Electromagnetic potentials and Aharonov-Bohm effect
Ershkovich, Alexander
2012-01-01
Hamilton-Jacobi equation which governs classical mechanics and electrodynamics explicitly depends on the electromagnetic potentials (A,{\\phi}), similar to Schroedinger equation. We derived the Aharonov-Bohm effect from Hamilton-Jacobi equation thereby having proved that this effect is of classical origin. These facts enable us to arrive at the following conclusions: a) the very idea of special role of potentials (A,{\\phi}) in quantum mechanics (different from their role in classical physics) lost the ground, and becomes dubious, as this idea is based on the Aharonov-Bohm effect, b) failure to find any signs of a special role of these potentials in the appropriate experiments (Feinberg, 1963) is thereby explained, and c) discovery of classical analogues of the Aharonov-Bohm effect (Berry et al., 1980) is also explained by a classical nature of this effect. Elucidation of the physical meaning of the magnetic potential A is offered.
Thermoelectric effect in Aharonov-Bohm structures.
Lu, Xin; Wang, Jian-Sheng; Morrel, William G; Ni, Xiaoxi; Wu, Chang-Qin; Li, Baowen
2015-01-28
The thermoelectric effects of a single Aharonov-Bohm (SAB) ring and coupled double Aharonov-Bohm (DAB) rings have been investigated on a theoretical basis, taking into account the contributions of both electrons and phonons to the transport process by using the nonequilibrium Green's function technique. The thermoelectric figure of merit of the coupled DAB rings cannot be predicted directly by combining the values of two SAB ring systems due to the contribution of electron-phonon interaction to coupling between the two sites connecting the rings. We find that thermoelectric efficiency can be optimized by modulating the phases of the magnetic flux threading the two rings. PMID:25537848
Tests of the Aharonov-Bohm effect
NASA Astrophysics Data System (ADS)
Caprez, Adam Preston
The Aharonov-Bohm effect was first proposed in 1959, and has stimulated discussion and controversy since the start. Seen by many as a purely quantum mechanical effect, it nevertheless involves such issues as gauge invariance and relativistic dynamics. This multi-faceted nature has led it to be considered a keystone of modern quantum theory. Over the past half-century, interest has remained strong in what many believe is still an open debate as to the purely quantum nature. Additionally, discovery of similar effects for particles other than electrons has further driven curiosity. To better understand the issues such as electromagnetic mass and relativistic effects involved in the Aharonov-Bohm effect, a theoretical study of a simpler two particle system was done. The goal was to understand the manner in which mass of the system behaved strictly classically as compared to a relativistically. As a result of this, a Gedanken experiment is presented which serves as a test for covariance. The two particle system was extended to a spherical shell interacting with a single particle, and a second thought experiment put forth to explore a coupling between electromagnetism and gravitation. In the course of searching for simpler systems which involved the same issues as the Aharonov-Bohm effect, a system presented in the Feynman Lectures of Physics was found to be appropriate. We conduct a complete relativistic analysis of this system as a step towards a full relativistic analysis of the Aharonov-Bohm effect. Given the history and significance of the Aharonov-Bohm effect, it is perhaps surprising that relevant experimental tests had not been completed. For the first time, we searched for time delays as an electron passes a macroscopic solenoid. Such time delays are characteristic of classical forces acting on the electron. No such delays were found, seemingly confirming the standard viewpoint. It is still possible a classical explanation may exist for microscopic solenoids, though our experiment has served to place an upper limit for any such explanation. The definitive experiment concerning the Aharonov-Bohm Effect has yet to be completed. Proposed by Zeilinger, it consists of showing the dispersionless nature of the effect. To accomplish this requires an electron interferometer capable of enclosing a larger area and operating at lower energies than any which currently exist. We are attempting to construct such an interferometer using a hybrid approach with a nanofabricated grating and electron bi-prism. We have shown that experimentally that this combination can produce a large beam separation and still retain sufficient coherence to function as an interferometer.
The electric Aharonov-Bohm effect
Weder, Ricardo
2011-05-15
The seminal paper of Aharonov and Bohm [Phys. Rev. 115, 485 (1959)] is at the origin of a very extensive literature in some of the more fundamental issues in physics. They claimed that electromagnetic fields can act at a distance on charged particles even if they are identically zero in the region of space where the particles propagate, that the fundamental electromagnetic quantities in quantum physics are not only the electromagnetic fields but also the circulations of the electromagnetic potentials; what gives them a real physical significance. They proposed two experiments to verify their theoretical conclusions. The magnetic Aharonov-Bohm effect, where an electron is influenced by a magnetic field that is zero in the region of space accessible to the electron, and the electric Aharonov-Bohm effect where an electron is affected by a time-dependent electric potential that is constant in the region where the electron is propagating, i.e., such that the electric field vanishes along its trajectory. The Aharonov-Bohm effects imply such a strong departure from the physical intuition coming from classical physics that it is no wonder that they remain a highly controversial issue after more than fifty years, in spite of the fact that they are discussed in most of the text books in quantum mechanics. The magnetic case has been studied extensively. The experimental issues were settled by the remarkable experiments of Tonomura et al. [Phys. Rev. Lett. 48, 1443 (1982); Phys. Rev. Lett. 56, 792 (1986)] with toroidal magnets, that gave a strong evidence of the existence of the effect, and by the recent experiment of Caprez et al. [Phys. Rev. Lett. 99, 210401 (2007)] that shows that the results of the Tonomura et al. experiments cannot be explained by the action of a force. The theoretical issues were settled by Ballesteros and Weder [Commun. Math. Phys. 285, 345 (2009); J. Math. Phys. 50, 122108 (2009); Commun. Math. Phys. 303, 175 (2011)] who rigorously proved that quantum mechanics predicts the experimental results of Tonomura et al. and of Caprez et al. The electric Aharonov-Bohm effect has been much less studied. Actually, its existence, that has not been confirmed experimentally, is a very controversial issue. In their 1959 paper Aharonov and Bohm proposed an ansatz for the solution to the Schroedinger equation in regions where there is a time-dependent electric potential that is constant in space. It consists in multiplying the free evolution by a phase given by the integral in time of the potential. The validity of this ansatz predicts interference fringes between parts of a coherent electron beam that are subjected to different potentials. In this paper we prove that the exact solution to the Schroedinger equation is given by the Aharonov-Bohm ansatz up to an error bound in norm that is uniform in time and that decays as a constant divided by the velocity. Our results give, for the first time, a rigorous proof that quantum mechanics predicts the existence of the electric Aharonov-Bohm effect, under conditions that we provide. We hope that our results will stimulate the experimental research on the electric Aharonov-Bohm effect.
Dynamics of the Aharonov-Bohm effect
Neven Simicevic
2010-03-24
The time-dependent Dirac equation is solved using the three-dimensional Finite Difference-Time Domain (FDTD) method. The dynamics of the electron wave packet in a vector potential is studied in the arrangements associated with the Aharonov-Bohm effect. The solution of the Dirac equation showed a change in the velocity of the electron wave packet even in a region where no fields of the unperturbed solenoid acted on the electron. The solution of the Dirac equation qualitatively agreed with the prediction of classical dynamics under the assumption that the dynamics was defined by the conservation of generalized or canonical momentum of the electron.
Aharonov-Bohm radiation of fermions
Chu Yizen; Mathur, Harsh; Vachaspati, Tanmay
2010-09-15
We analyze Aharonov-Bohm radiation of charged fermions from oscillating solenoids and cosmic strings. We find that the angular pattern of the radiation has features that differ significantly from that for bosons. For example, fermionic radiation in the lowest harmonic is approximately isotropically distributed around an oscillating solenoid, whereas for bosons the radiation is dipolar. We also investigate the spin polarization of the emitted fermion-antifermion pair. Fermionic radiation from kinks and cusps on cosmic strings is shown to depend linearly on the ultraviolet cutoff, suggesting strong emission at an energy scale comparable to the string energy scale.
Deflating the Aharonov-Bohm Effect
David Wallace
2014-07-18
I argue that the metaphysical import of the Aharonov-Bohm effect has been overstated: correctly understood, it does not require either rejection of gauge invariance or any novel form of nonlocality. The conclusion that it does require one or the other follows from a failure to keep track, in the analysis, of the complex scalar field to which the magnetic vector potential is coupled. Once this is recognised, the way is clear to a local account of the ontology of electrodynamics (or at least, to an account no more nonlocal than quantum theory in general requires); I sketch a possible such account.
Quantum chaos in Aharonov-Bohm oscillations
Berman, G.P.; Campbell, D.K.; Bulgakov, E.N.; Krive, I.V.
1995-10-01
Aharonov-Bohm oscillations in a mesoscopic ballistic ring are considered under the influence of a resonant magnetic field with one and two frequencies. The authors investigate the oscillations of the time-averaged electron energy at zero temperature in the regime of an isolated quantum nonlinear resonance and at the transition to quantum chaos, when two quantum nonlinear resonances overlap. It is shown that the time-averaged energy exhibits resonant behavior as a function of the magnetic flux, and has a ``staircase`` dependence on the amplitude of the external field. The delocalization of the quasi-energy eigenfunctions is analyzed.
Scattering om two Aharonov-Bohm vortices
Eugene Bogomolny
2015-08-19
The problem of two Aharonov-Bohm (AB) vortices for the Helmholtz equation is examined in detail. It is demonstrated that the method proposed in [J. M. Myers, J. Math. Phys. \\textbf{6}, 1839 (1963)] for diffraction on a slit can be generalized to get an explicit solution for AB vortices. Due to singular nature of AB interaction the Green function and the scattering amplitude for two AB vortices obey a series of partial differential equations. Coefficients entering these equations, in their turn, fulfill ordinary non-linear differential equations whose solutions can be obtained from a solution of the Painleve V (or III) equation. The asymptotics of necessary functions for very large and very small distances between two vortices are calculated explicitly. Taken together, it means that the problem of two AB vortices is integrable.
Role of potentials in the Aharonov-Bohm effect
NASA Astrophysics Data System (ADS)
Vaidman, Lev
2012-10-01
There is a consensus today that the the main lesson of the Aharonov-Bohm effect is that a picture of electromagnetism based on the local action of the field strengths is not possible in quantum mechanics. Contrary to this statement, it is argued here that when the source of the electromagnetic potential is treated in the framework of quantum theory, the Aharonov-Bohm effect can be explained without the notion of potentials. It is explained by local action of the field of the electron on the source of the potential. The core of the Aharonov-Bohm effect is the same as the core of quantum entanglement: the quantum wave function describes all systems together.
Lorentz violation correction to the Aharonov-Bohm scattering
M. A. Anacleto
2015-10-05
In this paper, using a (2+1)-dimensional field theory approach, we study the Aharonov-Bohm (AB) scattering with Lorentz symmetry breaking. We obtain the modified scattering amplitude to the AB effect due to the small Lorentz violation correction in the breaking parameter and prove that up to one loop the model is free from ultraviolet divergences.
Symmetry-protected many-body Aharonov-Bohm effect
Santos, Luiz H.
It is known as a purely quantum effect that a magnetic flux affects the real physics of a particle, such as the energy spectrum, even if the flux does not interfere with the particle's path—the Aharonov-Bohm effect. Here ...
The Aharonov–Bohm effect in scattering theory
Sitenko, Yu.A.; Vlasii, N.D.
2013-12-15
The Aharonov–Bohm effect is considered as a scattering event with nonrelativistic charged particles of the wavelength which is less than the transverse size of an impenetrable magnetic vortex. The quasiclassical WKB method is shown to be efficient in solving this scattering problem. We find that the scattering cross section consists of two terms, one describing the classical phenomenon of elastic reflection and another one describing the quantum phenomenon of diffraction; the Aharonov–Bohm effect is manifested as a fringe shift in the diffraction pattern. Both the classical and the quantum phenomena are independent of the choice of a boundary condition at the vortex edge, providing that probability is conserved. We show that a propagation of charged particles can be controlled by altering the flux of a magnetic vortex placed on their way. -- Highlights: •Aharonov–Bohm effect as a scattering event. •Impenetrable magnetic vortex of nonzero transverse size. •Scattering cross section is independent of a self-adjoint extension employed. •Classical phenomenon of elastic reflection and quantum phenomenon of diffraction. •Aharonov–Bohm effect as a fringe shift in the diffraction pattern.
Lorentz violation correction to the Aharonov-Bohm scattering
NASA Astrophysics Data System (ADS)
Anacleto, M. A.
2015-10-01
In this paper, using a (2 +1 )-dimensional field theory approach, we study the Aharonov-Bohm (AB) scattering with Lorentz symmetry breaking. We obtain the modified scattering amplitude to the AB effect due to the small Lorentz violation correction in the breaking parameter and prove that up to one loop the model is free from ultraviolet divergences.
Aharonov-Bohm Order Parameters for Non-Abelian Gauge Theories
Hoi-Kwong Lo
1995-09-28
The Aharonov-Bohm effect has been invoked to probe the phase structure of a gauge theory. Yet in the case of non-Abelian gauge theories, it proves difficult to formulate a general procedure that unambiguously specifies the realization of the gauge symmetry, e.g. the unbroken subgroup. In this paper, we propose a set of order parameters that will do the job. We articulate the fact that any useful Aharonov-Bohm experiment necessarily proceeds in two stages: calibration and measurement. World sheets of virtual cosmic string loops can wrap around test charges, thus changing their states relative to other charges in the universe. Consequently, repeated flux measurements with test charges will not necessarily agree. This was the main stumbling block to previous attempts to construct order parameters for non-Abelian gauge theories. In those works, the particles that one uses for calibration and subsequent measurement are stored in {\\em separate} ``boxes''. By storing all test particles in the {\\em same} ``box'', we show how quantum fluctuations can be overcome. The importance of gauge fixing is also emphasized.
Spectroscopic version of the Aharonov-Bohm effect
C. Laganá
2015-06-01
An experiment is proposed in which the Aharonov-Bohm effect can be veryfied through a spectroscopic measurement. The apparatus consists of gaseous hydrochloric acid (HCl) immersed in the constant vector potential ${\\bf A}=A_0{\\bf z}$ present in the center of a toroidal coil, where ${\\bf B}=0$. Changes due to ${\\bf A}$ in the absorption spectrum of the gas are investigated.
Levinson theorem for Aharonov-Bohm scattering in two dimensions
Sheka, Denis D.; Mertens, Franz G.
2006-11-15
We apply the recently generalized Levinson theorem for potentials with inverse-square singularities [Sheka et al., Phys. Rev. A 68, 012707 (2003)] to Aharonov-Bohm systems in two dimensions (2D). By this theorem, the number of bound states in a given mth partial wave is related to the phase shift and the magnetic flux. The results are applied to 2D soliton-magnon scattering.
Inelastic transport through Aharonov-Bohm interferometer in Kondo regime
NASA Astrophysics Data System (ADS)
Yoshii, Ryosuke; Sakano, Rui; Eto, Mikio; Affleck, Ian
2013-12-01
We formulate elastic and inelastic parts of linear conductance through an Aharonov-Bohm (AB) ring with an embedded quantum dot in the Kondo regime. The inelastic part Ginel is proportional to T2 when the temperature T is much smaller than the Kondo temperature TK, whereas it is negligibly small compared with elastic part Gel when T ? TK. Ginel weakly depends on the magnetic flux penetrating the AB ring, which disturbs the precise detection of Gel/(Gel+Ginel) by the visibility of AB oscillation.
Analogue Aharonov-Bohm effect in neo-Newtonian theory
NASA Astrophysics Data System (ADS)
Anacleto, M. A.; Salako, I. G.; Brito, F. A.; Passos, E.
2015-12-01
We address the issues of the scattering of massless planar scalar waves by an acoustic black hole in neo-Newtonian hydrodynamics. We then compute the differential cross section through the use of the partial wave approach in the neo-Newtonian theory which is a modification of the usual Newtonian theory that correctly incorporates the effects of pressure. We mainly show that the scattering of planar waves leads to a modified analogue Aharonov-Bohm effect due to a nontrivial response of the parameters defining the equation of state.
Aharonov-Bohm conductance modulation in ballistic carbon nanotubes.
Lassagne, B; Cleuziou, J-P; Nanot, S; Escoffier, W; Avriller, R; Roche, S; Forró, L; Raquet, B; Broto, J-M
2007-04-27
We report on magnetoconductance experiments in ballistic multiwalled carbon nanotubes threaded by magnetic fields as large as 55 T. In the high temperature regime (100 K), giant modulations of the conductance, mediated by the Fermi level location, are unveiled. The experimental data are consistently analyzed in terms of the field-dependent density of states of the external shell that modulates the injection properties at the electrode-nanotube interface, and the resulting linear conductance. This is the first unambiguous experimental evidence of Aharonov-Bohm effect in clean multiwalled carbon nanotubes. PMID:17501520
Aharonov-Bohm Effect in a Rotating Acoustic Black Hole
NASA Astrophysics Data System (ADS)
Oliveira, E. S.; Crispino, L. C. B.; Dolan, S. R.
2015-01-01
A classical analogue to the Aharonov-Bohm (AB) effect occurs in a (idealized) draining bathtub (DBT) vortex system. The DBT vortex presents a sonic horizon, at which the flow rate exceeds the speed of sound. The sonic horizon is the analogue of a black hole event horizon. The DBT vortex also presents an ergoregion, similar to a rotating black hole. Because of the sonic event horizon, the AB effect is modified and has two tuning coefficients proportional to the flow draining and circulation couplings with the perturbation frequency.
Revisiting the Marton, Simpson, and Suddeth experimental confirmation of the Aharonov-Bohm effect
NASA Astrophysics Data System (ADS)
Macdougall, James; Singleton, Douglas; Vagenas, Elias C.
2015-09-01
We perform an "archeological" study of one of the original experiments used as evidence for the static, time-independent Aharonov-Bohm effect. Since the experiment in question [1] involved a time varying magnetic field we show that there are problems with the explanation of this experiment as a confirmation of the static Aharonov-Bohm effect - specifically the previous analysis ignored the electric field which arises in conjunction with a time-varying magnetic flux. We further argue that the results of this experiment do in fact conform exactly to the recent prediction [2,3] of a cancellation between the magnetic and electric phase shifts for the time-dependent Aharonov-Bohm effect. To resolve this issue a new time-dependent Aharonov-Bohm experiment is called for.
Interaction effects in Aharonov-Bohm-Kondo rings
NASA Astrophysics Data System (ADS)
Komijani, Yashar; Yoshii, Ryosuke; Affleck, Ian
2013-12-01
We study the conductance through an Aharonov-Bohm ring, containing a quantum dot in the Kondo regime in one arm, at finite temperature and arbitrary electronic density. We develop a general method for this calculation based on changing the basis to the screening and nonscreening channels. We show that an unusual term appears in the conductance, involving the connected four-point Green's function of the conduction electrons. However, this term and the terms quadratic in the T matrix can be eliminated at sufficiently low temperatures, leading to an expression for the conductance linear in the Kondo T matrix. Explicit results are given for temperatures that are high compared to the Kondo temperature.
The scalar complex potential and the Aharonov-Bohm effect
Y. Friedman; V. Ostapenko
2010-02-01
The Aharonov-Bohm effect is traditionally attributed to the effect of the electromagnetic 4-potential $A$, even in regions where both the electric field $\\mathbf{E}$ and the magnetic field $\\mathbf{B}$ are zero. The AB effect reveals that multiple-valued functions play a crucial role in the description of an electromagnetic field. We argue that the quantity measured by AB experiments is a difference in values of a multiple-valued complex function, which we call a complex potential or {pre-potential. We show that any electromagnetic field can be described by this pre-potential, and give an explicit expression for the electromagnetic field tensor through this potential. The pre-potential is a modification of the two scalar potential functions.
Classical light analogue of the nonlocal Aharonov-Bohm effect
Nandan Satapathy; Deepak Pandey; Poonam Mehta; Supurna Sinha; Joseph Samuel; Hema Ramachandran
2012-02-13
We demonstrate the existence of a non-local geometric phase in the intensity-intensity correlations of classical incoherent light, that is not seen in the lower order correlations. This two-photon Pancharatnam phase was observed and modulated in a Mach-Zehnder interferometer. Using acousto-optic interaction, independent phase noise was introduced to light in the two arms of the interferometer to create two independent incoherent classical sources from laser light. The experiment is the classical optical analogue of the multi-particle Aharonov-Bohm effect. As the trajectory of light over the Poincare sphere introduces a phase shift observable only in the intensity-intensity correlation, it provides a means of deflecting the two-photon wavefront, while having no effect on single photons.
Aharonov-Bohm phases in a quantum LC circuit
ChunJun Cao; Yuan Yao; Ariel R. Zhitnitsky
2015-12-01
We study novel types of contributions to the partition function of the Maxwell system defined on a small compact manifold. These contributions, often not addressed in the perturbative treatment with physical photons, emerge as a result of tunneling transitions between topologically distinct but physically identical vacuum winding states. These new terms give an extra contribution to the Casimir pressure, yet to be measured. We argue that this effect is highly sensitive to a small external electric field, which should be contrasted with the conventional Casimir effect where the vacuum photons are essentially unaffected by any external field. Furthermore, photons will be emitted from the vacuum in response to a time-dependent electric field, similar to the dynamical Casimir effect in which real particles are radiated from the vacuum due to the time-dependent boundary conditions. We also propose an experimental setup using a quantum LC circuit to detect this novel effect. We expect physical electric charges to appear on the capacitor plates when the system dimension is such that coherent Aharonov-Bohm phases can be maintained over macroscopically large distances.
Aharonov-Bohm effect, local field interaction, and Lorentz invariance
Kicheon Kang
2015-02-03
Aharonov-Bohm (AB) effect [1,2], known as a milestone in our understanding of electromagnetic interactions, describes a quantum interference of a charged particle moving under the influence of a potential. In sharp contrast with classical theory of electrodynamics, AB effect qualifies potential as a physical reality, rather than as a mere mathematical tool, because the interference is affected by a potential even when a charged particle moves in a field-free region. Aharonov-Casher (AC) effect [3], dual to the AB phenomenon, shows a phase shift of a fluxon moving around a charge (in two-dimensional case). It has been shown that AC effect is also free of force [4,5], but standard view draws a clear distinction between the two phenomena in that the fluxon moves under a nonvanishing field generated by the charge in the case of AC effect [6]. Despite the fact that the observable phenomena depend only on the relative motion of a charge and a fluxon, a unified picture, fully consistent with the principle of relativity, is lacking. Here, we provide a unified theory which resolves the question of relativity, based on a Lorentz-invariant field-interaction between a charge and a localized flux. The AB effect can be understood in this fully relativistic viewpoint. The AB phase shift is derived from the Lorentz-covariant interaction Lagrangian, and the force-free nature of the effect is also confirmed.
Line of magnetic monopoles and an extension of the Aharonov-Bohm effect
J. Chee; W. Lu
2016-01-05
In the Landau problem on the two-dimensional plane, magnetic translation of a quantum wave can be induced by an in-plane electric field. The geometric phase accompanying such magnetic translation around a closed path differs from the topological phase of Aharonov and Bohm in two aspects: The wave is in direct contact with the magnetic flux and the geometric phase has an opposite sign from the Aharonov-Bohm phase. We show that magnetic translation on the two-dimensional cylinder implemented by the Schr\\"odinger time evolution truly leads to an identification of the Berry phase with the Aharonov-Bohm phase. The magnetic field at the cylinder's surface corresponds to a line of monopoles which can be simulated in cold atom experiments. We propose an extension of the Aharonov-Bohm experiment which can demonstrate the mutually counteracting effect between the local magnetic translation geometric phase and the topological phase of Aharonov and Bohm.
Cloaking of matter waves under the global Aharonov-Bohm effect
Lin, D.-H.; Luan, P.-G.
2009-05-15
We discuss the Aharonov-Bohm effect of a magnetic flux for its influence on a two-dimensional quantum cloak. It is shown that the matter wave of a charged particle under the global influence of the Aharonov-Bohm effect can still be perfectly cloaked and guided by the quantum cloak. Since the presence of the global influence of a magnetic flux on charged particles is universal, the perfect cloaking and guiding nature not only provides an ideal setup to cloak an object from matter waves but also provides an ideal setup to test the global physics of charged matter waves in the presence of a bare magnetic flux.
Photon mass and quantum effects of the Aharonov-Bohm type
Spavieri, G.; Rodriguez, M.
2007-05-15
The magnetic field due to the photon rest mass m{sub ph} modifies the standard results of the Aharonov-Bohm effect for electrons, and of other recent quantum effects. For the effect involving a coherent superposition of beams of particles with opposite electromagnetic properties, by means of a tabletop experiment, the limit m{sub ph}{approx_equal}10{sup -51} g is achievable, improving by 6 orders of magnitude that derived by Boulware and Deser for the Aharonov-Bohm effect.
Aharonov-Bohm interferometry with a tunnel-coupled wire
NASA Astrophysics Data System (ADS)
Aharony, A.; Takada, S.; Entin-Wohlman, O.; Yamamoto, M.; Tarucha, S.
2014-08-01
Recent experiments (Yamamoto et al 2012 Nature Nanotechnology 7 247) used the transport of electrons through an Aharonov-Bohm (AB) interferometer and two coupled channels (at both ends of the interferometer) to demonstrate a manipulable flying qubit. Results included in-phase and anti-phase (AB) oscillations of the two outgoing currents as a function of the magnetic flux, for strong and weak inter-channel coupling, respectively. Here we present new experimental results for a three terminal interferometer, with a tunnel coupling between the two outgoing wires. We show that in some limits, this system is an even simpler realization of the ‘two-slit’ experiment. We also present a simple tight-binding theoretical model which imitates the experimental setup. For weak inter-channel coupling, the AB oscillations in the current which is reflected from the device are very small, and therefore the oscillations in the two outgoing currents must cancel each other, yielding the anti-phase behavior, independent of the length of the coupling regime. Technically, the tight binding equations within the two coupled wires have four solutions for each electronic energy. In the ‘anti-phase’ region all of these solutions are wave-like, oscillating with the distance along the wires. As the coupling between the wires increases, two of these solutions become evanescent, and their amplitudes decay as the electron moves in the wires. In this regime, the amplitudes of the two remaining ‘running’ waves are proportional to each other, with a ratio which is practically flux-independent. As a result, the two outgoing currents are proportional to each other, yielding the ‘in phase’ behavior. For larger coupling all the solutions are evanescent, and the outgoing currents become very small.
Modular Momentum of the Aharonov-Bohm Effect on Noncommutative Lattices
Takeo Miura
2012-07-23
Based on the technique of noncommutative geometry, it is shown that, by means of the concept of the theta quantization, there is an equivalence between the notion of the modular momentum of the Aharonov-Bohm effect and the notion of a noncommutative lattice over a circle poset.
Aharonov-Bohm Scattering of a Localized Wave Packet: Analysis of the Forward Direction
Davide Stelitano
1994-11-23
The Aharonov-Bohm scattering of a localized wave packet is considered. A careful analysis of the forward direction points out new results: according to the time-dependent solution obtained by means of the asymptotic representation for the propagator (kernel), a phenomenon of auto-interference occurs along the forward direction, where, also, the probability density current is evaluated and found finite.
Aharonov-Bohm effect and geometric phase And all I wanted was a complex carrot.
Johannesson, Henrik
- ematical foundation of what came to be known as the Standard Model of Physics. The 1959 paper by David Bohm through regions where the David Bohm (1917-1992) was a major figure in 20th century physics. He also led. David Bohm Yakir Aharonov #12;Aharonov-Bohm effect and geometric phase 211 potentials
Revisiting the Marton, Simpson, and Suddeth experimental confirmation of the Aharonov-Bohm effect
James Macdougall; Douglas Singleton; Elias C. Vagenas
2015-05-16
We perform an "archeological" study of one of the original experiments used as evidence for the static, time-independent Aharonov-Bohm effect. Since the experiment in question [L. Marton, J. A. Simpson, and J. A. Suddeth, Rev. Sci. Instr. 25, 1099 (1954)] involved a time varying magnetic field we show that there are problems with the explanation of this experiment as a confirmation of the static Aharonov-Bohm effect -- specifically the previous analysis ignored the electric field which arises in conjunction with a time-varying magnetic flux. We further argue that the results of this experiment do in fact conform exactly to the recent prediction [D. Singleton and E. Vagenas, Phys. Lett. B723, 241 (2013); J. MacDougall and D. Singleton, J. Math. Phys. 55, 042101 (2014)] of a cancellation between the magnetic and electric phase shifts for the time-dependent Aharonov-Bohm effect. To resolve this issue a new time-dependent Aharonov-Bohm experiment is called for.
Revisiting the Marton, Simpson, and Suddeth experimental confirmation of the Aharonov-Bohm effect
Macdougall, James; Vagenas, Elias C
2015-01-01
We perform an "archeological" study of one of the original experiments used as evidence for the static, time-independent Aharonov-Bohm effect. Since the experiment in question [L. Marton, J. A. Simpson, and J. A. Suddeth, Rev. Sci. Instr. 25, 1099 (1954)] involved a time varying magnetic field we show that there are problems with the explanation of this experiment as a confirmation of the static Aharonov-Bohm effect -- specifically the previous analysis ignored the electric field which arises in conjunction with a time-varying magnetic flux. We further argue that the results of this experiment do in fact conform exactly to the recent prediction [D. Singleton and E. Vagenas, Phys. Lett. B723, 241 (2013); J. MacDougall and D. Singleton, J. Math. Phys. 55, 042101 (2014)] of a cancellation between the magnetic and electric phase shifts for the time-dependent Aharonov-Bohm effect. To resolve this issue a new time-dependent Aharonov-Bohm experiment is called for.
Stokes' theorem, gauge symmetry and the time-dependent Aharonov-Bohm effect
Macdougall, James Singleton, Douglas
2014-04-15
Stokes' theorem is investigated in the context of the time-dependent Aharonov-Bohm effect—the two-slit quantum interference experiment with a time varying solenoid between the slits. The time varying solenoid produces an electric field which leads to an additional phase shift which is found to exactly cancel the time-dependent part of the usual magnetic Aharonov-Bohm phase shift. This electric field arises from a combination of a non-single valued scalar potential and/or a 3-vector potential. The gauge transformation which leads to the scalar and 3-vector potentials for the electric field is non-single valued. This feature is connected with the non-simply connected topology of the Aharonov-Bohm set-up. The non-single valued nature of the gauge transformation function has interesting consequences for the 4-dimensional Stokes' theorem for the time-dependent Aharonov-Bohm effect. An experimental test of these conclusions is proposed.
The Aharonov-Bohm effect and Tonomura et al. experiments: Rigorous results
Ballesteros, Miguel; Weder, Ricardo
2009-12-15
The Aharonov-Bohm effect is a fundamental issue in physics. It describes the physically important electromagnetic quantities in quantum mechanics. Its experimental verification constitutes a test of the theory of quantum mechanics itself. The remarkable experiments of Tonomura et al. ['Observation of Aharonov-Bohm effect by electron holography', Phys. Rev. Lett 48, 1443 (1982) and 'Evidence for Aharonov-Bohm effect with magnetic field completely shielded from electron wave', Phys. Rev. Lett 56, 792 (1986)] are widely considered as the only experimental evidence of the physical existence of the Aharonov-Bohm effect. Here we give the first rigorous proof that the classical ansatz of Aharonov and Bohm of 1959 ['Significance of electromagnetic potentials in the quantum theory', Phys. Rev. 115, 485 (1959)], that was tested by Tonomura et al., is a good approximation to the exact solution to the Schroedinger equation. This also proves that the electron, that is, represented by the exact solution, is not accelerated, in agreement with the recent experiment of Caprez et al. in 2007 ['Macroscopic test of the Aharonov-Bohm effect', Phys. Rev. Lett. 99, 210401 (2007)], that shows that the results of the Tonomura et al. experiments can not be explained by the action of a force. Under the assumption that the incoming free electron is a Gaussian wave packet, we estimate the exact solution to the Schroedinger equation for all times. We provide a rigorous, quantitative error bound for the difference in norm between the exact solution and the Aharonov-Bohm Ansatz. Our bound is uniform in time. We also prove that on the Gaussian asymptotic state the scattering operator is given by a constant phase shift, up to a quantitative error bound that we provide. Our results show that for intermediate size electron wave packets, smaller than the ones used in the Tonomura et al. experiments, quantum mechanics predicts the results observed by Tonomura et al. with an error bound smaller than 10{sup -99}. It would be quite interesting to perform experiments with electron wave packets of intermediate size. Furthermore, we provide a physical interpretation of our error bound.
NASA Astrophysics Data System (ADS)
Matityahu, Shlomi; Aharony, Amnon; Entin-Wohlman, Ora; Katsumoto, Shingo
2013-05-01
In an earlier paper [A. Aharony, Y. Tokura, G. Z. Cohen, O. Entin-Wohlman, and S. Katsumoto, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.84.035323 84, 035323 (2011)], we proposed a spin filter that was based on a diamond-like interferometer, subject to both an Aharonov-Bohm flux and (Rashba and Dresselhaus) spin-orbit interactions. Here, we show that the full polarization of the outgoing electron spins remains the same even when one allows leakage of electrons from the branches of the interferometer. Once the gate voltage on one of the branches is tuned to achieve an effective symmetry between them, this polarization can be controlled by the electric and/or magnetic fields, which determine the spin-orbit interaction strength and the Aharonov-Bohm flux.
Noncommutative correction to Aharonov-Bohm scattering: A field theory approach
Anacleto, M.A.; Gomes, M.; Silva, A.J. da; Spehler, D.
2004-10-15
We study a noncommutative nonrelativistic theory in 2+1 dimensions of a scalar field coupled to the Chern-Simons field. In the commutative situation this model has been used to simulate the Aharonov-Bohm effect in the field theory context. We verified that, contrary to the commutative result, the inclusion of a quartic self-interaction of the scalar field is not necessary to secure the ultraviolet renormalizability of the model. However, to obtain a smooth commutative limit the presence of a quartic gauge invariant self-interaction is required. For small noncommutativity we fix the corrections to the Aharonov-Bohm scattering and prove that up to one loop the model is free from dangerous infrared/ultraviolet divergences.
Time-dependent Pauli equation in the presence of the Aharonov-Bohm effect
Bouguerra, Y.; Bounames, A.; Maamache, M.; Saadi, Y.
2008-04-15
We use the Lewis-Riesenfeld theory to determine the exact form of the wavefunctions of a two-dimensional Pauli equation of a charged spin 1/2 particle with time-dependent mass and frequency in the presence of the Aharonov-Bohm effect and a two-dimensional time-dependent harmonic oscillator. We find that the irregular solution at the origin as well as the regular one contributes to the phase of the wavefunction.
NASA Astrophysics Data System (ADS)
Kibis, O. V.; Sigurdsson, H.; Shelykh, I. A.
2015-06-01
We show theoretically that the strong coupling of circularly polarized photons to an exciton in ringlike semiconductor nanostructures results in physical nonequivalence of clockwise and counterclockwise exciton rotations in the ring. As a consequence, the stationary energy splitting of exciton states corresponding to these mutually opposite rotations appears. This excitonic Aharonov-Bohm effect depends on the intensity and frequency of the circularly polarized field and can be detected in state-of-the-art optical experiments.
Entanglement entropy as a witness of the Aharonov-Bohm effect in QFT
Raúl E. Arias; David D. Blanco; Horacio Casini
2014-09-10
We study the dependence of the entanglement entropy with a magnetic flux, and show that the former quantity witnesses an Aharonov Bohm-like effect. In particular, we consider free charged scalar and Dirac fields living on a two dimensional cylinder and study how the entanglement entropy for a strip-like region on the surface of the cylinder is affected by a magnetic field enclosed by it.
A charged particle in a homogeneous magnetic field accelerated by a time periodic Aharonov-Bohm flux
T. Kalvoda; P. Stovicek
2011-07-14
We consider a nonrelativistic quantum charged particle moving on a plane under the influence of a uniform magnetic field and driven by a periodically time-dependent Aharonov-Bohm flux. We observe an acceleration effect in the case when the Aharonov-Bohm flux depends on time as a sinusoidal function whose frequency is in resonance with the cyclotron frequency. In particular, the energy of the particle increases linearly for large times. An explicit formula for the acceleration rate is derived with the aid of the quantum averaging method, and then it is checked against a numerical solution with a very good agreement.
NASA Astrophysics Data System (ADS)
Lai, Wenxi; Xing, Yunhui; Ma, Zhongshui
2013-05-01
Phase relaxation of electrons transferring through an electromechanical transistor is studied using the Aharonov-Bohm interferometer. Using the quantum master equation approach, the phase properties of an electron are numerically analyzed based on the interference fringes. The coherence of the electron is partially destroyed by its scattering on excited levels of the local nanomechanical oscillator. The transmission amplitudes with respect to two adjacent mechanical vibrational levels have a phase difference of ?. The character of the ? phase shift depends on the oscillator frequency only and is robust over a wide range of values of the applied voltage, tunneling length and damping rate of the mechanical oscillator.
Yuan, Luqi; Xu, Shanshan; Fan, Shanhui
2015-11-15
We show that nonreciprocal unidirectional single-photon quantum transport can be achieved with the photonic Aharonov-Bohm effect. The system consists of a 1D waveguide coupling to two three-level atoms of the V-type. The two atoms, in addition, are each driven by an external coherent field. We show that the phase of the external coherent field provides a gauge potential for the photon states. With a proper choice of the phase difference between the two coherent fields, the transport of a single photon can exhibit unity contrast in its transmissions for the two propagation directions. PMID:26565819
Absence of the Electric Aharonov-Bohm Effect due to Induced Charges
Wang, Rui-Feng
2015-01-01
This paper states that the induced charge should not be neglected in the electric Aharonov-Bohm (A-B) effect. If the induced charge is taken into account, the interference pattern of the moving charge will not change with the potential difference between the two metal tubes. It means that the scalar potential itself can not affect the phase of the moving charge, and the true factor affecting the phase of the moving charge is the energy of the system including the moving charge and the induced charge. PMID:26392302
The Aharonov-Bohm Effect in a 3D topological insulator nanowire
NASA Astrophysics Data System (ADS)
Cho, Sungjae; Dellabetta, Brian; Yang, Alina; Schneeloch, John; Xu, Zhijun; Gu, Genda; Gilbert, Matthew; Mason, Nadya
2014-03-01
The three dimensional topological insulator (3D TI) is a new class of material having metallic surface states characterized by gapless Dirac dispersions and novel properties such as momentum-spin locking. A TI nanowire with an insulating bulk can be described as a hollow metallic cylinder, showing Aharonov-Bohm oscillations when a magnetic flux is threaded through the axis. The magneto-conductance of a TI nanowire near the Dirac point is expected to have a minimum at zero magnetic field and an oscillation period of one magnetic flux quantum, ? (due to a Berry phase of ? acquired by electron waves upon 2 ? rotation of electron spin around the surface of the nanowire). In this talk, we discuss magneto-conductance measurements of TI (Bi2Se3) nanowires, measured as the gate voltage is tuned through the Dirac point. The Aharonov-Bohm oscillations switch from a conductance maximum to a minimum at zero field as the Dirac point is approached, consistent with the existence of a Berry phase in the nanowire.
Enhanced spin figure of merit in an Aharonov-Bohm ring with a double quantum dot
Zhou, Xingfei; Qi, Fenghua; Jin, Guojun
2014-04-21
We theoretically investigate the thermoelectric effects in an Aharonov-Bohm ring with a serially coupled double quantum dot embedded in one arm. An external magnetic field is perpendicularly applied to the two dots. Using the nonequilibrium Green's function method in the linear-response regime, we calculate the charge and spin figures of merit. When the energy levels of the two quantum dots are equal and the system is connected to two normal leads, a large spin figure of merit (Z{sub s}T???4.5) accompanying with a small charge figure of merit (Z{sub c}T???0) can be generated due to the remarkable bipolar effect. Further, when the system is connected to two ferromagnetic leads, the spin figure of merit can reach even a higher value about 9. Afterwards, we find that Z{sub s}T is enhanced while Z{sub c}T is reduced in the coaction of the Aharonov-Bohm flux and Rashba spin-orbit coupling. It is argued that the bipolar effect is positive (negative) to spin (charge) figure of merit in the presence of level detuning of the two quantum dots and intradot Coulomb interactions, respectively. Also, we propose a possible experiment to verify our results.
Andrade, F.M.; Silva, E.O.; Pereira, M.
2013-12-15
In this work the bound state and scattering problems for a spin- 1/2 particle undergone to an Aharonov–Bohm potential in a conical space in the nonrelativistic limit are considered. The presence of a ?-function singularity, which comes from the Zeeman spin interaction with the magnetic flux tube, is addressed by the self-adjoint extension method. One of the advantages of the present approach is the determination of the self-adjoint extension parameter in terms of physics of the problem. Expressions for the energy bound states, phase-shift and S matrix are determined in terms of the self-adjoint extension parameter, which is explicitly determined in terms of the parameters of the problem. The relation between the bound state and zero modes and the failure of helicity conservation in the scattering problem and its relation with the gyromagnetic ratio g are discussed. Also, as an application, we consider the spin- 1/2 Aharonov–Bohm problem in conical space plus a two-dimensional isotropic harmonic oscillator. -- Highlights: •Planar dynamics of a spin- 1/2 neutral particle. •Bound state for Aharonov–Bohm systems. •Aharonov–Bohm scattering. •Helicity nonconservation. •Determination of the self-adjoint extension parameter.
Energy Spectrum of a 2D Dirac Oscillator in the Presence of the Aharonov-Bohm Effect
N. Ferkous; A. Bounames
2008-01-30
We determine the energy spectrum and the corresponding eigenfunctions of a 2D Dirac oscillator in the presence of Aharonov-Bohm (AB) effect . It is shown that the energy spectrum depends on the spin of particle and the AB magnetic flux parameter. Finally, when the irregular solution occurs it is shown that the energy takes particular values. The nonrelativistic limit is also considered.
Topological phases reviewed: The Aharonov Bohm, Aharonov Casher, and He McKellar Wilkens phases
McKellar, B. H. J.; He, X-G.; Klein, A. G.
2014-03-05
There are three topological phases related to electromagnetic interactions in quantum mechanics: 1. The Aharonov Bohm phase acquired when a charged particle encircles a magnetic field but travels through a field free region. 2. The Aharonov Casher phase acquired when a magnetic dipole encircles electric charges but travels through a charge free region. 3. The He McKellar Wilkens phase acquired when an electric dipole encircles magnetic charges but travels through a charge free region. We review the conditions under which these phases are indeed topological and their experimental realisation. Because the He McKellar Wilkens phase has been recently observed we pay particular attention to how the basic concept of 'an electric dipole encircles magnetic charges' was realised experimentally, and discuss possible future experimental realisations.
A possible interplay between electron beams and magnetic fluxes in the Aharonov-Bohm effect
NASA Astrophysics Data System (ADS)
Wang, Rui-Feng
2015-06-01
Most studies on the magnetic Aharonov-Bohm (A-B) effect focus on the action exerted by the magnetic flux on the electron beam, but neglect the back-action exerted by the electron beam on the magnetic flux. This paper focuses on the latter, which is the electromotive force ? U across the solenoid induced by the time-dependent magnetic field of the electron beam. Based on the back-action analysis, we observe that the magnetic A-B effect arises owing to the interaction energy between the magnetic field of the electron beam and the magnetic field of the solenoid. We also demonstrate that the interpretation attributing the magnetic A-B effect to the vector potential violates the uncertainty principle.
Thermoelectric effect in an Aharonov-Bohm ring with an embedded quantum dot
2012-01-01
Thermoelectric effect is studied in an Aharonov-Bohm interferometer with an embedded quantum dot (QD) in the Coulomb blockade regime. The electrical conductance, electron thermal conductance, thermopower, and thermoelectric figure-of-merit are calculated by using the Keldysh Green's function method. It is found that the figure-of-merit ZT of the QD ring may be quite high due to the Fano effect originated from the quantum interference effect. Moreover, the thermoelectric efficiency is sensitive to the magnitude of the dot-lead and inter-lead coupling strengthes. The effect of intradot Coulomb repulsion on ZT is significant in the weak-coupling regime, and then large ZT values can be obtained at rather high temperature. PMID:22369454
Sensitive spin-polarization effects in an Aharonov-Bohm double quantum dot ring
NASA Astrophysics Data System (ADS)
Hedin, Eric R.; Joe, Yong S.
2011-07-01
We study spin-dependent transport and spin polarization through two asymmetric quantum dots (QD's) embedded in the arms of an Aharonov-Bohm (AB) ring, in which spin splitting produced by external magnetic fields is incorporated into a tight-binding model Hamiltonian. This device shows a sensitive spin-polarization effect by manipulating either in-plane or perpendicular magnetic fields. In particular, an extremely small Zeeman splitting leads to a reversal of the polarization polarity in the differential weighted spin-polarization function. Finally, we demonstrate that the degree of spin polarization is affected by the additional AB effects in the ring. In comparison, the polarization is substantially lower through a single QD in a one-dimensional system.
The manifestly covariant Aharonov-Bohm effect in terms of the 4D fields
Tomislav Ivezic
2014-11-21
In this paper it is presented a manifestly covariant formulation of the Aharonov-Bohm (AB) phase difference for the magnetic AB effect . This covariant AB phase is written in terms of the Faraday 2-form F and using the decomposition of F in terms of the electric and magnetic fields as four-dimensional (4D) geometric quantities. It is shown that there is a static electric field outside a stationary solenoid with resistive conductor carrying steady current, which causes that the AB phase difference in the magnetic AB effect may be determined by the electric part of the covariant expression, i.e. by the local influence of the 4D electric field and not, as generally accepted,in terms of nonzero vector potential.
Constantine Yannouleas; Igor Romanovsky; Uzi Landman
2015-02-16
The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended graphene systems, to a massive relativistic behavior in narrow armchair GNRs, and the emergence of nonrelativistic behavior in zigzag-terminated GNRs. Evaluation of the electronic states in a polygonal graphene nanoring under the influence of an applied magnetic field in the Aharonov-Bohm regime, and their analysis with the use of a relativistic quantum-field theoretical model, unveils development of a topological-in-origin zero-energy soliton state and charge fractionization. These results provide a unifying framework for analysis of electronic states, coherent transport phenomena, and the interpretation of forthcoming experiments in segmented graphene nanoribbons and polygonal rings.
Aharonov-Bohm interference in gate-defined ring of high-mobility graphene
NASA Astrophysics Data System (ADS)
Kim, Minsoo; Lee, Hu-Jong
2015-03-01
Recent progress in preparing a high-quality graphene layer enables one to investigate the intrinsic carrier transport nature in the material. Here, we report the signature of conservation of the Berry's phase with preserved valley symmetry in Aharonov-Bohm (AB) interferometers fabricated on monolayer graphene with high carrier mobility, where the graphene was sandwiched between two thin hexagonal boron nitride (h-BN) layers. In measurements, charge carriers were confined in an AB ring-shaped potential well formed by the dual-gate operation of the bottom and top gates and the four-terminal magneto-conductance (MC) was measured with varying charge carrier density and temperature. Graphene in the device was in the ballistic regime as confirmed by the conductance quantization in steps of ?G = 4e2/ h in a constricted conducting channel of separate measurements. We observed h/e periodic modulation of MC and the zero-field conductance minimum with a negative MC background. The phase information of AB interference strongly suggests that carriers in the graphene in our devices preserve the intrinsic Dirac transport nature, which would be conveniently utilized for valleytronics in graphene.
Aharonov-Bohm Effect and High-Momenta Inverse Scattering for the Klein-Gordon Equation
Miguel Ballesteros; Ricardo Weder
2015-06-03
We analyze spin-0 relativistic scattering of charged particles propagating in the exterior, $\\Lambda \\subset \\mathbb{R}^3$, of a compact obstacle $K \\subset \\mathbb{R}^3$. The connected components of the obstacle are handlebodies. The particles interact with an electro-magnetic field in $\\Lambda$ and an inaccessible magnetic field localized in the interior of the obstacle (through the Aharonov-Bohm effect). We obtain high-momenta estimates, with error bounds, for the scattering operator that we use to recover physical information: We give a reconstruction method for the electric potential and the exterior magnetic field and prove that, if the electric potential vanishes, circulations of the magnetic potential around handles (or equivalently, by Stokes' theorem, magnetic fluxes over transverse sections of handles) of the obstacle can be recovered, modulo $2 \\pi$. We additionally give a simple formula for the high-momenta limit of the scattering operator in terms of certain magnetic fluxes, in the absence of electric potential. If the electric potential does not vanish, the magnetic fluxes on the handles above referred can be only recovered modulo $\\pi$ and the simple expression of the high-momenta limit of the scattering operator does not hold true.
A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms
Ming-Xia Huo; Nie Wei; David A. W. Hutchinson; Leong Chuan Kwek
2014-08-11
Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a "hairline" solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.
T. Kubo; Y. Tokura; S. Tarucha
2010-05-12
We theoretically investigated the dephasing in an Aharonov-Bohm interferometer containing a lateral double quantum dot induced by coupling with a quantum dot charge sensor. We employed the interpolative 2nd-order perturbation theory to include the charge sensing Coulomb interaction. It is shown that the visibility of the Aharonov-Bohm oscillation of the linear conductance decreases monotonically as the sensing Coulomb interaction increases. In particular, for a weak sensing interaction regime, the visibility decreases parabolically, and it behaves linearly for a strong sensing interaction regime.
NASA Astrophysics Data System (ADS)
Avossevou, Gabriel Y. H.; Ahounou, Bernadin D.
2014-09-01
In this paper we study the stationary scattering problem of the Aharonov-Bohm (AB) effect. To achieve this goal we construct a Hamiltonian from the most general representations of the Heisenberg algebra. Such representations are defined on a non-simply-connected manifold which we set as the flat circular annulus. By means of the von Neumann's self-adjoint extensions formalism, the scattering data are then provided. No solenoid is considered in this paper. The corresponding Hamiltonian is based on a topological quantum degree of freedom inherent in such representations. This variable stands for the magnetic vector gauge potential at quantum level. Our outcomes confirm the topological nature of this effect.
Aharonov-Bohm effect on AdS_2 and nonlinear supersymmetry of reflectionless Poschl-Teller system
Francisco Correa; Vit Jakubsky; Mikhail S. Plyushchay
2009-03-29
We explain the origin and the nature of a special nonlinear supersymmetry of a reflectionless Poschl-Teller system by the Aharonov-Bohm effect for a nonrelativistic particle on the AdS_2. A key role in the supersymmetric structure appearing after reduction by a compact generator of the AdS_2 isometry is shown to be played by the discrete symmetries related to the space and time reflections in the ambient Minkowski space. We also observe that a correspondence between the two quantum non-relativistic systems is somewhat of the AdS/CFT holography nature.
Murray Peshkin
1995-10-20
The Hamiltonian describing a conductor surrounding an external magnetic field contains a nonvanishing vector potential in the volume accessible to the electrons and nuclei of which the conductor is made. That vector potential cannot be removed by a gauge transformation. Nevertheless, a macroscopic normal conductor can experience no Aharonov-Bohm effect. That is proved by assuming only that a normal conductor lacks off-diagonal long-range order (ODLRO). Then by restricting the Hilbert space to density matrices which lack ODLRO, it is possible to introduce a restricted gauge transformation that removes the interaction of the conductor with the vector potential.
High-Velocity Estimates for the Scattering Operator and Aharonov-Bohm Effect in Three Dimensions
Miguel Ballesteros; Ricardo Weder
2007-11-16
We obtain high-velocity estimates with error bounds for the scattering operator of the Schr\\"odinger equation in three dimensions with electromagnetic potentials in the exterior of bounded obstacles that are handlebodies. A particular case is a finite number of tori. We prove our results with time-dependent methods. We consider high-velocity estimates where the direction of the velocity of the incoming electrons is kept fixed as its absolute value goes to infinity. In the case of one torus our results give a rigorous proof that quantum mechanics predicts the interference patterns observed in the fundamental experiments of Tonomura et al. that gave a conclusive evidence of the existence of the Aharonov-Bohm effect using a toroidal magnet. We give a method for the reconstruction of the flux of the magnetic field over a cross-section of the torus modulo $2\\pi$. Equivalently, we determine modulo $2\\pi$ the difference in phase for two electrons that travel to infinity, when one goes inside the hole and the other outside it. For this purpose we only need the high-velocity limit of the scattering operator for one direction of the velocity of the incoming electrons. When there are several tori -or more generally handlebodies- the information that we obtain in the fluxes, and on the difference of phases, depends on the relative position of the tori and on the direction of the velocities when we take the high-velocity limit of the incoming electrons. For some locations of the tori we can determine all the fluxes modulo 2$\\pi$ by taking the high-velocity limit in only one direction. We also give a method for the unique reconstruction of the electric potential and the magnetic field outside the handlebodies from the high-velocity limit of the scattering operator.
On the Aharonov-Bohm Operators with Varying Poles: The Boundary Behavior of Eigenvalues
NASA Astrophysics Data System (ADS)
Noris, Benedetta; Nys, Manon; Terracini, Susanna
2015-11-01
We consider a magnetic Schrödinger operator with magnetic field concentrated at one point (the pole) of a domain and half integer circulation, and we focus on the behavior of Dirichlet eigenvalues as functions of the pole. Although the magnetic field vanishes almost everywhere, it is well known that it affects the operator at the spectral level (the Aharonov-Bohm effect, Phys Rev (2) 115:485-491, 1959). Moreover, the numerical computations performed in (Bonnaillie-Noël et al., Anal PDE 7(6):1365-1395, 2014; Noris and Terracini, Indiana Univ Math J 59(4):1361-1403, 2010) show a rather complex behavior of the eigenvalues as the pole varies in a planar domain. In this paper, in continuation of the analysis started in (Bonnaillie-Noël et al., Anal PDE 7(6):1365-1395, 2014; Noris and Terracini, Indiana Univ Math J 59(4):1361-1403, 2010), we analyze the relation between the variation of the eigenvalue and the nodal structure of the associated eigenfunctions. We deal with planar domains with Dirichlet boundary conditions and we focus on the case when the singular pole approaches the boundary of the domain: then, the operator loses its singular character and the k-th magnetic eigenvalue converges to that of the standard Laplacian. We can predict both the rate of convergence and whether the convergence happens from above or from below, in relation with the number of nodal lines of the k-th eigenfunction of the Laplacian. The proof relies on the variational characterization of eigenvalues, together with a detailed asymptotic analysis of the eigenfunctions, based on an Almgren-type frequency formula for magnetic eigenfunctions and on the blow-up technique.
Shepelyansky, Dima
Mesoscopic photovoltaic effect in GaAs/Ga1-xAlxAs Aharonov-Bohm rings L. Angers, A. Chepelianskii specific dc voltage. We have investigated this photovoltaic PV effect on GaAs/Ga1-xAlxAs Aharonov is generally done by measuring the dc induced signal sometimes called photovoltaic effect which has also given
H. Najar; M. Rayssi
2012-11-10
In a previous study \\cite{n} we investigate the bound states of the Hamiltonian describing a quantum particle living on three dimensional straight strip of width $d$. We impose the Neumann boundary condition on a disc window of radius $a$ and Dirichlet boundary conditions on the remained part of the boundary of the strip. We proved that such system exhibits discrete eigenvalues below the essential spectrum for any $a>0$. In the present work we study the effect of a magnetic filed of Aharonov-Bohm type when the magnetic field is turned on this system. Precisely we prove that in the presence of such magnetic filed there is some critical values of $a_0>0$, for which we have absence of the discrete spectrum for $\\displaystyle 0<\\frac{a}{d}
Quantum motion of a point particle in the presence of the Aharonov--Bohm potential in curved space
Edilberto O. Silva; Sérgio C. Ulhoa; Fabiano M. Andrade; Cleverson Filgueiras; R. G. G. Amorin
2015-10-23
The nonrelativistic quantum dynamics of a spinless charged particle in the presence of the Aharonov--Bohm potential in curved space is considered. We chose the surface as being a cone defined by a line element in polar coordinates. The geometry of this line element establishes that the motion of the particle can occur on the surface of a cone or an anti--cone. As a consequence of the nontrivial topology of the cone and also because of two--dimensional confinement, the geometric potential should be taken into account. At first, we establish the conditions for the particle describing a circular path in such a context. Because of the presence of the geometric potential, which contains a singular term, we use the self--adjoint extension method in order to describe the dynamics in all space including the singularity. Expressions are obtained for the bound state energies and wave functions.
Quantum motion of a point particle in the presence of the Aharonov-Bohm potential in curved space
NASA Astrophysics Data System (ADS)
Silva, Edilberto O.; Ulhoa, Sérgio C.; Andrade, Fabiano M.; Filgueiras, Cleverson; Amorim, R. G. G.
2015-11-01
The nonrelativistic quantum dynamics of a spinless charged particle in the presence of the Aharonov-Bohm potential in curved space is considered. We chose the surface as being a cone defined by a line element in polar coordinates. The geometry of this line element establishes that the motion of the particle can occur on the surface of a cone or an anti-cone. As a consequence of the nontrivial topology of the cone and also because of two-dimensional confinement, the geometric potential should be taken into account. At first, we establish the conditions for the particle describing a circular path in such a context. Because of the presence of the geometric potential, which contains a singular term, we use the self-adjoint extension method in order to describe the dynamics in all space including the singularity. Expressions are obtained for the bound state energies and wave functions.
Bruno, Patrick
2012-06-15
The (Berry-Aharonov-Anandan) geometric phase acquired during a cyclic quantum evolution of finite-dimensional quantum systems is studied. It is shown that a pure quantum state in a (2J+1)-dimensional Hilbert space (or, equivalently, of a spin-J system) can be mapped onto the partition function of a gas of independent Dirac strings moving on a sphere and subject to the Coulomb repulsion of 2J fixed test charges (the Majorana stars) characterizing the quantum state. The geometric phase may be viewed as the Aharonov-Bohm phase acquired by the Majorana stars as they move through the gas of Dirac strings. Expressions for the geometric connection and curvature, for the metric tensor, as well as for the multipole moments (dipole, quadrupole, etc.), are given in terms of the Majorana stars. Finally, the geometric formulation of the quantum dynamics is presented and its application to systems with exotic ordering such as spin nematics is outlined. PMID:23004240
Hou, Dong; Xu, RuiXue; Zheng, Xiao; Wang, Shikuan; Wang, Rulin; Ye, LvZhou; Yan, YiJing
2015-03-14
Several recent advancements for the hierarchical equations of motion (HEOM) approach are reported. First, we propose an a priori estimate for the optimal number of basis functions for the reservoir memory decomposition. Second, we make use of the sparsity of auxiliary density operators (ADOs) and propose two ansatzs to screen out all the intrinsic zero ADO elements. Third, we propose a new truncation scheme by utilizing the time derivatives of higher-tier ADOs. These novel techniques greatly reduce the memory cost of the HEOM approach, and thus enhance its efficiency and applicability. The improved HEOM approach is applied to simulate the coherent dynamics of Aharonov–Bohm double quantum dot interferometers. Quantitatively accurate dynamics is obtained for both noninteracting and interacting quantum dots. The crucial role of the quantum phase for the magnitude of quantum coherence and quantum entanglement is revealed.
Asher Yahalom
2010-05-21
Variational principles for magnetohydrodynamics were introduced by previous authors both in Lagrangian and Eulerian form. In previous works [1] Yahalom & Lynden-Bell and later Yahalom [2] introduced a simpler Eulerian variational principle from which all the relevant equations of Magnetohydrodynamics can be derived. The variational principles were given in terms of four independent functions for non-stationary flows and three independent functions for stationary flows. This is less than the seven variables which appear in the standard equations of magnetohydrodynamics which are the magnetic field, the velocity field and the density . In the case that the magnetohydrodynamic flow has a non trivial topology such as when the magnetic lines are knotted or magnetic and stream lines are knotted, some of the functions appearing in the Lagrangian are non-single valued. Those functions play the same rule as the phase in the Aharonov-Bohm celebrated effect [3].
A. V. Ghazaryan; A. P. Djotyan; K. Moulopoulos; A. A. Kirakosyan
2011-05-30
We analytically solve the problem of an exciton (with particles interacting by a delta potential) in a one-dimensional quantum ring in the presence of an Aharonov-Bohm flux. By following a more straightforward method than in earlier works we determine the energy spectrum and the associated eigenfunctions together with other physical properties of the system in closed analytical forms. After finding the energy spectra of the exciton in this system, we then calculate the dynamic linear electric polarizability and the absorption coefficients; we find that the magnetic flux changes the values of the absorption coefficients dramatically and that by changing the value of magnetic flux parameter from 0 to 0.5 dark exciton states states transform to bright ones and vice versa.
NASA Astrophysics Data System (ADS)
Hou, Dong; Wang, Shikuan; Wang, Rulin; Ye, LvZhou; Xu, RuiXue; Zheng, Xiao; Yan, YiJing
2015-03-01
Several recent advancements for the hierarchical equations of motion (HEOM) approach are reported. First, we propose an a priori estimate for the optimal number of basis functions for the reservoir memory decomposition. Second, we make use of the sparsity of auxiliary density operators (ADOs) and propose two ansatzs to screen out all the intrinsic zero ADO elements. Third, we propose a new truncation scheme by utilizing the time derivatives of higher-tier ADOs. These novel techniques greatly reduce the memory cost of the HEOM approach, and thus enhance its efficiency and applicability. The improved HEOM approach is applied to simulate the coherent dynamics of Aharonov-Bohm double quantum dot interferometers. Quantitatively accurate dynamics is obtained for both noninteracting and interacting quantum dots. The crucial role of the quantum phase for the magnitude of quantum coherence and quantum entanglement is revealed.
Fano effect in the Andreev reflection of the Aharonov-Bohm-Fano ring with Majorana bound states
NASA Astrophysics Data System (ADS)
Jiang, Cui; Zheng, Yi-Song
2015-06-01
The Andreev reflection in an Aharonov-Bohm-Fano ring induced by Majorana bound states (MBSs) is theoretically investigated. We find that compared with the Fano effect in the normal electron tunneling process, the Fano effect here is more determined by the structural parameters, i.e., the quantum dot level, the dot-MBS coupling, and the dot-MBS and MBS-lead couplings. By transforming the ring into its Nambu representation, we present a comprehensive analysis about the quantum interference in the Andreev reflection, and then explain the reason for the occurrence of the Fano effect. These results will be helpful for understanding the quantum interference in the MBS-assisted Andreev reflection.
NASA Astrophysics Data System (ADS)
Roy, Bidisha; Ji, Haojie; Dhomkar, Siddharth; Cadieu, Fred J.; Peng, Le; Moug, Richard; Tamargo, Maria C.; Kuskovsky, Igor L.
2013-02-01
A spectral analysis of the Aharonov-Bohm (AB) oscillations in photoluminescence intensity was performed for stacked type-II ZnTe/ZnSe quantum dots (QDs) fabricated within multilayered Zn-Se-Te system with sub-monolayer insertions of Te. Robust AB oscillations allowed for fine probing of distinguishable QDs stacks within the ensemble of QDs. The AB transition magnetic field, B AB , changed from the lower energy side to the higher energy side of the PL spectra revealing the presence of different sets of QDs stacks. The change occurs within the spectral range, where the contributing green and blue bands of the spectra overlapped. "Bundling" in lifetime measurements is seen at transition spectral regions confirming the results.
Neven Simicevic
2009-09-14
The time-dependent Dirac equation is solved using the three-dimensional Finite Difference-Time Domain (FDTD) method. The dynamics of the electron wave packet in a vector potential is studied in the arrangements associated with the Aharonov-Bohm effect. The solution of the Dirac equation showed a change in the velocity of the electron wave packet even in a region where no forces acted on the electron. The solution of the Dirac equation agreed with the prediction of classical dynamics under the assumption that the dynamics was defined by the conservation of generalized or canonical momentum. It was also shown that in the case when the magnetic field was not zero, the conservation of generalized or canonical momentum was equivalent to the action of the Lorentz force.
Schütz, G; Rembold, A; Pooch, A; Prochel, H; Stibor, A
2015-11-01
We propose an experiment for the first proof of the type I electric Aharonov-Bohm effect in an ion interferometer for hydrogen. The performances of three different beam separation schemes are simulated and compared. The coherent ion beam is generated by a single atom tip (SAT) source and separated by either two biprisms with a quadrupole lens, two biprisms with an einzel-lens or three biprisms. The beam path separation is necessary to introduce two metal tubes that can be pulsed with different electric potentials. The high time resolution of a delay line detector allows to work with a continuous ion beam and circumvents the pulsed beam operation as originally suggested by Aharonov and Bohm. We demonstrate that the higher mass and therefore lower velocity of ions compared to electrons combined with the high expected SAT ion emission puts the direct proof of this quantum effect for the first time into reach of current technical possibilities. Thereby a high detection rate of coherent ions is crucial to avoid long integration times that allow the influence of dephasing noise from the environment. We can determine the period of the expected matter wave interference pattern and the signal on the detector by determining the superposition angle of the coherent partial beams. Our simulations were tested with an electron interferometer setup and agree with the experimental results. We determine the separation scheme with three biprisms to be most efficient and predict a total signal acquisition time of only 80s to measure a phase shift from 0 to 2? due to the electric Aharonov-Bohm effect. PMID:26188995
Numazaki, Kazuya; Imai, Hiromitsu; Morinaga, Atsuo
2010-03-15
The second-order Zeeman effect of the sodium clock transition in a weak magnetic field of less than 50 {mu}T was measured as the scalar Aharonov-Bohm phase by two-photon stimulated Raman atom interferometry. The ac Stark effect of the Raman pulse was canceled out by adopting an appropriate intensity ratio of two photons in the Raman pulse. The Ramsey fringes for the pulse separation of 7 ms were obtained with a phase uncertainty of {pi}/200 rad. The nondispersive feature of the scalar Aharonov-Bohm phase was clearly demonstrated through 18 fringes with constant amplitude. The Breit-Rabi formula of the sodium clock transition was verified to be {Delta}{nu}=(0.222{+-}0.003)x10{sup 12}xB{sup 1.998{+-}0.004} in a magnetic field of less than 50 {mu}T.
Thiago Prudencio
2015-07-02
Generation of Aharonov-Bohm (AB) phase has achieved a state-of-the-art in mesoscopic systems with manipulation and control of the AB effect. The possibility of transfer information enconded in such systems to light increases the possible scenarios where the information can be manipulated and transfered. In this paper we discuss a bit-enconding of AB phases and propose a quantum transfer of the AB phase generated in a topological spin transistor (TST) to coherent state superposition in high-Q cavity. We demonstrate that the AB phase generated in the TST can be stored in a non-classical state of light, a coherent state superposition, by interacting dispersivelly the spin state carrying the AB phase with the cavity state initially in a coherent state. We also discuss the storage of bits enconded by AB phases in high-Q and multimode cavities.
2012-01-01
Using the nonequilibrium Green’s function method, we theoretically study the Andreev reflection(AR) in a four-terminal Aharonov-Bohm interferometer containing a coupled double quantum dot with the Rashba spin-orbit interaction (RSOI) and the coherent indirect coupling via two ferromagnetic leads. When two ferromagnetic electrodes are in the parallel configuration, the spin-up conductance is equal to the spin-down conductance due to the absence of the RSOI. However, for the antiparallel alignment, the spin-polarized AR occurs resulting from the crossed AR (CAR) and the RSOI. The effects of the coherent indirect coupling, RSOI, and magnetic flux on the Andreev-reflected tunneling magnetoresistance are analyzed at length. The spin-related current is calculated, and a distinct swap effect emerges. Furthermore, the pure spin current can be generated due to the CAR when two ferromagnets become two half metals. It is found that the strong RSOI and the large indirect coupling are in favor of the CAR and the production of the strong spin current. The properties of the spin-related current are tunable in terms of the external parameters. Our results offer new ways to manipulate the spin-dependent transport. PMID:23228047
R. Y. Chiao
2012-06-23
The flux as measured by the Josephson effect in a SQUID-like configuration with a ferromagnetic core inserted into its center, is shown to be sensitive to the vector potential arising from the central ferromagnetic core, even when the core is covered with a superconducting material that prevents any magnetic field lines from ever reaching the perimeter of the SQUID-like configuration. This leads to a macroscopic, Aharonov-Bohm-like effect that is observable in an asymmetric hysteresis loop in the response of the SQUID-like configuration to an externally applied magnetic field.
Raymond Chiao
2012-05-28
A novel kind of nonlocal, macroscopic Aharonov-Bohm effect involving two topologically linked superconducting rings made out of two different materials, namely, lead and tin, is suggested for experimental observation, in which the lead ring is a torus containing a core composed of permanently magnetized ferromagnetic material. It is predicted that the remnant fields in a hysteresis loop induced by the application of a magnetic field imposed by a large external pair of Helmholtz coils upon the tin ring, will be asymmetric with respect to the origin of the loop. An appendix based on Feynman's path-integral principle is the basis for these predictions.
NASA Astrophysics Data System (ADS)
Vaidman, Lev; Dennis, Mark; Popescu, Sandu
2010-01-01
This is a call for contributions to a special issue of Journal of Physics A: Mathematical and Theoretical dedicated to the subject of quantum phases and highlighting the impact of the discovery of the Aharonov--Bohm effect and of the Berry phase across physics. Researchers working in the area are invited to submit papers of original research to this issue. Editorial policy The Editorial Board has invited Lev Vaidman, Mark Dennis and Sandu Popescu to serve as Guest Editors for the special issue. The criteria for acceptance of contributions are as follows: Contributions will be refereed and processed according to the usual procedure and high standards of the journal. Papers should be original and should contain substantial new results. All contributions will be refereed and processed according to the usual procedure of the journal. Papers should report original and significant research that has not already been published. Guidelines for preparation of contributions The DEADLINE for contributed papers will be 1 February 2010. This deadline will allow the special issue to appear in September 2010. Advice on publishing your work in Journal of Physics A: Mathematical and Theoretical www.iop.org/Journals/jphysa. Contributions to the special issue should be submitted electronically, if possible, by web upload at www.iop.org/Journals/jphysa, or by email to jphysa@iop.org, quoting 'JPhysA Special Issue— Quantum Phases'. Submissions should ideally be in standard LaTeX form. Please see the website for further information on electronic submissions. Authors unable to submit electronically may send hard-copy contributions to: Publishing Administrators, Journal of Physics A, IOP Publishing, Dirac House, Temple Back, Bristol BS1 6BE, UK. Please quote 'JPhysA Special Issue— Quantum Phases'. All contributions should be accompanied by a read-me file or covering letter giving the postal and e-mail addresses for correspondence. The Publishing Office should be notified of any subsequent change of address. This special issue will be published in the paper and online version of the journal.
Timothy H. Boyer
2005-06-23
The classical electromagnetic interaction of a point charge and a magnet is discussed by first calculating the interaction of point charge with a simple model magnetic moment and then suggesting a multiparticle limit. The Darwin Lagrangian is used to analyze the electromagnetic behavior of the model magnetic moment (composed of two oppositely charged particles of different mass in an initially circular orbit) interacting with a passing point charge. The changing mangetic moment is found to put a force back on a passing charge; this force is of order 1/c^2 and depends upon the magnitude of the magnetic moment. It is suggested that in the limit of a multiparticle magnetic toroid, the electric fields of the passing charge are screened out of the body of the magnet while the magnetic fields penetrate into the magnet. This is consistent with our understanding of the penetration of electromagnetic velocity fields into ohmic conductors. Conservation laws are discussed. The work corresponds to a classical electromagnetic analysis of the interaction which is basic to understanding the controversy over the Aharonov-Bohm and Aharonov-Casher phase shifts and represents a refutation of the suggestions of Aharonov, Pearle, and Vaidman.
Aharonov-Bohm phases in a quantum LC circuit
Cao, ChunJun; Zhitnitsky, Ariel R
2015-01-01
We study novel types of contributions to the partition function of the Maxwell system defined on a small compact manifold. These contributions, often not addressed in the perturbative treatment with physical photons, emerge as a result of tunneling transitions between topologically distinct but physically identical vacuum winding states. These new terms give an extra contribution to the Casimir pressure, yet to be measured. We argue that this effect is highly sensitive to a small external electric field, which should be contrasted with the conventional Casimir effect where the vacuum photons are essentially unaffected by any external field. Furthermore, photons will be emitted from the vacuum in response to a time-dependent electric field, similar to the dynamical Casimir effect in which real particles are radiated from the vacuum due to the time-dependent boundary conditions. We also propose an experimental setup using a quantum LC circuit to detect this novel effect. We expect physical electric charges to a...
The Dynamical Mechanism of the Aharonov-Bohm Effect
R. F. Wang
2007-05-28
In this paper, it is emphasized that the dynamical cause for the A-B effect is the superimposed energy between the magnetic field produced by the moving charges and that in the solenoid, instead of the existence of the vector potential. If such a superposition between the magnetic fields can be eliminated, the A-B effect should not be observed any more. To verify this viewpoint, a new experimental method using a SQUID is suggested in this paper.
Detecting Noncommutative Phase Space by Aharonov-Bohm Effect
Shi-Dong Liang; Haoqi Li; Guang-Yao Huang
2015-02-02
Noncommutative phase space plays an essential role in particle physics and quantum gravity at the Planck scale. However, direct experimental evidence or observation to demonstrate the existence of noncommutative phase space is still lacking.We study a quantum ring in noncommutative phase space based on the Seiberg-Witten map and give the effective magnetic potential and field coming from the noncommutative phase space, which induces the persistent current in the ring. We introduce two variables as two signatures to detect the noncommutative phase space and propose an experimental scheme to detect the noncommutative phase space as long as we measure the persistent current and the external magnetic flux.
Observation of two-particle Aharonov-Bohm interference
NASA Astrophysics Data System (ADS)
Neder, Izhar; Ofek, Nissim; Chung, Yunchul; Heiblum, Moty; Mahalu, Diana; Umansky, Vladimir
2008-03-01
Nature 448, 333-337 (19 July 2007) We report the first observation of quantum interference between two independent & non-interacting electrons in a unique interferometer proposed by Yurke et. al. [1] & Samuelsson et. al. [2]. The interference fringes were observed only in the joint probability of electrons arrival at two different drains; hence being the quantum analogue to the Hanbury Brown & Twiss (HBT) experiment with classical waves [3]. This, sought after, counter intuitive effect, is a direct result of the quantum exchange statistics of identical quantum particles. Our observation is a signature of orbital entanglement between two independent electrons, even tough they never interacted with each other. [1] B. Yurke & D. Stoler, Phys. Rev. A46, 2229-2234 (1992) [2] P. Samuelsson, E. V. Sukhorukov & M. Buttiker, Phys. Rev. Lett. 92, 02685 (2004). [3] R. Hanbury Brown & R. Q. Twiss, Phil. Mag. 45, 663-682 (1954).
THE CONTRIBUTION OF AZO DYES TO THE MUTAGENIC ACTIVITY OF THE CRISTAIS RIVER
To verify if compounds within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a ...
AZO DYES ARE MAJOR CONTRIBUTORS TO THE MUTAGENIC ACTIVITY DETECTED IN THE CRISTAIS RIVER WATERS
To determine if compounds from a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water T...
In order to verify if dyestuffs within an effluent of a textile industry was contributing to the systematic mutagenicity detected in the Cristais River, within the metropolitan region of Sao Paulo, mutagenic samples of the industrial effluent, crude water, and treated silt of the...
Interaction between a moving electron and magnetic flux in Aharonov-Bohm effect
Wang Rui-Feng
2013-12-21
The back-action exerted by the moving electron on the magnetic flux in the A-B effect is analyzed. It is emphasized that a reasonable interpretation on the A-B effect should be consistent with the uncertain principle. If the back-action on the magnetic flux is reduced to zero, the A-B effect should not be observed, even through the vector potential still exists in space. To verify this interpretation, a new experimental scheme is proposed in this paper.
Breaking of phase symmetry in nonequilibrium Aharonov-Bohm oscillations through a quantum dot
Ihn, Thomas
-particle picture3 and is, in fact, a manifestation of more general linear-response Onsager-Büttiker symmetries.4 is highly nonmonotonous. In particu- lar, i the oscillations indeed remain symmetric up to the onset of i
"Level Curvature" Distribution for Diffusive Aharonov-Bohm Systems: analytical results
Yan V. Fyodorov; H-J. Sommers
1994-12-24
We calculate analytically the distributions of "level curvatures" (LC) (the second derivatives of eigenvalues with respect to a magnetic flux) for a particle moving in a white-noise random potential. We find that the Zakrzewski-Delande conjecture is still valid even if the lowest weak localization corrections are taken into account. The ratio of mean level curvature modulus to mean dissipative conductance is proved to be universal and equal to $2\\pi$ in agreement with available numerical data.
Comment on "Role of potentials in the Aharonov-Bohm effect"
NASA Astrophysics Data System (ADS)
Aharonov, Yakir; Cohen, Eliahu; Rohrlich, Daniel
2015-08-01
Are the electromagnetic scalar and vector potentials dispensable? Vaidman [Phys. Rev. A 86, 040101(R) (2012)], 10.1103/PhysRevA.86.040101 has suggested that local interactions of gauge-invariant quantities, e.g., magnetic torques, suffice for the description of all quantum electromagnetic phenomena. We analyze six thought experiments that challenge this suggestion. All of them have explanations in terms of local interactions of gauge-dependent quantities, and, in addition, some have explanations in terms of nonlocal interactions of gauge-invariant quantities. We claim, however, that two of our examples have no gauge-invariant formal description and that, in general, no local description can dispense with electromagnetic potentials.
AHARONOV-BOHM-TYPE EFFECTS IN ANTIDOT ARRAYS AND THEIR DECOHERENCE
Katsumoto, Shingo
, by periodic orbit theory. For this reason, it is customary to call the effect AB-"type" oscillation so, AKIRA ENDO, SHINGO KATSUMOTO AND YASUHIRO IYE Institute for Solid State Physics, University of Tokyo, 5 of a ring-shaped sample at low temperatures as a function of external magnetic field. It is customary
Exciton storage in type-II quantum dots using the optical Aharonov-Bohm effect
Climente, Juan I.; Planelles, Josep
2014-05-12
We investigate the bright-to-dark exciton conversion efficiency in type-II quantum dots subject to a perpendicular magnetic field. To this end, we take the exciton storage protocol recently proposed by Simonin and co-workers [Phys. Rev. B 89, 075304 (2014)] and simulate its coherent dynamics. We confirm the storage is efficient in perfectly circular structures subject to weak external electric fields, where adiabatic evolution is dominant. In practice, however, the efficiency rapidly degrades with symmetry lowering. Besides, the use of excited states is likely unfeasible owing to the fast decay rates. We then propose an adaptation of the protocol which does not suffer from these limitations.
NASA Astrophysics Data System (ADS)
Neder, Izhar
2010-03-01
The two-particle AB experiment proposed by Yurke et. al. [1] and Samuelsson et. al. [2], was realized recently in a mesoscopic device in the quantum Hall effect regime. It was the first observation of quantum interference oscillations between two independent non-interacting particles. The interference fringes were observed only in the joint probability of electrons arrival at two different drains; hence being the quantum analogue to the Hanbury Brown and Twiss experiment with classical waves [3]. This counter intuitive effect is a direct result of the quantum exchange statistics of identical quantum particles. The experimental details and results will be discussed in the light of the theoretical effort to interpret this observation as a signature of orbital entanglement between the two independent electrons, even tough they never interacted with each other. New difficulties regarding the finite temperature and imperfect visibility were resolved only recently, in a non- trivial way. [4pt] [1] B. Yurke D. Stoler, Phys. Rev. A46, 2229-2234 (1992) [0pt] [2] P. Samuelsson, E. V. Sukhorukov, M. Buttiker, Phys. Rev. Lett. 92, 02685 (2004). [0pt] [3] R. Hanbury Brown, R. Q. Twiss, Phil. Mag. 45, 663-682 (1954).
Goldman, Vladimir J.
by lift-off, Figs. 1(a) and 1(b). Samples, mounted on sapphire substrates with In metal (servesGaAs=GaAs heterojunctions. After a shallow 140 nm wet etching, Au=Ti gate metal was de- posited in etch trenches, followed
Kouznetsov, Dmitrii
in Annular Cylindrical Boxes E. Ley-Koo1¤, G. Villa-Torres1¤, and D. Kouznetsov2 1 Instituto de Fi an annular cylindrical box and in the presence of an axial uniform magnetic field is solved in two an annular cylindrical box was analyzed in [6]. The A-B effect on the Landau states of an electron inside
Chords: Em 022000 Em Em Em Em C C C C
Reiners, Peter W.
Verse 1 Chorus Verse 2 Chorus Verse 3 Chords: Em 022000 C 035553 G 320002 F 133211 Intro: Em Em Em Em C C C C Em Em Em Em C C C C Em Em Em Em C C C C Em Em Em Em C C C C Verse: Em Em Em Em C C C C G G G G G G G G Em Em Em Em C C C C G G G G G G G G Em Em Em Em C C C C G G G G G G G G Em Em Em Em C C
15 November 2000 J. Phys. A: Math. Gen. 35 (2001) 69816986. quant-ph/0105087
Meyer, David A.
2001-01-01
TRANSFORMATIONS TO TOPOLOGY COMPUTATION IN QUANTUM LATTICE GAS AUTOMATA David A. Meyer Project in Geometry the rule for minimal coupling to an arbitrary external electromagnetic field. We develop the Aharonov-Bohm numbers: 03.65.Lx, 03.65.Vf, 03.65.Pm. KEY WORDS: quantum lattice gas; quantum computation; Aharonov-Bohm
15 November 2000 J. Phys. A: Math. Gen. 35 (2001) 6981--6986. quantph/0105087
Meyer, David A.
2001-01-01
; AharonovBohm e#ect; spatial topology. 1 #12; Topology computation David A. Meyer Quantum lattice gas TRANSFORMATIONS TO TOPOLOGY COMPUTATION IN QUANTUM LATTICE GAS AUTOMATA David A. Meyer Project in Geometry the rule for minimal coupling to an arbitrary external electromagnetic field. We develop the AharonovBohm
160 nature physics | VOL 6 | MARCH 2010 | www.nature.com/naturephysics news & views
Loss, Daniel
. When Yakir Aharonov and David Bohm discovered in 1959 that the quantum- mechanical motion of a charged). T he meeting celebrating the fiftieth anniversary of the AharonovBohm effect and the twenty in physics. It was also home to Robert Chambers's first experimental demonstration of the AharonovBohm
Optical analog of the Iordanskii force in a Bose-Einstein condensate
Leonhardt, U.; Oehberg, P.
2003-05-01
A vortex in a Bose-Einstein condensate generates the optical analog of the Aharonov-Bohm effect when illuminated with slow light. In contrast to the original Aharonov-Bohm effect the vortex will exchange forces with the light that leads to a measurable motion of the vortex.
Maxwell Duality, Lorentz Invariance, and Topological Phase
NASA Technical Reports Server (NTRS)
Dowling, J.; Williams, C.; Franson, J.
1999-01-01
We discuss the Maxwell electromagnetic duality relations between the Aharonov-Bohm, Aharonov-Casher, and He-McKellar-Wilkens topological phases, which allows a unified description of all three phenomena.
Two Further Experiments on Electron Interference
ERIC Educational Resources Information Center
Matteucci, G.; Pozzi, G.
1978-01-01
Presents the results of two experiments concerning the phenomena of the interference of probabilities and of the so called Aharonov-Bohm effect. An electron biprism and a standard electron microscope have been used for the experiments. (Author/GA)
Jeanjean, Louis
-locality that become widely recognized when he, together with David Bohm, shocked the world of physics in the late fifties with the introduction of the so-called AharonovBohm (AB) effect [1]. Their paper discussed
COVER IMAGE The TomonagaLuttinger liquid
Loss, Daniel
the wave David Gevaux 749 Oxide interfaces: Moment of magnetism Andrew J. Millis 750 Glass physics that these fields can give rise to an analogue of the Aharonov Bohm effect, a phenomenon that might be used
Lai, Ying-Cheng
and David K. Ferry2 1 Department of Mathematics and SSERC, Arizona State University, Tempe, Arizona 85287 2 to such phenomena as conductance fluctuations and th eAharonov-Bohm effect [1,2]. The aim of this Letter
CS4670/PH4670, Quantum Computing (4-0) Ted Huffmire and Jim Luscombe
Feynman, Peter Shor, David Deutsch 2 Foundational Physics of Quantum Computing I History of Light; Photons-Einstein Condensation; Meissner Effect, Josephson Effect, Aharonov- Bohm Effect; Nuclear Magnetic Resonance (NMR
Gauge invariance and the detection of gravitational radiation
David Garfinkle
2005-11-16
The detection of gravitational radiation raises some subtle issues having to do with the coordinate invariance of general relativity. This paper explains these issues and their resolution by using an analogy with the Aharonov-Bohm effect of quantum mechanics.
nature physics | VOL 6 | MARCH 2010 | www.nature.com/naturephysics 157 research highlights
Loss, Daniel
Aharonov and David Bohm proposed that a charged particle in a region of zero electric and zero magnetic things around and, envisaging a cosmic string as an oscillating solenoid in a vacuum, show that AharonovBohm
NANO-SQUID SUSCEPTOMETRY AND FLUCTUATION EFFECTS IN SUPERCONDUCTING RINGS
Moler, Kathryn A.
of Doctor of Philosophy. (David Goldhaber-Gordon) Approved for the University Committee on Graduate Studies smear out the Little-Parks effect, where Tc is reduced due to the Aharonov-Bohm phase winding energy
2011-12 FACULTY RESEARCH AWARD PROGRAM (FRAP) RECIPIENTS
Alexandrova, Ivana
Professor, Department of Math & Statistics "Scattering Theory, Semi Classical Analysis and the Aharonov-Bohm" Category A - $9,970 David Hochfelder, Assistant Professor, Department of History "Creating the Ownership
PHYSICAL REVIEW B 85, 115415 (2012) Smooth gauge for topological insulators
Vanderbilt, David
2012-01-01
* and David Vanderbilt Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 the systematic description of many observable effects of purely geometric origin, such as the Aharonov-Bohm
Interference in the presence of dissipation Baruch Horovitz1 and Pierre Le Doussal2
Horovitz, Baruch
mesoscopic rings embed- ded on various surfaces where Aharonov-Bohm AB oscil- lations can be measured,1 to induce dissipation on the dipole. We then solve these systems by a variational method. We test our method
Quantum mechanics : Intellectually delicious;
Peshkin, M.; Vaidman, L.
2010-03-01
It is 50 years since the discovery of the Aharonov-Bohm effect, and 25 years since that of the Berry phase. A celebration of this double anniversary at the University of Bristol made evident that these discoveries still offer much food for thought. The meeting celebrating the fiftieth anniversary of the Aharonov-Bohm effect and the twenty-fifth anniversary of the Berry phase was held on 14-15 December 2009 in the historic H. H.
Topological suppression of optical tunneling in a twisted annular fiber
Ornigotti, M.; Valle, G. Della; Gatti, D.; Longhi, S.
2007-08-15
A classical wave-optics analog of topological (Aharonov-Bohm) suppression of tunneling in a double-well potential on a ring threaded by a magnetic flux is proposed. The optical system consists of a uniformly twisted optical fiber with a structured annular core, in which the fiber twist mimics the role of the magnetic flux in the corresponding quantum-mechanical problem. Light waves trapped in the annular core of the fiber experience an additional topological (Aharonov-Bohm) phase, which may lead to the destruction of optical tunneling at certain values of the twist rate.
Not Available
1993-07-01
It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.
Falta de investimento prejudica sector em Portugal
Instituto de Sistemas e Robotica
, "falta verdadeiro capital de risco investidor em ciências da vida em ge- ral, e em biotecnologia em Investimento Menos de metade dos investidores em biotecnologia recuperam o seu Investimento. Mas em 2013, pela
Suppression of decoherence in a graphene monolayer ring
Smirnov, D. Rode, J. C.; Haug, R. J.
2014-08-25
The influence of high magnetic fields on coherent transport is investigated. A monolayer graphene quantum ring is fabricated and the Aharonov-Bohm effect is observed. For increased magnitude of the magnetic field, higher harmonics appear. This phenomenon is attributed to an increase of the phase coherence length due to reduction of spin flip scattering.
arXiv:cond-mat/0504756v226Sep2005 The Multimode Conductance Formula
Cohen, Doron
of an electro motive force (EMF) such that the voltage drop is concentrated across a segment of the device. More EMF by changing in time an Aharonov-Bohm magnetic flux, or we can change the potential in some region. The current is measured via the section x = x1. The Electro motive force (EMF) is realized by time dependent
Colloquium: Artificial gauge potentials for neutral atoms Jean Dalibard* and Fabrice Gerbier
Dalibard, Jean
Colloquium: Artificial gauge potentials for neutral atoms Jean Dalibard* and Fabrice Gerbier at the basis of this artificial (synthetic) magnetism are presented. The corresponding Aharonov-Bohm phase of the atom-laser interaction. Some manifestations of artificial magnetism for a cold quantum gas
arXiv:cond-mat/0412664v123Dec2004 Quantum Transport in Semiconductor Nanostructures
Nikolic, Branislav K.
. Boundary scattering 12 2. Magneto size effects 13 B. Weak localization 15 1. Coherent backscattering 16 2. Magnetoconductance fluctuations 25 4. Experiments 28 D. Aharonov-Bohm effect 30 E. Electron-electron interactions 32 as a transmission problem 44 1. Electron waveguide 44 2. Landauer formula 47 B. Quantum point contacts 49 1
PHYSICS 234, 235 QUANTUM MECHANICS I, II PHYSICS 234 QUANTUM MECHANICS I
. role of vector potential in QM B. AharonovBohm effect C. Landau levels D. Zeeman effect; Stark effect Experiment FranckHertz Experiment Electron Diffraction Normal and Anomalous Zeeman Effect The Compton Effect's inequalities [or cover at end of 234?], path integrals, quantum Hall effect, quantum computing LABORATORY
Goldbart, Paul M.
Operation of a superconducting nanowire quantum interference device with mesoscopic leads David Pekker, Alexey Bezryadin, David S. Hopkins, and Paul M. Goldbart Department of Physics, University oscillation of the device resistance, with a period not dominated by the Aharonov-Bohm effect through the area
The 30th Annual Chemical Physics
Le Roy, Robert J.
, November 7, 2014 -- P.M. EIT-1015 Chair: Marcel Nooijen 7:30 8:15 David Cory (University of Waterloo 8, 2014 A.M. EIT-1015 Chair: Pierre-Nicholas Roy 10:45 11:45 The Roger E. Miller Lecture : David) Magnetotransport in Aharonov-Bohm interferometers using numerically exact path integrals The Roger E. Miller
Lerner, David E.; Porter, J. R.
1974-01-01
. 1528, 456 (2013); 10.1063/1.4803644 Exact Green function for a Dirac particle in a weak gravitational plane wave field. Alternative path integral approach J. Math. Phys. 53, 072303 (2012); 10.1063/1.4736720 Gravitational Aharonov-Bohm effect due...
Remarks about Hardy inequalities on metric trees
Tomas Ekholm; Rupert L. Frank; Hynek Kovarik
2007-11-13
We find sharp conditions on the growth of a rooted regular metric tree such that the Neumann Laplacian on the tree satisfies a Hardy inequality. In particular, we consider homogeneous metric trees. Moreover, we show that a non-trivial Aharonov-Bohm magnetic field leads to a Hardy inequality on a loop graph.
ERIC Educational Resources Information Center
Matteucci, G.
2007-01-01
In the so-called electric Aharonov-Bohm effect, a quantum interference pattern shift is produced when electrons move in an electric field free region but, at the same time, in the presence of a time-dependent electric potential. Analogous fringe shifts are observed in interference experiments where electrons, travelling through an electrostatic…
Quantum Phase Transitions Josephson & Optical Lattices
Fominov, Yakov
corresponding to the extra boson is localized #12;Monte Carlo simulations S = t U , [1 - cos (i, - jQuantum Phase Transitions in Frustrated Josephson & Optical Lattices R o s a r i o F a z i o SISSA - Frustrated systems * Aharonov-Bohm cages in frustrated dice lattices M. Rizzi, V. Cataudella and R. Fazio PRB
Limits on guiding center and gyrokinetic plasma models in 3D magnetic fields
for Nuclear Science Massachusetts Institute of Technology Cambridge MA 02139-4307 PPPL Theory Seminar 12, a globally consistent definition may not exist! · In 2D slab (straight, uniform magnetic field lines to torsion is a real physical effect; appears in many areas (Aharonov-Bohm effect, Berry phase, related
Naujas Lietuvos Teritorijos Vertikali?j? Žem?s Plutos Judesi? Žem?lapis
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Šliaupa, Saulius; Anik?nien?, Asta
2009-01-01
Sudarytas naujas Lietuvos teritorijos dabartini? vertikali?j? Žem?s plutos judesi? grei?i? žem?lapis, judesiams modeliuoti taikant autori? pasi?lyt? metodik?. Metodika pagr?sta vertikali?j? judesi? reikšmi? ir teritorijos svarbiausi? georodikli? koreliacin?mis ir regresin?mis priklausomyb?mis, gautomis atlikus geodezinius matavimus. Dabartiniai vertikali?j? Žem?s plutos judesi? grei?iai Lietuvos teritorijoje yra nuo -3,5 iki +2,5 mm per metus. Intensyviausias Žem?s plutos kilimas ir didžiausia judesi? grei?i? gradient? kaita yra šiaur?s rytin?je Lietuvos dalyje, o grimzdimas - pietin?je ir pietvakarin?je srityse. Ištirtas pagal regresin? matematin? model? sudaryto žem?lapio patikimumas ir nustatyta, kad žem?lapio atitikimo pagal geodezini? matavim? rezultatus tikimyb? yra ne mažesn? nei 0,95.
Square billiard with a magnetic flux
R. Narevich; R. E. Prange; Oleg Zaitsev
2000-03-06
Eigenstates and energy levels of a square quantum billiard in a magnetic field, or with an Aharonov-Bohm flux line, are found in quasiclassical approximation, that is, for high enough energy. Explicit formulas for the energy levels and wavefunctions are found. A number of interesting states are shown, together with their wavefunctions. Some states are diamagnetic, others paramagnetic, still others both dia- and paramagnetic. Some states are strongly localized. Related systems and possible experiments are briefly mentioned.
Quantum gates with topological phases
Ionicioiu, Radu
2003-09-01
We investigate two models for performing topological quantum gates with the Aharonov-Bohm (AB) and Aharonov-Casher (AC) effects. Topological one- and two-qubit Abelian phases can be enacted with the AB effect using charge qubits, whereas the AC effect can be used to perform all single-qubit gates (Abelian and non-Abelian) for spin qubits. Possible experimental setups suitable for a solid-state implementation are briefly discussed.
Topological phenomena in ultracold atomic gases
Price, Hannah
2013-10-08
, and to David Khmelnitskii for his wonderful graduate lectures. I am indebted to the unparalleled computing support of Michael Rutter and Daniel Corbett, who, together with our administrators over time: Tracey Ingham, Helen Verrechia and David Taylor, have kept... observable. It vanishes when both time-reversal and inversion symmetries are present. The Berry phase is similar to the Aharonov-Bohm phase, with the Berry curvature playing the role of a magnetic field in momentum space. Hereafter, we consider the two...
ESPECIAO ESPONTNEA EM POPULAES ESPACIALMENTE
de Aguiar, Marcus A. M.
público em geral. Em 1859 Charles Darwin deu passo fundamental para a solução desse problema com Charles Darwin a franchi le pas pour la solution de ce problème avec la publication de son oeuvre majeure do livro A origem das Espécies de Charles Darwin e muito se tem falado a respeito de teoria da
Identified EM Earthquake Precursors
NASA Astrophysics Data System (ADS)
Jones, Kenneth, II; Saxton, Patrick
2014-05-01
Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for recurrence, duration, and frequency response. At the Southern California field sites, one loop antenna was positioned for omni-directional reception and also detected a strong First Schumann Resonance; however, additional Schumann Resonances were absent. At the Timpson, TX field sites, loop antennae were positioned for directional reception, due to earthquake-induced, hydraulic fracturing activity currently conducted by the oil and gas industry. Two strong signals, one moderately strong signal, and approximately 6-8 weaker signals were detected in the immediate vicinity. The three stronger signals were mapped by a biangulation technique, followed by a triangulation technique for confirmation. This was the first antenna mapping technique ever performed for determining possible earthquake epicenters. Six and a half months later, Timpson experienced two M4 (M4.1 and M4.3) earthquakes on September 2, 2013 followed by a M2.4 earthquake three days later, all occurring at a depth of five kilometers. The Timpson earthquake activity now has a cyclical rate and a forecast was given to the proper authorities. As a result, the Southern California and Timpson, TX field results led to an improved design and construction of a third prototype antenna. With a loop antenna array, a viable communication system, and continuous monitoring, a full fracture cycle can be established and observed in real-time. In addition, field data could be reviewed quickly for assessment and lead to a much more improved earthquake forecasting capability. The EM precursors determined by this method appear to surpass all prior precursor claims, and the general public will finally receive long overdue forecasting.
2002 E.M. Aboulhamid 1 Methodology
Aboulhamid, El Mostapha
1 2002 E.M. Aboulhamid 1 Co-design Methodology and Synthesis Synthesis 2002 E.M. Aboulhamid 2 SystemC #12;2 2002 E.M. Aboulhamid 3 Introduction to SystemC 2002 E.M. Aboulhamid 4 C++ · C++ class executed #12;3 2002 E.M. Aboulhamid 5 C++ Language Standard Event-driven Simulation Events Processes Data
ONDAS em MEIOS DESORDENADOS Andre Nachbin, IMPA
Liu, I-Shih
ONDAS em MEIOS DESORDENADOS AndrÂ´e Nachbin, IMPA Ondas em Meios Desordenados Modelos EstocÂ´asticos e AplicaÂ¸c~oes,CBPF, 2007 AndrÂ´e Nachbin IMPA http://www.impa.br/nachbin #12;ONDAS em MEIOSÂ¸c~oes,CBPF, 2007 AndrÂ´e Nachbin IMPA http://www.impa.br/nachbin #12;ONDAS em MEIOS DESORDENADOS Pesquisa em 3
EPA LABORATORIES IMPLEMENT EMS PROGRAM
This paper highlights the breadth and magnitude of carrying out an effective Environmental Management System (EMS) program at the U.S. EPA's research and development laboratories. Federal research laboratories have unique operating challenges compared to more centralized industr...
Neskelbti Tarpukario Lietuvos Topografiniai Žem?lapiai
NASA Astrophysics Data System (ADS)
Girkus, Romualdas; Lukoševi?ius, Viktoras
2008-09-01
Nemaža publikacij? apie tarpukario Lietuvos teritorijos topografin? kartografavim? teikia tapa?i? informacij?, kad iki Antrojo pasaulinio karo pradžios sp?ta išleisti 92 M 1:25 000 ir 44 M 1:100 000 žem?lapius. Straipsnyje nagrin?jami 1920-1940 m. laikotarpiu sudaryti neskelbti ?vairi? Lietuvos teritorijos dali? topografiniai žem?lapiai: Var?nos artilerijos poligono M 1:25 000 žem?lapis (1925 m.), Gaiži?n? karinio poligono M 1:100 000 (1930 m. ?) ir M 1:50 000 (1932 m.) žem?lapiai, Kauno ?gulos šaudyklos M 1:10 000 žem?lapis (1933 m.), Pabrad?s karinio poligono M 1:25 000 žem?lapis (1940 m.), ŠVENTOJI - DARB?NAI M 1:100 000 žem?lapis (1939 m. ?). Iliustracijose pateikiami žem?lapi? fragmentai.
Populações estelares em galáxias HII
NASA Astrophysics Data System (ADS)
Westera, P.; Cuisinier, F.; Telles, E.; Kehrig, C.
2003-08-01
Analisamos o conteúdo estelar de 74 galáxias HII a partir do contínuo observado nos espectros ópticos dessas galáxias, utilizando métodos de síntese de população estelar. Descobrimos que todas as galáxias para as quais encontramos soluções contêm uma população estelar velha que domina a massa estelar, e numa maioria dessas também encontramos evidência de uma população de idade intermediaria além da geração jovem que está se formando agora. Concluímos que a formação estelar dessas galáxias se realiza em surtos individuais, Esses surtos são interrompidos por longos períodos de inatividade, com os primeiros consumindo a maior parte do gás. Sugerimos, portanto, que as galáxias HII sejam galáxias anãs normais flagradas em um período de surto.
REGIMENTO DO CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS, REA DE CONCENTRAO EM
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS, ÁREA DE CONCENTRAÇÂO EM COMBUSTÃO E PROPULSÃO TÍTULO I DOS OBJETIVOS DO CURSO Art. 1o A Área de Concentração em Combustão e Propulsão (PCP) do Curso de Pós-graduação em Engenharia e Tecnologia Espaciais (ETE) objetiva formar e
The European Mobile System (EMS)
NASA Technical Reports Server (NTRS)
Jongejans, A.; Rogard, R.; Mistretta, I.; Ananasso, F.
1993-01-01
The European Space Agency is presently procuring an L band payload in order to promote a regional European L band system coping with the specific needs of the European market. The payload, and the two communications systems to be supported, are described below. The potential market for EMS in Europe is discussed.
Sako, Yasuhito; Nakao, Minoru; Nakaya, Kazuhiro; Yamasaki, Hiroshi; Gottstein, Bruno; Lightowers, Marshall W.; Schantz, Peter M.; Ito, Akira
2002-01-01
The Echinococcus multilocularis protein Em18 is one of the most promising antigens for use in serodiagnosis of alveolar echinococcosis in human patients. Here we identify an antigenic relationship between Em18 and a 65-kDa immunodominant E. multilocularis surface protein previously identified as either EM10 or EmII/3. The NH2-terminal sequence of native Em18 was determined, revealing it to be a fragment of EM10. Experiments were undertaken to investigate the effect of proteinase inhibitors on the degradation of EM10 in crude extracts of E. multilocularis protoscoleces. Em18 was found to be the product of degradation of EM10 by cysteine proteinase. A recombinant Em18 (RecEm18, derived from 349K to 508K of EM10) was successfully expressed by using Escherichia coli expression system and then evaluated for use in serodiagnosis of alveolar echinococcosis. RecEm18 was recognized by 27 (87.1%) and 28 (90.3%) of 31 serum samples from clinically and/or pathologically confirmed alveolar echinococcosis patients by enzyme-linked immunosorbent assay and immunoblotting, respectively. Of 33 serum samples from cystic echinococcosis patients, 1 was recorded as having a weak positive reaction to RecEm18; however, none of the serum samples which were tested from neurocysticercosis patients (n = 10) or healthy people (n = 15) showed positive reactions. RecEm18 has the potential for use in the differential serodiagnosis of alveolar echinococcosis. PMID:12149326
Lietuvos teritorijos žem?s plutos deformacij? ir seismotektoninio potencialo ryšys
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Stanionis, Arminas; Levinskait?, Daiva
2010-01-01
Lietuvoje yra statini?, kelian?i? ekologinio pavojaus gr?sm? (Ignalinos atomin? elektrin?, Mažeiki? naftos perdirbimo ?mon?, chemijos gamyklos Jonavoje bei K?dainiuose ir pan.). Seisminiai ?vykiai gali sutrikdyti ši? ?moni? veikl? ir net lemti didel? pavoj? aplinkai, t. y. gali b?ti sukelta didel? aplinkos tarša chemin?mis bei radioaktyviosiomis medžiagomis. Seisminius ?vykius lemia teritorijos seismotektoninis potencialas. Seismotektoninis potencialas ir Žem?s plutos deformacijos yra tarpusavyje susij? rei\\vskiniai, kuriuos sukelia dažnai tie patys giluminiai procesai Žem?s gelm?se. Žem?s plutos deformacij? tyrimas yra vienas iš informacijos šaltini? prognozuojant teritorijos seismotektonin? aktyvum?. Straipsnyje nagrin?jamos Žem?s plutos horizontaliosios deformacijos, nustatomi Žem?s plutos ?tempi? poky?iai Lietuvos teritorijoje pagal GPS matavim? duomenis. Atlikus tyrimus pagal pateikiam? Žem?s plutos horizontali?j? deformacij? ir ?tempi? tyrimo metodik?, gauti nauji horizontali?j? deformacij? charakteristik? bei ?tempi? poky?i? rezultatai ir nustatytos j? s?sajos su seismotektoniniu potencialu.
School Budget Hold'em Facilitator's Guide
ERIC Educational Resources Information Center
Education Resource Strategies, 2012
2012-01-01
"School Budget Hold'em" is a game designed to help school districts rethink their budgeting process. It evolved out of Education Resource Strategies' (ERS) experience working with large urban districts around the country. "School Budget Hold'em" offers a completely new approach--one that can turn the budgeting process into a long-term visioning…
CURSO DE PS-GRADUAO EM METEOROLOGIA
CURSO DE PÓS-GRADUAÇÃO EM METEOROLOGIA Coordenador Acadêmico Dirceu Luis Herdies Membros do Conselho de Curso Luis Gustavo Gonçalves de Gonçalves José Antonio Marengo Orsini Clóvis Angeli Sansigolo Univ., 1969 Valdir Innocentini, Ph.D., Univ. of Reading, 1986 #12;2 CURSO DE PÓS-GRADUAÇÃO EM
CURSO DE PS-GRADUAO EM METEOROLOGIA
CURSO DE PÓS-GRADUAÇÃO EM METEOROLOGIA Coordenador Acadêmico Dirceu Luis Herdies Membros do Conselho de Curso Luis Gustavo Gonçalves de Gonçalves José Antonio Marengo Orsini Clóvis Angeli Sansigolo Innocentini, Ph.D., Univ. of Reading, 1986 #12;2 CURSO DE PÓS-GRADUAÇÃO EM METEOROLOGIA PROGRAMAÇÃO ANUAL DAS
EM international activities. February 1997 highlights
1997-02-01
EM International Highlights is a brief summary of on-going international projects within the Department of Energy`s Office of Environmental Management (EM). This document contains sections on: Global Issues, activities in Western Europe, activities in central and Eastern Europe, activities in Russia, activities in Asia and the Pacific Rim, activities in South America, activities in North America, and International Organizations.
Em que medida devem ser privados, em que medida devem ser pblicos o conhecimento e a informao?
Kuhlen, Rainer
Em que medida devem ser privados, em que medida devem ser pÃºblicos o conhecimento e a informaÃ§Ã£o? 1 TransparÃªncias com licenÃ§a Creative Commons Em que medida devem ser privados, em que medida devem ser pÃºblicos o as alternativas? codexKonstanz #12;Em que medida devem ser privados, em que medida devem ser pÃºblicos o
Romanov, Gennady; Hoff, Matthew; Li, Derun; Staples, John; Virostek, Steve; /LBNL
2012-05-09
Project X is a proposed multi-MW proton facility at Fermi National Accelerator Laboratory (FNAL). The Project X front-end would consist of an H- ion source, a low-energy beam transport (LEBT), a CW 162.5 MHz radio-frequency quadrupole (RFQ) accelerator, and a medium-energy beam transport (MEBT). Lawrence Berkeley National Laboratory (LBNL) and FNAL collaboration is currently developing the designs for various components in the Project X front end. This paper reports the detailed EM design of the CW 162.5 MHz RFQ that provides bunching of the 1-10 mA H- beam with acceleration from 30 keV to 2.1 MeV.
EM International, July 1994, Volume 2
Not Available
1994-10-01
The Office of Environmental Management (EM) at the Department of Energy (DOE) is seeking out and leveraging foreign technology, data, and resources in keeping with EM`s mandate to protect public health and the environment through the safe and cost-effective remediation of the Department`s nuclear weapons sites. EM works closely with foreign governments, industry, and universities to obtain innovative environmental technologies, scientific and engineering expertise, and operations experience that will support EM`s objectives. Where appropriate, these international resources are used to manage the more urgent risks at our sites, secure a safe workplace, help build consensus on critical issues, and strengthen our technology development program. Through international agreements EM engages in cooperative exchange of information, technology, and individuals. Currently, we are managing agreements with a dozen countries in Europe, Latin America, and Asia. These agreements focus on environmental restoration, waste management, transportation of radioactive wastes, and decontamination and decommissioning. This publication contains the following articles: in situ remediation integrated program; in-situ characterization and inspection of tanks; multimedia environmental pollutant assessment system (MEPAS); LLNL wet oxidation -- AEA technology. Besides these articles, this publication covers: EU activities with Russia; technology transfer activities; and international organization activities.
Abundâncias em estrelas de Bário
NASA Astrophysics Data System (ADS)
Allen, D. M.
2003-08-01
Estrelas de Bário apresentam linhas intensas de elementos produzidos pelo processos (ex: Ba, Y, Sr, Zr) e bandas intensas de CN, C2 e CH. A hipótese mais aceita sobre a origem deste grupo peculiar é a de que essas estrelas façam parte de sistemas binários, tendo recebido material enriquecido em elementos pesados da companheira mais evoluída. Apresentamos neste trabalho uma análise detalhada de uma amostra de estrelas desta classe, incluindo determinação de parâmetros atmosféricos e cálculo de abundâncias. As temperaturas efetivas foram determinadas a partir de dados fotométricos obtidos com o Fotrap instalado no telescópio Zeiss do LNA (Laboratório Nacional de Astrofísica) (B-V, V-I, R-I, V-R), e coletados na literatura nos catálogos Hipparcos (B-V), 2MASS (Two Micron All Sky Survey) (V-K) e The General Catalogue Photometric Data (sistema Geneva). Obtivemos uma faixa de temperaturas de 4400 £ Tef £ 6500. As metalicidades foram determinadas a partir de linhas de Fe I e Fe II, estando os resultados no intervalo -1 £ [Fe/H] £ +0.1. O log g foi determinado pelo equilíbrio de ionização e pela relação com a magnitude bolométrica, a temperatura e a massa, sendo os resultados na faixa 1.5 £ log g £ 4.5. As distâncias utilizadas foram determinadas com o auxílio das paralaxes Hipparcos, e as massas determinadas por modelos de isócronas. Os espectros utilizados foram obtidos com o espectrógrafo FEROS no Telescópio de 1,5m do ESO (European Southern Observatory). As abundâncias foram calculadas por meio de síntese espectral de linhas individuais incluindo elementos alfa, pico do Fe, s e r. Encontramos um excesso de elementos pesados em relação ao Fe, como esperado para estrelas de Bário.
VII SEMINRIO DE PESQUISAS EM ANDAMENTO DA PGET
Hanazaki, Natalia
.............................................................................................................................................................. 14 O mapeamento de conteúdos localizados no jogo Infamous 2: Uma análise baseada em corpus
CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM ENGENHARIA E GERENCIAMENTO DE SISTEMAS ESPACIAIS Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenadora da Área de;2 CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM ENGENHARIA E
Rural Emergency Medical Services (EMS) and Trauma
... funding section of this topic guide. Are there continuing education programs for EMS personnel? The National Highway Traffic ... provide information on licensing, testing, and certification. The Continuing Education Coordinating Board for Emergency Medical Services provides a ...
EMS Division Potential Benefits of Selected
For Systems Engineering Seminar at US Navy Post Graduate School Monterrey, CA August 18, 2005 Work supported coils are stationary; there are no rotating cold seals #12;EMS Division Advanced Homopolar Motor Concept
Tpicos em Processos Estocsticos: Eventos Raros,
Moreira, Carlos Gustavo
Software Livre/Gratuito - Alejandro C. Frery e Francisco Cribari-Neto · Espaços de Hardy no Disco Unitário Primeiro Curso sobre Teoria Ergódica com Aplicações - Krerley Oliveira · Uma Introdução à Simetrização em
Topological Properties of Linear Circuit Lattices
NASA Astrophysics Data System (ADS)
Albert, Victor V.; Glazman, Leonid I.; Jiang, Liang
2015-05-01
Motivated by the topologically insulating circuit of capacitors and inductors proposed and tested by Jia et al. [arXiv:1309.0878], we present a related circuit with fewer elements per site. The normal mode frequency matrix of our circuit is unitarily equivalent to the hopping matrix of a quantum spin Hall insulator, and we identify perturbations that do not backscatter the circuit's edge modes. The idea behind these models is generalized, providing a platform to simulate tunable and locally accessible lattices with arbitrary complex spin-dependent hopping of any range. A simulation of a non-Abelian Aharonov-Bohm effect using such linear circuit designs is discussed.
Topological feature and phase structure of QCD at complex chemical potential
NASA Astrophysics Data System (ADS)
Kashiwa, Kouji; Ohnishi, Akira
2015-11-01
The pseudo-critical temperature of the confinement-deconfinement transition and the phase transition surface are investigated by using the complex chemical potential. We can interpret the imaginary chemical potential as the Aharonov-Bohm phase, then the analogy of the topological order suggests that the Roberge-Weiss endpoint would define the pseudo-critical temperature. The behavior of the Roberge-Weiss endpoint at small real quark chemical potential is investigated with the perturbative expansion. The expected QCD phase diagram at complex chemical potential is presented.
Localization by interference: Square billiard with a magnetic flux
R. Narevich; R. E. Prange; Oleg Zaitsev
1999-03-11
Eigenstates and energy levels of a square quantum billiard in a magnetic field, or with an Aharonov-Bohm flux line, are found in quasiclassical approximation, that is, for high enough energy. Explicit formulas for the energy levels and wavefunctions are found. There are localized states, never before noticed in this well studied problem, whose localization is due to phase interference, even though there is no or negligible classical effect of the magnetic field. These and related states account almost entirely for the magnetic response in certain temperature ranges, and thus have a bearing on the experiments of Levy et al.
Thévenin equivalence in disorderless quantum networks
Cain, C. A.; Wu, C. H.
2015-01-14
We outline the procedure of extending the Thévenin equivalence principle for classical electric circuits to reducing Aharonov-Bohm-based quantum networks into equivalent models. With examples, we show from first principles how the requirements are related to the electron band structure's Fermi level and the lattice spacing of the network. Quantum networks of varying degrees of coupling strength from four basic classifications of single and double entangled loops sharing symmetry and highly correlated band structures are used to demonstrate the concept. We show the limitations of how the principle may be applied. Several classes of examples are given and their equivalent forms are shown.
Electromagnetic potential vectors and the Lagrangian of a charged particle
NASA Technical Reports Server (NTRS)
Shebalin, John V.
1992-01-01
Maxwell's equations can be shown to imply the existence of two independent three-dimensional potential vectors. A comparison between the potential vectors and the electric and magnetic field vectors, using a spatial Fourier transformation, reveals six independent potential components but only four independent electromagnetic field components for each mode. Although the electromagnetic fields determined by Maxwell's equations give a complete description of all possible classical electromagnetic phenomena, potential vectors contains more information and allow for a description of such quantum mechanical phenomena as the Aharonov-Bohm effect. A new result is that a charged particle Lagrangian written in terms of potential vectors automatically contains a 'spontaneous symmetry breaking' potential.
An AB effect without closing a loop
A. Retzker; Y. Aharonov; A. Botero; S. Nussinov; B. Reznik
2006-04-02
We discuss the consequences of the Aharonov-Bohm effect in setups involving several charged particles, wherein none of the charged particles encloses a closed loop around the magnetic flux. We show that in such setups, the AB phase is encoded either in the relative phase of a bi-partite or multi-partite entangled photons states, or alternatively, gives rise to an overall AB phase that can be measured relative to another reference system. These setups involve processes of annihilation or creation of electron/hole pairs. We discuss the relevance of such effects in "vacuum Birefringence" in QED, and comment on their connection to other known effects.
On the Landau system in noncommutative phase-space
NASA Astrophysics Data System (ADS)
Gangopadhyay, Sunandan; Saha, Anirban; Halder, Aslam
2015-12-01
We consider the Landau system in a canonically noncommutative phase-space. A set of generalized transformations containing scaling parameters is derived which maps the NC problem to an equivalent commutative problem. The energy spectrum admits NC corrections which are computed using the explicit NC variables as well as the commutative-equivalent variables. Their exact matching solidifies the evidence of the equivalence of the two approaches. We also obtain the magnetic length and level degeneracy, which admit NC corrections. We further study the Aharonov-Bohm effect where the phase-shift is found to alter due to noncommutativity and also depends on the scaling parameters.
Berry's phase in rotating systems
NASA Astrophysics Data System (ADS)
Cui, Shi-Min; Xu, Hong-Hua
1991-09-01
It is shown that, in addition to the Aharonov-Bohm-like phase studied previously [M. V. Berry, Proc. R. Soc. London Ser. A 392, 45 (1984); Y. Aharakov and J. Anandan, Phys. Rev. Lett. 58, 1593 (1987); C. H. Tsai and D. Neilson, Phys. Rev. A 37, 619 (1988)], Berry's topological phase also appears for purely mechanical reasons in systems rotating at slowly-time-varying angular velocity about a fixed center. A possible experiment to probe this manifestation of Berry's phase is discussed.
Aharonov-casher effect in Bi2Se3 square-ring interferometers.
Qu, Fanming; Yang, Fan; Chen, Jun; Shen, Jie; Ding, Yue; Lu, Jiangbo; Song, Yuanjun; Yang, Huaixin; Liu, Guangtong; Fan, Jie; Li, Yongqing; Ji, Zhongqing; Yang, Changli; Lu, Li
2011-07-01
Electrical control of spin dynamics in Bi(2)Se(3) was investigated in ring-type interferometers. Aharonov-Bohm and Altshuler-Aronov-Spivak resistance oscillations against a magnetic field, and Aharonov-Casher resistance oscillations against the gate voltage were observed in the presence of a Berry phase of ?. A very large tunability of spin precession angle by the gate voltage has been obtained, indicating that Bi(2)Se(3)-related materials with strong spin-orbit coupling are promising candidates for constructing novel spintronic devices. PMID:21797562
NASA Astrophysics Data System (ADS)
Shech, Elay
2015-09-01
This paper looks at the nature of idealizations and representational structures appealed to in the context of the fractional quantum Hall effect, specifically, with respect to the emergence of anyons and fractional statistics. Drawing on an analogy with the Aharonov-Bohm effect, it is suggested that the standard approach to the effects—(what we may call) the topological approach to fractional statistics—relies essentially on problematic idealizations that need to be revised in order for the theory to be explanatory. An alternative geometric approach is outlined and endorsed. Roles for idealizations in science, as well as consequences for the debate revolving around so-called essential idealizations, are discussed.
Cold Atoms in Non-Abelian Gauge Potentials: From the Hofstadter Moth to Lattice Gauge Theory
Osterloh, K.; Baig, M.; Santos, L.; Zoller, P.; Lewenstein, M.
2005-07-01
We demonstrate how to create artificial external non-Abelian gauge potentials acting on cold atoms in optical lattices. The method employs atoms with k internal states, and laser assisted state sensitive tunneling, described by unitary kxk matrices. The single-particle dynamics in the case of intense U(2) vector potentials lead to a generalized Hofstadter butterfly spectrum which shows a complex mothlike structure. We discuss the possibility to realize non-Abelian interferometry (Aharonov-Bohm effect) and to study many-body dynamics of ultracold matter in external lattice gauge fields.
Surface state dominated transport in topological insulator Bi{sub 2}Te{sub 3} nanowires
Hamdou, Bacel Gooth, Johannes; Dorn, August; Nielsch, Kornelius; Pippel, Eckhard
2013-11-04
We report on low temperature magnetoresistance measurements on single-crystalline Bi{sub 2}Te{sub 3} nanowires synthesized via catalytic growth and post-annealing in a Te-rich atmosphere. The observation of Aharonov-Bohm oscillations indicates the presence of topological surface states. Analyses of Subnikov-de Haas oscillations in perpendicular magnetoresistance yield extremely low two-dimensional carrier concentrations and effective electron masses, and very high carrier mobilities. All our findings are in excellent agreement with theoretical predictions of massless Dirac fermions at the surfaces of topological insulators.
From gauge transformations to topology computation in quantum lattice gas automata
David A. Meyer
2001-05-17
The evolution of a quantum lattice gas automaton (LGA) for a single charged particle is invariant under multiplication of the wave function by a global phase. Requiring invariance under the corresponding local gauge transformations determines the rule for minimal coupling to an arbitrary external electromagnetic field. We develop the Aharonov-Bohm effect in the resulting model into a constant time algorithm to distinguish a one dimensional periodic lattice from one with boundaries; any classical deterministic LGA algorithm distinguishing these two spatial topologies would have expected running time on the order of the cardinality of the lattice.
Topological properties of linear circuit lattices
Victor V. Albert; Leonid I. Glazman; Liang Jiang
2015-03-10
Motivated by the topologically insulating (TI) circuit of capacitors and inductors proposed and tested in arXiv:1309.0878, we present a related circuit with less elements per site. The normal mode frequency matrix of our circuit is unitarily equivalent to the hopping matrix of a quantum spin Hall insulator (QSHI) and we identify perturbations that do not backscatter the circuit's edge modes. The idea behind these models is generalized, providing a platform to simulate tunable and locally accessible lattices with arbitrary complex spin-dependent hopping of any range. A simulation of a non-Abelian Aharonov-Bohm effect using such linear circuit designs is discussed.
Geometric-phase atom optics and interferometry
NASA Astrophysics Data System (ADS)
Zygelman, B.
2015-10-01
We illustrate how geometric gauge forces and topological phase effects emerge in atomic and molecular systems without employing assumptions that rely on adiabaticity. We show how geometric magnetism may be harnessed to engineer novel quantum devices including a velocity sieve, a component in mass spectrometers, for neutral atoms. We introduce and outline a possible experimental setup that demonstrates topological interferometry for neutral spin-1/2 systems. For that two-level system, we study the transition from Abelian to non-Abelian behavior and explore its relation to the molecular Aharonov-Bohm effect.
NASA Astrophysics Data System (ADS)
Zhukovsky, V. Ch.; Stepanov, E. A.
2012-12-01
Generation of mass on two-dimensional brane in three-dimensional model with four-fermion interaction including external gauge field A3 is considered. In the framework of this model the generated mass proves to be lighter than Kaluza-Klein modes, thus indicating to a possibility of solving the mass hierarchy problem. Dependence of the effective potential and the coupling constant on characteristics of the model such as compactification radius, gauge field and phase shift parameter was also obtained. It is demonstrated that the generated mass, besides the dynamic part, includes also a kinematic (topological) contribution, i.e. the Aharonov-Bohm phase.
Nonlocal Pancharatnam phase in two-photon interferometry
Mehta, Poonam; Samuel, Joseph; Sinha, Supurna
2010-09-15
We propose a polarized intensity interferometry experiment, which measures the nonlocal Pancharatnam phase acquired by a pair of Hanbury-Brown-Twiss photons. The setup involves two polarized thermal sources illuminating two polarized detectors. Varying the relative polarization angle of the detectors introduces a two-photon geometric phase. Local measurements at either detector do not reveal the effects of the phase, which is an optical analog of the multiparticle Aharonov-Bohm effect. The geometric phase sheds light on the three-slit experiment and suggests ways of tuning entanglement.
EMS adaptation for climate change
NASA Astrophysics Data System (ADS)
Pan, C.; Chang, Y.; Wen, J.; Tsai, M.
2010-12-01
The purpose of this study was to find an appropriate scenario of pre-hospital transportation of an emergency medical service (EMS) system for burdensome casualties resulting from extreme climate events. A case of natural catastrophic events in Taiwan, 88 wind-caused disasters, was reviewed and analyzed. A sequential-conveyance method was designed to shorten the casualty transportation time and to promote the efficiency of ambulance services. A proposed mobile emergency medical center was first constructed in a safe area, but nearby the disaster area. The Center consists of professional medical personnel who process the triage of incoming patients and take care of casualties with minor injuries. Ambulances in the Center were ready to sequentially convey the casualties with severer conditions to an assigned hospital that is distant from the disaster area for further treatment. The study suggests that if we could construct a spacious and well-equipped mobile emergency medical center, only a small portion of casualties would need to be transferred to distant hospitals. This would reduce the over-crowding problem in hospital ERs. First-line ambulances only reciprocated between the mobile emergency medical center and the disaster area, saving time and shortening the working distances. Second-line ambulances were highly regulated between the mobile emergency medical center and requested hospitals. The ambulance service of the sequential-conveyance method was found to be more efficient than the conventional method and was concluded to be more profitable and reasonable on paper in adapting to climate change. Therefore, additional practical work should be launched to collect more precise quantitative data.
Al-Shaqsi, Sultan Zayed Khalifah
2009-07-01
The Emergency Medical Services (EMS) in Oman is a relatively new project in the country. It has been developed based on the Anglo-American system of EMS. Currently, it is run by trained Omani Advanced Emergency Medical Technicians (AEMT) under the auspices of the Royal Oman Police (ROP) Ambulance Division. The system covers most of the country and responds to medical and trauma emergencies. It is state-funded and free of charge for all people in Oman. There are plans to incorporate aero-medical services into the system, to support the land ambulance service, and there are also plans to expand its coverage to the whole country by 2012. The EMS in Oman has hard challenges ahead but there are also promising plans in place to improve the system. PMID:19467757
Dirio Econmico -Universidades Como ser investigador em Portugal
Instituto de Sistemas e Robotica
Diário Económico - Universidades Como é ser investigador em Portugal Autor: N.D. Editora: ST e SF - Universidades Como é ser investigador em Portugal Autor: N.D. Editora: ST e SF Id: 1646658 Data Publicação: 19
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2013 CFR
2013-01-01
... 10 Energy 2 2013-01-01 2013-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part...
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2012 CFR
2012-01-01
... 10 Energy 2 2012-01-01 2012-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2011 CFR
2011-01-01
... 10 Energy 2 2011-01-01 2011-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part...
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2014 CFR
2014-01-01
... 10 Energy 2 2014-01-01 2014-01-01 false E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...
ECE 341: Electromagnetic Fields I EM devices and systems
Connors, Daniel A.
in material media - Electromagnetic induction - Inductance - Magnetic energy Applications: - ElectronicsECE 341: Electromagnetic Fields I EM devices and systems - Can compute and analyze potentials compositions - Can evaluate capacitance, inductance, resistance, and conductance of EM structures - Understands
Risk Communication Within the EM Program
Edelson, M.
2003-02-26
The U.S. Department of Energy Environmental Management program (EM) conducts the most extensive environmental remediation effort in the world. The annual EM budgets have exceeded $6,000,000,000 for approximately ten years and EM has assumed responsibility for the cleanup of the largest DOE reservations (i.e., at Hanford, Washington, Aiken, South Carolina, and Idaho Falls, Idaho) as well as the facilities at Rocky Flats, Colorado and in Ohio. Each of these sites has areas of extensive radioactive and chemical contamination, numerous surplus facilities that require decontamination and removal, while some have special nuclear material that requires secure storage. The EM program has been criticized for being ineffective (1) and has been repeatedly reorganized to address perceived shortcomings. The most recent reorganization was announced in 2001 to become effective at the beginning of the 2003 Federal Fiscal Year (i.e., October 2002). It was preceded by a ''top to bottom'' review (TTBR) of the program (2) that identified several deficiencies that were to be corrected as a result of the reorganization. One prominent outcome of the TTBR was the identification of ''risk reduction'' as an organizing principle to prioritize the activities of the new EM program. The new program also sought to accelerate progress by identifying a set of critical activities at each site that could be accelerated and result in more rapid site closure, with attendant risk, cost, and schedule benefits. This paper investigates how the new emphasis on risk reduction in the EM program has been communicated to EM stakeholders and regulators. It focuses on the Rocky Flats Environmental Technology Site (RFETS) as a case study and finds that there is little evidence for a new emphasis on risk reduction in EM communications with RFETS stakeholders. Discussions between DOE and RFETS stakeholders often refer to ''risk,'' but the word serves as a placeholder for other concepts. Thus ''risk'' communication at RFETS is lively and involves important issues, but often does not inform participants about true ''risk reduction.''
Leica EM AFS2 Automatic Freeze Substitution System
Chapman, Michael S.
Leica EM AFS2 Automatic Freeze Substitution System Leica EM FSP Freeze Substitution Processor #12 working range · "Deep Freeze" allows sample transfer at temperatures below -140 °C · Transfer function "TF steel working platform Leica EM AFS2 Freeze Substitution has never been easier... Freeze Substitution
REGIMENTO DO CURSO DE PSGRADUAO EM COMPUTAO APLICADA
REGIMENTO DO CURSO DE PÓSGRADUAÇÃO EM COMPUTAÇÃO APLICADA Regimento aprovado pelo CPG em 19/02/2003. TÍTULO I DOS OBJETIVOS E FINALIDADES Art 1º O Curso de PósGraduação a nível de Mestrado e Doutorado em Computação Aplicada CAP, doravante referido como Curso, objetiva formar e capacitar pessoal de nível
CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM ENGENHARIA E GERENCIAMENTO DE SISTEMAS ESPACIAIS Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenador da Área de, Doutora, ITA, Brasil, 1990 Roberto Luiz Galski, Doutor, INPE, Brasil, 2006 #12;2 CURSO DE PÓS-GRADUAÇÃO EM
REGIMENTO DO CURSO DE PSGRADUAO EM COMPUTAO APLICADA
REGIMENTO DO CURSO DE PÓSGRADUAÇÃO EM COMPUTAÇÃO APLICADA Regimento aprovado pelo CPG em 04/11/2004. TÍTULO I DOS OBJETIVOS E FINALIDADES Art 1º O Curso de PósGraduação a nível de Mestrado e Doutorado em Computação Aplicada CAP, doravante referido como Curso, objetiva formar e capacitar pessoal de nível
CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM CIÊNCIA E TECNOLOGIA DE MATERIAIS E SENSORES Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenador Acadêmico Vladimir Jesus Trava-Airoldi, Doutor, ITA, Brasil, 1986 #12;2 CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E
REGIMENTO DO CURSO DE PSGRADUAO EM COMPUTAO APLICADA
REGIMENTO DO CURSO DE PÓSGRADUAÇÃO EM COMPUTAÇÃO APLICADA Regimento aprovado pelo CPG em 17/11/2005. TÍTULO I DOS OBJETIVOS E FINALIDADES Art 1º O Curso de pósgraduação em Computação Aplicada, doravante referido como Curso, mantém programas de Mestrado e Doutorado com objetivo de
Erdvini? Žem?s Plutos Judesi? Apibendrint?j? Charakteristik? Nustatymas Pagal GPS Matavim? Duomenis
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Aksamitauskas, Vladislovas ?eslovas; Stanionis, Arminas; Levinskait?, Daiva
2009-01-01
Erdvini? Žem?s plutos judesi? apibendrintosios charakteristikos pagal GPS matavim? duomenis Ignalinos atomin?s elektrin?s rajone ?vertintos taikant tenzorin?s analiz?s metodik?. Svarbiausi?j? tektonini? ?tempi? poky?iai nustatyti trigonometriniu metodu. Apskai?iuoti nauji erdvini? Žem?s plutos judesi? apibendrint?j? charakteristik? duomenys - poslinkiai koordina?i? aši? kryptimis; blokin?s strukt?ros pos?kis; santykin?s linijin?s bei šlyties deformacijos; normalini?, tangentini? bei svarbiausi?j? tektonini? ?tempi? poky?iai. Apibendrintosios santykin?s deformacijos kinta nuo 0,012 · 10-6, iki -0,760 · 10-6, ?tempiai svyruoja nuo -0,003 MPa iki -0,059 MPa. Nustatyta, kad santykini? deformacij? ir ?tempi? poky?i? reikšm?s visame nagrin?jamame Ignalinos atomin?s elektrin?s rajone yra neigiamo ženklo, t. y. teritorija yra veikiama bendrojo tektoninio spaudimo.
UNIVERSIDADE DE BRASLIA PROGRAMA DE PS-GRADUAO EM CINCIAS E TECNOLOGIAS EM SADE
Maier, Rudolf Richard
deglutição. Dor orofacial. 1 1 Biologia Molecular aplicada ao estudo de fungos patogênicos humanos 1 0 deglutição. Dor orofacial. 1 1 Biologia Molecular aplicada PROCESSOS BIOLÓGICOS EM SAÚDE 1.1. Mecanismos Moleculares e Funcionais da Saúde Humana Mecanismos
TIME DOMAIN EM PROFILING SHALLOW CONDUCTING TARGET
Merriam, James
. Introduction The target is constructed from three separate 24 gage galvanized steel sheets pop-riveted toTIME DOMAIN EM PROFILING OVER A SHALLOW CONDUCTING TARGET J.B. Merriam University of Saskatchewan-47 profile over a known target at one to three m depth is described here. The response of the highly
Transportes em Revista.com Pas: Portugal
Instituto de Sistemas e Robotica
menos de 25 km por dia por: Carlos Moura Tags: Automóveis Galp Energia Mobilidade el étrica realizado em Portugal que resultou de uma parceria entre a Toyota Caetano Portugal, a Galp Energia o s f o r a m e n t r e g u e s a o s colaboradores da Galp Energia, residentes nos concelhos de
Electro Magnetic (EM) Uses Radio Waves
Naik, Naren
#12;RADAR Electro Magnetic (EM) SENSOR Uses Radio Waves Used for Detection of Objects Finding as a Motivation for Learning and Understanding DSP Radar concepts can be used in ROBOT Radar, SONAR ,Ultrasonic ranging etc #12;INTRODUCTION TO RADAR RADAR = Radio Detection and Ranging · Detects targets by receipt
REGIMENTO DO CURSO DE PSGRADUAO EM COMPUTAO APLICADA Regimento aprovado pelo CPG em 07/11/2006
REGIMENTO DO CURSO DE PÓSGRADUAÇÃO EM COMPUTAÇÃO APLICADA Regimento aprovado pelo CPG em 07/11/2006 TÍTULO I DOS OBJETIVOS E FINALIDADES Art 1º O Curso de pósgraduação em Computação Aplicada, doravante referido como Curso, mantém programas de Mestrado e Doutorado com objetivo de formar e capacitar pessoal
Instituto de Sistemas e Robotica
Página Inicial Empresas Start-ups portuguesas mostram-se hoje a investidores suecos em Lisboa | Start-ups portuguesas mostram-se hoje a investidores suecos em Lisboa Comprei uns óculos, fui à organizado pela AICEP e universidades Start-ups portuguesas mostram-se hoje a investidores suecos em Lisboa
The association between EMS workplace safety culture and safety outcomes
Weaver, Matthew D.; Wang, Henry E.; Fairbanks, Rollin J.; Patterson, Daniel
2012-01-01
Objective Prior studies have highlighted wide variation in EMS workplace safety culture across agencies. We sought to determine the association between EMS workplace safety culture scores and patient or provider safety outcomes. Methods We administered a cross-sectional survey to EMS workers affiliated with a convenience sample of agencies. We recruited these agencies from a national EMS management organization. We used the EMS Safety Attitudes Questionnaire (EMS-SAQ) to measure workplace safety culture and the EMS Safety Inventory (EMS-SI), a tool developed to capture self-reported safety outcomes from EMS workers. The EMS-SAQ provides reliable and valid measures of six domains: safety climate, teamwork climate, perceptions of management, perceptions of working conditions, stress recognition, and job satisfaction. A panel of medical directors, paramedics, and occupational epidemiologists developed the EMS-SI to measure self-reported injury, medical errors and adverse events, and safety-compromising behaviors. We used hierarchical linear models to evaluate the association between EMS-SAQ scores and EMS-SI safety outcome measures. Results Sixteen percent of all respondents reported experiencing an injury in the past 3 months, four of every 10 respondents reported an error or adverse event (AE), and 90% reported safety-compromising behaviors. Respondents reporting injury scored lower on 5 of the 6 domains of safety culture. Respondents reporting an error or AE scored lower for 4 of the 6 domains, while respondents reporting safety-compromising behavior had lower safety culture scores for 5 of 6 domains. Conclusions Individual EMS worker perceptions of workplace safety culture are associated with composite measures of patient and provider safety outcomes. This study is preliminary evidence of the association between safety culture and patient or provider safety outcomes. PMID:21950463
Self-accelerating Dirac particles and prolonging the lifetime of relativistic fermions
NASA Astrophysics Data System (ADS)
Kaminer, Ido; Nemirovsky, Jonathan; Rechtsman, Mikael; Bekenstein, Rivka; Segev, Mordechai
2015-03-01
The Aharonov-Bohm effect predicts that two parts of the electron wavefunction can accumulate a phase difference even when they are confined to a region in space with zero electromagnetic field. Here we show that engineering the wavefunction of electrons, as accelerating shape-invariant solutions of the potential-free Dirac equation, fundamentally acts as a force and the electrons accumulate an Aharonov-Bohm-type phase--which is equivalent to a change in the proper time and is related to the twin-paradox gedanken experiment. This implies that fundamental relativistic effects such as length contraction and time dilation can be engineered by properly tailoring the initial conditions. As an example, we suggest the possibility of extending the lifetime of decaying particles, such as an unstable hydrogen isotope, or altering other decay processes. We find these shape-preserving Dirac wavefunctions to be part of a family of accelerating quantum particles, which includes massive/massless fermions/bosons of any spin.
TandEM: Titan and Enceladus mission
Coustenis, A.; Atreya, S.K.; Balint, T.; Brown, R.H.; Dougherty, M.K.; Ferri, F.; Fulchignoni, M.; Gautier, D.; Gowen, R.A.; Griffith, C.A.; Gurvits, L.I.; Jaumann, R.; Langevin, Y.; Leese, M.R.; Lunine, J.I.; McKay, C.P.; Moussas, X.; Muller-Wodarg, I.; Neubauer, F.; Owen, T.C.; Raulin, F.; Sittler, E.C.; Sohl, F.; Sotin, C.; Tobie, G.; Tokano, T.; Turtle, E.P.; Wahlund, J.-E.; Waite, J.H.; Baines, K.H.; Blamont, J.; Coates, A.J.; Dandouras, I.; Krimigis, T.; Lellouch, E.; Lorenz, R.D.; Morse, A.; Porco, C.C.; Hirtzig, M.; Saur, J.; Spilker, T.; Zarnecki, J.C.; Choi, E.; Achilleos, N.; Amils, R.; Annan, P.; Atkinson, D.H.; Benilan, Y.; Bertucci, C.; Bezard, B.; Bjoraker, G.L.; Blanc, M.; Boireau, L.; Bouman, J.; Cabane, M.; Capria, M.T.; Chassefiere, E.; Coll, P.; Combes, M.; Cooper, J.F.; Coradini, A.; Crary, F.; Cravens, T.; Daglis, I.A.; de Angelis, E.; De Bergh, C.; de Pater, I.; Dunford, C.; Durry, G.; Dutuit, O.; Fairbrother, D.; Flasar, F.M.; Fortes, A.D.; Frampton, R.; Fujimoto, M.; Galand, M.; Grasset, O.; Grott, M.; Haltigin, T.; Herique, A.; Hersant, F.; Hussmann, H.; Ip, W.; Johnson, R.; Kallio, E.; Kempf, S.; Knapmeyer, M.; Kofman, W.; Koop, R.; Kostiuk, T.; Krupp, N.; Kuppers, M.; Lammer, H.; Lara, L.-M.; Lavvas, P.; Le, Mouelic S.; Lebonnois, S.; Ledvina, S.; Li, J.; Livengood, T.A.; Lopes, R.M.; Lopez-Moreno, J. -J.; Luz, D.; Mahaffy, P.R.; Mall, U.; Martinez-Frias, J.; Marty, B.; McCord, T.; Salvan, C.M.; Milillo, A.; Mitchell, D.G.; Modolo, R.; Mousis, O.; Nakamura, M.; Neish, C.D.; Nixon, C.A.; Mvondo, D.N.; Orton, G.; Paetzold, M.; Pitman, J.; Pogrebenko, S.; Pollard, W.; Prieto-Ballesteros, O.; Rannou, P.; Reh, K.; Richter, L.; Robb, F.T.; Rodrigo, R.; Rodriguez, S.; Romani, P.; Bermejo, M.R.; Sarris, E.T.; Schenk, P.; Schmitt, B.; Schmitz, N.; Schulze-Makuch, D.; Schwingenschuh, K.; Selig, A.; Sicardy, B.; Soderblom, L.; Spilker, L.J.; Stam, D.; Steele, A.; Stephan, K.; Strobel, D.F.; Szego, K.; Szopa
2009-01-01
TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (Montgolfi??re) and possibly several landing probes to be delivered through the atmosphere. ?? Springer Science + Business Media B.V. 2008.
2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) ...
2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) BARRACKS WITH RADAR ATTACHED. - Nike Hercules Missile Battery Summit Site, Battery Control Administration & Barracks Building, Anchorage, Anchorage, AK
Svarbiausi?j? Erdvini? Žem?s Plutos ?tempi? Poky?i? Nustatymas Pagal GPS matavim? Rezultatus
NASA Astrophysics Data System (ADS)
Stanionis, Arminas
2008-06-01
Svarbiausi?j? erdvini? Žem?s plutos ?tempi? poky?iai pagal GPS matavim? Ignalinos atomin?s elektrin?s rajone rezultatus nustatyti tenzorin?s analiz?s b?du. Taikant atvirkštin? Huko d?sn? apskai?iuoti nauji dabartini? Žem?s plutos judesi? charakteristikos duomenys - svarbiausi?j? erdvini? ?tempi? poky?iai. Jie siekia nuo -0,082 MPa iki 0,112 MPa. Nustatyta, kad svarbiausi?j? ?tempi? poky?i? savybi? kaita yra d?sninga, t. y. susijusi su kristalinio pamato tektonini? l?ži? išsid?stymu.
AVALIAÇÃO DA PRESENÇA DE ENDOSSIMBIONTES Cardinium em DIFERENTES ESPÉCIES DE ARTRÓPODES.
Technology Transfer Automated Retrieval System (TEKTRAN)
A presença de endossimbiontes do gênero Cardinium em alguns grupos de artrópodes foi recentemente relatada e relacionada com diversas alterações reprodutivas em seus hospedeiros, tais como feminilização de ácaros, partenogênese em parasitóides, incompatibilidade citoplasmática e aumento da fecundida...
Marine EM Reference Database http://marineemlab.ucsd.edu/~kkey/MarineEM
Key, Kerry
to document the peer-reviewed published papers that cover any aspect of marine electromagnetic induction. Techniques and instrumentation for study of natu- ral electromagnetic induction at sea. Physics Of The Earth. I started this database as part of a review paper that was presented at the 20th EM Induction
Communication - An Effective Tool for Implementing ISO 14001/EMS
Rachel Damewood; Bowen Huntsman
2004-04-01
The Idaho National Engineering and Environmental Laboratory (INEEL) received ISO 14001/EMS certification in June 2002. Communication played an effective role in implementing ISO 14001/EMS at the INEEL. This paper describes communication strategies used during the implementation and certification processes. The INEEL achieved Integrated Safety Management System (ISMS) and Voluntary Protection Program (VPP) Star status in 2001. ISMS implemented a formal process to plan and execute work. VPP facilitated worker involvement by establishing geographic units at various facilities with employee points of contact and management champions. The INEEL Environmental Management System (EMS) was developed to integrate the environmental functional area into its ISMS and VPP. Since the core functions of ISMS, VPP, and EMS are interchangeable, they were easy to integrate. Communication is essential to successfully implement an EMS. (According to ISO 14001 requirements, communication interacts with 12 other elements of the requirements.) We developed communication strategies that integrated ISMS, VPP, and EMS. For example, the ISMS, VPP, and EMS Web sites communicated messages to the work force, such as “VPP emphasizes the people side of doing business, ISMS emphasizes the system side of doing business, and EMS emphasizes the systems to protect the environment; but they all define work, identify and analyze hazards, and mitigate the hazards.” As a result of this integration, the work force supported and implemented the EMS. In addition, the INEEL established a cross-functional communication team to assist with implementing the EMS. The team included members from the Training and Communication organizations, VPP office, Pollution Prevention, Employee and Media Relations, a union representative, facility environmental support, and EMS staff. This crossfunctional team used various communication strategies to promote our EMS to all organization levels and successfully implemented EMS activities through VPP geographic units. In summary, the ISMS and VPP process at the INEEL provided the basic framework of management support and worker involvement to implement our EMS. A cross-functional communication team was established to facilitate the implementation with great success. Communication has been an effective tool for implementing an ISO 14001/EMS at the INEEL.
EM threat analysis for wireless systems.
Burkholder, R. J. (Ohio State University Electroscience Laboratory); Mariano, Robert J.; Schniter, P. (Ohio State University Electroscience Laboratory); Gupta, I. J. (Ohio State University Electroscience Laboratory)
2006-06-01
Modern digital radio systems are complex and must be carefully designed, especially when expected to operate in harsh propagation environments. The ability to accurately predict the effects of propagation on wireless radio performance could lead to more efficient radio designs as well as the ability to perform vulnerability analyses before and after system deployment. In this report, the authors--experts in electromagnetic (EM) modeling and wireless communication theory--describe the construction of a simulation environment that is capable of quantifying the effects of wireless propagation on the performance of digital communication.
Aquisição de Estreptococos Mutans e Desenvolvimento de Cárie Dental em Primogênitos
NOCE, Erica; RUBIRA, Cassia Maria Fischer; da Silva ROSA, Odila Pereira; da SILVA, Salete Moura Bonifácio; BRETZ, Walter Antonio
2011-01-01
Objetivo Avaliar o momento de aquisição de estreptococos mutans (EM), desenvolvimento de cárie dental e as variáveis a eles associadas no decorrer de 23 meses, em primogênitos de famílias de baixo nível socioeconômico, desde os sete meses de idade. Método A amostra foi selecionada com base em mães densamente colonizadas por EM, incluindo todos os membros de 14 famílias que conviviam na mesma casa. Foram envolvidos no estudo 14 mães, pais e primogênitos e 8 parentes, na maioria avós. Exames clínicos e radiográficos iniciais determinaram os índices de cárie e condição periodontal dos adultos. Contagens de EM foram feitas em todos os adultos nas duas primeiras visitas. Nas crianças foram avaliados os níveis de EM, o número de dentes e de cáries, em quatro visitas. Resultados A prevalência de EM nos adultos foi alta, estando ausente em apenas um dos pais. EM foram detectados em 1, 2, 3 e 10 crianças, respectivamente nas visitas #1, 2, 3 e 4. A cárie dental foi detectada em apenas três crianças na última visita (aos 30 meses de idade), as quais apresentaram escores de EM significantemente maiores que as crianças sem cárie, na mesma visita. Conclusão Exclusivamente a condição social de baixa renda e mães densamente colonizadas por EM não são sinônimo de colonização precoce e alta atividade de cárie em crianças cuidadas em casa. O desenvolvimento de cárie está significantemente associado a escores elevados de EM nas crianças. PMID:22022218
7 CFR 1945.20 - Making EM loans available.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Secretary in making a decision on the requested natural disaster determination. (4) The Secretary will... 7 Agriculture 13 2012-01-01 2012-01-01 false Making EM loans available. 1945.20 Section 1945.20...) PROGRAM REGULATIONS (CONTINUED) EMERGENCY Disaster Assistance-General § 1945.20 Making EM loans...
ARTIGO INTERNET Jogos Srios em debate no IST
Instituto de Sistemas e Robotica
ARTIGO INTERNET «Jogos Sérios» em debate no IST in http://sol.sapo.pt/ Data: 2011-9-15 Link: http://sol.sapo.pt/inicio/Tecn ... «Jogos Sérios» em debate no IST O Instituto Superior Técnico (IST) vai ser o palco da II Conferência Internacional sobre aplicações e desenvolvimento de «Jogos Sérios» A conferência terá lugar nos dias 19 e 20 de
10 CFR Appendixes E-M to Part 52 - [Reserved
Code of Federal Regulations, 2014 CFR
2014-01-01
10 Energy 2 2014-01-01 2014-01-01 false [Reserved] E Appendixes E-M to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Appendixes E-M to Part 52...
7 CFR 1945.20 - Making EM loans available.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Secretary in making a decision on the requested natural disaster determination. (4) The Secretary will... 7 Agriculture 13 2010-01-01 2009-01-01 true Making EM loans available. 1945.20 Section 1945.20...) PROGRAM REGULATIONS (CONTINUED) EMERGENCY Disaster Assistance-General § 1945.20 Making EM loans...
CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM MECÂNICA ESPACIAL E CONTROLE Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenador Acadêmico da Área de / USP, 2000. Waldemar de Castro Leite Filho, Doutor, UFRJ/COPPE, 1991. #12;2 CURSO DE ENGENHARIA E
REGIMENTO DO CURSO DE PSGRADUAO EM COMPUTAO TTULOIDOSOBJETIVOSEFINALIDADES
1 REGIMENTO DO CURSO DE PÓSGRADUAÇÃO EM COMPUTAÇÃO APLICADA TÍTULOIDOSOBJETIVOSEFINALIDADES Art. 1o O Curso de pósgraduação em Computação Aplicada, doravante referido como Curso e ciências correlatas. TÍTULOIIDAORGANIZAÇÃOGERAL Art. 2o O Curso regerseá pelo Regimento dos
CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM COMBUSTÃO E PROPULSÃO Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenador da Área de Concentração David dos Mendonça do IAE/CTA, Univ. Pennsylvania, USA, 1997 #12;CURSO DE ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE
REGIMENTO DO CURSO DE PS-GRADUAO EM METEOROLOGIA
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM METEOROLOGIA TÍTULO I DOS OBJETIVOS DO CURSO Art. 1º - O Curso de Pós-Graduação em Meteorologia do INPE tem como objetivo a formação de recursos humanos, nos níveis de Mestrado e de Doutorado, visando o progresso da Meteorologia no País. Parágrafo Único - O Curso
EVALUATING EMS VALUE -THE CASE OF A SMALL ACCOUNTANCY FIRM
Antunes, Pedro
of these systems. EMS lay down one sub area of research crossing Computer Supported Cooperative Work (CSCW and distribution, and progress review. The literature reports several EMS aiming at supporting the above tasks 2 we review the literature on different approaches to evaluating information systems
CURSO DE PS-GRADUAO EM SENSORIAMENTO REMOTO Coordenador Acadmico
Hidrológicos SER-457-3 População, Espaço e Meio Ambiente SER-730-0 Pesquisa de Mestrado em SER SER-780-340-3 Sensoriamento Remoto dos Oceanos SER-324-3 Estudos do Meio Físico em Sistemas Agrícolas SER-338
US Army Corps of Engineers
. The types of concrete hydraulic structures addressed in this manual include dams, U- and W-frame locksEM 1110-2-6053 1 May 2007 US Army Corps Of Engineers Earthquake Design and Evaluation of Concrete OF CONCRETE HYDRAULIC STRUCTURES EM 111 0-2-6053 1 August 2007 1. Purpose. This manual provides guidance
Yeast EM with LR White See EM method for yeast cells. Notes below apply to the steps indicated.
Aris, John P.
109 Yeast EM with LR White See EM method for yeast cells. Notes below apply to the steps indicated% formaldehyde + 0.1% glutaraldehyde 5. Fix for only 30 minutes at room temperature with gentle rotation. [Optional: Quench fixative. Wash sample 2X with PC buffer at room temperature. Incubate for 15 minutes
Neirotti, Juan Pablo
: Dip/MSc Engineering Management. MSc Industrial Enterprise Management. Dip/MSc Supply Chain ManagementApproved Module Information for EM4001, 2014/5 Module Title/Name: Strategic Finance Module Code: EM: 10 Module Management Information Module Leader Name Jack Carnell Email Address j.carnell1@aston
CATLOGO DO CURSO DE PS-GRADUAO EM ASTROFSICA CATLOGO DO CURSO DE PS-GRADUAO EM ASTROFSICA
CATÁLOGO DO CURSO DE PÓS-GRADUAÇÃO EM ASTROFÍSICA CATÁLOGO DO CURSO DE PÓS-GRADUAÇÃO EM ASTROFÍSICA Coordenador Acadêmico André de Castro Milone Conselho de curso André de Castro Milone Cláudia Vilega Rodrigues Joaquim Eduardo Rezende Costa Odylio Denys de Aguiar, Coordenador de Curso Substituto Elvis Camilo
NASA Astrophysics Data System (ADS)
Van Dyk, Schuyler D.; Chornock, R.; Filippenko, A. V.; Foley, R. J.; Lewin, W. H. G.; Li, W.; Panagia, N.; Pooley, D.; Stockdale, C. J.; Weiler, K. W.
2009-12-01
The supernova (SN) 2001em in UGC 11794 was classified early as Type Ib/c, i.e., as one arising from a hydrogen-stripped star. As part of a radio survey with the Very Large Array of SNe Ib/c at late times (Stockdale et al. 2003, BAAS, 35, 1346), SN 2001em was detected as a highly luminous radio source ˜2 years after explosion. The SN was also subsequently discovered with Chandra to be a very luminous X-ray source. The properties of both the radio and X-ray emission are more characteristic of the Type II-narrow (IIn) SNe, where the SN shock is interacting with dense, massive circumstellar matter, resulting in bright radio synchrotron emission and thermal bremsstrahlung from the interaction region. In fact, SN 2001em has shown to have spectroscopically transformed to a SN IIn. The premise that this might indicate an off-axis gamma-ray burst has been presented (Granot & Ramirez-Ruiz 2004, ApJ, 609, L9) and later, rather convincingly, refuted (e.g., Schinzel et al. 2009, ApJ, 691, 1380). Chugai & Chevalier (2006, ApJ, 641, 1051) have interpreted the spectral transformation and radio/X-ray emission as the SN shock overtaking the detached hydrogen envelope of the progenitor star, which was shed in a superwind episode many years prior to explosion. Chevalier (2007, RMxAC, 30, 41) has further pointed to the required mass-loss rate in the event being equivalent to what would occur in the eruption of a luminous blue variable (LBV). The optical (ground-based and HST) and radio/X-ray data, together with mid-infrared Spitzer observations, tend to support this scenario of a very massive star that experienced a powerful LBV outburst prior to explosion. Such an event may not be unique, with possible parallels in the cases of SNe 2005bf and 2006jc, and may provide valuable new information about massive stellar evolution.
Queda dos homicídios em São Paulo, Brasil: uma análise descritiva
Peres, Maria Fernanda Tourinho; Vicentin, Diego; Nery, Marcelo Batista; de Lima, Renato Sérgio; de Souza, Edinilsa Ramos; Cerda, Magdalena; Cardia, Nancy; Adorno, e Sérgio
2012-01-01
Objetivo Descrever a evolução da mortalidade por homicídios no Município de São Paulo segundo tipo de arma, sexo, raça ou cor, idade e áreas de exclusão/inclusão social entre 1996 e 2008. Métodos Estudo ecológico de série temporal. Os dados sobre óbitos ocorridos no Município foram coletados da base de dados do Programa de Aprimoramento das Informações sobre Mortalidade, seguindo a Classificação Internacional de Doenças, Décima Revisão (CID-10). Foram calculadas as taxas de mortalidade por homicídio (TMH) para a população total, por sexo, raça ou cor, faixa etária, tipo de arma e área de exclusão/inclusão social. As TMH foram padronizadas por idade pelo método direto. Foram calculados os percentuais de variação no período estudado. Para as áreas de exclusão/inclusão social foram calculados os riscos relativos de morte por homicídio. Resultados As TMH apresentaram queda de 73,7% entre 2001 e 2008. Foi observada redução da TMH em todos os grupos analisados, mais pronunciada em homens (?74,5%), jovens de 15 a 24 anos (?78,0%) e moradores de áreas de exclusão social extrema (?79,3%). A redução ocorreu, sobretudo, nos homicídios cometidos com armas de fogo (?74,1%). O risco relativo de morte por homicídio nas áreas de exclusão extrema (tendo como referência áreas com algum grau de exclusão social) foi de 2,77 em 1996, 3,9 em 2001 e 2,13 em 2008. Nas áreas de alta exclusão social, o risco relativo foi de 2,07 em 1996 e 1,96 em 2008. Conclusões Para compreender a redução dos homicídios no Município, é importante considerar macrodeterminantes que atingem todo o Município e todos os subgrupos populacionais e microdeterminantes que atuam localmente, influenciando de forma diferenciada os homicídios com armas de fogo e os homicídios na população jovem, no sexo masculino e em residentes em áreas de alta exclusão social. PMID:21390415
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Puzien?, R?ta
2009-01-01
Geodeziniais metodais nustatytos vertikali?j? Žem?s plutos judesi? reikšm?s - tektonini? judesi? ir nuos?din?s dangos sluoksni? deformacij? reikšmi? suma. Iš stebim? Žem?s paviršiaus judesi? tiesiogiai beveik ne?manoma spr?sti, kurios reikšm?s tektonin?s, kurios netektonin?s kilm?s judesi?. Tam tikslui matematin?s statistin?s analiz?s metodais atliekami tyrimai. Kadangi Žem?s sandara nevienalyt?, tam tikros informacijos apie tiriam? proces? gali teikti kiekvienas geologinis rodiklis. Siekiant ištirti rodikli? tarpusavio priklausomybes, rodikli? informatyvum?, taikoma kompleksin? koreliacin? analiz? bei Hellwingo metodas.
Pirmasis lietuvi\\vskas Suvalkijos žem?lapis
NASA Astrophysics Data System (ADS)
Girkus, Romualdas; Lukoševi?ius, Viktoras
2009-01-01
Po ilgo paie\\vskos laikotarpio, dr. N. Lietuvninkaitei padedant, KTU bibliotekos Ret? knyg? skyriaus kartografiniame archyve aptiktas 1915 m. JAV išleistas B. K. Balu?io M 1:252 000 Suvalkijos žem?lapis. Lietuvi? išeivijos instituto B. K. Balu?io fonde žem?lapio sudarymo medžiagos nerasta. Paie\\vska atrod? bevilti\\vska d?l tarpukario Lietuvi\\vskosios enciklopedijos klaidinan?ios informacijos, kad prasid?jus Pirmajam pasauliniam karui žem?lapis nebuvo išleistas, tad aprašomas ir publikuojamas pirm? kart?.
EDITAL DO PROCESSO DE SELEO PARA INGRESSO EM 2016 NOS CURSOS DE MESTRADO E DOUTORADO DO
Floeter, Sergio Ricardo
EDITAL DO PROCESSO DE SELEÇÃO PARA INGRESSO EM 2016 NOS CURSOS DE MESTRADO E DOUTORADO DO PROGRAMA candidatos aos Cursos de Mestrado e de Doutorado em Administração, para o período letivo que terá início em linha de pesquisa, destinadas aos portadores de diplomas de mestre, com curso realizado em instituição
REGIMENTO DO CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS, REA DE
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS, ÁREA DE CONCENTRAÇÃO EM MECÂNICA ESPACIAL E CONTROLE TÍTULO I DOS OBJETIVOS DO CURSO Art. 1o A Área de Concentração em Mecânica Espacial e Controle (CMC) do Curso de Pós-graduação em Engenharia e Tecnologia Espaciais (ETE) objetiva
REGIMENTO DO CURSO DE PS-GRADUAO EM ENGENHARIA E TECNOLOGIA ESPACIAIS
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM ENGENHARIA E GERENCIAMENTO DE SISTEMAS ESPACIAIS TÍTULO I DOS OBJETIVOS DO CURSO Art. 1º A Área de Concentração em Engenharia e Gerenciamento de Sistemas Espaciais (CSE) do Curso de Pós-graduação em Engenharia
EDITAL DE PROCESSO SELETIVO PARA INGRESSO EM 2015 NOS CURSOS DE MESTRADO E DOUTORADO DO
Hanazaki, Natalia
EDITAL DE PROCESSO SELETIVO PARA INGRESSO EM 2015 NOS CURSOS DE MESTRADO E DOUTORADO DO PROGRAMA DE candidatos aos Cursos de Mestrado e de Doutorado em Administração, para o período letivo que terá início em pesquisa, destinadas aos portadores de diplomas de mestre, com curso realizado em instituição reconhecida
Environmental Education and Development Division (EM-522). Annual report, Fiscal year 1993
Not Available
1993-12-31
The Environmental Education and Development Division (EM-522) is one of three divisions within the Office of Technology Integration and Environmental Education and Development (EM-52) in Environmental Restoration and Waste Management`s (EM`s) Office of Technology Development (EM-50). The primary design criterion for EM-522 education activities is directly related to meeting EM`s goal of environmental compliance on an accelerated basis and cleanup of the 1989 inventory of inactive sites and facilities by the year 2019. Therefore, EM-522`s efforts are directed specifically toward stimulating knowledge and capabilities to achieve the goals of EM while contributing to DOE`s overall goal of increasing scientific, mathematical, and technical literacy and competency. This report discusses fiscal year 1993 activities.
E.M. and Hadronic Shower Simulation with FLUKA
Battistoni, G.; Fasso, A.; Ferrari, A.; Ranft, J.; Rubbia, A.; Sala, P.R.; /INFN, Milan /SLAC /CERN /Siegen U. /Zurich, ETH
2005-10-03
A description of the main features of e.m. and hadronic shower simulation models used in the FLUKA code is summarized and some recent applications are discussed. The general status of the FLUKA project is also reported.
INSCRIO EM CURSO DE PS-GRADUAO DADOS PESSOAIS
INSCRIÇÃO EM CURSO DE PÓS-GRADUAÇÃO DADOS PESSOAIS: CURSO PRETENDIDO-MAIL:________________________________________________ RESUMO ESCOLAR (INICIAR PELO ÚLTIMO CURSO REALIZADO) ESCOLA INÍCIO TÉRMINO TÍTULO OBTIDO VINCULO EMPREGATICIO E DEDICAÇÃO AO CURSO: A) MANTERÁ VÍNCULO EMPREGATÍCIO DURANTE A REALIZAÇÃO DO CURSO
Application of EM stress sensors in large steel cables
NASA Astrophysics Data System (ADS)
Wang, Guodun; Wang, Ming L.; Zhao, Yang; Chen, Yong; Sun, Bingnan
2005-05-01
In this paper, the calibration and workability of magnetoelastic (ME or EM) stress sensors for large steel cables used in Qiangjiang 4th bridge in China are discussed. As an engineering application of magnetoelasticity, EM sensors make non-contact stress monitoring possible for steel hangers and post-tensioned cables on suspension and cable-stayed bridges, and other ferromagnetic structures. By quantifying the correlation of tension with magnetic properties represented by the relative permeability of the steel structure itself, the EM sensor inspects the loading level of the steel structure. The tension dependence of the relative permeability and the temperature influence was calibrated. The results revealed that the magnetoelasticity of the multi-wire hangers is consistent with one another, while the post-tensioned cables are similar to single wires. Cable stress monitoring on Qiangjiang (Qj) 4th bridge demonstrated the reliability of the EM sensors in safety evaluation of bridge.
An Effective EMS Hardware and Software Interface- The Trained Operator
Cherry, C. L.
1986-01-01
HARDWARE AND SOFTWARE THE TRAINED OPER~TQR Christene ~. Cherry Johnson Controls Institute INTERFACE Milwaukee, ABSTRAC'l' A computerized Energy Management Sys tem (EMS) is a tool that allows the user to moni tor and control building heating..., ventilation, and air conditioning equip ment (HVAC). All computerized tools require three main components to function effectively: hardware, software, and an interface between the two - the operator. EMS owners recognize the importance of proper system...
Geodesicas Nulas em Relatividade Geral Francisco Jo~ao Lopes
NatÃ¡rio, JosÃ©
GeodÂ´esicas Nulas em Relatividade Geral Francisco Jo~ao Lopes Instituto Superior TÂ´ecnico, LisboaÂ¸co de 2013 Resumo Pretende-se estudar raios de luz, ou seja, geodÂ´esicas nulas, em Relatividade GeralÂ´icio do sÂ´eculo XX, com a criaÂ¸c~ao da Teoria da Relatividade Restrita, por Einstein (que postulou que
Hanazaki, Natalia
escolha da nova diretoria da APP que será aberto em breve. Qualquer divergência, entre em contato. ASSOCIADOS APP PAIS/MÃES/RESPONSÁVEIS ATÉ SETEMBRO DE 2013 ASSOCIADOS - APP CA/UFSC 1. ABIGAIL SILVA DE
Análise da medição do raio solar em ultravioleta
NASA Astrophysics Data System (ADS)
Saraiva, A. C. V.; Giménez de Castro, C. G.; Costa, J. E. R.; Selhorst, C. L.; Simões, P. J. A.
2003-08-01
A medição acurada do raio solar em qualquer banda do espectro eletromagnético é de relevância na formulação e calibração de modelos da estrutura e atmosfera solar. Esses modelos atribuem emissão do contínuo do Sol calmo em microondas à mesma região da linha Ha do Hell. Apresentamos a medição do raio solar em UV com imagens do EIT (Extreme Ultraviolet Image Telescope) entre 1996 e 2002, no comprimento de onda 30,9 nm (Ha do Hell), que se forma na região de transição/cromosfera solar. A técnica utilizada para o cálculo do raio UV foi baseada na transformada Wavelet B3spline. Fizemos um banco de dados com 1 imagem por dia durante o período citado. Obtivemos como resultado o raio médio da ordem de 975.61" e uma diminuição do mesmo para o período citado variando em média -0,45" /ano. Comparamos estes dados com os valores obtidos pelo ROI (Radio Observatório de Itapetinga) em 22/48 GHz e Nobeyama Radio Heliograph em 17 GHz mostrando que os raios médios são muito próximos o que indica que a região de formação nessas freqüências é a mesma conforme os modelos. Comparamos os resultados também com outros índices de atividade solar.
EM Telemetry Tool for Deep Well Drilling Applications
Jeffrey M. Gabelmann
2005-11-15
This final report discusses the successful development and testing of a deep operational electromagnetic (EM) telemetry system, produced under a cooperative agreement with the United States Department of Energy's National Energy Technology Laboratory. This new electromagnetic telemetry system provides a wireless communication link between sensors deployed deep within oil and gas wells and data acquisition equipment located on the earth's surface. EM based wireless telemetry is a highly appropriate technology for oil and gas exploration in that it avoids the need for thousands of feet of wired connections. In order to achieve the project performance objectives, significant improvements over existing EM telemetry systems were made. These improvements included the development of new technologies that have improved the reliability of the communications link while extending operational depth. A key element of the new design is the incorporation of a data-fusion methodology which enhances the communication receiver's ability to extract very weak signals from large amounts of ambient environmental noise. This innovative data-fusion receiver based system adapts advanced technologies, not normally associated with low-frequency communications, and makes them work within the harsh drilling environments associated with the energy exploration market. Every element of a traditional EM telemetry system design, from power efficiency to reliability, has been addressed. The data fusion based EM telemetry system developed during this project is anticipated to provide an EM tool capability that will impact both onshore and offshore oil and gas exploration operations, for conventional and underbalanced drilling applications.
NASA Astrophysics Data System (ADS)
Wang, Xun; Quost, Benjamin; Chazot, Jean-Daniel; Antoni, Jérôme
2016-01-01
This paper considers the problem of identifying multiple sound sources from acoustical measurements obtained by an array of microphones. The problem is solved via maximum likelihood. In particular, an expectation-maximization (EM) approach is used to estimate the sound source locations and strengths, the pressure measured by a microphone being interpreted as a mixture of latent signals emitted by the sources. This work also considers two kinds of uncertainties pervading the sound propagation and measurement process: uncertain microphone locations and uncertain wavenumber. These uncertainties are transposed to the data in the belief functions framework. Then, the source locations and strengths can be estimated using a variant of the EM algorithm, known as the Evidential EM (E2M) algorithm. Eventually, both simulation and real experiments are shown to illustrate the advantage of using the EM in the case without uncertainty and the E2M in the case of uncertain measurement.
Išmatuot? aukš?i? skirtum? redukavimas ivertinant vertikaliuosius žem?s paviršiaus judesius
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Puzien?, R?ta
2010-01-01
Atliekant niveliavimo matavimus darbai dažnai t?siasi kelet? met?. D?l šios priežasties niveliavimo matavim? duomenims ?takos gali tur?ti vertikalieji Žem?s plutos judesiai. Siekiant išvengti šios ?takos, išmatuoti aukš?i? skirtumai turi b?ti redukuojami atsižvelgiant ? pasirinkt? epoch?. Tyrimai atlikti Lietuvos vertikaliojo geodezinio tinklo pavyzdžiu. Nustatyta, kad eksperimentiniame objekte niveliavimo matavimo rezultat? redukavimo, atsižvelgiant ? pasirinkt? epoch?, pataisos yra reikšmingos ir didesn?s už kitas apdorojant niveliavimo matavim? rezultatus skai?iuotas pataisas. Patais? d?l vertikali?j? Žem?s plutos judesi? ?tak? skai?iuoti niveliaciniuose ?jimuose rekomenduojama taikant regresinius vertikali?j? judesi? grei?i? prognozavimo arba judesi? grei?i? horizontali?j? gradient? modelius.
DOE EM industry programs robotics development
Staubly, R.; Kothari, V.
1998-12-31
The Office of Science and Technology (OST) manages an aggressive program for RD and D, as well as testing and evaluation for the Department of Energy`s (DOE`s) Environmental Management (EM) organization. The goal is to develop new and improved environmental restoration and waste management technologies to clean up the inventory of the DOE weapons complex faster, safer, and cheaper than is possible with currently available technologies. Robotic systems reduce worker exposure to the absolute minimum, while providing proven, cost-effective, and, for some applications, the only acceptable technique for addressing challenging problems. Development of robotic systems for remote operations occurs in three main categories: tank waste characterization and retrieval; decontamination and dismantlement; and characterization, mapping, and inspection systems. In addition, the Federal Energy Technology Center (FETC) has some other projects which fall under the heading of supporting R and D. The central objective of all FETC robotic projects is to make robotic systems more attractive by reducing costs and health risks associated with the deployment of robotic technologies in the cleanup of the nuclear weapons complex. This will be accomplished through development of robots that are cheaper, faster, safer, and more reliable, as well as more straightforward to modify/adapt and more intuitive to operate with autonomous capabilities and intelligent controls that prevent accidents and optimize task execution.
Instituto de Sistemas e Robotica
Resumo da Dissertação de Doutoramento em "Engenharia e Politicas Públicas" Os Incentivos à Energia a participação de fontes de energia renováveis na sua rede eléctrica. Portugal é um dos países líderes para a geração de energia eólica. A difusão do vento em Portugal começou no início de 2000 e em 2013 a geração de
FitEM2EM--tools for low resolution study of macromolecular assembly and dynamics.
Frankenstein, Ziv; Sperling, Joseph; Sperling, Ruth; Eisenstein, Miriam
2008-01-01
Studies of the structure and dynamics of macromolecular assemblies often involve comparison of low resolution models obtained using different techniques such as electron microscopy or atomic force microscopy. We present new computational tools for comparing (matching) and docking of low resolution structures, based on shape complementarity. The matched or docked objects are represented by three dimensional grids where the value of each grid point depends on its position with regard to the interior, surface or exterior of the object. The grids are correlated using fast Fourier transformations producing either matches of related objects or docking models depending on the details of the grid representations. The procedures incorporate thickening and smoothing of the surfaces of the objects which effectively compensates for differences in the resolution of the matched/docked objects, circumventing the need for resolution modification. The presented matching tool FitEM2EMin successfully fitted electron microscopy structures obtained at different resolutions, different conformers of the same structure and partial structures, ranking correct matches at the top in every case. The differences between the grid representations of the matched objects can be used to study conformation differences or to characterize the size and shape of substructures. The presented low-to-low docking tool FitEM2EMout ranked the expected models at the top. PMID:18974836
Degradation of Benzodiazepines after 120 Days of EMS Deployment
McMullan, Jason T.; Jones, Elizabeth; Barnhart, Bruce; Denninghoff, Kurt; Spaite, Daniel; Zaleski, Erin; Silbergleit, Robert
2014-01-01
Introduction EMS treatment of status epilepticus improves outcomes, but the benzodiazepine best suited for EMS use is unclear, given potential high environmental temperature exposures. Objective To describe the degradation of diazepam, lorazepam, and midazolam as a function of temperature exposure and time over 120 days of storage on active EMS units. Methods Study boxes containing vials of diazepam, lorazepam, and midazolam were distributed to 4 active EMS units in each of 2 EMS systems in the southwestern United States during May–August 2011. The boxes logged temperature every minute and were stored in EMS units per local agency policy. Two vials of each drug were removed from each box at 30-day intervals and underwent high-performance liquid chromatography to determine drug concentration. Concentration was analyzed as mean (and 95%CI) percent of initial labeled concentration as a function of time and mean kinetic temperature (MKT). Results 192 samples were collected (2 samples of each drug from each of 4 units per city at 4 time-points). After 120 days, the mean relative concentration (95%CI) of diazepam was 97.0% (95.7–98.2%) and of midazolam was 99.0% (97.7–100.2%). Lorazepam experienced modest degradation by 60 days (95.6% [91.6–99.5%]) and substantial degradation at 90 days (90.3% [85.2-95.4%]) and 120 days (86.5% [80.7–92.3%]). Mean MKT was 31.6°C (95%CI 27.1–36.1). Increasing MKT was associated with greater degradation of lorazepam, but not midazolam or diazepam. Conclusions Midazolam and diazepam experienced minimal degradation throughout 120 days of EMS deployment in high-heat environments. Lorazepam experienced significant degradation over 120 days and appeared especially sensitive to higher MKT exposure. PMID:24548058
Astronomia para/com crianças carentes em Limeira
NASA Astrophysics Data System (ADS)
Bretones, P. S.; Oliveira, V. C.
2003-08-01
Em 2001, o Instituto Superior de Ciências Aplicadas (ISCA Faculdades de Limeira) iniciou um projeto pelo qual o Observatório do Morro Azul empreendeu uma parceria com o Centro de Promoção Social Municipal (CEPROSOM), instituição mantida pela Prefeitura Municipal de Limeira para atender crianças e adolescentes carentes. O CEPROSOM contava com dois projetos: Projeto Centro de Convivência Infantil (CCI) e Programa Criança e Adolescente (PCA), que atendiam crianças e adolescentes em Centros Comunitários de diversas áreas da cidade. Esses projetos têm como prioridades estabelecer atividades prazerosas para as crianças no sentido de retirá-las das ruas. Assim sendo, as crianças passaram a ter mais um tipo de atividade - as visitas ao observatório. Este painel descreve as várias fases do projeto, que envolveu: reuniões de planejamento, curso de Astronomia para as orientadoras dos CCIs e PCAs, atividades relacionadas a visitas das crianças ao Observatório, proposta de construção de gnômons e relógios de Sol nos diversos Centros Comunitários de Limeira e divulgação do projeto na imprensa. O painel inclui discussões sobre a aprendizagem de crianças carentes, relatos que mostram a postura das orientadoras sobre a pertinência do ensino de Astronomia, relatos do monitor que fez o atendimento no Observatório e o que o número de crianças atendidas representou para as atividades da instituição desde o início de suas atividades e, em particular, em 2001. Os resultados são baseados na análise de relatos das orientadoras e do monitor do Observatório, registros de visitas e matérias da imprensa local. Conclui com uma avaliação do que tal projeto representou para as Instituições participantes. Para o Observatório, em particular, foi feita uma análise com relação às outras modalidades de atendimentos que envolvem alunos de escolas e público em geral. Também é abordada a questão do compromisso social do Observatório na educação do público em questão.
Emergency medical service (EMS): A unique flight environment
NASA Technical Reports Server (NTRS)
Shively, R. Jay
1993-01-01
The EMS flight environment is unique in today's aviation. The pilots must respond quickly to emergency events and often fly to landing zones where they have never been before . The time from initially receiving a call to being airborne can be as little as two to three minutes. Often the EMS pilot is the only aviation professional on site, they have no operations people or other pilots to aid them in making decisons. Further, since they are often flying to accident scenes, not airports, there is often complete weather and condition information. Therefore, the initial decision that the pilot must make, accepting or declining a flight, can become very difficult. The accident rate of EMS helicopters has been relatively high over the past years. NASA-Ames research center has taken several steps in an attempt to aid EMS pilots in their decision making and situational awareness. A preflight risk assessment system (SAFE) was developed to aid pilots in their decision making, and was tested at an EMS service. The resutls of the study were promising and a second version incorporating the lessons learned is under development. A second line of research was the development of a low cost electronic chart display (ECD). This is a digital map display to help pilots maintain geographical orientation. Another thrust was undertaken in conjunction with the Aviation Safety Reporting System (ASRS). This involved publicizing the ASRS to EMS pilots and personnel, and calling each of the reporters back to gather additional information. This paper will discuss these efforts and how they may positively impact the safety of EMS operations.
International Space Station (ISS) Emergency Mask (EM) Development
NASA Technical Reports Server (NTRS)
Toon, Katherine P.; Hahn, Jeffrey; Fowler, Michael; Young, Kevin
2011-01-01
The Emergency Mask (EM) is considered a secondary response emergency Personal Protective Equipment (PPE) designed to provide respiratory protection to the International Space Station (ISS) crewmembers in response to a post-fire event or ammonia leak. The EM is planned to be delivered to ISS in 2012 to replace the current air purifying respirator (APR) onboard ISS called the Ammonia Respirator (AR). The EM is a one ]size ]fits ]all model designed to fit any size crewmember, unlike the APR on ISS, and uses either two Fire Cartridges (FCs) or two Commercial Off-the-Shelf (COTS) 3M(Trademark). Ammonia Cartridges (ACs) to provide the crew with a minimum of 8 hours of respiratory protection with appropriate cartridge swap ]out. The EM is designed for a single exposure event, for either post ]fire or ammonia, and is a passive device that cannot help crewmembers who cannot breathe on their own. The EM fs primary and only seal is around the wearer fs neck to prevent a crewmember from inhaling contaminants. During the development of the ISS Emergency Mask, several design challenges were faced that focused around manufacturing a leak free mask. The description of those challenges are broadly discussed but focuses on one key design challenge area: bonding EPDM gasket material to Gore(Registered Trademark) fabric hood.
Torres-Verdín, Carlos
finite-difference (FD) modeling algorithm for computing frequency-domain electromagnetic (EM) fields electromagnetic (EM) phenomena in complex three- dimensional (3D) media, recently various EM finite-difference (FD
The Optimal Exponent Base for emPAI Is 6.5
Kudlicki, Andrzej
2012-01-01
Exponentially Modified Protein Abundance Index (emPAI) is an established method of estimating protein abundances from peptide counts in a single LC-MS/MS experiment. EmPAI is defined as 10PAI minus one, where PAI (Protein Abundance Index) denotes the ratio of observed to observable peptides. EmPAI was first proposed by Ishihama et al [1] who found that PAI is approximately proportional to the logarithm of absolute protein concentration. I define emPAI65?=?6.5PAI-1 and show that it performs significantly better than emPAI, while it is equally easy to compute. The higher accuracy of emPAI65 is demonstrated by analyzing three data sets, including the one used in the original study [1]. I conclude that emPAI65 ought to be used instead of the original emPAI for protein quantitation. PMID:22403647
0.5setgray00.5setgray1 Determinao de coeficientes em equaes
Cipolatti, Rolci
~ao tivessem sido previstas por James Clark Maxwell em 1862 e observadas experimentalmente por Heinrich Hertz~ao tivessem sido previstas por James Clark Maxwell em 1862 e observadas experimentalmente por Heinrich Hertz
Relatrio Final da licenciatura em Matemtica Aplicada e Computao
Cannas da Silva, Ana
-se a boa organizaÃ§Ã£o da visita que, conjuntamente com a clareza do RelatÃ³rio de Auto-AvaliaÃ§Ã£o, em muito docente (com melhorias em relaÃ§Ã£o Ã jÃ¡ boa situaÃ§Ã£o detectada no 1o ciclo de avaliaÃ§Ã£o), as boas condiÃ§Ãµes de trabalho, a qualidade dos candidatos e a boa relaÃ§Ã£o entre docentes e discentes. 2. A necessidade
EM-31 Alternative and Enhanced Chemical Cleaning Program
King, Bill
2010-11-01
King's introduction to his presentation made 5 important points: 1) Numerous SRS tanks scheduled for closure (contract commitments); 2) Cannot remove all sludge by mechanical means due to obstructions; 3) Chemical removal technology needed (likely oxalic acid); 4) Post - dissolution neutralization required prior to transfer to compliant tanks; 5) Sodium oxalate salts precipitate on neutralization and have negative downstream impacts. There were three SRS chemical cleaning programs in 2010: Baseline: 8wt percent OA batch contact, ECC: 1-3 wt. percent OA with oxalate destruction, and the Alternative/Enhanced Chemical Cleaning (EM-31). This talk is on the EM-31 program.
Low Bandwidth Vocoding using EM Sensor and Acoustic Signal Processing
Ng, L C; Holzrichter, J F; Larson, P E
2001-10-25
Low-power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference [1]. By combining these data with the corresponding acoustic signal, we've demonstrated an almost 10-fold bandwidth reduction in speech compression, compared to a standard 2.4 kbps LPC10 protocol used in the STU-III (Secure Terminal Unit, third generation) telephone. This paper describes a potential EM sensor/acoustic based vocoder implementation.
Speaker verification using combined acoustic and EM sensor signal processing
Ng, L C; Gable, T J; Holzrichter, J F
2000-11-10
Low Power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference. This greatly enhances the quality and quantity of information for many speech related applications. See Holzrichter, Burnett, Ng, and Lea, J. Acoustic. SOC. Am . 103 ( 1) 622 (1998). By combining the Glottal-EM-Sensor (GEMS) with the Acoustic-signals, we've demonstrated an almost 10 fold reduction in error rates from a speaker verification system experiment under a moderate noisy environment (-10dB).
SE1EM11 Differentiation and Integration Part A Dr Richard Mitchell, 2014 1
Mitchell, Richard
SE1EM11 Differentiation and Integration Part A © Dr Richard Mitchell, 2014 1 p1 RJM 10/09/14 SE1EM11 Differentiation and Integration Part A © Dr Richard Mitchell 2014 SE1EM11 - Engineering Maths Dr will see maths applied in module SE1CC11, for instance p2 RJM 10/09/14 SE1EM11 Differentiation
Simpsio de Ps-Graduao O gnero de terror em perspectivas tericas
Floeter, Sergio Ricardo
:30 * "What's this?": elementos de horror e humor em O Estranho Mundo de Jack Ana Olivo (UFSC) * "Burn the Witch!": a bruxa enquanto o Outro em Penny Dreadful Yasmim Pereira Yonekura (UFSC) * Terror/Horror: análise de dois episódios de Sherlock em luz das definições de horror/terror Patrícia Bronislawski (UFSC
EmSe: Supporting Children's Information Needs within a Hospital Environment
Theune, MariÃ«t
Vries PuppyIR http://www.puppyir.eu Abstract. The Emma Search (EmSe) demonstrator developed for the Emma Children's Hospital showcases the PuppyIR project and PuppyIR framework for building information services via the web. 2 The EmSe Service EmSe is built using the PuppyIR Framework [3], which provides a suite
ICE-EM RNSA 2007 Workshop on Pairing Based Cryptography 1 Certificateless Cryptography II
Paterson, Kenny
ICE-EM RNSA 2007 Workshop on Pairing Based Cryptography 1 Certificateless Cryptography II Kenny 2007 Information Security Group Royal Holloway, University of London #12;ICE-EM RNSA 2007 Workshop Security Group Royal Holloway, University of London #12;ICE-EM RNSA 2007 Workshop on Pairing Based
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PS-GRADUAO EM AGROECOSSISTEMAS
Floeter, Sergio Ricardo
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PÓS-GRADUAÇÃO EM AGROECOSSISTEMAS EDITAL 002/MPA-CCA/2015 MESTRADO PROFISSIONAL EM AGROECOSSISTEMAS O coordenador do curso de Pós-Graduação Mestrado da graduação em 2015, emitida pela respectiva secretaria do curso. Florianópolis, 08 de outubro de
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PS-GRADUAO EM AGROECOSSISTEMAS
Floeter, Sergio Ricardo
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PÓS-GRADUAÇÃO EM AGROECOSSISTEMAS EDITAL 003/MPA-CCA/2015 MESTRADO PROFISSIONAL EM AGROECOSSISTEMAS O coordenador do curso de Pós-Graduação Mestrado. Profº. Dr. Clarilton Edzard Davoine Cardoso Ribas Coordenador do Curso de Mestrado Profissional em
COLOR IMAGE SEGMENTATION USING A SELF-INITIALIZING EM Dana Elena Ilea and Paul F. Whelan
Whelan, Paul F.
COLOR IMAGE SEGMENTATION USING A SELF-INITIALIZING EM ALGORITHM Dana Elena Ilea and Paul F. Whelan-Maximization (EM) algorithm that we apply for color image segmentation. Since this algorithm partitions the data based on an initial set of mixtures, the color segmentation provided by the EM algorithm is highly
Optomechanical creation of magnetic fields for photons on a lattice
M. Schmidt; S. Keßler; V. Peano; O. Painter; F. Marquardt
2015-02-26
We propose using the optomechanical interaction to create artificial magnetic fields for photons on a lattice. The ingredients required are an optomechanical crystal, i.e. a piece of dielectric with the right pattern of holes, and two laser beams with the right pattern of phases. One of the two proposed schemes is based on optomechanical modulation of the links between optical modes, while the other is an lattice extension of optomechanical wavelength-conversion setups. We illustrate the resulting optical spectrum, photon transport in the presence of an artificial Lorentz force, edge states, and the photonic Aharonov-Bohm effect. Moreover, wWe also briefly describe the gauge fields acting on the synthetic dimension related to the phonon/photon degree of freedom. These can be generated using a single laser beam impinging on an optomechanical array.
Experimental Demonstration of a Synthetic Lorentz Force by Using Radiation Pressure.
Šanti?, N; Dub?ek, T; Aumiler, D; Buljan, H; Ban, T
2015-01-01
Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employing the analogy between the Berry phase and the Aharonov-Bohm phase. Interestingly, radiation pressure - being one of the most common forces induced by light - has not yet been used for synthetic magnetism. We experimentally demonstrate a synthetic Lorentz force, based on the radiation pressure and the Doppler effect, by observing the centre-of-mass motion of a cold atomic cloud. The force is perpendicular to the velocity of the cold atomic cloud, and zero for the cloud at rest. Our novel concept is straightforward to implement in a large volume, for a broad range of velocities, and can be extended to different geometries. PMID:26330327
Nonradiating anapole modes in dielectric nanoparticles
Miroshnichenko, Andrey E.; Evlyukhin, Andrey B.; Yu, Ye Feng; Bakker, Reuben M.; Chipouline, Arkadi; Kuznetsov, Arseniy I.; Luk'yanchuk, Boris; Chichkov, Boris N.; Kivshar, Yuri S.
2015-01-01
Nonradiating current configurations attract attention of physicists for many years as possible models of stable atoms. One intriguing example of such a nonradiating source is known as ‘anapole'. An anapole mode can be viewed as a composition of electric and toroidal dipole moments, resulting in destructive interference of the radiation fields due to similarity of their far-field scattering patterns. Here we demonstrate experimentally that dielectric nanoparticles can exhibit a radiationless anapole mode in visible. We achieve the spectral overlap of the toroidal and electric dipole modes through a geometry tuning, and observe a highly pronounced dip in the far-field scattering accompanied by the specific near-field distribution associated with the anapole mode. The anapole physics provides a unique playground for the study of electromagnetic properties of nontrivial excitations of complex fields, reciprocity violation and Aharonov–Bohm like phenomena at optical frequencies. PMID:26311109
Magnetic flux tuning of Fano-Kondo interplay in a parallel double quantum dot system
NASA Astrophysics Data System (ADS)
Agundez, R. R.; Verduijn, J.; Rogge, S.; Blaauboer, M.
2013-06-01
We investigate the Fano-Kondo interplay in an Aharonov-Bohm ring with an embedded noninteracting quantum dot and a Coulomb interacting quantum dot. Using a slave-boson mean-field approximation we diagonalize the Hamiltonian via scattering matrix theory and derive the conductance in the form of a Fano expression, which depends on the mean-field parameters. We predict that in the Kondo regime the magnetic field leads to a gapped energy level spectrum due to hybridization of the noninteracting QD state and the Kondo state, and can quantum-mechanically alter the electron's path preference. We demonstrate that an abrupt symmetry change in the Fano resonance, as seen experimentally, could be a consequence of an underlying Kondo channel.
Non-local coupling of two donor-bound electrons
NASA Astrophysics Data System (ADS)
Verduijn, J.; Agundez, R. R.; Blaauboer, M.; Rogge, S.
2013-03-01
We report the results of an experiment investigating coherence and correlation effects in a system of coupled donors. Two donors are strongly coupled to two leads in a parallel configuration within a nano-wire field effect transistor. By applying a magnetic field we observe interference between two donor-induced Kondo channels, which depends on the Aharonov-Bohm phase picked up by electrons traversing the structure. This results in a non-monotonic conductance as a function of magnetic field and clearly demonstrates that donors can be coupled through a many-body state in a coherent manner. We present a model which shows good qualitative agreement with our data. The presented results add to the general understanding of interference effects in a donor-based correlated system which may allow us to create artificial lattices that exhibit exotic many-body excitations.
Cosmic strings in hidden sectors: 1. Radiation of standard model particles
Long, Andrew J.; Hyde, Jeffrey M.; Vachaspati, Tanmay E-mail: jmhyde@asu.edu
2014-09-01
In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant cosmic strings to Standard Model particles. We calculate the spectrum of radiation emitted by these ''dark strings'' in the form of Higgs bosons, Z bosons, and Standard Model fermions assuming that string tension is above the TeV scale. We also calculate the scattering cross sections of Standard Model fermions on dark strings due to the Aharonov-Bohm interaction. These radiation and scattering calculations will be applied in a subsequent paper to study the cosmological evolution and observational signatures of dark strings.
Geometric diffusion of quantum trajectories
Yang, Fan; Liu, Ren-Bao
2015-01-01
A quantum object can acquire a geometric phase (such as Berry phases and Aharonov–Bohm phases) when evolving along a path in a parameter space with non-trivial gauge structures. Inherent to quantum evolutions of wavepackets, quantum diffusion occurs along quantum trajectories. Here we show that quantum diffusion can also be geometric as characterized by the imaginary part of a geometric phase. The geometric quantum diffusion results from interference between different instantaneous eigenstate pathways which have different geometric phases during the adiabatic evolution. As a specific example, we study the quantum trajectories of optically excited electron-hole pairs in time-reversal symmetric insulators, driven by an elliptically polarized terahertz field. The imaginary geometric phase manifests itself as elliptical polarization in the terahertz sideband generation. The geometric quantum diffusion adds a new dimension to geometric phases and may have applications in many fields of physics, e.g., transport in topological insulators and novel electro-optical effects. PMID:26178745
Colloquium: Artificial gauge potentials for neutral atoms
Dalibard, Jean; Gerbier, Fabrice; Juzeliunas, Gediminas; Oehberg, Patrik
2011-10-01
When a neutral atom moves in a properly designed laser field, its center-of-mass motion may mimic the dynamics of a charged particle in a magnetic field, with the emergence of a Lorentz-like force. In this Colloquium the physical principles at the basis of this artificial (synthetic) magnetism are presented. The corresponding Aharonov-Bohm phase is related to the Berry's phase that emerges when the atom adiabatically follows one of the dressed states of the atom-laser interaction. Some manifestations of artificial magnetism for a cold quantum gas, in particular, in terms of vortex nucleation are discussed. The analysis is then generalized to the simulation of non-Abelian gauge potentials and some striking consequences are presented, such as the emergence of an effective spin-orbit coupling. Both the cases of bulk gases and discrete systems, where atoms are trapped in an optical lattice, are addressed.
Quantum electrical transport properties of topological insulator Bi2Te3 nanowires
NASA Astrophysics Data System (ADS)
Kim, Hong-Seok; Shin, Ho Sun; Lee, Joon Sung; Ahn, Chi Won; Song, Jae Yong; Doh, Yong-Joo
2016-01-01
We investigate the quantum transport properties of surface electrons on a topological insulator Bi2Te3 nanowire in a magnetotransport study. Although the nanowires are synthesized by using a relatively coarse method of electrochemical deposition, clear Aharonov-Bohm oscillations of phases 0 and pi are observed, owing to the highly coherent surface electron channel. The oscillation amplitude exhibits exponential temperature dependence, suggesting that the phase coherence length L_phi is inversely proportional to the temperature, as in quasi-ballistic systems. In addition, a weak antilocalization analysis on the surface channel by using a one-dimensional localization theory, enabled by successful extraction of the surface contribution from the magnetoconductance data, is provided in support of the temperature dependence of L_phi.
Experimental Demonstration of a Synthetic Lorentz Force by Using Radiation Pressure
Šanti?, N; Aumiler, D; Buljan, H; Ban, T
2015-01-01
Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employing the analogy between the Berry phase and the Aharonov-Bohm phase. Interestingly, radiation pressure - being one of the most common forces induced by light - has not yet been used for synthetic magnetism. We experimentally demonstrate a synthetic Lorentz force, based on the radiation pressure and the Doppler effect, by observing the centre-of-mass motion of a cold atomic cloud. The force is perpendicular to the velocity of the cold atomic cloud, and zero for the cloud at rest. Our novel concept is straightforward to implement in a large volume, for a broad range of velocities, and can be extended to different geometries.
Electric field geometries dominate quantum transport coupling in silicon nanoring
Lee, Tsung-Han E-mail: sfhu.hu@gmail.com; Hu, Shu-Fen E-mail: sfhu.hu@gmail.com
2014-03-28
Investigations on the relation between the geometries of silicon nanodevices and the quantum phenomenon they exhibit, such as the Aharonov–Bohm (AB) effect and the Coulomb blockade, were conducted. An arsenic doped silicon nanoring coupled with a nanowire by electron beam lithography was fabricated. At 1.47?K, Coulomb blockade oscillations were observed under modulation from the top gate voltage, and a periodic AB oscillation of ?B?=?0.178?T was estimated for a ring radius of 86?nm under a high sweeping magnetic field. Modulating the flat top gate and the pointed side gate was performed to cluster and separate the many electron quantum dots, which demonstrated that quantum confinement and interference effects coexisted in the doped silicon nanoring.
A non-qubit quantum adder as one-dimensional cellular automaton
NASA Astrophysics Data System (ADS)
Wu, C. H.; Cain, C. A.
2014-05-01
A complete quantum addition machine is presented and compared with methods employing unitary transformations first. A quantum half-adder circuit shown earlier can be implemented into each cell of a 1D cellular automaton. An electric Aharonov-Bohm effect version of the quantum circuit is used to illustrate this implementation. Whatever a quantum Turing machine can achieve is realized in the cellular automata architecture we propose here. The coherence requirement is limited to one cell area. The magnetic flux needed is 0.1?0, corresponding to 0.414 mT for a ring area of 1 square micron or an electric potential of 0.414 mV at 1 ps with an energy dissipation of 0.041 eV per iteration.
Spin-dependent coherent transport in a double quantum dot system
NASA Astrophysics Data System (ADS)
Petrosyan, L. S.; Shahbazyan, T. V.
2015-09-01
We study spin-resolved resonant tunneling in a system of two quantum dots sandwiched between doped quantum wells. In the coherent (Dicke) regime, i.e., when quantum dot separation is smaller than the Fermi wavelength in a two-dimensional electron gas in quantum wells, application of an in-plane magnetic field leads to a pronounced spin-resolved structure of conductance peak line shape even for very small Zeeman splitting of the quantum dots' resonant levels. In the presence of electron-gas spin-orbit coupling, this spin-resolved structure is washed out due to Fermi surface deformation in the momentum space. We also show that Aharonov-Bohm flux penetrating the area enclosed by tunneling electron pathways completely destroys the conductance spin structure.
Dynamical features of interference phenomena in the presence of entanglement
Kaufherr, T.; Aharonov, Y.; Nussinov, S.; Popescu, S.; Tollaksen, J.
2011-05-15
A strongly interacting, and entangling, heavy nonrecoiling external particle effects a significant change of the environment. Described locally, the corresponding entanglement event is a generalized electric Aharonov-Bohm effect, which differs from the original one in a crucial way. We propose a gedanken interference experiment. The predicted shift of the interference pattern is due to a self-induced or ''private'' potential difference experienced while the particle is in vacuum. We show that all nontrivial Born-Oppenheimer potentials are ''private'' potentials. We apply the Born-Oppenheimer approximation to interference states. Using our approach, we calculate the relative phase of the external heavy particle as well as its uncertainty throughout an interference experiment or entanglement event. We thus complement the Born-Oppenheimer approximation for interference states.
Quantum Phase Coherence in Mesoscopic Transport Devices with Two-Particle Interaction
Wang, Zhimei; Guo, Xiaofang; Xue, Haibin; Xue, Naitao; Liang, J.-Q.
2015-01-01
In this paper we demonstrate a new type of quantum phase coherence (QPC), which is generated by the two-body interaction. This conclusion is based on quantum master equation analysis for the full counting statistics of electron transport through two parallel quantum-dots with antiparallel magnetic fluxes in order to eliminate the Aharonov-Bohm interference of either single-particle or non-interacting two-particle wave functions. The interacting two-particle QPC is realized by the flux-dependent oscillation of the zero-frequency cumulants including the shot noise and skewness with a characteristic period. The accurately quantized peaks of cumulant spectrum may have technical applications to probe the two-body Coulomb interaction. PMID:26255858
An Extended Dynamical Equation of Motion, Phase Dependency and Inertial Backreaction
Pinheiro, Mario J
2012-01-01
Newton's second law has limited scope of application when transient phenomena are present. We consider a modification of Newton's second law in order to take into account a sudden change (surge) of angular momentum or linear momentum. We hypothesize that space itself resists such surges according to a kind of induction law (related to inertia); additionally, we provide further evidence of the "fluidic" nature of space itself. This "back-reaction" is quantified by the tendency of angular momentum flux threading across a surface. This quantity is mass-dependent, and bears similarity to the quantum mechanics phase shift, present in the Aharonov-Bohm and Aharonov-Casher effects. Furthermore, this provides evidence of vacuum polarization, a phenomena which is relative to local space indicating that local geometry and topology should be taken into account in any fundamental physical theory.
Dirac bound states of anharmonic oscillator in external fields
Hamzavi, Majid; Ikhdair, Sameer M.; Falaye, Babatunde J.
2014-02-15
We explore the effect of the external magnetic and Aharonov–Bohm (AB) flux fields on the energy levels of Dirac particle subjects to mixed scalar and vector anharmonic oscillator field in the two-dimensional (2D) space. We calculate the exact energy eigenvalues and the corresponding un-normalized two-spinor-components wave functions in terms of the chemical potential parameter, magnetic field strength, AB flux field and magnetic quantum number by using the Nikiforov–Uvarov (NU) method. -- Highlights: • Effect of the external fields on the energy levels of Dirac particle with the anharmonic oscillator is investigated. • The solutions are discussed in view of spin and pseudospin symmetries limits. • The energy levels and wave function are presented by the Nikiforov–Uvarov method.
A. V. Ghazaryan; A. P. Djotyan; K. Moulopoulos; A. A. Kirakosyan
2011-03-03
The problem of an electron-hole system interacting through a contact potential and moving in a one-dimensional quantum ring threaded by an Aharonov-Bohm flux is considered, both with respect to the system's energetics as well as its optical properties. An exact analytical expression for the energy spectrum is derived using a straightforward method based on boundary conditions for wavefunctions and their derivatives along the ring. The optical properties of this exciton system, namely the linear dynamic polarizability and absorption spectrum are investigated demonstrating certain unusual features. It is shown, for example, that for special values of the magnetic flux there are energies in the spectrum that correspond to the dark excitonic states.
Omidi, Mahboubeh Faizabadi, Edris
2015-03-21
Magnetic susceptibility is investigated in a man-made elliptical quantum ring in the presence of Rashba spin-orbit interactions and the magnetic flux. It is shown that magnetic susceptibility as a function of magnetic flux changes between negative and positive signs periodically. The periodicity of the Aharonov-Bohm oscillations depends on the geometry of the region where magnetic field is applied, the eccentricity, and number of sites in each chain ring (the elliptical ring is composed of chain rings). The magnetic susceptibility sign can be reversed by tuning the Rashba spin-orbit strength as well. Both the magnetic susceptibility strength and sign can be controlled via external spin-orbit interactions, which can be exploited in spintronics and nanoelectronics.
NASA Astrophysics Data System (ADS)
Bäßler, Svenja; Hamdou, Bacel; Sergelius, Philip; Michel, Ann-Kathrin; Zierold, Robert; Reith, Heiko; Gooth, Johannes; Nielsch, Kornelius
2015-11-01
The geometry of topological insulators (TIs) has a major impact on the magnetoelectric band structure of their surface states. Here, we investigate the surface states of cylindrical TI bismuth telluride selenide nanowires with three different diameters, by parallel and transverse magnetoresistance (MR) measurements. In parallel configuration, we observe Aharonov-Bohm oscillations as well as weak antilocalization, indicating two-dimensional TI surface states. In transverse magnetic fields, we observed MR oscillations that are non-linear against the reciprocal of the magnetic field and thus cannot be explained by two- or three-dimensional states. Instead, our transport data analysis reveals that these MR oscillations are the consequence of one-dimensional edge channels at the nanowire surface that form due to the projection of the external magnetic field on the cylindrically curved surface plane in high magnetic fields. Our observation provides an exotic class of surface states that might be used for electronic and spintronic devices.
Transport of Massless Dirac Fermions in Non-topological Type Edge States
NASA Astrophysics Data System (ADS)
Latyshev, Yu I.; Orlov, A. P.; Volkov, V. A.; Enaldiev, V. V.; Zagorodnev, I. V.; Vyvenko, O. F.; Petrov, Yu V.; Monceau, P.
2014-12-01
There are two types of intrinsic surface states in solids. The first type is formed on the surface of topological insulators. Recently, transport of massless Dirac fermions in the band of ``topological'' states has been demonstrated. States of the second type were predicted by Tamm and Shockley long ago. They do not have a topological background and are therefore strongly dependent on the properties of the surface. We study the problem of the conductivity of Tamm-Shockley edge states through direct transport experiments. Aharonov-Bohm magneto-oscillations of resistance are found on graphene samples that contain a single nanohole. The effect is explained by the conductivity of the massless Dirac fermions in the edge states cycling around the nanohole. The results demonstrate the deep connection between topological and non-topological edge states in 2D systems of massless Dirac fermions.
Transport of massless Dirac fermions in non-topological type edge states.
Latyshev, Yu I; Orlov, A P; Volkov, V A; Enaldiev, V V; Zagorodnev, I V; Vyvenko, O F; Petrov, Yu V; Monceau, P
2014-01-01
There are two types of intrinsic surface states in solids. The first type is formed on the surface of topological insulators. Recently, transport of massless Dirac fermions in the band of "topological" states has been demonstrated. States of the second type were predicted by Tamm and Shockley long ago. They do not have a topological background and are therefore strongly dependent on the properties of the surface. We study the problem of the conductivity of Tamm-Shockley edge states through direct transport experiments. Aharonov-Bohm magneto-oscillations of resistance are found on graphene samples that contain a single nanohole. The effect is explained by the conductivity of the massless Dirac fermions in the edge states cycling around the nanohole. The results demonstrate the deep connection between topological and non-topological edge states in 2D systems of massless Dirac fermions. PMID:25524881
Transport of Massless Dirac Fermions in Non-topological Type Edge States
Latyshev, Yu I.; Orlov, A. P.; Volkov, V. A.; Enaldiev, V. V.; Zagorodnev, I. V.; Vyvenko, O. F.; Petrov, Yu V.; Monceau, P.
2014-01-01
There are two types of intrinsic surface states in solids. The first type is formed on the surface of topological insulators. Recently, transport of massless Dirac fermions in the band of “topological” states has been demonstrated. States of the second type were predicted by Tamm and Shockley long ago. They do not have a topological background and are therefore strongly dependent on the properties of the surface. We study the problem of the conductivity of Tamm-Shockley edge states through direct transport experiments. Aharonov-Bohm magneto-oscillations of resistance are found on graphene samples that contain a single nanohole. The effect is explained by the conductivity of the massless Dirac fermions in the edge states cycling around the nanohole. The results demonstrate the deep connection between topological and non-topological edge states in 2D systems of massless Dirac fermions. PMID:25524881
Nonradiating anapole modes in dielectric nanoparticles.
Miroshnichenko, Andrey E; Evlyukhin, Andrey B; Yu, Ye Feng; Bakker, Reuben M; Chipouline, Arkadi; Kuznetsov, Arseniy I; Luk'yanchuk, Boris; Chichkov, Boris N; Kivshar, Yuri S
2015-01-01
Nonradiating current configurations attract attention of physicists for many years as possible models of stable atoms. One intriguing example of such a nonradiating source is known as 'anapole'. An anapole mode can be viewed as a composition of electric and toroidal dipole moments, resulting in destructive interference of the radiation fields due to similarity of their far-field scattering patterns. Here we demonstrate experimentally that dielectric nanoparticles can exhibit a radiationless anapole mode in visible. We achieve the spectral overlap of the toroidal and electric dipole modes through a geometry tuning, and observe a highly pronounced dip in the far-field scattering accompanied by the specific near-field distribution associated with the anapole mode. The anapole physics provides a unique playground for the study of electromagnetic properties of nontrivial excitations of complex fields, reciprocity violation and Aharonov-Bohm like phenomena at optical frequencies. PMID:26311109
Neutron in a Strong Magnetic Field: Finite Volume Effects
Tiburzi, Brian C
2014-01-01
We investigate the neutron's response to magnetic fields on a torus with the aid of chiral perturbation theory, and expose effects from non-vanishing holonomies. The determination of such effects necessitates non-perturbative treatment of the magnetic field; and, to this end, a strong-field power counting is employed. Using a novel coordinate-space method, we find the neutron propagates in a coordinate-dependent effective potential that we obtain by integrating out charged pions winding around the torus. Knowledge of these finite volume effects will aid in the extraction of neutron properties from lattice QCD computations in external magnetic fields. In particular, we obtain finite volume corrections to the neutron magnetic moment and magnetic polarizability. These quantities have not been computed correctly in the literature. In addition to effects from non-vanishing holonomies, finite volume corrections depend on the magnetic flux quantum through an Aharonov-Bohm effect. We make a number of observations tha...
Topologically protected excitons in porphyrin thin films.
Yuen-Zhou, Joel; Saikin, Semion K; Yao, Norman Y; Aspuru-Guzik, Alán
2014-11-01
The control of exciton transport in organic materials is of fundamental importance for the development of efficient light-harvesting systems. This transport is easily deteriorated by traps in the disordered energy landscape. Here, we propose and analyse a system that supports topological Frenkel exciton edge states. Backscattering of these chiral Frenkel excitons is prohibited by symmetry, ensuring that the transport properties of such a system are robust against disorder. To implement our idea, we propose a two-dimensional periodic array of tilted porphyrins interacting with a homogeneous magnetic field. This field serves to break time-reversal symmetry and results in lattice fluxes that mimic the Aharonov-Bohm phase acquired by electrons. Our proposal is the first blueprint for realizing topological phases of matter in molecular aggregates and suggests a paradigm for engineering novel excitonic materials. PMID:25242533
Realization of the Hofstadter Hamiltonian with ultracold atoms in optical lattices
M. Aidelsburger; M. Atala; M. Lohse; J. T. Barreiro; B. Paredes; I. Bloch
2013-09-07
We demonstrate the experimental implementation of an optical lattice that allows for the generation of large homogeneous and tunable artificial magnetic fields with ultracold atoms. Using laser-assisted tunneling in a tilted optical potential we engineer spatially dependent complex tunneling amplitudes. Thereby atoms hopping in the lattice accumulate a phase shift equivalent to the Aharonov-Bohm phase of charged particles in a magnetic field. We determine the local distribution of fluxes through the observation of cyclotron orbits of the atoms on lattice plaquettes, showing that the system is described by the Hofstadter model. Furthermore, we show that for two atomic spin states with opposite magnetic moments, our system naturally realizes the time-reversal symmetric Hamiltonian underlying the quantum spin Hall effect, i.e., two different spin components experience opposite directions of the magnetic field.
Flux sensitivity of quantum spin Hall rings
NASA Astrophysics Data System (ADS)
Crépin, F.; Trauzettel, B.
2016-01-01
We analyze the periodicity of persistent currents in quantum spin Hall loops, partly covered with an s-wave superconductor, in the presence of a flux tube. Much like in normal (non-helical) metals, the periodicity of the single-particle spectrum goes from ?0 = h / e to ?0 / 2 as the length of the superconductor is increased past the coherence length of the superconductor. We further analyze the periodicity of the persistent current, which is a many-body effect. Interestingly, time reversal symmetry and parity conservation can significantly change the period. We find a 2?0-periodic persistent current in two distinct regimes, where one corresponds to a Josephson junction and the other one to an Aharonov-Bohm setup.
Engineering massive quantum memories by topologically time-modulated spin rings
S. M. Giampaolo; F. Illuminati; A. Di Lisi; S. De Siena
2006-01-24
We introduce a general scheme to realize perfect storage of quantum information in systems of interacting qubits. This novel approach is based on {\\it global} external controls of the Hamiltonian, that yield time-periodic inversions in the dynamical evolution, allowing a perfect periodic quantum state recontruction. We illustrate the method in the particularly interesting and simple case of spin systems affected by XY residual interactions with or without static imperfections. The global control is achieved by step time-inversions of an overall topological phase of the Aharonov-Bohm type. Such a scheme holds both at finite size and in the thermodynamic limit, thus enabling the massive storage of arbitrarily large numbers of local states, and is stable against several realistic sources of noise and imperfections.
Experimental Demonstration of a Synthetic Lorentz Force by Using Radiation Pressure
Šanti?, N.; Dub?ek, T.; Aumiler, D.; Buljan, H.; Ban, T.
2015-01-01
Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employing the analogy between the Berry phase and the Aharonov-Bohm phase. Interestingly, radiation pressure - being one of the most common forces induced by light - has not yet been used for synthetic magnetism. We experimentally demonstrate a synthetic Lorentz force, based on the radiation pressure and the Doppler effect, by observing the centre-of-mass motion of a cold atomic cloud. The force is perpendicular to the velocity of the cold atomic cloud, and zero for the cloud at rest. Our novel concept is straightforward to implement in a large volume, for a broad range of velocities, and can be extended to different geometries. PMID:26330327
Suppression of Spin-Orbit Scattering in the Strongly Localized Regime
NASA Astrophysics Data System (ADS)
Davidovic, Dragomir; Anaya, Armando; Korotkov, Andrei; Bowman, Michael
2004-03-01
We present measurements of magnetofingerprints in gold nanojunctions with strongly disordered leads. At low temperatures, the leads undergo Anderson localization transition. A linear structure in conductance versus magnetic field B and bias voltage V is observed at low temperatures: the conductance is constant when eV+2mB ot eV-2mB is constant, where m is the Bohr magnetron. This observation proves that magnetofingerprints are spin based, in contrast to magnetofingerprints of weakly disordered metals, which are based on the Aharonov-Bohm effect. From the Thouless energy we obtain that the spin-orbit scattering time is more than four orders of magnitude longer than that expected from the Elliot-Yafett relation. The suppression of the spin-orbit scattering is explained in terms of the zero-dimmensional character of the electronic wavefunctions. This research is supported by the David and Lucile Packard Foundation grant 2000-13874.
(Research in the theory of condensed matter and elementary particles. ) Progress report
Not Available
1986-01-01
Progress is summarized in these areas: a new formulation of two dimensional critical phenomena and string theory, supersymmetric critical phenomena and string compactification, conformal field theory on orbifolds, Gaussian models with twisted boundary conditions, modular invariance and supersymmetric critical phenomena, critical indices, conformal invariance, and current algebra, renormalization group fixed points and the string equation of motion, fermionic string field theory, N = 2 super Riemann surfaces, the spinor field in covariant superstring theory, covariant quantization of superstrings, models of aggregation, and quasi-supersymmetry in the BCS mechanism. Further work is proposed in the areas of two dimensional critical phenomena, two dimensional conformal field theory and string theory, the physics of computation, models of aggregation, and the many vortex Aharonov-Bohm problem. 57 refs. (LEW)
Aharonov-Anandan quantum phases and Landau quantization associated with a magnetic quadrupole moment
NASA Astrophysics Data System (ADS)
Fonseca, I. C.; Bakke, K.
2015-12-01
The arising of geometric quantum phases in the wave function of a moving particle possessing a magnetic quadrupole moment is investigated. It is shown that an Aharonov-Anandan quantum phase (Aharonov and Anandan, 1987) can be obtained in the quantum dynamics of a moving particle with a magnetic quadrupole moment. In particular, it is obtained as an analogue of the scalar Aharonov-Bohm effect for a neutral particle (Anandan, 1989). Besides, by confining the quantum particle to a hard-wall confining potential, the dependence of the energy levels on the geometric quantum phase is discussed and, as a consequence, persistent currents can arise from this dependence. Finally, an analogue of the Landau quantization is discussed.
NASA Astrophysics Data System (ADS)
Onorato, P.
2011-03-01
An introduction to quantum mechanics based on the sum-over-paths (SOP) method originated by Richard P Feynman and developed by E F Taylor and coworkers is presented. The Einstein-Brillouin-Keller (EBK) semiclassical quantization rules are obtained following the SOP approach for bounded systems, and a general approach to the calculation of propagation amplitude is discussed for unbounded systems. These semiclassical results are obtained when the SOP is limited to the trajectories classically allowed. EBK semiclassical quantization and the topological Maslov index are used to deduce the correct quantum mechanical results for systems which live in a two-dimensional world as quantum dots and quantum rings. In the latter systems, the semiclassical propagation amplitude is used to discuss the Aharonov-Bohm effect. The development involves only elementary calculus and also provides a theoretical introduction to the quantum nature of low-dimensional nanostructures.
Is Quantum Mechanics Incompatible with Newton's First Law
Mario Rabinowitz
2008-04-11
Quantum mechanics (QM) clearly violates Newton's First Law of Motion (NFLM) in the quantum domain for one of the simplest problems, yielding an effect in a force-free region much like the Aharonov-Bohm effect. In addition, there is an incompatibility between the predictions of QM in the classical limit, and that of classical mechanics (CM) with respect to NFLM. A general argument is made that such a disparity may be found commonly for a wide variety of quantum predictions in the classical limit. Alternatives to the Schrodinger equation are considered that might avoid this problem. The meaning of the classical limit is examined. Critical views regarding QM by Schrodinger, Bohm, Bell, Clauser, and others are presented to provide a more complete perspective.
Nonradiating anapole modes in dielectric nanoparticles
NASA Astrophysics Data System (ADS)
Miroshnichenko, Andrey E.; Evlyukhin, Andrey B.; Yu, Ye Feng; Bakker, Reuben M.; Chipouline, Arkadi; Kuznetsov, Arseniy I.; Luk'yanchuk, Boris; Chichkov, Boris N.; Kivshar, Yuri S.
2015-08-01
Nonradiating current configurations attract attention of physicists for many years as possible models of stable atoms. One intriguing example of such a nonradiating source is known as `anapole'. An anapole mode can be viewed as a composition of electric and toroidal dipole moments, resulting in destructive interference of the radiation fields due to similarity of their far-field scattering patterns. Here we demonstrate experimentally that dielectric nanoparticles can exhibit a radiationless anapole mode in visible. We achieve the spectral overlap of the toroidal and electric dipole modes through a geometry tuning, and observe a highly pronounced dip in the far-field scattering accompanied by the specific near-field distribution associated with the anapole mode. The anapole physics provides a unique playground for the study of electromagnetic properties of nontrivial excitations of complex fields, reciprocity violation and Aharonov-Bohm like phenomena at optical frequencies.
Fermion mass generation and induced current in low-dimensional models with nontrivial topology
NASA Astrophysics Data System (ADS)
Zhukovskii, V. Ch.; Stepanov, E. A.
2015-02-01
We study the process of dynamical fermion mass generation in a three-dimensional model with two types of interacting fermions existing in three dimensions and on a two-dimensional brane with the action of the A3 gauge field taken into account. We investigate the model of a nanotube with the dimension ?2 × S1. We establish that in the expression for the fermionic gap, along with the dynamical contribution of the condensate m, the four-fermion interaction results in another kinematic contribution, an Aharonov-Bohm phase calculated from the condition of a minimum of the effective potential of the model. We demonstrate the possibility of induced current generation due to the effect of vacuum polarization with the role played by the nontrivial topology of the problem taken into account.
Experimental Demonstration of a Synthetic Lorentz Force by Using Radiation Pressure
NASA Astrophysics Data System (ADS)
Šanti?, N.; Dub?ek, T.; Aumiler, D.; Buljan, H.; Ban, T.
2015-09-01
Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employing the analogy between the Berry phase and the Aharonov-Bohm phase. Interestingly, radiation pressure - being one of the most common forces induced by light - has not yet been used for synthetic magnetism. We experimentally demonstrate a synthetic Lorentz force, based on the radiation pressure and the Doppler effect, by observing the centre-of-mass motion of a cold atomic cloud. The force is perpendicular to the velocity of the cold atomic cloud, and zero for the cloud at rest. Our novel concept is straightforward to implement in a large volume, for a broad range of velocities, and can be extended to different geometries.
Asymmetric coherent transmission for single particle diode and gyroscope
S. Yang; Z. Song; C. P. Sun
2009-12-02
We study the single particle scattering process in a coherent multi-site system consisting of a tight-binding ring threaded by an Aharonov-Bohm flux and several attaching leads. The asymmetric behavior of scattering matrix is discovered analytically in the framework of both Bethe Ansatz and Green's function formalism. It is found that, under certain conditions, a three-site electronic system can behave analogous to a perfect semiconductor diode where current flows only in one direction. The general result is also valid for a neutral particle system since the effective magnetic flux may be implemented by a globe rotation. This observation means that the three-site system can serve as an orientation measuring gyroscope due to the approximate linear dependence of the current difference of two output leads on the rotational angular velocity.
Is Quantum Mechanics Incompatible with Newton's First Law?
NASA Astrophysics Data System (ADS)
Rabinowitz, Mario
2008-04-01
Quantum mechanics (QM) clearly violates Newton’s First Law of Motion (NFLM) in the quantum domain for one of the simplest problems, yielding an effect in a force-free region much like the Aharonov-Bohm effect. In addition, there is an incompatibility between the predictions of QM in the classical limit, and that of classical mechanics (CM) with respect to NFLM. A general argument is made that such a disparity may be found commonly for a wide variety of quantum predictions in the classical limit. Alternatives to the Schrödinger equation are considered that might avoid this problem. The meaning of the classical limit is examined. Critical views regarding QM by Schrödinger, Bohm, Bell, Clauser, and others are presented to provide a more complete perspective.
Gauge field optics with anisotropic media.
Liu, Fu; Li, Jensen
2015-03-13
By considering gauge transformations on the macroscopic Maxwell's equations, a two-dimensional gauge field, with its pseudomagnetic field in the real space, is identified as tilted anisotropy in the constitutive parameters. We show that the optical spin Hall effect with broadband response and one-way edge states become possible simply by using anisotropic media. The proposed gauge field also allows us to obtain unidirectional propagation for a particular pseudospin based on the Aharonov-Bohm effect. Our approach will be useful in spoof magneto-optics with arbitrary magnetic fields mimicked by metamaterials with subwavelength unit cells. It also serves as a generic way to design polarization-dependent devices. PMID:25815934
Black Holes with Quantum Massive Spin-2 Hair
Gia Dvali
2006-05-31
We show that black holes can posses a long range quantum mechanical hair associated with a massive spin-2 field, which can be detected by a stringy generalization of the Aharovon-Bohm effect, in which a string loop lassoes the black hole. The long distance effect persist for arbitrarily high mass of the spin-2 field. An analogous effect is exhibited by a massive antisymmetric two-form field. We make a close parallel between the two and the ordinary Aharonov-Bohm phenomenon, and also show that in the latter case the effect can be experienced even by the electrically-neutral particles, provided some boundary terms are added to the action.
Black holes with quantum massive spin-2 hair
Dvali, Gia
2006-08-15
We show that black holes can posses a long range quantum-mechanical hair associated with a massive spin-2 field, which can be detected by a stringy generalization of the Aharovon-Bohm effect, in which a string loop lassoes the black hole. The long distance effect persist for arbitrarily high mass of the spin-2 field. An analogous effect is exhibited by a massive antisymmetric two-form field. We make a close parallel between the two and the ordinary Aharonov-Bohm phenomenon, and also show that in the latter case the effect can be experienced even by the electrically-neutral particles, provided some boundary terms are added to the action.
Captulo 4 Recordacoes de Calculo Vetorial em Tres
Barata, JoÃ£o Carlos Alves
â?oes. As identidades aqui listadas sâ?ao â?? uteis em diversas â??areas da Fâ??ï¿½sica, como no Eletromagnetismo e na Mecâ??anica dos Fluidos. Todos os resultados que aqui apresentamos podem ser formulados com mais elegâ??ancia e
Texas Hold 'em Online Poker: A Further Examination
ERIC Educational Resources Information Center
Hopley, Anthony A. B.; Dempsey, Kevin; Nicki, Richard
2012-01-01
Playing Texas Hold 'em Online Poker (THOP) is on the rise. However, there is relatively little research examining factors that contribute to problem gambling in poker players. The aim of this study was to extend the research findings of Hopley and Nicki (2010). The negative mood states of depression, anxiety and stress were found to be linked to…
Automatic Derivation of Statistical Algorithms: The EM Family and Beyond
Automatic Derivation of Statistical Algorithms: The EM Family and Beyond Alexander G. Gray Carnegie- tem which takes a high-level statistical model specification, uses power- ful symbolic techniques- rithms for clustering, regression, and a multinomial form of PCA. 1 Automatic Derivation of Statistical
oklahoma state university emPloyee BeneFits
OSU oklahoma state university emPloyee BeneFits 2015 through it all.® #12;#12;taBle oF Contents value products and unrivaled customer service to more oklahomans than any other health insurance plan and promoting wellness programs that you and your family can conveniently integrate into your daily life
492 BOOK REVIEWS the missing data paradigm, and the EM
Neumaier, Arnold
492 BOOK REVIEWS the missing data paradigm, and the EM algorithm. The book is well organized an annoying habit of omitting articles. The level of the book is that of advanced undergraduate courses for the book: researchers study ing Monte Carlo methods, scientists using Monte Carlo, and graduate students
Guia do calouro 1 2013 UnB EM AO
Ayala-Rincón, Mauricio
Marques de Toledo Camargo Reitor Sônia Nair Báo Vice-reitora Mauro Luiz Rabelo Decanato de Ensino de501962 2012 Guia do calouro 1º 2013 UnB EM AÇÃO Uma janela de oportunidades #12;Expediente Ivan Oliveira Paulino Coordenação executiva da comissão UnB 5o anos e Coordenação da Comunicação Institucional
An EM algorithm for a semiparametric mixture model
Vandekerkhove, Pierre
An EM algorithm for a semiparametric mixture model Laurent Bordes1 Didier Chauveau2 Pierre Marne-la-VallÂ´ee & CNRS January 2006 Abstract. Recently several authors considered finite mixture models not obvious, and when it occurs, inference methods are rather specific to the mixture model under
EMS-generated Rhizoctonia resistance in an adapted wheat
Technology Transfer Automated Retrieval System (TEKTRAN)
We report the first genetic resistance in wheat to Rhizoctonia solani AG-8 and R. oryzae, the causal agents of Rhizoctonia root rot and pre-emergence damping-off. Rhizoctonia resistance was generated in the spring wheat cultivar Scarlet using EMS mutagenesis. Resistant plants, named Scarlet-Rz1, d...
DYNAMICAL LEARNING WITH THE EM ALGORITHM FOR NEURAL NETWORKS
Freitas, Nando de
the tracking of multiple targets. The method of learning and inference in linear state space models via the EM in batches, it is possible to address the general problem of Bayesian learning with Gaussian approximations multiple indicators and multiple causes of a single latent variable. Chen's MIMIC model was implemented
7 CFR 1945.20 - Making EM loans available.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 13 2011-01-01 2009-01-01 true Making EM loans available. 1945.20 Section 1945.20 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS...
A Science Service Feature 1 WHYTHE"EmHER ?
A Science Service Feature 1 WHYTHE"EmHER ? Dr. Charles F. Erooks, Secretary, American the plain white f l a g has a dark trh@&aLr f l a g above i t the prophesy is fair and warmer by Science Service Science Service, 1115 Conn. Ave., Washington, D .C . #12;
Reversing Climate Change: Using Carbon Tech to Fight Carbon Em
Reversing Climate Change: Using Carbon Tech to Fight Carbon Em Frank H. Shu1 & HX Team (formed 2009 for coal replacement (carbon neutral) · 400 oC: biochar as soil amendment (carbon negative) · Acetate-carbonate/acetone-acetic acid cycle for transp fuel: 3 acetone + heat & zeolite à mesitylene (C9H12) + 3H2O · Syngas: CO, H2
Detecting Particles in Cryo-EM Micrographs using Learned Features
Kriegman, David J.
Detecting Particles in Cryo-EM Micrographs using Learned Features Satya P. Mallick1 Yuanxin Zhu2 learning-based approach is presented for particle detection in cryo-electron micro- graphs using of the particle's appearance using a set of training examples of the particles and a set of images that do
Signs and Guides: Wayfinding Alternatives for the EMS Library.
ERIC Educational Resources Information Center
Johnson, Johanna H.
Concerned with increasing the accessibility of the collection of the Engineering/Math Sciences (EMS) Library at the University of California at Los Angeles through the use of self guidance systems, this practical study focused on the problem context, general library guides, and library signage in reviewing the literature, and conducted a survey of…
Optical Spectroscopy of Single-Walled Carbon Nanotubes Under Extreme Conditions
NASA Astrophysics Data System (ADS)
Searles, Thomas A., Jr.
Single-walled carbon nanotubes (SWNTs) are one of the leading candidate materials to realize novel nanoscale photonic devices. In order to assess their performance characteristics as optoelectronic materials, it is crucial to examine their optical properties in highly non-equilibrium situations such as high magnetic fields, low temperatures, and under high photoexcitation. Therefore, we present our latest result on the magnetic susceptibility anisotropy of metallic carbon nanotubes due to the Aharonov-Bohm effect. Here, we performed magnetic linear dichroism on a metallic-enriched HiPco SWNT sample utilizing a 35 T Hybrid Magnet to measure absorption with light polarization both perpendicular and parallel to the magnetic field. By relating these values with the nematic order parameter for alignment, we found that the metallic carbon nanotubes do not follow a strict diameter dependence across the 7 chiralities present in our sample. In addition to the studying the absorption properties exhibited at high magnetic field, we performed temperature-dependent (300 K to 11 K) photoluminescence (PL) on HiPco SWNTs embedded in an iota-carrageenan matrix utilizing intense fs pulses from a wavelength-tunable optical parametric amplifier. We found that for each temperature the PL intensity saturates as a function of pump fluence and the saturation intensity increases from 300 K to a moderate temperature around 100-150 K. Within the framework of diffusion-limited exciton-exciton annihilation (EEA), we successfully estimated the density of 1D excitons in SWNTs as a function of temperature and chirality. These results coupled with our results of magnetic brightening, or an increase in PL intensity as a function of magnetic flux through each SWNT due to the Aharonov-Bohm effect, yield great promise that in the presence of a high magnetic field the density of excitons can be further increased.
Phase diagram of the Bose-Hubbard model with T{sub 3} symmetry
Rizzi, Matteo; Fazio, Rosario; Cataudella, Vittorio
2006-04-01
We study the quantum phase transition between the insulating and the globally coherent superfluid phases in the Bose-Hubbard model with T{sub 3} structure, the 'dice lattice'. Even in the absence of any frustration the superfluid phase is characterized by modulation of the order parameter on the different sublattices of the T{sub 3} structure. The zero-temperature critical point as a function of magnetic field shows the characteristic 'butterfly' form. At full frustration the superfluid region is strongly suppressed. In addition, due to the existence of the Aharonov-Bohm cages at f=1/2, we find some evidence for the existence of an intermediate insulating phase characterized by a zero superfluid stiffness but finite compressibility. In this intermediate phase bosons are localized due to the external frustration and the topology of the T{sub 3} lattice. We name this new phase the Aharonov-Bohm insulator. In the presence of charge frustration the phase diagram acquires the typical lobe structure. The form and hierarchy of the Mott insulating states with fractional fillings are dictated by the particular topology of the T{sub 3} lattice. The results presented were obtained by a variety of analytical methods: mean-field and variational techniques to approach the phase boundary from the superconducting side and a strongly coupled expansion appropriate for the Mott insulating region. In addition we performed quantum Monte Carlo simulations of the corresponding (2+1)-dimensional XY model to corroborate the analytical calculations with a more accurate quantitative analysis. We finally discuss experimental realization of the T{sub 3} lattice both with optical lattices and with Josephson junction arrays.
Dabartini? Žem?s Plutos Judesi? Lietuvos Paj?rio Teritorijoje S?sajos Su Nuos?din?s Dangos Savyb?mis
NASA Astrophysics Data System (ADS)
Zakarevi?ius, Algimantas; Puzien?, R?ta
2008-03-01
Koreliacin?s ir regresin?s analiz?s metodais išnagrin?ta išmatuot?j? dabartini? vertikali?j? Žem?s plutos judesi? bei nuos?din?s dangos savybi? s?sajos. Taikant atvirkštin?s žingsnin?s regresijos analiz? išskirti reikšmingiausieji tiriam? gamtini? proces? rodikliai. Atliktas koreliacin?s analiz?s koeficient? priklausomyb?s bendrai koreliacinei erdvei tyrimas. Sudaryti bei su esamais palyginti regresin?s analiz?s metodu prognozuojam? vertikali?j? Žem?s paviršiaus judesi? modeliai.
Neirotti, Juan Pablo
Approved Module Information for EM4003, 2014/5 Module Title/Name: Project Management Module Code. BEng/MEng Chemical Engineering. MSc Photonic Networks Engineering (MAPNET). MSc IT Project Management Information Module Aims: To explore the theory of project management and its application to real life
Rebollo-Neira, Laura
Module Information for EM4003, 2015/6 - APPROVED Module Title/Name: Project Management Module Code Engineering (MAPNET). MSc IT Project Management. MSc Mechanical Engineering (Modelling). Contributing School: None Specified Module Learning Information Module Aims: To explore the theory of project management
Neirotti, Juan Pablo
Approved Module Information for EM4002, 2014/5 Module Title/Name: Strategic Management Module Code: The purpose of this module is to introduce students to the concepts and techniques of strategic management: * demonstrate their understanding of key terms and concepts of strategic management * undertake strategic
Neirotti, Juan Pablo
Approved Module Information for EM4012, 2014/5 Module Title/Name: Human Resource Management Module and Understanding Understanding of the way a Human Resource Function is designed and managed and its relationship of human resources management. Tutorials and class discussions will enable students to explore the various
Composting of rice straw with effective microorganisms (EM) and its influence on compost quality
2013-01-01
This study aims to assess the effect of EM application on the composting process of rice straw with goat manure and green waste and to evaluate the quality of both compost treatments. There are two treatment piles in this study, in which one pile was applied with EM and another pile without EM. Each treatment was replicated three times with 90 days of composting duration. The parameters for the temperature, pH, TOC and C/N ratio, show that decomposition of organic matter occurs during the 90-day period. The t-test conducted shows that there is a significant difference between compost with EM and compost without EM. The application of EM in compost increases the macro and micronutrient content. The following parameters support this conclusion: compost applied with EM has more N, P and K content (P?EM. Although the Fe in compost with EM is much higher (P?EM, for Zn and Cu, there is no significant difference between treatments. This study suggests that the application of EM is suitable to increase the mineralization in the composting process. The final resultant compost indicated that it was in the range of the matured level and can be used without any restriction. PMID:23390930
The threshold EM algorithm for parameter learning in bayesian network with incomplete data
Lamine, Fradj Ben; Mahjoub, Mohamed Ali
2012-01-01
Bayesian networks (BN) are used in a big range of applications but they have one issue concerning parameter learning. In real application, training data are always incomplete or some nodes are hidden. To deal with this problem many learning parameter algorithms are suggested foreground EM, Gibbs sampling and RBE algorithms. In order to limit the search space and escape from local maxima produced by executing EM algorithm, this paper presents a learning parameter algorithm that is a fusion of EM and RBE algorithms. This algorithm incorporates the range of a parameter into the EM algorithm. This range is calculated by the first step of RBE algorithm allowing a regularization of each parameter in bayesian network after the maximization step of the EM algorithm. The threshold EM algorithm is applied in brain tumor diagnosis and show some advantages and disadvantages over the EM algorithm.
Maier, Rudolf Richard
, Programa de Pós Graduação em Biologia Molecular 1 EDITAL Nº 01/2015 SELEÇÃO DE CANDIDATOS ÀS VAGAS DO PROGRAMA DE PÓS-GRADUAÇÃO EM BIOLOGIA MOLECULAR PARA OS CURSOS DE MESTRADO ACADÊMICO E DOUTORADO PARA O-Graduação em Biologia Molecular, em conformidade com as exigências do Regulamento deste programa e da Resolução
Sanjay M. Wagh
2004-09-12
In non-relativistic as well as in special relativistic quantum theory, {\\em mass} and {\\em charge} are {\\em pure numbers} appearing in various (quantum) operators and admit {\\em any values}, {\\it ie}, values for these quantities are to be prescribed {\\em by hand}. This is, in a theory of probability, understandable since we need to {\\em assume} some {\\em intrinsic} properties of the object we are calculating the probability about. Then, if we {\\em specify}, in some satisfactory manner, mass and charge for a point of the space in a suitable general-relativistic framework, the quantum theoretical framework could, in principle, be {\\em obtainable} within it. Heuristic arguments are presented to show that a {\\em natural unification} of the quantum theory and the general theory of relativity is achievable in this manner.
Image segmentation by adaptive distance based on EM algorithm
Mahjoub, Mohamed Ali
2012-01-01
This paper introduces a Bayesian image segmentation algorithm based on finite mixtures. An EM algorithm is developed to estimate parameters of the Gaussian mixtures. The finite mixture is a flexible and powerful probabilistic modeling tool. It can be used to provide a model-based clustering in the field of pattern recognition. However, the application of finite mixtures to image segmentation presents some difficulties; especially it's sensible to noise. In this paper we propose a variant of this method which aims to resolve this problem. Our approach proceeds by the characterization of pixels by two features: the first one describes the intrinsic properties of the pixel and the second characterizes the neighborhood of pixel. Then the classification is made on the base on adaptive distance which privileges the one or the other features according to the spatial position of the pixel in the image. The obtained results have shown a significant improvement of our approach compared to the standard version of EM alg...
Magen David Adom--the EMS in Israel.
Ellis, Daniel Y; Sorene, Eliot
2008-01-01
Israel is a small country with a population of around 7 million. The sole EMS provider for Israel is Magen David Adom (MDA) (translated as 'Red Shield of David'). MDA also carries out the functions of a National Society (similar to the Red Cross) and provides all the blood and blood product services for the country. Nationwide, the organisation responds to over 1000 emergency calls a day and uses doctors, paramedics, emergency medical technicians and volunteers. Local geopolitics has meant that MDA has to be prepared for anything from everyday emergency calls to suicide bombings and regional wars. MDA also prides itself in being able to rapidly assemble and dispatch mobile aid teams to scenes of international disasters. Such a broad range of activities is unusual for a single EMS organisation. PMID:17767990
Superconducting Electromagnetic Suspension (EMS) system for Grumman Maglev concept
NASA Technical Reports Server (NTRS)
Kalsi, Swarn S.
1994-01-01
The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low vehicle speeds; low magnetic field at the SC coil--less than 0.35 T; no need to use non-magnetic/non-metallic rebar in the guideway structure; low magnetic field in passenger cabin--approximately 1 G; low forces on the SC coil; employs state-of-the-art NbTi wire; no need for an active magnet quench protection system; and lower weight than a magnet system with copper coils. The EMS Maglev described in this paper does not require development of any new technologies. The system could be built with the existing SC magnet technology.
Neirotti, Juan Pablo
in an engineering business - Organisational understanding #12;- Communication and team building - LeadershipApproved Module Information for EM4023, 2014/5 Module Title/Name: Management in Engineering Enterprises Module Code: EM4023 School: Engineering and Applied Science Module Type: Standard Module New
EMS mutagenesis in the pea aphid Acyrthosiphon pisum.
Tagu, Denis; Le Trionnaire, Gaël; Tanguy, Sylvie; Gauthier, Jean-Pierre; Huynh, Jean-René
2014-04-01
In aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. Such phenotypic plasticity cannot be studied with classical genetic model organisms such as Caenorhabditis elegans or Drosophila melanogaster. The genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. Here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (EMS), to generate random mutations within the Acyrthosiphon pisum genome. We found that even low concentrations of EMS were toxic for two genotypes of A. pisum. Mutagenesis efficiency was nevertheless assessed by estimating the occurrence of mutational events on the X chromosome. Indeed, any lethal mutation on the X-chromosome would kill males that are haploid on the X so that we used the proportion of males as an estimation of mutagenesis efficacy. We could assess a putative mutation rate of 0.4 per X-chromosome at 10 mM of EMS. We then applied this protocol to perform a small-scale mutagenesis on parthenogenetic individuals, which were screened for defects in their ability to produce sexual individuals in response to photoperiod shortening. We found one mutant line showing a reproducible altered photoperiodic response with a reduced production of males and the appearance of aberrant winged males (wing atrophy, alteration of legs morphology). This mutation appeared to be stable because it could be transmitted over several generations of parthenogenetic individuals. To our knowledge, this study represents the first example of an EMS-generated aphid mutant. PMID:24531730
Improving EM&V for Energy Efficiency Programs (Fact Sheet)
Not Available
2012-07-01
This fact sheet describes the objectives of the U.S. Department of Energy Uniform Methods Project to bring consistency to energy savings calculations in U.S. energy efficiency programs. The U.S. Department of Energy (DOE) is developing a framework and a set of protocols for determining gross energy savings from energy efficiency measures and programs. The protocols represent a refinement of the body of knowledge supporting energy efficiency evaluation, measurement, and verification (EM&V) activities. They have been written by technical experts within the field and reviewed by industry experts. Current EM&V practice allows for multiple methods for calculating energy savings. These methods were developed to meet the needs of energy efficiency program administrators and regulators. Although they served their original objectives well, they have resulted in inconsistent and incomparable savings results - even for identical measures. The goal of the Uniform Methods Project is to strengthen the credibility of energy savings determinations by improving EM&V, increasing the consistency and transparency of how energy savings are determined.
Integrated GW-EM Follow-up Analysis
NASA Astrophysics Data System (ADS)
Ackley, Kendall; Eikenberry, Stephen; Klimenko, Sergey; LSC Collaboration
2015-04-01
Advanced Gravitational-Wave (GW) detectors such as Advanced LIGO and Advanced Virgo are expected to become operational for observation runs in 2015, with an expected ultimate improvement in sensitivity over previous configurations by a factor of 10 by 2019. There are many potential electromagnetic (EM) counterparts to GWs including short and long gamma-ray bursts (GRBs) and kilonovae. While SGRBs and LGRBs predominantly emit in the X-ray, and the recently-observed kilonova primarily in the infrared, all three sources are expected to have detectable traces in the optical band, albeit requiring very sensitive optical telescopes. In order to aid in the optimization of GW trigger follow-up procedures, we perform an end-to-end analysis feasibility study using synthesized Advanced detector data simulating a GW detection with a theoretical EM counterpart injected into archival optical images. We use images from Robotic Optical Transient Search Experiment (ROTSE) and Palomar Transient Factory (PTF), and inject candidate events following observed lightcurves of SGRBs, LGRBs, and kilonovae. The use of Zernike PSF decomposition on candidate objects offers a fast way to identify point sources, speeding up the automated identification of transient sources in the images. We present our method of transient recovery and the latest results of our feasibility study of a joint GW-EM observation.
Gaussian mean-shift is an EM algorithm.
Carreira-Perpiñán, Miguel A
2007-05-01
The mean-shift algorithm, based on ideas proposed by Fukunaga and Hostetler [16], is a hill-climbing algorithm on the density defined by a finite mixture or a kernel density estimate. Mean-shift can be used as a nonparametric clustering method and has attracted recent attention in computer vision applications such as image segmentation or tracking. We show that, when the kernel is Gaussian, mean-shift is an expectation-maximization (EM) algorithm and, when the kernel is non-Gaussian, mean-shift is a generalized EM algorithm. This implies that mean-shift converges from almost any starting point and that, in general, its convergence is of linear order. For Gaussian mean-shift, we show: 1) the rate of linear convergence approaches 0 (superlinear convergence) for very narrow or very wide kernels, but is often close to 1 (thus, extremely slow) for intermediate widths and exactly 1 (sublinear convergence) for widths at which modes merge, 2) the iterates approach the mode along the local principal component of the data points from the inside of the convex hull of the data points, and 3) the convergence domains are nonconvex and can be disconnected and show fractal behavior. We suggest ways of accelerating mean-shift based on the EM interpretation. PMID:17356198
EMS-Vision: combining on- and off-road driving
NASA Astrophysics Data System (ADS)
Gregor, Rudolf; Luetzeler, Michael; Dickmanns, Ernst D.
2001-09-01
In the past, work at the Universitat der Bundeswehr Muenchen (UBM) has been focused on autonomous road vehicles. During the last four years the Expectation-based Multi-focal Saccadic Vision (EMS-Vision) system has been developed and implemented. EMS-Vision is the 3rd generation dynamic vision system following the 4-D approach. The explicit representation of the own capabilities combined with a complex control and information flow allows the implementation of decision units for goal oriented activation of locomotion and perception. Due to this general approach and in contrast to former UBM systems that were specially designed and optimized for certain limited scenarios and domains, e.g., road following on Autobahnen, the EMS-Vision system can handle complex driving missions spanning multiple domains. It has been realized on a decentralized parallel hardware structure, exclusively built of commercial off-the-shelf components, in both UBM test vehicles VaMoRs and VaMP. Results from an autonomously performed mission on the UBM campus are discussed.
Novaes, Maria Rita Carvalho Garbi; Novaes, Luiz Carlos Garcez; Guilhem, Dirce; Lolas, Fernando; Silveira, Carla; Guiotti, Murilo
2009-01-01
Objetivo Realizar uma análise da inserção da ética e humanidades no currículo do Curso de Medicina da Escola Superior em Ciências da Saúde - ESCS, escola pública do Distrito Federal, Brasil, de forma a contribuir com o processo de gestão curricular. Metodologia O Estudo é de coorte e documental. Foram pesquisados 37 termos relacionados à ética e 36 referentes à humanização nos objetivos educacionais e conteúdo dos módulos temáticos, habilidades e atitudes e interação ensino-serviço-comunidade, de 1a a 4a série e no programa do internato no currículo (ano 2006) e no projeto pedagógico do Curso de Medicina (2001). Resultados Maior inserção da humanização, ética e bioética na 1a e 2a série, quando comparado à inserção na 3a e 4a série e no internato, (IC95%-?=0,034, pvalue=0,007). Unidade de habilidades e atitudes: freqüência das 3 temáticas no currículo da 1a a 4a séries (IC95%-?=0,026, pvalue=0,013). Quando comparada a inserção entre o internato e as quatro primeiras séries, observa-se que nestas a inserção da temática humanização é superior (IC95%-?=0,042, pvalue=0,029). Conclusão O currículo desenvolvido no ano de 2006 na ESCS apresentou correlação com o projeto pedagógico do curso e contemplou a temática de forma abrangente, em todas as séries e internato. PMID:20396594
Yang, Yang; Longini, Ira M; Halloran, M Elizabeth; Obenchain, Valerie
2012-12-01
In epidemics of infectious diseases such as influenza, an individual may have one of four possible final states: prior immune, escaped from infection, infected with symptoms, and infected asymptomatically. The exact state is often not observed. In addition, the unobserved transmission times of asymptomatic infections further complicate analysis. Under the assumption of missing at random, data-augmentation techniques can be used to integrate out such uncertainties. We adapt an importance-sampling-based Monte Carlo Expectation-Maximization (MCEM) algorithm to the setting of an infectious disease transmitted in close contact groups. Assuming the independence between close contact groups, we propose a hybrid EM-MCEM algorithm that applies the MCEM or the traditional EM algorithms to each close contact group depending on the dimension of missing data in that group, and discuss the variance estimation for this practice. In addition, we propose a bootstrap approach to assess the total Monte Carlo error and factor that error into the variance estimation. The proposed methods are evaluated using simulation studies. We use the hybrid EM-MCEM algorithm to analyze two influenza epidemics in the late 1970s to assess the effects of age and preseason antibody levels on the transmissibility and pathogenicity of the viruses. PMID:22506893
Departamento de Geografia e Meio Ambiente Coordenao de Ps-Graduao em Geografia
DÃaz, Lorenzo J.
Departamento de Geografia e Meio Ambiente CoordenaÃ§Ã£o de PÃ³s-GraduaÃ§Ã£o em Geografia Rua MarquÃªs de UNIVERSIDADE CATÃ?LICA DO RIO DE JANEIRO DEPARTAMENTO DE GEOGRAFIA E MEIO AMBIENTE PROGRAMA DE PÃ?S-GRADUAÃ?Ã?O EM GEOGRAFIA CURSO DE DOUTORADO EM GEOGRAFIA E D I T A L Â 2015.2 O Departamento de Geografia e Meio Ambiente
MTODOS MULTIGRID PARA A SIMULAO POR ELEMENTOS FINITOS DE ESCOAMENTOS IMISCVEIS EM
Coutinho, Alvaro L. G. A.
1 MÃ?TODOS MULTIGRID PARA A SIMULAÃ?Ã?O POR ELEMENTOS FINITOS DE ESCOAMENTOS IMISCÃVEIS EM MEIOS pressÃ£o em escoamentos de fluidos imiscÃveis em meios porosos. A equaÃ§Ã£o da saturaÃ§Ã£o Ã© aproximada; Meios Porosos. #12; 2 1. INTRODUÃ?Ã?O Nos Ãºltimos anos os mÃ©todos multigrid tem sido largamente estudados
Modeling of MHD edge containment in strip casting with ELEKTRA and CaPS-EM codes
Chang, F. C.
2000-01-12
This paper presents modeling studies of magnetohydrodynamics analysis in twin-roll casting. Argonne National Laboratory (ANL) and ISPAT Inland Inc. (Inland), formerly Inland Steel Co., have worked together to develop a three-dimensional (3-D) computer model that can predict eddy currents, fluid flows, and liquid metal containment of an electromagnetic (EM) edge containment device. The model was verified by comparing predictions with experimental results of liquid metal containment and fluid flow in EM edge dams (EMDs) that were designed at Inland for twin-roll casting. This mathematical model can significantly shorten casting research on the use of EM fields for liquid metal containment and control. The model can optimize the EMD design so it is suitable for application, and minimize expensive time-consuming full-scale testing. Numerical simulation was performed by coupling a 3-D finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA can predict the eddy-current distribution and the EM forces in complex geometries. CaPS-EM can model fluid flows with free surfaces. The computed 3-D magnetic fields and induced eddy currents in ELEKTRA are used as input to temperature- and flow-field computations in CaPS-EM. Results of the numerical simulation compared well with measurements obtained from both static and dynamic tests.
EM-21 Retrieval Knowledge Center: Waste Retrieval Challenges
Fellinger, Andrew P.; Rinker, Michael W.; Berglin, Eric J.; Minichan, Richard L.; Poirier, Micheal R.; Gauglitz, Phillip A.; Martin, Bruce A.; Hatchell, Brian K.; Saldivar, Eloy; Mullen, O Dennis; Chapman, Noel F.; Wells, Beric E.; Gibbons, Peter W.
2009-04-10
EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energy’s (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge and expertise that will be used to address retrieval challenges across the DOE complex. The RKC is also designed to facilitate information sharing across the DOE Waste Site Complex through workshops, and a searchable database of waste retrieval technology information. The database may be used to research effective technology approaches for specific retrieval tasks and to take advantage of the lessons learned from previous operations. It is also expected to be effective for remaining current with state-of-the-art of retrieval technologies and ongoing development within the DOE Complex. To encourage collaboration of DOE sites with waste retrieval issues, the RKC team is co-led by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL). Two RKC workshops were held in the Fall of 2008. The purpose of these workshops was to define top level waste retrieval functional areas, exchange lessons learned, and develop a path forward to support a strategic business plan focused on technology needs for retrieval. The primary participants involved in these workshops included retrieval personnel and laboratory staff that are associated with Hanford and Savannah River Sites since the majority of remaining DOE waste tanks are located at these sites. This report summarizes and documents the results of the initial RKC workshops. Technology challenges identified from these workshops and presented here are expected to be a key component to defining future RKC-directed tasks designed to facilitate tank waste retrieval solutions.
Covariance Matrix Estimation for the Cryo-EM Heterogeneity Problem*
Katsevich, E.; Katsevich, A.; Singer, A.
2015-01-01
In cryo-electron microscopy (cryo-EM), a microscope generates a top view of a sample of randomly oriented copies of a molecule. The problem of single particle reconstruction (SPR) from cryo-EM is to use the resulting set of noisy two-dimensional projection images taken at unknown directions to reconstruct the three-dimensional (3D) structure of the molecule. In some situations, the molecule under examination exhibits structural variability, which poses a fundamental challenge in SPR. The heterogeneity problem is the task of mapping the space of conformational states of a molecule. It has been previously suggested that the leading eigenvectors of the covariance matrix of the 3D molecules can be used to solve the heterogeneity problem. Estimating the covariance matrix is challenging, since only projections of the molecules are observed, but not the molecules themselves. In this paper, we formulate a general problem of covariance estimation from noisy projections of samples. This problem has intimate connections with matrix completion problems and high-dimensional principal component analysis. We propose an estimator and prove its consistency. When there are finitely many heterogeneity classes, the spectrum of the estimated covariance matrix reveals the number of classes. The estimator can be found as the solution to a certain linear system. In the cryo-EM case, the linear operator to be inverted, which we term the projection covariance transform, is an important object in covariance estimation for tomographic problems involving structural variation. Inverting it involves applying a filter akin to the ramp filter in tomography. We design a basis in which this linear operator is sparse and thus can be tractably inverted despite its large size. We demonstrate via numerical experiments on synthetic datasets the robustness of our algorithm to high levels of noise. PMID:25699132
State of the Art in EM Field Computation
Ng, C.; Akcelik, V.; Candel, A.; Chen, S.; Folwell, N.; Ge, L.; Guetz, A.; Jiang, H.; Kabel, A.; Lee, L.-Q.; Li, Z.; Prudencio, E.; Schussman, G.; Uplenchwar, R.; Xiao, L.; Ko, K.; /SLAC
2006-09-25
This paper presents the advances in electromagnetic (EM) field computation that have been enabled by the US DOE SciDAC Accelerator Science and Technology project which supports the development and application of a suite of electromagnetic codes based on the higher-order finite element method. Implemented on distributed memory supercomputers, this state of the art simulation capability has produced results which are of great interest to accelerator designers and with realism previously not possible with standard codes. Examples from work on the International Linear Collider (ILC) project are described.
EM-wave absorption properties of hollow spiral iron particles
NASA Astrophysics Data System (ADS)
Zhang, Wenqiang; Zhang, Deyuan
2015-12-01
Hollow iron spiral particles were fabricated successfully by thermal decomposition method, and they were heat-treated at different temperatures in N2 atmosphere. The electromagnetic wave absorption properties of hollow iron spiral particles were investigated ranging between 1 GHz and 18 GHz. The results indicated that the phase structures of the particles changed from amorphous to nanocrystal with the treating temperature rising, also causing the significant change in electromagnetic parameters and the reflection loss. The reflection loss could reach -33 dB at 16.2 GHz, indicating that the hollow iron spiral particles had the potential to be used in prepare the a high property EM-wave absorber.
Theme park EMS. It's no Mickey Mouse operation.
Philips, J H
1995-07-01
In a single shift, they can rescue someone trapped in a time warp, perform CPR while menacing monsters look over their shoulders or calmly watch as a motorboat chase ends in a huge ball of fire. It's just another routine day for EMS providers in America's theme parks, where getting ready for unusual calls is the norm. JEMS went behind the scenes with theme park responders to explore the unique challenges of their service environment. What we found was a group of super-dedicated professionals who place genuine hospitality right alongside quality patient care. PMID:10143711
Effects of caffeine or EDTA post-treatment on EMS mutagenesis in soybean.
Zhu, B; Gu, A; Deng, X; Geng, Y; Lu, Z
1995-04-01
Seeds of soybean cultivar LD4 were mutagenically treated with EMS (0.3, 0.5, 0.6, 0.9, 1.5 and 1.8%) for 3 h only or plus caffeine (50 mM) or EDTA (1 mM) post-treatment for 5 h. The experimental results indicated that: (1) of the different concentrations of EMS treatment, the M2 mutation frequency induced with 0.6% EMS was the highest (9.7%). When the EMS concentration was over 0.9%, the mutation frequency decreased rapidly. (2) Of the EMS treatments plus caffeine or EDTA post-treatment, the mutagenic effect of 0.6% EMS was the best for inducing morphological variations. Caffeine post-treatment decreased notably the mutation frequency of EMS treatment; when concentrations of EMS were very high (1.5% and 1.8%), mutation frequencies of EDTA post-treatment were still 5.0% and 4.88%, but no mutants were found in EMS treatment or plus caffeine post-treatment. (3) In the M2 mutation spectrum, 11 kinds of mutant types were observed in EMS treatment or plus caffeine or EDTA post-treatment. Relative frequencies of some mutant types (growth period, plant height, grain size, leaf shape and sterility, etc.) were similar among the three treatments, but EDTA post-treatment could change the relative frequencies of yield characteristics (number of pods and grains, grain weight/plant) induced by EMS treatment only. PMID:7885367
Adaptac~ao ao Contexto em Sistemas de Comunicac~ao Heterogeneos
Rodrigues, LuÃs E.T.
. Considerem-se por exemplo aplicacÂ¸ ~oes cooperativas multi-utilizador tais como os jogos em rede ou aplicacÂ¸~oes cooperativas multi-utilizador (tais como os jogos on-line). Embora a maioria das concretizacÂ¸~oes actuais destes jogos se baseiem em arquitecturas cliente-servidor, foram jÂ´a de- Este trabalho foi
LETTER Communicated by Chris Williams Asymptotic Convergence Rate of the EM Algorithm for
Xu, Lei
Massachusetts Institute of Technology #12;2882 Jinwen Ma, Lei Xu, & Michael I. Jordan the rate of convergenceLETTER Communicated by Chris Williams Asymptotic Convergence Rate of the EM Algorithm for Gaussian that the convergence rate of the expectation-maximization (EM) algorithm can be faster than those of convention rst
Neural Computation, 8, 129--151, 1996. On Convergence Properties of the EM Algorithm for
Jordan, Michael I.
Neural Computation, 8, 129--151, 1996. On Convergence Properties of the EM Algorithm for Gaussian Department of Brain and Cognitive Sciences Massachusetts Institute of Technology Abstract We build up. We then analyze the convergence of EM in terms of special properties of P and provide new results
NASA Astrophysics Data System (ADS)
Nafis, Christopher; Jensen, Vern; von Jako, Ron
2008-03-01
Electromagnetic (EM) tracking systems have been successfully used for Surgical Navigation in ENT, cranial, and spine applications for several years. Catheter sized micro EM sensors have also been used in tightly controlled cardiac mapping and pulmonary applications. EM systems have the benefit over optical navigation systems of not requiring a line-of-sight between devices. Ferrous metals or conductive materials that are transient within the EM working volume may impact tracking performance. Effective methods for detecting and reporting EM field distortions are generally well known. Distortion compensation can be achieved for objects that have a static spatial relationship to a tracking sensor. New commercially available micro EM tracking systems offer opportunities for expanded image-guided navigation procedures. It is important to know and understand how well these systems perform with different surgical tables and ancillary equipment. By their design and intended use, micro EM sensors will be located at the distal tip of tracked devices and therefore be in closer proximity to the tables. Our goal was to define a simple and portable process that could be used to estimate the EM tracker accuracy, and to vet a large number of popular general surgery and imaging tables that are used in the United States and abroad.
EM Attack Is Non-Invasive? -Design Methodology and Validity Verification
International Association for Cryptologic Research (IACR)
EM Attack Is Non-Invasive? - Design Methodology and Validity Verification of EM Attack Sensor. This paper presents a standard-cell-based semi-automatic design methodology of a new conceptual a cryptographic LSI caused by a mi- cro probe brought near the LSI. A dual-coil sensor architecture with an LUT-programming
EmSe: Supporting Children's Information Finding Needs within a Hospital Environment
Azzopardi, Leif
de Vries PuppyIR http://www.puppyir.eu Introduction For children, illness and other medical, and to outpatients via the web. The EmSe service EmSe is built using the PuppyIR Framework [3], which provides the following services are built: 1 http://www.emmakids.nl/ #12;1. The Body Browser enables exploration
Schiller, Steven R.; Goldman, Charles A.
2011-06-24
Evaluating the impacts and effectiveness of energy efficiency programs is likely to become increasingly important for state policymakers and program administrators given legislative mandates and regulatory goals and increasing reliance on energy efficiency as a resource. In this paper, we summarize three activities that the authors have conducted that highlight the expanded role of evaluation, measurement and verification (EM&V): a study that identified and analyzed challenges in improving and scaling up EM&V activities; a scoping study that identified issues involved in developing a national efficiency EM&V standard; and lessons learned from providing technical assistance on EM&V issues to states that are ramping up energy efficiency programs. The lessons learned are summarized in 13 EM&V issues that policy makers should address in each jurisdiction and which are listed and briefly described. The paper also discusses how improving the effectiveness and reliability of EM&V will require additional capacity building, better access to existing EM&V resources, new methods to address emerging issues and technologies, and perhaps foundational documents and approaches to improving the credibility and cross jurisdictional comparability of efficiency investments. Two of the potential foundational documents discussed are a national EM&V standard or resource guide and regional deemed savings and algorithm databases.
Initial value approach to the EM induction in a heterogeneous sphere: Validation of the method
Cerveny, Vlastislav
of electromagnetic induction is reformulated in the weak sense. The magnetic #12;eld is parameterized by vectorInitial value approach to the EM induction in a heterogeneous sphere: Validation of the method J, Czech Republic. Abstract. A newly developed initial-value formulation of the EM induction problem
Estudo revela que dunas da cratera de Gale em Marte esto ativas Autor: Catarina Solano
Instituto de Sistemas e Robotica
Estudo revela que dunas da cratera de Gale em Marte estão ativas Autor: Catarina Solano Data de liderada pelo instituto norte-americano SETI concluiu que as dunas da cratera de Gale, no planeta Marte transporte de sedimentos em Marte", sublinha David Vaz, que também é investigador no Centro de Recursos
UNIVERSIDADE FEDERAL DE SANTA CATARINA -CENTRO DE DESPORTOS PROGRAMA DE PS-GRADUAO EM EDUCAO FSICA
Hanazaki, Natalia
UNIVERSIDADE FEDERAL DE SANTA CATARINA - CENTRO DE DESPORTOS PROGRAMA DE PÓS-GRADUAÇÃO EM EDUCAÇÃO/D Kelly Samara da Silva / Tânia Rosane Bertoldo Benedetti / Maria Alice DEF 3105-001 Cineantropometria 04 Dantas de Lucas **DEF 510005 Estudos Avançados em Atividade Física Relacionada à Saúde 03 D Maria Alice
REGIMENTO DO CURSO DE PS-GRADUAO EM COMPUTAO APLICADA TTULO I DOS OBJETIVOS E FINALIDADES
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM COMPUTAÇÃO APLICADA TÍTULO I DOS OBJETIVOS E FINALIDADES Art. 1º O Curso de pós-graduação em Computação Aplicada, doravante referido como Curso, mantém GERAL Art. 2º O Curso reger-se-á pelo Regimento dos Cursos de Pós-Graduação do INPE, por este
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PS-GRADUAO EM AGROECOSSISTEMAS
Floeter, Sergio Ricardo
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PÓS-GRADUAÇÃO EM AGROECOSSISTEMAS EDITAL 004/MPA-CCA/2015 MESTRADO PROFISSIONAL EM AGROECOSSISTEMAS O coordenador do curso de Pós-Graduação Mestrado dos candidatos pela Comissão avaliadora e aprovação pelo Colegiado do Curso. 13 de novembro de 2015
REGIMENTO DO CURSO DE PS-GRADUAO EM COMPUTAO APLICADA TTULO I -DOS OBJETIVOS E FINALIDADES
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM COMPUTAÇÃO APLICADA TÍTULO I - DOS OBJETIVOS E FINALIDADES Art 1º - O Curso de pós-graduação em Computação Aplicada, doravante referido como Curso, mantém GERAL Art. 2º - O Curso reger-se-á pelo Regimento dos Cursos de Pós-Graduação do INPE, por este
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PS-GRADUAO EM AGROECOSSISTEMAS
Floeter, Sergio Ricardo
UNIVERSIDADE FEDERAL DE SANTA CATARINA CURSO DE PÓS-GRADUAÇÃO EM AGROECOSSISTEMAS MESTRADO selecionados: mp.ppga@contato.ufsc.br Informamos que a não confirmação da intenção de frequentar o curso Coordenador do Curso de Mestrado Profissional em Agroecossistemas - UFSC #12;
REGIMENTO DO CURSO DE PS-GRADUAO EM CINCIA E TECNOLOGIA DE MATERIAIS E SENSORES
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM CIÊNCIA E TECNOLOGIA DE MATERIAIS E SENSORES TÍTULO I DOS Sensores (CMS), do Curso de Pós-graduação em Engenharia e Tecnologia Espaciais (ETE) do INPE, tem como Regimento dos Cursos de Pós-Graduação do INPE, pelas normas do Conselho de Pós-Graduação, pelo Regimento do
REGIMENTO DO CURSO DE PS-GRADUAO EM CINCIA DO SISTEMA TERRESTRE
REGIMENTO DO CURSO DE PÓS-GRADUAÇÃO EM CIÊNCIA DO SISTEMA TERRESTRE TÍTULO I DA ORGANIZAÇÃO Art. 1 - O Curso de Doutorado em Ciência do Sistema Terrestre do INPE tem como objetivo a formação de ambientais regionais e globais. Art. 2 - O Curso de Ciência do Sistema Terrestre (PG-CST) reger-se-á pelo
Estudo comparativo entre estrelas centrais de nebulosas planetárias deficientes em hidrogênio
NASA Astrophysics Data System (ADS)
Marcolino, W. L. F.; de Araújo, F. X.
2003-08-01
Apresentamos neste trabalho o resultado de um estudo das principais características espectrais das estrelas centrais de nebulosas planetárias (ECNP) deficientes em hidrogênio. A origem e a evolução dessas estrelas ainda constitui um problema em aberto na evolução estelar. Geralmente esses objetos são divididos em [WCE], [WCL] e [WELS]. Os tipos [WCE] e [WCL] apresentam um espectro típico de uma estrela Wolf-Rayet carbonada de população I e as [WELS] apresentam linhas fracas de carbono e oxigênio em emissão. Existem evidências que apontam a seguinte sequência evolutiva : [WCL] = > [WCE] = > [WELS] = > PG 1159 (pré anã-branca). No entanto, tal cenário apresenta falhas como por exemplo a falta de ECNP entre os tipos [WCL] e [WCE]. Baseados em uma amostra de 24 objetos obtida no telescópio de 1.52m em La Silla, Chile (acordo ESO/ON), ao longo do ano 2000, apresentamos os resultados da comparação das larguras equivalentes de diversas linhas relevantes entre os tipos [WCL], [WCE] e [WELS]. Verificamos que nossos dados estão de acordo com a sequência evolutiva. Baseado nas linhas de C IV, conseguimos dividir pela primeira vez as [WELS] em dois grupos principais. Além disso, os dados reforçam a afirmação de que as [WCE] são as estrelas que possuem a maior temperatura entre as ECNP deficientes em hidrogênio. Discutimos ainda, a escassez de dados disponíveis na literatura e a necessidade da obtenção de parametros físicos para estes objetos.
The Monte Carlo EM method for the parameter estimation of biological models
Horváth, András
(CTMC) is appro- priate for its modeling. Further, we assume that the evolution of the system under of the underlying CTMC, it is convenient to use such a variant of the EM approach, namely the Monte Carlo EM (MCEM, in particular, by a continuous time Markov chain (CTMC). In order to have a complete description of the CTMC
ModEM: A modular system for inversion of electromagnetic geophysical data
ModEM: A modular system for inversion of electromagnetic geophysical data Anna Kelbert a,n , Naser Accepted 26 January 2014 Available online 1 February 2014 Keywords: Geophysics Numerical modeling Inversion and inversion algorithms, providing a basis for a general modular system of computer codes for EM geophysical
Universidade Federal de Santa Catarina Curso de Pos-Graduac~ao em Matematica e
Lopes, Artur Oscar
Coordenador Comiss~ao Examinadora Prof. Dr. Aldrovando L. Azeredo AraÂ´ujo (UFSC-Orientador) Prof. Dr. Artur O professor Artur Lopes (UFRGS) que alÂ´em de ter participado da banca da defesa, me auxiliou em muitas quest
Myers, J Brent; Slovis, Corey M; Eckstein, Marc; Goodloe, Jeffrey M; Isaacs, S Marshal; Loflin, James R; Mechem, C Crawford; Richmond, Neal J; Pepe, Paul E
2008-01-01
There are few evidence-based measures of emergency medical services (EMS) system performance. In many jurisdictions, response-time intervals for advanced life support units and resuscitation rates for victims of cardiac arrest are the primary measures of EMS system performance. The association of the former with patient outcomes is not supported explicitly by the medical literature, while the latter focuses on a very small proportion of the EMS patient population and thus does not represent a sufficiently broad selection of patients. While these metrics have their place in performance measurement, a more robust method to measure and benchmark EMS performance is needed. The 2007 U.S. Metropolitan Municipalities' EMS Medical Directors' Consortium has developed the following model that encompasses a broader range of clinical situations, including myocardial infarction, pulmonary edema, bronchospasm, status epilepticus, and trauma. Where possible, the benefit conferred by EMS interventions is presented in the number needed to treat format. It is hoped that utilization of this model will serve to improve EMS system design and deployment strategies while enhancing the benchmarking and sharing of best practices among EMS systems. PMID:18379908
de alta potência. O pessoal da equipe de apoio técnico teve, em sua maior parte, dedicação em tempo pesquisa, Teoria e Engenharia) Dr. Edson Del Bosco (Operação da máquina, Diagnósticos, Chefe do LAP Tempo parcial) Dr. Joaquim José Barroso de Castro (Fontes de microondas Tempo parcial) Dr. Luiz Ângelo Berni
Chinese Verb Sense Discrimination Using an EM Clustering Model with Rich Linguistic Features
Chinese Verb Sense Discrimination Using an EM Clustering Model with Rich Linguistic Features of the Expectation-Maximization (EM) clustering algorithm to the task of Chinese verb sense discrimination. The model utilized rich linguistic features that capture predicate- argument structure information of the target
Hanford Site performance summary -- EM funded programs, July 1995
Schultz, E.A.
1995-07-01
Performance data for July 1995 reflects a 4% unfavorable schedule variance and is an improvement over June 1995. The majority of the behind schedule condition is attributed to EM-30, (Office of Waste Management). The majority of the EM-30 schedule variance is associated with the Tank Waste Remediation System (TWRS) Program. The TWRS schedule variance is attributed to the delay in obtaining key decision 0 (KD-0) for Project W-314, ``Tank Farm Restoration and Safe Operations`` and the Multi-Function Waste Tank Facility (MWTF) workscope still being a part of the baseline. Baseline Change Requests (BCRs) are in process rebaselining Project W-314 and deleting the MWTF from the TWRS baseline. Once the BCR`s are approved and implemented, the overall schedule variance will be reduced to $15.0 million. Seventy-seven enforceable agreement milestones were scheduled FYTD. Seventy-one (92%) of the seventy-seven were completed on or ahead of schedule, two were completed late and four are delinquent. Performance data reflects a continued significant favorable cost variance of $124.3 million (10%). The cost variance is attributed to process improvements/efficiencies, elimination of low-value work, workforce reductions and is expected to continue for the remainder of this fiscal year. A portion of the cost variance is attributed to a delay in billings which should self-correct by fiscal year-end.
The simulated online EM algorithm for latent factor models
NASA Astrophysics Data System (ADS)
Rohde, D.; Cappé, O.; Dikmen, O.
2012-10-01
The estimation of latent factor models are treated in an integrated maximum likelihood context where one parameter is marginalized and another is estimated. An extension to the online Expectation Maximization (EM) algorithm is employed the simulated online Expectation Maximization algorithm. Both these algorithms apply to exponential family models, but the simulated version of the algorithm can make use of Monte Carlo simulation to compute the stochastic E-steps while maintaining the convergence properties of the original online EM algorithm. A class of important latent factor models are identified that can be expressed in complete data exponential family form, the algorithm is applied to one of these models Itakura-Saito Non-negative Matrix Factorisation. An additional parameter is introduced into this model and it is conjectured if this is set to a high value the posterior variance of the parameters is reduced and estimation becomes easier. Simulations are provided that support this conjecture, although online estimation for models with even a modest number of components continues to be hampered by the presence of local minima.
Contactless ultrasonic treatment of melts using EM induction
NASA Astrophysics Data System (ADS)
Bojarevics, V.; Djambazov, G.; Lebon, G. S. B.; Pericleous, K. A.
2015-06-01
Ultrasound Treatment (UT) is commonly used in light alloys during solidification to refine microstructure, or disperse immersed particles. A sonotrode probe introduced into the melt generates sound waves that are strong enough to produce cavitation of dissolved gases. The same method cannot be used in high temperature melts, or for highly reactive alloys, due to probe erosion and melt contamination. An alternative, contactless method of generating sound waves is proposed and investigated theoretically in this paper, using electromagnetic (EM) induction. In addition to strong vibration, the EM induction currents generate strong stirring in the melt that aids distribution of the UT effect to large volumes of material. In a typical application, the same induction coil surrounding the crucible used to melt the alloy may be adopted for UT with suitable frequency tuning. Alternatively - or in addition - a top coil may be used. For industrial use, instead of multiple sonotrodes as has been the practice in scaling up, modelling shows that one simply has to alter the coil geometry and current to suit. To reach sinusoidal pressure fluctuations suitable for cavitation it may be necessary to tune the induction coil frequency for resonance, given the crucible dimensions.
Chapter 19: HVAC Controls (DDC/EMS/BAS) Evaluation Protocol
Romberger, J.
2014-11-01
The HVAC Controls Evaluation Protocol is designed to address evaluation issues for direct digital controls/energy management systems/building automation systems (DDC/EMS/BAS) that are installed to control heating, ventilation, and air-conditioning (HVAC) equipment in commercial and institutional buildings. (This chapter refers to the DDC/EMS/BAS measure as HVAC controls.) This protocol may also be applicable to industrial facilities such as clean rooms and labs, which have either significant HVAC equipment or spaces requiring special environmental conditions. This protocol addresses only HVAC-related equipment and the energy savings estimation methods associated with installing such control systems as an energy efficiency measure. The affected equipment includes: Air-side equipment (air handlers, direct expansion systems, furnaces, other heating- and cooling-related devices, terminal air distribution equipment, and fans); Central plant equipment (chillers, cooling towers, boilers, and pumps). These controls may also operate or affect other end uses, such as lighting, domestic hot water, irrigation systems, and life safety systems such as fire alarms and other security systems. Considerable nonenergy benefits, such as maintenance scheduling, system component troubleshooting, equipment failure alarms, and increased equipment lifetime, may also be associated with these systems. When connected to building utility meters, these systems can also be valuable demand-limiting control tools. However, this protocol does not evaluate any of these additional capabilities and benefits.
GLLH EM Invisible Cloak With Novel Front Branching And Without Exceed Light Speed Violation
Ganquan Xie; Jianhua Li; Lee Xie; Feng Xie
2010-05-21
In this paper, we propose new Global and Local (GL) electromagnetic (EM) cloaks with distinctive class material a_{\\alpha \\beta}\\log ^\\alpha (b_{\\alpha \\beta}/h) h^\\beta (GLLH Cloak) without exceed light speed violation. The refractive index of the GLLH cloak material, $n(r)$, is large than one or equal to one. Our GLLH cloak is created by GL EM modeling and GL EM cloak inversion with searching class \\it a_{\\alpha \\beta}\\log ^\\alpha (b_{\\alpha \\beta}/h) h^\\beta. The GLLH cloaks in this paper have finite speed and have no exceed light speed? physical violations and have more advantages. The GLLH EM cloaks can be practicable by using normal materials and are available for all broad frequency band. The GL EM cloak inversion and electromagnetic integral equation for cloak are presented in this paper. The novel EM wave propagation and front branching in the GLLH cloak by GL EM modeling are presented in this paper. The EM wave front propagation in GLLH cloak is behind of the front in free space. At time steps $118 dt$, in the GLLH cloak, the wave front is curved as a crescent like and propagates slower than the light in free space. At the time step $119dt$, the EM wave inside of the GLLH cloak propagates slower than light speed, moreover, its two crescent front peaks intersect at a front branching point. At the front branching point, the front is split to two fronts. The novel front branching and crescent like wave propagation are displayed in the following figure 1, figure 2 and figures 5 -20 in this paper. All copyright and patent of the GLLH EM cloaks and GL modeling and inversion methods are reserved by authors in GL Geophysical Laboratory.
Prevalence of Depression and Cognitive Impairment in Older Adult EMS Patients
Shah, Manish N.; Jones, Courtney M. C.; Richardson, Thomas M.; Conwell, Yeates; Katz, Paul; Schneider, Sandra M.
2010-01-01
Objectives To characterize the proportion of older adult ED patients with depression or cognitive impairment. To compare the prevalence of depression or cognitive impairment among ED patients arriving via EMS, as compared to other modes. Methods Community-dwelling older adults (age?60) presenting to an academic medical center ED were interviewed. Participants provided demographic and clinical information, and were evaluated for depression and cognitive impairment. Subjects arriving via EMS were compared to those arriving via other modes using the chi-square test, t-test, and the Wilcoxon rank sum test, where appropriate. Results Consent was obtained from 1342 eligible older adults; 695 (52%) arrived via EMS. The median age for those arriving via EMS was 74 (IQR 65, 82), 52% were female, 81% white. 15% of EMS patients had moderate or greater depression, as compared to 14% of patients arriving via other modes (p=0.52). 13% of EMS patients had cognitive impairment, as compared to 8% arriving via other modes (p<0.01). Depressed EMS patients frequently reported a history of depression (47%) and taking antidepressants (51%). Cognitively impaired EMS patients infrequently reported a history of dementia (16%) or taking medications for dementia (14%). Conclusions In this cohort of community-dwelling older adult ED patients depression and cognitive impairment were common. As compared to ED patients arriving by other transport means, patients arriving via EMS had similar prevalence of depression but an increased prevalence of cognitive impairment. Screening for depression and cognitive impairment by EMS providers may have value, but needs further investigation. PMID:20977363
The EM SSAB Annual Work Plan Process: Focusing Board Efforts and Resources - 13667
Young, Ralph
2013-07-01
One of the most daunting tasks for any new member of a local board of the Environmental Management Site Specific Advisory Board (EM SSAB) is to try to understand the scope of the clean-up activities going on at the site. In most cases, there are at least two or three major cleanup activities in progress as well as monitoring of past projects. When planning for future projects is added to the mix, the list of projects can be long. With the clean-up activities involving all major environmental media - air, water, soils, and groundwater, new EM SSAB members can find themselves totally overwhelmed and ineffective. Helping new members get over this initial hurdle is a major objective of EM and all local boards of the EM SSAB. Even as members start to understand the size and scope of the projects at a site, they can still be frustrated at the length of time it takes to see results and get projects completed. Many project and clean-up timelines for most of the sites go beyond 10 years, so it's not unusual for an EM SSAB member to see the completion of only 1 or 2 projects over the course of their 6-year term on the board. This paper explores the annual work planning process of the EM SSAB local boards, one tool that can be used to educate EM SSAB members into seeing the broader picture for the site. EM SSAB local work plans divide the site into projects focused on a specific environmental issue or media such as groundwater and/or waste disposal options. Projects are further broken down into smaller segments by highlighting major milestones. Using these metrics, local boards of the EM SSAB can start to quantify the effectiveness of the project in achieving the ultimate goal of site clean-up. These metrics can also trigger board advice and recommendations for EM. At the beginning of each fiscal year, the EM SSAB work plan provides a road map with quantifiable checkpoints for activities throughout the year. When the work plans are integrated with site-specific, enforceable regulatory milestones, they can provide a comprehensive work plan for not only the board, but also regulators, site contractors, and DOE. Because the work plans are reviewed and approved by DOE, they carry some weight in holding local boards of the EM SSAB accountable. This structure provides the basis for local boards to achieve their primary function, to provide DOE with information, advice, and recommendations concerning issues affecting the EM program at the site. (authors)
EM Properties of Magnetic Minerals at RADAR Frequencies
NASA Technical Reports Server (NTRS)
Stillman, D. E.; Olhoeft, G. R.
2005-01-01
Previous missions to Mars have revealed that Mars surface is magnetic at DC frequency. Does this highly magnetic surface layer attenuate RADAR energy as it does in certain locations on Earth? It has been suggested that the active magnetic mineral on Mars is titanomaghemite and/or titanomagnetite. When titanium is incorporated into a maghemite or magnetite crystal, the Curie temperature can be significantly reduced. Mars has a wide range of daily temperature fluctuations (303K - 143K), which could allow for daily passes through the Curie temperature. Hence, the global dust layer on Mars could experience widely varying magnetic properties as a function of temperature, more specifically being ferromagnetic at night and paramagnetic during the day. Measurements of EM properties of magnetic minerals were made versus frequency and temperature (300K- 180K). Magnetic minerals and Martian analog samples were gathered from a number of different locations on Earth.
Speech articulator measurements using low power EM-wave sensors
Holzrichter, J.F.; Burnett, G.C.; Ng, L.C.; Lea, W.A.
1998-01-01
Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions as speech is produced. Glottal tissue oscillations, jaw, tongue, soft palate, and other organs have been measured. Previously, microwave imaging (e.g., using radar sensors) appears not to have been considered for such monitoring. Glottal tissue movements detected by radar sensors correlate well with those obtained by established laboratory techniques, and have been used to estimate a voiced excitation function for speech processing applications. The noninvasive access, coupled with the small size, low power, and high resolution of these new sensors, permit promising research and development applications in speech production, communication disorders, speech recognition and related topics. {copyright} {ital 1998 Acoustical Society of America.}
PREFACE: EmQM13: Emergent Quantum Mechanics 2013
NASA Astrophysics Data System (ADS)
2014-04-01
These proceedings comprise the invited lectures of the second international symposium on Emergent Quantum Mechanics (EmQM13), which was held at the premises of the Austrian Academy of Sciences in Vienna, Austria, 3-6 October 2013. The symposium was held at the ''Theatersaal'' of the Academy of Sciences, and was devoted to the open exploration of emergent quantum mechanics, a possible ''deeper level theory'' that interconnects three fields of knowledge: emergence, the quantum, and information. Could there appear a revised image of physical reality from recognizing new links between emergence, the quantum, and information? Could a novel synthesis pave the way towards a 21st century, ''superclassical'' physics? The symposium provided a forum for discussing (i) important obstacles which need to be overcome as well as (ii) promising developments and research opportunities on the way towards emergent quantum mechanics. Contributions were invited that presented current advances in both standard as well as unconventional approaches to quantum mechanics. The EmQM13 symposium was co-organized by Gerhard Grössing (Austrian Institute for Nonlinear Studies (AINS), Vienna), and by Jan Walleczek (Fetzer Franklin Fund, USA, and Phenoscience Laboratories, Berlin). After a very successful first conference on the same topic in 2011, the new partnership between AINS and the Fetzer Franklin Fund in producing the EmQM13 symposium was able to further expand interest in the promise of emergent quantum mechanics. The symposium consisted of two parts, an opening evening addressing the general public, and the scientific program of the conference proper. The opening evening took place at the Great Ceremonial Hall (Grosser Festsaal) of the Austrian Academy of Sciences, and it presented talks and a panel discussion on ''The Future of Quantum Mechanics'' with three distinguished speakers: Stephen Adler (Princeton), Gerard 't Hooft (Utrecht) and Masanao Ozawa (Nagoya). The articles contained in these proceedings represent the talks of the invited speakers as written immediately after the symposium. The volume starts with a contribution by organizers Jan Walleczek and Gerhard Grössing, essentially explaining why emergent quantum mechanics, and other deterministic approaches to quantum theory, must be considered viable approaches in quantum foundations today. This is followed by the exposition of Stephen Adler's talk who introduced to a general audience key questions at the current frontiers of quantum mechanics during the opening evening (with the contents of his conference talk appearing elsewhere). The conference proceedings then continues with the presentations as given in their chronological order i.e. starting with the opening talk of the scientific program by Gerard 't Hooft. While the page number was restricted for all invited speakers, the paper by Jeff Tollaksen was given more space, as his invited collaborator Yakir Aharonov was unable to deliver a separate talk, in order to represent both contributions in one paper. Note that the talks of all speakers, including the talks of those who could not be represented in this volume (M. Arndt, B. Braverman, C. Brukner, S. Colin, Y. Couder, B. Poirier, A. Steinberg, G. Weihs and H. Wiseman) are freely available on the conference website as video presentations (http://www.emqm13.org). The organizers wish to express their gratitude to Siegfried Fussy and Herbert Schwabl from AINS for the organizational support. The organizers also wish to thank Bruce Fetzer, President and CEO, John E. Fetzer Memorial Trust, and the Members of the Board of Trustees, for their strong support and for funding this symposium. We also wish to thank the Austrian Academy of Sciences for allowing the symposium to be held on their premises, and Anton Zeilinger, President of the Austrian Academy of Sciences, for his welcome address. The expertise of the Members of the Scientific Advisory Board of the EmQM13 symposium, Ana Maria Cetto (Mexico), Lajos Diósi (Budapest), Maurice de Gosson (Vienna), Edward Nelson (Princeton), Theo Ni
EM modeling of RF drive in DTL tank 4
Kurennoy, Sergey S.
2012-06-19
A 3-D MicroWave Studio model for the RF drive in the LANSCE DTL tank 4 has been built. Both eigensolver and time-domain modeling are used to evaluate maximal fields in the drive module and RF coupling. The LANSCE DTL tank 4 has recently been experiencing RF problems, which may or may not be related to its replaced RF coupler. This situation stimulated a request by Dan Rees to provide EM modeling of the RF drive in the DTL tank 4 (T4). Jim O'Hara provided a CAD model that was imported into the CST Microwave Studio (MWS) and after some modifications became a part of a simplified MWS model of the T4 RF drive. This technical note describes the model and presents simulation results.
Detection of karst structures using airborne EM and VLF
Beard, L.P. Nyquist, J.E.; Carpenter, P.J.
1994-12-31
Through the combined use of multi-frequency helicopter electromagnetic and VLF data, it is possible to detect and delineate a wide variety of karst structures and possibly to assess their interconnectedness. Multi-frequency EM Can detect karst features if some element of the structure is conductive. This conductive aspect may derive from thick, moist soils in the depression commonly associated with a doline, from conductive fluids in the cavity, or from conductive sediments in the cavity if these occupy a significant portion of it. Multiple loop configurations may also increase the likelihood of detecting karst features. Preliminary evidence indicates total field VLF measurements may be able to detect interconnected karst pathways, so long as the pathways are water or sediment filled. Neither technique can effectively detect dry, resistive air-filled cavities.
Integrated EM & Thermal Simulations with Upgraded VORPAL Software
D.N. Smithe, D. Karipides, P. Stoltz, G. Cheng, H. Wang
2011-03-01
Nuclear physics accelerators are powered by microwaves which must travel in waveguides between room-temperature sources and the cryogenic accelerator structures. The ohmic heat load from the microwaves is affected by the temperature-dependent surface resistance and in turn affects the cryogenic thermal conduction problem. Integrated EM & thermal analysis of this difficult non-linear problem is now possible with the VORPAL finite-difference time-domain simulation tool. We highlight thermal benchmarking work with a complex HOM feed-through geometry, done in collaboration with researchers at the Thomas Jefferson National Accelerator Laboratory, and discuss upcoming design studies with this emerging tool. This work is part of an effort to generalize the VORPAL framework to include generalized PDE capabilities, for wider multi-physics capabilities in the accelerator, vacuum electronics, plasma processing and fusion R&D fields, and we will also discuss user interface and algorithmic upgrades which facilitate this emerging multiphysics capability.
Time-Lapse inversion of EM Tomography data for polymer-injected hydrocarbon reservoirs
NASA Astrophysics Data System (ADS)
Cheon, Seiwook; Park, Chanho; Nam, Myung Jin; Son, Jeong-Sul
2015-04-01
Polymer flooding is a method to increase the production of hydrocarbon reservoir by injecting polymer solution into the reservoir. For a study on the monitoring fluid variation within the reservoir, we first make analysis on seismic- and electromagnetic (EM)- tomography responses for seismic and electrical-resistivity rock physics models (RPMs) of the reservoir considering polymer fluid. Constructing RPMs are dependent on not only geologic characteristics of reservoir but also reservoir parameters such as fluid-type, fluid saturation, pressure and temperature. When making RPM for monitoring analysis, we assume the geology does not changes while reservoir parameters change to affect responses of seismic and EM tomography data. Specifically when constructing electrical-resistivity RPM, we consider three different types of hydrocarbon reservoirs, which are clean sand, shaly sand, sand-shale lamination, while considering two different types of waters (fresh water and salt water) to make 2wt% polymer solution. To compute time lapse EM and seismic tomography responses for corresponding RPMs of polymer-injected reservoirs, we used 2.5D finite element EM modeling algorithm and staggered-grid finite difference elastic modeling algorithm, respectively. Comparison between sensitivities of seismic and EM tomography to polymer injection confirms that EM tomography is more sensitivity to the polymer injection. For the evaluation of the potential of EM tomography to monitor polymer flooding, this study subsequently develops an efficient time-lapse EM tomography inversion algorithm based on the 2.5D EM tomography modeling. Using the inversion algorithm, we inverted the time-lapse EM tomography data to construct true resistivity models of polymer-injected reservoirs and analyze differences between them. From the time-lapse inversion results, we can observe the differences in time lapse responses between using fresh water and salt water have been decreased in the inverted time-lapse sections. Even though EM tomography has larger sensitivity than seismic tomography, EM tomography still has limitation in monitoring polymer flooding in a sense that the method simply detects changes due to the injection of fresh or salt water rather than polymer solution directly. However, the time-lapse inversion method developed in this study has many applications in monitoring fluid variation in other engineering fields.
EM Wake-Sleep Shiro.Ikeda@brain.riken.go.jp
Ikeda, Shiro
EM Wake-Sleep 21 2-1 Shiro.Ikeda@brain.riken.go.jp 1 (Latent Variable) 2 2.1 -5 -2.5 0 2.5 5 x+1), p(x; )) t+1 6 #12;3.3 Wake-Sleep EM G. Hinton EM Wake-Sleep [6] Helmholtz Helmholtz Helmholtz Helmholtz 6 M D q(y|x; ) p(x, y; ) 2 Wake-Sleep t+1 D M KL(q ,p )KL(p ,q ) t+1 t () ()() () t 7: Wake
The PX-EM algorithm for fast stable fitting of Henderson's mixed model
Foulley, Jean-Louis; Van Dyk, David A
2000-01-01
This paper presents procedures for implementing the PX-EM algorithm of Liu, Rubin and Wu to compute REML estimates of variance covariance components in Henderson's linear mixed models. The class of models considered encompasses several correlated random factors having the same vector length e.g., as in random regression models for longitudinal data analysis and in sire-maternal grandsire models for genetic evaluation. Numerical examples are presented to illustrate the procedures. Much better results in terms of convergence characteristics (number of iterations and time required for convergence) are obtained for PX-EM relative to the basic EM algorithm in the random regression. PMID:14736399
7. PHOTOCOPY, ELEVATIONS FOR E.M. BARRACKS, N.C.O. AND OFFICERS QUARTERS. ...
7. PHOTOCOPY, ELEVATIONS FOR E.M. BARRACKS, N.C.O. AND OFFICERS QUARTERS. - NIKE Missile Base SL-40, Barracks No. 1, North end of base, southest of Basketball Court & northwest of Barracks No. 2, Hecker, Monroe County, IL
Multibeam Swath Bathymetry The Kongsberg Simrad EM-3000 Multibeam system is a high resolution echo
Wright, Dawn Jeannine
Multibeam Swath Bathymetry The Kongsberg Simrad EM-3000 Multibeam system is a high resolution echo sounder which measures depth accurately to within several centimeters when post- processed. It not only
Instituto de Sistemas e Robotica
de skate montado desde sexta-feira no largo do Inten- dente Pina Manique, em Lis- boa. O pedido era Superior de Belas -Artes , de Lis - boa, e skater, teve a seu cargo as pinturas e criação dos trofeus
NASA Astrophysics Data System (ADS)
Kurihara, Hiroshi; Hirai, Yoshihito; Takizawa, Koji; Iwata, Takeo; Hashimoto, Osamu
The electronic toll collection (ETC) system is now beginning to widely use as part of the ITS which aims for the new environment in Japan road traffic. However, it is not fully prepared the environment for ETC system because of the communication interference caused by the multiple reflections from the constructions, such as the tollgate canopy and the elevated highway. In this paper, we propose a new improvement method to suppress the multiple reflections from the constructions by using EM wave absorber. We present the necessary absorption of EM wave absorber in the oblique incidence at 5.8GHz circular-polarized wave, abbreviated as CP wave, by using a basic radio propagation principle. Then, we develop the CP' EM wave absorber. Moreover, we experiment at the ETC system under the elevated highway in order to demonstrate the effectiveness of the CP' EM wave absorber. As a result, we were able to confirm effectiveness of the proposed new method.
Instituto Nacional de Pesquisas Espaciais Exame para o curso de ps-graduao em Astrofsica
for Extraterrestrial Intelligence), afirmava que o grande radiotelescópio de Arecibo, em Porto Rico, "pode detectar um magnético? b) A que aceleração ele é submetido? #12;6. Frank Drake, um dos criadores do projeto SETI (Search
Jardim, Wilson de Figueiredo
188 Oliveira et al. Quim. Nova SISTEMA DE INJEÇÃO EM FLUXO ESPECTROFOTOMÉTRICO PARA MONITORAR injection analysis; foto-Fenton. ArtigoQuim. Nova, Vol. 24, No. 2, 188-190, 2001. INTRODUÇÃO A reação foto
Um Framework para Proviso de QoS em Redes Mveis Sem Fio1
Colcher, Sérgio
provisão de QoS em redes móveis sem fio integrando soluções isoladas encontradas na literatura. Esses gerenciamento de suas localizações. Pode-se encontrar na literatura uma gama de trabalhos propondo soluções para
Approximate EM Learning on Large Computer Clusters Jorg Bornschein, Zhenwhen Dai and Jorg Lucke
= 8085 Kn = 16599 Software architecture model specific code is encapsulated in Model-classes Model://fias.uni-frankfurt.de/bornschein References [1] R.Neal, G. Hinton. A view of the EM algorithm that justifies incremental, sparse, and other
Teorias de Gauge e Conexoes em Fibrados Vectoriais 1 Relatividade e Electromagnetismo
NatÃ¡rio, JosÃ©
Teorias de Gauge e Conexâ?oes em Fibrados Vectoriais 1 Relatividade e Electromagnetismo A Teoria da Relatividade Especial identifica o espaâ?ºcoÂtempo com R 4 (com coordenadas Cartesianas (x 0 , x 1 , x 2 , x 3
EM techniques for archaeological laboratory experiments: preliminary results
NASA Astrophysics Data System (ADS)
Capozzoli, Luigi; De Martino, Gregory; Giampaolo, Valeria; Raffaele, Luongo; Perciante, Felice; Rizzo, Enzo
2015-04-01
The electromagnetic techniques (EM) are based on the investigation of subsoil geophysical parameters and in the archaeological framework they involve in studying contrasts between the buried cultural structures and the surrounding materials. Unfortunately, the geophysical contrast between archaeological features and surrounding soils sometimes are difficult to define due to problems of sensitivity and resolution both related on the characteristic of the subsoil and the geophysical methods. For this reason an experimental activity has been performed in the Hydrogeosite laboratory addressed on the assessment of the capability of geophysical techniques to detect archeological remains placed in the humid/saturated subsoil. At Hydrogeosite Laboratory of CNR-IMAA, a large scale sand-box is located, consisting on a pool shape structures of 230m3 where archaeological remains have been installed . The remains are relative to a living environment and burial of Roman times (walls, tombs, roads, harbour, etc.) covered by sediments. In order to simulate lacustrine and wetland condition and to simulate extreme events (for example underwater landslide, fast natural erosion coast, etc.) the phreatic level was varied and various acquisitions for the different scenarios were performed. In order to analyze the EM behavior of the buried small archaeological framework, ground penetrating radar (GPR) and electrical resistivity tomographies were performed. With GPR, analysis in time domain and frequency domain were performed and coupled to information obtained through resistivity analysis with the support of numerical simulations used to compare the real data with those modeled. A dense grid was adopted for 400 and 900 MHz e-m acquisitions in both the directions, the maximum depth of investigation was limited and less than 3 meters. The same approach was used for ERT acquisition where different array are employed, in particular 3D configuration was used to carry out a 3D resistivity model. The integration of electric and electromagnetic data allowed us to overcome the limits of each technique, especially in terms of resolution and depth, in humid/saturated conditions was investigated and the effectiveness of three-dimensional acquisitions was studied to better explore archeological sites and reduce the uncertainties related on the interpretation of geophysical analysis. The complexity of the relationship between archaeological features in the subsoil and their geophysical response requires efforts in the interpretation of resulting data. Reference Campana S. and Piro, S., (2009): Seeing the unseen - Geophysics and landscape archaeology., CRC Press, London, 2. No. of pages: 376. ISBN: 978-0-415-44721-8. Conyers, L. and Goodman, D., (1997): Ground-Penetrating Radar: An Introduction for Archaeologists. Walnut Creek, Calif.: AltaMira Press. Davis, J.L. and Annan, A.P. (1989): Ground-penetrating radar for high-resolution mapping of soil and rock stratigraphy. Geophysical Prospecting, 37, 531-551.
Desenho e Avaliao do sistema BOA com base em Padres de Interfaces Sociais
da Silva, Alberto Rodrigues
Desenho e AvaliaÃ§Ã£o do sistema BOA com base em PadrÃµes de Interfaces Sociais Alberto Rodrigues da-aprendizagem, como Ã© o caso da plataforma Bolsa de Objectos de Aprendizagem (BOA). Este trabalho surge no seguimento dinamizaÃ§Ã£o e participaÃ§Ã£o em comunidades suportadas pelo BOA. Este artigo, baseando-se na anÃ¡lise da
The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan
Fix, N. J.
2008-02-11
The Soils and Groundwater – EM-20 Science and Technology Roadmap Project is a U.S. Department of Energy, Office of Environmental Management-funded initiative designed to develop new methods, strategies and technology for characterizing, modeling, remediating, and monitoring soils and groundwater contaminated with metals, radionuclides, and chlorinated organics. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by EM-20 Roadmap Project staff.
Clarissa Coda dos Santos Cavalcanti Marques Animac~ao 3D em Tempo Real com Analises
Lewiner, Thomas (Thomas Lewiner)
Clarissa CodÂ´a dos Santos Cavalcanti Marques AnimaÂ¸c~ao 3D em Tempo Real com AnÂ´alises Harm^onicas CodÂ´a dos Santos Cavalcanti Marques AnimaÂ¸c~ao 3D em Tempo Real com AnÂ´alises Harm^onicas e Modal Tese Real com AnÂ´alises Harm^onicas e Modal / Clarissa CodÂ´a dos Santos Cavalcanti Marques; orientador
EM?IM: software for relating ion mobility mass spectrometry and electron microscopy data.
Degiacomi, Matteo T; Benesch, Justin L P
2016-01-01
We present EM?IM, software that allows the calculation of collision cross-sections from electron density maps obtained for example by means of transmission electron microscopy. This allows the assessment of structures other than those described by atomic coordinates with ion mobility mass spectrometry data, and provides a new means for contouring and validating electron density maps. EM?IM thereby facilitates the use of data obtained in the gas phase within structural biology studies employing diverse experimental methodologies. PMID:26616427
Curso de posgraduac~ao em Astrofisica Prova de admiss~ao
, 002603 u.m.a., ent~ao quanta energia de massa de repouso ´e convertida no decaimento? b) Em um referencial no qual o n´ucleo de 8 Be est´a inicialmente em repouso, qual ´e a energia cin´etica que cada n emiss~ao de energia eletromagn´etica) por seu corpo. Admita que seu corpo se comporte como um corpo
Estratgias de Integrao Reduzida para Clculo de Velocidades e Presses em Meios Porosos
Coutinho, Alvaro L. G. A.
EstratÃ©gias de IntegraÃ§Ã£o Reduzida para CÃ¡lculo de Velocidades e PressÃµes em Meios Porosos C. M meios porosos e reservatÃ³rios de petrÃ³leo. Para tanto, propÃµeÂse a utilizaÃ§Ã£o da IntegraÃ§Ã£o Reduzida na modelagem de problemas de escoamentos em meios porosos, incluindo a simulaÃ§Ã£o numÃ©rica de
Gregory, L.; Sheng, Z.; Hassan, A.; McDonald, A.; Porter, A.
2014-01-01
assessment of surface water and groundwater interactions; and (4) conduct the heliborne EM survey for the selected reaches and EM data analysis. The measures of success for this project included: ? Completed water resources database and GIS coverage... framework for the survey area. AgriLife Research conducted a preliminary review of the hydrogeological data gathered from existing sources to gain a better understanding of the known temporal and spatial variations of groundwater quality and to identify...
New Developments in the Technology Readiness Assessment Process in US DOE-EM - 13247
Krahn, Steven; Sutter, Herbert; Johnson, Hoyt
2013-07-01
A Technology Readiness Assessment (TRA) is a systematic, metric-based process and accompanying report that evaluates the maturity of the technologies used in systems; it is designed to measure technology maturity using the Technology Readiness Level (TRL) scale pioneered by the National Aeronautics and Space Administration (NASA) in the 1980's. More recently, DoD has adopted and provided systematic guidance for performing TRAs and determining TRLs. In 2007 the GAO recommended that the DOE adopt the NASA/DoD methodology for evaluating technology maturity. Earlier, in 2006-2007, DOE-EM had conducted pilot TRAs on a number of projects at Hanford and Savannah River. In March 2008, DOE-EM issued a process guide, which established TRAs as an integral part of DOE-EM's Project Management Critical Decision Process. Since the development of its detailed TRA guidance in 2008, DOE-EM has continued to accumulate experience in the conduct of TRAs and the process for evaluating technology maturity. DOE has developed guidance on TRAs applicable department-wide. DOE-EM's experience with the TRA process, the evaluations that led to recently developed proposed revisions to the DOE-EM TRA/TMP Guide; the content of the proposed changes that incorporate the above lessons learned and insights are described. (authors)
Operation Protective Edge - A Unique Challenge for a Civilian EMS Agency.
Jaffe, Eli; Strugo, Refael; Wacht, Oren
2015-10-01
During July through August 2014, Operation Protective Edge, a military conflict between Israel and the Hamas regime in Gaza, dramatically affected both populations. Magen David Adom (MDA), the Israeli national Emergency Medical Service (EMS) and a member of the Red Cross, faced a unique challenge during the conflict: to continue providing crucial service to the entire civilian population of Israel, which was under constant missile threat. This challenge included not only providing immediate care for routine EMS calls under missile threat, but also preparing and delivering immediate care to civilians injured in attacks on major cities, as well as small communities, in Israel. This task is a challenge for a civilian EMS agency that normally operates in a non-military environment, yet, in an instant, must enhance its capability to respond to a considerable threat to its population. During Operation Protective Edge, MDA provided care for 842 wounded civilians and utilized a significant amount of its resources. Providing EMS services for a civilian population in a mixed civilian/military scenario is a challenging task on a national level for an EMS system, especially when the threat lasts for weeks. This report describes MDA's preparedness and operations during Operation Protective Edge, and the unique EMS challenges and dilemmas the agency faced. PMID:26323985
High-speed computation of the EM algorithm for PET image reconstruction
Rajan, K.; Patnaik, L.M.; Ramakrishna, J. )
1994-10-01
The PET image reconstruction based on the EM algorithm has several attractive advantages over the conventional convolution backprojection algorithms. However, two major drawbacks have impeded the routine use of the EM algorithm, namely, the long computational time due to slow convergence and the large memory required for the storage of the image, projection data and the probability matrix. In this study, the authors attempts to solve these two problems by parallelizing the EM algorithm on a multiprocessor system. The authors have implemented an extended hypercube (EH) architecture for the high-speed computation of the EM algorithm using the commercially available fast floating point digital signal processor (DSP) chips as the processing elements (PEs). The authors discuss and compare the performance of the EM algorithm on a 386/387 machine, CD 4360 mainframe, and on the EH system. The results show that the computational speed performance of an EH using DSP chips as PEs executing the EM image reconstruction algorithm is about 130 times better than that of the CD 4360 mainframe. The EH topology is expandable with more number of PEs.
Experiências internacionais da aplicação de sistemas de apoio à decisão clínica em gastroenterologia
Tenório, Josceli Maria; Hummel, Anderson Diniz; Sdepanian, Vera Lucia; Pisa, Ivan Torres; de Fátima Marin, Heimar
2015-01-01
Objetivo Descrever as experiências recentes com a aplicação de sistemas de apoio à decisão clínica em gastroenterologia, de forma a estabelecer o nível de desenvolvimento, testes e vantagens conferidas à prática médica com a introdução desses softwares. Métodos Foi realizada busca nas bases de dados PubMed, LILACS e ISI Web of Knowledge, utilizando termos relacionados à sistemas de apoio à decisão e à gastroenterogia, incluindo artigos originais publicados no período entre 2005 e 2010. Foram recuperadas 104 publicações, na busca inicial e, após a aplicação dos critérios de inclusão e exclusão, foram eleitos nove estudos para leitura do texto completo. Resultados Os sistemas de apoio à decisão clínica apresentam grande multiplicidade de problemas clínicos e investigação de doenças. Em 89% dos casos, são descritos modelos experimentais para o desenvolvimento de sistemas de apoio à decisão clínica. A descrição dos resultados obtidos por técnicas de inteligência artificial em 78% das publicações. Em dois dos estudos foram realizadas comparações com o médico e em apenas uma publicação um estudo controlado foi descrito, mostrando evidências de melhorias na prática médica. Conclusão Os estudos mostram potenciais benefícios dos sistemas de apoio à decisão clínica à prática médica, porém, estudos controlados em ambiente real devem ser realizados para comprovar esta perspectiva. PMID:26491625
EM modeling for GPIR using 3D FDTD modeling codes
Nelson, S.D.
1994-10-01
An analysis of the one-, two-, and three-dimensional electrical characteristics of structural cement and concrete is presented. This work connects experimental efforts in characterizing cement and concrete in the frequency and time domains with the Finite Difference Time Domain (FDTD) modeling efforts of these substances. These efforts include Electromagnetic (EM) modeling of simple lossless homogeneous materials with aggregate and targets and the modeling dispersive and lossy materials with aggregate and complex target geometries for Ground Penetrating Imaging Radar (GPIR). Two- and three-dimensional FDTD codes (developed at LLNL) where used for the modeling efforts. Purpose of the experimental and modeling efforts is to gain knowledge about the electrical properties of concrete typically used in the construction industry for bridges and other load bearing structures. The goal is to optimize the performance of a high-sample-rate impulse radar and data acquisition system and to design an antenna system to match the characteristics of this material. Results show agreement to within 2 dB of the amplitudes of the experimental and modeled data while the frequency peaks correlate to within 10% the differences being due to the unknown exact nature of the aggregate placement.
As interfaces grficas vem sendo desenvolvidas em TCL/TK em conjunto com a sua extenso, o iTCL/iTK.
de Figueiredo, Luiz Henrique
Distribuída. SIBGRAPI'96. Caxambu, MG, Out., 1996. p. 1522. C. Esperança et al., 3D Viewer: Um Visualizador 3D Utilizando OpenGL e TCL/TK. SIBGRAPI'96. Caxambu, MG, Out, 1996. p. 345346. M. Zuffo et al., Um utilização de scanners espaciais, em especial na Medicina, como a Tomografia Computadorizada (TC
ERIC Educational Resources Information Center
Waters, John K.
2011-01-01
K-12-level competitive robotics is growing in popularity around the country and worldwide. According to one of the leading organizers of these events, FIRST--For Inspiration and Recognition of Science and Technology--250,000 students from 56 countries take part in its competitions. FIRST Tech Challenge (FTC) is a yearly event the organization puts…
Designing ergonomic interventions for EMS workers: concept generation of patient-handling devices.
Conrad, Karen M; Reichelt, Paul A; Lavender, Steven A; Gacki-Smith, Jessica; Hattle, Sally
2008-11-01
Fire service personnel and private ambulance paramedics suffer musculoskeletal injuries as they lift and carry patients while performing emergency medical services (EMS). Engineering changes, such as the design of new EMS patient-handling devices, offer a potential intervention opportunity for combating this problem. The purpose of this qualitative descriptive study was to generate beginning ideas for the design of new EMS patient-handling devices that were framed within the contextual reality of the end user firefighter/paramedics. Guided by an ecological model of musculoskeletal injuries in the fire service, focus groups were conducted with 25 firefighter/paramedics from 13 suburban fire departments. Based on their availability, participants were assigned to one of three groups with each group focusing on a different EMS patient-handling scenario. Each group participated in two focus group sessions: one session to brainstorm ideas for devices and a second session to validate sketches of their design ideas. The sketches were professionally drawn by an industrial designer who attended all focus group sessions. Sketches, photos, videotapes, and written transcripts were content analyzed to describe the phenomena of interest. The ideas centered on EMS devices for lateral transfers, bed-to-stairchair transfers, and stair descent transport, and served as the starting point for the development of EMS devices in subsequent phases of a mixed method research study. The outcomes of this study were an improved understanding of the contextual issues that need to be considered in designing EMS patient handling devices and a set of industrial design sketches that served as a starting point for subsequent development of the devices. End user acceptance criteria for the devices included: affordability, portability/compactness, durability, operability including being quickly ready for use, and cleanability. PMID:18222413
Accurate 2D/3D electromagnetic modeling for time-domain airborne EM systems
NASA Astrophysics Data System (ADS)
Yin, C.; Hodges, G.
2012-12-01
The existing industry software cannot deliver correct results for 3D time-domain airborne EM responses. In this paper, starting from the Fourier transform and convolution, we compare the stability of different modeling techniques and analyze the reason for instable calculations of the time-domain airborne EM responses. We find that the singularity of the impulse responses of EM systems at very early time that are used in the convolution is responsible for the instability of the modeling (Fig.1). Based on this finding, we put forward an algorithm that uses step response rather than impulse response of the airborne EM system for the convolution and create a stable algorithm that delivers precise results and maintains well the integral/derivative relationship between the magnetic field B and the magnetic induction dB/dt. A three-step transformation procedure for the modeling is proposed: 1) output the frequency-domain EM response data from the existing software; 2) transform into step-response by digital Fourier/Hankel transform; 3) convolve the step response with the transmitting current or its derivatives. The method has proved to be working very well (Fig. 2). The algorithm can be extended to the modeling of other time-domain ground and airborne EM system responses.Fig. 1: Comparison of impulse and step responses for an airborne EM system Fig. 2: Bz and dBz/dt calculated from step (middle panel) and impulse responses (lower panel) for the same 3D model as in Fig.1.
Boubaker, Ghalia; Hemphill, Andrew; Huber, Cristina Olivia; Spiliotis, Markus; Babba, Hamouda; Gottstein, Bruno
2015-01-01
Alveolar echinococcosis (AE) is caused by infection with the larval stage of the tapeworm Echinococcus multilocularis. An increasing understanding of immunological events that account for the metacestode survival in human and murine AE infection prompted us to undertake explorative experiments tackling the potential of novel preventive and/or immunotherapeutic measures. In this study, the immunoprotective and immunotherapeutic ability of recombinant EmP29 antigen (rEmP29) was assessed in mice that were intraperitoneally infected with E. multilocularis metacestodes. For vaccination, three intraperitoneal injections with 20?g rEmP29 emulsified in saponin adjuvants were applied over 6 weeks. 2 weeks after the last boost, mice were infected, and at 90 days post-infection, rEmP29-vaccinated mice exhibited a median parasite weight that was reduced by 75% and 59% when compared to NaCl- or saponin–treated control mice, respectively. For immunotherapeutical application, the rEmP29 (20?g) vaccine was administered to experimentally infected mice, starting at 1 month post-infection, three times with 2 weeks intervals. Mice undergoing rEmP29 immunotherapy exhibited a median parasite load that was reduced by 53% and 49% when compared to NaCl- and saponin–treated control mice, respectively. Upon analysis of spleen cells, both, vaccination and treatment with rEmP29, resulted in low ratios of Th2/Th1 (IL-4/IFN-?) cytokine mRNA and low levels of mRNA coding for IL-10 and IL-2. These results suggest that reduction of the immunosuppressive environment takes place in vaccinated as well as immunotreated mice, and a shift towards a Th1 type of immune response may be responsible for the observed increased restriction of parasite growth. The present study provides the first evidence that active immunotherapy may present a sustainable route for the control of AE. PMID:26053794
EM-54 Technology Development In Situ Remediation Integrated Program. Annual report
Not Available
1993-08-01
The Department of Energy (DOE) established the Office of Technology Development (EM-50) as an element of Environmental Restoration and Waste Management (EM) in November 1989. EM manages remediation of all DOE sites as well as wastes from current operations. The goal of the EM program is to minimize risks to human health, safety and the environment, and to bring all DOE sites into compliance with Federal, state, and local regulations by 2019. EM-50 is charged with developing new technologies that are safer, more effective and less expensive than current methods. The In Situ Remediation Integrated Program (the subject of this report) is part of EM-541, the Environmental Restoration Research and Development Division of EM-54. The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: Significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces; in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP tends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years.
Schwartz, Brian; Nafziger, Sarah; Milsten, Andrew; Luk, Jeffrey; Yancey, Arthur
2015-01-01
Mass gatherings are heterogeneous in terms of size, duration, type of event, crowd behavior, demographics of the participants and spectators, use of recreational substances, weather, and environment. The goals of health and medical services should be the provision of care for participants and spectators consistent with local standards of care, protection of continuing medical service to the populations surrounding the event venue, and preparation for surge to respond to extraordinary events. Pre-event planning among jurisdictional public health and EMS, acute care hospitals, and event EMS is essential, but should also include, at a minimum, event security services, public relations, facility maintenance, communications technicians, and the event planners and organizers. Previous documented experience with similar events has been shown to most accurately predict future needs. Future work in and guidance for mass gathering medical care should include the consistent use and further development of universally accepted consistent metrics, such as Patient Presentation Rate and Transfer to Hospital Rate. Only by standardizing data collection can evaluations be performed that link interventions with outcomes to enhance evidence-based EMS services at mass gatherings. Research is needed to evaluate the skills and interventions required by EMS providers to achieve desired outcomes. The event-dedicated EMS Medical Director is integral to acceptable quality medical care provided at mass gatherings; hence, he/she must be included in all aspects of mass gathering medical care planning, preparations, response, and recovery. Incorporation of jurisdictional EMS and community hospital medical leadership, and emergency practitioners into these processes will ensure that on-site care, transport, and transition to acute care at appropriate receiving facilities is consistent with, and fully integrated into the community's medical care system, while fulfilling the needs of event participants. Key words: mass gathering medicine; event medicine; event medical care planning; EMS medical director; prehospital. PMID:26270473
Pre-flight risk assessment in Emergency Medical Service (EMS) helicopters
NASA Technical Reports Server (NTRS)
Shively, R. J.
1992-01-01
The Emergency Medical Service (EMS) industry has been the subject of several television and newspaper articles (Harvey and Jensen, 1987) which emphasized the negative aspects, (e.g., fatalities and high accident rates), rather than the life saving services performed. Until recently, the accident rate of the EMS industry has been five times as high as that of other civil helicopters. This high accident rate has been coupled with the dramatic rise in the number of programs. The industry has built from a single service at its inception in 1972, to over 180 in 1987 (Spray, 1987), to the point that 93 percent of the contiguous U.S. is now covered by some type of EMS service. These factors prompted the National Transportation Safety Board (NTSB) to study the accidents that occurred between May 11, 1978 and December 3, 1986 (NTSB, 1988). The NTSB report concluded that 'Sound pilot judgment is central to safe flight operations.' They further stated that '... factors unique to EMS helicopter operations--such as the influence of the mission itself, program competition, and EMS program management perspectives--can drastically influence pilot judgment during the EMS mission.' One of the most difficult decisions that a pilot must make is whether to accept or decline a mission. A pre-flight risk assessment system (SAFE) was developed at NASA-Ames Research Center for civil EMS operations to aid pilots in making this decision objectively. The ability of the SAFE system to predict mission risk profiles was tested at an EMS facility. The results of this field study demonstrated that the usefulness of SAFE was highly dependent on the type of mission flown. SAFE is now being modified so that it can 'learn' with each mission flown. For example, after flying a mission to a particular site, an EMS pilot would input information about this mission into the system, such as new buildings, wires, or approach procedures. Then, the next time a pilot flew a similar mission or one to the same area, this additional information would be taken into account in computing a risk assessment.
Scalable and Interactive Segmentation and Visualization of Neural Processes in EM Datasets
Jeong, Won-Ki; Beyer, Johanna; Hadwiger, Markus; Vazquez, Amelio; Pfister, Hanspeter; Whitaker, Ross T.
2011-01-01
Recent advances in scanning technology provide high resolution EM (Electron Microscopy) datasets that allow neuroscientists to reconstruct complex neural connections in a nervous system. However, due to the enormous size and complexity of the resulting data, segmentation and visualization of neural processes in EM data is usually a difficult and very time-consuming task. In this paper, we present NeuroTrace, a novel EM volume segmentation and visualization system that consists of two parts: a semi-automatic multiphase level set segmentation with 3D tracking for reconstruction of neural processes, and a specialized volume rendering approach for visualization of EM volumes. It employs view-dependent on-demand filtering and evaluation of a local histogram edge metric, as well as on-the-fly interpolation and ray-casting of implicit surfaces for segmented neural structures. Both methods are implemented on the GPU for interactive performance. NeuroTrace is designed to be scalable to large datasets and data-parallel hardware architectures. A comparison of NeuroTrace with a commonly used manual EM segmentation tool shows that our interactive workflow is faster and easier to use for the reconstruction of complex neural processes. PMID:19834227
Final report: Key comparison of 50/60 Hz power SIM.EM-K5
NASA Astrophysics Data System (ADS)
Carranza, R.; Campos, S.; Castruita, A.; Nelson, T.; Ribeiro, A.; So, E.; Di Lillo, L.; Spaggiari, A.; Slomovitz, D.; Izquierdo, Daniel; Faverio, Carlos; Postigo, H.; Díaz, H.; Sanchez, H.; Gonzalez, J.; Zipaquirá Triana, Álvaro
2015-01-01
Under the auspices of the Committee Consultative of Electromagnetism, CCEM, the SIM Electromagnetic Working Group carried out a key comparison of power standards at 50/60 Hz. This key comparison, identified as SIM.EM-K5, aims to provide a link to various NMIs in the SIM region to the CCEM-K5 key comparison on 50/60 Hz power completed in 2001 and piloted by NIST. Measurements in the SIM.EM-K5 comparison were carried out from May 2010 to March 2012, including testing points of active and reactive power. CENAM was the pilot laboratory. Differences between the measurement results of the participating laboratories and the reference value of this key comparison, calculated at each of all the testing points, show a good infrastructure of national standards of measurement of electric power in the SIM region. Based on previous work, a link has been estimated between the results of the CCEM-K5 and the SIM.EM-K5 key comparisons, whose results were reported in 2002 and 2014, respectively. From the link it is shown that the measurement results of SIM.EM-K5 comparison are well supported. The SIM.EM-K5 comparison is a rewording exercise of comparison of the national standards of measurement as recommended by the CIPM. The participating laboratories are fully recommended for their enthusiastic participation in the comparison. Their individual efforts to maintain the national standards of power measurement are acknowledged.
Description and comparison of algorithms for correcting anisotropic magnification in cryo-EM images.
Zhao, Jianhua; Brubaker, Marcus A; Benlekbir, Samir; Rubinstein, John L
2015-11-01
Single particle electron cryomicroscopy (cryo-EM) allows for structures of proteins and protein complexes to be determined from images of non-crystalline specimens. Cryo-EM data analysis requires electron microscope images of randomly oriented ice-embedded protein particles to be rotated and translated to allow for coherent averaging when calculating three-dimensional (3D) structures. Rotation of 2D images is usually done with the assumption that the magnification of the electron microscope is the same in all directions. However, due to electron optical aberrations, this condition is not met with some electron microscopes when used with the settings necessary for cryo-EM with a direct detector device (DDD) camera. Correction of images by linear interpolation in real space has allowed high-resolution structures to be calculated from cryo-EM images for symmetric particles. Here we describe and compare a simple real space method, a simple Fourier space method, and a somewhat more sophisticated Fourier space method to correct images for a measured anisotropy in magnification. Further, anisotropic magnification causes contrast transfer function (CTF) parameters estimated from image power spectra to have an apparent systematic astigmatism. To address this problem we develop an approach to adjust CTF parameters measured from distorted images so that they can be used with corrected images. The effect of anisotropic magnification on CTF parameters provides a simple way of detecting magnification anisotropy in cryo-EM datasets. PMID:26087140
Single-particle cryo-EM of the ryanodine receptor channel in an aqueous environment
Baker, Mariah R.; Fan, Guizhen; Serysheva, Irina I.
2015-01-01
Ryanodine receptors (RyRs) are tetrameric ligand-gated Ca2+ release channels that are responsible for the increase of cytosolic Ca2+ concentration leading to muscle contraction. Our current understanding of RyR channel gating and regulation is greatly limited due to the lack of a high-resolution structure of the channel protein. The enormous size and unwieldy shape of Ca2+ release channels make X-ray or NMR methods difficult to apply for high-resolution structural analysis of the full-length functional channel. Single-particle electron cryo-microscopy (cryo-EM) is one of the only effective techniques for the study of such a large integral membrane protein and its molecular interactions. Despite recent developments in cryo-EM technologies and break-through single-particle cryo-EM studies of ion channels, cryospecimen preparation, particularly the presence of detergent in the buffer, remains the main impediment to obtaining atomic-resolution structures of ion channels and a multitude of other integral membrane protein complexes. In this review we will discuss properties of several detergents that have been successfully utilized in cryo-EM studies of ion channels and the emergence of the detergent alternative amphipol to stabilize ion channels for structure-function characterization. Future structural studies of challenging specimen like ion channels are likely to be facilitated by cryo-EM amenable detergents or alternative surfactants. PMID:25844145
Transport quantique dans des nanostructures
NASA Astrophysics Data System (ADS)
Naud, C.
2002-09-01
Quantum transport in nanostructures This work is devoted to the design, fabrication and magnetotransport investigations of mesoscopic devices. The sample are obtain by e-beam lithography and the measurements are performed at low temperature in a dilution refrigerator in the presence of a magnetic field. We have used MBE grown AlGaAs/GaAs heterojonctions as starting material to fabricate a bipartite tiling of rhombus called mathcal{T}3 lattice. We observe for the first time large amplitude h/e oscillations in this network as compared to the one measured in square lattices of similar size. These oscillations are the signature of a recently predited localization phenomenon induced by Aharonov-Bohm interferences on this peculiar topology. For particular values of the magnetic field the propagation of the electron wave function is bounded in a small number of cells, called Aharonov-Bohm cages. More strikingly, at high magnetic field, h/2e oscillations appear whose amplitude can be much higher than the fundamental period. Their temperature dependence is similar to that of the h/e signal. These observations withdraw a simple interpretation in terms of harmonics generation. The origin of this phenomenon is still unclear and needs more investigations. The influence electrical width of the wire defining the network and so the rule of the number of channels can be studied using a gate deposited over the lattice. In particular we have measured the amplitude dependence of the h/e and h/2e signal versus the gate voltage. Ce travail est consacré à la réalisation d'échantillons mésoscopiques à partir de la lithographie électronique ainsi qu'à leur caractérisation à très basse température en magnétotransport. Nous avons pour cela exploité le gaz bidimensionnel d'électrons situé à l'interface d'une hétérojonction AlGaAs/GaAs pour réaliser un réseau de boucle d'une géométrie particulière baptisée la géométrie mathcal{T}3. Nous avons observé sur cette structure des oscillations de conductance en fonction du flux du champ magnétique de période h/e dont l'amplitude est beaucoup plus importante que celle mesurée sur un réseau carré de même dimension. Cette différence constitue une signature d'un effet de localisation induit par le champ magnétique sur la topologie mathcal{T}3. Pour des valeurs spécifiques du champ magnétique, du fait des interférences destructives Aharonov-Bohm, la propagation des fonctions d'ondes est limitée à un ensemble fini de cellule du réseau appelé cage. De la dépendance en température des oscillations de période h/e mesurées sur le réseau mathcal{T}3 nous avons tiré une longueur caractéristique qui peut être rattachée au périmètre des cages. Un phénomène inattendu fut l'observation, pour des champs magnétiques plus importants, d'un doublement de fréquence des oscillations. Ces oscillations de période h/2e pouvant avoir une amplitude supérieure aux oscillations de période h/e, une interprétation en terme d'harmonique n'est pas possible. Enfin, l'influence de la largeur électrique des fils constituant le réseau et donc celle du nombre de canaux par brin a été étudiée en réalisant des grilles électrostatique. Les variations de l'amplitude des signaux en h/e et h/2e en fonction de la tension de grille ont été mesurés.
Evaluation model calculations with the water reactor analysis package (WRAP-EM)
Gregory, M.V.; Beranek, F.
1982-01-01
The Water Reactor Analysis Package-Evaluation Model (WRAP-EM) is a modular system of computer codes designed to provide the safety analyst with the capability of performing complete loss-of-coolant calculations for both pressurized- and boiling-water reactor systems. The system provides a licensing-type calculation capability and thus contains most of the Nuclear Regulatory Commission-Approved EM options, as described in the Code of Federal Regulations, Title 10, Part 50, Appendix K. All phases of an accident (blowdown, refill, and reflood) are modeled. The WRAP consists of modified versions of five preexisting codes (RELAP4/MOD5, GAPCON, FRAP, MOXY, and NORCOOL), the necessary interfaces to permit automatic transition from one code to the next during the transient calculations, plus a host of user-convenience features to aid the analyst faced with a multitude of EM calculations. The WRAP has been verified against both calculated and experimental results.
Experience with the EM-60 electromagnetic system for geothermal exploration in Nevada
Wilt, M.; Goldstein, N.E.; Stark, M.; Haught, J.R.; Morrison, H.F.
1981-09-01
Lawrence Berkeley Laboratory (LBL) conducted controlled-source electromagnetic (EM) surveys at three geothermal prospects in northern Nevada. Over 40 soundings were made in Panther Canyon (Grass Valley), near Winnemucca; Soda Lakes, near Fallon; and McCoy, west of Austin, to test and demonstrate the applicability of LBL's EM-60 system to geothermal exploration. The EM-60 is a frequency-domain system using three-component magnetic detection. Typically, +-65 A is applied to an 100-m-diameter four-turn horizontal loop, generating a dipole moment >10/sup 6/ MKS over the frequency range 10/sup -3/ to 10/sup -3/ Hz. With such a source loop, soundings were made, at transmitter-receiver separations of up to 4 km, providing a maximum depth of penetration of 4 km.
NASA Astrophysics Data System (ADS)
Khambampati, A. K.; Rashid, A.; Kim, B. S.; Liu, Dong; Kim, S.; Kim, K. Y.
2010-04-01
EIT has been used for the dynamic estimation of organ boundaries. One specific application in this context is the estimation of lung boundaries during pulmonary circulation. This would help track the size and shape of lungs of the patients suffering from diseases like pulmonary edema and acute respiratory failure (ARF). The dynamic boundary estimation of the lungs can also be utilized to set and control the air volume and pressure delivered to the patients during artificial ventilation. In this paper, the expectation-maximization (EM) algorithm is used as an inverse algorithm to estimate the non-stationary lung boundary. The uncertainties caused in Kalman-type filters due to inaccurate selection of model parameters are overcome using EM algorithm. Numerical experiments using chest shaped geometry are carried out with proposed method and the performance is compared with extended Kalman filter (EKF). Results show superior performance of EM in estimation of the lung boundary.
Direct and indirect measures of speech articulator motions using low power EM sensors
Barnes, T; Burnett, G; Gable, T; Holzrichter, J F; Ng, L
1999-05-12
Low power Electromagnetic (EM) Wave sensors can measure general properties of human speech articulator motions, as speech is produced. See Holzrichter, Burnett, Ng, and Lea, J.Acoust.Soc.Am. 103 (1) 622 (1998). Experiments have demonstrated extremely accurate pitch measurements (< 1 Hz per pitch cycle) and accurate onset of voiced speech. Recent measurements of pressure-induced tracheal motions enable very good spectra and amplitude estimates of a voiced excitation function. The use of the measured excitation functions and pitch synchronous processing enable the determination of each pitch cycle of an accurate transfer function and, indirectly, of the corresponding articulator motions. In addition, direct measurements have been made of EM wave reflections from articulator interfaces, including jaw, tongue, and palate, simultaneously with acoustic and glottal open/close signals. While several types of EM sensors are suitable for speech articulator measurements, the homodyne sensor has been found to provide good spatial and temporal resolution for several applications.
Physics-based simulation of EM and SM in TSV-based 3D IC structures
Kteyan, Armen; Sukharev, Valeriy; Zschech, Ehrenfried
2014-06-19
Evolution of stresses in through-silicon-vias (TSVs) and in the TSV landing pad due to the stress migration (SM) and electromigration (EM) phenomena are considered. It is shown that an initial stress distribution existing in a TSV depends on its architecture and copper fill technology. We demonstrate that in the case of proper copper annealing the SM-induced redistribution of atoms results in uniform distributions of the hydrostatic stress and concentration of vacancies along each segment. In this case, applied EM stressing generates atom migration that is characterized by kinetics depending on the preexisting equilibrium concentration of vacancies. Stress-induced voiding in TSV is considered. EM induced voiding in TSV landing pad is analyzed in details.
EM Safety Innovations Aim Toward Safer Technologies and Better Information for Users
Lankford, M.; Geiger, J.; Carpenter, C.
2002-02-26
Beginning in 2000, the Department of Energy's Office of Environmental Management (EM), Office of Science and Technology (OST) has substantially re-examined and improved our approach to worker safety and health. Consistent with OST's responsibilities for safety, these initiatives can be categorized generally as: (1) Making our technologies inherently safer to use; and (2) Providing useful safety and health information about our technologies to the sites and technology operators. This evolved through a collaborative process by the EM Office of Safety, Health and Security, the EM Office of Science and Technology, EM Focus Areas and others. It was, initially, largely in response to a set of eight recommendations by the Environmental Management Advisory Board (EMAB) and to lessons learned from a serious accident in August, 2000 involving an OST-funded new technology. The cornerstone of this effort is the Policy for Occupational Safety and Health in EM's Science and Technology Program, issued in January 2001. DOE Focus Areas are focusing more attention on worker safety and health in their solicitations and procurement documents for new technology research and development (R&D) projects. EM Headquarters is working with Focus Areas, site environmental contractors, technology developers, and their respective DOE field organizations to ensure that roles and responsibilities for worker safety and health are clearly defined when a new technology is demonstrated at an environmental management site. The peer review process administered by the American Society of Mechanical Engineers (ASME) now requires technology developers to think through their approach to safety and health in a more detailed, focused way than previously. In Innovative Technology Summary Reports (ITSRs), developers are comparing their new technologies to baseline technologies on the basis of safety and health. Technology Safety Data Sheets (TSDSs) are being prepared for new technologies when they reach the appropriate stage of development.
Fryxell, Gerald E; Lo, Carlos Wing-Hung; Chung, Shan Shan
2004-02-01
This study examines the motivations of mainland Chinese facilities in seeking ISO 14001 certification and examines the linkages between these motivations and self-reports of the effectiveness of major environmental management system (EMS) components. In a sample of 128 facilities in Beijing, Shanghai, and Guangzhou, the main drivers for certification were reported to be to ensure regulatory compliance, to enhance the firm's reputation, and to improve environmental performance, in that order. Although motivation to achieve cost reductions were least emphasized, a broad range of motivations appears to be considered in the decision to seek certification to ISO 14001. Regression models linking these motivations to the EMS components suggests that internal motivations have an influence on most EMS components. One interesting exception to this, however, is that no significant relationship was observed between internal motivations and the promulgation of environmental objectives and targets. The relationships associated with external motivations for certification (i.e., those in response to customer and other stakeholder pressures) and EMS components, on the other hand, are weaker and tend to occur earlier in the process cycle. No significant relationships were found between motivations to reduce costs and perceptions of the effectiveness of EMS components. Overall, these findings suggest that ISO 14001, as currently being implemented in mainland China, may have a modestly useful role when used in combination with other policy mechanisms to move the Chinese economy toward more sustainable practices. It is asserted that the ISO standard could provide even greater benefits if Chinese registrars were more proactive in developing EMS in conjunction with even more rigorous third-party audits. PMID:15285401
HAMP-Protocolo de Difus~ao em Grupo Para Redes Com Padr~oes de Mobilidade Heterogeneos
Rodrigues, LuÃs E.T.
~ao tipicamente baseadas em inundacÂ¸~ao (do Ingl^es, flooding) melhorada. Estas adaptam-se bem a alteracÂ¸~oes naÂ¸o em MANETs. A. Difus~ao N~ao Selectiva A difus~ao n~ao selectiva (do Ingl^es, broadcast) pode ser
Hanson, George
. 1 for monitoring a deck truss bridge: a layer of EM wave-guiding material is applied to steelInvestigation of strain-sensing materials based on EM surface wave propagation for steel bridge Available online 5 March 2011 Keywords: Electromagnetic surface wave Strain-sensing material Bridge Health
Chen, Jinsong
Joint inversion of seismic AVO and EM data for gas saturation estimation using a sampling- based of Mexico, is developed to demonstrate the benefits of joint inversion of seismic AVO and EM data. Results for determining rock physical and reservoir parameters, joint inversion of those data may have advantages over
Eizirik, Eduardo
, slbonatto@pucrs.br, Coordenador] Centro de Biologia Genômica e Molecular e Laboratório de Ornitologia MCT da pesquisas em colaboração com o Dr. Sandro L. Bonatto no Centro de Biologia Genômica e Molecular da PUCRS em sistemática molecular) (versão 0.9) Helena Mata helenamata@pucrs.br [Dr. Sandro L. Bonatto
ERIC Educational Resources Information Center
Adachi, Kohei
2013-01-01
Rubin and Thayer ("Psychometrika," 47:69-76, 1982) proposed the EM algorithm for exploratory and confirmatory maximum likelihood factor analysis. In this paper, we prove the following fact: the EM algorithm always gives a proper solution with positive unique variances and factor correlations with absolute values that do not exceed one, when the…
de Figueiredo, Luiz Henrique
Um sistema de cache preditivo para o processamento em tempo-real de grandes volumes de dados gr, 225, Rio de Janeiro, Brasil Abstract. Para visualizar objetos gr´aficos em tempo-real ´e necess´ario superar com dois tipos de problema: tempo limitado de para efetuar o processo de rendering e espa
Rotating-bed reactor as a power source for EM gun applications
Powell, J.; Botts, T.; Stickley, C.M.; Meth, S.
1980-01-01
Electromagnetic gun applications of the Rotating Bed Reactor (RBR) are examined. The RBR is a compact (approx. 1 m/sup 3/), (up to several thousand MW(th)), high-power reactor concept, capable of producing a high-temperature (up to approx. 300/sup 0/K) gas stream with a MHD generator coupled to it, the RBR can generate electric power (up to approx. 1000 MW(e)) in the pulsed or cw modes. Three EM gun applications are investigated: a rail gun thruster for orbit transfer, a rapid-fire EM gun for point defense, and a direct ground-to-space launch. The RBR appears suitable for all applications.
Not Available
1994-05-01
This document is one of several guidance documents developed to support the EM (DOE Environmental Restoration and Waste Management) Analytical Services program. Its purpose is to introduce assessment plates that can be used to conduct performance assessments of an organization`s or project`s ability to meet quality goals for analytical laboratory activities. These assessment plates are provided as non-prescriptive guidance to EM-support organizations responsible for collection of environmental data for remediation and waste management programs at DOE facilities. The assessments evaluate objectively all components of the analytical laboratory process to determine their proper selection and use.
Denoising of human speech using combined acoustic and em sensor signal processing
Ng, L C; Burnett, G C; Holzrichter, J F; Gable, T J
1999-11-29
Low Power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference. This greatly enhances the quality and quantify of information for many speech related applications. See Holzrichter, Burnett, Ng, and Lea, J. Acoustic. Soc. Am. 103 (1) 622 (1998). By using combined Glottal-EM- Sensor- and Acoustic-signals, segments of voiced, unvoiced, and no-speech can be reliably defined. Real-time Denoising filters can be constructed to remove noise from the user's corresponding speech signal.
In Situ Data Processing With Workflow-based Embedded Cyberinfrastructure (emCI)
NASA Astrophysics Data System (ADS)
Mehta, G.; Silva, F.; Graham, E. A.; Vahi, K.; Deelman, E.; Rundel, P.
2011-12-01
The decreasing cost of sensors and sensor networks has led to the wide scale adoption of this technology by large numbers of scientists for the collection of data in the field. At the same time, advances in both hardware and software have resulted in increased processing power at the sensor, enabling sensors in the field to do more than just data collection. With an increase in the number of sensors and deployments, scientists need tools for the configuration, operation, and debugging problems on their sensor networks. Furthermore, as the amount of data increases, scientists need a way to quickly and easily tag, process, archive, and share their datasets. Without proper tools, it is common for data processing to happen weeks or sometimes months after it is collected. This leads to important events being missed and makes real-time data analysis impossible. Additionally, because data is often manually processed through a series of repetitive steps, the analysis is susceptible to errors that are hard to track after data is combined and shared among researchers. Our emCI (embedded cyberinfrastructure) toolkit enables researchers to easily collect, analyze, and share their data. emCI provides a web-portal with upload/download capabilities that accept data in a number of different formats and ultimately can be used to archive data and share datasets among scientists. emCI uses an embedded general-purpose computer in the field for interfacing with sensors, coordinating data collection, and providing reliable data transfer to the emCI web portal. emCI relies on workflow technologies to automate data processing pipelines and to provide provenance information. In particular, emCI uses the Pegasus Workflow Management System as a core component, adapting it to the embedded computation environment. emCI allows scientists to distribute tasks among sensors in field and servers in the lab. In-situ processing using embedded workflows enable data reduction and validation in the field. Scientists can also create embedded workflows for data analysis and sensor retasking, allowing for much faster response to events in the field as well as disconnected operation from the emCI portal. Workflows executed at the emCI portal can include heavier computations, and combine data from multiple sensors by performing data analysis on data from multiple sources. The emCI portal also supports workflows for data transfers, visualization, and the automatic monitoring of the embedded infrastructure. We have prototyped the emCI toolkit in a project that uses automated digital cameras and weather stations for observing climate change based on plant phenology observations. In this application, embedded workflows are being used to coordinate the field data collection, reduce and analyze image data in the field, and retask cameras based on embedded triggers. We are currently in the process of moving our deployment from prototype to production stage at the Stunt Ranch UC Reserve in the Santa Monica Mountains.
Zeeman effect on surface electron transport in topological insulator Bi2Se3 nanoribbons
NASA Astrophysics Data System (ADS)
Wang, Li-Xian; Yan, Yuan; Zhang, Liang; Liao, Zhi-Min; Wu, Han-Chun; Yu, Da-Peng
2015-10-01
Topological insulators have exotic surface states that are massless Dirac fermions, manifesting special magnetotransport properties, such as the Aharonov-Bohm effect, Shubnikov-de Haas oscillations, and weak antilocalization effects. In the surface Dirac cone, the band structures are typically closely related to the p-orbitals and possess helical orbital texture. Here we report on the tunability of the transport properties via the interaction between the magnetic field and the spin-orbital angular momentum of the surface states in individual Bi2Se3 nanoribbons. Because the surface states have a large Landé factor and helical spin-orbital texture, the in-plane magnetic field induced Zeeman energy will result in the deformation of the Dirac cone, which gives rise to spin polarization of the surface states. The spin-dependent scattering of the conducting electrons on the existing local magnetic moments produces a giant negative magnetoresistance. The negative magnetoresistance is robust with a ratio of -20% at 2 K and -0.5% at 300 K under 14 T. The results are valuable for possible orbital-electronics based on topological insulators.Topological insulators have exotic surface states that are massless Dirac fermions, manifesting special magnetotransport properties, such as the Aharonov-Bohm effect, Shubnikov-de Haas oscillations, and weak antilocalization effects. In the surface Dirac cone, the band structures are typically closely related to the p-orbitals and possess helical orbital texture. Here we report on the tunability of the transport properties via the interaction between the magnetic field and the spin-orbital angular momentum of the surface states in individual Bi2Se3 nanoribbons. Because the surface states have a large Landé factor and helical spin-orbital texture, the in-plane magnetic field induced Zeeman energy will result in the deformation of the Dirac cone, which gives rise to spin polarization of the surface states. The spin-dependent scattering of the conducting electrons on the existing local magnetic moments produces a giant negative magnetoresistance. The negative magnetoresistance is robust with a ratio of -20% at 2 K and -0.5% at 300 K under 14 T. The results are valuable for possible orbital-electronics based on topological insulators. Electronic supplementary information (ESI) available: Additional transport properties. See DOI: 10.1039/c5nr05250e
NASA Astrophysics Data System (ADS)
Anandan, Jeeva S.; Safko, John L.
1995-02-01
The Table of Contents for the book is as follows: * Preface * 1. After-Banquet Talk in Honor of Aharonov's 60th Birthday * 2. Aharonov-Bohm Effect and Geometric Phases * Dynamic Observation of Flux Lines Based on the AB Effect Principle * Signs and Miracles of the Aharonov-Bohm Effect * Aharonov Effects for Two Slits and Separated Oscillatory Fields Interferences * Atom Interferometers * Faster than Fourier * Berry's Phase, Mesoscopic Conductivity and Local Forces * New Results in the Theory of Landau-Zener Transitions * Quantum Mechanics of the Electric Charge * Magnetic Charges and Local Duality Symmetry * 3. Gauge Fields in Condensed Matter * Quantum Phase in Action * Liberating Exotic Slaves * Persistent Currents in Normal Metals * 4. Black Holes and Quantum Gravity * Evidence for a Massive Black Hole in the Center of Our Galaxy * Black Holes, Wormholes, and the Disappearance of Global Charge * The Conflict Between Quantum Mechanics and General Relativity * Unitarity of the Black Hole Scattering Matrix * Entropy Generation in Quantum Gravity and Black Hole Remnants * Black Holes and Information Loss in 2D Dilaton Gravity * 5. Gravitation and Quantum Mechanics * Topological Phases and Their Duality in Electromagnetic and Gravitational Fields * Disordered Gravitation: Localization and Diffusion Limited Dynamics of the Early Universe * 6. Quantum Non-Locality and Geometry * The Superposition Principle in Multi-Particle Systems * Non-Locality and Objectivity in Quantum State Reduction * A Non-Polarization EPR Experiment: Observation of High-Visibility Franson Interference Fringes * Einstein-Podolsky-Rosen Correlations in Higher Dimensions * Time as a Derived Quantity in the Micromaser * Toward "It from Bit" * 7. Spin and Statistics * (Para)Bosons, (Para)Fermions, Quons and Other Beasts in the Menagerie of Particle Statistics * The Quantum Theory of Measurement and the Foundations of Statistical Mechanics * Time Reversal of Spin-Spin Couplings * Electromagnetic Velocity and Acceleration of Neutrons * 8. Quantum Reality and Phenomenology * A New Formulation of Quantum Mechanics * Measurement of Nonlocal Variables Without Breaking Causality * Quantum Anomalies and Three Families * Experiments Pursuant to Determining the Duration of Barrier Traversal in Quantum Tunneling * Global Quantization of Vacuum Angle and Magnetic Monopoles as a New Solution to the Strong CP Problem
Capitulo 4 Recordac~oes de Calculo Vetorial em Tr^es
Barata, JoÃ£o Carlos Alves
~oes. As identidades aqui listadas s~ao Â´uteis em diversas Â´areas da FÂ´isica, como no Eletromagnetismo e na Mec^anica dos Fluidos. Todos os resultados que aqui apresentamos podem ser formulados com mais eleg^ancia e
6. PHOTOCOPY, FOUNDATION AND FLOOR PLAN DRAWING OF E.M. BARRACKS, ...
6. PHOTOCOPY, FOUNDATION AND FLOOR PLAN DRAWING OF E.M. BARRACKS, N.C.O. AND OFFICERS QUARTERS. - NIKE Missile Base SL-40, Barracks No. 1, North end of base, southest of Basketball Court & northwest of Barracks No. 2, Hecker, Monroe County, IL
The Trier mummy Paï-es-tjau-em-aui-nu: radiological and histological findings.
Sigmund, G; Minas, M
2002-07-01
The ancient Egyptian mummy Paï-es-tjau-em-aui-nu, now on exhibition in the Rheinische Landesmuseum in Trier, Germany, was examined by conventional X-ray radiography, computed tomography, and digital fluoroscopy. In addition, some tissues were biopsied for further histologic identification. Along with some representative images, the peculiarities of the Trier mummy concerning the mummification process are presented. PMID:12111080
Data for Environmental Modeling (D4EM): Background and Applications of Data Automation
The Data for Environmental Modeling (D4EM) project demonstrates the development of a comprehensive set of open source software tools that overcome obstacles to accessing data needed by automating the process of populating model input data sets with environmental data available fr...
Injury risks of EMS responders: evidence from the National Fire Fighter Near-Miss Reporting System
Taylor, Jennifer A; Davis, Andrea L; Barnes, Brittany; Lacovara, Alicia V; Patel, Reema
2015-01-01
Objectives We analysed near-miss and injury events reported to the National Fire Fighter Near-Miss Reporting System (NFFNMRS) to investigate the workplace hazards and safety concerns of Emergency Medical Services (EMS) responders in the USA. Methods We reviewed 769 ‘non-fire emergency event’ reports from the NFFNMRS using a mixed methods approach. We identified 185 emergency medical calls and analysed their narrative text fields. We assigned Mechanism of Near-Miss/Injury and Nature of Injury codes and then tabulated frequencies (quantitative). We coded major themes regarding work hazards and safety concerns reported by the EMS responders (qualitative). Results Of the 185 emergency medical calls, the most commonly identified Mechanisms of Near-Miss/Injury to EMS responders was Assaults, followed by Struck-by Motor Vehicle, and Motor Vehicle Collision. The most commonly identified weapon used in an assault was a firearm. We identified 5 major domains of workplace hazards and safety concerns: Assaults by Patients, Risks from Motor Vehicles, Personal Protective Equipment, Relationships between Emergency Responders, and Policies, Procedures and Practices. Conclusions Narrative text from the NFFNMRS is a rich source of data that can be analysed quantitatively and qualitatively to provide insight into near-misses and injuries sustained by EMS responders. Near-miss reporting systems are critical components for occupational hazard surveillance. PMID:26068510
An incremental EM-based learning approach for on-line prediction of hospital
McLachlan, Geoff
An incremental EM-based learning approach for on-line prediction of hospital resource utilization, Brisbane, Qld 4072, Australia c School of Public Health, Curtin University of Technology, Perth, WA 6845-line prediction Summary Objective: Inpatient length of stay (LOS) is an important measure of hospital activity
Beyond EM-1: Lavas from Afanasy-Nikitin Rise and the Crozet Archipelago, Indian Ocean
Beyond EM-1: Lavas from Afanasy-Nikitin Rise and the Crozet Archipelago, Indian Ocean J. J. Mahoney, as well as high (87 Sr/86 Sr)t (to 0.7066). In contrast, young basalts from the Crozet Archipelago exhibit
Convergence results for the EM approach to mixtures of experts architectures \\Lambda
Jordan, Michael I.
Convergence results for the EM approach to mixtures of experts architectures \\Lambda Michael I. Jordan Lei Xu Department of Brain and Cognitive Sciences Massachusetts Institute of Technology Running Head: Convergence results for mixtures of experts *Address for correspondence: Michael I. Jordan, E10
EMS Newsletter June 2014 3 What made the exhibition unique from the beginning
Greuel, Gert-Martin
Editorial EMS Newsletter June 2014 3 What made the exhibition unique from the beginning is its reflected in the many positive comments left in the guest book: - This already beautiful exhibition that you can also use the program in the school. - A wonderful exhibition. I have spent much time here
Hirakawa, Keigo
. This unified empirical-Bayes based framework, therefore, offers a statistically principled and extremely-parameters via the marginal likelihood, that is, we adopt the empirical Bayes approach. One key benefitAN EMPIRICAL BAYES EM-WAVELET UNIFICATION FOR SIMULTANEOUS DENOISING, INTERPOLATION, AND
9th EMS Annual Meeting & 9th European Conference on Applications of Meteorology (ECAM)
Williams, Paul
9th EMS Annual Meeting & 9th European Conference on Applications of Meteorology (ECAM) 28 September Meteorological Society 9th Annual Meeting and the 9th European Conference on Applications of Meteorology at the UK Met Office. I am very grateful to the European Meteorological Society for enabling me to attend
Presence-only data and the EM algorithm T. Hastie,1
Hastie, Trevor
to as presence-only data. Our definition of the whole or full population refers to all sites in a region of locations sampled from the population, with unknown presences. We propose an EM algorithm to estimate in the naive model often used in practice. Finally, it is shown that the population prevalence of a species
An EM Algorithm for Maximum Likelihood Estimation of Process Factor Analysis Models
ERIC Educational Resources Information Center
Lee, Taehun
2010-01-01
In this dissertation, an Expectation-Maximization (EM) algorithm is developed and implemented to obtain maximum likelihood estimates of the parameters and the associated standard error estimates characterizing temporal flows for the latent variable time series following stationary vector ARMA processes, as well as the parameters defining the…
Tailored ML-EM Algorithm for Reconstruction of Truncated Projection Data using Few View-Angles
Mao, Yanfei; Zeng, Gengsheng L.
2013-01-01
Dedicated cardiac Single Photon Emission Computed Tomography (SPECT) systems have the advantage of high speed and sensitivity at no loss, or even a gain, in resolution. The potential drawbacks of these dedicated systems are data truncation by the small field of view (FOV) and the lack of view-angles. Serious artifacts, including streaks outside the FOV and distortion in the FOV, are introduced to the reconstruction when using the traditional emission data Maximum-Likelihood Expectation-Maximization (ML-EM) algorithm to reconstruct images from the truncated data at small number of views. In this paper, we propose a tailored ML-EM algorithm to suppress the artifacts caused by data truncation and insufficient angular sampling by reducing the image updating step sizes for the pixels outside the FOV. As a consequence, the convergence speed for the pixels outside the FOV is decelerated. We applied the proposed algorithm to truncated analytical data, Monte Carlo simulation data and real emission data at different numbers of views. The computer simulation results show that the tailored ML-EM algorithm outperforms the conventional ML-EM algorithm in terms of streak artifacts and distortion suppression for reconstruction from truncated projection data with a small number of views. PMID:23689102
Description and comparison of algorithms for correcting anisotropic magnification in cryo-EM images
Zhao, Jianhua; Benlekbir, Samir; Rubinstein, John L
2015-01-01
Single particle electron cryomicroscopy (cryo-EM) allows for structures of proteins and protein complexes to be determined from images of non-crystalline specimens. Cryo-EM data analysis requires electron microscope images of randomly oriented ice-embedded protein particles to be rotated and translated to allow for coherent averaging when calculating three-dimensional (3-D) structures. Rotation of 2-D images is usually done with the assumption that the magnification of the electron microscope is the same in all directions, a condition that has been found to be untrue with some electron microscopes when used with the settings necessary for cryo-EM with a direct detector device (DDD) camera (Grant and Grigorieff, in preparation). Correction of images by linear interpolation in real space has allowed high-resolution structures to be calculated from cryo-EM images for symmetric particles (Grant and Grigorieff, in preparation). Here we describe and compare a simple real space method and a somewhat more sophisticat...
Sanford, P.C.; Moe, M.A.; Hombach, W.G.; Urdangaray, R.
2013-07-01
The Department of Energy (DOE) Office of Environmental Management (EM) has developed a web-accessible database to collect actual cost data from completed EM projects to support cost estimating and analysis. This Environmental Cost Analysis System (ECAS) database was initially deployed in early 2009 containing the cost and parametric data from 77 decommissioning, restoration, and waste management projects completed under the Rocky Flats Closure Project. In subsequent years we have added many more projects to ECAS and now have a total of 280 projects from 8 major DOE sites. This data is now accessible to DOE users through a web-based reporting tool that allows users to tailor report outputs to meet their specific needs. We are using it as a principal resource supporting the EM Consolidated Business Center (EMCBC) and the EM Applied Cost Engineering (ACE) team cost estimating and analysis efforts across the country. The database has received Government Accountability Office review as supporting its recommended improvements in DOE's cost estimating process, as well as review from the DOE Office of Acquisition and Project Management (APM). Moving forward, the EMCBC has developed a Special Contract Requirement clause or 'H-Clause' to be included in all current and future EMCBC procurements identifying the process that contractors will follow to provide DOE their historical project data in a format compatible with ECAS. Changes to DOE O 413.3B implementation are also in progress to capture historical costs as part of the Critical Decision project closeout process. (authors)
DIVISO DINMICA EM ANEL DO CLCULO DO "RAY TRACING" DANIEL CMARA
de Figueiredo, Luiz Henrique
DIVISÃO DINÂMICA EM ANEL DO CÁLCULO DO "RAY TRACING" DANIEL CÂMARA ORIENTADOR PROF. ANDRÉ L. PIRES@inf.ufpr.br Abstract: Ray tracing is an algorithm to generate realistic images from three-dimensional scenes. The main goal of this paper is to give a parallel alternative to calculate the ray tracing, improving
DIVISO DINMICA EM ANEL DO CLCULO DO ``RAY TRACING'' DANIEL CMARA
de Figueiredo, Luiz Henrique
DIVISÃO DINÂMICA EM ANEL DO CÁLCULO DO ``RAY TRACING'' DANIEL CÂMARA ORIENTADOR PROF. ANDRÉ L@inf.ufpr.br Abstract: Ray tracing is an algorithm to generate realistic images from threedimensional scenes. The main goal of this paper is to give a parallel alternative to calculate the ray tracing, improving
www.energy.psu.edu The EMS Energy Institute at Penn State is a leading research
Lee, Dongwon
www.energy.psu.edu The EMS Energy Institute at Penn State is a leading research and development organization focused on energy science and engineering. We are committed to: -- Providing academic and technical leadership in the development and assessment of energy technologies, -- Providing Penn State
Biernacki, Christophe
Gaussian mixture models Christophe Biernacki UMR CNRS 6623 Â Universitâ??e de FrancheÂComtâ??e Gilles Celeux 1 sensible starting values for the EM algorithm to get maxiÂ mum likelihood parameter estimation in mixture in the context of multivariate Gaussian mixtures on the basis of numerical experiments on both simulated and real
Innovation on Energy Power Technology (17)Development of EMS/SCADA in TEPCO
NASA Astrophysics Data System (ADS)
Suzuki, Mamoru
Effective Load Dispatching Automatic Controller (ELDAC) is an EMS/SCADA system for Central Load Dispatching Office in Tokyo Electric Power Company Inc. This paper introduces the progress of development of ELDAC, which forecasts demand, sets up the most efficient generation schedule, and controls total power from generators.
Tanaka, E
1987-01-01
An efficient iterative reconstruction method for positron emission tomography (PET) is presented. The algorithm is basically an enhanced EM (expectation maximization) algorithm with improved frequency response. High-frequency components of the ratio of measured to calculated projections are extracted and are taken into account for the iterative correction of image density in such a way that the correction is performed with a uniform efficiency over the image plane and with a flat frequency response. As a result, the convergence speed is not so sensitive to the image pattern or matrix size as the standard EM algorithm, and nonuniformity of the spatial resolution is significantly improved. Nonnegativity of the reconstructed image is preserved. Simulation studies have been made assuming two PET systems: a scanning PET with ideal sampling and a stationary PET with sparse sampling. In the latter, a "bank array" of detectors is employed to improve the sampling in the object plane. The new algorithm provides satisfactory images by two or three iterations starting from a flat image in either case. The behavior of convergence is monitored by evaluating the root mean square of C(b)-1 where C(b) is the correction factor for pixel b in the EM algorithm. The value decreases rapidly and monotonically with iteration number. Although the theory is not accurate enough to assure the stability of convergence, the algorithm is promising to achieve significant saving in computation compared to the standard EM algorithm. PMID:18230435
EM WORKSHOP : AN INTERACTIVE TOOL TO BUILD WEB-BASED ELECTROMAGNETICS COURSES
Libre de Bruxelles, Université
, the development of interactive graphical interfaces on the Internet with Java is still a very tedious task-neutral development possibilities and high-performance and backward compatible (mostly with C and FORTRAN) codes. Java A software called EM Workshop has been developed to make easier the creation of interactive illustrations
Are you under stress in EMS. Understanding the slippery slope of burnout and PTSD.
Collopy, Kevin T; Kivlehan, Sean M; Snyder, Scott R
2012-10-01
Burnout and PTSD are closely linked and often underreported in EMS. EMS classrooms do little or nothing to prepare providers for the inherent emotional stresses of emergency response and the "thick skin" culture of EMS may make many providers apprehensive about sharing their true feelings. Burnout is triggered by many of the same stresses that lead to the symptoms of PTSD and providers experiencing burnout that doesn't resolve within a few weeks may actually be experiencing PTSD. Be mindful of yourself and your fellow coworkers, particularly after a very traumatic response. And remember traumatic responses don't need to be as dramatic as Sept. 11, New Orleans after Hurricane Katrina or the Aurora, CO shootings to bother an EMS worker. In contrast, these are the calls where providers often receive the most attention. Instead, watch for the new father who just performed CPR on an infant the same age as his own, or the provider who just watched his or her friend die following a motor vehicle collision. Pay attention to yourself and colleagues, and be responsible and honest with yourself and others about when coping strategies are enough, and when they aren't. Finally, don't ever be afraid to seek help. PMID:23097838
Memória fonológica em crianças bilíngues bimodais e crianças com implante coclear
de Quadros, Ronice Müller; Cruz, Carina Rebello; Pizzio, Aline Lemos
2014-01-01
RESUMO Este estudo comparou o desempenho de crianças bilíngues bimodais ouvintes (filhas de pais surdos) e crianças surdas usuárias de implante coclear (filhas de pais surdos e de pais ouvintes), com diferentes contextos de acesso à Língua Brasileira de Sinais (Libras), em tarefas que envolvem memória fonologica. Os testes utilizados foram: Teste de Pseudopalavras (Santos e Bueno, 2003) e Teste de Pseudosinais (desenvolvido pelos pesquisadores responsáveis pelo Projeto ‘Desenvolvimento Bilíngue Bimoda’). Além disso, foram incluídos dois grupos de controle, formados por crianças surdas (usuarias de Libras), e adultos bilíngues bimodais ouvintes. Na análise dos resultados, em relação ao desempenho entre os dois grupos testados foi constatado que o grupo de crianças bilíngues bimodais ouvintes apresentou desempenho superior, nos dois testes. No entanto, ao ser analisado o desempenho da criança surda usuaria de implante coclear, filha de pais surdos, que possui acesso irrestrito à Libras e comparado com o das crianças surdas usuárias de implante coclear, que possuem acesso restrito à Libras, foi constatado que o seu desempenho foi semelhante ao do grupo de crianças bilíngues bimodais ouvintes. As crianças surdas usuárias de implante coclear com acesso restrito à Libras e, portanto, com acesso maior ao Português apresentaram escores mais baixos nas tarefas, principalmente do teste em Português. Os resultados sugerem que as crianças surdas usuárias de implante coclear em processo de aquisição da línguagem podem se beneficiar com o acesso irrestrito à Libras, atingindo inclusive desempenho semelhante a de crianças bilíngues bimodais ouvintes. PMID:25110473
Review Article Abstract: Many plant species abort a large fraction of their em-
Klinkhamer, Peter
Review Article Abstract: Many plant species abort a large fraction of their em- bryos. It has often abort- ed. Such selective embryo abortion would lead to investment of resources only in the offspring with the highest potential fit- ness. Many studies have shown that otherwise viable embryos are aborted. However
ERIC Educational Resources Information Center
Rosinski, Jana; Lonsdale, Chelsea; Morrison, Becky; Mueller, Derek; Nannini, Adam
2013-01-01
"EM-Journal" is a flexibly refereed online journal featuring writing produced by students of Eastern Michigan University. The journal showcases a variety of documents (articles, essays, reports, etc.) written and designed by students enrolled in EMU's First-Year Writing (FYW) program, in selected Writing Intensive (WI) courses affiliated with the…
The Role of Journals in Building up Communities: The Experience of "Ciência em Tela"
ERIC Educational Resources Information Center
Martins, Isabel; de Souza Barros, Susana
2015-01-01
"Ciência em Tela" is an open access Brazilian science teacher education online journal that has been published twice a year since 2008 and which encourages the participation of professionals with different backgrounds and the submission of a variety of textual genres, besides research papers. Another feature is that the journal includes…
A Monte Carlo EM algorithm for de novo motif discovery in biomolecular sequences.
Bi, Chengpeng
2009-01-01
Motif discovery methods play pivotal roles in deciphering the genetic regulatory codes (i.e., motifs) in genomes as well as in locating conserved domains in protein sequences. The Expectation Maximization (EM) algorithm is one of the most popular methods used in de novo motif discovery. Based on the position weight matrix (PWM) updating technique, this paper presents a Monte Carlo version of the EM motif-finding algorithm that carries out stochastic sampling in local alignment space to overcome the conventional EM's main drawback of being trapped in a local optimum. The newly implemented algorithm is named as Monte Carlo EM Motif Discovery Algorithm (MCEMDA). MCEMDA starts from an initial model, and then it iteratively performs Monte Carlo simulation and parameter update until convergence. A log-likelihood profiling technique together with the top-k strategy is introduced to cope with the phase shifts and multiple modal issues in motif discovery problem. A novel grouping motif alignment (GMA) algorithm is designed to select motifs by clustering a population of candidate local alignments and successfully applied to subtle motif discovery. MCEMDA compares favorably to other popular PWM-based and word enumerative motif algorithms tested using simulated (l, d)-motif cases, documented prokaryotic, and eukaryotic DNA motif sequences. Finally, MCEMDA is applied to detect large blocks of conserved domains using protein benchmarks and exhibits its excellent capacity while compared with other multiple sequence alignment methods. PMID:19644166
PUBLICATIONS 1. "Spin-glass and ferromagnetic states in amorphous solids", with E.M. Chudnovsky,
Serota, Rostislav
of mesoscopic effects," Solid State Commun. 84, 843 (1992). 27. *"Orbital magnetism of mesoscopic metals: beyond, Phys. Rev. B (Rap. Comm.) 26, 2697 (1982). 2. "Phenomenological theory of amorphous magnets with small random anisotropy", with E.M. Chudnovsky, J. Phys. C16, 4181 (1984). 3. "Magnetic properties of solids
Instituto de Cincias Exatas COLEGIADO DO CURSO DE GRADUAO EM MATEMTICA
Procacci, Aldo
Instituto de Ciências Exatas COLEGIADO DO CURSO DE GRADUAÇÃO EM MATEMÁTICA 3º andar sala 3107 Fone: (031) 3409.5987 Unidade: INSTITUTO DE CIÊNCIAS EXATAS Curso: MATEMÁTICA Turno: DIURNO Graduação Licenciatura 2011038060 Professor Seme Gebara Neto Coordenador do Colegiado do Curso de Graduação
Ministrio quer matricular 5 mil alunos por ano em cursos curtos
Instituto de Sistemas e Robotica
Ministério quer matricular 5 mil alunos por ano em cursos curtos Ensino superior. Cursos de dois) estima que os novos cursos superiores especializados (CES), de curta duração, "possam ter uma procura de - o investimento nestes cursos de- verá ser da ordem dos 15, 7 mi- lhões de euros, no primeiro ano
CATLOGO DO CURSO DE PS-GRADUAO EM ASTROFSICA Coordenador Acadmico
CATÁLOGO DO CURSO DE PÓS-GRADUAÇÃO EM ASTROFÍSICA Coordenador Acadêmico Cláudia Vilega Rodrigues Conselho de curso André de Castro Milone Cláudia Vilega Rodrigues José Carlos Neves de Araújo Odylio Denys DISCIPLINAS DO CURSO DE ASTROFÍSICA OBRIGATÓRIAS AST-200-3 Evolução Estelar I Pré-requisitos: não há
(continuao das responsabilidades) um estudo em que voc talvez se inscreva, possvel
(continuação das responsabilidades) um estudo em que você talvez se inscreva, é possível também que(locais) do estudo. · Seguir as instruções dos pesquisadores. · Certificar-se de que suas informações sobre passado/presente, se for relevante para o estudo. · Buscar a assistência à saúde para qualquer problema
Universidade de Braslia Instituto de Cincias Humanas Programa de Ps-Graduao em Histria
Maier, Rudolf Richard
/ Identidades, Tradições e Processos 12 4 História Social/ Sociedade, Instituições e Poder 25 16 Vagas para Processos 01 01 História Social/ Sociedade, Instituições e Poder 01 01 3. DA INSCRIÇÃO NO PROCESSO SELETIVOUniversidade de Brasília Instituto de Ciências Humanas Programa de Pós-Graduação em História
Colaborao em Ambientes Heterogneos de Realidade Virtual para Aplicaes de Treinamento
Barbosa, Alberto
, Experimentation, Human Factors. Keywords Collaboration, Immersive Environments, CAVE, Virtual Reality, HumanColaboração em Ambientes Heterogêneos de Realidade Virtual para Aplicações de Treinamento Eduardo R@inf.puc-rio.br ABSTRACT Over the years, many studies have explored the potential of virtual reality technologies
Quantitative comparison of FBP, EM, and Bayesian reconstruction algorithms for the IndyPET scanner.
Frese, Thomas; Rouze, Ned C; Bouman, Charles A; Sauer, Ken; Hutchins, Gary D
2003-02-01
We quantitatively compare filtered backprojection (FBP), expectation-maximization (EM), and Bayesian reconstruction algorithms as applied to the IndyPET scanner--a dedicated research scanner which has been developed for small and intermediate field of view imaging applications. In contrast to previous approaches that rely on Monte Carlo simulations, a key feature of our investigation is the use of an empirical system kernel determined from scans of line source phantoms. This kernel is incorporated into the forward model of the EM and Bayesian algorithms to achieve resolution recovery. Three data sets are used, data collected on the IndyPET scanner using a bar phantom and a Hoffman three-dimensional brain phantom, and simulated data containing a hot lesion added to a uniform background. Reconstruction quality is analyzed quantitatively in terms of bias-variance measures (bar phantom) and mean square error (lesion phantom). We observe that without use of the empirical system kernel, the FBP, EM, and Bayesian algorithms give similar performance. However, with the inclusion of the empirical kernel, the iterative algorithms provide superior reconstructions compared with FBP, both in terms of visual quality and quantitative measures. Furthermore, Bayesian methods outperform EM. We conclude that significant improvements in reconstruction quality can be realized by combining accurate models of the system response with Bayesian reconstruction algorithms. PMID:12716002
What is color for? Light is E-M radiation of different frequencies.
Jacobs, David
is E-M radiation of different frequencies. Superposition principle · Perception 3 cones -> 3D color negative response · In general, any three colors projected onto this space span it. But not with non will produce a wide variety of RGB values, depending on the light. · Separate color of materials from color
Deteco de Ativao em Ressonncia Nuclear Magntica Funcional do Crebro PEDRO PAULO DE M. OLIVEIRA JR
de Figueiredo, Luiz Henrique
images collected with a 1,5 Tesla MRI Scanner. Results, also presented here, indicate the feasibility de sinal em exames funcionais é da ordem de 5%, num aparelho de 1.5 Tesla. Isto #12;significa que Philips de 1,5 Tesla cujo software proprietário da Philips
Barbosa, Alberto
122 Novas estratégias comunicativas como fator de qualidade na interação de surdos em um sistema formulário web e verificar se o uso de novas estratégias comunicativas melhora a interação dos surdos. Foram (MAC), uma com a interface original do sistema, e outra com o uso de novas estratégias comunicativas
Iterative Procrustes alignment with the EM algorithm B. Luoa,b,*, E.R. Hancocka
Hancock, Edwin
Iterative Procrustes alignment with the EM algorithm B. Luoa,b,*, E.R. Hancocka a Department December 2001 Abstract This paper casts the problem of point-set alignment via Procrustes analysis of the Procrustes alignment to noise and clutter. By constructing a Gaussian mixture model over the missing
Carvalho, João Luiz
FADIGA MUSCULAR POR MEIO DE ELETROMIOGRAFIA DE SUPERFÍCIE DE ALTA DENSIDADE G. M. Q. Mendonça1 , F. A fadiga muscular, por meio de mapas topológicos (no plano espacial) e regressão linear (no eixo do tempo trabalho propõe a avaliação da fatigabilidade em três momentos -- início, meio e fim -- do esforço. Esta
Gaze-Augmented Manual Interaction This project will demonstrate a new approach to em-
Reiterer, Harald
Gaze-Augmented Manual Interaction Abstract This project will demonstrate a new approach to em- ploying users' gaze in the context of human-computer interaction. This new approach uses gaze passively in order to improve the speed and precision of manually controlled pointing techniques. Designing such gaze
Molecular interactions in rotavirus assembly and uncoating seen by high-resolution cryo-EM
Harrison, Stephen C.
Molecular interactions in rotavirus assembly and uncoating seen by high-resolution cryo-EM James Z, April 11, 2009 (sent for review March 19, 2009) Rotaviruses, major causes of childhood gastroenteritis cryomicroscopy and single-particle recon- struction, we have visualized a rotavirus particle comprising the inner
ICE-EM RNSA 2007 Workshop on Pairing Based Cryptography 1 Certificateless Cryptography I
Paterson, Kenny
ICE-EM RNSA 2007 Workshop on Pairing Based Cryptography 1 Certificateless Cryptography I Kenny on Pairing Based Cryptography 2 Overview This talk and the next: Â· Motivating and introducing certificateless (public key) cryptography Â· Certificateless Encryption (CLE) and its security Â· Specific and generic
Teorias de Gauge e Conex~oes em Fibrados Vectoriais 1 Relatividade e Electromagnetismo
NatÃ¡rio, JosÃ©
Teorias de Gauge e Conex~oes em Fibrados Vectoriais 1 Relatividade e Electromagnetismo A Teoria da Relatividade Especial identifica o espaÂ¸co-tempo com R4 (com coordenadas Cartesianas (x0, x1, x2, x3) = (t, x
Suporte `a computac~ao orientada aos grupos em sistemas distribuidos tolerantes a faltas
Rodrigues, Luís E.T.
¸ ~ao em grupo de modo eficiente sobre este tipo de infra-estrutura, prop ~oe-se uma arquitectura hier¸ ~ao destas tecnologias, a dissertac¸ ~ao sugere uma arquitectura gen´erica para su- portar interacc estar replicados. Esta arquitectura permite suportar de um modo integrado diversos protocolos de gest
NASA Astrophysics Data System (ADS)
Tavares, E. T., Jr.; Klafke, J. C.
2003-08-01
O presente trabalho propõe-se a resgatar uma experiência que teve lugar no Planetário de São Paulo nos anos 60. Em 1962, o Sr. Acácio, então com 37 anos, deficiente visual desde os 27, passou a assistir às aulas ministradas pelo Prof. Aristóteles Orsini aos integrantes do corpo de servidores do Planetário. O Sr. Acácio era o único deficiente da turma e, embora possuísse conhecimentos básicos e relativamente avançados de matemática, enfrentava dificuldades na compreensão e acompanhamento da exposição, como também em estudos posteriores. Com o intuito de auxiliá-lo na superação desses problemas, o Prof. Orsini solicitou a construção de modelos mecânicos que, através do sentido do tato, permitissem o acompanhamento das aulas e a transposição do modelo para o "constructo" mental. Essa prática mostrou-se tão eficaz que facilitou sobejamente o aprendizado da matéria pelo sujeito. O Sr. Acácio passou a integrar o corpo de professores do Planetário/Escola Municipal de Astrofísica, tendo ficado responsável pelo curso de "Introdução à Astronomia" por vários anos. Além disso, a experiência foi tão bem sucedida que alguns dos modelos tiveram seus elementos constitutivos pintados diferencialmente para serem utilizados em cursos regulares do Planetário, tornando-se parte integrante do conjunto de recursos didáticos da instituição. É pensando nessa eficácia, tanto em seu objetivo original permitir o aprendizado de um deficiente visual quanto no subsidiário recurso didático sistemático da instituição que decidimos resgatar essa experiência. Estribados nela, acreditamos ser extremamente produtivo, em termos educacionais, o aperfeiçoamento dos modelos originais, agora resgatados e restaurados, e a criação de outros que pudessem ser utilizados no ensino dessa ciência a deficientes visuais.
Microstructure Effect on EM-induced Degradations in Dual-Inlaid Copper Interconnects
NASA Astrophysics Data System (ADS)
Kteyan, A.; Sukharev, V.; Meyer, M.-A.; Zschech, E.; Nix, W. D.
2007-10-01
A novel physical model and a simulation algorithm are used to predict EM induced stress evolution in dual-inlaid copper interconnects. The aim of the current simulation was to investigate the dual effect of the microstructure, which consists of (a) the effect of GBs as the sources/sinks for vacancies and plated atoms and as the channel for vacancy migration, and (b) the effect of texture-related variations of the modulus of elasticity on the stress evolution in copper lines caused by EM. The major difference between our approach and the previously described ones is the accounting of additional stress generated by the plated atoms. As it is shown this stress plays an important role in the vacancy equilibration. The results of the numerical simulation have been proven experimentally by EM degradation studies on fully embedded dual-inlaid copper interconnect test structures and by subsequent microstructure analysis, mainly based on electron backscatter diffraction (EBSD) data. The virtual EM-induced void formation, movement and growth in a copper interconnect were continuously monitored in an in-situ scanning electron microscopy (SEM) experiment. The copper microstructure, particularly the orientation of grains and grain boundaries, was determined with EBSD. It has a significant influence on grain boundary diffusivity and on stress evolution. For interconnects with interfaces that resist atomic transport and where grain boundaries are the important pathways for atom migration, degradation and failure processes are completely different for microstructures with randomly oriented grain boundaries compared with "bamboo-like" microstructures. The correspondence between simulation results and experimental data indicates the applicability of the developed model for optimization of the physical and electrical design rules. Simulation-based optimization of the interconnect architecture, segment geometry, material properties and some of the process parameters can produce on-chip interconnect systems with a high immunity to EM-induced failures.
Not Available
1994-05-01
This document is one of several guidance documents developed by the US Department of Energy (DOE) Office of Environmental Restoration and Waste Management (EM). These documents support the EM Analytical Services Program (ASP) and are based on applicable regulatory requirements and DOE Orders. They address requirements in DOE Orders by providing guidance that pertains specifically to environmental restoration and waste management sampling and analysis activities. DOE 5700.6C Quality Assurance (QA) defines policy and requirements to establish QA programs ensuring that risks and environmental impacts are minimized and that safety, reliability, and performance are maximized. This is accomplished through the application of effective management systems commensurate with the risks imposed by the facility and the project. Every organization supporting EM`s environmental sampling and analysis activities must develop and document a QA program. Management of each organization is responsible for appropriate QA program implementation, assessment, and improvement. The collection of credible and cost-effective environmental data is critical to the long-term success of remedial and waste management actions performed at DOE facilities. Only well established and management supported assessment programs within each EM-support organization will enable DOE to demonstrate data quality. The purpose of this series of documents is to offer specific guidance for establishing an effective assessment program for EM`s environmental sampling and analysis (ESA) activities.
Hostler, David; Thomas, Elizabeth G; Emerson, Scott S; Christenson, James; Stiell, Ian G; Rittenberger, Jon C; Gorman, Kyle R; Bigham, Blair L; Callaway, Clifton W; Vilke, Gary M; Beaudoin, Tammy; Cheskes, Sheldon; Craig, Alan; Davis, Daniel P; Reed, Andrew; Idris, Ahamed; Nichol, Graham
2010-01-01
Summary Background Out of hospital cardiac arrest (OHCA) is common and lethal. It has been suggested that OHCA witnessed by EMS providers is a predictor of survival because advanced help is immediately available. We examined EMS witnessed OHCA from the Resuscitation Outcomes Consortium (ROC) to determine the effect of EMS witnessed vs. bystander witnessed and unwitnessed OHCA. Methods Data were analyzed from a prospective, population-based cohort study in 10 U.S. and Canadian ROC sites. Individuals with non-traumatic OHCA treated 04/01/06 – 03/31/07 by EMS providers with defibrillation or chest compressions were included. Cases were grouped into EMS-witnessed, bystander witnessed, and unwitnessed and further stratified for bystander CPR. Multiple logistic regressions evaluated the odds ratio (OR) for survival to discharge relative to the EMS-witnessed group after adjusting for age, sex, public/private location of collapse, ROC site, and initial ECG rhythm. Of 9,991 OHCA, 1022 (10.2%) of EMS-witnessed, 3,369 (33.7%) bystander witnessed, and 5,600 (56.1%) unwitnessed. Results The most common initial rhythm in the EMS-witnessed group was PEA which was higher than in the bystander- and unwitnessed groups (p<0.001). The adjusted OR (95% CI) of survival compared to the EMS-witnessed group was 0.41, (0.36, 0.46) in bystander witnessed with bystander CPR, 0.37, (0.33, 0.43) in bystander witnessed without bystander CPR, 0.17 (0.14, 0.20) in unwitnessed with bystander CPR and 0.21 (0.18, 0.24) in unwitnessed cases without bystander CPR. Conclusions Immediate application of prehospital care for OHCA may improve survival. Efforts should be made to educate patients to access 9-1-1 for prodromal symptoms. PMID:20403656
Stadelmann, Britta; Spiliotis, Markus; Müller, Joachim; Scholl, Sabrina; Müller, Norbert; Gottstein, Bruno; Hemphill, Andrew
2010-11-01
In Echinococcus multilocularis metacestodes, the surface-associated and highly glycosylated laminated layer, and molecules associated with this structure, is believed to be involved in modulating the host-parasite interface. We report on the molecular and functional characterisation of E. multilocularis phosphoglucose isomerase (EmPGI), which is a component of this laminated layer. The EmPGI amino acid sequence is virtually identical to that of its homologue in Echinococcus granulosus, and shares 64% identity and 86% similarity with human PGI. Mammalian PGI is a multi-functional protein which, besides its glycolytic function, can also act as a cytokine, growth factor and inducer of angiogenesis, and plays a role in tumour growth, development and metastasis formation. Recombinant EmPGI (recEmPGI) is also functionally active as a glycolytic enzyme and was found to be present, besides the laminated layer, in vesicle fluid and in germinal layer cell extracts. EmPGI is released from metacestodes and induces a humoral immune response in experimentally infected mice, and vaccination of mice with recEmPGI renders these mice more resistant towards secondary challenge infection, indicating that EmPGI plays an important role in parasite development and/or in modulating the host-parasite relationship. We show that recEmPGI stimulates the growth of isolated E. multilocularis germinal layer cells in vitro and selectively stimulates the proliferation of bovine adrenal cortex endothelial cells but not of human fibroblasts and rat hepatocytes. Thus, besides its role in glycolysis, EmPGI could also act as a factor that stimulates parasite growth and potentially induces the formation of novel blood vessels around the developing metacestode in vivo. PMID:20600070