WorldWideScience

Sample records for twist ancillary aims

  1. Long-term pavement performance ancillary information management system (AIMS) reference guide.

    Science.gov (United States)

    2012-11-01

    This document provides information on the Long-Term Pavement Performance (LTPP) program ancillary information. : Ancillary information includes data, images, reference materials, resource documents, and other information that : support and extend the...

  2. Twisted light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-12-01

    Full Text Available Research at the Mathematical Optics Group uses "twisted" light to study new quatum-based information security systems. In order to understand the structure of "twisted" light, it is useful to start with an ordinary light beam with zero twist, namely...

  3. `Twisted' electrons

    Science.gov (United States)

    Larocque, Hugo; Kaminer, Ido; Grillo, Vincenzo; Leuchs, Gerd; Padgett, Miles J.; Boyd, Robert W.; Segev, Mordechai; Karimi, Ebrahim

    2018-04-01

    Electrons have played a significant role in the development of many fields of physics during the last century. The interest surrounding them mostly involved their wave-like features prescribed by the quantum theory. In particular, these features correctly predict the behaviour of electrons in various physical systems including atoms, molecules, solid-state materials, and even in free space. Ten years ago, new breakthroughs were made, arising from the new ability to bestow orbital angular momentum (OAM) to the wave function of electrons. This quantity, in conjunction with the electron's charge, results in an additional magnetic property. Owing to these features, OAM-carrying, or twisted, electrons can effectively interact with magnetic fields in unprecedented ways and have motivated materials scientists to find new methods for generating twisted electrons and measuring their OAM content. Here, we provide an overview of such techniques along with an introduction to the exciting dynamics of twisted electrons.

  4. Oliver Twist

    NARCIS (Netherlands)

    Dickens, Charles

    2005-01-01

    Oliver Twist is one of Dickens's most popular novels, with many famous film, television and musical adaptations. It is a classic story of good against evil, packed with humour and pathos, drama and suspense, in which the orphaned Oliver is brought up in a harsh workhouse, and then taken in and

  5. Twisted supersymmetry: Twisted symmetry versus renormalizability

    International Nuclear Information System (INIS)

    Dimitrijevic, Marija; Nikolic, Biljana; Radovanovic, Voja

    2011-01-01

    We discuss a deformation of superspace based on a Hermitian twist. The twist implies a *-product that is noncommutative, Hermitian and finite when expanded in a power series of the deformation parameter. The Leibniz rule for the twisted supersymmetry transformations is deformed. A minimal deformation of the Wess-Zumino action is proposed and its renormalizability properties are discussed. There is no tadpole contribution, but the two-point function diverges. We speculate that the deformed Leibniz rule, or more generally the twisted symmetry, interferes with renormalizability properties of the model. We discuss different possibilities to render a renormalizable model.

  6. Generalised twisted partition functions

    CERN Document Server

    Petkova, V B

    2001-01-01

    We consider the set of partition functions that result from the insertion of twist operators compatible with conformal invariance in a given 2D Conformal Field Theory (CFT). A consistency equation, which gives a classification of twists, is written and solved in particular cases. This generalises old results on twisted torus boundary conditions, gives a physical interpretation of Ocneanu's algebraic construction, and might offer a new route to the study of properties of CFT.

  7. Twisted network programming essentials

    CERN Document Server

    Fettig, Abe

    2005-01-01

    Twisted Network Programming Essentials from O'Reilly is a task-oriented look at this new open source, Python-based technology. The book begins with recommendations for various plug-ins and add-ons to enhance the basic package as installed. It then details Twisted's collection simple network protocols, and helper utilities. The book also includes projects that let you try out the Twisted framework for yourself. For example, you'll find examples of using Twisted to build web services applications using the REST architecture, using XML-RPC, and using SOAP. Written for developers who want to s

  8. 18 CFR 35.40 - Ancillary services.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Ancillary services. 35.40 Section 35.40 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... Sales of Electric Energy, Capacity and Ancillary Services at Market-Based Rates § 35.40 Ancillary...

  9. Twisted classical Poincare algebras

    International Nuclear Information System (INIS)

    Lukierski, J.; Ruegg, H.; Tolstoy, V.N.; Nowicki, A.

    1993-11-01

    We consider the twisting of Hopf structure for classical enveloping algebra U(g), where g is the inhomogeneous rotations algebra, with explicite formulae given for D=4 Poincare algebra (g=P 4 ). The comultiplications of twisted U F (P 4 ) are obtained by conjugating primitive classical coproducts by F element of U(c)xU(c), where c denotes any Abelian subalgebra of P 4 , and the universal R-matrices for U F (P 4 ) are triangular. As an example we show that the quantum deformation of Poincare algebra recently proposed by Chaichian and Demiczev is a twisted classical Poincare algebra. The interpretation of twisted Poincare algebra as describing relativistic symmetries with clustered 2-particle states is proposed. (orig.)

  10. WORKSHOP: Let's twist again..

    Energy Technology Data Exchange (ETDEWEB)

    Villalobos Baillie, Orlando

    1988-12-15

    In the quantum chromodynamics (QCD) candidate theory of interquark forces, calculations involve summing the effects from many different possible quark/gluon interactions. In addition to the 'leading term' frequently used as the basis for QCD calculations, additional contributions — so-called 'higher twists' — are modulated by powers of kinematical factors. An illuminating international workshop to discuss higher twist QCD was held at the College de France, Paris, from 21-23 September.

  11. Transverse kink oscillations in the presence of twist

    Science.gov (United States)

    Terradas, J.; Goossens, M.

    2012-12-01

    Context. Magnetic twist is thought to play an important role in coronal loops. The effects of magnetic twist on stable magnetohydrodynamic (MHD) waves is poorly understood because they are seldom studied for relevant cases. Aims: The goal of this work is to study the fingerprints of magnetic twist on stable transverse kink oscillations. Methods: We numerically calculated the eigenmodes of propagating and standing MHD waves for a model of a loop with magnetic twist. The azimuthal component of the magnetic field was assumed to be small in comparison to the longitudinal component. We did not consider resonantly damped modes or kink instabilities in our analysis. Results: For a nonconstant twist the frequencies of the MHD wave modes are split, which has important consequences for standing waves. This is different from the degenerated situation for equilibrium models with constant twist, which are characterised by an azimuthal component of the magnetic field that linearly increases with the radial coordinate. Conclusions: In the presence of twist standing kink solutions are characterised by a change in polarisation of the transverse displacement along the tube. For weak twist, and in the thin tube approximation, the frequency of standing modes is unaltered and the tube oscillates at the kink speed of the corresponding straight tube. The change in polarisation is linearly proportional to the degree of twist. This has implications with regard to observations of kink modes, since the detection of this variation in polarisation can be used as an indirect method to estimate the twist in oscillating loops.

  12. Ancillary Services Provided from DER

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.B.

    2005-12-21

    Distributed energy resources (DER) are quickly making their way to industry primarily as backup generation. They are effective at starting and then producing full-load power within a few seconds. The distribution system is aging and transmission system development has not kept up with the growth in load and generation. The nation's transmission system is stressed with heavy power flows over long distances, and many areas are experiencing problems in providing the power quality needed to satisfy customers. Thus, a new market for DER is beginning to emerge. DER can alleviate the burden on the distribution system by providing ancillary services while providing a cost adjustment for the DER owner. This report describes 10 types of ancillary services that distributed generation (DG) can provide to the distribution system. Of these 10 services the feasibility, control strategy, effectiveness, and cost benefits are all analyzed as in the context of a future utility-power market. In this market, services will be provided at a local level that will benefit the customer, the distribution utility, and the transmission company.

  13. Ancillary service provision from distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report summarises the findings of a study undertaken to investigate the potential for establishing ancillary service markets at the distribution level in the UK. Existing arrangements for ancillary service markets globally, the design of these markets, regulatory and legislative changes that may be required, different forms of distributed generation (DG), and prospects of increasing the connection to the distributed network are examined along with commercial frameworks and technical procedures, infrastructure requirements, and the effects on different market participants. The scope for new ancillary services at the distribution level, ancillary services from DG, the prospects for DG, commercial and technical aspects, and impact assessments are reviewed.

  14. Ancillary service provision from distributed generation

    International Nuclear Information System (INIS)

    2004-01-01

    This report summarises the findings of a study undertaken to investigate the potential for establishing ancillary service markets at the distribution level in the UK. Existing arrangements for ancillary service markets globally, the design of these markets, regulatory and legislative changes that may be required, different forms of distributed generation (DG), and prospects of increasing the connection to the distributed network are examined along with commercial frameworks and technical procedures, infrastructure requirements, and the effects on different market participants. The scope for new ancillary services at the distribution level, ancillary services from DG, the prospects for DG, commercial and technical aspects, and impact assessments are reviewed

  15. A Transformation Called "Twist"

    Science.gov (United States)

    Hwang, Daniel

    2010-01-01

    The transformations found in secondary mathematics curriculum are typically limited to stretches and translations (e.g., ACARA, 2010). Advanced students may find the transformation, twist, to be of further interest. As most available resources are written for professional-level readers, this article is intended to be an introduction accessible to…

  16. SpaceTwist

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Jensen, Christian Søndergaard; Xuegang, Huang

    2008-01-01

    -based matching generally fall short in offering practical query accuracy guarantees. Our proposed framework, called SpaceTwist, rectifies these shortcomings for k nearest neighbor (kNN) queries. Starting with a location different from the user's actual location, nearest neighbors are retrieved incrementally...

  17. Twisting the Mirror TBA

    NARCIS (Netherlands)

    Arutyunov, G.E.; de Leeuw, M.; van Tongeren, S.J.

    2010-01-01

    We study finite-size corrections to the magnon dispersion relation in three models which differ from string theory on AdS5 x S5 in their boundary conditions. Asymptotically, this is accomplished by twisting the transfer matrix in a way which manifestly preserves integrability. In model I all

  18. Exogam with its ancillary detectors

    International Nuclear Information System (INIS)

    Theisen, Ch.

    2004-01-01

    The goal of the meeting was to discuss the status of experiments using Exogam and its ancillary detectors. Presentations include details of experiments already run and those in preparation. This document gathers most of the slides presented at the meeting. The results of 7 experiments are described. There are 9 contributions as it follows: 1) presentation of the Vamos spectrometer p.1-15, 2) the Clara (detector) and Prisma (spectrometer) setup: status and perspectives p.16-33, 3) experiment E344aS: shape coexistence near the N=Z line and collective properties of Kr isotopes investigated by low-energy Coulomb excitation p.34-56, 4) experiment E389: study of effective charges at Sm 100 via the nuclear lifetime measurements in Pd 96 and Cd 98 p.57-68, 5) experiment E375: spectroscopy of trans-fermium nuclei p.69-91, 6) experiment E408S: He 8 on Pb 208 and Bi 209 p.92-102, 7) experiment E462: very neutron rich calcium isotopes at N=32, structure of magic Ca 54 studied by gamma-spectroscopy with deep inelastic reactions p.103-115, 8) experiment E451: searching for T=D pairing and a new coupling scheme in Pd 92 and Ru 88 p.116-141, and 9) experiment E404aS: identification of gamma rays in nuclei around the drip-line nucleus Sm 130 , probing the maximally deformed light rare earth region

  19. On the performance analysis of Savonius rotor with twisted blades

    Energy Technology Data Exchange (ETDEWEB)

    Saha, U.K.; Rajkumar, M. Jaya [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati-781 039 (India)

    2006-09-15

    The present investigation is aimed at exploring the feasibility of twisted bladed Savonius rotor for power generation. The twisted blade in a three-bladed rotor system has been tested in a low speed wind tunnel, and its performance has been compared with conventional semicircular blades (with twist angle of 0{sup o}). Performance analysis has been made on the basis of starting characteristics, static torque and rotational speed. Experimental evidence shows the potential of the twisted bladed rotor in terms of smooth running, higher efficiency and self-starting capability as compared to that of the conventional bladed rotor. Further experiments have been conducted in the same setup to optimize the twist angle. (author)

  20. Twisted quantum doubles

    Directory of Open Access Journals (Sweden)

    Daijiro Fukuda

    2004-01-01

    Full Text Available Using diagrammatic pictures of tensor contractions, we consider a Hopf algebra (Aop⊗ℛλA** twisted by an element ℛλ∈A*⊗Aop corresponding to a Hopf algebra morphism λ:A→A. We show that this Hopf algebra is quasitriangular with the universal R-matrix coming from ℛλ when λ2=idA, generalizing the quantum double construction which corresponds to the case λ=idA.

  1. Exogam with Vamos, Tiara and other ancillary detectors

    International Nuclear Information System (INIS)

    Lewitowicz, M.; Olivier, L.; Savajols, H.; Catford, W.; Raine, B.; Oliveira, F. de; Perru, O.; Podolyak, Z.; Redon, N.; Bouchez, E.; Simenel, C.; Stanoiu, M.; Lemmon, R.; Rubio, B.; Obertelli, A.; Cederwall, B.; Chapman, R.; Korten, W.; Rubio Barroso, B.

    2003-01-01

    The aim of this workshop was to discuss the status of experiments at GANIL facility using Exogam with Vamos, Tiara and other ancillary detectors. This document gathers most of the slides that were presented at the workshop, it concerns 8 presentations: 1) the status of Spiral and Spiral-II, 2) the status of Tiara (Tiara array is used for the study of nuclear transfer reactions with radioactive beams in inverse kinematics), 3) data acquisition for the ancillary detectors, 4) the identification of gamma-ray in nuclei around Sm 130 : probing the maximally deformed light rare earth region, 5) the Coulomb excitation of radioactive krypton beams (Kr 76 , Kr 74 ), 6) the influence of weakly bound neutrons on fusion around the Coulomb barrier, 7) single particle transfer on doubly-magic Ni 56 , and 8) the study of N=16 for neutron rich nuclei with Ne 26 (d,p)Ne 27 transfer reaction

  2. Industrial Demand Management Providing Ancillary Services to the Distribution Grid

    DEFF Research Database (Denmark)

    Rahnama, Samira; Green, Torben; Lyhne, Casper

    2017-01-01

    A prominent feature of the future smart grid is the active participation of the consumer side in ancillary service provision. Grid operators procure ancillary services, including regulating power, voltage control, frequency control, and so on, to ensure safe, reliable, and high-quality electricity...... delivery. Consumers' involvement requires new entities and infrastructure. A so-called aggregator has been introduced as a new player to manage the services that are offered by the consumption units. This paper describes an industrial scale experimental setup for evaluating a particular type of aggregator....... The aggregator aims to provide a distribution grid service from industrial thermal loads through a direct control policy. Our specific case studies are a supermarket refrigeration system and an HVac chiller in conjunction with an ice storage, which are virtually connected to the aggregator. Practical results...

  3. Twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Shindler, A.

    2007-07-01

    I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

  4. Twisted mass lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Shindler, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2007-07-15

    I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

  5. Twist limits for late twisting double somersaults on trampoline.

    Science.gov (United States)

    Yeadon, M R; Hiley, M J

    2017-06-14

    An angle-driven computer simulation model of aerial movement was used to determine the maximum amount of twist that could be produced in the second somersault of a double somersault on trampoline using asymmetrical movements of the arms and hips. Lower bounds were placed on the durations of arm and hip angle changes based on performances of a world trampoline champion whose inertia parameters were used in the simulations. The limiting movements were identified as the largest possible odd number of half twists for forward somersaulting takeoffs and even number of half twists for backward takeoffs. Simulations of these two limiting movements were found using simulated annealing optimisation to produce the required amounts of somersault, tilt and twist at landing after a flight time of 2.0s. Additional optimisations were then run to seek solutions with the arms less adducted during the twisting phase. It was found that 3½ twists could be produced in the second somersault of a forward piked double somersault with arms abducted 8° from full adduction during the twisting phase and that three twists could be produced in the second somersault of a backward straight double somersault with arms fully adducted to the body. These two movements are at the limits of performance for elite trampolinists. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. TEK twisted gradient flow running coupling

    CERN Document Server

    Pérez, Margarita García; Keegan, Liam; Okawa, Masanori

    2014-01-01

    We measure the running of the twisted gradient flow coupling in the Twisted Eguchi-Kawai (TEK) model, the SU(N) gauge theory on a single site lattice with twisted boundary conditions in the large N limit.

  7. Teaching Spatial Awareness for Better Twisting Somersaults.

    Science.gov (United States)

    Hennessy, Jeff T.

    1985-01-01

    The barani (front somersault with one-half twist) and the back somersault with one twist are basic foundation skills necessary for more advanced twisting maneuvers. Descriptions of these movements on a trampoline surface are offered. (DF)

  8. Twisting perturbed parafermions

    Directory of Open Access Journals (Sweden)

    A.V. Belitsky

    2017-07-01

    Full Text Available The near-collinear expansion of scattering amplitudes in maximally supersymmetric Yang–Mills theory at strong coupling is governed by the dynamics of stings propagating on the five sphere. The pentagon transitions in the operator product expansion which systematize the series get reformulated in terms of matrix elements of branch-point twist operators in the two-dimensional O(6 nonlinear sigma model. The facts that the latter is an asymptotically free field theory and that there exists no local realization of twist fields prevents one from explicit calculation of their scaling dimensions and operator product expansion coefficients. This complication is bypassed making use of the equivalence of the sigma model to the infinite-level limit of WZNW models perturbed by current–current interactions, such that one can use conformal symmetry and conformal perturbation theory for systematic calculations. Presently, to set up the formalism, we consider the O(3 sigma model which is reformulated as perturbed parafermions.

  9. Spinning geometry = Twisted geometry

    International Nuclear Information System (INIS)

    Freidel, Laurent; Ziprick, Jonathan

    2014-01-01

    It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)

  10. How to Twist a Knot

    DEFF Research Database (Denmark)

    Randrup, Thomas; Røgen, Peter

    1997-01-01

    is an invariant of ambient isotopy measuring the topological twist of the closed strip. We classify closed strips in euclidean 3-space by their knots and their twisting number. We prove that this classification exactly divides closed strips into isotopy classes. Using this classification we point out how some...

  11. AX Tank Farm ancillary equipment study

    International Nuclear Information System (INIS)

    SKELLY, W.A.

    1999-01-01

    This report examines the feasibility of remediating ancillary equipment associated with the 241-AX Tank Farm at the Hanford Site. Ancillary equipment includes surface structures and equipment, process waste piping, ventilation components, wells, and pits, boxes, sumps, and tanks used to make waste transfers to/from the AX tanks and adjoining tank farms. Two remedial alternatives are considered: (1) excavation and removal of all ancillary equipment items, and (2) in-situ stabilization by grout filling, the 241-AX Tank Farm is being employed as a strawman in engineering studies evaluating clean and landfill closure options for Hanford single-shell tanks. This is one of several reports being prepared for use by the Hanford Tanks Initiative Project to explore potential closure options and to develop retrieval performance evaluation criteria for tank farms

  12. Reconsidering the measurement of ancillary service performance.

    Science.gov (United States)

    Griffin, D T; Rauscher, J A

    1987-08-01

    Prospective payment reimbursement systems have forced hospitals to review their costs more carefully. The result of the increased emphasis on costs is that many hospitals use costs, rather than margin, to judge the performance of ancillary services. However, arbitrary selection of performance measures for ancillary services can result in managerial decisions contrary to hospital objectives. Managerial accounting systems provide models which assist in the development of performance measures for ancillary services. Selection of appropriate performance measures provides managers with the incentive to pursue goals congruent with those of the hospital overall. This article reviews the design and implementation of managerial accounting systems, and considers the impact of prospective payment systems and proposed changes in capital reimbursement on this process.

  13. Power system studies of new ancillary services

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit

    The objective of this report is to illustrate and analyse, by means of simulation test cases, the impact of wind power advanced ancillary services, like inertial response (IR), power oscillation damping (POD) and synchronising power (SP) on the power system. Generic models for wind turbine, wind...... power plant and power system are used in the investigation....

  14. Partial twisting for scalar mesons

    International Nuclear Information System (INIS)

    Agadjanov, Dimitri; Meißner, Ulf-G.; Rusetsky, Akaki

    2014-01-01

    The possibility of imposing partially twisted boundary conditions is investigated for the scalar sector of lattice QCD. According to the commonly shared belief, the presence of quark-antiquark annihilation diagrams in the intermediate state generally hinders the use of the partial twisting. Using effective field theory techniques in a finite volume, and studying the scalar sector of QCD with total isospin I=1, we however demonstrate that partial twisting can still be performed, despite the fact that annihilation diagrams are present. The reason for this are delicate cancellations, which emerge due to the graded symmetry in partially quenched QCD with valence, sea and ghost quarks. The modified Lüscher equation in case of partial twisting is given

  15. Photophysics of internal twisting

    International Nuclear Information System (INIS)

    Heisel, F.; Miehe, J.A.; Lippert, E.; Rettig, W.; Bonacic-Koutecky, V.

    1987-01-01

    The formation and characteristics of the ''twisted intermolecular charge transfer'' is studied. Basic concepts on dual fluorescence, steady-state fluorescence, kinetic investigations and cage effects are discussed. The theoretical treatment on the electronic structure of the bonded π - donor - π acceptor pairs is outlined. The two-electron, two-orbital model, the ab initio CI models of simple double, charged and dative π - bonds as well as complex dative π - bonds and the origin of the dual fluorescence of 9.9'-Bianthryl are shown. Concerning the stochastic description of chemical reactions, Master equation, Markov, Birth-Death and Diffusion processes, Kramers-Moyal expansion, Langevin equation, Kramers' approach to steady-state rates of reaction and its extension to non-Markovian processes, and also unimolecular reactions in the absence of potential barrier are considered. Experimental results and interpretation on dynamics of DMABN in the excited state, kinetics of other dialkylanilines, extended donor-acceptor systems with anomalous fluorescence and donor-acceptor systems without anomalous fluorescence are given

  16. Windings of twisted strings

    Science.gov (United States)

    Casali, Eduardo; Tourkine, Piotr

    2018-03-01

    Twistor string models have been known for more than a decade now but have come back under the spotlight recently with the advent of the scattering equation formalism which has greatly generalized the scope of these models. A striking ubiquitous feature of these models has always been that, contrary to usual string theory, they do not admit vibrational modes and thus describe only conventional field theory. In this paper we report on the surprising discovery of a whole new sector of one of these theories which we call "twisted strings," when spacetime has compact directions. We find that the spectrum is enhanced from a finite number of states to an infinite number of interacting higher spin massive states. We describe both bosonic and world sheet supersymmetric models, their spectra and scattering amplitudes. These models have distinctive features of both string and field theory, for example they are invariant under stringy T-duality but have the high energy behavior typical of field theory. Therefore they describe a new kind of field theories in target space, sitting on their own halfway between string and field theory.

  17. Creating competitive markets for ancillary services

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, E.; Kirby, B.

    1997-10-01

    This report describes the structure of, and results from, a spreadsheet model. The model simulates markets for seven services: losses, regulation, spinning reserve, supplemental reserve,load following, energy imbalance, and voltage support. For completeness, the model also calculates costs for system control, although this service will continue to be provided solely the the system operator under cost-based prices. This computer model demonstrated the likely complexity of markets for energy and ancillary services. This complexity arises because these markets are highly interdependent. Because these markets are interactive, the costs and therefore the prices of these services will vary considerably as functions of system load and the current spot price of energy. The price of ancillary services in aggregate is highly correlated with the price of energy. A base-case utility was developed for use with the model and included in the report.

  18. Reaction mechanism of the acidic hydrolysis of highly twisted amides: Rate acceleration caused by the twist of the amide bond.

    Science.gov (United States)

    Mujika, Jon I; Formoso, Elena; Mercero, Jose M; Lopez, Xabier

    2006-08-03

    We present an ab initio study of the acid hydrolysis of a highly twisted amide and a planar amide analogue. The aim of these studies is to investigate the effect that the twist of the amide bond has on the reaction barriers and mechanism of acid hydrolysis. Concerted and stepwise mechanisms were investigated using density functional theory and polarizable continuum model calculations. Remarkable differences were observed between the mechanism of twisted and planar amide, due mainly to the preference for N-protonation of the former and O-protonation of the latter. In addition, we were also able to determine that the hydrolytic mechanism of the twisted amide will be pH dependent. Thus, there is a preference for a stepwise mechanism with formation of an intermediate in the acid hydrolysis, whereas the neutral hydrolysis undergoes a concerted-type mechanism. There is a nice agreement between the characterized intermediate and available X-ray data and a good agreement with the kinetically estimated rate acceleration of hydrolysis with respect to analogous undistorted amide compounds. This work, along with previous ab initio calculations, describes a complex and rich chemistry for the hydrolysis of highly twisted amides as a function of pH. The theoretical data provided will allow for a better understanding of the available kinetic data of the rate acceleration of amides upon twisting and the relation of the observed rate acceleration with intrinsic differential reactivity upon loss of amide bond resonance.

  19. Twisting the N=2 string

    International Nuclear Information System (INIS)

    Ketov, S.V.; Lechtenfeld, O.; Parkes, A.J.

    1993-12-01

    The most general homogeneous monodromy conditions in N= 2 string theory are classified in terms of the conjugacy classes of the global symmetry group U(1, 1) x Z 2 . For classes which generate a discrete subgroup Γ, the corresponding target space backgrounds C 1,1 /Γ include half spaces, complex orbifolds and tori. We propose a generalization of the intercept formula to matrix-valued twists, and find massless physical states in a number of twisted cases. In particular, the sixteen Z 2 -twisted sectors of the N = 2 string are investigated, and the corresponding ground states are identified via bosonization and BRST cohomology. We find enough room for an extended multiplet of 'spacetime' supersymmetry, with the number of supersymmetries being dependent on global 'spacetime' topology. Unfortunately, world-sheet locality for the chiral vertex operators does not permit interactions for the massless 'spacetime' fermions; however possibly, an asymmetric GSO projection could evade this problem. (orig.)

  20. Twisted Polynomials and Forgery Attacks on GCM

    DEFF Research Database (Denmark)

    Abdelraheem, Mohamed Ahmed A. M. A.; Beelen, Peter; Bogdanov, Andrey

    2015-01-01

    Polynomial hashing as an instantiation of universal hashing is a widely employed method for the construction of MACs and authenticated encryption (AE) schemes, the ubiquitous GCM being a prominent example. It is also used in recent AE proposals within the CAESAR competition which aim at providing...... in an improved key recovery algorithm. As cryptanalytic applications of our twisted polynomials, we develop the first universal forgery attacks on GCM in the weak-key model that do not require nonce reuse. Moreover, we present universal weak-key forgeries for the nonce-misuse resistant AE scheme POET, which...

  1. Introduction to twisted conformal fields

    International Nuclear Information System (INIS)

    Kazama, Y.

    1988-01-01

    A pedagogical account is given of the recent developments in the theory of twisted conformal fields. Among other things, the main part of the lecture concerns the construction of the twist-emission vertex operator, which is a generalization of the fermion emission vertex in the superstring theory. Several different forms of the vertex are derived and their mutural relationships are clarified. In this paper, the authors include a brief survey of the history of the fermion emission vertex, as it offers a good perspective in which to appreciate the logical development

  2. Ancillary services provided by PV power plants

    Directory of Open Access Journals (Sweden)

    Antonio PIERNO

    2016-07-01

    Full Text Available Renewable energy sources are widely utilized in distributed generation systems, and, recently, they are also considered for providing ancillary services. The paper is focused on PV plants, a survey of the most interesting papers published in the literature in the last decade is reported and the main characteristics of the technical proposals, with their advantages and limits, are evidenced. The results are schematically shown in a table that immediately gives the opportunity to be aware of what was already done, representing a reference tool.

  3. Waveguides with asymptotically diverging twisting

    Czech Academy of Sciences Publication Activity Database

    Krejčiřík, David

    2015-01-01

    Roč. 46, AUG (2015), s. 7-10 ISSN 0893-9659 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : quantum waveguide * exploding twisting * Quasi-bounded * Quasi-cylindrical * discrete spectrum Subject RIV: BE - Theoretical Physics Impact factor: 1.659, year: 2015

  4. Obstructions for twist star products

    Science.gov (United States)

    Bieliavsky, Pierre; Esposito, Chiara; Waldmann, Stefan; Weber, Thomas

    2018-05-01

    In this short note, we point out that not every star product is induced by a Drinfel'd twist by showing that not every Poisson structure is induced by a classical r-matrix. Examples include the higher genus symplectic Pretzel surfaces and the symplectic sphere S^2.

  5. The Twist Tensor Nuclear Norm for Video Completion.

    Science.gov (United States)

    Hu, Wenrui; Tao, Dacheng; Zhang, Wensheng; Xie, Yuan; Yang, Yehui

    2017-12-01

    In this paper, we propose a new low-rank tensor model based on the circulant algebra, namely, twist tensor nuclear norm (t-TNN). The twist tensor denotes a three-way tensor representation to laterally store 2-D data slices in order. On one hand, t-TNN convexly relaxes the tensor multirank of the twist tensor in the Fourier domain, which allows an efficient computation using fast Fourier transform. On the other, t-TNN is equal to the nuclear norm of block circulant matricization of the twist tensor in the original domain, which extends the traditional matrix nuclear norm in a block circulant way. We test the t-TNN model on a video completion application that aims to fill missing values and the experiment results validate its effectiveness, especially when dealing with video recorded by a nonstationary panning camera. The block circulant matricization of the twist tensor can be transformed into a circulant block representation with nuclear norm invariance. This representation, after transformation, exploits the horizontal translation relationship between the frames in a video, and endows the t-TNN model with a more powerful ability to reconstruct panning videos than the existing state-of-the-art low-rank models.

  6. Twist deformations of the supersymmetric quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Castro, P.G.; Chakraborty, B.; Toppan, F., E-mail: pgcastro@cbpf.b, E-mail: biswajit@bose.res.i, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Kuznetsova, Z., E-mail: zhanna.kuznetsova@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2009-07-01

    The N-extended supersymmetric quantum mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its universal enveloping superalgebra. Two constructions are possible. For even N one can identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist deformed (anti)commutators. The main differences between an abelian twist defined in terms of fermionic operators and an abelian twist defined in terms of bosonic operators are discussed. (author)

  7. Noncommutative geometry and twisted conformal symmetry

    International Nuclear Information System (INIS)

    Matlock, Peter

    2005-01-01

    The twist-deformed conformal algebra is constructed as a Hopf algebra with twisted coproduct. This allows for the definition of conformal symmetry in a noncommutative background geometry. The twisted coproduct is reviewed for the Poincare algebra and the construction is then extended to the full conformal algebra. The case of Moyal-type noncommutativity of the coordinates is considered. It is demonstrated that conformal invariance need not be viewed as incompatible with noncommutative geometry; the noncommutativity of the coordinates appears as a consequence of the twisting, as has been shown in the literature in the case of the twisted Poincare algebra

  8. Renormalization constants for 2-twist operators in twisted mass QCD

    International Nuclear Information System (INIS)

    Alexandrou, C.; Constantinou, M.; Panagopoulos, H.; Stylianou, F.; Korzec, T.

    2011-01-01

    Perturbative and nonperturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the nonperturbative evaluation of the one-derivative twist-2 vector and axial-vector operators. Nonperturbative results are obtained using the twisted mass Wilson fermion formulation employing two degenerate dynamical quarks and the tree-level Symanzik improved gluon action. The simulations have been performed for pion masses in the range of about 450-260 MeV and at three values of the lattice spacing a corresponding to β=3.9, 4.05, 4.20. Subtraction of O(a 2 ) terms is carried out by performing the perturbative evaluation of these operators at 1-loop and up to O(a 2 ). The renormalization conditions are defined in the RI ' -MOM scheme, for both perturbative and nonperturbative results. The renormalization factors, obtained for different values of the renormalization scale, are evolved perturbatively to a reference scale set by the inverse of the lattice spacing. In addition, they are translated to MS at 2 GeV using 3-loop perturbative results for the conversion factors.

  9. 42 CFR 414.40 - Coding and ancillary policies.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Coding and ancillary policies. 414.40 Section 414.40 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Practitioners § 414.40 Coding and ancillary policies. (a) General rule. CMS establishes uniform national...

  10. 39 CFR 122.1 - Ancillary special services.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Ancillary special services. 122.1 Section 122.1 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS § 122.1 Ancillary special services. (a) For the market-dominant...

  11. 16 CFR 1.62 - Ancillary court orders pending review.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Ancillary court orders pending review. 1.62 Section 1.62 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL PROCEDURES Injunctive and Condemnation Proceedings § 1.62 Ancillary court orders pending review...

  12. Integration of Flexible Consumers in the Ancillary Service Markets

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Westenholz, Mikkel; Hansen, Lars Henrik

    2014-01-01

    services. In this work we present a simple method based on the existing ancillary service markets that resolves these issues via increased information and communication technology. The method allows an aggregator to continuously utilize the markets for slower ancillary service to ensure that its portfolio...

  13. Report on survey for possibility of applying bio-technologies to biomass in fiscal 1999. Aiming at developing a kitchen refuse and waste water treatment and energy production system that can be installed as an ancillary facility of buildings; 1999 nendo biomass eno bio technology oyo kanosei chosa hokokusho. Biru nado no futai setsubi to shite secchi kanona, chukai, haisui nado no shori narabi ni energy seisan system no kaihatsu wo mezashite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This paper describes the survey and discussion on a system to treat microorganisms generated from organic wastes and recover bio-gas energy as an ancillary facility of buildings. The roof of a building is the most suitable location in terms of open space and odor problem, and because the waste liquid after energy recovery can be flown into the city sewage system. Suitable processes for energy recovery are the primary fermentation, followed further by second stage fermentation purposed of reducing BOD. Since rapid enhancement of the efficiency cannot be expected from the present methane fermentation technologies, it is worth discussing to convert the first step from methane fermentation to hydrogen fermentation, for which technological development is indispensable. Permission by the national or local government would be an important condition. Organic wastes treatment systems with different scales may be considered from wastes treatment in each house to treatment of wastes after collection on the whole city basis. Treating wastes with high water content, such as kitchen refuses and human waste is beneficial among organic wastes being collected and treated by local governments. It is beneficial because sorted collection for that purpose can be carried out, and existing incineration systems can be operated more efficiently. (NEDO)

  14. Effective potentials for twisted fields

    International Nuclear Information System (INIS)

    Banach, R.

    1981-01-01

    Minus the density of the effective action, evaluated at the lowest eigenfunction of the (space-time) derivative part of the second (functional) derivative of the classical action, is proposed as a generalised definition of the effective potential, applicable to twisted as well as untwisted sectors of a field theory. The proposal is corroborated by several specific calculations in the twisted sector, namely phi 4 theory (real and complex) and wrong-sign-Gordon theory, in an Einstein cylinder, where the exact integrability of the static solutions confirms the effective potential predictions. Both models exhibit a phase transition, which the effective potential locates, and the one-loop quantum shift in the critical radius is computed for the real phi 4 model, being a universal result. Topological mass generation at the classical level is pointed out, and the exactness of the classical effective potential approximation for complex phi 4 is discussed. (author)

  15. Twisting formula of epsilon factors

    Indian Academy of Sciences (India)

    Sazzad Ali Biswas

    2017-08-07

    Aug 7, 2017 ... In this article, we give a generalized twisting formula for ϵ(χ1χ2,ψ), when both χ1 and χ2 are ramified via the following local Jacobi sums. Let UF be the group of units in OF (ring of integers of F). For characters χ1, χ2 of F. × and a positive integer n, we define the local Jacobi sum. Jt(χ1,χ2, n) = ∑ x∈UF. Un.

  16. New twist on artificial muscles.

    Science.gov (United States)

    Haines, Carter S; Li, Na; Spinks, Geoffrey M; Aliev, Ali E; Di, Jiangtao; Baughman, Ray H

    2016-10-18

    Lightweight artificial muscle fibers that can match the large tensile stroke of natural muscles have been elusive. In particular, low stroke, limited cycle life, and inefficient energy conversion have combined with high cost and hysteretic performance to restrict practical use. In recent years, a new class of artificial muscles, based on highly twisted fibers, has emerged that can deliver more than 2,000 J/kg of specific work during muscle contraction, compared with just 40 J/kg for natural muscle. Thermally actuated muscles made from ordinary polymer fibers can deliver long-life, hysteresis-free tensile strokes of more than 30% and torsional actuation capable of spinning a paddle at speeds of more than 100,000 rpm. In this perspective, we explore the mechanisms and potential applications of present twisted fiber muscles and the future opportunities and challenges for developing twisted muscles having improved cycle rates, efficiencies, and functionality. We also demonstrate artificial muscle sewing threads and textiles and coiled structures that exhibit nearly unlimited actuation strokes. In addition to robotics and prosthetics, future applications include smart textiles that change breathability in response to temperature and moisture and window shutters that automatically open and close to conserve energy.

  17. Modeling and control of active twist aircraft

    Science.gov (United States)

    Cramer, Nicholas Bryan

    The Wright Brothers marked the beginning of powered flight in 1903 using an active twist mechanism as their means of controlling roll. As time passed due to advances in other technologies that transformed aviation the active twist mechanism was no longer used. With the recent advances in material science and manufacturability, the possibility of the practical use of active twist technologies has emerged. In this dissertation, the advantages and disadvantages of active twist techniques are investigated through the development of an aeroelastic modeling method intended for informing the designs of such technologies and wind tunnel testing to confirm the capabilities of the active twist technologies and validate the model. Control principles for the enabling structural technologies are also proposed while the potential gains of dynamic, active twist are analyzed.

  18. Twisting dependent properties of twisted carbon nanotube fibers: microstructure and strain transfer factors

    International Nuclear Information System (INIS)

    Zhou, Jinyuan; Xie, Erqing; Sun, Gengzhi; Zhan, Zhaoyao; Zheng, Lianxi

    2014-01-01

    The dependences of twisting parameters on the electric and mechanical properties of twisted CNT fibers were systematically studied. Results from electric and mechanical measurements showed that twisting intensity is very effective to improve the electric and mechanical properties of CNT fibers. Further calculations combined with Raman results indicate that the twisting treatments, to a certain extent, can greatly enhance the strain transfer factors of the samples, which dominates the mechanical properties of CNT fibers. In addition, studies on the effect of twisting speeds suggested that lower twisting speed can lead to higher uniformity but lower performances in the electric and mechanical properties, higher twisting speed to higher Young’s modulus and higher conductance but lower uniformities. Ultra-strong uniform CNT fibers need to be prepared with a suitable twisting speed. (paper)

  19. Remarks on twisted noncommutative quantum field theory

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, J. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2006-04-15

    We review recent results on twisted noncommutative quantum field theory by embedding it into a general framework for the quantization of systems with a twisted symmetry. We discuss commutation relations in this setting and show that the twisted structure is so rigid that it is hard to derive any predictions, unless one gives up general principles of quantum theory. It is also shown that the twisted structure is not responsible for the presence or absence of UV/IR-mixing, as claimed in the literature. (Orig.)

  20. DVCS amplitude with kinematical twist-3 terms

    International Nuclear Information System (INIS)

    Radyushkin, A.V.; Weiss, C.

    2000-01-01

    The authors compute the amplitude of deeply virtual Compton scattering (DVCS) using the calculus of QCD string operators in coordinate representation. To restore the electromagnetic gauge invariance (transversality) of the twist-2 amplitude they include the operators of twist-3 which appear as total derivatives of twist-2 operators. The results are equivalent to a Wandzura-Wilczek approximation for twist-3 skewed parton distributions. They find that this approximation gives a finite result for the amplitude of a longitudinally polarized virtual photon, while the amplitude for transverse polarization is divergent, i.e., factorization breaks down in this term

  1. Redefining Requirements of Ancillary Services for Technology Agnostic Sources

    DEFF Research Database (Denmark)

    Bondy, Daniel Esteban Morales; MacDonald, Jason; Kara, Emre Can

    2018-01-01

    New sources for ancillary services are needed, yet the requirements for service provision in most countries are explicitly formulated for traditional generators. This leads to waste of the potential for new technologies to deliver ancillary services. In order to harness this potential, we propose...... to parameterize the requirements of ancillary services so that reserves can be built by combining the advantageous properties of different technologies. The proposal is exemplified through a laboratory test where it shown that the system needs can be covered through cheaper and smaller reserves....

  2. Device for measuring well twistings

    Energy Technology Data Exchange (ETDEWEB)

    Kostin, Yu S; Golubin, S V; Keller, V F; Merzheyevskiy, A B; Zdorov, V P

    1982-01-01

    The device for measuring the well twistings with the use of fluids (poured into a vessel and which leave an imprint on the walls), containing a housing and adapter, is distinguished by the fact that in order to improve the accuracy of measurement by obtaining a clear imprint, it is equipped with cylinder that is spring-loaded in relation to the adapter, forming a vessel for fluid with the adapter. The adapter is made of two parts, one of which is made of neutral metal in relation to the fluid, and the other, from active in relation to the same fluid.

  3. New developments in segment ancillary logic for FASTBUS

    International Nuclear Information System (INIS)

    Walz, H.V.; Bertolucci, B.

    1983-01-01

    Segment Ancillary Logic hardware for FASTBUS systems provides logical functions required in common by all devices attached to a segment. It controls the execution of arbitration cycles, and geographical address cycles, and generates the system handshake responses for broadcast operations. The mandatory requirements for Segment Ancillary Logic in the FASTBUS specifications are reviewed. A detailed implementation based on ECL logic is described, and the hardware to be used on an ECL cable segment for an experimental FASTBUS system at SLAC is shown

  4. An analysis of ongoing trends in airline ancillary revenues

    OpenAIRE

    Warnock-Smith, David; O'Connell, John F.; Maleki, Mahnaz

    2017-01-01

    This paper examines the performance of the two core classifications of airline ancillary revenues, which are unbundled products and commission based income. It also investigates the willingness of passengers to pay (WTP) for these services together with what type of ancillary items are acceptable at a particular price point. The study found that passengers value a narrow range of perceived ‘necessity’ products and services such as food and drink, checked baggage and seat assignment as opposed...

  5. Options for pricing ancillary services in a deregulated power system

    Science.gov (United States)

    Yamin, Hatim Yahya

    2001-07-01

    GENCOs in restructured systems are compensated for selling energy in the market. In a restructured market, a mechanism is required to entice participants in the market to provide ancillary services and to ensure adequate compensation that would guarantee its economic viability. The ISO controls the dispatch of generation, manages the reliability of the transmission grid, provides open access to the transmission, buys and provides ancillary services as required, coordinates day-ahead, hour-ahead schedules and performs real time balancing of load and generation, settles real time imbalances and ancillary services sales and purchases. The ISO, also, administers congestion management protocols for the transmission grid. Since the ISO does not own any generating units it must ensure that there is enough reserves for maintaining reliability according to FERC regulations, and sufficient unloaded generating capacity for balancing services in a real-time market. The ISO could meet these requirements by creating a competitive market for ancillary services, which are metered and remain unbundled to provide an accurate compensation for each supplier and cost to each consumer, In this study, we give an overview for restructuring and ancillary services in a restructured power marketplace. Also, we discuss the effect of GENCOs' actions in the competitive energy and ancillary service markets. In addition, we propose an auction market design for hedging ancillary service costs in California market. Furthermore, we show how to include the n-1 and voltage contingencies in security constrained unit commitment. Finally, we present two approaches for GENCOs' unit commitment in a restructured power market; one is based on game theory and the other is based on market price forecasting. In each of the two GENCOs' unit commitment approaches, we discuss the GENCOs' optimal bidding strategies in energy and ancillary service markets to maximize the GENCOs' profit.

  6. Twist-stretch profiles of DNA chains

    Science.gov (United States)

    Zoli, Marco

    2017-06-01

    Helical molecules change their twist number under the effect of a mechanical load. We study the twist-stretch relation for a set of short DNA molecules modeled by a mesoscopic Hamiltonian. Finite temperature path integral techniques are applied to generate a large ensemble of possible configurations for the base pairs of the sequence. The model also accounts for the bending and twisting fluctuations between adjacent base pairs along the molecules stack. Simulating a broad range of twisting conformation, we compute the helix structural parameters by averaging over the ensemble of base pairs configurations. The method selects, for any applied force, the average twist angle which minimizes the molecule’s free energy. It is found that the chains generally over-twist under an applied stretching and the over-twisting is physically associated to the contraction of the average helix diameter, i.e. to the damping of the base pair fluctuations. Instead, assuming that the maximum amplitude of the bending fluctuations may decrease against the external load, the DNA molecule first over-twists for weak applied forces and then untwists above a characteristic force value. Our results are discussed in relation to available experimental information albeit for kilo-base long molecules.

  7. Dynamical twisted mass fermions and baryon spectroscopy

    International Nuclear Information System (INIS)

    Drach, V.

    2010-06-01

    The aim of this work is an ab initio computation of the baryon masses starting from quantum chromodynamics (QCD). This theory describes the interaction between quarks and gluons and has been established at high energy thanks to one of its fundamental properties: the asymptotic freedom. This property predicts that the running coupling constant tends to zero at high energy and thus that perturbative expansions in the coupling constant are justified in this regime. On the contrary the low energy dynamics can only be understood in terms of a non perturbative approach. To date, the only known method that allows the computation of observables in this regime together with a control of its systematic effects is called lattice QCD. It consists in formulating the theory on an Euclidean space-time and to evaluating numerically suitable functional integrals. First chapter is an introduction to the QCD in the continuum and on a discrete space time. The chapter 2 describes the formalism of maximally twisted fermions used in the European Twisted Mass (ETM) collaboration. The chapter 3 deals with the techniques needed to build hadronic correlator starting from gauge configuration. We then discuss how we determine hadron masses and their statistical errors. The numerical estimation of functional integral is explained in chapter 4. It is stressed that it requires sophisticated algorithm and massive parallel computing on Blue-Gene type architecture. Gauge configuration production is an important part of the work realized during my Ph.D. Chapter 5 is a critical review on chiral perturbation theory in the baryon sector. The two last chapter are devoted to the analysis in the light and strange baryon sector. Systematics and chiral extrapolation are extensively discussed. (author)

  8. The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise.

    Directory of Open Access Journals (Sweden)

    Craig Armstrong

    Full Text Available Increased left ventricular (LV twist and untwisting rate (LV twist mechanics are essential responses of the heart to exercise. However, previously a large variability in LV twist mechanics during exercise has been observed, which complicates the interpretation of results. This study aimed to determine some of the physiological sources of variability in LV twist mechanics during exercise. Sixteen healthy males (age: 22 ± 4 years, [Formula: see text]O2peak: 45.5 ± 6.9 ml∙kg-1∙min-1, range of individual anaerobic threshold (IAT: 32-69% of [Formula: see text]O2peak were assessed at rest and during exercise at: i the same relative exercise intensity, 40%peak, ii at 2% above IAT, and, iii at 40%peak with hypoxia (40%peak+HYP. LV volumes were not significantly different between exercise conditions (P > 0.05. However, the mean margin of error of LV twist was significantly lower (F2,47 = 2.08, P 0.05. Overall, LV twist mechanics were linearly related to rate pressure product. During exercise, the intra-individual variability of LV twist mechanics is smaller at the same relative exercise intensity compared with IAT. However, the absolute magnitude (degrees of LV twist mechanics appears to be associated with the prevailing rate pressure product. Exercise tests that evaluate LV twist mechanics should be standardised by relative exercise intensity and rate pressure product be taken into account when interpreting results.

  9. The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise

    Science.gov (United States)

    Armstrong, Craig; Samuel, Jake; Yarlett, Andrew; Cooper, Stephen-Mark; Stembridge, Mike; Stöhr, Eric J.

    2016-01-01

    Increased left ventricular (LV) twist and untwisting rate (LV twist mechanics) are essential responses of the heart to exercise. However, previously a large variability in LV twist mechanics during exercise has been observed, which complicates the interpretation of results. This study aimed to determine some of the physiological sources of variability in LV twist mechanics during exercise. Sixteen healthy males (age: 22 ± 4 years, V˙O2peak: 45.5 ± 6.9 ml∙kg-1∙min-1, range of individual anaerobic threshold (IAT): 32–69% of V˙O2peak) were assessed at rest and during exercise at: i) the same relative exercise intensity, 40%peak, ii) at 2% above IAT, and, iii) at 40%peak with hypoxia (40%peak+HYP). LV volumes were not significantly different between exercise conditions (P > 0.05). However, the mean margin of error of LV twist was significantly lower (F2,47 = 2.08, P 0.05). Overall, LV twist mechanics were linearly related to rate pressure product. During exercise, the intra-individual variability of LV twist mechanics is smaller at the same relative exercise intensity compared with IAT. However, the absolute magnitude (degrees) of LV twist mechanics appears to be associated with the prevailing rate pressure product. Exercise tests that evaluate LV twist mechanics should be standardised by relative exercise intensity and rate pressure product be taken into account when interpreting results. PMID:27100099

  10. Control of Spin Wave Dynamics in Spatially Twisted Magnetic Structures

    Science.gov (United States)

    2017-06-27

    control the spin wave dynamics of magnetic structures twisted spatially, we prepared the exchange-coupled films with the hard magnetic L10-FePt and...information writing of magnetic storage and spintronic applications. Introduction and Objective: Recent rapid progress in the research field of nano...scaled bilayer elements is also an important aim of this project. Approach/Method: The exchange-coupled films with the hard magnetic L10-FePt and

  11. TWIST1 a new determinant of epithelial to mesenchymal transition in EGFR mutated lung adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Karine Pallier

    Full Text Available Metastasis is a multistep process and the main cause of mortality in lung cancer patients. We previously showed that EGFR mutations were associated with a copy number gain at a locus encompassing the TWIST1 gene on chromosome 7. TWIST1 is a highly conserved developmental gene involved in embryogenesis that may be reactivated in cancers promoting both malignant conversion and cancer progression through an epithelial to mesenchymal transition (EMT. The aim of this study was to investigate the possible implication of TWIST1 reactivation on the acquisition of a mesenchymal phenotype in EGFR mutated lung cancer. We studied a series of consecutive lung adenocarcinoma from Caucasian non-smokers for which surgical frozen samples were available (n = 33 and showed that TWIST1 expression was linked to EGFR mutations (P<0.001, to low CDH1 expression (P<0.05 and low disease free survival (P = 0.044. To validate that TWIST1 is a driver of EMT in EGFR mutated lung cancer, we used five human lung cancer cell lines and demonstrated that EMT and the associated cell mobility were dependent upon TWIST1 expression in cells with EGFR mutation. Moreover a decrease of EGFR pathway stimulation through EGF retrieval or an inhibition of TWIST1 expression by small RNA technology reversed the phenomenon. Collectively, our in vivo and in vitro findings support that TWIST1 collaborates with the EGF pathway in promoting EMT in EGFR mutated lung adenocarcinoma and that large series of EGFR mutated lung cancer patients are needed to further define the prognostic role of TWIST1 reactivation in this subgroup.

  12. Correlation Between Expression of Twist and Podoplanin in Ductal Breast Carcinoma.

    Science.gov (United States)

    Grzegrzolka, Jedrzej; Wojtyra, Patrycja; Biala, Martyna; Piotrowska, Aleksandra; Gomulkiewicz, Agnieszka; Rys, Janusz; Podhorska-Okolow, Marzenna; Dziegiel, Piotr

    2017-10-01

    As a result of activation of transcription factors engaged in epithelial-mesenchymal transition (EMT), such as Twist, inhibition of epithelial markers and an increased expression of mesenchymal markers are observed. One of the specific markers of cancer-associated fibroblasts is podoplanin (PDPN) - a mucin-type membrane glycoprotein. The aim of this work was to study the localisation and intensity of expression of Twist and PDPN on the mRNA and protein level in cases of invasive ductal breast carcinoma (IDC), and its association with patients' clinico-pathological data. The study included archival material in a form of 80 paraffin IDC blocks and 11 IDC fragments frozen in liquid nitrogen. Immunohistochemical expression of Twist and PDPN was evaluated using light microscope and semiquantitative scale for evaluation of nuclear expression or immunoreactive scale (IRS) for evaluation of cytoplasmic expression. Material was isolated from frozen IDC fragments using laser micro-dissection (from cancer and stromal cells, separately) and was used to perform real-time PCR. Twist expression was higher in stromal cells in comparison to cancer cells. Analysis of patients' survival rate showed, that higher expression of Twist in cancer cells was associated with shorter overall survival time and shorter event-free survival time. The expression of PDPN was also higher in stromal cells in comparison with cancer cells. In addition, positive correlation was observed between expression of Twist and PDPN in stromal cells of IDC (r=0.267; p<0.05). The relationship between the higher expression of Twist in both cancer and stromal cells and shorter patients' survival indicates Twist as a potential useful prognostic marker in IDC. Positive correlation of Twist and PDPN expression may indicate the role of PDPN in EMT in IDC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Quantisation of monotonic twist maps

    International Nuclear Information System (INIS)

    Boasman, P.A.; Smilansky, U.

    1993-08-01

    Using an approach suggested by Moser, classical Hamiltonians are generated that provide an interpolating flow to the stroboscopic motion of maps with a monotonic twist condition. The quantum properties of these Hamiltonians are then studied in analogy with recent work on the semiclassical quantization of systems based on Poincare surfaces of section. For the generalized standard map, the correspondence with the usual classical and quantum results is shown, and the advantages of the quantum Moser Hamiltonian demonstrated. The same approach is then applied to the free motion of a particle on a 2-torus, and to the circle billiard. A natural quantization condition based on the eigenphases of the unitary time--development operator is applied, leaving the exact eigenvalues of the torus, but only the semiclassical eigenvalues for the billiard; an explanation for this failure is proposed. It is also seen how iterating the classical map commutes with the quantization. (authors)

  14. Profile of Hashimoto's Thyroiditis in Sri Lankans: Is There an Increased Risk of Ancillary Pathologies in Hashimoto's Thyroiditis?

    OpenAIRE

    Siriweera, Eranga Himalee; Ratnatunga, Neelakanthi Vajira Illangakoon

    2010-01-01

    Hashimoto's thyroiditis has been reported to be associated with many neoplastic and nonneoplastic thyroid pathologies. This retrospective study aims to determine the demographic profile of Hashimoto's thyroiditis in Sri Lankans, document ancillary pathologies in Hashimoto's thyroiditis, and determine whether there is an increased risk of occurrence of malignancies, benign neoplasms, and nonneoplastic benign lesions in Hashimoto's thyroiditis by comparing with thyroids showing multinodular goi...

  15. Four-point functions with a twist

    Energy Technology Data Exchange (ETDEWEB)

    Bargheer, Till [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2017-01-15

    We study the OPE of correlation functions of local operators in planar N=4 super Yang-Mills theory. The considered operators have an explicit spacetime dependence that is defined by twisting the translation generators with certain R-symmetry generators. We restrict to operators that carry a small number of excitations above the twisted BMN vacuum. The OPE limit of the four-point correlator is dominated by internal states with few magnons on top of the vacuum. The twisting directly couples all spacetime dependence of the correlator to these magnons. We analyze the OPE in detail, and single out the extremal states that have to cancel all double-trace contributions.

  16. Euclidean supersymmetry, twisting and topological sigma models

    International Nuclear Information System (INIS)

    Hull, C.M.; Lindstroem, U.; Santos, L. Melo dos; Zabzine, M.; Unge, R. von

    2008-01-01

    We discuss two dimensional N-extended supersymmetry in Euclidean signature and its R-symmetry. For N = 2, the R-symmetry is SO(2) x SO(1, 1), so that only an A-twist is possible. To formulate a B-twist, or to construct Euclidean N = 2 models with H-flux so that the target geometry is generalised Kahler, it is necessary to work with a complexification of the sigma models. These issues are related to the obstructions to the existence of non-trivial twisted chiral superfields in Euclidean superspace.

  17. The evolving design of RTO ancillary service markets

    International Nuclear Information System (INIS)

    Isemonger, Alan G.

    2009-01-01

    Although the markets for ancillary services at the North American Independent System Operators are often structured in quite different ways there is an emerging set of core design elements that represent a rough consensus as to what the optimal design configuration for ancillary services should be, albeit with some regional variation. This paper looks back at how the design of ancillary services markets has recently evolved to put this development in context. Thereafter it examines the methods by which ancillary services are procured by highlighting the procurement practices at a number of different Independent System Operators, principally those in California, New York, New England, Texas and the PJM Interconnection, in an attempt to tease out the remaining reasons why the ancillary service markets are still so different. This is important as there are many innovations that are not rooted in regional differences but reflect genuine technical advances and economic efficiency gains and can be replicated across other ISOs to produce more efficient designs, greater reliability and lower costs. (author)

  18. Ancillary effects of selected acid deposition control policies

    Energy Technology Data Exchange (ETDEWEB)

    Moe, R.J.; Lyke, A.J.; Nesse, R.J.

    1986-08-01

    NAPAP is examining a number of potential ways to reduce the precursors (sulfur dioxide and nitrogen oxides) to acid deposition. However, the policies to reduce acid deposition will have other physical, biological and economic effects unrelated to acid deposition. For example, control policies that reduce sulfur dioxide emissions may also increase visibility. The effects of an acid deposition policy that are unrelated to acid deposition are referred to as ''ancillary'' effects. This reserch identifies and characterizes the principle physical and economic ancillary effects associated with acid deposition control and mitigation policies. In this study the ancillary benefits associated with four specific acid deposition policy options were investigated. The four policy options investigated are: (1) flue gas desulfurization, (2) coal blending or switching, (3) reductions in automobile emissions of NO/sub x/, and (4) lake liming. Potential ancillary benefits of each option were identified and characterized. Particular attention was paid to the literature on economic valuation of potential ancillary effects.

  19. Prevalence of influenza vaccination among nurses and ancillary workers in Italy: systematic review and meta analysis.

    Science.gov (United States)

    La Torre, Giuseppe; Mannocci, Alice; Ursillo, Paolo; Bontempi, Claudio; Firenze, Alberto; Panico, Maria Grazia; Sferrazza, Antonella; Ronga, Chiara; D'Anna, Adele; Amodio, Emanuele; Romano, Nino; Boccia, Antonio

    2011-07-01

    Italian Ministry of Health, recommends vaccination for seasonal influenza to all healthcare workers (HCW), particularly to nurses who have an important interaction with patients. The aim of this study is to conduct a systematic review in order to estimate the pooled prevalence of influenza vaccinations among nurses and ancillary workers in Italy and analyse the enhancing and hindering factors. The review was performed using 15 articles, six containing the prevalence of vaccination for nurses and ancillary workers, while the others qualitative analysis. In all the selected articles the score calculation has been carried out by using a protocol for observational studies. The nurses and ancillary workers pooled proportion of influenza vaccination was respectively 13.47% (95%CI 9.58-17.90%) and 12.52% (95%CI 9.97-15.31%). The Italian mean of influenza vaccination prevalence appear low if compared to other European countries, ranging from 15% to 29% in Countries such as UK, Germany, France. This situation of weakness should be seen as an opportunity to improve the vaccination rate for seasonal influenza significantly This should be done by intervening on the category which affirms caring less. In fact, this category has a priority to receive vaccination, due to their numbers and closer contact to patients. Research was conducted using medical database Scopus, PubMed, the search engine Google Scholar and ISI web of knowledge, and was concluded February 1st 2011.

  20. On the twist-2 and twist-3 contributions to the spin-dependent electroweak structure functions

    International Nuclear Information System (INIS)

    Bluemlein, J.; Kochelev, N.

    1997-01-01

    The twist-2 and twist-3 contributions of the polarized deep-inelastic structure functions are calculated both for neutral and charged current interactions using the operator product expansion in lowest order in QCD. The relations between the different structure functions are determined. New integral relations are derived between the twist-2 contributions of the structure functions g 3 (x,Q 2 ) and g 5 (x,Q 2 ) and between combinations of the twist-3 contributions to the structure functions g 2 (x,Q 2 ) and g 3 (x,Q 2 ). The sum rules for polarized deep-inelastic scattering are discussed in detail. (orig.)

  1. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

  2. Twisted covariant noncommutative self-dual gravity

    International Nuclear Information System (INIS)

    Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C.

    2008-01-01

    A twisted covariant formulation of noncommutative self-dual gravity is presented. The formulation for constructing twisted noncommutative Yang-Mills theories is used. It is shown that the noncommutative torsion is solved at any order of the θ expansion in terms of the tetrad and some extra fields of the theory. In the process the first order expansion in θ for the Plebanski action is explicitly obtained.

  3. Nonlinear physics of twisted magnetic field lines

    International Nuclear Information System (INIS)

    Yoshida, Zensho

    1998-01-01

    Twisted magnetic field lines appear commonly in many different plasma systems, such as magnetic ropes created through interactions between the magnetosphere and the solar wind, magnetic clouds in the solar wind, solar corona, galactic jets, accretion discs, as well as fusion plasma devices. In this paper, we study the topological characterization of twisted magnetic fields, nonlinear effect induced by the Lorentz back reaction, length-scale bounds, and statistical distributions. (author)

  4. OAM mode converter in twisted fibers

    DEFF Research Database (Denmark)

    Usuga Castaneda, Mario A.; Beltran-Mejia, Felipe; Cordeiro, Cristiano

    2014-01-01

    We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA.......We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA....

  5. Further Generalisations of Twisted Gabidulin Codes

    DEFF Research Database (Denmark)

    Puchinger, Sven; Rosenkilde, Johan Sebastian Heesemann; Sheekey, John

    2017-01-01

    We present a new family of maximum rank distance (MRD) codes. The new class contains codes that are neither equivalent to a generalised Gabidulin nor to a twisted Gabidulin code, the only two known general constructions of linear MRD codes.......We present a new family of maximum rank distance (MRD) codes. The new class contains codes that are neither equivalent to a generalised Gabidulin nor to a twisted Gabidulin code, the only two known general constructions of linear MRD codes....

  6. Loads Providing Ancillary Services: Review of International Experience

    Energy Technology Data Exchange (ETDEWEB)

    Heffner, Grayson; Goldman, Charles; Kintner-Meyer, Michael

    2007-05-01

    In this study, we examine the arrangements for and experiences of end-use loads providing ancillary services (AS) in five electricity markets: Australia, the United Kingdom (UK), the Nordic market, and the ERCOT and PJM markets in the United States. Our objective in undertaking this review of international experience was to identify specific approaches or market designs that have enabled customer loads to effectively deliver various ancillary services (AS) products. We hope that this report will contribute to the ongoing discussion in the U.S. and elsewhere regarding what institutional and technical developments are needed to ensure that customer loads can meaningfully participate in all wholesale electricity markets.

  7. 'Twisted tape sign': Its significance in recurrent sigmoid volvulus

    International Nuclear Information System (INIS)

    Gopal, K.; Lim, Y.; Banerjee, B.

    2005-01-01

    Aim: Sigmoid volvulus is a common cause of intestinal obstruction in the elderly. Mild attacks of sigmoid volvulus may be more difficult to diagnose due to the lack of severity of symptoms which may resolve spontaneously only to recur after an interval. This study was a review of patients to assess the incidence of the 'twisted tape sign' and to evaluate the significance of its presence in cases of recurrent sigmoid volvulus. Methods and materials: A retrospective study over eight years revealed six cases of surgically confirmed recurrent sigmoid volvulus. Case records and barium enemas of all patients were reviewed. Results: Six patients were identified, including four men and two women, with a median age of 56 years. Diagnostic difficulties were encountered in four (67%) patients with a delay ranging between 10 and 37 months with a mean 17.3 months. Twisted tape sign was confirmed on all barium examinations retrospectively. Conclusion: Recognition of twisted tape sign on barium enema examination along with an appropriate clinical history would suggest a diagnosis of recurrent sigmoid volvulus

  8. RESONANT ABSORPTION OF AXISYMMETRIC MODES IN TWISTED MAGNETIC FLUX TUBES

    Energy Technology Data Exchange (ETDEWEB)

    Giagkiozis, I.; Verth, G. [Solar Plasma Physics Research Centre, School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Hicks Building, Sheffield, S3 7RH (United Kingdom); Goossens, M.; Doorsselaere, T. Van [Centre for mathematical Plasma Astrophysics, Mathematics Department, KU Leuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Fedun, V. [Department of Automatic Control and Systems Engineering, University of Sheffield, Mappin Street, Amy Johnson Building, Sheffield, S1 3JD (United Kingdom)

    2016-06-01

    It has been shown recently that magnetic twist and axisymmetric MHD modes are ubiquitous in the solar atmosphere, and therefore the study of resonant absorption for these modes has become a pressing issue because it can have important consequences for heating magnetic flux tubes in the solar atmosphere and the observed damping. In this investigation, for the first time, we calculate the damping rate for axisymmetric MHD waves in weakly twisted magnetic flux tubes. Our aim is to investigate the impact of resonant damping of these modes for solar atmospheric conditions. This analytical study is based on an idealized configuration of a straight magnetic flux tube with a weak magnetic twist inside as well as outside the tube. By implementing the conservation laws derived by Sakurai et al. and the analytic solutions for weakly twisted flux tubes obtained recently by Giagkiozis et al. we derive a dispersion relation for resonantly damped axisymmetric modes in the spectrum of the Alfvén continuum. We also obtain an insightful analytical expression for the damping rate in the long wavelength limit. Furthermore, it is shown that both the longitudinal magnetic field and the density, which are allowed to vary continuously in the inhomogeneous layer, have a significant impact on the damping time. Given the conditions in the solar atmosphere, resonantly damped axisymmetric modes are highly likely to be ubiquitous and play an important role in energy dissipation. We also suggest that, given the character of these waves, it is likely that they have already been observed in the guise of Alfvén waves.

  9. The Latest Twists in Chromatin Remodeling.

    Science.gov (United States)

    Blossey, Ralf; Schiessel, Helmut

    2018-01-05

    In its most restrictive interpretation, the notion of chromatin remodeling refers to the action of chromatin-remodeling enzymes on nucleosomes with the aim of displacing and removing them from the chromatin fiber (the effective polymer formed by a DNA molecule and proteins). This local modification of the fiber structure can have consequences for the initiation and repression of the transcription process, and when the remodeling process spreads along the fiber, it also results in long-range effects essential for fiber condensation. There are three regulatory levels of relevance that can be distinguished for this process: the intrinsic sequence preference of the histone octamer, which rules the positioning of the nucleosome along the DNA, notably in relation to the genetic information coded in DNA; the recognition or selection of nucleosomal substrates by remodeling complexes; and, finally, the motor action on the nucleosome exerted by the chromatin remodeler. Recent work has been able to provide crucial insights at each of these three levels that add new twists to this exciting and unfinished story, which we highlight in this perspective. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Impact of advanced wind power ancillary services on power system

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit

    The objective of this report is to illustrate and analyse, by means of simulation test cases, the impact of wind power advanced ancillary services, like inertial response (IR), power oscillation damping (POD) and synchronising power (SP) on the power system. Generic models for wind turbine, wind...... power plant and power system are used in the investigation....

  11. Reduced risks and improved economic operation of ancillary services

    NARCIS (Netherlands)

    Bosch, van den P.P.J.; Jokic, A.; Hermans, R.M.; Frunt, J.; Kling, W.L.; Nobel, Frank; Boonekamp, P.; Boer, de W.W.

    2010-01-01

    Present arrangements and regulation for ancillary services for power balance in power systems cannot cope with future developments in power systems as the participants do not receive proper incentives for required behaviour. This paper analyzes the consequences of current arrangements for system

  12. Soft tissue twisting injuries of the knee

    International Nuclear Information System (INIS)

    Magee, T.; Shapiro, M.

    2001-01-01

    Twisting injuries occur as a result of differential motion of different tissue types in injuries with some rotational force. These injuries are well described in brain injuries but, to our knowledge, have not been described in the musculoskeletal literature. We correlated the clinical examination and MR findings of 20 patients with twisting injuries of the soft tissues around the knee. Design and patients: We prospectively followed the clinical courses of 20 patients with knee injuries who had clinical histories and MR findings to suggest twisting injuries of the subcutaneous tissues. Patients with associated internal derangement of the knee (i.e., meniscal tears, ligamentous or bone injuries) were excluded from this study. MR findings to suggest twisting injuries included linear areas of abnormal dark signal on T1-weighted sequences and abnormal bright signal on T2-weighted or short tau inversion recovery (STIR) sequences and/or signal to suggest hemorrhage within the subcutaneous tissues. These MR criteria were adapted from those established for indirect musculotendinous junction injuries. Results: All 20 patients presented with considerable pain that suggested internal derangement on physical examination by the referring orthopedic surgeons. All presented with injuries associated with rotational force. The patients were placed on a course of protected weight-bearing of the affected extremity for 4 weeks. All patients had pain relief by clinical examination after this period of protected weight-bearing. Twisting injuries of the soft tissues can result in considerable pain that can be confused with internal derangement of the knee on physical examination. Soft tissue twisting injuries need to be recognized on MR examinations as they may be the cause of the patient's pain despite no MR evidence of internal derangement of the knee. The demonstration of soft tissue twisting injuries in a patient with severe knee pain but no documented internal derangement on MR

  13. AIMES Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Daniel S [Univ. of Illinois, Urbana-Champaign, IL (United States). National Center for Supercomputing Applications (NCSA); Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States); Weissman, Jon [Univ. of Minnesota, Minneapolis, MN (United States); Turilli, Matteo [Rutgers Univ., New Brunswick, NJ (United States)

    2017-01-31

    This is the final technical report for the AIMES project. Many important advances in science and engineering are due to large-scale distributed computing. Notwithstanding this reliance, we are still learning how to design and deploy large-scale production Distributed Computing Infrastructures (DCI). This is evidenced by missing design principles for DCI, and an absence of generally acceptable and usable distributed computing abstractions. The AIMES project was conceived against this backdrop, following on the heels of a comprehensive survey of scientific distributed applications. AIMES laid the foundations to address the tripartite challenge of dynamic resource management, integrating information, and portable and interoperable distributed applications. Four abstractions were defined and implemented: skeleton, resource bundle, pilot, and execution strategy. The four abstractions were implemented into software modules and then aggregated into the AIMES middleware. This middleware successfully integrates information across the application layer (skeletons) and resource layer (Bundles), derives a suitable execution strategy for the given skeleton and enacts its execution by means of pilots on one or more resources, depending on the application requirements, and resource availabilities and capabilities.

  14. AIM Data Services

    Directory of Open Access Journals (Sweden)

    Michael Scholz

    2016-05-01

    Full Text Available AIM Data Services as a virtual facility provides virtual 3D reference tracks for simulation applications in the domain of automotive and railway systems. It offers tools for management and analysis of experiment data and a platform for survey and processing of vehicle data in the public transport domain. Collected spatial data is bundled in a database cluster and published through common web mapping interfaces.

  15. Twisted electron-acoustic waves in plasmas

    International Nuclear Information System (INIS)

    Aman-ur-Rehman; Ali, S.; Khan, S. A.; Shahzad, K.

    2016-01-01

    In the paraxial limit, a twisted electron-acoustic (EA) wave is studied in a collisionless unmagnetized plasma, whose constituents are the dynamical cold electrons and Boltzmannian hot electrons in the background of static positive ions. The analytical and numerical solutions of the plasma kinetic equation suggest that EA waves with finite amount of orbital angular momentum exhibit a twist in its behavior. The twisted wave particle resonance is also taken into consideration that has been appeared through the effective wave number q_e_f_f accounting for Laguerre-Gaussian mode profiles attributed to helical phase structures. Consequently, the dispersion relation and the damping rate of the EA waves are significantly modified with the twisted parameter η, and for η → ∞, the results coincide with the straight propagating plane EA waves. Numerically, new features of twisted EA waves are identified by considering various regimes of wavelength and the results might be useful for transport and trapping of plasma particles in a two-electron component plasma.

  16. AIMES Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States)

    2017-01-31

    Many important advances in science and engineering are due to large-scale distributed computing. Notwithstanding this reliance, we are still learning how to design and deploy large-scale production Distributed Computing Infrastructures (DCI). The AIMES project was conceived against this backdrop, following on the heels of a comprehensive survey of scienti c distributed applications [1]. The survey established, arguably for the rst time, the relationship between infrastructure and scienti c distributed applications. It examined well known contributors to the complexity associated with infrastructure, such as inconsistent internal and external interfaces, and demonstrated the correlation with application brittleness. It discussed how infrastructure complexity reinforces the challenges inherent in developing distributed applications.

  17. Review of Standby and Ancillary Services in the Context of Behind-the-Meter Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Holm, Alison [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-25

    The New Mexico Public Regulatory Commission (NMPRC) requested information on the following topics: Overview of ancillary and standby services. Examples of how ancillary and standby services are defined, used, and analyzed in other jurisdictions. Considerations regarding how ancillary and standby services may be economically valued. Background information on how ancillary and standby services differ from fixed costs to serve owners of behind-the-meter solar photovoltaic (BTM PV) systems.

  18. Electrically Controllable Magnetism in Twisted Bilayer Graphene.

    Science.gov (United States)

    Gonzalez-Arraga, Luis A; Lado, J L; Guinea, Francisco; San-Jose, Pablo

    2017-09-08

    Twisted graphene bilayers develop highly localized states around AA-stacked regions for small twist angles. We show that interaction effects may induce either an antiferromagnetic or a ferromagnetic (FM) polarization of said regions, depending on the electrical bias between layers. Remarkably, FM-polarized AA regions under bias develop spiral magnetic ordering, with a relative 120° misalignment between neighboring regions due to a frustrated antiferromagnetic exchange. This remarkable spiral magnetism emerges naturally without the need of spin-orbit coupling, and competes with the more conventional lattice-antiferromagnetic instability, which interestingly develops at smaller bias under weaker interactions than in monolayer graphene, due to Fermi velocity suppression. This rich and electrically controllable magnetism could turn twisted bilayer graphene into an ideal system to study frustrated magnetism in two dimensions.

  19. Aiming for the ordinary

    DEFF Research Database (Denmark)

    Offersen, Sara Marie Hebsgaard

    that the Danes are encouraged to be alert to still earlier and vaguer bodily signs of potential cancer and seek care ‘in time’. With biomedical constructions such as ‘cancer awareness’ and ‘alarm symptoms of cancer’ and the retrospectively oriented definition of life before symptoms-based healthcare seeking...... and articulation of bodily sensations, and how decisions about healthcare seeking are established in this context. This dissertation aims to explore these matters from the perspective of the Danish middle class, mainly focusing on how sensations are ascribed meaning as symptoms and how they are evoked...... on a continuum between what is locally considered ordinary and extraordinary. Overall, the dissertation argues that inquiries into morality and potentiality provide valuable insights into healthcare seeking practices and the making and management of symptoms in everyday life. The dissertation is based on 18...

  20. Higher-twist correlations in polarized hadrons

    International Nuclear Information System (INIS)

    Tangerman, R.D.

    1996-01-01

    In this thesis we studied the response of polarized hadrons to several high-energy probes, working in the framework of the field theoretic model. Emphasis is laid upon higher-twist effects such as quark transverse momentum. The inclusive DIS process is very well suited to study QCD. From general principles we were able to derive four positivity constraints on the structure functions without invoking the helicity formalism. The on-shell quark model is used to illustrate these constraints. Subseqeuently, we concentrated on the higher-twist structure function g 2 (x,Q 2 ). (orig./HSI)

  1. Factorising the 3D topologically twisted index

    Science.gov (United States)

    Cabo-Bizet, Alejandro

    2017-04-01

    We explore the path integration — upon the contour of hermitian (non-auxliary) field configurations — of topologically twisted N=2 Chern-Simons-matter theory (TTCSM) on {S}_2 times a segment. In this way, we obtain the formula for the 3D topologically twisted index, first as a convolution of TTCSM on {S}_2 times halves of {S}_1 , second as TTCSM on {S}_2 times {S}_1 — with a puncture, — and third as TTCSM on {S}_2× {S}_1 . In contradistinction to the first two cases, in the third case, the vector multiplet auxiliary field D is constrained to be anti-hermitian.

  2. A higher twist correction to heavy quark production

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Gunion, J.F.; Soper, D.E.

    1987-06-01

    The leading twist prediction for heavy quark production and a model for a higher twist correction that may be important for charm production was discussed. The correction arises from the interaction of the charm quark with spectator quarks

  3. The Effect of a Twisted Magnetic Field on the Phase Mixing of the Kink Magnetohydrodynamic Waves in Coronal Loops

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, Zanyar; Karami, Kayoomars [Department of Physics, University of Kurdistan, Pasdaran Street, P.O. Box 66177-15175, Sanandaj (Iran, Islamic Republic of); Soler, Roberto, E-mail: z.ebrahimi@uok.ac.ir [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain)

    2017-08-10

    There is observational evidence for the existence of a twisted magnetic field in the solar corona. This inspires us to investigate the effect of a twisted magnetic field on the evolution of magnetohydrodynamic (MHD) kink waves in coronal loops. With this aim, we solve the incompressible linearized MHD equations in a magnetically twisted nonuniform coronal flux tube in the limit of long wavelengths. Our results show that a twisted magnetic field can enhance or diminish the rate of phase mixing of the Alfvén continuum modes and the decay rate of the global kink oscillation depending on the twist model and the sign of the longitudinal ( k{sub z} ) and azimuthal ( m ) wavenumbers. Also, our results confirm that in the presence of a twisted magnetic field, when the sign of one of the two wavenumbers m and k {sub z} is changed, the symmetry with respect to the propagation direction is broken. Even a small amount of twist can have an important impact on the process of energy cascading to small scales.

  4. An examination of ongoing trends in airline ancillary revenues

    OpenAIRE

    Warnock-Smith, David; O'Connell, John Frankie; Maleki, Mahnaz

    2015-01-01

    The airline industry seems permanently embedded in producing thin margins and continuously combatting downward pressure on yields. To perpetuate the problem, the industry remains eclipsed with high cost structures and low barriers to entry. However, a new sizzling concept continues to counterbalance these effects in the form of ancillary revenues. Globally, these revenues have increased by 121% from 2010 to 2014 – and the trend is set to continue as carriers are quickly implementing structura...

  5. 77 FR 25105 - Reporting of Ancillary Airline Passenger Revenues

    Science.gov (United States)

    2012-04-27

    ...This document announces a public meeting on a Notice of Proposed Rulemaking (NPRM) issued on July 15, 2011. The NPRM proposed changes regarding reporting of airline ancillary passenger revenues, computation of mishandled baggage rates, and collection of separate statistics for mishandled wheelchairs and scooters used by passengers with disabilities. During the public meeting, DOT staff will provide a summary of the proposals in the NPRM and seek input on costs and benefits associated with the implementation of the proposals.

  6. [Aiming for zero blindness].

    Science.gov (United States)

    Nakazawa, Toru

    2015-03-01

    -independent factors, as well as our investigation of ways to improve the clinical evaluation of the disease. Our research was prompted by the multifactorial nature of glaucoma. There is a high degree of variability in the pattern and speed of the progression of visual field defects in individual patients, presenting a major obstacle for successful clinical trials. To overcome this, we classified the eyes of glaucoma patients into 4 types, corresponding to the 4 patterns of glaucomatous optic nerve head morphology described: by Nicolela et al. and then tested the validity of this method by assessing the uniformity of clinical features in each group. We found that in normal tension glaucoma (NTG) eyes, each disc morphology group had a characteristic location in which the loss of circumpapillary retinal nerve fiber layer thickness (cpRNFLT; measured with optical coherence tomography: OCT) was most likely to occur. Furthermore, the incidence of reductions in visual acuity differed between the groups, as did the speed of visual field loss, the distribution of defective visual field test points, and the location of test points that were most susceptible to progressive damage, measured by Humphrey static perimetry. These results indicate that Nicolela's method of classifying eyes with glaucoma was able to overcome the difficulties caused by the diverse nature of the disease, at least to a certain extent. Building on these findings, we then set out to identify sectors of the visual field that correspond to the distribution of retinal nerve fibers, with the aim of detecting glaucoma progression with improved sensitivity. We first mapped the statistical correlation between visual field test points and cpRNFLT in each temporal clock-hour sector (from 6 to 12 o'clock), using OCT data from NTG patients. The resulting series of maps allowed us to identify areas containing visual field test points that were prone to be affected together as a group. We also used a similar method to identify visual

  7. Impact of prenatal care provider on the use of ancillary health services during pregnancy

    Science.gov (United States)

    2013-01-01

    Background Recent declines in the provision of prenatal care by family physicians and the integration of midwives into the Canadian health care system have led to a shift in the pattern of prenatal care provision; however it is unknown if this also impacts use of other health services during pregnancy. This study aimed to assess the impact of the type of prenatal care provider on the self-reported use of ancillary services during pregnancy. Methods Data for this study was obtained from the All Our Babies study, a community-based prospective cohort study of women’s experiences during pregnancy and the post-partum period. Chi-square tests and logistic regression were used to assess the association between type of prenatal care provider and use of ancillary health services in pregnancy. Results During pregnancy, 85.8% of women reported accessing ancillary health services. Compared to women who received prenatal care from a family physician, women who saw a midwife were less likely to call a nurse telephone advice line (OR = 0.30, 95% CI: 0.18-0.50) and visit the emergency department (OR = 0.47, 95% CI: 0.24-0.89), but were more likely receive chiropractic care (OR = 4.07, 95% CI: 2.49-6.67). Women who received their prenatal care from an obstetrician were more likely to visit a walk-in clinic (OR = 1.51, 95% CI: 1.11-2.05) than those who were cared for by a family physician. Conclusions Prenatal care is a complex entity and referral pathways between care providers and services are not always clear. This can lead to the provision of fragmented care and create opportunities for errors and loss of information. All types of care providers have a role in addressing the full range of health needs that pregnant women experience. PMID:23497179

  8. Twist operators in N=4 beta-deformed theory

    NARCIS (Netherlands)

    de Leeuw, M.; Łukowski, T.

    2010-01-01

    In this paper we derive both the leading order finite size corrections for twist-2 and twist-3 operators and the next-to-leading order finite-size correction for twist-2 operators in beta-deformed SYM theory. The obtained results respect the principle of maximum transcendentality as well as

  9. Twisted Frobenius Identities from Vertex Operator Superalgebras

    Directory of Open Access Journals (Sweden)

    Alexander Zuevsky

    2017-01-01

    Full Text Available In consideration of the continuous orbifold partition function and a generating function for all n-point correlation functions for the rank two free fermion vertex operator superalgebra on the self-sewing torus, we introduce the twisted version of Frobenius identity.

  10. Magnetization Modeling of Twisted Superconducting Filaments

    CERN Document Server

    Satiramatekul, T; Devred, Arnaud; Leroy, Daniel

    2007-01-01

    This paper presents a new Finite Element numerical method to analyze the coupling between twisted filaments in a superconducting multifilament composite wire. To avoid the large number of elements required by a 3D code, the proposed method makes use of the energy balance principle in a 2D code. The relationship between superconductor critical current density and local magnetic flux density is implemented in the program for the Bean and modified Kim models. The modeled wire is made up of six filaments twisted together and embedded in a lowresistivity matrix. Computations of magnetization cycle and of the electric field pattern have been performed for various twist pitch values in the case of a pure copper matrix. The results confirm that the maximum magnetization depends on the matrix conductivity, the superconductor critical current density, the applied field frequency, and the filament twist pitch. The simulations also lead to a practical criterion for wire design that can be used to assess whether or not th...

  11. Hilbert's Grand Hotel with a series twist

    Science.gov (United States)

    Wijeratne, Chanakya; Mamolo, Ami; Zazkis, Rina

    2014-08-01

    This paper presents a new twist on a familiar paradox, linking seemingly disparate ideas under one roof. Hilbert's Grand Hotel, a paradox which addresses infinite set comparisons is adapted and extended to incorporate ideas from calculus - namely infinite series. We present and resolve several variations, and invite the reader to explore his or her own variations.

  12. On the Compton Twist-3 Asymmetries

    International Nuclear Information System (INIS)

    Korotkiyan, V.M.; Teryaev, O.V.

    1994-01-01

    The 'fermionic poles' contribution to the twist-3 single asymmetry in the gluon Compton process is calculated. The 'gluonic poles' existence seems to contradict the density matrix positivity. Qualitative predictions for the direct photon and jets asymmetries are presented. 13 refs., 2 figs

  13. Generalized Weyl modules for twisted current algebras

    Science.gov (United States)

    Makedonskyi, I. A.; Feigin, E. B.

    2017-08-01

    We introduce the notion of generalized Weyl modules for twisted current algebras. We study their representation-theoretic and combinatorial properties and also their connection with nonsymmetric Macdonald polynomials. As an application, we compute the dimension of the classical Weyl modules in the remaining unknown case.

  14. Hardy Inequalities in Globally Twisted Waveguides

    Czech Academy of Sciences Publication Activity Database

    Briet, Ph.; Hammedi, H.; Krejčiřík, David

    2015-01-01

    Roč. 105, č. 7 (2015), s. 939-958 ISSN 0377-9017 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : quantum waveguides * twisted tubes * Dirichlet Laplacian * Hardy inequality Subject RIV: BE - Theoretical Physics Impact factor: 1.517, year: 2015

  15. Modeling and development of a twisting wing using inductively heated shape memory alloy actuators

    Science.gov (United States)

    Saunders, Robert N.; Hartl, Darren J.; Boyd, James G.; Lagoudas, Dimitris C.

    2015-04-01

    Wing twisting has been shown to improve aircraft flight performance. The potential benefits of a twisting wing are often outweighed by the mass of the system required to twist the wing. Shape memory alloy (SMA) actuators repeatedly demonstrate abilities and properties that are ideal for aerospace actuation systems. Recent advances have shown an SMA torsional actuator that can be manufactured and trained with the ability to generate large twisting deformations under substantial loading. The primary disadvantage of implementing large SMA actuators has been their slow actuation time compared to conventional actuators. However, inductive heating of an SMA actuator allows it to generate a full actuation cycle in just seconds rather than minutes while still . The aim of this work is to demonstrate an experimental wing being twisted to approximately 10 degrees by using an inductively heated SMA torsional actuator. This study also considers a 3-D electromagnetic thermo-mechanical model of the SMA-wing system and compare these results to experiments to demonstrate modeling capabilities.

  16. Morphing wing structure with controllable twist based on adaptive bending-twist coupling

    Science.gov (United States)

    Raither, Wolfram; Heymanns, Matthias; Bergamini, Andrea; Ermanni, Paolo

    2013-06-01

    A novel semi-passive morphing airfoil concept based on variable bending-twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated.

  17. Morphing wing structure with controllable twist based on adaptive bending–twist coupling

    International Nuclear Information System (INIS)

    Raither, Wolfram; Heymanns, Matthias; Ermanni, Paolo; Bergamini, Andrea

    2013-01-01

    A novel semi-passive morphing airfoil concept based on variable bending–twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated. (paper)

  18. Optimal generator bidding strategies for power and ancillary services

    Science.gov (United States)

    Morinec, Allen G.

    As the electric power industry transitions to a deregulated market, power transactions are made upon price rather than cost. Generator companies are interested in maximizing their profits rather than overall system efficiency. A method to equitably compensate generation providers for real power, and ancillary services such as reactive power and spinning reserve, will ensure a competitive market with an adequate number of suppliers. Optimizing the generation product mix during bidding is necessary to maximize a generator company's profits. The objective of this research work is to determine and formulate appropriate optimal bidding strategies for a generation company in both the energy and ancillary services markets. These strategies should incorporate the capability curves of their generators as constraints to define the optimal product mix and price offered in the day-ahead and real time spot markets. In order to achieve such a goal, a two-player model was composed to simulate market auctions for power generation. A dynamic game methodology was developed to identify Nash Equilibria and Mixed-Strategy Nash Equilibria solutions as optimal generation bidding strategies for two-player non-cooperative variable-sum matrix games with incomplete information. These games integrated the generation product mix of real power, reactive power, and spinning reserve with the generators's capability curves as constraints. The research includes simulations of market auctions, where strategies were tested for generators with different unit constraints, costs, types of competitors, strategies, and demand levels. Studies on the capability of large hydrogen cooled synchronous generators were utilized to derive useful equations that define the exact shape of the capability curve from the intersections of the arcs defined by the centers and radial vectors of the rotor, stator, and steady-state stability limits. The available reactive reserve and spinning reserve were calculated given a

  19. Aerodynamic design of horizontal axis wind turbine with innovative local linearization of chord and twist distributions

    DEFF Research Database (Denmark)

    Tahani, Mojtaba; Kavari, Ghazale; Masdari, Mehran

    2017-01-01

    This study is aimed to aerodynamically design a 1 mega-Watt horizontal axis wind turbine in order to obtain the maximum power coefficient by linearizing the chord and twist distributions. A new linearization method has been used for chord and twist distributions by crossing tangent line through...... the geometry of the blades determines the power generated by rotor, designing the blade is a very important issue. Herein, calculations are done for different types of airfoil families namely Risø-A1-21, Risø-A1-18, S809, S814 and Du 93-W-210. Hence, the effect of selecting different airfoil families is also...

  20. Performance Assessment in a Heat Exchanger Tube with Opposite/Parallel Wing Twisted Tapes

    Directory of Open Access Journals (Sweden)

    S. Eiamsa-ard

    2015-02-01

    Full Text Available The thermohydraulic performance in a tube containing a modified twisted tape with alternate-axes and wing arrangements is reported. This work aims to investigate the effects of wing arrangements (opposite (O and parallel (P wings at different wing shapes (triangle (Tri, rectangular (Rec, and trapezoidal (Tra wings and on the thermohydraulic performance characteristics. The obtained results show that wing twisted tapes with all wing shape arrangements (O-Tri/O-Rec/O-Tra/P-Tri/P-Rec/P-Tra give superior thermohydraulic performance and heat transfer rate to the typical twisted tape. In addition, the tapes with opposite wing arrangement of O-Tra, O-Rec, and O-Tri give superior thermohydraulic performances to those with parallel wing arrangement of P-Tra, P-Rec, and P-Tri around 2.7%, 3.5%, and 3.2%, respectively.

  1. A novel role for Twist-1 in pulp homeostasis.

    Science.gov (United States)

    Galler, K M; Yasue, A; Cavender, A C; Bialek, P; Karsenty, G; D'Souza, R N

    2007-10-01

    The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.

  2. Urology Group Compensation and Ancillary Service Models in an Era of Value-based Care.

    Science.gov (United States)

    Shore, Neal D; Jacoby, Dana

    2016-01-01

    Changes involving the health care economic landscape have affected physicians' workflow, productivity, compensation structures, and culture. Ongoing Federal legislation regarding regulatory documentation and imminent payment-changing methodologies have encouraged physician consolidation into larger practices, creating affiliations with hospitals, multidisciplinary medical specialties, and integrated delivery networks. As subspecialization and evolution of care models have accelerated, independent medical groups have broadened ancillary service lines by investing in enterprises that compete with hospital-based (academic and nonacademic) entities, as well as non-physician- owned multispecialty enterprises, for both outpatient and inpatient services. The looming and dramatic shift from volume- to value-based health care compensation will assuredly affect urology group compensation arrangements and productivity formulae. For groups that can implement change rapidly, efficiently, and harmoniously, there will be opportunities to achieve the Triple Aim goals of the Patient Protection and Affordable Care Act, while maintaining a successful medical-financial practice. In summary, implementing new payment algorithms alongside comprehensive care coordination will assist urology groups in addressing the health economic cost and quality challenges that have been historically encountered with fee-for-service systems. Urology group leadership and stakeholders will need to adjust internal processes, methods of care coordination, cultural dependency, and organizational structures in order to create better systems of care and management. In response, ancillary services and patient throughput will need to evolve in order to adequately align quality measurement and reporting systems across provider footprints and patient populations.

  3. International Society of Gynecological Pathologists (ISGyP) Endometrial Cancer Project: Guidelines From the Special Techniques and Ancillary Studies Group.

    Science.gov (United States)

    Cho, Kathleen R; Cooper, Kumarasen; Croce, Sabrina; Djordevic, Bojana; Herrington, Simon; Howitt, Brooke; Hui, Pei; Ip, Philip; Koebel, Martin; Lax, Sigurd; Quade, Bradley J; Shaw, Patricia; Vidal, August; Yemelyanova, Anna; Clarke, Blaise; Hedrick Ellenson, Lora; Longacre, Teri A; Shih, Ie-Ming; McCluggage, W Glenn; Malpica, Anais; Oliva, Esther; Parkash, Vinita; Matias-Guiu, Xavier

    2018-04-11

    The aim of this article is to propose guidelines and recommendations in problematic areas in pathologic reporting of endometrial carcinoma (EC) regarding special techniques and ancillary studies. An organizing committee designed a comprehensive survey with different questions related to pathologic features, diagnosis, and prognosis of EC that was sent to all members of the International Society of Gynecological Pathologists. The special techniques/ancillary studies group received 4 different questions to be addressed. Five members of the group reviewed the literature and came up with recommendations and an accompanying text which were discussed and agreed upon by all members of the group. Twelve different recommendations are made. They address the value of immunohistochemistry, ploidy, and molecular analysis for assessing prognosis in EC, the value of steroid hormone receptor analysis to predict response to hormone therapy, and parameters regarding applying immunohistochemistry and molecular tests for assessing mismatch deficiency in EC.

  4. Ancillary procedure for early diagnosis of brain damage in children

    International Nuclear Information System (INIS)

    Sumi, Masatoshi; Sha, Tenei; Ryo, Fukko; Kagawa, Kotaro.

    1979-01-01

    CT scan of the head was performed on 14 patients with cerebral palsy, 16 with central coordination disorders, and 16 controls, and findings showing cerebral atrophy and enlargement of the cerebral ventricle were obtained in cases both of cerebral palsy and of central coordination disorders. To objectify these findings, 10 items were selected and evaluated according to 4 grades (0 - 3) and were compared. As a result, it was concluded that CT scan is an excellent ancillary procedure for early diagnosis of brain damages. (Tsunoda, M.)

  5. Transactive Control and Coordination of Distributed Assets for Ancillary Services

    Energy Technology Data Exchange (ETDEWEB)

    Subbarao, Krishnappa [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fuller, Jason C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kalsi, Karanjit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Somani, Abhishek [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, David P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-09-18

    The need to diversify energy supplies, the need to mitigate energy-related environmental impact, and the entry of electric vehicles in large numbers present challenges and opportunities to power system professionals. Wind and solar power provide many benefits, and to reap the benefits the resulting increased variability—forecasted as well as unforecasted—should be addressed. A majority of states and the District of Columbia, representing over half of the total load, have passed renewable portfolio standards. California’s plans call for 33% renewable energy by 2020. For grid balancing and for meeting reliability standards, ancillary services are needed. The needs for these services are poised to increase significantly. Demand resources are receiving increasing attention as one means of providing the ancillary services. Control and coordination of a large number (~millions) of distributed smart grid assets requires innovative approaches. One such approach is transactive control and coordination (TC2)—a distributed, hierarchical, agent-based incentive and control system. The TC2 paradigm is to create a market-like control system in which participation is voluntary and the participant sets the price for participation. For transactions that are frequent, automation of bids and responses is necessary. Such an approach has been developed and demonstrated at the Pacific Northwest National Laboratory. The devices, typically thermostatically controlled heating, ventilating, and air conditioning (HVAC) loads, send their bids—the quantity of energy they need and, based on the consumer preferences encoded in a simple user interface, the price they are willing to pay. The typical bid period is 5 minutes. By aggregating all the bids, a demand curve is generated by the aggregating entity, and matched with a supply curve or supply constraint. The aggregator transmits the clearing price to the devices. The winning devices proceed to consume the energy they bid for and won

  6. A New Twisting Somersault: 513XD

    Science.gov (United States)

    Tong, William; Dullin, Holger R.

    2017-12-01

    We present the mathematical framework of an athlete modelled as a system of coupled rigid bodies to simulate platform and springboard diving. Euler's equations of motion are generalised to non-rigid bodies and are then used to innovate a new dive sequence that in principle can be performed by real-world athletes. We begin by assuming that shape changes are instantaneous so that the equations of motion simplify enough to be solved analytically, and then use this insight to present a new dive (513XD) consisting of 1.5 somersaults and five twists using realistic shape changes. Finally, we demonstrate the phenomenon of converting pure somersaulting motion into pure twisting motion by using a sequence of impulsive shape changes, which may have applications in other fields such as space aeronautics.

  7. Chiral tunneling in a twisted graphene bilayer.

    Science.gov (United States)

    He, Wen-Yu; Chu, Zhao-Dong; He, Lin

    2013-08-09

    The perfect transmission in a graphene monolayer and the perfect reflection in a Bernal graphene bilayer for electrons incident in the normal direction of a potential barrier are viewed as two incarnations of the Klein paradox. Here we show a new and unique incarnation of the Klein paradox. Owing to the different chiralities of the quasiparticles involved, the chiral fermions in a twisted graphene bilayer show an adjustable probability of chiral tunneling for normal incidence: they can be changed from perfect tunneling to partial or perfect reflection, or vice versa, by controlling either the height of the barrier or the incident energy. As well as addressing basic physics about how the chiral fermions with different chiralities tunnel through a barrier, our results provide a facile route to tune the electronic properties of the twisted graphene bilayer.

  8. Factorising the 3D topologically twisted index

    Energy Technology Data Exchange (ETDEWEB)

    Cabo-Bizet, Alejandro [Instituto de Astronomía y Física del Espacio (CONICET-UBA),Ciudad Universitaria, C.P. 1428, Buenos Aires (Argentina)

    2017-04-20

    We explore the path integration — upon the contour of hermitian (non-auxliary) field configurations — of topologically twisted N=2 Chern-Simons-matter theory (TTCSM) on S{sub 2} times a segment. In this way, we obtain the formula for the 3D topologically twisted index, first as a convolution of TTCSM on S{sub 2} times halves of S{sub 1}, second as TTCSM on S{sub 2} times S{sub 1} — with a puncture, — and third as TTCSM on S{sub 2}×S{sub 1}. In contradistinction to the first two cases, in the third case, the vector multiplet auxiliary field D is constrained to be anti-hermitian.

  9. IRONY IN CHARLES DICKEN'S OLIVER TWIST

    Directory of Open Access Journals (Sweden)

    Ika Kana Trisnawati

    2016-05-01

    Full Text Available This paper describes the types of irony used by Charles Dickens in his notable early work, Oliver Twist, as well as the reasons the irony was chosen. As a figurative language, irony is utilized to express one’s complex feelings without truly saying them. In Oliver Twist, Dickens brought the readers some real social issues wrapped in dark, deep written expressions of irony uttered by the characters of his novel. Undoubtedly, the novel had left an impact to the British society at the time. The irony Dickens displayed here includes verbal, situational, and dramatic irony. His choice of irony made sense as he intended to criticize the English Poor Laws and to touch the public sentiment. He wanted to let the readers go beyond what was literally written and once they discovered what the truth was, they would eventually understand Dickens’ purposes.

  10. Leibniz algebroids, twistings and exceptional generalized geometry

    Science.gov (United States)

    Baraglia, D.

    2012-05-01

    We investigate a class of Leibniz algebroids which are invariant under diffeomorphisms and symmetries involving collections of closed forms. Under appropriate assumptions we arrive at a classification which in particular gives a construction starting from graded Lie algebras. In this case the Leibniz bracket is a derived bracket and there are higher derived brackets resulting in an L∞-structure. The algebroids can be twisted by a non-abelian cohomology class and we prove that the twisting class is described by a Maurer-Cartan equation. For compact manifolds we construct a Kuranishi moduli space of this equation which is shown to be affine algebraic. We explain how these results are related to exceptional generalized geometry.

  11. Valve-aided twisted Savonius rotor

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Rajkumar, M.; Saha, U.K.

    2006-05-15

    Accessories, such as end plates, deflecting plates, shielding and guide vanes, may increase the power of a Savonius rotor, but make the system structurally complex. In such cases, the rotor can develop a relatively large torque at small rotational speeds and is cheap to build, however it harnesses only a small fraction of the incident wind energy. Another proposition for increasing specific output is to place non-return valves inside the concave side of the blades. Such methods have been studied experimentally with a twisted-blade Thus improving a Savonius rotor's energy capture. This new concept has been named as the 'Valve-Aided Twisted Savonius'rotor. Tests were conducted in a low-speed wind tunnel to evaluate performance. This mechanism is found to be independent of flow direction, and shows potential for large machines. [Author].

  12. Chiral Tunnelling in Twisted Graphene Bilayer

    OpenAIRE

    He, Wen-Yu; Chu, Zhao-Dong; He, Lin

    2013-01-01

    The perfect transmission in graphene monolayer and the perfect reflection in Bernal graphene bilayer for electrons incident in the normal direction of a potential barrier are viewed as two incarnations of the Klein paradox. Here we show a new and unique incarnation of the Klein paradox. Owing to the different chiralities of the quasiparticles involved, the chiral fermions in twisted graphene bilayer shows adjustable probability of chiral tunnelling for normal incidence: they can be changed fr...

  13. Vacuum expectation value of twist fields

    Science.gov (United States)

    Belitsky, A. V.

    2017-09-01

    Twist fields emerge in a number of physical applications ranging from entanglement entropy to scattering amplitudes in four-dimensional gauge theories. In this work, their vacuum expectation values are studied in the path integral framework. By performing a gauge transformation, their correlation functions are reduced to field theory of matter fields in external Aharonov-Bohm vortices. The resulting functional determinants are then analyzed within the zeta-function regularization for the spectrum of Bessel zeros, and concise formulas are derived.

  14. Leibniz algebroids, twistings and exceptional generalized geometry

    OpenAIRE

    Baraglia, David

    2011-01-01

    We investigate a class of Leibniz algebroids which are invariant under diffeomorphisms and symmetries involving collections of closed forms. Under appropriate assumptions we arrive at a classification which in particular gives a construction starting from graded Lie algebras. In this case the Leibniz bracket is a derived bracket and there are higher derived brackets resulting in an $L_\\infty$-structure. The algebroids can be twisted by a non-abelian cohomology class and we prove that the twis...

  15. Exploring exotic states with twisted boundary conditions

    International Nuclear Information System (INIS)

    Agadjanov, Dimitri

    2017-01-01

    he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

  16. Exploring exotic states with twisted boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Agadjanov, Dimitri

    2017-09-11

    he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

  17. MAML1 and TWIST1 co-overexpression promote invasion of head and neck squamous cell carcinoma.

    Science.gov (United States)

    Ardalan Khales, Sima; Ebrahimi, Ehsan; Jahanzad, Eisa; Ardalan Khales, Sahar; Forghanifard, Mohammad Mahdi

    2018-01-15

    Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with considerable morbidity and mortality. Invasion and metastasis of HNSCC is a complex process involving multiple molecules and signaling pathways. Twist Family BHLH Transcription Factor 1 (TWIST1) and Mastermind-like 1 (MAML1) are essential in induction of epithelial-mesenchymal transition through direct regulation of implicated molecules in cellular adhesion, migration and invasion. Our aim in this study was to assess the clinical significance of MAML1 and TWIST1 expression in HNSCC, and elucidate the probable correlation between these genes to exhibit their possible associations with progression and metastasis of the disease. The gene expression profile of MAML1 and TWIST1 was assessed in fresh tumoral compared to distant tumor-free tissues of 55 HNSCC patients using quantitative real-time Polymerase chain reaction (PCR). Significant overexpression of MAML1 and TWIST1 mRNA was observed in 49.1% and 38.2% (P ˂ 0.05) of tumor specimens, respectively. Overexpression of MAML1 was associated with vascular invasion (P = 0.048). Concomitant overexpression of MAML1 and TWIST1 was significantly correlated to each other (P = 0.004). Co-overexpression of the genes was significantly correlated to the various clinicopathological indices of poor prognosis including depth of tumor invasion (P < 0.01), lymphatic invasion and grade of tumor cell differentiation (P < 0.05). Significant correlation between MAML1 and TWIST1 in HNSCC was revealed. This study was the first report elucidating MAML1 clinical relevance in HNSCC. These new findings suggest an oncogenic role for concomitant expression of MAML1 and TWIST1 genes in HNSCC invasion and metastasis. © 2018 John Wiley & Sons Australia, Ltd.

  18. Ancillary services and optimal household energy management with photovoltaic production

    International Nuclear Information System (INIS)

    Clastres, C.; Ha Pham, T.T.; Wurtz, F.; Bacha, S.

    2010-01-01

    This article presents a project designed to increase the monetary value of photovoltaic (PV) solar production for residential applications. To contribute to developing new functionalities for this type of PV system and an efficient control system for optimising its operation, this article explains how the proposed system could contract to provide ancillary services, particularly the supply of active power services. This provision of service by a PV-based system for domestic applications, not currently available, has prompted a market design proposal related to the distribution system. The mathematical model for calculating the system's optimal operation (sources, load and exchanges of power with the grid) results in a linear mix integer optimisation problem in which the objective is to maximise the profits achieved by taking part in the electricity market. Our approach is illustrated in a case study. PV producers could gain by taking part in the markets for balancing power or ancillary services despite the negative impact on profit of several types of uncertainty, notably the intermittent nature of the PV source.

  19. Design optimization for active twist rotor blades

    Science.gov (United States)

    Mok, Ji Won

    This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to

  20. Simulating QCD at the physical point with Nf=2 Wilson twisted mass fermions at maximal twist

    International Nuclear Information System (INIS)

    Abdel-Rehim, A.; Alexandrou, C.; Cyprus Univ. Nicosia; Burger, F.

    2015-12-01

    We present simulations of QCD using N f =2 dynamical Wilson twisted mass lattice QCD with physical value of the pion mass and at one value of the lattice spacing. Such simulations at a∼0.09 fm became possible by adding the clover term to the action. While O(a) improvement is still guaranteed by Wilson twisted mass fermions at maximal twist, the introduction of the clover term reduces O(a 2 ) cutoff effects related to isospin symmetry breaking. We give results for a set of phenomenologically interesting observables like pseudo-scalar masses and decay constants, quark masses and the anomalous magnetic moments of leptons. We mostly find remarkably good agreement with phenomenology, even though we cannot take the continuum and thermodynamic limits.

  1. Ten helical twist angles of B-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Kabsch, W; Sander, C; Trifonov, E N

    1982-01-01

    On the assumption that the twist angles between adjacent base-pairs in the DNA molecule are additive a linear system of 40 equations was derived from experimental measurements of the total twist angles for different pieces of DNA of known sequences. This system of equations is found to be statistically consistent providing a solution for all ten possible twist angles of B-DNA by a least squares fitting procedure. Four of the calculated twist angles were not known before. The other six twist angles calculated are very close to the experimentally measured ones. The data used were obtained by the electrophoretic band-shift method, crystallography and nuclease digestion of DNA adsorbed to mica or Ca-phosphate surface. The validity of the principle of additivity of the twist angles implies that the angle between any particular two base-pairs is a function of only these base-pairs, independent of nearest neighbors.

  2. Maximally twisted mass lattice QCD at the physical pion mass

    International Nuclear Information System (INIS)

    Kostrzewa, Bartosz

    2016-01-01

    In computer simulations of Lattice Quantum Chromodynamics, the usage of unphysically large quark masses and the subsequent extrapolation of results to the physical value of the quark masses are major sources of systematic uncertainty. In this thesis, the feasibility and practicality of numerical simulations of Quantum Chromodynamics with physically light up and down quarks using the Wilson twisted mass quark discretisation are explored. Working in this regime is complicated firstly by the numerical expense of these simulations and secondly by the presence of potentially large lattice artefacts. The twisted mass discretisation is affected by an unphysical mass difference between the charged and neutral pions, rendering simulations at the physical charged pion mass infeasible if this mass splitting is too large. With the aim of reducing it, the Sheikholeslami-Wohlert term is added to the twisted mass fermion action and simulations with mass degenerate up and down quarks are then performed as a proof of concept. It is demonstrated that these simulations are stable and that the parameters of the lattice theory can be successfully tuned to correspond to the physical charged pion mass. Subsequently, the parameter tuning for simulations with mass degenerate up and down quarks as well as strange and charm quarks is explored and it is shown that it can be carried out in steps. As benchmark observables, the masses and decay constants of pseudoscalar mesons with light, strange and charm valence quarks are calculated and seen to largely reproduce their phenomenological values, even though continuum and infinite volume extrapolations are not performed. Light, strange and charm quark mass estimates are determined based on this data and also seen to coincide with phenomenological and other lattice determinations. In this analysis, a particular emphasis is placed on the systematic error due to the choice of fit range for pseudoscalar correlation functions and a weighting method is

  3. Ancillary Services for the European Grid with High Shares of Wind and Solar Power

    DEFF Research Database (Denmark)

    Van Hulle, Frans; Holttinen, Hannele; Kiviluoma, Juha

    2012-01-01

    to be better understood. This relates both to the technical capabilities of the plants for delivering specific services and to the quantification of the needs. The paper presents the approach of the European IEE project REserviceS, aiming at establishing reference guidance for the ongoing developments......With significantly increasing share of variable renewable power generation like wind and solar PV, the need in the power system for ancillary services supporting the network frequency, voltage, etc. changes. Turning this issue around, market opportunities will emerge for wind and solar PV...... technology to deliver such grid services. In the European power system, adequate market mechanisms need to be developed to ensure that there will be an efficient trading of these services. For that purpose a range of (economic) characteristics of wind (and solar) power as providers of grid services need...

  4. Twisted Vanes Would Enhance Fuel/Air Mixing In Turbines

    Science.gov (United States)

    Nguyen, H. Lee; Micklow, Gerald J.; Dogra, Anju S.

    1994-01-01

    Computations of flow show performance of high-shear airblast fuel injector in gas-turbine engine enhanced by use of appropriately proportioned twisted (instead of flat) dome swirl vanes. Resultant more nearly uniform fuel/air mixture burns more efficiently, emitting smaller amounts of nitrogen oxides. Twisted-vane high-shear airblast injectors also incorporated into paint sprayers, providing advantages of low pressure drop characteristic of airblast injectors in general and finer atomization of advanced twisted-blade design.

  5. Twisted rudder for reducing fuel-oil consumption

    Directory of Open Access Journals (Sweden)

    Jung-Hun Kim

    2014-09-01

    Full Text Available Three twisted rudders fit for large container ships have been developed; 1 the Z-twisted rudder that is an asymmetry type taking into consideration incoming flow angles of the propeller slipstream, 2 the ZB-twisted rudder with a rudder bulb added onto the Z-twisted rudder, and 3 the ZB-F twisted rudder with a rudder fin attached to the ZB-twisted rudder. The twisted rudders have been designed computationally with the hydrodynamic characteristics in a self-propulsion condition in mind. The governing equation is the Navier-Stokes equations in an unsteady turbulent flow. The turbulence model applied is the Reynolds stress. The calculation was carried out in towing and self-propulsion conditions. The sliding mesh technique was employed to simulate the flow around the propeller. The speed performances of the ship with the twisted rudders were verified through model tests in a towing tank. The twisted versions showed greater performance driven by increased hull efficiency from less thrust deduction fraction and more effective wake fraction and decreased propeller rotating speed.

  6. Higher twist contributions to deep-inelastic structure functions

    International Nuclear Information System (INIS)

    Bluemlein, J.; Boettcher, H.

    2008-07-01

    We report on a recent extraction of the higher twist contributions to the deep inelastic structure functions F ep,ed 2 (x,Q 2 ) in the large x region. It is shown that the size of the extracted higher twist contributions is strongly correlated with the higher order corrections applied to the leading twist part. A gradual lowering of the higher twist contributions going from NLO to N 4 LO is observed, where in the latter case only the leading large x terms were considered. (orig.)

  7. Twisted sigma-model solitons on the quantum projective line

    Science.gov (United States)

    Landi, Giovanni

    2018-04-01

    On the configuration space of projections in a noncommutative algebra, and for an automorphism of the algebra, we use a twisted Hochschild cocycle for an action functional and a twisted cyclic cocycle for a topological term. The latter is Hochschild-cohomologous to the former and positivity in twisted Hochschild cohomology results into a lower bound for the action functional. While the equations for the critical points are rather involved, the use of the positivity and the bound by the topological term lead to self-duality equations (thus yielding twisted noncommutative sigma-model solitons, or instantons). We present explicit nontrivial solutions on the quantum projective line.

  8. Bound states on the lattice with partially twisted boundary conditions

    International Nuclear Information System (INIS)

    Agadjanov, D.; Guo, F.-K.; Ríos, G.; Rusetsky, A.

    2015-01-01

    We propose a method to study the nature of exotic hadrons by determining the wave function renormalization constant Z from lattice simulations. It is shown that, instead of studying the volume-dependence of the spectrum, one may investigate the dependence of the spectrum on the twisting angle, imposing twisted boundary conditions on the fermion fields on the lattice. In certain cases, e.g., the case of the DK bound state which is addressed in detail, it is demonstrated that the partial twisting is equivalent to the full twisting up to exponentially small corrections.

  9. Fatigue Behaviors of Materials Processed by Planar Twist Extrusion

    Science.gov (United States)

    Ebrahimi, Mahmoud

    2017-12-01

    Since the last decade, the fabrication of ultrafine grain and nanostructure metals and alloys has attracted much attention in the field of materials engineering. The present study aimed at experimentally investigating the fatigue properties that are of great importance in dynamic structures before and after the planar twist extrusion process for both commercially pure copper and 6061 aluminum alloy. The results indicated that the yield strength, tensile strength, hardness, and fatigue endurance of copper increased by about 398, 122, 198, and 183 pct, respectively, while they improved by about 429, 212, 227, and 148 pct, respectively, in aluminum alloy as compared to the initial conditions. The stress-strain curves displayed sizable reduction of strain hardening. Furthermore, grain-size correction factors based on the empirical results were introduced to include the effect of the grain-size effect on both low and high-cycle fatigue strengths of the material.

  10. Parametric study on kink instabilities of twisted magnetic flux ropes in the solar atmosphere

    Science.gov (United States)

    Mei, Z. X.; Keppens, R.; Roussev, I. I.; Lin, J.

    2018-01-01

    Aims: Twisted magnetic flux ropes (MFRs) in the solar atmosphere have been researched extensively because of their close connection to many solar eruptive phenomena, such as flares, filaments, and coronal mass ejections (CMEs). In this work, we performed a set of 3D isothermal magnetohydrodynamic (MHD) numerical simulations, which use analytical twisted MFR models and study dynamical processes parametrically inside and around current-carrying twisted loops. We aim to generalize earlier findings by applying finite plasma β conditions. Methods: Inside the MFR, approximate internal equilibrium is obtained by pressure from gas and toroidal magnetic fields to maintain balance with the poloidal magnetic field. We selected parameter values to isolate best either internal or external kink instability before studying complex evolutions with mixed characteristics. We studied kink instabilities and magnetic reconnection in MFRs with low and high twists. Results: The curvature of MFRs is responsible for a tire tube force due to its internal plasma pressure, which tends to expand the MFR. The curvature effect of toroidal field inside the MFR leads to a downward movement toward the photosphere. We obtain an approximate internal equilibrium using the opposing characteristics of these two forces. A typical external kink instability totally dominates the evolution of MFR with infinite twist turns. Because of line-tied conditions and the curvature, the central MFR region loses its external equilibrium and erupts outward. We emphasize the possible role of two different kink instabilities during the MFR evolution: internal and external kink. The external kink is due to the violation of the Kruskal-Shafranov condition, while the internal kink requires a safety factor q = 1 surface inside the MFR. We show that in mixed scenarios, where both instabilities compete, complex evolutions occur owing to reconnections around and within the MFR. The S-shaped structures in current distributions

  11. Twisting and Writhing with George Ellery Hale

    Science.gov (United States)

    Canfield, Richard C.

    2013-06-01

    Early in his productive career in astronomy, George Ellery Hale developed innovative solar instrumentation that allowed him to make narrow-band images. Among the solar phenomena he discovered were sunspot vortices, which he attributed to storms akin to cyclones in our own atmosphere. Using the concept of magnetic helicity, physicists and mathematicians describe the topology of magnetic fields, including twisting and writhing. Our contemporary understanding of Hale's vortices as a consequence of large-scale twist in sunspot magnetic fields hinges on a key property of helicity: conservation. I will describe the critical role that this property plays, when applied to twist and writhe, in a fundamental aspect of global solar magnetism: the hemispheric and solar cycle dependences of active region electric currents with respect to magnetic fields. With the advent of unbroken sequences of high-resolution magnetic images, such as those presently available from the Helioseismic and Magnetic Imager on Solar Dynamics Observatory, the flux of magnetic helicity through the photosphere can be observed quantitatively. As magnetic flux tubes buoy up through the convection zone, buffeted and shredded by turbulence, they break up into fragments by repeated random bifurcation. We track these rising flux fragments in the photosphere, and calculate the flux of energy and magnetic helicity there. Using a quantitative model of coronal currents, we also track connections between these fragments to calculate the energy and magnetic helicity stored at topological interfaces that are in some ways analogous to the storage of stress at faults in the Earth's crust. Comparison of these values to solar flares and interplanetary coronal mass ejections implies that this is the primary storage mechanism for energy and magnetic helicity released in those phenomena, and suggests a useful tool for quantitative prediction of geomagnetic storms.

  12. Energy and ancillary service dispatch through dynamic optimal power flow

    International Nuclear Information System (INIS)

    Costa, A.L.; Costa, A. Simoes

    2007-01-01

    This paper presents an approach based on dynamic optimal power flow (DOPF) to clear both energy and spinning reserve day-ahead markets. A competitive environment is assumed, where agents can offer active power for both demand supply and ancillary services. The DOPF jointly determines the optimal solutions for both energy dispatch and reserve allocation. A non-linear representation for the electrical network is employed, which is able to take transmission losses and power flow limits into account. An attractive feature of the proposed approach is that the final optimal solution will automatically meet physical constraints such as generating limits and ramp rate restrictions. In addition, the proposed framework allows the definition of multiple zones in the network for each time interval, in order to ensure a more adequate distribution of reserves throughout the power system. (author)

  13. Optical twists in phase and amplitude

    DEFF Research Database (Denmark)

    Daria, Vincent R.; Palima, Darwin; Glückstad, Jesper

    2011-01-01

    where both phase and amplitude express a helical profile as the beam propagates in free space. Such a beam can be accurately referred to as an optical twister. We characterize optical twisters and demonstrate their capacity to induce spiral motion on particles trapped along the twisters’ path. Unlike LG...... beams, the far field projection of the twisted optical beam maintains a high photon concentration even at higher values of topological charge. Optical twisters have therefore profound applications to fundamental studies of light and atoms such as in quantum entanglement of the OAM, toroidal traps...

  14. NMSBA - Twist Resist - Rotational Exercise Module

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Aaron [Twist Resist, Albuquerque, NM (United States); Reece, Blake D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Berger, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guido, Steven Frank [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Linker, Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-08-01

    This report contains a summary of the work completed to develop a modular, rotational exercise device. In the report are images, diagrams, and explanations of the efforts contributed to the project since its inception. The purpose of this document is to provide a walk-through of the progress on this project, from the initial design concepts to the final design and work done, so that the customer (Twist Resist), or individuals/firms who work on this project in the future will have a springboard of ideas/concepts to work from.

  15. Processing mechanics of alternate twist ply (ATP) yarn technology

    Science.gov (United States)

    Elkhamy, Donia Said

    Ply yarns are important in many textile manufacturing processes and various applications. The primary process used for producing ply yarns is cabling. The speed of cabling is limited to about 35m/min. With the world's increasing demands of ply yarn supply, cabling is incompatible with today's demand activated manufacturing strategies. The Alternate Twist Ply (ATP) yarn technology is a relatively new process for producing ply yarns with improved productivity and flexibility. This technology involves self plying of twisted singles yarn to produce ply yarn. The ATP process can run more than ten times faster than cabling. To implement the ATP process to produce ply yarns there are major quality issues; uniform Twist Profile and yarn Twist Efficiency. The goal of this thesis is to improve these issues through process modeling based on understanding the physics and processing mechanics of the ATP yarn system. In our study we determine the main parameters that control the yarn twist profile. Process modeling of the yarn twist across different process zones was done. A computational model was designed to predict the process parameters required to achieve a square wave twist profile. Twist efficiency, a measure of yarn torsional stability and bulk, is determined by the ratio of ply yarn twist to singles yarn twist. Response Surface Methodology was used to develop the processing window that can reproduce ATP yarns with high twist efficiency. Equilibrium conditions of tensions and torques acting on the yarns at the self ply point were analyzed and determined the pathway for achieving higher twist efficiency. Mechanistic modeling relating equilibrium conditions to the twist efficiency was developed. A static tester was designed to zoom into the self ply zone of the ATP yarn. A computer controlled, prototypic ATP machine was constructed and confirmed the mechanistic model results. Optimum parameters achieving maximum twist efficiency were determined in this study. The

  16. Capabilities and costs for ancillary services provision by wind power plants. Deliverable D 3.1

    DEFF Research Database (Denmark)

    Faiella, Mariano; Hennig, Tobias; Cutululis, Nicolaos Antonio

    This report is the deliverable of the third work package of the REserviceS project and describes the technical options and related costs for the provision of ancillary services specifically from wind energy technologies. It is focused on the set of ancillary services defined in the previous work...

  17. Use of Ancillary Tests When Determining Brain Death in Pediatric Patients in the United States.

    Science.gov (United States)

    Lewis, Ariane; Adams, Nellie; Chopra, Arun; Kirschen, Matthew P

    2017-10-01

    Although pediatric brain death guidelines stipulate when ancillary testing should be used during brain death determination, little is known about the way these recommendations are implemented in clinical practice. We conducted a survey of pediatric intensivists and neurologists in the United States on the use of ancillary testing. Although most respondents noted they only performed an ancillary test if the clinical examination and apnea test could not be completed, 20% of 195 respondents performed an ancillary test for other reasons, including (1) to convince a family that objected to the brain death determination that a patient is truly dead (n = 21), (2) personal preference (n = 14), and (3) institutional requirement (n = 5). Our findings suggest that pediatricians use ancillary tests for a variety of reasons during brain death determination. Medical societies and governmental regulatory bodies must reinforce the need for homogeneity in practice.

  18. On reflection algebras and twisted Yangians

    International Nuclear Information System (INIS)

    Doikou, Anastasia

    2005-01-01

    It is well known that integrable models associated to rational R matrices give rise to certain non-Abelian symmetries known as Yangians. Analogously boundary symmetries arise when general but still integrable boundary conditions are implemented, as originally argued by Delius, Mackay, and Short from the field theory point of view, in the context of the principal chiral model on the half-line. In the present study we deal with a discrete quantum mechanical system with boundaries, that is the N site gl(n) open quantum spin chain. In particular, the open spin chain with two distinct types of boundary condition known as soliton preserving and soliton nonpreserving is considered. For both types of boundaries we present a unified framework for deriving the corresponding boundary nonlocal charges directly at the quantum level. The nonlocal charges are simply coproduct realizations of particular boundary quantum algebras called boundary or twisted Yangians, depending on the choice of boundary conditions. Finally, with the help of linear intertwining relations between the solutions of the reflection equation and the generators of the boundary or twisted Yangians we are able to exhibit the exact symmetry of the open spin chain, namely we show that a number of the boundary nonlocal charges are in fact conserved quantities

  19. How the embryonic brain tube twists

    Science.gov (United States)

    Chen, Zi; Guo, Qiaohang; Forsch, Nickolas; Taber, Larry

    2014-03-01

    During early development, the tubular brain of the chick embryo undergoes a combination of progressive ventral bending and rightward torsion. This deformation is one of the major organ-level symmetry-breaking events in development. Available evidence suggests that bending is caused by differential growth, but the mechanism for torsion remains poorly understood. Since the heart almost always loops in the same direction that the brain twists, researchers have speculated that heart looping affects the direction of brain torsion. However, direct evidence is virtually nonexistent, nor is the mechanical origin of such torsion understood. In our study, experimental perturbations show that the bending and torsional deformations in the brain are coupled and that the vitelline membrane applies an external load necessary for torsion to occur. In addition, the asymmetry of the looping heart gives rise to the chirality of the twisted brain. A computational model is used to interpret these findings. Our work clarifies the mechanical origins of brain torsion and the associated left-right asymmetry, reminiscent of D'Arcy Thompson's view of biological form as ``diagram of forces''.

  20. Drag Performance of Twist Morphing MAV Wing

    Directory of Open Access Journals (Sweden)

    Ismail N.I.

    2016-01-01

    Full Text Available Morphing wing is one of latest evolution found on MAV wing. However, due to few design problems such as limited MAV wing size and complicated morphing mechanism, the understanding of its aerodynamic behaviour was not fully explored. In fact, the basic drag distribution induced by a morphing MAV wing is still remained unknown. Thus, present work is carried out to compare the drag performance between a twist morphing wing with membrane and rigid MAV wing design. A quasi-static aeroelastic analysis by using the Ansys-Fluid Structure Interaction (FSI method is utilized in current works to predict the drag performance a twist morphing MAV wing design. Based on the drag pattern study, the results exhibits that the morphing wing has a partial similarities in overall drag pattern with the baseline (membrane and rigid wing. However, based CD analysis, it shows that TM wing induced higher CD magnitude (between 25% to 82% higher than to the baseline wing. In fact, TM wing also induced the largest CD increment (about 20% to 27% among the wings. The visualization on vortex structure revealed that TM wing also produce larger tip vortex structure (compared to baseline wings which presume to promote higher induce drag component and subsequently induce its higher CD performance.

  1. Strong CP, flavor, and twisted split fermions

    International Nuclear Information System (INIS)

    Harnik, Roni; Perez, Gilad; Schwartz, Matthew D.; Shirman, Yuri

    2005-01-01

    We present a natural solution to the strong CP problem in the context of split fermions. By assuming CP is spontaneously broken in the bulk, a weak CKM phase is created in the standard model due to a twisting in flavor space of the bulk fermion wavefunctions. But the strong CP phase remains zero, being essentially protected by parity in the bulk and CP on the branes. As always in models of spontaneous CP breaking, radiative corrections to theta bar from the standard model are tiny, but even higher dimension operators are not that dangerous. The twisting phenomenon was recently shown to be generic, and not to interfere with the way that split fermions naturally weaves small numbers into the standard model. It follows that out approach to strong CP is compatible with flavor, and we sketch a comprehensive model. We also look at deconstructed version of this setup which provides a viable 4D model of spontaneous CP breaking which is not in the Nelson-Barr class. (author)

  2. Quadratic Twists of Rigid Calabi–Yau Threefolds Over

    DEFF Research Database (Denmark)

    Gouvêa, Fernando Q.; Kiming, Ian; Yui, Noriko

    2013-01-01

    of weight 4 on some Γ 0(N). We show that quadratic twisting of a threefold corresponds to twisting the attached newform by quadratic characters and illustrate with a number of obvious and not so obvious examples. The question is motivated by the deeper question of which newforms of weight 4 on some Γ 0(N...

  3. Bend-twist coupling potential of wind turbine blades

    DEFF Research Database (Denmark)

    Fedorov, Vladimir; Berggreen, Christian

    2014-01-01

    -twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling...

  4. A twisted generalization of Novikov-Poisson algebras

    OpenAIRE

    Yau, Donald

    2010-01-01

    Hom-Novikov-Poisson algebras, which are twisted generalizations of Novikov-Poisson algebras, are studied. Hom-Novikov-Poisson algebras are shown to be closed under tensor products and several kinds of twistings. Necessary and sufficient conditions are given under which Hom-Novikov-Poisson algebras give rise to Hom-Poisson algebras.

  5. Twisted Acceleration-Enlarged Newton-Hooke Hopf Algebras

    International Nuclear Information System (INIS)

    Daszkiewicz, M.

    2010-01-01

    Ten Abelian twist deformations of acceleration-enlarged Newton-Hooke Hopf algebra are considered. The corresponding quantum space-times are derived as well. It is demonstrated that their contraction limit τ → ∞ leads to the new twisted acceleration-enlarged Galilei spaces. (author)

  6. Enhancement of heat transfer using varying width twisted tape inserts

    African Journals Online (AJOL)

    user

    enhancement of heat transfer with twisted tape inserts as compared to plain ... studies for heat transfer and pressure drop of laminar flow in horizontal tubes ... flow in rectangular and square plain ducts and ducts with twisted-tape inserts .... presence of the insert in the pipe causes resistance to flow and increases turbulence.

  7. Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

    International Nuclear Information System (INIS)

    Nakagawa, Hidenori; Ohuchi, Mikio

    2017-01-01

    We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo. - Highlights: • The principal aim of this research is to contribute to the utilization of the twisted fields for the most effective blood-flow in vivo. • Two newly designed coil systems were used for producing a desirably twisted magnetic field under the measuring domain in the flow channel. • Further, we investigated the magnetohydrodynamic efficiencies of a prototype of a magnetic device, which was converted from use as a commercial alternating magnetic therapy apparatus. • The system was well-constructed with a successful application of a plural exposure coil; therefore, we were able to detect a maximum of induced electromotive force in a fluid of an artificial solution as a substitute for blood. • This new finding demonstrates that the process of blood massotherapy by magnetic stimuli is a therapy for many diseases.

  8. Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Hidenori, E-mail: hnakagawa-tdt@umin.ac.jp; Ohuchi, Mikio

    2017-06-01

    We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo. - Highlights: • The principal aim of this research is to contribute to the utilization of the twisted fields for the most effective blood-flow in vivo. • Two newly designed coil systems were used for producing a desirably twisted magnetic field under the measuring domain in the flow channel. • Further, we investigated the magnetohydrodynamic efficiencies of a prototype of a magnetic device, which was converted from use as a commercial alternating magnetic therapy apparatus. • The system was well-constructed with a successful application of a plural exposure coil; therefore, we were able to detect a maximum of induced electromotive force in a fluid of an artificial solution as a substitute for blood. • This new finding demonstrates that the process of blood massotherapy by magnetic stimuli is a therapy for many diseases.

  9. Electronic and Optical Properties of Twisted Bilayer Graphene

    Science.gov (United States)

    Huang, Shengqiang

    The ability to isolate single atomic layers of van der Waals materials has led to renewed interest in the electronic and optical properties of these materials as they can be fundamentally different at the monolayer limit. Moreover, these 2D crystals can be assembled together layer by layer, with controllable sequence and orientation, to form artificial materials that exhibit new features that are not found in monolayers nor bulk. Twisted bilayer graphene is one such prototype system formed by two monolayer graphene layers placed on top of each other with a twist angle between their lattices, whose electronic band structure depends on the twist angle. This thesis presents the efforts to explore the electronic and optical properties of twisted bilayer graphene by Raman spectroscopy and scanning tunneling microscopy measurements. We first synthesize twisted bilayer graphene with various twist angles via chemical vapor deposition. Using a combination of scanning tunneling microscopy and Raman spectroscopy, the twist angles are determined. The strength of the Raman G peak is sensitive to the electronic band structure of twisted bilayer graphene and therefore we use this peak to monitor changes upon doping. Our results demonstrate the ability to modify the electronic and optical properties of twisted bilayer graphene with doping. We also fabricate twisted bilayer graphene by controllable stacking of two graphene monolayers with a dry transfer technique. For twist angles smaller than one degree, many body interactions play an important role. It requires eight electrons per moire unit cell to fill up each band instead of four electrons in the case of a larger twist angle. For twist angles smaller than 0.4 degree, a network of domain walls separating AB and BA stacking regions forms, which are predicted to host topologically protected helical states. Using scanning tunneling microscopy and spectroscopy, these states are confirmed to appear on the domain walls when inversion

  10. Duality and braiding in twisted quantum field theory

    International Nuclear Information System (INIS)

    Riccardi, Mauro; Szabo, Richard J.

    2008-01-01

    We re-examine various issues surrounding the definition of twisted quantum field theories on flat noncommutative spaces. We propose an interpretation based on nonlocal commutative field redefinitions which clarifies previously observed properties such as the formal equivalence of Green's functions in the noncommutative and commutative theories, causality, and the absence of UV/IR mixing. We use these fields to define the functional integral formulation of twisted quantum field theory. We exploit techniques from braided tensor algebra to argue that the twisted Fock space states of these free fields obey conventional statistics. We support our claims with a detailed analysis of the modifications induced in the presence of background magnetic fields, which induces additional twists by magnetic translation operators and alters the effective noncommutative geometry seen by the twisted quantum fields. When two such field theories are dual to one another, we demonstrate that only our braided physical states are covariant under the duality

  11. Analysis list: Twist1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Twist1 Embryo,Neural + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Tw...ist1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Twist1.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/mm9/target/Twist1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Twist1.Embryo.tsv,http://dbarchive.bioscien...cedbc.jp/kyushu-u/mm9/colo/Twist1.Neural.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Neural.gml ...

  12. 75 FR 14342 - Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary Services by...

    Science.gov (United States)

    2010-03-25

    ...; Order No. 697-D] Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary... affiliates.\\3\\ \\1\\ Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary Services...\\ Market-Based Rates for Wholesale Sales of Electric Energy, Capacity and Ancillary Services by Public...

  13. 77 FR 40413 - Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric...

    Science.gov (United States)

    2012-07-09

    ... Ancillary Services; Accounting and Financial Reporting for New Electric Storage Technologies AGENCY: Federal... Ancillary Services; Accounting and Financial Reporting for New Electric Storage Technologies, 135 FERC ] 61... Commission 18 CFR Parts 35, 37, and 101 Third-Party Provision of Ancillary Services; Accounting and Financial...

  14. Bianisotropic metamaterials based on twisted asymmetric crosses

    International Nuclear Information System (INIS)

    Reyes-Avendaño, J A; Sampedro, M P; Juárez-Ruiz, E; Pérez-Rodríguez, F

    2014-01-01

    The effective bianisotropic response of 3D periodic metal-dielectric structures, composed of crosses with asymmetrically-cut wires, is investigated within a general homogenization theory using the Fourier formalism and the form-factor division approach. It is found that the frequency dependence of the effective permittivity for a system of periodically-repeated layers of metal crosses exhibits two strong resonances, whose separation is due to the cross asymmetry. Besides, bianisotropic metamaterials, having a base of four twisted asymmetric crosses, are proposed. The designed metamaterials possess negative refractive index at frequencies determined by the cross asymmetry, the gap between the arms of adjacent crosses lying on the same plane, and the type of Bravais lattice. (papers)

  15. Band engineering in twisted molybdenum disulfide bilayers

    Science.gov (United States)

    Zhao, Yipeng; Liao, Chengwei; Ouyang, Gang

    2018-05-01

    In order to explore the theoretical relationship between interlayer spacing, interaction and band offset at the atomic level in vertically stacked two-dimensional (2D) van der Waals (vdW) structures, we propose an analytical model to address the evolution of interlayer vdW coupling with random stacking configurations in MoS2 bilayers based on the atomic-bond-relaxation correlation mechanism. We found that interlayer spacing changes substantially with respect to the orientations, and the bandgap increases from 1.53 eV (AB stacking) to 1.68 eV (AA stacking). Our results reveal that the evolution of interlayer vdW coupling originates from the interlayer interaction, leading to interlayer separations and electronic properties changing with stacking configurations. Our predictions constitute a demonstration of twist engineering the band shift in the emergent class of 2D crystals, transition-metal dichalcogenides.

  16. Unusual presentation of twisted ovarian cyst

    Directory of Open Access Journals (Sweden)

    Vineet V Mishra

    2016-01-01

    Full Text Available Ovarian torsion (also termed as adnexal torsion refers to partial or complete rotation of the ovary and a portion of fallopian tube along its supplying vascular pedicle. It occurs commonly in reproductive age group; more on the right side (60% and often presents with acute lower abdominal pain lasting for few hours and up to 24 h, accounting for 2.7% of acute gynecological conditions. It is one of the devastating conditions, hampering blood supply of ovary which may lead to total necrosis of ovarian tissue and complications, if not diagnosed and managed in time. Hence, we present a case on a twisted ovarian cyst in postmenopausal woman with unusual symptomatology leading to delayed diagnosis and loss of an ovary.

  17. Regular non-twisting S-branes

    International Nuclear Information System (INIS)

    Obregon, Octavio; Quevedo, Hernando; Ryan, Michael P.

    2004-01-01

    We construct a family of time and angular dependent, regular S-brane solutions which corresponds to a simple analytical continuation of the Zipoy-Voorhees 4-dimensional vacuum spacetime. The solutions are asymptotically flat and turn out to be free of singularities without requiring a twist in space. They can be considered as the simplest non-singular generalization of the singular S0-brane solution. We analyze the properties of a representative of this family of solutions and show that it resembles to some extent the asymptotic properties of the regular Kerr S-brane. The R-symmetry corresponds, however, to the general lorentzian symmetry. Several generalizations of this regular solution are derived which include a charged S-brane and an additional dilatonic field. (author)

  18. Bioinspired twisted composites based on Bouligand structures

    Science.gov (United States)

    Pinto, F.; Iervolino, O.; Scarselli, G.; Ginzburg, D.; Meo, M.

    2016-04-01

    The coupling between structural support and protection makes biological systems an important source of inspiration for the development of advanced smart composite structures. In particular, some particular material configurations can be implemented into traditional composites in order to improve their impact resistance and the out-of-plane properties, which represents one of the major weakness of commercial carbon fibres reinforced polymers (CFRP) structures. Based on this premise, a three-dimensional twisted arrangement shown in a vast multitude of biological systems (such as the armoured cuticles of Scarabei, the scales of Arapaima Gigas and the smashing club of Odontodactylus Scyllarus) has been replicated to develop an improved structural material characterised by a high level of in-plane isotropy and a higher interfacial strength generated by the smooth stiffness transition between each layer of fibrils. Indeed, due to their intrinsic layered nature, interlaminar stresses are one of the major causes of failure of traditional CFRP and are generated by the mismatch of the elastic properties between plies in a traditional laminate. Since the energy required to open a crack or a delamination between two adjacent plies is due to the difference between their orientations, the gradual angle variation obtained by mimicking the Bouligand Structures could improve energy absorption and the residual properties of carbon laminates when they are subjected to low velocity impact event. Two different bioinspired laminates were manufactured following a double helicoidal approach and a rotational one and were subjected to a complete test campaign including low velocity impact loading and compared to a traditional quasi-isotropic panel. Fractography analysis via X-Ray tomography was used to understand the mechanical behaviour of the different laminates and the residual properties were evaluated via Compression After Impact (CAI) tests. Results confirmed that the biological

  19. Survey of U.S. Ancillary Services Markets

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhi; Levin, Todd; Conzelmann, Guenter

    2016-06-01

    In addition to providing energy to end-consumers, power system operators are also responsible for ensuring system reliability. To this end, power markets maintain an array of ancillary services to ensure that it is always possible to balance the supply and demand for energy in real-time. A subset of these ancillary services are commonly procured through market-based mechanisms: namely, Regulation, Spinning, and Non-spinning Reserves. Regulation Reserves are maintained to respond to supply/demand imbalances over short time frames, typically on the order of several seconds to one minute. Resources that provide Regulation Reserves adjust their generation or load levels in response to automatic generation control (AGC) signals provided by the system operator. Contingency reserves are maintained to provide additional generation capacity in the event that load increases substantially or supply side resources reduce their output or are taken offline. The reserves are typically segmented into two categories, 1) Spinning or Synchronized Reserves that are provided by generation units that are actively generating and have the ability to increase or decrease their output, 2) Non-spinning or Non-synchronized Reserves that are provided by generation resources that are not actively generating, but are able to start up and provide generation within a specified timeframe. Contingency reserves typically have response times on the order of ten to 30 minutes and can also be provided by demand-side resources that are capable of reducing their load. There are seven distinct power markets in the United States, each operated by a Regional Transmission Operator (RTO) or Independent System Operator (ISO) that operates the transmission system in its territory, operates markets for energy and ancillary services, and maintains system reliability. Each power market offers its own set of ancillary services, and precise definitions, requirements, and market mechanisms differ between markets

  20. Estimating Net Primary Productivity Using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, Bhaskar J.

    2002-01-01

    The net primary productivity (C) or the annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of gross photosynthesis (A(sub g)) and respiration (R) per unit ground area. Available field observations show that R is a large and variable fraction of A(sub g), although it is generally recognized that there are considerable difficulties in determining these fluxes, and thus pose challenge in assessing the accuracy. Further uncertainties arise in extrapolating field measurements (which are acquired over a hectare or so area) to regional scale. Here, an approach is presented for determining these fluxes using satellite and ancillary data to be representative of regional scale and allow assessment of interannual variation. A, has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R(sub g) and R(sub m)).The R(sub m) has been determined from nitrogen content of plant tissue per unit ground area, while R(sub g) has been obtained as a fraction of the difference of A(sub g) and R(sub m). Results for five consecutive years (1986-1990) are presented for the Amazon-Tocontins, Mississippi, and Ob River basins.

  1. Commercial Building Loads Providing Ancillary Services in PJM

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, Jason; Kiliccote, Sila; Boch, Jim; Chen, Jonathan; Nawy, Robert

    2014-06-27

    The adoption of low carbon energy technologies such as variable renewable energy and electric vehicles, coupled with the efficacy of energy efficiency to reduce traditional base load has increased the uncertainty inherent in the net load shape. Handling this variability with slower, traditional resources leads to inefficient system dispatch, and in some cases may compromise reliability. Grid operators are looking to future energy technologies, such as automated demand response (DR), to provide capacity-based reliability services as the need for these services increase. While DR resources are expected to have the flexibility characteristics operators are looking for, demonstrations are necessary to build confidence in their capabilities. Additionally, building owners are uncertain of the monetary value and operational burden of providing these services. To address this, the present study demonstrates the ability of demand response resources providing two ancillary services in the PJM territory, synchronous reserve and regulation, using an OpenADR 2.0b signaling architecture. The loads under control include HVAC and lighting at a big box retail store and variable frequency fan loads. The study examines performance characteristics of the resource: the speed of response, communications latencies in the architecture, and accuracy of response. It also examines the frequency and duration of events and the value in the marketplace which can be used to examine if the opportunity is sufficient to entice building owners to participate.

  2. Exploiting ancillary services from distributed generation - perspectives for the Danish power system

    DEFF Research Database (Denmark)

    Nyeng, Preben; Pedersen, Knud Ole Helgesen; Østergaard, Jacob

    2007-01-01

    The share of the electric power production originating from distributed energy resources has rapidly increased during the recent past. However when it comes to ancillary services necessary to ensure the stability and appropriate operation of the power system, the distributed energy resources take...... a very passive role. This paper outlines suggestions on how to activate the potential of ancillary services from distributed energy resources, thereby exploiting their ability to contribute to power system operation. Furthermore, methods for integrating the ancillary service delivery into a deregulated...

  3. Twisted boundary states in c=1 coset conformal field theories

    International Nuclear Information System (INIS)

    Ishikawa, Hiroshi; Yamaguchi, Atsushi

    2003-01-01

    We study the mutual consistency of twisted boundary conditions in the coset conformal field theory G/H. We calculate the overlap of the twisted boundary states of G/H with the untwisted ones, and show that the twisted boundary states are consistently defined in the charge-conjugation modular invariant. The overlap of the twisted boundary states is expressed by the branching functions of a twisted affine Lie algebra. As a check of our argument, we study the diagonal coset theory so(2n) 1 +so(2n) 1 /so(2n) 2 , which is equivalent to the orbifold S 1 /Z 2 at a particular radius. We construct the boundary states twisted by the automorphisms of the unextended Dynkin diagram of so(2n), and show their mutual consistency by identifying their counterpart in the orbifold. For the triality of so(8), the twisted states of the coset theory correspond to neither the Neumann nor the Dirichlet boundary states of the orbifold and yield conformal boundary states that preserve only the Virasoro algebra. (author)

  4. Conical twist fields and null polygonal Wilson loops

    Science.gov (United States)

    Castro-Alvaredo, Olalla A.; Doyon, Benjamin; Fioravanti, Davide

    2018-06-01

    Using an extension of the concept of twist field in QFT to space-time (external) symmetries, we study conical twist fields in two-dimensional integrable QFT. These create conical singularities of arbitrary excess angle. We show that, upon appropriate identification between the excess angle and the number of sheets, they have the same conformal dimension as branch-point twist fields commonly used to represent partition functions on Riemann surfaces, and that both fields have closely related form factors. However, we show that conical twist fields are truly different from branch-point twist fields. They generate different operator product expansions (short distance expansions) and form factor expansions (large distance expansions). In fact, we verify in free field theories, by re-summing form factors, that the conical twist fields operator product expansions are correctly reproduced. We propose that conical twist fields are the correct fields in order to understand null polygonal Wilson loops/gluon scattering amplitudes of planar maximally supersymmetric Yang-Mills theory.

  5. Conformal invariance and pion wave functions of nonleading twist

    International Nuclear Information System (INIS)

    Braun, V.M.; Filyanov, I.E.

    1989-01-01

    The restrictions are studied for the general structure of pion wave functions of twist 3 and twist 4 imposed by the conformal symmetry and the equations of motion. A systematic expansion of wave functions in the conformal spin is built and the first order corrections to asymptotic formulae are calculated by the QCD sum rule method. In particular, we have found a multiplicatively renormalizable contribution into the two-particle wave function of twist 4 which cannot be expanded in a finite set of Gegenbauer polynomials. 19 refs.; 5 figs

  6. Quantum communication through a spin ring with twisted boundary conditions

    International Nuclear Information System (INIS)

    Bose, S.; Jin, B.-Q.; Korepin, V.E.

    2005-01-01

    We investigate quantum communication between the sites of a spin ring with twisted boundary conditions. Such boundary conditions can be achieved by a magnetic flux through the ring. We find that a nonzero twist can improve communication through finite odd-numbered rings and enable high-fidelity multiparty quantum communication through spin rings (working near perfectly for rings of five and seven spins). We show that in certain cases, the twist results in the complete blockage of quantum-information flow to a certain site of the ring. This effect can be exploited to interface and entangle a flux qubit and a spin qubit without embedding the latter in a magnetic field

  7. TWIST1 promotes invasion through mesenchymal change in human glioblastoma

    Directory of Open Access Journals (Sweden)

    Wakimoto Hiroaki

    2010-07-01

    Full Text Available Abstract Background Tumor cell invasion into adjacent normal brain is a mesenchymal feature of GBM and a major factor contributing to their dismal outcomes. Therefore, better understandings of mechanisms that promote mesenchymal change in GBM are of great clinical importance to address invasion. We previously showed that the bHLH transcription factor TWIST1 which orchestrates carcinoma metastasis through an epithelial mesenchymal transition (EMT is upregulated in GBM and promotes invasion of the SF767 GBM cell line in vitro. Results To further define TWIST1 functions in GBM we tested the impact of TWIST1 over-expression on invasion in vivo and its impact on gene expression. We found that TWIST1 significantly increased SNB19 and T98G cell line invasion in orthotopic xenotransplants and increased expression of genes in functional categories associated with adhesion, extracellular matrix proteins, cell motility and locomotion, cell migration and actin cytoskeleton organization. Consistent with this TWIST1 reduced cell aggregation, promoted actin cytoskeletal re-organization and enhanced migration and adhesion to fibronectin substrates. Individual genes upregulated by TWIST1 known to promote EMT and/or GBM invasion included SNAI2, MMP2, HGF, FAP and FN1. Distinct from carcinoma EMT, TWIST1 did not generate an E- to N-cadherin "switch" in GBM cell lines. The clinical relevance of putative TWIST target genes SNAI2 and fibroblast activation protein alpha (FAP identified in vitro was confirmed by their highly correlated expression with TWIST1 in 39 human tumors. The potential therapeutic importance of inhibiting TWIST1 was also shown through a decrease in cell invasion in vitro and growth of GBM stem cells. Conclusions Together these studies demonstrated that TWIST1 enhances GBM invasion in concert with mesenchymal change not involving the canonical cadherin switch of carcinoma EMT. Given the recent recognition that mesenchymal change in GBMs is

  8. ENTERPRISE RESTRUCTURING AIM AND TYPES

    Directory of Open Access Journals (Sweden)

    S. P. Baranenko

    2011-01-01

    Full Text Available Enterprise restructuring is aimed at adapting it to market conditions and improving its competitiveness through selection of most effective model of using material, technical, technological, organizational, commercial, economical, financial, tax-related and other resources with due account of the demand. Restructuring classification signs and types as well as restructuring aims specific for industrial enterprises are provided for.

  9. EX1504L2 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. EX1504L2 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  11. EX1605L3 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  12. Technical and economic aspects of ancillary services markets in the electric power industry: an international comparison

    International Nuclear Information System (INIS)

    Raineri, R.; Rios, S.; Schiele, D.

    2006-01-01

    We present a comparative analysis of technical and economic aspects of ancillary services on the markets of England and Wales, Nordic Countries, California, Argentina, Australia and Spain, comparing the services of voltage control, frequency regulation and system restoration. All the analyzed markets rely on the existence of an administrator of ancillary services, function that leads to the figure of the system operator. Among the services analyzed, the mandatory nature of voltage control and primary frequency regulation stands out, being both the ancillary services with the higher market price and the shortest period of time requirements. In general, the recognized costs of the services correspond to investments operation, maintenance, and opportunity costs. In the provision of these ancillary services, there are no clear preferences for a particular resource allocation mechanism, where mandatory provision, auctions, competitive offers and different time length bilateral contracts are combined

  13. EX1504L4 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  14. EX1504L4 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  15. EX1504L4 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  16. Ocean Surface Topography Mission (OSTM) /Jason-2: Ancillary Files (NODC Accession 0044982)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the data descriptions for the OSTM/Jason-2 Ancillary data files, which is served through the NOAA/NESDIS Comprehensive Large Array-data...

  17. EX1504L3 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  18. EX1605L3 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  19. EX1504L2 Dive17 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  20. EX1504L2 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  1. EX1504L4 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  2. EX1504L2 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  3. EX1605L3 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  4. EX1504L3 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  5. EX1605L3 Dive19 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  6. EX1606 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  7. EX1504L4 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. EX1504L3 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  9. EX1504L4 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  10. EX1504L2 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  11. EX1504L2 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  12. EX1606 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  13. EX1504L2 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  14. EX1504L4 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  15. EX1504L2 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  16. EX1504L2 Dive18 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  17. EX1504L3 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  18. EX1504L2 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  19. EX1504L4 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  20. EX1605L3 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  1. EX1504L2 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  2. EX1504L4 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  3. EX1606 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  4. EX1504L2 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  5. EX1504L4 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  6. EX1504L2 Dive15 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  7. EX1504L4 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. Trace Metal and Ancillary Data in Puget Sound, 1980 - 1986 (NODC Accession 9100153)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In first of three data reports on the trace metal and ancillary data in Puget Sound and its watershed (Paulson et al., 1991a), all water column, sediment, and...

  9. EX1504L2 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. EX1606 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  11. EX1605L3 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  12. EX1605L3 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  13. EX1606 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1606: CAPSTONE Wake Island...

  14. EX1504L4 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  15. EX1504L2 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  16. EX1605L3 Dive20 Ancillary Data Collection including reports, kmls, spreadsheets, and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1605L3: CAPSTONE CNMI &...

  17. EX1504L4 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  18. EX1504L3 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L3: CAPSTONE Leg III:...

  19. Renormalization of quark propagator, vertex functions, and twist-2 operators from twisted-mass lattice QCD at Nf=4

    Science.gov (United States)

    Blossier, Benoît.; Brinet, Mariane; Guichon, Pierre; Morénas, Vincent; Pène, Olivier; Rodríguez-Quintero, Jose; Zafeiropoulos, Savvas

    2015-06-01

    We present a precise nonperturbative determination of the renormalization constants in the mass independent RI'-MOM scheme. The lattice implementation uses the Iwasaki gauge action and four degenerate dynamical twisted-mass fermions. The gauge configurations are provided by the ETM Collaboration. Renormalization constants for scalar, pseudoscalar, vector and axial operators, as well as the quark propagator renormalization, are computed at three different values of the lattice spacing, two volumes and several twisted-mass parameters. The method we developed allows for a precise cross-check of the running, thanks to the particular proper treatment of hypercubic artifacts. Results for the twist-2 operator O44 are also presented.

  20. The Nordic approach to market-based provision of ancillary services

    International Nuclear Information System (INIS)

    Kristiansen, Tarjei

    2007-01-01

    This paper presents an overview of the markets for ancillary services, which are regulated and traded differently within and across borders in the Nordic countries. We describe the services provided and their characteristics in terms of definition, participation, contracting approach and duration, selection of offers, and dispatch criteria. Further, we assess the costs, specify the payments, and discuss cost allocation, and we conclude with a policy discussion of ancillary services in the Nordic countries. (author)

  1. Enhancement of heat transfer using varying width twisted tape inserts

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology ... experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of varying width twisted tape inserts with air as the working fluid.

  2. Periodic solutions of asymptotically linear Hamiltonian systems without twist conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Rong [Coll. of Mathematics and Physics, Nanjing Univ. of Information Science and Tech., Nanjing (China); Dept. of Mathematics, Southeast Univ., Nanjing (China); Zhang Dongfeng [Dept. of Mathematics, Southeast Univ., Nanjing (China)

    2010-05-15

    In dynamical system theory, especially in many fields of applications from mechanics, Hamiltonian systems play an important role, since many related equations in mechanics can be written in an Hamiltonian form. In this paper, we study the existence of periodic solutions for a class of Hamiltonian systems. By applying the Galerkin approximation method together with a result of critical point theory, we establish the existence of periodic solutions of asymptotically linear Hamiltonian systems without twist conditions. Twist conditions play crucial roles in the study of periodic solutions for asymptotically linear Hamiltonian systems. The lack of twist conditions brings some difficulty to the study. To the authors' knowledge, very little is known about the case, where twist conditions do not hold. (orig.)

  3. The geometric Langlands twist in five and six dimensions

    International Nuclear Information System (INIS)

    Bak, Dongsu; Gustavsson, Andreas

    2015-01-01

    Abelian 6d (2,0) theory has SO(5) R symmetry. We twist this theory by identifying the R symmetry group with the SO(5) subgroup of the SO(1,5) Lorentz group. This twisted theory can be put on any five-manifold M, times R, while preserving one scalar supercharge. We subsequently assume the existence of one unit normalized Killing vector field on M, and we find a corresponding SO(4) twist that preserves two supercharges and is a generalization of the geometric Langlands twist of 4d SYM. We generalize the story to non-Abelian gauge group for the corresponding 5d SYM theories on M. We derive a vanishing theorem for BPS contact instantons by identifying the 6d potential energy and its BPS bound, in the 5d theory. To this end we need to perform a Wick rotation that complexifies the gauge field.

  4. Static-light meson masses from twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Jansen, Karl; Michael, Chris; Shindler, Andrea; Wagner, Marc

    2008-08-01

    We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeV PS S mesons. (orig.)

  5. Higher-Twist Dynamics in Large Transverse Momentum Hadron Production

    International Nuclear Information System (INIS)

    Francois, Alero

    2009-01-01

    A scaling law analysis of the world data on inclusive large-p # perpendicular# hadron production in hadronic collisions is carried out. A significant deviation from leading-twist perturbative QCD predictions at next-to-leading order is reported. The observed discrepancy is largest at high values of x # perpendicular# = 2p # perpendicular#/√s. In contrast, the production of prompt photons and jets exhibits the scaling behavior which is close to the conformal limit, in agreement with the leading-twist expectation. These results bring evidence for a non-negligible contribution of higher-twist processes in large-p # perpendicular# hadron production in hadronic collisions, where the hadron is produced directly in the hard subprocess rather than by gluon or quark jet fragmentation. Predictions for scaling exponents at RHIC and LHC are given, and it is suggested to trigger the isolated large-p # perpendicular# hadron production to enhance higher-twist processes.

  6. Flux Density through Guides with Microstructured Twisted Clad DB Medium

    Directory of Open Access Journals (Sweden)

    M. A. Baqir

    2014-01-01

    Full Text Available The paper deals with the study of flux density through a newly proposed twisted clad guide containing DB medium. The inner core and the outer clad sections are usual dielectrics, and the introduced twisted windings at the core-clad interface are treated under DB boundary conditions. The pitch angle of twist is supposed to greatly contribute towards the control over the dispersion characteristics of the guide. The eigenvalue equation for the guiding structure is deduced, and the analytical investigations are made to explore the propagation patterns of flux densities corresponding to the sustained low-order hybrid modes under the situation of varying pitch angles. The emphasis has been put on the effects due to the DB twisted pitch on the propagation of energy flux density through the guide.

  7. Õnnetu saatusega Oliver Twist Polanski meelevallas / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2005-01-01

    Mängufilm Charles Dickensi romaani järgi "Oliver Twist" : stsenarist Ronald Harwood : režissöör Roman Polanski : nimiosas Barney Clark, Fagin - Ben Kingsley : Suurbritannia - Tšehhi - Prantsusmaa - Itaalia 2005

  8. Ancillary benefits of climate policy in a small open economy: The case of Sweden

    International Nuclear Information System (INIS)

    Krook Riekkola, Anna; Ahlgren, Erik O.; Soederholm, Patrik

    2011-01-01

    It is increasingly recognised that GHG reduction policies can have important ancillary benefits in the form of positive local and regional environmental impacts. The purpose of this paper is to estimate the domestic ancillary pollution benefits of climate policy in Sweden, and investigate how these are affected by different climate policy designs. The latter differ primarily in terms of how the country chooses to meet a specific target and where the necessary emission reductions take place. The analysis relies on simulations within the energy system optimisation model TIMES-Sweden, and focuses on four non-GHG pollutants: Nitrogen Oxides (NO X ), Non Methane Volatile Organic Compounds (NMVOC), inhalable particles (PM 2.5 ), and Sulphur dioxide (SO 2 ). The simulations permit detailed assessments of the respective technology and fuel choices that underlie any net changes in the estimated ancillary effects. The results indicate that the ancillary benefits constitute a far from insignificant share of total system costs, and this share appears to be highest in the scenarios that entail the largest emission reductions domestically. This result reflects the fact that carbon dioxide emission reductions abroad also implies a lost opportunity of achieving substantial domestic welfare gain from the reductions of regional and local environmental pollutants. - Highlights: → We estimate the domestic ancillary pollution benefits of climate policy in Sweden. → These constitute a sizeable share of total system costs. → The ancillary benefits are highest in the policy scenarios that entail the largest emission reductions domestically.

  9. Study of twist boundaries in aluminium. Structure and intergranular diffusion

    International Nuclear Information System (INIS)

    Lemuet, Daniel

    1981-01-01

    This research thesis addresses the study of grain boundaries in oriented crystals, and more particularly the systematic calculation of intergranular structures and energies of twist boundaries of <001> axis in aluminium, the determination of intergranular diffusion coefficients of zinc in a set of twist bi-crystals of same axis encompassing a whole range of disorientations, and the search for a correlation between these experimental results and calculated structures

  10. 'Twisted' strings and higher level Kac-Moody representations

    International Nuclear Information System (INIS)

    Horvath, Z.; Palla, L.

    1989-01-01

    Using an orbifold-like construction the twisted sector of a closed string moving on GxG (with G simply laced) is determined. A level-two G current operating there is constructed explicitly. The decomposition of the twisted sector into products between appropriate conformal and level-two G representations is given if 2 rank G-2 dim G/(2+g)<1. (orig.)

  11. The diverse aims of science.

    Science.gov (United States)

    Potochnik, Angela

    2015-10-01

    There is increasing attention to the centrality of idealization in science. One common view is that models and other idealized representations are important to science, but that they fall short in one or more ways. On this view, there must be an intermediary step between idealized representation and the traditional aims of science, including truth, explanation, and prediction. Here I develop an alternative interpretation of the relationship between idealized representation and the aims of science. I suggest that continuing, widespread idealization calls into question the idea that science aims for truth. If instead science aims to produce understanding, this would enable idealizations to directly contribute to science's epistemic success. I also use the fact of widespread idealization to motivate the idea that science's wide variety aims, epistemic and non-epistemic, are best served by different kinds of scientific products. Finally, I show how these diverse aims—most rather distant from truth—result in the expanded influence of social values on science. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. New look at the dynamics of twisted accretion disks

    International Nuclear Information System (INIS)

    Hatchett, S.P.; Begelman, M.C.; Sarazin, C.L.

    1981-01-01

    We reexamine the dynamic response of a thin, accretion disk to twisting torques, guided by the earlier analyses by Bardeen and Petterson. We make several corrections to this earlier work, and present a new version of the twist equations consistent with their physical assumptions. By describing the distortion of the disk in terms Cartesian direction cosines rather than the Euler angles used by the earlier authors, we are able to transform the twist equations from a pair of coupled, nonlinear, partial differential equations to a single, linear, complex one. We write down formulae for the external twisting torques likley to be encountered in astrophysic, and we show that even with these driving torques our twist equation remains linear. We find exact, analytic solutions for steady state structure of a disk subject to Lense-Thirring torques by a nonaligned central Kerr black hole and also for the time-dependent problem of the structure of a slaved disk with its oscillating boundary conditions. Finally, we discuss the stability of disks against twisting modes and show that undriven disks and disks subject to time-independent driving torques are stable

  13. Observations on discretization errors in twisted-mass lattice QCD

    International Nuclear Information System (INIS)

    Sharpe, Stephen R.

    2005-01-01

    I make a number of observations concerning discretization errors in twisted-mass lattice QCD that can be deduced by applying chiral perturbation theory including lattice artifacts. (1) The line along which the partially conserved axial current quark mass vanishes in the untwisted-mass-twisted-mass plane makes an angle to the twisted-mass axis which is a direct measure of O(a) terms in the chiral Lagrangian, and is found numerically to be large; (2) Numerical results for pionic quantities in the mass plane show the qualitative properties predicted by chiral perturbation theory, in particular, an asymmetry in slopes between positive and negative untwisted quark masses; (3) By extending the description of the 'Aoki regime' (where m q ∼a 2 Λ QCD 3 ) to next-to-leading order in chiral perturbation theory I show how the phase-transition lines and lines of maximal twist (using different definitions) extend into this region, and give predictions for the functional form of pionic quantities; (4) I argue that the recent claim that lattice artifacts at maximal twist have apparent infrared singularities in the chiral limit results from expanding about the incorrect vacuum state. Shifting to the correct vacuum (as can be done using chiral perturbation theory) the apparent singularities are summed into nonsingular, and furthermore predicted, forms. I further argue that there is no breakdown in the Symanzik expansion in powers of lattice spacing, and no barrier to simulating at maximal twist in the Aoki regime

  14. Twisting short dsDNA with applied tension

    Science.gov (United States)

    Zoli, Marco

    2018-02-01

    The twisting deformation of mechanically stretched DNA molecules is studied by a coarse grained Hamiltonian model incorporating the fundamental interactions that stabilize the double helix and accounting for the radial and angular base pair fluctuations. The latter are all the more important at short length scales in which DNA fragments maintain an intrinsic flexibility. The presented computational method simulates a broad ensemble of possible molecule conformations characterized by a specific average twist and determines the energetically most convenient helical twist by free energy minimization. As this is done for any external load, the method yields the characteristic twist-stretch profile of the molecule and also computes the changes in the macroscopic helix parameters i.e. average diameter and rise distance. It is predicted that short molecules under stretching should first over-twist and then untwist by increasing the external load. Moreover, applying a constant load and simulating a torsional strain which over-twists the helix, it is found that the average helix diameter shrinks while the molecule elongates, in agreement with the experimental trend observed in kilo-base long sequences. The quantitative relation between percent relative elongation and superhelical density at fixed load is derived. The proposed theoretical model and computational method offer a general approach to characterize specific DNA fragments and predict their macroscopic elastic response as a function of the effective potential parameters of the mesoscopic Hamiltonian.

  15. Scanning tunneling microscopy and spectroscopy of twisted trilayer graphene

    Science.gov (United States)

    Zuo, Wei-Jie; Qiao, Jia-Bin; Ma, Dong-Lin; Yin, Long-Jing; Sun, Gan; Zhang, Jun-Yang; Guan, Li-Yang; He, Lin

    2018-01-01

    Twist, as a simple and unique degree of freedom, could lead to enormous novel quantum phenomena in bilayer graphene. A small rotation angle introduces low-energy van Hove singularities (VHSs) approaching the Fermi level, which result in unusual correlated states in the bilayer graphene. It is reasonable to expect that the twist could also affect the electronic properties of few-layer graphene dramatically. However, such an issue has remained experimentally elusive. Here, by using scanning tunneling microscopy/spectroscopy (STM/STS), we systematically studied a twisted trilayer graphene (TTG) with two different small twist angles between adjacent layers. Two sets of VHSs, originating from the two twist angles, were observed in the TTG, indicating that the TTG could be simply regarded as a combination of two different twisted bilayers of graphene. By using high-resolution STS, we observed a split of the VHSs and directly imaged the spatial symmetry breaking of electronic states around the VHSs. These results suggest that electron-electron interactions play an important role in affecting the electronic properties of graphene systems with low-energy VHSs.

  16. Flux compactifications, twisted tori and doubled geometry

    International Nuclear Information System (INIS)

    Reid-Edwards, R.A.

    2009-01-01

    In [1] an O(D,D)-covariant sigma model describing the embedding of a closed world-sheet into the 2D-dimensional twisted torus X was proposed. Such sigma models provide a universal description of string theory with target spaces related by the action of T-duality. In this article a six-dimensional toy example is studied in detail. Different polarisations of the six-dimensional target space give different three-dimensional string backgrounds including a nilmanifold with H-flux, a T-fold with R-flux and a new class of T-folds. Global issues and connections with the doubled torus formalism are discussed. Finally, the sigma model introduced in [1], describing the embedding of a world-sheet into X, is generalised to one describing a target space which is a bundle of X over a base M d , allowing for a more complete description of the associated gauged supergravity from the world-sheet perspective to be given.

  17. Twisted conformal field theories and Morita equivalence

    Energy Technology Data Exchange (ETDEWEB)

    Marotta, Vincenzo [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' and INFN, Sezione di Napoli, Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy); Naddeo, Adele [CNISM, Unita di Ricerca di Salerno and Dipartimento di Fisica ' E.R. Caianiello' , Universita degli Studi di Salerno, Via Salvador Allende, 84081 Baronissi (Italy); Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , Compl. universitario M. Sant' Angelo, Via Cinthia, 80126 Napoli (Italy)], E-mail: adelenaddeo@yahoo.it

    2009-04-01

    The Morita equivalence for field theories on noncommutative two-tori is analysed in detail for rational values of the noncommutativity parameter {theta} (in appropriate units): an isomorphism is established between an Abelian noncommutative field theory (NCFT) and a non-Abelian theory of twisted fields on ordinary space. We focus on a particular conformal field theory (CFT), the one obtained by means of the m-reduction procedure [V. Marotta, J. Phys. A 26 (1993) 3481; V. Marotta, Mod. Phys. Lett. A 13 (1998) 853; V. Marotta, Nucl. Phys. B 527 (1998) 717; V. Marotta, A. Sciarrino, Mod. Phys. Lett. A 13 (1998) 2863], and show that it is the Morita equivalent of a NCFT. Finally, the whole m-reduction procedure is shown to be the image in the ordinary space of the Morita duality. An application to the physics of a quantum Hall fluid at Jain fillings {nu}=m/(2pm+1) is explicitly discussed in order to further elucidate such a correspondence and to clarify its role in the physics of strongly correlated systems. A new picture emerges, which is very different from the existing relationships between noncommutativity and many body systems [A.P. Polychronakos, arXiv: 0706.1095].

  18. How the embryonic chick brain twists.

    Science.gov (United States)

    Chen, Zi; Guo, Qiaohang; Dai, Eric; Forsch, Nickolas; Taber, Larry A

    2016-11-01

    During early development, the tubular embryonic chick brain undergoes a combination of progressive ventral bending and rightward torsion, one of the earliest organ-level left-right asymmetry events in development. Existing evidence suggests that bending is caused by differential growth, but the mechanism for the predominantly rightward torsion of the embryonic brain tube remains poorly understood. Here, we show through a combination of in vitro experiments, a physical model of the embryonic morphology and mechanics analysis that the vitelline membrane (VM) exerts an external load on the brain that drives torsion. Our theoretical analysis showed that the force is of the order of 10 micronewtons. We also designed an experiment to use fluid surface tension to replace the mechanical role of the VM, and the estimated magnitude of the force owing to surface tension was shown to be consistent with the above theoretical analysis. We further discovered that the asymmetry of the looping heart determines the chirality of the twisted brain via physical mechanisms, demonstrating the mechanical transfer of left-right asymmetry between organs. Our experiments also implied that brain flexure is a necessary condition for torsion. Our work clarifies the mechanical origin of torsion and the development of left-right asymmetry in the early embryonic brain. © 2016 The Author(s).

  19. Complex Toda theories and twisted reality conditions

    International Nuclear Information System (INIS)

    Evans, J.M.

    1993-01-01

    The Toda equations (based on a finite-dimensional or affine Lie algebra of superalgebra) are discussed as integrable non-linear differential equations for a set of complex scalar fields. We show that such complex Toda fields can either be restricted to take real values in the standard way or else they can be subjected to a 'twisted' reality condition associated to any Z 2 symmetry of the Cartan matrix or Dynkin diagram of the underlying algebra. Different reality conditions give rise to different lagrangian field theories. In the conformal case, however, these theories have the same central charge, while in the affine case they have the same mass spectrum. The construction of N=2 superconformal theories based on the superalgebras A(n, n-1) is clarified, and a new class of conformal field theories with positive kinetic energy based on the superalgebras C(n) is presented. The ideas developed are also relevant to understanding solition solutions in affine Toda theories with imaginary coupling constant. (orig.)

  20. Aim For a Healthy Weight

    Science.gov (United States)

    ... out of your control, you can make positive lifestyle changes to lose weight and to maintain a healthy weight. These include a healthy eating plan and being more physically active. Take the Challenge When it comes to aiming for a healthy ...

  1. Incidence of Deformation and Fracture of Twisted File Adaptive Instruments after Repeated Clinical Use

    Directory of Open Access Journals (Sweden)

    Gianluca Gambarini

    2017-01-01

    Full Text Available Objectives: The aim of the present study was to investigate the incidence of deformation and fracture of twisted file adaptive nickel-titanium instruments after repeated clinical use and to identify and check whether the three instruments within the small/medium sequence showed similar or different visible signs of metal fatigue. Material and Methods: One-hundred twenty twisted file adaptive (TFA packs were collected after clinically used to prepare three molars and were inspected for deformations and fracture. Results: The overall incidence of deformation was 22.2%, which was not evenly distributed within the instruments: 15% for small/medium (SM1 (n = 18, 38.33% for SM2 (n = 46 and 13.33% for the SM3 instruments (n = 16. The defect rate of SM2 instruments was statistically higher than the other two (P < 0.001. The fracture rate was 0.83% (n = 3, being two SM2 instruments and one SM3. Conclusions: It was observed a very low defect rate after clinical use of twisted file adaptive rotary instruments. The untwisting of flutes was significantly more frequent than fracture, which might act as prevention for breakage. The results highlight the fact that clinicians should be aware that instruments within a sequence might be differently subjected to intracanal stress.

  2. Composite beam analysis linear analysis of naturally curved and twisted anisotropic beams

    Science.gov (United States)

    Borri, Marco; Ghiringhelli, Gian L.; Merlini, Teodoro

    1992-05-01

    The aim of this report is to present a consistent theory for the deformation of a naturally curved and twisted anisotropic beam. The proposed formulation naturally extends the classical Saint-Venant approach to the case of curved and twisted anisotropic beams. The mathematical model developed under the assumption of span-wise uniform cross-section, curvature and twist, can take into account any kind of elastic coupling due to the material properties and the curved geometry. The consistency of the presented math-model and its generality about the cross-sectional shape, make it a useful tool even in a preliminary design optimization context such as the aeroelastic tailoring of helicopter rotor blades. The advantage of the present procedure is that it only requires a two-dimensional discretization; thus, very detailed analyses can be performed and interlaminar stresses between laminae can be evaluated. Such analyses would be extremely time consuming if performed with standard finite element codes: that prevents their recursive use as for example when optimizing a beam design. Moreover, as a byproduct of the proposed formulation, one obtains the constitutive law of the cross-section in terms of stress resultant and moment and their conjugate strain measures. This constitutive law takes into account any kind of elastic couplings, e.g., torsion-tension, tension-shear, bending-shear, and constitutes a fundamental input in aeroelastic analyses of helicopter blades. Four simple examples are given in order to show the principal features of the method.

  3. 'Twisted tape sign': Its significance in recurrent sigmoid volvulus

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, K. [Tameside and Glossop Acute Services NHS Trust, Fountain Street, Ashton-under-Lyne OL6 9RW (United Kingdom)]. E-mail: karthikgopal73@yahoo.co.uk; Lim, Y. [Tameside and Glossop Acute Services NHS Trust, Fountain Street, Ashton-under-Lyne OL6 9RW (United Kingdom); Banerjee, B. [Tameside and Glossop Acute Services NHS Trust, Fountain Street, Ashton-under-Lyne OL6 9RW (United Kingdom)

    2005-11-01

    Aim: Sigmoid volvulus is a common cause of intestinal obstruction in the elderly. Mild attacks of sigmoid volvulus may be more difficult to diagnose due to the lack of severity of symptoms which may resolve spontaneously only to recur after an interval. This study was a review of patients to assess the incidence of the 'twisted tape sign' and to evaluate the significance of its presence in cases of recurrent sigmoid volvulus. Methods and materials: A retrospective study over eight years revealed six cases of surgically confirmed recurrent sigmoid volvulus. Case records and barium enemas of all patients were reviewed. Results: Six patients were identified, including four men and two women, with a median age of 56 years. Diagnostic difficulties were encountered in four (67%) patients with a delay ranging between 10 and 37 months with a mean 17.3 months. Twisted tape sign was confirmed on all barium examinations retrospectively. Conclusion: Recognition of twisted tape sign on barium enema examination along with an appropriate clinical history would suggest a diagnosis of recurrent sigmoid volvulus.

  4. Nucleon structure by Lattice QCD computations with twisted mass fermions

    International Nuclear Information System (INIS)

    Harraud, P.A.

    2010-11-01

    Understanding the structure of the nucleon from quantum chromodynamics (QCD) is one of the greatest challenges of hadronic physics. Only lattice QCD allows to determine numerically the values of the observables from ab-initio principles. This thesis aims to study the nucleon form factors and the first moments of partons distribution functions by using a discretized action with twisted mass fermions. As main advantage, the discretization effects are suppressed at first order in the lattice spacing. In addition, the set of simulations allows a good control of the systematical errors. After reviewing the computation techniques, the results obtained for a wide range of parameters are presented, with lattice spacings varying from 0.0056 fm to 0.089 fm, spatial volumes from 2.1 up to 2.7 fm and several pion masses in the range of 260-470 MeV. The vector renormalization constant was determined in the nucleon sector with improved precision. Concerning the electric charge radius, we found a finite volume effect that provides a key towards an explanation of the chiral dependence of the physical point. The results for the magnetic moment, the axial charge, the magnetic and axial charge radii, the momentum and spin fractions carried by the quarks show no dependence on the lattice spacing nor volume. In our range of pion masses, their values show a deviation from the experimental values. Their chiral behaviour do not exhibit the curvature predicted by the chiral perturbation theory which could explain the apparent discrepancy. (author)

  5. Mid-term fire danger index based on satellite imagery and ancillary geographic data

    Science.gov (United States)

    Stefanidou, A.; Dragozi, E.; Tompoulidou, M.; Stepanidou, L.; Grigoriadis, D.; Katagis, T.; Stavrakoudis, D.; Gitas, I.

    2017-09-01

    Fire danger forecast constitutes one of the most important components of integrated fire management since it provides crucial information for efficient pre-fire planning, alertness and timely response to a possible fire event. The aim of this work is to develop an index that has the capability of predicting accurately fire danger on a mid-term basis. The methodology that is currently under development is based on an innovative approach that employs dry fuel spatial connectivity as well as biophysical and topological variables for the reliable prediction of fire danger. More specifically, the estimation of the dry fuel connectivity is based on a previously proposed automated procedure implemented in R software that uses Moderate Resolution Imaging Spectrometer (MODIS) time series data. Dry fuel connectivity estimates are then combined with other ancillary data such as fuel type and proximity to roads in order to result in the generation of the proposed mid-term fire danger index. The innovation of the proposed index—which will be evaluated by comparison to historical fire data—lies in the fact that its calculation is almost solely affected by the availability of satellite data. Finally, it should be noted that the index is developed within the framework of the National Observatory of Forest Fires (NOFFi) project.

  6. Prosomeric map of the lamprey forebrain based on calretinin immunocytochemistry, Nissl stain, and ancillary markers.

    Science.gov (United States)

    Pombal, M A; Puelles, L

    1999-11-22

    The structural organization of the lamprey extratelencephalic forebrain is re-examined from the perspective of the prosomeric segmental paradigm. The question asked was whether the prosomeric forebrain model used for gnathostomes is of material advantage for interpreting subdivisions in the lamprey forebrain. To this aim, the main longitudinal and transverse landmarks recognized by the prosomeric model in other vertebrates were identified in Nissl-stained lamprey material. Lines of cytoarchitectural discontinuity and contours of migrated neuronal groups were mapped in a two-dimensional sagittal representation and were also classified according to their radial position. Immunocytochemical mapping of calretinin expression in adjacent sections served to define particular structural units better, in particular, the dorsal thalamus. These data were complemented by numerous other chemoarchitectonic observations obtained with ancillary markers, which identified additional specific formations, subdivisions, or boundaries. Emphasis was placed on studying whether such chemically defined neuronal groups showed boundaries aligned with the postulated inter- or intraprosomeric boundaries. The course of diverse axonal tracts was studied also with regard to their prosomeric topography. This analysis showed that the full prosomeric model applies straightforwardly to the lamprey forebrain. This finding implies that a common segmental and longitudinal organization of the neural tube may be primitive for all vertebrates. Interesting novel aspects appear in the interpretation of the lamprey pretectum, the dorsal and ventral thalami, and the hypothalamus. The topologic continuity of the prosomeric forebrain regions with evaginated or non-evaginated portions of the telencephalon was also examined. Copyright 1999 Wiley-Liss, Inc.

  7. Current perspectives on the use of ancillary materials for the manufacture of cellular therapies.

    Science.gov (United States)

    Solomon, Jennifer; Csontos, Lynn; Clarke, Dominic; Bonyhadi, Mark; Zylberberg, Claudia; McNiece, Ian; Kurtzberg, Joanne; Bell, Rosemarie; Deans, Robert

    2016-01-01

    Continued growth in the cell therapy industry and commercialization of cell therapies that successfully advance through clinical trials has led to increased awareness around the need for specialized and complex materials utilized in their manufacture. Ancillary materials (AMs) are components or reagents used during the manufacture of cell therapy products but are not intended to be part of the final products. Commonly, there are limitations in the availability of clinical-grade reagents used as AMs. Furthermore, AMs may affect the efficacy of the cell product and subsequent safety of the cell therapy for the patient. As such, AMs must be carefully selected and appropriately qualified during the cell therapy development process. However, the ongoing evolution of cell therapy research, limited number of clinical trials and registered cell therapy products results in the current absence of specific regulations governing the composition, compliance, and qualification of AMs often leads to confusion by suppliers and users in this field. Here we provide an overview and interpretation of the existing global framework surrounding AM use and investigate some common misunderstandings within the industry, with the aim of facilitating the appropriate selection and qualification of AMs. The key message we wish to emphasize is that in order to most effectively mitigate risk around cell therapy development and patient safety, users must work with their suppliers and regulators to qualify each AM to assess source, purity, identity, safety, and suitability in a given application. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  8. Estimating Next Primary Productivity using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, B. J.

    The net primary productivity (C) or annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of the rate of gross photosynthesis (Ag) and autotrophic respiration (R) per unit ground area. Although available observations show that R is a large and variable fraction of Ag, viz., 0.3 to 0.7, it is generally recognized that much uncertainties exist in this fraction due to difficulties associated with the needed measurements. Additional uncertainties arise when these measurements are extrapolated to regional or global land surface using empirical equations, for example, using regression equations relating C to mean annual precipitation and air temperature. Here, a process- based approach has been taken to calculate Ag and R using satellite and ancillary data. Ag has been expressed as a product of radiation use efficiency, magnitude of intercepted photosynthetically active radiation (PAR), and normalized by stresses due to soil water shortage and air temperature away from the optimum range. A biophysical model has been used to determine the radiation use efficiency from the maximum rate of carbon assimilation by a leaf, foliage temperature, and the fraction of diffuse PAR incident on a canopy. All meteorological data (PAR, air temperature, precipitation, etc.) needed for the calculation are derived from satellite observations, while a land use, land cover data (based on satellite and ground measurements) have been used to assess the maximum rate of carbon assimilation by a leaf of varied cover type based on field measurements. R has been calculated as the sum of maintenance and growth components. The maintenance respiration of foliage and live fine roots at a standard temperature of different land cover has been determined from their nitrogen content using field and satellite measurements, while that of living fraction of woody stem (viz., sapwood) from the seasonal maximum leaf area index as determined from satellite

  9. Aims, assessments and workplace needs

    Science.gov (United States)

    Black, Paul

    1997-03-01

    This paper attempts to consider the aims that undergraduate physics degree courses actually reflect and serve in the light of the employment patterns of graduates and of the expressed needs of employers. Calling on evidence mainly from the UK, it reviews analyses of what degree examinations actually test, and goes on to quote criticisms of their courses and radical proposals to change them adopted by the senior physics professors in the UK. The discussion is then broadened by discussion of evidence, about the employment of graduates and about the priorities that some industrialists now give in the qualities that they look for when recruiting new graduates. The evidence leads to a view that radical changes are needed, both in courses and examinations, and that there is a need for university departments to work more closely with employers in re-formulating the aims and priorities in their teaching.

  10. Studies on the separation between higher-twist and minimum-twist in the photoproduction experiment WA69 at the CERN-OMEGA spectrometer

    International Nuclear Information System (INIS)

    Kingler, J.

    1990-01-01

    A Lund type Monte Carlo program (LUCIFER) is used to describe in perturbative QCD the pointlike component of the photon interacting on a hydrogen target. Kinematical and topological variables are developed to enhance higher twist events on the lowest order minimum twist background. The emphasis is laid on π ± , K ± higher twist mesons. (orig.)

  11. Phosphorylation of basic helix-loop-helix transcription factor Twist in development and disease.

    Science.gov (United States)

    Xue, Gongda; Hemmings, Brian A

    2012-02-01

    The transcription factor Twist plays vital roles during embryonic development through regulating/controlling cell migration. However, postnatally, in normal physiological settings, Twist is either not expressed or inactivated. Increasing evidence shows a strong correlation between Twist reactivation and both cancer progression and malignancy, where the transcriptional activities of Twist support cancer cells to disseminate from primary tumours and subsequently establish a secondary tumour growth in distant organs. However, it is largely unclear how this signalling programme is reactivated or what signalling pathways regulate its activity. The present review discusses recent advances in Twist regulation and activity, with a focus on phosphorylation-dependent Twist activity, potential upstream kinases and the contribution of these factors in transducing biological signals from upstream signalling complexes. The recent advances in these areas have shed new light on how phosphorylation-dependent regulation of the Twist proteins promotes or suppresses Twist activity, leading to differential regulation of Twist transcriptional targets and thereby influencing cell fate.

  12. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    International Nuclear Information System (INIS)

    Chang, Meng-Chu; Peng, Hsu-Hsia; Wu, Ming-Ting; Weng, Ken-Pen; Su, Mao-Yuan; Menza, Marius; Huang, Hung-Chieh

    2018-01-01

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  13. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Meng-Chu; Peng, Hsu-Hsia [National Tsing Hua University, Department of Biomedical Engineering and Environmental Sciences, Hsinchu (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China); National Yang-Ming University, Faculty of Medicine, Taipei (China); Weng, Ken-Pen [National Yang-Ming University, Faculty of Medicine, Taipei (China); Kaohsiung Veterans General Hospital, Department of Pediatrics, Kaohsiung (China); Shu-Zen Junior College of Medicine and Management, Department of Physical Therapy, Kaohsiung (China); Su, Mao-Yuan [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Menza, Marius [Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Department of Radiology, Medical Physics, Freiburg (Germany); Huang, Hung-Chieh [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China)

    2018-01-15

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  14. Extension-twist coupling of composite circular tubes with application to tilt rotor blade design

    Science.gov (United States)

    Nixon, Mark W.

    1987-01-01

    This investigation was conducted to determine if twist deformation required for the design of full-scale extension-twist-coupled tilt-rotor blades can be achieved within material design limit loads, and to demonstrate the accuracy of a coupled-beam analysis in predicting twist deformations. Two extension-twist-coupled tilt-rotor blade designs were developed based on theoretically optimum aerodynamic twist distributions. The designs indicated a twist rate requirement of between .216 and .333 deg/in. Agreement between axial tests and analytical predictions was within 10 percent at design limit loads. Agreement between the torsion tests and predictions was within 11 percent.

  15. Finite element and analytical models for twisted and coiled actuator

    Science.gov (United States)

    Tang, Xintian; Liu, Yingxiang; Li, Kai; Chen, Weishan; Zhao, Jianguo

    2018-01-01

    Twisted and coiled actuator (TCA) is a class of recently discovered artificial muscle, which is usually made by twisting and coiling polymer fibers into spring-like structures. It has been widely studied since discovery due to its impressive output characteristics and bright prospects. However, its mathematical models describing the actuation in response to the temperature are still not fully developed. It is known that the large tensile stroke is resulted from the untwisting of the twisted fiber when heated. Thus, the recovered torque during untwisting is a key parameter in the mathematical model. This paper presents a simplified model for the recovered torque of TCA. Finite element method is used for evaluating the thermal stress of the twisted fiber. Based on the results of the finite element analyses, the constitutive equations of twisted fibers are simplified to develop an analytic model of the recovered torque. Finally, the model of the recovered torque is used to predict the deformation of TCA under varying temperatures and validated against experimental results. This work will enhance our understanding of the deformation mechanism of TCAs, which will pave the way for the closed-loop position control.

  16. AKT-ions with a TWIST between EMT and MET.

    Science.gov (United States)

    Tang, Huifang; Massi, Daniela; Hemmings, Brian A; Mandalà, Mario; Hu, Zhengqiang; Wicki, Andreas; Xue, Gongda

    2016-09-20

    The transcription factor Twist is an important regulator of cranial suture during embryogenesis. Closure of the neural tube is achieved via Twist-triggered cellular transition from an epithelial to mesenchymal phenotype, a process known as epithelial-mesenchymal transition (EMT), characterized by a remarkable increase in cell motility. In the absence of Twist activity, EMT and associated phenotypic changes in cell morphology and motility can also be induced, albeit moderately, by other transcription factor families, including Snail and Zeb. Aberrant EMT triggered by Twist in human mammary tumour cells was first reported to drive metastasis to the lung in a metastatic breast cancer model. Subsequent analysis of many types of carcinoma demonstrated overexpression of these unique EMT transcription factors, which statistically correlated with worse outcome, indicating their potential as biomarkers in the clinic. However, the mechanisms underlying their activation remain unclear. Interestingly, increasing evidence indicates they are selectively activated by distinct intracellular kinases, thereby acting as downstream effectors facilitating transduction of cytoplasmic signals into nucleus and reprogramming EMT and mesenchymal-epithelial transition (MET) transcription to control cell plasticity. Understanding these relationships and emerging data indicating differential phosphorylation of Twist leads to complex and even paradoxical functionalities, will be vital to unlocking their potential in clinical settings.

  17. The influence of adrenergic stimulation on sex differences in left ventricular twist mechanics.

    Science.gov (United States)

    Williams, Alexandra M; Shave, Rob E; Cheyne, William S; Eves, Neil D

    2017-06-15

    Sex differences in left ventricular (LV) mechanics occur during acute physiological challenges; however, it is unknown whether sex differences in LV mechanics are fundamentally regulated by differences in adrenergic control. Using two-dimensional echocardiography and speckle tracking analysis, this study compared LV mechanics in males and females matched for LV length during post-exercise ischaemia (PEI) and β 1 -adrenergic receptor blockade. Our data demonstrate that while basal rotation was increased in males, LV twist was not significantly different between the sexes during PEI. In contrast, during β 1 -adrenergic receptor blockade, LV apical rotation, twist and untwisting velocity were reduced in males compared to females. Significant relationships were observed between LV twist and LV internal diameter and sphericity index in females, but not males. These findings suggest that LV twist mechanics may be more sensitive to alterations in adrenergic stimulation in males, but more highly influenced by ventricular structure and geometry in females. Sex differences in left ventricular (LV) mechanics exist at rest and during acute physiological stress. Differences in cardiac autonomic and adrenergic control may contribute to sex differences in LV mechanics and LV haemodynamics. Accordingly, this study aimed to investigate sex differences in LV mechanics with altered adrenergic stimulation achieved through post-handgrip-exercise ischaemia (PEI) and β 1 -adrenergic receptor (AR) blockade. Twenty males (23 ± 5 years) and 20 females (22 ± 3 years) were specifically matched for LV length (males: 8.5 ± 0.5 cm, females: 8.2 ± 0.6 cm, P = 0.163), and two-dimensional speckle-tracking echocardiography was used to assess LV structure and function at baseline, during PEI and following administration of 5 mg bisoprolol (β 1 -AR antagonist). During PEI, LV end-diastolic volume and stroke volume were increased in both groups (P adrenergic stimulation

  18. Fast Torsional Artificial Muscles from NiTi Twisted Yarns.

    Science.gov (United States)

    Mirvakili, Seyed M; Hunter, Ian W

    2017-05-17

    Torsional artificial muscles made of multiwalled carbon nanotube/niobium nanowire yarns have shown remarkable torsional speed and gravimetric torque. The muscle structure consists of a twisted yarn with half of its length infiltrated with a stimuli-responsive guest material such as paraffin wax. The volumetric expansion of the guest material creates the torsional actuation in the yarn. In the present work, we show that this type of actuation is not unique to wax-infiltrated carbon multiwalled nanotube (MWCNT) or niobium nanowire yarns and that twisted yarn of NiTi alloy fibers also produces fast torsional actuation. By gold-plating half the length of a NiTi twisted yarn and Joule heating it, we achieved a fully reversible torsional actuation of up to 16°/mm with peak torsional speed of 10 500 rpm and gravimetric torque of 8 N·m/kg. These results favorably compare to those of MWCNTs and niobium nanowire yarns.

  19. From starproducts to Drinfeld-twists. Present and future applications

    International Nuclear Information System (INIS)

    Koch, Florian

    2008-01-01

    Physics comes up with models that invoke noncommutative structures in configuration space. Such structures are dual to the deformed coalgebra sector of a represented symmetry algebra. In the mean time such deformations are performed in terms of the symmetry algebra itself via twists or quasitriangular structures. One might thus find oneself in the bad situation that the symmetry algebra is not large enough to provide the required twist that dually matches the noncommutative structure found. It thus has to remain in the unpleasant state of being without any notion of symmetry. We show how starproducts can be pushed to twists by introducing a larger algebra that accommodates any finite dimensional representation of a Lie-algebra. This new algebra is similar to a Heisenberg-algebra but in contrast to the latter can be enhanced to a Hopf-algebra. Some Examples are given. (author)

  20. Twisted vertex algebras, bicharacter construction and boson-fermion correspondences

    International Nuclear Information System (INIS)

    Anguelova, Iana I.

    2013-01-01

    The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras

  1. Iterative methods for overlap and twisted mass fermions

    International Nuclear Information System (INIS)

    Chiarappa, T.; Jansen, K.; Shindler, A.; Wetzorke, I.; Scorzato, L.; Urbach, C.; Wenger, U.

    2006-09-01

    We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass between 230 MeV and 720 MeV. For overlap fermions we address adaptive precision and low mode preconditioning while for twisted mass fermions we discuss even/odd preconditioning. Taking the best available algorithms in each case we find that calculations with the overlap operator are by a factor of 30-120 more expensive than with the twisted mass operator. (orig.)

  2. Iterative methods for overlap and twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Chiarappa, T. [Univ. di Milano Bicocca (Italy); Jansen, K.; Shindler, A.; Wetzorke, I. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Nagai, K.I. [Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik; Papinutto, M. [INFN Sezione di Roma Tre, Rome (Italy); Scorzato, L. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), Villazzano (Italy); Urbach, C. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Wenger, U. [ETH Zuerich (Switzerland). Inst. fuer Theoretische Physik

    2006-09-15

    We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass between 230 MeV and 720 MeV. For overlap fermions we address adaptive precision and low mode preconditioning while for twisted mass fermions we discuss even/odd preconditioning. Taking the best available algorithms in each case we find that calculations with the overlap operator are by a factor of 30-120 more expensive than with the twisted mass operator. (orig.)

  3. Template preparation of twisted nanoparticles of mesoporous silica

    Institute of Scientific and Technical Information of China (English)

    Kui Niu; Zhongbin Ni; Chengwu Fu; Tatsuo Kaneko; Mingqing Chen

    2011-01-01

    Optical isomers of N-lauroyl-L-(or-D-) alanine sodium salt {C12-L-(or-D-)AlaS} surfactants were used for the preparation of mesoporous silica nanoparticles with a twisted hexagonal rod-like morphology. Thermogravimetric analysis (TGA) was used to determine the temperature for template removal. Circular dichroism (CD) spectra of the surfactant solution with various compositions illustrated the formation and supramolecular assembly of protein-like molecular architecture leading to formation of twisted nanoparticles. Scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM)and X-ray powder diffraction (XRD) patterns of these as-synthesized mesoporous silica confirmed that the twisted morphology of these nanoparticles was closely related to the supramolecular-assembled complex of amino acid surfactants.

  4. Twisted spin Sutherland models from quantum Hamiltonian reduction

    International Nuclear Information System (INIS)

    Feher, L; Pusztai, B G

    2008-01-01

    Recent general results on Hamiltonian reductions under polar group actions are applied to study some reductions of the free particle governed by the Laplace-Beltrami operator of a compact, connected, simple Lie group. The reduced systems associated with arbitrary finite-dimensional irreducible representations of the group by using the symmetry induced by twisted conjugations are described in detail. These systems generically yield integrable Sutherland-type many-body models with spin, which are called twisted spin Sutherland models if the underlying twisted conjugations are built on non-trivial Dynkin diagram automorphisms. The spectra of these models can be calculated, in principle, by solving certain Clebsch-Gordan problems, and the result is presented for the models associated with the symmetric tensorial powers of the defining representation of SU(N)

  5. Reversible Twisting of Primary Amides via Ground State N-C(O) Destabilization: Highly Twisted Rotationally Inverted Acyclic Amides.

    Science.gov (United States)

    Meng, Guangrong; Shi, Shicheng; Lalancette, Roger; Szostak, Roman; Szostak, Michal

    2018-01-17

    Since the seminal studies by Pauling in 1930s, planarity has become the defining characteristic of the amide bond. Planarity of amides has central implications for the reactivity and chemical properties of amides of relevance to a range of chemical disciplines. While the vast majority of amides are planar, nonplanarity has a profound effect on the properties of the amide bond, with the most common method to restrict the amide bond relying on the incorporation of the amide function into a rigid cyclic ring system. In a major departure from this concept, here, we report the first class of acyclic twisted amides that can be prepared, reversibly, from common primary amides in a single, operationally trivial step. Di-tert-butoxycarbonylation of the amide nitrogen atom yields twisted amides in which the amide bond exhibits nearly perpendicular twist. Full structural characterization of a range of electronically diverse compounds from this new class of twisted amides is reported. Through reactivity studies we demonstrate unusual properties of the amide bond, wherein selective cleavage of the amide bond can be achieved by a judicious choice of the reaction conditions. Through computational studies we evaluate structural and energetic details pertaining to the amide bond deformation. The ability to selectively twist common primary amides, in a reversible manner, has important implications for the design and application of the amide bond nonplanarity in structural chemistry, biochemistry and organic synthesis.

  6. Looking at the gluon moment of the nucleon with dynamical twisted mass fermions

    International Nuclear Information System (INIS)

    Alexandrou, Constantia; Cyprus Institute, Nicosia; Drach, Vincent; Wiese, Christian; Hadjiyiannakou, Kyriakos; Jansen, Karl; Deutsches Elektronen-Synchrotron; Kostrzewa, Bartosz

    2013-11-01

    To understand the structure of hadrons it is important to know the PDF of their constituents, the quarks and gluons. In our work we aim to compute the first moment of the gluon PDF left angle x right angle g for the nucleon. We follow two possible approaches in order to extract the gluon moment: the Feynman-Hellmann theorem and a direct method with smearing of the gluon operator. We present preliminary results computed on 24 3 x 48 lattices for the case where the Feynman-Hellman theorem is used and 32 3 x 64 lattices for the direct method, employing N f =2+1+1 maximally twisted mass fermions.

  7. Colombian ancillary services and international connections: Current weaknesses and policy challenges

    International Nuclear Information System (INIS)

    Carvajal, S.X.; Serrano, J.; Arango, S.

    2013-01-01

    Ancillary services are required to maintain the unity, stability, and quality of power systems. In Colombia these services are required to operate the national power system and the international connections with the neighboring countries. The system is influenced by factors ranging from system's topology to social and political aspects, such as the large number of terrorist attacks. In light of these particularities, we consider Colombia as a learning lab for ancillary services in the region. Colombia's power system relies on three ancillary services for its operation, namely frequency regulation, voltage control, and blackstart service. From 2010 Special Protection Systems were also added. In this paper we first analyze the technical aspects, operational restrictions, financial management, and the most relevant regulatory conditions of these ancillary services of the SIN. We also take into consideration the main regulatory characteristics and statistical data related to energy exchanges that have taken place between Colombia and Venezuela and Ecuador. Thereafter, we depict the main weaknesses and policy challenges that Colombia must address in order to increase the effectiveness and coverage of ancillary services in both the SIN and in the international interconnections. Finally, we propose new market oriented regulations to encourage investments and new tools for international connections. - Highlights: ► Blackout of 2007 forces Colombian regulator to improve security of power system. ► Four ancillary services are currently used for secure operation of Colombian system. ► Special Protection Systems service added in 2010. ► Frequency control is the only remunerated service in Colombia. ► Legislation should exist for remuneration of voltage control and black start services.

  8. Coordinated Control Scheme for Ancillary Services from Offshore Wind Power Plants to AC and DC Grids

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Altin, Müfit; Hansen, Anca Daniela

    2016-01-01

    This paper proposes a new approach of providing ancillary services to AC and DC grids from offshore wind power plants (OWPPs), connected through multi-terminal HVDC network. A coordinated control scheme where OWPP’s AC grid frequency modulated according to DC grid voltage variations is used...... to detect and provide the ancillary service requirements of both AC and DC grids, is proposed in this paper. In particular, control strategies for onshore frequency control, fault ridethrough support in the onshore grid, and DC grid voltage control are considered. The proposed control scheme involves only...

  9. Loads Providing Ancillary Services: Review of InternationalExperience-- Technical Appendix: Market Descriptions

    Energy Technology Data Exchange (ETDEWEB)

    Grayson Heffner, Charles Goldman, Kintner-Meyer, M; Kirby, Brendan

    2007-05-01

    In this study, we examine the arrangements for andexperiences of end-use loads providing ancillary services (AS) in fiveelectricity markets: Australia, the United Kingdom (UK), the Nordicmarket, and the ERCOT and PJM markets in the United States. Our objectivein undertaking this review of international experience was to identifyspecific approaches or market designs that have enabled customer loads toeffectively deliver various ancillary services (AS) products. We hopethat this report will contribute to the ongoing discussion in the U.S.and elsewhere regarding what institutional and technical developments areneeded to ensure that customer loads can meaningfully participate in allwholesale electricity markets.

  10. Borel resummation of soft gluon radiation and higher twists

    International Nuclear Information System (INIS)

    Forte, Stefano; Ridolfi, Giovanni; Rojo, Joan; Ubiali, Maria

    2006-01-01

    We show that the well-known divergence of the perturbative expansion of resummed results for processes such as deep-inelastic scattering and Drell-Yan in the soft limit can be treated by Borel resummation. The divergence in the Borel inversion can be removed by the inclusion of suitable higher twist terms. This provides us with an alternative to the standard 'minimal prescription' for the asymptotic summation of the perturbative expansion, and it gives us some handle on the role of higher twist corrections in the soft resummation region

  11. Modeling higher twist contributions to deep inelastic scattering with diquarks

    International Nuclear Information System (INIS)

    Anselmino, M.

    1994-01-01

    The most recent detailed data on the unpolarized nucleon structure functions allow a precise determination of higher twist contributions. Quark-quark correlations induced by color forces are expected to be a natural explanation for such effects; indeed, a quark-diquark picture of the nucleon, previously introduced in the description of several exclusive processes at intermediate Q 2 values, is found to model the proton higher twist data with great accuracy. The resulting parameters are consistent with the diquark properties suggested by other experimental and theoretical analyses. (author)

  12. Modelling higher twist contributions to deep inelastic scattering with diquarks

    International Nuclear Information System (INIS)

    Anselmino, M.; Caruso, F.; Penna Firme, A.; Soares, J.; Mello Neto, J.R.T. de

    1994-08-01

    The most recent detailed data on the unpolarized nucleon structure functions allow a precise determination of higher twist contributions. Quark-quark correlations induced by colour forces are expected to be a natural explanation for such effects: indeed, a quark-diquark picture of the nucleon, previously introduced in the description of several exclusive processes at intermediate Q 2 values, is found to model the proton higher twist data with great accuracy. The resulting parameters are consistent with the diquark properties suggested by other experimental and theoretical analyses. (author). 15 refs, 5 figs

  13. Anomalous phase shift in a twisted quantum loop

    International Nuclear Information System (INIS)

    Taira, Hisao; Shima, Hiroyuki

    2010-01-01

    The coherent motion of electrons in a twisted quantum ring is considered to explore the effect of torsion inherent to the ring. Internal torsion of the ring composed of helical atomic configuration yields a non-trivial quantum phase shift in the electrons' eigenstates. This torsion-induced phase shift causes novel kinds of persistent current flow and an Aharonov-Bohm-like conductance oscillation. The two phenomena can occur even when no magnetic flux penetrates inside the twisted ring, thus being in complete contrast with the counterparts observed in untwisted rings.

  14. Note on twisted elliptic genus of K3 surface

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Tohru, E-mail: eguchi@yukawa.kyoto-u.ac.j [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Hikami, Kazuhiro, E-mail: KHikami@gmail.co [Department of Mathematics, Naruto University of Education, Tokushima 772-8502 (Japan)

    2011-01-03

    We discuss the possibility of Mathieu group M{sub 24} acting as symmetry group on the K3 elliptic genus as proposed recently by Ooguri, Tachikawa and one of the present authors. One way of testing this proposal is to derive the twisted elliptic genera for all conjugacy classes of M{sub 24} so that we can determine the unique decomposition of expansion coefficients of K3 elliptic genus into irreducible representations of M{sub 24}. In this Letter we obtain all the hitherto unknown twisted elliptic genera and find a strong evidence of Mathieu moonshine.

  15. Note on twisted elliptic genus of K3 surface

    International Nuclear Information System (INIS)

    Eguchi, Tohru; Hikami, Kazuhiro

    2011-01-01

    We discuss the possibility of Mathieu group M 24 acting as symmetry group on the K3 elliptic genus as proposed recently by Ooguri, Tachikawa and one of the present authors. One way of testing this proposal is to derive the twisted elliptic genera for all conjugacy classes of M 24 so that we can determine the unique decomposition of expansion coefficients of K3 elliptic genus into irreducible representations of M 24 . In this Letter we obtain all the hitherto unknown twisted elliptic genera and find a strong evidence of Mathieu moonshine.

  16. Stability of short wavelength tearing and twisting modes

    International Nuclear Information System (INIS)

    Waelbroeck, F.L.

    1998-01-01

    The stability and mutual interaction of tearing and twisting modes in a torus is governed by matrices that generalize the well-known Δ' stability index. The diagonal elements of these matrices determine the intrinsic stability of modes that reconnect the magnetic field at a single resonant surface. The off-diagonal elements indicate the strength of the coupling between the different modes. The author shows how the elements of these matrices can be evaluated, in the limit of short wavelength, from the free energy driving radially extended ballooning modes. The author applies the results by calculating the tearing and twisting Δ' for a model high-beta equilibrium with circular flux surfaces

  17. Gerbes over posets and twisted C*-dynamical systems

    OpenAIRE

    Vasselli, Ezio

    2017-01-01

    A base $\\Delta$ generating the topology of a space $M$ becomes a partially ordered set (poset), when ordered under inclusion of open subsets. Given a precosheaf over $\\Delta$ of fixed-point spaces (typically C*-algebras) under the action of a group $G$, in general one cannot find a precosheaf of $G$-spaces having it as fixed-point precosheaf. Rather one gets a gerbe over $\\Delta$, that is, a "twisted precosheaf" whose twisting is encoded by a cocycle with coefficients in a suitable 2-group. W...

  18. Geometry of the toroidal N-helix: optimal-packing and zero-twist

    DEFF Research Database (Denmark)

    Olsen, Kasper; Bohr, Jakob

    2012-01-01

    Two important geometrical properties of N-helix structures are influenced by bending. One is maximizing the volume fraction, which is called optimal-packing, and the other is having a vanishing strain-twist coupling, which is called zero-twist. Zero-twist helices rotate neither in one nor...... helix. General N-helices are discussed, as well as zero-twist helices for N > 1. The derived geometrical restrictions are gradually modified by changing the aspect ratio of the torus....

  19. On the space of connections having non-trivial twisted harmonic spinors

    International Nuclear Information System (INIS)

    Bei, Francesco; Waterstraat, Nils

    2015-01-01

    We consider Dirac operators on odd-dimensional compact spin manifolds which are twisted by a product bundle. We show that the space of connections on the twisting bundle which yields an invertible operator has infinitely many connected components if the untwisted Dirac operator is invertible and the dimension of the twisting bundle is sufficiently large

  20. Twisting failure of centrally loaded open-section columns in the elastic range

    Science.gov (United States)

    Kappus, Robert

    1938-01-01

    In the following report a complete theory of twisting failure by the energy method is developed, based on substantially the same assumptions as those employed by Wagner and Bleich. Problems treated in detail are: the stress and strain condition under St. Venant twist and in twist with axial constraint; the concept of shear center and the energy method for problems of elastic stability.

  1. On the space of connections having non-trivial twisted harmonic spinors

    Energy Technology Data Exchange (ETDEWEB)

    Bei, Francesco, E-mail: bei@math.hu-berlin.de [Institut für Mathematik, Humboldt Universität zu Berlin, Unter den Linden 6, 10099 Berlin (Germany); Waterstraat, Nils, E-mail: n.waterstraat@kent.ac.uk [School of Mathematics, Statistics & Actuarial Science, University of Kent, Canterbury, Kent CT2 7NF (United Kingdom)

    2015-09-15

    We consider Dirac operators on odd-dimensional compact spin manifolds which are twisted by a product bundle. We show that the space of connections on the twisting bundle which yields an invertible operator has infinitely many connected components if the untwisted Dirac operator is invertible and the dimension of the twisting bundle is sufficiently large.

  2. 29 CFR 2550.408b-6 - Statutory exemption for ancillary services by a bank or similar financial institution.

    Science.gov (United States)

    2010-07-01

    ....408b-6 Statutory exemption for ancillary services by a bank or similar financial institution. (a) In... service is consistent with sound banking and financial practice, as determined by Federal or State... 29 Labor 9 2010-07-01 2010-07-01 false Statutory exemption for ancillary services by a bank or...

  3. 78 FR 46177 - Third-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric...

    Science.gov (United States)

    2013-07-30

    ...-Party Provision of Ancillary Services; Accounting and Financial Reporting for New Electric Storage... Financial Reporting for New Electric Storage Technologies, Notice of Proposed Rulemaking, FERC Stats. & Regs... Commission 18 CFR Parts 35 and 101 Third-Party Provision of Ancillary Services; Accounting and Financial...

  4. Mechanisms of Twist 1-Induced Invasion in Breast Cancer Metastasis

    Science.gov (United States)

    2011-01-01

    affect breast cancer metastasis with a subcutaneous mouse tumor implantation model of breast cancer metastasis. HMLE -Twist1 cells expressing shRNAs...13 4 Introduction Distant metastases are responsible for the vast majority of breast cancer deaths. This process...to migrate and invade is therefore essential to the metastatic process. The initial steps of breast cancer metastasis, local invasion and

  5. Determinant of twisted chiral Dirac operator on the lattice

    International Nuclear Information System (INIS)

    Fosco, C.D.; Randjbar Daemi, S.

    1995-04-01

    Using the overlap formulation, we calculate the fermionic determinant on the lattice for chiral fermions with twisted boundary conditions in two dimensions. When the lattice spacing tends to zero we recover the results on the usual string-theory continuum calculations. (author). 13 refs

  6. Stability of coupled tearing and twisting modes in tokamaks

    International Nuclear Information System (INIS)

    Fitzpatrick, R.

    1994-03-01

    A dispersion relation is derived for resistive modes of arbitrary parity in a tokamak plasma. At low mode amplitude, tearing and twisting modes which have nonideal MHD behavior at only one rational surface at a time in the plasma are decoupled via sheared rotation and diamagnetic flows. At higher amplitude, more unstable open-quote compound close-quote modes develop which have nonideal behavior simultaneously at many surfaces. Such modes possess tearing parity layers at some of the nonideal surfaces, and twisting parity layers at others, but mixed parity layers are generally disallowed. At low mode number, open-quote compound close-quote modes are likely to have tearing parity layers at all of the nonideal surfaces in a very low-β plasma, but twisting parity layers become more probable as the plasma β is increased. At high mode number, unstable twisting modes which exceed a critical amplitude drive conventional magnetic island chains on alternate rational surfaces, to form an interlocking structure in which the O-points and X-points of neighboring chains line up

  7. Spectral estimates for Dirichlet Laplacians on perturbed twisted tubes

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Barseghyan, Diana

    2014-01-01

    Roč. 8, č. 1 (2014), s. 167-183 ISSN 1846-3886 R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Drichlet Laplacian * twisted tube * discrete spectrum * eigenvalue estimates Subject RIV: BE - Theoretical Physics Impact factor: 0.583, year: 2014

  8. Casimir energy for twisted piecewise uniform bosonic strings

    International Nuclear Information System (INIS)

    Lu, J.; Huang, B.; Shanghai, Teachers Univ.

    1998-01-01

    The Casimir energy for the transverse oscillations of piecewise uniform bosonic strings with either untwisted or twisted continuous conditions is discussed. After calculating the analytic values of zeros of the dispersion function under certain conditions, is obtained the Casimir energy for both open and closed bosonic strings composed of two or three segments

  9. Twisted equivariant K-theory, groupoids and proper actions

    OpenAIRE

    Cantarero, Jose

    2009-01-01

    In this paper we define twisted equivariant K-theory for actions of Lie groupoids. For a Bredon-compatible Lie groupoid, this defines a periodic cohomology theory on the category of finite CW-complexes with equivariant stable projective bundles. A classification of these bundles is shown. We also obtain a completion theorem and apply these results to proper actions of groups.

  10. Fermionic construction of vertex operators for twisted affine algebras

    International Nuclear Information System (INIS)

    Frappat, L.; Sorba, P.; Sciarrino, A.

    1988-03-01

    We construct vertex operator representations of the twisted affine algebras in terms of fermionic (or parafermionic in some cases) elementary fields. The folding method applied to the extended Dynkin diagrams of the affine algebras allows us to determine explicitly these fermionic fields as vertex operators

  11. Heat bath method for the twisted Eguchi-Kawai model

    International Nuclear Information System (INIS)

    Fabricius, K.; Haan, O.

    1984-01-01

    We reformulate the twisted Eguchi-Kawaii model in a way that allows us to use the heat bath method for the updating procedure of the link matrices. This new formulation is more efficient by a factor of 2.5 in computer time and of 2.3 in memory need. (orig.)

  12. Heat bath method for the twisted Eguchi-Kawai model

    Energy Technology Data Exchange (ETDEWEB)

    Fabricius, K.; Haan, O.

    1984-08-16

    We reformulate the twisted Eguchi-Kawaii model in a way that allows us to use the heat bath method for the updating procedure of the link matrices. This new formulation is more efficient by a factor of 2.5 in computer time and of 2.3 in memory need.

  13. Twisted mass lattice QCD with non-degenerate quark masses

    International Nuclear Information System (INIS)

    Muenster, Gernot; Sudmann, Tobias

    2006-01-01

    Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term is considered in the framework of chiral perturbation theory. For two and three numbers of quark flavours, respectively, with non-degenerate quark masses the pseudoscalar meson masses and decay constants are calculated in next-to-leading order including lattice effects quadratic in the lattice spacing a

  14. Twist-2 Light-Cone Pion Wave Function

    OpenAIRE

    Belyaev, V. M.; Johnson, Mikkel B.

    1997-01-01

    We present an analysis of the existing constraints for the twist-2 light-cone pion wave function. We find that existing information on the pion wave function does not exclude the possibility that the pion wave function attains its asymptotic form. New bounds on the parameters of the pion wave function are presented.

  15. Optimal Sizing and Allocation of Residential Photovoltaic Panels in a Distribution Network for Ancillary Services Application

    DEFF Research Database (Denmark)

    Kordheili, Reza Ahmadi; Pourmousavi, Ali; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    requirements, such as voltage and current limits. This paper proposes an optimization method for determining the number of photovoltaic (PV) panels together with their arrangement in the grid in order to maximize ancillary service, without violating grid operation limits. The proposed optimization method...

  16. Ethics of Ancillary Care in Clinical Trials in Low Income Countries: A ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    income countries where HIV incidence is high, but the benefits of research are ... provision of ancillary care – medical care provided to clinical trial participants during a ... to or use of quality delivery services is an issue of ... with drastically reduced costs, questions arise over .... The 'partial entrustment' model differentiates.

  17. Enhancing the Role of Electric Vehicles in the Power Grid: Field Validation of Multiple Ancillary Services

    DEFF Research Database (Denmark)

    Knezovic, Katarina; Martinenas, Sergejus; Andersen, Peter Bach

    2016-01-01

    essentially means it is applicable to any EV complying with IEC 61851 and SAE J1772 standards. The field test validation is conducted in a real Danish distribution grid with a Nissan Leaf providing three ancillary services through unidirectional AC charging, namely congestion management, local voltage support...

  18. Evaluation of three ancillary treatments in the management of equine grass sickness.

    Science.gov (United States)

    Fintl, C; McGorum, B C

    2002-09-28

    Brotizolam, acetylcysteine and aloe vera gel were evaluated as ancillary treatments for 29 cases of equine grass sickness. None of the treatments had any significant beneficial effect on the survival of the horses. However, 11 of 13 horses with mild chronic grass sickness survived solely with intensive nursing care.

  19. Management of Ovarian Cysts by Laparoscopic Extracorporeal Approach Using Single Ancillary Trocar

    Directory of Open Access Journals (Sweden)

    Metin Capar

    2009-12-01

    Conclusion: This technique does not require the use of two or more ancillary trocars or widening of the trocar incision. The duration of surgery can be shortened considerably and complete excision of the cystic capsule can be performed. Homeostasis was achieved using 3-0 polyglactin sutures. No electrocoagulation was required.

  20. Island operation capability in the Colombian electrical market: a promising ancillary service of distributed energy resources

    DEFF Research Database (Denmark)

    Marín-Jiménez, Juan D.; Carvajal-Quintero, Sandra; Guerrero, Josep M.

    2018-01-01

    is presented. Subsequently, an existing electrical distribution system with small hydropower plants is considered as a study case in order to identify the technical requirements set out for both, the distribution system and the generation source. Finally, taking into account the current Law and regulations......, a proposal is outlined for the implementation of the island operation capability ancillary service in the Colombian electrical system....

  1. 30 CFR 250.207 - What ancillary activities may I conduct?

    Science.gov (United States)

    2010-07-01

    ... surveys; or (c) Studies that model potential oil and hazardous substance spills, drilling muds and... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What ancillary activities may I conduct? 250.207 Section 250.207 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE...

  2. Ancillary obligations as an additional obligation of a limited liability company's member

    Directory of Open Access Journals (Sweden)

    Marjanski Vladimir Ž.

    2016-01-01

    Full Text Available Ancillary obligation can be defined as an obligation of a limited liability company's member undertaken through the instrument of incorporation, which can take the form of monetary or non-monetary obligation (usually it is an obligation of a non-monetary character, which has a certain financial value and can be the object of a legally valid obligation. Ancillary obligations, as a contribution to activities of the company, are not regulated in the Law on Companies. The legal nature of this obligation is different from the obligation to make a contribution in money or in kind to a company's assets, to make additional pay-ins or from the landing of funds to the company. Ancillary obligation is an optional and additional obligation of a limited liability company's member and the obligation itself and its contents is defined in the instrument of incorporation. When a limited liability company's member undertakes an ancillary obligation this creates a distinctive relationship between the member and the company, concerning their respective obligations and the legal status of the company, as well as certain consequences derived from those obligations.

  3. Regulatory issues associated with closure of the Hanford AX Tank Farm ancillary equipment

    International Nuclear Information System (INIS)

    Becker, D.L.

    1998-01-01

    Liquid mixed, high-level radioactive waste has been stored in underground single-shell tanks at the US Department of Energy's (DOE's) Hanford Site. After retrieval of the waste from the single-shell tanks, the DOE will proceed with closure of the tank farm. The 241-AX Tank Farm includes four one-million gallon single-shell tanks in addition to sluice lines, transfer lines, ventilation headers, risers, pits, cribs, catch tanks, buildings, well and associated buried piping. This equipment is classified as ancillary equipment. This document addresses the requirements for regulatory close of the ancillary equipment in the Hanford Site 241-AX Tank Farm. The options identified for physical closure of the ancillary equipment include disposal in place, disposal in place after treatment, excavation and disposal on site in an empty single-shell tank, and excavation and disposal outside the AX Tank Farm. The document addresses the background of the Hanford Site and ancillary equipment in the AX Tank Farm, regulations for decontamination and decommissioning of radioactively contaminated equipment, requirements for the cleanup and disposal of radioactive wastes, cleanup and disposal requirements governing hazardous and mixed waste, and regulatory requirements and issues associated with each of the four physical closure options. This investigation was conducted by the Sandia National Laboratories, Albuquerque, New Mexico, during Fiscal Year 1998 for the Hanford Tanks Initiative Project

  4. Mixed integer non-linear programming and Artificial Neural Network based approach to ancillary services dispatch in competitive electricity markets

    International Nuclear Information System (INIS)

    Canizes, Bruno; Soares, João; Faria, Pedro; Vale, Zita

    2013-01-01

    Highlights: • Ancillary services market management. • Ancillary services requirements forecast based on Artificial Neural Network. • Ancillary services clearing mechanisms without complex bids and with complex bids. - Abstract: Ancillary services represent a good business opportunity that must be considered by market players. This paper presents a new methodology for ancillary services market dispatch. The method considers the bids submitted to the market and includes a market clearing mechanism based on deterministic optimization. An Artificial Neural Network is used for day-ahead prediction of Regulation Down, regulation-up, Spin Reserve and Non-Spin Reserve requirements. Two test cases based on California Independent System Operator data concerning dispatch of Regulation Down, Regulation Up, Spin Reserve and Non-Spin Reserve services are included in this paper to illustrate the application of the proposed method: (1) dispatch considering simple bids; (2) dispatch considering complex bids

  5. Applying the variety reduction principle to management of ancillary services

    NARCIS (Netherlands)

    Elkhuizen, Sylvia G.; van Sambeek, Jasper R. C.; Hans, Erwin W.; Krabbendam, Koos (J. J. ); Bakker, Piet J. M.

    2007-01-01

    BACKGROUND: As central diagnostic facilities, computer tomography (CT) scans appear to be bottlenecks in many patient-care processes. This study describes a case study concerning redesign of a CT scan department in the Academic Medical Center in Amsterdam, the Netherlands. PURPOSES: The aim was to

  6. Controlling coupled bending-twisting vibrations of anisotropic composite wing

    Science.gov (United States)

    Ryabov, Victor; Yartsev, Boris

    2018-05-01

    The paper discusses the possibility to control coupled bending-twisting vibrations of anisotropic composite wing by means of the monoclinic structures in the reinforcement of the plating. Decomposing the potential straining energy and kinetic energy of natural vibration modes into interacting and non-interacting parts, it became possible to introduce the two coefficients that integrally consider the effect of geometry and reinforcement structure upon the dynamic response parameters of the wing. The first of these coefficients describes the elastic coupling of the natural vibration modes, the second coefficient describes the inertial one. The paper describes the numerical studies showing how the orientation of considerably anisotropic CRP layers in the plating affects natural frequencies, loss factors, coefficients of elastic and inertial coupling for several lower tones of natural bending-twisting vibrations of the wing. Besides, for each vibration mode, partial values of the above mentioned dynamic response parameters were determined by means of the relationships for orthotropic structures where instead of "free" shearing modulus in the reinforcement plant, "pure" shearing modulus is used. Joint analysis of the obtained results has shown that each pair of bending-twisting vibration modes has its orientation angle ranges of the reinforcing layers where the inertial coupling caused by asymmetry of the cross-section profile with respect to the main axes of inertia decreases, down to the complete extinction, due to the generation of the elastic coupling in the plating material. These ranges are characterized by the two main features: 1) the difference in the natural frequencies of the investigated pair of bending-twisting vibration modes is the minimum and 2) natural frequencies of bending-twisting vibrations belong to a stretch restricted by corresponding partial natural frequencies of the investigated pair of vibration modes. This result is of practical importance

  7. Intermittent energy bursts and recurrent topological change of a twisting magnetic flux tube

    International Nuclear Information System (INIS)

    Amo, Hiroyoshi; Sato, Tetsuya; Kageyama, Akira.

    1994-09-01

    When continuously twisted, a magnetic flux tube suffers a large kink distortion in the middle part of the tube, like a knot-of-tension instability of a bundle of twisted rubber strings, and reconnection is triggered starting with the twisted field lines and quickly proceeding to the untwisted field lines at the twist-untwist boundary, whereby a giant burst-like energy release takes place. Subsequently, bursts occur intermittently and reconnection advances deeper into the untwisted region. Then, a companion pair of the linked twist-untwist flux tubes reconnect with each other to return to the original axisymmetric tube. The process is thus repeatable. (author)

  8. Automatic O(a) improvement for twisted mass QCD in the presence of spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    Aoki, Sinya; Baer, Oliver

    2006-01-01

    In this paper we present a proof for automatic O(a) improvement in twisted mass lattice QCD at maximal twist, which uses only the symmetries of the leading part in the Symanzik effective action. In the process of the proof we clarify that the twist angle is dynamically determined by vacuum expectation values in the Symanzik theory. For maximal twist according to this definition, we show that scaling violations of all quantities which have nonzero values in the continuum limit are even in a. In addition, using Wilson chiral perturbation theory, we investigate this definition for maximal twist and compare it to other definitions which were already employed in actual simulations

  9. Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines

    International Nuclear Information System (INIS)

    Ohkuma, Mizue; Funato, Noriko; Higashihori, Norihisa; Murakami, Masanori; Ohyama, Kimie; Nakamura, Masataka

    2007-01-01

    TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-κB sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells

  10. Optimized chord and twist angle distributions of wind turbine blade considering Reynolds number effects

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.; Tang, X. [Univ. of Central Lancashire. Engineering and Physical Sciences, Preston (United Kingdom); Liu, X. [Univ. of Cumbria. Sustainable Engineering, Workington (United Kingdom)

    2012-07-01

    The aerodynamic performance of a wind turbine depends very much on its blade geometric design, typically based on the blade element momentum (BEM) theory, which divides the blade into several blade elements. In current blade design practices based on Schmitz rotor design theory, the blade geometric parameters including chord and twist angle distributions are determined based on airfoil aerodynamic data at a specific Reynolds number. However, rotating wind turbine blade elements operate at different Reynolds numbers due to variable wind speed and different blade span locations. Therefore, the blade design through Schmitz rotor theory at a specific Reynolds number does not necessarily provide the best power performance under operational conditions. This paper aims to provide an optimal blade design strategy for horizontal-axis wind turbines operating at different Reynolds numbers. A fixed-pitch variable-speed (FPVS) wind turbine with S809 airfoil is chosen as a case study and a Matlab program which considers Reynolds number effects is developed to determine the optimized chord and twist angle distributions of the blade. The performance of the optimized blade is compared with that of the preliminary blade which is designed based on Schmitz rotor design theory at a specific Reynolds number. The results demonstrate that the proposed blade design optimization strategy can improve the power performance of the wind turbine. This approach can be further developed for any practice of horizontal axis wind turbine blade design. (Author)

  11. Dynamic testing and analysis of extension-twist-coupled composite tubular spars

    Science.gov (United States)

    Lake, Renee C.; Izapanah, Amir P.; Baucon, Robert M.

    The results from a study aimed at improving the dynamic and aerodynamic characteristics of composite rotor blades through the use of extension-twist elastic coupling are presented. A set of extension-twist-coupled composite tubular spars, representative of the primary load carrying structure within a helicopter rotor blade, was manufactured using four plies of woven graphite/epoxy cloth 'prepreg.' These spars were non-circular in cross section design and were therefore subject to warping deformations. Three cross-sectional geometries were developed: square, D-shape, and flattened ellipse. Results from free-free vibration tests of the spars were compared with results from normal modes and frequency analyses of companion shell-finite-element models developed in MSC/NASTRAN. Five global or 'non-shell' modes were identified within the 0-2000 Hz range for each spar. The frequencies and associated mode shapes for the D-shape spar were correlated with analytical results, showing agreement within 13.8 percent. Frequencies corresponding to the five global mode shapes for the square spar agreed within 9.5 percent of the analytical results. Five global modes were similarly identified for the elliptical spar and agreed within 4.9 percent of the respective analytical results.

  12. Dynamic testing and analysis of extension-twist-coupled composite tubular spars

    Science.gov (United States)

    Lake, Renee C.; Izapanah, Amir P.; Baucon, Robert M.

    1992-01-01

    The results from a study aimed at improving the dynamic and aerodynamic characteristics of composite rotor blades through the use of extension-twist elastic coupling are presented. A set of extension-twist-coupled composite tubular spars, representative of the primary load carrying structure within a helicopter rotor blade, was manufactured using four plies of woven graphite/epoxy cloth 'prepreg.' These spars were non-circular in cross section design and were therefore subject to warping deformations. Three cross-sectional geometries were developed: square, D-shape, and flattened ellipse. Results from free-free vibration tests of the spars were compared with results from normal modes and frequency analyses of companion shell-finite-element models developed in MSC/NASTRAN. Five global or 'non-shell' modes were identified within the 0-2000 Hz range for each spar. The frequencies and associated mode shapes for the D-shape spar were correlated with analytical results, showing agreement within 13.8 percent. Frequencies corresponding to the five global mode shapes for the square spar agreed within 9.5 percent of the analytical results. Five global modes were similarly identified for the elliptical spar and agreed within 4.9 percent of the respective analytical results.

  13. A torsional artificial muscle from twisted nitinol microwire

    Science.gov (United States)

    Mirvakili, Seyed M.; Hunter, Ian W.

    2017-04-01

    Nitinol microwires of 25 μm in diameter can have tensile actuation of up to 4.5% in less than 100 ms. A work density of up to 480 MPa can be achieved from these microwires. In the present work, we are showing that by twisting the microwires in form of closed-loop two-ply yarn we can create a torsional actuator. We achieved a revisable torsional stroke of 46°/mm with peak rotational speed of up to 10,000 rpm. We measured a gravimetric torque of up to 28.5 N•m/kg which is higher than the 3 - 6 N•m/kg for direct-drive commercial electric motors. These remarkable performance results are comparable to those of guest-infiltrated carbon nanotube twisted yarns.

  14. Twisted-Light-Ion Interaction: The Role of Longitudinal Fields

    Science.gov (United States)

    Quinteiro, G. F.; Schmidt-Kaler, Ferdinand; Schmiegelow, Christian T.

    2017-12-01

    The propagation of light beams is well described using the paraxial approximation, where field components along the propagation direction are usually neglected. For strongly inhomogeneous or shaped light fields, however, this approximation may fail, leading to intriguing variations of the light-matter interaction. This is the case of twisted light having opposite orbital and spin angular momenta. We compare experimental data for the excitation of a quadrupole transition in a single trapped 40Ca+ ion from Schmiegelow et al. [Nat. Commun. 7, 12998 (2016), 10.1038/ncomms12998] with a complete model where longitudinal components of the electric field are taken into account. Our model matches the experimental data and excludes by 11 standard deviations the approximation of a complete transverse field. This demonstrates the relevance of all field components for the interaction of twisted light with matter.

  15. Nonsnaking doubly diffusive convectons and the twist instability

    Energy Technology Data Exchange (ETDEWEB)

    Beaume, Cédric, E-mail: ced.beaume@gmail.com; Knobloch, Edgar, E-mail: knobloch@berkeley.edu [Department of Physics, University of California, Berkeley, California 94720 (United States); Bergeon, Alain, E-mail: alain.bergeon@imft.fr [Université de Toulouse, INPT, UPS, IMFT (Institut de Mécanique des Fluides de Toulouse), Allée Camille Soula, F-31400 Toulouse, France and CNRS, IMFT, F-31400 Toulouse (France)

    2013-11-15

    Doubly diffusive convection in a three-dimensional horizontally extended domain with a square cross section in the vertical is considered. The fluid motion is driven by horizontal temperature and concentration differences in the transverse direction. When the buoyancy ratio N = −1 and the Rayleigh number is increased the conduction state loses stability to a subcritical, almost two-dimensional roll structure localized in the longitudinal direction. This structure exhibits abrupt growth in length near a particular value of the Rayleigh number but does not snake. Prior to this filling transition the structure becomes unstable to a secondary twist instability generating a pair of stationary, spatially localized zigzag states. In contrast to the primary branch these states snake as they grow in extent and eventually fill the whole domain. The origin of the twist instability and the properties of the resulting localized structures are investigated for both periodic and no-slip boundary conditions in the extended direction.

  16. Helicity conservation and twisted Seifert surfaces for superfluid vortices.

    Science.gov (United States)

    Salman, Hayder

    2017-04-01

    Starting from the continuum definition of helicity, we derive from first principles its different contributions for superfluid vortices. Our analysis shows that an internal twist contribution emerges naturally from the mathematical derivation. This reveals that the spanwise vector that is used to characterize the twist contribution must point in the direction of a surface of constant velocity potential. An immediate consequence of the Seifert framing is that the continuum definition of helicity for a superfluid is trivially zero at all times. It follows that the Gauss-linking number is a more appropriate definition of helicity for superfluids. Despite this, we explain how a quasi-classical limit can arise in a superfluid in which the continuum definition for helicity can be used. This provides a clear connection between a microscopic and a macroscopic description of a superfluid as provided by the Hall-Vinen-Bekarevich-Khalatnikov equations. This leads to consistency with the definition of helicity used for classical vortices.

  17. The dipole representation of vector meson electroproduction beyond leading twist

    International Nuclear Information System (INIS)

    Besse, A.; Szymanowski, L.; Wallon, S.

    2013-01-01

    We link the recent computation beyond leading twist of the impact factor of the transition γ T ⁎ →ρ T performed in the light-cone collinear approach, to the dipole picture by expressing the hard part of the process through its Fourier transform in coordinate space. We show that in the Wandzura–Wilczek approximation the impact factor up to twist 3 factorises in the wave function of the photon combined with the distribution amplitudes of the ρ-meson and the colour dipole scattering amplitude with the t-channel gluons. We show also that beyond the Wandzura–Wilczek approximation, the hard contribution of the amplitude still exhibits the signature of the interaction of a single colour dipole with the t-channel gluons. This result allows a phenomenological approach of the helicity amplitudes of the leptoproduction of vector meson, by combining our results to a dipole/target scattering amplitude model.

  18. BK-parameter from Nf=2 twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Constantinou, M.; Dimopoulos, P.; Frezzotti, R.; INFN, Rome

    2011-01-01

    We present an unquenched N f = 2 lattice computation of the B K parameter which controls K 0 - anti K 0 oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence quarks of both the maximally twisted and the Osterwalder-Seiler variety. Suitable combinations of these two kinds of valence quarks lead to a lattice definition of the B K parameter which is both multiplicatively renormalizable and O(a) improved. Employing the non-perturbative RI-MOM scheme, in the continuum limit and at the physical value of the pion mass we get B RGI K =0.729±0.030, a number well in line with the existing quenched and unquenched determinations. (orig.)

  19. Overlap valence quarks on an twisted mass sea

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, K. [Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Drach, V.; Garcia-Ramos, E.; Herdoiza, G.; Jansen, K. [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

    2010-12-15

    We present the results of an investigation of a mixed action approach of overlap valence and maximally twisted mass sea quarks. Employing a particular matching condition on the pion mass, we analyze the continuum limit scaling of the pion decay constant and the role of chiral zero modes of the overlap operator in this process. We employ gauge field configurations generated by the European Twisted Mass Collaboration with linear lattice size L ranging from 1.3 to 1.9 fm. The continuum limit is taken at a fixed value of L=1.3 fm, employing three values of the lattice spacing and two values of the pion mass constructed from sea quarks only. (orig.)

  20. Electric currents induced by twisted light in Quantum Rings.

    Science.gov (United States)

    Quinteiro, G F; Berakdar, J

    2009-10-26

    We theoretically investigate the generation of electric currents in quantum rings resulting from the optical excitation with twisted light. Our model describes the kinetics of electrons in a two-band model of a semiconductor-based mesoscopic quantum ring coupled to light having orbital angular momentum (twisted light). We find the analytical solution, which exhibits a "circular" photon-drag effect and an induced magnetization, suggesting that this system is the circular analog of that of a bulk semiconductor excited by plane waves. For realistic values of the electric field and material parameters, the computed electric current can be as large as microA; from an applied perspective, this opens new possibilities to the optical control of the magnetization in semiconductors.

  1. Sweep-twist adaptive rotor blade : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.

    2010-02-01

    Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercial development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.

  2. Partially coherent twisted states in arrays of coupled phase oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Omel' chenko, Oleh E.; Wolfrum, Matthias [Weierstrass Institute, Mohrenstrasse 39, 10117 Berlin (Germany); Laing, Carlo R. [INMS, Massey University, Private Bag 102-904 NSMC, Auckland (New Zealand)

    2014-06-15

    We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system.

  3. Partially coherent twisted states in arrays of coupled phase oscillators

    International Nuclear Information System (INIS)

    Omel'chenko, Oleh E.; Wolfrum, Matthias; Laing, Carlo R.

    2014-01-01

    We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system

  4. Twisted tachyon condensation in closed string field theory

    International Nuclear Information System (INIS)

    Okawa, Yuji; Zwiebach, Barton

    2004-01-01

    We consider twisted tachyons on C/Z N orbifolds of bosonic closed string theory. It has been conjectured that these tachyonic instabilities correspond to decays of the orbifolds into flat space or into orbifolds with smaller deficit angles. We examine this conjecture using closed string field theory, with the string field truncated to low-level tachyons. We compute the tachyon potentials for C/Z 2 and C/Z 3 orbifolds and find critical points at depths that generate about 70% of the expected change in the deficit angle. We find that both twisted fields and untwisted modes localized near the apex of the cone acquire vacuum expectation values and contribute to the potential. (author)

  5. Stability of Medium-Bridged Twisted Amides in Aqueous Solutions

    Science.gov (United States)

    Szostak, Michal; Yao, Lei; Aubé, Jeffrey

    2012-01-01

    “Twisted” amides containing non-standard dihedral angles are typically hypersensitive to hydrolysis, a feature that has stringently limited their utility in water. We have synthesized a series of bridged lactams that contain a twisted amide linkage but which exhibit enhanced stability in aqueous environments. Many of these compounds were extracted unchanged from aqueous mixtures ranging from the strongly basic to the strongly acidic. NMR experiments showed that tricyclic lactams undergo reversible hydrolysis at extreme pH ranges, but that a number of compounds in this structure class are indefinitely stable under physiologically relevant pH conditions; one bicyclic example was additionally water-soluble. We examined the effect of structure on the reversibility of amide bond hydrolysis, which we attributed to the transannular nature of the amino acid analogs. These data suggest that medium-bridged lactams of these types should provide useful platforms for studying the behavior of twisted amides in aqueous systems. PMID:19178141

  6. Solitary Tracheobronchial Papilloma: Cytomorphology and ancillary studies with histologic correlation

    Directory of Open Access Journals (Sweden)

    Tee U Lang

    2011-01-01

    Full Text Available Solitary tracheobronchial papilloma (STBP is a rare benign tumor that primarily involves the tracheobronchial tree. Human papilloma virus (HPV infection is associated with dysplasia and a high risk of carcinoma in these lesions. The cytomorphology of STBP is not well established in the literature. Our aim is to characterize the cytomorphologic features of STBP, with histologic correlation in a series of 6 patients - 4 males and 2 females - with a mean age of 67 years (range, 53-88 years. There were 5 biopsy-proven squamous papillomas and 1 glandular papilloma. On surgical biopsy, squamous papillomas exhibited cytological atypia (4 graded mild and 1 graded moderate with focal severe dysplasia, surface erosion, and inflammation. Cytology specimens available for review included a combination of 4 fine-needle aspirations (FNAs, 2 bronchoalveolar lavages and 2 (of 3 bronchial brushings. Cytologic findings associated with squamous papillomas included atypical squamous cells and rare squamous cell resembling koilocyte in 1 bronchial brushing. Sheets of squamous cells were identified in another specimen. Several cases had a prominent background of acute inflammation, and candida was present in 1 specimen. HPV in-situ hybridization was positive in 1 case and negative in 2 cases. A p16 immunocytochemical stain performed on 1 cell block was negative. In conclusion, although STBP is a rare neoplasm, these cases may be encountered in respiratory cytology samples. FNA of papillomas yields fewer lesional cells compared to exfoliative samples. These lesions may be mistaken in cytology specimens for squamous cell carcinoma, squamous-lined cavitary lesions, an infectious (fungal process, reactive squamous metaplasia, or oral contamination.

  7. Solitary Tracheobronchial Papilloma: Cytomorphology and ancillary studies with histologic correlation.

    Science.gov (United States)

    Lang, Tee U; Khalbuss, Walid E; Monaco, Sara E; Pantanowitz, Liron

    2011-03-03

    Solitary tracheobronchial papilloma (STBP) is a rare benign tumor that primarily involves the tracheobronchial tree. Human papilloma virus (HPV) infection is associated with dysplasia and a high risk of carcinoma in these lesions. The cytomorphology of STBP is not well established in the literature. Our aim is to characterize the cytomorphologic features of STBP, with histologic correlation in a series of 6 patients - 4 males and 2 females - with a mean age of 67 years (range, 53-88 years). There were 5 biopsy-proven squamous papillomas and 1 glandular papilloma. On surgical biopsy, squamous papillomas exhibited cytological atypia (4 graded mild and 1 graded moderate with focal severe dysplasia), surface erosion, and inflammation. Cytology specimens available for review included a combination of 4 fine-needle aspirations (FNAs), 2 bronchoalveolar lavages and 2 (of 3) bronchial brushings. Cytologic findings associated with squamous papillomas included atypical squamous cells and rare squamous cell resembling koilocyte in 1 bronchial brushing. Sheets of squamous cells were identified in another specimen. Several cases had a prominent background of acute inflammation, and candida was present in 1 specimen. HPV in-situ hybridization was positive in 1 case and negative in 2 cases. A p16 immunocytochemical stain performed on 1 cell block was negative. In conclusion, although STBP is a rare neoplasm, these cases may be encountered in respiratory cytology samples. FNA of papillomas yields fewer lesional cells compared to exfoliative samples. These lesions may be mistaken in cytology specimens for squamous cell carcinoma, squamous-lined cavitary lesions, an infectious (fungal) process, reactive squamous metaplasia, or oral contamination.

  8. New twists to QCD at large-N

    International Nuclear Information System (INIS)

    Klinkhamer, F.R.

    1984-01-01

    The recently discovered reduced models of Quantum Chromodynamics in the limit of a large number (N) of colors are discussed, in particular the version that employs appropriate Z(N) twists. Some preliminary numerical data are presented, together with some new analytic results (saddle-points). This may be of some help for understanding the mechanism of confinement, which presumably is the same for all N. Also, the reduced chiral model in two dimensions is discussed

  9. Twisted bilayer blue phosphorene: A direct band gap semiconductor

    Science.gov (United States)

    Ospina, D. A.; Duque, C. A.; Correa, J. D.; Suárez Morell, Eric

    2016-09-01

    We report that two rotated layers of blue phosphorene behave as a direct band gap semiconductor. The optical spectrum shows absorption peaks in the visible region of the spectrum and in addition the energy of these peaks can be tuned with the rotational angle. These findings makes twisted bilayer blue phosphorene a strong candidate as a solar cell or photodetection device. Our results are based on ab initio calculations of several rotated blue phosphorene layers.

  10. Some new quasi-twisted ternary linear codes

    Directory of Open Access Journals (Sweden)

    Rumen Daskalov

    2015-09-01

    Full Text Available Let [n, k, d]_q code be a linear code of length n, dimension k and minimum Hamming distance d over GF(q. One of the basic and most important problems in coding theory is to construct codes with best possible minimum distances. In this paper seven quasi-twisted ternary linear codes are constructed. These codes are new and improve the best known lower bounds on the minimum distance in [6].

  11. Topological susceptibility from twisted mass fermions using spectral projectors

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Garcia-Ramos, E. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Shindler, A. [Forschungszentrum Juelich (Germany). IAS; Forschungszentrum Juelich (Germany). IKP; Forschungszentrum Juelich (Germany). JCHP; Collaboration: European Twisted Mass Collaboration

    2013-12-15

    We discuss the computation of the topological susceptibility using the method of spectral projectors and dynamical twisted mass fermions. We present our analysis concerning the O(a)- improvement of the topological susceptibility and we show numerical results for N{sub f}=2 and N{sub f}=2+1+1 flavours, performing a study of the quark mass dependence in terms of leading order chiral perturbation theory.

  12. Leading Twist GPDs and Transverse Spin Densities in a Proton

    Science.gov (United States)

    Mondal, Chandan; Maji, Tanmay; Chakrabarti, Dipankar; Zhao, Xingbo

    2018-05-01

    We present a study of both chirally even and odd generalized parton distributions in the leading twist for the quarks in a proton using the light-front wavefunctions of a quark-diquark model predicted by the holographic QCD. For transversely polarized proton, both chiral even and chiral odd GPDs contribute to the spin densities which are related to the GPDs in transverse impact parameter space. Here, we also present a study of the spin densities for transversely polarized quark and proton.

  13. Market and policy barriers for demand response providing ancillary services in U.S. markets

    Energy Technology Data Exchange (ETDEWEB)

    Cappers, Peter [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Goldman, Charles [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

    2013-03-01

    This study provides an examination of various market and policy barriers to demand response providing ancillary services in both ISO/RTO and non-ISO/RTO regions, especially at the program provider level. It is useful to classify barriers in order to create a holistic understanding and identify parties that could be responsible for their removal. This study develops a typology of barriers focusing on smaller customers that must rely on a program provider (i.e., electric investor owned utility or IOU, ARC) to create an aggregated DR resource in order to bring ancillary services to the balancing authority. The barriers were identified through examinations of regulatory structures, market environments, and product offerings; and discussions with industry stakeholders and regulators. In order to help illustrate the differences in barriers among various wholesale market designs and their constituent retail environments, four regions were chosen to use as case studies: Colorado, Texas, Wisconsin, and New Jersey.

  14. VOLTTRON-Based System for Providing Ancillary Services with Residential Building Loads

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin

    2016-07-01

    Ancillary services entail controlled modulation of building equipment to maintain a stable balance of generation and load in the power system. Ancillary services include frequency regulation and contingency reserves, whose acting time ranges from several seconds to several minutes. Many pilot studies have been implemented to use industrial loads to provide ancillary services, and some have explored services from commercial building loads or electric vehicle charging loads. Residential loads, such as space conditioning and water heating, represent a largely untapped resource for providing ancillary services. The residential building sector accounts for a significant fraction of the total electricity use in the United States. Many loads in residential buildings are flexible and could potentially be curtailed or shifted at the request of the grid. However, there are many barriers that prevent residential loads being widely used for ancillary services. One of the major technical barriers is the lack of communication capabilities between end-use devices and the grid. End-use devices need to be able to receive the automatic generation control (AGC) signal from the grid operator and supply certain types of telemetry to verify response. With the advance of consumer electronics, communication-enabled, or 'connected,' residential equipment has emerged to overcome the communication barrier. However, these end-use devices have introduced a new interoperability challenge due to the existence of numerous standards and communication protocols among different end devices. In this paper, we present a VOLTTRON-based system that overcomes these technical challenges and provides ancillary services with residential loads. VOLTTRON is an open-source control and sensing platform for building energy management, facilitating interoperability solutions for end devices. We have developed drivers to communicate and control different types of end devices through standard

  15. Provision of enhanced ancillary services from wind power plants - Examples and challenges

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit; Iov, Florin

    2016-01-01

    Emphasis in this article is on the power system impact of wind power plants capability to provide enhanced ancillary services, i.e. temporary frequency response (TFR) and power oscillation damping (POD). The main objective of the article is to analyze and justify the challenges in the use of TFR...... and POD from wind power plants (WPPs). The study is conducted with an aggregated wind power plant model which is integrated into a generic power system model, specifically designed to assess the targeted ancillary services in a relatively simple, but still relevant environment. Various case studies...... with different wind power penetration levels are considered. The study shows that WPPs can provide additional control features such as TFR and POD to enhance the stability of power systems with large share of wind power. Nevertheless, the results illustrate that the power system stability can be potentially...

  16. The State of Cell Blocks and Ancillary Testing: Past, Present, and Future.

    Science.gov (United States)

    Saqi, Anjali

    2016-12-01

    Cell blocks are an integral part of cytology, but their utility is recognized probably more now than ever before, largely owing to the significant role they play in ancillary testing, particularly molecular diagnostics. Modifications to improve the cell block method initially introduced more than a century ago have been made over the years. Though their value is acknowledged and they are widely used across laboratories, cell block preparations are not standardized and results of ancillary testing performed on them are inconsistent. This article reviews the state of cell blocks-summarizes the more common, currently available and used methods and their corresponding advantages and shortcomings, outlines the role of alternative techniques (eg, smears), and proposes methods to optimize results.

  17. The TIGRESS Integrated Plunger ancillary systems for electromagnetic transition rate studies at TRIUMF

    International Nuclear Information System (INIS)

    Voss, P.; Henderson, R.; Andreoiu, C.; Ashley, R.; Austin, R.A.E.; Ball, G.C.; Bender, P.C.; Bey, A.; Cheeseman, A.; Chester, A.; Cross, D.S.; Drake, T.E.; Garnsworthy, A.B.; Hackman, G.; Holland, R.; Ketelhut, S.; Kowalski, P.; Krücken, R.; Laffoley, A.T.; Leach, K.G.

    2014-01-01

    The TIGRESS Integrated Plunger device is a new experimental tool for nuclear structure investigations via gamma-ray spectroscopy with post-accelerated beams from the ISAC-II facility at TRIUMF. Several ancillary detection systems integral to the device's capabilities for charged-particle tagging and light-ion identification following a variety of nuclear reaction mechanisms have been constructed and characterized. In particular, a silicon PIN diode wall, an annular silicon segmented detector, and a CsI(Tl) scintillator wall have together enabled particle-gamma correlations for reaction channel selectivity and precision kinematic reconstruction in recent measurements. We highlight the construction, characteristics, and implementation of the device's ancillary detectors as they enable a rich set of electromagnetic transition rate measurements via Doppler-shift lifetime techniques and low-energy Coulomb excitation

  18. Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Fang, Jiakun

    2013-01-01

    This paper presents a simulation model of a wind power plant based on a MW-level variable speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory. Three different kinds of ancillary frequency control strategies, namely inertia...... control strategies are effective means for providing ancillary frequency control of variable speed wind turbines with full-scale back-to-back power converters....... emulation, primary frequency control and secondary frequency control, are proposed in order to improve the frequency stability of power systems. The modified IEEE 39-bus test system with a large-scale wind power penetration is chosen as the studied power system. Simulation results show that the proposed...

  19. Simulated annealing to handle energy and ancillary services joint management considering electric vehicles

    DEFF Research Database (Denmark)

    Sousa, Tiago M; Soares, Tiago; Morais, Hugo

    2016-01-01

    The massive use of distributed generation and electric vehicles will lead to a more complex management of the power system, requiring new approaches to be used in the optimal resource scheduling field. Electric vehicles with vehicle-to-grid capability can be useful for the aggregator players...... in the mitigation of renewable sources intermittency and in the ancillary services procurement. In this paper, an energy and ancillary services joint management model is proposed. A simulated annealing approach is used to solve the joint management for the following day, considering the minimization...... of the aggregator total operation costs. The case study considers a distribution network with 33-bus, 66 distributed generation and 2000 electric vehicles. The proposed simulated annealing is matched with a deterministic approach allowing an effective and efficient comparison. The simulated annealing presents...

  20. Influence of Wind Plant Ancillary Voltage Control on System Small Signal Stability

    DEFF Research Database (Denmark)

    Su, Chi; Chen, Zhe

    2012-01-01

    As a common tendency, large-scale wind farms are increasingly connected to the transmission system of modern power grids. This introduces some new challenges to the connected power systems, and the transmission system operators (TSOs) have to put some new requirements as part of the grid codes...... on the integration of wind farms. One common requirement to wind farms is the function of system voltage control which can be implemented in the grid-side convertor controller of a variable speed wind turbine. This ancillary voltage control provided by wind farms could have some influence on the system small signal...... stability. This paper implements an ancillary voltage control strategy on a direct-drive-full-convertor-based wind farm and studies its influence on the damping ratio values of the dominant oscillation mode within the connected power system. All the calculations and simulations are conducted in DIg...

  1. Twisted boundary states and representation of generalized fusion algebra

    International Nuclear Information System (INIS)

    Ishikawa, Hiroshi; Tani, Taro

    2006-01-01

    The mutual consistency of boundary conditions twisted by an automorphism group G of the chiral algebra is studied for general modular invariants of rational conformal field theories. We show that a consistent set of twisted boundary states associated with any modular invariant realizes a non-negative integer matrix representation (NIM-rep) of the generalized fusion algebra, an extension of the fusion algebra by representations of the twisted chiral algebra associated with the automorphism group G. We check this result for several concrete cases. In particular, we find that two NIM-reps of the fusion algebra for su(3) k (k=3,5) are organized into a NIM-rep of the generalized fusion algebra for the charge-conjugation automorphism of su(3) k . We point out that the generalized fusion algebra is non-commutative if G is non-Abelian and provide some examples for G-bar S 3 . Finally, we give an argument that the graph fusion algebra associated with simple current extensions coincides with the generalized fusion algebra for the extended chiral algebra, and thereby explain that the graph fusion algebra contains the fusion algebra of the extended theory as a subalgebra

  2. Unwinding motion of a twisted active region filament

    Energy Technology Data Exchange (ETDEWEB)

    Yan, X. L.; Xue, Z. K.; Kong, D. F. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Liu, J. H. [Department of Physics, Shijiazhuang University, Shijiazhuang 050035 (China); Xu, C. L. [Yunnan Normal University, Kunming 650092 (China)

    2014-12-10

    To better understand the structures of active region filaments and the eruption process, we study an active region filament eruption in active region NOAA 11082 in detail on 2010 June 22. Before the filament eruption, the opposite unidirectional material flows appeared in succession along the spine of the filament. The rising of the filament triggered two B-class flares at the upper part of the filament. As the bright material was injected into the filament from the sites of the flares, the filament exhibited a rapid uplift accompanying the counterclockwise rotation of the filament body. From the expansion of the filament, we can see that the filament consisted of twisted magnetic field lines. The total twist of the filament is at least 5π obtained by using a time slice method. According to the morphology change during the filament eruption, it is found that the active region filament was a twisted flux rope and its unwinding motion was like a solar tornado. We also find that there was a continuous magnetic helicity injection before and during the filament eruption. It is confirmed that magnetic helicity can be transferred from the photosphere to the filament. Using the extrapolated potential fields, the average decay index of the background magnetic fields over the filament is 0.91. Consequently, these findings imply that the mechanism of solar filament eruption could be due to the kink instability and magnetic helicity accumulation.

  3. Microwave modulation characteristics of twisted liquid crystals with chiral dopant

    Directory of Open Access Journals (Sweden)

    Rui Yuan

    2017-01-01

    Full Text Available Adding a chiral dopant in twisted nematic (TN liquid crystal cell can stabilize the orientation of liquid crystal molecules, particularly in high TN (HTN or super TN (STN liquid crystal cells. The difference in pitches in liquid crystal is induced by the chiral dopant, and these different pitches affect the orientation of liquid crystal director under an external applied voltage and influence the characteristics of microwave modulation. To illustrate this point, the microwave phase shift per unit length (MPSL versus voltage is calculated on the basis of the elastic theory of liquid crystal and the finite-difference iterative method. Enhancing the pitch induced by the chiral dopant in liquid crystal increases the MPSLs, but the stability of the twisted structures is decreased. Thus, appropriate pitches of 100d, 4d, and 2d can be applied in TN, HTN, and STN cells with cell gap d to enhance the characteristics of microwave modulation and stabilize the structures in twisted cell. This method can improve the characteristics of liquid crystal microwave modulators such that the operating voltage and the size of such phase shifters can be decreased.

  4. Twist operator correlation functions in O(n) loop models

    International Nuclear Information System (INIS)

    Simmons, Jacob J H; Cardy, John

    2009-01-01

    Using conformal field theoretic methods we calculate correlation functions of geometric observables in the loop representation of the O(n) model at the critical point. We focus on correlation functions containing twist operators, combining these with anchored loops, boundaries with SLE processes and with double SLE processes. We focus further upon n = 0, representing self-avoiding loops, which corresponds to a logarithmic conformal field theory (LCFT) with c = 0. In this limit the twist operator plays the role of a 0-weight indicator operator, which we verify by comparison with known examples. Using the additional conditions imposed by the twist operator null states, we derive a new explicit result for the probabilities that an SLE 8/3 winds in various ways about two points in the upper half-plane, e.g. that the SLE passes to the left of both points. The collection of c = 0 logarithmic CFT operators that we use deriving the winding probabilities is novel, highlighting a potential incompatibility caused by the presence of two distinct logarithmic partners to the stress tensor within the theory. We argue that both partners do appear in the theory, one in the bulk and one on the boundary and that the incompatibility is resolved by restrictive bulk-boundary fusion rules

  5. Twisted Bilayer Graphene. Interlayer configuration and magnetotransport signatures

    Energy Technology Data Exchange (ETDEWEB)

    Rode, Johannes C.; Smirnov, Dmitri; Belke, Christopher; Schmidt, Hennrik; Haug, Rolf J. [Institut fuer Festkoerperphysik, Hannover (Germany)

    2017-11-15

    Twisted Bilayer Graphene may be viewed as very first representative of the now booming class of artificially layered 2D materials. Consisting of two sheets from the same structure and atomic composition, its decisive degree of freedom lies in the rotation between crystallographic axes in the individual graphene monolayers. Geometrical consideration finds angle-dependent Moire patterns as well as commensurate superlattices of opposite sublattice exchange symmetry. Beyond the approach of rigidly interposed lattices, this review takes focus on the evolving topic of lattice corrugation and distortion in response to spatially varying lattice registry. The experimental approach to twisted bilayers requires a basic control over preparation techniques; important methods are summarized and extended on in the case of bilayers folded from monolayer graphene via AFM nanomachining. Central morphological parameters to the twisted bilayer, rotational mismatch and interlayer separation are studied in a broader base of samples. Finally, experimental evidence for a number of theoretically predicted, controversial electronic scenarios are reviewed; magnetotransport signatures are discussed in terms of Fermi velocity, van Hove singularities and Berry phase and assessed with respect to the underlying experimental conditions, thereby referring back to the initially considered variations in relaxed lattice structure. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Wrinkles, loops, and topological defects in twisted ribbons

    Science.gov (United States)

    Chopin, Julien

    Nature abounds with elastic ribbon like shapes including double-stranded semiflexible polymers, graphene and metal oxide nanoribbons which are examples of elongated elastic structures with a strongly anisotropic cross-section. Due to this specific geometry, it is far from trivial to anticipate if a ribbon should be considered as a flat flexible filament or a narrow thin plate. We thus perform an experiment in which a thin elastic ribbon is loaded using a twisting and traction device coupled with a micro X-ray computed tomography machine allowing a full 3D shape reconstruction. A wealth of morphological behaviors can be observed including wrinkled helicoids, curled and looped configurations, and faceted ribbons. In this talk, I will show that most morphologies can be understood using a far-from-threshold approach and simple scaling arguments. Further, we find that the various shapes can be organized in a phase diagram using the twist, the tension, and the geometry of the ribbon as control parameters. Finally, I will discuss the spontaneous formation of topological defects with negatively-signed Gaussian charge at large twist and small but finite stretch.

  7. The SU(∞) twisted gradient flow running coupling

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, Margarita García [Instituto de Física Teórica UAM-CSIC,Nicolás Cabrera 13-15, E-28049-Madrid (Spain); González-Arroyo, Antonio [Instituto de Física Teórica UAM-CSIC,Nicolás Cabrera 13-15, E-28049-Madrid (Spain); Departamento de Física Teórica, C-15, Universidad Autónoma de Madrid,E-28049-Madrid (Spain); Keegan, Liam [PH-TH, CERN,CH-1211 Geneva 23 (Switzerland); Okawa, Masanori [Graduate School of Science, Hiroshima University,Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

    2015-01-09

    We measure the running of the SU(∞) ’t Hooft coupling by performing a step scaling analysis of the Twisted Eguchi-Kawai (TEK) model, the SU(N) gauge theory on a single site lattice with twisted boundary conditions. The computation relies on the conjecture that finite volume effects for SU(N) gauge theories defined on a 4-dimensional twisted torus are controlled by an effective size parameter l-tilde=l√N, with l the torus period. We set the scale for the running coupling in terms of l-tilde and use the gradient flow to define a renormalized ’t Hooft coupling λ(l-tilde). In the TEK model, this idea allows the determination of the running of the coupling through a step scaling procedure that uses the rank of the group as a size parameter. The continuum renormalized coupling constant is extracted in the zero lattice spacing limit, which in the TEK model corresponds to the large N limit taken at fixed value of λ(l-tilde). The coupling constant is thus expected to coincide with that of the ordinary pure gauge theory at N=∞. The idea is shown to work and permits us to follow the evolution of the coupling over a wide range of scales. At weak coupling we find a remarkable agreement with the perturbative two-loop formula for the running coupling.

  8. The $SU(\\infty)$ twisted gradient flow running coupling

    CERN Document Server

    Pérez, Margarita García; Keegan, Liam; Okawa, Masanori

    2015-01-01

    We measure the running of the $SU(\\infty)$ 't Hooft coupling by performing a step scaling analysis of the Twisted Eguchi-Kawai (TEK) model, the SU($N$) gauge theory on a single site lattice with twisted boundary conditions. The computation relies on the conjecture that finite volume effects for SU(N) gauge theories defined on a 4-dimensional twisted torus are controlled by an effective size parameter $\\tilde l = l \\sqrt{N}$, with $l$ the torus period. We set the scale for the running coupling in terms of $\\tilde l$ and use the gradient flow to define a renormalized 't Hooft coupling $\\lambda(\\tilde l)$. In the TEK model, this idea allows the determination of the running of the coupling through a step scaling procedure that uses the rank of the group as a size parameter. The continuum renormalized coupling constant is extracted in the zero lattice spacing limit, which in the TEK model corresponds to the large $N$ limit taken at fixed value of $\\lambda(\\tilde l)$. The coupling constant is thus expected to coinc...

  9. Twist effects in quantum vortices and phase defects

    Science.gov (United States)

    Zuccher, Simone; Ricca, Renzo L.

    2018-02-01

    In this paper we show that twist, defined in terms of rotation of the phase associated with quantum vortices and other physical defects effectively deprived of internal structure, is a property that has observable effects in terms of induced axial flow. For this we consider quantum vortices governed by the Gross-Pitaevskii equation (GPE) and perform a number of test cases to investigate and compare the effects of twist in two different contexts: (i) when this is artificially superimposed on an initially untwisted vortex ring; (ii) when it is naturally produced on the ring by the simultaneous presence of a central straight vortex. In the first case large amplitude perturbations quickly develop, generated by the unnatural setting of the initial condition that is not an analytical solution of the GPE. In the second case much milder perturbations emerge, signature of a genuine physical process. This scenario is confirmed by other test cases performed at higher twist values. Since the second setting corresponds to essential linking, these results provide new evidence of the influence of topology on physics.

  10. Vertical Keiretsu and International Market Entry: The Case of the Japanese Automobile Ancillary Industry

    OpenAIRE

    Kunal Banerji; Rakesh B Sambharya

    1996-01-01

    This study investigated whether small Japanese automobile ancillary firms followed the major Japanese automakers in setting up production facilities in the United States. Based on Dunning's eclectic theory of foreign direct investment and resource dependence theory, hypotheses were generated to explain the determinants of foreign investment of Japanese suppliers. It was hypothesized that mutual dependencies between the major Japanese automobile firms and their suppliers, firm-specific ownersh...

  11. Exploring the ancillary benefits of the Kyoto Protocol for air pollution in Europe

    International Nuclear Information System (INIS)

    Vuuren, D.P. van; Cofala, J.; Eerens, H.E.; Oostenrijk, R.; Heyes, C.; Klimont, Z.; Elzen, M.G.J. den; Amann, M.

    2006-01-01

    An integrated approach to climate change and regional air pollution can harvest considerable ancillary benefits in terms of environmental impacts and costs. This is because both problems are caused to a large extent by the same activity (fossil fuel combustion). Substantial ancillary benefits were found for regional air pollution (SO 2 , NO x , VOC and particulate matter) of implementing the Kyoto Protocol (intended to control greenhouse gas emissions) in Europe. For instance, while three different scenarios on Kyoto implementation were found to reduce European CO 2 emissions by 4-7%, they also reduced European emissions of SO 2 by 5-14% compared with a no Kyoto policies case. The magnitude of ancillary benefits depends on how flexible mechanisms and surplus emission allowances are used in meeting the Kyoto targets. The total cost savings for implementing current policies for regional air pollution of the Kyoto Protocol are of an order of 2.5-7 billion Euro. In all cases, this is in the order of half the costs of the climate policy (4-12 billion Euro). Using flexible mechanisms reduces emissions of air pollutants for Europe as a whole even further than domestic implementation (e.g. 10-14% versus 5% for SO 2 emissions), but the reductions are shifted from Western Europe to Central and Eastern Europe and Russia. The use of surplus emission allowances to achieve the Kyoto targets decreases the ancillary benefits, in particular for the latter group of countries (e.g. unprotected area against acidification increases from 1.3 to 1.7 million ha)

  12. Enhancement of turbulent flow heat transfer in a tube with modified twisted tapes

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Y.G.; Zhao, C.H.; Song, C.F. [College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan (China)

    2012-12-15

    Numerical simulations were performed to study the fluid flow and heat transfer in a tube with staggered twisted tapes with central holes. In the range of Reynolds numbers between 6000 and 28 000, the modified twisted tapes increased the Nusselt number by 76.2 {proportional_to} 149.7 % and the friction factor by 380.2 {proportional_to} 443.8 % compared to the smooth tube. Compared to the typical twisted tapes, the modified twisted tapes produced an acceleration flow through the triangle regions leading to the enhancement of heat transfer, and the holes in the modified tapes reduced the severe pressure loss. It was found that the modified twisted tapes decreased the friction factor by 8.0 {proportional_to} 16.1 % and enhanced the heat transfer by 34.1 {proportional_to} 46.8 % in comparison with the typical tapes. These results indicated that the performance ratio values of the tube with modified twisted tapes were higher than 1.0 in the range of Reynolds numbers studied. The computed performance ratios of the tube with modified twisted tapes were much higher than those of the tube with typical twisted tapes. This means that the integrated performance of the tube with staggered twisted tapes with central holes is superior to that of the tube with typical twisted tapes. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Twist1 suppresses senescence programs and thereby accelerates and maintains mutant Kras-induced lung tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Phuoc T Tran

    Full Text Available KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer mouse model and in human lung tumors that the inhibition of Twist1 restores a senescence program inducing the loss of a neoplastic phenotype. The Twist1 gene encodes for a transcription factor that is essential during embryogenesis. Twist1 has been suggested to play an important role during tumor progression. However, there is no in vivo evidence that Twist1 plays a role in autochthonous tumorigenesis. Through two novel transgenic mouse models, we show that Twist1 cooperates with Kras(G12D to markedly accelerate lung tumorigenesis by abrogating cellular senescence programs and promoting the progression from benign adenomas to adenocarcinomas. Moreover, the suppression of Twist1 to physiological levels is sufficient to cause Kras mutant lung tumors to undergo senescence and lose their neoplastic features. Finally, we analyzed more than 500 human tumors to demonstrate that TWIST1 is frequently overexpressed in primary human lung tumors. The suppression of TWIST1 in human lung cancer cells also induced cellular senescence. Hence, TWIST1 is a critical regulator of cellular senescence programs, and the suppression of TWIST1 in human tumors may be an effective example of pro-senescence therapy.

  14. Smart microgrid hierarchical frequency control ancillary service provision based on virtual inertia concept: An integrated demand response and droop controlled distributed generation framework

    International Nuclear Information System (INIS)

    Rezaei, Navid; Kalantar, Mohsen

    2015-01-01

    Highlights: • Detailed formulation of the microgrid static and dynamic securities based on droop control and virtual inertia concepts. • Constructing a novel objective function using frequency excursion and rate of change of frequency profiles. • Ensuring the microgrid security subject to the microgrid economic and environmental policies. • Coordinated management of demand response and droop controlled distributed generation resources. • Precise scheduling of day-ahead hierarchical frequency control ancillary services using a scenario based stochastic programming. - Abstract: Low inertia stack, high penetration levels of renewable energy source and great ratio of power deviations in a small power delivery system put microgrid frequency at risk of instability. On the basis of the close coupling between the microgrid frequency and system security requirements, procurement of adequate ancillary services from cost-effective and environmental friendly resources is a great challenge requests an efficient energy management system. Motivated by this need, this paper presents a novel energy management system that is aimed to coordinately manage the demand response and distributed generation resources. The proposed approach is carried out by constructing a hierarchical frequency control structure in which the frequency dependent control functions of the microgrid components are modeled comprehensively. On the basis of the derived modeling, both the static and dynamic frequency securities of an islanded microgrid are provided in primary and secondary control levels. Besides, to cope with the low inertia stack of islanded microgrids, novel virtual inertia concept is devised based on the precise modeling of droop controlled distributed generation resources. The proposed approach is applied to typical test microgrid. Energy and hierarchical reserve resource are scheduled precisely using a scenario-based stochastic programming methodology. Moreover, analyzing the

  15. Potential of vehicle-to-grid ancillary services considering the uncertainties in plug-in electric vehicle availability and service/localization limitations in distribution grids

    International Nuclear Information System (INIS)

    Sarabi, Siyamak; Davigny, Arnaud; Courtecuisse, Vincent; Riffonneau, Yann; Robyns, Benoît

    2016-01-01

    Highlights: • The availability uncertainty of PEVs are modelled using Gaussian mixture model. • Interdependency of stochastic variables are modelled using copula function. • V2G bidding capacity is calculated using Free Pattern search optimization method. • Localization limitation is considered for V2G service potential assessment. • Competitive services for fleet of V2G-enabled PEVs are identified using fuzzy sets. - Abstract: The aim of the paper is to propose an approach for statistical assessment of the potential of plug-in electric vehicles (PEV) for vehicle-to-grid (V2G) ancillary services, where it focuses on PEVs doing daily home-work commuting. In this approach, the possible ancillary services (A/S) for each PEV fleet in terms of its available V2G power (AVP) and flexible intervals are identified. The flexible interval is calculated using a powerful stochastic global optimization technique so-called “Free Pattern Search” (FPS). A probabilistic method is also proposed to quantify the impacts of PEV’s availability uncertainty using the Gaussian mixture model (GMM), and interdependency of stochastic variables on AVP of each fleet thanks to a multivariate modeling with Copula function. Each fleet is analyzed based on its aggregated PEV numbers at different level of distribution grid, in order to satisfy the ancillary services localization limitation. A case study using the proposed approach evaluates the real potential in Niort, a city in west of France. In fact, by using the proposed approach an aggregator can analyze the V2G potential of PEVs under its contract.

  16. The impact of communication barriers on diagnostic confidence and ancillary testing in the emergency department.

    Science.gov (United States)

    Garra, Gregory; Albino, Hiram; Chapman, Heather; Singer, Adam J; Thode, Henry C

    2010-06-01

    Communication barriers (CBs) compromise the diagnostic power of the medical interview and may result in increased reliance on diagnostic tests or incorrect test ordering. The prevalence and degree to which these barriers affect diagnosis, testing, and treatment are unknown. To quantify and characterize CBs encountered in the Emergency Department (ED), and assess the effect of CBs on initial diagnosis and perceived reliance on ancillary testing. This was a prospective survey completed by emergency physicians after initial adult patient encounters. CB severity, diagnostic confidence, and reliance on ancillary testing were quantified on a 100-mm Visual Analog Scale (VAS) from least (0) to most (100). Data were collected on 417 ED patient encounters. CBs were reported in 46%; with a mean severity of 50 mm on a 100-mm VAS with endpoints of "perfect communication and "no communication." Language was the most commonly reported form of CB (28%). More than one CB was identified in 6%. The 100-mm VAS rating of diagnostic confidence was lower in patients with perceived CBs (64 mm) vs. those without CBs (80 mm), p Communication barriers in our ED setting were common, and resulted in lower diagnostic confidence and increased perception that ancillary tests are needed to narrow the diagnosis. Copyright 2010 Elsevier Inc. All rights reserved.

  17. Application of microgrids in providing ancillary services to the utility grid

    International Nuclear Information System (INIS)

    Majzoobi, Alireza; Khodaei, Amin

    2017-01-01

    A microgrid optimal scheduling model is developed in this paper to demonstrate microgrid's capability in offering ancillary services to the utility grid. The application of localized ancillary services is of significant importance to grid operators as the growing proliferation of distributed renewable energy resources, mainly solar generation, is causing major technical challenges in supply-load balance. The proposed microgrid optimal scheduling model coordinates the microgrid net load with the aggregated consumers/prosumers net load in its connected distribution feeder to capture both inter-hour and intra-hour net load variations. In particular, net load variations for three various time resolutions are considered, including hourly ramping, 10-min based load following, and 1-min based frequency regulation. Numerical simulations on a test distribution feeder with one microgrid and several consumers/prosumers indicate the effectiveness of the proposed model and the viability of the microgrid application in supporting grid operation. - Highlights: • Microgrid optimal scheduling for providing ancillary services to the utility grid. • Local management and mitigation of distribution net load variations. • Offering various support services: ramping, load following, frequency regulation. • Proven effectiveness and accuracy in capturing net load variations.

  18. Exclusive processes beyond leading twist: {gamma}*T {yields} {rho}T impact factor with twist three accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Szymanowski, Lech [Soltan Institute for Nuclear Studies, Hoza 69, 00691, Warsaw (Poland); Anikin, Igor V. [Joint Institute for Nuclear Research - JINR, Joliot-Curie st., 6, Moskovskaya obl., 141980, Dubna (Russian Federation); Ivanov, Dmitry Yu [Sobolev Institute of Mathematics, Acad. Koptyug pr., 4, 630090 Novosibirsk (Russian Federation); Pire, Bernard [Centre de Physique Theorique - CPHT, UMR 7644, Ecole Polytechnique, Bat. 6, RDC, F91128 Palaiseau Cedex (France); Wallon, Samuel [Laboratoire de Physique Theorique d' Orsay - LPT, Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France)

    2010-07-01

    We describe a consistent approach to factorization of scattering amplitudes for exclusive processes beyond the leading twist approximation. The method is based on the Taylor expansion of the scattering amplitude in the momentum space around the dominant light-cone direction and thus naturally introduces an appropriate set of non-perturbative correlators which encode effects not only of the lowest but also of the higher Fock states of the produced particle. The reduction of original set of correlators to a set of independent ones is achieved with the help of equations of motion and invariance of the scattering amplitude under rotation on the light-cone. As a concrete application, we compute the expressions of the impact factor for the transition of virtual photon to transversally polarised {rho}-meson up to the twist 3 accuracy. (Phys.Lett.B682:413-418,2010 and Nucl.Phys.B828:1-68,2010.). (authors)

  19. Topological twist in four dimensions, R-duality and hyperinstantons

    International Nuclear Information System (INIS)

    Anselmi, D.; Fre, P.

    1993-01-01

    In this paper we continue the programme of topologically twisting N=2 theories in D=4, focusing on the coupling of vector multiplets to N=2 supergravity. We show that in the minimal case, namely when the special gometry prepotential F(X) is a quadratic polynomial, the theory has a so far unknown on-shell U(1) symmetry, that we name R-duality. R-duality is a generalization of the chiral-dual on-shell symmetry of N=2 pure supergravity and of the R-symmetry of N=2 super Yang-Mills theory. Thanks to this, the theory can be topologically twisted and topologically shifted, precisely as pure N=2 supergravity, to yield a natural coupling of topological gravity to topological Yang-Mills theory. The gauge-fixing condition that emerges from the twisting is the self-duality condition on the gauge field strength and on the spin connection. Hence our theory reduces to intersection theory in the moduli-space of gauge instantons living in gravitational instanton backgrounds. We remark that, for deep properties of the parent N=2 theory, the topological Yang-Mills theory we obtain by taking the flat space limit of our gravity-coupled lagrangian is different from the Donaldson theory constructed by Witten. Whether this difference is substantial and what its geometrical implications may be is yet to be seen. We also discuss the topological twist of the hypermultiplets leading to topological quaternionic sigma-models. The instantons of these models, named by us hyperinstantons, correspond to a notion of triholomorphic mappings discussed in the paper. In all cases the new ghost number is the sum of the old ghost number plus the R-duality charge. The observables described by the theory are briefly discussed. In conclusion, the topological twist of the complete N=2 theory defines intersection theory in the moduli-space of gauge instantons plus gravitational instantons plus hyperinstantons. This is possibly a new subject for further mathematical investigation. (orig.)

  20. Integral Twist Actuation of Helicopter Rotor Blades for Vibration Reduction

    Science.gov (United States)

    Shin, SangJoon; Cesnik, Carlos E. S.

    2001-01-01

    Active integral twist control for vibration reduction of helicopter rotors during forward flight is investigated. The twist deformation is obtained using embedded anisotropic piezocomposite actuators. An analytical framework is developed to examine integrally-twisted blades and their aeroelastic response during different flight conditions: frequency domain analysis for hover, and time domain analysis for forward flight. Both stem from the same three-dimensional electroelastic beam formulation with geometrical-exactness, and axe coupled with a finite-state dynamic inflow aerodynamics model. A prototype Active Twist Rotor blade was designed with this framework using Active Fiber Composites as the actuator. The ATR prototype blade was successfully tested under non-rotating conditions. Hover testing was conducted to evaluate structural integrity and dynamic response. In both conditions, a very good correlation was obtained against the analysis. Finally, a four-bladed ATR system is built and tested to demonstrate its concept in forward flight. This experiment was conducted at NASA Langley Tansonic Dynamics Tunnel and represents the first-of-a-kind Mach-scaled fully-active-twist rotor system to undergo forward flight test. In parallel, the impact upon the fixed- and rotating-system loads is estimated by the analysis. While discrepancies are found in the amplitude of the loads under actuation, the predicted trend of load variation with respect to its control phase correlates well. It was also shown, both experimentally and numerically, that the ATR blade design has the potential for hub vibratory load reduction of up to 90% using individual blade control actuation. Using the numerical framework, system identification is performed to estimate the harmonic transfer functions. The linear time-periodic system can be represented by a linear time-invariant system under the three modes of blade actuation: collective, longitudinal cyclic, and lateral cyclic. A vibration

  1. Analysis of the Impact of Wind Power Participating in Both Energy and Ancillary Services Markets – The Danish Case

    DEFF Research Database (Denmark)

    Soares, Tiago; Morais, Hugo; Pinson, Pierre

    2014-01-01

    The impact of a high penetration of wind power generation in power systems motivates need for an assessment of its inte raction with electricity markets. With the continuous evolution of wind turbines technology, wind farms have today the ability to provide certain ancillary services...... with appropriate levels of security and reliability . The participation of wind f arms i n ancillary service market s ought to rely on market designs and offering strategies that satisfy power system needs, as well as their operating characteristics . Here we evaluate the system impact of different offering...... strategies that wind farms employ on ene rgy and ancillary service market. A lready proposed Proportional Wind Reserve Strategy (PWRS) and a Continuo us Wind Reserve Strategy (CWRS) are used to determine the amount of available power for ancillary services. A case study based on real and recent dat...

  2. CO{sub 2} mitigation costs and ancillary benefits in the Nordic countries, the UK and Ireland: A survey

    Energy Technology Data Exchange (ETDEWEB)

    Kverndokk, Snorre; Rosendahl, Knut Einar

    2000-07-01

    This paper provides a survey of top-down modelling studies on mitigation costs and ancillary benefits in the Nordic countries, the UK and Ireland. Special emphasis is put on results concerning revenue recycling, double dividend, distributional effects and ancillary benefits. According to the papers surveyed, modest emissions restrictions as those given by the Kyoto Protocol, can be met without substantial costs for the countries studied. (Author)

  3. Effect of Twisting and Stretching on Magneto Resistance and Spin Filtration in CNTs

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singh

    2017-08-01

    Full Text Available Spin-dependent quantum transport properties in twisted carbon nanotube and stretched carbon nanotube are calculated using density functional theory (DFT and non-equilibrium green’s function (NEGF formulation. Twisting and stretching have no effect on spin transport in CNTs at low bias voltages. However, at high bias voltages the effects are significant. Stretching restricts any spin-up current in antiparallel configuration (APC, which results in higher magneto resistance (MR. Twisting allows spin-up current almost equivalent to the pristine CNT case, resulting in lower MR. High spin filtration is observed in PC and APC for pristine, stretched and twisted structures at all applied voltages. In APC, at low voltages spin filtration in stretched CNT is higher than in pristine and twisted ones, with pristine giving a higher spin filtration than twisted CNT.

  4. Twisted entire cyclic cohomology, J-L-O cocycles and equivariant spectral triples

    International Nuclear Information System (INIS)

    Goswami, D.

    2002-07-01

    We study the 'quantized calculus' corresponding to the algebraic ideas related to 'twisted cyclic cohomology'. With very similar definitions and techniques, we define and study 'twisted entire cyclic cohomology' and the 'twisted Chern character' associated with an appropriate operator theoretic data called 'twisted spectral data', which consists of a spectral triple in the conventional sense of noncommutative geometry and an additional positive operator having some specified properties. Furthermore, it is shown that given a spectral triple (in the conventional sense) which is equivariant under the action of a compact matrix pseudogroup, it is possible to obtain a canonical twisted spectral data and hence the corresponding (twisted) Chern character, which will be invariant under the action of the pseudogroup, in contrast to the fact that the Chern character coming from the conventional noncommutative geometry need not be invariant under the above action. (author)

  5. PERFORMANCE CHARACTERISTICS OF PARABOLIC SOLAR COLLECTOR WATER HEATER SYSTEM FITTED WITH NAIL TWISTED TAPES ABSORBER

    Directory of Open Access Journals (Sweden)

    K. SYED JAFAR

    2017-03-01

    Full Text Available In this paper, the experimental heat transfer, friction loss and thermal performance data for water flowing through the absorber tube fitted with two different twisted tape configurations in parabolic trough collector (PTC are presented. In the present work, a relative experimental study is carried out to investigate the performance of a PTC influenced by heat transfer through fluidabsorber wall mixing mechanism. The major findings of this experiment show that heat transport enhancement in the nail twisted tape collector perform significantly better than plain twisted tapes and also show that the smallest twisted tape ratio enhances the system performance remarkably maximizing the collector efficiency. The results suggest that the twisted tape and nail twisted tape would be a better option for high thermal energy collection in laminar region of the PTC system.

  6. Ancillary Services 4.0: A Top-To-Bottom Control-Based Approach for Solving Ancillary Services Problems in Smart Grids

    DEFF Research Database (Denmark)

    De Zotti, Giulia; Pourmousavi, S. Ali; Madsen, Henrik

    2018-01-01

    of AS are not able to benefit from the flexible energy resources. They also cannot cope with the new level of stochasticity, non-linearity, and dynamics of generation and flexibility. To overcome such issues and exploit the potential of flexibility resources, a new strategy is required. In this paper......Power systems are experiencing a large amount of renewable generation with highly stochastic and partly unpredictable characteristics. This change in energy production implies significant consequences related to the provision of ancillary services (AS). Current markets dedicated to the provision......, by capitalizing on flexibility resources' potential, AS 4.0 approach is proposed, which offers a comprehensive solution for the AS provision in the smart grid era....

  7. Performance improvement of small-scale rotors by passive blade twist control

    OpenAIRE

    Lv, Peng; Prothin, Sebastien; Mohd Zawawi, Fazila; Bénard, Emmanuel; Morlier, Joseph; Moschetta, Jean-Marc

    2015-01-01

    A passive twist control is proposed as an adaptive way to maximize the overall efficiency of the small-scale rotor blade for multifunctional aircrafts. Incorporated into a database of airfoil characteristics, Blade Element Momentum Theory is implemented to obtain the blade optimum twist rates for hover and forward flight. In order to realize the required torsion of blade between hover and forward flight, glass/epoxy laminate blade is proposed based on Centrifugal Force Induced Twist concept. ...

  8. Higher-Twist Distribution Amplitudes of the K Meson in QCD

    CERN Document Server

    Ball, P; Lenz, A; Ball, Patricia

    2006-01-01

    We present a systematic study of twist-3 and twist-4 light-cone distribution amplitudes of the K meson in QCD. The structure of SU(3)-breaking corrections is studied in detail. Non-perturbative input parameters are estimated from QCD sum rules and renormalons. As a by-product, we give a complete reanalysis of the twist-3 and -4 parameters of the pi-meson distribution amplitudes; some of the results differ from those usually quoted in the literature.

  9. Analysis of a Caenorhabditis elegans Twist homolog identifies conserved and divergent aspects of mesodermal patterning

    OpenAIRE

    Harfe, Brian D.; Gomes, Ana Vaz; Kenyon, Cynthia; Liu, Jun; Krause, Michael; Fire, Andrew

    1998-01-01

    Mesodermal development is a multistep process in which cells become increasingly specialized to form specific tissue types. In Drosophila and mammals, proper segregation and patterning of the mesoderm involves the bHLH factor Twist. We investigated the activity of a Twist-related factor, CeTwist, during Caenorhabditis elegans mesoderm development. Embryonic mesoderm in C. elegans derives from a number of distinct founder cells that are specified during the early lineages; in contrast, a singl...

  10. Measurement of curvature and twist of a deformed object using digital holography

    International Nuclear Information System (INIS)

    Chen Wen; Quan Chenggen; Cho Jui Tay

    2008-01-01

    Measurement of curvature and twist is an important aspect in the study of object deformation. In recent years, several methods have been proposed to determine curvature and twist of a deformed object using digital shearography. Here we propose a novel method to determine the curvature and twist of a deformed object using digital holography and a complex phasor. A sine/cosine transformation method and two-dimensional short time Fourier transform are proposed subsequently to process the wrapped phase maps. It is shown that high-quality phase maps corresponding to curvature and twist can be obtained. An experiment is conducted to demonstrate the validity of the proposed method

  11. A method to estimate the necessary twist pitch in multi-filamentary superconductors

    International Nuclear Information System (INIS)

    Lindau, S; Magnusson, N; Taxt, H

    2014-01-01

    Twisting of multi-filamentary superconductors is an important step in the development of wires with AC losses at an acceptable level for AC applications. The necessary twist pitch depends on wire architecture, critical current density, matrix material, and external factors such as temperature, frequency and applied magnetic field. The development of an AC optimized MgB 2 superconductor would be facilitated by a fast method to set the requirements for the twist pitch. A problem often encountered when comparing wires with different twist pitches is the degradation in critical current occurring at small twist pitches due to mechanical deformation. In this work we propose to use a non-twisted conductor to estimate the influence of twisting on the AC losses. A long superconductor is cut into smaller lengths, each simulating one third of the twist pitch, and the AC losses due to applied magnetic fields are compared between samples of different lengths. With this method, the effect of reducing the size of the loop of the coupling currents is studied without changing the superconducting parameters. AC loss measurement results are presented for a round titanium matrix MgB 2 wire with simulated twist pitches between 9 mm and 87 mm.

  12. Dynamical twisted mass fermions with light quarks. Simulation and analysis details

    International Nuclear Information System (INIS)

    Boucaud, P.; Dimopoulos, P.; Farchioni, F.

    2008-03-01

    In a recent paper (2007) we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae. (orig.)

  13. Dynamical twisted mass fermions with light quarks. Simulation and analysis details

    Energy Technology Data Exchange (ETDEWEB)

    Boucaud, P. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P. [Rome-2 Univ. (Italy). Dipt. di Fisica; Farchioni, F. [Muenster Univ. (DE). Inst. fuer Theoretische Physik] (and others)

    2008-03-15

    In a recent paper (2007) we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae. (orig.)

  14. Compliance with technical codes becomes obligatory for receipt of feed-in tariff and ancillary services bonus for wind power plants in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Boemer, Jens. C. [Ecofys Germany GmbH, Berlin (Germany). Power Systems and Markets Group; Delft Univ. of Technology (Netherlands). Electrical Power Systems Group; Burges, Karsten [Ecofys Germany GmbH, Berlin (Germany). Power Systems and Markets Group; Kumm, Thomas [VDE, Network Technology and Operation Forum (FNN), Berlin (Germany); Poeller, Markus [DIgSILENT GmbH, Gomaringen (Germany)

    2009-07-01

    The German government aims at a share of electricity generation based on renewable sources (RES-E) of more than 30% by 2020. A major part of this share will be reached by the use of wind power plants (WPP). Therefore, when amending the Renewable Energy Sources Act (EEG) in June 2008, the German government acknowledged the importance of enhanced technical requirements for WPP and announced the development of a respective technical ordinance. For all WPP that go into operation after June 2010, full grid code-compliance becomes a precondition for privileged network access, receipt of feed-in tariff, and extra payments (''ancillary services bonus''). The basis for the technical requirements in the EEG has been laid down by Medium-Voltage (MV)-Directive 2008 and the TransmissionCode 2007. However, the work of the authors - consulting the German government during the development of the technical ordinance - showed that the TransmissionCode 2007 needed careful review and some clarifying specifications were proposed. Eventually, the so called ''Ancillary Services Ordinance'' for wind power plants went into power in July 2009. The interrelation between all three grid codes as well as their specifications and implications for renewable energy sources generators, with special regard to wind power plants, are presented in this paper. (orig.)

  15. Chiral condensate from the twisted mass Dirac operator spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, Krzysztof [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Garcia-Ramos, Elena [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Collaboration: European Twisted Mass Collaboration

    2013-03-15

    We present the results of our computation of the chiral condensate with N{sub f}=2 and N{sub f}=2+1+1 flavours of maximally twisted mass fermions. The condensate is determined from the Dirac operator spectrum, applying the spectral projector method proposed by Giusti and Luescher. We use 3 lattice spacings and several quark masses at each lattice spacing to reliably perform the chiral and continuum extrapolations. We study the effect of the dynamical strange and charm quarks by comparing our results for N{sub f}=2 and N{sub f}=2+1+1 dynamical flavours.

  16. Position Control of Switched Reluctance Motor Using Super Twisting Algorithm

    Directory of Open Access Journals (Sweden)

    Muhammad Rafiq Mufti

    2016-01-01

    Full Text Available The inherent problem of chattering in traditional sliding mode control is harmful for practical application of control system. This paper pays a considerable attention to a chattering-free control method, that is, higher-order sliding mode (super twisting algorithm. The design of a position controller for switched reluctance motor is presented and its stability is assured using Lyapunov stability theorem. In order to highlight the advantages of higher-order sliding mode controller (HOSMC, a classical first-order sliding mode controller (FOSMC is also applied to the same system and compared. The simulation results reflect the effectiveness of the proposed technique.

  17. Twisting, supercoiling and stretching in protein bound DNA

    Science.gov (United States)

    Lam, Pui-Man; Zhen, Yi

    2018-04-01

    We have calculated theoretical results for the torque and slope of the twisted DNA, with various proteins bound on it, using the Neukirch-Marko model, in the regime where plectonemes exist. We found that the torque in the protein bound DNA decreases compared to that in the bare DNA. This is caused by the decrease in the free energy g(f) , and hence the smaller persistence lengths, in the case of protein bound DNA. We hope our results will encourage experimental investigations of supercoiling in protein bound DNA, which can provide further tests of the Neukirch-Marko model.

  18. Analysis of the British Industrial Revolution in cinema: Oliver Twist

    OpenAIRE

    Fuente Diez, Óscar

    2015-01-01

    La Revolución Industrial británica fue un fenómeno histórico que incluso a día de hoy continúa atrayendo miradas. Sus dimensiones fueron tales que actualmente sus consecuencias aún son visibles. El objetivo de este proyecto es analizar el impacto social de la Revolución Industrial británica y las causas que llevaron a este punto como retrata Oliver Twist, la película seleccionada. Desde la perspectiva de las injusticias laborales y las desigualdades sociales, el estudio se centra en las conse...

  19. Chiral condensate from the twisted mass Dirac operator spectrum

    International Nuclear Information System (INIS)

    Cichy, Krzysztof; Jansen, Karl; Cyprus Univ., Nicosia

    2013-03-01

    We present the results of our computation of the chiral condensate with N f =2 and N f =2+1+1 flavours of maximally twisted mass fermions. The condensate is determined from the Dirac operator spectrum, applying the spectral projector method proposed by Giusti and Luescher. We use 3 lattice spacings and several quark masses at each lattice spacing to reliably perform the chiral and continuum extrapolations. We study the effect of the dynamical strange and charm quarks by comparing our results for N f =2 and N f =2+1+1 dynamical flavours.

  20. Wigner oscillators, twisted Hopf algebras and second quantization

    Energy Technology Data Exchange (ETDEWEB)

    Castro, P.G.; Toppan, F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: pgcastro@cbpf.br; toppan@cbpf.br; Chakraborty, B. [S. N. Bose National Center for Basic Sciences, Kolkata (India)]. E-mail: biswajit@bose.res.in

    2008-07-01

    By correctly identifying the role of central extension in the centrally extended Heisenberg algebra h, we show that it is indeed possible to construct a Hopf algebraic structure on the corresponding enveloping algebra U(h) and eventually deform it through Drinfeld twist. This Hopf algebraic structure and its deformed version U{sup F}(h) is shown to be induced from a more 'fundamental' Hopf algebra obtained from the Schroedinger field/oscillator algebra and its deformed version, provided that the fields/oscillators are regarded as odd-elements of a given superalgebra. We also discuss the possible implications in the context of quantum statistics. (author)

  1. Twisted speckle entities inside wave-front reversal mirrors

    International Nuclear Information System (INIS)

    Okulov, A. Yu

    2009-01-01

    The previously unknown property of the optical speckle pattern reported. The interference of a speckle with the counterpropagating phase-conjugated (PC) speckle wave produces a randomly distributed ensemble of a twisted entities (ropes) surrounding optical vortex lines. These entities appear in a wide range of a randomly chosen speckle parameters inside the phase-conjugating mirrors regardless to an internal physical mechanism of the wave-front reversal. These numerically generated interference patterns are relevant to the Brillouin PC mirrors and to a four-wave mixing PC mirrors based upon laser trapped ultracold atomic cloud.

  2. ABOUT THE GEOMETRY AND THE APPLICATIONS OF THE TWISTED SURFACES

    Directory of Open Access Journals (Sweden)

    MÂRZA Carmen

    2015-06-01

    Full Text Available The helical and spiral surfaces are used in various fields. These surfaces are obtained by rotating a segment line called generatrix around directrices lines, respectively the spiral surfaces are obtained by composing simultaneously the movements of translation and rotation of a plane figure around an axis - which can be a straight line or a curved line, or around a real or imaginary surface - called core. After an overview of these surfaces, the attention of the authors will be focused on the geometrical and graphical analysis of the twisted surfaces in civil engineering branch, such as: columns, helical ramps and stairs, respectively buildings having a futuristic design.

  3. Compactifications of 5d SCFTs with a twist

    Energy Technology Data Exchange (ETDEWEB)

    Zafrir, Gabi [Department of Physics, Technion - Israel Institute of Technology,32000, Haifa (Israel)

    2017-01-23

    We study the compactification of 5d SCFTs to 4d on a circle with a twist in a discrete global symmetry element of these SCFTs. We present evidence that this leads to various 4dN=2 isolated SCFTs. These include many known theories as well as seemingly new ones. The known theories include the recently discovered rank 1SU(4) SCFT and its mass deformations. One application of the new SCFTs is in the dual descriptions of the 4d gauge theory SU(N)+1S+(N−2)F. Also interesting is the appearance of a theory with rank 1 and F{sub 4} global symmetry.

  4. Light meson physics from maximally twisted mass lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Baron, R.; Boucaud, P. [Paris XI Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P. [Roma Tor Vergata Univ. (Italy). Dipt. di Fisica; INFN, Rome (IT)] (and others)

    2009-12-15

    We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N{sub f}=2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280

  5. Light meson physics from maximally twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Baron, R.; Boucaud, P.

    2009-12-01

    We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N f =2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280 PS < or similar 650 MeV we control the major systematic effects of our calculation. This enables us to confront our data with chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass, with high precision. (orig.)

  6. Nucleon electromagnetic form factors in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Alexandrou, C.; Jansen, K.; Korzec, T.; Humboldt Univ. Berlin

    2011-02-01

    We present results on the nucleon electromagnetic form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1 fm and L=2.8 fm. Cut-off effects are investigated using three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm. The nucleon magnetic moment, Dirac and Pauli radii are obtained in the continuum limit and chirally extrapolated to the physical pion mass allowing for a comparison with experiment. (orig.)

  7. Nucleon electromagnetic form factors in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    Alexandrou, C.; Brinet, M.; Carbonell, J.; Harraud, P. A.; Papinutto, M.; Guichon, P.; Jansen, K.; Korzec, T.; Constantinou, M.

    2011-01-01

    We present results on the nucleon electromagnetic form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1 fm and L=2.8 fm. Cutoff effects are investigated using three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm. The nucleon magnetic moment, Dirac and Pauli radii are obtained in the continuum limit and chirally extrapolated to the physical pion mass allowing for a comparison with experiment.

  8. Nucleon form factors with NF=2 twisted mass fermions

    International Nuclear Information System (INIS)

    Alexandrou, C.; Korzec, T.; Brinet, M.; Carbonell, J.; Harraud, P.A.; Jansen, K.

    2009-10-01

    We present results on the electromagnetic and axial nucleon form factors using two degenerate flavors of twisted mass fermions on lattices of spatial size 2.1 fm and 2.7 fm and a lattice spacing of about 0.09 fm. We consider pion masses in the range of 260-470MeV.We chirally extrapolate results on the nucleon axial charge, the isovector Dirac and Pauli root mean squared radii and magnetic moment to the physical point and compare to experiment. (orig.)

  9. The gradient flow running coupling with twisted boundary conditions

    International Nuclear Information System (INIS)

    Ramos, Alberto

    2014-09-01

    We study the gradient flow for Yang-Mills theories with twisted boundary conditions. The perturbative behavior of the energy density left angle E(t) right angle is used to define a running coupling at a scale given by the linear size of the finite volume box. We compute the non-perturbative running of the pure gauge SU(2) coupling constant and conclude that the technique is well suited for further applications due to the relatively mild cutoff effects of the step scaling function and the high numerical precision that can be achieved in lattice simulations. We also comment on the inclusion of matter fields.

  10. Twisting dirac fermions: circular dichroism in bilayer graphene

    Science.gov (United States)

    Suárez Morell, E.; Chico, Leonor; Brey, Luis

    2017-09-01

    Twisted bilayer graphene is a chiral system which has been recently shown to present circular dichroism. In this work we show that the origin of this optical activity is the rotation of the Dirac fermions’ helicities in the top and bottom layer. Starting from the Kubo formula, we obtain a compact expression for the Hall conductivity that takes into account the dephasing of the electromagnetic field between the top and bottom layers and gathers all the symmetries of the system. Our results are based in both a continuum and a tight-binding model, and they can be generalized to any two-dimensional Dirac material with a chiral stacking between layers.

  11. Five-loop anomalous dimension of twist-two operators

    Energy Technology Data Exchange (ETDEWEB)

    Lukowski, T. [Institute of Physics, Jagellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Rej, A. [Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Velizhanin, V.N., E-mail: velizh@mail.desy.d [Theoretical Physics Department, Petersburg Nuclear Physics Institute, Orlova Roscha, Gatchina, 188300 St. Petersburg (Russian Federation)

    2010-05-21

    In this article we calculate the five-loop anomalous dimension of twist-two operators in the planar N=4 SYM theory. Firstly, using reciprocity, we derive the contribution of the asymptotic Bethe ansatz. Subsequently, we employ the first finite-size correction for the AdS{sub 5}xS{sup 5} sigma model to determine the wrapping correction. The anomalous dimension found in this way passes all known tests provided by the NLO BFKL equation and double-logarithmic constraints. This result thus furnishes an infinite number of experimental data for testing the veracity of the recently proposed spectral equations for planar AdS/CFT correspondence.

  12. Traveling waves in twisted nematic liquid crystal cells

    International Nuclear Information System (INIS)

    Zakharov, A.V.; Vakulenko, A.A.

    2007-01-01

    We have described a novel reorientation mechanism in the form of the traveling waves, under influence of an external electric field, directed parallel to both glass plates, which occur in the twisted nematic cell (TNC). It is found that the slowest velocity of the traveling front is proportional to the field strength, and, approximately, in three times higher than the front velocity corresponding to the non-traveling solution. The value of the critical electric field E cr which may excite the traveling waves in the TNC in π times less than the value of the threshold electric field E th corresponding to the untwisted geometry

  13. Resource and revenue potential of California residential load participation in ancillary services

    International Nuclear Information System (INIS)

    Mathieu, Johanna L.; Dyson, Mark E.H.; Callaway, Duncan S.

    2015-01-01

    Increasing penetrations of intermittent renewable energy resources will require additional power system services. California recently adopted an energy storage mandate to support its renewable portfolio standard, which requires 33% of delivered energy from renewables by 2020. The objective of this paper is to estimate the amount of energy storage that could be provided by residential thermostatically controlled loads, such as refrigerators and air conditioners, and the amount of revenue that could be earned by loads participating in ancillary services markets. We model load aggregations as virtual energy storage, and use simple dynamical system models and publicly available data to generate our resource and revenue estimates. We find that the resource potential is large: 10–40 GW/8–12 GWh, which is significantly more than that required by the mandate. We also find that regulation and spinning/non-spinning reserve revenues vary significantly depending upon type of load and, for heat pumps and air conditioners, climate zone. For example, mean regulation revenues for refrigerators are $11/year, for electric water heaters are $24/year, for air conditioners are $0-32/year, and for heat pumps are $22–56/year. Both consumer choices, such as appliance settings, and policy, such as the design of ancillary service compensation and appliance standards, could increase revenue potentials. - Highlights: • California's energy storage mandate requires 1.325 GW of energy storage by 2020. • Residential loads such as refrigerators have thermal energy storage. • California's residential loads could provide 10-40 GW/8-12 GWh of storage. • Loads participating in ancillary services markets could earn up to $56/load/year. • Consumer choices and policy mechanisms could increase revenue potentials

  14. Modal properties and stability of bend–twist coupled wind turbine blades

    Directory of Open Access Journals (Sweden)

    A. R. Stäblein

    2017-06-01

    Full Text Available Coupling between bending and twist has a significant influence on the aeroelastic response of wind turbine blades. The coupling can arise from the blade geometry (e.g. sweep, prebending, or deflection under load or from the anisotropic properties of the blade material. Bend–twist coupling can be utilized to reduce the fatigue loads of wind turbine blades. In this study the effects of material-based coupling on the aeroelastic modal properties and stability limits of the DTU 10 MW Reference Wind Turbine are investigated. The modal properties are determined by means of eigenvalue analysis around a steady-state equilibrium using the aero-servo-elastic tool HAWCStab2 which has been extended by a beam element that allows for fully coupled cross-sectional properties. Bend–twist coupling is introduced in the cross-sectional stiffness matrix by means of coupling coefficients that introduce twist for flapwise (flap–twist coupling or edgewise (edge–twist coupling bending. Edge–twist coupling can increase or decrease the damping of the edgewise mode relative to the reference blade, depending on the operational condition of the turbine. Edge–twist to feather coupling for edgewise deflection towards the leading edge reduces the inflow speed at which the blade becomes unstable. Flap–twist to feather coupling for flapwise deflections towards the suction side increase the frequency and reduce damping of the flapwise mode. Flap–twist to stall reduces frequency and increases damping. The reduction of blade root flapwise and tower bottom fore–aft moments due to variations in mean wind speed of a flap–twist to feather blade are confirmed by frequency response functions.

  15. Cerclage handling for improved fracture treatment. A biomechanical study on the twisting procedure.

    Science.gov (United States)

    Wähnert, D; Lenz, M; Schlegel, U; Perren, S; Windolf, M

    2011-01-01

    Twisting is clinically the most frequently applied method for tightening and maintaining cerclage fixation. The twisting procedure is controversially discussed. Several factors during twisting affect the mechanical behaviour of the cerclage. This in vitro study investigated the influence of different parameters of the twisting procedure on the fixation strength of the cerclage in an experimental setup with centripetal force application. Cortical half shells of the femoral shaft were mounted on a testing fixture. 1.0 mm, 1.25 mm and 1.5 mm stainless ste- el wire cerclages as well as a 1.0mm cable cerclage were applied to the bone. Pretension of the cerclage during the installation was measured during the locking procedure. Subsequently, cyclic testing was performed up to failure. Higher pretension could be achieved with increasing wire diameter. However, with larger wire diameter the drop of pre- tension due to the bending and cutting the twist also increased. The cable cerclage showed the highest pretension after locking. Cerclages twisted under traction revealed significantly higher initial cerclage tension. Plastically deformed twists offered higher cerclage pretension compared to twists which were deformed in the elastic region of the material. Cutting the wire within the twist caused the highest loss of cerclage tension (44% initial tension) whereas only 11 % was lost when cutting the wire ends separately. The bending direction of the twist significantly influenced the cerclage pretension. 45% pretension was lost in forward bending of the twist, 53% in perpendicular bending and 90% in backward bending. Several parameters affect the quality of a cerclage fixation. Adequate installation of cerclage wires could markedly improve the clinical outcome of cerclage.

  16. Evaluation of Contribution for Voltage Control Ancillary Services Based on Social Surplus

    Science.gov (United States)

    Ueki, Yuji; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

    Reactive power supply plays an important role in active power supply with adequate system voltages. Various pricing mechanism for reactive power supply have been developed and some of them are adopted in some power systems, however they are in a trial stage. The authors also focus on development of a pricing method for reactive power ancillary services. This problem involves two technical issues: rational estimation of the cost associated with reactive power supply and fair and transparent allocation of the estimated cost among the market participants. This paper proposes methods for evaluating the contribution of generators and demands.

  17. Opportunities for ice storage to provide ancillary services to power grids incorporating wind turbine generation

    Science.gov (United States)

    Finley, Christopher

    Power generation using wind turbines increases the electrical system balancing, regulation and ramp rate requirements due to the minute to minute variability in wind speed and the difficulty in accurately forecasting wind speeds. The addition of thermal energy storage, such as ice storage, to a building's space cooling equipment increases the operational flexibility of the equipment by allowing the owner to choose when the chiller is run. The ability of the building owner to increase the power demand from the chiller (e.g. make ice) or to decrease the power demand (e.g. melt ice) to provide electrical system ancillary services was evaluated.

  18. Molecular Structure Laboratory. Fourier Transform Nuclear Magnetic Resonance (FTNMR) Spectrometer and Ancillary Instrumentation at SUNY Geneseo

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, David K [State Univ. of New York (SUNY), Geneseo, NY (United States)

    2015-12-31

    An Agilent 400-MR nuclear magnetic resonance (NMR) spectrometer and ancillary equipment were purchased, which are being used for molecular structure elucidation.  The instrumentation is housed in a pre-existing facility designed specifically for its use. This instrument package is being used to expand the research and educational efforts of the faculty and students at SUNY-Geneseo and is made available to neighboring educational institutions and business concerns.  Funds were also used for training of College personnel, maintenance of the instrumentation, and installation of the equipment.

  19. Identification of Conflicts between Transmission and Distribution System Operators when Acquiring Ancillary Services from Electric Vehicles

    DEFF Research Database (Denmark)

    Zecchino, Antonio; Knezovic, Katarina; Marinelli, Mattia

    2017-01-01

    ancillary services from flexible units. The investigation is carried out considering a 3-area power system which allows to take into account local constraints as well as system-wide needs. As outcome, this paper identifies the conflicts from both a theoretical and a practical point of view, by means...... products according to requests coming from both distribution and transmission system operators. The goal of this paper is to provide an identification procedure that is able to detect, identify and catalogue possible conflicts among the involved stakeholders that take place when requesting and/or acquiring...

  20. The topological B model as a twisted spinning particle

    International Nuclear Information System (INIS)

    Marcus, Neil; Yankielowicz, Shimon

    1994-01-01

    The B-twisted topological sigma model coupled to topological gravity is supposed to be described by an ordinary field theory: a type of holomorphic Chern-Simons theory for the open string, and the Kodaira-Spencer theory for the closed string. We show that the B model can be represented as a particle theory, obtained by reducing the sigma model to one dimension, and replacing the coupling to topological gravity by a coupling to a twisted one-dimensional supergravity. The particle can be defined on any Kaehler manifold - it does not require the Calabi-Yau condition - so it may provide a more generalized setting for the B model than the topological sigma model.The one-loop partition function of the particle can be written in terms of the Ray-Singer torsion of the manifold, and agrees with that of the original B model. After showing how to deform the Kaehler and complex structures in the particle, we prove the independence of this partition function on the Kaehler structure, and investigate the origin of the holomorphic anomaly. To define other amplitudes, one needs to introduce interactions into the particle. The particle will then define a field theory, which may or may not be the Chern-Simons or Kodaira-Spencer theories. ((orig.))

  1. Angular momentum transport with twisted exciton wave packets

    Science.gov (United States)

    Zang, Xiaoning; Lusk, Mark T.

    2017-10-01

    A chain of cofacial molecules with CN or CN h symmetry supports excitonic states with a screwlike structure. These can be quantified with the combination of an axial wave number and an azimuthal winding number. Combinations of these states can be used to construct excitonic wave packets that spiral down the chain with well-determined linear and angular momenta. These twisted exciton wave packets can be created and annihilated using laser pulses, and their angular momentum can be optically modified during transit. This allows for the creation of optoexcitonic circuits in which information, encoded in the angular momentum of light, is converted into excitonic wave packets that can be manipulated, transported, and then reemitted. A tight-binding paradigm is used to demonstrate the key ideas. The approach is then extended to quantify the evolution of twisted exciton wave packets in a many-body, multilevel time-domain density functional theory setting. In both settings, numerical methods are developed that allow the site-to-site transfer of angular momentum to be quantified.

  2. Reconstruction of Twist Torque in Main Parachute Risers

    Science.gov (United States)

    Day, Joshua D.

    2015-01-01

    The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

  3. The dipole representation of vector meson electroproduction beyond leading twist

    Energy Technology Data Exchange (ETDEWEB)

    Besse, A. [LPT, Universite Paris-Sud, CNRS, 91405, Orsay (France); Szymanowski, L. [National Center for Nuclear Research (NCBJ), Warsaw (Poland); Wallon, S., E-mail: wallon@th.u-psud.fr [LPT, Universite Paris-Sud, CNRS, 91405, Orsay (France); UPMC Univ. Paris 06, Faculte de Physique, 4 place Jussieu, 75252 Paris Cedex 05 (France)

    2013-02-01

    We link the recent computation beyond leading twist of the impact factor of the transition {gamma}{sub T}{sup Low-Asterisk }{yields}{rho}{sub T} performed in the light-cone collinear approach, to the dipole picture by expressing the hard part of the process through its Fourier transform in coordinate space. We show that in the Wandzura-Wilczek approximation the impact factor up to twist 3 factorises in the wave function of the photon combined with the distribution amplitudes of the {rho}-meson and the colour dipole scattering amplitude with the t-channel gluons. We show also that beyond the Wandzura-Wilczek approximation, the hard contribution of the amplitude still exhibits the signature of the interaction of a single colour dipole with the t-channel gluons. This result allows a phenomenological approach of the helicity amplitudes of the leptoproduction of vector meson, by combining our results to a dipole/target scattering amplitude model.

  4. Beams made of twisted atoms: A theoretical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hayrapetyan, Armen [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, 69120 Heidelberg (Germany); Matula, Oliver [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, 69120 Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Surzhykov, Andrey [Helmholtz-Institut Jena, 07743 Jena (Germany); Fritzsche, Stephan [Helmholtz-Institut Jena, 07743 Jena (Germany); Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet Jena, 07743 Jena (Germany)

    2014-07-01

    We have analyzed Bessel beams of two-level atoms that are driven by a linearly polarized laser light. Based on the Schroedinger equation for two-level systems, we first determine the states of two-level atoms in a plane-wave field by taking into account propagation directions both of the atom and the field. For such laser-driven two-level atoms, we construct Bessel beams by going beyond the typical paraxial approximation. In particular, we show that the probability density of these atomic beams exhibits a non-trivial, Bessel-squared-type behavior. The profile of such twisted atoms is affected by atom and laser parameters, such as the nuclear charge, atom velocity, laser frequency, and propagation geometry of the atom and laser beams. Moreover, we spatially and temporally characterize the beam of hydrogen and selected (neutral) alkali-metal atoms that carry non-zero orbital angular momentum (OAM). The proposed spatiotemporal Bessel states (i) are able to describe twisted states of any two-level system which is driven by the radiation field and (ii) have potential applications in atomic and nuclear processes as well as in quantum communication.

  5. M(atrix) theory on an orbifold and twisted membrane

    International Nuclear Information System (INIS)

    Kim, N.

    1997-01-01

    M(atrix) theory on an orbifold and classical two-branes therein are studied with particular emphasis on heterotic M(atrix) theory on S 1 / Z 2 relevant to strongly coupled heterotic and dual type IA string theories. By analyzing the orbifold condition on Chan-Paton factors, we show that three choices of gauge group are possible for heterotic M(atrix) theory: SO(2N), SO(2N+1) or USp(2N). By examining the area-preserving diffeomorphism that underlies the M(atrix) theory, we find that each choice of gauge group restricts the possible topologies of two-branes. The result suggests that only the choice of SO(2N) or SO(2N+1) allows open two-branes, and hence, is relevant to heterotic M(atrix) theory. We show that the requirement of both local vacuum energy cancellation and of world-sheet anomaly cancellation of the resulting heterotic string identifies supersymmetric twisted sector spectra with sixteen fundamental representation spinors from each of the two fixed points. Twisted open and closed two-brane configurations are obtained in the large N limit. (orig.)

  6. Dickens's Dichotomous Formula for Social Reform In Oliver Twist

    Directory of Open Access Journals (Sweden)

    Taher Badinjki

    2016-11-01

    Full Text Available Oliver Twist was a direct appeal to society to take action against poverty, exploitation of children, oppression of women, and was meant to be a picture of the "dregs of life” in all their deformity and wretchedness. Among the most miserable inhabitants of the world of Oliver Twist, Nancy appears as a key figure.  Dickens was anxious to expose the truth about such a woman because he believed it would be a service to society. Dickens's portrayal of Nancy illustrates the power of the dual conception of womanhood  held at the time. On the one hand, a woman might be conceived as someone refined and somewhat remote from ordinary life like Rose Maylie. On the other hand, there was a certain fascination in a woman's degradation, even though that could be shown only indirectly.  Nancy is a demonstration of the two elements combined together. Dickens took the ideal nature of womanhood  and the depravity of the prostitute, and combined them in a remarkable dramatization which he had some right to claim was also true to life. The book is an astounding rebuttal of contemporary prejudice, and a call for more humane and liberal attitudes. These attitudes  are based on the concepts that there is now a radically different way of looking at human nature, that everything ought to depend on what one is in oneself, and that it is only in love that humans can live purposefully and happily with each other.

  7. Friction spinning - Twist phenomena and the capability of influencing them

    Science.gov (United States)

    Lossen, Benjamin; Homberg, Werner

    2016-10-01

    The friction spinning process can be allocated to the incremental forming techniques. The process consists of process elements from both metal spinning and friction welding. The selective combination of process elements from these two processes results in the integration of friction sub-processes in a spinning process. This implies self-induced heat generation with the possibility of manufacturing functionally graded parts from tube and sheets. Compared with conventional spinning processes, this in-process heat treatment permits the extension of existing forming limits and also the production of more complex geometries. Furthermore, the defined adjustment of part properties like strength, grain size/orientation and surface conditions can be achieved through the appropriate process parameter settings and consequently by setting a specific temperature profile in combination with the degree of deformation. The results presented from tube forming start with an investigation into the resulting twist phenomena in flange processing. In this way, the influence of the main parameters, such as rotation speed, feed rate, forming paths and tool friction surface, and their effects on temperature, forces and finally the twist behavior are analyzed. Following this, the significant correlations with the parameters and a new process strategy are set out in order to visualize the possibility of achieving a defined grain texture orientation.

  8. The ρ-meson longitudinal leading-twist distribution amplitude

    Directory of Open Access Journals (Sweden)

    Hai-Bing Fu

    2014-11-01

    Full Text Available In the present paper, we suggest a convenient model for the vector ρ-meson longitudinal leading-twist distribution amplitude ϕ2;ρ‖, whose distribution is controlled by a single parameter B2;ρ‖. By choosing proper chiral current in the correlator, we obtain new light-cone sum rules (LCSR for the B→ρ TFFs A1, A2 and V, in which the δ1-order ϕ2;ρ‖ provides dominant contributions. Then we make a detailed discussion on the ϕ2;ρ‖ properties via those B→ρ TFFs. A proper choice of B2;ρ‖ can make all the TFFs agree with the lattice QCD predictions. A prediction of |Vub| has also been presented by using the extrapolated TFFs, which indicates that a larger B2;ρ‖ leads to a larger |Vub|. To compare with the BABAR data on |Vub|, the longitudinal leading-twist DA ϕ2;ρ‖ prefers a doubly-humped behavior.

  9. Sox5 induces epithelial to mesenchymal transition by transactivation of Twist1

    International Nuclear Information System (INIS)

    Pei, Xin-Hong; Lv, Xin-Quan; Li, Hui-Xiang

    2014-01-01

    Highlights: • Depletion of Sox5 inhibits breast cancer proliferation, migration, and invasion. • Sox5 transactivates Twist1 expression. • Sox5 induces epithelial to mesenchymal transition through transactivation of Twist1 expression. - Abstract: The epithelial to mesenchymal transition (EMT), a highly conserved cellular program, plays an important role in normal embryogenesis and cancer metastasis. Twist1, a master regulator of embryonic morphogenesis, is overexpressed in breast cancer and contributes to metastasis by promoting EMT. In exploring the mechanism underlying the increased Twist1 in breast cancer cells, we found that the transcription factor SRY (sex-determining region Y)-box 5(Sox5) is up-regulation in breast cancer cells and depletion of Sox5 inhibits breast cancer cell proliferation, migration, and invasion. Furthermore, depletion of Sox5 in breast cancer cells caused a dramatic decrease in Twist1 and chromosome immunoprecipitation assay showed that Sox5 can bind directly to the Twist1 promoter, suggesting that Sox5 transactivates Twist1 expression. We further demonstrated that knockdown of Sox5 up-regulated epithelial phenotype cell biomarker (E-cadherin) and down-regulated mesenchymal phenotype cell biomarkers (N-cadherin, Vimentin, and Fibronectin 1), resulting in suppression of EMT. Our study suggests that Sox5 transactivates Twist1 expression and plays an important role in the regulation of breast cancer progression

  10. The geometrical origin of the strain-twist coupling in double helices

    DEFF Research Database (Denmark)

    Olsen, Kasper; Bohr, Jakob

    2011-01-01

    A simple geometrical explanation for the counterintuitive phenomenon when twist leads to extension in double helices is presented. The coupling between strain and twist is investigated using a tubular description. It is shown that the relation between strain and rotation is universal and depends...

  11. Effect of Magnetic Twist on Nonlinear Transverse Kink Oscillations of Line-tied Magnetic Flux Tubes

    Science.gov (United States)

    Terradas, J.; Magyar, N.; Van Doorsselaere, T.

    2018-01-01

    Magnetic twist is thought to play an important role in many structures of the solar atmosphere. One of the effects of twist is to modify the properties of the eigenmodes of magnetic tubes. In the linear regime standing kink solutions are characterized by a change in polarization of the transverse displacement along the twisted tube. In the nonlinear regime, magnetic twist affects the development of shear instabilities that appear at the tube boundary when it is oscillating laterally. These Kelvin–Helmholtz instabilities (KHI) are produced either by the jump in the azimuthal component of the velocity at the edge of the sharp boundary between the internal and external part of the tube or by the continuous small length scales produced by phase mixing when there is a smooth inhomogeneous layer. In this work the effect of twist is consistently investigated by solving the time-dependent problem including the process of energy transfer to the inhomogeneous layer. It is found that twist always delays the appearance of the shear instability, but for tubes with thin inhomogeneous layers the effect is relatively small for moderate values of twist. On the contrary, for tubes with thick layers, the effect of twist is much stronger. This can have some important implications regarding observations of transverse kink modes and the KHI itself.

  12. Light hadrons from Nf=2+1+1 dynamical twisted mass fermions

    NARCIS (Netherlands)

    Baron, R.; Blossier, B.; Boucaud, P.; Carbonell, J.; Deuzeman, A.; Drach, V.; Farchioni, F.; Gimenez, V.; Herdoiza, G.; Jansen, K.; Michael, C.; Montvay, I.; Pallante, E.; Pène, O.; Reker, S.; Urbach, C.; Wagner, M.; Wenger, U.; Collaboration, for the ETM

    2011-01-01

    We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (Nf=2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at three values of the lattice spacing a~0.06

  13. First results of ETMC simulations with Nf=2+1+1 maximally twisted mass fermions

    NARCIS (Netherlands)

    Baron, R.; Blossier, B.; Boucaud, P.; Deuzeman, A.; Drach, V.; Farchioni, F.; Gimenez, V.; Herdoiza, G.; Jansen, K.; Michael, C.; Montvay, I.; Palao, D.; Pallante, E.; Pène, O.; Reker, S.; Urbach, C.; Wagner, M.; Wenger, U.; Collaboration, for the ETM

    2009-01-01

    We present first results from runs performed with Nf=2+1+1 flavours of dynamical twisted mass fermions at maximal twist: a degenerate light doublet and a mass split heavy doublet. An overview of the input parameters and tuning status of our ensembles is given, together with a comparison with results

  14. Vacuum fluctuations of twisted fields in the space time of cosmic strings

    International Nuclear Information System (INIS)

    Matsas, G.E.A.

    1990-01-01

    A twisted scalar field conformally coupled to gravitation is used to calculate the vacuum stress-energy tensor in the background spacetime generated by an infinite straight gauge cosmic string. The result has an absolute numerical value close to the one obtained with a non-twisted conformal scalar field but their signals are opposite. (author) [pt

  15. Modification of the twist angle in chiral nematic polymer films by photoisomerization of the chiral dopant

    NARCIS (Netherlands)

    Witte, van de P.; Neuteboom, E.E.; Brehmer, M.; Lub, Johan

    1999-01-01

    A method for the production of polarization sensitive recordings in liquid crystalline polymers is presented. The system is based on local modification of the twist angle of chiral nematic polymer films. The twist angle of the polymer film is varied by modifying the chemical structure of the chiral

  16. Higher twist effects in QCD description of light meson exclusive formfactors

    International Nuclear Information System (INIS)

    Gorskij, A.S.

    1987-01-01

    The general approach to a quantitative description of higher twist effects in hard exclusive processes in QCD is proposed. The consistent calculations in coordinate space and the choice of special gauges for quantum and classical gluon fields are essential ingradients of this method. The self consistent system of twist three wave functions for π-meson has been built

  17. Translational control of TWIST1 expression in MCF-10A cell lines recapitulating breast cancer progression

    DEFF Research Database (Denmark)

    Nairismägi, Maarja-Liisa; Vislovukh, Andrii; Meng, Q

    2012-01-01

    and EMT, we found TWIST1 to be upregulated during EMT and downregulated early in carcinogenesis. The TWIST1 3′UTR contains putative regulatory elements, including miRNA target sites and two cytoplasmic polyadenylation elements (CPE). We found that miR-580, CPEB1, and CPEB2 act as negative regulators...

  18. Comparison of split double and triple twists in pair figure skating.

    Science.gov (United States)

    King, Deborah L; Smith, Sarah L; Brown, Michele R; McCrory, Jean L; Munkasy, Barry A; Scheirman, Gary I

    2008-05-01

    In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.

  19. On the propagation and the twist of Gaussian light in first-order optical systems

    NARCIS (Netherlands)

    Bastiaans, M.J.; Nijhawan, O.P.; Gupta, A.K.; Musla, A.K.; Singh, Kehar

    1998-01-01

    A measure for the twist of Gaussian light is expressed in terms of the second-order moments of the Wigner distribution function. The propagation law for these moments through first-order optical systems is used to express the twist in the output plane in terms of moments in the input plane, and vice

  20. Modal Properties and Stability of Bend-Twist Coupled Wind Turbine Blades

    DEFF Research Database (Denmark)

    Stäblein, Alexander R.; Hansen, Morten Hartvig; Verelst, David Robert

    2017-01-01

    a steady-state equilibrium using the aero-servo-elastic tool HAWCStab2 which has been extended by a beam element that allows for fully coupled cross-sectional properties. Bend-twist coupling is introduced in the cross-sectional stiffness matrix by means of coupling coefficients that introduce twist...

  1. Osserman and conformally Osserman manifolds with warped and twisted product structure

    OpenAIRE

    Brozos-Vazquez, M.; Garcia-Rio, E.; Vazquez-Lorenzo, R.

    2008-01-01

    We characterize Osserman and conformally Osserman Riemannian manifolds with the local structure of a warped product. By means of this approach we analyze the twisted product structure and obtain, as a consequence, that the only Osserman manifolds which can be written as a twisted product are those of constant curvature.

  2. Does accessory pathway significantly alter left ventricular twist/torsion? A study in Wolff-Parkinson-White syndrome by velocity vector imaging.

    Science.gov (United States)

    Aminian, Farimah; Esmaeilzadeh, Maryam; Moladoust, Hassan; Maleki, Majid; Shahrzad, Soraya; Emkanjoo, Zahra; Sadeghpour, Anita

    2014-08-01

    The aim of this study was to determine the impact of manifest accessory pathway on left ventricle (LV) twist physiology in Wolff-Parkinson-White (WPW) patients. Although this issue was addressed in 1 study based on speckle tracking method, there was no comparative study with a different technique. We planned to use velocity vector imaging (VVI) to find out how much an accessory pathway can affect LV twist mechanics. Thirty patients were enrolled regarding inclusion and exclusion criteria. Two serial comprehensive transthoracic echocardiography evaluations were performed before and after radiofrequency catheter ablation (RFCA) within 24 hours. Stored cine loops were analyzed using VVI technique and LV twist and related parameters were extracted. Comparing pre- and post-RFCA data, no significant changes were observed in LV systolic and diastolic dimensions, LV ejection fraction (LVEF), and Doppler and tissue Doppler-related parameters. VVI study revealed remarkable rise in peak LV apical rotation (10.3º ± 3.0º to 13.8º ± 3.6º, P < 0.001) and basal rotation (-6.0 ± 1.8º to -7.7 ± 1.8º, P < 0.001) after RFCA. Subsequently LV twist showed a surge from 14.7º ± 3.9º to 20.2º ± 4.4º (P < 0.001). LV untwisting rate changed significantly from -96 ± 67 to -149.0 ± 47.5°/sec (P < 0.001) and apical-basal rotation delay showed a remarkable decline after RFCA (106 ± 81 vs. 42.8 ± 26.0 msec, P < 0.001). Accessory pathways have a major impact on LV twist mechanics. © 2013, Wiley Periodicals, Inc.

  3. Crisis in our hospital kitchens: ancillary staffing levels during an outbreak of food poisoning in a long stay hospital.

    Science.gov (United States)

    Pollock, A M; Whitty, P M

    1990-02-10

    An investigation into an outbreak of food poisoning caused by Clostridium perfringens showed evidence of poor food handling by catering staff. The reasons behind this were explored by interviewing catering staff, analysing shifts and rotas, and looking at staff vacancies. Morale was low because of staff shortages resulting from a long term recruitment problem. In consequence staff were working double shifts and often for weeks on end without a day off. The reasons for the recruitment problem included the difficulty of recruiting semiskilled labour from a middle class area, low wages, lack of management support, and the poor image of the hospital as a place of work. Similar factors affect the recruitment and retention of ancillary staff nationally. The NHS has a poor record as an employer of ancillary staff, paying lower wages than other organisations for equivalent posts. Competitive tendering has further worsened the position of ancillary staff, with the result that good quality of care and service has often not been achieved. The NHS Review, with its emphasis on quality of care, makes no mention of ancillary staff. Yet high standards of ancillary provision are essential if further outbreaks of food poisoning in hospitals are to be prevented.

  4. Market and Policy Barriers for Demand Response Providing Ancillary Services in U.S. Markets

    Energy Technology Data Exchange (ETDEWEB)

    Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); MacDonald, Jason [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goldman, Charles [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-03-01

    In this study, we attempt to provide a comprehensive examination of various market and policy barriers to demand response providing ancillary services in both ISO/RTO and non-ISO/RTO regions, especially at the program provider level. It is useful to classify barriers in order to create a holistic understanding and identify parties that could be responsible for their removal. This study develops a typology of barriers focusing on smaller customers that must rely on a program provider (i.e., electric investor owned utility or IOU, ARC) to create an aggregated DR resource in order to bring ancillary services to the balancing authority.ii The barriers were identified through examinations of regulatory structures, market environments, and product offerings; and discussions with industry stakeholders and regulators. In order to help illustrate the differences in barriers among various wholesale market designs and their constituent retail environments, four regions were chosen to use as case studies: Colorado, Texas, Wisconsin, and New Jersey. We highlight the experience in each area as it relates to the identified barriers.

  5. MR imaging diagnosis of posterior cruciate ligament injury: importance of ancillary findings

    International Nuclear Information System (INIS)

    Hwang, Kang Ik; Lee, Jong Hwa; Kim, Young Sun; Lee, Jung Hwoi; Ki, Tae Sung; Park, Jong Oag

    1997-01-01

    To evaluate the importance of two ancillary findings of anterior tibial plateau bruise/fracture and popliteus muscle strain on MR diagnosis of posterior cruicate ligament injury. We retrospectively evaluated 48 patients with confirmed posterior cruciate ligament tear. We studied the incidence of anterior tibial plateau injury and popliteus muscle strain, and the specificity of popliteus muscle strain with or without bony injury. A complete tear of the posterior cruciate ligament was noted in 37 cases, a partial tear in 11. Anterior tibial plateau lesion was found in 21 of 48 cases (44%); This total was made up of 17/37 PCL complete tears (46%) and 4/11 partial tears (36%). The difference in the incidence of complete and partial tears is not statistically significant. Popliteus muscle injury was found in 20 of 48 cases (42%), the total consisted of 19/37 PCL complete tears (51%) and 1/11 partial tears (10%). The incidence of 42% is relatively high, approximating that of bony injury. The difference in the incidence of complete and partial tears is statistically significant (p < 0.006). Specificity for posterior cruciate ligament tear is 69%(20/29), and when concomitant with anterior tibial plateau injury is 94%(16/17). As in the case of anterior cruciate ligament injury, these documented ancillary findings of anterior tibial plateau and popliteus muscle injuries are very helpful when MR diagnosis of posterior cruciate ligament injury itself and differentiation of partial and complete rupture are doubtful

  6. Open Automated Demand Response Communications in Demand Response for Wholesale Ancillary Services

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila; Piette, Mary Ann; Ghatikar, Girish; Koch, Ed; Hennage, Dan; Hernandez, John; Chiu, Albert; Sezgen, Osman; Goodin, John

    2009-11-06

    The Pacific Gas and Electric Company (PG&E) is conducting a pilot program to investigate the technical feasibility of bidding certain demand response (DR) resources into the California Independent System Operator's (CAISO) day-ahead market for ancillary services nonspinning reserve. Three facilities, a retail store, a local government office building, and a bakery, are recruited into the pilot program. For each facility, hourly demand, and load curtailment potential are forecasted two days ahead and submitted to the CAISO the day before the operation as an available resource. These DR resources are optimized against all other generation resources in the CAISO ancillary service. Each facility is equipped with four-second real time telemetry equipment to ensure resource accountability and visibility to CAISO operators. When CAISO requests DR resources, PG&E's OpenADR (Open Automated DR) communications infrastructure is utilized to deliver DR signals to the facilities energy management and control systems (EMCS). The pre-programmed DR strategies are triggered without a human in the loop. This paper describes the automated system architecture and the flow of information to trigger and monitor the performance of the DR events. We outline the DR strategies at each of the participating facilities. At one site a real time electric measurement feedback loop is implemented to assure the delivery of CAISO dispatched demand reductions. Finally, we present results from each of the facilities and discuss findings.

  7. An integrated pan-European ancillary services market for frequency control

    International Nuclear Information System (INIS)

    Scherer, Marc; Zima, Marek; Andersson, Göran

    2013-01-01

    Real-time balancing of mismatches between consumption and production is one of the key elements for the secure operation of power systems. This takes place within the framework of ancillary services managed by respective national transmission system operating companies. The objective of this paper is to investigate the option of one integrated pan-European ancillary services market. Our contribution is twofold: quantifying the potential benefit of such an option and outlining a possible approach to such an option highlighting its positive properties as well as risks and challenges. In several recently published considerations of pan-European electricity supply models this topic has not been adequately addressed, but we believe it is one of the crucial subjects in shaping the future electricity supply in Europe. -- Author-Highlights: •We investigated the option of a one-area market for frequency control in Continental Europe. •For the current situation a centralised approach may lead to a significant reduction of control reserves. •In the long run it is a possibility to avoid a tremendous increase of needed control reserves. •The implementation of an integrated market is not to be underestimated

  8. Pipe stress analysis on HCCR-TBS ancillary systems in conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Mu-Young, E-mail: myahn74@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of); Lee, Eo Hwak [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi-Hyun; Lee, Youngmin [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2016-11-01

    Highlights: • Pipe stress is performed on Korean HCCR-TBS for the load combinations including seismic events. • The resultant stress meets the requirement of the design code & standard except one position where modification is needed. • The results gives useful information for the design evolution in the next desgin phase. - Abstract: Korean Helium Cooled Ceramic Reflector (HCCR) Test Blanket System (TBS) will be tested in ITER to demonstrate feasibility of the breeding blanket concept. The HCCR-TBS comprises Test Blanket Module (TBM) with associated shield, and ancillary systems located in various positions of ITER building. Currently, conceptual design for the HCCR-TBS is in progress. This paper presents pipe stress analysis results for the HCCR-TBS ancillary systems. The pipe stress analysis was performed in accordance with ASME B31.3 for major pipes of the Helium Cooling System (HCS) and the Coolant Purification System (CPS), which are operated in high pressure and temperature. The pipe stress for various load cases and load combinations were calculated. Operational pressure and temperature during plasma operation are applied as pressure load and thermal load, respectively. In addition seismic events were combined to investigate the code compliance for sustained load case and occasional load case. It was confirmed that the resultant stress meets the requirements of ASME B31.3 except one position in which it needs modification. These results give useful information for the next design phase, for example, nozzle loads for the component selection, the support design parameters, etc.

  9. Optimal bidding strategy for microgrids in joint energy and ancillary service markets considering flexible ramping products

    International Nuclear Information System (INIS)

    Wang, Jianxiao; Zhong, Haiwang; Tang, Wenyuan; Rajagopal, Ram; Xia, Qing; Kang, Chongqing; Wang, Yi

    2017-01-01

    Highlights: •Flexible ramping products are modelled in the framework of a microgrid. •Microgrids’ optimal bidding model is proposed in energy and ancillary service markets. •A hybrid stochastic and robust optimization approach is adopted. •The effectiveness of the proposed bidding model is verified based on real-world data. -- Abstract: Due to the volatile nature of wind and photovoltaic power, wind farms and solar stations are generally thought of as the consumers of ramping services. However, a microgrid (MG) is able to strategically integrate various distributed energy resources (DERs) to provide both energy and ancillary services (ASs) for the bulk power system. To evaluate the ramping capabilities of an MG in the joint energy and AS markets, an optimal bidding strategy is developed in this paper considering flexible ramping products (FRPs). By aggregating and coordinating various DERs, including wind turbines (WTs), photovoltaic systems (PVs), micro-turbines (MTs) and energy storage systems (ESSs), the MG is able to optimally allocate the capacities for energy, spinning reserve and ramping. Taking advantage of the synergy among DERs, the MG can maximize its revenues from different markets. Moreover, the flexibility of the MG for the bulk power system can be fully explored. To address the uncertainties introduced by renewable generation and market prices, a hybrid stochastic/robust optimization (RO) approach is adopted. Case studies based on a real-world MG with various DERs demonstrate the market behavior of the MG using the proposed bidding model.

  10. Pipe stress analysis on HCCR-TBS ancillary systems in conceptual design

    International Nuclear Information System (INIS)

    Ahn, Mu-Young; Cho, Seungyon; Lee, Eo Hwak; Park, Yi-Hyun; Lee, Youngmin

    2016-01-01

    Highlights: • Pipe stress is performed on Korean HCCR-TBS for the load combinations including seismic events. • The resultant stress meets the requirement of the design code & standard except one position where modification is needed. • The results gives useful information for the design evolution in the next desgin phase. - Abstract: Korean Helium Cooled Ceramic Reflector (HCCR) Test Blanket System (TBS) will be tested in ITER to demonstrate feasibility of the breeding blanket concept. The HCCR-TBS comprises Test Blanket Module (TBM) with associated shield, and ancillary systems located in various positions of ITER building. Currently, conceptual design for the HCCR-TBS is in progress. This paper presents pipe stress analysis results for the HCCR-TBS ancillary systems. The pipe stress analysis was performed in accordance with ASME B31.3 for major pipes of the Helium Cooling System (HCS) and the Coolant Purification System (CPS), which are operated in high pressure and temperature. The pipe stress for various load cases and load combinations were calculated. Operational pressure and temperature during plasma operation are applied as pressure load and thermal load, respectively. In addition seismic events were combined to investigate the code compliance for sustained load case and occasional load case. It was confirmed that the resultant stress meets the requirements of ASME B31.3 except one position in which it needs modification. These results give useful information for the next design phase, for example, nozzle loads for the component selection, the support design parameters, etc.

  11. A hybrid PSO technique for procuring VAR ancillary service in the deregulated electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    El-Araby, E.E. [Department of Electrical Engineering, Suez Canal University (Egypt); Yorino, Naoto [Department of Artificial Complex Systems Engineering, Hiroshima University (Japan)

    2010-07-15

    This paper develops a new market-based technique for acquiring VAR ancillary service in the electricity market. The main objective of the developed market is to enable transmission operator ''TO'' to procure VAR service in a long term contract from the critical VAR providers that satisfy minimum VAR service payment while maintaining system security. Reactive power control problem for voltage stability is introduced into the VAR market problem in an explicit manner for normal and emergency states. An integration of particle swarm optimization ''PSO'' is presented with successive linear programming ''SLP'' for dealing with the VAR ancillary service problem. The problem is formulated as a large-scale nonlinear constrained optimization problem with a non-differentiable objective function representing VAR payment and operational costs. This type of problem is hard to be treated straightforwardly by the classical optimization methods. Therefore, we propose here a two-layer hybrid PSO/SLP approach, which is suited for carrying out the difficulties associated with non-differentiable and discontinuous objective functions. The proposed method has been examined on the standard IEEE 57 bus-system and compared with GA/SLP method to demonstrate its capability. (author)

  12. Twist-3 effect from the longitudinally polarized proton for ALT in hadron production from pp collisions

    Directory of Open Access Journals (Sweden)

    Yuji Koike

    2016-08-01

    Full Text Available We compute the contribution from the longitudinally polarized proton to the twist-3 double-spin asymmetry ALT in inclusive (light hadron production from proton–proton collisions, i.e., p↑p→→hX. We show that using the relevant QCD equation-of-motion relation and Lorentz invariance relation allows one to eliminate the twist-3 quark-gluon correlator (associated with the longitudinally polarized proton in favor of one-variable twist-3 quark distributions and the (twist-2 transversity parton density. Including this result with the twist-3 pieces associated with the transversely polarized proton and unpolarized final-state hadron (which have already been calculated in the literature, we now have the complete leading-order cross section for this process.

  13. An improved hazard rate twisting approach for the statistic of the sum of subexponential variates

    KAUST Repository

    Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

    2015-01-01

    In this letter, we present an improved hazard rate twisting technique for the estimation of the probability that a sum of independent but not necessarily identically distributed subexponential Random Variables (RVs) exceeds a given threshold. Instead of twisting all the components in the summation, we propose to twist only the RVs which have the biggest impact on the right-tail of the sum distribution and keep the other RVs unchanged. A minmax approach is performed to determine the optimal twisting parameter which leads to an asymptotic optimality criterion. Moreover, we show through some selected simulation results that our proposed approach results in a variance reduction compared to the technique where all the components are twisted.

  14. Supersymmetric gauged double field theory: systematic derivation by virtue of twist

    International Nuclear Information System (INIS)

    Cho, Wonyoung; Fernández-Melgarejo, J.J.; Jeon, Imtak; Park, Jeong-Hyuck

    2015-01-01

    In a completely systematic and geometric way, we derive maximal and half-maximal supersymmetric gauged double field theories in lower than ten dimensions. To this end, we apply a simple twisting ansatz to the D=10 ungauged maximal and half-maximal supersymmetric double field theories constructed previously within the so-called semi-covariant formalism. The twisting ansatz may not satisfy the section condition. Nonetheless, all the features of the semi-covariant formalism, including its complete covariantizability, are still valid after the twist under alternative consistency conditions. The twist allows gaugings as supersymmetry preserving deformations of the D=10 untwisted theories after Scherk-Schwarz-type dimensional reductions. The maximal supersymmetric twist requires an extra condition to ensure both the Ramond-Ramond gauge symmetry and the 32 supersymmetries unbroken.

  15. The geometrical origin of the strain-twist coupling in double helices

    Directory of Open Access Journals (Sweden)

    Kasper Olsen

    2011-03-01

    Full Text Available A simple geometrical explanation for the counterintuitive phenomenon when twist leads to extension in double helices is presented. The coupling between strain and twist is investigated using a tubular description. It is shown that the relation between strain and rotation is universal and depends only on the pitch angle. For pitch angles below 39.4° strain leads to further winding, while for larger pitch angles strain leads to unwinding. The zero-twist structure, with a pitch angle of 39.4°, is at the unique point between winding and unwinding and independent of the mechanical properties of the double helix. The existence of zero-twist structures, i.e. structures that display neither winding, nor unwinding under strain is discussed. Close-packed double helices are shown to extend rather than shorten when twisted. Numerical estimates of this elongation upon winding are given for DNA, chromatin, and RNA.

  16. Gauging the twisted Poincare symmetry as a noncommutative theory of gravitation

    International Nuclear Information System (INIS)

    Chaichian, M.; Tureanu, A.; Oksanen, M.; Zet, G.

    2009-01-01

    Einstein's theory of general relativity was formulated as a gauge theory of Lorentz symmetry by Utiyama in 1956, while the Einstein-Cartan gravitational theory was formulated by Kibble in 1961 as the gauge theory of Poincare transformations. In this framework, we propose a formulation of the gravitational theory on canonical noncommutative space-time by covariantly gauging the twisted Poincare symmetry, in order to fulfil the requirement of covariance under the general coordinate transformations, an essential ingredient of the theory of general relativity. It appears that the twisted Poincare symmetry cannot be gauged by generalizing the Abelian twist to a covariant non-Abelian twist, nor by introducing a more general covariant twist element. The advantages of such a formulation as well as the related problems are discussed and possible ways out are outlined.

  17. QCD factorization of exclusive processes beyond leading twist: γT*→ρT impact factor with twist three accuracy

    International Nuclear Information System (INIS)

    Anikin, I.V.; Ivanov, D.Yu.; Pire, B.; Szymanowski, L.; Wallon, S.

    2010-01-01

    We describe a consistent approach to factorization of scattering amplitudes for exclusive processes beyond the leading twist approximation. The method involves the Taylor expansion of the scattering amplitude in the momentum space around the dominant light-cone direction and thus naturally introduces an appropriate set of non-perturbative correlators which encode effects not only of the lowest but also of the higher Fock states of the produced particle. The reduction of original set of correlators to a set of independent ones is achieved with the help of equations of motion and invariance of the scattering amplitude under rotation on the light cone. We compare the proposed method with the covariant method formulated in the coordinate space, based on the operator product expansion. We prove the equivalence of two proposed parametrizations of the ρ T distribution amplitudes. As a concrete application, we compute the expressions of the impact factor for the transition of virtual photon to transversally polarised ρ-meson up to the twist 3 accuracy within these two quite different methods and show that they are identical.

  18. Epigenetic inactivation of TWIST2 in acute lymphoblastic leukemia modulates proliferation, cell survival and chemosensitivity

    Science.gov (United States)

    Thathia, Shabnam H.; Ferguson, Stuart; Gautrey, Hannah E.; van Otterdijk, Sanne D.; Hili, Michela; Rand, Vikki; Moorman, Anthony V.; Meyer, Stefan; Brown, Robert; Strathdee, Gordon

    2012-01-01

    Background Altered regulation of many transcription factors has been shown to be important in the development of leukemia. TWIST2 modulates the activity of a number of important transcription factors and is known to be a regulator of hematopoietic differentiation. Here, we investigated the significance of epigenetic regulation of TWIST2 in the control of cell growth and survival and in response to cytotoxic agents in acute lymphoblastic leukemia. Design and Methods TWIST2 promoter methylation status was assessed quantitatively, by combined bisulfite and restriction analysis (COBRA) and pyrosequencing assays, in multiple types of leukemia and TWIST2 expression was determined by quantitative reverse transcriptase polymerase chain reaction analysis. The functional role of TWIST2 in cell proliferation, survival and response to chemotherapy was assessed in transient and stable expression systems. Results We found that TWIST2 was inactivated in more than 50% of cases of childhood and adult acute lymphoblastic leukemia through promoter hypermethylation and that this epigenetic regulation was especially prevalent in RUNX1-ETV6-driven cases. Re-expression of TWIST2 in cell lines resulted in a dramatic reduction in cell growth and induction of apoptosis in the Reh cell line. Furthermore, re-expression of TWIST2 resulted in increased sensitivity to the chemotherapeutic agents etoposide, daunorubicin and dexamethasone and TWIST2 hypermethylation was almost invariably found in relapsed adult acute lymphoblastic leukemia (91% of samples hypermethylated). Conclusions This study suggests a dual role for epigenetic inactivation of TWIST2 in acute lymphoblastic leukemia, initially through altering cell growth and survival properties and subsequently by increasing resistance to chemotherapy. PMID:22058208

  19. Optical yarn assessment system for twist measurement in rotor-spun yarn

    International Nuclear Information System (INIS)

    Jhatial, R.A.

    2015-01-01

    This paper presents the development of an optical yarn assessment system for evaluation of twist and structure of twisted yarn. The system comprises a yarn carriage unit, a video microscope and a personal computer. This system was used in conjunction with the well-known tracer fibre technique. This system enables digital images to be grabbed and continuous movies of the yarn to be recorded in order to facilitate the measurement of twist and the analysis of yarn structure. Yarn samples from polyester, viscose and cotton with 35 tex and 485 turns/meter were spun from the roving with 2.3% of black fibres on the SKF laboratory ring frame. In order to measure the twist in the rotor yarns with the optical yarn assessment system, a set of yarn samples from same fibres were spun on RU 14 rotor machine with 35 tex and 475 turns/meter. The twist was measured with the optical yarn assessment system and sixty tests of each sample were carried out on the Zweigle D301. It is clear from the results that there is consistency in the twist of ring-spun yarn measured by the optical yarn assessment system. However, the measured twist with the Zwiegle D301 is inconsistent in the different yarns. The difference in the mean twist measured with the optical twist measuring system and the double untwist-twist method was not significant at a 5% probability level when data was analyzed with t test by using SPSS (Statistical Package for Social Sciences). (author)

  20. Twist-1 Up-Regulation in Carcinoma Correlates to Poor Survival

    Directory of Open Access Journals (Sweden)

    Alimujiang Wushou

    2014-11-01

    Full Text Available Epithelial-to-mesenchymal transition (EMT facilitates tumor metastasis. Twist is a basic helix-loop-helix protein that modulates many target genes through E-box-responsive elements. There are two twist-like proteins, Twist-1 and Twist-2, sharing high structural homology in mammals. Twist-1 was found to be a key factor in the promotion of metastasis of cancer cells, and is known to induce EMT. Twist-1 participation in carcinoma progression and metastasis has been reported in a variety of tumors. However, controversy exists concerning the correlation between Twist-1 and prognostic value with respect to carcinoma. A systematic review and meta-analysis were performed to determine whether the expression of Twist-1 was associated with the prognosis of carcinoma patients. This analysis included 17 studies: four studies evaluated lung cancer, three evaluated head and neck cancer, two evaluated breast cancer, two evaluated esophageal cancer, two evaluated liver cancer and one each evaluated osteosarcoma, bladder, cervical and ovarian cancer. A total of 2006 patients were enrolled in these studies, and the median trial sample size was 118 patients. Twist-1 expression was associated with worse overall survival (OS at both 3 years (hazard ratio “HR” for death = 2.13, 95% CI = 1.86 to 2.45, p < 0.001 and 5 years (HR for death = 2.01, 95% CI = 1.76 to 2.29, p < 0.001. Expression of Twist-1 is associated with worse survival in carcinoma.

  1. An assessment of market and policy barriers for demand response providing ancillary services in U.S. electricity markets

    International Nuclear Information System (INIS)

    Cappers, Peter; MacDonald, Jason; Goldman, Charles; Ma, Ookie

    2013-01-01

    An impact of increased variable renewable generation is the need for balancing authorities to procure more ancillary services. While demand response resources are technically capable of providing these services, current experience across the U.S. illustrates they are relatively minor players in most regions. Accessing demand response resources for ancillary services may require a number of changes to policies and common practices at multiple levels. Regional reliability councils must first define ancillary services such that demand response resources may provide them. Once the opportunity exists, balancing authorities define and promulgate rules that set the infrastructure investments and performance attributes of a resource wishing to provide such services. These rules also dictate expected revenue streams which reveal the cost effectiveness of these resources. The regulatory compact between utility and state regulators, along with other statutes and decisions by state policymakers, may impact the interest of demand response program providers to pursue these resources as ancillary service providers. This paper identifies within these broad categories specific market and policy barriers to demand response providing ancillary services in different wholesale and retail environments, with emphasis on smaller customers who must be aggregated through a program provider to meet minimum size requirements for wholesale transactions. - Highlights: • We identify barriers keeping demand response from providing ancillary services. • Institutional, financial and program provider business model barriers exist. • Product definitions and rules do not always accommodate demand response well. • Expected revenues are uncertain and may not exceed required investments costs. • Regulatory compact and state statutes limit opportunities for program providers

  2. Take AIM and Keep Your Students Engaged

    Science.gov (United States)

    Nash, Catherine

    2014-01-01

    This paper outlines the benefits to distance education teachers of formatting a weekly online newsletter in accordance with motivational learning theory. It reflects on the delivery of weekly AIM newsletters to undergraduate economics students at the Open Polytechnic of New Zealand via Moodle. The acronym, AIM, stands for Academic content,…

  3. Discrimination and the aim of proportional representation

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2008-01-01

    Many organizations, companies, and so on are committed to certain representational aims as regards the composition of their workforce. One motivation for such aims is the assumption that numerical underrepresentation of groups manifests discrimination against them. In this article, I articulate r...

  4. Existence and equivalence of twisted products on a symplectic manifold

    International Nuclear Information System (INIS)

    Lichnerowicz, A.

    1979-01-01

    The twisted products play an important role in Quantum Mechanics. A distinction is introduced between Vey *sub(γ) products and strong Vey *sub(γ) products and it is proved that each *sub(γ) product is equivalent to a Vey *sub(γ) product. If b 3 (W) = 0, the symplectic manifold (W,F) admits strong Vey *sub(Gn) products. If b 2 (W) = 0, all *sub(γ) products are equivalent as well as the Vey Lie algebras. In the general case the formal Lie algebras are characterized which are generated by a *sub(γ) product and it proved that the existance of a *sub(γ)-product is equivalent to the existance of a formal Lie algebra infinitesimally equivalent to a Vey Lie algebra at the first order. (Auth.)

  5. The self-field effect in twisted superconducting composites

    International Nuclear Information System (INIS)

    Duchateau, J.L.; Turck, B.; Krempasky, L.; Polak, M.

    1976-01-01

    Since twisting of composites does not cause a transposition with respect to the self-field of the transport current, they behave like a bulk superconductor with averaged critical current density, when the transport current is changed. Consequently, the electric field is given by the history of the transport current changes. Using a simplified model (Jsub(c) = const) the expressions for the electric fields and losses for the first and immediately following second increase of the transport current are derived. Experimental results are also presented which clearly show higher electric field during the first run than during the following, which agrees with theoretical predictions. Quite a good quantitative agreement between theory and experiment was obtained up to about 80 % of the critical transport current. The influence of the copper matrix is also discussed. (author)

  6. Accelerating Twisted Mass LQCD with QPhiX

    Energy Technology Data Exchange (ETDEWEB)

    Schröck, Mario [INFN, Rome3; Simula, Silvano [INFN, Rome3; Strelchenko, Alexei [Fermilab

    2016-07-08

    We present the implementation of twisted mass fermion operators for the QPhiX library. We analyze the performance on the Intel Xeon Phi (Knights Corner) coprocessor as well as on Intel Xeon Haswell CPUs. In particular, we demonstrate that on the Xeon Phi 7120P the Dslash kernel is able to reach 80\\% of the theoretical peak bandwidth, while on a Xeon Haswell E5-2630 CPU our generated code for the Dslash operator with AVX2 instructions outperforms the corresponding implementation in the tmLQCD library by a factor of $\\sim 5\\times$ in single precision. We strong scale the code up to 6.8 (14.1) Tflops in single (half) precision on 64 Xeon Haswell CPUs.

  7. Threshold corrections and gauge symmetry in twisted superstring models

    International Nuclear Information System (INIS)

    Pierce, D.M.

    1994-01-01

    Threshold corrections to the running of gauge couplings are calculated for superstring models with free complex world sheet fermions. For two N=1 SU(2)xU(1) 5 models, the threshold corrections lead to a small increase in the unification scale. Examples are given to illustrate how a given particle spectrum can be described by models with different boundary conditions on the internal fermions. We also discuss how complex twisted fermions can enhance the symmetry group of an N=4, SU(3)xU(1)xU(1) model to the gauge group SU(3)xSU(2)xU(1). It is then shown how a mixing angle analogous to the Weinberg angle depends on the boundary conditions of the internal fermions

  8. DNA origami-based nanoribbons: assembly, length distribution, and twist

    Energy Technology Data Exchange (ETDEWEB)

    Jungmann, Ralf; Scheible, Max; Kuzyk, Anton; Pardatscher, Guenther; Simmel, Friedrich C [Lehrstuhl fuer Bioelektronik, Physik-Department and ZNN/WSI, Technische Universitaet Muenchen, Am Coulombwall 4a, 85748 Garching (Germany); Castro, Carlos E, E-mail: simmel@ph.tum.de [Labor fuer Biomolekulare Nanotechnologie, Physik-Department and ZNN/WSI, Technische Universitaet Muenchen, Am Coulombwall 4a, 85748 Garching (Germany)

    2011-07-08

    A variety of polymerization methods for the assembly of elongated nanoribbons from rectangular DNA origami structures are investigated. The most efficient method utilizes single-stranded DNA oligonucleotides to bridge an intermolecular scaffold seam between origami monomers. This approach allows the fabrication of origami ribbons with lengths of several micrometers, which can be used for long-range ordered arrangement of proteins. It is quantitatively shown that the length distribution of origami ribbons obtained with this technique follows the theoretical prediction for a simple linear polymerization reaction. The design of flat single layer origami structures with constant crossover spacing inevitably results in local underwinding of the DNA helix, which leads to a global twist of the origami structures that also translates to the nanoribbons.

  9. DNA origami-based nanoribbons: assembly, length distribution, and twist

    International Nuclear Information System (INIS)

    Jungmann, Ralf; Scheible, Max; Kuzyk, Anton; Pardatscher, Guenther; Simmel, Friedrich C; Castro, Carlos E

    2011-01-01

    A variety of polymerization methods for the assembly of elongated nanoribbons from rectangular DNA origami structures are investigated. The most efficient method utilizes single-stranded DNA oligonucleotides to bridge an intermolecular scaffold seam between origami monomers. This approach allows the fabrication of origami ribbons with lengths of several micrometers, which can be used for long-range ordered arrangement of proteins. It is quantitatively shown that the length distribution of origami ribbons obtained with this technique follows the theoretical prediction for a simple linear polymerization reaction. The design of flat single layer origami structures with constant crossover spacing inevitably results in local underwinding of the DNA helix, which leads to a global twist of the origami structures that also translates to the nanoribbons.

  10. Twisted quantum double model of topological order with boundaries

    Science.gov (United States)

    Bullivant, Alex; Hu, Yuting; Wan, Yidun

    2017-10-01

    We generalize the twisted quantum double model of topological orders in two dimensions to the case with boundaries by systematically constructing the boundary Hamiltonians. Given the bulk Hamiltonian defined by a gauge group G and a 3-cocycle in the third cohomology group of G over U (1 ) , a boundary Hamiltonian can be defined by a subgroup K of G and a 2-cochain in the second cochain group of K over U (1 ) . The consistency between the bulk and boundary Hamiltonians is dictated by what we call the Frobenius condition that constrains the 2-cochain given the 3-cocyle. We offer a closed-form formula computing the ground-state degeneracy of the model on a cylinder in terms of the input data only, which can be naturally generalized to surfaces with more boundaries. We also explicitly write down the ground-state wave function of the model on a disk also in terms of the input data only.

  11. New findings of twisted-wing parasites (Strepsiptera) in Alaska

    Science.gov (United States)

    Mcdermott, Molly

    2016-01-01

    Strepsipterans are a group of insects with a gruesome life history and an enigmatic evolutionary past. Called ‘twisted-wing parasites’, they are minute parasitoids with a very distinct morphology (Figure 1). Alternatively thought to be related to ichneumon wasps, Diptera (flies), Coleoptera (beetles), and even Neuroptera (net-winged insects) (Pohl and Beutel, 2013); the latest genetic and morphological data support the sister order relationship of Strepsiptera and Coleoptera (Niehuis et al., 2012). Strepsipterans are highly modified, males having two hind wings and halteres instead of front wings or elytra. Unlike most parasitoids, they develop inside active, living insects who are sexually sterilized but not killed until or after emergence (Kathirithamby et al., 2015).

  12. Topological susceptibility from the twisted mass Dirac operator spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, Krzysztof [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Garcia-Ramos, Elena [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Collaboration: European Twisted Mass Collaboration

    2013-12-15

    We present results of our computation of the topological susceptibility with N{sub f}=2 and N{sub f}= +1+1 flavours of maximally twisted mass fermions, using the method of spectral projectors. We perform a detailed study of the quark mass dependence and discretization effects. We make an attempt to confront our data with chiral perturbation theory and extract the chiral condensate from the quark mass dependence of the topological susceptibility. We compare the value with the results of our direct computation from the slope of the mode number. We emphasize the role of autocorrelations and the necessity of long Monte Carlo runs to obtain results with good precision. We also show our results for the spectral projector computation of the ratio of renormalization constants Z{sub P}/Z{sub S}.

  13. Localized topological states in Bragg multihelicoidal fibers with twist defects

    Science.gov (United States)

    Alexeyev, C. N.; Lapin, B. P.; Milione, G.; Yavorsky, M. A.

    2016-06-01

    We have studied the influence of a twist defect in multihelicoidal Bragg fibers on the emerging of localized defect modes. We have shown that if such a fiber is excited with a Gaussian beam this leads to the appearance of a defect-localized topological state, whose topological charge coincides with the order of rotational symmetry of the fiber's refractive index. We have shown that this effect has a pronounced crossover behavior. We have also formulated a principle of creating the systems that can nestle defect-localized topologically charged modes. According to this principle, such systems have to possess topological activity, that is, the ability to change the topological charge of the incoming field, and operate in the Bragg regime.

  14. Topological susceptibility from the twisted mass Dirac operator spectrum

    International Nuclear Information System (INIS)

    Cichy, Krzysztof; Jansen, Karl; Cyprus Univ., Nicosia

    2013-12-01

    We present results of our computation of the topological susceptibility with N f =2 and N f = +1+1 flavours of maximally twisted mass fermions, using the method of spectral projectors. We perform a detailed study of the quark mass dependence and discretization effects. We make an attempt to confront our data with chiral perturbation theory and extract the chiral condensate from the quark mass dependence of the topological susceptibility. We compare the value with the results of our direct computation from the slope of the mode number. We emphasize the role of autocorrelations and the necessity of long Monte Carlo runs to obtain results with good precision. We also show our results for the spectral projector computation of the ratio of renormalization constants Z P /Z S .

  15. Strong-field ionization with twisted laser pulses

    Science.gov (United States)

    Paufler, Willi; Böning, Birger; Fritzsche, Stephan

    2018-04-01

    We apply quantum trajectory Monte Carlo computations in order to model strong-field ionization of atoms by twisted Bessel pulses and calculate photoelectron momentum distributions (PEMD). Since Bessel beams can be considered as an infinite superposition of circularly polarized plane waves with the same helicity, whose wave vectors lie on a cone, we compared the PEMD of such Bessel pulses to those of a circularly polarized pulse. We focus on the momentum distributions in propagation direction of the pulse and show how these momentum distributions are affected by experimental accessible parameters, such as the opening angle of the beam or the impact parameter of the atom with regard to the beam axis. In particular, we show that we can find higher momenta of the photoelectrons, if the opening angle is increased.

  16. Nucleon and delta masses in twisted mass chiral perturbation theory

    International Nuclear Information System (INIS)

    Walker-Loud, Andre; Wu, Jackson M.S.

    2005-01-01

    We calculate the masses of the nucleons and deltas in twisted mass heavy baryon chiral perturbation theory. We work to quadratic order in a power counting scheme in which we treat the lattice spacing, a, and the quark masses, m q , to be of the same order. We give expressions for the mass and the mass splitting of the nucleons and deltas both in and away from the isospin limit. We give an argument using the chiral Lagrangian treatment that, in the strong isospin limit, the nucleons remain degenerate and the delta multiplet breaks into two degenerate pairs to all orders in chiral perturbation theory. We show that the mass splitting between the degenerate pairs of the deltas first appears at quadratic order in the lattice spacing. We discuss the subtleties in the effective chiral theory that arise from the inclusion of isospin breaking

  17. On the difficulty of computing higher-twist corrections

    International Nuclear Information System (INIS)

    Martinelli, G.; Sachrajda, C.T.

    1996-01-01

    We discuss the evaluation of power corrections to hard scattering and decay processes for which an operator product expansion is applicable. The Wilson coefficient of the leading-twist operator is the difference of two perturbative series, each of which has a renormalon ambiguity of the same order as the power corrections themselves, but which cancel in the difference. We stress the necessity of calculating this coefficient function to sufficiently high orders in perturbation theory so as to make the uncertainty of the same order of or smaller than the relevant power corrections. We investigate in some simple examples whether this can be achieved. Our conclusion is that in most of the theoretical calculations which include power corrections, the uncertainties are at least comparable to the power corrections themselves, and that it will be a very difficult task to improve the situation. (orig.)

  18. Nanofibrous Smart Fabrics from Twisted Yarns of Electrospun Piezopolymer.

    Science.gov (United States)

    Yang, Enlong; Xu, Zhe; Chur, Lucas K; Behroozfar, Ali; Baniasadi, Mahmoud; Moreno, Salvador; Huang, Jiacheng; Gilligan, Jules; Minary-Jolandan, Majid

    2017-07-19

    Smart textiles are envisioned to make a paradigm shift in wearable technologies to directly impart functionality into the fibers rather than integrating sensors and electronics onto conformal substrates or skin in wearable devices. Among smart materials, piezoelectric fabrics have not been widely reported, yet. Piezoelectric smart fabrics can be used for mechanical energy harvesting, for thermal energy harvesting through the pyroelectric effect, for ferroelectric applications, as pressure and force sensors, for motion detection, and for ultrasonic sensing. We report on mechanical and material properties of the plied nanofibrous piezoelectric yarns as a function of postprocessing conditions including thermal annealing and drawing (stretching). In addition, we used a continuous electrospinning setup to directly produce P(VDF-TrFE) nanofibers and convert them into twisted plied yarns, and demonstrated application of these plied yarns in woven piezoelectric fabrics. The results of this work can be an early step toward realization of piezoelectric smart fabrics.

  19. Flicker in a twisted nematic spatial light modulator

    Science.gov (United States)

    Calderón-Hermosillo, Yuliana; García-Márquez, Jorge; Espinosa-Luna, Rafael; Ochoa, Noé Alcalá; López, Víctor; Aguilar, Alberto; Noé-Arias, Enrique; Alayli, Yasser

    2013-06-01

    Liquid Crystal on Silicon (LCoS) Spatial Light Modulators (SLM) are widely used for their capability to control beams howbeit fluctuations in phase and amplitude. It is then necessary to understand the negative effects of these fluctuations, also known as flicker, and the means to mitigate them. The flicker is observed either as high frequency variations of polarization, attenuation or high phase fluctuations on the wave front modulated by the LCoS device. Here, we compare the flicker behavior in a twisted nematic (TN) LCoS-SLM for different polarization schemes and temperatures. The quantitative evaluation shows that flicker is effectively reduced only by chilling the LCoS panel to temperatures just below 0 °C but, the LCoS modulation capability is also affected.

  20. Nonlinear and hysteretic twisting effects in ocean cable laying

    International Nuclear Information System (INIS)

    Shashaty, A.J.

    1983-01-01

    Armored ocean cable unlays under the action of installation tensions and restraining moments applied by the ocean bottom and the ship's bow sheave. The process of elongation and twist is nonlinear and hysteretic. This process has often been assumed linear and reversible. The equations describing the moment which is developed in laying cable on the ocean bottom are worked out, without assuming linearity and reversibility. These equations are applied to some cases likely to arise. For a typical armored coaxial cable laid in 3700m (2,000 fathoms) depth without bottom tension, a steady-state laying-up moment of 134Nm (99 lbs. ft.) is developed. For the reversible case, no moment is developed. If the bottom tension is increased from zero to 33,375N (7500 lbs.) and then returned to zero, a peak moment of 198Nm (146 lbs. ft.) is developed

  1. Effective electrical and thermal conductivity of multifilament twisted superconductors

    International Nuclear Information System (INIS)

    Chechetkin, V.R.

    2013-01-01

    The effective electrical and thermal conductivity of composite wire with twisted superconducting filaments embedded into normal metal matrix is calculated using the extension of Bruggeman method. The resistive conductivity of superconducting filaments is described in terms of symmetric tensor, whereas the conductivity of a matrix is assumed to be isotropic and homogeneous. The dependence of the resistive electrical conductivity of superconducting filaments on temperature, magnetic field, and current density is implied to be parametric. The resulting effective conductivity tensor proved to be non-diagonal and symmetric. The non-diagonal transverse–longitudinal components of effective electrical conductivity tensor are responsible for the redistribution of current between filaments. In the limits of high and low electrical conductivity of filaments the transverse effective conductivity tends to that of obtained previously by Carr. The effective thermal conductivity of composite wires is non-diagonal and radius-dependent even for the isotropic and homogeneous thermal conductivities of matrix and filaments.

  2. Utilization of Ancillary Data Sets for Conceptual SMAP Mission Algorithm Development and Product Generation

    Science.gov (United States)

    O'Neill, P.; Podest, E.

    2011-01-01

    The planned Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond [1]. Scheduled to launch late in 2014, the proposed SMAP mission would provide high resolution and frequent revisit global mapping of soil moisture and freeze/thaw state, utilizing enhanced Radio Frequency Interference (RFI) mitigation approaches to collect new measurements of the hydrological condition of the Earth's surface. The SMAP instrument design incorporates an L-band radar (3 km) and an L band radiometer (40 km) sharing a single 6-meter rotating mesh antenna to provide measurements of soil moisture and landscape freeze/thaw state [2]. These observations would (1) improve our understanding of linkages between the Earth's water, energy, and carbon cycles, (2) benefit many application areas including numerical weather and climate prediction, flood and drought monitoring, agricultural productivity, human health, and national security, (3) help to address priority questions on climate change, and (4) potentially provide continuity with brightness temperature and soil moisture measurements from ESA's SMOS (Soil Moisture Ocean Salinity) and NASA's Aquarius missions. In the planned SMAP mission prelaunch time frame, baseline algorithms are being developed for generating (1) soil moisture products both from radiometer measurements on a 36 km grid and from combined radar/radiometer measurements on a 9 km grid, and (2) freeze/thaw products from radar measurements on a 3 km grid. These retrieval algorithms need a variety of global ancillary data, both static and dynamic, to run the retrieval models, constrain the retrievals, and provide flags for indicating retrieval quality. The choice of which ancillary dataset to use for a particular SMAP product would be based on a number of factors

  3. Gaussian tunneling model of c-axis twist Josephson junctions

    International Nuclear Information System (INIS)

    Bille, A.; Klemm, R.A.; Scharnberg, K.

    2001-01-01

    We calculate the critical current density J c J ((var p hi) 0 ) for Josephson tunneling between identical high-temperature superconductors twisted an angle (var p hi) 0 about the c axis. Regardless of the shape of the two-dimensional Fermi surface and for very general tunneling matrix elements, an order parameter (OP) with general d-wave symmetry leads to J c J (π/4)=0. This general result is inconsistent with the data of Li et al. [Phys. Rev. Lett. 83, 4160 (1999)] on Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212), which showed J c J to be independent of (var p hi) 0 . If the momentum parallel to the barrier is conserved in the tunneling process, J c J should vary substantially with the twist angle (var p hi) 0 when the tight-binding Fermi surface appropriate for Bi2212 is taken into account, even if the OP is completely isotropic. We quantify the degree of momentum nonconservation necessary to render J c J ((var p hi) 0 ) constant within experimental error for a variety of pair states by interpolating between the coherent and incoherent limits using five specific models to describe the momentum dependence of the tunneling matrix element squared. From the data of Li et al., we conclude that the c-axis tunneling in Bi2212 must be very nearly incoherent, and that the OP must have a nonvanishing Fermi-surface average for T c . We further show that the apparent conventional sum-rule violation observed by Basov et al. [Science 283, 49 (1999)] can be consistent with such strongly incoherent c-axis tunneling.

  4. Study of Implosion of Twisted Nested Arrays at the Angara-5-1 Facility

    Science.gov (United States)

    Mitrofanov, K. N.; Zukakishvili, G. G.; Aleksandrov, V. V.; Grabovski, E. V.; Frolov, I. N.; Gribov, A. N.

    2018-01-01

    Results are presented from experimental studies of the implosion of twisted nested arrays in which the wires of the outer and inner arrays are twisted about the array axis in opposite directions (clockwise and counterclockwise). Experiments with twisted arrays were carried out at the Angara-5-1 facility at currents of up to 4 MA. The currents through the arrays were switched either simultaneously or the current pulse through the outer array was delayed by 10-15 ns with the help of an anode spark gap. It is shown that, in such arrays, the currents flow along the inclined wires and, accordingly, there are both the azimuthal and axial components of the discharge current. The process of plasma implosion in twisted arrays depends substantially on the value of the axial (longitudinal) magnetic field generated inside the array by the azimuthal currents. Two-dimensional simulations of the magnetic field in twisted nested arrays were performed in the ( r, z) geometry with allowance for the skin effect in the discharge electrodes. It is shown that, depending on the geometry of the discharge electrodes, different configurations of the magnetic field can be implemented inside twisted nested arrays. The calculated magnetic configurations are compared with the results of measurements of the magnetic field inside such arrays. It is shown that the configuration of the axial magnetic field inside a twisted nested array depends substantially on the distribution of the azimuthal currents between the inner and outer arrays.

  5. Twist and snai1 expression in pharyngeal squamous cell carcinoma stroma is related to cancer progression

    International Nuclear Information System (INIS)

    Jouppila-Mättö, Anna; Närkiö-Mäkelä, Mervi; Soini, Ylermi; Pukkila, Matti; Sironen, Reijo; Tuhkanen, Hanna; Mannermaa, Arto; Kosma, Veli-Matti

    2011-01-01

    Epithelial-mesenchymal transition (EMT) is a crucial process in tumorigenesis since tumor cells attain fibroblast-like features enabling them to invade to surrounding tissue. Two transcription factors, TWIST and SNAI1, are fundamental in regulating EMT. Immunohistochemistry was used to study the expression of TWIST and SNAI1 in 109 pharyngeal squamous cell carcinomas. Tumors with intense stromal staining of TWIST relapsed more frequently (p = 0.04). Tumors with both positive TWIST and SNAI1 immunoreactivity in the stroma were at least Stage II (p = 0.05) and located more often in hypopharynx (p = 0.035). Tumors with negative immunostaining of TWIST and SNAI1 in the stromal compartment were smaller (T1-2) (p = 0.008), less advanced (SI-II) (p = 0.031) and located more often in the oropharynx (p = 0.007). Patients with negative SNAI1 and TWIST immunostaining in tumor stroma had a better 5-year disease-specific and overall survival (p = 0.037 and p = 0.014 respectively). TWIST and SNAI1 expression in stromal cells is associated with clinical and histopathological characteristics that indicate progressive disease. Negative expression of these EMT-promoting transcription factors predicts a better outcome

  6. Continuous Static Gait with Twisting Trunk of a Metamorphic Quadruped Robot

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2018-01-01

    Full Text Available The natural quadrupeds, such as geckos and lizards, often twist their trunks when moving. Conventional quadruped robots cannot perform the same motion due to equipping with a trunk which is a rigid body or at most consists of two blocks connected by passive joints. This paper proposes a metamorphic quadruped robot with a reconfigurable trunk which can implement active trunk motions, called MetaRobot I. The robot can imitate the natural quadrupeds to execute motion of trunk twisting. Benefiting from the twisting trunk, the stride length of this quadruped is increased comparing to that of conventional quadruped robots.In this paper a continuous static gait benefited from the twisting trunk performing the increased stride length is introduced. After that, the increased stride length relative to the trunk twisting will be analysed mathematically. Other points impacting the implementation of the increased stride length in the gait are investigated such as the upper limit of the stride length and the kinematic margin. The increased stride length in the gait will lead the increase of locomotion speed comparing with conventional quadruped robots, giving the extent that natural quadrupeds twisting their trunks when moving. The simulation and an experiment on the prototype are then carried out to illustrate the benefits on the stride length and locomotion speed brought by the twisting trunk to the quadruped robot.

  7. Discrimination and the aim of proportional representation

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2008-01-01

    Many organizations, companies, and so on are committed to certain representational aims as regards the composition of their workforce. One motivation for such aims is the assumption that numerical underrepresentation of groups manifests discrimination against them. In this article, I articulate...... representational aims in a way that best captures this rationale. My main claim is that the achievement of such representational aims is reducible to the elimination of the effects of wrongful discrimination on individuals and that this very important concern is, in principle, compatible with the representation...... of discrimination against numerically overrepresented groups, or overlook the innocently different ambitions of some numerically underrepresented groups. In relation to the latter point, I appeal to the fact that many luck egalitarians think justice should be ambition sensitive (but endowment insensitive). Also...

  8. AIM: An Integrated Approach to Organizational Improvement

    Directory of Open Access Journals (Sweden)

    Ronald A. Styron, Jr.

    2016-02-01

    Full Text Available This concept paper is based on the new problem-solving model of Blended Leadership called Alloy Improvement Model (AIM. This model consists of an integration of change theory, leadership theory, and democratic principles and practices to form a comprehensive problem-solving strategy for organizational leaders. The utilization of AIM will assist leaders in moving from problems to solutions while engaging stakeholders in a comprehensive, efficient, inclusive, informative, integrated and transparent process.

  9. Higher-twist effects in the B → π transition form factor from QCD light-cone sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Khodjamirian, Alexander; Rusov, Aleksey [Universitaet Siegen (Germany). Fakultaet IV, Department Physik, Theoretische Physik 1 Walter-Flex-Strasse 3 57068 Siegen

    2016-07-01

    I report on the progress in calculating new higher-twist corrections to the QCD light-cone sum rule for the B → π transition form factor. First, the expansion of the massive heavy-quark propagator in the external gluonic field near the light-cone was extended to include new terms containing the gluon-field strength derivatives. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function were obtained in a factorized approximation, expressed via the product of the quark-condensate density and the lower-twist pion distribution amplitudes. The numerical analysis of new higher-twist effects is in progress.

  10. Disassembly of JT-60 tokamak device and ancillary facilities for JT-60 tokamak

    International Nuclear Information System (INIS)

    Okano, Fuminori; Ichige, Hisashi; Miyo, Yasuhiko; Kaminaga, Atsushi; Sasajima, Tadayuki; Nishiyama, Tomokazu; Yagyu, Jun-ichi; Ishige, Youichi; Suzuki, Hiroaki; Komuro, Kenichi; Sakasai, Akira; Ikeda, Yoshitaka

    2014-03-01

    The disassembly of JT-60 tokamak device and its peripheral equipments, where the total weight was about 5400 tons, started in 2009 and accomplished in October 2012. This disassembly was required process for JT-60SA project, which is the Satellite Tokamak project under Japan-EU international corroboration to modify the JT-60 to the superconducting tokamak. This work was the first experience of disassembling a large radioactive fusion device based on Radiation Hazard Prevention Act in Japan. The cutting was one of the main problems in this disassembly, such as to cut the welded parts together with toroidal field coils, and to cut the vacuum vessel into two. After solving these problems, the disassembly completed without disaster and accident. This report presents the outline of the JT-60 disassembly, especially tokamak device and ancillary facilities for tokamak device. (author)

  11. Ancillary testing, diagnostic/classification criteria and severity grading in Behçet disease.

    Science.gov (United States)

    Okada, Annabelle A; Stanford, Miles; Tabbara, Khalid

    2012-12-01

    Since there is no pathognomonic clinical sign or laboratory test to distinguish Behçet disease from other uveitic entities, the diagnosis must be made based on characteristic ocular and systemic findings in the absence of evidence of other disease that can explain the findings. Ancillary tests, including ocular and brain imaging studies, are used to assess the severity of intraocular inflammation and systemic manifestations of Behçet disease, to identify latent infections and other medical conditions that might worsen with systemic treatment, and to monitor for adverse effects of drugs used. There are two diagnostic or classification criteria in general use by the uveitis community, one from Japan and one from an international group; both rely on a minimum number and/or combination of clinical findings to identify Behçet disease. Finally, several grading schemes have been proposed to assess severity of ocular disease and response to treatment.

  12. Estimating commercial property prices: an application of cokriging with housing prices as ancillary information

    Science.gov (United States)

    Montero-Lorenzo, José-María; Larraz-Iribas, Beatriz; Páez, Antonio

    2009-12-01

    A vast majority of the recent literature on spatial hedonic analysis has been concerned with residential property values, with only very few examples of studies focused on commercial property prices. The dearth of studies can be attributed to some of the challenges faced in the analysis of commercial properties, in particular the scarcity of information compared to residential transactions. In order to address this issue, in this paper we propose the use of cokriging and housing prices as ancillary information to estimate commercial property prices. Cokriging takes into account the spatial autocorrelation structure of property prices, and the use of more abundant information on housing prices helps to improve the accuracy of property value estimates. A case study of Toledo in Spain, a city for which commercial activity stemming from tourism is one of the key elements of the economy in the city, demonstrates that substantial accuracy and precision gains can be obtained from the use of cokriging.

  13. Critical Joints in Large Composite Primary Aircraft Structures. Volume 3: Ancillary Test Results

    Science.gov (United States)

    Bunin, Bruce L.; Sagui, R. L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints for composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of a comprehensive ancillary test program are summarized, consisting of single-bolt composite joint specimens tested in a variety of configurations. These tests were conducted to characterize the strength and load deflection properties that are required for multirow joint analysis. The composite material was Toray 300 fiber and Ciba-Geigy 914 resin, in the form of 0.005 and 0.01 inch thick unidirectional tape. Tests were conducted in single and double shear for loaded and unloaded hole configurations under both tensile and compressive loading. Two different layup patterns were examined. All tests were conducted at room temperature. In addition, the results of NASA Standard Toughness Test (NASA RP 1092) are reported, which were conducted for several material systems.

  14. Ancillary services and the integration of substantial quantities of wind power

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2006-01-01

    . Ballerup: Elkraft System; 2004]. At the same time, Denmark has other forms of distributed generation, e.g., extensive cogeneration of heat and power (CHP) plants for district heating or for covering industrial heat demands. This results in a high fuel-efficiency but also in a technically complex energy......Denmark has the World’s highest penetration of grid connected wind power in electricity generation with a share of 15.0% of total domestic demand in 2002 [Danish Energy Authority. Rapport fra arbejdsgruppen om kraftvarme- og VE-elektricitet. Bilagsrapport. Copenhagen: Danish Energy Authority; 2001...... as the potential impact of heat pumps used for district heating and installed for integration purposes. The analyses are made with particular focus on grid stability and delivery of ancillary services (required to control voltage and frequency) and demonstrate that it is possible to accommodate 50% or more wind...

  15. System design specification for the 1/4-scale tank and ancillary equipment

    International Nuclear Information System (INIS)

    Bamberger, J.A.; Bates, J.M.; Waters, E.D.; Heimberger, D.T.

    1993-09-01

    The Fluid Dynamic Test Facility (FDTF) is located in the 336 Building at the 300 Area of the Hanford Site. The FDTF will contain tanks that model the average internal diameter and height of a 3875 m 3 (1-million-gal) double-shell tank at both 1/12- and 1/4-scale, as well as ancillary equipment required to store, mix, and transport waste simulants. Experiments to be conducted in this facility will include investigations of sludge mobilization, slurry uniformity, aerosol generation, sludge washing, and instrumentation development to support start-up of the Hanford Waste Vitrification Project. This facility will also be used to model concepts and mitigating strategies to be used in the resolution of tank safety issues and the retrieval of waste from watch-list tanks

  16. Status of the segment interconnect, cable segment ancillary logic, and the cable segment hybrid driver projects

    International Nuclear Information System (INIS)

    Swoboda, C.; Barsotti, E.; Chappa, S.; Downing, R.; Goeransson, G.; Lensy, D.; Moore, G.; Rotolo, C.; Urish, J.

    1985-01-01

    The FASTBUS Segment Interconnect (SI) provides a communication path between two otherwise independent, asynchronous bus segments. In particular, the Segment Interconnect links a backplane crate segment to a cable segment. All standard FASTBUS address and data transactions can be passed through the SI or any number of SIs and segments in a path. Thus systems of arbitrary connection complexity can be formed, allowing simultaneous independent processing, yet still permitting devices associated with one segment to be accessed from others. The model S1 Segment Interconnect and the Cable Segment Ancillary Logic covered in this report comply with all the mandatory features stated in the FASTBUS specification document DOE/ER-0189. A block diagram of the SI is shown

  17. Engineering Evaluation/Cost Analysis for the 100-N Area Ancillary Facilities and Integration Plan

    International Nuclear Information System (INIS)

    Mukherjee, B.

    1997-09-01

    This document presents the results of an engineering evaluation/cost analysis (EE/CA) that was conducted to evaluate alternatives for addressing final disposition of contaminated buildings and structures in the 100-N Area of the Hanford Site. The Hanford Site is located in southeastern Washington State and is owned by the U.S. Government and operated by the U.S. Department of Energy, Richland Operations Office (RL). In November 1989, the 100 Area of the Hanford Site (as well as the 200, 300, and 1100 Areas) was placed on the U.S. Environmental Protection Agency's National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. The 100 Area NPL includes the 100-N Area, which is in various stages of the remediation process. It has been determined by RL that hazardous substances in the 100-N Area ancillary facilities may present a potential threat to human health or the environment, and that a non-time critical removal action at these facilities is warranted. To help determine the most appropriate action, RL, in cooperation with the Washington State Department of Ecology (Ecology) and the EPA, has prepared this EE/CA. The scope of the evaluation includes the inactive contaminated ancillary facilities in the 100-N Area, the facilities residing in the buffer zone, and the Hanford Generating Plant (HGP) and the solid waste management units (SWMUs) inside HGP support facilities. The 105-N Reactor and 109-N Heat Exchange facilities are excluded from this EE/CA evaluation

  18. Development of modified rational buyer auction for procurement of ancillary services utilizing participation matrix

    International Nuclear Information System (INIS)

    Jamalzadeh, R.; Ardehali, M.M.; Rashidinejad, M.

    2008-01-01

    The rational buyer auction is based on a simultaneous auction that is the redesigned auction mechanism for ancillary services by the California independent system operator (CAISO). The incentive for the rational buyer auction is CAISO's intent to adopt a common sense rule of substituting higher-quality lower-cost services for lower-quality higher-cost services, when it results in reduced total procurement cost. For the purposes of designing a desirable auction where the minimum cost for the objective function as well as prevention of price reversal are achieved, either the payment cost in marginal pricing auction must be lowered or price reversal in rational buyer auction must be avoided. The objectives of this study are (a) to develop a newly proposed 'modified rational buyer' auction that does not allow price reversal and (b) to propose and validate a solution procedure that is based on participation matrix and discrete programming. The validation of the proposed solution procedure is accomplished through examination of two case studies available in the literature. Based on the first case study data, it is shown that the newly developed modified rational buyer auction avoids price reversal occurrence, while the total payment of ISO is increased by 5.8%, as compared with rational buyer auction. Also in comparison with marginal pricing auction, the ISO payment is lowered by 38.8%, when the newly developed modified rational buyer auction is utilized. For future work, it is recommended that the application of the modified rational buyer auction to joint dispatch of energy and ancillary services is investigated

  19. Radiative capture of cold neutrons by protons and deuteron photodisintegration with twisted beams

    Science.gov (United States)

    Afanasev, Andrei; Serbo, Valeriy G.; Solyanik, Maria

    2018-05-01

    We consider two basic nuclear reactions: capture of neutrons by protons, n + p → γ + d, and its time-reversed counterpart, photodisintegration of the deuteron, γ + d → n + p. In both of these cases we assume that the incoming beam of neutrons or photons is ‘twisted’ by having an azimuthal phase dependence, i.e., it carries an additional angular momentum along its direction of propagation. Taking a low-energy limit of these reactions, we derive relations between corresponding transition amplitudes and cross sections with plane-wave beams and twisted beams. Implications for experiments with twisted cold neutrons and twisted photon beams are discussed.

  20. Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

    Science.gov (United States)

    Budinski, Vedran; Donlagic, Denis

    2017-01-01

    Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation. PMID:28241510