Mendel Horwitz, Roberto Ruben
1982-03-01
In the framework of the Glashow-Weinberg-Salem model without elementary scalar particles, we show that masses for fermions and intermediate vector bosons can be generated dynamically. The mechanism is the formation of fermion-antifermion pseudoscalar bound states of zero total four momentum, which form a condensate in the physical vacuum. The force responsible for the binding is the short distance part of the net Coulomb force due to photon and Z exchange. Fermions and bosons acquire masses through their interaction with this condensate. The neutrinos remain massless because their righthanded components have no interactions. Also the charge -1/3 quarks remain massless because the repulsive force from the Z exchange dominates over the Coulomb force. To correct this, we propose two possible modifications to the theory. One is to cut off the Z exchange at very small distances, so that all fermions except the neutrinos acquire masses, which are then, purely electromagnetic in origin. The other is to introduce an additional gauge boson that couples to all quarks with a pure vector coupling. To make this vector boson unobservable at usual energies, at least two new fermions must couple to it. The vector boson squared masses receive additive contributions from all the fermion squared masses. The photon remains massless and the masses of the Z and W('(+OR -)) bosons are shown to be related through the Weinberg angle in the conventional way. Assuming only three families of fermions, we obtain estimates for the top quark mass.
Dynamical mass generation in QED with weak magnetic fields
International Nuclear Information System (INIS)
Ayala, A.; Rojas, E.; Bashir, A.; Raya, A.
2006-01-01
We study the dynamical generation of masses for fundamental fermions in quenched quantum electrodynamics in the presence of magnetic fields using Schwinger-Dyson equations. We show that, contrary to the case where the magnetic field is strong, in the weak field limit eB << m(0)2, where m(0) is the value of the dynamically generated mass in the absence of the magnetic field, masses are generated above a critical value of the coupling and that this value is the same as in the case with no magnetic field. We carry out a numerical analysis to study the magnetic field dependence of the mass function above critical coupling and show that in this regime the dynamically generated mass and the chiral condensate for the lowest Landau level increase proportionally to (eB)2
Technicolor and the asymptotic behavior of dynamically generated masses
International Nuclear Information System (INIS)
Natale, A.A.
1984-01-01
Arguments are given in favor of a hard asymptotic behavior of dynamically generated masses, its consequences for technicolor models are analyzed and a model is proposed, where effects of flavor changing neutral currents are highly supressed and pseudo Goldstone bosons get masses of O(30-90) GeV. (Author) [pt
Role of centre vortices in dynamical mass generation
International Nuclear Information System (INIS)
Leinweber, Derek B.; Bowman, Patrick O.; Heller, Urs M.; Kusterer, Daniel-Jens; Langfeld, Kurt; Williams, Anthony G.
2006-01-01
The mass and renormalization functions of the nonperturbative quark propagator are studied in SU(3) gauge field theory with a Symanzik-improved gluon action and the AsqTad fermion action. Centre vortices in the gauge field are identified by fixing to maximal centre gauge. The role of centre vortices in dynamical mass generation is explored by removing centre vortices from the gauge fields and studying the associated changes in the quark propagator. We find that dynamical mass generation survives in the vortex-removed SU(3) gauge field theory despite the vanishing of the string tension and suppression of the gluon propagator in the infrared suggesting the possibility of decoupling dynamical mass generation from confinement
Constraining dynamical neutrino mass generation with cosmological data
Energy Technology Data Exchange (ETDEWEB)
Koksbang, S.M.; Hannestad, S., E-mail: koksbang@phys.au.dk, E-mail: sth@phys.au.dk [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)
2017-09-01
We study models in which neutrino masses are generated dynamically at cosmologically late times. Our study is purely phenomenological and parameterized in terms of three effective parameters characterizing the redshift of mass generation, the width of the transition region, and the present day neutrino mass. We also study the possibility that neutrinos become strongly self-interacting at the time where the mass is generated. We find that in a number of cases, models with large present day neutrino masses are allowed by current CMB, BAO and supernova data. The increase in the allowed mass range makes it possible that a non-zero neutrino mass could be measured in direct detection experiments such as KATRIN. Intriguingly we also find that there are allowed models in which neutrinos become strongly self-interacting around the epoch of recombination.
Dynamic mass generation and renormalizations in quantum field theories
International Nuclear Information System (INIS)
Miransky, V.A.
1979-01-01
It is shown that the dynamic mass generation can destroy the multiplicative renormalization relations and lead to new type divergences in the massive phase. To remove these divergences the values of the bare coupling constants must be fixed. The phase diagrams of gauge theories are discussed
Dynamical mass generation in the continuum Thirring model
International Nuclear Information System (INIS)
Girardello, L.; Immirzi, G.; Rossi, P.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge
1982-01-01
We study the renormalization of the Thirring model in the neighbourhood of μ = 0,g = -π/2, and find that on the trajectory which tends to this point when the scale goes to infinity the behaviour of the model reproduces what one obtains decomposing the N = 2 Gross-Neveu model. The existence of this trajectory is consistent with the dynamical mass generation found by McCoy and Wu in the discrete version of the massless model. (orig.)
Fermion flavor mixing in models with dynamical mass generation
Czech Academy of Sciences Publication Activity Database
Beneš, Petr
2010-01-01
Roč. 81, č. 6 (2010), 065029/1-065029/13 ISSN 1550-7998 Institutional research plan: CEZ:AV0Z10480505 Keywords : weak interactions * particle physics * neutrino masses Subject RIV: BE - Theoretical Physics Impact factor: 4.964, year: 2010
Dynamical mechanism of symmetry breaking and particle mass generation in gauge field theories
International Nuclear Information System (INIS)
Miranskij, V.A.; Fomin, P.I.
1985-01-01
The dynamics of the spotaneous symmetry breaking and the particle mass generation in gauge theories with no fundamental scalar fields is considered. The emphasis is on the consideration of the symmetry breaking mechanism connected with the dynamics of the supercritical Coulomb-like forces caused by the gauge boson exchange between fermions. This mechanism is applied to different gauge theories, in particular, to the description of the spontaneous chira symmetry breaking in quantum chromodynamics. The mass relations for pseudoscalar meson nonet are obtained and it is shown that this mechanism resuls in the dynamical realisation of the hypothesis of the partial conservation of the axial-vector currents. The qualitative description of scalar mesons is given. The nature of the ultraviolet divergencies in quantum electrodynamics (QED) is investigated from the viewpoint of the dynamics of the fermion mass generation. The mechanism of the appearance of the additional (in comparison with perturbation theory) ultraviolet divergencies in QED with large bare coupling constant is indicated. The physical phenomenon underlying this mechanism is identified as the field theory analogue of the quantum mechanical ''fall into the centre'' (collapse) phenomenon. The similr phenomenon is shown to take place in some two-dimensional quantum field models. The dynamics of the bifermion condensates formation in tumblin gauge theories is briefly discussed
Dynamical Mass Generation and Confinement in Maxwell-Chern-Simons Planar Quantum Electrodynamics
International Nuclear Information System (INIS)
Sanchez Madrigal, S; Raya, A; Hofmann, C P
2011-01-01
We study the non-perturbative phenomena of Dynamical Mass Generation and Confinement by truncating at the non-perturbative level the Schwinger-Dyson equations in Maxwell-Chern-Simons planar quantum electrodynamics. We obtain numerical solutions for the fermion propagator in Landau gauge within the so-called rainbow approximation. A comparison with the ordinary theory without the Chern-Simons term is presented.
Energy Technology Data Exchange (ETDEWEB)
McDougall, N.A. (Oxford Univ. (UK). Dept. of Theoretical Physics)
1983-01-10
When dynamical mass generation resulting from the breakdown of chiral symmetry is taken into account, instanton dynamics treated within the dilute gas approximation may satisfy the constraints on the quark condensates and the topological charge correlation function derived by Crewther from an analysis of the chiral Ward identities assuming the absence of a physical axial U(1) Goldstone boson. From a consideration of the contribution of the eta' to the topological charge correlation function, a relationship is derived in which msub(eta')/sup 2/fsub(eta')/sup 2/ is proportional to the vacuum energy density.
International Nuclear Information System (INIS)
McDougall, N.A.
1983-01-01
When dynamical mass generation resulting from the breakdown of chiral symmetry is taken into account, instanton dynamics treated within the dilute gas approximation may satisfy the constraints on the quark condensates and the topological charge correlation function derived by Crewther from an analysis of the chiral Ward identities assuming the absence of a physical axial U(1) Goldstone boson. From a consideration of the contribution of the eta' to the topological charge correlation function, a relationship is derived in which msub(eta') 2 fsub(eta') 2 is proportional to the vacuum energy density. (orig.)
On the dynamical mass generation in gauge-invariant non-linear σ-models
International Nuclear Information System (INIS)
Diaz, A.; Helayel-Neto, J.A.; Smith, A.W.
1987-12-01
We argue that external gauge fields coupled in a gauge-invariant way to both the bosonic and supersymmetric two-dimensional non-linear σ-models acquire a dynamical mass term whenever the target space is restricted to be a group manifold. (author). 11 refs
Chernyuk, Artem Mikhaylovich; Egorov, Оleksii Borisovich; Budanov, Pavlo Feofanovch; Bykova, Viktoriya Sergeyevna
2015-01-01
The analysis of methods of decline of mass and size indexes of synchronous generators and increase of their tecnik and economic descriptions is conducted in the article. Possible changes are certain in the modes of operations of machine as a result of change of its массо-габаритных indexes. Dependence of dynamic stability of work of machine as function of moment of inertia of its rotor is shown. Descriptions of speed of change of corner of ä of synchronous generator are got depending on the m...
Mass generation in composite models
International Nuclear Information System (INIS)
Peccei, R.D.
1985-10-01
I discuss aspects of composite models of quarks and leptons connected with the dynamics of how these fermions acquire mass. Several issues related to the protection mechanisms necessary to keep quarks and leptons light are illustrated by means of concrete examples and a critical overview of suggestions for family replications is given. Some old and new ideas of how one may actually be able to generate small quark and lepton masses are examined, along with some of the difficulties they encounter in practice. (orig.)
A nucleon description based on confinement and a dynamic generation of the quark masses
International Nuclear Information System (INIS)
Caillon, J.C.
2010-01-01
We have considered the nucleon as an MIT bag, but instead of a perturbative vacuum, we use a QCD vacuum modified as compared to the outside space and hence a modified quark-condensate. Quarks acquire their constituent-masses through their interactions with this modified QCD vacuum in a framework of an NJL model. The value of the quark condensate modified in the nucleon is then determined self-consistently by the equilibrium condition for the bag: the outward pressure due to both the motion of three quarks and the modified vacuum in the nucleon must be counterbalanced by the inward pressure of the vacuum outside the bag. We are able to pass continuously from a nucleon description in a pure MIT bag model to a description using constituent quark masses determined in an NJL model.
Gluon mass generation without seagull divergences
International Nuclear Information System (INIS)
Aguilar, Arlene C.; Papavassiliou, Joannis
2010-01-01
Dynamical gluon mass generation has been traditionally plagued with seagull divergences, and all regularization procedures proposed over the years yield finite but scheme-dependent gluon masses. In this work we show how such divergences can be eliminated completely by virtue of a characteristic identity, valid in dimensional regularization. The ability to trigger the aforementioned identity hinges crucially on the particular Ansatz employed for the three-gluon vertex entering into the Schwinger-Dyson equation governing the gluon propagator. The use of the appropriate three-gluon vertex brings about an additional advantage: one obtains two separate (but coupled) integral equations, one for the effective charge and one for the gluon mass. This system of integral equations has a unique solution, which unambiguously determines these two quantities. Most notably, the effective charge freezes in the infrared, and the gluon mass displays power-law running in the ultraviolet, in agreement with earlier considerations.
Dynamic modelling of nuclear steam generators
International Nuclear Information System (INIS)
Kerlin, T.W.; Katz, E.M.; Freels, J.; Thakkar, J.
1980-01-01
Moving boundary, nodal models with dynamic energy balances, dynamic mass balances, quasi-static momentum balances, and an equivalent single channel approach have been developed for steam generators used in nuclear power plants. The model for the U-tube recirculation type steam generator is described and comparisons are made of responses from models of different complexity; non-linear versus linear, high-order versus low order, detailed modeling of the control system versus a simple control assumption. The results of dynamic tests on nuclear power systems show that when this steam generator model is included in a system simulation there is good agreement with actual plant performance. (author)
Dynamics of Variable Mass Systems
Eke, Fidelis O.
1998-01-01
This report presents the results of an investigation of the effects of mass loss on the attitude behavior of spinning bodies in flight. The principal goal is to determine whether there are circumstances under which the motion of variable mass systems can become unstable in the sense that their transverse angular velocities become unbounded. Obviously, results from a study of this kind would find immediate application in the aerospace field. The first part of this study features a complete and mathematically rigorous derivation of a set of equations that govern both the translational and rotational motions of general variable mass systems. The remainder of the study is then devoted to the application of the equations obtained to a systematic investigation of the effect of various mass loss scenarios on the dynamics of increasingly complex models of variable mass systems. It is found that mass loss can have a major impact on the dynamics of mechanical systems, including a possible change in the systems stability picture. Factors such as nozzle geometry, combustion chamber geometry, propellant's initial shape, size and relative mass, and propellant location can all have important influences on the system's dynamic behavior. The relative importance of these parameters on-system motion are quantified in a way that is useful for design purposes.
Dynamical generation of flavour
Indian Academy of Sciences (India)
Introduction of family symmetry and generation of flavour structure by Yukawa couplings arising as vacuum expectation values (VEVs) of 'spurion' fields offers an attractive alternative prospect for understanding flavour structure [1]. Model builders have considered various. Pramana – J. Phys., Vol. 86, No. 2, February 2016.
Generative Models of Conformational Dynamics
Langmead, Christopher James
2014-01-01
Atomistic simulations of the conformational dynamics of proteins can be performed using either Molecular Dynamics or Monte Carlo procedures. The ensembles of three-dimensional structures produced during simulation can be analyzed in a number of ways to elucidate the thermodynamic and kinetic properties of the system. The goal of this chapter is to review both traditional and emerging methods for learning generative models from atomistic simulation data. Here, the term ‘generative’ refers to a...
Quark ACM with topologically generated gluon mass
Choudhury, Ishita Dutta; Lahiri, Amitabha
2016-03-01
We investigate the effect of a small, gauge-invariant mass of the gluon on the anomalous chromomagnetic moment (ACM) of quarks by perturbative calculations at one-loop level. The mass of the gluon is taken to have been generated via a topological mass generation mechanism, in which the gluon acquires a mass through its interaction with an antisymmetric tensor field Bμν. For a small gluon mass ( ACM at momentum transfer q2 = -M Z2. We compare those with the ACM calculated for the gluon mass arising from a Proca mass term. We find that the ACM of up, down, strange and charm quarks vary significantly with the gluon mass, while the ACM of top and bottom quarks show negligible gluon mass dependence. The mechanism of gluon mass generation is most important for the strange quarks ACM, but not so much for the other quarks. We also show the results at q2 = -m t2. We find that the dependence on gluon mass at q2 = -m t2 is much less than at q2 = -M Z2 for all quarks.
Generative Models of Conformational Dynamics
Langmead, Christopher James
2014-01-01
Atomistic simulations of the conformational dynamics of proteins can be performed using either Molecular Dynamics or Monte Carlo procedures. The ensembles of three-dimensional structures produced during simulation can be analyzed in a number of ways to elucidate the thermodynamic and kinetic properties of the system. The goal of this chapter is to review both traditional and emerging methods for learning generative models from atomistic simulation data. Here, the term ‘generative’ refers to a model of the joint probability distribution over the behaviors of the constituent atoms. In the context of molecular modeling, generative models reveal the correlation structure between the atoms, and may be used to predict how the system will respond to structural perturbations. We begin by discussing traditional methods, which produce multivariate Gaussian models. We then discuss GAMELAN (GrAphical Models of Energy LANdscapes), which produces generative models of complex, non-Gaussian conformational dynamics (e.g., allostery, binding, folding, etc) from long timescale simulation data. PMID:24446358
Anisotropic dynamic mass density for fluidsolid composites
Wu, Ying; Mei, Jun; Sheng, Ping
2012-01-01
By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle
Dynamics of radioactive waste generation
International Nuclear Information System (INIS)
Dogaru, Daniela; Virtopeanu, Cornelia; Ivan, Alexandrina
2008-01-01
In Romania there are in operation three facilities licensed for collection, treatment and storage of radioactive waste resulted from industry, research, medicine, and agriculture, named institutional radioactive waste. The repository, which is of near surface type, is designed for disposing institutional radioactive waste. The institutional radioactive wastes generated are allowed to be disposed into repository according to the waste acceptance criteria, defined for the disposal facility. The radioactive wastes which are not allowed for disposal are stored on the site of each facility which is special authorised for this. The paper describes the dynamics of generation of institutional waste in Romania, both for radioactive waste which are allowed to be disposed into repository and for radioactive waste which are not allowed to be disposed of. (authors)
Model for the generation of leptonic mass
International Nuclear Information System (INIS)
Fryberger, D.
1979-01-01
A self-consistent model for the generation of leptonic mass is developed. In this model it is assumed that bare masses are zero, all of the (charged) leptonic masses being generated by the QED self-interaction. A perturbation expansion for the QED self-mass is formulated, and contact is made between this expansion and the work of Landau and his collaborators. In order to achieve a finite result using this expansion, it is assumed that there is a cutoff at the Landau singularity and that the functional form of the (self-mass) integrand is the same beyond that singularity as it is below. Physical interpretations of these assumptions are discussed. Self-consistency equations are obtained which show that the Landau singularity is in the neighborhood of the Planck mass. This result implies that, as originally suggested by Landau, gravitation may play a role in an ultraviolet cutoff for QED. These equations also yield estimates for the (effective) number of additional pointlike particles that electromagnetically couple to the photon. This latter quantity is consistent with present data from e + e - storage rings
Mass-shell properties of the dynamical quark mass
International Nuclear Information System (INIS)
Reinders, L.J.; Stam, K.
1986-07-01
We discuss the running dynamical quark mass in the framework of the operator product expansion. It is shown that for vertical strokep 2 vertical stroke>m 2 the quark-condensate part of the quark self energy has no contributions of order m 2 or higher, and is frozen to its mass-shell value for smaller vertical strokep 2 vertical stroke. (orig.)
Mass generation and the problem of seagull divergences
International Nuclear Information System (INIS)
Figueiredo, C. T.; Aguilar, A. C.
2016-01-01
The gluon mass generation is a purely non-perturbative effect, and the natural framework to study it in the continuum are the Schwinger-Dyson equations (SDEs) of the theory. At the level of the SDEs the generation of such a mass is associated with the existence of infrared finite solutions for the gluon propagator. From the theoretical point of view, the dynamical gluon mass generation has been traditionally plagued with seagull divergences. In this work, we will review how such divergences can be eliminated completely by virtue of a characteristic identity, valid in dimensional regularization. As a pedagogical example, we will first discuss in the context of scalar QED how it is possible to eliminate all seagull divergences, by triggering the aforementioned special identity, which enforces the masslessness of the photon. Then, we will discuss what happens in QCD and present an Ansatz for the three gluon vertex, which completely eliminates all seagull divergences and at same time allows for the possibility of a dynamical gluon mass generation. (paper)
Mass generation in perturbed massless integrable models
International Nuclear Information System (INIS)
Controzzi, D.; Mussardo, G.
2005-01-01
We extend form-factor perturbation theory to non-integrable deformations of massless integrable models, in order to address the problem of mass generation in such systems. With respect to the standard renormalisation group analysis this approach is more suitable for studying the particle content of the perturbed theory. Analogously to the massive case, interesting information can be obtained already at first order, such as the identification of the operators which create a mass gap and those which induce the confinement of the massless particles in the perturbed theory
Automated mass spectrum generation for new physics
Alloul, Adam; De Causmaecker, Karen; Fuks, Benjamin; Rausch de Traubenberg, Michel
2013-01-01
We describe an extension of the FeynRules package dedicated to the automatic generation of the mass spectrum associated with any Lagrangian-based quantum field theory. After introducing a simplified way to implement particle mixings, we present a new class of FeynRules functions allowing both for the analytical computation of all the model mass matrices and for the generation of a C++ package, dubbed ASperGe. This program can then be further employed for a numerical evaluation of the rotation matrices necessary to diagonalize the field basis. We illustrate these features in the context of the Two-Higgs-Doublet Model, the Minimal Left-Right Symmetric Standard Model and the Minimal Supersymmetric Standard Model.
Dynamics of mechanical systems with variable mass
Belyaev, Alexander
2014-01-01
The book presents up-to-date and unifying formulations for treating dynamics of different types of mechanical systems with variable mass. The starting point is overview of the continuum mechanics relations of balance and jump for open systems from which extended Lagrange and Hamiltonian formulations are derived. Corresponding approaches are stated at the level of analytical mechanics with emphasis on systems with a position-dependent mass and at the level of structural mechanics. Special emphasis is laid upon axially moving structures like belts and chains, and on pipes with an axial flow of fluid. Constitutive relations in the dynamics of systems with variable mass are studied with particular reference to modeling of multi-component mixtures. The dynamics of machines with a variable mass are treated in detail and conservation laws and the stability of motion will be analyzed. Novel finite element formulations for open systems in coupled fluid and structural dynamics are presented.
Quantumness-generating capability of quantum dynamics
Li, Nan; Luo, Shunlong; Mao, Yuanyuan
2018-04-01
We study quantumness-generating capability of quantum dynamics, where quantumness refers to the noncommutativity between the initial state and the evolving state. In terms of the commutator of the square roots of the initial state and the evolving state, we define a measure to quantify the quantumness-generating capability of quantum dynamics with respect to initial states. Quantumness-generating capability is absent in classical dynamics and hence is a fundamental characteristic of quantum dynamics. For qubit systems, we present an analytical form for this measure, by virtue of which we analyze several prototypical dynamics such as unitary dynamics, phase damping dynamics, amplitude damping dynamics, and random unitary dynamics (Pauli channels). Necessary and sufficient conditions for the monotonicity of quantumness-generating capability are also identified. Finally, we compare these conditions for the monotonicity of quantumness-generating capability with those for various Markovianities and illustrate that quantumness-generating capability and quantum Markovianity are closely related, although they capture different aspects of quantum dynamics.
The origin of the first and third generation fermion masses in a technicolor scenario
International Nuclear Information System (INIS)
Doff, A.; Natale, A.A.
2004-01-01
We argue that the masses of the first and third fermionic generations, which are respectively of the order of a few MeV up to a hundred GeV, originate from a dynamical symmetry breaking mechanism leading to masses of the order αμ, where α is a small coupling constant, and μ, in the case of the first fermionic generation, is the scale of the dynamical quark mass (∼250 MeV). For the third fermion generation μ is the value of the dynamical techniquark mass (∼250 GeV). We discuss how this possibility can be implemented in a technicolor scenario, and how the mass of the intermediate generation is generated. (orig.)
Truly random dynamics generated by autonomous dynamical systems
González, J. A.; Reyes, L. I.
2001-09-01
We investigate explicit functions that can produce truly random numbers. We use the analytical properties of the explicit functions to show that a certain class of autonomous dynamical systems can generate random dynamics. This dynamics presents fundamental differences with the known chaotic systems. We present real physical systems that can produce this kind of random time-series. Some applications are discussed.
Generator dynamics in aeroelastic analysis and simulations
Energy Technology Data Exchange (ETDEWEB)
Larsen, T.J.; Hansen, M.H.; Iov, F.
2003-05-01
This report contains a description of a dynamic model for a doubly-fed induction generator implemented in the aeroelastic code HAWC. The model has physical input parameters (resistance, reactance etc.) and input variables (stator and rotor voltage and rotor speed). The model can be used to simulate the generator torque as well as the rotor and stator currents, active and reactive power. A perturbation method has been used to reduce the original generator model equations to a set of equations which can be solved with the same time steps as a typical aeroelastic code. The method is used to separate the fast transients of the model from the slow variations and deduce a reduced order expression for the slow part. Dynamic effects of the first order terms in the model as well as the influence on drive train eigenfrequencies and damping has been investigated. Load response during time simulation of wind turbine response have been compared to simulations with a linear static generator model originally implemented i HAWC. A 2 MW turbine has been modelled in the aeroelastic code HAWC. When using the new dynamic generator model there is an interesting coupling between the generator dynamics and a global turbine vibration mode at 4.5 Hz, which only occurs when a dynamic formulation of the generator equations is applied. This frequency can especially be seen in the electrical power of the generator and the rotational speed of the generator, but also as torque variations in the drive train. (au)
Induction generator models in dynamic simulation tools
DEFF Research Database (Denmark)
Knudsen, Hans; Akhmatov, Vladislav
1999-01-01
For AC network with large amount of induction generators (windmills) the paper demonstrates a significant discrepancy in the simulated voltage recovery after fault in weak networks when comparing dynamic and transient stability descriptions and the reasons of discrepancies are explained...
A Dynamical Origin of the Mass Hierarchy among Neutrinos, Charged Leptons, and Quarks
Akama, Keiichi; Katsuura, Kazuo
1998-01-01
We propose a dynamical mass-generation scenario which naturally realizes the mass hierarchy among the neutrinos, charged leptons and quarks, where the mass is dominated by the self-mass induced through the anomalous (i.e. non-minimal) gauge interactions.
Next Generation Suspension Dynamics Algorithms
Energy Technology Data Exchange (ETDEWEB)
Schunk, Peter Randall [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Higdon, Jonathon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chen, Steven [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2014-12-01
This research project has the objective to extend the range of application, improve the efficiency and conduct simulations with the Fast Lubrication Dynamics (FLD) algorithm for concentrated particle suspensions in a Newtonian fluid solvent. The research involves a combination of mathematical development, new computational algorithms, and application to processing flows of relevance in materials processing. The mathematical developments clarify the underlying theory, facilitate verification against classic monographs in the field and provide the framework for a novel parallel implementation optimized for an OpenMP shared memory environment. The project considered application to consolidation flows of major interest in high throughput materials processing and identified hitherto unforeseen challenges in the use of FLD in these applications. Extensions to the algorithm have been developed to improve its accuracy in these applications.
Mass extrapolation of quarks and leptons to higher generations
Energy Technology Data Exchange (ETDEWEB)
Barik, N [Utkal Univ., Bhubaneswar (India). Dept. of Physics
1981-05-01
An empirical mass formula is tested for the basic fermion sequences of charged quarks and leptons. This relation is a generalization of Barut's mass formula for the lepton sequence (e, ..mu.., tau ....). It is found that successful mass extrapolation to the third and possibly to other higher generations (N > 2) can be obtained with the first and second generation masses as inputs, which predicts the top quark mass msub(t) to be around 20 GeV. This also leads to the mass ratios between members of two different sequences (i) and (i') corresponding to the same higher generations (N > 2).
Mass extrapolation of quarks and leptons to higher generations
International Nuclear Information System (INIS)
Barik, N.
1981-01-01
An empirical mass formula is tested for the basic fermion sequences of charged quarks and leptons. This relation is a generalization of Barut's mass formula for the lepton sequence (e, μ, tau ....). It is found that successful mass extrapolation to the third and possibly to other higher generations (N > 2) can be obtained with the first and second generation masses as inputs, which predicts the top quark mass msub(t) to be around 20 GeV. This also leads to the mass ratios between members of two different sequences (i) and (i') corresponding to the same higher generations (N > 2). (author)
Light baryon masses with dynamical twisted mass fermions
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, C. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Baron, R. [CEA-Saclay, IRFU/Service de Physique Nucleaire, Gif-sur-Yvette (France); Blossier, B. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (DE). John von Neumann-Inst. fuer Computing NIC] (and others)
2008-03-15
We present results on the mass of the nucleon and the {delta} using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at {beta}=3.9 and {beta}=4.05 and on a lattice of 2.4 fm at {beta}=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at {beta}=3.9 and {beta}=4.05 we find a nucleon mass of 964{+-}28(stat.){+-}8(syst.) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p{sup 3}) and O(p{sup 4}) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p{sup 3}) we find a{sub {beta}}{sub =3.9}=0.0890{+-}0.0039(stat.){+-}0.0014(syst.) fm, and a{sub {beta}}{sub =4.05}=0.0691{+-}0.0034(stat.){+-}0.0010(syst.) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r0m we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the {delta}-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at {beta}=3.9 and {beta}=4.05 we find for the masses of the {delta}{sup ++,-} and {delta}{sup +,0} 1316{+-}60(stat.) MeV and 1330{+-}74(stat.) MeV respectively. We confirm
Light baryon masses with dynamical twisted mass fermions
International Nuclear Information System (INIS)
Alexandrou, C.; Blossier, B.
2008-03-01
We present results on the mass of the nucleon and the Δ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at β=3.9 and β=4.05 and on a lattice of 2.4 fm at β=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find a nucleon mass of 964±28(stat.)±8(syst.) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p 3 ) and O(p 4 ) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p 3 ) we find a β=3.9 =0.0890±0.0039(stat.)±0.0014(syst.) fm, and a β=4.05 =0.0691±0.0034(stat.)±0.0010(syst.) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r0m we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the Δ-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find for the masses of the Δ ++,- and Δ +,0 1316±60(stat.) MeV and 1330±74(stat.) MeV respectively. We confirm that in the continuum limit they are also degenerate. (orig.)
Light baryon masses with dynamical twisted mass fermions
International Nuclear Information System (INIS)
Alexandrou, C.; Korzec, T.; Koutsou, G.; Baron, R.; Guichon, P.; Blossier, B.; Herdoiza, G.; Jansen, K.; Brinet, M.; Carbonell, J.; Drach, V.; Dimopoulos, P.; Frezzotti, R.; Farchioni, F.; Liu, Z.; Pene, O.; Michael, C.; Shindler, A.; Urbach, C.; Wenger, U.
2008-01-01
We present results on the mass of the nucleon and the Δ using two dynamical degenerate twisted mass quarks and the tree-level Symanzik improved gauge action. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm at three lattice spacings less than 0.1 fm. We check for cutoff effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at β=3.9 and β=4.05 and on a lattice of 2.4 fm at β=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find a nucleon mass of 963±12(stat)±8(syst) MeV where we used the lattice spacings determined from the pion decay constant to convert to physical units. The systematic error due to the chiral extrapolation is estimated by comparing results obtained at O(p 3 ) and O(p 4 ) heavy baryon chiral perturbation theory. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p 3 ) we find a β=3.9 =0.0889±0.0012(stat)±0.0014(syst) fm, and a β=4.05 =0.0691±0.0010(stat)±0.0010(syst) fm, in good agreement with the values determined from the pion decay constant. Using results from our two smaller lattices spacings at constant r 0 m π we estimate the continuum limit and check consistency with results from the coarser lattice. Results at the continuum limit are chirally extrapolated to the physical point. Isospin violating lattice artifacts in the Δ-system are found to be compatible with zero for the values of the lattice spacings used in this work. Performing a combined fit to our lattice data at β=3.9 and β=4.05 we find for the masses of the Δ ++,- and Δ +,0 1315±24(stat) MeV and 1329±30(stat) MeV, respectively. We confirm that in the continuum limit
Testing substellar models with dynamical mass measurements
Directory of Open Access Journals (Sweden)
Liu M.C.
2011-07-01
Full Text Available We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical models. We have identified three specific problems with theory: (1 We find that model color–magnitude diagrams cannot be reliably used to infer masses as they do not accurately reproduce the colors of ultracool dwarfs of known mass. (2 Effective temperatures inferred from evolutionary model radii are typically inconsistent with temperatures derived from fitting atmospheric models to observed spectra by 100–300 K. (3 For the only known pair of field brown dwarfs with a precise mass (3% and age determination (≈25%, the measured luminosities are ~2–3× higher than predicted by model cooling rates (i.e., masses inferred from Lbol and age are 20–30% larger than measured. To make progress in understanding the observed discrepancies, more mass measurements spanning a wide range of luminosity, temperature, and age are needed, along with more accurate age determinations (e.g., via asteroseismology for primary stars with brown dwarf binary companions. Also, resolved optical and infrared spectroscopy are needed to measure lithium depletion and to characterize the atmospheres of binary components in order to better assess model deficiencies.
Mass generation and chiral symmetry breaking by pseudoparticles
International Nuclear Information System (INIS)
Hietarinta, J.; Palmer, W.F.; Pinsky, S.S.
1978-01-01
Massless QCD is studied with regard to mass generation and chiral SU(N/sub f/) symmetry breaking from pseudoparticle effects. While mass is generated when there is only one massless quark, and chiral U(1) is always broken, no rigorous indication of the breaking of chiral SU(N/sub f/) and mass generation is seen when there are more than one massless quarks in the original theory
Mass generation within conformal invariant theories
International Nuclear Information System (INIS)
Flato, M.; Guenin, M.
1981-01-01
The massless Yang-Mills theory is strongly conformally invariant and renormalizable; however, when masses are introduced the theory becomes nonrenormalizable and weakly conformally invariant. Conditions which recover strong conformal invariance are discussed in the letter. (author)
Supersymmetric Extension of Technicolor & Fermion Mass Generation
DEFF Research Database (Denmark)
Antola, Matti; Di Chiara, Stefano; Sannino, Francesco
2012-01-01
We provide a complete extension of Minimal Walking Technicolor able to account for the standard model fermion masses. The model is supersymmetric at energies greater or equal to the technicolor compositeness scale. We integrate out, at the supersymmetry breaking scale, the elementary Higgses. We...... tests and experimental bounds on the mass spectrum. We then turn to the composite Higgs phenomenology at the LHC and show that current data are already constraining the parameter space of the model....
Anisotropic dynamic mass density for fluidsolid composites
Wu, Ying
2012-10-01
By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle-dependent dipole solution, to the leading-order of solid concentration. The angular dependence vanishes for the square lattice, but at high solid concentrations there is a structure-dependent factor that contributes to the leading-order solution. In all cases, Woods formula is found to be accurately valid for the effective bulk modulus, independent of the structures. Numerical evaluations from the solutions are shown to be in excellent agreement with finite-element simulations. © 2012 Elsevier B.V.
Dynamical gluon mass in the instanton vacuum model
Musakhanov, M.; Egamberdiev, O.
2018-04-01
We consider the modifications of gluon properties in the instanton liquid model (ILM) for the QCD vacuum. Rescattering of gluons on instantons generates the dynamical momentum-dependent gluon mass Mg (q). First, we consider the case of a scalar gluon, no zero-mode problem occurs and its dynamical mass Ms (q) can be found. Using the typical phenomenological values of the average instanton size ρ = 1 / 3 fm and average inter-instanton distance R = 1 fm we get Ms (0) = 256 MeV. We then extend this approach to the real vector gluon with zero-modes carefully considered. We obtain the following expression Mg2 (q) = 2 Ms2 (q). This modification of the gluon in the instanton media will shed light on nonperturbative aspect on heavy quarkonium physics.
Gravitational generation of mass in soliton theory
International Nuclear Information System (INIS)
Kozhevnikov, I.R.; Rybakov, Yu.P.
1985-01-01
It is shown that in the framework of a simple scalar field model, that admits soliton solutions, with gravitational field interactions being specially included, one succeeds in ensuring for a scalar field a correct spacial asymptotics that depends on the system mass. Theory, the quantum relation of a corpuscular-wave dualism is fulfilled for soliton solutions in such a model
Generator dynamics in aeroelastic analysis and simulations
DEFF Research Database (Denmark)
Larsen, Torben J.; Hansen, Morten Hartvig; Iov, F.
2003-01-01
This report contains a description of a dynamic model for a doubly-fed induction generator. The model has physical input parameters (voltage, resistance, reactance etc.) and can be used to calculate rotor and stator currents, hence active and reactivepower. A perturbation method has been used...... to reduce the original generator model equations to a set of equations which can be solved with the same time steps as a typical aeroelastic code. The method is used to separate the fast transients of the modelfrom the slow variations and deduce a reduced order expression for the slow part. Dynamic effects...... of the first order terms in the model as well as the influence on drive train eigenfrequencies and damping has been investigated. Load response during timesimulation of wind turbine response have been compared to simulations with a traditional static generator model based entirely on the slip angle. A 2 MW...
Generated dynamics of Markov and quantum processes
Janßen, Martin
2016-01-01
This book presents Markov and quantum processes as two sides of a coin called generated stochastic processes. It deals with quantum processes as reversible stochastic processes generated by one-step unitary operators, while Markov processes are irreversible stochastic processes generated by one-step stochastic operators. The characteristic feature of quantum processes are oscillations, interference, lots of stationary states in bounded systems and possible asymptotic stationary scattering states in open systems, while the characteristic feature of Markov processes are relaxations to a single stationary state. Quantum processes apply to systems where all variables, that control reversibility, are taken as relevant variables, while Markov processes emerge when some of those variables cannot be followed and are thus irrelevant for the dynamic description. Their absence renders the dynamic irreversible. A further aim is to demonstrate that almost any subdiscipline of theoretical physics can conceptually be put in...
Meson-mass generation by instantons, 2
Energy Technology Data Exchange (ETDEWEB)
Saito, T [Kyoto Prefectural Univ. of Medicine (Japan); Shigemoto, K
1979-05-01
In a previous work we discussed how pseudo-scalar mesons and scalar mesons acquire their masses by instantons in the colored gauge field. We considered there the two-flavor model with chiral U(2) x U(2) symmetry. In the present paper the same problem is discussed, including the chiral flavor U(3) x U(3) symmetry. An importance of non-local effects due to instantons is emphasized.
Dynamic models for distributed generation resources
Energy Technology Data Exchange (ETDEWEB)
Morched, A.S. [BPR Energie, Sherbrooke, PQ (Canada)
2010-07-01
Distributed resources can impact the performance of host power systems during both normal and abnormal system conditions. This PowerPoint presentation discussed the use of dynamic models for identifying potential interaction problems between interconnected systems. The models were designed to simulate steady state behaviour as well as transient responses to system disturbances. The distributed generators included directly coupled and electronically coupled generators. The directly coupled generator was driven by wind turbines. Simplified models of grid-side inverters, electronically coupled wind generators and doubly-fed induction generators (DFIGs) were presented. The responses of DFIGs to wind variations were evaluated. Synchronous machine and electronically coupled generator responses were compared. The system model components included load models, generators, protection systems, and system equivalents. Frequency responses to islanding events were reviewed. The study demonstrated that accurate simulations are needed to predict the impact of distributed generation resources on the performance of host systems. Advances in distributed generation technology have outpaced the development of models needed for integration studies. tabs., figs.
Dynamic and control of a once through steam generator
International Nuclear Information System (INIS)
Gomes, Arivaldo Vicente
1979-01-01
This paper presents a non linear distributed parameter model for the dynamics and feedback control of a large countercurrent heat exchanger used as a once through steam generator for a breeder reactor power plant. A convergent, implicit method has been developed to solve simultaneously the equations of conservation of mass, momentum and energy. The model, applicable to heat exchanger systems in general, has been used specifically to study the performance of a once-through steam generator with respect to its load following ability and stability of throttle steam temperature and pressure. (author)
Third generation masses from a two Higgs model fixed point
International Nuclear Information System (INIS)
Froggatt, C.D.; Knowles, I.G.; Moorhouse, R.G.
1990-01-01
The large mass ratio between the top and bottom quarks may be attributed to a hierarchy in the vacuum expectation values of scalar doublets. We consider an effective renormalisation group fixed point determination of the quartic scalar and third generation Yukawa couplings in such a two doublet model. This predicts a mass m t =220 GeV and a mass ratio m b /m τ =2.6. In its simplest form the model also predicts the scalar masses, including a light scalar with a mass of order the b quark mass. Experimental implications are discussed. (orig.)
Sfermion mass degeneracy, superconformal dynamics, and supersymmetric grand unified theories
International Nuclear Information System (INIS)
Kobayashi, Tatsuo; Noguchi, Tatsuya; Nakano, Hiroaki; Terao, Haruhiko
2002-01-01
We discuss issues in a scenario where hierarchical Yukawa couplings are generated through the strong dynamics of superconformal field theories (SCFTs). Independently of the mediation mechanism of supersymmetry breaking, the infrared convergence property of SCFTs can provide an interesting solution to the supersymmetric flavor problem; sfermion masses are suppressed around the decoupling scale of SCFTs and eventually become degenerate to some degree, thanks to family-independent radiative corrections governed by the gaugino masses of the minimal supersymmetric standard model (MSSM). We discuss under what conditions the degeneracy of the sfermion mass can be estimated in a simple manner. We also discuss the constraints from lepton flavor violations. We then explicitly study sfermion mass degeneracy within the framework of grand unified theories coupled to SCFTs. It is found that the degeneracy for right-handed sleptons becomes worse in the conventional SU(5) model than in the MSSM. On the other hand, in the flipped SU(5)xU(1) model, each right-handed lepton is still an SU(5) singlet, whereas the B-ino mass M 1 is determined by two independent gaugino masses of SU(5)xU(1). These two properties enable us to have an improved degeneracy for the right-handed sleptons. We also speculate on how further improvement can be obtained in the SCFT approach
Improving the accuracy of dynamic mass calculation
Directory of Open Access Journals (Sweden)
Oleksandr F. Dashchenko
2015-06-01
Full Text Available With the acceleration of goods transporting, cargo accounting plays an important role in today's global and complex environment. Weight is the most reliable indicator of the materials control. Unlike many other variables that can be measured indirectly, the weight can be measured directly and accurately. Using strain-gauge transducers, weight value can be obtained within a few milliseconds; such values correspond to the momentary load, which acts on the sensor. Determination of the weight of moving transport is only possible by appropriate processing of the sensor signal. The aim of the research is to develop a methodology for weighing freight rolling stock, which increases the accuracy of the measurement of dynamic mass, in particular wagon that moves. Apart from time-series methods, preliminary filtration for improving the accuracy of calculation is used. The results of the simulation are presented.
Baryogenesis, neutrino masses, and dynamical dark energy
International Nuclear Information System (INIS)
Eisele, M.T.
2007-01-01
This thesis considers several models that connect different areas of particle physics and cosmology. Our first discussion in this context concerns a baryogenesis scenario, in which the baryon asymmetry of our universe is created through the dynamics of a dark energy field, thereby illustrating that these two topics might be related. Subsequently, several neutrino mass models are analyzed, which make use of an extra-dimensional setting to overcome certain problems of their fourdimensional counterparts. The central discussion of this thesis concerns a leptogenesis model with many standard model singlets. Amongst other things, we show that the presence of these states can lower the standard bound for the necessary reheating temperature of the universe by at least one and a half orders of magnitude. To further motivate this approach, we also discuss an explicit, extradimensional leptogenesis scenario that naturally yields many of the ingredients required in this context. (orig.)
Baryogenesis, neutrino masses, and dynamical dark energy
Energy Technology Data Exchange (ETDEWEB)
Eisele, M.T.
2007-10-09
This thesis considers several models that connect different areas of particle physics and cosmology. Our first discussion in this context concerns a baryogenesis scenario, in which the baryon asymmetry of our universe is created through the dynamics of a dark energy field, thereby illustrating that these two topics might be related. Subsequently, several neutrino mass models are analyzed, which make use of an extra-dimensional setting to overcome certain problems of their fourdimensional counterparts. The central discussion of this thesis concerns a leptogenesis model with many standard model singlets. Amongst other things, we show that the presence of these states can lower the standard bound for the necessary reheating temperature of the universe by at least one and a half orders of magnitude. To further motivate this approach, we also discuss an explicit, extradimensional leptogenesis scenario that naturally yields many of the ingredients required in this context. (orig.)
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)
Prediction of new Quarks, Generations and Quark Masses
Lach, Thedore
2002-04-01
The Standard model currently suggests no relationship between the quark and lepton masses. The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an up quark mass of 237.31 MeV/c2 and a dn quark mass of 42.392 MeV/c2. These two new quarks help explain the numerical relationship between all the quark and lepton masses in a single function. The mass of each SNU-P (quark or lepton) is just the geometric mean of two related SNU-Ps, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.743828 (predicted), 117.3520, 1778.38, 26950.08 MeV. The resulting slope of these masses when plotted on semi log paper is "e" to 5 significant figures using the currently accepted mass for Tau. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these quarks, and lepton.
Information feedback and mass media effects in cultural dynamics
Gonzalez-Avella, J. C.; Cosenza, M. G.; Klemm, K.; Eguiluz, V. M.; Miguel, M. San
2007-01-01
We study the effects of different forms of information feedback associated with mass media on an agent-agent based model of the dynamics of cultural dissemination. In addition to some processes previously considered, we also examine a model of local mass media influence in cultural dynamics. Two mechanisms of information feedback are investigated: (i) direct mass media influence, where local or global mass media act as an additional element in the network of interactions of each agent, and (i...
Classification of mammographic masses using generalized dynamic fuzzy neural networks
International Nuclear Information System (INIS)
Lim, Wei Keat; Er, Meng Joo
2004-01-01
In this article, computer-aided classification of mammographic masses using generalized dynamic fuzzy neural networks (GDFNN) is presented. The texture parameters, derived from first-order gradient distribution and gray-level co-occurrence matrices, were computed from the regions of interest. A total of 343 images containing 180 benign masses and 163 malignant masses from the Digital Database for Screening Mammography were analyzed. A fast approach of automatically generating fuzzy rules from training samples was implemented to classify tumors. This work is novel in that it alleviates the problem of requiring a designer to examine all the input-output relationships of a training database in order to obtain the most appropriate structure for the classifier in a conventional computer-aided diagnosis. In this approach, not only the connection weights can be adjusted, but also the structure can be self-adaptive during the learning process. By virtue of the automatic generation of the classifier by the GDFNN learning algorithm, the area under the receiver-operating characteristic curve, A z , attains 0.868±0.020, which corresponds to a true-positive fraction of 95.0% at a false positive fraction of 52.8%. The corresponding accuracy is 70.0%, the positive predictive value is 62.0%, and the negative predictive value is 91.4%
Torsion-induced gauge superfield mass generation for gauge-invariant non-linear. sigma. -models
Energy Technology Data Exchange (ETDEWEB)
Helayel-Neto, J.A. (Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro Universidade Catolica de Petropolis, RJ (Brazil)); Mokhtari, S. (International Centre for Theoretical Physics, Trieste (Italy)); Smith, A.W. (Universidade Catolica de Petropolis, RJ (Brazil))
1989-12-21
It is shown that the explicit breaking of (1,0)-supersymmetry by means of a torsion-like term yields dynamical mass generation for the gauge superfields which couple to a (1,0)-supersymmetric non-linear {sigma}-model. (orig.).
Static and dynamic high power, space nuclear electric generating systems
International Nuclear Information System (INIS)
Wetch, J.R.; Begg, L.L.; Koester, J.K.
1985-01-01
Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed. 10 references
Dynamic simulation of steam generator failures
Energy Technology Data Exchange (ETDEWEB)
Meister, G [Institut fuer Nukleare Sicherheitsforschung, Kernforschungsanlage Juelich GmbH, Juelich (Germany)
1988-07-01
A computer program will be described which is capable to simulate severe transients in a gas heated steam generator. Such transients may arise in the safety analysis of accidents resulting from failures in the heat removal system of an HTGR power plant. Important failure modes which have to be considered are ruptures of one or more steam generator tubes leading to water or steam ejection into the primary system or anomalous operating conditions which my cause damage due to excessive thermal stress. Examples are the complete dryout as a consequence of feedwater interrupt in connection with continuing gas heating and the reflooding of the secondary channel with cold feedwater after dryout. The steam generator program which is capable to simulate accidents of this type is written as a module which can be implemented into a program system fur the simulation of the total heat rejection system. It based on an advanced mathematical model for the two phase flow taking deviations from thermal equilibrium into account. Mass, energy and momentum balances for the primary and secondary fluid and the heat diffusion equations for the heat exchanging wall form a system of coupled differential equations which is solved numerically by an algorithm which is stiffly stable and suppresses effectively oscillations of numerical origin. Results of the simulation of transients of the type mentioned above will be presented and discussed. (author)
Dynamic simulation of steam generator failures
International Nuclear Information System (INIS)
Meister, G.
1988-01-01
A computer program will be described which is capable to simulate severe transients in a gas heated steam generator. Such transients may arise in the safety analysis of accidents resulting from failures in the heat removal system of an HTGR power plant. Important failure modes which have to be considered are ruptures of one or more steam generator tubes leading to water or steam ejection into the primary system or anomalous operating conditions which my cause damage due to excessive thermal stress. Examples are the complete dryout as a consequence of feedwater interrupt in connection with continuing gas heating and the reflooding of the secondary channel with cold feedwater after dryout. The steam generator program which is capable to simulate accidents of this type is written as a module which can be implemented into a program system fur the simulation of the total heat rejection system. It based on an advanced mathematical model for the two phase flow taking deviations from thermal equilibrium into account. Mass, energy and momentum balances for the primary and secondary fluid and the heat diffusion equations for the heat exchanging wall form a system of coupled differential equations which is solved numerically by an algorithm which is stiffly stable and suppresses effectively oscillations of numerical origin. Results of the simulation of transients of the type mentioned above will be presented and discussed. (author)
Natural four-generation mass textures in MSSM brane worlds
International Nuclear Information System (INIS)
Lebed, Richard F.; Mayes, Van E.
2011-01-01
A fourth generation of standard model fermions is usually considered unlikely due to constraints from direct searches, electroweak precision measurements, and perturbative unitarity. We show that fermion mass textures consistent with all constraints may be obtained naturally in a model with four generations constructed from intersecting D6-branes on a T 6 /(Z 2 xZ 2 ) orientifold. The Yukawa matrices of the model are rank 2, so that only the third- and fourth-generation fermions obtain masses at the trilinear level. The first two generations obtain masses via higher-order couplings and are therefore naturally lighter. In addition, we find that the third and fourth generations automatically split in mass, but do not mix at leading order. Furthermore, the standard model gauge couplings automatically unify at the string scale, and all the hidden-sector gauge groups become confining in the range 10 13 -10 16 GeV, so that the model becomes effectively a four-generation minimal supersymmetric standard model at low energies.
Next Generation Carbon-Nitrogen Dynamics Model
Xu, C.; Fisher, R. A.; Vrugt, J. A.; Wullschleger, S. D.; McDowell, N. G.
2012-12-01
Nitrogen is a key regulator of vegetation dynamics, soil carbon release, and terrestrial carbon cycles. Thus, to assess energy impacts on the global carbon cycle and future climates, it is critical that we have a mechanism-based and data-calibrated nitrogen model that simulates nitrogen limitation upon both above and belowground carbon dynamics. In this study, we developed a next generation nitrogen-carbon dynamic model within the NCAR Community Earth System Model (CESM). This next generation nitrogen-carbon dynamic model utilized 1) a mechanistic model of nitrogen limitation on photosynthesis with nitrogen trade-offs among light absorption, electron transport, carboxylation, respiration and storage; 2) an optimal leaf nitrogen model that links soil nitrogen availability and leaf nitrogen content; and 3) an ecosystem demography (ED) model that simulates the growth and light competition of tree cohorts and is currently coupled to CLM. Our three test cases with changes in CO2 concentration, growing temperature and radiation demonstrate the model's ability to predict the impact of altered environmental conditions on nitrogen allocations. Currently, we are testing the model against different datasets including soil fertilization and Free Air CO2 enrichment (FACE) experiments across different forest types. We expect that our calibrated model will considerably improve our understanding and predictability of vegetation-climate interactions.itrogen allocation model evaluations. The figure shows the scatter plots of predicted and measured Vc,max and Jmax scaled to 25 oC (i.e.,Vc,max25 and Jmax25) at elevated CO2 (570 ppm, test case one), reduced radiation in canopy (0.1-0.9 of the radiation at the top of canopy, test case two) and reduced growing temperature (15oC, test case three). The model is first calibrated using control data under ambient CO2 (370 ppm), radiation at the top of the canopy (621 μmol photon/m2/s), the normal growing temperature (30oC). The fitted model
Prediction of new Quarks, Generations & low Mass Quarks
Lach, Theodore
2003-04-01
The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an "up" quark of mass 237.31 MeV/c2 and a "dn" quark of mass 42.392 MeV/c2. These two new predicted quarks helped to determine that the masses of the quarks and leptons are all related by a geometric progression relationship. The mass of each quark or lepton is just the "geometric mean" of two related elementary particles, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.74 (predicted), 117.3, 1778.4 (tau), 26950.1 MeV. The geometric ratio of this progression is 15.154 (e to the power e). The mass of the tau in this theory agrees very well with accepted values. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237.31 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these new quarks, and lepton. Ref. Masses of the Sub-Nuclear Particles, nucl-th/ 0008026, @ http://xxx.lanl.gov. Infinite Energy, Vol 5, issue 30.
Discussion on mass concrete construction of wind turbine generator foundation
Shang, Liang; Wu, Chaoxiang; Yin, Xiaoyong
2018-04-01
Wind power is one of the main power sources currently. China has rich wind power resources, wind power plants are developed faster and faster. However, China wind power construction started late, which is lack of relevant experience technology. It is easy to produce quality problems. The key to the construction quality of wind power plant is the construction quality of mass concrete construction. Therefore, construction technology and quality control of wind turbine generator foundation mass concrete are discussed and analyzed in the paper.
Evidence of ghost suppression in gluon mass scale dynamics
Aguilar, A. C.; Binosi, D.; Figueiredo, C. T.; Papavassiliou, J.
2018-03-01
In this work we study the impact that the ghost sector of pure Yang-Mills theories may have on the generation of a dynamical gauge boson mass scale, which hinges on the appearance of massless poles in the fundamental vertices of the theory, and the subsequent realization of the well-known Schwinger mechanism. The process responsible for the formation of such structures is itself dynamical in nature, and is governed by a set of Bethe-Salpeter type of integral equations. While in previous studies the presence of massless poles was assumed to be exclusively associated with the background-gauge three-gluon vertex, in the present analysis we allow them to appear also in the corresponding ghost-gluon vertex. The full analysis of the resulting Bethe-Salpeter system reveals that the contribution of the poles associated with the ghost-gluon vertex are particularly suppressed, their sole discernible effect being a slight modification in the running of the gluon mass scale, for momenta larger than a few GeV. In addition, we examine the behavior of the (background-gauge) ghost-gluon vertex in the limit of vanishing ghost momentum, and derive the corresponding version of Taylor's theorem. These considerations, together with a suitable Ansatz, permit us the full reconstruction of the pole sector of the two vertices involved.
Impact of mass generation for spin-1 mediator simplified models
International Nuclear Information System (INIS)
Bell, Nicole F.; Cai, Yi; Leane, Rebecca K.
2017-01-01
In the simplified dark matter models commonly studied, the mass generation mechanism for the dark fields is not typically specified. We demonstrate that the dark matter interaction types, and hence the annihilation processes relevant for relic density and indirect detection, are strongly dictated by the mass generation mechanism chosen for the dark sector particles, and the requirement of gauge invariance. We focus on the class of models in which fermionic dark matter couples to a spin-1 vector or axial-vector mediator. However, in order to generate dark sector mass terms, it is necessary in most cases to introduce a dark Higgs field and thus a spin-0 scalar mediator will also be present. In the case that all the dark sector fields gain masses via coupling to a single dark sector Higgs field, it is mandatory that the axial-vector coupling of the spin-1 mediator to the dark matter is non-zero; the vector coupling may also be present depending on the charge assignments. For all other mass generation options, only pure vector couplings between the spin-1 mediator and the dark matter are allowed. If these coupling restrictions are not obeyed, unphysical results may be obtained such as a violation of unitarity at high energies. These two-mediator scenarios lead to important phenomenology that does not arise in single mediator models. We survey two-mediator dark matter models which contain both vector and scalar mediators, and explore their relic density and indirect detection phenomenology.
Generating Dynamic Persistence in the Time Domain
Guerrero, A.; Smith, L. A.; Smith, L. A.; Kaplan, D. T.
2001-12-01
Many dynamical systems present long-range correlations. Physically, these systems vary from biological to economical, including geological or urban systems. Important geophysical candidates for this type of behaviour include weather (or climate) and earthquake sequences. Persistence is characterised by slowly decaying correlation function; that, in theory, never dies out. The Persistence exponent reflects the degree of memory in the system and much effort has been expended creating and analysing methods that successfully estimate this parameter and model data that exhibits persistence. The most widely used methods for generating long correlated time series are not dynamical systems in the time domain, but instead are derived from a given spectral density. Little attention has been drawn to modelling persistence in the time domain. The time domain approach has the advantage that an observation at certain time can be calculated using previous observations which is particularly suitable when investigating the predictability of a long memory process. We will describe two of these methods in the time domain. One is a traditional approach using fractional ARIMA (autoregressive and moving average) models; the second uses a novel approach to extending a given series using random Fourier basis functions. The statistical quality of the two methods is compared, and they are contrasted with weather data which shows, reportedly, persistence. The suitability of this approach both for estimating predictability and for making predictions is discussed.
Radiatively generated hierarchy of lepton and quark masses
Energy Technology Data Exchange (ETDEWEB)
Hernández, A.E. Cárcamo; Kovalenko, Sergey; Schmidt, Ivan [Centro Científico Tecnológico de Valparaíso-CCTVal, Universidad Técnica Federico Santa María,Casilla 110-V, Valparaíso (Chile)
2017-02-24
We propose a model for radiatively generating the hierarchy of the Standard Model (SM) fermion masses: tree-level top quark mass; 1-loop bottom, charm, tau and muon masses; 2-loop masses for the light up, down and strange quarks as well as for the electron; and 4-loop masses for the light active neutrinos. Our model is based on a softly-broken S{sub 3}×Z{sub 2} discrete symmetry. Its scalar sector consists only of one SM Higgs doublet and three electrically neutral SM-singlet scalars. We do not need to invoke either electrically charged scalar fields, or an extra SU{sub 2L} scalar doublet, or the spontaneous breaking of the discrete group, which are typical for other radiative models in the literature. The model features a viable scalar dark matter candidate.
Internal Mass Motion for Spacecraft Dynamics and Control
National Research Council Canada - National Science Library
Hall, Christopher D
2008-01-01
We present a detailed description of the application of a noncanonical Hamiltonian formulation to the modeling, analysis, and simulation of the dynamics of gyrostat spacecraft with internal mass motion...
A radiative corrections scheme for generation of the lepton masses
International Nuclear Information System (INIS)
Pisano, F.; Pleitez, V.; Tonasse, M.D.
1994-01-01
We consider in the context of 331 model of the electroweak interactions the generation of the lepton masses by introducing a single neutral right-handed singlet in a radiatively corrections scheme. By adding a lepton-baryon number violating term in the Higgs potential, we show that one can have the right mass spectrum for the leptons without introducing a sextet of Higgs fields which is present in the original model. (author) of Higgs fields which is present in the original model. (author)
Off-diagonal mass generation for Yang-Mills theories in the maximal Abelian gauge
International Nuclear Information System (INIS)
Dudal, D.; Verschelde, H.; Sarandy, M.S.
2007-01-01
We investigate a dynamical mass generation mechanism for the off-diagonal gluons and ghosts in SU(N) Yang-Mills theories, quantized in the maximal Abelian gauge. Such a mass can be seen as evidence for the Abelian dominance in that gauge. It originates from the condensation of a mixed gluon-ghost operator of mass dimension two, which lowers the vacuum energy. We construct an effective potential for this operator by a combined use of the local composite operators technique with algebraic renormalization and we discuss the gauge parameter independence of the results. We also show that it is possible to connect the vacuum energy, due to the mass dimension two condensate discussed here, with the non-trivial vacuum energy originating from the condensate 2 μ >, which has attracted much attention in the Landau gauge. (author)
Dynamic analysis of CHASNUPP steam generator structure during shipping
International Nuclear Information System (INIS)
Han Liangbi; Xu Jinkang; Zhou Meiwu; He Yinbiao
1998-07-01
The dynamic analysis of CHASNUPP steam generator during shipping is described, including the simplified mathematical model, acceleration power spectrum of ocean wave induced random vibration, the dynamic analysis of steam generator structure under random loading, the applied computer code and calculated results
Salivary gland masses. Dynamic MR imaging and pathologic correlation
International Nuclear Information System (INIS)
Park, Jinho; Inoue, Shingo; Ishizuka, Yasuhito; Shindo, Hiroaki; Kawanishi, Masayuki; Kakizaki, Dai; Abe, Kimihiko; Ebihara, Yoshiro
1997-01-01
To evaluate the efficiency of dynamic contrast-enhanced magnetic resonance imaging (MRI) for the diagnosis of salivary gland masses. We retrospectively examined 19 salivary gland masses that were pathologically diagnosed by surgical operation or biopsy. We obtained T1- and T2-weighted images on MRI, performed dynamic studies on each mass and examined the correlation between enhancement patterns and pathological findings. Four enhancement patterns were recognized on contrast-enhanced MRI: type 1 showed marked, homogeneous enhancement; type 2 slights, homogeneous enhancement; type 3 marginal enhancement; and type 4 poor enhancement of the mass. Most pleomorphic adenomas had a type 1 enhancement pattern, but two had a type 2 pattern. Pathologically, each mass enhancement pattern had different tumor cell and matrix components. Warthin's tumor generally showed the type 4 pattern. Primary malignant tumors of the salivary gland all showed the type 3 pattern, and pathological specimens showed many tumor cells along the marginal portion of the tumor. One inflammatory cyst and one Warthin's tumor also showed the type 3 pattern. Except for metastatic renal cell carcinoma, the enhancement patterns of late phase images and dynamic study images were the same. Dynamic MRI added little diagnostic information about salivary gland masses, but the contrast-enhanced MR features correlated well with the pathological findings. (author)
Mass generation and related issues from exotic higher dimensions
Energy Technology Data Exchange (ETDEWEB)
Colatto, Luiz Paulo [Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca (CEFET), Petropolis, RJ (Brazil); Andrade, Marco Antonio de [Universidade do Estado do Rio de Janeiro (UERJ), Resende, RJ (Brazil); Assis, Leonardo Paulo Guimaraes de; Helayel-Neto, Jose Abdalla [Centro Brasileiro de Pesquisas Fisicas(LAFEX/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Experimental de Altas Energias; Matheus-Valle, Jose Luiz [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil); Rojas, Moises [Universidade Federal de Lavras, MG (Brazil)
2011-07-01
Full text: he main purpose of this work is to show that massless Dirac equation formulated for non-interacting Majorana-Weyl spinors in higher dimensions, particularly in D = 1 + 9 and D = 5 + 5, may yield to an interpretation of massive Majorana and Dirac spinors in D = 1 + 3 dimensions. The particular case of a dimensional reduction from D = 4 + 4 to D = 1 + 3 has already been fairly-well discussed in the literature. By adopting suitable representations of the Dirac matrices in higher dimensions, we pursue the investigation of which higher dimensional space-times and which metric signatures concerning massless Dirac equations in highermay induce massive spinors in D = 1+3 dimensions. The mixing of the chiral fermions in higher dimensions may induce a mechanism such that four massive Majorana fermions may show up and, at an appropriate limit an almost zero and a huge mass show up with corresponding left-handed and right-handed eigenstates. This mechanism could reassess a peculiar connection with the See-Saw scheme associated to neutrino with Majorana-type masses. The masses of the particle are fixed by the dimensional reduction scheme, which the decoupled dimensions contribute coordinates and depend on the mass invariants in lower dimensions. This proposal should allow us to understand the generation of hierarchies for the fermionic masses in D = 1 + 3, or in lower dimensions in general, starting from the constraints between the energy and the momentum in (n; n) dimensions. For the initial D = 5 + 5 Majorana-Weyl spinors framework using the Weyl representation to the Dirac matrices we observe an intriguing decomposition of space-time that result in two equivalent D = 1 + 4 massive spinors which mass term, in D = 1 + 3 included, is originated from the remained component and that could induce a Brane-World mechanism. (author)
Infrared divergences, mass shell singularities and gauge dependence of the dynamical fermion mass
International Nuclear Information System (INIS)
Das, Ashok K.; Frenkel, J.; Schubert, C.
2013-01-01
We study the behavior of the dynamical fermion mass when infrared divergences and mass shell singularities are present in a gauge theory. In particular, in the massive Schwinger model in covariant gauges we find that the pole of the fermion propagator is divergent and gauge dependent at one loop, but the leading singularities cancel in the quenched rainbow approximation. On the other hand, in physical gauges, we find that the dynamical fermion mass is finite and gauge independent at least up to one loop
Large mass hierarchies from strongly-coupled dynamics
Energy Technology Data Exchange (ETDEWEB)
Athenodorou, Andreas [Department of Physics, University of Cyprus,B.O. Box 20537, 1678 Nicosia (Cyprus); Bennett, Ed [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea SA2 8PP (United Kingdom); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI),Nagoya University,Furo, Chikusa, Nagoya 464-8602 (Japan); Bergner, Georg [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics,University of Bern,Sidlerstrasse 5, CH-3012 Bern (Switzerland); Elander, Daniel [National Institute for Theoretical Physics, School of Physics andMandelstam Institute for Theoretical Physics, University of the Witwatersrand,1 Jan Smuts Avenue, Johannesburg, Wits 2050 (South Africa); Lin, C.-J. David [Institute of Physics, National Chiao-Tung University,1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan (China); CNRS, Aix Marseille Université, Université de Toulon, Centre de Physique Théorique,UMR 7332, F-13288 Marseille (France); Lucini, Biagio; Piai, Maurizio [Department of Physics, College of Science, Swansea University,Singleton Park, Swansea SA2 8PP (United Kingdom)
2016-06-20
Besides the Higgs particle discovered in 2012, with mass 125 GeV, recent LHC data show tentative signals for new resonances in diboson as well as diphoton searches at high center-of-mass energies (2 TeV and 750 GeV, respectively). If these signals are confirmed (or other new resonances are discovered at the TeV scale), the large hierarchies between masses of new bosons require a dynamical explanation. Motivated by these tentative signals of new physics, we investigate the theoretical possibility that large hierarchies in the masses of glueballs could arise dynamically in new strongly-coupled gauge theories extending the standard model of particle physics. We study lattice data on non-Abelian gauge theories in the (near-)conformal regime as well as a simple toy model in the context of gauge/gravity dualities. We focus our attention on the ratio R between the mass of the lightest spin-2 and spin-0 resonances, that for technical reasons is a particularly convenient and clean observable to study. For models in which (non-perturbative) large anomalous dimensions arise dynamically, we show indications that this mass ratio can be large, with R>5. Moreover, our results suggest that R might be related to universal properties of the IR fixed point. Our findings provide an interesting step towards understanding large mass ratios in the non-perturbative regime of quantum field theories with (near) IR conformal behaviour.
Dynamical limits on dark mass in the outer solar system
International Nuclear Information System (INIS)
Hogg, D.W.; Quinlan, G.D.; Tremaine, S.
1991-01-01
Simplified model solar systems with known observational errors are considered in conducting a dynamical search for dark mass and its minimum detectable amount, and in determining the significance of observed anomalies. The numerical analysis of the dynamical influence of dark mass on the orbits of outer planets and comets is presented in detail. Most conclusions presented are based on observations of the four giant planets where the observational errors in latitude and longitude are independent Gaussian variables with a standard deviation. Neptune's long orbital period cannot be predicted by modern ephemerides, and no evidence of dark mass is found in considering this planet. Studying the improvement in fit when observations are fitted to models that consider dark mass is found to be an efficient way to detect dark mass. Planet X must have a mass of more than about 10 times the minimum detectable mass to locate the hypothetical planet. It is suggested that the IRAS survey would have already located the Planet X if it is so massive and close that it dynamically influences the outer planets. Orbital residuals from comets are found to be more effective than those from planets in detecting the Kuiper belt. 35 refs
Dynamics of Current, Charge and Mass
Directory of Open Access Journals (Sweden)
Eisenberg Bob
2017-10-01
Full Text Available Electricity plays a special role in our lives and life. The dynamics of electrons allow light to flow through a vacuum. The equations of electron dynamics are nearly exact and apply from nuclear particles to stars. These Maxwell equations include a special term, the displacement current (of a vacuum. The displacement current allows electrical signals to propagate through space. Displacement current guarantees that current is exactly conserved from inside atoms to between stars, as long as current is defined as the entire source of the curl of the magnetic field, as Maxwell did.We show that the Bohm formulation of quantum mechanics allows the easy definition of the total current, and its conservation, without the dificulties implicit in the orthodox quantum theory. The orthodox theory neglects the reality of magnitudes, like the currents, during times that they are not being explicitly measured.We show how conservation of current can be derived without mention of the polarization or dielectric properties of matter. We point out that displacement current is handled correctly in electrical engineering by ‘stray capacitances’, although it is rarely discussed explicitly. Matter does not behave as physicists of the 1800’s thought it did. They could only measure on a time scale of seconds and tried to explain dielectric properties and polarization with a single dielectric constant, a real positive number independent of everything. Matter and thus charge moves in enormously complicated ways that cannot be described by a single dielectric constant,when studied on time scales important today for electronic technology and molecular biology. When classical theories could not explain complex charge movements, constants in equations were allowed to vary in solutions of those equations, in a way not justified by mathematics, with predictable consequences. Life occurs in ionic solutions where charge is moved by forces not mentioned or described in the
Mass transfer dynamics in double degenerate binary systems
International Nuclear Information System (INIS)
Dan, M; Rosswog, S; Brueggen, M
2009-01-01
We present a numerical study of the mass transfer dynamics prior to the gravitational wave-driven merger of a double white dwarf system. Recently, there has been some discussion about the dynamics of these last stages, different methods seemed to provide qualitatively different results. While earlier SPH simulations indicated a very quick disruption of the binary on roughly the orbital time scale, more recent grid-based calculations find long-lived mass transfer for many orbital periods. Here we demonstrate how sensitive the dynamics of this last stage is to the exact initial conditions. We show that, after a careful preparation of the initial conditions, the reportedly short-lived systems undergo mass transfer for many dozens of orbits. The reported numbers of orbits are resolution-biased and therefore represent only lower limits to what is realized in nature. Nevertheless, the study shows convincingly the convergence of different methods to very similar results.
Dynamic Models of Instruments Using Rotating Unbalanced Masses
Hung, John Y.; Gallaspy, Jason M.; Bishop, Carlee A.
1998-01-01
The motion of telescopes, satellites, and other flight bodies have been controlled by various means in the past. For example, gimbal mounted devices can use electric motors to produce pointing and scanning motions. Reaction wheels, control moment gyros, and propellant-charged reaction jets are other technologies that have also been used. Each of these methods has its advantages, but all actuator systems used in a flight environment face the challenges of minimizing weight, reducing energy consumption, and maximizing reliability. Recently, Polites invented and patented the Rotating Unbalanced Mass (RUM) device as a means for generation scanning motion on flight experiments. RUM devices together with traditional servomechanisms have been successfully used to generate various scanning motions: linear, raster, and circular. The basic principle can be described: A RUM rotating at constant angular velocity exerts a cyclic centrifugal force on the instrument or main body, thus producing a periodic scanning motion. A system of RUM devices exerts no reaction forces on the main body, requires very little energy to rotate the RUMS, and is simple to construct. These are significant advantages over electric motors, reaction wheels, and control moment gyroscopes. Although the RUM device very easily produces scanning motion, an auxiliary control system has been required to maintain the proper orientation, or pointing of the main body. It has been suggested that RUM devices can be used to control pointing dynamics, as well as generate the desired periodic scanning motion. The idea is that the RUM velocity will not be kept constant, but will vary over the period of one RUM rotation. The thought is that the changing angular velocity produces a centrifugal force having time-varying magnitude and direction. The scope of this ongoing research project is to study the pointing control concept, and recommend a direction of study for advanced pointing control using only RUM devices. This
Dirac Mass Dynamics in Multidimensional Nonlocal Parabolic Equations
Lorz, Alexander
2011-01-17
Nonlocal Lotka-Volterra models have the property that solutions concentrate as Dirac masses in the limit of small diffusion. Is it possible to describe the dynamics of the limiting concentration points and of the weights of the Dirac masses? What is the long time asymptotics of these Dirac masses? Can several Dirac masses coexist? We will explain how these questions relate to the so-called "constrained Hamilton-Jacobi equation" and how a form of canonical equation can be established. This equation has been established assuming smoothness. Here we build a framework where smooth solutions exist and thus the full theory can be developed rigorously. We also show that our form of canonical equation comes with a kind of Lyapunov functional. Numerical simulations show that the trajectories can exhibit unexpected dynamics well explained by this equation. Our motivation comes from population adaptive evolution a branch of mathematical ecology which models Darwinian evolution. © Taylor & Francis Group, LLC.
Individual heterogeneity generating explosive system network dynamics.
Manrique, Pedro D; Johnson, Neil F
2018-03-01
Individual heterogeneity is a key characteristic of many real-world systems, from organisms to humans. However, its role in determining the system's collective dynamics is not well understood. Here we study how individual heterogeneity impacts the system network dynamics by comparing linking mechanisms that favor similar or dissimilar individuals. We find that this heterogeneity-based evolution drives an unconventional form of explosive network behavior, and it dictates how a polarized population moves toward consensus. Our model shows good agreement with data from both biological and social science domains. We conclude that individual heterogeneity likely plays a key role in the collective development of real-world networks and communities, and it cannot be ignored.
Individual heterogeneity generating explosive system network dynamics
Manrique, Pedro D.; Johnson, Neil F.
2018-03-01
Individual heterogeneity is a key characteristic of many real-world systems, from organisms to humans. However, its role in determining the system's collective dynamics is not well understood. Here we study how individual heterogeneity impacts the system network dynamics by comparing linking mechanisms that favor similar or dissimilar individuals. We find that this heterogeneity-based evolution drives an unconventional form of explosive network behavior, and it dictates how a polarized population moves toward consensus. Our model shows good agreement with data from both biological and social science domains. We conclude that individual heterogeneity likely plays a key role in the collective development of real-world networks and communities, and it cannot be ignored.
Extraction of left ventricular myocardial mass from dynamic 11C-acetate PET
DEFF Research Database (Denmark)
Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik
Background: Dynamic 11C-acetate PET is used to quantify oxygen metabolism, which is used to calculate left ventricular (LV) myocardial efficiency, an early marker of heart failure. This requires estimation of LV myocardial mass and is typically derived from a separate cardiovascular magnetic...... resonance (CMR) scan. The aim of this study was to explore the feasibility of estimating myocardial mass directly from a dynamic 11C-acetate PET scan. Methods: 21 subjects underwent a 27-min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner. In addition, 10 subjects underwent a dynamic...... 11C-acetate 27-min PET scan on a GE Discovery ST PET/CT scanner. Parametric images of uptake rate K1 and both arterial (VA) and venous (VV) spillover fractions were generated using a basis function implementation of the standard single tissue compartment model using non-gated dynamic data. The LV...
Sea quark contribution to the dynamical mass and light quark content of a nucleon
International Nuclear Information System (INIS)
Singh, J.P.
1995-01-01
We calculate the flavor mixing in the wave function of a light valence quark. For this, we use the idea of dynamical symmetry breaking. A sea quark of a different flavor may appear through the vacuum polarization of a gluon propagator which appears in the gap equation for the dynamical mass. We have also used the fact that any one of these quark lines may undergo condensation. The dependence of the dynamical mass, generated in this way, on the sea quark mass up to quadratic terms has been retained. The momentum dependence is like 1/p 4 , in contrast with the 1/p 2 kind of dependence which occurs for the leading term of the dynamical mass in the subasymptotic region. The extension of the result to the ''mass shell'' yields σ πN =53--54 MeV for the pion-nucleon σ term and m s left-angle p|bar ss|p right-angle=122--264 meV for the strange quark contribution to the proton mass, for different values of parameters. These are in reasonable agreement with current phenomenological estimates of these quantities
Towards dynamic reference information models: Readiness for ICT mass customisation
Verdouw, C.N.; Beulens, A.J.M.; Trienekens, J.H.; Verwaart, D.
2010-01-01
Current dynamic demand-driven networks make great demands on, in particular, the interoperability and agility of information systems. This paper investigates how reference information models can be used to meet these demands by enhancing ICT mass customisation. It was found that reference models for
Automation Framework for Flight Dynamics Products Generation
Wiegand, Robert E.; Esposito, Timothy C.; Watson, John S.; Jun, Linda; Shoan, Wendy; Matusow, Carla
2010-01-01
XFDS provides an easily adaptable automation platform. To date it has been used to support flight dynamics operations. It coordinates the execution of other applications such as Satellite TookKit, FreeFlyer, MATLAB, and Perl code. It provides a mechanism for passing messages among a collection of XFDS processes, and allows sending and receiving of GMSEC messages. A unified and consistent graphical user interface (GUI) is used for the various tools. Its automation configuration is stored in text files, and can be edited either directly or using the GUI.
Dynamic instability forecasting for through-out sodium steam generators
International Nuclear Information System (INIS)
Aleksandrov, V.V.; Rassokhin, N.G.
1985-01-01
Simplified technique for determining boundaries of dynamic instability of through-out sodium steam generators is presented. The technique is based on the application of autoresonance concept to autooscillating model of dynamic instability of a steam-generating channel. Estimated model parameters and basic investigational results for different conditions are given. Assessment is performed according to the instability degree. Use of the technique is effective for multiversion studying of SG design at early designing stages
Language-Based Caching of Dynamically Generated HTML
DEFF Research Database (Denmark)
Brabrand, Claus; Møller, Anders; Olesen, Steffan
2002-01-01
Increasingly, HTML documents are dynamically generated by interactive Web services. To ensure that the client is presented with the newest versions of such documents it is customary to disable client caching causing a seemingly inevitable performance penalty. In the system, dynamic HTML documents...
From bosonic topological transition to symmetric fermion mass generation
You, Yi-Zhuang; He, Yin-Chen; Vishwanath, Ashvin; Xu, Cenke
2018-03-01
A bosonic topological transition (BTT) is a quantum critical point between the bosonic symmetry-protected topological phase and the trivial phase. In this work, we investigate such a transition in a (2+1)-dimensional lattice model with the maximal microscopic symmetry: an internal SO (4 ) symmetry. We derive a description for this transition in terms of compact quantum electrodynamics (QED) with four fermion flavors (Nf=4 ). Within a systematic renormalization group analysis, we identify the critical point with the desired O (4 ) emergent symmetry and all expected deformations. By lowering the microscopic symmetry, we recover the previous Nf=2 noncompact QED description of the BTT. Finally, by merging two BTTs we recover a previously discussed theory of symmetric mass generation, as an SU (2 ) quantum chromodynamics-Higgs theory with Nf=4 flavors of SU (2 ) fundamental fermions and one SU (2 ) fundamental Higgs boson. This provides a consistency check on both theories.
Benchmarking of electrolyte mass transport in next generation lithium batteries
Directory of Open Access Journals (Sweden)
Jonas Lindberg
2017-12-01
Full Text Available Beyond conductivity and viscosity, little is often known about the mass transport properties of next generation lithium battery electrolytes, thus, making performance estimation uncertain when concentration gradients are present, as conductivity only describes performance in the absence of these gradients. This study experimentally measured the diffusion resistivity, originating from voltage loss due to a concentration gradient, together with the ohmic resistivity, obtained from ionic conductivity measurements, hence, evaluating electrolytes both with and without the presence of concentration gradients. Under galvanostatic conditions, the concentration gradients, of all electrolytes examined, developed quickly and the diffusion resistivity rapidly dominated the ohmic resistivity. The electrolytes investigated consisted of lithium salt in: room temperature ionic liquids (RTIL, RTIL mixed organic carbonates, dimethyl sulfoxide (DMSO, and a conventional Li-ion battery electrolyte. At steady state the RTIL electrolytes displayed a diffusion resistivity ~ 20 times greater than the ohmic resistivity. The DMSO-based electrolyte showed mass transport properties similar to the conventional Li-ion battery electrolyte. In conclusion, the results presented in this study show that the diffusion polarization must be considered in applications where high energy and power density are desired.
Higgs bosons and other mechanisms of mass generation
International Nuclear Information System (INIS)
Konopleva, N. P.
1997-01-01
There are two problems under discuss here: 1) are Higgs bosons really necessary for the gauge field mass generation or not, and 2) why are Higgs bosons invisible in the elementary particles experiments? It is shown that in the frame of the classical Lagrangian gauge fields theory the transition from the usual variational problem to isoperimetric one permits us to conserve the local gauge invariance on the solutions of the massive gauge field theory equations. Hence in the massive gauge field theory we can have on the field equation solutions not only the conservation laws corresponding with the first Noether's theorem but Noether's identities corresponding with the second Noether's theorem also. Therefore the alternative renormalization procedure can exist which does not demand of Higgs bosons appearance in the massive gauge field theory for its renormalizability. The interpretation of Higgs mechanism as the phase transition mechanism is discussed. From this point of view the inexplicable absence of the individual Higgs bosons could be the result of the fact that the massive gauge field is the complex system of the massless gauge fields interacting with the condensate of Higgs bosons and quantum vortices in it. In this case the gauge field obtains the mass when the phase transition happens and after that the individual Higgs bosons can not be eliminated from the complex system
Study of mass consciousnessand its dynamics in sociologic research
Directory of Open Access Journals (Sweden)
S. V. Khobta
2017-01-01
Full Text Available The article is dedicated to analysis of the approaches used to study mass consciousness and the methods of their dynamics research. The two following approaches are reviewed: aggregative and group. The author shows that the study of the dynamics of mass consciousness in the modern day science is performed via computer modeling applying agent-oriented models and mass surveys of public opinion. Special attention is given to the concept of mass consciousness according to B. Grushin, where the mass consciousness is analyzed as a complex phenomenon according to its structure and the formation process. It is further analyzed what this particular concept is able to provide for the mass consciousness studies in the times of crises, similar to the situation of the military conflict at the East. It is then proven that the dialectic approach should be used as the basis for the mass consciousness studies adjusted for the interaction dynamics between the individual and collective, spontaneous and the institutionalized inside the collective consciousness. The mass consciousness is a complex structural formation, both heterogeneous and syncretical. Inside this structure one must distinguish between the layers that differ in depth and mobility and pay attention to its various conditions. The layers represent different worldviews, where, depending on the situation, scientific, religious or mystical images of the world can be actualized along with their ideological, moral and aesthetic precepts. These can cross, merge or coexist without contradicting each other and get actualized to a different extent. Besides the aforementioned the mass consciousness serves as a carrier of different kinds of deep, hard to change formations, such as «historical/collective memory», memlexes as well as superficial, most actualized forms, such as mems. It has «public/formal», socially accepted, and «private/real» levels that manifest themselves, in particular, in the forms of
Dynamic Responses of Flexible Cylinders with Low Mass Ratio
Olaoye, Abiodun; Wang, Zhicheng; Triantafyllou, Michael
2017-11-01
Flexible cylinders with low mass ratios such as composite risers are attractive in the offshore industry because they require lower top tension and are less likely to buckle under self-weight compared to steel risers. However, their relatively low stiffness characteristics make them more vulnerable to vortex induced vibrations. Additionally, numerical investigation of the dynamic responses of such structures based on realistic conditions is limited by high Reynolds number, complex sheared flow profile, large aspect ratio and low mass ratio challenges. In the framework of Fourier spectral/hp element method, the current technique employs entropy-viscosity method (EVM) based large-eddy simulation approach for flow solver and fictitious added mass method for structure solver. The combination of both methods can handle fluid-structure interaction problems at high Reynolds number with low mass ratio. A validation of the numerical approach is provided by comparison with experiments.
Emergent Newtonian dynamics and the geometric origin of mass
International Nuclear Information System (INIS)
D’Alessio, Luca; Polkovnikov, Anatoli
2014-01-01
We consider a set of macroscopic (classical) degrees of freedom coupled to an arbitrary many-particle Hamiltonian system, quantum or classical. These degrees of freedom can represent positions of objects in space, their angles, shape distortions, magnetization, currents and so on. Expanding their dynamics near the adiabatic limit we find the emergent Newton’s second law (force is equal to the mass times acceleration) with an extra dissipative term. In systems with broken time reversal symmetry there is an additional Coriolis type force proportional to the Berry curvature. We give the microscopic definition of the mass tensor. The mass tensor is related to the non-equal time correlation functions in equilibrium and describes the dressing of the slow degree of freedom by virtual excitations in the system. In the classical (high-temperature) limit the mass tensor is given by the product of the inverse temperature and the Fubini–Study metric tensor determining the natural distance between the eigenstates of the Hamiltonian. For free particles this result reduces to the conventional definition of mass. This finding shows that any mass, at least in the classical limit, emerges from the distortions of the Hilbert space highlighting deep connections between any motion (not necessarily in space) and geometry. We illustrate our findings with four simple examples. -- Highlights: •Derive the macroscopic Newton’s equation from the microscopic many-particle Schrödinger’s equation. •Deep connection between geometry and dynamics. •Geometrical interpretation of the mass of macroscopic object as deformation of Hilbert space. •Microscopic expression for mass and friction tensors
Dynamics of 'abc' and 'qd' constant parameters induction generator model
DEFF Research Database (Denmark)
Fajardo-R, L.A.; Medina, A.; Iov, F.
2009-01-01
In this paper, parametric sensibility effects on dynamics of the induction generator in the presence of local perturbations are investigated. The study is conducted in a 3x2 MW wind park dealing with abc, qd0 and qd reduced order, induction generator model respectively, and with fluxes as state...
Torsion-induced gauge superfield mass generation for gauge-invariant non-linear σ-models
International Nuclear Information System (INIS)
Helayel-Neto, J.A.; Mokhtari, S.; Smith, A.W.
1989-01-01
It is shown that the explicit breaking of (1,0)-supersymmetry by means of a torsion-like term yields dynamical mass generation for the gauge superfields which couple to a (1,0)-supersymmetric non-linear σ-model. (orig.)
Optimal dynamic economic dispatch of generation: A review
International Nuclear Information System (INIS)
Xia, X.; Elaiw, A.M.
2010-01-01
This paper presents a review of the research of the optimal power dynamic dispatch problem. The dynamic dispatch problem differs from the static economic dispatch problem by incorporating generator ramp rate constraints. There are two different formulations of this problem in the literature. The first formulation is the optimal control dynamic dispatch (OCDD) where the power system generation has been modeled as a control system and optimization is done in the optimal control setting with respect to the ramp rates as input variables. The second one is a later formulation known as the dynamic economic dispatch (DED) where optimization is done with respect to the dispatchable powers of the committed generation units. In this paper we first outline the two formulations, then present an overview on the mathematical optimization methods, Artificial Intelligence (AI) techniques and hybrid methods used to solve the problem incorporating extended and complex objective functions or constraints. The DED problem in deregulated electricity markets is also reported. (author)
Mass generation, the cosmological constant problem, conformal symmetry, and the Higgs boson
Mannheim, Philip D.
2017-05-01
In 2013 the Nobel Prize in Physics was awarded to Francois Englert and Peter Higgs for their work in 1964 along with the late Robert Brout on the mass generation mechanism (the Higgs mechanism) in local gauge theories. This mechanism requires the existence of a massive scalar particle, the Higgs boson, and in 2012 the Higgs boson was finally discovered at the Large Hadron Collider after being sought for almost half a century. In this article we review the work that led to the discovery of the Higgs boson and discuss its implications. We approach the topic from the perspective of a dynamically generated Higgs boson that is a fermion-antifermion bound state rather than an elementary field that appears in an input Lagrangian. In particular, we emphasize the connection with the Bardeen-Cooper-Schrieffer theory of superconductivity. We identify the double-well Higgs potential not as a fundamental potential but as a mean-field effective Lagrangian with a dynamical Higgs boson being generated through a residual interaction that accompanies the mean-field Lagrangian. We discuss what we believe to be the key challenge raised by the discovery of the Higgs boson, namely determining whether it is elementary or composite, and through study of a conformal invariant field theory model as realized with critical scaling and anomalous dimensions, suggest that the width of the Higgs boson might serve as a suitable diagnostic for discriminating between an elementary Higgs boson and a composite one. We discuss the implications of Higgs boson mass generation for the cosmological constant problem, as the cosmological constant receives contributions from the very mechanism that generates the Higgs boson mass in the first place. We show that the contribution to the cosmological constant due to a composite Higgs boson is more tractable and under control than the contribution due to an elementary Higgs boson, and is potentially completely under control if there is an underlying conformal
Evidence for dynamic SU(5) symmetry breaking in meson mass multiplets
International Nuclear Information System (INIS)
Frikkee, E.
1994-07-01
It is shown that the mass differences and multiplet pattern for pseudoscalar and vector mesons correspond to a chain of dynamic symmetry reductions SU(n) contains SU(n-1)xU(1). In this symmetry-reduction model, the differences between the masses of the quark flavours are the result of intra-hadronic interactions. Quark confinement is explained as a consequence of the fact that this symmetry breaking chain only occurs in hadrons. The results of a quantitative analysis of mass splittings in meson multiplets indicate that SU(5) is probably the highest symmetry for hadron states. In the proposed dynamic symmetry breaking scheme with five quark flavours there is no one-to-one correspondence between lepton and quark generations. (orig.)
DEFF Research Database (Denmark)
Harms, Hendrik Johannes; Hansson, Nils Henrik Stubkjær; Tolbod, Lars Poulsen
2016-01-01
Dynamic cardiac positron emission tomography (PET) is used to quantify molecular processes in vivo. However, measurements of left-ventricular (LV) mass and volumes require electrocardiogram (ECG)-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using non......-gated dynamic cardiac PET. METHODS: Thirty-five patients with aortic-valve stenosis and 10 healthy controls (HC) underwent a 27-min 11C-acetate PET/CT scan and cardiac magnetic resonance imaging (CMR). HC were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were......LV and WT only and an overestimation for LVEF at lower values. Intra- and inter-observer correlations were >0.95 for all PET measurements. PET repeatability accuracy in HC was comparable to CMR. CONCLUSION: LV mass and volumes are accurately and automatically generated from dynamic 11C-acetate PET without...
A Generative Computer Model for Preliminary Design of Mass Housing
Directory of Open Access Journals (Sweden)
Ahmet Emre DİNÇER
2014-05-01
Full Text Available Today, we live in what we call the “Information Age”, an age in which information technologies are constantly being renewed and developed. Out of this has emerged a new approach called “Computational Design” or “Digital Design”. In addition to significantly influencing all fields of engineering, this approach has come to play a similar role in all stages of the design process in the architectural field. In providing solutions for analytical problems in design such as cost estimate, circulation systems evaluation and environmental effects, which are similar to engineering problems, this approach is being used in the evaluation, representation and presentation of traditionally designed buildings. With developments in software and hardware technology, it has evolved as the studies based on design of architectural products and production implementations with digital tools used for preliminary design stages. This paper presents a digital model which may be used in the preliminary stage of mass housing design with Cellular Automata, one of generative design systems based on computational design approaches. This computational model, developed by scripts of 3Ds Max software, has been implemented on a site plan design of mass housing, floor plan organizations made by user preferences and facade designs. By using the developed computer model, many alternative housing types could be rapidly produced. The interactive design tool of this computational model allows the user to transfer dimensional and functional housing preferences by means of the interface prepared for model. The results of the study are discussed in the light of innovative architectural approaches.
Vertical hydraulic generators experience with dynamic air gap monitoring
International Nuclear Information System (INIS)
Pollock, G.B.; Lyles, J.F.
1992-01-01
Until recently, dynamic monitoring of the rotor to stator air gap of hydraulic generators was not practical. Cost effective and reliable dyamic air gap monitoring equipment has been developed in recent years. Dynamic air gap monitoring was originally justified because of the desire of the owner to minimize the effects of catastrophic air gap failure. However, monitoring air gaps on a time basis has been shown to be beneficial by assisting in the assessment of hydraulic generator condition. The air gap monitor provides useful information on rotor and stator condition and generator vibration. The data generated by air gap monitors will assist managers in the decision process with respect to the timing and extent of required maintenance for a particular generating unit
Osmosis-Based Pressure Generation: Dynamics and Application
Li, Suyi; Billeh, Yazan N.; Wang, K. W.; Mayer, Michael
2014-01-01
This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators. PMID:24614529
Osmosis-based pressure generation: dynamics and application.
Bruhn, Brandon R; Schroeder, Thomas B H; Li, Suyi; Billeh, Yazan N; Wang, K W; Mayer, Michael
2014-01-01
This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators.
Osmosis-based pressure generation: dynamics and application.
Directory of Open Access Journals (Sweden)
Brandon R Bruhn
Full Text Available This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators.
International Nuclear Information System (INIS)
Yoon, Han Ik; Son, In Soo
2005-01-01
In this paper, we studied about the effect of the open crack and a tip mass on the dynamic behavior of a cantilever pipe conveying fluid with a moving mass. The equation of motion is derived by using Lagrange's equation and analyzed by numerical method. The cantilever pipe is modelled by the Euler-Bernoulli beam theory. The crack section is represented by a local flexibility matrix connecting two undamaged pipe segments. The influences of the crack, the moving mass, the tip mass and its moment of inertia, the velocity of fluid, and the coupling of these factors on the vibration mode, the frequency, and the tip-displacement of the cantilever pipe are analytically clarified
Modelling of windmill induction generators in dynamic simulation programs
DEFF Research Database (Denmark)
Akhmatov, Vladislav; Knudsen, Hans
1999-01-01
with and without a model of the mechanical shaft. The reason for the discrepancies are explained, and it is shown that the phenomenon is due partly to the presence of DC offset currents in the induction machine stator, and partly to the mechanical shaft system of the wind turbine and the generator rotor......For AC networks with large amounts of induction generators-in case of e.g. windmills-the paper demonstrates a significant discrepancy in the simulated voltage recovery after faults in weak networks, when comparing result obtained with dynamic stability programs and transient programs, respectively....... It is shown that it is possible to include a transient model in dynamic stability programs and thus obtain correct results also in dynamic stability programs. A mechanical model of the shaft system has also been included in the generator model...
Directory of Open Access Journals (Sweden)
NianSong Zhang
2015-01-01
Full Text Available A study on the dynamic response of a projectile penetrating concrete is conducted. The evolutional process of projectile mass loss and the effect of mass loss on penetration resistance are investigated using theoretical methods. A projectile penetration model considering projectile mass loss is established in three stages, namely, cratering phase, mass loss penetration phase, and remainder rigid projectile penetration phase.
Galaxy dynamics and the mass density of the universe.
Rubin, V C
1993-06-01
Dynamical evidence accumulated over the past 20 years has convinced astronomers that luminous matter in a spiral galaxy constitutes no more than 10% of the mass of a galaxy. An additional 90% is inferred by its gravitational effect on luminous material. Here I review recent observations concerning the distribution of luminous and nonluminous matter in the Milky Way, in galaxies, and in galaxy clusters. Observations of neutral hydrogen disks, some extending in radius several times the optical disk, confirm that a massive dark halo is a major component of virtually every spiral. A recent surprise has been the discovery that stellar and gas motions in ellipticals are enormously complex. To date, only for a few spheroidal galaxies do the velocities extend far enough to probe the outer mass distribution. But the diverse kinematics of inner cores, peripheral to deducing the overall mass distribution, offer additional evidence that ellipticals have acquired gas-rich systems after initial formation. Dynamical results are consistent with a low-density universe, in which the required dark matter could be baryonic. On smallest scales of galaxies [10 kiloparsec (kpc); Ho = 50 km.sec-1.megaparsec-1] the luminous matter constitutes only 1% of the closure density. On scales greater than binary galaxies (i.e., >/=100 kpc) all systems indicate a density approximately 10% of the closure density, a density consistent with the low baryon density in the universe. If large-scale motions in the universe require a higher mass density, these motions would constitute the first dynamical evidence for nonbaryonic matter in a universe of higher density.
Recoil generated radiotracers in studies of molecular dynamics
International Nuclear Information System (INIS)
Spicer, L.D.
1981-01-01
This chapter summarizes many of the contributions that the recoil technique of generating excited radiotracer atoms in the presence of a thermal environment is making to the field of chemical dynamics. Specific topics discussed critically include characterization of the generation and behavior of excited molecules including fragmentation kinetics and energy transfer, measurement of thermal and hot kinetic parameters, and studies of reaction mechanisms and stereochemistry as a function of reaction energy. Distinctive features that provide unique approaches to dynamical problems are evaluated in detail and the complementarity with more conventional techniques is addressed. Prospects for future applications are also presented
Dynamic modeling, simulation and control of energy generation
Vepa, Ranjan
2013-01-01
This book addresses the core issues involved in the dynamic modeling, simulation and control of a selection of energy systems such as gas turbines, wind turbines, fuel cells and batteries. The principles of modeling and control could be applied to other non-convention methods of energy generation such as solar energy and wave energy.A central feature of Dynamic Modeling, Simulation and Control of Energy Generation is that it brings together diverse topics in thermodynamics, fluid mechanics, heat transfer, electro-chemistry, electrical networks and electrical machines and focuses on their appli
Top and Higgs masses from dynamical electroweak symmetry breaking
International Nuclear Information System (INIS)
Kahana, D.E.
1993-01-01
The standard model of electroweak interactions, with the gauge and Higgs bosons appearing as composites, is derived from a Nambu-Jona-Lasinio-type four-fermion interaction, assumed to be valid above a high scale μ. Simple relationships are found for the composite boson top quark mass ratios and for the weak angle. Assuming three generations and a 'desert' hypothesis, these relationships are evolved with the full renormalization group down to present experimental energies, yielding predictions for the top quark and Higgs-boson masses, near 155 GeV for the former and near 140 GeV for the latter. In this fashion, fermion-antifermion condensates can be shown to yield a top mass consistent with that indicated from electroweak loop corrections for LEP data. (author) 23 refs
Constraints on the mass spectrum of fourth generation fermions and Higgs bosons
International Nuclear Information System (INIS)
Hashimoto, Michio
2010-01-01
We reanalyze constraints on the mass spectrum of the chiral fourth generation fermions and the Higgs bosons for the standard model (SM4) and the two Higgs doublet model. We find that the Higgs mass in the SM4 should be larger than roughly the fourth generation up-type quark mass, while the light CP even Higgs mass in the two Higgs doublet model can be smaller. Various mass spectra of the fourth generation fermions and the Higgs bosons are allowed. The phenomenology of the fourth generation models is still rich.
Directory of Open Access Journals (Sweden)
Mian Jiang
2018-01-01
Full Text Available Nonlinearity measure is proposed to investigate the influence of slowly varying mass on severity of dynamics nonlinearity of bearing-rotor systems with pedestal looseness. A nonlinear mathematical model including the effect of slowly varying disk mass is developed for a bearing-rotor system with pedestal looseness. The varying of equivalent disk mass is described by a cosine function, and the amplitude coefficient is used as a control parameter. Then, nonlinearity measure is employed to quantify the severity of dynamics nonlinearity of bearing-rotor systems. With the increasing of looseness clearances, the curves that denote the trend of nonlinearity degree are plotted for each amplitude coefficient of mass varying. It can be concluded that larger amplitude coefficients of the disk mass varying will have more influence on the severity of dynamics nonlinearity and generation of chaotic behaviors in rotor systems with pedestal looseness.
Magnetic Generation due to Mass Difference between Charge Carriers
Chen, Shi; Dan, JiaKun; Chen, ZiYu; Li, JianFeng
2013-01-01
The possibility of spontaneous magnetization due to the "asymmetry in mass" of charge carriers in a system is investigated. Analysis shows that when the masses of positive and negative charge carriers are identical, no magnetization is predicted. However, if the masses of two species are different, spontaneous magnetic field would appear, either due to the equipartition of magnetic energy or due to fluctuations together with a feedback mechanism. The conditions for magnetization to occur are ...
High-speed Dynamic Gait Generation Based on Asymmetrization of Impact Posture Using Telescopic Legs
浅野, 文彦
2011-01-01
This paper proposes a novel method for generating a dynamic gait based on anterior-posterior asymmetric impact posture tilting the robo's center of mass forward. The primary purpose of this method is to asymmetrize the impact posture by actuating the robot's telescopic-legs to make overcoming the potential barrier at mid-stance easy, and the mechanical energy is accordingly restored. First, we introduce a planar rimless wheel model with telescopic legs, and investigate the validity of the sta...
Modeling and dynamic simulation of U-tube steam generator
International Nuclear Information System (INIS)
Cui Zhenghua; Jia Dounan; Chen Xuejun; Yu Erjun
1992-01-01
An accurate and simple dynamic mathematical model of U-tube steam generator is presented. It is solved by Adams method and Gear method respectively. The results of this model are in good agreements with that of Kerlin's model which has been validated by the tests. And the two calculating methods are compared
Exotic dynamically generated baryons with negative charm quantum number
Gamermann, D.; Garcia-Recio, C.; Nieves, J.; Salcedo, L. L.; Tolos, L.
2010-01-01
Following a model based on the SU(8) symmetry that treats heavy pseudoscalars and heavy vector mesons on an equal footing, as required by heavy quark symmetry, we study the interaction of baryons and mesons in coupled channels within an unitary approach that generates dynamically poles in the
A SURPRISING DYNAMICAL MASS FOR V773 Tau B
Energy Technology Data Exchange (ETDEWEB)
Boden, Andrew F. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, MS 11-17, Pasadena, CA 91125 (United States); Torres, Guillermo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Duchene, Gaspard [Division of Astronomy and Astrophysics, University of California, Berkeley, CA 94720 (United States); Konopacky, Quinn [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Ghez, A. M. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1562 (United States); Torres, Rosa M. [Argelander-Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany); Loinard, Laurent [Centro de Radiostronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 72-3 (Xangari), 58089 Morelia, Michoacan (Mexico)
2012-03-01
We report on new high-resolution imaging and spectroscopy on the multiple T Tauri star system V773 Tau over the 2003-2009 period. With these data we derive relative astrometry, photometry between the A and B components, and radial velocity (RV) of the A-subsystem components. Combining these new data with previously published astrometry and RVs, we update the relative A-B orbit model. This updated orbit model, the known system distance, and A-subsystem parameters yield a dynamical mass for the B component for the first time. Remarkably, the derived B dynamical mass is in the range 1.7-3.0 M{sub Sun }. This is much higher than previous estimates and suggests that like A, B is also a multiple stellar system. Among these data, spatially resolved spectroscopy provides new insight into the nature of the B component. Similar to A, these near-IR spectra indicate that the dominant source in B is of mid-K spectral type. If B is in fact a multiple star system as suggested by the dynamical mass estimate, the simplest assumption is that B is composed of similar {approx}1.2 M{sub Sun} pre-main-sequence stars in a close (<1 AU) binary system. This inference is supported by line-shape changes in near-IR spectroscopy of B, tentatively interpreted as changing RV among components in V773 Tau B. Relative photometry indicates that B is highly variable in the near-IR. The most likely explanation for this variability is circum-B material resulting in variable line-of-sight extinction. The distribution of this material must be significantly affected by both the putative B multiplicity and the A-B orbit.
Landscape seasons and air mass dynamics in Latvia
International Nuclear Information System (INIS)
Krauklis, A.; Draveniece, A.
2004-01-01
Latvia is located in the middle of an area where the boreal and nemoral zones and the regions of oceanic and continental climate meet, and it was studied as a model territory of the most typical variation of boreo-nemoral ecotone. The subject of this study was seasonal dynamics of the state of landscapes and diachronous links between seasons. It was found that landscapes undergo 12 seasonal states or seasons during the annual cycle of insulation and air mass occurrence. Each season may be distinguished by a definite amount of solar radiation, distinctive state of heat and water balance, phenological state of vegetation, and a distinctive occurrence of different air mass types and their particular 'association'. During each season these variables show a particular combination of numerical values and a distinctive landscape pattern
Dynamical shake-up and the low mass of Mars
Bromley, Benjamin C.; Kenyon, Scott
2017-10-01
The low mass of Mars and the lack of planets in the asteroid belt are important constraints on theories of planet formation. We revisit the idea that sweeping secular resonances involving the gas giants and theSun's dissipating protoplanetary disk can explain these features of our Solar System. To test this "dynamical shake-up" scenario, we perform an extensive suite of simulations to track terrestrial planet formation from planetesimals. We find that if the Sun’s gas disk depletes in roughly a million years, then a sweeping resonance with Jupiter inhibits planet formation in the asteroid belt and substantially limits the mass of Mars. We explore how this phenomenon might lead to asteroid belt analogs around other stars with long-period, massive planets.
Harms, Hendrik Johannes; Stubkjær Hansson, Nils Henrik; Tolbod, Lars Poulsen; Kim, Won Yong; Jakobsen, Steen; Bouchelouche, Kirsten; Wiggers, Henrik; Frøkiaer, Jørgen; Sörensen, Jens
2016-09-01
Dynamic cardiac PET is used to quantify molecular processes in vivo. However, measurements of left ventricular (LV) mass and volume require electrocardiogram-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using nongated dynamic cardiac PET. Thirty-five patients with aortic-valve stenosis and 10 healthy controls underwent a 27-min (11)C-acetate PET/CT scan and cardiac MRI (CMR). The controls were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were generated from nongated dynamic data. Using software-based structure recognition, the LV wall was automatically segmented from K1 images to derive functional assessments of LV mass (mLV) and wall thickness. End-systolic and end-diastolic volumes were calculated using blood pool images and applied to obtain stroke volume and LV ejection fraction (LVEF). PET measurements were compared with CMR. High, linear correlations were found for LV mass (r = 0.95), end-systolic volume (r = 0.93), and end-diastolic volume (r = 0.90), and slightly lower correlations were found for stroke volume (r = 0.74), LVEF (r = 0.81), and thickness (r = 0.78). Bland-Altman analyses showed significant differences for mLV and thickness only and an overestimation for LVEF at lower values. Intra- and interobserver correlations were greater than 0.95 for all PET measurements. PET repeatability accuracy in the controls was comparable to CMR. LV mass and volume are accurately and automatically generated from dynamic (11)C-acetate PET without electrocardiogram gating. This method can be incorporated in a standard routine without any additional workload and can, in theory, be extended to other PET tracers. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.
DYNAMICAL MASS OF THE SUBSTELLAR BENCHMARK BINARY HD 130948BC , ,
International Nuclear Information System (INIS)
Dupuy, Trent J.; Liu, Michael C.; Ireland, Michael J.
2009-01-01
We present Keck adaptive optics imaging of the L4+L4 binary HD 130948BC along with archival Hubble Space Telescope and Gemini North observations, which together span ∼ 70% of the binary's orbital period. From the relative orbit, we determine a total dynamical mass of 0.109 ± 0.003 M sun (114 ± 3 M Jup ). The flux ratio of HD 130948BC is near unity, so both components are unambiguously substellar for any plausible mass ratio. An independent constraint on the age of the system is available from the primary HD 130948A (G2V, [M/H] = 0.0). The ensemble of available indicators suggests an age comparable to Hyades, with the most precise age being 0.79 +0.22 -0.15 Gyr based on gyrochronology. Therefore, HD 130948BC is now a unique benchmark among field L and T dwarfs, with a well-determined mass, luminosity, and age. We find that substellar theoretical models disagree with our observations. (1) Both components of HD 130948BC appear to be overluminous by a factor of ∼ 2-3 times compared to evolutionary models. The age of the system would have to be notably younger than the gyro age to ameliorate the luminosity disagreement. (2) Effective temperatures derived from evolutionary models for HD 130948B and C are inconsistent with temperatures determined from spectral synthesis for objects of similar spectral type. Overall, regardless of the adopted age, evolutionary and atmospheric models give inconsistent results, which indicate systematic errors in at least one class of models, possibly both. The masses of HD 130948BC happen to be very near the theoretical mass limit for lithium burning, and thus measuring the differential lithium depletion between B and C will provide a uniquely discriminating test of theoretical models. The potential underestimate of luminosities by evolutionary models would have wide-ranging implications; therefore, a more refined estimate age for HD 130948A is critically needed.
Topological mass of magnetic Skyrmions probed by ultrafast dynamic imaging
International Nuclear Information System (INIS)
Buettner, Felix
2013-01-01
In this thesis, we investigate the GHz dynamics of skyrmionic spin structures by means of pump-probe dynamic imaging to determine the equation of motion that governs the behavior of these technologically relevant spin structures. To achieve this goal, we first designed and optimized a perpendicular magnetic anisotropy CoB/Pt multilayer material for low magnetic pinning, as required for ultrafast pump-probe imaging experiments. Second, we developed an integrated sample design for X-ray holography capable of tracking relative magnetic positional changes down to 3 nm spatial resolution. These advances enabled us to image the trajectory of a single magnetic Skyrmion. We find that the motion is comprised of two gyrotropic modes, one clockwise and one counterclockwise. The existence of two modes shows that Skyrmions are massive quasiparticles. From their derived frequencies we find an inertial mass for the Skyrmion which is a factor of five larger than expected based on existing models for inertia in magnetism. Our results demonstrate that the mass of Skyrmions is based on a novel mechanism emerging from their confined nature, which is a direct consequence of their topology.
Dynamics of Symmetric Conserved Mass Aggregation Model on Complex Networks
Institute of Scientific and Technical Information of China (English)
HUA Da-Yin
2009-01-01
We investigate the dynamical behaviour of the aggregation process in the symmetric conserved mass aggregation model under three different topological structures. The dispersion σ(t, L) = (∑i(mi - ρ0)2/L)1/2 is defined to describe the dynamical behaviour where ρ0 is the density of particle and mi is the particle number on a site. It is found numerically that for a regular lattice and a scale-free network, σ(t, L) follows a power-law scaling σ(t, L) ～ tδ1 and σ(t, L) ～ tδ4 from a random initial condition to the stationary states, respectively. However, for a small-world network, there are two power-law scaling regimes, σ(t, L) ～ tδ2 when t＜T and a(t, L) ～ tδ3 when tT. Moreover, it is found numerically that δ2 is near to δ1 for small rewiring probability q, and δ3 hardly changes with varying q and it is almost the same as δ4. We speculate that the aggregation of the connection degree accelerates the mass aggregation in the initial relaxation stage and the existence of the long-distance interactions in the complex networks results in the acceleration of the mass aggregation when tT for the small-world networks. We also show that the relaxation time T follows a power-law scaling τ Lz and σ(t, L) in the stationary state follows a power-law σs(L) ～ Lσ for three different structures.
Dynamic modeling and simulation of EBR-II steam generator system
International Nuclear Information System (INIS)
Berkan, R.C.; Upadhyaya, B.R.
1989-01-01
This paper presents a low order dynamic model of the Experimental breeder Reactor-II (EBR-II) steam generator system. The model development includes the application of energy, mass and momentum balance equations in state-space form. The model also includes a three-element controller for the drum water level control problem. The simulation results for low-level perturbations exhibit the inherently stable characteristics of the steam generator. The predictions of test transients also verify the consistency of this low order model
Dynamical gluon masses in perturbative calculations at the loop level
International Nuclear Information System (INIS)
Machado, Fatima A.; Natale, Adriano A.
2013-01-01
Full text: In the phenomenology of strong interactions one always has to deal at some extent with the interplay between perturbative and non-perturbative QCD. On one hand, the former has quite developed tools, yielded by asymptotic freedom. On the other, concerning the latter, we nowadays envisage the following scenario: 1) There are strong evidences for a dynamically massive gluon propagator and infrared finite coupling constant; 2) There is an extensive and successful use of an infrared finite coupling constant in phenomenological calculations at tree level; 3) The infrared finite coupling improves the perturbative series convergence; 4) The dynamical gluon mass provides a natural infrared cutoff in the physical processes at the tree level. Considering this scenario it is natural to ask how these non-perturbative results can be used in perturbative calculations of physical observables at the loop level. Recent papers discuss how off-shell gauge and renormalization group invariant Green functions can be computed with the use of the Pinch Technique (PT), with IR divergences removed by the dynamical gluon mass, and using a well defined effective charge. In this work we improve the former results by the authors, which evaluate 1-loop corrections to some two- and three-point functions of SU(3) pure Yang-Mills, investigating the dressing of quantities that could account for an extension of loop calculations to the infrared domain of the theory, in a way applicable to phenomenological calculations. One of these improvements is maintaining the gluon propagator transverse in such a scheme. (author)
Lou, X.; Dongen, van J.L.J.; Meijer, E.W.
2010-01-01
A simple method was developed for the generation of cesium iodide (CsI) cluster ions up to m/z over 20,000 in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Calibration ions in both positive and negative ion modes can readily be generated from a single MALDI spot of CsI(3)
Dynamic Frames Based Generation of 3D Scenes and Applications
Directory of Open Access Journals (Sweden)
Danijel Radošević
2015-05-01
Full Text Available Modern graphic/programming tools like Unity enables the possibility of creating 3D scenes as well as making 3D scene based program applications, including full physical model, motion, sounds, lightning effects etc. This paper deals with the usage of dynamic frames based generator in the automatic generation of 3D scene and related source code. The suggested model enables the possibility to specify features of the 3D scene in a form of textual specification, as well as exporting such features from a 3D tool. This approach enables higher level of code generation flexibility and the reusability of the main code and scene artifacts in a form of textual templates. An example of the generated application is presented and discussed.
Dynamical generation of maximally entangled states in two identical cavities
International Nuclear Information System (INIS)
Alexanian, Moorad
2011-01-01
The generation of entanglement between two identical coupled cavities, each containing a single three-level atom, is studied when the cavities exchange two coherent photons and are in the N=2,4 manifolds, where N represents the maximum number of photons possible in either cavity. The atom-photon state of each cavity is described by a qutrit for N=2 and a five-dimensional qudit for N=4. However, the conservation of the total value of N for the interacting two-cavity system limits the total number of states to only 4 states for N=2 and 8 states for N=4, rather than the usual 9 for two qutrits and 25 for two five-dimensional qudits. In the N=2 manifold, two-qutrit states dynamically generate four maximally entangled Bell states from initially unentangled states. In the N=4 manifold, two-qudit states dynamically generate maximally entangled states involving three or four states. The generation of these maximally entangled states occurs rather rapidly for large hopping strengths. The cavities function as a storage of periodically generated maximally entangled states.
Effect of heat transfer tube leak on dynamic characteristic of steam generator
International Nuclear Information System (INIS)
Sun Baozhi; Shi Jianxin; Li Na; Zheng Lusong; Liu Shanghua; Lei Yu
2015-01-01
Taking the steam generator of Daya Bay Nuclear Power Station as the research object, one-dimensional dynamic model of the steam generator based on drift flux theory and leak model of heat transfer tube were established. Steady simulation of steam generator under different conditions was carried out. Based on verifying the drift flux model and leak model of heat transfer tube, the effect of leak location and flow rate under different conditions on steam generator's key parameters was studied. The results show that the drift flux model and leak model can reflect the law of key parameter change accurately such as vapor mass fraction and steam pressure under different leak cases. The variation of the parameters is most apparent when the leak is at the entrance of boiling section and vapor mass fraction varies from 0.261 to 0.163 when leakage accounts for 5% of coolant flow rate. The successful prediction of the effect of heat transfer tube leak on dynamic characteristics of the steam generator based on drift flux theory supplies some references for monitoring and taking precautionary measures to prevent heat transfer tube leak accident. (authors)
Directory of Open Access Journals (Sweden)
Alex Pitti
2009-10-01
Full Text Available Pattern generators found in the spinal cords are no more seen as simple rhythmic oscillators for motion control. Indeed, they achieve flexible and dynamical coordination in interaction with the body and the environment dynamics to rise motor synergies. Discovering the mechanisms underlying the control of motor synergies constitute an important research question not only for neuroscience but also for robotics: the motors coordination of high dimensional robotic systems is still a drawback and new control methods based on biological solutions may reduce their overall complexity. We propose to model the flexible combination of motor synergies in embodied systems via partial phase synchronization of distributed chaotic systems; for specific coupling strength, chaotic systems are able to phase synchronize their dynamics to the resonant frequencies of one external force. We take advantage of this property to explore and exploit the intrinsic dynamics of one specified embodied system. In two experiments with bipedal walkers, we show how motor synergies emerge when the controllers phase synchronize to the body’s dynamics, entraining it to its intrinsic behavioral patterns. This stage is characterized by directed information flow from the sensors to the motors exhibiting the optimal situation when the body dynamics drive the controllers (mutual entrainment. Based on our results, we discuss the relevance of our findings for modeling the modular control of distributed pattern generators exhibited in the spinal cords, and for exploring the motor synergies in robots.
Automating the generation of finite element dynamical cores with Firedrake
Ham, David; Mitchell, Lawrence; Homolya, Miklós; Luporini, Fabio; Gibson, Thomas; Kelly, Paul; Cotter, Colin; Lange, Michael; Kramer, Stephan; Shipton, Jemma; Yamazaki, Hiroe; Paganini, Alberto; Kärnä, Tuomas
2017-04-01
The development of a dynamical core is an increasingly complex software engineering undertaking. As the equations become more complete, the discretisations more sophisticated and the hardware acquires ever more fine-grained parallelism and deeper memory hierarchies, the problem of building, testing and modifying dynamical cores becomes increasingly complex. Here we present Firedrake, a code generation system for the finite element method with specialist features designed to support the creation of geoscientific models. Using Firedrake, the dynamical core developer writes the partial differential equations in weak form in a high level mathematical notation. Appropriate function spaces are chosen and time stepping loops written at the same high level. When the programme is run, Firedrake generates high performance C code for the resulting numerics which are executed in parallel. Models in Firedrake typically take a tiny fraction of the lines of code required by traditional hand-coding techniques. They support more sophisticated numerics than are easily achieved by hand, and the resulting code is frequently higher performance. Critically, debugging, modifying and extending a model written in Firedrake is vastly easier than by traditional methods due to the small, highly mathematical code base. Firedrake supports a wide range of key features for dynamical core creation: A vast range of discretisations, including both continuous and discontinuous spaces and mimetic (C-grid-like) elements which optimally represent force balances in geophysical flows. High aspect ratio layered meshes suitable for ocean and atmosphere domains. Curved elements for high accuracy representations of the sphere. Support for non-finite element operators, such as parametrisations. Access to PETSc, a world-leading library of programmable linear and nonlinear solvers. High performance adjoint models generated automatically by symbolically reasoning about the forward model. This poster will present
Radiative generation of quark masses and mixing angles in the two Higgs doublet model
International Nuclear Information System (INIS)
Ibarra, Alejandro; Solaguren-Beascoa, Ana
2014-01-01
We present a framework to generate the quark mass hierarchies and mixing angles by extending the Standard Model with one extra Higgs doublet. The charm and strange quark masses are generated by small quantum effects, thus explaining the hierarchy between the second and third generation quark masses. All the mixing angles are also generated by small quantum effects: the Cabibbo angle is generated at zeroth order in perturbation theory, while the remaining off-diagonal entries of the Cabibbo–Kobayashi–Maskawa matrix are generated at first order, hence explaining the observed hierarchy |V ub |,|V cb |≪|V us |. The values of the radiatively generated parameters depend only logarithmically on the heavy Higgs mass, therefore this framework can be reconciled with the stringent limits on flavor violation by postulating a sufficiently large new physics scale
A Dynamic Wind Generation Model for Power Systems Studies
Estanqueiro, Ana
2007-01-01
In this paper, a wind park dynamic model is presented together with a base methodology for its application to power system studies. This detailed wind generation model addresses the wind turbine components and phenomena more relevant to characterize the power quality of a grid connected wind park, as well as the wind park response to the grid fast perturbations, e.g., low voltage ride through fault. The developed model was applied to the operating conditions of the selected sets of wind turbi...
Automated processing of data generated by molecular dynamics
International Nuclear Information System (INIS)
Lobato Hoyos, Ivan; Rojas Tapia, Justo; Instituto Peruano de Energia Nuclear, Lima
2008-01-01
A new integrated tool for automated processing of data generated by molecular dynamics packages and programs have been developed. The program allows to calculate important quantities such as pair correlation function, the analysis of common neighbors, counting nanoparticles and their size distribution, conversion of output files between different formats. The work explains in detail the modules of the tool, the interface between them. The uses of program are illustrated in application examples in the calculation of various properties of silver nanoparticles. (author)
Steam generator fitted with a dynamic draining device
International Nuclear Information System (INIS)
Chaix, J.E.
1982-01-01
This generator has, at its upper part, at least one drying structure for holding the water carried with the steam and communicating at its lower part with at least one discharge pipe for draining off the water, each pipe communicating with a dynamic draining device capable of creating a depression in order to suck up the water contained in the drying structure. Application is for pressurized water nuclear reactors [fr
Hadron collider tests of neutrino mass-generating mechanisms
Ruiz, Richard Efrain
The Standard Model of particle physics (SM) is presently the best description of nature at small distances and high energies. However, with tiny but nonzero neutrino masses, a Higgs boson mass unstable under radiative corrections, and little guidance on understanding the hierarchy of fermion masses, the SM remains an unsatisfactory description of nature. Well-motivated scenarios that resolve these issues exist but also predict extended gauge (e.g., Left-Right Symmetric Models), scalar (e.g., Supersymmetry), and/or fermion sectors (e.g., Seesaw Models). Hence, discovering such new states would have far-reaching implications. After reviewing basic tenets of the SM and collider physics, several beyond the SM (BSM) scenarios that alleviate these shortcomings are investigated. Emphasis is placed on the production of a heavy Majorana neutrinos at hadron colliders in the context of low-energy, effective theories that simultaneously explain the origin of neutrino masses and their smallness compared to other elementary fermions, the so-called Seesaw Mechanisms. As probes of new physics, rare top quark decays to Higgs bosons in the context of the SM, the Types I and II Two Higgs Doublet Model (2HDM), and the semi-model independent framework of Effective Field Theory (EFT) have also been investigated. Observation prospects and discovery potentials of these models at current and future collider experiments are quantified.
Functional Requirements for the Next Generation of Mass Notification
Trumbo, Berkly
2012-01-01
While the latest update to National Fire Protection Association (NFPA) redefines mass notification as "emergency communications systems" (ECS), the end user community is formulating expectations related to the future functionality of today's alerting solutions. Numerous best practices have surfaced since alerting technology began its rapid,…
Dynamic participation of doubly fed induction generator in automatic generation control
Energy Technology Data Exchange (ETDEWEB)
Bhatt, Praghnesh [Department of Electrical Engineering, Charotar Institute of Technology, Changa, Gujarat-388421 (India); Roy, Ranjit [Department of Electrical Engineering, S.V. National Institute of Technology, Surat, Gujarat-395007 (India); Ghoshal, S.P. [Department of Electrical Engineering, National Institute of Technology, Durgapur, West Bengal-713209 (India)
2011-04-15
Increasing levels of wind generation have resulted in an urgent need for the assessment of their impact on frequency control of power systems. The displacement of conventional generation with wind generation will result in erosion of system frequency. The paper analyzed the dynamic participation of doubly fed induction generator (DFIG) to system frequency responses of two-area interconnected power system having variety of conventional generating units. Frequency control support function responding proportionally to frequency deviation is proposed to take out the kinetic energy of turbine blades in order to improve the frequency response of the system. Impacts of different wind penetrations in the system and varying active power support from wind farm on frequency control have been investigated. Integral gains of AGC loop are optimized through craziness-based particle swarm optimization (CRPSO) in order to have optimal transient responses of area frequencies, tie-line power deviation and DFIG parameters. (author)
Does dynamic stability govern propulsive force generation in human walking?
Browne, Michael G; Franz, Jason R
2017-11-01
Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force ( F P ) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and F P generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their F P according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an F P at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds.
Dynamic Braking System of a Tidal Generator: Preprint
Energy Technology Data Exchange (ETDEWEB)
Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath
2016-08-01
Renewable energy generation has experienced significant cost reductions during the past decades, and it has become more accepted by the global population. In the beginning, wind generation dominated the development and deployment of renewable energy; however, during recent decades, photovoltaic (PV) generation has grown at a very significant pace due to the tremendous decrease in the cost of PV modules. The focus on renewable energy generation has now expanded to include new types with promising future applications, such as river and tidal generation. The input water flow to these types of resources is more predictable than wind or solar generation. The data used in this paper is representative of a typical river or tidal generator. The analysis is based on a generator with a power rating of 40 kW. The tidal generator under consideration is driven by two sets of helical turbines connected to each side of the generator located in between the turbines. The generator is operated in variable speed, and it is controlled to maximize the energy harvested as well as the operation of the turbine generator. The electrical system consists of a three-phase permanent magnet generator connected to a three-phase passive rectifier. The output of the rectifier is connected to a DC-DC converter to match the rectifier output to the DC bus voltage of the DC-AC inverter. The three-phase inverter is connected to the grid, and it is controlled to provide a good interface with the grid. One important aspect of river and tidal generation is the braking mechanism. In a tidal generator, the braking mechanism is important to avoid a runaway condition in case the connection to the grid is lost when there is a fault in the lines. A runaway condition may lead to an overspeed condition and cause extreme stresses on the turbine blade structure and eventual disintegration of the mechanical structure. In this paper, the concept of the dynamic braking system is developed and investigated for normal
Kaufmann, Anton; Walker, Stephan
2017-11-30
The linear intrascan and interscan dynamic ranges of mass spectrometers are important in metabolome and residue analysis. A large linear dynamic range is mandatory if both low- and high-abundance ions have to be detected and quantitated in heavy matrix samples. These performance criteria, as provided by modern high-resolution mass spectrometry (HRMS), were systematically investigated. The comparison included two generations of Orbitraps, and an ion mobility quadrupole time-of-flight (QTOF) system In addition, different scan modes, as provided by the utilized instruments, were investigated. Calibration curves of different compounds covering a concentration range of five orders of magnitude were measured to evaluate the linear interscan dynamic range. The linear intrascan dynamic range and the resulting mass accuracy were evaluated by repeating these measurements in the presence of a very intense background. Modern HRMS instruments can show linear dynamic ranges of five orders of magnitude. Often, however, the linear dynamic range is limited by the detection capability (sensitivity and selectivity) and by the electrospray ionization. Orbitraps, as opposed to TOF instruments, show a reduced intrascan dynamic range. This is due to the limited C-trap and Orbitrap capacity. The tested TOF instrument shows poorer mass accuracies than the Orbitraps. In contrast, hyphenation with an ion-mobility device seems not to affect the linear dynamic range. The linear dynamic range of modern HRMS instrumentation has been significantly improved. This also refers to the virtual absence of systematic mass shifts at high ion abundances. The intrascan dynamic range of the current Orbitrap technology may still be a limitation when analyzing complex matrix extracts. On the other hand, the linear dynamic range is not only limited by the detector technology, but can also be shortened by peripheral devices, where the ionization and transfer of ions take place. Copyright © 2017 John Wiley
Exploring effects of strong interactions in enhancing masses of dynamical origin
International Nuclear Information System (INIS)
Cabo Montes de Oca, Alejandro
2011-01-01
A previous study of the dynamical generation of masses in massless QCD is considered from another viewpoint. The quark mass is assumed to have a dynamical origin and is substituted for by a scalar field without self-interaction. The potential for the new field background is evaluated up to two loops. Expressing the running coupling in terms of the scale parameter μ, the potential minimum is chosen to fix m top =175 GeV when μ 0 =498 MeV. The second derivative of the potential predicts a scalar field mass of 126.76 GeV. This number is close to the value 114 GeV, which preliminary data taken at CERN suggested to be associated with the Higgs particle. However, the simplifying assumptions limit the validity of the calculations done, as indicated by the large value of α=(g 2 )/(4π)=1.077 obtained. However, supporting statements about the possibility of improving the scheme come from the necessary inclusion of weak and scalar field couplings and mass counterterms in the renormalization procedure, in common with the seemingly needed consideration of the massive W and Z fields, if the real conditions of the SM model are intended to be approached. (orig.)
Procedural generation of aesthetic patterns from dynamics and iteration processes
Directory of Open Access Journals (Sweden)
Gdawiec Krzysztof
2017-12-01
Full Text Available Aesthetic patterns are widely used nowadays, e.g., in jewellery design, carpet design, as textures and patterns on wallpapers, etc. Most of the work during the design stage is carried out by a designer manually. Therefore, it is highly useful to develop methods for aesthetic pattern generation. In this paper, we present methods for generating aesthetic patterns using the dynamics of a discrete dynamical system. The presented methods are based on the use of various iteration processes from fixed point theory (Mann, S, Noor, etc. and the application of an affine combination of these iterations. Moreover, we propose new convergence tests that enrich the obtained patterns. The proposed methods generate patterns in a procedural way and can be easily implemented on the GPU. The presented examples show that using the proposed methods we are able to obtain a variety of interesting patterns. Moreover, the numerical examples show that the use of the GPU implementation with shaders allows the generation of patterns in real time and the speed-up (compared with a CPU implementation ranges from about 1000 to 2500 times.
Dynamic cluster generation for a fuzzy classifier with ellipsoidal regions.
Abe, S
1998-01-01
In this paper, we discuss a fuzzy classifier with ellipsoidal regions that dynamically generates clusters. First, for the data belonging to a class we define a fuzzy rule with an ellipsoidal region. Namely, using the training data for each class, we calculate the center and the covariance matrix of the ellipsoidal region for the class. Then we tune the fuzzy rules, i.e., the slopes of the membership functions, successively until there is no improvement in the recognition rate of the training data. Then if the number of the data belonging to a class that are misclassified into another class exceeds a prescribed number, we define a new cluster to which those data belong and the associated fuzzy rule. Then we tune the newly defined fuzzy rules in the similar way as stated above, fixing the already obtained fuzzy rules. We iterate generation of clusters and tuning of the newly generated fuzzy rules until the number of the data belonging to a class that are misclassified into another class does not exceed the prescribed number. We evaluate our method using thyroid data, Japanese Hiragana data of vehicle license plates, and blood cell data. By dynamic cluster generation, the generalization ability of the classifier is improved and the recognition rate of the fuzzy classifier for the test data is the best among the neural network classifiers and other fuzzy classifiers if there are no discrete input variables.
International Nuclear Information System (INIS)
Dudal, D.; Verschelde, H.; Gracey, J.A.; Lemes, V.E.R.; Sobreiro, R.F.; Sorella, S.P.; Sarandy, M.S.
2004-01-01
We investigate a dynamical mass generation mechanism for the off-diagonal gluons and ghosts in SU(N) Yang-Mills theories, quantized in the maximal Abelian gauge. Such a mass can be seen as evidence for the Abelian dominance in that gauge. It originates from the condensation of a mixed gluon-ghost operator of mass dimension two, which lowers the vacuum energy. We construct an effective potential for this operator by a combined use of the local composite operators technique with the algebraic renormalization and we discuss the gauge parameter independence of the results. We also show that it is possible to connect the vacuum energy, due to the mass dimension-two condensate discussed here, with the nontrivial vacuum energy originating from the condensate μ 2 >, which has attracted much attention in the Landau gauge
Kuhl, Thorsten
2014-01-01
The origin of fundamental particle mass remains one of the key topics for particle physics at the LHC, even after the discovery of the Higgs. Because of the relatively low Higgs Boson mass, uncertainty remains as to whether the Standard Model (SM) can actually describe all Higgs related observations, or whether a theory beyond the SM will be required. The largest deviations from the SM can be expected to be observed in couplings of the most massive Standard Model particle, the top quark, to t...
Moduli stabilization and uplifting with dynamically generated F-terms
International Nuclear Information System (INIS)
Dudas, Emilian; Papineau, Chloe; Pokorski, Stefan
2007-01-01
We use the F-term dynamical supersymmetry breaking models with metastable vacua in order to uplift the vacuum energy in the KKLT moduli stabilization scenario. The main advantage compared to earlier proposals is the manifest supersymmetric treatment and the natural coexistence of a TeV gravitino mass with a zero cosmological constant. We argue that it is generically difficult to avoid anti de-Sitter supersymmetric minima, however the tunneling rate from the metastable vacuum with zero vacuum energy towards them can be very suppressed. We briefly comment on the properties of the induced soft terms in the observable sector
Moduli stabilization and uplifting with dynamically generated F-terms
Energy Technology Data Exchange (ETDEWEB)
Dudas, Emilian [CERN Theory Division, CH-1211, Geneva 23 (Switzerland); Papineau, Chloe [CPhT, Ecole Polytechnique, F-91128 Palaiseau Cedex (France); Pokorski, Stefan [Institute of Theoretical Physics, Univ. of Warsaw, 00-681 Warsaw (Poland)
2007-02-15
We use the F-term dynamical supersymmetry breaking models with metastable vacua in order to uplift the vacuum energy in the KKLT moduli stabilization scenario. The main advantage compared to earlier proposals is the manifest supersymmetric treatment and the natural coexistence of a TeV gravitino mass with a zero cosmological constant. We argue that it is generically difficult to avoid anti de-Sitter supersymmetric minima, however the tunneling rate from the metastable vacuum with zero vacuum energy towards them can be very suppressed. We briefly comment on the properties of the induced soft terms in the observable sector.
International Nuclear Information System (INIS)
Phillips, Carolyn L.; Anderson, Joshua A.; Glotzer, Sharon C.
2011-01-01
Highlights: → Molecular Dynamics codes implemented on GPUs have achieved two-order of magnitude computational accelerations. → Brownian Dynamics and Dissipative Particle Dynamics simulations require a large number of random numbers per time step. → We introduce a method for generating small batches of pseudorandom numbers distributed over many threads of calculations. → With this method, Dissipative Particle Dynamics is implemented on a GPU device without requiring thread-to-thread communication. - Abstract: Brownian Dynamics (BD), also known as Langevin Dynamics, and Dissipative Particle Dynamics (DPD) are implicit solvent methods commonly used in models of soft matter and biomolecular systems. The interaction of the numerous solvent particles with larger particles is coarse-grained as a Langevin thermostat is applied to individual particles or to particle pairs. The Langevin thermostat requires a pseudo-random number generator (PRNG) to generate the stochastic force applied to each particle or pair of neighboring particles during each time step in the integration of Newton's equations of motion. In a Single-Instruction-Multiple-Thread (SIMT) GPU parallel computing environment, small batches of random numbers must be generated over thousands of threads and millions of kernel calls. In this communication we introduce a one-PRNG-per-kernel-call-per-thread scheme, in which a micro-stream of pseudorandom numbers is generated in each thread and kernel call. These high quality, statistically robust micro-streams require no global memory for state storage, are more computationally efficient than other PRNG schemes in memory-bound kernels, and uniquely enable the DPD simulation method without requiring communication between threads.
Comparative analysis for low-mass and low-inertia dynamic balancing of mechanisms
van der Wijk, V.; Demeulenaere, B.; Gosselin, C.M.; Herder, Justus Laurens
2012-01-01
Dynamic balance is an important feature of high speed mechanisms and robotics that need to minimize vibrations of the base. The main disadvantage of dynamic balancing, however, is that it is accompanied with a considerable increase in mass and inertia. Aiming at low-mass and low-inertia dynamic
Dynamic study of steam generation from low-grade waste heat in a zeolite–water adsorption heat pump
International Nuclear Information System (INIS)
Xue, Bing; Meng, Xiangrui; Wei, Xinli; Nakaso, Koichi; Fukai, Jun
2015-01-01
A novel zeolite–water adsorption heat pump system based on a direct-contact heat exchange method to generate steam from low-grade waste gas and water has been proposed and examined experimentally. Superheated steam (200 °C, 0.1 MPa) is generated from hot water (70–80 °C) and dry air (100–130 °C). A dynamic model for steam generation process is developed to describe local mass and heat transfer. This model features a three-phase calculation and a moving water–gas interface. The calculations are carried out in the zeolite–water and zeolite–gas regions. Model outputs are compared with experimental results for validation. The thermal response inside the reactor and mass of steam generated is well predicted. Numerical results show that preheat process with low-temperature steam is an effective method to achieve local equilibrium quickly, thus generation process is enhanced by prolonging the time and increasing mass of the generated steam. Besides, high-pressure steam generation up to 0.5 MPa is possible from the validated dynamic model. Future work could be emphasized on enhancing high-pressure steam generation with preheat process or mass recovery operation
Generation and dynamics of quadratic birefringent spatial gap solitons
International Nuclear Information System (INIS)
Anghel-Vasilescu, P.; Dorignac, J.; Geniet, F.; Leon, J.; Taki, A.
2011-01-01
A method is proposed to generate and study the dynamics of spatial light solitons in a birefringent medium with quadratic nonlinearity. Although no analytical expression for propagating solitons has been obtained, our numerical simulations show the existence of stable localized spatial solitons in the frequency forbidden band gap of the medium. The dynamics of these objects is quite rich and manifests for instance elastic reflections, or inelastic collisions where two solitons merge and propagate as a single solitary wave. We derive the dynamics of the slowly varying envelopes of the three fields (second harmonic pump and two-component signal) and study this new system theoretically. We show that it does present a threshold for nonlinear supratransmission that can be calculated from a series expansion approach with a very high accuracy. Specific physical implications of our theoretical predictions are illustrated on LiGaTe 2 (LGT) crystals. Once irradiated by a cw laser beam of 10 μm wavelength, at an incidence beyond the extinction angle, such crystals will transmit light, in the form of spatial solitons generated in the nonlinear regime above the nonlinear supratransmission threshold.
Generation of monoenergetic ion beams via ionization dynamics (Conference Presentation)
Lin, Chen; Kim, I. Jong; Yu, Jinqing; Choi, Il Woo; Ma, Wenjun; Yan, Xueqing; Nam, Chang Hee
2017-05-01
The research on ion acceleration driven by high intensity laser pulse has attracted significant interests in recent decades due to the developments of laser technology. The intensive study of energetic ion bunches is particularly stimulated by wide applications in nuclear fusion, medical treatment, warm dense matter production and high energy density physics. However, to implement such compact accelerators, challenges are still existing in terms of beam quality and stability, especially in applications that require higher energy and narrow bandwidth spectra ion beams. We report on the acceleration of quasi-mono-energetic ion beams via ionization dynamics in the interaction of an intense laser pulse with a solid target. Using ionization dynamics model in 2D particle-in-cell (PIC) simulations, we found that high charge state contamination ions can only be ionized in the central spot area where the intensity of sheath field surpasses their ionization threshold. These ions automatically form a microstructure target with a width of few micron scale, which is conducive to generate mono-energetic beams. In the experiment of ultraintense (< 10^21 W/cm^2) laser pulses irradiating ultrathin targets each attracted with a contamination layer of nm-thickness, high quality < 100 MeV mono-energetic ion bunches are generated. The peak energy of the self-generated micro-structured target ions with respect to different contamination layer thickness is also examined This is relatively newfound respect, which is confirmed by the consistence between experiment data and the simulation results.
The effect of dynamical quark mass on the calculation of a strange quark star's structure
Institute of Scientific and Technical Information of China (English)
Gholam Hossein Bordbar; Babak Ziaei
2012-01-01
We discuss the dynamical behavior of strange quark matter components,in particular the effects of density dependent quark mass on the equation of state of strange quark matter.The dynamical masses of quarks are computed within the Nambu-Jona-Lasinio model,then we perform strange quark matter calculations employing the MIT bag model with these dynamical masses.For the sake of comparing dynamical mass interaction with QCD quark-quark interaction,we consider the one-gluon-exchange term as the effective interaction between quarks for the MIT bag model.Our dynamical approach illustrates an improvement in the obtained equation of state values.We also investigate the structure of the strange quark star using TolmanOppenheimer-Volkoff equations for all applied models.Our results show that dynamical mass interaction leads to lower values for gravitational mass.
Dynamic evaluation of the levelized cost of wind power generation
International Nuclear Information System (INIS)
Díaz, Guzmán; Gómez-Aleixandre, Javier; Coto, José
2015-01-01
Highlights: • Conventional levelized cost of energy is static and does not consider flexibility. • This paper defines a dynamic version by means of stochastic programming. • A penalty for early exercising is proposed to differentiate static and dynamic. • Results show the effects of feed-in tariff support in low wind sites. • Policy implications are derived on the basis of the static and dynamic measures. - Abstract: This paper discusses an alternative computation method of the levelized cost of energy of distributed wind power generators. Unlike in the conventional procedures, it includes time of commencement as an optimization variable. For that purpose, a methodology from Longstaff and Schwartz’s dynamic program for pricing financial American options is derived, which provides the ability to find the optimum time and value while coping with uncertainty revenues from energy sales and variable capital costs. The results obtained from the analysis of wind records of 50 sites entail that the conventional levelized cost of energy can be broken down into an optimum, minimum (time-dependent) value and a penalty for early exercising, which can be employed to define investment strategies and support policies
Dynamic Analysis and Test Results for an STC Stirling Generator
Qiu, Songgang; Peterson, Allen A.
2004-02-01
Long-life, high-efficiency generators based on free-piston Stirling machines are a future energy-conversion solution for both space and commercial applications. To aid in design and system integration efforts, Stirling Technology Company (STC) has developed dynamic simulation models for the internal moving subassemblies and for complete Stirling convertor assemblies. These dynamic models have been validated using test data from operating prototypes. Simplified versions of these models are presented to help explain the operating characteristics of the Stirling convertor. Power spectrum analysis is presented for the test data for casing acceleration, piston motion, displacer motion, and controller current/voltage during full power operation. The harmonics of a Stirling convertor and its moving components are identified for the STC zener-diode control scheme. The dynamic behavior of each moving component and its contribution to the system dynamics and resultant vibration forces are discussed. Additionally, the effects of a passive balancer and external suspension are predicted by another simplified system model.
Power and mass optimization of the hybrid solar panel and thermoelectric generators
International Nuclear Information System (INIS)
Kwan, Trevor Hocksun; Wu, Xiaofeng
2016-01-01
Highlights: • The dynamics of the hybrid PV/TEG system operating in outer space is studied. • A generalized thermodynamic model of the hybrid PV/TEG system is given. • This model is then simplified to consider the outer space scenario. • The design of the hybrid PV/TEG system is optimized using the NSGA-II algorithm. • The optimized hybrid system is more efficient than its monolithic counterparts. - Abstract: The thermoelectric generator (TEG) has been widely considered as an electrical power source in many ground applications because of its clean and noiseless characteristics. Moreover, the hybrid photovoltaic cell and TEG (PV/TEG) system has also received wide attention due to its improved power conversion efficiency over its monolithic counterparts. This paper presents a study of the dynamics and the operation of the hybrid PV/TEG system in an outer space environment where a unified thermodynamic model of this system is presented. Moreover, the multi-objective NSGA-II genetic algorithm is utilized to optimize the design of the TEG both in terms of optimal output power and in terms of mass. Specifically, the design of the single stage and the two stage variant of the aforementioned TEG are considered. Simulation results indicate that the optimized PV/TEG system does indeed achieve better efficiencies than that of the monolithic counterparts. Furthermore, it is shown that the single stage TEG is more beneficial than the two stage TEG in terms of achieving optimal performance.
Generation and Application of Virtual Dynamic Learning Environments
Directory of Open Access Journals (Sweden)
Esther Zaretsky
2009-04-01
Full Text Available The generation of virtual dynamic learning environments by mental imagery improved physical education of student teachers. Up-to-date studies showed that training computerized simulations improved spatial abilities, especially visualization of the body's movements in space, and enhanced academic achievements. The main program of the research concentrated on creating teaching units focusing on a variety of physical skills through computerized dynamic presentations. The findings showed that as the student teachers practiced the creation of simulations through the PowerPoint Software, it became clear to them how the computer is related to physical activities. Consequently their presentations became highly animated, and applied to the natural environment. The student teachers applied their presentations in their practical classroom and reported about their pupils' progress in physical skills. Moreover the motivation of the student teachers and pupils to both modes of learning, manipulating virtually and physically, was enhanced.
Light hadrons from Nf=2+1+1 dynamical twisted mass fermions
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
Dynamic generation of light states with discrete symmetries
Cordero, S.; Nahmad-Achar, E.; Castaños, O.; López-Peña, R.
2018-01-01
A dynamic procedure is established within the generalized Tavis-Cummings model to generate light states with discrete point symmetries, given by the cyclic group Cn. We consider arbitrary dipolar coupling strengths of the atoms with a one-mode electromagnetic field in a cavity. The method uses mainly the matter-field entanglement properties of the system, which can be extended to any number of three-level atoms. An initial state constituted by the superposition of two states with definite total excitation numbers, |ψ〉 M1,and |ψ〉 M 2, is considered. It can be generated by the proper selection of the time of flight of an atom passing through the cavity. We demonstrate that the resulting Husimi function of the light is invariant under cyclic point transformations of order n =| M1-M2| .
Adaptive Dynamic Surface Control for Generator Excitation Control System
Directory of Open Access Journals (Sweden)
Zhang Xiu-yu
2014-01-01
Full Text Available For the generator excitation control system which is equipped with static var compensator (SVC and unknown parameters, a novel adaptive dynamic surface control scheme is proposed based on neural network and tracking error transformed function with the following features: (1 the transformation of the excitation generator model to the linear systems is omitted; (2 the prespecified performance of the tracking error can be guaranteed by combining with the tracking error transformed function; (3 the computational burden is greatly reduced by estimating the norm of the weighted vector of neural network instead of the weighted vector itself; therefore, it is more suitable for the real time control; and (4 the explosion of complicity problem inherent in the backstepping control can be eliminated. It is proved that the new scheme can make the system semiglobally uniformly ultimately bounded. Simulation results show the effectiveness of this control scheme.
Generation of diurnal variation for influent data for dynamic simulation.
Langergraber, G; Alex, J; Weissenbacher, N; Woerner, D; Ahnert, M; Frehmann, T; Halft, N; Hobus, I; Plattes, M; Spering, V; Winkler, S
2008-01-01
When using dynamic simulation for fine tuning of the design of activated sludge (AS) plants diurnal variations of influent data are required. For this application usually only data from the design process and no measured data are available. In this paper a simple method to generate diurnal variations of wastewater flow and concentrations is described. The aim is to generate realistic influent data in terms of flow, concentrations and TKN/COD ratios and not to predict the influent of the AS plant in detail. The work has been prepared within the framework of HSG-Sim (Hochschulgruppe Simulation, http://www.hsgsim.org), a group of researchers from Germany, Austria, Luxembourg, Poland, the Netherlands and Switzerland. (c) IWA Publishing 2008.
Fondell, Thomas F.; Flint, Paul L.; Schmutz, Joel A.; Schamber, Jason L.; Nicolai, Christopher A.
2013-01-01
Birds employ varying strategies to accommodate the energetic demands of moult, one important example being changes in body mass. To understand better their physiological and ecological significance, we tested three hypotheses concerning body mass dynamics during moult. We studied Black Brant in 2006 and 2007 moulting at three sites in Alaska which varied in food availability, breeding status and whether geese undertook a moult migration. First we predicted that if mass loss during moult were simply the result of inadequate food resources then mass loss would be highest where food was least available. Secondly, we predicted that if mass loss during moult were adaptive, allowing birds to reduce activity during moult, then birds would gain mass prior to moult where feeding conditions allowed and mass loss would be positively related to mass at moult initiation. Thirdly, we predicted that if mass loss during moult were adaptive, allowing birds to regain flight sooner, then across sites and groups, mass at the end of the flightless period would converge on a theoretical optimum, i.e. the mass that permits the earliest possible return to flight. Mass loss was greatest where food was most available and thus our results did not support the prediction that mass loss resulted from inadequate food availability. Mass at moult initiation was positively related to both food availability and mass loss. In addition, among sites and years, variation in mass was high at moult initiation but greatly reduced at the end of the flightless period, appearing to converge. Thus, our results supported multiple predictions that mass loss during moult was adaptive and that the optimal moulting strategy was to gain mass prior to the flightless period, then through behavioural modifications use these body reserves to reduce activity and in so doing also reduce wing loading. Geese that undertook a moult migration initiated moult at the highest mass, indicating that they were more than able to
Dynamics of microresonator frequency comb generation: models and stability
Directory of Open Access Journals (Sweden)
Hansson Tobias
2016-06-01
Full Text Available Microresonator frequency combs hold promise for enabling a new class of light sources that are simultaneously both broadband and coherent, and that could allow for a profusion of potential applications. In this article, we review various theoretical models for describing the temporal dynamics and formation of optical frequency combs. These models form the basis for performing numerical simulations that can be used in order to better understand the comb generation process, for example helping to identify the universal combcharacteristics and their different associated physical phenomena. Moreover, models allow for the study, design and optimization of comb properties prior to the fabrication of actual devices. We consider and derive theoretical formalisms based on the Ikeda map, the modal expansion approach, and the Lugiato-Lefever equation. We further discuss the generation of frequency combs in silicon resonators featuring multiphoton absorption and free-carrier effects. Additionally, we review comb stability properties and consider the role of modulational instability as well as of parametric instabilities due to the boundary conditions of the cavity. These instability mechanisms are the basis for comprehending the process of frequency comb formation, for identifying the different dynamical regimes and the associated dependence on the comb parameters. Finally, we also discuss the phenomena of continuous wave bi- and multistability and its relation to the observation of mode-locked cavity solitons.
ECONOMIC ASPECTS OF MASS-MEDIA AND THE CHANGES GENERATED BY THE ECONOMIC CRISIS
TRAIAN ALEXANDRU NASTASE
2011-01-01
In this paper we intend to describe the economic implications of mass-media in correlation with the recent socio-economic changes generated by the economic crisis. We take into consideration the dual market on which mass-media evolves: the mass-media products market, and the advertising market, keeping in mind that the behavior of a mass-media institution on one market, can have direct implication on the other market. We analyze the relation between mass-media and the public (audience), the c...
Research on Generating Method of Embedded Software Test Document Based on Dynamic Model
Qu, MingCheng; Wu, XiangHu; Tao, YongChao; Liu, Ying
2018-03-01
This paper provides a dynamic model-based test document generation method for embedded software that provides automatic generation of two documents: test requirements specification documentation and configuration item test documentation. This method enables dynamic test requirements to be implemented in dynamic models, enabling dynamic test demand tracking to be easily generated; able to automatically generate standardized, standardized test requirements and test documentation, improved document-related content inconsistency and lack of integrity And other issues, improve the efficiency.
Analysis of electrocautery generated smoke by chromatographic-mass spectrometry.
Kalil, Jefferson; Pessine, Francisco B T; Fidelis, Carlos H V; Menezes, Fabio H; Palma, Paulo Cesar Rodrigues
2016-01-01
to analyze the chemical components of the smoke from electrocautery from coagulating muscle and liver tissues of pigs. we collected smoke produced by electrocautery applied to porcine tissue in previously evacuated bottles, with qualitative and quantitative analysis of the compounds present through the hyphenated technique gas chromatography / mass spectrometry. there was a majority of decanal aldehyde in the fumes from the subcutaneous, muscle and liver tissues. Fumes of subcutaneous and muscular tissues also showed the presence of hexanal and phenol. In the fumes of subcutaneous and liver tissues we also found toluene and limonene and, finally, nonanal smoke was present in the muscle and liver tissues. there is increasing evidence showing that smoke from electrocautery used in subcutaneous, muscle and liver tissue is harmful to human health. Thus, there is need to reduce exposure to it or wear masks with filters capable of retaining these particles. analisar quimicamente os componentes da fumaça do eletrocautério, provenientes da coagulação de tecidos, muscular e hepático de suino. coleta de fumaça produzida por eletrocauterização de tecido porcino em frascos previamente evacuados com análise qualitativa e quantitativa dos compostos presentes, através de técnica hifenada, cromatografia a gás/espectrometria de massas. houve presença majoritária do aldeído decanal nas fumaças provenientes dos tecidos subcutâneo, muscular e hepático. Fumaças dos tecidos subcutâneo e muscular mostraram também a presença de hexanal e fenol. Nas fumaças dos tecidos subcutâneo e hepático foram encontrados ainda tolueno e limoneno e, por fim, nonanal estava presente nas fumaças dos tecidos muscular e hepático. há número crescente de evidências mostrando que fumaça proveniente de eletrocauterização de tecidos subcutâneo, muscular e hepático é nociva à saúde de seres humanos. Portanto, há necessidade de reduzir a exposição a ela ou usar máscara com
Dynamic simulation of a steam generator by neural networks
International Nuclear Information System (INIS)
Masini, R.; Padovani, E.; Ricotti, M.E.; Zio, E.
1999-01-01
Numerical simulation by computers of the dynamic evolution of complex systems and components is a fundamental phase of any modern engineering design activity. This is of particular importance for risk-based design projects which require that the system behavior be analyzed under several and often extreme conditions. The traditional methods of simulation typically entail long, iterative, processes which lead to large simulation times, often exceeding the transients real time. Artificial neural networks (ANNs) may be exploited in this context, their advantages residing mainly in the speed of computation, in the capability of generalizing from few examples, in the robustness to noisy and partially incomplete data and in the capability of performing empirical input-output mapping without complete knowledge of the underlying physics. In this paper we present a novel approach to dynamic simulation by ANNs based on a superposition scheme in which a set of networks are individually trained, each one to respond to a different input forcing function. The dynamic simulation of a steam generator is considered as an example to show the potentialities of this tool and to point out the difficulties and crucial issues which typically arise when attempting to establish an efficient neural network simulator. The structure of the networks system is such to feedback, at each time step, a portion of the past evolution of the transient and this allows a good reproduction of also non-linear dynamic behaviors. A nice characteristic of the approach is that the modularization of the training reduces substantially its burden and gives this neural simulation tool a nice feature of transportability. (orig.)
Phillips, Carolyn L.; Anderson, Joshua A.; Glotzer, Sharon C.
2011-08-01
Brownian Dynamics (BD), also known as Langevin Dynamics, and Dissipative Particle Dynamics (DPD) are implicit solvent methods commonly used in models of soft matter and biomolecular systems. The interaction of the numerous solvent particles with larger particles is coarse-grained as a Langevin thermostat is applied to individual particles or to particle pairs. The Langevin thermostat requires a pseudo-random number generator (PRNG) to generate the stochastic force applied to each particle or pair of neighboring particles during each time step in the integration of Newton's equations of motion. In a Single-Instruction-Multiple-Thread (SIMT) GPU parallel computing environment, small batches of random numbers must be generated over thousands of threads and millions of kernel calls. In this communication we introduce a one-PRNG-per-kernel-call-per-thread scheme, in which a micro-stream of pseudorandom numbers is generated in each thread and kernel call. These high quality, statistically robust micro-streams require no global memory for state storage, are more computationally efficient than other PRNG schemes in memory-bound kernels, and uniquely enable the DPD simulation method without requiring communication between threads.
Energy Technology Data Exchange (ETDEWEB)
Saiz, Fernan [Department of Chemistry, Imperial College of Science, Technology and Medicine, South Kensington, London, SW7 2A7 (United Kingdom); Gamero-Castaño, Manuel, E-mail: mgameroc@uci.edu [Department of Mechanical and Aerospace Engineering, University of California, Irvine, California, 92697 (United States)
2016-06-15
The impact of electrosprayed nanodroplets on ceramics at several km/s alters the atomic order of the target, causing sputtering, surface amorphization and cratering. The molecular mass of the projectile is known to have a strong effect on the impact phenomenology, and this article aims to rationalize this dependency using molecular dynamics. To achieve this goal, the article models the impact of four projectiles with molecular masses between 45 and 391 amu, and identical diameters and kinetic energies, 10 nm and 63 keV, striking a silicon target. In agreement with experiments, the simulations show that the number of sputtered atoms strongly increases with molecular mass. This is due to the increasing intensity of collision cascades with molecular mass: when the fixed kinetic energy of the projectile is distributed among fewer, more massive molecules, their collisions with the target produce knock-on atoms with higher energies, which in turn generate more energetic and larger numbers of secondary and tertiary knock-on atoms. The more energetic collision cascades intensify both knock-on sputtering and, upon thermalization, thermal sputtering. Besides enhancing sputtering, heavier molecules also increase the fraction of the projectile’s energy that is transferred to the target, as well as the fraction of this energy that is dissipated.
International Nuclear Information System (INIS)
Saiz, Fernan; Gamero-Castaño, Manuel
2016-01-01
The impact of electrosprayed nanodroplets on ceramics at several km/s alters the atomic order of the target, causing sputtering, surface amorphization and cratering. The molecular mass of the projectile is known to have a strong effect on the impact phenomenology, and this article aims to rationalize this dependency using molecular dynamics. To achieve this goal, the article models the impact of four projectiles with molecular masses between 45 and 391 amu, and identical diameters and kinetic energies, 10 nm and 63 keV, striking a silicon target. In agreement with experiments, the simulations show that the number of sputtered atoms strongly increases with molecular mass. This is due to the increasing intensity of collision cascades with molecular mass: when the fixed kinetic energy of the projectile is distributed among fewer, more massive molecules, their collisions with the target produce knock-on atoms with higher energies, which in turn generate more energetic and larger numbers of secondary and tertiary knock-on atoms. The more energetic collision cascades intensify both knock-on sputtering and, upon thermalization, thermal sputtering. Besides enhancing sputtering, heavier molecules also increase the fraction of the projectile’s energy that is transferred to the target, as well as the fraction of this energy that is dissipated.
Some Fluid Dynamic Effects in Large-Scale MHD Generators
Energy Technology Data Exchange (ETDEWEB)
Hunt, J. C.R. [University of Warwick, Coventry (United Kingdom)
1966-10-15
At the present time we are unable to carry out a complete analysis of the fluid dynamics and electrodynamics of an MHD generator. However, various aspects of the behaviour of an MHD generator may be examined by the use of simplified models, for example: (1) one-dimensional gas dynamics (Louis et al. 1964); (2) the current distribution can be found if the velocity is assumed constant across the duct (Witalis, 1965); (3) the skin friction and heat transfer to the walls can be calculated by boundary layer analysis if the flow is assumed to be laminar (Kerrebrock, 1961), and (4) a complete description of the velocity and current distribution across the duct can be given if the flow is assumed to be uniform, laminar, incompressible and not varying in the flow direction (Hunt and Stewartson, 1965). Taken together, these and other models will enable us to describe most of the effects in an MHD generator. In this paper another simplification is considered in which the electromagnetic forces are assumed to be much larger than the inertial forces. The ratio of these two forces is measured by the parameter, S = aB{sup 2}{sub 0}d/pU, where o is the conductivity, B{sub 0} the magnetic field, d the width of the duct, p the density and U the mean velocity. Thus S >> 1. We also assume that the magnetic Reynolds number is very much less than one. In the largest experimental generators now being built S {approx} 2 . Thus, though the results of this model are not immediately applicable, they should indicate the effects of increasing the magnetic field strength and the size of MHD generators. When S >> 1, one can can consider the duct to be divided into 2 regions: (1) a core region where electromagnetic forces are balanced by the pressure gradient and where inertial as well as viscous forces are negligible, and (2) boundary layers on the walls where again inertial forces are negligible but where the viscous, electromagnetic and pressure forces are of the same order. We show how it is
A computational model to generate simulated three-dimensional breast masses
Energy Technology Data Exchange (ETDEWEB)
Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N., E-mail: wernick@iit.edu [Medical Imaging Research Center, Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Schmidt, Robert A. [Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Nishikawa, Robert M. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)
2015-02-15
Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and
A computational model to generate simulated three-dimensional breast masses
International Nuclear Information System (INIS)
Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N.; Schmidt, Robert A.; Nishikawa, Robert M.
2015-01-01
Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and
On the gauge (in)dependence of the dynamical quark mass
International Nuclear Information System (INIS)
Reinders, L.J.; Stam, K.
1987-04-01
We compute the contribution of the mixed quark-gluon condensate to the quark self-energy to all orders in the dynamical quark mass. We investigate the consistency of different expansion schemes. It is found that nonabelian interactions form an obstruction to defining a true dynamical gauge independent mass shell. (orig.)
Steam Generator control in Nuclear Power Plants by water mass inventory
Energy Technology Data Exchange (ETDEWEB)
Dong Wei [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States); Doster, J. Michael [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)], E-mail: doster@eos.ncsu.edu; Mayo, Charles W. [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)
2008-04-15
Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.
Steam Generator control in Nuclear Power Plants by water mass inventory
International Nuclear Information System (INIS)
Dong Wei; Doster, J. Michael; Mayo, Charles W.
2008-01-01
Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators
Generating high-speed dynamic running gaits in a quadruped robot using an evolutionary search.
Krasny, Darren P; Orin, David E
2004-08-01
Over the past several decades, there has been a considerable interest in investigating high-speed dynamic gaits for legged robots. While much research has been published, both in the biomechanics and engineering fields regarding the analysis of these gaits, no single study has adequately characterized the dynamics of high-speed running as can be achieved in a realistic, yet simple, robotic system. The goal of this paper is to find the most energy-efficient, natural, and unconstrained gallop that can be achieved using a simulated quadrupedal robot with articulated legs, asymmetric mass distribution, and compliant legs. For comparison purposes, we also implement the bound and canter. The model used here is planar, although we will show that it captures much of the predominant dynamic characteristics observed in animals. While it is not our goal to prove anything about biological locomotion, the dynamic similarities between the gaits we produce and those found in animals does indicate a similar underlying dynamic mechanism. Thus, we will show that achieving natural, efficient high-speed locomotion is possible even with a fairly simple robotic system. To generate the high-speed gaits, we use an efficient evolutionary algorithm called set-based stochastic optimization. This algorithm finds open-loop control parameters to generate periodic trajectories for the body. Several alternative methods are tested to generate periodic trajectories for the legs. The combined solutions found by the evolutionary search and the periodic-leg methods, over a range of speeds up to 10.0 m/s, reveal "biological" characteristics that are emergent properties of the underlying gaits.
Dark matter stability and one-loop neutrino mass generation based on Peccei-Quinn symmetry
Energy Technology Data Exchange (ETDEWEB)
Suematsu, Daijiro [Kanazawa University, Institute for Theoretical Physics, Kanazawa (Japan)
2018-01-15
We propose a model which is a simple extension of the KSVZ invisible axion model with an inert doublet scalar. Peccei-Quinn symmetry forbids tree-level neutrino mass generation and its remnant Z{sub 2} symmetry guarantees dark matter stability. The neutrino masses are generated by one-loop effects as a result of the breaking of Peccei-Quinn symmetry through a nonrenormalizable interaction. Although the low energy effective model coincides with an original scotogenic model which contains right-handed neutrinos with large masses, it is free from the strong CP problem. (orig.)
Dark matter stability and one-loop neutrino mass generation based on Peccei-Quinn symmetry
Suematsu, Daijiro
2018-01-01
We propose a model which is a simple extension of the KSVZ invisible axion model with an inert doublet scalar. Peccei-Quinn symmetry forbids tree-level neutrino mass generation and its remnant Z_2 symmetry guarantees dark matter stability. The neutrino masses are generated by one-loop effects as a result of the breaking of Peccei-Quinn symmetry through a nonrenormalizable interaction. Although the low energy effective model coincides with an original scotogenic model which contains right-handed neutrinos with large masses, it is free from the strong CP problem.
Gas dynamic virtual nozzle for generation of microscopic droplet streams
Energy Technology Data Exchange (ETDEWEB)
DePonte, D P; Weierstall, U; Schmidt, K; Warner, J; Starodub, D; Spence, J C H; Doak, R B [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States)], E-mail: dandeponte@gmail.com
2008-10-07
As shown by Ganan-Calvo (1998 Phys. Rev. Lett. 80 285-8), a free liquid jet can be compressed in diameter through gas dynamic forces exerted by a coaxially co-flowing gas, obviating the need for a solid nozzle to form a microscopic liquid jet and thereby alleviating the clogging problems that plague conventional droplet sources of small diameter. We describe in this paper a novel form of droplet beam source based on this principle. The source is miniature, robust, dependable, easily fabricated, essentially immune to clogging and eminently suitable for delivery of microscopic liquid droplets, including hydrated biological samples, into vacuum for analysis using vacuum instrumentation. Monodisperse, single-file droplet streams are generated by triggering the device with a piezoelectric actuator.
Nonsingular electrovacuum solutions with dynamically generated cosmological constant
Energy Technology Data Exchange (ETDEWEB)
Guendelman, E.I., E-mail: guendel@bgumail.bgu.ac.il [Physics Department, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); Olmo, Gonzalo J., E-mail: gonzalo.olmo@csic.es [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia – CSIC, Universidad de Valencia, Burjassot 46100, Valencia (Spain); Rubiera-Garcia, D., E-mail: drubiera@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-900 João Pessoa, Paraíba (Brazil); Vasihoun, M., E-mail: maharyw@gmail.com [Physics Department, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)
2013-11-04
We consider static spherically symmetric configurations in a Palatini extension of General Relativity including R{sup 2} and Ricci-squared terms, which is known to replace the central singularity by a wormhole in the electrovacuum case. We modify the matter sector of the theory by adding to the usual Maxwell term a nonlinear electromagnetic extension which is known to implement a confinement mechanism in flat space. One feature of the resulting theory is that the nonlinear electric field leads to a dynamically generated cosmological constant. We show that with this matter source the solutions of the model are asymptotically de Sitter and possess a wormhole topology. We discuss in some detail the conditions that guarantee the absence of singularities and of traversable wormholes.
Yasaka, Koichiro; Akai, Hiroyuki; Abe, Osamu; Kiryu, Shigeru
2018-03-01
Purpose To investigate diagnostic performance by using a deep learning method with a convolutional neural network (CNN) for the differentiation of liver masses at dynamic contrast agent-enhanced computed tomography (CT). Materials and Methods This clinical retrospective study used CT image sets of liver masses over three phases (noncontrast-agent enhanced, arterial, and delayed). Masses were diagnosed according to five categories (category A, classic hepatocellular carcinomas [HCCs]; category B, malignant liver tumors other than classic and early HCCs; category C, indeterminate masses or mass-like lesions [including early HCCs and dysplastic nodules] and rare benign liver masses other than hemangiomas and cysts; category D, hemangiomas; and category E, cysts). Supervised training was performed by using 55 536 image sets obtained in 2013 (from 460 patients, 1068 sets were obtained and they were augmented by a factor of 52 [rotated, parallel-shifted, strongly enlarged, and noise-added images were generated from the original images]). The CNN was composed of six convolutional, three maximum pooling, and three fully connected layers. The CNN was tested with 100 liver mass image sets obtained in 2016 (74 men and 26 women; mean age, 66.4 years ± 10.6 [standard deviation]; mean mass size, 26.9 mm ± 25.9; 21, nine, 35, 20, and 15 liver masses for categories A, B, C, D, and E, respectively). Training and testing were performed five times. Accuracy for categorizing liver masses with CNN model and the area under receiver operating characteristic curve for differentiating categories A-B versus categories C-E were calculated. Results Median accuracy of differential diagnosis of liver masses for test data were 0.84. Median area under the receiver operating characteristic curve for differentiating categories A-B from C-E was 0.92. Conclusion Deep learning with CNN showed high diagnostic performance in differentiation of liver masses at dynamic CT. © RSNA, 2017 Online
Directory of Open Access Journals (Sweden)
Mohamed E. A. Farrag
2014-01-01
Full Text Available Incentives, such as the Feed-in-tariff are expected to lead to continuous increase in the deployment of Small Scale Embedded Generation (SSEG in the distribution network. Self-Excited Induction Generators (SEIG represent a significant segment of potential SSEG. The quality of SEIG output voltage magnitude and frequency is investigated in this paper to support the SEIG operation for different network operating conditions. The dynamic behaviour of the SEIG resulting from disconnection, reconnection from/to the grid and potential operation in islanding mode is studied in detail. The local load and reactive power supply are the key factors that determine the SEIG performance, as they have significant influence on the voltage and frequency change after disconnection from the grid. Hence, the aim of this work is to identify the optimum combination of the reactive power supply (essential for self excitation of the SEIG and the active load (essential for balancing power generation and demand. This is required in order to support the SEIG operation after disconnection from the grid, during islanding and reconnection to the grid. The results show that the generator voltage and speed (frequency can be controlled and maintained within the statuary limits. This will enable safe disconnection and reconnection of the SEIG from/to the grid and makes it easier to operate in islanding mode.
Solar atmosphere wave dynamics generated by solar global oscillating eigenmodes
Griffiths, M. K.; Fedun, V.; Erdélyi, R.; Zheng, R.
2018-01-01
The solar atmosphere exhibits a diverse range of wave phenomena, where one of the earliest discovered was the five-minute global acoustic oscillation, also referred to as the p-mode. The analysis of wave propagation in the solar atmosphere may be used as a diagnostic tool to estimate accurately the physical characteristics of the Sun's atmospheric layers. In this paper, we investigate the dynamics and upward propagation of waves which are generated by the solar global eigenmodes. We report on a series of hydrodynamic simulations of a realistically stratified model of the solar atmosphere representing its lower region from the photosphere to low corona. With the objective of modelling atmospheric perturbations, propagating from the photosphere into the chromosphere, transition region and low corona, generated by the photospheric global oscillations the simulations use photospheric drivers mimicking the solar p-modes. The drivers are spatially structured harmonics across the computational box parallel to the solar surface. The drivers perturb the atmosphere at 0.5 Mm above the bottom boundary of the model and are placed coincident with the location of the temperature minimum. A combination of the VALIIIC and McWhirter solar atmospheres are used as the background equilibrium model. We report how synthetic photospheric oscillations may manifest in a magnetic field free model of the quiet Sun. To carry out the simulations, we employed the magnetohydrodynamics code, SMAUG (Sheffield MHD Accelerated Using GPUs). Our results show that the amount of energy propagating into the solar atmosphere is consistent with a model of solar global oscillations described by Taroyan and Erdélyi (2008) using the Klein-Gordon equation. The computed results indicate a power law which is compared to observations reported by Ireland et al. (2015) using data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly.
A model of radiative neutrino masses. Mixing and a possible fourth generation
International Nuclear Information System (INIS)
Babu, K.S.; Ma, E.; Pantaleone, J.
1989-01-01
We consider the phenomenological consequences of a recently proposed model with four lepton generations such that the three known neutrinos have radiatively induced Majorana masses. Mixing among generations in the presence of a heavy fourth neutrino necessitates a reevaluation of the usual experimental tests of the standard model. One interesting possibility is to have a τ lifetime longer than predicted by the standard three-generation model. Another is to have neutrino masses and mixing angles in the range needed for a natural explanation of the solar-neutrino puzzle in terms of the Mikheyev-Smirnov-Wolfenstein effect. (orig.)
Dynamics of a Flywheel Energy Storage System Supporting a Wind Turbine Generator in a Microgrid
Nair S, Gayathri; Senroy, Nilanjan
2016-02-01
Integration of an induction machine based flywheel energy storage system with a wind energy conversion system is implemented in this paper. The nonlinear and linearized models of the flywheel are studied, compared and a reduced order model of the same simulated to analyze the influence of the flywheel inertia and control in system response during a wind power change. A quantification of the relation between the inertia of the flywheel and the controller gain is obtained which allows the system to be considered as a reduced order model that is more controllable in nature. A microgrid setup comprising of the flywheel energy storage system, a two mass model of a DFIG based wind turbine generator and a reduced order model of a diesel generator is utilized to analyse the microgrid dynamics accurately in the event of frequency variations arising due to wind power change. The response of the microgrid with and without the flywheel is studied.
Influence of light-quark masses in dynamical scale breaking
International Nuclear Information System (INIS)
Barcelos Neto, J.; Chanda, R.
1984-01-01
It is demonstrated that light quark masses may significantly contribute to the logarithmic scale breaking in deep inelastic electromagnetic lepton-nucleon scattering. This is mainly due to the combination of scale variables together with large 'current' masses for u and d quarks, recently reported in the literature. Upper limits for current masses of u and d quarks, using positivity properties of the forward electromagnetic structure function F 2 of the nucleon are also estimated. (Author) [pt
ECONOMIC ASPECTS OF MASS-MEDIA AND THE CHANGES GENERATED BY THE ECONOMIC CRISIS
Directory of Open Access Journals (Sweden)
TRAIAN ALEXANDRU NASTASE
2011-04-01
Full Text Available In this paper we intend to describe the economic implications of mass-media in correlation with the recent socio-economic changes generated by the economic crisis. We take into consideration the dual market on which mass-media evolves: the mass-media products market, and the advertising market, keeping in mind that the behavior of a mass-media institution on one market, can have direct implication on the other market. We analyze the relation between mass-media and the public (audience, the cost for creating mass-media products, the ways in which mass-media reduces costs and the ways of increasing their profits. As mass-media must always adapt to the social changes and to the public, we take our analysis further and we describe how the recent economic changes influenced the mass-media consumption trends and mass-media profits on all the main communication channels: TV, radio, outdoor, internet, newspapers/magazines. This analysis is performed at both a global and a local level, for Romania. In the end we predict how other key changes may affect the economic model approach of the mass-media institutions on short and middle terms.
International Nuclear Information System (INIS)
El-Nabulsi, Ahmad Rami
2009-01-01
Multidimensional fractional actionlike variational problem with time-dependent dynamical fractional exponents is constructed. Fractional Euler-Lagrange equations are derived and discussed in some details. The results obtained are used to explore some novel aspects of fractional quantum field theory where many interesting consequences are revealed, in particular the complexification of quantum field theory, in particular Dirac operators and the novel notion of 'mass without mass'.
Dynamic Diversity: Toward a Contextual Understanding of Critical Mass
Garces, Liliana M.; Jayakumar, Uma M.
2014-01-01
Through an analysis of relevant social science evidence, this article provides a deeper understanding of critical mass, a concept that has become central in litigation efforts related to affirmative action admissions policies that seek to further the educational benefits of diversity. We demonstrate that the concept of critical mass requires an…
Fluid dynamics and mass transfer in a gas centrifuge
International Nuclear Information System (INIS)
Conlisk, A.T.; Foster, M.R.; Walker, J.D.A.
1982-01-01
The fluid motion, temperature distribution and the mass-transfer problem of a binary gas mixture in a rapidly rotating centrifuge are investigated. Solutions for the velocity, temperature and mass-fraction fields within the centrifuge are obtained for mechanically or thermally driven centrifuges. For the mass-transfer problem, a detailed analysis of the fluid-mechanical boundary layers is required, and, in particular, mass fluxes within the boundary layers are obtained for a wide range of source-sink geometries. Solutions to the mass-transfer problem are obtained for moderately and strongly forced flows in the container; the dependence of the separation (or enrichment) factor on centrifuge configuration, rotational speed and fraction of the volumetric flow rate extracted at the product port (the cut) are predicted. (author)
Forward and backward dynamics in implicitly defined overlapping generations models
Gardini, L.; Hommes, C.; Tramontana, F.; de Vilder, R.
2009-01-01
In dynamic economic models derived from optimization principles, the forward equilibrium dynamics may not be uniquely defined, while the backward dynamics is well defined. We derive properties of the global forward equilibrium paths based on properties of the backward dynamics. We propose the
Right-handed neutrinos at CERN LHC and the mechanism of neutrino mass generation
International Nuclear Information System (INIS)
Kersten, Joern; Smirnov, Alexei Yu.
2007-01-01
We consider the possibility to detect right-handed neutrinos, which are mostly singlets of the standard model gauge group, at future accelerators. Substantial mixing of these neutrinos with the active neutrinos requires a cancellation of different contributions to the light neutrino mass matrix at the level of 10 -8 . We discuss possible symmetries behind this cancellation and argue that for three right-handed neutrinos they always lead to conservation of total lepton number. Light neutrino masses can be generated by small perturbations violating these symmetries. In the most general case, LHC physics and the mechanism of neutrino mass generation are essentially decoupled; with additional assumptions, correlations can appear between collider observables and features of the neutrino mass matrix
International Nuclear Information System (INIS)
Lasorne, Benjamin; Sicilia, Fabrizio; Bearpark, Michael J.; Robb, Michael A.; Worth, Graham A.; Blancafort, Lluis
2008-01-01
A new practical method to generate a subspace of active coordinates for quantum dynamics calculations is presented. These reduced coordinates are obtained as the normal modes of an analytical quadratic representation of the energy difference between excited and ground states within the complete active space self-consistent field method. At the Franck-Condon point, the largest negative eigenvalues of this Hessian correspond to the photoactive modes: those that reduce the energy difference and lead to the conical intersection; eigenvalues close to 0 correspond to bath modes, while modes with large positive eigenvalues are photoinactive vibrations, which increase the energy difference. The efficacy of quantum dynamics run in the subspace of the photoactive modes is illustrated with the photochemistry of benzene, where theoretical simulations are designed to assist optimal control experiments
Dirac Mass Dynamics in Multidimensional Nonlocal Parabolic Equations
Lorz, Alexander; Mirrahimi, Sepideh; Perthame, Benoî t
2011-01-01
simulations show that the trajectories can exhibit unexpected dynamics well explained by this equation. Our motivation comes from population adaptive evolution a branch of mathematical ecology which models Darwinian evolution. © Taylor & Francis Group, LLC.
Molecular dynamics in drug design: new generations of compstatin analogs.
Tamamis, Phanourios; López de Victoria, Aliana; Gorham, Ronald D; Bellows-Peterson, Meghan L; Pierou, Panayiota; Floudas, Christodoulos A; Morikis, Dimitrios; Archontis, Georgios
2012-05-01
We report the computational and rational design of new generations of potential peptide-based inhibitors of the complement protein C3 from the compstatin family. The binding efficacy of the peptides is tested by extensive molecular dynamics-based structural and physicochemical analysis, using 32 atomic detail trajectories in explicit water for 22 peptides bound to human, rat or mouse target protein C3, with a total of 257 ns. The criteria for the new design are: (i) optimization for C3 affinity and for the balance between hydrophobicity and polarity to improve solubility compared to known compstatin analogs; and (ii) development of dual specificity, human-rat/mouse C3 inhibitors, which could be used in animal disease models. Three of the new analogs are analyzed in more detail as they possess strong and novel binding characteristics and are promising candidates for further optimization. This work paves the way for the development of an improved therapeutic for age-related macular degeneration, and other complement system-mediated diseases, compared to known compstatin variants. © 2012 John Wiley & Sons A/S.
Dynamic airspace configuration algorithms for next generation air transportation system
Wei, Jian
The National Airspace System (NAS) is under great pressure to safely and efficiently handle the record-high air traffic volume nowadays, and will face even greater challenge to keep pace with the steady increase of future air travel demand, since the air travel demand is projected to increase to two to three times the current level by 2025. The inefficiency of traffic flow management initiatives causes severe airspace congestion and frequent flight delays, which cost billions of economic losses every year. To address the increasingly severe airspace congestion and delays, the Next Generation Air Transportation System (NextGen) is proposed to transform the current static and rigid radar based system to a dynamic and flexible satellite based system. New operational concepts such as Dynamic Airspace Configuration (DAC) have been under development to allow more flexibility required to mitigate the demand-capacity imbalances in order to increase the throughput of the entire NAS. In this dissertation, we address the DAC problem in the en route and terminal airspace under the framework of NextGen. We develop a series of algorithms to facilitate the implementation of innovative concepts relevant with DAC in both the en route and terminal airspace. We also develop a performance evaluation framework for comprehensive benefit analyses on different aspects of future sector design algorithms. First, we complete a graph based sectorization algorithm for DAC in the en route airspace, which models the underlying air route network with a weighted graph, converts the sectorization problem into the graph partition problem, partitions the weighted graph with an iterative spectral bipartition method, and constructs the sectors from the partitioned graph. The algorithm uses a graph model to accurately capture the complex traffic patterns of the real flights, and generates sectors with high efficiency while evenly distributing the workload among the generated sectors. We further improve
Study of a possible S=+1 dynamically generated baryonic resonance
International Nuclear Information System (INIS)
Sarkar, S.; Oset, E.; Vaca, M.J.V.
2005-01-01
Starting from the lowest-order chiral Lagrangian for the interaction of the baryon decuplet with the octet of pseudoscalar mesons we find an attractive interaction in the ΔK channel with L=0 and I=1, while the interaction is repulsive for I=2. The attractive interaction leads to a pole in the second Riemann sheet of the complex plane and manifests itself in a large strength of the K scattering amplitude close to the ΔK threshold, which is not the case for I=2. However, we also make a study of uncertainties in the model and conclude that the existence of this pole depends sensitively upon the input used and can disappear within reasonable variations of the input parameters. We take advantage to study the stability of the other poles obtained for the 3/2 - dynamically generated resonances of the model and conclude that they are stable and not contingent to reasonable changes in the input of the theory
Trap Generation Dynamics in Photo-Oxidised DEH Doped Polymers
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David M. Goldie
2015-07-01
Full Text Available A series of polyester films doped with a hole transport molecule, p-diethylaminobenzaldehyde-1,1'-diphenylhydrazone (DEH, have been systematically exposed to ultraviolet radiation with a peak wavelength of about 375 nm. The electronic performance of the films, evaluated using time-of-flight and space-charge current injection methods, is observed to continuously degrade with increasing ultraviolet exposure. The degradation is attributed to photo cyclic oxidation of DEH that results in the creation of indazole (IND molecules which function as bulk hole traps. A proposed model for the generation dynamics of the IND traps is capable of describing both the reduction in current injection and the associated time-of-flight hole mobility provided around 1% of the DEH population produce highly reactive photo-excited states which are completely converted to indazole during the UV exposure period. The rapid reaction of these states is incompatible with bulk oxygen diffusion-reaction kinetics within the films and is attributed to the creation of excited states within the reaction radius of soluble oxygen. It is suggested that encapsulation strategies to preserve the electronic integrity of the films should accordingly focus upon limiting the critical supply of oxygen for photo cyclic reaction.
Enabling full field physics based OPC via dynamic model generation
Lam, Michael; Clifford, Chris; Raghunathan, Ananthan; Fenger, Germain; Adam, Kostas
2017-03-01
As EUV lithography marches closer to reality for high volume production, its peculiar modeling challenges related to both inter- and intra- field effects has necessitated building OPC infrastructure that operates with field position dependency. Previous state of the art approaches to modeling field dependency used piecewise constant models where static input models are assigned to specific x/y-positions within the field. OPC and simulation could assign the proper static model based on simulation-level placement. However, in the realm of 7nm and 5nm feature sizes, small discontinuities in OPC from piecewise constant model changes can cause unacceptable levels of EPE errors. The introduction of Dynamic Model Generation (DMG) can be shown to effectively avoid these dislocations by providing unique mask and optical models per simulation region, allowing a near continuum of models through field. DMG allows unique models for EMF, apodization, aberrations, etc to vary through the entire field and provides a capability to precisely and accurately model systematic field signatures.
Variational study of mass generation and deconfinement in Yang-Mills theory
Comitini, Giorgio; Siringo, Fabio
2018-03-01
A very simple variational approach to pure SU (N ) Yang-Mills theory is proposed, based on the Gaussian effective potential in a linear covariant gauge. The method provides an analytical variational argument for mass generation. The method can be improved order by order by a perturbative massive expansion around the optimal trial vacuum. At finite temperature, a weak first-order transition is found (at Tc≈250 MeV for N =3 ) where the mass scale drops discontinuously. Above the transition the optimal mass increases linearly as expected for deconfined bosons. The equation of state is found in good agreement with the lattice data.
Measurement of collective dynamical mass of Dirac fermions in graphene.
Yoon, Hosang; Forsythe, Carlos; Wang, Lei; Tombros, Nikolaos; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Kim, Philip; Ham, Donhee
2014-08-01
Individual electrons in graphene behave as massless quasiparticles. Unexpectedly, it is inferred from plasmonic investigations that electrons in graphene must exhibit a non-zero mass when collectively excited. The inertial acceleration of the electron collective mass is essential to explain the behaviour of plasmons in this material, and may be directly measured by accelerating it with a time-varying voltage and quantifying the phase delay of the resulting current. This voltage-current phase relation would manifest as a kinetic inductance, representing the reluctance of the collective mass to accelerate. However, at optical (infrared) frequencies, phase measurements of current are generally difficult, and, at microwave frequencies, the inertial phase delay has been buried under electron scattering. Therefore, to date, the collective mass in graphene has defied unequivocal measurement. Here, we directly and precisely measure the kinetic inductance, and therefore the collective mass, by combining device engineering that reduces electron scattering and sensitive microwave phase measurements. Specifically, the encapsulation of graphene between hexagonal boron nitride layers, one-dimensional edge contacts and a proximate top gate configured as microwave ground together enable the inertial phase delay to be resolved from the electron scattering. Beside its fundamental importance, the kinetic inductance is found to be orders of magnitude larger than the magnetic inductance, which may be utilized to miniaturize radiofrequency integrated circuits. Moreover, its bias dependency heralds a solid-state voltage-controlled inductor to complement the prevalent voltage-controlled capacitor.
Szurgacz, Dawid; Brodny, Jaroław
2018-01-01
A powered roof support is a machine responsible for protection of an underground excavation against deformation generated by rock mass. In the case of dynamic impact of rock mass, the proper level of protection is hard to achieve. Therefore, the units of the roof support and its components are subject to detailed tests aimed at acquiring greater reliability, efficiency and efficacy. In the course of such test, however, it is not always possible to foresee values of load that may occur in actual conditions. The article presents a case of a dynamic load impacting the powered roof support during a high-energy tremor in an underground hard coal mine. The authors discuss the method for selecting powered roof support units proper for specific forecasted load conditions. The method takes into account the construction of the support and mining and geological conditions of an excavation. Moreover, the paper includes tests carried out on hydraulic legs and yield valves which were responsible for additional yielding of the support. Real loads impacting the support unit during tremors are analysed. The results indicated that the real registered values of the load were significantly greater than the forecasted values. The analysis results of roof support operation during dynamic impact generated by the rock mass (real life conditions) prompted the authors to develop a set of recommendations for manufacturers and users of powered roof supports. These include, inter alia, the need for innovative solutions for testing hydraulic section systems.
Dynamics of Mass Transfer in Wide Symbiotic Systems
de Val-Borro, Miguel; Karovska, M.; Sasselov, D.
2010-01-01
We investigate the formation of accretion disks around the secondary in detached systems consisting of an Asymptotic Giant Branch (AGB) star and a compact accreting companion as a function of mass loss rate and orbital parameters. In particular, we study winds from late-type stars that are gravitationally focused by a companion in a wide binary system using hydrodynamical simulations. For a typical slow and massive wind from an evolved star there is a stream flow between the stars with accretion rates of a few percent of the mass loss from the primary. Mass transfer through a focused wind is an important mechanism for a broad range of interacting binary systems and can explain the formation of Barium stars and other chemically peculiar stars.
Web-based Toolkit for Dynamic Generation of Data Processors
Patel, J.; Dascalu, S.; Harris, F. C.; Benedict, K. K.; Gollberg, G.; Sheneman, L.
2011-12-01
All computation-intensive scientific research uses structured datasets, including hydrology and all other types of climate-related research. When it comes to testing their hypotheses, researchers might use the same dataset differently, and modify, transform, or convert it to meet their research needs. Currently, many researchers spend a good amount of time performing data processing and building tools to speed up this process. They might routinely repeat the same process activities for new research projects, spending precious time that otherwise could be dedicated to analyzing and interpreting the data. Numerous tools are available to run tests on prepared datasets and many of them work with datasets in different formats. However, there is still a significant need for applications that can comprehensively handle data transformation and conversion activities and help prepare the various processed datasets required by the researchers. We propose a web-based application (a software toolkit) that dynamically generates data processors capable of performing data conversions, transformations, and customizations based on user-defined mappings and selections. As a first step, the proposed solution allows the users to define various data structures and, in the next step, can select various file formats and data conversions for their datasets of interest. In a simple scenario, the core of the proposed web-based toolkit allows the users to define direct mappings between input and output data structures. The toolkit will also support defining complex mappings involving the use of pre-defined sets of mathematical, statistical, date/time, and text manipulation functions. Furthermore, the users will be allowed to define logical cases for input data filtering and sampling. At the end of the process, the toolkit is designed to generate reusable source code and executable binary files for download and use by the scientists. The application is also designed to store all data
Strange and charm baryon masses with two flavors of dynamical twisted mass fermions
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, C. [Univ. of Cyprus, Nicosia (Cyprus). Dept. of Physics; Cyprus Institute, Nicosia (Cyprus). Computation-Based Science and Technology Research Center; Carbonell, J. [CEA-Saclay, Gif-sur-Yvette (France). IRFU/Service de Physique Nucleaire; Christaras, D.; Gravina, M. [Univ. of Cyprus, Nicosia (Cyprus). Dept. of Physics; Drach, V. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Papinutto, M. [UFJ/CNRS/IN2P3, Grenoble (France). Laboratoire de Physique Subatomique et Cosmologie; Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Universidad Autonoma de Madrid UAM/CSIC (Spain). Inst. de Fisica Teorica
2012-10-15
The masses of the low-lying strange and charm baryons are evaluated using two degenerate flavors of twisted mass sea quarks for pion masses in the range of about 260 MeV to 450 MeV. The strange and charm valence quark masses are tuned to reproduce the mass of the kaon and D-meson at the physical point. The tree-level Symanzik improved gauge action is employed. We use three values of the lattice spacing, corresponding to {beta}=3.9, {beta}=4.05 and {beta}=4.2 with r{sub 0}/a=5.22(2), r{sub 0}/a=6.61(3) and r{sub 0}/a=8.31(5) respectively. We examine the dependence of the strange and charm baryons on the lattice spacing and strange and charm quark masses. The pion mass dependence is studied and physical results are obtained using heavy baryon chiral perturbation theory to extrapolate to the physical point.
International Nuclear Information System (INIS)
Goncharov, Yu.P.
1982-01-01
In a spacetime having a nontrivial topology QCD may have properties which are absent for QCD in Minkowski spacetime. Two new possibilities for QCD are discussed by the example of spacetime with topology R x (S 1 ) 3 and flat metric: the topological origin of flavours and topological gluon mass generation. (orig.)
Social Relations That Generate and Sustain Solidarity after a Mass Tragedy
Hawdon, James; Ryan, John
2011-01-01
Numerous researchers discuss the solidarity-producing effects of crime, natural disasters and mass tragedies; however, there is much we do not understand about the processes involved in the phenomena. We specify the social relationships that "generate" and "sustain" solidarity by building on Hunter's descriptions of the…
Dynamic Secondary Ion Mass Spectrometry | Materials Science | NREL
Ion Mass Spectrometry (SIMS) uses a continuous, focused beam of primary ions to remove material from the surface of a sample by sputtering. The fraction of sputtered material that is ionized is extracted Identifies all elements or isotopes present in a material, from hydrogen to uranium. Different primary-ion
Dynamic Analysis of Load Operations of Two-Stage SOFC Stacks Power Generation System
Directory of Open Access Journals (Sweden)
Paulina Pianko-Oprych
2017-12-01
Full Text Available The main purpose of this paper was to develop a complete dynamic model of a power generation system based on two serially connected solid oxide fuel cell stacks. The uniqueness of this study lies in a different number of fuel cells in the stacks. The model consists of the electrochemical model, mass and energy balance equations implemented in MATLAB Simulink environment. Particular attention has been paid to the analysis of the transient response of the reformers, fuel cells and the burner. The dynamic behavior of the system during transient conditions was investigated by load step changing. The model evaluates electrical and thermal responses of the system at variable drawn current. It was found that a decrease of 40% in the 1st stage and 2nd solid oxide fuel cell (SOFC stacks drawn current caused both stacks temperature to drop by 2%. An increase of the cell voltage for the 1st and 2nd SOFC stacks led to very fast steam reformer response combined with a slight decrease in reformer temperature, while a considerable burner temperature increase of 70 K can be observed. Predictions of the model provide the basic insight into the operation of the power generation-based SOFC system during various transients and support its further design modifications.
Dynamic plant uptake modelling and mass flux estimation
DEFF Research Database (Denmark)
Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan
2011-01-01
in environmental systems at different scales. Feedback mechanisms between plants and hydrological systems can play an important role. However, they have received little attention to date. Here, a new model concept for dynamic plant uptake models applying analytical matrix solutions is presented, which can...
Optimal Passive Dynamics for Physical Interaction: Catching a Mass
Directory of Open Access Journals (Sweden)
Kevin Kemper
2013-05-01
Full Text Available For manipulation tasks in uncertain environments, intentionally designed series impedance in mechanical systems can provide significant benefits that cannot be achieved in software. Traditionally, the design of actuated systems revolves around sizing torques, speeds, and control strategies without considering the system’s passive dynamics. However, the passive dynamics of the mechanical system, including inertia, stiffness, and damping along with other parameters such as torque and stroke limits often impose performance limitations that cannot be overcome with software control. In this paper, we develop relationships between an actuator’s passive dynamics and the resulting performance for the purpose of better understanding how to tune the passive dynamics for catching an unexpected object. We use a mathematically optimal controller subject to force limitations to stop the incoming object without breaking contact and bouncing. The use of an optimal controller is important so that our results directly reflect the physical system’s performance. We analytically calculate the maximum velocity that can be caught by a realistic actuator with limitations such as force and stroke limits. The results show that in order to maximize the velocity of an object that can be caught without exceeding the actuator’s torque and stroke limits, a soft spring along with a strong damper will be desired.
Colangelo, Antonio C.
2010-05-01
The central purpose of this work is to perform a reverse procedure in the mass movement conventional parameterization approach. The idea is to generate a number of synthetic mass movements by means of the "slope stability simulator" (Colangelo, 2007), and compeer their morphological and physical properties with "real" conditions of effective mass movements. This device is an integrated part of "relief unity emulator" (rue), that permits generate synthetic mass movements in a synthetic slope environment. The "rue" was build upon fundamental geomorphological concepts. These devices operate with an integrated set of mechanical, geomorphic and hydrological models. The "slope stability simulator" device (sss) permits to perform a detailed slope stability analysis in a theoretical three dimensional space, by means of evaluation the spatial behavior of critical depths, gradients and saturation levels in the "potential rupture surfaces" inferred along a set of slope profiles, that compounds a synthetic slope unity. It's a meta-stable 4-dimensional object generated by means of "rue", that represents a sequence evolution of a generator profile applied here, was adapted the infinite slope model for slope. Any slope profiles were sliced by means of finite element solution like in Bishop method. For the synthetic slope systems generated, we assume that the potential rupture surface occurs at soil-regolith or soil-rock boundary in slope material. Sixteen variables were included in the "rue-sss" device that operates in an integrated manner. For each cell, the factor of safety was calculated considering the value of shear strength (cohesion and friction) of material, soil-regolith boundary depth, soil moisture level content, potential rupture surface gradient, slope surface gradient, top of subsurface flow gradient, apparent soil bulk density and vegetation surcharge. The slope soil was considered as cohesive material. The 16 variables incorporated in the models were analyzed for
Strain in shock-loaded skeletal muscle and the time scale of muscular wobbling mass dynamics.
Christensen, Kasper B; Günther, Michael; Schmitt, Syn; Siebert, Tobias
2017-10-16
In terrestrial locomotion, muscles undergo damped oscillations in response to limb impacts with the ground. Muscles are also actuators that generate mechanical power to allow locomotion. The corresponding elementary contractile process is the work stroke of an actin-myosin cross-bridge, which may be forcibly detached by superposed oscillations. By experimentally emulating rat leg impacts, we found that full activity and non-fatigue must meet to possibly prevent forcible cross-bridge detachment. Because submaximal muscle force represents the ordinary locomotor condition, our results show that forcible, eccentric cross-bridge detachment is a common, physiological process even during isometric muscle contractions. We also calculated the stiffnesses of the whole muscle-tendon complex and the fibre material separately, as well as Young's modulus of the latter: 1.8 MPa and 0.75 MPa for fresh, fully active and passive fibres, respectively. Our inferred Young's modulus of the tendon-aponeurosis complex suggests that stiffness in series to the fibre material is determined by the elastic properties of the aponeurosis region, rather than the tendon material. Knowing these stiffnesses and the muscle mass, the complex' eigenfrequency for responses to impacts can be quantified, as well as the size-dependency of this time scale of muscular wobbling mass dynamics.
2D dynamics of the radiative core of low mass stars
Directory of Open Access Journals (Sweden)
Hypolite Delphine
2017-01-01
Full Text Available Understanding the internal rotation of low mass stars all along their evolution is of primary interest when studying their rotational dynamics, internal mixing and magnetic field generation. In this context, helio- and asteroseismology probe angular velocity gradients deep within solar type stars at different evolutionary stages. Still the rotation close to the center of such stars on the main sequence is hardly detectable and the dynamical interaction of the radiative core with the surface convective envelope is not well understood. For instance, the influence of the differential rotation profile sustained by convection and applied as a boundary condition to the radiation zone is very important in the formation of tachoclines. In this work, we study a 2D hydrodynamical model of a radiative core when an imposed, solar or anti-solar, differential rotation is applied at the upper boundary. This model uses the Boussinesq approximation and we find that the shear induces a cylindrical differential rotation associated with a unique cell of meridional circulation in each hemisphere (counterclockwise when the shear is solar-like and clockwise when it is anti-solar. The results are discussed in the framework of seismic observables (internal rotation rate, core-to-surface rotation ratio while perspectives to improve our modeling by including magnetic field or transport by internal gravity waves will be discussed.
Comparison of Various Dynamic Balancing Principles Regarding Additional Mass and Additional Inertia
van der Wijk, V.; Demeulenaere, Bram; Herder, Justus Laurens
2009-01-01
The major disadvantage of existing dynamic balancing principles is that a considerable amount of mass and inertia is added to the system. The objectives of this article are to summarize, to compare, and to evaluate existing complete balancing principles regarding the addition of mass and the
McDermid, Richard M.; Cappellari, Michele; Alatalo, Katherine; Bayet, Estelle; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Crocker, Alison F.; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie; Young, Lisa M.
We report on empirical trends between the dynamically determined stellar initial mass function (IMF) and stellar population properties for a complete, volume-limited sample of 260 early-type galaxies from the ATLAS3D project. We study trends between our dynamically derived IMF normalization αdyn ≡
Dynamic optical bistability in resonantly enhanced Raman generation
International Nuclear Information System (INIS)
Novikova, I.; Phillips, D.F.; Zibrov, A.S.; Andre, A.; Walsworth, R.L.
2004-01-01
We report observations of novel dynamic behavior in resonantly enhanced stimulated Raman scattering in Rb vapor. In particular, we demonstrate a dynamic hysteresis of the Raman scattered optical field in response to changes of the drive laser field intensity and/or frequency. This effect may be described as a dynamic form of optical bistability resulting from the formation and decay of atomic coherence. We have applied this phenomenon to the realization of an all-optical switch
Pulsed neutron generator for mass flow measurement using the pulsed neutron activation technique
International Nuclear Information System (INIS)
Rochau, G.E.; Hornsby, D.R.; Mareda, J.F.; Riggan, W.C.
1980-01-01
A high-output, transportable neutron generator has been developed to measure mass flow velocities in reactor safety tests using the Pulsed Neutron Activation (PNA) Technique. The PNA generator produces >10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. The Millisecond Pulse (MSP) Neutron Tube, developed for this application, has an expected operational life of 1000 pulses, and it limits the generator pulse repetition rate to 12 pulses/minute. A semiconductor neutron detector is included in the generator package to monitor the neutron output. The control unit, which can be operated manually or remotely, also contains a digital display with a BCD output for the neutron monitor information. The digital logic of the unit controls the safety interlocks and rejects transient signals which could accidently fire the generator
The Dynamics of the Aspirations and Demands of Different Generations of Russia's Young People
Khotkina, Z. A.
2013-01-01
Survey data comparing the life aspirations of three generations of Russians show an increase from the level of the Soviet generation of young people to the perestroika generation, followed by a decline in the generation of young people who were born and grew up in today's "market" Russia. One chief cause of the downward dynamic of their…
Grimm, Ronald L; Beauchamp, J L
2010-01-28
We investigate the Rayleigh discharge and evaporation dynamics of highly charged two-component droplets consisting principally of methanol with 2-methoxyethanol, tert-butanol, or m-nitrobenzyl alcohol. A phase Doppler anemometer (PDA) characterizes droplets generated by electrospray ionization (ESI) according to size, velocity, and charge as they move through a uniform electric field within an ion mobility spectrometer (IMS). Repeated field reversals result in droplet "ping-pong" through the PDA. This generates individual droplet histories of solvent evaporation behavior and the dynamics of charge loss to progeny droplets during Rayleigh discharge events. On average, methanol droplets discharge at 127% their Rayleigh limit of charge, q(R), and release 25% of the net charge. Charge loss from methanol/2-methoxyethanol droplets behaves similarly to pure 2-methoxyethanol droplets which release approximately 28% of their net charge. Binary methanol droplets containing up to 50% tert-butanol discharge at a lower percent q(R) than pure methanol and release a greater fraction of their net charge. Mixed 99% methanol/1% m-nitrobenzyl alcohol droplets possess discharge characteristics similar to those of methanol. However, droplets of methanol containing 2% m-nitrobenzyl evaporate down to a fixed size and charge that remains constant with no observable discharges. Quasi-steady-state evaporation models accurately describe observed evaporation phenomena in which methanol/tert-butanol droplets evaporate at a rate similar to that of pure methanol and methanol/2-methoxyethanol droplets evaporate at a rate similar to that of 2-methoxyethanol. We compare these results to previous Rayleigh discharge experiments and discuss the implications for binary solvents in electrospray mass spectrometry (ESI-MS) and field-induced droplet ionization mass spectrometry (FIDI-MS).
Orbit and Dynamical Mass of the Late-T Dwarf GL 758 B
Bowler, Brendan P.; Dupuy, Trent J.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Fulton, Benjamin J.; Petigura, Erik A.; Howard, Andrew W.; Hirsch, Lea; Kratter, Kaitlin M.; Crepp, Justin R.; Biller, Beth A.; Johnson, Marshall C.; Wittenmyer, Robert A.
2018-04-01
Gl 758 B is a late-T dwarf orbiting a metal-rich Sun-like star at a projected separation of ρ ≈ 1.″6 (25 au). We present four epochs of astrometry of this system with NIRC2 at Keck Observatory spanning 2010 to 2017 together with 630 radial velocities (RVs) of the host star acquired over the past two decades from McDonald Observatory, Keck Observatory, and the Automated Planet Finder at Lick Observatory. The RVs reveal that Gl 758 is accelerating with an evolving rate that varies between 2 and 5 m s‑1 yr‑1, consistent with the expected influence of the imaged companion Gl 758 B. A joint fit of the RVs and astrometry yields a dynamical mass of {42}-7+19 M Jup for the companion with a robust lower limit of 30.5 M Jup at the 4-σ level. Gl 758 B is on an eccentric orbit (e = 0.26–0.67 at 95% confidence) with a semimajor axis of a = {21.1}-1.3+2.7 au and an orbital period of P = {96}-9+21 yr, which takes it within ≈9 au from its host star at periastron passage. Substellar evolutionary models generally underpredict the mass of Gl 758 B for nominal ages of 1–6 Gyr that have previously been adopted for the host star. This discrepancy can be reconciled if the system is older—which is consistent with activity indicators and recent isochrone fitting of the host star—or alternatively if the models are systematically overluminous by ≈0.1–0.2 dex. Gl 758 B is currently the lowest-mass directly imaged companion inducing a measured acceleration on its host star. In the future, bridging RVs and high-contrast imaging with the next generation of extremely large telescopes and space-based facilities will open the door to the first dynamical mass measurements of imaged exoplanets. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible
International Nuclear Information System (INIS)
Kats, F.M.; Ostrovskij, L.A.; Ehskin, N.B.
1985-01-01
An experimental bench is described as well as the results of dynamic performance investigation of mass- and heat transfer of the once-through type steam generator for the NPP with weak superheat. Coolant for the primary and secondary circuit is water. Under investigation conditions the possibility of changin.o primary and secondary circuit temperatures has been supphed as well as the primary circuit flow rate and the secondary circuit pressure changes. Transients for differen.t operating conditions are considered. The possibility for construction of the steam generator automatic control system is based
International Nuclear Information System (INIS)
Chuvatin, Alexander S.; Vesey, Roger Alan; Waisman, Eduardo Mario; Esaulov, Andrey A.; Ampleford, David J.; Kantsyrev, Victor Leonidovich; Cuneo, Michael Edward; Rudakov, Leonid I.; Coverdale, Christine Anne; Jones, Brent Manley; Safronova, Alla S.; Jones, Michael C.
2008-01-01
Planar wire arrays are studied at 3-6 MA on the Saturn pulsed power generator as potential drivers of compact hohlraums for inertial confinement fusion studies. Comparison with zero-dimensional modeling suggests that there is significant trailing mass. The modeled energy coupled from the generator cannot generally explain the energy in the main x-ray pulse. Preliminary comparison at 1-6 MA indicates sub-quadratic scaling of x-ray power in a manner similar to compact cylindrical wire arrays. Time-resolved pinhole images are used to study the implosion dynamics
Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M
2012-01-01
The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol
Molecular theory of mass transfer kinetics and dynamics at gas-water interface
International Nuclear Information System (INIS)
Morita, Akihiro; Garrett, Bruce C
2008-01-01
The mass transfer mechanism across gas-water interface is studied with molecular dynamics (MD) simulation. The MD results provide a robust and qualitatively consistent picture to previous studies about microscopic aspects of mass transfer, including interface structure, free energy profiles for the uptake, scattering dynamics and energy relaxation of impinging molecules. These MD results are quantitatively compared with experimental uptake measurements, and we find that the apparent inconsistency between MD and experiment could be partly resolved by precise decomposition of the observed kinetics into elemental steps. Remaining issues and future perspectives toward constructing a comprehensive multi-scale description of interfacial mass transfer are summarized.
Dynamic Simulation over Long Time Periods with 100% Solar Generation.
Energy Technology Data Exchange (ETDEWEB)
Concepcion, Ricky James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-12-01
This project aimed to identify the path forward for dynamic simulation tools to accommodate these needs by characterizing the properties of power systems (with high PV penetration), analyzing how these properties affect dynamic simulation software, and offering solutions for potential problems.
Dynamic analysis of CO₂ labeling and cell respiration using membrane-inlet mass spectrometry.
Yang, Tae Hoon
2014-01-01
Here, we introduce a mass spectrometry-based analytical method and relevant technical details for dynamic cell respiration and CO2 labeling analysis. Such measurements can be utilized as additional information and constraints for model-based (13)C metabolic flux analysis. Dissolved dynamics of oxygen consumption and CO2 mass isotopomer evolution from (13)C-labeled tracer substrates through different cellular processes can be precisely measured on-line using a miniaturized reactor system equipped with a membrane-inlet mass spectrometer. The corresponding specific rates of physiologically relevant gases and CO2 mass isotopomers can be quantified within a short-term range based on the liquid-phase dynamics of dissolved fermentation gases.
Dynamic retardation corrections to the mass spectrum of heavy quarkonia
International Nuclear Information System (INIS)
Kopalejshvili, T.; Rusetskij, A.
1996-01-01
In the framework of the Logunov-Tavkhelidze quasipotential approach the first-order retardation corrections to the heavy quarkonia mass spectrum are calculated with the use of the stationary wave boundary condition in the covariant kernel of the Bethe-Salpeter equation. As has been expected, these corrections turn out to be small for all low-lying heavy meson states and vanish in the heavy quark limit (m Q →∞). The comparison of the suggested approach to the calculation of retardation corrections with others, known in literature, is carried out. 22 refs., 1 tab
Dynamic mass exchange in doubly degenerate binaries. I - 0.9 and 1.2 solar mass stars
International Nuclear Information System (INIS)
Benz, W.; Cameron, A.G.W.; Press, W.H.; Bowers, R.L.
1990-01-01
The dynamic mass exchange process in doubly degenerate binaries was investigated using a three-dimensional numerical simulation of the evolution of a doubly degenerate binary system in which the primary is a 1.2-solar-mass white dwarf and the Roche lobe filling secondary is a 0.9-solar-mass dwarf. The results show that, in a little more than two orbital periods, the secondary is completely destroyed and transformed into a thick disk orbiting about the primary. Since only a very small fraction of the mass (0.0063 solar mass) escapes the system, the evolution of the binary results in the formation of a massive object. This object is composed of three parts, the initial white dwarf primary, a very hot pressure-supported spherical envelope, and a rotationally supported outer disk. The evolution of the system can be understood in terms of a simple analytical model where it is shown that the angular momentum carried by the mass during the transfer and stored in the disk determines the evolution of the system. 34 refs
Energy Technology Data Exchange (ETDEWEB)
Chaudhuri, A. [B.K.C. College, Department of Physics, Kolkata (India); Chaudhuri, S. [University of Burdwan, Department of Physics, Burdwan (India)
2017-11-15
In the paper, magnetostatic solutions of the Einstein-Maxwell field equations are generated from the gravitational two-soliton solutions of a stationary mass. Using the soliton technique of Belinskii and Zakharov (Sov Phys JETP 48:985, 1978, Sov Phys JETP 50:1, 1979), we construct diagonal two-soliton solutions of Einstein's gravitational field equations for an axially symmetric stationary space-time and investigate some properties of the generated stationary gravitational metric. Magnetostatic solutions corresponding to the generated stationary gravitational solutions are then constructed using the transformation technique of Das and Chaudhuri (Pramana J Phys 40:277, 1993). The mass and the dipole moment of the source are evaluated. In our analysis we make use of a second transformation (Chaudhuri in Pramana J Phys 58:449, 2002), probably for the first time in the literature, to generate magnetostatic solutions from the stationary gravitational two-soliton solutions which give us simple and straightforward expressions for the mass and the magnetic dipole moment. (orig.)
Dynamics of galaxies and the 'missing mass' problem
Energy Technology Data Exchange (ETDEWEB)
Gunn, J E [Hale Observatories, Pasadena, CA (USA)
1980-03-06
The observational situation concerning the existence of dark matter in the outer parts of galaxies is reviewed. Observation now leaves little doubt of its presence, and both observation and simple theory suggest that the dark matter is probably bound to galaxies, and furthermore is present around both spirals and ellipticals. New evidence concerning the rotation curve of the Galaxy shows that the distribution of the halo stuff in our own system is roughly spherical, as seems natural from existing dynamical data on the nature of the halo material.
Ground Reaction Forces Generated During Rhythmical Squats as a Dynamic Loads of the Structure
Pantak, Marek
2017-10-01
Dynamic forces generated by moving persons can lead to excessive vibration of the long span, slender and lightweight structure such as floors, stairs, stadium stands and footbridges. These dynamic forces are generated during walking, running, jumping and rhythmical body swaying in vertical or horizontal direction etc. In the paper the mathematical models of the Ground Reaction Forces (GRFs) generated during squats have been presented. Elaborated models was compared to the GRFs measured during laboratory tests carried out by author in wide range of frequency using force platform. Moreover, the GRFs models were evaluated during dynamic numerical analyses and dynamic field tests of the exemplary structure (steel footbridge).
Arzeliès, Henri
1972-01-01
Relativistic Point Dynamics focuses on the principles of relativistic dynamics. The book first discusses fundamental equations. The impulse postulate and its consequences and the kinetic energy theorem are then explained. The text also touches on the transformation of main quantities and relativistic decomposition of force, and then discusses fields of force derivable from scalar potentials; fields of force derivable from a scalar potential and a vector potential; and equations of motion. Other concerns include equations for fields; transfer of the equations obtained by variational methods int
Normal dynamic deformation characteristics of non-consecutive jointed rock masses under impact loads
Zeng, Sheng; Jiang, Bowei; Sun, Bing
2017-08-01
In order to study deformation characteristics of non-consecutive single jointed rock masses under impact loads, we used the cement mortar materials to make simulative jointed rock mass samples, and tested the samples under impact loads by the drop hammer. Through analyzing the time-history signal of the force and the displacement, first we find that the dynamic compression displacement of the jointed rock mass is significantly larger than that of the intact jointless rock mass, the compression displacement is positively correlated with the joint length and the impact height. Secondly, the vertical compressive displacement of the jointed rock mass is mainly due to the closure of opening joints under small impact loads. Finally, the peak intensity of the intact rock mass is larger than that of the non-consecutive jointed rock mass and negatively correlated with the joint length under the same impact energy.
Dynamic array generation and pattern formation for optical tweezers
DEFF Research Database (Denmark)
Mogensen, P.C.; Glückstad, J.
2000-01-01
The generalised phase contrast approach is used for the generation of optical arrays of arbitrary beam shape, suitable for applications in optical tweezers for the manipulation of biological specimens. This approach offers numerous advantages over current techniques involving the use of computer......-generated holograms or diffractive optical elements. We demonstrate a low-loss system for generating intensity patterns suitable for the trapping and manipulation of small particles or specimens....
On quantum effects in the dynamics of macroscopic test masses
International Nuclear Information System (INIS)
Mueller-Ebhardt, Helge
2009-01-01
This thesis provides theoretically a link between the increase of the sensitivity of gravitational-wave detectors and the possibility of preparing macroscopic quantum states in such detectors. In the first part of this thesis, we theoretically explore the quantum measurement noise of an optical speed meter topology, the Sagnac interferometer, equipped with an additional detuned cavity at the output port. This detuned signal-recycling technique was already investigated when applying it to a Michelson interferometer and is used in the gravitational-wave detector GEO600. Together with the quantum noise analysis of the simple Sagnac interferometer, it is the basis of our study: we optimize the Sagnac interferometer's sensitivity towards the detection of a certain gravitational-wave source in the vicinity of a realistic classical noise environment. Motivated by the fact that the Michelson interferometer, as a position meter, with detuned signal-recycling can transduce the gravitational-wave strain into real mirror motion, we compare the transducer effect in a speed and in a position meter. Furthermore, we theoretically investigate the conditional output squeezing of a cavity which is detuned with respect to its carrier and its subcarrier. Therewith we pursue the theoretical analysis of the ponderomotive squeezer. With the knowledge gained in the first part about the quantum measurement process in laser interferometers, the second part of this thesis comprises a theoretical analysis of the conditonal state in positon and momentum of the interferometer's test masses. We motivate not to obtain the conditional states from a stochastic master equation but with the help of the so-called Wiener filtering method. Using this method, we calculate the most general expression for the conditional covariance matrix of the Gaussian state of a test mass under any linear Markovian measurement process. Then we specify to the interferometry and theoretically show under which circumstances
Aircraft dynamic loads generated in wake vortex encounters
Suñer Perucho, Carles
2014-01-01
The study illustrated in these pages was developed in the Structural Dynamics and Aeroelasticity Department of the Military Aircraft division of Airbus Defence and Space in Getafe, Madrid (Spain). That department is a multidisciplinary one involving several categories. Some of its competences are the analysis of impacts, acoustics and vibrations for the aircraft and all their systems. Also, the dynamic response of the aircraft to different events is part of the tasks for that department. It i...
Next generation extended Lagrangian first principles molecular dynamics.
Niklasson, Anders M N
2017-08-07
Extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] is formulated for general Hohenberg-Kohn density-functional theory and compared with the extended Lagrangian framework of first principles molecular dynamics by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. It is shown how extended Lagrangian Born-Oppenheimer molecular dynamics overcomes several shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while improving or maintaining important features of Car-Parrinello simulations. The accuracy of the electronic degrees of freedom in extended Lagrangian Born-Oppenheimer molecular dynamics, with respect to the exact Born-Oppenheimer solution, is of second-order in the size of the integration time step and of fourth order in the potential energy surface. Improved stability over recent formulations of extended Lagrangian Born-Oppenheimer molecular dynamics is achieved by generalizing the theory to finite temperature ensembles, using fractional occupation numbers in the calculation of the inner-product kernel of the extended harmonic oscillator that appears as a preconditioner in the electronic equations of motion. Material systems that normally exhibit slow self-consistent field convergence can be simulated using integration time steps of the same order as in direct Born-Oppenheimer molecular dynamics, but without the requirement of an iterative, non-linear electronic ground-state optimization prior to the force evaluations and without a systematic drift in the total energy. In combination with proposed low-rank and on the fly updates of the kernel, this formulation provides an efficient and general framework for quantum-based Born-Oppenheimer molecular dynamics simulations.
Tran Quoc, Tinh; Khong Trong, Toan; Luong Van, Hai
2018-04-01
In this paper, Improved Moving Element Method (IMEM) is used to analyze the dynamic response of Euler-Bernoulli beam structures on the dynamic foundation model subjected to the moving load. The effects of characteristic foundation model parameters such as Winkler stiffness, shear layer based on the Pasternak model, viscoelastic dashpot and characteristic parameter of mass on foundation. Beams are modeled by moving elements while the load is fixed. Based on the principle of the publicly virtual balancing and the theory of moving element method, the motion differential equation of the system is established and solved by means of the numerical integration based on the Newmark algorithm. The influence of mass on foundation and the roughness of the beam surface on the dynamic response of beam are examined in details.
Energy Technology Data Exchange (ETDEWEB)
Sethuraman, Latha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hayes, Austin [Rochester Institute of Technology
2017-11-09
As wind turbine blade diameters and tower height increase to capture more energy in the wind, higher structural loads results in more structural support material increasing the cost of scaling. Weight reductions in the generator transfer to overall cost savings of the system. Additive manufacturing facilitates a design-for-functionality approach, thereby removing traditional manufacturing constraints and labor costs. The most feasible additive manufacturing technology identified for large, direct-drive generators in this study is powder-binder jetting of a sand cast mold. A parametric finite element analysis optimization study is performed, optimizing for mass and deformation. Also, topology optimization is employed for each parameter-optimized design.The optimized U-beam spoked web design results in a 24 percent reduction in structural mass of the rotor and 60 percent reduction in radial deflection.
Third-generation effects on fermion mass predictions in supersymmetric grand unified theories
International Nuclear Information System (INIS)
Naculich, S.G.
1993-01-01
Relations among fermion masses and mixing angles at the scale of grand unification are modified at lower energies by renormalization group running induced by gauge and Yukawa couplings. In supersymmetric theories, the b quark and τ lepton Yukawa couplings, as well as the t quark coupling, may cause significant running if tanβ, the ratio of Higgs field expectation values, is large. We present approximate analytic expressions for the scaling factors for fermion masses and CKM matrix elements induced by all three third generation Yukawa couplings. We then determine how running caused by the third generation of fermions affects the predictions arising from three possible forms for the Yukawa coupling matrices at the GUT scale: the Georgi-Jarlskog, Giudice, and Fritzsch textures
Effects of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds
International Nuclear Information System (INIS)
Gerhold, Philipp; Kallarackal, Jim; Jansen, Karl
2010-12-01
We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying SU(2) L x U(1) Y symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations. (orig.)
Effects of a potential fourth fermion generation on the Higgs boson mass bounds
International Nuclear Information System (INIS)
Gerhold, Philipp; Kallarackal, Jim; Jansen, Karl
2010-12-01
We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying SU(2) L x U(1) Y symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations. (orig.)
Charged lepton flavor violation in a class of radiative neutrino mass generation models
Chowdhury, Talal Ahmed; Nasri, Salah
2018-04-01
We investigate the charged lepton flavor violating processes μ →e γ , μ →e e e ¯, and μ -e conversion in nuclei for a class of three-loop radiative neutrino mass generation models with electroweak multiplets of increasing order. We find that, because of certain cancellations among various one-loop diagrams which give the dipole and nondipole contributions in an effective μ e γ vertex and a Z-penguin contribution in an effective μ e Z vertex, the flavor violating processes μ →e γ and μ -e conversion in nuclei become highly suppressed compared to μ →e e e ¯ process. Therefore, the observation of such a pattern in LFV processes may reveal the radiative mechanism behind neutrino mass generation.
Higgs boson mass bounds in the presence of a very heavy fourth quark generation
International Nuclear Information System (INIS)
Gerhold, P.; Kallarackal, J.; DESY, Zeuthen; Jansen, K.
2010-11-01
We study the effect of a potential fourth quark generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying SU(2) L x U(1) Y symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations. (orig.)
Generating random numbers by means of nonlinear dynamic systems
Zang, Jiaqi; Hu, Haojie; Zhong, Juhua; Luo, Duanbin; Fang, Yi
2018-07-01
To introduce the randomness of a physical process to students, a chaotic pendulum experiment was opened in East China University of Science and Technology (ECUST) on the undergraduate level in the physics department. It was shown chaotic motion could be initiated through adjusting the operation of a chaotic pendulum. By using the data of the angular displacements of chaotic motion, random binary numerical arrays can be generated. To check the randomness of generated numerical arrays, the NIST Special Publication 800-20 method was adopted. As a result, it was found that all the random arrays which were generated by the chaotic motion could pass the validity criteria and some of them were even better than the quality of pseudo-random numbers generated by a computer. Through the experiments, it is demonstrated that chaotic pendulum can be used as an efficient mechanical facility in generating random numbers, and can be applied in teaching random motion to the students.
Effect of mass variation on dynamics of tethered system in orbital maneuvering
Sun, Liang; Zhao, Guowei; Huang, Hai
2018-05-01
In orbital maneuvering, the mass variation due to fuel consumption has an obvious impact on the dynamics of tethered system, which cannot be neglected. The contributions of the work are mainly shown in two aspects: 1) the improvement of the model; 2) the analysis of dynamics characteristics. As the mass is variable, and the derivative of the mass is directly considered in the traditional Lagrange equation, the expression of generalized force is complicated. To solve this problem, the coagulated derivative is adopted in the paper; besides, the attitude dynamics equations derived in this paper take into account the effect of mass variation and the drift of orbital trajectory at the same time. The bifurcation phenomenon, the pendular motion angular frequency, and amplitudes of tether vibration revealed in this paper can provide a reference for the parameters and controller design in practical engineering. In the article, a dumbbell model is adopted to analyze the dynamics of tethered system, in which the mass variation of base satellite is fully considered. Considering the practical application, the case of orbital transfer under a transversal thrust is mainly studied. Besides, compared with the analytical solutions of librational angles, the effects of mass variation on stability and librational characteristic are studied. Finally, in order to make an analysis of the effect on vibrational characteristic, a lumped model is introduced, which reveals a strong coupling of librational and vibrational characteristics.
The many-body content of quantum gauge theories and its connection to mass generation mechanisms
International Nuclear Information System (INIS)
Natoli, C.R.; Palumbo, F.
1985-01-01
The aim of the paper is to get more knowledge about many-body systems and their properties, about many-body content of quantum gauge theories and its connection with mass generation mechanisms. The way to achieve this is to perform the galilean limit of the relativistic theory by sending the speed of light c to infinity. This limiting process exposes the low energy behaviour of the relativistic theory
LipidPioneer : A Comprehensive User-Generated Exact Mass Template for Lipidomics
Ulmer, Candice Z.; Koelmel, Jeremy P.; Ragland, Jared M.; Garrett, Timothy J.; Bowden, John A.
2017-03-01
Lipidomics, the comprehensive measurement of lipid species in a biological system, has promising potential in biomarker discovery and disease etiology elucidation. Advances in chromatographic separation, mass spectrometric techniques, and novel substrate applications continue to expand the number of lipid species observed. The total number and type of lipid species detected in a given sample are generally indicative of the sample matrix examined (e.g., serum, plasma, cells, bacteria, tissue, etc.). Current exact mass lipid libraries are static and represent the most commonly analyzed matrices. It is common practice for users to manually curate their own lists of lipid species and adduct masses; however, this process is time-consuming. LipidPioneer, an interactive template, can be used to generate exact masses and molecular formulas of lipid species that may be encountered in the mass spectrometric analysis of lipid profiles. Over 60 lipid classes are present in the LipidPioneer template and include several unique lipid species, such as ether-linked lipids and lipid oxidation products. In the template, users can add any fatty acyl constituents without limitation in the number of carbons or degrees of unsaturation. LipidPioneer accepts naming using the lipid class level (sum composition) and the LIPID MAPS notation for fatty acyl structure level. In addition to lipid identification, user-generated lipid m/z values can be used to develop inclusion lists for targeted fragmentation experiments. Resulting lipid names and m/z values can be imported into software such as MZmine or Compound Discoverer to automate exact mass searching and isotopic pattern matching across experimental data.
Next Generation Extended Lagrangian Quantum-based Molecular Dynamics
Negre, Christian
2017-06-01
A new framework for extended Lagrangian first-principles molecular dynamics simulations is presented, which overcomes shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while maintaining important advantages of the unified extended Lagrangian formulation of density functional theory pioneered by Car and Parrinello three decades ago. The new framework allows, for the first time, energy conserving, linear-scaling Born-Oppenheimer molecular dynamics simulations, which is necessary to study larger and more realistic systems over longer simulation times than previously possible. Expensive, self-consinstent-field optimizations are avoided and normal integration time steps of regular, direct Born-Oppenheimer molecular dynamics can be used. Linear scaling electronic structure theory is presented using a graph-based approach that is ideal for parallel calculations on hybrid computer platforms. For the first time, quantum based Born-Oppenheimer molecular dynamics simulation is becoming a practically feasible approach in simulations of +100,000 atoms-representing a competitive alternative to classical polarizable force field methods. In collaboration with: Anders Niklasson, Los Alamos National Laboratory.
Energy Technology Data Exchange (ETDEWEB)
Neutz, Jochen; Koenig, Andreas [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany); Knauss, Helmut; Jordan, Sebastian; Roediger, Tim; Smorodsky, Boris [Universitaet Stuttgart (Germany). Institut fuer Aerodynamik und Gasdynamik; Bluemcke, Erich Walter [AUDI AG, Department I/EK-523, Ingolstadt (Germany)
2009-06-15
The mass flow characteristics of gas generators for airbag applications have to comply with a number of requirements for an optimal deployment of the airbag itself. Up to now, the mass flow was determined from pressure time histories of so-called can tests. This procedure suffers from the missing knowledge on the temperature of the generated gas entering the can. A new test setup described in this paper could overcome this problem by providing highly time resolved information on the gas's total temperature and the mass flow of the generator. The test setup consisted of a combustion chamber with a specially designed Laval nozzle in combination with a temperature sensor of high time resolution. The results showed a high time resolved temperature signal, which was disturbed by the formation of a slag layer on the sensor. Plausibility considerations with experimentally and thermodynamically determined combustion temperatures led to satisfying results for the overall temperature as characteristic parameter of airbag inflating gases flows from pyrotechnics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study
Energy Technology Data Exchange (ETDEWEB)
Cappers, Peter; Mills, Andrew; Goldman, Charles; Wiser, Ryan; Eto, Joseph H.
2011-09-10
This scoping study focuses on the policy issues inherent in the claims made by some Smart Grid proponents that the demand response potential of mass market customers which is enabled by widespread implementation of Advanced Metering Infrastructure (AMI) through the Smart Grid could be the “silver bullet” for mitigating variable generation integration issues. In terms of approach, we will: identify key issues associated with integrating large amounts of variable generation into the bulk power system; identify demand response opportunities made more readily available to mass market customers through widespread deployment of AMI systems and how they can affect the bulk power system; assess the extent to which these mass market Demand Response (DR) opportunities can mitigate Variable Generation (VG) integration issues in the near-term and what electricity market structures and regulatory practices could be changed to further expand the ability for DR to mitigate VG integration issues over the long term; and provide a qualitative comparison of DR and other approaches to mitigate VG integration issues.
Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms
Berhausen, Sebastian; Paszek, Stefan
2016-01-01
In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.
A dynamic isotope power system portable generator for the Moon or Mars
International Nuclear Information System (INIS)
Johnson, R.A.; Hunt, M.E.; Mason, L.S.
1991-01-01
The Dynamic Isotope Power Systems (DIPS) Demonstration Program is focused on a standardized 2.5 kWe portable generator for multipole uses on the Lunar or Martian surface. A variety of potential remote or mobile applications has been identified by the National Aeronautics and Space Administration (NASA). These applications include remote power to science packages, surface rovers for both short and extended duration missions, and back up to central base power. In this paper, reviews conducted on alternative power sources for these applications are described. These include the comparison of DIPS to regenerative fuel cells (RFCs) related to such things as mass, complexity, and life cycle costs, and concluded that each power source has application. Recent work is presented refining the 2.5 kWe design to assure compatibility with the Martian environment while imposing only a minor mass penalty on Lunar operations. This was accomplished by limiting temperatures, except in the heat source unit (HSU), to the nonrefractory materials regime and protecting the necessary refractories in the HSU from the environment. Design changes to the HSU are described. Finally, work related to recent concerns regarding astronaut radiation doses is described. This work includes the bases for the calculations to determine the necessary shielding or operational limitations
Dynamic Modeling and Grid Interaction of a Tidal and River Generator
Energy Technology Data Exchange (ETDEWEB)
Muljadi, Eduard; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath
2017-07-13
This presentation provides a high-level overview of the deployment of a river generator installed in a small system. The turbine dynamics of a river generator, electrical generator, and power converter are modeled in detail. Various simulations can be exercised, and the impact of different control algorithms, failures of power switches, and corresponding impacts can be examined.
Body mass index and dynamic lung volumes in office workers
International Nuclear Information System (INIS)
Rasool, S.A.; Shirwany, A.K.
2012-01-01
To measure the association of body mass index (BMI) to lung volumes assessed by spirometer. Study Design: Cross-sectional analytical study. Place and Duration of Study: Department of Physiology and Cell Biology, University of Health Sciences, Lahore, from February to August 2009. Methodology: Two hundred and twenty-five apparently healthy adult office workers of either gender aged > 20 years were recruited. Height and weight were measured and BMI was calculated as kg/m2. Subjects were categorized as normal (BMI=18.5 to 24.9 kg/m2); overweight (BMI=25 to 29.9 kg/m2); and obese Class 1 (BMI=30 to 34.9 kg/m2) on the basis of BMI. Lung volumes were measured by digital spirometer and were reported as percentage of predicted values for forced vital capacity (FVC%), forced expiratory volume in first second (FEV1%) and ratio of FEV1 to FVC (FEV1:FVC). Groups were compared using t-test and ANOVA, correlation was assessed by Pearson's 'r'. Results: Significant differences in lung volumes were found in different BMI categories. Obese subjects had significantly lower FVC% (p < 0.0001), as well as significantly lower FEV1% (p = 0.003) as compared to normal subjects. There were significant linear relationships between obesity and PFTs. BMI had significant negative linear association with FVC% in overweight (r = -0.197) and obese (r = - 0.488); and with FEV1% in obese subjects (r = -0.510). Gender and age had no significant effect on mean values of PFTs. Conclusion: Obese individuals in this sample had significant decline in lung volumes. (author)
Sliding Mode Control for Mass Moment Aerospace Vehicles Using Dynamic Inversion Approach
Directory of Open Access Journals (Sweden)
Xiao-Yu Zhang
2013-01-01
Full Text Available The moving mass actuation technique offers significant advantages over conventional aerodynamic control surfaces and reaction control systems, because the actuators are contained entirely within the airframe geometrical envelope. Modeling, control, and simulation of Mass Moment Aerospace Vehicles (MMAV utilizing moving mass actuators are discussed. Dynamics of the MMAV are separated into two parts on the basis of the two time-scale separation theory: the dynamics of fast state and the dynamics of slow state. And then, in order to restrain the system chattering and keep the track performance of the system by considering aerodynamic parameter perturbation, the flight control system is designed for the two subsystems, respectively, utilizing fuzzy sliding mode control approach. The simulation results describe the effectiveness of the proposed autopilot design approach. Meanwhile, the chattering phenomenon that frequently appears in the conventional variable structure systems is also eliminated without deteriorating the system robustness.
Dynamical generation of a composite quark-lepton symmetry
International Nuclear Information System (INIS)
Yasue, Masaki.
1981-05-01
We demonstrate the possibility that a basic [SU(2)]sup(N) symmetry of N subconstituents, which describes particle and antiparticle transitions, generates at most an ''effective'' SO(2N) symmetry and at least an ''effective'' SU(N) x U(1) symmetry of composite quarks and leptons whose states are specified by the N different kinds of subconstituents. The generators of the ''effective'' symmetry, are identified by the correct algebraic properties specific to SO(2N) of composite operators constructed from the [SU(2)]sup(N)-operators acting on the composite quark-lepton states. The composite quarks and leptons are found to respect SO(4) x SO(6) or SU(2)sub(L) x U(1)sub(R) x SU(3)sub(c) x U(1)sub(B-L) according to a new selection rule, which are generated by the bilinear products of the raising and lowering operators of [SU(2)] 5 . This construction of the SO(4) x SO(6) generators allows us to uniquely define the five quantum numbers of that symmetry even at the subconstituent level. The full SO(10) generators can be also constructed; however, one needs a newly arranged [SU(2)] 5 symmetry only defined at the composite level, the generators of which turn out to be at most N body operators of the original [SU(2)] 5 . (author)
Role of particle masses in the magnetic field generation driven by the parity violating interaction
Energy Technology Data Exchange (ETDEWEB)
Dvornikov, Maxim, E-mail: maxdvo@izmiran.ru [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN), 142190 Troitsk, Moscow (Russian Federation); Physics Faculty, National Research Tomsk State University, 36 Lenin Avenue, 634050 Tomsk (Russian Federation); II. Institute for Theoretical Physics, University of Hamburg, 149 Luruper Chaussee, D-22761 Hamburg (Germany)
2016-09-10
Recently the new model for the generation of strong large scale magnetic fields in neutron stars, driven by the parity violating interaction, was proposed. In this model, the magnetic field instability results from the modification of the chiral magnetic effect in presence of the electroweak interaction between ultrarelativistic electrons and nucleons. In the present work we study how a nonzero mass of charged particles, which are degenerate relativistic electrons and nonrelativistic protons, influences the generation of the magnetic field in frames of this approach. For this purpose we calculate the induced electric current of these charged particles, electroweakly interacting with background neutrons and an external magnetic field, exactly accounting for the particle mass. This current is calculated by two methods: using the exact solution of the Dirac equation for a charged particle in external fields and computing the polarization operator of a photon in matter composed of background neutrons. We show that the induced current is vanishing in both approaches leading to the zero contribution of massive particles to the generated magnetic field. We discuss the implication of our results for the problem of the magnetic field generation in compact stars.
THz Generation Using Fluxon Dynamics in High Temperature Superconductors
DEFF Research Database (Denmark)
Pedersen, Niels Falsig; Madsen, S.
2009-01-01
We consider THz emission due to fluxon dynamics in a stack of inductively coupled long Josephson junctions connected electrically to a resonant cavity. By comparing to experiments on Josephson junction parametric amplifiers we consider the role of a negative resistance in connection with THz emis...
Fractal sets generated by chemical reactions discrete chaotic dynamics
International Nuclear Information System (INIS)
Gontar, V.; Grechko, O.
2007-01-01
Fractal sets composed by the parameters values of difference equations derived from chemical reactions discrete chaotic dynamics (DCD) and corresponding to the sequences of symmetrical patterns were obtained in this work. Examples of fractal sets with the corresponding symmetrical patterns have been presented
Generating Realistic Dynamic Prices and Services for the Smart Grid
Pagani, G. A.; Aiello, M.
2014-01-01
The smart grid promises to change the way people manage their energy needs, to facilitate the inclusion of small-scale renewable sources, and to open the energy market to all. One of the enabling instruments is the real-time pricing of energy at the retail level: dynamic and flexible tariffs will
Gravitational wave generated by mass ejection in protoneutron star neutrino burst
International Nuclear Information System (INIS)
Almeida, L. G.; Rodrigues, H.; Portes, D. JR.; Duarte, S. B.
2010-01-01
In this work we discuss the mechanism of mass ejection in protoneutron stars induced by diffusion of neutrinos. A dynamical calculation is employed in order to determine the amount of matter ejected and the properties of the remnant compact object [1]. The equations of state of this supra-nuclear regime [2] is properly linked with others describing the different sub-nuclear regimes of density [3, 4, 5]. For specified initial configurations of the protoneutron star, we solve numerically the set of equations of motion together with a schematic treatment of the neutrino transport through the dense stellar medium. We investigate the gravitational waves production accompanying the mass ejection induced by the neutrino burst. It is estimated the gravitational wave intensity and the detection of such wave by the existing detector or near future project for this purpose is discussed.
Novel model of stator design to reduce the mass of superconducting generators
Kails, Kevin; Li, Quan; Mueller, Markus
2018-05-01
High temperature superconductors (HTS), with much higher current density than conventional copper wires, make it feasible to develop very powerful and compact power generators. Thus, they are considered as one promising solution for large (10 + MW) direct-drive offshore wind turbines due to their low tower head mass. However, most HTS generator designs are based on a radial topology, which requires an excessive amount of HTS material and suffers from cooling and reliability issues. Axial flux machines on the other hand offer higher torque/volume ratios than the radial machines, which makes them an attractive option where space and transportation becomes an issue. However, their disadvantage is heavy structural mass. In this paper a novel stator design is introduced for HTS axial flux machines which enables a reduction in their structural mass. The stator is for the first time designed with a 45° angle that deviates the air gap closing forces into the vertical direction reducing the axial forces. The reduced axial forces improve the structural stability and consequently simplify their structural design. The novel methodology was then validated through an existing design of the HTS axial flux machine achieving a ∼10% mass reduction from 126 tonnes down to 115 tonnes. In addition, the air gap flux density increases due to the new claw pole shapes improving its power density from 53.19 to 61.90 W kg‑1. It is expected that the HTS axial flux machines designed with the new methodology offer a competitive advantage over other proposed superconducting generator designs in terms of cost, reliability and power density.
Mobile charge generation dynamics in P3HT: PCBM observed by time-resolved terahertz spectroscopy
DEFF Research Database (Denmark)
Cooke, D. G.; Krebs, Frederik C; Jepsen, Peter Uhd
2012-01-01
Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale.......Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale....
Grauer, Jared A.; Morelli, Eugene A.
2013-01-01
A nonlinear simulation of the NASA Generic Transport Model was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of dynamic models identified from flight data. Measurements from a typical system identification maneuver were systematically and progressively deteriorated and then used to estimate stability and control derivatives within a Monte Carlo analysis. Based on the results, recommendations were provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using other flight conditions, parameter estimation methods, and a full-scale F-16 nonlinear aircraft simulation were compared with these recommendations.
MSSM fine tuning problem and dynamical suppression of the Higgs mass parameters
International Nuclear Information System (INIS)
Kobayashi, Tatsuo; Terao, Haruhiko
2004-01-01
There have been several proposals for extension of the MSSM so as to ameliorate the fine tuning problem, which may be classified roughly into two categories; scenarios with enhanced quartic Higgs couplings and scenarios with radiatively stable Higgs soft masses. After a brief remark on some generic aspects of these approaches, we show a scenario with use of superconformal dynamics suppressing the Higgs mass parameters. (author)
MSSM fine tuning problem and dynamical suppression of the Higgs mass parameters
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Tatsuo [Kyoto Univ., Dept. of Physics, Kyoto (Japan); Terao, Haruhiko [Kanazawa Univ., Institute for Theoretical Physics, Kanazawa, Ishikawa (Japan)
2004-12-01
There have been several proposals for extension of the MSSM so as to ameliorate the fine tuning problem, which may be classified roughly into two categories; scenarios with enhanced quartic Higgs couplings and scenarios with radiatively stable Higgs soft masses. After a brief remark on some generic aspects of these approaches, we show a scenario with use of superconformal dynamics suppressing the Higgs mass parameters. (author)
Juhasz, Albert J.; Bloomfield, Harvey S.
1987-01-01
A combinatorial reliability approach was used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis was also performed, specifically for a 100-kWe nuclear Brayton power conversion system with parallel redundancy. Although this study was done for a reactor outlet temperature of 1100 K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.
Juhasz, A. J.; Bloomfield, H. S.
1985-01-01
A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.
High-voltage pulsed generator for dynamic fragmentation of rocks.
Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N
2010-10-01
A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.
High-voltage pulsed generator for dynamic fragmentation of rocks
Kovalchuk, B. M.; Kharlov, A. V.; Vizir, V. A.; Kumpyak, V. V.; Zorin, V. B.; Kiselev, V. N.
2010-10-01
A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ˜50 ns, current amplitude of ˜6 kA with the 40 Ω active load, and ˜20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.
CONFIRMATION OF SMALL DYNAMICAL AND STELLAR MASSES FOR EXTREME EMISSION LINE GALAXIES AT z ∼ 2
Energy Technology Data Exchange (ETDEWEB)
Maseda, Michael V.; Van der Wel, Arjen; Da Cunha, Elisabete; Rix, Hans-Walter [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Pacifici, Camilla [Yonsei University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of); Momcheva, Ivelina; Van Dokkum, Pieter; Nelson, Erica J. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Brammer, Gabriel B.; Grogin, Norman A.; Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Franx, Marijn; Fumagalli, Mattia; Patel, Shannon G. [Leiden Observatory, Leiden University, Leiden (Netherlands); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Kocevski, Dale D. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Lundgren, Britt F. [Department of Astronomy, University of Wisconsin, 475 N Charter Street, Madison, WI 53706 (United States); Marchesini, Danilo [Physics and Astronomy Department, Tufts University, Robinson Hall, Room 257, Medford, MA 02155 (United States); Skelton, Rosalind E. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Straughn, Amber N., E-mail: maseda@mpia.de [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); and others
2013-11-20
Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (∼50 km s{sup –1}) for a sample of 14 extreme emission line galaxies at redshifts 1.4 < z < 2.3. These measurements imply that the total dynamical masses of these systems are low (≲ 3 × 10{sup 9} M {sub ☉}). Their large [O III] λ5007 equivalent widths (500-1100 Å) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10{sup 8}-10{sup 9} M {sub ☉}, confirming the presence of a violent starburst. The dynamical masses represent the first such determinations for low-mass galaxies at z > 1. The stellar mass formed in this vigorous starburst phase represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.
Dynamic Session-Key Generation for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Chen Chin-Ling
2008-01-01
Full Text Available Abstract Recently, wireless sensor networks have been used extensively in different domains. For example, if the wireless sensor node of a wireless sensor network is distributed in an insecure area, a secret key must be used to protect the transmission between the sensor nodes. Most of the existing methods consist of preselecting keys from a key pool and forming a key chain. Then, the sensor nodes make use of the key chain to encrypt the data. However, while the secret key is being transmitted, it can easily be exposed during transmission. We propose a dynamic key management protocol, which can improve the security of the key juxtaposed to existing methods. Additionally, the dynamic update of the key can lower the probability of the key to being guessed correctly. In addition, with the new protocol, attacks on the wireless sensor network can be avoided.
Dynamic Session-Key Generation for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Cheng-Ta Li
2008-09-01
Full Text Available Recently, wireless sensor networks have been used extensively in different domains. For example, if the wireless sensor node of a wireless sensor network is distributed in an insecure area, a secret key must be used to protect the transmission between the sensor nodes. Most of the existing methods consist of preselecting m keys from a key pool and forming a key chain. Then, the sensor nodes make use of the key chain to encrypt the data. However, while the secret key is being transmitted, it can easily be exposed during transmission. We propose a dynamic key management protocol, which can improve the security of the key juxtaposed to existing methods. Additionally, the dynamic update of the key can lower the probability of the key to being guessed correctly. In addition, with the new protocol, attacks on the wireless sensor network can be avoided.
Generation and communication of dynamic maps using light projection
Busch, Steffen; Schlichting, Alexander; Brenner, Claus
2018-05-01
Many accidents are caused by miscommunication between traffic participants. Much research is being conducted in the area of car to car and car to infrastructure communication in order to eliminate this cause of accidents. How-ever, less attention is paid to the question how the behavior of a car can be communicated to pedestrians. Especially considering automated traffic, there is a lack of communication between cars and pedestrians. In this paper, we address the question how an autonomously driving car can inform pedestrians about its intentions. Especially in case of highly automated driving, making eye contact with a driver will give no clue about his or her intensions. We developed a prototype which continuously informs pedestrians about the intentions of the vehicle by projecting visual patterns onto the ground. Furthermore, the system communicates its interpretation of the observed situation to the pedestrians to warn them or to encourage them to perform a certain action. In order to communicate adaptively, the vehicle needs to develop an understanding of the dynamics of a city to know what to expect in certain situations and what speed is appropriate. To support this, we created a dynamic map, which estimates the number of pedestrians and cyclists in a certain area, which is then used to determine how `hazardous' the area is. This dynamic map is obtained from measurement data from many time instances, in contrast to the static car navigation maps, which are prevalent today. Apart from being used for communication purposes, the dynamic map can also influence the speed of a car, be it manually or autonomously driven. Adapting the speed in hazardous areas will avoid accidents where a car drives too fast, so that neither a human nor a computer-operated system would be able to stop in time.
Isolated sub-100-attosecond pulse generation via controlling electron dynamics
Lan, Pengfei; Lu, Peixiang; Cao, Wei; Li, Yuhua; Wang, Xinlin
2007-01-01
A new method to coherently control the electron dynamics is proposed using a few-cycle laser pulse in combination with a controlling field. It is shown that this method not only broadens the attosecond pulse bandwidth, but also reduces the chirp, then an isolated 80-as pulse is straightforwardly obtained and even shorter pulse is achievable by increasing the intensity of the controlling field. Such ultrashort pulses allow one to investigate ultrafast electronic processes which have never be a...
Drawing on Dynamic Local Knowledge through Student-Generated Photography
Coles-Ritchie, Marilee; Monson, Bayley; Moses, Catherine
2015-01-01
In this research, the authors explored how teachers using student-generated photography draw on local knowledge. The study draws on the framework of funds of knowledge to highlight the assets marginalized students bring to the classroom and the need for culturally relevant pedagogy to address the needs of a diverse public school population. The…
Mass exchange and angular distribution in a dynamical treatment of heavy ion collisions
International Nuclear Information System (INIS)
Ngo, C.; Hofmann, H.
1977-01-01
One presents a first numerical computation of the absolute value of the double differential cross section as a function of mass asymmetry and detection angle including a dynamical coupling between relative motion and mass asymmetry. One applies it to the 63 Cu+ 197 Au experiment at two different energies. The equation of motion used is a Fokker-Planck equation for distribution function in classical phase space. The coefficients needed are those known from classical model calculations, besides a friction coefficient introduced for the mass asymmetry degree. Encouraging agreement between the calculated and experimental curves is found
Dynamics of Dwarf Galaxies Disfavor Stellar-Mass Black Holes as Dark Matter.
Koushiappas, Savvas M; Loeb, Abraham
2017-07-28
We study the effects of black hole dark matter on the dynamical evolution of stars in dwarf galaxies. We find that mass segregation leads to a depletion of stars in the center of dwarf galaxies and the appearance of a ring in the projected stellar surface density profile. Using Segue 1 as an example we show that current observations of the projected surface stellar density rule out at the 99.9% confidence level the possibility that more than 6% of the dark matter is composed of black holes with a mass of few tens of solar masses.
Towards a canonical Fermi mass matrix for a pure generation structure
International Nuclear Information System (INIS)
Davidson, A.; Wali, K.C.
1981-01-01
Vertical constraints on the horizontal generation structure are discussed. The minimal electro/nuclear scheme for which the generation structure must be pure is identified to be the partially unified Pati-Salam SU(4)sub(C)xSU(2)sub(L)xSU(2)sub(R). SO(10) type unification furthermore requires the horizontal group factor to be axial. This in turn crucially affects the Yukawa couplings in such a way that a minimal Higgs system with oply two conventional scalars is capable of uniquely giving rise to the 'canonical' Fritzsch-type mass matrix, for any arbitrary number of fermionic families. The anomaly free equations then provide the desired one-to-one correspondence between the mass matrices in the two charged quark sectors. The derived horizontal quantum numbers suggest that the maximal horizontal group factor be SU(2), with the generations furnishing two neighbor j and j + 1/2 representations. Finally a careful phase analysis shows that the tree-level soft and superweak CP-violation solely reflects the non-Abelian character of the horizontal group, representing an induced internal rotation which is triggered by the phase elimination performed in the vertical sector. (author)
Mass Distribution in Rotating Thin-Disk Galaxies According to Newtonian Dynamics
Directory of Open Access Journals (Sweden)
James Q. Feng
2014-04-01
Full Text Available An accurate computational method is presented for determining the mass distribution in a mature spiral galaxy from a given rotation curve by applying Newtonian dynamics for an axisymmetrically rotating thin disk of finite size with or without a central spherical bulge. The governing integral equation for mass distribution is transformed via a boundary-element method into a linear algebra matrix equation that can be solved numerically for rotation curves with a wide range of shapes. To illustrate the effectiveness of this computational method, mass distributions in several mature spiral galaxies are determined from their measured rotation curves. All the surface mass density profiles predicted by our model exhibit approximately a common exponential law of decay, quantitatively consistent with the observed surface brightness distributions. When a central spherical bulge is present, the mass distribution in the galaxy is altered in such a way that the periphery mass density is reduced, while more mass appears toward the galactic center. By extending the computational domain beyond the galactic edge, we can determine the rotation velocity outside the cut-off radius, which appears to continuously decrease and to gradually approach the Keplerian rotation velocity out over twice the cut-off radius. An examination of circular orbit stability suggests that galaxies with flat or rising rotation velocities are more stable than those with declining rotation velocities especially in the region near the galactic edge. Our results demonstrate the fact that Newtonian dynamics can be adequate for describing the observed rotation behavior of mature spiral galaxies.
Efficiency Analysis of a Wave Power Generation System by Using Multibody Dynamics
International Nuclear Information System (INIS)
Kim, Min Soo; Sohn, Jeong Hyun; Kim, Jung Hee; Sung, Yong Jun
2016-01-01
The energy absorption efficiency of a wave power generation system is calculated as the ratio of the wave power to the power of the system. Because absorption efficiency depends on the dynamic behavior of the wave power generation system, a dynamic analysis of the wave power generation system is required to estimate the energy absorption efficiency of the system. In this study, a dynamic analysis of the wave power generation system under wave loads is performed to estimate the energy absorption efficiency. RecurDyn is employed to carry out the dynamic analysis of the system, and the Morison equation is used for the wave load model. According to the results, the lower the wave height and the shorter the period, the higher is the absorption efficiency of the system
Efficiency Analysis of a Wave Power Generation System by Using Multibody Dynamics
Energy Technology Data Exchange (ETDEWEB)
Kim, Min Soo; Sohn, Jeong Hyun [Pukyong National Univ., Busan (Korea, Republic of); Kim, Jung Hee; Sung, Yong Jun [INGINE Inc., Seoul (Korea, Republic of)
2016-06-15
The energy absorption efficiency of a wave power generation system is calculated as the ratio of the wave power to the power of the system. Because absorption efficiency depends on the dynamic behavior of the wave power generation system, a dynamic analysis of the wave power generation system is required to estimate the energy absorption efficiency of the system. In this study, a dynamic analysis of the wave power generation system under wave loads is performed to estimate the energy absorption efficiency. RecurDyn is employed to carry out the dynamic analysis of the system, and the Morison equation is used for the wave load model. According to the results, the lower the wave height and the shorter the period, the higher is the absorption efficiency of the system.
Isolated sub-100-as pulse generation via controlling electron dynamics
International Nuclear Information System (INIS)
Lan Pengfei; Lu Peixiang; Cao Wei; Li Yuhua; Wang Xinlin
2007-01-01
A method to coherently control electron dynamics is proposed using a few-cycle laser pulse in combination with a controlling field. It is shown that this method not only broadens the attosecond pulse bandwidth, but also reduces the chirp; thus an isolated 80-as pulse is straightforwardly obtained, and even shorter pulses are achievable by increasing the intensity of the controlling field. Such ultrashort pulses allow one to investigate ultrafast electronic processes. In addition, the few-cycle synthesized pulse is expected to be useful for manipulating a wide range of laser-atom interactions
Dynamic Analysis of Permanent Magnet Synchronous Generator with Power Electronics
Directory of Open Access Journals (Sweden)
OZCIRA, S.
2010-05-01
Full Text Available Permanent magnet DC motor-generators (PMDC, PMSG have been widely used in industrial and energy sectors recently. Power control of these systems can be achieved by controlling the output voltage. In this study, PMDC-PMSG systems are mathematically modeled and simulated in MATLAB and Simulink software. Then the results are discussed. A low power permanent magnet synchronous generator is driven by a permanent magnet DC motor and the output voltage is controlled by a frequency cycle-converter. The output of a half-wave uncontrolled rectifier is applied to an SPWM inverter and the power is supplied to a 300V, 50Hz load. The load which is connected to an LC filter is modeled by state-space equations. LC filter is utilized in order to suppress the voltage oscillations at the inverter output.
Dynamics of carbon abatement in the Second Generation Model
International Nuclear Information System (INIS)
Sands, Ronald D.
2004-01-01
The Second Generation Model (SGM) is a collection of computable-general-equilibrium models developed for analysis of policies to reduce greenhouse gas emissions. Behavior of the Second Generation Model, with respect to changes in carbon prices, can be summarized using marginal abatement cost curves. Marginal abatement costs vary over time, as capital stocks adjust to a new set of prices, and across countries, depending in part on the mix of fuels in the existing energy system. This paper documents the production structure in SGM, marginal abatement cost curves derived from SGM with constant-carbon-price experiments, an application to several Energy Modeling Forum scenarios, and a methodology for including carbon capture and disposal in SGM
The Dynamic Pricing of Next Generation Consumer Durables
Barry L. Bayus
1992-01-01
Learning curve effects, aspects of consumer demand models (e.g., reservation price distributions, intertemporal utility maximizing behavior), and competitive activity are reasons which have been offered to explain why prices of new durables decline over time. This paper presents an alternative rationale based on the buying behavior for products with overlapping replacement cycles (i.e., next generation products). A model for consumer sales of a new durable is developed by incorporating the re...
Oscillon dynamics and rogue wave generation in Faraday surface ripples.
Xia, H; Maimbourg, T; Punzmann, H; Shats, M
2012-09-14
We report new experimental results which suggest that the generation of extreme wave events in the Faraday surface ripples is related to the increase in the horizontal mobility of oscillating solitons (oscillons). The analysis of the oscillon trajectories in a horizontal plane shows that at higher vertical acceleration, oscillons move chaotically, merge and form enclosed areas on the water surface. The probability of the formation of such craters, which precede large wave events, increases with the increase in horizontal mobility.
Inan, Nagihan; Arslan, Arzu; Donmez, Muhammed; Sarisoy, Hasan Tahsin
2016-01-01
Background Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the differential diagnosis of benign and malignant lung masses. Patients and Methods Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cutoff value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the differential diagnosis of benign and malignant lung masses. PMID:27703654
Physical conditions, dynamics and mass distribution in the center of the galaxy
Genzel, R.; Townes, C. H.
1987-01-01
Investigations of the central 10 pc of the Galaxy, and conclusions on energetics, dynamics, and mass distribution derived from X and gamma ray measurements and from infrared and microwave studies, especially from spectroscopy, high resolution imaging, and interferometry are reviewed. Evidence for and against a massive black hole is analyzed.
Directory of Open Access Journals (Sweden)
Milosevic Zorica C.
2017-06-01
Full Text Available We aimed to analyse the morphokinetic features of breast fibrocystic changes (nonproliferative lesions, proliferative lesions without atypia and proliferative lesions with atypia presenting as a non-mass enhancement (NMEin dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI examination.
DYNAMICS OF METAPHORIC MODELLING OF THE CONCEPT OF TERRORISM IN AMERICAN MASS MEDIA DISCOURSE
Directory of Open Access Journals (Sweden)
Rykova, O.V.
2017-09-01
Full Text Available The topicality of the research in modern linguistics is defined by the importance of studying the problem of the dynamic nature of the concept content, the need to define the connection type between the concept and discourse as well as to reveal the dependence of the concept content and verbalization means from the type of discourse. The subject of the research is dynamic properties of the verbalization of a socially marked concept in American mass media discourse. The aim is to define the dynamics of structuring and explicating the knowledge about terrorism in mass media discourse. To reach the aim the following tasks are set: to determine the corpus of linguistic units which serve as verbalizers of the concept of terrorism in American mass media discourse; to define the dynamics of the verbal representation of the concept of terrorism in American mass media discourse as exemplified by metaphoric modelling. The practical applicability of the research consists in the possibility of using its main points and results in such academic courses as general linguistics, stylistics, cultural linguistics, special courses in cognitive linguistics, theory of conceptual metaphor, discourse study and in lexicographic practice.
Paas, L.J.; Bijmolt, T.H.A.; Vermunt, J.K.
2004-01-01
A recent development in marketing research concerns the incorporation of dynamics in consumer segmentation.This paper extends the latent class Markov model, a suitable technique for conducting dynamic segmentation, in order to facilitate lead generation.We demonstrate the application of the latent
Analyzing the requirements for mass production of small wind turbine generators
Anuskiewicz, T.; Asmussen, J.; Frankenfield, O.
Mass producibility of small wind turbine generators to give manufacturers design and cost data for profitable production operations is discussed. A 15 kW wind turbine generator for production in annual volumes from 1,000 to 50,000 units is discussed. Methodology to cost the systems effectively is explained. The process estimate sequence followed is outlined with emphasis on the process estimate sheets compiled for each component and subsystem. These data enabled analysts to develop cost breakdown profiles crucial in manufacturing decision-making. The appraisal also led to various design recommendations including replacement of aluminum towers with cost effective carbon steel towers. Extensive cost information is supplied in tables covering subassemblies, capital requirements, and levelized energy costs. The physical layout of the plant is depicted to guide manufacturers in taking advantage of the growing business opportunity now offered in conjunction with the national need for energy development.
Energy generation in convective shells of low mass, low metallicity stars
International Nuclear Information System (INIS)
Bazan, G.
1989-01-01
We report on the non-negligible energy generation from the 13 C neutron source and neutron capture reactions in low mass, low metallicity AGB stars. About 10 4 L circle-dot are generated within the thermal pulse convective shell by the combination of the 13 C(α, n) 16 O rate and the sum of the Y(Z,A)(n,γ)Y(Z,A + 1) reactions and beta decays. The inclusion of this energy source in an AGB thermal pulse evolution is shown to alter the evolution of the convective shell boundaries, and, hence, how the 13 C is ingested into the convective shell. Also, the duration of the pulse itself is reduced by the additional energy input. The nucleosynthetic consequences are discussed for these evolutionary changes. 17 refs., 5 figs
Dynamical interplay between pairing and quadrupole correlations in odd-mass nuclei
International Nuclear Information System (INIS)
Kaneko, Kazunari; Takada, Kenjiro; Sakata, Fumihiko; Tazaki, Shigeru.
1982-01-01
Study of the dynamical interplay between pairing and quadrupole correlations in odd-mass nuclei has been developed. One of the purposes of this paper is to predict that the new collective excited states may exist system-atically in odd-mass nuclei. Other purpose is to discuss a new collective band structure on the top of a unique-parity one-quasiparticle state. Through the numerical calculations, it has been clarified that the dynamical mutual interplay between the pairing and the quadrupole degrees of freedom played an important role in the odd-mass transitional nuclei to bring about the new type of collective states. The results of calculation were compared with the experimental data. (Kato, T.)
Dynamic Stability of Pipe Conveying Fluid with Crack and Attached Masses
International Nuclear Information System (INIS)
Ahn, Tae Soo; Yoon, Han Ik; Son, In Soo; Ahn, Sung Jin
2007-01-01
In this paper, the dynamic stability of a cracked simply supported pipe conveying fluid with an attached mass is investigated. Also, the effect of attached masses on the dynamic stability of a simply supported pipe conveying fluid is presented for the different positions and depth of the crack. Based on the Euler-Bernoulli beam theory, the equation of motion can be constructed by the energy expressions using extended Hamilton's principle. The crack section is represented by a local flexibility matrix connecting two undamaged pipe segments. The crack is assumed to be in the first mode of a fracture and to be always opened during the vibrations. Finally, the critical flow velocities and stability maps of the pipe conveying fluid are obtained by changing the attached masses and crack severity
PLASMA-WAVE GENERATION IN A DYNAMIC SPACETIME
Energy Technology Data Exchange (ETDEWEB)
Yang, Huan [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L2Y5 (Canada); Zhang, Fan [Gravitational Wave and Cosmology Laboratory, Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
2016-02-01
We propose a new electromagnetic (EM)-emission mechanism in magnetized, force-free plasma, which is driven by the evolution of the underlying dynamic spacetime. In particular, the emission power and angular distribution of the emitted fast-magnetosonic and Alfvén waves are separately determined. Previous numerical simulations of binary black hole mergers occurring within magnetized plasma have recorded copious amounts of EM radiation that, in addition to collimated jets, include an unexplained, isotropic component that becomes dominant close to the merger. This raises the possibility of multimessenger gravitational-wave and EM observations on binary black hole systems. The mechanism proposed here provides a candidate analytical characterization of the numerical results, and when combined with previously understood mechanisms such as the Blandford–Znajek process and kinetic-motion-driven radiation, it allows us to construct a classification of different EM radiation components seen in the inspiral stage of compact-binary coalescences.
Dynamic thermal signature prediction for real-time scene generation
Christie, Chad L.; Gouthas, Efthimios (Themie); Williams, Owen M.; Swierkowski, Leszek
2013-05-01
At DSTO, a real-time scene generation framework, VIRSuite, has been developed in recent years, within which trials data are predominantly used for modelling the radiometric properties of the simulated objects. Since in many cases the data are insufficient, a physics-based simulator capable of predicting the infrared signatures of objects and their backgrounds has been developed as a new VIRSuite module. It includes transient heat conduction within the materials, and boundary conditions that take into account the heat fluxes due to solar radiation, wind convection and radiative transfer. In this paper, an overview is presented, covering both the steady-state and transient performance.
Dynamical generation of hierarchy in GUTs with softly broken supersymmetry
International Nuclear Information System (INIS)
Tabata, K.; Umemura, I.; Yamamoto, K.
1983-01-01
Characteristic aspects of Dimopoulos-Georgi's mechanism for the hierarchy are investigated in a 'semi-realistic' SU(5) model by employing the renormalization group method. The hierarchy is really generated in a 'sick' theory by quantum resuscitation without any fine tuning of the coupling constants at Msub(W) approx.= 10 2 GeV. It can also be realized in a 'normal' theory by choosing the coupling constants suitably. In the latter case, the effective potential has two minima at X = 0 and Msub(G). Some suggestions are presented for constructing a realistic model. (orig.)
Grauer, Jared A.; Morelli, Eugene A.
2013-01-01
The NASA Generic Transport Model (GTM) nonlinear simulation was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of identified parameters in mathematical models describing the flight dynamics and determined from flight data. Measurements from a typical flight condition and system identification maneuver were systematically and progressively deteriorated by introducing noise, resolution errors, and bias errors. The data were then used to estimate nondimensional stability and control derivatives within a Monte Carlo simulation. Based on these results, recommendations are provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using additional flight conditions and parameter estimation methods, as well as a nonlinear flight simulation of the General Dynamics F-16 aircraft, were compared with these recommendations
Generation of clusters in complex dynamical networks via pinning control
International Nuclear Information System (INIS)
Li Kezan; Fu Xinchu; Small, Michael
2008-01-01
Many real-world networks show community structure, i.e., groups (or clusters) of nodes that have a high density of links within them but with a lower density of links between them. In this paper, by applying feedback injections to a fraction of network nodes, various clusters are synchronized independently according to the community structure generated by the group partition of the network (cluster synchronization). This control is achieved by pinning (i.e. applying linear feedback control) to a subset of the network nodes. Those pinned nodes are selected not randomly but according to the topological structure of communities of a given network. Specifically, for a given group partition of a network, those nodes with direct connections between groups must be pinned in order to achieve cluster synchronization. Both the local stability and global stability of cluster synchronization are investigated. Taking the tree-shaped network and the most modular network as two particular examples, we illustrate in detail how the pinning strategy influences the generation of clusters. The simulations verify the efficiency of the pinning schemes used in this paper
Dynamics of harmonic generation in atoms and molecules
International Nuclear Information System (INIS)
Boutu, W.
2007-09-01
Harmonics are generated when an ultra-short laser impulse with an energy of 10 14 W/cm 2 is focused on a gas jet. A radiation in the UV X range is then emitted in the direction of the incident laser beam. This radiation has a periodical spectral structure composed of odd harmonics of the fundamental frequency. The first part of this work is dedicated to the optimization of the harmonic radiation. We have studied an alternative and cheaper solution to the flexible mirror, we have used a set of concentric phase plates in order to control the spatial phase of the beam and create an enlarged square profile near the focusing spot. We show how different parameters like phase shift or luminous-flux density or jet position have an impact on the harmonic signal. This second part of this work deals with the generation of high order harmonics in N 2 and CO 2 molecules. The experimental setting is based on the RABITT method (reconstruction of the atto-second burst by interference of 2-photon transitions). We have observed the presence of a spectral minimum linked to a phenomena of quantum interferences between the molecule and the electron wave packet. Moreover, a shift in the spectral phase appears at the place of the interference. (A.C.)
The need for speed: escape velocity and dynamical mass measurements of the Andromeda galaxy
Kafle, Prajwal R.; Sharma, Sanjib; Lewis, Geraint F.; Robotham, Aaron S. G.; Driver, Simon P.
2018-04-01
Our nearest large cosmological neighbour, the Andromeda galaxy (M31), is a dynamical system, and an accurate measurement of its total mass is central to our understanding of its assembly history, the life-cycles of its satellite galaxies, and its role in shaping the Local Group environment. Here, we apply a novel approach to determine the dynamical mass of M31 using high-velocity Planetary Nebulae, establishing a hierarchical Bayesian model united with a scheme to capture potential outliers and marginalize over tracers unknown distances. With this, we derive the escape velocity run of M31 as a function of galactocentric distance, with both parametric and non-parametric approaches. We determine the escape velocity of M31 to be 470 ± 40 km s-1 at a galactocentric distance of 15 kpc, and also, derive the total potential of M31, estimating the virial mass and radius of the galaxy to be 0.8 ± 0.1 × 1012 M⊙ and 240 ± 10 kpc, respectively. Our M31 mass is on the low side of the measured range, this supports the lower expected mass of the M31-Milky Way system from the timing and momentum arguments, satisfying the H I constraint on circular velocity between 10 ≲ R/ kpc < 35, and agreeing with the stellar mass Tully-Fisher relation. To place these results in a broader context, we compare them to the key predictions of the ΛCDM cosmological paradigm, including the stellar-mass-halo-mass and the dark matter halo concentration-virial mass correlation, and finding it to be an outlier to this relation.
From high-scale leptogenesis to low-scale one-loop neutrino mass generation
Zhou, Hang; Gu, Pei-Hong
2018-02-01
We show that a high-scale leptogenesis can be consistent with a low-scale one-loop neutrino mass generation. Our models are based on the SU(3)c × SU(2)L × U(1)Y × U(1) B - L gauge groups. Except a complex singlet scalar for the U(1) B - L symmetry breaking, the other new scalars and fermions (one scalar doublet, two or more real scalar singlets/triplets and three right-handed neutrinos) are odd under an unbroken Z2 discrete symmetry. The real scalar decays can produce an asymmetry stored in the new scalar doublet which subsequently decays into the standard model lepton doublets and the right-handed neutrinos. The lepton asymmetry in the standard model leptons then can be partially converted to a baryon asymmetry by the sphaleron processes. By integrating out the heavy scalar singlets/triplets, we can realize an effective theory to radiatively generate the small neutrino masses at the TeV scale. Furthermore, the lightest right-handed neutrino can serve as a dark matter candidate.
A Case for Dynamic Reverse-code Generation to Debug Non-deterministic Programs
Directory of Open Access Journals (Sweden)
Jooyong Yi
2013-09-01
Full Text Available Backtracking (i.e., reverse execution helps the user of a debugger to naturally think backwards along the execution path of a program, and thinking backwards makes it easy to locate the origin of a bug. So far backtracking has been implemented mostly by state saving or by checkpointing. These implementations, however, inherently do not scale. Meanwhile, a more recent backtracking method based on reverse-code generation seems promising because executing reverse code can restore the previous states of a program without state saving. In the literature, there can be found two methods that generate reverse code: (a static reverse-code generation that pre-generates reverse code through static analysis before starting a debugging session, and (b dynamic reverse-code generation that generates reverse code by applying dynamic analysis on the fly during a debugging session. In particular, we espoused the latter one in our previous work to accommodate non-determinism of a program caused by e.g., multi-threading. To demonstrate the usefulness of our dynamic reverse-code generation, this article presents a case study of various backtracking methods including ours. We compare the memory usage of various backtracking methods in a simple but nontrivial example, a bounded-buffer program. In the case of non-deterministic programs such as this bounded-buffer program, our dynamic reverse-code generation outperforms the existing backtracking methods in terms of memory efficiency.
Reconfigurable Optical Interconnections Via Dynamic Computer-Generated Holograms
Liu, Hua-Kuang (Inventor); Zhou, Shao-Min (Inventor)
1996-01-01
A system is presented for optically providing one-to-many irregular interconnections, and strength-adjustable many-to-many irregular interconnections which may be provided with strengths (weights) w(sub ij) using multiple laser beams which address multiple holograms and means for combining the beams modified by the holograms to form multiple interconnections, such as a cross-bar switching network. The optical means for interconnection is based on entering a series of complex computer-generated holograms on an electrically addressed spatial light modulator for real-time reconfigurations, thus providing flexibility for interconnection networks for large-scale practical use. By employing multiple sources and holograms, the number of interconnection patterns achieved is increased greatly.
International Nuclear Information System (INIS)
Sieniutycz, S.; Berry, R.S.
1992-01-01
For coupled transfer of the energy and mass in a multicomponent system at mechanical equilibrium a simple thermodynamic theory is developed, and the damped wave equations of change are derived. We show that under nonstationary conditions, where relaxation of diffusive fluxes is essential, the evolution of the distributed coupled transfer of the energy and mass follows the path that minimizes the difference between the total entropy generated within the system and that exchanged by the system. The principle is also valid in the limit in which flux relaxation effects are negligible and the heat and mass transfer, whether steady or not, obeys Onsager's generalization of the Fourier and Fick laws. For coupled steady-state processes the principle goes into that of Onsager, yielding his phenomenological equations. In contrast to the local steady-state nature of Onsager's principle the new principle is global, valid for both stationary and transient situations, and requires no frozen fields. For an isolated, distributed system, in which transient relaxation to equilibrium is the only possible process, the principle implies the least possible increase of the system entropy between any two successive configurations
Beam dynamics problems for next generation linear colliders
International Nuclear Information System (INIS)
Yokoya, Kaoru
1990-01-01
The most critical issue for the feasibility of high-energy e + e - linear colliders is obviously the development of intense microwave power sources. Remaining problems, however, are not trivial and in fact some of them require several order-of-magnitude improvement from the existing SLC parameters. The present report summarizes the study status of the beam dynamics problems of high energy linear colliders with an exaggeration on the beam-beam phenomenon at the interaction region. There are four laboratories having linear collider plans, SLAC, CERN, Novosibirsk-Protovino, and KEK. The parameters of these projects scatter in some range but seem to converge slowly if one recalls the status five years ago. The beam energy will be below 500GeV. The basic requirements to the damping ring are the short damping time and small equilibrium emittance. All the proposed designs make use of tight focusing optics and strong wiggler magnets to meet these requirements and seem to have no major problems at least compared with other problems in the colliders. One of the major problems in the linac is the transverse beam blow-up due to the wake field created by the head of the bunch and, in the case of multiple bunches per pulse, by the preceeding bunches. (N.K.)
Response of borehole extensometers to explosively generated dynamic loads
International Nuclear Information System (INIS)
Patrick, W.C.; Brough, W.G.
1980-01-01
Commercially available, hydraulically anchored, multiple-point borehole extensometers (MPBX) were evaluated with respect to response to dynamic loads produced by explosions. This study is part of the DOE-funded Spent Fuel Test-Climax (SFT-C), currently being conducted in the Climax granitic stock at the Nevada Test Site. The SFT-C is an investigation of the feasibility of short-term storage and retrieval of spent nuclear reactor fuel assemblies at a plausible repository depth in granitic rock. Eleven spent fuel assemblies are stored at a depth of 420 m for three to five years, and will then be retrieved. MPBX units are used in the SFT-C to measure both excavation-induced and thermally induced rock displacements. Long-term reliability of extensometers in this hostile environment is essential in order to obtain valid data during the course of this test. Research to date shows conclusively that extensometers of this type continue to function reliably even though subjected to accelerations of 1.8 g; research also implies that they function well though subjected to accelerations in excess of 100 g. MPBX survivability during the first four months of testing at ambient temperatures was about 90 percent
International Nuclear Information System (INIS)
Quigg, Chris
2007-01-01
In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.
Robinson, Gail A; Spooner, Donna; Harrison, William J
2015-10-01
Frontal dynamic aphasia is characterised by a profound reduction in spontaneous speech despite well-preserved naming, repetition and comprehension. Since Luria (1966, 1970) designated this term, two main forms of dynamic aphasia have been identified: one, a language-specific selection deficit at the level of word/sentence generation, associated with left inferior frontal lesions; and two, a domain-general impairment in generating multiple responses or connected speech, associated with more extensive bilateral frontal and/or frontostriatal damage. Both forms of dynamic aphasia have been interpreted as arising due to disturbances in early prelinguistic conceptual preparation mechanisms that are critical for language production. We investigate language-specific and domain-general accounts of dynamic aphasia and address two issues: one, whether deficits in multiple conceptual preparation mechanisms can co-occur; and two, the contribution of broader cognitive processes such as energization, the ability to initiate and sustain response generation over time, to language generation failure. Thus, we report patient WAL who presented with frontal dynamic aphasia in the context of progressive supranuclear palsy (PSP). WAL was given a series of experimental tests that showed that his dynamic aphasia was not underpinned by a language-specific deficit in selection or in microplanning. By contrast, WAL presented with a domain-general deficit in fluent sequencing of novel thoughts. The latter replicated the pattern documented in a previous PSP patient (Robinson, et al., 2006); however, unique to WAL, generating novel thoughts was impaired but there was no evidence of a sequencing deficit because perseveration was absent. Thus, WAL is the first unequivocal case to show a distinction between novel thought generation and subsequent fluent sequencing. Moreover, WAL's generation deficit encompassed verbal and non-verbal responses, showing a similar (but more profoundly reduced) pattern
Coherency Identification of Generators Using a PAM Algorithm for Dynamic Reduction of Power Systems
Directory of Open Access Journals (Sweden)
Seung-Il Moon
2012-11-01
Full Text Available This paper presents a new coherency identification method for dynamic reduction of a power system. To achieve dynamic reduction, coherency-based equivalence techniques divide generators into groups according to coherency, and then aggregate them. In order to minimize the changes in the dynamic response of the reduced equivalent system, coherency identification of the generators should be clearly defined. The objective of the proposed coherency identification method is to determine the optimal coherent groups of generators with respect to the dynamic response, using the Partitioning Around Medoids (PAM algorithm. For this purpose, the coherency between generators is first evaluated from the dynamic simulation time response, and in the proposed method this result is then used to define a dissimilarity index. Based on the PAM algorithm, the coherent generator groups are then determined so that the sum of the index in each group is minimized. This approach ensures that the dynamic characteristics of the original system are preserved, by providing the optimized coherency identification. To validate the effectiveness of the technique, simulated cases with an IEEE 39-bus test system are evaluated using PSS/E. The proposed method is compared with an existing coherency identification method, which uses the K-means algorithm, and is found to provide a better estimate of the original system.
Exergetic analysis of a thermo-generator for automotive application: A dynamic numerical approach
Glavatskaya, O.; Goupil, C.; Bakkali, A. El; Shonda, O.
2012-06-01
It is well known that, when using a passenger car with an ICE (Internal Combustion Engine), only a fraction of the burnt fuel energy actually contributes to drive the vehicle. Typical passenger vehicle engines run about 25% efficiency while a great part of the remaining energy (about 40%), is lost through the exhaust gases. This latter has a significant energy conversion potential since the temperature (more than 300°C) and the mass flow rate are high enough. Thus, direct conversion of heat into electricity is a credible option if the overall system is optimized. This point is crucial since the heat conversion into work process is very sensible to any mismatching of the different parts of the system, and very sensible significant to the possible varying working conditions. All these effects constitute irreversibility sources that degrade the overall efficiency. The exergetic analysis is known to be an efficient tool for finding the root causes of theses irreversible processes. In order to investigate the performance of our automotive thermo-generator we propose an analysis of the exergy flow through the system under dynamic conditions. Taking into account the different irreversible sources such as thermal conduction and Joule effect, we are able to localize and quantify the exergy losses. Then, in order to optimize the thermoelectric converter for a given vehicle, correct actions in term of design and working conditions can be proposed.
Light hadrons from N{sub f}=2+1+1 dynamical twisted mass fermions
Energy Technology Data Exchange (ETDEWEB)
Baron, R. [CEA, Centre de Saclay, Gif-sur-Yvette (France). IRFU/Service de Physique Nucleaire; Blossier, B.; Boucaud, P. [Paris 11 Univ., Orsay (FR). Lab. de Physique Theorique] (and others)
2011-01-15
We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N{sub f}=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{approx}0.06 fm, a{approx}0.08 fm and a{approx}0.09 fm with lattice sizes ranging from L{approx}1.9 fm to L{approx}3.9 fm. We perform a preliminary study of SU(2) chiral perturbation theory by combining our lattice data from these three values of the lattice spacing. (orig.)
Dynamic modeling of fixed-bed adsorption of flue gas using a variable mass transfer model
International Nuclear Information System (INIS)
Park, Jehun; Lee, Jae W.
2016-01-01
This study introduces a dynamic mass transfer model for the fixed-bed adsorption of a flue gas. The derivation of the variable mass transfer coefficient is based on pore diffusion theory and it is a function of effective porosity, temperature, and pressure as well as the adsorbate composition. Adsorption experiments were done at four different pressures (1.8, 5, 10 and 20 bars) and three different temperatures (30, 50 and 70 .deg. C) with zeolite 13X as the adsorbent. To explain the equilibrium adsorption capacity, the Langmuir-Freundlich isotherm model was adopted, and the parameters of the isotherm equation were fitted to the experimental data for a wide range of pressures and temperatures. Then, dynamic simulations were performed using the system equations for material and energy balance with the equilibrium adsorption isotherm data. The optimal mass transfer and heat transfer coefficients were determined after iterative calculations. As a result, the dynamic variable mass transfer model can estimate the adsorption rate for a wide range of concentrations and precisely simulate the fixed-bed adsorption process of a flue gas mixture of carbon dioxide and nitrogen.
Numerical simulation of heavy ion charge generation and collection dynamics
International Nuclear Information System (INIS)
Dussault, H.; Howard, J.W. Jr.; Block, R.C.; Stapor, W.J.; Knudson, A.R.
1993-01-01
This paper describes a complete simulation approach to investigating the physics of heavy-ion charge generation and collection during a single event transient in a PN diode. The simulations explore the effects of different ion track models, applied biases, background dopings, and LET on the transient responses of a PN diode. The simulation results show that ion track structure and charge collection via diffusion-dominated processes play important roles in determining device transient responses. The simulations show no evidence of rapid charge collection in excess of that deposited in the device depletion region in typical funneling time frames (i.e., by time to peak current or in less than 500 ps). Further, the simulations clearly show that the device transient responses are not simple functions of the ion's incident LET. The simulation results imply that future studies and experiments should consider the effects of ion track structure in addition to LET and extend transient charge collection times to insure that reported charge collection efficiencies include diffusion-dominated collection processes
Multistrange Meson-Baryon Dynamics and Resonance Generation
Khemchandani, K. P.; Martínez Torres, A.; Hosaka, A.; Nagahiro, H.; Navarra, F. S.; Nielsen, M.
2018-05-01
In this talk I review our recent studies on meson-baryon systems with strangeness - 1 and - 2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to - 1 or - 2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness - 1, we find evidence for the existence of some hyperons such as: Λ(2000), Σ(1750), Σ(1940), Σ(2000). More recently, in the study of strangeness - 2 systems we have found two narrow resonances which can be related to Ξ (1690) and Ξ(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.
Dynamic characteristics of steam generator U-tubes with defect
International Nuclear Information System (INIS)
Jo, Jong Chull; Jhung, Myung Jo; Kim, Woong Sik; Kim, Hho Jung
2005-01-01
This study investigates the fluid elastic instability characteristics of steam generator (SG) U-tubes with defect and the safety assessment of the potential for fretting-wear damages caused by foreign object in operating nuclear power plants. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for the U-tubes either with axial or circumferential flaw with different sizes. Special emphases are on the effects of flaw orientation and size on the modal and instability characteristics of tubes, which are expressed in terms of the natural frequency, corresponding mode shape and stability ratio. Also, the wear rate of U-tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted, and discussed in this study is the effect of the flow velocity and vibration of the tube on the remaining life of the tube. In addition, addressed in this study is the effect of the internal pressure on the vibration and fretting-wear characteristics of the tube
Xiong, Jun Ying; Cai, Dong Jun; Chong, Qing Yu; Lee, Swin Hui; Chung, Neal Tai-Shung
2016-01-01
A comprehensive analysis of fluid motion, mass transport, thermodynamics and power generation during pressure retarded osmotic (PRO) processes was conducted. This work aims to (1) elucidate the fundamental relationship among various membrane
Directory of Open Access Journals (Sweden)
Mike D.R. Zhang
2001-01-01
Full Text Available In this paper, a method for analyzing the dynamic response of a structural system with variable mass, damping and stiffness is first presented. The dynamic equations of the structural system with variable mass and stiffness are derived according to the whole working process of a bridge bucket unloader. At the end of the paper, an engineering numerical example is given.
Aquino-Ortíz, E.; Valenzuela, O.; Sánchez, S. F.; Hernández-Toledo, H.; Ávila-Reese, V.; van de Ven, G.; Rodríguez-Puebla, A.; Zhu, L.; Mancillas, B.; Cano-Díaz, M.; García-Benito, R.
2018-06-01
We used ionized gas and stellar kinematics for 667 spatially resolved galaxies publicly available from the Calar Alto Legacy Integral Field Area survey (CALIFA) 3rd Data Release with the aim of studying kinematic scaling relations as the Tully & Fisher (TF) relation using rotation velocity, Vrot, the Faber & Jackson (FJ) relation using velocity dispersion, σ, and also a combination of Vrot and σ through the SK parameter defined as SK^2 = KV_{rot}^2 + σ ^2 with constant K. Late-type and early-type galaxies reproduce the TF and FJ relations. Some early-type galaxies also follow the TF relation and some late-type galaxies the FJ relation, but always with larger scatter. On the contrary, when we use the SK parameter, all galaxies, regardless of the morphological type, lie on the same scaling relation, showing a tight correlation with the total stellar mass, M⋆. Indeed, we find that the scatter in this relation is smaller or equal to that of the TF and FJ relations. We explore different values of the K parameter without significant differences (slope and scatter) in our final results with respect the case K = 0.5 besides than a small change in the zero point. We calibrate the kinematic SK^2 dynamical mass proxy in order to make it consistent with sophisticated published dynamical models within 0.15 dex. We show that the SK proxy is able to reproduce the relation between the dynamical mass and the stellar mass in the inner regions of galaxies. Our result may be useful in order to produce fast estimations of the central dynamical mass in galaxies and to study correlations in large galaxy surveys.
Attitude dynamics and control of a spacecraft using shifting mass distribution
Ahn, Young Tae
Spacecraft need specific attitude control methods that depend on the mission type or special tasks. The dynamics and the attitude control of a spacecraft with a shifting mass distribution within the system are examined. The behavior and use of conventional attitude control actuators are widely developed and performing at the present time. However, the advantage of a shifting mass distribution concept can complement spacecraft attitude control, save mass, and extend a satellite's life. This can be adopted in practice by moving mass from one tank to another, similar to what an airplane does to balance weight. Using this shifting mass distribution concept, in conjunction with other attitude control devices, can augment the three-axis attitude control process. Shifting mass involves changing the center-of-mass of the system, and/or changing the moments of inertia of the system, which then ultimately can change the attitude behavior of the system. This dissertation consists of two parts. First, the equations of motion for the shifting mass concept (also known as morphing) are developed. They are tested for their effects on attitude control by showing how shifting the mass changes the spacecraft's attitude behavior. Second, a method for optimal mass redistribution is shown using a combinatorial optimization theory under constraints. It closes with a simple example demonstrating an optimal reconfiguration. The procedure of optimal reconfiguration from one mass distribution to another to accomplish attitude control has been demonstrated for several simple examples. Mass shifting could work as an attitude controller for fine-tuning attitude behavior in small satellites. Various constraints can be applied for different situations, such as no mass shift between two tanks connected by a failed pipe or total amount of shifted mass per pipe being set for the time optimum solution. Euler angle changes influenced by the mass reconfiguration are accomplished while stability
Dynamical Formation of Low-mass Merging Black Hole Binaries like GW151226
Energy Technology Data Exchange (ETDEWEB)
Chatterjee, Sourav; Rodriguez, Carl L.; Kalogera, Vicky; Rasio, Frederic A., E-mail: sourav.chatterjee@northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) Physics and Astronomy, Northwestern University, Evanston, IL 60202 (United States)
2017-02-20
Using numerical models for star clusters spanning a wide range in ages and metallicities (Z) we study the masses of binary black holes (BBHs) produced dynamically and merging in the local universe ( z ≲ 0.2). After taking into account cosmological constraints on star formation rate and metallicity evolution, which realistically relate merger delay times obtained from models with merger redshifts, we show here for the first time that while old, metal-poor globular clusters can naturally produce merging BBHs with heavier components, as observed in GW150914, lower-mass BBHs like GW151226 are easily formed dynamically in younger, higher-metallicity clusters. More specifically, we show that the mass of GW151226 is well within 1 σ of the mass distribution obtained from our models for clusters with Z/Z{sub ⊙} ≳ 0.5. Indeed, dynamical formation of a system like GW151226 likely requires a cluster that is younger and has a higher metallicity than typical Galactic globular clusters. The LVT151012 system, if real, could have been created in any cluster with Z/Z{sub ⊙} ≲ 0.25. On the other hand, GW150914 is more massive (beyond 1 σ ) than typical BBHs from even the lowest-metallicity (Z/Z{sub ⊙} = 0.005) clusters we consider, but is within 2 σ of the intrinsic mass distribution from our cluster models with Z/Z{sub ⊙} ≲ 0.05; of course, detection biases also push the observed distributions toward higher masses.
SHOCK, Nonlinear Dynamic Structure Analysis, Spring and Mass Model, Runge-Kutta-Gill Method
International Nuclear Information System (INIS)
Gabrielson, V. K.
1981-01-01
1 - Description of problem or function: SHOCK calculates the dynamic response of a structure modeled as a spring-mass system having one or two degrees of freedom for each mass when subjected to specified environments. The code determines the behavior of each lumped mass (displacement, velocity, and acceleration for each degree of freedom) and the behavior of each spring or coupling (force, shear, moment, and displacement) as a function of time. Two types of models, axial, having one degree of freedom, and lateral, having two degrees of freedom at each mass can be processed. Damping can be included in all models and shock spectrums of responses can be obtained. 2 - Method of solution: Two methods of numerical integration of the second-order dynamic equations are provided: the Runge-Kutta-Gill method with variable step-size is recommended for highly nonlinear problems, and a variation of the Newmark-Beta method is available for use with large linear problems. 3 - Restrictions on the complexity of the problem: Maxima of: 100 masses, 200 springs or couplings. Complex arrangements of nonlinear options must be carefully checked by the user
Study on dynamic behavior of a shaft excavation through a faulted crystalline rock mass
International Nuclear Information System (INIS)
Hashizume, Shigeru; Matsui, Hiroya; Horiuchi, Yasuharu; Hata, Koji; Akiyoshi, Kenji; Sato, Shin; Shibata, Chihoko; Niunoya, Sumio; Noda, Masaru
2013-01-01
The 'Mizunami Underground Research Laboratory' has been studying and developing engineering technology for deep underground applications. These applications are multifaceted and are categorized as development of design and construction planning technology, development construction technology, development of countermeasure technology, and development of technology for construction and operation security. In this report, the dynamic behavior of shaft and the surrounding rock mass has been studied with respect to rock mass displacement and stress, the effect of using a concrete liner and excavating through faulted crystalline rock. (author)
Energy Technology Data Exchange (ETDEWEB)
Dunham, Michael M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 78, Cambridge, MA 02138 (United States); Arce, Héctor G. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Mardones, Diego [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Matthews, Brenda C. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada); Stutz, Amelia M. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Williams, Jonathan P., E-mail: mdunham@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
2014-03-01
We present a survey of 28 molecular outflows driven by low-mass protostars, all of which are sufficiently isolated spatially and/or kinematically to fully separate into individual outflows. Using a combination of new and archival data from several single-dish telescopes, 17 outflows are mapped in {sup 12}CO (2-1) and 17 are mapped in {sup 12}CO (3-2), with 6 mapped in both transitions. For each outflow, we calculate and tabulate the mass (M {sub flow}), momentum (P {sub flow}), kinetic energy (E {sub flow}), mechanical luminosity (L {sub flow}), and force (F {sub flow}) assuming optically thin emission in LTE at an excitation temperature, T {sub ex}, of 50 K. We show that all of the calculated properties are underestimated when calculated under these assumptions. Taken together, the effects of opacity, outflow emission at low velocities confused with ambient cloud emission, and emission below the sensitivities of the observations increase outflow masses and dynamical properties by an order of magnitude, on average, and factors of 50-90 in the most extreme cases. Different (and non-uniform) excitation temperatures, inclination effects, and dissociation of molecular gas will all work to further increase outflow properties. Molecular outflows are thus almost certainly more massive and energetic than commonly reported. Additionally, outflow properties are lower, on average, by almost an order of magnitude when calculated from the {sup 12}CO (3-2) maps compared to the {sup 12}CO (2-1) maps, even after accounting for different opacities, map sensitivities, and possible excitation temperature variations. It has recently been argued in the literature that the {sup 12}CO (3-2) line is subthermally excited in outflows, and our results support this finding.
Generation of artificial earthquakes for dynamic analysis of nuclear power plant
International Nuclear Information System (INIS)
Tsushima, Y.; Hiromatsu, T.; Abe, Y.; Tamaki, T.
1979-01-01
A procedure for generating artificial earthquakes for the purpose of the dynamic analysis of the nuclear power plant has been studied and relevant computer codes developed. This paper describes brieafly the generation procedure employed in the computer codes and also deals with the results of two artificial earthquakes generated as an example for input motions for the aseismic design of a BWR-type reactor building. Using one of the generated artificial earthquakes and two actually recorded earthquakes, non-linear responses of the reactor building were computed and the results were compared with each other. From this comparison, it has been concluded that the computer codes are practically usable and the generated artificial earthquakes are useful and powerful as input motions for dynamic analysis of a nuclear power plant. (author)
Overview of Ice-Sheet Mass Balance and Dynamics from ICESat Measurements
Zwally, H. Jay
2010-01-01
The primary purpose of the ICESat mission was to determine the present-day mass balance of the Greenland and Antarctic ice sheets, identify changes that may be occurring in the surface-mass flux and ice dynamics, and estimate their contributions to global sea-level rise. Although ICESat's three lasers were planned to make continuous measurements for 3 to 5 years, the mission was re-planned to operate in 33-day campaigns 2 to 3 times each year following failure of the first laser after 36 days. Seventeen campaigns were conducted with the last one in the Fall of 2009. Mass balance maps derived from measured ice-sheet elevation changes show that the mass loss from Greenland has increased significantly to about 170 Gt/yr for 2003 to 2007 from a state of near balance in the 1990's. Increased losses (189 Gt/yr) from melting and dynamic thinning are over seven times larger'than increased gains (25 gt/yr) from precipitation. Parts of the West Antarctic ice sheet and the Antarctic Peninsula are losing mass at an increasing rate, but other parts of West Antarctica and the East Antarctic ice sheet are gaining mass at an increasing rate. Increased losses of 35 Gt/yr in Pine Island, Thwaites-Smith, and Marie-Bryd.Coast are more than balanced by gains in base of Peninsula and ice stream C, D, & E systems. From the 1992-2002 to 2003-2007 period, the overall mass balance for Antarctica changed from a loss of about 60 Gt/yr to near balance or slightly positive.
Seismic structural response analysis using consistent mass matrices having dynamic coupling
International Nuclear Information System (INIS)
Shaw, D.E.
1977-01-01
The basis for the theoretical development of this paper is the linear matrix equations of motion for an unconstrained structure subject to support excitation. The equations are formulated in terms of absolute displacement, velocity and acceleration vectors. By means of a transformation of the absolute response vectors into displacements, velocities and accelerations relative to the support motions, the homogeneous equations become non-homogeneous and the non-homogeneous boundary conditions become homogeneous with relative displacements, velocities and accelerations being zero at support points. The forcing function or inertial loading vector is shown to consist of two parts. The first part is comprised of the mass matrix times the suppport acceleration function times a vector of structural displacements resulting from a unit vector of support displacements in the direction of excitation. This inertial loading corresponds to the classical seismic loading vector and is indeed the only loading vector for lumped-mass systems. The second part of he inertial loading vectors consists of the mass matrix times the support acceleration function times a vector of structural accelerations resulting from unit support accelerations in the direction of excitation. This term is not present in classical seismic analysis formulations and results from the presence of off-diagonal terms in the mass matrices which give rise to dynamic coupling through the mass matrix. Thus, for lumped-mass models, the classical formulation of the inertial loading vector is correct. However, if dynamic coupling terms are included through off-diagonal terms in the mass matrix, an additional inertia loading vector must be considered
Energy Technology Data Exchange (ETDEWEB)
Ansel' m, A A; D' yakonov, D I [AN SSSR, Leningrad. Inst. Yadernoj Fiziki
1975-01-01
The mechanism of dynamic spontaneous breaking of the Coleman-Weinberg gauge invariance is discussed in which scalar fields assume nonzero mean values owing to quantum effects in higher orders of the perturbation theory. Group renormalization methods are used to study scalar electrodynamics and gauge theories similar to that of Yang and Mills; for these gauge theories it is established that by choosing proper constants it is possible to combine the acquisition of a mass by particles, owing to a dynamic violation of symmetry, with the asymptotic freedom of the theory. The symmetry violation is found to be closely related to infrared poles observed in effective charge for asymptotically free theories. The emerging masses of particles automatically cover these poles. It is proved that physical results due to symmetry violation do not depend, at least in the first non-trivial order of the perturbation theory, on the initial gauging of vector fields.
Hook, Vivian; Bandeira, Nuno
2015-12-01
Neuropeptides regulate intercellular signaling as neurotransmitters of the central and peripheral nervous systems, and as peptide hormones in the endocrine system. Diverse neuropeptides of distinct primary sequences of various lengths, often with post-translational modifications, coordinate and integrate regulation of physiological functions. Mass spectrometry-based analysis of the diverse neuropeptide structures in neuropeptidomics research is necessary to define the full complement of neuropeptide signaling molecules. Human neuropeptidomics has notable importance in defining normal and dysfunctional neuropeptide signaling in human health and disease. Neuropeptidomics has great potential for expansion in translational research opportunities for defining neuropeptide mechanisms of human diseases, providing novel neuropeptide drug targets for drug discovery, and monitoring neuropeptides as biomarkers of drug responses. In consideration of the high impact of human neuropeptidomics for health, an observed gap in this discipline is the few published articles in human neuropeptidomics compared with, for example, human proteomics and related mass spectrometry disciplines. Focus on human neuropeptidomics will advance new knowledge of the complex neuropeptide signaling networks participating in the fine control of neuroendocrine systems. This commentary review article discusses several human neuropeptidomics accomplishments that illustrate the rapidly expanding diversity of neuropeptides generated by protease processing of pro-neuropeptide precursors occurring within the secretory vesicle proteome. Of particular interest is the finding that human-specific cathepsin V participates in producing enkephalin and likely other neuropeptides, indicating unique proteolytic mechanisms for generating human neuropeptides. The field of human neuropeptidomics has great promise to solve new mechanisms in disease conditions, leading to new drug targets and therapeutic agents for human
On the dynamics of non-stationary binary stellar system with non-isotropic mass flow
International Nuclear Information System (INIS)
Bekov, A.A.; Bejsekov, A.N.; Aldibaeva, L.T.
2006-01-01
The motion of test body in the external gravitational field of the binary stellar systems with slowly variable some physical parameters of radiating components is considered on the base of restricted nonstationary photo-gravitational three and two bodies problem with non-isotropic mass flow. The family of polar and coplanar solutions are obtained. The solutions give the possibility of the dynamical and structure interpretation of binary young evolving stars and galaxies. (author)
Dynamical and topological considerations in low and high mass diffractive dissociation
International Nuclear Information System (INIS)
Bishari, M.
1978-01-01
The topological structure of a given process completely specifies the 1/N dependence. However dynamics seems to be crucial in characterizing strongly interacting reactions, as illustrated in the study of elastic scattering, low mass diffraction and the triple pomeron mechanism. The ''1/N dual unitarization'' scheme is a viable framework for Gribov's Reggeon field theory, since it clarifies and determines the bare parameters of Gribov's Lagrangian. (author)
Energy Technology Data Exchange (ETDEWEB)
Tempel, J. van der; Molenaar, D.-P.
2002-07-01
Wind turbines for electricity production have two seemingly opposing constraints; they need to be structural secure yet of low cost. To meet the first constraint, it would be an obvious choice to design a stiff structure of consequently large mass but this would drive up the cost. By reducing the mass a more cost effective turbine can be realized. However, such lightweight structures are by definition more flexible. To design a cost effective flexible system, thorough understanding of the dynamics is essential. This paper reviews the theoretical basics of the dynamic design options and applies these to realistic situations, including offshore machines under wave action. The wind energy converter and the support structure form an integrated dynamic system that must be developed in mutual interdependency and close co-operation. This paper provides a contribution to this integration process by extending the design approach initiated in the Opti-OW ECS study and the work of Kuhn. (author)
Dynamical Mass Measurements of Contaminated Galaxy Clusters Using Support Distribution Machines
Ntampaka, Michelle; Trac, Hy; Sutherland, Dougal; Fromenteau, Sebastien; Poczos, Barnabas; Schneider, Jeff
2018-01-01
We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach. We create two mock catalogs from Multidark’s publicly available N-body MDPL1 simulation, one with perfect galaxy cluster membership infor- mation and the other where a simple cylindrical cut around the cluster center allows interlopers to contaminate the clusters. In the standard approach, we use a power-law scaling relation to infer cluster mass from galaxy line-of-sight (LOS) velocity dispersion. Assuming perfect membership knowledge, this unrealistic case produces a wide fractional mass error distribution, with a width E=0.87. Interlopers introduce additional scatter, significantly widening the error distribution further (E=2.13). We employ the support distribution machine (SDM) class of algorithms to learn from distributions of data to predict single values. Applied to distributions of galaxy observables such as LOS velocity and projected distance from the cluster center, SDM yields better than a factor-of-two improvement (E=0.67) for the contaminated case. Remarkably, SDM applied to contaminated clusters is better able to recover masses than even the scaling relation approach applied to uncon- taminated clusters. We show that the SDM method more accurately reproduces the cluster mass function, making it a valuable tool for employing cluster observations to evaluate cosmological models.
Modification of the Newtonian dynamics as a possible alternative to the hidden mass hypothesis1
International Nuclear Information System (INIS)
Milgrom, M.; The Institute for Advanced Study)
1983-01-01
I consider the possibility that there is not, in fact, much hidden mass in galaxies and galaxy systems. If a certain modified version of the Newtonian dynamics is used to describe the motion of bodies in a gravitational field (of a galaxy, say), the observational results are reproduced with no need to assume hidden mass in appreciable quantities. Various characteristics of galaxies result with no further assumptions. In the basis of the modification is the assumption that in the limit of small acceleration a 0 , the acceleration of a particle at distance r from a mass M satisfies approximately a 2 /a 0 roughly-equalMGr -2 , where a 0 is a constant of the dimensions of an acceleration. A success of this modified dynamics in explaining the data may be interpreted as implying a need to change the law of inertia in the limit of small accelerations or a more limited change of gravity alone. I discuss various observational constraints on possible theories for the modified dynamics from data which exist already and suggest other systems which may provide useful constraints
Dynamic analysis of floating wave energy generation system with mooring system
International Nuclear Information System (INIS)
Choi, Gyu Seok; Sohn, Jeong Hyun
2013-01-01
In this study, dynamic behaviors of a wave energy generation system (WEGS) that converts wave energy into electric energy are analyzed using multibody dynamics techniques. Many studies have focused on reducing the effects of a mooring system on the motion of a WEGS. Several kinematic constraints and force elements are employed in the modeling stage. Three dimensional wave load equations are used to implement wave loads. The dynamic behaviors of a WEGS are analyzed under several wave conditions by using MSC/ADAMS, and the rotating speed of the generating shaft is investigated for predicting the electricity capacity. The dynamic behaviors of a WEGS with a mooring system are compared with those of a WEGS without a mooring system. Stability evaluation of a WEGS is carried out through simulation under extreme wave load
Dynamic Characteristics of Steam Generator Tubes with Defect due to Wear
Energy Technology Data Exchange (ETDEWEB)
Park, Sangjin; Rhee, Huinam [Sunchon National Univ., Sunchon (Korea, Republic of); Yoon, Doo Byung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2013-05-15
These defects may affect the dynamic characteristics of tubes, and therefore, the vibrational behavior of the tube due to flow-induced loads can be varied. Change in the vibrational response of a tube may result in different wear characteristics from the design condition, which must be checked for both safety and economic point of view. This paper deals with the study on the effect of wears or cracks on the dynamic characteristics of steam generator tubes using finite element analysis. In this paper the effect of defects on the surface due to wear on the variation of dynamic characteristics of steam generator tubes was studied using the finite element analysis. The changes of natural frequencies and mode shapes can directly affect the flow-induced vibration response characteristics, therefore, they must be evaluated appropriately. The results in this study can be a good basis to estimate the FIV characteristics of the steam generator tubes having defects such as wear or crack.
Extension of the pseudo dynamic method to test structures with distributed mass
International Nuclear Information System (INIS)
Renda, V.; Papa, L.; Bellorini, S.
1993-01-01
The PsD method is a mixed numerical and experimental procedure. At each time step the dynamic deformation of the structure, computed by solving the equation of the motion for a given input signal, is reproduced in the laboratory by means of actuators attached to the sample at specific points. The reaction forces at those points are measured and used to compute the deformation for the next time step. The reaction forces being known, knowledge of the stiffness of the structure is not needed, so that the method can be effective also for deformations leading to strong nonlinear behaviour of the structure. On the contrary, the mass matrix and the applied forces must be well known. For this reason the PsD method can be applied without approximations when the masses can be considered as lumped at the testing points of the sample. The present work investigates the possibility to extend the PsD method to test structures with distributed mass. A standard procedure is proposed to provide an equivalent mass matrix and force vector reduced to the testing points and to verify the reliability of the model. The verification is obtained comparing the results of multi-degrees of freedom dynamic analysis, done by means of a Finite Elements (FE) numerical program, with a simulation of the PsD method based on the reduced degrees of freedom mass matrix and external forces, assuming in place of the experimental reactions, those computed with the general FE model. The method has been applied to a numerical simulation of the behaviour of a realistic and complex structure with distributed mass consisting of a masonry building of two floors. The FE model consists of about two thousand degrees of freedom and the condensation has been made for four testing points. A dynamic analysis has been performed with the general FE model and the reactions of the structure have been recorded in a file and used as input for the PsD simulation with the four degree of freedom model. The comparison between
The Dynamic Cross-Correlations between Mass Media News, New Media News, and Stock Returns
Directory of Open Access Journals (Sweden)
Zuochao Zhang
2018-01-01
Full Text Available We investigate the dynamic cross-correlations between mass media news, new media news, and stock returns for the SSE 50 Index in Chinese stock market by employing the MF-DCCA method. The empirical results show that (1 there exist power-law cross-correlations between two types of news as well as between news and its corresponding SSE 50 Index return; (2 the cross-correlations between mass media news and SSE 50 Index returns show larger multifractality and more complicated structures; (3 mass media news and new media news have both complementary and competitive relationships; (4 with the rolling window analysis, we further find that there is a general increasing trend for the cross-correlations between the two types of news as well as the cross-correlations between news and returns and this trend becomes more persistent over time.
The Dynamical Evolution of Stellar-Mass Black Holes in Dense Star Clusters
Morscher, Maggie
Globular clusters are gravitationally bound systems containing up to millions of stars, and are found ubiquitously in massive galaxies, including the Milky Way. With densities as high as a million stars per cubic parsec, they are one of the few places in the Universe where stars interact with one another. They therefore provide us with a unique laboratory for studying how gravitational interactions can facilitate the formation of exotic systems, such as X-ray binaries containing black holes, and merging double black hole binaries, which are produced much less efficiently in isolation. While telescopes can provide us with a snapshot of what these dense clusters look like at present, we must rely on detailed numerical simulations to learn about their evolution. These simulations are quite challenging, however, since dense star clusters are described by a complicated set of physical processes occurring on many different length and time scales, including stellar and binary evolution, weak gravitational scattering encounters, strong resonant binary interactions, and tidal stripping by the host galaxy. Until very recently, it was not possible to model the evolution of systems with millions of stars, the actual number contained in the largest clusters, including all the relevant physics required describe these systems accurately. The Northwestern Group's Henon Monte Carlo code, CMC, which has been in development for over a decade, is a powerful tool that can be used to construct detailed evolutionary models of large star clusters. With its recent parallelization, CMC is now capable of addressing a particularly interesting unsolved problem in astrophysics: the dynamical evolution of stellar black holes in dense star clusters. Our current understanding of the stellar initial mass function and massive star evolution suggests that young globular clusters may have formed hundreds to thousands of stellar-mass black holes, the remnants of stars with initial masses from 20 - 100
Recent advances in applying mass spectrometry and systems biology to determine brain dynamics.
Scifo, Enzo; Calza, Giulio; Fuhrmann, Martin; Soliymani, Rabah; Baumann, Marc; Lalowski, Maciej
2017-06-01
Neurological disorders encompass various pathologies which disrupt normal brain physiology and function. Poor understanding of their underlying molecular mechanisms and their societal burden argues for the necessity of novel prevention strategies, early diagnostic techniques and alternative treatment options to reduce the scale of their expected increase. Areas covered: This review scrutinizes mass spectrometry based approaches used to investigate brain dynamics in various conditions, including neurodegenerative and neuropsychiatric disorders. Different proteomics workflows for isolation/enrichment of specific cell populations or brain regions, sample processing; mass spectrometry technologies, for differential proteome quantitation, analysis of post-translational modifications and imaging approaches in the brain are critically deliberated. Future directions, including analysis of cellular sub-compartments, targeted MS platforms (selected/parallel reaction monitoring) and use of mass cytometry are also discussed. Expert commentary: Here, we summarize and evaluate current mass spectrometry based approaches for determining brain dynamics in health and diseases states, with a focus on neurological disorders. Furthermore, we provide insight on current trends and new MS technologies with potential to improve this analysis.
Dynamical Masses of Cool White Dwarfs in Double-Degenerate Visual Binaries
Bond, Howard E.; Nelan, E. P.; Schaefer, G.
2014-01-01
The cool white dwarfs (WDs) WD 1639+153 and WD 1818+126 were originally resolved into close visual binaries containing two WDs each during a survey with the Hubble Space Telescope (HST) and its Fine Guidance Sensors (FGS). Follow up FGS observations of these two double-degenerate (DD) systems, along with the previously known DD G 107-70, have yielded the orbital elements of all three visual binaries. We find orbital periods of 3.88 yr, 12.19 yr, and 18.84 yr for WD 1639+153, WD 1818+126, and G 107-70, respectively. Moreover, for each of the systems we have been observing nearby field stars with FGS1r in POS mode to determine the local inertial reference frame, from which we obtain the parallax and proper motion of the DD, along with the motion of each WD about its system barycenter. This leads directly to a dynamical mass for each WD. We have also used HST STIS observations to obtain individual spectra of each of the six WDs, which provide the effective temperature and subclass of each WD. This provides insight into the cooling age of each star. From the cooling ages and dynamical masses, we obtain constraints on the initial-mass/final-mass relation for WD stars.
A Comparison of Three Random Number Generators for Aircraft Dynamic Modeling Applications
Grauer, Jared A.
2017-01-01
Three random number generators, which produce Gaussian white noise sequences, were compared to assess their suitability in aircraft dynamic modeling applications. The first generator considered was the MATLAB (registered) implementation of the Mersenne-Twister algorithm. The second generator was a website called Random.org, which processes atmospheric noise measured using radios to create the random numbers. The third generator was based on synthesis of the Fourier series, where the random number sequences are constructed from prescribed amplitude and phase spectra. A total of 200 sequences, each having 601 random numbers, for each generator were collected and analyzed in terms of the mean, variance, normality, autocorrelation, and power spectral density. These sequences were then applied to two problems in aircraft dynamic modeling, namely estimating stability and control derivatives from simulated onboard sensor data, and simulating flight in atmospheric turbulence. In general, each random number generator had good performance and is well-suited for aircraft dynamic modeling applications. Specific strengths and weaknesses of each generator are discussed. For Monte Carlo simulation, the Fourier synthesis method is recommended because it most accurately and consistently approximated Gaussian white noise and can be implemented with reasonable computational effort.
Analysis of Foot Slippage Effects on an Actuated Spring-Mass Model of Dynamic Legged Locomotion
Directory of Open Access Journals (Sweden)
Yizhar Or
2016-04-01
Full Text Available The classical model of spring-loaded inverted pendulum (SLIP and its extensions have been widely accepted as a simple description of dynamic legged locomotion at various scales in humans, legged robots and animals. Similar to the majority of models in the literature, the SLIP model assumes ideal sticking contact of the foot. However, there are practical scenarios of low ground friction that causes foot slippage, which can have a significant influence on dynamic behaviour. In this work, an extension of the SLIP model with two masses and torque actuation is considered, which accounts for possible slippage under Coulomb's friction law. The hybrid dynamics of this model is formulated and numerical simulations under representative parameter values reveal several types of stable periodic solutions with stick-slip transitions. Remarkably, it is found that slippage due to low friction can sometimes increase average speed and improve energetic efficiency by significantly reducing the mechanical cost of transport.
Investigation of dynamic characteristics of shells with holes and added mass
Directory of Open Access Journals (Sweden)
Seregin Sergey Valer’evich
2014-04-01
Full Text Available Thin cylindrical shells are widely used in construction, engineering and other industries. In case of designing a reservoir for the isothermal storage of liquefied gases such cases are inevitable, when housing requires various technical holes. A point wise added mass can appear into practice in the form of suspended spotlights, radar, architectural inclusions in buildings and structures of various purposes. It is known, that the dynamic asymmetry as an initial irregular geometric shape, including holes, and the added mass leads to specific effects in shells. In the paper the impact of a cut on the frequency and form of its own vibrations of thin circular cylindrical shells is theoretically examined with the help of the equations of linear shallow shell theory. For modal equations with Nav’e boundary conditions, we used the Bubnov - Galerkin method. The authors have expressed a formula for finding the lowest of the split-frequency vibrations of a shell with a cutout. It is stated, that in case of an appropriate choice of added mass value the lower frequencies are comparable with the case of vibrations of a shell with a hole. By numerical and experimental modeling and finite element method in the environment of MSC "Nastran" oscillation frequencies a shell supporting a concentrated mass and a shell with a cutout were compared. It is shown, that the results of the dynamic analysis of shells with holes with a suitable choice of the attached mass values are comparable with the results of the analysis of shells carrying a point mass. It was concluded that the edges in the holes, significantly affect the reduction in the lowest frequency, and need to be strengthened.
Crevecoeur, F; McIntyre, J; Thonnard, J-L; Lefèvre, P
2014-07-15
Moving requires handling gravitational and inertial constraints pulling on our body and on the objects that we manipulate. Although previous work emphasized that the brain uses internal models of each type of mechanical load, little is known about their interaction during motor planning and execution. In this report, we examine visually guided reaching movements in the horizontal plane performed by naive participants exposed to changes in gravity during parabolic flight. This approach allowed us to isolate the effect of gravity because the environmental dynamics along the horizontal axis remained unchanged. We show that gravity has a direct effect on movement kinematics, with faster movements observed after transitions from normal gravity to hypergravity (1.8g), followed by significant movement slowing after the transition from hypergravity to zero gravity. We recorded finger forces applied on an object held in precision grip and found that the coupling between grip force and inertial loads displayed a similar effect, with an increase in grip force modulation gain under hypergravity followed by a reduction of modulation gain after entering the zero-gravity environment. We present a computational model to illustrate that these effects are compatible with the hypothesis that participants partially attribute changes in weight to changes in mass and scale incorrectly their motor commands with changes in gravity. These results highlight a rather direct internal mapping between the force generated during stationary holding against gravity and the estimation of inertial loads that limb and hand motor commands must overcome. Copyright © 2014 the American Physiological Society.
Gluon transport equation with effective mass and dynamical onset of Bose–Einstein condensation
International Nuclear Information System (INIS)
Blaizot, Jean-Paul; Jiang, Yin; Liao, Jinfeng
2016-01-01
We study the transport equation describing a dense system of gluons, in the small scattering angle approximation, taking into account medium-generated effective masses of the gluons. We focus on the case of overpopulated systems that are driven to Bose–Einstein condensation on their way to thermalization. The presence of a mass modifies the dispersion relation of the gluon, as compared to the massless case, but it is shown that this does not change qualitatively the scaling behavior in the vicinity of the onset.
A high dynamic range pulse counting detection system for mass spectrometry.
Collings, Bruce A; Dima, Martian D; Ivosev, Gordana; Zhong, Feng
2014-01-30
A high dynamic range pulse counting system has been developed that demonstrates an ability to operate at up to 2e8 counts per second (cps) on a triple quadrupole mass spectrometer. Previous pulse counting detection systems have typically been limited to about 1e7 cps at the upper end of the systems dynamic range. Modifications to the detection electronics and dead time correction algorithm are described in this paper. A high gain transimpedance amplifier is employed that allows a multi-channel electron multiplier to be operated at a significantly lower bias potential than in previous pulse counting systems. The system utilises a high-energy conversion dynode, a multi-channel electron multiplier, a high gain transimpedance amplifier, non-paralysing detection electronics and a modified dead time correction algorithm. Modification of the dead time correction algorithm is necessary due to a characteristic of the pulse counting electronics. A pulse counting detection system with the capability to count at ion arrival rates of up to 2e8 cps is described. This is shown to provide a linear dynamic range of nearly five orders of magnitude for a sample of aprazolam with concentrations ranging from 0.0006970 ng/mL to 3333 ng/mL while monitoring the m/z 309.1 → m/z 205.2 transition. This represents an upward extension of the detector's linear dynamic range of about two orders of magnitude. A new high dynamic range pulse counting system has been developed demonstrating the ability to operate at up to 2e8 cps on a triple quadrupole mass spectrometer. This provides an upward extension of the detector's linear dynamic range by about two orders of magnitude over previous pulse counting systems. Copyright © 2013 John Wiley & Sons, Ltd.
Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani B
Bond, Howard E.; Bergeron, P.; Bédard, A.
2017-10-01
The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD’s mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M ⊙. In this paper, we use model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then compare these results with WD interior models. Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass-radius relation (MRR) is consistent with the star’s location in the mass-radius plane. This consistency is, however, achieved only if we assume a “thin” outer hydrogen layer, with q H = M H/M WD ≃ 10-10. We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of the expectation from canonical stellar-evolution theory of “thick” H layers with q H ≃ 10-4. The cooling age of 40 Eri B is ˜122 Myr, and its total age is ˜1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observations is excellent in all cases.
International Nuclear Information System (INIS)
Garcia, Humberto E.; Mohanty, Amit; Lin, Wen-Chiao; Cherry, Robert S.
2013-01-01
Dynamic analysis of HES (hybrid energy systems) under flexible operation and variable renewable generation is considered in this two-part communication to better understand various challenges and opportunities associated with the high system variability arising from the integration of renewable energy into the power grid. Advanced HES solutions are investigated in which multiple forms of energy commodities, such as electricity and chemical products, may be exchanged. In particular, a comparative dynamic cost analysis is conducted in this part two of the communication to determine best HES options. The cost function includes a set of metrics for computing fixed costs, such as fixed operations and maintenance and overnight capital costs, and also variable operational costs, such as cost of operational variability, variable operations and maintenance cost, and cost of environmental impact, together with revenues. Assuming natural gas, coal, and nuclear as primary heat sources, preliminary results identify the level of renewable penetration at which a given advanced HES option (e.g., a nuclear hybrid) becomes increasingly more economical than a traditional electricity-only generation solution. Conditions are also revealed under which carbon resources may be better utilized as carbon sources for chemical production rather than as combustion material for electricity generation. - Highlights: ► Dynamic analysis of HES to investigate challenges related to renewable penetration. ► Evaluation of dynamic synergies among HES constituents on system performance. ► Comparison of traditional versus advanced HES candidates. ► Dynamic cost analysis of HES candidates to investigate their economic viability. ► Identification of conditions under which an energy commodity may be best utilized
Cherubin, S.; Agosta, G.
2018-01-01
We present LIBVERSIONINGCOMPILER, a C++ library designed to support the dynamic generation of multiple versions of the same compute kernel in a HPC scenario. It can be used to provide continuous optimization, code specialization based on the input data or on workload changes, or otherwise to dynamically adjust the application, without the burden of a full dynamic compiler. The library supports multiple underlying compilers but specifically targets the LLVM framework. We also provide examples of use, showing the overhead of the library, and providing guidelines for its efficient use.
Mass profile and dynamical status of the z ~ 0.8 galaxy cluster LCDCS 0504
Guennou, L.; Biviano, A.; Adami, C.; Limousin, M.; Lima Neto, G. B.; Mamon, G. A.; Ulmer, M. P.; Gavazzi, R.; Cypriano, E. S.; Durret, F.; Clowe, D.; LeBrun, V.; Allam, S.; Basa, S.; Benoist, C.; Cappi, A.; Halliday, C.; Ilbert, O.; Johnston, D.; Jullo, E.; Just, D.; Kubo, J. M.; Márquez, I.; Marshall, P.; Martinet, N.; Maurogordato, S.; Mazure, A.; Murphy, K. J.; Plana, H.; Rostagni, F.; Russeil, D.; Schirmer, M.; Schrabback, T.; Slezak, E.; Tucker, D.; Zaritsky, D.; Ziegler, B.
2014-06-01
Context. Constraints on the mass distribution in high-redshift clusters of galaxies are currently not very strong. Aims: We aim to constrain the mass profile, M(r), and dynamical status of the z ~ 0.8 LCDCS 0504 cluster of galaxies that is characterized by prominent giant gravitational arcs near its center. Methods: Our analysis is based on deep X-ray, optical, and infrared imaging as well as optical spectroscopy, collected with various instruments, which we complemented with archival data. We modeled the mass distribution of the cluster with three different mass density profiles, whose parameters were constrained by the strong lensing features of the inner cluster region, by the X-ray emission from the intracluster medium, and by the kinematics of 71 cluster members. Results: We obtain consistent M(r) determinations from three methods based on kinematics (dispersion-kurtosis, caustics, and MAMPOSSt), out to the cluster virial radius, ≃1.3 Mpc and beyond. The mass profile inferred by the strong lensing analysis in the central cluster region is slightly higher than, but still consistent with, the kinematics estimate. On the other hand, the X-ray based M(r) is significantly lower than the kinematics and strong lensing estimates. Theoretical predictions from ΛCDM cosmology for the concentration-mass relation agree with our observational results, when taking into account the uncertainties in the observational and theoretical estimates. There appears to be a central deficit in the intracluster gas mass fraction compared with nearby clusters. Conclusions: Despite the relaxed appearance of this cluster, the determinations of its mass profile by different probes show substantial discrepancies, the origin of which remains to be determined. The extension of a dynamical analysis similar to that of other clusters of the DAFT/FADA survey with multiwavelength data of sufficient quality will allow shedding light on the possible systematics that affect the determination of mass
Solano, Javier; Duarte, José; Vargas, Erwin; Cabrera, Jhon; Jácome, Andrés; Botero, Mónica; Rey, Juan
2016-10-01
This paper addresses the Energetic Macroscopic Representation EMR, the modelling and the control of photovoltaic panel PVP generation systems for simulation purposes. The model of the PVP considers the variations on irradiance and temperature. A maximum power point tracking MPPT algorithm is considered to control the power converter. A novel EMR is proposed to consider the dynamic model of the PVP with variations in the irradiance and the temperature. The EMR is evaluated through simulations of a PVP generation system.
Dynamic Protective Control Strategy for Distributed Generation System with Fixed-speed Wind Turbines
Institute of Scientific and Technical Information of China (English)
2012-01-01
The characteristics of induction generator based fixed-speed wind turbines （FSWT） are investigated. The impacts of different execution time in protective operations are studied under different fauit duration and various wind velocity situations, e.g. , FSWT stabilities of load shedding in distribution systems. Based on this research, a dynamic protective control strategy for a distributed generation system （DGS） with FSWT is proposed. Finally, simulation results demonstrate the effectiveness of the strategy.
Simulation of generation and dynamics of polarization singularities with circular Airy beams.
Ye, Dong; Peng, Xinyu; Zhou, Muchun; Xin, Yu; Song, Minmin
2017-11-01
The generation and dynamics of polarization singularities have been underresearched for years, while the focusing property of the topological configuration has not been explored much. In this paper, we simulated the generation of low-order polarization singularities with a circular Airy beam and explored the focusing property of the synthetic light field during propagation due to the autofocusing of the component. Our work researched the focusing properties of the polarization singularity configuration, which may help to develop its application prospect.
Santos, Susana; Gaillard, Romy; Oliveira, Andreia; Barros, Henrique; Abrahamse-Berkeveld, Marieke; van der Beek, Eline M; Hofman, Albert; Jaddoe, Vincent WV
2017-01-01
Background Skinfold thickness enables the measurement of overall and regional subcutaneous fatness in infancy and may be associated with total and abdominal body fat in later childhood. We examined the associations of subcutaneous fat in infancy with total and abdominal fat at school-age. Methods In a population-based prospective cohort study among 821 children, we calculated total subcutaneous fat (sum of biceps, triceps, suprailiacal and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat) at 1.5 and 24 months. At 6 years, we measured fat mass index (total fat/height3), central-to-total fat ratio (trunk fat/total fat) and android-to-gynoid fat ratio (android fat/gynoid fat) by dual-energy X-ray absorptiometry and preperitoneal fat mass area by abdominal ultrasound. Results Central-to-total subcutaneous fat ratio at 1.5 months was positively associated with fat mass index and central-to-total fat ratio at 6 years, whereas both total and central-to-total subcutaneous fat ratio at 24 months were positively associated with all childhood adiposity measures (pfat at 24 months was associated with an increased risk of childhood overweight (Odds Ratio 1.70 [95% Confidence Interval 1.36, 2.12]). These associations were weaker than those for body mass index and stronger among girls than boys. Conclusions Subcutaneous fat in infancy is positively associated with total and abdominal fat at school-age. Our results also suggest that skinfold thicknesses add little value to estimate later body fat, as compared to body mass index. PMID:27225335
Santos, Susana; Gaillard, Romy; Oliveira, Andreia; Barros, Henrique; Abrahamse-Berkeveld, Marieke; van der Beek, Eline M; Hofman, Albert; Jaddoe, Vincent W V
2016-09-01
Skinfold thickness enables the measurement of overall and regional subcutaneous fatness in infancy and may be associated with total and abdominal body fat in later childhood. We examined the associations of subcutaneous fat in infancy with total and abdominal fat at school-age. In a population-based prospective cohort study among 821 children, we calculated total subcutaneous fat (sum of biceps, triceps, suprailiacal, and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat) at 1.5 and 24 months. At 6 years, we measured fat mass index (total fat/height(3) ), central-to-total fat ratio (trunk fat/total fat), and android-to-gynoid fat ratio (android fat/gynoid fat) by dual-energy X-ray absorptiometry and preperitoneal fat mass area by abdominal ultrasound. Central-to-total subcutaneous fat ratio at 1.5 months was positively associated with fat mass index and central-to-total fat ratio at 6 years, whereas both total and central-to-total subcutaneous fat ratio at 24 months were positively associated with all childhood adiposity measures. A 1-standard-deviation scores higher total subcutaneous fat at 24 months was associated with an increased risk of childhood overweight (odds ratio 1.70, 95% confidence interval 1.36, 2.12). These associations were weaker than those for body mass index and stronger among girls than boys. Subcutaneous fat in infancy is positively associated with total and abdominal fat at school-age. Our results also suggest that skinfold thicknesses add little value to estimate later body fat, as compared with body mass index. © 2016 John Wiley & Sons Ltd.
Dynamics calculation with variable mass of mountain self-propelled chassis
Directory of Open Access Journals (Sweden)
R.M. Makharoblidze
2016-12-01
Full Text Available Many technological processes in the field of agricultural production mechanization, such as a grain crop, planting root-tuber fruits, fertilizing, spraying and dusting, pressing feed materials, harvesting of various cultures, etc. are performed by the machine-tractor units with variable mass of links or processed media and materials. In recent years, are also developing the systems of automatic control, adjusting and control of technological processes and working members in agriculture production. Is studied the dynamics of transition processes of mountain self-propelled chassis with variable mass at real change disconnect or joining masses that is most often used in the function of movement (m(t = ctm(t = ct. Are derived the formulas of change of velocity of movement on displacement of unit and is defined the dependence of this velocity on the tractor and technological machine performance, with taking into account the gradual increase or removing of agricultural materials masses. According to the equation is possible to define a linear movement of machine-tractor unit. According to the obtained expressions we can define the basic operating parameters of machine-tractor unit with variable mass. The results of research would be applied at definition of characteristics of units, at development of new agricultural tractors.
CFD Based Added Mass Prediction in Cruise Condition of Underwater Vehicle Dynamic
Agoes Moelyadi, Mochammad; Bambang Riswandi, Bagus
2018-04-01
One of the unsteady flow behavior on the hydrodynamic characteristics of underwater vehicle is the presence of added mass. In cruising conditions, the underwater vehicle may require the addition of speed or experience the disturbance in the form of unsteady flow so that cause the hydrodynamic interaction between the surface of the vehicle with the surrounding fluid. This leads to the rise of local velocity of flow and the great changes of hydrodynamic forces which are very influential on the stability of the underwater vehicle. One of the result is an additional force called added mass. It is very useful parameter to control underwater vehicle dynamic.This paper reports the research on the added mass coefficient of underwater vehicles obtained through the Computational Fluid Dynmaic (CFD) simulation method using CFX software. Added mass coefficient is calculated by performing an unsteady simulation or known as transient simulation. Computational simulations are based on the Reynold Average Navier- Stokes (RANS) equation solution. The simulated vehicle moves forward and backward according to the sinus function, with a frequency of 0.25 Hz, a 2 m amplitude, a cruising depth of 10 m below sea level, and Vcruise 1.54 m / s (Re = 9.000.000). Simulation result data includes velocity contour, variation of force and acceleration to frequency, and added mass coefficient.
FLARE-GENERATED TYPE II BURST WITHOUT ASSOCIATED CORONAL MASS EJECTION
Energy Technology Data Exchange (ETDEWEB)
Magdalenic, J.; Marque, C.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, SIDC, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Vrsnak, B. [Hvar Observatory, Faculty of Geodesy, Kaciceva 26, HR-10000 Zagreb (Croatia); Veronig, A., E-mail: Jasmina.Magdalenic@oma.be [IGAM/Kanzelhoehe Observatory, Institut of Physics, Universitaet Graz, Universitaetsplatz 5, A-8010 Graz (Austria)
2012-02-20
We present a study of the solar coronal shock wave on 2005 November 14 associated with the GOES M3.9 flare that occurred close to the east limb (S06 Degree-Sign E60 Degree-Sign ). The shock signature, a type II radio burst, had an unusually high starting frequency of about 800 MHz, indicating that the shock was formed at a rather low height. The position of the radio source, the direction of the shock wave propagation, and the coronal electron density were estimated using Nancay Radioheliograph observations and the dynamic spectrum of the Green Bank Solar Radio Burst Spectrometer. The soft X-ray, H{alpha}, and Reuven Ramaty High Energy Solar Spectroscopic Imager observations show that the flare was compact, very impulsive, and of a rather high density and temperature, indicating a strong and impulsive increase of pressure in a small flare loop. The close association of the shock wave initiation with the impulsive energy release suggests that the impulsive increase of the pressure in the flare was the source of the shock wave. This is supported by the fact that, contrary to the majority of events studied previously, no coronal mass ejection was detected in association with the shock wave, although the corresponding flare occurred close to the limb.
Fast evolution and waveform generator for extreme-mass-ratio inspirals in equatorial-circular orbits
International Nuclear Information System (INIS)
Han, Wen-Biao
2016-01-01
In this paper we discuss the development of a fast and accurate waveform model for the quasi-circular orbital evolution of extreme-mass-ratio inspirals (EMRIs). This model simply employs the data of a few numerical Teukoulsky-based energy fluxes and waveforms to fit out a set of polynomials for the entire fluxes and waveforms. These obtained polynomials are accurate enough in the entire evolution domain, and much more accurate than the resummation post-Newtonian (PN) energy fluxes and waveforms, especially when the spin of a black hole becomes large. The dynamical equation we adopted for orbital revolution is the effective-one-body (EOB) formalism. Because of the simplified expressions, the efficiency of calculating the orbital evolution with our polynomials is also better than the traditional method which uses the resummed PN analytical fluxes. Our model should be useful in calculations of waveform templates of EMRIs for gravitational wave (GW) detectors such as the evolved Laser Interferometer Space Antenna (eLISA). (paper)
International Nuclear Information System (INIS)
Cichy, K.; Jansen, K.; Shindler, A.; Forschungszentrum Juelich; Forschungszentrum Juelich
2013-12-01
We apply the spectral projector method, recently introduced by Giusti and Luescher, to compute the chiral condensate using N f =2 and N f =2+1+1 dynamical flavors of maximally twisted mass fermions. We present our results for several quark masses at three different lattice spacings which allows us to perform the chiral and continuum extrapolations. In addition we report our analysis on the O(a) improvement of the chiral condensate for twisted mass fermions. We also 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 flavors.
Bristow, Tony; Constantine, Jill; Harrison, Mark; Cavoit, Fabien
2008-04-01
Orthogonal-acceleration quadrupole time-of-flight (oa-QTOF) mass spectrometers, employed for accurate mass measurement, have been commercially available for well over a decade. A limitation of the early instruments of this type was the narrow ion abundance range over which accurate mass measurements could be made with a high degree of certainty. Recently, a new generation of oa-QTOF mass spectrometers has been developed and these allow accurate mass measurements to be recorded over a much greater range of ion abundances. This development has resulted from new ion detection technology and improved electronic stability or by accurate control of the number of ions reaching the detector. In this report we describe the results from experiments performed to evaluate the mass measurement performance of the Bruker micrOTOF-Q, a member of the new-generation oa-QTOFs. The relationship between mass accuracy and ion abundance has been extensively evaluated and mass measurement accuracy remained stable (+/-1.5 m m/z units) over approximately 3-4 orders of magnitude of ion abundance. The second feature of the Bruker micrOTOF-Q that was evaluated was the SigmaFit function of the software. This isotope pattern-matching algorithm provides an exact numerical comparison of the theoretical and measured isotope patterns as an additional identification tool to accurate mass measurement. The smaller the value, the closer the match between theoretical and measured isotope patterns. This information is then employed to reduce the number of potential elemental formulae produced from the mass measurements. A relationship between the SigmaFit value and ion abundance has been established. The results from the study for both mass accuracy and SigmaFit were employed to define the performance criteria for the micrOTOF-Q. This provided increased confidence in the selection of elemental formulae resulting from accurate mass measurements.
Compression dynamics of quasi-spherical wire arrays with different linear mass profiles
International Nuclear Information System (INIS)
Mitrofanov, K. N.; Aleksandrov, V. V.; Gritsuk, A. N.; Grabovski, E. V.; Frolov, I. N.; Laukhin, Ya. N.; Oleinik, G. M.; Ol’khovskaya, O. G.
2016-01-01
Results of experimental studies of the implosion of quasi-spherical wire (or metalized fiber) arrays are presented. The goal of the experiments was to achieve synchronous three-dimensional compression of the plasma produced in different regions of a quasi-spherical array into its geometrical center. To search for optimal synchronization conditions, quasi-spherical arrays with different initial profiles of the linear mass were used. The following dependences of the linear mass on the poloidal angle were used: m_l(θ) ∝ sin"–"1θ and m_l(θ) ∝ sin"–"2θ. The compression dynamics of such arrays was compared with that of quasi-spherical arrays without linear mass profiling, m_l(θ) = const. To verify the experimental data, the spatiotemporal dynamics of plasma compression in quasi-spherical arrays was studied using various diagnostics. The experiments on three-dimensional implosion of quasi-spherical arrays made it possible to study how the frozen-in magnetic field of the discharge current penetrates into the array. By measuring the magnetic field in the plasma of a quasi-spherical array, information is obtained on the processes of plasma production and formation of plasma flows from the wire/fiber regions with and without an additionally deposited mass. It is found that penetration of the magnetic flux depends on the initial linear mass profile m_l(θ) of the quasi-spherical array. From space-resolved spectral measurements and frame imaging of plasma X-ray emission, information is obtained on the dimensions and shape of the X-ray source formed during the implosion of a quasi-spherical array. The intensity of this source is estimated and compared with that of the Z-pinch formed during the implosion of a cylindrical array.
International Nuclear Information System (INIS)
Schröck, M.
2013-01-01
Within the framework of this thesis, the interrelation between the two characteristic phenomena of quantum chromodynamics (QCD), i.e., dynamical chiral symmetry breaking and confinement, is investigated. To this end, we apply lattice gauge field theory techniques and adopt a method to artificially restore the dynamically broken chiral symmetry. The low-mode part of the Dirac eigenspectrum is tied to the dynamical breaking of the chiral symmetry according to the Banks--Casher relation. Utilizing two-flavor dynamical lattice gauge field configurations, we construct valence quark propagators that exclude a variable sized part of the low-mode Dirac spectrum, with the aim of using these as an input for meson and baryon interpolating fields. Subsequently, we explore the behavior of ground and excited states of the low-mode truncated hadrons using the variational analysis method. We look for the existence of confined hadron states and extract effective masses where applicable. Moreover, we explore the evolution of the quark wavefunction renormalization function and the renormalization point invariant mass function of the quark propagator under Dirac low-mode truncation in a gauge fixed setting. Motivated by the necessity of fixing the gauge in the aforementioned study of the quark propagator, we also developed a flexible high performance code for lattice gauge fixing, accelerated by graphic processing units (GPUs) using NVIDIA CUDA (Compute Unified Device Architecture). Lastly, more related but unpublished work on the topic is presented. This includes a study of the locality violation of low-mode truncated Dirac operators, a discussion of the possible extension of the low-mode truncation method to the sea quark sector based on a reweighting scheme, as well as the presentation of an alternative way to restore the dynamically broken chiral symmetry. (author) [de
Dynamic Model of a Wind Turbine for the Electric Energy Generation
Directory of Open Access Journals (Sweden)
José de Jesús Rubio
2014-01-01
Full Text Available A novel dynamic model is introduced for the modeling of the wind turbine behavior. The objective of the wind turbine is the electric energy generation. The analytic model has the characteristic that considers a rotatory tower. Experiments show the validity of the proposed method.
The dynamic macroeconomic effects of tax policy in an overlapping generations model
Heijdra, BJ; Ligthart, JE
2000-01-01
The paper studies the dynamic allocation effects of tax policy within the context of an overlapping-generations model of the Blanchard-Yaari type. The model is extended to allow for endogenous labour supply and three tax instruments, viz. a capital tax, labour income tax, and consumption tax. Both
Point vortex modelling of the wake dynamics behind asymmetric vortex generator arrays
Baldacchino, D.; Simao Ferreira, C.; Ragni, D.; van Bussel, G.J.W.
2016-01-01
In this work, we present a simple inviscid point vortex model to study the dynamics of asymmetric vortex rows, as might appear behind misaligned vortex generator vanes. Starting from the existing solution of the in_nite vortex cascade, a numerical model of four base-vortices is chosen to represent
Global sensitivity analysis of the BSM2 dynamic influent disturbance scenario generator
DEFF Research Database (Denmark)
Flores-Alsina, Xavier; Gernaey, Krist V.; Jeppsson, Ulf
2012-01-01
This paper presents the results of a global sensitivity analysis (GSA) of a phenomenological model that generates dynamic wastewater treatment plant (WWTP) influent disturbance scenarios. This influent model is part of the Benchmark Simulation Model (BSM) family and creates realistic dry/wet weat...
Explicit symplectic algorithms based on generating functions for charged particle dynamics
Zhang, Ruili; Qin, Hong; Tang, Yifa; Liu, Jian; He, Yang; Xiao, Jianyuan
2016-07-01
Dynamics of a charged particle in the canonical coordinates is a Hamiltonian system, and the well-known symplectic algorithm has been regarded as the de facto method for numerical integration of Hamiltonian systems due to its long-term accuracy and fidelity. For long-term simulations with high efficiency, explicit symplectic algorithms are desirable. However, it is generally believed that explicit symplectic algorithms are only available for sum-separable Hamiltonians, and this restriction limits the application of explicit symplectic algorithms to charged particle dynamics. To overcome this difficulty, we combine the familiar sum-split method and a generating function method to construct second- and third-order explicit symplectic algorithms for dynamics of charged particle. The generating function method is designed to generate explicit symplectic algorithms for product-separable Hamiltonian with form of H (x ,p ) =pif (x ) or H (x ,p ) =xig (p ) . Applied to the simulations of charged particle dynamics, the explicit symplectic algorithms based on generating functions demonstrate superiorities in conservation and efficiency.
International Nuclear Information System (INIS)
Cassany, B.; Courchinoux, R.; Bertron, I.; Malaise, F.; Hebert, D.
2003-01-01
This paper shows how to use a pulsed electrons beam to simulate the dynamical fragmentation of copper sheets and to eject diamond, tantalum and tungsten micro-particulates at very high speed (∼1000 m/s). These experiments were performed with the electrons generator CESAR of CEA/CESTA (France). (J.S.)
International Nuclear Information System (INIS)
McDermid, Richard M.; Cappellari, Michele; Bayet, Estelle; Bureau, Martin; Davies, Roger L.; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Duc, Pierre-Alain; Crocker, Alison F.; Davis, Timothy A.; De Zeeuw, P. T.; Emsellem, Eric; Kuntschner, Harald; Khochfar, Sadegh; Krajnović, Davor; Morganti, Raffaella; Oosterloo, Tom; Naab, Thorsten
2014-01-01
We report on empirical trends between the dynamically determined stellar initial mass function (IMF) and stellar population properties for a complete, volume-limited sample of 260 early-type galaxies from the ATLAS 3D project. We study trends between our dynamically derived IMF normalization α dyn ≡ (M/L) stars /(M/L) Salp and absorption line strengths, and interpret these via single stellar population-equivalent ages, abundance ratios (measured as [α/Fe]), and total metallicity, [Z/H]. We find that old and alpha-enhanced galaxies tend to have on average heavier (Salpeter-like) mass normalization of the IMF, but stellar population does not appear to be a good predictor of the IMF, with a large range of α dyn at a given population parameter. As a result, we find weak α dyn -[α/Fe] and α dyn –Age correlations and no significant α dyn –[Z/H] correlation. The observed trends appear significantly weaker than those reported in studies that measure the IMF normalization via the low-mass star demographics inferred through stellar spectral analysis
Resonance Ionization Mass Spectrometry (RIMS): applications in spectroscopy and chemical dynamics
International Nuclear Information System (INIS)
Naik, P.D.; Kumar, Awadhesh; Upadhyaya, Hari; Bajaj, P.N.
2009-01-01
Resonance ionization is a photophysical process wherein electromagnetic radiation is used to ionize atoms, molecules, transient species, etc., by exciting them through their quantum states. The number of photons required to ionize depends on the species being investigated and energy of the photon. Once a charged particle is produced, it is easy to detect it with high efficiency. With the advent of narrow band high power pulsed and cw tunable dye lasers, it has blossomed into a powerful spectroscopic and analytical technique, commonly known as resonance ionization spectroscopy (RIS)/resonance enhanced multiphoton ionization (REMPI). The alliance of resonance ionization with mass spectrometry has grown into a still more powerful technique, known as resonance ionization mass spectrometry (RIMS), which has made significant contributions in a variety of frontier areas of research and development, such as spectroscopy, chemical dynamics, analytical chemistry, cluster science, surface science, radiochemistry, nuclear physics, biology, environmental science, material science, etc. In this article, we shall describe the application of resonance ionization mass spectrometry to spectroscopy of uranium and chemical dynamics of polyatomic molecules
Energy Technology Data Exchange (ETDEWEB)
McDermid, Richard M. [Department of Physics and Astronomy, Macquarie University, Sydney NSW 2109 (Australia); Cappellari, Michele; Bayet, Estelle; Bureau, Martin; Davies, Roger L. [Sub-Department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Alatalo, Katherine [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Blitz, Leo [Department of Astronomy, Campbell Hall, University of California, Berkeley, CA 94720 (United States); Bois, Maxime [Observatoire de Paris, LERMA and CNRS, 61 Av. de l' Observatoire, F-75014 Paris (France); Bournaud, Frédéric; Duc, Pierre-Alain [Laboratoire AIM Paris-Saclay, CEA/IRFU/SAp- CNRS-Université Paris Diderot, F-91191 Gif-sur-Yvette Cedex (France); Crocker, Alison F. [Ritter Astrophysical Observatory, University of Toledo, Toledo, OH 43606 (United States); Davis, Timothy A.; De Zeeuw, P. T.; Emsellem, Eric; Kuntschner, Harald [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Khochfar, Sadegh [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Krajnović, Davor [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Morganti, Raffaella; Oosterloo, Tom [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Naab, Thorsten, E-mail: richard.mcdermid@mq.edu.au [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching (Germany); and others
2014-09-10
We report on empirical trends between the dynamically determined stellar initial mass function (IMF) and stellar population properties for a complete, volume-limited sample of 260 early-type galaxies from the ATLAS{sup 3D} project. We study trends between our dynamically derived IMF normalization α{sub dyn} ≡ (M/L){sub stars}/(M/L){sub Salp} and absorption line strengths, and interpret these via single stellar population-equivalent ages, abundance ratios (measured as [α/Fe]), and total metallicity, [Z/H]. We find that old and alpha-enhanced galaxies tend to have on average heavier (Salpeter-like) mass normalization of the IMF, but stellar population does not appear to be a good predictor of the IMF, with a large range of α{sub dyn} at a given population parameter. As a result, we find weak α{sub dyn}-[α/Fe] and α{sub dyn} –Age correlations and no significant α{sub dyn} –[Z/H] correlation. The observed trends appear significantly weaker than those reported in studies that measure the IMF normalization via the low-mass star demographics inferred through stellar spectral analysis.
McDermid, Richard M.; Cappellari, Michele; Alatalo, Katherine; Bayet, Estelle; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Crocker, Alison F.; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie; Young, Lisa M.
2014-09-01
We report on empirical trends between the dynamically determined stellar initial mass function (IMF) and stellar population properties for a complete, volume-limited sample of 260 early-type galaxies from the ATLAS3D project. We study trends between our dynamically derived IMF normalization αdyn ≡ (M/L)stars/(M/L)Salp and absorption line strengths, and interpret these via single stellar population-equivalent ages, abundance ratios (measured as [α/Fe]), and total metallicity, [Z/H]. We find that old and alpha-enhanced galaxies tend to have on average heavier (Salpeter-like) mass normalization of the IMF, but stellar population does not appear to be a good predictor of the IMF, with a large range of αdyn at a given population parameter. As a result, we find weak αdyn-[α/Fe] and αdyn -Age correlations and no significant αdyn -[Z/H] correlation. The observed trends appear significantly weaker than those reported in studies that measure the IMF normalization via the low-mass star demographics inferred through stellar spectral analysis.
Energy Technology Data Exchange (ETDEWEB)
Ikeda, Osamu; Morishita, Shoji; Kido, Taeko; Kitajima, Mika; Okamura, Kenji; Fukuda, Seiji [Kumamoto Rosai Hospital, Yatsushiro (Japan); Yamashita, Yasuyuki; Takahashi, Mutsumasa
1998-07-01
To differentiate between malignant and benign breast masses using a compartmental analysis, 55 patients with breast masses (fibroadenoma, n=22; invasive ductal carcinoma, n=29; noninvasive ductal carcinoma, n=8) underwent Gd-DTPA enhanced dynamic MR imaging. Dynamic MR images obtained using two-dimensional fat-saturated fast multiplanar corrupted gradient echo technique over 10 minutes following bolus injection of Gd-DTPA. The triexponential concentration curve of Gd-DTPA was fitted to a theoretical model based on compartmental analysis. Using this method, the transfer constant (or permeability surface product per unit volume of component k) and f{sub 3}/f{sub 1}=f were measured, where f{sub 1} represents tumor vessel volume and f{sub 3} represents extracellular volume. The k value was significantly greater (p<0.01) for malignant tumors, and the k value seen in cases of noninvasive ductal carcinoma was less than that for invasive ductal carcinoma. The f value was significantly smaller (p<0.01) for malignant tumors, whereas the f value for noninvasive ductal carcinoma was not significantly different from that for invasive ductal carcinoma. We believe that this type of compartmental analysis may be of value for the evaluation of breast masses. (author)
A tale of two timescales: Mixing, mass generation, and phase transitions in the early universe
Dienes, Keith R.; Kost, Jeff; Thomas, Brooks
2016-02-01
Light scalar fields such as axions and string moduli can play an important role in early-universe cosmology. However, many factors can significantly impact their late-time cosmological abundances. For example, in cases where the potentials for these fields are generated dynamically—such as during cosmological mass-generating phase transitions—the duration of the time interval required for these potentials to fully develop can have significant repercussions. Likewise, in scenarios with multiple scalars, mixing amongst the fields can also give rise to an effective timescale that modifies the resulting late-time abundances. Previous studies have focused on the effects of either the first or the second timescale in isolation. In this paper, by contrast, we examine the new features that arise from the interplay between these two timescales when both mixing and time-dependent phase transitions are introduced together. First, we find that the effects of these timescales can conspire to alter not only the total late-time abundance of the system—often by many orders of magnitude—but also its distribution across the different fields. Second, we find that these effects can produce large parametric resonances which render the energy densities of the fields highly sensitive to the degree of mixing as well as the duration of the time interval over which the phase transition unfolds. Finally, we find that these effects can even give rise to a "reoverdamping" phenomenon which causes the total energy density of the system to behave in novel ways that differ from those exhibited by pure dark matter or vacuum energy. All of these features therefore give rise to new possibilities for early-universe phenomenology and cosmological evolution. They also highlight the importance of taking into account the time dependence associated with phase transitions in cosmological settings.
Dynamics of laser mass-limited foil interaction at ultra-high laser intensities
Energy Technology Data Exchange (ETDEWEB)
Yu, T. P., E-mail: tongpu@nudt.edu.cn [College of Science, National University of Defense Technology, Changsha 410073 (China); State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073 (China); Sheng, Z. M. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, Y.; Zhuo, H. B.; Ma, Y. Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Pukhov, A. [Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf (Germany)
2014-05-15
By using three-dimensional particle-in-cell simulations with synchrotron radiation damping incorporated, dynamics of ultra-intense laser driven mass-limited foils is presented. When a circularly polarized laser pulse with a peak intensity of ∼10{sup 22} W/cm{sup 2} irradiates a mass-limited nanofoil, electrons are pushed forward collectively and a strong charge separation field forms which acts as a “light sail” and accelerates the protons. When the laser wing parts overtake the foil from the foil boundaries, electrons do a betatron-like oscillation around the center proton bunch. Under some conditions, betatron-like resonance takes place, resulting in energetic circulating electrons. Finally, bright femto-second x rays are emitted in a small cone. It is also shown that the radiation damping does not alter the foil dynamics radically at considered laser intensities. The effects of the transverse foil size and laser polarization on x-ray emission and foil dynamics are also discussed.
The EDGE-CALIFA survey: validating stellar dynamical mass models with CO kinematics
Leung, Gigi Y. C.; Leaman, Ryan; van de Ven, Glenn; Lyubenova, Mariya; Zhu, Ling; Bolatto, Alberto D.; Falcón-Barroso, Jesus; Blitz, Leo; Dannerbauer, Helmut; Fisher, David B.; Levy, Rebecca C.; Sanchez, Sebastian F.; Utomo, Dyas; Vogel, Stuart; Wong, Tony; Ziegler, Bodo
2018-06-01
Deriving circular velocities of galaxies from stellar kinematics can provide an estimate of their total dynamical mass, provided a contribution from the velocity dispersion of the stars is taken into account. Molecular gas (e.g. CO), on the other hand, is a dynamically cold tracer and hence acts as an independent circular velocity estimate without needing such a correction. In this paper, we test the underlying assumptions of three commonly used dynamical models, deriving circular velocities from stellar kinematics of 54 galaxies (S0-Sd) that have observations of both stellar kinematics from the Calar Alto Legacy Integral Field Area (CALIFA) survey, and CO kinematics from the Extragalactic Database for Galaxy Evolution (EDGE) survey. We test the asymmetric drift correction (ADC) method, as well as Jeans, and Schwarzschild models. The three methods each reproduce the CO circular velocity at 1Re to within 10 per cent. All three methods show larger scatter (up to 20 per cent) in the inner regions (R < 0.4Re) that may be due to an increasingly spherical mass distribution (which is not captured by the thin disc assumption in ADC), or non-constant stellar M/L ratios (for both the JAM and Schwarzschild models). This homogeneous analysis of stellar and gaseous kinematics validates that all three models can recover Mdyn at 1Re to better than 20 per cent, but users should be mindful of scatter in the inner regions where some assumptions may break down.
STUDYING THE PHYSICAL DIVERSITY OF LATE-M DWARFS WITH DYNAMICAL MASSES
International Nuclear Information System (INIS)
Dupuy, Trent J.; Liu, Michael C.; Bowler, Brendan P.; Cushing, Michael C.; Helling, Christiane; Witte, Soeren; Hauschildt, Peter
2010-01-01
We present a systematic study of the physical properties of late-M dwarfs based on high-quality dynamical mass measurements and near-infrared (NIR) spectroscopy. We use astrometry from Keck natural and laser guide star adaptive optics imaging to determine orbits for the late-M binaries LP 349 - 25AB (M7.5+M8), LHS 1901AB (M6.5+M6.5), and Gl 569Bab (M8.5+M9). We find that LP 349 - 25AB (M tot = 0.120 +0.008 -0.007 M sun ) is a pair of young brown dwarfs for which Lyon and Tucson evolutionary models jointly predict an age of 140 ± 30 Myr, consistent with the age of the Pleiades. However, at least the primary component seems to defy the empirical Pleiades lithium depletion boundary, implying that the system is in fact older (if the parallax is correct) and that evolutionary models under-predict the component luminosities for this magnetically active binary. We find that LHS 1901AB is a pair of very low-mass stars (M tot = 0.194 +0.025 -0.021 M sun ) with evolutionary model-derived ages consistent with the old age (>6 Gyr) implied by its lack of activity. Our improved orbit for Gl 569Bab results in a higher mass for this binary (M tot = 0.140 +0.009 -0.008 M sun ) compared to previous work (0.125 ± 0.007 M sun ). We use these mass measurements along with our published results for 2MASS J2206 - 2047AB (M8+M8) to test four sets of ultracool model atmospheres currently in use. Fitting these models to our NIR integrated-light spectra provides temperature estimates warmer by ∼250 K than those derived independently from Dusty evolutionary models given the measured masses and luminosities. We propose that model atmospheres are more likely to be the source of this discrepancy, as it would be difficult to explain a uniform temperature offset over such a wide range of masses, ages, and activity levels in the context of evolutionary models. This contrasts with the conclusion of Konopacky et al. that model-predicted masses (given input T eff and L bol ) are at fault for
Image communication scheme based on dynamic visual cryptography and computer generated holography
Palevicius, Paulius; Ragulskis, Minvydas
2015-01-01
Computer generated holograms are often exploited to implement optical encryption schemes. This paper proposes the integration of dynamic visual cryptography (an optical technique based on the interplay of visual cryptography and time-averaging geometric moiré) with Gerchberg-Saxton algorithm. A stochastic moiré grating is used to embed the secret into a single cover image. The secret can be visually decoded by a naked eye if only the amplitude of harmonic oscillations corresponds to an accurately preselected value. The proposed visual image encryption scheme is based on computer generated holography, optical time-averaging moiré and principles of dynamic visual cryptography. Dynamic visual cryptography is used both for the initial encryption of the secret image and for the final decryption. Phase data of the encrypted image are computed by using Gerchberg-Saxton algorithm. The optical image is decrypted using the computationally reconstructed field of amplitudes.
Analysis of Dynamic Behavior of Multiple-Stage Planetary Gear Train Used in Wind Driven Generator
Directory of Open Access Journals (Sweden)
Jungang Wang
2014-01-01
Full Text Available A dynamic model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind driven generator to analyze the influence of revolution speed and mesh error on dynamic load sharing characteristic based on the lumped parameter theory. Dynamic equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind driven generator.
International Nuclear Information System (INIS)
Pothiya, Saravuth; Ngamroo, Issarachai; Kongprawechnon, Waree
2008-01-01
This paper presents a new optimization technique based on a multiple tabu search algorithm (MTS) to solve the dynamic economic dispatch (ED) problem with generator constraints. In the constrained dynamic ED problem, the load demand and spinning reserve capacity as well as some practical operation constraints of generators, such as ramp rate limits and prohibited operating zone are taken into consideration. The MTS algorithm introduces additional mechanisms such as initialization, adaptive searches, multiple searches, crossover and restarting process. To show its efficiency, the MTS algorithm is applied to solve constrained dynamic ED problems of power systems with 6 and 15 units. The results obtained from the MTS algorithm are compared to those achieved from the conventional approaches, such as simulated annealing (SA), genetic algorithm (GA), tabu search (TS) algorithm and particle swarm optimization (PSO). The experimental results show that the proposed MTS algorithm approaches is able to obtain higher quality solutions efficiently and with less computational time than the conventional approaches
Energy Technology Data Exchange (ETDEWEB)
Liu, Zhen, E-mail: liu-zhen@sjtu.edu.cn; Gu, Pei-Hong, E-mail: peihong.gu@sjtu.edu.cn
2017-02-15
We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.
Directory of Open Access Journals (Sweden)
Zhen Liu
2017-02-01
Full Text Available We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.
Incorporation of a Wind Generator Model into a Dynamic Power Flow Analysis
Directory of Open Access Journals (Sweden)
Angeles-Camacho C.
2011-07-01
Full Text Available Wind energy is nowadays one of the most cost-effective and practical options for electric generation from renewable resources. However, increased penetration of wind generation causes the power networks to be more depend on, and vulnerable to, the varying wind speed. Modeling is a tool which can provide valuable information about the interaction between wind farms and the power network to which they are connected. This paper develops a realistic characterization of a wind generator. The wind generator model is incorporated into an algorithm to investigate its contribution to the stability of the power network in the time domain. The tool obtained is termed dynamic power flow. The wind generator model takes on account the wind speed and the reactive power consumption by induction generators. Dynamic power flow analysis is carried-out using real wind data at 10-minute time intervals collected for one meteorological station. The generation injected at one point into the network provides active power locally and is found to reduce global power losses. However, the power supplied is time-varying and causes fluctuations in voltage magnitude and power fl ows in transmission lines.
Dong, Qingming; Sau, Amalendu
2016-06-01
Interfacial mass-transport and redistribution in the micro-scale liquid droplets are important in diverse fields of research interest. The role of the "inflow" and the "outflow" type convective eddy-pairs in the entrainment of outer solute and internal relocation are examined for different homogeneous and heterogeneous water droplet pairs appearing in a tandem arrangement. Two micro-droplets of pure (rain) water interact with an oncoming outer air stream (Re ≤ 100) contaminated by uniformly distributed SO2. By virtue of separation/attachment induced non-uniform interfacial shear-stress gradient, the well-defined inflow/outflow type pairs of recirculating eddy-based convective motion quickly develops, and the eddies effectively attract/repel the accumulated outer solute and control the physical process of mass-transport in the droplet-pair. The non-uniformly shear-driven flow interaction and bifurcation of the circulatory internal flow lead to growth of important micro-scale "secondary" eddies which suitably regroup with the adjacent "primary" one to create the sustained inflow/outflow type convective dynamics. The presently derived flow characteristics and in-depth analysis help to significantly improve our understanding of the micro-droplet based transport phenomena in a wider context. By tuning "Re" (defined in terms of the droplet diameter and the average oncoming velocity of the outer air) and gap-ratio "α," the internal convective forcing and the solute entrainment efficiency could be considerably enhanced. The quantitative estimates for mass entrainment, convective strength, and saturation characteristics for different coupled micro-droplet pairs are extensively examined here for 0.2 ≤ α ≤ 2.0 and 30 ≤ Re ≤ 100. Interestingly, for the compound droplets, with suitably tuned radius-ratio "B" (of upstream droplet with respect to downstream one) the generated "inflow" type coherent convective dynamics helped to significantly augment the centre
Dynamic model of Stirling engine crank mechanism with connected electric generator
Directory of Open Access Journals (Sweden)
Vlach R.
2009-06-01
Full Text Available This paper treats of a numerical dynamic model of Stirling engine crank mechanism. The model is included in the complex model of combined heat and power unit. The unit is composed of the Stirling engine and of attached three-phase synchronous generator. This generator should start the Stirling engine in motor mode as well. It is necessary to combine the crank shaft dynamic model and the complete thermal model of Stirling engine for simulations and analyses of engine run. Our aim is to create a dynamics model which takes into account the parameters of crankshaft, piston rods, pistons, and attached generator. For unit working, the electro-mechanical behaviour of generator is also important. That is why we experimentally verified the parameters of generator. The measured characteristics are used in a complex model of heat and power unit. Moreover, it is also possible to determine the Stirling engine torque by the help of these electro-mechanical characteristics. These values can be used e. g. for determination of optimal engine working point or for unit control.
Novel Acoustic Loading of a Mass Spectrometer: Toward Next-Generation High-Throughput MS Screening.
Sinclair, Ian; Stearns, Rick; Pringle, Steven; Wingfield, Jonathan; Datwani, Sammy; Hall, Eric; Ghislain, Luke; Majlof, Lars; Bachman, Martin
2016-02-01
High-throughput, direct measurement of substrate-to-product conversion by label-free detection, without the need for engineered substrates or secondary assays, could be considered the "holy grail" of drug discovery screening. Mass spectrometry (MS) has the potential to be part of this ultimate screening solution, but is constrained by the limitations of existing MS sample introduction modes that cannot meet the throughput requirements of high-throughput screening (HTS). Here we report data from a prototype system (Echo-MS) that uses acoustic droplet ejection (ADE) to transfer femtoliter-scale droplets in a rapid, precise, and accurate fashion directly into the MS. The acoustic source can load samples into the MS from a microtiter plate at a rate of up to three samples per second. The resulting MS signal displays a very sharp attack profile and ions are detected within 50 ms of activation of the acoustic transducer. Additionally, we show that the system is capable of generating multiply charged ion species from simple peptides and large proteins. The combination of high speed and low sample volume has significant potential within not only drug discovery, but also other areas of the industry. © 2015 Society for Laboratory Automation and Screening.
A Study of Large sin2φBs with High Mass Fourth Generation t'
International Nuclear Information System (INIS)
Ma Chien Yi
2009-01-01
The Standard Model predicts the CP violation phase φ SM Bs -M 12 ≅ (V * ts V tb ) in B s (bar) B s mixing is very small, of O(λ 2 η) ∼ -0.02, any finite value of φ Bs measured at the Tevatron would mean New Physics. Recent hints for finite sin2φ Bs have appeared from CDF and D 0 experiments at the Tevatron Run II. We consider the possibility to account for it with the 4 th generation t' quark. Considering recent direct search bounds, we set the mass to be near the unitarity bound of 600 GeV. Combining the measurement values of Δm Bs with B(B d → X s l + l - , together with typical f Bs values, we find a sizable sin2φ SM4 B s ∼ -0.3. Using a typical value of m b' = 580 GeV, we get a narrow range of values, 0.089 t'b | + → π + ν(bar)ν) and Δm D 0. Finally, we use the ZFITTER code to check the global fit deviation. (author)
Sifon, Cristobal; Battaglia, Nick; Hasselfield, Matthew; Menanteau, Felipe; Barrientos, L. Felipe; Bond, J. Richard; Crichton, Devin; Devlin, Mark J.; Dunner, Rolando; Hilton, Matt;
2016-01-01
We present galaxy velocity dispersions and dynamical mass estimates for 44 galaxy clusters selected via the Sunyaev-Zeldovich (SZ) effect by the Atacama Cosmology Telescope. Dynamical masses for 18 clusters are reported here for the first time. Using N-body simulations, we model the different observing strategies used to measure the velocity dispersions and account for systematic effects resulting from these strategies. We find that the galaxy velocity distributions may be treated as isotropic, and that an aperture correction of up to 7 per cent in the velocity dispersion is required if the spectroscopic galaxy sample is sufficiently concentrated towards the cluster centre. Accounting for the radial profile of the velocity dispersion in simulations enables consistent dynamical mass estimates regardless of the observing strategy. Cluster masses M200 are in the range (1 - 15) times 10 (sup 14) Solar Masses. Comparing with masses estimated from the SZ distortion assuming a gas pressure profile derived from X-ray observations gives a mean SZ-to-dynamical mass ratio of 1:10 plus or minus 0:13, but there is an additional 0.14 systematic uncertainty due to the unknown velocity bias; the statistical uncertainty is dominated by the scatter in the mass-velocity dispersion scaling relation. This ratio is consistent with previous determinations at these mass scales.
Generation of a Multicomponent Library of Disulfide Donor-Acceptor Architectures Using Dynamic Combinatorial Chemistry.
Drożdż, Wojciech; Kołodziejski, Michał; Markiewicz, Grzegorz; Jenczak, Anna; Stefankiewicz, Artur R
2015-07-17
We describe here the generation of new donor-acceptor disulfide architectures obtained in aqueous solution at physiological pH. The application of a dynamic combinatorial chemistry approach allowed us to generate a large number of new disulfide macrocyclic architectures together with a new type of [2]catenanes consisting of four distinct components. Up to fifteen types of structurally-distinct dynamic architectures have been generated through one-pot disulfide exchange reactions between four thiol-functionalized aqueous components. The distribution of disulfide products formed was found to be strongly dependent on the structural features of the thiol components employed. This work not only constitutes a success in the synthesis of topologically- and morphologically-complex targets, but it may also open new horizons for the use of this methodology in the construction of molecular machines.
Gautam, Bhoj R; Lee, Changyeon; Younts, Robert; Lee, Wonho; Danilov, Evgeny; Kim, Bumjoon J; Gundogdu, Kenan
2015-12-23
All-polymer solar cells exhibit rapid progress in power conversion efficiency (PCE) from 2 to 7.7% over the past few years. While this improvement is primarily attributed to efficient charge transport and balanced mobility between the carriers, not much is known about the charge generation dynamics in these systems. Here we measured exciton relaxation and charge separation dynamics using ultrafast spectroscopy in polymer/polymer blends with different molecular packing and morphology. These measurements indicate that preferential face-on configuration with intermixed nanomorphology increases the charge generation efficiency. In fact, there is a direct quantitative correlation between the free charge population in the ultrafast time scales and the external quantum efficiency, suggesting not only the transport but also charge generation is key for the design of high performance all polymer solar cells.
International Nuclear Information System (INIS)
Inan, Nagihan; Arslan, Arzu; Akansel, Gur; Anik, Yonca; Balci, N. Cem; Demirci, Ali
2008-01-01
Objective: To evaluate the value of dynamic MR imaging in the differential diagnosis of adrenal adenomas and malignant tumors, especially in cases with atypical adenomas. Materials and methods: Sixty-four masses (48 adenomas, 16 malignant tumors) were included in this prospective study. Signal loss of masses was evaluated using chemical shift MR imaging. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, with the acquisition starting simultaneously with i.v. contrast administration (0-100 s) followed by a T1-weighted FFE sequence in the late phase (5th minute). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained according to the SIs on the 0th, 25th, 50th 75th and 100th second. Also, the wash-in rate, maximum relative enhancement, time-to-peak, and wash-out of contrast at 100 s of masses in both groups were calculated. The statistical significance was determined by Mann-Whitney U test. To evaluate the diagnostic performance of the quantitative tests, receiver operating characteristic (ROC) analysis was performed. Results: Chemical shift MR imaging was able to differentiate 44 out of 48 adenomas (91.7%) from non-adenomas. The 4 adenomas (8.3%) which could not be differentiated from non-adenomas by this technique did not exhibit signal loss on out-of-phase images. With a cut-off value of 30, SI indices of adenomas had a sensitivity of 93.8%, specificity of 100% and a positive predictive value of 100%. On visual evaluation of dynamic MR imaging, early phase contrast enhancement patterns were homogeneous in 75% and punctate in 20,83% of the adenomas; while patchy in 56.25% and peripheral in 25% of the malignant tumors. On the late phase images 58.33% of the adenomas showed peripheral ring-shaped enhancement and 10.41% showed heterogeneous enhancement. All of the malignant masses showed heterogeneous
Energy Technology Data Exchange (ETDEWEB)
Pang, Yuan-Ping, E-mail: pang@mayo.edu
2014-09-26
Highlights: • Reducing atomic masses by 10-fold vastly improves sampling in MD simulations. • CLN025 folded in 4 of 10 × 0.5-μs MD simulations when masses were reduced by 10-fold. • CLN025 folded as early as 96.2 ns in 1 of the 4 simulations that captured folding. • CLN025 did not fold in 10 × 0.5-μs MD simulations when standard masses were used. • Low-mass MD simulation is a simple and generic sampling enhancement technique. - Abstract: CLN025 is one of the smallest fast-folding proteins. Until now it has not been reported that CLN025 can autonomously fold to its native conformation in a classical, all-atom, and isothermal–isobaric molecular dynamics (MD) simulation. This article reports the autonomous and repeated folding of CLN025 from a fully extended backbone conformation to its native conformation in explicit solvent in multiple 500-ns MD simulations at 277 K and 1 atm with the first folding event occurring as early as 66.1 ns. These simulations were accomplished by using AMBER forcefield derivatives with atomic masses reduced by 10-fold on Apple Mac Pros. By contrast, no folding event was observed when the simulations were repeated using the original AMBER forcefields of FF12SB and FF14SB. The results demonstrate that low-mass MD simulation is a simple and generic technique to enhance configurational sampling. This technique may propel autonomous folding of a wide range of miniature proteins in classical, all-atom, and isothermal–isobaric MD simulations performed on commodity computers—an important step forward in quantitative biology.
Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani B
Energy Technology Data Exchange (ETDEWEB)
Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Bergeron, P.; Bédard, A., E-mail: heb11@psu.edu [Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC H3C 3J7 (Canada)
2017-10-10
The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD’s mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M {sub ☉}. In this paper, we use model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then compare these results with WD interior models. Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass–radius relation (MRR) is consistent with the star’s location in the mass–radius plane. This consistency is, however, achieved only if we assume a “thin” outer hydrogen layer, with q {sub H} = M {sub H}/ M {sub WD} ≃ 10{sup −10}. We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of the expectation from canonical stellar-evolution theory of “thick” H layers with q {sub H} ≃ 10{sup −4}. The cooling age of 40 Eri B is ∼122 Myr, and its total age is ∼1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observations is excellent in all cases.
International Nuclear Information System (INIS)
El-Badry, Kareem; Quataert, Eliot; Wetzel, Andrew R.; Hopkins, Philip F.; Geha, Marla; Kereš, Dusan; Chan, T. K.; Faucher-Giguère, Claude-André
2017-01-01
In low-mass galaxies, stellar feedback can drive gas outflows that generate non-equilibrium fluctuations in the gravitational potential. Using cosmological zoom-in baryonic simulations from the Feedback in Realistic Environments project, we investigate how these fluctuations affect stellar kinematics and the reliability of Jeans dynamical modeling in low-mass galaxies. We find that stellar velocity dispersion and anisotropy profiles fluctuate significantly over the course of galaxies’ starburst cycles. We therefore predict an observable correlation between star formation rate and stellar kinematics: dwarf galaxies with higher recent star formation rates should have systemically higher stellar velocity dispersions. This prediction provides an observational test of the role of stellar feedback in regulating both stellar and dark-matter densities in dwarf galaxies. We find that Jeans modeling, which treats galaxies as virialized systems in dynamical equilibrium, overestimates a galaxy’s dynamical mass during periods of post-starburst gas outflow and underestimates it during periods of net inflow. Short-timescale potential fluctuations lead to typical errors of ∼20% in dynamical mass estimates, even if full three-dimensional stellar kinematics—including the orbital anisotropy—are known exactly. When orbital anisotropy is not known a priori, typical mass errors arising from non-equilibrium fluctuations in the potential are larger than those arising from the mass-anisotropy degeneracy. However, Jeans modeling alone cannot reliably constrain the orbital anisotropy, and problematically, it often favors anisotropy models that do not reflect the true profile. If galaxies completely lose their gas and cease forming stars, fluctuations in the potential subside, and Jeans modeling becomes much more reliable.
Energy Technology Data Exchange (ETDEWEB)
El-Badry, Kareem; Quataert, Eliot [Department of Astronomy, University of California, Berkeley, CA (United States); Wetzel, Andrew R.; Hopkins, Philip F. [TAPIR, California Institute of Technology, Pasadena, CA (United States); Geha, Marla [Department of Astronomy, Yale University, New Haven, CT (United States); Kereš, Dusan; Chan, T. K. [Department of Physics, Center for Astrophysics and Space Sciences, University of California at San Diego, La Jolla (United States); Faucher-Giguère, Claude-André, E-mail: kelbadry@berkeley.edu [Department of Physics and Astronomy and CIERA, Northwestern University, Evanston, IL (United States)
2017-02-01
In low-mass galaxies, stellar feedback can drive gas outflows that generate non-equilibrium fluctuations in the gravitational potential. Using cosmological zoom-in baryonic simulations from the Feedback in Realistic Environments project, we investigate how these fluctuations affect stellar kinematics and the reliability of Jeans dynamical modeling in low-mass galaxies. We find that stellar velocity dispersion and anisotropy profiles fluctuate significantly over the course of galaxies’ starburst cycles. We therefore predict an observable correlation between star formation rate and stellar kinematics: dwarf galaxies with higher recent star formation rates should have systemically higher stellar velocity dispersions. This prediction provides an observational test of the role of stellar feedback in regulating both stellar and dark-matter densities in dwarf galaxies. We find that Jeans modeling, which treats galaxies as virialized systems in dynamical equilibrium, overestimates a galaxy’s dynamical mass during periods of post-starburst gas outflow and underestimates it during periods of net inflow. Short-timescale potential fluctuations lead to typical errors of ∼20% in dynamical mass estimates, even if full three-dimensional stellar kinematics—including the orbital anisotropy—are known exactly. When orbital anisotropy is not known a priori, typical mass errors arising from non-equilibrium fluctuations in the potential are larger than those arising from the mass-anisotropy degeneracy. However, Jeans modeling alone cannot reliably constrain the orbital anisotropy, and problematically, it often favors anisotropy models that do not reflect the true profile. If galaxies completely lose their gas and cease forming stars, fluctuations in the potential subside, and Jeans modeling becomes much more reliable.
On the dynamics of tapered vibro-impacting cantilever with tip mass
Energy Technology Data Exchange (ETDEWEB)
Gandhi, P. S.; Vyas, Vishal [Suman Mashruwala Advanced Microengineering Laboratory, Dept. of Mechanical Engineering, Indian Institute of Technology - Bombay, Mumai (India)
2017-01-15
This paper explores nonlinear dynamic behavior of vibro-impacting tapered cantilever with tip mass with regard to frequency response analysis. A typical frequency response curve of vibro-impacting beams displays well-known resonance frequency shift along with a hysteric jump and drop phenomena. We did a comprehensive parametric analysis capturing the effects of taper, tip-mass, stop location, and gap on the non-smooth frequency response. Analysis is presented in a non-dimensional form useful for other similar cases. Simulation results are further validated with corresponding experimental results for a few cases. Illustrative comparison of simulation results for varying parameters brings out several interesting aspects of variation in the nonlinear behavior.
Charge solitons and their dynamical mass in one-dimensional arrays of Josephson junctions
International Nuclear Information System (INIS)
Homfeld, Jens; Protopopov, Ivan; Rachel, Stephan; Shnirman, Alexander
2011-01-01
We investigate charge transport in one-dimensional arrays of Josephson junctions. In the interesting regime of ''small charge solitons'' (polarons), ΛE J >E C >E J , where Λ is the (electrostatic) screening length, the charge dynamics are strongly influenced by the polaronic effects (i.e., by dressing of a Cooper pair by charge dipoles). In particular, the soliton's mass in this regime scales approximately as E J -2 . We employ two theoretical techniques: the many-body tight-binding approach and the mean-field approach, and the results of the two approaches agree in the regime of ''small charge solitons.'' Renormalization of the soliton's mass could be observed; for example, as enhancement of the persistent current in a ring-shaped array.
Screening masses in quenched (2+1)d Yang-Mills theory: Universality from dynamics?
International Nuclear Information System (INIS)
Frigori, Rafael B.
2010-01-01
We compute the spectrum of gluonic screening-masses in the 0 ++ channel of quenched 3d Yang-Mills theory near the phase-transition. Our finite-temperature lattice simulations are performed at scaling region, using state-of-art techniques for thermalization and spectroscopy, which allows for thorough data extrapolations to thermodynamic limit. Ratios among mass-excitations with the same quantum numbers on the gauge theory, 2d Ising and λφ 4 models are compared, resulting in a nice agreement with predictions from universality. In addition, a gauge-to-scalar mapping, previously employed to fit QCD Green's functions at deep IR, is verified to dynamically describe these universal spectroscopic patterns.
Bootstrap calculation of the dynamical quark mass in QCD4 at finite temperature
International Nuclear Information System (INIS)
Cabo, A.; Kalashnikov, O.K.; Veliev, E.Kh.
1988-01-01
Nonperturbative calculations of the dynamical quark mass m(T) are given in QCD 4 , based on the bootstrap solution of the Schwinger-Dyson equation for the quark Green function at finite temperatures. A closed nonlinear equation is obtained for m(T) whose solution is found under some simplifying assumptions. We used a particular approximation for the effective charge and the nonperturbative expressions of the gluon magnetic and electric masses. The singular behavior of m(T) is established and its parameters are determined numerically. The singularity found is shown to correctly reproduce the chiral phase transition and the temperature limits obtained for m(T) are qualitatively correct. The complete phase diagram of QCD 4 in the (μ,T) plane is briefly discussed. (orig.)
Dynamical and luminosity evolution of active galactic nuclei - Models with a mass spectrum
International Nuclear Information System (INIS)
Murphy, B.W.; Cohn, H.N.; Durisen, R.H.
1991-01-01
A multimass energy-space Fokker-Planck code is used to follow the dynamical and luminosity evolution of an AGN model that consists of a dense stellar system surrounding a massive black hole. It is found that stellar evolution and tidal disruption are the predominant mass-loss mechanisms for low-density nuclei, whereas physical collisions dominate in high-density nuclei. For initial central densities greater than 10 million solar masses/cu pc the core of the stellar system contacts due to the removal of kinetic energy by collisions, whereas for densities less than this the core of the stellar system expands due to heating that results from the settling of a small population of stars into orbits tightly bound to the black hole. These mechanisms produce differing power-law slopes in the resulting stellar density cusp surrounding the black hole, -7/4 and -1/2 for low- and high-density nuclei, respectively. 60 refs
Dynamic stability and failure modes of slopes in discontinuous rock mass
International Nuclear Information System (INIS)
Shimizu, Yasuhiro; Aydan, O.; Ichikawa, Yasuaki; Kawamoto, Toshikazu.
1988-01-01
The stability of rock slopes during earthquakes are of great concern in rock engineering works such as highway, dam, and nuclear power station constructions. As rock mass in nature is usually discontinuous, the stability of rock slopes will be geverned by the spatial distribution of discontinuities in relation with the geometry of slope and their mechanical properties rather than the rock element. The authors have carried out some model tests on discontinuous rock slopes using three different model tests techniques in order to investigate the dynamic behaviour and failure modes of the slopes in discontinuous rock mass. This paper describes the findings and observations made on model rock slopes with various discontinuity patterns and slope geometry. In addition some stability criterions are developed and the calculated results are compared with those of experiments. (author)
Multi-valley effective mass theory for device-level modeling of open quantum dynamics
Jacobson, N. Tobias; Baczewski, Andrew D.; Frees, Adam; Gamble, John King; Montano, Ines; Moussa, Jonathan E.; Muller, Richard P.; Nielsen, Erik
2015-03-01
Simple models for semiconductor-based quantum information processors can provide useful qualitative descriptions of device behavior. However, as experimental implementations have matured, more specific guidance from theory has become necessary, particularly in the form of quantitatively reliable yet computationally efficient modeling. Besides modeling static device properties, improved characterization of noisy gate operations requires a more sophisticated description of device dynamics. Making use of recent developments in multi-valley effective mass theory, we discuss device-level simulations of the open system quantum dynamics of a qubit interacting with phonons and other noise sources. Sandia is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.
Terrestrial Planet Formation: Dynamical Shake-up and the Low Mass of Mars
Bromley, Benjamin C.; Kenyon, Scott J.
2017-05-01
We consider a dynamical shake-up model to explain the low mass of Mars and the lack of planets in the asteroid belt. In our scenario, a secular resonance with Jupiter sweeps through the inner solar system as the solar nebula depletes, pitting resonant excitation against collisional damping in the Sun’s protoplanetary disk. We report the outcome of extensive numerical calculations of planet formation from planetesimals in the terrestrial zone, with and without dynamical shake-up. If the Sun’s gas disk within the terrestrial zone depletes in roughly a million years, then the sweeping resonance inhibits planet formation in the asteroid belt and substantially limits the size of Mars. This phenomenon likely occurs around other stars with long-period massive planets, suggesting that asteroid belt analogs are common.
Optimality with feedback control in relativistic dynamics of a mass point. Part 1
International Nuclear Information System (INIS)
Blaquiere, A.; Pauchard, M.; Tahri-Yousfi, N.; Wickers, D.
1984-01-01
This article is an account of part of a research task currently in progress; it deals with relativistic dynamics of a mass-point from the point of view of the theory of optimal feedback control. In the first part, the theoretical frame is presented with an application to the case of special Relativity. This application shows that the way followed in this article is a natural one for approaching Wave mechanics, and that it closely parallels the way along which Louis de Broglie introduced Wave mechanics [fr
Establishment and analysis of coupled dynamic model for dual-mass silicon micro-gyroscope
Wang, Zhanghui; Qiu, Anping; Shi, Qin; Zhang, Taoyuan
2017-12-01
This paper presents a coupled dynamic model for a dual-mass silicon micro-gyroscope (DMSG). It can quantitatively analyze the influence of left-right stiffness difference on the natural frequencies, modal matrix and modal coupling coefficient of the DMSG. The analytic results are verified by using the finite element method (FEM) simulation. The model shows that with the left-right stiffness difference of 1%, the modal coupling coefficient is 12% in the driving direction and 31% in the sensing direction. It also shows that in order to achieve good separation, the stiffness of base beam should be small enough in both the driving and sensing direction.
Kazerooni, Anahita Fathi; Malek, Mahrooz; Haghighatkhah, Hamidreza; Parviz, Sara; Nabil, Mahnaz; Torbati, Leila; Assili, Sanam; Saligheh Rad, Hamidreza; Gity, Masoumeh
2017-02-01
To identify the best dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) descriptive parameters in predicting malignancy of complex ovarian masses, and develop an optimal decision tree for accurate classification of benign and malignant complex ovarian masses. Preoperative DCE-MR images of 55 sonographically indeterminate ovarian masses (27 benign and 28 malignant) were analyzed prospectively. Four descriptive parameters of the dynamic curve, namely, time-to-peak (TTP), wash-in-rate (WIR), relative signal intensity (SI rel ), and the initial area under the curve (IAUC 60 ) were calculated on the normalized curves of specified regions-of-interest (ROIs). A two-tailed Student's t-test and two automated classifiers, linear discriminant analysis (LDA) and support vector machines (SVMs), were used to compare the performance of the mentioned parameters individually and in combination with each other. TTP (P = 6.15E-8) and WIR (P = 5.65E-5) parameters induced the highest sensitivity (89% for LDA, and 97% for SVM) and specificity (93% for LDA, and 100% for SVM), respectively. Regarding the high sensitivity of TTP and high specificity of WIR and through their combination, an accurate and simple decision-tree classifier was designed using the line equation obtained by LDA classification model. The proposed classifier achieved an accuracy of 89% and area under the ROC curve of 93%. In this study an accurate decision-tree classifier based on a combination of TTP and WIR parameters was proposed, which provides a clinically flexible framework to aid radiologists/clinicians to reach a conclusive preoperative diagnosis and patient-specific therapy plan for distinguishing malignant from benign complex ovarian masses. 2 J. Magn. Reson. Imaging 2017;45:418-427. © 2016 International Society for Magnetic Resonance in Medicine.
Energy Technology Data Exchange (ETDEWEB)
Tanabe, R.; Yasuda, K.; Yokoyama, R. (Tokyo Metropolitan Univ., Tokyo (Japan))
1992-05-20
To supply cheap, high-reliable and a planty of the electricity is an important task of the electric supply system because the requirement for the electricity is rapidly increased in Japan. In order to solve this problem, the authors of the paper are developing a most suitable practical method based on algorithm, according to which the generation expansion planning is divided into two problems: the optimal generation mix and the optimal generation construction process and the two problems are solved respectively. But there are some bad points in the method, for example, there are only approximative practical restriction of the capacity of single machine and the existing electric supply etc., because the optimal generation mix is determined on the basis of non-linear planning. So, in the present paper, the electric supply support system is practically constructed while proposing an unified generation expansion planning based on the dynamic programming that is possible to consider these restrictions strictly and the usefullness of the method is inspected. 12 refs., 7 figs., 5 tabs.
Real-time dynamic analysis for complete loop of direct steam generation solar trough collector
International Nuclear Information System (INIS)
Guo, Su; Liu, Deyou; Chu, Yinghao; Chen, Xingying; Shen, Bingbing; Xu, Chang; Zhou, Ling; Wang, Pei
2016-01-01
Highlights: • A nonlinear distribution parameter dynamic model has been developed. • Real-time local heat transfer coefficient and friction coefficient are adopted. • The dynamic behavior of the solar trough collector loop are simulated. • High-frequency chattering of outlet fluid flow are analyzed and modeled. • Irradiance disturbance at subcooled water region generates larger influence. - Abstract: Direct steam generation is a potential approach to further reduce the levelized electricity cost of solar trough. Dynamic modeling of the collector loop is essential for operation and control of direct steam generation solar trough. However, the dynamic behavior of fluid based on direct steam generation is complex because of the two-phase flow in the pipeline. In this work, a nonlinear distribution parameter model has been developed to model the dynamic behaviors of direct steam generation parabolic trough collector loops under either full or partial solar irradiance disturbance. Compared with available dynamic model, the proposed model possesses two advantages: (1) real-time local values of heat transfer coefficient and friction resistance coefficient, and (2) considering of the complete loop of collectors, including subcooled water region, two-phase flow region and superheated steam region. The proposed model has shown superior performance, particularly in case of sensitivity study of fluid parameters when the pipe is partially shaded. The proposed model has been validated using experimental data from Solar Thermal Energy Laboratory of University of New South Wales, with an outlet fluid temperature relative error of only 1.91%. The validation results show that: (1) The proposed model successfully outperforms two reference models in predicting the behavior of direct steam generation solar trough. (2) The model theoretically predicts that, during solar irradiance disturbance, the discontinuities of fluid physical property parameters and the moving back and
Xu, Yu; Wang, Hong; Nussinov, Ruth; Ma, Buyong
2013-01-01
We constructed and simulated a ‘minimal proteome’ model using Langevin dynamics. It contains 206 essential protein types which were compiled from the literature. For comparison, we generated six proteomes with randomized concentrations. We found that the net charges and molecular weights of the proteins in the minimal genome are not random. The net charge of a protein decreases linearly with molecular weight, with small proteins being mostly positively charged and large proteins negatively charged. The protein copy numbers in the minimal genome have the tendency to maximize the number of protein-protein interactions in the network. Negatively charged proteins which tend to have larger sizes can provide large collision cross-section allowing them to interact with other proteins; on the other hand, the smaller positively charged proteins could have higher diffusion speed and are more likely to collide with other proteins. Proteomes with random charge/mass populations form less stable clusters than those with experimental protein copy numbers. Our study suggests that ‘proper’ populations of negatively and positively charged proteins are important for maintaining a protein-protein interaction network in a proteome. It is interesting to note that the minimal genome model based on the charge and mass of E. Coli may have a larger protein-protein interaction network than that based on the lower organism M. pneumoniae. PMID:23420643
Extended-Term Dynamic Simulations with High Penetrations of Photovoltaic Generation.
Energy Technology Data Exchange (ETDEWEB)
Concepcion, Ricky James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Donnelly, Matt [Montana Tech., Butte, MT (United States); Sanchez-Gasca, Juan [GE Energy, Schenectady, NY (United States)
2016-01-01
The uncontrolled intermittent availability of renewable energy sources makes integration of such devices into today's grid a challenge. Thus, it is imperative that dynamic simulation tools used to analyze power system performance are able to support systems with high amounts of photovoltaic (PV) generation. Additionally, simulation durations expanding beyond minutes into hours must be supported. This report aims to identify the path forward for dynamic simulation tools to accom- modate these needs by characterizing the properties of power systems (with high PV penetration), analyzing how these properties affect dynamic simulation software, and offering solutions for po- tential problems. We present a study of fixed time step, explicit numerical integration schemes that may be more suitable for these goals, based on identified requirements for simulating high PV penetration systems. We also present the alternative of variable time step integration. To help determine the characteristics of systems with high PV generation, we performed small signal sta- bility studies and time domain simulations of two representative systems. Along with feedback from stakeholders and vendors, we identify the current gaps in power system modeling including fast and slow dynamics and propose a new simulation framework to improve our ability to model and simulate longer-term dynamics.
DEFF Research Database (Denmark)
Trinhammer, Ole
PiMinus invariant mass in B decays. We give a controversial prediction of the relative neutron to proton mass difference 0.138 % as originating in period doublings of certain parametric states. The group space dynamics communicates with real space via the exterior derivative which projects out quark and gluon...
Propagation dynamics and X-pulse formation in phase-mismatched second-harmonic generation
International Nuclear Information System (INIS)
Valiulis, G.; Jukna, V.; Jedrkiewicz, O.; Clerici, M.; Rubino, E.; DiTrapani, P.
2011-01-01
This paper concerns the theoretical, numerical, and experimental study of the second-harmonic-generation (SHG) process under conditions of phase and group-velocity mismatch and aims to demonstrate the dimensionality transition of the SHG process caused by the change of the fundamental wave diameter. We show that SHG from a narrow fundamental beam leads to the spontaneous self-phase-matching process with, in addition, the appearance of angular dispersion for the off-axis frequency components generated. The angular dispersion sustains the formation of the short X pulse in the second harmonic (SH) and is recognized as three-dimensional (3D) dynamics. On the contrary, the large-diameter fundamental beam reduces the number of the degrees of freedom, does not allow the generation of the angular dispersion, and maintains the so-called one-dimensional (1D) SHG dynamics, where the self-phase-matching appears just for axial components and is accompanied by the shrinking of the SH temporal bandwidth, and sustains a long SH pulse formation. The transition from long SH pulse generation typical of the 1D dynamics to the short 3D X pulse is illustrated numerically and experimentally by changing the conditions from the self-defocusing to the self-focusing regime by simply tuning the phase mismatch. The numerical and experimental verification of the analytical results are also presented.
International Nuclear Information System (INIS)
Kaplan, E.
1985-01-01
Krypton-81m supplied from a generator by continuous elution with air is used with a gamma-camera computer system to produce a sequence of images from multiple breaths, which reconstructed the time-activity images of the breathing human lung. Functional images are produced by subsequent derivation to show specific variables of the dynamic sequences. The dynamic, quantitative, and regional aspects of the respiratory cycle are thus made available in a single study. The need for the delivery of a constant ratio of /sub 81m/Kr to air is required to accurately produce these various studies
VHS-tape system for general purpose computer. For next generation mass storage system
International Nuclear Information System (INIS)
Ukai, K.; Takano, M.; Shinohara, M.; Niki, K.; Suzuki, Y.; Hamada, T.; Ogawa, M.
1994-07-01
Mass storage is one of the key technology of next generation computer system. A huge amount of data is produced on a field of particle and nuclear physics. These data are raw data of experiments, analysis data, Monte Carlo simulations data, etc. We search a storage device for these data at the point of view of capacity, price, size, transfer speed, etc. We have selected a VHS-tape (12.7 mm-tape, helical scan) from many storage devices. Characteristics of the VHS-tape are as follows; capacity of 14.5 GB, size of 460 cm 3 , price of 1,000 yen (S-VHS tape for video use), and 1.996 MB/sec transfer speed at a sustained mode. Last year, we succeeded to operate the VHS-tape system on a workstation as a I/O device with read/write speed of 1.5 MB/sec. We have tested a VHS-tape system by connecting to the channel of the general purpose computer (Fujitsu M-780/10S) in our institute. We obtained a read and write speeds of 1.07 MB/sec and 1.72 MB/sec by FORTRAN test programs, respectively. Read speeds of an open reel tape and a 3480 type cassete tape by the same test programs are 1.13 MB/sec and 2.54 MB/sec, respectively. Speeds of write operation are 1.09 MB/sec and 2.54 MB/sec for the open reel and 3480 cassete tape, respectively. A start motion of the VHS-tape for read/write operations needs about 60 seconds. (author)
Spatiotemporal Dynamics of Ammonia-Oxidizing Thaumarchaeota in Distinct Arctic Water Masses
Directory of Open Access Journals (Sweden)
Oliver Müller
2018-01-01
Full Text Available One of the most abundant archaeal groups on Earth is the Thaumarchaeota. They are recognized as major contributors to marine ammonia oxidation, a crucial step in the biogeochemical cycling of nitrogen. Their universal success is attributed to a high genomic flexibility and niche adaptability. Based on differences in the gene coding for ammonia monooxygenase subunit A (amoA, two different ecotypes with distinct distribution patterns in the water column have been identified. We used high-throughput sequencing of 16S rRNA genes combined with archaeal amoA functional gene clone libraries to investigate which environmental factors are driving the distribution of Thaumarchaeota ecotypes in the Atlantic gateway to the Arctic Ocean through an annual cycle in 2014. We observed the characteristic vertical pattern of Thaumarchaeota abundance with high values in the mesopelagic (>200 m water throughout the entire year, but also in the epipelagic (<200 m water during the dark winter months (January, March and November. The Thaumarchaeota community was dominated by three OTUs which on average comprised 76% ± 11 and varied in relative abundance according to water mass characteristics and not to depth or ammonium concentration, as suggested in previous studies. The ratios of the abundance of the different OTU types were similar to that of the functional amoA water cluster types. Together, this suggests a strong selection of ecotypes within different water masses, supporting the general idea of water mass characteristics as an important factor in defining microbial community structure. If indeed, as suggested in this study, Thaumarchaeota population dynamics are controlled by a set of factors, described here as water mass characteristics and not just depth alone, then changes in water mass flow will inevitably affect the distribution of the different ecotypes.
Characterization of breast masses by dynamic enhanced MR imaging. A logistic regression analysis
International Nuclear Information System (INIS)
Ikeda, O.; Morishita, S.; Kido, T.; Kitajima, M.; Yamashita, Y.; Takahashi, M.; Okamura, K.; Fukuda, S.
1999-01-01
Purpose: To identify features useful for differentiation between malignant and benign breast neoplasms using multivariate analysis of findings by MR imaging. Material and Methods: In a retrospective analysis, 61 patients with 64 breast masses underwent MR imaging and the time-signal intensity curves for precontrast dynamic postcontrast images were quantitatively analyzed. Statistical analysis was performed using a logistic regression model, which was prospectively tested in another 34 patients with suspected breast masses. Results: Univariate analysis revealed that the reliable indicators for malignancy were first the appearance of the tumor border, followed by the washout ratio, internal architecture after contrast enhancement, and peak time. The factors significantly associated with malignancy were irregular tumor border, followed by washout ratio, internal architecture, and peak time. For differentiation between benignity and malignancy, the maximum cut-off point was to be found between 0.47 and 0.51. In a prospective application of this model, 91% of the lesions were accurately discriminated as benign or malignant lesions. Conclusion: Combination of contrast-enhanced dynamic and postcontrast-enhanced MR imaging provided accurate data for the diagnosis of malignant neoplasms of the breast. The model had an accuracy of 91% (sensitivity 90%, specificity 93%). (orig.)
International Nuclear Information System (INIS)
Dermisek, Radovan
2004-01-01
We show that both small mixing in the quark sector and large mixing in the lepton sector can be obtained from a simple assumption of universality of Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading order. We discuss conditions under which bilarge mixing in the lepton sector is achieved with a minimal amount of fine-tuning requirements for possible models. From knowledge of the solar and atmospheric mixing angles we determine the allowed values of sin θ 13 . If embedded into grand unified theories, the third generation Yukawa coupling unification is a generic feature while masses of the first two generations of charged fermions depend on small perturbations. In the neutrino sector, the heavier two neutrinos are model dependent, while the mass of the lightest neutrino in this approach does not depend on perturbations in the leading order. The right-handed neutrino mass scale can be identified with the GUT scale in which case the mass of the lightest neutrino is given as (m top 2 /M GUT )sin 2 θ 23 sin 2 θ 12 in the limit sin θ 13 ≅0. Discussing symmetries we make a connection with hierarchical models and show that the basis independent characteristic of this scenario is a strong dominance of the third generation right-handed neutrino, M 1 ,M 2 -4 M 3 , M 3 =M GUT
International Nuclear Information System (INIS)
Hary, Nicolas; Rious, Vincent; Saguan, Marcelo
2016-01-01
Following liberalization reforms, the ability of power markets to provide satisfactory incentives for capacity investments has become a major concern. In particular, current energy markets can exhibit a phenomenon of investment cycles, which generate phases of under and over-capacity, and hence additional costs and risks for generation adequacy. To cope with these issues, new mechanisms, called capacity remuneration mechanisms (CRM), have been (or will be) implemented. This paper assesses the dynamic effects of two CRMs, the capacity market and the strategic reserve mechanism, and studies to what extent they can reduce the investment cycles. Generation costs and shortage costs of both mechanisms are also compared to conclude on their effectivity and economic efficiency. A simulation model, based on system dynamics, is developed to study the functioning of both CRMs and the related investment decisions. The results highlight the benefits of deploying CRMs to solve the adequacy issue: shortages are strongly reduced compared to an energy-only market. Besides, the capacity market appears to be more beneficial, since it experiences fewer shortages and generation costs are lower. These comparisons can be used by policy makers (in particular in Europe, where these two CRMs are mainly debated) to determine which CRM to adopt. - Highlights: •A study of the dynamic effects of CRMs on generation investments is provided. •Capacity market and strategic reserve mechanism are compared. •Both CRMs reduce the cyclical tendencies prone to appear in energy-only market. •The capacity market experiences fewer shortages and generation costs are lower.
Directory of Open Access Journals (Sweden)
Benedetta Turriziani
2014-04-01
Full Text Available With the advent of the “-omics” era, biological research has shifted from functionally analyzing single proteins to understanding how entire protein networks connect and adapt to environmental cues. Frequently, pathological processes are initiated by a malfunctioning protein network rather than a single protein. It is therefore crucial to investigate the regulation of proteins in the context of a pathway first and signaling network second. In this study, we demonstrate that a quantitative interaction proteomic approach, combining immunoprecipitation, in-solution digestion and label-free quantification mass spectrometry, provides data of high accuracy and depth. This protocol is applicable, both to tagged, exogenous and untagged, endogenous proteins. Furthermore, it is fast, reliable and, due to a label-free quantitation approach, allows the comparison of multiple conditions. We further show that we are able to generate data in a medium throughput fashion and that we can quantify dynamic interaction changes in signaling pathways in response to mitogenic stimuli, making our approach a suitable method to generate data for system biology approaches.
International Nuclear Information System (INIS)
Cichy, K.
2012-03-01
We study the 'spectral projector' method for the computation of the chiral condensate and the topological susceptibility, using N f =2+1+1 dynamical flavors of maximally twisted mass Wilson fermions. In particular, we perform a study of the quark mass dependence of the chiral condensate Σ and topological susceptibility χ top in the range 270 MeV π top in the quenched approximation where we match the lattice spacing to the N f =2+1+1 dynamical simulations. Using the Kaon, η and η' meson masses computed on the N f =2+1+1 ensembles, we then perform a preliminary test of the Witten-Veneziano relation.
International Nuclear Information System (INIS)
Katrasnik, Tomaz; Medica, Vladimir; Trenc, Ferdinand
2005-01-01
Reliability of electric supply systems is among the most required necessities of modern society. Turbocharged diesel engine driven alternating current generating sets are often used to prevent electric black outs and/or as prime electric energy suppliers. It is well known that turbocharged diesel engines suffer from an inadequate response to a sudden load increase, this being a consequence of the nature of the energy exchange between the engine and the turbocharger. The dynamic response of turbocharged diesel engines could be improved by electric assisting systems, either by direct energy supply with an integrated starter-generator-booster (ISG) mounted on the engine flywheel, or by an indirect energy supply with an electrically assisted turbocharger. An experimentally verified zero dimensional computer simulation method was used for the analysis of both types of electrical assistance. The paper offers an analysis of the interaction between a turbocharged diesel engine and different electric assisting systems, as well as the requirements for the supporting electric motors that could improve the dynamic response of a diesel engine while driving an AC generating set. When performance class compliance is a concern, it is evident that an integrated starter-generator-booster outperforms an electrically assisted turbocharger for the investigated generating set. However, the electric energy consumption and frequency recovery times are smaller when an electrically assisted turbocharger is applied
International Nuclear Information System (INIS)
Higuet, J.
2010-10-01
High harmonic generation is a well known phenomenon explained by a three step model: because of the high intensity field generated by an ultrashort laser pulse, an atom or a molecule can be tunnel ionized. The ejected electron is then accelerated by the intense electric field, and eventually can recombine on its parent ion, leading to the emission of a XUV photon. Because of the generating process in itself, this light source is a promising candidate to probe the electronic structure of atoms and molecules, with an atto-second/sub-nanometer potential resolution (1 as=10 -18 s). In this work, we have studied the sensitivity of the emitted light (in terms of amplitude, but also phase and polarization) towards the electronic structure of the generating medium. We have first worked on atomic medium, then on molecules (N 2 , CO 2 , O 2 ). Comparing the experimental results with numerical simulations shows the necessity to model finely the generation process and to go beyond commonly used approximations. We have also shown the possibility to perform high harmonic spectroscopy in order to measure dynamics of complex molecules, such as Nitrogen Dioxide (NO 2 ). This technic has obtained complementary results compared to classical spectroscopy and has revealed dynamics of the electronic wave packet along a conical intersection. In this experiment, we have adapted conventional optical spectroscopy technic to the XUV spectral area, which significantly improved the signal over noise ratio. (author)
Directory of Open Access Journals (Sweden)
E. D. Schmitter
2010-02-01
Full Text Available Recent observations endorse earlier measurements of time varying electric and magnetic fields generated by tornadoes and dust devils. These signals may provide a means for early warning but together with a proper modeling approach can also provide insight into geometry and dynamics of the vortices. Our model calculations show the existence of pressure resonances characterized as acoustic duct modes with well defined frequencies. These resonances not only generate infrasound but also modulate the charge density and the velocity field and in this way lead to electric and magnetic field oscillations in the 0.5–20-Hz range that can be monitored from a distance of several kilometers.
CERN LEP2 constraint on 4D QED having a dynamically generated spatial dimension
International Nuclear Information System (INIS)
Cho, G.-C.; Izumi, Etsuko; Sugamoto, Akio
2002-01-01
We study 4D QED in which one spatial dimension is dynamically generated from the 3D action, following the mechanism proposed by Arkani-Hamed, Cohen, and Georgi. In this model, the generated fourth dimension is discretized by an interval parameter a. We examine the phenomenological constraint on the parameter a coming from collider experiments on the QED process e + e - →γγ. It is found that the CERN e + e - collider LEP2 experiments give the constraint of 1/a > or approx. 461 GeV. The expected bound on the same parameter a at a future e + e - linear collider is briefly discussed
A new strategy for transient stability using augmented generator control and local dynamic braking
Energy Technology Data Exchange (ETDEWEB)
Dorsey, J; Jiang, H; Habetler, T [Georgia Inst. of Tech., Atlanta, GA (United States); Qu, Z [University of Central Florida, Orlando, FL (United States)
1994-12-31
A decentralized automatic control strategy for significantly improving the transient stability of a large power system is introduced. The strategy combines local dynamic braking and a straightforward augmentation of the existing turbine / governor control system that uses only local feedback. The brake resistor, which employs thick film, metal oxide technology, has no inductance and is of very low resistance, allowing its use during fault to show a generator`s acceleration. Simulation results using the 39 Bus New England system show that the strategy dramatically increases the global stability of a power system. (author) 15 refs., 7 figs., 1 tab.
The effect of gas double-dynamic on mass distribution in solid-state fermentation.
Chen, Hong-Zhang; Zhao, Zhi-Min; Li, Hong-Qiang
2014-05-10
The mass distribution regularity in substrate of solid-state fermentation (SSF) has rarely been reported due to the heterogeneity of solid medium and the lack of suitable instrument and method, which limited the comprehensive analysis and enhancement of the SSF performance. In this work, the distributions of water, biomass, and fermentation product in different medium depths of SSF were determined using near-infrared spectroscopy (NIRS) and the developed models. Based on the mass distribution regularity, the effects of gas double-dynamic on heat transfer, microbial growth and metabolism, and product distribution gradient were systematically investigated. Results indicated that the maximum temperature of substrate and the maximum carbon dioxide evolution rate (CER) were 39.5°C and 2.48mg/(hg) under static aeration solid-state fermentation (SASSF) and 33.9°C and 5.38mg/(hg) under gas double-dynamic solid-state fermentation (GDSSF), respectively, with the environmental temperature for fermentation of 30±1°C. The fermentation production (cellulase activity) ratios of the upper, middle, and lower levels were 1:0.90:0.78 at seventh day under SASSF and 1:0.95:0.89 at fifth day under GDSSF. Therefore, combined with NIRS analysis, gas double-dynamic could effectively strengthen the solid-state fermentation performance due to the enhancement of heat transfer, the stimulation of microbial metabolism and the increase of the homogeneity of fermentation products. Copyright © 2014 Elsevier Inc. All rights reserved.
M*/L gradients driven by IMF variation: large impact on dynamical stellar mass estimates
Bernardi, M.; Sheth, R. K.; Dominguez-Sanchez, H.; Fischer, J.-L.; Chae, K.-H.; Huertas-Company, M.; Shankar, F.
2018-06-01
Within a galaxy the stellar mass-to-light ratio ϒ* is not constant. Recent studies of spatially resolved kinematics of nearby early-type galaxies suggest that allowing for a variable initial mass function (IMF) returns significantly larger ϒ* gradients than if the IMF is held fixed. We show that ignoring such IMF-driven ϒ* gradients can have dramatic effect on dynamical (M_*^dyn), though stellar population (M_*^SP) based estimates of early-type galaxy stellar masses are also affected. This is because M_*^dyn is usually calibrated using the velocity dispersion measured in the central regions (e.g. Re/8) where stars are expected to dominate the mass (i.e. the dark matter fraction is small). On the other hand, M_*^SP is often computed from larger apertures (e.g. using a mean ϒ* estimated from colours). If ϒ* is greater in the central regions, then ignoring the gradient can overestimate M_*^dyn by as much as a factor of two for the most massive galaxies. Large ϒ*-gradients have four main consequences: First, M_*^dyn cannot be estimated independently of stellar population synthesis models. Secondly, if there is a lower limit to ϒ* and gradients are unknown, then requiring M_*^dyn=M_*^SP constrains them. Thirdly, if gradients are stronger in more massive galaxies, then accounting for this reduces the slope of the correlation between M_*^dyn/M_*^SP of a galaxy with its velocity dispersion. In particular, IMF-driven gradients bring M_*^dyn and M_*^SP into agreement, not by shifting M_*^SP upwards by invoking constant bottom-heavy IMFs, as advocated by a number of recent studies, but by revising M_*^dyn estimates in the literature downwards. Fourthly, accounting for ϒ* gradients changes the high-mass slope of the stellar mass function φ (M_*^dyn), and reduces the associated stellar mass density. These conclusions potentially impact estimates of the need for feedback and adiabatic contraction, so our results highlight the importance of measuring ϒ* gradients in
Directory of Open Access Journals (Sweden)
V. A. Minaev
2016-12-01
Full Text Available The article examines a mathematical model of destructive information-psychological influence (IPI dynamics on mass consciousness. It is shown that a model taking into account three main processes - informational influence on mass consciousness of interpersonal communication, mass media, effect of influence forgetting - has solution in the form of a generalized logistic curve. Given a statistical distribution over time of society individuals, who share ideas of IPI, which qualitatively confirms a formal decision model, presented in the form of nonlinear differential equations describing of innovation diffusion. Investigated special cases of the model, which in all cases confirmed existence of asymptotic stationary solutions. To use the model in practice to analyze and predict characteristics of IPI on society, and, ultimately, to control this effect, estimation of its parameters based on statistical data. Accented that the development of the model is essential in modern conditions complicate the problem of ensuring cyber security of the state, society and every individual member of society, including considering the development of social networks.
International Nuclear Information System (INIS)
Sondericker, J.; Wolf, L.J.
1991-02-01
The new design of the RHIC dipole magnets incorporate helium containment bellows having a convolution diameter of only 7.63 inches. The present bellows are 12.80 inches in diameter. The smaller bellows present a substantially reduced pressure area which can be expected to reduce proportionately the end force on the cold mass during a quench. But, the objection was raised that the smaller bellows would present greater obstruction to the helium flow during a quench thereby producing higher pressure differentials. This analysis was undertaken to address these assertions by predicting the dynamic displacements of the cold mass using the latest test data on the stiffness of the IMC posts, pressure-time histories acquired from the recent full cell tests of RHIC magnets, and the dimensions of the new expansion joints. The analysis treated the cold mass as an elastic body having a saggittal curvature. The technique of normal mode expansion of a lumped-parameter system was used to obtain the results and conclusions reported herein
Sizing of the Series Dynamic Breaking Resistor in a Doubly Fed Induction Generator Wind Turbine
DEFF Research Database (Denmark)
Soliman, Hammam; Wang, Huai; Zhou, Dao
2014-01-01
This paper investigates the effect of Series Dynamic Breaking Resistor (SDBR) sizing on a Doubly Fed Induction Generator (DFIG) based wind power conversion system. The boundary of the SDBR value is firstly derived by taking into account the controllability of the rotor side converter and the maxi......This paper investigates the effect of Series Dynamic Breaking Resistor (SDBR) sizing on a Doubly Fed Induction Generator (DFIG) based wind power conversion system. The boundary of the SDBR value is firstly derived by taking into account the controllability of the rotor side converter...... and the maximum allowable voltage of the stator. Then the impact of the SDBR value on the rotor current, stator voltage, DC-link voltage, reactive power capability and introduced power loss during voltage sag operation is evaluated by simulation. The presented study enables a trade-off sizing of the SDBR among...
Dynamic performance of power generation systems for off-shore oil and gas platforms
DEFF Research Database (Denmark)
Pierobon, Leonardo; Breuhaus, Peter; Haglind, Fredrik
2014-01-01
%) arises on the prediction of the rotational speed of the high pressure shaft, while the largest deviation (average relative error ~20%) occurs in the evaluation of the pressure at the outlet of the low pressure turbine. As waste heat recovery units (e.g. organic Rankine cycles) are likely...... to be implemented in future off-shore platforms, the proposed model may serve in the design phase for a preliminary assessment of the dynamic response of the power generation system and to evaluate if requirements such as minimum and maximum frequency during transient operation and the recovery time are satisfied......On off-shore oil and gas platforms two or more gas turbines typically support the electrical demand on site by operating as a stand-alone (island) power system. As reliability and availability are major concerns during operation, the dynamic performance of the power generation system becomes...
Co-Design of Event Generator and Dynamic Output Feedback Controller for LTI Systems
Directory of Open Access Journals (Sweden)
Dan Ma
2015-01-01
Full Text Available This paper presents a co-design method of the event generator and the dynamic output feedback controller for a linear time-invariant (LIT system. The event-triggered condition on the sensor-to-controller and the controller-to-actuator depends on the plant output and the controller output, respectively. A sufficient condition on the existence of the event generator and the dynamic output feedback controller is proposed and the co-design problem can be converted into the feasibility of linear matrix inequalities (LMIs. The LTI system is asymptotically stable under the proposed event-triggered controller and also reduces the computing resources with respect to the time-triggered one. In the end, a numerical example is given to illustrate the effectiveness of the proposed approach.
Leyva, R.; Artillan, P.; Cabal, C.; Estibals, B.; Alonso, C.
2011-04-01
The article studies the dynamic performance of a family of maximum power point tracking circuits used for photovoltaic generation. It revisits the sinusoidal extremum seeking control (ESC) technique which can be considered as a particular subgroup of the Perturb and Observe algorithms. The sinusoidal ESC technique consists of adding a small sinusoidal disturbance to the input and processing the perturbed output to drive the operating point at its maximum. The output processing involves a synchronous multiplication and a filtering stage. The filter instance determines the dynamic performance of the MPPT based on sinusoidal ESC principle. The approach uses the well-known root-locus method to give insight about damping degree and settlement time of maximum-seeking waveforms. This article shows the transient waveforms in three different filter instances to illustrate the approach. Finally, an experimental prototype corroborates the dynamic analysis.
Directory of Open Access Journals (Sweden)
Aline Aparecida Buriola
2017-12-01
Full Text Available A study to comprehend the requests, concerns, and questions of professionals about the assistance dynamic of a psychiatric emergency service. We conducted a case study, using the Fourth Generation assessment method, with 15 participants. We collected data using documental analysis, semi-structured interview and observation and, we used the constant comparative method for analysis. Therefore, two thematic axes arose: a Comprehending the assistance dynamic of the Psychiatric emergency service and, b The disarticulation of the psychosocial attention network as a barrier to satisfaction with the assistance in the psychiatric emergency. We considered that the assistance dynamic in the Psychiatric Emergency extrapolated the simple, unique character of stabilizing patients with acute mental disorders, once it directs the user’s flow to the adequate treatment in the psychosocial attention network.
Review of single particle dynamics for third generation light sources through frequency map analysis
Directory of Open Access Journals (Sweden)
L. Nadolski
2003-11-01
Full Text Available Frequency map analysis [J. Laskar, Icarus 88, 266 (1990] is used here to analyze the transverse dynamics of four third generation synchrotron light sources: the ALS, the ESRF, the SOLEIL project, and Super-ACO. Time variations of the betatron tunes give additional information for the global dynamics of the beam. The main resonances are revealed; a one-to-one correspondence between the configuration space and the frequency space can be performed. We stress that the frequency maps, and therefore the dynamics optimization, are highly sensitive to sextupolar strengths and vary in a large amount from one machine to another. The frequency maps can thus be used to characterize the different machines.
Czech Academy of Sciences Publication Activity Database
Licari, G.; Cwiklik, Lukasz; Jungwirth, Pavel; Vauthey, E.
2017-01-01
Roč. 33, č. 14 (2017), s. 3373-3383 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388955 ; RVO:61388963 Keywords : sum-frequency generation * excited-state dynamics * air-water-interface * density-functional theory Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.833, year: 2016
Czech Academy of Sciences Publication Activity Database
Licari, G.; Cwiklik, Lukasz; Jungwirth, Pavel; Vauthey, E.
2017-01-01
Roč. 33, č. 14 (2017), s. 3373-3383 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388955 ; RVO:61388963 Keywords : sum -frequency generation * excited-state dynamics * air-water-interface * density-functional theory Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.833, year: 2016
Does fetal smoke exposure affect childhood bone mass? The Generation R Study
D.H.M. Heppe (Denise); M.C. Medina-Gomez (Carolina); A. Hofman (Albert); F. Rivadeneira Ramirez (Fernando); V.W.V. Jaddoe (Vincent)
2015-01-01
textabstractSummary: We assessed the intrauterine influence of maternal smoking on childhood bone mass by comparing parental prenatal and postnatal smoking habits. We observed higher bone mass in children exposed to maternal smoking, explained by higher body weight. Maternal smoking or related
Dynamic Model for Hydro-Turbine Generator Units Based on a Database Method for Guide Bearings
Directory of Open Access Journals (Sweden)
Yong Xu
2013-01-01
Full Text Available A suitable dynamic model of rotor system is of great significance not only for supplying knowledge of the fault mechanism, but also for assisting in machine health monitoring research. Many techniques have been developed for properly modeling the radial vibration of large hydro-turbine generator units. However, an applicable dynamic model has not yet been reported in literature due to the complexity of the boundary conditions and exciting forces. In this paper, a finite element (FE rotor dynamic model of radial vibration taking account of operating conditions is proposed. A brief and practical database method is employed to model the guide bearing. Taking advantage of the method, rotating speed and bearing clearance can be considered in the model. A novel algorithm, which can take account of both transient and steady-state analysis, is proposed to solve the model. Dynamic response for rotor model of 125 MW hydro-turbine generator units in Gezhouba Power Station is simulated. Field data from Optimal Maintenance Information System for Hydro power plants (HOMIS are analyzed compared with the simulation. Results illustrate the application value of the model in providing knowledge of the fault mechanism and in failure diagnosis.
International Nuclear Information System (INIS)
Antoniadis, I A; Venetsanos, D T; Papaspyridis, F G
2013-01-01
Dielectric elastomer based generators (DEGs) offer some unique properties over energy generators based on other materials. These properties include high energy density, high efficiency over a broad range of frequencies, low compliance, the ability to produce high strain, large area, low cost films with no toxic materials and wide range environmental tolerance. As further shown in this paper, DEG materials can also exhibit a non-linear dynamic behavior, enhancing broad-band energy transfer. More specifically, dielectric elastomer (DE) energy generating synergetic structures (DIESYS) are considered as dynamic energy absorbers. Two elementary characteristic DIESYS design concepts are examined, leading to a typical antagonistic configuration for in-plane oscillations and a typical synagonistic configuration for out-of-plane oscillations. Originally, all the DE elements of the structure are assumed to be always in tension during all the phases of the harvesting cycle, conforming to the traditional concept of operation of DE structures. As shown in this paper, the traditional always-in-tension concept results in a linear dynamic system response, despite the fact that the implemented (DE) parts are considered to have been made of a non-linear (hyperelastic) material. In contrast, the proposed loose-part concept ensures the appearance of a non-linear broad-band system response, enhancing energy transfer from the environmental source. (paper)
Khambhati, Ankit N.; Davis, Kathryn A.; Oommen, Brian S.; Chen, Stephanie H.; Lucas, Timothy H.; Litt, Brian; Bassett, Danielle S.
2015-01-01
The epileptic network is characterized by pathologic, seizure-generating ‘foci’ embedded in a web of structural and functional connections. Clinically, seizure foci are considered optimal targets for surgery. However, poor surgical outcome suggests a complex relationship between foci and the surrounding network that drives seizure dynamics. We developed a novel technique to objectively track seizure states from dynamic functional networks constructed from intracranial recordings. Each dynamical state captures unique patterns of network connections that indicate synchronized and desynchronized hubs of neural populations. Our approach suggests that seizures are generated when synchronous relationships near foci work in tandem with rapidly changing desynchronous relationships from the surrounding epileptic network. As seizures progress, topographical and geometrical changes in network connectivity strengthen and tighten synchronous connectivity near foci—a mechanism that may aid seizure termination. Collectively, our observations implicate distributed cortical structures in seizure generation, propagation and termination, and may have practical significance in determining which circuits to modulate with implantable devices. PMID:26680762
Improved dynamic-programming-based algorithms for segmentation of masses in mammograms
International Nuclear Information System (INIS)
Dominguez, Alfonso Rojas; Nandi, Asoke K.
2007-01-01
In this paper, two new boundary tracing algorithms for segmentation of breast masses are presented. These new algorithms are based on the dynamic programming-based boundary tracing (DPBT) algorithm proposed in Timp and Karssemeijer, [S. Timp and N. Karssemeijer, Med. Phys. 31, 958-971 (2004)] The DPBT algorithm contains two main steps: (1) construction of a local cost function, and (2) application of dynamic programming to the selection of the optimal boundary based on the local cost function. The validity of some assumptions used in the design of the DPBT algorithm is tested in this paper using a set of 349 mammographic images. Based on the results of the tests, modifications to the computation of the local cost function have been designed and have resulted in the Improved-DPBT (IDPBT) algorithm. A procedure for the dynamic selection of the strength of the components of the local cost function is presented that makes these parameters independent of the image dataset. Incorporation of this dynamic selection procedure has produced another new algorithm which we have called ID 2 PBT. Methods for the determination of some other parameters of the DPBT algorithm that were not covered in the original paper are presented as well. The merits of the new IDPBT and ID 2 PBT algorithms are demonstrated experimentally by comparison against the DPBT algorithm. The segmentation results are evaluated with base on the area overlap measure and other segmentation metrics. Both of the new algorithms outperform the original DPBT; the improvements in the algorithms performance are more noticeable around the values of the segmentation metrics corresponding to the highest segmentation accuracy, i.e., the new algorithms produce more optimally segmented regions, rather than a pronounced increase in the average quality of all the segmented regions
International Nuclear Information System (INIS)
Janecky, D.R.
1988-01-01
A computational modeling code (EQPSreverse arrowS) has been developed to examine sulfur isotopic distribution pathways coupled with calculations of chemical mass transfer pathways. A post processor approach to EQ6 calculations was chosen so that a variety of isotopic pathways could be examined for each reaction pathway. Two types of major bounding conditions were implemented: (1) equilibrium isotopic exchange between sulfate and sulfide species or exchange only accompanying chemical reduction and oxidation events, and (2) existence or lack of isotopic exchange between solution species and precipitated minerals, parallel to the open and closed chemical system formulations of chemical mass transfer modeling codes. All of the chemical data necessary to explicitly calculate isotopic distribution pathways is generated by most mass transfer modeling codes and can be input to the EQPS code. Routines are built in to directly handle EQ6 tabular files. Chemical reaction models of seafloor hydrothermal vent processes and accompanying sulfur isotopic distribution pathways illustrate the capabilities of coupling EQPSreverse arrowS with EQ6 calculations, including the extent of differences that can exist due to the isotopic bounding condition assumptions described above. 11 refs., 2 figs
Effects of dynamic matrix remodelling on en masse migration of fibroblasts on collagen matrices.
Ozcelikkale, Altug; Dutton, J Craig; Grinnell, Frederick; Han, Bumsoo
2017-10-01
Fibroblast migration plays a key role during various physiological and pathological processes. Although migration of individual fibroblasts has been well studied, migration in vivo often involves simultaneous locomotion of fibroblasts sited in close proximity, so-called ' en masse migration', during which intensive cell-cell interactions occur. This study aims to understand the effects of matrix mechanical environments on the cell-matrix and cell-cell interactions during en masse migration of fibroblasts on collagen matrices. Specifically, we hypothesized that a group of migrating cells can significantly deform the matrix, whose mechanical microenvironment dramatically changes compared with the undeformed state, and the alteration of the matrix microenvironment reciprocally affects cell migration. This hypothesis was tested by time-resolved measurements of cell and extracellular matrix movement during en masse migration on collagen hydrogels with varying concentrations. The results illustrated that a group of cells generates significant spatio-temporal deformation of the matrix before and during the migration. Cells on soft collagen hydrogels migrate along tortuous paths, but, as the matrix stiffness increases, cell migration patterns become aligned with each other and show coordinated migration paths. As cells migrate, the matrix is locally compressed, resulting in a locally stiffened and dense matrix across the collagen concentration range studied. © 2017 The Author(s).
Dynamics of Russian business culture values in the reflection of mass media
Directory of Open Access Journals (Sweden)
E. A. Sverdlikova
2016-01-01
Full Text Available The article analyses practices of “Traditions and values of Russian business culture” course teaching at Lomonosov Moscow State University’s Faculty of Sociology. The experience allows drawing methodological and theoretical conclusions on the values of business culture which underlie models of the modern business behavior. The first part of the publication concerns analysis of tradition of studying Russian culture values, in the paradigm of which the Russian business culture exists. According to the findings, traditions are enrooted in the Orthodoxy and are determined by patrimonial memories and contradictions of the Russian people’s character, ideals and spiritual framework. A system of Russian business values is developed based on the traditions as well as literary heritage, biographies of famous Russian and Soviet economists and set of rules of ethics code of the pre-revolutionary Russian business class. The main elements of the system include the following values: faith, family, commitment to business, patriotism, natural ingenuity, ability to set and solve atask of extra complexity, original forms of labor organization, and prevalence of moral motivation forms over material ones. The second part of the article deals with succession of the above-mentioned values in the modern Russian business environment. The content analysis is applied to examine the continuity. The object of the research is the text corpus of the Russian business press. The findings of the research show dynamics of the Russian mass media attention to the business culture values for the period from 2010 to 2014. The mass media interest to the issue coverage has been on the constant rise: from 37,2% of the aggregate amount of information on the Russian business in 2012 to 39,8% in 2014. There have also been examined dynamics of mass media attention to certain business culture values. The mass media assignedtop priority in 2012, 2013 and 2014 to the following values
Cienfuegos, R.; Duarte, L.; Hernandez, E.
2008-12-01
Charasteristic frequencies of gravity waves generated by wind and propagating towards the coast are usually comprised between 0.05Hz and 1Hz. Nevertheless, lower frequecy waves, in the range of 0.001Hz and 0.05Hz, have been observed in the nearshore zone. Those long waves, termed as infragravity waves, are generated by complex nonlinear mechanisms affecting the propagation of irregular waves up to the coast. The groupiness of an incident random wave field may be responsible for producing a slow modulation of the mean water surface thus generating bound long waves travelling at the group speed. Similarly, a quasi- periodic oscillation of the break-point location, will be accompained by a slow modulation of set-up/set-down in the surf zone and generation and release of long waves. If the primary structure of the carrying incident gravity waves is destroyed (e.g. by breaking), forced long waves can be freely released and even reflected at the coast. Infragravity waves can affect port operation through resonating conditions, or strongly affect sediment transport and beach morphodynamics. In the present study we investigate infragravity wave generation mechanisms both, from experiments and numerical computations. Measurements were conducted at the 70-meter long wave tank, located at the Instituto Nacional de Hidraulica (Chile), prepared with a beach of very mild slope of 1/80 in order to produce large surf zone extensions. A random JONSWAP type wave field (h0=0.52m, fp=0.25Hz, Hmo=0.17m) was generated by a piston wave-maker and measurements of the free surface displacements were performed all over its length at high spatial resolution (0.2m to 1m). Velocity profiles were also measured at four verticals inside the surf zone using an ADV. Correlation maps of wave group envelopes and infragravity waves are computed in order to identify long wave generation and dynamics in the experimental set-up. It appears that both mechanisms (groupiness and break-point oscillation) are
International Nuclear Information System (INIS)
Gao Jinwei; Bao Qianqian; Wan Rengang; Cui Cuili; Wu Jinhui
2011-01-01
We study a cold atomic sample coherently driven into the five-level triple-Λ configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to 92% can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-Λ system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.
Dynamic analysis of combined photovoltaic source and synchronous generator connected to power grid
Mahabal, Divya
In the world of expanding economy and technology, the energy demand is likely to increase even with the global efforts of saving and increasing energy efficiency. Higher oil prices, effects of greenhouse gases, and concerns over other environmental impacts gave way to Distributed Generation (DG). With adequate awareness and support, DG's can meet these rising energy demands at lower prices compared to conventional methods. Extensive research is taking place in different areas like fuel cells, photovoltaic cells, wind turbines, and gas turbines. DG's when connected to a grid increase the overall efficiency of the power grid. It is believed that three-fifth of the world's electricity would account for renewable energy by middle of 21st century. This thesis presents the dynamic analysis of a grid connected photovoltaic (PV) system and synchronous generator. A grid is considered as an infinite bus. The photovol-taic system and synchronous generator act as small scale distributed energy resources. The output of the photovoltaic system depends on the light intensity, temperature, and irradiance levels of sun. The maximum power point tracking and DC/AC converter are also modeled for the photovoltaic system. The PV system is connected to the grid through DC/AC system. Different combinations of PV and synchronous generator are modeled with the grid to study the dynamics of the proposed system. The dynamics of the test system is analyzed by subjecting the system to several disturbances under various conditions. All modules are individually modeled and con-nected using MATLAB/Simulink software package. Results from the study show that, as the penetration of renewable energy sources like PV increases into the power system, the dynamics of the system becomes faster. When considering cases such as load switching, PV cannot deliver more power as the performance of PV depends on environmental conditions. Synchronous generator in power system can produce the required amount of
International Nuclear Information System (INIS)
Dyson, Brian; Chang, N.-B.
2005-01-01
Both planning and design of municipal solid waste management systems require accurate prediction of solid waste generation. Yet achieving the anticipated prediction accuracy with regard to the generation trends facing many fast-growing regions is quite challenging. The lack of complete historical records of solid waste quantity and quality due to insufficient budget and unavailable management capacity has resulted in a situation that makes the long-term system planning and/or short-term expansion programs intangible. To effectively handle these problems based on limited data samples, a new analytical approach capable of addressing socioeconomic and environmental situations must be developed and applied for fulfilling the prediction analysis of solid waste generation with reasonable accuracy. This study presents a new approach - system dynamics modeling - for the prediction of solid waste generation in a fast-growing urban area based on a set of limited samples. To address the impact on sustainable development city wide, the practical implementation was assessed by a case study in the city of San Antonio, Texas (USA). This area is becoming one of the fastest-growing regions in North America due to the economic impact of the North American Free Trade Agreement (NAFTA). The analysis presents various trends of solid waste generation associated with five different solid waste generation models using a system dynamics simulation tool - Stella[reg]. Research findings clearly indicate that such a new forecasting approach may cover a variety of possible causative models and track inevitable uncertainties down when traditional statistical least-squares regression methods are unable to handle such issues
Recovery after mass extinction: evolutionary assembly in large-scale biosphere dynamics.
Solé, Ricard V; Montoya, José M; Erwin, Douglas H
2002-01-01
Biotic recoveries following mass extinctions are characterized by a process in which whole ecologies are reconstructed from low-diversity systems, often characterized by opportunistic groups. The recovery process provides an unexpected window to ecosystem dynamics. In many aspects, recovery is very similar to ecological succession, but important differences are also apparently linked to the innovative patterns of niche construction observed in the fossil record. In this paper, we analyse the similarities and differences between ecological succession and evolutionary recovery to provide a preliminary ecological theory of recoveries. A simple evolutionary model with three trophic levels is presented, and its properties (closely resembling those observed in the fossil record) are compared with characteristic patterns of ecological response to disturbances in continuous models of three-level ecosystems. PMID:12079530
Mass transfer dynamics of ammonia in high rate biomethanation of poultry litter leachate.
Gangagni Rao, A; Gandu, Bharath; Swamy, Y V
2012-04-01
In the present study possibility of coupling biofilter to arrest ammonia (NH(3)) emission to the atmosphere from the integrated UASB and stripper (UASB+ST) system treating poultry litter leachate was studied. UASB+ST with biofilter (UASB+ST+BF) exhibited removal efficiency (RE) of NH(3) in the range of 98-99% (below 28 ppmV (parts per million by volume)) with low cost agricultural residue as a bedding material. Mass transfer dynamics of TAN in the system revealed that TAN loss to atmosphere was below 1% in UASB+ST+BF where as it was in the range of 70-90% in UASB+ST. Cost estimates revealed that financial implications due to the addition of biofilter were below 10% of total capital cost. TAN retained in the bedding material of biofilter could also be utilized as soil conditioner upon saturation. Copyright © 2012 Elsevier Ltd. All rights reserved.
DEFF Research Database (Denmark)
Larsson, Hilde Kristina
the velocity and pressure distributions in a fluid. CFD also enables the modelling of several fluids simultaneously, e.g. gas bubbles in a liquid, as well as the presence of turbulence and dissolved chemicals in a fluid, and many other phenomena. This makes CFD an appreciated tool for studying flow structures......, mixing, and other mass transfer phenomena in chemical and biochemical reactor systems. In this project, four selected case studies are investigated in order to explore the capabilities of CFD. The selected cases are a 1 ml stirred microbioreactor, an 8 ml magnetically stirred reactor, a Rushton impeller...... and an ion-exchange reaction are also modelled and compared to experimental data. The thesis includes a comprehensive overview of the fundamentals behind a CFD software, as well as a more detailed review of the fluid dynamic phenomena investigated in this project. The momentum and continuity equations...
DEFF Research Database (Denmark)
Morales Rodriguez, Ricardo; Meyer, Anne S.; Gernaey, Krist
of cellulose, co-fermentation of sugars and downstream processes for purification and recovery of most value-added products. The dynamic model involves both the mass and energy balances coupled with constitutive dynamic equations to assess the process yield and energy efficiency of different bioethanol...
Shean, D. E.; Arendt, A. A.; Osmanoglu, B.; Montesano, P.
2017-12-01
High Mountain Asia (HMA) constitutes the largest glacierized region outside of the Earth's polar regions. Although available observations are limited, long-term records indicate sustained regional glacier mass loss since 1850, with increased loss in recent decades. Recent satellite data (e.g., GRACE, ICESat-1) show spatially variable glacier mass balance, with significant mass loss in the Himalaya and Hindu Kush and slight mass gain in the Karakoram. We generated 4000 high-resolution digital elevation models (DEMs) from sub-meter commercial stereo imagery (DigitalGlobe WorldView/GeoEye) acquired over glaciers in High-mountain Asia from 2002-present (mostly 2013-present). We produced a regional 8-m DEM mosaic for 2015 and estimated 15-year geodetic mass balance for 40000 glaciers larger than 0.1 km2. We are combining with other regional DEM sources to systematically document the spatiotemporal evolution of glacier mass balance for the entire HMA region. We also generated monthly to interannual DEM and velocity time series for high-priority sites distributed across the region, with >15-20 DEMs available for some locations from 2010-present. These records document glacier dynamics, seasonal snow accumulation/redistribution, and processes that affect glacier mass balance (e.g., ice-cliff retreat, debris cover evolution). These efforts will provide basin-scale assessments of snow/ice melt runoff contributions for model cal/val and downstream water resources applications. We will continue processing all archived and newly available commercial stereo imagery for HMA, and will release all DEMs through the HiMAT DAAC.
Maternal first-trimester diet and childhood bone mass: the Generation R Study.
Heppe, Denise H M; Medina-Gomez, Carolina; Hofman, Albert; Franco, Oscar H; Rivadeneira, Fernando; Jaddoe, Vincent W V
2013-07-01
Maternal diet during pregnancy has been suggested to influence bone health in later life. We assessed the association of maternal first-trimester dietary intake during pregnancy with childhood bone mass. In a prospective cohort study in 2819 mothers and their children, we measured first-trimester daily energy, protein, fat, carbohydrate, calcium, phosphorus, and magnesium intakes by using a food-frequency questionnaire and homocysteine, folate, and vitamin B-12 concentrations in venous blood. We measured childhood total body bone mass by using dual-energy X-ray absorptiometry at the median age of 6.0 y. Higher first-trimester maternal protein, calcium, and phosphorus intakes and vitamin B-12 concentrations were associated with higher childhood bone mass, whereas carbohydrate intake and homocysteine concentrations were associated with lower childhood bone mass (all P-trend childhood bone mass. In the fully adjusted regression model that included all dietary factors significantly associated with childhood bone mass, maternal phosphorus intake and homocysteine concentrations most-strongly predicted childhood bone mineral content (BMC) [β = 2.8 (95% CI: 1.1, 4.5) and β = -1.8 (95% CI: -3.6, 0.1) g per SD increase, respectively], whereas maternal protein intake and vitamin B-12 concentrations most strongly predicted BMC adjusted for bone area [β = 2.1 (95% CI: 0.7, 3.5) and β = 1.8 (95% CI: 0.4, 3.2) g per SD increase, respectively]. Maternal first-trimester dietary factors are associated with childhood bone mass, suggesting that fetal nutritional exposures may permanently influence bone development.
Energy Technology Data Exchange (ETDEWEB)
Borg, Matthew K., E-mail: matthew.borg@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Lockerby, Duncan A., E-mail: duncan.lockerby@warwick.ac.uk [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Reese, Jason M., E-mail: jason.reese@ed.ac.uk [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)
2014-02-21
The emergence of new applications of molecular dynamics (MD) simulation calls for the development of mass-statting procedures that insert or delete particles on-the-fly. In this paper we present a new mass-stat which we term FADE, because it gradually “fades-in” (inserts) or “fades-out” (deletes) molecules over a short relaxation period within a MD simulation. FADE applies a time-weighted relaxation to the intermolecular pair forces between the inserting/deleting molecule and any neighbouring molecules. The weighting function we propose in this paper is a piece-wise polynomial that can be described entirely by two parameters: the relaxation time scale and the order of the polynomial. FADE inherently conserves overall system momentum independent of the form of the weighting function. We demonstrate various simulations of insertions of atomic argon, polyatomic TIP4P water, polymer strands, and C{sub 60} Buckminsterfullerene molecules. We propose FADE parameters and a maximum density variation per insertion-instance that restricts spurious potential energy changes entering the system within desired tolerances. We also demonstrate in this paper that FADE compares very well to an existing insertion algorithm called USHER, in terms of accuracy, insertion rate (in dense fluids), and computational efficiency. The USHER algorithm is applicable to monatomic and water molecules only, but we demonstrate that FADE can be generally applied to various forms and sizes of molecules, such as polymeric molecules of long aspect ratio, and spherical carbon fullerenes with hollow interiors.
International Nuclear Information System (INIS)
Borg, Matthew K.; Lockerby, Duncan A.; Reese, Jason M.
2014-01-01
The emergence of new applications of molecular dynamics (MD) simulation calls for the development of mass-statting procedures that insert or delete particles on-the-fly. In this paper we present a new mass-stat which we term FADE, because it gradually “fades-in” (inserts) or “fades-out” (deletes) molecules over a short relaxation period within a MD simulation. FADE applies a time-weighted relaxation to the intermolecular pair forces between the inserting/deleting molecule and any neighbouring molecules. The weighting function we propose in this paper is a piece-wise polynomial that can be described entirely by two parameters: the relaxation time scale and the order of the polynomial. FADE inherently conserves overall system momentum independent of the form of the weighting function. We demonstrate various simulations of insertions of atomic argon, polyatomic TIP4P water, polymer strands, and C 60 Buckminsterfullerene molecules. We propose FADE parameters and a maximum density variation per insertion-instance that restricts spurious potential energy changes entering the system within desired tolerances. We also demonstrate in this paper that FADE compares very well to an existing insertion algorithm called USHER, in terms of accuracy, insertion rate (in dense fluids), and computational efficiency. The USHER algorithm is applicable to monatomic and water molecules only, but we demonstrate that FADE can be generally applied to various forms and sizes of molecules, such as polymeric molecules of long aspect ratio, and spherical carbon fullerenes with hollow interiors
Quest for the dynamical origin of mass. An LHC perspective from Sakata, Nambu and Maskawa
International Nuclear Information System (INIS)
Yamawaki, Koichi
2009-01-01
I review the dynamical symmetry breaking (DSB) approach to the Origin of Mass, which is traced back to the original (2008 Nobel Prize) work of Nambu based on the BCS analogue of superconductor where mass of nucleon (then elementary particle) arises due to Cooper paring and pions are provided as massless Nambu-Goldstone (NG) bosons, being composite as in Fermi-Yang/Sakata model. In this talk I will focus on the modern version of DSB or composite Higgs models: Walking/Conformal Technicolor, Hidden Local Symmetry (HLS) or Moose, and Top Quark Condensate, with the their extra dimension versions closely related with HLS. Particular emphasis will be placed on the large anomalous dimension and conformal symmetry at the conformal fixed points, developed along the line of the pioneering work of Maskawa and Nakajima. Due to (approximate) conformal symmetry these models do have composite Higgs particle ('Techni-dilaton', 'Top-sigma', etc.). Weakly coupled composite gauge boson is realized at 'Vector Manifestation' formulated at conformal fixed point, which may be applied to the composite W/Z boson models. They will be tested in the upcoming LHC experiments. (author)
Study of water mass transfer dynamics in frescoes by dielectric spectroscopy
International Nuclear Information System (INIS)
Olmi, R.; Riminesi, C.
2008-01-01
The knowledge of moisture content (M C) is essential for determining the state of preservation of various types of hand-work: from building materials such as bricks and concrete, to objects of artistic value, in particular frescoes and mural paintings. In all above, moisture is the primary source of damages, as it affects the durability of porous materials. Dielectric properties of porous materials are strongly affected by the presence of water, suggesting dielectric spectroscopy as a suitable non-invasive diagnostic technique. The development of a quantitative relationship between M C and permittivity requires to investigate the dynamics of water mass transfer in porous media, and to determine its effect on the dielectric properties. In this paper a coupled mass transfer/dielectric problem is introduced and solved numerically, based on a finite element model. Results are compared to experimental dielectric measurements performed on plaster samples by the open coaxial method. The application of the dielectric technique to frescoes monitoring is proposed, showing the results obtained is an on-site study.
Study on Dynamic Disaster in Steeply Deep Rock Mass Condition in Urumchi Coalfield
Directory of Open Access Journals (Sweden)
Xing-Ping Lai
2015-01-01
Full Text Available The possible mining seismicity (MS and its prediction are important for safety and recovery optimization of mining in steep-heavy-thick rock mass condition. The stress-lever-rotation-effect (SLRE model of fault-like mobilization was proposed preliminarily. Some innovation monitoring technique approaches for mining seismicity assessment were successfully fulfilled at Wudong Mine of Urumchi Coalfield, China. The characteristics on acoustic-seismic-wave index indicated the spatial-temporal-strength and stress redistribution of steeply deeper-heavy thick coal and rock masses. Applications in field investigations showed that the innovation monitoring (in time and space of these instruments could provide important information about the performance of mining disturbed structures (heading and steep pillar during caving of competent overlying roof strata. The prediction and evaluation for mining seismicity were applicable and valid. Operating practice showed that mining efficiency was raised and conspicuous economic benefit was obtained. This approach provides essential data for assessing mining seismicity, coal burst, dynamic hazard prevention, and deep mining potential.
Fluid Dynamics And Mass Transfer In Two-Fluid Taylor-Couette Flow
International Nuclear Information System (INIS)
Baier, G.; Graham, M.D.
1998-01-01
The Taylor-Couette instability of a single liquid phase can be used to enhance mass transfer processes such as filtration and membrane separations. We consider here the possibility of using this instability to enhance interphase transport in a two-fluid systems, with a view toward improved liquid-liquid extractions for biotechnology applications. We investigate the centrifugal instability of a pair of radially stratified immiscible liquids in the annular gap between concentric, corotating cylinders: two-fluid Taylor-Couette flow. Experiments show that a two-layer flow with a well-defined interface and Taylor vortices in each phase can be obtained. The experimental results are in good agreement with predictions of inviscid arguments based on a two-phase extension of Rayleigh's criterion, as well as with detailed linear stability calculations. For a given geometry, the most stable configuration occurs for fluids of roughly (exactly in the inviscid limit) equal dynamic viscosities. A number of preliminary mass transfer experiments have also been performed, in the presence of axial counterflow. The onset of Taylor vortices coincides with a clear decrease in the extent of axial dispersion and an increase in the rate of interphase transport, thus suggesting that this flow geometry may provide an effective means for countercurrent chromatographic separations
Dynamics and mass transport of solutal convection in a closed porous media system
Wen, Baole; Akhbari, Daria; Hesse, Marc
2016-11-01
Most of the recent studies of CO2 sequestration are performed in open systems where the constant partial pressure of CO2 in the vapor phase results in a time-invariant saturated concentration of CO2 in the brine (Cs). However, in some closed natural CO2 reservoirs, e.g., Bravo Dome in New Mexico, the continuous dissolution of CO2 leads to a pressure drop in the gas that is accompanied by a reduction of Cs and thereby affects the dynamics and mass transport of convection in the brine. In this talk, I discuss the characteristics of convective CO2 dissolution in a closed system. The gas is assumed to be ideal and its solubility given by Henry's law. An analytical solution shows that the diffusive base state is no longer self-similar and that diffusive mass transfer declines rapidly. Scaling analysis reveals that the volume ratio of brine and gas η determines the behavior of the system. DNS show that no constant flux regime exists for η > 0 nevertheless, the quantity F /Cs2 remains constant, where F is the dissolution flux. The onset time is only affected by η when the Rayleigh number Ra is small. In this case, the drop in Cs during the initial diffusive regime significantly reduces the effective Ra and therefore delays the onset.
Directory of Open Access Journals (Sweden)
Jiazhou Wu
2018-06-01
Full Text Available A three-dimensional multiphysical transient model was developed to investigate keyhole formation, weld pool dynamics, and mass transfer in laser welding of dissimilar materials. The coupling of heat transfer, fluid flow, keyhole free surface evolution, and solute diffusion between dissimilar metals was simulated. The adaptive heat source model was used to trace the change of keyhole shape, and the Rayleigh scattering of the laser beam was considered. The keyhole wall was calculated using the fluid volume equation, primarily considering the recoil pressure induced by metal evaporation, surface tension, and hydrostatic pressure. Fluid flow, diffusion, and keyhole formation were considered simultaneously in mass transport processes. Welding experiments of 304L stainless steel and industrial pure titanium TA2 were performed to verify the simulation results. It is shown that spatters are shaped during the welding process. The thickness of the intermetallic reaction layer between the two metals and the diffusion of elements in the weld are calculated, which are important criteria for welding quality. The simulation results correspond well with the experimental results.
International Nuclear Information System (INIS)
Ryabov, E.G.; Karpov, A.V.; Adeev, G.D.
2006-01-01
Dependence of fission fragments mass distribution on the angular momentum within Langevin dynamics is studied. The calculations are performed in the framework of the rotating temperature-dependent finite-range liquid drop model. The calculations are done for the five nuclei, representing heavy fissioning nuclei, medium fissioning nuclei and light fissioning one with the angular momentum varied in the wide range from l=0 to l=70-bar . The dependence coefficients dσ M 2 /dl 2 for the investigated nuclei are extracted. The comparison of the extracted values with the experimental data reveals a good agreement for all the cases (the heavy, medium, and light fissioning nuclei). It is found out that the obtained dependence of σ M 2 on l can be explained with the help of temperature at scission as a function of l. The latter dependence is determined by dependence of the mean prescission neutron multiplicity on l. The analysis of this dependence is done as a competition between fission process and neutron evaporation. 'Remembering of the former large fluctuations of mass asymmetry coordinate during descent from the saddle to scission' is considered. It is shown that the 'remembering effect' takes place, but does not play a crucial role for the investigated dependence of σ M 2 on l
General relativistic dynamics of an extreme mass-ratio binary interacting with an external body
Yang, Huan; Casals, Marc
2017-10-01
We study the dynamics of a hierarchical three-body system in the general relativistic regime: an extreme mass-ratio inner binary under the tidal influence of an external body. The inner binary consists of a central Schwarzschild black hole and a test body moving around it. We discuss three types of tidal effects on the orbit of the test body. First, the angular momentum of the inner binary precesses around the angular momentum of the outer binary. Second, the tidal field drives a "transient resonance" when the radial and azimuthal frequencies are commensurable. In contrast with resonances driven by the gravitational self-force, this tidal-driven resonance may boost the orbital angular momentum and eccentricity (a relativistic version of the Kozai-Lidov effect). Finally, for an orbit-dynamical effect during the nonresonant phase, we calculate the correction to the innermost stable circular (mean) orbit due to the tidal interaction. Hierarchical three-body systems are potential sources for future space-based gravitational wave missions, and the tidal effects that we find could contribute significantly to their waveform.
Optimal control landscape for the generation of unitary transformations with constrained dynamics
International Nuclear Information System (INIS)
Hsieh, Michael; Wu, Rebing; Rabitz, Herschel; Lidar, Daniel
2010-01-01
The reliable and precise generation of quantum unitary transformations is essential for the realization of a number of fundamental objectives, such as quantum control and quantum information processing. Prior work has explored the optimal control problem of generating such unitary transformations as a surface-optimization problem over the quantum control landscape, defined as a metric for realizing a desired unitary transformation as a function of the control variables. It was found that under the assumption of nondissipative and controllable dynamics, the landscape topology is trap free, which implies that any reasonable optimization heuristic should be able to identify globally optimal solutions. The present work is a control landscape analysis, which incorporates specific constraints in the Hamiltonian that correspond to certain dynamical symmetries in the underlying physical system. It is found that the presence of such symmetries does not destroy the trap-free topology. These findings expand the class of quantum dynamical systems on which control problems are intrinsically amenable to a solution by optimal control.
Energy Technology Data Exchange (ETDEWEB)
Haskins, William E.; Leavell, Michael D.; Lane, Pamela; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Wood, Nichole L.; Schoeniger, Joseph S.; Kruppa, Gary Hermann; Sale, Kenneth L.; Young, Malin M.; Novak, Petr
2005-03-01
Membrane proteins make up a diverse and important subset of proteins for which structural information is limited. In this study, chemical cross-linking and mass spectrometry were used to explore the structure of the G-protein-coupled photoreceptor bovine rhodopsin in the dark-state conformation. All experiments were performed in rod outer segment membranes using amino acid 'handles' in the native protein sequence and thus minimizing perturbations to the native protein structure. Cysteine and lysine residues were covalently cross-linked using commercially available reagents with a range of linker arm lengths. Following chemical digestion of cross-linked protein, cross-linked peptides were identified by accurate mass measurement using liquid chromatography-fourier transform mass spectrometry and an automated data analysis pipeline. Assignments were confirmed and, if necessary, resolved, by tandem MS. The relative reactivity of lysine residues participating in cross-links was evaluated by labeling with NHS-esters. A distinct pattern of cross-link formation within the C-terminal domain, and between loop I and the C-terminal domain, emerged. Theoretical distances based on cross-linking were compared to inter-atomic distances determined from the energy-minimized X-ray crystal structure and Monte Carlo conformational search procedures. In general, the observed cross-links can be explained by re-positioning participating side-chains without significantly altering backbone structure. One exception, between C3 16 and K325, requires backbone motion to bring the reactive atoms into sufficient proximity for cross-linking. Evidence from other studies suggests that residues around K325 for a region of high backbone mobility. These findings show that cross-linking studies can provide insight into the structural dynamics of membrane proteins in their native environment.
a{sub 0}(980) as a dynamically generated resonance in the extended Linear Sigma Model
Energy Technology Data Exchange (ETDEWEB)
Wolkanowski-Gans, Thomas; Giacosa, Francesco [Goethe-Universitaet Frankfurt am Main (Germany)
2014-07-01
We study basic properties of scalar hadronic resonances within the so-called extended linear sigma model (eLSM), which is an effective model of QCD based on chiral symmetry and dilatation invariance. In particular, we focus on the mass and decay width of the isovector state a{sub 0}(1450) and perform a numerical study of the propagator pole(s) on the unphysical Riemann sheets. Here, the a{sub 0}(1450) is understood as a seed state explicitly included in the eLSM - this is in fact not true for the corresponding resonance below 1 GeV, the a{sub 0}(980), which is sometimes interpreted as a kaonic (i.e., dynamically generated) bound state. In our work we want to clarify if the yet not included a{sub 0}(980) can be found as a propagator pole generated by hadronic loop contributions. From such an investigation one could learn more about the general dependence of the eLSM - and effective field models in general - on strongly coupled hadronic intermediate states, possibly giving new insight into the low-energy regime, scalar resonances and both its theoretical description and physical interpretation.
Geostationary secular dynamics revisited: application to high area-to-mass ratio objects
Gachet, Fabien; Celletti, Alessandra; Pucacco, Giuseppe; Efthymiopoulos, Christos
2017-06-01
The long-term dynamics of the geostationary Earth orbits (GEO) is revisited through the application of canonical perturbation theory. We consider a Hamiltonian model accounting for all major perturbations: geopotential at order and degree two, lunisolar perturbations with a realistic model for the Sun and Moon orbits, and solar radiation pressure. The long-term dynamics of the GEO region has been studied both numerically and analytically, in view of the relevance of such studies to the issue of space debris or to the disposal of GEO satellites. Past studies focused on the orbital evolution of objects around a nominal solution, hereafter called the forced equilibrium solution, which shows a particularly strong dependence on the area-to-mass ratio. Here, we (i) give theoretical estimates for the long-term behavior of such orbits, and (ii) we examine the nature of the forced equilibrium itself. In the lowest approximation, the forced equilibrium implies motion with a constant non-zero average `forced eccentricity', as well as a constant non-zero average inclination, otherwise known in satellite dynamics as the inclination of the invariant `Laplace plane'. Using a higher order normal form, we demonstrate that this equilibrium actually represents not a point in phase space, but a trajectory taking place on a lower-dimensional torus. We give analytical expressions for this special trajectory, and we compare our results to those found by numerical orbit propagation. We finally discuss the use of proper elements, i.e., approximate integrals of motion for the GEO orbits.
Xiao, Yiming; Konermann, Lars
2015-08-01
Gas/water interfaces (such as air bubbles or foam) are detrimental to the stability of proteins, often causing aggregation. This represents a potential problem for industrial processes, for example, the production and handling of protein drugs. Proteins possess surfactant-like properties, resulting in a high affinity for gas/water interfaces. The tendency of previously buried nonpolar residues to maximize contact with the gas phase can cause significant structural distortion. Most earlier studies in this area employed spectroscopic tools that could only provide limited information. Here we use hydrogen/deuterium exchange (HDX) mass spectrometry (MS) for probing the conformational dynamics of the model protein myoglobin (Mb) in the presence of N(2) bubbles. HDX/MS relies on the principle that unfolded and/or highly dynamic regions undergo faster deuteration than tightly folded segments. In bubble-free solution Mb displays EX2 behavior, reflecting the occurrence of short-lived excursions to partially unfolded conformers. A dramatically different behavior is seen in the presence of N(2) bubbles; EX2 dynamics still take place, but in addition the protein shows EX1 behavior. The latter results from interconversion of the native state with conformers that are globally unfolded and long-lived. These unfolded species likely correspond to Mb that is adsorbed to the surface of gas bubbles. N(2) sparging also induces aggregation. To explain the observed behavior we propose a simple model, that is, "semi-unfolded" ↔ "native" ↔ "globally unfolded" → "aggregated". This model quantitatively reproduces the experimentally observed kinetics. To the best of our knowledge, the current study marks the first exploration of surface denaturation phenomena by HDX/MS. © 2015 The Protein Society.
International Nuclear Information System (INIS)
Liu, Hanghui; Lam, Lily; Yan, Lin; Chi, Bert; Dasgupta, Purnendu K.
2014-01-01
Highlights: • Less abundant isotopologue ions were utilized to decrease detector saturation. • A 25–50 fold increase in the upper limit of dynamic range was demonstrated. • Linear dynamic range was expanded without compromising mass resolution. - Abstract: The linear dynamic range (LDR) for quantitative liquid chromatography–mass spectrometry can be extended until ionization saturation is reached by using a number of target isotopologue ions in addition to the normally used target ion that provides the highest sensitivity. Less abundant isotopologue ions extend the LDR: the lower ion abundance decreases the probability of ion detector saturation. Effectively the sensitivity decreases and the upper limit of the LDR increases. We show in this paper that the technique is particularly powerful with a high resolution time of flight mass spectrometer because the data for all ions are automatically acquired, and we demonstrated this for four small organic molecules; the upper limits of LDRs increased by 25–50 times
Energy Technology Data Exchange (ETDEWEB)
Rasmussen, Rasmus W.; Winter, Walter
2016-11-15
We discuss the parameter space reach of future experiments searching for heavy neutral leptons (HNLs) at the GeV scale in terms of neutrino mass models with three HNL generations. We focus on two classes of models: Generic assumptions (such as random mass matrices or the Casas-Ibarra parameterization) and flavor symmetry-generated models. We demonstrate that the generic approaches lead to comparable parameter space predictions, which tend to be at least partially within the reach of future experiments. On the other hand, specific flavor symmetry models yield more refined predictions, some of these can be more clearly excluded. We also highlight the importance to measure the flavor-dependent couplings of the HNLs as a model discriminator, and we clarify the impact of assumptions frequently used in the literature to show the parameter space reach for the active-sterile mixings.
International Nuclear Information System (INIS)
Rasmussen, Rasmus W.; Winter, Walter
2016-11-01
We discuss the parameter space reach of future experiments searching for heavy neutral leptons (HNLs) at the GeV scale in terms of neutrino mass models with three HNL generations. We focus on two classes of models: Generic assumptions (such as random mass matrices or the Casas-Ibarra parameterization) and flavor symmetry-generated models. We demonstrate that the generic approaches lead to comparable parameter space predictions, which tend to be at least partially within the reach of future experiments. On the other hand, specific flavor symmetry models yield more refined predictions, some of these can be more clearly excluded. We also highlight the importance to measure the flavor-dependent couplings of the HNLs as a model discriminator, and we clarify the impact of assumptions frequently used in the literature to show the parameter space reach for the active-sterile mixings.
System Dynamics Simulation of Large-Scale Generation System for Designing Wind Power Policy in China
Directory of Open Access Journals (Sweden)
Linna Hou
2015-01-01
Full Text Available This paper focuses on the impacts of renewable energy policy on a large-scale power generation system, including thermal power, hydropower, and wind power generation. As one of the most important clean energy, wind energy has been rapidly developed in the world. But in recent years there is a serious waste of wind power equipment and investment in China leading to many problems in the industry from wind power planning to its integration. One way overcoming the difficulty is to analyze the influence of wind power policy on a generation system. This paper builds a system dynamics (SD model of energy generation to simulate the results of wind energy generation policies based on a complex system. And scenario analysis method is used to compare the effectiveness and efficiency of these policies. The case study shows that the combinations of lower portfolio goal and higher benchmark price and those of higher portfolio goal and lower benchmark price have large differences in both effectiveness and efficiency. On the other hand, the combinations of uniformly lower or higher portfolio goal and benchmark price have similar efficiency, but different effectiveness. Finally, an optimal policy combination can be chosen on the basis of policy analysis in the large-scale power system.
Directory of Open Access Journals (Sweden)
M. Varga
2016-03-01
Full Text Available This paper introduces a GIS based methodology to generate dynamic process model for the simulation based analysis of a sensitive rural watershed. The Direct Computer Mapping (DCM based solution starts from GIS layers and, via the graph interpretation and graphical edition of the process network, the expert interface is able to integrate the field experts’ knowledge in the computer aided generation of the simulation model. The methodology was applied and tested for the Southern catchment basin of Lake Balaton, Hungary. In the simplified hydrological model the GIS description of nine watercourses, 121 water sections, 57 small lakes and 20 Lake Balaton compartments were mapped through the expert interface to the dynamic databases of the DCM model. The hydrological model involved precipitation, evaporation, transpiration, runoff, infiltration. The COoRdination of INformation on the Environment (CORINE land cover based simplified “land patch” model considered the effect of meteorological and hydrological scenarios on freshwater resources in the land patches, rivers and lakes. The first results show that the applied model generation methodology helps to build complex models, which, after validation can support the analysis of various land use, with the consideration of environmental aspects.
Mobile Charge Generation Dynamics in P3HT:PCBM Observed by Time-Resolved Terahertz Spectroscopy
DEFF Research Database (Denmark)
Cooke, D. G.; Krebs, Frederik C; Jepsen, Peter Uhd
2012-01-01
Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale.......Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale....
Directory of Open Access Journals (Sweden)
Wassim M. Haddad
2013-05-01
Full Text Available In this paper, we combine the two universalisms of thermodynamics and dynamical systems theory to develop a dynamical system formalism for classical thermodynamics. Specifically, using a compartmental dynamical system energy flow model involving heat flow, work energy, and chemical reactions, we develop a state-space dynamical system model that captures the key aspects of thermodynamics, including its fundamental laws. In addition, we show that our thermodynamically consistent dynamical system model is globally semistable with system states converging to a state of temperature equipartition. Furthermore, in the presence of chemical reactions, we use the law of mass-action and the notion of chemical potential to show that the dynamic system states converge to a state of temperature equipartition and zero affinity corresponding to a state of chemical equilibrium.
Sunnåker, Mikael; Zamora-Sillero, Elias; Dechant, Reinhard; Ludwig, Christina; Busetto, Alberto Giovanni; Wagner, Andreas; Stelling, Joerg
2013-05-28
Predictive dynamical models are critical for the analysis of complex biological systems. However, methods to systematically develop and discriminate among systems biology models are still lacking. We describe a computational method that incorporates all hypothetical mechanisms about the architecture of a biological system into a single model and automatically generates a set of simpler models compatible with observational data. As a proof of principle, we analyzed the dynamic control of the transcription factor Msn2 in Saccharomyces cerevisiae, specifically the short-term mechanisms mediating the cells' recovery after release from starvation stress. Our method determined that 12 of 192 possible models were compatible with available Msn2 localization data. Iterations between model predictions and rationally designed phosphoproteomics and imaging experiments identified a single-circuit topology with a relative probability of 99% among the 192 models. Model analysis revealed that the coupling of dynamic phenomena in Msn2 phosphorylation and transport could lead to efficient stress response signaling by establishing a rate-of-change sensor. Similar principles could apply to mammalian stress response pathways. Systematic construction of dynamic models may yield detailed insight into nonobvious molecular mechanisms.
Band Edge Dynamics and Multiexciton Generation in Narrow Band Gap HgTe Nanocrystals.
Livache, Clément; Goubet, Nicolas; Martinez, Bertille; Jagtap, Amardeep; Qu, Junling; Ithurria, Sandrine; Silly, Mathieu G; Dubertret, Benoit; Lhuillier, Emmanuel
2018-04-11
Mercury chalcogenide nanocrystals and especially HgTe appear as an interesting platform for the design of low cost mid-infrared (mid-IR) detectors. Nevertheless, their electronic structure and transport properties remain poorly understood, and some critical aspects such as the carrier relaxation dynamics at the band edge have been pushed under the rug. Some of the previous reports on dynamics are setup-limited, and all of them have been obtained using photon energy far above the band edge. These observations raise two main questions: (i) what are the carrier dynamics at the band edge and (ii) should we expect some additional effect (multiexciton generation (MEG)) as such narrow band gap materials are excited far above the band edge? To answer these questions, we developed a high-bandwidth setup that allows us to understand and compare the carrier dynamics resonantly pumped at the band edge in the mid-IR and far above the band edge. We demonstrate that fast (>50 MHz) photoresponse can be obtained even in the mid-IR and that MEG is occurring in HgTe nanocrystal arrays with a threshold around 3 times the band edge energy. Furthermore, the photoresponse can be effectively tuned in magnitude and sign using a phototransistor configuration.
Transient dynamics of the flow around a NACA 0015 airfoil using fluidic vortex generators
Energy Technology Data Exchange (ETDEWEB)
Siauw, W.L. [Institut Pprime, CNRS - Universite de Poitiers - ENSMA, UPR 3346, Departement Fluides, Thermique, Combustion, ENSMA - Teleport 2, 1 Avenue Clement Ader, BP 40109, F-86961 Futuroscope Chasseneuil Cedex (France); Bonnet, J.-P., E-mail: Jean-Paul.Bonnet@univ-poitiers.f [Institut Pprime, CNRS - Universite de Poitiers - ENSMA, UPR 3346, Departement Fluides, Thermique, Combustion, CEAT, 43 rue de l' Aerodrome, F-86036 Poitiers Cedex (France); Tensi, J., E-mail: Jean.Tensi@lea.univ-poitiers.f [Institut Pprime, CNRS - Universite de Poitiers - ENSMA, UPR 3346, Departement Fluides, Thermique, Combustion, ENSMA - Teleport 2, 1 Avenue Clement Ader, BP 40109, F-86961 Futuroscope Chasseneuil Cedex (France); Cordier, L., E-mail: Laurent.Cordier@univ-poitiers.f [Institut Pprime, CNRS - Universite de Poitiers - ENSMA, UPR 3346, Departement Fluides, Thermique, Combustion, CEAT, 43 rue de l' Aerodrome, F-86036 Poitiers Cedex (France); Noack, B.R., E-mail: Bernd.Noack@univ-poitiers.f [Institut Pprime, CNRS - Universite de Poitiers - ENSMA, UPR 3346, Departement Fluides, Thermique, Combustion, CEAT, 43 rue de l' Aerodrome, F-86036 Poitiers Cedex (France); Cattafesta, L., E-mail: cattafes@ufl.ed [Florida Center for Advanced Aero-Propulsion (FCAAP), Department of Mechanical and Aerospace Engineering, University of Florida, 231 MAE-A, Gainesville, FL 32611 (United States)
2010-06-15
The unsteady activation or deactivation of fluidic vortex generators on a NACA 0015 airfoil is studied to understand the transient dynamics of flow separation control. The Reynolds number is high enough and the boundary layer is tripped, so the boundary layer is fully turbulent prior to separation. Conditional PIV of the airfoil wake is obtained phase-locked to the actuator trigger signal, allowing reconstruction of the transient processes. When the actuators are impulsively turned on, the velocity field in the near wake exhibit a complex transient behavior associated with the formation and shedding of a starting vortex. When actuation is stopped, a more gradual process of the separation dynamics is found. These results are in agreement with those found in the literature in comparable configurations. Proper Orthogonal Decomposition of phase-locked velocity fields reveals low-dimensional transient dynamics for the attachment and separation processes, with 98% of the fluctuation energy captured by the first four modes. The behavior is quantitatively well captured by a four-dimensional dynamical system with the corresponding mode amplitudes. Analysis of the first temporal POD modes accurately determines typical time scales for attachment and separation processes to be respectively t{sup +}=10 and 20 in conventional non-dimensional values. This study adds to experimental investigations of this scale with essential insight for the targeted closed-loop control.
Generation, language, body mass index, and activity patterns in Hispanic children.
Taverno, Sharon E; Rollins, Brandi Y; Francis, Lori A
2010-02-01
The acculturation hypothesis proposes an overall disadvantage in health outcomes for Hispanic immigrants with more time spent living in the U.S., but little is known about how generational status and language may influence Hispanic children's relative weight and activity patterns. To investigate associations among generation and language with relative weight (BMI z-scores), physical activity, screen time, and participation in extracurricular activities (i.e., sports, clubs) in a U.S.-based, nationally representative sample of Hispanic children. Participants included 2012 Hispanic children aged 6-11 years from the cross-sectional 2003 National Survey of Children's Health. Children were grouped according to generational status (first, second, or third), and the primary language spoken in the home (English versus non-English). Primary analyses included adjusted logistic and multinomial logistic regression to examine the relationships among variables; all analyses were conducted between 2008 and 2009. Compared to third-generation, English speakers, first- and second-generation, non-English speakers were more than two times more likely to be obese. Moreover, first-generation, non-English speakers were half as likely to engage in regular physical activity and sports. Both first- and second-generation, non-English speakers were less likely to participate in clubs compared to second- and third-generation, English speakers. Overall, non-English-speaking groups reported less screen time compared to third-generation, English speakers. The hypothesis that Hispanics lose their health protection with more time spent in the U.S. was not supported in this sample of Hispanic children. Copyright 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.