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Sample records for bps wall crossing

  1. BPS Spectra, Barcodes and Walls

    CERN Document Server

    Cirafici, Michele

    2015-01-01

    BPS spectra give important insights into the non-perturbative regimes of supersymmetric theories. Often from the study of BPS states one can infer properties of the geometrical or algebraic structures underlying such theories. In this paper we approach this problem from the perspective of persistent homology. Persistent homology is at the base of topological data analysis, which aims at extracting topological features out of a set of points. We use these techniques to investigate the topological properties which characterize the spectra of several supersymmetric models in field and string theory. We discuss how such features change upon crossing walls of marginal stability in a few examples. Then we look at the topological properties of the distributions of BPS invariants in string compactifications on compact threefolds, used to engineer black hole microstates. Finally we discuss the interplay between persistent homology and modularity by considering certain number theoretical functions used to count dyons i...

  2. Wall Crossing of BPS States on the Conifold from Seiberg Duality and Pyramid Partitions

    CERN Document Server

    Chuang, Wu-yen

    2008-01-01

    In this paper we study the relation between pyramid partitions with a general empty room configuration (ERC) and the BPS states of D-branes on the resolved conifold. We find that the generating function for pyramid partitions with a length n ERC is exactly the same as the D6/D2/D0 BPS partition function on the resolved conifold in particular Kaehler chambers. We define a new type of pyramid partition with a finite ERC that counts the BPS degeneracies in certain other chambers. The D6/D2/D0 partition functions in different chambers were obtained by applying the wall crossing formula. On the other hand, the pyramid partitions describe $T^3$ fixed points of the moduli space of a quiver quantum mechanics. This quiver arises after we apply Seiberg dualities to the D6/D2/D0 system on the conifold and choose a particular set of FI parameters. The arrow structure of the dual quiver is confirmed by computation of the Ext group between the sheaves. We show that the superpotential and the stability condition of the dual...

  3. BPS state counting using wall-crossing, holomorphic anomalies and modularity

    Energy Technology Data Exchange (ETDEWEB)

    Wotschke, Thomas

    2013-05-15

    In this thesis we examine the counting of BPS states using wall-crossing, holomorphic anomalies and modularity. We count BPS states that arise in two setups: multiple M5-branes wrapping P x T{sup 2}, where P denotes a divisor inside a Calabi-Yau threefold and topological string theory on elliptic Calabi-Yau threefolds. The first setup has a dual description as type IIA string theory via a D4-D2-D0 brane system. Furthermore it leads to two descriptions depending on the size of P and T{sup 2} relative to each other. For the case of a small divisor P this setup is described by the (0,4) Maldacena-Strominger-Witten conformal field theory of a black hole in M-theory and for the case of small T{sup 2} the setup can by described by N=4 topological Yang-Mills theory on P. The BPS states are counted by the modified elliptic genus, which can be decomposed into a vector-valued modular form that provides the generating function for the BPS invariants and a Siegel-Narain theta function. In the first part we discuss the holomorphic anomaly of the modified elliptic genus for the case of two M5-branes and divisors with b{sup +}{sub 2}(P)=1. Due to the wall-crossing effect the change in the generating function is captured by an indefinite theta function, which is a mock modular form. We use the Kontsevich-Soibelman wall-crossing formula to determine the jumps in the modified elliptic genus. Using the regularisation procedure for mock modular forms of Zwegers, modularity can be restored at the cost of holomorphicity. We show that the non-holomorphic completion is due to bound states of single M5-branes. At the attractor point in the moduli space we prove the holomorphic anomaly equation, which is compatible with the holomorphic anomaly equations observed in the context of N=4 Yang-Mills theory on P{sup 2} and E-strings on a del Pezzo surface. We calculate the generating functions of BPS invariants for the divisors P{sup 2}, F{sub 0}, F{sub 1} and the del Pezzo surface dP{sub 8} and

  4. BPS state counting using wall-crossing, holomorphic anomalies and modularity

    International Nuclear Information System (INIS)

    In this thesis we examine the counting of BPS states using wall-crossing, holomorphic anomalies and modularity. We count BPS states that arise in two setups: multiple M5-branes wrapping P x T2, where P denotes a divisor inside a Calabi-Yau threefold and topological string theory on elliptic Calabi-Yau threefolds. The first setup has a dual description as type IIA string theory via a D4-D2-D0 brane system. Furthermore it leads to two descriptions depending on the size of P and T2 relative to each other. For the case of a small divisor P this setup is described by the (0,4) Maldacena-Strominger-Witten conformal field theory of a black hole in M-theory and for the case of small T2 the setup can by described by N=4 topological Yang-Mills theory on P. The BPS states are counted by the modified elliptic genus, which can be decomposed into a vector-valued modular form that provides the generating function for the BPS invariants and a Siegel-Narain theta function. In the first part we discuss the holomorphic anomaly of the modified elliptic genus for the case of two M5-branes and divisors with b+2(P)=1. Due to the wall-crossing effect the change in the generating function is captured by an indefinite theta function, which is a mock modular form. We use the Kontsevich-Soibelman wall-crossing formula to determine the jumps in the modified elliptic genus. Using the regularisation procedure for mock modular forms of Zwegers, modularity can be restored at the cost of holomorphicity. We show that the non-holomorphic completion is due to bound states of single M5-branes. At the attractor point in the moduli space we prove the holomorphic anomaly equation, which is compatible with the holomorphic anomaly equations observed in the context of N=4 Yang-Mills theory on P2 and E-strings on a del Pezzo surface. We calculate the generating functions of BPS invariants for the divisors P2, F0, F1 and the del Pezzo surface dP8 and dP9 ((1)/(2) K3). In the second part we study the quantum

  5. BPS domain walls from backreacted orientifolds

    CERN Document Server

    Blåbäck, Johan; Van Riet, Thomas; Vercnocke, Bert

    2013-01-01

    Compactifications with D-brane and orientifold sources lead to standard gauged supergravity theories if the sources are smeared over the internal directions. It is therefore of interest to find how the solutions described by the gauged supergravity are altered by properly localising the sources. In this paper we analyse this for BPS domain wall solutions in the seven-dimensional gauged supergravity obtained from an O6 toroidal orientifold compactification in massive IIA supergravity. This is one of the simplest no-scale supergravities that can be constructed and analysed in full detail. We find and discuss the BPS domain walls both when the O6 planes are smeared and localised. When the O6 planes are localised the domain wall solutions live in a warped compactification. In order to get explicit expressions we also consider the non-compact versions of the solutions for which the O6 planes have been traded for D6 branes. Through T-duality we obtain partially localised solutions for compactifications to four dime...

  6. Global structure of moduli space for BPS walls

    International Nuclear Information System (INIS)

    We study the global structure of the moduli space of BPS walls in the Higgs branch of supersymmetric theories with eight supercharges. We examine the structure in the neighborhood of a special Lagrangian submanifold M, and find that the dimension of the moduli space can be larger than that naively suggested by the index theorem, contrary to previous examples of BPS solitons. We investigate BPS wall solutions in an explicit example of M using Abelian gauge theory. Its Higgs branch turns out to contain several special Lagrangian submanifolds including M. We show that the total moduli space of BPS walls is the union of these submanifolds. We also find interesting dynamics between BPS walls as a by-product of the analysis. Namely, mutual repulsion and attraction between BPS walls sometimes forbid a movement of a wall and lock it in a certain position; we also find that a pair of walls can transmute to another pair of walls with different tension after they pass through

  7. Exact BPS domain walls at finite gauge coupling

    CERN Document Server

    Blaschke, Filip

    2016-01-01

    Bogomol'nyi-Prasad-Sommerfield solitons in models with spontaneously broken gauge symmetry have been intensively studied at infinite gauge coupling limit, where the governing equation -- so-called master equation -- is exactly solvable. Except of handful of special solutions, the standing impression is that analytic results at finite coupling are generally unavailable. The aim of this paper is to demonstrate, using domain walls in Abelian-Higgs models as a simplest example, that exact solitons at finite gauge coupling can be readily obtained, if the number of Higgs fields ($N_F$) is large enough. In particular, we present a family of exact solutions, describing $N$ domain walls at arbitrary positions in models with at least $N_F \\geq 2N+1$. We have also found that adding together any pair of solution can produce a new exact solution, if the combined tension is below certain limit.

  8. Wall-crossing made smooth

    CERN Document Server

    Pioline, Boris

    2015-01-01

    In $D=4,N=2$ theories on $R^{3,1}$, the index receives contributions not only from single-particle BPS states, counted by the BPS indices, but also from multi-particle states made of BPS constituents. In a recent work [arXiv:1406.2360], a general formula expressing the index in terms of the BPS indices was proposed, which is smooth across walls of marginal stability and reproduces the expected single-particle contributions. In this note, I analyze the two-particle contributions predicted by this formula, and show agreement with the spectral asymmetry of the continuum of scattering states in the supersymmetric quantum mechanics of two non-relativistic, mutually non-local dyons. This provides a physical justification for the error function profile used in the mathematics literature on indefinite theta series, and in the physics literature on black hole partition functions.

  9. Semiclassical framed BPS states

    CERN Document Server

    Moore, Gregory W; Bleeken, Dieter Van den

    2015-01-01

    We provide a semiclassical description of framed BPS states in four-dimensional N = 2 super Yang-Mills theories probed by 't Hooft defects, in terms of a supersymmetric quantum mechanics on the moduli space of singular monopoles. Framed BPS states, like their ordinary counterparts in the theory without defects, are associated with the L^2 kernel of certain Dirac operators on moduli space, or equivalently with the L^2 cohomology of related Dolbeault operators. The Dirac/Dolbeault operators depend on two Cartan-valued Higgs vevs. We conjecture a map between these vevs and the Seiberg-Witten special coordinates, consistent with a one-loop analysis and checked in examples. The map incorporates all perturbative and nonperturbative corrections that are relevant for the semiclassical construction of BPS states, over a suitably defined weak coupling regime of the Coulomb branch. We use this map to translate wall crossing formulae and the no exotics theorem to statements about the Dirac/Dolbeault operators. The no exo...

  10. BPS Domain Walls in super Yang-Mills and Landau-Ginzburg models

    International Nuclear Information System (INIS)

    We study domain walls in two different extensions of super Yang-Mills characterized by the absence of a logarithmic term in their effective superpotential. The models, defined by the usual gaugino condensate and an extra field Y, give different patterns of domain walls despite both leading to the same effective limit for heavy Y, i.e. the Veneziano-Yankielowicz effective Lagrangian of super Yang-Mills. We explain the origin of those differences and also give a physical motivation for introducing the field Y. (author)

  11. BPS spectrum of Argyres-Douglas theory via spectral network

    CERN Document Server

    Maruyoshi, Kazunobu; Yan, Wenbin

    2013-01-01

    We study the BPS spectrum of four-dimensional N=2 superconformal field theory of Argyres-Douglas type, obtained via twisted compactification of six-dimensional A_{N-1} (2,0) theory on a sphere with an irregular puncture, by using spectral networks. We give strong evidence of the equivalence of N=2 superconformal field theories from six-dimensional theories of different ranks by systematically comparing the chamber structure and wall-crossing phenomena.

  12. Quantum Black Holes, Wall Crossing, and Mock Modular Forms

    CERN Document Server

    Dabholkar, Atish; Zagier, Don

    2012-01-01

    We show that the meromorphic Jacobi form that counts the quarter-BPS states in N=4 string theories can be canonically decomposed as a sum of a mock Jacobi form and an Appell-Lerch sum. The quantum degeneracies of single-centered black holes are Fourier coefficients of this mock Jacobi form, while the Appell-Lerch sum captures the degeneracies of multi-centered black holes which decay upon wall-crossing. The completion of the mock Jacobi form restores the modular symmetries expected from $AdS_3/CFT_2$ holography but has a holomorphic anomaly reflecting the non-compactness of the microscopic CFT. For every positive integral value m of the magnetic charge invariant of the black hole, our analysis leads to a special mock Jacobi form of weight two and index m, which we characterize uniquely up to a Jacobi cusp form. This family of special forms and another closely related family of weight-one forms contain almost all the known mock modular forms including the mock theta functions of Ramanujan, the generating funct...

  13. Wall-Crossing Holomorphic Anomaly and Mock Modularity of Multiple M5-Branes

    Science.gov (United States)

    Alim, Murad; Haghighat, Babak; Hecht, Michael; Klemm, Albrecht; Rauch, Marco; Wotschke, Thomas

    2015-11-01

    Using wall-crossing formulae and the theory of mock modular forms we derive a holomorphic anomaly equation for the modified elliptic genus of two M5-branes wrapping a rigid divisor inside a Calabi-Yau manifold. The anomaly originates from restoring modularity of an indefinite theta-function capturing the wall-crossing of BPS invariants associated to D4-D2-D0 brane systems. We show the compatibility of this equation with anomaly equations previously observed in the context of topological Yang-Mills theory on and E-strings obtained from wrapping M5-branes on a del Pezzo surface. The non-holomorphic part is related to the contribution originating from bound-states of singly wrapped M5-branes on the divisor. We show in examples that the information provided by the anomaly is enough to compute the BPS degeneracies for certain charges. We further speculate on a natural extension of the anomaly to higher D4-brane charge.

  14. Knots, BPS States, and Algebraic Curves

    Science.gov (United States)

    Garoufalidis, Stavros; Kucharski, Piotr; Sułkowski, Piotr

    2016-08-01

    We analyze relations between BPS degeneracies related to Labastida-Mariño-Ooguri-Vafa (LMOV) invariants and algebraic curves associated to knots. We introduce a new class of such curves, which we call extremal A-polynomials, discuss their special properties, and determine exact and asymptotic formulas for the corresponding (extremal) BPS degeneracies. These formulas lead to nontrivial integrality statements in number theory, as well as to an improved integrality conjecture, which is stronger than the known M-theory integrality predictions. Furthermore, we determine the BPS degeneracies encoded in augmentation polynomials and show their consistency with known colored HOMFLY polynomials. Finally, we consider refined BPS degeneracies for knots, determine them from the knowledge of super-A-polynomials, and verify their integrality. We illustrate our results with twist knots, torus knots, and various other knots with up to 10 crossings.

  15. Sequencing BPS Spectra

    CERN Document Server

    Gukov, Sergei; Saberi, Ingmar; Stosic, Marko; Sulkowski, Piotr

    2015-01-01

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincar\\'e polynomials in numerous examples. Among these structural properties is a novel "sliding" property, which can be explained by using (refined) modular $S$-matrix. This leads to the identifi...

  16. Argyres-Douglas Loci, Singularity Structures and Wall-Crossings in Pure N=2 Gauge Theories with Classical Gauge Groups

    CERN Document Server

    Seo, Jihye

    2012-01-01

    N=2 Seiberg-Witten theories allow an interesting interplay between the Argyres-Douglas loci, singularity structures and wall-crossing formulae. In this paper we investigate this connection by first studying the singularity structures of hyper-elliptic Seiberg-Witten curves for pure N=2 gauge theories with SU(r+1) and Sp(2r) gauge groups, and propose new methods to locate the Argyres-Douglas loci in the moduli space, where multiple mutually non-local BPS states become massless. In a region of the moduli space, we compute dyon charges for all 2r+2 and 2r+1 massless dyons for SU(r+1) and Sp(2r) gauge groups respectively for rank r>1. From here we elucidate the connection to the wall-crossing phenomena for pure Sp(4) Seiberg-Witten theory near the Argyres-Douglas loci, despite our emphasis being only at the massless sector of the BPS spectra. We also present 2r-1 candidates for the maximal Argyres-Douglas points for pure SO(2r+1) Seiberg-Witten theory.

  17. Gravitating BPS Skyrmions

    CERN Document Server

    Gudnason, Sven Bjarke; Sawado, Nobuyuki

    2015-01-01

    The BPS Skyrme model has many exact analytic solutions in flat space. We generalize the model to a curved space or spacetime and find that the solutions can only be BPS for a constant time-time component of the metric tensor. We find exact solutions on the curved spaces: a 3-sphere and a 3-hyperboloid; and we further find an analytic gravitating Skyrmion on the 3-sphere. For the case of a nontrivial time-time component of the metric, we suggest a potential for which we find analytic solutions on anti-de Sitter and de Sitter spacetimes in the limit of no gravitational backreaction. We take the gravitational coupling into account in numerical solutions and show that they are well approximated by the analytic solutions for weak gravitational coupling.

  18. Wall-Crossing in Genus Zero Landau-Ginzburg Theory

    OpenAIRE

    Ross, Dustin; Ruan, Yongbin

    2014-01-01

    We study genus zero wall-crossing for a family of moduli spaces introduced recently by Fan-Farvis-Ruan. The family has a wall and chamber structure relative to a positive rational parameter. For a Fermat quasi-homogeneous polynomial W (not necessarily Calabi-Yau type), we study natural generating functions of invariants associated to these moduli spaces. Our wall-crossing formula relates the generating functions by showing that they all lie on the same Lagrangian cone associated to the Fan-Ja...

  19. Time-Dependent BPS Skyrmions

    CERN Document Server

    Ioannidou, Theodora

    2016-01-01

    An extended version of the BPS Skyrme model that admits time-dependent solutions is discussed. Initially, by introducing a power law at the original potential term of the BPS Skyrme model the existence, stability and structure of the corresponding solutions is investigated. Then, the frequencies and half-lifes of the radial oscillations of the constructed time-dependent solutions are determined.

  20. Non-perturbative effects and wall-crossing from topological strings

    International Nuclear Information System (INIS)

    We argue that the Gopakumar-Vafa interpretation of the topological string partition function can be used to compute and resum certain non-perturbative brane instanton effects of type II CY compactifications. In particular the topological string A-model encodes the non-perturbative corrections to the hypermultiplet moduli space metric from general D1/D(-1)-brane instantons in 4d N = 2 IIB models. We also discuss the reduction to 4d N = 1 by fluxes and/or orientifolds and/or D-branes, and the prospects to resum brane instanton contributions to non-perturbative superpotentials. We argue that the connection between non-perturbative effects and the topological string underlies the continuity of non-perturbative effects across lines of BPS stability. We also confirm this statement in mirror B-model matrix model examples, relating matrix model instantons to non-perturbative D-brane instantons. The computation of non-perturbative effects from the topological string requires a 3d circle compactification and T-duality, relating effects from particles and instantons, reminiscent of that involved in the physical derivation of the Kontsevich-Soibelmann wall-crossing formula.

  1. Superfluid properties of BPS monopoles

    CERN Document Server

    Lantsman, L

    2006-01-01

    This paper is devoted to demonstrating manifest superfluid properties of the Minkowskian Higgs model with vacuum BPS monopole solutions at assuming the "continuous" $\\sim S^2$ vacuum geometry in that model. It will be also argued that point hedgehog topological defects are present in the Minkowskian Higgs model with BPS monopoles. It turns out, and we show this, that the enumerated phenomena are compatible with the Faddeev-Popov "heuristic" quantization of the Minkowskian Higgs model with vacuum BPS monopoles, coming to fixing the Weyl (temporal) gauge $A_0=0$ for gauge fields $A$ in the Faddeev-Popov path integral.

  2. Analytic continuation of a parametric polytope and wall-crossing

    CERN Document Server

    Berline, Nicole

    2011-01-01

    We define a set theoretic "analytic continuation" of a polytope defined by inequalities. For the regular values of the parameter, our construction coincides with the parallel transport of polytopes in a mirage introduced by Varchenko. We determine the set-theoretic variation when crossing a wall in the parameter space, and we relate this variation to Paradan's wall-crossing formulas for integrals and discrete sums. As another application, we refine the theorem of Brion on generating functions of polytopes and their cones at vertices. We describe the relation of this work with the equivariant index of a line bundle over a toric variety and Morelli constructible support function.

  3. Connecting Localization and Wall-Crossing via D-Branes

    CERN Document Server

    Chang, Chih-Kai; Jain, Dharmesh; Lee, Norton

    2015-01-01

    We demonstrate explicitly that the vacuum expectation values (vevs) of BPS line operators in 4d N=2 super Yang-Mills theory compactified on a circle, computed by localization techniques, can be expanded in terms of Darboux coordinates as proposed by Gaiotto, Moore, and Neitzke [arXiv:1006.0146]. However, we need to refine the expansion by including additional novel monopole bubbling contributions to obtain a precise match. Using D-brane realization of these singular BPS line operators, we derive and incorporate the monopole bubbling contributions as well as predict the degeneracies of framed BPS states contributing to the line operator vevs in the limit of vanishing simultaneous spatial and R-symmetry rotation fugacity parameter.

  4. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  5. Radial vibrations of BPS skyrmions

    CERN Document Server

    Adam, C; Romanczukiewicz, T; Wereszczynski, A

    2016-01-01

    We study radial vibrations of spherically symmetric skyrmions in the BPS Skyrme model. Concretely, we numerically solve the linearised field equations for small fluctuations in a skyrmion background, both for linearly stable oscillations and for (unstable) resonances. This is complemented by numerical solutions of the full nonlinear system, which confirm all the results of the linear analysis. In all cases, the resulting fundamental excitation provides a rather accurate value for the Roper resonance, supporting the hypothesis that the BPS Skyrme model already gives a reasonable approximate description of this resonance.

  6. The vector BPS Skyrme model

    OpenAIRE

    Adam, C.; C. Naya; Sanchez-Guillen, J.; Wereszczynski, A.

    2012-01-01

    We analyze the vector meson formulation of the BPS Skyrme model in (3+1) dimensions, where the term of sixth power in first derivatives characteristic for the original, integrable BPS Skyrme model (the topological or baryon current squared) is replaced by a coupling between the vector meson $\\omega_\\mu$ and the baryon current. We find that the model remains integrable in the sense of generalized integrability and almost solvable (reducible to a set of two first order ODEs) for any value of th...

  7. Gravitating BPS dyons witout a dilaton

    CERN Document Server

    Lee, C; Lee, Choonkyu; Park, Q Han

    1996-01-01

    We describe curved-space BPS dyon solutions, the ADM mass of which saturates the gravitational version of the Bogomol'nyi bound. This generalizes self-gravitating BPS monopole solutions of Gibbons et al. when there is no dilaton.

  8. The vector BPS Skyrme model

    CERN Document Server

    Adam, C; Sanchez-Guillen, J; Wereszczynski, A

    2012-01-01

    We analyze the vector meson formulation of the BPS Skyrme model in (3+1) dimensions, where the term of sixth power in first derivatives characteristic for the original, integrable BPS Skyrme model (the topological or baryon current squared) is replaced by a coupling between the vector meson $\\omega_\\mu$ and the baryon current. We find that the model remains integrable in the sense of generalized integrability and almost solvable (reducible to a set of two first order ODEs) for any value of the baryon charge. Further, we analyze the appearance of topological solitons for two one-parameter families of one vacuum potentials: the old Skyrme potentials and the so-called BPS potentials. Depending on the value of the parameters we find several qualitatively different possibilities. In the massless case we have a parameter region with no skyrmions, a unique compact skyrmion with a discontinuous first derivative at the boundary (equivalently, with a source term located at the boundary, which screens the topological ch...

  9. BPS Skyrmions as neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Adam, C., E-mail: adam@fpaxp1.usc.es [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Naya, C.; Sanchez-Guillen, J.; Vazquez, R. [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Reymonta 4, Kraków (Poland)

    2015-03-06

    The BPS Skyrme model has been demonstrated already to provide a physically intriguing and quantitatively reliable description of nuclear matter. Indeed, the model has both the symmetries and the energy–momentum tensor of a perfect fluid, and thus represents a field theoretic realization of the “liquid droplet” model of nuclear matter. In addition, the classical soliton solutions together with some obvious corrections (spin–isospin quantization, Coulomb energy, proton-neutron mass difference) provide an accurate modeling of nuclear binding energies for heavier nuclei. These results lead to the rather natural proposal to try to describe also neutron stars by the BPS Skyrme model coupled to gravity. We find that the resulting self-gravitating BPS Skyrmions provide excellent results as well as some new perspectives for the description of bulk properties of neutron stars when the parameter values of the model are extracted from nuclear physics. Specifically, the maximum possible mass of a neutron star before black-hole formation sets in is a few solar masses, the precise value of which depends on the precise values of the model parameters, and the resulting neutron star radius is of the order of 10 km.

  10. Theta Series, Wall-Crossing and Quantum Dilogarithm Identities

    Science.gov (United States)

    Alexandrov, Sergei; Pioline, Boris

    2016-08-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with N=2 supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from k Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge k. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm {Φ_b} at b = 1, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary b and k, which may be relevant for the physics of five-branes at finite chemical potential for angular momentum.

  11. Theta series, wall-crossing and quantum dilogarithm identities

    CERN Document Server

    Alexandrov, Sergei

    2015-01-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with N=2 supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from $k$ Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge $k$. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm $\\Phi_b$ at $b=1$, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary $b$ and $k$, which may be relevant for the physics of five-branes at finite chemical po...

  12. Wall Crossing Invariants: from quantum mechanics to knots

    CERN Document Server

    Galakhov, D; Morozov, A

    2014-01-01

    We offer a pedestrian level review of the wall-crossing invariants. The story begins from the scattering theory in quantum mechanics where the spectrum reshuffling can be related to permutations of S-matrices. In non-trivial situations, starting from spin chains and matrix models, the S-matrices are operator-valued and their algebra is described in terms of R- and mixing (Racah) U-matrices. Then, the Kontsevich-Soibelman invariants are nothing but the standard knot invariants made out of these data within the Reshetikhin-Turaev-Witten approach. The R- and Racah matrices acquire a relatively universal form in the quasiclassical limit, where the basic reshufflings with the change of moduli are those of the Stokes line. Natural from this point of view are matrices provided by the modular transformations of conformal blocks (with the usual identification R=T and U=S), and in the simplest case of the first degenerate field (2,1), when the conformal blocks satisfy a second order Shroedinger-like equation, the invar...

  13. Theta Series, Wall-Crossing and Quantum Dilogarithm Identities

    Science.gov (United States)

    Alexandrov, Sergei; Pioline, Boris

    2016-05-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with {{{N}=2}} supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from k Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge k. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm {Φ_b} at b = 1, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary b and k, which may be relevant for the physics of five-branes at finite chemical potential for angular momentum.

  14. Multiply Phased Traveling BPS Vortex

    CERN Document Server

    Kimm, Kyoungtae; Cho, Y M

    2016-01-01

    We present the multiply phased current carrying vortex solutions in the U(1) gauge theory coupled to an $(N+1)$-component SU(N+1) scalar multiplet in the Bogomolny limit. Our vortex solutions correspond to the static vortex dressed with traveling waves along the axis of symmetry. What is notable in our vortex solutions is that the frequencies of traveling waves in each component of the scalar field can have different values. The energy of the static vortex is proportional to the topological charge of $CP^N$ model in the BPS limit, and the multiple phase of the vortex supplies additional energy contribution which is proportional to the Noether charge associated to the remaining symmetry.

  15. Cell wall antibiotics provoke accumulation of anchored mCherry in the cross wall of Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Wenqi Yu

    Full Text Available A fluorescence microscopy method to directly follow the localization of defined proteins in Staphylococcus was hampered by the unstable fluorescence of fluorescent proteins. Here, we constructed plasmid (pCX encoded red fluorescence (RF mCherry (mCh hybrids, namely mCh-cyto (no signal peptide and no sorting sequence, mCh-sec (with signal peptide, and mCh-cw (with signal peptide and cell wall sorting sequence. The S. aureus clones targeted mCh-fusion proteins into the cytosol, the supernatant and the cell envelope respectively; in all cases mCherry exhibited bright fluorescence. In staphylococci two types of signal peptides (SP can be distinguished: the +YSIRK motif SP(lip and the -YSIRK motif SP(sasF. mCh-hybrids supplied with the +YSIRK motif SP(lip were always expressed higher than those with -YSIRK motif SP(sasF. To study the location of the anchoring process and also the influence of SP type, mCh-cw was supplied on the one hand with +YSIRK motif (mCh-cw1 and the other hand with -YSIRK motif (mCh-cw2. MCh-cw1 preferentially localized at the cross wall, while mCh-cw2 preferentially localized at the peripheral wall. Interestingly, when treated with sub-lethal concentrations of penicillin or moenomycin, both mCh-cw1 and mCh-cw2 were concentrated at the cross wall. The shift from the peripheral wall to the cross wall required Sortase A (SrtA, as in the srtA mutant this effect was blunted. The effect is most likely due to antibiotic mediated increase of free anchoring sites (Lipid II at the cross wall, the substrate of SrtA, leading to a preferential incorporation of anchored proteins at the cross wall.

  16. Analysis of moderately thin-walled beam cross-sections by cubic isoparametric elements

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2014-01-01

    numerically by introducing a cubic-linear two-dimensional isoparametric element. The cubic interpolation of this element accurately represents quadratic shear stress variations along cross-section walls, and thus moderately thin-walled cross-sections are effectively discretized by these elements. The ability...... of this element to represent curved geometries, and to accurately determine cross-section parameters and shear stress distributions is demonstrated....

  17. BPS Boojums in N=2 supersymmetric gauge theories

    CERN Document Server

    Arai, Masato; Eto, Minoru

    2016-01-01

    We study 1/4 Bogomol'nyi-Prasad-Sommerfield (BPS) composite solitons of vortex strings, domain walls and boojums in N=2 supersymmetric Abelian gauge theories in four dimensions. We obtain solutions to the 1/4 BPS equations with the finite gauge coupling constant. To obtain numerical solutions for generic coupling constants, we construct globally correct approximate functions which allow us to easily find fixed points of a gradient flow equations. We analytically/numerically confirm that the negative mass of a single boojum appearing at the end point of the vortex string on the logarithmically bent domain wall is equal to the half-mass of the 't Hooft-Polyakov monopole. We examine various configurations and clarify how the shape of the boojum depends on the coupling constants and moduli parameters. We find a semi-local boojum with a size moduli which appears when the semi-local string ends on the domain wall. We introduce a magnetic scalar potential which offers an intuitive understanding that the end point of...

  18. An E9 multiplet of BPS states

    International Nuclear Information System (INIS)

    We construct an infinite E9 multiplet of BPS states for 11D supergravity. For each positive real root of E9 we obtain a BPS solution of 11D supergravity, or of its exotic counterparts, depending on two non-compact transverse space variables. All these solutions are related by U-dualities realised via E9 Weyl transformations in the regular embedding E9-E10-E11. In this way we recover the basic BPS solutions, namely the KK-wave, the M2 brane, the M5 brane and the KK6-monopole, as well as other solutions admitting eight longitudinal space dimensions. A novel technique of combining Weyl reflexions with compensating transformations allows the construction of many new BPS solutions, each of which can be mapped to a solution of a dual effective action of gravity coupled to a certain higher rank tensor field not contained in 11D supergravity. For real roots of E10 which are not roots of E9, we obtain additional BPS solutions transcending 11D supergravity (as exemplified by the lowest level solution corresponding to the M9 brane). The relation between the dual formulation and the one in terms of the original 11D supergravity fields has significance beyond the realm of BPS solutions. We establish the link with the Geroch group of general relativity, and explain how the E9 duality transformations generalize the standard Hodge dualities to an infinite set of 'non-closing dualities'

  19. In-vitro fermentability of cell walls as influenced by lignin composition and cross-linking.

    Science.gov (United States)

    We assessed how diverse modifications in lignin composition and reductions in ferulate-lignin cross-linking influence the degradability of cell walls. Cell walls from nonlignified maize cell suspensions were artificially lignified with varying ratios of normal monolignols (coniferyl and sinapyl alco...

  20. Near BPS Skyrmions and Restricted Harmonic Maps

    CERN Document Server

    Speight, J M

    2014-01-01

    Motivated by a class of near BPS Skyrme models introduced by Adam, S\\'anchez-Guill\\'en and Wereszczy\\'nski, the following variant of the harmonic map problem is introduced: a map $\\phi:(M,g)\\rightarrow (N,h)$ between Riemannian manifolds is restricted harmonic (RH) if it locally extremizes $E_2$ on its $SDiff(M)$ orbit, where $SDiff(M)$ denotes the group of volume preserving diffeomorphisms of $(M,g)$, and $E_2$ denotes the Dirichlet energy. It is conjectured that near BPS skyrmions tend to RH maps in the BPS limit. It is shown that $\\phi$ is RH if and only if $\\phi^*h$ has exact divergence, and a linear stability theory of RH maps is developed, whence it follows that all weakly conformal maps, for example, are stable RH. Examples of RH maps in every degree class $R^3\\to SU(2)$ and $R^2\\to S^2$ are constructed. It is shown that the axially symmetric BPS skyrmions on which all previous analytic studies of near BPS Skyrme models have been based, are not RH, so each such field can be deformed along $SDiff(R^3)$ ...

  1. Multi-BPS D-vortices

    CERN Document Server

    Cho, Inyong; Kim, Yoonbai

    2008-01-01

    We investigate the BPS configuration of the multi D-vortices produced from the D2${\\bar {\\rm D}}$2 system. Based on the DBI-type action with a Gaussian-type runaway potential for a complex tachyon field, the BPS limit is achieved when the tachyon profile is thin. The solution states randomly-distributed $n$ static D-vortices with zero interaction. With the obtained BPS configuration, we derive the relativistic Lagrangian which describes the dynamics of free massive D-vortices. We also discuss the 90${}^{\\circ}$ and 180${}^{\\circ}$ scattering of two identical D-vortices, and present its implications on the reconnection in the dynamics of cosmic superstrings.

  2. Near BPS skyrmions and restricted harmonic maps

    Science.gov (United States)

    Speight, J. M.

    2015-06-01

    Motivated by a class of near BPS Skyrme models introduced by Adam, Sánchez-Guillén and Wereszczyński, the following variant of the harmonic map problem is introduced: a map φ :(M, g) →(N, h) between Riemannian manifolds is restricted harmonic if it locally extremizes E2 on its SDiff(M) orbit, where SDiff(M) denotes the group of volume preserving diffeomorphisms of (M, g), and E2 denotes the Dirichlet energy. It is conjectured that near BPS skyrmions tend to restricted harmonic maps in the BPS limit. It is shown that φ is restricted harmonic if and only if φ∗ h has exact divergence, and a linear stability theory of restricted harmonic maps is developed, from which it follows that all weakly conformal maps are stable restricted harmonic. Examples of restricted harmonic maps in every degree class R3 → SU(2) and R2 →S2 are constructed. It is shown that the axially symmetric BPS skyrmions on which all previous analytic studies of near BPS Skyrme models have been based, are not restricted harmonic, casting doubt on the phenomenological predictions of such studies. The problem of minimizing E2 for φ :Rk → N over all linear volume preserving diffeomorphisms is solved explicitly, and a deformed axially symmetric family of Skyrme fields constructed which are candidates for approximate near BPS skyrmions at low baryon number. The notion of restricted harmonicity is generalized to restricted F-criticality where F is any functional on maps (M, g) →(N, h) which is, in a precise sense, geometrically natural. The case where F is a linear combination of E2 and E4, the usual Skyrme term, is studied in detail, and it is shown that inverse stereographic projection R3 →S3 ≡ SU(2) is stable restricted F-critical for every such F.

  3. Bouncing universe and non-BPS branes

    OpenAIRE

    Loewenfeld, Philipp Höffer v.; Kang, Jin U.; Moeller, Nicolas; Sachs, Ivo

    2009-01-01

    We describe string frame bouncing universe scenarios involving the creation and annihilation of a non-BPS D9-brane in type IIA superstring theory. We find several classes of solutions, in which the bounce is driven by the tachyon dynamics of the non-BPS brane. The metric and the dilaton are consistently described in terms of the lowest order effective action. The bounce solutions interpolate between contracting and expanding pre-big bang (or post-big bang) solutions. The singular behavior of ...

  4. BPS Electromagnetic Waves on Giant Gravitons

    CERN Document Server

    Kim, S; Kim, Seok; Lee, Kimyeong

    2005-01-01

    We find new 1/8-BPS giant graviton solutions in $AdS_5 \\times S^5$, carrying three angular momenta along $S^5$, and investigate their properties. Especially, we show that nonzero worldvolume gauge fields are admitted preserving supersymmetry. These gauge field modes can be viewed as electromagnetic waves along the compact D3 brane, whose Poynting vector contributes to the BPS angular momenta. We also analyze the (nearly-)spherical giant gravitons with worldvolume gauge fields in detail. Expressing the $S^3$ in Hopf fibration ($S^1$ fibred over $S^2$), the wave propagates along the $S^1$ fiber.

  5. Stacking non-BPS D-branes

    International Nuclear Information System (INIS)

    We present a candidate supergravity solution for a stacked configuration of stable non-BPS D-branes in Type II string theory compactified on T4/Z2. This gives a supergravity description of nonabelian tachyon condensation on the brane woldvolume. (author)

  6. Quantification of cross-sectional artery wall motion with IVUS image registration

    Science.gov (United States)

    Oakeson, Kevin D.; Zhu, Hui; Friedman, Morton H.

    2004-04-01

    Atherosclerotic lesions have been shown to have different mechanical properties than the non-diseased artery. Calculating vessel wall strain from cross-sectional vessel wall motions allows for the measurement of local stiffness. In this paper, a robust method is developed to track cross-sectional displacements of an artery wall using two different intravascular ultrasound (IVUS) images acquired at two different pressure levels respectively. First, the vessel wall region in one image is segmented semi-automatically by refining two spline-based contours to the locations of inner and outer vessel wall borders. Then the ringlike wall region in one image is registered to its counterpart in the other image in polar coordinates. The registration is performed by minimizing an energy function of the 2D motion field based on a spline-deformable-model. Both intensity and gradient information of the images are used to construct the energy function so that an accurate registration can be achieved. Registration accuracy was tested on simulated motions using IVUS images of a human coronary artery and a porcine carotid. The wall displacement fields calculated from real motion images are also demonstrated.

  7. A Low Cross-Polarization Smooth-Walled Horn with Improved Bandwidth

    Science.gov (United States)

    Zeng, Lingzhen; Bennett, Charles L.; Chuss, David T.; Wollack, Edward J.

    2009-01-01

    Corrugated feed horns offer excellent beam symmetry, main beam efficiency, and cross-polar response over wide bandwidths, but can be challenging to fabricate. An easier-to-manufacture smooth-walled feed is explored that approximates these properties over a finite bandwidth. The design, optimization and measurement of a monotonically-profiled, smooth-walled scalar feedhorn with a diffraction-limited approximately 7 degrees full width at half maximum (FWHM) is presented. The feed was demonstrated to have low cross polarization (<-30 dB) across the frequency range 33-45 GHz (30% fractional bandwidth). A return loss better than -28 dB was measured across the band.

  8. An investigation of wall thinning and cross sectional geometry change of bent tube of small diameters

    Energy Technology Data Exchange (ETDEWEB)

    Van, Nguyen Dang; Ihn, Namgung [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    The ununiformed deformation of cross section of bent tube also occurs, which is not perfectly circular and uniform but a significant ovality can result in from the fabrication process. In this study, an investigation of the deformation profile of bent tube such as wall thickening/thinning and cross-sectional distortion in cold bending process will be performed. The finite element model, using ANSYS 14.5, is developed and simulated the bending process. The results will be investigated for any change of diameter and circularity perpendicular to the bending axis. The analyses showed that the change of wall thickness of tube will happen in bending process. Consequently, the bend region of tube appears thicker wall at intrados and thinner wall at extrados. Moreover, bending process affects the ovality of tube cross section at bend region. From these results, wall thinning and cross-sectional ovality change need to be considered in the application and design of tube. In case of ICI guide tube, the inner circularity very important since ICI probe has to pass through the bend elbow, and any deviation from the tolerance causes stuck of ICI probe in the bend region. This is one of the particular applications where geometric deviations need to be carefully monitored. In fluid application of tube, the thinning is more of concern than the ovality of cross section. Hence there is also limit on how much wall thinning be allowed. The simulation presented in this paper is focused on the estimation of geometric variation resulted in bending process of tube with typical bending process.

  9. A note on multiply wound BPS Wilson loops in ABJM

    OpenAIRE

    Bianchi, Marco S.

    2016-01-01

    We consider BPS Wilson loops in planar ABJM theory, wound multiple times around the great circle. We compute the expectation value of the 1/6-BPS and 1/2-BPS Wilson loops to three- and two-loop order in perturbation theory, respectively, dealing with the combinatorics of multiple winding via recursive relations. For the 1/6-BPS Wilson loop we perform the computation at generic framing and at framing 1 we find agreement with the localization result. For the 1/2-BPS Wilson loop we compute the e...

  10. Wall-crossing, Rogers dilogarithm, and the QK/HK correspondence

    CERN Document Server

    Alexandrov, Sergei; Pioline, Boris

    2011-01-01

    When formulated in twistor space, the D-instanton corrected hypermultiplet moduli space in N=2 string vacua and the Coulomb branch of rigid N=2 gauge theories on $R^3 \\times S^1$ are strikingly similar and, to a large extent, dictated by consistency with wall-crossing. We elucidate this similarity by showing that these two spaces are related under a general duality between, on one hand, quaternion-Kahler manifolds with a quaternionic isometry and, on the other hand, hyperkahler manifolds with a rotational isometry, further equipped with a hyperholomorphic circle bundle with a connection. We show that the transition functions of the hyperholomorphic circle bundle relevant for the hypermultiplet moduli space are given by the Rogers dilogarithm function, and that consistency across walls of marginal stability is ensured by the motivic wall-crossing formula of Kontsevich and Soibelman. We illustrate the construction on some simple examples of wall-crossing related to cluster algebras for rank 2 Dynkin quivers. In...

  11. Pressure field in flow through uniform straight pipes with varying wall cross curvature.

    Science.gov (United States)

    Naili, Salah; Thiriet, Marc

    2005-10-01

    Pressure fields in rigid smooth straight tubes with an axially uniform cross section, in which an incompressible Newtonian fluid flows steadily, have been determined. Five cross section shapes are used. The reference cross section S0 is slightly elliptic (ellipticity of 1.005). Four cross section shapes, which mimic collapsed vessels in an uniformly frozen state, are defined according to the curvature of their opposite faces (the mid-face is located on the minor axis) Sq (parallel faces), St (face folding), Sc (point contact between faces) and Sl (line contact). These four selected cross shapes are characterized by large changes in both the cross sectional shape and area with respect to S0. The cross shapes are obtained from the computation of the deformation under uniform transmural pressures, without extension, of a thin-walled conduit of infinite length and of homogeneous purely elastic walls of constant thickness. The Navier-Stokes equations are solved using the finite element method for the five tubes summation operator0, summation operatorq, summation operatort, summation operatorc and summation operatorl, which are associated with S0,Sq,St,Sc and Sl, respectively. The numerical tests are performed with the same value of the volume flow rate whatever the tube configuration for three Reynolds numbers ( [See text] ). The present work is aimed at studying the pressure field for the design of the flow chamber in which endothelial cells are cultured. This field is used not only to define a new relative pressure index to determine the entry length but also to estimate the wall shear stress when the flow is fully developed. PMID:16124988

  12. Baby Skyrme Model, Near-BPS Approximations and Supersymmetric Extensions

    OpenAIRE

    Bolognesi, S.; Zakrzewski, W.

    2014-01-01

    We study the baby Skyrme model as a theory that interpolates between two distinct BPS systems. For this a near-BPS approximation can be used which, however, involves a small deviation from each of the two BPS limits. We provide analytical explanation and numerical support for the validity of this approximation. We then study the set of all possible supersymmetric extensions of the baby Skyrme model with ${\\cal N}=1$ and the particular ones with extended ${\\cal N}=2$ supersymmetries and relate...

  13. Baby Skyrme model, near-BPS approximations, and supersymmetric extensions

    Science.gov (United States)

    Bolognesi, S.; Zakrzewski, W.

    2015-02-01

    We study the baby Skyrme model as a theory that interpolates between two distinct BPS systems. For this, a near-BPS approximation can be used when there is a small deviation from each of the two BPS limits. We provide analytical explanation and numerical support for the validity of this approximation. We then study the set of all possible supersymmetric extensions of the baby Skyrme model with N =1 and the particular ones with extended N =2 supersymmetries and relate this to the above mentioned almost-BPS approximation.

  14. Baby Skyrme Model, Near-BPS Approximations and Supersymmetric Extensions

    CERN Document Server

    Bolognesi, S

    2014-01-01

    We study the baby Skyrme model as a theory that interpolates between two distinct BPS systems. For this a near-BPS approximation can be used which, however, involves a small deviation from each of the two BPS limits. We provide analytical explanation and numerical support for the validity of this approximation. We then study the set of all possible supersymmetric extensions of the baby Skyrme model with ${\\cal N}=1$ and the particular ones with extended ${\\cal N}=2$ supersymmetries and relate this to the above mentioned almost-BPS approximation.

  15. Level crossings, excess times and transient plasma-wall interactions in fusion plasmas

    CERN Document Server

    Theodorsen, Audun

    2016-01-01

    Based on a stochastic model for intermittent fluctuations in the boundary region of magnetically confined plasmas, an expression for the level crossing rate is derived from the joint distribution of the process and its derivative. From this the average time spent by the process above a certain threshold level is obtained. This provides novel predictions of plasma-wall interactions due to transient transport events associated with radial motion of blob-like structures in the scrape-off layer.

  16. Lie n-algebras of BPS charges

    CERN Document Server

    Sati, Hisham

    2015-01-01

    We uncover higher algebraic structures on Noether currents and BPS charges. It is known that equivalence classes of conserved currents form a Lie algebra. We show that at least for target space symmetries of higher parameterized WZW-type sigma-models this naturally lifts to a Lie (p+1)-algebra structure on the Noether currents themselves. Applied to the Green-Schwarz-type action functionals for super p-brane sigma-models this yields super Lie (p+1)-algebra refinements of the traditional BPS brane charge extensions of supersymmetry algebras. We discuss this in the generality of higher differential geometry, where it applies also to branes with (higher) gauge fields on their worldvolume. Applied to the M5-brane sigma-model we recover and properly globalize the M-theory super Lie algebra extension of 11-dimensional superisometries by 2-brane and 5-brane charges. Passing beyond the infinitesimal Lie theory we find cohomological corrections to these charges in higher analogy to the familiar corrections for D-brane...

  17. The Skyrme model in the BPS limit

    CERN Document Server

    Adam, C; Sanchez-Guillen, J; Vazquez, R; Wereszczynski, A

    2015-01-01

    In this review, we summarise the main features of the BPS Skyrme model which provides a physically well-motivated idealisation of atomic nuclei and nuclear matter: 1) it leads to zero binding energies for classical solitons (while realistic binding energies emerge owing to the semiclassical corrections, the Coulomb interaction and isospin breaking); 2) it describes a perfect non-barotropic fluid already at the microscopic (field theoretical) level which allows to study thermodynamics beyond the mean-field limit. These properties allow for an approximate but analytical calculation of binding energies of the most abundant nuclei, for a determination of the equation of state of skyrmionic matter (both in the full field theory and in a mean-field approximation) as well as the description of neutron stars as Skyrme solitons with a very good agreement with available observational data. All these results suggest that the proper low energy effective model of QCD should be close to the BPS Skyrme model in a certain se...

  18. THIN-WALLED CROSS SECTION SHAPE INFLUENCE ON STEEL MEMBER RESISTANCE

    Directory of Open Access Journals (Sweden)

    Elżbieta Urbańska-Galewska

    2016-03-01

    Full Text Available This work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into account local, distortional and overall buckling. The results are presented in a tabular and a graphical way and clearly confirm that cross-section forming distinctly impact the cold-formed member resistance. The authors choose these cross-sections that work better in compression state and the other (those slender and high that function more efficiently are subjected to bending.

  19. A note on multiply wound BPS Wilson loops in ABJM

    CERN Document Server

    Bianchi, Marco S

    2016-01-01

    We consider BPS Wilson loops in planar ABJM theory, wound multiple times around the great circle. We compute the expectation value of the 1/6-BPS and 1/2-BPS Wilson loops to three- and two-loop order in perturbation theory, respectively, dealing with the combinatorics of multiple winding via recursive relations. For the 1/6-BPS Wilson loop we perform the computation at generic framing and at framing 1 we find agreement with the localization result. For the 1/2-BPS Wilson loop we compute the expectation value at trivial framing and by comparison with the matrix model expression we extract the framing dependence of the fermion diagrams.

  20. BPS counting for knots and combinatorics on words

    CERN Document Server

    Kucharski, Piotr

    2016-01-01

    We discuss relations between quantum BPS invariants defined in terms of a product decomposition of certain series, and difference equations (quantum A-polynomials) that annihilate such series. We construct combinatorial models whose structure is encoded in the form of such difference equations, and whose generating functions (Hilbert-Poincar\\'e series) are solutions to those equations and reproduce generating series that encode BPS invariants. Furthermore, BPS invariants in question are expressed in terms of Lyndon words in an appropriate language, thereby relating counting of BPS states to the branch of mathematics referred to as combinatorics on words. We illustrate these results in the framework of colored extremal knot polynomials: among others we determine dual quantum extremal A-polynomials for various knots, present associated combinatorial models, find corresponding BPS invariants (extremal Labastida-Mari\\~no-Ooguri-Vafa invariants) and discuss their integrality.

  1. Cell wall fermentation kinetics are impacted more by lignin content and ferulate cross-linking than by lignin composition

    Science.gov (United States)

    BACKGROUND: We used a biomimetic model system to ascertain how reductions in ferulate-lignin cross-linking and shifts in lignin composition influence ruminal cell wall fermentation. Primary walls from maize cell suspensions with normal or reduced feruloylation were artificially lignified with variou...

  2. Perturbative type II amplitudes for BPS interactions

    CERN Document Server

    Basu, Anirban

    2015-01-01

    We consider the perturbative contributions to the R^4, D^4 R^4 and D^6 R^4 interactions in toroidally compactified type II string theory. These BPS interactions do not receive perturbative contributions beyond genus three. We derive Poisson equations satisfied by these moduli dependent string amplitudes. These T--duality invariant equations have eigenvalues that are completely determined by the structure of the integrands of the multi--loop amplitudes. The source terms are given by boundary terms of the moduli space of Riemann surfaces corresponding to both separating and non--separating nodes. These are determined directly from the string amplitudes, as well as from the logarithmic divergences of maximal supergravity. We explicitly solve these Poisson equations in nine and eight dimensions.

  3. Superconformal Index, BPS Monodromy and Chiral Algebras

    CERN Document Server

    Cecotti, Sergio; Vafa, Cumrun; Yan, Wenbin

    2015-01-01

    We show that specializations of the 4d $\\mathcal{N}=2$ superconformal index labeled by an integer $N$ is given by $\\textrm{Tr}\\,{\\cal M}^N$ where ${\\cal M}$ is the Kontsevich-Soibelman monodromy operator for BPS states on the Coulomb branch. We provide evidence that the states enumerated by these limits of the index lead to a family of 2d chiral algebras $\\mathcal{A}_{N}$. This generalizes the recent results for the $N=-1$ case which corresponds to the Schur limit of the superconformal index. We show that this specialization of the index leads to the same integrand as that of the elliptic genus of compactification of the superconformal theory on $S^2\\times T^2$ where we turn on $\\frac{1}{2} N$ units of $U(1)_r$ flux on $S^2$.

  4. BpsR Modulates Bordetella Biofilm Formation by Negatively Regulating the Expression of the Bps Polysaccharide

    OpenAIRE

    Conover, Matt S.; Redfern, Crystal J.; Ganguly, Tridib; Sukumar, Neelima; Sloan, Gina; Mishra, Meenu; Deora, Rajendar

    2012-01-01

    Bordetella bacteria are Gram-negative respiratory pathogens of animals, birds, and humans. A hallmark feature of some Bordetella species is their ability to efficiently survive in the respiratory tract even after vaccination. Bordetella bronchiseptica and Bordetella pertussis form biofilms on abiotic surfaces and in the mouse respiratory tract. The Bps exopolysaccharide is one of the critical determinants for biofilm formation and the survival of Bordetella in the murine respiratory tract. In...

  5. Time-resolved magnetization dynamics of cross-tie domain walls in permalloy microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Miguel, J; Kurde, J; Piantek, M; Kuch, W [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany); Sanchez-Barriga, J; Heitkamp, B; Kronast, F; Duerr, H A [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Bayer, D; Aeschlimann, M, E-mail: jorge.miguel@fu-berlin.d [Fachbereich Physik, Universitaet Kaiserslautern, Erwin-Schroedinger Strasse 46, D-67663 Kaiserslautern (Germany)

    2009-12-02

    We report on a picosecond time-resolved x-ray magnetic circular dichroic-photoelectron emission microscopy study of the evolution of the magnetization components of a microstructured permalloy platelet comprising three cross-tie domain walls. A laser-excited photoswitch has been used to apply a triangular 80 Oe, 160 ps magnetic pulse. Micromagnetic calculations agree well with the experimental results, both in time and frequency, illustrating the large angle precession in the magnetic domains with magnetization perpendicular to the applied pulse, and showing how the magnetic vortices revert their core magnetization while the antivortices remain unaffected.

  6. BPS black holes in gauged N = 4, D = 4 supergravity

    International Nuclear Information System (INIS)

    We find solutions of the bosonic sector of gauged N = 4, D = 4 SU(2) x SU(2) supergravity, which represent dilaton black holes with toroidal or spherical event horizons. The axion is consistently truncated, and the gauge group is broken to U(1) x U(1). The spherical black holes carry two electric and two magnetic abelian charges, whereas the toroidal holes have vanishing magnetic charges. The space-time metrics are warped products, and the manifolds turn out to be globally hyperbolic, in contrast to standard gauged supergravity ground states. It is shown that in the toroidal case, there are solutions preserving one quarter or one half of the supersymmetries, while for spherical topologies all supersymmetries are broken. In general, the toroidal BPS states represent naked singularities, but there is also a supersymmetric black hole with vanishing Hawking temperature. The ((1)/(2)) supersymmetric case arises for vanishing charges and mass, and represents the known domain wall solution of the Freedman-Schwarz model. It provides the background in which the black holes live. Finally, we use Chamseddine's and Volkov's Kaluza-Klein interpretation of gauged N = 4, D = 4 SU(2) x SU(2) supergravity to lift our solutions to ten and eleven dimensions and to consider them as solutions to the leading order equations of motion of the string/M-theory effective action

  7. Thin-Walled Cross-Linked Acetabular Liners Need Not Exhibit Reduced Locking Strength.

    Science.gov (United States)

    Murtha, Andrew S; Roy, Marcel E; Whiteside, Leo A; Tilden, David S; Schmitt, Krystal L

    2015-08-01

    Use of larger diameter femoral heads has emerged as a promising strategy to reduce the risk of dislocation after total hip arthroplasty, but thinning the walls of cross-linked ultra-high-molecular-weight polyethylene (UHMWPE) acetabular liners to accommodate these larger heads may compromise the locking mechanism of the liner. The purpose of this study was to test the mechanical integrity of the locking mechanism in cross-linked and re-melted UHMWPE acetabular components with reduced wall thickness. The locking mechanism of cross-linked (100 kGy/re-melted) acetabular liners in sizes 50/28, 50/36, and 52/36 mm of 1 design was evaluated by lever-out tests and torsion tests. Torsion tests were performed at 2 angles to isolate the liner's locking tabs independent of the contribution of its central post. Lever-out testing demonstrated nominally reduced failure strength in 50/36-mm liners (13.3 N · m) compared with 50/28-mm liners (12.3 N · m; P=.0502), whereas the lever-out strength of 52/36-mm liners was 12.2±0.94 N · m. Failure torques were similar between 50/28- and 50/36-mm liners at 45° and 90°, but the failure torque of size 52/36-mm liners was significantly higher at each angle. The use of larger diameter femoral heads does not compromise the locking mechanism of thinned MicroSeal (Signal Medical Corp, Marysville, Michigan) acetabular liners. Use of a cross-linked UHMWPE acetabular liner, with a locking mechanism that is not compromised when the liner is thinned to a thickness of at least 2.86 mm, appears to be a biomechanically sound construct when articulated with large diameter femoral heads. PMID:26270761

  8. Near BPS Wilson Loop in beta-deformed Theories

    OpenAIRE

    Chu, Chong-Sun; Giataganas, Dimitrios

    2007-01-01

    We propose a definition of the Wilson loop operator in the N=1 beta-deformed supersymmetric Yang-Mills theory. Although the operator is not BPS, it has a finite expectation value at least up to order (g^2 N)^2. This does not happen generally for a generic non-BPS Wilson loop whose expectation value is UV divergent. For this reason we call this a near-BPS Wilson loop and conjecture that its exact expectation value is finite. We derive the general form of the boundary condition satisfied by the...

  9. 1/2 BPS geometries of M2 giant gravitons

    International Nuclear Information System (INIS)

    We construct the general 1/2 BPS M2 giant graviton solutions asymptotic to the 11-dimensional maximally supersymmetric plane-wave background, based on the recent work of Lin, Lunin, and Maldacena. The solutions have null singularity and we argue that it is unavoidable to have null singularity in the proposed framework, although the solutions are still physically relevant. They involve an arbitrary function F(x) which is shown to have a correspondence to the 1/2 BPS states of the Berenstein-Maldacena-Nastase (BMN) matrix model. A detailed map between the 1/2 BPS states of both sides is worked out

  10. Geometric realizations of BPS states in N=2 theories

    International Nuclear Information System (INIS)

    We study the BPS spectrum of the theory on a D3-brane probe in F-theory. The BPS states are realized by multi-string configurations in space-time. Only certain configurations obeying a selection rule give rise to BPS states in the four-dimensional probe theory. Using these string configurations, we determine the spectrum of N=2 SU(2) Yang-Mills. We also explore the relation between multi-string configurations, M-theory membranes and self-dual strings. (orig.)

  11. No fermionic wigs for BPS attractors in 5 dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, Lorenzo G.C., E-mail: lgentile@pd.infn.it [DISIT, Università del Piemonte Orientale, via T. Michel, 11, Alessandria I-15120 (Italy); Dipartimento di Fisica “Galileo Galilei”, Università di Padova, via Marzolo 8, I-35131 Padova (Italy); INFN, Sezione di Padova, via Marzolo 8, I-35131 Padova (Italy); Grassi, Pietro A., E-mail: pgrassi@mfn.unipmn.it [DISIT, Università del Piemonte Orientale, via T. Michel, 11, Alessandria I-15120 (Italy); INFN – Gruppo Collegato di Alessandria – Sezione di Torino (Italy); Marrani, Alessio, E-mail: alessio.marrani@fys.kuleuven.be [Instituut voor Theoretische Fysica, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Mezzalira, Andrea, E-mail: andrea.mezzalira@ulb.ac.be [Physique Théorique et Mathématique, Université Libre de Bruxelles, C.P. 231, B-1050 Bruxelles (Belgium); Sabra, Wafic A., E-mail: ws00@aub.edu.lb [Centre for Advanced Mathematical Sciences and Physics Department, American University of Beirut (Lebanon)

    2014-07-30

    We analyze the fermionic wigging of 1/2-BPS (electric) extremal black hole attractors in N=2, D=5 ungauged Maxwell–Einstein supergravity theories, by exploiting anti-Killing spinors supersymmetry transformations. Regardless of the specific data of the real special geometry of the manifold defining the scalars of the vector multiplets, and differently from the D=4 case, we find that there are no corrections for the near-horizon attractor value of the scalar fields; an analogous result also holds for 1/2-BPS (magnetic) extremal black string. Thus, the attractor mechanism receives no fermionic corrections in D=5 (at least in the BPS sector)

  12. 1/2 BPS Geometries of M2 Giant Gravitons

    CERN Document Server

    Bak, D; Yee, H U; Bak, Dongsu; Siwach, Sanjay; Yee, Ho-Ung

    2005-01-01

    We construct the general 1/2 BPS M2 giant graviton solutions asymptotic to the eleven-dimensional maximally supersymmetric plane wave background, based on the recent work of Lin, Lunin and Maldacena. The solutions have null singularity and we argue that it is unavoidable to have null singularity in the proposed framework, although the solutions are still physically relevant. They involve an arbitrary function F(x) which is shown to have a correspondence to the 1/2 BPS states of the BMN matrix model. A detailed map between the 1/2 BPS states of both sides is worked out.

  13. Monstrous BPS-Algebras and the Superstring Origin of Moonshine

    CERN Document Server

    Paquette, Natalie M; Volpato, Roberto

    2016-01-01

    We provide a physics derivation of Monstrous moonshine. We show that the McKay-Thompson series $T_g$, $g\\in \\mathbb{M}$, can be interpreted as supersymmetric indices counting spacetime BPS-states in certain heterotic string models. The invariance groups of these series arise naturally as spacetime T-duality groups and their genus zero property descends from the behaviour of these heterotic models in suitable decompactification limits. We also show that the space of BPS-states forms a module for the Monstrous Lie algebras $\\mathfrak{m}_g$, constructed by Borcherds and Carnahan. We argue that $\\mathfrak{m}_g$ arise in the heterotic models as algebras of spontaneously broken gauge symmetries, whose generators are in exact correspondence with BPS-states. This gives $\\mathfrak{m}_g$ an interpretation as a kind of BPS-algebra.

  14. Cosmic microwave anisotropies from BPS semilocal strings

    CERN Document Server

    Urrestilla, Jon; Hindmarsh, Mark; Kunz, Martin; Liddle, Andrew R

    2007-01-01

    We present the first ever calculation of cosmic microwave background CMB anisotropy power spectra from semilocal cosmic strings, obtained via simulations of a classical field theory. Semilocal strings are a type of non-topological defect arising in some models of inflation motivated by fundamental physics, and are thought to relax the constraints on the symmetry breaking scale as compared to models with (topological) cosmic strings. We derive constraints on the model parameters, including the string tension parameter mu, from fits to cosmological data, and find that in this regard BPS semilocal strings resemble textures more than topological strings. The observed microwave anisotropy at l=10 is reproduced if Gmu = 4.9x10^{-6} (G is Newton's constant). However as with other defects the spectral shape does not match observations, and in models with inflationary perturbations plus semilocal strings the 95% confidence level upper bound is Gmu<1.9x10^{-6} when CMB data, Hubble Key Project and Big Bang Nucleosyn...

  15. IDENTIFYING GENES CONTROLLING FERULATE CROSS-LINKING FORMATION IN GRASS CELL WALLS

    Energy Technology Data Exchange (ETDEWEB)

    de O Buanafina, Marcia Maria

    2013-10-16

    DESCRIPTION/ABSTRACT This proposal focuses on cell wall feruloylation and our long term goal is to identify and isolate novel genes controlling feruloylation and to characterize the phenotype of mutants in this pathway, with a spotlight on cell wall properties. Currently, the genes underlying AX feruloylation have not been identified and the isolation of such genes could be of great importance in manipulating ferulates accretion to the wall. Mutation of the feruloyl transferase gene(s) should lead to less ferulates secreted to the cell wall and reduced ferulate cross-linking. Our current research is based on the hypothesis that controlling the level of total feruloylation will have a direct impact on the level of cross-linking and in turn impact biomass utility for forage and biofuel production. Our results/accomplishments for this project so far include: 1. Mutagenised Brachypodium population. We have developed EMS mutagenized populations of model grass species Brachypodium distachyon. EMS populations have been developed from over 28,000 mutagenized seeds generating 5,184 M2 families. A total of 20,793 plants have been screened and 1,233 were originally selected. 2. Selected Brachypodium mutants: Potential mutants on their levels of cell wall ferulates and cell wall AX ? have been selected from 708 M2 families. A total of 303 back-crosses to no-mutagenized parental stock have been done, followed by selfing selected genotypes in order to confirm heritability of traits and to remove extraneous mutations generated by EMS mutagenesis. We are currently growing 12 F5 and F6 populations in order to assess CW composition. If low level of ferulates are confirmed in the candidate lines selected the mutation could be altered in different in one or several kinds of genes such as genes encoding an AX feruloyl transferase; genes encoding the arabinosyl transferase; genes encoding the synthesis of the xylan backbone; genes encoding enzymes of the monolignol pathway affecting FA

  16. Large N BPS states and emergent quantum gravity

    Science.gov (United States)

    Berenstein, David

    2006-01-01

    This paper provides a heuristic derivation of how classical gravitational physics in the AdS/CFT correspondence appears from the strong dynamics of the Script N = 4 SYM theory in a systematic way. We do this in a minisuperspace approximation by studying 1/8 BPS configurations. We can show that our description matches the semiclassical physics of 1/8 BPS states in supergravity. We also provide a heuristic description of how massive strings appear in the geometry, and how at strong 't Hooft coupling they become local on the S5 suggesting that they can be realized as a sigma model on a weakly curved background. We show that the dynamics of 1/8 BPS dynamics of Script N = 4 SYM on a round S3 can be reduced to that of a matrix model for commuting matrices. Including measure factors, we show that this effective dynamics is related to bosons living on a six dimensional phase space with repulsive interactions. Because of these interactions, we can argue that on the ground state the bosons assemble themselves on a spherical shell in the shape of a round five sphere. This sphere will be identified with the S5 in the AdS dual geometry. To do this, we first define a precise way to coarse grain the dynamics. We use half BPS configurations as a toy model for this coarse graining, and we can reproduce the droplet picture of these half BPS states systematically. The droplet appears as the saddle point approximation of a statistical ensemble related to the square of the wave function of the eigenvalues of a complex matrix. This procedure is also applied to the set of 1/8 BPS configurations to extract the geometry, giving an analog of the droplet picture of half BPS states for the case of 1/8 BPS configurations. We also have a conjectured realization of some 1/8 BPS giant graviton wave functions in the dynamics, which captures all 1/8 BPS giant gravitons constructed by Mikhailov. This leads to a lot of different topology changes which can be treated heuristically.

  17. 'Strengthening the fungal cell wall through chitin-glucan cross-links: effects on morphogenesis and cell integrity'.

    Science.gov (United States)

    Arroyo, Javier; Farkaš, Vladimír; Sanz, Ana Belén; Cabib, Enrico

    2016-09-01

    The cross-linking of polysaccharides to assemble new cell wall in fungi requires transglycosylation mechanisms by which preexisting glycosidic linkages are broken and new linkages are created between the polysaccharides. The molecular mechanisms for these processes, which are essential for fungal cell biology, are only now beginning to be elucidated. Recent development of in vivo and in vitro biochemical approaches has allowed characterization of important aspects about the formation of chitin-glucan covalent cell wall cross-links by cell wall transglycosylases of the CRH family and their biological function. Covalent linkages between chitin and glucan mediated by Crh proteins control morphogenesis and also play important roles in the remodeling of the fungal cell wall as part of the compensatory responses necessary to counterbalance cell wall stress. These enzymes are encoded by multigene families of redundant proteins very well conserved in fungal genomes but absent in mammalian cells. Understanding the molecular basis of fungal adaptation to cell wall stress through these and other cell wall remodeling enzymatic activities offers an opportunity to explore novel antifungal treatments and to identify potential fungal virulence factors. PMID:27185288

  18. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  19. BPS Wilson loops in Minkowski spacetime and Euclidean space

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Hao; Wu, Jun-Bao; Zhang, Jia-ju [Chinese Academy of Sciences, Theoretical Physics Division, Institute of High Energy Physics, Beijing (China); Chinese Academy of Sciences, Theoretical Physics Center for Science Facilities, Beijing (China)

    2015-12-15

    We give evidence that spacelike BPS Wilson loops do not exist in Minkowski spacetime. We show that spacelikeWilson loops in Minkowski spacetime cannot preserve any supersymmetries, in d = 4 N = 4 super Yang-Mills theory, d = 3 N = 2 super Chern-Simons-matter theory, and d = 3 N = 6 Aharony-Bergman-Jafferis- Maldacena theory. We not only show this using infinite straight lines and circles as examples, but also we give proofs for general curves. We attribute this to the conflicts of the reality conditions of the spinors. However, spacelike Wilson loops do exist in Euclidean space. There are both BPS Wilson loops along infinite straight lines and circular BPS Wilson loops. This is because the reality conditions of the spinors are lost after Wick rotation. The result is reasonable in view of the AdS/CFT correspondence. (orig.)

  20. BPS Wilson loops in Minkowski spacetime and Euclidean space

    Science.gov (United States)

    Ouyang, Hao; Wu, Jun-Bao; Zhang, Jia-ju

    2015-12-01

    We give evidence that spacelike BPS Wilson loops do not exist in Minkowski spacetime. We show that spacelike Wilson loops in Minkowski spacetime cannot preserve any supersymmetries, in d = 4 N = 4 super Yang-Mills theory, d = 3 N = 2 super Chern-Simons-matter theory, and d = 3 N = 6 Aharony-Bergman-Jafferis-Maldacena theory. We not only show this using infinite straight lines and circles as examples, but also we give proofs for general curves. We attribute this to the conflicts of the reality conditions of the spinors. However, spacelike Wilson loops do exist in Euclidean space. There are both BPS Wilson loops along infinite straight lines and circular BPS Wilson loops. This is because the reality conditions of the spinors are lost after Wick rotation. The result is reasonable in view of the AdS/CFT correspondence.

  1. Intravesical liposome drug delivery and IC/BPS

    Science.gov (United States)

    Janicki, Joseph J.; Gruber, Michele A.

    2015-01-01

    Intravesical therapy has previously shown to be effective in delaying or preventing recurrence of superficial bladder cancer. This local route of drug administration is now demonstrating promise in the treatment of interstitial cystitis/bladder pain syndrome (IC/BPS) with the benefit of minimal systemic side effects. Liposomes (LPs) are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core. They can incorporate drug molecules, both hydrophobic and hydrophilic, and vastly improve cellular uptake of these drug molecules via endocytosis. Intravesical LPs have therapeutic effects on IC/BPS patients, mainly due to their ability to form a protective lipid film on the urothelial surface and repair the damaged urothelium. This review considers the current status of intravesical LPs and LP mediated drug delivery for the treatment of IC/BPS. PMID:26816855

  2. BPS Wilson loops in Minkowski spacetime and Euclidean space

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Hao, E-mail: ouyangh@ihep.ac.cn; Wu, Jun-Bao, E-mail: wujb@ihep.ac.cn; Zhang, Jia-ju, E-mail: jjzhang@ihep.ac.cn [Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Rd, 100049, Beijing (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, 19B Yuquan Rd, 100049, Beijing (China)

    2015-12-21

    We give evidence that spacelike BPS Wilson loops do not exist in Minkowski spacetime. We show that spacelike Wilson loops in Minkowski spacetime cannot preserve any supersymmetries, in d=4N=4 super Yang–Mills theory, d=3N=2 super Chern–Simons-matter theory, and d=3N=6 Aharony–Bergman–Jafferis–Maldacena theory. We not only show this using infinite straight lines and circles as examples, but also we give proofs for general curves. We attribute this to the conflicts of the reality conditions of the spinors. However, spacelike Wilson loops do exist in Euclidean space. There are both BPS Wilson loops along infinite straight lines and circular BPS Wilson loops. This is because the reality conditions of the spinors are lost after Wick rotation. The result is reasonable in view of the AdS/CFT correspondence.

  3. Some aspects of self-duality and generalised BPS theories

    Science.gov (United States)

    Adam, C.; Ferreira, L. A.; da Hora, E.; Wereszczynski, A.; Zakrzewski, W. J.

    2013-08-01

    If a scalar field theory in (1+1) dimensions possesses soliton solutions obeying first order BPS equations, then, in general, it is possible to find an infinite number of related field theories with BPS solitons which obey closely related BPS equations. We point out that this fact may be understood as a simple consequence of an appropriately generalised notion of self-duality. We show that this self-duality framework enables us to generalize to higher dimensions the construction of new solitons from already known solutions. By performing simple field transformations our procedure allows us to relate solitons with different topological properties. We present several interesting examples of such solitons in two and three dimensions.

  4. Some aspects of self-duality and generalised BPS theories

    CERN Document Server

    Adam, C; da Hora, E; Wereszczynski, A; Zakrzewski, W J

    2013-01-01

    If a scalar field theory in (1+1) dimensions possesses soliton solutions obeying first order BPS equations, then, in general, it is possible to find an infinite number of related field theories with BPS solitons which obey closely related BPS equations. We point out that this fact may be understood as a simple consequence of an appropriately generalised notion of self-duality. We show that this self-duality framework enables us to generalize to higher dimensions the construction of new solitons from already known solutions. By performing simple field transformations our procedure allows us to relate solitons with different topological properties. We present several interesting examples of such solitons in two and three dimensions.

  5. Abelianization of BPS quivers and the refined Higgs index

    International Nuclear Information System (INIS)

    We count Higgs “phase” BPS states of general non-Abelian quiver, possibly with loops, by mapping the problem to its Abelian, or toric, counterpart and imposing Weyl invariance later. Precise Higgs index computation is particularly important for quivers with superpotentials; the Coulomb “phase” index is recently shown to miss important BPS states, dubbed intrinsic Higgs states or quiver invariants. We demonstrate how the refined Higgs index is naturally decomposed to a sum over partitions of the charge. We conjecture, and show in simple cases, that this decomposition expresses the Higgs index as a sum over a set of partition-induced Abelian quivers of the same total charge but generically of smaller rank. Unlike the previous approach inspired by a similar decomposition of the Coulomb index, our formulae compute the quiver invariants directly, and thus offer a self-complete routine for counting BPS states

  6. Non-BPS Dirac-Born-Infeld Solitons

    OpenAIRE

    Ioannidou, Theodora; Papadopoulos, George; Sutcliffe, Paul(Department of Mathematical Sciences, Durham University, South Road, Durham, DH1 3LE, U.K.)

    1999-01-01

    We show that CPn sigma model solitons solve the field equations of a Dirac-Born-Infeld (DBI) action and, furthermore, we prove that the non-BPS soliton/anti-soliton solutions of the sigma model also solve the DBI equations. Using the moduli space approximation we compare the dynamics of the BPS sigma model solitons with that of the associated DBI solitons. We find that for the CP1 case the metric on the moduli space of sigma model solitons is identical to that of the moduli space of DBI solit...

  7. BPS index and 4d N=2 superconformal field theories

    CERN Document Server

    Sakai, Kazuhiro

    2016-01-01

    We study the BPS index for the four-dimensional rank-one N=2 superconformal field theories H_0, H_1, H_2, E_6, E_7, E_8. We consider compactifications of the E-string theory on T^2 in which these theories arise as low energy limits. Using this realization we clarify the general structure of the BPS index. The index is characterized by two exponents and a sequence of invariants. We determine the exponents and the first few invariants.

  8. BPS index and 4d N = 2 superconformal field theories

    Science.gov (United States)

    Sakai, Kazuhiro

    2016-07-01

    We study the BPS index for the four-dimensional rank-one N = 2 superconformal field theories H 0 , H 1 , H 2 , E 6 , E 7 , E 8. We consider compactifications of the E-string theory on T 2 in which these theories arise as low energy limits. Using this realization we clarify the general structure of the BPS index. The index is characterized by two exponents and a sequence of invariants. We determine the exponents and the first few invariants.

  9. Composite BPS skyrmions from an exact isospin symmetry breaking

    CERN Document Server

    Klimas, Pawel

    2016-01-01

    We study the BPS Skyrme model with potentials breaking the isospin symmetry and analyse how properties of exact solitonic solutions depend on a form of the isospin breaking potential. In the case of the strong symmetry breaking a new topologic structure is observed which enables us to decompose a BPS skyrmion into a lower dimensional defect localised on a brane (kink). We investigate some thermodynamical properties of such solitons as well as the role of the symmetry breaking potential in the resulting mean-field equation of state.

  10. Cross-Sectional Elasticity Imaging of Carotid Arterial Wall in Short-Axis Plane by Transcutaneous Ultrasound

    Science.gov (United States)

    Nakagawa, Nozomi; Hasegawa, Hideyuki; Kanai, Hiroshi

    2004-05-01

    We have developed the phased tracking method [H. Kanai, M. Sato, Y. Koiwa and N. Chubachi: IEEE Trans. UFFC 43 (1996) 791.] for measuring the minute change in thickness during one heartbeat and the elasticity of the arterial wall with transcutaneous ultrasound. When this method is applied to a plane perpendicular to the axis of the artery (short-axis plane) using a linear-type probe, only an ultrasonic beam which passes through the center of the artery coincides with the direction of the change in thickness. At other beam positions, the wall motion cannot be accurately tracked because the direction of wall expansion slips off the beam. To obtain the cross-sectional image of elasticity in the short-axis plane using transcutaneous ultrasound, in this paper, the directions of ultrasonic beams are designed so that each beam always passes through the center of the artery; thus, they always coincide with the direction of the wall expansion. In basic experiments, the accuracy in elasticity measurement was evaluated using a silicone rubber tube. In in vivo experiments, the minute change in wall thickness was measured along each ultrasonic beam, and the cross-sectional image of elasticity was obtained in the short-axis plane with transcutaneous ultrasound.

  11. Cross-Sectional Elasticity Imaging of Arterial Wall by Comparing Measured Change in Thickness with Model Waveform

    Science.gov (United States)

    Tang, Jiang; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-06-01

    For the assessment of the elasticity of the arterial wall, we have developed the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791] for measuring the minute change in thickness due to heartbeats and the elasticity of the arterial wall with transcutaneous ultrasound. For various reasons, for example, an extremely small deformation of the wall, the minute change in wall thickness during one heartbeat is largely influenced by noise in these cases and the reliability of the elasticity distribution obtained from the maximum change in thickness deteriorates because the maximum value estimation is largely influenced by noise. To obtain a more reliable cross-sectional image of the elasticity of the arterial wall, in this paper, a matching method is proposed to evaluate the waveform of the measured change in wall thickness by comparing the measured waveform with a template waveform. The maximum deformation, which is used in the calculation of elasticity, was determined from the amplitude of the matched model waveform to reduce the influence of noise. The matched model waveform was obtained by minimizing the difference between the measured and template waveforms. Furthermore, a random error, which was obtained from the reproducibility among the heartbeats of the measured waveform, was considered useful for the evaluation of the reliability of the measured waveform.

  12. BPS Degeneracies and Superconformal Index in Diverse Dimensions

    CERN Document Server

    Iqbal, Amer

    2012-01-01

    We present a unifying theme relating BPS partition functions and superconformal indices. In the case with complex SUSY central charges (as in N=2 in d=4 and N=(2,2) in d=2) the known results can be reinterpreted as the statement that the BPS partition functions can be used to compute a specialization of the superconformal indices. We argue that in the case with real central charge in the supersymmetry algebra, as in N=1 in d=5 (or the N=2 in d=3), the BPS degeneracy captures the full superconformal index. Furthermore, we argue that refined topological strings, which captures 5d BPS degeneracies of M-theory on CY 3-folds, can be used to compute 5d supersymmetric index including in the sectors with 3d defects for a large class of 5d superconformal theories. Moreover, we provide evidence that distinct Calabi-Yau singularities which are expected to lead to the same SCFT yield the same index.

  13. AdS/CFT and BPS Strings in Four Dimensions

    CERN Document Server

    Alishahiha, M; Alishahiha, Mohsen; Oz, Yaron

    1999-01-01

    We consider N=2 superconformal theories defined on a 3+1 dimensional hyperplane intersection of two sets of M5 branes. These theories have (tensionless) BPS string solitons. We use a dual supergravity formulation to deduce some of their properties via the AdS/CFT correspondence.

  14. Vortex partition functions, wall crossing and equivariant Gromov-Witten invariants

    CERN Document Server

    Bonelli, Giulio; Tanzini, Alessandro; Vasko, Petr

    2013-01-01

    In this paper we identify the problem of equivariant vortex counting in a (2,2) supersymmetric two dimensional quiver gauged linear sigma model with that of computing the equivariant Gromov-Witten invariants of the GIT quotient target space determined by the quiver. We provide new contour integral formulae for the I and J-functions encoding the equivariant quantum cohomology of the target space. Its chamber structure is shown to be encoded in the analytical properties of the integrand. This is explained both via general arguments and by checking several key cases. We show how several results in equivariant Gromov-Witten theory follow just by deforming the integration contour. In particular we apply our formalism to compute Gromov-Witten invariants of the C^3/Z_n orbifold and of the Uhlembeck (partial) compactification of the moduli space of instantons on C^2. Moreover, we analyse dualities of quantum cohomology rings of holomorphic vector bundles over Grassmannians, which are relevant to BPS Wilson loop algeb...

  15. Non-perturbative effects and wall-crossing from topological strings

    CERN Document Server

    Collinucci, Andres; Uranga, Angel M

    2009-01-01

    We argue that the Gopakumar-Vafa interpretation of the topological string partition function can be used to compute and resum certain non-perturbative brane instanton effects of type II CY compactifications. In particular the topological string A-model encodes the non-perturbative corrections to the hypermultiplet moduli space metric from general D1/D(-1)-brane instantons in 4d N=2 IIB models. By introducing fluxes and/or orientifolds and/or D-branes, we describe the reduction to 4d N=1 models, and describe the computation of non-perturbative superpotential contributions from resummed brane instantons. We argue that the connection between non-perturbative effects and the topological string underlies the continuity and holomorphy of non-perturbative effects across lines of BPS stability. The computation of non-perturbative effects from the topological string requires a 3d circle compactification and T-duality, relating effects from particles and instantons, suggesting a realization of the Kontsevich-Soibelmann...

  16. Trajectory measurements of a wall jet impinging onto a forward facing step entering a cross-flow

    International Nuclear Information System (INIS)

    This study examines a horizontal wall jet impinging onto a forward facing step in a cross-flow. Planar laser induced fluorescence (PLIF) experiments in a water channel indicate that the wall-jet flow after impinging onto the step, becomes a vertical jet with an elliptical cross section. Experiments indicate that the jet trajectory scales with the perimeter of the elliptical jet issuing vertically into the cross-flow. The trajectory consists of three regions: the near-field region which is well described by a power law with an exponent of 1/2, the mid-field region where the jet is fully bent over which is described by a power law with an exponent of 1/3, and a far-field region where the jet is dominated by the cross-flow. This paper provides a prediction of the plume behaviour based on the geometric and initial conditions of the jet (diameter, step height, distance from jet to step, and velocity ratio) alone. The Briggs entrainment model for a round jet was also used to predict the trajectories of the jet in the cross-flow. It was found that the entrainment coefficients, α and β, for the elliptical jet case had average values of 0.15 and 0.58 respectively.

  17. The constrained torsional analysis of thin-walled variable cross-section multi-cell laminated composite beams

    OpenAIRE

    Ahmed, Malik Nazir

    1999-01-01

    A Constrained Torsional Analysis of Thin-Walled Variable Cross-Section Multi-Cell Laminated Composite Beams has been undertaken . The existing Isotopic theory has been modified using the effective engineering elastic constants to cater for the Composite structures under torsional loads. The relevant computer programs for the Composite structure analysis have also been developed. The results are discussed in detail for single-cell and multi-cell prismatic/tapered beams for all [0/45/-45/90], l...

  18. Domain Walls Zoo in Supersymmetric QCD

    CERN Document Server

    Smilga, A V

    1998-01-01

    Solving numerically the equations of motion for the effective lagrangian describing supersymmetric QCD with the SU(2) gauge group, we find a menagerie of complex domain wall solutions connecting different chirally asymmetric vacua. Some of these solutions are BPS saturated walls; they exist when the mass of the matter fields does not exceed some critical value m m*, the complex walls disappear altogether and only the walls connecting a chirally asymmetric vacuum with the chirally symmetric one survive.

  19. $Spin(7)$ Compactifications and 1/4-BPS Vacua in Heterotic Supergravity

    CERN Document Server

    Angus, Stephen; Svanes, Eirik Eik

    2015-01-01

    We continue the investigation into non-maximally symmetric compactifications of the heterotic string. In particular, we consider compactifications where the internal space is allowed to depend on two or more external directions. For preservation of supersymmetry, this implies that the internal space must in general be that of a $Spin(7)$ manifold, which leads to a $1/4$-BPS four-dimensional non-supersymmetric perturbative vacuum. We find that these solutions allow for internal geometries previously excluded by the domain-wall-type solutions, and hence the resulting four-dimensional superpotential is more generic. In particular, we find an interesting resemblance to the superpotentials that appear in non-geometric flux compactifications of type II string theory. If the vacua are to be used for phenomenological applications, they must be lifted to a maximally symmetric one by some non-perturbative or higher-order effect.

  20. Stimulated cold fusion by positronium atoms, cross sections, and wall interactions in plasmas, used to diagnostics

    International Nuclear Information System (INIS)

    classically or semi classically as their origin here, but to obtain exact results a rather quantum mechanical treatment is also handled. The order of magnitude of quantum effects derived from uncertainty principle. Through this individual research introduced here, the scattering process of the γ radiation including Thomson scattering in one extreme, together with Compton scattering in other extreme leads to heating plasma media again helps to produce thermonuclear reaction yet. The absorption of the γ radiation by the plasma media included also, Rayleigh and Raman (Stokes) scattering in turn served as another agent to heat the cold plasma. Also in this paper, all the possible cross sections of the above mentioned collisions calculated where as the probability of the impact between incident γ-ray with walls, in magnetic confined devices (including tokamaks) has been taken into account and the diagnostics aspects are also discussed. In the conclusion and remarks the fruitfulness of the method elucidated. The simulation of theory is in development. (author)

  1. One-loop Amplitudes as BPS state sums

    CERN Document Server

    Florakis, Ioannis

    2013-01-01

    We review a novel method for evaluating one-loop BPS-saturated amplitudes in string theory. Contrary to traditional techniques of unfolding the fundamental domain F against the Narain lattice, which are only valid in certain regions of the moduli space and which obscure the T- duality invariance of the result, we will describe how the elliptic genus can be represented as a linear combination of certain absolutely convergent Poincar\\'e series, against which F can be unfolded. The result can be expressed as a sum of one-loop contributions of perturbative BPS-states in a manifestly T-duality invariant fashion, valid at any point of (the perturbative) moduli space. Within this framework, the singularity structure of amplitudes around points of gauge symmetry enhancement becomes crystal clear and a series of applications is given in order to better illustrate the power of this approach.

  2. The M2/M5 BPS Partition Functions from Supergravity

    CERN Document Server

    Silva, Pedro J

    2009-01-01

    In the framework of the AdS/CFT duality, we calculate the supersymmetric partition function of the superconformal field theories living in the world volume of either $N$ $M2$-branes or $N$ $M5$-branes. We used the dual supergravity partition function in a saddle point approximation over supersymmetric Black Holes. Since our BHs are written in asymptotically global $AdS_{d+1}$ co-ordinates, the dual SCFTs are in $R x S^{d}$ for $d=2,5$. The resulting partition function shows phase transitions, constraints on the phase space and allowed us to identify unstable BPS Black hole in the $AdS$ phase. This configurations should corresponds to unstable configurations in the dual theory. We also report an intriguing relation between the most general Witten Index, computed in the above theories, and our BPS partition functions.

  3. 1/8 BPS states in AdS/CFT

    International Nuclear Information System (INIS)

    We study a class of exact supersymmetric solutions of type IIB Supergravity. They have an SO(4) x SU(2) x U(1) isometry and preserve generically 4 of the 32 supersymmetries of the theory. Asymptotically AdS5 x S5 solutions in this class are dual to 1/8 BPS chiral operators which preserve the same symmetries in the N = 4 SYM theory. They are parametrized by a set of four functions that satisfy certain differential equations. We analyze the solutions to these equations in a large radius asymptotic expansion: they carry charges with respect to two U(1) KK gauge fields and their mass saturates the expected BPS bound

  4. 1/8 BPS states in AdS/CFT

    International Nuclear Information System (INIS)

    We study a class of exact supersymmetric solutions of type IIB Supergravity. They have an SO(4) x SU(2) x U(1) isometry and preserve generically 4 of the 32 supersymmetries of the theory. Asymptotically AdS5 x S5 solutions in this class are dual to 1/8 BPS chiral operators which preserve the same symmetries in the N = 4 SYM theory. They are parametrized by a set of four functions that satisfy certain differential equations. We analyze the solutions to these equations in a large radius asymptotic expansion: they carry charges with respect to two U(1) KK gauge fields and their mass saturates the expected BPS bound. (author)

  5. Nuclear binding energies from a BPS Skyrme model

    OpenAIRE

    Adam, C.; Naya, C.; Sanchez-Guillen, J.(Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), Santiago de Compostela, E-15782, Spain); Wereszczynski, A.

    2013-01-01

    Recently, within the space of generalized Skyrme models, a BPS submodel was identified which reproduces some bulk properties of nuclear matter already on a classical level and, as such, constitutes a promising field theory candidate for the detailed and reliable description of nuclei and hadrons. Here we extend and further develop these investigations by applying the model to the calculation of nuclear binding energies. Concretely, we calculate these binding energies by including the classica...

  6. Properties of non-BPS SU(3) monopoles

    International Nuclear Information System (INIS)

    This paper is concerned with magnetic monopole solutions of SU(3) Yang-Mills-Higgs system beyond the Bogomol'nyi-Prasad-Sommerfield limit. The different SU(2) embeddings, which correspond to the fundamental monopoles, as well the embedding along composite root are studied. The interaction of two different fundamental monopoles is considered. Dissolution of a single fundamental non-BPS SU(3) monopole in the limit of the minimal symmetry breaking is analyzed. (author)

  7. BPS monopole in the space of boundary conditions

    International Nuclear Information System (INIS)

    The space of all possible boundary conditions that respect the self-adjointness of the Hamiltonian operator is known to be given by the group manifold U(2) in one-dimensional quantum mechanics. In this paper we study non-Abelian Berry’s connections in the space of boundary conditions in a simple quantum mechanical system. We consider a system for a free spinless particle on a circle with two point-like interactions described by the U(2) × U(2) family of boundary conditions. We show that, for a certain SU(2) ⊂ U(2) × U(2) subfamily of boundary conditions, all the energy levels become doubly-degenerate thanks to the so-called higher-derivative supersymmetry, and the non-Abelian Berry’s connection in the ground-state sector is given by the Bogomolny–Prasad–Sommerfield (BPS) monopole of SU(2) Yang–Mills–Higgs theory. We also show that, in the ground-state sector of this quantum mechanical model, the matrix elements of the position operator give the adjoint Higgs field that satisfies the BPS equation. It is also discussed that Berry’s connections in the excited-state sectors are given by non-BPS ’t Hooft–Polyakov monopoles. (paper)

  8. Some exact BPS solutions for exotic vortices and monopoles

    Science.gov (United States)

    Ramadhan, Handhika S.

    2016-07-01

    We present several analytical solutions of BPS vortices and monopoles in the generalized Abelian Maxwell-Higgs and Yang-Mills-Higgs theories, respectively. These models have recently been extensively studied and several exact solutions have already been obtained in [1,2]. In each theory, the dynamics is controlled by the additional two positive scalar-field-dependent functions, f (| ϕ |) and w (| ϕ |). For the case of vortices, we work in the ordinary symmetry-breaking Higgs potential, while for the case of monopoles we have the ordinary condition of the Prasad-Sommerfield limit. Our results generalize the exact solutions found previously. We also present solutions for BPS vortices with higher winding number. These solutions suffer from the condition that w (| ϕ |) has negative value at some finite range of r, but we argue that since it satisfies the weaker positive-value conditions then the corresponding energy density is still positive-definite and, thus, they are acceptable BPS solutions.

  9. Diet and its role in interstitial cystitis/bladder pain syndrome (IC/BPS) and comorbid conditions.

    Science.gov (United States)

    Friedlander, Justin I; Shorter, Barbara; Moldwin, Robert M

    2012-06-01

    What's known on the subject? and What does the study add? Nearly 90% of patients with interstitial cystitis/bladder pain syndrome (IC/BPS) report sensitivities to a wide variety of dietary comestibles. Current questionnaire-based literature suggests that citrus fruits, tomatoes, vitamin C, artificial sweeteners, coffee, tea, carbonated and alcoholic beverages, and spicy foods tend to exacerbate symptoms, while calcium glycerophosphate and sodium bicarbonate tend to improve symptoms. At present we recommend employing a controlled method to determine dietary sensitivities, such as an elimination diet, in order to identify sensitivities while at the same time maintain optimal nutritional intake. We review current literature with regard to diet's effect upon IC/BPS and common comorbidities (irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, neuropathic pain, vulvodynia, and headache) with a focus upon questionnaire-based investigations. We discuss the pathologic mechanisms that may link diet and IC/BPS related-pain, concentrating upon specific comestibles such as acidic foods, foods high in potassium, caffeine, and alcohol. Up to 90% of patients with interstitial cystitis/bladder pain syndrome (IC/BPS) report sensitivities to a wide variety of comestibles.   Pathological mechanisms suggested to be responsible for the relationship between dietary intake and symptom exacerbation include peripheral and/or central neural upregulation, bladder epithelial dysfunction, and organ 'cross-talk', amongst others.   Current questionnaire-based data suggests that citrus fruits, tomatoes, vitamin C, artificial sweeteners, coffee, tea, carbonated and alcoholic beverages, and spicy foods tend to exacerbate symptoms, while calcium glycerophosphate and sodium bicarbonate tend to improve symptoms. Specific comestible sensitivities varied between patients and may have been influenced by comorbid conditions. This suggests that a controlled method to determine dietary

  10. Domain Wall Equations, Hessian of Superpotential, and Bogomol'nyi Bounds

    CERN Document Server

    Chen, Shouxin

    2015-01-01

    An important question concerning the classical solutions of the equations of motion arising in quantum field theories at the BPS critical coupling is whether all finite-energy solutions are necessarily BPS. In this paper we present a study of this basic question in the context of the domain wall equations whose potential is induced from a superpotential so that the ground states are the critical points of the superpotential. We prove that the definiteness of the Hessian of the superpotential suffices to ensure that all finite-energy domain-wall solutions are BPS. We give several examples to show that such a BPS property may fail such that non-BPS solutions exist when the Hessian of the superpotential is indefinite.

  11. Model Stacking (MOST) technique applied in cross-hole ERT field data for the detection of Thessaloniki ancient walls' depth

    Science.gov (United States)

    Leontarakis, Konstantinos; Apostolopoulos, George V.

    2013-06-01

    A cross-hole Electrical Resistivity Tomography (ERT) study was undertaken near the center of Thessaloniki in order to detect the depth of the existing city walls in the planned route of the new city underground train. This cross-hole setup was used for a study of measurements with various electrode arrays in real urban field conditions to evaluate the resolution of the models which is produced by each array and the reliability of the models which is produced by the newly published "MOST" technique. The pole-tripole array (C2-C1P1P2) produces high resolution models, even when only borehole electrodes are used. The bipole-bipole C1C2-P1P2 array, when used for cross-hole measurements only, produces higher resolution models compared to the C1P1-C2P2 array, even with a lower signal-to-noise ratio, which can result in extremely high RMS error, when noise, systematic or not, must be faced. The models of both arrays are greatly improved by the use of surface electrodes. The pole-bipole array (C1-P1P2) is proved to be less accurate in imaging and quite unstable to the noisy urban environment and to systematic errors. Furthermore, the Model Stacking (MOST) interpretation technique leads to better results with models of greater resolution and fewer artifacts compared even with the combined data inversion. Finally, the ERT cross-hole analysis has been reliable in detecting the city walls.

  12. Domain Walls, Black Holes and Supersymmetric Quantum Mechanics.; TOPICAL

    International Nuclear Information System (INIS)

    Supersymmetric solutions, such as BPS domain walls or black holes, in four- and five-dimensional supergravity theories with eight supercharges can be described by effective quantum mechanics with a potential term. We show how properties of the latter theory can help us to learn about the physics of supersymmetric vacua and BPS solutions in these supergravity theories. The general approach is illustrated in a number of specific examples where scalar fields of matter multiplets take values in symmetric coset spaces

  13. Preparation of Hydroxypropyl-β-cyclodextrin Cross-linked Multi-walled Carbon Nanotubes and Their Application in Enantioseparation of Clenbuterol

    Institute of Scientific and Technical Information of China (English)

    Yu Jingang; Huang Dushu; Huang Kelong; Hong Yong

    2011-01-01

    A method of cross-linking multi-walled carbon nanotubes by a nucleophilic substitution of brominated multi-walled carbon nanotubes using hydroxypropyl-β-cyclodextrin anions was studied. The modified multi-walled carbon nanotube samples were characterized using thermogravimetric analysis, energy-dispersive X-ray spectros-copy, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. The hydroxypropyi-β-cyclodextrin modified multi-walled carbon nanotubes were used as a chiral stationary phase additive for thin-layer chromatography to separate clenbuterol enantiomers, and the chiral separation factor was increased.

  14. On the Moduli Space of non-BPS Attractors for N=2 Symmetric Manifolds

    CERN Document Server

    Ferrara, Sergio

    2007-01-01

    We study the ``flat'' directions of non-BPS extremal black hole attractors for N=2, d=4 supergravities whose vector multiplets' scalar manifold is endowed with homogeneous symmetric special Kahler geometry. The non-BPS attractors with non-vanishing central charge have a moduli space described by real special geometry (and thus related to the d=5 parent theory), whereas the moduli spaces of non-BPS attractors with vanishing central charge are certain Kahler homogeneous symmetric manifolds. The moduli spaces of the non-BPS attractors of the corresponding N=2, d=5 theories are also indicated, and shown to be rank-1 homogeneous symmetric manifolds.

  15. BPS Limit of Multi- D- and DF-strings in Boundary String Field Theory

    OpenAIRE

    Go, Gyungchoon; Ishida, Akira; Kim, Yoonbai

    2007-01-01

    A BPS limit is systematically derived for straight multi- D- and DF-strings from the D3D3bar system in the context of boundary superstring field theory. The BPS limit is obtained in the limit of thin D(F)-strings, where the Bogomolnyi equation supports singular static multi-D(F)-string solutions. For the BPS multi-string configurations with arbitrary separations, BPS sum rule is fulfilled under a Gaussian type tachyon potential and reproduces exactly the descent relation. For the DF-strings (...

  16. Topological duality between vortices and planar Skyrmions in BPS theories with area-preserving diffeomorphism symmetries

    Science.gov (United States)

    Adam, C.; Sanchez-Guillen, J.; Wereszczynski, A.; Zakrzewski, W. J.

    2013-01-01

    The Bogomol’nyi-Prasad-Sommerfield (BPS) baby Skyrme models are submodels of baby Skyrme models, where the nonlinear sigma model term is suppressed. They have Skyrmion solutions saturating a BPS bound, and the corresponding static energy functional is invariant under area-preserving diffeomorphisms (APDs). Here we show that the solitons in the BPS baby Skyrme model, which carry a nontrivial topological charge Qb∈π2(S2) (a winding number), are dual to vortices in a BPS vortex model with a topological charge Qv∈π1(S1) (a vortex number), in the sense that there is a map between the BPS solutions of the two models. The corresponding energy densities of the BPS solutions of the two models are identical. A further consequence of the duality is that the dual BPS vortex models inherit the BPS property and the infinitely many symmetries (APDs) of the BPS baby Skyrme models. Finally, we demonstrate that the same topological duality continues to hold for the U(1) gauged versions of the models.

  17. Topological duality between vortices and planar skyrmions in BPS theories with APD symmetries

    CERN Document Server

    Adam, C; Wereszczynski, A; Zakrzewski, W J

    2012-01-01

    The BPS baby Skyrme models are submodels of baby Skyrme models, where the nonlinear sigma model term is suppressed. They have skyrmion solutions saturating a BPS bound, and the corresponding static energy functional is invariant under area-preserving diffeomorphisms (APDs). Here we show that the solitons in the BPS baby Skyrme model, which carry a nontrivial topological charge $Q_{b} \\in \\pi_2(S^2)$ (a winding number), are dual to vortices in a BPS vortex model with a topological charge $Q_{v}\\in \\pi_1(S^1)$ (a vortex number), in the sense that there is a map between the BPS solutions of the two models. The corresponding energy densities of the BPS solutions of the two models are identical. A further consequence of the duality is that the dual BPS vortex models inherit the BPS property and the infinitely many symmetries (APDs) of the BPS baby Skyrme models. Finally, we demonstrate that the same topological duality continues to hold for the U(1) gauged versions of the models.

  18. Topological duality between vortices and planar skyrmions in BPS theories with APD symmetries

    OpenAIRE

    Adam, C.; Sanchez-Guillen, J.; Wereszczynski, A.; Zakrzewski, W. J.

    2012-01-01

    The BPS baby Skyrme models are submodels of baby Skyrme models, where the nonlinear sigma model term is suppressed. They have skyrmion solutions saturating a BPS bound, and the corresponding static energy functional is invariant under area-preserving diffeomorphisms (APDs). Here we show that the solitons in the BPS baby Skyrme model, which carry a nontrivial topological charge $Q_{b} \\in \\pi_2(S^2)$ (a winding number), are dual to vortices in a BPS vortex model with a topological charge $Q_{v...

  19. Twistor Parametrization of Locally BPS Super-Wilson Loops

    OpenAIRE

    C. Vergu

    2016-01-01

    We consider the kinematics of the locally BPS super-Wilson loop in $\\mathcal{N}=4$ super-Yang-Mills with scalar coupling from a twistorial point of view. We find that the kinematics can be described either as supersymmetrized pure spinors or as a point in $G_{2\\vert 2}(4\\vert 4) \\times G_{2\\vert 2}(4\\vert 4)$. In this description of the kinematics the scalar--scalar correlation function appearing in the one-loop evaluation of the super-Wilson loop can be neatly written as a sum of four super-...

  20. Twistor Parametrization of Locally BPS Super-Wilson Loops

    CERN Document Server

    Vergu, C

    2016-01-01

    We consider the kinematics of the locally BPS super-Wilson loop in $\\mathcal{N}=4$ super-Yang-Mills with scalar coupling from a twistorial point of view. We find that the kinematics can be described either as supersymmetrized pure spinors or as a point in $G_{2\\vert 2}(4\\vert 4) \\times G_{2\\vert 2}(4\\vert 4)$. In this description of the kinematics the scalar--scalar correlation function appearing in the one-loop evaluation of the super-Wilson loop can be neatly written as a sum of four super-determinants.

  1. Design of BPS digital frontend for software defined radio receiver

    Institute of Scientific and Technical Information of China (English)

    王洪梅; KIM Jae-hyung; 王法广; LEE Sang-hyuk; 王雪松

    2015-01-01

    In radio receivers, complete implementation of the software defined radio (SDR) concept is mainly limited by frontend. Based on bandpass sampling (BPS) theory, a flexible digital frontend (DFE) platform for SDR receiver is designed. In order to increase the processing speed, Gigabit Ethernet was applied in the platform at speed of 5×108 bit/s. By appropriate design of interpolant according to the position of input RF signals, multi-band receiving can be realized in the platform with suppression more than 35 dB without changing hardware.

  2. Improved concept models for straight thin-walled columns with box cross section

    Institute of Scientific and Technical Information of China (English)

    Yu-cheng LIU

    2008-01-01

    This paper focuses on developing improved concept models for straight thin-walled box sectional columns which can better predict the peak crushing force that occurs during crashworthiness analyses.We develop a nonlinear translational spring based on previous research and apply such a spring element to build the enhanced concept models.The work presented in this article is developed on the basis of the publication of the author(Liu and Day,2006b)and has been applied in a crashworthiness design issue,which is presented by the author in another paper(Liu,2008).

  3. Marginal Stability and the Metamorphosis of BPS States

    CERN Document Server

    Ritz, A; Vainshtein, A I; Voloshin, M B; Ritz, Adam; Shifman, Mikhail; Vainshtein, Arkady; Voloshin, Mikhail

    2001-01-01

    We discuss the restructuring of the BPS spectrum which occurs on certain submanifolds of the moduli/parameter space -- the curves of the marginal stability (CMS) -- using quasiclassical methods. We argue that in general a `composite' BPS soliton swells in coordinate space as one approaches the CMS and that, as a bound state of two `primary' solitons, its dynamics in this region is determined by supersymmetric quantum mechanics with a short range potential. Near the CMS the bound state resembles a deuteron with a wave function which is highly spread out. Precisely on the CMS the bound state level reaches the continuum, the composite state delocalizes in coordinate space, and restructuring of the spectrum can occur. We present a detailed analysis of this behavior in a two-dimensional N=2 Wess-Zumino model with two chiral fields, and then discuss how it arises in the context of `composite' dyons near weak coupling CMS curves in N=2 supersymmetric gauge theories. We also consider exceptional cases where some stat...

  4. BPS states in the duality web of the Omega deformation

    Science.gov (United States)

    Hellerman, Simeon; Orlando, Domenico; Reffert, Susanne

    2013-06-01

    In this note, we study different limits of an Ω-deformed (2, 0) six-dimensional gauge theory realized in an M-theory fluxtrap background. Via a chain of dualities, we connect the Ω-deformed sym to a new four-dimensional gauge theory which we refer to as the reciprocal gauge theory. This theory has several properties in common with Liouville field theory, such as its gauge coupling b 2 = ɛ 2/ ɛ 1, and its behavior under S-duality. Finally, we realize the bps states on the sym side of the agt correspondence and follow them along the chain of dualities. In the fluxtrap frame, we are dealing with two distinct types of states localized in different radial positions, while in the reciprocal frame, we find single states carrying both charges localized in one place which appear to be perturbatively stable. Our microscopic picture of the small- b limit exhibits semiclassically bps bound states, which are not visible at the level of the partition function.

  5. BPS States in the Duality Web of the Omega deformation

    CERN Document Server

    Hellerman, Simeon; Reffert, Susanne

    2013-01-01

    In this note, we study different limits of an Omega-deformed (2,0) six-dimensional gauge theory realized in a M-theory fluxtrap background. Via a chain of dualities, we connect the Omega-deformed SYM to a new four-dimensional gauge theory which we refer to as the reciprocal gauge theory. This theory has several properties in common with Liouville field theory, such as its gauge coupling b^2 =\\epsilon_2 / \\epsilon_1, and its behavior under S-duality. Finally, we realize the BPS states on the SYM side of the AGT correspondence and follow them along the chain of dualities. In the fluxtrap frame, we are dealing with two distinct types of states localized in different radial positions, while in the reciprocal frame, we find single states carrying both charges localized in one place which appear to be perturbatively stable. Our microscopic picture of the small-b limit exhibits semiclassically BPS bound states, which are not visible at the level of the partition function.

  6. BPS black hole horizons in N=2 gauged supergravity

    International Nuclear Information System (INIS)

    We study static BPS black hole horizons in four dimensional N=2 gauged supergravity coupled to nv-vector multiplets and with an arbitrary cubic prepotential. We work in a symplectically covariant formalism which allows for both electric and magnetic gauging parameters as well as dyonic background charges and obtain the general solution to the BPS equations for horizons of the form AdS2×Σg. In particular this means we solve for the scalar fields as well as the metric of these black holes as a function of the gauging parameters and background charges. When the special Kähler manifold is a symmetric space, our solution is completely explicit and the entropy is related to the familiar quartic invariant. For more general models our solution is implicit up to a set of holomorphic quadratic equations. For particular models which have known embeddings in M-theory, we derive new horizon geometries with dyonic charges and numerically construct black hole solutions. These correspond to M2-branes wrapped on a Riemann surface in a local Calabi-Yau five-fold with internal spin

  7. Scaling BPS Solutions and pure-Higgs States

    CERN Document Server

    Bena, Iosif; de Boer, Jan; El-Showk, Sheer; Bleeken, Dieter Van den

    2012-01-01

    Depending on the value of the coupling, BPS states of type II string theory compactified on a Calabi-Yau manifold can be described as multicenter supergravity solutions or as states on the Coulomb or the Higgs branch of a quiver gauge theory. While the Coulomb-branch states can be mapped one-to-one to supergravity states, this is not automatically so for Higgs-branch states. In this paper we explicitly compute the BPS spectrum of the Higgs branch of a three-center quiver with a closed loop, and identify the subset of states that are in one-to-one correspondence with Coulomb/supergravity multicenter states. We also show that there exist additional "pure-Higgs" states, that exist if and only if the charges of the centers can form a scaling solution. Using generating function techniques we compute the large charge degeneracy of the "pure-Higgs" sector and show that it is always exponential. We also construct the map between Higgs- and Coulomb-branch states, discuss its relation to the Higgs-Coulomb map of one of...

  8. Demonstration of a cell wall antigen cross-reacting with cryptococcal polysaccharide in experimental disseminated trichosporonosis.

    OpenAIRE

    Melcher, G P; Reed, K D; Rinaldi, M. G.; Lee, J. W.; Pizzo, P A; Walsh, T. J.

    1991-01-01

    Patients with disseminated infections caused by Trichosporon beigelii have a circulating antigen that cross-reacts with the polysaccharide capsule of Cryptococcus neoformans. We studied the localization of this antigen by immunoelectron microscopy in a rabbit model of experimental disseminated trichosporonosis. Deparaffinized lung sections were examined by using a murine monoclonal anti-cryptococcal polysaccharide antibody and colloidal gold particles coated with goat antibody to murine immun...

  9. Effect of bioactive peptides (BPs) on the development of Pacific white shrimp ( Litopenaeus vannamei Boone, 1931)

    Science.gov (United States)

    Wang, Guangjun; Yu, Ermeng; Li, Zhifei; Yu, Deguang; Wang, Haiying; Gong, Wangbao

    2016-06-01

    The present study was conducted to evaluate the feasibility of replacing fish meal (FM) with bioactive peptides (BPs) in diet of white shrimp ( Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0% (control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate (WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con ( P levels of acid phosphatase (ACP), lysozyme (LZM), superoxide dismutase (SOD), phenol oxidase (PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in pH and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.

  10. Effect of activation cross-section uncertainties on the radiological assessment of the MFE/DEMO first wall

    International Nuclear Information System (INIS)

    A Monte Carlo procedure has been applied in this work in order to address the impact of activation cross-sections (XS) uncertainties on contact dose rate and decay heat calculations for the outboard first wall (FW) of a magnetic fusion energy (MFE) demonstration (DEMO) reactor. The XSs inducing the major uncertainty in the prediction of activation related quantities have been identified. Results have shown that for times corresponding to maintenance activities the uncertainties effect is insignificant since the dominant XSs involved in these calculations are based on accurate experimental data evaluations. However, for times corresponding to waste management/recycling activities, the errors induced by the XSs uncertainties, which in this case are evaluated using systematic models, must be considered. It has been found that two particular isotopes, 6Co and 94Nb, are key contributors to the global DEMO FW activation uncertainty results. In these cases, the benefit from further improvements in the accuracy of the critical reaction XSs is discussed

  11. Effect of Activation Cross Section Uncertainties on the Radiological Assessment of the MFE/DEMO First Wall

    International Nuclear Information System (INIS)

    A Monte Carlo procedure has been applied in this work in order to address the impact of activation cross sections (XS) uncertainties on contact dose rate and decay heat calculations for the outboard first wall (FW) of a magnetic fusion energy (MFE) demonstration (DEMO) reactor. The XSs inducing the major uncertainty in the prediction of activation related quantities have been identified. Results have shown that for times corresponding to maintenance activities the uncertainties effect is insignificant since the dominant XSs involved in these calculations are based on accurate experimental data evaluations. However, for times corresponding to waste management/recycling activities, the errors induced by the XSs uncertainties, which in this case are evaluated using systematic models, must be considered. It has been found that two particular isotopes, 60Co and 94Nb, are key contributors to the global DEMO FW activation uncertainty results. In these cases, the benefit from further improvements in the accuracy of the critical reaction XSs is discussed

  12. Silylesterification of oxidized multi-wall carbon nanotubes by catalyzed dehydrogenative cross-coupling between carboxylic and hydrosilane functions

    Science.gov (United States)

    Seffer, J.-F.; Detriche, S.; Nagy, J. B.; Delhalle, J.; Mekhalif, Z.

    2014-06-01

    Surface modification of oxidized carbon nanotubes (O-CNTs) with silicon based anchoring groups (R-SiR3) is a relatively uncommon approach of the CNTs functionalization. Hydrosilane derivatives constitute an attractive subclass of compounds for silanization reactions on the CNTs surface. In this work, we report on the ZnCl2 catalytically controlled reaction (hydrosilane dehydrogenative cross-coupling, DHCC) of fluorinated hydrosilane probes with the carboxylic functions present on the surface of oxidized multi-wall carbon nanotubes. Carbon nanotubes functionalized with essentially alcohol groups are also used to compare the selectivity of zinc chloride toward carboxylic groups. To assess the efficiency of functionalization, X-ray Photoelectron Spectroscopy is used to determine the qualitative and quantitative composition of the different samples. Solubility tests on the oxidized and silanized MWNTs are also carried out in the framework of the Hansen Solubility Parameters (HSP) theory to apprehend at another scale the effect of DHCC.

  13. System design and development of a low data rate voice (1200 bps) rate converter

    Science.gov (United States)

    Hauser, J. P.

    1992-09-01

    This report presents both a high level and a detailed design for a low data rate voice Rate Converter (RC). On the transmit side, converter reduces 2400 bps voice generated by an Advanced Narrowband Digital Voice Terminal (ANDVT) to a 1200 bps bit stream. On the receive Bide it converts the 1200 bps bit stream back to a 2400 bps stream in ANDVT format. Rate reduction is accomplished with little degradation to the inherent voice quality of the ANDVT. This primary focus is upon the real-time software design which is implemented using VxWorks, a real-time, multi-tasking operating system and development environment. The high level design defines four tasks, each having its own execution thread and its own pipe to facilitate inter-task communication. The Supervisor Task performs initialization and managers input of commands and data to the RC. The Compressor Task reduces a 2400 bps bit stream to 1200 bps while the Decompressor Task converts from 1200 bps back to 2400 bps. The Output Task manages the output of data from the RC. Latter sections of this report describe the software in detail.

  14. Ultrasonic inspection of steam generator tubing for cracks, wall thinning and cross-sectional deformation

    International Nuclear Information System (INIS)

    Periodic inspection of steam generator tubing is an important consideration in the efficient operation of a power generating facility. Since the operating life of these generators is finite, failures will occur. Due to the chemistry of the environment, thermal cycling, and other factors, flaws may develop that can cause rapid deterioration of the tubing while the overall performance of the unit may appear normal. In earlier presentation, the authors presented an ultrasonic bore-side array transducer which can be used with a conventional flaw detector instrument for the location of circumferential crack type defects on the outside tube surface. since that time, much additional experience has been gained on the performance of these probes. Probe performance has been characterized using fatigue crack samples and these results are reviewed. Probes have also been developed having 16 elements for use in larger diameter (25 mm) tubes. The bore-side array concept has been expanded to normal incidence tube well inspection allowing simultaneous wall thickness and eccentricity measurement which is very useful in the assessment of tube wastage and deformation. Preliminary data obtained in this area is presented

  15. BPS String Webs in the 6-dim (2,0) Theories

    CERN Document Server

    Lee, K M; Lee, Ki-Myeong; Yee, Ho-Ung

    2007-01-01

    In the Coulomb phase of the 6-dim (2,0) superconformal theories, the 1/4, 1/8, 1/16 BPS selfdual string webs are argued to exist such that the spatial SO(5) and internal SO(5) rotations are correlated. The basic constituents are 1/2 BPS strings and 1/4 BPS string junctions. One support comes from the existence of the similar BPS dyonic monostring webs in 5-dim maximally supersymmetric gauge theories. Another comes from the study of the supersymmetry of the intersecting M2 brane stripes terminating on M5 branes. We also discuss the related BPS webs in little string theories and other theories.

  16. Crossing the Vascular Wall: Common and Unique Mechanisms Exploited by Different Leukocyte Subsets during Extravasation

    Directory of Open Access Journals (Sweden)

    Michael Schnoor

    2015-01-01

    Full Text Available Leukocyte extravasation is one of the essential and first steps during the initiation of inflammation. Therefore, a better understanding of the key molecules that regulate this process may help to develop novel therapeutics for treatment of inflammation-based diseases such as atherosclerosis or rheumatoid arthritis. The endothelial adhesion molecules ICAM-1 and VCAM-1 are known as the central mediators of leukocyte adhesion to and transmigration across the endothelium. Engagement of these molecules by their leukocyte integrin receptors initiates the activation of several signaling pathways within both leukocytes and endothelium. Several of such events have been described to occur during transendothelial migration of all leukocyte subsets, whereas other mechanisms are known only for a single leukocyte subset. Here, we summarize current knowledge on regulatory mechanisms of leukocyte extravasation from a leukocyte and endothelial point of view, respectively. Specifically, we will focus on highlighting common and unique mechanisms that specific leukocyte subsets exploit to succeed in crossing endothelial monolayers.

  17. Effect of cross-linkable polymer on the morphology and properties of transparent multi-walled carbon nanotube conductive films

    International Nuclear Information System (INIS)

    In this study, we fabricated optically transparent and electrically conductive multi-walled carbon nanotube (MWCNT) thin films using a spray-coating technique. The transparency and the electrical resistance of thin film are dependent on the nanotube content deposited on the polyethylene terephthalate (PET) substrate. Poly(acrylic acid) (PAA) and poly(N-vinyl pyrrolidone) (PVP) were used as adhesion promoters to improve MWCNT coating more significantly. The cross-linked polymer resulted in a superior bond between the MWCNTs and the substrates. The surface electrical resistance was significantly lower than the original sheet after nitric acid (HNO3) treatment because of the removed surfactant and the increased interconnecting networks of MWCNT bundles, thus improving the electrical and optical properties of the films. Stronger interaction between the MWCNTs and the substrates resulted in lower decomposition of the polymer chain and less amounts of MWCNTs separated into the HNO3 solution. The lower sheet electrical resistance of PVP/PAA-g-MWCNT conductive films on the PET substrate was because of a more complete conductive path with the cross-linked polymer than that without. Such an improved sheet of electrical resistance varied from 8.83 x 104 Ω/□ to 2.65 x 103 Ω/□ with 5.0 wt.% PVP/PAA-g-MWCNT sprayed on the PET after acid treatment.

  18. Effect of cross-linkable polymer on the morphology and properties of transparent multi-walled carbon nanotube conductive films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuan-Li; Tien, Hsi-Wen [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Ma, Chen-Chi M., E-mail: ccma@che.nthu.edu.tw [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Teng, Chih-Chun [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Yu, Yi-Hsiuan [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Chemical Systems Research Division, Chung Shan Institute of Science and Technology, Tao Yuan 32546, Taiwan (China); Yang, Shin-Yi [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China); Wei, Ming-Hsiung [Chemical Systems Research Division, Chung Shan Institute of Science and Technology, Tao Yuan 32546, Taiwan (China); Wu, Sheng-Yen [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30043, Taiwan (China)

    2011-10-15

    In this study, we fabricated optically transparent and electrically conductive multi-walled carbon nanotube (MWCNT) thin films using a spray-coating technique. The transparency and the electrical resistance of thin film are dependent on the nanotube content deposited on the polyethylene terephthalate (PET) substrate. Poly(acrylic acid) (PAA) and poly(N-vinyl pyrrolidone) (PVP) were used as adhesion promoters to improve MWCNT coating more significantly. The cross-linked polymer resulted in a superior bond between the MWCNTs and the substrates. The surface electrical resistance was significantly lower than the original sheet after nitric acid (HNO{sub 3}) treatment because of the removed surfactant and the increased interconnecting networks of MWCNT bundles, thus improving the electrical and optical properties of the films. Stronger interaction between the MWCNTs and the substrates resulted in lower decomposition of the polymer chain and less amounts of MWCNTs separated into the HNO{sub 3} solution. The lower sheet electrical resistance of PVP/PAA-g-MWCNT conductive films on the PET substrate was because of a more complete conductive path with the cross-linked polymer than that without. Such an improved sheet of electrical resistance varied from 8.83 x 10{sup 4} {Omega}/{open_square} to 2.65 x 10{sup 3} {Omega}/{open_square} with 5.0 wt.% PVP/PAA-g-MWCNT sprayed on the PET after acid treatment.

  19. In-plane current induced domain wall nucleation and its stochasticity in perpendicular magnetic anisotropy Hall cross structures

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, P.; Murapaka, C.; Lim, G. J.; Lew, W. S., E-mail: wensiang@ntu.edu.sg [School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)

    2015-11-09

    Hall cross structures in magnetic nanowires are commonly used for electrical detection of magnetization reversal in which a domain wall (DW) is conventionally nucleated by a local Oersted field. In this letter, we demonstrate DW nucleation in Co/Ni perpendicular magnetic anisotropy nanowire at the magnetic Hall cross junction. The DWs are nucleated by applying an in-plane pulsed current through the nanowire without the need of a local Oersted field. The change in Hall resistance, detected using anomalous Hall effect, is governed by the magnetic volume switched at the Hall junction, which can be tuned by varying the magnitude of the applied current density and pulse width. The nucleated DWs are driven simultaneously under the spin transfer torque effect when the applied current density is above a threshold. The possibility of multiple DW generation and variation in magnetic volume switched makes nucleation process stochastic in nature. The in-plane current induced stochastic nature of DW generation may find applications in random number generation.

  20. Liouville Equation in 1/8 BPS Geometries

    CERN Document Server

    Mitsuka, Yoshihiro

    2008-01-01

    We investigate the 1/8 BPS geometries with SU(2) x U(1) x SO(4) x R symmetry in IIB supergravity which were classified by Gava et al, (hep-th/0611065). It is desirable to have a complete set of differential equations imposed on the controlling functions such that they are not only necessary but also sufficient to produce supergravity solutions with those symmetries. We work on this issue and find a new differential equation for the controlling functions. For a special case, we exhaust all the remaining constraints and show that they reduce to one Liouville equation. The solutions of this equation produce geometries which are locally equivalent to the near horizon geometries of intersecting D3-branes.

  1. Non-BPS multi-bubble microstate geometries

    CERN Document Server

    Bena, Iosif; Katmadas, Stefanos; Turton, David

    2015-01-01

    We construct the first smooth horizonless supergravity solutions that have two topologically-nontrivial three-cycles supported by flux, and that have the same mass and charges as a non-extremal D1-D5-P black hole. Our configurations are solutions to six-dimensional ungauged supergravity coupled to a tensor multiplet, and uplift to solutions of Type IIB supergravity. The solutions represent multi-center generalizations of the non-BPS solutions of Jejjala, Madden, Ross, and Titchener, which have over-rotating angular momenta. By adding an additional Gibbons-Hawking center, we succeed in lowering one of the two angular momenta below the cosmic censorship bound, and bringing the other very close to this bound. Our results demonstrate that it is possible to construct multi-center horizonless solutions corresponding to non-extremal black holes, and offer the prospect of ultimately establishing that finite-temperature black holes have nontrivial structure at the horizon.

  2. Non-BPS multi-bubble microstate geometries

    Science.gov (United States)

    Bena, Iosif; Bossard, Guillaume; Katmadas, Stefanos; Turton, David

    2016-02-01

    We construct the first smooth horizonless supergravity solutions that have two topologically-nontrivial three-cycles supported by flux, and that have the same mass and charges as a non-extremal D1-D5-P black hole. Our configurations are solutions to six-dimensional ungauged supergravity coupled to a tensor multiplet, and uplift to solutions of Type IIB supergravity. The solutions represent multi-center generalizations of the non-BPS solutions of Jejjala, Madden, Ross, and Titchener, which have over-rotating angular momenta. By adding an additional Gibbons-Hawking center, we succeed in lowering one of the two angular momenta below the cosmic censorship bound, and bringing the other very close to this bound. Our results demonstrate that it is possible to construct multi-center horizonless solutions corresponding to non-extremal black holes, and offer the prospect of ultimately establishing that finite-temperature black holes have nontrivial structure at the horizon.

  3. Quantum Holonomies from Spectral Networks and Framed BPS States

    Science.gov (United States)

    Gabella, Maxime

    2016-08-01

    We propose a method for determining the spins of BPS states supported on line defects in 4d {{N}=2} theories of class S. Via the 2d-4d correspondence, this translates to the construction of quantum holonomies on a punctured Riemann surface {{C}} . Our approach combines the technology of spectral networks, which decomposes flat {GL(K,{C})} -connections on {{C}} in terms of flat abelian connections on a K-fold cover of {{C}} , and the skein algebra in the 3-manifold {{C} × [0,1]} , which expresses the representation theory of the quantum group U q (gl K ). With any path on {{C}} , the quantum holonomy associates a positive Laurent polynomial in the quantized Fock-Goncharov coordinates of higher Teichmüller space. This confirms various positivity conjectures in physics and mathematics.

  4. Do all BPS black hole microstates carry zero angular momentum?

    Science.gov (United States)

    Chowdhury, Abhishek; Garavuso, Richard S.; Mondal, Swapnamay; Sen, Ashoke

    2016-04-01

    From the analysis of the near horizon geometry and supersymmetry algebra it has been argued that all the microstates of single centered BPS black holes with four unbroken supersymmetries carry zero angular momentum in the region of the moduli space where the black hole description is valid. A stronger form of the conjecture would be that the result holds for any sufficiently generic point in the moduli space. In this paper we set out to test this conjecture for a class of black hole microstates in type II string theory on T 6, represented by four stacks of D-branes wrapped on various cycles of T 6. For this system the above conjecture translates to the statement that the moduli space of classical vacua must be a collection of points. Explicit analysis of systems carrying a low number of D-branes supports this conjecture.

  5. Quantum lift of non-BPS flat directions

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, S. [INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 4000044 Frascati (Italy)], E-mail: bellucci@lnf.infn.it; Ferrara, S. [INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 4000044 Frascati (Italy); Physics Department, Theory Unit, CERN, CH 1211, Geneva 23 (Switzerland); Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720 (United States)], E-mail: sergio.ferrara@cern.ch; Marrani, A. [INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 4000044 Frascati (Italy); Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305-4060 (United States)], E-mail: marrani@lnf.infn.it; Shcherbakov, A. [INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 4000044 Frascati (Italy); Museo Storico della Fisica e Centro Studi e Ricerche ' Enrico Fermi' Via Panisperna 89A, 00184 Roma (Italy)], E-mail: ashcherb@lnf.infn.it

    2009-02-09

    We study N=2, d=4 attractor equations for the quantum corrected two-moduli prepotential F=st{sup 2}+i{lambda}, with {lambda} real, which is the only correction which preserves the axion shift symmetry and modifies the geometry. In the classical case the black hole effective potential is known to have a flat direction. We found that in the presence of D0-D6 branes the black hole potential exhibits a flat direction in the quantum case as well. It corresponds to non-BPS Z{ne}0 solutions to the attractor equations. Unlike the classical case, the solutions acquire non-zero values of the axion field. For the cases of D0-D4 and D2-D6 branes the classical flat direction reduces to separate critical points which turn out to have a vanishing axion field.

  6. Quantum Holonomies from Spectral Networks and Framed BPS States

    CERN Document Server

    Gabella, Maxime

    2016-01-01

    We propose a method for determining the spins of BPS states supported on line defects in 4d $\\mathcal{N}=2$ theories of class S. Via the 2d-4d correspondence, this translates to the construction of quantum holonomies on a punctured Riemann surface $\\mathcal{C}$. Our approach combines the technology of spectral networks, which decomposes flat $GL(K,\\mathbb{C})$-connections on $\\mathcal{C}$ in terms of flat abelian connections on a $K$-fold cover of $\\mathcal{C}$, and the skein algebra in the 3-manifold $\\mathcal{C}\\times [0,1]$, which expresses the representation theory of the quantum group $U_q(gl_K)$. With any path on $\\mathcal{C}$, the quantum holonomy associates a positive Laurent polynomial in the quantized Fock-Goncharov coordinates of higher Teichm\\"uller space. This confirms various positivity conjectures in physics and mathematics.

  7. Wall effects on the cross-buoyancy around a square cylinder in the steady regime

    Directory of Open Access Journals (Sweden)

    A. K. Dhiman

    2012-06-01

    Full Text Available The effects of blockage ratio on the combined free and forced convection from a long heated square obstacle confined in a horizontal channel are investigated in this work. The numerical computations are performed in the steady regime for Reynolds number = 1 - 30, Richardson number = 0 - 1 for blockage ratios of 0.125 and 0.25 for the fixed Prandtl number of 0.7 (air. The governing equations, along with appropriate boundary conditions, are solved by using a semi-explicit finite volume method implemented on the collocated grid arrangement. The total drag and lift coefficients, local and average Nusselt numbers and the representative streamline, vorticity and isotherm patterns are presented to elucidate the role of blockage ratio on the cross-buoyancy across a confined square cylinder. The asymmetry in the flow and temperature fields decreases with increasing value of the blockage ratio. Similar to forced convection, the total drag coefficient increases with increasing value of the blockage ratio for the fixed values of the Reynolds and Richardson numbers.

  8. Domain Walls Zoo in Supersymmetric QCD

    OpenAIRE

    Smilga, A. V.; Veselov, A. I.

    1997-01-01

    Solving numerically the equations of motion for the effective lagrangian describing supersymmetric QCD with the SU(2) gauge group, we find a menagerie of complex domain wall solutions connecting different chirally asymmetric vacua. Some of these solutions are BPS saturated walls; they exist when the mass of the matter fields does not exceed some critical value m < m* < 4.67059... There are also sphaleron branches (saddle points of the ebergy functional). In the range m* < m < m** \\approx 4.83...

  9. Writing Beyond the Wall: Translation, Cross-cultural Exchange, and Chen Ran's 'A Private Life'

    Directory of Open Access Journals (Sweden)

    Kay Schaffer

    2006-09-01

    Full Text Available The past decade has witnessed an unprecedented rise in the global flow of knowledge, nowhere more apparent in the exchange of ideas between China and modern western democracies. Our interest concerns one aspect of this global flow— the translation of Chinese women’s autobiographical writing into English. Taking Chen Ran’s A Private Life (English edition, 2004 as a point of departure, the paper explores issues of translingual practice and cross-cultural exchange. It considers what escapes or is lost in translation as well as the additive potential of the host text. It is sometimes the case that the translation can deliberately make certain ambiguities visible—whether from pragmatic, market-driven motivations or from more complex political, historical and cultural considerations. These negotiations of meaning that occur in the translation process can reverberate on the critical reception of texts in both the ‘guest’ and ‘host’ languages (Liu 1995, with open-ended, incomplete and indeterminate effects. The paper examines the effects of the omission of a brief parenthetical section of three paragraphs from one chapter of the Chinese edition of A Private Life. Yet, even that small emendation changes the original text as a cultural object and alters potential modes of its reception. In this case, the translation results in a loss of ambiguity, irony, philosophic and rhetorical sophistication while also offering additive potentials that enhance the generation of new meanings in the translingual exchange, here with reference Tiananmen and contemporary feminism in China. The translation process provides new channels for readers, writers and theorists to dialogue and communicate across gaps of difference, despite inhibiting factors like the imposition of local restraints, the universalising pressures of western modernity, and asymmetrical relations of power between guest and host language contexts.

  10. The spacetime life of a non-BPS D-particle

    International Nuclear Information System (INIS)

    We investigate the classical geometry generated by a stable non-BPS D-particle. We consider the boundary state of a stable non-BPS D-particle in the covariant formalism in the type IIB theory orbifolded by (-1)FL·I4. We calculate the scattering amplitude between two D-particles in the non-compact and compact orbifold and analyse the short and long distance behaviour. At short distances we find no force at order υ2 for any radius, and at the critical radius we find a BPS-like behaviour up to υ4 corrections for long and short distances. Projecting the boundary state on the massless states of the orbifold closed string spectrum we obtain the large distance behaviour of the classical solution describing this non-BPS D-particle in the non-compact and compact cases. By using the non-BPS D-particle as a probe of the background geometry of another non-BPS D-particle, we recover the no-force condition at the critical radius and the υ2 behaviour of the probe. Moreover, assuming that the no-force persists for the complete geometry we derive part of the classical solution for the non-BPS D-particle. (author)

  11. Novel BPS Wilson loops in three-dimensional quiver Chern–Simons-matter theories

    Directory of Open Access Journals (Sweden)

    Hao Ouyang

    2016-02-01

    Full Text Available We show that generic three-dimensional N=2 quiver super Chern–Simons-matter theories admit Bogomol'nyi–Prasad–Sommerfield (BPS Drukker–Trancanelli (DT type Wilson loops. We investigate both Wilson loops along timelike infinite straight lines in Minkowski spacetime and circular Wilson loops in Euclidean space. In Aharnoy–Bergman–Jafferis–Maldacena theory, we find that generic BPS DT type Wilson loops preserve the same number of supersymmetries as Gaiotto–Yin type Wilson loops. There are several free parameters for generic BPS DT type Wilson loops in the construction, and supersymmetry enhancement for Wilson loops happens for special values of the parameters.

  12. Clustering and decomposition for non BPS solutions of the $\\mathbb{CP}^{N-1}$ models

    OpenAIRE

    Bolognesi, S.; Zakrzewski, W.

    2013-01-01

    We look at solutions [both Bogomol’nyi-Prasad-Sommerfield (BPS) and non-BPS] of the CPN−1 model on R×S1 (with twisted boundary conditions), in particular by using a conformal mapping technique, and we show how to interpret these solutions by decomposing them into expressions describing constituent solitons. We point out the problems that may arise (for non-BPS solutions) when one naively looks at the clustering properties of these solutions. This could lead to misunderstandings when studying ...

  13. Clustering and decomposition for non BPS solutions of the $\\mathbb{CP}^{N-1}$ models

    CERN Document Server

    Bolognesi, S

    2013-01-01

    We look at solutions (both BPS and non-BPS) of the $\\mathbb{CP}^{N-1}$ model on $\\mathbb{R} \\times S^1$ (with twisted boundary conditions), in particular by using a conformal mapping technique, and we show how to interpret these solutions by decomposing them into expressions describing constituent solitons. We point out the problems that may arise (for non-BPS solutions) when one naively looks at the clustering properties of these solutions. This could lead to misunderstandings when studying extrapolations between small and large compactification radii.

  14. Clustering and decomposition for non-BPS solutions of the CPN -1 models

    Science.gov (United States)

    Bolognesi, S.; Zakrzewski, W.

    2014-03-01

    We look at solutions [both Bogomol'nyi-Prasad-Sommerfield (BPS) and non-BPS] of the CPN -1 model on R×S1 (with twisted boundary conditions), in particular by using a conformal mapping technique, and we show how to interpret these solutions by decomposing them into expressions describing constituent solitons. We point out the problems that may arise (for non-BPS solutions) when one naively looks at the clustering properties of these solutions. This could lead to misunderstandings when studying extrapolations between small and large compactification radii.

  15. Effect of activation cross-section uncertainties on the radiological assessment of the MFE/DEMO first wall

    Energy Technology Data Exchange (ETDEWEB)

    Cabellos, O. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, Madrid (Spain)]. E-mail: cabellos@din.upm.es; Reyes, S. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Sanz, J. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, Madrid (Spain); University Nacional Educacion a Distancia, Dep. Ingenieria Energetica, Juan del Rosal 12, 28040 Madrid (Spain); Rodriguez, A. [University Nacional Educacion a Distancia, Dep. Ingenieria Energetica, Juan del Rosal 12, 28040 Madrid (Spain); Youssef, M. [University of California, Los Angeles, CA (United States); Sawan, M. [University of Wisconsin, Madison, WI (United States)

    2006-02-15

    A Monte Carlo procedure has been applied in this work in order to address the impact of activation cross-sections (XS) uncertainties on contact dose rate and decay heat calculations for the outboard first wall (FW) of a magnetic fusion energy (MFE) demonstration (DEMO) reactor. The XSs inducing the major uncertainty in the prediction of activation related quantities have been identified. Results have shown that for times corresponding to maintenance activities the uncertainties effect is insignificant since the dominant XSs involved in these calculations are based on accurate experimental data evaluations. However, for times corresponding to waste management/recycling activities, the errors induced by the XSs uncertainties, which in this case are evaluated using systematic models, must be considered. It has been found that two particular isotopes, {sup 6}Co and {sup 94}Nb, are key contributors to the global DEMO FW activation uncertainty results. In these cases, the benefit from further improvements in the accuracy of the critical reaction XSs is discussed.

  16. The 1/2 BPS Wilson loop in ABJM theory at two loops

    OpenAIRE

    Bianchi, Marco S.; Giribet, Gaston; Leoni, Matias; Penati, Silvia

    2013-01-01

    We compute the expectation value of the 1/2 BPS circular Wilson loop in ABJM theory at two loops in perturbation theory. The result shows perfect agreement with the prediction from localization and the proposed framing factor.

  17. Vortex-type half-BPS solitons in Aharony-Bergman-Jafferis-Maldacena theory

    International Nuclear Information System (INIS)

    We study the Aharony-Bergman-Jafferis-Maldacena (ABJM) theory without and with mass deformation. It is shown that maximally supersymmetry preserving, D-term, and F-term mass deformations of single mass parameter are equivalent. We obtain vortex-type half-BPS equations and the corresponding energy bound. For the undeformed ABJM theory, the resulting half-BPS equation is the same as that in supersymmetric Yang-Mills theory and no finite energy regular BPS solution is found. For the mass-deformed ABJM theory, the half-BPS equations for U(2)xU(2) case reduce to the vortex equation in Maxwell-Higgs theory, which supports static regular multivortex solutions. In U(N)xU(N) case with N>2 the non-Abelian vortex equation of Yang-Mills-Higgs theory is obtained.

  18. The Spacetime Life of a non-BPS D-particle

    CERN Document Server

    Eyras, E; Eyras, Eduardo; Panda, Sudhakar

    2000-01-01

    We investigate the classical geometry generated by a stable non-BPSD-particle. We consider the boundary state of a stable non-BPS D-particle inthe covariant formalism in the type IIB theory orbifolded by (-1)^{F_L} I_4.Projecting the boundary state on the massless states of the orbifold closedstring spectrum we obtain the large distance behaviour of the classicalsolution describing this non-BPS D-particle in the non-compact and compactcases. By using the non-BPS D-particle as a probe of the background geometry ofanother non-BPS D-particle, we recover the no-force condition at the criticalradius. Moreover, considering that the no-force persists at any distance fromthe source we derive part of the full classical solution for the non-BPSD-particle.

  19. BPS Force Balances via Spin-Spin Interactions

    CERN Document Server

    Kastor, D A; Kastor, David; Traschen, Jennie

    1999-01-01

    We study two systems of BPS solitons in which spin-spin interactions are important in establishing the force balances which allow static, multi-soliton solutions to exist. Solitons in the Israel-Wilson-Perjes (IWP) spacetimes each carry arbitrary, classical angular momenta. Solitons in the Aichelburg-Embacher "superpartner" spacetimes carry quantum mechanical spin, which originates in the zero-modes of the gravitino field of N=2 supergravity in an extreme Reissner-Nordstrom background. In each case we find a cancellation between gravitational spin-spin and magnetic dipole-dipole forces, in addition to the usual one between Newtonian gravitational attraction and Coulombic electrostatic repulsion. In both cases, we analyze the forces between two solitons by treating one of the solitons as a probe or test particle, with the appropriate properties, moving in the background of the other. In the IWP case, the equation of motion for a spinning test particle, originally due to Papapetrou, includes a coupling between ...

  20. BPS operators from the Wilson loop in the 3-dimensional supersymmetric Chern-Simons theory

    OpenAIRE

    Fujita, Mitsutoshi

    2009-01-01

    We consider the small deformation of the pointlike Wilson loop in the 3-dimensional N=6 superconformal Chern-Simons theory. By Taylor expansion of the pointlike Wilson loop in powers of the loop variables, we obtain the BPS operators that correspond to the excited string states of the dual IIA string theory on the pp wave background. The BPS conditions of the Wilson loop constrain both the loop variables and the forms of the operators obtained in the Taylor expansion.

  1. Remarks on the mixed Ramond–Ramond, open string scattering amplitudes of BPS, non-BPS and brane–anti-brane

    Energy Technology Data Exchange (ETDEWEB)

    Hatefi, Ehsan, E-mail: ehsanhatefi@gmail.com [Centre for Research in String Theory, School of Physics and Astronomy, Queen Mary University of London, Mile End Road, E1 4NS, London (United Kingdom); National Institute for Theoretical Physics, School of Physics, Mandelstam Institute for Theoretical Physics, University of the Witwatersrand, Wits, 2050, Johannesburg (South Africa); Institute des Hautes Etudes Scientifiques, 91440, Bures-sur-Yvette (France)

    2015-10-31

    From the world-sheet point of view we compute three, four and five point BPS and non-BPS scattering amplitudes of type IIA and IIB superstring theory. All these mixed S-matrix elements including a Ramond–Ramond closed string (RR) in the bulk and a scalar/gauge or tachyons with all different pictures (including an RR in asymmetric and symmetric pictures) have been carried out. We have also shown that in asymmetric pictures various equations must be kept fixed. More importantly, by direct calculations on the upper half plane, it is realised that some of the equations (which must be true) for BPS branes cannot be necessarily applied to non-BPS amplitudes. We also derive the S-matrix elements of 〈V{sub C}{sup -2}V{sub ϕ}{sup 0}V{sub A}{sup 0}V{sub T}{sup 0}〉 and clarify the fact that in the presence of the scalar field and an RR, the terms carrying momentum of an RR in the transverse directions play an important role in the entire form of the S-matrix and their presence is needed in order to have gauge invariance for the entire S-matrix elements of type IIA (IIB) superstring theory.

  2. Remarks on the mixed Ramond-Ramond, open string scattering amplitudes of BPS, non-BPS and brane-anti-brane

    Energy Technology Data Exchange (ETDEWEB)

    Hatefi, Ehsan [Queen Mary University of London, Centre for Research in String Theory, School of Physics and Astronomy, London (United Kingdom); University of the Witwatersrand, Wits, National Institute for Theoretical Physics, School of Physics, Mandelstam Institute for Theoretical Physics, Johannesburg (South Africa); Institute des Hautes Etudes Scientifiques, Bures-sur-Yvette (France)

    2015-11-15

    From the world-sheet point of view we compute three, four and five point BPS and non-BPS scattering amplitudes of type IIA and IIB superstring theory. All these mixed S-matrix elements including a Ramond-Ramond closed string (RR) in the bulk and a scalar/gauge or tachyons with all different pictures (including an RR in asymmetric and symmetric pictures) have been carried out. We have also shown that in asymmetric pictures various equations must be kept fixed. More importantly, by direct calculations on the upper half plane, it is realised that some of the equations (which must be true) for BPS branes cannot be necessarily applied to non-BPS amplitudes. We also derive the S-matrix elements of left angle V{sub C}{sup -2}V{sub φ}{sup 0}V{sub A}{sup 0}V{sub T}{sup 0} right angle and clarify the fact that in the presence of the scalar field and an RR, the terms carrying momentum of an RR in the transverse directions play an important role in the entire form of the S-matrix and their presence is needed in order to have gauge invariance for the entire S-matrix elements of type IIA (IIB) superstring theory. (orig.)

  3. Effective action of domain wall networks

    International Nuclear Information System (INIS)

    U(NC) gauge theory with NF fundamental scalars admits BPS junctions of domain walls. When the networks/webs of these walls contain loops, their size moduli give localized massless modes. We construct Kaehler potential of their effective action. In the large size limit Kaehler metric is well approximated by kinetic energy of walls and junctions, which is understood in terms of tropical geometry. Kaehler potential can be expressed in terms of hypergeometric functions that are useful to understand small size behavior. Even when the loop shrinks, the metric is regular with positive curvature. Moduli space of a single triangle loop has a geometry between a cone and a cigar

  4. Expression of group B protective surface protein (BPS) by invasive and colonizing isolates of group B streptococci.

    Science.gov (United States)

    Flores, Aurea E; Chhatwal, G S; Hillier, Sharon L; Baker, Carol J; Ferrieri, Patricia

    2014-12-01

    Group B protective surface protein (BPS) is expressed on the cell surface of some group B streptococcal (GBS) (Streptococcus agalactiae) strains and adds to the identification by capsular polysaccharide (CPS), and c or R proteins. We investigated the prevalence of BPS among GBS clinical isolates (303 invasive, 4122 colonizing) collected over 11 years in four American cities. Hot HCl cell extracts were tested by immunoprecipitation in agarose with rabbit antisera to BPS; the alpha (α) and beta (β) components of c protein; R1, R3, and R4 species of R protein; and CPS serotypes Ia-VIII. BPS was found in 155 isolates (seven invasive, 148 colonizing). Of these, 87 were Ia, 37 II, 20 V; none were III. BPS was expressed usually with another protein: a species of R by 87 or a component of c by 39. The predominant CPS/protein profiles with BPS were Ia/R1,BPS and II/c(α + β),BPS. Thus, along with CPS serotype and other surface proteins, BPS can be a valuable marker for precise strain characterization of unique GBS clinical isolates with complex surface protein profiles. PMID:25108378

  5. Long-Distance Signaling in bypass1 Mutants:Bioassay Development Reveals the bps Signal to Be a Metabolite

    Institute of Scientific and Technical Information of China (English)

    Emma Adhikari; Dong-Keun Lee; Patrick Giavalisco; Leslie E. Sieburth

    2013-01-01

    Root-to-shoot signaling is used by plants to coordinate shoot development with the conditions experienced by the roots.A mobile and biologically active compound,the bps signal,is over-produced in roots of an Arabidopsis thaliana mutant called bypass1 (bps1),and might also be a normally produced signaling molecule in wild-type plants.Our goal is to identify the bps signal chemically,which will then allow us to assess its production in normal plants.To identify any signaling molecule,a bioassay is required,and here we describe the development of a robust,simple,and quantitative bioassay for the bps signal.The developed bioassay follows the growth-reducing activity of the bps signal using the pCYCB1;1::GUS cell cycle marker.Wild-type plants carrying this marker,and provided the bps signal through either grafts or metabolite extracts,showed reduced cell division.By contrast,control grafts and treatment with control extracts showed no change in pCYCB1;1::GUS expression.To determine the chemical nature of the bps signal,extracts were treated with RNase A,Proteinase K,or heat.None of these treatments diminished the activity of bps1 extracts,suggesting that the active molecule might be a metabolite.This bioassay will be useful for future biochemical fractionation and analysis directed toward bps signal identification.

  6. Evolution and functional diversity of the Calcium Binding Proteins (CaBPs

    Directory of Open Access Journals (Sweden)

    Lee P Haynes

    2012-02-01

    Full Text Available The mammalian central nervous system (CNS exhibits a remarkable ability to process, store and transfer information. Key to these activities is the use of highly regulated and unique patterns of calcium signals encoded by calcium channels and decoded by families of specific calcium-sensing proteins. The largest family of eukaryotic calcium sensors are those related to the small EF-hand containing protein calmodulin (CaM. In order to maximise the usefulness of calcium as a signalling species and to permit the evolution and fine tuning of the mammalian CNS, families of related proteins have arisen that exhibit characteristic calcium binding properties and tissue-, cellular- and sub-cellular distribution profiles. The Calcium Binding Proteins (CaBPs represent one such family of vertebrate specific calmodulin like proteins that have emerged in recent years as important regulators of essential neuronal target proteins. Bioinformatic analyses indicate that the CaBPs consist of two subfamilies and that the ancestral members of these are CaBP1 and CaBP8. The CaBPs have distinct intracellular localisations based on different targeting mechanisms including a novel type-II transmembrane domain in CaBPs 7 and 8. Recent work has led to the identification of new target interactions and possible functions for the CaBPs suggesting that they have multiple physiological roles with relevance for the normal functioning of the CNS.

  7. On correlation functions of BPS operators in $3d$ $\\mathcal{N}=6$ superconformal theories

    CERN Document Server

    Liendo, Pedro; Mitev, Vladimir

    2015-01-01

    We introduce a novel harmonic superspace for $3d$ $\\mathcal{N}=6$ superconformal field theories that is tailor made for the study of correlation functions of BPS operators. We calculate a host of two- and three-point functions in full generality and put strong constraints on the form of four-point functions of some selected BPS multiplets. For the four-point function of $\\frac{1}{2}$-BPS operators we obtain the associated Ward identities by imposing the absence of harmonic singularities. The latter imply the existence of a solvable subsector in which the correlator becomes topological. This mechanism can be explained by cohomological reduction with respect to a special nilpotent supercharge.

  8. 6d → 5d → 4d reduction of BPS attractors in flat gauged supergravities

    Directory of Open Access Journals (Sweden)

    Kiril Hristov

    2015-08-01

    This is achieved starting from the BPS black string in 6d with an AdS3×S3 attractor and taking two different routes to arrive at a 1/2 BPS AdS2×S2 attractor of a non-BPS black hole in 4d N=2 flat gauged supergravity. The two inequivalent routes interchange the order of KK reduction on AdS3 and SS reduction on S3. We also find the commutator between the two operations after performing a duality transformation: on the level of the theory the result is the exchange of electric with magnetic gaugings; on the level of the solution we find a flip of the quartic invariant I4 to −I4.

  9. A Tale of Two Spaces: BPS Wilson Loops in Minkowski Spacetime and Euclidean Space

    CERN Document Server

    Ouyang, Hao; Zhang, Jia-ju

    2015-01-01

    We discuss BPS Wilson loops of $d=4$ $\\mathcal N=4$ super Yang-Mills theory, $d=3$ $\\mathcal N=2$ super Chern-Simons-matter theory, and $d=3$ $\\mathcal N=6$ Aharony-Bergman-Jafferis-Maldacena theory, in both Minkowski spacetime and Euclidean space. We find that there are timelike and null BPS Wilson loops in Minkowski spacetime, but spacelike BPS Wilson loops do not exist. We attribute this to the conflicts of reality conditions of spinors. However, in Euclidean space spacelike Wilson loops do exist. There are both Wilson lines of infinite straight lines and Wilson loops of circles. This is because the reality conditions of spinors are lost after Wick rotation. The result is reasonable in view of AdS/CFT correspondence.

  10. Construction of novel BPS Wilson loops in three-dimensional quiver Chern-Simons-matter theories

    CERN Document Server

    Ouyang, Hao; Zhang, Jia-ju

    2015-01-01

    In this paper, we construct novel Drukker-Trancanelli (DT) type BPS Wilson loops along infinite straight lines in $\\mathcal N=2,3$ quiver super Chern-Simons-matter (CSM) theories, Aharony-Bergman-Jafferis-Maldacena (ABJM) theory, and $\\mathcal N=4$ orbifold ABJM theory. There are several free complex parameters in the DT type BPS Wilson loops, and for Wilson loops in ABJM theory and $\\mathcal N=4$ orbifold ABJM theory there are supersymmetry enhancements at special values of the parameters. We check that the differences of the DT type and Gaiotto-Yin (GY) type Wilson loops are $Q$-exact with $Q$ being some supercharges preserved by both the DT type and GY type Wilson loops. The results would be useful to calculate vacuum expectation values of the Wilson loops in matrix models if they are still BPS quantum mechanically.

  11. Split attractor flows and the spectrum of BPS D-branes on the Quintic

    CERN Document Server

    Denef, F; Raugas, M V; Denef, Frederik; Greene, Brian; Raugas, Mark

    2001-01-01

    We investigate the spectrum of type IIA BPS D-branes on the quintic from a four dimensional supergravity perspective and the associated split attractor flow picture. We obtain some very concrete properties of the (quantum corrected) spectrum, mainly based on an extensive numerical analysis, and to a lesser extent on exact results in the large radius approximation. We predict the presence and absence of some charges in the BPS spectrum in various regions of moduli space, including the precise location of the lines of marginal stability and the corresponding decay products. We explain how the generic appearance of multiple basins of attraction is due to the presence of conifold singularities and give some specific examples of this phenomenon. Some interesting space-time features of these states are also uncovered, such as a nontrivial, moduli independent lower bound on the area of the core of arbitrary BPS solutions, whether they are black holes, empty holes, or more complicated composites.

  12. Three-Charge Black Holes and Quarter BPS States in Little String Theory

    CERN Document Server

    Giveon, Amit; Kutasov, David; Lee, Sungjay

    2015-01-01

    We show that the system of $k$ NS5-branes wrapping $\\mathbb{T}^4\\times S^1$ has non-trivial vacuum structure. Different vacua have different spectra of 1/4 BPS states that carry momentum and winding around the $S^1$. In one vacuum, such states are described by black holes; in another, they can be thought of as perturbative BPS states in Double Scaled Little String Theory. In general, both kinds of states are present. We compute the degeneracy of perturbative BPS states exactly, and show that it differs from that of the corresponding black holes. We comment on the implication of our results to the black hole microstate program, UV/IR mixing in Little String Theory, string thermodynamics, the string/black hole transition, and other issues.

  13. Split attractor flows and the spectrum of BPS D-branes on the Quintic

    International Nuclear Information System (INIS)

    We investigate the spectrum of type IIA BPS D-branes on the quintic from a four dimensional supergravity perspective and the associated split attractor flow picture. We obtain some very concrete properties of the (quantum corrected) spectrum, mainly based on an extensive numerical analysis, and to a lesser extent on exact results in the large radius approximation. We predict the presence and absence of some charges in the BPS spectrum in various regions of moduli space, including the precise location of the lines of marginal stability and the corresponding decay products. We explain how the generic appearance of multiple basins of attraction is due to the presence of conifold singularities and give some specific examples of this phenomenon. Some interesting space-time features of these states are also uncovered, such as a nontrivial, moduli independent lower bound on the area of the core of arbitrary BPS solutions, whether they are black holes, empty holes, or more complicated composites. (author)

  14. Monopole dynamics and BPS dyons in N=2 super-Yang-Mills theories

    International Nuclear Information System (INIS)

    We determine the low-energy dynamics of monopoles in pure N=2 Yang-Mills theories for points in the vacuum moduli space where the two Higgs fields are not aligned. The dynamics is governed by a supersymmetric quantum mechanics with potential terms and four real supercharges. The corresponding superalgebra contains a central charge but nevertheless supersymmetric states preserve all four supercharges. The central charge depends on the sign of the electric charges and consequently so does the BPS spectrum. We focus on the SU(3) case where certain BPS states are realized as zero modes of a Dirac operator on Taub-NUT space twisted by the triholomorphic Killing vector field. We show that the BPS spectrum includes hypermultiplets that are consistent with the strong- and weak-coupling behavior of Seiberg-Witten theory. (c) 2000 The American Physical Society

  15. New Massive Gravity Domain Walls

    CERN Document Server

    dS, U Camara

    2010-01-01

    The properties of the asymptotic $AdS_3$ space-times representing flat domain walls (DW's) solutions of the New Massive 3D Gravity with scalar matter are studied. Our analysis is based on $I^{st}$ order BPS-like equations involving an appropriate superpotential. The Brown-York boundary stress-tensor is used for the calculation of DW's tensions as well as of the $CFT_2$'s central charges. The holographic renormalization group flows and the phase transitions in specific deformed $CFT_2$ dual to 3D massive gravity model with quadratic superpotential are discussed.

  16. Bubbling 1/4 BPS solutions in type IIB and supergravity reductions on SnxSn

    International Nuclear Information System (INIS)

    We extend the construction of bubbling 1/2 BPS solutions of Lin, Lunin and Maldacena (H. Lin, O. Lunin, J. Maldacena, JHEP 0410 (2004) 025, hep-th/0409174) in two directions. First we enquire whether bubbling 1/2 BPS solutions can be constructed in minimal 6d supergravity and second we construct solutions that are 1/4 BPS in type IIB. We find that the S1xS1 bosonic reduction of (1,0) 6d supergravity to 4d gravity coupled to 2 scalars and a gauge field is consistent only provided that the gauge field obeys a constraint (F-bar F=0). This is to be contrasted to the case of the S3xS3 bosonic reduction of type IIB supergravity to 4d gravity, 2 scalars and a gauge field, where consistency is achieved without imposing any such constraints. Therefore, in the case of (1,0) 6d supergravity we are able to construct 1/2 BPS solutions, similar to those derived in type IIB, provided that this additional constraint is satisfied. This ultimately prohibits the construction of a family of 1/2 BPS solutions corresponding to a bubbling AdS3xS3 geometry. Returning to type IIB solutions, by turning on an axion-dilaton field we construct a family of bubbling 1/4 BPS solutions. This corresponds to the inclusion of back-reacted D7 branes to the solutions of Lin, Lunin and Maldacena

  17. BPS operators from the Wilson loop in the 3-dimensional supersymmetric Chern-Simons theory

    OpenAIRE

    Fujita, Mitsutoshi

    2009-01-01

    We consider the small deformation of the point-like Wilson loop in the 3-dimensional $\\mathcal{N}=6$ superconformal Chern-Simons theory. By Taylor expansion of the point-like Wilson loop in powers of the loop variables, we obtain the BPS operators that correspond to the excited string states of the dual IIA string theory on the pp wave background. The BPS conditions of the Wilson loop constrain both the loop variables and the forms of the operators obtained in the Taylor expansion.

  18. BPS Wilson loops and Bremsstrahlung function in ABJ(M): a two loop analysis

    OpenAIRE

    Bianchi, M; Griguolo, L.; de Leoni, M. (Massimiliano); Penati, S; Seminara, D.

    2014-01-01

    We study a family of circular BPS Wilson loops in $ \\mathcal{N} $ = 6 super Chern-Simons-matter theories, generalizing the usual 1/2-BPS circle. The scalar and fermionic couplings depend on two deformation parameters and these operators can be considered as the ABJ(M) counterpart of the DGRT latitudes defined in $ \\mathcal{N} $ = 4 SYM. We perform a complete two-loop analysis of their vacuum expectation value, discuss the appearance of framing-like phases and propose a general relation with c...

  19. Rotational-vibrational coupling in the BPS Skyrme model of baryons

    CERN Document Server

    Adam, C; Sanchez-Guillen, J; Wereszczynski, A

    2013-01-01

    We calculate the rotational-vibrational spectrum in the BPS Skyrme model for the hedgehog skyrmion with baryon number one. The resulting excitation energies for the nucleon and delta Roper resonances are slightly above their experimental values. Together with the fact that in the standard Skyrme model these excitation energies are significantly lower than the experimental ones, this provides strong evidence for the conjecture that the inclusion of the BPS Skyrme model is necessary for a successful quantitative description of physical properties of baryons and nuclei.

  20. Rotational-vibrational coupling in the BPS Skyrme model of baryons

    Energy Technology Data Exchange (ETDEWEB)

    Adam, C.; Naya, C.; Sanchez-Guillen, J. [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Reymonta 4, Kraków (Poland)

    2013-11-04

    We calculate the rotational-vibrational spectrum in the BPS Skyrme model for the hedgehog skyrmion with baryon number one. The resulting excitation energies for the nucleon and delta Roper resonances are slightly above their experimental values. Together with the fact that in the standard Skyrme model these excitation energies are significantly lower than the experimental ones, this provides strong evidence for the conjecture that the inclusion of the BPS Skyrme model is required for a successful quantitative description of physical properties of baryons and nuclei.

  1. BPS Equations in Omega-deformed N=4 Super Yang-Mills Theory

    CERN Document Server

    Ito, Katsushi; Nakajima, Hiroaki; Sasaki, Shin

    2015-01-01

    We study supersymmetry of N=4 super Yang-Mills theory in four dimensions deformed in the Omega-background. We take the Nekrasov-Shatashvili limit of the background so that two-dimensional super Poincare symmetry is recovered. We compute the deformed central charge of the superalgebra and study the 1/2 and 1/4 BPS states. We obtain the Omega-deformed 1/2 and 1/4 BPS dyon equations from the deformed supersymmetry transformation and the Bogomol'nyi completion of the energy.

  2. On Toda equation and half BPS supergravity solution in M-theory

    International Nuclear Information System (INIS)

    Recently, it was shown that half BPS Supergravity solution of theories with SU(2/4) symmetry algebra is given uniformly by determining a single function which obeys three dimensional continuous Toda equation. In this paper, we study the scale invariant solution of Toda equation. Our motivation is that some solutions of half BPS sector of IIB supergravity, as one excepts from the fermion description of the theory, are scale invariant. By defining two auxiliary functions we prove that such solutions of Toda equation obey cubic algebraic equation. We obtain some simpl solutions of Toda equation specially, we observe that the PP-wave solution can be written in this fashion

  3. Non-BPS interactions from the type II one loop four graviton amplitude

    Science.gov (United States)

    Basu, Anirban

    2016-06-01

    We obtain T-duality invariant second order differential equations satisfied by the {D}8{{ R }}4 and {D}10{{ R }}4 interactions from the low energy expansion of the one loop four graviton amplitude in toroidally compactified type II string theory. The eigenvalues of these equations are completely determined by the structure of the one loop integrands. Unlike the BPS interactions, these non-BPS interactions satisfy Poisson equations having source terms that receive contributions from both the bulk and boundary of the worldsheet moduli space. We explicitly solve these equations in nine-dimensions.

  4. Baryon chemical potential and in-medium properties of BPS skyrmions

    CERN Document Server

    Adam, C; Naya, C; Sanchez-Guillen, J; Vazquez, R; Wereszczynski, A

    2015-01-01

    We continue the investigation of thermodynamical properties of the BPS Skyrme model. In particular, we analytically compute the baryon chemical potential both in the full field theory and in a mean-field approximation. In the full field theory case, we find that the baryon chemical potential is always exactly proportional to the baryon density, for arbitrary solutions. We further find that, in the mean-field approximation, the BPS Skyrme model approaches the Walecka model in the limit of high density - their thermodynamical functions as well as the equation of state agree in this limit. This fact allows to read off some properties of the $\\omega$-meson from the BPS Skyrme action, even though the latter model is entirely based on the (pionic) $SU(2)$ Skyrme field. On the other hand, at low densities, at the order of the usual nuclear matter density, the equations of state of the two models are no longer universal, such that a comparison depends on some model details. Still, also the BPS Skyrme model gives rise...

  5. y-Deformed BPS Dp-branes On a Surface In a Calabi-Yau Threefold

    CERN Document Server

    Ospina, J F

    2000-01-01

    Using y-deformed algebraic geometric techniques the y-deformed Mukay vector of RR-charges of the y-deformed BPS Dp-branes localized on a surface in a Calabi-Yau threefold. The formulas that are obtained here are generalizations of the formulas of the fourth section of the preprint hep-th/0007243 .

  6. Cosmic D- and DF-strings from D3Dbar3: Black Strings and BPS Bound

    CERN Document Server

    Kim, T; Kyae, B; Lee, J; Kim, Taekyung; Kim, Yoonbai; Kyae, Bumseok; Lee, Jungjai

    2006-01-01

    We study D- and DF-strings from D3${\\bar {\\rm D}}3$ in the context of Dirac-Born-Infeld type effective field theory. In the presence of an electric flux from a transverse direction, gravitating thick D-string solutions form a spatial manifold, ${\\rm S}^{2}\\times {\\rm R}^{1}$, and straight D-strings stretched along the R${}^{1}$ direction are located at the south and north poles of the two-sphere. There is a horizon along its equator and then the structure of black strings is supported. We also discuss systematic derivation of the BPS bounds for thin parallel D- and DF-strings in both flat and curved spacetime. The BPS sum rule is obtained for arbitrarily-separated multi-string configuration under a Gaussian type tachyon potential and, at the site of each thin BPS D(F)-string, the pressure does not vanish but is finite. For the conical geometry induced by thin BPS D- and DF-strings, we find that there exists maximum deficit angle $\\pi$.

  7. Reflections on Online Learning Designs and Cross-Institutional Research Collaborations: Revisiting "Classrooms without Walls" in Two Australian Universities

    Science.gov (United States)

    Rossi, Dolene; van Rensburg, Henriette; Clark, Damien; Harreveld, R. E.; Beer, Colin; Danaher, P. A.

    2015-01-01

    The article on which this paper reflects ["Exploring a Cross-Institutional Research Collaboration and Innovation: Deploying Social Software and Web 2.0 Technologies to Investigate Online Learning Designs and Interactions in Two Australian Universities"] presented elements of a research project investigating learning interactions in…

  8. α'-exact entropies for BPS and non-BPS extremal dyonic black holes in heterotic string theory from ten-dimensional supersymmetry

    Science.gov (United States)

    Dominis Prester, Predrag; Terzić, Tomislav

    2008-12-01

    We calculate near-horizon solutions for four-dimensional 4-charge and five-dimensional 3-charge black holes in heterotic string theory from the part of the ten-dimensional tree-level effective action which is connected to gravitational Chern-Simons term by supersymmetry. We obtain that the entropies of large black holes exactly match the α'-exact statistical entropies obtained from microstate counting (D = 4) and AdS/CFT correspondence (D = 5). Especially interesting is that we obtain agreement for both BPS and non-BPS black holes, contrary to the case of R2-truncated (four-derivative) actions (D-dimensional Script N = 2 off-shell supersymmetric or Gauss-Bonnet) were used, which give the entropies agreeing (at best) just for BPS black holes. The key property of the solutions, which enabled us to tackle the action containing infinite number of terms, is vanishing of the Riemann tensor bar RMNPQ obtained from torsional connection defined with barGamma = Γ-½H. Moreover, if every monomial of the remaining part of the effective action would contain at least two Riemanns bar RMNPQ, it would trivially follow that our solutions are exact solutions of the full heterotic effective action in D = 10. The above conjecture, which appeared (in this or stronger form) from time to time in the literature, has controversial status, but is supported by the most recent calculations of Richards (arXiv:0807.3453 [hep-th]). Agreement of our results for the entropies with the microscopic ones supports the conjecture. As for small black holes, our solutions in D = 5 still have singular horizons.

  9. Solvent-free covalent functionalization of multi-walled carbon nanotubes and nanodiamond with diamines: Looking for cross-linking effects

    International Nuclear Information System (INIS)

    Highlights: ► Diamines were used for one-step functionalization of nanotubes and nanodiamond. ► We found experimental evidences of cross-linking effects in these nanomaterials. ► We found a strong orientation effect in the functionalized carbon nanotubes. - Abstract: The covalent functionalization of carbon nanomaterials with diamines is a way to enhance the mechanical strength of nanocomposites due to cross-linking effects, to form complex networks for nanotube-based electronic circuits, as well as is important for a number of biomedical applications. The main goal of the present work was to covalently functionalize pristine multi-walled carbon nanotubes and nanodiamond with three aliphatic diamines (1,8-diaminooctane, 1,10-diaminodecane and 1,12-diaminododecane) and one aromatic diamine (1,5-diaminonaphthalene), by employing a simple one-step solvent-free methodology, which is based on thermal instead of chemical activation. We looked for experimental evidences of cross-linking effects in the carbon nanomaterials synthesized by using solubility/dispersibility tests, atomic force microscopy, scanning and transmission electron microscopy, as well as Fourier-transform infrared spectroscopy and thermogravimetric analysis for additional characterization.

  10. The Resistance Calculation of the Thin-Walled Cold-Formed Compressed Steel Members with Closed Cross-sections. Part 2

    Directory of Open Access Journals (Sweden)

    Mohamad Al Ali

    2014-02-01

    Full Text Available Part 1 of the paper presents fundamental information about the experimental and theoretical research oriented to determine the resistance of thin-walled cold-formed compressed steel members with closed cross-sections, [1]. The investigated members were made from homogeneous material. The theoretical analysis was oriented to determine the resistance of mentioned members according to European and Slovak standards, while the experimental investigation was to verify the theoretical results and to investigate the behavior of the above-mentioned members during the loading process, [2]. Part 2 is focused on the numerical analysis of the achieved results, as well as on 3D modeling and simulation of the experimental tests.

  11. The Hodge-elliptic genus, spinning BPS states, and black holes

    CERN Document Server

    Kachru, Shamit

    2016-01-01

    We perform a refined count of BPS states in the compactification of M-theory on $K3 \\times T^2$, keeping track of the information provided by both the $SU(2)_L$ and $SU(2)_R$ angular momenta in the $SO(4)$ little group. Mathematically, this four variable counting function may be expressed via the motivic Donaldson-Thomas counts of $K3 \\times T^2$, simultaneously refining Katz, Klemm, and Pandharipande's motivic Donaldson-Thomas counts on $K3$ and Oberdieck-Pandharipande's Gromov-Witten counts on $K3 \\times T^2$. This provides the first full answer for motivic curve counts of a compact Calabi-Yau threefold. Along the way, we develop a Hodge-elliptic genus for Calabi-Yau manifolds -- a new counting function for BPS states that interpolates between the Hodge polynomial and the elliptic genus of a Calabi-Yau.

  12. BPS-saturated string amplitudes: K3 elliptic genus and Igusa cusp form χ10

    International Nuclear Information System (INIS)

    We study BPS-saturated one-loop amplitudes in type II string theory compactified on K3×T2. The classes of amplitudes we consider are only sensitive to the very basic topological data of the internal K3 manifold. As a consequence, the integrands of the former are related to the elliptic genus of K3, which can be decomposed into representations of the internal N=4 superconformal algebra. Depending on the precise choice of external states these amplitudes capture either only the contribution of the short multiplets or the full series including intermediate multiplets. In the latter case we can define a generating functional for the whole class, which we show is given by the weight ten Igusa cusp form χ10 of Sp(4,Z). We speculate on possible algebraic implications of our result on the BPS states of the N=4 type II compactification.

  13. Phase transitions and statistical mechanics for BPS Black Holes in AdS/CFT

    International Nuclear Information System (INIS)

    Using the general framework developed in hep-th/0607056, we study in detail the phase space of BPS Black Holes in AdS, for the case where all three electric charges are equal. Although these solitons are supersymmetric with zero Hawking temperature, it turns out that these Black Holes have rich phase structure with sharp phase transitions associated to a corresponding critical generalized temperature. We are able to rewrite the gravity variables in terms of dual CFT variables and compare the gravity phase diagram with the free dual CFT phase diagram. In particular, the elusive supergravity constraint characteristic of these Black Holes is particularly simple and in fact appears naturally in the dual CFT in the definition of the BPS Index. Armed with this constraint, we find perfect match between BH and free CFT charges up to expected constant factors

  14. AdS3 Holography for 1/4 and 1/8 BPS geometries

    CERN Document Server

    Giusto, Stefano; Russo, Rodolfo

    2015-01-01

    Recently a new class of 1/8-BPS regular geometries in type IIB string theory was constructed in arXiv:1502.01254. In this paper we provide a precise description of the semiclassical states dual, in the AdS/CFT sense, to these geometries. In explicit examples we show that the holographic 1-point functions and the Ryu-Takayanagi's Entanglement Entropy for a single small interval match the corresponding CFT calculations performed by using the proposed dual states. We also discuss several new examples of such precision holography analysis in the 1/4-BPS sector and provide an explicit proof that the small interval derivation of the Entanglement Entropy used in arXiv:1405.6185 is fully covariant.

  15. BPS M5-branes as Defects for the 3d-3d Correspondence

    CERN Document Server

    Bah, Ibrahima; Halmagyi, Nick

    2014-01-01

    We study supersymmetric probe M5-branes in the AdS_4 solution that arises from M5-branes wrapped on a hyperbolic 3-manifold M_3. This amounts to introducing internal defects within the framework of the 3d-3d correspondence. The BPS condition for a probe M5-brane extending along all of AdS_4 requires it to wrap a surface embedded in an S^2-fibration over M_3. We find that the projection of this surface to M_3 can be either a geodesic or a tubular surface around a geodesic. These configurations preserve an extra U(1) symmetry, in addition to the one corresponding to the R-symmetry of the dual 3d N=2 gauge theory. BPS M2-branes can stretch between M5-branes wrapping geodesics. We interpret the addition of probe M5-branes on a closed geodesic in terms of conformal Dehn surgery.

  16. Instanton Corrections of 1/6 BPS Wilson Loops in ABJM Theory

    OpenAIRE

    Okuyama, Kazumi

    2016-01-01

    We study instanton corrections to the vacuum expectation value (VEV) of 1/6 BPS Wilson loops in ABJM theory from the Fermi gas approach. We mainly consider Wilson loops in the fundamental representation and winding Wilson loops, but we also initiate the study of Wilson loops with two boundaries. We find that the membrane instanton corrections to the Wilson loop VEV are determined by the refined topological string in the Nekrasov-Shatashvili limit, and the pole cancellation mechanism between m...

  17. Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors

    CERN Document Server

    Alonso-Izquierdo, Alberto; Guilarte, Juan Mateos

    2016-01-01

    In this paper the zero modes of fluctuation of cylindrically symmetric self-dual vortices are analyzed and described in full detail. These BPS topological defects arise at the critical point between Type II and Type I superconductors, or, equivalently, when the masses of the Higgs particle and the vector boson in the Abelian Higgs model are equal. In addition, novel bound states of Higss and vector bosons trapped by the self-dual vortices at their core are found and investigated.

  18. Non-BPS Solutions of the Noncommutative CP^1 Model in 2+1 Dimensions

    OpenAIRE

    Furuta, Ko; Inami, Takeo(Mathematical Physics Lab., Riken Nishina Center, Saitama 351-0198, Japan); Nakajima, Hiroaki; Yamamoto, Masayoshi

    2002-01-01

    We find non-BPS solutions of the noncommutative CP^1 model in 2+1 dimensions. These solutions correspond to soliton anti-soliton configurations. We show that the one-soliton one-anti-soliton solution is unstable when the distance between the soliton and the anti-soliton is small. We also construct time-dependent solutions and other types of solutions.

  19. Transcript profiling of two alfalfa genotypes with contrasting cell wall composition in stems using a cross-species platform: optimizing analysis by masking biased probes

    Directory of Open Access Journals (Sweden)

    Jung Hans-Joachim G

    2010-05-01

    Full Text Available Abstract Background The GeneChip® Medicago Genome Array, developed for Medicago truncatula, is a suitable platform for transcript profiling in tetraploid alfalfa [Medicago sativa (L. subsp. sativa]. However, previous research involving cross-species hybridization (CSH has shown that sequence variation between two species can bias transcript profiling by decreasing sensitivity (number of expressed genes detected and the accuracy of measuring fold-differences in gene expression. Results Transcript profiling using the Medicago GeneChip® was conducted with elongating stem (ES and post-elongation stem (PES internodes from alfalfa genotypes 252 and 1283 that differ in stem cell wall concentrations of cellulose and lignin. A protocol was developed that masked probes targeting inter-species variable (ISV regions of alfalfa transcripts. A probe signal intensity threshold was selected that optimized both sensitivity and accuracy. After masking for both ISV regions and previously identified single-feature polymorphisms (SFPs, the number of differentially expressed genes between the two genotypes in both ES and PES internodes was approximately 2-fold greater than the number detected prior to masking. Regulatory genes, including transcription factor and receptor kinase genes that may play a role in development of secondary xylem, were significantly over-represented among genes up-regulated in 252 PES internodes compared to 1283 PES internodes. Several cell wall-related genes were also up-regulated in genotype 252 PES internodes. Real-time quantitative RT-PCR of differentially expressed regulatory and cell wall-related genes demonstrated increased sensitivity and accuracy after masking for both ISV regions and SFPs. Over 1,000 genes that were differentially expressed in ES and PES internodes of genotypes 252 and 1283 were mapped onto putative orthologous loci on M. truncatula chromosomes. Clustering simulation analysis of the differentially expressed genes

  20. Non-BPS exact solutions and their relation to bions in ${\\mathbb C}P^{N-1}$ models

    CERN Document Server

    Misumi, Tatsuhiro; Sakai, Norisuke

    2016-01-01

    We investigate non-BPS exact solutions in ${\\mathbb C}P^{N-1}$ sigma models on ${\\mathbb R}^1 \\times S^{1}$ with twisted boundary conditions, by using the Din-Zakrzewski projection method. We focus on the relation of the non-BPS solutions to the ansatz of multi-instanton (bion) configurations and discuss their significance in the context of the resurgence theory. We find that the transition between seemingly distinct configurations of multi-instantons occur as moduli changes in the non-BPS solutions, and the simplest non-BPS exact solution corresponds to multi-bion configurations with fully-compressed double fractional instantons in the middle. It indicates that the non-BPS solutions make small but nonzero contribution to the resurgent trans-series as special cases of the multi-bion configurations. We observe a generic pattern of transitions between distinct multi-bion configurations (flipping partners), leading to the three essential properties of the non-BPS exact solution: (i) opposite sign for terms corre...

  1. Calculating corrections in F-theory from refined BPS invariants and backreacted geometries

    International Nuclear Information System (INIS)

    This thesis presents various corrections to F-theory compactifications which rely on the computation of refined Bogomol'nyi-Prasad-Sommerfield (BPS) invariants and the analysis of backreacted geometries. Detailed information about rigid supersymmetric theories in five dimensions is contained in an index counting refined BPS invariants. These BPS states fall into representations of SU(2)L x SU(2)R, the little group in five dimensions, which has an induced action on the cohomology of the moduli space of stable pairs. In the first part of this thesis, we present the computation of refined BPS state multiplicities associated to M-theory compactifications on local Calabi-Yau manifolds whose base is given by a del Pezzo or half K3 surface. For geometries with a toric realization we use an algorithm which is based on the Weierstrass normal form of the mirror geometry. In addition we use the refined holomorphic anomaly equation and the gap condition at the conifold locus in the moduli space in order to perform the direct integration and to fix the holomorphic ambiguity. In a second approach, we use the refined Goettsche formula and the refined modular anomaly equation that govern the (refined) genus expansion of the free energy of the half K3 surface. By this procedure, we compute the refined BPS invariants of the half K3 from which the results of the remaining del Pezzo surfaces are obtained by flop transitions and blow-downs. These calculations also make use of the high symmetry of the del Pezzo surfaces whose homology lattice contains the root lattice of exceptional Lie algebras. In cases where both approaches are applicable, we successfully check the compatibility of these two methods. In the second part of this thesis, we apply the results obtained from the calculation of the refined invariants of the del Pezzo respectively the half K3 surfaces to count non-perturbative objects in F-theory. The first application is given by BPS states of the E-String which are

  2. Calculating corrections in F-theory from refined BPS invariants and backreacted geometries

    Energy Technology Data Exchange (ETDEWEB)

    Poretschkin, Maximilian

    2015-07-01

    This thesis presents various corrections to F-theory compactifications which rely on the computation of refined Bogomol'nyi-Prasad-Sommerfield (BPS) invariants and the analysis of backreacted geometries. Detailed information about rigid supersymmetric theories in five dimensions is contained in an index counting refined BPS invariants. These BPS states fall into representations of SU(2){sub L} x SU(2){sub R}, the little group in five dimensions, which has an induced action on the cohomology of the moduli space of stable pairs. In the first part of this thesis, we present the computation of refined BPS state multiplicities associated to M-theory compactifications on local Calabi-Yau manifolds whose base is given by a del Pezzo or half K3 surface. For geometries with a toric realization we use an algorithm which is based on the Weierstrass normal form of the mirror geometry. In addition we use the refined holomorphic anomaly equation and the gap condition at the conifold locus in the moduli space in order to perform the direct integration and to fix the holomorphic ambiguity. In a second approach, we use the refined Goettsche formula and the refined modular anomaly equation that govern the (refined) genus expansion of the free energy of the half K3 surface. By this procedure, we compute the refined BPS invariants of the half K3 from which the results of the remaining del Pezzo surfaces are obtained by flop transitions and blow-downs. These calculations also make use of the high symmetry of the del Pezzo surfaces whose homology lattice contains the root lattice of exceptional Lie algebras. In cases where both approaches are applicable, we successfully check the compatibility of these two methods. In the second part of this thesis, we apply the results obtained from the calculation of the refined invariants of the del Pezzo respectively the half K3 surfaces to count non-perturbative objects in F-theory. The first application is given by BPS states of the E

  3. SUSY QM from three domain walls in a scalar potential

    International Nuclear Information System (INIS)

    We investigate the linear classical stability of Bogomol'nyi-Prasad-Sommerfield (BPS) on three domain wall solutions in a system of three coupled real scalar fields, for a general positive potential with a square form. From a field theoretic superpotential evaluated on the domain states, the connection between the supersymmetric quantum mechanics involving three-component eigenfunctions and the stability equation associated with three classical configurations is elaborated. (author)

  4. Profiling and comparison of color body wall transcriptome of normal juvenile sea cucumber ( Apostichopus japonicus) and those produced by crossing albino

    Science.gov (United States)

    Ma, Deyou; Yang, Hongsheng; Sun, Lina

    2014-12-01

    Sea cucumber ( Apostichopus japonicus) is one of the most important aquaculture animals in China. Usually its normal body color is black that fits its living environment. The juvenile individuals obtained by crossing albino sea cucumber segregated in body color. To document the transcriptome difference between albino associating sea cucumber and the control, we sequenced their transcriptomes with RNA-seq. Approximately, 4.790 million (M) and 4.884 M reads, 200 nt in length, were generated from the body wall of albino associating sea cucumber and the control, respectively, from them, 9550 (46.81%) putative genes were identified. In total, 583 genes were found to express differentially between albino associating sea cucumber and the control. Of these differentially expressed genes (DEGs), 4.8% changed more than five-folds. The expression levels of eight DEGs were confirmed with real-time PCR. The changing trend of these DEGs detected with real-time PCR agreed well with that detected with RNA-seq, although the change degree of some DEGs was different. Four significantly enriched pathways were identified for DEGs, which included phagocytosis, Staphylococcus aureus infection, ECM-receptor interaction and focal adhesion. These pathways were helpful for understanding the physiological difference between albino associating sea cucumber and the control.

  5. Effective Action of Domain Wall Networks

    CERN Document Server

    Eto, M; Nagashima, T; Nitta, M; Ohashi, K; Sakai, N; Eto, Minoru; Fujimori, Toshiaki; Nagashima, Takayuki; Nitta, Muneto; Ohashi, Keisuke; Sakai, Norisuke

    2007-01-01

    U(Nc) gauge theory with Nf fundamental scalars admits BPS junctions of domain walls. When the networks/webs of these walls contain loops, their size moduli give localized massless modes. We construct K\\"ahler potential of their effective action. In the large size limit K\\"ahler metric is well approximated by kinetic energy of walls and junctions, which is understood in terms of tropical geometry. K\\"ahler potential can be expressed in terms of hypergeometric functions which are useful to understand small size behavior. Even when the loop shrinks, the metric is regular with positive curvature. Moduli space of a single triangle loop has a geometry between a cone and a cigar.

  6. Developing a dynamic website using WordPress CMS for BPS Finland Oy

    OpenAIRE

    K.C., Kiran

    2014-01-01

    This Bachelor’s thesis aims to develop a website for a small-to-medium-sized enterprise (SME), BPS Finland Oy, which is fully based on the customer’s requirements. In this thesis project, a completely new dynamic website was developed from the design layout provided by the case company in a Photoshop version. WordPress, a Content Management System (CMS), was used to create a dynamic website. CMS is a software programme to power, manage and modify the website’s contents and avoid the need ...

  7. Instanton Corrections of 1/6 BPS Wilson Loops in ABJM Theory

    CERN Document Server

    Okuyama, Kazumi

    2016-01-01

    We study instanton corrections to the vacuum expectation value (VEV) of 1/6 BPS Wilson loops in ABJM theory from the Fermi gas approach. We mainly consider Wilson loops in the fundamental representation and winding Wilson loops, but we also initiate the study of Wilson loops with two boundaries. We find that the membrane instanton corrections to the Wilson loop VEV are determined by the refined topological string in the Nekrasov-Shatashvili limit, and the pole cancellation mechanism between membrane instantons and worldsheet instantons works also in the Wilson loop VEVs as in the case of the partition functions.

  8. Diagonal Form Factors and Hexagon Form Factors II. Non-BPS Light Operator

    CERN Document Server

    Jiang, Yunfeng

    2016-01-01

    We study the asymptotic volume dependence of the heavy-heavy-light three-point functions in the $\\mathcal{N}=4$ Super-Yang-Mills theory using the hexagon bootstrap approach, where the volume is the length of the heavy operator. We extend the analysis of our previous short letter 1511.06199 to the general case where the heavy operators can be in any rank one sector and the light operator being a generic non-BPS operator. We prove the conjecture of Bajnok, Janik and Wereszczynski 1404.4556 up to leading finite size corrections.

  9. Self-intersection number of BPS junctions in backgrounds of three and seven-branes

    International Nuclear Information System (INIS)

    In a recent paper DeWolfe et al. have shown how to use the self-intersection number of junctions to constrain the BPS spectrum of N=2, D=4 theories with ADE flavor symmetry arising on a single D3-brane probe in a 7-brane background. Motivated by the existence of more general N=2, D=4 theories arising on the worldvolume of multiple D3-brane probes we show how to compute the self-intersection number of junctions in the presence of 7-branes and multiple D3-branes. (author)

  10. Half BPS states in AdS_5 x Y^{p,q}

    OpenAIRE

    Gava, Edi; Narain, Kumar S.; Milanesi, Giuseppe; O'Loughlin, Martin

    2007-01-01

    We study a class of solutions of IIB Supergravity which are asymptotically AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS_5 x S^5 background. These geometries correspond to certain chiral primary operators of the N=1 superco...

  11. Collisions of domain walls in a supersymmetric model

    International Nuclear Information System (INIS)

    A collision of two parallel domain walls in a supersymmetric model is analyzed by using both the effective-Lagrangian approximation and a numerical solution to the equations of motion for the scalar components of the superfields involved. Two cases - that where a configuration belonging to the type of two parallel walls is saturated in the sense of Bogomol'nyi, Prasad, and Sommerfeld (BPS) and that where such a configuration is not BPS-saturated - are considered individually. For the first case, it is shown that, at low initial velocities, a collision of the walls is virtually an elastic reflection somewhat delayed in time. It is also demonstrated that, in this case, it is possible to introduce a collective variable that has the meaning of an internal parameter of the configuration and which can be treated as a dynamical (time-dependent) variable and to describe the dynamics of the system in terms of an effective Lagrangian. For the second case, it is found that, for collisions, there is a critical value of vcr ≅ 0.9120 for the initial velocity vi. For vi cr, the reflection of the walls occurs, the vacuum between the walls remaining unchanged. For vi > vcr, the collision process is accompanied by a change in the vacuum state between the walls

  12. Near-BPS-saturated rotating electrically charged black holes as string states

    International Nuclear Information System (INIS)

    We construct generating solutions for general D-dimensional (4≤D≤9) rotating, electrically charged, black holes in the effective action of toroidally compactified heterotic (or Type IIA) string. The generating solution is parameterized by the ADM mass, two electric charges and [(D-1)/2] angular momenta (as well as the asymptotic values of one toroidal modulus and the dilaton field). For D≥6, those are generating solutions for general black holes in toroidally compactified heterotic (or type IIA) string. Since in the BPS-limit (extreme limit) these solutions have singular horizons or naked singularities, we address the near extreme solutions with all the angular momenta small enough. In this limit, the thermodynamic entropy can be cast in a suggestive form, which has a qualitative interpretation as microscopic entropy of (near)-BPS-saturated charged string states of toroidally compactified heterotic string, whose target-space angular momenta are identified as [(D-1)/2] U(1) left-moving world-sheet currents. (orig.)

  13. Transcript Profiling of Two Alfalfa Genotypes with Contrasting Cell Wall Composition in Stems Using a Cross-Species Platform: Optimizing Analysis by Masking Biased Probes

    Science.gov (United States)

    The stem cell walls of alfalfa [Medicago sativa (L.) ssp. sativa] genotype 252 have high cellulose and lignin concentrations, while stem cell walls of genotype 1283 have low cellulose and lignin concentrations. The GeneChip® Medicago Genome Array, developed for Medicago truncatula, is a suitable pla...

  14. Binding of nitrogen-containing bisphosphonates (N-BPs) to the Trypanosoma cruzi farnesyl diphosphate synthase homodimer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan-Hsiang; Gabelli, Sandra B.; Oldfield, Eric; Amzel, L. Mario (UIUC); (JHU-MED)

    2010-11-15

    Bisphosphonates (BPs) are a class of compounds that have been used extensively in the treatment of osteoporosis and malignancy-related hypercalcemia. Some of these compounds act through inhibition of farnesyl diphosphate synthase (FPPS), a key enzyme in the synthesis of isoprenoids. Recently, nitrogen-containing bisphosphonates (N-BPs) used in bone resorption therapy have been shown to be active against Trypanosoma cruzi, the parasite that causes American trypanosomiasis (Chagas disease), suggesting that they may be used as anti-trypanosomal agents. The crystal structures of TcFPPS in complex with substrate (isopentenyl diphosphate, IPP) and five N-BP inhibitors show that the C-1 hydroxyl and the nitrogen-containing groups of the inhibitors alter the binding of IPP and the conformation of two TcFPPS residues, Tyr94 and Gln167. Isothermal titration calorimetry experiments suggest that binding of the first N-BPs to the homodimeric TcFPPS changes the binding properties of the second site. This mechanism of binding of N-BPs to TcFPPS is different to that reported for the binding of the same compounds to human FPPS.

  15. BPS Explained II: Calculating the Equilibration Rate in the Extreme Quantum Limit

    CERN Document Server

    Singleton, Robert L

    2007-01-01

    This is the second in a series of two lectures on the technique of dimensional continuation, a new method for analytically calculating certain energy transport quantities in a weakly to moderately coupled plasma. Recently, this method was employed by Brown, Preston, and Singleton (BPS) to calculate the electron-ion temperature equilibration rate and the charged particle stopping power to leading and next-to-leading order in the plasma coupling. In this lecture, I develop the framework further, and then explicitly calculate the electron-ion temperature equilibration rate in the high temperature limit. This method captures all short and long distance physics to second order in the plasma coupling. This analytic perturbative technique is applicable for ignition in inertial confinement fusion and for other processes in hot a weakly coupled plasma.

  16. BPS Zk strings, string tensions and confinement in non-Abelian theories

    International Nuclear Information System (INIS)

    In this talk we review some generalizations of 't Hooft and Mandelstam ideas on confinement for theories with non-Abelian unbroken gauge groups. In order to do that, we consider N=2 super Yang-Mills with one flavor and a mass breaking term. One of the spontaneous symmetry breaking is accomplished by a scalar that can be in particular in the representation of the diquark condensate. We analyze the phases of the theory. In the superconducting phase, we show the existence of BPS Zk-strings and calculate exactly their string tension in a straightforward way. We also find that magnetic fluxes of the monopole and Zk-strings are proportional to one another allowing for monopole confinement in a phase transition. We further show that some of the resulting confining theories can be obtained by adding a deformation term N 2 or N = 4 superconformal theories. (author)

  17. On super form factors of half-BPS operators in N=4 super Yang-Mills

    International Nuclear Information System (INIS)

    We compute form factors of half-BPS operators in N=4 super Yang-Mills dual to massive Kaluza-Klein modes in supergravity. These are appropriate supersymmetrisations Tk of the scalar operators Tr (ϕk) for any k, which for k = 2 give the chiral part of the stress-tensor multiplet operator. Using harmonic superspace, we derive simple Ward identities for these form factors, which we then compute perturbatively at tree level and one loop. We propose a novel on-shell recursion relation which links form factors with different numbers of fields. Using this, we conjecture a general formula for the n-point MHV form factors of Tk for arbitrary k and n. Finally, we use supersymmetric generalised unitarity to derive compact expressions for all one-loop MHV form factors of Tk in terms of one-loop triangles and finite two-mass easy box functions

  18. Algebraicity and Asymptotics: An explosion of BPS indices from algebraic generating series

    CERN Document Server

    Mainiero, Tom

    2016-01-01

    It is an observation of Kontsevich and Soibelman that generating series that produce certain (generalized) Donaldson Thomas invariants are secretly algebraic functions over the rationals. From a physical perspective this observation arises naturally for DT invariants that appear as BPS indices in theories of class S[A]: explicit algebraic equations (that completely determine these series) can be derived using (degenerate) spectral networks. In this paper, we conjecture an algebraic equation associated to DT invariants for the Kronecker 3-quiver with dimension vectors (3n,2n), n>0 in the non-trivial region of its stability parameter space. Using a functional equation due to Reineke, we show algebraicity of generating series for Euler characteristics of stable moduli for the Kronecker m-quiver assuming algebraicity of generating series for DT invariants. In the latter part of the paper we deduce very explicit results on the asymptotics of DT invariants/Euler characteristics under the assumption of algebraicity ...

  19. Cell Wall

    OpenAIRE

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Albenne, Cécile; Pont-Lezica, Rafael F

    2008-01-01

    This chapter covers our present knowledge of cell wall proteomics highlighting the distinctive features of cell walls and cell wall proteins in relation to problems encountered for protein extraction, separation and identification. It provides clues to design strategies for efficient cell wall proteomic studies. It gives an overview of the kinds of proteins that have yet been identified: the expected proteins vs the identified proteins. Finally, the new vision of the cell wall proteome, and t...

  20. 转基因大豆BPS-CV127-9 PCR定量检测研究%Quantitative Detection of Genetically Modified Soybean BPS-CV127-9

    Institute of Scientific and Technical Information of China (English)

    李宁; 赵蕾; 孙红炜; 李凡; 杨淑珂; 路兴波

    2012-01-01

    A quantitative method to detect the transgenic soybean BPS-CV-127-9 by using real-time PCR technique based on fluorescence dye SYBR Green I was investigated in this study. The endogenous lectin gene and the 5' flanking sequences of BPS-CV-127-9 were amplified through the specific primers,and the transgenic content was then calculated according to the standard curve equation. Meanwhile the specificity of PCR amplification was analyzed by corresponding melting curves. The results showed that the standard curves of lectin and the 5' flanking sequences of BPS-CV-127-9 genes have good linear relationship, and their R values were 0. 999 and 0. 998, respectively. The coefficient of variance was 1. 50%-18. 51% and standard deviation was 0.02-0.07. Four mixed samples with genetically modified contents of BPS-CV-127-9 was 0.05% ,0.1% ,0.5% and 1% respectively were detected,and the detection results agreed well with actual value. In conclusion,this method was fast, sensitive, simple, accurate, specific and of high throughput, and could be used to detect transgenic soybean BPS-CV-127-9 quantificationally.%采用SYBR Green实时荧光定量PCR技术,建立转基因大豆BPS-CV127-9的定量检测方法.通过设计特异引物,扩增内标准基因lectin和BPS-CV127-9的5’侧翼序列,建立2种基因的拷贝数-CT标准曲线,根据标准曲线方程计算样品中的转基因含量,并且通过熔解曲线分析扩增反应特异性.结果表明,lectin基因和侧翼序列标准曲线线性关系良好,R2值分别为0.999和0.998,变异系数(CV) 1.50%~18.51%、标准偏差(SD)0.02 ~0.07.检测4个已知BPS-CV127-9含量(1%、0.5%、0.1%、0.05%)的转基因混合样品,实测值与实际值接近.该检测方法具有快速、灵敏、准确、特异、高通量等优点,可以作为转基因大豆BPS-CV127-9的定量检测方法.

  1. More on BPS States in N = 4 $$ \\mathcal{N}=4 $$ Supersymmetric Yang-Mills Theory on R × S 3

    OpenAIRE

    Yokoyama, Shuichi

    2014-01-01

    We perform a systematic analysis on supersymmetric states in N = 4 $$ \\mathcal{N}=4 $$ supersymmetric Yang-Mills theory (SYM) on R × S 3 . We find a new set of 1/16 BPS equations and determine the precise configuration of the supersymmetric states by solving all 1/16 BPS equations when they are valued in Cartan subalgebra of a gauge group and the fermionic fields vanish. We also determine the number of supersymmetries preserved by the supersymmetric states varying the parameters of the BPS so...

  2. The quantum 1/2 BPS Wilson loop in ${\\cal N}=4$ Chern-Simons-matter theories

    CERN Document Server

    Bianchi, Marco S; Leoni, Matias; Mauri, Andrea; Penati, Silvia; Seminara, Domenico

    2016-01-01

    In three dimensional ${\\cal N}=4$ Chern-Simons-matter theories two independent fermionic Wilson loop operators can be defined, which preserve half of the supersymmetry charges and are cohomologically equivalent at classical level. We compute their three-loop expectation value in a convenient color sector and prove that the degeneracy is uplifted by quantum corrections. We expand the matrix model prediction in the same regime and by comparison we conclude that the quantum 1/2 BPS Wilson loop is the average of the two operators. We provide an all-loop argument to support this claim at any order. As a by-product, we identify the localization result at three loops as a correction to the framing factor induced by matter interactions. Finally, we comment on the quantum properties of the non-1/2 BPS Wilson loop operator defined as the difference of the two fermionic ones.

  3. Perturbative evaluation of circular 1/2 BPS Wilson loops in N = 6 Super Chern-Simons theories

    CERN Document Server

    Griguolo, Luca; Poggi, Matteo; Seminara, Domenico

    2013-01-01

    We present a complete two-loop analysis of the quantum expectation value for circular BPS Wilson loops in ABJ(M) theories. We examine in details the 1/2 BPS case, that requires non-trivial fermionic couplings with the contour, finding perfect agreement with the exact matrix model answer at zero framing. The result is obtained through a careful application of DRED regularization scheme, combined with a judicious rearrangement of the relevant perturbative contributions that reduces the computation to simple integrals. We carefully analyze the contribution of fermions that is crucial for the consistency with the localization procedure and point out the arising of pivotal evanescent terms, discussing their meaning in relation to Ward identities.

  4. Microscopic entropy of the most general BPS black hole for type II/M-theory on torii

    International Nuclear Information System (INIS)

    In the present dissertation we review the statistical computation of the entropy for the most general static BPS black hole solution in the framework of toroidally compactified type II/M-theory. This achievement is inscribed within a research project aimed to the study of the microscopic properties of this kind of solutions in relation to U-duality invariants (e.g. the entropy) computed on the corresponding macroscopic (supergravity) description. (orig.)

  5. N=2 SUGRA BPS Multi-center solutions, quadratic prepotentials and Freudenthal transformations

    CERN Document Server

    Fernandez-Melgarejo, J J

    2013-01-01

    We present a detailed description of N=2 stationary BPS multicenter black hole solutions for quadratic prepotentials with an arbitrary number of centers and scalar fields making a systematic use of the algebraic properties of the matrix of second derivatives of the prepotential, $\\mathcal{S}$, which in this case is a scalar-independent matrix. In particular we obtain bounds on the physical parameter of the multicenter solution such as horizon areas and ADM mass. We discuss the possibility and convenience of setting up a basis of the symplectic vector space built from charge eigenvectors of the $\\ssigma$, the set of vectors $(\\Ppm q_a)$ with $\\Ppm$ $\\ssigma$-eigenspace proyectors. The anti-involution matrix $\\mathcal{S}$ can be understood as a Freudenthal duality $\\tilde{x}=\\ssigma x$. We show that this duality can be generalized to "Freudenthal transformations" $$x\\to \\lambda\\exp(\\theta \\ssigma) x= a x+b\\tilde{x}$$ under which the horizon area, ADM mass and intercenter distances scale up leaving constant the ...

  6. N=2 SUGRA BPS multi-center black holes and freudenthal triple systems

    Directory of Open Access Journals (Sweden)

    Torrente-Lujan E.

    2015-01-01

    Full Text Available We present a detailed description of N = 2 stationary BPS multicenter black hole solutions for quadratic prepotentials with an arbitrary number of centers and scalar fields making a systematic use of the algebraic properties of the matrix of second derivatives of the prepotential, S, which in this case is a scalar-independent matrix. The anti-involution matrix S can be understood as a Freudenthal duality x̃ = Sx. We show that this duality can be generalized to “Freudenthal transformations” x→λexp(θSx=ax+bx˜$x \\to \\lambda \\exp \\left( {\\theta S} \\rightx = ax + b\\tilde x$ under which the horizon area, ADM mass and intercenter distances scale up leaving constant the scalars at the fixed points. In the special case λ = 1, “S-rotations”, the transformations leave invariant the solution. The standard Freudenthal duality can be written as x˜=exp (π2S x$\\tilde x = {\\rm{exp }}\\left( {{\\pi \\over 2}S} \\right{\\rm{ }}x$. We argue that these generalized transformations leave invariant not only the quadratic preotential theories but also the general stringy extremal quartic form Δ4, Δ4(x = Δ4(cos θx + sin θx̃ and therefore its entropy at lowest order.

  7. Topological charged BPS vortices in Lorentz-violating Maxwell-Higgs electrodynamics

    CERN Document Server

    Casana, R

    2014-01-01

    We have performed a complete study of BPS vortex solutions in the Abelian sector of the standard model extension (SME). Specifically we have coupled the SME electromagnetism with a Higgs field which is supplemented with a Lorentz-violating CPT-even term. We have verified that Lorentz-violation (LV) belonging to Higgs sector allows to interpolate between some well known models like, Maxwell-Higgs, Chern-Simons-Higgs and Maxwell-Chern-Simons-Higgs. We can also observed that the electrical charged density distribution is nonnull in both CPT-even and CPT-odd models, however the total electric charge in the CPT-even case is null whereas in the CPT-odd one it is proportional to the quantized magnetic flux. The following general results can be established in relation to the LV introduced in the Higgs sector: it changes the vortex \\emph{Ansatz} and the gauge field boundary conditions. The last one is responsible for the magnetic flux besides being proportional to the winding number also depends explicitly in the Lore...

  8. Half BPS states in AdS_5 x Y^{p,q}

    CERN Document Server

    Gava, Edi; Milanesi, Giuseppe; O'Loughlin, Martin

    2008-01-01

    We study a class of solutions of IIB Supergravity which are asymptotically AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS_5 x S^5 background. These geometries correspond to certain chiral primary operators of the N=1 superconformal quiver theories, dual to IIB theory on AdS_5 x Y^{p,q}. We also show how to recover the AdS_5 x Y^{p,q} backgrounds by suitably doubling the number of preserved supersymmetries. We then solve the differential equations perturbatively in a large AdS_5 radius expansion, imposing asymptotic AdS_5 x Y^{p,q} boundary conditions. We compute the global baryonic and mesonic charges, including the R-charge. As for the computation of the mass, i.e. the conformal dimension D of the dual field theory operators, which is notor...

  9. Half BPS states in AdS5 x Yp,q

    International Nuclear Information System (INIS)

    We study a class of solutions of IIB supergravity which are asymptotically AdS5 x Yp,q. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS5 x S5 background. These geometries correspond to certain chiral primary operators of the N = 1 superconformal quiver theories, dual to IIB theory on AdS5 x Yp,q. We also show how to recover the AdS5 x Yp,q backgrounds by suitably doubling the number of preserved supersymmetries. We then solve the differential equations perturbatively in a large AdS5 radius expansion, imposing asymptotic AdS5 x Yp,q boundary conditions. We compute the global baryonic and mesonic charges, including the R-charge. As for the computation of the mass, i.e. the conformal dimension Δ of the dual field theory operators, which is notoriously subtle in asymptotically AdS backgrounds, we adopt the general formalism due to Wald and collaborators, which gives a finite result, and verify the relation Δ = 3R/2, demanded by the N = 1 superconformal algebra

  10. Dimensional reduction of BPS attractors in AdS gauged supergravities

    CERN Document Server

    Hristov, Kiril

    2014-01-01

    We relate across dimensions BPS attractors of black strings and black holes of various topology in gauged supergravities with nontrivial scalar potential. The attractors are of the form AdS$_{2, 3} \\times \\Sigma^{2, 3}$ in 4, 5, and 6 dimensions, and can be generalized to some higher dimensional analogs. Even though the attractor geometries admit standard Kaluza-Klein and Scherk-Schwarz reductions, their asymptotic AdS spaces in general do not. The resulting lower dimensional objects are black holes with runaway asymptotics in supergravity theories with no maximally symmetric vacua. Such classes of solutions are already known to exist in literature, and results here suggest an interpretation in terms of their higher-dimensional origin that often has a full string theory embedding. In a particular relevant example, the relation between 5d Benini-Bobev black strings arXiv:1302.4451 and a class of 4d Cacciatori-Klemm black holes arXiv:0911.4926 is worked out in full detail, providing a type IIB and dual field th...

  11. 1/16-BPS Black Holes and Giant Gravitons in the AdS_5 X S^5 Space

    CERN Document Server

    Kim, S; Kim, Seok; Lee, Ki-Myeong

    2006-01-01

    We explore 1/16-BPS objects of type IIB string theory in AdS_5 * S^5. First, we consider supersymmetric AdS_5 black holes, which should be 1/16-BPS and have a characteristic that not all physical charges are independent. We point out that the Bekenstein-Hawking entropy of these black holes admits a remarkably simple expression in terms of (dependent) physical charges, which suggests its microscopic origin via certain Cardy or Hardy-Ramanujan formula. We also note that there is an upper bound for the angular momenta given by the electric charges. Second, we construct a class of 1/16-BPS giant graviton solutions in AdS_5 * S^5 and explore their properties. The solutions are given by the intersections of AdS_5 * S^5 and complex 3 dimensional holomorphic hyperspaces in C^{1+5}, the latter being the zero loci of three holomorphic functions which are homogeneous with suitable weights on coordinates. We investigate examples of giant gravitons, including their degenerations to tensionless strings.

  12. Cell wall monoglycine cross-bridges and methicillin hypersusceptibility in a femAB null mutant of methicillin-resistant Staphylococcus aureus.

    OpenAIRE

    Strandén, A M; Ehlert, K; Labischinski, H.; Berger-Bächi, B.

    1997-01-01

    The femAB operon is involved in the formation of the characteristic pentaglycine side chain of the staphylococcal peptidoglycan. Allele replacement of the femAB operon with the tetracycline resistance determinant tetK in a methicillin-resistant Staphylococcus aureus strain resulted in impaired growth, methicillin hypersusceptibility, and lysostaphin resistance. The usual pentaglycine cross-bridges were replaced by monoglycine bridges exclusively, and cross-linking of the peptidoglycan strands...

  13. Migration: Wall to Wall?

    Science.gov (United States)

    2015-10-01

    It is no news to anyone that health transcends national borders, driven by cross-border movement of vectors, populations, health professionals, climate, even policy trends. There is an increasing recognition that it is, in fact, a small world: we are affected by and affect what happens to our neighbors, whether they live around the corner or on the other side of the globe. This conception underpins the shift from the term international health to global health in policy discussions. The new terminology reflects change across several dimensions: from an approach in which there is one medicine for the developed world and another for developing countries, to an appreciation that we all have a stake in one another's wellbeing; from a primarily biomedical focus on treatment to a more multidisciplinary, population health focus taking into consideration a range of interventions to improve health and well-being, including the social and environmental determinants of health; and from a vertical bilateral-aid approach focused on specific diseases, to systems and ecological approaches addressing the complexities of health, involving multiple partnerships. PMID:26947274

  14. Domain Walls in Extended Lovelock Gravity

    CERN Document Server

    dS, U Camara; Lima, A L Alves; Sotkov, G M

    2012-01-01

    We derive a BPS-like first order system of equations for a family of flat static domain walls (DWs) of dimensionally extended cubic Lovelock Gravity coupled to massive scalar self-interacting matter. The explicit construction of such DWs is achieved by introducing of an appropriate matter superpotential. We further analyse the dependence of the geometric properties of the asymptotically AdSd space-times representing distinct DWs on the shape of the matter potential, on the values of the Lovelock couplings and on the scalar field boundary conditions. Few explicit examples of Lovelock DWs interpolating between AdS-type vacua of different cosmological constants are presented. In five dimensions our method provides interesting solutions of the Myers-Robinson Quasi-topological Gravity in the presence of matter important for the description of the specific renormalization group flows in its holographic dual four-dimensional CFT perturbed by relevant operators.

  15. Escherichia coli Protein Expression System for Acetylcholine Binding Proteins (AChBPs.

    Directory of Open Access Journals (Sweden)

    Nikita Abraham

    Full Text Available Nicotinic acetylcholine receptors (nAChR are ligand gated ion channels, identified as therapeutic targets for a range of human diseases. Drug design for nAChR related disorders is increasingly using structure-based approaches. Many of these structural insights for therapeutic lead development have been obtained from co-crystal structures of nAChR agonists and antagonists with the acetylcholine binding protein (AChBP. AChBP is a water soluble, structural and functional homolog of the extracellular, ligand-binding domain of nAChRs. Currently, AChBPs are recombinantly expressed in eukaryotic expression systems for structural and biophysical studies. Here, we report the establishment of an Escherichia coli (E. coli expression system that significantly reduces the cost and time of production compared to the existing expression systems. E. coli can efficiently express unglycosylated AChBP for crystallography and makes the expression of isotopically labelled forms feasible for NMR. We used a pHUE vector containing an N-terminal His-tagged ubiquitin fusion protein to facilitate AChBP expression in the soluble fractions, and thus avoid the need to recover protein from inclusion bodies. The purified protein yield obtained from the E. coli expression system is comparable to that obtained from existing AChBP expression systems. E. coli expressed AChBP bound nAChR agonists and antagonists with affinities matching those previously reported. Thus, the E. coli expression system significantly simplifies the expression and purification of functional AChBP for structural and biophysical studies.

  16. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how wall...

  17. Time evolution in superstring field theory on non-BPS brane 1. Rolling tachyon and energy-momentum conservation

    International Nuclear Information System (INIS)

    We derive equations of motion for the tachyon field living on an unstable non-BPS D-brane in the level truncated open cubic superstring field theory in the first non-trivial approximation. We construct a special time dependent solution to this equation which describes a rolling tachyon. It starts from the perturbative vacuum and approaches one of stable vacua in infinite time. We investigate conserved energy functional and show that its different parts dominate in different stages of the evolution. We show that the pressure for this solution has its minimum at zero time and goes to minus energy at infinite time. (author)

  18. Monitoring and control system of B-PS and S-PS fault interlock in the storage ring of SSRF

    International Nuclear Information System (INIS)

    In this paper, we report the local monitor and control system of fault interlock based on software design of S7-200 and S7-300 according to characteristics of the B-PS and S-PS in storage ring of SSRF. The remote monitor and control system based on EPICS are presented. The system architecture and key technologies in hardware and software designs are expatiated. Advantages of the system include the friendly interface and simple operation. The system has been working stably. (authors)

  19. All three-loop four-point correlators of half-BPS operators in planar N=4 SYM

    CERN Document Server

    Chicherin, Dmitry; Heslop, Paul; Sokatchev, Emery

    2015-01-01

    We obtain the planar correlation function of four half-BPS operators of arbitrary weights, up to three loops. Our method exploits only elementary properties of the integrand of the planar correlator, such as its symmetries and singularity structure. This allows us to write down a general ansatz for the integrand. The coefficients in the ansatz are fixed by means of a powerful light-cone OPE relation between correlators with different weights. Our result is formulated in terms of a limited number of functions built from known one-, two- and three-loop conformal integrals. These results are useful for checking recent integrability predictions for the OPE structure constants.

  20. Interactions of Domain Walls of SUSY Yang-Mills as D-Branes

    CERN Document Server

    Armoni, A; Armoni, Adi; Hollowood, Timothy J.

    2006-01-01

    Domain walls in supersymmetric Yang-Mills are BPS configurations which preserve two supercharges of the parent theory and so their tensions are known exactly. On the other hand, they have been described as D-branes for the confining string. This leads to a description of their collective dynamics in terms of a 2+1 -dimensional gauge theory with two supersymmetries and a Chern-Simons term. We show that this open string description can capture the qualitative behaviour of the forces between the domain walls for an arbitrary configuration of n walls at leading order in 1/N, extending earlier calculations for two walls. The potential admits a supersymmetric bound state when the n walls are all coincident and asymptotes to a constant at large separation with an n dependence which agrees perfectly with the exact tension formula.

  1. Interactions of domain walls of SUSY Yang-Mills as D-branes

    International Nuclear Information System (INIS)

    Domain walls in supersymmetric Yang-Mills are BPS configurations which preserve two supercharges of the parent theory and so their tensions are known exactly. On the other hand, they have been described as D-branes for the confining string. This leads to a description of their collective dynamics in terms of a 2+1-dimensional gauge theory with two supersymmetries and a Chern-Simons term. We show that this open string description can capture the qualitative behaviour of the forces between the domain walls for an arbitrary configuration of n walls at leading order in 1/N, extending earlier calculations for two walls. The potential admits a supersymmetric bound state when the n walls are all coincident and asymptotes to a constant at large separation with an n dependence which agrees perfectly with the exact tension formula

  2. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    International Nuclear Information System (INIS)

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 1028 m-3), density (maximally 1.16 g cm-3), and tear strength (11.2 kN m-1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  3. Experimental study of the turbulent flow around a single wall-mounted cube exposed to a cross-flow and an impinging jet

    International Nuclear Information System (INIS)

    Highlights: ► We measured the instantaneous flow velocity using 2D-Particle Image Velocimetry. ► Recirculation bubbles, vortices, detachment and reattachment zones are showed. ► The influence of the ReH and Rej/ReH was studied. ► The Rej/ReH determines the effects produced around the component. - Abstract: The air flow around a cubic obstacle mounted on one wall of a rectangular channel was studied experimentally. The obstacle represents an electronic component and the channel the space between two parallel printed circuit boards (PCBs). The flow was produced by the combination of a channel stream and a jet which issued from a circular nozzle placed at the wall opposite from where the component is mounted. With this aim, a test rig was designed and built to carry out experiments with both the above mentioned configurations and other cooling arrangements. Planar Particle Image Velocimetry (PIV) was employed to measure the instantaneous flow velocity on several planes covering the space around the component. The mean velocity and the Reynolds stresses were obtained from averaging the instantaneous velocity, and the mean flow showed a complex pattern with different features such as recirculation bubbles, vortices, detachment and reattachment zones. The influence of two parameters, namely the channel Reynolds number and the jet-to-channel Reynolds number ratio, on these flow features was studied considering nine cases that combined three values of the channel Reynolds number (3410, 5752 and 8880) and three values of the ratio (0.5, 1.0 and 1.5). The results show that the Reynolds number ratio determines the drag produced on the jet and the deflection from its geometric axis due to the channel stream. In all the cases corresponding to the lowest value of the ratio, the jet was dragged and did not impact the component. This fact accounts for the non-existence of the Upper Horseshoe Vortex and changes in the flow characteristics at the region over the component.

  4. Domain Walls and Flux Tubes in N=2 SQCD D-Brane Prototypes

    CERN Document Server

    Shifman, M

    2003-01-01

    This paper could have been entitled "D branes and strings from flesh and blood." We study field theoretic prototypes of D branes/strings. To this end we consider (2+1)-dimensional domain walls in (3+1)-dimensional N=2 SQCD with SU(2) gauge group and two quark flavors in the fundamental representation. This theory is perturbed by a small mass term of the adjoint matter which, in the leading order in the mass parameter, does not break N=2 supersymmetry, and reduces to a (generalized) Fayet-Iliopoulos term in the effective low-energy N=2 SQED. We find 1/2 BPS-saturated domain wall solution interpolating between two quark vacua at weak coupling, and show that this domain wall localizes a U(1) gauge field. To make contact with the brane/string picture we consider the Abrikosov-Nielsen-Olesen magnetic flux tube in one of two quark vacua and demonstrate that it can end on the domain wall. We find an explicit 1/4 BPS-saturated solution for the wall/flux tube junction. We verify that the end point of the flux tube on ...

  5. Superfluidity of Minkowskian Higgs vacuum with BPS monopoles quantized by Dirac may be described as Cauchy problem to Gribov ambiguity equation

    CERN Document Server

    Lantsman, L

    2006-01-01

    We show that manifest superfluid properties of the Minkowskian Higgs model with vacuum BPS monopoles quantized by Dirac may be described in the framework of the Cauchy problem to the Gribov ambiguity equation. The latter equation specifies the ambiguity in choosing the covariant Coulomb (transverse) gauge for Yang-Mills fields represented as topological Dirac variables, may be treated as solutions to the Gauss law constraint at the removal of temporal components of these fields. We demonstrate that the above Cauchy problem comes just to fixing the covariant Coulomb gauge for topological Dirac variables in the given initial time instant $t_0$ and finding the solutions to the Gribov ambiguity equation in the shape of vacuum BPS monopoles and excitations over the BPS monopole vacuum referring to the class of multipoles. The next goal of the present study will be specifying the look of Gribov topological multipliers entering Dirac variables in the Minkowskian Higgs model quantized by Dirac, especially at the spat...

  6. Precision calculation of 1/4-BPS Wilson loops in AdS$_5\\times S^5$

    CERN Document Server

    Forini, V; Griguolo, L; Seminara, D; Vescovi, E

    2015-01-01

    We study the strong coupling behaviour of $1/4$-BPS circular Wilson loops (a family of "latitudes") in ${\\cal N}=4$ Super Yang-Mills theory, computing the one-loop corrections to the relevant classical string solutions in AdS$_5\\times$S$^5$. Supersymmetric localization provides an exact result that, in the large 't Hooft coupling limit, should be reproduced by the sigma-model approach. To avoid ambiguities due to the absolute normalization of the string partition function, we compare the $ratio$ between the generic latitude and the maximal 1/2-BPS circle: Any measure-related ambiguity should simply cancel in this way. We use Gel'fand-Yaglom method to calculate the relevant functional determinants, that present some complications with respect to the standard circular case. After a careful numerical evaluation of our final expression we still find disagreement with the localization answer: The difference is encoded into a precise "remainder function". We comment on the possible origin and resolution of this dis...

  7. Precision calculation of 1/4-BPS Wilson loops in AdS5×S5

    Science.gov (United States)

    Forini, V.; Puletti, V. Giangreco M.; Griguolo, L.; Seminara, D.; Vescovi, E.

    2016-02-01

    We study the strong coupling behaviour of 1/4-BPS circular Wilson loops (a family of "latitudes") in {N}=4 Super Yang-Mills theory, computing the one-loop corrections to the relevant classical string solutions in AdS5 ×S5. Supersymmetric localization provides an exact result that, in the large 't Hooft coupling limit, should be reproduced by the sigma-model approach. To avoid ambiguities due to the absolute normalization of the string partition function, we compare the ratio between the generic latitude and the maximal 1/2-BPS circle: any measure-related ambiguity should simply cancel in this way. We use the Gel'fand-Yaglom method with Dirichlet boundary conditions to calculate the relevant functional determinants, that present some complications with respect to the standard circular case. After a careful numerical evaluation of our final expression we still find disagreement with the localization answer: the difference is encoded into a precise "remainder function". We comment on the possible origin and resolution of this discordance.

  8. Higgs phase in a gauge $\\mathbf{U}(1)$ non-linear $\\mathbf{CP}^1$-model. Two species of BPS vortices and their zero modes

    CERN Document Server

    Alonso-Izquierdo, Alberto

    2016-01-01

    In this paper zero modes of fluctuation are dissected around the two species of BPS vortices existing in the critical Higgs phase, where the scalar and vector meson masses are equal, of a gauged $\\mathbb{U}(1)$ nonlinear $\\mathbb{CP}^1$-model. If $2\\pi n$, $n\\in \\mathbb{Z}$, is the quantized magnetic flux of the two species of BPS vortex solutions, $2n$ linearly independent vortex zero modes for each species are found and described. The existence of two species of moduli spaces of dimension $2n$ of these stringy topological defects is thus locally shown.

  9. Endocrine Activity of Bisphenol S (BPS) Using In Vitro Estrogenic/Anti-Androgenic Transcriptional Activation Assays and the In Vivo Uterotrophic Assay

    Science.gov (United States)

    Bisphenol A (BPA) is gradually being phased out of many consumer products and processes leading to potential increases in human and environmental exposures to relatively understudied replacement compounds, including Bisphenol S (BPS). Research from our lab has shown that BPA and...

  10. Development of cost innovative BPs for a PEMFC stack for a 1 kW-class residential power generator (RPG) system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gil-yong; Jung, Min-kyung; Ryoo, Sung-nam; Ha, Sam-chul [Digital Appliance R and D, LG Electronics, Seoul 153-801 (Korea, Republic of); Park, Myung-seok [LG Solar Energy, Seoul 150-721 (Korea, Republic of); Kim, Sunhoe [Department of New Energy and Resource Engineering, Sangji University, Wonju, Gangwon 220-702 (Korea, Republic of)

    2010-12-15

    In order to satisfy the demands of customers, cost innovation of fuel cell systems is required for the commercialization of the fuel cell. Since the stack is one of the most expensive parts in a fuel cell system, cost reduction of stack is required for fuel cell commercialization. For this effort stainless steel 304 sheets were etched for the flow field and then coated for corrosion resistance. This enables the development of highly cost-effective bipolar plates (BPs) for a Proton Exchange Membrane Fuel Cell (PEMFC) stack of a 1 kW-class for Residential Power Generator (RPG). LG Electronics (LGE) developed a metal stack of 64 cells with the developed BPs and achieved a performance rating of 0.75 V/cell at 200 mA/cm{sup 2}. LGE also achieved a stack volume reduction of 20% compared to a stack of the same specifications consisting of graphite material BPs. The volume decrease can be represented as a cost reduction. LGE achieved the very low cost innovation to 1 USD per cell with cells developed from etched metal BPs. LGE also achieved 500 h of operation with LGE's RPG system; this test is still ongoing. The degradation rate of the stack was 27 {mu}V/hr. The end of life of the stack was estimated at approximately 17,000 h. (author)

  11. BPS Wilson loops in N=4 supersymmetric Yang-Mills theory: Examples on hyperbolic submanifolds of space-time

    International Nuclear Information System (INIS)

    In this paper we present a family of supersymmetric Wilson loops of N=4 supersymmetric Yang-Mills theory in Minkowski space. Our examples focus on curves restricted to hyperbolic submanifolds, H3 and H2, of space-time. Generically they preserve two supercharges, but in special cases more, including a case which has not been discussed before, of the hyperbolic line, conformal to the straight line and circle, which is 1/2 BPS. We discuss some general properties of these Wilson loops and their string duals and study special examples in more detail. Generically the string duals propagate on a complexification of AdS5xS5 and in some specific examples the compact sphere is effectively replaced by a de Sitter space.

  12. Taming the supergravity description of non-BPS D-branes: the D/anti-D solution

    Science.gov (United States)

    Bain, Pascal

    2001-04-01

    We obtain the supergravity solution which describes a bound state of D-string/anti-D-string pairs attached to different fixed planes of an orbifold, in type-IIB string theory compactified on T4/Bbb Z2. For parameters at which the conformal field theory point of view predicts stability, the solution displays a repulson-like singularity. However, we observe that a D-string/anti-D-string pair probe in this background becomes tensionless before reaching the singularity, suggesting a resolution by the enhançon mechanism. Moreover, the force feels by this probe is attractive, in contrast to the repulsive behaviour observed in the non-BPS D-brane description.

  13. Ultrasonic Digital Communication System for a Steel Wall Multipath Channel: Methods and Results

    Energy Technology Data Exchange (ETDEWEB)

    TL Murphy

    2006-02-16

    As of the development of this thesis, no commercially available products have been identified for the digital communication of instrumented data across a thick ({approx} 6 n.) steel wall using ultrasound. The specific goal of the current research is to investigate the application of methods for digital communication of instrumented data (i.e., temperature, voltage, etc.) across the wall of a steel pressure vessel. The acoustic transmission of data using ultrasonic transducers prevents the need to breach the wall of such a pressure vessel which could ultimately affect its safety or lifespan, or void the homogeneity of an experiment under test. Actual digital communication paradigms are introduced and implemented for the successful dissemination of data across such a wall utilizing solely an acoustic ultrasonic link. The first, dubbed the ''single-hop'' configuration, can communicate bursts of digital data one-way across the wall using the Differential Binary Phase-Shift Keying (DBPSK) modulation technique as fast as 500 bps. The second, dubbed the ''double-hop'' configuration, transmits a carrier into the vessel, modulates it, and retransmits it externally. Using a pulsed carrier with Pulse Amplitude Modulation (PAM), this technique can communicate digital data as fast as 500 bps. Using a CW carrier, Least Mean-Squared (LMS) adaptive interference suppression, and DBPSK, this method can communicate data as fast as 5 kbps. A third technique, dubbed the ''reflected-power'' configuration, communicates digital data by modulating a pulsed carrier by varying the acoustic impedance at the internal transducer-wall interface. The paradigms of the latter two configurations are believed to be unique. All modulation methods are based on the premise that the wall cannot be breached in any way and can therefore be viably implemented with power delivered wirelessly through the acoustic channel using ultrasound. Methods

  14. Topological-charge anomalies in supersymmetric theories with domain walls

    International Nuclear Information System (INIS)

    Domain walls in 1+2 dimensions are studied to clarify some general features of topological-charge anomalies in supersymmetric theories, by extensive use of a superfield supercurrent. For domain walls quantum modifications of the supercharge algebra arise not only from the short-distance anomaly but also from another source of long-distance origin, induced spin in the domain-wall background, and the latter dominates in the sum. A close look into the supersymmetric trace identity, which naturally accommodates the central-charge anomaly and its superpartners, shows an interesting consequence of the improvement of the supercurrent: Via an improvement the anomaly in the central-charge can be transferred from induced spin in the fermion sector to an induced potential in the boson sector. This fact reveals a dual character, both fermionic and bosonic, of the central-charge anomaly, which reflects the underlying supersymmetry. The one-loop superfield effective action is also constructed to verify the anomaly and Bogomol'nyi-Prasad-Sommerfield (BPS) saturation of the domain-wall spectrum

  15. Falling walls

    CERN Multimedia

    It was 20 years ago this week that the Berlin wall was opened for the first time since its construction began in 1961. Although the signs of a thaw had been in the air for some time, few predicted the speed of the change that would ensue. As members of the scientific community, we can take a moment to reflect on the role our field played in bringing East and West together. CERN’s collaboration with the East, primarily through links with the Joint Institute for Nuclear Research, JINR, in Dubna, Russia, is well documented. Less well known, however, is the role CERN played in bringing the scientists of East and West Germany together. As the Iron curtain was going up, particle physicists on both sides were already creating the conditions that would allow it to be torn down. Cold war historian Thomas Stange tells the story in his 2002 CERN Courier article. It was my privilege to be in Berlin on Monday, the anniversary of the wall’s opening, to take part in a conference entitled &lsquo...

  16. Roles of tyrosine-rich precursor glycoproteins and dityrosine- and 3,4-dihydroxyphenylalanine-mediated protein cross-linking in development of the oocyst wall in the coccidian parasite Eimeria maxima

    DEFF Research Database (Denmark)

    Belli, Sabina I; Wallach, Michael G; Luxford, Catherine; Davies, Michael Jonathan; Smith, Nicholas C

    2003-01-01

    The oocyst wall of apicomplexan parasites protects them from the harsh external environment, preserving their survival prior to transmission to the next host. If oocyst wall formation could be disrupted, then logically, the cycle of disease transmission could be stopped, and strategies to control...

  17. Exact Half-BPS Flux Solutions in M-theory III Existence and rigidity of global solutions asymptotic to AdS4 x S7

    CERN Document Server

    D'Hoker, Eric; Gutperle, Michael; Krym, Darya

    2009-01-01

    The BPS equations in M-theory for solutions with 16 residual supersymmetries, $SO(2,2)\\times SO(4)\\times SO(4)$ symmetry, and $AdS_4 \\times S^7$ asymptotics, were reduced in [arXiv:0806.0605] to a linear first order partial differential equation on a Riemann surface with boundary, subject to a non-trivial quadratic constraint. In the present paper, suitable regularity and boundary conditions are imposed for the existence of global solutions. We seek regular solutions with multiple distinct asymptotic $AdS_4 \\times S^7$ regions, but find that, remarkably, such solutions invariably reduce to multiple covers of the M-Janus solution found by the authors in [arXiv:0904.3313], suggesting rigidity of the half-BPS M-Janus solution. In particular, we prove analytically that no other smooth deformations away from the M-Janus solution exist, as such deformations invariably violate the quadratic constraint. These rigidity results are contrasted to the existence of half-BPS solutions with non-trivial 4-form fluxes and cha...

  18. Enabling Support of Collaborative Cross-enterprise Business Processes for Legacy ERP Systems

    OpenAIRE

    Alksnis, Gundars; Asņina, Ērika; Kirikova, Mārīte; Meiers, Egils

    2015-01-01

    In order to create innovative business products, share knowledge between people and businesses, or increase the control and quality of services, more and more often enterprise business processes involve in collaborations by delegating or providing some pieces of work to other enterprises. Necessity to cooperate in the cross-enterprise setting leads to Collaborative Business Processes (CBPs). The difference between CBPs and Business Processes (BPs) is in the decentralized coordination, flexibl...

  19. Abdominal wall hernia and pregnancy

    DEFF Research Database (Denmark)

    Jensen, K K; Henriksen, N A; Jorgensen, L N

    2015-01-01

    Med and Embase in combination with a cross-reference search of eligible papers. RESULTS: We included 31 papers of which 23 were case reports. In fertile women undergoing sutured or mesh repair, pain was described in a few patients during the last trimester of a subsequent pregnancy. Emergency surgery of......PURPOSE: There is no consensus as to the treatment strategy for abdominal wall hernias in fertile women. This study was undertaken to review the current literature on treatment of abdominal wall hernias in fertile women before or during pregnancy. METHODS: A literature search was undertaken in Pub...... incarcerated hernias in pregnant women, as well as combined hernia repair and cesarean section appears as safe procedures. No major complications were reported following hernia repair before or during pregnancy. The combined procedure of elective cesarean section and abdominal wall hernia repair was reported...

  20. Electrochemical behaviour of different redox probes on single wall carbon nanotube buckypaper-modified electrodes

    International Nuclear Information System (INIS)

    In the present work, the electrochemical properties of single-walled carbon nanotube buckypapers (BPs) were examined in terms of carbon nanotubes nature and preparation conditions. The performance of the different free-standing single wall carbon nanotube sheets was evaluated via cyclic voltammetry of several redox probes in aqueous electrolyte. Significant differences are observed in the electron transfer kinetics of the buckypaper-modified electrodes for both the outer- and inner-sphere redox systems. These differences can be ascribed to the nature of the carbon nanotubes (nanotube diameter, chirality and aspect ratio), surface oxidation degree and type of functionalities. In the case of dopamine, ferrocene/ferrocenium, and quinone/hydroquinone redox systems the voltammetric response should be thought as a complex contribution of different tips and sidewall domains which act as mediators for the electron transfer between the adsorbate species and the molecules in solution. In the other redox systems only nanotube ends are active sites for the electron transfer. It is also interesting to point out that a higher electroactive surface area not always lead to an improvement in the electron transfer rate of various redox systems. In addition, the current densities produced by the redox reactions studied here are high enough to ensure a proper electrochemical signal, which enables the use of BPs in sensing devices

  1. The normal growth of the tracheal wall in human foetuses

    OpenAIRE

    Szpinda, Michał; Daroszewski, Marcin; Szpinda, Anna; Woźniak, Alina; Mila-Kierzenkowska, Celestyna; Flisiński, Piotr; Wiśniewski, Marcin

    2012-01-01

    Introduction Tracheal wall thickness is a substantial indicator in various pathological changes. The present study was performed to compile normative data and formulae for the tracheal wall thickness and volume at varying gestational age. Material and methods Using anatomical dissection, digital image analysis and statistics a range of the wall thickness, proximal internal-to-external cross-sectional area ratio, and wall volume for the trachea in 73 spontaneously aborted human fetuses aged 14...

  2. Cell wall remodeling under abiotic stress

    OpenAIRE

    Tenhaken, Raimund

    2015-01-01

    Plants exposed to abiotic stress respond to unfavorable conditions on multiple levels. One challenge under drought stress is to reduce shoot growth while maintaining root growth, a process requiring differential cell wall synthesis and remodeling. Key players in this process are the formation of reactive oxygen species (ROS) and peroxidases, which initially cross-link phenolic compounds and glycoproteins of the cell walls causing stiffening. The function of ROS shifts after having converted a...

  3. Microanalysis of Plant Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Nicolai Obel; Veronika Erben; Tatjana Schwarz; Stefan Kühne; Andrea Fodor; Markus Pauly

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first iso-lating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apo-plastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.

  4. Distortional Modes of Thin-Walled Beams

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Andreassen, Michael Joachim

    2009-01-01

    The classic thin-walled beam theory for open and closed cross-sections can be generalized by including distortional displacement modes. The introduction of additional displacement modes leads to coupled differential equations, which seems to have prohibited the use of exact shape functions in the...

  5. The state of cell wall pectin monitored by wall associated kinases: A model

    OpenAIRE

    Kohorn, Bruce D

    2015-01-01

    The Wall Associated Kinases (WAKs) bind to both cross-linked polymers of pectin in the plant cell wall, but have a higher affinity for smaller fragmented pectins that are generated upon pathogen attack or wounding. WAKs are required for cell expansion during normal seedling development and this involves pectin binding and a signal transduction pathway involving MPK3 and invertase induction. Alternatively WAKs bind pathogen generated pectin fragments to activate a distinct MPK6 dependent stres...

  6. Performance Theory of Diagonal Conducting Wall MHD Accelerators

    Science.gov (United States)

    Litchford, R. J.

    2003-01-01

    The theoretical performance of diagonal conducting wall crossed field accelerators is examined on the basis of an infinite segmentation assumption using a cross-plane averaged generalized Ohm's law for a partially ionized gas, including ion slip. The desired accelerator performance relationships are derived from the cross-plane averaged Ohm's law by imposing appropriate configuration and loading constraints. A current dependent effective voltage drop model is also incorporated to account for cold-wall boundary layer effects including gasdynamic variations, discharge constriction, and electrode falls. Definition of dimensionless electric fields and current densities lead to the construction of graphical performance diagrams, which further illuminate the rudimentary behavior of crossed field accelerator operation.

  7. A simple fibril and lectin model for cyst walls of Entamoeba and perhaps Giardia

    OpenAIRE

    Samuelson, John; Robbins, Phillips

    2011-01-01

    Cyst walls of Entamoeba and Giardia protect them from environmental insults, stomach acids, and intestinal proteases. Each cyst wall contains a sugar homopolymer: chitin in Entamoeba and a unique N-acetylgalactosamine (GalNAc) homopolymer in Giardia. Entamoeba cyst wall proteins include Jacob lectins (carbohydrate-binding proteins) that cross-link chitin, chitinases that degrade chitin, and Jessie lectins that make walls impermeable. Giardia cyst wall proteins are also lectins that bind fibri...

  8. Tube wall thickness guage for hot stretch reducer

    International Nuclear Information System (INIS)

    A new system of tube wall thickness gauge for seamless tube on hot stretch reducing-mill is reported. The system adapts two methods using gamma rays. One is a new method measuring double wall thickness of tube another is a known method measuring mean value of cross section of tube. (author)

  9. Electron-wall interaction in Hall thrusters

    International Nuclear Information System (INIS)

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates. This result seemingly agrees with predictions of the temperature saturation, which recent Hall thruster models explain as a transition to space-charge saturated regime of the near-wall sheath. However, in the experiment, the maximum saturation temperature exceeds by almost three times the critical value estimated under the assumption of a Maxwellian electron energy distribution function. The channel narrowing, which should also enhance electron-wall collisions, causes unexpectedly larger changes of the plasma potential distribution than does the increase of the electron temperature with the discharge voltage. An enhanced anomalous crossed-field mobility (near wall or Bohm-type) is suggested by a hydrodynamic model as an explanation to the reduced electric field measured inside a narrow channel. We found, however, no experimental evidence of a coupling between the maximum electron temperature and the location of the accelerating voltage drop, which might have been expected due to the SEE-induced near-wall conductivity

  10. The landscape of string theory (orientifolds and their statistics, D-brane instantons, AdS4 domain walls and black holes)

    International Nuclear Information System (INIS)

    In this talk we discuss various aspects of the string landscape: D-brane model building and their statistics, the generation of non-perturbative superpotentials from D-brane instantons, moduli stabilization by fluxes and non-perturbative effects, the relation between flux vacua and BPS black holes, the construction of AdS4 vacua and related domain wall solutions, transitions between flux vacua and also some constraints on the string landscape from black hole considerations. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  11. Optimizing end-group cross-linking polymer electrolytes for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Lee, Kwan Soo [Los Alamos National Laboratory; Jeong, Myung - Hwan [GIST, KOREA; Lee, Jae - Suk [GIST, KOREA

    2009-01-01

    This paper demonstrates the optimization of proton conductivity and water uptake for cross-linkable polymer electrolytes through synthesis and characterization of end-group cross-linkable sulfonated poly(arylene ether) copolymers (ESF-BPs). The extent of reaction of cross-linking was controlled by reaction time resulting in a series of polymers with two, independent tunable parameters, degree of sulfonation (DS) and degree of cross-linking (DC). For the polymers presented, cross-linking improved proton conductivity while reducing water uptake, an uncommon trend in polymer electrolytes where water is critical for proton conduction. Other trends relating to changes are reported and the results yield insight into the role of DS and DC and how to optimize electrochemical properties and performance of polymer electrolytes through these tunable parameters. Select polymer electrolytes were tested in fuel cells where performance and durability with accelerated relative humidity cycling were compared with Nafion{reg_sign}.

  12. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful, a

  13. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  14. Timber frame walls

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Brandt, Erik

    2010-01-01

    A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding is...

  15. The Humming Wall

    DEFF Research Database (Denmark)

    Morrison, Ann Judith; Manresa-Yee, Cristina; Jensen, Brian Walther Skovgaard; Eshraghi, Neda

    2016-01-01

    We observed interactions with The Humming Wall, a vibrotactile and vibroacoustic interactive artifact placed in an urban park. Prior studies have focused on interactivity with primarily vision based systems (or with this system, the interaction between the wall and a wearable vibrotactile vest...

  16. Skyrmions and domain walls

    OpenAIRE

    Piette, B.; Zakrzewski, W. J.

    1997-01-01

    We study the 3+1 dimensional Skyrme model with a mass term different from the usual one. We show that this new model possesses domain walls solutions. We describe how, in the equivalent 2+1 dimensional model, the Skyrmion is absorbed by the wall.

  17. Numerical Simulation for Stress Concentration Factor at Cross Weld of Steel Pipe Piles in Identical Wall Thickness%等壁厚钢管桩横向焊缝应力集中系数的数值模拟

    Institute of Scientific and Technical Information of China (English)

    齐赵敏; 李怡; 段磊; 张一博; 王召兵

    2012-01-01

    Steel pipe piles are widely applied in large marine structure projects. Hoop butt-jointed welds are usually generated during the fabrication and installation of steel piles. The stress concentration at hoop butt-jointed welds caused by socket misalignment is an important factor which affects the hotspot stress evaluation and the safety analysis of fatigue welds. By the approximate analysis method,we research the stress concentration at the butt-jointed weld between the steel pipe piles in identical wall thickness under axial tension or in-plane bending moment,and furthermore develop an approximate formula for the stress concentration factor at the butt-jointed weld between the bending structures in identical wall thickness. According to a trial calculation of steel pipe piles model,the result by the approximate formula is very close to the value by ANSYS finite element numerical simulation,which will provide references for similar projects.%大型海洋工程结构多常用钢管桩,在钢管桩的制作和安装过程中通常会产生环向对接焊缝,由管节偏位引起的环向焊缝应力集中现象是焊缝疲劳热点应力评估和焊缝疲劳安全分析的重要影响因素.通过实用近似分析方法,研究在轴向拉力和平面内弯矩单独作用下等壁厚对接焊缝应力集中间题,得出等壁厚拉弯构件对接焊缝应力集中系数的近似计算公式;根据对钢管桩模型案例的试算,该近似公式的计算结果与ANSYS有限元数值模拟结果非常接近,可供实际工程参考.

  18. Solar Walls in tsbi3

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne

    tsbi3 is a user-friendly and flexible computer program, which provides support to the design team in the analysis of the indoor climate and the energy performance of buildings. The solar wall module gives tsbi3 the capability of simulating solar walls and their interaction with the building. This...... version, C, of tsbi3 is capable of simulating five types of solar walls say: mass-walls, Trombe-walls, double Trombe-walls, internally ventilated walls and solar walls for preheating ventilation air. The user's guide gives a description of the capabilities and how to simulate solar walls in tsbi3....

  19. First wall for NET

    International Nuclear Information System (INIS)

    In collaboration with ANSALDO and within the frame of the European Fusion Tecnology Task N1 (Plasma Facing Components Design Studies), ENEA has performed a design an manufacturing feasibility study for the first wall of the Next European Torus (NET) during its ''physics'' operation phase. The main design specifications are average neutron wall load=1 MW/m2, peak surface heat flux=0.4 MW/m2, total number of burn pulses=1*104, average burn pulse duration=100 s, average neutron fluence=0.03 MWy/m2, structure material=AISI 316L SA, coolant=H2O at 50/100 centigrates (in/out). The reference ENEA-ANSALDO design is based on the use of flat plates coupled by microbrazing to poloidal cooling tubes. The technological development work has led to the design and manufacturing of a representative NET first wall box segment (0.65x 0.25x0.15 m) mockup which will be tested in the 190 kW Thermal Fatique Test Facility at JRC-Ispra. In this paper, we report on the various aspects of the basic experimental and theoretical investigations on the plasma-wall interactions for adequate protection of the first wall against erosion, global stress analysis of the first wall box, thecnological tests on brazed joints, and disign and manufacturing of the first wall mockup

  20. Design Aspect of including Infill Wall in RC Frame Design*

    Directory of Open Access Journals (Sweden)

    Sukrawa, M.

    2014-01-01

    Full Text Available This study compares analysis and design of a four story reinforced concrete (RC frame structure with infill wall at upper levels and open at basement level. For the analysis, the RC frame are modeled as open frame (MOF and infilled-frames using six compression only cross diagonal strut (MIF-Strut, and infilled frame using shell elements (MIF-Shell. Another model, MIF-Full, is created by adding walls at basement level of the MIF-Strut to study the effect of wall discontinuity. All three dimensional models are loaded with gravity load and quake load appropriate for South Bali region. Results show that the infilled-frame models are 4.8 times stiffer than MOF in the wall direction. Perpendicular to the wall, however, the stiffness increase is 29%. Soft storey mechanism exists in the absence of wall at basement level, regardless of reasonable column dimensions.

  1. Plasma-wall interactions

    International Nuclear Information System (INIS)

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  2. "Steiner trees" between cell walls of sisal

    Institute of Scientific and Technical Information of China (English)

    LI GuanShi; YIN YaJun; LI Yan; ZHONG Zheng

    2009-01-01

    Through careful analysis on the cross-section of sisal fibers,it is found that the middle lamellae between the cell walls have clear geometric characteristics:between the cell walls of three neighboring cells,the middle lamellae form a three-way junction with 120°symmetry. If the neighboring three-way junctions are connected,a network of Steiner tree with angular symmetry and topological invariability is formed. If more and more Steiner trees are connected,a network of Steiner rings is generated. In another word,idealized cell walls and the middle lamellae are dominated by the Steiner geometry. This geometry not only depicts the geometric symmetry,the topological invariability and minimal property of the middle lamellae,but also controls the mechanics of sisal fibers.

  3. Automatic Wall Painting Robot

    OpenAIRE

    P.KEERTHANAA, K.JEEVITHA, V.NAVINA, G.INDIRA, S.JAYAMANI

    2013-01-01

    The Primary Aim Of The Project Is To Design, Develop And Implement Automatic Wall Painting Robot Which Helps To Achieve Low Cost Painting Equipment. Despite The Advances In Robotics And Its Wide Spreading Applications, Interior Wall Painting Has Shared Little In Research Activities. The Painting Chemicals Can Cause Hazards To The Human Painters Such As Eye And Respiratory System Problems. Also The Nature Of Painting Procedure That Requires Repeated Work And Hand Rising Makes It Boring, Time A...

  4. Plasma-wall interaction

    International Nuclear Information System (INIS)

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER

  5. Conducting Wall Hall Thrusters

    Science.gov (United States)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  6. The metabolic enzyme ManA reveals a link between cell wall integrity and chromosome morphology.

    OpenAIRE

    Maya Elbaz; Sigal Ben-Yehuda

    2010-01-01

    Author Summary The bacterial cell is resistant to extremes of osmotic pressure and protected against mechanical damages by the existence of a rigid outer shell defined as the cell wall. The strength of the cell wall is achieved by the presence of long glycan strands cross-linked by peptide side bridges. The cell wall is a dynamic structure continuously being synthesized and modified to allow for cell growth and division. Damaging the cell wall leads to abnormal cellular morphologies and cell ...

  7. Homogenization of a system of elastic and reaction-diffusion equations modelling plant cell wall biomechanics

    OpenAIRE

    Ptashnyk, Mariya; Seguin, Brian

    2014-01-01

    In this paper we present a derivation and multiscale analysis of a mathematical model for plant cell wall biomechanics that takes into account both the microscopic structure of a cell wall coming from the cellulose microfibrils and the chemical reactions between the cell wall's constituents. Particular attention is paid to the role of pectin and the impact of calcium-pectin cross-linking chemistry on the mechanical properties of the cell wall. We prove the existence and uniqueness of the stro...

  8. Quarter-BPS AdS 5 solutions in M-theory with a T 2 bundle over a Riemann surface

    Science.gov (United States)

    Bah, Ibrahima

    2013-08-01

    We study and classify quarter-BPS AdS 5 systems in M-theory, whose internal six-dimensional geometry is a T 2 bundle over a Riemann surface and two interval directions. The general system presented, provides a unified description of all known AdS 5 solutions in M-theory. These systems are governed by two functions, one that corresponds to the conformal factor of the Riemann surface and another that describes the T 2 fibration. We find a special set of solutions that can be organized into two classes. In the first one, solutions are specified by the conformal factor of the Riemann surface which satisfies a warped generalization of the SU(∞) Toda equation. The system in the second class requires the Riemann surface to be S 2, H 2 or T 2. Class one contains the M-theory AdS 5 solutions of Lin, Lunin and Maldacena; the solutions of Maldacena and Núñez; the solutions of Gauntlett, Martelli, Sparks and Waldram; and the eleven-dimensional uplift of the Y p, q metrics. The second includes the recently found solutions of Beem, Bobev, Wecht and the author. Within each class there are new solutions that will be studied in a companion paper.

  9. Charged BPS vortices and reversal of the magnetic flux in a Maxwell-Higgs type model without the Chern-Simons term

    Energy Technology Data Exchange (ETDEWEB)

    Cantanhede, Carlisson M. [Instituto de Fisica Teorica (IFT/UNESP), Sao Paulo, SP (Brazil); Casana, Rodolfo; Ferreira Junior, Manoel M. [Universidade Federal do Maranhao (UFMA), MA (Brazil). Dept. de Fisica; Hora, Eduardo da [Universidade Federal da Paraiba (UFPB), PB (Brazil). Dept. de Fisica

    2012-07-01

    Full text: Since the seminal works by Abrikosov [1] and Nielsen-Olesen [2] showing the existence of uncharged vortex, such nonperturbative solutions have been a theoretical issue of enduring interest. Already, the electrically charged vortices are obtained only in abelian models endowed with the Chern-Simons term [3,4]. This remains valid even in the context of highly nonlinear models, such as the Born-Infield electrodynamics. In this work, we demonstrated the existence of electrically charged BPS vortices in a Maxwell-Higgs model without the Chern- Simons term but endowed with a CPT-even and parity-odd Lorentz-violating (LV) structure. The LV term belonging to the CPT-even electrodynamics of the Standard Model Extension [5] plays a similar role that of the Chern-Simons term, mixing the electric and magnetic sectors. Besides the LV coefficients provide a very rich set of vortex configurations exhibiting electric's field inversion also are responsible by controlling the characteristic length of the vortex and by the flipping of the magnetic flux. [1] A. Abrikosov, Sov. Phys. JETP 32, 1442 (1957). [2] H. Nielsen, P. Olesen, Nucl. Phys. B 61, 45 (1973). [3] R. Jackiw and E. J. Weinberg, Phys. Rev. Lett. 64, 2234 (1990). [4] C.K. Lee, K.M. Lee, H. Min, Phys. Lett. B 252, 79 (1990) [5] D. Colladay and V. A. Kostelecky, Phys. Rev. D 55, 6760 (1997); Phys. Rev. D 58, 116002 (1998). (author)

  10. The Chlamydomonas cell wall: characterization of the wall framework

    OpenAIRE

    1985-01-01

    The cell wall of the biflagellate alga Chlamydomonas reinhardtii is a multilayered, extracellular matrix composed of carbohydrates and 20-25 polypeptides. To learn more about the forces responsible for the integrity of this cellulose-deficient cell wall, we have begun studies to identify and characterize the framework of the wall and to determine the effects of the cell wall-degrading enzyme, lysin, on framework structure and protein composition. In these studies we used walls released into t...

  11. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  12. Concept modeling of tapered thin-walled tubes

    Institute of Scientific and Technical Information of China (English)

    Yu-cheng LIU; Michael L.DAY

    2009-01-01

    This paper presents a method to create concept models for the tapered thin-walled tubes using beam elements and spring elements. Developed concept tapered beam models with different taper angles and cross sections are compared with those detailed models through impact analyses. Important crash results are recorded and compared, and the relatively good agreement is achieved between these analyses. Concept modeling steps are illustrated in detail, and a general concept modeling method for such thin-walled tubes is summarized and presented.

  13. A distortional semi-discretized thin-walled beam element

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2013-01-01

    based on a generalized beam theory (GBT), in which the classic Vlasov beam theory for analysis of open and closed thin-walled cross sections is generalized by including distortional displacements. The beam element formulation utilizes a semi-discretization approach in which the cross section is...... element including distortional contributions. It should be noticed that we are only dealing with a basic generalized beam theory and not an extended finite element formulation of an approximate beam element, which allows the addition of special (transverse extension and shear lag) modes. Illustrative......Due to the increased consumption of thin-walled structural elements there has been increasing focus and need for more detailed calculations as well as development of new approaches. In this paper a thin-walled beam element including distortion of the cross section is formulated. The formulation is...

  14. Double wall underground storage tank

    Energy Technology Data Exchange (ETDEWEB)

    Canaan, E.B. Jr.; Wiegand, J.R.; Bartlow, D.H.

    1993-07-06

    A double wall underground storage tank is described comprising: (a) a cylindrical inner wall, (b) a cylindrical outer wall comprising plastic resin and reinforcement fibers, and (c) a layer of spacer filaments wound around the inner wall, the spacer filaments separating the inner and outer walls, and the spacer filaments being at least partially surrounded by voids to enable liquids to flow along the filaments.

  15. Back Reaction from Walls

    CERN Document Server

    Di Dio, Enea; Durrer, Ruth

    2011-01-01

    We study the distance-redshift relation in a universe filled with 'walls' of pressure-less dust separated by under dense regions. We show that as long as the density contrast of the walls is small, or the diameter of the under dense regions is much smaller than the Hubble scale, the distance-redshift relation remains close to what is obtained in a Friedmann universe. However, when arbitrary density contrasts are allowed, every prescribed distance-redshift relation can be reproduced with such models.

  16. Occupy Wall Street

    DEFF Research Database (Denmark)

    Jensen, Michael J.; Bang, Henrik

    2013-01-01

    This article analyzes the political form of Occupy Wall Street on Twitter. Drawing on evidence contained within the profiles of over 50,000 Twitter users, political identities of participants are characterized using natural language processing. The results find evidence of a traditional oppositio......This article analyzes the political form of Occupy Wall Street on Twitter. Drawing on evidence contained within the profiles of over 50,000 Twitter users, political identities of participants are characterized using natural language processing. The results find evidence of a traditional...

  17. UWB Propagation through Walls

    Directory of Open Access Journals (Sweden)

    M. Hajek

    2006-04-01

    Full Text Available The propagation of ultra wide band (UWB signals through walls is analyzed. For this propagation studies, it is necessary to consider not only propagation at a single frequency but in the whole band. The UWB radar output signal is formed by both transmitter and antenna. The effects of antenna receiving and transmitting responses for various antenna types (such as small and aperture antennas are studied in the frequency as well as time domain. Moreover, UWB radar output signals can be substantially affected due to electromagnetic wave propagation through walls and multipath effects.

  18. Side-wall sampler

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, B.

    1969-11-01

    A side-wall sampler which is capable of taking samples from the walls of test holes to a depth of 1,000 ft or more is described. Samples have been extracted from till, clay, silt, and fine- to coarse-grained sands in drift and nonindurated bedrock from more than 1,000 test holes in S. Saskatchewan. Side-hole sampling is faster and cheaper than conventional sampling methods and is ideally suited for geological investigations. Mineralogical paleonto- locical and radiocarbon analyses have been determined on side-hole cores.

  19. Source of the Kerr-Newman Solution as a Supersymmetric Domain-Wall Bubble: 50 years of the problem

    CERN Document Server

    Burinskii, Alexander

    2016-01-01

    We consider the chiral field model of the source of the Kerr-Newman (KN) solution and obtain that it represents a supersymmetric spinning soliton, bounded by the chiral domain wall (DW) of the ellipsoidal form. The known method for transformation of the planar DW to Bogomolnyi form we generalize to the curved DW-bubble adapted to the Kerr coordinate system and obtain the supersymmetric BPS-saturated source of the KN solution, having some remarkable features, in particular, the quantum angular momentum. The main new result is that the source forms a breather, i.e. the DW-antiDW combination. Taking into account that the KN solution describes the spinning particles with gyromagnetic ratio g = 2, as that of the Dirac electron, we touch the problem of the compatibility of the spinning particles with gravity.

  20. Fly on the Wall

    Science.gov (United States)

    Berry, Dave; Korpan, Cynthia

    2009-01-01

    This paper describes the implementation of a peer observation program at the University of Victoria called the Lecture Club. The observers are not interactive during the class--they are the proverbial flies on the wall. The paper identifies the program as self-developmental, discussing the attributes of this learning-to-teach and peer-sharing…

  1. Endometriosis Abdominal wall

    International Nuclear Information System (INIS)

    Endometriosis of abdominal wall is a rare entity wi ch frequently appears after gynecological surgery. Case history includes three cases of parietal endometriosis wi ch were treated in Maciel Hospital of Montevideo. The report refers to etiological diagnostic aspects and highlights the importance of total resection in order to achieve definitive healing

  2. Anterior vaginal wall repair

    Science.gov (United States)

    ... symptoms will go away. This improvement will often last for years. Alternative Names A/P repair; Vaginal wall repair; Anterior and/ ... writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Contact ... Institutes of Health Page last updated: 23 August 2016

  3. The Invisible Wall.

    Science.gov (United States)

    Zenger, John H.

    1997-01-01

    The barrier to a company's performance may be a conflict of organizational values and culture with those of the training profession. Elements of this value system that create the invisible wall are egalitarianism, people focus, "guerilla" training tactics, and emphasis on human interaction. (JOW)

  4. Inter-wall bridging induced peeling of multi-walled carbon nanotubes during tensile failure in aluminum matrix composites.

    Science.gov (United States)

    Chen, Biao; Li, Shufeng; Imai, Hisashi; Umeda, Junko; Takahashi, Makoto; Kondoh, Katsuyoshi

    2015-02-01

    In situ scanning electron microscopy (SEM) observation of a tensile test was performed to investigate the fracturing behavior of multi-walled carbon nanotubes (MWCNTs) in powder metallurgy Al matrix composites. A multiple peeling phenomenon during MWCNT fracturing was clearly observed. Its formation mechanism and resultant effect on the composite strength were examined. Through transition electron microscopy characterizations, it was observed that defective structures like inter-wall bridges cross-linked adjacent walls of MWCNTs. This structure was helpful to improve the inter-wall bonding conditions, leading to the effective load transfer between walls and resultant peeling behaviors of MWCNTs. These results might provide new understandings of the fracturing mechanisms of carbon nanotube reinforcements for designing high-performance nanocomposites. PMID:25437849

  5. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, Pallavi [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  6. Experimental investigation of the wall shear stress and the vortex dynamics in a circular impinging jet

    Energy Technology Data Exchange (ETDEWEB)

    El Hassan, Mouhammad; Vetel, Jerome; Garon, Andre [Ecole Polytechnique de Montreal, Department of Mechanical Engineering, LADYF, Montreal, Quebec (Canada); Assoum, Hassan Hassan; Sobolik, Vaclav; Abed-Meraim, Kamel; Sakout, Anas [LaSIE, Universite de La Rochelle, La Rochelle (France)

    2012-06-15

    The wall shear stress and the vortex dynamics in a circular impinging jet are investigated experimentally for Re = 1,260 and 2,450. The wall shear stress is obtained at different radial locations from the stagnation point using the polarographic method. The velocity field is given from the time resolved particle image velocimetry (TR-PIV) technique in both the free jet region and near the wall in the impinging region. The distribution of the momentum thickness is also inspected from the jet exit toward the impinged wall. It is found that the wall shear stress is correlated with the large-scale vortex passing. Both the primary vortices and the secondary structures strongly affect the variation of the wall shear stress. The maximum mean wall shear stress is obtained just upstream from the secondary vortex generation where the primary structures impinge the wall. Spectral analysis and cross-correlations between the wall shear stress fluctuations show that the vortex passing influences the wall shear stress at different locations simultaneously. Analysis of cross-correlations between temporal fluctuations of the wall shear stress and the transverse vorticity brings out the role of different vortical structures on the wall shear stress distribution for the two Reynolds numbers. (orig.)

  7. Experimental investigation of the wall shear stress and the vortex dynamics in a circular impinging jet

    Science.gov (United States)

    El Hassan, Mouhammad; Assoum, Hassan Hassan; Sobolik, Vaclav; Vétel, Jérôme; Abed-Meraim, Kamel; Garon, André; Sakout, Anas

    2012-06-01

    The wall shear stress and the vortex dynamics in a circular impinging jet are investigated experimentally for Re = 1,260 and 2,450. The wall shear stress is obtained at different radial locations from the stagnation point using the polarographic method. The velocity field is given from the time resolved particle image velocimetry (TR-PIV) technique in both the free jet region and near the wall in the impinging region. The distribution of the momentum thickness is also inspected from the jet exit toward the impinged wall. It is found that the wall shear stress is correlated with the large-scale vortex passing. Both the primary vortices and the secondary structures strongly affect the variation of the wall shear stress. The maximum mean wall shear stress is obtained just upstream from the secondary vortex generation where the primary structures impinge the wall. Spectral analysis and cross-correlations between the wall shear stress fluctuations show that the vortex passing influences the wall shear stress at different locations simultaneously. Analysis of cross-correlations between temporal fluctuations of the wall shear stress and the transverse vorticity brings out the role of different vortical structures on the wall shear stress distribution for the two Reynolds numbers.

  8. Rising damp in building walls: the wall base ventilation system

    Science.gov (United States)

    Guimarães, A. S.; Delgado, J. M. P. Q.; de Freitas, V. P.

    2012-12-01

    This work intends to validate a new system for treating rising damp in historic buildings walls. The results of laboratory experiments show that an efficient way of treating rising damp is by ventilating the wall base, using the HUMIVENT technique. The analytical model presented describes very well the observed features of rising damp in walls, verified by laboratory tests, who contributed for a simple sizing of the wall base ventilation system that will be implemented in historic buildings.

  9. Performance Theory of Diagonal Conducting Wall Magnetohydrodynamic Accelerators

    Science.gov (United States)

    Litchford, R. J.

    2004-01-01

    The theoretical performance of diagonal conducting wall crossed-field accelerators is examined on the basis of an infinite segmentation assumption using a cross-plane averaged generalized Ohm s law for a partially ionized gas, including ion slip. The desired accelerator performance relationships are derived from the cross-plane averaged Ohm s law by imposing appropriate configuration and loading constraints. A current-dependent effective voltage drop model is also incorporated to account for cold-wall boundary layer effects, including gasdynamic variations, discharge constriction, and electrode falls. Definition of dimensionless electric fields and current densities leads to the construction of graphical performance diagrams, which further illuminate the rudimentary behavior of crossed-field accelerator operation.

  10. High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  11. High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Kochkin, V. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  12. Interactions of tokamak plasma with solid walls

    International Nuclear Information System (INIS)

    The interactions of tokamak fusion plasmas with solid walls of the devices were investigated on special model systems. The elastic recoil detection method was used for the determination of absolute hydrogen concentration. For the calibration of the method the scattering cross sections were measured in large ranges of scattering angle and energy. The erosion and deformation of wall surfaces were investigated by reemission of accelerated He ions. Theoretical models were developed to describe the surface undulation discovered earlier, caused by large dose He irradiation. The surface sputtering and segregation were investigated by nuclear methods and the mechanism of sputtering was simulated by computer. The surface deformation and gas reemission of Al surfaces were analyzed by Ar implementation and heat treatment. (D.Gy.) 6 figs

  13. Automatic Wall Painting Robot

    Directory of Open Access Journals (Sweden)

    P.KEERTHANAA, K.JEEVITHA, V.NAVINA, G.INDIRA, S.JAYAMANI

    2013-07-01

    Full Text Available The Primary Aim Of The Project Is To Design, Develop And Implement Automatic Wall Painting Robot Which Helps To Achieve Low Cost Painting Equipment. Despite The Advances In Robotics And Its Wide Spreading Applications, Interior Wall Painting Has Shared Little In Research Activities. The Painting Chemicals Can Cause Hazards To The Human Painters Such As Eye And Respiratory System Problems. Also The Nature Of Painting Procedure That Requires Repeated Work And Hand Rising Makes It Boring, Time And Effort Consuming. When Construction Workers And Robots Are Properly Integrated In Building Tasks, The Whole Construction Process Can Be Better Managed And Savings In Human Labour And Timing Are Obtained As A Consequence. In Addition, It Would Offer The Opportunity To Reduce Or Eliminate Human Exposure To Difficult And Hazardous Environments, Which Would Solve Most Of The Problems Connected With Safety When Many Activities Occur At The Same Time. These Factors Motivate The Development Of An Automated Robotic Painting System.

  14. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  15. In a walled garden

    OpenAIRE

    Mullaniff, Kathleen

    2009-01-01

    Mullaniff exhibited one painting from the series, ‘in a walled garden’. These works are based on a Victorian garden at St Leonards on Sea. An investigation into the history of the house and garden built 1860. This research endeavors to explore the progression of restoring the original Victorian garden, as recorded through the painting and drawing process This involves forming links between the past domestic histories and the current site. The research is based on the botanical paintings of Ma...

  16. New Formulations of D=10 Supersymmetry and D8-O8 Domain Walls

    CERN Document Server

    Bergshoeff, E A; Ortín, Tomas; Roest, D; Van Proeyen, A

    2001-01-01

    We discuss a generalized form of IIA/IIB supergravity depending on all R-R potentials C^(p) (p=0,1,...,9) as the effective field theory of Type IIA/IIB superstring theory. For the IIA case we explicitly break this R-R democracy to either p=5 which allows us to write a new bulk action that can be coupled to N=1 supersymmetric brane actions. The case of 8-branes is studied in detail using the new bulk & brane action. The supersymmetric negative tension branes without matter excitations can be viewed as orientifolds in the effective action. These D8-branes and O8-planes are fundamental in Type I' string theory. A BPS 8-brane solution is given which satisfies the jump conditions on the wall. It implies a quantization of the mass parameter in string units. Also we find a maximal distance between the two walls, depending on the string coupling and the mass parameter. We derive the same results via supersymmetric flow equations.

  17. Light shining through walls

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    Shining light through walls? At first glance this sounds crazy. However, very feeble gravitational and electroweak effects allow for this exotic possibility. Unfortunately, with present and near future technologies the opportunity to observe light shining through walls via these effects is completely out of question. Nevertheless there are quite a number of experimental collaborations around the globe involved in this quest. Why are they doing it? Are there additional ways of sending photons through opaque matter? Indeed, various extensions of the standard model of particle physics predict the existence of new particles called WISPs - extremely weakly interacting slim particles. Photons can convert into these hypothetical particles, which have no problems to penetrate very dense materials, and these can reconvert into photons after their passage - as if light was effectively traversing walls. We review this exciting field of research, describing the most important WISPs, the present and future experiments, the indirect hints from astrophysics and cosmology pointing to the existence of WISPs, and finally outlining the consequences that the discovery of WISPs would have. (orig.)

  18. Light shining through walls

    International Nuclear Information System (INIS)

    Shining light through walls? At first glance this sounds crazy. However, very feeble gravitational and electroweak effects allow for this exotic possibility. Unfortunately, with present and near future technologies the opportunity to observe light shining through walls via these effects is completely out of question. Nevertheless there are quite a number of experimental collaborations around the globe involved in this quest. Why are they doing it? Are there additional ways of sending photons through opaque matter? Indeed, various extensions of the standard model of particle physics predict the existence of new particles called WISPs - extremely weakly interacting slim particles. Photons can convert into these hypothetical particles, which have no problems to penetrate very dense materials, and these can reconvert into photons after their passage - as if light was effectively traversing walls. We review this exciting field of research, describing the most important WISPs, the present and future experiments, the indirect hints from astrophysics and cosmology pointing to the existence of WISPs, and finally outlining the consequences that the discovery of WISPs would have. (orig.)

  19. Rank 2 wall-crossing and the Serre correspondence

    CERN Document Server

    Gholampour, A

    2016-01-01

    Let $\\mathcal{R}$ be a rank 2 reflexive sheaf on a smooth projective 3-fold $X$. We are interested in the Euler characteristics of the Quot schemes $\\mathrm{Quot}(\\mathcal{R},n)$ of 0-dimensional quotients of $\\mathcal{R}$ of length $n$. Provided $\\mathcal{R}$ admits a cosection cutting out a 1-dimensional subscheme, we prove that the generating function of these Euler characteristics is equal to $M(q)^{2e(X)}$ times a polynomial of degree $c_3(\\mathcal{R})$. This polynomial is the generating function of Euler characteristics of $\\mathrm{Quot}(\\mathcal{E}{\\it{xt}}^1(\\mathcal{R},\\mathcal{O}_X),n)$. Here $\\mathcal{E}{\\it{xt}}^1(\\mathcal{R},\\mathcal{O}_X)$ is a 0-dimensional sheaf supported at the points where $\\mathcal{R}$ is not locally free. Since $\\mathcal{R}$ is reflexive, it admits a 2-term resolution by vector bundles. In the case the vector bundles are of rank 1 and 3, $\\mathcal{E}{\\it{xt}}^1(\\mathcal{R},\\mathcal{O}_X)$ is a structure sheaf. This observation is used to prove a closed product formula for ...

  20. Canal Wall Reconstruction Mastoidectomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the advantages of canal wall reconstruction (CWR) mastoidectomy, a single-stage technique for cholesteatoma removal and posterior external canal wall reconstruction, over the open and closed procedures in terms of cholesteatoma recurrence. Methods: Between June 2002 and December 2005, 38 patients (40 ears) with cholesteatoma were admited to Sun Yat-Sen Memorial Hospital and received surgical treatments. Of these patients, 25 were male with ages ranging between 11 and 60 years (mean = 31.6 years) and 13 were female with ages ranging between 20 and 65 years (mean = 38.8 years). Canal wall reconstruction (CWR)mastoidectomy was performed in 31 ears and canal wall down (CWD) mastoidectomy in 9 ears. Concha cartilage was used for ear canal wall reconstruction in 22 of the 31 CWR procedures and cortical mastoid bone was used in the remaining 9 cases. Results At 0.5 to 4 years follow up, all but one patients remained free of signs of cholesteatoma recurrence, i.e., no retraction pocket or cholesteatoma matrix. One patient, a smoker, needed revision surgery due to cholesteatoma recurrence 1.5 year after the initial operation. The recurrence rate was therefore 3.2% (1/31). Cholesteatoma recurrence was monitored using postoperative CT scans whenever possible. In the case that needed a revision procedure, a retraction pocket was identified by otoendoscopy in the pars flacida area that eventually evolved into a cholesteatoma. A pocket extending to the epitympanum filled with cholesteatoma matrix was confirmed during the revision operation, A decision to perform a modified mastoidectomy was made as the patient refused to quit smoking. The mean air-bone gap in pure tone threshold was 45 dB before surgery and 25 dB after (p < 0.05). There was no difference between using concha cartilage and cortical mastoid bone for the reconstruction regarding air-bone gap improvement, CT findings and otoendoscopic results. Conclusion CWR mastoidectomy can be used for

  1. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox

    2011-01-01

    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  2. Photodetachment of H- near a hard wall with arbitrary laser polarization direction

    Science.gov (United States)

    Iqbal, Azmat; Afaq, A.

    2015-08-01

    The photodetachment of H- near a hard wall is investigated with linear polarized laser light travelling in arbitrary direction θL with respect to the z axis. An analytical formula for the total cross section is derived using semi-classical closed orbit theory, which consists of two terms, i.e., the smooth background term and the oscillatory term with an extra factor 2(θL). This factor controls oscillations in the total photodetachment cross section. The amplitude of oscillation is maximum at θL = 0 when the laser polarization direction is perpendicular to the wall and it approaches zero at θL = π /2 when the laser polarization direction is parallel to the wall. It is also observed that the total cross section depends on the source-wall distance and it reduces to a free space case when the wall is at infinite distance from the source.

  3. Cross polarization caused by perturbed circular cross sections of waveguides and horn antennas

    Science.gov (United States)

    Lier, Erik

    1987-03-01

    The cross polarization caused by a perturbed cross section of the conical hybrid-mode horn is analyzed. The perturbed cross section is assumed to be slightly elliptical. The theory of Lier and Bergh (1986) for cross polarization in a smooth-walled waveguide supporting the TE11-mode is referred and applied to the HE11 mode as well. Simple analytical formulas which are sufficiently accurate for small ellipticites of the cross-section ellipse are presented. These show that the tolerances on the waveguide diameter are extremely strong, typically on the order of 0.02-0.04 mm in the horn throat for typical horn geometries at 12 GHz.

  4. Digital radiography for automated wall thickness measurement at insulated pipes

    International Nuclear Information System (INIS)

    The digital radiography system AMICA-410 enables the measurement of pipe wall thickness as well as pipe cross section at insulated and non-insulated pipework, and on stream processing and analysis of data with the integrated software. The hardware and software of the system and its performance are explained in the context of the scanning tasks. (orig./CB)

  5. The Neurospora crassa dfg5 and dcw1 Genes Encode α-1,6-Mannanases That Function in the Incorporation of Glycoproteins into the Cell Wall

    OpenAIRE

    Abhiram Maddi; Ci Fu; Free, Stephen J.

    2012-01-01

    The covalent cross-linking of cell wall proteins into the cell wall glucan/chitin matrix is an important step in the biogenesis of the fungal cell wall. We demonstrate that the Neurospora crassa DFG5 (NCU03770) and DCW1 (NCU08127) enzymes function in vivo to cross-link glycoproteins into the cell wall. Mutants lacking DFG5 or DCW1 release slightly elevated levels of cell wall proteins into their growth medium. Mutants lacking both DFG5 and DCW1 have substantially reduced levels of cell wall p...

  6. The cell-wall glycoproteins of the green alga Scenedesmus obliquus. The predominant cell-wall polypeptide of Scenedesmus obliquus is related to the cell-wall glycoprotein gp3 of Chlamydomonas reinhardtii.

    Science.gov (United States)

    Voigt, Jürgen; Stolarczyk, Adam; Zych, Maria; Malec, Przemysław; Burczyk, Jan

    2014-02-01

    The green alga Scenedesmus obliquus contains a multilayered cell wall, ultrastructurally similar to that of Chlamydomonas reinhardtii, although its proportion of hydroxyproline is considerably lower. Therefore, we have investigated the polypeptide composition of the insoluble and the chaotrope-soluble wall fractions of S. obliquus. The polypeptide pattern of the chaotrope-soluble wall fraction was strongly modified by chemical deglycosylation with anhydrous hydrogen fluoride (HF) in pyridine indicating that most of these polypeptides are glycosylated. Polypeptide constituents of the chaotrope-soluble cell-wall fraction with apparent molecular masses of 240, 270, 265, and 135 kDa cross-reacted with a polyclonal antibody raised against the 100 kDa deglycosylation product of the C. reinhardtii cell-wall glycoprotein GP3B. Chemical deglycosylation of the chaotrope-soluble wall fraction resulted in a 135 kDa major polypeptide and a 106 kDa minor component reacting with the same antibody. This antibody recognized specific peptide epitopes of GP3B. When the insoluble wall fraction of S. obliquus was treated with anhydrous HF/pyridine, three polypeptides with apparent molecular masses of 144, 135, and 65 kDa were solubilized, which also occured in the deglycosylated chaotrope-soluble wall fraction. These findings indicate that theses glycoproteins are cross-linked to the insoluble wall fraction via HF-sensitive bonds. PMID:24388513

  7. On the domain wall partition functions of level-1 affine so(n) vertex models

    OpenAIRE

    Dow, A.; Foda, O.

    2006-01-01

    We derive determinant expressions for domain wall partition functions of level-1 affine so(n) vertex models, n >= 4, at discrete values of the crossing parameter lambda = m pi / 2(n-3), m in Z, in the critical regime.

  8. Influence of Wall Teichoic Acid on Lysozyme Resistance in Staphylococcus aureus▿

    OpenAIRE

    Bera, Agnieszka; Biswas, Raja; Herbert, Silvia; Kulauzovic, Emir; Weidenmaier, Christopher; Peschel, Andreas; Götz, Friedrich

    2006-01-01

    Staphylococcus aureus peptidoglycan (PG) is completely resistant to the hydrolytic activity of lysozyme. Here we show that modifications in PG by O acetylation, wall teichoic acid, and a high degree of cross-linking contribute to this resistance.

  9. Correlations of coronary plaque wall thickness with wall pressure and wall pressure gradient: a representative case study

    OpenAIRE

    Liu Biyue; Zheng Jie; Bach Richard; Tang Dalin

    2012-01-01

    Abstract Background There are two major hemodynamic stresses imposed at the blood arterial wall interface by flowing blood: the wall shear stress (WSS) acting tangentially to the wall, and the wall pressure (WP) acting normally to the wall. The role of flow wall shear stress in atherosclerosis progression has been under intensive investigation, while the impact of blood pressure on plaque progression has been under-studied. Method The correlations of wall thickness (WT) with wall pressure (WP...

  10. Forward Wall Detector

    International Nuclear Information System (INIS)

    The Forward Wall Detector is designed to identify projectile like fragments from heavy ion reactions at CELSIUS storage ring in Uppsala, Sweden. The FWD consist of 96 detection modules covering azimuthal angle from 3.9o to 11.7o with efficiency of 81%. The detection module can be either of phoswitch type (10 mm fast plastic + 80 mm CsI(Tl)) or standard ΔE-E telescope (750 μm Si + 88 mm CsI(Tl)). It is expected to have charge identification up to Z=18, mass resolution for H and He isotopes and energy resolution ∼ 8%. (author)

  11. AKt/mTOR 信号通路中 p70S6K1、4E -BPs 在促进肿瘤发生作用中的研究进展%The research progress of p70S6K1 and 4E -BPs of the AKt/mTOR signal pathway in pro-moting the occurrence of tumor

    Institute of Scientific and Technical Information of China (English)

    杨柳; 李昕

    2016-01-01

    The PI3K/AKt/mTOR signal pathway can be activated when cells are stimulated by growth factors to con-trol the growth,proliferation,survive and apoptosis of the cells.AKt/mTOR signaling pathways plays an important role in promoting the development process of tumor.AKt/mTOR signal pathway can inhibit apoptosis in tumor cells,pro-mote the invasion and metastasis of tumor cells,the cell cycle progression and the formation of tumor blood vessels to promote the occurrence of tumor via p70S6K1 and 4E -BPs.In this paper,the mechanism of how the AKt/mTOR sig-naling pathway facilitate the formation of tumors through p70S6K1 and 4E -BPs was reviewed.%当受细胞外生长因子等刺激作用后,可激活 PI3K/AKt/mTOR 信号通路,参与控制细胞的生长、增殖、生存、凋亡。AKt/mTOR 信号通路在肿瘤的发生发展过程中起着很重要的促进作用。AKt/mTOR 信号通路在肿瘤细胞中能够通过 p70S6K1和4E -BPs 的作用抑制细胞的凋亡,促进核糖体以及蛋白质的合成、促进肿瘤细胞的侵袭和转移、促进细胞周期进展、促进肿瘤血管的生成,进而促进肿瘤的发生发展。本文就AKt/mTOR 信号通路通过 p70S6K1和4E -BPs 促进肿瘤发生的机制进行综述。

  12. Crossing Filaments

    CERN Document Server

    Filippov, Boris

    2011-01-01

    Solar filaments show the position of large scale polarity inversion lines and are used for the reconstruction of large-scale solar magnetic field structure on the basis of H{\\alpha} synoptic charts for the periods when magnetographic measurements were not available. Sometimes crossing filaments are seen in H{\\alpha} filtergrams. We analyze daily H{\\alpha} filtergrams from the archive of Big Bear Solar Observatory for the period of 1999-2003 to find crossing and interacting filaments. A number of examples are presented and filament patterns are compared with photospheric magnetic field distributions. We have found that all crossing filaments reveal quadrupolar magnetic configurations of the photospheric field and presume the presence of null points in the corona.

  13. Glucuronoarabinoxylan structure in the walls of Aechmea leaf chlorenchyma cells is related to wall strength.

    Science.gov (United States)

    Ceusters, Johan; Londers, Elsje; Brijs, Kristof; Delcour, Jan A; De Proft, Maurice P

    2008-09-01

    In CAM-plants rising levels of malic acid in the early morning cause elevated turgor pressures in leaf chlorenchyma cells. Under specific conditions this process is lethal for sensitive plants resulting in chlorenchyma cell burst while other species can cope with these high pressures and do not show cell burst under comparable conditions. The non-cellulosic polysaccharide composition of chlorenchyma cell walls was investigated and compared in three cultivars of Aechmea with high sensitivity for chlorenchyma cell burst and three cultivars with low sensitivity. Chlorenchyma layers were cut from the leaf and the non-cellulosic carbohydrate fraction of the cell wall fraction was analyzed by gas-liquid chromatography. Glucuronoarabinoxylans (GAXs) were the major non-cellulosic polysaccharides in Aechmea. The fine structure of these GAXs was strongly related to chlorenchyma wall strength. Chlorenchyma cell walls from cultivars with low sensitivity to cell burst were characterized by an A/X ratio of ca. 0.13 while those from cultivars with high sensitivity showed an A/X ratio of ca. 0.23. Xylose chains from cultivars with high cell burst sensitivity were ca. 40% more substituted with arabinose compared to cultivars with low sensitivity for cell burst. The results indicate a relationship in vivo between glucuronoarabinoxylan fine structure and chlorenchyma cell wall strength in Aechmea. The evidence obtained supports the hypothesis that GAXs with low degrees of substitution cross-link cellulose microfibrils, while GAXs with high degrees of substitution do not. A lower degree of arabinose substitution on the xylose backbone implies stronger cell walls and the possibility of withstanding higher internal turgor pressures without cell bursting. PMID:18632122

  14. Pectic homogalacturonan masks abundant sets of xyloglucan epitopes in plant cell walls

    DEFF Research Database (Denmark)

    Marcus, Susan E; Verhertbruggen, Yves; Hervé, Cécile;

    2008-01-01

    BACKGROUND: Molecular probes are required to detect cell wall polymers in-situ to aid understanding of their cell biology and several studies have shown that cell wall epitopes have restricted occurrences across sections of plant organs indicating that cell wall structure is highly developmentally...... regulated. Xyloglucan is the major hemicellulose or cross-linking glycan of the primary cell walls of dicotyledons although little is known of its occurrence or functions in relation to cell development and cell wall microstructure. RESULTS: Using a neoglycoprotein approach, in which a XXXG heptasaccharide...... hapten inhibition of binding studies. The use of LM15 for the analysis of xyloglucan in the cell walls of tamarind and nasturtium seeds, in which xyloglucan occurs as a storage polysaccharide, indicated that the LM15 xyloglucan epitope occurs throughout the thickened cell walls of the tamarind seed and...

  15. Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

    Science.gov (United States)

    Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

    2016-02-01

    Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

  16. Walls shielding against ionizing radiation

    International Nuclear Information System (INIS)

    These specifications are to help the users of lead bricks as under DIN 25407, leaf 1, with the construction of walls shielding against ionizing radiation by examples for the uses of the different types of lead bricks and by recommendations for the construction of shielding walls and for the determination of the wall thickness necessary for shielding against γ-radiation as a function of energy. (orig./AK)

  17. Dynamics of monopole walls

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, R., E-mail: rafael.maldonado@durham.ac.uk; Ward, R.S., E-mail: richard.ward@durham.ac.uk

    2014-06-27

    The moduli space of centred Bogomolny–Prasad–Sommerfield 2-monopole fields is a 4-dimensional manifold M with a natural metric, and the geodesics on M correspond to slow-motion monopole dynamics. The best-known case is that of monopoles on R{sup 3}, where M is the Atiyah–Hitchin space. More recently, the case of monopoles periodic in one direction (monopole chains) was studied a few years ago. Our aim in this note is to investigate M for doubly-periodic fields, which may be visualized as monopole walls. We identify some of the geodesics on M as fixed-point sets of discrete symmetries, and interpret these in terms of monopole scattering and bound orbits, concentrating on novel features that arise as a consequence of the periodicity.

  18. Dynamics of monopole walls

    International Nuclear Information System (INIS)

    The moduli space of centred Bogomolny–Prasad–Sommerfield 2-monopole fields is a 4-dimensional manifold M with a natural metric, and the geodesics on M correspond to slow-motion monopole dynamics. The best-known case is that of monopoles on R3, where M is the Atiyah–Hitchin space. More recently, the case of monopoles periodic in one direction (monopole chains) was studied a few years ago. Our aim in this note is to investigate M for doubly-periodic fields, which may be visualized as monopole walls. We identify some of the geodesics on M as fixed-point sets of discrete symmetries, and interpret these in terms of monopole scattering and bound orbits, concentrating on novel features that arise as a consequence of the periodicity

  19. Dynamics of monopole walls

    CERN Document Server

    Maldonado, R

    2014-01-01

    The moduli space of centred Bogomolny-Prasad-Sommmerfield 2-monopole fields is a 4-dimensional manifold M with a natural metric, and the geodesics on M correspond to slow-motion monopole dynamics. The best-known case is that of monopoles on R^3, where M is the Atiyah-Hitchin space. More recently, the case of monopoles periodic in one direction (monopole chains) was studied a few years ago. Our aim in this note is to investigate M for doubly-periodic fields, which may be visualized as monopole walls. We identify some of the geodesics on M as fixed-point sets of discrete symmetries, and interpret these in terms of monopole scattering and bound orbits, concentrating on novel features that arise as a consequence of the periodicity.

  20. Great Wall of China

    Science.gov (United States)

    2001-01-01

    This ASTER sub-image covers a 12 x 12 km area in northern Shanxi Province, China, and was acquired January 9, 2001. The low sun angle, and light snow cover highlight a section of the Great Wall, visible as a black line running diagonally through the image from lower left to upper right. The Great Wall is over 2000 years old and was built over a period of 1000 years. Stretching 4500 miles from Korea to the Gobi Desert it was first built to protect China from marauders from the north.This image is located at 40.2 degrees north latitude and 112.8 degrees east longitude.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface

  1. Domain wall networks on solitons

    International Nuclear Information System (INIS)

    Domain wall networks on the surface of a soliton are studied in a simple theory. It consists of two complex scalar fields, in 3+1 dimensions, with a global U(1)xZn symmetry, where n>2. Solutions are computed numerically in which one of the fields forms a Q ball and the other field forms a network of domain walls localized on the surface of the Q ball. Examples are presented in which the domain walls lie along the edges of a spherical polyhedron, forming junctions at its vertices. It is explained why only a small restricted class of polyhedra can arise as domain wall networks

  2. Detection of ferromagnetic domain wall pinning and depinning with a semiconductor device

    Energy Technology Data Exchange (ETDEWEB)

    Malec, Chris E.; Bennett, Brian R.; Johnson, Mark B. [Naval Research Laboratory, Washington, D.C. 20375 (United States)

    2015-12-21

    We demonstrate the detection of a ferromagnetic domain wall using a nanoscale Hall cross. A narrow permalloy wire is defined lithographically on top of a Hall cross fabricated from an InAs quantum well. The width of the Hall cross (500 nm–1 μm) is similar to the width of the ferromagnetic wire (200–500 nm), and a geometric pinning site is fabricated in the ferromagnetic wire to trap a domain wall within the area of the Hall cross. The devices provide a signal that is often the same order of magnitude as the offset Hall voltage when a domain wall is located above the Hall cross, and may be useful for memory applications. Different geometries for the Hall cross and ferromagnetic wire are tested, and radiofrequency pulses are sent into the wire to demonstrate current driven domain wall motion. Further changes to the Hall bar geometry with respect to the wire geometry are investigated by numerical computation. A large gain in signal is seen for Hall bars only slightly wider than the ferromagnetic wires as compared to those twice as wide, as well as a larger sensitivity to the exact position of the domain wall with respect to the center of the Hall cross.

  3. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  4. Experimental and Numerical Analyses of New Massive Wooden Shear-Wall Systems

    Directory of Open Access Journals (Sweden)

    Luca Pozza

    2014-07-01

    Full Text Available Three innovative massive wooden shear-wall systems (Cross-Laminated-Glued Wall, Cross-Laminated-Stapled Wall, Layered Wall with dovetail inserts were tested and their structural behaviour under seismic action was assessed with numerical simulations. The wall specimens differ mainly in the method used to assemble the layers of timber boards composing them. Quasi-static cyclic loading tests were carried out and then reproduced with a non-linear numerical model calibrated on the test results to estimate the most appropriate behaviour factor for each system. Non-linear dynamic simulations of 15 artificially generated seismic shocks showed that these systems have good dissipative capacity when correctly designed and that they can be assigned to the medium ductility class of Eurocode 8. This work also shows the influence of deformations in wooden panels and base connectors on the behaviour factor and dissipative capacity of the system.

  5. A semi-discretized thin-walled beam element including distortion

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Jönsson, Jeppe

    2013-01-01

    An advanced thin-walled beam element including distortion of the cross section is presented. The formulation is based on a generalization of the classical Vlasov beam theory for analysis of open and closed thin-walled cross sections by including distortional displacements.The beam element...... formulation utilizes a semidiscretization approach in which the cross section is discretized into wall elements and the analytical solutions of the related GBT beam equations are used as displacement functions in the axial direction. Thus the beam element contains the semi-analytical solutions. In a number of...... related publications the authors have recently presented the semi-discretization approach and the analytical solution of the generalized beam equations. An illustrative example showing the validity and the accuracy of the developed distortional semi-discretized thin-walled beam element is given and it is...

  6. Dry wall Kras 2011

    Directory of Open Access Journals (Sweden)

    Domen Zupančič

    2012-01-01

    Full Text Available Despite the modesty of hiska, they show a simple understanding of corbelling technique. One could say they are all examples of human landscape cultivation. Although there is no evident common line when comparing all types of hiska, the cunning eye may observe one shared feature: the positioning of the entrance. More or less all the documented shelters have south or south-western facing entrances. The burja is a cold northerly wind; from the south (Adriatic Sea the winds are warmer. When resting, the setting sun is taken as a sign of the ending of the working day and a reward for the whole day’s efforts. Entrances are the only openings to these structures, and they should serve as well as possible - to watch over the crops, to wait when hunting, to enjoy the calm of evening light, to breathe the sea wind.The syntax of the architectural language of layering stone and shaping the pattern of the landscape remain an inventive realisation of spatial ideas from the past until today. Not only ideas of shaping space - these ideas are basic interventions in the natural habitat which contribute to survival. Culture and an awareness of its values are the origins of local development and reasonable heritage preservation. The next step are tutorial days with workshops on how to build dry stone structures, walls and other stone architecture, as the DSWA organisation in the UK is doing.

  7. Pharmacy without walls.

    Science.gov (United States)

    Shane, R R

    1996-02-15

    Attributes of excellence in pharmacy management are described: big-picture thinking, the ability to exploit change, and willingness to take risks. Big-picture thinking means understanding trends that are shaping health care in order to determine where pharmacy fits. Health systems look beyond inpatient care and use case managers to maximize resource use; pharmacists might serve as case managers. Managed care has caused physicians to be more receptive to resource-management strategies, such as clinical pathways; pharmacists can collaborate in the development of clinical pathways. Pharmacists can serve as physician extenders; for example, by conducting anticoagulation or hypertension clinics. Pharmacists need flexibility to adapt to changes in the internal organization of acute care institutions; they will need to learn about the clinical, behavioral, operational, and fiscal aspects of managing the total patient. New reporting relationships give pharmacists the opportunity to demonstrate to other members of the health care team their role in preventing, managing, and resolving drug-related problems throughout the continuum of care. Risk-taking can mean setting ambitious goals. By setting and achieving ambitious goals for products and services, pharmacists can raise patients' and other health care providers' expectations for pharmacy services. Pharmacists' success will depend on their willingness to experiment with new services and discard services that do not substantially advance patient care. Pharmacists must monitor changes in the provision of health care, determine the implications for their practice and seek opportunities for participation outside the walls within which they have traditionally practiced. PMID:8673664

  8. Numerical analysis of aerodynamic noise radiated from cross flow fan

    Institute of Scientific and Technical Information of China (English)

    Anbang CHEN; Song LI; Dongtao HUANG

    2008-01-01

    The flow field in a cross flow fan was simulated by solving the 2-D unsteady Reynolds-averaged Navier-Stokes equations. The calculated pressure fluctuations of the blades, the vortex wall, and the rear wall were then used as noise sources to calculate the sound field. The Ffowcs Williams-Hawkings (FW-H) equation was employed to predict the noise field caused by these sources. The predictions show that the rear wall and the vortex wall sources contribute significantly to the total noise and that both the predicted aerodynamic perform-ance and noise agree well with the experimental results.

  9. Thermal conductivity of multi-walled carbon nanotubes: Molecular dynamics simulations

    International Nuclear Information System (INIS)

    Heat conduction in single-walled carbon nanotubes (SWCNTs) has been investigated by using various methods, while less work has been focused on multi-walled carbon nanotubes (MWCNTs). The thermal conductivities of the double-walled carbon nanotubes (DWCNTs) with two different temperature control methods are studied by using molecular dynamics (MD) simulations. One case is that the heat baths (HBs) are imposed only on the outer wall, while the other is that the HBs are imposed on both the two walls. The results show that the ratio of the thermal conductivity of DWCNTs in the first case to that in the second case is inversely proportional to the ratio of the cross-sectional area of the DWCNT to that of its outer wall. In order to interpret the results and explore the heat conduction mechanisms, the inter-wall thermal transport of DWCNTs is simulated. Analyses of the temperature profiles of a DWCNT and its two walls in the two cases and the inter-wall thermal resistance show that in the first case heat is almost transported only along the outer wall, while in the second case a DWCNT behaves like parallel heat transport channels in which heat is transported along each wall independently. This gives a good explanation of our results and presents the heat conduction mechanisms of MWCNTs. (condensed matter: structural, mechanical, and thermal properties)

  10. Economics of abdominal wall reconstruction.

    Science.gov (United States)

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias. PMID:24035086

  11. Partial domain wall partition functions

    OpenAIRE

    Foda, O.; Wheeler, M.

    2012-01-01

    We consider six-vertex model configurations on an n-by-N lattice, n =< N, that satisfy a variation on domain wall boundary conditions that we define and call "partial domain wall boundary conditions". We obtain two expressions for the corresponding "partial domain wall partition function", as an (N-by-N)-determinant and as an (n-by-n)-determinant. The latter was first obtained by I Kostov. We show that the two determinants are equal, as expected from the fact that they are partition functions...

  12. Shock wave convergence in water with parabolic wall boundaries

    International Nuclear Information System (INIS)

    The convergence of shock waves in water, where the cross section of the boundaries between which the shock wave propagates is either straight or parabolic, was studied. The shock wave was generated by underwater electrical explosions of planar Cu wire arrays using a high-current generator with a peak output current of ∼45 kA and rise time of ∼80 ns. The boundaries of the walls between which the shock wave propagates were symmetric along the z axis, which is defined by the direction of the exploding wires. It was shown that with walls having a parabolic cross section, the shock waves converge faster and the pressure in the vicinity of the line of convergence, calculated by two-dimensional hydrodynamic simulations coupled with the equations of state of water and copper, is also larger

  13. Crossing Borders

    Directory of Open Access Journals (Sweden)

    Erik D. Barton, MD, MS, MBA

    2016-01-01

    Full Text Available As emergency physicians, we are privileged to be in a field that crosses more boundaries than any other medical specialty. It is a calling. Our skills are portable and transferable across cultural and geographic disparities. For these reasons, many of us are drawn to sharing our knowledge and training across the globe – towards treating patients in underserved and austere environments abroad. The rapid growth of international and global health educational initiatives across our U.S. residency training programs is a direct result of those undeniable forces. Additionally, inclusion of such rotations becomes a powerful resident recruitment tool as more and more of our trainees are looking for these opportunities during their formative years.

  14. Cross-field diode sputtering target assembly

    International Nuclear Information System (INIS)

    An improved cross-field diode sputtering target assembly adapted for sputtering a selected material having an ion target wherein a selected surface is formed of a selected material in a predetermined closed loop pattern having a central opening therein, and wherein the selected surface has spaced edges and is formed of a material adapted to be controllably eroded in a diode sputtering process, walls positioned contiguous or adjacent to each of the spaced edges of the selected surface wherein each of the walls extend substantially normal from and beyond each spaced edge of the selected surface of the ion target and a magnetic member having poles positioned in an opposed spaced relationship to each other and enclosing the walls and the ion target for providing a linear magnetic field through the walls, over the selected surface and through the ion target and wherein the magnetic member has a linear magnetic field of sufficient strength for plasma entrapment between the walls and over the selected surface wherein the selected surface is adapted to have an electric field applied thereacross at a direction substantially normal to the magnetic field to develop a BXE field and to entrap secondary electrons at the selected surface to control the erosion pattern thereof is shown. A method for utilizing the improved cross-field diode sputtering target assembly is also shown

  15. Biologic mesh for abdominal wall reconstruction

    Directory of Open Access Journals (Sweden)

    King KS

    2014-11-01

    Full Text Available Kathryn S King,1 Frank P Albino,2 Parag Bhanot3 1School of Medicine, Georgetown University Hospital, Washington, DC, USA; 2Department of Plastic Surgery, 3Department of General Surgery, Georgetown University Hospital, Washington, DC, USA Background: Mesh reinforcement significantly decreases rates of recurrence following ventral hernia repair. Historically, biologic mesh was touted as superior in the setting of infection; however, selecting the appropriate mesh for a given clinical scenario is often a matter of debate. The purpose of this review is to highlight a number of the more commonly used biologic mesh products with a review of outcomes from the current literature. Methods: Outcomes following abdominal wall reconstruction using biologic mesh were reviewed for acellular cadaveric human dermis, cross-linked porcine dermis, non-cross-linked porcine dermis, porcine small intestine submucosa, acellular bovine pericardial, and acellular bovine dermal mesh. Studies with rigorous methods, adequate patient samples, and sufficient follow-up were selected for review. Results: Hernia recurrence rates following biologic mesh reinforcement vary widely. Porcine small intestine submucosa and bovine pericardium were associated with the lowest hernia recurrence rates. Porcine cross-linked dermal mesh products resulted in higher rates of adhesion formation and lower rates of tissue incorporation compared to non-cross-linked porcine mesh. Conclusion: Successful ventral hernia repair can be achieved with acceptable complications rates for each of the reviewed mesh products. Biologic meshes have an advantage over synthetic mesh in contaminated wounds but their use may not be cost-effective in all patient populations. Those with and/or at high risk for wound complications may also undergo repair with biologic mesh. Keywords: biologic mesh, ventral hernia repair, acellular dermal matrix 

  16. Polymer mobility in cell walls of cucumber hypocotyls

    Science.gov (United States)

    Fenwick, K. M.; Apperley, D. C.; Cosgrove, D. J.; Jarvis, M. C.

    1999-01-01

    Cell walls were prepared from the growing region of cucumber (Cucumis sativus) hypocotyls and examined by solid-state 13C NMR spectroscopy, in both enzymically active and inactivated states. The rigidity of individual polymer segments within the hydrated cell walls was assessed from the proton magnetic relaxation parameter, T2, and from the kinetics of cross-polarisation from 1H to 13C. The microfibrils, including most of the xyloglucan in the cell wall, as well as cellulose, behaved as very rigid solids. A minor xyloglucan fraction, which may correspond to cross-links between microfibrils, shared a lower level of rigidity with some of the pectic galacturonan. Other pectins, including most of the galactan side-chain residues of rhamnogalacturonan I, were much more mobile and behaved in a manner intermediate between the solid and liquid states. The only difference observed between the enzymically active and inactive cell walls, was the loss of a highly mobile, methyl-esterified galacturonan fraction, as the result of pectinesterase activity.

  17. Acoustic Response of a Sinusoidally Perturbed Hard-Walled Duct

    OpenAIRE

    Silvio Del Giudice; Giancarlo Bernasconi

    2013-01-01

    Acoustic wave propagation in hard-walled ducts is of interest in many fields including vehicle design, musical instruments acoustics, and architectural and environmental noise-control. For the case of small sinusoidal perturbation of the cross-section, it is possible to derive simple though approximate analytical formulas of its plane wave acoustic reflection and transmission spectral response that resembles the optical situation of uniform Bragg gratings. The proof is given here, starting fr...

  18. Cell-wall hemicelluloses as mobile carbon stores in plants

    OpenAIRE

    Schädel, Christina

    2009-01-01

    Hemicelluloses are the second most abundant polysaccharide in nature after cellulose. So far, the chemical heterogeneity of cell-wall hemicelluloses and the relatively large sample-volume required in existing methods represent major obstacles for large-scale, cross-species analyses of this important plant compounds. Here, we apply a new micro-extraction method to analyse hemicelluloses and the ratio of ‘cellulose and lignin’ to hemicelluloses in different tissues of 28 plant species comprisin...

  19. Unquenched domain wall quarks with multi-bosons

    OpenAIRE

    Montvay, I.

    2002-01-01

    The numerical simulation of domain wall quarks with the two-step multi-boson (TSMB) algorithm is considered. The inclusion of single quark flavours, as required for strange quarks, is discussed. The usage of computer memory can be kept relatively low, independently of the order of polynomial approximations. Tests are performed with two flavours (N_f=2) of degenerate quarks near the N_t=4 thermodynamical cross over.

  20. Cell wall proteomics of crops

    OpenAIRE

    Komatsu, Setsuko; Yanagawa, Yuki

    2013-01-01

    Cell wall proteins play key roles in cell structure and metabolism, cell enlargement, signal transduction, responses to environmental stress, and many other physiological events. Agricultural crops are often used for investigating stress tolerance because cultivars with differing degrees of tolerance are available. Abiotic and biotic stress factors markedly influence the geographical distribution and yields of many crop species. Crop cell wall proteomics is of particular importance for improv...

  1. Experimental study on improvement effect of guide wall to water flow in bend of spillway chute.

    Science.gov (United States)

    Zhang, Qinghua; Diao, Yanfang; Zhai, Xingtao; Li, Shuning

    2016-01-01

    In order to improve water flow in a bend of a spillway chute using a guide wall, modeling experiments with or without a guide wall under conditions of three different bend axial radii, three chute bottom slopes and three flow rates were carried out in this study. Two indexes were calculated, which are the improved water surface uniformity and the reduced rate of water surface difference in concave and convex banks of the cross-section. The results show that: (1) setting a guide wall in a bend can improve water flow in the bend because it increased the water surface uniformity of the cross-section and reduced the water surface difference in the concave and convex banks; (2) the smaller the bend axial radius, the better the water surface improvement effect will be using a guide wall; (3) the steeper the bottom slope, the more cross-sections with less water surface difference; and (4) flow rates have a great influence on water surface improvement in the bend, and the guide wall can improve water flow obviously when the water depth in the starting section of the bend is lower than the height of the guide wall. This study has important implications in engineering design of guide walls. PMID:26877052

  2. Momentum balance in wall jets

    Science.gov (United States)

    Johansson, T. Gunnar; Mehdi, Faraz; Naughton, Jonathan W.

    2012-11-01

    A plane wall jet experiment has been done to study its momentum balance. Two component laser Doppler anemometry was used to simultaneously measure the axial and wall-normal velocity components in 6 axial positions (x/H= 25, 50, 75, 100, 125 and 150) spanning from the wall all the way well into the ambient stagnant area. In this way not only the mean velocity components and Reynolds normal and shear stresses but also all their spatial derivatives were determined. In addition the wall shear stress was measured in all six axial positions using oil film interferometry. From these data all terms in the x-momentum equation, except the pressure term, could be evaluated. Later also the pressure was measured in the same profiles, and thereby also the pressure term was included in the balance. Contrary to common belief it was found that the pressure was not constant in the wall jet. The complete momentum balance is discussed and used to evaluate the roles played by the different contributing terms in different regions of the flow field in an effort to improve on our understanding of the mechanics of wall jets.

  3. Orificing of water cross inlet in BWR fuel assembly

    International Nuclear Information System (INIS)

    A nuclear reactor fuel assembly is described comprising a bundle of elongated fuel rods disposed in side-by-side relationship so as to form an array of spaced fuel rods, a tubular flow channel member surrounding the fuel rods so as to direct flow of coolant/moderator fluid along the fuel rods, respective upper and lower tie plates at opposite ends of the fuel rods, and a hollow water cross having confronting side walls and a closed lower end wall at an inlet end. The water cross extends centrally through and disposed within the flow channel member so as to provide within the flow channel member separate compartments and to divide the bundle of fuel rods into mini-bundles being disposed in the respective compartments, the water cross including inlet cross flow means formed in the side walls near a lower end of the water cross above the closed end wall and near lower end portions of each of the mini-bundles of fuel rods, which inlet cross flow means provides both selected flow communication into the interior of the water cross and flow communication between the respective mini-bundles for minimizing maldistribution and equalizing flow

  4. DCB-adapted plant cells possess unique wall structure

    Energy Technology Data Exchange (ETDEWEB)

    Shedletzky, E.; Shmuel, M. (Hebrew Univ., Jerusalem (Israel)); Delmer, D. (Hebrew Univ., Jerusalem (Israel) Michigan State Univ., East Lansing (USA)); Lamport, D. (Michigan State Univ., East Lansing (USA))

    1990-05-01

    Suspension-cultured cells of tomato (Lycopersicon esculentum VF 36) haven been adapted to growth on high concentrations of 2,6-dichloro-benzonitrile (DCB), an herbicide which inhibits cellulose biosynthesis. The mechanism of adaptation appears to rest largely on the ability of thee cells to divide and expand in the virtual absence of a cellulose-xyloglucan network. Walls of adapted cells growing on DCB also differ from non-adapted cells by having reduced levels of hydroxyproline in protein, both in bound and salt-elutable form, and in having a much higher proportion of homogalacturonon and rhamnogalacturonan-like polymers. Most of these latter polymers are apparently cross-linked in the wall via phenolic-esters and/or phenolic ether linkages, and these polymers appear to represent the major load-bearing network in thee unusual cell walls. The surprising finding that plant cells can survive in the virtual absence of a major load-bearing network in their primary cell walls indicates that plants possess remarkable flexibility for tolerating changes in wall composition.

  5. FORCES ON A NEAR-WALL CIRCULAR CYLINDER

    Institute of Scientific and Technical Information of China (English)

    ZHAN Jing-xia; WANG Jin-jun; ZHANG Pang-feng

    2004-01-01

    The pressure distribution around a near-wall smooth circular cylinder in cross-flow was mainly investigated. The experiment was conducted at the sub-critical Reynolds number ranging from 2.24·104 to 8.94·104,at which the regular vortex separation exists on an isolated circular cylinder. The experimental results indicate that the forces on a circular cylinder near a plane wall are different from those on an isolated circular cylinder. Drag and lift coefficients of a near-wall circular cylinder strongly depend on gap ratio. The increase of gap ratio results in the increase of drag coefficient and the declination of lift coefficient, drag coefficient ranges from 0.5 to 1.0, and lift coefficient from 0.25 to 0 when gap ratio gradually increases from 0 to 1.0, and then the forces tend to be nearly constant with the increase of gap ratio. The attraction between a cylinder and a plane wall, i.e., downward force, occurs when gap ratio lies in certain range. The existence of cylinder changes the pressure gradient on the plane wall, and the influence extends to the location where x/D<-3.0 and x/D>5.0.

  6. WallProtDB, a database resource for plant cell wall proteomics

    OpenAIRE

    San Clemente, Hélène; Jamet, Elisabeth

    2015-01-01

    Background During the last fifteen years, cell wall proteomics has become a major research field with the publication of more than 50 articles describing plant cell wall proteomes. The WallProtDB database has been designed as a tool to facilitate the inventory, the interpretation of cell wall proteomics data and the comparisons between cell wall proteomes. Results WallProtDB (http://www.polebio.lrsv.ups-tlse.fr/WallProtDB/) presently contains 2170 proteins and ESTs identified experimentally i...

  7. MHD Electrode and wall constructions

    Science.gov (United States)

    Way, Stewart; Lempert, Joseph

    1984-01-01

    Electrode and wall constructions for the walls of a channel transmitting the hot plasma in a magnetohydrodynamic generator. The electrodes and walls are made of a plurality of similar modules which are spaced from one another along the channel. The electrodes can be metallic or ceramic, and each module includes one or more electrodes which are exposed to the plasma and a metallic cooling bar which is spaced from the plasma and which has passages through which a cooling fluid flows to remove heat transmitted from the electrode to the cooling bar. Each electrode module is spaced from and electrically insulated from each adjacent module while interconnected by the cooling fluid which serially flows among selected modules. A wall module includes an electrically insulating ceramic body exposed to the plasma and affixed, preferably by mechanical clips or by brazing, to a metallic cooling bar spaced from the plasma and having cooling fluid passages. Each wall module is, similar to the electrode modules, electrically insulated from the adjacent modules and serially interconnected to other modules by the cooling fluid.

  8. Functional domain walls in multiferroics

    Science.gov (United States)

    Meier, Dennis

    2015-11-01

    During the last decade a wide variety of novel and fascinating correlation phenomena has been discovered at domain walls in multiferroic bulk systems, ranging from unusual electronic conductance to inseparably entangled spin and charge degrees of freedom. The domain walls represent quasi-2D functional objects that can be induced, positioned, and erased on demand, bearing considerable technological potential for future nanoelectronics. Most of the challenges that remain to be solved before turning related device paradigms into reality, however, still fall in the field of fundamental condensed matter physics and materials science. In this topical review seminal experimental findings gained on electric and magnetic domain walls in multiferroic bulk materials are addressed. A special focus is put on the physical properties that emerge at so-called charged domain walls and the added functionality that arises from coexisting magnetic order. The research presented in this review highlights that we are just entering a whole new world of intriguing nanoscale physics that is yet to be explored in all its details. The goal is to draw attention to the persistent challenges and identify future key directions for the research on functional domain walls in multiferroics.

  9. The feasibility of removable prefab diaphragm walls

    NARCIS (Netherlands)

    Amaarouk, R.; De Gijt, J.G.; Braam, C.R.

    2013-01-01

    A diaphragm wall is a cast in-situ reinforced concrete retaining wall applied in, among others, quay walls. The main advantages of this type of retaining wall are that it can be made in almost every preferred length and that it can resist high structural loads. However, there are several disadvantag

  10. Turbine airfoil with outer wall thickness indicators

    Science.gov (United States)

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  11. Shielding walls against ionizing radiation

    International Nuclear Information System (INIS)

    The standard contains specifications for the shape and requirements set for lead bricks such that they can be used to construct radiation-shielding walls according to the building kit system. The dimensions of the bricks are selected in such a way as to permit any modification of the length, height and thickness of said shielding walls in units of 50 mm. The narrow side of the lead bricks juxtaposed to one another in a wall construction to shield against radiation have to form prismatic grooves and tongues; in this way, direct penetration by radiation is prevented. Only cuboid bricks (serial nos. 55-60 according to Table 10) do not have prismatic tongues and grooves. (orig.)

  12. Magnetic domain-wall velocity enhancement induced by a transverse magnetic field

    OpenAIRE

    Yang, Jusang; Beach, Geoffrey S. D.; Knutson, Carl; Erskine, James L.

    2011-01-01

    Spin dynamics of field-driven domain walls (DWs) guided by Permalloy nanowires are studied by high-speed magneto-optic polarimetry and numerical simulations. DW velocities and spin configurations are determined as functions of longitudinal drive field, transverse bias field, and nanowire width. Nanowires having cross-sectional dimensions large enough to support vortex wall structures exhibit regions of drive-field strength (at zero bias field) that have enhanced DW velocity resulting from cou...

  13. Determinations of effective heat transport coefficients for wall-cooled packed beds

    OpenAIRE

    Borkink, J.G.H.; Westerterp, K.R.

    1992-01-01

    The influence is studied of several assumptions, often made in literature, on the values for the effective radial heat conductivity, wall heat transfer coefficient and overall heat transfer coefficient, as obtained from experiments in wall-cooled packed beds without a chemical reaction. Especially the choice of the inlet boundary condition can have a large impact on the values obtained. The influence of the presence of a radial velocity profile and also the cross-correlation of the parameters...

  14. Chest Wall tumor: combined management

    International Nuclear Information System (INIS)

    Cancer is relatively rare disease among children and adolescents. The incidence of solid tumors other than CNS is less than 2/100,000. Tumors of the chest wall can arise either from the somatic tissue or ribs. These are rare, so either institutional reviews or multi institutional studies should determine optimal therapeutic management. Of the bony chest wall, Ewing's sarcoma or the family of tumor (peripheral neuro epithelioma, Askin tumor), are the most common. These lesions are lytic and have associated large extra pleural component. This large extra pleural component often necessitates major chest wall resection (3 or more ribs), and when lower ribs are involved, this entails resection of portion of diaphragm. Despite this resection, survival in the early 1970 was 10-20%. Since 1970 multi agent chemotherapy has increased survival rates. of importance, however, is these regimens have caused significant reduction of these extra pleural components so that major chest wall resections have become a rarity. With improved survival and decreased morbidity preoperative chemotherapy followed by surgery is now the accepted modality of treatment. Another major advantage of this regimen is that potential radiation therapy may be obviated. The most common chest wall lesion is rhabdomyosarcoma. In the IRS study of 1620 RMS patients, in 141 (9%) the primary lesion was in the chest wall. these are primarily alveolar histology. when lesions were superficial, wide local excision with supplemental radiation therapy was associated with low morbidity and good overall survival. however, a majority have significant intra- thoracic components. in these circumstances the resectability rate is less than 30% and the survival poor. Other lesions include non rhabdomyosarcomas, eosinophilic granuloma, chondrosarcoma, and osteomyelitis. The management of these lesions varies according to extent, histology, and patient characteristics

  15. Lymphomas presenting as chest wall tumors

    OpenAIRE

    Witte, Biruta; Hürtgen, Martin

    2006-01-01

    Four cases of thoracic lymphoma mimicking chest wall tumors are presented. As resection is not the treatment of first choice in lymphomas, pretherapeutical evaluation of chest wall tumors should include a thoroughly staging and a biopsy for histopathological diagnosis. Chest wall destruction due to an anterior mediastinal mass, or a chest wall tumor associated with mediastinal lymph node enlargement, could be suspicious of thoracic lymphoma. Lymphoma with chest wall involvement mostly turns o...

  16. Domain wall description of superconductivity

    International Nuclear Information System (INIS)

    In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted through the fact that the soliton following accelerating orbits is a Rindler observer experiencing a thermal bath

  17. Wave Forces on Crown Walls

    DEFF Research Database (Denmark)

    Pedersen, Jan; Burcharth, H. F.

    1993-01-01

    This paper presents some of the results from a large parametric laboratory study including more than 200 long-duration model tests. The study addresses both the wave forces imposed on the breakwater crown wall as well as the performance of the structure in reducing the wave overtopping. The testing...... programme includes variations of the sea state parameters and of the geometrical configuration of the breakwater and crown wall. Basic relations between forces/overtopping and the varied parameters are examined and preliminary design guidelines for structures within the tested range of variations are...

  18. Glazing and the Trombe wall

    Energy Technology Data Exchange (ETDEWEB)

    Pouder, R W; Leigh, R W

    1978-01-01

    Single, double and triple glazing are examined for use in passive solar Trombe walls and south facing windows. Net gains and losses are calculated employing regional weather data and annual contribution to heating load reduction is evaluated. The study concentrates on the reflectivity of each glass pane, including the dependence of reflectivity on the angle of incidence of the radiation, and resulting heat gains and losses. This facet of passive design heretofore has been inadequately treated as is shown to be significant. The marginal value of each additional pane is investigated with regard to heat gain, energy savings and total costs. Additionally, attention is given to the effects of Trombe wall energy storage.

  19. Shielding walls against ionizing radiation

    International Nuclear Information System (INIS)

    This standard shall be applied to closed shielding facilities which, together with the lead bricks according to DIN 25 407 part 1 and the functional elements according to this standard, are designed to make possible the setting-up of complete shieldings for hot cells in beta-gamma-technique (see DIN 25 407 part 3) according to modular principles. This standard is intended to facilitate the design and construction of hot cells with shielding walls made of lead as well as the interchangeability of individual constructional elements in existing shielding walls. (orig./HP)

  20. Scientific Opinion on application (EFSA-GMO-NL-2009-64 for the placing on the market of herbicide-tolerant genetically modified soybean BPS-CV127-9 for food and feed uses, import and processing under Regulation (EC No 1829/2003 from BASF Plant Science

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Genetically Modified Organisms (GMO

    2014-01-01

    Full Text Available Soybean BPS-CV127-9 contains a single insertion locus of the csr1-2 gene. Stability of the genetic modification was demonstrated. The expression of the acetohydroxyacid synthase large sub-unit from Arabidopsis thaliana, conferring tolerance to imidazolinone herbicides, was sufficiently analysed. Bioinformatic analyses did not raise safety issues. No differences were identified in the seed composition that would require further assessment with regard to safety. Regarding agronomic and phenotypic characteristics, a difference in seed weight was identified; however, this difference does not affect the overall safety of this soybean. Although the EFSA GMO Panel cannot conclude on its forage composition, soybean forage is not expected to be imported in significant amount for feed uses. Safety assessment identified no concerns regarding the potential toxicity and allergenicity of the newly expressed proteins or soybean BPS-CV127-9. Compositional data indicating that soybean BPS-CV127-9 is as nutritious as non-GM soybean varieties were supported by the outcome of a chicken feeding study. There are no indications of an increased likelihood of spread and establishment of feral soybean BPS-CV127-9 plants, unless they are exposed to imidazolinone-containing herbicides. Risks associated with an unlikely, but theoretically possible, horizontal transfer of recombinant genes from soybean BPS-CV127-9 to bacteria have not been identified. Considering the scope of this application, interactions with the biotic and abiotic environment are not considered to be a relevant issue. The post-market environmental monitoring plan and reporting intervals are in line with the scope of this application. In conclusion, the EFSA GMO Panel considers that the information available for soybean BPS‑CV127-9 addresses scientific comments raised by Member States and that the soybean BPS-CV127-9, as described in this application, is as safe and nutritious as its conventional

  1. Monte-Carlo studies of radiation damage in the first wall caused by fusion neutron

    International Nuclear Information System (INIS)

    The Monte-Carlo Neutron Transport Program and Neutron Radiation Damage Program are presented for studying radiation damage in the First Wall. The programs are used to static multi-component amorphous target. With the average wall load 1 MW/m2, the following calculating results for EHR first wall (type 316 stainless steel) have been performed by using designed neutron spectrums at EHR first wall: the PKA energy spectrums (30 eV to 1 MeV), average displacement per atom rate (20.6 dpa/a) and average helium and hydrogen production rates (247.18 appm/a and 721.15 appm/a). It shows that Hybrid Reactor's radiation damage is more serious than pure Fusion reactor's by comparison of above results and EHP's calculated results in the same wall load. the cross-section data from MC (87) n library is used in the calculation

  2. Border Crossing/Entry Data - Boarder Crossing

    Data.gov (United States)

    Department of Transportation — Border Crossing/Entry Data provides summary statistics for incoming crossings at the U.S.-Canadian and the U.S.-Mexican border at the port level. Data are available...

  3. Far SOL transport and main wall plasma interaction in DIII-D

    International Nuclear Information System (INIS)

    Far scrape-off layer (SOL) and near-wall plasma parameters in DIII-D depend strongly on the discharge parameters and confinement regime. In L-mode discharges cross-field transport increases with the average discharge density and flattens far SOL profiles, thus increasing plasma-wall contact. In H-mode between edge localized modes (ELMs), plasma-wall contact is generally weaker than in L-mode. During ELMs plasma fluxes to the wall increase to, or above the L-mode levels. Depending on the discharge conditions ELMs are responsible for 30-90% of the ion flux to the outboard chamber wall. Cross-field fluxes in far SOL are dominated by large amplitude intermittent transport events that may propagate all the way to the outer wall and cause sputtering. A Divertor Material Evaluation System (DiMES) probe containing samples of several ITER-relevant materials including carbon, beryllium and tungsten was exposed to a series of upper single null (USN) discharges as a proxy to measure the first wall erosion. (author)

  4. Analytic form of transverse head-to-head domain walls in thin cylindrical wires

    Energy Technology Data Exchange (ETDEWEB)

    Hertel, Riccardo, E-mail: hertel@ipcms.unistra.fr [Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504, Strasbourg (France); Kákay, Attila [Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich GmbH, D-52428 Jülich (Germany)

    2015-04-01

    The static problem of a one-dimensional, transverse head-to-head domain wall structure in a thin soft-magnetic nanowire with circular cross-section is treated within the framework of micromagnetic theory. An analytic form of the domain wall profile is derived, which yields that the domain wall profile depends on the wire radius. The analysis is performed by decomposing the magnetostatic energy into a monopolar and a dipolar term. We present a model in which the dipolar term of the magnetostatic energy resulting from the transverse magnetization in the center of the domain wall is calculated with Osborn's formulas for homogeneously magnetized ellipsoids [Phys. Rev. 67 (1945) 351] [22]. The analytic results agree almost perfectly with simulation data as long as the wire diameter is sufficiently small to prevent inhomogeneities of the magnetization along the cross-section. Owing to the recently demonstrated negligible Döring mass of these walls, our results should also apply to the dynamic case, where domain walls are driven by spin-transfer toque effects and/or an axial magnetic field. - Highlights: • Diameter-dependent analytic form of transverse domain walls in soft-magnetic nanowires. • Magnetostatic model based on the demagnetizing factors of oblate and prolate spheroids. • Calibration of the model with micromagnetic simulations. • Excellent agreement between analytic form and numerical results. • Linearization of the equations for simple, approximate solutions.

  5. A new high-resolution spectral approach to noninvasively evaluate wall deformations in arteries.

    Science.gov (United States)

    Bazan, Ivonne; Negreira, Carlos; Ramos, Antonio; Brum, Javier; Ramirez, Alfredo

    2014-01-01

    By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and "in vitro" carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime. PMID:24688596

  6. A New High-Resolution Spectral Approach to Noninvasively Evaluate Wall Deformations in Arteries

    Directory of Open Access Journals (Sweden)

    Ivonne Bazan

    2014-01-01

    Full Text Available By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and “in vitro” carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime.

  7. Retrofitting Systems for External Walls

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report, 9 different external and internal retrofitting systems are analyzed using numerical calculations. The analysis focuses on the thermal bridge effects in the different systems, and on this basis it is discussed whether internal or external retrofitting has the most advantages. The...... different systems are evaluated using 5 different types of existing walls....

  8. Solar Walls for concrete renovation

    DEFF Research Database (Denmark)

    Gramkow, Lotte; Vejen, Niels Kristian; Olsen, Lars;

    1996-01-01

    This repport gives a short presentation of three full-scale testing solar walls, the construction including the architectural design, materials and components, transportation and storage of solar enegy, the effect on the construction behind, statics and practical experience.The results of the...... measurments (energy- and temperature conditions, airchange-, termovisions- and moist measurments), operation- and user experience from the three buildings are describet....

  9. Wary Eyes Monitoring Wall Street

    Science.gov (United States)

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  10. Partial domain wall partition functions

    CERN Document Server

    Foda, O

    2012-01-01

    We consider six-vertex model configurations on a rectangular lattice with n (N) horizontal (vertical) lines, and "partial domain wall boundary conditions" defined as 1. all 2n arrows on the left and right boundaries point inwards, 2. n_u (n_l) arrows on the upper (lower) boundary, such that n_u + n_l = N - n, also point inwards, 3. all remaining n+N arrows on the upper and lower boundaries point outwards, and 4. all spin configurations on the upper and lower boundaries are summed over. To generate (n-by-N) "partial domain wall configurations", one can start from A. (N-by-N) configurations with domain wall boundary conditions and delete n_u (n_l) upper (lower) horizontal lines, or B. (2n-by-N) configurations that represent the scalar product of an n-magnon Bethe eigenstate and an n-magnon generic state on an N-site spin-1/2 chain, and delete the n lines that represent the Bethe eigenstate. The corresponding "partial domain wall partition function" is computed in construction {A} ({B}) as an N-by-N (n-by-n) det...

  11. Dynamics of domain wall networks

    International Nuclear Information System (INIS)

    Networks or webs of domain walls are admitted in Abelian or non-Abelian gauge theory coupled to fundamental Higgs fields with complex masses. We examine the dynamics of the domain wall loops by using the moduli approximation and find a phase rotation induces a repulsive force which can be understood as a Noether charge of Q-solitons. Non-Abelian gauge theory allows different types of loops which can be deformed to each other by changing a modulus. This admits the moduli geometry like a sandglass made by gluing the tips of the two cigar-(cone-)like metrics of a single triangle loop. We conclude that the sizes of all loops tend to grow for a late time in general models with complex Higgs masses, while the sizes are stabilized at some values once triplet masses are introduced for the Higgs fields. We also show that the stationary motion on the moduli space of the domain wall webs represents 1/4 Bogomol'nyi-Prasad-Sommerfield Q-webs of walls

  12. New Bricks in the Wall

    Institute of Scientific and Technical Information of China (English)

    RONG JIAOJIAO

    2007-01-01

    @@ Whenever a newcomer enters the classroom, he points at the wall. "Look at that!" says Li Shunye, indicating a picture of something that looks a bit like a pink furry fox, only with an oversized tail. "It's a squirrel," says the 9-year-old. "I made it."

  13. PPOOLEX experiments on wall condensation

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    This report summarizes the results of the wall condensation experiments carried out in December 2008 and January 2009 with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a DN200 blowdown pipe to the condensation pool. Altogether five experiments, each consisting of several blows, were carried out. The main purpose of the experiment series was to study wall condensation phenomenon inside the dry well compartment while steam is discharged through it into the condensation pool and to produce comparison data for CFD calculations at VTT. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. For the wall condensation experiments the test facility was equipped with a system for collecting and measuring the amount of condensate from four different wall segments of the dry well compartment. A thermo graphic camera was used in a couple of experiments for filming the outside surface of the dry well wall. The effect of the initial temperature level of the dry well structures and of the steam flow rate for the accumulation of condensate was studied. The initial temperature level of the dry well structures varied from 23 to 99 deg. C. The steam flow rate varied from 90 to 690 g/s and the temperature of incoming steam from 115 to 160 deg. C. During the initial phase of steam discharge the accumulation of condensate was strongly controlled by the temperature level of the dry well structures; the lower the initial temperature level was the more condensate was accumulated. As the dry well structural temperatures increased the condensation process slowed down. Most of the condensate usually accumulated during the first 200 seconds of the discharge. However, the condensation process never completely stopped because a small temperature difference remained between the dry well atmosphere and inner wall

  14. Steel-framed buildings: Impacts of wall detail configurations on the whole wall thermal performance

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, J.; Desjarlais, A.O.; Christian, J.E.

    1998-06-01

    The main objective of this paper is the influence of architectural wall details on the whole wall thermal performance. Whole wall thermal performance analysis was performed for six light gage steel-framed wall systems (some with wood components). For each wall system, all wall details were simulated using calibrated 3-D finite difference computer modeling. The thermal performance of the six steel-framed wall systems included various system details and the whole wall system thermal performance for a typical single-story ranch house. Currently, predicted heat losses through building walls are typically based on measurements of the wall system clear wall area using test methods such as ASTM C 236 or are calculated by one of the procedures recommended in the ASHRAE Handbook of Fundamentals that often is carried out for the clear wall area exclusively. In this paper, clear wall area is defined as the part of the wall system that is free of thermal anomalies due to building envelope details or thermally unaffected by intersections with other surfaces of the building envelope. Clear wall experiments or calculations normally do not include the effects of building envelope details such as corners, window and door openings, and structural intersections with roofs, floors, ceilings, and other walls. In steel-framed wall systems, these details typically consist of much more structural components than the clear wall. For this situation, the thermal properties measured or calculated for the clear wall area do not adequately represent the total wall system thermal performance. Factors that would impact the ability of today`s standard practice to accurately predict the total wall system thermal performance are the accuracy of the calculation methods, the area of the total wall that is clear wall, and the quantity and thermal performance of the various wall system details.

  15. Through-the-wall radar imaging

    CERN Document Server

    Amin, Moeness G

    2011-01-01

    Wall Attenuation and Dispersion, A. Hussein Muqaibel, M.A. Alsunaidi, Nuruddeen M. Iya, and A. Safaai-JaziAntenna Elements, Arrays, and Systems for Through-the-Wall Radar Imaging, A. Hoorfar and A. FathyBeamforming for Through-the-Wall Radar Imaging, G. Alli and D. DiFilippoImage and Localization of Behind-the-Wall Targets Using Collocated and Distributed Apertures, Y.D. Zhang and A. HuntConventional and Emerging Waveforms for Detection and Imaging of Targets behind Walls, F. Ahmad and R.M. NarayananInverse Scattering Approaches in Through-the-Wall Imaging, K. Sarabandi, M. Thiel, M. Dehmollai

  16. Sonographic Findings of Variable Chest Wall Disorders

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Mi Suk; Kim, Ji Young; Cho, Woo Ho; Kim, Joung Sook; Jeong, Myeong Ja; Kim, Soung Hee; Kim, Jae Hyung; Kim, Soo Hyun; Jun, Woo Sun [Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    Variable chest wall disorders include hemorrhage, inflammation and a tumor on the chest wall. Especially in females, abnormal anterior chest wall findings can appear as breast lesions due to the anatomic relationship between the chest wall and the breast. Sonography is the first diagnostic tool to utilize for chest wall disorders and has an important role for the differential diagnosis. In this study, we introduce sonographic findings of the various chest wall disorders that are discovered incidentally during an examination for a palpable mass or pain in the breast. We also describe sonographic findings that additionally performed of sonography-guided core needle biopsy

  17. WALL-E. Humanamente tecnológicos

    OpenAIRE

    Madrid Brito, Débora

    2014-01-01

    [ES] El cine de animación ha planteado en numerosas ocasiones los conflictos que ha generado la relación entre el hombre y el desarrollo tecnológico y científico. En el caso de Wall-E se aprecia un llamativo cambio de roles entre humanos y robots. La película propone, a través de las relaciones de sus personajes y su argumento, una reflexión en torno a la necesidad de la técnica para la evolución humana. Este artículo, a partir de la descripción e interpretación de algunos elementos clave de ...

  18. Wall conditioning of JET with the ITER-Like Wall

    Science.gov (United States)

    Douai, D.; Brezinsek, S.; Esser, H. G.; Joffrin, E.; Keenan, T.; Knipe, S.; Kogut, D.; Lomas, P. J.; Marsen, S.; Nunes, I.; Philipps, V.; Pitts, R. A.; Shimada, M.; de Vries, P.; JET EFDA Contributors

    2013-07-01

    The initial conditioning cycle of JET ILW is analysed and compared with restart and operation in 2008 with a carbon dominated wall. Comparable water and oxygen decay times are observed during bake-out in both cases. Despite a 2 × 10-3 mbar l/s leak rate during plasma operation, no further wall conditioning has been necessary after plasma restart in ILW, which dramatically contrasts with 2008. Plasma O content is lower with the ILW. Higher O levels are measured after nights or week-ends, BeO layers being formed and re-eroded, but do not impact plasma operation and performance. First results on isotopic wall changeover by GDC on the ILW six months of the first D2 campaign evidence a reservoir of about 3 × 1022 atoms, i.e. ten time lower than in carbon PFCs. A study in JET of the glow discharge current distribution for different ratios of the ionization mean free paths to the vessel dimensions seems to indicate sufficient toroidal and poloidal homogeneity in ITER.

  19. The design of a 316 stainless steel first wall for a pulsed fusion reactor with wall loading greater than 10 MWm-2

    International Nuclear Information System (INIS)

    A preliminary design study has been made of a 316 stainless steel first wall for a fusion reactor operating at a neutron wall loading of about 10 MWm-2 and a burn cycle of about 1000 seconds. The study highlights the conflicting requirements of providing sacrificial material to withstand erosion whilst limiting the cyclic thermal stresses to give adequate fatigue life. The analysis is based on the ASME boiler and pressure vessel code Section III, particularly the high temperature code case N47. The merits of helium and water cooling are compared and it is found that the high cyclic wall loading strongly favours water cooling. The maximum life of the first wall is governed by the erosion rate of the front surface and the fatigue characteristics of the material. The first wall geometry analysed consisted of parallel plain tubes arranged in an overlapping array. The relative disadvantages of other cross-sectional forms and of membrane wall layouts are discussed. A review is given of the possible advantages of different tube materials and identifies engineering aspects of the first wall design problem that would benefit from further investigation. (author)

  20. Scientific Opinion on application (EFSA-GMO-NL-2009-64) for the placing on the market of herbicide-tolerant genetically modified soybean BPS-CV127-9 for food and feed uses, import and processing under Regulation (EC) No 1829/2003 from BASF Plant Science

    OpenAIRE

    EFSA Panel on Genetically Modified Organisms (GMO)

    2014-01-01

    Soybean BPS-CV127-9 contains a single insertion locus of the csr1-2 gene. Stability of the genetic modification was demonstrated. The expression of the acetohydroxyacid synthase large sub-unit from Arabidopsis thaliana, conferring tolerance to imidazolinone herbicides, was sufficiently analysed. Bioinformatic analyses did not raise safety issues. No differences were identified in the seed composition that would require further assessment with regard to safety. Regarding agronomic and phenotyp...

  1. Distortional Mechanics of Thin-Walled Structural Elements

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim

    number of degrees of freedom. This means that the classical Vlasov thin-walled beam theory for open and closed cross sections is generalized as part of a semi-discretization process by including distortional displacement fields. A novel finite-element-based displacement approach is used in combination...... homogeneous and non-homogeneous differential equations and the related solutions. The developed semi-discretization approach to Generalized Beam Theory (GBT) is furthermore extended to include the geometrical stiffness terms for column buckling analysis based on an initial stress approach. Through variations......-section displacement mode shapes and buckling load factor are given. In order to handle arbitrary boundary conditions as well as the possibility to add concentrated loads as nodal loads the formulation of a generalized onedimensional semi-discretized thin-walled beam element including distortional contributions is...

  2. Microscopic elasticity imaging of vessel walls based on intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    WAN Mingxi; WANG Supin; CUI Yaoyao; LI Junbo; LI Yangmei

    2002-01-01

    The effect of the transducer eccentricity on grayscales of intravascualr ultrasoundimages was corrected based on the scattering properties of high frequency ultrasound in vesselwalls. The displacement and strain distributions of vessel walls produced by tissue microele-ment motion were obtained using a novel motion estimation method in steps and sum basedon the optical flow and genetic algorithm. Furthermore, authors firstly reconstructed "real"elasticity distribution images of cross section tissues of vessel walls in the world. In vitroexperimental results of porcine artery demonstrated the methods mentioned above are reason-able. Experimental investigation of vascular mechanics can be advanced to 2D sub-millimetermicrostructure levels. These studies have potential to provide new technology means in moni-toting and evaluation of Percutaneous transluminal coronary angioplasty process.

  3. Wall correction model for wind tunnels with open test section

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; Shen, Wen Zhong; Mikkelsen, Robert Flemming

    2006-01-01

    In the paper we present a correction model for wall interference on rotors of wind turbines or propellers in wind tunnels. The model, which is based on a one-dimensional momentum approach, is validated against results from CFD computations using a generalized actuator disc principle. In the model...... the exchange of axial momentum between the tunnel and the ambient room is represented by a simple formula, derived from actuator disc computations. The correction model is validated against Navier-Stokes computations of the flow about a wind turbine rotor. Generally, the corrections from the model are...... in very good agreement with the CFD computations, demonstrating that one-dimensional momentum theory is a reliable way of predicting corrections for wall interference in wind tunnels with closed as well as open cross sections....

  4. Experimental and numerical study of heat transfer across insulation wall of a refrigerated integral panel van

    International Nuclear Information System (INIS)

    This paper presents an experimental and numerical design study of an insulation wall for refrigerated vans. The thermophysical properties of the insulating multilayer panel, the external environment impact (solar irradiation, temperature, etc.) and durability are taken into account. Different tools are used to characterize the thermal performances of the insulation walls and the thermal properties of the insulation materials are measured. In addition, an experiment at the wall scale is carried out and a 2D FEM model of heat and mass transfer within the wall is formulated. Three configurations are studied with this design approach. Multilayer insulation walls containing reflective multi-foil insulation, aerogel and phase change materials (PCM) are tested. Promising results are obtained with these materials, especially the reduction of peak heat transfer and energy consumption during the daytime period. Furthermore, the major influence of solar irradiation is highlighted as it can increase the peak heat transfer crossing the insulation wall by up to 43%. Nevertheless, we showed that the use of reflective multi-foil insulation and aerogel layers allowed decreasing this impact by 27%. - Highlights: • A design study of an insulation wall for a refrigerated van is carried out. • Experimental and numerical studies of multilayer insulation walls are performed. • The major influence of solar irradiation is highlighted. • New insulation materials (reflective multi-foil, aerogel and PCM) are tested

  5. Brick walls on the brane

    International Nuclear Information System (INIS)

    The so-called 'brick-wall model' is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified

  6. Domain walls at finite temperature

    International Nuclear Information System (INIS)

    It is suggested that the phase transition of lambda phi 4 theory as a function of temperature coincides with the spontaneous appearance of domain walls. Based on one-loop calculations, T sub(c) = 4M/√ lambda is estimated as the temperature for these domains to because energetically favored, to be compared with T sub(c) = 4.9M/√ lambda from effective potential calculations (which are performed directly in the broken phase). Domain walls, as well as other Types of fluctuations, disorder the system above T sub(c), leading to =0. The critical exponent for the specific heat above T sub(c) is computed; and α=2/3 + 0 (√ lambda) is obtained. (Author)

  7. Actinomycosis involving the chest wall: CT findings

    International Nuclear Information System (INIS)

    Two cases of pulmonary actinomycosis with extension to involve the chest wall that were evaluated using computerized tomography are reported. In both cases, the relation of pulmonary and chest wall disease was best shown using CT

  8. Thermal insulation properties of walls

    OpenAIRE

    Zhukov Aleksey Dmitrievich; Bessonov Igor' Vyacheslavovich; Sapelin Andrey Nikolaevich; Bobrova Ekaterina Yur'evna

    2014-01-01

    Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the...

  9. Quantitative optical imaging of single-walled carbon nanotubes

    Science.gov (United States)

    Herman, Lihong H.

    The development and application of optical imaging tools and probing techniques have been the subject of exciting research. These tools and techniques allow for non-invasive, simple sample preparation and relatively fast measurement of electronic and optical properties. They also provided crucial information on optoelectronic device application and development. As the field of nanostructure research emerged, they were modified and employed to understand various properties of these structures at the diffraction limit of light. Carbon nanotubes, up to hundreds of micrometers long and several nanometers thin, are perfect for testing and demonstrating newly-developed optical measurement platforms for individual nanostructures, due to their heterogeneous nature. By employing two quantitative imaging techniques, wide-field on-chip Rayleigh scattering spectroscopy and spatial modulation confocal absorption microscopy, we investigate the optical properties of single-walled carbon nanotubes. These techniques allow us to obtain the Rayleigh scattering intensity, absolute absorption cross section, spatial resolution, and spectral information of single-walled carbon nanotubes. By probing the optical resonance of hundreds of single-walled carbon nanotubes in a single measurement, the first technique utilizes Rayleigh scattering mechanism to obtain the chirality of carbon nanotubes. The second technique, by using high numerical aperture oil immersion objective lenses, we measure the absolute absorption cross section of a single-walled carbon nanotube. Combining all the quantitative values obtained from these techniques, we observe various interesting and recently discovered physical behaviors, such as long range optical coupling and universal optical conductivity on resonance, and demonstrate the possibility of accurate quantitative absorption measurement for individual structures at nanometer scale.

  10. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  11. Reactor wall for thermonuclear device

    International Nuclear Information System (INIS)

    Walls of structures in a thermonuclear reactor undergo irradiation and thermal loads and particle loads by high energy particles from plasmas to cause abrasion in the reactor walls or radiation loss of plasmas. In view of the above, the reactor walls of the present invention are constituted by making the plane of lamination of 2-dimensionally woven carbon fiber composite materials in perpendicular to the heat receiving surface of armors or metallurgically joining the carbon fiber composite materials and heat sink members so as to intersect the plane of the lamination. Since the lamination surface of the armor made of 2-dimensionally woven carbon fiber composite material is in parallel with the macro view stream of heat in the armors, there is no greater temperature difference between adjacent laminations. In addition, since the heat conductivity is high in the direction in parallel with the lamination phase of the carbon fiber composite material, the temperature increase at the face of the armor is reduced with identical amount of input heat to reduce the abrasion by sublimation. Further, since they are metallurgically joined with heat sink members, no large residual stresses remain after the joining. (K.M.)

  12. Flooding Effect on Earth Walls

    Directory of Open Access Journals (Sweden)

    Meysam Banimahd

    2010-12-01

    Full Text Available Earth building is a sustainable, environmentally friendly and economical method of construction that has been used worldwide for many centuries. For the past three decades, earth has seen a revival as a building material for a modern construction method due to its benefits in terms of low carbon content, low cost and energy involved during construction, as well as the fact that it is a sustainable technology of building. Climate change is influencing precipitation levels and patterns around the world, and as a consequence, flood risk is increasing rapidly. When flooding occurs, earth buildings are exposed to water by submersion, causing an increase in the degree of saturation of the earth structures and therefore a decrease of the suction between particles. This study investigated the effect of cycles of flooding (consecutive events of flooding followed by dry periods on earth walls. A series of characterization tests were carried out to obtain the physical and mechanical properties of the studied earth material. In a second stage, Flooding Simulation Tests (FST were performed to explore the earth walls’ response to repeated flooding events. The results obtained for the tested earth wall/samples with reinforced material (straw reveal hydraulic hysteresis when wall/samples are subject to cycles of wetting and drying.

  13. Enabling Support of Collaborative Cross-enterprise Business Processes for Legacy ERP Systems

    Directory of Open Access Journals (Sweden)

    Gundars Alksnis

    2015-04-01

    Full Text Available In order to create innovative business products, share knowledge between people and businesses, or increase the control and quality of services, more and more often enterprise business processes involve in collaborations by delegating or providing some pieces of work to other enterprises. Necessity to cooperate in the cross-enterprise setting leads to Collaborative Business Processes (CBPs. The difference between CBPs and Business Processes (BPs is in the decentralized coordination, flexible backward recovery, participants notification about the state, efficient adaptability to changes, presence of multiple information systems, and individual authorization settings. In the paper we consider a specific case of CBPs where multiple collaborating partners use Enterprise Resource Planning (ERP system of the same vendor. The vendor can see (e.g., monitor the changes of data elements, but does not have explicit process awareness in the ERP system to support flow of activities in the cross-enterprise setting. The paper also discusses different settings of cross-enterprise CBP and shows simplified enterprise models behind the vendor possibilities to positively impact collaborative processes. The restrictions of the vendor are implicit information flows in BP, diversity of ERP integrations with third party Information Systems (IS, the lack of mechanisms for monitoring BP instances, backward recovery, user notification about the current state and tasks, and inability to make explicit changes in customers’ ISs.

  14. Accelerating forward genetics for cell wall deconstruction

    OpenAIRE

    Vidaurre, Danielle; Bonetta, Dario

    2012-01-01

    The elucidation of the genes involved in cell wall synthesis and assembly remains one of the biggest challenges of cell wall biology. Although traditional genetic approaches, using simple yet elegant screens, have identified components of the cell wall, many unknowns remain. Exhausting the genetic toolbox by performing sensitized screens, adopting chemical genetics or combining these with improved cell wall imaging, hold the promise of new gene discovery and function. With the recent introduc...

  15. Cell Wall Integrity Signaling in Saccharomyces cerevisiae

    OpenAIRE

    Levin, David E.

    2005-01-01

    The yeast cell wall is a highly dynamic structure that is responsible for protecting the cell from rapid changes in external osmotic potential. The wall is also critical for cell expansion during growth and morphogenesis. This review discusses recent advances in understanding the various signal transduction pathways that allow cells to monitor the state of the cell wall and respond to environmental challenges to this structure. The cell wall integrity signaling pathway controlled by the small...

  16. How do plant cell walls extend?

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    This article briefly summarizes recent work that identifies the biophysical and biochemical processes that give rise to the extension of plant cell walls. I begin with the biophysical notion of stress relaxation of the wall and follow with recent studies of wall enzymes thought to catalyze wall extension and relaxation. Readers should refer to detailed reviews for more comprehensive discussion of earlier literature (Taiz, 1984; Carpita and Gibeaut, 1993; Cosgrove, 1993).

  17. Moss cell walls: structure and biosynthesis

    OpenAIRE

    Alison W. Roberts; Eric M Roberts; Haigler, Candace H.

    2012-01-01

    The genome sequence of the moss Physcomitrella patens has stimulated new research examining the cell wall polysaccharides of mosses and the glycosyl transferases that synthesize them as a means to understand fundamental processes of cell wall biosynthesis and plant cell wall evolution. The cell walls of mosses and vascular plants are composed of the same classes of polysaccharides, but with differences in side chain composition and structure. Similarly, the genomes of P. patens and angiosperm...

  18. Correlations of coronary plaque wall thickness with wall pressure and wall pressure gradient: a representative case study

    Directory of Open Access Journals (Sweden)

    Liu Biyue

    2012-07-01

    Full Text Available Abstract Background There are two major hemodynamic stresses imposed at the blood arterial wall interface by flowing blood: the wall shear stress (WSS acting tangentially to the wall, and the wall pressure (WP acting normally to the wall. The role of flow wall shear stress in atherosclerosis progression has been under intensive investigation, while the impact of blood pressure on plaque progression has been under-studied. Method The correlations of wall thickness (WT with wall pressure (WP, blood pressure on the lumen wall and spatial wall pressure gradient (WPG in a human atherosclerotic right coronary artery were studied. The pulsatile blood flow was simulated using a three dimensional mathematical model. The blood was treated as an incompressible viscous non-Newtonian fluid. The geometry of the artery was re-constructed using an in vivo intravascular ultrasound (IVUS 44-slice dataset obtained from a patient with consent obtained. The WT, the WP and the WPG were averaged on each slice, respectively, and Pearson correlation analysis was performed on slice averaged base. Each slice was then divided into 8 segments and averaged vessel WT, WP and WPG were collected from all 352 segments for correlation analysis. Each slice was also divided into 2 segments (inner semi-wall of bend and outer semi-wall of bend and the correlation analysis was performed on the 88 segments. Results Under mean pressure, the Pearson coefficient for correlation between WT and WP was r = − 0.52 (p  Conclusions Results from this representative case report indicated that plaque wall thickness correlated negatively with wall pressure (r = −0.81 by slice and positively with wall pressure gradient (r = 0.45. The slice averaged WT has a strong linear relationship with the slice averaged WP. Large-scale patient studies are needed to further confirm our findings.

  19. The structure of a jet in cross flow at low velocity ratios

    Science.gov (United States)

    Gopalan, Shridhar; Abraham, Bruce M.; Katz, Joseph

    2004-06-01

    This paper examines in detail the flow structure and associated wall pressure fluctuations caused by the injection of a round, turbulent jet into a turbulent boundary layer. The velocity ratio, r, ratio of mean jet velocity to the mean cross flow, varies from 0.5 to 2.5 and the Reynolds number based on the cross flow speed and jet diameter is 1.9×104. Particle image velocimetry is used to measure the flow and flush mounted pressure sensors installed at several locations used to determine the wall pressure. The results consist of sample instantaneous flow structures, distributions of mean velocity, vorticity and turbulence intensity, as well as wall pressure spectra. The flow structure depends strongly on the velocity ratio and there are two distinctly different regions. At low velocity ratios, namely r2, the near-wall flow behind the jet resembles a Karman vortex street and the wall-normal vortical structures contain cross flow boundary layer vorticity. Autospectra of the pressure signals show that the effect of the jet is mainly in the 15-100 Hz range. At r2, the wall pressure levels reach a plateau demonstrating the diminishing effect of the jet on the near-wall flow. Consistent with the flow structure, the highest wall pressure fluctuations occur off the jet centerline for r2. Also, the advection speed of near-wall vortical structures increase with r at r2 it is a constant.

  20. To detect anomalies in diaphragm walls

    NARCIS (Netherlands)

    Spruit, R.

    2015-01-01

    Diaphragm walls are potentially ideal retaining walls for deep excavations in densely built-up areas, as they cause no vibrations during their construction and provide structural elements with high strength and stiffness. In the recent past, however, several projects using diaphragm walls as soil an

  1. Behind-the-wall target identification (BWTI)

    Science.gov (United States)

    Yoon, Yeo-Sun; Amin, Moeness G.

    2009-05-01

    Through-the-wall radar imaging is of value in several civilian and defense applications. One of the challenges in through-the-wall radar imaging is the strong wall reflections which tend to persist over a long duration of time. In order to image weak and close by targets behind walls, the wall reflections should be suppressed, or at least be significantly alleviated. In this paper, we apply spatial filters across the antenna array to remove the spatial zero-frequency and low-frequency components which correspond to wall reflections. The application of spatial filters recognizes the fact that the wall EM responses do not significantly differ when viewed by the different antennas along the axis of a real or synthesized array aperture which is parallel to the wall. The proposed approach is tested with experimental data using solid wall, multi-layered wall, and cinder block wall. It is shown that the wall reflections can be effectively reduced by spatial preprocessing prior to beamforming, producing similar imaging results to those achieved when a background scene without the target is available.

  2. Casimir force for cosmological domain walls

    OpenAIRE

    Matsuda, Tomohiro

    2011-01-01

    We calculate the vacuum fluctuations that may affect the evolution of cosmological domain walls. Considering domain walls, which are classically stable and have interaction with a scalar field, we show that explicit symmetry violation in the interaction may cause quantum bias that can solve the cosmological domain wall problem.

  3. Steel Sheet Pile Walls in Soft Soil

    NARCIS (Netherlands)

    Kort, D.A.

    2002-01-01

    For almost a century, steel sheet pile walls are applied worldwide as earth retaining structures for excavations and quay walls. Within the framework of the development of European structural codes for Civil Engineering works, the Eurocodes, Eurocode 3 Part 5 for design of steel sheet pile walls was

  4. Domain walls. II. Baryon-number generation

    International Nuclear Information System (INIS)

    Domain walls present in the early universe due to a spontaneous breakdown of charge conjugation can leave behind net baryon number. SU/sub R/(2) instantons provide baryon nonconservation and the proton is effectively stable. Density perturbations (on scales large enough for galaxy formation) and monopole suppression can occur if walls dominate the energy density. Mechanisms for wall removal are discussed

  5. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for 50

  6. Unique aspects of the grass cell wall

    Science.gov (United States)

    Grasses are amongst the most important crops worldwide, and the composition of their cell walls is critical for uses as food, feed, and energy crops. Grass cell walls differ dramatically from dicot cell walls in terms of the major structural polysaccharides present, how those polysaccharides are lin...

  7. The mean velocity profile of near-wall turbulent flow

    OpenAIRE

    Kazakov, Kirill A.

    2014-01-01

    The issue of analytical derivation of the mean velocity profile in a near-wall turbulent flow is revisited in the context of a two-dimensional channel flow. An approach based on the use of dispersion relations for the flow velocity is developed. It is shown that for an incompressible flow conserving vorticity, there exists a decomposition of the velocity field into rotational and potential components, such that the restriction of the former to an arbitrary cross-section of the channel is a fu...

  8. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

    2010-02-15

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  9. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    International Nuclear Information System (INIS)

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  10. POROUS WALL, HOLLOW GLASS MICROSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, W.

    2012-06-30

    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to &apos

  11. Mechanism of bubble detachment from vibrating walls

    International Nuclear Information System (INIS)

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration

  12. Practical considerations in ultrasonic wall thickness measurement

    International Nuclear Information System (INIS)

    Ultrasonic inspection is widely used by industry for the detection of corrosion and the measurement of material wall thickness. Due to wall thinning and the various forms of corrosion that can be found in pressure piping and pressure vessels the annual cost of corrosion damage and related service failures, is very expensive. The author interest is primarily in the examination of personnel who need to become competent and certificated in the various skills that are required to carry out wall thickness measurement and detection of wall thinning due to corrosion. The various techniques and equipment available for ultrasonic wall thickness measurement and assessment give rise to problems regarding the accuracy of results and detection of corrosion. This paper will discuss some of the corrosion conditions that may occur and also problems that may arise during wall thickness measurement. Methods of improving the wall thickness measurement and the assessment process will also be discussed. (author)

  13. Surgery of chest wall deformities

    OpenAIRE

    Matos, AC; Bernardo, JE; Fernandes, LE; Antunes, MJ

    1997-01-01

    OBJECTIVE: To evaluate the medium-term results of 77 surgical corrections in patients with chest wall deformities, 53 (68.8%) with pectus excavatum and 24 with pectus carinatum, operated upon from 1985 to 1994. METHODS: The mean age of the patients was 14.7 years (4-39 years) and 77% were younger than 15 years of age. There were 59 male (76.7%) and 18 female patients. Only four had a family history of the malformation. Seven patients (9.1%) presented with asthma-like symptoms, and 13 (16....

  14. Green Walls for Clean Air

    OpenAIRE

    Gölsdorf, Katrin; Müller, Hans; Collier, Marcus

    2013-01-01

    Can plants help to improve the air quality? People have often complained about Ivy on buildings, but research by Helix Pflanzen GmbH, a company that is specialised in the cultivation of ivy species and the development of green wall technology, is shedding new light on an old problem. Using a cultivated variety of ivy (Hedera helix 'Wörner'), experiments were carried out that illustrated the binding effect that this Ivy has on fine dust particles. This is particularly important in urban ...

  15. Methodology for first wall design

    International Nuclear Information System (INIS)

    An analytic parametric scoping tool has been developed for application to first wall (FW) design problems. Both thermal and disruption force effects are considered. For the high heat flux and high disruption load conditions expected in the International Thermonuclear Experimental Reactor (ITER) device, Vanadium alloy and dispersion-strengthened copper offer the best stress margins using a somewhat flattened plasma-facing configuration. Ferritic steels also appear to have an acceptable stress margin, whereas the conventional stainless steel 316 does not appear feasible. If a full semicircle shape FW is required, only the Vanadium and ferritic steel alloy have acceptable solutions

  16. First Wall and Operational Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Lasnier, C; Allen, S; Boedo, J; Groth, M; Brooks, N; McLean, A; LaBombard, B; Sharpe, J; Skinner, C; Whyte, D; Rudakov, D; West, W; Wong, C

    2006-06-19

    In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER.

  17. Reflections on a flat wall

    International Nuclear Information System (INIS)

    This paper describes an investigation into whether estimates of attenuation in the flat sidewalls of the tunnel for the MC main ring can be based on a simple point-source/line-of-sight model. Having seen the limitations of such a model, an alternative is proposed where the main radiation source is not the initial object struck by the beam but the plane source provided by the first interactions of secondaries from the target in the shield-wall. This is shown to have a closer relation to reality than the point-source/line-of-sight model. (author)

  18. An improved resistive wall monitor

    International Nuclear Information System (INIS)

    Resistive wall monitors were designed and built for the Fermilab Main Injector project. These devices measure longitudinal beam current from 3 KHz to 4 GHz with a 1 ohm gap impedance. The new design provides a larger aperture and a calibration port to improve the accuracy of single-bunch intensity measurements. Microwave absorber material is used to reduce interference from spurious electromagnetic waves traveling inside the beam pipe. Several types of ferrite materials were evaluated for the absorber. Inexpensive ferrite rods were selected and assembled in an array forming the desired geometry without machining. copyright 1998 American Institute of Physics

  19. An improved resistive wall monitor

    International Nuclear Information System (INIS)

    Resistive wall monitors were designed and built for the Fermilab Main Injector project. These devices measure longitudinal beam current from 3 KHz to 4 GHz with a 1 ohm gap impedance. The new design provides a larger aperture and a calibration port to improve the accuracy of single-bunch intensity measurements. Microwave absorber material is used to reduce interference from spurious electromagnetic waves traveling inside the beam pipe. Several types of ferrite materials were evaluated for the absorber. Inexpensive ferrite rods were selected and assembled in an array forming the desired geometry without machining

  20. Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae

    DEFF Research Database (Denmark)

    Mikkelsen, Maria Dalgaard; Harholt, Jesper; Ulvskov, Peter;

    2014-01-01

    BACKGROUND AND AIMS: The charophyte green algae (CGA) are thought to be the closest living relatives to the land plants, and ancestral CGA were unique in giving rise to the land plant lineage. The cell wall has been suggested to be a defining structure that enabled the green algal ancestor to...... colonize land. These cell walls provide support and protection, are a source of signalling molecules, and provide developmental cues for cell differentiation and elongation. The cell wall of land plants is a highly complex fibre composite, characterized by cellulose cross-linked by non......-cellulosic polysaccharides, such as xyloglucan, embedded in a matrix of pectic polysaccharides. How the land plant cell wall evolved is currently unknown: early-divergent chlorophyte and prasinophyte algae genomes contain a low number of glycosyl transferases (GTs), while land plants contain hundreds. The number of GTs in...

  1. Mitigating the effects of surface morphology changes during ultrasonic wall thickness monitoring

    Science.gov (United States)

    Cegla, Frederic; Gajdacsi, Attila

    2016-02-01

    Ultrasonic wall thickness monitoring using permanently installed sensors has become a tool to monitor pipe wall thicknesses online and during plant operation. The repeatability of measurements with permanently installed transducers is excellent and can be in the nanometer range. It has, however, also been shown that the measured wall thickness is dependent on surface morphology and that when there are changes in surface morphology the monitored thickness trends can be affected. With an adaptive cross correlation approach, this effect can be successfully muted. However, under some surface morphology change conditions, this can also lead to inaccuracies. Here, an approach to detect when surface morphology changes can influence trend accuracies is presented. This method requires the combination of measurements from several sensors that independently sample an area where the same wall loss mechanism is assumed to occur. Simulation results for the effectiveness of the technique are presented.

  2. A New Rule-Based Strategy to Determine The Failure modes of Structural Walls

    International Nuclear Information System (INIS)

    Parameters affecting types of failure of reinforced concrete structural walls with arbitrary aspect ratios and cross section are investigated using data from numerous wall tests. Basically there are three known primary failure modes that covers prominent behavior of wall at the failure load. Shear failure is known by diagonal tension cracks and premature yielding of shear reinforcement that leads to abrupt none-ductile failure. To insure a ductile flexural failure, it is recommended that strength in shear be equal or grater than strength in flexure. Flexural-shear failure is another type of failure that needs to more details to identify explicitly and it is divided to two different cases namely web crushing or sliding shear failure. A new model is proposed to predict the failure modes of structural walls in terms of shear strength, nominal shear stress, shear force related to flexural capacity, the level of compression in concrete and control of sliding shear failure.

  3. Identification of a Streptococcus salivarius Cell Wall Component Mediating Coaggregation with Veillonella alcalescens VI

    Science.gov (United States)

    Weerkamp, Anton H.; McBride, Barry C.

    1981-01-01

    Cell walls of Streptococcus salivarius HB aggregated Veillonella alcalescens V1, but cell walls of the mutant S. salivarius HB-V5 did not. We found no correlation between the presence of fimbriae on streptococcal walls and the ability to aggregate Veillonella strains. Treatment of the walls with lysozyme solubilized a fraction which possessed Veillonella-aggregating activity. Solubilized cell wall preparations of strain HB contained three major (glyco)proteins as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and at least four antigens as determined by immunoelectrophoresis with antiserum prepared against strain HB walls. A specific antiserum, which was obtained by adsorption of anti-HB serum on strain HB-V5 cells, contained monospecific antibody that reacted with the solubilized strain HB wall preparation. Similar fractions prepared from strain HB-V5 cell walls did not possess aggregating activity and lacked one protein band (protein I) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and one antigen (antigen b) after immunoelectrophoresis. The same antigen was absent when lysozyme-solubilized wall preparations of strain HB were reacted with anti-HB-V5 serum. Crossed-immunoisoelectric focusing indicated that this specific (glyco)protein and this antigen were identical and had an isoelectric point of 4.60. Protein I and antigen b were specifically adsorbed when solubilized strain HB cell walls were incubated with V. alcalescens V1 but were not adsorbed by nonaggregating Veillonella parvula ATCC 10790 cells. Culture supernatants of strain HB contained V. alcalescens V1-aggregating activity. Antigen b was present in the culture supernatant, but was not found in cultures of strain HB-V5. A total of 18 S. salivarius isolates possessing the streptococcal group K antigen released aggregating activity and antigen b into the culture medium, but 11 strains which lacked the K-antigen did not. Images PMID:7251145

  4. Functional analyses of cotton (Gossypium hirsutum L.) immature fiber (im) mutant reveal that fiber cell wall development is associated with sensitivity to stress.

    Science.gov (United States)

    Background: Cotton fiber maturity refers the degree of fiber cell wall development and is an important factor for determining commercial value of cotton. The molecular mechanism regulating the fiber cell wall development has not been well characterized. Microscopic image analysis of the cross-sect...

  5. Reliability and Validity of Chinese Version of Boredom Proneness Scale%无聊倾向量表(BPS):中文版的结构、信度及效度

    Institute of Scientific and Technical Information of China (English)

    刘勇; 陈健芷; 宋琳婷; 赵宇; 杨晓丽; 张盼; 周卉

    2014-01-01

    目的:在大学生群体中引入无聊倾向量表(Boredom Proneness Scale,BPS),探讨该量表在中国文化背景下的因素结构,并检验其信效度.方法:采用BPS中文版调查了1230名大学生,收回有效问卷1129份.另用特质孤独量表、特质焦虑量表、自评抑郁量表和自评无聊倾向条目在90名大学生中检验效标关联效度.3周后随机抽取64名大学生进行重测.结果:BPS中文版包括内部刺激和外部刺激2个维度,低卷入、高卷入、高刺激需求、低刺激需求和缺乏耐性5个分量表,共20个条目;验证性因素分析显示数据拟合良好(x2/df=1.60,CFI=0.91,TLI=0.89,RM-SEA=0.04,SRMR=O.06);5个分量表的内部一致性信度在0.57~ 0.81之间,重测信度在0.69~ 0.83之间;BPS中文版具有较好的效标关联效度.结论:BPS中文版具有良好的信度和效度,可以用于大学生的无聊倾向测量.

  6. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  7. Retaining walls on subsidence areas

    International Nuclear Information System (INIS)

    The best results in treating structures subjected to mining-induced subsidence are achieved when the problem is divided into two parts. First, the mining engineer determines the magnitude of ground movements due to mining and transfers to the designer of the structure the value of expected subsidence and its components, such as surface curvature, tilt, and strain, both tensile and compressive. Second, the structural engineer, knowing the magnitudes of subsidence components, subgrade properties, such as soil capacity, specific weight, angle of internal friction, and deformation modulus, in addition to the characteristics and service requirements of the designed structure, is able to apply proper solutions to mitigate subsidence influence or to design the structure so that damage is minimized and serviceability is unobstructed by subsidence, both for existing and newly designed structures. In this paper, are derived formulas for calculating the horizontal soil pressure acting on freestanding retaining walls and basement walls of structures erected on mine subsidence areas. Different work conditions resulting in different values of soil pressure in non-mined and mine subsidence areas are analyzed. An example of a structure designed using the derived formulas is also given

  8. Ectopic lignification in primary cellulose-deficient cell walls of maize cell suspension cultures

    Institute of Scientific and Technical Information of China (English)

    Hugo Melida; Antonio Encina; Asier Largo-Gosens; Esther Novo-Uzal; Rogelio Santiago; Federico Pomar; Pedro Garca; Penelope Garca-Angulo; Jose Luis Acebes; Jesus Alvarez

    2015-01-01

    Maize (Zea mays L.) suspension-cultured cells with up to 70% less cellulose were obtained by stepwise habituation to dichlobenil (DCB), a cellulose biosynthesis inhibitor. Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by Fourier transform infrared (FTIR) spectroscopy. Cell wall compositional analysis indicated that the cellulose-deficient cell walls showed an enhancement of highly branched and cross-linked arabinoxylans, as well as an increased content in ferulic acid, diferulates and p-coumaric acid, and the presence of a polymer that stained positive for phloroglucinol. In accordance with this, cellulose-deficient cell walls showed a fivefold increase in Klason-type lignin. Thioacidolysis/GC-MS analysis of cellulose-deficient cell walls indicated the presence of a lignin-like polymer with a Syringyl/Guaiacyl ratio of 1.45, which differed from the sensu stricto stress-related lignin that arose in response to short-term DCB-treatments. Gene expression analysis of these cells indicated an overexpression of genes specific for the biosynthesis of monolignol units of lignin. A study of stress signaling pathways revealed an overexpression of some of the jasmonate signaling pathway genes, which might trigger ectopic lignification in response to cell wall integrity disruptions. In summary, the structural plasticity of primary cell walls is proven, since a lignification process is possible in response to cellulose impoverishment.

  9. Study of heat transfer in the heating wall during nucleate pool boiling

    International Nuclear Information System (INIS)

    The subject of this these is to show the role of heat transfer in the wall during saturated pool boiling. This effect, usually neglected in the modelizations of boiling, can explain some behaviours of the ebullition cycle and of the activities of nucleation sites. Il has been found that the ebullition cycle can be described by two steps: (1) during bubble growth, the wall temperature decreases due to the evaporation of the micro-layer at the base of the bubble; (2) initial superheat is re-established mainly by radial heat conduction in the wall. It is then possible to account for the variations of the wall temperature displayed by liquid crystals put a the bottom of the heating surface, and for the influence of the contact angle on the heat transfer. In the case of the infinitely thick wall the main results are that the thermal transfer during the growth of the bubble depends on the thermal properties of both wall and liquid and that the time separating the detachment of a bubble and its replacement by a new one is proportional to the cross-section of the bubble and to the thermal diffusivity of the wall

  10. Structural Insight into Cell Wall Architecture of Micanthus sinensis cv. using Correlative Microscopy Approaches.

    Science.gov (United States)

    Ma, Jianfeng; Lv, Xunli; Yang, Shumin; Tian, Genlin; Liu, Xing'e

    2015-10-01

    Structural organization of the plant cell wall is a key parameter for understanding anisotropic plant growth and mechanical behavior. Four imaging platforms were used to investigate the cell wall architecture of Miscanthus sinensis cv. internode tissue. Using transmission electron microscopy with potassium permanganate, we found a great degree of inhomogeneity in the layering structure (4-9 layers) of the sclerenchymatic fiber (Sf). However, the xylem vessel showed a single layer. Atomic force microscopy images revealed that the cellulose microfibrils (Mfs) deposited in the primary wall of the protoxylem vessel (Pxv) were disordered, while the secondary wall was composed of Mfs oriented in parallel in the cross and longitudinal section. Furthermore, Raman spectroscopy images indicated no variation in the Mf orientation of Pxv and the Mfs in Pxv were oriented more perpendicular to the cell axis than that of Sfs. Based on the integrated results, we have proposed an architectural model of Pxv composed of two layers: an outermost primary wall composed of a meshwork of Mfs and inner secondary wall containing parallel Mfs. This proposed model will support future ultrastructural analysis of plant cell walls in heterogeneous tissues, an area of increasing scientific interest particularly for liquid biofuel processing. PMID:26358178

  11. RG Domain Walls and Hybrid Triangulations

    CERN Document Server

    Dimofte, Tudor; van der Veen, Roland

    2013-01-01

    This paper studies the interplay between the N=2 gauge theories in three and four dimensions that have a geometric description in terms of twisted compactification of the six-dimensional (2,0) SCFT. Our main goal is to construct the three-dimensional domain walls associated to any three-dimensional cobordism. We find that we can build a variety of 3d theories that represent the local degrees of freedom at a given domain wall in various 4d duality frames, including both UV S-dual frames and IR Seiberg-Witten electric-magnetic dual frames. We pay special attention to Janus domain walls, defined by four-dimensional Lagrangians with position-dependent couplings. If the couplings on either side of the wall are weak in different UV duality frames, Janus domain walls reduce to S-duality walls, i.e. domain walls that encode the properties of UV dualities. If the couplings on one side are weak in the IR and on the other weak in the UV, Janus domain walls reduce to RG walls, i.e. domain walls that encode the properties...

  12. Electrons in ferromagnets with domain walls

    International Nuclear Information System (INIS)

    Domain walls can significantly modify electronic properties of ferromagnetic metals. In this paper we consider theoretically the influence of domain walls on transport properties of ferromagnetic materials and the results are compared with recent experiments. In the case of diffusive transport through a thick domain wall, the semiclassical approximation is applied and a local spin transformation is performed, which replaces the system with a domain wall by the corresponding system without a domain wall but with an additional gauge field. Due to a redistribution of single-particle electron states at the wall, one obtains then either negative or positive contributions to resistivity. The situation is different for very narrow and/or constrained domain walls. In such a case, the semiclassical approximation is not valid. Instead of this the approach based on scattering matrix is applied. The domain wall then gives rise to a large positive contribution to electrical resistivity. The corresponding magnetoresistance can be therefore very large, which is in agreement with recent experiments. The limiting case of narrow domain walls in systems with a single conduction channel is analysed in detail, with the effects due to electron-electron interaction taken into account. In this particular case the magnetoresistance due to a domain wall can be extremely large

  13. FEMA DFIRM Cross Sections

    Data.gov (United States)

    Minnesota Department of Natural Resources — FEMA Cross Sections are required for any Digital Flood Insurance Rate Map database where cross sections are shown on the Flood Insurance Rate Map (FIRM). Normally...

  14. American Red Cross

    Science.gov (United States)

    ... to Help Sand Fire Evacuees » 90% of the Red Cross Workforce are Volunteers Learn More. Search for ... Volunteer» Digital Advocates» SEARCH FOR OPENINGS Shop the Red Cross Store Be Prepared and Ready to Respond ...

  15. Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space.

    Directory of Open Access Journals (Sweden)

    Kazuyuki Wakabayashi

    Full Text Available Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA and p-coumaric acid, but it suppressed increases in diferulic acid (DFA isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL and cell wall-bound peroxidase (CW-PRX in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions.

  16. Estimates of elastic fracture mechanics parameters for thick walled pipes with slanted axial through wall cracks

    International Nuclear Information System (INIS)

    The present paper provides the elastic stress intensity factors (SIFs) and the crack opening displacements (CODs) of a thick walled pipe with a slanted axial through wall crack. For estimating these elastic fracture mechanics parameters, systematic three dimensional elastic finite element (FE) analyses were performed by considering geometric variables, i. e., thickness of pipe, reference crack length, and crack length ratio, affecting the SIFs and CODs. As for loading condition, the internal pressure was considered. Based on the FE results, the SIFs and CODs of slanted axial through wall cracks in a thick-walled pipe along the crack front and the wall thickness were calculated. In particular, to calculate the SIFs of a thick walled pipe with a slanted axial through wall crack from those of a thick walled pipe with an idealized axial through wall crack, a slant correction factor representing the effect of the slant crack on the SIFs was proposed

  17. Architecture of dermatophyte cell Walls: Electron microscopic and biochemical analysis

    Science.gov (United States)

    Nozawa, Y.; Kitajima, Y.

    1984-01-01

    A review with 83 references on the cell wall structure of dermatophytes is presented. Topics discussed include separation and preparation of cell walls; microstructure of cell walls by electron microscopy; chemical composition of cell walls; structural model of cell walls; and morphological structure of cell walls.

  18. Shape dynamics of growing cell walls

    CERN Document Server

    Banerjee, Shiladitya; Dinner, Aaron R

    2015-01-01

    We introduce a general theoretical framework to study the shape dynamics of actively growing and remodeling surfaces. Using this framework we develop a physical model for growing bacterial cell walls and study the interplay of cell shape with the dynamics of growth and constriction. The model allows us to derive constraints on cell wall mechanical energy based on the observed dynamics of cell shape. We predict that exponential growth in cell size requires a constant amount of cell wall energy to be dissipated per unit volume. We use the model to understand and contrast growth in bacteria with different shapes such as spherical, ellipsoidal, cylindrical and toroidal morphologies. Coupling growth to cell wall constriction, we predict a discontinuous shape transformation, from partial constriction to cell division, as a function of the chemical potential driving cell-wall synthesis. Our model for cell wall energy and shape dynamics relates growth kinetics with cell geometry, and provides a unified framework to d...

  19. Hydrodynamics of ultra-relativistic bubble walls

    Directory of Open Access Journals (Sweden)

    Leonardo Leitao

    2016-04-01

    Full Text Available In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  20. System performances of the HADES-tRPC wall

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, Diego [GSI, Darmstadt (Germany)

    2008-07-01

    The HADES-tRPC is a Time-of-Flight wall in an end-cap configuration, designed for reaching a global time resolution of the order of 100 ps({sigma}) and an efficiency close to 100% over 8 m{sup 2}, with an average 180 tracks load, at a particle flux of several hundreds of Hz/cm{sup 2}. The design of the HADES experiment emphasizes a ToF wall that makes a cost-effective use of the electronic channels (2400 channels, 1ch/35 cm{sup 2}) in order to keep the average channel occupancy below 10%, without further requirements on space resolution (kept in the current design at modest levels of 40-80 mm{sup 2}). Based on that, phenomena like charge sharing, and of course cross-talk or electric coupling in between channels cannot be tolerated and are therefore suppressed to a large extent, through the careful electrical shielding of each individual tRPC cell. We present in-beam measurements (October 2007) at nominal flux loads, from a fully equipped sextant (1.3 m{sup 2}), focusing on the time resolution and efficiency for different primary ionizations, together with performance studies at high local track density (that we refer as multi-hit capability). The preliminary achieved global time resolution of 85 ps({sigma}), efficiency above 98% with a comfortable plateau, self-calibration capability, stability and low cross-talk (below 1%) together with capability for double-hit recovery and compact FEE electronics with Q-ToT conversion on-board and high dynamic range are the main features of this new ToF wall.

  1. System performances of the HADES-tRPC wall

    International Nuclear Information System (INIS)

    The HADES-tRPC is a Time-of-Flight wall in an end-cap configuration, designed for reaching a global time resolution of the order of 100 ps(σ) and an efficiency close to 100% over 8 m2, with an average 180 tracks load, at a particle flux of several hundreds of Hz/cm2. The design of the HADES experiment emphasizes a ToF wall that makes a cost-effective use of the electronic channels (2400 channels, 1ch/35 cm2) in order to keep the average channel occupancy below 10%, without further requirements on space resolution (kept in the current design at modest levels of 40-80 mm2). Based on that, phenomena like charge sharing, and of course cross-talk or electric coupling in between channels cannot be tolerated and are therefore suppressed to a large extent, through the careful electrical shielding of each individual tRPC cell. We present in-beam measurements (October 2007) at nominal flux loads, from a fully equipped sextant (1.3 m2), focusing on the time resolution and efficiency for different primary ionizations, together with performance studies at high local track density (that we refer as multi-hit capability). The preliminary achieved global time resolution of 85 ps(σ), efficiency above 98% with a comfortable plateau, self-calibration capability, stability and low cross-talk (below 1%) together with capability for double-hit recovery and compact FEE electronics with Q-ToT conversion on-board and high dynamic range are the main features of this new ToF wall

  2. ADULT ABDOMINAL WALL HERNIA IN IBADAN

    OpenAIRE

    Ayandipo, O.O; Afuwape, O.O.; Irabor, D. O.; Abdurrazzaaq, A.I.

    2015-01-01

    Background: Abdominal wall hernias are very common diseases encountered in surgical practice. Groin hernia is the commonest type of abdominal wall hernias. There are several methods of hernia repair but tension-free repair (usually with mesh) offers the least recurrent rate. Aim: To describe the clinical profile of anterior abdominal wall hernias and our experience in the surgical management of identified hernias Method: The project was a retrospective study of all patients with abdominal wal...

  3. Electron-wall Interaction in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; M. Keidar; N.J. Fisch

    2005-02-11

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates.

  4. Automotion of Domain Walls for Spintronic Interconnects

    OpenAIRE

    Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.

    2013-01-01

    We simulate automotion, the spontaneous transport of a magnetic domain wall under the influence of demagnetization and magnetic anisotropy, in nanoscale spintronic interconnects. In contrast to spin transfer driven magnetic domain wall motion, the proposed interconnects operate with only a transient current pulse and provide favorable scaling down to the 20nm scale. Cases of both in-plane and perpendicular magnetization are considered. Analytical dependence of the velocity of domain walls on ...

  5. Ultrasonic wall thickness measurement without coupling liquid

    International Nuclear Information System (INIS)

    If the material measured is part of the ultrasonic transducer, then one can do without the usual coupling liquid for ultrasonic measurement of wall thickness. Measuring equipment works on the basis of this electro-dynamic ultrasonic transducer, which has been developed to check the wall thickness (3 to 30 mm) of steel pipes with outside diameters of 25 to 180 mm. Double errors and local changes of wall thickness can be detected. (orig.)

  6. Tourism Development: Issues for Historic Walled Towns

    OpenAIRE

    Tomi Brezovec; David Bruce

    2009-01-01

    This paper discusses issues in tourism development and visitor management in historic walled towns. Historic towns and walled towns in particular, attract tourists that enjoy the preserved medieval ambience, architecture and picturesque streets. Tourism has an impact on economic and social life as well as on the urban and natural environment. Walled towns and cities with their obvious barriers exemplify and crystallise issues, challenges, and opportunities critical to the development of touri...

  7. Motional Effect on Wall Shear Stresses

    DEFF Research Database (Denmark)

    Kock, Samuel Alberg; Torben Fründ, Ernst; Yong Kim, Won

    Atherosclerosis is the leading cause of death and severe disability. Wall Shear Stress (WSS), the stress exerted on vessel walls by the flowing blood is a key factor in the development of atherosclerosis. Computational Fluid Dynamics (CFD) is widely used for WSS estimations. Most CFD simulations...... are based on static models to ease computational burden leading to inaccurate estimations. The aim of this work was to estimate the effect of vessel wall deformations (expansion and bending) on WSS levels....

  8. Charm physics with Moebius Domain Wall Fermions

    CERN Document Server

    Jüttner, Andreas; Tsang, Justus Tobias; Boyle, Peter; Marinkovic, Marina; Hashimoto, Shoji; Kaneko, Takashi; Cho, Yong-Gwi

    2015-01-01

    We present results showing that Domain Wall fermions are a suitable discretisation for the simulation of heavy quarks. This is done by a continuum scaling study of charm quarks in a M\\"obius Domain Wall formalism using a quenched set-up. We find that discretisation effects remain well controlled by the choice of Domain Wall parameters preparing the ground work for the ongoing dynamical $2+1f$ charm program of RBC/UKQCD.

  9. A Wall of Funnels Concentrates Swimming Bacteria▿

    OpenAIRE

    Galajda, Peter; Keymer, Juan; Chaikin, Paul; Austin, Robert

    2007-01-01

    Randomly moving but self-propelled agents, such as Escherichia coli bacteria, are expected to fill a volume homogeneously. However, we show that when a population of bacteria is exposed to a microfabricated wall of funnel-shaped openings, the random motion of bacteria through the openings is rectified by tracking (trapping) of the swimming bacteria along the funnel wall. This leads to a buildup of the concentration of swimming cells on the narrow opening side of the funnel wall but no concent...

  10. Vapor wall deposition in Teflon chambers

    OpenAIRE

    Zhang, X; R. H. Schwantes; R. C. McVay; H Lignell; M. M. Coggon; Flagan, R C; Seinfeld, J.H.

    2014-01-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecan...

  11. Shape dynamics of growing cell walls

    OpenAIRE

    Banerjee, Shiladitya; Scherer, Norbert F.; Dinner, Aaron R.

    2015-01-01

    We introduce a general theoretical framework to study the shape dynamics of actively growing and remodeling surfaces. Using this framework we develop a physical model for growing bacterial cell walls and study the interplay of cell shape with the dynamics of growth and constriction. The model allows us to derive constraints on cell wall mechanical energy based on the observed dynamics of cell shape. We predict that exponential growth in cell size requires a constant amount of cell wall energy...

  12. Thoracic Wall Reconstruction after Tumor Resection

    OpenAIRE

    HARATI, KAMRAN; Kolbenschlag, Jonas; Behr, Björn; Goertz, Ole; Hirsch, Tobias; Kapalschinski, Nicolai; Ring, Andrej; Lehnhardt, Marcus; Daigeler, Adrien

    2015-01-01

    Introduction Surgical treatment of malignant thoracic wall tumors represents a formidable challenge. In particular, locally advanced tumors that have already infiltrated critical anatomic structures are associated with a high surgical morbidity and can result in full-thickness defects of the thoracic wall. Plastic surgery can reduce this surgical morbidity by reconstructing the thoracic wall through various tissue transfer techniques. Sufficient soft-tissue reconstruction of the thoracic w...

  13. Neutron Wall at RIBLL Ⅱ

    Institute of Scientific and Technical Information of China (English)

    XuHuagen; XuHushan; LiWenfei; ZhanWenlong; XiaoGuoqing; GuoZhongyan; SunZhiyu; LiChen; ChenRuofu; MaYue; ZhangXueying[; JiaFei

    2003-01-01

    With the construction of the new Radioactive Ion Beam Line in Lanzhou (RIBLL Ⅱ) which connecting the CSRm and the CSRe, an experimental setup.The Time-of-Flight (ToF) technique was recognized as one of the best ways for neutron detection and it, is employed by the neutrons wall. Considering the high neutron multiplicity, the detector shouldal so have the ability to resolve the multiple hits. Moreover, a high detection efficiency for the neutrons with energies ranging from 100MeV to 1 GeV is also required besides the high granularity. In this case, the sampling hadronic calorimeter type of detector has been selected. In order to estimate the performance of the detector and

  14. Virtual gap dielectric wall accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  15. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The arteries can remodel their structure and function to adapt themselves to the mechanical environment. In various factors that lead to vascular remodeling, the shear stress on the arterial wall induced by the blood flow is of great importance. However, there are many technique difficulties in measuring the wall shear stress directly at present. In this paper, through analyzing the pulsatile blood flow in arteries, a method has been proposed that can determine the wall shear stress quantitatively by measuring the velocity on the arterial axis, and that provides a necessary means to discuss the influence of arterial wall shear stress on vascular remodeling.

  16. Fillability of Thin-Wall Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  17. Domain wall resistance in epitaxial Fe wires

    Energy Technology Data Exchange (ETDEWEB)

    Hassel, C., E-mail: christoph.hassel@uni-due.d [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, 47048 Duisburg (Germany); Roemer, F.M.; Reckers, N. [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, 47048 Duisburg (Germany); Kronast, F. [Bessy GmbH, Berlin (Germany); Dumpich, G.; Lindner, J. [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, 47048 Duisburg (Germany)

    2011-04-15

    We studied the magnetoresistance behavior of epitaxial Fe wires grown on GaAs(1 1 0) with varying widths at room temperature. Single nanowires show a wire width (w) dependence of the coercive field, which increases with 1/w for decreasing wire widths. This enables the pinning of a single domain wall in the connection area of two wires with different widths. Magnetoresistance measurements of such wire structures clearly reveal resistance contributions arising from a domain wall. The presence of the domain wall is proven by photoemission electron-microscopy with synchrotron radiation. Moreover, micromagnetic simulations are performed to determine the spin orientations, especially within the domain wall. This permits us to calculate the anisotropic magnetoresistance caused by the domain wall. Taking this into account, we determine the intrinsic domain wall resistance, for which we found a positive value of 0.2%, in agreement with theoretical predictions. - Research highlights: > Magnetoresistance of epitaxial Fe wires is studied. > Pinning of a single domain wall at constriction. > Detection of domain wall by resistance and XPEEM measurements. > AMR contribution calculated by micromagnetic simulations. > Positive intrinsic domain wall resistance in agreement with theory.

  18. Domain wall resistance in epitaxial Fe wires

    International Nuclear Information System (INIS)

    We studied the magnetoresistance behavior of epitaxial Fe wires grown on GaAs(1 1 0) with varying widths at room temperature. Single nanowires show a wire width (w) dependence of the coercive field, which increases with 1/w for decreasing wire widths. This enables the pinning of a single domain wall in the connection area of two wires with different widths. Magnetoresistance measurements of such wire structures clearly reveal resistance contributions arising from a domain wall. The presence of the domain wall is proven by photoemission electron-microscopy with synchrotron radiation. Moreover, micromagnetic simulations are performed to determine the spin orientations, especially within the domain wall. This permits us to calculate the anisotropic magnetoresistance caused by the domain wall. Taking this into account, we determine the intrinsic domain wall resistance, for which we found a positive value of 0.2%, in agreement with theoretical predictions. - Research highlights: → Magnetoresistance of epitaxial Fe wires is studied. → Pinning of a single domain wall at constriction. → Detection of domain wall by resistance and XPEEM measurements. → AMR contribution calculated by micromagnetic simulations. → Positive intrinsic domain wall resistance in agreement with theory.

  19. Glycoprotein component of plant cell walls

    International Nuclear Information System (INIS)

    The primary wall surrounding most dicotyledonous plant cells contains a hydroxyproline-rich glycoprotein (HRGP) component named extensin. A small group of glycopeptides solubilized from isolated cell walls by proteolysis contained a repeated pentapeptide glycosylated by tri- and tetraarabinosides linked to hydroxyproline and, by galactose, linked to serine. Recently, two complementary approaches to this problem have provided results which greatly increase the understanding of wall extensin. In this paper the authors describe what is known about the structure of soluble extensin secreted into the walls of the carrot root cells

  20. ON WALL SHEAR STRESS OF ARTERY

    Institute of Scientific and Technical Information of China (English)

    Liu Zhao-rong; Liu Bao-yu; Qin Kai-rong

    2003-01-01

    In this paper, a method was proposed that the wall shear stress of artery could be determined by measuring the centerline axial velocity and radial motion of arterial wall simultaneously.The method is simple in application and can get higher precision when it is used to determine the shear stress of arterial wall in vivo.As an example, the shear stress distribution in periodic oscillatory flow of human carotid was calculated and discussed.The computed results show that the shear stress distribution at any given instant is almost uniform and will be zero at the centerline and tends to maximum at the vessel wall.

  1. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  2. Skyrmions from Instantons inside Domain Walls

    CERN Document Server

    Eto, M; Ohashi, K; Tong, D; Eto, Minoru; Nitta, Muneto; Ohashi, Keisuke; Tong, David

    2005-01-01

    Some years ago, Atiyah and Manton described a method to construct approximate Skyrmion solutions from Yang-Mills instantons. Here we present a dynamical realization of this construction using domain walls in a five-dimensional gauge theory. The non-abelian gauge symmetry is broken in each vacuum but restored in the core of the domain wall, allowing instantons to nestle inside the wall. We show that the worldvolume dynamics of the wall is given by the Skyrme model, including the four-derivative term, and the instantons appear as Skyrmions.

  3. Corrections to the thin wall approximation in general relativity

    Science.gov (United States)

    Garfinkle, David; Gregory, Ruth

    1989-01-01

    The question is considered whether the thin wall formalism of Israel applies to the gravitating domain walls of a lambda phi(exp 4) theory. The coupled Einstein-scalar equations that describe the thick gravitating wall are expanded in powers of the thickness of the wall. The solutions of the zeroth order equations reproduce the results of the usual Israel thin wall approximation for domain walls. The solutions of the first order equations provide corrections to the expressions for the stress-energy of the wall and to the Israel thin wall equations. The modified thin wall equations are then used to treat the motion of spherical and planar domain walls.

  4. Airway wall thickness assessment: a new functionality in virtual bronchoscopy investigation

    Science.gov (United States)

    Saragaglia, A.; Fetita, C.; Brillet, P. Y.; Prêteux, F.; Grenier, P. A.

    2007-03-01

    While classic virtual bronchoscopy offers visualization facilities for investigating the shape of the inner airway wall surface, it provides no information regarding the local thickness of the wall. Such information may be crucial for evaluating the severity of remodeling of the bronchial wall in asthma and to guide bronchial biopsies for staging of lung cancers. This paper develops a new functionality with the virtual bronchoscopy, allowing to estimate and map the information of the bronchus wall thickness on the lumen wall surface, and to display it as coded colors during endoluminal navigation. The local bronchus wall thickness estimation relies on a new automated 3D segmentation approach using strong 3D morphological filtering and model-fitting. Such an approach reconstructs the inner/outer airway wall surfaces from multi-detector CT data as follows. First, the airway lumen is segmented and its surface geometry reconstructed using either a restricted Delaunay or a Marching Cubes based triangulation approach. The lumen mesh is then locally deformed in the surface normal direction under specific force constraints which stabilize the model evolution at the level of the outer bronchus wall surface. The developed segmentation approach was validated with respect to both 3D mathematicallysimulated image phantoms of bronchus-vessel subdivisions and to state-of-the-art cross-section area estimation techniques when applied to clinical data. The investigation in virtual bronchoscopy mode is further enhanced by encoding the local wall thickness at each vertex of the lumen surface mesh and displaying it during navigation, according to a specific color map.

  5. Changes in cell wall architecture of wheat coleoptiles grown under continuous hypergravity conditions

    Science.gov (United States)

    Wakabayashi, K.; Soga, K.; Kamisaka, S.; Hoson, T.

    Modifications of cell wall structure of wheat coleoptiles in response to continuous hypergravity (300 g) treatment were investigated. Length of coleoptiles exposed to hypergravity for 2-4 days from germination stage was 60-70% of that of 1 g control. The net amounts of cell wall polysaccharides, such as hemicellulose and cellulose, of hypergravity-treated coleoptiles increased as much as those of 1 g control coleoptiles during the incubation period. As a result, the levels of cell wall polysaccharides per unit length of coleoptile, which mean the thickness of cell walls, largely increased under hypergravity conditions. Particularly, the amounts of hemicellulosic polymers with middle molecular mass (0.2-1 MDa) largely increased from day 2 to 3 under hypergravity conditions. The major sugar components of the hemicellulose fraction are arabinose, xylose and glucose. The ratios of arabinose and xylose to glucose were higher in hypergravity-treated coleoptiles than in control coleoptiles. The fractionation of hemicellulosic polymers into the neutral and acidic polymers by the anion-exchange column showed that the levels of acidic polymers (mainly composed of arabinoxylans) in cell walls of hypergravity-treated coleoptiles were higher than those of control coleoptiles. In addition to wall polysaccharides, the amounts of cell wall-bound phenolics, such as ferulic acid and diferulic acid, substantially increased during the incubation period both in 1 g control and hypergravity-treated coleoptiles. Especially, the levels of diferulic acid which cross-links hemicellulosic polymers were higher in hypergravity-treated coleoptiles than in control coleoptiles during the incubation period. These results suggest that hypergravity stimuli from the germination stage bias the type of synthesized hemicellulosic polysaccharides, although they do not restrict the net synthesis of cell wall constituents in wheat coleoptiles. The stimulation of the synthesis of arabinoxylans and of the

  6. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    Energy Technology Data Exchange (ETDEWEB)

    David R. Farley

    2010-08-19

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  7. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    International Nuclear Information System (INIS)

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N (ge) 3, with a rotational temperature between the wall and feed gas temperatures. The N = 0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  8. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  9. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States)

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  10. Wall-Laws for High Speed Flows over Adiabatic and Isothermal Walls

    OpenAIRE

    Mohammadi, Bijan; Puigt, Guillaume

    2000-01-01

    We present the extension of our wall-laws developed for low-speed flows to super and hypersonic configurations. In particular, we are interested in flows over isothermal walls and account for heat transfer. We recall the main steps of the development: - Obtention of generalized wall functions for low-speed fluids, valid for all $y^+$, - Taking into account transversal effects. - Accounting for the compressible feature of the flow on adiabatic walls without using informations on the local boun...

  11. Cell wall remodelling enzymes modulate fungal cell wall elasticity and osmotic stress resistance

    OpenAIRE

    Ene, Iuliana; Walker, Louise; Schiavone, Marion; Lee, Keunsook K.; Dague, Etienne; Gow, Neil A.R.; Munro, Carol A

    2015-01-01

    The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Ce...

  12. Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

    OpenAIRE

    Levin, David E.

    2011-01-01

    The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to...

  13. When Walls are No Longer Barriers: Perception of Wall Height in Parkour

    OpenAIRE

    Taylor, J. Eric T.; Witt, Jessica; Sugovic, Mila

    2011-01-01

    Through training, skilled parkour athletes (traceurs) overcome everyday obstacles, such as walls, that are typically insurmountable. Traceurs and untrained novices estimated the height of walls and reported their anticipated ability to climb the wall. The traceurs perceived the walls as shorter than did novices. This result suggests that perception is scaled by the perceiver’s anticipated ability to act, and is consistent with the action-specific account of perception.

  14. When walls are no longer barriers: perception of wall height in parkour.

    Science.gov (United States)

    Taylor, J Eric T; Witt, Jessica K; Sugovic, Mila

    2011-01-01

    Through training, skilled parkour athletes (traceurs) overcome everyday obstacles, such as walls, that are typically insurmountable. Traceurs and untrained novices estimated the height of walls and reported their anticipated ability to climb the wall. The traceurs perceived the walls as shorter than did novices. This result suggests that perception is scaled by the perceiver's anticipated ability to act, and is consistent with the action-specific account of perception. PMID:21936305

  15. Wall thickness measurements of tubes by Internal Rotary Inspection System (IRIS)- a comparative study with metallography

    International Nuclear Information System (INIS)

    Internal Rotary Inspection System (IRIS) is a relatively new ultrasonic system of heat exchanger/ steam condenser tubes and pipelines for measurement of wall thinning and pitting due to corrosion. The wall thickness measurements made during a scan around the circumference of the tube are displayed as a stationary rectilinear display of circumferential cross section (Bscan) of the tube. The paper describes the results obtained on tubes of various materials used in process industries having corrosion on inner and outer surfaces of the tube. (author)

  16. Numerical simulation of polarization beam splitter with triangular lattice of multi-walled carbon nanotube arrays

    Science.gov (United States)

    Wu, Xingxing; Yun, Maojin; Wang, Mei; Liu, Chao; Li, Kai; Qin, Xiheng; Kong, Weijin; Dong, Lifeng

    2015-12-01

    A kind of polarization beam splitter with triangular lattice of multi-walled carbon nanotube arrays is designed and simulated. In the employed structure transverse-electric (TE) light is confined in the line defect with photonic band gap effect, while transverse-magnetic (TM) light is guided through it with extremely low diffraction. The performance of the designed polarization beam splitter is evaluated by utilizing optical properties of multi-walled carbon nanotubes, finite element modeling of wave propagation and transmission through periodic arrays. Simulation results indicate that the designed polarization beam splitter has low loss and less cross talk, and thereby may have practical applications in the integrated optical field.

  17. Field Ionization of Cold Atoms near the Wall of a Single Carbon Nanotube

    International Nuclear Information System (INIS)

    We observe the capture and field ionization of individual atoms near the side wall of a single suspended nanotube. Extremely large cross sections for ionization from an atomic beam are observed at modest voltages due to the nanotube's small radius and extended length. The effects of the field strength on both the atomic capture and the ionization process are clearly distinguished in the data, as are prompt and delayed ionizations related to the locations at which they occur. Efficient and sensitive neutral atom detectors can be based on the nanotube capture and wall ionization processes.

  18. Specific features of flash welding of thin-walled boiler tubes

    International Nuclear Information System (INIS)

    The possibility of flash welding of pipes from Kh18N12T steel with walls less than 4 mm thick was investigated. The structure of welds was studied with the aid of X-ray and electron microscopy methods. The results of the work was the development of a procedure for flash welding boiler pipes 32 mm in diameter and with 2 mm thick walls. There is observed a partial burning out of titanium in the welded joint, the content of other alloying elements remaining unchanged. The contact resistance of the cross section being welded is usable for a programmed control of the welding process

  19. Field Ionization of Cold Atoms near the Wall of a Single Carbon Nanotube

    CERN Document Server

    Goodsell, Anne; Golovchenko, J A; Hau, Lene Vestergaard; 10.1103/PhysRevLett.104.133002

    2010-01-01

    We observe the capture and field ionization of individual atoms near the side wall of a single suspended nanotube. Extremely large cross sections for ionization from an atomic beam are observed at modest voltages due to the nanotube's small radius and extended length. The effects of the field strength on both the atomic capture and the ionization process are clearly distinguished in the data, as are prompt and delayed ionizations related to the locations at which they occur. Efficient and sensitive neutral atom detectors can be based on the nanotube capture and wall ionization processes.

  20. Impact of the ENDF/B-VI Cross Section on the RPV Fluence Determination

    International Nuclear Information System (INIS)

    The calculations with the broad-group cross-section library Bugle-96, and atom displacement (dpa) cross sections for iron, both derived from ENDF/B-VI data, result in higher calculated fast neutron fluxes, better agreement of calculations with radiometric dosimeter measurements, and significantly slower dpa rate attenuation through pressure vessel walls relative to the results with their predecessors: the Sailor library and ASTM iron dpa cross sections