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Sample records for late time solutions

  1. Late time solution for interacting scalar in accelerating spaces

    Energy Technology Data Exchange (ETDEWEB)

    Prokopec, Tomislav, E-mail: t.prokopec@uu.nl [Institute for Theoretical Physics, Spinoza Institute and EMME$\\Phi$, Utrecht University, Postbus 80.195, Utrecht, 3508 TD The Netherlands (Netherlands)

    2015-11-01

    We consider stochastic inflation in an interacting scalar field in spatially homogeneous accelerating space-times with a constant principal slow roll parameter ε. We show that, if the scalar potential is scale invariant (which is the case when scalar contains quartic self-interaction and couples non-minimally to gravity), the late-time solution on accelerating FLRW spaces can be described by a probability distribution function (PDF) ρ which is a function of φ/H only, where φ=φ( x-vector ) is the scalar field and H=H(t) denotes the Hubble parameter. We give explicit late-time solutions for ρarrow ρ{sub ∞}(φ/H), and thereby find the order ε corrections to the Starobinsky-Yokoyama result. This PDF can then be used to calculate e.g. various n-point functions of the (self-interacting) scalar field, which are valid at late times in arbitrary accelerating space-times with ε= constant.

  2. Archimedean-type force in a cosmic dark fluid. I. Exact solutions for the late-time accelerated expansion

    International Nuclear Information System (INIS)

    Balakin, Alexander B.; Bochkarev, Vladimir V.

    2011-01-01

    We establish a new self-consistent model in order to explain from a unified viewpoint two key features of the cosmological evolution: the inflation in the early Universe and the late-time accelerated expansion. The key element of this new model is the Archimedean-type coupling of the dark matter with dark energy, which form the so-called cosmic dark fluid. We suppose that dark matter particles immersed into the dark energy reservoir are affected by the force proportional to the four-gradient of the dark energy pressure. The Archimedean-type coupling is shown to play a role of effective energy-momentum redistributor between the dark matter and the dark energy components of the dark fluid, thus providing the Universe evolution to be a quasiperiodic and/or multistage process. In the first part of the work we discuss a theoretical base and new exact solutions of the model master equations. Special attention is focused on the exact solutions, for which the scale factor is presented by the anti-Gaussian function: these solutions describe the late-time acceleration and are characterized by a nonsingular behavior in the early Universe. The second part contains qualitative and numerical analysis of the master equations; we focus there on the solutions describing a multi-inflationary Universe.

  3. Intermediate accelerated solutions as generic late-time attractors in a modified Jordan-Brans-Dicke theory

    Energy Technology Data Exchange (ETDEWEB)

    Cid, Antonella [Grupo de Cosmología y Gravitación GCG-UBB and Departamento de Física, Universidad del Bío-Bío, Casilla 5-C, Concepción (Chile); Leon, Genly [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4950, Valparaíso (Chile); Leyva, Yoelsy, E-mail: acidm@ubiobio.cl, E-mail: genly.leon@ucv.cl, E-mail: yoelsy.leyva@uta.cl [Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Casilla 7-D, Arica (Chile)

    2016-02-01

    In this paper we investigate the evolution of a Jordan-Brans-Dicke scalar field, Φ, with a power-law potential in the presence of a second scalar field, φ, with an exponential potential, in both the Jordan and the Einstein frames. We present the relation of our model with the induced gravity model with power-law potential and the integrability of this kind of models is discussed when the quintessence field φ is massless, and has a small velocity. The fact that for some fine-tuned values of the parameters we may get some integrable cosmological models, makes our choice of potentials very interesting. We prove that in Jordan-Brans-Dicke theory, the de Sitter solution is not a natural attractor. Instead, we show that the attractor in the Jordan frame corresponds to an ''intermediate accelerated'' solution of the form a(t) ≅ e{sup α{sub 1} t{sup p{sup {sub 1}}}}, as t → ∞ where α{sub 1} > 0 and 0 < p{sub 1} < 1, for a wide range of parameters. Furthermore, when we work in the Einstein frame we get that the attractor is also an ''intermediate accelerated'' solution of the form a(t) ≅ e{sup α{sub 2} tp{sub 2}} as t → ∞ where α{sub 2} > 0 and 0solutions are of saddle type. These results were proved using the center manifold theorem, which is not based on linear approximation. Finally, we present a specific elaboration of our extension of the induced gravity model in the Jordan frame, which corresponds to a particular choice of a linear potential of Φ. The dynamical system is then reduced to a two dimensional one, and the late-time attractor is linked with the exact solution found for the induced gravity model. In this example the ''intermediate accelerated

  4. Intermediate accelerated solutions as generic late-time attractors in a modified Jordan-Brans-Dicke theory

    International Nuclear Information System (INIS)

    Cid, Antonella; Leon, Genly; Leyva, Yoelsy

    2016-01-01

    In this paper we investigate the evolution of a Jordan-Brans-Dicke scalar field, Φ, with a power-law potential in the presence of a second scalar field, φ, with an exponential potential, in both the Jordan and the Einstein frames. We present the relation of our model with the induced gravity model with power-law potential and the integrability of this kind of models is discussed when the quintessence field φ is massless, and has a small velocity. The fact that for some fine-tuned values of the parameters we may get some integrable cosmological models, makes our choice of potentials very interesting. We prove that in Jordan-Brans-Dicke theory, the de Sitter solution is not a natural attractor. Instead, we show that the attractor in the Jordan frame corresponds to an ''intermediate accelerated'' solution of the form a(t) ≅ e α 1  t p 1 , as t → ∞ where α 1  > 0 and 0 < p 1  < 1, for a wide range of parameters. Furthermore, when we work in the Einstein frame we get that the attractor is also an ''intermediate accelerated'' solution of the form a(t) ≅ e α 2  tp 2 as t → ∞ where α 2  > 0 and 0

    solutions are of saddle type. These results were proved using the center manifold theorem, which is not based on linear approximation. Finally, we present a specific elaboration of our extension of the induced gravity model in the Jordan frame, which corresponds to a particular choice of a linear potential of Φ. The dynamical system is then reduced to a two dimensional one, and the late-time attractor is linked with the exact solution found for the induced gravity model. In this example the ''intermediate accelerated'' solution does not exist, and the attractor

  5. Intermediate Inflation or Late Time Acceleration?

    International Nuclear Information System (INIS)

    Sanyal, A.K.

    2008-01-01

    The expansion rate of intermediate inflation lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of intermediate inflation reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.

  6. Consequences of energy conservation violation: late time solutions of Λ(T)CDM subclass of f(R,T) gravity using dynamical system approach

    Energy Technology Data Exchange (ETDEWEB)

    Shabani, Hamid [University of Sistan and Baluchestan, Physics Department, Faculty of Sciences, Zahedan (Iran, Islamic Republic of); Ziaie, Amir Hadi [Islamic Azad University, Department of Physics, Kahnooj Branch, Kerman (Iran, Islamic Republic of)

    2017-05-15

    Very recently, Josset and Perez (Phys. Rev. Lett. 118:021102, 2017) have shown that a violation of the energy-momentum tensor (EMT) could result in an accelerated expansion state via the appearance of an effective cosmological constant, in the context of unimodular gravity. Inspired by this outcome, in this paper we investigate cosmological consequences of a violation of the EMT conservation in a particular class of f(R,T) gravity when only the pressure-less fluid is present. In this respect, we focus on the late time solutions of models of the type f(R,T) = R + βΛ(-T). As the first task, we study the solutions when the conservation of EMT is respected, and then we proceed with those in which violation occurs. We have found, provided that the EMT conservation is violated, that there generally exist two accelerated expansion solutions of which the stability properties depend on the underlying model. More exactly, we obtain a dark energy solution for which the effective equation of state depends on the model parameters and a de Sitter solution. We present a method to parametrize the Λ(-T) function, which is useful in a dynamical system approach and has been employed in the model. Also, we discuss the cosmological solutions for models with Λ(-T) = 8πG(-T){sup α} in the presence of ultra-relativistic matter. (orig.)

  7. 2D CFT partition functions at late times

    Science.gov (United States)

    Dyer, Ethan; Gur-Ari, Guy

    2017-08-01

    We consider the late time behavior of the analytically continued partition function Z( β + it) Z( β - it) in holographic 2 d CFTs. This is a probe of information loss in such theories and in their holographic duals. We show that each Virasoro character decays in time, and so information is not restored at the level of individual characters. We identify a universal decaying contribution at late times, and conjecture that it describes the behavior of generic chaotic 2 d CFTs out to times that are exponentially large in the central charge. It was recently suggested that at sufficiently late times one expects a crossover to random matrix behavior. We estimate an upper bound on the crossover time, which suggests that the decay is followed by a parametrically long period of late time growth. Finally, we discuss gravitationally-motivated integrable theories and show how information is restored at late times by a series of characters. This hints at a possible bulk mechanism, where information is restored by an infinite sum over non-perturbative saddles.

  8. Late-time cosmological phase transitions

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1990-11-01

    It is shown that the potential galaxy formation and large-scale structure problems of objects existing at high redshifts (Z approx-gt 5), structures existing on scales of 100M pc as well as velocity flows on such scales, and minimal microwave anisotropies (ΔT/T) approx-lt 10 -5 can be solved if the seeds needed to generate structure form in a vacuum phase transition after decoupling. It is argued that the basic physics of such a phase transition is no more exotic than that utilized in the more traditional GUT scale phase transitions, and that, just as in the GUT case, significant random gaussian fluctuations and/or topological defects can form. Scale lengths of ∼100M pc for large-scale structure as well as ∼1 M pc for galaxy formation occur naturally. Possible support for new physics that might be associated with such a late-time transition comes from the preliminary results of the SAGE solar neutrino experiment, implying neutrino flavor mixing with values similar to those required for a late-time transition. It is also noted that a see-saw model for the neutrino masses might also imply a tau neutrino mass that is an ideal hot dark matter candidate. However, in general either hot or cold dark matter can be consistent with a late-time transition. 47 refs., 2 figs

  9. Late time acceleration in a non-commutative model of modified cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Malekolkalami, B., E-mail: b.malakolkalami@uok.ac.ir [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Atazadeh, K., E-mail: atazadeh@azaruniv.ac.ir [Department of Physics, Azarbaijan Shahid Madani University, 53714-161, Tabriz (Iran, Islamic Republic of); Vakili, B., E-mail: b-vakili@iauc.ac.ir [Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2014-12-12

    We investigate the effects of non-commutativity between the position–position, position–momentum and momentum–momentum of a phase space corresponding to a modified cosmological model. We show that the existence of such non-commutativity results in a Moyal Poisson algebra between the phase space variables in which the product law between the functions is of the kind of an α-deformed product. We then transform the variables in such a way that the Poisson brackets between the dynamical variables take the form of a usual Poisson bracket but this time with a noncommutative structure. For a power law expression for the function of the Ricci scalar with which the action of the gravity model is modified, the exact solutions in the commutative and noncommutative cases are presented and compared. In terms of these solutions we address the issue of the late time acceleration in cosmic evolution.

  10. Late time acceleration in a non-commutative model of modified cosmology

    International Nuclear Information System (INIS)

    Malekolkalami, B.; Atazadeh, K.; Vakili, B.

    2014-01-01

    We investigate the effects of non-commutativity between the position–position, position–momentum and momentum–momentum of a phase space corresponding to a modified cosmological model. We show that the existence of such non-commutativity results in a Moyal Poisson algebra between the phase space variables in which the product law between the functions is of the kind of an α-deformed product. We then transform the variables in such a way that the Poisson brackets between the dynamical variables take the form of a usual Poisson bracket but this time with a noncommutative structure. For a power law expression for the function of the Ricci scalar with which the action of the gravity model is modified, the exact solutions in the commutative and noncommutative cases are presented and compared. In terms of these solutions we address the issue of the late time acceleration in cosmic evolution

  11. Late-time structure of the Bunch-Davies de Sitter wavefunction

    Energy Technology Data Exchange (ETDEWEB)

    Anninos, Dionysios [Stanford Institute of Theoretical Physics, Stanford University, Stanford (United States); Anous, Tarek [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge (United States); Freedman, Daniel Z. [Stanford Institute of Theoretical Physics, Stanford University, Stanford (United States); Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge (United States); Department of Mathematics, Massachusetts Institute of Technology, Cambridge (United States); Konstantinidis, George [Stanford Institute of Theoretical Physics, Stanford University, Stanford (United States)

    2015-11-30

    We examine the late time behavior of the Bunch-Davies wavefunction for interacting light fields in a de Sitter background. We use perturbative techniques developed in the framework of AdS/CFT, and analytically continue to compute tree and loop level contributions to the Bunch-Davies wavefunction. We consider self-interacting scalars of general mass, but focus especially on the massless and conformally coupled cases. We show that certain contributions grow logarithmically in conformal time both at tree and loop level. We also consider gauge fields and gravitons. The four-dimensional Fefferman-Graham expansion of classical asymptotically de Sitter solutions is used to show that the wavefunction contains no logarithmic growth in the pure graviton sector at tree level. Finally, assuming a holographic relation between the wavefunction and the partition function of a conformal field theory, we interpret the logarithmic growths in the language of conformal field theory.

  12. Maximum Lateness Scheduling on Two-Person Cooperative Games with Variable Processing Times and Common Due Date

    Directory of Open Access Journals (Sweden)

    Peng Liu

    2017-01-01

    Full Text Available A new maximum lateness scheduling model in which both cooperative games and variable processing times exist simultaneously is considered in this paper. The job variable processing time is described by an increasing or a decreasing function dependent on the position of a job in the sequence. Two persons have to cooperate in order to process a set of jobs. Each of them has a single machine and their processing cost is defined as the minimum value of maximum lateness. All jobs have a common due date. The objective is to maximize the multiplication of their rational positive cooperative profits. A division of those jobs should be negotiated to yield a reasonable cooperative profit allocation scheme acceptable to them. We propose the sufficient and necessary conditions for the problems to have positive integer solution.

  13. Hot Dust! Late-Time Infrared Emission From Supernovae

    Science.gov (United States)

    Fox, Ori; Skrutskie, M. F.; Chevalier, R. A.

    2010-01-01

    Supernovae light curves typically peak and fade in the course of several months. Some supernovae , however, exhibit late-time infrared emission that in some cases can last for several years. These supernovae tend to be of the Type IIn subclass, which is defined by narrow hydrogen and helium emission lines arising from a dense, pre-existing circumstellar medium excited by the supernova radiation. Such a late-time ``IR excess'' with respect to the optical blackbody counterpart typically indicates the presence of warm dust. The origin and heating mechanism of the dust is not, however, always well constrained. In this talk, I will explore several scenarios that explain the observed late-time emission. In particular, I will discuss the case of the Type IIn SN 2005ip, which has displayed an ``IR excess'' for over 3 years. The results allow us to interpret the progenitor system and better understand the late stages of stellar evolution. Much of the data used for this analysis were obtained with TripleSpec, a medium-resolution near-infrared spectrograph located at Apache Point Observatory, NM, and FanCam, a JHK imager located at Fan Mountain Observatory, just outside of Charlottesville, VA. These two instruments were designed, fabricated, built, and commissioned by our instrumentation group at the University of Virginia. I will also spend some time discussing these instruments. I would like to thank the following for financial support of this work throughout my graduate career: NASA GSRP, NSF AAG-0607737, Spitzer PID 50256, Achievement Reward for College Scientists (ARCS), and the Virginia Space Grant Consortium.

  14. Late-time cosmological evolution of a general class of f(R, T) gravity with minimal curvature-matter coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shabani, Hamid [University of Sistan and Baluchestan, Physics Department, Faculty of Sciences, Zahedan (Iran, Islamic Republic of); Ziaie, Amir Hadi [Islamic Azad University, Department of Physics, Kahnooj Branch, Kerman (Iran, Islamic Republic of)

    2017-08-15

    In this work, we study the late-time cosmological solutions of f(R, T) = g(R) + h(-T) models assuming that the conservation of the energy-momentum tensor (EMT) is violated. We perform our analysis through constructing an autonomous dynamical system for the equations of motion. We study the stability properties of solutions via considering linear perturbations about the related equilibrium points. Moreover, we parameterize the Lagrangian by introducing the parameters m(r) and n(s). These parameters which are constructed out of the functions g(R) and h(-T) play the main role in finding the late-time behavior of the solutions. We find that there exist, in general, three classes of solutions; all models with n > 0 include a proper transition from a prolonged matter era to a de Sitter solution. Models with -0.5 < n < 0 and n{sup '} > 1, for at least a root of equation n(s) = s - 1, include an unphysical dark energy solution preceding an improper matter era. Finally, for n < -1/2 there is a transient accelerated expansion era with -1/2 < w{sup (eff)} < -1/3 before a de Sitter phase. For all cases, in order to have a long enough matter dominated epoch, the condition m{sup '} → 0{sup +} for r

  15. Late-time dynamics of rapidly rotating black holes

    International Nuclear Information System (INIS)

    Glampedakis, K.; Andersson, N.

    2001-01-01

    We study the late-time behaviour of a dynamically perturbed rapidly rotating black hole. Considering an extreme Kerr black hole, we show that the large number of virtually undamped quasinormal modes (that exist for nonzero values of the azimuthal eigenvalue m) combine in such a way that the field (as observed at infinity) oscillates with an amplitude that decays as 1/t at late times. For a near extreme black hole, these modes, collectively, give rise to an exponentially decaying field which, however, is considerably 'long-lived'. Our analytic results are verified using numerical time-evolutions of the Teukolsky equation. Moreover, we argue that the physical mechanism behind the observed behaviour is the presence of a 'superradiance resonance cavity' immediately outside the black hole. We present this new feature in detail, and discuss whether it may be relevant for astrophysical black holes. (author)

  16. Late-time tails of wave propagation in higher dimensional spacetimes

    International Nuclear Information System (INIS)

    Cardoso, Vitor; Yoshida, Shijun; Dias, Oscar J.C.; Lemos, Jose P.S.

    2003-01-01

    We study the late-time tails appearing in the propagation of massless fields (scalar, electromagnetic, and gravitational) in the vicinities of a D-dimensional Schwarzschild black hole. We find that at late times the fields always exhibit a power-law falloff, but the power law is highly sensitive to the dimensionality of the spacetime. Accordingly, for odd D>3 we find that the field behaves as t -(2l+D-2) at late times, where l is the angular index determining the angular dependence of the field. This behavior is entirely due to D being odd; it does not depend on the presence of a black hole in the spacetime. Indeed this tail is already present in the flat space Green's function. On the other hand, for even D>4 the field decays as t -(2l+3D-8) , and this time there is no contribution from the flat background. This power law is entirely due to the presence of the black hole. The D=4 case is special and exhibits, as is well known, t -(2l+3) behavior. In the extra dimensional scenario for our Universe, our results are strictly correct if the extra dimensions are infinite, but also give a good description of the late-time behavior of any field if the large extra dimensions are large enough

  17. On the late-time behavior of tracer test breakthrough curves

    Energy Technology Data Exchange (ETDEWEB)

    HAGGERTY, ROY; MCKENNA, SEAN A; MEIGS, LUCY C

    2000-06-12

    The authors investigated the late-time (asymptotic) behavior of tracer test breakthrough curves (BTCs) with rate-limited mass transfer (e.g., in dual or multi-porosity systems) and found that the late-time concentration, c, is given by the simple expression: c = t{sub ad} (c{sub 0}g {minus} m{sub 0}{partial_derivative}g/{partial_derivative}t), for t >> t{sub ad} and t{sub a} >> t{sub ad} where t{sub ad} is the advection time, c{sub 0} is the initial concentration in the medium, m{sub 0} is the 0th moment of the injection pulse; and t{sub a} is the mean residence time in the immobile domain (i.e., the characteristic mass transfer time). The function g is proportional to the residence time distribution in the immobile domain, the authors tabulate g for many geometries, including several distributed (multirate) models of mass transfer. Using this expression they examine the behavior of late-time concentration for a number of mass transfer models. One key results is that if rate-limited mass transfer causes the BTC to behave as a power-law at late-time (i.e., c {approximately} t{sup {minus}k}), then the underlying density function of rate coefficients must also be a power-law with the form a{sup k{minus}}, as a {r_arrow}0. This is true for both density functions of first-order and diffusion rate coefficients. BTCs with k < 3 persisting to the end of the experiment indicate a mean residence time longer than the experiment and possibly infinite, and also suggest an effective rate coefficient that is either undefined or changes as a function of observation time. They apply their analysis to breakthrough curves from Single-Well Injection-Withdrawal tests at the Waste Isolation Pilot Plant, New Mexico.

  18. Late time phase transition as dark energy

    Indian Academy of Sciences (India)

    Abstract. We show that the dark energy field can naturally be described by the scalar condensates of a non-abelian gauge group. This gauge group is unified with the standard model gauge groups and it has a late time phase transition. The small phase transition explains why the positive acceleration of the universe is ...

  19. Radioactive decay of the late-time light curves of GRB-SNe

    Science.gov (United States)

    Misra, Kuntal; Fruchte, Andrew Steven

    2018-04-01

    We present the late-time Hubble Space Telescope observations of two GRB associated supernovae, GRB 030329/SN 2003dh and XRF 060218/SN 2006aj. Using the multi-color data upto ˜ 320 days after the burst, we constrain the late-time decay nature of these supernovae. The decay rates of SN 2003dh are steeper than SN 2006aj. A comparison with two other GRB supernovae, GRB 980425/SN 1998bw and the supernova associated with XRF 020903, shows that the decay rates of SN 2003dh are similar to XRF 020903 and those of SN 2006aj are similar to SN 1998bw. The late-time decay rates are steeper than the 56Co?56Fe radioactive decay rate (0.0098 mag day-1) indicating that there is some leakage of gamma-rays.

  20. Late-time behaviour of the tilted Bianchi type VIh models

    Science.gov (United States)

    Hervik, S.; van den Hoogen, R. J.; Lim, W. C.; Coley, A. A.

    2007-08-01

    We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VIh using dynamical systems methods and numerical experimentation, with an emphasis on their future asymptotic evolution. We determine all of the equilibrium points of the type VIh state space (which correspond to exact self-similar solutions of the Einstein equations, some of which are new), and their stability is investigated. We find that there are vacuum plane-wave solutions that act as future attractors. In the parameter space, a 'loophole' is shown to exist in which there are no stable equilibrium points. We then show that a Hopf-bifurcation can occur resulting in a stable closed orbit (which we refer to as the Mussel attractor) corresponding to points both inside the loophole and points just outside the loophole; in the former case the closed curves act as late-time attractors while in the latter case these attracting curves will co-exist with attracting equilibrium points. In the special Bianchi type III case, centre manifold theory is required to determine the future attractors. Comprehensive numerical experiments are carried out to complement and confirm the analytical results presented. We note that the Bianchi type VIh case is of particular interest in that it contains many different subcases which exhibit many of the different possible future asymptotic behaviours of Bianchi cosmological models.

  1. Late-Time Spectral Observations of Type IIP Supernovae

    Science.gov (United States)

    Silverman, Jeffrey M.; Pickett, Stephanie; Wheeler, J. Craig; Filippenko, Alexei

    2016-01-01

    Type II-Plateau supernovae (SNe IIP) are H-rich explosions that come from red supergiant (RSG) progenitors. Despite the fact that they are the most common subtype of SN, little work has been done on late-time observations of SNe IIP owing to their relative faintness at these epochs. We analyze 91 late-time (older than about 100 days past explosion) optical spectra of 38 SNe IIP, making this the largest sample of SN IIP nebular spectra ever studied. Quantitative criteria from the spectra themselves are employed to determine if an observation is truly nebular, and thus should be included in the study. We measure the fluxes, shapes, and velocities of various emission lines and investigate their temporal evolution. These values are also compared to photometric data in order to search for correlations that may allow us to gain insight into the RSG progenitors of SNe IIP and learn more about the details of the explosion itself.

  2. Late time acceleration of the universe in f(R) gravity model

    International Nuclear Information System (INIS)

    Mukherjee, Ankan

    2014-01-01

    In this work, a new way to look at the nature of late time dynamics of the universe for f(R) gravity models using the contracted Bianchi Identity has been proposed. As the Einstein field equations contain derivatives of the curvature scalar R, the contracted Bianchi identity yields a second order nonlinear differential equation in H, the Hubble parameter. This equation is studied for two particular forms of f(R), and the late time behaviour of the model is discussed. (author)

  3. Wormholes versus black holes: quasinormal ringing at early and late times

    Energy Technology Data Exchange (ETDEWEB)

    Konoplya, R.A. [Theoretical Astrophysics (TAT), Eberhard-Karls University of Tübingen, Auf der Morgenstelle 10, Tübingen 72076 (Germany); Zhidenko, A., E-mail: roman.konoplya@uni-tuebingen.de, E-mail: olexandr.zhydenko@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC (UFABC), Rua Abolição, CEP: 09210-180, Santo André, SP (Brazil)

    2016-12-01

    Recently it has been argued that the phantom thin-shell wormholes matched with the Schwarzschild space-time near the Schwarzschild radius ring like Schwarzschild black holes at early times, but differently at late times [1]. Here we consider perturbations of the wormhole which was constructed without thin-shells: the Bronnikov-Ellis wormhole supported by the phantom matter and electromagnetic field. This wormhole solution is known to be stable under specific equation of state of the phantom matter. We show that if one does not use the above thin-shell matching, the wormhole, depending on the values of its parameters, either rings as the black hole at all times or rings differently also at all times . The wormhole's spectrum, investigated here, posses a number of distinctive features. In the final part we have considered general properties of scattering around arbitrary rotating traversable wormholes. We have found that symmetric and non-symmetric (with respect to the throat) wormholes are qualitatively different in this respect: first, superradiance is allowed only if for those non-symmetric wormholes for which the asymptotic values of the rotation parameters are different on both sides from the throat. Second, the symmetric wormholes cannot mimic effectively the ringing of a black hole at a few various dominant multipoles at the same time, so that the future observations of various events should easily tell the symmetric wormhole from a black hole.

  4. Dynamical Solution to the Problem of a Small Cosmological Constant and Late-Time Cosmic Acceleration

    International Nuclear Information System (INIS)

    Armendariz-Picon, C.; Mukhanov, V.; Steinhardt, Paul J.

    2000-01-01

    Increasing evidence suggests that most of the energy density of the universe consists of a dark energy component with negative pressure that causes the cosmic expansion to accelerate. We address why this component comes to dominate the universe only recently. We present a class of theories based on an evolving scalar field where the explanation is based entirely on internal dynamical properties of the solutions. In the theories we consider, the dynamics causes the scalar field to lock automatically into a negative pressure state at the onset of matter domination such that the present epoch is the earliest possible time consistent with nucleosynthesis restrictions when it can start to dominate

  5. Late time CMB anisotropies constrain mini-charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, C.; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jaeckel, J. [Univ. of Durham, Inst. for Particle Physics Phenomenology (United Kingdom)

    2009-09-15

    Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pair production of such particles. Such a decrement in the photon flux would occur as photons from the CMB traverse the magnetic fields of galaxy clusters. Therefore late time CMB anisotropies can be used to constrain the properties of mini- charged particles. We outline how this test is constructed, and present new constraints on mini-charged particles from observations of the Sunyaev-Zel'dovich effect in the Coma cluster. (orig.)

  6. SUPERLUMINOUS SUPERNOVAE POWERED BY MAGNETARS: LATE-TIME LIGHT CURVES AND HARD EMISSION LEAKAGE

    International Nuclear Information System (INIS)

    Wang, S. Q.; Wang, L. J.; Dai, Z. G.; Wu, X. F.

    2015-01-01

    Recently, research performed by two groups has revealed that the magnetar spin-down energy injection model with full energy trapping can explain the early-time light curves of SN 2010gx, SN 2013dg, LSQ12dlf, SSS120810, and CSS121015 but fails to fit the late-time light curves of these superluminous supernovae (SLSNe). These results imply that the original magnetar-powered model is challenged in explaining these SLSNe. Our paper aims to simultaneously explain both the early- and late-time data/upper limits by considering the leakage of hard emissions. We incorporate quantitatively the leakage effect into the original magnetar-powered model and derive a new semianalytical equation. Comparing the light curves reproduced by our revised magnetar-powered model with the observed data and/or upper limits of these five SLSNe, we found that the late-time light curves reproduced by our semianalytical equation are in good agreement with the late-time observed data and/or upper limits of SN 2010gx, CSS121015, SN 2013dg, and LSQ12dlf and the late-time excess of SSS120810, indicating that the magnetar-powered model might be responsible for these SLSNe and that the gamma-ray and X-ray leakages are unavoidable when the hard photons were down-Comptonized to softer photons. To determine the details of the leakage effect and unveil the nature of SLSNe, more high-quality bolometric light curves and spectra of SLSNe are required

  7. Influence of container structures and content solutions on dispensing time of ophthalmic solutions

    Directory of Open Access Journals (Sweden)

    Keiji Yoshikawa

    2010-05-01

    Full Text Available Keiji Yoshikawa1, Hiroshi Yamada21Yoshikawa Eye Clinic, Tokyo, Japan; 2Santen Pharmaceutical Co., Ltd., Osaka, JapanPurpose: To investigate the influence of container structures and content solutions on the time of dispensing from eye dropper bottles.Methods: Eye dropper bottle models, solution models (filtrate water/surfactant solution and a dispensing time measuring apparatus were prepared to measure the dispensing time.Results: With filtrate water and pressure thrust load of 0.3 MPa, the dispensing time significantly increased from 1.1 ± 0.5 seconds to 4.6 ± 1.1 seconds depending on the decrease of inner aperture diameters from 0.4 mm to 0.2 mm (P < 0.0001. When using the bottle models with inner aperture diameters of 0.4 mm or larger, the dispensing time became constant. The dispensing time using surfactant solution showed the same tendency as above. When pressure thrust load was large (0.07 MPa, the solution flew out continuously with inner aperture diameters of 0.4 mm or larger and the dispensing time could not be measured. The inner aperture diameter most strongly explained the variation of the dispensing time in both the content solutions in the multiple linear regression analysis (filtrate water: 46%, R2 = 0.462, surfactant solution: 56%, R2 = 0.563.Conclusions: Among content solutions and container structures, the dispensing time was mostly influenced by the diameter of the inner aperture of bottles.Keywords: dispensing time, model eye dropper bottle, model ophthalmic solution, nozzle internal space volume, nozzle inner aperture diameter

  8. Unifying inflation with late-time acceleration by a BIonic system

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Rahaman, Farook, E-mail: rahaman@iucaa.ernet.in [Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal (India); Setare, Mohammad Reza, E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Pradhan, Anirudh, E-mail: pradhan@iucaa.ernet.in [Department of Mathematics, Institute of Applied Sciences & Humanities, GLA University, Mathura-281 406, U.P. (India); Capozziello, Salvatore, E-mail: capozziello@na.infn.it [Dipartimento di Fisica, Universitá di Napoli “Federico II”, I-80126 Napoli (Italy); INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Edificio G, I-80126 Napoli (Italy); Gran Sasso Science Institute (INFN), Viale F. Crispi, 7, I-67100 L' Aquila (Italy); Sardar, Iftikar Hossain, E-mail: iftikar.spm@gmail.com [Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal (India)

    2015-07-30

    We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations.

  9. Unifying inflation with late-time acceleration by a BIonic system

    Directory of Open Access Journals (Sweden)

    Alireza Sepehri

    2015-07-01

    Full Text Available We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations.

  10. Unifying inflation with late-time acceleration by a BIonic system

    International Nuclear Information System (INIS)

    Sepehri, Alireza; Rahaman, Farook; Setare, Mohammad Reza; Pradhan, Anirudh; Capozziello, Salvatore; Sardar, Iftikar Hossain

    2015-01-01

    We propose a cosmological model that unifies inflation, deceleration and acceleration phases of expansion history by a BIonic system. At the beginning, there are k black fundamental strings that transited to the BIon configuration at a given corresponding point. Here, two coupled universes, brane and antibrane, are created interacting each other through a wormhole and inflate. With decreasing temperature, the energy of this wormhole flows into the universe branes and leads to inflation. After a short time, the wormhole evaporates, the inflation ends and a deceleration epoch starts. By approaching the brane and antibrane universes together, a tachyon is born, grows and causes the creation of a new wormhole. At this time, the brane and antibrane universes result connected again and the late-time acceleration era of the universe begins. We compare our model with previous unified phantom models and observational data obtaining some cosmological parameters like temperature in terms of time. We also find that deceleration parameter is negative during inflation and late-time acceleration epochs, while it is positive during the deceleration era. This means that the model is consistent, in principle, with cosmological observations

  11. Numerical investigation of the late-time Kerr tails

    Energy Technology Data Exchange (ETDEWEB)

    Racz, Istvan; Toth, Gabor Zs, E-mail: iracz@rmki.kfki.hu, E-mail: tgzs@rmki.kfki.hu [RMKI, H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary)

    2011-10-07

    The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I{sup +} are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I{sup +}. The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.

  12. Numerical investigation of the late-time Kerr tails

    International Nuclear Information System (INIS)

    Racz, Istvan; Toth, Gabor Zs

    2011-01-01

    The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I + are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I + . The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.

  13. Characteristics of late-time striations observed during operation stress

    International Nuclear Information System (INIS)

    Wolcott, J.H.; Simons, D.J.; Eastman, T.E.; Fitzgerald, T.J.

    1978-01-01

    Some results are presented on an experiment in progress of data analysis for a study of the actual satellite communication links through structured barium plasma clouds intended to simulate many aspects of the highly disturbed, post-nuclear-explosion upper atmosphere and the investigation of the late time spatial decay of plasma striations, or filaments, imbedded within the barium ion cloud

  14. Progressive Red Shifts in the Late-Time Spectra of Type Ia Supernovae

    Science.gov (United States)

    Black, Christine; Fesen, Robert; Parrent, Jerod

    2017-01-01

    We examine the evolution of late-time, optical nebular features of Type Ia supernovae (SNe Ia) using a sample consisting of 160 spectra of 27 normal SNe Ia taken from the literature as well as unpublished spectra of SN 2008Q and ASASSN-14lp. Particular attention is given to nebular features between 4000-6000 Ang in terms of temporal changes in width and central wavelength. Analysis of the prominent late-time 4700 Ang feature shows a progressive central wavelength shift from ˜4600 Ang to longer wavelengths out to at least day +300 for our entire sample. We find no evidence for the feature’s red-ward shift slowing or halting at an [Fe III] blend centroid ˜4700 Ang as has been proposed. Two weaker adjacent features at around 4850 and 5000 Ang exhibit similar red shifts to that of the 4700 Ang feature. We conclude that the ubiquitous red shift of these common late-time SN Ia spectral features is not mainly due to a decrease in line velocities of forbidden Fe emissions, but the result of decreasing line velocities and opacity of permitted Fe absorption lines.

  15. Late-time cosmological approach in mimetic f(R, T) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Baffou, E.H. [Institut de Mathematiques et de Sciences Physiques (IMSP), Porto-Novo (Benin); Houndjo, M.J.S. [Institut de Mathematiques et de Sciences Physiques (IMSP), Porto-Novo (Benin); Faculte des Sciences et Techniques de Natitingou, Natitingou (Benin); Hamani-Daouda, M. [Universite de Niamey, Departement de Physique, Niamey (Niger); Alvarenga, F.G. [Universidade Federal do Espirito Santo, Departamento de Engenharia e Ciencias Naturais, CEUNES, Sao Mateus, ES (Brazil)

    2017-10-15

    In this paper, we investigate the late-time cosmic acceleration in mimetic f(R, T) gravity with the Lagrange multiplier and potential in a Universe containing, besides radiation and dark energy, a self-interacting (collisional) matter. We obtain through the modified Friedmann equations the main equation that can describe the cosmological evolution. Then, with several models from Q(z) and the well-known particular model f(R, T), we perform an analysis of the late-time evolution. We examine the behavior of the Hubble parameter, the dark energy equation of state and the total effective equation of state and in each case we compare the resulting picture with the non-collisional matter (assumed as dust) and also with the collisional matter in mimetic f(R, T) gravity. The results obtained are in good agreement with the observational data and show that in the presence of the collisional matter the dark energy oscillations in mimetic f(R, T) gravity can be damped. (orig.)

  16. Is Travel Time to Colonoscopy Associated With Late-Stage Colorectal Cancer Among Medicare Beneficiaries in Iowa?

    Science.gov (United States)

    Charlton, Mary E; Matthews, Kevin A; Gaglioti, Anne; Bay, Camden; McDowell, Bradley D; Ward, Marcia M; Levy, Barcey T

    2016-09-01

    Colorectal cancer (CRC) screening has been shown to decrease the incidence of late-stage colorectal cancer, yet a substantial proportion of Americans do not receive screening. Those in rural areas may face barriers to colonoscopy services based on travel time, and previous studies have demonstrated lower screening among rural residents. Our purpose was to assess factors associated with late-stage CRC, and specifically to determine if longer travel time to colonoscopy was associated with late-stage CRC among an insured population in Iowa. SEER-Medicare data were used to identify individuals ages 65 to 84 years old diagnosed with CRC in Iowa from 2002 to 2009. The distance between the centroid of the ZIP code of residence and the ZIP code of colonoscopy was computed for each individual who had continuous Medicare fee-for-service coverage for a 3- to 4-month period prior to diagnosis, and a professional claim for colonoscopy within that time frame. Demographic characteristics and travel times were compared between those diagnosed with early- versus late-stage CRC. Also, demographic differences between those who had colonoscopy claims identified within 3-4 months prior to diagnosis (81%) were compared to patients with no colonoscopy claims identified (19%). A total of 5,792 subjects met inclusion criteria; 31% were diagnosed with early-stage versus 69% with late-stage CRC. Those divorced or widowed (vs married) were more likely to be diagnosed with late-stage CRC (OR: 1.20, 95% CI: 1.06-1.37). Travel time was not associated with diagnosis of late-stage CRC. Among a Medicare-insured population, there was no relationship between travel time to colonoscopy and disease stage at diagnosis. It is likely that factors other than distance to colonoscopy present more pertinent barriers to screening in this insured population. Additional research should be done to determine reasons for nonadherence to screening among those with access to CRC screening services, given that over

  17. Chameleon field and the late time acceleration of the Universe

    Indian Academy of Sciences (India)

    Chameleon field and the late time acceleration of the Universe. NARAYAN BANERJEE1,∗, SUDIPTA DAS2 and KOYEL GANGULY3. 1IISER-Kolkata, Mohanpur Campus, P.O. BCKV Main Office, District Nadia 741 252,. India. 2Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019, India.

  18. Late-time acceleration with steep exponential potentials

    Energy Technology Data Exchange (ETDEWEB)

    Shahalam, M. [Zhejiang University of Technology, Institute for Advanced Physics and Mathematics, Hangzhou (China); Yang, Weiqiang [Liaoning Normal University, Department of Physics, Dalian (China); Myrzakulov, R. [Eurasian National University, Department of General and Theoretical Physics, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Wang, Anzhong [Zhejiang University of Technology, Institute for Advanced Physics and Mathematics, Hangzhou (China); Baylor University, GCAP-CASPER, Department of Physics, Waco, TX (United States)

    2017-12-15

    In this letter, we study the cosmological dynamics of steeper potential than exponential. Our analysis shows that a simple extension of an exponential potential allows to capture late-time cosmic acceleration and retain the tracker behavior. We also perform statefinder and Om diagnostics to distinguish dark energy models among themselves and with ΛCDM. In addition, to put the observational constraints on the model parameters, we modify the publicly available CosmoMC code and use an integrated data base of baryon acoustic oscillation, latest Type Ia supernova from Joint Light Curves sample and the local Hubble constant value measured by the Hubble Space Telescope. (orig.)

  19. Late-time acceleration with steep exponential potentials

    International Nuclear Information System (INIS)

    Shahalam, M.; Yang, Weiqiang; Myrzakulov, R.; Wang, Anzhong

    2017-01-01

    In this letter, we study the cosmological dynamics of steeper potential than exponential. Our analysis shows that a simple extension of an exponential potential allows to capture late-time cosmic acceleration and retain the tracker behavior. We also perform statefinder and Om diagnostics to distinguish dark energy models among themselves and with ΛCDM. In addition, to put the observational constraints on the model parameters, we modify the publicly available CosmoMC code and use an integrated data base of baryon acoustic oscillation, latest Type Ia supernova from Joint Light Curves sample and the local Hubble constant value measured by the Hubble Space Telescope. (orig.)

  20. Late-time particle emission from laser-produced graphite plasma

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, S. S.; Hassanein, A.; Polek, M. [School of Nuclear Engineering, Center for Materials Under Extreme Environment, Purdue University, West Lafayette, Indiana 47907 (United States)

    2011-09-01

    We report a late-time ''fireworks-like'' particle emission from laser-produced graphite plasma during its evolution. Plasmas were produced using graphite targets excited with 1064 nm Nd: yttrium aluminum garnet (YAG) laser in vacuum. The time evolution of graphite plasma was investigated using fast gated imaging and visible emission spectroscopy. The emission dynamics of plasma is rapidly changing with time and the delayed firework-like emission from the graphite target followed a black-body curve. Our studies indicated that such firework-like emission is strongly depended on target material properties and explained due to material spallation caused by overheating the trapped gases through thermal diffusion along the layer structures of graphite.

  1. Late-time particle emission from laser-produced graphite plasma

    International Nuclear Information System (INIS)

    Harilal, S. S.; Hassanein, A.; Polek, M.

    2011-01-01

    We report a late-time ''fireworks-like'' particle emission from laser-produced graphite plasma during its evolution. Plasmas were produced using graphite targets excited with 1064 nm Nd: yttrium aluminum garnet (YAG) laser in vacuum. The time evolution of graphite plasma was investigated using fast gated imaging and visible emission spectroscopy. The emission dynamics of plasma is rapidly changing with time and the delayed firework-like emission from the graphite target followed a black-body curve. Our studies indicated that such firework-like emission is strongly depended on target material properties and explained due to material spallation caused by overheating the trapped gases through thermal diffusion along the layer structures of graphite.

  2. Borges' ‘late style’: literature, memory and time

    Directory of Open Access Journals (Sweden)

    Adriana Mancini

    2017-12-01

    Full Text Available Using the concept of ‘late style’ established by Adorno (1993 in his analysis of the last quartets of Beethoven and adopted up by Said (2006, we consider the mature Borges’s essays on time and immortality and his exploration of the themes of The Double and insomnia in his fictional works Stories of the Book of Sand and poem The Cipher. We analyse some key characteristics of Borges’s style – coincidences and dissidences – and compare them to those proposed by Adorno for artistic production in later years.

  3. Late washing filter cleaning cycle demonstration

    International Nuclear Information System (INIS)

    Meyer, M.L.; McCabe, D.J.

    1992-01-01

    The DWPF Late Washing Facility will filter cesium and potassium tetraphenyl borate (TPB) solids using a Mott sintered metal filter, identical to the filter now used in the In-tank Precipitation Facility. The purpose of the late wash step is primarily to remove the nitrite salts from the slurry prior to delivery to DWPF. Periodic chemical cleaning of the filter will be required, presumably after each batch although the actual required frequency could not be determined on the lab-scale. Minimization of chemical cleaning solution volumes is key to maximizing the attainment of the Late Wash facility. This report summarizes work completed in experiments designed to identify minimum cleaning solution requirements

  4. Semianalytic Solution of Space-Time Fractional Diffusion Equation

    Directory of Open Access Journals (Sweden)

    A. Elsaid

    2016-01-01

    Full Text Available We study the space-time fractional diffusion equation with spatial Riesz-Feller fractional derivative and Caputo fractional time derivative. The continuation of the solution of this fractional equation to the solution of the corresponding integer order equation is proved. The series solution of this problem is obtained via the optimal homotopy analysis method (OHAM. Numerical simulations are presented to validate the method and to show the effect of changing the fractional derivative parameters on the solution behavior.

  5. The impact of acquisition time of planar cardiac 123I-MIBG imaging on the late heart to mediastinum ratio

    International Nuclear Information System (INIS)

    Dimitriu-Leen, Aukelien C.; Veltman, Caroline E.; Bax, Jeroen J.; Scholte, Arthur J.H.A.; Gimelli, Alessia; Al Younis, Imad; Verberne, Hein J.; Wolterbeek, Ron; Zandbergen-Harlaar, Silvia

    2016-01-01

    The aim of this study was to investigate whether performing the late cardiac 123 I-metaiodobenzylguanidine (MIBG) scan earlier than 4 h post-injection (p.i.) has relevant impact on the late heart to mediastinum ratio (H/M ratio) in patients with heart failure (HF). Forty-nine patients with HF (median left ventricular ejection fraction of 31 %, 51 % ischaemic HF) referred for cardiac 123 I-MIBG scintigraphy were scanned at 15 min (early) p.i. and at 1, 2, 3 and 4 h (late) p.i. of 123 I-MIBG. Late H/M ratios were calculated and evaluated using a linear mixed model with the mean late H/M ratio at 4 h p.i. as a reference. A difference in late H/M ratios of more than 0.10 between the different acquisition times in comparison with the late H/M ratio at 4 h p.i. was considered as clinically relevant. Statistically significant mean differences were observed between the late H/M ratios at 1, 2 and 3 h p.i. compared with the late H/M ratio at 4 h p.i. (0.09, 0.05 and 0.02, respectively). However, the mean differences did not exceed the cut-off value of 0.10. On an individual patient level, compared to the late H/M ratio at 4 h p.i., the late H/M ratios at 1, 2 and 3 h p.i. differed more than 0.10 in 24 (50 %), 9 (19 %) and 2 (4 %) patients, respectively. Variation in acquisition time of 123 I-MIBG between 2 and 4 h p.i. does not lead to a clinically significant change in the late H/M ratio. An earlier acquisition time seems to be justified and may warrant a more time-efficient cardiac 123 I-MIBG imaging protocol. (orig.)

  6. Travelling wave solutions for some time-delayed equations through factorizations

    International Nuclear Information System (INIS)

    Fahmy, E.S.

    2008-01-01

    In this work, we use factorization method to find explicit particular travelling wave solutions for the following important nonlinear second-order partial differential equations: The generalized time-delayed Burgers-Huxley, time-delayed convective Fishers, and the generalized time-delayed Burgers-Fisher. Using the particular solutions for these equations we find the general solutions, two-parameter solution, as special cases

  7. Merged Real Time GNSS Solutions for the READI System

    Science.gov (United States)

    Santillan, V. M.; Geng, J.

    2014-12-01

    Real-time measurements from increasingly dense Global Navigational Satellite Systems (GNSS) networks located throughout the western US offer a substantial, albeit largely untapped, contribution towards the mitigation of seismic and other natural hazards. Analyzed continuously in real-time, currently over 600 instruments blanket the San Andreas and Cascadia fault systems of the North American plate boundary and can provide on-the-fly characterization of transient ground displacements highly complementary to traditional seismic strong-motion monitoring. However, the utility of GNSS systems depends on their resolution, and merged solutions of two or more independent estimation strategies have been shown to offer lower scatter and higher resolution. Towards this end, independent real time GNSS solutions produced by Scripps Inst. of Oceanography and Central Washington University (PANGA) are now being formally combined in pursuit of NASA's Real-Time Earthquake Analysis for Disaster Mitigation (READI) positioning goals. CWU produces precise point positioning (PPP) solutions while SIO produces ambiguity resolved PPP solutions (PPP-AR). The PPP-AR solutions have a ~5 mm RMS scatter in the horizontal and ~10mm in the vertical, however PPP-AR solutions can take tens of minutes to re-converge in case of data gaps. The PPP solutions produced by CWU use pre-cleaned data in which biases are estimated as non-integer ambiguities prior to formal positioning with GIPSY 6.2 using a real time stream editor developed at CWU. These solutions show ~20mm RMS scatter in the horizontal and ~50mm RMS scatter in the vertical but re-converge within 2 min. or less following cycle-slips or data outages. We have implemented the formal combination of the CWU and SCRIPPS ENU displacements using the independent solutions as input measurements to a simple 3-element state Kalman filter plus white noise. We are now merging solutions from 90 stations, including 30 in Cascadia, 39 in the Bay Area, and 21

  8. Involvement of DNA polymerase δ in DNA repair synthesis in human fibroblasts at late times after ultraviolet irradiation

    International Nuclear Information System (INIS)

    Dresler, S.L.; Gowans, B.J.; Robinson-Hill, R.M.; Hunting, D.J.

    1988-01-01

    DNA repair synthesis following UV irradiation of confluent human fibroblasts has a biphasic time course with an early phase of rapid nucleotide incorporation and a late phase of much slower nucleotide incorporation. The biphasic nature of this curve suggests that two distinct DNA repair systems may be operative. Previous studies have specifically implicated DNA polymerase δ as the enzyme involved in DNA repair synthesis occurring immediately after UV damage. In this paper, the authors describe studies of DNA polymerase involvement in DNA repair synthesis in confluent human fibroblasts at late times after UV irradiation. Late UV-induced DNA repair synthesis in both intact and permeable cells was found to be inhibited by aphidicolin, indicating the involvement of one of the aphidicolin-sensitive DNA polymerases, α or δ. In permeable cells, the process was further analyzed by using the nucleotide analogue (butylphenyl)-2'-deoxyguanosine 5'-triphosphate, which inhibits DNA polymerase α several hundred times more strongly than it inhibits DNA polymerase δ. The (butylphenyl)-2'-deoxyguanosine 5'-triphosphate inhibition curve for late UV-induced repair synthesis was very similar to that for polymerase δ. It appears that repair synthesis at late time after UV irradiation, like repair synthesis at early times, is mediated by DNA polymerase δ

  9. A late time accelerated FRW model with scalar and vector fields via Noether symmetry

    Directory of Open Access Journals (Sweden)

    Babak Vakili

    2014-11-01

    Full Text Available We study the evolution of a three-dimensional minisuperspace cosmological model by the Noether symmetry approach. The phase space variables turn out to correspond to the scale factor of a flat Friedmann–Robertson–Walker (FRW model, a scalar field with potential function V(ϕ with which the gravity part of the action is minimally coupled and a vector field of its kinetic energy is coupled with the scalar field by a coupling function f(ϕ. Then, the Noether symmetry of such a cosmological model is investigated by utilizing the behavior of the corresponding Lagrangian under the infinitesimal generator of the desired symmetry. We explicitly calculate the form of the coupling function between the scalar and the vector fields and also the scalar field potential function for which such symmetry exists. Finally, by means of the corresponding Noether current, we integrate the equations of motion and obtain exact solutions for the scale factor, scalar and vector fields. It is shown that the resulting cosmology is an accelerated expansion universe for which its expansion is due to the presence of the vector field in the early times, while the scalar field is responsible of its late time expansion. Keywords: Noether symmetry, Scalar field cosmology, Vector field cosmology

  10. Imprints of explosion conditions on late-time spectra of type Ia supernovae

    Science.gov (United States)

    Diamond, Tiara R.

    Type Ia supernovae (SNe Ia) play a vital role in the discrimination of different cosmological models. These events have been shown to be standardizable based on properties of their light curves during the early-time photospheric phase. However, the distribution of types of progenitor system, the explosion trigger, and the physics of the explosion are still an active topic of discussion. The details of the progenitors and explosion may provide insight into the variation seen in Type Ia supernova light curves and spectra, and therefore, allow for additional methods of standardization among the group. Late-time near-infrared spectral observations for SNe Ia show numerous strong emission features of forbidden line transitions of cobalt and iron, tracing the central distribution of iron-group burning products. As the spectrum ages, the cobalt features fade as expected from the decay of 56Co to 56Fe. This work will show that the strong and isolated [Fe II] emission line at 1.644 mum provides a unique tool to analyze near-infrared spectra of SNe Ia. Several new methods of analysis will be demonstrated to determine some of the initial conditions of the system. The initial central density, rhoc, and the extent of mixing in the central regions of the explosion have signatures in the line profiles of late-time spectra. An embedded magnetic field, B, of the white dwarf can be determined using the evolution of the lines profiles. Currently magnetic field effects are not included in the hydrodynamics and radiation transport of simulations of SNe Ia. Normalization of spectra to the 1.644 mum line allows separation of features produced by stable versus unstable isotopes of iron group elements. Implications for potential progenitor systems, explosion mechanisms, and the origins and morphology of magnetic fields in SNe Ia, in addition to limitations of the method, are discussed. Observations of the late-time near-infrared emission spectrum at multiple epochs allow for the first ever

  11. Decoupling of stream and vegetation solutes during the late stages of weathering: insights from elemental and Mg isotope trends at the Luquillo Critical Zone Observatory, Puerto Rico

    Science.gov (United States)

    Chapela Lara, M.; Schuessler, J. A.; Buss, H. L.; McDowell, W. H.

    2017-12-01

    During the evolution of the critical zone, the predominant source of nutrients to the vegetation changes from bedrock weathering to atmospheric inputs and biological recycling. In parallel, the architecture of the critical zone changes with time, promoting a change in water flow regime from near-surface porous flow during early weathering stages to more complex flow regimes modulated by clay-rich regolith during the late stages of weathering. As a consequence of these two concurrent processes, we can expect the predominant sources and pathways of solutes to the streams to also change during critical zone evolution. If this is true, we would observe a decoupling between the solutes used by the vegetation and those that determine the composition of the streams during the late stages of weathering, represented by geomorphically stable tropical settings. To test these hypotheses, we are analyzing the elemental and Mg isotopic composition of regolith and streams at the humid tropical Luquillo Critical Zone Observatory. We aim to trace the relative contributions of the surficial, biologically mediated pathways and the deeper, weathering controlled nutrient pathways. We also investigate the role of lithology on the solute decoupling between the vegetation and the stream, by examining two similar headwater catchments draining two different bedrocks (andesitic volcaniclastic and granitic). Our preliminary elemental and Mg isotope results are consistent with atmospheric inputs in the upper 2 m of regolith in both lithologies and with bedrock weathering at depth. During a short storm event ( 6 h), a headwater stream draining volcaniclastic bedrock showed a large variation in Mg and δ26Mg, correlated with total suspended solids, while another similar headwater granitic stream showed a much narrower variation. A larger stream draining volcaniclastic bedrock showed changes in Mg concentration in response to rain during the same storm event, but did not change in δ26Mg

  12. Time-Dependent Toroidal Compactification Proposals and the Bianchi Type I Model: Classical and Quantum Solutions

    Directory of Open Access Journals (Sweden)

    L. Toledo Sesma

    2016-01-01

    Full Text Available We construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. This approach is applied to anisotropic cosmological Bianchi type I model for which we study the classical coupling of the anisotropic scale factors with the two real scalar moduli produced by the compactification process. Under this approach, we present an isotropization mechanism for the Bianchi I cosmological model through the analysis of the ratio between the anisotropic parameters and the volume of the Universe which in general keeps constant or runs into zero for late times. We also find that the presence of extra dimensions in this model can accelerate the isotropization process depending on the momenta moduli values. Finally, we present some solutions to the corresponding Wheeler-DeWitt (WDW equation in the context of standard quantum cosmology.

  13. Non-Perturbative Formulation of Time-Dependent String Solutions

    CERN Document Server

    Alexandre, J; Mavromatos, Nikolaos E; Alexandre, Jean; Ellis, John; Mavromatos, Nikolaos E.

    2006-01-01

    We formulate here a new world-sheet renormalization-group technique for the bosonic string, which is non-perturbative in the Regge slope alpha' and based on a functional method for controlling the quantum fluctuations, whose magnitudes are scaled by the value of alpha'. Using this technique we exhibit, in addition to the well-known linear-dilaton cosmology, a new, non-perturbative time-dependent background solution. Using the reparametrization invariance of the string S-matrix, we demonstrate that this solution is conformally invariant to alpha', and we give a heuristic inductive argument that conformal invariance can be maintained to all orders in alpha'. This new time-dependent string solution may be applicable to primordial cosmology or to the exit from linear-dilaton cosmology at large times.

  14. Relative timing of last glacial maximum and late-glacial events in the central tropical Andes

    Science.gov (United States)

    Bromley, Gordon R. M.; Schaefer, Joerg M.; Winckler, Gisela; Hall, Brenda L.; Todd, Claire E.; Rademaker, Kurt M.

    2009-11-01

    Whether or not tropical climate fluctuated in synchrony with global events during the Late Pleistocene is a key problem in climate research. However, the timing of past climate changes in the tropics remains controversial, with a number of recent studies reporting that tropical ice age climate is out of phase with global events. Here, we present geomorphic evidence and an in-situ cosmogenic 3He surface-exposure chronology from Nevado Coropuna, southern Peru, showing that glaciers underwent at least two significant advances during the Late Pleistocene prior to Holocene warming. Comparison of our glacial-geomorphic map at Nevado Coropuna to mid-latitude reconstructions yields a striking similarity between Last Glacial Maximum (LGM) and Late-Glacial sequences in tropical and temperate regions. Exposure ages constraining the maximum and end of the older advance at Nevado Coropuna range between 24.5 and 25.3 ka, and between 16.7 and 21.1 ka, respectively, depending on the cosmogenic production rate scaling model used. Similarly, the mean age of the younger event ranges from 10 to 13 ka. This implies that (1) the LGM and the onset of deglaciation in southern Peru occurred no earlier than at higher latitudes and (2) that a significant Late-Glacial event occurred, most likely prior to the Holocene, coherent with the glacial record from mid and high latitudes. The time elapsed between the end of the LGM and the Late-Glacial event at Nevado Coropuna is independent of scaling model and matches the period between the LGM termination and Late-Glacial reversal in classic mid-latitude records, suggesting that these events in both tropical and temperate regions were in phase.

  15. Time-periodic solutions of the Benjamin-Ono equation

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose , D.M.; Wilkening, Jon

    2008-04-01

    We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.

  16. Time-periodic solutions of the Benjamin-Ono equation

    International Nuclear Information System (INIS)

    Ambrose, D.M.; Wilkening, Jon

    2008-01-01

    We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations

  17. Maximum Lateness Scheduling on Two-Person Cooperative Games with Variable Processing Times and Common Due Date

    OpenAIRE

    Liu, Peng; Wang, Xiaoli

    2017-01-01

    A new maximum lateness scheduling model in which both cooperative games and variable processing times exist simultaneously is considered in this paper. The job variable processing time is described by an increasing or a decreasing function dependent on the position of a job in the sequence. Two persons have to cooperate in order to process a set of jobs. Each of them has a single machine and their processing cost is defined as the minimum value of maximum lateness. All jobs have a common due ...

  18. Comparison of finite-difference and variational solutions to advection-diffusion problems

    International Nuclear Information System (INIS)

    Lee, C.E.; Washington, K.E.

    1984-01-01

    Two numerical solution methods are developed for 1-D time-dependent advection-diffusion problems on infinite and finite domains. Numerical solutions are compared with analytical results for constant coefficients and various boundary conditions. A finite-difference spectrum method is solved exactly in time for periodic boundary conditions by a matrix operator method and exhibits excellent accuracy compared with other methods, especially at late times, where it is also computationally more efficient. Finite-system solutions are determined from a conservational variational principle with cubic spatial trial functions and solved in time by a matrix operator method. Comparisons of problems with few nodes show excellent agreement with analytical solutions and exhibit the necessity of implementing Lagrangian conservational constraints for physically-correct solutions. (author)

  19. Solution of Moving Boundary Space-Time Fractional Burger’s Equation

    Directory of Open Access Journals (Sweden)

    E. A.-B. Abdel-Salam

    2014-01-01

    Full Text Available The fractional Riccati expansion method is used to solve fractional differential equations with variable coefficients. To illustrate the effectiveness of the method, the moving boundary space-time fractional Burger’s equation is studied. The obtained solutions include generalized trigonometric and hyperbolic function solutions. Among these solutions, some are found for the first time. The linear and periodic moving boundaries for the kink solution of the Burger’s equation are presented graphically and discussed.

  20. Predictors of Timely Prenatal Care Initiation and Adequate Utilization in a Sample of Late Adolescent Texas Latinas.

    Science.gov (United States)

    Torres, Rosamar; Kehoe, Priscilla; Heilemann, MarySue V

    2018-03-01

    Little is known of late adolescent Texas Latinas' prenatal care perceptions or how these perceptions predict timely prenatal care initiation or adequate utilization. Hence, the purpose of this study is to describe and compare these perceptions between participants with timely versus late prenatal care initiation and adequate, intermediate, and inadequate prenatal care utilization; and to determine predictors of timely prenatal care initiation and adequate utilization. Fifty-four postpartum Latinas were recruited through social media. Eligibility criteria were 18 to 21 years old, Texas-born, primiparous, uncomplicated pregnancy/delivery, and English literate. Prenatal care perceptions were measured with the Revised Better Babies Survey and Access Barriers to Care Index. Participants had favorable views of prenatal care benefits; however, not living with the baby's father predicted inadequate prenatal care, Wald χ 2 (1) = 4.93, p = .026. Perceived benefits of timely and adequate prenatal care predicted timely prenatal care initiation, χ 2 (1) = 7.47, p = .006. Self-reported depression during pregnancy predicted timely entry into prenatal care, χ 2 (1) = 4.73, p = .03. Participants' positive prenatal care perceptions did not predict adequate prenatal care utilization, indicating that barriers serve as powerful obstacles in late adolescent Texas Latinas.

  1. Aging, Disablement, and Dying: Using Time-as-Process and Time-as-Resources Metrics to Chart Late-Life Change.

    Science.gov (United States)

    Ram, Nilam; Gerstorf, Denis; Fauth, Elizabeth; Zarit, Steven; Malmberg, Bo

    2010-01-01

    Time is a vehicle that can be used to represent aging-related processes and to index the amount of aging-related resources or burdens individuals have accumulated. Using data on cognitive (memory) performance from two Swedish studies of the elderly (OCTO and OCTO-TWIN), we illustrate how time-as-process and time-as-resources/burdens time metrics can be articulated and incorporated within a growth curve modeling framework. Our results highlight the possibilities for representing the contributions of primary, secondary, and tertiary aspects of aging to late-life changes in cognitive and other domains of functioning.

  2. Solution to the monoenergetic time-dependent neutron transport equation with a time-varying source

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    1986-01-01

    Even though fundamental time-dependent neutron transport problems have existed since the inception of neutron transport theory, it has only been recently that a reliable numerical solution to one of the basic problems has been obtained. Experience in generating numerical solutions to time-dependent transport equations has indicated that the multiple collision formulation is the most versatile numerical technique for model problems. The formulation coupled with a moment reconstruction of each collided flux component has led to benchmark-quality (four- to five-digit accuracy) numerical evaluation of the neutron flux in plane infinite geometry for any degree of scattering anisotropy and for both pulsed isotropic and beam sources. As will be shown in this presentation, this solution can serve as a Green's function, thus extending the previous results to more complicated source situations. Here we will be concerned with a time-varying source at the center of an infinite medium. If accurate, such solutions have both pedagogical and practical uses as benchmarks against which other more approximate solutions designed for a wider class of problems can be compared

  3. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction

    Science.gov (United States)

    Zapartas, E.; de Mink, S. E.; Izzard, R. G.; Yoon, S.-C.; Badenes, C.; Götberg, Y.; de Koter, A.; Neijssel, C. J.; Renzo, M.; Schootemeijer, A.; Shrotriya, T. S.

    2017-05-01

    Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, %, of core-collapse supernovae are "late", that is, they occur 50-200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4-8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by % because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star - white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution.

  4. Time-dependent coupled harmonic oscillators: classical and quantum solutions

    International Nuclear Information System (INIS)

    Macedo, D.X.; Guedes, I.

    2014-01-01

    In this work we present the classical and quantum solutions for an arbitrary system of time-dependent coupled harmonic oscillators, where the masses (m), frequencies (ω) and coupling parameter (k) are functions of time. To obtain the classical solutions, we use a coordinate and momentum transformations along with a canonical transformation to write the original Hamiltonian as the sum of two Hamiltonians of uncoupled harmonic oscillators with modified time-dependent frequencies and unitary masses. To obtain the exact quantum solutions we use a unitary transformation and the Lewis and Riesenfeld (LR) invariant method. The exact wave functions are obtained by solving the respective Milne–Pinney (MP) equation for each system. We obtain the solutions for the system with m 1 = m 2 = m 0 e γt , ω 1 = ω 01 e -γt/2 , ω 2 = ω 02 e -γt/2 and k = k 0 . (author)

  5. Cosmological solutions and finite time singularities in Finslerian geometry

    Science.gov (United States)

    Paul, Nupur; de, S. S.; Rahaman, Farook

    2018-03-01

    We consider a very general scenario of our universe where its geometry is characterized by the Finslerian structure on the underlying spacetime manifold, a generalization of the Riemannian geometry. Now considering a general energy-momentum tensor for matter sector, we derive the gravitational field equations in such spacetime. Further, to depict the cosmological dynamics in such spacetime proposing an interesting equation of state identified by a sole parameter γ which for isotropic limit is simply the barotropic equation of state p = (γ ‑ 1)ρ (γ ∈ ℝ being the barotropic index), we solve the background dynamics. The dynamics offers several possibilities depending on this sole parameter as follows: (i) only an exponential expansion, or (ii) a finite time past singularity (big bang) with late accelerating phase, or (iii) a nonsingular universe exhibiting an accelerating scenario at late time which finally predicts a big rip type singularity. We also discuss several energy conditions and the possibility of cosmic bounce. Finally, we establish the first law of thermodynamics in such spacetime.

  6. Bulk viscosity, interaction and the viability of phantom solutions

    Energy Technology Data Exchange (ETDEWEB)

    Leyva, Yoelsy; Sepulveda, Mirko [Universidad de Tarapaca, Departamento de Fisica, Facultad de Ciencias, Arica (Chile)

    2017-06-15

    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) Universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with w < -1. From the different cases that we study, the only possible scenario, with bulk viscosity and interaction term, belongs to the quintessence region. In the latter case, we find bounds on the interaction parameter compatible with latest observational data. (orig.)

  7. Stationary solution of a time dependent density matrix formalism

    International Nuclear Information System (INIS)

    Tohyama, Mitsuru

    1994-01-01

    A stationary solution of a time-dependent density-matrix formalism, which is an extension of the time-dependent Hartree-Fock theory to include the effects of two-body correlations, is obtained for the Lipkin model hamiltonian, using an adiabatic treatment of the two-body interaction. It is found that the obtained result is a reasonable approximation for the exact solution of the model. (author)

  8. Closed form solutions of two time fractional nonlinear wave equations

    Directory of Open Access Journals (Sweden)

    M. Ali Akbar

    2018-06-01

    Full Text Available In this article, we investigate the exact traveling wave solutions of two nonlinear time fractional wave equations. The fractional derivatives are described in the sense of conformable fractional derivatives. In addition, the traveling wave solutions are accomplished in the form of hyperbolic, trigonometric, and rational functions involving free parameters. To investigate such types of solutions, we implement the new generalized (G′/G-expansion method. The extracted solutions are reliable, useful and suitable to comprehend the optimal control problems, chaotic vibrations, global and local bifurcations and resonances, furthermore, fission and fusion phenomena occur in solitons, the relativistic energy-momentum relation, scalar electrodynamics, quantum relativistic one-particle theory, electromagnetic interactions etc. The results reveal that the method is very fruitful and convenient for exploring nonlinear differential equations of fractional order treated in theoretical physics. Keywords: Traveling wave solution, Soliton, Generalized (G′/G-expansion method, Time fractional Duffing equation, Time fractional Riccati equation

  9. Too hot to handle? Analytic solutions for massive neutrino or warm dark matter cosmologies

    Science.gov (United States)

    Slepian, Zachary; Portillo, Stephen K. N.

    2018-05-01

    We obtain novel closed-form solutions to the Friedmann equation for cosmological models containing a component whose equation of state is that of radiation (w = 1/3) at early times and that of cold pressureless matter (w = 0) at late times. The equation of state smoothly transitions from the early to late-time behavior and exactly describes the evolution of a species with a Dirac Delta function distribution in momentum magnitudes |p_0| (i.e. all particles have the same |p_0|). Such a component, here termed "hot matter", is an approximate model for both neutrinos and warm dark matter. We consider it alone and in combination with cold matter and with radiation, also obtaining closed-form solutions for the growth of super-horizon perturbations in each case. The idealized model recovers t(a) to better than 1.5% accuracy for all a relative to a Fermi-Dirac distribution (as describes neutrinos). We conclude by adding the second moment of the distribution to our exact solution and then generalizing to include all moments of an arbitrary momentum distribution in a closed-form solution.

  10. Why are they late? Timing abilities and executive control among students with learning disabilities.

    Science.gov (United States)

    Grinblat, Nufar; Rosenblum, Sara

    2016-12-01

    While a deficient ability to perform daily tasks on time has been reported among students with learning disabilities (LD), the underlying mechanism behind their 'being late' is still unclear. This study aimed to evaluate the organization in time, time estimation abilities, actual performance time pertaining to specific daily activities, as well as the executive functions of students with LD in comparison to those of controls, and to assess the relationships between these domains among each group. The participants were 27 students with LD, aged 20-30, and 32 gender and age-matched controls who completed the Time Organization and Participation Scale (TOPS) and the Behavioral Rating Inventory of Executive Function-Adult version (BRIEF-A). In addition, their ability to estimate the time needed to complete the task of preparing a cup of coffee as well as their actual performance time were evaluated. The results indicated that in comparison to controls, students with LD showed significantly inferior organization in time (TOPS) and executive function abilities (BRIEF-A). Furthermore, their time estimation abilities were significantly inferior and they required significantly more time to prepare a cup of coffee. Regression analysis identified the variables that predicted organization in time and task performance time among each group. The significance of the results for both theoretical and clinical implications are discussed. What this paper adds? This study examines the underlying mechanism of the phenomena of being late among students with LD. Following a recent call for using ecologically valid assessments, the functional daily ability of students with LD to prepare a cup of coffee and to organize time were investigated. Furthermore, their time estimation and executive control abilities were examined as a possible underlying mechanism for their lateness. Although previous studies have indicated executive control deficits among students with LD, to our knowledge, this

  11. A parametric LTR solution for discrete-time systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Jannerup, Ole Erik

    1989-01-01

    A parametric LTR (loop transfer recovery) solution for discrete-time compensators incorporating filtering observers which achieve exact recovery is presented for both minimum- and non-minimum-phase systems. First the recovery error, which defines the difference between the target loop transfer...... and the full loop transfer function, is manipulated into a general form involving the target loop transfer matrix and the fundamental recovery matrix. A parametric LTR solution based on the recovery matrix is developed. It is shown that the LQR/LTR (linear quadratic Gaussian/loop transfer recovery) solution...

  12. Simple cosmological model with inflation and late times acceleration

    Science.gov (United States)

    Szydłowski, Marek; Stachowski, Aleksander

    2018-03-01

    In the framework of polynomial Palatini cosmology, we investigate a simple cosmological homogeneous and isotropic model with matter in the Einstein frame. We show that in this model during cosmic evolution, early inflation appears and the accelerating phase of the expansion for the late times. In this frame we obtain the Friedmann equation with matter and dark energy in the form of a scalar field with a potential whose form is determined in a covariant way by the Ricci scalar of the FRW metric. The energy density of matter and dark energy are also parameterized through the Ricci scalar. Early inflation is obtained only for an infinitesimally small fraction of energy density of matter. Between the matter and dark energy, there exists an interaction because the dark energy is decaying. For the characterization of inflation we calculate the slow roll parameters and the constant roll parameter in terms of the Ricci scalar. We have found a characteristic behavior of the time dependence of density of dark energy on the cosmic time following the logistic-like curve which interpolates two almost constant value phases. From the required numbers of N-folds we have found a bound on the model parameter.

  13. Time course of late rectal- and urinary bladder side effects after MRI-guided adaptive brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Georg, P.; Georg, D.; Poetter, R.; Doerr, W. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Medical University Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology; Medical University Vienna/ AKH Wien (Austria). Comprehensive Cancer Centre; Boni, A.; Ghabuous, A. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Goldner, G.; Schmid, M.P. [Medical University Vienna/ AKH Wien (Austria). Dept. of Radiooncology; Medical University Vienna/ AKH Wien (Austria). Comprehensive Cancer Centre

    2013-07-15

    Background and purpose: To analyze the time course of late rectal- and urinary bladder complications after brachytherapy for cervical cancer and to compare the incidence- and prevalence rates thereof. Patients and methods: A total of 225 patients were treated with external-beam radiotherapy (EBRT) and magnetic resonance imaging (MRI)-guided brachytherapy with or without chemotherapy. Late side effects were assessed prospectively using the Late Effects in Normal Tissue - Subjective, Objective, Management and Analytic (LENT/SOMA) scale. The parameters analyzed were time to onset, duration, actuarial incidence- (occurrence of new side effects during a defined time period) and prevalence rates (side effects existing at a defined time point). Results: Median follow-up was 44 months. Side effects (grade 1-4) in rectum and bladder were present in 31 and 49 patients, 14 and 27 months (mean time to onset) after treatment, respectively. All rectal and 76 % of bladder side effects occurred within 3 years after radiotherapy. Mean duration of rectal events was 19 months; 81 % resolved within 3 years of their initial diagnosis. Mean duration of bladder side effects was 20 months; 61 % resolved within 3 years. The 3- and 5-year actuarial complication rates were 16 and 19 % in rectum and 18 and 28 % in bladder, respectively. The corresponding prevalence rates were 9 and 2 % (rectum) and 18 and 21 % (bladder), respectively. Conclusion: Late side effects after cervical cancer radiotherapy are partially reversible, but their time course is organ-dependent. The combined presentation of incidence- and prevalence rates provides the most comprehensive information. (orig.)

  14. Time course of late rectal- and urinary bladder side effects after MRI-guided adaptive brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Georg, P.; Georg, D.; Poetter, R.; Doerr, W.; Medical University Vienna; Medical University Vienna/ AKH Wien; Boni, A.; Ghabuous, A.; Goldner, G.; Schmid, M.P.; Medical University Vienna/ AKH Wien

    2013-01-01

    Background and purpose: To analyze the time course of late rectal- and urinary bladder complications after brachytherapy for cervical cancer and to compare the incidence- and prevalence rates thereof. Patients and methods: A total of 225 patients were treated with external-beam radiotherapy (EBRT) and magnetic resonance imaging (MRI)-guided brachytherapy with or without chemotherapy. Late side effects were assessed prospectively using the Late Effects in Normal Tissue - Subjective, Objective, Management and Analytic (LENT/SOMA) scale. The parameters analyzed were time to onset, duration, actuarial incidence- (occurrence of new side effects during a defined time period) and prevalence rates (side effects existing at a defined time point). Results: Median follow-up was 44 months. Side effects (grade 1-4) in rectum and bladder were present in 31 and 49 patients, 14 and 27 months (mean time to onset) after treatment, respectively. All rectal and 76 % of bladder side effects occurred within 3 years after radiotherapy. Mean duration of rectal events was 19 months; 81 % resolved within 3 years of their initial diagnosis. Mean duration of bladder side effects was 20 months; 61 % resolved within 3 years. The 3- and 5-year actuarial complication rates were 16 and 19 % in rectum and 18 and 28 % in bladder, respectively. The corresponding prevalence rates were 9 and 2 % (rectum) and 18 and 21 % (bladder), respectively. Conclusion: Late side effects after cervical cancer radiotherapy are partially reversible, but their time course is organ-dependent. The combined presentation of incidence- and prevalence rates provides the most comprehensive information. (orig.)

  15. Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

    International Nuclear Information System (INIS)

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-01-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems.

  16. Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

    Science.gov (United States)

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-01-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems. PMID:27877486

  17. From analytical solutions of solute transport equations to multidimensional time-domain random walk (TDRW) algorithms

    Science.gov (United States)

    Bodin, Jacques

    2015-03-01

    In this study, new multi-dimensional time-domain random walk (TDRW) algorithms are derived from approximate one-dimensional (1-D), two-dimensional (2-D), and three-dimensional (3-D) analytical solutions of the advection-dispersion equation and from exact 1-D, 2-D, and 3-D analytical solutions of the pure-diffusion equation. These algorithms enable the calculation of both the time required for a particle to travel a specified distance in a homogeneous medium and the mass recovery at the observation point, which may be incomplete due to 2-D or 3-D transverse dispersion or diffusion. The method is extended to heterogeneous media, represented as a piecewise collection of homogeneous media. The particle motion is then decomposed along a series of intermediate checkpoints located on the medium interface boundaries. The accuracy of the multi-dimensional TDRW method is verified against (i) exact analytical solutions of solute transport in homogeneous media and (ii) finite-difference simulations in a synthetic 2-D heterogeneous medium of simple geometry. The results demonstrate that the method is ideally suited to purely diffusive transport and to advection-dispersion transport problems dominated by advection. Conversely, the method is not recommended for highly dispersive transport problems because the accuracy of the advection-dispersion TDRW algorithms degrades rapidly for a low Péclet number, consistent with the accuracy limit of the approximate analytical solutions. The proposed approach provides a unified methodology for deriving multi-dimensional time-domain particle equations and may be applicable to other mathematical transport models, provided that appropriate analytical solutions are available.

  18. A multi scale approximation solution for the time dependent Boltzmann-transport equation

    International Nuclear Information System (INIS)

    Merk, B.

    2004-03-01

    The basis of all transient simulations for nuclear reactor cores is the reliable calculation of the power production. The local power distribution is generally calculated by solving the space, time, energy and angle dependent neutron transport equation known as Boltzmann equation. The computation of exact solutions of the Boltzmann equation is very time consuming. For practical numerical simulations approximated solutions are usually unavoidable. The objective of this work is development of an effective multi scale approximation solution for the Boltzmann equation. Most of the existing methods are based on separation of space and time. The new suggested method is performed without space-time separation. This effective approximation solution is developed on the basis of an expansion for the time derivative of different approximations to the Boltzmann equation. The method of multiple scale expansion is used for the expansion of the time derivative, because the problem of the stiff time behaviour can't be expressed by standard expansion methods. This multiple scale expansion is used in this work to develop approximation solutions for different approximations of the Boltzmann equation, starting from the expansion of the point kinetics equations. The resulting analytic functions are used for testing the applicability and accuracy of the multiple scale expansion method for an approximation solution with 2 delayed neutron groups. The results are tested versus the exact analytical results for the point kinetics equations. Very good agreement between both solutions is obtained. The validity of the solution with 2 delayed neutron groups to approximate the behaviour of the system with 6 delayed neutron groups is demonstrated in an additional analysis. A strategy for a solution with 4 delayed neutron groups is described. A multiple scale expansion is performed for the space-time dependent diffusion equation for one homogenized cell with 2 delayed neutron groups. The result is

  19. Solution-based synthesis and design of late transition metal chalcogenide materials for oxygen reduction reaction (ORR).

    Science.gov (United States)

    Gao, Min-Rui; Jiang, Jun; Yu, Shu-Hong

    2012-01-09

    Late transition metal chalcogenide (LTMC) nanomaterials have been introduced as a promising Pt-free oxygen reduction reaction (ORR) electrocatalysts because of their low cost, good ORR activity, high methanol tolerance, and facile synthesis. Herein, an overview on the design and synthesis of LTMC nanomaterials by solution-based strategies is presented along with their ORR performances. Current solution-based synthetic approaches towards LTMC nanomaterials include a hydrothermal/solvothermal approach, single-source precursor approach, hot-injection approach, template-directed soft synthesis, and Kirkendall-effect-induced soft synthesis. Although the ORR activity and stability of LTMC nanomaterials are still far from what is needed for practical fuel-cell applications, much enhanced electrocatalytic performance can be expected. Recent advances have emphasized that decorating the surface of the LTMC nanostructures with other functional nanoparticles can lead to much better ORR catalytic activity. It is believed that new synthesis approaches to LTMCs, modification techniques of LTMCs, and LTMCs with desirable morphology, size, composition, and structures are expected to be developed in the future to satisfy the requirements of commercial fuel cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Experimental study of some homeostatic parameters at late times after exposure to radiation

    International Nuclear Information System (INIS)

    Chertkov, K.S.; Andrianova, I.E.; Atamanova, O.M.; Filimonova, G.I.; Nesterova, T.A.; Sbitneva, M.F.; Glushkov, V.A.; Chotij, V.G.; Stejmatskaya, Z.A.

    1994-01-01

    Following radiation damage from LD 50 - LD 97 , changes in blood, immune and endocrine parameters were revealed and followed up in dogs at the time of late effects development, 3-18 months after exposure. The changes result from post-radiation immunodeficiency and resemble those observed in residents of radioactive contaminate areas or in men participated in Chernobyl accident amelioration

  1. Exact solutions of space-time fractional EW and modified EW equations

    International Nuclear Information System (INIS)

    Korkmaz, Alper

    2017-01-01

    The bright soliton solutions and singular solutions are constructed for the space-time fractional EW and the space-time fractional modified EW (MEW) equations. Both equations are reduced to ordinary differential equations by the use of fractional complex transform (FCT) and properties of modified Riemann–Liouville derivative. Then, various ansatz method are implemented to construct the solutions for both equations.

  2. On the late-time behavior of Virasoro blocks and a classification of semiclassical saddles

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, A. Liam [Department of Physics, Boston University,Commonwealth Avenue, Boston, MA 02215 (United States); Kaplan, Jared [Department of Physics and Astronomy, Johns Hopkins University,Charles Street, Baltimore, MD 21218 (United States)

    2017-04-12

    Recent work has demonstrated that black hole thermodynamics and information loss/restoration in AdS{sub 3}/CFT{sub 2} can be derived almost entirely from the behavior of the Virasoro conformal blocks at large central charge, with relatively little dependence on the precise details of the CFT spectrum or OPE coefficients. Here, we elaborate on the non-perturbative behavior of Virasoro blocks by classifying all ‘saddles’ that can contribute for arbitrary values of external and internal operator dimensions in the semiclassical large central charge limit. The leading saddles, which determine the naive semiclassical behavior of the Virasoro blocks, all decay exponentially at late times, and at a rate that is independent of internal operator dimensions. Consequently, the semiclassical contribution of a finite number of high-energy states cannot resolve a well-known version of the information loss problem in AdS{sub 3}. However, we identify two infinite classes of sub-leading saddles, and one of these classes does not decay at late times.

  3. Revisiting the Fundamental Analytical Solutions of Heat and Mass Transfer: The Kernel of Multirate and Multidimensional Diffusion

    Science.gov (United States)

    Zhou, Quanlin; Oldenburg, Curtis M.; Rutqvist, Jonny; Birkholzer, Jens T.

    2017-11-01

    There are two types of analytical solutions of temperature/concentration in and heat/mass transfer through boundaries of regularly shaped 1-D, 2-D, and 3-D blocks. These infinite-series solutions with either error functions or exponentials exhibit highly irregular but complementary convergence at different dimensionless times, td. In this paper, approximate solutions were developed by combining the error-function-series solutions for early times and the exponential-series solutions for late times and by using time partitioning at the switchover time, td0. The combined solutions contain either the leading term of both series for normal-accuracy approximations (with less than 0.003 relative error) or the first two terms for high-accuracy approximations (with less than 10-7 relative error) for 1-D isotropic (spheres, cylinders, slabs) and 2-D/3-D rectangular blocks (squares, cubes, rectangles, and rectangular parallelepipeds). This rapid and uniform convergence for rectangular blocks was achieved by employing the same time partitioning with individual dimensionless times for different directions and the product of their combined 1-D slab solutions. The switchover dimensionless time was determined to minimize the maximum approximation errors. Furthermore, the analytical solutions of first-order heat/mass flux for 2-D/3-D rectangular blocks were derived for normal-accuracy approximations. These flux equations contain the early-time solution with a three-term polynomial in √td and the late-time solution with the limited-term exponentials for rectangular blocks. The heat/mass flux equations and the combined temperature/concentration solutions form the ultimate kernel for fast simulations of multirate and multidimensional heat/mass transfer in porous/fractured media with millions of low-permeability blocks of varying shapes and sizes.

  4. The precise time-dependent solution of the Fokker–Planck equation with anomalous diffusion

    International Nuclear Information System (INIS)

    Guo, Ran; Du, Jiulin

    2015-01-01

    We study the time behavior of the Fokker–Planck equation in Zwanzig’s rule (the backward-Ito’s rule) based on the Langevin equation of Brownian motion with an anomalous diffusion in a complex medium. The diffusion coefficient is a function in momentum space and follows a generalized fluctuation–dissipation relation. We obtain the precise time-dependent analytical solution of the Fokker–Planck equation and at long time the solution approaches to a stationary power-law distribution in nonextensive statistics. As a test, numerically we have demonstrated the accuracy and validity of the time-dependent solution. - Highlights: • The precise time-dependent solution of the Fokker–Planck equation with anomalous diffusion is found. • The anomalous diffusion satisfies a generalized fluctuation–dissipation relation. • At long time the time-dependent solution approaches to a power-law distribution in nonextensive statistics. • Numerically we have demonstrated the accuracy and validity of the time-dependent solution

  5. The precise time-dependent solution of the Fokker–Planck equation with anomalous diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ran; Du, Jiulin, E-mail: jiulindu@aliyun.com

    2015-08-15

    We study the time behavior of the Fokker–Planck equation in Zwanzig’s rule (the backward-Ito’s rule) based on the Langevin equation of Brownian motion with an anomalous diffusion in a complex medium. The diffusion coefficient is a function in momentum space and follows a generalized fluctuation–dissipation relation. We obtain the precise time-dependent analytical solution of the Fokker–Planck equation and at long time the solution approaches to a stationary power-law distribution in nonextensive statistics. As a test, numerically we have demonstrated the accuracy and validity of the time-dependent solution. - Highlights: • The precise time-dependent solution of the Fokker–Planck equation with anomalous diffusion is found. • The anomalous diffusion satisfies a generalized fluctuation–dissipation relation. • At long time the time-dependent solution approaches to a power-law distribution in nonextensive statistics. • Numerically we have demonstrated the accuracy and validity of the time-dependent solution.

  6. A Practical Solution for Time Synchronization in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    COCA, E.

    2012-11-01

    Full Text Available Time synchronization in wireless sensor node networks is a hot topic. Many papers present various software algorithms and hardware solutions to keep accurate time information on mobile nodes. In terms of real life applications wireless sensor nodes are preferred in many domains, starting with simple room monitoring and finishing with pipeline surveillance projects. Positioning applications are far more restrictive on timekeeping accuracy, as for the velocity of nodes calculations precise time or time difference values are needed. The accuracy of time information on nodes has to be always correlated with the application requirements. In this paper, we present some considerations regarding time synchronization linked with specific needs for individual practical applications. A practical low energy method of time keeping at node level is proposed and tested. The performances of the proposed solution in terms of short and long term stability and energy requirements are analyzed and compared with existing solutions. Simulation and experimental results, some advantages and disadvantages of the method are presented at the end of the paper.

  7. An Exact Solution of the Gamma Ray Burst Arrival Time Analysis ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    An Exact Solution of the Gamma Ray Burst Arrival Time Analysis. Problem. S. Sinha ISRO Satellite Center, Bangalore 560 017, India. Abstract. An analytical solution of the GRB arrival time analysis is presented. The errors in the position of the GRB resulting from timing and position errors of different satellites are calculated.

  8. The time-dependent development of electric double-layers in saline solutions

    International Nuclear Information System (INIS)

    Morrow, R; McKenzie, D R; Bilek, M M M

    2006-01-01

    We have studied the time-dependent development of electric double-layers (ionic sheaths) in saline solutions by simultaneously solving the sodium and chlorine ion continuity equations coupled with Poisson's equation in one dimension. The study of the effects of time-varying electric fields in solution is relevant to the possible health effect of radio-frequency electric fields on cells in the human body and to assessing the potential of using external electric fields to orient proteins for attachment to surfaces for biosensing applications. Our calculations, for applied voltages of 10-175 mV between the electrode and the solution, predict time scales of ∼0.1-110 μs for the formation of double-layers in solutions of concentration between 0.001 and 1.0 M. We develop an empirical equation that can predict the double-layer formation time to within 10% over this wide parameter range. The method has been validated by comparing the solutions obtained, once the program has run to a steady state, with the standard non-linear Poisson-Boltzmann equations. Excellent agreement is found with the Gouy-Chapman solution of the non-linear Poisson-Boltzmann equation. Thus the method is not restricted in accuracy and applicability as is the case for the linear Poisson-Boltzmann equation. The method can also provide solutions for cases where there are orders of magnitude changes in the ion densities; this has not been the case for previous studies where small perturbation analysis has been employed. The method developed here can readily be extended to two and three dimensions using time-splitting methods

  9. Similarity Solutions for Multiterm Time-Fractional Diffusion Equation

    OpenAIRE

    Elsaid, A.; Abdel Latif, M. S.; Maneea, M.

    2016-01-01

    Similarity method is employed to solve multiterm time-fractional diffusion equation. The orders of the fractional derivatives belong to the interval (0,1] and are defined in the Caputo sense. We illustrate how the problem is reduced from a multiterm two-variable fractional partial differential equation to a multiterm ordinary fractional differential equation. Power series solution is obtained for the resulting ordinary problem and the convergence of the series solution is discussed. Based on ...

  10. Short-time existence of solutions for mean-field games with congestion

    KAUST Repository

    Gomes, Diogo A.

    2015-11-20

    We consider time-dependent mean-field games with congestion that are given by a Hamilton–Jacobi equation coupled with a Fokker–Planck equation. These models are motivated by crowd dynamics in which agents have difficulty moving in high-density areas. The congestion effects make the Hamilton–Jacobi equation singular. The uniqueness of solutions for this problem is well understood; however, the existence of classical solutions was only known in very special cases, stationary problems with quadratic Hamiltonians and some time-dependent explicit examples. Here, we demonstrate the short-time existence of C∞ solutions for sub-quadratic Hamiltonians.

  11. Static and time-dependent solutions of Einstein-Maxwell-Yukawa fields

    International Nuclear Information System (INIS)

    Lal, K.B.; Khan, M.Q.

    1977-01-01

    An exact solution of Einstein-Maxwell-Yukawa field equations has been obtained in a space-time with a static metric. A critical analysis reveals that the results previously obtained by Patel (Tensor New Sci.; 29:237 (1975)), Singh (Gen. Rel. Grav.; 6:657 (1974)), and Taub (Ann. Math.; 53:472 (1951)) are particular cases of the present solution. The singular behaviour of the solution is also discussed in this paper. Further, extending the technique developed by Janis et al (Phys. Rev.; 186:1729 (1969)), for static fields, to the case of nonstatic fields, an exact time-dependent axially symmetric solution of EMY fields has been obtained. The present solution in the nonstatic case is nonsingular in the sense of Bonnor (J. Math. Mech.; 6:203 (1957)) and presents a generalization of the results obtained by Misra (Proc. Cambridge Philos. Soc.; 58:711 (1962)) to the case when a zero-mass scalar field coexists with a source free electromagnetic field. (author)

  12. Analytic solutions of the multigroup space-time reactor kinetics equations

    International Nuclear Information System (INIS)

    Lee, C.E.; Rottler, S.

    1986-01-01

    The development of analytical and numerical solutions to the reactor kinetics equations is reviewed. Analytic solutions of the multigroup space-time reactor kinetics equations are developed for bare and reflected slabs and spherical reactors for zero flux, zero current and extrapolated endpoint boundary conditions. The material properties of the reactors are assumed constant in space and time, but spatially-dependent source terms and initial conditions are investigated. The system of partial differential equations is reduced to a set of linear ordinary differential equations by the Laplace transform method. These equations are solved by matrix Green's functions yielding a general matrix solution for the neutron flux and precursor concentration in the Laplace transform space. The detailed pole structure of the Laplace transform matrix solutions is investigated. The temporally- and spatially-dependent solutions are determined from the inverse Laplace transform using the Cauchy residue theorem, the theorem of Frobenius, a knowledge of the detailed pole structure and matrix operators. (author)

  13. Primordial inhomogeneities in the expanding universe. II - General features of spherical models at late times

    Science.gov (United States)

    Olson, D. W.; Silk, J.

    1979-01-01

    This paper studies the density profile that forms around a spherically symmetric bound central core immersed in a homogeneous-background k = 0 or k = -1 Friedmann-Robertson-Walker cosmological model, with zero pressure. Although the density profile in the linearized regime is almost arbitrary, in the nonlinear regime certain universal features of the density profile are obtained that are independent of the details of the initial conditions. The formation of 'halos' ('holes') with densities greater than (less than) the average cosmological density is discussed. It is shown that in most regions 'halos' form, and universal values are obtained for the slope of the ln (density)-ln (radius) profile in those 'halos' at late times, independently of the shape of the initial density profile. Restrictions are derived on where it is possible for 'holes' to exist at late times and on how such 'holes' must have evolved.

  14. The late-time development of the Richtmyer-Meshkov instability

    International Nuclear Information System (INIS)

    Prasad, J. K.; Rasheed, A.; Kumar, S.; Sturtevant, B.

    2000-01-01

    Measurements have been made of the growth by the Richtmyer-Meshkov instability of nominally single-scale perturbations on an air/sulfur hexafluoride (SF 6 ) interface in a large shock tube. An approximately sinusoidal shape is given to the interface by a wire mesh which supports a polymeric membrane separating the air from the SF 6 . A single shock wave incident on the interface induces motion by the baroclinic mechanism of vorticity generation. The visual thickness δ of the interface is measured from schlieren photographs obtained singly in each run and in high-speed motion pictures. Data are presented for δ at times considerably larger than previously reported, and they are tested for self-similarity including independence of initial conditions. Four different initial amplitude/wavelength combinations at one incident shock strength are used to determine the scaling of the data. It is found that the growth rate decreases rapidly with time, dδ/dt∝t -p (i.e., δ∝t 1-p ), where 0.67(less-or-similar sign)p(less-or-similar sign)0.74 and that a small dependence on the initial wavelength λ 0 persists to large time. The larger value of the power law exponent agrees with the result of the late-time-decay similarity law of Huang and Leonard [Phys. Fluids 6, 3765-3775 (1994)]. The influence of the wire mesh and membrane on the mixing process is assessed. (c) 2000 American Institute of Physics

  15. Solutions to Time-Fractional Diffusion-Wave Equation in Cylindrical Coordinates

    Directory of Open Access Journals (Sweden)

    Povstenko YZ

    2011-01-01

    Full Text Available Nonaxisymmetric solutions to time-fractional diffusion-wave equation with a source term in cylindrical coordinates are obtained for an infinite medium. The solutions are found using the Laplace transform with respect to time , the Hankel transform with respect to the radial coordinate , the finite Fourier transform with respect to the angular coordinate , and the exponential Fourier transform with respect to the spatial coordinate . Numerical results are illustrated graphically.

  16. Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada

    Science.gov (United States)

    Longstaffe, Fred J.; Zazula, Grant

    2018-01-01

    A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0–1 ‰) in δ13C of modern Yukon grasses. A major change (~2–10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time. PMID:29447202

  17. Phantom solution in a non-linear Israel-Stewart theory

    Science.gov (United States)

    Cruz, Miguel; Cruz, Norman; Lepe, Samuel

    2017-06-01

    In this paper we present a phantom solution with a big rip singularity in a non-linear regime of the Israel-Stewart formalism. In this framework it is possible to extend this causal formalism in order to describe accelerated expansion, where assumption of near equilibrium is no longer valid. We assume a flat universe filled with a single viscous fluid ruled by a barotropic EoS, p = ωρ, which can represent a late time accelerated phase of the cosmic evolution. The solution allows to cross the phantom divide without evoking an exotic matter fluid and the effective EoS parameter is always lesser than -1 and constant in time.

  18. Translation invariant time-dependent solutions to massive gravity II

    Science.gov (United States)

    Mourad, J.; Steer, D. A.

    2014-06-01

    This paper is a sequel to JCAP 12 (2013) 004 and is also devoted to translation-invariant solutions of ghost-free massive gravity in its moving frame formulation. Here we consider a mass term which is linear in the vielbein (corresponding to a β3 term in the 4D metric formulation) in addition to the cosmological constant. We determine explicitly the constraints, and from the initial value formulation show that the time-dependent solutions can have singularities at a finite time. Although the constraints give, as in the β1 case, the correct number of degrees of freedom for a massive spin two field, we show that the lapse function can change sign at a finite time causing a singular time evolution. This is very different to the β1 case where time evolution is always well defined. We conclude that the β3 mass term can be pathological and should be treated with care.

  19. The Causes of Late Coming among High School Students in Soshanguve, Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    Simeon Maile

    2017-12-01

    Full Text Available Late coming to school has become a major problem in many schools, particularly township schools with serious consequences. Current research has demonstrated that many schools in South Africa are performing badly due to inefficient use of the teaching and learning time. In this article, we argue that while major administrative interventions are undertaken to improve the quality of learning and teaching, it seems that very little attention is paid to late-coming. Late-coming has become a cancer that saps away big interventions and strays the performance of selected township schools in a different direction. The purpose of this research is to investigate the causes of late-coming among high school students in selected secondary schools of Shoshanguve. A qualitative approach was used to draw data from high school students in selected secondary schools of Shoshanguve. The findings reveal that late-coming is common among learners in selected secondary schools of Shoshanguve. It happens every day for varying reasons. We recommended practical solutions ranging from administrative improvement to learner behavioural change.

  20. Anisotropic, time-dependent solutions in maximally Gauss-Bonnet extended gravity

    International Nuclear Information System (INIS)

    Kitaura, Takayuki; Wheeler, J.T.

    1991-01-01

    In an arbitrary number of dimensions, we find the full exact anisotropic, time-dependent, diagonal-metric solutions to maximally Gauss-Bonnet extended gravity theory. This class of theories for which the lagrangian is an arbitrary linear combination of dimensionally extnded Euler forms, is the most general gravitational theory in which the field equations contain no more than second derivatives of the metric. We show that the space-time exponentially approaches an asymptotic state of constant, anisotropic curvature and prove three theorems concerning two generic types of singularities. The first theorem gives conditions for the existence of Kasner-like curvature singularities. For these the metric diverges as tsup(p i ) where Σp i = 2 k max -1 and k max is the highest power of the curvature in the lagrangian. Other critical point singularities can arise from the polynomial nature of the theory. The remaining theorems demonstrate that the generic solution is extendible at all of these other critical points and that the generic critical points occur at moments of extremal volume density of space-time. We give an explicit coordinate transformation which produces a smooth extension through the critical point. The space-time may therefore alternately expand and contract for many cycles before expanding forever or contracting to a singularity. Many particular cases are treated in detail including several power series solutions, the generalized Kasner solution to general relativity with or without cosmological constant, the perturbative solution for quadratic string gravity, and five-dimensional extended gravity. (orig.)

  1. Isometries of half supersymmetric time-like solutions in five dimensions

    International Nuclear Information System (INIS)

    Gutowski, J B; Sabra, W A

    2010-01-01

    Spinorial geometry techniques have recently been used to classify all half supersymmetric solutions in gauged five-dimensional supergravity with vector multiplets. In this paper we consider solutions for which at least one of the Killing spinors generates a time-like Killing vector. We obtain coordinate transformations which considerably simplify the solutions, and in a number of cases, we obtain explicitly some additional Killing vectors which were hidden in the original analysis.

  2. Travelling Solitary Wave Solutions for Generalized Time-delayed Burgers-Fisher Equation

    International Nuclear Information System (INIS)

    Deng Xijun; Han Libo; Li Xi

    2009-01-01

    In this paper, travelling wave solutions for the generalized time-delayed Burgers-Fisher equation are studied. By using the first-integral method, which is based on the ring theory of commutative algebra, we obtain a class of travelling solitary wave solutions for the generalized time-delayed Burgers-Fisher equation. A minor error in the previous article is clarified. (general)

  3. Similarity Solutions for Multiterm Time-Fractional Diffusion Equation

    Directory of Open Access Journals (Sweden)

    A. Elsaid

    2016-01-01

    Full Text Available Similarity method is employed to solve multiterm time-fractional diffusion equation. The orders of the fractional derivatives belong to the interval (0,1] and are defined in the Caputo sense. We illustrate how the problem is reduced from a multiterm two-variable fractional partial differential equation to a multiterm ordinary fractional differential equation. Power series solution is obtained for the resulting ordinary problem and the convergence of the series solution is discussed. Based on the obtained results, we propose a definition for a multiterm error function with generalized coefficients.

  4. Explicit solution of Calderon preconditioned time domain integral equations

    KAUST Repository

    Ulku, Huseyin Arda; Bagci, Hakan; Michielssen, Eric

    2013-01-01

    operators and a PE(CE)m type linear multistep to march on in time. Unlike its implicit counterpart, the proposed explicit solver requires the solution of an MOT system with a Gram matrix that is sparse and well-conditioned independent of the time step size

  5. Early and late humoral rejection: a clinicopathologic entity in two times.

    Science.gov (United States)

    Péfaur, J; Díaz, P; Panace, R; Salinas, P; Fiabane, A; Quinteros, N; Chea, R; Naranjo, E; Wurgaft, A; Beltran, E; Elgueta, S; Wegmann, M E; Gajardo, J G; Contreras, L

    2008-11-01

    Humoral rejection is an important cause of early and late graft loss. The late variant is difficult to diagnose and treat. There is a close correlation between sclerosing nephropathy and anti-HLA antibodies. We analyzed 113 renal allograft recipients between August 2004 and April 2007. Acute humoral rejection was defined as acute graft dysfunction in presence of donor-specific antibodies (DSA) detected by flow panel reactive antibodies (PRA) and/or C4d positive pericapilary tubules (PTC) detected histopathologically by immunofluorescent or immunoperoxidase at less than 3 months postransplantation. Late humoral rejection was defined as dysfunction occurring after 3 months postransplantation with histopathologic glomerulopathy or vasculopathy and positive C4d PTC. We included all patients who were diagnosed with early or late graft dysfunction and underwent biopsy, all of which were examined for C4d. Four patients had acute humoral rejection treated with IVIG or plasmapheresis. The patient and graft survivals were 100% and serum creatinine averaged 1.7 mg/dL. Three recipients experienced late humoral rejection at 3 to 10 years posttransplantation All received high-dose IVIG; one also was treated with thymoglobulin. Immunosuppression was switched to tacrolimus, mycophenolate mofetil, and steroids. Only one patient recovered renal function; the others returned to dialysis. Among seven patients only one had an actual PRA (>20%) and three showed 10% to 20%. However, six had a positive historical PRA of 10% to 50%. In conclusion, Recognition of acute humoral rejection has contributed to graft rescue by controlling alloantibody production through new specific immunosuppressive therapies in contrast with the clinical response to acute therapy, treatment of a chronic entity has shown poor outcomes, probably because antibody mediated chronic graft damage is already present when the late diagnosis is established by biopsy.

  6. Global profiling of DNA replication timing and efficiency reveals that efficient replication/firing occurs late during S-phase in S. pombe.

    Directory of Open Access Journals (Sweden)

    Majid Eshaghi

    Full Text Available BACKGROUND: During S. pombe S-phase, initiation of DNA replication occurs at multiple sites (origins that are enriched with AT-rich sequences, at various times. Current studies of genome-wide DNA replication profiles have focused on the DNA replication timing and origin location. However, the replication and/or firing efficiency of the individual origins on the genomic scale remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: Using the genome-wide ORF-specific DNA microarray analysis, we show that in S. pombe, individual origins fire with varying efficiencies and at different times during S-phase. The increase in DNA copy number plotted as a function of time is approximated to the near-sigmoidal model, when considering the replication start and end timings at individual loci in cells released from HU-arrest. Replication efficiencies differ from origin to origin, depending on the origin's firing efficiency. We have found that DNA replication is inefficient early in S-phase, due to inefficient firing at origins. Efficient replication occurs later, attributed to efficient but late-firing origins. Furthermore, profiles of replication timing in cds1Delta cells are abnormal, due to the failure in resuming replication at the collapsed forks. The majority of the inefficient origins, but not the efficient ones, are found to fire in cds1Delta cells after HU removal, owing to the firing at the remaining unused (inefficient origins during HU treatment. CONCLUSIONS/SIGNIFICANCE: Taken together, our results indicate that efficient DNA replication/firing occurs late in S-phase progression in cells after HU removal, due to efficient late-firing origins. Additionally, checkpoint kinase Cds1p is required for maintaining the efficient replication/firing late in S-phase. We further propose that efficient late-firing origins are essential for ensuring completion of DNA duplication by the end of S-phase.

  7. A global cyclostratigraphic framework constrains the timing and pacing of environmental changes over the Late Devonian (Frasnian - Famennian) mass extinction

    Science.gov (United States)

    De Vleeschouwer, David; Da Silva, Anne-Christine; Day, James E.; Whalen, Michael; Claeys, Philippe

    2016-04-01

    Milankovitch cycles (obliquity, eccentricity and precession) result in changes in the distribution of solar energy over seasons, as well as over latitudes, on time scales of ten thousands of years to millions of years. These changing patterns in insolation have induced significant variations in Earth's past climate over the last 4.5 billion years. Cyclostratigraphy and astrochronology utilize the geologic imprint of such quasi-cyclic climatic variations to measure geologic time. In recent years, major improvements of the Geologic Time Scale have been proposed through the application of cyclostratigraphy, mostly for the Mesozoic and Cenozoic (Gradstein et al., 2012). However, the field of Paleozoic cyclostratigraphy and astrochronology is still in its infancy and the application of cyclostratigraphic techniques in the Paleozoic allows for a whole new range of research questions. For example, unraveling the timing and pacing of environmental changes over the Late Devonian mass extinction on a 105-year time-scale concerns such a novel research question. Here, we present a global cyclostratigraphic framework for late Frasnian to early Famennian climatic and environmental change, through the integration of globally distributed sections. The backbone of this relative time scale consists of previously published cyclostratigraphies for western Canada and Poland (De Vleeschouwer et al., 2012; De Vleeschouwer et al., 2013). We elaborate this Euramerican base by integrating new proxy data -interpreted in terms of astronomical climate forcing- from the Iowa basin (USA, magnetic susceptibility and carbon isotope data) and Belgium (XRF and carbon isotope data). Next, we expand this well-established cyclostratigraphic framework towards the Paleo-Tethys Ocean, using magnetic susceptibility and carbon isotope records from the Fuhe section in South China (Whalen et al., 2015). The resulting global cyclostratigraphic framework implies an important refinement of the late Frasnian to

  8. Flow time analysis of load management late arrival discrete time queueing system with dual service rate using hypo geometrical distribution

    International Nuclear Information System (INIS)

    Shah, S.A.; Shah, W.; Shaikh, F.K.

    2012-01-01

    Flow time analysis is a powerful concept to analyze the flow time of any arriving customer in any system at any instant. A load management mechanism can be employed very effectively in any queueing system by utilizing a system which provides probability of dual service rate. In this paper, we develop and demonstrate the flow and service processes transition diagram to determine the flow time of a customer in a load management late arrival state dependent finite discrete time queueing system with dual service rate where customers are hypo geometrically distributed. We compute the probability mass function of each starting state and total probability mass function. The obtained analytical results are validated with simulation results for varying values of arrival and service probabilities. (author)

  9. Path integral solution for some time-dependent potential

    International Nuclear Information System (INIS)

    Storchak, S.N.

    1989-12-01

    The quantum-mechanical problem with a time-dependent potential is solved by the path integral method. The solution is obtained by the application of the previously derived general formula for rheonomic homogeneous point transformation and reparametrization in the path integral. (author). 4 refs

  10. Job shop scheduling problem with late work criterion

    Science.gov (United States)

    Piroozfard, Hamed; Wong, Kuan Yew

    2015-05-01

    Scheduling is considered as a key task in many industries, such as project based scheduling, crew scheduling, flight scheduling, machine scheduling, etc. In the machine scheduling area, the job shop scheduling problems are considered to be important and highly complex, in which they are characterized as NP-hard. The job shop scheduling problems with late work criterion and non-preemptive jobs are addressed in this paper. Late work criterion is a fairly new objective function. It is a qualitative measure and concerns with late parts of the jobs, unlike classical objective functions that are quantitative measures. In this work, simulated annealing was presented to solve the scheduling problem. In addition, operation based representation was used to encode the solution, and a neighbourhood search structure was employed to search for the new solutions. The case studies are Lawrence instances that were taken from the Operations Research Library. Computational results of this probabilistic meta-heuristic algorithm were compared with a conventional genetic algorithm, and a conclusion was made based on the algorithm and problem.

  11. Boost-invariant early time dynamics from AdS/CFT

    International Nuclear Information System (INIS)

    Beuf, Guillaume; Peschanski, Robi; Heller, Michal P.; Janik, Romuald A.

    2009-01-01

    Boost-invariant dynamics of a strongly-coupled conformal plasma is studied in the regime of early proper-time using the AdS/CFT correspondence. It is shown, in contrast with the late-time expansion, that a scaling solution does not exist. The boundary dynamics in this regime depends on initial conditions encoded in the bulk behavior of a Fefferman-Graham metric coefficient at initial proper-time. The relation between the early-time expansion of the energy density and initial conditions in the bulk of AdS is provided. As a general result it is proven that a singularity of some metric coefficient in Fefferman-Graham frame exists at all times. Requiring that this singularity at τ = 0 is a mere coordinate singularity without the curvature blow-up gives constraints on the possible boundary dynamics. Using a simple Pade resummation for solutions satisfying the regularity constraint, the features of a transition to local equilibrium, and thus to the hydrodynamical late-time regime, have been observed. The impact of this study on the problem of thermalization is discussed.

  12. Comparing Measures of Late HIV Diagnosis in Washington State

    Directory of Open Access Journals (Sweden)

    Laura Saganic

    2012-01-01

    Full Text Available As more US HIV surveillance programs routinely use late HIV diagnosis to monitor and characterize HIV testing patterns, there is an increasing need to standardize how late HIV diagnosis is measured. In this study, we compared two measures of late HIV diagnosis, one based on time between HIV and AIDS, the other based on initial CD4+ results. Using data from Washington's HIV/AIDS Reporting System, we used multivariate logistic regression to identify predictors of late HIV diagnosis. We also conducted tests for trend to determine whether the proportion of cases diagnosed late has changed over time. Both measures lead us to similar conclusions about late HIV diagnosis, suggesting that being male, older, foreign-born, or heterosexual increase the likelihood of late HIV diagnosis. Our findings reaffirm the validity of a time-based definition of late HIV diagnosis, while at the same time demonstrating the potential value of a lab-based measure.

  13. Iterated local search algorithm for solving the orienteering problem with soft time windows.

    Science.gov (United States)

    Aghezzaf, Brahim; Fahim, Hassan El

    2016-01-01

    In this paper we study the orienteering problem with time windows (OPTW) and the impact of relaxing the time windows on the profit collected by the vehicle. The way of relaxing time windows adopted in the orienteering problem with soft time windows (OPSTW) that we study in this research is a late service relaxation that allows linearly penalized late services to customers. We solve this problem heuristically by considering a hybrid iterated local search. The results of the computational study show that the proposed approach is able to achieve promising solutions on the OPTW test instances available in the literature, one new best solution is found. On the newly generated test instances of the OPSTW, the results show that the profit collected by the OPSTW is better than the profit collected by the OPTW.

  14. Exact solutions of time-dependent Dirac equations and the quantum-classical correspondence

    International Nuclear Information System (INIS)

    Zhang Zhiguo

    2006-01-01

    Exact solutions to the Dirac equations with a time-dependent mass and a static magnetic field or a time-dependent linear potential are given. Matrix elements of the coordinate, momentum and velocity operator are calculated. In the large quantum number limit, these matrix elements give the classical solution

  15. Solution of large nonlinear time-dependent problems using reduced coordinates

    International Nuclear Information System (INIS)

    Mish, K.D.

    1987-01-01

    This research is concerned with the idea of reducing a large time-dependent problem, such as one obtained from a finite-element discretization, down to a more manageable size while preserving the most-important physical behavior of the solution. This reduction process is motivated by the concept of a projection operator on a Hilbert Space, and leads to the Lanczos Algorithm for generation of approximate eigenvectors of a large symmetric matrix. The Lanczos Algorithm is then used to develop a reduced form of the spatial component of a time-dependent problem. The solution of the remaining temporal part of the problem is considered from the standpoint of numerical-integration schemes in the time domain. All of these theoretical results are combined to motivate the proposed reduced coordinate algorithm. This algorithm is then developed, discussed, and compared to related methods from the mechanics literature. The proposed reduced coordinate method is then applied to the solution of some representative problems in mechanics. The results of these problems are discussed, conclusions are drawn, and suggestions are made for related future research

  16. Modeling the Quiet Time Outflow Solution in the Polar Cap

    Science.gov (United States)

    Glocer, Alex

    2011-01-01

    We use the Polar Wind Outflow Model (PWOM) to study the geomagnetically quiet conditions in the polar cap during solar maximum, The PWOM solves the gyrotropic transport equations for O(+), H(+), and He(+) along several magnetic field lines in the polar region in order to reconstruct the full 3D solution. We directly compare our simulation results to the data based empirical model of Kitamura et al. [2011] of electron density, which is based on 63 months of Akebono satellite observations. The modeled ion and electron temperatures are also compared with a statistical compilation of quiet time data obtained by the EISCAT Svalbard Radar (ESR) and Intercosmos Satellites (Kitamura et al. [2011]). The data and model agree reasonably well. This study shows that photoelectrons play an important role in explaining the differences between sunlit and dark results, ion composition, as well as ion and electron temperatures of the quiet time polar wind solution. Moreover, these results provide validation of the PWOM's ability to model the quiet time ((background" solution.

  17. Searching for the Expelled Hydrogen Envelope in Type I Supernovae via Late-Time H α Emission

    Energy Technology Data Exchange (ETDEWEB)

    Vinko, J.; Silverman, J. M.; Wheeler, J. C.; MacQueen, P.; Marion, G. H. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Pooley, D. [Department of Physics and Astronomy, Trinity University, One Trinity Place, San Antonio, TX 78212 (United States); Szalai, T. [Department of Optics and Quantum Electronics, University of Szeged, Dom ter 9, Szeged, 6720 (Hungary); Kelly, P. [Department of Astronomy, University of California at Berkeley, 501 Campbell Hall, Berkeley, CA 94720-3411 (United States); Sárneczky, K. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege ut 15-17, Budapest, 1121 (Hungary)

    2017-03-01

    We report the first results from our long-term observational survey aimed at discovering late-time interaction between the ejecta of hydrogen-poor Type I supernovae (SNe I) and the hydrogen-rich envelope expelled from the progenitor star several decades/centuries before explosion. The expelled envelope, moving with a velocity of ∼10–100 km s{sup −1}, is expected to be caught up by the fast-moving SN ejecta several years/decades after explosion, depending on the history of the mass-loss process acting in the progenitor star prior to explosion. The collision between the SN ejecta and the circumstellar envelope results in net emission in the Balmer lines, especially H α . We look for signs of late-time H α emission in older SNe Ia/Ibc/IIb with hydrogen-poor ejecta via narrowband imaging. Continuum-subtracted H α emission has been detected for 13 point sources: 9 SN Ibc, 1 SN IIb, and 3 SN Ia events. Thirty-eight SN sites were observed on at least two epochs, from which three objects (SN 1985F, SN 2005kl, and SN 2012fh) showed significant temporal variation in the strength of their H α emission in our Direct Imaging Auxiliary Functions Instrument (DIAFI) data. This suggests that the variable emission is probably not due to nearby H ii regions unassociated with the SN and hence is an important additional hint that ejecta–circumstellar medium interaction may take place in these systems. Moreover, we successfully detected the late-time H α emission from the Type Ib SN 2014C, which was recently discovered as a strongly interacting SN in various (radio, infrared, optical, and X-ray) bands.

  18. Topological and non-topological soliton solutions to some time

    Indian Academy of Sciences (India)

    Topological and non-topological soliton solutions to some time-fractional differential equations ... These equations have been widely applied in many branches of nonlinear ... Department of Engineering Sciences, Faculty of Technology and ...

  19. Dynamic Beam Solutions for Real-Time Simulation and Control Development of Flexible Rockets

    Science.gov (United States)

    Su, Weihua; King, Cecilia K.; Clark, Scott R.; Griffin, Edwin D.; Suhey, Jeffrey D.; Wolf, Michael G.

    2016-01-01

    In this study, flexible rockets are structurally represented by linear beams. Both direct and indirect solutions of beam dynamic equations are sought to facilitate real-time simulation and control development for flexible rockets. The direct solution is completed by numerically integrate the beam structural dynamic equation using an explicit Newmark-based scheme, which allows for stable and fast transient solutions to the dynamics of flexile rockets. Furthermore, in the real-time operation, the bending strain of the beam is measured by fiber optical sensors (FOS) at intermittent locations along the span, while both angular velocity and translational acceleration are measured at a single point by the inertial measurement unit (IMU). Another study in this paper is to find the analytical and numerical solutions of the beam dynamics based on the limited measurement data to facilitate the real-time control development. Numerical studies demonstrate the accuracy of these real-time solutions to the beam dynamics. Such analytical and numerical solutions, when integrated with data processing and control algorithms and mechanisms, have the potential to increase launch availability by processing flight data into the flexible launch vehicle's control system.

  20. Averaged multivalued solutions and time discretization for conservation laws

    International Nuclear Information System (INIS)

    Brenier, Y.

    1985-01-01

    It is noted that the correct shock solutions can be approximated by averaging in some sense the multivalued solution given by the method of characteristics for the nonlinear scalar conservation law (NSCL). A time discretization for the NSCL equation based on this principle is considered. An equivalent analytical formulation is shown to lead quite easily to a convergence result, and a third formulation is introduced which can be generalized for the systems of conservation laws. Various numerical schemes are constructed from the proposed time discretization. The first family of schemes is obtained by using a spatial grid and projecting the results of the time discretization. Many known schemes are then recognized (mainly schemes by Osher, Roe, and LeVeque). A second way to discretize leads to a particle scheme without space grid, which is very efficient (at least in the scalar case). Finally, a close relationship between the proposed method and the Boltzmann type schemes is established. 14 references

  1. Characterizing multiple solutions to the time-energy canonical commutation relation via internal symmetries

    International Nuclear Information System (INIS)

    Caballar, Roland Cristopher F.; Ocampo, Leonard R.; Galapon, Eric A.

    2010-01-01

    Internal symmetries can be used to classify multiple solutions to the time-energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR possessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.

  2. Reducing Disparity in Radio-Isotopic and Astrochronology-Based Time Scales of the Late Eocene and Oligocene

    NARCIS (Netherlands)

    Sahy, Diana; Condon, Daniel J.; Hilgen, Frederik J.|info:eu-repo/dai/nl/102639876; Kuiper, Klaudia F.|info:eu-repo/dai/nl/258125772

    2017-01-01

    A significant discrepancy of up to 0.6 Myr exists between radio-isotopically calibrated and astronomically tuned time scales of the late Eocene-Oligocene. We explore the possible causes of this discrepancy through the acquisition of “high-precision” 206Pb/238U dating of zircons from 11 volcanic ash

  3. Exact solution of a quantum forced time-dependent harmonic oscillator

    Science.gov (United States)

    Yeon, Kyu Hwang; George, Thomas F.; Um, Chung IN

    1992-01-01

    The Schrodinger equation is used to exactly evaluate the propagator, wave function, energy expectation values, uncertainty values, and coherent state for a harmonic oscillator with a time dependent frequency and an external driving time dependent force. These quantities represent the solution of the classical equation of motion for the time dependent harmonic oscillator.

  4. DETECTION OF BROAD Hα EMISSION LINES IN THE LATE-TIME SPECTRA OF A HYDROGEN-POOR SUPERLUMINOUS SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Lin; Masci, F. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Quimby, R. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Ofek, E.; Gal-Yam, A.; Vreeswijk, P. M.; Leloudas, G.; Cia, A. de; Yaron, O. [Department of Particle Physics and Astrophysics, Faculty of Physics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Cao, Y.; Kulkarni, S. R. [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, P. E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Rebbapragada, Umaa D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Woźniak, P. R., E-mail: lyan@ipac.caltech.edu [Space and Remote Sensing, ISR-2, MS-B244 Los Alamos National Laboratory Los Alamos, NM 87545 (United States)

    2015-12-01

    iPTF13ehe is a hydrogen-poor superluminous supernova (SLSN) at z = 0.3434, with a slow-evolving light curve and spectral features similar to SN2007bi. It rises in 83–148 days to reach a peak bolometric luminosity of ∼1.3 × 10{sup 44} erg s{sup −1}, then decays slowly at 0.015 mag day{sup −1}. The measured ejecta velocity is ∼ 13,000 km s{sup −1}. The inferred explosion characteristics, such as the ejecta mass (70–220 M{sub ⊙}), and the total radiative and kinetic energy (E{sub rad} ∼ 10{sup 51} erg, E{sub kin} ∼ 2 × 10{sup 53} erg), are typical of slow-evolving H-poor SLSN events. However, the late-time spectrum taken at +251 days (rest, post-peak) reveals a Balmer Hα emission feature with broad and narrow components, which has never been detected before among other H-poor SLSNe. The broad component has a velocity width of ∼4500 km s{sup −1} and a ∼300 km s{sup −1} blueward shift relative to the narrow component. We interpret this broad Hα emission with a luminosity of ∼2 × 10{sup 41} erg s{sup −1} as resulting from the interaction between the supernova ejecta and a discrete H-rich shell, located at a distance of ∼4 × 10{sup 16} cm from the explosion site. This interaction causes the rest-frame r-band LC to brighten at late times. The fact that the late-time spectra are not completely absorbed by the shock-ionized H-shell implies that its Thomson scattering optical depth is likely ≤1, thus setting upper limits on the shell mass ≤30 M{sub ⊙}. Of the existing models, a Pulsational Pair Instability supernova model can naturally explain the observed 30 M{sub ⊙} H-shell, ejected from a progenitor star with an initial mass of (95–150) M{sub ⊙} about 40 years ago. We estimate that at least ∼15% of all SLSNe-I may have late-time Balmer emission lines.

  5. Almost Periodic Solution for Memristive Neural Networks with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Huaiqin Wu

    2013-01-01

    Full Text Available This paper is concerned with the dynamical stability analysis for almost periodic solution of memristive neural networks with time-varying delays. Under the framework of Filippov solutions, by applying the inequality analysis techniques, the existence and asymptotically almost periodic behavior of solutions are discussed. Based on the differential inclusions theory and Lyapunov functional approach, the stability issues of almost periodic solution are investigated, and a sufficient condition for the existence, uniqueness, and global exponential stability of the almost periodic solution is established. Moreover, as a special case, the condition which ensures the global exponential stability of a unique periodic solution is also presented for the considered memristive neural networks. Two examples are given to illustrate the validity of the theoretical results.

  6. Finite difference time domain solution of electromagnetic scattering on the hypercube

    International Nuclear Information System (INIS)

    Calalo, R.H.; Lyons, J.R.; Imbriale, W.A.

    1988-01-01

    Electromagnetic fields interacting with a dielectric or conducting structure produce scattered electromagnetic fields. To model the fields produced by complicated, volumetric structures, the finite difference time domain (FDTD) method employs an iterative solution to Maxwell's time dependent curl equations. Implementations of the FDTD method intensively use memory and perform numerous calculations per time step iteration. The authors have implemented an FDTD code on the California Institute of Technology/Jet Propulsion Laboratory Mark III Hypercube. This code allows to solve problems requiring as many as 2,048,000 unit cells on a 32 node Hypercube. For smaller problems, the code produces solutions in a fraction of the time to solve the same problems on sequential computers

  7. Fast Time and Space Parallel Algorithms for Solution of Parabolic Partial Differential Equations

    Science.gov (United States)

    Fijany, Amir

    1993-01-01

    In this paper, fast time- and Space -Parallel agorithms for solution of linear parabolic PDEs are developed. It is shown that the seemingly strictly serial iterations of the time-stepping procedure for solution of the problem can be completed decoupled.

  8. The A-priori Traveling Salesman Problem with Time Windows

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2004-01-01

    seek to minimize lateness and examine the impact of this criterion choice on the distance traveled. Our focus on lateness is motivated by the problem faced by overnight mail service providers. We propose a real-time solution method that requires the vehicle, when idle, to wait at the current customer......In this paper we examine the traveling saleman problem with time windows for various degrees of dynamism. In contrast to the static problem, where the dispatcher can plan ahead, in the dynamic version, part or all of the necessary information becomes available only during the day of operation. We...... randomly generated data and on a real-world case study indicate that all policies proved capable of significantly reducing lateness. Our results also show that this can be accomplished with only small distance increases. The basic policy outperformed the other methods primarily when lateness and distance...

  9. Analytical Solution of Heat Conduction for Hollow Cylinders with Time-Dependent Boundary Condition and Time-Dependent Heat Transfer Coefficient

    Directory of Open Access Journals (Sweden)

    Te-Wen Tu

    2015-01-01

    Full Text Available An analytical solution for the heat transfer in hollow cylinders with time-dependent boundary condition and time-dependent heat transfer coefficient at different surfaces is developed for the first time. The methodology is an extension of the shifting function method. By dividing the Biot function into a constant plus a function and introducing two specially chosen shifting functions, the system is transformed into a partial differential equation with homogenous boundary conditions only. The transformed system is thus solved by series expansion theorem. Limiting cases of the solution are studied and numerical results are compared with those in the literature. The convergence rate of the present solution is fast and the analytical solution is simple and accurate. Also, the influence of physical parameters on the temperature distribution of a hollow cylinder along the radial direction is investigated.

  10. Persistent junk solutions in time-domain modeling of extreme mass ratio binaries

    International Nuclear Information System (INIS)

    Field, Scott E.; Hesthaven, Jan S.; Lau, Stephen R.

    2010-01-01

    In the context of metric perturbation theory for nonspinning black holes, extreme mass ratio binary systems are described by distributionally forced master wave equations. Numerical solution of a master wave equation as an initial boundary value problem requires initial data. However, because the correct initial data for generic-orbit systems is unknown, specification of trivial initial data is a common choice, despite being inconsistent and resulting in a solution which is initially discontinuous in time. As is well known, this choice leads to a burst of junk radiation which eventually propagates off the computational domain. We observe another potential consequence of trivial initial data: development of a persistent spurious solution, here referred to as the Jost junk solution, which contaminates the physical solution for long times. This work studies the influence of both types of junk on metric perturbations, waveforms, and self-force measurements, and it demonstrates that smooth modified source terms mollify the Jost solution and reduce junk radiation. Our concluding section discusses the applicability of these observations to other numerical schemes and techniques used to solve distributionally forced master wave equations.

  11. Non-perturbative analytical solutions of the space- and time-fractional Burgers equations

    International Nuclear Information System (INIS)

    Momani, Shaher

    2006-01-01

    Non-perturbative analytical solutions for the generalized Burgers equation with time- and space-fractional derivatives of order α and β, 0 < α, β ≤ 1, are derived using Adomian decomposition method. The fractional derivatives are considered in the Caputo sense. The solutions are given in the form of series with easily computable terms. Numerical solutions are calculated for the fractional Burgers equation to show the nature of solution as the fractional derivative parameter is changed

  12. Enhancing outpatient clinics management software by reducing patients’ waiting time

    Directory of Open Access Journals (Sweden)

    Iman Almomani

    2016-11-01

    Full Text Available Summary: The Kingdom of Saudi Arabia (KSA gives great attention to improving the quality of services provided by health care sectors including outpatient clinics. One of the main drawbacks in outpatient clinics is long waiting time for patients—which affects the level of patient satisfaction and the quality of services. This article addresses this problem by studying the Outpatient Management Software (OMS and proposing solutions to reduce waiting times. Many hospitals around the world apply solutions to overcome the problem of long waiting times in outpatient clinics such as hospitals in the USA, China, Sri Lanka, and Taiwan. These clinics have succeeded in reducing wait times by 15%, 78%, 60% and 50%, respectively. Such solutions depend mainly on adding more human resources or changing some business or management policies. The solutions presented in this article reduce waiting times by enhancing the software used to manage outpatient clinics services. Both quantitative and qualitative methods have been used to understand current OMS and examine level of patient’s satisfaction. Five main problems that may cause high or unmeasured waiting time have been identified: appointment type, ticket numbering, doctor late arrival, early arriving patient and patients’ distribution list. These problems have been mapped to the corresponding OMS components. Solutions to the above problems have been introduced and evaluated analytically or by simulation experiments. Evaluation of the results shows a reduction in patient waiting time. When late doctor arrival issues are solved, this can reduce the clinic service time by up to 20%. However, solutions for early arriving patients reduces 53.3% of vital time, 20% of the clinic time and overall 30.3% of the total waiting time. Finally, well patient-distribution lists make improvements by 54.2%. Improvements introduced to the patients’ waiting time will consequently affect patients’ satisfaction and improve

  13. Closed form solutions of two time fractional nonlinear wave equations

    Science.gov (United States)

    Akbar, M. Ali; Ali, Norhashidah Hj. Mohd.; Roy, Ripan

    2018-06-01

    In this article, we investigate the exact traveling wave solutions of two nonlinear time fractional wave equations. The fractional derivatives are described in the sense of conformable fractional derivatives. In addition, the traveling wave solutions are accomplished in the form of hyperbolic, trigonometric, and rational functions involving free parameters. To investigate such types of solutions, we implement the new generalized (G‧ / G) -expansion method. The extracted solutions are reliable, useful and suitable to comprehend the optimal control problems, chaotic vibrations, global and local bifurcations and resonances, furthermore, fission and fusion phenomena occur in solitons, the relativistic energy-momentum relation, scalar electrodynamics, quantum relativistic one-particle theory, electromagnetic interactions etc. The results reveal that the method is very fruitful and convenient for exploring nonlinear differential equations of fractional order treated in theoretical physics.

  14. Exact solutions to the time-fractional differential equations via local fractional derivatives

    Science.gov (United States)

    Guner, Ozkan; Bekir, Ahmet

    2018-01-01

    This article utilizes the local fractional derivative and the exp-function method to construct the exact solutions of nonlinear time-fractional differential equations (FDEs). For illustrating the validity of the method, it is applied to the time-fractional Camassa-Holm equation and the time-fractional-generalized fifth-order KdV equation. Moreover, the exact solutions are obtained for the equations which are formed by different parameter values related to the time-fractional-generalized fifth-order KdV equation. This method is an reliable and efficient mathematical tool for solving FDEs and it can be applied to other non-linear FDEs.

  15. Solution of the Markov chain for the dead time problem

    International Nuclear Information System (INIS)

    Degweker, S.B.

    1997-01-01

    A method for solving the equation for the Markov chain, describing the effect of a non-extendible dead time on the statistics of time correlated pulses, is discussed. The equation, which was derived in an earlier paper, describes a non-linear process and is not amenable to exact solution. The present method consists of representing the probability generating function as a factorial cumulant expansion and neglecting factorial cumulants beyond the second. This results in a closed set of non-linear equations for the factorial moments. Stationary solutions of these equations, which are of interest for calculating the count rate, are obtained iteratively. The method is applied to the variable dead time counter technique for estimation of system parameters in passive neutron assay of Pu and reactor noise analysis. Comparisons of results by this method with Monte Carlo calculations are presented. (author)

  16. Histone hypoacetylation is required to maintain late replication timing of constitutive heterochromatin.

    Science.gov (United States)

    Casas-Delucchi, Corella S; van Bemmel, Joke G; Haase, Sebastian; Herce, Henry D; Nowak, Danny; Meilinger, Daniela; Stear, Jeffrey H; Leonhardt, Heinrich; Cardoso, M Cristina

    2012-01-01

    The replication of the genome is a spatio-temporally highly organized process. Yet, its flexibility throughout development suggests that this process is not genetically regulated. However, the mechanisms and chromatin modifications controlling replication timing are still unclear. We made use of the prominent structure and defined heterochromatic landscape of pericentric regions as an example of late replicating constitutive heterochromatin. We manipulated the major chromatin markers of these regions, namely histone acetylation, DNA and histone methylation, as well as chromatin condensation and determined the effects of these altered chromatin states on replication timing. Here, we show that manipulation of DNA and histone methylation as well as acetylation levels caused large-scale heterochromatin decondensation. Histone demethylation and the concomitant decondensation, however, did not affect replication timing. In contrast, immuno-FISH and time-lapse analyses showed that lowering DNA methylation, as well as increasing histone acetylation, advanced the onset of heterochromatin replication. While dnmt1(-)(/)(-) cells showed increased histone acetylation at chromocenters, histone hyperacetylation did not induce DNA demethylation. Hence, we propose that histone hypoacetylation is required to maintain normal heterochromatin duplication dynamics. We speculate that a high histone acetylation level might increase the firing efficiency of origins and, concomitantly, advances the replication timing of distinct genomic regions.

  17. Large time behavior of entropy solutions to one-dimensional unipolar hydrodynamic model for semiconductor devices

    Science.gov (United States)

    Huang, Feimin; Li, Tianhong; Yu, Huimin; Yuan, Difan

    2018-06-01

    We are concerned with the global existence and large time behavior of entropy solutions to the one-dimensional unipolar hydrodynamic model for semiconductors in the form of Euler-Poisson equations in a bounded interval. In this paper, we first prove the global existence of entropy solution by vanishing viscosity and compensated compactness framework. In particular, the solutions are uniformly bounded with respect to space and time variables by introducing modified Riemann invariants and the theory of invariant region. Based on the uniform estimates of density, we further show that the entropy solution converges to the corresponding unique stationary solution exponentially in time. No any smallness condition is assumed on the initial data and doping profile. Moreover, the novelty in this paper is about the unform bound with respect to time for the weak solutions of the isentropic Euler-Poisson system.

  18. Is Late or Non-Payment a Significant Problem to Malaysian Contractors?

    Directory of Open Access Journals (Sweden)

    M.E. Che Munaaim

    2007-12-01

    Full Text Available Some developed countries have drawn lip construction-specific statutory security of payment acts/legislations typically known as Construction Contracts Act to eliminate poor payment practices and to assist continuous uninterrupted construction works. Malaysia too cannot pretend not to have these problems. This paper presents findings of a study conducted amongst Malaysian contractors with the aims to determine the seriousness of late and non- payment problems; to identify the main causes and effects of late and non-payment; and to identify ways to sustain the payment flows in the Malaysian construction industry. The study focused on contractual payments from the paymaster (government or private to the contractors. The main factors for late and nonpayment in the construction industry identified from the study include: delay in certification, paymaster's poor financial management, local culture/attitude, pay master's failure to implement good governance in business, underpayment of certified amounts by the pay master and the use of 'pay when paid' clauses in contracts. The research findings show that late and non-payment can create cash flow problems, stress and financial hardship on the contractors. Amongst the most appropriate solutions to overcome the problem of late and non-payment faced by local contractors include: a right to regular periodic payment, a right to a defined time frame (or payment and a right to a speedy dispute resolution mechanism. Promptness of submitting, processing, issuing interim payment certificates and honouring the certificates are extremely important issues in relation to progress payment claims. Perhaps, an increased sense of professionalism in construction industry could overcome some of the problems related to late and non- payment issues.

  19. LAGRANGE SOLUTIONS TO THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

    International Nuclear Information System (INIS)

    Minesaki, Yukitaka

    2013-01-01

    There is no known integrator that yields exact orbits for the general three-body problem (G3BP). It is difficult to verify whether a numerical procedure yields the correct solutions to the G3BP because doing so requires knowledge of all 11 conserved quantities, whereas only six are known. Without tracking all of the conserved quantities, it is possible to show that the discrete general three-body problem (d-G3BP) yields the correct orbits corresponding to Lagrange solutions of the G3BP. We show that the d-G3BP yields the correct solutions to the G3BP for two special cases: the equilateral triangle and collinear configurations. For the triangular solution, we use the fact that the solution to the three-body case is a superposition of the solutions to the three two-body cases, and we show that the three bodies maintain the same relative distances at all times. To obtain the collinear solution, we assume a specific permutation of the three bodies arranged along a straight rotating line, and we show that the d-G3BP maintains the same distance ratio between two bodies as in the G3BP. Proving that the d-G3BP solutions for these cases are equivalent to those of the G3BP makes it likely that the d-G3BP and G3BP solutions are equivalent in other cases. To our knowledge, this is the first work that proves the equivalence of the discrete solutions and the Lagrange orbits.

  20. Analysis of user equilibrium for staggered shifts in a single-entry traffic corridor with no late arrivals

    Science.gov (United States)

    Li, Chuan-Yao; Huang, Hai-Jun; Tang, Tie-Qiao

    2017-05-01

    In this paper, we investigate the effects of staggered shifts on the user equilibrium (UE) state in a single-entry traffic corridor with no late arrivals from the analytical and numerical perspective. The LWR (Lighthill-Whitham-Richards) model and the Greenshields' velocity-density function are used to describe the dynamic properties of traffic flow. Propositions for the properties of flow patterns in UE, and the quasi-analytic solutions for three possible situations in UE are deduced. Numerical tests are carried out to testify the analytical results, where the three-dimensional evolution diagram of traffic flow illustrates that shock and rarefaction wave exist in UE and the space-time diagram indicates that UE solutions satisfy the propagation properties of traffic flow. In addition, the cost curves show that the UE solutions satisfy the UE trip-timing condition.

  1. Anharmonic solution of Schrödinger time-independent equation

    Indian Academy of Sciences (India)

    243–261. Anharmonic solution of Schrödinger time-independent equation. MOHAMMED ASHRAFUL ISLAM1,2,∗ and JAMAL NAZRUL ISLAM1. 1Research Centre for Mathematical and Physical Sciences, University of Chittagong, Chittagong,. Bangladesh. 2Department of Mathematics, University of Chittagong, Chittagong, ...

  2. Large-time asymptotic behaviour of solutions of non-linear Sobolev-type equations

    International Nuclear Information System (INIS)

    Kaikina, Elena I; Naumkin, Pavel I; Shishmarev, Il'ya A

    2009-01-01

    The large-time asymptotic behaviour of solutions of the Cauchy problem is investigated for a non-linear Sobolev-type equation with dissipation. For small initial data the approach taken is based on a detailed analysis of the Green's function of the linear problem and the use of the contraction mapping method. The case of large initial data is also closely considered. In the supercritical case the asymptotic formulae are quasi-linear. The asymptotic behaviour of solutions of a non-linear Sobolev-type equation with a critical non-linearity of the non-convective kind differs by a logarithmic correction term from the behaviour of solutions of the corresponding linear equation. For a critical convective non-linearity, as well as for a subcritical non-convective non-linearity it is proved that the leading term of the asymptotic expression for large times is a self-similar solution. For Sobolev equations with convective non-linearity the asymptotic behaviour of solutions in the subcritical case is the product of a rarefaction wave and a shock wave. Bibliography: 84 titles.

  3. New analytical exact solutions of time fractional KdV-KZK equation by Kudryashov methods

    Science.gov (United States)

    S Saha, Ray

    2016-04-01

    In this paper, new exact solutions of the time fractional KdV-Khokhlov-Zabolotskaya-Kuznetsov (KdV-KZK) equation are obtained by the classical Kudryashov method and modified Kudryashov method respectively. For this purpose, the modified Riemann-Liouville derivative is used to convert the nonlinear time fractional KdV-KZK equation into the nonlinear ordinary differential equation. In the present analysis, the classical Kudryashov method and modified Kudryashov method are both used successively to compute the analytical solutions of the time fractional KdV-KZK equation. As a result, new exact solutions involving the symmetrical Fibonacci function, hyperbolic function and exponential function are obtained for the first time. The methods under consideration are reliable and efficient, and can be used as an alternative to establish new exact solutions of different types of fractional differential equations arising from mathematical physics. The obtained results are exhibited graphically in order to demonstrate the efficiencies and applicabilities of these proposed methods of solving the nonlinear time fractional KdV-KZK equation.

  4. Larger miliolids of the Late Cretaceous and Paleogene seen through space and time

    Directory of Open Access Journals (Sweden)

    Vlasta Ćosović

    2002-12-01

    Full Text Available Spatial and temporal occurrences of the larger (complex miliolids are discussed to give more light on biostratigraphy and paleobiogeographic provinces distribution. Seven generaand 47 species from the Late Cretaceous to Oligocene inhabited shallow marine settings in the Indo-Pacific, Tethyan and Caribbean regions. Of all genera only four (Idalina, Periloculina, Pseudolacazina, Lacazina widespread throughout Tethys in theLate Cretaceous and Paleogene. Single occurrence of Lacazina was recorded further to east (Moluccas. By now the Late Cretaceous genus Adrahentina is known only from the Spain. The newcomer’s Eocene genera were Fabularia and Lacazinella. Fabularia reachedhigh diversity in species term in the Central and Western Tethys and occured as unique genus in Caribbean realm, too. Conversely, during the same period, Lacazinella spread over the southern border of Neo-Tethys reaching New Guinea.On the Adriatic – Dinaric Carbonate Platform, larger miliolids occurred from the Late Cretaceous to Cuisian, having the same biostratigraphically trends and distribution as contemporaneous larger miliolids from the Tethys.

  5. Explicit solution of Calderon preconditioned time domain integral equations

    KAUST Repository

    Ulku, Huseyin Arda

    2013-07-01

    An explicit marching on-in-time (MOT) scheme for solving Calderon-preconditioned time domain integral equations is proposed. The scheme uses Rao-Wilton-Glisson and Buffa-Christiansen functions to discretize the domain and range of the integral operators and a PE(CE)m type linear multistep to march on in time. Unlike its implicit counterpart, the proposed explicit solver requires the solution of an MOT system with a Gram matrix that is sparse and well-conditioned independent of the time step size. Numerical results demonstrate that the explicit solver maintains its accuracy and stability even when the time step size is chosen as large as that typically used by an implicit solver. © 2013 IEEE.

  6. A Simulated Annealing-Based Heuristic Algorithm for Job Shop Scheduling to Minimize Lateness

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2013-04-01

    Full Text Available A decomposition-based optimization algorithm is proposed for solving large job shop scheduling problems with the objective of minimizing the maximum lateness. First, we use the constraint propagation theory to derive the orientation of a portion of disjunctive arcs. Then we use a simulated annealing algorithm to find a decomposition policy which satisfies the maximum number of oriented disjunctive arcs. Subsequently, each subproblem (corresponding to a subset of operations as determined by the decomposition policy is successively solved with a simulated annealing algorithm, which leads to a feasible solution to the original job shop scheduling problem. Computational experiments are carried out for adapted benchmark problems, and the results show the proposed algorithm is effective and efficient in terms of solution quality and time performance.

  7. A greigite-based magnetostratigraphic time frame for the Late Miocene to recent DSDP Leg 42B Cores from the Black Sea

    NARCIS (Netherlands)

    Van Baak, Christiaan G. C.; Vasiliev, Iuliana; Palcu, Dan V.; Dekkers, Mark J.; Krijgsman, Wout

    2016-01-01

    Throughout the Late Neogene, the Black Sea experienced large paleoenvironmental changes, switching between (anoxic) marine conditions when connected to the Mediterranean Sea and (oxic) freshwater conditions at times of isolation. We create a magnetostratigraphic time frame for three sites drilled

  8. Early-Time Solution of the Horizontal Unconfined Aquifer in the Buildup Phase

    Science.gov (United States)

    Gravanis, Elias; Akylas, Evangelos

    2017-10-01

    We derive the early-time solution of the Boussinesq equation for the horizontal unconfined aquifer in the buildup phase under constant recharge and zero inflow. The solution is expressed as a power series of a suitable similarity variable, which is constructed so that to satisfy the boundary conditions at both ends of the aquifer, that is, it is a polynomial approximation of the exact solution. The series turns out to be asymptotic and it is regularized by resummation techniques that are used to define divergent series. The outflow rate in this regime is linear in time, and the (dimensionless) coefficient is calculated to eight significant figures. The local error of the series is quantified by its deviation from satisfying the self-similar Boussinesq equation at every point. The local error turns out to be everywhere positive, hence, so is the integrated error, which in turn quantifies the degree of convergence of the series to the exact solution.

  9. Soliton solutions of some nonlinear evolution equations with time ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we obtain exact soliton solutions of the modified KdV equation, inho- mogeneous nonlinear Schrödinger equation and G(m, n) equation with variable coefficients using solitary wave ansatz. The constraint conditions among the time-dependent coefficients turn out as necessary conditions for the ...

  10. On spurious resonant modes in the MOT solution of time domain EFIE

    KAUST Repository

    Shi, Yifei; Bagci, Hakan; Lu, Mingyu

    2013-01-01

    Theoretically, internal resonant modes should not be induced in the marching-on-in-time (MOT) solution of the time domain electric field integral equation since zero initial conditions are enforced at the beginning of time marching and the internal

  11. New analytical exact solutions of time fractional KdV–KZK equation by Kudryashov methods

    International Nuclear Information System (INIS)

    Saha Ray, S

    2016-01-01

    In this paper, new exact solutions of the time fractional KdV–Khokhlov–Zabolotskaya–Kuznetsov (KdV–KZK) equation are obtained by the classical Kudryashov method and modified Kudryashov method respectively. For this purpose, the modified Riemann–Liouville derivative is used to convert the nonlinear time fractional KdV–KZK equation into the nonlinear ordinary differential equation. In the present analysis, the classical Kudryashov method and modified Kudryashov method are both used successively to compute the analytical solutions of the time fractional KdV–KZK equation. As a result, new exact solutions involving the symmetrical Fibonacci function, hyperbolic function and exponential function are obtained for the first time. The methods under consideration are reliable and efficient, and can be used as an alternative to establish new exact solutions of different types of fractional differential equations arising from mathematical physics. The obtained results are exhibited graphically in order to demonstrate the efficiencies and applicabilities of these proposed methods of solving the nonlinear time fractional KdV–KZK equation. (paper)

  12. Displacement in the parameter space versus spurious solution of discretization with large time step

    International Nuclear Information System (INIS)

    Mendes, Eduardo; Letellier, Christophe

    2004-01-01

    In order to investigate a possible correspondence between differential and difference equations, it is important to possess discretization of ordinary differential equations. It is well known that when differential equations are discretized, the solution thus obtained depends on the time step used. In the majority of cases, such a solution is considered spurious when it does not resemble the expected solution of the differential equation. This often happens when the time step taken into consideration is too large. In this work, we show that, even for quite large time steps, some solutions which do not correspond to the expected ones are still topologically equivalent to solutions of the original continuous system if a displacement in the parameter space is considered. To reduce such a displacement, a judicious choice of the discretization scheme should be made. To this end, a recent discretization scheme, based on the Lie expansion of the original differential equations, proposed by Monaco and Normand-Cyrot will be analysed. Such a scheme will be shown to be sufficient for providing an adequate discretization for quite large time steps compared to the pseudo-period of the underlying dynamics

  13. Anatomy of the late radiation encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    De Reuck, J; vander Eecken, H

    1975-01-01

    The clinico-pathological data and the topography of the lesions were determined in 13 cases of late radiation encephalopathy. In one case the arterial vascularisation was studied by the translucidation technique after filling of the blood vessels with a colloidal barium sulphate solution. The radiation lesions consisted of areas of focal necrosis and of diffuse demyelination and necrosis of the deep cerebral structures and the brain stem. Demyelination was predominantly present in cases of late appearance of the neurological symptoms while necrosis was found in cases with a short latency period. The cerebral cortex and the arcuate fibres were always the most preserved structures. The topography of the focal lesions in the cerebral hemispheres and in the brain stem corresponded well to the vascular supply areas of the deep perforating arteries, while the diffuse lesions always had a predominant distribution in the periventricular arterial end- and border-zones. These observations were also confirmed by a post mortem angiographic study. The present report argues once more for a vascular aetiology as cause of the late radiation encephalopathy.

  14. Effects of Unsaturated Zones on Baseflow Recession: Analytical Solution and Application

    Science.gov (United States)

    Zhan, H.; Liang, X.; Zhang, Y. K.

    2017-12-01

    Unsaturated flow is an important process in baseflow recessions and its effect is rarely investigated. A mathematical model for a coupled unsaturated-saturated flow in a horizontally unconfined aquifer with time-dependent infiltrations is presented. Semi-analytical solutions for hydraulic heads and discharges are derived using Laplace transform and Cosine transform. The solutions are compared with solutions of the linearized Boussinesq equation (LB solution) and the linearized Laplace equation (LL solution), respectively. The result indicates that a larger dimensionless constitutive exponent κD of the unsaturated zone leads to a smaller discharge during the infiltration period and a larger discharge after the infiltration. The lateral discharge of the unsaturated zone is significant when κD≤1, and becomes negligible when κD≥100. For late times, the power index b of the recession curve-dQ/dt aQb, is 1 and independent of κD, where Q is the baseflow and a is a constant lumped aquifer parameter. For early times, b is approximately equal to 3 but it approaches infinity when t→1. The present solution is applied to synthetic and field cases. The present solution matched the synthetic data better than both the LL and LB solutions, with a minimum relative error of 16% for estimate of hydraulic conductivity. The present solution was applied to the observed streamflow discharge in Iowa, and the estimated values of the aquifer parameters were reasonable.

  15. Late somatic effects

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1989-01-01

    Late effects are by definition effects that occur at least one year, and in most cases decades, after the time of exposure. The late effects considered in this chapter are limited to latent cancer incidence and mortality, and benign thyroid disease. A model is provided for estimating risks of late effects resulting from the radiation exposure likely to be received in the event of a nuclear power plant accident. It is assumed that exposure to high-LET radiation would be negligible in such an accident, and thus only risks from low-LET exposure are evaluated. Separate estimates are provided for risks of leukemia, bone cancer, lung cancer, gastrointestinal cancers, thyroid cancer, skin cancer, and the residual group of all other cancers; estimates of leukemia and other cancers due to in utero exposure are also provided. Risks are expressed in absolute terms as the number of cancer deaths (or cases) per million persons exposed to a particular dose. Because the time of death is also important in assessing the impact of an accident, and because the quality of life after the occurrence of cancer will often be reduced, the number of years of life lost and the number of years of life lived after the occurrence of cancer are also estimated

  16. A Green's function solution for a rectangular heat source on an infinite plate

    International Nuclear Information System (INIS)

    Bainbridge, B.L.

    1989-01-01

    The applications associated with a rectangular heat source on an infinite plate range from integrated circuits to thin film heat flux sensors on thin substrates. The particular problem from which the solution is developed concerns the use of a resistive strip for monitoring currents generated in circuits exposed to electromagnetic fields. The Green's function formulation is solved by using early and late time approximations for which analytical solutions can be derived. In this paper expressions are developed for three sets of boundary conditions and compared to the experimental performance of a physical device

  17. Diurnal phase of late-night against late-afternoon of stratiform and convective precipitation in summer southern contiguous China

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Rucong [Chinese Academy of Sciences, LASG, Institute of Atmospheric Physics, Beijing (China); China Meteorological Administration, LaSW, Chinese Academy of Meteorological Sciences, Beijing (China); Yuan, Weihua [Chinese Academy of Sciences, LASG, Institute of Atmospheric Physics, Beijing (China); Graduate School of the Chinese Academy of Sciences, Beijing (China); Li, Jian [China Meteorological Administration, LaSW, Chinese Academy of Meteorological Sciences, Beijing (China); Fu, Yunfei [Chinese Academy of Sciences, LASG, Institute of Atmospheric Physics, Beijing (China); University of Science and Technology of China, Laboratory of Satellite Remote Sensing and Climate Environment, Hefei, Anhui (China)

    2010-09-15

    Using the tropical rainfall measuring mission (TRMM) Precipitation Radar (PR) observations combined with the surface rain gauge data during 1998-2006, the robust diurnal features of summer stratiform and convective precipitation over the southern contiguous China are revealed by exploring the diurnal variations of rain rate and precipitation profile. The precipitation over the southern contiguous China exhibits two distinguishing diurnal phases: late-night (2200-0600 LST) and late-afternoon (1400-2200 LST), dependent on the location, precipitation type and duration time. Generally, the maximum rain rate and the highest profile of stratiform precipitation occur in the late-afternoon (late-night) over the southeastern (southwestern) China, while most of the stratiform short-duration rain rate tends to present late-afternoon peaks over the southern China. For convective precipitation, the maximum rain rate and the highest profile occur in the late-afternoon over most of the southern contiguous China, while the convective long-duration rain rate exhibits late-night peaks over the southwestern China. Without regional dependence, the convective precipitation exhibits much larger amplitude of diurnal variations in both near surface rain rate and vertical extension compared with stratiform precipitation and the convective rain top rises most rapidly between noon and afternoon. However, there are two distinctive sub-regions. The diurnal phases of precipitation there are very weakly dependent on precipitation type and duration time. Over the eastern periphery of the Tibetan Plateau, the maximum rain rate and the highest profile of either convective or stratiform precipitation occur in the late-night. Over the southeastern coastal regions, both the near surface rain rate and rain top of convective and stratiform precipitation peak in the late-afternoon. (orig.)

  18. Rainfall thresholds as support for timing fungicide applications in the control of potato late blight in Ecuador and Peru

    DEFF Research Database (Denmark)

    Kromann, Peter; Taipe, Arturo; Perez, Willmer G.

    2009-01-01

    Accumulated rainfall thresholds were studied in seven field experiments conducted in Ecuador and Peru for their value in timing applications of fungicide to control potato late blight, caused by Phytophthora infestans. Fungicide regimes based on accumulated rainfall thresholds ranging from 10 to 70...

  19. Single molecule diffusion and the solution of the spherically symmetric residence time equation.

    Science.gov (United States)

    Agmon, Noam

    2011-06-16

    The residence time of a single dye molecule diffusing within a laser spot is propotional to the total number of photons emitted by it. With this application in mind, we solve the spherically symmetric "residence time equation" (RTE) to obtain the solution for the Laplace transform of the mean residence time (MRT) within a d-dimensional ball, as a function of the initial location of the particle and the observation time. The solutions for initial conditions of potential experimental interest, starting in the center, on the surface or uniformly within the ball, are explicitly presented. Special cases for dimensions 1, 2, and 3 are obtained, which can be Laplace inverted analytically for d = 1 and 3. In addition, the analytic short- and long-time asymptotic behaviors of the MRT are derived and compared with the exact solutions for d = 1, 2, and 3. As a demonstration of the simplification afforded by the RTE, the Appendix obtains the residence time distribution by solving the Feynman-Kac equation, from which the MRT is obtained by differentiation. Single-molecule diffusion experiments could be devised to test the results for the MRT presented in this work. © 2011 American Chemical Society

  20. Rats' learned preferences for flavors encountered early or late in a meal paired with the postingestive effects of glucose.

    Science.gov (United States)

    Myers, Kevin P; Whitney, Margaret C

    2011-03-28

    Rats learn to prefer flavors that are followed by postingestive effects of nutrients. This experiment investigated whether the timing of a flavor (specifically, in the first or second half of the meal) influences learning about that flavor. Stronger learning about earlier or later flavors would indicate when the rewarding postingestive effects of nutrients are sensed. Rats with intragastric (IG) catheters drank saccharin-sweetened, calorically-dilute solutions with distinct flavors added, accompanied by IG infusion of glucose (+sessions) or water (-sessions). In both types of sessions, an "Early" flavor was provided for the first 8 min and a "Late" flavor for the last 8 min. Thus, rats were trained with Early(+) and Late(+) in high-calorie meals, and Early(-) and Late(-) in low-calorie meals. Strength of the learned preference for Early(+) and Late(+) was then assessed in a series of two-bottle choice tests between Early(+) vs. Early(-), Late(+) vs. Late(-), Early(+) vs. Late(+), and Early(-) vs. Late(-). Rats preferred both Early(+) and Late(+) over the respective (-) flavors. But Early(+) was only preferred when rats were tested hungry. Late(+) was preferred when rats were tested hungry or recently satiated. This indicates qualitatively different associations learned about flavors at different points in the meal. While not supporting the idea that postingestive effects become most strongly associated with later-occurring ("dessert") flavors, it does suggest a reason dessert flavors may remain attractive in the absence of hunger. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. An explicit solution for a renewal process with waiting time and its variational principle

    International Nuclear Information System (INIS)

    Lewins, J.D.

    2001-01-01

    The forward and backward equations for the conditional probability density are derived for a reliability system consisting of a single component whose repair is subject to a delay time in providing a spare part but whose mean rate of repair is otherwise constant and whose time to failure is exponentially distributed. Exact solutions are quoted. These equations are then shown to be an adjoint pair that provide stationary conditions for a variational principle, in elementary form, from which all properties of the systems can be predicted with an accuracy greater than that implied by the trial functions or approximations used. A second or specific form of variational principle provides specific estimates to questions at hand. The second or adjoint field in the first elementary principle is the backward Kolmogorov solution and the in the specific form is the importance function, as used in nuclear reactor theory. The solutions are given for long-time and in a recurrence relation form valid for all times so that approximate solutions can be checked. Approximations suitable for variational trial functions are given. Two examples give the effect of a change of delay time for a steady state and an initial transient, respectively

  2. Wide localized solutions of the parity-time-symmetric nonautonomous nonlinear Schrödinger equation

    Science.gov (United States)

    Meza, L. E. Arroyo; Dutra, A. de Souza; Hott, M. B.; Roy, P.

    2015-01-01

    By using canonical transformations we obtain localized (in space) exact solutions of the nonlinear Schrödinger equation (NLSE) with cubic and quintic space and time modulated nonlinearities and in the presence of time-dependent and inhomogeneous external potentials and amplification or absorption (source or drain) coefficients. We obtain a class of wide localized exact solutions of NLSE in the presence of a number of non-Hermitian parity-time (PT )-symmetric external potentials, which are constituted by a mixing of external potentials and source or drain terms. The exact solutions found here can be applied to theoretical studies of ultrashort pulse propagation in optical fibers with focusing and defocusing nonlinearities. We show that, even in the presence of gain or loss terms, stable solutions can be found and that the PT symmetry is an important feature to guarantee the conservation of the average energy of the system.

  3. Stability and periodicity of solutions for delay dynamic systems on time scales

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Zhu

    2014-04-01

    Full Text Available This article concerns the stability and periodicity of solutions to the delay dynamic system $$ x^{\\triangle}(t=A(t x(t + F(t, x(t, x(g(t+C(t $$ on a time scale. By the inequality technique for vectors, we obtain some stability criteria for the above system. Then, by using the Horn fixed point theorem, we present some conditions under which our system is asymptotically periodic and its periodic solution is unique. In particular, the periodic solution is positive under proper assumptions.

  4. On the DC loop modes in the MOT solution of the time domain EFIE

    KAUST Repository

    Shi, Yifei; Bagci, Hakan; Lu, Mingyu

    2014-01-01

    When marching-on-in-time (MOT) method is applied to solve the time domain electric field integral equation (TD-EFIE), DC loop modes are always observed in the solution. In theory these modes should not be observed since they do not satisfy the relaxed initial conditions. Their appearance is attributed to numerical errors. It is shown here that when Rao-Wilton-Glisson basis and Lagrange interpolation functions are used to discretize the TD-EFIE, errors due to this space-time discretization have zero impact on the DC loop modes. Numerical experiments demonstrate that the numerical errors due to approximate solution of the MOT matrix system have more dominant impact on DC loop modes in the MOT solution.

  5. Global, finite energy, weak solutions for the NLS with rough, time-dependent magnetic potentials

    Science.gov (United States)

    Antonelli, Paolo; Michelangeli, Alessandro; Scandone, Raffaele

    2018-04-01

    We prove the existence of weak solutions in the space of energy for a class of nonlinear Schrödinger equations in the presence of a external, rough, time-dependent magnetic potential. Under our assumptions, it is not possible to study the problem by means of usual arguments like resolvent techniques or Fourier integral operators, for example. We use a parabolic regularisation, and we solve the approximating Cauchy problem. This is achieved by obtaining suitable smoothing estimates for the dissipative evolution. The total mass and energy bounds allow to extend the solution globally in time. We then infer sufficient compactness properties in order to produce a global-in-time finite energy weak solution to our original problem.

  6. On the DC loop modes in the MOT solution of the time domain EFIE

    KAUST Repository

    Shi, Yifei

    2014-07-01

    When marching-on-in-time (MOT) method is applied to solve the time domain electric field integral equation (TD-EFIE), DC loop modes are always observed in the solution. In theory these modes should not be observed since they do not satisfy the relaxed initial conditions. Their appearance is attributed to numerical errors. It is shown here that when Rao-Wilton-Glisson basis and Lagrange interpolation functions are used to discretize the TD-EFIE, errors due to this space-time discretization have zero impact on the DC loop modes. Numerical experiments demonstrate that the numerical errors due to approximate solution of the MOT matrix system have more dominant impact on DC loop modes in the MOT solution.

  7. On the static loop modes in the marching-on-in-time solution of the time-domain electric field integral equation

    KAUST Repository

    Shi, Yifei; Bagci, Hakan; Lu, Mingyu

    2014-01-01

    When marching-on-in-time (MOT) method is applied to solve the time-domain electric field integral equation, spurious internal resonant and static loop modes are always observed in the solution. The internal resonant modes have recently been studied by the authors; this letter investigates the static loop modes. Like internal resonant modes, static loop modes, in theory, should not be observed in the MOT solution since they do not satisfy the zero initial conditions; their appearance is attributed to numerical errors. It is discussed in this letter that the dependence of spurious static loop modes on numerical errors is substantially different from that of spurious internal resonant modes. More specifically, when Rao-Wilton-Glisson functions and Lagrange interpolation functions are used as spatial and temporal basis functions, respectively, errors due to space-time discretization have no discernible impact on spurious static loop modes. Numerical experiments indeed support this discussion and demonstrate that the numerical errors due to the approximate solution of the MOT matrix system have dominant impact on spurious static loop modes in the MOT solution. © 2014 IEEE.

  8. Evaluating late detection capability against diverse insider adversaries

    International Nuclear Information System (INIS)

    Sicherman, A.

    1987-01-01

    The threat of theft or diversion of special nuclear material (SNM) by insiders is a key concern for safeguards planners. Different types of employees having varying degrees of access to both SNM and safeguards systems pose a difficult challenge for theft detection. Safeguards planners rely on physical security, material control, and accountability to provide detection of a theft attempt. When detection occurs too late to prevent a theft, it is called a late detection or late alarm. Activities or events that many provide late detection usually belong to material control and accountability (MC ampersand A) activities. A model has been developed for evaluating the probability of late detection as a function of time elapsed since the theft. Late detection capability is beneficial if it is timely enough to improve the ability to determine the cause of an alarm, speed recovery of SNM, prevent an incorrect response to a threat demand, or promote assurance that no theft has occurred in the absence of an alarm. The model provides insight into the effectiveness of late detection safeguards components in place and helps to identify areas where the MC ampersand A can be most effectively improved

  9. Keeping Just-in-Time from Being Way-Too-Late or Way-Too-Little.

    Science.gov (United States)

    Hughes, Michael

    2003-01-01

    Describes a systematic approach for the design of training that supports large software implementation projects. Addresses the diverse combination of users, with different needs and time requirements, and outlines how a systematic design approach can be applied to the design and delivery of complex training solutions related to performance…

  10. On spurious resonant modes in the MOT solution of time domain EFIE

    KAUST Repository

    Shi, Yifei

    2013-07-01

    Theoretically, internal resonant modes should not be induced in the marching-on-in-time (MOT) solution of the time domain electric field integral equation since zero initial conditions are enforced at the beginning of time marching and the internal resonant modes do not satisfy these initial conditions. However, these spurious modes are always observed in the MOT solution. It has been conjectured in the past that numerical errors might establish the necessary initial conditions and allow the incident field to induce the internal resonant modes. Systematic numerical experiments carried out in this work prove this conjecture by demonstrating that the internal resonant modes\\' amplitudes are indeed dictated by the numerical errors and the spectrum of the incident field. © 2013 IEEE.

  11. An elementary solution of the Maxwell equations for a time-dependent source

    International Nuclear Information System (INIS)

    Rivera, R; Villarroel, D

    2002-01-01

    We present an elementary solution of the Maxwell equations for a time-dependent source consisting of an infinite solenoid with a current density that increases linearly with time. The geometrical symmetries and the time dependence of the current density make possible a mathematical treatment that does not involve the usual technical difficulties, thus making this presentation suitable for students that are taking a first course in electromagnetism. We also show that the electric field generated by the solenoid can be used to construct an exact solution of the relativistic equation of motion of the electron that takes into account the effect of the radiation. In particular, we derive, in an almost trivial way, the formula for the radiation rate of an electron in circular motion

  12. Approximate solution of space and time fractional higher order phase field equation

    Science.gov (United States)

    Shamseldeen, S.

    2018-03-01

    This paper is concerned with a class of space and time fractional partial differential equation (STFDE) with Riesz derivative in space and Caputo in time. The proposed STFDE is considered as a generalization of a sixth-order partial phase field equation. We describe the application of the optimal homotopy analysis method (OHAM) to obtain an approximate solution for the suggested fractional initial value problem. An averaged-squared residual error function is defined and used to determine the optimal convergence control parameter. Two numerical examples are studied, considering periodic and non-periodic initial conditions, to justify the efficiency and the accuracy of the adopted iterative approach. The dependence of the solution on the order of the fractional derivative in space and time and model parameters is investigated.

  13. Cosmology in time asymmetric extensions of general relativity

    International Nuclear Information System (INIS)

    Leon, Genly; Saridakis, Emmanuel N.

    2015-01-01

    We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a way that the algebra of constraints and local physics remain unchanged. Nevertheless, at cosmological scales these new terms can have significant effects that can alter the universe evolution, both at early and late times, and the freedom in the choice of the involved modification function makes the scenario able to produce a huge class of cosmological behaviors. For basic ansatzes of modification, we perform a detailed dynamical analysis, extracting the stable late-time solutions. Amongst others, we find that the universe can result in dark-energy dominated, accelerating solutions, even in the absence of an explicit cosmological constant, in which the dark energy can be quintessence-like, phantom-like, or behave as an effective cosmological constant. Moreover, it can result to matter-domination, or to a Big Rip, or experience the sequence from matter to dark energy domination. Additionally, in the case of closed curvature, the universe may experience a cosmological bounce or turnaround, or even cyclic behavior. Finally, these scenarios can easily satisfy the observational and phenomenological requirements. Hence, time asymmetric cosmology can be a good candidate for the description of the universe

  14. Solute travel time in the vadose zone under RWMC at INEL

    International Nuclear Information System (INIS)

    Liou, J.C.P.; Tian, J.

    1995-01-01

    Solute transport in the vadose zone under the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL) is considered. The objective is to assess the relative importance of variables involved in modeling the travel time of a conservative solute from ground surface to water table. The vadose zone under RWMC is composed of several layers of basalt flows interceded with sediment layers. The thickness of the layers varies with location. The hydraulic properties also vary. The extents of the variations are large, with standard deviations exceed mean in some instances. The vadose zone is idealized as composed of horizontal layers. Solute transport starts at the ground surface and moves vertically downwards to the water table. The perceived process is one-dimensional. This study used VS2DT, a computer code developed by the US Geological Survey, for simulating solute transport in variably saturated porous media

  15. Resolving Peak Ground Displacements in Real-Time GNSS PPP Solutions

    Science.gov (United States)

    Hodgkinson, K. M.; Mencin, D.; Mattioli, G. S.; Sievers, C.; Fox, O.

    2017-12-01

    The goal of early earthquake warning (EEW) systems is to provide warning of impending ground shaking to the public, infrastructure managers, and emergency responders. Shaking intensity can be estimated using Ground Motion Prediction Equations (GMPEs), but only if site characteristics, hypocentral distance and event magnitude are known. In recent years work has been done analyzing the first few seconds of the seismic P wave to derive event location and magnitude. While initial rupture locations seem to be sufficiently constrained, it has been shown that P-wave magnitude estimates tend to saturate at M>7. Regions where major and great earthquakes occur may therefore be vulnerable to an underestimation of shaking intensity if only P waves magnitudes are used. Crowell et al., (2013) first demonstrated that Peak Ground Displacement (PGD) from long-period surface waves recorded by GNSS receivers could provide a source-scaling relation that does not saturate with event magnitude. GNSS PGD derived magnitudes could improve the accuracy of EEW GMPE calculations. If such a source-scaling method were to be implemented in EEW algorithms it is critical that the noise levels in real-time GNSS processed time-series are low enough to resolve long-period surface waves. UNAVCO currently operates 770 real-time GNSS sites, most of which are located along the North American-Pacific Plate Boundary. In this study, we present an analysis of noise levels observed in the GNSS Precise Point Positioning (PPP) solutions generated and distributed in real-time by UNAVCO for periods from seconds to hours. The analysis is performed using the 770 sites in the real-time network and data collected through July 2017. We compare noise levels determined from various monument types and receiver-antenna configurations. This analysis gives a robust estimation of noise levels in PPP solutions because the solutions analyzed are those that were generated in real-time and thus contain all the problems observed

  16. Exact solutions to the supply chain equations for arbitrary, time-dependent demands

    DEFF Research Database (Denmark)

    Warburton, Roger D.H.; Hodgson, J.P.E.; Nielsen, Erland Hejn

    2014-01-01

    , so users can determine the inventory behavior to any desired precision. To illustrate, we solve the equations for a non-linear, quadratic time-dependence in the demand. For practical use, only a few terms in the series are required, a proposition illustrated by the For All Practical Purposes (FAPP......We study the impact on inventory of an unexpected, non-linear, time-dependent demand and present the exact solutions over time to the supply chain equations without requiring any approximations. We begin by imposing a boundary condition of stability at infinity, from which we derive expressions...... for the estimated demand and the target work in progress when the demand is time-dependent. The resulting inventory equation is solved in terms of the Lambert modes with all of the demand non-linearities confined to the pre-shape function. The series solution is exact, and all terms are reasonably easy to calculate...

  17. Exact Solution of Space-Time Fractional Coupled EW and Coupled MEW Equations Using Modified Kudryashov Method

    International Nuclear Information System (INIS)

    Raslan, K. R.; Ali, Khalid K.; EL-Danaf, Talaat S.

    2017-01-01

    In the present paper, we established a traveling wave solution by using modified Kudryashov method for the space-time fractional nonlinear partial differential equations. The method is used to obtain the exact solutions for different types of the space-time fractional nonlinear partial differential equations such as, the space-time fractional coupled equal width wave equation (CEWE) and the space-time fractional coupled modified equal width wave equation (CMEW), which are the important soliton equations. Both equations are reduced to ordinary differential equations by the use of fractional complex transform and properties of modified Riemann–Liouville derivative. We plot the exact solutions for these equations at different time levels. (paper)

  18. Massive bosons interacting with gravity: No standard solutions in Robertson-Walker space-time

    International Nuclear Information System (INIS)

    Zecca, A.

    2009-01-01

    The problem of the interaction of boson and gravitational field is formulated in the Robertson-Walker space-time. It consist the simultaneous solution of the boson and of the Einstein field equation whose source is the energy momentum tensor of the boson field. By direct verification it is shown that the problem does not admit solutions in the class of massive standard solutions, previously determined, of the boson field equation. Also there cannot be solutions, in case of massive interacting boson, that are superpositions of standard solutions. The case of massless boson field is left open. The result is essentially due to the very special form of the Einstein tensor in Robertson-Walker metric.

  19. On semi-inverse solutions for the time-dependent flows of a second-grade fluid

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available This paper deals with analytical solutions for the time-dependent equations arising in a second-grade fluid. The solutions have been developed by assuming certain forms of the stream function. Expressions for velocity components are obtained for flows in plane polar, axisymmetric cylindrical, and axisymmetric spherical polar coordinates. The obtained solutions are compared with existing results.

  20. Game theory to characterize solutions of a discrete-time Hamilton-Jacobi equation

    International Nuclear Information System (INIS)

    Toledo, Porfirio

    2013-01-01

    We study the behavior of solutions of a discrete-time Hamilton-Jacobi equation in a minimax framework of game theory. The solutions of this problem represent the optimal payoff of a zero-sum game of two players, where the number of moves between the players converges to infinity. A real number, called the critical value, plays a central role in this work; this number is the asymptotic average action of optimal trajectories. The aim of this paper is to show the existence and characterization of solutions of a Hamilton-Jacobi equation for this kind of games

  1. On the Solution of the Eigenvalue Assignment Problem for Discrete-Time Systems

    Directory of Open Access Journals (Sweden)

    El-Sayed M. E. Mostafa

    2017-01-01

    Full Text Available The output feedback eigenvalue assignment problem for discrete-time systems is considered. The problem is formulated first as an unconstrained minimization problem, where a three-term nonlinear conjugate gradient method is proposed to find a local solution. In addition, a cut to the objective function is included, yielding an inequality constrained minimization problem, where a logarithmic barrier method is proposed for finding the local solution. The conjugate gradient method is further extended to tackle the eigenvalue assignment problem for the two cases of decentralized control systems and control systems with time delay. The performance of the methods is illustrated through various test examples.

  2. Global existence of solutions to the Cauchy problem for time-dependent Hartree equations

    International Nuclear Information System (INIS)

    Chadam, J.M.; Glassey, R.T.

    1975-01-01

    The existence of global solutions to the Cauchy problem for time-dependent Hartree equations for N electrons is established. The solution is shown to have a uniformly bounded H 1 (R 3 ) norm and to satisfy an estimate of the form two parallel PSI (t) two parallel/sub H 2 ; less than or equal to c exp(kt). It is shown that ''negative energy'' solutions do not converge uniformly to zero as t → infinity. (U.S.)

  3. Almost Periodicity in Time of Solutions of the Toda Lattice

    OpenAIRE

    Binder, Ilia; Damanik, David; Lukic, Milivoje; VandenBoom, Tom

    2016-01-01

    We study an initial value problem for the Toda lattice with almost periodic initial data. We consider initial data for which the associated Jacobi operator is absolutely continuous and has a spectrum satisfying a Craig-type condition, and show the boundedness and almost periodicity in time and space of solutions.

  4. Geometry-specified troposphere decorrelation for subcentimeter real-time kinematic solutions over long baselines

    Science.gov (United States)

    Li, Bofeng; Feng, Yanming; Shen, Yunzhong; Wang, Charles

    2010-11-01

    Real-time kinematic (RTK) GPS techniques have been extensively developed for applications including surveying, structural monitoring, and machine automation. Limitations of the existing RTK techniques that hinder their applications for geodynamics purposes are twofold: (1) the achievable RTK accuracy is on the level of a few centimeters and the uncertainty of vertical component is 1.5-2 times worse than those of horizontal components and (2) the RTK position uncertainty grows in proportional to the base-to-rover distances. The key limiting factor behind the problems is the significant effect of residual tropospheric errors on the positioning solutions, especially on the highly correlated height component. This paper develops the geometry-specified troposphere decorrelation strategy to achieve the subcentimeter kinematic positioning accuracy in all three components. The key is to set up a relative zenith tropospheric delay (RZTD) parameter to absorb the residual tropospheric effects and to solve the established model as an ill-posed problem using the regularization method. In order to compute a reasonable regularization parameter to obtain an optimal regularized solution, the covariance matrix of positional parameters estimated without the RZTD parameter, which is characterized by observation geometry, is used to replace the quadratic matrix of their "true" values. As a result, the regularization parameter is adaptively computed with variation of observation geometry. The experiment results show that new method can efficiently alleviate the model's ill condition and stabilize the solution from a single data epoch. Compared to the results from the conventional least squares method, the new method can improve the long-range RTK solution precision from several centimeters to the subcentimeter in all components. More significantly, the precision of the height component is even higher. Several geosciences applications that require subcentimeter real-time solutions can

  5. Analytical solutions of time-fractional models for homogeneous Gardner equation and non-homogeneous differential equations

    Directory of Open Access Journals (Sweden)

    Olaniyi Samuel Iyiola

    2014-09-01

    Full Text Available In this paper, we obtain analytical solutions of homogeneous time-fractional Gardner equation and non-homogeneous time-fractional models (including Buck-master equation using q-Homotopy Analysis Method (q-HAM. Our work displays the elegant nature of the application of q-HAM not only to solve homogeneous non-linear fractional differential equations but also to solve the non-homogeneous fractional differential equations. The presence of the auxiliary parameter h helps in an effective way to obtain better approximation comparable to exact solutions. The fraction-factor in this method gives it an edge over other existing analytical methods for non-linear differential equations. Comparisons are made upon the existence of exact solutions to these models. The analysis shows that our analytical solutions converge very rapidly to the exact solutions.

  6. Periodic solutions in reaction–diffusion equations with time delay

    International Nuclear Information System (INIS)

    Li, Li

    2015-01-01

    Spatial diffusion and time delay are two main factors in biological and chemical systems. However, the combined effects of them on diffusion systems are not well studied. As a result, we investigate a nonlinear diffusion system with delay and obtain the existence of the periodic solutions using coincidence degree theory. Moreover, two numerical examples confirm our theoretical results. The obtained results can also be applied in other related fields

  7. Boundedness and almost Periodicity in Time of Solutions of Evolutionary Variational Inequalities

    Science.gov (United States)

    Pankov, A. A.

    1983-04-01

    In this paper existence theorems are obtained for the solutions of abstract parabolic variational inequalities, which are bounded with respect to time (in the Stepanov and L^\\infty norms). The regularity and almost periodicity properties of such solutions are studied. Theorems are also established concerning their solvability in spaces of Besicovitch almost periodic functions. The majority of the results are obtained without any compactness assumptions. Bibliography: 30 titles.

  8. Complete cosmic scenario from inflation to late time acceleration: Nonequilibrium thermodynamics in the context of particle creation

    Science.gov (United States)

    Chakraborty, Subenoy; Saha, Subhajit

    2014-12-01

    The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order nonequilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate, treated as the dissipative effect. In the background of a flat Friedmann-Robertson-Walker (FRW) model, we assume the nonequilibrium thermodynamical process to be isentropic so that the entropy per particle does not change and consequently the dissipative pressure can be expressed linearly in terms of the particle creation rate. Here the dissipative pressure behaves as a dynamical variable having a nonlinear inhomogeneous evolution equation and the entropy flow vector satisfies the second law of thermodynamics. Further, using the Friedmann equations and by proper choice of the particle creation rate as a function of the Hubble parameter, it is possible to show (separately) a transition from the inflationary phase to the radiation era and also from the matter dominated era to late time acceleration. Also, in analogy to analytic continuation, it is possible to show a continuous cosmic evolution from inflation to late time acceleration by adjusting the parameters. It is found that in the de Sitter phase, the comoving entropy increases exponentially with time, keeping entropy per particle unchanged. Subsequently, the above cosmological scenarios have been described from a field theoretic point of view by introducing a scalar field having self-interacting potential. Finally, we make an attempt to show the cosmological phenomenon of particle creation as Hawking radiation, particularly during the inflationary era.

  9. Stability of cylindrical thin shell wormhole during evolution of universe from inflation to late time acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R. [Department of Science, Campus of Bijar, University of Kurdistan,Bijar (Iran, Islamic Republic of); Sepehri, A. [Faculty of Physics, Shahid Bahonar University,P.O. Box 76175, Kerman (Iran, Islamic Republic of)

    2015-03-16

    In this paper, we consider the stability of cylindrical wormholes during evolution of universe from inflation to late time acceleration epochs. We show that there are two types of cylindrical wormholes. The first type is produced at the corresponding point where k black F-strings are transited to BIon configuration. This wormhole transfers energy from extra dimensions into our universe, causes inflation, loses it’s energy and vanishes. The second type of cylindrical wormhole is created by a tachyonic potential and causes a new phase of acceleration. We show that wormhole parameters grow faster than the scale factor in this era, overtake it at ripping time and lead to the destruction of universe at big rip singularity.

  10. GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS

    International Nuclear Information System (INIS)

    Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A.; Maxham, A.; Zhang, B. B.; Zhang, B.; Schady, P.; Holland, S. T.; Kuin, N. P. M.; Oates, S. R.; De Pasquale, M.; Page, K. L.

    2010-01-01

    GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began ∼13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10 5 s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen ∼30% of bursts with optical afterglows that live longer than 10 5 s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

  11. "Real-Time Optical Laboratory Linear Algebra Solution Of Partial Differential Equations"

    Science.gov (United States)

    Casasent, David; Jackson, James

    1986-03-01

    A Space Integrating (SI) Optical Linear Algebra Processor (OLAP) employing space and frequency-multiplexing, new partitioning and data flow, and achieving high accuracy performance with a non base-2 number system is described. Laboratory data on the performance of this system and the solution of parabolic Partial Differential Equations (PDEs) is provided. A multi-processor OLAP system is also described for the first time. It use in the solution of multiple banded matrices that frequently arise is then discussed. The utility and flexibility of this processor compared to digital systolic architectures should be apparent.

  12. Beyond-one-loop quantum gravity action yielding both inflation and late-time acceleration

    Directory of Open Access Journals (Sweden)

    E. Elizalde

    2017-08-01

    Full Text Available A unified description of early-time inflation with the current cosmic acceleration is achieved by means of a new theory that uses a quadratic model of gravity, with the inclusion of an exponential F(R-gravity contribution for dark energy. High-curvature corrections of the theory come from higher-derivative quantum gravity and yield an effective action that goes beyond the one-loop approximation. It is shown that, in this theory, viable inflation emerges in a natural way, leading to a spectral index and tensor-to-scalar ratio that are in perfect agreement with the most reliable Planck results. At low energy, late-time accelerated expansion takes place. As exponential gravity, for dark energy, must be stabilized during the matter and radiation eras, we introduce a curing term in order to avoid nonphysical singularities in the effective equation of state parameter. The results of our analysis are confirmed by accurate numerical simulations, which show that our model does fit the most recent cosmological data for dark energy very precisely.

  13. General exact solution for homogeneous time-dependent self-gravitating perfect fluids

    International Nuclear Information System (INIS)

    Gaete, P.; Hojman, R.

    1988-01-01

    A procedure to obtain the general exact solution of Einstein equations for a self-gravitating spherically-symmetric static perfect fluid obeying an arbitrary equation of state, is applied to time-dependent Kantowsky-Sachs line elements (with spherical, planar and hyperbolic symmetry). As in the static case, the solution is generated by an arbitrary function of the independent variable and its first derivative. To illustrate the results, the whole family of (plane-symmetric) solutions with a ''gamma-law'' equation of state is explicity obtained in terms of simple known functions. It is also shown that, while in the static plane-symmtric line elements, every metric is in one to one correspondence with a ''partner-metric'' (both originated from the same generatrix function), in this case every generatrix function univocally determines one metric. (author) [pt

  14. RDTM solution of Caputo time fractional-order hyperbolic telegraph equation

    Directory of Open Access Journals (Sweden)

    Vineet K. Srivastava

    2013-03-01

    Full Text Available In this study, a mathematical model has been developed for the second order hyperbolic one-dimensional time fractional Telegraph equation (TFTE. The fractional derivative has been described in the Caputo sense. The governing equations have been solved by a recent reliable semi-analytic method known as the reduced differential transformation method (RDTM. The method is a powerful mathematical technique for solving wide range of problems. Using RDTM method, it is possible to find exact solution as well as closed approximate solution of any ordinary or partial differential equation. Three numerical examples of TFTE have been provided in order to check the effectiveness, accuracy and convergence of the method. The computed results are also depicted graphically.

  15. Finite Time Merton Strategy under Drawdown Constraint: A Viscosity Solution Approach

    International Nuclear Information System (INIS)

    Elie, R.

    2008-01-01

    We consider the optimal consumption-investment problem under the drawdown constraint, i.e. the wealth process never falls below a fixed fraction of its running maximum. We assume that the risky asset is driven by the constant coefficients Black and Scholes model and we consider a general class of utility functions. On an infinite time horizon, Elie and Touzi (Preprint, [2006]) provided the value function as well as the optimal consumption and investment strategy in explicit form. In a more realistic setting, we consider here an agent optimizing its consumption-investment strategy on a finite time horizon. The value function interprets as the unique discontinuous viscosity solution of its corresponding Hamilton-Jacobi-Bellman equation. This leads to a numerical approximation of the value function and allows for a comparison with the explicit solution in infinite horizon

  16. Comparative Earth history and Late Permian mass extinction

    Science.gov (United States)

    Knoll, A. H.; Bambach, R. K.; Canfield, D. E.; Grotzinger, J. P.

    1996-01-01

    The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction.

  17. Solution of time dependent atmospheric diffusion equation with a proposed diffusion coefficient

    International Nuclear Information System (INIS)

    Mayhoub, A.B.; Essa, KH.S.M.; Aly, SH.

    2004-01-01

    One-dimensional model for the dispersion of passive atmospheric contaminant (not included chemical reactions) in the atmospheric boundary layer is considered. On the basis of the gradient transfer theory (K-theory), the time dependent diffusion equation represents the dispersion of the pollutants is solved analytically. The solution depends on diffusion coefficient K', which is expressed in terms of the friction velocity 'u the vertical coordinate -L and the depth of the mixing layer 'h'. The solution is obtained to either the vertical coordinate 'z' is less or greater than the mixing height 'h'. The obtained solution may be applied to study the atmospheric dispersion of pollutants

  18. Late prematurity: a systematic review

    Directory of Open Access Journals (Sweden)

    Luís Carlos Machado Júnior

    2014-06-01

    Full Text Available Objective: this study aimed to review the literature regarding late preterm births (34 weeks to 36 weeks and 6 days of gestation in its several aspects. Sources: the MEDLINE, LILACS, and Cochrane Library databases were searched, and the references of the articles retrieved were also used, with no limit of time. Data synthesis: numerous studies showed a recent increase in late preterm births. In all series, late preterm comprised the majority of preterm births. Studies including millions of births showed a strong association between late preterm birth and neonatal mortality. A higher mortality in childhood and among young adults was also observed. Many studies found an association with several neonatal complications, and also with long-term disorders and sequelae: breastfeeding problems, cerebral palsy, asthma in childhood, poor school performance, schizophrenia, and young adult diabetes. Some authors propose strategies to reduce late preterm birth, or to improve neonatal outcome: use of antenatal corticosteroids, changes in some of the guidelines for early delivery in high-risk pregnancies, and changes in neonatal care for this group. Conclusions: numerous studies show greater mortality and morbidity in late preterm infants compared with term infants, in addition to long-term disorders. More recent studies evaluated strategies to improve the outcomes of these neonates. Further studies on these strategies are needed.

  19. Real-time optical laboratory solution of parabolic differential equations

    Science.gov (United States)

    Casasent, David; Jackson, James

    1988-01-01

    An optical laboratory matrix-vector processor is used to solve parabolic differential equations (the transient diffusion equation with two space variables and time) by an explicit algorithm. This includes optical matrix-vector nonbase-2 encoded laboratory data, the combination of nonbase-2 and frequency-multiplexed data on such processors, a high-accuracy optical laboratory solution of a partial differential equation, new data partitioning techniques, and a discussion of a multiprocessor optical matrix-vector architecture.

  20. Principal and nonprincipal solutions of symplectic dynamic systems on time scales

    Directory of Open Access Journals (Sweden)

    Ondrej Dosly

    2000-01-01

    Full Text Available We establish the concept of the principal and nonprincipal solution for the so-called symplectic dynamic systems on time scales. We also present a brief survey of the history of these concept for differential and difference equations.

  1. Multiple determinants controlling activation of yeast replication origins late in S phase.

    Science.gov (United States)

    Friedman, K L; Diller, J D; Ferguson, B M; Nyland, S V; Brewer, B J; Fangman, W L

    1996-07-01

    Analysis of a 131-kb segment of the left arm of yeast chromosome XIV beginning 157 kb from the telomere reveals four highly active origins of replication that initiate replication late in S phase. Previous work has shown that telomeres act as determinants for late origin activation. However, at least two of the chromosome XIV origins maintain their late activation time when located on large circular plasmids, indicating that late replication is independent of telomeres. Analysis of the replication time of plasmid derivatives containing varying amounts of chromosome XIV DNA show that a minimum of three chromosomal elements, distinct from each tested origin, contribute to late activation time. These late determinants are functionally equivalent, because duplication of one set of contributing sequences can compensate for the removal of another set. Furthermore, insertion of an origin that is normally early activated into this domain results in a shift to late activation, suggesting that the chromosome XIV origins are not unique in their ability to respond to the late determinants.

  2. Nonlinear recurrent neural networks for finite-time solution of general time-varying linear matrix equations.

    Science.gov (United States)

    Xiao, Lin; Liao, Bolin; Li, Shuai; Chen, Ke

    2018-02-01

    In order to solve general time-varying linear matrix equations (LMEs) more efficiently, this paper proposes two nonlinear recurrent neural networks based on two nonlinear activation functions. According to Lyapunov theory, such two nonlinear recurrent neural networks are proved to be convergent within finite-time. Besides, by solving differential equation, the upper bounds of the finite convergence time are determined analytically. Compared with existing recurrent neural networks, the proposed two nonlinear recurrent neural networks have a better convergence property (i.e., the upper bound is lower), and thus the accurate solutions of general time-varying LMEs can be obtained with less time. At last, various different situations have been considered by setting different coefficient matrices of general time-varying LMEs and a great variety of computer simulations (including the application to robot manipulators) have been conducted to validate the better finite-time convergence of the proposed two nonlinear recurrent neural networks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Positive solution of a time and energy dependent neutron transport problem

    International Nuclear Information System (INIS)

    Pao, C.V.

    1975-01-01

    A constructive method is given for the determination of a solution and an existence--uniqueness theorem for some nonlinear time and energy dependent neutron transport problems, including the linear transport system. The geometry of the medium under consideration is allowed to be either bounded or unbounded which includes the geometry of a finite or infinite cylinder, a half-space and the whole space R/subm/ (m=1,2,center-dotcenter-dotcenter-dot). Our approach to the problem is by successive approximation which leads to various recursion formulas for the approximations in terms of explicit integrations. It is shown under some Lipschitz conditions on the nonlinear functions, which describe the process of neutrons absorption, fission, and scattering, that the sequence of approximations converges to a unique positive solution. Since these conditions are satisfied by the linear transport equation, all the results for the nonlinear system are valid for the linear transport problem. In the general nonlinear problem, the existence of both local and global solutions are discussed, and an iterative process for the construction of the solution is given

  4. Constructing and predicting solitary pattern solutions for nonlinear time-fractional dispersive partial differential equations

    Science.gov (United States)

    Arqub, Omar Abu; El-Ajou, Ahmad; Momani, Shaher

    2015-07-01

    Building fractional mathematical models for specific phenomena and developing numerical or analytical solutions for these fractional mathematical models are crucial issues in mathematics, physics, and engineering. In this work, a new analytical technique for constructing and predicting solitary pattern solutions of time-fractional dispersive partial differential equations is proposed based on the generalized Taylor series formula and residual error function. The new approach provides solutions in the form of a rapidly convergent series with easily computable components using symbolic computation software. For method evaluation and validation, the proposed technique was applied to three different models and compared with some of the well-known methods. The resultant simulations clearly demonstrate the superiority and potentiality of the proposed technique in terms of the quality performance and accuracy of substructure preservation in the construct, as well as the prediction of solitary pattern solutions for time-fractional dispersive partial differential equations.

  5. Pathological review of late cerebral radionecrosis

    International Nuclear Information System (INIS)

    Yoshii, Yoshihiko

    2008-01-01

    Late cerebral radionecrosis may be considered to be a specific chronic inflammatory response, although it is unknown whether the initial damage by brain irradiation is to an endothelial cell or a glial cell. I discuss the pathological specificity of late cerebral radionecrosis by studying the published literature and a case that I experienced. In late cerebral radionecrosis, there are typical coagulation necrosis areas containing fibrinoid necrosis with occlusion of the lumina and poorly active inflammatory areas with many inflammatory ghost cells, focal perivascular lymphocytes, hyalinized vessels, and telangiectatic vascularization near and in the necrotic tissue, and more active inflammatory areas formed as a partial rim of the reactive zone by perivascular lymphocytes, much vascularization, and glial fibrillary acidic protein (GFAP)-positive astrocytes at the corticomedullary border adjacent to necrotic tissue in the white matter. It is difficult to believe that coagulation necrosis occurs without first disordering the vascular endothelial cells because fibrinoid necrosis is a main feature and a diffusely multiple lesion in late cerebral radionecrosis. Because various histological findings do develop, progress, and extend sporadically at different areas and times in the irradiated field of the brain for a long time after radiation, uncontrolled chronic inflammation containing various cytokine secretions may also play a key role in progression of this radionecrosis. Evaluation of the mechanism of the development/aggravation of late cerebral radionecrosis requires a further study for abnormal cytokine secretions and aberrant inflammatory reactions. (author)

  6. On solutions of nonlinear time-space fractional Swift–Hohenberg equation: A comparative study

    Directory of Open Access Journals (Sweden)

    Najeeb Alam Khan

    2014-03-01

    Full Text Available In this paper, a comparison for the solutions of nonlinear Swift–Hohenberg equation with time-space fractional derivatives has been analyzed. The two most promising techniques, fractional variational iteration method (FVIM and the homotopy analysis method have been chosen for the comparison. The two different definitions of fractional calculus are considered to solve time-fractional derivative separately for the considered approaches. Also, the space fractional derivative is described in the Reisz sense. Analytical and numerical solutions for various combinations of the parameters are obtained. Numerical comparisons have been made for different values of parameters and depicted.

  7. Paradoxical physiological transitions from aging to late life in Drosophila.

    Science.gov (United States)

    Shahrestani, Parvin; Quach, Julie; Mueller, Laurence D; Rose, Michael R

    2012-02-01

    In a variety of organisms, adulthood is divided into aging and late life, where aging is a period of exponentially increasing mortality rates and late life is a period of roughly plateaued mortality rates. In this study we used ∼57,600 Drosophila melanogaster from six replicate populations to examine the physiological transitions from aging to late life in four functional characters that decline during aging: desiccation resistance, starvation resistance, time spent in motion, and negative geotaxis. Time spent in motion and desiccation resistance declined less quickly in late life compared to their patterns of decline during aging. Negative geotaxis declined at a faster rate in late life compared to its rate of decline during aging. These results yield two key findings: (1) Late-life physiology is distinct from the physiology of aging, in that there is not simply a continuation of the physiological trends which characterize aging; and (2) late life physiology is complex, in that physiological characters vary with respect to their stabilization, deceleration, or acceleration in the transition from aging to late life. These findings imply that a correct understanding of adulthood requires identifying and appropriately characterizing physiology during properly delimited late-life periods as well as aging periods.

  8. Effect of solution heat treatment time on a rheocast Al-Zn-Mg-Cu alloy

    CSIR Research Space (South Africa)

    Mazibuko, NE

    2011-06-01

    Full Text Available During rheo-high pressure die casting (R-HPDC) of Al-Zn-Mg-Cu alloys a coarse eutectic phase is formed. This eutectic phase is difficult to take into solution because of its size and it would require longer solution heat treatment times...

  9. Quantification of late complications after radiation therapy

    International Nuclear Information System (INIS)

    Jung, Horst; Beck-Bornholdt, Hans-Peter; Svoboda, Vladimir; Alberti, Winfried; Herrmann, Thomas

    2001-01-01

    Background: An increasing number of patients survive cancer after having received radiation therapy. Therefore, the occurrence of late normal tissue complications among long-term survivors is of particular concern. Methods: Sixty-three patients treated by radical surgery and irradiation for rectal carcinoma were subjected to an unconventional sandwich therapy. Preoperative irradiation was given in four fractions of 5 Gy each applied within 2 or 3 days; postoperative irradiation consisted mostly of 15x2 Gy (range, 20-40 Gy). A considerable proportion of these patients developed severe late complications (Radiother Oncol 53 (1999) 177). The data allowed a detailed analysis of complication kinetics, leading to a new model which was tested using data from the literature. Results: Data on late complications were obtained for eight different organs with a follow-up of up to 10 years. For the various organs, the percentage of patients being free from late complications, plotted as a function of time after start of radiation therapy, was adequately described by exponential regression. From the fit, the parameter p a was obtained, which is the percentage of patients at risk in a given year of developing a complication in a given organ during that year. The rate p a remained about constant with time. Following sandwich therapy, the annual incidence of complications in the bladder, ileum, lymphatic and soft tissue, and ureters was about the same (p a =10-14%/year), whereas complications in bone or dermis occurred at lower rates (4.7 or 7.5%/year, respectively). Discussion: Numerous data sets collected from published reports were analyzed in the same way. Many of the data sets studied were from patients in a series where there was a high incidence of late effects. Three types of kinetics for the occurrence of late effects after radiotherapy were identified: Type 1, purely exponential kinetics; Type 2, exponential kinetics, the slope of which decreased exponentially with time

  10. Derivation and solution of a time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter

    International Nuclear Information System (INIS)

    Esrick, M.A.

    1981-01-01

    A time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter is derived from the Gor'kov equations. Three types of traveling wave solutions of the equation are discussed. The phases and amplitudes of these solutions propagate at different speeds. The first type of solution has an amplitude that propagates as a soliton and it is suggested that this solution might correspond to the recently observed propagating collective modes of the order parameter. The amplitude of the second type of solution propagates as a periodic disturbance in space and time. It is suggested that this type of solution might explain the recently observed multiple values of the superconductor energy gap as well as the spatially inhomogenous superconducting state. The third type of solution, which is of a more general character, might provide some insight into non-periodic, inhomogeneous states occuring in superconductors. It is also proposed that quasiparticle injection and microwave irradiation might generate soliton-like disturbances in superconductors

  11. Asymptotics for Large Time of Global Solutions to the Generalized Kadomtsev-Petviashvili Equation

    Science.gov (United States)

    Hayashi, Nakao; Naumkin, Pavel I.; Saut, Jean-Claude

    We study the large time asymptotic behavior of solutions to the generalized Kadomtsev-Petviashvili (KP) equations where σ= 1 or σ=- 1. When ρ= 2 and σ=- 1, (KP) is known as the KPI equation, while ρ= 2, σ=+ 1 corresponds to the KPII equation. The KP equation models the propagation along the x-axis of nonlinear dispersive long waves on the surface of a fluid, when the variation along the y-axis proceeds slowly [10]. The case ρ= 3, σ=- 1 has been found in the modeling of sound waves in antiferromagnetics [15]. We prove that if ρ>= 3 is an integer and the initial data are sufficiently small, then the solution u of (KP) satisfies the following estimates: for all t∈R, where κ= 1 if ρ= 3 and κ= 0 if ρ>= 4. We also find the large time asymptotics for the solution.

  12. The Transition of a Type IIL Supernova into a Supernova Remnant: Late-time Observations of SN 2013by

    Energy Technology Data Exchange (ETDEWEB)

    Black, C. S.; Fesen, R. A. [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Milisavljevic, D.; Patnaude, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Margutti, R. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Parker, S. [Parkdale Observatory, 225 Warren Road, RDl Oxford, Canterbury 7495 (New Zealand)

    2017-10-10

    We present early-time Swift and Chandra X-ray data along with late-time optical and near-infrared observations of SN 2013by, a Type IIL supernova (SN) that occurred in the nearby spiral galaxy ESO 138−G10 ( D ∼ 14.8 Mpc). Optical and NIR photometry and spectroscopy follow the late-time evolution of the SN from days +89 to +457 post maximum brightness. The optical spectra and X-ray light curves are consistent with the picture of an SN having prolonged interaction with circumstellar material (CSM) that accelerates the transition from SN to supernova remnant (SNR). Specifically, we find SN 2013by’s H α profile exhibits significant broadening (∼10,000 km s{sup −1}) on day +457, the likely consequence of high-velocity, H-rich material being excited by a reverse shock. A relatively flat X-ray light curve is observed that cannot be modeled using Inverse Compton scattering processes alone, but requires an additional energy source most likely originating from the SN-CSM interaction. In addition, we see the first overtone of CO emission near 2.3 μ m on day +152, signaling the formation of molecules and dust in the SN ejecta and is the first time CO has been detected in a Type IIL SN. We compare SN 2013by with Type IIP SNe, whose spectra show the rarely observed SN-to-SNR transition in varying degrees and conclude that Type IIL SNe may enter the remnant phase at earlier epochs than their Type IIP counterparts.

  13. Analytical Solutions for Multi-Time Scale Fractional Stochastic Differential Equations Driven by Fractional Brownian Motion and Their Applications

    OpenAIRE

    Xiao-Li Ding; Juan J. Nieto

    2018-01-01

    In this paper, we investigate analytical solutions of multi-time scale fractional stochastic differential equations driven by fractional Brownian motions. We firstly decompose homogeneous multi-time scale fractional stochastic differential equations driven by fractional Brownian motions into independent differential subequations, and give their analytical solutions. Then, we use the variation of constant parameters to obtain the solutions of nonhomogeneous multi-time scale fractional stochast...

  14. New Exact Solutions of Time Fractional Gardner Equation by Using New Version of F -Expansion Method

    International Nuclear Information System (INIS)

    Pandir, Yusuf; Duzgun, Hasan Huseyin

    2017-01-01

    In this article, we consider analytical solutions of the time fractional derivative Gardner equation by using the new version of F-expansion method. With this proposed method multiple Jacobi elliptic functions are situated in the solution function. As a result, various exact analytical solutions consisting of single and combined Jacobi elliptic functions solutions are obtained. (paper)

  15. LATE VISION: PROCESSES AND EPISTEMIC STATUS

    Directory of Open Access Journals (Sweden)

    Athanassios eRaftopoulos

    2011-12-01

    Full Text Available In this paper, I examine the processes that occur in late vision and address the problem of whether late vision should be construed as a properly speaking perceptual stage, or as a thought-like discursive stage. Specifically, I argue that late vision, its (partly conceptual nature notwithstanding, neither is constituted by nor does it implicate what I call pure thoughts, that is, propositional structures that are formed in the cognitive areas of the brain through, and participate in, discursive reasoning and inferences. At the same time, the output of late vision, namely an explicit belief concerning the identity and category membership of an object (that is, a recognitional belief or its features, eventually enters into discursive reasoning. Using Jackendoff’s distinction between visual awareness, which characterizes perception, and visual understanding, which characterizes pure thought, I claim that the contents of late vision belong to visual awareness and not to visual understanding and that although late vision implicates beliefs, either implicit or explicit, these beliefs are hybrid visual/conceptual constructs and not pure thoughts. Distinguishing between these hybrid representations and pure thoughts and delineating the nature of the representations of late vision lays the ground for examining, among other things, the process of conceptualization that occurs in visual processing and the way concepts modulate perceptual content affecting either its representational or phenomenal character. I also do not discuss the epistemological relations between the representations of late vision and the perceptual judgments they ‘support’, or ‘guide’ or ‘render possible’ or ‘evidence’ or ‘entitle’. However, the specification of the epistemology of late vision lays the ground for attacking that problem as well.

  16. Recursive solution for dynamic response of one-dimensional structures with time-dependent boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Abadi, Mohammad Tahaye [Aerospace Research Institute, Tehran (Iran, Islamic Republic of)

    2015-10-15

    A recursive solution method is derived for the transient response of one-dimensional structures subjected to the general form of time dependent boundary conditions. Unlike previous solution methods that assumed the separation of variables, the present method involves formulating and solving the dynamic problems using the summation of two single-argument functions satisfying the motion equation. Based on boundary and initial conditions, a recursive procedure is derived to determine the single-argument functions. Such a procedure is applied to the general form of boundary conditions, and an analytical solution is derived by solving the recursive equation. The present solution method is implemented for base excitation problems, and the results are compared with those of the previous analytical solution and the Finite element (FE) analysis. The FE results converge to the present analytical solution, although considerable error is found in predicting a solution method on the basis of the separation of variables. The present analytical solution predicts the transient response for wave propagation problems in broadband excitation frequencies.

  17. Recursive solution for dynamic response of one-dimensional structures with time-dependent boundary conditions

    International Nuclear Information System (INIS)

    Abadi, Mohammad Tahaye

    2015-01-01

    A recursive solution method is derived for the transient response of one-dimensional structures subjected to the general form of time dependent boundary conditions. Unlike previous solution methods that assumed the separation of variables, the present method involves formulating and solving the dynamic problems using the summation of two single-argument functions satisfying the motion equation. Based on boundary and initial conditions, a recursive procedure is derived to determine the single-argument functions. Such a procedure is applied to the general form of boundary conditions, and an analytical solution is derived by solving the recursive equation. The present solution method is implemented for base excitation problems, and the results are compared with those of the previous analytical solution and the Finite element (FE) analysis. The FE results converge to the present analytical solution, although considerable error is found in predicting a solution method on the basis of the separation of variables. The present analytical solution predicts the transient response for wave propagation problems in broadband excitation frequencies.

  18. Improvements to the transient solution in the PANTHER space-time code

    International Nuclear Information System (INIS)

    Kutt, P.K.; Knight, M.P.

    1993-01-01

    The three dimensional, two-group, nodal diffusion code PANTHER has been developed for the analysis of almost all thermal reactor types [pressurized water reactor (PWR), boiling water reactor, VVER, RBMK, advanced gas-cooled reactor, MAGNOX]. It can perform a comprehensive range of calculations for fuel management, operational support including on-line application, and transient analysis. Transient results for a number of light water reactor (LWR) benchmark problems have been reported previously. This paper outlines some recent developments of the transient solution in PANTHER, showing results for two LWR benchmark problems. Recently, PANTHER results have been accepted as the reference solutions for a Nuclear Energy Agency Committee on Reactor Physics (NEACRP) rod ejection benchmark Unlike previous simplified rod ejection benchmarks, it represents a real PWR with a detailed thermal model and cross sections dependent on boron, fuel temperature, and water density and temperature. This reference solution was computed with fine time steps

  19. LATE-TIME LIGHT CURVES OF TYPE II SUPERNOVAE: PHYSICAL PROPERTIES OF SUPERNOVAE AND THEIR ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Masaaki; Meixner, Margaret; Panagia, Nino [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Fabbri, Joanna; Barlow, Michael J.; Wesson, Roger [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Clayton, Geoffrey C.; Andrews, Jennifer E. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Gallagher, Joseph S. [Department of Mathematics, Physics, and Computer Science, Raymond Walters College, 9555 Plain field Rd., Blue Ash, OH 45236 (United States); Sugerman, Ben E. K. [Department of Physics and Astronomy, Goucher College, 1021 Dulaney Valley Road, Baltimore, MD 21204 (United States); Ercolano, Barbara [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, 81679 Muenchen (Germany); Welch, Douglas, E-mail: otsuka@stsci.edu, E-mail: otsuka@asiaa.sinica.edu.tw [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada)

    2012-01-01

    We present BVRIJHK-band photometry of six core-collapse supernovae, SNe 1999bw, 2002hh, 2003gd, 2004et, 2005cs, and 2006bc, measured at late epochs (>2 yr) based on the Hubble Space Telescope (HST), and the Gemini North, and WIYN telescopes. We also show the JHK light curves of supernova impostor SN 2008S up to day 575 because it was serendipitously in our SN 2002hh field of view. Of our 43 HST observations in total, 36 observations are successful in detecting the light from the SNe alone and measuring magnitudes of all the targets. HST observations show a resolved scattered light echo around SN 2003gd at day 1520 and around SN 2002hh at day 1717. Our Gemini and WIYN observations detected SNe 2002hh and 2004et as well. Combining our data with previously published data, we show VRIJHK-band light curves and estimate decline magnitude rates at each band in four different phases. Our prior work on these light curves and other data indicate that dust is forming in our targets from days {approx}300 to 400, supporting SN dust formation theory. In this paper we focus on other physical properties derived from late-time light curves. We estimate {sup 56}Ni masses for our targets (0.5-14 Multiplication-Sign 10{sup -2} M{sub Sun }) from the bolometric light curve of each of days {approx}150-300 using SN 1987A as a standard (7.5 Multiplication-Sign 10{sup -2} M{sub Sun }). The flattening or sometimes increasing fluxes in the late-time light curves of SNe 2002hh, 2003gd, 2004et, and 2006bc indicate the presence of light echoes. We estimate the circumstellar hydrogen density of the material causing the light echo and find that SN 2002hh is surrounded by relatively dense materials (n(H) >400 cm{sup -3}) and SNe 2003gd and 2004et have densities more typical of the interstellar medium ({approx}1 cm{sup -3}). We analyze the sample as a whole in the context of physical properties derived in prior work. The {sup 56}Ni mass appears well correlated with progenitor mass with a slope of 0

  20. Climate Change. Solutions for Australia

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, T.; Hoegh-Guldberg, O.; Karoly, D.; Lowe, I.; McMichael, T.; Mitchell, C.; Pearman, G.; Scaife, P.; Reynolds, A. (eds.)

    2004-06-01

    The Australian Climate Group was convened in late 2003 by WWF Australia and the Insurance Australia Group (IAG) in response to the increasing need for action on climate change in Australia. This group proposes a set of solutions to lower the risk that climate change will reach a dangerous level.

  1. THE NEW SOLUTION OF TIME FRACTIONAL WAVE EQUATION WITH CONFORMABLE FRACTIONAL DERIVATIVE DEFINITION

    OpenAIRE

    Çenesiz, Yücel; Kurt, Ali

    2015-01-01

    – In this paper, we used new fractional derivative definition, the conformable fractional derivative, for solving two and three dimensional time fractional wave equation. This definition is simple and very effective in the solution procedures of the fractional differential equations that have complicated solutions with classical fractional derivative definitions like Caputo, Riemann-Liouville and etc. The results show that conformable fractional derivative definition is usable and convenient ...

  2. On Analytical Solutions of f(R) Modified Gravity Theories in FLRW Cosmologies

    Science.gov (United States)

    Domazet, Silvije; Radovanović, Voja; Simonović, Marko; Štefančić, Hrvoje

    2013-02-01

    A novel analytical method for f(R) modified theories without matter in Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes is introduced. The equation of motion for the scale factor in terms of cosmic time is reduced to the equation for the evolution of the Ricci scalar R with the Hubble parameter H. The solution of equation of motion for actions of the form of power law in Ricci scalar R is presented with a detailed elaboration of the action quadratic in R. The reverse use of the introduced method is exemplified in finding functional forms f(R), which leads to specified scale factor functions. The analytical solutions are corroborated by numerical calculations with excellent agreement. Possible further applications to the phases of inflationary expansion and late-time acceleration as well as f(R) theories with radiation are outlined.

  3. Accessible high performance computing solutions for near real-time image processing for time critical applications

    Science.gov (United States)

    Bielski, Conrad; Lemoine, Guido; Syryczynski, Jacek

    2009-09-01

    High Performance Computing (HPC) hardware solutions such as grid computing and General Processing on a Graphics Processing Unit (GPGPU) are now accessible to users with general computing needs. Grid computing infrastructures in the form of computing clusters or blades are becoming common place and GPGPU solutions that leverage the processing power of the video card are quickly being integrated into personal workstations. Our interest in these HPC technologies stems from the need to produce near real-time maps from a combination of pre- and post-event satellite imagery in support of post-disaster management. Faster processing provides a twofold gain in this situation: 1. critical information can be provided faster and 2. more elaborate automated processing can be performed prior to providing the critical information. In our particular case, we test the use of the PANTEX index which is based on analysis of image textural measures extracted using anisotropic, rotation-invariant GLCM statistics. The use of this index, applied in a moving window, has been shown to successfully identify built-up areas in remotely sensed imagery. Built-up index image masks are important input to the structuring of damage assessment interpretation because they help optimise the workload. The performance of computing the PANTEX workflow is compared on two different HPC hardware architectures: (1) a blade server with 4 blades, each having dual quad-core CPUs and (2) a CUDA enabled GPU workstation. The reference platform is a dual CPU-quad core workstation and the PANTEX workflow total computing time is measured. Furthermore, as part of a qualitative evaluation, the differences in setting up and configuring various hardware solutions and the related software coding effort is presented.

  4. The problem of complex eigensystems in the semianalytical solution for advancement of time in solute transport simulations: a new method using real arithmetic

    Science.gov (United States)

    Umari, Amjad M.J.; Gorelick, Steven M.

    1986-01-01

    In the numerical modeling of groundwater solute transport, explicit solutions may be obtained for the concentration field at any future time without computing concentrations at intermediate times. The spatial variables are discretized and time is left continuous in the governing differential equation. These semianalytical solutions have been presented in the literature and involve the eigensystem of a coefficient matrix. This eigensystem may be complex (i.e., have imaginary components) due to the asymmetry created by the advection term in the governing advection-dispersion equation. Previous investigators have either used complex arithmetic to represent a complex eigensystem or chosen large dispersivity values for which the imaginary components of the complex eigenvalues may be ignored without significant error. It is shown here that the error due to ignoring the imaginary components of complex eigenvalues is large for small dispersivity values. A new algorithm that represents the complex eigensystem by converting it to a real eigensystem is presented. The method requires only real arithmetic.

  5. Cost-Effective Video Filtering Solution for Real-Time Vision Systems

    Directory of Open Access Journals (Sweden)

    Karl Martin

    2005-08-01

    Full Text Available This paper presents an efficient video filtering scheme and its implementation in a field-programmable logic device (FPLD. Since the proposed nonlinear, spatiotemporal filtering scheme is based on order statistics, its efficient implementation benefits from a bit-serial realization. The utilization of both the spatial and temporal correlation characteristics of the processed video significantly increases the computational demands on this solution, and thus, implementation becomes a significant challenge. Simulation studies reported in this paper indicate that the proposed pipelined bit-serial FPLD filtering solution can achieve speeds of up to 97.6 Mpixels/s and consumes 1700 to 2700 logic cells for the speed-optimized and area-optimized versions, respectively. Thus, the filter area represents only 6.6 to 10.5% of the Altera STRATIX EP1S25 device available on the Altera Stratix DSP evaluation board, which has been used to implement a prototype of the entire real-time vision system. As such, the proposed adaptive video filtering scheme is both practical and attractive for real-time machine vision and surveillance systems as well as conventional video and multimedia applications.

  6. Aetiology, timing and clinical predictors of early vs. late readmission following index hospitalization for acute heart failure: insights from ASCEND-HF.

    Science.gov (United States)

    Fudim, Marat; O'Connor, Christopher M; Dunning, Allison; Ambrosy, Andrew P; Armstrong, Paul W; Coles, Adrian; Ezekowitz, Justin A; Greene, Stephen J; Metra, Marco; Starling, Randall C; Voors, Adriaan A; Hernandez, Adrian F; Michael Felker, G; Mentz, Robert J

    2018-02-01

    Patients hospitalized for heart failure (HF) are at high risk for 30-day readmission. This study sought to examine the timings and causes of readmission within 30 days of an HF hospitalization. Timing and cause of readmission in the ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide and Decompensated Heart Failure) trial were assessed. Early and late readmissions were defined as admissions occurring within 0-7 days and 8-30 days post-discharge, respectively. Patients who died in hospital or remained hospitalized at day 30 post-randomization were excluded. Patients were compared by timing and cause of readmission. Logistic and Cox proportional hazards regression analyses were used to identify independent risk factors for early vs. late readmission and associations with 180-day outcomes. Of the 6584 patients (92%) in the ASCEND-HF population included in this analysis, 751 patients (11%) were readmitted within 30 days for any cause. Overall, 54% of readmissions were for non-HF causes. The median time to rehospitalization was 11 days (interquartile range: 6-18 days) and 33% of rehospitalizations occurred by day 7. Rehospitalization within 30 days was independently associated with increased risk for 180-day all-cause death [hazard ratio (HR) 2.38, 95% confidence interval (CI) 1.93-2.94; P readmission (HR 0.99, 95% CI 0.67-1.45; P = 0.94). In this hospitalized HF trial population, a significant majority of 30-day readmissions were for non-HF causes and one-third of readmissions occurred in the first 7 days. Early and late readmissions within the 30-day timeframe were associated with similarly increased risk for death. Continued efforts to optimize multidisciplinary transitional care are warranted to improve rates of early readmission. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.

  7. The reliable solution and computation time of variable parameters Logistic model

    OpenAIRE

    Pengfei, Wang; Xinnong, Pan

    2016-01-01

    The reliable computation time (RCT, marked as Tc) when applying a double precision computation of a variable parameters logistic map (VPLM) is studied. First, using the method proposed, the reliable solutions for the logistic map are obtained. Second, for a time-dependent non-stationary parameters VPLM, 10000 samples of reliable experiments are constructed, and the mean Tc is then computed. The results indicate that for each different initial value, the Tcs of the VPLM are generally different...

  8. Intraindividual comparison of T1 relaxation times after gadobutrol and Gd-DTPA administration for cardiac late enhancement imaging

    Energy Technology Data Exchange (ETDEWEB)

    Doeblin, Patrick, E-mail: Patrick.doeblin@charite.de [Department of Cardiology, Charité – Universitätsmedizin Berlin, Charité Campus Benjamin Franklin, Berlin (Germany); Schilling, Rene, E-mail: rene.schilling@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Wagner, Moritz, E-mail: moritz.wagner@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Luhur, Reny, E-mail: renyluhur@yahoo.com [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Huppertz, Alexander, E-mail: alexander.huppertz@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Imaging Science Institute, Charité, Berlin (Germany); Hamm, Bernd, E-mail: bernd.hamm@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Taupitz, Matthias, E-mail: matthias.taupitz@harite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); and others

    2014-04-15

    Purpose: To evaluate T1-relaxation times of chronic myocardial infarction (CMI) using gadobutrol and gadopentetate dimeglumine (Gd-DTPA) over time and to determine the optimal imaging window for late enhancement imaging with both contrast agents. Material and methods: Twelve patients with CMI were prospectively included and examined on a 1.5 T magnetic resonance (MR) system using relaxivity-adjusted doses of gadobutrol (0.15 mmol/kg) and Gd-DTPA (0.2 mmol/kg) in random order. T1-relaxation times of remote myocardium (RM), infarcted myocardium (IM), and left ventricular cavity (LVC) were assessed from short-axis TI scout imaging using the Look–Locker approach and compared intraindividually using a Wilcoxon paired signed-rank test (α < 0.05). Results: Within 3 min of contrast agent administration (CA), IM showed significantly lower T1-relaxation times than RM with both contrast agents, indicating beginning cardiac late enhancement. Differences between gadobutrol and Gd-DTPA in T1-relaxation times of IM and RM were statistically not significant through all time points. However, gadobutrol led to significantly higher T1-relaxation times of LVC than Gd-DTPA from 6 to 9 min (220 ± 15 ms vs. 195 ± 30 ms p < 0.01) onwards, resulting in a significantly greater ΔT1 of IM to LVC at 9–12 min (−20 ± 35 ms vs. 0 ± 35 ms, p < 0.05) and 12–15 min (−25 ± 45 ms vs. −10 ± 60 ms, p < 0.05). Using Gd-DTPA, comparable ΔT1 values were reached only after 25–35 min. Conclusion: This study indicates good delineation of IM to RM with both contrast agents as early as 3 min after administration. However, we found significant differences in T1 relaxation times with greater ΔT1 IM–LVC using 0.15 mmol/kg gadobutrol compared to 0.20 mmol/kg Gd-DTPA after 9–15 min post-CA suggesting earlier differentiability of IM and LVC using gadobutrol.

  9. Part-time employment in Jordan as a nursing policy solution.

    Science.gov (United States)

    Al-Motlaq, M; Azar, N; Squires, A

    2017-03-01

    Explore the potential of a part-time work option for nurses as a strategy for managing domestic markets in Jordan by examining perceptions of working nurses and nursing students in the context of current social and cultural variables. Unemployment among Jordanian nurses has become a reality in recent years. However, labor markets literature in nursing rarely studies what kind of policy responses should occur during a surplus of nurses. A cross-sectional design structured the study. The perceptions of nurses and students were measured through a questionnaire developed specifically for the purpose of this exploratory study. Both nurses (n = 51) and students (n = 56) supported the introduction of the new suggested part-time option. However, students were more willing to start working or transfer into part-time work, take payment on hourly basis, and support colleagues to transfer into part-time work. Different solutions were also suggested by participants. The results were useful for providing the foundational data to further study the viability of a part-time work option for Jordanian nurses. The results show how optimistic current and future Jordanian nurses are regarding this employment option. For countries that may need to diversify their employment models due to excess supply of nurses and to address gender imbalances, this work may help inform policy development. Both employed and unemployed nurses will benefit if health care managers consider its application. The flexibility of this option may help improve the quality of life of many nurses. The results of this study provide nursing leaders and managers with foundational evidence that may be applicable in the Jordanian health sector. Although further studies are recommended, nursing leaders and policy makers should consider such a solution. © 2016 International Council of Nurses.

  10. Vaginal bleeding in late pregnancy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000627.htm Vaginal bleeding in late pregnancy To use the sharing ... JavaScript. One out of 10 women will have vaginal bleeding during their 3rd trimester. At times, it ...

  11. Positive Almost Periodic Solutions for a Time-Varying Fishing Model with Delay

    Directory of Open Access Journals (Sweden)

    Xia Li

    2011-01-01

    Full Text Available This paper is concerned with a time-varying fishing model with delay. By means of the continuation theorem of coincidence degree theory, we prove that it has at least one positive almost periodic solution.

  12. Fully implicit solution of large-scale non-equilibrium radiation diffusion with high order time integration

    International Nuclear Information System (INIS)

    Brown, Peter N.; Shumaker, Dana E.; Woodward, Carol S.

    2005-01-01

    We present a solution method for fully implicit radiation diffusion problems discretized on meshes having millions of spatial zones. This solution method makes use of high order in time integration techniques, inexact Newton-Krylov nonlinear solvers, and multigrid preconditioners. We explore the advantages and disadvantages of high order time integration methods for the fully implicit formulation on both two- and three-dimensional problems with tabulated opacities and highly nonlinear fusion source terms

  13. A hepatitis C virus infection model with time-varying drug effectiveness: solution and analysis.

    Directory of Open Access Journals (Sweden)

    Jessica M Conway

    2014-08-01

    Full Text Available Simple models of therapy for viral diseases such as hepatitis C virus (HCV or human immunodeficiency virus assume that, once therapy is started, the drug has a constant effectiveness. More realistic models have assumed either that the drug effectiveness depends on the drug concentration or that the effectiveness varies over time. Here a previously introduced varying-effectiveness (VE model is studied mathematically in the context of HCV infection. We show that while the model is linear, it has no closed-form solution due to the time-varying nature of the effectiveness. We then show that the model can be transformed into a Bessel equation and derive an analytic solution in terms of modified Bessel functions, which are defined as infinite series, with time-varying arguments. Fitting the solution to data from HCV infected patients under therapy has yielded values for the parameters in the model. We show that for biologically realistic parameters, the predicted viral decay on therapy is generally biphasic and resembles that predicted by constant-effectiveness (CE models. We introduce a general method for determining the time at which the transition between decay phases occurs based on calculating the point of maximum curvature of the viral decay curve. For the parameter regimes of interest, we also find approximate solutions for the VE model and establish the asymptotic behavior of the system. We show that the rate of second phase decay is determined by the death rate of infected cells multiplied by the maximum effectiveness of therapy, whereas the rate of first phase decline depends on multiple parameters including the rate of increase of drug effectiveness with time.

  14. Periodic solution for state-dependent impulsive shunting inhibitory CNNs with time-varying delays.

    Science.gov (United States)

    Şaylı, Mustafa; Yılmaz, Enes

    2015-08-01

    In this paper, we consider existence and global exponential stability of periodic solution for state-dependent impulsive shunting inhibitory cellular neural networks with time-varying delays. By means of B-equivalence method, we reduce these state-dependent impulsive neural networks system to an equivalent fix time impulsive neural networks system. Further, by using Mawhin's continuation theorem of coincide degree theory and employing a suitable Lyapunov function some new sufficient conditions for existence and global exponential stability of periodic solution are obtained. Previous results are improved and extended. Finally, we give an illustrative example with numerical simulations to demonstrate the effectiveness of our theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Hybrid resonance and long-time asymptotic of the solution to Maxwell's equations

    Energy Technology Data Exchange (ETDEWEB)

    Després, Bruno, E-mail: despres@ann.jussieu.fr [Laboratory Jacques Louis Lions, University Pierre et Marie Curie, Paris VI, Boîte courrier 187, 75252 Paris Cedex 05 (France); Weder, Ricardo, E-mail: weder@unam.mx [Departamento de Física Matemática, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Apartado Postal 20-126, DF 01000 (Mexico)

    2016-03-22

    We study the long-time asymptotic of the solutions to Maxwell's equation in the case of an upper-hybrid resonance in the cold plasma model. We base our analysis in the transfer to the time domain of the recent results of B. Després, L.M. Imbert-Gérard and R. Weder (2014) [15], where the singular solutions to Maxwell's equations in the frequency domain were constructed by means of a limiting absorption principle and a formula for the heating of the plasma in the limit of vanishing collision frequency was obtained. Currently there is considerable interest in these problems, in particular, because upper-hybrid resonances are a possible scenario for the heating of plasmas, and since they can be a model for the diagnostics involving wave scattering in plasmas. - Highlights: • The upper-hybrid resonance in the cold plasma model is considered. • The long-time asymptotic of the solutions to Maxwell's equations is studied. • A method based in a singular limiting absorption principle is proposed.

  16. Timing of Late Holocene surface rupture of the Wairau Fault, Marlborough, New Zealand

    International Nuclear Information System (INIS)

    Zachariasen, J.; Berryman, K.R.; Langridge, R.M.; Prentice, C.; Rymer, M.; Stirling, M.W.; Villamor, P.

    2006-01-01

    Three trenches excavated across the central portion of the right-lateral strike-slip Wairau Fault in South Island, New Zealand, exposed a complex set of fault strands that have displaced a sequence of late Holocene alluvial and colluvial deposits. Abundant charcoal fragments provide age control for various stratigraphic horizons dating back to c. 5610 yr ago. Faulting relations from the Wadsworth trench show that the most recent surface rupture event occurred at least 1290 yr and at most 2740 yr ago. Drowned trees in landslide-dammed Lake Chalice, in combination with charcoal from the base of an unfaulted colluvial wedge at Wadsworth trench, suggest a narrower time bracket for this event of 1811-2301 cal. yr BP. The penultimate faulting event occurred between c. 2370 and 3380 yr, and possibly near 2680 ± 60 cal. yr BP, when data from both the Wadsworth and Dillon trenches are combined. Two older events have been recognised from Dillon trench but remain poorly dated. A probable elapsed time of at least 1811 yr since the last surface rupture, and an average slip rate estimate for the Wairau Fault of 3-5 mm/yr, suggests that at least 5.4 m and up to 11.5 m of elastic shear strain has accumulated since the last rupture. This is near to or greater than the single-event displacement estimates of 5-7 m. The average recurrence interval for surface rupture of the fault determined from the trench data is 1150-1400 yr. Although the uncertainties in the timing of faulting events and variability in inter-event times remain high, the time elapsed since the last event is in the order of 1-2 times the average recurrence interval, implying that the Wairau Fault is near the end of its interseismic period. (author). 44 refs., 10 figs., 1 tab

  17. Cosmological space-times with resolved Big Bang in Yang-Mills matrix models

    Science.gov (United States)

    Steinacker, Harold C.

    2018-02-01

    We present simple solutions of IKKT-type matrix models that can be viewed as quantized homogeneous and isotropic cosmological space-times, with finite density of microstates and a regular Big Bang (BB). The BB arises from a signature change of the effective metric on a fuzzy brane embedded in Lorentzian target space, in the presence of a quantized 4-volume form. The Hubble parameter is singular at the BB, and becomes small at late times. There is no singularity from the target space point of view, and the brane is Euclidean "before" the BB. Both recollapsing and expanding universe solutions are obtained, depending on the mass parameters.

  18. Late Miocene climate and time scale reconciliation: Accurate orbital calibration from a deep-sea perspective

    Science.gov (United States)

    Drury, Anna Joy; Westerhold, Thomas; Frederichs, Thomas; Tian, Jun; Wilkens, Roy; Channell, James E. T.; Evans, Helen; John, Cédric M.; Lyle, Mitch; Röhl, Ursula

    2017-10-01

    Accurate age control of the late Tortonian to early Messinian (8.3-6.0 Ma) is essential to ascertain the origin of benthic foraminiferal δ18O trends and the late Miocene carbon isotope shift (LMCIS), and to examine temporal relationships between the deep-sea, terrasphere and cryosphere. The current Tortonian-Messinian Geological Time Scale (GTS2012) is based on astronomically calibrated Mediterranean sections; however, no comparable non-Mediterranean stratigraphies exist for 8-6 Ma suitable for testing the GTS2012. Here, we present the first high-resolution, astronomically tuned benthic stable isotope stratigraphy (1.5 kyr resolution) and magnetostratigraphy from a single deep-sea location (IODP Site U1337, equatorial Pacific Ocean), which provides unprecedented insight into climate evolution from 8.3-6.0 Ma. The astronomically calibrated magnetostratigraphy provides robust ages, which differ by 2-50 kyr relative to the GTS2012 for polarity Chrons C3An.1n to C4r.1r, and eliminates the exceptionally high South Atlantic spreading rates based on the GTS2012 during Chron C3Bn. We show that the LMCIS was globally synchronous within 2 kyr, and provide astronomically calibrated ages anchored to the GPTS for its onset (7.537 Ma; 50% from base Chron C4n.1n) and termination (6.727 Ma; 11% from base Chron C3An.2n), confirming that the terrestrial C3:C4 shift could not have driven the LMCIS. The benthic records show that the transition into the 41-kyr world, when obliquity strongly influenced climate variability, already occurred at 7.7 Ma and further strengthened at 6.4 Ma. Previously unseen, distinctive, asymmetric saw-tooth patterns in benthic δ18O imply that high-latitude forcing played an important role in late Miocene climate dynamics from 7.7-6.9 Ma. This new integrated deep-sea stratigraphy from Site U1337 can act as a new stable isotope and magnetic polarity reference section for the 8.3-6.0 Ma interval.

  19. IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

    Science.gov (United States)

    Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

    2018-05-01

    Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  20. Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem.

    Science.gov (United States)

    Schilde, M; Doerner, K F; Hartl, R F

    2014-10-01

    In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches.

  1. The existence and regularity of time-periodic solutions to the three-dimensional Navier–Stokes equations in the whole space

    International Nuclear Information System (INIS)

    Kyed, Mads

    2014-01-01

    The existence, uniqueness and regularity of time-periodic solutions to the Navier–Stokes equations in the three-dimensional whole space are investigated. We consider the Navier–Stokes equations with a non-zero drift term corresponding to the physical model of a fluid flow around a body that moves with a non-zero constant velocity. The existence of a strong time-periodic solution is shown for small time-periodic data. It is further shown that this solution is unique in a large class of weak solutions that can be considered physically reasonable. Finally, we establish regularity properties for any strong solution regardless of its size. (paper)

  2. [Immortal time bias in pharmacoepidemiological studies: definition, solutions and examples].

    Science.gov (United States)

    Faillie, Jean-Luc; Suissa, Samy

    2015-01-01

    Among the observational studies of drug effects in chronic diseases, many of them have found effects that were exaggerated or wrong. Among bias responsible for these errors, the immortal time bias, concerning the definition of exposure and exposure periods, is relevantly important as it usually tends to wrongly attribute a significant benefit to the study drug (or exaggerate a real benefit). In this article, we define the mechanism of immortal time bias, we present possible solutions and illustrate its consequences through examples of pharmacoepidemiological studies of drug effects. © 2014 Société Française de Pharmacologie et de Thérapeutique.

  3. An accurate approximate solution of optimal sequential age replacement policy for a finite-time horizon

    International Nuclear Information System (INIS)

    Jiang, R.

    2009-01-01

    It is difficult to find the optimal solution of the sequential age replacement policy for a finite-time horizon. This paper presents an accurate approximation to find an approximate optimal solution of the sequential replacement policy. The proposed approximation is computationally simple and suitable for any failure distribution. Their accuracy is illustrated by two examples. Based on the approximate solution, an approximate estimate for the total cost is derived.

  4. Late radiation effects in animals surviving lethal irradiation

    International Nuclear Information System (INIS)

    Dimitrov, L.A.

    1974-01-01

    Animals (rats, mice, dogs) survived lethal irradiation by means of prophylactic-therapeutic treatments or previously irradiated, were studied for late radiation effects: life span, cachexia and fat growing of hypophysical type, tissue or organ hypoplasia manifested by disturbed hemopoiesis, suppressed function of adrenal gland, etc., suppressed immune reactivity of the irradiated organism, atypical biochemical changes in DNA and protein metabolism, epilation, chronic dermatitis, ulcerations, reduced reproductivity or full sterility, damage of kidneys leading to nephrosclerosis, dishormonal states, cataracts, diffuse sclerotic processes, various kinds of malignant and non-malignant tumors. In these cases hemopoiesis compensated for a definite time peripheral blood composition, but during the late period it showed features of incompleteness: shorter life survival of erythrocytes and thrombocytes manifested by a decreased binding of labelled methionine in these blood elements, anemia and relative thrombocytopenia sometimes with an increased number of polychromatic erythrocytes in peripheral blood and a decreased number of reticulocytes at the same time; lymphopenia and relative leucopenia with an increased number of hypersegmented neutrophils. Decreased reproductivity and atypical biochemical changes available in the first generation of the irradiated animals showed the probable role of mutagenic factors in the emergence of some late radiation effects. A significant part of late radiation sequences were due to neuro-endocrine desintegrations which lead to a disturbed supply of the vessels and afterwards to their sclerosis. Some of the described late radiation effects were also observed in biological controls as festures of ageing while in irradiated animals they were manifested in an earlier period. After application of optimal amounts radioprotectors (AET, cysteamine, serotonin) a more marked protective effect is demonstrated in the early reactions (time survival

  5. Trial function method and exact solutions to the generalized nonlinear Schrödinger equation with time-dependent coefficient

    International Nuclear Information System (INIS)

    Cao Rui; Zhang Jian

    2013-01-01

    In this paper, the trial function method is extended to study the generalized nonlinear Schrödinger equation with time-dependent coefficients. On the basis of a generalized traveling wave transformation and a trial function, we investigate the exact envelope traveling wave solutions of the generalized nonlinear Schrödinger equation with time-dependent coefficients. Taking advantage of solutions to trial function, we successfully obtain exact solutions for the generalized nonlinear Schrödinger equation with time-dependent coefficients under constraint conditions. (general)

  6. Manufactured solutions for the three-dimensional Euler equations with relevance to Inertial Confinement Fusion

    International Nuclear Information System (INIS)

    Waltz, J.; Canfield, T.R.; Morgan, N.R.; Risinger, L.D.; Wohlbier, J.G.

    2014-01-01

    We present a set of manufactured solutions for the three-dimensional (3D) Euler equations. The purpose of these solutions is to allow for code verification against true 3D flows with physical relevance, as opposed to 3D simulations of lower-dimensional problems or manufactured solutions that lack physical relevance. Of particular interest are solutions with relevance to Inertial Confinement Fusion (ICF) capsules. While ICF capsules are designed for spherical symmetry, they are hypothesized to become highly 3D at late time due to phenomena such as Rayleigh–Taylor instability, drive asymmetry, and vortex decay. ICF capsules also involve highly nonlinear coupling between the fluid dynamics and other physics, such as radiation transport and thermonuclear fusion. The manufactured solutions we present are specifically designed to test the terms and couplings in the Euler equations that are relevant to these phenomena. Example numerical results generated with a 3D Finite Element hydrodynamics code are presented, including mesh convergence studies

  7. Reproductive rights: Current issues of late abortion

    Directory of Open Access Journals (Sweden)

    Mujović-Zornić Hajrija

    2009-01-01

    Full Text Available This article considers the legal issues surrounding induced late abortion in cases when severe medical, therapeutic or ethical reasons have not been in dispute. Generally discussing the essential question about abortion today, it means not anymore legality of abortion but, in the first place, safety of abortion. From the aspect of woman health the most important aim is to detect and avoid possible risks of medical intervention, such as late abortion present. This is the matter of medical law context and also the matter of the woman's reproductive rights, here observed through legislation and court practice. The gynecologist has an obligation to obtain the informed consent of each patient. Information's should be presented in reasonably understandable terms and include alternative modes of treatment, objectives, risks, benefits, possible complications, and anticipated results of such treatment. Pregnant woman should receive supportive counseling before and particularly after the procedure. The method chosen for all terminations should ensure that the fetus is born dead. This should be undertaken by an appropriately trained practitioner. Reform in abortion law, making it legally accessible to woman, is not necessarily the product of a belief in woman's rights, but can be a means of bringing the practice of abortion back under better control. Counseling and good medical practice in performing late abortion are the instruments to drive this point even further home. It does not undermine the woman who wants to make a positive decision about her life and its purpose is not to produce feelings of insecurity and guilt. It concludes that existing law should not be changed but that clear rules should be devised and board created to review late term abortion. In Serbia, this leads to creation and set up guidelines for reconciling medical justification for late abortion with existing law, especially with solutions which brings comparative law. .

  8. Late-time Near-infrared Observations of SN 2005df

    Science.gov (United States)

    Diamond, Tiara R.; Hoeflich, Peter; Gerardy, Christopher L.

    2015-06-01

    We present late-time near-infrared (NIR) spectral evolution, at 200-400 days, for the Type Ia supernova SN 2005df. The spectra show numerous strong emission features of [Co ii], [Co iii], and [Fe ii] throughout the 0.8-1.8 μm region. As the spectrum ages, the cobalt features fade as would be expected from the decay of 56Co to 56Fe. We show that the strong and isolated [Fe ii] emission line at 1.644 μ {m} provides a unique tool to analyze NIR spectra of SNe Ia. Normalization of spectra to this line allows the separation of features produced by stable versus unstable isotopes of iron group elements. We develop a new method of determining the initial central density, {ρ }c, and the magnetic field, B, of the white dwarf (WD) using the width of the 1.644 μ {m} line. The line width (LW) is sensitive because of electron capture in the early stages of burning, which increases as a function of density. The sensitivity of the LW to B increases with time, and the effects of the magnetic field shift toward later times with decreasing {ρ }c. Through comparison with spherical models, the initial central density for SN 2005df is measured as {ρ }c=0.9(+/- 0.2)× {10}9 {g} {{cm}}-3, which corresponds to a WD close to the Chandrasekhar mass, with {M}{WD}=1.31(+/- 0.03) {M}⊙ and systematic error less than 0.04 {M}⊙. This error estimate is based on spherical models. We discuss the potential uncertainties due to multi-dimensional effects, mixing, and rotation. The latter two effects would increase the estimate of the WD mass. Within {M}{Ch} explosions, however, the central density found for SN 2005df is very low for a H-accretor, possibly suggesting a helium star companion or a tidally disrupted WD companion. As an alternative, we suggest mixing of the central region. We find some support for high initial magnetic fields of strength {10}6 {G} for SN 2005df, however, 0 {G} cannot be ruled out because of noise in the spectra combined with low {ρ }c. We discuss our findings in

  9. Cohort Profile: The Danish Testicular Cancer Late Treatment Effects Cohort (DaTeCa-LATE

    Directory of Open Access Journals (Sweden)

    Michael Kreiberg

    2018-02-01

    Full Text Available The cohort was set up in order to analyze late effects in long-term testicular cancer survivors (TCS and to contribute to the design of future follow-up programs addressing and potentially preventing late effects. Data for this cross-sectional study were collected between January 1, 2014, and December 31, 2016, among living Danish TCS and 60% agreed to participate in the cohort (N = 2,572. Mean time since testicular cancer (TC diagnosis was 18 years (range 7–33 and mean age of participants was 53 years (range 25–95. Data consist of results of a questionnaire with patient reported outcomes which covers a broad range of items on late-effects. The study also included data obtained through linkages to Danish registries, a biobank, and clinical data from hospital files and pathology reports originating from the Danish Testicular Cancer Database (DaTeCa. The treatment during the observation period has been nearly the same for all stages of TC and is in agreement with today’s standard treatment, this allows for interesting analysis with a wide timespan. We have extensive data on non-responders and are able to validate our study findings. Data from a Danish reference population (N = 162,283 allow us to compare our findings with a Danish background population. The cohort can easily be extended to access more outcomes, or include new TCS. A limitation of the present study is the cross-sectional design and despite the large sample size, The Danish Testicular Cancer Late Treatment Effects Cohort (DaTeCa-LATE lacks statistical power to study very rare late effects. Since it was voluntary to participate in the study we have some selection bias, for instance, we lack responders who were not in a paired relationship, but we would still argue that this cohort of TCSs is representative for TCSs in Denmark.Collaboration and data accessResearches interested in collaboration with the DaTeCa-LATE study group please contact Professor Gedske Daugaard

  10. Promoting Savings at Tax Time through a Video-Based Solution-Focused Brief Coaching Intervention

    Directory of Open Access Journals (Sweden)

    Lance Palmer

    2016-09-01

    Full Text Available Solution-focused brief coaching, based on solution-focused brief therapy, is a well-established practice model and is used widely to help individuals progress toward desired outcomes in a variety of settings. This papers presents the findings of a pilot study that examined the impact of a video-based solution-focused brief coaching intervention delivered in conjunction with income tax preparation services at a Volunteer Income Tax Assistance location (n = 212. Individuals receiving tax preparation assistance were randomly assigned to one of four treatment groups: 1 control group; 2 video-based solution-focused brief coaching; 3 discount card incentive; 4 both the video-based solution-focused brief coaching and the discount card incentive. Results of the study indicate that the video-based solution-focused brief coaching intervention increased both the frequency and amount of self-reported savings at tax time. Results also indicate that financial therapy based interventions may be scalable through the use of technology.

  11. Analytical Solutions for Multi-Time Scale Fractional Stochastic Differential Equations Driven by Fractional Brownian Motion and Their Applications

    Directory of Open Access Journals (Sweden)

    Xiao-Li Ding

    2018-01-01

    Full Text Available In this paper, we investigate analytical solutions of multi-time scale fractional stochastic differential equations driven by fractional Brownian motions. We firstly decompose homogeneous multi-time scale fractional stochastic differential equations driven by fractional Brownian motions into independent differential subequations, and give their analytical solutions. Then, we use the variation of constant parameters to obtain the solutions of nonhomogeneous multi-time scale fractional stochastic differential equations driven by fractional Brownian motions. Finally, we give three examples to demonstrate the applicability of our obtained results.

  12. Late radiation effects in animals surviving lethal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrov, L A

    1974-01-01

    Animals (rats, mice, dogs) survived lethal irradiation by means of prophylactic-therapeutic treatments or previously irradiated, were studied for late radiation effects: life span, cachexia and fat growing of hypophysical type, tissue or organ hypoplasia manifested by disturbed hemopoiesis, suppressed function of adrenal gland, etc., suppressed immune reactivity of the irradiated organism, atypical biochemical changes in DNA and protein metabolism, epilation, chronic dermatitis, ulcerations, reduced reproductivity or full sterility, damage of kidneys leading to nephrosclerosis, dishormonal states, cataracts, diffuse sclerotic processes, various kinds of malignant and non-malignant tumors. In these cases hemopoiesis compensated for a definite time peripheral blood composition, but during the late period it showed features of incompleteness: shorter life survival of erythrocytes and thrombocytes manifested by a decreased binding of labelled methionine in these blood elements, anemia and relative thrombocytopenia sometimes with an increased number of polychromatic erythrocytes in peripheral blood and a decreased number of reticulocytes at the same time; lymphopenia and relative leucopenia with an increased number of hypersegmented neutrophils. Decreased reproductivity and atypical biochemical changes available in the first generation of the irradiated animals showed the probable role of mutagenic factors in the emergency of some late radiation effects. A significant part of late radiation sequences were due to neuro-endocrine disintegrations. Some of the described late radiation effects were also observed in biological controls as features of ageing. After application of radioprotectors (AET, cysteamine, serotonin) a more marked protective effect is demonstrated in the early reactions (time survival till 30th day, DNA and protein metabolism, immune reactions) of the lethally irradiated animals.

  13. Exact solutions for the quintic nonlinear Schroedinger equation with time and space modulated nonlinearities and potentials

    International Nuclear Information System (INIS)

    Belmonte-Beitia, Juan; Calvo, Gabriel F.

    2009-01-01

    In this Letter, by means of similarity transformations, we construct explicit solutions to the quintic nonlinear Schroedinger equation with potentials and nonlinearities depending both on time and on the spatial coordinates. We present the general approach and use it to study some examples and find nontrivial explicit solutions such as periodic (breathers), quasiperiodic and bright and dark soliton solutions

  14. Extending the D’alembert solution to space–time Modified Riemann–Liouville fractional wave equations

    International Nuclear Information System (INIS)

    Godinho, Cresus F.L.; Weberszpil, J.; Helayël-Neto, J.A.

    2012-01-01

    In the realm of complexity, it is argued that adequate modeling of TeV-physics demands an approach based on fractal operators and fractional calculus (FC). Non-local theories and memory effects are connected to complexity and the FC. The non-differentiable nature of the microscopic dynamics may be connected with time scales. Based on the Modified Riemann–Liouville definition of fractional derivatives, we have worked out explicit solutions to a fractional wave equation with suitable initial conditions to carefully understand the time evolution of classical fields with a fractional dynamics. First, by considering space–time partial fractional derivatives of the same order in time and space, a generalized fractional D’alembertian is introduced and by means of a transformation of variables to light-cone coordinates, an explicit analytical solution is obtained. To address the situation of different orders in the time and space derivatives, we adopt different approaches, as it will become clear throughout this paper. Aspects connected to Lorentz symmetry are analyzed in both approaches.

  15. Extraction of Collagen from Chicken Feet with Various Acidic Solutions and Soaking Time

    Directory of Open Access Journals (Sweden)

    Prayitno Prayitno

    2007-05-01

    Full Text Available The objective of this research was to know the ability of various acidic solutions on dissolving collagen  chicken feet, with different soaked time.  Each acid 5 percent (v/v, collagen extraction was done by washing chicken feet and then cutted into small pieces and finally grinded.  Every 100 gram treatment was soaked in acetic acid (a1, citric acid (a2, lactic acid (a3 and hydrochloric acid (a4, for 12, 24 and 36 hours.  Precipitated collagen in the filtrate was 5 percent NaOH to reach the neutral pH (pH 7.  Collagen precipitate was separated by filtration usingfilter paper and then  rendement was calculated, HPLC was used to determin amino acid composition, and SDS-PAGE was use determin the type of collagen.  This experiment use factorial completely randomized design (CRD 4 x 3 and three time replication.   Result showed that lactic acid has highest capability to dissolve collagen, while citric acid the lowest.  Combination of acid solution and soaking time had significant (P<0.01 effect on dissolving collagen of chicken feet.  Extracted collagen in all acid solution, hassame amino acid, composition but different in percentage of amino acid molecules.  Collagen type in treatment combination was the same, but for soaking time of 36 hours revealed some peptide band.  Lactic acid had highest capability of collagen extraction in chicken feet than citric acid, acetic acid and hydrochloric acid with soaking time of 12, 24 and 36 hours.  It was estimated that extracted collagen can be grouped to type I consisted of two chain of a1. (Animal Production 9(2: 99-104 (2007   Key Words : Chicken feet, acids, soaking time, collagen

  16. Factor analysis of symptom profile in early onset and late onset OCD.

    Science.gov (United States)

    Grover, Sandeep; Sarkar, Siddharth; Gupta, Gourav; Kate, Natasha; Ghosh, Abhishek; Chakrabarti, Subho; Avasthi, Ajit

    2018-04-01

    This study aimed to assess the factor structure of early and late onset OCD. Additionally, cluster analysis was conducted in the same sample to assess the applicability of the factors. 345 participants were assessed with Yale Brown Obsessive Compulsive Scale symptom checklist. Patients were classified as early onset (onset of symptoms at age ≤ 18 years) and late onset (onset at age > 18 years) OCD depending upon the age of onset of the symptoms. Factor analysis and cluster analysis of early-onset and late-onset OCD was conducted. The study sample comprised of 91 early onset and 245 late onset OCD subjects. Males were more common in the early onset group. Differences in the frequency of phenomenology related to contamination related, checking, repeating, counting and ordering/arranging compulsions were present across the early and late onset groups. Factor analysis of YBOCS revealed a 3 factor solution for both the groups, which largely concurred with each other. These factors were named as hoarding and symmetry (factor-1), contamination (factor-2) and aggressive, sexual and religious factor (factor-3). To conclude this study shows that factor structure of symptoms of OCD seems to be similar between early-onset and late-onset OCD. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Time-domain analytic Solutions of two-wire transmission line excited by a plane-wave field

    Institute of Scientific and Technical Information of China (English)

    Ni Gu-Yan; Yan Li; Yuan Nai-Chang

    2008-01-01

    This paper reports that an analytic method is used to calculate the load responses of the two-wire transmission line excited by a plane-wave directly in the time domain.By the frequency-domain Baum-Liu-Tesche(BLT)equation,the time-domain analytic solutions are obtained and expressed in an infinite geometric series.Moreover,it is shown that there exist only finite nonzero terms in the infinite geometric series if the time variate is at a finite interval.In other word.the time-domain analytic solutions are expanded in a finite geometric series indeed if the time variate is at a finite interval.The computed results are subsequently compared with transient responses obtained by using the frequency-domain BLT equation via a fast Fourier transform,and the agreement is excellent.

  18. The effect of IFSA 2013 on late payment of takāful benefits

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Jinnah Ahmad

    2017-07-01

    Full Text Available Purpose - This paper aims to examine the implications of compensation on late payment of takāful benefit imposed in the Islamic Financial Services Act 2013 on the takāful industry in Malaysia. It also aims to identify the issues and challenges faced by takāful operators in the implementation of the compensation and propose solutions for the benefits of the takāful industry. Design/methodology/approach - This research uses the qualitative approach to understand the practices of claims in takāful and to analyze the implication of compensation on late payment of takāful benefit to the takāful industry in Malaysia. Data are collected through survey and interview with various takāful stakeholders. Findings - Some of the key findings in this research are that the compensation of late payment of takāful benefit has a positive impact to the takāful industry. The research also found some Sharīʿah operational issues in terms of its implementation among takāful operators. Research limitations/implications - The research focuses on compensation on late payment of takāful benefit claim in death and personal accident only. Practical implications - The research offers certainty to the takāful industry and an explanation to academic and legal fraternities on the implementation of compensation on late payment of takāful benefit according to Islamic Financial Services Act (IFSA 2013. Originality/value - The research provides a valuable contribution to the current practices of takāful operators, identifies some issues and challenges of its implementation and proposes the solution.

  19. Global low-energy weak solution and large-time behavior for the compressible flow of liquid crystals

    Science.gov (United States)

    Wu, Guochun; Tan, Zhong

    2018-06-01

    In this paper, we consider the weak solution of the simplified Ericksen-Leslie system modeling compressible nematic liquid crystal flows in R3. When the initial data are of small energy and initial density is positive and essentially bounded, we prove the existence of a global weak solution in R3. The large-time behavior of a global weak solution is also established.

  20. Late complications after radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. [University Hospital Hamburg-Eppendorf (Germany). Inst. of Biophysics and Radiobiology; University Hospital Hamburg-Eppendorf (Germany). Lab. of Radiobiology and Experimental Radiooncology; Beck-Bornholdt, H.P. [University Hospital Hamburg-Eppendorf (Germany). Inst. of Biophysics and Radiobiology; Svoboda, V. [University Hospital Hamburg-Eppendorf (Germany). Inst. of Biophysics and Radiobiology; Portsmouth Oncology Centre, Saint Mary' s Hospital (United Kingdom). Dept. of Radiotherapy; Alberti, W. [University Hospital Hamburg-Eppendorf (Germany). Dept. of Radiotherapy and Radiooncology; Herrmann, T. [Technical Univ. Dresden (Germany). Dept. of Radiotherapy and Radiooncology

    2012-11-15

    Background: The aim of the present study was to analyze in detail the time course of the incidence of radiation-induced late effects. For this purpose, unpublished data of patients treated by radiation therapy in Hamburg in the late 1980s were analyzed. Relatively large volumes were exposed to comparatively high doses, thus leading to a high rate of treatment-related side effects. Patients and methods: A total of 180 consecutive patients received radiotherapy for prostate cancer. The median age was 66 years (range 41-88 years). The median of the maximum dose was 77.5 Gy (range 56.3-95 Gy) and overall treatment time was 51 days (range 28-128 days). Endpoints analyzed were late complications of grade 3 or higher, overall and disease-free survival, local tumor control, and distant metastases. Data analysis was actuarial and the log-rank test was used to compare the various subgroups. Results After 2 years, 80.5 {+-} 3.2% of the patients were without any complications of grade 3 or higher, and after 5 years a constant level of 70.3 {+-} 4.0% was approached. When multiple lesions occurred per patient, the later events were disregarded. A total of 66 complications occurred in 42 patients. The percentage of patients being free from late complications, plotted as a function of time after start of radiation therapy, was adequately described by an exponential function and a constant fraction. Complications approached a constant level of 70.3% at a rate of 5.3% per month. This means that patients who will develop a complication do so at exponential kinetics and at a relatively high rate, whereas about 70% of the patients will never experience a late effect even over long observation periods. After subdividing the maximum dose into three equal dose groups of 55 patients each (< 73.3 Gy, 73.3-80 Gy, > 80 Gy), the constant fraction decreased from 85.7 to 72.8% and 52.2%, whereas the incidence rate was 4.3%, 7.7%, and 5.6% per month and, thus, almost independent of radiation dose

  1. Time Resolved X-Ray Scattering of molecules in Solution

    DEFF Research Database (Denmark)

    Brandt van Driel, Tim

    The dissertation describes the use of Time-Resolved X-ray Diffuse Scattering (TR-XDS) to study photo-induced structural changes in molecules in solution. The application of the technique is exemplified with experiments on two bimetallic molecules. The main focus is on the data-flow and process......)42+ obtained at European Synchrotron Radiation Facility (ESRF) are presented to exemplify TR-XDS at synchrotrons. Similarly, measurements on Ir2(dimen)42+ are used to show the XFEL data-flow and how it deviates from the prior. A method to identify and account for systematic fluctuations...

  2. Working with Students Who Are Late-Deafened. PEPNet Tipsheet

    Science.gov (United States)

    Clark, Mary

    2010-01-01

    Late-deafness means deafness that happened postlingually, any time after the development of speech and language in a person who has identified with hearing society through schooling, social connections, etc. Students who are late-deafened cannot understand speech without visual aids such as speechreading, sign language, and captioning (although…

  3. Zhang neural network for online solution of time-varying convex quadratic program subject to time-varying linear-equality constraints

    International Nuclear Information System (INIS)

    Zhang Yunong; Li Zhan

    2009-01-01

    In this Letter, by following Zhang et al.'s method, a recurrent neural network (termed as Zhang neural network, ZNN) is developed and analyzed for solving online the time-varying convex quadratic-programming problem subject to time-varying linear-equality constraints. Different from conventional gradient-based neural networks (GNN), such a ZNN model makes full use of the time-derivative information of time-varying coefficient. The resultant ZNN model is theoretically proved to have global exponential convergence to the time-varying theoretical optimal solution of the investigated time-varying convex quadratic program. Computer-simulation results further substantiate the effectiveness, efficiency and novelty of such ZNN model and method.

  4. Approximate solutions for radial travel time and capture zone in unconfined aquifers.

    Science.gov (United States)

    Zhou, Yangxiao; Haitjema, Henk

    2012-01-01

    Radial time-of-travel (TOT) capture zones have been evaluated for unconfined aquifers with and without recharge. The solutions of travel time for unconfined aquifers are rather complex and have been replaced with much simpler approximate solutions without significant loss of accuracy in most practical cases. The current "volumetric method" for calculating the radius of a TOT capture zone assumes no recharge and a constant aquifer thickness. It was found that for unconfined aquifers without recharge, the volumetric method leads to a smaller and less protective wellhead protection zone when ignoring drawdowns. However, if the saturated thickness near the well is used in the volumetric method a larger more protective TOT capture zone is obtained. The same is true when the volumetric method is used in the presence of recharge. However, for that case it leads to unreasonableness over the prediction of a TOT capture zone of 5 years or more. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  5. Time-domain analytic solutions of two-wire transmission line excited by a plane-wave field

    International Nuclear Information System (INIS)

    Ni Guyan; Yan Li; Yuan Naichang

    2008-01-01

    This paper reports that an analytic method is used to calculate the load responses of the two-wire transmission line excited by a plane-wave directly in the time domain. By the frequency-domain Baum–Liu–Tesche (BLT) equation, the time-domain analytic solutions are obtained and expressed in an infinite geometric series. Moreover, it is shown that there exist only finite nonzero terms in the infinite geometric series if the time variate is at a finite interval. In other word, the time-domain analytic solutions are expanded in a finite geometric series indeed if the time variate is at a finite interval. The computed results are subsequently compared with transient responses obtained by using the frequency-domain BLT equation via a fast Fourier transform, and the agreement is excellent. (the physics of elementary particles and fields)

  6. Political and economic factors of late transition in Serbia

    Directory of Open Access Journals (Sweden)

    Josifidis Kosta L.

    2004-01-01

    Full Text Available The transition in Serbia is late, from the aspects of both its start and course. The initial conditionality, strategy, sequentially, prospects and results shape transition profile. Key factors of the late transition are grouped within a complex of political and economic factors, which are themselves ambivalent - their external and internal effects are evident. An institutional vacuum is especially limiting complex, with a significant influence on the political and economic aspects of the transition. An analysis of the two groups of intertwined factors serves as a basis for making a projection of future course and reform dynamics in Serbia. Different scenarios are present. An increase or decrease in the transition dynamics is conditioned by elimination of negative impacts of political and economic factors, i.e. by promotion of positive aspects of the solutions.

  7. Localization in nonuniform media: Exponential decay of the late-time Ginzburg-Landau impulse response

    International Nuclear Information System (INIS)

    Smith, E.

    1998-01-01

    Instanton methods have been used, in the context of a classical Ginzburg-Landau field theory, to compute the averaged density of states and probability Green close-quote s function for electrons scattered by statistically uniform site energy perturbations. At tree level, all states below some critical energy appear localized, and all states above extended. The same methods are applied here to macroscopically nonuniform systems, for which it is shown that localized and extended states can be coupled through a tunneling barrier created by the instanton background. Both electronic and acoustic systems are considered. An incoherent exponential decay is predicted for the late-time impulse response in both cases, valid for long-wavelength nonuniformity, and scaling relations are derived for the decay time constant as a function of energy or frequency and spatial dimension. The acoustic results are found to lie within a range of scaling relations obtained empirically from measurements of seismic coda, suggesting a connection between the universal properties of localization and the robustness of the observed scaling. The relation of instantons to the acoustic coherent-potential approximation is demonstrated in the recovery of the uniform limit. copyright 1998 The American Physical Society

  8. Exploring Late Globalization

    DEFF Research Database (Denmark)

    Turcan, Romeo V.

    2016-01-01

    literature on late globalization from sociocultural and economic perspectives. It illustrates in a vignette the character and features of late globalization observable in the withdrawal from foreign locations or deinternationalization of universities, as late globalizing entitis. The paper discusses...

  9. A theoretical framework for modeling dilution enhancement of non-reactive solutes in heterogeneous porous media.

    Science.gov (United States)

    de Barros, F P J; Fiori, A; Boso, F; Bellin, A

    2015-01-01

    Spatial heterogeneity of the hydraulic properties of geological porous formations leads to erratically shaped solute clouds, thus increasing the edge area of the solute body and augmenting the dilution rate. In this study, we provide a theoretical framework to quantify dilution of a non-reactive solute within a steady state flow as affected by the spatial variability of the hydraulic conductivity. Embracing the Lagrangian concentration framework, we obtain explicit semi-analytical expressions for the dilution index as a function of the structural parameters of the random hydraulic conductivity field, under the assumptions of uniform-in-the-average flow, small injection source and weak-to-mild heterogeneity. Results show how the dilution enhancement of the solute cloud is strongly dependent on both the statistical anisotropy ratio and the heterogeneity level of the porous medium. The explicit semi-analytical solution also captures the temporal evolution of the dilution rate; for the early- and late-time limits, the proposed solution recovers previous results from the literature, while at intermediate times it reflects the increasing interplay between large-scale advection and local-scale dispersion. The performance of the theoretical framework is verified with high resolution numerical results and successfully tested against the Cape Cod field data. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. [Cause of late death in liver transplant recipients].

    Science.gov (United States)

    Coelho, Júlio Cézar Uili; Parolin, Mônica B; Matias, Jorge Eduardo Fouto; Jorge, Fernando Marcus Felipe; Canan Júnior, Lady Wilson

    2003-01-01

    The objective is to present the causes of late death in patients subjected to liver transplantation. A total of 209 patients were subjected to 223 liver transplantations (14 retransplantations). The computerized study protocol sheets were evaluated to determine the causes of late death (> 6 months after transplantation). Of the 209 patients, 30 had late death. Ductopenic rejection (chronic rejection) was the most common cause and it was observed in 10 patients. Time after transplantation at the moment of death of this group of patients varied from 11 to 57 months, with an average of 29 months. Seven patients died at the hospital admission of hepatic retransplantation. Other causes of late death were sepsis, lymphoproliferative disease, chronic renal insufficiency, and hepatic insufficiency. The most common cause of late death after liver transplantation is ductopenic rejection, followed by complications of retransplantation and sepsis. Death owing to ductopenic rejection may occur even many years after transplantation.

  11. Existence of solutions to nonlinear parabolic unilateral problems with an obstacle depending on time

    Directory of Open Access Journals (Sweden)

    Nabila Bellal

    2014-10-01

    Full Text Available Using the penalty method, we prove the existence of solutions to nonlinear parabolic unilateral problems with an obstacle depending on time. To find a solution, the original inequality is transformed into an equality by adding a positive function on the right-hand side and a complementary condition. This result can be seen as a generalization of the results by Mokrane in [11] where the obstacle is zero.

  12. WILDFIRES IN THE LATE PALAEOZOIC AND MESOZOIC OF THE SOUTHERN ALPS THE LATE PERMIAN OF THE BLETTERBACH-BUTTERLOCH AREA (NORTHERN ITALY

    Directory of Open Access Journals (Sweden)

    DIETER UHL

    2012-07-01

    Full Text Available For the first time fossil macroscopic remains of charcoal as direct evidence of palaeo-wildfires from the Late Permian Gröden Formation of the Bletterbach-Butterloch area in Northern Italy is described. The charcoal consists of pycnoxylic wood and originates from gymnosperms, but a more specific affiliation is not possible due to the fragmentary nature of the material. On a global scale our knowledge about Late Permian fire-ecology is still rather scarce and this finding helps to fill one of the numerous geographical gaps in our current knowledge about Late Permian wildfires. 

  13. An Analytical Solution for Probabilistic Guarantees of Reservation Based Soft Real--Time Systems

    OpenAIRE

    Palopoli, Luigi; Fontanelli, Daniele; Abeni, Luca; Villalba Frias, Bernardo

    2015-01-01

    We show a methodology for the computation of the probability of deadline miss for a periodic real-time task scheduled by a resource reservation algorithm. We propose a modelling technique for the system that reduces the computation of such a probability to that of the steady state probability of an infinite state Discrete Time Markov Chain with a periodic structure. This structure is exploited to develop an efficient numeric solution where different accuracy/computation time trade-offs can be...

  14. Early and Late Retirement Exits

    Science.gov (United States)

    Brougham, Ruby R.; Walsh, David A.

    2009-01-01

    The current study proposes that personal need fulfillment (relatedness, generativity, identity, growth, and finances) predicts early and late retirement intentions. The personal needs of 160 full-time older employees were measured by personal goals, job satisfactions, job characteristics, and intrinsic motivation. Results suggest that the personal…

  15. Similarity solutions of time-dependent relativistic radiation-hydrodynamical plane-parallel flows

    Science.gov (United States)

    Fukue, Jun

    2018-04-01

    Similarity solutions are examined for the frequency-integrated relativistic radiation-hydrodynamical flows, which are described by the comoving quantities. The flows are vertical plane-parallel time-dependent ones with a gray opacity coefficient. For adequate boundary conditions, the flows are accelerated in a somewhat homologous manner, but terminate at some singular locus, which originates from the pathological behavior in relativistic radiation moment equations truncated in finite orders.

  16. Late-onset CMV disease following CMV prophylaxis.

    LENUS (Irish Health Repository)

    Donnelly, C

    2012-02-01

    BACKGROUND: Cytomegalovirus (CMV) is the most common opportunistic infection after solid-organ transplantation, increasing morbidity and mortality. Three months of oral valganciclovir have been shown to provide effective prophylaxis. Late-onset CMV disease, occurring after the discontinuation of prophylaxis, is now increasingly recognised. AIMS: To investigate the incidence and the time of detection of CMV infections in liver transplant recipients who received CMV prophylaxis. METHODS: Retrospective review of 64 high- and moderate-risk patients with 1 year of follow-up. RESULTS: The incidence of CMV infection was 12.5%, with 4.7% disease. All cases of symptomatic CMV disease were of late-onset. CONCLUSIONS: The incidence of CMV infections in this study was low compared with literature reports; however, the late-onset disease is an emerging problem. Detection of late-onset disease may be delayed because of less frequent clinic follow-up visits. Increased regular laboratory monitoring may allow earlier detection at the asymptomatic infection stage.

  17. Density-Dependent Conformable Space-time Fractional Diffusion-Reaction Equation and Its Exact Solutions

    Science.gov (United States)

    Hosseini, Kamyar; Mayeli, Peyman; Bekir, Ahmet; Guner, Ozkan

    2018-01-01

    In this article, a special type of fractional differential equations (FDEs) named the density-dependent conformable fractional diffusion-reaction (DDCFDR) equation is studied. Aforementioned equation has a significant role in the modelling of some phenomena arising in the applied science. The well-organized methods, including the \\exp (-φ (\\varepsilon )) -expansion and modified Kudryashov methods are exerted to generate the exact solutions of this equation such that some of the solutions are new and have been reported for the first time. Results illustrate that both methods have a great performance in handling the DDCFDR equation.

  18. Late Pleistocene dune activity in the central Great Plains, USA

    Science.gov (United States)

    Mason, J.A.; Swinehart, J.B.; Hanson, P.R.; Loope, D.B.; Goble, R.J.; Miao, X.; Schmeisser, R.L.

    2011-01-01

    Stabilized dunes of the central Great Plains, especially the megabarchans and large barchanoid ridges of the Nebraska Sand Hills, provide dramatic evidence of late Quaternary environmental change. Episodic Holocene dune activity in this region is now well-documented, but Late Pleistocene dune mobility has remained poorly documented, despite early interpretations of the Sand Hills dunes as Pleistocene relicts. New optically stimulated luminescence (OSL) ages from drill cores and outcrops provide evidence of Late Pleistocene dune activity at sites distributed across the central Great Plains. In addition, Late Pleistocene eolian sands deposited at 20-25 ka are interbedded with loess south of the Sand Hills. Several of the large dunes sampled in the Sand Hills clearly contain a substantial core of Late Pleistocene sand; thus, they had developed by the Late Pleistocene and were fully mobile at that time, although substantial sand deposition and extensive longitudinal dune construction occurred during the Holocene. Many of the Late Pleistocene OSL ages fall between 17 and 14 ka, but it is likely that these ages represent only the later part of a longer period of dune construction and migration. At several sites, significant Late Pleistocene or Holocene large-dune migration also probably occurred after the time represented by the Pleistocene OSL ages. Sedimentary structures in Late Pleistocene eolian sand and the forms of large dunes potentially constructed in the Late Pleistocene both indicate sand transport dominated by northerly to westerly winds, consistent with Late Pleistocene loess transport directions. Numerical modeling of the climate of the Last Glacial Maximum has often yielded mean monthly surface winds southwest of the Laurentide Ice Sheet that are consistent with this geologic evidence, despite strengthened anticyclonic circulation over the ice sheet. Mobility of large dunes during the Late Pleistocene on the central Great Plains may have been the result of

  19. EFFECT OF CURRENT, TIME, FEED AND CATHODE TYPE ON ELECTROPLATING PROCESS OF URANIUM SOLUTION

    Directory of Open Access Journals (Sweden)

    Sigit Sigit

    2017-02-01

    Full Text Available ABSTRACT   EFFECT OF CURRENT, TIME, FEED AND CATHODE TYPE ON ELECTROPLATING PROCESS OF URANIUM SOLUTION. Electroplating process of uranyl nitrate and effluent process has been carried out in order to collect uranium contained therein using electrode Pt / Pt and Pt / SS at various currents and times. Material used for electrode were Pt (platinum and SS (Stainlees Steel. Feed solution of 250 mL was entered into a beaker glass equipped with Pt anode - Pt cathode or Pt anode - SS cathode, then fogged direct current from DC power supply with specific current and time so that precipitation of uranium sticking to the cathode. After the processes completed, the cathode was removed and weighed to determine weight of precipitates, while the solution was analyzed to determine the uranium concentration decreasing after and before electroplating process. The experiments showed that a relatively good time to acquire uranium deposits at the cathode was 1 hour by current 7 ampere, uranyl nitrate as feed, and Pt (platinum as cathode. In these conditions, uranium deposits attached to the cathode amounted to 74.96% of the original weight of uranium oxide in the feed or 206.5 mg weight. The use of Pt cathode for  uranyl nitrate, SS and Pt cathode for effluent process feed gave uranium specific weight at the cathode of 12.99 mg/cm2, 2.4 mg/cm2 and 5.37 mg/cm2 respectively for current 7 ampere and electroplating time 1 hour. Keywords: Electroplating, uranyl nitrate, effluent process, Pt/Pt electrode, Pt/SS electrode

  20. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  1. Solution of the Burgers Equation in the Time Domain

    Directory of Open Access Journals (Sweden)

    M. Bednařík

    2002-01-01

    Full Text Available This paper deals with a theoretical description of the propagation of a finite amplitude acoustic waves. The theory based on the homogeneous Burgers equation of the second order of accuracy is presented here. This equation takes into account both nonlinear effects and dissipation. The method for solving this equation, using the well-known Cole-Hopf transformation, is presented. Two methods for numerical solution of these equations in the time domain are presented. The first is based on the simple Simpson method, which is suitable for smaller Goldberg numbers. The second uses the more advanced saddle point method, and is appropriate for large Goldberg numbers.

  2. Late baryogenesis faces primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Delbourgo-Salvador, P.; Audouze, J.; Salati, P.

    1991-11-01

    Since the sphalleron mechanism present in the standard theory of electro-weak interactions violates B+L, models have been suggested where baryogenesis takes place at late epochs and is concomitant with primordial nucleosynthesis. The possibility for the baryon asymmetry to be generated was numerically investigated at the same time as the light elements are cooked. The primordial yields of D, 3 He, 4 He and 7 Li were shown to exceed the upper limits inferred from observation, unless baryogenesis is anterior to the freeze-out of the weak interactions. This implies strong constraints on scenarios where the baryon asymmetry originates from the late decay of massive gravitinos. (author) 18 refs., 6 figs

  3. Time course for memory dysfunction in early-life and late-life major depression: a longitudinal study from the Juntendo University Mood Disorder Project.

    Science.gov (United States)

    Maeshima, Hitoshi; Baba, Hajime; Nakano, Yoshiyuki; Satomura, Emi; Namekawa, Yuki; Takebayashi, Naoko; Nomoto, Hiroshi; Suzuki, Toshihito; Mimura, Masaru; Arai, Heii

    2013-10-01

    Previous studies have demonstrated that patients with depression also have memory dysfunctions during depressive episodes. These dysfunctions partially remain immediately after remission from a depressive state; however, it is unclear whether these residual memory dysfunctions may disappear through long-term remission from depression. The present study compared patients during early-life (agelife (age ≥ 60) depression while in their remitted stage with healthy controls to elucidate the impact of a long-term course on memory. Logical memory from the Wechsler Memory Scale-Revised was administered to 67 patients with major depressive disorder (MDD) (47 patients with early-life depression and residual 20 patients with late-life depression) and 50 healthy controls. MDD patients received memory assessments at the time of their initial remission and at a follow-up three years after remission. At the time of initial remission, scores for logical memory were significantly lower in both patient groups compared to matched controls. At follow-up, memory dysfunction for early-life MDD patients disappeared, whereas scores in the late-life MDD group remained significantly lower than those of matched controls. All patients in the present study were on antidepressant medications. Our findings suggested that the progress of memory performance in late-life MDD patients may be different from early-life MDD patients. © 2013 Elsevier B.V. All rights reserved.

  4. The timing of Late Pleistocene glaciation at Mount Wilhelm, Papua New Guinea

    Science.gov (United States)

    Mills, Stephanie; Barrows, Timothy; Hope, Geoff; Pillans, Brad; Fifield, Keith

    2016-04-01

    The highlands of New Guinea were the most extensively glaciated area in the Asian tropical region during the Late Pleistocene. Evidence for glaciation is widespread on most of the mountain peaks above ~3500 m. Glacial landforms include both valley and ice cap forms, but the timing of glaciation remains constrained to only a few local areas. This paper focuses on Mount Wilhelm, which is situated in the central southern region of Papua New Guinea at 5.78°S and is the highest peak (4510 m a.s.l.) We focus on a south easterly valley (Pindaunde Valley) emanating from the peak, where large moraines indicate the maximum ice extent of a valley glacier ~5 km long. Within this extensive moraine complex, recessional moraines document the retreat of the glacier towards the summit region. In order to determine the timing of deglaciation, we collected samples for surface exposure dating using 36Cl and 10Be from diorite boulders positioned on moraine crests. The ages indicate that maximum ice extent was attained during the last glacial maximum (LGM) and that ice remained near its maximum extent until after 15 ka but persisted at higher elevations almost until the Holocene. These results are similar to those described from Mt Giluwe to the northwest of Mount Wilhelm, where an ice cap reached its maximum extent at the LGM and remained there for around 3-4,000 years. This indicates that full glacial conditions were only brief in this region of the tropics.

  5. Approximate series solution of multi-dimensional, time fractional-order (heat-like) diffusion equations using FRDTM.

    Science.gov (United States)

    Singh, Brajesh K; Srivastava, Vineet K

    2015-04-01

    The main goal of this paper is to present a new approximate series solution of the multi-dimensional (heat-like) diffusion equation with time-fractional derivative in Caputo form using a semi-analytical approach: fractional-order reduced differential transform method (FRDTM). The efficiency of FRDTM is confirmed by considering four test problems of the multi-dimensional time fractional-order diffusion equation. FRDTM is a very efficient, effective and powerful mathematical tool which provides exact or very close approximate solutions for a wide range of real-world problems arising in engineering and natural sciences, modelled in terms of differential equations.

  6. An analysis of periodic solutions of bi-directional associative memory networks with time-varying delays

    International Nuclear Information System (INIS)

    Cao Jinde; Jiang Qiuhao

    2004-01-01

    In this Letter, several sufficient conditions are derived for the existence and uniqueness of periodic oscillatory solution for bi-directional associative memory (BAM) networks with time-varying delays by employing a new Lyapunov functional and an elementary inequality, and all other solutions of the BAM networks converge exponentially to the unique periodic solution. These criteria are presented in terms of system parameters and have important leading significance in the design and applications of periodic neural circuits for delayed BAM. As an illustration, two numerical examples are worked out using the results obtained

  7. Analytical approximate solutions of the time-domain diffusion equation in layered slabs.

    Science.gov (United States)

    Martelli, Fabrizio; Sassaroli, Angelo; Yamada, Yukio; Zaccanti, Giovanni

    2002-01-01

    Time-domain analytical solutions of the diffusion equation for photon migration through highly scattering two- and three-layered slabs have been obtained. The effect of the refractive-index mismatch with the external medium is taken into account, and approximate boundary conditions at the interface between the diffusive layers have been considered. A Monte Carlo code for photon migration through a layered slab has also been developed. Comparisons with the results of Monte Carlo simulations showed that the analytical solutions correctly describe the mean path length followed by photons inside each diffusive layer and the shape of the temporal profile of received photons, while discrepancies are observed for the continuous-wave reflectance or transmittance.

  8. Early and late motherhood

    DEFF Research Database (Denmark)

    Christoffersen, Mogens; Lausten, Mette

    2009-01-01

    The study investigates parental child rearing methods, structural factors relating to the family during adolescence geographic segregation, individual resource deficits and social background of first time late live births among 32 to 37 years old women and compare to teenagers before becoming...... economic and social gradient for first-time teenage mothers. Teenagers who had experienced family separation or who were formerly in out-of-home care in particular had an increased risk of early childbearing. Results showed that teenage mothers were in every respect in a more disadvantaged position than...

  9. Geology and geologic history of the Moscow-Pullman basin, Idaho and Washington, from late Grande Ronde to late Saddle Mountains time

    Science.gov (United States)

    Bush, John H; Garwood, Dean L; Dunlap, Pamela

    2016-01-01

    stratigraphic well data; outlines paleogeographic basin evolution from late Grande Ronde to the present time; and notes structures, basin margin differences, and features that influence upper aquifer water supply.

  10. Continuous time random walk analysis of solute transport in fractured porous media

    Energy Technology Data Exchange (ETDEWEB)

    Cortis, Andrea; Cortis, Andrea; Birkholzer, Jens

    2008-06-01

    The objective of this work is to discuss solute transport phenomena in fractured porous media, where the macroscopic transport of contaminants in the highly permeable interconnected fractures can be strongly affected by solute exchange with the porous rock matrix. We are interested in a wide range of rock types, with matrix hydraulic conductivities varying from almost impermeable (e.g., granites) to somewhat permeable (e.g., porous sandstones). In the first case, molecular diffusion is the only transport process causing the transfer of contaminants between the fractures and the matrix blocks. In the second case, additional solute transfer occurs as a result of a combination of advective and dispersive transport mechanisms, with considerable impact on the macroscopic transport behavior. We start our study by conducting numerical tracer experiments employing a discrete (microscopic) representation of fractures and matrix. Using the discrete simulations as a surrogate for the 'correct' transport behavior, we then evaluate the accuracy of macroscopic (continuum) approaches in comparison with the discrete results. However, instead of using dual-continuum models, which are quite often used to account for this type of heterogeneity, we develop a macroscopic model based on the Continuous Time Random Walk (CTRW) framework, which characterizes the interaction between the fractured and porous rock domains by using a probability distribution function of residence times. A parametric study of how CTRW parameters evolve is presented, describing transport as a function of the hydraulic conductivity ratio between fractured and porous domains.

  11. Late Carboniferous to Late Permian carbon isotope stratigraphy

    DEFF Research Database (Denmark)

    Buggisch, Werner; Krainer, Karl; Schaffhauser, Maria

    2015-01-01

    An integrated study of the litho-, bio-, and isotope stratigraphy of carbonates in the Southern Alps was undertaken in order to better constrain δ13C variations during the Late Carboniferous to Late Permian. The presented high resolution isotope curves are based on 1299 δ13Ccarb and 396 δ13Corg...

  12. Late replication domains are evolutionary conserved in the Drosophila genome.

    Science.gov (United States)

    Andreyenkova, Natalya G; Kolesnikova, Tatyana D; Makunin, Igor V; Pokholkova, Galina V; Boldyreva, Lidiya V; Zykova, Tatyana Yu; Zhimulev, Igor F; Belyaeva, Elena S

    2013-01-01

    Drosophila chromosomes are organized into distinct domains differing in their predominant chromatin composition, replication timing and evolutionary conservation. We show on a genome-wide level that genes whose order has remained unaltered across 9 Drosophila species display late replication timing and frequently map to the regions of repressive chromatin. This observation is consistent with the existence of extensive domains of repressive chromatin that replicate extremely late and have conserved gene order in the Drosophila genome. We suggest that such repressive chromatin domains correspond to a handful of regions that complete replication at the very end of S phase. We further demonstrate that the order of genes in these regions is rarely altered in evolution. Substantial proportion of such regions significantly coincide with large synteny blocks. This indicates that there are evolutionary mechanisms maintaining the integrity of these late-replicating chromatin domains. The synteny blocks corresponding to the extremely late-replicating regions in the D. melanogaster genome consistently display two-fold lower gene density across different Drosophila species.

  13. Time-dependent solutions for stochastic systems with delays: Perturbation theory and applications to financial physics

    International Nuclear Information System (INIS)

    Frank, T.D.

    2006-01-01

    First-order approximations of time-dependent solutions are determined for stochastic systems perturbed by time-delayed feedback forces. To this end, the theory of delay Fokker-Planck equations is applied in combination with Bayes' theorem. Applications to a time-delayed Ornstein-Uhlenbeck process and the geometric Brownian walk of financial physics are discussed

  14. Analytical solution for beam with time-dependent boundary conditions versus response spectrum

    International Nuclear Information System (INIS)

    Gou, P.F.; Panahi, K.K.

    2001-01-01

    This paper studies the responses of a uniform simple beam for which the supports are subjected to time-dependent conditions. Analytical solution in terms of series was presented for two cases: (1) Two supports of a simple beam are subjected to a harmonic motion, and (2) One of the two supports is stationary while the other is subjected to a harmonic motion. The results of the analytical solution were investigated and compared with the results of conventional response spectrum method using the beam finite element model. One of the applications of the results presented in this paper can be used to assess the adequacy and accuracy of the engineering approaches such as response spectra methods. It has been found that, when the excitation frequency equals the fundamental frequency of the beam, the results from response spectrum method are in good agreement with the exact calculation. The effects of initial conditions on the responses are also examined. It seems that the non-zero initial velocity has pronounced effects on the displacement time histories but it has no effect on the maximum accelerations. (author)

  15. Consistent left-right asymmetry cannot be established by late organizers in Xenopus unless the late organizer is a conjoined twin.

    Science.gov (United States)

    Vandenberg, Laura N; Levin, Michael

    2010-04-01

    How embryos consistently orient asymmetries of the left-right (LR) axis is an intriguing question, as no macroscopic environmental cues reliably distinguish left from right. Especially unclear are the events coordinating LR patterning with the establishment of the dorsoventral (DV) axes and midline determination in early embryos. In frog embryos, consistent physiological and molecular asymmetries manifest by the second cell cleavage; however, models based on extracellular fluid flow at the node predict correct de novo asymmetry orientation during neurulation. We addressed these issues in Xenopus embryos by manipulating the timing and location of dorsal organizer induction: the primary dorsal organizer was ablated by UV irradiation, and a new organizer was induced at various locations, either early, by mechanical rotation, or late, by injection of lithium chloride (at 32 cells) or of the transcription factor XSiamois (which functions after mid-blastula transition). These embryos were then analyzed for the position of three asymmetric organs. Whereas organizers rescued before cleavage properly oriented the LR axis 90% of the time, organizers induced in any position at any time after the 32-cell stage exhibited randomized laterality. Late organizers were unable to correctly orient the LR axis even when placed back in their endogenous location. Strikingly, conjoined twins produced by late induction of ectopic organizers did have normal asymmetry. These data reveal that although correct LR orientation must occur no later than early cleavage stages in singleton embryos, a novel instructive influence from an early organizer can impose normal asymmetry upon late organizers in the same cell field.

  16. Rational solutions of the discrete time Toda lattice and the alternate discrete Painleve II equation

    International Nuclear Information System (INIS)

    Common, Alan K; Hone, Andrew N W

    2008-01-01

    The Yablonskii-Vorob'ev polynomials y n (t), which are defined by a second-order bilinear differential-difference equation, provide rational solutions of the Toda lattice. They are also polynomial tau-functions for the rational solutions of the second Painleve equation (P II ). Here we define two-variable polynomials Y n (t, h) on a lattice with spacing h, by considering rational solutions of the discrete time Toda lattice as introduced by Suris. These polynomials are shown to have many properties that are analogous to those of the Yablonskii-Vorob'ev polynomials, to which they reduce when h = 0. They also provide rational solutions for a particular discretization of P II , namely the so-called alternate discrete P II , and this connection leads to an expression in terms of the Umemura polynomials for the third Painleve equation (P III ). It is shown that the Baecklund transformation for the alternate discrete Painleve equation is a symplectic map, and the shift in time is also symplectic. Finally we present a Lax pair for the alternate discrete P II , which recovers Jimbo and Miwa's Lax pair for P II in the continuum limit h → 0

  17. Abiotic landscape and vegetation patterns in the Netherlands during the Weichselian Late Glacial

    NARCIS (Netherlands)

    Hoek, W.Z.

    2000-01-01

    The Late Glacial landscape of the Netherlands was a landscape with changing geomorphology and vegetation. Glacial, eolian and fluvial processes in the time before the Late Glacial initially had formed the main landscape types that still existed during the Late Glacial. In these landscape types,

  18. Exact self-consistent solutions to the interacting spinor and scalar field equations in Bianchi type-I space-time

    International Nuclear Information System (INIS)

    Alvarado, R.; Rybakov, Yu.P.; Shikin, G.N.; Saha, B.

    1995-01-01

    Self-consistent solutions to the system of spinor and scalar field equations in General Relativity are studied for the case of Bianchi type-I space-time. The absence of initial singularity should be emphasized for some types of solutions and also the isotropic mode of space-time expansion in some special cases. 3 refs

  19. Dimensionality dependence of the Rayleigh-Taylor and Richtmyer-Meshkov instability late-time scaling laws

    International Nuclear Information System (INIS)

    Oron, D.; Arazi, L.; Kartoon, D.; Rikanati, A.; Alon, U.; Shvarts, D.

    2001-01-01

    The late-time nonlinear evolution of the three-dimensional (3D) Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities for random initial perturbations is investigated. Using full 3D numerical simulations, a statistical mechanics bubble-competition model, and a Layzer-type drag-buoyancy model, it is shown that the RT scaling parameters, α B and α S , are similar in two and three dimensions, but the RM exponents, θ B and θ S are lower by a factor of 2 in three dimensions. The similarity parameter h B / is higher by a factor of 3 in the 3D case compared to the 2D case, in very good agreement with recent Linear Electric Motor (LEM) experiments. A simple drag-buoyancy model, similar to that proposed by Youngs [see J. C. V. Hanson et al., Laser Part. Beams 8, 51 (1990)], but using the coefficients from the A=1 Layzer model, rather than phenomenological ones, is introduced

  20. Approximate analytical solution of diffusion equation with fractional time derivative using optimal homotopy analysis method

    Directory of Open Access Journals (Sweden)

    S. Das

    2013-12-01

    Full Text Available In this article, optimal homotopy-analysis method is used to obtain approximate analytic solution of the time-fractional diffusion equation with a given initial condition. The fractional derivatives are considered in the Caputo sense. Unlike usual Homotopy analysis method, this method contains at the most three convergence control parameters which describe the faster convergence of the solution. Effects of parameters on the convergence of the approximate series solution by minimizing the averaged residual error with the proper choices of parameters are calculated numerically and presented through graphs and tables for different particular cases.

  1. Late malignant transformation of vestibular schwannoma in the absence of irradiation

    DEFF Research Database (Denmark)

    Bashir, Asma; Poulsgaard, Lars; Broholm, Helle

    2016-01-01

    Late malignant transformation of vestibular schwannoma (VS) following irradiation has previously been reported 29 times in the literature. Here, the authors report the first late malignant transformation of VS unrelated to neurofibromatosis or radiation exposure. After undergoing a near-total exc...

  2. Transit time dispersion in pulmonary and systemic circulation: effects of cardiac output and solute diffusivity.

    Science.gov (United States)

    Weiss, Michael; Krejcie, Tom C; Avram, Michael J

    2006-08-01

    We present an in vivo method for analyzing the distribution kinetics of physiological markers into their respective distribution volumes utilizing information provided by the relative dispersion of transit times. Arterial concentration-time curves of markers of the vascular space [indocyanine green (ICG)], extracellular fluid (inulin), and total body water (antipyrine) measured in awake dogs under control conditions and during phenylephrine or isoproterenol infusion were analyzed by a recirculatory model to estimate the relative dispersions of transit times across the systemic and pulmonary circulation. The transit time dispersion in the systemic circulation was used to calculate the whole body distribution clearance, and an interpretation is given in terms of a lumped organ model of blood-tissue exchange. As predicted by theory, this relative dispersion increased linearly with cardiac output, with a slope that was inversely related to solute diffusivity. The relative dispersion of the flow-limited indicator antipyrine exceeded that of ICG (as a measure of intravascular mixing) only slightly and was consistent with a diffusional equilibration time in the extravascular space of approximately 10 min, except during phenylephrine infusion, which led to an anomalously high relative dispersion. A change in cardiac output did not alter the heterogeneity of capillary transit times of ICG. The results support the view that the relative dispersions of transit times in the systemic and pulmonary circulation estimated from solute disposition data in vivo are useful measures of whole body distribution kinetics of indicators and endogenous substances. This is the first model that explains the effect of flow and capillary permeability on whole body distribution of solutes without assuming well-mixed compartments.

  3. Use of ethonium in the treatment of late radiation injuries of the skin, radiation cystitis and rectitis

    International Nuclear Information System (INIS)

    Bardychev, M.S.; Kurpesheva, A.K.; Petrik, V.D.

    1979-01-01

    Conducted has been investigation of therapeutic effectiveness of ethonium in 71 patients of late radiation injuries of the skin, urinary bladder and rectum. Local radiation injuries developed after radiotherapy of malignant tumours. Shown is comparatively low effectiveness of application of 0.5-2 % aqueous solutions and 2 % ethonium ointment in the expressed necrotic-inflammatory process in radiation ulcer of skin and its expressed effectiveness at granulating late radiation ulcers of skin. Application of 0.02-0.05 % ethonium solution in the form of microclusters and suppositories of 0.05 g of the preparation proved to be effective at catarrhal rectitis and rectosigmoids. An attempt to treat radiation cyctitis aroused aggravation of the inflammatory process of the mucous membrane off the ucinary bladder

  4. Late time optical spectra from the 56Ni model for Type I supernovae

    International Nuclear Information System (INIS)

    Axelrod, T.S.

    1980-07-01

    The hypothesis that the optical luminosity of Type I supernovae results from the radioactive decay of 56 Ni synthesized and ejected by the explosion has been investigated by numerical simulation of the optical spectrum resulting from a homologously expanding shell composed initially of pure 56 Ni core. This model, which neglects the effects of material external to the 56 Ni core, is expected to provide a reasonable representation of the supernova at late times when the star is nearly transparent to optical photons. The numerical simulation determines the temperature, ionization state, and non-LTE level populations which result from energy deposition by the radioactive decay products of 56 Ni and 56 Co. The optical spectrum includes the effects of both allowed and forbidden lines. The optical spectra resulting from the simulation are found to be sensitive to the mass and ejection velocity of the 56 Ni shell. A range of these parameters has been found which results in good agreement with the observed spectra of SN1972e over a considerable range of time. In particular, evidence for the expected decaying abundance of 56 Co has been found in the spectra of SN1972e. These results are used to assess the validity of the 56 Ni model and set limits on the mass and explosion mechanism of the Type I progenitor. The possibilities for improvement of the numerical model are discussed and future atomic data requirements defined

  5. Lie symmetry analysis, exact solutions and conservation laws for the time fractional Caudrey-Dodd-Gibbon-Sawada-Kotera equation

    Science.gov (United States)

    Baleanu, Dumitru; Inc, Mustafa; Yusuf, Abdullahi; Aliyu, Aliyu Isa

    2018-06-01

    In this work, we investigate the Lie symmetry analysis, exact solutions and conservation laws (Cls) to the time fractional Caudrey-Dodd-Gibbon-Sawada-Kotera (CDGDK) equation with Riemann-Liouville (RL) derivative. The time fractional CDGDK is reduced to nonlinear ordinary differential equation (ODE) of fractional order. New exact traveling wave solutions for the time fractional CDGDK are obtained by fractional sub-equation method. In the reduced equation, the derivative is in Erdelyi-Kober (EK) sense. Ibragimov's nonlocal conservation method is applied to construct Cls for time fractional CDGDK.

  6. Effect of Dissolved Oxygen and Immersion Time on the Corrosion Behaviour of Mild Steel in Bicarbonate/Chloride Solution

    Directory of Open Access Journals (Sweden)

    Gaius Debi Eyu

    2016-09-01

    Full Text Available The electrochemical behavior of mild steel in bicarbonate solution at different dissolved oxygen (DO concentrations and immersion times has been studied under dynamic conditions using electrochemical techniques. The results show that both DO and immersion times influence the morphology of the corrosion products. In comparative tests, the corrosion rate was systematically found to be lower in solutions with lower DO, lower HCO3− concentrations and longer immersion time. The SEM analyses reveal that the iron dissolution rate was more severe in solutions containing higher DO. The decrease in corrosion rate can be attributed to the formation of a passive layer containing mainly α -FeO (OH and ( γ -Fe2O3/Fe3O4 as confirmed by the X-ray diffractometry (XRD and X-ray photoelectron spectroscopy (XPS. Passivation of mild steel is evident in electrochemical test at ≈ −600 mVSCE at pH ≥ 8 in dearated ( ≤ 0.8 ppm DO chloride bicarbonate solution under dynamic conditions.

  7. Late Cretaceous vicariance in Gondwanan amphibians.

    Directory of Open Access Journals (Sweden)

    Ines Van Bocxlaer

    Full Text Available Overseas dispersals are often invoked when Southern Hemisphere terrestrial and freshwater organism phylogenies do not fit the sequence or timing of Gondwana fragmentation. We used dispersal-vicariance analyses and molecular timetrees to show that two species-rich frog groups, Microhylidae and Natatanura, display congruent patterns of spatial and temporal diversification among Gondwanan plates in the Late Cretaceous, long after the presumed major tectonic break-up events. Because amphibians are notoriously salt-intolerant, these analogies are best explained by simultaneous vicariance, rather than by oceanic dispersal. Hence our results imply Late Cretaceous connections between most adjacent Gondwanan landmasses, an essential concept for biogeographic and palaeomap reconstructions.

  8. A Solution of Time Dependent Schrodinger Equation by Quantum Walk

    International Nuclear Information System (INIS)

    Sekino, Hideo; Kawahata, Masayuki; Hamada, Shinji

    2012-01-01

    Time Dependent Schroedinger Equation (TDSE) with an initial Gaussian distribution, is solved by a discrete time/space Quantum Walk (QW) representing consecutive operations corresponding to a dot product of Pauli matrix and momentum operators. We call it as Schroedinger Walk (SW). Though an Hadamard Walk (HW) provides same dynamics of the probability distribution for delta-function-like initial distributions as that of the SW with a delta-function-like initial distribution, the former with a Gaussian initial distribution leads to a solution for advection of the probability distribution; the initial distribution splits into two distinctive distributions moving in opposite directions. Both mechanisms are analysed by investigating the evolution of the both amplitude components. Decoherence of the oscillating amplitudes in central region is found to be responsible for the splitting of the probability distribution in the HW.

  9. Cross-Sectional Analysis of Late HAART Initiation in Latin America and the Caribbean: Late Testers and Late Presenters

    Science.gov (United States)

    Crabtree-Ramírez, Brenda; Caro-Vega, Yanink; Shepherd, Bryan E.; Wehbe, Firas; Cesar, Carina; Cortés, Claudia; Padgett, Denis; Koenig, Serena; Gotuzzo, Eduardo; Cahn, Pedro; McGowan, Catherine; Masys, Daniel; Sierra-Madero, Juan

    2011-01-01

    Background Starting HAART in a very advanced stage of disease is assumed to be the most prevalent form of initiation in HIV-infected subjects in developing countries. Data from Latin America and the Caribbean is still lacking. Our main objective was to determine the frequency, risk factors and trends in time for being late HAART initiator (LHI) in this region. Methodology Cross-sectional analysis from 9817 HIV-infected treatment-naïve patients initiating HAART at 6 sites (Argentina, Chile, Haiti, Honduras, Peru and Mexico) from October 1999 to July 2010. LHI had CD4+ count ≤200cells/mm3 prior to HAART. Late testers (LT) were those LHI who initiated HAART within 6 months of HIV diagnosis. Late presenters (LP) initiated after 6 months of diagnosis. Prevalence, risk factors and trends over time were analyzed. Principal Findings Among subjects starting HAART (n = 9817) who had baseline CD4+ available (n = 8515), 76% were LHI: Argentina (56%[95%CI:52–59]), Chile (80%[95%CI:77–82]), Haiti (76%[95%CI:74–77]), Honduras (91%[95%CI:87–94]), Mexico (79%[95%CI:75–83]), Peru (86%[95%CI:84–88]). The proportion of LHI statistically changed over time (except in Honduras) (p≤0.02; Honduras p = 0.7), with a tendency towards lower rates in recent years. Males had increased risk of LHI in Chile, Haiti, Peru, and in the combined site analyses (CSA). Older patients were more likely LHI in Argentina and Peru (OR 1.21 per +10-year of age, 95%CI:1.02–1.45; OR 1.20, 95%CI:1.02–1.43; respectively), but not in CSA (OR 1.07, 95%CI:0.94–1.21). Higher education was associated with decreased risk for LHI in Chile (OR 0.92 per +1-year of education, 95%CI:0.87–0.98) (similar trends in Mexico, Peru, and CSA). LHI with date of HIV-diagnosis available, 55% were LT and 45% LP. Conclusion LHI was highly prevalent in CCASAnet sites, mostly due to LT; the main risk factors associated were being male and older age. Earlier HIV-diagnosis and earlier treatment initiation

  10. New solutions for the short-time analysis of geothermal vertical boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Lamarche, Louis; Beauchamp, Benoit [Ecole de Technologie Supereure, 1100 Notre-Dame Ouest, Montreal (Canada)

    2007-04-15

    Many models, either numerical or analytical, have been proposed to analyse the thermal response of vertical heat exchangers that are used in ground coupled heat pump systems (GCHP). In both approaches, most of the models are valid after few hours of operation since they neglect the heat capacity of the borehole. This is valid for design purposes, where the time of interest is in the order of months and years. Recently, the short time response of vertical boreholes became a subject of interest. In this paper, we present a new analytical approach to treat this problem. It solves the exact solution for concentric cylinders and is a good approximation for the familiar U-tube configuration. (author)

  11. Lie Group Classifications and Non-differentiable Solutions for Time-Fractional Burgers Equation

    International Nuclear Information System (INIS)

    Wu Guocheng

    2011-01-01

    Lie group method provides an efficient tool to solve nonlinear partial differential equations. This paper suggests Lie group method for fractional partial differential equations. A time-fractional Burgers equation is used as an example to illustrate the effectiveness of the Lie group method and some classes of exact solutions are obtained. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  12. Abundant closed form solutions of the conformable time fractional Sawada-Kotera-Ito equation using (G‧ / G) -expansion method

    Science.gov (United States)

    Al-Shawba, Altaf Abdulkarem; Gepreel, K. A.; Abdullah, F. A.; Azmi, A.

    2018-06-01

    In current study, we use the (G‧ / G) -expansion method to construct the closed form solutions of the seventh order time fractional Sawada-Kotera-Ito (TFSKI) equation based on conformable fractional derivative. As a result, trigonometric, hyperbolic and rational functions solutions with arbitrary constants are obtained. When the arbitrary constants are taken some special values, the periodic and soliton solutions are obtained from the travelling wave solutions. The obtained solutions are new and not found elsewhere. The effect of the fractional order on some of these solutions are represented graphically to illustrate the behavior of the exact solutions when the parameter take some special choose.

  13. Spinor Field Nonlinearity and Space-Time Geometry

    Science.gov (United States)

    Saha, Bijan

    2018-03-01

    Within the scope of Bianchi type VI,VI0,V, III, I, LRSBI and FRW cosmological models we have studied the role of nonlinear spinor field on the evolution of the Universe and the spinor field itself. It was found that due to the presence of non-trivial non-diagonal components of the energy-momentum tensor of the spinor field in the anisotropic space-time, there occur some severe restrictions both on the metric functions and on the components of the spinor field. In this report we have considered a polynomial nonlinearity which is a function of invariants constructed from the bilinear spinor forms. It is found that in case of a Bianchi type-VI space-time, depending of the sign of self-coupling constants, the model allows either late time acceleration or oscillatory mode of evolution. In case of a Bianchi VI 0 type space-time due to the specific behavior of the spinor field we have two different scenarios. In one case the invariants constructed from bilinear spinor forms become trivial, thus giving rise to a massless and linear spinor field Lagrangian. This case is equivalent to the vacuum solution of the Bianchi VI 0 type space-time. The second case allows non-vanishing massive and nonlinear terms and depending on the sign of coupling constants gives rise to accelerating mode of expansion or the one that after obtaining some maximum value contracts and ends in big crunch, consequently generating space-time singularity. In case of a Bianchi type-V model there occur two possibilities. In one case we found that the metric functions are similar to each other. In this case the Universe expands with acceleration if the self-coupling constant is taken to be a positive one, whereas a negative coupling constant gives rise to a cyclic or periodic solution. In the second case the spinor mass and the spinor field nonlinearity vanish and the Universe expands linearly in time. In case of a Bianchi type-III model the space-time remains locally rotationally symmetric all the time

  14. Multi-wave solutions of the space–time fractional Burgers and Sharma–Tasso–Olver equations

    OpenAIRE

    Emad A.-B. Abdel-Salam; Gamal F. Hassan

    2016-01-01

    Based on the improved generalized exp-function method, the space–time fractional Burgers and Sharma–Tasso–Olver equations were studied. The single-wave, double-wave, three-wave and four-wave solution discussed. With the best of our knowledge, some of the results are obtained for the first time. The improved generalized exp-function method can be applied to other fractional differential equations.

  15. Late induced abortion.

    Science.gov (United States)

    Savage, W

    1990-09-01

    In the UK in 1988, 13.3% of abortions were performed at 13 weeks' gestation or later. Reasons for this delay, in addition to the diagnosis through amniocentesis of a fetal abnormality, include late recognition of pregnancy, a change of mind about completing the pregnancy, a failure of primary care physicians to entertain the diagnosis of pregnancy, travel or financial problems, and referral difficulties and scheduling delays. Women with little education and very young women are most likely to present for late abortions. From 13-16 weeks, dilatation and evacuation is the safest method of pregnancy termination. The procedure can be made easier through preparation of the cervix with a prostaglandin pessary or Foley catheter. After 16 weeks, an instillation method is recommended; prostaglandin administration can be intro- or extra-amniotic. Complication rates at 13-19 weeks are 14.5/1000 for vaginal methods of abortion and 7.2/1000 for prostaglandin methods. The risk of complications is 3 times higher for women who have 2nd-trimester abortions through the National Health Service. Although it is not realistic to expect that late abortions ever can be eliminated, improved sex education and contraceptive reliability as well as reforms in the National Health Service could reduce the number substantially. To reduce delay, it is suggested that the National Health Service set up satellite day care units and 1-2 central units in each region to deal quickly with midtrimester abortions. Delays would be further reduced by legislation to allow abortion on request in at least the 1st trimester of pregnancy.

  16. Periodic Solution of Second-Order Hamiltonian Systems with a Change Sign Potential on Time Scales

    Directory of Open Access Journals (Sweden)

    You-Hui Su

    2009-01-01

    Full Text Available This paper is concerned with the second-order Hamiltonian system on time scales 𝕋 of the form uΔΔ(ρ(t+μb(t|u(t|μ−2u(t+∇¯H(t,u(t=0, Δ-a.e. t∈[0,T]𝕋 , u(0−u(T=uΔ(ρ(0−uΔ(ρ(T=0, where 0,T∈𝕋. By using the minimax methods in critical theory, an existence theorem of periodic solution for the above system is established. As an application, an example is given to illustrate the result. This is probably the first time the existence of periodic solutions for second-order Hamiltonian system on time scales has been studied by critical theory.

  17. A note on the time decay of solutions for the linearized Wigner-Poisson system

    KAUST Repository

    Gamba, Irene; Gualdani, Maria; Sparber, Christof

    2009-01-01

    We consider the one-dimensional Wigner-Poisson system of plasma physics, linearized around a (spatially homogeneous) Lorentzian distribution and prove that the solution of the corresponding linearized problem decays to zero in time. We also give

  18. Fast solution of Cahn–Hilliard variational inequalities using implicit time discretization and finite elements

    KAUST Repository

    Bosch, Jessica; Stoll, Martin; Benner, Peter

    2014-01-01

    We consider the efficient solution of the Cahn-Hilliard variational inequality using an implicit time discretization, which is formulated as an optimal control problem with pointwise constraints on the control. By applying a semi-smooth Newton

  19. The existence and global attractivity of almost periodic sequence solution of discrete-time neural networks

    International Nuclear Information System (INIS)

    Huang Zhenkun; Wang Xinghua; Gao Feng

    2006-01-01

    In this Letter, we discuss discrete-time analogue of a continuous-time cellular neural network. Sufficient conditions are obtained for the existence of a unique almost periodic sequence solution which is globally attractive. Our results demonstrate dynamics of the formulated discrete-time analogue as mathematical models for the continuous-time cellular neural network in almost periodic case. Finally, a computer simulation illustrates the suitability of our discrete-time analogue as numerical algorithms in simulating the continuous-time cellular neural network conveniently

  20. Origin and mixing timescale of Earth's late veneer

    Science.gov (United States)

    Prescher, C.; Allu Peddinti, D.; Bell, E. A.; Bello, L.; Cernok, A.; Ghosh, N.; Tucker, J.; Wielicki, M. M.; Zahnle, K. J.

    2012-12-01

    Experimental studies on the partitioning behavior of highly siderophile elements (HSE) between silicate and metallic melts imply that the Earth's mantle should have been highly depleted in these elements by core formation in an early magma ocean. However, present HSE contents of the Earth's mantle are ~3 orders of magnitude higher than that expected by experiments. The apparent over-abundance of HSE has commonly been explained by the addition of meteoritic material in the "late veneer" which describes the exogenous mass addition following the moon forming impact and concluding with the late heavy bombardment at ~3.8-3.9 Ga. The strongest evidence for this theory is that the platinum group element (PGE) contents in today's mantle are present in chondritic relative abundances, as opposed to a fractionated pattern expected with metal-silicate partitioning. Archean komatiites indicate that the PGE content of the Earth's mantle increased from about half their present abundances at 3.5 Ga to their present abundances at 2.9 Ga. This secular increase in PGE content suggests a progressive mixing of the late veneer material into the Earth's mantle. However, this time scale also implies that the whole mantle was relatively well mixed by 2.9 Ga. We use a compilation of existing isotopic and trace element data in order to constrain the origin and composition of the late veneer. We use PGE abundances, W abundances and W isotopic compositions in chondritic meteorites and the primitive upper mantle to compute the amount of mass delivered during the late veneer and find the late veneer mass to be ~0.6 % the mass of the bulk silicate Earth (consistent with earlier estimates). We also use the 187Re-187Os and 190Pt-186Os systems to constrain the composition and timing of delivery of the impacting population. We model the efficiency of mantle mixing in this time frame by using 3-dimensional numerical geodynamical simulations and geochemical constraints. Initial parameters include the

  1. The Development of a Questionnaire on Academic Hardiness for Late Elementary School Children

    Science.gov (United States)

    Kamtsios, Spiridon; Karagiannopoulou, Evangelia

    2013-01-01

    The purpose of the research was to develop a questionnaire to measure dimensions of academic hardiness in late elementary school children. Questionnaires were distributed to 1474 children. After a set of exploratory factor analyses in studies 1 and 2, the confirmatory factor analysis results provided support for the 9-factor solution which…

  2. Analytical solutions to time-fractional partial differential equations in a two-dimensional multilayer annulus

    Science.gov (United States)

    Chen, Shanzhen; Jiang, Xiaoyun

    2012-08-01

    In this paper, analytical solutions to time-fractional partial differential equations in a multi-layer annulus are presented. The final solutions are obtained in terms of Mittag-Leffler function by using the finite integral transform technique and Laplace transform technique. In addition, the classical diffusion equation (α=1), the Helmholtz equation (α→0) and the wave equation (α=2) are discussed as special cases. Finally, an illustrative example problem for the three-layer semi-circular annular region is solved and numerical results are presented graphically for various kind of order of fractional derivative.

  3. Comment on 'Late-time tails of a self-gravitating massless scalar field revisited'

    International Nuclear Information System (INIS)

    Szpak, Nikodem

    2009-01-01

    Bizon et al (2009 Class. Quantum Grav. 26 175006) discuss the power-law tail in the long-time evolution of a spherically symmetric self-gravitating massless scalar field in odd spatial dimensions. They derive explicit expressions for the leading-order asymptotics for solutions with small initial data by using formal series expansions. Unfortunately, this approach misses an interesting observation that the actual decay rate is a product of asymptotic cancellations occurring due to a special structure of the nonlinear terms. Here, we show that one can calculate the leading asymptotics more directly by recognizing the special structure and cancellations already on the level of the wave equation. (comments and replies)

  4. Sirtinol abrogates late phase of cardiac ischemia preconditioning in rats.

    Science.gov (United States)

    Safari, Fereshteh; Shekarforoosh, Shahnaz; Hashemi, Tahmineh; Namvar Aghdash, Simin; Fekri, Asefeh; Safari, Fatemeh

    2017-07-01

    The aim of this study was to investigate the effect of sirtinol, as an inhibitor of sirtuin NAD-dependent histone deacetylases, on myocardial ischemia reperfusion injury following early and late ischemia preconditioning (IPC). Rats underwent sustained ischemia and reperfusion (IR) alone or proceeded by early or late IPC. Sirtinol (S) was administered before IPC. Arrhythmias were evaluated based on the Lambeth model. Infarct size (IS) was measured using triphenyltetrazolium chloride staining. The transcription level of antioxidant-coding genes was assessed by real-time PCR. In early and late IPC groups, IS and the number of arrhythmia were significantly decreased (P < 0.05 and P < 0.01 vs IR, respectively). In S + early IPC, incidences of arrhythmia and IS were not different compared with the early IPC group. However, in S + late IPC the IS was different from the late IPC group (P < 0.05). In late IPC but not early IPC, transcription levels of catalase (P < 0.01) and Mn-SOD (P < 0.05) increased, although this upregulation was not significant in the S + late IPC group. Our results are consistent with the notion that different mechanisms are responsible for early and late IPC. In addition, sirtuin NAD-dependent histone deacetylases may be implicated in late IPC-induced cardioprotection.

  5. Lie symmetry analysis, explicit solutions and conservation laws for the space-time fractional nonlinear evolution equations

    Science.gov (United States)

    Inc, Mustafa; Yusuf, Abdullahi; Aliyu, Aliyu Isa; Baleanu, Dumitru

    2018-04-01

    This paper studies the symmetry analysis, explicit solutions, convergence analysis, and conservation laws (Cls) for two different space-time fractional nonlinear evolution equations with Riemann-Liouville (RL) derivative. The governing equations are reduced to nonlinear ordinary differential equation (ODE) of fractional order using their Lie point symmetries. In the reduced equations, the derivative is in Erdelyi-Kober (EK) sense, power series technique is applied to derive an explicit solutions for the reduced fractional ODEs. The convergence of the obtained power series solutions is also presented. Moreover, the new conservation theorem and the generalization of the Noether operators are developed to construct the nonlocal Cls for the equations . Some interesting figures for the obtained explicit solutions are presented.

  6. Time dependent solutions of the Fokker-Planck equation for fast fusion ions

    International Nuclear Information System (INIS)

    Gnavi, G.; Gratton, F.T.; Heyn, M.

    1990-01-01

    Approximate time dependent solutions for the Fokker-Planck equation for fast fusion ions from an isotropic, monoenergetic source are presented, for the problem of D - T - He 3 reactions. The equations include the effect of diffusion, which is particularly noticeable in the distribution of particles of lower energy and in the formation of a tail of particles with energy higher than that of the source. (Author)

  7. Multi-wave solutions of the space–time fractional Burgers and Sharma–Tasso–Olver equations

    Directory of Open Access Journals (Sweden)

    Emad A.-B. Abdel-Salam

    2016-03-01

    Full Text Available Based on the improved generalized exp-function method, the space–time fractional Burgers and Sharma–Tasso–Olver equations were studied. The single-wave, double-wave, three-wave and four-wave solution discussed. With the best of our knowledge, some of the results are obtained for the first time. The improved generalized exp-function method can be applied to other fractional differential equations.

  8. Time-Homogeneous Parabolic Wick-Anderson Model in One Space Dimension: Regularity of Solution

    OpenAIRE

    Kim, Hyun-Jung; Lototsky, Sergey V

    2017-01-01

    Even though the heat equation with random potential is a well-studied object, the particular case of time-independent Gaussian white noise in one space dimension has yet to receive the attention it deserves. The paper investigates the stochastic heat equation with space-only Gaussian white noise on a bounded interval. The main result is that the space-time regularity of the solution is the same for additive noise and for multiplicative noise in the Wick-It\\^o-Skorokhod interpretation.

  9. How do you manage early or late clock-ins? .

    Science.gov (United States)

    Marlowe, Cathy L

    2013-08-01

    My current practice has historically been very strict with hourly employees. The workday is 8:30 a.m. to 5 p.m. for most employees. They are to clock in and out at exactly those times unless overtime has been approved. (Staff working with late patients are exempt.) My business manager is constantly fighting over clock-ins 15 to 20 minutes early or late, with similar clock-outs. Staff may have a stop to make and would like to make up those 15 minutes. We do grant paid time off in an initial minimum block of 30 minutes to assist with some of this. ... The issue is not overtime, as we're well aware that we have to pay for it when appropriate. It's simply to streamline our policy and make it fair. ... I'm looking for practice policies that deal with employee variances from the 8 a.m. to 4:30 p.m. clock-ins. For example, someone wants to come in 30 minutes early in order to leave 30 minutes early for an appointment. Or someone comes in 22 minutes late due to traffic and wants either to make it up or to take the minimal half-hour paid-time-off time.

  10. An Analytical Solution for Transient Heat Conduction in a Composite Slab with Time-Dependent Heat Transfer Coefficient

    Directory of Open Access Journals (Sweden)

    Ryoichi Chiba

    2018-01-01

    Full Text Available An analytical solution is derived for one-dimensional transient heat conduction in a composite slab consisting of n layers, whose heat transfer coefficient on an external boundary is an arbitrary function of time. The composite slab, which has thermal contact resistance at n-1 interfaces, as well as an arbitrary initial temperature distribution and internal heat generation, convectively exchanges heat at the external boundaries with two different time-varying surroundings. To obtain the analytical solution, the shifting function method is first used, which yields new partial differential equations under conventional types of external boundary conditions. The solution for the derived differential equations is then obtained by means of an orthogonal expansion technique. Numerical calculations are performed for two composite slabs, whose heat transfer coefficient on the heated surface is either an exponential or a trigonometric function of time. The numerical results demonstrate the effects of temporal variations in the heat transfer coefficient on the transient temperature field of composite slabs.

  11. A Systematic Multi-Time Scale Solution for Regional Power Grid Operation

    Science.gov (United States)

    Zhu, W. J.; Liu, Z. G.; Cheng, T.; Hu, B. Q.; Liu, X. Z.; Zhou, Y. F.

    2017-10-01

    Many aspects need to be taken into consideration in a regional grid while making schedule plans. In this paper, a systematic multi-time scale solution for regional power grid operation considering large scale renewable energy integration and Ultra High Voltage (UHV) power transmission is proposed. In the time scale aspect, we discuss the problem from month, week, day-ahead, within-day to day-behind, and the system also contains multiple generator types including thermal units, hydro-plants, wind turbines and pumped storage stations. The 9 subsystems of the scheduling system are described, and their functions and relationships are elaborated. The proposed system has been constructed in a provincial power grid in Central China, and the operation results further verified the effectiveness of the system.

  12. Cosmology of a Friedmann-Lamaître-Robertson-Walker 3-brane, late-time cosmic acceleration, and the cosmic coincidence.

    Science.gov (United States)

    Doolin, Ciaran; Neupane, Ishwaree P

    2013-04-05

    A late epoch cosmic acceleration may be naturally entangled with cosmic coincidence--the observation that at the onset of acceleration the vacuum energy density fraction nearly coincides with the matter density fraction. In this Letter we show that this is indeed the case with the cosmology of a Friedmann-Lamaître-Robertson-Walker (FLRW) 3-brane in a five-dimensional anti-de Sitter spacetime. We derive the four-dimensional effective action on a FLRW 3-brane, from which we obtain a mass-reduction formula, namely, M(P)(2) = ρ(b)/|Λ(5)|, where M(P) is the effective (normalized) Planck mass, Λ(5) is the five-dimensional cosmological constant, and ρ(b) is the sum of the 3-brane tension V and the matter density ρ. Although the range of variation in ρ(b) is strongly constrained, the big bang nucleosynthesis bound on the time variation of the effective Newton constant G(N) = (8πM(P)(2))(-1) is satisfied when the ratio V/ρ ≳ O(10(2)) on cosmological scales. The same bound leads to an effective equation of state close to -1 at late epochs in accordance with astrophysical and cosmological observations.

  13. Tide Gauge Records Reveal Improved Processing of Gravity Recovery and Climate Experiment Time-Variable Mass Solutions over the Coastal Ocean

    Science.gov (United States)

    Piecuch, Christopher G.; Landerer, Felix W.; Ponte, Rui M.

    2018-05-01

    Monthly ocean bottom pressure solutions from the Gravity Recovery and Climate Experiment (GRACE), derived using surface spherical cap mass concentration (MC) blocks and spherical harmonics (SH) basis functions, are compared to tide gauge (TG) monthly averaged sea level data over 2003-2015 to evaluate improved gravimetric data processing methods near the coast. MC solutions can explain ≳ 42% of the monthly variance in TG time series over broad shelf regions and in semi-enclosed marginal seas. MC solutions also generally explain ˜5-32 % more TG data variance than SH estimates. Applying a coastline resolution improvement algorithm in the GRACE data processing leads to ˜ 31% more variance in TG records explained by the MC solution on average compared to not using this algorithm. Synthetic observations sampled from an ocean general circulation model exhibit similar patterns of correspondence between modeled TG and MC time series and differences between MC and SH time series in terms of their relationship with TG time series, suggesting that observational results here are generally consistent with expectations from ocean dynamics. This work demonstrates the improved quality of recent MC solutions compared to earlier SH estimates over the coastal ocean, and suggests that the MC solutions could be a useful tool for understanding contemporary coastal sea level variability and change.

  14. A note on the time decay of solutions for the linearized Wigner-Poisson system

    KAUST Repository

    Gamba, Irene

    2009-01-01

    We consider the one-dimensional Wigner-Poisson system of plasma physics, linearized around a (spatially homogeneous) Lorentzian distribution and prove that the solution of the corresponding linearized problem decays to zero in time. We also give an explicit algebraic decay rate.

  15. New Solutions of Three Nonlinear Space- and Time-Fractional Partial Differential Equations in Mathematical Physics

    International Nuclear Information System (INIS)

    Yao Ruo-Xia; Wang Wei; Chen Ting-Hua

    2014-01-01

    Motivated by the widely used ansätz method and starting from the modified Riemann—Liouville derivative together with a fractional complex transformation that can be utilized to transform nonlinear fractional partial differential equations to nonlinear ordinary differential equations, new types of exact traveling wave solutions to three important nonlinear space- and time-fractional partial differential equations are obtained simultaneously in terms of solutions of a Riccati equation. The results are new and first reported in this paper. (general)

  16. Better late than never: information retrieval from black holes.

    Science.gov (United States)

    Braunstein, Samuel L; Pirandola, Stefano; Życzkowski, Karol

    2013-03-08

    We show that, in order to preserve the equivalence principle until late times in unitarily evaporating black holes, the thermodynamic entropy of a black hole must be primarily entropy of entanglement across the event horizon. For such black holes, we show that the information entering a black hole becomes encoded in correlations within a tripartite quantum state, the quantum analogue of a one-time pad, and is only decoded into the outgoing radiation very late in the evaporation. This behavior generically describes the unitary evaporation of highly entangled black holes and requires no specially designed evolution. Our work suggests the existence of a matter-field sum rule for any fundamental theory.

  17. Gene Profiling in Late Blight Resistance in Potato Genotype SD20

    Directory of Open Access Journals (Sweden)

    Xiaohui Yang

    2018-06-01

    Full Text Available Late blight caused by the oomycete fungus Phytophthora infestans (Pi is the most serious obstacle to potato (Solanum tuberosum production in the world. A super race isolate, CN152, which was identified from Sichuan Province, China, could overcome nearly all known late blight resistance genes and caused serious damage in China. The potato genotype SD20 was verified to be highly resistant to CN152; however, the molecular regulation network underlying late blight resistance pathway remains unclear in SD20. Here, we performed a time-course experiment to systematically profile the late blight resistance response genes using RNA-sequencing in SD20. We identified 3354 differentially expressed genes (DEGs, which mainly encoded transcription factors and protein kinases, and also included four NBS-LRR genes. The late blight responsive genes showed time-point-specific induction/repression. Multi-signaling pathways of salicylic acid, jasmonic acid, and ethylene signaling pathways involved in resistance and defense against Pi in SD20. Gene Ontology and KEGG analyses indicated that the DEGs were significantly enriched in metabolic process, protein serine/threonine kinase activity, and biosynthesis of secondary metabolites. Forty-three DEGs were involved in immune response, of which 19 were enriched in hypersensitive response reaction, which could play an important role in broad-spectrum resistance to Pi infection. Experimental verification confirmed the induced expression of the responsive genes in the late blight resistance signaling pathway, such as WRKY, ERF, MAPK, and NBS-LRR family genes. Our results provided valuable information for understanding late blight resistance mechanism of potato.

  18. On the nonlinear dynamics of trolling-mode AFM: Analytical solution using multiple time scales method

    Science.gov (United States)

    Sajjadi, Mohammadreza; Pishkenari, Hossein Nejat; Vossoughi, Gholamreza

    2018-06-01

    Trolling mode atomic force microscopy (TR-AFM) has resolved many imaging problems by a considerable reduction of the liquid-resonator interaction forces in liquid environments. The present study develops a nonlinear model of the meniscus force exerted to the nanoneedle of TR-AFM and presents an analytical solution to the distributed-parameter model of TR-AFM resonator utilizing multiple time scales (MTS) method. Based on the developed analytical solution, the frequency-response curves of the resonator operation in air and liquid (for different penetration length of the nanoneedle) are obtained. The closed-form analytical solution and the frequency-response curves are validated by the comparison with both the finite element solution of the main partial differential equations and the experimental observations. The effect of excitation angle of the resonator on horizontal oscillation of the probe tip and the effect of different parameters on the frequency-response of the system are investigated.

  19. Fast solution of Cahn–Hilliard variational inequalities using implicit time discretization and finite elements

    KAUST Repository

    Bosch, Jessica

    2014-04-01

    We consider the efficient solution of the Cahn-Hilliard variational inequality using an implicit time discretization, which is formulated as an optimal control problem with pointwise constraints on the control. By applying a semi-smooth Newton method combined with a Moreau-Yosida regularization technique for handling the control constraints we show superlinear convergence in function space. At the heart of this method lies the solution of large and sparse linear systems for which we propose the use of preconditioned Krylov subspace solvers using an effective Schur complement approximation. Numerical results illustrate the competitiveness of this approach. © 2014 Elsevier Inc.

  20. Necessary and Sufficient Conditions for the Existence of Positive Solution for Singular Boundary Value Problems on Time Scales

    Directory of Open Access Journals (Sweden)

    Zhang Xuemei

    2009-01-01

    Full Text Available By constructing available upper and lower solutions and combining the Schauder's fixed point theorem with maximum principle, this paper establishes sufficient and necessary conditions to guarantee the existence of as well as positive solutions for a class of singular boundary value problems on time scales. The results significantly extend and improve many known results for both the continuous case and more general time scales. We illustrate our results by one example.

  1. Comparison between late-presenting and isolated neonatal congenital diaphragmatic hernias

    Directory of Open Access Journals (Sweden)

    Christos Plataras

    2011-01-01

    Full Text Available Purpose: Late-presenting posterolateral congenital diaphragmatic hernias (CDH are anatomically similar to isolated neonatal CDH but are diagnosed and treated after the first month of life. We aim to characterise the clinical manifestations and short-term postoperative course of this entity and compare it with isolated CDH of the neonatal period. Materials and Methods: In the 30-year period from 1980 to 2010, 116 children with CDH were treated at the Aghia Sophia Children′s Hospital, Athens, Greece. Twenty-three (19% of these children were late-presenting cases, being diagnosed between the ages of 1 month and 4 years. Ninety-three were neonatal cases, of whom 22 (24% were excluded due to severe associated anomalies, leaving 71 cases of isolated neonatal CDH. We compared these two groups of patients with regard to preoperative symptoms, postoperative hospital stay, time to complete feeding, overall complication rate, and reoperation rate. Results: Isolated neonatal cases presented more often with acute respiratory symptoms (n=25; P= 0.016 and failure to thrive (n= 38; P= 0.03. Late-presenting cases presented more often with chronic respiratory symptoms (n=14;P= 0.0044 or gastrointestinal symptoms (n=12; P= 0.006. Thirty-five cases with minor or serious complications were reported in the neonatal group, whereas only five complications were observed in the late-presenting group (P= 0.028. We did not record any recurrences or reoperations in the late-presenting group, but we had two recurrences and three reoperations in the neonatal group. Time to full feeds and postoperative hospital stay was shorter in the late-presenting group. Conclusions: Our data demonstrate differences between the two groups in preoperative symptoms and short-term postoperative complications and short-term outcome. Late-presenting cases of CDH had a greater number of chronic symptoms preoperatively, more favorable postoperative outcomes, and less recurrences and reoperations.

  2. The reliable solution and computation time of variable parameters logistic model

    Science.gov (United States)

    Wang, Pengfei; Pan, Xinnong

    2018-05-01

    The study investigates the reliable computation time (RCT, termed as T c) by applying a double-precision computation of a variable parameters logistic map (VPLM). Firstly, by using the proposed method, we obtain the reliable solutions for the logistic map. Secondly, we construct 10,000 samples of reliable experiments from a time-dependent non-stationary parameters VPLM and then calculate the mean T c. The results indicate that, for each different initial value, the T cs of the VPLM are generally different. However, the mean T c trends to a constant value when the sample number is large enough. The maximum, minimum, and probable distribution functions of T c are also obtained, which can help us to identify the robustness of applying a nonlinear time series theory to forecasting by using the VPLM output. In addition, the T c of the fixed parameter experiments of the logistic map is obtained, and the results suggest that this T c matches the theoretical formula-predicted value.

  3. TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS

    Science.gov (United States)

    2017-03-01

    AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS...DISTRIBUTION A. Approved for public release: distribution unlimited. Toxic Leadership: A Systemic Approach to Shift From Reactive to Proactive Solutions 1...US military loses valuable personnel when it is too late to implement corrective action and after those toxic Toxic Leadership: A Systemic Approach

  4. Speciation of actinides in aqueous solution by time-resolved laser-induced fluorescence spectroscopy (TRLFS)

    International Nuclear Information System (INIS)

    Kimura, Takaumi; Kato, Yoshiharu; Meinrath, G.; Yoshida, Zenko; Choppin, G.R.

    1995-01-01

    Time-resolved laser-induced fluorescence spectroscopy (TRLFS) as a sensitive and selective method has been applied to the speciation of actinides in aqueous solution. Studies on hydrolysis and carbonate complexation of U(VI) and on determination of hydration number of Cm(III) are reported. (author)

  5. Linear Scaling Solution of the Time-Dependent Self-Consistent-Field Equations

    Directory of Open Access Journals (Sweden)

    Matt Challacombe

    2014-03-01

    Full Text Available A new approach to solving the Time-Dependent Self-Consistent-Field equations is developed based on the double quotient formulation of Tsiper 2001 (J. Phys. B. Dual channel, quasi-independent non-linear optimization of these quotients is found to yield convergence rates approaching those of the best case (single channel Tamm-Dancoff approximation. This formulation is variational with respect to matrix truncation, admitting linear scaling solution of the matrix-eigenvalue problem, which is demonstrated for bulk excitons in the polyphenylene vinylene oligomer and the (4,3 carbon nanotube segment.

  6. The Ricci flow part IV : long-time solutions and related topics

    CERN Document Server

    Chow, Bennett; Glickenstein, David; Isenberg, James

    2015-01-01

    Ricci flow is a powerful technique using a heat-type equation to deform Riemannian metrics on manifolds to better metrics in the search for geometric decompositions. With the fourth part of their volume on techniques and applications of the theory, the authors discuss long-time solutions of the Ricci flow and related topics. In dimension 3, Perelman completed Hamilton's program to prove Thurston's geometrization conjecture. In higher dimensions the Ricci flow has remarkable properties, which indicates its usefulness to understand relations between the geometry and topology of manifolds. This b

  7. Pseudospectral operational matrix for numerical solution of single and multiterm time fractional diffusion equation

    OpenAIRE

    GHOLAMI, SAEID; BABOLIAN, ESMAIL; JAVIDI, MOHAMMAD

    2016-01-01

    This paper presents a new numerical approach to solve single and multiterm time fractional diffusion equations. In this work, the space dimension is discretized to the Gauss$-$Lobatto points. We use the normalized Grunwald approximation for the time dimension and a pseudospectral successive integration matrix for the space dimension. This approach shows that with fewer numbers of points, we can approximate the solution with more accuracy. Some examples with numerical results in tables and fig...

  8. Online Solution of Two-Player Zero-Sum Games for Continuous-Time Nonlinear Systems With Completely Unknown Dynamics.

    Science.gov (United States)

    Fu, Yue; Chai, Tianyou

    2016-12-01

    Regarding two-player zero-sum games of continuous-time nonlinear systems with completely unknown dynamics, this paper presents an online adaptive algorithm for learning the Nash equilibrium solution, i.e., the optimal policy pair. First, for known systems, the simultaneous policy updating algorithm (SPUA) is reviewed. A new analytical method to prove the convergence is presented. Then, based on the SPUA, without using a priori knowledge of any system dynamics, an online algorithm is proposed to simultaneously learn in real time either the minimal nonnegative solution of the Hamilton-Jacobi-Isaacs (HJI) equation or the generalized algebraic Riccati equation for linear systems as a special case, along with the optimal policy pair. The approximate solution to the HJI equation and the admissible policy pair is reexpressed by the approximation theorem. The unknown constants or weights of each are identified simultaneously by resorting to the recursive least square method. The convergence of the online algorithm to the optimal solutions is provided. A practical online algorithm is also developed. Simulation results illustrate the effectiveness of the proposed method.

  9. Late Pliocene Depositional History and Paleoclimate Reconstructions of the Southwest Pacific

    Science.gov (United States)

    Royce, B.; Patterson, M. O.; Pietras, J.

    2017-12-01

    Drift deposits off the eastern margin of New Zealand are important archives for the paleoclimate and paleoceanographic history of the southwest Pacific. Ocean Drilling Program (ODP) Site 1123 is located on the North Chatham rise drift just North of the westerly wind driven Subtropical Front (STF) and provides a record of near continuous sediment deposition since the Miocene along the southwest Pacific deep western boundary current (DWBC). While the Miocene and Late Pleistocene portion of this record have been well studied, the Late Pliocene record is less well developed. Southern Ocean geological records demonstrate that Late Pliocene cooling is the transient time bracketing the warmer than present Early Pliocene and bipolar glaciation at 2.7 Ma. A newly developed, robust, and astronomically tuned long-term record of benthic δ13C from ODP Site 1123 spanning the Early to Late Pliocene implies a reduction in Southern Ocean ventilation and lowering of preformed values from waters sourced along the Antarctic margin during the Late Pliocene. Thus, Late Pliocene Southern Hemisphere cooling and sea ice expansion may have drastically reduced outgassing and increased the burial of heat into the deep ocean. South Atlantic records off the west coast of Africa demonstrate an increase in the flux of iron to the open ocean during this time potentially enhancing surface ocean productivity and providing an additional cooling mechanism. Currently, atmospheric transport of dust to the Southern Ocean is dominated by persistent mid-latitude circumpolar westerly winds; this is particularly relevant for dust sourced from New Zealand. The Late Pliocene to Early Pleistocene uplift of the North Island axial ranges and South Island southern alps potentially provided a greater amount of not only sediment to the deep ocean, but also wind blow dust to the Pacific sector of the Southern Ocean. We will present a detailed high-resolution sedimentological study on the development of the Chatham

  10. On the internal resonant modes in marching-on-in-time solution of the time domain electric field integral equation

    KAUST Repository

    Shi, Yifei; Bagci, Hakan; Lu, Mingyu

    2013-01-01

    Internal resonant modes are always observed in the marching-on-in-time (MOT) solution of the time domain electric field integral equation (EFIE), although 'relaxed initial conditions,' which are enforced at the beginning of time marching, should in theory prevent these spurious modes from appearing. It has been conjectured that, numerical errors built up during time marching establish the necessary initial conditions and induce the internal resonant modes. However, this conjecture has never been proved by systematic numerical experiments. Our numerical results in this communication demonstrate that, the internal resonant modes' amplitudes are indeed dictated by the numerical errors. Additionally, it is shown that in a few cases, the internal resonant modes can be made 'invisible' by significantly suppressing the numerical errors. These tests prove the conjecture that the internal resonant modes are induced by numerical errors when the time domain EFIE is solved by the MOT method. © 2013 IEEE.

  11. On the internal resonant modes in marching-on-in-time solution of the time domain electric field integral equation

    KAUST Repository

    Shi, Yifei

    2013-08-01

    Internal resonant modes are always observed in the marching-on-in-time (MOT) solution of the time domain electric field integral equation (EFIE), although \\'relaxed initial conditions,\\' which are enforced at the beginning of time marching, should in theory prevent these spurious modes from appearing. It has been conjectured that, numerical errors built up during time marching establish the necessary initial conditions and induce the internal resonant modes. However, this conjecture has never been proved by systematic numerical experiments. Our numerical results in this communication demonstrate that, the internal resonant modes\\' amplitudes are indeed dictated by the numerical errors. Additionally, it is shown that in a few cases, the internal resonant modes can be made \\'invisible\\' by significantly suppressing the numerical errors. These tests prove the conjecture that the internal resonant modes are induced by numerical errors when the time domain EFIE is solved by the MOT method. © 2013 IEEE.

  12. Biogeography of late Silurian and devonian rugose corals

    Science.gov (United States)

    Oliver, W.A.

    1977-01-01

    Three marine benthic faunal realms can be recognized in the Early and Middle Devonian. The Eastern Americas Realm consisted of most of the eastern half of North America and South America north of the Amazon. This realm extended in a southwest direction from the Devonian equator to approximately 35??S and was an isolated epicontinental sea during much of its history. The Eastern Americas Realm was bounded on the west by the Transcontinental Arch, on the north by the Canadian Shield and on the east and southeast by a peninsular extension of the Old Red Continent. These barriers were emergent during much, but not all, of Devonian time. Seaways beyond these barriers belonged to the Old World Realm. The Malvinokaffric Realm that was farther south was apparently temperate to arctic in climate and latitudinal position and contained few corals. Rugose corals in the Eastern Americas Realm show increasing generic-level endemism from the Late Silurian through the Early Devonian; during the late Early Devonian, 92% of the rugosan genera are not known anywhere else in the world. Endemism decreased through the Middle Devonian to zero in the early Late Devonian. The Early Devonian increase in endemism paralleled, and was probably related to, the development of the Old Red Continent as a barrier between America and Africa-Europe. The waning of endemism in the Middle Devonian reflects the breaching of the land barriers. This permitted some migration in and out of the realm in early Middle Devonian time but greatest movements were in late Middle Devonian time. Principal migration directions were from western or Arctic North America into the Michigan-Hudson Bay area and from the southern Appalachian area into Africa. ?? 1977.

  13. Extraction of soil solution by drainage centrifugation-effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils.

    Science.gov (United States)

    Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique

    2017-02-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.

  14. Late time optical spectra from the /sup 56/Ni model for Type I supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, T.S.

    1980-07-01

    The hypothesis that the optical luminosity of Type I supernovae results from the radioactive decay of /sup 56/Ni synthesized and ejected by the explosion has been investigated by numerical simulation of the optical spectrum resulting from a homologously expanding shell composed initially of pure /sup 56/Ni core. This model, which neglects the effects of material external to the /sup 56/Ni core, is expected to provide a reasonable representation of the supernova at late times when the star is nearly transparent to optical photons. The numerical simulation determines the temperature, ionization state, and non-LTE level populations which result from energy deposition by the radioactive decay products of /sup 56/Ni and /sup 56/Co. The optical spectrum includes the effects of both allowed and forbidden lines. The optical spectra resulting from the simulation are found to be sensitive to the mass and ejection velocity of the /sup 56/Ni shell. A range of these parameters has been found which results in good agreement with the observed spectra of SN1972e over a considerable range of time. In particular, evidence for the expected decaying abundance of /sup 56/Co has been found in the spectra of SN1972e. These results are used to assess the validity of the /sup 56/Ni model and set limits on the mass and explosion mechanism of the Type I progenitor. The possibilities for improvement of the numerical model are discussed and future atomic data requirements defined.

  15. Informatics solutions for Three-dimensional visualization in real time

    International Nuclear Information System (INIS)

    Guzman Montoto, Jose Ignacio

    2002-01-01

    The advances reached in the development of the hardware and in the methods of acquisition of data like tomographic scanners and systems of analysis of images, have allowed obtaining geometric models of biomedical elements with the property of being manipulated through the three-dimensional visualization (3D). Nowadays, this visualization embraces from biological applications, including analysis of structures and its functional relationships, until medical applications that include anatomical accuracies and the planning or the training for complex surgical operations. This work proposes computer solutions to satisfy visualization requirements in real time. The developed algorithms are contained in a graphic library that will facilitate the development of future works. The obtained results allow facing current problems of three-dimensional representation of complex surfaces, realism is reached in the images and they have possible application in bioinformatics and medicine

  16. Lateness to School Remediation Game

    Science.gov (United States)

    Ugwuegbulam, Charles N.; Ibrahim, Haj. Naheed

    2015-01-01

    Primary and secondary school in Nigeria encourage punctuality to school yet a good number of the learners came late to school. This is especially true in the case of day students. Learners who come late to school are usually punished in one way or the other yet the lateness to school phenomenon still persist. Lateness to school behaviour affects…

  17. A comparison of numerical methods for the solution of continuous-time DSGE models

    DEFF Research Database (Denmark)

    Parra-Alvarez, Juan Carlos

    This paper evaluates the accuracy of a set of techniques that approximate the solution of continuous-time DSGE models. Using the neoclassical growth model I compare linear-quadratic, perturbation and projection methods. All techniques are applied to the HJB equation and the optimality conditions...... parameters of the model and suggest the use of projection methods when a high degree of accuracy is required....

  18. Differences in grip force control between young and late middle-aged adults.

    Science.gov (United States)

    Zheng, Lianrong; Li, Kunyang; Wang, Qian; Chen, Wenhui; Song, Rong; Liu, Guanzheng

    2017-09-01

    Grip force control is a crucial function for human to guarantee the quality of life. To examine the effects of age on grip force control, 10 young adults and 11 late middle-aged adults participated in visually guided tracking tasks using different target force levels (25, 50, and 75% of the subject's maximal grip force). Multiple measures were used to evaluate the tracking performance during force rising phase and force maintenance phase. The measurements include the rise time, fuzzy entropy, mean force percentage, coefficient of variation, and target deviation ratio. The results show that the maximal grip force was significantly lower in the late middle-aged adults than in the young adults. The time of rising phase was systematically longer among late middle-aged adults. The fuzzy entropy is a useful indicator for quantitating the force variability of the grip force signal at higher force levels. These results suggest that the late middle-aged adults applied a compensatory strategy that allow allows for sufficient time to reach the required grip force and reduce the impact of the early and subtle degenerative changes in hand motor function.

  19. Late-onset myasthenia not on the increase

    DEFF Research Database (Denmark)

    Pedersen, E G; Hallas, Jesper; Hansen, K

    2013-01-01

    BACKGROUND: An increase in late-onset myasthenia gravis (MG) has been reported. There are few large population-based studies over longer periods of time reflecting recent developments in MG incidence. METHODS: We identified a nationwide cohort of patients with incident myasthenia in Denmark in 1996...

  20. Self-Similar Nonlinear Dynamical Solutions for One-Component Nonneutral Plasma in a Time-Dependent Linear Focusing Field

    International Nuclear Information System (INIS)

    Qin, Hong; Davidson, Ronald C.

    2011-01-01

    In a linear trap confining a one-component nonneutral plasma, the external focusing force is a linear function of the configuration coordinates and/or the velocity coordinates. Linear traps include the classical Paul trap and the Penning trap, as well as the newly proposed rotating-radio- frequency traps and the Mobius accelerator. This paper describes a class of self-similar nonlinear solutions of nonneutral plasma in general time-dependent linear focusing devices, with self-consistent electrostatic field. This class of nonlinear solutions includes many known solutions as special cases.

  1. Similarity solutions of the Fokker–Planck equation with time-dependent coefficients

    International Nuclear Information System (INIS)

    Lin, W.-T.; Ho, C.-L.

    2012-01-01

    In this work, we consider the solvability of the Fokker–Planck equation with both time-dependent drift and diffusion coefficients by means of the similarity method. By the introduction of the similarity variable, the Fokker–Planck equation is reduced to an ordinary differential equation. Adopting the natural requirement that the probability current density vanishes at the boundary, the resulting ordinary differential equation turns out to be integrable, and the probability density function can be given in closed form. New examples of exactly solvable Fokker–Planck equations are presented, and their properties analyzed. - Highlights: ► Scaling form of the Fokker–Planck equation with time-dependent drift and diffusion coefficients is derived. ► Exact similarity solution of the Fokker–Planck equation is given in closed forms. ► New examples of Fokker–Planck equations exactly solvable by similarity methods are discussed.

  2. Late Malignant Transformation of a Vestibular Schwannoma without Association to NFII or Radiotherapy

    DEFF Research Database (Denmark)

    Bashir, Asma; Poulsgaard, Lars; Broholm, Helle

    Late malignant transformation of vestibular schwannoma (VS) following irradiation has previously been reported 29 times in the literature. Here, the authors report the first late malignant transformation of VS unrelated to neurofibromatosis or radiation exposure. After undergoing a near-total exc...

  3. Discharge time dependence of a solution plasma process for colloidal copper nanoparticle synthesis and particle characteristics

    International Nuclear Information System (INIS)

    Pootawang, Panuphong; Saito, Nagahiro; Lee, Sang Yul

    2013-01-01

    In this study, we investigate a new synthetic route, termed the solution plasma process, for the synthesis of colloidal copper nanoparticles (CuNPs) in the presence of an amide and acid capping agent. Gelatin and ascorbic acid were selected as the capping agents to protect the particles against coalescence and oxidation side reaction. Using a high voltage power supply, CuNPs were rapidly formed by 1 min after the discharge. The size and shape of the CuNPs were dependent on the discharge time and were clearly influenced by the effect of the capping agents under two characteristics of the discharge medium (pH and temperature). With a long discharge time, the CuNP size tended to decrease with the formation of anisotropic particle morphologies: spherical, cubic, hexagonal, triangular and rod-like shapes. The decrease in CuNP size as a function of discharge time could be explained by the dissolution of CuNPs in a lower pH solution. After 5 min discharge the capping agent evidently allowed the protection of the synthesized CuNPs against oxidation with the presence of anisotropic CuNP shapes. It is demonstrated that the CuNP shape could be tuned from spherical to anisotropic shapes without the undesirable oxidation by adjusting the discharge time of the solution plasma. These advantages are valuable for material engineering to design the properties of Cu-based nanoparticles for the desired applications. (paper)

  4. 7 CFR 920.112 - Late payments.

    Science.gov (United States)

    2010-01-01

    ... Miscellaneous Provisions § 920.112 Late payments. Pursuant to § 920.41(a), interest will be charged at a 1.5 percent monthly simple interest rate. Assessments for kiwifruit shall be deemed late if not received... late charge will be assessed when payment becomes 30 days late. Interest and late payment charges shall...

  5. A Cost-effectiveness Analysis of Early vs Late Tracheostomy.

    Science.gov (United States)

    Liu, C Carrie; Rudmik, Luke

    2016-10-01

    The timing of tracheostomy in critically ill patients requiring mechanical ventilation is controversial. An important consideration that is currently missing in the literature is an evaluation of the economic impact of an early tracheostomy strategy vs a late tracheostomy strategy. To evaluate the cost-effectiveness of the early tracheostomy strategy vs the late tracheostomy strategy. This economic analysis was performed using a decision tree model with a 90-day time horizon. The economic perspective was that of the US health care third-party payer. The primary outcome was the incremental cost per tracheostomy avoided. Probabilities were obtained from meta-analyses of randomized clinical trials. Costs were obtained from the published literature and the Healthcare Cost and Utilization Project database. A multivariate probabilistic sensitivity analysis was performed to account for uncertainty surrounding mean values used in the reference case. The reference case demonstrated that the cost of the late tracheostomy strategy was $45 943.81 for 0.36 of effectiveness. The cost of the early tracheostomy strategy was $31 979.12 for 0.19 of effectiveness. The incremental cost-effectiveness ratio for the late tracheostomy strategy compared with the early tracheostomy strategy was $82 145.24 per tracheostomy avoided. With a willingness-to-pay threshold of $50 000, the early tracheostomy strategy is cost-effective with 56% certainty. The adaptation of an early vs a late tracheostomy strategy depends on the priorities of the decision-maker. Up to a willingness-to-pay threshold of $80 000 per tracheostomy avoided, the early tracheostomy strategy has a higher probability of being the more cost-effective intervention.

  6. On positive periodic solution of periodic competition Lotka-Volterra system with time delay and diffusion

    International Nuclear Information System (INIS)

    Sun Wen; Chen Shihua; Hong Zhiming; Wang Changping

    2007-01-01

    A two-species periodic competition Lotka-Volterra system with time delay and diffusion is investigated. Some sufficient conditions of the existence of positive periodic solution are established for the system by using the continuation theorem of coincidence degree theory

  7. An Experimental Study on Solute Transport in One-Dimensional Clay Soil Columns

    Directory of Open Access Journals (Sweden)

    Muhammad Zaheer

    2017-01-01

    Full Text Available Solute transport in low-permeability media such as clay has not been studied carefully up to present, and we are often unclear what the proper governing law is for describing the transport process in such media. In this study, we composed and analyzed the breakthrough curve (BTC data and the development of leaching in one-dimensional solute transport experiments in low-permeability homogeneous and saturated media at small scale, to identify key parameters controlling the transport process. Sodium chloride (NaCl was chosen to be the tracer. A number of tracer tests were conducted to inspect the transport process under different conditions. The observed velocity-time behavior for different columns indicated the decline of soil permeability when switching from tracer introducing to tracer flushing. The modeling approaches considered were the Advection-Dispersion Equation (ADE, Two-Region Model (TRM, Continuous Time Random Walk (CTRW, and Fractional Advection-Dispersion Equation (FADE. It was found that all the models can fit the transport process very well; however, ADE and TRM were somewhat unable to characterize the transport behavior in leaching. The CTRW and FADE models were better in capturing the full evaluation of tracer-breakthrough curve and late-time tailing in leaching.

  8. Anisotropic cosmological solutions in massive vector theories

    Energy Technology Data Exchange (ETDEWEB)

    Heisenberg, Lavinia [Institute for Theoretical Studies, ETH Zurich, Clausiusstrasse 47, 8092 Zurich (Switzerland); Kase, Ryotaro; Tsujikawa, Shinji, E-mail: Lavinia.heisenberg@googlemail.com, E-mail: r.kase@rs.tus.ac.jp, E-mail: shinji@rs.kagu.tus.ac.jp [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

    2016-11-01

    In beyond-generalized Proca theories including the extension to theories higher than second order, we study the role of a spatial component v of a massive vector field on the anisotropic cosmological background. We show that, as in the case of the isotropic cosmological background, there is no additional ghostly degrees of freedom associated with the Ostrogradski instability. In second-order generalized Proca theories we find the existence of anisotropic solutions on which the ratio between the anisotropic expansion rate Σ and the isotropic expansion rate H remains nearly constant in the radiation-dominated epoch. In the regime where Σ/ H is constant, the spatial vector component v works as a dark radiation with the equation of state close to 1/3. During the matter era, the ratio Σ/ H decreases with the decrease of v . As long as the conditions |Σ| || H and v {sup 2} || φ{sup 2} are satisfied around the onset of late-time cosmic acceleration, where φ is the temporal vector component, we find that the solutions approach the isotropic de Sitter fixed point (Σ = 0 = v ) in accordance with the cosmic no-hair conjecture. In the presence of v and Σ the early evolution of the dark energy equation of state w {sub DE} in the radiation era is different from that in the isotropic case, but the approach to the isotropic value w {sub DE}{sup (iso)} typically occurs at redshifts z much larger than 1. Thus, apart from the existence of dark radiation, the anisotropic cosmological dynamics at low redshifts is similar to that in isotropic generalized Proca theories. In beyond-generalized Proca theories the only consistent solution to avoid the divergence of a determinant of the dynamical system corresponds to v = 0, so Σ always decreases in time.

  9. Anisotropic cosmological solutions in massive vector theories

    International Nuclear Information System (INIS)

    Heisenberg, Lavinia; Kase, Ryotaro; Tsujikawa, Shinji

    2016-01-01

    In beyond-generalized Proca theories including the extension to theories higher than second order, we study the role of a spatial component v of a massive vector field on the anisotropic cosmological background. We show that, as in the case of the isotropic cosmological background, there is no additional ghostly degrees of freedom associated with the Ostrogradski instability. In second-order generalized Proca theories we find the existence of anisotropic solutions on which the ratio between the anisotropic expansion rate Σ and the isotropic expansion rate H remains nearly constant in the radiation-dominated epoch. In the regime where Σ/ H is constant, the spatial vector component v works as a dark radiation with the equation of state close to 1/3. During the matter era, the ratio Σ/ H decreases with the decrease of v . As long as the conditions |Σ| || H and v 2 || φ 2 are satisfied around the onset of late-time cosmic acceleration, where φ is the temporal vector component, we find that the solutions approach the isotropic de Sitter fixed point (Σ = 0 = v ) in accordance with the cosmic no-hair conjecture. In the presence of v and Σ the early evolution of the dark energy equation of state w DE in the radiation era is different from that in the isotropic case, but the approach to the isotropic value w DE (iso) typically occurs at redshifts z much larger than 1. Thus, apart from the existence of dark radiation, the anisotropic cosmological dynamics at low redshifts is similar to that in isotropic generalized Proca theories. In beyond-generalized Proca theories the only consistent solution to avoid the divergence of a determinant of the dynamical system corresponds to v = 0, so Σ always decreases in time.

  10. Robotic 4D ultrasound solution for real-time visualization and teleoperation

    Directory of Open Access Journals (Sweden)

    Al-Badri Mohammed

    2017-09-01

    Full Text Available Automation of the image acquisition process via robotic solutions offer a large leap towards resolving ultrasound’s user-dependency. This paper, as part of a larger project aimed to develop a multipurpose 4d-ultrasonic force-sensitive robot for medical applications, focuses on achieving real-time remote visualisation for 4d ultrasound image transfer. This was possible through implementing our software modification on a GE Vivid 7 Dimension workstation, which operates a matrix array probe controlled by a KUKA LBR iiwa 7 7-DOF robotic arm. With the help of robotic positioning and the matrix array probe, fast volumetric imaging of target regions was feasible. By testing ultrasound volumes, which were roughly 880 kB in size, while using gigabit Ethernet connection, a latency of ∼57 ms was achievable for volume transfer between the ultrasound station and a remote client application, which as a result allows a frame count of 17.4 fps. Our modification thus offers for the first time real-time remote visualization, recording and control of 4d ultrasound data, which can be implemented in teleoperation.

  11. Time-resolved interaction investigations of carbocyanine dyes and chlorophyll a in solution

    International Nuclear Information System (INIS)

    Feller, K.H.; Fassler, D.

    1983-01-01

    Using a Nd:YAG laser/streak camera system of 30 ps time resolution the quenching of the fluorescence of the carbocyanine dye ICC by chlorophyll a in methanolic solution was investigated. The fluorescence lifetime of ICC decreased within the chlorophyll concentration range 0 - 9x10 - 5 mol/l from 170 ps to 135 ps. The observed very effective fluorescence quenching process suggests that the formation of heteroaggregates from ICC and chlorophyll is responsible for the rapid energy transfer. (author)

  12. Late effects of normal tissues (lent) scoring system: the soma scale

    International Nuclear Information System (INIS)

    Mornex, F.; Pavy, J.J.; Denekamp, J.

    1997-01-01

    Radiation tolerance of normal tissues remains the limiting factor for delivering tumoricidal dose. The late toxicity of normal tissues is the most critical element of an irradiation: somatic, functional and structural alterations occur during the actual treatment itself, but late effects manifest months to years after acute effects heal, and may progress with time. The optimal therapeutic ratio ultimately requires not only complete tumor clearance, but also minimal residual injury to surrounding vital normal tissues. The disparity between the intensity of acute and late effects and the inability to predict the eventual manifestation of late normal tissue injury has made radiation oncologists recognize the importance of careful patient follow-up. There is so far no uniform toxicity scoring system to compare several clinical studies in the absence of a 'common toxicity language'. This justifies the need to establish a precise evaluation system for the analysis of late effects of radiation on normal tissues. The SOMA/LENT scoring system results from an international collaboration. European Organization Treatment of Cancer (EORTC) and Radiation Therapy Oncology Group (RTOG) have created subcommittees with the aim of addressing the question of standardized toxic effects criteria. This effort appeared as a necessity to standardize and improve the data recording, to then describe and evaluate uniform toxicity at regular time intervals. The current proposed scale is not yet validated, and should be used cautiously. (authors)

  13. A "package solution" fast track program can reduce the diagnostic waiting time in head and neck cancer

    DEFF Research Database (Denmark)

    Sørensen, Jesper Roed; Johansen, Jørgen; Gano, Lars

    2014-01-01

    and Neck Surgery during three comparable time intervals 2006-2007, 2007-2008, and 2011-2012 (groups 1-3) were investigated. We recorded the time from patient referral, to first consultation and final diagnosis. The first interval was before initiation of the "package solution", the second just after......In 2007, a fast track program for patients with suspicion of head and neck cancer (HNC) was introduced in Denmark to reduce unnecessary waiting time. The program was based on so called "package solutions" including pre-booked slots for outpatient evaluation, imaging, and diagnostic surgical...... procedures. The purpose of this study is to present a model for fast track handling of patients suspicious of cancer in the head and neck region and to evaluate the effect of implementation on the diagnostic work up time. Patients with suspicion of HNC referred to the same university department of ENT Head...

  14. Late radiation injury to muscle and peripheral nerves

    International Nuclear Information System (INIS)

    Gillette, E. L.; Mahler, P. A.; Powers, B. E.; Gillette, S. M.; Vujaskovic, Z.

    1995-01-01

    Late radiation injury to muscles and peripheral nerves is infrequently observed. However, the success of radiation oncology has led to longer patient survival, providing a greater opportunity for late effects to develop, increase in severity and, possibly, impact the quality of life of the patient. In addition, when radiation therapy is combined with surgery and/or chemotherapy, the risk of late complications is likely to increase. It is clear that the incidence of complications involving muscles and nerves increases with time following radiation. The influence of volume has yet to be determined; however, an increased volume is likely to increase the risk of injury to muscles and nerves. Experimental and clinical studies have indicated that the (α(β)) ratio for muscle is approximately 4 Gy and, possibly, 2 Gy for peripheral nerve, indicating the great influence of fractionation on response of these tissues. This is of concern for intraoperative radiation therapy, and for high dose rate brachytherapy. This review of clinical and experimental data discusses the response of muscle and nerves late after radiation therapy. A grading system has been proposed and endpoints suggested

  15. Determinants and prevalence of late HIV testing in Tijuana, Mexico.

    Science.gov (United States)

    Carrizosa, Claudia M; Blumberg, Elaine J; Hovell, Melbourne F; Martinez-Donate, Ana P; Garcia-Gonzalez, Gregorio; Lozada, Remedios; Kelley, Norma J; Hofstetter, C Richard; Sipan, Carol L

    2010-05-01

    Timely diagnosis of HIV is essential to improve survival rates and reduce transmission of the virus. Insufficient progress has been made in effecting earlier HIV diagnoses. The Mexican border city of Tijuana has one of the highest AIDS incidence and mortality rates in all of Mexico. This study examined the prevalence and potential correlates of late HIV testing in Tijuana, Mexico. Late testers were defined as participants who had at least one of: (1) an AIDS-defining illness within 1 year of first positive HIV test; (2) a date of AIDS diagnosis within 1 year of first positive HIV test; or (3) an initial CD4 cell count below 200 cells per microliter within 1 year of first positive HIV test. Medical charts of 670 HIV-positive patients from two HIV/AIDS public clinics in Tijuana were reviewed and abstracted; 362 of these patients were interviewed using a cross-sectional survey. Using multivariate logistic regression, we explored potential correlates of late HIV testing based on the Behavioral Ecological Model. From 342 participants for whom late testing could be determined, the prevalence of late testing was 43.2%. Multivariate logistic regression results (n = 275) revealed five significant correlates of late testing: "I preferred not to know I had HIV" (adjusted odds ratio [AOR] = 2.78, 1.46-5.31); clinic (AOR = 1.90, 1.06-3.41); exposure to peers engaging in high-risk sexual behavior (AOR = 1.14, 1.02-1.27); stigma regarding HIV-infected individuals (AOR = 0.65, 0.47-0.92); and stigma regarding HIV testing (AOR = 0.66, 0.45-0.97). These findings may inform the design of interventions to increase timely HIV testing and help reduce HIV transmission in the community at large.

  16. Analytic Solutions and Resonant Solutions of Hyperbolic Partial Differential Equations

    Science.gov (United States)

    Wagenmaker, Timothy Roger

    This dissertation contains two main subject areas. The first deals with solutions to the wave equation Du/Dt + a Du/Dx = 0, where D/Dt and D/Dx represent partial derivatives and a(t,x) is real valued. The question I studied, which arises in control theory, is whether solutions which are real analytic with respect to the time variable are dense in the space of all solutions. If a is real analytic in t and x, the Cauchy-Kovalevsky Theorem implies that the solutions real analytic in t and x are dense, since it suffices to approximate the initial data by polynomials. The same positive result is valid when a is continuously differentiable and independent of t. This is proved by regularization in time. The hypothesis that a is independent of t cannot be replaced by the weaker assumption that a is real analytic in t, even when it is infinitely smooth. I construct a(t,x) for which the solutions which are analytic in time are automatically periodic in time. In particular these solutions are not dense in the space of all solutions. The second area concerns the resonant interaction of oscillatory waves propagating in a compressible inviscid fluid. An asymptotic description given by Andrew Majda, Rodolfo Rosales, and Maria Schonbek (MRS) involves the genuinely nonlinear quasilinear hyperbolic system Du/Dt + D(uu/2)/Dt + v = 0, Dv/Dt - D(vv/2)/Dt - u = 0. They performed many numerical simulations which indicated that small amplitude solutions of this system tend to evade shock formation, and conjectured that "smooth initial data with a sufficiently small amplitude never develop shocks throughout a long time interval of integration.". I proved that for smooth periodic U(x), V(x) and initial data u(0,x) = epsilonU(x), v(0,x) = epsilonV(x), the solution is smooth for time at least constant times | ln epsilon| /epsilon. This is longer than the lifetime order 1/ epsilon of the solution to the decoupled Burgers equations. The decoupled equation describes nonresonant interaction of

  17. Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint

    Science.gov (United States)

    Zou, Yang; Li, Jianchun; Laloui, Lyesse; Zhao, Jian

    2017-10-01

    The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived based on Maxwell and Kelvin models which are, respectively, applied to describe the viscoelastic deformational behaviour of the rock joint and incorporated into the displacement discontinuity model (DDM). The proposed solutions are verified by comparing with the previous studies on harmonic waves, which are simulated by sinusoidal incident P- and S-waves. Comparison between the predicted transmitted waves and the experimental data for P-wave propagation across a joint filled with clay is conducted. The Maxwell is found to be more appropriate to describe the filled joint. The parametric studies show that wave propagation is affected by many factors, such as the stiffness and the viscosity of joints, the incident angle and the duration of incident waves. Furthermore, the dependences of the transmission and reflection coefficients on the specific joint stiffness and viscosity are different for the joints with Maxwell and Kelvin behaviours. The alternation of the reflected and transmitted waveforms is discussed, and the application scope of this study is demonstrated by an illustration of the effects of the joint thickness. The solutions are also extended for multiple parallel joints with the virtual wave source method and the time-domain recursive method. For an incident wave with arbitrary waveform, it is convenient to adopt the present approach to directly calculate wave propagation across a viscoelastic rock joint without additional mathematical methods such as the Fourier and inverse Fourier transforms.

  18. Necessary and Sufficient Conditions for the Existence of Positive Solution for Singular Boundary Value Problems on Time Scales

    Directory of Open Access Journals (Sweden)

    Meiqiang Feng

    2009-01-01

    Full Text Available By constructing available upper and lower solutions and combining the Schauder's fixed point theorem with maximum principle, this paper establishes sufficient and necessary conditions to guarantee the existence of Cld[0,1]𝕋 as well as CldΔ[0,1]𝕋 positive solutions for a class of singular boundary value problems on time scales. The results significantly extend and improve many known results for both the continuous case and more general time scales. We illustrate our results by one example.

  19. Noether symmetries of a modified model in teleparallel gravity and a new approach for exact solutions

    Energy Technology Data Exchange (ETDEWEB)

    Tajahmad, Behzad [University of Tabriz, Faculty of Physics, Tabriz (Iran, Islamic Republic of)

    2017-04-15

    In this paper, we present the Noether symmetries of flat FRW spacetime in the context of a new action in teleparallel gravity which we construct based on the f(R) version. This modified action contains a coupling between the scalar field potential and magnetism. Also, we introduce an innovative approach, the beyond Noether symmetry (B.N.S.) approach, for exact solutions which carry more conserved currents than the Noether approach. By data analysis of the exact solutions, obtained from the Noether approach, late-time acceleration and phase crossing are realized, and some deep connections with observational data such as the age of the universe, the present value of the scale factor as well as the state and deceleration parameters are observed. In the B.N.S. approach, we consider the dark energy dominated era. (orig.)

  20. Noether symmetries of a modified model in teleparallel gravity and a new approach for exact solutions

    International Nuclear Information System (INIS)

    Tajahmad, Behzad

    2017-01-01

    In this paper, we present the Noether symmetries of flat FRW spacetime in the context of a new action in teleparallel gravity which we construct based on the f(R) version. This modified action contains a coupling between the scalar field potential and magnetism. Also, we introduce an innovative approach, the beyond Noether symmetry (B.N.S.) approach, for exact solutions which carry more conserved currents than the Noether approach. By data analysis of the exact solutions, obtained from the Noether approach, late-time acceleration and phase crossing are realized, and some deep connections with observational data such as the age of the universe, the present value of the scale factor as well as the state and deceleration parameters are observed. In the B.N.S. approach, we consider the dark energy dominated era. (orig.)

  1. Does Late-onset Anorexia Nervosa Exist? Findings From a Comparative Study in Singapore.

    Science.gov (United States)

    Tan, Shian Ming; Kwok, Kah Foo Victor; Zainal, Kelly A; Lee, Huei Yen

    2018-03-01

    The incidence of cases of older onset anorexia nervosa (AN) has increased in recent years. However, the literature on late-onset AN has been inconclusive. The goal of this study was to compare late-onset with early-onset cases of AN. Cases of AN presenting to an eating disorders treatment service were identified and the associated medical records were studied retrospectively. Of the 577 cases of AN that were studied, 7.1% were late-onset. Unlike the early-onset cases of AN, the late-onset cases reported less teasing and more relationship problems as a trigger for the illness. They were also less likely to join the eating disorders treatment program. Otherwise, the late-onset AN cases were largely similar to the early-onset cases. Although differences exist between early-onset and late-onset cases of AN, these are few. Until stronger evidence emerges over time, there currently seems to be minimal justification to accord late-onset AN a unique position in psychiatric nosology.

  2. Spike solutions in Gierer#x2013;Meinhardt model with a time dependent anomaly exponent

    Science.gov (United States)

    Nec, Yana

    2018-01-01

    Experimental evidence of complex dispersion regimes in natural systems, where the growth of the mean square displacement in time cannot be characterised by a single power, has been accruing for the past two decades. In such processes the exponent γ(t) in ⟨r2⟩ ∼ tγ(t) at times might be approximated by a piecewise constant function, or it can be a continuous function. Variable order differential equations are an emerging mathematical tool with a strong potential to model these systems. However, variable order differential equations are not tractable by the classic differential equations theory. This contribution illustrates how a classic method can be adapted to gain insight into a system of this type. Herein a variable order Gierer-Meinhardt model is posed, a generic reaction- diffusion system of a chemical origin. With a fixed order this system possesses a solution in the form of a constellation of arbitrarily situated localised pulses, when the components' diffusivity ratio is asymptotically small. The pattern was shown to exist subject to multiple step-like transitions between normal diffusion and sub-diffusion, as well as between distinct sub-diffusive regimes. The analytical approximation obtained permits qualitative analysis of the impact thereof. Numerical solution for typical cross-over scenarios revealed such features as earlier equilibration and non-monotonic excursions before attainment of equilibrium. The method is general and allows for an approximate numerical solution with any reasonably behaved γ(t).

  3. Large Time Behavior for Weak Solutions of the 3D Globally Modified Navier-Stokes Equations

    Directory of Open Access Journals (Sweden)

    Junbai Ren

    2014-01-01

    Full Text Available This paper is concerned with the large time behavior of the weak solutions for three-dimensional globally modified Navier-Stokes equations. With the aid of energy methods and auxiliary decay estimates together with Lp-Lq estimates of heat semigroup, we derive the optimal upper and lower decay estimates of the weak solutions for the globally modified Navier-Stokes equations as C1(1+t-3/4≤uL2≤C2(1+t-3/4,  t>1. The decay rate is optimal since it coincides with that of heat equation.

  4. Late Sleeping Affects Sleep Duration and Body Mass Index in Adolescents

    Directory of Open Access Journals (Sweden)

    Rajesh G.Kathrotia1,

    2010-03-01

    Full Text Available During adolescence, there is a tendency to sleep late andsleep less because of altered psychosocial and life-stylechanges. Recent studies have demonstrated the link betweensleeping less and gaining weight in children, adolescents, andadults. We studied the effect of late sleeping and sleepingless on body mass index (BMI in medical college freshmen.All participants were adolescents (104 male and 38 femaleadolescents, mean age 17.77±0.79 years. After obtaininginformed consent, they filled out a questionnaire about theirsleeping habits. Height and weight were measured after abrief history taking and clinical examination. BMI increasedsignificantly with decrease in total sleep duration and withdelayed bedtime. Late sleeping individuals (after midnighthad significantly less sleep duration (6.78 hours v 7.74 hours,P<0.001, more day time sleepiness (85.2% v 69.3%,P=0.033 and more gap between dinner time and going tosleep (234.16 min v 155.45 min, P<0.001. Increased BMI inlate sleepers may be explained by low physical activity duringthe day caused by excess sleepiness and increased calorieintake with a gap of 5-6 hours between dinner and sleep.Sleep habits of late sleeping and sleeping less contribute toincrease BMI in adolescents.

  5. Stability of Almost Periodic Solution for a General Class of Discontinuous Neural Networks with Mixed Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Yingwei Li

    2013-01-01

    Full Text Available The global exponential stability issues are considered for almost periodic solution of the neural networks with mixed time-varying delays and discontinuous neuron activations. Some sufficient conditions for the existence, uniqueness, and global exponential stability of almost periodic solution are achieved in terms of certain linear matrix inequalities (LMIs, by applying differential inclusions theory, matrix inequality analysis technique, and generalized Lyapunov functional approach. In addition, the existence and asymptotically almost periodic behavior of the solution of the neural networks are also investigated under the framework of the solution in the sense of Filippov. Two simulation examples are given to illustrate the validity of the theoretical results.

  6. A knowledge-based system framework for real-time monitoring applications

    International Nuclear Information System (INIS)

    Heaberlin, J.O.; Robinson, A.H.

    1989-01-01

    A real-time environment presents a challenge for knowledge-based systems for process monitoring with on-line data acquisition in nuclear power plants. These applications are typically data intensive. This, coupled with the dynamic nature of events on which problematic decisions are based, requires the development of techniques fundamentally different from those generally employed. Traditional approaches involve knowledge management techniques developed for static data, the majority of which is elicited directly from the user in a consultation environment. Inference mechanisms are generally noninterruptible, requiring all appropriate rules to be fired before new data can be accommodated. As a result, traditional knowledge-based applications in real-time environments have inherent problems in dealing with the time dependence of both the data and the solution process. For example, potential problems include obtaining a correct solution too late to be of use or focusing computing resources on problems that no longer exist. A knowledge-based system framework, the real-time framework (RTF), has been developed that can accommodate the time dependencies and resource trade-offs required for real-time process monitoring applications. This framework provides real-time functionality by using generalized problem-solving goals and control strategies that are modifiable during system operation and capable of accommodating feedback for redirection of activities

  7. The association of sleep and late-night cell phone use among adolescents

    Directory of Open Access Journals (Sweden)

    Babak Amra

    Full Text Available Abstract Objective: This study aims to assess the relationship of late-night cell phone use with sleep duration and quality in a sample of Iranian adolescents. Methods: The study population consisted of 2400 adolescents, aged 12-18 years, living in Isfahan, Iran. Age, body mass index, sleep duration, cell phone use after 9 p.m., and physical activity were documented. For sleep assessment, the Pittsburgh Sleep Quality Index questionnaire was used. Results: The participation rate was 90.4% (n = 2257 adolescents. The mean (SD age of participants was 15.44 (1.55 years; 1270 participants reported to use cell phone after 9 p.m. Overall, 56.1% of girls and 38.9% of boys reported poor quality sleep, respectively. Wake-up time was 8:17 a.m. (2.33, among late-night cell phone users and 8:03 a.m. (2.11 among non-users. Most (52% late-night cell phone users had poor sleep quality. Sedentary participants had higher sleep latency than their peers. Adjusted binary and multinomial logistic regression models showed that late-night cell users were 1.39 times more likely to have a poor sleep quality than non-users (p-value < 0.001. Conclusion: Late-night cell phone use by adolescents was associated with poorer sleep quality. Participants who were physically active had better sleep quality and quantity. As part of healthy lifestyle recommendations, avoidance of late-night cell phone use should be encouraged in adolescents.

  8. The association of sleep and late-night cell phone use among adolescents.

    Science.gov (United States)

    Amra, Babak; Shahsavari, Ali; Shayan-Moghadam, Ramin; Mirheli, Omid; Moradi-Khaniabadi, Bita; Bazukar, Mehdi; Yadollahi-Farsani, Ashkan; Kelishadi, Roya

    This study aims to assess the relationship of late-night cell phone use with sleep duration and quality in a sample of Iranian adolescents. The study population consisted of 2400 adolescents, aged 12-18 years, living in Isfahan, Iran. Age, body mass index, sleep duration, cell phone use after 9p.m., and physical activity were documented. For sleep assessment, the Pittsburgh Sleep Quality Index questionnaire was used. The participation rate was 90.4% (n=2257 adolescents). The mean (SD) age of participants was 15.44 (1.55) years; 1270 participants reported to use cell phone after 9p.m. Overall, 56.1% of girls and 38.9% of boys reported poor quality sleep, respectively. Wake-up time was 8:17 a.m. (2.33), among late-night cell phone users and 8:03a.m. (2.11) among non-users. Most (52%) late-night cell phone users had poor sleep quality. Sedentary participants had higher sleep latency than their peers. Adjusted binary and multinomial logistic regression models showed that late-night cell users were 1.39 times more likely to have a poor sleep quality than non-users (p-value<0.001). Late-night cell phone use by adolescents was associated with poorer sleep quality. Participants who were physically active had better sleep quality and quantity. As part of healthy lifestyle recommendations, avoidance of late-night cell phone use should be encouraged in adolescents. Copyright © 2017. Published by Elsevier Editora Ltda.

  9. Late Frasnian-Famennian climates based on palynomorph analyses and the question of the Late Devonian glaciations

    Science.gov (United States)

    Streel, Maurice; Caputo, Mário V.; Loboziak, Stanislas; Melo, José Henrique G.

    2000-11-01

    Palynomorph distribution in Euramerica and western Gondwana, from the Latest Givetian to the Latest Famennian, may be explained, to some extent, by climatic changes. Detailed miospore stratigraphy dates accurately the successive steps of these changes. Interpretation is built on three postulates which are discussed: Euramerica at slightly lower latitudes than generally accepted by most paleomagnetic reconstructions; a conodont time-scale accepted as the most used available subdivision of time; and Late Devonian sea-level fluctuations mainly governed by glacio-eustasy. The Frasnian-Famennian timescale is also evaluated. The comparison, based on conodont correlations, between Givetian and most of the Frasnian miospore assemblages from, respectively, northern and southern Euramerica demonstrates a high taxonomic diversity in the equatorial belt and much difference between supposed equatorial and (sub) tropical vegetations. On the contrary, a similar vegetation pattern and therefore probably compatible climatic conditions were present from tropical to subpolar areas. A rather hot climate culminated during the Latest Frasnian when equatorial miospore assemblages reached their maximum width. The miospore diversity shows also a rather clear global Late Frasnian minimum which is also recorded during the Early and Middle Famennian but only in low latitude regions while, in high latitude, very cold climates without perennial snow may explain the scarcity of miospores and so, of vegetation. The Early and Middle Famennian conspicuous latitudinal gradient of the vegetation seems to attenuate towards the Late and Latest Famennian but this might be above all the result of the development, of cosmopolitan coastal lowland vegetations (downstream swamps) depending more on the moisture and equable local microclimates than on the probably adverse climates of distant hinterland areas. During that time, periods of cold climate without perennial snow cover and with rare vegetation may

  10. Global paths of time-periodic solutions of the Benjamin-Ono equation connecting arbitrary traveling waves

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, David M.; Wilkening, Jon

    2008-12-11

    We classify all bifurcations from traveling waves to non-trivial time-periodic solutions of the Benjamin-Ono equation that are predicted by linearization. We use a spectrally accurate numerical continuation method to study several paths of non-trivial solutions beyond the realm of linear theory. These paths are found to either re-connect with a different traveling wave or to blow up. In the latter case, as the bifurcation parameter approaches a critical value, the amplitude of the initial condition grows without bound and the period approaches zero. We propose a conjecture that gives the mapping from one bifurcation to its counterpart on the other side of the path of non-trivial solutions. By experimentation with data fitting, we identify the form of the exact solutions on the path connecting two traveling waves, which represents the Fourier coefficients of the solution as power sums of a finite number of particle positions whose elementary symmetric functions execute simple orbits in the complex plane (circles or epicycles). We then solve a system of algebraic equations to express the unknown constants in the new representation in terms of the mean, a spatial phase, a temporal phase, four integers (enumerating the bifurcation at each end of the path) and one additional bifurcation parameter. We also find examples of interior bifurcations from these paths of already non-trivial solutions, but we do not attempt to analyze their algebraic structure.

  11. Exact analytical solution of time-independent neutron transport equation, and its applications to systems with a point source

    International Nuclear Information System (INIS)

    Mikata, Y.

    2014-01-01

    Highlights: • An exact solution for the one-speed neutron transport equation is obtained. • This solution as well as its derivation are believed to be new. • Neutron flux for a purely absorbing material with a point neutron source off the origin is obtained. • Spherically as well as cylindrically piecewise constant cross sections are studied. • Neutron flux expressions for a point neutron source off the origin are believed to be new. - Abstract: An exact analytical solution of the time-independent monoenergetic neutron transport equation is obtained in this paper. The solution is applied to systems with a point source. Systematic analysis of the solution of the time-independent neutron transport equation, and its applications represent the primary goal of this paper. To the best of the author’s knowledge, certain key results on the scalar neutron flux as well as their derivations are new. As an application of these results, a scalar neutron flux for a purely absorbing medium with a spherically piecewise constant cross section and an isotropic point neutron source off the origin as well as that for a cylindrically piecewise constant cross section with a point neutron source off the origin are obtained. Both of these results are believed to be new

  12. Bouncing cosmological solutions from f(R,T) gravity

    Science.gov (United States)

    Shabani, Hamid; Ziaie, Amir Hadi

    2018-05-01

    In this work we study classical bouncing solutions in the context of f(R,T)=R+h(T) gravity in a flat FLRW background using a perfect fluid as the only matter content. Our investigation is based on introducing an effective fluid through defining effective energy density and pressure; we call this reformulation as the " effective picture". These definitions have been already introduced to study the energy conditions in f(R,T) gravity. We examine various models to which different effective equations of state, corresponding to different h(T) functions, can be attributed. It is also discussed that one can link between an assumed f(R,T) model in the effective picture and the theories with generalized equation of state ( EoS). We obtain cosmological scenarios exhibiting a nonsingular bounce before and after which the Universe lives within a de-Sitter phase. We then proceed to find general solutions for matter bounce and investigate their properties. We show that the properties of bouncing solution in the effective picture of f(R,T) gravity are as follows: for a specific form of the f(R,T) function, these solutions are without any future singularities. Moreover, stability analysis of the nonsingular solutions through matter density perturbations revealed that except two of the models, the parameters of scalar-type perturbations for the other ones have a slight transient fluctuation around the bounce point and damp to zero or a finite value at late times. Hence these bouncing solutions are stable against scalar-type perturbations. It is possible that all energy conditions be respected by the real perfect fluid, however, the null and the strong energy conditions can be violated by the effective fluid near the bounce event. These solutions always correspond to a maximum in the real matter energy density and a vanishing minimum in the effective density. The effective pressure varies between negative values and may show either a minimum or a maximum.

  13. Existence of positive solutions for semipositone dynamic system on time scales

    Directory of Open Access Journals (Sweden)

    You-Wei Zhang

    2008-08-01

    Full Text Available In this paper, we study the following semipositone dynamic system on time scales $$displaylines{ -x^{DeltaDelta}(t=f(t,y+p(t, quad tin(0,T_{mathbb{T}},cr -y^{DeltaDelta}(t=g(t,x, quad tin(0,T_{mathbb{T}},cr x(0=x(sigma^{2}(T=0, cr alpha{y(0}-eta{y^{Delta}{(0}}= gamma{y(sigma(T}+delta{y^{Delta}(sigma(T}=0. }$$ Using fixed point index theory, we show the existence of at least one positive solution. The interesting point is the that nonlinear term is allowed to change sign and may tend to negative infinity.

  14. Langevin synchronization in a time-dependent, harmonic basin: An exact solution in 1D

    Science.gov (United States)

    Cadilhe, A.; Voter, Arthur F.

    2018-02-01

    The trajectories of two particles undergoing Langevin dynamics while sharing a common noise sequence can merge into a single (master) trajectory. Here, we present an exact solution for a particle undergoing Langevin dynamics in a harmonic, time-dependent potential, thus extending the idea of synchronization to nonequilibrium systems. We calculate the synchronization level, i.e., the mismatch between two trajectories sharing a common noise sequence, in the underdamped, critically damped, and overdamped regimes. Finally, we provide asymptotic expansions in various limiting cases and compare to the time independent case.

  15. Prolonged naproxen joint residence time after intra-articular injection of lipophilic solutions comprising a naproxen glycolamide ester prodrug in the rat

    DEFF Research Database (Denmark)

    Thing, Mette; Lu, Yi; Agårdh, Li

    2013-01-01

    time. Two oils, medium-chain triglycerides and castor oil, differing with respect to viscosity were tested. After intra-articular administration of oil prodrug solutions, a significant increase in the time to maximum naproxen serum concentration from around 40 to 245min, an increase in the MRTj from......Intra-articular injection of oil solutions of lipophilic prodrugs that rapidly degrade to their parent compound in synovial fluid may constitute a feasible approach to increase the joint residence time of non-steroidal anti-inflammatory drugs. In this in vivo study, oil solutions of the N......,N-diethyl glycolamide ester prodrug of naproxen (16mg/ml) were injected into the rat knee joint by dosing 6μl formulation per 100g body weight. The sustained release properties were compared to those of intra-articularly injected aqueous and oil solutions of naproxen by monitoring the naproxen serum concentrations over...

  16. The late Cainozoic East Antarctic ice sheet

    International Nuclear Information System (INIS)

    Colhoun, E.A.

    1999-01-01

    A review, mainly of East Antarctic late Cainozoic (post 40 Ma) geological and geomorphological evidence, supports the hypothesis of the continuous presence of an ice sheet, of about the present size, since the late Miocene. Evidence is presented and the view advanced that, during the late Wisconsin maximum of isotope stage 2, ice was not nearly as thick or extensive over the continental shelf as required by the model of 'maximum' Antarctic glaciation. Some of the factors influencing the contribution of Antarctica to post-glacial sea-level rise are discussed. It is considered that Antarctica's contribution was probably considerably less than previously estimated. The dating of marine and freshwater sequences in the Vestfold and Bunger Hills is consistent with deglaciation around the Pleistocene Holocene boundary, after the Late Wisconsin maximum. A date of ∼25 ka BP from permafrost in the Larsemann Hills means that either the Larsemann Hills were not glaciated during the Late Wisconsin or the ice failed to erode much of the permafrost surface. The degree of weathering of rock and glacial drifts in the Vestfold, Larsemann and Bunger Hills suggests a long time for formation, perhaps considerably longer than indicated by the dated marine and freshwater sediment sequences. Cosmogenic isotope dating in the Vestfold Hills has provided equivocal ages for deglaciation. While the results could indicate deglaciation before 80 ka BP, they do not confirm such early deglaciation. If the ice cover was thin and failed to remove the previous rock exposure profile, then the assays could predate the last ice advance. Weathered iron crust fragments in the till suggest little erosion. The raised beaches of the oases are Holocene. Assuming they have been produced by post Late Wisconsin isostatic uplift and by the Holocene transgression, calculations show that the Antarctic continental ice sheet could not have been more than ∼500 m thicker in the inner shelf-coastal zone. The

  17. Relationship between acute and late normal tissue injury after postoperative radiotherapy in endometrial cancer

    International Nuclear Information System (INIS)

    Jereczek-Fossa, Barbara A.; Jassem, Jacek; Badzio, Andrzej

    2002-01-01

    Purpose: To evaluate the relationship between acute and late normal tissue reactions in 317 consecutive endometrial cancer patients treated with surgery and adjuvant radiotherapy (RT). Methods: The data of 317 patients (staging according to the International Federation of Gynecology and Obstetrics) treated with postoperative RT were analyzed. Both low-dose-rate brachytherapy and external beam RT were applied in 247 patients (78%); brachytherapy only in 49 (15%) and external beam irradiation only in 21 (7%). The median follow-up was 7.3 years (range 4-21). The European Organization for Research and Treatment of Cancer, Radiation Therapy Oncology Group system with elements of the late effects of normal tissue, subjective, objective, management, analytic (LENT/SOMA) scale was used to score the RT reactions. The correlation between the occurrence and severity of acute and late bowel and bladder toxicity, as well as the relationship between the severity of acute effects and time to occurrence of late reactions, were assessed using linear and logistic regression analyses. Results: Of the 317 patients, 268 (85%) experienced acute RT reactions of any grade. Severe acute bowel reactions were observed in 15 patients (5%), urinary bladder complications in 1 patient (0.5%), cutaneous in 1 patient (0.5%), and vaginal in 1 patient (0.5%). Severe acute hematologic toxicity was seen in 3 patients (1%). A total of 158 patients (51%) experienced late RT reactions of any grade. Severe late bowel reactions were observed in 19 patients (6%), urinary bladder in 5 (2%), vaginal in 3 (1%), and bone in 10 (4%). When all toxic events were considered, there was a highly significant correlation between the acute and late bowel reactions (p <0.001), but the acute and late urinary bladder reactions did not correlate (p=0.64). The grade of acute toxicity was found to predict the grade of late toxicity for the bowel but not for the bladder (p<0.001 and p=0.47, respectively). The severity of acute

  18. Analytical Solution for Time-drawdown Response to Constant Pumping from a Homogeneous, Confined Horizontal Aquifer with Unidirectional Flow

    Science.gov (United States)

    Parrish, K. E.; Zhang, J.; Teasdale, E.

    2007-12-01

    An exact analytical solution to the ordinary one-dimensional partial differential equation is derived for transient groundwater flow in a homogeneous, confined, horizontal aquifer using Laplace transformation. The theoretical analysis is based on the assumption that the aquifer is homogeneous and one-dimensional (horizontal); confined between impermeable formations on top and bottom; and of infinite horizontal extent and constant thickness. It is also assumed that there is only a single pumping well penetrating the entire aquifer; flow is everywhere horizontal within the aquifer to the well; the well is pumping with a constant discharge rate; the well diameter is infinitesimally small; and the hydraulic head is uniform throughout the aquifer before pumping. Similar to the Theis solution, this solution is suited to determine transmissivity and storativity for a two- dimensional, vertically confined aquifer, such as a long vertically fractured zone of high permeability within low permeable rocks or a long, high-permeability trench inside a low-permeability porous media. In addition, it can be used to analyze time-drawdown responses to pumping and injection in similar settings. The solution can also be used to approximate the groundwater flow for unconfined conditions if (1) the variation of transmissivity is negligible (groundwater table variation is small in comparison to the saturated thickness); and (2) the unsaturated flow is negligible. The errors associated with the use of the solution to unconfined conditions depend on the accuracies of the above two assumptions. The solution can also be used to assess the impacts of recharge from a seasonal river or irrigation canal on the groundwater system by assuming uniform, time- constant recharge along the river or canal. This paper presents the details for derivation of the analytical solution. The analytical solution is compared to numerical simulation results with example cases. Its accuracy is also assessed and

  19. Solution of radial spin-1 field equation in Robertson-Walker space-time via Heun's equation

    International Nuclear Information System (INIS)

    Zecca, A.

    2010-01-01

    The spin-1 field equation is considered in Robertson-Walker spacetime. The problem of the solution of the separated radial equations, previously discussed in the flat space-time case, is solved also for both the closed and open curvature case. The radial equation is reduced to Heun's differential equation that recently has been widely reconsidered. It is shown that the solution of the present Heun equation does not fall into the class of polynomial-like or hypergeometric functions. Heun's operator results also non-factorisable. The properties follow from application of general theorems and power series expansion. In the positive curvature case of the universe a discrete energy spectrum of the system is found. The result follows by requiring a polynomial-like behaviour of at least one component of the spinor field. Developments and applications of the theory suggest further study of the solution of Heun's equation.

  20. Sedimentary architecture and chronostratigraphy of a late Quaternary incised-valley fill: A case study of the late Middle and Late Pleistocene Rhine system in the Netherlands

    Science.gov (United States)

    Peeters, J.; Busschers, F. S.; Stouthamer, E.; Bosch, J. H. A.; Van den Berg, M. W.; Wallinga, J.; Versendaal, A. J.; Bunnik, F. P. M.; Middelkoop, H.

    2016-01-01

    This paper describes the sedimentary architecture, chronostratigraphy and palaeogeography of the late Middle and Late Pleistocene (Marine Isotope Stage/MIS 6-2) incised Rhine-valley fill in the central Netherlands based on six geological transects, luminescence dating, biostratigraphical data and a 3D geological model. The incised-valley fill consists of a ca. 50 m thick and 10-20 km wide sand-dominated succession and includes a well-developed sequence dating from the Last Interglacial: known as the Eemian in northwest Europe. The lower part of the valley fill contains coarse-grained fluvio-glacial and fluvial Rhine sediments that were deposited under Late Saalian (MIS 6) cold-climatic periglacial conditions and during the transition into the warm Eemian interglacial (MIS 5e-d). This unit is overlain by fine-grained fresh-water flood-basin deposits, which are transgressed by a fine-grained estuarine unit that formed during marine high-stand. This ca. 10 m thick sequence reflects gradual drowning of the Eemian interglacial fluvial Rhine system and transformation into an estuary due to relative sea-level rise. The chronological data suggests a delay in timing of regional Eemian interglacial transgression and sea-level high-stand of several thousand years, when compared to eustatic sea-level. As a result of this glacio-isostatic controlled delay, formation of the interglacial lower deltaic system took only place for a relative short period of time: progradation was therefore limited. During the cooler Weichselian Early Glacial period (MIS 5d-a) deposition of deltaic sediments continued and extensive westward progradation of the Rhine system occurred. Major parts of the Eemian and Weichselian Early Glacial deposits were eroded and buried as a result of sea-level lowering and climate cooling during the early Middle Weichselian (MIS 4-3). Near complete sedimentary preservation occurred along the margins of the incised valley allowing the detailed reconstruction presented

  1. Methods for providing decision makers with optimal solutions for multiple objectives that change over time

    CSIR Research Space (South Africa)

    Greeff, M

    2010-09-01

    Full Text Available Decision making - with the goal of finding the optimal solution - is an important part of modern life. For example: In the control room of an airport, the goals or objectives are to minimise the risk of airplanes colliding, minimise the time that a...

  2. Scheduling with time-dependent execution times

    NARCIS (Netherlands)

    Woeginger, G.J.

    1995-01-01

    We consider systems of tasks where the task execution times are time-dependent and where all tasks have some common deadline. We describe how to compute in polynomial time a schedule that minimizes the number of late tasks. This answers a question raised in a recent paper by Ho, Leung and Wei.

  3. Surfactant therapy in late preterm infants

    Directory of Open Access Journals (Sweden)

    Murat Yurdakök

    2013-06-01

    Full Text Available Late preterm (LPT neonates are at a high risk for respiratory distress soon after birth due to respiratory distress syndrome (RDS, transient tachypnea of the newborn, persistent pulmonary hypertension, and pneumonia along with an increased need for surfactant replacement therapy, continuous positive airway pressure, and ventilator support when compared with the term neonates. In the past, studies on outcomes of infants with respiratory distress have primarily focused on extremely premature infants, leading to a gap in knowledge and understanding of the developmental biology and mechanism of pulmonary diseases in LPT neonates. Surfactant deficiency is the most frequent etiology of RDS in very preterm and moderately preterm infants, while cesarean section and lung infection play major roles in RDS development in LPT infants. The clinical presentation and the response to surfactant therapy in LPT infants may be different than that seen in very preterm infants. Incidence of pneumonia and occurrence of pneumothorax are significantly higher in LPT and term infants. High rates of pneumonia in these infants may result in direct injury to the type II alveolar cells of the lung with decreasing synthesis, release, and processing of surfactant. Increased permeability of the alveolar capillary membrane to both fluid and solutes is known to result in entry of plasma proteins into the alveolar hypophase, further inhibiting the surface properties of surfactant. However, the oxygenation index value do not change dramatically after ventilation or surfactant administration in LPT infants with RDS compared to very preterm infants. These finding may indicate a different pathogenesis of RDS in late preterm and term infants. In conclusion, surfactant therapy may be of significant benefit in LPT infants with serious respiratory failure secondary to a number of insults. However, optimal timing and dose of administration are not so clear in this group. Additional

  4. Late Globalization and Evolution, Episodes and Epochs of Industries

    DEFF Research Database (Denmark)

    Turcan, Romeo V.; Boujarzadeh, Behnam; Dholakia, Nikhilesh

    While the empirical focus of this paper is the Danish Textile and Fashion Industry (DTFI) – specifically the episodes and epochs in the emergence and evolution of DTFI, in essence the micro and macro time-slices – the theoretical intent is wider. We aim to explore the conceptual terrain of what we...... for further exploration of the late globalization phenomenon. To get to the empirical case study, we follow a macro-conceptual to a micro-empirical path. We discuss the multidisciplinary and multifaceted field of late globalization and employing the historic-analytic approach to study DTFI we draw out very...... specific, empirically derived, conceptual themes about the patterns of global interactions that characterized the evolutionary trajectory of DTFI. We return to a final macro-conceptual section on late globalization where the particular DTFI case study advances the knowledge register only slightly; and we...

  5. Upscaling solute transport in naturally fractured porous media with the continuous time random walk method

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, S.; Cortis, A.; Birkholzer, J.T.

    2010-04-01

    Solute transport in fractured porous media is typically 'non-Fickian'; that is, it is characterized by early breakthrough and long tailing and by nonlinear growth of the Green function-centered second moment. This behavior is due to the effects of (1) multirate diffusion occurring between the highly permeable fracture network and the low-permeability rock matrix, (2) a wide range of advection rates in the fractures and, possibly, the matrix as well, and (3) a range of path lengths. As a consequence, prediction of solute transport processes at the macroscale represents a formidable challenge. Classical dual-porosity (or mobile-immobile) approaches in conjunction with an advection-dispersion equation and macroscopic dispersivity commonly fail to predict breakthrough of fractured porous media accurately. It was recently demonstrated that the continuous time random walk (CTRW) method can be used as a generalized upscaling approach. Here we extend this work and use results from high-resolution finite element-finite volume-based simulations of solute transport in an outcrop analogue of a naturally fractured reservoir to calibrate the CTRW method by extracting a distribution of retention times. This procedure allows us to predict breakthrough at other model locations accurately and to gain significant insight into the nature of the fracture-matrix interaction in naturally fractured porous reservoirs with geologically realistic fracture geometries.

  6. Long-Time Behaviour of Solutions for Autonomous Evolution Hemivariational Inequality with Multidimensional “Reaction-Displacement” Law

    Directory of Open Access Journals (Sweden)

    Pavlo O. Kasyanov

    2012-01-01

    Full Text Available We consider autonomous evolution inclusions and hemivariational inequalities with nonsmooth dependence between determinative parameters of a problem. The dynamics of all weak solutions defined on the positive semiaxis of time is studied. We prove the existence of trajectory and global attractors and investigate their structure. New properties of complete trajectories are justified. We study classes of mathematical models for geophysical processes and fields containing the multidimensional “reaction-displacement” law as one of possible application. The pointwise behavior of such problem solutions on attractor is described.

  7. Asymptotic solution for the El Niño time delay sea—air oscillator model

    International Nuclear Information System (INIS)

    Mo Jia-Qi; Lin Wan-Tao; Lin Yi-Hua

    2011-01-01

    A sea—air oscillator model is studied using the time delay theory. The aim is to find an asymptotic solving method for the El Niño-southern oscillation (ENSO) model. Employing the perturbed method, an asymptotic solution of the corresponding problem is obtained. Thus we can obtain the prognoses of the sea surface temperature (SST) anomaly and the related physical quantities. (general)

  8. Four positive periodic solutions of a discrete time Lotka-Volterra competitive system with harvesting terms

    Directory of Open Access Journals (Sweden)

    Xinggui Liu

    2011-01-01

    Full Text Available In this paper, by using Mawhin's continuation theorem of coincidence degree theory, we establish the existence of at least four positive periodic solutions for a discrete time Lotka-Volterra competitive system with harvesting terms. An example is given to illustrate the effectiveness of our results.

  9. Late onset corneal ectasia after LASIK surgery.

    Science.gov (United States)

    Said, Ashraf; Hamade, Issam H; Tabbara, Khalid F

    2011-07-01

    To report late onset corneal ectasia following myopic LASIK. A retrospective cohort case series. Nineteen patients with late onset corneal ectasia following LASIK procedure were examined at The Eye Center, Riyadh, Saudi Arabia. Patients underwent LASIK for myopia with spherical equivalent ranging from -1.4 to -13.75 diopters. Age and gender, history of systemic or local diseases, and time of onset of corneal ectasia were recorded. Eye examination and corneal topographical analyses were done before and after LASIK surgery. Nineteen patients (29 eyes) with late onset corneal ectasia were identified from 1998 to 2008 in 13 male and six female patients. The mean follow-up period was 108 ± 23 months (range 72-144 months). No patient had pre-operative identifiable risk factors for corneal ectasia and the mean time of onset was 57 ± 24 months (range 24-120 months after LASIK). The pre-operative values included mean central pachymetry 553 ± 25 μm, mean keratometry reading of 42.9 ± 1.5 diopters, average oblique cylinder of 1.4 ± 1.2 diopters, posterior surface elevation of 26 ± 2.1 diopters, corneal flap thickness of 160 μm, mean spherical equivalent of -5.6 ± 3.6 diopters, and calculated residual corneal stromal bed thickness was 288 ± 35 μm. Three (5 eyes) patients developed ectasia after pregnancy. Three (4 eyes) patients developed corneal ectasia following severe adenoviral keratoconjunctivitis and had positive PCR for adenovirus type 8. Corneal ectasia may develop many years after LASIK surgery and symptoms could go undetected for some time. Pregnancy and adenoviral keratoconjunctivitis occurred post-operatively in six patients.

  10. Late effects from hadron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, Eleanor A.; Chang, Polly Y.

    2004-06-01

    Successful cancer patient survival and local tumor control from hadron radiotherapy warrant a discussion of potential secondary late effects from the radiation. The study of late-appearing clinical effects from particle beams of protons, carbon, or heavier ions is a relatively new field with few data. However, new clinical information is available from pioneer hadron radiotherapy programs in the USA, Japan, Germany and Switzerland. This paper will review available data on late tissue effects from particle radiation exposures, and discuss its importance to the future of hadron therapy. Potential late radiation effects are associated with irradiated normal tissue volumes at risk that in many cases can be reduced with hadron therapy. However, normal tissues present within hadron treatment volumes can demonstrate enhanced responses compared to conventional modes of therapy. Late endpoints of concern include induction of secondary cancers, cataract, fibrosis, neurodegeneration, vascular damage, and immunological, endocrine and hereditary effects. Low-dose tissue effects at tumor margins need further study, and there is need for more acute molecular studies underlying late effects of hadron therapy.

  11. Preliminary Formulation of Finite Element Solution for the 1-D, 1-G Time Dependent Neutron Diffusion Equation without Consideration about Delay Neutron

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Eun Hyun; Song, Yong Mann; Park, Joo Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    If time-dependent equation is solved with the FEM, the limitation of the input geometry will disappear. It has often been pointed out that the numerical methods implemented in the RFSP code are not state-of-the-art. Although an acceleration method such as the Coarse Mesh Finite Difference (CMFD) for Finite Difference Method (FDM) does not exist for the FEM, one should keep in mind that the number of time steps for the transient simulation is not large. The rigorous formulation in this study will richen the theoretical basis of the FEM and lead to an extension of the dynamics code to deal with a more complicated problem. In this study, the formulation for the 1-D, 1-G Time Dependent Neutron Diffusion Equation (TDNDE) without consideration of the delay neutron will first be done. A problem including one multiplying medium will be solved. Also several conclusions from a comparison between the numerical and analytic solutions, a comparison between solutions with various element orders, and a comparison between solutions with different time differencing will be made to be certain about the formulation and FEM solution. By investigating various cases with different values of albedo, theta, and the order of elements, it can be concluded that the finite element solution is agree well with the analytic solution. The higher the element order used, the higher the accuracy improvements are obtained.

  12. Viscous Corrections of the Time Incremental Minimization Scheme and Visco-Energetic Solutions to Rate-Independent Evolution Problems

    Science.gov (United States)

    Minotti, Luca; Savaré, Giuseppe

    2018-02-01

    We propose the new notion of Visco-Energetic solutions to rate-independent systems {(X, E,} d) driven by a time dependent energy E and a dissipation quasi-distance d in a general metric-topological space X. As for the classic Energetic approach, solutions can be obtained by solving a modified time Incremental Minimization Scheme, where at each step the dissipation quasi-distance d is incremented by a viscous correction {δ} (for example proportional to the square of the distance d), which penalizes far distance jumps by inducing a localized version of the stability condition. We prove a general convergence result and a typical characterization by Stability and Energy Balance in a setting comparable to the standard energetic one, thus capable of covering a wide range of applications. The new refined Energy Balance condition compensates for the localized stability and provides a careful description of the jump behavior: at every jump the solution follows an optimal transition, which resembles in a suitable variational sense the discrete scheme that has been implemented for the whole construction.

  13. Unscented Kalman filter assimilation of time-lapse self-potential data for monitoring solute transport

    Science.gov (United States)

    Cui, Yi-an; Liu, Lanbo; Zhu, Xiaoxiong

    2017-08-01

    Monitoring the extent and evolution of contaminant plumes in local and regional groundwater systems from existing landfills is critical in contamination control and remediation. The self-potential survey is an efficient and economical nondestructive geophysical technique that can be used to investigate underground contaminant plumes. Based on the unscented transform, we have built a Kalman filtering cycle to conduct time-lapse data assimilation for monitoring the transport of solute based on the solute transport experiment using a bench-scale physical model. The data assimilation was formed by modeling the evolution based on the random walk model and observation correcting based on the self-potential forward. Thus, monitoring self-potential data can be inverted by the data assimilation technique. As a result, we can reconstruct the dynamic process of the contaminant plume instead of using traditional frame-to-frame static inversion, which may cause inversion artifacts. The data assimilation inversion algorithm was evaluated through noise-added synthetic time-lapse self-potential data. The result of the numerical experiment shows validity, accuracy and tolerance to the noise of the dynamic inversion. To validate the proposed algorithm, we conducted a scaled-down sandbox self-potential observation experiment to generate time-lapse data that closely mimics the real-world contaminant monitoring setup. The results of physical experiments support the idea that the data assimilation method is a potentially useful approach for characterizing the transport of contamination plumes using the unscented Kalman filter (UKF) data assimilation technique applied to field time-lapse self-potential data.

  14. A numerical solution for a class of time fractional diffusion equations with delay

    Directory of Open Access Journals (Sweden)

    Pimenov Vladimir G.

    2017-09-01

    Full Text Available This paper describes a numerical scheme for a class of fractional diffusion equations with fixed time delay. The study focuses on the uniqueness, convergence and stability of the resulting numerical solution by means of the discrete energy method. The derivation of a linearized difference scheme with convergence order O(τ2−α+ h4 in L∞-norm is the main purpose of this study. Numerical experiments are carried out to support the obtained theoretical results.

  15. A Summary of the Space-Time Conservation Element and Solution Element (CESE) Method

    Science.gov (United States)

    Wang, Xiao-Yen J.

    2015-01-01

    The space-time Conservation Element and Solution Element (CESE) method for solving conservation laws is examined for its development motivation and design requirements. The characteristics of the resulting scheme are discussed. The discretization of the Euler equations is presented to show readers how to construct a scheme based on the CESE method. The differences and similarities between the CESE method and other traditional methods are discussed. The strengths and weaknesses of the method are also addressed.

  16. On Some New Properties of the Fundamental Solution to the Multi-Dimensional Space- and Time-Fractional Diffusion-Wave Equation

    Directory of Open Access Journals (Sweden)

    Yuri Luchko

    2017-12-01

    Full Text Available In this paper, some new properties of the fundamental solution to the multi-dimensional space- and time-fractional diffusion-wave equation are deduced. We start with the Mellin-Barnes representation of the fundamental solution that was derived in the previous publications of the author. The Mellin-Barnes integral is used to obtain two new representations of the fundamental solution in the form of the Mellin convolution of the special functions of the Wright type. Moreover, some new closed-form formulas for particular cases of the fundamental solution are derived. In particular, we solve the open problem of the representation of the fundamental solution to the two-dimensional neutral-fractional diffusion-wave equation in terms of the known special functions.

  17. Stability of time-dependent particle-like solutions of some wave equations

    International Nuclear Information System (INIS)

    Voronov, N.A.

    1978-01-01

    The proof of the nonstability of the one-dimensional periodical localized solutions of the equation with a spontaneously broken symmetry is given. The stability of the one-dimensional oscillating solutions of the sine-Gordon equation was also considered with regard to such perturbations. As it was expected these solutions proved to be stable

  18. Time resolved fluorescence anisotropy of basic dyes bound to poly(methacrylic acid in solution

    Directory of Open Access Journals (Sweden)

    Oliveira Hueder Paulo M. de

    2003-01-01

    Full Text Available Solutions of atactic poly(methacrylic acid, PMAA, with molecular weights in the range of (1.6 to 3.4 x 10(5 g mol-1, and labeled with the fluorescent dyes 9-aminoacridine or Nile blue were studied by photophysical measurements as a function of solvent viscosity and polarity. The conformational behavior of the PMAA chain segments around the fluorescent probe was reported by the change in the rotational diffusion of the dyes. Ethylene glycol swells the polymer chain compared with the more contracted conformation of PMAA in 50% water/ethylene glycol. The change in the rotational relaxation time of the dye bound to PMAA with the decrease of water content in the solvent mixture indicates a progressive expansion of polymer chain to a more open coil form in solution.

  19. Strong late-time circumstellar interaction in the peculiar supernova iPTF14hls

    Science.gov (United States)

    Andrews, Jennifer E.; Smith, Nathan

    2018-06-01

    We present a moderate-resolution spectrum of the peculiar Type II supernova (SN) iPTF14hls taken on day 1153 after discovery. This spectrum reveals the clear signature of shock interaction with dense circumstellar material (CSM). We suggest that this CSM interaction may be an important clue for understanding the extremely unusual photometric and spectroscopic evolution seen over the first 600 d of iPTF14hls. The late-time spectrum shows a double-peaked intermediate-width H α line indicative of expansion speeds around 1000 km s-1, with the double-peaked shape hinting at a disc-like geometry in the CSM. If the CSM were highly asymmetric, perhaps in a disc or torus that was ejected from the star 3-6 yr prior to explosion, the CSM interaction could have been overrun and hidden below the SN ejecta photosphere from a wide range of viewing angles. In that case, CSM interaction luminosity would have been thermalized well below the photosphere, potentially sustaining the high luminosity without exhibiting the traditional observational signatures of strong CSM interaction (narrow H α emission and X-rays). Variations in density structure of the CSM could account for the multiple rebrightenings of the light curve. We propose that a canonical 1 × 1051 erg explosion energy with enveloped CSM interaction as seen in some recent SNe, rather than an entirely new explosion mechanism, may be adequate to explain the peculiar evolution of iPTF14hls.

  20. Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia.

    Science.gov (United States)

    Fenske, Myles P; Hewett Hazelton, Kristen D; Hempton, Andrew K; Shim, Jae Sung; Yamamoto, Breanne M; Riffell, Jeffrey A; Imaizumi, Takato

    2015-08-04

    Flowers present a complex display of signals to attract pollinators, including the emission of floral volatiles. Volatile emission is highly regulated, and many species restrict emissions to specific times of the day. This rhythmic emission of scent is regulated by the circadian clock; however, the mechanisms have remained unknown. In Petunia hybrida, volatile emissions are dominated by products of the floral volatile benzenoid/phenylpropanoid (FVBP) metabolic pathway. Here we demonstrate that the circadian clock gene P. hybrida LATE ELONGATED HYPOCOTYL (LHY; PhLHY) regulates the daily expression patterns of the FVBP pathway genes and floral volatile production. PhLHY expression peaks in the morning, antiphasic to the expression of P. hybrida GIGANTEA (PhGI), the master scent regulator ODORANT1 (ODO1), and many other evening-expressed FVBP genes. Overexpression phenotypes of PhLHY in Arabidopsis caused an arrhythmic clock phenotype, which resembles those of LHY overexpressors. In Petunia, constitutive expression of PhLHY depressed the expression levels of PhGI, ODO1, evening-expressed FVBP pathway genes, and FVBP emission in flowers. Additionally, in the Petunia lines in which PhLHY expression was reduced, the timing of peak expression of PhGI, ODO1, and the FVBP pathway genes advanced to the morning. Moreover, PhLHY protein binds to cis-regulatory elements called evening elements that exist in promoters of ODO1 and other FVBP genes. Thus, our results imply that PhLHY directly sets the timing of floral volatile emission by restricting the expression of ODO1 and other FVBP genes to the evening in Petunia.

  1. VERY LATE PHOTOMETRY OF SN 2011fe

    International Nuclear Information System (INIS)

    Kerzendorf, W. E.; Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J.

    2014-01-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ≈930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of 56 Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs

  2. On the de Sitter and Nariai solutions in general relativity and their extension in higher dimensional space-time

    International Nuclear Information System (INIS)

    Nariai, Hidekazu; Ishihara, Hideki.

    1983-01-01

    Various geometrical properties of Nariai's less-familiar solution of the vacuum Einstein equations R sub( mu nu ) = lambda g sub( mu nu ) is f irst summarized in comparison with de Sitter's well-known solution. Next an extension of both solutions is performed in a six-dimensional space on the supposition that such an extension will in future become useful to elucidate more closely the creation of particles in an inflationary stage of the big-bang universe. For preparation, the behavior of a massive scalar field in the extended space-time is studied in a classical level. (author)

  3. Personality in Late Midlife

    DEFF Research Database (Denmark)

    Mortensen, Erik Lykke; Flensborg-Madsen, Trine; Molbo, Drude

    2014-01-01

    To analyze associations in late midlife between sex, age, education and social class, and the Big Five personality traits; to analyze associations between personality traits and cognitive ability in late midlife; and to evaluate how these associations are influenced by demographic factors....

  4. HIV impact on women: gender difference among late testers and advanced HIV infection

    Science.gov (United States)

    Sukmawati, N. M. D. D.; Merati, T. P.; Somia, A.; Utama, S.; Gayatri, Y.

    2018-03-01

    This study reported the effect of gender difference on HIV seropositive late testers or advanced infection. A retrospective cohort study of newly diagnosed HIV seropositive based on adatabase in the main referral hospital in Denpasar, Bali, Indonesia from 2004 – 2016. Women and man were categorized as late testers (CD4 ≤ 200 cells/uL and/or AIDS diagnosis ≤ 12 months from first HIV test date). Non-late testers (CD4 > 200 cells/uL and/or no AIDS diagnosis during study period or diagnosis of AIDS >12 months from HIV diagnosis), of reproductive age (13 – 49 years old), and not of reproductive age (>49 years old). Logistic regression was used to estimate risk and its statistical significance. The model consists of gender and age correctly classified 83.5% of cases. Women were almost two times more likely to present as non-late testers compared to men, and reproductive age of 15 – 49 years were 1.5 times more likely to present as non-late testers compared to those with age > 49 years. Women affected by HIV almost in equal as for men. Women and those within reproductive age were more likely to present before the advanced stage compared to men and those aged > 49 years.

  5. Experimental test of depth dependence of solutions for time-resolved diffusion equation

    Energy Technology Data Exchange (ETDEWEB)

    Laidevant, A.; Da Silva, A.; Moy, J.P.; Berger, M.; Dinten, J.M

    2004-07-01

    The determination of optical properties of a semi-infinite medium such as biological tissue has been widely investigated by many authors. Reflectance formulas can be derived from the diffusion equation for different boundary conditions at the medium-air interface. This quantity can be measured at the medium surface. For realistic objects, such as a mouse, tissue optical properties can realistically only be determined at the object surface. However, near the surface diffusion approximation is weak and boundary models have to be considered. In order to investigate the validity of the time resolved reflectance approach at the object boundary, we have estimated optical properties of a liquid semi-infinite medium by this method for different boundary conditions and different fiber's position beneath the surface. The time-correlated single photon counting (TCSPC) technique is used to measure the reflectance curve. Our liquid phantoms are made of water, Intra-lipid and Ink. Laser light is delivered by a pulsed laser diode. Measurements are then fitted to theoretical solutions expressed as a function of source and detector's depth and distance. By taking as reference the optical properties obtained from the infinite model for fibers deeply immersed, influence of the different boundary conditions and bias induced are established for different fibers' depth and a variety of solutions. This influence is analysed by comparing evolution of the reflectance models, as well as estimations of absorption and scattering coefficients. According to this study we propose a strategy for determining optical properties of a solid phantom where measurements can only be realized at the surface. (authors)

  6. Unmatched Case-Control Study on Late Presentation of HIV Infection in Santiago, Cape Verde (2004-2011).

    Science.gov (United States)

    Moreira, António L; Fronteira, Inês; Augusto, Gonçalo Figueiredo; Martins, Maria Rosario O

    2016-03-15

    Access to free antiretroviral therapy (ART) in Sub-Saharan Africa has been steadily increasing over the past decade. However, the success of large-scale ART programmes depends on timely diagnosis and early initiation of HIV care. This study characterizes late presenters to HIV care in Santiago (Cape Verde) between 2004 and 2011, and identifies factors associated with late presentation for care. We defined late presentation as persons presenting to HIV care with a CD4 count below 350 cells/mm³. An unmatched case-control study was conducted using socio-demographic and behavioural data of 368 individuals (191 cases and 177 controls) collected through an interviewer-administered questionnaire, comparing HIV patients late and early presented to care. Logistic regression was performed to estimate odds ratio and 95% confidence intervals. Results show that 51.9% were late presenters for HIV. No differences were found in gender distribution, marital status, or access to health services between cases and controls. Participants who undertook an HIV test by doctor indication were more likely to present late compared with those who tested for HIV by their own initiative. Also, individuals taking less time to initiate ART are more likely to present late. This study highlights the need to better understand reasons for late presentation to HIV care in Cape Verde. People in older age groups should be targeted in future approaches focused on late presenters to HIV care.

  7. Cognitive advantages and disadvantages in early and late bilinguals.

    Science.gov (United States)

    Pelham, Sabra D; Abrams, Lise

    2014-03-01

    Previous research has documented advantages and disadvantages of early bilinguals, defined as learning a 2nd language by school age and using both languages since that time. Relative to monolinguals, early bilinguals manifest deficits in lexical access but benefits in executive function. We investigated whether becoming bilingual after childhood (late bilinguals) can produce the cognitive advantages and disadvantages typical of early bilinguals. Participants were 30 monolingual English speakers, 30 late English-Spanish bilinguals, and 30 early Spanish-English bilinguals who completed a picture naming task (lexical access) and an attentional network task (executive function). Late and early bilinguals manifested equivalent cognitive effects in both tasks, demonstrating lexical access deficits and executive function benefits. These findings provide support for the hypothesis that cognitive effects associated with bilingualism arise as the result of proficient, habitual use of 2 languages and not of developmental changes associated with becoming bilingual during childhood.

  8. Divergent series and memory of the initial condition in the long-time solution of some anomalous diffusion problems.

    Science.gov (United States)

    Yuste, S Bravo; Borrego, R; Abad, E

    2010-02-01

    We consider various anomalous d -dimensional diffusion problems in the presence of an absorbing boundary with radial symmetry. The motion of particles is described by a fractional diffusion equation. Their mean-square displacement is given by r(2) proportional, variant t(gamma)(0divergent series appear when the concentration or survival probabilities are evaluated via the method of separation of variables. While the solution for normal diffusion problems is, at most, divergent as t-->0 , the emergence of such series in the long-time domain is a specific feature of subdiffusion problems. We present a method to regularize such series, and, in some cases, validate the procedure by using alternative techniques (Laplace transform method and numerical simulations). In the normal diffusion case, we find that the signature of the initial condition on the approach to the steady state rapidly fades away and the solution approaches a single (the main) decay mode in the long-time regime. In remarkable contrast, long-time memory of the initial condition is present in the subdiffusive case as the spatial part Psi1(r) describing the long-time decay of the solution to the steady state is determined by a weighted superposition of all spatial modes characteristic of the normal diffusion problem, the weight being dependent on the initial condition. Interestingly, Psi1(r) turns out to be independent of the anomalous diffusion exponent gamma .

  9. Late somatic sequelae after treatment of childhood cancer in Slovenia

    Directory of Open Access Journals (Sweden)

    Erman Nuša

    2012-05-01

    Full Text Available Abstract Background This is a long-term follow-up clinical study of adolescents and adults, survivors of childhood cancer. We evaluate and analyze the late somatic sequelae of childhood cancer treatment. Many such studies are susceptible to a strong selection bias, i.e., they employ a limited non-systematic sample of patients, based on a clinical hospital that provided the cancer treatment or performed the follow-up. To address the issue of selection bias, we perform here an analysis of late sequelae on a systematic database of the entire population of the children treated for cancer in Slovenia. Due to the specifics of cancer treatment procedures in Slovenia, they have all been treated and followed-up in the same clinic. Methods The data are based on the centralized registry of cancer patients in Slovenia and present a controlled and homogeneous collection. Late sequelae are evaluated following a modified CTCAE, i.e., the National Cancer Institute’s Common Terminology Criteria for Adverse Events version 3.0. We use survival analysis method to estimate the incidence of and risk for late sequelae, where the time variable is measured in years from the diagnosis date, while we follow the event of incidence of late sequelae scored other than none. Survival analysis is performed using KaplanMeier estimator and Cox regression model. Results The incidence of mild, moderate, or severe late sequelae of childhood cancer treatment significantly decreased from 75% in the group of patients diagnosed before 1975 to 55% for those diagnosed after 1995. The Cox regression analysis of the risk factors for the incidence of late sequelae identifies three significant factors: treatment modalities, age at diagnosis, and primary diagnosis. Conclusions The change of treatment modalities in terms of replacement of surgery and radiotherapy with chemotherapy is the main reason for the decrease of the incidence and the risk for late sequelae of childhood cancer treatment

  10. Late time properties of a decaying false vacuum

    International Nuclear Information System (INIS)

    Urbanowski, K.

    2014-01-01

    The false vacuum states are unstable and they decay by tunneling. Some of them may survive up to times when their survival probability has a non-exponential form. At times much latter than the transition time, when contributions to the survival probability of its exponential and non-exponential parts are comparable, the survival probability as a function of time t has an inverse power-like form. We show that at this time region the instantaneous energy of the false vacuum states tends to the energy of the true vacuum state as 1/t 2 for t → ∞. (author)

  11. Parallel processing for a 1-D time-dependent solution to impurity rate equations for fusion plasma simulations

    International Nuclear Information System (INIS)

    Veerasingam, R.

    1990-01-01

    In fusion plasmas impurities such as carbon, oxygen or nickel can contaminate the plasma and cause degradation of the performance of a fusion device through radiation. However, impurities can also be used as diagnostics to obtain information about a plasma through spectroscopic experiments which can then be used in plasma modeling and simulations. In the past, serial algorithms have been described for either the time dependent or steady state problem. In this paper, we describe a parallel procedure adopted to solve the time-dependent problem. It can be shown that for the steady state problem a parallel procedure would not be a useful application of parallelization because a few seconds of the Central Processing Unit time on a CRAY-XMP or IBM 3090/600S would suffice to obtain the solution, while this is not the case for the time-dependent problem. In order to study the effects of low Z and high Z impurities on the final state of a plasma, time-dependent solutions are necessary. For purposes of diagnostics and comparisons with experiments, a fast turn around time of the simulations would be advantageous. We have implemented a parallel algorithm on and IBM 3090/600S and tested its performance for a typical set of fusion plasma parameters. 4 refs., 1 tab

  12. Stability of small-amplitude periodic solutions near Hopf bifurcations in time-delayed fully-connected PLL networks

    Science.gov (United States)

    Ferruzzo Correa, Diego P.; Bueno, Átila M.; Castilho Piqueira, José R.

    2017-04-01

    In this paper we investigate stability conditions for small-amplitude periodic solutions emerging near symmetry-preserving Hopf bifurcations in a time-delayed fully-connected N-node PLL network. The study of this type of systems which includes the time delay between connections has attracted much attention among researchers mainly because the delayed coupling between nodes emerges almost naturally in mathematical modeling in many areas of science such as neurobiology, population dynamics, physiology and engineering. In a previous work it has been shown that symmetry breaking and symmetry preserving Hopf bifurcations can emerge in the parameter space. We analyze the stability along branches of periodic solutions near fully-synchronized Hopf bifurcations in the fixed-point space, based on the reduction of the infinite-dimensional space onto a two-dimensional center manifold in normal form. Numerical results are also presented in order to confirm our analytical results.

  13. CCD Parallaxes for 309 Late-type Dwarfs and Subdwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Dahn, Conard C.; Harris, Hugh C.; Subasavage, John P.; Ables, Harold D.; Guetter, Harry H.; Harris, Fred H.; Luginbuhl, Christian B.; Monet, Alice B.; Monet, David G.; Munn, Jeffrey A.; Pier, Jeffrey R.; Stone, Ronald C.; Vrba, Frederick J.; Walker, Richard L.; Tilleman, Trudy M. [US Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Road, Flagstaff, AZ 86005-8521 (United States); Canzian, Blaise J. [L-3 Communications/Brashear, 615 Epsilon Drive, Pittsburgh, PA 15238-2807 (United States); Henden, Arne H. [AAVSO, Cambridge, MA 02138 (United States); Leggett, S. K. [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Levine, Stephen E., E-mail: jsubasavage@nofs.navy.mil [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001-4499 (United States)

    2017-10-01

    New, updated, and/or revised CCD parallaxes determined with the Strand Astrometric Reflector at the Naval Observatory Flagstaff Station are presented. Included are results for 309 late-type dwarf and subdwarf stars observed over the 30+ years that the program operated. For 124 of the stars, parallax determinations from other investigators have already appeared in the literature and we compare the different results. Also included here are new or updated VI photometry on the Johnson–Kron-Cousins system for all but a few of the faintest targets. Together with 2MASS JHK{sub s} near-infrared photometry, a sample of absolute magnitude versus color and color versus color diagrams are constructed. Because large proper motion was a prime criterion for targeting the stars, the majority turn out to be either M-type subdwarfs or late M-type dwarfs. The sample also includes 50 dwarf or subdwarf L-type stars, and four T dwarfs. Possible halo subdwarfs are identified in the sample based on tangential velocity, subluminosity, and spectral type. Residuals from the solutions for parallax and proper motion for several stars show evidence of astrometric perturbations.

  14. Solutions of weakened field equations in Gödel space-time

    Directory of Open Access Journals (Sweden)

    Aditya Mani Mishra

    2019-04-01

    Full Text Available We have solved Weakened field equations, collected work of Lovelock for cylindrically symmetric G¨odel type spacetime. A comparative study of these solutions to solution of Einstein’s field equation have shown. Conformality of Gödel spacetime has discussed with vanishing and non-vanishing scalar curvature of the spacetime.

  15. Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

    Energy Technology Data Exchange (ETDEWEB)

    Cui, B.-Y.; McLaughlin, M. A. [Department of Physics and Astronomy West Virginia University Morgantown, WV 26506 (United States); Boyles, J. [Department of Physics and Astronomy West Kentucky University Bowling Green, KY 42101 (United States); Palliyaguru, N. [Physics and Astronomy Department Texas Tech University Lubbock, TX 79409-1051 (United States)

    2017-05-01

    Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb–Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623−0841 and 0.7 hr for PSR J1839−0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

  16. Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

    Science.gov (United States)

    Cui, B.-Y.; Boyles, J.; McLaughlin, M. A.; Palliyaguru, N.

    2017-05-01

    Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb-Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623-0841 and 0.7 hr for PSR J1839-0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

  17. Late rupture of the posterior cruciate ligament after total knee replacement.

    OpenAIRE

    Montgomery, R. L.; Goodman, S. B.; Csongradi, J.

    1993-01-01

    To our knowledge there have been no reports of late rupture of the posterior cruciate ligament (PCL) as a cause of instability in PCL-retaining total knee prostheses. In our experience of 150 total knee replacements using PCL-retaining prosthesis, three cases (2.0%) of late rupture of the posterior cruciate ligament have occurred, each leading to chronic instability, disabling pain, and revision arthroplasty. In each case rupture of the posterior cruciate ligament was confirmed at the time of...

  18. Light curve analysis of the late type binary V523 Cassiopeiae

    Directory of Open Access Journals (Sweden)

    Latković O.

    2009-01-01

    Full Text Available We present the analysis of V and R light curves of the late type contact binary V523 Cas for the season of 2006. These observations make part of the monitoring program aimed at studying the long-term light curve variability in this system. Our results confirm that the system is in an over contact configuration, and include a bright spot in the neck region of the cooler and larger primary. We compare these results with the previous solution, obtained for the season 2005 dataset and discuss the differences.

  19. Late Posthemorrhagic Structural and Functional Changes in Pulmonary Circulation Arteries

    Directory of Open Access Journals (Sweden)

    S. A. Andreyeva

    2008-01-01

    Full Text Available Objective: to reveal the major regularities and mechanisms of morphological changes in the rat pulmonary circulation arteries in the late posthemorrhagic period and to compare them with age-related features of the vessels. Materials and methods: experiments to generate graduated hemorrhagic hypotension with the blood pressure being maintained at 40 mm Hg were carried out on young (5—6-month albino male Wistar rats. Throughout hypotension and 60 days after blood loss, the blood was tested to determine low and average molecular-weight substances by spectrophotometry and the pro- and antioxidative systems by chemiluminescence. Pulmonary circulation arteries were morphologically studied in young animals, rats in the late posthemorrhagic period and old (24—25-month rats. Results. Sixty-minute hemorrhagic hypotension leads to the development of endotoxemia and imbalance of the pro- and antioxidative systems, the signs of which are observed in the late periods (2 months after hypotension. At the same time, the posthemorrhagic period is marked by the significant pulmonary circulation arterial morphological changes comparable with their age-related alterations in old rat. This shows up mainly in the reorganization of a connective tissue component in the vascular wall: the elevated levels of individual collagen fibers, their structural changes, elastic medial membrane destruction and deformity. At the same time, there is a change in the morphometric parameters of vessels at all study stages while their lowered flow capacity is only characteristic for intraorgan arteries. Conclusion: The increased activity of free radical oxidation and endotoxemia may be believed to be one of the causes of morphological changes in pulmonary circulation arteries in the late posthemorrhagic period, which is similar to age-related vascular alterations. Key words: hemorrhagic hypotension, pulmonary circulation arteries, free radical oxidation, endotoxemia, remodeling, late

  20. Multiple Long-Time Solutions for Intermediate Reynolds Number Flow past a Circular Cylinder with a Nonlinear Inertial and Dissipative Attachment

    Science.gov (United States)

    Blanchard, Antoine B. E.; Bergman, Lawrence A.; Vakakis, Alexander F.; Pearlstein, Arne J.

    2016-11-01

    We consider two-dimensional flow past a linearly-sprung cylinder allowed to undergo rectilinear motion normal to the mean flow, with an attached "nonlinear energy sink" consisting of a mass allowed to rotate about the cylinder axis, and whose rotational motion is linearly damped by a viscous damper. For Re fluid density, dimensionless damping coefficient, and ratio of the rotating mass to the total mass, we find that different inlet transients lead to different long-time solutions, including solutions that are steady and symmetric (with a motionless cylinder), time-periodic, quasi-periodic, and chaotic. The results show that over a wide range of the parameters, the steady symmetric motionless-cylinder solution is locally, but not globally, stable. Supported by NSF Grant CMMI-1363231.

  1. Dielectric dispersion, relaxation dynamics and thermodynamic studies of Beta-Alanine in aqueous solutions using picoseconds time domain reflectometry

    Science.gov (United States)

    Vinoth, K.; Ganesh, T.; Senthilkumar, P.; Sylvester, M. Maria; Karunakaran, D. J. S. Anand; Hudge, Praveen; Kumbharkhane, A. C.

    2017-09-01

    The aqueous solution of beta-alanine characterised and studied by their dispersive dielectric properties and relaxation process in the frequency domain of 10×106 Hz to 30×109 Hz with varying concentration in mole fractions and temperatures. The molecular interaction and dielectric parameters are discussed in terms of counter-ion concentration theory. The static permittivity (ε0), high frequency dielectric permittivity (ε∞) and excess dielectric parameters are accomplished by frequency depended physical properties and relaxation time (τ). Molecular orientation, ordering and correlation factors are reported as confirmation of intermolecular interactions. Ionic conductivity and thermo dynamical properties are concluded with the behaviour of the mixture constituents. Solute-solvent, solute-solute interaction, structure making and breaking abilities of the solute in aqueous medium are interpreted. Fourier Transform Infrared (FTIR) spectra of beta- alanine single crystal and liquid state have been studied. The 13C Nuclear Magnetic Resonance (NMR) spectral studies give the signature for resonating frequencies and chemical shifts of beta-alanine.

  2. Central-peripheral Temperature Monitoring as a Marker for Diagnosing Late-onset Neonatal Sepsis.

    Science.gov (United States)

    Leante-Castellanos, José Luis; Martínez-Gimeno, Antonio; Cidrás-Pidré, Manuel; Martínez-Munar, Gerardo; García-González, Ana; Fuentes-Gutiérrez, Carmen

    2017-12-01

    The prognosis for late-onset sepsis depends largely on a timely diagnosis. We assess central-peripheral temperature difference monitoring as a marker for late-onset neonatal sepsis diagnosis. We performed a prospective, observational study focusing on a cohort of 129 very low-birth-weight infants. Thermal gradient alteration was defined as a difference of > 2°C maintained during 4 hours. We then determined its association with the late-onset sepsis variable through logistic regression. We enrolled 129 preterm babies in 52 months. Thermal gradient alterations showed an adjusted odds ratio for late-onset sepsis of 23.60 (95% confidence interval [CI], 6.80-81.88), with a sensitivity of 83% and negative predictive value of 94%. In 71% of cases, thermal gradient alteration was the first clinical sign of sepsis, while C-reactive protein was peripheral temperature differences are an early sign of evolving late-onset sepsis.

  3. 1-Soliton solution of the generalized Zakharov-Kuznetsov equation with nonlinear dispersion and time-dependent coefficients

    International Nuclear Information System (INIS)

    Biswas, Anjan

    2009-01-01

    In this Letter, the 1-soliton solution of the Zakharov-Kuznetsov equation with power law nonlinearity and nonlinear dispersion along with time-dependent coefficients is obtained. There are two models for this kind of an equation that are studied. The constraint relation between these time-dependent coefficients is established for the solitons to exist. Subsequently, this equation is again analysed with generalized evolution. The solitary wave ansatz is used to carry out this investigation.

  4. Multiple periodic solutions for a discrete time model of plankton allelopathy

    OpenAIRE

    Zhang Jianbao; Fang Hui

    2006-01-01

    We study a discrete time model of the growth of two species of plankton with competitive and allelopathic effects on each other N1(k+1) = N1(k)exp{r1(k)-a11(k)N1(k)-a12(k)N2(k)-b1(k)N1(k)N2(k)}, N2(k+1) = N2(k)exp{r2(k)-a21(k)N2(k)-b2(k)N1(k)N1(k)N2(k)}. A set of sufficient conditions is obtained for the existence of multiple positive periodic solutions for this model. The approach is based on Mawhin's continuation theorem of coincidence degree theory as well as some a priori estimates. Some...

  5. A physical framework for evaluating net effects of wet meadow restoration on late summer streamflow

    Science.gov (United States)

    Grant, G.; Nash, C.; Selker, J. S.; Lewis, S.; Noël, P.

    2017-12-01

    Restoration of degraded wet meadows that develop on upland valley floors is intended to achieve a range of ecological benefits. A widely cited benefit is the potential for meadow restoration to augment late-season streamflow; however, there has been little field data demonstrating increased summer flows following restoration. Instead, the hydrologic consequences of restoration have typically been explored using coupled groundwater and surface water flow models at instrumented sites. The expected magnitude and direction of change provided by models has, however, been inconclusive. Here, we assess the streamflow benefit that can be obtained by wet meadow restoration using a parsimonious, physically-based approach. We use a one-dimensional linearized Boussinesq equation with a superimposed solution for changes in storage due to groundwater upwelling and and explicitly calculate evapotranspiration using the White Method. The model accurately predicts water table elevations from field data in the Middle Fork John Day watershed in Oregon, USA. The full solution shows that while raising channel beds can increase total water storage via increases in water table elevation in upland valley bottoms, the contributions of both lateral and longitudinal drainage from restored floodplains to late summer streamflow are undetectably small, while losses in streamflow due to greater transpiration, lower hydraulic gradients, and less drainable pore volume are substantial. Although late-summer streamflow increases should not be expected as a direct result of wet meadow restoration, these approaches offer benefits for improving the quality and health of riparian and meadow vegetation that would warrant considering such measures, even at the cost of increased water demand and reduced streamflow.

  6. Efficacy of brain scanning in epilepsy of late onset

    International Nuclear Information System (INIS)

    Jain, A.N.; Ramanathan, P.; Ganatra, R.D.

    1978-01-01

    Brain scans of 513 patients with epilepsy of late onset were analysed with reference to the patient's age and sex and to the nature of convulsion. Only 17 of them showed an abnormal concentration of radionuclide indicating a space-occupying lesion in the brain. The findings of those patients who had positive brain scans were correlated with EEG findings. It was found that the incidence of epilepsy of late onset is almost 3 times higher in males than in females and that the age cannot be considered as a criterion for screening the patients for brain scan investigation as far as epilepsy of late onset is concerned. In the authors' opinion, the incidence of 3.3% is not too low. A positive brain scan finding calls for further investigation and helps in deciding the management and further line of treatment of the patients. Moreover, a normal scan rules out the presence of a space-occupying lesion and helps as a screening procedure. (orig.) 891 MG [de

  7. Early versus Late Parenteral Nutrition in Critically Ill Children.

    Science.gov (United States)

    Fivez, Tom; Kerklaan, Dorian; Mesotten, Dieter; Verbruggen, Sascha; Wouters, Pieter J; Vanhorebeek, Ilse; Debaveye, Yves; Vlasselaers, Dirk; Desmet, Lars; Casaer, Michael P; Garcia Guerra, Gonzalo; Hanot, Jan; Joffe, Ari; Tibboel, Dick; Joosten, Koen; Van den Berghe, Greet

    2016-03-24

    Recent trials have questioned the benefit of early parenteral nutrition in adults. The effect of early parenteral nutrition on clinical outcomes in critically ill children is unclear. We conducted a multicenter, randomized, controlled trial involving 1440 critically ill children to investigate whether withholding parenteral nutrition for 1 week (i.e., providing late parenteral nutrition) in the pediatric intensive care unit (ICU) is clinically superior to providing early parenteral nutrition. Fluid loading was similar in the two groups. The two primary end points were new infection acquired during the ICU stay and the adjusted duration of ICU dependency, as assessed by the number of days in the ICU and as time to discharge alive from ICU. For the 723 patients receiving early parenteral nutrition, parenteral nutrition was initiated within 24 hours after ICU admission, whereas for the 717 patients receiving late parenteral nutrition, parenteral nutrition was not provided until the morning of the 8th day in the ICU. In both groups, enteral nutrition was attempted early and intravenous micronutrients were provided. Although mortality was similar in the two groups, the percentage of patients with a new infection was 10.7% in the group receiving late parenteral nutrition, as compared with 18.5% in the group receiving early parenteral nutrition (adjusted odds ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66). The mean (±SE) duration of ICU stay was 6.5±0.4 days in the group receiving late parenteral nutrition, as compared with 9.2±0.8 days in the group receiving early parenteral nutrition; there was also a higher likelihood of an earlier live discharge from the ICU at any time in the late-parenteral-nutrition group (adjusted hazard ratio, 1.23; 95% CI, 1.11 to 1.37). Late parenteral nutrition was associated with a shorter duration of mechanical ventilatory support than was early parenteral nutrition (P=0.001), as well as a smaller proportion of patients

  8. Clinical challenges late after correction of tetralogy of Fallot

    NARCIS (Netherlands)

    Bokma, J.P.

    2018-01-01

    This thesis focused on several clinical challenges which may occur late after surgical correction of tetralogy of Fallot. Among several other topics, three important clinical challenges were studied: (1) timing of pulmonary valve replacement, (2) risk stratification, (3) prevention and treatment of

  9. Elliptic and solitary wave solutions for Bogoyavlenskii equations system, couple Boiti-Leon-Pempinelli equations system and Time-fractional Cahn-Allen equation

    Directory of Open Access Journals (Sweden)

    Mostafa M.A. Khater

    Full Text Available In this article and for the first time, we introduce and describe Khater method which is a new technique for solving nonlinear partial differential equations (PDEs.. We apply this method for each of the following models Bogoyavlenskii equation, couple Boiti-Leon-Pempinelli system and Time-fractional Cahn-Allen equation. Khater method is very powerful, Effective, felicitous and fabulous method to get exact and solitary wave solution of (PDEs.. Not only just like that but it considers too one of the general methods for solving that kind of equations since it involves some methods as we will see in our discuss of the results. We make a comparison between the results of this new method and another method. Keywords: Bogoyavlenskii equations system, Couple Boiti-Leon-Pempinelli equations system, Time-fractional Cahn-Allen equation, Khater method, Traveling wave solutions, Solitary wave solutions

  10. Radiation dose and late failures in prostate cancer

    International Nuclear Information System (INIS)

    Morgan, Peter B.; Hanlon, Alexandra L.; Horwitz, Eric M.; Buyyounouski, Mark K.; Uzzo, Robert G.; Pollack, Alan

    2007-01-01

    Purpose: To quantify the impact of radiation dose escalation on the timing of biochemical failure (BF) and distant metastasis (DM) for prostate cancer treated with radiotherapy (RT) alone. Methods: The data from 667 men with clinically localized intermediate- and high-risk prostate cancer treated with three-dimensional conformal RT alone were retrospectively analyzed. The interval hazard rates of DM and BF, using the American Society for Therapeutic Radiology and Oncology (ASTRO) and Phoenix (nadir + 2) definitions, were determined. The median follow-up was 77 months. Results: Multivariate analysis showed that increasing radiation dose was independently associated with decreased ASTRO BF (p < 0.0001), nadir + 2 BF (p = 0.001), and DM (p = 0.006). The preponderance (85%) of ASTRO BF occurred at ≤4 years after RT, and nadir + 2 BF was more evenly spread throughout Years 1-10, with 55% of BF in ≤4 years. Radiation dose escalation caused a shift in the BF from earlier to later years. The interval hazard function for DM appeared to be biphasic (early and late peaks) overall and for the <74-Gy group. In patients receiving ≥74 Gy, a reduction occurred in the risk of DM in the early and late waves, although the late wave appeared reduced to a greater degree. Conclusion: The ASTRO definition of BF systematically underestimated late BF because of backdating. Radiation dose escalation diminished and delayed BF; the delay suggested that local persistence may still be present in some patients. For DM, a greater radiation dose reduced the early and late waves, suggesting that persistence of local disease contributed to both

  11. New convergence behavior of solutions to Cohen-Grossberg neural networks with delays and time-varying coefficients

    International Nuclear Information System (INIS)

    Liu Bingwen

    2008-01-01

    In this Letter the convergence behavior of Cohen-Grossberg neural networks with delays and time-varying coefficients are considered. Some sufficient conditions are established to ensure that the solutions of the networks converge locally exponentially to zero point, which are new and complement of previously known results

  12. Fluvial system response to Late Devensian (Weichselian) aridity, Baston, Lincolnshire, England

    Science.gov (United States)

    Briant, Rebecca M.; Coope, G. Russell; Preece, Richard C.; Keen, David H.; Boreham, Steve; Griffiths, Huw I.; Seddon, Mary B.; Gibbard, Philip L.

    2004-07-01

    Little is known about the impact of Late Devensian (Weichselian) aridity on lowland British landscapes, largely because they lack the widespread coversand deposits of the adjacent continent. The concentration of large interformational ice-wedge casts in the upper part of many Devensian fluvial sequences suggests that fluvial activity may have decreased considerably during this time. The development of optically stimulated luminescence (OSL) dating enables this period of ice-wedge cast formation to be constrained for the first time in eastern England, where a marked horizon of ice-wedge casts is found between two distinctive dateable facies associations. Contrasts between this horizon and adjacent sediments show clear changes in environment and fluvial system behaviour in response to changing water supply, in line with palaeontological evidence. In addition to providing chronological control on the period of ice-wedge formation, the study shows good agreement of the radiocarbon and OSL dating techniques during the Middle and Late Devensian, with direct comparison of these techniques beyond 15 000 yr for the first time in Britain. It is suggested that aridity during the Late Devensian forced a significant decrease in fluvial activity compared with preceding and following periods, initiating a system with low peak flows and widespread permafrost development. Copyright

  13. A COHERENT TIMING SOLUTION FOR THE NEARBY, THERMALLY EMITTING ISOLATED NEUTRON STAR RX J0420.0-5022

    International Nuclear Information System (INIS)

    Kaplan, D. L.; Van Kerkwijk, M. H.

    2011-01-01

    We present a phase-coherent timing solution for RX J0420.0-5022, the coolest (kT ≅ 45 eV) and fastest-spinning (P = 3.45 s) of the seven so-called isolated neutron stars (INSs). Using 14 observations with the XMM-Newton spacecraft in 2010 and 2011, we were able to measure a spin-down rate ν-dot = (-2.3 ± 0.2) x 10 15 Hz s -1 (P-dot =(2.8±0.3)x10 -14 s s -1 ), from which we infer a dipolar magnetic field of 1.0 x 10 13 G. With reasonable confidence we were able to extend the timing solution back to archival XMM-Newton from 2002 and 2003, giving the same solution but with considerably more precision. This gives RX J0420.0-5022 the lowest dipole magnetic field of the INSs. Our spectroscopy does not confirm the broad absorption feature at 0.3 keV hinted at in earlier observations, although difficulties in background subtraction near that energy make conclusions difficult. With this, all six of the INSs that have confirmed periodicities now have constrained spin-downs from coherent solutions. The evidence that the INSs are qualitatively different from rotation-powered pulsars now appears robust, with the likely conclusion that their characteristic ages are systematically older than their true ages, because their fields have decayed. The field decay probably also causes them to be systematically hotter than pulsars of the same (true) age.

  14. A time-domain decomposition iterative method for the solution of distributed linear quadratic optimal control problems

    Science.gov (United States)

    Heinkenschloss, Matthias

    2005-01-01

    We study a class of time-domain decomposition-based methods for the numerical solution of large-scale linear quadratic optimal control problems. Our methods are based on a multiple shooting reformulation of the linear quadratic optimal control problem as a discrete-time optimal control (DTOC) problem. The optimality conditions for this DTOC problem lead to a linear block tridiagonal system. The diagonal blocks are invertible and are related to the original linear quadratic optimal control problem restricted to smaller time-subintervals. This motivates the application of block Gauss-Seidel (GS)-type methods for the solution of the block tridiagonal systems. Numerical experiments show that the spectral radii of the block GS iteration matrices are larger than one for typical applications, but that the eigenvalues of the iteration matrices decay to zero fast. Hence, while the GS method is not expected to convergence for typical applications, it can be effective as a preconditioner for Krylov-subspace methods. This is confirmed by our numerical tests.A byproduct of this research is the insight that certain instantaneous control techniques can be viewed as the application of one step of the forward block GS method applied to the DTOC optimality system.

  15. Late effects of childhood leukemia therapy.

    Science.gov (United States)

    Fulbright, Joy M; Raman, Sripriya; McClellan, Wendy S; August, Keith J

    2011-09-01

    As survival rates for children treated for childhood cancers become significantly better, the focus is increasingly on determining the late effects of treatments and the best ways to monitor for them and prevent their occurrence. This review focuses on recent literature discussing the late effects of treatment in patients treated for acute myeloid leukemia and acute lymphoblastic leukemia during childhood. The late effects of therapy for childhood leukemia include secondary malignancy, cardiotoxicity, obesity, endocrine abnormalities, reproductive changes, neurocognitive deficits, and psychosocial effects. As clinicians have become more aware of the late effects of therapy, treatment regimens have been changed to decrease late effects, but patients still require long-term follow-up for their prevention and treatment.

  16. Solution of the linearised Vlasov equation for collisionless plasmas evolving in external fields of arbitrary spatial and time dependence: Pt. 2

    International Nuclear Information System (INIS)

    Skarka, V.; Coveney, P.V.

    1990-01-01

    We solve perturbatively the linearised Vlasov equation describing inhomogeneous collisionless plasmas evolving in time-dependent external fields. The method employs an explicitly time-dependent formalism and is facilitated by the used of diagrammatic techniques. It leads to a straightforward algorithm for computing the contribution to the solution, order by order in the external field. In the previous paper we provided the solution to first order; higher orders are described in the present paper. (author)

  17. So Close, yet So Far Away: Early vs. Late Dropouts

    Science.gov (United States)

    Ma, Yanli; Cragg, Kristina M.

    2013-01-01

    While some students drop out early in their academic career, others drop out close to completion. What similarities and differences exist between these early and late dropouts? Using a sample 3,520 first-time, full-time (FTFT) students seeking a bachelor's degree at a state university, this study employs multinomial logistic regression to model…

  18. Existence and global exponential stability of periodic solution of memristor-based BAM neural networks with time-varying delays.

    Science.gov (United States)

    Li, Hongfei; Jiang, Haijun; Hu, Cheng

    2016-03-01

    In this paper, we investigate a class of memristor-based BAM neural networks with time-varying delays. Under the framework of Filippov solutions, boundedness and ultimate boundedness of solutions of memristor-based BAM neural networks are guaranteed by Chain rule and inequalities technique. Moreover, a new method involving Yoshizawa-like theorem is favorably employed to acquire the existence of periodic solution. By applying the theory of set-valued maps and functional differential inclusions, an available Lyapunov functional and some new testable algebraic criteria are derived for ensuring the uniqueness and global exponential stability of periodic solution of memristor-based BAM neural networks. The obtained results expand and complement some previous work on memristor-based BAM neural networks. Finally, a numerical example is provided to show the applicability and effectiveness of our theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. The Iterative Solution to Discrete-Time H∞ Control Problems for Periodic Systems

    Directory of Open Access Journals (Sweden)

    Ivan G. Ivanov

    2016-03-01

    Full Text Available This paper addresses the problem of solving discrete-time H ∞ control problems for periodic systems. The approach for solving such a type of equations is well known in the literature. However, the focus of our research is set on the numerical computation of the stabilizing solution. In particular, two effective methods for practical realization of the known iterative processes are described. Furthermore, a new iterative approach is investigated and applied. On the basis of numerical experiments, we compare the presented methods. A major conclusion is that the new iterative approach is faster than rest of the methods and it uses less RAM memory than other methods.

  20. Photometry of long-period Algol binaries. VI. Multicolor photometric solutions for RZ Cancri

    Energy Technology Data Exchange (ETDEWEB)

    Olson, E.C. (Illinois Univ., Urbana (USA))

    1989-09-01

    New intermediate-band photometry of the late-giant eclipsing system RZ CNc is used to obtain photometric solutions, both with the Popper (1976) spectroscopic mass ratio and by allowing the mass ratio and gravity-darkening coefficients to vary. New y observations are combined with earlier V data of Lenouvel (1957) and Broglia and Conconi (1973) in one solution set. Additional solutions are obtained from the new observations. The mean photometric mass ratio is somewhat larger than Popper's spectroscopic values; the general indeterminacy of photometric solutions may explain this apparent discrepancy. Possible photometric effects of a mass-transferring stream are discussed, and it is concluded that such effects cannot account for the mass-ratio discrepancy. 26 refs.

  1. Photometry of long-period Algol binaries. VI. Multicolor photometric solutions for RZ Cancri

    International Nuclear Information System (INIS)

    Olson, E.C.

    1989-01-01

    New intermediate-band photometry of the late-giant eclipsing system RZ CNc is used to obtain photometric solutions, both with the Popper (1976) spectroscopic mass ratio and by allowing the mass ratio and gravity-darkening coefficients to vary. New y observations are combined with earlier V data of Lenouvel (1957) and Broglia and Conconi (1973) in one solution set. Additional solutions are obtained from the new observations. The mean photometric mass ratio is somewhat larger than Popper's spectroscopic values; the general indeterminacy of photometric solutions may explain this apparent discrepancy. Possible photometric effects of a mass-transferring stream are discussed, and it is concluded that such effects cannot account for the mass-ratio discrepancy. 26 refs

  2. Existence and global exponential stability of periodic solutions for n-dimensional neutral dynamic equations on time scales.

    Science.gov (United States)

    Li, Bing; Li, Yongkun; Zhang, Xuemei

    2016-01-01

    In this paper, by using the existence of the exponential dichotomy of linear dynamic equations on time scales and the theory of calculus on time scales, we study the existence and global exponential stability of periodic solutions for a class of n-dimensional neutral dynamic equations on time scales. We also present an example to illustrate the feasibility of our results. The results of this paper are completely new and complementary to the previously known results even in both the case of differential equations (time scale [Formula: see text]) and the case of difference equations (time scale [Formula: see text]).

  3. A new and inexpensive non-bit-for-bit solution reproducibility test based on time step convergence (TSC1.0)

    Science.gov (United States)

    Wan, Hui; Zhang, Kai; Rasch, Philip J.; Singh, Balwinder; Chen, Xingyuan; Edwards, Jim

    2017-02-01

    A test procedure is proposed for identifying numerically significant solution changes in evolution equations used in atmospheric models. The test issues a fail signal when any code modifications or computing environment changes lead to solution differences that exceed the known time step sensitivity of the reference model. Initial evidence is provided using the Community Atmosphere Model (CAM) version 5.3 that the proposed procedure can be used to distinguish rounding-level solution changes from impacts of compiler optimization or parameter perturbation, which are known to cause substantial differences in the simulated climate. The test is not exhaustive since it does not detect issues associated with diagnostic calculations that do not feedback to the model state variables. Nevertheless, it provides a practical and objective way to assess the significance of solution changes. The short simulation length implies low computational cost. The independence between ensemble members allows for parallel execution of all simulations, thus facilitating fast turnaround. The new method is simple to implement since it does not require any code modifications. We expect that the same methodology can be used for any geophysical model to which the concept of time step convergence is applicable.

  4. Asymptotic behaviors of solutions for viscoelastic wave equation with space-time dependent damping term

    KAUST Repository

    Said-Houari, Belkacem

    2012-03-01

    In this paper, we consider a viscoelastic wave equation with an absorbing term and space-time dependent damping term. Based on the weighted energy method, and by assuming that the kernel decaying exponentially, we obtain the L2 decay rates of the solutions. More precisely, we show that the decay rates are the same as those obtained in Lin et al. (2010) [15] for the semilinear wave equation with absorption term. © 2011 Elsevier Inc.

  5. Asymptotic behaviors of solutions for viscoelastic wave equation with space-time dependent damping term

    KAUST Repository

    Said-Houari, Belkacem

    2012-01-01

    In this paper, we consider a viscoelastic wave equation with an absorbing term and space-time dependent damping term. Based on the weighted energy method, and by assuming that the kernel decaying exponentially, we obtain the L2 decay rates of the solutions. More precisely, we show that the decay rates are the same as those obtained in Lin et al. (2010) [15] for the semilinear wave equation with absorption term. © 2011 Elsevier Inc.

  6. Unmatched Case-Control Study on Late Presentation of HIV Infection in Santiago, Cape Verde (2004–2011)

    Science.gov (United States)

    Moreira, António L.; Fronteira, Inês; Augusto, Gonçalo Figueiredo; Martins, Maria Rosario O.

    2016-01-01

    Access to free antiretroviral therapy (ART) in Sub-Saharan Africa has been steadily increasing over the past decade. However, the success of large-scale ART programmes depends on timely diagnosis and early initiation of HIV care. This study characterizes late presenters to HIV care in Santiago (Cape Verde) between 2004 and 2011, and identifies factors associated with late presentation for care. We defined late presentation as persons presenting to HIV care with a CD4 count below 350 cells/mm3. An unmatched case-control study was conducted using socio-demographic and behavioural data of 368 individuals (191 cases and 177 controls) collected through an interviewer-administered questionnaire, comparing HIV patients late and early presented to care. Logistic regression was performed to estimate odds ratio and 95% confidence intervals. Results show that 51.9% were late presenters for HIV. No differences were found in gender distribution, marital status, or access to health services between cases and controls. Participants who undertook an HIV test by doctor indication were more likely to present late compared with those who tested for HIV by their own initiative. Also, individuals taking less time to initiate ART are more likely to present late. This study highlights the need to better understand reasons for late presentation to HIV care in Cape Verde. People in older age groups should be targeted in future approaches focused on late presenters to HIV care. PMID:26999167

  7. Late-type components of slow novae and symbiotic stars

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D A [Anglo-Australian Observatory, Epping (Australia); Royal Observatory, Edinburgh (UK))

    1980-08-01

    It is argued that the various types of symbiotic stars and the slow novae are the same phenomena exhibiting a range of associated time-scales, the slow novae being of intermediate speed. Evidence is summarized showing that both types of object contain normal M giants or mira variables. This fact is at odds with currently fashionable single-star models for slow novae, according to which the M star is totally disrupted before the outburst. Spectral types of the late-type components are presented for nearly 80 symbiotic stars and slow novae, derived from 2 ..mu..m spectroscopy. It is found that both the intensity of the emission spectrum and the electron density of the gas are functions of the spectral type of the late-type star. Explanations for these correlations are given. On the assumption that the late-type components are normal giants, spectroscopic parallaxes are determined; credible distances are derived which indicate that the known symbiotic stars have been sampled as far afield as the Galactic Centre. Hydrogen shell flashes on a white dwarf accreting gas from the late-type components offer an attractive explanation of the phenomena of slow novae and symbiotic stars, and such models are discussed in the concluding section.

  8. Late effects of various dose-fractionation regimens

    International Nuclear Information System (INIS)

    Turesson, I.; Notter, G.

    1983-01-01

    These clinical investigations of various dose-fractionation regimens on human skin show that: The late reactions cannot be predicted from the early reactions; The dose-response curves for late reactions are much steeper than for early reactions; Equivalent doses for various fractionation schedules concerning late effects can be calculated by means of a corrected CRE (NSD) formula; the correction must be considered preliminary because further follow-up is needed. A clinical fractionation study of this type requires: Extremely careful dosimetry; Study of the same anatomical region; Very long follow-up; Studies at different effect levels; Skin reaction is the only end point we have studied systematically for different fractionation regimens. Experience with the CRE formula as a model for calculating isoeffect doses for different fractionation schedules in routine clinical use can be summarized as follows: The CRE formula has been used prospectively since 1972 in all patients; CRE-equivalent weekly doses to 5 x 2.0 Gy per week has been used. (Although the fractionation schedule is changed, the overall treatment time is still the same); The CRE range was 18 to 21 for curative radiotherapy on carcinomas; No irradiation was applied during pronounced acute reactions. No unexpected complications have been observed under these conditions

  9. Analytical Solution of the Hyperbolic Heat Conduction Equation for Moving Semi-Infinite Medium under the Effect of Time-Dependent Laser Heat Source

    Directory of Open Access Journals (Sweden)

    R. T. Al-Khairy

    2009-01-01

    source, whose capacity is given by (,=((1−− while the semi-infinite body has insulated boundary. The solution is obtained by Laplace transforms method, and the discussion of solutions for different time characteristics of heat sources capacity (constant, instantaneous, and exponential is presented. The effect of absorption coefficients on the temperature profiles is examined in detail. It is found that the closed form solution derived from the present study reduces to the previously obtained analytical solution when the medium velocity is set to zero in the closed form solution.

  10. Late Toxicity After Definitive Concurrent Chemoradiotherapy for Thoracic Esophageal Carcinoma

    International Nuclear Information System (INIS)

    Morota, Madoka; Gomi, Kotaro; Kozuka, Takuyo; Chin, Keisho; Matsuura, Masaaki; Oguchi, Masahiko; Ito, Hisao; Yamashita, Takashi

    2009-01-01

    Purpose: To evaluate late cardiopulmonary toxicities after concurrent chemoradiotherapy (CCRT) for esophageal carcinomas. Methods and Materials: From February 2002 through April 2005, 74 patients with clinical Stage I-IVB carcinoma of the esophagus were treated with CCRT. Sixty-nine patients with thoracic squamous cell carcinoma were the core of this analysis. Patients received 60 Gy of radiation therapy in 30 fractions over 8 weeks, including a 2-week break, and received 2 cycles of fluorouracil/cisplatin chemotherapy concomitantly. Initial radiation fields included primary tumors, metastatic lymph nodes, and supraclavicular, mediastinal, and celiac nodes areas. Late toxicities were assessed with the late radiation morbidity scoring scheme of the Radiation Therapy Oncology Group/European Organiation for Research and Treatment of Cancer. Results: The median age was 67 years (range, 45-83 years). The median follow-up time was 26.1 months for all patients and 51.4 months for patients still alive at the time of analysis. Five cardiopulmonary toxic events of Grade 3 or greater were observed in 4 patients, Grade 5 heart failure and Grade 3 pericarditis in 1 patient, and Grade 3 myocardial infarction, Grade 3 radiation pneumonitis, and Grade 3 pleural effusion. The 2-year cumulative incidence of late cardiopulmonary toxicities of Grade 3 or greater for patients 75 years or older was 29% compared with 3% for younger patients (p = 0.005). Conclusion: The CCRT used in this study with an extensive radiation field is acceptable for younger patients but is not tolerated by patients older than 75 years.

  11. Lie symmetry analysis, conservation laws and exact solutions of the seventh-order time fractional Sawada–Kotera–Ito equation

    Directory of Open Access Journals (Sweden)

    Emrullah Yaşar

    Full Text Available In this paper Lie symmetry analysis of the seventh-order time fractional Sawada–Kotera–Ito (FSKI equation with Riemann–Liouville derivative is performed. Using the Lie point symmetries of FSKI equation, it is shown that it can be transformed into a nonlinear ordinary differential equation of fractional order with a new dependent variable. In the reduced equation the derivative is in Erdelyi–Kober sense. Furthermore, adapting the Ibragimov’s nonlocal conservation method to time fractional partial differential equations, we obtain conservation laws of the underlying equation. In addition, we construct some exact travelling wave solutions for the FSKI equation using the sub-equation method. Keywords: Fractional Sawada–Kotera–Ito equation, Lie symmetry, Riemann–Liouville fractional derivative, Conservation laws, Exact solutions

  12. A software solution for recording circadian oscillator features in time-lapse live cell microscopy.

    Science.gov (United States)

    Sage, Daniel; Unser, Michael; Salmon, Patrick; Dibner, Charna

    2010-07-06

    Fluorescent and bioluminescent time-lapse microscopy approaches have been successfully used to investigate molecular mechanisms underlying the mammalian circadian oscillator at the single cell level. However, most of the available software and common methods based on intensity-threshold segmentation and frame-to-frame tracking are not applicable in these experiments. This is due to cell movement and dramatic changes in the fluorescent/bioluminescent reporter protein during the circadian cycle, with the lowest expression level very close to the background intensity. At present, the standard approach to analyze data sets obtained from time lapse microscopy is either manual tracking or application of generic image-processing software/dedicated tracking software. To our knowledge, these existing software solutions for manual and automatic tracking have strong limitations in tracking individual cells if their plane shifts. In an attempt to improve existing methodology of time-lapse tracking of a large number of moving cells, we have developed a semi-automatic software package. It extracts the trajectory of the cells by tracking theirs displacements, makes the delineation of cell nucleus or whole cell, and finally yields measurements of various features, like reporter protein expression level or cell displacement. As an example, we present here single cell circadian pattern and motility analysis of NIH3T3 mouse fibroblasts expressing a fluorescent circadian reporter protein. Using Circadian Gene Express plugin, we performed fast and nonbiased analysis of large fluorescent time lapse microscopy datasets. Our software solution, Circadian Gene Express (CGE), is easy to use and allows precise and semi-automatic tracking of moving cells over longer period of time. In spite of significant circadian variations in protein expression with extremely low expression levels at the valley phase, CGE allows accurate and efficient recording of large number of cell parameters, including

  13. Existence, regularity and representation of solutions of time fractional wave equations

    Directory of Open Access Journals (Sweden)

    Valentin Keyantuo

    2017-09-01

    Full Text Available We study the solvability of the fractional order inhomogeneous Cauchy problem $$ \\mathbb{D}_t^\\alpha u(t=Au(t+f(t, \\quad t>0,\\;1<\\alpha\\le 2, $$ where A is a closed linear operator in some Banach space X and $f:[0,\\infty\\to X$ a given function. Operator families associated with this problem are defined and their regularity properties are investigated. In the case where A is a generator of a $\\beta$-times integrated cosine family $(C_\\beta(t$, we derive explicit representations of mild and classical solutions of the above problem in terms of the integrated cosine family. We include applications to elliptic operators with Dirichlet, Neumann or Robin type boundary conditions on $L^p$-spaces and on the space of continuous functions.

  14. LISA time-delay interferometry zero-signal solution: Geometrical properties

    International Nuclear Information System (INIS)

    Tinto, Massimo; Larson, Shane L.

    2004-01-01

    Time-delay interferometry (TDI) is the data processing technique needed for generating interferometric combinations of data measured by the multiple Doppler readouts available onboard the three Laser Interferometer Space Antenna (LISA) spacecraft. Within the space of all possible interferometric combinations TDI can generate, we have derived a specific combination that has zero response to the gravitational wave signal, and called it the zero-signal solution (ZSS). This is a two-parameter family of linear combinations of the generators of the TDI space, and its response to a gravitational wave becomes null when these two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the ZSS does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind. Our approach is analogous to the data analysis method introduced by Guersel and Tinto in the context of networks of Earth-based, wideband, interferometric gravitational wave detectors observing in coincidence a gravitational wave burst. The ZSS should be regarded as an application of the Guersel and Tinto method to the LISA data

  15. Consequential late radiation damage in the skin in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Li Wei; Kong Ling; Zhang Youwang; Hu Chaosu; Wu Yongru

    2008-01-01

    Objective: To evaluate the relationship between early and late radiation damage in skin. Methods: 335 patients with nasopharyngeal carcinoma treated with radical radiotherapy were evaluated. 240 patients had lymph nodes in the neck at initial diagnosis. The median doses were 70 Gy (55-86 Gy) to the nasopharyngeal region by external beam radiotherapy. The median doses were 64 Gy (46-72 Gy) to the neck with lymph node metastases, 55 Gy (21-67 Gy) to the node-negative neck. 71 patients were treated with facial-neck fields, while 264 patients were treated with pre-auricular fields. Chemotherapy was given in 48 patients. According to the 1995 SOMA scales late radiation damage in the skin was evaluated. Results: The median time from the radiotherapy to follow up was 14 years (range, 5-38 years). 63 patients have grade 0 late radiation reactions in the neck skin, the grade 1,2, 3,4 late radiation reactions in the neck skin were 43.9% (147 patients), 20.9% (70 patients), 13.7% (46 patients) and 2.7% (9 patients), respectively. 44 patients had moist desquamation in the medical records. The grade 1,2,3,4 late radiation reactions in the neck skin were 41%, 23%, 30% and 5%, respectively in patients with moist desquamation, while in patients without moist desquamation, the corresponding rates were 44.3%, 20.6%, 11.3% and 2.4%, respectively. The difference were significant between these two groups by chi-square analysis(χ 2 =17.42, P=0.002). Furthermore, whether patients had positive lymph node in the neck or not, the size of facial-neck fields and higher doses to the neck had more severe late radiation reaction in the neck skin, while age, gender and chemotherapy failed to show any effects on the development of late radiation reactions in the neck skin. Conclusion: The severe early radiation damage in the skin possibly increases the late radiation damage in the neck skin. (authors)

  16. Late-onset systemic lupus erythematosus in Latin Americans: a distinct subgroup?

    Science.gov (United States)

    Catoggio, L J; Soriano, E R; Imamura, P M; Wojdyla, D; Jacobelli, S; Massardo, L; Chacón Díaz, R; Guibert-Toledano, M; Alvarellos, A; Saurit, V; Manni, J A; Pascual-Ramos, V; Silva de Sauza, A W; Bonfa, E; Tavares Brenol, J C; Ramirez, L A; Barile-Fabris, L A; De La Torre, I Garcia; Alarcón, G S; Pons-Estel, B A

    2015-07-01

    To examine the characteristics of patients who developed late onset systemic lupus erythematosus (SLE) in the GLADEL (Grupo Latino Americano de Estudio del Lupus) cohort of patients with SLE. Patients with SLE of less than two years of disease duration, seen at 34 centers of nine Latin American countries, were included. Late-onset was defined as >50 years of age at time of first SLE-related symptom. Clinical and laboratory manifestations, activity index (SLEDAI), and damage index (SLICC/ACR- DI) were ascertained at time of entry and during the course (cumulative incidence). Features were compared between the two patient groups (lupus, adjusting for other variables. Of the 1480 patients included, 102 patients (6.9 %) had late-onset SLE, 87% of which were female. Patients with late-onset SLE had a shorter follow-up (3.6 vs. 4.4 years, p  0.05). In multivariable analysis, late onset was independently associated with higher odds of ocular (OR = 3.66, 95% CI = 2.15-6.23), pulmonary (OR = 2.04, 95% CI = 1.01-4.11), and cardiovascular (OR = 1.76, 95% CI = 1.04-2.98) involvement and lower odds of cutaneous involvement (OR = 0.41, 95% CI = 0.21-0.80), number of cumulative SLE criteria (OR = 0.79, 95% CI = 0.64-0.97), use of cyclophosphamide (OR = 0.47, 95% CI = 0.24-0.95), and anti-RNP antibodies (OR = 0.43, 95% CI = 0.20-0.91). A Cox regression model revealed a higher risk of dying in older onset than the younger-onset SLE (OR = 2.61, 95% CI = 1.2-5.6). Late-onset SLE in Latin Americans had a distinct disease expression compared to the younger-onset group. The disease seems to be mild with lower cumulative SLE criteria, reduced renal/mucocutaneous involvements, and less use of cyclophosphamide. Nevertheless, these patients have a higher risk of death and of ocular, pulmonary, and cardiovascular involvements. © The Author(s) 2014.

  17. A solution for measuring accurate reaction time to visual stimuli realized with a programmable microcontroller.

    Science.gov (United States)

    Ohyanagi, Toshio; Sengoku, Yasuhito

    2010-02-01

    This article presents a new solution for measuring accurate reaction time (SMART) to visual stimuli. The SMART is a USB device realized with a Cypress Programmable System-on-Chip (PSoC) mixed-signal array programmable microcontroller. A brief overview of the hardware and firmware of the PSoC is provided, together with the results of three experiments. In Experiment 1, we investigated the timing accuracy of the SMART in measuring reaction time (RT) under different conditions of operating systems (OSs; Windows XP or Vista) and monitor displays (a CRT or an LCD). The results indicated that the timing error in measuring RT by the SMART was less than 2 msec, on average, under all combinations of OS and display and that the SMART was tolerant to jitter and noise. In Experiment 2, we tested the SMART with 8 participants. The results indicated that there was no significant difference among RTs obtained with the SMART under the different conditions of OS and display. In Experiment 3, we used Microsoft (MS) PowerPoint to present visual stimuli on the display. We found no significant difference in RTs obtained using MS DirectX technology versus using the PowerPoint file with the SMART. We are certain that the SMART is a simple and practical solution for measuring RTs accurately. Although there are some restrictions in using the SMART with RT paradigms, the SMART is capable of providing both researchers and health professionals working in clinical settings with new ways of using RT paradigms in their work.

  18. The epidemiology of acne vulgaris in late adolescence.

    Science.gov (United States)

    Lynn, Darren D; Umari, Tamara; Dunnick, Cory A; Dellavalle, Robert P

    2016-01-01

    Acne vulgaris is the most common skin condition affecting late adolescents across the globe. Although prior studies have evaluated epidemiologic patterns of acne vulgaris in various ethnicities and regions, adequate understanding of the worldwide burden of the disease associated with patients in their late adolescence (15-19-year olds) remains lacking. To assess the global burden of the disease associated with acne vulgaris for late adolescents (15-19-year olds) and provide an overview of the epidemiology, pathophysiology, and treatment options for acne in this population. Database summary study. Global Burden of Disease Study 2010 database. Global Burden of Disease regions comprised countries with prevalence of acne vulgaris between the ages of 15 and 19 years. Geographic region-level disability-adjusted life year rates (per 100,000 persons) associated with acne vulgaris in years 1990 through 2010. Median percentage change in disability-adjusted life year rates was estimated for each region across the specified study period. Acne vulgaris-associated disease burden exhibits global distribution and has continued to grow in prevalence over time within this population. This continued growth suggests an unmet dermatologic need worldwide for this disorder and potential opportunities for improved access and delivery of dermatologic care. Our analysis of the literature reveals numerous opportunities for enhanced patient care. To that end, we highlight some of the effective and promising treatments currently available and address important factors, such as sex, nationality, genetics, pathophysiology, and diet, as they relate to acne vulgaris in late adolescence.

  19. Impact of fungicide applications for late blight management on ...

    African Journals Online (AJOL)

    The influence of late blight infections, caused by Phytophthora infestans, was evaluated on thirteen huckleberry (Solanum scabrum) varieties during the 2000 and 2001 cropping seasons in Dschang, Cameroon. A randomised split block design was used. Plants were sprayed four times with Ridomil Plus® (12% metalaxyl + ...

  20. Solution Structural Studies of GTP:Adenosylcobinamide-Phosphateguanylyl Transferase (CobY from Methanocaldococcus jannaschii.

    Directory of Open Access Journals (Sweden)

    Kiran K Singarapu

    Full Text Available GTP:adenosylcobinamide-phosphate (AdoCbi-P guanylyl transferase (CobY is an enzyme that transfers the GMP moiety of GTP to AdoCbi yielding AdoCbi-GDP in the late steps of the assembly of Ado-cobamides in archaea. The failure of repeated attempts to crystallize ligand-free (apo CobY prompted us to explore its 3D structure by solution NMR spectroscopy. As reported here, the solution structure has a mixed α/β fold consisting of seven β-strands and five α-helices, which is very similar to a Rossmann fold. Titration of apo-CobY with GTP resulted in large changes in amide proton chemical shifts that indicated major structural perturbations upon complex formation. However, the CobY:GTP complex as followed by 1H-15N HSQC spectra was found to be unstable over time: GTP hydrolyzed and the protein converted slowly to a species with an NMR spectrum similar to that of apo-CobY. The variant CobYG153D, whose GTP complex was studied by X-ray crystallography, yielded NMR spectra similar to those of wild-type CobY in both its apo- state and in complex with GTP. The CobYG153D:GTP complex was also found to be unstable over time.

  1. Impact of meander geometry and stream flow events on residence times and solute transport in the intra-meander flow

    Science.gov (United States)

    Nasir Mahmood, Muhammad; Schmidt, Christian; Trauth, Nico

    2017-04-01

    Stream morphological features, in combination with hydrological variability play a key role in water and solute exchange across surface and subsurface waters. Meanders are prominent morphological features within stream systems which exhibit unique hydrodynamics. The water surface elevation difference across the inner bank of a meander induces lateral hyporheic exchange within the intra-meander region. This hyporheic flow is characterized by considerably prolonged flow paths and residence times (RT) compared to smaller scales of hyporheic exchange. In this study we examine the impact of different meander geometries on the intra-meander hyporheic flow field and solute mobilization under both steady state and transient flow conditions. We developed a number of artificial meander shape scenarios, representing various meander evolution stages, ranging from a typical initial to advanced stage (near cut off ) meander. Three dimensional steady state numerical groundwater flow simulations including the unsaturated zone were performed for the intra-meander region. The meandering stream was implemented in the model by adjusting the top layers of the modelling domain to the streambed elevation and assigning linearly decreasing head boundary conditions to the streambed cells. Residence times for the intra-meander region were computed by advective particle tracking across the inner bank of meander. Selected steady state cases were extended to transient flow simulations to evaluate the impact of stream discharge events on the temporal behavior of the water exchange and solute transport in the intra-meander region. The transient stream discharge was simulated for a number of discharge events of variable duration and peak height using the surface water model HEC-RAS. Transient hydraulic heads obtained from the surface water model were applied as transient head boundary conditions to the streambed cells of the groundwater model. A solute concentration source was added in the

  2. Geodesics of electrically and magnetically charged test particles in the Reissner-Nordstroem space-time: Analytical solutions

    International Nuclear Information System (INIS)

    Grunau, Saskia; Kagramanova, Valeria

    2011-01-01

    We present the full set of analytical solutions of the geodesic equations of charged test particles in the Reissner-Nordstroem space-time in terms of the Weierstrass weierp, σ, and ζ elliptic functions. Based on the study of the polynomials in the θ and r equations, we characterize the motion of test particles and discuss their properties. The motion of charged test particles in the Reissner-Nordstroem space-time is compared with the motion of neutral test particles in the field of a gravitomagnetic monopole. Electrically or magnetically charged particles in the Reissner-Nordstroem space-time with magnetic or electric charges, respectively, move on cones similar to neutral test particles in the Taub-NUT space-times.

  3. Non-existence of time-periodic solutions of the Dirac equation in a Reissner-Nordström black hole background

    Science.gov (United States)

    Finster, Felix; Smoller, Joel; Yau, Shing-Tung

    2000-04-01

    It is shown analytically that the Dirac equation has no normalizable, time-periodic solutions in a Reissner-Nordström black hole background; in particular, there are no static solutions of the Dirac equation in such a background metric. The physical interpretation is that Dirac particles can either disappear into the black hole or escape to infinity, but they cannot stay on a periodic orbit around the black hole.

  4. Coping – Late Side Effects

    Science.gov (United States)

    Cancer treatment can cause late side effects that may not show up for months or years after treatment. These late effects may include heart and lung problems, bone loss, eye and hearing changes, lymphedema, and other problems

  5. A Green's function method for simulation of time-dependent solute transport and reaction in realistic microvascular geometries.

    Science.gov (United States)

    Secomb, Timothy W

    2016-12-01

    A novel theoretical method is presented for simulating the spatially resolved convective and diffusive transport of reacting solutes between microvascular networks and the surrounding tissues. The method allows for efficient computational solution of problems involving convection and non-linear binding of solutes in blood flowing through microvascular networks with realistic 3D geometries, coupled with transvascular exchange and diffusion and reaction in the surrounding tissue space. The method is based on a Green's function approach, in which the solute concentration distribution in the tissue is expressed as a sum of fields generated by time-varying distributions of discrete sources and sinks. As an example of the application of the method, the washout of an inert diffusible tracer substance from a tissue region perfused by a network of microvessels is simulated, showing its dependence on the solute's transvascular permeability and tissue diffusivity. Exponential decay of the washout concentration is predicted, with rate constants that are about 10-30% lower than the rate constants for a tissue cylinder model with the same vessel length, vessel surface area and blood flow rate per tissue volume. © The authors 2015. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  6. Implementing Run-Time Evaluation of Distributed Timing Constraints in a Real-Time Environment

    DEFF Research Database (Denmark)

    Kristensen, C. H.; Drejer, N.

    1994-01-01

    In this paper we describe a solution to the problem of implementing run-time evaluation of timing constraints in distributed real-time environments......In this paper we describe a solution to the problem of implementing run-time evaluation of timing constraints in distributed real-time environments...

  7. Contribution of Socioeconomic Status at 3 Life-Course Periods to Late-Life Memory Function and Decline: Early and Late Predictors of Dementia Risk.

    Science.gov (United States)

    Marden, Jessica R; Tchetgen Tchetgen, Eric J; Kawachi, Ichiro; Glymour, M Maria

    2017-10-01

    Both early life and adult socioeconomic status (SES) predict late-life level of memory; however, evidence is mixed on the relationship between SES and rate of memory decline. Further, the relative importance of different life-course periods for rate of late-life memory decline has not been evaluated. We examined associations between life-course SES and late-life memory function and decline. Health and Retirement Study participants (n = 10,781) were interviewed biennially from 1998-2012 (United States). SES measurements for childhood (composite score including parents' educational attainment), early adulthood (high-school or college completion), and older adulthood (income, mean age 66 years) were all dichotomized. Word-list memory was modeled via inverse-probability weighted longitudinal models accounting for differential attrition, survival, and time-varying confounding, with nonrespondents retained via proxy assessments. Compared to low SES at all 3 points (referent), stable, high SES predicted the best memory function and slowest decline. High-school completion had the largest estimated effect on memory (β = 0.19; 95% confidence interval: 0.15, 0.22), but high late-life income had the largest estimated benefit for slowing declines (for 10-year memory change, β = 0.35; 95% confidence interval: 0.24, 0.46). Both early and late-life interventions are potentially relevant for reducing dementia risk by improving memory function or slowing decline. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. An “Airy gun”: Self-accelerating solutions of the time-dependent Schrödinger equation in vacuum

    International Nuclear Information System (INIS)

    Mahalov, Alex; Suslov, Sergei K.

    2012-01-01

    We consider generalizations of the Berry and Balazs nonspreading and accelerating solution of the time-dependent Schrödinger equation in empty space, which has been experimentally demonstrated in paraxial optics. In particular, we show that the original nonspreading wave packet is unstable. An explicit variation of the initial Airy-state evolves into the self-accelerating and self-compressing solution presented here. Quasi-diffraction-free finite energy Airy beams that are more realistic for experimental study are obtained by analytic continuation and their Wigner function is evaluated. Nonlinear generalizations related to second Painlevé transcendents are briefly discussed.

  9. Late time acceleration of the 3-space in a higher dimensional steady state universe in dilaton gravity

    International Nuclear Information System (INIS)

    Akarsu, Özgür; Dereli, Tekin

    2013-01-01

    We present cosmological solutions for (1+3+n)-dimensional steady state universe in dilaton gravity with an arbitrary dilaton coupling constant w and exponential dilaton self-interaction potentials in the string frame. We focus particularly on the class in which the 3-space expands with a time varying deceleration parameter. We discuss the number of the internal dimensions and the value of the dilaton coupling constant to determine the cases that are consistent with the observed universe and the primordial nucleosynthesis. The 3-space starts with a decelerated expansion rate and evolves into accelerated expansion phase subject to the values of w and n, but ends with a Big Rip in all cases. We discuss the cosmological evolution in further detail for the cases w = 1 and w = ½ that permit exact solutions. We also comment on how the universe would be conceived by an observer in four dimensions who is unaware of the internal dimensions and thinks that the conventional general relativity is valid at cosmological scales

  10. Late time acceleration of the 3-space in a higher dimensional steady state universe in dilaton gravity

    Science.gov (United States)

    Akarsu, Özgür; Dereli, Tekin

    2013-02-01

    We present cosmological solutions for (1+3+n)-dimensional steady state universe in dilaton gravity with an arbitrary dilaton coupling constant w and exponential dilaton self-interaction potentials in the string frame. We focus particularly on the class in which the 3-space expands with a time varying deceleration parameter. We discuss the number of the internal dimensions and the value of the dilaton coupling constant to determine the cases that are consistent with the observed universe and the primordial nucleosynthesis. The 3-space starts with a decelerated expansion rate and evolves into accelerated expansion phase subject to the values of w and n, but ends with a Big Rip in all cases. We discuss the cosmological evolution in further detail for the cases w = 1 and w = ½ that permit exact solutions. We also comment on how the universe would be conceived by an observer in four dimensions who is unaware of the internal dimensions and thinks that the conventional general relativity is valid at cosmological scales.

  11. Practical Solutions for Reducing Container Ships’ Waiting Times at Ports Using Simulation Model

    Institute of Scientific and Technical Information of China (English)

    Abdorreza Sheikholeslami; Gholamreza Ilati; Yones Eftekhari Yeganeh

    2013-01-01

    The main challenge for container ports is the planning required for berthing container ships while docked in port. Growth of containerization is creating problems for ports and container terminals as they reach their capacity limits of various resources which increasingly leads to traffic and port congestion. Good planning and management of container terminal operations reduces waiting time for liner ships. Reducing the waiting time improves the terminal’s productivity and decreases the port difficulties. Two important keys to reducing waiting time with berth allocation are determining suitable access channel depths and increasing the number of berths which in this paper are studied and analyzed as practical solutions. Simulation based analysis is the only way to understand how various resources interact with each other and how they are affected in the berthing time of ships. We used the Enterprise Dynamics software to produce simulation models due to the complexity and nature of the problems. We further present case study for berth allocation simulation of the biggest container terminal in Iran and the optimum access channel depth and the number of berths are obtained from simulation results. The results show a significant reduction in the waiting time for container ships and can be useful for major functions in operations and development of container ship terminals.

  12. Calibration of the Late Cretaceous to Paleocene geomagnetic polarity and astrochronological time scales: new results from high-precision U-Pb geochronology

    Science.gov (United States)

    Ramezani, Jahandar; Clyde, William; Wang, Tiantian; Johnson, Kirk; Bowring, Samuel

    2016-04-01

    Reversals in the Earth's magnetic polarity are geologically abrupt events of global magnitude that makes them ideal timelines for stratigraphic correlation across a variety of depositional environments, especially where diagnostic marine fossils are absent. Accurate and precise calibration of the Geomagnetic Polarity Timescale (GPTS) is thus essential to the reconstruction of Earth history and to resolving the mode and tempo of biotic and environmental change in deep time. The Late Cretaceous - Paleocene GPTS is of particular interest as it encompasses a critical period of Earth history marked by the Cretaceous greenhouse climate, the peak of dinosaur diversity, the end-Cretaceous mass extinction and its paleoecological aftermaths. Absolute calibration of the GPTS has been traditionally based on sea-floor spreading magnetic anomaly profiles combined with local magnetostratigraphic sequences for which a numerical age model could be established by interpolation between an often limited number of 40Ar/39Ar dates from intercalated volcanic ash deposits. Although the Neogene part of the GPTS has been adequately calibrated using cyclostratigraphy-based, astrochronological schemes, the application of these approaches to pre-Neogene parts of the timescale has been complicated given the uncertainties of the orbital models and the chaotic behavior of the solar system this far back in time. Here we present refined chronostratigraphic frameworks based on high-precision U-Pb geochronology of ash beds from the Western Interior Basin of North America and the Songliao Basin of Northeast China that places tight temporal constraints on the Late Cretaceous to Paleocene GPTS, either directly or by testing their astrochronological underpinnings. Further application of high-precision radioisotope geochronology and calibrated astrochronology promises a complete and robust Cretaceous-Paleogene GPTS, entirely independent of sea-floor magnetic anomaly profiles.

  13. Latent-time estimation for late cutaneous and subcutaneous radiation reactions in a single-follow-up clinical study

    International Nuclear Information System (INIS)

    Thames, H.D.; Bentzen, S.M.; Overgaard, M.; Danish Cancer Society, Aarhus

    1989-01-01

    In this paper, an analysis of the fractionation sensitivity and latency of subcutaneous fibrosis and telangiectasia in a clinical series is presented. The series comprised 163 breast cancer patients who, from 1978 to 1980, received postmastectomy irradiation delivered in 12 fractions, with 2 fractions per week over a period of 37 to 46 days. The total dose was specified either as a maximum absorbed dose of 51.36 Gy, or as a minimum target dose of 36.6 Gy specified at the level of the mid-axilla. from 1981 to 1982, 66 patients received a minimum target dose of 40.92 Gy in 22 fractions administered as 5 fractions per week over 29 to 35 days. Late complications were evaluated prospectively at a single follow-up after a minimum observation time of 16 months. The clinical endpoints analyzed were subcutaneous fibrosis and telangiectasia. The data were analyzed using a mixture model that incorporates both dose fractionation and latency effects. The length of time to expression of 90% of the ultimate frequency of moderate or severe complications was 3.2 years (95% confidence limits (c.l.) [2.3,3.9] years) and 4.7 years (95% c.l. [4.0,.8] years) for fibrosis and telangiectasia respectively, while the α/β ratios were 1.9 Gy (95% c.l. [0.8,3.0] Gy) and 3.7 Gy (95% c.l. [0.2,47] Gy), respectively. For subcutaneous fibrosis the time to reach a specific grade of reaction increases with the grade, thus being consistent with the clinical impression that fibrosis proresses in severity over time. If latency and censoring effects are unaccounted for, serious underestimates of the ultimate frequency of radiation complications in groups with incomplete follow-up may result. (author). 13 refs.; 4 figs.; 5 tabs

  14. A System to Produce Precise Global GPS Network Solutions for all Geodetic GPS Stations in the World

    Science.gov (United States)

    Blewitt, G.; Kreemer, C. W.

    2010-12-01

    We have developed an end-to-end system that automatically seeks and routinely retrieves geodetic GPS data from ~5000 stations (currently) around the globe, reduces the data into unique, daily global network solutions, and produces high precision time series for station coordinates ready for time-series analysis, geophysical modeling and interpretation. Moreover, “carrier range” data are produced for all stations, enabling epoch-by-epoch tracking of individual station motions by precise point positioning for investigation of sub-daily processes, such as post-seismic after-slip and ocean tidal loading. Solutions are computed in a global reference frame aligned to ITRF, and optionally in user-specified continental-scale reference frames that can filter out common-mode signals to enhance regional strain anomalies. We describe the elements of this system, the underlying signal processing theory, the products, operational statistics, and scientific applications of our system. The system is fundamentally based on precise point positioning using JPL's GIPSY OASIS II software, coupled with ambiguity resolution and a global network adjustment of ~300,000 parameters per day using our newly developed Ambizap3 software. The system is designed to easily and efficiently absorb stations that deliver data very late, by recycling prior computations in the network adjustment, such that the resulting network solution is identical to starting from scratch. Thus, it becomes possible to trawl continuously the Internet for late arriving data, or for newly discovered data, and seamlessly update all GPS station time series using the new information content. As new stations are added to the processing archive, automated e-mail requests are made to H.-G. Scherneck's server at Chalmers University to compute ocean loading coefficients used by the station motion model. Rinex file headers are parsed and compared with alias tables in order to infer the correct receiver type and antenna

  15. Large time behaviour of oscillatory nonlinear solute transport in porous media

    NARCIS (Netherlands)

    Duijn, van C.J.; Zee, van der S.E.A.T.M.

    2018-01-01

    Oscillations in flow occur under many different situations in natural porous media, due to tidal, daily or seasonal patterns. In this paper, we investigate how such oscillations in flow affect the transport of an initially sharp solute front, if the solute undergoes nonlinear sorption and,

  16. Analytical solution of transient temperature in continuous wave end-pumped laser slab: Reduction of temperature distribution and time of thermal response

    Directory of Open Access Journals (Sweden)

    Shibib Khalid S.

    2017-01-01

    Full Text Available An analytical solution of transient 3-D heat equation based on integral transform method is derived. The result are compared with numerical solution, and good agreements are obtained. Minimization of response time and temperature distribution through a laser slab are tested. It is found that the increasing in the lateral convection heat transfer coefficient can significantly reduce the response time and the temperature distribution while no effect on response time is observed when changing pumping profile from Gaussian to top hat beam in spite of the latter reduce the temperature distribution, also it is found that dividing the pumping power between two slab ends might reduce the temperature distribution and it has no effect on thermal response time.

  17. Timing of the deglaciation and the late-glacial vegetation development on the Pandivere Upland, North Estonia

    Directory of Open Access Journals (Sweden)

    L. Amon

    2016-12-01

    Full Text Available In this study, the deglaciation chronology of the Pandivere Upland is defined, and the late-glacial vegetation trends of north-eastern Estonia are summarised. The multi-proxy study includes accelerated mass spectrometry 14 C dating, plant macrofossil, magnetic susceptibility, loss-on-ignition and grain-size distribution data of the lacustrine sediment record from one previously unpublished study site (Kursi, and the study discusses the results in combination with five previously published study locations from the area. The results indicate that the deglaciation of the Pandivere Upland started at approximately 14 200 cal. yr BP and was completed by 13 800 cal. yr BP. The ice recession rate was approximately 180 m yr -1 . Based on these new radiocarbon dates, the Baltic Ice Lake stage A 1 submerged the northern and western ice-free areas of Estonia by ca. 13 800 cal. yr BP. The prevalent vegetation type in north-eastern Estonia during the late-glacial period was tundra with local variations in the dominant shrub species. The region remained treeless until the Holocene.

  18. Time-dependent solution for axisymmetric flow over a blunt body with ideal gas, CF4, or equilibrium air chemistry

    Science.gov (United States)

    Hamilton, H. H., II; Spall, J. R.

    1986-01-01

    A time-asymptotic method has been used to obtain steady-flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, and spherically blunted cones. Comparisons with experimental data and results of other computational methods have demonstrated that accurate solutions can be obtained using this approach. The method should prove useful as an analysis tool for comparing with experimental data and for making engineering calculations for blunt reentry vehicles.

  19. Late-onset Huntington's disease: diagnostic and prognostic considerations.

    Science.gov (United States)

    Koutsis, Georgios; Karadima, Georgia; Kladi, Athina; Panas, Marios

    2014-07-01

    To address diagnostic and prognostic issues in patients with late-onset Huntington's disease (HD). We analyzed a cohort of 41 late-onset (≥60 years) HD patients and compared them to 39 late-onset patients referred for HD testing that were negative for the HD-expansion and to 290 usual-onset (20-59 years) HD patients. Disease severity was assessed by the Total Functional Capacity Scale. Late-onset HD comprised 11.5% of our HD cohort. In total, 70.7% of late-onset HD patients had positive family history compared to 15.4% of late-onset expansion-negative patients (p < 0.001). Clinical features at onset or presentation could not usefully distinguish between late-onset expansion-positive and negative patients, excepting hemichorea, which was absent from the HD group (p = 0.024). Chorea was the first clinical feature in 53.7% and a presenting feature in 90.2% of late-onset HD. The mutation hit rate for late-onset patients was 51.3%, lower than in usual-onset patients (p = 0.04). Frequencies of chorea, cognitive impairment and psychiatric manifestations at onset or presentation were not significantly different between late-onset and usual-onset HD patients. Gait unsteadiness however was more common at presentation in late-onset HD (p = 0.007). Late-onset HD patients reached a severe stage of illness on average 2.8 years earlier than usual-onset HD patients (p = 0.046). A positive family history suggestive of HD, although absent in a third of patients, remains a helpful clue in diagnosing late-onset HD. Prognosis of late-onset HD in terms of Total Functional Capacity appears no better and shows a trend of being somewhat less favorable compared to usual-onset HD. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Late effects on normal tissues: oesophagus

    International Nuclear Information System (INIS)

    Pavy, J.J.; Bosset, J.F.

    1997-01-01

    Radiation-induced late effects of oesophagus are observed after treatment of various cancers. Acute reactions, mainly oesophagitis, are well known and accurately described; late effects share, for most of these, a common consequence: alteration of the main oesophageal function, namely to conduct the food bolus; clinically they are impaired in terms of mobility and stenosis. More rarely, ulcerations and pseudodiverticulae can be observed. Chemotherapy further increases the risk of late effects, especially in case of concomitant chemo-radiotherapy. All numbers and statistical data on oesophagus late effects should be regarded with caution due to recent changes in the therapeutic attitudes (more and more combined chemotherapy-radiotherapy) and some progress in given cancer locations. A common scale like the LENT-SOMA should enable the clinician to better know these late effects on oesophagus which is required to initiate effective prevention measures and adapted treatments. (authors)