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Sample records for microscopic two-level system

  1. Rapid characterization of microscopic two-level systems using Landau-Zener transitions in a superconducting qubit

    International Nuclear Information System (INIS)

    Tan, Xinsheng; Yu, Haifeng; Yu, Yang; Han, Siyuan

    2015-01-01

    We demonstrate a fast method to detect microscopic two-level systems in a superconducting phase qubit. By monitoring the population leak after sweeping the qubit bias flux, we are able to measure the two-level systems that are coupled with the qubit. Compared with the traditional method that detects two-level systems by energy spectroscopy, our method is faster and more sensitive. This method supplies a useful tool to investigate two-level systems in solid-state qubits

  2. Quasiparticle-induced decoherence of microscopic two-level-systems in superconducting qubits

    Energy Technology Data Exchange (ETDEWEB)

    Bilmes, Alexander; Lisenfeld, Juergen; Zanker, Sebastian; Weiss, Georg; Ustinov, Alexey V. [PHI, KIT, Karlsruhe (Germany); Marthaler, Michael; Schoen, Gerd [TFP, KIT, Karlsruhe (Germany)

    2016-07-01

    Parasitic Two-Level-Systems (TLS) are one of the main sources of decoherence in superconducting nano-scale devices such as SQUIDs, resonators and quantum bits (qubits), although the TLS' microscopic nature remains unclear. We use a superconducting phase qubit to detect TLS contained within the tunnel barrier of the qubit's Al/AlOx/Al Josephson junction. If the TLS transition frequency lies within the 6-10 GHz range, we can coherently drive it by resonant microwave pulses and access its quantum state by utilizing the strong coupling to the qubit. Our previous measurements of TLS coherence in dependence of the temperature indicate that quasiparticles (QPs), which diffuse from the superconducting Al electrodes into the oxide layer, may give rise to TLS energy loss and dephasing. Here, we probe the TLS-QP interaction using a reliable method of in-situ QP injection via an on-chip dc-SQUID that is pulse-biased beyond its switching current. The QP density is calibrated by measuring associated characteristic changes to the qubit's energy relaxation rate. We will present experimental data which show the QP-induced TLS decoherence in good agreement to theoretical predictions.

  3. Darboux transformation for two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.; Baldiotti, M.; Gitman, D.; Shamshutdinova, V. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil)

    2005-06-01

    We develop the Darboux procedure for the case of the two-level system. In particular, it is demonstrated that one can construct the Darboux intertwining operator that does not violate the specific structure of the equations of the two-level system, transforming only one real potential into another real potential. We apply the obtained Darboux transformation to known exact solutions of the two-level system. Thus, we find three classes of new solutions for the two-level system and the corresponding new potentials that allow such solutions. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  4. Two-level tunneling systems in amorphous alumina

    Science.gov (United States)

    Lebedeva, Irina V.; Paz, Alejandro P.; Tokatly, Ilya V.; Rubio, Angel

    2014-03-01

    The decades of research on thermal properties of amorphous solids at temperatures below 1 K suggest that their anomalous behaviour can be related to quantum mechanical tunneling of atoms between two nearly equivalent states that can be described as a two-level system (TLS). This theory is also supported by recent studies on microwave spectroscopy of superconducting qubits. However, the microscopic nature of the TLS remains unknown. To identify structural motifs for TLSs in amorphous alumina we have performed extensive classical molecular dynamics simulations. Several bistable motifs with only one or two atoms jumping by considerable distance ~ 0.5 Å were found at T=25 K. Accounting for the surrounding environment relaxation was shown to be important up to distances ~ 7 Å. The energy asymmetry and barrier for the detected motifs lied in the ranges 0.5 - 2 meV and 4 - 15 meV, respectively, while their density was about 1 motif per 10 000 atoms. Tuning of motif asymmetry by strain was demonstrated with the coupling coefficient below 1 eV. The tunnel splitting for the symmetrized motifs was estimated on the order of 0.1 meV. The discovered motifs are in good agreement with the available experimental data. The financial support from the Marie Curie Fellowship PIIF-GA-2012-326435 (RespSpatDisp) is gratefully acknowledged.

  5. Experimental Hamiltonian identification for controlled two-level systems

    International Nuclear Information System (INIS)

    Schirmer, S.G.; Kolli, A.; Oi, D.K.L.

    2004-01-01

    We present a strategy to empirically determine the internal and control Hamiltonians for an unknown two-level system (black box) subject to various (piecewise constant) control fields when direct readout by measurement is limited to a single, fixed observable

  6. Stationary states of two-level open quantum systems

    International Nuclear Information System (INIS)

    Gardas, Bartlomiej; Puchala, Zbigniew

    2011-01-01

    A problem of finding stationary states of open quantum systems is addressed. We focus our attention on a generic type of open system: a qubit coupled to its environment. We apply the theory of block operator matrices and find stationary states of two-level open quantum systems under certain conditions applied on both the qubit and the surrounding.

  7. The geometric phase in two-level atomic systems

    International Nuclear Information System (INIS)

    Tian Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Randall Babbitt, Wm.

    2004-01-01

    We report the observation of the geometric phase in a closed two-level atomic system using stimulated photon echoes. The two-level system studied consists of the two-electronic energy levels ( 3 H 4 and 3 H 6 ) of Tm 3+ doped in YAG crystal. When a two-level atom at an arbitrary superposition state is excited by a pair of specially designed laser pulses, the excited state component gains a relative phase with respect to the ground state component. We identified the phase shift to be of pure geometric nature. The dynamic phase associated to the driving Hamiltonian is unchanged. The experiment results of the phase change agree with the theory to the extent of the measurement limit

  8. Mixing phases of unstable two-level systems

    International Nuclear Information System (INIS)

    Sokolov, V.V.; Brentano, P. von.

    1993-01-01

    An unstable two-level system decaying into an arbitrary number of channels is considered. It is shown that the mixing phases of the two overlapping resonances can be expressed in the terms of their partial widths and one additional universal mixing parameter. Some applications to a doublet of 2 + resonances in 8 Be and to the ρ-ω systems are considered. 18 refs

  9. Two-level systems driven by large-amplitude fields

    Science.gov (United States)

    Nori, F.; Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.

    2009-03-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition, (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems. S. Ashhab, J.R. Johansson, A.M. Zagoskin, F. Nori, Two-level systems driven by large-amplitude fields, Phys. Rev. A 75, 063414 (2007). S. Ashhab et al, unpublished.

  10. Perturbation Theory for Open Two-Level Nonlinear Quantum Systems

    International Nuclear Information System (INIS)

    Zhang Zhijie; Jiang Dongguang; Wang Wei

    2011-01-01

    Perturbation theory is an important tool in quantum mechanics. In this paper, we extend the traditional perturbation theory to open nonlinear two-level systems, treating decoherence parameter γ as a perturbation. By this virtue, we give a perturbative solution to the master equation, which describes a nonlinear open quantum system. The results show that for small decoherence rate γ, the ratio of the nonlinear rate C to the tunneling coefficient V (i.e., r = C/V) determines the validity of the perturbation theory. For small ratio r, the perturbation theory is valid, otherwise it yields wrong results. (general)

  11. Two-level systems driven by large-amplitude fields

    International Nuclear Information System (INIS)

    Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.; Nori, Franco

    2007-01-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems

  12. Atomistic study of two-level systems in amorphous silica

    Science.gov (United States)

    Damart, T.; Rodney, D.

    2018-01-01

    Internal friction is analyzed in an atomic-scale model of amorphous silica. The potential energy landscape of more than 100 glasses is explored to identify a sample of about 700 two-level systems (TLSs). We discuss the properties of TLSs, particularly their energy asymmetry and barrier as well as their deformation potential, computed as longitudinal and transverse averages of the full deformation potential tensors. The discrete sampling is used to predict dissipation in the classical regime. Comparison with experimental data shows a better agreement with poorly relaxed thin films than well relaxed vitreous silica, as expected from the large quench rates used to produce numerical glasses. The TLSs are categorized in three types that are shown to affect dissipation in different temperature ranges. The sampling is also used to discuss critically the usual approximations employed in the literature to represent the statistical properties of TLSs.

  13. Franson Interference Generated by a Two-Level System

    Science.gov (United States)

    Peiris, M.; Konthasinghe, K.; Muller, A.

    2017-01-01

    We report a Franson interferometry experiment based on correlated photon pairs generated via frequency-filtered scattered light from a near-resonantly driven two-level semiconductor quantum dot. In contrast to spontaneous parametric down-conversion and four-wave mixing, this approach can produce single pairs of correlated photons. We have measured a Franson visibility as high as 66%, which goes beyond the classical limit of 50% and approaches the limit of violation of Bell's inequalities (70.7%).

  14. Thimble microscope system

    Science.gov (United States)

    Kamal, Tahseen; Rubinstein, Jaden; Watkins, Rachel; Cen, Zijian; Kong, Gary; Lee, W. M.

    2016-12-01

    Wearable computing devices, e.g. Google Glass, Smart watch, embodies the new human design frontier, where technology interfaces seamlessly with human gestures. During examination of any subject in the field (clinic, surgery, agriculture, field survey, water collection), our sensory peripherals (touch and vision) often go hand-in-hand. The sensitivity and maneuverability of the human fingers are guided with tight distribution of biological nerve cells, which perform fine motor manipulation over a range of complex surfaces that is often out of sight. Our sight (or naked vision), on the other hand, is generally restricted to line of sight that is ill-suited to view around corner. Hence, conventional imaging methods are often resort to complex light guide designs (periscope, endoscopes etc) to navigate over obstructed surfaces. Using modular design strategies, we constructed a prototype miniature microscope system that is incorporated onto a wearable fixture (thimble). This unique platform allows users to maneuver around a sample and take high resolution microscopic images. In this paper, we provide an exposition of methods to achieve a thimble microscopy; microscope lens fabrication, thimble design, integration of miniature camera and liquid crystal display.

  15. Excitation transfer in two two-level systems coupled to an oscillator

    International Nuclear Information System (INIS)

    Hagelstein, P L; Chaudhary, I U

    2008-01-01

    We consider a generalization of the spin-boson model in which two different two-level systems are coupled to an oscillator, under conditions where the oscillator energy is much less than the two-level system energies, and where the oscillator is highly excited. We find that the two-level system transition energy is shifted, producing a Bloch-Siegert shift in each two-level system similar to what would be obtained if the other were absent. At resonances associated with energy exchange between a two-level system and the oscillator, the level splitting is about the same as would be obtained in the spin-boson model at a Bloch-Siegert resonance. However, there occur resonances associated with the transfer of excitation between one two-level system and the other, an effect not present in the spin-boson model. We use a unitary transformation leading to a rotated system in which terms responsible for the shift and splittings can be identified. The level splittings at the anticrossings associated with both energy exchange and excitation transfer resonances are accounted for with simple two-state models and degenerate perturbation theory using operators that appear in the rotated Hamiltonian

  16. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  17. Resonant retuning of Rabi oscillations in a two-level system

    International Nuclear Information System (INIS)

    Leonov, A.V.; Feranchuk, I.D.

    2009-01-01

    The evolution of a two-level system in a single-mode quantum field is considered beyond the rotating wave approximation. The existence of quasi-degenerate energy levels is shown to influence the essential characteristics of temporal and amplitude Rabi oscillations of the system in a resonant manner. (authors)

  18. Excitation of graphene plasmons as an analogy with the two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiahui [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Lv, Bo, E-mail: lb19840313@126.com [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Li, Rujiang [College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Ma, Ruyu; Chen, Wan; Meng, Fanyi [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China)

    2016-02-15

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  19. Excitation of graphene plasmons as an analogy with the two-level system

    International Nuclear Information System (INIS)

    Fu, Jiahui; Lv, Bo; Li, Rujiang; Ma, Ruyu; Chen, Wan; Meng, Fanyi

    2016-01-01

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  20. Exact Solution of the Two-Level System and the Einstein Solid in the Microcanonical Formalism

    Science.gov (United States)

    Bertoldi, Dalia S.; Bringa, Eduardo M.; Miranda, E. N.

    2011-01-01

    The two-level system and the Einstein model of a crystalline solid are taught in every course of statistical mechanics and they are solved in the microcanonical formalism because the number of accessible microstates can be easily evaluated. However, their solutions are usually presented using the Stirling approximation to deal with factorials. In…

  1. Crossing rule for a PT-symmetric two-level time-periodic system

    International Nuclear Information System (INIS)

    Moiseyev, Nimrod

    2011-01-01

    For a two-level system in a time-periodic field we show that in the non-Hermitian PT case the level crossing is of two quasistationary states that have the same dynamical symmetry property. At the field's parameters where the two levels which have the same dynamical symmetry cross, the corresponding quasienergy states coalesce and a self-orthogonal state is obtained. This situation is very different from the Hermitian case where a crossing of two quasienergy levels happens only when the corresponding two quasistationary states have different dynamical symmetry properties and, unlike the situation in the non-Hermitian case, the spectrum remains complete also when the two levels cross.

  2. Non-zero temperature two-mode squeezing for time-dependent two-level systems

    International Nuclear Information System (INIS)

    Aliaga, J.; Gruver, J.L.; Proto, A.N.; Cerdeira, H.A.

    1994-01-01

    A Maximum Entropy Principle density matrix method, valid for systems with temperature different from zero, is presented making it possible two-mode squeezed states in two-level systems with relevant operators and Hamiltonian connected with O(3,2). A method which allows one to relate the appearance of squeezing to the relevant operators, included in order to define the density matrix of the system is given. (author). 14 refs, 1 fig

  3. The simulation of the non-Markovian behaviour of a two-level system

    Science.gov (United States)

    Semina, I.; Petruccione, F.

    2016-05-01

    Non-Markovian relaxation dynamics of a two-level system is studied with the help of the non-linear stochastic Schrödinger equation with coloured Ornstein-Uhlenbeck noise. This stochastic Schrödinger equation is investigated numerically with an adapted Platen scheme. It is shown, that the memory effects have a significant impact to the dynamics of the system.

  4. Minimum time control of a pair of two-level quantum systems with opposite drifts

    International Nuclear Information System (INIS)

    Romano, Raffaele; D’Alessandro, Domenico

    2016-01-01

    In this paper we solve two equivalent time optimal control problems. On one hand, we design the control field to implement in minimum time the SWAP (or equivalent) operator on a two-level system, assuming that it interacts with an additional, uncontrollable, two-level system. On the other hand, we synthesize the SWAP operator simultaneously, in minimum time, on a pair of two-level systems subject to opposite drifts. We assume that it is possible to perform three independent control actions, and that the total control strength is bounded. These controls either affect the dynamics of the target system, under the first perspective, or, simultaneously, the dynamics of both systems, in the second view. We obtain our results by using techniques of geometric control theory on Lie groups. In particular, we apply the Pontryagin maximum principle, and provide a complete characterization of singular and nonsingular extremals. Our analysis shows that the problem can be formulated as the motion of a material point in a central force, a well known system in classical mechanics. Although we focus on obtaining the SWAP operator, many of the ideas and techniques developed in this work apply to the time optimal implementation of an arbitrary unitary operator. (paper)

  5. Minimax terminal approach problem in two-level hierarchical nonlinear discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    We consider a discrete–time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector nonlinear or linear discrete–time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solving.

  6. Experiences of building a medical data acquisition system based on two-level modeling.

    Science.gov (United States)

    Li, Bei; Li, Jianbin; Lan, Xiaoyun; An, Ying; Gao, Wuqiang; Jiang, Yuqiao

    2018-04-01

    Compared to traditional software development strategies, the two-level modeling approach is more flexible and applicable to build an information system in the medical domain. However, the standards of two-level modeling such as openEHR appear complex to medical professionals. This study aims to investigate, implement, and improve the two-level modeling approach, and discusses the experience of building a unified data acquisition system for four affiliated university hospitals based on this approach. After the investigation, we simplified the approach of archetype modeling and developed a medical data acquisition system where medical experts can define the metadata for their own specialties by using a visual easy-to-use tool. The medical data acquisition system for multiple centers, clinical specialties, and diseases has been developed, and integrates the functions of metadata modeling, form design, and data acquisition. To date, 93,353 data items and 6,017 categories for 285 specific diseases have been created by medical experts, and over 25,000 patients' information has been collected. OpenEHR is an advanced two-level modeling method for medical data, but its idea to separate domain knowledge and technical concern is not easy to realize. Moreover, it is difficult to reach an agreement on archetype definition. Therefore, we adopted simpler metadata modeling, and employed What-You-See-Is-What-You-Get (WYSIWYG) tools to further improve the usability of the system. Compared with the archetype definition, our approach lowers the difficulty. Nevertheless, to build such a system, every participant should have some knowledge in both medicine and information technology domains, as these interdisciplinary talents are necessary. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Dynamics of quantum Fisher information in a two-level system coupled to multiple bosonic reservoirs

    Science.gov (United States)

    Wang, Guo-You; Guo, You-Neng; Zeng, Ke

    2015-11-01

    We consider the optimal parameter estimation for a two-level system coupled to multiple bosonic reservoirs. By using quantum Fisher information (QFI), we investigate the effect of the Markovian reservoirs’ number N on QFI in both weak and strong coupling regimes for a two-level system surrounded by N zero-temperature reservoirs of field modes initially in the vacua. The results show that the dynamics of QFI non-monotonically decays to zero with revival oscillations at some time in the weak coupling regime depending on the reservoirs’ parameters. Furthermore, we also present the relations between the QFI flow, the flows of energy and information, and the sign of the decay rate to gain insight into the physical processes characterizing the dynamics. Project supported by the Hunan Provincial Innovation Foundation for Postgraduate, China (Grant No. CX2014B194) and the Scientific Research Foundation of Hunan Provincial Education Department, China (Grant No. 13C039).

  8. Feedback controlled dephasing and population relaxation in a two-level system

    International Nuclear Information System (INIS)

    Wang Jin

    2009-01-01

    This Letter presents the maximum achievable stability and purity that can be obtained in a two-level system with both dephasing and population relaxation processes by using homodyne-mediated feedback control. An analytic formula giving the optimal amplitudes of the driving and feedback for the steady-state is also presented. Experimental examples are used to show the importance of controlling the dephasing process.

  9. Effective Hamiltonians, two level systems, and generalized Maxwell-Bloch equations

    International Nuclear Information System (INIS)

    Sczaniecki, L.

    1981-02-01

    A new method is proposed involving a canonical transformation leading to the non-secular part of time-independent perturbation calculus. The method is used to derive expressions for effective Shen-Walls Hamiltonians which, taken in the two-level approximation and on the inclusion of non-Hamiltonian terms into the dynamics of the system, lead to generalized Maxwell-Bloch equations. The rotating wave approximation is written anew within the framework of our formalism. (author)

  10. Understanding of phase modulation in two-level systems through inverse scattering

    International Nuclear Information System (INIS)

    Hasenfeld, A.; Hammes, S.L.; Warren, W.S.

    1988-01-01

    Analytical and numerical calculations describe the effects of shaped radiation pulses on two-level systems in terms of quantum-mechanical scattering. Previous results obtained in the reduced case of amplitude modulation are extended to the general case of simultaneous amplitude and phase modulation. We show that an infinite family of phase- and amplitude-modulated pulses all generate rectangular inversion profiles. Experimental measurements also verify the theoretical analysis

  11. Aspects of two-level systems under external time-dependent fields

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G.; Wreszinski, W.F. [Tomsk State University and Tomsk Institute of High Current Electronics (Russian Federation); Barata, J.C.A.; Gitman D.M. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)]. E-mails: jbarata@fma.if.usp.br; gitman@fma.if.usp.br

    2001-12-14

    The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman et al, we discuss in detail the possibility of reducing the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility of directly applying powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for 'quantum chaos' when the external background is periodic or quasi-periodic in time. (author)

  12. Renormalization of correlations in a quasiperiodically forced two-level system: quadratic irrationals

    International Nuclear Information System (INIS)

    Mestel, B D; Osbaldestin, A H

    2004-01-01

    Generalizing from the case of golden mean frequency to a wider class of quadratic irrationals, we extend our renormalization analysis of the self-similarity of correlation functions in a quasiperiodically forced two-level system. We give a description of all piecewise-constant periodic orbits of an additive functional recurrence generalizing that present in the golden mean case. We establish a criterion for periodic orbits to be globally bounded, and also calculate the asymptotic height of the main peaks in the correlation function

  13. Comprehensive solutions to the Bloch equations and dynamical models for open two-level systems

    Science.gov (United States)

    Skinner, Thomas E.

    2018-01-01

    The Bloch equation and its variants constitute the fundamental dynamical model for arbitrary two-level systems. Many important processes, including those in more complicated systems, can be modeled and understood through the two-level approximation. It is therefore of widespread relevance, especially as it relates to understanding dissipative processes in current cutting-edge applications of quantum mechanics. Although the Bloch equation has been the subject of considerable analysis in the 70 years since its inception, there is still, perhaps surprisingly, significant work that can be done. This paper extends the scope of previous analyses. It provides a framework for more fully understanding the dynamics of dissipative two-level systems. A solution is derived that is compact, tractable, and completely general, in contrast to previous results. Any solution of the Bloch equation depends on three roots of a cubic polynomial that are crucial to the time dependence of the system. The roots are typically only sketched out qualitatively, with no indication of their dependence on the physical parameters of the problem. Degenerate roots, which modify the solutions, have been ignored altogether. Here the roots are obtained explicitly in terms of a single real-valued root that is expressed as a simple function of the system parameters. For the conventional Bloch equation, a simple graphical representation of this root is presented that makes evident the explicit time dependence of the system for each point in the parameter space. Several intuitive, visual models of system dynamics are developed. A Euclidean coordinate system is identified in which any generalized Bloch equation is separable, i.e., the sum of commuting rotation and relaxation operators. The time evolution in this frame is simply a rotation followed by relaxation at modified rates that play a role similar to the standard longitudinal and transverse rates. These rates are functions of the applied field, which

  14. Scanning Electron Microscope Analysis System

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides the capability to examine surfaces microscopically with high resolution (5 nanometers), perform micro chemical analyses of these surfaces, and...

  15. On Two-Level State-Dependent Routing Polling Systems with Mixed Service

    Directory of Open Access Journals (Sweden)

    Guan Zheng

    2015-01-01

    Full Text Available Based on priority differentiation and efficiency of the system, we consider an N+1 queues’ single-server two-level polling system which consists of one key queue and N normal queues. The novel contribution of the present paper is that we consider that the server just polls active queues with customers waiting in the queue. Furthermore, key queue is served with exhaustive service and normal queues are served with 1-limited service in a parallel scheduling. For this model, we derive an expression for the probability generating function of the joint queue length distribution at polling epochs. Based on these results, we derive the explicit closed-form expressions for the mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical and the new system is efficient both at key queue and normal queues.

  16. Detuning-induced stimulated Raman adiabatic passage in dense two-level systems

    Science.gov (United States)

    Deng, Li; Lin, Gongwei; Niu, Yueping; Gong, Shangqing

    2018-05-01

    We investigate the coherence generation in dense two-level systems under detuning-induced stimulated Raman adiabatic passage (D-STIRAP). In the dense two-level system, the near dipole-dipole (NDD) interaction should be taken into consideration. With the increase in the strength of the NDD interaction, it is found that a switchlike transition of the generated coherence from maximum value to zero appears. Meanwhile, the adiabatic condition of the D-STIRAP is destroyed in the presence of the NDD interaction. In order to avoid the sudden decrease in the generated coherence and maintain the maximum value, we can use stronger detuning pulse or pump pulse, between which increasing the intensity of the detuning pulse is of more efficiency. Except for taking advantage of such maximum coherence in the high density case into areas like enhancing the four-wave mixing process, we also point out that the phenomenon of the coherence transition can be applied as an optical switch.

  17. Amplification without inversion, fast light and optical bistability in a duplicated two-level system

    International Nuclear Information System (INIS)

    Ebrahimi Zohravi, Lida; Vafafard, Azar; Mahmoudi, Mohammad

    2014-01-01

    The optical properties of a weak probe field in a duplicated two-level system are investigated in multi-photon resonance (MPR) condition and beyond it. It is shown that by changing the relative phase of applied fields, the absorption switches to the amplification without inversion in MPR condition. By applying the Floquet decomposition to the equations of motion beyond MPR condition, it is shown that the phase-dependent behavior is valid only in MPR condition. Moreover, it is demonstrated that the group velocity of light pulse can be controlled by the intensity of the applied fields and the gain-assisted superluminal light propagation (fast light) is obtained in this system. In addition, the optical bistability (OB) behavior of the system is studied beyond MPR condition. We apply an indirect incoherent pumping field to the system and it is found that the group velocity and OB behavior of the system can be controlled by the incoherent pumping rate. - Highlights: • We studied the optical properties of DTL system under MPR condition and beyond it. • By changing the relative phase, the absorption switches to the amplification without inversion in MPR condition. • The gain-assisted superluminal light propagation (fast light) is obtained in this system. • The optical bistability (OB) behavior of the system is studied beyond MPR condition. • The incoherent pumping rate has a major role in controlling the group velocity and OB behavior of the system

  18. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  19. Dynamical Evolution of an Effective Two-Level System with {\\mathscr{P}}{\\mathscr{T}} Symmetry

    Science.gov (United States)

    Du, Lei; Xu, Zhihao; Yin, Chuanhao; Guo, Liping

    2018-05-01

    We investigate the dynamics of parity- and time-reversal (PT ) symmetric two-energy-level atoms in the presence of two optical and a radio-frequency (rf) fields. The strength and relative phase of fields can drive the system from unbroken to broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of unbroken PT symmetry. At exception point (EP), the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find the emergence of the z components of the fixed points is the feature of the PT symmetry breaking and the projections in x-y plane can be controlled with high flexibility compared with the standard two-level system with PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model.

  20. Faithful state transfer between two-level systems via an actively cooled finite-temperature cavity

    Science.gov (United States)

    Sárkány, Lőrinc; Fortágh, József; Petrosyan, David

    2018-03-01

    We consider state transfer between two qubits—effective two-level systems represented by Rydberg atoms—via a common mode of a microwave cavity at finite temperature. We find that when both qubits have the same coupling strength to the cavity field, at large enough detuning from the cavity mode frequency, quantum interference between the transition paths makes the swap of the excitation between the qubits largely insensitive to the number of thermal photons in the cavity. When, however, the coupling strengths are different, the photon-number-dependent differential Stark shift of the transition frequencies precludes efficient transfer. Nevertheless, using an auxiliary cooling system to continuously extract the cavity photons, we can still achieve a high-fidelity state transfer between the qubits.

  1. Dynamical model of coherent circularly polarized optical pulse interactions with two-level quantum systems

    International Nuclear Information System (INIS)

    Slavcheva, G.; Hess, O.

    2005-01-01

    We propose and develop a method for theoretical description of circularly (elliptically) polarized optical pulse resonant coherent interactions with two-level atoms. The method is based on the time-evolution equations of a two-level quantum system in the presence of a time-dependent dipole perturbation for electric dipole transitions between states with total angular-momentum projection difference (ΔJ z =±1) excited by a circularly polarized electromagnetic field [Feynman et al., J. Appl. Phys. 28, 49 (1957)]. The adopted real-vector representation approach allows for coupling with the vectorial Maxwell's equations for the optical wave propagation and thus the resulting Maxwell pseudospin equations can be numerically solved in the time domain without any approximations. The model permits a more exact study of the ultrafast coherent pulse propagation effects taking into account the vector nature of the electromagnetic field and hence the polarization state of the optical excitation. We demonstrate self-induced transparency effects and formation of polarized solitons. The model represents a qualitative extension of the well-known optical Maxwell-Bloch equations valid for linearly polarized light and a tool for studying coherent quantum control mechanisms

  2. Transmission-line resonators for the study of individual two-level tunneling systems

    Science.gov (United States)

    Brehm, Jan David; Bilmes, Alexander; Weiss, Georg; Ustinov, Alexey V.; Lisenfeld, Jürgen

    2017-09-01

    Parasitic two-level tunneling systems (TLS) emerge in amorphous dielectrics and constitute a serious nuisance for various microfabricated devices, where they act as a source of noise and decoherence. Here, we demonstrate a new test bed for the study of TLS in various materials which provides access to properties of individual TLS as well as their ensemble response. We terminate a superconducting transmission-line resonator with a capacitor that hosts TLS in its dielectric. By tuning TLS via applied mechanical strain, we observe the signatures of individual TLS strongly coupled to the resonator in its transmission characteristics and extract the coupling components of their dipole moments and energy relaxation rates. The strong and well-defined coupling to the TLS bath results in pronounced resonator frequency fluctuations and excess phase noise, through which we can study TLS ensemble effects such as spectral diffusion, and probe theoretical models of TLS interactions.

  3. Dynamics of a quantum two-level system under the action of phase-diffusion field

    Energy Technology Data Exchange (ETDEWEB)

    Sobakinskaya, E.A. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Pankratov, A.L., E-mail: alp@ipm.sci-nnov.ru [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Vaks, V.L. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation)

    2012-01-09

    We study a behavior of quantum two-level system, interacting with noisy phase-diffusion field. The dynamics is shown to split into two regimes, determined by the coherence time of the phase-diffusion field. For both regimes we present a model of quantum system behavior and discuss possible applications of the obtained effect for spectroscopy. In particular, the obtained analytical formula for the macroscopic polarization demonstrates that the phase-diffusion field does not affect the absorption line shape, which opens up an intriguing possibility of noisy spectroscopy, based on broadband sources with Lorentzian line shape. -- Highlights: ► We study dynamics of quantum system interacting with noisy phase-diffusion field. ► At short times the phase-diffusion field induces polarization in the quantum system. ► At long times the noise leads to polarization decay and heating of a quantum system. ► Simple model of interaction is derived. ► Application of the described effects for spectroscopy is discussed.

  4. A Two-Level Task Scheduler on Multiple DSP System for OpenCL

    Directory of Open Access Journals (Sweden)

    Li Tian

    2014-04-01

    Full Text Available This paper addresses the problem that multiple DSP system does not support OpenCL programming. With the compiler, runtime, and the kernel scheduler proposed, an OpenCL application becomes portable not only between multiple CPU and GPU, but also between embedded multiple DSP systems. Firstly, the LLVM compiler was imported for source-to-source translation in which the translated source was supported by CCS. Secondly, two-level schedulers were proposed to support efficient OpenCL kernel execution. The DSP/BIOS is used to schedule system level tasks such as interrupts and drivers; however, the synchronization mechanism resulted in heavy overhead during task switching. So we designed an efficient second level scheduler especially for OpenCL kernel work-item scheduling. The context switch process utilizes the 8 functional units and cross path links which was superior to DSP/BIOS in the aspect of task switching. Finally, dynamic loading and software managed CACHE were redesigned for OpenCL running on multiple DSP system. We evaluated the performance using some common OpenCL kernels from NVIDIA, AMD, NAS, and Parboil benchmarks. Experimental results show that the DSP OpenCL can efficiently exploit the computing resource of multiple cores.

  5. A distributed monitoring system for photovoltaic arrays based on a two-level wireless sensor network

    Science.gov (United States)

    Su, F. P.; Chen, Z. C.; Zhou, H. F.; Wu, L. J.; Lin, P. J.; Cheng, S. Y.; Li, Y. F.

    2017-11-01

    In this paper, a distributed on-line monitoring system based on a two-level wireless sensor network (WSN) is proposed for real time status monitoring of photovoltaic (PV) arrays to support the fine management and maintenance of PV power plants. The system includes the sensing nodes installed on PV modules (PVM), sensing and routing nodes installed on combiner boxes of PV sub-arrays (PVA), a sink node and a data management centre (DMC) running on a host computer. The first level WSN is implemented by the low-cost wireless transceiver nRF24L01, and it is used to achieve single hop communication between the PVM nodes and their corresponding PVA nodes. The second level WSN is realized by the CC2530 based ZigBee network for multi-hop communication among PVA nodes and the sink node. The PVM nodes are used to monitor the PVM working voltage and backplane temperature, and they send the acquired data to their PVA node via the nRF24L01 based first level WSN. The PVA nodes are used to monitor the array voltage, PV string current and environment irradiance, and they send the acquired and received data to the DMC via the ZigBee based second level WSN. The DMC is designed using the MATLAB GUIDE and MySQL database. Laboratory experiment results show that the system can effectively acquire, display, store and manage the operating and environment parameters of PVA in real time.

  6. Dynamical properties of a two-level system with arbitrary nonlinearities

    Indian Academy of Sciences (India)

    nication, information processing and quantum computing, such as in the investigation of quantum teleportation ... They con- sidered a two-level atom interacting with an undamped cavity initially in a coherent state. ... Because concurrence pro-.

  7. Acoustic interactions between inversion symmetric and asymmetric two-level systems

    International Nuclear Information System (INIS)

    Churkin, A; Schechter, M; Barash, D

    2014-01-01

    Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs), facilitated by the interaction of the TLSs with the phonon field. TLS-phonon interaction also mediates effective TLS–TLS interactions, which dictates the existence of a glassy phase and its low energy properties. Here we consider KBr:CN, the archetypal disordered lattice showing universality. We calculate numerically, using conjugate gradients method, the effective TLS–TLS interactions for inversion symmetric (CN flips) and asymmetric (CN rotations) TLSs, in the absence and presence of disorder, in two and three dimensions. The observed dependence of the magnitude and spatial power law of the interaction on TLS symmetry, and its change with disorder, characterizes TLS–TLS interactions in disordered lattices in both extreme and moderate dilutions. Our results are in good agreement with the two-TLS model, recently introduced to explain long-standing questions regarding the quantitative universality of phonon attenuation and the energy scale of ≈1–3 K below which universality is observed. (paper)

  8. Crises-induced intermittencies in a coherently driven system of two-level atoms

    International Nuclear Information System (INIS)

    Pando L, C.L.; Perez, G.; Cerdeira, H.A.

    1993-04-01

    We study the coherent dynamics of a thin layer of two-level atoms driven by an external coherent field and a phase conjugated mirror (PCM). Since the variables of the system are defined on the Bloch sphere, the third dimension is provided by the temporal modulation of the Rabi frequencies, which are induced by a PCM which reflects an electric field with a carrier frequency different from the incident one. We show that as the PCM gain coefficient is changed period doubling leading to chaos occurs. We find crises of attractor merging and attractor widening types related to homoclinic and heteroclinic tangencies respectively. For the attractor merging crises we find the critical exponent for the characteristic time of intermittency versus the control parameter which is given by the gain coefficient of the PCM. We show that during the crises of attractor widening type, another crisis due to attractor destruction occurs as the control parameter is changed. The latter is due to the collision of the old attractor with its basin boundary when a new attractor is created. This new attractor is stable only in a very small interval in the neighborhood of this second crisis. (author). 31 refs, 15 figs

  9. Two levels decision system for efficient planning and implementation of bioenergy production

    International Nuclear Information System (INIS)

    Ayoub, Nasser; Martins, Ricardo; Wang, Kefeng; Seki, Hiroya; Naka, Yuji

    2007-01-01

    When planning bioenergy production from biomass, planners should take into account each and every stakeholder along the biomass supply chains, e.g. biomass resources suppliers, transportation, conversion and electricity suppliers. Also, the planners have to consider social concerns, environmental and economical impacts related with establishing the biomass systems and the specific difficulties of each country. To overcome these problems in a sustainable manner, a robust decision support system is required. For that purpose, a two levels general Bioenergy Decision System (gBEDS) for bioenergy production planning and implementation was developed. The core part of the gBEDS is the information base, which includes the basic bioenergy information and the detailed decision information. Basic bioenergy information include, for instance, the geographical information system (GIS) database, the biomass materials' database, the biomass logistic database and the biomass conversion database. The detailed decision information considers the parameters' values database with their default values and the variables database, values obtained by simulation and optimization. It also includes a scenario database, which is used for demonstration to new users and also for case based reasoning by planners and executers. Based on the information base, the following modules are included to support decision making: the simulation module with graph interface based on the unit process (UP) definition and the genetic algorithms (GAs) methods for optimal decisions and the Matlab module for applying data mining methods (fuzzy C-means clustering and decision trees) to the biomass collection points, to define the location of storage and bioenergy conversion plants based on the simulation and optimization model developed of the whole life cycle of bioenergy generation. Furthermore, Matlab is used to set up a calculation model with crucial biomass planning parameters (e.g. costs, CO 2 emissions), over

  10. Analysis of Two-Level Support Systems with Time-Dependent Overflow - A Banking Application

    DEFF Research Database (Denmark)

    Barth, Wolfgang; Manitz, Michael; Stolletz, Raik

    2010-01-01

    In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time-dependent overflow mechanism. Waiting calls from the front-office queue flow over to the back office if a waiting-time limit is reached and at least one back-office agent...

  11. Quantum theory of phonon-mediated decoherence and relaxation of two-level systems in a structured electromagnetic reservoir

    Science.gov (United States)

    Roy, Chiranjeeb

    In this thesis we study the role of nonradiative degrees of freedom on quantum optical properties of mesoscopic quantum dots placed in the structured electromagnetic reservoir of a photonic crystal. We derive a quantum theory of the role of acoustic and optical phonons in modifying the optical absorption lineshape, polarization dynamics, and population dynamics of a two-level atom (quantum dot) in the "colored" electromagnetic vacuum of a photonic band gap (PBG) material. This is based on a microscopic Hamiltonian describing both radiative and vibrational processes quantum mechanically. Phonon sidebands in an ordinary electromagnetic reservoir are recaptured in a simple model of optical phonons using a mean-field factorization of the atomic and lattice displacement operators. Our formalism is then used to treat the non-Markovian dynamics of the same system within the structured electromagnetic density of states of a photonic crystal. We elucidate the extent to which phonon-assisted decay limits the lifetime of a single photon-atom bound state and derive the modified spontaneous emission dynamics due to coupling to various phonon baths. We demonstrate that coherent interaction with undamped phonons can lead to enhanced lifetime of a photon-atom bound state in a PBG by (i) dephasing and reducing the transition electric dipole moment of the atom and (ii) reducing the quantum mechanical overlap of the state vectors of the excited and ground state (polaronic shift). This results in reduction of the steady-state atomic polarization but an increase in the fractionalized upper state population in the photon-atom bound state. We demonstrate, on the other hand, that the lifetime of the photon-atom bound state in a PBG is limited by the lifetime of phonons due to lattice anharmonicities (break-up of phonons into lower energy phonons) and purely nonradiative decay. We demonstrate how these additional damping effects limit the extent of the polaronic (Franck-Condon) shift of

  12. Open quantum systems and the two-level atom interacting with a single mode of the electromagnetic field

    International Nuclear Information System (INIS)

    Sandulescu, A.; Stefanescu, E.

    1987-07-01

    On the basis of Lindblad theory of open quantum systems we obtain new optical equations for the system of two-level atom interacting with a single mode of the electromagnetic field. The conventional Block equations in a generalized form with field phases are obtained in the hypothesis that all the terms are slowly varying in the rotating frame.(authors)

  13. IMIS: An intelligence microscope imaging system

    Science.gov (United States)

    Caputo, Michael; Hunter, Norwood; Taylor, Gerald

    1994-01-01

    Until recently microscope users in space relied on traditional microscopy techniques that required manual operation of the microscope and recording of observations in the form of written notes, drawings, or photographs. This method was time consuming and required the return of film and drawings from space for analysis. No real-time data analysis was possible. Advances in digital and video technologies along with recent developments in article intelligence will allow future space microscopists to have a choice of three additional modes of microscopy: remote coaching, remote control, and automation. Remote coaching requires manual operations of the microscope with instructions given by two-way audio/video transmission during critical phases of the experiment. When using the remote mode of microscopy, the Principal Investigator controls the microscope from the ground. The automated mode employs artificial intelligence to control microscope functions and is the only mode that can be operated in the other three modes as well. The purpose of this presentation is to discuss the advantages and disadvantages of the four modes of of microscopy and how the IMIS, a proposed intelligent microscope imaging system, can be used as a model for developing and testing concepts, operating procedures, and equipment design of specifications required to provide a comprehensive microscopy/imaging capability onboard Space Station Freedom.

  14. Quantum driving protocols for a two-level system: From generalized Landau-Zener sweeps to transitionless control

    DEFF Research Database (Denmark)

    Malossi, Nicola; Bason, Mark George; Viteau, Matthieu

    2013-01-01

    We present experimental results on the preparation of a desired quantum state in a two-level system with the maximum possible fidelity using driving protocols ranging from generalizations of the linear Landau-Zener protocol to transitionless driving protocols that ensure perfect following of the ...

  15. Organization of the two-level memory in the image processing system on scanning measuring projectors

    International Nuclear Information System (INIS)

    Sychev, A.Yu.

    1977-01-01

    Discussed are the problems of improving the efficiency of the system for processing pictures taken in bubble chambers with the use of scanning measuring projectors. The system comprises 20 to 30 pro ectors linked with the ICL-1903A computer provided with a mainframe memory, 64 kilobytes in size. Because of the insufficient size of a mainframe memory, a part of the programs and data is located in a second-level memory, i.e. in an external memory. The analytical model described herein is used to analyze the effect of the memory organization on the characteristics of the system. It is shown that organization of pure procedures and introduction of the centralized control of the tWo-leVel memory result in substantial improvement of the efficiency of the picture processing system

  16. Optimization of Two-Level Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance Strategy

    Directory of Open Access Journals (Sweden)

    Zouhour Guiras

    2018-04-01

    Full Text Available With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.

  17. Information systems performance evaluation, introducing a two-level technique: Case study call centers

    Directory of Open Access Journals (Sweden)

    Hesham A. Baraka

    2015-03-01

    The objective of this paper was to introduce a new technique that can support decision makers in the call centers industry to evaluate, and analyze the performance of call centers. The technique presented is derived from the research done on measuring the success or failure of information systems. Two models are mainly adopted namely: the Delone and Mclean model first introduced in 1992 and the Design Reality Gap model introduced by Heeks in 2002. Two indices are defined to calculate the performance of the call center; the success index and the Gap Index. An evaluation tool has been developed to allow call centers managers to evaluate the performance of their call centers in a systematic analytical approach; the tool was applied on 4 call centers from different areas, simple applications such as food ordering, marketing, and sales, technical support systems, to more real time services such as the example of emergency control systems. Results showed the importance of using information systems models to evaluate complex systems as call centers. The models used allow identifying the dimensions for the call centers that are facing challenges, together with an identification of the individual indicators in these dimensions that are causing the poor performance of the call center.

  18. On irreversible evolutions of two-level systems approaching coherent and squeezed states

    International Nuclear Information System (INIS)

    Jurco, B.; Tolar, J.

    1988-01-01

    The concepts of completely positive quantum dynamical semigroups and SU(2)-related generalized coherence and squeezing are used to investigate conditions for Markovian evolutions leading to coherent, intelligent, minimum-uncertainty and squeezed asymptotic stationary states in a 2-level system. (author). 10 refs

  19. Two-Level Control for Fast Electrical Vehicle Charging Stations with Multi Flywheel Energy Storage System

    DEFF Research Database (Denmark)

    SUN, BO; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2015-01-01

    This paper applies a hierarchical control for a fast charging station (FCS) composed of paralleled PWM rectifier and dedicated paralleled multiple flywheel energy storage systems (FESSs), in order to mitigate peak power shock on grid caused by sudden connection of electrical vehicle (EV) chargers...

  20. Adiabatic passage for a lossy two-level quantum system by a complex time method

    International Nuclear Information System (INIS)

    Dridi, G; Guérin, S

    2012-01-01

    Using a complex time method with the formalism of Stokes lines, we establish a generalization of the Davis–Dykhne–Pechukas formula which gives in the adiabatic limit the transition probability of a lossy two-state system driven by an external frequency-chirped pulse-shaped field. The conditions that allow this generalization are derived. We illustrate the result with the dissipative Allen–Eberly and Rosen–Zener models. (paper)

  1. Minimax approach problem with incomplete information for the two-level hierarchical discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F. [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia and Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2014-11-18

    We consider a discrete-time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector linear or convex discrete-time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solution.

  2. Geometric phase for a two-level system in photonic band gab crystal

    Science.gov (United States)

    Berrada, K.

    2018-05-01

    In this work, we investigate the geometric phase (GP) for a qubit system coupled to its own anisotropic and isotropic photonic band gap (PBG) crystal environment without Born or Markovian approximation. The qubit frequency affects the GP of the qubit directly through the effect of the PBG environment. The results show the deviation of the GP depends on the detuning parameter and this deviation will be large for relatively large detuning of atom frequency inside the gap with respect to the photonic band edge. Whereas for detunings outside the gap, the GP of the qubit changes abruptly to zero, exhibiting collapse phenomenon of the GP. Moreover, we find that the GP in the isotropic PBG photonic crystal is more robust than that in the anisotropic PBG under the same condition. Finally, we explore the relationship between the variation of the GP and population in terms of the physical parameters.

  3. Modelling thermionic emission by using a two-level mechanical system

    International Nuclear Information System (INIS)

    Battaglia, O.R.

    2008-01-01

    The Boltzmann factor is at the basis of a great amount of thermodynamic and statistical physics, both classical and quantum. It describes the behaviour of natural systems that exchange energy with the environment. However, why does the expression have that specific form? The Feynman Lectures on Physics justifies it heuristically by referencing to the exponential atmosphere example. Thermodynamics textbooks usually give a more or less complete explanation that mainly involves a mathematical analysis, where it is hard to see the logic flow. Moreover, the necessary mathematics is not at the level of high school or college students' preparation. Here we present an experiment and a simulation at deriving the Boltzmann factor expression and illustrating the fundamental concepts and principles of statistical mechanics. Experiments and simulations are used in order to visualise the mechanism involved; the experiments use easily available laboratory equipment, and simulations are developed in Net Logo, a software environment that, besides having a really friendly interface, allows the user to easily interact with the algorithm, as well as to modify it.

  4. Non-Hermitian wave packet approximation for coupled two-level systems in weak and intense fields

    Energy Technology Data Exchange (ETDEWEB)

    Puthumpally-Joseph, Raiju; Charron, Eric [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay (France); Sukharev, Maxim [Science and Mathematics Faculty, College of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States)

    2016-04-21

    We introduce a non-Hermitian Schrödinger-type approximation of optical Bloch equations for two-level systems. This approximation provides a complete and accurate description of the coherence and decoherence dynamics in both weak and strong laser fields at the cost of losing accuracy in the description of populations. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin layer comprised of interacting two-level emitters.

  5. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  6. Relaxation dynamics of a driven two-level system coupled to a Bose-Einstein condensate: application to quantum dot-dipolar exciton gas hybrid systems.

    Science.gov (United States)

    Kovalev, Vadim M; Tse, Wang-Kong

    2017-11-22

    We develop a microscopic theory for the relaxation dynamics of an optically pumped two-level system (TLS) coupled to a bath of weakly interacting Bose gas. Using Keldysh formalism and diagrammatic perturbation theory, expressions for the relaxation times of the TLS Rabi oscillations are derived when the boson bath is in the normal state and the Bose-Einstein condensate (BEC) state. We apply our general theory to consider an irradiated quantum dot coupled with a boson bath consisting of a two-dimensional dipolar exciton gas. When the bath is in the BEC regime, relaxation of the Rabi oscillations is due to both condensate and non-condensate fractions of the bath bosons for weak TLS-light coupling and pre dominantly due to the non-condensate fraction for strong TLS-light coupling. Our theory also shows that a phase transition of the bath from the normal to the BEC state strongly influences the relaxation rate of the TLS Rabi oscillations. The TLS relaxation rate is approximately independent of the pump field frequency and monotonically dependent on the field strength when the bath is in the low-temperature regime of the normal phase. Phase transition of the dipolar exciton gas leads to a non-monotonic dependence of the TLS relaxation rate on both the pump field frequency and field strength, providing a characteristic signature for the detection of BEC phase transition of the coupled dipolar exciton gas.

  7. Entropy as a measure of the noise extent in a two-level quantum feedback controlled system

    Institute of Scientific and Technical Information of China (English)

    Wang Tao-Bo; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    By introducing the von Neumann entropy as a measure of the extent of noise, this paper discusses the entropy evolution in a two-level quantum feedback controlled system. The results show that the feedback control can induce the reduction of the degree of noise, and different control schemes exhibit different noise controlling ability, the extent of the reduction also related with the position of the target state on the Bloch sphere. It is shown that the evolution of entropy can provide a real time noise observation and a systematic guideline to make reasonable choice of control strategy.

  8. Comparison of PI and PR current controllers applied on two-level VSC-HVDC transmission system

    DEFF Research Database (Denmark)

    Manoloiu, A.; Pereria, H.A.; Teodorescu, Remus

    2015-01-01

    This paper analyzes differences between αβ and dq reference frames regarding the control of two-level VSC-HVDC current loop and dc-link voltage outer loop. In the first part, voltage feedforward effect is considered with PI and PR controllers. In the second part, the feedforward effect is removed...... and the PR gains are tuned to keep the dynamic performance. Also, the power feedforward is removed and the outer loop PI controller is tuned in order to maintain the system dynamic performance. The paper is completed with simulation results, which highlight the advantages of using PR controller....

  9. Experimental study of magnetocaloric effect in the two-level quantum system KTm(MoO4)2

    Science.gov (United States)

    Tarasenko, R.; Tkáč, V.; Orendáčová, A.; Orendáč, M.; Valenta, J.; Sechovský, V.; Feher, A.

    2018-05-01

    KTm(MoO4)2 belongs to the family of binary alkaline rare-earth molybdates. This compound can be considered to be an almost ideal quantum two-level system at low temperatures. Magnetocaloric properties of KTm(MoO4)2 single crystals were investigated using specific heat and magnetization measurement in the magnetic field applied along the easy axis. Large conventional magnetocaloric effect (-ΔSM ≈ 10.3 J/(kg K)) was observed in the magnetic field of 5 T in a relatively wide temperature interval. The isothermal magnetic entropy change of about 8 J/(kgK) has been achieved already for the magnetic field of 2 T. Temperature dependence of the isothermal entropy change under different magnetic fields is in good agreement with theoretical predictions for a quantum two-level system with Δ ≈ 2.82 cm-1. Investigation of magnetocaloric properties of KTm(MoO4)2 suggests that the studied system can be considered as a good material for magnetic cooling at low temperatures.

  10. Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles

    International Nuclear Information System (INIS)

    Grace, Matthew; Brif, Constantin; Rabitz, Herschel; Walmsley, Ian A; Kosut, Robert L; Lidar, Daniel A

    2007-01-01

    Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions

  11. Design of a Two-level Adaptive Multi-Agent System for Malaria Vectors driven by an ontology

    Directory of Open Access Journals (Sweden)

    Etang Josiane

    2007-07-01

    Full Text Available Abstract Background The understanding of heterogeneities in disease transmission dynamics as far as malaria vectors are concerned is a big challenge. Many studies while tackling this problem don't find exact models to explain the malaria vectors propagation. Methods To solve the problem we define an Adaptive Multi-Agent System (AMAS which has the property to be elastic and is a two-level system as well. This AMAS is a dynamic system where the two levels are linked by an Ontology which allows it to function as a reduced system and as an extended system. In a primary level, the AMAS comprises organization agents and in a secondary level, it is constituted of analysis agents. Its entry point, a User Interface Agent, can reproduce itself because it is given a minimum of background knowledge and it learns appropriate "behavior" from the user in the presence of ambiguous queries and from other agents of the AMAS in other situations. Results Some of the outputs of our system present a series of tables, diagrams showing some factors like Entomological parameters of malaria transmission, Percentages of malaria transmission per malaria vectors, Entomological inoculation rate. Many others parameters can be produced by the system depending on the inputted data. Conclusion Our approach is an intelligent one which differs from statistical approaches that are sometimes used in the field. This intelligent approach aligns itself with the distributed artificial intelligence. In terms of fight against malaria disease our system offers opportunities of reducing efforts of human resources who are not obliged to cover the entire territory while conducting surveys. Secondly the AMAS can determine the presence or the absence of malaria vectors even when specific data have not been collected in the geographical area. In the difference of a statistical technique, in our case the projection of the results in the field can sometimes appeared to be more general.

  12. Quantum correlations between each two-level system in a pair of atoms and general coherent fields

    Directory of Open Access Journals (Sweden)

    S. Abdel-Khalek

    Full Text Available The quantitative description of the quantum correlations between each two-level system in a two-atom system and the coherent fields initially defined in a coherent state in the framework of power-law potentials (PLPCSs is considered. Specifically, we consider two atoms locally interacting with PLPCSs and take into account the different terms of interactions, the entanglement and quantum discord are studied including the time-dependent coupling and photon transition effects. Using the monogamic relation between the entanglement of formation and quantum discord in tripartite systems, we show that the control and preservation of the different kinds of quantum correlations greatly benefit from the combination of the choice of the physical quantities. Finally, we explore the link between the dynamical behavior of quantum correlations and nonclassicality of the fields with and without atomic motion effect. Keywords: Quantum correlations, Monogamic relation, Coherent states, Power-law potentials, Wehrl entropy

  13. Dynamics of a Landau-Zener transitions in a two-level system driven by a dissipative environment

    Science.gov (United States)

    Ateuafack, M. E.; Diffo, J. T.; Fai, L. C.

    2016-02-01

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  14. Dynamics of a Landau–Zener transitions in a two-level system driven by a dissipative environment

    Energy Technology Data Exchange (ETDEWEB)

    Ateuafack, M.E., E-mail: esouamath@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Diffo, J.T., E-mail: diffojaures@yahoo.com [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Department of Physics, Higher Teachers' Training College, The University of Maroua, PO Box 55 Maroua (Cameroon); Fai, L.C., E-mail: corneliusfai@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon)

    2016-02-15

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  15. A Two-Level Sensorless MPPT Strategy Using SRF-PLL on a PMSG Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Amina Echchaachouai

    2017-01-01

    Full Text Available In this paper, a two-level sensorless Maximum Power Point Tracking (MPPT strategy is presented for a variable speed Wind Energy Conversion System (WECS. The proposed system is composed of a wind turbine, a direct-drive Permanent Magnet Synchronous Generator (PMSG and a three phase controlled rectifier connected to a DC load. The realised generator output power maximization analysis justifies the use of the Field Oriented Control (FOC giving the six Pulse Width Modulation (PWM signals to the active rectifier. The generator rotor speed and position required by the FOC and the sensorless MPPT are estimated using a Synchronous Reference Frame Phase Locked Loop (SRF-PLL. The MPPT strategy used consists of two levels, the first level is a power regulation loop and the second level is an extremum seeking bloc generating the coefficient gathering the turbine characteristics. Experimental results validated on a hardware test setup using a DSP digital board (dSPACE 1104 are presented. Figures illustrating the estimated speed and angle confirm that the SRF-PLL is able to give an estimated speed and angle which closely follow the real ones. Also, the power at the DC load and the power at the generator output indicate that the MPPT gives optimum extracted power. Finally, other results show the effectiveness of the adopted approach in real time applications.

  16. Transverse magnetic field effect on the giant Goos–Hänchen shifts based on a degenerate two-level system

    Science.gov (United States)

    Nasehi, R.

    2018-06-01

    We study the effect of the Goos–Hänchen (GH) shifts through a cavity with degenerate two-level systems in the line of . For this purpose, we focus on the transverse magnetic field (TMF) in a Floquet frame to obtain the giant GH shifts. Physically, the collisional effects of TMF lead to increasing the population trapping in the ground state. However, we demonstrate that the population trapping generates the large negative or positive GH shifts and simultaneously switches from superluminal to subluminal (or vice versa). Also, we investigate the other optical properties such as the longitudinal magnetic field (LMF), which plays an important role in the control of the GH shifts and leads to the generation of new subsystems. In the next step, we evaluate the GH shifts beyond the multi-photon resonance condition by the control of TMF. Moreover, we compute the appearance of negative and positive GH shifts by setting the width of the incident Gaussian beams in the presence of a multi-photon resonance condition. Our results show that superluminal or subluminal light propagation can be simultaneously controlled by adjusting the rates of the TMF and LMF. The significant effects of these factors on the degenerate two-level systems provide different applications such as slow light, optical switches and quantum information storage.

  17. Microscopic calculation of the 4He system

    International Nuclear Information System (INIS)

    Hofmann, H.M.

    1996-01-01

    We report on a consistent, microscopic calculation of the bound and scattering states in the 4 He system employing a realistic nucleon-nucleon potential in the framework of the resonating group model (RGM). We present for comparison with these microscopic RGM calculations the results from a charge-independent, Coulomb-corrected R-matrix analysis of all types of data for reactions in the A=4 system. Comparisons are made between the phase shifts, and with a selection of measurements from each reaction, as well as between the resonance spectra obtained from both calculations. In general, the comparisons are favorable, but distinct differences are observed between the RGM calculations and some of the polarisation data. The partial-wave decomposition of the experimental data produced by the R-matrix analysis shows that these differences can be attributed to just a few S-matrix elements, for which inadequate tensor-force strength in the N-N interaction used appears to be responsible. (orig.)

  18. System modelling of a lateral force microscope

    International Nuclear Information System (INIS)

    Michal, Guillaume; Lu, Cheng; Kiet Tieu, A

    2008-01-01

    To quantitatively analyse lateral force microscope measurements one needs to develop a model able to relate the photodiode signal to the force acting on the tip apex. In this paper we focus on the modelling of the interaction between the cantilever and the optical chain. The laser beam is discretized by a set of rays which propagates in the system. The analytical equation of a single ray's position on the optical sensor is presented as a function of the reflection's state on top of the cantilever. We use a finite element analysis on the cantilever to connect the optical model with the force acting on the tip apex. A first-order approximation of the constitutive equations are derived along with a definition of the system's crosstalk. Finally, the model is used to analytically simulate the 'wedge method' in the presence of crosstalk in 2D. The analysis shows how the torsion loop and torsion offset signals are affected by the crosstalk.

  19. System for optical sorting of microscopic objects

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a system for optical sorting of microscopic objects and corresponding method. An optical detection system (52) is capable of determining the positions of said first and/or said second objects. One or more force transfer units (200, 205, 210, 215) are placed...... in a first reservoir, the one or more force units being suitable for optical momentum transfer. An electromagnetic radiation source (42) yields a radiation beam (31, 32) capable of optically displacing the force transfer units from one position to another within the first reservoir (1R). The force transfer...... units are displaced from positions away from the first objects to positions close to the first objects, and then displacing the first objects via a contact force (300) between the first objects and the force transfer units facilitates an optical sorting of the first objects and the second objects....

  20. Quantum phase transition in a coupled two-level system embedded in anisotropic three-dimensional photonic crystals.

    Science.gov (United States)

    Shen, H Z; Shao, X Q; Wang, G C; Zhao, X L; Yi, X X

    2016-01-01

    The quantum phase transition (QPT) describes a sudden qualitative change of the macroscopic properties mapped from the eigenspectrum of a quantum many-body system. It has been studied intensively in quantum systems with the spin-boson model, but it has barely been explored for systems in coupled spin-boson models. In this paper, we study the QPT with coupled spin-boson models consisting of coupled two-level atoms embedded in three-dimensional anisotropic photonic crystals. The dynamics of the system is derived exactly by means of the Laplace transform method, which has been proven to be equivalent to the dissipationless non-Markovian dynamics. Drawing on methods for analyzing the ground state, we obtain the phase diagrams through two exact critical equations and two QPTs are found: one QPT is that from the phase without one bound state to the phase with one bound state and another is that from one phase with the bound state having one eigenvalue to another phase where the bound state has two eigenvalues. Our analytical results also suggest a way of control to overcome the effect of decoherence by engineering the spectrum of the reservoirs to approach the non-Markovian regime and to form the bound state of the whole system for quantum devices and quantum statistics.

  1. Quantum driving of a two level system: quantum speed limit and superadiabatic protocols – an experimental investigation

    International Nuclear Information System (INIS)

    Malossi, N; Arimondo, E; Ciampini, D; Mannella, R; Bason, M G; Viteau, M; Morsch, O

    2013-01-01

    A fundamental requirement in quantum information processing and in many other areas of science is the capability of precisely controlling a quantum system by preparing a quantum state with the highest fidelity and/or in the fastest possible way. Here we present an experimental investigation of a two level system, characterized by a time-dependent Landau-Zener Hamiltonian, aiming to test general and optimal high-fidelity control protocols. The experiment is based on a Bose-Einstein condensate (BEC) loaded into an optical lattice, then accelerated, which provides a high degree of control over the experimental parameters. We implement generalized Landau-Zener sweeps, comparing them with the well-known linear Landau-Zener sweep. We drive the system from an initial state to a final state with fidelity close to unity in the shortest possible time (quantum brachistochrone), thus reaching the ultimate speed limit imposed by quantum mechanics. On the opposite extreme of the quantum control spectrum, the aim is not to minimize the total transition time but to maximize the adiabaticity during the time-evolution, the system being constrained to the adiabatic ground state at any time. We implement such transitionless superadiabatic protocols by an appropriate transformation of the Hamiltonian parameters. This transformation is general and independent of the physical system.

  2. [Remote Slit Lamp Microscope Consultation System Based on Web].

    Science.gov (United States)

    Chen, Junfa; Zhuo, Yong; Liu, Zuguo; Chen, Yanping

    2015-11-01

    To realize the remote operation of the slit lamp microscope for department of ophthalmology consultation, and visual display the real-time status of remote slit lamp microscope, a remote slit lamp microscope consultation system based on B/S structure is designed and implemented. Through framing the slit lamp microscope on the website system, the realtime acquisition and transmission of remote control and image data is realized. The three dimensional model of the slit lamp microscope is established and rendered on the web by using WebGL technology. The practical application results can well show the real-time interactive of the remote consultation system.

  3. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel

    2016-08-05

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients probability distributions are found to be highly non-Gaussian for small numbers of conduction modes, and the analytical and numerical results are in excellent agreement. The system performance is also studied, and we find that the optimum performance is obtained for half-transparent quantum dots; further, this optimum may be enhanced for systems with few conduction modes.

  4. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel; Ouerdane, Henni; Goupil, Christophe

    2016-01-01

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients probability distributions are found to be highly non-Gaussian for small numbers of conduction modes, and the analytical and numerical results are in excellent agreement. The system performance is also studied, and we find that the optimum performance is obtained for half-transparent quantum dots; further, this optimum may be enhanced for systems with few conduction modes.

  5. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom.

    Science.gov (United States)

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-Shui

    2016-06-28

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window.

  6. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    Energy Technology Data Exchange (ETDEWEB)

    Sarabi, B.; Ramanayaka, A. N. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Burin, A. L. [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States); Wellstood, F. C. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States); Osborn, K. D. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  7. Phase-controlled all-optical switching based on coherent population oscillation in a two-level system

    International Nuclear Information System (INIS)

    Liao, Ping; Yu, Song; Luo, Bin; Shen, Jing; Gu, Wanyi; Guo, Hong

    2011-01-01

    We theoretically propose a scheme of phase-controlled all-optical switching due to the effect of degenerate four-wave mixing (FWM) and coherent population oscillation (CPO) in a two-level system driven by a strong coupling field and two weak symmetrically detuned fields. The results show that the phase of the FWM field can be utilized to switch between constructive and destructive interference, which can lead to the transmission or attenuation of the probe field and thus switch the field on or off. We also find the intensity of the coupling field and the propagation distance have great influence on the performance of the switching. In our scheme, due to the quick response in semiconductor systems, a fast all-optical switching can be realized at low light level. -- Highlights: ► We study a new all-optical switching based on coherent population oscillation. ► The phase of the FWM field can be utilized to switch the probe field on or off. ► A fast and low-light-level switching can be realized in semiconductors.

  8. Dissipative two-level system under strong ac driving: A combination of Floquet and Van Vleck perturbation theory

    International Nuclear Information System (INIS)

    Hausinger, Johannes; Grifoni, Milena

    2010-01-01

    We study the dissipative dynamics of a two-level system (TLS) exposed to strong ac driving. By combining Floquet theory with Van Vleck perturbation theory in the TLS tunneling matrix element, we diagonalize the time-dependent Hamiltonian and provide corrections to the renormalized Rabi frequency of the TLS, which are valid for both a biased and unbiased TLS and go beyond the known high-frequency and rotating-wave results. In order to mimic environmental influences on the TLS, we couple the system weakly to a thermal bath and solve analytically the corresponding Floquet-Bloch-Redfield master equation. We give a closed expression for the relaxation and dephasing rates of the TLS and discuss their behavior under variation of the driving amplitude. Further, we examine the robustness of coherent destruction of tunneling (CDT) and driving-induced tunneling oscillations (DITO). We show that also for a moderate driving frequency an almost complete suppression of tunneling can be achieved for short times and demonstrate the sensitiveness of DITO to a change of the external parameters.

  9. Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters

    International Nuclear Information System (INIS)

    Maki, D.; Ishii, T.; Sato, F.; Kato, Y.; Yamamoto, T.; Iida, T.

    2011-01-01

    A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using 241 Am alpha rays. The spatial resolution of this system was ∼3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image. (authors)

  10. Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters.

    Science.gov (United States)

    Maki, Daisuke; Ishii, Tetsuya; Sato, Fuminobu; Kato, Yushi; Yamamoto, Takayoshi; Iida, Toshiyuki

    2011-03-01

    A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using (241)Am alpha rays. The spatial resolution of this system was ∼ 3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image.

  11. On the deviation from the sech2 superradiant emission law in a two-level atomic system

    International Nuclear Information System (INIS)

    Goncalves, A.E.

    1990-01-01

    The atomic superradiant emission is treated in the single particle mean field approximation. A single particle Hamiltonian, which represents a dressed two-level atom in a radiation field, can be obtained and it is verified that it describes the transient regime of the emission process. While the line shape emission for a bare atom follows the sech 2 law, for the dressed atom the line shape deviates appreciably from this law and it is verified that the deviation depends crucially on the ratio of the dynamic frequency shift to the transition frequency. This kind of deviation is observed in experimental results. (Author) [pt

  12. Microscopic functional anatomy: Integumentary system: Chapter 17

    Science.gov (United States)

    Elliott, Diane G.; Ostrander, Gary K.

    2000-01-01

    Many of the features of the fish integument can only be observed microscopically. Because there are over 20,000 living fishes, mostly higher bony fishes (teleosts), a great diversity exists in the microscopic anatomy of the integument. This chapter presents several examples from varied taxonomic groups to illustrate the variation in morphological features. As in all vertebrate epidermis, the fundamental structural unit is the epithelial cell. This is the only constant feature, as a great diversity of cell types exists in the various fish taxa. Some of these include apocrine mucous cells and a variety of other secretory cells, ionocytes, sensory cells, and wandering cells such as leukocytes. The dermis consists essentially of two sets of collagen fibers arranged in opposing geodesic spirals around the body. The dermis of most fishes is divided into two major layers. The upper (outer) layer, the stratum spongiosum or stratum laxum, is a loose network of connective tissue, whereas the lower layer, the stratum compactum, is a dense layer consisting primarily of orthogonal collagen bands. There are also specialized dermal elements such as chromatophores scales, and fin rays.

  13. Effects of phase memory in spectroscopy of test field of two level system at small frequencies of collisions

    International Nuclear Information System (INIS)

    Parkhomenko, A.I.; Shalagin, A.M.

    2006-01-01

    One studied theoretically spectrum of absorption (intensification) of a weak sounding field by two-level atoms moving in a strong resonance laser field and colliding with buffer gas atoms. The analysis was performed for the case of small frequencies of collisions in contrast to the Doppler width of absorption line (gas low pressure) with regard to the arbitrary variation of a radiation induced dipole moment phase at elastic collisions of gas particles. The effects of phase memory are found to result in very strong quantitative and qualitative transformation of a test field spectrum even in case of infrequent collisions when the well-known Dike mechanism of manifestation of phase memory effects (elimination of the Doppler widening due to limitation of spatial motion of particles by collisions) does not work. Strong influence of phase memory effects on spectral resonances at gas low pressure results from the fact that phase retaining collisions change dependence on velocity of the partial index of refraction n(v) (index of refraction for particles moving with v velocity) [ru

  14. System for sorting microscopic objects using electromagnetic radiation

    DEFF Research Database (Denmark)

    2013-01-01

    There is presented a system 10,100 for sorting microscopic objects 76, 78, 80, where the system comprises a fluid channel 66 with an inlet 68 and an outlet 70, where the fluid channel is arranged for allowing the fluid flow to be laminar. The system furthermore comprises a detection system 52 whi...

  15. Quantum physics. The bottom-up approach. From the simple two-level system to irreducible representations

    International Nuclear Information System (INIS)

    Dubbers, Dirk; Stoeckmann, Hans-Juergen

    2013-01-01

    Helps in a compact form to reach good understanding of quantum physics. Shows important analogies between problems across different disciplines. Concise and accurate, written in a readable and lively style. Concentrates on the simplest quantum system which still displays the basic features of quantum theory. Chapters end with a general outlook on multi-level systems. Results are applied to a multitude of topics in modern science, from particle physics and quantum optics to time standards and magnetic resonance imaging. This concise tutorial provides the bachelor student and the practitioner with a short text on quantum physics that allows them to understand a wealth of quantum phenomena based on a compact, well readable, yet still concise and accurate description of nonrelativistic quantum theory. This ''quadrature of the circle'' is achieved by concentrating first on the simplest quantum system that still displays all basic features of quantum theory, namely, a system with only two quantized energy levels. For most readers it is very helpful to understand such simple systems before slowly proceeding to more demanding topics like particle entanglement, quantum chaos, or the use of irreducible tensors. This tutorial does not intend to replace the standard textbooks on quantum mechanics, but will help the average student to understand them, often for the first time.

  16. Quantum physics the bottom-up approach : from the simple two-level system to irreducible representations

    CERN Document Server

    Dubbers, Dirk

    2013-01-01

    This concise tutorial provides the bachelor student and the practitioner with a short text on quantum physics that allows them to understand a wealth of quantum phenomena based on a compact, well readable, yet still concise and accurate description of nonrelativistic quantum theory. This “quadrature of the circle” is achieved by concentrating first on the simplest quantum system that still displays all basic features of quantum theory, namely, a system with only two quantized energy levels. For most readers it is very helpful to understand such simple systems before slowly proceeding to more demanding topics like particle entanglement, quantum chaos, or the use of irreducible tensors. This tutorial does not intend to replace the standard textbooks on quantum mechanics, but will help the average student to understand them, often for the first time.

  17. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    International Nuclear Information System (INIS)

    Shorikov, A. F.

    2015-01-01

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving

  18. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving.

  19. No-go theorem for one-way quantum computing on naturally occurring two-level systems

    International Nuclear Information System (INIS)

    Chen Jianxin; Chen Xie; Duan Runyao; Ji Zhengfeng; Zeng Bei

    2011-01-01

    The ground states of some many-body quantum systems can serve as resource states for the one-way quantum computing model, achieving the full power of quantum computation. Such resource states are found, for example, in spin-(5/2) and spin-(3/2) systems. It is, of course, desirable to have a natural resource state in a spin-(1/2), that is, qubit system. Here, we give a negative answer to this question for frustration-free systems with two-body interactions. In fact, it is shown to be impossible for any genuinely entangled qubit state to be a nondegenerate ground state of any two-body frustration-free Hamiltonian. What is more, we also prove that every spin-(1/2) frustration-free Hamiltonian with two-body interaction always has a ground state that is a product of single- or two-qubit states. In other words, there cannot be any interesting entanglement features in the ground state of such a qubit Hamiltonian.

  20. Entanglement criteria for microscopic-macroscopic systems

    International Nuclear Information System (INIS)

    Spagnolo, Nicolo; Vitelli, Chiara; Sciarrino, Fabio; De Martini, Francesco

    2010-01-01

    We discuss the conclusions that can be drawn on a recent experimental micro-macro entanglement test [De Martini, Sciarrino, and Vitelli, Phys. Rev. Lett. 100, 253601 (2008)]. The system under investigation is generated through optical parametric amplification of one photon belonging to an entangled pair. The adopted entanglement criterion makes it possible to infer the presence of entanglement before losses that occur on the macrostate under a specific assumption. In particular, an a priori knowledge of the system that generates the micro-macro pair is necessary to exclude a class of separable states that can reproduce the obtained experimental results. Finally, we discuss the feasibility of a micro-macro ''genuine'' entanglement test on the analyzed system by considering different strategies, which show that in principle a fraction ε, proportional to the number of photons that survive the lossy process, of the original entanglement persists in any loss regime.

  1. Integration of supercapacitive storage in renewable energy system to compare the response of two level and five level inverter with RL type load

    Science.gov (United States)

    Jana, Suman; Biswas, Pabitra Kumar; Das, Upama

    2018-04-01

    The analytical and simulation-based study in this presented paper shows a comparative report between two level inverter and five-level inverter with the integration of Supercapacitive storage in Renewable Energy system. Sometime dependent numerical models are used to measure the voltage and current response of two level and five level inverter in MATLAB Simulink based environment. In this study supercapacitive sources, which are fed by solar cells are used as input sources to experiment the response of multilevel inverter with integration of su-percapacitor as a storage device of Renewable Energy System. The RL load is used to compute the time response in MATLABSimulink based environment. With the simulation results a comparative study has been made of two different level types of inverters. Two basic types of inverter are discussed in the study with reference to their electrical behavior. It is also simulated that multilevel inverter can convert stored energy within supercapacitor which is extracted from Renewable Energy System.

  2. Generation and amplification of a high-order sideband induced by two-level atoms in a hybrid optomechanical system

    Science.gov (United States)

    Liu, Zeng-Xing; Xiong, Hao; Wu, Ying

    2018-01-01

    It is quite important to enhance and control the optomechanically induced high-order sideband generation to achieve low-power optical comb and high-sensitivity sensing with an integrable structure. Here we present and analyze a proposal for enhancement and manipulation of optical nonlinearity and high-order sideband generation in a hybrid atom-cavity optomechanical system that is coherently driven by a bichromatic input field consisting of a control field and a probe field and that works beyond the perturbative regime. Our numerical analysis with experimentally achievable parameters confirms that robust high-order sideband generation and typical spectral structures with nonperturbative features can be created even under weak driven fields. The dependence of the high-order sideband generation on the atomic parameters are also discussed in detail, including the decay rate of the atoms and the coupling parameter between the atoms and the cavity field. We show that the cutoff order as well as the amplitude of the higher-order sidebands can be well tuned by the atomic coupling strength and the atomic decay rate. The proposed mechanism of enhancing optical nonlinearity is quite general and can be adopted to optomechanical systems with different types of cavity.

  3. Probe-Hole Field Emission Microscope System Controlled by Computer

    Science.gov (United States)

    Gong, Yunming; Zeng, Haishan

    1991-09-01

    A probe-hole field emission microscope system, controlled by an Apple II computer, has been developed and operated successfully for measuring the work function of a single crystal plane. The work functions on the clean W(100) and W(111) planes are measured to be 4.67 eV and 4.45 eV, respectively.

  4. A high-resolution multimode digital microscope system.

    Science.gov (United States)

    Salmon, Edward D; Shaw, Sidney L; Waters, Jennifer C; Waterman-Storer, Clare M; Maddox, Paul S; Yeh, Elaine; Bloom, Kerry

    2013-01-01

    This chapter describes the development of a high-resolution, multimode digital imaging system based on a wide-field epifluorescent and transmitted light microscope, and a cooled charge-coupled device (CCD) camera. The three main parts of this imaging system are Nikon FXA microscope, Hamamatsu C4880 cooled CCD camera, and MetaMorph digital imaging system. This chapter presents various design criteria for the instrument and describes the major features of the microscope components-the cooled CCD camera and the MetaMorph digital imaging system. The Nikon FXA upright microscope can produce high resolution images for both epifluorescent and transmitted light illumination without switching the objective or moving the specimen. The functional aspects of the microscope set-up can be considered in terms of the imaging optics, the epi-illumination optics, the transillumination optics, the focus control, and the vibration isolation table. This instrument is somewhat specialized for microtubule and mitosis studies, and it is also applicable to a variety of problems in cellular imaging, including tracking proteins fused to the green fluorescent protein in live cells. The instrument is also valuable for correlating the assembly dynamics of individual cytoplasmic microtubules (labeled by conjugating X-rhodamine to tubulin) with the dynamics of membranes of the endoplasmic reticulum (labeled with DiOC6) and the dynamics of the cell cortex (by differential interference contrast) in migrating vertebrate epithelial cells. This imaging system also plays an important role in the analysis of mitotic mutants in the powerful yeast genetic system Saccharomyces cerevisiae. Copyright © 1998 Elsevier Inc. All rights reserved.

  5. A portable fluorescence microscopic imaging system for cholecystectomy

    Science.gov (United States)

    Ye, Jian; Yang, Chaoyu; Gan, Qi; Ma, Rong; Zhang, Zeshu; Chang, Shufang; Shao, Pengfei; Zhang, Shiwu; Liu, Chenhai; Xu, Ronald

    2016-03-01

    In this paper we proposed a portable fluorescence microscopic imaging system to prevent iatrogenic biliary injuries from occurring during cholecystectomy due to misidentification of the cystic structures. The system consisted of a light source module, a CMOS camera, a Raspberry Pi computer and a 5 inch HDMI LCD. Specifically, the light source module was composed of 690 nm and 850 nm LEDs, allowing the CMOS camera to simultaneously acquire both fluorescence and background images. The system was controlled by Raspberry Pi using Python programming with the OpenCV library under Linux. We chose Indocyanine green(ICG) as a fluorescent contrast agent and then tested fluorescence intensities of the ICG aqueous solution at different concentration levels by our fluorescence microscopic system compared with the commercial Xenogen IVIS system. The spatial resolution of the proposed fluorescence microscopic imaging system was measured by a 1951 USAF resolution target and the dynamic response was evaluated quantitatively with an automatic displacement platform. Finally, we verified the technical feasibility of the proposed system in mouse models of bile duct, performing both correct and incorrect gallbladder resection. Our experiments showed that the proposed system can provide clear visualization of the confluence between the cystic duct and common bile duct or common hepatic duct, suggesting that this is a potential method for guiding cholecystectomy. The proposed portable system only cost a total of $300, potentially promoting its use in resource-limited settings.

  6. Development of system and technology for moessbauer spectroscopic microscope

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Kazuo; Akiyama, Yuki; Tsukamoto, Yoshinori; Kurata, Mikio; Yukihira, Kenichi [Shizuoka Institute of Science and Technology (Japan); Soejima, Hiroyoshi [Shimadzu Corporation (Japan); Yoshida, Yutaka, E-mail: yoshida@ms.sist.ac.jp [Shizuoka Institute of Science and Technology (Japan)

    2012-03-15

    We have been developing a 'Moessbauer Spectroscopic Microscope (MSM)' which consists of a focusing lens for 14.4 keV {gamma}-rays and a high precision X-Y stage. The measuring system both for electrons and {gamma}-rays combined with a new Moessbauer driver, i.e., 'a moving coil actuator with a liner encoder' enables us to measure the mapping images simultaneously corresponding to different spectral components. The system has a controlling system based on a LabVIEW program and a LIST mode data acquisition system (NIKI-GLASS/A3100). To investigate a correlation between the microstructure of a sample and {sup 57}Fe atoms, a scanning electron microscope (APCO/Mini-EOC) is also installed to this system.

  7. Bridging the Gap Between the Social and the Technical: The Enrolment of Socio-Technical Information Architects to Cope with the Two-Level Model of EPR Systems.

    Science.gov (United States)

    Pedersen, Rune

    2017-01-01

    This is a project proposal derived from an urge to re-define the governance of ICT in healthcare towards regional and national standardization of the patient pathways. The focus is on a two-levelled approach for governing EPR systems where the clinicians' model structured variables and patient pathways. The overall goal is a patient centric EPR portfolio. This paper define and enlighten the need for establishing the socio- technical architect role necessary to obtain the capabilities of a modern structured EPR system. Clinicians are not capable to moderate between the technical and the clinical.

  8. New Aspects of Field Entropy Squeezing as an Indicator for Mixed State Entanglement in an Effective Two-Level System with Stark Shift

    Institute of Scientific and Technical Information of China (English)

    S.Abdel-Khalek; M.M.A.Ahmed; A-S F.Obada

    2011-01-01

    We present an effective two-level system in interaction through two-photon processes with a single mode quantized electromagnetic field,initially prepared in a coherent state.Field entropy squeezing as an indicator of the entanglement in a mixed state system is suggested.The temporal evolution of the negativity,Wehrl entropy,Wehrl phase distribution and field entropy squeezing are investigated.The results highlight the important roles played by both the Stark shift parameters and the mixed state setting in the dynamics of the Wehrl entropy,Wehrl phase distribution and field entropy squeezing.%We present an effective two-level system in interaction through two-photon processes with a single mode quantized electromagnetic Reid, initially prepared in a coherent state. Field entropy squeezing as an indicator of the entanglement in a mixed state system is suggested. The temporal evolution of the negativity, Wehrl entropy, Wehrl phase distribution and field entropy squeezing are investigated. The results highlight the important roles played by both the Stark shift parameters and the mixed state setting in the dynamics of the Wehrl entropy, Wehrl phase distribution and field entropy squeezing.

  9. Power and polarization dependences of ultra-narrow electromagnetically induced absorption (EIA) spectra of 85 Rb atoms in degenerate two-level system

    Science.gov (United States)

    Qureshi, Muhammad Mohsin; Rehman, Hafeez Ur; Noh, Heung-Ryoul; Kim, Jin-Tae

    2016-05-01

    We have investigated ultra-narrow EIA spectral features with respect to variations of polarizations and powers of pump laser beam in a degenerate two-level system of the transition of 85 Rb D2 transition line. Polarizations of the probe laser beam in two separate experiments were fixed at right circular and horizontal linear polarizations, respectively while the polarizations of the pump lasers were varied from initial polarizations same as the probe laser beams to orthogonal to probe polarizations. One homemade laser combined with AOMs was used to the pump and probe laser beams instead of two different lasers to overcome broad linewidths of the homemade lasers. Theoretically, probe absorption coefficients have been calculated from optical Bloch equations of the degenerate two level system prepared by a pump laser beam. In the case of the circular polarization, EIA signal was obtained as expected theoretically although both pump and probe beams have same polarization. The EIA signal become smaller as power increases and polarizations of the pump and probe beams were same. When the polarization of the pump beam was linear polarization, maximum EIA signal was obtained theoretically and experimentally. Experimental EIA spectral shapes with respect to variations of the pump beam polarization shows similar trends as the theoretical results.

  10. On microscopic simulations of systems with model chemical reactions

    International Nuclear Information System (INIS)

    Gorecki, J.; Gorecka, J.N.

    1998-01-01

    Large scale computer simulations of model chemical systems play the role of idealized experiments in which theories may be tested. In this paper we present two applications of microscopic simulations based on the reactive hard sphere model. We investigate the influence of internal fluctuations on an oscillating chemical system and observe how they modify the phase portrait of it. Another application, we consider, is concerned with the propagation of a chemical wave front associated with a thermally activated reaction. It is shown that the nonequilibrium effects increase the front velocity if compared with the velocity of the front generated by a nonactivated process characterized by the same rate constant. (author)

  11. Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

    KAUST Repository

    Yukawa, Satoshi

    2009-02-15

    A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

  12. Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

    KAUST Repository

    Yukawa, Satoshi; Shimada, Takashi; Ogushi, Fumiko; Ito, Nobuyasu

    2009-01-01

    A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

  13. Microscopic Electron Dynamics in Metal Nanoparticles for Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Katarzyna Kluczyk

    2018-06-01

    Full Text Available Nanoparticles—regularly patterned or randomly dispersed—are a key ingredient for emerging technologies in photonics. Of particular interest are scattering and field enhancement effects of metal nanoparticles for energy harvesting and converting systems. An often neglected aspect in the modeling of nanoparticles are light interaction effects at the ultimate nanoscale beyond classical electrodynamics. Those arise from microscopic electron dynamics in confined systems, the accelerated motion in the plasmon oscillation and the quantum nature of the free electron gas in metals, such as Coulomb repulsion and electron diffusion. We give a detailed account on free electron phenomena in metal nanoparticles and discuss analytic expressions stemming from microscopic (Random Phase Approximation—RPA and semi-classical (hydrodynamic theories. These can be incorporated into standard computational schemes to produce more reliable results on the optical properties of metal nanoparticles. We combine these solutions into a single framework and study systematically their joint impact on isolated Au, Ag, and Al nanoparticles as well as dimer structures. The spectral position of the plasmon resonance and its broadening as well as local field enhancement show an intriguing dependence on the particle size due to the relevance of additional damping channels.

  14. Radiative heat transfer in low-dimensional systems -- microscopic mode

    Science.gov (United States)

    Woods, Lilia; Phan, Anh; Drosdoff, David

    2013-03-01

    Radiative heat transfer between objects can increase dramatically at sub-wavelength scales. Exploring ways to modulate such transport between nano-systems is a key issue from fundamental and applied points of view. We advance the theoretical understanding of radiative heat transfer between nano-objects by introducing a microscopic model, which takes into account the individual atoms and their atomic polarizabilities. This approach is especially useful to investigate nano-objects with various geometries and give a detailed description of the heat transfer distribution. We employ this model to study the heat exchange in graphene nanoribbon/substrate systems. Our results for the distance separations, substrates, and presence of extended or localized defects enable making predictions for tailoring the radiative heat transfer at the nanoscale. Financial support from the Department of Energy under Contract No. DE-FG02-06ER46297 is acknowledged.

  15. Braking system for use with an arbor of a microscope

    International Nuclear Information System (INIS)

    Norgren, D.U.

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location

  16. Braking system for use with an arbor of a microscope

    Science.gov (United States)

    Norgren, Duane U.

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  17. Optimal Design of Integrated Systems Health Management (ISHM) Systems for improving safety in NASA's Exploration Vehicles: A Two-Level Multidisciplinary Design Approach

    Science.gov (United States)

    Mehr, Ali Farhang; Tumer, Irem; Barszcz, Eric

    2005-01-01

    Integrated Vehicle Health Management (ISHM) systems are used to detect, assess, and isolate functional failures in order to improve safety of space systems such as Orbital Space Planes (OSPs). An ISHM system, as a whole, consists of several subsystems that monitor different components of an OSP including: Spacecraft, Launch Vehicle, Ground Control, and the International Space Station. In this research, therefore, we propose a new methodology to design and optimize ISHM as a distributed system with multiple disciplines (that correspond to different subsystems of OSP safety). A paramount amount of interest has been given in the literature to the multidisciplinary design optimization of problems with such architecture (as will be reviewed in the full paper).

  18. Modeling the dynamics of multipartite quantum systems created departing from two-level systems using general local and non-local interactions

    Science.gov (United States)

    Delgado, Francisco

    2017-12-01

    Quantum information is an emergent area merging physics, mathematics, computer science and engineering. To reach its technological goals, it is requiring adequate approaches to understand how to combine physical restrictions, computational approaches and technological requirements to get functional universal quantum information processing. This work presents the modeling and the analysis of certain general type of Hamiltonian representing several physical systems used in quantum information and establishing a dynamics reduction in a natural grammar for bipartite processing based on entangled states.

  19. Optical design and system characterization of an imaging microscope at 121.6 nm

    Science.gov (United States)

    Gao, Weichuan; Finan, Emily; Kim, Geon-Hee; Kim, Youngsik; Milster, Thomas D.

    2018-03-01

    We present the optical design and system characterization of an imaging microscope prototype at 121.6 nm. System engineering processes are demonstrated through the construction of a Schwarzschild microscope objective, including tolerance analysis, fabrication, alignment, and testing. Further improvements on the as-built system with a correction phase plate are proposed and analyzed. Finally, the microscope assembly and the imaging properties of the prototype are demonstrated.

  20. Microscopic dynamics of binary mixtures and quasi-colloidal systems

    International Nuclear Information System (INIS)

    Smorenburg, H.E.

    1996-01-01

    In the study on the title subject two questions are addressed. One is whether the microscopic dynamics of binary mixtures and quasi-colloidal systems can be understood theoretically with kinetic theories for equivalent hard sphere mixtures. The other question that arises is whether the similarity in the dynamics of dense simple fluids and concentrated colloidal suspensions also holds for binary mixtures and quasi-colloidal systems. To answer these questions, we have investigated a number of binary gas mixtures and quasi-colloidal system with different diameter ratios and concentrations. We obtain the experimental dynamic structure factors S expt (κ,ω) of the samples from inelastic neutron scattering. We compare S expt (κ,ω) with the dynamic structure S HS (κ,ω) of an equivalent hard sphere fluid, that we calculate with the Enskog theory. In chapter 2, 3 and 4 we study dense He-Ar gas mixtures (diameter ratio R=1.4, and mass ratio M=10) at low and high Ar concentrations. Experiment and kinetic theory are in good agreement. In chapter 5 we study dilute quasi-colloidal suspensions of fullerene C60 molecules dissolved in liquid CS2. The diameter ratio R=2.2 is larger than in previous experiments while the mass ratio M=9.5 is more or less the same. We obtain the self diffusion coefficient D S of one C60 molecule in CS2 and find D s ≤D SE ≤D E , with D E obtained from kinetic theory and D SE from the Stokes-Einstein description. It appears that both descriptions are relevant but not so accurate. In chapter 6 we study three dense mixtures of neopentane in 40 Ar (diameter ratio R=1.7, mass ratio M=2) at low and high neopentane concentrations. At low concentration, we find a diffusion coefficient of neopentane in Ar, which is in good agreement with kinetic theory and in moderate agreement with the Stokes-Einstein description. At high concentration the collective translational dynamics of neopentane shows a similar behaviour as in dense colloids and simple fluids

  1. Frequency division multiplexed multi-color fluorescence microscope system

    Science.gov (United States)

    Le, Vu Nam; Yang, Huai Dong; Zhang, Si Chun; Zhang, Xin Rong; Jin, Guo Fan

    2017-10-01

    Grayscale camera can only obtain gray scale image of object, while the multicolor imaging technology can obtain the color information to distinguish the sample structures which have the same shapes but in different colors. In fluorescence microscopy, the current method of multicolor imaging are flawed. Problem of these method is affecting the efficiency of fluorescence imaging, reducing the sampling rate of CCD etc. In this paper, we propose a novel multiple color fluorescence microscopy imaging method which based on the Frequency division multiplexing (FDM) technology, by modulating the excitation lights and demodulating the fluorescence signal in frequency domain. This method uses periodic functions with different frequency to modulate amplitude of each excitation lights, and then combine these beams for illumination in a fluorescence microscopy imaging system. The imaging system will detect a multicolor fluorescence image by a grayscale camera. During the data processing, the signal obtained by each pixel of the camera will be processed with discrete Fourier transform, decomposed by color in the frequency domain and then used inverse discrete Fourier transform. After using this process for signals from all of the pixels, monochrome images of each color on the image plane can be obtained and multicolor image is also acquired. Based on this method, this paper has constructed and set up a two-color fluorescence microscope system with two excitation wavelengths of 488 nm and 639 nm. By using this system to observe the linearly movement of two kinds of fluorescent microspheres, after the data processing, we obtain a two-color fluorescence dynamic video which is consistent with the original image. This experiment shows that the dynamic phenomenon of multicolor fluorescent biological samples can be generally observed by this method. Compared with the current methods, this method can obtain the image signals of each color at the same time, and the color video's frame

  2. Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems.

    Science.gov (United States)

    Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David

    2015-08-01

    To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

  3. A Microscopic Optically Tracking Navigation System That Uses High-resolution 3D Computer Graphics.

    Science.gov (United States)

    Yoshino, Masanori; Saito, Toki; Kin, Taichi; Nakagawa, Daichi; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

    2015-01-01

    Three-dimensional (3D) computer graphics (CG) are useful for preoperative planning of neurosurgical operations. However, application of 3D CG to intraoperative navigation is not widespread because existing commercial operative navigation systems do not show 3D CG in sufficient detail. We have developed a microscopic optically tracking navigation system that uses high-resolution 3D CG. This article presents the technical details of our microscopic optically tracking navigation system. Our navigation system consists of three components: the operative microscope, registration, and the image display system. An optical tracker was attached to the microscope to monitor the position and attitude of the microscope in real time; point-pair registration was used to register the operation room coordinate system, and the image coordinate system; and the image display system showed the 3D CG image in the field-of-view of the microscope. Ten neurosurgeons (seven males, two females; mean age 32.9 years) participated in an experiment to assess the accuracy of this system using a phantom model. Accuracy of our system was compared with the commercial system. The 3D CG provided by the navigation system coincided well with the operative scene under the microscope. Target registration error for our system was 2.9 ± 1.9 mm. Our navigation system provides a clear image of the operation position and the surrounding structures. Systems like this may reduce intraoperative complications.

  4. Aiming of Kirkpatrick-Baez microscope based on auxiliary optical system

    International Nuclear Information System (INIS)

    Huang Shengling; Mu Baozhong; Yi Shengzhen; Wang Xin; Wang Zhanshan; Ding Yongkun; Miao Wenyong; Dong Jianjun

    2009-01-01

    An auxiliary optical system has been designed, which can provide precise positioning for aiming Kirkpatrick-Baez (KB) microscope object location. An 8 keV X-ray imaging system by KB microscope with periodic multilayer films has been designed. The field of view and depth of field in the resolution of 5 μm are got, and then the corresponding point and depth of field in diagnostic experiments are calculated. Based on the object-image relations and precision of the KB microscope, an auxiliary visible light imaging system is designed and X-ray imaging experiments are performed, which can achieve equivalent aiming between the visible imaging system and the KB microscope. The results show that ±20 μm vertical axis plane and ±300 μm axial accuracy are achieved through the auxiliary optical path, which can meet the object point positioning requirements of the KB microscope. (authors)

  5. Towards Realization of Intelligent Medical Treatment at Nanoscale by Artificial Microscopic Swarm Control Systems

    Directory of Open Access Journals (Sweden)

    Alireza Rowhanimanesh

    2017-07-01

    Full Text Available Background: In this paper, the novel concept of artificial microscopic swarm control systems is proposed as a promising approach towards realization of intelligent medical treatment at nanoscale. In this new paradigm, treatment is done autonomously at nanoscale within the patient’s body by the proposed swarm control systems.Methods: From control engineering perspective, medical treatment can be considered as a control problem, in which the ultimate goal is to find the best feasible way to change the state of diseased tissue from unhealthy to healthy in presence of uncertainty. Although a living tissue is a huge swarm of microscopic cells, nearly all of the common treatment methods are based on macroscopic centralized control paradigm. Inspired by natural microscopic swarm control systems such as nervous, endocrine and immune systems that work based on swarm control paradigm, medical treatment needs a paradigm shift from macroscopic centralized control to microscopic swarm control. An artificial microscopic swarm control system consists of a huge number of very simple autonomous microscopic agents that exploit swarm intelligence to realize sense, control (computing and actuation at nanoscale in local, distributed and decentralized manner. This control system can be designed based on mathematical analysis and computer simulation.Results: The proposed approach is used for treatment of atherosclerosis and cancer based on mathematical analysis and in-silico study.Conclusion: The notion of artificial microscopic swarm control systems opens new doors towards realization of autonomous and intelligent medical treatment at nanoscale within the patient’s body.

  6. Quantum description of microscopic and macroscopic systems: Old problems and recent investigations

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1986-04-01

    We review some open problems and some proposed solutions which are encountered in the quantum description of the microscopic systems, of the macroscopic ones, and of the interactions between these two types of objects. We describe a recent attempt allowing a unified description of all phenomena, reproducing the quantum mechanical situation for microscopic systems and inducing in a completely consistent way the classical behaviour of macro object and the phenomena of wave packet reduction in the system-apparatus interaction. (author)

  7. A two-level voltage source inverter with differentially sinusoidal pulse width modulation used in the interconnection system of a wind turbine generator

    Directory of Open Access Journals (Sweden)

    Alexandros C. Charalampidis

    2014-10-01

    Full Text Available This study analyses an interconnection system based on differentially sinusoidal pulse width modulation, used for the interconnection to the grid of a variable speed wind turbine. The modulation technique used provides specific advantages in comparison with the commonly used sinusoidal pulse width modulation (SPWM technique, such as lower DC bus voltage requirements, smaller switching losses for the same switching frequency as well as less higher harmonic content in the voltage waveforms produced. The respective control system is also described in detail. Thus this study provides a guide enabling the design of any interconnection system based on this modulation technique.

  8. Development of an integrated model for energy systems planning and carbon dioxide mitigation under uncertainty - Tradeoffs between two-level decision makers.

    Science.gov (United States)

    Jin, S W; Li, Y P; Xu, L P

    2018-07-01

    A bi-level fuzzy programming (BFLP) method was developed for energy systems planning (ESP) and carbon dioxide (CO 2 ) mitigation under uncertainty. BFLP could handle fuzzy information and leader-follower problem in decision-making processes. It could also address the tradeoffs among different decision makers in two decision-making levels through prioritizing the most important goal. Then, a BFLP-ESP model was formulated for planning energy system of Beijing, in which the upper-level objective is to minimize CO 2 emission and the lower-level objective is to minimize the system cost. Results provided a range of decision alternatives that corresponded to a tradeoff between system optimality and reliability under uncertainty. Compared to the single-level model with a target to minimize system cost, the amounts of pollutant/CO 2 emissions from BFLP-ESP were reduced since the study system would prefer more clean energies (i.e. natural gas, LPG and electricity) to replace coal fuel. Decision alternatives from BFLP were more beneficial for supporting Beijing to adjust its energy mix and enact its emission-abatement policy. Results also revealed that the low-carbon policy for power plants (e.g., shutting down all coal-fired power plants) could lead to a potentially increment of imported energy for Beijing, which would increase the risk of energy shortage. The findings could help decision makers analyze the interactions between different stakeholders in ESP and provide useful information for policy design under uncertainty. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. A high-resolution mini-microscope system for wireless real-time monitoring.

    Science.gov (United States)

    Wang, Zongjie; Boddeda, Akash; Parker, Benjamin; Samanipour, Roya; Ghosh, Sanjoy; Menard, Frederic; Kim, Keekyoung

    2017-09-04

    Compact, cost-effective and high-performance microscope that enables the real-time imaging of cells and lab-on-a-chip devices is highly demanded for cell biology and biomedical engineering. This paper aims to present the design and application of an inexpensive wireless mini-microscope with resolution up to 2592 × 1944 pixels and speed up to 90 fps. The mini-microscope system was built on a commercial embedded system (Raspberry Pi). We modified a camera module and adopted an inverse dual lens system to obtain the clear field of view and appropriate magnification for tens of micrometer objects. The system was capable of capturing time-lapse images and transferring image data wirelessly. The entire system can be operated wirelessly and cordlessly in a conventional cell culturing incubator. The developed mini-microscope was used to monitor the attachment and proliferation of NIH-3T3 and HEK 293 cells inside an incubator for 50 hours. In addition, the mini-microscope was used to monitor a droplet generation process in a microfluidic device. The high-quality images captured by the mini-microscope enabled us an automated analysis of experimental parameters. The successful applications prove the great potential of the developed mini-microscope for monitoring various biological samples and microfluidic devices. This paper presents the design of a high resolution mini-microscope system that enables the wireless real-time imaging of cells inside the incubator. This system has been verified to be a useful tool to obtain high-quality images and videos for the automated quantitative analysis of biological samples and lab-on-a-chip devices in the long term.

  10. The Two-Level Theory of verb meaning: An approach to integrating the semantics of action with the mirror neuron system.

    Science.gov (United States)

    Kemmerer, David; Gonzalez-Castillo, Javier

    2010-01-01

    Verbs have two separate levels of meaning. One level reflects the uniqueness of every verb and is called the "root". The other level consists of a more austere representation that is shared by all the verbs in a given class and is called the "event structure template". We explore the following hypotheses about how, with specific reference to the motor features of action verbs, these two distinct levels of semantic representation might correspond to two distinct levels of the mirror neuron system. Hypothesis 1: Root-level motor features of verb meaning are partially subserved by somatotopically mapped mirror neurons in the left primary motor and/or premotor cortices. Hypothesis 2: Template-level motor features of verb meaning are partially subserved by representationally more schematic mirror neurons in Brodmann area 44 of the left inferior frontal gyrus. Evidence has been accumulating in support of the general neuroanatomical claims made by these two hypotheses-namely, that each level of verb meaning is associated with the designated cortical areas. However, as yet no studies have satisfied all the criteria necessary to support the more specific neurobiological claims made by the two hypotheses-namely, that each level of verb meaning is associated with mirror neurons in the pertinent brain regions. This would require demonstrating that within those regions the same neuronal populations are engaged during (a) the linguistic processing of particular motor features of verb meaning, (b) the execution of actions with the corresponding motor features, and (c) the observation of actions with the corresponding motor features. 2008 Elsevier Inc. All rights reserved.

  11. Microscopic origins of charge transport in triphenylene systems

    Science.gov (United States)

    Thompson, Ian R.; Coe, Mary K.; Walker, Alison B.; Ricci, Matteo; Roscioni, Otello M.; Zannoni, Claudio

    2018-06-01

    We study the effects of molecular ordering on charge transport at the mesoscale level in a layer of ≈9000 hexa-octyl-thio-triphenylene discotic mesogens with dimensions of ≈20 ×20 ×60 nm3 . Ordered (columnar) and disordered isotropic morphologies are obtained from a combination of atomistic and coarse-grained molecular-dynamics simulations. Electronic structure codes are used to find charge hopping rates at the microscopic level. Energetic disorder is included through the Thole model. Kinetic Monte Carlo simulations then predict charge mobilities. We reproduce the large increase in mobility in going from an isotropic to a columnar morphology. To understand how these mobilities depend on the morphology and hopping rates, we employ graph theory to analyze charge trajectories by representing the film as a charge-transport network. This approach allows us to identify spatial correlations of molecule pairs with high transfer rates. These pairs must be linked to ensure good transport characteristics or may otherwise act as traps. Our analysis is straightforward to implement and will be a useful tool in linking materials to device performance, for example, to investigate the influence of local inhomogeneities in the current density. Our mobility-field curves show an increasing mobility with field, as would be expected for an organic semiconductor.

  12. Lateral resolution testing of a novel developed confocal microscopic imaging system

    Science.gov (United States)

    Zhang, Xin; Zhang, Yunhai; Chang, Jian; Huang, Wei; Xue, Xiaojun; Xiao, Yun

    2015-10-01

    Laser scanning confocal microscope has been widely used in biology, medicine and material science owing to its advantages of high resolution and tomographic imaging. Based on a set of confirmatory experiments and system design, a novel confocal microscopic imaging system is developed. The system is composed of a conventional fluorescence microscope and a confocal scanning unit. In the scanning unit a laser beam coupling module provides four different wavelengths 405nm 488nm 561nm and 638nm which can excite a variety of dyes. The system works in spot-to-spot scanning mode with a two-dimensional galvanometer. A 50 microns pinhole is used to guarantee that stray light is blocked and only the fluorescence signal from the focal point can be received . The three-channel spectral splitter is used to perform fluorescence imaging at three different working wavelengths simultaneously. The rat kidney tissue slice is imaged using the developed confocal microscopic imaging system. Nucleues labeled by DAPI and kidney spherule curved pipe labeled by Alexa Fluor 488 can be imaged clearly and respectively, realizing the distinction between the different components of mouse kidney tissue. The three-dimensional tomographic imaging of mouse kidney tissue is reconstructed by several two-dimensional images obtained in different depths. At last the resolution of the confocal microscopic imaging system is tested quantitatively. The experimental result shows that the system can achieve lateral resolution priority to 230nm.

  13. Multi-wavelength study of PPDs using an OPO tunable pulse laser microscope system

    International Nuclear Information System (INIS)

    Yoshimura, Koji; Nakamura, Isamu

    2012-01-01

    We have developed a new pulsed laser microscope system whose wavelength is continuously tunable from 410 nm to 2200 nm by using an optical parametric oscillator (OPO) laser system. The laser spot can be focused to ∼2μm diameter, small enough to measure pixel-by-pixel performance of PPDs (pixelated photon detectors). Using multi-wavelength laser light, we plan to probe PPDs at various depths, thanks to their different penetration lengths in the silicon layer. In this paper, details of the commissioning of the laser microscope system and pilot measurements on a PPD at several wavelengths will be presented.

  14. Multi-wavelength study of PPDs using an OPO tunable pulse laser microscope system

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Koji, E-mail: koji.yoshimura@kek.jp [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nakamura, Isamu [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2012-12-11

    We have developed a new pulsed laser microscope system whose wavelength is continuously tunable from 410 nm to 2200 nm by using an optical parametric oscillator (OPO) laser system. The laser spot can be focused to {approx}2{mu}m diameter, small enough to measure pixel-by-pixel performance of PPDs (pixelated photon detectors). Using multi-wavelength laser light, we plan to probe PPDs at various depths, thanks to their different penetration lengths in the silicon layer. In this paper, details of the commissioning of the laser microscope system and pilot measurements on a PPD at several wavelengths will be presented.

  15. Development of a fluorescent microscope combined with a real-time autoradiography system

    International Nuclear Information System (INIS)

    Rai, Hiroki; Kanno, Satomi; Hayashi, Yoshitake; Nihei, Naoto; Nakanishi, Tomoko M.

    2008-01-01

    For combination with microscope, we developed real-time autoradiography system for micro-scale analysis with adjustment of the CsI(Ti) scintillator thickness for higher resolution and applying tapered fiber optic plate for magnification of autoradiograph image. We combined real-time autoradiography system with an inverted fluorescent microscope so that an autoradiograph image as well as fluorescent image, bright-field image can be acquired at the same time. In the case of observation of sliced soybean stalk traced 45 CaCl, the fluorescent and bright-field image was acquired which magnified to 50 times, the autoradiograph image of 45 Ca distribution in the tissue was acquired in almost same scale. The new microscopic system which can acquire autoradiograph image of labeled signals (low molecular weight) is expected to develop the signal transduction study and gene expression, combined with fluorescent protein techniques such as GFP etc. (author)

  16. Microscopic Fermi liquid approach to disordered narrow band systems

    International Nuclear Information System (INIS)

    Kolley, E.; Kolley, W.

    1977-01-01

    A Fermi liquid approach to tightly bound electrons in disordered systems is proposed to evaluate two-particle correlation functions L at T=0 deg K. Starting with a random Hubbard model and using a local ladder approximation in the particle-particle channel the irreducible particle-hole vertex is derived, being the kernel of the Bethe-Salpeter equation for L. CPA vertex corrections to the electrical conductivity and, for the ordered case, the correlation-enhanced paramagnetic susceptibility are calculated

  17. Dual ion beam irradiation system for in situ observation with electron microscope

    International Nuclear Information System (INIS)

    Tsukamoto, Tetuo; Hojou, Kiiti; Furuno, Sigemi; Otsu, Hitosi; Izui, Kazuhiko.

    1993-01-01

    We have developed a new in situ observation system for dynamic processes under dual ion beam irradiation. The system consists of a modified 400 keV analytical electron microscope (JEOL, JEM-4000FX) and two 40 kV ion beam accelerators. This system allows evaluation of microscopic changes of structure and chemical bonding state of materials in the dynamic processes under two kinds of ion beam irradiations, that is required for the simulation test of the first wall of nuclear fusion reactors onto which He + , H + , and H 2 + ions are irradiated simultaneously. These two ion accelerators were equipped symmetrically both sides of the electron microscope and individually controlled. Each ion beam extracted from a duo-plasmatron ion gun is bent downward by an angle of 30deg with a mass-separating magnet, and introduced into specimen chamber of the electron microscope. Inside the specimen chamber the beam is deflected again by an angle of 30deg with an electrostatic prism so as to be incident on the specimen surface. Finally, two ion beams from both side are incident on the specimen surface at an angle of 60deg. The maximum ion current density of helium is more than 250μA/cm 2 at the specimen at an ion energy of 17 keV. Images of the electron microscope during dual ion beam irradiation are observed through a TV camera and recorded with a VTR. (author)

  18. Microscopic energy flows in disordered Ising spin systems

    International Nuclear Information System (INIS)

    Agliari, E; Casartelli, M; Vezzani, A

    2010-01-01

    An efficient microcanonical dynamics has been recently introduced for Ising spin models embedded in a generic connected graph even in the presence of disorder, i.e. with the spin couplings chosen from a random distribution. Such a dynamics allows a coherent definition of local temperatures also when open boundaries are coupled to thermostats, imposing an energy flow. Within this framework, here we introduce a consistent definition for local energy currents and we study their dependence on the disorder. In the linear response regime, when the global gradient between thermostats is small, we also define local conductivities following a Fourier discretized picture. Then, we work out a linearized 'mean-field approximation', where local conductivities are supposed to depend on local couplings and temperatures only. We compare the approximated currents with the exact results of the nonlinear system, showing the reliability range of the mean-field approach, which proves very good at high temperatures and not so efficient in the critical region. In the numerical studies we focus on the disordered cylinder but our results could be extended to an arbitrary, disordered spin model on generic discrete structures

  19. Evolution of Quantum Systems from Microscopic to Macroscopic Scales

    International Nuclear Information System (INIS)

    Ovchinnikov, Sergey Y.; Macek, Joseph H.; Sternberg, James S.; Lee, Teck-Ghee; Schultz, David R.

    2009-01-01

    Even though the static properties of quantum systems have been known since the early days of quantum mechanics, accurate simulation of the dynamical break-up or ionization remains a theoretical challenge despite our complete knowledge of the relevant interactions. Simulations are challenging because of highly oscillatory exponential phase factors in the electronic wave function and the infinitesimally small values of the continuum components of electronic probability density at large times after the collision. The approach we recently developed, the regularized time-dependent Schroedinger equation method, has addressed these difficulties by removing the diverging phase factors and transforming the time-dependent Schroedinger equation to an expanding space. The evolution of the electronic wave function was followed to internuclear distances of R = 100,000 a.u. or 5 microns, which is of the order of the diameter of a human hair. Our calculations also revealed unexpected presence of free vortices in the electronic wave function. The discovered vortices also bring new light on the mechanism of transferring of the angular momentum from an external to internal motion. The connection between the observable momentum distribution and the time-dependent wave function implies that vortices in the wave function at large times are imaged in the momentum distribution.

  20. Evolution of the field quantum entropy and entanglement in a system of multimode light field interacting resonantly with a two-level atom through N_j-degenerate N~Σ-photon process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The time evolution of the field quantum entropy and entanglement in a system of multi-mode coherent light field resonantly interacting with a two-level atom by de-generating the multi-photon process is studied by utilizing the Von Neumann re-duced entropy theory,and the analytical expressions of the quantum entropy of the multimode field and the numerical calculation results for three-mode field inter-acting with the atom are obtained. Our attention focuses on the discussion of the influences of the initial average photon number,the atomic distribution angle and the phase angle of the atom dipole on the evolution of the quantum field entropy and entanglement. The results obtained from the numerical calculation indicate that: the stronger the quantum field is,the weaker the entanglement between the quan-tum field and the atom will be,and when the field is strong enough,the two sub-systems may be in a disentangled state all the time; the quantum field entropy is strongly dependent on the atomic distribution angle,namely,the quantum field and the two-level atom are always in the entangled state,and are nearly stable at maximum entanglement after a short time of vibration; the larger the atomic dis-tribution angle is,the shorter the time for the field quantum entropy to evolve its maximum value is; the phase angles of the atom dipole almost have no influences on the entanglement between the quantum field and the two-level atom. Entangled states or pure states based on these properties of the field quantum entropy can be prepared.

  1. APPLICATION OF SCANNING ELECTRON MICROSCOPE EQUIPPED WITH THE MICROANALYSIS SYSTEM FOR INVESTIGATION OF BRASS COVERING

    Directory of Open Access Journals (Sweden)

    T. P. Kurenkova

    2010-01-01

    Full Text Available The possibilities of application of scanning electronic microscope equipped with microanalysis system for investigation of the brass covering quality by slug for production of wire and metal cord particularly of change of copper concentration by covering thickness and slug perimeter, revealing of ?-phase allocation presence and character, determination of defect reasons, are shown.

  2. The system of digital-image optical microscope in semiconductor particle detector development

    International Nuclear Information System (INIS)

    Han Lixiang; Li Zhankui; Jin Genming; Wang Zhusheng; Xiao Guoqing

    2009-01-01

    Optical microscopic detection is very important in the process of semiconductor particle detector development. A system of digital-image optical microscope has been constructed with rather low price, which performance is comparable with the moderate-level imports. The system mounts powerful dry objective, and a 2μm resolution could be achieved. Observations with bright and dark field, polarized light,and interference light can be carried out on it. The system have large area on-line monitor,and the photographic device can be controlled by PC. It can be used in the control of defects and contaminations, pattern test, identification of crystal backing, inspection of the smoothness and the flatness of the crystal surface. It can also be used in some precise procedures, such as test, assembly, packaging and repairing. The quality of the bond could be examined by observing the appearance of the bond point and the microscopic structure of the solder. The surface fluctuation can be precisely measured under the microscope with the technology of multi-beam interference. In the article, the application of this system for semiconductor particle detector development has been illustrated, and the construction information has been described in detail. (authors)

  3. Nonequilibrium Distribution of the Microscopic Thermal Current in Steady Thermal Transport Systems

    KAUST Repository

    Yukawa, Satoshi; Ogushi, Fumiko; Shimada, Takashi; Ito, Nobuyasu

    2010-01-01

    Nonequilibrium distribution of the microscopic thermal current is investigated by direct molecular dynamics simulations. The microscopic thermal current in this study is defined by a flow of kinetic energy carried by a single particle. Asymptotic parallel and antiparallel tails of the nonequilibrium distribution to an average thermal current are identical to ones of equilibrium distribution with different temperatures. These temperatures characterizing the tails are dependent on a characteristic length in which a memory of dynamics is completely erased by several particle collisions. This property of the tails of nonequilibrium distribution is confirmed in other thermal transport systems. In addition, statistical properties of a particle trapped by a harmonic potential in a steady thermal conducting state are also studied. This particle feels a finite force parallel to the average thermal current as a consequence of the skewness of the distribution of the current. This force is interpreted as the microscopic origin of thermophoresis.

  4. Features and states of microscopic particles in nonlinear quantum-mechanics systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,we present the elementary principles of nonlinear quantum mechanics(NLQM),which is based on some problems in quantum mechanics.We investigate in detail the motion laws and some main properties of microscopic particles in nonlinear quantum systems using these elementary principles.Concretely speaking,we study in this paper the wave-particle duality of the solution of the nonlinear Schr6dinger equation,the stability of microscopic particles described by NLQM,invariances and conservation laws of motion of particles,the Hamiltonian principle of particle motion and corresponding Lagrangian and Hamilton equations,the classical rule of microscopic particle motion,the mechanism and rules of particle collision,the features of reflection and the transmission of particles at interfaces,and the uncertainty relation of particle motion as well as the eigenvalue and eigenequations of particles,and so on.We obtained the invariance and conservation laws of mass,energy and momentum and angular momenturn for the microscopic particles,which are also some elementary and universal laws of matter in the NLQM and give further the methods and ways of solving the above questions.We also find that the laws of motion of microscopic particles in such a case are completely different from that in the linear quantum mechanics(LQM).They have a lot of new properties;for example,the particles possess the real wave-corpuscle duality,obey the classical rule of motion and conservation laws of energy,momentum and mass,satisfy minimum uncertainty relation,can be localized due to the nonlinear interaction,and its position and momentum can also be determined,etc.From these studies,we see clearly that rules and features of microscopic particle motion in NLQM is different from that in LQM.Therefore,the NLQM is a new physical theory,and a necessary result of the development of quantum mechanics and has a correct representation of describing microscopic particles in nonlinear systems,which can

  5. Electronic zooming TV readout system for an x-ray microscope

    International Nuclear Information System (INIS)

    Kinoshita, K.; Matsumura, T.; Inagaki, Y.; Hirai, N.; Sugiyama, M.; Kihara, H.; Watanabe, N.; Shimanuki, Y.

    1993-01-01

    The electronic zooming TV readout system using the X-ray zooming tube has been developed for purposes of real-time readout of very high resolution X-ray image, e.g. the output image from an X-ray microscope. The system limiting resolution is 0.2∼0.3 μm and it is easy to operate in practical applications

  6. Two-Level Semantics and Code Generation

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1988-01-01

    A two-level denotational metalanguage that is suitable for defining the semantics of Pascal-like languages is presented. The two levels allow for an explicit distinction between computations taking place at compile-time and computations taking place at run-time. While this distinction is perhaps...... not absolutely necessary for describing the input-output semantics of programming languages, it is necessary when issues such as data flow analysis and code generation are considered. For an example stack-machine, the authors show how to generate code for the run-time computations and still perform the compile...

  7. Evaluation of the roughness of the surface of porcelain systems with the atomic force microscope

    International Nuclear Information System (INIS)

    Chavarria Rodriguez, Bernal

    2013-01-01

    The surface of a dental ceramic was evaluated and compared with an atomic force microscope after being treated with different systems of polishing. 14 identical ceramic Lava® Zirconia discs were used to test the different polishing systems. 3 polishing systems from different matrix houses were used to polish dental porcelain. The samples were evaluated quantitatively with an atomic force microscope in order to study the real effectiveness of each system, on the roughness average (Ra) and the maximum peak to valley roughness (Ry) of the ceramic surfaces. A considerable reduction of the surface roughness was obtained by applying different polishing systems on the surface of dental ceramics. Very reliable values of Ra and Ry were obtained by making measurements on the structure reproduced by the atomic force microscope. The advanced ceramics of zirconium oxide presented the best physical characteristics and low levels of surface roughness. A smoother surface was achieved with the application of polishing systems, thus demonstrating the reduction of the surface roughness of a dental ceramic [es

  8. Fiber laser-microscope system for femtosecond photodisruption of biological samples.

    Science.gov (United States)

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F Ömer; Eldeniz, Y Burak; Tazebay, Uygar H

    2012-03-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.

  9. Dynamical instabilities in hot expanding nuclear systems: a microscopic approach to the understanding of multifragmentation

    International Nuclear Information System (INIS)

    Suraud, E.

    1989-01-01

    We present a microscopic study of the quasi-fusion/explosion transition in the framework of Landau-Vlasov simulations and for intermediate energy heavy-ion collisions (beam energy from 10 to 100 MeV/A). After a short presentation of the results of schematic calculations, which furnish a guideline for microscopic investigations, we discuss the relevance of our approach for studying multifragmentation. Once the limitations of this kind of dynamical simulations exhibited, we perform a detailed analysis in terms of the equation of state of the system. In agreement with schematic models we find that the composite nuclear system formed in the collision actually explodes when it stays long enough in the mechanically unstable region (spinodal region). Quantitative estimates of the explosion threshold are given for central symmetric reactions (Ca + Ca and Ar + Ti). The link of the results with transport properties and the equation of state of nuclear matter are briefly discussed

  10. Optical microscope for nuclear emulsion readout-system design and results in application

    CERN Document Server

    Winkler, K; Gussek, P; Balogh, I; Breitfelder, S; Schlichting, J; Dupraz, J P; Fabre, Jean-Paul; Panman, J; Papadopoulos, I M; Zucchelli, P; Van de Vyver, B L

    1999-01-01

    Experiments such as CHORUS at CERN require the inspection of a large amount of nuclear emulsion plates exposed to particle beams. Rare events need to be found, measured and analyzed. Their features are stored as grains in microscopic dimensions in a 3D stack of plates. A new, fully automatic immersion microscope system was developed. It features high resolution, small depth of focus, large working distance, large field of view and synchronization of illumination and detector. An additional requirement is given by variations in the refraction index and in the relative thickness of immersion oil and emulsion. The approach used is an imaging system based on a various objective lens with extreme numerical aperture, large working distance and wide field, combined with a matched high-aperture Koehler illuminator. The light source is a mercury arc lamp, combined with a filter package for the g-line. It includes liquid crystal elements for synchronized shuttering and variable attenuation. The theoretical resolution i...

  11. Combined laser and atomic force microscope lithography on aluminum: Mask fabrication for nanoelectromechanical systems

    DEFF Research Database (Denmark)

    Berini, Abadal Gabriel; Boisen, Anja; Davis, Zachary James

    1999-01-01

    A direct-write laser system and an atomic force microscope (AFM) are combined to modify thin layers of aluminum on an oxidized silicon substrate, in order to fabricate conducting and robust etch masks with submicron features. These masks are very well suited for the production of nanoelectromecha......A direct-write laser system and an atomic force microscope (AFM) are combined to modify thin layers of aluminum on an oxidized silicon substrate, in order to fabricate conducting and robust etch masks with submicron features. These masks are very well suited for the production...... writing, and to perform submicron modifications by AFM oxidation. The mask fabrication for a nanoscale suspended resonator bridge is used to illustrate the advantages of this combined technique for NEMS. (C) 1999 American Institute of Physics. [S0003-6951(99)00221-1]....

  12. Ghost microscope imaging system from the perspective of coherent-mode representation

    Science.gov (United States)

    Shen, Qian; Bai, Yanfeng; Shi, Xiaohui; Nan, Suqin; Qu, Lijie; Li, Hengxing; Fu, Xiquan

    2018-03-01

    The coherent-mode representation theory of partially coherent fields is firstly used to analyze a two-arm ghost microscope imaging system. It is shown that imaging quality of the generated images depend crucially on the distribution of the decomposition coefficients of the object imaged when the light source is fixed. This theory is also suitable for demonstrating the effects from the distance the object is moved away from the original plane on imaging quality. Our results are verified theoretically and experimentally.

  13. A compact light-sheet microscope for the study of the mammalian central nervous system

    Science.gov (United States)

    Yang, Zhengyi; Haslehurst, Peter; Scott, Suzanne; Emptage, Nigel; Dholakia, Kishan

    2016-01-01

    Investigation of the transient processes integral to neuronal function demands rapid and high-resolution imaging techniques over a large field of view, which cannot be achieved with conventional scanning microscopes. Here we describe a compact light sheet fluorescence microscope, featuring a 45° inverted geometry and an integrated photolysis laser, that is optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We demonstrate the utility of this design for three-dimensional morphological reconstruction, activation of a single synapse with localized photolysis, and fast imaging of neuronal Ca2+ signalling across a large field of view. The developed system opens up a host of novel applications for the neuroscience community. PMID:27215692

  14. Giant vesicles (GV) in colloidal system under the optical polarization microscope (OPM).

    Science.gov (United States)

    Khalid, Khalisanni; Noh, Muhammad Azri Mohd; Khan, M Niyaz; Ishak, Ruzaina; Penney, Esther; Chowdhury, Zaira Zaman; Hamzah, Mohammad Hafiz; Othman, Maizatulnisa

    2017-09-01

    This paper discusses the unprecedented microscopic findings of micellar growth in colloidal system (CS) of catalyzed piperidinolysis of ionized phenyl salicylate (PS - ). The giant vesicles (GV) was observed under the optical polarization microscope (OPM) at [NaX]=0.1M where X=3-isopropC 6 H 4 O - . The conditions were rationalized from pseudo-first-order rate constant, k obs of PS - of micellar phase at 31.1×10 -3 s -1 reported in previous publication. The overall diameter of GV (57.6μm) in CS (CTABr/NaX/H 2 O)-catalyzed piperidinolysis (where X=3-isopropC 6 H 4 O) of ionized phenyl salicylate were found as giant unilamellar vesicles (GUV) and giant multilamellar vesicles (GMV). The findings were also validated by means of rheological analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Two-level convolution formula for nuclear structure function

    Science.gov (United States)

    Ma, Boqiang

    1990-05-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

  16. Two-level convolution formula for nuclear structure function

    International Nuclear Information System (INIS)

    Ma Boqiang

    1990-01-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions

  17. Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

    International Nuclear Information System (INIS)

    Nishiyama, Hidetoshi; Koizumi, Mitsuru; Ogawa, Koji; Kitamura, Shinich; Konyuba, Yuji; Watanabe, Yoshiyuki; Ohbayashi, Norihiko; Fukuda, Mitsunori; Suga, Mitsuo; Sato, Chikara

    2014-01-01

    An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control

  18. Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Hidetoshi, E-mail: hinishiy@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Koizumi, Mitsuru, E-mail: koizumi@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Ogawa, Koji, E-mail: kogawa@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Kitamura, Shinich, E-mail: kitamura@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Konyuba, Yuji, E-mail: ykonyuub@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Watanabe, Yoshiyuki, E-mail: watanabeyoshiy@pref.yamagata.jp [Yamagata Research Institute of Technology, 2-2-1, Matsuei, Yamagata 990-2473 (Japan); Ohbayashi, Norihiko, E-mail: n.ohbayashi@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Fukuda, Mitsunori, E-mail: nori@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Suga, Mitsuo, E-mail: msuga@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Sato, Chikara, E-mail: ti-sato@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-4, Umezono, Tsukuba 305-8568 (Japan)

    2014-12-15

    An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control.

  19. Nailfold capillaroscopy by digital microscope in an Indian population with systemic sclerosis.

    Science.gov (United States)

    Bhakuni, Darshan S; Vasdev, Vivek; Garg, M K; Narayanan, Krishanan; Jain, Rahul; Mullick, Gautam

    2012-02-01

    Nailfold capillaroscopy (NFC) is a simple, non-invasive method with exceptional predictive value for the analysis of microvascular abnormalities, especially in systemic sclerosis (SSc) but remains underutilized due to cost factors of the nailfold videocapillaroscope, lack of expertise and availability issues. The aim of this study was to establish the utility of an inexpensive digital microscope to study NFC changes in SSc in correlation with disease subsets and extent of skin involvement. Twenty-two diffuse cutaneous SSc (DSS), 20 limited cutaneous SSc (LSS) patients and 42 controls were evaluated with NFC using a digital microscope at 30× and 100× magnification. Digital micrographs were used to study qualitative and quantitative changes in microvasculature. The capillary density was significantly less in all cases of SSc as compared to controls (5.3 ± 1.4 vs. 8.7 ± 1.2; P Nailfold capillaroscopy changes in SSc are related to disease subset and MRSS. NFC with digital microscope is a simplified, inexpensive, outpatient procedure with results comparable to previous studies. © 2011 The Authors. International Journal of Rheumatic Diseases © 2011 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.

  20. Development and evaluation of an automated reflectance microscope system for the petrographic characterization of bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, D. S.; Davis, A.

    1980-10-01

    The development of automated coal petrographic techniques will lessen the demands on skilled personnel to do routine work. This project is concerned with the development and successful testing of an instrument which will meet these needs. The fundamental differences in reflectance of the three primary maceral groups should enable their differentiation in an automated-reflectance frequency histogram (reflectogram). Consequently, reflected light photometry was chosen as the method for automating coal petrographic analysis. Three generations of an automated system (called Rapid Scan Versions I, II and III) were developed and evaluated for petrographic analysis. Their basic design was that of a reflected-light microscope photometer with an automatic stage, interfaced with a minicomputer. The hardware elements used in the Rapid Scan Version I limited the system's flexibility and presented problems with signal digitization and measurement precision. Rapid Scan Version II was designed to incorporate a new microscope photometer and computer system. A digital stepping stage was incorporated into the Rapid Scan Version III system. The precision of reflectance determination of this system was found to be +- 0.02 percent reflectance. The limiting factor in quantitative interpretation of Rapid Scan reflectograms is the resolution of reflectance populations of the individual maceral groups. Statistical testing indicated that reflectograms were highly reproducible, and a new computer program, PETAN, was written to interpret the curves for vitrinite reflectance parameters ad petrographic.

  1. Benchtop and animal validation of a portable fluorescence microscopic imaging system for potential use in cholecystectomy

    Science.gov (United States)

    Ye, Jian; Liu, Guanghui; Liu, Peng; Zhang, Shiwu; Shao, Pengfei; Smith, Zachary J.; Liu, Chenhai; Xu, Ronald X.

    2018-02-01

    We propose a portable fluorescence microscopic imaging system (PFMS) for intraoperative display of biliary structure and prevention of iatrogenic injuries during cholecystectomy. The system consists of a light source module, a camera module, and a Raspberry Pi computer with an LCD. Indocyanine green (ICG) is used as a fluorescent contrast agent for experimental validation of the system. Fluorescence intensities of the ICG aqueous solution at different concentration levels are acquired by our PFMS and compared with those of a commercial Xenogen IVIS system. We study the fluorescence detection depth by superposing different thicknesses of chicken breast on an ICG-loaded agar phantom. We verify the technical feasibility for identifying potential iatrogenic injury in cholecystectomy using a rat model in vivo. The proposed PFMS system is portable, inexpensive, and suitable for deployment in resource-limited settings.

  2. Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

    Science.gov (United States)

    Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

    2016-04-01

    Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

  3. A distributed multi-GPU system for high speed electron microscopic tomographic reconstruction

    International Nuclear Information System (INIS)

    Zheng, Shawn Q.; Branlund, Eric; Kesthelyi, Bettina; Braunfeld, Michael B.; Cheng, Yifan; Sedat, John W.; Agard, David A.

    2011-01-01

    Full resolution electron microscopic tomographic (EMT) reconstruction of large-scale tilt series requires significant computing power. The desire to perform multiple cycles of iterative reconstruction and realignment dramatically increases the pressing need to improve reconstruction performance. This has motivated us to develop a distributed multi-GPU (graphics processing unit) system to provide the required computing power for rapid constrained, iterative reconstructions of very large three-dimensional (3D) volumes. The participating GPUs reconstruct segments of the volume in parallel, and subsequently, the segments are assembled to form the complete 3D volume. Owing to its power and versatility, the CUDA (NVIDIA, USA) platform was selected for GPU implementation of the EMT reconstruction. For a system containing 10 GPUs provided by 5 GTX295 cards, 10 cycles of SIRT reconstruction for a tomogram of 4096 2 x512 voxels from an input tilt series containing 122 projection images of 4096 2 pixels (single precision float) takes a total of 1845 s of which 1032 s are for computation with the remainder being the system overhead. The same system takes only 39 s total to reconstruct 1024 2 x256 voxels from 122 1024 2 pixel projections. While the system overhead is non-trivial, performance analysis indicates that adding extra GPUs to the system would lead to steadily enhanced overall performance. Therefore, this system can be easily expanded to generate superior computing power for very large tomographic reconstructions and especially to empower iterative cycles of reconstruction and realignment. -- Highlights: → A distributed multi-GPU system has been developed for electron microscopic tomography (EMT). → This system allows for rapid constrained, iterative reconstruction of very large volumes. → This system can be easily expanded to generate superior computing power for large-scale iterative EMT realignment.

  4. A distributed multi-GPU system for high speed electron microscopic tomographic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Shawn Q.; Branlund, Eric; Kesthelyi, Bettina; Braunfeld, Michael B.; Cheng, Yifan; Sedat, John W. [The Howard Hughes Medical Institute and the W.M. Keck Advanced Microscopy Laboratory, Department of Biochemistry and Biophysics, University of California, San Francisco, 600, 16th Street, Room S412D, CA 94158-2517 (United States); Agard, David A., E-mail: agard@msg.ucsf.edu [The Howard Hughes Medical Institute and the W.M. Keck Advanced Microscopy Laboratory, Department of Biochemistry and Biophysics, University of California, San Francisco, 600, 16th Street, Room S412D, CA 94158-2517 (United States)

    2011-07-15

    Full resolution electron microscopic tomographic (EMT) reconstruction of large-scale tilt series requires significant computing power. The desire to perform multiple cycles of iterative reconstruction and realignment dramatically increases the pressing need to improve reconstruction performance. This has motivated us to develop a distributed multi-GPU (graphics processing unit) system to provide the required computing power for rapid constrained, iterative reconstructions of very large three-dimensional (3D) volumes. The participating GPUs reconstruct segments of the volume in parallel, and subsequently, the segments are assembled to form the complete 3D volume. Owing to its power and versatility, the CUDA (NVIDIA, USA) platform was selected for GPU implementation of the EMT reconstruction. For a system containing 10 GPUs provided by 5 GTX295 cards, 10 cycles of SIRT reconstruction for a tomogram of 4096{sup 2}x512 voxels from an input tilt series containing 122 projection images of 4096{sup 2} pixels (single precision float) takes a total of 1845 s of which 1032 s are for computation with the remainder being the system overhead. The same system takes only 39 s total to reconstruct 1024{sup 2}x256 voxels from 122 1024{sup 2} pixel projections. While the system overhead is non-trivial, performance analysis indicates that adding extra GPUs to the system would lead to steadily enhanced overall performance. Therefore, this system can be easily expanded to generate superior computing power for very large tomographic reconstructions and especially to empower iterative cycles of reconstruction and realignment. -- Highlights: {yields} A distributed multi-GPU system has been developed for electron microscopic tomography (EMT). {yields} This system allows for rapid constrained, iterative reconstruction of very large volumes. {yields} This system can be easily expanded to generate superior computing power for large-scale iterative EMT realignment.

  5. High-Definition 3D Stereoscopic Microscope Display System for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Yoo Kwan-Hee

    2010-01-01

    Full Text Available Biomedical research has been performed by using advanced information techniques, and micro-high-quality stereo images have been used by researchers and/or doctors for various aims in biomedical research and surgery. To visualize the stereo images, many related devices have been developed. However, the devices are difficult to learn for junior doctors and demanding to supervise for experienced surgeons. In this paper, we describe the development of a high-definition (HD three-dimensional (3D stereoscopic imaging display system for operating a microscope or experimenting on animals. The system consists of a stereoscopic camera part, image processing device for stereoscopic video recording, and stereoscopic display. In order to reduce eyestrain and viewer fatigue, we use a preexisting stereo microscope structure and polarized-light stereoscopic display method that does not reduce the quality of the stereo images. The developed system can overcome the discomfort of the eye piece and eyestrain caused by use over a long period of time.

  6. Application of a new MR Microscope using an Independent Console System (MRMICS) for biological tissues in vitro

    International Nuclear Information System (INIS)

    Yoshioka, Hiroshi; Anno, Izumi; Itai, Yuji; Haishi, Tomoyuki; Adachi, Naotaka; Kose, Katsumi

    1999-01-01

    We studied microscopic MR images of the normal appendix in vitro using a new MR microscope system: MR Microscope using an Independent Console System (MRMICS). The MRMICS was placed in the clinical MR room, and the probe box was fixed on the bed of the 1.5 T clinical MR machine. T1-, T2-, and proton density-weighted images were obtained using spin echo sequences with an in-plane pixel size of 100 x 100 μm. Zonal structures of the appendix were clearly demonstrated with different contrast by different sequences. Therefore, the MRMICS is a useful add-on system for investigating microscopic MR images of biological tissues in vitro. (author)

  7. Application of a new MR Microscope using an Independent Console System (MRMICS) for biological tissues in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroshi; Anno, Izumi; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Haishi, Tomoyuki; Adachi, Naotaka; Kose, Katsumi

    1999-02-01

    We studied microscopic MR images of the normal appendix in vitro using a new MR microscope system: MR Microscope using an Independent Console System (MRMICS). The MRMICS was placed in the clinical MR room, and the probe box was fixed on the bed of the 1.5 T clinical MR machine. T1-, T2-, and proton density-weighted images were obtained using spin echo sequences with an in-plane pixel size of 100 x 100 {mu}m. Zonal structures of the appendix were clearly demonstrated with different contrast by different sequences. Therefore, the MRMICS is a useful add-on system for investigating microscopic MR images of biological tissues in vitro. (author)

  8. "Economic microscope": The agent-based model set as an instrument in an economic system research

    Science.gov (United States)

    Berg, D. B.; Zvereva, O. M.; Akenov, Serik

    2017-07-01

    To create a valid model of a social or economic system one must consider a lot of parameters, conditions and restrictions. Systems and, consequently, the corresponding models are proved to be very complicated. The problem of such system model engineering can't be solved only with mathematical methods usage. The decision could be found in computer simulation. Simulation does not reject mathematical methods, mathematical expressions could become the foundation for a computer model. In these materials the set of agent-based computer models is under discussion. All the set models simulate productive agents communications, but every model is geared towards the specific goal, and, thus, has its own algorithm and its own peculiarities. It is shown that computer simulation can discover new features of the agents' behavior that can not be obtained by analytical solvation of mathematical equations and thus plays the role of some kind of economic microscope.

  9. High-speed multi-frame dynamic transmission electron microscope image acquisition system with arbitrary timing

    Science.gov (United States)

    Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

    2016-02-23

    An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses each being of a programmable pulse duration, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has a plurality of plates. A control system having a digital sequencer controls the laser and a plurality of switching components, synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to enable programmable pulse durations and programmable inter-pulse spacings.

  10. High-speed multiframe dynamic transmission electron microscope image acquisition system with arbitrary timing

    Science.gov (United States)

    Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

    2015-10-20

    An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses of a predefined pulse duration and waveform, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has two pairs of plates arranged perpendicular to one another. A control system controls the laser and a plurality of switching components synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to be provided with an independently set duration and independently set inter-pulse spacings.

  11. Microscopic coefficients for the quantum master equation of a Fermi system

    International Nuclear Information System (INIS)

    Stefanescu, E.; Sandulescu, A.

    2002-01-01

    In a previous paper, we derived a master equation for fermions, of Lindblad's form, with coefficients depending on microscopic quantities. In this paper, we study the properties of the dissipative coefficients taking into account the explicit expressions of: (a) the matrix elements of the dissipative potential, evaluated from the condition that, essentially, this potential induces transitions among the system eigenstates without significantly modifying these states, (b) the densities of the environment states according to the Thomas-Fermi model, and (c) the occupation probabilities of these states taken as a Fermi-Dirac distribution. The matrix of these coefficients correctly describes the system dynamics: (a) for a normal, Fermi-Dirac distribution of the environment population, the decays dominate the excitation processes; (b) for an inverted (exotic) distribution of this population, specific to a clustering state, the excitation processes are dominant. (author)

  12. Hybrid methods for witnessing entanglement in a microscopic-macroscopic system

    International Nuclear Information System (INIS)

    Spagnolo, Nicolo; Vitelli, Chiara; Paternostro, Mauro; De Martini, Francesco; Sciarrino, Fabio

    2011-01-01

    We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.

  13. Hybrid methods for witnessing entanglement in a microscopic-macroscopic system

    Energy Technology Data Exchange (ETDEWEB)

    Spagnolo, Nicolo [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Vitelli, Chiara [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Paternostro, Mauro [School of Mathematics and Physics, Queen' s University, BT 7 1NN Belfast (United Kingdom); De Martini, Francesco [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Accademia Nazionale dei Lincei, via della Lungara 10, I-00165 Roma (Italy); Sciarrino, Fabio [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (INO-CNR), largo E. Fermi 6, I-50125 Firenze (Italy)

    2011-09-15

    We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.

  14. In vivo microscopic imaging of the bronchial mucosa using an endo-cytoscopy system.

    Science.gov (United States)

    Shibuya, Kiyoshi; Fujiwara, Taiki; Yasufuku, Kazuhiro; Alaa, Mohamed; Chiyo, Masako; Nakajima, Takahiro; Hoshino, Hidehisa; Hiroshima, Kenzo; Nakatani, Yukio; Yoshino, Ichiro

    2011-05-01

    We investigated the capabilities of an endo-cytoscopy system (ECS) that enables microscopic imaging of the tracheobronchial tree during bronchoscopy, including normal bronchial epithelium, dysplastic mucosa and squamous cell carcinoma. The newly developed ECS has a 3.2 mm diameter that can be passed through the 4.2 mm working channel of a mother endoscope for insertion of the ECS. It has a high magnification of 570× on a 17 in. video monitor. Twenty-two patients (7 squamous cell carcinoma, 11 squamous dysplasia and 4 after PDT therapies) were underwent white light, NBI light and AFI bronchoscopy. Both abnormal areas of interest and normal bronchial mucosa were stained with 0.5% methylene blue and examined with ECS at high magnification (570×). Histological examinations using haematoxylin and eosin staining were made of biopsied specimens. Analyzed ECS images were compared with the corresponding histological examinations. In normal bronchial mucosa, ciliated columnar epithelial cells were visible. In bronchial squamous dysplasia, superficial cells with abundant cytoplasm were arranged regularly. In squamous cell carcinoma, large, polymorphic tumor cells showed increased cellular densities with irregular stratified patterns. These ECS images corresponded well with the light-microscopic examination of conventional histology. ECS was useful for the discrimination between normal bronchial epithelial cells and dysplastic cells or malignant cells during bronchoscopy in real time. This novel technology has an excellent potential to provide in vivo diagnosis during bronchoscopic examinations. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Adapting a compact confocal microscope system to a two-photon excitation fluorescence imaging architecture.

    Science.gov (United States)

    Diaspro, A; Corosu, M; Ramoino, P; Robello, M

    1999-11-01

    Within the framework of a national National Institute of Physics of Matter (INFM) project, we have realised a two-photon excitation (TPE) fluorescence microscope based on a new generation commercial confocal scanning head. The core of the architecture is a mode-locked Ti:Sapphire laser (Tsunami 3960, Spectra Physics Inc., Mountain View, CA) pumped by a high-power (5 W, 532 nm) laser (Millennia V, Spectra Physics Inc.) and an ultracompact confocal scanning head, Nikon PCM2000 (Nikon Instruments, Florence, Italy) using a single-pinhole design. Three-dimensional point-spread function has been measured to define spatial resolution performances. The TPE microscope has been used with a wide range of excitable fluorescent molecules (DAPI, Fura-2, Indo-1, DiOC(6)(3), fluoresceine, Texas red) covering a single photon spectral range from UV to green. An example is reported on 3D imaging of the helical structure of the sperm head of the Octopus Eledone cirrhosa labelled with an UV excitable dye, i.e., DAPI. The system can be easily switched for operating both in conventional and two-photon mode. Copyright 1999 Wiley-Liss, Inc.

  16. Memory Effects in the Two-Level Model for Glasses

    Science.gov (United States)

    Aquino, Gerardo; Allahverdyan, Armen; Nieuwenhuizen, Theo M.

    2008-07-01

    We study an ensemble of two-level systems interacting with a thermal bath. This is a well-known model for glasses. The origin of memory effects in this model is a quasistationary but nonequilibrium state of a single two-level system, which is realized due to a finite-rate cooling and slow thermally activated relaxation. We show that single-particle memory effects, such as negativity of the specific heat under reheating, vanish for a sufficiently disordered ensemble. In contrast, a disordered ensemble displays a collective memory effect [similar to the Kovacs effect], where nonequilibrium features of the ensemble are monitored via a macroscopic observable. An experimental realization of the effect can be used to further assess the consistency of the model.

  17. Numerical Investigation of the Microscopic Heat Current Inside a Nanofluid System Based on Molecular Dynamics Simulation and Wavelet Analysis.

    Science.gov (United States)

    Jia, Tao; Gao, Di

    2018-04-03

    Molecular dynamics simulation is employed to investigate the microscopic heat current inside an argon-copper nanofluid. Wavelet analysis of the microscopic heat current inside the nanofluid system is conducted. The signal of the microscopic heat current is decomposed into two parts: one is the approximation part; the other is the detail part. The approximation part is associated with the low-frequency part of the signal, and the detail part is associated with the high-frequency part of the signal. Both the probability distributions of the high-frequency and the low-frequency parts of the signals demonstrate Gaussian-like characteristics. The curves fit to data of the probability distribution of the microscopic heat current are established, and the parameters including the mean value and the standard deviation in the mathematical formulas of the curves show dramatic changes for the cases before and after adding copper nanoparticles into the argon base fluid.

  18. IgG4-related disease: a systemic condition with characteristic microscopic features

    DEFF Research Database (Denmark)

    Detlefsen, Sönke

    2013-01-01

    that a significant proportion of the AIP patients had a variety of extrapancreatic fibroinflammatory lesions, and that AIP therefore was the pancreatic manifestation of a systemic disease. Among these extrapancreatic manifestations, the extrahepatic bile ducts, salivary glands, thyroid, lymph nodes......During the first decade of the 21st century, IgG4-related disease (IgG4-RD), a fibroinflammatory condition occurring at multiple sites of the body, has been newly recognized. As indicated by its name, elevation of IgG4 in the serum and tissue is a common denominator of IgG4-RD. Since...... diseases on their own, others have been included under the umbrella of "multifocal fibrosclerosis". Biopsies or resection specimens from affected organs in IgG4-RD reveal several common microscopic features irrespective of the site of the lesion. Cellular and storiform fibrosis, lymphoplasmacytic...

  19. Microscopic image processing system for measuring nonuniform film thickness profiles: Image scanning ellipsometry

    International Nuclear Information System (INIS)

    Liu, A.H.; Plawsky, J.L.; Wayner, P.C. Jr.

    1993-01-01

    The long-term objective of this research program is to determine the stability and heat transfer characteristics of evaporating thin films. The current objective is to develop and use a microscopic image-processing system (IPS) which has two parts: an image analyzing interferometer (IAI) and an image scanning ellipsometer (ISE). The primary purpose of this paper is to present the basic concept of ISE, which is a novel technique to measure the two dimensional thickness profile of a non-uniform, thin film, from several nm up to several μm, in a steady state as well as in a transient state. It is a full-field imaging technique which can study every point on the surface simultaneously with high spatial resolution and thickness sensitivity, i.e., it can measure and map the 2-D film thickness profile. The ISE was tested by measuring the thickness profile and the refractive index of a nonuniform solid film

  20. Surface profile measurement by using the integrated Linnik WLSI and confocal microscope system

    Science.gov (United States)

    Wang, Wei-Chung; Shen, Ming-Hsing; Hwang, Chi-Hung; Yu, Yun-Ting; Wang, Tzu-Fong

    2017-06-01

    The white-light scanning interferometer (WLSI) and confocal microscope (CM) are the two major optical inspection systems for measuring three-dimensional (3D) surface profile (SP) of micro specimens. Nevertheless, in practical applications, WLSI is more suitable for measuring smooth and low-slope surfaces. On the other hand, CM is more suitable for measuring uneven-reflective and low-reflective surfaces. As for aspect of surface profiles to be measured, the characteristics of WLSI and CM are also different. WLSI is generally used in semiconductor industry while CM is more popular in printed circuit board industry. In this paper, a self-assembled multi-function optical system was integrated to perform Linnik white-light scanning interferometer (Linnik WLSI) and CM. A connecting part composed of tubes, lenses and interferometer was used to conjunct finite and infinite optical systems for Linnik WLSI and CM in the self-assembled optical system. By adopting the flexibility of tubes and lenses, switching to perform two different optical measurements can be easily achieved. Furthermore, based on the shape from focus method with energy of Laplacian filter, the CM was developed to enhance the on focal information of each pixel so that the CM can provide all-in-focus image for performing the 3D SP measurement and analysis simultaneously. As for Linnik WLSI, eleven-step phase shifting algorithm was used to analyze vertical scanning signals and determine the 3D SP.

  1. A distributed multi-GPU system for high speed electron microscopic tomographic reconstruction.

    Science.gov (United States)

    Zheng, Shawn Q; Branlund, Eric; Kesthelyi, Bettina; Braunfeld, Michael B; Cheng, Yifan; Sedat, John W; Agard, David A

    2011-07-01

    Full resolution electron microscopic tomographic (EMT) reconstruction of large-scale tilt series requires significant computing power. The desire to perform multiple cycles of iterative reconstruction and realignment dramatically increases the pressing need to improve reconstruction performance. This has motivated us to develop a distributed multi-GPU (graphics processing unit) system to provide the required computing power for rapid constrained, iterative reconstructions of very large three-dimensional (3D) volumes. The participating GPUs reconstruct segments of the volume in parallel, and subsequently, the segments are assembled to form the complete 3D volume. Owing to its power and versatility, the CUDA (NVIDIA, USA) platform was selected for GPU implementation of the EMT reconstruction. For a system containing 10 GPUs provided by 5 GTX295 cards, 10 cycles of SIRT reconstruction for a tomogram of 4096(2) × 512 voxels from an input tilt series containing 122 projection images of 4096(2) pixels (single precision float) takes a total of 1845 s of which 1032 s are for computation with the remainder being the system overhead. The same system takes only 39 s total to reconstruct 1024(2) × 256 voxels from 122 1024(2) pixel projections. While the system overhead is non-trivial, performance analysis indicates that adding extra GPUs to the system would lead to steadily enhanced overall performance. Therefore, this system can be easily expanded to generate superior computing power for very large tomographic reconstructions and especially to empower iterative cycles of reconstruction and realignment. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Design of a microscopic electrical impedance tomography system using two current injections

    International Nuclear Information System (INIS)

    Liu, Qin; Oh, Tong In; Wi, Hun; Woo, Eung Je; Lee, Eun Jung; Seo, Jin Keun

    2011-01-01

    We describe a novel design of a microscopic electrical impedance tomography (micro-EIT) system for long-term noninvasive monitoring of cell or tissue cultures. The core of the micro-EIT system is a sample container including two pairs of current-injection electrodes and 360 voltage-sensing electrodes. In designing the container, we took advantage of a hexagonal structure with fixed dimensions and electrode configuration. This eliminated technical difficulties related to the unknown irregular boundary geometry of an imaging object in conventional medical EIT. Attaching a pair of large current-injection electrodes fully covering the left and right sides of the hexagonal container, we generated uniform parallel current density inside the container filled with saline. The 360 voltage-sensing electrodes were placed on the front, bottom and back sides of the hexagonal container in three sets of 8 × 15 arrays with equal gaps between them. We measured voltage differences between all neighboring pairs along the direction of the parallel current pathway. For the homogeneous container, all measured voltages must be the same since the voltage changes linearly along that direction. Any anomaly in the container perturbed the current pathways and therefore equipotential lines to produce different differential voltage data. For conductivity image reconstructions, we adopted a lately developed image reconstruction algorithm for this electrode configuration to first produce projected conductivity images on the front, bottom and back sides. Using a backprojection method, we reconstructed three-dimensional conductivity images from those projection images. To improve the image quality and also to meet the mathematical requirement on the uniqueness of a reconstructed image, we used a second pair of thin and long current-injection electrodes located at the middle of the front and back sides. This paper describes the design and construction of such a micro-EIT system with experimental

  3. Optical coherence tomography-enhanced microlaryngoscopy: preliminary report of a noncontact optical coherence tomography system integrated with a surgical microscope.

    Science.gov (United States)

    Vokes, David E; Jackson, Ryan; Guo, Shuguang; Perez, Jorge A; Su, Jianping; Ridgway, James M; Armstrong, William B; Chen, Zhongping; Wong, Brian J F

    2008-07-01

    Optical coherence tomography (OCT) is a new imaging modality that uses near-infrared light to produce cross-sectional images of tissue with a resolution approaching that of light microscopy. We have previously reported use of OCT imaging of the vocal folds (VFs) during direct laryngoscopy with a probe held in contact or near-contact with the VFs. This aim of this study was to develop and evaluate a novel OCT system integrated with a surgical microscope to allow hands-free OCT imaging of the VFs, which could be performed simultaneously with microscopic visualization. We performed a prospective evaluation of a new method of acquiring OCT images of the VFs. An OCT system was successfully integrated with a surgical microscope to permit noncontact OCT imaging of the VFs of 10 patients. With this novel device we were able to identify VF epithelium and lamina propria; however, the resolution was reduced compared to that achieved with the standard contact or near-contact OCT. Optical coherence tomography is able to produce high-resolution images of vocal fold mucosa to a maximum depth of 1.6 mm. It may be used in the diagnosis of VF lesions, particularly early squamous cell carcinoma, in which OCT can show disruption of the basement membrane. Mounting the OCT device directly onto the operating microscope allows hands-free noncontact OCT imaging and simultaneous conventional microscopic visualization of the VFs. However, the lateral resolution of the OCT microscope system is 50 microm, in contrast to the conventional handheld probe system (10 microm). Although such images at this resolution are still useful clinically, improved resolution would enhance the system's performance, potentially enabling real-time OCT-guided microsurgery of the larynx.

  4. An Intelligent Decision Support System for Leukaemia Diagnosis using Microscopic Blood Images

    Science.gov (United States)

    Chin Neoh, Siew; Srisukkham, Worawut; Zhang, Li; Todryk, Stephen; Greystoke, Brigit; Peng Lim, Chee; Alamgir Hossain, Mohammed; Aslam, Nauman

    2015-01-01

    This research proposes an intelligent decision support system for acute lymphoblastic leukaemia diagnosis from microscopic blood images. A novel clustering algorithm with stimulating discriminant measures (SDM) of both within- and between-cluster scatter variances is proposed to produce robust segmentation of nucleus and cytoplasm of lymphocytes/lymphoblasts. Specifically, the proposed between-cluster evaluation is formulated based on the trade-off of several between-cluster measures of well-known feature extraction methods. The SDM measures are used in conjuction with Genetic Algorithm for clustering nucleus, cytoplasm, and background regions. Subsequently, a total of eighty features consisting of shape, texture, and colour information of the nucleus and cytoplasm sub-images are extracted. A number of classifiers (multi-layer perceptron, Support Vector Machine (SVM) and Dempster-Shafer ensemble) are employed for lymphocyte/lymphoblast classification. Evaluated with the ALL-IDB2 database, the proposed SDM-based clustering overcomes the shortcomings of Fuzzy C-means which focuses purely on within-cluster scatter variance. It also outperforms Linear Discriminant Analysis and Fuzzy Compactness and Separation for nucleus-cytoplasm separation. The overall system achieves superior recognition rates of 96.72% and 96.67% accuracies using bootstrapping and 10-fold cross validation with Dempster-Shafer and SVM, respectively. The results also compare favourably with those reported in the literature, indicating the usefulness of the proposed SDM-based clustering method. PMID:26450665

  5. MICROSCOPE mission: drag-free and attitude control system expertise activities toward the scientific team

    Science.gov (United States)

    Delavault, Stéphanie; Prieur, Pascal; Liénart, Thomas; Robert, Alain; Guidotti, Pierre-Yves

    2018-04-01

    Microscope is a CNES-ESA-ONERA-CNRS-OCA-DLR-ZARM mission dedicated to the test of the Equivalence Principle with an improved accuracy of 10-15. The 300 kg drag-free microsatellite was launched on April 25th 2016 into a 710 km dawndusk sun-synchronous orbit for a 2-year mission. To comply with stringent requirements, the drag-free and attitude control system (DFACS) involves the scientific accelerometer as main sensor and a set of 8 cold gas proportional thrusters. Once in mission mode, within the CNES drag-free expertise center (CECT) the DFACS team provides several services to the system and to the scientific mission center: cold gas monitoring and management, `Attitude' ancillary data, DFACS expertise ancillary data. For this purpose, expertise tools have been implemented in the CECT, using the flexibility and efficiency of Matlab™ utilities. This paper presents the role of the CECT within the mission and details the expertise activities of the DFACS team illustrated with some typical in flight results.

  6. Microscopic optical path length difference and polarization measurement system for cell analysis

    Science.gov (United States)

    Satake, H.; Ikeda, K.; Kowa, H.; Hoshiba, T.; Watanabe, E.

    2018-03-01

    In recent years, noninvasive, nonstaining, and nondestructive quantitative cell measurement techniques have become increasingly important in the medical field. These cell measurement techniques enable the quantitative analysis of living cells, and are therefore applied to various cell identification processes, such as those determining the passage number limit during cell culturing in regenerative medicine. To enable cell measurement, we developed a quantitative microscopic phase imaging system based on a Mach-Zehnder interferometer that measures the optical path length difference distribution without phase unwrapping using optical phase locking. The applicability of our phase imaging system was demonstrated by successful identification of breast cancer cells amongst normal cells. However, the cell identification method using this phase imaging system exhibited a false identification rate of approximately 7%. In this study, we implemented a polarimetric imaging system by introducing a polarimetric module to one arm of the Mach-Zehnder interferometer of our conventional phase imaging system. This module was comprised of a quarter wave plate and a rotational polarizer on the illumination side of the sample, and a linear polarizer on the optical detector side. In addition, we developed correction methods for the measurement errors of the optical path length and birefringence phase differences that arose through the influence of elements other than cells, such as the Petri dish. As the Petri dish holding the fluid specimens was transparent, it did not affect the amplitude information; however, the optical path length and birefringence phase differences were affected. Therefore, we proposed correction of the optical path length and birefringence phase for the influence of elements other than cells, as a prerequisite for obtaining highly precise phase and polarimetric images.

  7. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  8. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  9. Local tunneling spectroscopy of a Nb/InAs/Nb superconducting proximity system with a scanning tunneling microscope

    International Nuclear Information System (INIS)

    Inoue, K.; Takayanagi, H.

    1991-01-01

    Local tunneling spectroscopy for a Nb/In/As/Nb superconducting proximity system was demonstrated with a low-temperature scanning tunneling microscope. It is found that the local electron density of states in the InAs region is spatially modulated by the neighboring superconductor Nb

  10. Design and Development of Nonlinear Optical Microscope System: Simple Implementation with epi-Illumination Platform

    Directory of Open Access Journals (Sweden)

    Ryu Jiheun

    2015-01-01

    Full Text Available During the research using fluorescence-tagged or auto-fluorescence molecules, meaningful information is often buried deep inside the tissue, not its surface. Therefore, especially in the field of biomedical imaging, acquiring optically sectioned images from deep inside the tissue is very important. As well know already, confocal laser scanning microscopy (the most well-known optical sectioning microscopy gives axially-resolved fluorescence information using the physical background blocking component called pinhole. However, the axial range of imaging is practically limited due to such optical phenomena as the light scattered and absorbed in the tissue. However, nonlinear optical microscopy (e.g. Multiphoton microscopy, harmonic generation microscopy, coherent anti-Stokes Raman spectroscopy realized by the development of ultrafast light sources has been used for visualizing various tissues, especially in vivo, because of their low sensitivity to the limitation caused by the scattering and the absorption of light. Although nonlinear optical microscopy gives deep tissue image, it is not easy for many researcher to build customized nonlinear system. Here, we introduce an easy and simple way designing and developing such nonlinear optical microscope with upright or inverted epi-illumination platform using commercial optical components only.

  11. Microscopic and spectroscopic evaluation of novel PLGA-chitosan Nanoplexes as an ocular delivery system.

    Science.gov (United States)

    Jain, Gaurav K; Pathan, Shadab A; Akhter, Sohail; Jayabalan, Nirmal; Talegaonkar, Sushma; Khar, Roop K; Ahmad, Farhan J

    2011-02-01

    The interaction of PLGA-chitosan Nanoplexes with ocular mucosa was investigated ex vivo and in vivo to assess their potential as ocular delivery system. Fluorescent Rhodamine Nanoplexes (Rd-Nanoplexes) were prepared by ionotropic gelation method. The size and morphology of Nanoplexes was investigated by TEM, SEM and PCS. The corneal retention, uptake and penetration of Nanoplexes were analyzed by spectrofluorimetry and confocal microscopy. Corneas from Rd-Nanoplexes-treated rabbits were evaluated for the in vivo uptake and ocular tolerance. The Nanoplexes prepared were round with a mean diameter of 115.6±17nm and the encapsulation efficiency of Rd was 59.4±2.5%. Data from ex vivo and in vivo studies showed that the amounts of Rd in the cornea were significantly higher for Nanoplexes than for a control Rd solution, these amounts being fairly constant for up to 24h. Confocal microscopy of the corneas revealed paracellular and transcellular uptake of the Nanoplexes. The uptake mechanism postulated was adsorptive-mediated endocytosis and opening of the tight junctions between epithelial cells. No alteration was microscopically observed after ocular surface exposure to Nanoplexes. Taken together, these data demonstrate that Nanoplexes are potentially useful as ocular drug carriers. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Automatic vision system for analysis of microscopic behavior of flow and transport in porous media

    Science.gov (United States)

    Rashidi, Mehdi; Dehmeshki, Jamshid; Dickenson, Eric; Daemi, M. Farhang

    1997-10-01

    This paper describes the development of a novel automated and efficient vision system to obtain velocity and concentration measurement within a porous medium. An aqueous fluid lace with a fluorescent dye to microspheres flows through a transparent, refractive-index-matched column packed with transparent crystals. For illumination purposes, a planar sheet of laser passes through the column as a CCD camera records all the laser illuminated planes. Detailed microscopic velocity and concentration fields have been computed within a 3D volume of the column. For measuring velocities, while the aqueous fluid, laced with fluorescent microspheres, flows through the transparent medium, a CCD camera records the motions of the fluorescing particles by a video cassette recorder. The recorded images are acquired automatically frame by frame and transferred to the computer for processing, by using a frame grabber an written relevant algorithms through an RS-232 interface. Since the grabbed image is poor in this stage, some preprocessings are used to enhance particles within images. Finally, these enhanced particles are monitored to calculate velocity vectors in the plane of the beam. For concentration measurements, while the aqueous fluid, laced with a fluorescent organic dye, flows through the transparent medium, a CCD camera sweeps back and forth across the column and records concentration slices on the planes illuminated by the laser beam traveling simultaneously with the camera. Subsequently, these recorded images are transferred to the computer for processing in similar fashion to the velocity measurement. In order to have a fully automatic vision system, several detailed image processing techniques are developed to match exact images that have different intensities values but the same topological characteristics. This results in normalized interstitial chemical concentrations as a function of time within the porous column.

  13. Two-level modelling of real estate taxtation

    DEFF Research Database (Denmark)

    Gall, Jaroslav; Stubkjær, Erik

    2006-01-01

    Real estate taxes recurrently attract attention, because they are a source of potentially increased revenue for local and national government. Most experts agree that it is necessary to switch from using normative values for taxation to a market-value-based taxation of real property with computer......-assisted mass valuation, witch benefit from use of value maps. In Czech Republic, efforts have been made to adopt current tax policy goals, but improvements are still needed. The paper aims at supporting the current improvement process towards a market based system. It presents models, which describe aspects...... of the present Czech property tax system. A proposal for the future system focuses on the value map component. The described change depends on political involvement. This political activity is modelled as well. The hypothesis is that the two-level modelling effort enhances the change process by providing...

  14. MICROSCOPE Mission: on-orbit assessment of the Drag-Free and Attitude Control System

    DEFF Research Database (Denmark)

    Prieur, Pascal; Lienart, Thomas; Rodrigues, Manuel

    Microscope successfully completed in November 2016 its on-orbit assessment. The paper begins with a brief description of the mission, the challenging performances the DFACS has to comply with and how they led to the hardwareand software design. Then we go through the major phases of the commissio......Microscope successfully completed in November 2016 its on-orbit assessment. The paper begins with a brief description of the mission, the challenging performances the DFACS has to comply with and how they led to the hardwareand software design. Then we go through the major phases...

  15. Microscopic Polyangiitis

    Science.gov (United States)

    ... body, specifically the feet, lower legs and, in bed-ridden patients, the buttocks. The skin findings of cutaneous ... that are in contact with the lungs’ microscopic air sacs – the condition may quickly pose a threat ...

  16. Virtual tape measure for the operating microscope: system specifications and performance evaluation.

    Science.gov (United States)

    Kim, M Y; Drake, J M; Milgram, P

    2000-01-01

    The Virtual Tape Measure for the Operating Microscope (VTMOM) was created to assist surgeons in making accurate 3D measurements of anatomical structures seen in the surgical field under the operating microscope. The VTMOM employs augmented reality techniques by combining stereoscopic video images with stereoscopic computer graphics, and functions by relying on an operator's ability to align a 3D graphic pointer, which serves as the end-point of the virtual tape measure, with designated locations on the anatomical structure being measured. The VTMOM was evaluated for its baseline and application performances as well as its application efficacy. Baseline performance was determined by measuring the mean error (bias) and standard deviation of error (imprecision) in measurements of non-anatomical objects. Application performance was determined by comparing the error in measuring the dimensions of aneurysm models with and without the VTMOM. Application efficacy was determined by comparing the error in selecting the appropriate aneurysm clip size with and without the VTMOM. Baseline performance indicated a bias of 0.3 mm and an imprecision of 0.6 mm. Application bias was 3.8 mm and imprecision was 2.8 mm for aneurysm diameter. The VTMOM did not improve aneurysm clip size selection accuracy. The VTMOM is a potentially accurate tool for use under the operating microscope. However, its performance when measuring anatomical objects is highly dependent on complex visual features of the object surfaces. Copyright 2000 Wiley-Liss, Inc.

  17. Martian Microscope

    Science.gov (United States)

    2004-01-01

    The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

  18. Microscopic dynamics of the hydrogen bonded systems studied by quasi-elastic slow neutron scattering

    International Nuclear Information System (INIS)

    Padureanu, I.; Aranghel, D.; Radulescu, A.; Ion, M.; Lechner, R. E.; Desmedt, A.; Pieper, J.

    2002-01-01

    The detailed understanding of the dynamical properties in highly viscous liquids such as glycerol, as well the supercooled and glassy state has attracted a great deal of attention. Glycerol is a hydrogen bonded forming system considered as intermediate between fragile and strong glasses with a glass transition temperature T g ∼ 185 K, melting temperature T m 290 K and a sound velocity V S ∼ 3330 m/s. Incoherent neutron scattering experiments from glasses generally show a broad feature with a maximum around 2 to 10 meV. This large contribution of such unusual low frequency excitations obeying the Bose-Einstein statistics to the density of states is referred to as 'boson peak' (BP) with a maximum near a frequency of 1 THz. A very much-debated question is the dramatic changes in the properties as well as the nature of the boson peak and the acoustic modes occurring in the neighborhood of this frequency. So far the experiments were not able to give a definite answer concerning the excitations giving rise to the boson peak. The inelastic X-ray scattering across the liquid glass transition in glycerol revealed propagating collective excitations in the whole liquid-glass transition temperature range. This conclusion challenges the present understanding of glasses and supercooled liquids particularly with their thermal properties. New experiments at lower temperatures than those investigated so far where the phonon scattering processes are less hard have been proposed. The relationship between the low frequency features, the microscopic structure, the nature of the forces and the atomic motions taking place at low frequencies is still an open question. According to the mode coupling theory (MCT) the glass transition is interpreted as a two-step process where the glass structure is softened by fast local motions (β - process) until some temperature T c >T g , where the structure breaks down leading to diffusion (α-process). It is an open question, whether MCT can

  19. Moderation analysis using a two-level regression model.

    Science.gov (United States)

    Yuan, Ke-Hai; Cheng, Ying; Maxwell, Scott

    2014-10-01

    Moderation analysis is widely used in social and behavioral research. The most commonly used model for moderation analysis is moderated multiple regression (MMR) in which the explanatory variables of the regression model include product terms, and the model is typically estimated by least squares (LS). This paper argues for a two-level regression model in which the regression coefficients of a criterion variable on predictors are further regressed on moderator variables. An algorithm for estimating the parameters of the two-level model by normal-distribution-based maximum likelihood (NML) is developed. Formulas for the standard errors (SEs) of the parameter estimates are provided and studied. Results indicate that, when heteroscedasticity exists, NML with the two-level model gives more efficient and more accurate parameter estimates than the LS analysis of the MMR model. When error variances are homoscedastic, NML with the two-level model leads to essentially the same results as LS with the MMR model. Most importantly, the two-level regression model permits estimating the percentage of variance of each regression coefficient that is due to moderator variables. When applied to data from General Social Surveys 1991, NML with the two-level model identified a significant moderation effect of race on the regression of job prestige on years of education while LS with the MMR model did not. An R package is also developed and documented to facilitate the application of the two-level model.

  20. Infrared microscope inspection apparatus

    Science.gov (United States)

    Forman, Steven E.; Caunt, James W.

    1985-02-26

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

  1. Analysis of dicentrics in human lymphocytes exposed to ionizing radiation using the automated system and optical microscope

    International Nuclear Information System (INIS)

    Martinez A, J.

    2016-01-01

    Ionizing radiation is a form of energy that produces ionizations in the molecules it traverses. When the higher energy radiation interacts with the structure of human chromosomes, chromosome aberrations, mainly of the dicentric type, are the union of two damaged chromosomes, represented by two centromeres and non centromere fragment. There are situations where a population of people may be affected by the release of any radioactive material and it is impossible to determine in a short time the absorbed dose to which each person was exposed. The dicentrics analysis from the culture of human lymphocytes is used to estimate doses of exposure to ionizing radiation, using the optical microscope. The objective of this work is to analyze dicentric chromosomal lesions, using the optical microscope in comparison with the semi-automated system, to respond promptly to radiological emergencies. For this study, two samples irradiated with "6"0Co were analyzed, one in the Instituto Nacional de Investigaciones Nucleares (ININ) reaching doses of 2.7 ± 0.1 and 0.85 ± 0.1 Gy, and the other in Walischmiller Engineering G mb H, Markdorf (Germany) reaching doses of 0.84 ± 0.3 and 2.8 ± 0.1 Gy. A lymphocyte culture was performed following the recommendations of the IAEA, using minimum essential MEM medium previously prepared with BrdU, sodium heparin, antibiotic and L-glutamine. Phytohemagglutinin, fetal calf serum was added to the sample, incubated at 37 degrees Celsius for 48 hours and three hours before the end of incubation, colcemide was placed. KCl post-culture was added and lamellae were prepared by washing with the 3:1 acid-acetic fixative solution and a Giemsa staining. 1000 cell readings were performed using the optical microscope and the automated system according to study protocols and quality standards to estimate absorbed dose by means of dicentric analysis, defined by ISO-19238. With the automated system similar results of absorbed dose were obtained with respect to

  2. Variable diameter CO2 laser ring-cutting system adapted to a zoom microscope for applications on polymer tapes.

    Science.gov (United States)

    Förster, Erik; Bohnert, Patrick; Kraus, Matthias; Kilper, Roland; Müller, Ute; Buchmann, Martin; Brunner, Robert

    2016-11-20

    This paper presents the conception and implementation of a variable diameter ring-cutting system for a CO2 laser with a working wavelength of 10.6 μm. The laser-cutting system is adapted to an observation zoom microscope for combined use and is applicable for the extraction of small circular areas from polymer films, such as forensic adhesive tapes in a single shot. As an important characteristic for our application, the variable diameter ring-cutting system provides telecentricity in the target area. Ring diameters are continuously tunable between 500 μm and 2 mm. A minimum width of less than 20 μm was found for the ring profile edge. The basic characteristics of the system, including telecentricity, were experimentally evaluated and demonstrated by cutting experiments on different polymer tapes and further exemplary samples.

  3. Two level undercut-profile substrate for filamentary YBa2Cu3O7 coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Solovyov, M.; Gömöry, Fedor

    2015-01-01

    A novel substrate design is presented for scalable industrial production of filamentary coated conductors (CCs). The new substrate, called ‘two level undercut-profile substrate (2LUPS)’, has two levels of plateaus connected by walls with an undercut profile. The undercuts are made to produce...... a shading effect during subsequent deposition of layers, thereby creating gaps in the superconducting layer deposited on the curved walls between the two levels. It is demonstrated that such 2LUPS-based CCs can be produced in a large-scale production system using standard deposition processes...

  4. Silver deposition in the central nervous system and the hematoencephalic barrier studied with the electron microscope.

    Science.gov (United States)

    VAN BREEMEN, V L; CLEMENTE, C D

    1955-03-01

    For the purpose of studying the hematoencephalic barrier as it is concerned with silver circulating in the blood stream, silver nitrate was vitally administered to rats in their drinking water over periods of 6 to 8 months. The cerebrum, cerebellum, medulla, area postrema, and choroid plexus were prepared for light and electron microscopy. Silver deposition was found in the perivascular spaces in the choroid plexus, area postrema, in the medulla surrounding the area postrema, and in minute quantities in the cerebrum, cerebellum, and most of the medulla. Two levels of the hematoencephalic barrier were apparently demonstrated in our investigations. The endothelial linings of the vessels in the cerebrum, cerebellum, and medulla constitute the first threshold of the hematoencephalic barrier (specifically here, blood-brain barrier). The cell membranes adjacent to the perivascular spaces form the second threshold, as follows:-the neuroglial cell membranes in the cerebrum, cerebellum, and medulla (blood-brain barrier); the membranes of the neuroglial cells in the area postrema (blood-brain barrier); and the membranes of the epithelial cells of the choroid plexus (blood-cerebrospinal fluid barrier). This study deals with silver deposition and does not infer that the penetration of ionic silver, if present in the blood stream, would necessarily be limited to the regions described. Bleb-like structures were observed to cover the epithelial cell surfaces in the choroid plexus. They may be cellular projections increasing the cell surface area or they may be secretory droplets.

  5. Characterizing absolute piezoelectric microelectromechanical system displacement using an atomic force microscope

    International Nuclear Information System (INIS)

    Evans, J.; Chapman, S.

    2014-01-01

    Piezoresponse Force Microscopy (PFM) is a popular tool for the study of ferroelectric and piezoelectric materials at the nanometer level. Progress in the development of piezoelectric MEMS fabrication is highlighting the need to characterize absolute displacement at the nanometer and Ångstrom scales, something Atomic Force Microscopy (AFM) might do but PFM cannot. Absolute displacement is measured by executing a polarization measurement of the ferroelectric or piezoelectric capacitor in question while monitoring the absolute vertical position of the sample surface with a stationary AFM cantilever. Two issues dominate the execution and precision of such a measurement: (1) the small amplitude of the electrical signal from the AFM at the Ångstrom level and (2) calibration of the AFM. The authors have developed a calibration routine and test technique for mitigating the two issues, making it possible to use an atomic force microscope to measure both the movement of a capacitor surface as well as the motion of a micro-machine structure actuated by that capacitor. The theory, procedures, pitfalls, and results of using an AFM for absolute piezoelectric measurement are provided

  6. Characterizing absolute piezoelectric microelectromechanical system displacement using an atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J., E-mail: radiant@ferrodevices.com; Chapman, S., E-mail: radiant@ferrodevices.com [Radiant Technologies, Inc., 2835C Pan American Fwy NE, Albuquerque, New Mexico 87107 (United States)

    2014-08-14

    Piezoresponse Force Microscopy (PFM) is a popular tool for the study of ferroelectric and piezoelectric materials at the nanometer level. Progress in the development of piezoelectric MEMS fabrication is highlighting the need to characterize absolute displacement at the nanometer and Ångstrom scales, something Atomic Force Microscopy (AFM) might do but PFM cannot. Absolute displacement is measured by executing a polarization measurement of the ferroelectric or piezoelectric capacitor in question while monitoring the absolute vertical position of the sample surface with a stationary AFM cantilever. Two issues dominate the execution and precision of such a measurement: (1) the small amplitude of the electrical signal from the AFM at the Ångstrom level and (2) calibration of the AFM. The authors have developed a calibration routine and test technique for mitigating the two issues, making it possible to use an atomic force microscope to measure both the movement of a capacitor surface as well as the motion of a micro-machine structure actuated by that capacitor. The theory, procedures, pitfalls, and results of using an AFM for absolute piezoelectric measurement are provided.

  7. Modeling of Electronic Transport in Scanning Tunneling Microscope Tip-Carbon Nanotube Systems

    Science.gov (United States)

    Yamada, Toshishige; Kwak, Dochan (Technical Monitor)

    2000-01-01

    A model is proposed for two observed current-voltage (I-V) patterns in a recent experiment with a scanning tunneling microscope tip and a carbon nanotube. We claim that there are two mechanical contact modes for a tip (metal) -nanotube (semiconductor) junction (1) with or (2) without a tiny vacuum gap (0.1 - 0.2 nm). With the tip grounded, the tunneling case in (1) would produce large dI/dV with V > 0, small dI/dV with V < 0, and I = 0 near V = 0 for an either n- or p-nanotube; the Schottky mechanism in (2) would result in I does not equal 0 only with V < 0 for an n-nanotube, and the bias polarities would be reversed for a p-nanotube. The two observed I-V patterns are thus entirely explained by a tip-nanotube contact of the two types, where the nanotube must be n-type.

  8. Microscopic description of nuclear few-body systems with the stochastic variational method

    International Nuclear Information System (INIS)

    Suzuki, Yasuyuki

    2000-01-01

    A simple gambling procedure called the stochastic variational method can be applied, together with appropriate variational trial functions, to solve a few-body system where the correlation between the constituents plays an important role in determining its structure. The usefulness of the method is tested by comparing to other accurate solutions for Coulombic systems. Examples of application shown here include few-nucleon systems interacting with realistic forces and few-cluster systems with the Pauli principle being taken into account properly. These examples confirm the power of the stochastic variational method. There still remain many problems for extending to a system consisting of more particles. (author)

  9. A development of laser-plasma-based soft x-ray microscope system

    International Nuclear Information System (INIS)

    Nam, Ki Yong; Kim, Kyong Woo; Kim, Kyu Gyeom; Kwon, Young Man; Yoon, Kwon Ha

    2003-01-01

    Soft x-ray nano-imaging microscopy system for biomedical application with a high resolution about 50 nm has been designed and described, and its integrated techniques also have been studied. The system is mainly composed of soft x-ray generation system, nano-scaled control system, x-ray optical device like a condenser or object mirror, a CCD camera coupled with multichannel plate (MCP) and vacuum system. In the system, soft x-ray is generated from the laser-based plasma by focusing Nd:YAG laser beam on tantalum (Ta) target. In an x-ray optical system, a wolter mirror has been considering condensing the x-ray beam on a biological specimen and zone plate was adapted as an object mirror. A Si 3 N 4 was used as specimen holder for keeping a biological sample alive in atmosphere conditions. A back-illuminated-CCD camera coupled with multichannel plate was determined to set up.

  10. Frameless Stereotactic Insertion of Viewsite Brain Access System with Microscope-Mounted Tracking Device for Resection of Deep Brain Lesions: Technical Report.

    Science.gov (United States)

    White, Tim; Chakraborty, Shamik; Lall, Rohan; Fanous, Andrew A; Boockvar, John; Langer, David J

    2017-02-04

    The surgical management of deep brain tumors is often challenging due to the limitations of stereotactic needle biopsies and the morbidity associated with transcortical approaches. We present a novel microscopic navigational technique utilizing the Viewsite Brain Access System (VBAS) (Vycor Medical, Boca Raton, FL, USA) for resection of a deep parietal periventricular high-grade glioma as well as another glioma and a cavernoma with no related morbidity. The approach utilized a navigational tracker mounted on a microscope, which was set to the desired trajectory and depth. It allowed gentle continuous insertion of the VBAS directly to a deep lesion under continuous microscopic visualization, increasing safety by obviating the need to look up from the microscope and thus avoiding loss of trajectory. This technique has broad value for the resection of a variety of deep brain lesions.

  11. Applications of some microscopic, diffraction and absorption techniques to the study of metal--hydrogen systems

    International Nuclear Information System (INIS)

    Pick, M.A.

    1979-01-01

    Several experimental techniques were reviewed which are used to investigate metal hydrogen systems. The first technique is metallography and optical microscopy. This is a very old technique which was found to be very powerful in the case of metal hydrogen systems. A few examples of such work are shown and the results are discussed

  12. Design of a scanning gate microscope for mesoscopic electron systems in a cryogen-free dilution refrigerator.

    Science.gov (United States)

    Pelliccione, M; Sciambi, A; Bartel, J; Keller, A J; Goldhaber-Gordon, D

    2013-03-01

    We report on our design of a scanning gate microscope housed in a cryogen-free dilution refrigerator with a base temperature of 15 mK. The recent increase in efficiency of pulse tube cryocoolers has made cryogen-free systems popular in recent years. However, this new style of cryostat presents challenges for performing scanning probe measurements, mainly as a result of the vibrations introduced by the cryocooler. We demonstrate scanning with root-mean-square vibrations of 0.8 nm at 3 K and 2.1 nm at 15 mK in a 1 kHz bandwidth with our design. Using Coulomb blockade thermometry on a GaAs/AlGaAs gate-defined quantum dot, we demonstrate an electron temperature of 45 mK.

  13. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  14. A development of laser-plasma-based soft x-ray microscope system

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ki Yong; Kim, Kyong Woo; Kim, Kyu Gyeom; Kwon, Young Man; Yoon, Kwon Ha [X-ray Microscopy Research Center, Wonkwang University, Iksan (Korea, Republic of)

    2003-07-01

    Soft x-ray nano-imaging microscopy system for biomedical application with a high resolution about 50 nm has been designed and described, and its integrated techniques also have been studied. The system is mainly composed of soft x-ray generation system, nano-scaled control system, x-ray optical device like a condenser or object mirror, a CCD camera coupled with multichannel plate (MCP) and vacuum system. In the system, soft x-ray is generated from the laser-based plasma by focusing Nd:YAG laser beam on tantalum (Ta) target. In an x-ray optical system, a wolter mirror has been considering condensing the x-ray beam on a biological specimen and zone plate was adapted as an object mirror. A Si{sub 3}N{sub 4} was used as specimen holder for keeping a biological sample alive in atmosphere conditions. A back-illuminated-CCD camera coupled with multichannel plate was determined to set up.

  15. Characteristic Study of the Al 6061 T-6 used in RTP Primary Cooling System Using Scanning Electron Microscope (SEM)

    International Nuclear Information System (INIS)

    Tonny Anak Lanyau; Yusof Abdullah; Tom, P.P.

    2011-01-01

    Reactor TRIGA PUSPATI (RTP) is the only nuclear research reactor in Malaysia. Since the first criticality on 28th June 1982, RTP has been going through the safe operation and well maintenance. Along the period of operation almost 30 years, some of the reactor system and component has been refurbished, upgraded and replaced to ensure the functionality and safety to the reactor itself as well as to protect personnel and environment. Primary cooling system is to provide the sufficient cooling to the reactor by removal of the heat generated in the reactor core through the heat transfer process in the heat exchanger. In 2009, RTP has been undergoing the primary cooling system upgrades. Primary cooling system components including aluminium pipes has been dismantled and replaced with the new system. As a part of the ageing management programme and radiation damage study, the disposed aluminum pipes were taken and used in this study. Scanning Electron Microscope (SEM) is used to study the surface topography and elemental composition in conjunction of energy dispersive x-ray spectroscopy analysis. This paper presents the study that has been conducted. (author)

  16. The computer system of automatical microscope analysis of mines' individual dosimeters

    International Nuclear Information System (INIS)

    Zorawski, A.; Hawrynski, M.; Kluszczynski, D.

    1988-01-01

    The Institute of Occupational Medicine (IOM) carriers on routine investigations on miners' individual exposure to radon and its alpha radioactive daughters in Polish mines [1]. Evaluation of miners' exposure is based on automatic analysis of track detectors by computer SYSTEM RADON. The IOM used detectors of size 2x3 cm cut from Kodak LT115 or LR115 dosimetry foil. The scheme of the system is presented in Fig.1 whereas Table 1 includes specification of its elements

  17. Two-level method with coarse space size independent convergence

    Energy Technology Data Exchange (ETDEWEB)

    Vanek, P.; Brezina, M. [Univ. of Colorado, Denver, CO (United States); Tezaur, R.; Krizkova, J. [UWB, Plzen (Czech Republic)

    1996-12-31

    The basic disadvantage of the standard two-level method is the strong dependence of its convergence rate on the size of the coarse-level problem. In order to obtain the optimal convergence result, one is limited to using a coarse space which is only a few times smaller than the size of the fine-level one. Consequently, the asymptotic cost of the resulting method is the same as in the case of using a coarse-level solver for the original problem. Today`s two-level domain decomposition methods typically offer an improvement by yielding a rate of convergence which depends on the ratio of fine and coarse level only polylogarithmically. However, these methods require the use of local subdomain solvers for which straightforward application of iterative methods is problematic, while the usual application of direct solvers is expensive. We suggest a method diminishing significantly these difficulties.

  18. Electronic structure and microscopic model of V2GeO4F2-a quantum spin system with S = 1

    International Nuclear Information System (INIS)

    Rahaman, Badiur; Saha-Dasgupta, T

    2007-01-01

    We present first-principles density functional calculations and downfolding studies of the electronic and magnetic properties of the oxide-fluoride quantum spin system V 2 GeO 4 F 2 . We discuss explicitly the nature of the exchange paths and provide quantitative estimates of magnetic exchange couplings. A microscopic modelling based on analysis of the electronic structure of this systems puts it in the interesting class of weakly coupled alternating chain S = 1 systems. Based on the microscopic model, we make inferrences about its spin excitation spectra, which needs to be tested by rigorous experimental study

  19. Scanning Electron Microscope Mapping System Developed for Detecting Surface Defects in Fatigue Specimens

    Science.gov (United States)

    Bonacuse, Peter J.; Kantzos, Peter T.

    2002-01-01

    An automated two-degree-of-freedom specimen positioning stage has been developed at the NASA Glenn Research Center to map and monitor defects in fatigue specimens. This system expedites the examination of the entire gauge section of fatigue specimens so that defects can be found using scanning electron microscopy (SEM). Translation and rotation stages are driven by microprocessor-based controllers that are, in turn, interfaced to a computer running custom-designed software. This system is currently being used to find and record the location of ceramic inclusions in powder metallurgy materials. The mapped inclusions are periodically examined during interrupted fatigue experiments. The number of cycles to initiate cracks from these inclusions and the rate of growth of initiated cracks can then be quantified. This information is necessary to quantify the effect of this type of defect on the durability of powder metallurgy materials. This system was developed with support of the Ultra Safe program.

  20. Camera, handlens, and microscope optical system for imaging and coupled optical spectroscopy

    Science.gov (United States)

    Mungas, Greg S. (Inventor); Boynton, John (Inventor); Sepulveda, Cesar A. (Inventor); Nunes de Sepulveda, legal representative, Alicia (Inventor); Gursel, Yekta (Inventor)

    2012-01-01

    An optical system comprising two lens cells, each lens cell comprising multiple lens elements, to provide imaging over a very wide image distance and within a wide range of magnification by changing the distance between the two lens cells. An embodiment also provides scannable laser spectroscopic measurements within the field-of-view of the instrument.

  1. Microscopic study of multichannel processes in a six nucleon system. 1

    International Nuclear Information System (INIS)

    Vasilevskij, V.S.; Filippov, G.F.; Chopovskij, L.L.; Velaskes, H.

    1986-01-01

    The algorithm used to calculate the matrix elements of the potential energy operator of nucleons central interaction on cluster model functions describing the interaction of 3 H+ 3 H, 3 H+ 3 He and 3 He+ 3 He systems is given a detailed treatment. The explicit form of matrix elements is presented for the states with spin S=0, 1 and isospin T=1

  2. Microscopic fungi isolated from the Domica Cave system (Slovak Karst National Park, Slovakia). A review

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena

    2009-01-01

    Roč. 38, č. 1 (2009), s. 71-82 ISSN 0392-6672 Institutional research plan: CEZ:AV0Z60660521 Keywords : Domica Cave system * microfungi * air Subject RIV: EH - Ecology, Behaviour Impact factor: 0.900, year: 2009

  3. Investigation of C3 S hydration mechanism by transmission electron microscope (TEM) with integrated Super-XTM EDS system.

    Science.gov (United States)

    Sakalli, Y; Trettin, R

    2017-07-01

    Tricalciumsilicate (C 3 S, Alite) is the major component of the Portland cement clinker. Hydration of Alite is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The mechanism of the hydration of C 3 S is very complicated and not yet fully understood. There are different models describing the hydration of C 3 S in various ways. In this work for a better understanding of hydration mechanism, the hydrated C 3 S was investigated by using the transmission electron microscope (TEM) and for the first time, the samples for the investigations were prepared by using of focused ion beam from sintered pellets of C 3 S. Also, an FEI Talos F200x with an integrated Super-X EDS system was used for the investigations. FEI Talos F200X combines outstanding high-resolution S/TEM and TEM imaging with energy dispersive X-ray spectroscopy signal detection, and 3D chemical characterization with compositional mapping. TEM is a very powerful tool for material science. A high energy beam of electrons passes through a very thin sample, and the interactions between the electrons and the atoms can be used to observe the structure of the material and other features in the structure. TEM can be used to study the growth of layers and their composition. TEM produces high-resolution, two-dimensional images and will be used for a wide range of educational, science and industry applications. Chemical analysis can also be performed. The purpose of these investigations was to get the information about the composition of the C-S-H phases and some details of the nanostructure of the C-S-H phases. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  4. NEW HUMAN SEMEN ANALYSIS SYSTEM (CASA USING MICROSCOPIC IMAGE PROCESSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    N M Chaudhari

    2016-11-01

    Full Text Available Computer assisted semen analysis (CASA helps the pathologist or fertility specialist to evaluate the human semen. Detail analysis of spermatozoa like morphology and motility is very important in the process of intrauterine insemination (IUI or In-vitro fertilization (IVF in infertile couple. The main objective for this new semen analysis is to provide a low cost solution to the pathologist and gynecologist for the routine raw semen analysis, finding the concentration of the semen with dynamic background removal and classify the spermatozoa type (grade according to the motility and structural abnormality as per the WHO criteria. In this paper a new system , computer assisted semen analysis system is proposed in which hybrid approach is used to identify the moving object, scan line algorithm is applied for confirmation of the objects having tails, so that we can count the actual number of spermatozoa. For removal of background initially the dynamic background generation algorithm is proposed to create a background for background subtraction stage. The standard data set is created with 40× and 100× magnification from the different raw semen s. For testing the efficiency of proposed algorithm, same frames are applied to the existing algorithm. Another module of the system is focused on finding the motility and Type classification of individual spermatozoa.

  5. Proper alignment of the microscope.

    Science.gov (United States)

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights

  6. Relaxation dynamics in quantum dissipative systems: The microscopic effect of intramolecular vibrational energy redistribution

    Energy Technology Data Exchange (ETDEWEB)

    Uranga-Piña, L. [Facultad de Física, Universidad de la Habana, San Lázaro y L, Vedado, 10400 Havana (Cuba); Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin (Germany); Tremblay, J. C., E-mail: jean.c.tremblay@gmail.com [Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin (Germany)

    2014-08-21

    We investigate the effect of inter-mode coupling on the vibrational relaxation dynamics of molecules in weak dissipative environments. The simulations are performed within the reduced density matrix formalism in the Markovian regime, assuming a Lindblad form for the system-bath interaction. The prototypical two-dimensional model system representing two CO molecules approaching a Cu(100) surface is adapted from an ab initio potential, while the diatom-diatom vibrational coupling strength is systematically varied. In the weak system-bath coupling limit and at low temperatures, only first order non-adiabatic uni-modal coupling terms contribute to surface-mediated vibrational relaxation. Since dissipative dynamics is non-unitary, the choice of representation will affect the evolution of the reduced density matrix. Two alternative representations for computing the relaxation rates and the associated operators are thus compared: the fully coupled spectral basis, and a factorizable ansatz. The former is well-established and serves as a benchmark for the solution of Liouville-von Neumann equation. In the latter, a contracted grid basis of potential-optimized discrete variable representation is tailored to incorporate most of the inter-mode coupling, while the Lindblad operators are represented as tensor products of one-dimensional operators, for consistency. This procedure results in a marked reduction of the grid size and in a much more advantageous scaling of the computational cost with respect to the increase of the dimensionality of the system. The factorizable method is found to provide an accurate description of the dissipative quantum dynamics of the model system, specifically of the time evolution of the state populations and of the probability density distribution of the molecular wave packet. The influence of intra-molecular vibrational energy redistribution appears to be properly taken into account by the new model on the whole range of coupling strengths. It

  7. Proceedings of study meeting on microscopic and phenomenological research of interaction for light heavy-ion systems

    International Nuclear Information System (INIS)

    1991-06-01

    The Research Center for Nuclear Physics study meeting 'Microscopic and phenomenological research of interaction for light heavy-ion systems was held on March 7-9, 1990 as the study meeting in the second half of 1990, and 25 researchers took part in it. As the background of holding this study meeting, the fact that recently the rainbow scattering due to nuclear force was discovered experimentally in 16 O- 16 O system, and phenomenologically it was explained only by deep inter-nucleus potential. This should be evaluated as an important foothold for the research on the interaction for light heavy-ion systems and nuclear reaction mechanism. Accordingly, most of the papers presented this time were those related to the inter-nucleus potential and nuclear reaction mechanism. Also the development of theoretical analysis method was carried out and reported. Further, recently the experimental study on the structure and reaction of the neutron rich nucleus has advanced, and the theoretical research related to this topic was reported. (K.I.)

  8. Microscopic origin of marginal Fermi-liquid in strongly correlated spin systems

    International Nuclear Information System (INIS)

    Protogenov, A.P.; Ryndyk, D.A.

    1992-08-01

    We consider the consequences of separation of spin and charge degrees of freedom in 2+1D strongly correlated spin systems. Self-consistent spin and charge motions induced by doping in sites of ground and dual lattices form such a spectrum of quasiparticles which together with the dispersionless character of the collective excitation spectrum and the chemical potential pinning in the band centre yield the necessary behavior of charge and spin polarizability to support the theory of marginal liquid formulated by C.M. Varma et al. (Phys. Rev. Lett. 63, 1996 (1989)). (author). 28 refs, 4 figs

  9. Microscopic theoretical study of Raman spectra in charge and spin ordered cuprate systems

    International Nuclear Information System (INIS)

    Raj, B.K.; Panda, S.K.; Rout, G.C.

    2013-01-01

    Highlights: • The model calculation treats CDW interaction as pseudogap for cuprates. • The interplay of Raman active CDW-SDW mixed modes are investigated. • Independent CDW and SDW gap values can be determined from experimental data. -- Abstract: Raman scattering is one of the most powerful methods to investigate the electron as well as the phonon excitations in the systems. In this communication, we present a theoretical study of Raman scattering in the normal state of the high-T C systems in the under-doped region displaying the interplay of the spin-density-wave (SDW) and charge-density-wave (CDW) interactions. The SDW order arises from the repulsive Coulomb interaction of electrons, while the CDW order arises due to strong electron–phonon interaction giving rise to Fermi surface instability. We calculate phonon response function in order to examine the possibility of observing the SDW excitation mode in presence of the CDW interaction present in the same conduction band. The Raman scattering intensity is calculated from the imaginary part of the phonon Green’s function assigning an arbitrary spectral width. The spectral density function displays two mixed modes of excitation peaks at energies 2(Δ c ± Δ s ). The evolution of excitation peaks are investigated by varying CDW coupling, SDW coupling and the phonon momentum transfer energy

  10. Microscopic theoretical study of Raman spectra in charge and spin ordered cuprate systems

    Energy Technology Data Exchange (ETDEWEB)

    Raj, B. K. [Dept. of Physics, Govt. Autonomous College, Angul, Orissa (India); Panda, S. K. [KD Science College, Pochilima, Hinjilicut, 761 101 Ganjam, Orissa (India); Rout, G.C., E-mail: gcr@iopb.res.in [Condensed Matter Physics Group, PG Dept. of Applied Physics and Ballistics, FM University, Balasore 756 019 (India)

    2013-09-15

    Highlights: • The model calculation treats CDW interaction as pseudogap for cuprates. • The interplay of Raman active CDW-SDW mixed modes are investigated. • Independent CDW and SDW gap values can be determined from experimental data. -- Abstract: Raman scattering is one of the most powerful methods to investigate the electron as well as the phonon excitations in the systems. In this communication, we present a theoretical study of Raman scattering in the normal state of the high-T{sub C} systems in the under-doped region displaying the interplay of the spin-density-wave (SDW) and charge-density-wave (CDW) interactions. The SDW order arises from the repulsive Coulomb interaction of electrons, while the CDW order arises due to strong electron–phonon interaction giving rise to Fermi surface instability. We calculate phonon response function in order to examine the possibility of observing the SDW excitation mode in presence of the CDW interaction present in the same conduction band. The Raman scattering intensity is calculated from the imaginary part of the phonon Green’s function assigning an arbitrary spectral width. The spectral density function displays two mixed modes of excitation peaks at energies 2(Δ{sub c} ± Δ{sub s}). The evolution of excitation peaks are investigated by varying CDW coupling, SDW coupling and the phonon momentum transfer energy.

  11. Modal intersection types, two-level languages, and staged synthesis

    DEFF Research Database (Denmark)

    Henglein, Fritz; Rehof, Jakob

    2016-01-01

    -linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

  12. Dynamical Response of Catalytic Systems in a CS Corrected Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Dunin-Borkowski, Rafal E.; Boothroyd, Chris

    2010-01-01

    . In a catalytic reactor, the particles tend to sinter under reaction conditions resulting in the formation of larger particles and a loss of catalytic activity. Several models of sintering in different systems have been put forward [4,5]. However, most investigations have been post mortem studies, revealing only...... energies and energy barriers for sintering processes can be studied. The surface structures of catalytic materials are highly dependent on the surrounding atmosphere. The combined capabilities of ETEM and image CS correction provide unique possibilities to study this relationship. However, in order...... as function of Ar pressure in the pole piece gap. References [1] I. Chorkendorff and J.W. Niemantsverdriet, Concepts of Modern Catalysis and Kinetics, Wiley-VCH, Weinheim, 2003. [2] www.nacatsoc.org [3] A.K. Datye, J. Catal. 216 (2003) 144. [4] J.T. Richardson and J.G. Crump, J. Catal. 56 (1979) 417. [5] C. H...

  13. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Fapojuwo Abraham O

    2007-01-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  14. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Abraham O. Fapojuwo

    2007-11-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  15. Microscopic aspects of electrosensory system on the partially euryhaline lesser guitarfish

    Directory of Open Access Journals (Sweden)

    BIANCA S. RANGEL

    2017-12-01

    Full Text Available ABSTRACT The electrosensory system on elasmobranchs consists of subcutaneous electroreceptor organs known as ampullae of Lorenzini. The present study investigated the ampullae of Lorenzini morphology of the lesser guitarfish Zapteryx brevirostris, using light microscopy and scanning electron microscopy. The pore number found in the ventral skin surface is much higher than that found in the dorsal portion, characteristic of species that inhabit the euphotic zone. Under light microscopy it was possible to observe that the wall canal consists of a single layer of squamous epithelial cells. The canal features distal expansion, where the ampullae are located with up to six alveoli. The sensory epithelium of ampullae is composed by cubic cells, with oval nucleus, restricted to the interior of the alveoli. With analysis the clusters under scanning electron microscopy, it was possible to observe the structure and the random arrangement of individual ampullae, canals and nerves. The distribution of dorsal and ventral pores and ampullae in Z. brevirostris resembled those of the same family. The number of alveoli per ampullae was similar to that found in euryhaline elasmobranchs species, suggesting that the morphological organization in Z. brevirostris is linked to its possible evolutionary transitory position among batoids.

  16. Microscopic theoretical study of frequency dependent dielectric constant of heavy fermion systems

    Science.gov (United States)

    Shadangi, Keshab Chandra; Rout, G. C.

    2017-05-01

    The dielectric polarization and the dielectric constant plays a vital role in the deciding the properties of the Heavy Fermion Systems. In the present communication we consider the periodic Anderson's Model which consists of conduction electron kinetic energy, localized f-electron kinetic energy and the hybridization between the conduction and localized electrons, besides the Coulomb correlation energy. We calculate dielectric polarization which involves two particle Green's functions which are calculated by using Zubarev's Green's function technique. Using the equations of motion of the fermion electron operators. Finally, the temperature and frequency dependent dielectric constant is calculated from the dielectric polarization function. The charge susceptibility and dielectric constant are computed numerically for different physical parameters like the position (Ef) of the f-electron level with respect to fermi level, the strength of the hybridization (V) between the conduction and localized f-electrons, Coulomb correlation potential temperature and optical phonon wave vector (q). The results will be discussed in a reference to the experimental observations of the dielectric constants.

  17. Two-level schemes for the advection equation

    Science.gov (United States)

    Vabishchevich, Petr N.

    2018-06-01

    The advection equation is the basis for mathematical models of continuum mechanics. In the approximate solution of nonstationary problems it is necessary to inherit main properties of the conservatism and monotonicity of the solution. In this paper, the advection equation is written in the symmetric form, where the advection operator is the half-sum of advection operators in conservative (divergent) and non-conservative (characteristic) forms. The advection operator is skew-symmetric. Standard finite element approximations in space are used. The standard explicit two-level scheme for the advection equation is absolutely unstable. New conditionally stable regularized schemes are constructed, on the basis of the general theory of stability (well-posedness) of operator-difference schemes, the stability conditions of the explicit Lax-Wendroff scheme are established. Unconditionally stable and conservative schemes are implicit schemes of the second (Crank-Nicolson scheme) and fourth order. The conditionally stable implicit Lax-Wendroff scheme is constructed. The accuracy of the investigated explicit and implicit two-level schemes for an approximate solution of the advection equation is illustrated by the numerical results of a model two-dimensional problem.

  18. Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1987-04-01

    A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

  19. Portable spectroscopic scanning electron microscope on ISS: in situ nanostructural/chemical analysis for critical vehicle systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We will construct a novel field-portable miniature analytical electron microscope (EM+EDS) called Mochii "S" for in situ sensing in harsh/remote environments such as...

  20. Random model of two-level atoms interacting with electromagnetic field

    International Nuclear Information System (INIS)

    Kireev, A.N.; Meleshko, A.N.

    1983-12-01

    A phase transition has been studied in a random system of two-level atoms interacting with an electromagnetic field. It is shown that superradiation can arise when there is short-range order in a spin-subsystem. The existence of long-range order is irrelevant for this phase transition

  1. Variable temperature superconducting microscope

    Science.gov (United States)

    Cheng, Bo; Yeh, W. J.

    2000-03-01

    We have developed and tested a promising type of superconducting quantum interference device (SQUID) microscope, which can be used to detect vortex motion and can operate in magnetic fields over a large temperature range. The system utilizes a single-loop coupling transformer, consisting of a patterned high Tc superconducting thin film. At one end of the transformer, a 20 μm diam detecting loop is placed close to the sample. At the other end, a large loop is coupled to a NbTi coil, which is connected to a low Tc SQUID sensor. Transformers in a variety of sizes have been tested and calibrated. The results show that the system is capable of detecting the motion of a single vortex. We have used the microscope to study the behavior of moving vortices at various positions in a YBa2Cu3O7 thin film bridge.

  2. Mobile microscope complex GIB-1

    International Nuclear Information System (INIS)

    Belyakov, A.V.; Gorbachev, A.N.

    2002-01-01

    To study microstructure in operating pipelines of power units a mobile microscope system is developed and successfully used. The system includes a portable microscope, a monitor, power supply and a portable computer. The monitor is used for surveying images from a video camera mounted on the microscope. The magnification on visual examination constitutes x 100 and x 500. Diameters of pipelines examined should not be less than 130 mm. Surface preparation for microstructural studies includes routine mechanical rough grinding and polishing with subsequent etching [ru

  3. Virtual pinhole confocal microscope

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  4. Identification of biofloc microscopic composition as the natural bioremediation in zero water exchange of Pacific white shrimp, Penaeus vannamei, culture in closed hatchery system

    Science.gov (United States)

    Manan, Hidayah; Moh, Julia Hwei Zhong; Kasan, Nor Azman; Suratman, Suhaimi; Ikhwanuddin, Mhd

    2017-09-01

    Study on the microscopic composition of biofloc in closed hatchery culture system was carried out to determine the interaction between the aggregation flocs in the bioremediation process for the decomposition and degradation of organic matter loaded in the shrimp culture tanks. The study was done for 105 days of culture period in zero water exchange. All of the organic loaded in the culture tanks identified comes from the shrimp feces, uneaten fed, and the decomposed macro- and microorganisms died in the culture tanks. All of the microscopic organisms in the biofloc were identified using Advance microscopes Nikon 80i. From the present study, there were abundances and high varieties of phytoplankton, zooplankton, protozoa, nematodes and algae species identified as aggregates together in the flocs accumulation. All of these microscopic organisms identified implemented the symbiotic process together for food supply, become the algae grazer, act as natural water stabilizer in regulating the nutrients in culture tank and serve as decomposer for dead organic matter in the water environment. Heterotrophic bacteria identified from Pseudomonas and Aeromonas family consumed the organic matter loaded at the bottom of culture tank and converted items through chemical process as useful protein food to be consumed back by the shrimp. Overall it can be concluded that the biofloc organisms identified really contributed as natural bioremediation agents in zero water exchange culture system to ensure the water quality in the optimal condition until the end of culture period.

  5. In vivo imaging of cerebral hemodynamics and tissue scattering in rat brain using a surgical microscope camera system

    Science.gov (United States)

    Nishidate, Izumi; Kanie, Takuya; Mustari, Afrina; Kawauchi, Satoko; Sato, Shunichi; Sato, Manabu; Kokubo, Yasuaki

    2018-02-01

    We investigated a rapid imaging method to monitor the spatial distribution of total hemoglobin concentration (CHbT), the tissue oxygen saturation (StO2), and the scattering power b in the expression of musp=a(lambda)^-b as the scattering parameters in cerebral cortex using a digital red-green-blue camera. In the method, Monte Carlo simulation (MCS) for light transport in brain tissue is used to specify a relation among the RGB-values and the concentration of oxygenated hemoglobin (CHbO), that of deoxygenated hemoglobin (CHbR), and the scattering power b. In the present study, we performed sequential recordings of RGB images of in vivo exposed brain of rats while changing the fraction of inspired oxygen (FiO2), using a surgical microscope camera system. The time courses of CHbO, CHbR, CHbT, and StO2 indicated the well-known physiological responses in cerebral cortex. On the other hand, a fast decrease in the scattering power b was observed immediately after the respiratory arrest, which is similar to the negative deflection of the extracellular DC potential so-called anoxic depolarization. It is said that the DC shift coincident with a rise in extracellular potassium and can evoke cell deformation generated by water movement between intracellular and extracellular compartments, and hence the light scattering by tissue. Therefore, the decrease in the scattering power b after the respiratory arrest is indicative of changes in light scattering by tissue. The results in this study indicate potential of the method to evaluate the pathophysiological conditions and loss of tissue viability in brain tissue.

  6. Pixel detector readout electronics with two-level discriminator scheme

    International Nuclear Information System (INIS)

    Pengg, F.

    1998-01-01

    In preparation for a silicon pixel detector with more than 3,000 readout channels per chip for operation at the future large hadron collider (LHC) at CERN the analog front end of the readout electronics has been designed and measured on several test-arrays with 16 by 4 cells. They are implemented in the HP 0.8 microm process but compatible with the design rules of the radiation hard Honeywell 0.8 microm bulk process. Each cell contains bump bonding pad, preamplifier, discriminator and control logic for masking and testing within a layout area of only 50 microm by 140 microm. A new two-level discriminator scheme has been implemented to cope with the problems of time-walk and interpixel cross-coupling. The measured gain of the preamplifier is 900 mV for a minimum ionizing particle (MIP, about 24,000 e - for a 300 microm thick Si-detector) with a return to baseline within 750 ns for a 1 MIP input signal. The full readout chain (without detector) shows an equivalent noise charge to 60e - r.m.s. The time-walk, a function of the separation between the two threshold levels, is measured to be 22 ns at a separation of 1,500 e - , which is adequate for the 40 MHz beam-crossing frequency at the LHC. The interpixel cross-coupling, measured with a 40fF coupling capacitance, is less than 3%. A single cell consumes 35 microW at 3.5 V supply voltage

  7. Macroscopic transport equations in many-body systems from microscopic exclusion processes in disordered media: a review

    Directory of Open Access Journals (Sweden)

    Marta Galanti

    2016-08-01

    Full Text Available Describing particle transport at the macroscopic or mesoscopic level in non-ideal environments poses fundamental theoretical challenges in domains ranging from inter and intra-cellular transport in biology to diffusion in porous media. Yet, often the nature of the constraints coming from many-body interactions or reflecting a complex and confining environment are better understood and modeled at the microscopic level.In this paper we review the subtle link between microscopic exclusion processes and the mean-field equations that ensue from them in the continuum limit. We show that in an inhomogeneous medium, i.e. when jumps are controlled by site-dependent hopping rates, one can obtain three different nonlinear advection-diffusion equations in the continuum limit, suitable for describing transport in the presence of quenched disorder and external fields, depending on the particular rule embodying site inequivalence at the microscopic level. In a situation that might be termed point-like scenario, when particles are treated as point-like objects, the effect of crowding as imposed at the microscopic level manifests in the mean-field equations only if some degree of inhomogeneity is enforced into the model. Conversely, when interacting agents are assigned a finite size, under the more realistic extended crowding framework, exclusion constraints persist in the unbiased macroscopic representation.

  8. On thermodynamic and microscopic reversibility

    International Nuclear Information System (INIS)

    Crooks, Gavin E

    2011-01-01

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

  9. Simultaneous formation and detection of the reaction product of solid-state aspartame sweetener by FT-IR/DSC microscopic system.

    Science.gov (United States)

    Lin, S Y; Cheng, Y D

    2000-10-01

    The solid-state stability of aspartame hemihydrate (APM) sweetener during thermal treatment is important information for the food industry. The present study uses the novel technique of Fourier transform infrared microspectroscopy equipped with differential scanning calorimetry (FT-IR/DSC microscopic system) to accelerate and determine simultaneously the thermal-dependent impurity formation of solid-state APM. The results indicate a dramatic change in IR spectra from 50, 110 or 153 degrees C, which was respectively attributed to the onset temperature of water evaporation, dehydration and cyclization processes. It is suggested that the processes of dehydration and intramolecular cyclization occurred in the solid-state APM during the heating process. As an impurity, 3-carboxymethyl-6-benzyl-2,5-diketopiperazine (DKP) degraded from solid state APM via intramolecular cyclization and liberation of methanol. This was evidenced by this novel FT-IR/DSC microscopic system in a one-step procedure.

  10. Coupling scanning tunneling microscope and supersonic molecular beams: a unique tool for in situ investigation of the morphology of activated systems.

    Science.gov (United States)

    Smerieri, M; Reichelt, R; Savio, L; Vattuone, L; Rocca, M

    2012-09-01

    We report here on a new experimental apparatus combining a commercial low temperature scanning tunneling microscope with a supersonic molecular beam. This setup provides a unique tool for the in situ investigation of the topography of activated adsorption systems and opens thus new interesting perspectives. It has been tested towards the formation of the O/Ag(110) added rows reconstruction and of their hydroxylation, comparing data recorded upon O(2) exposure at thermal and hyperthermal energies.

  11. Frameless Stereotactic Insertion of Viewsite Brain Access System with Microscope-Mounted Tracking Device for Resection of Deep Brain Lesions: Technical Report

    OpenAIRE

    White, Tim; Chakraborty, Shamik; Lall, Rohan; Fanous, Andrew A; Boockvar, John; Langer, David J

    2017-01-01

    The surgical management of deep brain tumors is often challenging due to the limitations of stereotactic needle biopsies and the morbidity associated with transcortical approaches. We present a novel microscopic navigational technique utilizing the Viewsite Brain Access System (VBAS) (Vycor Medical, Boca Raton, FL, USA) for resection of a deep parietal periventricular high-grade glioma as well as another glioma and a cavernoma with no related morbidity. The approach utilized a navigational tr...

  12. Comparison of central corneal thickness and endothelial cell measurements by Scheimpflug camera system and two noncontact specular microscopes.

    Science.gov (United States)

    Karaca, Irmak; Yilmaz, Suzan Guven; Palamar, Melis; Ates, Halil

    2017-07-03

    To investigate the correlation of Scheimpflug camera system and two noncontact specular microscopes in terms of central corneal thickness (CCT) and corneal endothelial cell morphology measurements. One hundred eyes of 50 healthy subjects were examined by Pentacam Scheimpflug Analyzer, CEM-530 (Nidek Co, Ltd, Gamagori, Japan) and CellChek XL (Konan Medical, California, USA) via fully automated image analysis with no corrections made. Measurement differences and agreement between instruments were determined by intraclass correlation analysis. The mean age of the subjects was 36.74 ± 8.59 (range 22-57). CCTs were well correlated among all devices, with having CEM-530 the thinnest and CellChek XL the thickest measurements (intraclass correlation coefficient (ICC) = 0.83; p < 0.001 and ICC = 0.78; p < 0.001, respectively). Mean endothelial cell density (ECD) given by CEM-530 was lower than CellChek XL (2613.17 ± 228.62 and 2862.72 ± 170.42 cells/mm 2 , respectively; ICC = 0.43; p < 0.001). Mean value for coefficient of variation (CV) was 28.57 ± 3.61 in CEM-530 and 30.30 ± 3.53 in CellChek XL. Cell hexagonality (HEX) with CEM-530 was higher than with CellChek XL (68.70 ± 4.16% and 45.19 ± 6.58%, respectively). ECDs with CellChek XL and CEM-530 have good correlation, but the values obtained by CellChek XL are higher than CEM-530. Measurements for HEX and CV differ significantly and show weak correlation. Thus, we do not recommend interchangeable use of CellChek XL and CEM-530. In terms of CCTs, Pentacam, CEM-530 and CellChek XL specular microscopy instruments are reliable devices.

  13. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  14. two-level inventory optimization under probability event chain

    African Journals Online (AJOL)

    Journal of Modeling, Design and Management of Engineering Systems ... The paper introduces the concept of effective inventory level, which is used to evaluate the impact of upstream shortage on downstream inventory, models the inventory at warehouse and retailer under random lead time and demand, and makes the ...

  15. The Scanning Optical Microscope.

    Science.gov (United States)

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  16. An automatic system to study sperm motility and energetics

    OpenAIRE

    Shi, LZ; Nascimento, JM; Chandsawangbhuwana, C; Botvinick, EL; Berns, MW

    2008-01-01

    An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membr...

  17. Microscopic Theory of Transconductivity

    Directory of Open Access Journals (Sweden)

    A. P. Jauho

    1998-01-01

    Full Text Available Measurements of momentum transfer between two closely spaced mesoscopic electronic systems, which couple via Coulomb interaction but where tunneling is inhibited, have proven to be a fruitful method of extracting information about interactions in mesoscopic systems. We report a fully microscopic theory for transconductivity σ12, or, equivalently, momentum transfer rate between the system constituents. Our main formal result expresses the transconductivity in terms of two fluctuation diagrams, which are topologically related, but not equivalent to, the Azlamazov-Larkin and Maki-Thompson diagrams known for superconductivity. In the present paper the magnetic field dependence of σ12 is discussed, and we find that σ12(B is strongly enhanced over its zero field value, and it displays strong features, which can be understood in terms of a competition between density-of-states and screening effects.

  18. Optimizing ETL by a Two-level Data Staging Method

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Iftikhar, Nadeem; Nielsen, Per Sieverts

    2016-01-01

    In data warehousing, the data from source systems are populated into a central data warehouse (DW) through extraction, transformation and loading (ETL). The standard ETL approach usually uses sequential jobs to process the data with dependencies, such as dimension and fact data. It is a non......-/late-arriving data, and fast-/slowly-changing data. The introduced additional staging area decouples loading process from data extraction and transformation, which improves ETL flexibility and minimizes intervention to the data warehouse. This paper evaluates the proposed method empirically, which shows...

  19. Thermal analysis of two-level wind power converter under symmetrical grid fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    In this paper, the case of symmetrical grid fault when using the multi-MW wind turbine of partial-scale and full-scale two-level power converter are designed and investigated. Firstly, the different operation behaviors of the relevant power converters under the voltage dip will be described......) condition as well as the junction temperature. For the full-scale wind turbine system, the most thermal stressed power device in the grid-side converter will appear at the grid voltage below 0.5 pu, and for the partial-scale wind turbine system, the most thermal stressed power device in the rotor...

  20. Imaging arrangement and microscope

    Science.gov (United States)

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  1. Effect of Piper sarmentosum Extract on the Cardiovascular System of Diabetic Sprague-Dawley Rats: Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Zar Chi Thent

    2012-01-01

    Full Text Available Although Piper sarmentosum (PS is known to possess the antidiabetic properties, its efficacy towards diabetic cardiovascular tissues is still obscured. The present study aimed to observe the electron microscopic changes on the cardiac tissue and proximal aorta of experimental rats treated with PS extract. Thirty-two male Sprague-Dawley rats were divided into four groups: untreated control group (C, PS-treated control group (CTx, untreated diabetic group (D, and PS-treated diabetic group (DTx. Intramuscular injection of streptozotocin (STZ, 50 mg/kg body weight was given to induce diabetes. Following 28 days of diabetes induction, PS extract (0.125 g/kg body weight was administered orally for 28 days. Body weight, fasting blood glucose, and urine glucose levels were measured at 4-week interval. At the end of the study, cardiac tissues and the aorta were viewed under transmission electron microscope (TEM. DTx group showed increase in body weight and decrease in fasting blood glucose and urine glucose level compared to the D group. Under TEM study, DTx group showed lesser ultrastructural degenerative changes in the cardiac tissues and the proximal aorta compared to the D group. The results indicate that PS restores ultrastructural integrity in the diabetic cardiovascular tissues.

  2. Endodontic Treatment of Maxillary Premolar with Three Root Canals Using Optical Microscope and NiTi Rotatory Files System.

    Science.gov (United States)

    Relvas, João Bosco Formiga; de Carvalho, Fredsom Marcio Acris; Marques, André Augusto Franco; Sponchiado, Emílio Carlos; Garcia, Lucas da Fonseca Roberti

    2013-01-01

    The aim of the study was to report a clinical case of endodontic treatment of a maxillary first premolar with three root canals using an optical microscope and rotary instrumentation technique. The main complaint of the patient, a 16-year-old girl, was pain in tooth 14. After clinical and radiographic examination, irreversible pulpitis was diagnosed. An alteration in the middle third of the pulp chamber radiographically observed suggested the presence of three root canals. Pulp chamber access and initial catheterization using size number 10 K-files were performed. The optical microscope and radiographic examination were used to confirm the presence of three root canals. PathFiles #13, #16, and #19 were used to perform catheterization and ProTaper files S1 and S2 for cervical preparation. Apical preparation was performed using F1 file in the buccal canals and F2 in the palatal canal up to the working length. The root canals were filled with Endofill sealer by thermal compaction technique using McSpadden #50. The case has been receiving follow-up for 12 months and no painful symptomatology or periapical lesions have been found. The use of technological tools was able to assist the endodontic treatment of teeth with complex internal anatomy, such as three-canal premolars.

  3. Robotic autopositioning of the operating microscope.

    Science.gov (United States)

    Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

    2014-06-01

    Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

  4. Protecting quantum coherence of two-level atoms from vacuum fluctuations of electromagnetic field

    International Nuclear Information System (INIS)

    Liu, Xiaobao; Tian, Zehua; Wang, Jieci; Jing, Jiliang

    2016-01-01

    In the framework of open quantum systems, we study the dynamics of a static polarizable two-level atom interacting with a bath of fluctuating vacuum electromagnetic field and explore under which conditions the coherence of the open quantum system is unaffected by the environment. For both a single-qubit and two-qubit systems, we find that the quantum coherence cannot be protected from noise when the atom interacts with a non-boundary electromagnetic field. However, with the presence of a boundary, the dynamical conditions for the insusceptible of quantum coherence are fulfilled only when the atom is close to the boundary and is transversely polarizable. Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction. -- Highlights: •We study the dynamics of a two-level atom interacting with a bath of fluctuating vacuum electromagnetic field. •For both a single and two-qubit systems, the quantum coherence cannot be protected from noise without a boundary. •The insusceptible of the quantum coherence can be fulfilled only when the atom is close to the boundary and is transversely polarizable. •Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction.

  5. A transmission positron microscope and a scanning positron microscope being built at KEK, Japan

    International Nuclear Information System (INIS)

    Doyama, M.; Inoue, M.; Kogure, Y.; Kurihara, T.; Yagishita, A.; Shidara, T.; Nakahara, K.; Hayashi, Y.; Yoshiie, T.

    2001-01-01

    This paper reports the plans of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan improving used electron microscopes. The kinetic energies of positron produced by accelerators or by nuclear decays have not a unique value but show a spread over in a wide range. Positron beam will be guided near electron microscopes, a transmission electron microscope (JEM100S) and a scanning electron microscope (JSM25S). Positrons are slowed down by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic focused beam will be injected into an electron microscope. The focusing of positrons and electrons is achieved by magnetic system of the electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (orig.)

  6. Quantum averaging and resonances: two-level atom in a one-mode classical laser field

    Directory of Open Access Journals (Sweden)

    M. Amniat-Talab

    2007-06-01

    Full Text Available   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.

  7. Oscillations of Doppler-Raby of two level atom moving in resonator

    International Nuclear Information System (INIS)

    Kozlovskij, A.V.

    2001-01-01

    The interaction of the two-level atom with the quantum mode of the high-quality resonator uniformly moving by the classic trajectory, is considered. The recurrent formula for the probability of the atom transition with the photon radiation is determined through the dressed states method. It is shown, that the ratio between the Doppler shift value of the atom transition and the Raby frequency value of the atom-field system qualitatively effects the dependence of the moving atom transition probability on its position in the resonator, as well as on its value [ru

  8. Limitations of two-level emitters as nonlinearities in two-photon controlled-PHASE gates

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara P. S.; Heuck, Mikkel

    2017-01-01

    We investigate the origin of imperfections in the fidelity of a two-photon controlled-PHASE gate based on two-level-emitter nonlinearities. We focus on a passive system that operates without external modulations to enhance its performance. We demonstrate that the fidelity of the gate is limited...... by opposing requirements on the input pulse width for one-and two-photon-scattering events. For one-photon scattering, the spectral pulse width must be narrow compared with the emitter linewidth, while two-photon-scattering processes require the pulse width and emitter linewidth to be comparable. We find...

  9. Probe transparency in a two-level medium embedded by a squeezed vacuum

    International Nuclear Information System (INIS)

    Swain, S.; Zhou, P.

    1994-08-01

    Effect of the detuning on the probe absorption spectra of a two-level system with and without a classically driven field in a squeezed vacuum is investigated. For a strong squeezing, there is a threshold which determines the positions and widths of the absorption peaks, for the squeezed parameter M. In a large detuning, the spectra exhibit some resemblance to the Fano spectrum. The squeezing-induced transparency occurs at the frequency 2ω L - ω A in the minimum-uncertainty squeezed vacuum. This effect is not phase-sensitive. (author). 15 refs, 8 figs

  10. Fission-fragment and neutron data traced back to the macroscopic and microscopic properties of the fissioning systems

    Directory of Open Access Journals (Sweden)

    Schmidt K.-H.

    2010-10-01

    Full Text Available A new model description of fission-fragment yields and prompt neutron emission is developed. The yields of the different fission channels and their properties are attributed to the number of relevant states above the potential-energy landscape on the fission path at the moment of dynamical freeze-out, which is specific to the collective coordinate considered. The model combines well established ideas with novel concepts. The separability principle of macroscopic properties of the compound nucleus and microscopic properties of the fragments strongly reduces the number of model parameters and assures a high predictive power. The recently discovered energy-sorting mechanism in superfluid nuclear dynamics determines the sharing of intrinsic excitation energy at scission and the enhancement of even-odd structure in asymmetric splits.

  11. Calibration for medium resolution off-axis electron holography using a flexible dual-lens imaging system in a JEOL ARM 200F microscope.

    Science.gov (United States)

    Cantu-Valle, Jesus; Ruiz-Zepeda, Francisco; Mendoza-Santoyo, Fernando; Jose-Yacaman, Miguel; Ponce, Arturo

    2014-12-01

    In this work the calibration of a medium resolution off-axis electron holography using a dual-lens imaging system in a JEOL ARM 200F is shown. The objective dual-lens configuration allows adjusting the field of view from 35nm to 2.5μm. Subsequently, the parameters used in phase shift reconstruction were calibrated considering biprism voltage versus fringe spacing (σ) and versus fringe width (W). The reliability of the transmission electron microscope performance using these parameters was achieved using gold nanoparticles of known size and adjusting the excitation voltage of the lenses. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Analysis of C-shaped canal systems in mandibular second molars using surgical operating microscope and cone beam computed tomography: A clinical approach.

    Science.gov (United States)

    Chhabra, Sanjay; Yadav, Seema; Talwar, Sangeeta

    2014-05-01

    The study was aimed to acquire better understanding of C-shaped canal systems in mandibular second molar teeth through a clinical approach using sophisticated techniques such as surgical operating microscope and cone beam computed tomography (CBCT). A total of 42 extracted mandibular second molar teeth with fused roots and longitudinal grooves were collected randomly from native Indian population. Pulp chamber floors of all specimens were examined under surgical operating microscope and classified into four types (Min's method). Subsequently, samples were subjected to CBCT scan after insertion of K-files size #10 or 15 into each canal orifice and evaluated using the cross-sectional and 3-dimensional images in consultation with dental radiologist so as to obtain more accurate results. Minimum distance between the external root surface on the groove and initial file placed in the canal was also measured at different levels and statistically analyzed. Out of 42 teeth, maximum number of samples (15) belonged to Type-II category. A total of 100 files were inserted in 86 orifices of various types of specimens. Evaluation of the CBCT scan images of the teeth revealed that a total of 21 canals were missing completely or partially at different levels. The mean values for the minimum thickness were highest at coronal followed by middle and apical third levels in all the categories. Lowest values were obtained for teeth with Type-III category at all three levels. The present study revealed anatomical variations of C-shaped canal system in mandibular second molars. The prognosis of such complex canal anatomies can be improved by simultaneous employment of modern techniques such as surgical operating microscope and CBCT.

  13. Cryogenic immersion microscope

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  14. Microscopic description of nuclear reactions

    International Nuclear Information System (INIS)

    Gorbatov, A.M.

    1992-01-01

    The genealogical series method has been extended to the continuous spectrum of the many-body systems. New nonlinear integral equations have been formulated to perform the microscopical description of the nuclear reactions with arbitrary number of particles. The way to solve them numerically is demonstrated

  15. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  16. SUBJECT «NUMBER SYSTEMS» IN TWO-LEVELED FORMAT PREPARATION TEACHERS OF MATHEMATICS

    Directory of Open Access Journals (Sweden)

    V. I. Igoshin

    2017-01-01

    Full Text Available The aim of this article is to analyze the format of a two-leveled training – bachelor and master – future teachers of mathematics from the point of view of the content of mathematical material, which is to develop prospective teachers of mathematics at those two levels, shaping their professional competence.Methods. The study involves the theoretical methods: the analysis of pedagogical and methodical literature, normative documents; historical, comparative and logical analysis of the content of pedagogical mathematical education; forecasting, planning and designing of two-leveled methodical system of training of future teachers of mathematics.Results and scientific novelty. The level differentiation of the higher education system requires developing the appropriate curricula for undergraduate and graduate programs. The fundamental principle must be the principle of continuity – the magister must continue to deepen and broaden knowledge and skills, along with competences acquired, developed and formed on the undergraduate level. From these positions, this paper examines the course «Number Systems» – the most important in terms of methodology course for future mathematics teachers, and shows what content should be filled with this course at the undergraduate level and the graduate level. At the undergraduate level it is proposed to study classical number systems – natural, integer, rational, real and complex. Further extensions of the number systems are studied at the graduate level. The theory of numeric systems is presented as a theory of algebraic systems, arising at the intersection of algebra and mathematical logic. Here we study algebras over a field, division algebra over a field, an alternative algebra with division over the field, Jordan algebra, Lie algebra. Comprehension of bases of the theory of algebras by the master of the «mathematical education» profile will promote more conscious

  17. Two-level Robust Measurement Fusion Kalman Filter for Clustering Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; QI Wen-Juan; DENG Zi-Li

    2014-01-01

    This paper investigates the distributed fusion Kalman filtering over clustering sensor networks. The sensor network is partitioned as clusters by the nearest neighbor rule and each cluster consists of sensing nodes and cluster-head. Using the minimax robust estimation principle, based on the worst-case conservative system with the conservative upper bounds of noise variances, two-level robust measurement fusion Kalman filter is presented for the clustering sensor network systems with uncertain noise variances. It can significantly reduce the communication load and save energy when the number of sensors is very large. A Lyapunov equation approach for the robustness analysis is presented, by which the robustness of the local and fused Kalman filters is proved. The concept of the robust accuracy is presented, and the robust accuracy relations among the local and fused robust Kalman filters are proved. It is proved that the robust accuracy of the two-level weighted measurement fuser is equal to that of the global centralized robust fuser and is higher than those of each local robust filter and each local weighted measurement fuser. A simulation example shows the correctness and effectiveness of the proposed results.

  18. Design of a transmission electron positron microscope

    International Nuclear Information System (INIS)

    Doyama, Masao; Inoue, M.; Kogure, Y.; Hayashi, Y.; Yoshii, T.; Kurihara, T.; Tsuno, K.

    2003-01-01

    This paper reports the plans and design of positron-electron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is altered. The kinetic energies of positrons produced by accelerators or by nuclear decays are not a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, are accelerated and are focused on a nickel sheet. The monochromatic focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which are used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (author)

  19. The Population Inversion and the Entropy of a Moving Two-Level Atom in Interaction with a Quantized Field

    Science.gov (United States)

    Abo-Kahla, D. A. M.; Abdel-Aty, M.; Farouk, A.

    2018-05-01

    An atom with only two energy eigenvalues is described by a two-dimensional state space spanned by the two energy eigenstates is called a two-level atom. We consider the interaction between a two-level atom system with a constant velocity. An analytic solution of the systems which interacts with a quantized field is provided. Furthermore, the significant effect of the temperature on the atomic inversion, the purity and the information entropy are discussed in case of the initial state either an exited state or a maximally mixed state. Additionally, the effect of the half wavelengths number of the field-mode is investigated.

  20. The Homemade Microscope.

    Science.gov (United States)

    Baker, Roger C., Jr.

    1991-01-01

    Directions for the building of a pocket microscope that will make visible the details of insect structure and living bacteria are described. Background information on the history of microscopes and lenses is provided. The procedures for producing various types of lenses are included. (KR)

  1. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  2. Canyon of current suppression in an interacting two-level quantum dot

    DEFF Research Database (Denmark)

    Karlström, O; Pedersen, Jonas Nyvold; Samuelsson, P

    2011-01-01

    Motivated by the recent discovery of a canyon of conductance suppression in a two-level equal-spin quantum dot system [Phys. Rev. Lett. 104, 186804 (2010)], the transport through this system is studied in detail. At low bias and low temperature a strong current suppression is found around...... the electron-hole symmetry point independent of the couplings, in agreement with previous results. By means of a Schrieffer–Wolff transformation we are able to give an intuitive explanation to this suppression in the low-energy regime. In the general situation, numerical simulations are carried out using...... for the current suppression. It is also shown how broadening, interference, and a finite interaction energy cause a shift of the current minimum away from degeneracy. Finally we see how an increased population of the upper level leads to current peaks on each side of the suppression line. At sufficiently high...

  3. Entanglement for a Bimodal Cavity Field Interacting with a Two-Level Atom

    International Nuclear Information System (INIS)

    Liu Jia; Chen Ziyu; Bu Shenping; Zhang Guofeng

    2009-01-01

    Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom and a two-mode cavity field. Effects of Kerr-like medium and the number of photon inside the cavity on the entanglement are studied. Our results show that atomic initial state must be superposed, so that the two cavity field modes can be entangled. Moreover, we also conclude that the number of photon in the two cavity mode should be equal. The interaction between modes, namely, the Kerr effect, has a significant negative contribution. Note that the atom frequency and the cavity frequency have an indistinguishable effect, so a corresponding approximation has been made in this article. These results may be useful for quantum information in optics systems.

  4. Two-Level Hierarchical FEM Method for Modeling Passive Microwave Devices

    Science.gov (United States)

    Polstyanko, Sergey V.; Lee, Jin-Fa

    1998-03-01

    In recent years multigrid methods have been proven to be very efficient for solving large systems of linear equations resulting from the discretization of positive definite differential equations by either the finite difference method or theh-version of the finite element method. In this paper an iterative method of the multiple level type is proposed for solving systems of algebraic equations which arise from thep-version of the finite element analysis applied to indefinite problems. A two-levelV-cycle algorithm has been implemented and studied with a Gauss-Seidel iterative scheme used as a smoother. The convergence of the method has been investigated, and numerical results for a number of numerical examples are presented.

  5. Phonon induced optical gain in a current carrying two-level quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari-asl, Amir, E-mail: amir.eskandari.asl@gmail.com [Department of Physics, Shahid Beheshti University, G.C. Evin, Tehran 1983963113 (Iran, Islamic Republic of); School of Nano Science, Institute for Research in Fundamental Sciences (IPM), P.O. Box: 19395-5531, Tehran, Iran (Iran, Islamic Republic of)

    2017-05-15

    In this work we consider a current carrying two level quantum dot (QD) that is coupled to a single mode phonon bath. Using self-consistent Hartree-Fock approximation, we obtain the I-V curve of QD. By considering the linear response of our system to an incoming classical light, we see that depending on the parametric regime, the system could have weak or strong light absorption or may even show lasing. This lasing occurs at high enough bias voltages and is explained by a population inversion considering side bands, while the total electron population in the higher level is less than the lower one. The frequency at which we have the most significant lasing depends on the level spacing and phonon frequency and not on the electron-phonon coupling strength.

  6. Two-level modulation scheme to reduce latency for optical mobile fronthaul networks.

    Science.gov (United States)

    Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung; Chang, Gee-Kung

    2016-10-31

    A system using optical two-level orthogonal-frequency-division-multiplexing (OFDM) - amplitude-shift-keying (ASK) modulation is proposed and demonstrated to reduce the processing latency for the optical mobile fronthaul networks. At the proposed remote-radio-head (RRH), the high data rate OFDM signal does not need to be processed, but is directly launched into a high speed photodiode (HSPD) and subsequently emitted by an antenna. Only a low bandwidth PD is needed to recover the low data rate ASK control signal. Hence, it is simple and provides low-latency. Furthermore, transporting the proposed system over the already deployed optical-distribution-networks (ODNs) of passive-optical-networks (PONs) is also demonstrated with 256 ODN split-ratios.

  7. Quantum theory and microscopic mechanics. I

    International Nuclear Information System (INIS)

    Yussouff, M.

    1984-08-01

    The need for theoretical descriptions and experimental observations on 'small' individual systems is emphasized. It is shown that the mathematical basis for microscopic mechanics is very simple in one dimension. The square well problem is discussed to clarify general points about stationary states and the continuity of (p'/p) across potential boundaries in the applications of microscopic mechanics. (author)

  8. Development and evaluation of a two-level functional structure for the thin film encapsulation

    International Nuclear Information System (INIS)

    Lee, Jae-Wung; Sharma, Jaibir; Singh, Navab; Kwong, Dim-Lee

    2013-01-01

    This paper reports a two level capping structure for encapsulating micro-electro-mechanical system (MEMS) devices. The two level capping solves the main issue of the longer release time as well as safe sealing in thin film encapsulation (TFE). In this technique, the first cap layer has many etch holes, which were uniformly distributed on it to enhance the removal of the sacrificial layer. The second cap layer forms a cap on every etch hole in the first cap layer to protect the mass loading on MEMS devices. This technique was found to be very effective in reducing the release time of the TFE. For the 1200 µm × 1200 µm sized cavity encapsulation, this technique decreases the release time of the TFE by a factor of 24 in comparison to the sidewall located channel scheme. The presented technique also helps in reducing the size of TFE as the etch holes are uniformly distributed on the TFE itself. Wide seal rings were not required to accommodate sidewall channels. (paper)

  9. Ramsey interferometry with a two-level generalized Tonks-Girardeau gas

    International Nuclear Information System (INIS)

    Mousavi, S. V.; Campo, A. del; Lizuain, I.; Muga, J. G.

    2007-01-01

    We propose a solvable generalization of the Tonks-Girardeau model that describes a coherent one-dimensional (1D) gas of cold two-level bosons which interact with two external fields in a Ramsey interferometer. They also interact among themselves by idealized, infinitely strong contact potentials, with interchange of momentum and internal state. We study the corresponding Ramsey fringes and the quantum projection noise which, essentially unaffected by the interactions, remains that for ideal bosons. The dual system of this gas, an ideal gas of two-level fermions coupled by the interaction with the separated fields, produces the same fringes and noise fluctuations. The cases of time-separated and spatially separated fields are studied. For spatially separated fields the fringes may be broadened slightly by increasing the number of particles, but only for large particle numbers far from present experiments with Tonks-Girardeau gases. The uncertainty in the determination of the atomic transition frequency diminishes, essentially with the inverse root of the particle number. The difficulties to implement the model experimentally and possible shortcomings of strongly interacting 1D gases for frequency standards and atomic clocks are discussed

  10. Acquisition parameters optimization of a transmission electron forward scatter diffraction system in a cold-field emission scanning electron microscope for nanomaterials characterization.

    Science.gov (United States)

    Brodusch, Nicolas; Demers, Hendrix; Trudeau, Michel; Gauvin, Raynald

    2013-01-01

    Transmission electron forward scatter diffraction (t-EFSD) is a new technique providing crystallographic information with high resolution on thin specimens by using a conventional electron backscatter diffraction (EBSD) system in a scanning electron microscope. In this study, the impact of tilt angle, working distance, and detector distance on the Kikuchi pattern quality were investigated in a cold-field emission scanning electron microscope (CFE-SEM). We demonstrated that t-EFSD is applicable for tilt angles ranging from -20° to -40°. Working distance (WD) should be optimized for each material by choosing the WD for which the EBSD camera screen illumination is the highest, as the number of detected electrons on the screen is directly dependent on the scattering angle. To take advantage of the best performances of the CFE-SEM, the EBSD camera should be close to the sample and oriented towards the bottom to increase forward scattered electron collection efficiency. However, specimen chamber cluttering and beam/mechanical drift are important limitations in the CFE-SEM used in this work. Finally, the importance of t-EFSD in materials science characterization was illustrated through three examples of phase identification and orientation mapping. © Wiley Periodicals, Inc.

  11. The new Isidore microscope

    International Nuclear Information System (INIS)

    Rabouille, O.; Viard, J.; Menard, M.; Allegre, S.

    2001-01-01

    In the frame of the refurbishment of LECI hot laboratory in Saclay, it was decided to renew one of the two metallography lines of the building. This line is located at one end of the Isidore line of lead-shielded hot cells. The work started by the cleaning of 5 aout of 9 cells in Isidore line. Two were 2 m x 1.5 m cells, whereas the 3 others were smaller. Decontamination was difficult in both larger cells, because a lot of metallographic preparation had been performed there and because the cleaning of the lower parts of the cell, below the working area, was uneasy by remote manipulators. The refurbishment of the cells included: - Changing the windows, because old windows were made of glass panels sperated by oil, which is now prohibited by safety requirements. - Putting of a new pair of manipulators on one large cell, and adding bootings on manipulators on one large cell, and adding bootings on manipulators on both large cells. - Changing all the ventilation systems in these cells (new types of filters, new air-ducts), - Modifying and changing metallic pieces constituting the working are inside the cell - Increasing the hight of the small cells in order to add a manipulator for charging the sample on microscope or on hardness machine. - Simplifying the electrical wiring in order to decrease the fire risk in the hot cell line. - Add a better fire protection between the working area and the transfer area, i. e. between the front and the rear part of the cells. The scientific equipments fot these cells are: An Olympus microscope, modified by Optique Peter (company based in Lyons), equipped with a motorised sample holder (100 x 200 mm), maximum size of sample: O. D.=100 mm, 6 magnifications: x 12.5, x50, x100, x200, x500 and x1000, two microhardness positions: Vickers and Knoop. Polaroid image and digital camera with SIS image analysis system. A new periscope manufactured by Optique Peter. magnification x2 and x9, digital image and SIS system, and old periscope

  12. Information Entropy Squeezing of a Two-Level Atom Interacting with Two-Mode Coherent Fields

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Juan; FANG Mao-Fa

    2004-01-01

    From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing.

  13. Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Clemens [ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, Brisbane (Australia); Lisenfeld, Juergen [Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe (Germany); Shnirman, Alexander [Institut fuer Theory der Kondensierten Materie, Karlsruhe Institute of Technology, Karlsruhe (Germany); LD Landau Institute for Theoretical Physics, Moscow (Russian Federation); Poletto, Stefano [IBM TJ Watson Research Centre, Yorktown Heights (United States)

    2016-07-01

    Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

  14. Nonlinear Jaynes–Cummings model for two interacting two-level atoms

    International Nuclear Information System (INIS)

    Santos-Sánchez, O de los; González-Gutiérrez, C; Récamier, J

    2016-01-01

    In this work we examine a nonlinear version of the Jaynes–Cummings model for two identical two-level atoms allowing for Ising-like and dipole–dipole interplays between them. The model is said to be nonlinear in the sense that it can incorporate both a general intensity-dependent interaction between the atomic system and the cavity field and/or the presence of a nonlinear medium inside the cavity. As an example, we consider a particular type of atom-field coupling based upon the so-called Buck–Sukumar model and a lossless Kerr-like cavity. We describe the possible effects of such features on the evolution of some quantities of current interest, such as atomic excitation, purity, concurrence, the entropy of the field and the evolution of the latter in phase space. (paper)

  15. In-situ Crystallization of Highly Volatile Commercial Mold Flux Using an Isolated Observation System in the Confocal Laser Scanning Microscope

    Science.gov (United States)

    Park, Jun-Yong; Ryu, Jae Wook; Sohn, Il

    2014-08-01

    The in situ crystallization behavior of highly volatile commercial mold fluxes for medium carbon steels was investigated using the confocal laser scanning microscope (CLSM) equipped with an optimized isolated observation system. The highly volatile compounds of the mold flux were suppressed during heating allowing direct observation in the CLSM. Cooling rates of 25, 50, 100, 400, and 800 K/min were incorporated and continuous cooling transformation (CCT) diagrams of 4 different commercial mold fluxes for medium carbon steels were developed. Identification of the crystalline phase was conducted with XRD and SEM-EDS analysis. A cuspidine crystalline was observed in all samples at various cooling rates. With higher basicity, CaF2, and NaF, the crystallization of the fluxes was enhanced according to the CCT diagram. As the slag structure becomes depolymerized, the diffusion rate of the cathodic ions seems to increase.

  16. Calibration for medium resolution off-axis electron holography using a flexible dual-lens imaging system in a JEOL ARM 200F microscope

    International Nuclear Information System (INIS)

    Cantu-Valle, Jesus; Ruiz-Zepeda, Francisco; Mendoza-Santoyo, Fernando; Jose-Yacaman, Miguel; Ponce, Arturo

    2014-01-01

    In this work the calibration of a medium resolution off-axis electron holography using a dual-lens imaging system in a JEOL ARM 200F is shown. The objective dual-lens configuration allows adjusting the field of view from 35 nm to 2.5 μm. Subsequently, the parameters used in phase shift reconstruction were calibrated considering biprism voltage versus fringe spacing (σ) and versus fringe width (W). The reliability of the transmission electron microscope performance using these parameters was achieved using gold nanoparticles of known size and adjusting the excitation voltage of the lenses. - Highlights: • We presented the off-axis electron holography calibration in dual-lens mode of a JEOL ARM 200F. • We provide optimal conditions for a wide field of views varying the objective lens excitation. • The calibration was made using Au-nanoparticles controlling fringe width, spacing and contrast. • Application of electron holography to nanoparticles is also shown

  17. Chromosome structure investigated with the atomic force microscope

    NARCIS (Netherlands)

    de Grooth, B.G.; Putman, C.A.J.; Putman, Constant A.; van der Werf, Kees; van Hulst, N.F.; van Oort, G.; van Oort, Geeske; Greve, Jan; Manne, Srinivas

    1992-01-01

    We have developed an atomic force microscope (AFM) with an integrated optical microscope. The optical microscope consists of an inverted epi-illumination system that yields images in reflection or fluorescence of the sample. With this system it is possible to quickly locate an object of interest. A

  18. Development and applications of the positron microscope

    International Nuclear Information System (INIS)

    1991-01-01

    Progress on the positron microscope during the past year has been steady, and we currently project that initial microscope images can be collected during mid to late summer of 1992. Work during the year has mainly been divided among four areas of effort: hardware construction; power supply and control system development; radioactive source fabrication; and planning of initial experimental projects. Details of progress in these areas will be given below. An initial optical design of the microscope was completed during 1990, but during the past year, significant improvements have been made to this design, and several limiting cases of microscope performance have been evaluated. The results of these evaluations have been extremely encouraging, giving us strong indications that the optical performance of the microscope will be better than originally anticipated. In particular, we should be able to explore ultimate performance capabilities of positron microscopy using our currently planned optical system, with improvements only in the image detector system, and the positron-source/moderator configuration. We should be able to study imaging reemission microscopy with resolutions approaching 10 Angstrom and be able to produce beam spots for rastered microscope work with diameters below the 1000 Angstrom diffusion limit. Because of these exciting new possibilities, we have decided to upgrade several microscope subsystems to levels consistent with ultimate performance earlier in our construction schedule than we had previously intended. In particular, alignment facilities in the optical system, vibration isolation, and power supply and control system flexibility have all been upgraded in their design over the past year

  19. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  20. Microscopic approach to polaritons

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1981-01-01

    contrary to experimental experience. In order to remove this absurdity the semiclassical approach must be abandoned and the electromagnetic field quantized. A simple microscopic polariton model is then derived. From this the wave function for the interacting exciton-photon complex is obtained...... of light of the crystal. The introduction of damping smears out the excitonic spectra. The wave function of the polariton, however, turns out to be very independent of damping up to large damping values. Finally, this simplified microscopic polariton model is compared with the exact solutions obtained...... for the macroscopic polariton model by Hopfield. It is seen that standing photon and exciton waves must be included in an exact microscopic polariton model. However, it is concluded that for practical purposes, only the propagating waves are of importance and the simple microscopic polariton wave function derived...

  1. Microscopic Characterization of Scalable Coherent Rydberg Superatoms

    Directory of Open Access Journals (Sweden)

    Johannes Zeiher

    2015-08-01

    Full Text Available Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single-particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions, which lead to extreme nonlinearities in laser-coupled atomic ensembles. As a result, multiple excitation of a micrometer-sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called a “superatom,” is a valuable resource for quantum information, providing a collective qubit. Here, we report on the preparation of 2 orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub-shot-noise precision by local manipulation of a two-dimensional Mott insulator. We microscopically confirm the superatom picture by in situ detection of the Rydberg excitations and observe the characteristic square-root scaling of the optical coupling with the number of atoms. Enabled by the full control over the atomic sample, including the motional degrees of freedom, we infer the overlap of the produced many-body state with a W state from the observed Rabi oscillations and deduce the presence of entanglement. Finally, we investigate the breakdown of the superatom picture when two Rydberg excitations are present in the system, which leads to dephasing and a loss of coherence.

  2. Bayesian feedback versus Markovian feedback in a two-level atom

    International Nuclear Information System (INIS)

    Wiseman, H.M.; Mancini, Stefano; Wang Jin

    2002-01-01

    We compare two different approaches to the control of the dynamics of a continuously monitored open quantum system. The first is Markovian feedback, as introduced in quantum optics by Wiseman and Milburn [Phys. Rev. Lett. 70, 548 (1993)]. The second is feedback based on an estimate of the system state, developed recently by Doherty and Jacobs [Phys. Rev. A 60, 2700 (1999)]. Here we choose to call it, for brevity, Bayesian feedback. For systems with nonlinear dynamics, we expect these two methods of feedback control to give markedly different results. The simplest possible nonlinear system is a driven and damped two-level atom, so we choose this as our model system. The monitoring is taken to be homodyne detection of the atomic fluorescence, and the control is by modulating the driving. The aim of the feedback in both cases is to stabilize the internal state of the atom as close as possible to an arbitrarily chosen pure state, in the presence of inefficient detection and other forms of decoherence. Our results (obtained without recourse to stochastic simulations) prove that Bayesian feedback is never inferior, and is usually superior, to Markovian feedback. However, it would be far more difficult to implement than Markovian feedback and it loses its superiority when obvious simplifying approximations are made. It is thus not clear which form of feedback would be better in the face of inevitable experimental imperfections

  3. Microscopic Theory of Fission

    International Nuclear Information System (INIS)

    Younes, W; Gogny, D

    2008-01-01

    In recent years, the microscopic method has been applied to the notoriously difficult problem of nuclear fission with unprecedented success. In this paper, we discuss some of the achievements and promise of the microscopic method, as embodied in the Hartree-Fock method using the Gogny finite-range effective interaction, and beyond-mean-field extensions to the theory. The nascent program to describe induced fission observables using this approach at the Lawrence Livermore National Laboratory is presented

  4. Occupational concerns associated with regular use of microscope

    OpenAIRE

    Garima Jain; Pushparaja Shetty

    2014-01-01

    Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire...

  5. Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

    Science.gov (United States)

    Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

    2015-09-01

    Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

  6. From microscopic to macroscopic sports injuries. Applying the complex dynamic systems approach to sports medicine: a narrative review.

    Science.gov (United States)

    Pol, Rafel; Hristovski, Robert; Medina, Daniel; Balague, Natalia

    2018-04-19

    A better understanding of how sports injuries occur in order to improve their prevention is needed for medical, economic, scientific and sports success reasons. This narrative review aims to explain the mechanisms that underlie the occurrence of sports injuries, and an innovative approach for their prevention on the basis of complex dynamic systems approach. First, we explain the multilevel organisation of living systems and how function of the musculoskeletal system may be impaired. Second, we use both, a constraints approach and a connectivity hypothesis to explain why and how the susceptibility to sports injuries may suddenly increase. Constraints acting at multiple levels and timescales replace the static and linear concept of risk factors, and the connectivity hypothesis brings an understanding of how the accumulation of microinjuries creates a macroscopic non-linear effect, that is, how a common motor action may trigger a severe injury. Finally, a recap of practical examples and challenges for the future illustrates how the complex dynamic systems standpoint, changing the way of thinking about sports injuries, offers innovative ideas for improving sports injury prevention. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  7. Light microscopic autoradiographic localization of mu and delta opioid binding sites in the mouse central nervous system

    International Nuclear Information System (INIS)

    Moskowitz, A.S.; Goodman, R.R.

    1984-01-01

    Much work has been done on opioid systems in the rat CNS. Although the mouse is widely used in pharmacological studies of opioid action, little has been done to characterize opioid systems in this species. In the present study the distribution of mu and delta opioid binding sites in the mouse CNS was examined using a quantitative in vitro autoradiography procedure. Tritiated dihydromorphine was used to visualize mu sites and [3H-d-Ala2-d-Leu5]enkephalin with a low concentration of morphine was used to visualize delta sites. Mu and delta site localizations in the mouse are very similar to those previously described in the rat (Goodman, R.R., S.H. Snyder, M.J. Kuhar, and W.S. Young, 3d (1980) Proc. Natl. Acad. Sci. U.S.A. 77:6239-6243), with certain exceptions and additions. Mu and delta sites were observed in sensory processing areas, limbic system, extrapyramidal motor system, and cranial parasympathetic system. Differential distributions of mu and delta sites were noted in many areas. Mu sites were prominent in laminae I, IV, and VI of the neocortex, in patches in the striatum, and in the ventral pallidum, nucleus accumbens, medial and midline thalamic nuclei, medial habenular nucleus, interpeduncular nucleus, and laminae I and II of the spinal cord. In contrast, delta sites were prominent in all laminae of the neocortex, olfactory tubercle, diffusely throughout the striatum, and in the basal, lateral, and cortical nuclei of the amygdala. The determination of the differential distributions of opioid binding sites should prove useful in suggesting anatomical substrates for the actions of opiates and opioids

  8. Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation

    Science.gov (United States)

    Melgar, Miguel A; Tobler, William D; Ernst, Robert J; Raley, Thomas J; Anand, Neel; Miller, Larry E; Nasca, Richard J

    2014-01-01

    Background Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. Methods We performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months). Results There was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p lordosis, defined as a change in Cobb angle ≤ 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change. Conclusions/Clinical Relevance Two-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change. PMID:25694920

  9. Preparing and probing many-body correlated systems in a Quantum Gas Microscope by engineering arbitrary landscape potentials

    Science.gov (United States)

    Rispoli, Matthew; Lukin, Alexander; Ma, Ruichao; Preiss, Philipp; Tai, M. Eric; Islam, Rajibul; Greiner, Markus

    2015-05-01

    Ultracold atoms in optical lattices provide a versatile tool box for observing the emergence of strongly correlated physics in quantum systems. Dynamic control of optical potentials on the single-site level allows us to prepare and probe many-body quantum states through local Hamiltonian engineering. We achieve these high precision levels of optical control through spatial light modulation with a DMD (digital micro-mirror device). This allows for both arbitrary beam shaping and aberration compensation in our imaging system to produce high fidelity optical potentials. We use these techniques to control state initialization, Hamiltonian dynamics, and measurement in experiments investigating low-dimensional many-body physics - from one-dimensional correlated quantum walks to characterizing entanglement.

  10. Two-step values for games with two-level communication structure

    NARCIS (Netherlands)

    Béal, Silvain; Khmelnitskaya, Anna Borisovna; Solal, Philippe

    TU games with two-level communication structure, in which a two-level communication structure relates fundamentally to the given coalition structure and consists of a communication graph on the collection of the a priori unions in the coalition structure, as well as a collection of communication

  11. Domain decomposition method of stochastic PDEs: a two-level scalable preconditioner

    International Nuclear Information System (INIS)

    Subber, Waad; Sarkar, Abhijit

    2012-01-01

    For uncertainty quantification in many practical engineering problems, the stochastic finite element method (SFEM) may be computationally challenging. In SFEM, the size of the algebraic linear system grows rapidly with the spatial mesh resolution and the order of the stochastic dimension. In this paper, we describe a non-overlapping domain decomposition method, namely the iterative substructuring method to tackle the large-scale linear system arising in the SFEM. The SFEM is based on domain decomposition in the geometric space and a polynomial chaos expansion in the probabilistic space. In particular, a two-level scalable preconditioner is proposed for the iterative solver of the interface problem for the stochastic systems. The preconditioner is equipped with a coarse problem which globally connects the subdomains both in the geometric and probabilistic spaces via their corner nodes. This coarse problem propagates the information quickly across the subdomains leading to a scalable preconditioner. For numerical illustrations, a two-dimensional stochastic elliptic partial differential equation (SPDE) with spatially varying non-Gaussian random coefficients is considered. The numerical scalability of the the preconditioner is investigated with respect to the mesh size, subdomain size, fixed problem size per subdomain and order of polynomial chaos expansion. The numerical experiments are performed on a Linux cluster using MPI and PETSc parallel libraries.

  12. Microscopic description of pair transfer between two superfluid Fermi systems: Combining phase-space averaging and combinatorial techniques

    Science.gov (United States)

    Regnier, David; Lacroix, Denis; Scamps, Guillaume; Hashimoto, Yukio

    2018-03-01

    In a mean-field description of superfluidity, particle number and gauge angle are treated as quasiclassical conjugated variables. This level of description was recently used to describe nuclear reactions around the Coulomb barrier. Important effects of the relative gauge angle between two identical superfluid nuclei (symmetric collisions) on transfer probabilities and fusion barrier have been uncovered. A theory making contact with experiments should at least average over different initial relative gauge-angles. In the present work, we propose a new approach to obtain the multiple pair transfer probabilities between superfluid systems. This method, called phase-space combinatorial (PSC) technique, relies both on phase-space averaging and combinatorial arguments to infer the full pair transfer probability distribution at the cost of multiple mean-field calculations only. After benchmarking this approach in a schematic model, we apply it to the collision 20O+20O at various energies below the Coulomb barrier. The predictions for one pair transfer are similar to results obtained with an approximated projection method, whereas significant differences are found for two pairs transfer. Finally, we investigated the applicability of the PSC method to the contact between nonidentical superfluid systems. A generalization of the method is proposed and applied to the schematic model showing that the pair transfer probabilities are reasonably reproduced. The applicability of the PSC method to asymmetric nuclear collisions is investigated for the 14O+20O collision and it turns out that unrealistically small single- and multiple pair transfer probabilities are obtained. This is explained by the fact that relative gauge angle play in this case a minor role in the particle transfer process compared to other mechanisms, such as equilibration of the charge/mass ratio. We conclude that the best ground for probing gauge-angle effects in nuclear reaction and/or for applying the proposed

  13. Microscopic reversibility and the information contained in the composition vector

    CERN Document Server

    Luetich, J J

    2001-01-01

    The microscopic level of observation is the level where every (hypothetical) transformation is reversible. As during reversible processes no composition information is generated by the system, when transforming composition variables, microscopic reversibility is the other side of the coin. This paper is the fourth member of a tetralogy conceived to give insight into the concept of microscopic reversibility.

  14. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1992-01-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations

  15. Electron microscope studies

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  16. Generalized Heine–Stieltjes and Van Vleck polynomials associated with two-level, integrable BCS models

    International Nuclear Information System (INIS)

    Marquette, Ian; Links, Jon

    2012-01-01

    We study the Bethe ansatz/ordinary differential equation (BA/ODE) correspondence for Bethe ansatz equations that belong to a certain class of coupled, nonlinear, algebraic equations. Through this approach we numerically obtain the generalized Heine–Stieltjes and Van Vleck polynomials in the degenerate, two-level limit for four cases of integrable Bardeen–Cooper–Schrieffer (BCS) pairing models. These are the s-wave pairing model, the p + ip-wave pairing model, the p + ip pairing model coupled to a bosonic molecular pair degree of freedom, and a newly introduced extended d + id-wave pairing model with additional interactions. The zeros of the generalized Heine–Stieltjes polynomials provide solutions of the corresponding Bethe ansatz equations. We compare the roots of the ground states with curves obtained from the solution of a singular integral equation approximation, which allows for a characterization of ground-state phases in these systems. Our techniques also permit the computation of the roots of the excited states. These results illustrate how the BA/ODE correspondence can be used to provide new numerical methods to study a variety of integrable systems. (paper)

  17. SPONGY (SPam ONtoloGY: Email Classification Using Two-Level Dynamic Ontology

    Directory of Open Access Journals (Sweden)

    Seongwook Youn

    2014-01-01

    Full Text Available Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user’s background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1 to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2 to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance.

  18. SPONGY (SPam ONtoloGY): email classification using two-level dynamic ontology.

    Science.gov (United States)

    Youn, Seongwook

    2014-01-01

    Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user's background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1) to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2) to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance.

  19. Testing a Quantum Heat Pump with a Two-Level Spin

    Directory of Open Access Journals (Sweden)

    Luis A. Correa

    2016-04-01

    Full Text Available Once in its non-equilibrium steady state, a nanoscale system coupled to several heat baths may be thought of as a “quantum heat pump”. Depending on the direction of its stationary heat flows, it may function as, e.g., a refrigerator or a heat transformer. These continuous heat devices can be arbitrarily complex multipartite systems, and yet, their working principle is always the same: they are made up of several elementary three-level stages operating in parallel. As a result, it is possible to devise external “black-box” testing strategies to learn about their functionality and performance regardless of any internal details. In particular, one such heat pump can be tested by coupling a two-level spin to one of its “contact transitions”. The steady state of this external probe contains information about the presence of heat leaks and internal dissipation in the device and, also, about the direction of its steady-state heat currents. Provided that the irreversibility of the heat pump is low, one can further estimate its coefficient of performance. These techniques may find applications in the emerging field of quantum thermal engineering, as they facilitate the diagnosis and design optimization of complex thermodynamic cycles.

  20. SPONGY (SPam ONtoloGY): Email Classification Using Two-Level Dynamic Ontology

    Science.gov (United States)

    2014-01-01

    Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user's background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1) to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2) to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance. PMID:25254240

  1. Biopsy Diagnosis of Oral Carcinoma by the Combination of Morphological and Spectral Methods Based on Embedded Relay Lens Microscopic Hyperspectral Imaging System.

    Science.gov (United States)

    Ou-Yang, Mang; Hsieh, Yao-Fang; Lee, Cheng-Chung

    Cytopathological examination through biopsy is very important for carcinoma detection. The embedded relay lens microscopic hyperspectral imaging system (ERL-MHIS) provides a morphological image of a biopsy sample and the spectrum of each pixel in the image simultaneously. Based on the ERL-MHIS, this work develops morphological and spectral methods to diagnose oral carcinoma biopsy. In morphological discrimination, the fractal dimension method is applied to differentiate between normal and abnormal tissues. In spectral identification, normal and cancerous cells are distinguished using five methods. However, the spectra of normal and cancerous cells vary with patient. The diagnostic performances of the five methods are thus not ideal. Hence, the proposed cocktail approach is used to determine the effectiveness of the spectral methods in correlating with the sampling conditions. And then we use a combination of effective spectral methods according to the sample conditions for diagnosing a sample. A total of 68 biopsies from 34 patients are analyzed using the ERL-MHIS. The results demonstrate a sensitivity of 90 ± 4.53 % and a specificity of 87.8 ± 5.21 %. Furthermore, in our survey, this system is the first time utilized to study oral carcinoma biopsies.

  2. Analysis of Morphological Features of Benign and Malignant Breast Cell Extracted From FNAC Microscopic Image Using the Pearsonian System of Curves.

    Science.gov (United States)

    Rajbongshi, Nijara; Bora, Kangkana; Nath, Dilip C; Das, Anup K; Mahanta, Lipi B

    2018-01-01

    Cytological changes in terms of shape and size of nuclei are some of the common morphometric features to study breast cancer, which can be observed by careful screening of fine needle aspiration cytology (FNAC) images. This study attempts to categorize a collection of FNAC microscopic images into benign and malignant classes based on family of probability distribution using some morphometric features of cell nuclei. For this study, features namely area, perimeter, eccentricity, compactness, and circularity of cell nuclei were extracted from FNAC images of both benign and malignant samples using an image processing technique. All experiments were performed on a generated FNAC image database containing 564 malignant (cancerous) and 693 benign (noncancerous) cell level images. The five-set extracted features were reduced to three-set (area, perimeter, and circularity) based on the mean statistic. Finally, the data were fitted to the generalized Pearsonian system of frequency curve, so that the resulting distribution can be used as a statistical model. Pearsonian system is a family of distributions where kappa (κ) is the selection criteria computed as functions of the first four central moments. For the benign group, kappa (κ) corresponding to area, perimeter, and circularity was -0.00004, 0.0000, and 0.04155 and for malignant group it was 1016942, 0.01464, and -0.3213, respectively. Thus, the family of distribution related to these features for the benign and malignant group were different, and therefore, characterization of their probability curve will also be different.

  3. Fingerprint authentication via joint transform correlator and its application in remote access control of a 3D microscopic system

    Science.gov (United States)

    He, Wenqi; Lai, Hongji; Wang, Meng; Liu, Zeyi; Yin, Yongkai; Peng, Xiang

    2014-05-01

    We present a fingerprint authentication scheme based on the optical joint transform correlator (JTC) and further describe its application to the remote access control of a Network-based Remote Laboratory (NRL). It is built to share a 3D microscopy system of our realistic laboratory in Shenzhen University with the remote co-researchers in Stuttgart University. In this article, we would like to focus on the involved security issues, mainly on the verification of various remote visitors to our NRL. By making use of the JTC-based optical pattern recognition technique as well as the Personal Identification Number (PIN), we are able to achieve the aim of authentication and access control for any remote visitors. Note that only the authorized remote visitors could be guided to the Virtual Network Computer (VNC), a cross-platform software, which allows the remote visitor to access the desktop applications and visually manipulate the instruments of our NRL through the internet. Specifically to say, when a remote visitor attempts to access to our NRL, a PIN is mandatory required in advance, which is followed by fingerprint capturing and verification. Only if both the PIN and the fingerprint are correct, can one be regarded as an authorized visitor, and then he/she would get the authority to visit our NRL by the VNC. It is also worth noting that the aforementioned "two-step verification" strategy could be further applied to verify the identity levels of various remote visitors, and therefore realize the purpose of diversified visitor management.

  4. Immobilization of oligonucleotide probes on silicon surfaces using biotin–streptavidin system examined with microscopic and spectroscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Awsiuk, K., E-mail: kamil.awsiuk@uj.edu.pl [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Rysz, J. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Petrou, P. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Budkowski, A. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Bernasik, A. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Kakabakos, S. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece); Marzec, M.M. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Kraków 30-059 (Poland); Raptis, I. [Institute for Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, NCSR “Demokritos”, End Patriarchou Gregoriou Str., Aghia Paraskevi 15310 (Greece)

    2014-01-30

    To immobilize effectively oligonucleotide probes on SiO{sub 2} modified with (3-aminopropyl)triethoxysilane, four procedures based on streptavidin–biotin system are compared with Atomic Force Microscopy, Angle-Resolved X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The first approach involves: adsorption of biotinylated Bovine Serum Albumin, blocking free surface sites with BSA, binding of streptavidin and biotinylated oligonucleotide (b-oligo). Final steps are exchanged in the second procedure with immobilization of preformed streptavidin–b-oligo conjugate. The third approach consists of streptavidin adsorption, blocking with BSA and b-oligo binding. Finally, streptavidin–b-oligo conjugate is immobilized directly within the fourth method. Surface coverage with biomolecules, determined from ARXPS, accords with average AFM height, and is anti-correlated with the intensity of Si+ ions. Higher biomolecular coverage was achieved during the last steps of the first (2.45(±0.38) mg/m{sup 2}) and second (1.31(±0.22) mg/m{sup 2}) approach, as compared to lower surface density resulting from the third (0.58(±0.20) mg/m{sup 2}) and fourth (0.41(±0.11) mg/m{sup 2}) method. Phosphorus atomic concentration indicates effectiveness of oligonucleotide immobilization. Secondary ions intensities, characteristic for oligonucleotides, streptavidin, BSA, and proteins, allow additional insight into overlayer composition. These measurements verify the ARXPS results and show the superiority of the first two immobilization approaches in terms of streptavidin and oligonucleotide density achieved onto the surface.

  5. Immobilization of oligonucleotide probes on silicon surfaces using biotin–streptavidin system examined with microscopic and spectroscopic techniques

    International Nuclear Information System (INIS)

    Awsiuk, K.; Rysz, J.; Petrou, P.; Budkowski, A.; Bernasik, A.; Kakabakos, S.; Marzec, M.M.; Raptis, I.

    2014-01-01

    To immobilize effectively oligonucleotide probes on SiO 2 modified with (3-aminopropyl)triethoxysilane, four procedures based on streptavidin–biotin system are compared with Atomic Force Microscopy, Angle-Resolved X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. The first approach involves: adsorption of biotinylated Bovine Serum Albumin, blocking free surface sites with BSA, binding of streptavidin and biotinylated oligonucleotide (b-oligo). Final steps are exchanged in the second procedure with immobilization of preformed streptavidin–b-oligo conjugate. The third approach consists of streptavidin adsorption, blocking with BSA and b-oligo binding. Finally, streptavidin–b-oligo conjugate is immobilized directly within the fourth method. Surface coverage with biomolecules, determined from ARXPS, accords with average AFM height, and is anti-correlated with the intensity of Si+ ions. Higher biomolecular coverage was achieved during the last steps of the first (2.45(±0.38) mg/m 2 ) and second (1.31(±0.22) mg/m 2 ) approach, as compared to lower surface density resulting from the third (0.58(±0.20) mg/m 2 ) and fourth (0.41(±0.11) mg/m 2 ) method. Phosphorus atomic concentration indicates effectiveness of oligonucleotide immobilization. Secondary ions intensities, characteristic for oligonucleotides, streptavidin, BSA, and proteins, allow additional insight into overlayer composition. These measurements verify the ARXPS results and show the superiority of the first two immobilization approaches in terms of streptavidin and oligonucleotide density achieved onto the surface.

  6. Microscopic nucleon spectral function for finite nuclei featuring two- and three-nucleon short-range correlations: The model versus ab initio calculations for three-nucleon systems

    Science.gov (United States)

    Ciofi degli Atti, Claudio; Mezzetti, Chiara Benedetta; Morita, Hiko

    2017-04-01

    Background: Two-nucleon (2 N ) short-range correlations (SRC) in nuclei have been recently thoroughly investigated, both theoretically and experimentally and the study of three-nucleon (3 N ) SRC, which could provide important information on short-range hadronic structure, is underway. Novel theoretical ideas concerning 2 N and 3 N SRC are put forward in the present paper. Purpose: The general features of a microscopic one-nucleon spectral function which includes the effects of both 2 N and 3 N SRC and its comparison with ab initio spectral functions of the three-nucleon systems are illustrated. Methods: A microscopic and parameter-free one-nucleon spectral function expressed in terms of a convolution integral involving ab initio relative and center-of-mass (c.m.) momentum distributions of a 2 N pair and aimed at describing two- and three-nucleon short-range correlations, is obtained by using: (i) the two-nucleon momentum distributions obtained within ab initio approaches based upon nucleon-nucleon interactions of the Argonne family; (ii) the exact relation between one- and two-nucleon momentum distributions; (iii) the fundamental property of factorization of the nuclear wave function at short internucleon ranges. Results: The comparison between the ab initio spectral function of 3He and the one based upon the convolution integral shows that when the latter contains only two-nucleon short-range correlations the removal energy location of the peaks and the region around them exhibited by the ab initio spectral function are correctly predicted, unlike the case of the high and low removal energy tails; the inclusion of the effects of three-nucleon correlations brings the convolution model spectral function in much better agreement with the ab initio one; it is also found that whereas the three-nucleon short-range correlations dominate the high energy removal energy tail of the spectral function, their effects on the one-nucleon momentum distribution are almost one

  7. Microscope on Mars

    Science.gov (United States)

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  8. The scanning tunneling microscope

    International Nuclear Information System (INIS)

    Salvan, F.

    1986-01-01

    A newly conceived microscope, based on a pure quantum phenomenon, is an ideal tool to study atom by atom the topography and properties of surfaces. Applications are presented: surface ''reconstruction'' of silicon, lamellar compound study, etc... Spectroscopy by tunnel effect will bring important information on electronic properties; it is presented with an application on silicon [fr

  9. Scanning electron microscope

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The principle underlying the design of the scanning electron microscope (SEM), the design and functioning of SEM are described. Its applications in the areas of microcircuitry and materials science are outlined. The development of SEM in India is reviewed. (M.G.B.)

  10. Scanning Electron Microscopic Evaluation of Residual Smear Layer Following Preparation of Curved Root Canals Using Hand Instrumentation or Two Engine-Driven Systems.

    Science.gov (United States)

    Khademi, Abbasali; Saatchi, Masoud; Shokouhi, Mohammad Mehdi; Baghaei, Badri

    2015-01-01

    In this experimental study, the amount of smear layer (SL) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated. Forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to Schneider's method) were divided into three groups (n=16) which were prepared by either the ProTaper Universal file series, Reciproc single file system or hand instrumentation. The canals were intermittently irrigated with 5.25% NaOCl and 17% (ethylenediaminetetraacetic acid) EDTA, followed by distilled water as the final rinse. The roots were split longitudinally and the apical third of the specimens were evaluated under 2500× magnification with a scanning electron microscope (SEM). The mean scores of the SL were calculated and analyzed using the non-parametric Kruskal-Wallis and Mann-Whitney U tests. The mean scores of the SL were 2.00±0.73, 1.94±0.68 and 1.44±0.63 µm for the ProTaper Universal, Reciproc and hand instrumentation, respectively. Mean score of SL was significantly less in the hand instrumentation group than the ProTaper (P=0.027) and Reciproc (P=0.035) groups. The difference between the two engine-driven systems, however, was not significant (P=0.803). The amount of smear layer in the apical third of curved root canals prepared with both engine-driven systems was similar and greater than the hand instrumentation technique. Complete cleanliness was not attained.

  11. Evaluation of the incidence of microcracks caused by Mtwo and ProTaper Next rotary file systems versus the self-adjusting file: A scanning electron microscopic study.

    Science.gov (United States)

    Saha, Suparna Ganguly; Vijaywargiya, Neelam; Saxena, Divya; Saha, Mainak Kanti; Bharadwaj, Anuj; Dubey, Sandeep

    2017-01-01

    To evaluate the incidence of microcrack formation canal preparation with two rotary nickel-titanium systems Mtwo and ProTaper Next along with the self-adjusting file system. One hundred and twenty mandibular premolar teeth were selected. Standardized access cavities were prepared and the canals were manually prepared up to size 20 after coronal preflaring. The teeth were divided into three experimental groups and one control group ( n = 30). Group 1: The canals were prepared using Mtwo rotary files. Group 2: The canals were prepared with ProTaper Next files. Group 3: The canals were prepared with self-adjusting files. Group 4: The canals were unprepared and used as a control. The roots were sectioned horizontally 3, 6, and 9 mm from the apex and examined under a scanning electron microscope to check for the presence of microcracks. The Pearson's Chi-square test was applied. The highest incidence of microcracks were associated with the ProTaper Next group, 80% ( P = 0.00), followed by the Mtwo group, 70% ( P = 0.000), and the least number of microcracks was noted in the self-adjusting file group, 10% ( P = 0.068). No significant difference was found between the ProTaper Next and Mtwo groups ( P = 0.368) while a significant difference was observed between the ProTaper Next and self-adjusting file groups ( P = 0.000) as well as the Mtwo and self-adjusting file groups ( P = 0.000). All nickel-titanium rotary instrument systems were associated with microcracks. However, the self-adjusting file system had significantly fewer microcracks when compared with the Mtwo and ProTaper Next.

  12. Two levels ARIMAX and regression models for forecasting time series data with calendar variation effects

    Science.gov (United States)

    Suhartono, Lee, Muhammad Hisyam; Prastyo, Dedy Dwi

    2015-12-01

    The aim of this research is to develop a calendar variation model for forecasting retail sales data with the Eid ul-Fitr effect. The proposed model is based on two methods, namely two levels ARIMAX and regression methods. Two levels ARIMAX and regression models are built by using ARIMAX for the first level and regression for the second level. Monthly men's jeans and women's trousers sales in a retail company for the period January 2002 to September 2009 are used as case study. In general, two levels of calendar variation model yields two models, namely the first model to reconstruct the sales pattern that already occurred, and the second model to forecast the effect of increasing sales due to Eid ul-Fitr that affected sales at the same and the previous months. The results show that the proposed two level calendar variation model based on ARIMAX and regression methods yields better forecast compared to the seasonal ARIMA model and Neural Networks.

  13. Efficiency analysis on a two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Geng, Pan; Wu, Weimin; Huang, Min

    2013-01-01

    When designing an inverter, an engineer often needs to select and predict the efficiency beforehand. For the standard inverters, plenty of researches are analyzing the power losses and also many software tools are being used for efficiency calculation. In this paper, the efficiency calculation...... for non-conventional inverters with special shoot-through state is introduced and illustrated through the analysis on a special two-level three-phase quasi-soft-switching inverter. Efficiency comparison between the classical two-stage two-level three-phase inverter and the two-level three-phase quasi......-soft-switching inverter is carried out. A 10 kW/380 V prototype is constructed to verify the analysis. The experimental results show that the efficiency of the new inverter is higher than that of the traditional two-stage two- level three-phase inverter....

  14. An EOQ Model with Stock-Dependent Demand under Two Levels of Trade Credit and Time Value of Money

    OpenAIRE

    H.A.O. Jia-Qin; M.O. Jiangtao

    2013-01-01

    Since the value of money changes with time, it is necessary to take account of the influence of time factor in making the replenishment policy. In this study, to investigate the influence of the time value of money to the inventory strategy, an inventory system for deteriorating items with stock-dependent demand is investigated under two levels of trade credit. The method to efficiently determine the optimal cycle time is presented. Numerical examples are provided to demonstrate the model and...

  15. Entanglement Criteria of Two Two-Level Atoms Interacting with Two Coupled Modes

    Science.gov (United States)

    Baghshahi, Hamid Reza; Tavassoly, Mohammad Kazem; Faghihi, Mohammad Javad

    2015-08-01

    In this paper, we study the interaction between two two-level atoms and two coupled modes of a quantized radiation field in the form of parametric frequency converter injecting within an optical cavity enclosed by a medium with Kerr nonlinearity. It is demonstrated that, by applying the Bogoliubov-Valatin canonical transformation, the introduced model is reduced to a well-known form of the generalized Jaynes-Cummings model. Then, under particular initial conditions for the atoms (in a coherent superposition of its ground and upper states) and the fields (in a standard coherent state) which may be prepared, the time evolution of state vector of the entire system is analytically evaluated. In order to understand the degree of entanglement between subsystems (atom-field and atom-atom), the dynamics of entanglement through different measures, namely, von Neumann reduced entropy, concurrence and negativity is evaluated. In each case, the effects of Kerr nonlinearity and detuning parameter on the above measures are numerically analyzed, in detail. It is illustrated that the amount of entanglement can be tuned by choosing the evolved parameters, appropriately.

  16. Two-level image authentication by two-step phase-shifting interferometry and compressive sensing

    Science.gov (United States)

    Zhang, Xue; Meng, Xiangfeng; Yin, Yongkai; Yang, Xiulun; Wang, Yurong; Li, Xianye; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2018-01-01

    A two-level image authentication method is proposed; the method is based on two-step phase-shifting interferometry, double random phase encoding, and compressive sensing (CS) theory, by which the certification image can be encoded into two interferograms. Through discrete wavelet transform (DWT), sparseness processing, Arnold transform, and data compression, two compressed signals can be generated and delivered to two different participants of the authentication system. Only the participant who possesses the first compressed signal attempts to pass the low-level authentication. The application of Orthogonal Match Pursuit CS algorithm reconstruction, inverse Arnold transform, inverse DWT, two-step phase-shifting wavefront reconstruction, and inverse Fresnel transform can result in the output of a remarkable peak in the central location of the nonlinear correlation coefficient distributions of the recovered image and the standard certification image. Then, the other participant, who possesses the second compressed signal, is authorized to carry out the high-level authentication. Therefore, both compressed signals are collected to reconstruct the original meaningful certification image with a high correlation coefficient. Theoretical analysis and numerical simulations verify the feasibility of the proposed method.

  17. Fabrication of a two-level tumor bone repair biomaterial based on a rapid prototyping technique

    Energy Technology Data Exchange (ETDEWEB)

    Kai He; Yan Yongnian; Zhang Renji; Wang Xiaohong [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education and Center of Organ Manufacturing, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang Xinluan; Madhukar, Kumta Shekhar; Qin Ling [Department of Orthoapedics and Traumatology, The Chinese University of Hong Kong. Shatin, NT (Hong Kong)], E-mail: wangxiaohong@tsinghua.edu.cn, E-mail: kumta@cuhk.edu.hk, E-mail: qin@ort.cuhk.edu.hk

    2009-06-01

    After the removal of the giant cell tumor (GCT) of bone, it is necessary to fill the defects with adequate biomaterials. A new functional bone repair material with both stimulating osteoblast growth and inhibiting osteoclast activity has been developed with phosphorylated chitosan (P-chitosan) and disodium (1 {yields} 4)-2-deoxy-2-sulfoamino-{beta}-D-glucopyranuronan (S-chitosan) as the additives of poly(lactic acid-co-glycolic acid) (PLGA)/calcium phosphate (TCP) scaffolds based on a double-nozzle low-temperature deposition manufacturing technique. A computer-assisted design model was used and the optimal fabrication parameters were determined through the manipulation of a pure PLGA/TCP system. The microscopic structures, water absorbability and mechanical properties of the samples with different P-chitosan and S-chitosan concentrations were characterized correspondingly. The results suggested that this unique composite porous scaffold material is a potential candidate for the repair of large bone defects after a surgical removal of GCT.

  18. Simultaneous Scanning Electron Microscope Imaging of Topographical and Chemical Contrast Using In-Lens, In-Column, and Everhart-Thornley Detector Systems.

    Science.gov (United States)

    Zhang, Xinming; Cen, Xi; Ravichandran, Rijuta; Hughes, Lauren A; van Benthem, Klaus

    2016-06-01

    The scanning electron microscope provides a platform for subnanometer resolution characterization of material morphology with excellent topographic and chemical contrast dependent on the used detectors. For imaging applications, the predominantly utilized signals are secondary electrons (SEs) and backscattered electrons (BSEs) that are emitted from the sample surface. Recent advances in detector technology beyond the traditional Everhart-Thornley geometry have enabled the simultaneous acquisition and discrimination of SE and BSE signals. This study demonstrates the imaging capabilities of a recently introduced new detector system that consists of the combination of two in-lens (I-L) detectors and one in-column (I-C) detector. Coupled with biasing the sample stage to reduce electron-specimen interaction volumes, this trinity of detector geometry allows simultaneous acquisition of signals to distinguish chemical contrast from topographical changes of the sample, including the identification of surface contamination. The I-C detector provides 4× improved topography, whereas the I-L detector closest to the sample offers excellent simultaneous chemical contrast imaging while not limiting the minimization of working distance to obtain optimal lateral resolution. Imaging capabilities and contrast mechanisms for all three detectors are discussed quantitatively in direct comparison to each other and the conventional Everhart-Thornley detector.

  19. Anti-drift and auto-alignment mechanism for an astigmatic atomic force microscope system based on a digital versatile disk optical head.

    Science.gov (United States)

    Hwu, E-T; Illers, H; Wang, W-M; Hwang, I-S; Jusko, L; Danzebrink, H-U

    2012-01-01

    In this work, an anti-drift and auto-alignment mechanism is applied to an astigmatic detection system (ADS)-based atomic force microscope (AFM) for drift compensation and cantilever alignment. The optical path of the ADS adopts a commercial digital versatile disc (DVD) optical head using the astigmatic focus error signal. The ADS-based astigmatic AFM is lightweight, compact size, low priced, and easy to use. Furthermore, the optical head is capable of measuring sub-atomic displacements of high-frequency AFM probes with a sub-micron laser spot (~570 nm, FWHM) and a high-working bandwidth (80 MHz). Nevertheless, conventional DVD optical heads suffer from signal drift problems. In a previous setup, signal drifts of even thousands of nanometers had been measured. With the anti-drift and auto-alignment mechanism, the signal drift is compensated by actuating a voice coil motor of the DVD optical head. A nearly zero signal drift was achieved. Additional benefits of this mechanism are automatic cantilever alignment and simplified design.

  20. Realisation of a ultra-high vacuum system and technique development of microscopical emitters preparation in silicium. First measurements of field emission current and field photoemission

    International Nuclear Information System (INIS)

    El Manouni, A.

    1990-12-01

    The development of research in the domain of photocathode (electron sources) illuminated by laser light to produce intense multiple bunches of electrons in short time is needed by many applications as linear collider e + e - , free electron laser, lasertron, etc... In this way, after a study of field emission, of photoemission and of photofield emission, we prepared microscopical emitters in silicium heavy and weakly doped a boron using a technique of microlithography. Then, we realized a system of ultra-high vacuum of studying property of emission from photocathodes realized. The experiment results obtained in field emission and photofield emission have shown that a behaviour unexpected for P-silicium tips array compared to P + -silicon tips array. With P-type silicon, a quantum yield of 21 percent has been measured for laser power of 140 mW and for applied field of 1.125 x 10 7 V/m and an instantaneous response to laser light beam has been observed. It has been noted that presence of oxyde at the surface of photocathode limits extensively the emission current. The fluctuations of emission current are due to quality of vacuum [fr

  1. Comparison of endoscope- versus microscope-assisted resection of deep-seated intracranial lesions using a minimally invasive port retractor system.

    Science.gov (United States)

    Hong, Christopher S; Prevedello, Daniel M; Elder, J Bradley

    2016-03-01

    Tubular brain retractors may improve access to deep-seated brain lesions while potentially reducing the risks of collateral neurological injury associated with standard microsurgical approaches. Here, microscope-assisted resection of lesions using tubular retractors is assessed to determine if it is superior to endoscope-assisted surgery due to the technological advancements associated with modern tubular ports and surgical microscopes. Following institutional approval of the tubular port, data obtained from the initial 20 patients to undergo transportal resection of deep-seated brain lesions were analyzed in this study. The pathological entities of the resected tissues included metastatic tumors (8 patients), glioma (7), meningioma (1), neurocytoma (1), radiation necrosis (1), primitive neuroectodermal tumor (1), and hemangioblastoma (1). Surgery incorporated endoscopic (5 patients) or microscopic (15) assistance. The locations included the basal ganglia (11 patients), cerebellum (4), frontal lobe (2), temporal lobe (2), and parietal lobe (1). Cases were reviewed for neurological outcomes, extent of resection (EOR), and complications. Technical data for the port, surgical microscope, and endoscope were analyzed. EOR was considered total in 14 (70%), near total (> 95%) in 4 (20%), and subtotal (microscope rather than the endoscope due to a wider and 3D field of view. Improved microscope optics and tubular retractor design allows for binocular vision with improved lighting for the resection of deep-seated brain lesions.

  2. Occupational concerns associated with regular use of microscope

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2014-08-01

    Full Text Available Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Results: Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11–15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15–30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. Conclusions: The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

  3. Occupational concerns associated with regular use of microscope.

    Science.gov (United States)

    Jain, Garima; Shetty, Pushparaja

    2014-08-01

    Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. a questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11-15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15-30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

  4. Microscopic nuclear dissipation. Pt. 2

    International Nuclear Information System (INIS)

    Yannouleas, C.; Dworzecka, M.; Griffin, J.J.

    1983-01-01

    We have formulated a microscopic, nonperturbative, time reversible model which exhibits a dissipative decay of collective motion for times short compared to the system's Poincare time. The model assumes an RPA approximate description of the initial collective state within a restricted subspace, then traces its time evolution when an additional subspace is coupled to the restricted subspace by certain simplified matrix elements. It invokes no statistical assumptions. The damping of the collective motion occurs via real transitions from the collective state to other more complicated nuclear states of the same energy. It corresponds therefore to the so called 'one-body' long mean free path limit of nuclear dissipation when the collective state describes a surface vibration. When the simplest RPA approximation is used, this process associates the dissipation with the escape width for direct particle emission to the continuum. When the more detailed second RPA is used, it associates the dissipation with the spreading width for transitions to the 2p-2h components of the nuclear compound states as well. The energy loss rate for sharp n-phonon initial states is proportional to the total collective energy, unlike the dissipation of a classical damped oscillator, where it is proportional to the kinetic energy only. However, for coherent, multi-phonon wave packets, which explicitly describe the time-dependent oscillations of the mean field, dissipation proportional only to the kinetic energy is obtained. Canonical coordinates for the collective degree of freedom are explicitly introduced and a nonlinear frictional hamiltonian to describe such systems is specified by the requirement that it yield the same time dependence for the collective motion as the microscopic model. Thus, for the first time a descriptive nonlinear hamiltonian is derived explicitly from the underlying microscopic model of a nuclear system. (orig.)

  5. Neuromorphic Data Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Naegle, John H.; Suppona, Roger A.; Aimone, James Bradley; James, Conrad D.; Follett, David R.; Townsend, Duncan C.M.; Follett, Pamela L.; Karpman, Gabe D.

    2017-08-01

    In 2016, Lewis Rhodes Labs, (LRL), shipped the first commercially viable Neuromorphic Processing Unit, (NPU), branded as a Neuromorphic Data Microscope (NDM). This product leverages architectural mechanisms derived from the sensory cortex of the human brain to efficiently implement pattern matching. LRL and Sandia National Labs have optimized this product for streaming analytics, and demonstrated a 1,000x power per operation reduction in an FPGA format. When reduced to an ASIC, the efficiency will improve to 1,000,000x. Additionally, the neuromorphic nature of the device gives it powerful computational attributes that are counterintuitive to those schooled in traditional von Neumann architectures. The Neuromorphic Data Microscope is the first of a broad class of brain-inspired, time domain processors that will profoundly alter the functionality and economics of data processing.

  6. Microscopic dynamical Casimir effect

    Science.gov (United States)

    Souza, Reinaldo de Melo e.; Impens, François; Neto, Paulo A. Maia

    2018-03-01

    We consider an atom in its ground state undergoing a nonrelativistic oscillation in free space. The interaction with the electromagnetic quantum vacuum leads to two effects to leading order in perturbation theory. When the mechanical frequency is larger than the atomic transition frequency, the dominant effect is the motion-induced transition to an excited state with the emission of a photon carrying the excess energy. We compute the angular distribution of emitted photons and the excitation rate. On the other hand, when the mechanical frequency is smaller than the transition frequency, the leading-order effect is the parametric emission of photon pairs, which constitutes the microscopic counterpart of the dynamical Casimir effect. We discuss the properties of the microscopic dynamical Casimir effect and build a connection with the photon production by an oscillating macroscopic metallic mirror.

  7. A pragmatic guide to multiphoton microscope design

    Science.gov (United States)

    Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

    2016-01-01

    Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

  8. Microscopic enteritis: Bucharest consensus.

    Science.gov (United States)

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-03-07

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy.

  9. Asynchronous Two-Level Checkpointing Scheme for Large-Scale Adjoints in the Spectral-Element Solver Nek5000

    Energy Technology Data Exchange (ETDEWEB)

    Schanen, Michel; Marin, Oana; Zhang, Hong; Anitescu, Mihai

    2016-01-01

    Adjoints are an important computational tool for large-scale sensitivity evaluation, uncertainty quantification, and derivative-based optimization. An essential component of their performance is the storage/recomputation balance in which efficient checkpointing methods play a key role. We introduce a novel asynchronous two-level adjoint checkpointing scheme for multistep numerical time discretizations targeted at large-scale numerical simulations. The checkpointing scheme combines bandwidth-limited disk checkpointing and binomial memory checkpointing. Based on assumptions about the target petascale systems, which we later demonstrate to be realistic on the IBM Blue Gene/Q system Mira, we create a model of the expected performance of our checkpointing approach and validate it using the highly scalable Navier-Stokes spectralelement solver Nek5000 on small to moderate subsystems of the Mira supercomputer. In turn, this allows us to predict optimal algorithmic choices when using all of Mira. We also demonstrate that two-level checkpointing is significantly superior to single-level checkpointing when adjoining a large number of time integration steps. To our knowledge, this is the first time two-level checkpointing had been designed, implemented, tuned, and demonstrated on fluid dynamics codes at large scale of 50k+ cores.

  10. The Digital Microscope and Its Image Processing Utility

    Directory of Open Access Journals (Sweden)

    Tri Wahyu Supardi

    2011-12-01

    Full Text Available Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.

  11. Solutions of the two-level problem in terms of biconfluent Heun functions

    Energy Technology Data Exchange (ETDEWEB)

    Ishkhanyan, Artur [Engineering Center of Armenian National Academy of Sciences, Ashtarak (Armenia)]. E-mail: artur@ec.sci.am; Suominen, Kalle-Antti [Helsinki Institute of Physics, Helsinki (Finland); Department of Applied Physics, University of Turku, Turku (Finland)

    2001-08-17

    Five four-parametric classes of quantum mechanical two-level models permitting solutions in terms of the biconfluent Heun function are derived. Three of these classes are generalizations of the well known classes of Landau-Zener, Nikitin and Crothers. It is shown that two other classes describe super- and sublinear and essentially nonlinear level crossings, as well as processes with three crossing points. In particular, these classes include two-level models where the field amplitude is constant and the detuning varies as {delta}{sub 0}t+{delta}{sub 2}t{sup 3} or {approx}t{sup 1/3}. For the essentially nonlinear cubic-crossing model, {delta}{sub t}{approx}{delta}{sub 2}t{sup 3}, the general solution of the two-level problem is shown to be expressed as series of confluent hypergeometric functions. (author)

  12. Two-Level Solutions to Exponentially Complex Problems in Glass Science

    DEFF Research Database (Denmark)

    Mauro, John C.; Smedskjær, Morten Mattrup

    Glass poses an especially challenging problem for physicists. The key to making progress in theoretical glass science is to extract the key physics governing properties of practical interest. In this spirit, we discuss several two-level solutions to exponentially complex problems in glass science....... Topological constraint theory, originally developed by J.C. Phillips, is based on a two-level description of rigid and floppy modes in a glass network and can be used to derive quantitatively accurate and analytically solvable models for a variety of macroscopic properties. The temperature dependence...... that captures both primary and secondary relaxation modes. Such a model also offers the ability to calculate the distinguishability of particles during glass transition and relaxation processes. Two-level models can also be used to capture the distribution of various network-forming species in mixed...

  13. Method and system for in vivo measurement of bone tissue using a two level energy source

    International Nuclear Information System (INIS)

    Fletcher, J.C.; Cameron, J.R.; Judy, P.F.

    1976-01-01

    Methods and apparatus are provided for radiologically determining the bone mineral content of living human bone tissue independently of the concurrent presence of adipose and other soft tissues. A target section of the body of the subject is irradiated with a beam of penetrative radiations of preselected energy to determine the attenuation of such beam with respect to the intensity of each of two radiations of different predetermined energy levels. The resulting measurements are then employed to determine bone mineral content according to the following relationship: I = (I 0 ) exp [(μBM/sup M/BM) - (μST/sup M/ST)] wherein I 0 is the unattentuated intensity of the radiations in the beam, μ is the mass attenuation coefficient, M is mass in g/cm 2

  14. Two-level system in spin baths: Non-adiabatic dynamics and heat transport

    Science.gov (United States)

    Segal, Dvira

    2014-04-01

    We study the non-adiabatic dynamics of a two-state subsystem in a bath of independent spins using the non-interacting blip approximation, and derive an exact analytic expression for the relevant memory kernel. We show that in the thermodynamic limit, when the subsystem-bath coupling is diluted (uniformly) over many (infinite) degrees of freedom, our expression reduces to known results, corresponding to the harmonic bath with an effective, temperature-dependent, spectral density function. We then proceed and study the heat current characteristics in the out-of-equilibrium spin-spin-bath model, with a two-state subsystem bridging two thermal spin-baths of different temperatures. We compare the behavior of this model to the case of a spin connecting boson baths, and demonstrate pronounced qualitative differences between the two models. Specifically, we focus on the development of the thermal diode effect, and show that the spin-spin-bath model cannot support it at weak (subsystem-bath) coupling, while in the intermediate-strong coupling regime its rectifying performance outplays the spin-boson model.

  15. Method and system for in vivo measurement of bone tissue using a two level energy source

    Science.gov (United States)

    Cameron, J. R.; Judy, P. F. (Inventor)

    1976-01-01

    Methods and apparatus are provided for radiologically determining the bone mineral content of living human bone tissue independently of the concurrent presence of adipose and other soft tissues. A target section of the body of the subject is irradiated with a beam of penetrative radiations of preselected energy to determine the attenuation of such beam with respect to the intensity of each of two radiations of different predetermined energy levels. The resulting measurements are then employed to determine bone mineral content.

  16. Two-level system in spin baths: Non-adiabatic dynamics and heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Segal, Dvira [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S 3H6 (Canada)

    2014-04-28

    We study the non-adiabatic dynamics of a two-state subsystem in a bath of independent spins using the non-interacting blip approximation, and derive an exact analytic expression for the relevant memory kernel. We show that in the thermodynamic limit, when the subsystem-bath coupling is diluted (uniformly) over many (infinite) degrees of freedom, our expression reduces to known results, corresponding to the harmonic bath with an effective, temperature-dependent, spectral density function. We then proceed and study the heat current characteristics in the out-of-equilibrium spin-spin-bath model, with a two-state subsystem bridging two thermal spin-baths of different temperatures. We compare the behavior of this model to the case of a spin connecting boson baths, and demonstrate pronounced qualitative differences between the two models. Specifically, we focus on the development of the thermal diode effect, and show that the spin-spin-bath model cannot support it at weak (subsystem-bath) coupling, while in the intermediate-strong coupling regime its rectifying performance outplays the spin-boson model.

  17. Lambda-Based Data Processing Architecture for Two-Level Load Forecasting in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Gde Dharma Nugraha

    2018-03-01

    Full Text Available Building energy management systems (BEMS have been intensively used to manage the electricity consumption of residential buildings more efficiently. However, the dynamic behavior of the occupants introduces uncertainty problems that affect the performance of the BEMS. To address this uncertainty problem, the BEMS may implement load forecasting as one of the BEMS modules. Load forecasting utilizes historical load data to compute model predictions for a specific time in the future. Recently, smart meters have been introduced to collect electricity consumption data. Smart meters not only capture aggregation data, but also individual data that is more frequently close to real-time. The processing of both smart meter data types for load forecasting can enhance the performance of the BEMS when confronted with uncertainty problems. The collection of smart meter data can be processed using a batch approach for short-term load forecasting, while the real-time smart meter data can be processed for very short-term load forecasting, which adjusts the short-term load forecasting to adapt to the dynamic behavior of the occupants. This approach requires different data processing techniques for aggregation and individual of smart meter data. In this paper, we propose Lambda-based data processing architecture to process the different types of smart meter data and implement the two-level load forecasting approach, which combines short-term and very short-term load forecasting techniques on top of our proposed data processing architecture. The proposed approach is expected to enhance the BEMS to address the uncertainty problem in order to process data in less time. Our experiment showed that the proposed approaches improved the accuracy by 7% compared to a typical BEMS with only one load forecasting technique, and had the lowest computation time when processing the smart meter data.

  18. Kir2.1 channels set two levels of resting membrane potential with inward rectification.

    Science.gov (United States)

    Chen, Kuihao; Zuo, Dongchuan; Liu, Zheng; Chen, Haijun

    2018-04-01

    Strong inward rectifier K + channels (Kir2.1) mediate background K + currents primarily responsible for maintenance of resting membrane potential. Multiple types of cells exhibit two levels of resting membrane potential. Kir2.1 and K2P1 currents counterbalance, partially accounting for the phenomenon of human cardiomyocytes in subphysiological extracellular K + concentrations or pathological hypokalemic conditions. The mechanism of how Kir2.1 channels contribute to the two levels of resting membrane potential in different types of cells is not well understood. Here we test the hypothesis that Kir2.1 channels set two levels of resting membrane potential with inward rectification. Under hypokalemic conditions, Kir2.1 currents counterbalance HCN2 or HCN4 cation currents in CHO cells that heterologously express both channels, generating N-shaped current-voltage relationships that cross the voltage axis three times and reconstituting two levels of resting membrane potential. Blockade of HCN channels eliminated the phenomenon in K2P1-deficient Kir2.1-expressing human cardiomyocytes derived from induced pluripotent stem cells or CHO cells expressing both Kir2.1 and HCN2 channels. Weakly inward rectifier Kir4.1 or inward rectification-deficient Kir2.1•E224G mutant channels do not set such two levels of resting membrane potential when co-expressed with HCN2 channels in CHO cells or when overexpressed in human cardiomyocytes derived from induced pluripotent stem cells. These findings demonstrate a common mechanism that Kir2.1 channels set two levels of resting membrane potential with inward rectification by balancing inward currents through different cation channels such as hyperpolarization-activated HCN channels or hypokalemia-induced K2P1 leak channels.

  19. A Two-Level Cache for Distributed Information Retrieval in Search Engines

    Directory of Open Access Journals (Sweden)

    Weizhe Zhang

    2013-01-01

    Full Text Available To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users’ logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  20. A two-level cache for distributed information retrieval in search engines.

    Science.gov (United States)

    Zhang, Weizhe; He, Hui; Ye, Jianwei

    2013-01-01

    To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users' logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  1. Strong nonlinearity-induced correlations for counterpropagating photons scattering on a two-level emitter

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara; Mørk, Jesper

    2015-01-01

    We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could be quanti......We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could...

  2. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian; Shao Bin; Zou Jian

    2009-01-01

    In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.

  3. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    International Nuclear Information System (INIS)

    Jian, Zhang; Bin, Shao; Jian, Zou

    2009-01-01

    In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

  4. Atomic Force Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  5. Solid state optical microscope

    Science.gov (United States)

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  6. A frameless stereotaxic operating microscope for neurosurgery

    International Nuclear Information System (INIS)

    Friets, E.M.; Strohbehn, J.W.; Hatch, J.F.; Roberts, D.W.

    1989-01-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given

  7. A frameless stereotaxic operating microscope for neurosurgery.

    Science.gov (United States)

    Friets, E M; Strohbehn, J W; Hatch, J F; Roberts, D W

    1989-06-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given.

  8. Experimental Research into the Two-Level Cylindrical Cyclone with a Different Number of Channels

    Directory of Open Access Journals (Sweden)

    Egidijus Baliukas

    2014-10-01

    Full Text Available The multichannel two-level cyclone has been designed for separating solid particles from airflow and built at the Laboratory of Environmental Protection Technologies of Vilnius Gediminas Technical University. The conducted research is aimed at determining air flow distribution at two levels and channels of the multichannel cyclone. The multifunctional meter Testo-400 and the dynamic Pitot tube have been used form easuring air flow rates in the channels. The obtained results show that the equal volume of air gets into two levels installed inside the cyclone, and rates are distributed equally in the channels of these levels. The maximum air flow rate is recorded in the first channel and occurs when half-rings are set in such positions so that 75% of air flow returns to the previous channel. The biggest aerodynamic resistance is 1660 Pa and has been recorded in the cyclone having eight channels under air flow distribution ratio 75/25. The highest air purification efficiency has been observed in the two-level six-channel cyclone under air flow distribution ratio 75/25. The effectiveness of separating granite particles is 92.1% and that of wood particles – 91.1 when the particles are up to 20 μm in diameter.

  9. Polynomial pseudosupersymmetry underlying a two-level atom in an external electromagnetic field

    International Nuclear Information System (INIS)

    Samsonov, B.F.; Shamshutdinova, V.V.; Gitman, D.M.

    2005-01-01

    Chains of transformations introduced previously were studied in order to obtain electric fields with a time-dependent frequency for which the equation of motion of a two-level atom in the presence of these fields can be solved exactly. It is shown that a polynomial pseudosupersymmetry may be associated to such chains

  10. Ultimate temperature for laser cooling of two-level neutral atoms

    International Nuclear Information System (INIS)

    Bagnato, V.S.; Zilio, S.C.

    1989-01-01

    We present a simple pedagogical method to evaluate the minimum attainable temperature for laser cooling of two-level neutral atoms. Results are given as a function of the laser detuning and intensity. We also discuss the use of this approach to predict the minimum temperature of neutral atoms confined in magnetic traps. (author) [pt

  11. An Owen-type value for games with two-level communication structures

    NARCIS (Netherlands)

    van den Brink, René; Khmelnitskaya, Anna Borisovna; van der Laan, Gerard

    We introduce an Owen-type value for games with two-level communication structure, which is a structure where the players are partitioned into a coalition structure such that there exists restricted communication between as well as within the a priori unions of the coalition structure. Both types of

  12. Reactive Power Impact on Lifetime Prediction of Two-level Wind Power Converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, M.

    2013-01-01

    The influence of reactive power injection on the dominating two-level wind power converter is investigated and compared in terms of power loss and thermal behavior. Then the lifetime of both the partial-scale and full-scale power converter is estimated based on the widely used Coffin-Manson model...

  13. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2012-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  14. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2013-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  15. Localization of a two-level atom via the absorption spectrum

    International Nuclear Information System (INIS)

    Xu, Jun; Hu, Xiang-Ming

    2007-01-01

    We show that it is possible to localize a two-level atom as it passes through a standing-wave field by measuring the probe-field absorption. There is 50% detecting probability of the atom at the nodes of the standing-wave field in the subwavelength domain when the probe field is tuned resonant with the atomic transition

  16. Efficient two-level preconditionined conjugate gradient method on the GPU

    NARCIS (Netherlands)

    Gupta, R.; Van Gijzen, M.B.; Vuik, K.

    2011-01-01

    We present an implementation of Two-Level Preconditioned Conjugate Gradient Method for the GPU. We investigate a Truncated Neumann Series based preconditioner in combination with deflation and compare it with Block Incomplete Cholesky schemes. This combination exhibits fine-grain parallelism and

  17. A spatial scan statistic for nonisotropic two-level risk cluster.

    Science.gov (United States)

    Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie

    2012-01-30

    Spatial scan statistic methods are commonly used for geographical disease surveillance and cluster detection. The standard spatial scan statistic does not model any variability in the underlying risks of subregions belonging to a detected cluster. For a multilevel risk cluster, the isotonic spatial scan statistic could model a centralized high-risk kernel in the cluster. Because variations in disease risks are anisotropic owing to different social, economical, or transport factors, the real high-risk kernel will not necessarily take the central place in a whole cluster area. We propose a spatial scan statistic for a nonisotropic two-level risk cluster, which could be used to detect a whole cluster and a noncentralized high-risk kernel within the cluster simultaneously. The performance of the three methods was evaluated through an intensive simulation study. Our proposed nonisotropic two-level method showed better power and geographical precision with two-level risk cluster scenarios, especially for a noncentralized high-risk kernel. Our proposed method is illustrated using the hand-foot-mouth disease data in Pingdu City, Shandong, China in May 2009, compared with two other methods. In this practical study, the nonisotropic two-level method is the only way to precisely detect a high-risk area in a detected whole cluster. Copyright © 2011 John Wiley & Sons, Ltd.

  18. Two-Level Designs to Estimate All Main Effects and Two-Factor Interactions

    NARCIS (Netherlands)

    Eendebak, P.T.; Schoen, E.D.

    2017-01-01

    We study the design of two-level experiments with N runs and n factors large enough to estimate the interaction model, which contains all the main effects and all the two-factor interactions. Yet, an effect hierarchy assumption suggests that main effect estimation should be given more prominence

  19. Lens Systems Incorporating A Zero Power Corrector Part 3 New Four-Element Microscope Objectives With Flat Field Or High Power

    Science.gov (United States)

    Klee, H. W.; McDowell, M. W.

    1986-02-01

    The use of the zero power corrector concept has been extended to the design of microscope objectives. Several four and five-element designs are described which include a flat field 10x design of 0.25 numerical aperture and a 40x design of 0.65 numerical aperture.

  20. Photo induced multiple fragmentation of atoms and molecules: Dynamics of Coulombic many-particle systems studied with the COLTRIMS reaction microscope

    International Nuclear Information System (INIS)

    Czasch, A.; Schmidt, L.Ph.H.; Jahnke, T.; Weber, Th.; Jagutzki, O.; Schoessler, S.; Schoeffler, M.S.; Doerner, R.; Schmidt-Boecking, H.

    2005-01-01

    Many-particle dynamics in atomic and molecular physics has been investigated by using the COLTRIMS reaction microscope. The COLTRIMS technique visualizes photon and ion induced many-particle fragmentation processes in the eV and milli-eV regime. It reveals the complete momentum pattern in atomic and molecular many-particle reactions comparable to the bubble chamber in nuclear physics

  1. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  2. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  3. Microscopical advances in assisted reproduction.

    Science.gov (United States)

    Baccetti, B

    2004-01-01

    In a series of papers carried out by this laboratory it was demonstrated that the quality of sterile males sperm, assessed submicroscopically and mathematically, is closely correlated with the success of the various procedures of assisted reproduction. If we attempt to select hypothetically optimal spermatozoa destined to the ICSI by light inverted microscopy, a considerable amount of ultrastructural information is lost and our selection is merely based on the motility. In this study we apply polarization microscopy to the ICSI technique, introducing polarizing and analyzing lenses in an inverted microscope model, operating in a transparent container. The retardation of the birefringence in the various organelles is evaluated by compensators, and the images are transmitted to a video system, and stored in a computer. Spermatozoa are maintained alive and perfectly motile in this polarizing inverted microscope, and the character of the birefringence is the same as in fixed and sectioned biological material examined by polarization microscopy. The birefringence of the sperm structures allows a sperm analysis closer to TEM than to phase contrast light microscopy analysis.

  4. Visualizing 3-D microscopic specimens

    Science.gov (United States)

    Forsgren, Per-Ola; Majlof, Lars L.

    1992-06-01

    The confocal microscope can be used in a vast number of fields and applications to gather more information than is possible with a regular light microscope, in particular about depth. Compared to other three-dimensional imaging devices such as CAT, NMR, and PET, the variations of the objects studied are larger and not known from macroscopic dissections. It is therefore important to have several complementary ways of displaying the gathered information. We present a system where the user can choose display techniques such as extended focus, depth coding, solid surface modeling, maximum intensity and other techniques, some of which may be combined. A graphical user interface provides easy and direct control of all input parameters. Motion and stereo are available options. Many three- dimensional imaging devices give recordings where one dimension has different resolution and sampling than the other two which requires interpolation to obtain correct geometry. We have evaluated algorithms with interpolation in object space and in projection space. There are many ways to simplify the geometrical transformations to gain performance. We present results of some ways to simplify the calculations.

  5. On the microscopic foundation of scattering theory

    International Nuclear Information System (INIS)

    Moser, T.

    2007-01-01

    The aim of the thesis is to give a contribution to the microscopic foundation of scattering theory, i. e. to show, how the asymptotic formalism of scattering theory with objects like the S-matrix as well the initial and final asymptotics ψ in and ψ out can be derived from a microscopic description of the basic system. First the final statistics from a N-particle system through farly distant surfaces is derived. Thereafter we confine us to the 1-particle scattering and apply the final statistics in order to derive the scattering cross section from a microscopical description of the scattering situation. The basing dynamics are Bohm's mechanics, a theory on the motion of point particles, which reproduces all results of nonrelativistic quantum mechanics

  6. Entropy squeezing for a two-level atom in the Jaynes-Cummings model with an intensity-depend coupling

    Institute of Scientific and Technical Information of China (English)

    李春先; 方卯发

    2003-01-01

    We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.

  7. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  8. Microscopic entropy and nonlocality

    International Nuclear Information System (INIS)

    Karpov, E.; Ordonets, G.; Petroskij, T.; Prigozhin, I.

    2003-01-01

    We have obtained a microscopic expression for entropy in terms of H function based on nonunitary Λ transformation which leads from the time evolution as a unitary group to a Markovian dynamics and unifies the reversible and irreversible aspects of quantum mechanics. This requires a new representation outside the Hilbert space. In terms of H, we show the entropy production and the entropy flow during the emission and absorption of radiation by an atom. Analyzing the time inversion experiment, we emphasize the importance of pre- and postcollisional correlations, which break the symmetry between incoming and outgoing waves. We consider the angle dependence of the H function in a three-dimensional situation. A model including virtual transitions is discussed in a subsequent paper

  9. Designs for a quantum electron microscope.

    Science.gov (United States)

    Kruit, P; Hobbs, R G; Kim, C-S; Yang, Y; Manfrinato, V R; Hammer, J; Thomas, S; Weber, P; Klopfer, B; Kohstall, C; Juffmann, T; Kasevich, M A; Hommelhoff, P; Berggren, K K

    2016-05-01

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This 'quantum weirdness' could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or "quantum electron microscope". A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Analysis of stationary availability factor of two-level backbone computer networks with arbitrary topology

    Science.gov (United States)

    Rahman, P. A.

    2018-05-01

    This scientific paper deals with the two-level backbone computer networks with arbitrary topology. A specialized method, offered by the author for calculation of the stationary availability factor of the two-level backbone computer networks, based on the Markov reliability models for the set of the independent repairable elements with the given failure and repair rates and the methods of the discrete mathematics, is also discussed. A specialized algorithm, offered by the author for analysis of the network connectivity, taking into account different kinds of the network equipment failures, is also observed. Finally, this paper presents an example of calculation of the stationary availability factor for the backbone computer network with the given topology.

  11. Two-Level Iteration Penalty Methods for the Navier-Stokes Equations with Friction Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2013-01-01

    Full Text Available This paper presents two-level iteration penalty finite element methods to approximate the solution of the Navier-Stokes equations with friction boundary conditions. The basic idea is to solve the Navier-Stokes type variational inequality problem on a coarse mesh with mesh size H in combining with solving a Stokes, Oseen, or linearized Navier-Stokes type variational inequality problem for Stokes, Oseen, or Newton iteration on a fine mesh with mesh size h. The error estimate obtained in this paper shows that if H, h, and ε can be chosen appropriately, then these two-level iteration penalty methods are of the same convergence orders as the usual one-level iteration penalty method.

  12. A modified two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Liu, Yusheng; Wu, Weimin; Blaabjerg, Frede

    2014-01-01

    A traditional Voltage Source Inverter (VSI) has higher efficiency than a Current Voltage Source (CSI) due to the less conduction power loss. However, the reverse recovery of the free-wheeling diode limits the efficiency improvement for the silicon devices based hard-switching VSI. The traditional...... quasi-soft-switching inverter can alternate between VSI and CSI by using a proper control scheme and thereby reduce the power losses caused by the reverse recovery of the free-wheeling diode. Nevertheless, slightly extra conduction power loss of the auxiliary switch is also introduced. In order...... to reduce the extra conduction power loss and the voltage stress across the DC-link capacitor, a modified two-level three-phase quasi-soft-switching inverter is proposed by using a SiC MOSFET instead of an IGBT. The principle of the modified two-level three-phase quasi-soft-switching inverter is analyzed...

  13. Revisional Surgery for Hallux Valgus with Serial Osteotomies at Two Levels

    Directory of Open Access Journals (Sweden)

    Jason B. T. Lim

    2011-01-01

    Full Text Available The aetiology and form of hallux valgus (HV is varied with many corrective procedures described. We report a 39-year-old woman, previously treated with a Chevron osteotomy, who presented with recurrent right HV, metatarsus primus varus, and associated bunion. Osteotomies were performed at two levels as a revisional procedure. This report highlights (1 limitations of the Chevron osteotomy and (2 the revisional procedure of the two level osteotomies: (i proximal opening-wedge basal osteotomy and (ii distal short Scarf with medial closing wedges. If a Chevron osteotomy is used inappropriately, for example, in an attempt to correct too large a deformity, it may angulate laterally causing a malunion with an increased distal metatarsal articular angle. Secondly, it is feasible to correct this combined deformity using a combination of proximal opening-wedge and distal short Scarf osteotomies.

  14. Urea metabolism in buffalo calves fed on rations containing two levels of crude protein

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.; Lal, M.; Varma, A.; Ranjhan, S.K.

    1974-01-01

    Urea entry rates into the body pools of Murrah Buffalo calves have been estimated using a single injection isotope dilution technique using 14 C-urea. The animals were fed two levels of crude proteins, namely, 13 percent lower and 19 percent higher than N.R.C. recommendations. Results show that the recycling of urea is significantly better in animals given low crude protein contents. (M.G.B.)

  15. FAST COMMUNICATION: A PDE Based Two Level Model of the Masking Property of the Human Ear

    OpenAIRE

    Xin, Jack; Qi, Yingyong

    2003-01-01

    Human ear has the masking property that certain audible sound becomes inaudible in the presence of another sound. Masking is quantified by the raised threshold from the absolute hearing threshold in quiet. It is of scientific and practical importance to compute masking thresholds. Empirical models on masking have applications in low bit rate digital music compression. A first principle based two level model is developed with partial differential equation (PDE) at the periphe...

  16. The off-resonant aspects of decoherence and a critique of the two-level approximation

    International Nuclear Information System (INIS)

    Savran, Kerim; Hakioglu, T; Mese, E; Sevincli, Haldun

    2006-01-01

    Conditions in favour of a realistic multilevelled description of a decohering quantum system are examined. In this regard the first crucial observation is that the thermal effects, contrary to the conventional belief, play a minor role at low temperatures in the decoherence properties. The system-environment coupling and the environmental energy spectrum dominantly affect the decoherence. In particular, zero temperature quantum fluctuations or non-equilibrium sources can be present and influential on the decoherence rates in a wide energy range allowed by the spectrum of the environment. A crucial observation against the validity of the two-level approximation is that the decoherence rates are found to be dominated not by the long time resonant but the short time off-resonant processes. This observation is demonstrated in two stages. Firstly, our zero temperature numerical results reveal that the calculated short time decoherence rates are Gaussian-like (the time dependence of the density matrix is led by the second time derivative at t = 0). Exact analytical results are also permitted in the short time limit, which, consistent with our numerical results, reveal that this specific Gaussian-like behaviour is a property of the non-Markovian correlations in the environment. These Gaussian-like rates have no dependence on any spectral parameter (position and the width of the spectrum) except, in totality, the spectral area itself. The dependence on the spectral area is a power law. Furthermore, the Gaussian-like character at short times is independent of the number of levels (N), but the numerical value of the decoherence rates is a monotonic function of N. In this context, we demonstrate that leakage, as a characteristic multilevel effect, is dominated by the non-resonant processes. The long time behaviour of decoherence is also examined. Since our spectral model allows Markovian environmental correlations at long times, the decoherence rates in this regime become

  17. Automated urinalysis: first experiences and a comparison between the Iris iQ200 urine microscopy system, the Sysmex UF-100 flow cytometer and manual microscopic particle counting

    OpenAIRE

    Shayanfar, Noushin; Tobler, Ulrich; von Eckardstein, Arnold; Bestmann, Lukas

    2007-01-01

    Background: Automated analysis of insoluble urine components can reduce the workload of conventional microscopic examination of urine sediment and is possibly helpful for standardization. We compared the diagnostic performance of two automated urine sediment analyzers and combined dipstick/automated urine analysis with that of the traditional dipstick/microscopy algorithm. Methods: A total of 332 specimens were collected and analyzed for insoluble urine components by microscopy and automated ...

  18. Microscopic observation of bulking sludge formation and measures to fight it in activated sludge systems; Mikroskopische Betrachtung der Blaehschlammbildung und Massnahmen zur Bekaempfung in Belebungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Heine, W.; Sekoulov, I.; Burkhardt, H.; Behrendt, J. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

    1999-07-01

    The available results clearly show the suitability of digital microscopic image analysis for early detection of threatening bulking sludge events. Recognizing imminent bulking sludge events early on permits countering them effectively with simple and unspecific means. (orig.) [German] Die bisher erzielten Ergebnisse zeigen deutlich die Eignung der digitalen mikroskopischen Bildanalyse zur Frueherkennung drohender Blaehschlammereignisse. Wird ein drohendes Blaehschlammereignis fruehzeitig erkannt, so ist eine effektive Blaehschlammbekaempfung mit einfachen und unspezifischen Massnahmen moeglich. (orig.)

  19. Two-Level Micro-to-Nanoscale Hierarchical TiO2 Nanolayers on Titanium Surface

    Directory of Open Access Journals (Sweden)

    Elena G. Zemtsova

    2016-12-01

    Full Text Available Joint replacement is being actively developed within modern orthopedics. One novel material providing fast implantation is bioactive coatings. The synthesis of targeted nanocoatings on metallic nanotitanium surface is reported in this paper. TiO2-based micro- and nanocoatings were produced by sol-gel synthesis using dip-coating technology with subsequent fast (shock drying in hot plate mode at 400 °C. As a result of shock drying, the two-level hierarchical TiO2 nanolayer on the nanotitanium was obtained. This two-level hierarchy includes nanorelief of porous xerogel and microrelief of the micron-sized “defect” network (a crack network. The thickness of TiO2 nanolayers was controlled by repeating dip-coating process the necessary number of times after the first layer deposition. The state of the MS3T3-E1 osteoblast cell line (young cells that form bone tissue on the two-level hierarchical surface has been studied. Particularly, adhesion character, adhesion time and morphology have been studied. The reported results may serve the starting point for the development of novel bioactive coatings for bone and teeth implants.

  20. Femtosecond photoelectron point projection microscope

    International Nuclear Information System (INIS)

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-01-01

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect

  1. Transmission electron microscope CCD camera

    Science.gov (United States)

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  2. Optical modeling of Fresnel zoneplate microscopes

    International Nuclear Information System (INIS)

    Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

    2011-01-01

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.

  3. Microscopic polyangeitis, report of a case

    International Nuclear Information System (INIS)

    Malagon, Patricia; Suarez, Martha Lucia

    1998-01-01

    Polyarteritis or microscopic polyangeitis is a systemic necrotizing vasculitis associated with the lung-kidney syndrome. It presents with diffuse alveolar hemorrhage and necrotizing glomerulonephritis with multisystem involvement. A case is presented of a 50 years old male with its clinical and imaging findings

  4. Microscopic approaches to quantum nonequilibriumthermodynamics and information

    Science.gov (United States)

    2018-02-09

    perspective on quantum thermalization for Science [8]. Wrote a joint experiment- theory paper on studying connections between quantum and classical chaos in...on the random matrix theory (eigenstate thermalization) and macroscopic phenomena (both equilibrium and non-equilibrium). Understanding thermodynamics...information. Specific questions to be addressed: connections of microscopic description of quantum chaotic systems based on the random matrix theory

  5. Photon scanning tunneling microscope in combination with a force microscope

    NARCIS (Netherlands)

    Moers, M.H.P.; Moers, M.H.P.; Tack, R.G.; van Hulst, N.F.; Bölger, B.; Bölger, B.

    1994-01-01

    The simultaneous operation of a photon scanning tunneling microscope with an atomic force microscope is presented. The use of standard atomic force silicon nitride cantilevers as near-field optical probes offers the possibility to combine the two methods. Vertical forces and torsion are detected

  6. Evaluation of a completely robotized neurosurgical operating microscope.

    Science.gov (United States)

    Kantelhardt, Sven R; Finke, Markus; Schweikard, Achim; Giese, Alf

    2013-01-01

    Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

  7. Use of optical microscopes in research work in the field of work safety in mines

    Energy Technology Data Exchange (ETDEWEB)

    Piskorska-Kalisz, Z

    1979-05-01

    Notes that coal dust in mine air is measured by means of optical microscopes. The microscope is part of a dust counter called a konimeter. With the help of optical microscopes dust particles in a sample are counted. The Cawood-Patterson network is inserted in the eyepiece of a microscope. At present konimeters produced by Zeiss Works are used in Poland. In predicting rock burst hazard microscopes (light reflecting system) are used, e.g. Zeiss microscope Ng. With its help microcracks in coal samples are counted. An optical stereoscopic microscope is used for calculating the range of flames during coal dust explosions.

  8. A microscope for Fermi gases

    International Nuclear Information System (INIS)

    Omran, Ahmed

    2016-01-01

    This thesis reports on a novel quantum gas microscope to investigate many-body systems of fermionic atoms in optical lattices. Single-site resolved imaging of ultracold lattice gases has enabled powerful studies of bosonic quantum many-body systems. The extension of this capability to Fermi gases offers new prospects to studying complex phenomena of strongly correlated systems, for which numerical simulations are often out of reach. Using standard techniques of laser cooling, optical trapping, and evaporative cooling, ultracold Fermi gases of 6 Li are prepared and loaded into a large-scale 2D optical lattice of flexible geometry. The atomic distribution is frozen using a second, short-scaled lattice, where we perform Raman sideband cooling to induce fluorescence on each atom while maintaining its position. Together with high-resolution imaging, the fluorescence signals allow for reconstructing the initial atom distribution with single-site sensitivity and high fidelity. Magnetically driven evaporative cooling in the plane allows for producing degenerate Fermi gases with almost unity filling in the initial lattice, allowing for the first microscopic studies of ultracold gases with clear signatures of Fermi statistics. By preparing an ensemble of spin-polarised Fermi gases, we detect a flattening of the density profile towards the centre of the cloud, which is a characteristic of a band-insulating state. In one set of experiments, we demonstrate that losses of atom pairs on a single lattice site due to light-assisted collisions are circumvented. The oversampling of the second lattice allows for deterministic separation of the atom pairs into different sites. Compressing a high-density sample in a trap before loading into the lattice leads to many double occupancies of atoms populating different bands, which we can image with no evidence for pairwise losses. We therefore gain direct access to the true number statistics on each lattice site. Using this feature, we can

  9. Scanning Quantum Cryogenic Atom Microscope

    Science.gov (United States)

    Yang, Fan; Kollár, Alicia J.; Taylor, Stephen F.; Turner, Richard W.; Lev, Benjamin L.

    2017-03-01

    Microscopic imaging of local magnetic fields provides a window into the organizing principles of complex and technologically relevant condensed-matter materials. However, a wide variety of intriguing strongly correlated and topologically nontrivial materials exhibit poorly understood phenomena outside the detection capability of state-of-the-art high-sensitivity high-resolution scanning probe magnetometers. We introduce a quantum-noise-limited scanning probe magnetometer that can operate from room-to-cryogenic temperatures with unprecedented dc-field sensitivity and micron-scale resolution. The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) employs a magnetically levitated atomic Bose-Einstein condensate (BEC), thereby providing immunity to conductive and blackbody radiative heating. The SQCRAMscope has a field sensitivity of 1.4 nT per resolution-limited point (approximately 2 μ m ) or 6 nT /√{Hz } per point at its duty cycle. Compared to point-by-point sensors, the long length of the BEC provides a naturally parallel measurement, allowing one to measure nearly 100 points with an effective field sensitivity of 600 pT /√{Hz } for each point during the same time as a point-by-point scanner measures these points sequentially. Moreover, it has a noise floor of 300 pT and provides nearly 2 orders of magnitude improvement in magnetic flux sensitivity (down to 10-6 Φ0/√{Hz } ) over previous atomic probe magnetometers capable of scanning near samples. These capabilities are carefully benchmarked by imaging magnetic fields arising from microfabricated wire patterns in a system where samples may be scanned, cryogenically cooled, and easily exchanged. We anticipate the SQCRAMscope will provide charge-transport images at temperatures from room temperature to 4 K in unconventional superconductors and topologically nontrivial materials.

  10. Microscopic studies of RIB target materials and ion induced nanostructures

    International Nuclear Information System (INIS)

    Karmakar, Prasanta; Bhattacharya, Shampa; Roy, Tapatee Kundu; Bhowmick, Debasis; Chakrabarti, Alok

    2010-01-01

    The invention of electron microscope and scanning probe microscope has empowered us to visualize the tiny world that has explored many fundamental laws of natures. Further technological advancements have made these tools capable to probe micron size structures to individual atom. These microscopes are used to image and study micron size fibers or grain structures used for high yield radioactive products, to few nanometer size ripple, dot and hole structures produced by ion irradiation. Electron Microscope has also been used to characterize the ion beam synthesized dilute magnetic systems

  11. Characteristics of the 2011 Tohoku Tsunami and introduction of two level tsunamis for tsunami disaster mitigation.

    Science.gov (United States)

    Sato, Shinji

    2015-01-01

    Characteristics of the 2011 Tohoku Tsunami have been revealed by collaborative tsunami surveys extensively performed under the coordination of the Joint Tsunami Survey Group. The complex behaviors of the mega-tsunami were characterized by the unprecedented scale and the low occurrence frequency. The limitation and the performance of tsunami countermeasures were described on the basis of tsunami surveys, laboratory experiments and numerical analyses. These findings contributed to the introduction of two-level tsunami hazards to establish a new strategy for tsunami disaster mitigation, combining structure-based flood protection designed by the Level-1 tsunami and non-structure-based damage reduction planned by the Level-2 tsunami.

  12. Teleporting the one-qubit state via two-level atoms with spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

    2011-05-14

    We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

  13. A January angular momentum balance in the OSU two-level atmospheric general circulation model

    Science.gov (United States)

    Kim, J.-W.; Grady, W.

    1982-01-01

    The present investigation is concerned with an analysis of the atmospheric angular momentum balance, based on the simulation data of the Oregon State University two-level atmospheric general circulation model (AGCM). An attempt is also made to gain an understanding of the involved processes. Preliminary results on the angular momentum and mass balance in the AGCM are shown. The basic equations are examined, and questions of turbulent momentum transfer are investigated. The methods of analysis are discussed, taking into account time-averaged balance equations, time and longitude-averaged balance equations, mean meridional circulation, the mean meridional balance of relative angular momentum, and standing and transient components of motion.

  14. Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier

    International Nuclear Information System (INIS)

    Oh, Seongshik; Cicak, Katarina; Kline, Jeffrey S.; Sillanpaeae, Mika A.; Osborn, Kevin D.; Whittaker, Jed D.; Simmonds, Raymond W.; Pappas, David P.

    2006-01-01

    Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits (qubits) using a single-crystal Al 2 O 3 tunnel barrier. We have found an ∼80% reduction in the density of the spectral splittings that indicate the existence of two-level fluctators (TLFs) in amorphous tunnel barriers. The residual ∼20% TLFs can be attributed to interfacial effects that may be further reduced by different electrode materials. These results show that decoherence sources in the tunnel barrier of Josephson qubits can be identified and eliminated

  15. Geometric manipulation of the quantum states of two-level atoms

    International Nuclear Information System (INIS)

    Tian, Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Babbitt, Wm. Randall

    2004-01-01

    Manipulation of the quantum states of two-level atoms has been investigated using laser-controlled geometric phase change, which has the potential to build robust quantum logic gates for quantum computing. For a qubit based on two electronic transition levels of an atom, two basic quantum operations that can make any universal single qubit gate have been designed employing resonant laser pulses. An operation equivalent to a phase gate has been demonstrated using Tm 3+ doped in a yttrium aluminum garnet crystal

  16. Characterizing high-energy-formed particulates with the scanning electron microscope/energy dispersive spectrometer system. Progress report, March--September 1977

    International Nuclear Information System (INIS)

    Casey, A.W.; Biermann, A.H.

    1977-01-01

    A method is being sought that will allow the differentiation between particulates formed in implosions and particulates formed in explosions. The scanning electron microscope (SEM) and energy dispersive x-ray analysis (EDS) were used to measure and compare particle size, shape, surface morphology, and composition. Implosion and explosion detonations yielded spherical, smooth particles within the same size range. Although the particle size, shape, and morphology were the same for comparable samples of different detonation type, there were distinct differences in composition. It is not certain whether differences in composition reflect differences in device components or differences in the nature of the detonation

  17. Loschmidt echo of a two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field

    International Nuclear Information System (INIS)

    Zhong Ming; Tong Peiqing

    2011-01-01

    The Loschmidt echo (LE) of a central two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field is studied. A general formula for LE is derived, which we use to discuss the influence of the criticality of the environment on LE. It is found that for the periodic XY chain the behaviors of LE in the vicinity of the critical points are similar to those of the uniform case. It is different for the disordered transverse Ising chains. For the aperiodic chains, if the surrounding systems are bounded chains, the behaviors of LE are similar to those of the uniform case, while if the surrounding systems are unbounded chains, they are similar to those of the disordered case.

  18. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...

  19. An Economic Order Quantity Model with Completely Backordering and Nondecreasing Demand under Two-Level Trade Credit

    Directory of Open Access Journals (Sweden)

    Zohreh Molamohamadi

    2014-01-01

    Full Text Available In the traditional inventory system, it was implicitly assumed that the buyer pays to the seller as soon as he receives the items. In today’s competitive industry, however, the seller usually offers the buyer a delay period to settle the account of the goods. Not only the seller but also the buyer may apply trade credit as a strategic tool to stimulate his customers’ demands. This paper investigates the effects of the latter policy, two-level trade credit, on a retailer’s optimal ordering decisions within the economic order quantity framework and allowable shortages. Unlike most of the previous studies, the demand function of the customers is considered to increase with time. The objective of the retailer’s inventory model is to maximize the profit. The replenishment decisions optimally are obtained using genetic algorithm. Two special cases of the proposed model are discussed and the impacts of parameters on the decision variables are finally investigated. Numerical examples demonstrate the profitability of the developed two-level supply chain with backorder.

  20. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  1. A high resolution ion microscope for cold atoms

    International Nuclear Information System (INIS)

    Stecker, Markus; Schefzyk, Hannah; Fortágh, József; Günther, Andreas

    2017-01-01

    We report on an ion-optical system that serves as a microscope for ultracold ground state and Rydberg atoms. The system is designed to achieve a magnification of up to 1000 and a spatial resolution in the 100 nm range, thereby surpassing many standard imaging techniques for cold atoms. The microscope consists of four electrostatic lenses and a microchannel plate in conjunction with a delay line detector in order to achieve single particle sensitivity with high temporal and spatial resolution. We describe the design process of the microscope including ion-optical simulations of the imaging system and characterize aberrations and the resolution limit. Furthermore, we present the experimental realization of the microscope in a cold atom setup and investigate its performance by patterned ionization with a structure size down to 2.7 μ m. The microscope meets the requirements for studying various many-body effects, ranging from correlations in cold quantum gases up to Rydberg molecule formation. (paper)

  2. SCREENING OF MEDIUM COMPOUNDS USING A TWO-LEVEL FACTORIAL DESIGN FOR SACCHAROMYCES BOULARDII

    Directory of Open Access Journals (Sweden)

    GUOWEI SHU

    2016-04-01

    Full Text Available Even if the probiotic effect of Saccharomyces boulardii is has been reported, this yeast is rarely used in medium composition. Based on single factor experiment, two-level factorial design was employed to evaluate the effect of carbon sources (sucrose, glucose, nitrogen sources (soy peptone, beef extract, yeast extract, calf serum, malt extract and salts (K2HPO4, KH2PO4, MgSO4, Na2HPO4, NaH2PO4, CaCl2, sodium citrate, sodium glutamate on the growth of S. boulardii. At the same time, the optical density (OD in the medium was measured at 560 nm after 36 h of incubation. The result of two-level factorial design experiment showed that calf serum (p = 0.0214 and sodium citrate (p = 0.0045 are the significant growth factors of S. boulardii, sucrose (p = 0.0861 and malt extract (p = 0.0763 are important factors. In addition, sucrose and sodium citrate showed positive effect on the growth of S. boulardii. However, calf serum and malt extract showed negative effect on the growth. And we determined that the optimum medium composition for S. boulardii was as follow: 37.5 g·L-1 sucrose, 6 g·L-1 calf serum, 6 g·L-1 malt extract, 5 g·L-1 sodium citrate.

  3. Improved Genetic Algorithm with Two-Level Approximation for Truss Optimization by Using Discrete Shape Variables

    Directory of Open Access Journals (Sweden)

    Shen-yan Chen

    2015-01-01

    Full Text Available This paper presents an Improved Genetic Algorithm with Two-Level Approximation (IGATA to minimize truss weight by simultaneously optimizing size, shape, and topology variables. On the basis of a previously presented truss sizing/topology optimization method based on two-level approximation and genetic algorithm (GA, a new method for adding shape variables is presented, in which the nodal positions are corresponding to a set of coordinate lists. A uniform optimization model including size/shape/topology variables is established. First, a first-level approximate problem is constructed to transform the original implicit problem to an explicit problem. To solve this explicit problem which involves size/shape/topology variables, GA is used to optimize individuals which include discrete topology variables and shape variables. When calculating the fitness value of each member in the current generation, a second-level approximation method is used to optimize the continuous size variables. With the introduction of shape variables, the original optimization algorithm was improved in individual coding strategy as well as GA execution techniques. Meanwhile, the update strategy of the first-level approximation problem was also improved. The results of numerical examples show that the proposed method is effective in dealing with the three kinds of design variables simultaneously, and the required computational cost for structural analysis is quite small.

  4. Two-level method for unsteady Navier-Stokes equations based on a new projection

    International Nuclear Information System (INIS)

    Hou Yanren; Li Kaitai

    2004-12-01

    A two-level algorithm for the two dimensional unsteady Navier-Stokes equations based on a new projection is proposed and investigated. The approximate solution is solved as a sum of a large eddy component and a small eddy component, which are in the sense of the new projection, constructed in this paper. These two terms advance in time explicitly. Actually, the new algorithm proposed here can be regarded as a sort of postprocessing algorithm for the standard Galerkin method (SGM). The large eddy part is solved by SGM in the usual L 2 -based large eddy subspace while the small eddy part (the correction part) is obtained in its complement subspace in the sense of the new projection. The stability analysis indicates the improvement of the stability comparing with SGM of the same scale, and the L 2 -error estimate shows that the scheme can improve the accuracy of SGM approximation for half order. We also propose a numerical implementation based on Lagrange multiplier for this two-level algorithm. (author)

  5. A Weighted Two-Level Bregman Method with Dictionary Updating for Nonconvex MR Image Reconstruction

    Directory of Open Access Journals (Sweden)

    Qiegen Liu

    2014-01-01

    Full Text Available Nonconvex optimization has shown that it needs substantially fewer measurements than l1 minimization for exact recovery under fixed transform/overcomplete dictionary. In this work, two efficient numerical algorithms which are unified by the method named weighted two-level Bregman method with dictionary updating (WTBMDU are proposed for solving lp optimization under the dictionary learning model and subjecting the fidelity to the partial measurements. By incorporating the iteratively reweighted norm into the two-level Bregman iteration method with dictionary updating scheme (TBMDU, the modified alternating direction method (ADM solves the model of pursuing the approximated lp-norm penalty efficiently. Specifically, the algorithms converge after a relatively small number of iterations, under the formulation of iteratively reweighted l1 and l2 minimization. Experimental results on MR image simulations and real MR data, under a variety of sampling trajectories and acceleration factors, consistently demonstrate that the proposed method can efficiently reconstruct MR images from highly undersampled k-space data and presents advantages over the current state-of-the-art reconstruction approaches, in terms of higher PSNR and lower HFEN values.

  6. A novel two-level dynamic parallel data scheme for large 3-D SN calculations

    International Nuclear Information System (INIS)

    Sjoden, G.E.; Shedlock, D.; Haghighat, A.; Yi, C.

    2005-01-01

    We introduce a new dynamic parallel memory optimization scheme for executing large scale 3-D discrete ordinates (Sn) simulations on distributed memory parallel computers. In order for parallel transport codes to be truly scalable, they must use parallel data storage, where only the variables that are locally computed are locally stored. Even with parallel data storage for the angular variables, cumulative storage requirements for large discrete ordinates calculations can be prohibitive. To address this problem, Memory Tuning has been implemented into the PENTRAN 3-D parallel discrete ordinates code as an optimized, two-level ('large' array, 'small' array) parallel data storage scheme. Memory Tuning can be described as the process of parallel data memory optimization. Memory Tuning dynamically minimizes the amount of required parallel data in allocated memory on each processor using a statistical sampling algorithm. This algorithm is based on the integral average and standard deviation of the number of fine meshes contained in each coarse mesh in the global problem. Because PENTRAN only stores the locally computed problem phase space, optimal two-level memory assignments can be unique on each node, depending upon the parallel decomposition used (hybrid combinations of angular, energy, or spatial). As demonstrated in the two large discrete ordinates models presented (a storage cask and an OECD MOX Benchmark), Memory Tuning can save a substantial amount of memory per parallel processor, allowing one to accomplish very large scale Sn computations. (authors)

  7. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproductive microscopes and microscope... Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a) Identification. Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are...

  8. Imaging differential polarization microscope with electronic readout

    International Nuclear Information System (INIS)

    Mickols, W.; Tinoco, I.; Katz, J.E.; Maestre, M.F.; Bustamante, C.

    1985-01-01

    A differential polarization microscope forms two images: one of the transmitted intensity and the other due to the change in intensity between images formed when different polarizations of light are used. The interpretation of these images for linear dichroism and circular dichroism are described. The design constraints on the data acquisition systems and the polarization modulation are described. The advantage of imaging several biological systems which contain optically anisotropic structures are described

  9. Digital management of an electron microscope unit

    International Nuclear Information System (INIS)

    Elea, N.; Dickson, M.; Munroe, P.

    2002-01-01

    Full text: Electron microscope units, especially those such as ours, which operate as a central infrastructural facility are increasingly asked to provide more service, over more instruments with decreasing, or limited, financial resources. We believe that staff time is best used performing electron microscopy, assisting users and maintaining instrumentation rather than in the pursuit of red tape. One solution to this problem has been the creation of a control system which performs all routine acts of data management, such as the archiving and accessing of digital data, providing access to bookings, and most importantly in the era of user pays services, logging time and billing users. The system we have created, developed and expanded allows the users themselves to access our server through any web-browser and make their own bookings or access and manipulate their data. Users themselves must log on to a microscope through swipecard readers before it can be used and log-off after use. Their time is logged precisely and an exquisitely fair user pays systems can be operated by transferring logged usage time to spreadsheets to calculate charges. Furthermore, this system acts as a method of user authentication and can be used to bar incompetent or unauthorised users. The system has recently been upgraded to increase its utility to include sensors that monitor the electron microscope operating environment, such as magnetic field, room temperature, water flow etc, so that if these parameters depart significantly from optimum levels electron microscope unit staff may be alerted. In this presentation the structure of our system will be described and the advantages and disadvantages of such a system will be discussed. Copyright (2002) Australian Society for Electron Microscopy Inc

  10. Computer simulation of two-level pedicle subtraction osteotomy for severe thoracolumbar kyphosis in ankylosing spondylitis

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2017-01-01

    Full Text Available Background: Advanced ankylosing spondylitis is often associated with thoracolumbar kyphosis, resulting in an abnormal spinopelvic balance and pelvic morphology. Different osteotomy techniques have been used to correct AS deformities, unfortunnaly, not all AS patients can gain spinal sagittal balance and good horizontal vision after osteotomy. Materials and Methods: Fourteen consecutive AS patients with severe thoracolumbar kyphosis who were treated with two-level PSO were studied retrospectively. All were male with a mean age of 34.9 ± 9.6 years. The followup ranged from 1–5 years. Preoperative computer simulations using the Surgimap Spinal software were performed for all patients, and the osteotomy level and angle determined from the computer simulation were used surgically. Spinal sagittal parameters were measured preoperatively, after the computer simulation, and postoperatively and included thoracic kyphosis (TK, lumbar lordosis (LL, sagittal vertical axis (SVA, pelvic incidence, pelvic tilt (PT, and sacral slope (SS. The level of correlation between the computer simulation and postoperative parameters was evaluated, and the differences between preoperative and postoperative parameters were compared. The visual analog scale (VAS for back pain and clinical outcome was also assessed. Results: Six cases underwent PSO at L1 and L3, five cases at L2 and T12, and three cases at L3 and T12. TK was corrected from 57.8 ± 15.2° preoperatively to 45.3 ± 7.7° postoperatively (P < 0.05, LL from 9.3 ± 17.5° to −52.3 ± 3.9° (P < 0.001, SVA from 154.5 ± 36.7 to 37.8 ± 8.4 mm (P < 0.001, PT from 43.3 ± 6.1° to 18.0 ± 0.9° (P < 0.001, and SS from 0.8 ± 7.0° to 26.5 ± 10.6° (P < 0.001. The LL, VAS, and PT of the simulated two-level PSO were highly consistent with, or almost the same as, the postoperative parameters. The correlations between the computer simulations and postoperative parameters were significant. The VAS decreased

  11. A compact scanning soft X-ray microscope

    International Nuclear Information System (INIS)

    Trail, J.A.

    1989-01-01

    Soft x-ray microscopes operating at wavelengths between 2.3 nm and 4.4 nm are capable of imaging wet biological cells with a resolution many times that of a visible light microscope. Several such soft x-ray microscopes have been constructed. However, with the exception of contact microscopes, all use synchrotrons as the source of soft x-ray radiation and Fresnel zone plates as the focusing optics. These synchrotron based microscopes are very successful but have the disadvantage of limited access. This dissertation reviews the construction and performance of a compact scanning soft x-ray microscope whose size and accessibility is comparable to that of an electron microscope. The microscope uses a high-brightness laser-produced plasma as the soft x-ray source and normal incidence multilayer-coated mirrors in a Schwarzschild configuration as the focusing optics. The microscope operates at a wavelength of 14 nm, has a spatial resolution of 0.5 μm, and has a soft x-ray photon flux through the focus of 10 4 -10 5 s -1 when operated with only 170 mW of average laser power. The complete system, including the laser, fits on a single 4' x 8' optical table. The significant components of the compact microscope are the laser-produced plasma (LPP) source, the multilayer coatings, and the Schwarzschild objective. These components are reviewed, both with regard to their particular use in the current microscope and with regard to extending the microscope performance to higher resolution, higher speed, and operation at shorter wavelengths. Measurements of soft x-ray emission and debris emission from our present LPP source are presented and considerations given for an optimal LPP source. The LPP source was also used as a broadband soft x-ray source for measurement of normal incidence multilayer mirror reflectance in the 10-25 nm spectral region

  12. The head-mounted microscope.

    Science.gov (United States)

    Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

    2012-04-01

    Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  13. Atomic force microscope with integrated optical microscope for biological applications

    OpenAIRE

    Putman, Constant A.J.; Putman, C.A.J.; van der Werf, Kees; de Grooth, B.G.; van Hulst, N.F.; Segerink, Franciscus B.; Greve, Jan

    1992-01-01

    Since atomic force microscopy (AFM) is capable of imaging nonconducting surfaces, the technique holds great promises for high‐resolution imaging of biological specimens. A disadvantage of most AFMs is the fact that the relatively large sample surface has to be scanned multiple times to pinpoint a specific biological object of interest. Here an AFM is presented which has an incorporated inverted optical microscope. The optical image from the optical microscope is not obscured by the cantilever...

  14. Propagation of an attosecond pulse in a dense two-level medium

    International Nuclear Information System (INIS)

    Song Xiaohong; Gong Shangqing; Yang Weifeng; Xu Zhizhan

    2004-01-01

    We investigate the propagation of attosecond pulse in a dense two-level medium by using an iterative predictor-corrector finite-difference time-domain method. We find when attosecond pulse is considered, that the standard area theorem will break down even for small area pulses: ideal self-induced transparency cannot occur even for a 2π pulse, while the pulses whose areas are not integer multiples of 2π, such as 1.8π and 2.2π pulses, cannot evolve to 2π pulses as predicted by the standard area theorem. Significantly higher spectra components can occur on all these small area propagating pulses due to strong carrier reshaping. Furthermore, these higher spectral components dependent sensitively on the pulse area: the larger the pulse area is, the more evident are these higher spectral components

  15. Estimation of Missing Observations in Two-Level Split-Plot Designs

    DEFF Research Database (Denmark)

    Almimi, Ashraf A.; Kulahci, Murat; Montgomery, Douglas C.

    2008-01-01

    Inserting estimates for the missing observations from split-plot designs restores their balanced or orthogonal structure and alleviates the difficulties in the statistical analysis. In this article, we extend a method due to Draper and Stoneman to estimate the missing observations from unreplicated...... two-level factorial and fractional factorial split-plot (FSP and FFSP) designs. The missing observations, which can either be from the same whole plot, from different whole plots, or comprise entire whole plots, are estimated by equating to zero a number of specific contrast columns equal...... to the number of the missing observations. These estimates are inserted into the design table and the estimates for the remaining effects (or alias chains of effects as the case with FFSP designs) are plotted on two half-normal plots: one for the whole-plot effects and the other for the subplot effects...

  16. Thermal analysis of multi-MW two-level wind power converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Mogens, Lau

    2012-01-01

    In this paper, the multi-MW wind turbine of partial-scale and full-scale two-level power converter with DFIG and direct-drive PMSG are designed and compared in terms of their thermal performance. Simulations of different configurations regarding loss distribution and junction temperature...... in the power device in the whole range of wind speed are presented and analyzed. It is concluded that in both partial-scale and full-scale power converter the most thermal stressed power device in the generator-side converter will have higher mean junction temperature and larger junction temperature...... fluctuation compared to grid-side converter at the rated wind speed. Moreover, the thermal performance of the generator-side converter in the partial-scale power converter becomes crucial around the synchronous operating point and should be considered carefully....

  17. Two-Level Verification of Data Integrity for Data Storage in Cloud Computing

    Science.gov (United States)

    Xu, Guangwei; Chen, Chunlin; Wang, Hongya; Zang, Zhuping; Pang, Mugen; Jiang, Ping

    Data storage in cloud computing can save capital expenditure and relive burden of storage management for users. As the lose or corruption of files stored may happen, many researchers focus on the verification of data integrity. However, massive users often bring large numbers of verifying tasks for the auditor. Moreover, users also need to pay extra fee for these verifying tasks beyond storage fee. Therefore, we propose a two-level verification of data integrity to alleviate these problems. The key idea is to routinely verify the data integrity by users and arbitrate the challenge between the user and cloud provider by the auditor according to the MACs and ϕ values. The extensive performance simulations show that the proposed scheme obviously decreases auditor's verifying tasks and the ratio of wrong arbitration.

  18. TWO-LEVEL HIERARCHICAL COORDINATION QUEUING METHOD FOR TELECOMMUNICATION NETWORK NODES

    Directory of Open Access Journals (Sweden)

    M. V. Semenyaka

    2014-07-01

    Full Text Available The paper presents hierarchical coordination queuing method. Within the proposed method a queuing problem has been reduced to optimization problem solving that was presented as two-level hierarchical structure. The required distribution of flows and bandwidth allocation was calculated at the first level independently for each macro-queue; at the second level solutions obtained on lower level for each queue were coordinated in order to prevent probable network link overload. The method of goal coordination has been determined for multilevel structure managing, which makes it possible to define the order for consideration of queue cooperation restrictions and calculation tasks distribution between levels of hierarchy. Decisions coordination was performed by the method of Lagrange multipliers. The study of method convergence has been carried out by analytical modeling.

  19. Intensity profiles of superdeformed bands in Pb isotopes in a two-level mixing model

    International Nuclear Information System (INIS)

    Wilson, A. N.; Szigeti, S. S.; Rogers, J. I.; Davidson, P. M.; Cardamone, D. M.

    2009-01-01

    A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in 192 Pb, 194 Pb, and 196 Pb. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of γ decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed

  20. Photon echo with a few photons in two-level atoms

    International Nuclear Information System (INIS)

    Bonarota, M; Dajczgewand, J; Louchet-Chauvet, A; Le Gouët, J-L; Chanelière, T

    2014-01-01

    To store and retrieve signals at the single photon level, various photon echo schemes have resorted to complex preparation steps involving ancillary shelving states in multi-level atoms. For the first time, we experimentally demonstrate photon echo operation at such a low signal intensity without any preparation step, which allows us to work with mere two-level atoms. This simplified approach relies on the so-coined ‘revival of silenced echo’ (ROSE) scheme. Low noise conditions are obtained by returning the atoms to the ground state before the echo emission. In the present paper we manage ROSE in photon counting conditions, showing that very strong control fields can be compatible with extremely weak signals, making ROSE consistent with quantum memory requirements. (paper)

  1. The deuteron microscopic optical potential

    International Nuclear Information System (INIS)

    Lu Congshan; Zhang Jingshang; Shen Qingbiao

    1991-01-01

    The two particle Green's function is introduced. When the direct interaction between two nucleons is neglected, the first and second order mass operators of two particles are the sum of those for each particle. The nucleon microscopic optical potential is calculated by applying nuclear matter approximation and effective Skyrme interaction. Then the deuteron microscopic optical potential (DMOP) is calculated by using fold formula. For improvement of the theory, the two particle polarization diagram contribution to the imaginary part of the deuteron microscopic optical potential is studied

  2. Indoor Semantic Modelling for Routing: The Two-Level Routing Approach for Indoor Navigation

    Directory of Open Access Journals (Sweden)

    Liu Liu

    2017-11-01

    Full Text Available Humans perform many activities indoors and they show a growing need for indoor navigation, especially in unfamiliar buildings such as airports, museums and hospitals. Complexity of such buildings poses many challenges for building managers and visitors. Indoor navigation services play an important role in supporting these indoor activities. Indoor navigation covers extensive topics such as: 1 indoor positioning and localization; 2 indoor space representation for navigation model generation; 3 indoor routing computation; 4 human wayfinding behaviours; and 5 indoor guidance (e.g., textual directories. So far, a large number of studies of pedestrian indoor navigation have presented diverse navigation models and routing algorithms/methods. However, the major challenge is rarely referred to: how to represent the complex indoor environment for pedestrians and conduct routing according to the different roles and sizes of users. Such complex buildings contain irregular shapes, large open spaces, complicated obstacles and different types of passages. A navigation model can be very complicated if the indoors are accurately represented. Although most research demonstrates feasible indoor navigation models and related routing methods in regular buildings, the focus is still on a general navigation model for pedestrians who are simplified as circles. In fact, pedestrians represent different sizes, motion abilities and preferences (e.g., described in user profiles, which should be reflected in navigation models and be considered for indoor routing (e.g., relevant Spaces of Interest and Points of Interest. In order to address this challenge, this thesis proposes an innovative indoor modelling and routing approach – two-level routing. It specially targets the case of routing in complex buildings for distinct users. The conceptual (first level uses general free indoor spaces: this is represented by the logical network whose nodes represent the spaces and edges

  3. Inverse problem for a two-level medium with an inhomgeneously broadened transition in the field of a periodic wave

    International Nuclear Information System (INIS)

    Zabolotskii, A.A.

    1995-01-01

    The inverse problem is considered for a spectral problem, which is formally equivalent to a system of Bloch equations for an inhomogeneously broadened transition interacting with the electric field. Two cases are considered to demonstrate that, for any given frequency interval, one can determine the pulse of the shape which corresponds to the interaction with only this frequency interval. In the general case, the pulse shape is described by a nonlinear periodic wave. The first example is the resonance interaction of light with a gas of two-level atoms. The second example is interaction of a linearly polarized light with the molecular J-J transition, where J much-gt 1. In the latter case, the role of inhomogeneous broadening belongs to the frequency shift induced by the applied magnetic field. 10 refs

  4. Cascaded two-photon nonlinearity in a one-dimensional waveguide with multiple two-level emitters

    Science.gov (United States)

    Roy, Dibyendu

    2013-01-01

    We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation). PMID:23948782

  5. Dynamics of a trapped two-level and three-level atom interacting with classical electromagnetic field

    International Nuclear Information System (INIS)

    Ray, Aditi

    2004-01-01

    The dynamics of a two-level atom driven by a single laser beam and three-level atom (Lambda configuration) irradiated by two laser beams are studied taking into account of the quantized center-of-mass motion of the atom. It is shown that the trapped atom system under appropriate resonance condition exhibits the large time-scale revivals when the index of the vibrational sideband responsible for the atomic electronic transition is greater than unity. The revival times are shown to be dependent on the initial number of vibrational excitations and the magnitude of the Lamb-Dicke parameter. The sub-Poissonian statistics in vibrational quantum number is observed at certain time intervals. The minimum time of interaction for which the squeezed states of motional quadrature are generated is found to be decreasing with the increase in the Lamb-Dicke parameter

  6. The EPQ model under conditions of two levels of trade credit and limited storage capacity in supply chain management

    Science.gov (United States)

    Chung, Kun-Jen

    2013-09-01

    An inventory problem involves a lot of factors influencing inventory decisions. To understand it, the traditional economic production quantity (EPQ) model plays rather important role for inventory analysis. Although the traditional EPQ models are still widely used in industry, practitioners frequently question validities of assumptions of these models such that their use encounters challenges and difficulties. So, this article tries to present a new inventory model by considering two levels of trade credit, finite replenishment rate and limited storage capacity together to relax the basic assumptions of the traditional EPQ model to improve the environment of the use of it. Keeping in mind cost-minimisation strategy, four easy-to-use theorems are developed to characterise the optimal solution. Finally, the sensitivity analyses are executed to investigate the effects of the various parameters on ordering policies and the annual total relevant costs of the inventory system.

  7. Analysis of dicentrics in human lymphocytes exposed to ionizing radiation using the automated system and optical microscope; Analisis de dicentricos en linfocitos humanos expuestos a radiacion ionizante mediante el sistema automatizado y microscopio optico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez A, J.

    2016-07-01

    Ionizing radiation is a form of energy that produces ionizations in the molecules it traverses. When the higher energy radiation interacts with the structure of human chromosomes, chromosome aberrations, mainly of the dicentric type, are the union of two damaged chromosomes, represented by two centromeres and non centromere fragment. There are situations where a population of people may be affected by the release of any radioactive material and it is impossible to determine in a short time the absorbed dose to which each person was exposed. The dicentrics analysis from the culture of human lymphocytes is used to estimate doses of exposure to ionizing radiation, using the optical microscope. The objective of this work is to analyze dicentric chromosomal lesions, using the optical microscope in comparison with the semi-automated system, to respond promptly to radiological emergencies. For this study, two samples irradiated with {sup 60}Co were analyzed, one in the Instituto Nacional de Investigaciones Nucleares (ININ) reaching doses of 2.7 ± 0.1 and 0.85 ± 0.1 Gy, and the other in Walischmiller Engineering G mb H, Markdorf (Germany) reaching doses of 0.84 ± 0.3 and 2.8 ± 0.1 Gy. A lymphocyte culture was performed following the recommendations of the IAEA, using minimum essential MEM medium previously prepared with BrdU, sodium heparin, antibiotic and L-glutamine. Phytohemagglutinin, fetal calf serum was added to the sample, incubated at 37 degrees Celsius for 48 hours and three hours before the end of incubation, colcemide was placed. KCl post-culture was added and lamellae were prepared by washing with the 3:1 acid-acetic fixative solution and a Giemsa staining. 1000 cell readings were performed using the optical microscope and the automated system according to study protocols and quality standards to estimate absorbed dose by means of dicentric analysis, defined by ISO-19238. With the automated system similar results of absorbed dose were obtained with respect

  8. Automated urinalysis: first experiences and a comparison between the Iris iQ200 urine microscopy system, the Sysmex UF-100 flow cytometer and manual microscopic particle counting.

    Science.gov (United States)

    Shayanfar, Noushin; Tobler, Ulrich; von Eckardstein, Arnold; Bestmann, Lukas

    2007-01-01

    Automated analysis of insoluble urine components can reduce the workload of conventional microscopic examination of urine sediment and is possibly helpful for standardization. We compared the diagnostic performance of two automated urine sediment analyzers and combined dipstick/automated urine analysis with that of the traditional dipstick/microscopy algorithm. A total of 332 specimens were collected and analyzed for insoluble urine components by microscopy and automated analyzers, namely the Iris iQ200 (Iris Diagnostics) and the UF-100 flow cytometer (Sysmex). The coefficients of variation for day-to-day quality control of the iQ200 and UF-100 analyzers were 6.5% and 5.5%, respectively, for red blood cells. We reached accuracy ranging from 68% (bacteria) to 97% (yeast) for the iQ200 and from 42% (bacteria) to 93% (yeast) for the UF-100. The combination of dipstick and automated urine sediment analysis increased the sensitivity of screening to approximately 98%. We conclude that automated urine sediment analysis is sufficiently precise and improves the workflow in a routine laboratory. In addition, it allows sediment analysis of all urine samples and thereby helps to detect pathological samples that would have been missed in the conventional two-step procedure according to the European guidelines. Although it is not a substitute for microscopic sediment examination, it can, when combined with dipstick testing, reduce the number of specimens submitted to microscopy. Visual microscopy is still required for some samples, namely, dysmorphic erythrocytes, yeasts, Trichomonas, oval fat bodies, differentiation of casts and certain crystals.

  9. Remote Controlling and Monitoring of Microscopic Slides

    International Nuclear Information System (INIS)

    Mustafa, G.; Qadri, M.T.; Daraz, U.

    2016-01-01

    Remotely controlled microscopic slide was designed using especial Graphical User Interface (GUI) which interfaces the user at remote location with the real microscope using site and the user can easily view and control the slide present on the microscope's stage. Precise motors have been used to allow the movement in all the three dimensions required by a pathologist. The pathologist can easily access these slides from any remote location and so the physical presence of the pathologist is now made easy. This invention would increase the health care efficiency by reducing the time and cost of diagnosis, making it very easy to get the expert's opinion and supporting the pathologist to relocate himself for his work. The microscope is controlled with computer with an attractive Graphical User Interface (GUI), through which a pathologist can easily monitor, control and record the image of the slide. The pathologist can now do his work regardless of his location, time, cost and physically presence of lab equipment. The technology will help the specialist in viewing the patients slide from any location in the world. He would be able to monitor and control the stage. This will also help the pathological laboratories in getting opinion from senior pathologist who are present at any far location in the world. This system also reduces the life risks of the patients. (author)

  10. Microscopic Procedures for Plant Meiosis.

    Science.gov (United States)

    Braselton, James P.

    1997-01-01

    Describes laboratory techniques designed to familiarize students with meiosis and how microscopic preparations of meiosis are made. These techniques require the use of fresh or fixed flowers. Contains 18 references. (DDR)

  11. A fluorescence scanning electron microscope

    International Nuclear Information System (INIS)

    Kanemaru, Takaaki; Hirata, Kazuho; Takasu, Shin-ichi; Isobe, Shin-ichiro; Mizuki, Keiji; Mataka, Shuntaro; Nakamura, Kei-ichiro

    2009-01-01

    Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM) and an electron microscope (EM). In the current study, a scanning electron microscope (SEM) (JEOL JXA8600 M) was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM). In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

  12. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging.

    Science.gov (United States)

    Kiss, András; Smith, Donald F; Jungmann, Julia H; Heeren, Ron M A

    2013-12-30

    Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with polyatomic primary ion sources, are required to exploit the full potential of microscope mode mass spectrometry imaging, i.e. to efficiently push the limits of ultra-high spatial resolution, sample throughput and sensitivity. In this work, a C60 primary source was combined with a commercial mass microscope for microscope mode secondary ion mass spectrometry imaging. The detector setup is a pixelated detector from the Medipix/Timepix family with high-voltage post-acceleration capabilities. The system's mass spectral and imaging performance is tested with various benchmark samples and thin tissue sections. The high secondary ion yield (with respect to 'traditional' monatomic primary ion sources) of the C60 primary ion source and the increased sensitivity of the high voltage detector setup improve microscope mode secondary ion mass spectrometry imaging. The analysis time and the signal-to-noise ratio are improved compared with other microscope mode imaging systems, all at high spatial resolution. We have demonstrated the unique capabilities of a C60 ion microscope with a Timepix detector for high spatial resolution microscope mode secondary ion mass spectrometry imaging. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Microscopic modelling of doped manganites

    International Nuclear Information System (INIS)

    Weisse, Alexander; Fehske, Holger

    2004-01-01

    Colossal magneto-resistance manganites are characterized by a complex interplay of charge, spin, orbital and lattice degrees of freedom. Formulating microscopic models for these compounds aims at meeting two conflicting objectives: sufficient simplification without excessive restrictions on the phase space. We give a detailed introduction to the electronic structure of manganites and derive a microscopic model for their low-energy physics. Focusing on short-range electron-lattice and spin-orbital correlations we supplement the modelling with numerical simulations

  14. Microscopic approach to nuclear anharmonicities

    International Nuclear Information System (INIS)

    Matsuo, Masayuki; Shimizu, Yoshifumi; Matsuyanagi, Kenichi

    1985-01-01

    Present status of microscopic study of nuclear anharmonicity phenomena is reviewed from the viewpoint of the time-dependent Hartree-Bogoliubov approach. Both classical- and quantum-mechanical aspects of this approach are discussed. The Bohr-Mottelson-type collective Hamiltonian for anharmonic gamma vibrations is microscopically derived by means of the self-consistent-collective-coordinate method, and applied to the problem of two-phonon states of 168 Er. (orig.)

  15. Deuteron microscopic optical model potential

    International Nuclear Information System (INIS)

    Guo Hairui; Han Yinlu; Shen Qingbiao; Xu Yongli

    2010-01-01

    A deuteron microscopic optical model potential is obtained by the Green function method through nuclear-matter approximation and local-density approximation based on the effective Skyrme interaction. The microscopic optical model potential is used to calculate the deuteron reaction cross sections and the elastic scattering angular distributions for some target nuclei in the mass range 6≤A≤208 with incident deuteron energies up to 200 MeV. The calculated results are compared with the experimental data.

  16. Mice embryology: a microscopic overview.

    Science.gov (United States)

    Salvadori, Maria Letícia Baptista; Lessa, Thais Borges; Russo, Fabiele Baldino; Fernandes, Renata Avancini; Kfoury, José Roberto; Braga, Patricia Cristina Baleeiro Beltrão; Miglino, Maria Angélica

    2012-10-01

    In this work, we studied the embryology of mice of 12, 14, and 18 days of gestation by gross observation, light microscopy, and scanning electron microscopy. Grossly, the embryos of 12 days were observed in C-shaped region of the brain, eye pigmentation of the retina, first, second, and third pharyngeal arches gill pit nasal region on the fourth ventricle brain, cervical curvature, heart, liver, limb bud thoracic, spinal cord, tail, umbilical cord, and place of the mesonephric ridge. Microscopically, the liver, cardiovascular system and spinal cord were observed. In the embryo of 14 days, we observed structures that make up the liver and heart. At 18 days of gestation fetuses, it was noted the presence of eyes, mouth, and nose in the cephalic region, chest and pelvic region with the presence of well-developed limbs, umbilical cord, and placenta. Scanning electron microscopy in 18 days of gestation fetuses evidenced head, eyes closed eyelids, nose, vibrissae, forelimb, heart, lung, kidney, liver, small bowel, diaphragm, and part of the spine. The results obtained in this work describe the internal and external morphology of mice, provided by an integration of techniques and review of the morphological knowledge of the embryonic development of this species, as this animal is of great importance to scientific studies. Copyright © 2012 Wiley Periodicals, Inc.

  17. STM-SQUID probe microscope

    International Nuclear Information System (INIS)

    Hayashi, Tadayuki; Tachiki, Minoru; Itozaki, Hideo

    2007-01-01

    We have developed a STM-SQUID probe microscope. A high T C SQUID probe microscope was combined with a scanning tunneling microscope for investigation of samples at room temperature in air. A high permeability probe needle was used as a magnetic flux guide to improve the spatial resolution. The probe with tip radius of less than 100 nm was prepared by microelectropolishing. The probe was also used as a scanning tunneling microscope tip. Topography of the sample surface could be measured by the scanning tunneling microscope with high spatial resolution prior to observation by SQUID microscopy. The SQUID probe microscope image could be observed while keeping the distance from the sample surface to the probe tip constant. We observed a topographic image and a magnetic image of Ni fine pattern and also a magnetically recorded hard disk. Furthermore we have investigated a sample vibration method of the static magnetic field emanating from a sample with the aim of achieving a higher signal-to-noise (S/N) ratio

  18. Portable smartphone based quantitative phase microscope

    Science.gov (United States)

    Meng, Xin; Tian, Xiaolin; Yu, Wei; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Liu, Cheng; Wang, Shouyu

    2018-01-01

    To realize portable device with high contrast imaging capability, we designed a quantitative phase microscope using transport of intensity equation method based on a smartphone. The whole system employs an objective and an eyepiece as imaging system and a cost-effective LED as illumination source. A 3-D printed cradle is used to align these components. Images of different focal planes are captured by manual focusing, followed by calculation of sample phase via a self-developed Android application. To validate its accuracy, we first tested the device by measuring a random phase plate with known phases, and then red blood cell smear, Pap smear, broad bean epidermis sections and monocot root were also measured to show its performance. Owing to its advantages as accuracy, high-contrast, cost-effective and portability, the portable smartphone based quantitative phase microscope is a promising tool which can be future adopted in remote healthcare and medical diagnosis.

  19. DNCON2: improved protein contact prediction using two-level deep convolutional neural networks.

    Science.gov (United States)

    Adhikari, Badri; Hou, Jie; Cheng, Jianlin

    2018-05-01

    Significant improvements in the prediction of protein residue-residue contacts are observed in the recent years. These contacts, predicted using a variety of coevolution-based and machine learning methods, are the key contributors to the recent progress in ab initio protein structure prediction, as demonstrated in the recent CASP experiments. Continuing the development of new methods to reliably predict contact maps is essential to further improve ab initio structure prediction. In this paper we discuss DNCON2, an improved protein contact map predictor based on two-level deep convolutional neural networks. It consists of six convolutional neural networks-the first five predict contacts at 6, 7.5, 8, 8.5 and 10 Å distance thresholds, and the last one uses these five predictions as additional features to predict final contact maps. On the free-modeling datasets in CASP10, 11 and 12 experiments, DNCON2 achieves mean precisions of 35, 50 and 53.4%, respectively, higher than 30.6% by MetaPSICOV on CASP10 dataset, 34% by MetaPSICOV on CASP11 dataset and 46.3% by Raptor-X on CASP12 dataset, when top L/5 long-range contacts are evaluated. We attribute the improved performance of DNCON2 to the inclusion of short- and medium-range contacts into training, two-level approach to prediction, use of the state-of-the-art optimization and activation functions, and a novel deep learning architecture that allows each filter in a convolutional layer to access all the input features of a protein of arbitrary length. The web server of DNCON2 is at http://sysbio.rnet.missouri.edu/dncon2/ where training and testing datasets as well as the predictions for CASP10, 11 and 12 free-modeling datasets can also be downloaded. Its source code is available at https://github.com/multicom-toolbox/DNCON2/. chengji@missouri.edu. Supplementary data are available at Bioinformatics online.

  20. Multiplane optical microscope

    Science.gov (United States)

    Li, Tongcang; Ota, Sadao; Kim, Jeongmin; Wang, Yuan; Zhang, Xiang

    2017-11-21

    This disclosure provides systems, methods, and apparatus related to optical microscopy. In one aspect, an apparatus includes a sample holder, a first objective lens, a plurality of optical components, a second objective lens, and a mirror. The apparatus may directly image a cross-section of a sample oblique to or parallel to the optical axis of the first objective lens, without scanning.

  1. Spectral density of Cooper pairs in two level quantum dot–superconductors Josephson junction

    Energy Technology Data Exchange (ETDEWEB)

    Dhyani, A., E-mail: archana.d2003@gmail.com [Department of Physics, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India); Rawat, P.S. [Department of Nuclear Science and Technology, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India); Tewari, B.S., E-mail: bstewari@ddn.upes.ac.in [Department of Physics, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India)

    2016-09-15

    Highlights: • The present work deals with the study of the electronic spectral density of electron pairs and its effect in charge transport in superconductor-quantum dot-superconductor junctions. • The charge transfer across such junctions can be controlled by changing the positions of the dot level. • The Josephson supercurrent can also be tuned by controlling the position of quantum dot energy levels. - Abstract: In the present paper, we report the role of quantum dot energy levels on the electronic spectral density for a two level quantum dot coupled to s-wave superconducting leads. The theoretical arguments in this work are based on the Anderson model so that it necessarily includes dot energies, single particle tunneling and superconducting order parameter for BCS superconductors. The expression for single particle spectral function is obtained by using the Green's function equation of motion technique. On the basis of numerical computation of spectral function of superconducting leads, it has been found that the charge transfer across such junctions can be controlled by the positions and availability of the dot levels.

  2. Induced absorption and stimulated emission in a driven two-level atom

    International Nuclear Information System (INIS)

    Mavroyannis, C.

    1992-01-01

    We have considered the induced processes that occur in a driven two-level atom, where a laser photon is absorbed and emitted by the ground and by the excited states of the atom, respectively. In the low-intensity limit of the laser field, the induced spectra arising when a laser photon is absorbed by the ground state of the atom consist of two peaks describing induced absorption and stimulated-emission processes, respectively, where the former prevails over the latter. Asymmetry of the spectral lines occurs at off-resonance and its extent depends on the detuning of the laser field. The physical. process where a laser photon is emitted by the excited state is the reverse of that arising from the absorption of a laser photon by the ground state of the atom. The former differs from the latter in that the emission of a laser photon by the excited state occurs in the low frequency regime and that the stimulated-emission process prevails over that of the induced absorption. In this case, amplification of ultrashort pulses is likely to occur without the need of population inversion between the optical transitions. The computed spectra are graphically presented and discussed. (author)

  3. Vorticity, backscatter and counter-gradient transport predictions using two-level simulation of turbulent flows

    Science.gov (United States)

    Ranjan, R.; Menon, S.

    2018-04-01

    The two-level simulation (TLS) method evolves both the large-and the small-scale fields in a two-scale approach and has shown good predictive capabilities in both isotropic and wall-bounded high Reynolds number (Re) turbulent flows in the past. Sensitivity and ability of this modelling approach to predict fundamental features (such as backscatter, counter-gradient turbulent transport, small-scale vorticity, etc.) seen in high Re turbulent flows is assessed here by using two direct numerical simulation (DNS) datasets corresponding to a forced isotropic turbulence at Taylor's microscale-based Reynolds number Reλ ≈ 433 and a fully developed turbulent flow in a periodic channel at friction Reynolds number Reτ ≈ 1000. It is shown that TLS captures the dynamics of local co-/counter-gradient transport and backscatter at the requisite scales of interest. These observations are further confirmed through a posteriori investigation of the flow in a periodic channel at Reτ = 2000. The results reveal that the TLS method can capture both the large- and the small-scale flow physics in a consistent manner, and at a reduced overall cost when compared to the estimated DNS or wall-resolved LES cost.

  4. Robust Methods for Moderation Analysis with a Two-Level Regression Model.

    Science.gov (United States)

    Yang, Miao; Yuan, Ke-Hai

    2016-01-01

    Moderation analysis has many applications in social sciences. Most widely used estimation methods for moderation analysis assume that errors are normally distributed and homoscedastic. When these assumptions are not met, the results from a classical moderation analysis can be misleading. For more reliable moderation analysis, this article proposes two robust methods with a two-level regression model when the predictors do not contain measurement error. One method is based on maximum likelihood with Student's t distribution and the other is based on M-estimators with Huber-type weights. An algorithm for obtaining the robust estimators is developed. Consistent estimates of standard errors of the robust estimators are provided. The robust approaches are compared against normal-distribution-based maximum likelihood (NML) with respect to power and accuracy of parameter estimates through a simulation study. Results show that the robust approaches outperform NML under various distributional conditions. Application of the robust methods is illustrated through a real data example. An R program is developed and documented to facilitate the application of the robust methods.

  5. Multilevel Converter by Cascading Two-Level Three-Phase Voltage Source Converter

    Directory of Open Access Journals (Sweden)

    Abdullrahman A. Al-Shamma’a

    2018-04-01

    Full Text Available This paper proposes a topology using isolated, cascaded multilevel voltage source converters (VSCs and employing two-winding magnetic elements for high-power applications. The proposed topology synthesizes 6 two-level, three-phase VSCs, so the power capability of the presented converter is six times the capability of each VSC module. The characteristics of the proposed topology are demonstrated through analyzing its current relationships, voltage relationships and power capability in detail. The power rating is equally shared among the VSC modules without the need for a sharing algorithm; thus, the converter operates as a single three-phase VSC. The comparative analysis with classical neutral-point clamped, flying capacitor and cascaded H-bridge exhibits the superior features of fewer insulated gate bipolar transistors (IGBTs, capacitor requirement and fewer diodes. To validate the theoretical performance of the proposed converter, it is simulated in a MATLAB/Simulink environment and the results are experimentally demonstrated using a laboratory prototype.

  6. Two-Level Evaluation on Sensor Interoperability of Features in Fingerprint Image Segmentation

    Directory of Open Access Journals (Sweden)

    Ya-Shuo Li

    2012-03-01

    Full Text Available Features used in fingerprint segmentation significantly affect the segmentation performance. Various features exhibit different discriminating abilities on fingerprint images derived from different sensors. One feature which has better discriminating ability on images derived from a certain sensor may not adapt to segment images derived from other sensors. This degrades the segmentation performance. This paper empirically analyzes the sensor interoperability problem of segmentation feature, which refers to the feature’s ability to adapt to the raw fingerprints captured by different sensors. To address this issue, this paper presents a two-level feature evaluation method, including the first level feature evaluation based on segmentation error rate and the second level feature evaluation based on decision tree. The proposed method is performed on a number of fingerprint databases which are obtained from various sensors. Experimental results show that the proposed method can effectively evaluate the sensor interoperability of features, and the features with good evaluation results acquire better segmentation accuracies of images originating from different sensors.

  7. Automatic QRS complex detection using two-level convolutional neural network.

    Science.gov (United States)

    Xiang, Yande; Lin, Zhitao; Meng, Jianyi

    2018-01-29

    The QRS complex is the most noticeable feature in the electrocardiogram (ECG) signal, therefore, its detection is critical for ECG signal analysis. The existing detection methods largely depend on hand-crafted manual features and parameters, which may introduce significant computational complexity, especially in the transform domains. In addition, fixed features and parameters are not suitable for detecting various kinds of QRS complexes under different circumstances. In this study, based on 1-D convolutional neural network (CNN), an accurate method for QRS complex detection is proposed. The CNN consists of object-level and part-level CNNs for extracting different grained ECG morphological features automatically. All the extracted morphological features are used by multi-layer perceptron (MLP) for QRS complex detection. Additionally, a simple ECG signal preprocessing technique which only contains difference operation in temporal domain is adopted. Based on the MIT-BIH arrhythmia (MIT-BIH-AR) database, the proposed detection method achieves overall sensitivity Sen = 99.77%, positive predictivity rate PPR = 99.91%, and detection error rate DER = 0.32%. In addition, the performance variation is performed according to different signal-to-noise ratio (SNR) values. An automatic QRS detection method using two-level 1-D CNN and simple signal preprocessing technique is proposed for QRS complex detection. Compared with the state-of-the-art QRS complex detection approaches, experimental results show that the proposed method acquires comparable accuracy.

  8. Injury patterns of child abuse: Experience of two Level 1 pediatric trauma centers.

    Science.gov (United States)

    Yu, Yangyang R; DeMello, Annalyn S; Greeley, Christopher S; Cox, Charles S; Naik-Mathuria, Bindi J; Wesson, David E

    2018-05-01

    This study examines non-accidental trauma (NAT) fatalities as a percentage of all injury fatalities and identifies injury patterns in NAT admissions to two level 1 pediatric trauma centers. We reviewed all children (<5years old) treated for NAT from 2011 to 2015. Patient demographics, injury sites, and survival were obtained from both institutional trauma registries. Of 4623 trauma admissions, 557 (12%) were due to NAT. However, 43 (46%) of 93 overall trauma fatalities were due to NAT. Head injuries were the most common injuries sustained (60%) and led to the greatest increased risk of death (RR 5.1, 95% CI 2.0-12.7). Less common injuries that increased the risk of death were facial injuries (14%, RR 2.9, 95% CI 1.6-5.3), abdominal injuries (8%, RR 2.8, 95% CI 1.4-5.6), and spinal injuries (3%, RR 3.9, 95% CI 1.8-8.8). Although 76% of head injuries occurred in infants <1year, children ages 1-4years old with head injuries had a significantly higher case fatality rate (27% vs. 6%, p<0.001). Child abuse accounts for a large proportion of trauma fatalities in children under 5years of age. Intracranial injuries are common in child abuse and increase the risk of death substantially. Preventing NAT in infants and young children should be a public health priority. Retrospective Review. II. Copyright © 2018. Published by Elsevier Inc.

  9. Risk Analysis of a Two-Level Supply Chain Subject to Misplaced Inventory

    Directory of Open Access Journals (Sweden)

    Lijing Zhu

    2017-06-01

    Full Text Available Misplaced inventory is prevalent in retail stores and may lead to the overall poor performance of the supply chain. We explore the impact of misplaced inventory on a two-level supply chain, which consists of a risk-neutral supplier and a risk-averse retailer. The supplier decides the wholesale price to maximize her profit, whereas the retailer decides the order quantity to maximize his utility. Under the Conditional Value-at-Risk (CVaR criterion, we formulate the problem as a Stackelberg game model and obtain the equilibrium solutions in three cases: (i information asymmetry about inventory errors exists; (ii the retailer shares information about inventory errors with the supplier; and (iii in order to reduce misplaced inventory, the supply chain deploys Radio-Frequency Identification (RFID technology. The benefits of information sharing and RFID implementation are explored. A revenue and cost sharing contract is proposed to coordinate the supply chain and to allocate the cost savings from RFID implementation among supply chain participants. Finally, we provide managerial insights for risk-averse decision makers that are considering investing in the RFID technology.

  10. Two level undercut-profile substrate-based filamentary coated conductors produced using metal organic chemical vapor deposition

    DEFF Research Database (Denmark)

    Insinga, Andrea R.; Sundaram, Aarthi; Hazelton, Drew W.

    2018-01-01

    The two level undercut-profile substrate (2LUPS) has been introduced as a concept for subdividing rare-earth-Ba$_{2}$Cu$_{3}$O$_{7}$ (REBCO) coated conductors (CC) into narrow filaments which reduces the AC losses and improves field stability for DC magnets. The 2LUPS consists of two levels...

  11. An electron microscope for the aberration-corrected era

    Energy Technology Data Exchange (ETDEWEB)

    Krivanek, O.L. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)], E-mail: krivanek.ondrej@gmail.com; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)

    2008-02-15

    Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown.

  12. An electron microscope for the aberration-corrected era

    International Nuclear Information System (INIS)

    Krivanek, O.L.; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W.

    2008-01-01

    Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown

  13. Microelectromechanical system device for calibration of atomic force microscope cantilever spring constants between 0.01 and 4 N/m

    International Nuclear Information System (INIS)

    Cumpson, Peter J.; Hedley, John; Clifford, Charles A.; Chen Xinyong; Allen, Stephanie

    2004-01-01

    Calibration of atomic force microscope (AFM) cantilevers is necessary for the measurement of nano-newton and pico-newton forces, which are critical to analytical application of AFM in the analysis of polymer surfaces, biological structures and organic molecules. Previously we have described microfabricated array of reference spring (MARS) devices for AFM cantilever spring-constant calibration. Hitherto, these have been limited to the calibration of AFM cantilevers above 0.03 N/m, although they can be used to calibrate cantilevers of lower stiffness with reduced accuracy. Below this limit MARS devices similar to the designs hitherto described would be fragile and difficult to manufacture with reasonable yield. In this work we describe a device we call torsional MARS. This is a large-area torsional mechanical resonator, manufactured by bulk micromachining of a 'silicon-on-insulator' wafer. By measuring its torsional oscillation accurately in vacuum we can deduce its torsional spring constant. The torsional reference spring spans the range of spring constant (from 4 down to 0.01 N/m) that is important in biological AFM, allowing even the most compliant AFM cantilever to be calibrated easily and rapidly

  14. Scanning electron microscopic evaluation of root canal surfaces ...

    African Journals Online (AJOL)

    Scanning electron microscopic evaluation of root canal surfaces prepared with three rotary endodontic systems: Lightspeed, ProTaper and EndoWave. ... fracture with LightSpeed (LS), ProTaper (PT) and EndoWave (Ew) rotary instruments.

  15. Demand response strategy management with active and reactive power incentive in the smart grid: a two-level optimization approach

    Directory of Open Access Journals (Sweden)

    Ryuto Shigenobu

    2017-05-01

    Full Text Available High penetration of distributed generators (DGs using renewable energy sources (RESs is raising some important issues in the operation of modern po­wer system. The output power of RESs fluctuates very steeply, and that include uncertainty with weather conditions. This situation causes voltage deviation and reverse power flow. Several methods have been proposed for solving these problems. Fundamentally, these methods involve reactive power control for voltage deviation and/or the installation of large battery energy storage system (BESS at the interconnection point for reverse power flow. In order to reduce the installation cost of static var compensator (SVC, Distribution Company (DisCo gives reactive power incentive to the cooperating customers. On the other hand, photovoltaic (PV generator, energy storage and electric vehicle (EV are introduced in customer side with the aim of achieving zero net energy homes (ZEHs. This paper proposes not only reactive power control but also active power flow control using house BESS and EV. Moreover, incentive method is proposed to promote participation of customers in the control operation. Demand response (DR system is verified with several DR menu. To create profit for both side of DisCo and customer, two level optimization approach is executed in this research. Mathematical modeling of price elasticity and detailed simulations are executed by case study. The effectiveness of the proposed incentive menu is demonstrated by using heuristic optimization method.

  16. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1990-01-01

    Our laboratory has made significant progress this year in devising improved electron-optical systems, in studying invertebrate hemoglobins with the STEM, and in achieving a workable sub-angstrom STEM. Our goal in electron optics is to improve resolution by producing spherical and chromatic aberration coefficients with signs opposite those of magnetic lenses. We have progressed toward this goal through calculations that explore the addition of electrodes to electron mirrors to reduce these two geometric aberrations and by devising a beam separation system that won't introduce asymmetrical aberrations. Some promising new designs of magnetic lenses for SEM applications have also been investigated. We have continued our exploration of the quaternary structure of the invertebrate hemoglobins and are now among the top laboratories in this area of expertise. In addition, we have overcome many of our electronic difficulties on the sub-angstrom STEM and have made significant progress toward achieving an operational system. The addition of an IBM RISC-6000 workstation to our lab has significantly increased our image processing capabilities

  17. Ponderomotive phase plate for transmission electron microscopes

    Science.gov (United States)

    Reed, Bryan W [Livermore, CA

    2012-07-10

    A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

  18. Axiomatic electrodynamics and microscopic mechanics

    International Nuclear Information System (INIS)

    Yussouff, M.

    1981-04-01

    A new approach to theoretical physics, along with the basic formulation of a new MICROSCOPIC MECHANICS for the motion of small charged particles is described in this set of lecture notes. Starting with the classical (Newtonian) mechanics and classical fields, the important but well known properties of Classical Electromagnetic field are discussed up to section 4. The next nection describes the usual radiation damping theory and its difficulties. It is argued that the usual treatment of radiation damping is not valid for small space and time intervals and the true description of motion requires a new type of mechanics - the MICROSCOPIC MECHANICS: Section 6 and 7 are devoted to showing that not only the new microscopic mechanics goes over to Newtonian mechanics in the proper limit, but also it is closely connected with Quantum Mechanics. All the known results of the Schroedinger theory can be reproduced by microscopic mechanics which also gives a clear physical picture. It removes Einstein's famous objections against Quantum Theory and provides a clear distinction between classical and Quantum behavior. Seven Axioms (three on Classical Mechanics, two for Maxwell's theory, one for Relativity and a new Axiom on Radiation damping) are shown to combine Classical Mechanics, Maxwellian Electrodynamics, Relativity and Schroedinger's Quantum Theory within a single theoretical framework under Microscopic Mechanics which awaits further development at the present time. (orig.)

  19. Absorption spectrum of a two-level atom in a bad cavity with injected squeezed vacuum

    Science.gov (United States)

    Zhou, Peng; Swain, S.

    1996-02-01

    We study the absorption spectrum of a coherently driven two-level atom interacting with a resonant cavity mode which is coupled to a broadband squeezed vacuum through its input-output mirror in the bad cavity limit. We study the modification of the two-photon correlation strength of the injected squeezed vacuum inside the cavity, and show that the equations describing probe absorption in the cavity environment are formally identical to these in free space, but with modified parameters describing the squeezed vacuum. The two photon correlations induced by the squeezed vacuum are always weaker than in free space. We pay particular attention to the spectral behaviour at line centre in the region of intermediate trength driving intensities, where anomalous spectral features such as hole-burning and dispersive profiles are displayed. These unusual spectral features are very sensitive to the squeezing phase and the Rabi frequency of the driving field. We also derive the threshold value of the Rabi frequency which gives rise to the transparency of the probe beam at the driving frequency. When the Rabi frequency is less than the threshold value, the probe beam is absorbed, whilst the probe beam is amplified (without population inversion under certain conditions) when the Rabi frequency is larger than this threshold. The anomalous spectral features all take place in the vicinity of the critical point dividing the different dynamical regimes, probe absorption and amplification, of the atomic radiation. The physical origin of the strong amplification without population inversion, and the feasibility of observing it, are discussed.

  20. A two level mutation-selection model of cultural evolution and diversity.

    Science.gov (United States)

    Salazar-Ciudad, Isaac

    2010-11-21

    Cultural evolution is a complex process that can happen at several levels. At the level of individuals in a population, each human bears a set of cultural traits that he or she can transmit to its offspring (vertical transmission) or to other members of his or her society (horizontal transmission). The relative frequency of a cultural trait in a population or society can thus increase or decrease with the relative reproductive success of its bearers (individual's level) or the relative success of transmission (called the idea's level). This article presents a mathematical model on the interplay between these two levels. The first aim of this article is to explore when cultural evolution is driven by the idea's level, when it is driven by the individual's level and when it is driven by both. These three possibilities are explored in relation to (a) the amount of interchange of cultural traits between individuals, (b) the selective pressure acting on individuals, (c) the rate of production of new cultural traits, (d) the individual's capacity to remember cultural traits and to the population size. The aim is to explore the conditions in which cultural evolution does not lead to a better adaptation of individuals to the environment. This is to contrast the spread of fitness-enhancing ideas, which make individual bearers better adapted to the environment, to the spread of "selfish" ideas, which spread well simply because they are easy to remember but do not help their individual bearers (and may even hurt them). At the same time this article explores in which conditions the adaptation of individuals is maximal. The second aim is to explore how these factors affect cultural diversity, or the amount of different cultural traits in a population. This study suggests that a larger interchange of cultural traits between populations could lead to cultural evolution not improving the adaptation of individuals to their environment and to a decrease of cultural diversity

  1. Analytical model of the optical vortex microscope.

    Science.gov (United States)

    Płocinniczak, Łukasz; Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2016-04-20

    This paper presents an analytical model of the optical vortex scanning microscope. In this microscope the Gaussian beam with an embedded optical vortex is focused into the sample plane. Additionally, the optical vortex can be moved inside the beam, which allows fine scanning of the sample. We provide an analytical solution of the whole path of the beam in the system (within paraxial approximation)-from the vortex lens to the observation plane situated on the CCD camera. The calculations are performed step by step from one optical element to the next. We show that at each step, the expression for light complex amplitude has the same form with only four coefficients modified. We also derive a simple expression for the vortex trajectory of small vortex displacements.

  2. Design and development of compact multiphoton microscopes

    Science.gov (United States)

    Mehravar, SeyedSoroush

    A compact multi-photon microscope (MPM) was designed and developed with the use of low-cost mode-locked fiber lasers operating at 1040nm and 1560nm. The MPM was assembled in-house and the system aberration was investigated using the optical design software: Zemax. A novel characterization methodology based on 'nonlinear knife-edge' technique was also introduced to measure the axial, lateral resolution, and the field curvature of the multi-photon microscope's image plane. The field curvature was then post-corrected using data processing in MATLAB. A customized laser scanning software based on LabVIEW was developed for data acquisition, image display and controlling peripheral electronics. Finally, different modalities of multi-photon excitation such as second- and third harmonic generation, two- and three-photon fluorescence were utilized to study a wide variety of samples from cancerous cells to 2D-layered materials.

  3. Polarized differential-phase laser scanning microscope

    International Nuclear Information System (INIS)

    Chou Chien; Lyu, C.-W.; Peng, L.-C.

    2001-01-01

    A polarized differential-phase laser scanning microscope, which combines a polarized optical heterodyne Mach-Zehnder interferometer and a differential amplifier to scan the topographic image of a surface, is proposed. In the experiment the differential amplifier, which acts as a PM-AM converter, in the experiment, converting phase modulation (PM) into amplitude modulation (AM). Then a novel, to our knowledge, phase demodulator was proposed and implemented for the differential-phase laser scanning microscope. An optical grating (1800 lp/mm) was imaged. The lateral and the depth resolutions of the imaging system were 0.5 μm and 1 nm, respectively. The detection accuracy, which was limited by the reflectivity variation of the test surface, is discussed

  4. Development of Scanning Ultrafast Electron Microscope Capability.

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Kimberlee Chiyoko [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Talin, Albert Alec [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Chandler, David W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Michael, Joseph R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Modern semiconductor devices rely on the transport of minority charge carriers. Direct examination of minority carrier lifetimes in real devices with nanometer-scale features requires a measurement method with simultaneously high spatial and temporal resolutions. Achieving nanometer spatial resolutions at sub-nanosecond temporal resolution is possible with pump-probe methods that utilize electrons as probes. Recently, a stroboscopic scanning electron microscope was developed at Caltech, and used to study carrier transport across a Si p-n junction [ 1 , 2 , 3 ] . In this report, we detail our development of a prototype scanning ultrafast electron microscope system at Sandia National Laboratories based on the original Caltech design. This effort represents Sandia's first exploration into ultrafast electron microscopy.

  5. Microscopic collective models of nuclei

    International Nuclear Information System (INIS)

    Lovas, Rezsoe

    1985-01-01

    Microscopic Rosensteel-Rowe theory of the nuclear collective motion is described. The theoretical insufficiency of the usual microscopic establishment of the collective model is pointed. The new model treating exactly the degrees of freedom separates the coordinates describing the collective motion and the internal coordinates by a consistent way. Group theoretical methods analyzing the symmetry properties of the total Hamiltonian are used defining the collective subspaces transforming as irreducible representations of the group formed by the collective operators. Recent calculations show that although the results of the usual collective model are approximately correct and similar to those of the new microscopic collective model, the underlying philosophy of the old model is essentially erroneous. (D.Gy.)

  6. Microscope and method of use

    Science.gov (United States)

    Bongianni, Wayne L.

    1984-01-01

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

  7. Quality of Service-Driven Requirements Analyses for Component Composition: A Two-Level Grammar++ Approach

    National Research Council Canada - National Science Library

    Liu, Shih-Hsi; Cao, Fei; Bryant, Barrett R; Gray, Jeff; Raje, Rajeev R; Olson, Andrew M; Auguston, Mikhail

    2005-01-01

    .... When applied to Distributed Real-Time and Embedded (DRE) systems, which components to assemble and how to assemble them are determined not only from functional correctness criteria but also assurance of the system's quality of service (QoS...

  8. Atomic force microscope featuring an integrated optical microscope

    NARCIS (Netherlands)

    Putman, C.A.J.; Putman, Constant A.J.; de Grooth, B.G.; van Hulst, N.F.; Greve, Jan

    1992-01-01

    The atomic force microscope (AFM) is used to image the surface of both conductors and nonconductors. Biological specimens constitute a large group of nonconductors. A disadvantage of most AFM's is the fact that relatively large areas of the sample surface have to be scanned to pinpoint a biological

  9. Optical microscope for three-dimensional surface displacement and shape measurements at the microscale.

    Science.gov (United States)

    Xia, Shuman; Pan, Zhipeng; Zhang, Jingwen

    2014-07-15

    We report a novel optical microscope for full-field, noncontact measurements of three-dimensional (3D) surface deformation and topography at the microscale. The microscope system is based on a seamless integration of the diffraction-assisted image correlation (DAIC) method with fluorescent microscopy. We experimentally demonstrate the microscope's capability for 3D measurements with submicrometer spatial resolution and subpixel measurement accuracy.

  10. Designs for a quantum electron microscope

    International Nuclear Information System (INIS)

    Kruit, P.; Hobbs, R.G.; Kim, C-S.; Yang, Y.; Manfrinato, V.R.; Hammer, J.; Thomas, S.; Weber, P.; Klopfer, B.; Kohstall, C.; Juffmann, T.; Kasevich, M.A.; Hommelhoff, P.; Berggren, K.K.

    2016-01-01

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This ‘quantum weirdness’ could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or “quantum electron microscope”. A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. - Highlights: • Quantum electron microscopy has the potential of reducing radiation damage. • QEM requires a fraction of the electron wave to pass through the sample

  11. Designs for a quantum electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Kruit, P., E-mail: p.kruit@tudelft.nl [Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); Hobbs, R.G.; Kim, C-S.; Yang, Y.; Manfrinato, V.R. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hammer, J.; Thomas, S.; Weber, P. [Department of Physics, Friedrich Alexander University Erlangen-Nürnberg (FAU), Staudtstrasse 1, d-91058 Erlangen (Germany); Klopfer, B.; Kohstall, C.; Juffmann, T.; Kasevich, M.A. [Department of Physics, Stanford University, Stanford, California 94305 (United States); Hommelhoff, P. [Department of Physics, Friedrich Alexander University Erlangen-Nürnberg (FAU), Staudtstrasse 1, d-91058 Erlangen (Germany); Berggren, K.K. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2016-05-15

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This ‘quantum weirdness’ could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or “quantum electron microscope”. A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. - Highlights: • Quantum electron microscopy has the potential of reducing radiation damage. • QEM requires a fraction of the electron wave to pass through the sample

  12. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1991-01-01

    This year our laboratory has continued to make progress in the design of electron-optical systems, in the study of structure-function relationships of large multi-subunit proteins, in the development of new image processing software and in achieving a workable sub-angstrom STEM. We present an algebraic approach to the symmetrical Einzel (unipotential) lens wherein we simplify the analysis by specifying a field shape that meets some preferred set of boundary or other conditions and then calculate the fields. In a second study we generalize this approach to study of three element electrostatic lenses of which the symmetrical Einzel lens is a particular form. The purpose is to develop a method for assisting in the design of a lens for a particular purpose. In our biological work we study a stable and functional dodecameric complex of globin chains from the hemoglobin of Lumbricus terrestris. This is a complex lacking the ''linker'' subunit first imaged in this lab and required for maintenance of the native structure. In addition, we do a complete work-up on the hemoglobin of the marine polychaete Eudistylia vancouverii demonstrating the presence of a hierarchy of globin complexes. We demonstrate stable field-emission in the sub-angstrom STEM and the preliminary alignment of the beam. We continue our exploration of a algorithms for alignment of sequences of protein and DNA. Our computer facilities now include four second generation RISC workstations and we continue to take increasing advantage of the floating-point and graphical performance of these devices

  13. Two-Level Chebyshev Filter Based Complementary Subspace Method: Pushing the Envelope of Large-Scale Electronic Structure Calculations.

    Science.gov (United States)

    Banerjee, Amartya S; Lin, Lin; Suryanarayana, Phanish; Yang, Chao; Pask, John E

    2018-06-12

    We describe a novel iterative strategy for Kohn-Sham density functional theory calculations aimed at large systems (>1,000 electrons), applicable to metals and insulators alike. In lieu of explicit diagonalization of the Kohn-Sham Hamiltonian on every self-consistent field (SCF) iteration, we employ a two-level Chebyshev polynomial filter based complementary subspace strategy to (1) compute a set of vectors that span the occupied subspace of the Hamiltonian; (2) reduce subspace diagonalization to just partially occupied states; and (3) obtain those states in an efficient, scalable manner via an inner Chebyshev filter iteration. By reducing the necessary computation to just partially occupied states and obtaining these through an inner Chebyshev iteration, our approach reduces the cost of large metallic calculations significantly, while eliminating subspace diagonalization for insulating systems altogether. We describe the implementation of the method within the framework of the discontinuous Galerkin (DG) electronic structure method and show that this results in a computational scheme that can effectively tackle bulk and nano systems containing tens of thousands of electrons, with chemical accuracy, within a few minutes or less of wall clock time per SCF iteration on large-scale computing platforms. We anticipate that our method will be instrumental in pushing the envelope of large-scale ab initio molecular dynamics. As a demonstration of this, we simulate a bulk silicon system containing 8,000 atoms at finite temperature, and obtain an average SCF step wall time of 51 s on 34,560 processors; thus allowing us to carry out 1.0 ps of ab initio molecular dynamics in approximately 28 h (of wall time).

  14. PC-based digital feedback control for scanning force microscope

    International Nuclear Information System (INIS)

    Mohd Ashhar Khalid

    2002-01-01

    In the past, most digital feedback implementation for scanned-probe microscope were based on a digital signal processor (DSP). At present DSP plug-in card with the input-output interface module is still expensive compared to a fast pentium PC motherboard. For a magnetic force microscope (MFM) digital feedback has an advantage where the magnetic signal can be easily separated from the topographic signal. In this paper, a simple low-cost PC-based digital feedback and imaging system for Scanning Force Microscope (SFM) is presented. (Author)

  15. An Efficient Data Fingerprint Query Algorithm Based on Two-Leveled Bloom Filter

    OpenAIRE

    Bin Zhou; Rongbo Zhu; Ying Zhang; Linhui Cheng

    2013-01-01

    The function of the comparing fingerprints algorithm was to judge whether a new partitioned data chunk was in a storage system a decade ago.  At present, in the most de-duplication backup system the fingerprints of the big data chunks are huge and cannot be stored in the memory completely. The performance of the system is unavoidably retarded by data chunks accessing the storage system at the querying stage. Accordingly, a new query mechanism namely Two-stage Bloom Filter (TBF) mechanism...

  16. First Sample Delivery to Mars Microscope

    Science.gov (United States)

    2008-01-01

    The Robotic Arm on NASA's Phoenix Mars Lander has just delivered the first sample of dug-up soil to the spacecraft's microscope station in this image taken by the Surface Stereo Imager during the mission's Sol 17 (June 12), or 17th Martian day after landing. The scoop is positioned above the box containing key parts of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer, or MECA, instrument suite. It has sprinkled a small amount of soil into a notch in the MECA box where the microscope's sample wheel is exposed. The wheel turns to present sample particles on various substrates to the Optical Microscope for viewing. The scoop is about 8.5 centimeters (3.3 inches) wide. The top of the MECA box is 20 centimeters (7.9 inches) wide. This image has been lightened to make details more visible. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. Scanning tunneling microscope nanoetching method

    Science.gov (United States)

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  18. Microscopic cross sections: An utopia?

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

    2010-07-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  19. Microscopic cross sections: An utopia?

    International Nuclear Information System (INIS)

    Hilaire, S.; Koning, A.J.; Goriely, S.

    2010-01-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  20. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a