed

    DEFF Research Database (Denmark)

    Øbro, Mikkel

    2008-01-01

    We examine a concrete smooth Fano 5-polytope $P$ with 8 vertices with the following properties: There does not exist a smooth Fano 5-polytope $Q$ with 7 vertices such that $P$ contains $Q$, and there does not exist a smooth Fano 5-polytope $R$ with 9 vertices such that $R$ contains $P$. As the po...

  19. Exponential smoothing for financial time series data forecasting

    Directory of Open Access Journals (Sweden)

    Kuzhda, Tetyana Ivanivna

    2014-05-01

    Full Text Available The article begins with the formulation for predictive learning called exponential smoothing forecasting. The exponential smoothing is commonly applied to financial markets such as stock or bond, foreign exchange, insurance, credit, primary and secondary markets. The exponential smoothing models are useful in providing the valuable decision information for investors. Simple and double exponential smoothing models are two basic types of exponential smoothing method. The simple exponential smoothing method is suitable for financial time series forecasting for the specified time period. The simple exponential smoothing weights past observations with exponentially decreasing weights to forecast future values. The double exponential smoothing is a refinement of the simple exponential smoothing model but adds another component which takes into account any trend in the data. The double exponential smoothing is designed to address this type of data series by taking into account any trend in the data. Measurement of the forecast accuracy is described in this article. Finally, the quantitative value of the price per common share forecast using simple exponential smoothing is calculated. The applied recommendations concerning determination of the price per common share forecast using double exponential smoothing are shown in the article.

  20. Alternative Smoothing and Scaling Strategies for Weighted Composite Scores

    Science.gov (United States)

    Moses, Tim

    2014-01-01

    In this study, smoothing and scaling approaches are compared for estimating subscore-to-composite scaling results involving composites computed as rounded and weighted combinations of subscores. The considered smoothing and scaling approaches included those based on raw data, on smoothing the bivariate distribution of the subscores, on smoothing…

  1. Neurophysiology and Neuroanatomy of Smooth Pursuit in Humans

    Science.gov (United States)

    Lencer, Rebekka; Trillenberg, Peter

    2008-01-01

    Smooth pursuit eye movements enable us to focus our eyes on moving objects by utilizing well-established mechanisms of visual motion processing, sensorimotor transformation and cognition. Novel smooth pursuit tasks and quantitative measurement techniques can help unravel the different smooth pursuit components and complex neural systems involved…

  2. Using smooth sheets to describe groundfish habitat in Alaskan waters, with specific application to two flatfishes

    Science.gov (United States)

    Zimmermann, Mark; Reid, Jane A.; Golden, Nadine

    2016-10-01

    In this analysis we demonstrate how preferred fish habitat can be predicted and mapped for juveniles of two Alaskan groundfish species - Pacific halibut (Hippoglossus stenolepis) and flathead sole (Hippoglossoides elassodon) - at five sites (Kiliuda Bay, Izhut Bay, Port Dick, Aialik Bay, and the Barren Islands) in the central Gulf of Alaska. The method involves using geographic information system (GIS) software to extract appropriate information from National Ocean Service (NOS) smooth sheets that are available from NGDC (the National Geophysical Data Center). These smooth sheets are highly detailed charts that include more soundings, substrates, shoreline and feature information than the more commonly-known navigational charts. By bringing the information from smooth sheets into a GIS, a variety of surfaces, such as depth, slope, rugosity and mean grain size were interpolated into raster surfaces. Other measurements such as site openness, shoreline length, proportion of bay that is near shore, areas of rocky reefs and kelp beds, water volumes, surface areas and vertical cross-sections were also made in order to quantify differences between the study sites. Proper GIS processing also allows linking the smooth sheets to other data sets, such as orthographic satellite photographs, topographic maps and precipitation estimates from which watersheds and runoff can be derived. This same methodology can be applied to larger areas, taking advantage of these free data sets to describe predicted groundfish essential fish habitat (EFH) in Alaskan waters.

  3. MortalitySmooth: An R Package for Smoothing Poisson Counts with P-Splines

    Directory of Open Access Journals (Sweden)

    Carlo G. Camarda

    2012-07-01

    Full Text Available The MortalitySmooth package provides a framework for smoothing count data in both one- and two-dimensional settings. Although general in its purposes, the package is specifically tailored to demographers, actuaries, epidemiologists, and geneticists who may be interested in using a practical tool for smoothing mortality data over ages and/or years. The total number of deaths over a specified age- and year-interval is assumed to be Poisson-distributed, and P-splines and generalized linear array models are employed as a suitable regression methodology. Extra-Poisson variation can also be accommodated.Structured in an S3 object orientation system, MortalitySmooth has two main functions which t the data and dene two classes of objects:Mort1Dsmooth and Mort2Dsmooth. The methods for these classes (print, summary, plot, predict, and residuals are also included. These features make it easy for users to extract and manipulate the outputs.In addition, a collection of mortality data is provided. This paper provides an overview of the design, aims, and principles of MortalitySmooth, as well as strategies for applying it and extending its use.

  4. Evolution of the transfer function characterization of surface scatter phenomena

    Science.gov (United States)

    Harvey, James E.; Pfisterer, Richard N.

    2016-09-01

    Based upon the empirical observation that BRDF measurements of smooth optical surfaces exhibited shift-invariant behavior when plotted versus    o , the original Harvey-Shack (OHS) surface scatter theory was developed as a scalar linear systems formulation in which scattered light behavior was characterized by a surface transfer function (STF) reminiscent of the optical transfer function (OTF) of modern image formation theory (1976). This shift-invariant behavior combined with the inverse power law behavior when plotting log BRDF versus log   o was quickly incorporated into several optical analysis software packages. Although there was no explicit smooth-surface approximation in the OHS theory, there was a limitation on both the incident and scattering angles. In 1988 the modified Harvey-Shack (MHS) theory removed the limitation on the angle of incidence; however, a moderate-angle scattering limitation remained. Clearly for large incident angles the BRDF was no longer shift-invariant as a different STF was now required for each incident angle. In 2011 the generalized Harvey-Shack (GHS) surface scatter theory, characterized by a two-parameter family of STFs, evolved into a practical modeling tool to calculate BRDFs from optical surface metrology data for situations that violate the smooth surface approximation inherent in the Rayleigh-Rice theory and/or the moderate-angle limitation of the Beckmann-Kirchhoff theory. And finally, the STF can be multiplied by the classical OTF to provide a complete linear systems formulation of image quality as degraded by diffraction, geometrical aberrations and surface scatter effects from residual optical fabrication errors.

  5. Effect of droplet size on wetting behavior on laser textured SiC surface

    Science.gov (United States)

    Wang, Rong; Bai, Shaoxian

    2015-10-01

    Effect of droplet size on wetting behavior on laser textured SiC surface was studied in this work. The micro-square-convex surface was processed on smooth surface with intrisinc contact angle 101°. Then contact angles were measured on both smooth and textured surface by sessile drop method using deionized water with different droplet volume. It was found that there was significant droplet size effect on wetting behaviors for the textured SiC surface. Contact angles on smooth surface kept stable for different water droplet volume with a variation amplitude 13°. However, contact angles increased significantly from 42.25° to 131.25° with increasing droplet volume from 0.001 μL to 1 μL, then remained unchanged when the droplet volume exceeds 1 μL. The correlation analysis shows that contact angles increase with the increasing ratio of base diameter and groove width, then keep stable when the ratio exceeds 25, which explains the wetting behavior for different droplet volume.

  6. Comparison between rough and smooth plates within the same Rayleigh-Benard cell

    Science.gov (United States)

    Rusaouen, Eleonore; Salort, Julien; Seychelles, Fanny; Tisserand, Jean-Christophe; Creyssels, Matthieu; Liot, Olivier; Castaing, Bernard; Chilla, Francesca

    2012-11-01

    A Rayleigh-Benard cell consist in a tank filled of a fluid on which a temperature difference is imposed thanks to a cold plate at top and a hot at bottom. Movement is induced by the buoyancy force. Considering most of experimental apparatus previously used all around the world, both plates are smooth. Recently, the effect of roughness on thermal transfer had become a subject of interest. The present experiment is an asymetrical rough Rayleigh-Benard cell. Indeed the hot plate is rough whereas the cold plate is still smooth. Previously, tests conducted with 2 mm high roughness showed independence of the two plates and a heat flux enhancement on the rough plate, which appeared to be greater than expected from the surface increase. This regime was caracterized by a Nu ~ Ra 1 / 2 law. New results obtained with a 4mm high roughness also show this flux enhancement and the independent behaviour of the plates. But a transition appears at high Rayleigh from the 1/2 power law regime to a 1/3 one. Former results obtained in the same symetrical smooth/smooth cell also showed a 1/3 law. But the rough 1/3 regime reveals a multiplier coefficient of 1.6 with the smooth one.

  7. A smooth impact rotation motor using a multi-layered torsional piezoelectric actuator.

    Science.gov (United States)

    Morita, T; Yoshida, R; Okamoto, Y; Kurosawa, M K; Higuchi, T

    1999-01-01

    A smooth impact rotation motor was fabricated and successfully operated using a torsional piezo actuator. Yoshida et al. reported a linear type smooth impact motor in 1997. This linear motor demonstrated a high output force and a long stroke. A superior feature of the smooth impact drive is a high positioning resolution compared with an impact drive. The positioning resolution of SIDM (smooth impact drive mechanism) is equal to the piezo displacement. The reported positioning resolution of the linear type was 5 nm. Our rotation motor utilized a torsional actuator containing multi-layered piezoelectric material. The torsional actuator was cylindrical in shape with an outer diameter of 15 mm, an inner diameter of 10 mm, and a length of 11 mm. Torsional vibration performance was measured with a laser Doppler vibrometer. The obtained torsional displacement agreed with the calculated values and was sufficient to drive a rotor. The rotor was operated with a saw-shaped input voltage (180 V; 8 kHz). The revolution direction was reversible. The maximum revolution speed was 27 rpm, and the maximum output torque was 56 gfcm. In general, smooth-impact drives do not show high efficiency; however, the level of efficiency of our results (max., 0.045%) could be increased by improving the contact surface material. In addition, we are studying quantitative consideration, for example, about the optimum pre-load or frictional force.

  8. The effect of trinitrobenzene sulfonic acid on gut-derived smooth muscle cell arachidonic acid metabolism: role of endogenous prostanoids

    Directory of Open Access Journals (Sweden)

    W. E. Longo

    1997-01-01

    Full Text Available The contribution of smooth muscle cells as a potential source of eicosanoid production during inflammatory states remains to be elucidated. We investigated the effect of trinitrobenzene sulfonic acid (TNB, a known pro-inflammatory agent, on jejunal smooth muscle cell eicosanoid production. Human gut-derived smooth muscle cells (HISM were incubated with TNB for 1 hour. Additionally, some cells were preincubated with either dimethylthiourea, or indomethacin for 1 hour before exposure to identical concentrations of TNB. Incubation with TNB led to significant increases in PGE2 and 6-keto PGF-1α release, but not leukotriene B4 release; responses which were both inhibited by dimethylthiourea and indomethacin treatment. Our results suggest that gutderived smooth muscle cells may represent an important source of proinflammatory prostanoids but not leukotrienes during inflammatory states of the intestine. The inhibition of prostanoid activity by thiourea may be mediated by suppression of cyclooxygenase activity in this cell line.

  9. A new smoothing scheme for mathematical programs with complementarity constraints

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, we consider a mathematical program with complementarity constraints (MPCC). We present a new smoothing scheme for this problem, which makes the primal structure of the complementarity part unchanged mostly. For the new smoothing problem, we show that the linear independence constraint qualification (LICQ) holds under some conditions. We also analyze the convergence behavior of the smoothing problem, and get some sufficient conditions such that an accumulation point of stationary points of the smoothing problems is C (M, B)-stationarity respectively. Based on the smoothing problem, we establish an algorithm to solve the primal MPCC problem. Some numerical experiments are given in the paper.

  10. Airway smooth muscle growth in asthma: proliferation, hypertrophy, and migration.

    Science.gov (United States)

    Bentley, J Kelley; Hershenson, Marc B

    2008-01-01

    Increased airway smooth muscle mass is present in fatal and non-fatal asthma. However, little information is available regarding the cellular mechanism (i.e., hyperplasia vs. hypertrophy). Even less information exists regarding the functional consequences of airway smooth muscle remodeling. It would appear that increased airway smooth muscle mass would tend to increase airway narrowing and airflow obstruction. However, the precise effects of increased airway smooth muscle mass on airway narrowing are not known. This review will consider the evidence for airway smooth muscle cell proliferation and hypertrophy in asthma, potential functional effects, and biochemical mechanisms.

  11. Beilinson's Hodge conjecture for smooth varieties

    CERN Document Server

    de Jeu, Rob

    2011-01-01

    Consider the cycle class map cl_{r,m} : CH^r(U,m;\\Q) \\to \\Gamma H^{2r-m}(U,\\Q(r)), where CH^r(U,m;\\Q) is Bloch's higher Chow group (tensored with \\Q) of a smooth complex quasi-projective variety U, and H^{2r-m}(U,\\Q(r)) is singular cohomology. We study the image of cl_{r,m} in terms of kernels of Abel-Jacobi maps. When r=m, we deduce from the Bloch-Kato theorem that the cokernel of cl_{r,m} at the generic point of U is the same for integral or rational coefficients.

  12. Workshop on advances in smooth particle hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Wingate, C.A.; Miller, W.A.

    1993-12-31

    This proceedings contains viewgraphs presented at the 1993 workshop held at Los Alamos National Laboratory. Discussed topics include: negative stress, reactive flow calculations, interface problems, boundaries and interfaces, energy conservation in viscous flows, linked penetration calculations, stability and consistency of the SPH method, instabilities, wall heating and conservative smoothing, tensors, tidal disruption of stars, breaking the 10,000,000 particle limit, modelling relativistic collapse, SPH without H, relativistic KSPH avoidance of velocity based kernels, tidal compression and disruption of stars near a supermassive rotation black hole, and finally relativistic SPH viscosity and energy.

  13. Compressive Sensing via Nonlocal Smoothed Rank Function.

    Science.gov (United States)

    Fan, Ya-Ru; Huang, Ting-Zhu; Liu, Jun; Zhao, Xi-Le

    2016-01-01

    Compressive sensing (CS) theory asserts that we can reconstruct signals and images with only a small number of samples or measurements. Recent works exploiting the nonlocal similarity have led to better results in various CS studies. To better exploit the nonlocal similarity, in this paper, we propose a non-convex smoothed rank function based model for CS image reconstruction. We also propose an efficient alternating minimization method to solve the proposed model, which reduces a difficult and coupled problem to two tractable subproblems. Experimental results have shown that the proposed method performs better than several existing state-of-the-art CS methods for image reconstruction.

  14. Impact modeling with Smooth Particle Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Stellingwerf, R.F.; Wingate, C.A.

    1993-07-01

    Smooth Particle Hydrodynamics (SPH) can be used to model hypervelocity impact phenomena via the addition of a strength of materials treatment. SPH is the only technique that can model such problems efficiently due to the combination of 3-dimensional geometry, large translations of material, large deformations, and large void fractions for most problems of interest. This makes SPH an ideal candidate for modeling of asteroid impact, spacecraft shield modeling, and planetary accretion. In this paper we describe the derivation of the strength equations in SPH, show several basic code tests, and present several impact test cases with experimental comparisons.

  15. Mineralized remains of morphotypes of filamentous cyanobacteria in carbonaceous meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2005-09-01

    The quest for conclusive evidence of microfossils in meteorites has been elusive. Abiotic microstructures, mineral grains, and even coating artifacts may mimic unicellular bacteria, archaea and nanobacteria with simple spherical or rod morphologies (i.e., cocci, diplococci, bacilli, etc.). This is not the case for the larger and more complex microorganisms, colonies and microbial consortia and ecosystems. Microfossils of algae, cyanobacteria, and cyanobacterial and microbial mats have been recognized and described from many of the most ancient rocks on Earth. The filamentous cyanobacteria and sulphur-bacteria have very distinctive size ranges, complex and recognizable morphologies and visibly differentiated cellular microstructures. The taphonomic modes of fossilization and the life habits and processes of these microorganisms often result in distinctive chemical biosignatures associated with carbonization, silicification, calcification, phosphatization and metal-binding properties of their cell-walls, trichomes, sheaths and extracellular polymeric substances (EPS). Valid biogenicity is provided by the combination of a suite of known biogenic elements (that differ from the meteorite matrix) found in direct association with recognizable and distinct biological features and microstructures (e.g., uniseriate or multiseriate filaments, trichomes, sheaths and cells of proper size/size range); specialized cells (e.g., basal or apical cells, hormogonia, akinetes, and heterocysts); and evidence of growth characteristics (e.g., spiral filaments, robust or thin sheaths, laminated sheaths, true or false branching of trichomes, tapered or uniform filaments) and evidence of locomotion (e.g. emergent cells and trichomes, coiling hormogonia, and hollow or flattened and twisted sheaths). Since 1997 we have conducted Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) studies of freshly fractured interior surfaces of carbonaceous meteorites, terrestrial

  16. Laser smoothing of sub-micron grooves in hydroxyl-rich fused silica

    Energy Technology Data Exchange (ETDEWEB)

    Shen, N; Matthews, M J; Fair, J E; Britten, J A; Nguyen, H T; Cooke, D; Elhadj, S; Yang, S T

    2009-10-30

    Nano- to micrometer-sized surface defects on UV-grade fused silica surfaces are known to be effectively smoothed through the use of high-temperature localized CO{sub 2} laser heating, thereby enhancing optical properties. However, the details of the mass transport and the effect of hydroxyl content on the laser smoothing of defective silica at submicron length scales is still not completely understood. In this study, we examine the morphological evolution of sub-micron, dry-etched periodic surface structures on type II and type III SiO{sub 2} substrates under 10.6 {micro}m CO{sub 2} laser irradiation using atomic force microscopy (AFM). In-situ thermal imaging was used to map the transient temperature field across the heated region, allowing assessment of the T-dependent mass transport mechanisms under different laser-heating conditions. Computational fluid dynamics simulations correlated well with experimental results, and showed that for large effective capillary numbers (N{sub c} > 2), surface diffusion is negligible and smoothing is dictated by capillary action, despite the relatively small spatial scales studied here. Extracted viscosity values over 1700-2000K were higher than the predicted bulk values, but were consistent with the surface depletion of OH groups, which was confirmed using confocal Raman microscopy.

  17. Effect of amorphous C films deposited by RF magnetron sputtering on smoothing K9 glass substrate

    Science.gov (United States)

    Deng, Songwen; Qi, Hongji; Wei, Chaoyang; Yi, Kui; Fan, Zhengxiu; Shao, Jianda

    2009-12-01

    Soft X-ray multilayer reflectors must be deposited on super-smooth surface such as super-polished silicon wafers or glasses, which are complicate, time-consuming and expensive to produce. To overcome this shortage, C films deposited by RF magnetron sputtering were considered to smooth the K9 glass substrates' surface in the present paper. The structure of C films was systematically studied by XRD and Raman spectrum. The surface morphology and rms-roughness were obtained by AFM. Then, we calculated the impact of the C layers on the reflectivity curve of Mo/Si soft X-ray multilayer reflector around 13.5 nm. The C films exhibit typical amorphous state. With the increasing of power and thickness, the content of sp3 hybrid bonding decreases while the amount or size of well-organized graphite clusters increases. The surface rms-roughness decreases from 2.4 nm to 0.62 nm after smoothed by an 80 nm thick C layer deposited in 500 W, which is the smoothest C layer surface we have obtained. The calculation results show that the theoretical normal incidence reflectivity of Mo/Si multilayer at 13.5 nm increases from 7% to 63%.

  18. Kernel Smoothing Methods for Non-Poissonian Seismic Hazard Analysis

    Science.gov (United States)

    Woo, Gordon

    2017-04-01

    For almost fifty years, the mainstay of probabilistic seismic hazard analysis has been the methodology developed by Cornell, which assumes that earthquake occurrence is a Poisson process, and that the spatial distribution of epicentres can be represented by a set of polygonal source zones, within which seismicity is uniform. Based on Vere-Jones' use of kernel smoothing methods for earthquake forecasting, these methods were adapted in 1994 by the author for application to probabilistic seismic hazard analysis. There is no need for ambiguous boundaries of polygonal source zones, nor for the hypothesis of time independence of earthquake sequences. In Europe, there are many regions where seismotectonic zones are not well delineated, and where there is a dynamic stress interaction between events, so that they cannot be described as independent. From the Amatrice earthquake of 24 August, 2016, the subsequent damaging earthquakes in Central Italy over months were not independent events. Removing foreshocks and aftershocks is not only an ill-defined task, it has a material effect on seismic hazard computation. Because of the spatial dispersion of epicentres, and the clustering of magnitudes for the largest events in a sequence, which might all be around magnitude 6, the specific event causing the highest ground motion can vary from one site location to another. Where significant active faults have been clearly identified geologically, they should be modelled as individual seismic sources. The remaining background seismicity should be modelled as non-Poissonian using statistical kernel smoothing methods. This approach was first applied for seismic hazard analysis at a UK nuclear power plant two decades ago, and should be included within logic-trees for future probabilistic seismic hazard at critical installations within Europe. In this paper, various salient European applications are given.

  19. Analytic functions smooth up to the boundary

    CERN Document Server

    1988-01-01

    This research monograph concerns the Nevanlinna factorization of analytic functions smooth, in a sense, up to the boundary. The peculiar properties of such a factorization are investigated for the most common classes of Lipschitz-like analytic functions. The book sets out to create a satisfactory factorization theory as exists for Hardy classes. The reader will find, among other things, the theorem on smoothness for the outer part of a function, the generalization of the theorem of V.P. Havin and F.A. Shamoyan also known in the mathematical lore as the unpublished Carleson-Jacobs theorem, the complete description of the zero-set of analytic functions continuous up to the boundary, generalizing the classical Carleson-Beurling theorem, and the structure of closed ideals in the new wide range of Banach algebras of analytic functions. The first three chapters assume the reader has taken a standard course on one complex variable; the fourth chapter requires supplementary papers cited there. The monograph addresses...

  20. Improved Gait Classification with Different Smoothing Techniques

    Directory of Open Access Journals (Sweden)

    Hu Ng

    2011-01-01

    Full Text Available Gait as a biometric has received great attention nowadays as it can offer human identification at a distance without any contact with the feature capturing device. This is motivated by the increasing number of synchronised closed-circuit television (CCTV cameras which have been installed in many major towns, in order to monitor and prevent crime by identifying the criminal or suspect. This paper present a method to improve gait classification results by applying smoothing techniques on the extracted gait features. The proposed approach is consisted of three parts: extraction of human gait features from enhanced human silhouette, smoothing process on extracted gait features and classification by fuzzy k-nearest neighbours (KNN. The extracted gait features are height, width, crotch height, step-size of the human silhouette and joint trajectories. To improve the recognition rate, two of these extracted gait features are smoothened before the classification process in order to alleviate the effect of outliers. The proposed approach has been applied on a dataset of nine subjects walking bidirectionally on an indoor pathway with twelve different covariate factors. From the experimental results, it can be concluded that the proposed approach is effective in gait classification.

  1. Cortex phellodendri Extract Relaxes Airway Smooth Muscle

    Directory of Open Access Journals (Sweden)

    Qiu-Ju Jiang

    2016-01-01

    Full Text Available Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM; however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component was prepared, which completely inhibits high K+- and acetylcholine- (ACH- induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K+ was also blocked by nifedipine, a selective blocker of L-type Ca2+ channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca2+ channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm.

  2. Smooth Tubercle Bacilli: Neglected Opportunistic Tropical Pathogens

    Directory of Open Access Journals (Sweden)

    Djaltou eAboubaker

    2016-01-01

    Full Text Available Smooth tubercle bacilli (STB including ‘‘Mycobacterium canettii’’ are members of the Mycobacterium tuberculosis complex (MTBC which cause non-contagious tuberculosis in human. This group comprises less than one hundred isolates characterized by smooth colonies and cordless organisms. Most STB isolates have been obtained from patients exposed to the Republic of Djibouti but seven isolates, including the three seminal ones obtained by Georges Canetti between 1968 and 1970, were recovered from patients in France, Madagascar, Sub-Sahara East Africa and French Polynesia. STB form a genetically heterogeneous group of MTBC organisms with large 4.48 ± 0.05 Mb genomes which may link Mycobacterium kansasii to MTBC organisms. Lack of inter-human transmission suggested a yet unknown environmental reservoir. Clinical data indicate a respiratory tract route of contamination and the digestive tract as an alternative route of contamination. Further epidemiological and clinical studies are warranted to elucidate areas of uncertainty regarding these unusual mycobacteria and the tuberculosis they cause.

  3. Differentiation between decomposed remains of human origin and bigger mammals.

    Science.gov (United States)

    Rosier, E; Loix, S; Develter, W; Van de Voorde, W; Cuypers, E; Tytgat, J

    2017-08-01

    This study is a follow-up study in the search for a human specific marker in the decomposition where the VOC-profile of decomposing human, pig, lamb and roe remains were analyzed using a thermal desorber combined with a gas chromatograph coupled to a mass spectrometer in a laboratory environment during 6 months. The combination of 8 previously identified human and pig specific compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, 3-methylthio-1-propanol, methyl(methylthio)ethyl disulfide, diethyl disulfide and pyridine) was also seen in these analyzed mammals. However, combined with 5 additional compounds (hexane, heptane, octane, N-(3-methylbutyl)- and N-(2-methylpropyl)acetamide) human remains could be separated from pig, lamb and roe remains. Based on a higher number of remains analyzed, as compared with the pilot study, it was no longer possible to rely on the 5 previously proposed esters to separate pig from human remains. From this follow-up study reported, it was found that pyridine is an interesting compound specific to human remains. Such a human specific marker can help in the training of cadaver dogs or in the development of devices to search for human remains. However, further investigations have to verify these results. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  4. Original Research: Combined model of bladder detrusor smooth muscle and interstitial cells.

    Science.gov (United States)

    Rosenberg, Josef; Byrtus, Miroslav; Stengl, Milan

    2016-10-01

    Although patients with lower urinary tract symptoms constitute a large and still growing population, understanding of bladder detrusor muscle physiology remains limited. Understanding the interactions between the detrusor smooth muscle cells and other bladder cell types (e.g. interstitial cells, IC) that may significantly contribute to coordinating and modulating detrusor contractions represents a considerable challenge. Computer modeling could help to elucidate some properties that are difficult to address experimentally; therefore, we developed in silico models of detrusor smooth muscle cell and interstitial cells, coupled through gap junctions. The models include all of the major ion conductances and transporters described in smooth muscle cell and interstitial cells in the literature. The model of normal detrusor muscle (smooth muscle cell and interstitial cells coupled through gap junctions) completely reproduced the experimental results obtained with detrusor strips in the presence of several pharmacological interventions (ryanodine, caffeine, nimodipine), whereas the model of smooth muscle cell alone (without interstitial cells) failed to reproduce the experimental results. Next, a model of overactive bladder, a highly prevalent clinical condition in both men and women with increasing incidence at older ages, was produced by modifying several processes as reported previously: a reduction of Ca(2+)-release through ryanodine receptors and a reduction of Ca(2+)-dependent K(+)-conductance with augmented gap junctional coupling. This model was also able to reproduce the pharmacological modulation of overactive bladder. In conclusion, a model of bladder detrusor muscle was developed that reproduced experimental results obtained in both normal and overactive bladder preparations. The results indicate that the non-smooth muscle cells of the detrusor (interstitial cells) contribute significantly to the contractile behavior of bladder detrusor muscle and should not be

  5. The effects of smooth pursuit adaptation on the gain of visuomotor transmission in monkeys

    Directory of Open Access Journals (Sweden)

    Seiji eOno

    2013-12-01

    Full Text Available Smooth pursuit eye movements are supported by visual-motor systems, where visual motion information is transformed into eye movement commands. Adaptation of the visuomotor systems for smooth pursuit is an important factor to maintain pursuit accuracy and high acuity vision. Short-term adaptation of initial pursuit gain can be produced experimentally using by repeated trials of a step-ramp tracking with two different velocities (double-step paradigm that step-up (10–30 °/s or step-down (20–5 °/s. It is also known that visuomotor gain during smooth pursuit is regulated by a dynamic gain control mechanism by showing that eye velocity evoked by a target perturbation during pursuit increases bidirectionally when ongoing pursuit velocity is higher. However, it remains uncertain how smooth pursuit adaptation alters the gain of visuomotor transmission. Therefore, a single cycle of sinusoidal motion (2.5 Hz, ± 10 °/s was introduced during step-ramp tracking pre- and post-adaptation to determine whether smooth pursuit adaptation affects the perturbation response. The results showed that pursuit adaptation had a significant effect on the perturbation response that was specific to the adapted direction. These results indicate that there might be different visuomotor mechanisms between adaptation and dynamic gain control. Furthermore, smooth pursuit adaptation altered not only the gain of the perturbation response, but also the gain slope (regression curve at different target velocities (5, 10 and 15 °/s. Therefore, pursuit adaptation could affect the dynamic regulation of the visuomotor gain at different pursuit velocities.

  6. Evaluation of Stability of Surface-Treated Mini-Implants in Diabetic Rabbits

    Directory of Open Access Journals (Sweden)

    Nam-Hee Oh

    2014-01-01

    Full Text Available Introduction. The purpose of this study was to investigate effects of surface treatment of mini-implants in diabetes-induced rabbits by comparing osseointegration around mini-implants. Methods. Twelve New Zealand white rabbits were divided into two groups (alloxan-induced diabetic group and control group. A total of 48 mini-implants were placed after four weeks of diabetic induction. 24 mini-implants were surface-treated with SLA (sandblasted with large grit, and acid etched and the remaining 24 mini-implants had smooth surfaces. Four weeks after placement, 32 mini-implants were removed from 4 control and 4 diabetic rabbits. Insertion and removal torques were measured. The remaining 16 mini-implants from the two groups were histomorphometrically analyzed. Results. Maximum insertion torque showed no difference between diabetic and control groups, but total insertion energy was higher in control group. In surface-treated mini-implants, maximum removal torque was higher in both diabetic and control groups. Bone-implant contact (BIC was increased in the control group when compared to the diabetic group. Surface-treated group had higher BIC than smooth surface group in both control and diabetic groups. However, there was no significantly statistical difference. Conclusions. Type 1 diabetes mellitus and surface treatment method of mini-implant affected primary stability of mini-implants. In addition, the use of orthodontic mini-implants in a diabetic patient is likely to show results similar to the healthy patient.

  7. Efecto del tamaño kernel en el suavizado de señal BOLD en paradigmas funcionales (RMf (Effect of kernel size for BOLD signal smoothing in functional paradigms (fMRI

    Directory of Open Access Journals (Sweden)

    Laia Farràs-Permanyer

    2015-04-01

    Full Text Available Smoothing is a filtering technique that is essential for brain signal analysis and consists in calculating and comparing the average activation of a voxel to that of its neighbours. Several authors have proposed alternatives or modifications to this process; nonetheless, articles that compare the effect of different sizes of smoothing remain scarce. Thus, the aim of this study was to investigate the effect of applying different smoothing sizes and to highlight the importance of choosing the correct smoothing size. Five smoothing criteria were applied to brain images obtained during an easy motor task performed by five adult participants. Significant differences were found between different smoothing sizes, mainly between the non-smoothing application and the smallest smoothing size versus the two largest smoothing sizes. The signals from the most activated brain areas did not disappear with increased smoothing, whereas signals from less active or smaller areas disappeared. Despite the study sample size, the results suggest that smoothing is relevant in functional magnetic resonance image processing and that the optimum smoothing size is 2.5 and 3.

  8. The taphonomy of human remains in a glacial environment.

    Science.gov (United States)

    Pilloud, Marin A; Megyesi, Mary S; Truffer, Martin; Congram, Derek

    2016-04-01

    A glacial environment is a unique setting that can alter human remains in characteristic ways. This study describes glacial dynamics and how glaciers can be understood as taphonomic agents. Using a case study of human remains recovered from Colony Glacier, Alaska, a glacial taphonomic signature is outlined that includes: (1) movement of remains, (2) dispersal of remains, (3) altered bone margins, (4) splitting of skeletal elements, and (5) extensive soft tissue preservation and adipocere formation. As global glacier area is declining in the current climate, there is the potential for more materials of archaeological and medicolegal significance to be exposed. It is therefore important for the forensic anthropologist to have an idea of the taphonomy in this setting and to be able to differentiate glacial effects from other taphonomic agents. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Attempted Suicide Rates in U.S. Remain Unchanged

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_162339.html Attempted Suicide Rates in U.S. Remain Unchanged Men more often ... HealthDay News) -- The number of Americans who attempted suicide and wound up in the emergency room has ...

  10. A Bayesian Framework for Remaining Useful Life Estimation

    Data.gov (United States)

    National Aeronautics and Space Administration — The estimation of remaining useful life (RUL) of a faulty component is at the center of system prognostics and health management. It gives operators a potent tool in...

  11. [The craniofacial identification of the remains from the Yekaterinburg burial].

    Science.gov (United States)

    Abramov, S S

    1998-01-01

    Based on expert evaluation of remains of 7 members of Imperial Romanov family and 4 persons in their attendance, the author demonstrates methodological approaches to identification craniocephalic studies in cases with group burials.

  12. A modified stanton number for heat transfer through fabric surface

    Directory of Open Access Journals (Sweden)

    Zhang Shen-Zhong

    2015-01-01

    Full Text Available The Stanton number was originally proposed for describing heat transfer through a smooth surface. A modified one is suggested in this paper to take into account non-smooth surface or fractal surface. The emphasis is put on the heat transfer through fabrics.

  13. Indium adhesion provides quantitative measure of surface cleanliness

    Science.gov (United States)

    Krieger, G. L.; Wilson, G. J.

    1968-01-01

    Indium tipped probe measures hydrophobic and hydrophilic contaminants on rough and smooth surfaces. The force needed to pull the indium tip, which adheres to a clean surface, away from the surface provides a quantitative measure of cleanliness.

  14. Repatriation of human remains following death in international travellers.

    Science.gov (United States)

    Connolly, Ruairi; Prendiville, Richard; Cusack, Denis; Flaherty, Gerard

    2017-03-01

    Death during international travel and the repatriation of human remains to one's home country is a distressing and expensive process. Much organization is required involving close liaison between various agencies. A review of the literature was conducted using the PubMed database. Search terms included: 'repatriation of remains', 'death', 'abroad', 'tourism', 'travel', 'travellers', 'travelling' and 'repatriation'. Additional articles were obtained from grey literature sources and reference lists. The local national embassy, travel insurance broker and tour operator are important sources of information to facilitate the repatriation of the deceased traveller. Formal identification of the deceased's remains is required and a funeral director must be appointed. Following this, the coroner in the country or jurisdiction receiving the repatriated remains will require a number of documents prior to providing clearance for burial. Costs involved in repatriating remains must be borne by the family of the deceased although travel insurance may help defray some of the costs. If the death is secondary to an infectious disease, cremation at the site of death is preferred. No standardized procedure is in place to deal with the remains of a migrant's body at present and these remains are often not repatriated to their country of origin. Repatriation of human remains is a difficult task which is emotionally challenging for the bereaving family and friends. As a travel medicine practitioner, it is prudent to discuss all eventualities, including the risk of death, during the pre-travel consultation. Awareness of the procedures involved in this process may ease the burden on the grieving family at a difficult time.

  15. Robotics to Enable Older Adults to Remain Living at Home

    OpenAIRE

    Pearce, Alan J.; Brooke Adair; Kimberly Miller; Elizabeth Ozanne; Catherine Said; Nick Santamaria; Morris, Meg E.

    2012-01-01

    Given the rapidly ageing population, interest is growing in robots to enable older people to remain living at home. We conducted a systematic review and critical evaluation of the scientific literature, from 1990 to the present, on the use of robots in aged care. The key research questions were as follows: (1) what is the range of robotic devices available to enable older people to remain mobile, independent, and safe? and, (2) what is the evidence demonstrating that robotic devices are effec...

  16. Shear flow of dense granular materials near smooth walls. II. Block formation and suppression of slip by rolling friction.

    Science.gov (United States)

    Shojaaee, Zahra; Brendel, Lothar; Török, János; Wolf, Dietrich E

    2012-07-01

    The role of rotational degrees of freedom and of microscopic contact properties at smooth walls in two dimensional planar shear has been investigated by contact dynamics simulations of round hard frictional particles. Our default system setup consists of smooth frictional walls, giving rise to slip. We show that there exists a critical microscopic friction coefficient at the walls, above which they are able to shear the granular medium. We observe distinctive features at this critical point, which to our knowledge have not been reported before. Activating rolling friction at smooth walls reduces slip, leading to similar shear behavior as for rough walls (with particles glued on their surface). Our simulations with rough walls are in agreement with previous results, provided the roughness is strong enough. In the limit of small roughness amplitude, however, the distinctive features of shearing with smooth walls are confirmed.

  17. Dust levitation as a major resurfacing process on the surface of a saturnian icy satellite, Atlas

    Science.gov (United States)

    Hirata, Naoyuki; Miyamoto, Hideaki

    2012-07-01

    A small inner satellite of Saturn, Atlas, has an enigmatic saucer-like shape explained by an accumulation of particles from A-ring of Saturn. However, its unusual smooth surface remains unexplained. Gardening through continuous particle impact events cannot be a unique explanation for the smoothness, because Prometheus does not exhibit a similar surface, though it too would have experienced a similar bombardment. Here, a detailed investigation using close-up images of Atlas reveals the surface to be (1) covered by fine particles (i.e., probably as small as several tens of micrometers); (2) mostly void of impact craters (i.e., only one has been thus far identified); and (3) continuously smooth, even between the equatorial ridge and the undulating polar region. These findings imply that some sort of crater-erasing process has been active on the surface of Atlas. From electro-static analyses, we propose that the upper-most layer of the fine particles can become electro-statically unstable and migrate as a result of dust levitation, which resulted in erasing craters on the surface of Atlas. If true, Atlas would represent the first recognized body where resurfacing is dominated by dust levitation.

  18. A non-destructive method for dating human remains

    Science.gov (United States)

    Lail, Warren K.; Sammeth, David; Mahan, Shannon; Nevins, Jason

    2013-01-01

    The skeletal remains of several Native Americans were recovered in an eroded state from a creek bank in northeastern New Mexico. Subsequently stored in a nearby museum, the remains became lost for almost 36 years. In a recent effort to repatriate the remains, it was necessary to fit them into a cultural chronology in order to determine the appropriate tribe(s) for consultation pursuant to the Native American Grave Protection and Repatriation Act (NAGPRA). Because the remains were found in an eroded context with no artifacts or funerary objects, their age was unknown. Having been asked to avoid destructive dating methods such as radiocarbon dating, the authors used Optically Stimulated Luminescence (OSL) to date the sediments embedded in the cranium. The OSL analyses yielded reliable dates between A.D. 1415 and A.D. 1495. Accordingly, we conclude that the remains were interred somewhat earlier than A.D. 1415, but no later than A.D. 1495. We believe the remains are from individuals ancestral to the Ute Mouache Band, which is now being contacted for repatriation efforts. Not only do our methods contribute to the immediate repatriation efforts, they provide archaeologists with a versatile, non-destructive, numerical dating method that can be used in many burial contexts.

  19. An analysis of the alleged skeletal remains of Carin Goring.

    Directory of Open Access Journals (Sweden)

    Anna Kjellström

    Full Text Available In 1991, treasure hunters found skeletal remains in an area close to the destroyed country residence of former Nazi leader Hermann Göring in northeastern Berlin. The remains, which were believed to belong to Carin Göring, who was buried at the site, were examined to determine whether it was possible to make a positive identification. The anthropological analysis showed that the remains come from an adult woman. The DNA analysis of several bone elements showed female sex, and a reference sample from Carin's son revealed mtDNA sequences identical to the remains. The profile has one nucleotide difference from the Cambridge reference sequence (rCRS, the common variant 263G. A database search resulted in a frequency of this mtDNA sequence of about 10% out of more than 7,000 European haplotypes. The mtDNA sequence found in the ulna, the cranium and the reference sample is, thus, very common among Europeans. Therefore, nuclear DNA analysis was attempted. The remains as well as a sample from Carin's son were successfully analysed for the three nuclear markers TH01, D7S820 and D8S1179. The nuclear DNA analysis of the two samples revealed one shared allele for each of the three markers, supporting a mother and son relationship. This genetic information together with anthropological and historical files provides an additional piece of circumstantial evidence in our efforts to identify the remains of Carin Göring.

  20. Is there a clinical benefit with a smooth compensator design compared with a plunged compensator design for passive scattered protons?

    Energy Technology Data Exchange (ETDEWEB)

    Tabibian, Art A., E-mail: art.tabibian@gmail.com [University of Texas School of Allied Health-Medical Dosimetry, Houston, TX (United States); Powers, Adam; Dolormente, Keith; Oommen, Sneha; Tiwari, Akhil [University of Texas School of Allied Health-Medical Dosimetry, Houston, TX (United States); Palmer, Matt [MD Anderson Department of Radiation Oncology, Houston, TX (United States); Zhu, Xiaorong R.; Li, Heng; Sahoo, Narayan; Wisdom, Paul [MD Anderson Department of Radiation Physics, Houston, TX (United States); Velasco, Kyle [Radiation Oncology Resources, Goshen, IN (United States); Erhart, Kevin; Stanley, Henry [Decimal, Inc, Sanford, FL (United States); Nguyen, Bao-Ngoc T. [MD Anderson Department of Radiation Oncology, Houston, TX (United States)

    2015-04-01

    In proton therapy, passive scattered proton plans use compensators to conform the dose to the distal surface of the planning volume. These devices are custom made from acrylic or wax for each treatment field using either a plunge-drilled or smooth-milled compensator design. The purpose of this study was to investigate if there is a clinical benefit of generating passive scattered proton radiation treatment plans with the smooth compensator design. We generated 4 plans with different techniques using the smooth compensators. We chose 5 sites and 5 patients for each site for the range of dosimetric effects to show adequate sample. The plans were compared and evaluated using multicriteria (MCA) plan quality metrics for plan assessment and comparison using the Quality Reports [EMR] technology by Canis Lupus LLC. The average absolute difference for dosimetric metrics from the plunged-depth plan ranged from −4.7 to +3.0 and the average absolute performance results ranged from −6.6% to +3%. The manually edited smooth compensator plan yielded the best dosimetric metric, +3.0, and performance, + 3.0% compared to the plunged-depth plan. It was also superior to the other smooth compensator plans. Our results indicate that there are multiple approaches to achieve plans with smooth compensators similar to the plunged-depth plans. The smooth compensators with manual compensator edits yielded equal or better target coverage and normal tissue (NT) doses compared with the other smooth compensator techniques. Further studies are under investigation to evaluate the robustness of the smooth compensator design.

  1. ``Clean'' processing of polymers and smoothing of ceramics by pulsed laser melting

    Science.gov (United States)

    Tokarev, V. N.; Marine, W.; Prat, C.; Sentis, M.

    1995-05-01

    Surface stability during laser pulsed melting of polymers and ceramics is studied theoretically. Irradiation conditions and material parameters are found giving rise to the suppression of surface wavy relief of a nonresonant type (with period Λ≫λ, where λ is the radiation wavelength) and thus to the smooth flat irradiation spots. For example, for the polymers considered this process takes place for wavelengths where the absorption coefficient is sufficiently high: α(λ)≳105 cm-1. Thus, it is shown that the formation of such spots, previously referred to as ``clean ablation,'' can be explained using only a thermal mechanism without reference to the concept of ``photodecomposition.'' Moreover, laser smoothing and polishing of a surface, if it had roughness before irradiation, can be achieved by appropriate matching of the characteristic size of this roughness along the surface with the values of α(λ) and laser fluence. Methods are proposed to decrease the parasitic influence of droplets on the deposition of thin films by laser ablation of massive ceramic pellets. The results of theoretical modeling are shown to be in good agreement with experiments on smoothing of rough alumina ceramics and ``clean'' processing of polymers by excimer laser radiation.

  2. A class of Matérn-like covariance functions for smooth processes on a sphere

    KAUST Repository

    Jeong, Jaehong

    2015-02-01

    © 2014 Elsevier Ltd. There have been noticeable advancements in developing parametric covariance models for spatial and spatio-temporal data with various applications to environmental problems. However, literature on covariance models for processes defined on the surface of a sphere with great circle distance as a distance metric is still sparse, due to its mathematical difficulties. It is known that the popular Matérn covariance function, with smoothness parameter greater than 0.5, is not valid for processes on the surface of a sphere with great circle distance. We introduce an approach to produce Matérn-like covariance functions for smooth processes on the surface of a sphere that are valid with great circle distance. The resulting model is isotropic and positive definite on the surface of a sphere with great circle distance, with a natural extension for nonstationarity case. We present extensive numerical comparisons of our model, with a Matérn covariance model using great circle distance as well as chordal distance. We apply our new covariance model class to sea level pressure data, known to be smooth compared to other climate variables, from the CMIP5 climate model outputs.

  3. Analysis of suspected trace human remains from an indoor concrete surface.

    Science.gov (United States)

    Zimmermann, Carolyn M; Laskay, Unige A; Jackson, Glen P

    2008-11-01

    This paper describes the sequence of analyses used to determine the nature of a stain located on the floor of room in the former Athens Mental Health and Retardation Hospital in Athens, OH. The location of the stain was reported to be the position in which a decomposing body was discovered on January 11, 1979. The current stain is found to contain strong evidence for both natural decomposition products and deliberate adulteration. Microscopic analyses, solubility tests, FTIR, ICP-OES, pyrolysis-MS, and derivatization GC-MS were consistent in determining the removable parts of the stain to be composed mostly of calcium and sodium salts of free fatty acids, such as palmitic acid, consistent with previous descriptions of adipocere. The free fatty acids could have been formed via known bacterial degradation pathways or via saponification through the basic environment caused through contact with the concrete. To our knowledge, adipocere formation on an exposed indoor environment has not been described before. The stain and concrete also show signs of being chemically modified with an acidic reagent, such as Blu-Lite--a phosphoric acid-based cleaner that was a commonly used cleaner in the building from the time of discovery to the present day. The chemical etching appears to have been restricted to an area resembling the shape of a human body, which is consistent with deliberate adulteration of the appearance of the stain.

  4. Video tonal stabilization via color states smoothing.

    Science.gov (United States)

    Wang, Yinting; Tao, Dacheng; Li, Xiang; Song, Mingli; Bu, Jiajun; Tan, Ping

    2014-11-01

    We address the problem of removing video color tone jitter that is common in amateur videos recorded with hand-held devices. To achieve this, we introduce color state to represent the exposure and white balance state of a frame. The color state of each frame can be computed by accumulating the color transformations of neighboring frame pairs. Then, the tonal changes of the video can be represented by a time-varying trajectory in color state space. To remove the tone jitter, we smooth the original color state trajectory by solving an L1 optimization problem with PCA dimensionality reduction. In addition, we propose a novel selective strategy to remove small tone jitter while retaining extreme exposure and white balance changes to avoid serious artifacts. Quantitative evaluation and visual comparison with previous work demonstrate the effectiveness of our tonal stabilization method. This system can also be used as a preprocessing tool for other video editing methods.

  5. An analysis of smoothed particle hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Swegle, J.W.; Attaway, S.W.; Heinstein, M.W.; Mello, F.J. [Sandia National Labs., Albuquerque, NM (United States); Hicks, D.L. [Michigan Technological Univ., Houghton, MI (United States)

    1994-03-01

    SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine its applicability in the field of solid dynamics. An important result of the work is a rigorous von Neumann stability analysis which provides a simple criterion for the stability or instability of the method in terms of the stress state and the second derivative of the kernel function. Instability, which typically occurs only for solids in tension, results not from the numerical time integration algorithm, but because the SPH algorithm creates an effective stress with a negative modulus. The analysis provides insight into possible methods for removing the instability. Also, SPH has been coupled into the transient dynamics finite element code PRONTO, and a weighted residual derivation of the SPH equations has been obtained.

  6. SMOOTH TRANSITION LOGISTIC REGRESSION MODEL TREE

    OpenAIRE

    RODRIGO PINTO MOREIRA

    2008-01-01

    Este trabalho tem como objetivo principal adaptar o modelo STR-Tree, o qual é a combinação de um modelo Smooth Transition Regression com Classification and Regression Tree (CART), a fim de utilizá-lo em Classificação. Para isto algumas alterações foram realizadas em sua forma estrutural e na estimação. Devido ao fato de estarmos fazendo classificação de variáveis dependentes binárias, se faz necessária a utilização das técnicas empregadas em Regressão Logística, dessa forma a estimação dos pa...

  7. Resolving mixing in Smoothed Particle Hydrodynamics

    CERN Document Server

    Read, J I; Agertz, O

    2009-01-01

    Standard formulations of smoothed particle hydrodynamics (SPH) are unable to resolve mixing at fluid boundaries. We use an error and stability analysis of the generalised SPH equations of motion to prove that this is due to two distinct problems. The first is a leading order error in the momentum equation. This should decrease with increasing neighbour number, but does not because numerical instabilities cause the kernel to be irregularly sampled. We identify two important instabilities: the clumping instability and the banding instability, and we show that both are cured by a suitable choice of kernel. The second problem is the local mixing instability (LMI). This occurs as particles attempt to mix on the kernel scale, but are unable to due to entropy conservation. The result is a pressure discontinuity at boundaries that pushes fluids of different entropy apart. We cure the LMI by using a temperature weighted density estimate that both reduces errors in the continuity equation and allows individual particle...

  8. PV output smoothing with energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Abraham; Schoenwald, David Alan

    2012-03-01

    This report describes an algorithm, implemented in Matlab/Simulink, designed to reduce the variability of photovoltaic (PV) power output by using a battery. The purpose of the battery is to add power to the PV output (or subtract) to smooth out the high frequency components of the PV power that that occur during periods with transient cloud shadows on the PV array. The control system is challenged with the task of reducing short-term PV output variability while avoiding overworking the battery both in terms of capacity and ramp capability. The algorithm proposed by Sandia is purposely very simple to facilitate implementation in a real-time controller. The control structure has two additional inputs to which the battery can respond. For example, the battery could respond to PV variability, load variability or area control error (ACE) or a combination of the three.

  9. The Smooth-Coated Otter in Nepal

    Directory of Open Access Journals (Sweden)

    Houghton S.J.

    1987-03-01

    Full Text Available This study has shown that the Smooth-coated otter is common along the length of the Naryani river and that it relies heavily on fish. It also suggests their feeding habits are sufficiently flexible to adapt to local variations in their food supply. A comparison of river banks suggests human activities decrease the availability of suitable habitat and over-fishing decreases food supply. Extensive deforestation in the hills causes flooding and increases the turbidity of the lowland changing both the aquatic environment and the river's topography. Pollution, resulting from chemical discharge is increasingly an important problem in Nepal. Without an effective management plan controlling these, those animal species dependent on the riverine system may rapidly decrease in number or even disappear permanently.

  10. Adaptively Smoothed Seismicity Earthquake Forecasts for Italy

    CERN Document Server

    Werner, M J; Jackson, D D; Kagan, Y Y; Wiemer, S

    2010-01-01

    We present a model for estimating the probabilities of future earthquakes of magnitudes m > 4.95 in Italy. The model, a slightly modified version of the one proposed for California by Helmstetter et al. (2007) and Werner et al. (2010), approximates seismicity by a spatially heterogeneous, temporally homogeneous Poisson point process. The temporal, spatial and magnitude dimensions are entirely decoupled. Magnitudes are independently and identically distributed according to a tapered Gutenberg-Richter magnitude distribution. We estimated the spatial distribution of future seismicity by smoothing the locations of past earthquakes listed in two Italian catalogs: a short instrumental catalog and a longer instrumental and historical catalog. The bandwidth of the adaptive spatial kernel is estimated by optimizing the predictive power of the kernel estimate of the spatial earthquake density in retrospective forecasts. When available and trustworthy, we used small earthquakes m>2.95 to illuminate active fault structur...

  11. On Clustering Criteria for Smooth Distributions

    CERN Document Server

    Bharath, Karthik; Dey, Dipak K

    2012-01-01

    We develop a clustering framework, motivated by the problem of testing for jumps in continuous-time stochastic process models, and derive its asymptotic properties under a general setup. Our technique is applicable whenever we have data from a population with a smooth distribution function. We then propose an intuitive and easily verifiable clustering criterion, based on the Empirical Cross-over Function, which provides us with the requisite tools to develop a test for the presence of jumps. We illustrate the validity of our theory on the popular Merton and Kou models for asset pricing with the objective of investigating jumps occurring in these models as a phenomena which leads to the formation of clusters.

  12. Smoothness monitors for compressible flow computation

    Energy Technology Data Exchange (ETDEWEB)

    Sjogreen, B; Yee, H C

    2008-09-02

    In [SY04, YS07] and references cited therein, the authors introduced the concept of employing multiresolution wavelet decomposition of computed flow data as smoothness monitors (flow sensors) to indicate the amount and location of built-in numerical dissipation that can be eliminated or further reduced in shock-capturing schemes. Studies indicated that this approach is able to limit the use of numerical dissipation with improved accuracy compared with standard shock-capturing methods. The studies in [SY04, YS07] were limited to low order multiresolution redundant wavelets with low level supports and low order vanishing moments. The objective of this paper is to expand the previous investigation to include higher order redundant wavelets with larger support and higher order vanishing moments for a wider spectrum of flow type and flow speed applications.

  13. The giant impact simulations with density independent smoothed particle hydrodynamics

    Science.gov (United States)

    Hosono, Natsuki; Saitoh, Takayuki R.; Makino, Junichiro; Genda, Hidenori; Ida, Shigeru

    2016-06-01

    At present, the giant impact (GI) is the most widely accepted model for the origin of the Moon. Most of the numerical simulations of GI have been carried out with the smoothed particle hydrodynamics (SPH) method. Recently, however, it has been pointed out that standard formulation of SPH (SSPH) has difficulties in the treatment of a contact discontinuity such as a core-mantle boundary and a free surface such as a planetary surface. This difficulty comes from the assumption of differentiability of density in SSPH. We have developed an alternative formulation of SPH, density independent SPH (DISPH), which is based on differentiability of pressure instead of density to solve the problem of a contact discontinuity. In this paper, we report the results of the GI simulations with DISPH and compare them with those obtained with SSPH. We found that the disk properties, such as mass and angular momentum produced by DISPH is different from that of SSPH. In general, the disks formed by DISPH are more compact: while formation of a smaller mass moon for low-oblique impacts is expected with DISPH, inhibition of ejection would promote formation of a larger mass moon for high-oblique impacts. Since only the improvement of core-mantle boundary significantly affects the properties of circumplanetary disks generated by GI and DISPH has not been significantly improved from SSPH for a free surface, we should be very careful when some conclusions are drawn from the numerical simulations for GI. And it is necessary to develop the numerical hydrodynamical scheme for GI that can properly treat the free surface as well as the contact discontinuity.

  14. Modeling of current distribution on smooth and columnar platinum structures.

    Science.gov (United States)

    Zinola, Carlos F

    2011-01-17

    Studying the growth and stability of anisotropic or isotropic disordered surfaces in electrodeposition is of importance in catalytic electrochemistry. In some cases, the metallic nature of the electrode defines the topography and roughness, which are also controlled by the experimental time and applied external potential. Because of the experimental restrictions in conventional electrochemical techniques and ex situ electron microscopies, a theoretical model of the surface geometry could aid in understanding the electrodeposition process and current distributions. In spite of applying a complex theory such as dynamic scaling method or perturbation theories, the resolution of mixed mass-/charge-transfer equations (tertiary distribution) for the electrodeposition process would give reliable information. One of the main problems with this type of distribution is the mathematics when solving the spatial n-dimensional differential equations. Use of a primary current distribution is proposed here to simplify the differential equations; however it limits wide application of the first assumption. Distributions of concentration profile, current density, and electrode potential are presented here as a function of the distance normal to the surface for the cases of smooth and rough platinum growth. In the particular case of columnar surfaces, cycloid curves are used to model the electrode, from which the concentration profile is presented in a parameterized form after solving a first-type curvilinear integral. The concentration contour results in a combination of a trigonometric inverse function and a linear distribution leading to a negative concavity curve. The calculation of the current density and electrode potential contours also show trigonometric shapes exhibiting forbidden imaginary values only at the minimal values of the trochoid curve.

  15. The Giant Impact Simulations with Density Independent Smoothed Particle Hydrodynamics

    CERN Document Server

    Hosono, Natsuki; Makino, Junichiro; Genda, Hidenori; Ida, Shigeru

    2016-01-01

    At present, the giant impact (GI) is the most widely accepted model for the origin of the Moon. Most of the numerical simulations of GI have been carried out with the smoothed particle hydrodynamics (SPH) method. Recently, however, it has been pointed out that standard formulation of SPH (SSPH) has difficulties in the treatment of a contact discontinuity such as a core-mantle boundary and a free surface such as a planetary surface. This difficulty comes from the assumption of differentiability of density in SSPH. We have developed an alternative formulation of SPH, density independent SPH (DISPH), which is based on differentiability of pressure instead of density to solve the problem of a contact discontinuity. In this paper, we report the results of the GI simulations with DISPH and compare them with those obtained with SSPH. We found that the disk properties, such as mass and angular momentum produced by DISPH is different from that of SSPH. In general, the disks formed by DISPH are more compact: while form...

  16. Forensic considerations when dealing with incinerated human dental remains.

    Science.gov (United States)

    Reesu, Gowri Vijay; Augustine, Jeyaseelan; Urs, Aadithya B

    2015-01-01

    Establishing the human dental identification process relies upon sufficient post-mortem data being recovered to allow for a meaningful comparison with ante-mortem records of the deceased person. Teeth are the most indestructible components of the human body and are structurally unique in their composition. They possess the highest resistance to most environmental effects like fire, desiccation, decomposition and prolonged immersion. In most natural as well as man-made disasters, teeth may provide the only means of positive identification of an otherwise unrecognizable body. It is imperative that dental evidence should not be destroyed through erroneous handling until appropriate radiographs, photographs, or impressions can be fabricated. Proper methods of physical stabilization of incinerated human dental remains should be followed. The maintenance of integrity of extremely fragile structures is crucial to the successful confirmation of identity. In such situations, the forensic dentist must stabilise these teeth before the fragile remains are transported to the mortuary to ensure preservation of possibly vital identification evidence. Thus, while dealing with any incinerated dental remains, a systematic approach must be followed through each stage of evaluation of incinerated dental remains to prevent the loss of potential dental evidence. This paper presents a composite review of various studies on incinerated human dental remains and discusses their impact on the process of human identification and suggests a step by step approach. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  17. Anisotropic Smoothing Improves DT-MRI-Based Muscle Fiber Tractography.

    Directory of Open Access Journals (Sweden)

    Amanda K W Buck

    Full Text Available To assess the effect of anisotropic smoothing on fiber tracking measures, including pennation angle, fiber tract length, and fiber tract number in the medial gastrocnemius (MG muscle in healthy subjects using diffusion-weighted magnetic resonance imaging (DW-MRI.3T DW-MRI data were used for muscle fiber tractography in the MG of healthy subjects. Anisotropic smoothing was applied at three levels (5%, 10%, 15%, and pennation angle, tract length, fiber tract number, fractional anisotropy, and principal eigenvector orientation were quantified for each smoothing level.Fiber tract length increased with pre-fiber tracking smoothing, and local heterogeneities in fiber direction were reduced. However, pennation angle was not affected by smoothing.Modest anisotropic smoothing (10% improved fiber-tracking results, while preserving structural features.

  18. Image segmentation on adaptive edge-preserving smoothing

    Science.gov (United States)

    He, Kun; Wang, Dan; Zheng, Xiuqing

    2016-09-01

    Nowadays, typical active contour models are widely applied in image segmentation. However, they perform badly on real images with inhomogeneous subregions. In order to overcome the drawback, this paper proposes an edge-preserving smoothing image segmentation algorithm. At first, this paper analyzes the edge-preserving smoothing conditions for image segmentation and constructs an edge-preserving smoothing model inspired by total variation. The proposed model has the ability to smooth inhomogeneous subregions and preserve edges. Then, a kind of clustering algorithm, which reasonably trades off edge-preserving and subregion-smoothing according to the local information, is employed to learn the edge-preserving parameter adaptively. At last, according to the confidence level of segmentation subregions, this paper constructs a smoothing convergence condition to avoid oversmoothing. Experiments indicate that the proposed algorithm has superior performance in precision, recall, and F-measure compared with other segmentation algorithms, and it is insensitive to noise and inhomogeneous-regions.

  19. Characterization of the volatile organic compounds present in the headspace of decomposing animal remains, and compared with human remains.

    Science.gov (United States)

    Cablk, Mary E; Szelagowski, Erin E; Sagebiel, John C

    2012-07-10

    Human Remains Detection (HRD) dogs can be a useful tool to locate buried human remains because they rely on olfactory rather than visual cues. Trained specifically to locate deceased humans, it is widely believed that HRD dogs can differentiate animal remains from human remains. This study analyzed the volatile organic compounds (VOCs) present in the headspace above partially decomposed animal tissue samples and directly compared them with results published from human tissues using established solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) methods. Volatile organic compounds present in the headspace of four different animal tissue samples (bone, muscle, fat and skin) from each of cow, pig and chicken were identified and compared to published results from human samples. Although there were compounds common to both animal and human remains, the VOC signatures of each of the animal remains differed from those of humans. Of particular interest was the difference between pigs and humans, because in some countries HRD dogs are trained on pig remains rather than human remains. Pig VOC signatures were not found to be a subset of human; in addition to sharing only seven of thirty human-specific compounds, an additional nine unique VOCs were recorded from pig samples which were not present in human samples. The VOC signatures from chicken and human samples were most similar sharing the most compounds of the animals studied. Identifying VOCs that are unique to humans may be useful to develop human-specific training aids for HRD canines, and may eventually lead to an instrument that can detect clandestine human burial sites. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  20. Distinct function of estrogen receptor α in smooth muscle and fibroblast cells in prostate development.

    Science.gov (United States)

    Vitkus, Spencer; Yeh, Chiuan-Ren; Lin, Hsiu-Hsia; Hsu, Iawen; Yu, Jiangzhou; Chen, Ming; Yeh, Shuyuan

    2013-01-01

    Estrogen signaling, through estrogen receptor (ER)α, has been shown to cause hypertrophy in the prostate. Our recent report has shown that epithelial ERα knockout (KO) will not affect the normal prostate development or homeostasis. However, it remains unclear whether ERα in different types of stromal cells has distinct roles in prostate development. This study proposed to elucidate how KO of ERα in the stromal smooth muscle or fibroblast cells may interrupt cross talk between prostate stromal and epithelial cells. Smooth muscle ERαKO (smERαKO) mice showed decreased glandular infolding with the proximal area exhibiting a significant decrease. Fibroblast ERαKO mouse prostates did not exhibit this phenotype but showed a decrease in the number of ductal tips. Additionally, the amount of collagen observed in the basement membrane was reduced in smERαKO prostates. Interestingly, these phenotypes were found to be mutually exclusive among smERαKO or fibroblast ERαKO mice. Compound KO of ERα in both fibroblast and smooth muscle showed combined phenotypes from each of the single KO. Further mechanistic studies showed that IGF-I and epidermal growth factor were down-regulated in prostate smooth muscle PS-1 cells lacking ERα. Together, our results indicate the distinct functions of fibroblast vs. smERα in prostate development.

  1. Arterial wall mechanics as a function of heart rate: role of vascular smooth muscle

    Energy Technology Data Exchange (ETDEWEB)

    Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel [Facultad de Ingenieria y Ciencias Exactas y Naturales, Universidad Favaloro Av. Belgrano 1723 - Buenos Aires (Argentina)

    2007-11-15

    Vascular wall viscoelasticity can be evaluated using a first-order lumped model. This model consists of a spring with elastic constant E and a dashpot with viscous constant {eta}. More importantly, this viscoelastic model can be fitted in-vivo measuring arterial pressure and diameter. The aim of this work is to analyze the influence of heart rate over E and {eta}. In two anesthetized sheep, diameter in thoracic aorta and intravascular pressure has been registered. The right atrium was connected to a programmable stimulator through a pair of pace-maker wires to produce changes in stimulation heart rate (HR) from 80 to 160 bpm. Additionally, local activation of vascular smooth muscle was induced with phenylephrine. After converting pressure and diameter signals into stress and strain respectively, E y {eta} were calculated in control state and during muscle activation. The elastic modulus E did not present significant changes with heart rate. The viscous modulus {eta} decreased 49% with a two-fold acceleration in heart rate from 80 to 160 bpm. However, the product {eta} HR remained stable. The viscous modulus {eta} increased 39% with smooth muscle activation. No significant pressure changes were registered during the experiment. The contractile action of vascular smooth muscle could contribute to increasing arterial wall viscosity. The decrease of {eta} when HR increased might be related to smooth muscle relaxation mediated by endothelium activity, which was stimulated by flow increase. We conclude that HR can modulate arterial wall viscoelasticity through endothelium-dependent mechanisms.

  2. Cutmarked human remains bearing Neandertal features and modern human remains associated with the Aurignacian at Les Rois.

    Science.gov (United States)

    Ramirez Rozzi, Fernando V; d'Errico, Francesco; Vanhaeren, Marian; Grootes, Pieter M; Kerautret, Bertrand; Dujardin, Véronique

    2009-01-01

    The view that Aurignacian technologies and their associated symbolic manifestations represent the archaeologicalproxy for the spread of Anatomically Modern Humans into Europe, is supported by few diagnostic human remains, including those from the Aurignacian site of Les Rois in south-western France. Here we reassess the taxonomic attribution of the human remains, their cultural affiliation, and provide five new radiocarbon dates for the site. Patterns of tooth growth along with the morphological and morphometric analysis of the human remains indicate that a juvenile mandible showing cutmarks presents some Neandertal features, whereas another mandible is attributed to Anatomically Modern Humans. Reappraisal of the archaeological sequence demonstrates that human remains derive from two layers dated to 28-30 kyr BP attributed to the Aurignacian, the only cultural tradition detected at the site. Three possible explanations may account for this unexpected evidence. The first one is that the Aurignacian was exclusively produced by AMH and that the child mandible from unit A2 represents evidence for consumption or, more likely, symbolic use of a Neandertal child by Aurignacian AMH The second possible explanation is that Aurignacian technologies were produced at Les Rois by human groups bearing both AMH and Neandertal features. Human remains from Les Rois would be in this case the first evidence of a biological contact between the two human groups. The third possibility is that all human remains from Les Rois represent an AMH population with conserved plesiomorphic characters suggesting a larger variation in modern humans from the Upper Palaeolithic.

  3. Do nanofill or submicron composites show improved smoothness and gloss? A systematic review of in vitro studies

    NARCIS (Netherlands)

    Kaizer, M.R.; Oliveira-Ogliari, A. de; Cenci, M.S.; Opdam, N.J.M.; Moraes, R.R.

    2014-01-01

    OBJECTIVES: Despite nanofill and submicron composites' aim to provide high initial polishing combined with superior smoothness and gloss retention, the question still remains whether clinicians should consider using these new materials over traditional microhybrids. The aim of this paper was to syst

  4. Caveolin-3 promotes a vascular smooth muscle contractile phenotype

    Directory of Open Access Journals (Sweden)

    Jorge L. Gutierrez-Pajares

    2015-06-01

    Full Text Available Epidemiological studies have demonstrated the importance of cardiovascular diseases in Western countries. Among the cell types associated with a dysfunctional vasculature, smooth muscle cells are believed to play an essential role in the development of these illnesses. Vascular smooth muscle cells are key regulators of the vascular tone and also have an important function in the development of atherosclerosis and restenosis. While in the normal vasculature contractile smooth muscle cells are predominant, in atherosclerotic vascular lesions, synthetic cells migrate toward the neointima, proliferate, and synthetize extracellular matrix proteins. In the present study, we have examined the role of caveolin-3 in the regulation of smooth muscle cell phenotype. Caveolin-3 is expressed in vivo in normal arterial smooth muscle cells, but its expression appears to be lost in cultured smooth muscle cells. Our data show that caveolin-3 expression in the A7r5 smooth muscle cell line is associated with increased expression of contractility markers such as smooth muscle  actin, smooth muscle myosin heavy chain but decreased expression of the synthetic phenotype markers such as p-Elk and Klf4. Moreover, we also show that caveolin-3 expression can reduce proliferation upon treatment with LDL or PDGF. Finally, we show that caveolin-3-expressing smooth muscle cells are less sensitive to apoptosis than control cells upon treatment with oxidized LDL. Taken together, our data suggest that caveolin-3 can regulate the phenotypic switch between contractile and synthetic smooth muscle cells. A better understanding of the factors regulating caveolin-3 expression and function in this cell type will permit the development of a better comprehension of the factors regulating smooth muscle function in atherosclerosis and restenosis.

  5. Changes of smooth muscle contractile filaments in small bowel atresia

    OpenAIRE

    Gfrörer, Stefan; Fiegel, Henning; Ramachandran, Priya; Rolle, Udo; Metzger, Roman

    2012-01-01

    AIM: To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients. METHODS: Resected small bowel specimens from small bowel atresia patients (n = 12) were divided into three sections (proximal, atretic and distal). Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proxi...

  6. Six-term exact sequences for smooth generalized crossed products

    DEFF Research Database (Denmark)

    Gabriel, Olivier; Grensing, Martin

    2013-01-01

    We define smooth generalized crossed products and prove six-term exact sequences of Pimsner–Voiculescu type. This sequence may, in particular, be applied to smooth subalgebras of the quantum Heisenberg manifolds in order to compute the generators of their cyclic cohomology. Further, our results i...... include the known results for smooth crossed products. Our proof is based on a combination of arguments from the setting of (Cuntz–)Pimsner algebras and the Toeplitz proof of Bott periodicity....

  7. Classification of pelvic ring fractures in skeletonized human remains.

    Science.gov (United States)

    Báez-Molgado, Socorro; Bartelink, Eric J; Jellema, Lyman M; Spurlock, Linda; Sholts, Sabrina B

    2015-01-01

    Pelvic ring fractures are associated with high rates of mortality and thus can provide key information about circumstances surrounding death. These injuries can be particularly informative in skeletonized remains, yet difficult to diagnose and interpret. This study adapted a clinical system of classifying pelvic ring fractures according to their resultant degree of pelvic stability for application to gross human skeletal remains. The modified Tile criteria were applied to the skeletal remains of 22 individuals from the Cleveland Museum of Natural History and Universidad Nacional Autónoma de México that displayed evidence of pelvic injury. Because these categories are tied directly to clinical assessments concerning the severity and treatment of injuries, this approach can aid in the identification of manner and cause of death, as well as interpretations of possible mechanisms of injury, such as those typical in car-to-pedestrian and motor vehicle accidents. © 2014 American Academy of Forensic Sciences.

  8. Microscopic residues of bone from dissolving human remains in acids.

    Science.gov (United States)

    Vermeij, Erwin; Zoon, Peter; van Wijk, Mayonne; Gerretsen, Reza

    2015-05-01

    Dissolving bodies is a current method of disposing of human remains and has been practiced throughout the years. During the last decade in the Netherlands, two cases have emerged in which human remains were treated with acid. In the first case, the remains of a cremated body were treated with hydrofluoric acid. In the second case, two complete bodies were dissolved in a mixture of hydrochloric and sulfuric acid. In both cases, a great variety of evidence was collected at the scene of crime, part of which was embedded in resin, polished, and investigated using SEM/EDX. Apart from macroscopic findings like residual bone and artificial teeth, in both cases, distinct microscopic residues of bone were found as follows: (partly) digested bone, thin-walled structures, and recrystallized calcium phosphate. Although some may believe it is possible to dissolve a body in acid completely, at least some of these microscopic residues will always be found. © 2015 American Academy of Forensic Sciences.

  9. Ebola vaccine 2014:remained problems to be answered

    Institute of Scientific and Technical Information of China (English)

    Somsri; Wiwanitkit; Viroj; Wiwanitkit

    2015-01-01

    Ebola virus outbreak in Africa in 2014 is a big global issue.The vaccine is the hope for management of the present outbreak of Ebola virus infection.There are several ongoing researches on new Ebola vaccine.In this short manuscript,we discuss and put forward specific remained problems to be answered on this specific issue.Lack for complete knowledge on the new emerging virus,concern from pharmaceutical company and good trial of new vaccine candidates are the remained problem to be further discussed in vaccinology.

  10. On random age and remaining lifetime for populations of items

    DEFF Research Database (Denmark)

    Finkelstein, M.; Vaupel, J.

    2015-01-01

    We consider items that are incepted into operation having already a random (initial) age and define the corresponding remaining lifetime. We show that these lifetimes are identically distributed when the age distribution is equal to the equilibrium distribution of the renewal theory. Then we...... develop the population studies approach to the problem and generalize the setting in terms of stationary and stable populations of items. We obtain new stochastic comparisons for the corresponding population ages and remaining lifetimes that can be useful in applications. Copyright (c) 2014 John Wiley...

  11. Changes of smooth muscle contractile filaments in small bowel atresia

    Institute of Scientific and Technical Information of China (English)

    Stefan Gfroerer; Henning Fiegel; Priya Ramachandran; Udo Rolle; Roman Metzger

    2012-01-01

    AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients (n =12) were divided into three sections (proximal,atretic and distal).Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proximal and distal bowel.Small bowel from agematched patients (n =2) undergoing Meckel's diverticulum resection served as controls.RESULTS:The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue,but the distal bowel was unchanged.Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue.There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel.The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.CONCLUSION:Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.

  12. Oxygen concentration control of dopamine-induced high uniformity surface coating chemistry.

    Science.gov (United States)

    Kim, Hyo Won; McCloskey, Bryan D; Choi, Tae Hwan; Lee, Changho; Kim, Min-Joung; Freeman, Benny D; Park, Ho Bum

    2013-01-23

    Material surface engineering has attracted great interest in important applications, including electronics, biomedicine, and membranes. More recently, dopamine has been widely exploited in solution-based chemistry to direct facile surface modification. However, unsolved questions remain about the chemical identity of the final products, their deposition kinetics and their binding mechanism. In particular, the dopamine oxidation reaction kinetics is a key to improving surface modification efficiency. Here, we demonstrate that high O(2) concentrations in the dopamine solution lead to highly homogeneous, thin layer deposition on any material surfaces via accelerated reaction kinetics, elucidated by Le Chatelier's principle toward dopamine oxidation steps in a Michael-addition reaction. As a result, highly uniform, ultra-smooth modified surfaces are achieved in much shorter deposition times. This finding provides new insights into the effect of reaction kinetics and molecular geometry on the uniformity of modifications for surface engineering techniques.

  13. Chaotic behaviour from smooth and non-smooth optical solitons under external perturbation

    Indian Academy of Sciences (India)

    LIUWEI ZHAO; JIULI YIN

    2016-08-01

    Smooth and non-smooth optical solitons in the nonlinearly dispersive Schrödinger equation are given by phase portraits. The Melnikov technique is used to detect conditions for chaotic motion of this deterministic system and to analyse conditions for the suppression of chaos. Our results show that the system is in a state of Melnikov chaos by external disturbances. After the implementation of the controlled system, the optical solitons can transmit in a stable station for a long time. Numerical simulation also shows that maximum interference frequency of the system enables the dynamic behaviour to be more complex. The effect of controller parameter on phase portraits as well as on the numerical simulations of bifurcation diagram and maximum Lyapunov exponents are also investigated.

  14. Smooth Contractive Embeddings and Application to Feynman Formula for Parabolic Equations on Smooth Bounded Domains

    CERN Document Server

    Baur, Benedict; Grothaus, Martin

    2010-01-01

    We prove two assumptions made in an article by Ya.A. Butko, M. Grothaus, O.G. Smolyanov concerning the existence of a strongly continuous operator semigroup solving a Cauchy-Dirichlet problem for an elliptic differential operator in a bounded domain and the existence of a smooth contractive embedding of a core of the generator of the semigroup into the space $C_c^{2,\\alpha}(\\R^n)$. Based on these assumptions a Feynman formula for the solution of the Cauchy-Dirichlet problem is constructed in the article mentioned above. In this article we show that the assumptions are fulfilled for domains with $C^{4,\\alpha}$-smooth boundary and coefficients in $C^{2,\\alpha}$.

  15. Facile preparation of smooth perovskite films for efficient meso/planar hybrid structured perovskite solar cells.

    Science.gov (United States)

    Zhang, Meng; Yu, Hua; Yun, Jung-Ho; Lyu, Miaoqiang; Wang, Qiong; Wang, Lianzhou

    2015-06-21

    Smooth organolead halide perovskite films for meso/planar hybrid structured perovskite solar cells were prepared by a simple compressed air blow-drying method under ambient conditions. The resultant perovskite films show high surface coverage, leading to a device power conversion efficiency of over 10% with an open circuit voltage up to 1.003 V merely using pristine poly(3-hexylthiophene) (P3HT) as a hole transporter.

  16. An α-smooth muscle actin (acta2/αsma) zebrafish transgenic line marking vascular mural cells and visceral smooth muscle cells.

    Science.gov (United States)

    Whitesell, Thomas R; Kennedy, Regan M; Carter, Alyson D; Rollins, Evvi-Lynn; Georgijevic, Sonja; Santoro, Massimo M; Childs, Sarah J

    2014-01-01

    Mural cells of the vascular system include vascular smooth muscle cells (SMCs) and pericytes whose role is to stabilize and/or provide contractility to blood vessels. One of the earliest markers of mural cell development in vertebrates is α smooth muscle actin (acta2; αsma), which is expressed by pericytes and SMCs. In vivo models of vascular mural cell development in zebrafish are currently lacking, therefore we developed two transgenic zebrafish lines driving expression of GFP or mCherry in acta2-expressing cells. These transgenic fish were used to trace the live development of mural cells in embryonic and larval transgenic zebrafish. acta2:EGFP transgenic animals show expression that largely mirrors native acta2 expression, with early pan-muscle expression starting at 24 hpf in the heart muscle, followed by skeletal and visceral muscle. At 3.5 dpf, expression in the bulbus arteriosus and ventral aorta marks the first expression in vascular smooth muscle. Over the next 10 days of development, the number of acta2:EGFP positive cells and the number of types of blood vessels associated with mural cells increases. Interestingly, the mural cells are not motile and remain in the same position once they express the acta2:EGFP transgene. Taken together, our data suggests that zebrafish mural cells develop relatively late, and have little mobility once they associate with vessels.

  17. An α-smooth muscle actin (acta2/αsma zebrafish transgenic line marking vascular mural cells and visceral smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Thomas R Whitesell

    Full Text Available Mural cells of the vascular system include vascular smooth muscle cells (SMCs and pericytes whose role is to stabilize and/or provide contractility to blood vessels. One of the earliest markers of mural cell development in vertebrates is α smooth muscle actin (acta2; αsma, which is expressed by pericytes and SMCs. In vivo models of vascular mural cell development in zebrafish are currently lacking, therefore we developed two transgenic zebrafish lines driving expression of GFP or mCherry in acta2-expressing cells. These transgenic fish were used to trace the live development of mural cells in embryonic and larval transgenic zebrafish. acta2:EGFP transgenic animals show expression that largely mirrors native acta2 expression, with early pan-muscle expression starting at 24 hpf in the heart muscle, followed by skeletal and visceral muscle. At 3.5 dpf, expression in the bulbus arteriosus and ventral aorta marks the first expression in vascular smooth muscle. Over the next 10 days of development, the number of acta2:EGFP positive cells and the number of types of blood vessels associated with mural cells increases. Interestingly, the mural cells are not motile and remain in the same position once they express the acta2:EGFP transgene. Taken together, our data suggests that zebrafish mural cells develop relatively late, and have little mobility once they associate with vessels.

  18. The Existence of Smooth Densities for the Prediction, Filtering and Smoothing Problems

    Science.gov (United States)

    1990-12-20

    d’une equation differentielle stochastique avec semi-martingale directrice discontinue, Sem. dc Probabilit~s XIX. Lecture notes in Math. 1123...Proceedings of Internatiional Coinference. Kyoto. 1976 Wiley. 1978, 195-263. (1l] 1P A Meyer, Hlot d’une equation differentielle stochaistiquc...smoothing and, prediction problems. Stochastic flows are also used to derive minimum principles in stochastic control, and new equations for the

  19. A Study on Generic Representation of Skeletal Remains Replication of Prehistoric Burial

    Science.gov (United States)

    Shao, C.-W.; Chiu, H.-L.; Chang, S.-K.

    2015-08-01

    Generic representation of skeletal remains from burials consists of three dimensions which include physical anthropologists, replication technicians, and promotional educators. For the reason that archaeological excavation is irreversible and disruptive, detail documentation and replication technologies are surely needed for many purposes. Unearthed bones during the process of 3D digital scanning need to go through reverse procedure, 3D scanning, digital model superimposition, rapid prototyping, mould making, and the integrated errors generated from the presentation of colours and textures are important issues for the presentation of replicate skeleton remains among professional decisions conducted by physical anthropologists, subjective determination of makers, and the expectations of viewers. This study presents several cases and examines current issues on display and replication technologies for human skeletal remains of prehistoric burials. This study documented detail colour changes of human skeleton over time for the reference of reproduction. The tolerance errors of quantification and required technical qualification is acquired according to the precision of 3D scanning, the specification requirement of rapid prototyping machine, and the mould making process should following the professional requirement for physical anthropological study. Additionally, the colorimeter is adopted to record and analyse the "colour change" of the human skeletal remains from wet to dry condition. Then, the "colure change" is used to evaluate the "real" surface texture and colour presentation of human skeletal remains, and to limit the artistic presentation among the human skeletal remains reproduction. The"Lingdao man No.1", is a well preserved burial of early Neolithic period (8300 B.P.) excavated from Liangdao-Daowei site, Matsu, Taiwan , as the replicating object for this study. In this study, we examined the reproduction procedures step by step for ensuring the surface

  20. Neanderthal infant and adult infracranial remains from Marillac (Charente, France).

    Science.gov (United States)

    Dolores Garralda, María; Maureille, Bruno; Vandermeersch, Bernard

    2014-09-01

    At the site of Marillac, near the Ligonne River in Marillac-le-Franc (Charente, France), a remarkable stratigraphic sequence has yielded a wealth of archaeological information, palaeoenvironmental data, as well as faunal and human remains. Marillac must have been a sinkhole used by Neanderthal groups as a hunting camp during MIS 4 (TL date 57,600 ± 4,600BP), where Quina Mousterian lithics and fragmented bones of reindeer predominate. This article describes three infracranial skeleton fragments. Two of them are from adults and consist of the incomplete shafts of a right radius (Marillac 24) and a left fibula (Marillac 26). The third fragment is the diaphysis of the right femur of an immature individual (Marillac 25), the size and shape of which resembles those from Teshik-Tash and could be assigned to a child of a similar age. The three fossils have been compared with the remains of other Neanderthals or anatomically Modern Humans (AMH). Furthermore, the comparison of the infantile femora, Marillac 25 and Teshik-Tash, with the remains of several European children from the early Middle Ages clearly demonstrates the robustness and rounded shape of both Neanderthal diaphyses. Evidence of peri-mortem manipulations have been identified on all three bones, with spiral fractures, percussion pits and, in the case of the radius and femur, unquestionable cutmarks made with flint implements, probably during defleshing. Traces of periostosis appear on the fibula fragment and on the immature femoral diaphysis, although their aetiology remains unknown.