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Sample records for on-line nonlinear chromaticity

  1. ON-LINE NONLINEAR CHROMATICITY CORRECTION USING OFF-MOMENTUM TUNE RESPONSE MATRIX

    International Nuclear Information System (INIS)

    LUO, Y.; FISCHER, W.; MALISKY, N.; TEPIKIAN, S.; TROBJEVIC, D.

    2007-01-01

    In this article, we propose a method for the online nonlinear chromaticity correction at store in the Relativistic Heavy Ion Collider (RHIC). With 8 arc sextupole families in each RHIC ring, the nonlinear chromaticities can be minimized online by matching the off-momentum tunes onto the wanted tunes given by the linear chromaticities. The Newton method is used for this multi-dimensional nonlinear optimization, where the off-momentum tune response matrix with respect to sextupole strength changes is adopted. The off-momentum tune response matrix can be calculated with the online accelerator optics model or directly measured with the real beam. In this article, the correction algorithm for the RHIC is presented. Simulations are also carried out to verify the method. The preliminary results from the beam experiments taken place in the RHIC 2007 Au run are reviewed

  2. Formulation of nonlinear chromaticity in circular accelerators by canonical perturbation method

    International Nuclear Information System (INIS)

    Takao, Masaru

    2005-01-01

    The formulation of nonlinear chromaticity in circular accelerators based on the canonical perturbation method is presented. Since the canonical perturbation method directly relates the tune shift to the perturbation Hamiltonian, it greatly simplifies the calculation of the nonlinear chromaticity. The obtained integral representation for nonlinear chromaticity can be systematically extended to higher orders

  3. Chromaticity

    International Nuclear Information System (INIS)

    Guiducci, S.

    1991-01-01

    A simple calculation of the contribution of quadrupoles and sextupoles to storage ring chromaticity is given. Problems arising from chromaticity carrection are discussed. An accurate derivation of chromaticity formulae for a general bending magnet, exact also for small machines with small radius of curvature, is given

  4. Deciding the On-line Chromatic Number of a Graph with Pre-coloring is PSPACE-complete

    DEFF Research Database (Denmark)

    Kudahl, Christian

    2015-01-01

    In an on-line coloring, the vertices of a graph are revealed one by one. An algorithm assigns a color to each vertex after it is revealed. When a vertex is revealed, it is also revealed which of the previous vertices it is adjacent to. The on-line chromatic number of a graph, G, is the smallest...... number of colors an algorithm will need when on-line-coloring G. The algorithm may know G, but not the order in which the vertices are revealed. The problem of determining if the on-line chromatic number of a graph is less than or equal to k, given a pre-coloring, is shown to be PSPACE-complete....

  5. On-line control of the nonlinear dynamics for synchrotrons

    Science.gov (United States)

    Bengtsson, J.; Martin, I. P. S.; Rowland, J. H.; Bartolini, R.

    2015-07-01

    We propose a simple approach to the on-line control of the nonlinear dynamics in storage rings, based on compensation of the nonlinear resonance driving terms using beam losses as the main indicator of the strength of a resonance. The correction scheme is built on the analysis of the resonance driving terms in first perturbative order and on the possibility of using independent power supplies in the sextupole magnets, which is nowadays present in many synchrotron light sources. Such freedom allows the definition of "smart sextupole knobs" attacking each resonance separately. The compensation scheme has been tested at the Diamond light source and proved to be effective in opening up the betatron tune space, resonance free, available to the electron beam and to improve the beam lifetime.

  6. On-line control of the nonlinear dynamics for synchrotrons

    Directory of Open Access Journals (Sweden)

    J. Bengtsson

    2015-07-01

    Full Text Available We propose a simple approach to the on-line control of the nonlinear dynamics in storage rings, based on compensation of the nonlinear resonance driving terms using beam losses as the main indicator of the strength of a resonance. The correction scheme is built on the analysis of the resonance driving terms in first perturbative order and on the possibility of using independent power supplies in the sextupole magnets, which is nowadays present in many synchrotron light sources. Such freedom allows the definition of “smart sextupole knobs” attacking each resonance separately. The compensation scheme has been tested at the Diamond light source and proved to be effective in opening up the betatron tune space, resonance free, available to the electron beam and to improve the beam lifetime.

  7. Measurements and Modelling of Nonlinear Chromaticity and Detuning with Amplitude at 26 GeV

    CERN Document Server

    Arduini, Gianluigi; Zimmermann, Frank; CERN. Geneva. SPS and LHC Division

    2001-01-01

    During electron-cloud MDs in October 2000, nonlinear chromaticity and amplitude-dependent detuning were measured with a 48-bunch LHC batch at 26 GeV. By fitting these data to an SPS optics model, we determine the magnitude of sextupole and decapole components in the SPS dipole magnets and octupole components in the quadrupoles which would be consistent with the measurement. Using the procedure developed, in the future the nonlinear SPS optics model can quickly be updated from a standard set of measurements.

  8. Nonlinear surge motions of a ship in bi-chromatic following waves

    Science.gov (United States)

    Spyrou, Kostas J.; Themelis, Nikos; Kontolefas, Ioannis

    2018-03-01

    Unintended motions of a ship operating in steep and long following waves are investigated. A well-known such case is ;surf-riding; where a ship is carried forward by a single wave, an event invoking sometimes lateral instability and even capsize. The dynamics underlying this behavior has been clarified earlier for monochromatic waves. However, the unsteadiness of the phase space associated with ship behavior in a multichromatic sea, combined with the intrinsically strong system nonlinearity, pose new challenges. Here, current theory is extended to cover surging and surf-riding behavior in unidirectional bi-chromatic waves encountering a ship from the stern. Excitation is provided by two unidirectional harmonic wave components having their lengths comparable to the ship length and their frequencies in rational ratio. The techniques applied include (a) continuation analysis; (b) tracking of Lagrangian coherent structures in phase space, approximated through a finite-time Lyapunov exponents' calculation; and (c) large scale simulation. A profound feature of surf-riding in bi-chromatic waves is that it is turned oscillatory. Initially it appears as a frequency-locked motion, ruled by the harmonic wave component dominating the excitation. Transformations of oscillatory surf-riding are realized as the waves become steeper. In particular, heteroclinic tanglings are identified, governing abrupt transitions between qualitatively different motions. Chaotic transients, as well as long-term chaotic motions, exist near to these events. Some extraordinary patterns of ship motion are discovered. These include a counterintuitive low speed motion at very high wave excitation level; and a hybrid motion characterized by a wildly fluctuating velocity. Due to the quite generic nature of the core mathematical model of our investigation, the current results are believed to offer clues about the behavior of a class of nonlinear dynamical systems having in their modeling some analogy with

  9. Spectroscopic On-Line Monitoring of Cu/W Contacts Erosion in HVCBs Using Optical-Fibre Based Sensor and Chromatic Methodology.

    Science.gov (United States)

    Wang, Zhixiang; Jones, Gordon R; Spencer, Joseph W; Wang, Xiaohua; Rong, Mingzhe

    2017-03-06

    Contact erosion is one of the most crucial factors affecting the electrical service lifetime of high-voltage circuit breakers (HVCBs). On-line monitoring the contacts' erosion degree is increasingly in demand for the sake of condition based maintenance to guarantee the functional operation of HVCBs. A spectroscopic monitoring system has been designed based upon a commercial 245 kV/40 kA S F 6 live tank circuit breaker with copper-tungsten (28 wt % and 72 wt %) arcing contacts at atmospheric S F 6 pressure. Three optical-fibre based sensors are used to capture the time-resolved spectra of arcs. A novel approach using chromatic methods to process the time-resolved spectral signal has been proposed. The processed chromatic parameters have been interpreted to show that the time variation of spectral emission from the contact material and quenching gas are closely correlated to the mass loss and surface degradation of the plug arcing contact. The feasibility of applying this method to online monitoring of contact erosion is indicated.

  10. Spectroscopic On-Line Monitoring of Cu/W Contacts Erosion in HVCBs Using Optical-Fibre Based Sensor and Chromatic Methodology

    Directory of Open Access Journals (Sweden)

    Zhixiang Wang

    2017-03-01

    Full Text Available Contact erosion is one of the most crucial factors affecting the electrical service lifetime of high-voltage circuit breakers (HVCBs. On-line monitoring the contacts’ erosion degree is increasingly in demand for the sake of condition based maintenance to guarantee the functional operation of HVCBs. A spectroscopic monitoring system has been designed based upon a commercial 245 kV/40 kA S F 6 live tank circuit breaker with copper–tungsten (28 wt % and 72 wt % arcing contacts at atmospheric S F 6 pressure. Three optical-fibre based sensors are used to capture the time-resolved spectra of arcs. A novel approach using chromatic methods to process the time-resolved spectral signal has been proposed. The processed chromatic parameters have been interpreted to show that the time variation of spectral emission from the contact material and quenching gas are closely correlated to the mass loss and surface degradation of the plug arcing contact. The feasibility of applying this method to online monitoring of contact erosion is indicated.

  11. On-line Multiple-model Based Adaptive Control Reconfiguration for a Class of Non-linear Control Systems

    DEFF Research Database (Denmark)

    Yang, Z.; Izadi-Zamanabadi, R.; Blanke, Mogens

    2000-01-01

    of LTI models are employed to approximate the faulty, reconfigured and nominal nonlinear systems respectively with respect to the on-line information of the operating system, and a set of compensating modules are proposed and designed so as to make the local LTI model approximating to the reconfigured...... nonlinear system match the corresponding LTI model approximating to the nominal nonlinear system in some optimal sense. The compensating modules are designed by the Pseudo-Inverse Method based on the local LTI models for the nominal and faulty nonlinear systems. Moreover, these modules should update...... corresponding to the updating of local LTI models, which validations are determined by the model approximation errors and the optimal index of local design. The test on a nonlinear ship propulsion system shows the promising potential of this method for system reconfiguration...

  12. Tellurite Composite Microstructured Optical Fibers with Tailored Chromatic Dispersion for Nonlinear Applications

    Science.gov (United States)

    Duan, Zhongchao; Liao, Meisong; Yan, Xin; Kito, Chihiro; Suzuki, Takenobu; Ohishi, Yasutake

    2011-07-01

    We report the fabrication of tellurite composite microstructured optical fibers (CMOFs) which consist of a TeO2-Li2O-WO3-MoO3-Nb2O5 (TLWMN) tellurite glass core and TeO2-ZnO-Na2O-La2O3 (TZNL) tellurite glass cladding. Flattened chromatic dispersion and tunable zero dispersion wavelength (ZDW) were realized in the small core diameter (˜1.5 µm) fiber with six surrounding air holes. The optical loss was measured to be about 4.0 dB/m in the spectral range of 1510-1640 nm. Supercontinuum (SC) generation was demonstrated by a femtosecond laser pumping at 1.55 µm. The threshold pump power for this novel tellurite CMOF was the lowest among tellurite microstructured optical fibers (MOFs).

  13. Chromatic completion

    OpenAIRE

    Barthel, Tobias

    2014-01-01

    We study the limit of the chromatic tower for not necessarily finite spectra, obtaining a generalization of the chromatic convergence theorem of Hopkins and Ravenel. Moreover, we prove that in general this limit does not coincide with harmonic localization, thereby answering a question of Ravenel's.

  14. Monte Carlo aided treatments of the nonlinear inverse PGNAA measurement problem for various continuous on-line applications

    International Nuclear Information System (INIS)

    Gardner, R.P.; Guo, P.; Sood, A.; Mayo, C.W.; Dobbs, C.L.

    1998-01-01

    A review of our work on the application of the PGNAA method as applied to five industrial applications is given. Some introductory material is first given on the importance and use of Monte Carlo simulation in this area, some comments on the place of PGNAA in elemental analysis, and a brief description of the Monte Carlo - Library Least-Squares (MCLLS) approach to the nonlinear inverse PGNAA analysis problem. Then the applications of PGNAA are discussed for: (1) on-line bulk coal analysis, (2) nuclear oil well logging, (3) vitrified waste, (4) the analysis of sodium and aluminium in 'green liquor' in the presence of chlorine, and (5) the conveyor belt sorting of aluminum alloy samples. It is concluded that PGNAA is a rapidly emerging important new technology and measurement approach. (author)

  15. Skew chromaticity

    International Nuclear Information System (INIS)

    Peggs, S.; Dell, G.F.

    1994-01-01

    The on-momentum description of linear coupling between horizontal and vertical betatron motion is extended to include off-momentum particles, introducing a vector quantity called the ''skew chromaticity''. This vector tends to be long in large superconducting storage rings, where it restricts the available working space in the tune plane, and modifies collective effect stability criteria. Skew chromaticity measurements at the Cornell Electron Storage Ring (CESR) and at the Fermilab Tevatron are reported, as well as tracking results from the Relativistic Heavy Ion Collider (RHIC). The observation of anomalous head-tail beam Iowa new the tune diagonal in the Tevatron are explained in terms of the extended theory, including modified criteria for headtail stability. These results are confirmed in head-tail simulations. Sources of skew chromaticity are investigated

  16. Chromatic Derivatives, Chromatic Expansions and Associated Spaces

    OpenAIRE

    Ignjatovic, Aleksandar

    2009-01-01

    This paper presents the basic properties of chromatic derivatives and chromatic expansions and provides an appropriate motivation for introducing these notions. Chromatic derivatives are special, numerically robust linear differential operators which correspond to certain families of orthogonal polynomials. Chromatic expansions are series of the corresponding special functions, which possess the best features of both the Taylor and the Shannon expansions. This makes chromatic derivatives and ...

  17. Development of a Probabilistic Technique for On-line Parameter and State Estimation in Non-linear Dynamic Systems

    International Nuclear Information System (INIS)

    Tunc Aldemir; Miller, Don W.; Hajek, Brian K.; Peng Wang

    2002-01-01

    The DSD (Dynamic System Doctor) is a system-independent, interactive software under development for on-line state/parameter estimation in dynamic systems (1), partially supported through a Nuclear Engineering Education (NEER) grant during 1998-2001. This paper summarizes the recent accomplishments in improving the user-friendliness and computational capability of DSD

  18. Chromatic correction for the final transport system

    International Nuclear Information System (INIS)

    Brown, K.L.; Peterson, J.M.

    1980-01-01

    The final transport and focusing of the heavy-ion beam onto the fusion pellet in vacuum is complicated by several non-linear effects - namely, chromatic (momentum dependent) effects, geometric aberrations, and space-charge forces. This paper gives an example of how the chromatic effects can be nullified, at least to second order. Whether third- or higher-order terms are important is not yet clear. Space-charge effects are important but are not considered here

  19. A methodology for on-line calculation of temperature and thermal stress under non-linear boundary conditions

    International Nuclear Information System (INIS)

    Botto, D.; Zucca, S.; Gola, M.M.

    2003-01-01

    In the literature many works have been written dealing with the task of on-line calculation of temperature and thermal stress for machine components and structures, in order to evaluate fatigue damage accumulation and estimate residual life. One of the most widespread methodologies is the Green's function technique (GFT), by which machine parameters such as fluid temperatures, pressures and flow rates are converted into metal temperature transients and thermal stresses. However, since the GFT is based upon the linear superposition principle, it cannot be directly used in the case of varying heat transfer coefficients. In the present work, a different methodology is proposed, based upon CMS for temperature transient calculation and upon the GFT for the related thermal stress evaluation. This new approach allows variable heat transfer coefficients to be accounted for. The methodology is applied for two different case studies, taken from the literature: a thick pipe and a nozzle connected to a spherical head, both subjected to multiple convective boundary conditions

  20. On-line scheme for parameter estimation of nonlinear lithium ion battery equivalent circuit models using the simplified refined instrumental variable method for a modified Wiener continuous-time model

    International Nuclear Information System (INIS)

    Allafi, Walid; Uddin, Kotub; Zhang, Cheng; Mazuir Raja Ahsan Sha, Raja; Marco, James

    2017-01-01

    Highlights: •Off-line estimation approach for continuous-time domain for non-invertible function. •Model reformulated to multi-input-single-output; nonlinearity described by sigmoid. •Method directly estimates parameters of nonlinear ECM from the measured-data. •Iterative on-line technique leads to smoother convergence. •The model is validated off-line and on-line using NCA battery. -- Abstract: The accuracy of identifying the parameters of models describing lithium ion batteries (LIBs) in typical battery management system (BMS) applications is critical to the estimation of key states such as the state of charge (SoC) and state of health (SoH). In applications such as electric vehicles (EVs) where LIBs are subjected to highly demanding cycles of operation and varying environmental conditions leading to non-trivial interactions of ageing stress factors, this identification is more challenging. This paper proposes an algorithm that directly estimates the parameters of a nonlinear battery model from measured input and output data in the continuous time-domain. The simplified refined instrumental variable method is extended to estimate the parameters of a Wiener model where there is no requirement for the nonlinear function to be invertible. To account for nonlinear battery dynamics, in this paper, the typical linear equivalent circuit model (ECM) is enhanced by a block-oriented Wiener configuration where the nonlinear memoryless block following the typical ECM is defined to be a sigmoid static nonlinearity. The nonlinear Weiner model is reformulated in the form of a multi-input, single-output linear model. This linear form allows the parameters of the nonlinear model to be estimated using any linear estimator such as the well-established least squares (LS) algorithm. In this paper, the recursive least square (RLS) method is adopted for online parameter estimation. The approach was validated on experimental data measured from an 18650-type Graphite

  1. Nonlinear dynamics in Nuclotron

    International Nuclear Information System (INIS)

    Dinev, D.

    1997-01-01

    The paper represents an extensive study of the nonlinear beam dynamics in the Nuclotron. Chromatic effects, including the dependence of the betatron tunes on the amplitude, and chromatic perturbations have been investigated taking into account the measured field imperfections. Beam distortion, smear, dynamic aperture and nonlinear acceptance have been calculated for different particle energies and betatron tunes

  2. Chromatic polynomials for simplicial complexes

    DEFF Research Database (Denmark)

    Møller, Jesper Michael; Nord, Gesche

    2016-01-01

    In this note we consider s s -chromatic polynomials for finite simplicial complexes. When s=1 s=1 , the 1 1 -chromatic polynomial is just the usual graph chromatic polynomial of the 1 1 -skeleton. In general, the s s -chromatic polynomial depends on the s s -skeleton and its value at r...

  3. Analysis of second order harmonic distortion due to transmitter non-linearity and chromatic and modal dispersion of optical OFDM SSB modulated signals in SMF-MMF fiber links

    Science.gov (United States)

    Patel, Dhananjay; Singh, Vinay Kumar; Dalal, U. D.

    2017-01-01

    Single mode fibers (SMF) are typically used in Wide Area Networks (WAN), Metropolitan Area Networks (MAN) and also find applications in Radio over Fiber (RoF) architectures supporting data transmission in Fiber to the Home (FTTH), Remote Antenna Units (RAUs), in-building networks etc. Multi-mode fibers (MMFs) with low cost, ease of installation and low maintenance are predominantly (85-90%) deployed in-building networks providing data access in local area networks (LANs). The transmission of millimeter wave signals through the SMF in WAN and MAN, along with the reuse of MMF in-building networks will not levy fiber reinstallation cost. The transmission of the millimeter waves experiences signal impairments due to the transmitter non-linearity and modal dispersion of the MMF. The MMF exhibiting large modal dispersion limits the bandwidth-length product of the fiber. The second and higher-order harmonics present in the optical signal fall within the system bandwidth. This causes degradation in the received signal and an unwanted radiation of power at the RAU. The power of these harmonics is proportional to the non-linearity of the transmitter and the modal dispersion of the MMF and should be maintained below the standard values as per the international norms. In this paper, a mathematical model is developed for Second-order Harmonic Distortion (HD2) generated due to non-linearity of the transmitter and chromatic-modal dispersion of the SMF-MMF optic link. This is also verified using a software simulation. The model consists of a Mach Zehnder Modulator (MZM) that generates two m-QAM OFDM Single Sideband (SSB) signals based on phase shift of the hybrid coupler (90° and 120°). Our results show that the SSB signal with 120° hybrid coupler has suppresses the higher-order harmonics and makes the system more robust against the HD2 in the SMF-MMF optic link.

  4. Symplectic maps and chromatic optics in particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yunhai

    2015-10-11

    We have applied the nonlinear map method to comprehensively characterize the chromatic optics in particle accelerators. Our approach is built on the foundation of symplectic transfer maps of magnetic elements. The chromatic lattice parameters can be transported from one element to another by the maps. We introduce a Jacobian operator that provides an intrinsic linkage between the maps and the matrix with parameter dependence. The link allows us to directly apply the formulation of the linear optics to compute the chromatic lattice parameters. As an illustration, we analyze an alternating-gradient cell with nonlinear sextupoles, octupoles, and decapoles and derive analytically their settings for the local chromatic compensation. As a result, the cell becomes nearly perfect up to the third-order of the momentum deviation.

  5. Genetic algorithm for chromaticity correction in diffraction limited storage rings

    Directory of Open Access Journals (Sweden)

    M. P. Ehrlichman

    2016-04-01

    Full Text Available A multiobjective genetic algorithm is developed for optimizing nonlinearities in diffraction limited storage rings. This algorithm determines sextupole and octupole strengths for chromaticity correction that deliver optimized dynamic aperture and beam lifetime. The algorithm makes use of dominance constraints to breed desirable properties into the early generations. The momentum aperture is optimized indirectly by constraining the chromatic tune footprint and optimizing the off-energy dynamic aperture. The result is an effective and computationally efficient technique for correcting chromaticity in a storage ring while maintaining optimal dynamic aperture and beam lifetime.

  6. Chromatic analysis and possible local chromatic correction in RHIC

    International Nuclear Information System (INIS)

    Luo, Y.; Fischer, W.; Gu, X.; Trbojevic, D.

    2011-01-01

    In this article we will answer the following questions for the RHIC polarized proton (p-p) and Au-Au run lattices: (1) what are the sources of second order chromaticities? (2) what is the dependence of second order chromaticity on the on-momentum β-beat? (3) what is the dependence of second order chromaticity on β* at IP6 and IP8? To answer these questions, we use the perturbation theory to numerically calculate the contributions of each quadrupole and sextupole to the first, second, and third order chromaticities. Possible local methods to reduce chromatic effects in RHIC ring are shortly discussed.

  7. Chromatic graph theory

    CERN Document Server

    Chartrand, Gary; Rosen, Kenneth H

    2008-01-01

    Beginning with the origin of the four color problem in 1852, the field of graph colorings has developed into one of the most popular areas of graph theory. Introducing graph theory with a coloring theme, Chromatic Graph Theory explores connections between major topics in graph theory and graph colorings as well as emerging topics. This self-contained book first presents various fundamentals of graph theory that lie outside of graph colorings, including basic terminology and results, trees and connectivity, Eulerian and Hamiltonian graphs, matchings and factorizations, and graph embeddings. The remainder of the text deals exclusively with graph colorings. It covers vertex colorings and bounds for the chromatic number, vertex colorings of graphs embedded on surfaces, and a variety of restricted vertex colorings. The authors also describe edge colorings, monochromatic and rainbow edge colorings, complete vertex colorings, several distinguishing vertex and edge colorings, and many distance-related vertex coloring...

  8. Chromates (3) and chromates (5) of rare earths

    International Nuclear Information System (INIS)

    Suponitskij, Yu.L.

    1986-01-01

    Data on preparation methods, structure and properties of chromates (3, 5) and mixed chromates (3) of rare earths, scandium and yttrium are generalized. Phase diagrams of systems Ln 2 O 3 -Cr 2 O 3 (Ln - rare earths, Sc, Y), chemical and thermodynamic properties of chromates (3, 5), their crystal structure and character of thermal decomposition are considered. Application fields of the compounds mentioned are suggested

  9. PSB Chromaticity Correction in both Planes

    CERN Document Server

    Bartosik, Hannes; CERN. Geneva. ATS Department

    2017-01-01

    In view of the LHC injector upgrade program (LIU[1]), all LHC pre-accelerators and in particular the CERN Booster (PSB) are being reviewed for potential lattice optics and equipment optimizations. The option to correct the chromaticity in both planes would be very helpful for a better control of the beam in the presence of both non-linearities and space charge. Moreover, one could reduce decoherence phenomena that otherwise limit the usefulness of resonance measurement techniques based on a turn-by-turn BPM system.

  10. Calcium chromate process related investigations

    International Nuclear Information System (INIS)

    Dillard, B.M.

    1979-01-01

    A pilot plant for production of calcium chromate has been scaled up to a small production facility at the General Electric Neutron Devices Department. In preparation for this scale-up, the process and final product were studied in order to evaluate problems not considered previously. The variables and processes studied included: (1) the determination of optimum drying temperature and time for product analysis; (2) the effect of the grade of lime used as the precipitating agent on the purity of the calcium chromate; (3) product purity when calcium chromate is precipitated by the addition of ammonium chromate to slaked lime; (4) the reagents best suited for cleaning calcium chromate spills; and (5) methods for determining hydroxide ion concentration in calcium chromate. The optimum drying time for the product before analysis is four hours at 600 0 C. Gases evolved at various temperatures during the drying process were carbon dioxide and water vapor. Technical grade lime produced calcium chromate of the highest purity. Both nitric and acetic acids were efficient dissolvers of calcium chromate spills. Direct titration of hydroxide ion with sulfuric acid gave an average recovery of 93% for samples spiked with calcium hydroxide. 1 figure, 17 tables

  11. Camera processing with chromatic aberration.

    Science.gov (United States)

    Korneliussen, Jan Tore; Hirakawa, Keigo

    2014-10-01

    Since the refractive index of materials commonly used for lens depends on the wavelengths of light, practical camera optics fail to converge light to a single point on an image plane. Known as chromatic aberration, this phenomenon distorts image details by introducing magnification error, defocus blur, and color fringes. Though achromatic and apochromatic lens designs reduce chromatic aberration to a degree, they are complex and expensive and they do not offer a perfect correction. In this paper, we propose a new postcapture processing scheme designed to overcome these problems computationally. Specifically, the proposed solution is comprised of chromatic aberration-tolerant demosaicking algorithm and post-demosaicking chromatic aberration correction. Experiments with simulated and real sensor data verify that the chromatic aberration is effectively corrected.

  12. Roots of the Chromatic Polynomial

    DEFF Research Database (Denmark)

    Perrett, Thomas

    The chromatic polynomial of a graph G is a univariate polynomial whose evaluation at any positive integer q enumerates the proper q-colourings of G. It was introduced in connection with the famous four colour theorem but has recently found other applications in the field of statistical physics...... extend Thomassen’s technique to the Tutte polynomial and as a consequence, deduce a density result for roots of the Tutte polynomial. This partially answers a conjecture of Jackson and Sokal. Finally, we refocus our attention on the chromatic polynomial and investigate the density of chromatic roots...

  13. A linear chromatic mechanism drives the pupillary response.

    Science.gov (United States)

    Tsujimura, S.; Wolffsohn, J. S.; Gilmartin, B.

    2001-01-01

    Previous studies have shown that a chromatic mechanism can drive pupil responses. The aim of this research was to clarify whether a linear or nonlinear chromatic mechanism drives pupillary responses by using test stimuli of various colours that are defined in cone contrast space. The pupil and accommodation responses evoked by these test stimuli were continuously and simultaneously objectively measured by photorefraction. The results with isochromatic and isoluminant stimuli showed that the accommodative level remained approximately constant (< 0.25 D change in mean level) even when the concurrent pupillary response was large (ca. 0.30 mm). The pupillary response to an isoluminant grating was sustained, delayed (by ca. 60 ms) and larger in amplitude than that for a isochromatic uniform stimulus, which supports previous work suggesting that the chromatic mechanism contributes to the pupillary response. In a second experiment, selected chromatic test gratings were used and isoresponse contours in cone contrast space were obtained. The results showed that the isoresponse contour in cone contrast space is well described (r(2) = 0.99) by a straight line with a positive slope. The results indicate that a /L - M/ linear chromatic mechanism, whereby a signal from the long wavelength cone is subtracted from that of the middle wavelength cone and vice versa, drives pupillary responses. PMID:11674867

  14. Chromatic monitoring of dc plasma torches: The latest developments

    Czech Academy of Sciences Publication Activity Database

    Djakov, B. E.; Enikov, R.; Oliver, D.H.; Hrabovský, Milan; Kopecký, Vladimír

    2006-01-01

    Roč. 3, č. 2 (2006), s. 170-173 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GA202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Keywords : chromatic monitoring * on-line control * plasma jet * plasma torch * powder Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.298, year: 2006

  15. On chromatic and geometrical calibration

    DEFF Research Database (Denmark)

    Folm-Hansen, Jørgen

    1999-01-01

    The main subject of the present thesis is different methods for the geometrical and chromatic calibration of cameras in various environments. For the monochromatic issues of the calibration we present the acquisition of monochrome images, the classic monochrome aberrations and the various sources...... the correct interpolation method is described. For the chromatic issues of calibration we present the acquisition of colour and multi-spectral images, the chromatic aberrations and the various lens/camera based non-uniformities of the illumination of the image plane. It is described how the monochromatic...... to design calibration targets for both geometrical and chromatic calibration are described. We present some possible systematical errors on the detection of the objects in the calibration targets, if viewed in a non orthogonal angle, if the intensities are uneven or if the image blurring is uneven. Finally...

  16. Exploring a Chromatic Oblique Effect

    National Research Council Canada - National Science Library

    Curran, Paul

    1997-01-01

    .... The purpose of this thesis was to investigate the role of certain spatial, temporal, and chromatic features on the human visual system and how these features may aid the quest for better camouflage. Methods...

  17. Chromatic polynomials of random graphs

    International Nuclear Information System (INIS)

    Van Bussel, Frank; Fliegner, Denny; Timme, Marc; Ehrlich, Christoph; Stolzenberg, Sebastian

    2010-01-01

    Chromatic polynomials and related graph invariants are central objects in both graph theory and statistical physics. Computational difficulties, however, have so far restricted studies of such polynomials to graphs that were either very small, very sparse or highly structured. Recent algorithmic advances (Timme et al 2009 New J. Phys. 11 023001) now make it possible to compute chromatic polynomials for moderately sized graphs of arbitrary structure and number of edges. Here we present chromatic polynomials of ensembles of random graphs with up to 30 vertices, over the entire range of edge density. We specifically focus on the locations of the zeros of the polynomial in the complex plane. The results indicate that the chromatic zeros of random graphs have a very consistent layout. In particular, the crossing point, the point at which the chromatic zeros with non-zero imaginary part approach the real axis, scales linearly with the average degree over most of the density range. While the scaling laws obtained are purely empirical, if they continue to hold in general there are significant implications: the crossing points of chromatic zeros in the thermodynamic limit separate systems with zero ground state entropy from systems with positive ground state entropy, the latter an exception to the third law of thermodynamics.

  18. Chromatic interocular-switch rivalry.

    Science.gov (United States)

    Christiansen, Jens H; D'Antona, Anthony D; Shevell, Steven K

    2017-05-01

    Interocular-switch rivalry (also known as stimulus rivalry) is a kind of binocular rivalry in which two rivalrous images are swapped between the eyes several times a second. The result is stable periods of one image and then the other, with stable intervals that span many eye swaps (Logothetis, Leopold, & Sheinberg, 1996). Previous work used this close kin of binocular rivalry with rivalrous forms. Experiments here test whether chromatic interocular-switch rivalry, in which the swapped stimuli differ in only chromaticity, results in slow alternation between two colors. Swapping equiluminant rivalrous chromaticities at 3.75 Hz resulted in slow perceptual color alternation, with one or the other color often continuously visible for two seconds or longer (during which there were 15+ eye swaps). A well-known theory for sustained percepts from interocular-switch rivalry with form is inhibitory competition between binocular neurons driven by monocular neurons with matched orientation tuning in each eye; such binocular neurons would produce a stable response when a given orientation is swapped between the eyes. A similar model can account for the percepts here from chromatic interocular-switch rivalry and is underpinned by the neurophysiological finding that color-preferring binocular neurons are driven by monocular neurons from each eye with well-matched chromatic selectivity (Peirce, Solomon, Forte, & Lennie, 2008). In contrast to chromatic interocular-switch rivalry, luminance interocular-switch rivalry with swapped stimuli that differ in only luminance did not result in slowly alternating percepts of different brightnesses.

  19. Optimizing Chromatic Coupling Measurement in the LHC

    CERN Document Server

    Persson, Tobias

    2016-01-01

    Optimizing chromatic coupling measurement in the LHC Chromatic coupling introduces a dependency of transverse coupling with energy. LHC is equipped with skew sextupoles to compensate the possible adverse effects of chromatic coupling. In 2012 a beam-based correction was calculated and applied successfully for the fist time. However, the method used to reconstruct the chromatic coupling was dependent on stable tunes and equal chromaticities between the horizontal and vertical planes. In this article an improved method to calculate the chromatic coupling without these constraints is presented.

  20. Chromatic effects in the superconducting accelerator NUCLOTRON

    International Nuclear Information System (INIS)

    Dinev, D.

    1998-01-01

    A systematic study of the chromatic effects in the superconducting heavy ion synchrotron NUCLOTRON in the JINR, Dubna has been performed. The natural chromaticity has been evaluated taking into account the effect of the dipole magnets. The impact of the systematic and random imperfections in the magnetic field of dipoles on the chromaticity and the dependence of the betatron tunes on the amplitude of oscillations have been investigated. The strengths of the sextupole corrections necessary to cancel the chromaticity have been calculated. The chromatic perturbations have been studied by the means of the Montague chromatic functions (author)

  1. Source of second order chromaticity in RHIC

    International Nuclear Information System (INIS)

    Luo, Y.; Gu, X.; Fischer, W.; Trbojevic, D.

    2011-01-01

    In this note we will answer the following questions: (1) what is the source of second order chromaticities in RHIC? (2) what is the dependence of second order chromaticity on the on-momentum β-beat? (3) what is the dependence of second order chromaticity on β* at IP6 and IP8? To answer these questions, we use the perturbation theory to numerically calculate the contributions of each quadrupole and sextupole to the first, second, and third order chromaticities.

  2. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  3. Solubility of chromate in a hydrated OPC

    International Nuclear Information System (INIS)

    Leisinger, Sabine M.; Bhatnagar, Amit; Lothenbach, Barbara; Johnson, C. Annette

    2014-01-01

    Highlights: • Solid solutions exist between gypsum and calcium chromate. • The cementitious matrix can bind chromate concentrations up to 0.1 mol/kg. • The chromate binding phase in the cementitious matrix is CrO 4 -ettringite. - Abstract: The knowledge of the chromate binding mechanisms is essential for the prediction of the long-term leachability of cement-based solidified waste containing increased chromate concentrations because of its toxicity and high mobility. In this paper pore water concentrations from OPC doped with varying CaCrO 4 concentrations (0.01–0.8 mol/kg), equilibrated for 28 days were reported. It could be shown that the cementitious matrix can bind chromate concentrations up to 0.1 mol/kg and that the chromate solubility limiting phase was CrO 4 -ettringite, while chromate containing AFm (monochromate) was unstable. Comparison with thermodynamic modelling indicated that at lower chromate dosages chromate was mainly bound by CrO 4 -ettringite while at very high dosages also a mixed CaCrO 4 –CaSO 4 ·2H 2 O phase precipitated. Additional experiments indicated a solubility product of 10 −3.66 for CaCrO 4 and verified the solid solution formation with CaSO 4 ·2H 2 O. Leaching tests indicated a strong chromate binding mainly in the pH range 10.5–13.5, while at pH < 10 very little chromate was bound as ettringite, monocarbonate and C–S–H phases were destabilized. Generally the thermodynamic modeling underestimated chromate uptake indicating that an additional chromate binding possibly on C–S–H or on mixed chromate–carbonate–hydroxide AFm phases

  4. Sextupole correction for a ring with large chromaticity and the influence of magnetic errors on its parameters

    International Nuclear Information System (INIS)

    Kamiya, Y.; Katoh, M.; Honjo, I.

    1987-01-01

    A future ring with a low emittance and large circumference, specifically dedicated to a synchrotron light source, will have a large chromaticity, so that it is important to employ a sophisticated sextupole correction as well as the design of linear lattice to obtain the stable beam. The authors tried a method of sextupole correction for a lattice with a large chromaticity and small dispersion function. In such a lattice the sextupole magnets are obliged to become large in strength to compensate the chromaticity. Then the nonlinear effects of the sextupole magnets will become more serious than their chromatic effects. Furthermore, a ring with strong quadrupole magnets to get a very small emittance and with strong sextupole magnets to compensate the generated chromaticity will be very sensitive to their magnetic errors. The authors also present simple formulae to evaluate the effects on the beam parameters. The details will appear in a KEK Report

  5. Bacterial chromate reduction and product characterization

    International Nuclear Information System (INIS)

    Mehlhorn, R.J.; Buchanan, B.B.; Leighton, T.

    1992-11-01

    Bacillus subtilis reduced hexavalent chromate to trivalent chromium under either aerobic or anaerobic conditions. Reduction of CR(VI) and appearance of extracellular Cr(III) were demonstrated by electron spin resonance and spectrophotometry. Chromate reduction was stimulated more than five-fold by freeze-thawing, indicating that intracellular reductases or chemical reductants reduce chromate more rapidly than do intact cells. Moderately concentrated cells (10% pellet volume after centrifugation) reduced approximately 40 μM chromate/min (2 mg Cr/1-min) when exposed to 100 μM chromate (5 mg Cr/1). Highly concentrated cells (70% pellet volume) reduced more than 99.8% of 2 mM chromate (100 mg Cr/1) within 15 min. This rate of chromate reduction was of the same order of magnitude as the rate of respiration in aerobic cells. A substantial fraction of the reduction product (ca. 75%) was extracellular Cr(M), which could readily be separated from the cells by centrifugation. At high chromate concentrations, some fraction of reduced CR(VI) appeared to be taken up by cells, consistent with a detection of intracellular paramagnetic products. At low chromate concentrations, undefined growth medium alone reduced Cr(VI), but at a slow rate, relative to cells. Under appropriate conditions, B. subtilis appears to be an organism of choice for detoxifying chromate-contaminated soil and water

  6. Semantics of color in chromatism

    Science.gov (United States)

    Serov, Nikolai V.

    2002-06-01

    The aim of this investigation is to describe the semantics of color in chromatism (from the ancient Greek triune notion of >: (1) color as ideal (Id- plan), psychic; (2) tint as physical, verbal; material (M- plan), physiological, syntonic (S-plan), and (3) emotion as their informative-energetic correlation). Being a new field of science, chromatism links humanitarian and natural subjects by means of interdiscipline investigation of a real (f-m) man living in a real (color) surrounding environment. According to the definition for >, color may be considered to be the most universal notion, permitting to assume the unity of both a man and an environment. Due to this assumption, we may give models of human intellect.

  7. Chromaticity correction for the SSC collider rings

    International Nuclear Information System (INIS)

    Sen, T.; Nosochkov, Y.; Pilat, F.; Stiening, R.; Ritson, D.M.

    1993-01-01

    The authors address the issue of correcting higher order chromaticities of the collider with one or more low β insertions. The chromaticity contributed by the interaction regions (IRs) depends crucially on the maximum value of β in the two IRs in a cluster, the phase advance between adjacent interaction points (IPs), and the choice of global tune. They propose a correction scheme in which the linear chromaticity is corrected by a global distribution of sextupoles and the second order chromaticity of each IR is corrected by a more local set of sextupoles. Compared to the case where only the linear chromaticity is corrected, this configuration increases the momentum aperture more than three times and also reduces the β beat by this factor. With this scheme, the tune can be chosen to satisfy other constraints and the two IRs in a cluster can be operated independently at different luminosities without affecting the chromatic properties of the ring

  8. Chromaticity correction for the SSC Collider Rings

    International Nuclear Information System (INIS)

    Sen, T.; Nosochkov, Y.; Pilat, F.; Stiening, R.; Ritson, D.M.

    1993-05-01

    We address the issue of correcting higher order chromaticities of the collider with one or more low β insertions. The chromaticity contributed by the interaction regions (IRS) depends crucially on the maximum value of β in the two IRs in a cluster, the phase advance between adjacent interaction points (IPs), and the choice of global tune. We propose a correction scheme in which the linear chromaticity is corrected by a global distribution of sextupoles and the second order chromaticity of each IR is corrected by a more local set of sextupoles. Compared to the case where only the linear chromaticity is corrected, this configuration increases the momentum aperture more than three times and also reduces the β beat by this factor. With this scheme, the tune can be chosen to satisfy other constraints and the two IRs in a cluster can be operated independently at different luminosities without affecting the chromatic properties of the ring

  9. Does the chromatic Mach bands effect exist?

    Science.gov (United States)

    Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

    2009-06-30

    The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

  10. Chromaticity tracking using a phase modulation technique

    International Nuclear Information System (INIS)

    Tan, C.Y.; Fermilab

    2007-01-01

    In the classical chromaticity measurement technique, chromaticity is measured by measuring the change in betatron tune as the RF frequency is varied. This paper will describe a novel way of measuring chromaticity: we will phase modulate the RF with a known sine wave and then phase demodulate the betatron frequency. The result is a line in Fourier space which corresponds to the frequency of our sine wave modulation. The peak of this sine wave is proportional to chromaticity. For this technique to work, a tune tracker PLL system is required because it supplies the betatron carrier frequency. This method has been tested in the Tevatron and we will show the results here

  11. Comparison of CIE chromaticity values

    CSIR Research Space (South Africa)

    Van Tonder, N

    1999-02-02

    Full Text Available matter #1999 Elsevier Science B.V. All rights reserved. PII: S0003-2670(98)00526-1 an opal glass white standard. Furthermore, the x and y CIE chromaticity values had to be calculated under the conditions of illuminants A, C and D65 with a 28 observer. 2... to the South African national measuring standards of light by an opal glass re?ectance standard (NPL calibration number AU87) calibrated by the National Physical Laboratory, UK (NPL). Re?ectance measurements were taken at three different positions on each...

  12. Skew chromaticity in large accelerators

    International Nuclear Information System (INIS)

    Peggs, S.; Dell, G.F.

    1995-01-01

    The 2-D ''skew chromaticity'' vector k is introduced when the standard on-momentum description of linear coupling is extended to include off-momentum particles. A lattice that is well decoupled on-momentum may be badly decoupled off-momentum, inside the natural momentum spread of the beam. There are two general areas of concern: (1) the free space in the tune plane is decreased; (2) collective phenomena may be destabilized. Two strong new criteria for head-tail stability in the presence of off-momentum coupling are derived, which are consistent with experimental and operational observations at the Tevatron, and with tracking data from RHIC

  13. On-line filtering

    International Nuclear Information System (INIS)

    Verkerk, C.

    1978-01-01

    Present day electronic detectors used in high energy physics make it possible to obtain high event rates and it is likely that future experiments will face even higher data rates than at present. The complexity of the apparatus increases very rapidly with time and also the criteria for selecting desired events become more and more complex. So complex in fact that the fast trigger system cannot be designed to fully cope with it. The interesting events become thus contaminated with multitudes of uninteresting ones. To distinguish the 'good' events from the often overwhelming background of other events one has to resort to computing techniques. Normally this selection is made in the first part of the analysis of the events, analysis normally performed on a powerful scientific computer. This implies however that many uninteresting or background events have to be recorded during the experiment for subsequent analysis. A number of undesired consequences result; and these constitute a sufficient reason for trying to perform the selection at an earlier stage, in fact ideally before the events are recorded on magnetic tape. This early selection is called 'on-line filtering' and it is the topic of the present lectures. (Auth.)

  14. Connections between the matching and chromatic polynomials

    Directory of Open Access Journals (Sweden)

    E. J. Farrell

    1992-01-01

    Full Text Available The main results established are (i a connection between the matching and chromatic polynomials and (ii a formula for the matching polynomial of a general complement of a subgraph of a graph. Some deductions on matching and chromatic equivalence and uniqueness are made.

  15. Game chromatic number of lexicographic product graphs

    Directory of Open Access Journals (Sweden)

    R. Alagammai

    2015-11-01

    Full Text Available In this paper, we determine the exact values of the game chromatic number of lexicographic product of path P2 with path Pn, star K1,n and wheel Wn. Also we give an upper bound for the game chromatic number of lexicographic product of any two simple graphs G and H.

  16. On line portal imaging

    International Nuclear Information System (INIS)

    Munro, Peter

    1997-01-01

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging, describe some of the image registration methods that have been developed to determine geometric errors quantitatively, and discuss how portal imaging has been incorporated into clinical practice. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices include T.V. camera-based systems, liquid ionisation chamber systems, and shortly, flat panel systems. The characteristics of these imaging systems will be discussed. In addition, other approaches such as the use of kilovoltage x-ray sources, video monitoring, and ultrasound have been proposed for improving patient positioning. Some of the advantages of these approaches will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. One problem is finding a common frame of reference for the simulator and portal images, since the location of the radiation field within the pixel matrix may differ for the two images. As a result, a common frame of reference has to be established before the anatomic structures in the images can be registered - generally by registering radiation field edges identified in the simulator and portal images. In addition, distortions in patient geometry or rotations out of the image plane can confound the image registration techniques. Despite the

  17. On line portal imaging

    International Nuclear Information System (INIS)

    Munro, Peter

    1996-01-01

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine geometric errors quantitatively; discuss some of the ways that portal imaging has been incorporated into routine clinical practice; describe quality assurance procedures for these devices, and discuss the use of portal imaging devices for dosimetry applications. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. However, the task is not nearly as straight-forward as it sounds. One problem

  18. Corrosion in artificial defects. II. Chromate reactions

    International Nuclear Information System (INIS)

    Furman, S.A.; Scholes, F.H.; Hughes, A.E.; Jamieson, D.N.; Macrae, C.M.; Glenn, A.M.

    2006-01-01

    Artificial defects, in the form of slots, were milled through a chromate-containing protective paint system on AA2024-T3 and exposed to neutral salt spray (NSS). Proton induced X-ray emission (PIXE), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS), electron microprobe analysis (EMPA), and Raman spectroscopy were used to characterise the primer and the alloy surface. Chromate was released by the primer to form a 40 μm depletion zone around the edge of the slot. Within the depletion zone, the chromate was reduced but not completely removed. Chromate was detected in the runoff from the slots and was also found to have reacted with the exposed alloy surface. Chromate was found to react with intermetallic particles, smears formed by the milling process, and pits

  19. CHROMAT trademark Version 1.1--Soil Chromium Attenuation Evaluation Model

    International Nuclear Information System (INIS)

    Felmy, A.R.; Rai, D.; Zachara, J.M.; Thapa, M.; Gold, M.

    1992-07-01

    This document is the user's manual and technical reference for the Soil Chromium Attenuation Model (CHROMAT trademark), a computer code designed to calculate both the dissolved Cr concentration and the amount of Cr attenuated in soils as a result of the geochemical reactions that occur as Cr-containing leachates migrate through porous soils. The dissolved Cr concentration and the amount of Cr attenuated are calculated using thermodynamic (mechanistic) data for aqueous complexation reactions, adsorption/ desorption reactions, and precipitation/dissolution reactions involving both CR(III) and Cr(VI) species. Use of this mechanistic approach means that CHROMAT trademark requires a minimum amount of site-specific data on leachate and soil characteristics. CHROMAT trademark is distributed in executable form for IBM and IBM-compatible personal computers through a license from the Electric Power Research Institute (EPRI). The user interacts with CHROMAT trademark using menu-driven screen displays. Interactive on-line help options are available. Output from the code can be obtained in tabular or graphic form. This manual describes the development of CHROMAT trademark, including experimental data development in support of the model and model validation studies. The thermodynamic data and computational algorithm are also described. Example problems and results are included

  20. On-line determination of anions in pulp mills by capillary electrophoresis (CE); Tehdasoloissa tapahtuva anionien kapillaarielektroforeettinen on-line maeaeritys ja sen hyoedyntaeminen prosessivalvonnassa - MPKY 02

    Energy Technology Data Exchange (ETDEWEB)

    Kokkonen, R; Holmberg, M; Vainikka, V [Finnish Pulp and Paper Research Institute, Espoo (Finland)

    1999-12-31

    The aim of the study was to set-up a process control system for on-line measurement of certain anions. Typical anions which forms precipitates in pulp and paper mills are oxalate, carbonate and sulphate. Thus it is important to develop a continuous process analyzing system to control concentration levels of this anions. For the preliminary tests of continuous determinations of chloride and sulphate anions in tap water a simple on-line system was build in KCL (The Finnish Pulp and Paper Research Institute) and connected to a capillary electroforesis apparatus. In the preliminary tests a chromate buffer (ph = 7.6) was used. Separation of chloride and sulphate was excellent but the stability of buffer was not good enough and it was usable only for few hours. After experimental studies VTT developed a stable capillary electrophoresis method based on mixed amine buffer and this was selected for an on-line method for determination of anions in process waters of the pulp and paper industry. In the preliminary on-line test (r = 20) repeatabilities of migration times of sulphate and chloride with the chromate buffer were < 5 % (RSD) and peak heights < 15 % (RSD). With the mixed amine buffer repeatabilities were better. The preliminary tests showed that it is possible to connect a capillary electrophoresis system to on-line measurements. For the moment no commercial on-line CE apparatus is available. (orig.)

  1. On-line determination of anions in pulp mills by capillary electrophoresis (CE); Tehdasoloissa tapahtuva anionien kapillaarielektroforeettinen on-line maeaeritys ja sen hyoedyntaeminen prosessivalvonnassa - MPKY 02

    Energy Technology Data Exchange (ETDEWEB)

    Kokkonen, R.; Holmberg, M.; Vainikka, V. [Finnish Pulp and Paper Research Institute, Espoo (Finland)

    1998-12-31

    The aim of the study was to set-up a process control system for on-line measurement of certain anions. Typical anions which forms precipitates in pulp and paper mills are oxalate, carbonate and sulphate. Thus it is important to develop a continuous process analyzing system to control concentration levels of this anions. For the preliminary tests of continuous determinations of chloride and sulphate anions in tap water a simple on-line system was build in KCL (The Finnish Pulp and Paper Research Institute) and connected to a capillary electroforesis apparatus. In the preliminary tests a chromate buffer (ph = 7.6) was used. Separation of chloride and sulphate was excellent but the stability of buffer was not good enough and it was usable only for few hours. After experimental studies VTT developed a stable capillary electrophoresis method based on mixed amine buffer and this was selected for an on-line method for determination of anions in process waters of the pulp and paper industry. In the preliminary on-line test (r = 20) repeatabilities of migration times of sulphate and chloride with the chromate buffer were < 5 % (RSD) and peak heights < 15 % (RSD). With the mixed amine buffer repeatabilities were better. The preliminary tests showed that it is possible to connect a capillary electrophoresis system to on-line measurements. For the moment no commercial on-line CE apparatus is available. (orig.)

  2. On line portal imaging

    International Nuclear Information System (INIS)

    Munro, Peter

    1995-01-01

    Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

  3. COMPARISON OF NONLINEAR DYNAMICS OPTIMIZATION METHODS FOR APS-U

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.; Borland, Michael

    2017-06-25

    Many different objectives and genetic algorithms have been proposed for storage ring nonlinear dynamics performance optimization. These optimization objectives include nonlinear chromaticities and driving/detuning terms, on-momentum and off-momentum dynamic acceptance, chromatic detuning, local momentum acceptance, variation of transverse invariant, Touschek lifetime, etc. In this paper, the effectiveness of several different optimization methods and objectives are compared for the nonlinear beam dynamics optimization of the Advanced Photon Source upgrade (APS-U) lattice. The optimized solutions from these different methods are preliminarily compared in terms of the dynamic acceptance, local momentum acceptance, chromatic detuning, and other performance measures.

  4. Pursuit Latency for Chromatic Targets

    Science.gov (United States)

    Mulligan, Jeffrey B.; Ellis, Stephen R. (Technical Monitor)

    1998-01-01

    The temporal dynamics of eye movement response to a change in direction of stimulus motion has been used to compare the processing speeds of different types of stimuli (Mulligan, ARVO '97). In this study, the pursuit response to colored targets was measured to test the hypothesis that the slow response of the chromatic system (as measured using traditional temporal sensitivity measures such as contrast sensitivity) results in increased eye movement latencies. Subjects viewed a small (0.4 deg) Gaussian spot which moved downward at a speed of 6.6 deg/sec. At a variable time during the trajectory, the dot's direction of motion changed by 30 degrees, either to the right or left. Subjects were instructed to pursue the spot. Eye movements were measured using a video ophthalmoscope with an angular resolution of approximately 1 arc min and a temporal sampling rate of 60 Hz. Stimuli were modulated in chrominance for a variety of hue directions, combined with a range of small luminance increments and decrements, to insure that some of the stimuli fell in the subjects' equiluminance planes. The smooth portions of the resulting eye movement traces were fit by convolving the stimulus velocity with an exponential having variable onset latency, time constant and amplitude. Smooth eye movements with few saccades were observed for all stimuli. Pursuit responses to stimuli having a significant luminance component are well-fit by exponentials having latencies and time constants on the order of 100 msec. Increases in pursuit response latency on the order of 100-200 msec are observed in response to certain stimuli, which occur in pairs of complementary hues, corresponding to the intersection of the stimulus section with the subjects' equiluminant plane. Smooth eye movements can be made in response to purely chromatic stimuli, but are slower than responses to stimuli with a luminance component.

  5. Psychophysical chromatic mechanisms in macaque monkey.

    Science.gov (United States)

    Stoughton, Cleo M; Lafer-Sousa, Rosa; Gagin, Galina; Conway, Bevil R

    2012-10-24

    Chromatic mechanisms have been studied extensively with psychophysical techniques in humans, but the number and nature of the mechanisms are still controversial. Appeals to monkey neurophysiology are often used to sort out the competing claims and to test hypotheses arising from the experiments in humans, but psychophysical chromatic mechanisms have never been assessed in monkeys. Here we address this issue by measuring color-detection thresholds in monkeys before and after chromatic adaptation, employing a standard approach used to determine chromatic mechanisms in humans. We conducted separate experiments using adaptation configured as either flickering full-field colors or heterochromatic gratings. Full-field colors would favor activity within the visual system at or before the arrival of retinal signals to V1, before the spatial transformation of color signals by the cortex. Conversely, gratings would favor activity within the cortex where neurons are often sensitive to spatial chromatic structure. Detection thresholds were selectively elevated for the colors of full-field adaptation when it modulated along either of the two cardinal chromatic axes that define cone-opponent color space [L vs M or S vs (L + M)], providing evidence for two privileged cardinal chromatic mechanisms implemented early in the visual-processing hierarchy. Adaptation with gratings produced elevated thresholds for colors of the adaptation regardless of its chromatic makeup, suggesting a cortical representation comprised of multiple higher-order mechanisms each selective for a different direction in color space. The results suggest that color is represented by two cardinal channels early in the processing hierarchy and many chromatic channels in brain regions closer to perceptual readout.

  6. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  7. Proteomic analysis of chromate response in Staphylococcus ...

    African Journals Online (AJOL)

    user

    2012-04-18

    Apr 18, 2012 ... analysis was performed to identify proteins involved in chromate stress response of Staphylococcus saprophyticus .... Proteins were visualized by PharosFXTM molecular imager and scanner ..... Molecular dynamics of the.

  8. Diffractive elements performance in chromatic confocal microscopy

    International Nuclear Information System (INIS)

    Garzon, J; Duque, D; Alean, A; Toledo, M; Meneses, J; Gharbi, T

    2011-01-01

    The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.

  9. Newborns' Discrimination of Chromatic from Achromatic Stimuli.

    Science.gov (United States)

    Adams, Russell J.; And Others

    1986-01-01

    Two experiments assessed the extent of newborns' ability to discriminate color. Results imply that newborns have some, albeit limited, capacity to discriminate chromatic from achromatic stimuli, and hence, are at least dichromats. (Author/DR)

  10. Chromatic Dispersion Estimation in Digital Coherent Receivers

    DEFF Research Database (Denmark)

    Soriano, Ruben Andres; Hauske, Fabian N.; Guerrero Gonzalez, Neil

    2011-01-01

    Polarization-diverse coherent demodulation allows to compensate large values of accumulated linear distortion by digital signal processing. In particular, in uncompensated links without optical dispersion compensation, the parameter of the residual chromatic dispersion (CD) is vital to set...

  11. Chromate dermatitis from a boiler lining.

    Science.gov (United States)

    Rycroft, R J; Calnan, C D

    1977-08-01

    Chromate dermatitis is described in a mechanical fitter working inside boiler combustion chambers. A source of hexavalent chromate is traced to the action of the heat and alkaline fuel ash on trivalent chrome ore in parts of the refractory lining. Removal of the patient from this contact has resulted in almost complete clearing of his dermatitis, without any relapse, during a 9-month follow-up period.

  12. Overview of magnetic nonlinear beam dynamics in the RHIC

    International Nuclear Information System (INIS)

    Luo, Y.; Bai, M.; Beebe-Wang, J.; Bengtsson, J.; Calaga, R.; Fischer, W.; Jain, A.; Pilat, F.; Ptitsyn, V.; Malitsky, N.; Robert-Demolaize, G.; Satogata, T.; Tepikian, S.; Tomas, R.; Trbojevic, D.

    2009-01-01

    In this article we review our studies of nonlinear beam dynamics due to the nonlinear magnetic field errors in the Relativistic Heavy Ion Collider (RHIC). Nonlinear magnetic field errors, including magnetic field errors in interaction regions (IRs), chromatic sextupoles, and sextupole components from arc main dipoles are discussed. Their effects on beam dynamics and beam dynamic aperture are evaluated. The online methods to measure and correct the IR nonlinear field errors, second order chromaticities, and horizontal third order resonance are presented. The overall strategy for nonlinear corrections in RHIC is discussed

  13. The chromatic class and the chromatic number of the planar conjugated triangulation

    OpenAIRE

    Malinina, Natalia

    2013-01-01

    This material is dedicated to the estimation of the chromatic number and chromatic class of the conjugated triangulation (first conversion) and also of the second conversion of the planar triangulation. Also this paper introduces some new hypotheses, which are equivalent to Four Color Problem.

  14. Mechanisms of chromate adsorption on boehmite

    International Nuclear Information System (INIS)

    Johnston, Chad P.; Chrysochoou, Maria

    2015-01-01

    Graphical abstract: - Highlights: • We characterized chromate adsorption on boehmite using molecular modeling and spectroscopy. • Chromate forms a mixture of outer-sphere and inner-sphere complexes. • Inner-sphere complexes are in monodentate and bidentate configuration. - Abstract: Adsorption reactions play an important role in the transport behavior of groundwater contaminants. Molecular-scale information is needed to elucidate the mechanisms by which ions coordinate to soil mineral surfaces. In this study, we characterized the mechanisms of chromate adsorption on boehmite (γ-AlOOH) using a combination of extended X-ray absorption fine structure (EXAFS) measurements, in situ attenuated total reflectance Fourier transform infrared spectroscopy, and quantum chemical calculations. The effects of pH, ionic strength, and aqueous chromate concentration were investigated. Our overall findings were that chromate primarily forms outer-sphere complexes on boehmite over a broad range of pH and aqueous concentrations. Additionally, a small fraction of monodentate and bidentate inner-sphere complexes are present under acidic conditions, as evidenced by two sets of chromate stretching vibrations at approximately 915, 870, and 780 cm −1 , and 940, 890, 850, and 780 cm −1 , respectively. The bidentate complex is supported by a best-fit Cr-Al distance in the EXAFS of 3.2 Å. Results from DFT also support the formation of monodentate and bidentate complexes, which are predicted to results in Gibbs energy changes of −140.4 and −62.5 kJ mol −1 , respectively. These findings are consistent with the intermediate binding strength of chromate with respect to similar oxyanions such as sulfate and selenite. Overall, the surface species identified in this work can be used to develop a more accurate stoichiometric framework in mechanistic adsorption models

  15. Arsenate and chromate incorporation in schwertmannite

    International Nuclear Information System (INIS)

    Regenspurg, Simona; Peiffer, Stefan

    2005-01-01

    High concentrations of Cr (up to 812 ppm) and As (up to 6740 ppm) were detected in precipitates of the mineral schwertmannite in areas influenced by acid mine drainage. Schwertmannite may act as well as a natural filter for these elements in water as well as their source by releasing the previously bound elements during its dissolution or mineral-transformation. The mechanisms of uptake and potential release for the species arsenate and chromate were investigated by performing synthesis and stability experiments with schwertmannite. Schwertmannite, synthesized in solutions containing arsenate in addition to sulphate, was enriched by up to 10.3 wt% arsenate without detectable structural changes as demonstrated by powder X-ray diffraction (XRD). In contrast to arsenate, a total substitution of sulphate by chromate was possible in sulphate-free solutions. Thereby, the chromate content in schwertmannite could reach 15.3 wt%. To determine the release of oxyanions from schwertmannite over time, synthetic schwertmannite samples containing varying amounts of sulphate, chromate and arsenate were kept at a stable pH of either 2 or 4 over 1 year in suspension. At several time intervals Fe and the oxyanions were measured in solution and alterations of the solid part were observed by XRD and Fourier-Transform infrared (FT-IR) spectroscopy. At pH 2 schwertmannite partly dissolved and the total release of arsenate (24%) was low in contrast to chromate (35.4-57.5%) and sulphate (67-76%). Accordingly, the ionic activity product (log IAP) of arsenated schwertmannite was lowest (13.5), followed by the log IAP for chromated schwertmannite (16.2-18.5) and the log IAP for regular (=non-substituted) schwertmannite (18). At pH 4 schwertmannite transformed to goethite, an effect which occurred at the fastest rate for regular schwertmannite (=arsenate- and chromate-free), followed by chromate and arsenate containing schwertmannite. Both chromate and more evidently arsenate have a

  16. Simultaneous chromatic and luminance human electroretinogram responses.

    Science.gov (United States)

    Parry, Neil R A; Murray, Ian J; Panorgias, Athanasios; McKeefry, Declan J; Lee, Barry B; Kremers, Jan

    2012-07-01

    The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats' ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post-receptoral pathways that are in operation from the earliest stages of visual processing.

  17. Color constancy by characterization of illumination chromaticity

    Science.gov (United States)

    Nikkanen, Jarno T.

    2011-05-01

    Computational color constancy algorithms play a key role in achieving desired color reproduction in digital cameras. Failure to estimate illumination chromaticity correctly will result in invalid overall colour cast in the image that will be easily detected by human observers. A new algorithm is presented for computational color constancy. Low computational complexity and low memory requirement make the algorithm suitable for resource-limited camera devices, such as consumer digital cameras and camera phones. Operation of the algorithm relies on characterization of the range of possible illumination chromaticities in terms of camera sensor response. The fact that only illumination chromaticity is characterized instead of the full color gamut, for example, increases robustness against variations in sensor characteristics and against failure of diagonal model of illumination change. Multiple databases are used in order to demonstrate the good performance of the algorithm in comparison to the state-of-the-art color constancy algorithms.

  18. Total dominator chromatic number of a graph

    Directory of Open Access Journals (Sweden)

    Adel P. Kazemi

    2015-06-01

    Full Text Available Given a graph $G$, the total dominator coloring problem seeks a proper coloring of $G$ with the additional property that every vertex in the graph is adjacent to all vertices of a color class. We seek to minimize the number of color classes. We initiate to study this problem on several classes of graphs, as well as finding general bounds and characterizations. We also compare the total dominator chromatic number of a graph with the chromatic number and the total domination number of it.

  19. The chromatic polynomial and list colorings

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2009-01-01

    We prove that, if a graph has a list of k available colors at every vertex, then the number of list-colorings is at least the chromatic polynomial evaluated at k when k is sufficiently large compared to the number of vertices of the graph.......We prove that, if a graph has a list of k available colors at every vertex, then the number of list-colorings is at least the chromatic polynomial evaluated at k when k is sufficiently large compared to the number of vertices of the graph....

  20. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    Phos). The treatments are within the same concentration region, and they have a mutual pat-ent pending. Although some tests still need to be conducted, the following aspects are clear at the present time: The general appearance of the passivated zinc surface is very similar to a standard yellow chromate treatment...... successfully. The corrosion resistance against white rust on zinc and zinc alloys is just as good as that of yellow chromate, although the result de-pends on the corrosion test method as well as on the nature of the zinc substrate pas-sivated. The passivation procedure is simply a dip for approxi-mately 2...

  1. Measurement and correction of chromaticity in Hefei light source

    International Nuclear Information System (INIS)

    Sun Baogen; Xu Hongliang; He Duohui; Wang Junhua; Lu Ping

    2001-01-01

    The measurement and correction of chromaticity for Hefei light source is introduced. The natural chromaticity is obtained by detecting the variation of the betatron tune with the main dipole field strength. The correction chromaticity is obtained by detecting the variation of the betatron tune with the RF frequency. The theoretic analysis and formula for the two methods is given. The measurement results of chromaticity are given

  2. Tune modulation due to synchrotron oscillations and chromaticity, and the dynamic aperture

    International Nuclear Information System (INIS)

    Parzen, G.

    1995-01-01

    A tracking study was done of the effects of a tune modulations, due to synchrotron oscillations and the tune dependence on momentum (chromaticity), on the dynamic aperture. The studies were done using several RHIC lattices and tracking runs of about 1 x 10 6 turns. The dynamic aperture was found to decrease roughly linearly with the amplitude of the tune modulation. Lower order non-linear resonances, like the 1/3 and 1/4 resonance are not crossed because of the tune modulation. Three different cases were studied, corresponding to RHIC lattices with different β*, and with different synchrotron oscillation amplitudes. In each case, the tune modulation amplitude was varied by changing the chromaticity. In each case, roughly the same result, was found. The result found here for the effect of a tune modulation due to chromaticity may be compared with the result found for the effect of a tune modulation due to a gradient ripple in the quadrupoles. The effect of a tune modulation due to a gradient ripple appears to be about 4 times stronger than the effect of a tune modulation due to chromaticity and synchrotron oscillations

  3. Thermal reactions of some calcium, strontium, and barium chromates

    International Nuclear Information System (INIS)

    Piekarska-Piesse, B.; Gontarz, Z.; Ostrowski, A.; Kucharski, R.

    2000-01-01

    Thermal decomposition of calcium chromates and solid state reactions of barium and strontium chromates(VI) with barium and strontium hydroxides and carbonates, as well as the reduction of chromates by carbon and hydrogen, have been investigated. The mechanisms of individual stages of the thermal decomposition have been proposed on the basis of morphological classification. (author)

  4. CERN Video News on line

    CERN Multimedia

    2003-01-01

    The latest CERN video news is on line. In this issue : an interview with the Director General and reports on the new home for the DELPHI barrel and the CERN firemen's spectacular training programme. There's also a vintage video news clip from 1954. See: www.cern.ch/video or Bulletin web page

  5. Development of Chromatic Induction in Infancy

    Science.gov (United States)

    Okamura, Hiromi; Kanazawa, So; Yamaguchi, Masami K.

    2007-01-01

    The perception of colour in an embedded field is affected by the surround colour. This phenomenon is known as chromatic induction. In the present study we investigated whether the colour perception by infants aged 5-7 months could be affected by the surround colour. In Experiments 1 and 2 each stimulus was composed of an array of six squares in…

  6. Chromatic Dimensions Earthy, Watery, Airy, and Fiery.

    Science.gov (United States)

    Albertazzi, Liliana; Koenderink, Jan J; van Doorn, Andrea

    2015-01-01

    In our study, for a small number of antonyms, we investigate whether they are cross-modally or ideaesthetically related to the space of colors. We analyze the affinities of seven antonyms (cold-hot, dull-radiant, dead-vivid, soft-hard, transparent-chalky, dry-wet, and acid-treacly) and their intermediate connotations (cool-warm, matt-shiny, numb-lively, mellow-firm, semi-transparent-opaque, semi-dry-moist, and sour-sweet) as a function of color. We find that some antonyms relate to chromatic dimensions, others to achromatic ones. The cold-hot antonym proves to be the most salient dimension. The dry-wet dimension coincides with the cold-hot dimension, with dry corresponding to hot and wet to cold. The acid-treacly dimension proves to be transversal to the cold-hot dimension; hence, the pairs mutually span the chromatic domain. The cold-hot and acid-treacly antonyms perhaps recall Hering's opponent color system. The dull-radiant, transparent-chalky, and dead-vivid pairs depend little upon chromaticity. Of all seven antonyms, only the soft-hard one turns out to be independent of the chromatic structure. © The Author(s) 2015.

  7. Chromatic roots and limits of dense graphs

    Czech Academy of Sciences Publication Activity Database

    Csikvári, P.; Frenkel, P. E.; Hladký, Jan; Hubai, T.

    2017-01-01

    Roč. 340, č. 5 (2017), s. 1129-1135 ISSN 0012-365X EU Projects: European Commission(XE) 628974 - PAECIDM Institutional support: RVO:67985840 Keywords : chromatic root * graph limit * holomorphic moment Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.639, year: 2016 http://www.sciencedirect.com/science/article/pii/S0012365X16303661

  8. Chromatic Roots and Limits of Dense Graphs

    Czech Academy of Sciences Publication Activity Database

    Csikvári, P.; Frenkel, E.; Hladký, Jan; Hubai, T.

    2017-01-01

    Roč. 340, č. 5 (2017), s. 1129-1135 ISSN 0012-365X Institutional support: RVO:67985807 Keywords : chromatic root * graph limit * holomorphic moment Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.639, year: 2016

  9. Chromaticity measurement during beam energy ramp in Indus-2

    International Nuclear Information System (INIS)

    Husain, Riyasat; Vats, D.K.; Ghodke, A.D.

    2013-01-01

    Chromaticity is one of the important parameters of circular accelerators and plays crucial role in its operation. In Indus-2 storage ring the natural chromaticity is -19 and -12 in horizontal and vertical planes respectively. For the good injection at 550 MeV in Indus-2, chromaticity needs to be kept at (+1, +1). The corrected chromaticity does not remain constant during the energy ramp up to 2.5 GeV. We measured Indus-2 storage ring chromaticity by the conventional RF frequency change method. The measurement method and the result of the measurement are reported in this paper. (author)

  10. On-line moisture analysis

    CERN Document Server

    Cutmore, N G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk mater...

  11. Three-dimensional shape perception from chromatic orientation flows

    Science.gov (United States)

    Zaidi, Qasim; Li, Andrea

    2010-01-01

    The role of chromatic information in 3-D shape perception is controversial. We resolve this controversy by showing that chromatic orientation flows are sufficient for accurate perception of 3-D shape. Chromatic flows required less cone contrast to convey shape than did achromatic flows, thus ruling out luminance artifacts as a problem. Luminance artifacts were also ruled out by a protanope’s inability to see 3-D shape from chromatic flows. Since chromatic orientation flows can only be extracted from retinal images by neurons that are responsive to color modulations and selective for orientation, the psychophysical results also resolve the controversy over the existence of such neurons. In addition, we show that identification of 3-D shapes from chromatic flows can be masked by luminance modulations, indicating that it is subserved by orientation-tuned neurons sensitive to both chromatic and luminance modulations. PMID:16961963

  12. Sorting chromatic sextupoles for easily and effectively correcting second order chromaticity in the Relativistic Heavy Ion Collider

    International Nuclear Information System (INIS)

    Luo, Y.; Tepikian, S.; Fischer, W.; Robert-Demolaize, G.; Trbojevic, D.

    2009-01-01

    Based on the contributions of the chromatic sextupole families to the half-integer resonance driving terms, we discuss how to sort the chromatic sextupoles in the arcs of the Relativistic Heavy Ion Collider (RHIC) to easily and effectively correct the second order chromaticities. We propose a method with 4 knobs corresponding to 4 pairs of chromatic sextupole families to online correct the second order chromaticities. Numerical simulation justifies this method, showing that this method reduces the unbalance in the correction strengths of sextupole families and avoids the reversal of sextupole polarities. Therefore, this method yields larger dynamic apertures for the proposed RHIC 2009 100GeV polarized proton run lattices

  13. On line ultrasonic integrated backscatter

    International Nuclear Information System (INIS)

    Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

    1988-01-01

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  14. On-line nuclear orientation

    International Nuclear Information System (INIS)

    Krane, K.S.

    1990-01-01

    This grant has as its overall goal the pursuit of on-line nuclear orientation experiments for the purpose of eliciting details of nuclear structure from the decays of neutron-deficient nuclei, such as those produced by the Holifield Heavy-Ion Research Facility at Oak Ridge and extracted by the UNISOR Isotope Separator. This paper discusses: refrigerator development; the decay of 184 Au; the decay of 191 Hg to 191 Au; the decay of 189 Pt to 189 Ir; the decays of 109,111 Pd; the decay of 172 Er; and solid angle corrections

  15. Chromaticity compensation scheme for the Main Injector

    International Nuclear Information System (INIS)

    Bogacz, S.A.

    1993-05-01

    The current Main Injector lattice is studied in the context of full chromaticity compensation in the presence of the eddy current, saturation and the end-pack sextupole fields generated by the dipole magnets. Two families of correcting sextupole magnets are placed to compensate these fields and to adjust the chromaticity (in both planes) to some desired value. Variation of the dipole induced sextupole fields with the B-field (changing along a ramp) are modeled according to recent experimental measurements of the Main Injector dipole magnet Analysis of the required sextupole strengths is carried out along two realistic momentum ramps. The results of our calculation give quantitative insight into the requisite performance of the sextupole magnets

  16. Study of chromate coatings by radioisotope tracing

    International Nuclear Information System (INIS)

    Drozda, T.; Maleczki, E.; Farkas, G.

    1984-01-01

    New radioactive tracer methods were developed to determine chromium(III) and total chromium [chromium(III)+chromium(VI)] content simultaneously. They are capable of investigating solutions and the conversion coating itself in the solid phase, respectively. The increase of chromium(III) concentration in the yellow chromate coating, and the chromium(III) to total chromium ratio in the conversion coating were determined as a function of the treating period. (author)

  17. Schottky signal analysis: tune and chromaticity computation

    CERN Document Server

    Chanon, Ondine

    2016-01-01

    Schottky monitors are used to determine important beam parameters in a non-destructive way. The Schottky signal is due to the internal statistical fluctuations of the particles inside the beam. In this report, after explaining the different components of a Schottky signal, an algorithm to compute the betatron tune is presented, followed by some ideas to compute machine chromaticity. The tests have been performed with offline and/or online LHC data.

  18. Forcing clique immersions through chromatic number

    OpenAIRE

    Gauthier, Gregory; Le, Tien-Nam; Wollan, Paul

    2017-01-01

    Building on recent work of Dvo\\v{r}\\'ak and Yepremyan, we show that every simple graph of minimum degree $7t+7$ contains $K_t$ as an immersion and that every graph with chromatic number at least $3.54t + 4$ contains $K_t$ as an immersion. We also show that every graph on $n$ vertices with no stable set of size three contains $K_{2\\lfloor n/5 \\rfloor}$ as an immersion.

  19. V1 mechanisms underlying chromatic contrast detection

    Science.gov (United States)

    Hass, Charles A.

    2013-01-01

    To elucidate the cortical mechanisms of color vision, we recorded from individual primary visual cortex (V1) neurons in macaque monkeys performing a chromatic detection task. Roughly 30% of the neurons that we encountered were unresponsive at the monkeys' psychophysical detection threshold (PT). The other 70% were responsive at threshold but on average, were slightly less sensitive than the monkey. For these neurons, the relationship between neurometric threshold (NT) and PT was consistent across the four isoluminant color directions tested. A corollary of this result is that NTs were roughly four times lower for stimuli that modulated the long- and middle-wavelength sensitive cones out of phase. Nearly one-half of the neurons that responded to chromatic stimuli at the monkeys' detection threshold also responded to high-contrast luminance modulations, suggesting a role for neurons that are jointly tuned to color and luminance in chromatic detection. Analysis of neuronal contrast-response functions and signal-to-noise ratios yielded no evidence for a special set of “cardinal color directions,” for which V1 neurons are particularly sensitive. We conclude that at detection threshold—as shown previously with high-contrast stimuli—V1 neurons are tuned for a diverse set of color directions and do not segregate naturally into red–green and blue–yellow categories. PMID:23446689

  20. Chromate coating of zinc-aluminum plating on mild steel

    International Nuclear Information System (INIS)

    Haque, I.; Khan, A.; Nadeem, A.

    2005-01-01

    The chromate coating on zinc-aluminium deposits has been studied. Zinc-aluminium deposition from non-cyanide bath was carried out at current density 3-3.5 A/dm/sup 2/, plating voltage approx. equal to 1.25 V, temperature 18-20 deg. C, for 15 min. The effect of aluminium chloride on the rest potentials of golden, colorless and non-chromated zinc-aluminium alloy deposits was observed. It was found that rest potential was slightly increased with the increase in the concentration of aluminium chloride, only in the case of golden chromating. The rest potential of colorless chromated zinc-aluminium deposits on mild steel were observed to have no correlation with aluminium chloride concentration. The abrasion resistance of colorless chromating was better than golden chromating. (author)

  1. Stimulus size dependence of hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Kellner, Christian Johannes; Wachtler, Thomas

    2016-03-01

    A chromatic surround induces a change in the perceived hue of a stimulus. This shift in hue depends on the chromatic difference between the stimulus and the surround. We investigated how chromatic induction varies with stimulus size and whether the size dependence depends on the surround hue. Subjects performed asymmetric matching of color stimuli with different sizes in surrounds of different chromaticities. Generally, induced hue shifts decreased with increasing stimulus size. This decrease was quantitatively different for different surround hues. However, when size effects were normalized to an overall induction strength, the chromatic specificity was largely reduced. The separability of inducer chromaticity and stimulus size suggests that these effects are mediated by different neural mechanisms.

  2. On-line moisture analysis

    International Nuclear Information System (INIS)

    Cutmore, N.G.; Mijak, D.G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk material. Nuclear-based analysers measure the total hydrogen content in the sample and do not differentiate between free and combined moisture. Such analysers may also be sensitive to material presentation and elemental composition. Very low frequency electromagnetic probes, such as capacitance or conductance probes, operate in the frequency region where the DC conductivity dominates much of the response, which is a function not only of moisture content but also of ionic composition and chemistry. These problems are overcome using microwave transmission techniques, which also have the following advantages, as a true bulk moisture analysis is obtained, because a high percentage of the bulk material is analysed; the moisture estimate is mostly insensitive to any biased presentation of moisture, for example due to stratification of bulk material with different moisture content and because no physical contact is made between the sensor and the bulk material. This is

  3. Effect of impedance and higher order chromaticity on the measurement of linear chromaticity

    Directory of Open Access Journals (Sweden)

    V. H. Ranjbar

    2011-08-01

    Full Text Available The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta with respect to the “on momentum” particle (Δp/p. Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of Δp/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used to support the theory.

  4. Effect of impedance and higher order chromaticity on the measurement of linear chromaticity

    OpenAIRE

    V. H. Ranjbar; C. Y. Tan

    2011-01-01

    The combined effect of impedance and higher order chromaticity can act on the beam in a nontrivial manner which can cause a tune shift which depends on the relative momenta with respect to the “on momentum” particle (Δp/p). Experimentally, this tune shift affects the measurement of the linear chromaticity which is traditionally measured with a change of Δp/p. The theory behind this effect will be derived in this paper. Computer simulations and experimental data from the Tevatron will be used ...

  5. Scaling Laws for Dynamic Aperture due to Chromatic Sextupoles

    CERN Document Server

    Scandale, Walter

    1997-01-01

    Scaling laws for the dynamic aperture due to chromatic sextupoles are investigated. The problem is addressed in a simplified lattice model containing 4 N identical cells and one linear betatron phase shifter to break the overall cell-lattice symmetry. Two families of chromatic sextupoles are used to compensate the natural chromaticity. Analytical formulae for the dynamic apertur as a function of the number of cells and of the cell length are found and confirmed through computer tracking.

  6. Infinitely connected subgraphs in graphs of uncountable chromatic number

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2016-01-01

    Erdős and Hajnal conjectured in 1966 that every graph of uncountable chromatic number contains a subgraph of infinite connectivity. We prove that every graph of uncountable chromatic number has a subgraph which has uncountable chromatic number and infinite edge-connectivity. We also prove that......, if each orientation of a graph G has a vertex of infinite outdegree, then G contains an uncountable subgraph of infinite edge-connectivity....

  7. Chromatic induction from surrounding stimuli under perceptual suppression.

    Science.gov (United States)

    Horiuchi, Koji; Kuriki, Ichiro; Tokunaga, Rumi; Matsumiya, Kazumichi; Shioiri, Satoshi

    2014-11-01

    The appearance of colors can be affected by their spatiotemporal context. The shift in color appearance according to the surrounding colors is called color induction or chromatic induction; in particular, the shift in opponent color of the surround is called chromatic contrast. To investigate whether chromatic induction occurs even when the chromatic surround is imperceptible, we measured chromatic induction during interocular suppression. A multicolor or uniform color field was presented as the surround stimulus, and a colored continuous flash suppression (CFS) stimulus was presented to the dominant eye of each subject. The subjects were asked to report the appearance of the test field only when the stationary surround stimulus is invisible by interocular suppression with CFS. The resulting shifts in color appearance due to chromatic induction were significant even under the conditions of interocular suppression for all surround stimuli. The magnitude of chromatic induction differed with the surround conditions, and this difference was preserved regardless of the viewing conditions. The chromatic induction effect was reduced by CFS, in proportion to the magnitude of chromatic induction under natural (i.e., no-CFS) viewing conditions. According to an analysis with linear model fitting, we revealed the presence of at least two kinds of subprocesses for chromatic induction that reside at higher and lower levels than the site of interocular suppression. One mechanism yields different degrees of chromatic induction based on the complexity of the surround, which is unaffected by interocular suppression, while the other mechanism changes its output with interocular suppression acting as a gain control. Our results imply that the total chromatic induction effect is achieved via a linear summation of outputs from mechanisms that reside at different levels of visual processing.

  8. Third-rank chromatic aberrations of electron lenses.

    Science.gov (United States)

    Liu, Zhixiong

    2018-02-01

    In this paper the third-rank chromatic aberration coefficients of round electron lenses are analytically derived and numerically calculated by Mathematica. Furthermore, the numerical results are cross-checked by the differential algebraic (DA) method, which verifies that all the formulas for the third-rank chromatic aberration coefficients are completely correct. It is hoped that this work would be helpful for further chromatic aberration correction in electron microscopy. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Chromaticity measurement via the fourier spectrum of transverse oscillations

    International Nuclear Information System (INIS)

    Xi Yang

    2004-01-01

    Turn-by-turn data from a single BPM includes information on the chromaticity in sidebands displaced above and below the betatron frequency by an amount of the synchrotron frequency. It may be necessary to induce small amplitude synchrotron oscillation by giving the beam a small kick. Power spectrum of the BPM data gives clear chromatic sidebands, and they can be applied to the chromaticity measurement in the Fermilab Booster

  10. DESIGN OF A FAST CHROMATICITY JUMP IN RHIC

    International Nuclear Information System (INIS)

    MONTAG, C.; KEWISCH, J.; BRUNO, D.; GANETIS, G.; LOUIE, W.

    2003-01-01

    During transition crossing in the .Relativistic Heavy Ion Collider (RHIC), chromaticities have to change sign. This sign change is partially accomplished by the γ t quadrupole jump; however, the resulting chromaticity jump is only Δξ x = 2.1 in the horizontal and Δξ y = 2.4 in the vertical plane. To increase the jump height, a dedicated chromaticity jump scheme has been designed, consisting of fast power supplies connected to six sextupoles per ring, which is capable of providing a chromaticity jump of Δξ = 6

  11. The b-chromatic number of power graphs

    Directory of Open Access Journals (Sweden)

    Brice Effantin

    2003-06-01

    Full Text Available The b-chromatic number of a graph G is defined as the maximum number k of colors that can be used to color the vertices of G, such that we obtain a proper coloring and each color i, with 1 ≤ i≤ k, has at least one representant x i adjacent to a vertex of every color j, 1 ≤ j ≠ i ≤ k. In this paper, we discuss the b-chromatic number of some power graphs. We give the exact value of the b-chromatic number of power paths and power complete binary trees, and we bound the b-chromatic number of power cycles.

  12. Investigation of zinc chromatation Part II. Electrochemical impedance techniques

    International Nuclear Information System (INIS)

    Gabrielli, C.; Keddam, M.; Minouflet-Laurent, F.; Ogle, K.; Perrot, H.

    2003-01-01

    A mechanism to explain the formation of a chromate layer on zinc is proposed. It assumes that a ZnO inner film blocks the zinc surface on which the chromate layer grows. This layer has gel-like properties. The diffusion of the protons across the chromate layer and across the solution is supposed to be the kinetically limiting steps. This model was derived and experimentally tested in terms of impedance. The influences of the immersion time, mass transport, and pH of the chromatation solution were examined. A rather good agreement was found between the predictions of the model and the experimental results

  13. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response.

    Science.gov (United States)

    Barrionuevo, Pablo A; Cao, Dingcai

    2016-09-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a "winner-takes-all" process, suggesting the integration with PC signals might be mediated by a postretinal site.

  14. Study of chromatic adaptation using memory color matches, Part I: neutral illuminants.

    Science.gov (United States)

    Smet, Kevin A G; Zhai, Qiyan; Luo, Ming R; Hanselaer, Peter

    2017-04-03

    Twelve corresponding color data sets have been obtained using the long-term memory colors of familiar objects as target stimuli. Data were collected for familiar objects with neutral, red, yellow, green and blue hues under 4 approximately neutral illumination conditions on or near the blackbody locus. The advantages of the memory color matching method are discussed in light of other more traditional asymmetric matching techniques. Results were compared to eight corresponding color data sets available in literature. The corresponding color data was used to test several linear (von Kries, RLAB, etc.) and nonlinear (Hunt & Nayatani) chromatic adaptation transforms (CAT). It was found that a simple two-step von Kries, whereby the degree of adaptation D is optimized to minimize the DEu'v' prediction errors, outperformed all other tested models for both memory color and literature corresponding color sets, whereby prediction errors were lower for the memory color sets. The predictive errors were substantially smaller than the standard uncertainty on the average observer and were comparable to what are considered just-noticeable-differences in the CIE u'v' chromaticity diagram, supporting the use of memory color based internal references to study chromatic adaptation mechanisms.

  15. On-line data display

    Science.gov (United States)

    Lang, Sherman Y. T.; Brooks, Martin; Gauthier, Marc; Wein, Marceli

    1993-05-01

    A data display system for embedded realtime systems has been developed for use as an operator's user interface and debugging tool. The motivation for development of the On-Line Data Display (ODD) have come from several sources. In particular the design reflects the needs of researchers developing an experimental mobile robot within our laboratory. A proliferation of specialized user interfaces revealed a need for a flexible communications and graphical data display system. At the same time the system had to be readily extensible for arbitrary graphical display formats which would be required for data visualization needs of the researchers. The system defines a communication protocol transmitting 'datagrams' between tasks executing on the realtime system and virtual devices displaying the data in a meaningful way on a graphical workstation. The communication protocol multiplexes logical channels on a single data stream. The current implementation consists of a server for the Harmony realtime operating system and an application written for the Macintosh computer. Flexibility requirements resulted in a highly modular server design, and a layered modular object- oriented design for the Macintosh part of the system. Users assign data types to specific channels at run time. Then devices are instantiated by the user and connected to channels to receive datagrams. The current suite of device types do not provide enough functionality for most users' specialized needs. Instead the system design allows the creation of new device types with modest programming effort. The protocol, design and use of the system are discussed.

  16. Smarandachely Adjacent-Vertex-Distinguishing Proper Edge Chromatic Number of Cm∨Kn

    OpenAIRE

    Shunqin Liu

    2016-01-01

    According to different conditions, researchers have defined a great deal of coloring problems and the corresponding chromatic numbers. Such as, adjacent-vertex-distinguishing total chromatic number, adjacent-vertex-distinguishing proper edge chromatic number, smarandachely-adjacent-vertex-distinguishing proper edge chromatic number, smarandachely-adjacent-vertex-distinguishing proper total chromatic number. And we focus on the smarandachely adjacent-vertex-distinguishing proper edge chromatic...

  17. Chromatic Image Analysis For Quantitative Thermal Mapping

    Science.gov (United States)

    Buck, Gregory M.

    1995-01-01

    Chromatic image analysis system (CIAS) developed for use in noncontact measurements of temperatures on aerothermodynamic models in hypersonic wind tunnels. Based on concept of temperature coupled to shift in color spectrum for optical measurement. Video camera images fluorescence emitted by phosphor-coated model at two wavelengths. Temperature map of model then computed from relative brightnesses in video images of model at those wavelengths. Eliminates need for intrusive, time-consuming, contact temperature measurements by gauges, making it possible to map temperatures on complex surfaces in timely manner and at reduced cost.

  18. Determination of chromate ion in drilling mud filtrates

    International Nuclear Information System (INIS)

    Whitfill, D.

    1980-01-01

    A method of determining the amount of chromate ion in an aqueous drilling mud filtrate containing organic color bodies such as lignosulfate wherein the method comprises: (A) treating the aqueous filtrate with an effective amount of hydrogen peroxide to destroy said color bodies, and (B) measuring the amount of chromate ion in the filtrate by means of a spectrophotometer

  19. Correction of chromatic abberation in electrostatic lense systems containing quadrupoles

    International Nuclear Information System (INIS)

    Baranova, L.A.; Ul'yanova, N.S.; Yavor, S.Ya.

    1991-01-01

    Possibility of chromatic abberation correction in immersion systems consisting of axysimmetric and quadrupole lenses is shown. Concrete examples are presented. A number of new directions in science and technique, using ion beams are intensively developed presently. When using them accute necessity arises in chromatic abberation correction, while large-scale energy scattering is observed as a rule in such cases

  20. Chromatic aberrations of two-electrode transaxial mirrors

    International Nuclear Information System (INIS)

    Bejzina, L.G.; Karetskaya, S.P.

    1991-01-01

    Second order chromatic aberrations of electrostatic two-electrode transaxial mirrors in case the beam axial trajectory of charged particles is curvilinear are considered. Interrelations between coefficients of linear and angular chromatic aberrations are determined. Values of these coefficients for concave and convex transaxial mirrors with plane electrodes in dependence on potential ratio on electrodes by different onnular clearance radii are presented

  1. Understanding and controlling chromaticity shift in LED devices

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn; Mills, Karmann; Lamvik, Michael; Perkins, Curtis; Bobashev, Georgiy; Young, Joseph; Yaga, Robert; Johnson, Cortina

    2017-05-30

    Chromaticity shift in light-emitting diode (LED) devices arises from multiple mechanisms, and at least five different chromaticity shift modes (CSMs) have been identified to date. This paper focuses on the impacts of irreversible phosphor degradation as a cause of chromaticity shifts in LED devices. The nitride phosphors used to produce warm white LEDs are especially vulnerable to degradation due to thermal and chemical effects such as reactions with oxygen and water. As a result, LED devices utilizing these phosphors were found to undergo either a green shift or, less commonly, a red shift depending on the phosphor mix in the LED devices. These types of chromaticity shifts are classified as CSM-2 (green shift) and CSM-5 (red shift). This paper provides an overview of the kinetic processes responsible for green and red chromaticity shifts along with examples from accelerated stress testing of 6” downlights. Both CSMs appear to proceed through analogous mechanisms that are initiated at the surface of the phosphor. A green shift is produced by the surface oxidation of the nitride phosphor that changes the emission profile to lower wavelengths. As the surface oxidation reaction proceeds, reactant limitations slow the rate and bulk oxidation processes become more prevalent. We found that a red chromaticity shift arises from quenching of the green phosphor, also possibly due to surface reactions of oxygen, which shift the emission chromaticity in the red direction. In conclusion, we discuss the implications of these findings on projecting chromaticity.

  2. Cement-Induced Chromate Occupational Allergic Contact Dermatitis.

    Science.gov (United States)

    Kridin, Khalaf; Bergman, Reuven; Khamaisi, Mogher; Zelber-Sagi, Shira; Weltfriend, Sara

    2016-01-01

    Hexavalent chromium in cement is a common cause of occupational allergic contact dermatitis (OACD). Analysis of patch test data during 1999 to 2013 was done. Patients with cement-induced chromate OACD filled the Dermatology Life Quality Index, graded 1 to 5. Of 4846 consecutive patients who were patch tested, 146 (3%) were chromate-sensitive. Of 46 (31.5%) who presented with chromate OACD, 27 (59%) had cement-induced chromate OACD. The proportion of chromate-sensitive patients with clinically relevant cement exposure increased from 7.7% in 2002 to 2004 to 28.7% in 2011 to 2013 (P = 0.04). The median age of presentation was younger than for other chromate-sensitive patients (32 vs 42 years). Hand eczema (88.9%) was the most frequent clinical presentation. Of the 27 with cement-induced chromate OACD, 21 (77.8%) had ongoing dermatitis at the time of the review. Although 14/27 (51.9%) changed their occupation to avoid exposure to cement, symptoms persisted in 9/14 (64.3%). Prolonged exposure to cement before development of symptoms was associated with chronicity. All the symptomatic patients experienced at least a moderate effect on their quality of life (grade 3 or higher on the Dermatology Life Quality Index). We recommend the adoption of the European legislation in Israel, to reduce the prevalence of chromate OACD from cement.

  3. On the chromatic number of general Kneser hypergraphs

    DEFF Research Database (Denmark)

    Alishahi, Meysam; Hajiabolhassan, Hossein

    2015-01-01

    In a break-through paper, Lovász [20] determined the chromatic number of Kneser graphs. This was improved by Schrijver [27], by introducing the Schrijver subgraphs of Kneser graphs and showing that their chromatic number is the same as that of Kneser graphs. Alon, Frankl, and Lovász [2] extended...... their chromatic number as an approach to a supposition of Ziegler [35] and a conjecture of Alon, Drewnowski, and Łuczak [3]. In this work, our second main result is to improve this by computing the chromatic number of a large family of Schrijver hypergraphs. Our last main result is to prove the existence...... of a completely multicolored complete bipartite graph in every coloring of a graph which extends a result of Simonyi and Tardos [29].The first two results are proved using a new improvement of the Dol'nikov-Kříž [7,18] bound on the chromatic number of general Kneser hypergraphs....

  4. Luminance cues constrain chromatic blur discrimination in natural scene stimuli.

    Science.gov (United States)

    Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

    2013-03-22

    Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties.

  5. Analysis of transverse RMS emittance growth of a beam induced by spherical and chromatic aberration in a solenoidal field

    Energy Technology Data Exchange (ETDEWEB)

    Dash, Radhakanta, E-mail: radhakanta.physics@gmail.com [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nayak, Biswaranjan [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Sharma, Archana; Mittal, Kailash C. [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-01-21

    In a medium energy beam transport line transverse rms emittance growth associated with spherical aberration is analysed. An analytical expression is derived for beam optics in a solenoid field considering terms up to the third order in the radial displacement. Two important phenomena: effect of spherical aberrations in axial-symmetric focusing lens and influence of nonlinear space charge forces on beam emittance growth are discussed for different beam distributions. In the second part nonlinear effect associated with chromatic aberration that describes the growth of emittance and distortion of phase space area is discussed.

  6. The effect of chromatic and luminance information on reaction times.

    Science.gov (United States)

    O'Donell, Beatriz M; Barraza, Jose F; Colombo, Elisa M

    2010-07-01

    We present a series of experiments exploring the effect of chromaticity on reaction time (RT) for a variety of stimulus conditions, including chromatic and luminance contrast, luminance, and size. The chromaticity of these stimuli was varied along a series of vectors in color space that included the two chromatic-opponent-cone axes, a red-green (L-M) axis and a blue-yellow [S - (L + M)] axis, and intermediate noncardinal orientations, as well as the luminance axis (L + M). For Weber luminance contrasts above 10-20%, RTs tend to the same asymptote, irrespective of chromatic direction. At lower luminance contrast, the addition of chromatic information shortens the RT. RTs are strongly influenced by stimulus size when the chromatic stimulus is modulated along the [S - (L + M)] pathway and by stimulus size and adaptation luminance for the (L-M) pathway. RTs are independent of stimulus size for stimuli larger than 0.5 deg. Data are modeled with a modified version of Pieron's formula with an exponent close to 2, in which the stimulus intensity term is replaced by a factor that considers the relative effects of chromatic and achromatic information, as indexed by the RMS (square-root of the cone contrast) value at isoluminance and the Weber luminance contrast, respectively. The parameters of the model reveal how RT is linked to stimulus size, chromatic channels, and adaptation luminance and how they can be interpreted in terms of two chromatic mechanisms. This equation predicts that, for isoluminance, RTs for a stimulus lying on the S-cone pathway are higher than those for a stimulus lying on the L-M-cone pathway, for a given RMS cone contrast. The equation also predicts an asymptotic trend to the RT for an achromatic stimulus when the luminance contrast is sufficiently large.

  7. Modeling a multivariable reactor and on-line model predictive control.

    Science.gov (United States)

    Yu, D W; Yu, D L

    2005-10-01

    A nonlinear first principle model is developed for a laboratory-scaled multivariable chemical reactor rig in this paper and the on-line model predictive control (MPC) is implemented to the rig. The reactor has three variables-temperature, pH, and dissolved oxygen with nonlinear dynamics-and is therefore used as a pilot system for the biochemical industry. A nonlinear discrete-time model is derived for each of the three output variables and their model parameters are estimated from the real data using an adaptive optimization method. The developed model is used in a nonlinear MPC scheme. An accurate multistep-ahead prediction is obtained for MPC, where the extended Kalman filter is used to estimate system unknown states. The on-line control is implemented and a satisfactory tracking performance is achieved. The MPC is compared with three decentralized PID controllers and the advantage of the nonlinear MPC over the PID is clearly shown.

  8. Hue shifts produced by temporal asymmetries in chromatic signals depend on the alignment of the first and second harmonics.

    Science.gov (United States)

    Stockman, Andrew; Henning, G Bruce; West, Peter; Rider, Andrew T; Ripamonti, Caterina

    2017-08-01

    When M- or L-cone-isolating sawtooth waveforms flicker at frequencies between 4 and 13.3 Hz, there is a mean hue shift in the direction of the shallower sawtooth slope. Here, we investigate how this shift depends on the alignment of the first and second harmonics of sawtooth-like waveforms. Below 4 Hz, observers can follow hue variations caused by both harmonics, and reliably match reddish and greenish excursions. At higher frequencies, however, the hue variations appear as chromatic flicker superimposed on a steady light, the mean hue of which varies with second-harmonic alignment. Observers can match this mean hue against a variable-duty-cycle rectangular waveform and, separately, set the alignment at which the mean hue flips between reddish and greenish. The maximum hue shifts were approximately frequency independent and occurred when the peaks or troughs of the first and second harmonics roughly aligned at the visual input-consistent with the hue shift's being caused by an early instantaneous nonlinearity that saturates larger hue excursions. These predictions, however, ignore phase delays introduced within the chromatic pathway between its input and the nonlinearity that produces the hue shifts. If the nonlinearity follows the substantial filtering implied by the chromatic temporal contrast-sensitivity function, phase delays will alter the alignment of the first and second harmonics such that at the nonlinearity, the waveforms that produce the maximum hue shifts might well be those with the largest differences in rising and falling slopes-consistent with the hue shift's being caused by a central nonlinearity that limits the rate of hue change.

  9. On-line supercapacitor dynamic models for energy conversion and management

    International Nuclear Information System (INIS)

    Wu, C.H.; Hung, Y.H.; Hong, C.W.

    2012-01-01

    Highlights: ► On-line supercapacitor dynamic models are derived from time and frequency domains. ► Equivalent circuits with an ANN identifier are derived for nonlinear effects. ► Nonlinear effects include environmental temperature and operating voltage. ► Supercapacitor models can achieve both system fidelity and computation efficiency. - Abstract: This paper develops on-line nonlinear dynamic models of electrochemical supercapacitors which are for energy conversion and management. Based on the theory of electrochemical impedance spectroscopy, extensive alternative current impedance tests have been conducted to investigate the frequency-domain dynamics of these supercapacitors. A Nyquist diagram is plotted to help establish an equivalent electric circuit, which is regarded as the first-phase linear model. Two performance-influencing factors, environmental temperature and operating voltage, are considered as nonlinear effects. The nonlinear relationships among parameters of the capacitances and resistances in the first-phase model are established by a multi-layer artificial neural network. The neural parameters are trained using a back-propagation algorithm by feeding the experimental data bank. Combining the first-phase model and the on-line neural “parameter identifier”, the algorithm produces an on-line nonlinear dynamic model. Simulation results have proved that this proposed model is able to achieve both system fidelity and computational efficiency.

  10. Investigation of cleaning reagents for calcium chromate spills

    International Nuclear Information System (INIS)

    Dillard, B.M.

    1979-01-01

    Cleaning of calcium chromate spills can be a problem due to the insolubility of the material and the corrosiveness of several possible cleaning agents on the stainless steel equipment. Because of OSHA Standards for Cr(VI) exposure, it is necessary to remove spills as efficiently as possible in order to prevent the contaminant from becoming airborne. This study involved the comparison of several possible cleaning agents by studying the solubility of calcium chromate in each reagent. Two general types of reagents for dissolution of calcium chromate were investigated; those which act by conversion of the insoluble calcium chromate to a more soluble salt and to H 2 CrO 4 , and those which appear to act as complexing agents and thereby dissolve the calcium chromate. The most efficient of the reagents investigated was hydrochloric acid. However, even dilute solutions of halide acids destroy passivity of stainless steel causing pitting and stress-corrosion. Acetic acid and nitric acid were somewhat less efficient than hydrochloric acid in dissolving calcium chromate. However, both reagents are noncorrosive with stainless steel, nitric acid tending to favor passivity of the materials. Therefore, it is recommended that dilute solutions of either of these two acids be used for removal of calcium chromate spills in conjunction with mechanical methods that might be necessary, depending on the magnitude of the spill

  11. Influence of Spatial and Chromatic Noise on Luminance Discrimination.

    Science.gov (United States)

    Miquilini, Leticia; Walker, Natalie A; Odigie, Erika A; Guimarães, Diego Leite; Salomão, Railson Cruz; Lacerda, Eliza Maria Costa Brito; Cortes, Maria Izabel Tentes; de Lima Silveira, Luiz Carlos; Fitzgerald, Malinda E C; Ventura, Dora Fix; Souza, Givago Silva

    2017-12-05

    Pseudoisochromatic figures are designed to base discrimination of a chromatic target from a background solely on the chromatic differences. This is accomplished by the introduction of luminance and spatial noise thereby eliminating these two dimensions as cues. The inverse rationale could also be applied to luminance discrimination, if spatial and chromatic noise are used to mask those cues. In this current study estimate of luminance contrast thresholds were conducted using a novel stimulus, based on the use of chromatic and spatial noise to mask the use of these cues in a luminance discrimination task. This was accomplished by presenting stimuli composed of a mosaic of circles colored randomly. A Landolt-C target differed from the background only by the luminance. The luminance contrast thresholds were estimated for different chromatic noise saturation conditions and compared to luminance contrast thresholds estimated using the same target in a non-mosaic stimulus. Moreover, the influence of the chromatic content in the noise on the luminance contrast threshold was also investigated. Luminance contrast threshold was dependent on the chromaticity noise strength. It was 10-fold higher than thresholds estimated from non-mosaic stimulus, but they were independent of colour space location in which the noise was modulated. The present study introduces a new method to investigate luminance vision intended for both basic science and clinical applications.

  12. Detection of chromatic and luminance distortions in natural scenes.

    Science.gov (United States)

    Jennings, Ben J; Wang, Karen; Menzies, Samantha; Kingdom, Frederick A A

    2015-09-01

    A number of studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. In one study, Bex [J. Vis.10(2), 1 (2010)10.1167/10.2.231534-7362] measured sensitivity to sinusoidal spatial modulations of image scale. Here, we measure sensitivity to sinusoidal scale distortions applied to the chromatic, luminance, or both layers of natural scene images. We first established that sensitivity does not depend on whether the undistorted comparison image was of the same or of a different scene. Next, we found that, when the luminance but not chromatic layer was distorted, performance was the same regardless of whether the chromatic layer was present, absent, or phase-scrambled; in other words, the chromatic layer, in whatever form, did not affect sensitivity to the luminance layer distortion. However, when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. These detection threshold results complement the appearance of periodic distortions of the image scale: when the luminance layer is distorted visibly, the scene appears distorted, but when the chromatic layer is distorted visibly, there is little apparent scene distortion. We conclude that (a) observers have a built-in sense of how a normal image of a natural scene should appear, and (b) the detection of distortion in, as well as the apparent distortion of, natural scene images is mediated predominantly by the luminance layer and not chromatic layer.

  13. Spectrally balanced chromatic landing approach lighting system

    Science.gov (United States)

    Chase, W. D. (Inventor)

    1981-01-01

    Red warning lights delineate the runway approach with additional blue lights juxtaposed with the red lights such that the red lights are chromatically balanced. The red/blue point light sources result in the phenomenon that the red lights appear in front of the blue lights with about one and one-half times the diameter of the blue. To a pilot observing these lights along a glide path, those red lights directly below appear to be nearer than the blue lights. For those lights farther away seen in perspective at oblique angles, the red lights appear to be in a position closer to the pilot and hence appear to be above the corresponding blue lights. This produces a very pronounced three dimensional effect referred to as chromostereopsis which provides valuable visual cues to enable the pilot to perceive his actual position above the ground and the actual distance to the runway.

  14. Chromatic bifocus alignment system for SR stepper

    International Nuclear Information System (INIS)

    Miyatake, Tsutomu

    1991-01-01

    A new alignment system developed for synchrotron radiation (SR) X-ray stepper is described. The alignment system has three key elements as follows. The first is a chromatic bifocus optics which observe high contrast bright images of alignment marks printed on a mask and a wafer. The second is broad band light illumination to observe the wafer alignment mark images which is unaffected by resist film coated on a wafer. The third is a new correlation function which is used in measuring of displacement between a mask and a wafer. The alignment system has achieved alignment accuracy on the order of 0.01 μm. The experimental results of this alignment system are discussed in this paper. (author)

  15. Effect of radiation on hydrotalcites with chromates

    International Nuclear Information System (INIS)

    Martinez G, S.; Bulbulian, S.

    2002-01-01

    Nowadays the generation of radioactive wastes is matter of several studies. In this work anion material, chromates, in hydrotalcite are retained which are anion exchangers. It was proposed to heat the hydrotalcite until temperature of 1200 C with the purpose to form the (MgAl 2 O 4 ) spinel is very stable and in this way to immobilize strongly the anions. The effect of radiation on this compound and in particular the chromium lixiviation with solution 1N NaCl. It was found that in all case, the anions are strongly retained in the spinel formed. The radiation dose used for this was 100 Mrad, the samples were treated with NaCl 1N for studying the Cr lixiviation. The results show that for the calcined samples at 1200 C and irradiated there are not chromium escapes, which indicates that it is strongly retained in the spinel that is the formed structure after of the material calcination. (Author)

  16. Effects of chromatic image statistics on illumination induced color differences.

    Science.gov (United States)

    Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

    2013-09-01

    We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

  17. Lower and upper chromatic numbers for BSTSs(2h - 1

    Directory of Open Access Journals (Sweden)

    Marco Buratti

    2001-08-01

    Full Text Available In [Discrete Math. 174, (1997 247-259] an infinite class of STSs(2h - 1 was found with the upper chromatic number not(χ=h. We prove that in this class, for all STSs(2h - 1 with h<10, the lower chromatic number coincides with the upper chromatic number, i.e. χ=not(χ=h and moreover, there exists a infinite sub-class of STSs with χ=not(χ=h for any value of h.

  18. The importance of non-linearities in modern proton synchrotrons

    International Nuclear Information System (INIS)

    Wilson, E.J.N.

    1977-01-01

    The paper outlines the physics and mathematics of non-linear field errors in the quide fields of accelerators, with particular reference to large accelerators such as the SPS. These non-linearities give rise to closed orbital distortions and non-linear resonances or stopbands. Both of these effects are briefly discussed and the use of resonances for slow beam extraction is also described. Another problem considered is that of chromaticity of the particle beam. The use of sextupoles to correct chromaticity and the Landau damping of beam instabilities using octupoles are also discussed. In the final section the application of Hamiltonian mechanics to non-linearities is demonstrated. The author concludes that the effect of non-linearities on particle dynamics may place a more severe limit on intensity and storage time in large rings than any other effect in transverse phase space. (B.D.)

  19. Local chromatic correction scheme for LER of PEP-II

    International Nuclear Information System (INIS)

    Forest, E.; Robin, D.; Zholents, A.; Donald, M.; Helm, R.; Irwin, J.; Sullivan, M.K.

    1993-01-01

    The correction of the chromaticity of low-beta insertions in storage rings is usually made with sextupole lenses in the ring arcs. When decreasing the beta functions at the interaction point (IP), this technique becomes fairly ineffective, since it fails to properly correct the higher-order chromatic aberrations. Here we consider the approach for ampersand PEP-II B Factory low energy ring (LER) where the chromatic effects of the quadrupole lenses generating low beta functions at the IP are corrected locally with two families of sextupoles, one family for each plane. For the IP straight section the lattice is designed in such a way that the chromatic aberrations are made small and sextupole-like aberrations are eliminated. The results of dimensional tracking simulations are presented

  20. Spectrally-balanced chromatic approach-lighting system

    Science.gov (United States)

    Chase, W. D.

    1977-01-01

    Approach lighting system employing combinations of red and blue lights reduces problem of color-based optical illusions. System exploits inherent chromatic aberration of eye to create three-dimensional effect, giving pilot visual clues of position.

  1. Determination of percent calcium carbonate in calcium chromate

    International Nuclear Information System (INIS)

    Middleton, H.W.

    1979-01-01

    The precision, accuracy and reliability of the macro-combustion method is superior to the Knorr alkalimetric method, and it is faster. It also significantly reduces the calcium chromate waste accrual problem. The macro-combustion method has been adopted as the official method for determination of percent calcium carbonate in thermal battery grade anhydrous calcium chromate and percent calcium carbonate in quicklime used in the production of calcium chromate. The apparatus and procedure can be used to measure the percent carbonate in inorganic materials other than calcium chromate. With simple modifications in the basic apparatus and procedure, the percent carbon and hydrogen can be measured in many organic material, including polymers and polymeric formulations. 5 figures, 5 tables

  2. Preliminary Studies Of A Phase Modulation Technique For Measuring Chromaticity

    International Nuclear Information System (INIS)

    Tan, C.-Y.

    2006-01-01

    The classical method for measuring chromaticity is to slowly modulate the RF frequency and then measure the betatron tune excursion. The technique that is discussed in this paper instead modulates the phase of the RF and then the chromaticity is obtained by phase demodulating the betatron tune. This technique requires knowledge of the betatron frequency in real time in order for the phase to be demodulated. Fortunately, the Tevatron has a tune tracker based on the phase locked loop principle which fits this requirement. A preliminary study with this technique has showed that it is a promising method for doing continuous chromaticity measurement and raises the possibility of doing successful chromaticity feedback with it

  3. In vivo chromatic aberration in eyes implanted with intraocular lenses.

    Science.gov (United States)

    Pérez-Merino, Pablo; Dorronsoro, Carlos; Llorente, Lourdes; Durán, Sonia; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2013-04-12

    To measure in vivo and objectively the monochromatic aberrations at different wavelengths, and the chromatic difference of focus between green and infrared wavelengths in eyes implanted with two models of intraocular lenses (IOL). EIGHTEEN EYES PARTICIPATED IN THIS STUDY: nine implanted with Tecnis ZB99 1-Piece acrylic IOL and nine implanted with AcrySof SN60WF IOL. A custom-developed laser ray tracing (LRT) aberrometer was used to measure the optical aberrations, at 532 nm and 785 nm wavelengths. The monochromatic wave aberrations were described using a fifth-order Zernike polynomial expansion. The chromatic difference of focus was estimated as the difference between the equivalent spherical errors corresponding to each wavelength. Wave aberration measurements were highly reproducible. Except for the defocus term, no significant differences in high order aberrations (HOA) were found between wavelengths. The average chromatic difference of focus was 0.46 ± 0.15 diopters (D) in the Tecnis group, and 0.75 ± 0.12 D in the AcrySof group, and the difference was statistically significant (P Chromatic difference of focus in the AcrySof group was not statistically significantly different from the Longitudinal chromatic aberration (LCA) previously reported in a phakic population (0.78 ± 0.16 D). The impact of LCA on retinal image quality (measured in terms of Strehl ratio) was drastically reduced when considering HOA and astigmatism in comparison with a diffraction-limited eye, yielding the differences in retinal image quality between Tecnis and AcrySof IOLs not significant. LRT aberrometry at different wavelengths is a reproducible technique to evaluate the chromatic difference of focus objectively in eyes implanted with IOLs. Replacement of the crystalline lens by the IOL did not increase chromatic difference of focus above that of phakic eyes in any of the groups. The AcrySof group showed chromatic difference of focus values very similar to physiological values in

  4. Chromaticity and Glossiness of Gold, Silver, and Bronze Colors

    Directory of Open Access Journals (Sweden)

    Tomohisa Matsumoto

    2011-05-01

    Full Text Available Appearance of metallic colors, such as gold, silver and bronze, depends on chromaticity and glossiness of a surface. We aim to obtain the chromaticity region of gold, silver, and bronze by using CG simulated surfaces with various glossiness. The physical glossiness was defined by the intensity ratio of specular reflectance of the surface stimulus. The observer estimated degree of perceived glossiness, and also degree of gold, silver, or bronze appearance of the stimulus with a physical glossiness and a chromaticity. The results showed that the stimulus began to appear gold, silver or bronze at a certain chromaticity point only when the stimulus had glossiness. The chromaticity range, where gold, silver and bronze colors were observed, expanded as the degree of glossiness increased. Furthermore the ratio of the degree of gold, silver or bronze colors to that of glossiness of the stimulus was found to be different among the chromaticity points of the stimulus. This ratio was highest with highly saturated stimuli for gold and bronze colors, and with achromatic stimuli for silver color.

  5. Studies on biological reduction of chromate by Streptomyces griseus

    International Nuclear Information System (INIS)

    Poopal, Ashwini C.; Laxman, R. Seeta

    2009-01-01

    Chromium is a toxic heavy metal used in various industries and leads to environmental pollution due to improper handling. The most toxic form of chromium Cr(VI) can be converted to less toxic Cr(III) by reduction. Among the actinomycetes tested for chromate reduction, thirteen strains reduced Cr(VI) to Cr(III), of which one strain of Streptomyces griseus (NCIM 2020) was most efficient showing complete reduction within 24 h. The organism was able to use a number of carbon sources as electron donors. Sulphate, nitrate, chloride and carbonate had no effect on chromate reduction during growth while cations such as Cd, Ni, Co and Cu were inhibitory to varying degrees. Chromate reduction was associated with the bacterial cells and sonication was the best method of cell breakage to release the enzyme. The enzyme was constitutive and did not require presence of chromate during growth for expression of activity. Chromate reduction with cell free extract (CFE) was observed without added NADH. However, addition of NAD(P)H resulted in 2-3-fold increase in activity. Chromate reductase showed optimum activity at 28 deg. C and pH 7.

  6. Chromatic Perceptual Learning but No Category Effects without Linguistic Input.

    Science.gov (United States)

    Grandison, Alexandra; Sowden, Paul T; Drivonikou, Vicky G; Notman, Leslie A; Alexander, Iona; Davies, Ian R L

    2016-01-01

    Perceptual learning involves an improvement in perceptual judgment with practice, which is often specific to stimulus or task factors. Perceptual learning has been shown on a range of visual tasks but very little research has explored chromatic perceptual learning. Here, we use two low level perceptual threshold tasks and a supra-threshold target detection task to assess chromatic perceptual learning and category effects. Experiment 1 investigates whether chromatic thresholds reduce as a result of training and at what level of analysis learning effects occur. Experiment 2 explores the effect of category training on chromatic thresholds, whether training of this nature is category specific and whether it can induce categorical responding. Experiment 3 investigates the effect of category training on a higher level, lateralized target detection task, previously found to be sensitive to category effects. The findings indicate that performance on a perceptual threshold task improves following training but improvements do not transfer across retinal location or hue. Therefore, chromatic perceptual learning is category specific and can occur at relatively early stages of visual analysis. Additionally, category training does not induce category effects on a low level perceptual threshold task, as indicated by comparable discrimination thresholds at the newly learned hue boundary and adjacent test points. However, category training does induce emerging category effects on a supra-threshold target detection task. Whilst chromatic perceptual learning is possible, learnt category effects appear to be a product of left hemisphere processing, and may require the input of higher level linguistic coding processes in order to manifest.

  7. Chromatic assimilation unaffected by perceived depth of inducing light.

    Science.gov (United States)

    Shevell, Steven K; Cao, Dingcai

    2004-01-01

    Chromatic assimilation is a shift toward the color of nearby light. Several studies conclude that a neural process contributes to assimilation but the neural locus remains in question. Some studies posit a peripheral process, such as retinal receptive-field organization, while others claim the neural mechanism follows depth perception, figure/ground segregation, or perceptual grouping. The experiments here tested whether assimilation depends on a neural process that follows stereoscopic depth perception. By introducing binocular disparity, the test field judged in color was made to appear in a different depth plane than the light that induced assimilation. The chromaticity and spatial frequency of the inducing light, and the chromaticity of the test light, were varied. Chromatic assimilation was found with all inducing-light sizes and chromaticities, but the magnitude of assimilation did not depend on the perceived relative depth planes of the test and inducing fields. We found no evidence to support the view that chromatic assimilation depends on a neural process that follows binocular combination of the two eyes' signals.

  8. Characterizing chemical systems with on-line computers and graphics

    International Nuclear Information System (INIS)

    Frazer, J.W.; Rigdon, L.P.; Brand, H.R.; Pomernacki, C.L.

    1979-01-01

    Incorporating computers and graphics on-line to chemical experiments and processes opens up new opportunities for the study and control of complex systems. Systems having many variables can be characterized even when the variable interactions are nonlinear, and the system cannot a priori be represented by numerical methods and models. That is, large sets of accurate data can be rapidly acquired, then modeling and graphic techniques can be used to obtain partial interpretation plus design of further experimentation. The experimenter can thus comparatively quickly iterate between experimentation and modeling to obtain a final solution. We have designed and characterized a versatile computer-controlled apparatus for chemical research, which incorporates on-line instrumentation and graphics. It can be used to determine the mechanism of enzyme-induced reactions or to optimize analytical methods. The apparatus can also be operated as a pilot plant to design control strategies. On-line graphics were used to display conventional plots used by biochemists and three-dimensional response-surface plots

  9. Gamma irradiation effects of 51Cr(III) isotope exchange in doped magnesium chromate - zinc chromate mixtures

    International Nuclear Information System (INIS)

    Mahfouz, R.M.

    1984-01-01

    Gamma irradiation effects of 51 Cr(III) isotope exchange in magnesium chromate - zinc chromate mixtures doped with 51 Cr(III) were investigated. It was found that γ irradiation has an oxidation effect and the percentage of exchanged 51 Cr(VI) increases with the increasing γ-ray dose. The data are explained in terms of mechanistic model involving metal and ligand vacancies exchange and substitution reactions. (author)

  10. Representation of chromatic distribution for lighting system

    Science.gov (United States)

    Rossi, Maurizio; Musante, Fulvio

    2015-01-01

    For the luminaire manufacturer, the measurement of the lighting intensity distribution (LID) emitted by lighting fixture is based on photometry. So light is measured as an achromatic value of intensity and there is no the possibility to discriminate the measurement of white vs. colored light. At the Laboratorio Luce of Politecnico di Milano a new instrument for the measurement of spectral radiant intensities distribution for lighting system has been built: the goniospectra- radiometer. This new measuring tool is based on a traditional mirror gonio-photometer with a CCD spectraradiometer controlled by a PC. Beside the traditional representation of photometric distribution we have introduced a new representation where, in addition to the information about the distribution of luminous intensity in space, new details about the chromaticity characteristic of the light sources have been implemented. Some of the results of this research have been applied in developing and testing a new line of lighting system "My White Light" (the research project "Light, Environment and Humans" funded in the Italian Lombardy region Metadistretti Design Research Program involving Politecnico di Milano, Artemide, Danese, and some other SME of the Lighting Design district), giving scientific notions and applicative in order to support the assumption that colored light sources can be used for the realization of interior luminaries that, other than just have low power consumption and long life, may positively affect the mood of people.

  11. Shawnee Mission's On-Line Cataloging System

    Directory of Open Access Journals (Sweden)

    Ellen Wasby Miller

    1971-03-01

    Full Text Available An on-line cataloging pilot project for two elementary schools is discussed. The system components are 2740 terminals, upper-lower-case input, IBM's FASTER generalized software package, and usual cards/labels output. Reasons for choosing FASTER, software and hardware features, operating procedures, system performance and costs are detailed. Future expansion to cataloging 100,000 annual K-12 acquisitions, on-line circulation, retrospective conversion, and union book catalogs is set forth.

  12. INIS retrieval service, towards on-line

    International Nuclear Information System (INIS)

    Ebinuma, Yukio; Komatsubara, Yasutoshi

    1983-01-01

    Japan Atomic Energy Research Institute executes the retrieval service of INIS atomic energy information by batch system in cooperation with Genshiryoku Kozaikai. This service is very popular to the users in whole Japan, but the demand of on-line service has increased recently. Therefore, it was decided to begin the INIS on-line service from January, 1984, through the on-line information retrieval system of the Japan Information Center of Science and Technology. It is expected that when the operation will be started, the utilization of INIS atomic energy information in Japan will drastically increase. Also Japan Atomic Energy Research Institute has carried out the retrieval service by on-line system for those in the institute besides the batch system, accordingly, at this opportunity, the state of utilization of both systems and their distinction to use effectively, and the operation and the method of utilization of the on-line information retrieval system of JICST are explained. In the on-line system, the users are accessible to the data base themselves, and immediate information retrieval is possible, while in the batch system, the related information can be retrieved without fail, and the troublesome operation of equipment is not necessary. (Kako, I.)

  13. The influence of chromatic context on binocular color rivalry: Perception and neural representation

    Science.gov (United States)

    Hong, Sang Wook; Shevell, Steven K.

    2008-01-01

    The predominance of rivalrous targets is affected by surrounding context when stimuli rival in orientation, motion or color. This study investigated the influence of chromatic context on binocular color rivalry. The predominance of rivalrous chromatic targets was measured in various surrounding contexts. The first experiment showed that a chromatic surround's influence was stronger when the surround was uniform or a grating with luminance contrast (chromatic/black grating) compared to an equiluminant grating (chromatic/white). The second experiment revealed virtually no effect of the orientation of the surrounding chromatic context, using chromatically rivalrous vertical gratings. These results are consistent with a chromatic representation of the context by a non-oriented, chromatically selective and spatially antagonistic receptive field. Neither a double-opponent receptive field nor a receptive field without spatial antagonism accounts for the influence of context on binocular color rivalry. PMID:18331750

  14. Chromatic polynomials of planar triangulations, the Tutte upper bound and chromatic zeros

    International Nuclear Information System (INIS)

    Shrock, Robert; Xu Yan

    2012-01-01

    Tutte proved that if G pt is a planar triangulation and P(G pt , q) is its chromatic polynomial, then |P(G pt , τ + 1)| ⩽ (τ − 1) n−5 , where τ=(1+√5 )/2 and n is the number of vertices in G pt . Here we study the ratio r(G pt ) = |P(G pt , τ + 1)|/(τ − 1) n−5 for a variety of planar triangulations. We construct infinite recursive families of planar triangulations G pt,m depending on a parameter m linearly related to n and show that if P(G pt,m , q) only involves a single power of a polynomial, then r(G pt,m ) approaches zero exponentially fast as n → ∞. We also construct infinite recursive families for which P(G pt,m , q) is a sum of powers of certain functions and show that for these, r(G pt,m ) may approach a finite nonzero constant as n → ∞. The connection between the Tutte upper bound and the observed chromatic zero(s) near to τ + 1 is investigated. We report the first known graph for which the zero(s) closest to τ + 1 is not real, but instead is a complex-conjugate pair. Finally, we discuss connections with the nonzero ground-state entropy of the Potts antiferromagnet on these families of graphs. (paper)

  15. Study of chromatic adaptation using memory color matches, Part II: colored illuminants.

    Science.gov (United States)

    Smet, Kevin A G; Zhai, Qiyan; Luo, Ming R; Hanselaer, Peter

    2017-04-03

    In a previous paper, 12 corresponding color data sets were derived for 4 neutral illuminants using the long-term memory colours of five familiar objects. The data were used to test several linear (one-step and two-step von Kries, RLAB) and nonlinear (Hunt and Nayatani) chromatic adaptation transforms (CAT). This paper extends that study to a total of 156 corresponding color sets by including 9 more colored illuminants: 2 with low and 2 with high correlated color temperatures as well as 5 representing high chroma adaptive conditions. As in the previous study, a two-step von Kries transform whereby the degree of adaptation D is optimized to minimize the DEu'v' prediction errors outperformed all other tested models for both memory color and literature corresponding color sets, whereby prediction errors were lower for the memory color set. Most of the transforms tested, except the two- and one-step von Kries models with optimized D, showed large errors for corresponding color subsets that contained non-neutral adaptive conditions as all of them tended to overestimate the effective degree of adaptation in this study. An analysis of the impact of the sensor space primaries in which the adaptation is performed was found to have little impact compared to that of model choice. Finally, the effective degree of adaptation for the 13 illumination conditions (4 neutral + 9 colored) was successfully modelled using a bivariate Gaussian in a Macleod-Boyton like chromaticity diagram.

  16. Chromatic blur perception in the presence of luminance contrast.

    Science.gov (United States)

    Jennings, Ben J; Kingdom, Frederick A A

    2017-06-01

    Hel-Or showed that blurring the chromatic but not the luminance layer of an image of a natural scene failed to elicit any impression of blur. Subsequent studies have suggested that this effect is due either to chromatic blur being masked by spatially contiguous luminance edges in the scene (Journal of Vision 13 (2013) 14), or to a relatively compressed transducer function for chromatic blur (Journal of Vision 15 (2015) 6). To test between the two explanations we conducted experiments using as stimuli both images of natural scenes as well as simple edges. First, we found that in color-and-luminance images of natural scenes more chromatic blur was needed to perceptually match a given level of blur in an isoluminant, i.e. colour-only scene. However, when the luminance layer in the scene was rotated relative to the chromatic layer, thus removing the colour-luminance edge correlations, the matched blur levels were near equal. Both results are consistent with Sharman et al.'s explanation. Second, when observers matched the blurs of luminance-only with isoluminant scenes, the matched blurs were equal, against Kingdom et al.'s prediction. Third, we measured the perceived blur in a square-wave as a function of (i) contrast (ii) number of luminance edges and (iii) the relative spatial phase between the colour and luminance edges. We found that the perceived chromatic blur was dependent on both relative phase and the number of luminance edges, or dependent on the luminance contrast if only a single edge is present. We conclude that this Hel-Or effect is largely due to masking of chromatic blur by spatially contiguous luminance edges. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. In vivo longitudinal chromatic aberration of pseudophakic eyes.

    Science.gov (United States)

    Siedlecki, Damian; Jóźwik, Agnieszka; Zając, Marek; Hill-Bator, Aneta; Turno-Kręcicka, Anna

    2014-02-01

    To present the results of longitudinal chromatic aberration measurements on two groups of pseudophakic eyes in comparison to healthy eyes. The longitudinal chromatic aberration of the eye, defined as chromatic difference of refraction with disabled accommodation, was measured with the use of a visual refractometer with a custom-designed target illuminator consisting of a narrow-band RGB diode (blue λb = 470 ± 15 nm; green λg = 525 ± 18 nm; red λr = 660 ± 10 nm). The measurements were performed on nine eyes implanted with AcrySof IQ SN60WF, 14 eyes implanted with AcrySof SA60AT, and 10 phakic eyes under cycloplegia. The mean values of the longitudinal chromatic aberration between 470 and 660 nm for the control group was 1.12 ± 0.14 D. For SA60AT group, it was 1.45 ± 0.42 D whereas for SN60WF it was 1.17 ± 0.52 D. The statistical test showed significant difference between SA60AT and the control group (p chromatic aberration in vivo can be easily and reliably estimated with an adapted visual refractometer. The two groups of pseudophakic eyes measured in this study showed different values of chromatic aberration. Its magnitude for SA60AT group was significantly larger than for the control group whereas for SN60WF the difference was not significant. The optical material used for intraocular lens design may have significant influence on the magnitude of the chromatic aberration of the pseudophakic eye, and therefore on its optical and visual performance in polychromatic light.

  18. Chromatically unique 6-bridge graph theta(a,a,a,b,b,c

    Directory of Open Access Journals (Sweden)

    N.S.A. Karim

    2016-04-01

    Full Text Available For a graph $G$, let $P(G,\\lambda$ denote the chromatic polynomial of $G$. Two graphs $G$ and $H$ are chromatically equivalent if they share the same chromatic polynomial. A graph $G$ is chromatically unique if for any graph chromatically equivalent to $G$ is isomorphic to $G$. In this paper, the chromatically unique of a new family of 6-bridge graph $\\theta(a,a,a,b,b,c$ where $2\\le a\\le b\\le c$ is investigated.

  19. Chromate Binding and Removal by the Molybdate-Binding Protein ModA.

    Science.gov (United States)

    Karpus, Jason; Bosscher, Michael; Ajiboye, Ifedayo; Zhang, Liang; He, Chuan

    2017-04-04

    Effective and cheap methods and techniques for the safe removal of hexavalent chromate from the environment are in increasingly high demand. High concentrations of hexavalent chromate have been shown to have numerous harmful effects on human biology. We show that the E. coli molybdate-binding protein ModA is a genetically encoded tool capable of removing chromate from aqueous solutions. Although previously reported to not bind chromate, we show that ModA binds chromate tightly and is capable of removing chromate to levels well below current US federal standards. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Time-Varying FOPDT Modeling and On-line Parameter Identification

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Sun, Zhen

    2013-01-01

    on the Mixed-Integer-Nonlinear Programming, Least-Mean-Square and sliding window techniques. The proposed approaches can simultaneously estimate the time-dependent system parameters, as well as the unknown disturbance input if it is the case, in an on-line manner. The proposed concepts and algorithms...

  1. DNA-protein complexes induced by chromate and other carcinogens

    International Nuclear Information System (INIS)

    Costa, M.

    1991-01-01

    DNA-protein complexes induced in intact Chinese hamster ovary cells by chromate have been isolated, analyzed, and compared with those induced by cis-platinum, ultraviolet light, and formaldehyde. Actin has been identified as one of the major proteins complexed to DNA by chromate based upon its molecular weight, isoelectric point, positive reaction with an actin polyclonal antibody, and proteolytic mapping. Chromate and cis-platinum both complex proteins of similar molecular weight and isoelectric point, positive reaction with an actin polyclonal antibody, and proteolytic mapping. Chromate and cis-platinum both complex proteins of similar molecular weight and isoelectric points, and these complexes can be disrupted by chelating agents and sulfhydryl reducing agents, suggesting that the metal itself is participating in binding rather than having a catalytic or indirect role (i.e., oxygen radicals). In contrast, formaldehyde complexed histones to the DNA, and these complexes were not disrupted by chelating or reducing agents. An antiserum raised to chromate-induced DNA-protein complexes reacted primarily with 97,000 kDa protein that did not silver stain. Slot blots, as well as Western blots, were used to detect formation of p97 DNA crosslinks. This protein was complexed to the DNA by all four agents studied

  2. Changes in unique hues induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2016-03-01

    A chromatic surround can have a strong influence on the perceived hue of a stimulus. We investigated whether chromatic induction has similar effects on the perception of colors that appear pure and unmixed (unique red, green, blue, and yellow) as on other colors. Subjects performed unique hue settings of stimuli in isoluminant surrounds of different chromaticities. Compared with the settings in a neutral gray surround, unique hue settings altered systematically with chromatic surrounds. The amount of induced hue shift depended on the difference between stimulus and surround hues, and was similar for unique hue settings as for settings of nonunique hues. Intraindividual variability in unique hue settings was roughly twice as high as for settings obtained in asymmetric matching experiments, which may reflect the presence of a reference stimulus in the matching task. Variabilities were also larger with chromatic surrounds than with neutral gray surrounds, for both unique hue settings and matching of nonunique hues. The results suggest that the neural representations underlying unique hue percepts are influenced by the same neural processing mechanisms as the percepts of other colors.

  3. Primary chromatic aberration elimination via optimization work with genetic algorithm

    Science.gov (United States)

    Wu, Bo-Wen; Liu, Tung-Kuan; Fang, Yi-Chin; Chou, Jyh-Horng; Tsai, Hsien-Lin; Chang, En-Hao

    2008-09-01

    Chromatic Aberration plays a part in modern optical systems, especially in digitalized and smart optical systems. Much effort has been devoted to eliminating specific chromatic aberration in order to match the demand for advanced digitalized optical products. Basically, the elimination of axial chromatic and lateral color aberration of an optical lens and system depends on the selection of optical glass. According to reports from glass companies all over the world, the number of various newly developed optical glasses in the market exceeds three hundred. However, due to the complexity of a practical optical system, optical designers have so far had difficulty in finding the right solution to eliminate small axial and lateral chromatic aberration except by the Damped Least Squares (DLS) method, which is limited in so far as the DLS method has not yet managed to find a better optical system configuration. In the present research, genetic algorithms are used to replace traditional DLS so as to eliminate axial and lateral chromatic, by combining the theories of geometric optics in Tessar type lenses and a technique involving Binary/Real Encoding, Multiple Dynamic Crossover and Random Gene Mutation to find a much better configuration for optical glasses. By implementing the algorithms outlined in this paper, satisfactory results can be achieved in eliminating axial and lateral color aberration.

  4. Separating monocular and binocular neural mechanisms mediating chromatic contextual interactions.

    Science.gov (United States)

    D'Antona, Anthony D; Christiansen, Jens H; Shevell, Steven K

    2014-04-17

    When seen in isolation, a light that varies in chromaticity over time is perceived to oscillate in color. Perception of that same time-varying light may be altered by a surrounding light that is also temporally varying in chromaticity. The neural mechanisms that mediate these contextual interactions are the focus of this article. Observers viewed a central test stimulus that varied in chromaticity over time within a larger surround that also varied in chromaticity at the same temporal frequency. Center and surround were presented either to the same eye (monocular condition) or to opposite eyes (dichoptic condition) at the same frequency (3.125, 6.25, or 9.375 Hz). Relative phase between center and surround modulation was varied. In both the monocular and dichoptic conditions, the perceived modulation depth of the central light depended on the relative phase of the surround. A simple model implementing a linear combination of center and surround modulation fit the measurements well. At the lowest temporal frequency (3.125 Hz), the surround's influence was virtually identical for monocular and dichoptic conditions, suggesting that at this frequency, the surround's influence is mediated primarily by a binocular neural mechanism. At higher frequencies, the surround's influence was greater for the monocular condition than for the dichoptic condition, and this difference increased with temporal frequency. Our findings show that two separate neural mechanisms mediate chromatic contextual interactions: one binocular and dominant at lower temporal frequencies and the other monocular and dominant at higher frequencies (6-10 Hz).

  5. On-line monitoring for calibration reduction

    International Nuclear Information System (INIS)

    Hoffmann, M.

    2005-09-01

    On-Line Monitoring evaluates instrument channel performance by assessing its consistency with other plant indications. Elimination or reduction of unnecessary field calibrations can reduce associated labour costs, reduce personnel radiation exposure, and reduce the potential for calibration errors. On-line calibration monitoring is an important technique to implement a state-based maintenance approach and reduce unnecessary field calibrations. In this report we will look at how the concept is currently applied in the industry and what the arising needs are as it becomes more commonplace. We will also look at the PEANO System, a tool developed by the Halden Project to perform signal validation and on-line calibration monitoring. Some issues will be identified that are being addressed in the further development of these tools to better serve the future needs of the industry in this area. An outline for how to improve these points and which aspects should be taken into account is described in detail. (Author)

  6. On-line signal trend identification

    International Nuclear Information System (INIS)

    Tambouratzis, T.; Antonopoulos-Domis, M.

    2004-01-01

    An artificial neural network, based on the self-organizing map, is proposed for on-line signal trend identification. Trends are categorized at each incoming signal as steady-state, increasing and decreasing, while they are further classified according to characteristics such signal shape and rate of change. Tests with model-generated signals illustrate the ability of the self-organizing map to accurately and reliably perform on-line trend identification in terms of both detection and classification. The proposed methodology has been found robust to the presence of white noise

  7. On line routing per mobile phone

    DEFF Research Database (Denmark)

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology....... Additionally it is of utmost importance that the employed communication system is suitable integrated with the firm’s enterprise application system and business processes. On basis of a case study, we describe in this paper a system that is cheap and easy to implement due to the use of simple mobile phones...

  8. On-line atomic data access

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, D.R. [Oak Ridge National Lab., TN (United States); Nash, J.K. [Lawrence Livermore National Lab., CA (United States)

    1996-04-01

    The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser- produced plasma research, and plasma processing. Modern computer database and communications technology nables this data to be placed on-line and obtained by users of the Internet. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

  9. Electrical conductivity of chromate conversion coating on electrodeposited zinc

    International Nuclear Information System (INIS)

    Tencer, Michal

    2006-01-01

    For certain applications of galvanized steel protected with conversion coatings it is important that the surface is electrically conductive. This is especially important with mating surfaces for electromagnetic compatibility. This paper addresses electrical conductivity of chromate conversion coatings. A cross-matrix study using different zinc plating techniques by different labs showed that the main deciding factor is the type of zinc-plating bath used rather than the subsequent chromating process. Thus, chromated zinc plate electrodeposited from cyanide baths is non-conductive while that from alkaline (non-cyanide) and acid baths is conductive, even though the plate from all the bath types is conductive before conversion coating. The results correlate well with the microscopic structure of the surfaces as observed with scanning electron microscopy (SEM) and could be further corroborated and rationalized using EDX and Auger spectroscopies

  10. Measuring chromatic aberrations in imaging systems using plasmonic nanoparticles.

    Science.gov (United States)

    Gennaro, Sylvain D; Roschuk, Tyler R; Maier, Stefan A; Oulton, Rupert F

    2016-04-01

    We demonstrate a method to measure chromatic aberrations of microscope objectives with metallic nanoparticles using white light. Extinction spectra are recorded while scanning a single nanoparticle through a lens's focal plane. We show a direct correlation between the focal wavelength and the longitudinal chromatic focal shift through our analysis of the variations between the scanned extinction spectra at each scan position and the peak extinction over the entire scan. The method has been tested on achromat and apochromat objectives using aluminum disks varying in size from 260-520 nm. Our method is straightforward, robust, low cost, and broadband with a sensitivity suitable for assessing longitudinal chromatic aberrations in high-numerical-aperture apochromatic corrected lenses.

  11. The effect of chromatic decoherence on transverse injection oscillation damping

    International Nuclear Information System (INIS)

    Jackson, G.P.

    1993-01-01

    In order to eliminate or reduce transverse emittance growth during transfers between accelerators, transverse damper systems are used to eliminate residual dipole oscillations before phase space dilution takes place. In transfers where the target accelerator has high chromaticity or the beam has a large momentum spread, phase space dilution due to chromatic decoherence can take place on a scale short compared to the damping time of the transverse injection oscillation damper. The effect of the damper on the beam phase space is not clear while the coherent oscillation is suppressed by this decoherence. The purpose of this paper is to quantify the effectiveness of dampers at eliminating emittance blowup at transfers in the presence of chromatic decoherence

  12. Low chromatic aberration hexapole for molecular state selection

    International Nuclear Information System (INIS)

    Ke, Yi; Deng, Xiao-Bing; Hu, Zhong-Kun

    2016-01-01

    In molecular beam state-selection experiments, the electrostatic hexapole acts as an optical lens, imaging molecules from the source to the focus. The molecular longitudinal velocity spread induces the phenomenon of chromatic aberration, which will reduce the state-selection purity. We propose a scheme which can effectively reduce the chromatic aberration by changing the hexapole voltage operating manner. The hexapole is already charged before molecules arrive at the entrance of the hexapole. When molecules are completely inside the hexapole, the voltage is switched off rapidly at an appropriate time. In this manner, faster molecules travel a longer hexapole focusing region than slower molecules. Therefore the focusing positions of molecules with different velocities become close. Numerical trajectory simulations of molecular state selection are carried out, and the results show that this low chromatic aberration hexapole can significantly improve the state purity from 46.2% to 87.0%. (paper)

  13. Second order chromaticity of the interaction regions in the collider

    International Nuclear Information System (INIS)

    Sen, T.; Syphers, M.J.

    1993-01-01

    The collider in the SSC has large second order chromaticity (ξ 2 ) with the interaction regions (IRs) contributing substantially to it. The authors calculate the general expression for ξ 2 in a storage ring and find that it is driven by the first order chromatic beta wave. Specializing to the interaction regions, they show that ξ 2 is a minimum when the phase advance (Δμ IP -IP) between adjacent interaction points is an odd multiple of π/2 and both IRs are identical. In this case the first order chromatic beta wave is confined within the IRs. Conversely, ξ 2 is large either if δμ IP -IP = (2n + 1)π/2 and the two IRs are very far from equality or if the two IRs are equal but Δμ IP -IP = nπ

  14. Correcting the Chromatic Aberration in Barrel Distortion of Endoscopic Images

    Directory of Open Access Journals (Sweden)

    Y. M. Harry Ng

    2003-04-01

    Full Text Available Modern endoscopes offer physicians a wide-angle field of view (FOV for minimally invasive therapies. However, the high level of barrel distortion may prevent accurate perception of image. Fortunately, this kind of distortion may be corrected by digital image processing. In this paper we investigate the chromatic aberrations in the barrel distortion of endoscopic images. In the past, chromatic aberration in endoscopes is corrected by achromatic lenses or active lens control. In contrast, we take a computational approach by modifying the concept of image warping and the existing barrel distortion correction algorithm to tackle the chromatic aberration problem. In addition, an error function for the determination of the level of centroid coincidence is proposed. Simulation and experimental results confirm the effectiveness of our method.

  15. Mapping chromatic pathways in the Drosophila visual system.

    Science.gov (United States)

    Lin, Tzu-Yang; Luo, Jiangnan; Shinomiya, Kazunori; Ting, Chun-Yuan; Lu, Zhiyuan; Meinertzhagen, Ian A; Lee, Chi-Hon

    2016-02-01

    In Drosophila, color vision and wavelength-selective behaviors are mediated by the compound eye's narrow-spectrum photoreceptors R7 and R8 and their downstream medulla projection (Tm) neurons Tm5a, Tm5b, Tm5c, and Tm20 in the second optic neuropil or medulla. These chromatic Tm neurons project axons to a deeper optic neuropil, the lobula, which in insects has been implicated in processing and relaying color information to the central brain. The synaptic targets of the chromatic Tm neurons in the lobula are not known, however. Using a modified GFP reconstitution across synaptic partners (GRASP) method to probe connections between the chromatic Tm neurons and 28 known and novel types of lobula neurons, we identify anatomically the visual projection neurons LT11 and LC14 and the lobula intrinsic neurons Li3 and Li4 as synaptic targets of the chromatic Tm neurons. Single-cell GRASP analyses reveal that Li4 receives synaptic contacts from over 90% of all four types of chromatic Tm neurons, whereas LT11 is postsynaptic to the chromatic Tm neurons, with only modest selectivity and at a lower frequency and density. To visualize synaptic contacts at the ultrastructural level, we develop and apply a "two-tag" double-labeling method to label LT11's dendrites and the mitochondria in Tm5c's presynaptic terminals. Serial electron microscopic reconstruction confirms that LT11 receives direct contacts from Tm5c. This method would be generally applicable to map the connections of large complex neurons in Drosophila and other animals. © 2015 Wiley Periodicals, Inc.

  16. Stereo chromatic contrast sensitivity model to blue-yellow gratings.

    Science.gov (United States)

    Yang, Jiachen; Lin, Yancong; Liu, Yun

    2016-03-07

    As a fundamental metric of human visual system (HVS), contrast sensitivity function (CSF) is typically measured by sinusoidal gratings at the detection of thresholds for psychophysically defined cardinal channels: luminance, red-green, and blue-yellow. Chromatic CSF, which is a quick and valid index to measure human visual performance and various retinal diseases in two-dimensional (2D) space, can not be directly applied into the measurement of human stereo visual performance. And no existing perception model considers the influence of chromatic CSF of inclined planes on depth perception in three-dimensional (3D) space. The main aim of this research is to extend traditional chromatic contrast sensitivity characteristics to 3D space and build a model applicable in 3D space, for example, strengthening stereo quality of 3D images. This research also attempts to build a vision model or method to check human visual characteristics of stereo blindness. In this paper, CRT screen was clockwise and anti-clockwise rotated respectively to form the inclined planes. Four inclined planes were selected to investigate human chromatic vision in 3D space and contrast threshold of each inclined plane was measured with 18 observers. Stimuli were isoluminant blue-yellow sinusoidal gratings. Horizontal spatial frequencies ranged from 0.05 to 5 c/d. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. According to the relationship between spatial frequency of inclined plane and horizontal spatial frequency, the chromatic contrast sensitivity characteristics in 3D space have been modeled based on the experimental data. The results show that the proposed model can well predicted human chromatic contrast sensitivity characteristics in 3D space.

  17. The effect of chromate on IGSCC in boiling water reactors - a SSRT study

    International Nuclear Information System (INIS)

    Ullberg, M.

    1992-01-01

    The effect of chromate on IGSCC in Type 304 stainless steel was investigated using the Slow Strain Rate Technique (SSRT). It was found that low concentrations of chromate raises the corrosion potential of SS and causes IGSCC. The effect of chromate was compared to that of the main oxidant in BWRs, hydrogen peroxide. Chromate was found to have less tendency than hydrogen peroxide, at one and the same corrosion potential, to cause IGSCC in SSRT tests. This is interpreted as due to chromate being a better anodic inhibitor than hydrogen peroxide. As a consequence, initiation of IGSCC is slower in the presence of chromate. At least during normal water chemistry, chromate is a secondary oxidant in all of the BWR reactor coolant system. The ECP is then determined by the primary oxidant, hydrogen peroxide. Therefore, the chromate transients which may occur in BWR reactor coolant systems should have no significant effect on IGSCC

  18. Effect of radioactive chromate on the corrosion and polarisation of mild steel in sodium chloride solution

    International Nuclear Information System (INIS)

    Subramanyan, N.; Ramakrishnaiah, K.; Iyer, S.V.; Kapali, V.

    1980-01-01

    Corrosion tests of mild steel in 0.01% sodium chloride containing radioactive chromate and non-radioactive chromate have been carried out. It has been observed that the labelled sodium chromate has a deleterious effect on the inhibitive action of non-radioactive chromate. The effect of radioactive chromate on the potentiostatic polarization of m.s. in sodium chloride solution containing non-radioactive sodium chromate has also been studied. It is observed that both the cathodic and the anodic polarisation of the metal is diminished in the presence of radioactive chromate. The behaviour of the system in the presence of radioactive chromate is attributed both to the action of depolarisers produced by radiolysis of water and to the effect of gamma radiation on the metal. (author)

  19. A nonlinear analysis of the EHF booster

    International Nuclear Information System (INIS)

    Colton, E.P.; Shi, D.

    1987-01-01

    We have analyzed particle motion at 1.2 GeV with assumption of nonlinearities arising from non-linear space charge forces and from the lattice sextupoles which are tuned to cancel the machine chromaticity. In the first case the motion is as expected and there are no problems as long as the x and y betatron tunes are separated by an integer or more. In the second case the motion is stable so long as the betatron amplitudes do not exceed values corresponding to beam normalized emittance of 100 mm-mr; when this occurs the effects of fifth-order betatron resonances are observed. 3 refs

  20. On-line monitoring for calibration reduction

    International Nuclear Information System (INIS)

    Hoffmann, Mario; Gran, Frauke Schmitt; Thunem, Harald P-J.

    2004-04-01

    On-Line Monitoring (OLM) of a channel's calibration state evaluates instrument channel performance by assessing its consistency with other plant indications. Industry and experience at several plants has shown this overall approach to be very effective in identifying instrument channels that are exhibiting degrading or inconsistent performance characteristics. The Halden Reactor Project has developed the signal validation system PEANO, which can be used to assist with the tasks of OLM. To further enhance the PEANO System for use as a calibration reduction tool, the following two additional modules have been developed; HRP Prox, which performs pre-processing and statistical analysis of signal data, Batch Monitoring Module (BMM), which is an off-line batch monitoring and reporting suite. The purpose and functionality of the HRP Prox and BMM modules are discussed in this report, as well as the improvements made to the PEANO Server to support these new modules. The Halden Reactor Project has established a Halden On-Line Monitoring User Group (HOLMUG), devoted to the discussion and implementation of on-line monitoring techniques in power plants. It is formed by utilities, vendors, regulatory bodies and research institutes that meet regularly to discuss implementation aspects of on-line monitoring, technical specification changes, cost-benefit analysis and regulatory issues. (Author)

  1. SPIRES I: on-line search guide

    International Nuclear Information System (INIS)

    Addis, L.

    1975-06-01

    SPIRES I is the first generation of the on-line Stanford Public Information Retrieval System. Designed as a prototype system, SPIRES I was later moved to the SLAC computing facility where it has been routinely available to SLAC users in the field of high-energy physics. The scope and use of the SPIRES I system are described in this manual

  2. HOPI: on-line injection optimization program

    International Nuclear Information System (INIS)

    LeMaire, J.L.

    1977-01-01

    A method of matching the beam from the 200 MeV linac to the AGS without the necessity of making emittance measurements is presented. An on-line computer program written on the PDP10 computer performs the matching by modifying independently the horizontal and vertical emittance. Experimental results show success with this method, which can be applied to any matching section

  3. Chromatic correction in the SLC bunch length compressors

    International Nuclear Information System (INIS)

    Adolphsen, C.E.; Emma, P.J.; Fieguth, T.H.; Spence, W.L.

    1991-06-01

    The SLC Ring to Linac (RTL) transport lines employ intense bending and strong transverse focusing to produce the momentum compaction needed for bunch length compression prior to S-band acceleration. In the presence of the large rf induced energy spread needed for compression the consequent chromatic effects -- viz. the variation with energy of residual output dispersion and of the RTL transfer matrix, threaten to destroy the small emittances produced by the damping rings. We report on the tuning methods that have been developed and used to implement the sextupole based chromatic correction scheme. 6 refs., 4 figs

  4. Chromatic aberrations of electrostatic axisymmetric lenses produced by circular cylinders

    International Nuclear Information System (INIS)

    Baranova, L.A.; Ul'yanova, N.S.; Yavor, S.Ya.

    1989-01-01

    Ion beams both to test material and for technological processes have being used lately in science and technology more and more. Electrostatic lenses are used, as a rule, for such beam production. Coefficients of chromatic aberrration for a wide range of changes in lense parameters are calculated on the basis of analytical expressions to determine the potential in immerse and isolated lenses. The chromatic aberration coefficient is presented as a polynomial according to the degrees of reverse increase, that permits to calculate a circle of blurring of subject arbitrary position

  5. Effect of pressure on the radiation annealing of recoil atoms in chromates

    International Nuclear Information System (INIS)

    Stamouli, M.I.

    1986-01-01

    The effect of pressure on the annealing of recoil atoms by gamma radiation in neutron irradiated potassium chromate, ammonium chromate and ammonium dichromate was studied. In potassium chromate the pressure applied before the gamma-irradiation was found to retard the radiation annealing process. In ammonium chromate and ammonium dichromate the radiation annealing was found to be enhanced in the compressed samples in comparison to the noncompressed ones. (author)

  6. Toxicokinetics of hexavalent chromium in the rat after intratracheal administration of chromates of different solubilities

    NARCIS (Netherlands)

    Bragt, P.C.; Dura, E.A. van

    1983-01-01

    The kinetics of chromium in the rat after a single intratracheal dose of sodium, zinc or lead 51Cr-chromate have been investigated. Sodium chromate and the less soluble zinc chromate were absorbed into the blood and this resulted in increased excretion of chromium into the urine. The insoluble lead

  7. Study of Chromatic parameters of Line, Total, Middle graphs and Graph operators of Bipartite graph

    Science.gov (United States)

    Nagarathinam, R.; Parvathi, N.

    2018-04-01

    Chromatic parameters have been explored on the basis of graph coloring process in which a couple of adjacent nodes receives different colors. But the Grundy and b-coloring executes maximum colors under certain restrictions. In this paper, Chromatic, b-chromatic and Grundy number of some graph operators of bipartite graph has been investigat

  8. Closure plan for the Test Area North-726 chromate water storage and Test Area North-726A chromate treatment units

    International Nuclear Information System (INIS)

    Smith, P.J.; Van Brunt, K.M.

    1992-11-01

    This document describes the proposed plan for closure of the Test Area North-726 chromate water storage and Test Area North-726A chromate treatment units at the Idaho National Engineering Laboratory in accordance with the Resource Conservation and Recovery Act interim status closure requirements. The location, size, capacity, and history of the units are described, and their current status is discussed. The units will be closed by treating remaining waste in storage, followed by thorough decontamination of the systems. Sufficient sampling and analysis, and documentation of all activities will be performed to demonstrate clean closure

  9. Revisiting Cross-Channel Information Transfer for Chromatic Aberration Correction

    KAUST Repository

    Sun, Tiancheng; Peng, Yifan; Heidrich, Wolfgang

    2017-01-01

    Image aberrations can cause severe degradation in image quality for consumer-level cameras, especially under the current tendency to reduce the complexity of lens designs in order to shrink the overall size of modules. In simplified optical designs, chromatic aberration can be one of the most significant causes for degraded image quality, and it can be quite difficult to remove in post-processing, since it results in strong blurs in at least some of the color channels. In this work, we revisit the pixel-wise similarity between different color channels of the image and accordingly propose a novel algorithm for correcting chromatic aberration based on this cross-channel correlation. In contrast to recent weak prior-based models, ours uses strong pixel-wise fitting and transfer, which lead to significant quality improvements for large chromatic aberrations. Experimental results on both synthetic and real world images captured by different optical systems demonstrate that the chromatic aberration can be significantly reduced using our approach.

  10. Effects of visual attention on chromatic and achromatic detection sensitivities.

    Science.gov (United States)

    Uchikawa, Keiji; Sato, Masayuki; Kuwamura, Keiko

    2014-05-01

    Visual attention has a significant effect on various visual functions, such as response time, detection and discrimination sensitivity, and color appearance. It has been suggested that visual attention may affect visual functions in the early visual pathways. In this study we examined selective effects of visual attention on sensitivities of the chromatic and achromatic pathways to clarify whether visual attention modifies responses in the early visual system. We used a dual task paradigm in which the observer detected a peripheral test stimulus presented at 4 deg eccentricities while the observer concurrently carried out an attention task in the central visual field. In experiment 1, it was confirmed that peripheral spectral sensitivities were reduced more for short and long wavelengths than for middle wavelengths with the central attention task so that the spectral sensitivity function changed its shape by visual attention. This indicated that visual attention affected the chromatic response more strongly than the achromatic response. In experiment 2 it was obtained that the detection thresholds increased in greater degrees in the red-green and yellow-blue chromatic directions than in the white-black achromatic direction in the dual task condition. In experiment 3 we showed that the peripheral threshold elevations depended on the combination of color-directions of the central and peripheral stimuli. Since the chromatic and achromatic responses were separately processed in the early visual pathways, the present results provided additional evidence that visual attention affects responses in the early visual pathways.

  11. Strong oriented chromatic number of planar graphs without short cycles

    Directory of Open Access Journals (Sweden)

    Mickaël Montassier

    2008-01-01

    Full Text Available Let M be an additive abelian group. A strong oriented coloringof an oriented graph G is a mapping φ from V(G to M such that (1 φ(u ≠ φ(v whenever uv is an arc in G and (2 φ(v - φ(u ≠ -(φ(t - φ(z whenever uv and zt are two arcs in G. We say that G has a M-strong-oriented coloring. The strong oriented chromatic number of an oriented graph, denoted by χ s (G, is the minimal order of a group M, such that G has M-strong-oriented coloring. This notion was introduced by Nešetřil and Raspaud. In this paper, we pose the following problem: Let i ≥ 4 be an integer. Let G be an oriented planar graph without cycles of lengths 4 to i. Which is the strong oriented chromatic number of G ? Our aim is to determine the impact of triangles on the strong oriented coloring. We give some hints of answers to this problem by proving that: (1 the strong oriented chromatic number of any oriented planar graph without cycles of lengths 4 to 12 is at most 7, and (2 the strong oriented chromatic number of any oriented planar graph without cycles of length 4 or 6 is at most 19.

  12. On the size of edge chromatic 5-critical graphs

    Directory of Open Access Journals (Sweden)

    K. Kayathri

    2017-04-01

    Full Text Available In this paper, we study the size of edge chromatic 5-critical graphs in several classes of 5-critical graphs. In most of the classes of 5-critical graphs in this paper, we have obtained their exact size and in the other classes of 5-critical graphs, we give new bounds on their number of major vertices and size.

  13. Totally odd K-4-subdivisions in 4-chromatic graphs

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2001-01-01

    We prove the conjecture made by Bjarne Toft in 1975 that every 4-chromatic graph contains a subdivision of K-4 in which each edge of K-4 corresponds to a path of odd length. As an auxiliary result we characterize completely the subspace of the cycle space generated by all cycles through two fixed...

  14. Refractive and diffractive neutron optics with reduced chromatic aberration

    DEFF Research Database (Denmark)

    Poulsen, Stefan Othmar; Poulsen, Henning Friis; Bentley, P.M.

    2014-01-01

    by the use of optics for focusing and imaging. Refractive and diffractive optical elements, e.g. compound refractive lenses and Fresnel zone plates, are attractive due to their low cost, and simple alignment. These optical elements, however, suffer from chromatic aberration, which limit their effectiveness...

  15. Reduced Chromatic Discrimination in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Franklin, Anna; Sowden, Paul; Notman, Leslie; Gonzalez-Dixon, Melissa; West, Dorotea; Alexander, Iona; Loveday, Stephen; White, Alex

    2010-01-01

    Atypical perception in Autism Spectrum Disorders (ASD) is well documented (Dakin & Frith, 2005). However, relatively little is known about colour perception in ASD. Less accurate performance on certain colour tasks has led some to argue that chromatic discrimination is reduced in ASD relative to typical development (Franklin, Sowden, Burley,…

  16. The hot-atom chemistry of crystalline chromates. Chapter 8

    International Nuclear Information System (INIS)

    Collins, C.H.; Collins, K.E.

    1979-01-01

    Chromates in general and potassium chromate in particular, have been attractive as compounds for hot-atom chemical study because of the favourable nuclear properties of chromium, the great thermal and radiation stability of the compounds, the apparent structural simplicity of the crystals and the presumed known and simple chemistry of the expected recoil products. A wealth of information has been accumulated over the past 25 years, from which the anticipation of a straightforward chemistry has given way to an expanding realization that these systems are actually quite complex. More solid-state hot-atom chemical studies have dealt with potassium chromate than with any other compound. Thus, a major fraction of this review is given to this compound. The emphasis is on recent literature and on the pesent views of phenomena which affect the chemical fate of recoil chromium atoms in chromates. Many other data are tabulated so that the interested reader can speculate independently on the results of a wide variety of experiments. (Auth.)

  17. On threshold mechanisms for achromatic and chromatic vision

    NARCIS (Netherlands)

    Bouman, M.A.; Walraven, P.L.

    1972-01-01

    On the basis of measurements of the achromatic zone for red light in the fovea and for green light in the periphery, a discussion is given on the possible difference in threshold mechanisms for the achromatic (scotopic) and chromatic (photopic) retinal systems. A specific suggestion for this

  18. Chromatic roots and minor-closed families of graphs

    DEFF Research Database (Denmark)

    Perrett, Thomas

    2016-01-01

    Given a minor-closed class of graphs G, what is the in mum of the non-trivial roots of the chromatic polynomial of G ε G? When G is the class of all graphs, the answer is known to be 32/27. We answer this question exactly for three minor-closed classes of graphs. Furthermore, we conjecture precis...

  19. Electrochemical reduction of dilute chromate solutions on carbon felt electrodes

    NARCIS (Netherlands)

    Frenzel, Ines; Frenzel, I.; Holdik, Hans; Barmashenko, Vladimir; Stamatialis, Dimitrios; Wessling, Matthias

    2006-01-01

    Carbon felt is a potential material for electrochemical reduction of chromates. Very dilute solutions may be efficiently treated due to its large specific surface area and high porosity. In this work, the up-scaling of this technology is investigated using a new type of separated cell and

  20. The chromatic correction in RHIC [Relativistic Heavy Ion Collider

    International Nuclear Information System (INIS)

    Lee, S.Y.; Dell, G.F.; Hahn, H.; Parzen, G.

    1987-01-01

    The scheme for the correction of chromatic effects in the Relativistic Heavy Ion Collider at BNL is discussed. This scheme uses six families of sextupoles excited by four independent power supplies, and provides adequate control of linear and quadratic terms in the tune vs momentum dependence and reduces the variation of the betatron amplitude, vs momentum

  1. Molecular basis of chromatic adaptation in pennate diatom Phaeodactylum tricornutum

    Czech Academy of Sciences Publication Activity Database

    Herbstová, Miroslava; Bína, David; Koník, P.; Gardian, Zdenko; Vácha, František; Litvín, Radek

    2015-01-01

    Roč. 1847, 6-7 (2015), s. 534-543 ISSN 0005-2728 R&D Projects: GA ČR GBP501/12/G055 Institutional support: RVO:60077344 Keywords : Chromatic adaptation * Diatom * Heterokonta * Light harvesting antenna Subject RIV: CE - Biochemistry Impact factor: 4.864, year: 2015

  2. Revisiting Cross-Channel Information Transfer for Chromatic Aberration Correction

    KAUST Repository

    Sun, Tiancheng

    2017-12-25

    Image aberrations can cause severe degradation in image quality for consumer-level cameras, especially under the current tendency to reduce the complexity of lens designs in order to shrink the overall size of modules. In simplified optical designs, chromatic aberration can be one of the most significant causes for degraded image quality, and it can be quite difficult to remove in post-processing, since it results in strong blurs in at least some of the color channels. In this work, we revisit the pixel-wise similarity between different color channels of the image and accordingly propose a novel algorithm for correcting chromatic aberration based on this cross-channel correlation. In contrast to recent weak prior-based models, ours uses strong pixel-wise fitting and transfer, which lead to significant quality improvements for large chromatic aberrations. Experimental results on both synthetic and real world images captured by different optical systems demonstrate that the chromatic aberration can be significantly reduced using our approach.

  3. Educational On-Line Gaming Propensity

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana; Kirchner, Kathrin

    2014-01-01

    Educational on-line games are promising for new generations of students who are grown up digital. Th e new generations of students are technology savvy and spend lots of time on the web and on social networks. Based on an exploratory study, this article investigates the factors that infl uence...... students’ willingness to participate in serious games for teaching/learning. Th is study investigates the relationship between students’ behavior on Facebook, Facebook games, and their attitude toward educational on-line games. Th e results of the study reveal that the early adopters of educational games...... are likely to be students, who are young, have only a few Facebook connections, who currently play Facebook game(s). Furthermore, the study emphasizes that there may be differences between students coming from various countries....

  4. Trends in on-line data processing

    International Nuclear Information System (INIS)

    Masetti, M.

    1981-01-01

    The developement of integrated circuits has been characterized by an exponential growth of gates on a single chip that will still continue in the coming years. In parallel the price per bit is dropping down with more or less the same law. As a consequence of this a few statements can be made: The present 16-bit minicomputer in a small configuration is going to be substituted by a 16-bit microcomputer, and the 16-bit microcomputer in a powerful configuration by a 32-bit midi having also a virtual memory facility. Fully programmable or microcoded powerful devices like the LASS hardware processor or MICE, will allow an efficient on-line filter. Higher computing speed can be achieved by a multiprocessor configuration which can be insensitive to hardware failures. Therefore we are moving towards an integrated on-line computing system with much higher computing power than now and the present distinction between on-line and off-line will no longer be so sharp. As more processing can be performed on-line, fast high quality feed-back can be provided for the experiment. In the years to come the trend towards more processing power, at a lower price, and assembled in the same hardware volume will continue for at least five years; at the same time the future large high-energy physics experiments at LEP will be carried out within a wide international collaboration. In this environment methods must be found for a large fraction of the work to be distributed amongst the collaborators. To accomplish this aim it is necessary to introduce common standard practices concerning both hardware and software, in such a way that the seperate parts, developed by the collaborators, will be plug-compatible. (orig.)

  5. New Trends in on-line Marketing

    OpenAIRE

    Palkovič, Lukáš

    2011-01-01

    This bachelor thesis deals with new trend of internet marketing, it focuses especially on viral marketing. The theoretical part charasterizes the process of viral campaigns, furthermore deals with the components and aspects of on-line environment. Another separated chapter presents social networks, their place in viral marketing and at last but not least the viral video making process. The practical part contains different analyses of specific viral campaigns. The next and equally the last pa...

  6. On-Line Maintenance Methodology Development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Won; Kim, Jae Ho; Jae, Moo Sung [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    Most of domestic maintenance activities for nuclear power plants are performed while overhaul. Therefore, On-Line Maintenance (OLM) is one of the proper risks informed application techniques for diffusing maintenance burden during overhaul with safety of the plant is secured. The NUMARC 93-01 (Rev.3) presents the OLM state of the art and it provides methodology. This study adopts NUMARC 93-01 (Rev.3) and present OLM. The reference component is Emergency Diesel Generator (EDG) of Ulchin 3, 4

  7. Functionalized granular activated carbon and surface complexation with chromates and bi-chromates in wastewater

    International Nuclear Information System (INIS)

    Singha, Somdutta; Sarkar, Ujjaini; Luharuka, Pallavi

    2013-01-01

    Cr(VI) is present in the aqueous medium as chromate (CrO 4 2− ) and bi-chromate (HCrO 4 − ). Functionalized granular activated carbons (FACs) are used as adsorbents in the treatment of wastewaters containing hexavalent chromium. The FACs are prepared by chemical modifications of granular activated carbons (GACs) using functionalizing agents like HNO 3 , HCl and HF. The Brunauer, Emmett and Teller surface areas of FAC-HCl (693.5 m 2 /g), FAC-HNO 3 (648.8 m 2 /g) and FAC-HF (726.2 m 2 /g) are comparable to the GAC (777.7 m 2 /g). But, the adsorption capacity of each of the FAC-HNO 3 , FAC-HCl and FAC-HF is found to be higher than the GAC. The functional groups play an important role in the adsorption process and pH has practically no role in this specific case. The FACs have hydrophilic protonated external surfaces in particular, along with the functional surface sites capable to make complexes with the CrO 4 2− and HCrO 4 − present. Surface complex formation is maximized in the order FAC-HNO 3 > FAC-HF > FAC-HCl, in proportion to the total surface acidity. This is also confirmed by the well-known pseudo second-order kinetic model. Physi-sorption equilibrium isotherms are parameterized by using standard Freundlich and Langmuir models. Langmuir fits better. The formation of surface complexes with the functional groups and hexavalent chromium is also revealed in the images of field emission scanning electron micrograph; energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy analysis after adsorption. The intra-particle diffusion is not the only rate-controlling factor. The Boyd's film diffusion model fits very well with R 2 as high as 98.1% for FAC-HNO 3 . This result demonstrates that the functionalization of the GAC by acid treatments would increase the diffusion rate, predominantly with a boundary layer diffusion effect. - Highlights: ► Physico-chemical adsorption using functionalized activated carbon (FACs) is applied. ► FACs

  8. IMPACT OF ATMOSPHERIC CHROMATIC EFFECTS ON WEAK LENSING MEASUREMENTS

    International Nuclear Information System (INIS)

    Meyers, Joshua E.; Burchat, Patricia R.

    2015-01-01

    Current and future imaging surveys will measure cosmic shear with statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We use analytic and computational techniques to study the impact on shape measurements of two atmospheric chromatic effects for ground-based surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope (LSST): (1) atmospheric differential chromatic refraction and (2) wavelength dependence of seeing. We investigate the effects of using the point-spread function (PSF) measured with stars to determine the shapes of galaxies that have different spectral energy distributions than the stars. We find that both chromatic effects lead to significant biases in galaxy shape measurements for current and future surveys, if not corrected. Using simulated galaxy images, we find a form of chromatic “model bias” that arises when fitting a galaxy image with a model that has been convolved with a stellar, instead of galactic, PSF. We show that both forms of atmospheric chromatic biases can be predicted (and corrected) with minimal model bias by applying an ordered set of perturbative PSF-level corrections based on machine-learning techniques applied to six-band photometry. Catalog-level corrections do not address the model bias. We conclude that achieving the ultimate precision for weak lensing from current and future ground-based imaging surveys requires a detailed understanding of the wavelength dependence of the PSF from the atmosphere, and from other sources such as optics and sensors. The source code for this analysis is available at https://github.com/DarkEnergyScienceCollaboration/chroma

  9. IMPACT OF ATMOSPHERIC CHROMATIC EFFECTS ON WEAK LENSING MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Joshua E.; Burchat, Patricia R., E-mail: jmeyers314@gmail.com [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2015-07-10

    Current and future imaging surveys will measure cosmic shear with statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We use analytic and computational techniques to study the impact on shape measurements of two atmospheric chromatic effects for ground-based surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope (LSST): (1) atmospheric differential chromatic refraction and (2) wavelength dependence of seeing. We investigate the effects of using the point-spread function (PSF) measured with stars to determine the shapes of galaxies that have different spectral energy distributions than the stars. We find that both chromatic effects lead to significant biases in galaxy shape measurements for current and future surveys, if not corrected. Using simulated galaxy images, we find a form of chromatic “model bias” that arises when fitting a galaxy image with a model that has been convolved with a stellar, instead of galactic, PSF. We show that both forms of atmospheric chromatic biases can be predicted (and corrected) with minimal model bias by applying an ordered set of perturbative PSF-level corrections based on machine-learning techniques applied to six-band photometry. Catalog-level corrections do not address the model bias. We conclude that achieving the ultimate precision for weak lensing from current and future ground-based imaging surveys requires a detailed understanding of the wavelength dependence of the PSF from the atmosphere, and from other sources such as optics and sensors. The source code for this analysis is available at https://github.com/DarkEnergyScienceCollaboration/chroma.

  10. Chromate ion-exchange study for cooling water

    International Nuclear Information System (INIS)

    Sengupta, A.K.

    1985-01-01

    In spite of high chromate selectivity, the ion-exchange process for Cr(IV) recovery from cooling tower blowdown is yet to be commercially popular. Possible degradation of the ion-exchange resin by the oxidative action of Cr(IV) during ion exchange has been considered as the prime obstacle. Resins have been manufactured with fairly acceptable properties to withstand both physical attrition and chemical oxidation. Demonstrated during the course of this research is early, gradual Cr(VI) breakthrough during fixed-bed column runs at acidic pH in the presence of competing sulfate and chloride anions. The advantage of high chromate selectivity is essentially lost due to the early Cr(VI) breakthrough because the column runs are always terminated after a pre-determined level of Cr(VI) has appeared in the treated water. Experimental results provide sufficient evidence that this is not due to poor column kinetics or electrolyte penetration. The chromate ion-exchange mechanism has been investigated in order to explain the foregoing anomalies for the chromate-exchange process. The knowledge of chromate ion-exchange mechanism has been used to overcome the shortcoming of gradual Cr(VI) breakthrough. This study shows that: (a) a continuous counter-current ion-exchange system theoretically offers much higher Cr(VI) removal capacity compared to conventional single-unit fixed-bed system for any pre-determined level of Cr(VI) breakthrough; (b) by modifying the resin composition, the gradual Cr(VI) breakthrough can be greatly eliminated

  11. On-line identification of hybrid systems using an adaptive growing and pruning RBF neural network

    DEFF Research Database (Denmark)

    Alizadeh, Tohid

    2008-01-01

    This paper introduces an adaptive growing and pruning radial basis function (GAP-RBF) neural network for on-line identification of hybrid systems. The main idea is to identify a global nonlinear model that can predict the continuous outputs of hybrid systems. In the proposed approach, GAP......-RBF neural network uses a modified unscented kalman filter (UKF) with forgetting factor scheme as the required on-line learning algorithm. The effectiveness of the resulting identification approach is tested and evaluated on a simulated benchmark hybrid system....

  12. Effect of chromate action on morphology of basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Lin Zhang; Zhu Ying; Kalabegishvili, Tamaz L.; Tsibakhashvili, Nelly Y.; Holman, Hoi-Ying

    2006-01-01

    Basalt-inhabiting bacteria isolated from polluted basalts have been demonstrated to be able to tolerate moderate to high concentrations of chromium oxyanions such as chromate. Previous results have shown that macromolecules outside the cell wall of bacteria may play an important role in this survival ability. In this paper, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were applied to study the chromate-induced morphological changes in chromate-resistant basalt-inhabiting Arthrobacter K-2 and K-4, which were isolated from the Republic of Georgia. The surfaces of both strains changed in the presence of chromate. TEM thin sections show that chromate stimulates the appearance of bacteria capsular polysaccharide outside the cell wall, although the chromate concentration does not have a strong effect on the capsular thickness. These results, in conjunction with those reported earlier, provide direct evidence to show that capsular polysaccharides of the bacteria play very important role for the reduction and localization of chromate

  13. On-line neutron activation analyzers

    International Nuclear Information System (INIS)

    Flahaut, V.; Colmon, A.

    1999-01-01

    A neutronic analyser has been designed to determine the composition of the flow of raw materials entering a cement factory on the conveyor belt. This new system gives a reliable analysis of the whole cargo that outdates the sampling or the usual surface analysis based on fluorescence spectrometry. The accuracy is about 1%.The neutrons interact with the materials on an average depth of 25 cm and are absorbed by nuclei, these nuclei produce photons whose energy is characteristic of the chemical element itself. The composition can be deduced by measuring the number of photons emitted and their energy. The analysis is made on-line and can concern the search for about 10 compounds. In the case of cement the list of compounds is: SiO 2 , CaO, Al 2 O 3 , Fe 2 O 3 , MgO, Na 2 O, TiO 2 , S, Mn 2 O 3 , K 2 O, and H 2 O. The neutron generator involves a deuterium ion source whose deuterium ions are accelerated by means of an electrical field and impinge on a tritiated target, the nuclear reactions between deuterium and tritium produce 14 MeV neutrons. This neutron analysing technique can be adapted to any need of on-line composition determination. (A.C.)

  14. Functionalized granular activated carbon and surface complexation with chromates and bi-chromates in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Singha, Somdutta; Sarkar, Ujjaini, E-mail: usarkar@chemical.jdvu.ac.in; Luharuka, Pallavi

    2013-03-01

    Cr(VI) is present in the aqueous medium as chromate (CrO{sub 4}{sup 2−}) and bi-chromate (HCrO{sub 4}{sup −}). Functionalized granular activated carbons (FACs) are used as adsorbents in the treatment of wastewaters containing hexavalent chromium. The FACs are prepared by chemical modifications of granular activated carbons (GACs) using functionalizing agents like HNO{sub 3}, HCl and HF. The Brunauer, Emmett and Teller surface areas of FAC-HCl (693.5 m{sup 2}/g), FAC-HNO{sub 3} (648.8 m{sup 2}/g) and FAC-HF (726.2 m{sup 2}/g) are comparable to the GAC (777.7 m{sup 2}/g). But, the adsorption capacity of each of the FAC-HNO{sub 3}, FAC-HCl and FAC-HF is found to be higher than the GAC. The functional groups play an important role in the adsorption process and pH has practically no role in this specific case. The FACs have hydrophilic protonated external surfaces in particular, along with the functional surface sites capable to make complexes with the CrO{sub 4}{sup 2−} and HCrO{sub 4}{sup −} present. Surface complex formation is maximized in the order FAC-HNO{sub 3} > FAC-HF > FAC-HCl, in proportion to the total surface acidity. This is also confirmed by the well-known pseudo second-order kinetic model. Physi-sorption equilibrium isotherms are parameterized by using standard Freundlich and Langmuir models. Langmuir fits better. The formation of surface complexes with the functional groups and hexavalent chromium is also revealed in the images of field emission scanning electron micrograph; energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy analysis after adsorption. The intra-particle diffusion is not the only rate-controlling factor. The Boyd's film diffusion model fits very well with R{sup 2} as high as 98.1% for FAC-HNO{sub 3}. This result demonstrates that the functionalization of the GAC by acid treatments would increase the diffusion rate, predominantly with a boundary layer diffusion effect. - Highlights: ► Physico

  15. Investigation of the chromate conversion coating on Alclad 2024 aluminium alloy: effect of the pH of the chromate bath

    NARCIS (Netherlands)

    Campestrini, P.; Westing, E.P.M. van; Hovestad, A.; Wit, J.H.W. de

    2002-01-01

    The parameters of the chromate bath, like temperature, pH, and fluoride content, strongly affect the morphology and chemical composition of the chromate conversion coating and as a consequence have a large influence on its corrosion performance. In this paper, electrochemical impedance spectroscopy

  16. Towards Bio-Inspired Chromatic Behaviours in Surveillance Robots

    Directory of Open Access Journals (Sweden)

    Sampath Kumar Karutaa Gnaniar

    2016-09-01

    Full Text Available The field of Robotics is ever growing at the same time as posing enormous challenges. Numerous works has been done in biologically inspired robotics emulating models, systems and elements of nature for the purpose of solving traditional robotics problems. Chromatic behaviours are abundant in nature across a variety of living species to achieve camouflage, signaling, and temperature regulation. The ability of these creatures to successfully blend in with their environment and communicate by changing their colour is the fundamental inspiration for our research work. In this paper, we present dwarf chameleon inspired chromatic behaviour in the context of an autonomous surveillance robot, “PACHONDHI”. In our experiments, we successfully validated the ability of the robot to autonomously change its colour in relation to the terrain that it is traversing for maximizing detectability to friendly security agents and minimizing exposure to hostile agents, as well as to communicate with fellow cooperating robots.

  17. Implementing New Non-Chromate Coatings Systems (Briefing Charts)

    Science.gov (United States)

    2011-02-09

    Initiate Cr6+ authorization process for continued Cr6+ use using the form, Authorization to Use Hexavalent Chromium. YES NO • Approval of...Aluminum and magnesium anodizing • Hard Chrome Plating • Type II conversion coating on aluminum alloys under chromated primer • Type II conversion coating...Elimination of Hexavalent Chromium 80% 5% 14% 1% Type II Type III Type IC Type IC Fatigue Critical 50% 50% Type II Type IC FRC-SE (JAX) Fully Integrated FRC

  18. Chromate abatement in the Y-12 Plant's New Hope Pond

    International Nuclear Information System (INIS)

    DeMonbrum, J.R.; Muenzer, W.A.

    1975-01-01

    Results are reported from a 15-months field study that utilized four nonchromate-based water-treatment programs in 16 low-temperature (less than 100 0 F) cooling towers using corrosion and deposition studies, microbiological control, and plant effluent creek analyses as evaluation parameters. The study succeeded in bringing the chromate content of effluent of the New Hope Pond at the Oak Ridge Y-12 Plant to the limits established by the Environmental Protection Agency. (auth)

  19. Modelling of chromatic contrast for retrieval of wallpaper images

    OpenAIRE

    Gao, Xiaohong W.; Wang, Yuanlei; Qian, Yu; Gao, Alice

    2015-01-01

    Colour remains one of the key factors in presenting an object and consequently has been widely applied in retrieval of images based on their visual contents. However, a colour appearance changes with the change of viewing surroundings, the phenomenon that has not been paid attention yet while performing colour-based image retrieval. To comprehend this effect, in this paper, a chromatic contrast model, CAMcc, is developed for the application of retrieval of colour intensive images, cementing t...

  20. The Role of Luminance and Chromaticity on Symmetry Detection

    Directory of Open Access Journals (Sweden)

    Chia-Ching Wu

    2011-05-01

    Full Text Available We investigated the effect of luminance and chromaticity on symmetry detection with the noise masking paradigm. In each trial, a random dot noise mask was presented in both intervals. A symmetric target was randomly presented in one interval while a random dot control was presented in the other. The orientation of the symmetric axis of the target was either 45°or −45° diagonal. The task of the observer was to determine which interval contained a symmetric target. The dots in both the target and the mask was painted with 1 to 4 colors selected from white, black, red, green, blue and yellow. We measured the target density threshold at various noise densities. Our results showed that when the number of the colors in the images was equal, the thresholds were lower in the luminance conditions than in the chromaticity conditions. In addition, the thresholds decreased with the increment of the number of the colors in the images. This suggests that (1 the luminance symmetry detection mechanism is more sensitive than chromaticity one and (2 that, contrasted to the prediction of an uncertainty model, the diversity in color facilitates symmetry detection.

  1. Joint denoising, demosaicing, and chromatic aberration correction for UHD video

    Science.gov (United States)

    Jovanov, Ljubomir; Philips, Wilfried; Damstra, Klaas Jan; Ellenbroek, Frank

    2017-09-01

    High-resolution video capture is crucial for numerous applications such as surveillance, security, industrial inspection, medical imaging and digital entertainment. In the last two decades, we are witnessing a dramatic increase of the spatial resolution and the maximal frame rate of video capturing devices. In order to achieve further resolution increase, numerous challenges will be facing us. Due to the reduced size of the pixel, the amount of light also reduces, leading to the increased noise level. Moreover, the reduced pixel size makes the lens imprecisions more pronounced, which especially applies to chromatic aberrations. Even in the case when high quality lenses are used some chromatic aberration artefacts will remain. Next, noise level additionally increases due to the higher frame rates. To reduce the complexity and the price of the camera, one sensor captures all three colors, by relying on Color Filter Arrays. In order to obtain full resolution color image, missing color components have to be interpolated, i.e. demosaicked, which is more challenging than in the case of lower resolution, due to the increased noise and aberrations. In this paper, we propose a new method, which jointly performs chromatic aberration correction, denoising and demosaicking. By jointly performing the reduction of all artefacts, we are reducing the overall complexity of the system and the introduction of new artefacts. In order to reduce possible flicker we also perform temporal video enhancement. We evaluate the proposed method on a number of publicly available UHD sequences and on sequences recorded in our studio.

  2. Speed and the coherence of superimposed chromatic gratings.

    Science.gov (United States)

    Bosten, J M; Smith, L; Mollon, J D

    2016-05-01

    On the basis of measurements of the perceived coherence of superimposed drifting gratings, Krauskopf and Farell (1990) proposed that motion is analysed independently in different chromatic channels. They found that two gratings appeared to slip if each modulated one of the two 'cardinal' color mechanisms S/(L+M) and L/(L+M). If the gratings were defined along intermediate color directions, observers reported a plaid, moving coherently. We hypothesised that slippage might occur in chromatic gratings if the motion signal from the S/(L+M) channel is weak and equivalent to a lower speed. We asked observers to judge coherence in two conditions. In one, S/(L+M) and L/(L+M) gratings were physically the same speed. In the other, the two gratings had perceptually matched speeds. We found that the relative incoherence of cardinal gratings is the same whether gratings are physically or perceptually matched in speed. Thus our hypothesis was firmly contradicted. In a control condition, observers were asked to judge the coherence of stationary gratings. Interestingly, the difference in judged coherence between cardinal and intermediate gratings remained as strong as it was when the gratings moved. Our results suggest a possible alternative interpretation of Krauskopf and Farell's result: the processes of object segregation may precede the analysis of the motion of chromatic gratings, and the same grouping signals may prompt object segregation in the stationary and moving cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Evaluation of chromatic cues for trapping Bactrocera tau.

    Science.gov (United States)

    Li, Lei; Ma, Huabo; Niu, Liming; Han, Dongyin; Zhang, Fangping; Chen, Junyu; Fu, Yueguan

    2017-01-01

    Trapping technology based on chromatic cues is an important strategy in controlling Tephritidae (fruit flies). The objectives of this present study were to evaluate the preference of Bactrocera tau for different chromatic cues, and to explore an easy method to print and reproduce coloured paper. Chromatic cues significantly affected the preference of adult B. tau. Wavelengths in the 515-604 nm range were the suitable wavelengths for trapping B. tau. Different-day-old B. tau had different colour preferences. Virtual wavelengths of 595 nm (yellow) and 568 nm (yellowish green) were the optimum wavelengths for trapping 5-7-day-old B. tau and 30-32-day-old B. tau respectively. The trap type and height significantly influenced B. tau attraction efficiency. The number of B. tau on coloured traps hung perpendicular to plant rows was not significantly higher than the number on traps hung parallel to plant rows. The quantisation of colour on the basis of Bruton's wavelength to RGB function can serve as an alternative method for printing and reproducing coloured paper, but a corrected equation should be established between the theoretical wavelength and actual wavelength of coloured paper. Results show that a compound paper coloured yellow (595 nm) and yellowish green (568 nm) installed at 60 and 90 cm above the ground shows the maximum effect for trapping B. tau. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. On line nuclear orientation: opportunity and challenge

    International Nuclear Information System (INIS)

    Stone, N.J.

    1985-01-01

    The development of the on-line nuclear orientation (OLNO) technique is reviewed. The present potential of the technique is discussed in the light of the attainable temperatures, the use of ion implantation and the required isotope flux. Limitations associated with spin-lattice relaxation are considered in some detail and a survey of accessible nuclei is presented. An outline comparison is given between OLNO and other methods for producing orientation of nuclei, for measuring nuclear spins and static moments and for the study of level structure and transition probabilities. The conclusion is drawn that the method in its present form has extensive potential over a wide range of nuclei. Future prospects for in-beam polarisation giving access to nuclei of shorter half lives are referred to briefly. (Auth.)

  5. An on-line diagnostic expert system

    International Nuclear Information System (INIS)

    Felkel, L.

    1987-01-01

    As experience with on-line information systems, experts systems and artificial intelligence tools grows, the authors retreat from the first euphoria that AI could help them solve the problem they were unable to solve with conventional programming. The major effort of the development time goes into building the knowledge-base. There is no such thing as a generic knowledge-base for nuclear power plants as there is, for example, for the diagnosis of a Boeing 747 aircraft. AI-methods, tools and hardware are still in a state which does not optimally lend itself to real-time application. The ability of developing prototype systems to investigate variants otherwise too costly to justify is one advantage that the authors gladly accept. Last, but no least the tools provide a flexible and adaptable user interface (desktop window systems) etc. The development of such tools in a project would be prohibitive and room for experimentation would be limited

  6. On-Line Algorithms and Reverse Mathematics

    Science.gov (United States)

    Harris, Seth

    In this thesis, we classify the reverse-mathematical strength of sequential problems. If we are given a problem P of the form ∀X(alpha(X) → ∃Zbeta(X,Z)) then the corresponding sequential problem, SeqP, asserts the existence of infinitely many solutions to P: ∀X(∀nalpha(Xn) → ∃Z∀nbeta(X n,Zn)). P is typically provable in RCA0 if all objects involved are finite. SeqP, however, is only guaranteed to be provable in ACA0. In this thesis we exactly characterize which sequential problems are equivalent to RCA0, WKL0, or ACA0.. We say that a problem P is solvable by an on-line algorithm if P can be solved according to a two-player game, played by Alice and Bob, in which Bob has a winning strategy. Bob wins the game if Alice's sequence of plays 〈a0, ..., ak〉 and Bob's sequence of responses 〈 b0, ..., bk〉 constitute a solution to P. Formally, an on-line algorithm A is a function that inputs an admissible sequence of plays 〈a 0, b0, ..., aj〉 and outputs a new play bj for Bob. (This differs from the typical definition of "algorithm", though quite often a concrete set of instructions can be easily deduced from A.). We show that SeqP is provable in RCA0 precisely when P is solvable by an on-line algorithm. Schmerl proved this result specifically for the graph coloring problem; we generalize Schmerl's result to any problem that is on-line solvable. To prove our separation, we introduce a principle called Predictk(r) that is equivalent to -WKL0 for standard k, r.. We show that WKL0 is sufficient to prove SeqP precisely when P has a solvable closed kernel. This means that a solution exists, and each initial segment of this solution is a solution to the corresponding initial segment of the problem. (Certain bounding conditions are necessary as well.) If no such solution exists, then SeqP is equivalent to ACA0 over RCA 0 + ISigma02; RCA0 alone suffices if only sequences of standard length are considered. We use different techniques from Schmerl to prove

  7. Software for on-line experiments

    International Nuclear Information System (INIS)

    Ivanchenko, I.M.

    1981-01-01

    A review of nowadays development state of software of on-line electron experiments is presented. The principles of organization of real time systems on second generation computer base are considered. The following methods for projections search are considered: combinator methods, global methods, methods of tracking, methods of a supporting band. The following methods for determining parameter estimates based on the Lorentz equation are analysed: analytical simulation of trajectories, determination of parameters by the iterative method using the technique of calculation of recycled integrals, multidimensional statistical analysis. For the purpose of successful usage and development of software the technique of selfdocumented programs is created and the computer is applied for preparing, revising and circulation of external descriptions which as program complexes are constructed according to the hierarchical principle [ru

  8. On line protection systems for induction motors

    International Nuclear Information System (INIS)

    Colak, I.; Celik, H.; Sefa, I.; Demirbas, S.

    2005-01-01

    Protection of induction motors is very important since they are widely used in industry for many applications due to their high robustness, reliability, low cost and maintenance, high efficiency and long service life. So, protecting these motors is crucial for operations. This paper presents a combined protection approach for induction motors. To achieve this, the electrical values of the induction motor were measured with sensitivity ±1% through a data acquisition card and processed with software developed in Visual C++. An on line protection system for induction motors was achieved easily and effectively. The experimental results have shown that the induction motor was protected against the possible problems faced during the operation. The software developed for this protection provides flexible and reliable media for operators and their motors. It is expected that the motor protection achieved in this study might be faster than the classical techniques and also may be applied to larger motors easily after small modifications of the software

  9. Aprender a innovar: una experiencia on line

    Directory of Open Access Journals (Sweden)

    Joaquín MORENO MARCHAL

    2014-11-01

    Full Text Available La creatividad y la innovación se han convertido en recursos clave en la denominada sociedad del conocimiento, que bien podría ser también llamada sociedad de la innovación. Pero innovar es una actividad compleja, que integra la aplicación de múltiples capacidades, el pensamiento divergente y convergente, la gestión de equipos humanos, la comunicación. Ahora bien, a innovar se puede, y se debe, aprender. Aprender a innovar es un reto y también una obligación para el conjunto del sistema educativo en todos sus niveles. Partiendo de estas consideraciones este trabajo expone una experiencia de aprendizaje de la creatividad y de la innovación a través de un curso totalmente on line basado en la plataforma MOODLE, en el marco del Programa de Formación Permanente de la Universidad de Cádiz. Se presenta un modelo del proceso de innovación, denominado CREALAB, de elaboración propia. Este modelo se ha utilizado como base del proceso de aprendizaje de la creatividad y de la innovación y en el diseño del curso, está organizado en torno a actividades y tiene un carácter iterativo y realimentado. Se presentan además el conjunto del diseño metodológico y los resultados obtenidos en las dos ediciones celebradas hasta el momento. El diseño del curso totalmente on line y los resultados alcanzados permiten estimar un alto potencial de aplicación, tanto a nivel personal como a nivel organizacional.

  10. Chromatic summation and receptive field properties of blue-on and blue-off cells in marmoset lateral geniculate nucleus.

    Science.gov (United States)

    Eiber, C D; Pietersen, A N J; Zeater, N; Solomon, S G; Martin, P R

    2017-11-22

    The "blue-on" and "blue-off" receptive fields in retina and dorsal lateral geniculate nucleus (LGN) of diurnal primates combine signals from short-wavelength sensitive (S) cone photoreceptors with signals from medium/long wavelength sensitive (ML) photoreceptors. Three questions about this combination remain unresolved. Firstly, is the combination of S and ML signals in these cells linear or non-linear? Secondly, how does the timing of S and ML inputs to these cells influence their responses? Thirdly, is there spatial antagonism within S and ML subunits of the receptive field of these cells? We measured contrast sensitivity and spatial frequency tuning for four types of drifting sine gratings: S cone isolating, ML cone isolating, achromatic (S + ML), and counterphase chromatic (S - ML), in extracellular recordings from LGN of marmoset monkeys. We found that responses to stimuli which modulate both S and ML cones are well predicted by a linear sum of S and ML signals, followed by a saturating contrast-response relation. Differences in sensitivity and timing (i.e. vector combination) between S and ML inputs are needed to explain the amplitude and phase of responses to achromatic (S + ML) and counterphase chromatic (S - ML) stimuli. Best-fit spatial receptive fields for S and/or ML subunits in most cells (>80%) required antagonistic surrounds, usually in the S subunit. The surrounds were however generally weak and had little influence on spatial tuning. The sensitivity and size of S and ML subunits were correlated on a cell-by-cell basis, adding to evidence that blue-on and blue-off receptive fields are specialised to signal chromatic but not spatial contrast. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Chromate Reduction in Serratia marcescens Isolated from Tannery Effluent and Potential Application for Bioremediation of Chromate Pollution

    Directory of Open Access Journals (Sweden)

    M.A. Mondaca

    2002-01-01

    Full Text Available Pollution of aquatic systems by heavy metals has resulted in increasing environmental concern because they cannot be biodegraded. One metal that gives reason for concern due to its toxicity is chromium. Cr(VI and Cr(III are the principal forms of chromium found in natural waters. A chromate-resistant strain of the bacterium S. marcescens was isolated from tannery effluent. The strain was able to reduce Cr(VI to Cr(III, and about 80% of chromate was removed from the medium. The reduction seems to occur on the cell surface. Transmission electron microscopic examination of cells revealed that particles were deposited on the outside of bacterial cells. A stable biofilm was formed in less than 10 h, reaching around 1010 cfu attached per milligram of activated carbon. These findings demonstrate that immobilized S. marcescens might be used in industrial waste treatment processes.

  12. Study of chromatic adaptation via neutral white matches on different viewing media.

    Science.gov (United States)

    Zhai, Qiyan; Luo, Ming R

    2018-03-19

    Two experiments were carried out to study the neutral white and the chromatic adaptation in human vision and color science. After matching neutral whites under different illuminants using both surface and self-luminous colors, the result were used to verify the previous study about the chromatic adaptation. Not all the white illuminants were found neutral even the adaptation time is long. The baseline illuminant of the two-step chromatic adaptation transform was found as the illuminant with the same chromaticity of the neutral white under it and depended on viewing medium in the present study. The results were also used as corresponding colors to derive models of the effective degree of chromatic adaptation, which were found highly associated with the chromaticity of the adapting illuminant.

  13. Psychophysical and physiological responses to gratings with luminance and chromatic components of different spatial frequencies.

    Science.gov (United States)

    Cooper, Bonnie; Sun, Hao; Lee, Barry B

    2012-02-01

    Gratings that contain luminance and chromatic components of different spatial frequencies were used to study the segregation of signals in luminance and chromatic pathways. Psychophysical detection and discrimination thresholds to these compound gratings, with luminance and chromatic components of the one either half or double the spatial frequency of the other, were measured in human observers. Spatial frequency tuning curves for detection of compound gratings followed the envelope of those for luminance and chromatic gratings. Different grating types were discriminable at detection threshold. Fourier analysis of physiological responses of macaque retinal ganglion cells to compound waveforms showed chromatic information to be restricted to the parvocellular pathway and luminance information to the magnocellular pathway. Taken together, the human psychophysical and macaque physiological data support the strict segregation of luminance and chromatic information in independent channels, with the magnocellular and parvocellular pathways, respectively, serving as likely the physiological substrates. © 2012 Optical Society of America

  14. Photon Sieve Bandwidth Broadening by Reduction of Chromatic Aberration Effects Using Second-Stage Diffractive Optics

    Science.gov (United States)

    2015-03-26

    to copyright protection in the United States. AFIT-ENP-MS-15-M-086 PHOTON SIEVE BANDWIDTH BROADENING BY REDUCTION OF CHROMATIC ABERRATION...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-15-M-086 PHOTON SIEVE BANDWIDTH BROADENING BY REDUCTION OF CHROMATIC ABERRATION EFFECTS USING...A photon sieve is a lightweight diffractive optic which can be useful for space- based imaging applications. It is limited by chromatic

  15. Multi-Chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics

    Science.gov (United States)

    2016-05-05

    AFRL-AFOSR-VA-TR-2016-0194 Multi- Chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics Jeremy Gulley KENNESAW STATE...Jan 2016 4. TITLE AND SUBTITLE Multi- chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics 5a. CONTRACT NUMBER 5b. GRANT...in, and modification of, dielectric solids by multi- chromatic ultrashort laser pulses. It was a theoretical effort to develop models of multi

  16. Fast online simultaneous monitoring of PMD and chromatic dispersion with reduced polarization dependent gain

    Science.gov (United States)

    Ning, G.; Shum, P.; Aditya, S.; Gong, Yandong

    2006-09-01

    We use the expression relating the output state of polarization and PMD vector. Based on this expression we get the power fading including first-order PMD and chromatic dispersion, which is dependent on the angle of precession of output state of polarization around the PMD vector. From the expression for power fading, we get the average power penalty for chromatic dispersion and PMD. We propose a novel and fast PMD and chromatic dispersion monitoring technology. Measured results agree well with theoretical analysis.

  17. Nonlinear optics

    International Nuclear Information System (INIS)

    Boyd, R.W.

    1992-01-01

    Nonlinear optics is the study of the interaction of intense laser light with matter. This book is a textbook on nonlinear optics at the level of a beginning graduate student. The intent of the book is to provide an introduction to the field of nonlinear optics that stresses fundamental concepts and that enables the student to go on to perform independent research in this field. This book covers the areas of nonlinear optics, quantum optics, quantum electronics, laser physics, electrooptics, and modern optics

  18. Chromatic characterization of a three-channel colorimeter using back-propagation neural networks

    Science.gov (United States)

    Pardo, P. J.; Pérez, A. L.; Suero, M. I.

    2004-09-01

    This work describes a method for the chromatic characterization of a three-channel colorimeter of recent design and construction dedicated to color vision research. The colorimeter consists of two fixed monochromators and a third monochromator interchangeable with a cathode ray tube or any other external light source. Back-propagation neural networks were used for the chromatic characterization to establish the relationship between each monochromator's input parameters and the tristimulus values of each chromatic stimulus generated. The results showed the effectiveness of this type of neural-network-based system for the chromatic characterization of the stimuli produced by any monochromator.

  19. Chromatic aberrations correction for imaging spectrometer based on acousto-optic tunable filter with two transducers.

    Science.gov (United States)

    Zhao, Huijie; Wang, Ziye; Jia, Guorui; Zhang, Ying; Xu, Zefu

    2017-10-02

    The acousto-optic tunable filter (AOTF) with wide wavelength range and high spectral resolution has long crystal and two transducers. A longer crystal length leads to a bigger chromatic focal shift and the double-transducer arrangement induces angular mutation in diffracted beam, which increase difficulty in longitudinal and lateral chromatic aberration correction respectively. In this study, the two chromatic aberrations are analyzed quantitatively based on an AOTF optical model and a novel catadioptric dual-path configuration is proposed to correct both the chromatic aberrations. The test results exhibit effectiveness of the optical configuration for this type of AOTF-based imaging spectrometer.

  20. On the capacity to the complexing of alkaline earth metal and magnesium chromates

    International Nuclear Information System (INIS)

    Orekhov, O.L.

    1978-01-01

    Considered is the capacity to the complexing of magnesium chromates and alkaline earth metal chromates with ammonium chromates in aqueous solutions. It has been established that the complexing of alkaline earth metal and magnesium chromates is effected by a nature of initial salts as well as their solubilities and the presence of crystallization water. Capacity of magnesium ions and alkaline rare earth metals to the complexing decreases in a series of Mg-Ca-Sr-Ba. Ca complexes exceed magnesium derivatives in respect of stability

  1. Optical and chromaticity characteristics of adsorbates of the thorium complex of arsenazo I

    International Nuclear Information System (INIS)

    Ivanov, V.M.; Figurovskaya, V.N.; Ershova, N.I.

    2003-01-01

    Immobilized reagent Arsenazo I was used for the direct determination of trace thorium by diffuse reflectance spectrometry and chromaticity measurements. Silica gel Silochrom C-120 and C 18 were studied as supports. Optimal conditions of sorption were found. The dependence of chromaticity functions (chromaticity coordinates, color lightness, saturation, yellowness, and whiteness) on different chemical factors was studied. Advantages of the use of yellowness, color hue, and total color difference in comparison with other chromaticity functions was demonstrated. A method was developed for the determination of thorium with a detection limit of 0.02 μg/mL [ru

  2. On-line maintenance at Cofrentes NPP

    International Nuclear Information System (INIS)

    Roldan Vilches, J.; Moreno Matarranz, M. A.; Hermana Mendioroz, I.

    1998-01-01

    Cofrentes NPP has begun in 1997 activities related to At Power Preventive Maintenance over trains or systems which lead to a voluntary entry in a Limitative Condition of Operation (LCO) of the Technical Specifications. From others benefits, this program ha improved the risk management and the staff's knowledge over the functions and safety implications of the different systems, the better exploit of the resources, the co-ordination of the different organisations involved (Maintenance an Operation) and the reductions of works during shutdowns. Previous to each work, a feasibility study analyzes qualitative and quantitative (PSA), using the Risk Monitor, the implications on safety of all the tasks, assuring that the global safety of the Plant is always maintained. Tech. Spec. are analyzed in detail and also are analyzed situations of simultaneous unavailabilities of systems which could lead to a high risk situation. Two different risk controls are defined (punctual and accumulated) to assure that high risk situations will not be given. Finally, historical risk profile is analyzed to assure that the accumulated risk increase is not significant. Risk Monitor helps staff in the schedule and follow-up of the activities of On-Line Maintenance. Each one of the tasks are deeply planned and harshly analyzed and are carried out by high qualified workers. By the moment, this program is running with fully satisfaction on the Plant. (Author)

  3. SOL: INNOVACIÓN ON-LINE

    Directory of Open Access Journals (Sweden)

    Rubén Faúndez

    2007-11-01

    Full Text Available Las aplicaciones de simulación tienden a ser cada vez más cercanas a usuarios e industrias. Sin embargo, muchas de ellas no poseen ni la capacidad ni el conocimiento como para desarrollar internamente sus modelos de simulación. Por este motivo, y como una forma de apoyar la toma de decisiones basándose en modelos de simulación, se presenta la plataforma SOL (Simulación On Line. La metodología completa de trabajo, así como la interacción entre SOL, Empresa y Asesor, son presentadas. Su base de datos, los niveles de usuarios, sus funcionalidades, y la creación automatizada de información grafica y visual, también son explicadas. En el caso de aplicación, el uso de SOL para apoyar la toma de decisiones en una operación de movimiento de material, permite a los tomadores de decisión acceder a análisis robustos basados en información extraída de los modelos de simulación. SOL, al almacenar información, funcionar vía web, generar análisis automatizados y crear visualizaciones, permite cumplir con las expectativas de los usuarios respecto a una solución integral en simulación.

  4. Simplified automatic on-line document searching

    International Nuclear Information System (INIS)

    Ebinuma, Yukio

    1983-01-01

    The author proposed searching method for users who need not-comprehensive retrieval. That is to provide flexible number of related documents for the users automatically. A group of technical terms are used as search terms to express an inquiry. Logical sums of the terms in the ascending order of frequency of the usage are prepared sequentially and automatically, and then the search formulas, qsub(m) and qsub(m-1) which meet certain threshold values are selected automatically also. Users justify precision of the search output up to 20 items retrieved by the formula qsub(m). If a user wishes more than 30% of recall ratio, the serach result should be output by qsub(m), and if he wishes less than 30% of it, it should be output by qsub(m-1). The search by this method using one year volume of INIS Database (76,600 items) and five inquiries resulted in 32% of recall ratio and 36% of precision ratio on the average in the case of qsub(m). The connecting time of a terminal was within 15 minutes per an inquiry. It showed more efficiency than that of an inexperienced searcher. The method can be applied to on-line searching system for database in which natural language only or natural language and controlled vocabulary are used. (author)

  5. On-Line Impact Load Identification

    Directory of Open Access Journals (Sweden)

    Krzysztof Sekuła

    2013-01-01

    Full Text Available The so-called Adaptive Impact Absorption (AIA is a research area of safety engineering devoted to problems of shock absorption in various unpredictable scenarios of collisions. It makes use of smart technologies (systems equipped with sensors, controllable dissipaters and specialised tools for signal processing. Examples of engineering applications for AIA systems are protective road barriers, automotive bumpers or adaptive landing gears. One of the most challenging problems for AIA systems is on-line identification of impact loads, which is crucial for introducing the optimum real-time strategy of adaptive impact absorption. This paper presents the concept of an impactometer and develops the methodology able to perform real-time impact load identification. Considered dynamic excitation is generated by a mass M1 impacting with initial velocity V0. An analytical formulation of the problem, supported with numerical simulations and experimental verifications is presented. Two identification algorithms based on measured response of the impacted structure are proposed and discussed. Finally, a concept of the AIA device utilizing the idea of impactometer is briefly presented.

  6. Application of on-line analytical processing technique in accelerator

    International Nuclear Information System (INIS)

    Xie Dong; Li Weimin; He Duohui; Liu Gongfa; Xuan Ke

    2005-01-01

    A method of application of the on-line analytical processing technique in accelerator is described, which includes data pre-processing, the process of constructing of data warehouse and on-line analytical processing. (authors)

  7. Simultaneous Determination of Palladium and Platinum by On-line ...

    African Journals Online (AJOL)

    NJD

    using high performance liquid chromatography equipped with an on-line enrichment technique. Prior to ... The on-line enrichment system (Waters Corporation, USA) that was ... Using an appropriate volume (industrial plant effluents 20 mL,.

  8. Influence of visualization on consumption during on-line shopping

    OpenAIRE

    Hictaler, Urška

    2013-01-01

    This diploma work studies the influence of visualization on consumption during on-line shopping. The first part of the thesis starts with key areas of visualization, consumption and on-line shopping. Visualization, areas of use, human perception and ways of product presentation in on-line shops are defined discussed first. Next, consumption, consumers and factors that influence their decisions and satisfaction are defined. The last topic in the first part of the thesis discusses on-line shopp...

  9. A Distributed System for Learning Programming On-Line

    Science.gov (United States)

    Verdu, Elena; Regueras, Luisa M.; Verdu, Maria J.; Leal, Jose P.; de Castro, Juan P.; Queiros, Ricardo

    2012-01-01

    Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the "UVA On-line Judge", an existing…

  10. Nonlinear optics

    CERN Document Server

    Bloembergen, Nicolaas

    1996-01-01

    Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

  11. Individual and age-related variation in chromatic contrast adaptation

    Science.gov (United States)

    Elliott, Sarah L.; Werner, John S.; Webster, Michael A.

    2012-01-01

    Precortical color channels are tuned primarily to the LvsM (stimulation of L and M cones varied, but S cone stimulation held constant) or SvsLM (stimulation of S cones varied, but L and M cone stimulation held constant) cone-opponent (cardinal) axes, but appear elaborated in the cortex to form higher-order mechanisms tuned to both cardinal and intermediate directions. One source of evidence for these higher-order mechanisms has been the selectivity of color contrast adaptation for noncardinal directions, yet the degree of this selectivity has varied widely across the small sample of observers tested in previous studies. This study explored the possible bases for this variation, and in particular tested whether it reflected age-related changes in the distribution or tuning of color mechanisms. Observers included 15 younger (18–22 years of age) and 15 older individuals (66–82), who adapted to temporal modulations along one of four chromatic axes (two cardinal and two intermediate axes) and then matched the hue and contrast of test stimuli lying along eight different directions in the equiluminant plane. All observers exhibited aftereffects that were selective for both the cardinal and intermediate directions, although selectivity was weaker for the intermediate axes. The degree of selectivity increased with the magnitude of adaptation for all axes, and thus adaptation strength alone may account for much of the variance in selectivity among observers. Older observers showed a stronger magnitude of adaptation thus, surprisingly, more conspicuous evidence for higher-order mechanisms. For both age groups the aftereffects were well predicted by response changes in chromatic channels with linear spectral sensitivities, and there was no evidence for weakened channel tuning with aging. The results suggest that higher-order mechanisms may become more exposed in observers or conditions in which the strength of adaptation is greater, and that both chromatic contrast

  12. Chromatic Shadow Detection and Tracking for Moving Foreground Segmentation

    DEFF Research Database (Denmark)

    Huerta, Ivan; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2015-01-01

    are usually detected as part of moving objects, thus affecting the performance of the final detection. In this paper we address the detection of both penumbra and umbra shadow regions. First, a novel bottom-up approach is presented based on gradient and colour models, which successfully discriminates between...... chromatic moving cast shadow regions and those regions detected as moving objects. In essence, those regions corresponding to potential shadows are detected based on edge partitioning and colour statistics. Subsequently (i) temporal similarities between textures and (ii) spatial similarities between...

  13. Automated thermal mapping techniques using chromatic image analysis

    Science.gov (United States)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

  14. Chromatic Dispersion Compensation Using Photonic Crystal Fibers with Hexagonal Distribution

    Directory of Open Access Journals (Sweden)

    Erick E. Reyes-Vera

    2013-11-01

    Full Text Available In this paper we show various configurations of photonic crystal fiber with hexagonal holes distribution for compensation of chromatic dispersion in optical communications links. The vectorial finite element method with scattering boundary condition was used for the analysis of the fibers. From these results it was estimated variation of the dispersion and the dispersion slope with respect to change in the diameter of the holes in the microstructure. With the above was possible to obtain values of dispersion in the C and L bands of telecommunications close to -850 ps / nm * km, with confinement losses 10-3 dB / km

  15. A signal-flow-graph approach to on-line gradient calculation.

    Science.gov (United States)

    Campolucci, P; Uncini, A; Piazza, F

    2000-08-01

    A large class of nonlinear dynamic adaptive systems such as dynamic recurrent neural networks can be effectively represented by signal flow graphs (SFGs). By this method, complex systems are described as a general connection of many simple components, each of them implementing a simple one-input, one-output transformation, as in an electrical circuit. Even if graph representations are popular in the neural network community, they are often used for qualitative description rather than for rigorous representation and computational purposes. In this article, a method for both on-line and batch-backward gradient computation of a system output or cost function with respect to system parameters is derived by the SFG representation theory and its known properties. The system can be any causal, in general nonlinear and time-variant, dynamic system represented by an SFG, in particular any feedforward, time-delay, or recurrent neural network. In this work, we use discrete-time notation, but the same theory holds for the continuous-time case. The gradient is obtained in a straightforward way by the analysis of two SFGs, the original one and its adjoint (obtained from the first by simple transformations), without the complex chain rule expansions of derivatives usually employed. This method can be used for sensitivity analysis and for learning both off-line and on-line. On-line learning is particularly important since it is required by many real applications, such as digital signal processing, system identification and control, channel equalization, and predistortion.

  16. Detection and Removal of Chromatic Moving Shadows in Surveillance Scenarios

    DEFF Research Database (Denmark)

    Casado, Ivan Huerta; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2009-01-01

    . Consequently, umbra shadows are usually detected as part of moving objects. In this paper we present a novel technique based on gradient and colour models for separating chromatic moving cast shadows from detected moving objects. Firstly, both a chromatic invariant colour cone model and an invariant gradient...

  17. A "Green" Passivation of Zinc containing surfaces as an alternative to chromate

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Maahn, Ernst emanuel; Møller, Per

    1996-01-01

    comparable performance to chromate in the prohesion test. However no combination in the Molyphos system could compare with the performance of yellow chromate in the neutral salt spray test or humidity test, although Molyphos performs very well in the prohesion test. Welding tests have shown that components...... coated with sealers cause equipment problems during welding....

  18. Fluctuations in the prevalence of chromate allergy in Denmark and exposure to chrome-tanned leather

    DEFF Research Database (Denmark)

    Carøe, Caroline; Andersen, Klaus E; Thyssen, Jacob P

    2010-01-01

    A recent Danish study showed a significant increase in the prevalence of chromate contact allergy after the mid-1990s, probably as a result of exposure to leather products.......A recent Danish study showed a significant increase in the prevalence of chromate contact allergy after the mid-1990s, probably as a result of exposure to leather products....

  19. Uncertainty of chromatic dispersion estimation from transmitted waveforms in direct detection systems

    Science.gov (United States)

    Lach, Zbigniew T.

    2017-08-01

    A possibility is shown of a non-disruptive estimation of chromatic dispersion in a fiber of an intensity modulation communication line under work conditions. Uncertainty of the chromatic dispersion estimates is analyzed and quantified with the use of confidence intervals.

  20. Efficient removal of chromate and arsenate from individual and mixed system by malachite nanoparticles

    International Nuclear Information System (INIS)

    Saikia, Jiban; Saha, Bedabrata; Das, Gopal

    2011-01-01

    Graphical abstract: Malachite nanoparticles of 100-150 nm, have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate in pH range 4-5. - Abstract: Malachite nanoparticles of 100-150 nm have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate. We report a high adsorption capacity for chromate and arsenate on malachite nanoparticle from both individual and mixed solution in pH ∼4-5. However, the adsorption efficiency decreases with the increase of solution pH. Batch studies revealed that initial pH, temperature, malachite nanoparticles dose and initial concentration of chromate and arsenate were important parameters for the adsorption process. Thermodynamic analysis showed that adsorption of chromate and arsenate on malachite nanoparticles is endothermic and spontaneous. The adsorption of these anions has also been investigated quantitatively with the help of adsorption kinetics, isotherm, and selectivity coefficient (K) analysis. The adsorption data for both chromate and arsenate were fitted well in Langmuir isotherm and preferentially followed the second order kinetics. The binding affinity of chromate is found to be slightly higher than arsenate in a competitive adsorption process which leads to the comparatively higher adsorption of chromate on malachite nanoparticles surface.

  1. Chromatic dispersion of liquid crystal infiltrated capillary tubes and photonic crystal fibers

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Lægsgaard, Jesper; Bang, Ole

    2006-01-01

    We consider chromatic dispersion of capillary tubes and photonic crystal fibers infiltrated with liquid crystals. A perturbative scheme for inclusion of material dispersion of both liquid crystal and the surrounding waveguide material is derived. The method is used to calculate the chromatic...

  2. Delays in using chromatic and luminance information to correct rapid reaches.

    Science.gov (United States)

    Kane, Adam; Wade, Alex; Ma-Wyatt, Anna

    2011-09-07

    People can use feedback to make online corrections to movements but only if there is sufficient time to integrate the new information and make the correction. A key variable in this process is therefore the speed at which the new information about the target location is coded. Conduction velocities for chromatic signals are lower than for achromatic signals so it may take longer to correct reaches to chromatic stimuli. In addition to this delay, the sensorimotor system may prefer achromatic information over the chromatic information as delayed information may be less valuable when movements are made under time pressure. A down-weighting of chromatic information may result in additional latencies for chromatically directed reaches. In our study, participants made online corrections to reaches to achromatic, (L-M)-cone, and S-cone stimuli. Our chromatic stimuli were carefully adjusted to minimize stimulation of achromatic pathways, and we equated stimuli both in terms of detection thresholds and also by their estimated neural responses. Similar stimuli were used throughout the subjective adjustments and final reaching experiment. Using this paradigm, we found that responses to achromatic stimuli were only slightly faster than responses to (L-M)-cone and S-cone stimuli. We conclude that the sensorimotor system treats chromatic and achromatic information similarly and that the delayed chromatic responses primarily reflect early conduction delays.

  3. Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.

    Science.gov (United States)

    Gutmann, Michael U; Laparra, Valero; Hyvärinen, Aapo; Malo, Jesús

    2014-01-01

    Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified) statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.

  4. Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    In this study, oxide layers generated on aluminum alloy 6060(UNS A96060) using a steam-based process were compared with conventional chromate and chromate-phosphate conversion coatings. Chemical composition and microstructure of the conversion coatings were investigated and their corrosion perfor...

  5. Cloning and sequence analysis demonstrate the chromate reduction ability of a novel chromate reductase gene from Serratia sp.

    Science.gov (United States)

    Deng, Peng; Tan, Xiaoqing; Wu, Ying; Bai, Qunhua; Jia, Yan; Xiao, Hong

    2015-03-01

    The ChrT gene encodes a chromate reductase enzyme which catalyzes the reduction of Cr(VI). The chromate reductase is also known as flavin mononucleotide (FMN) reductase (FMN_red). The aim of the present study was to clone the full-length ChrT DNA from Serratia sp. CQMUS2 and analyze the deduced amino acid sequence and three-dimensional structure. The putative ChrT gene fragment of Serratia sp. CQMUS2 was isolated by polymerase chain reaction (PCR), according to the known FMN_red gene sequence from Serratia sp. AS13. The flanking sequences of the ChrT gene were obtained by high efficiency TAIL-PCR, while the full-length gene of ChrT was cloned in Escherichia coli for subsequent sequencing. The nucleotide sequence of ChrT was submitted onto GenBank under the accession number, KF211434. Sequence analysis of the gene and amino acids was conducted using the Basic Local Alignment Search Tool, and open reading frame (ORF) analysis was performed using ORF Finder software. The ChrT gene was found to be an ORF of 567 bp that encodes a 188-amino acid enzyme with a calculated molecular weight of 20.4 kDa. In addition, the ChrT protein was hypothesized to be an NADPH-dependent FMN_red and a member of the flavodoxin-2 superfamily. The amino acid sequence of ChrT showed high sequence similarity to the FMN reductase genes of Klebsiella pneumonia and Raoultella ornithinolytica , which belong to the flavodoxin-2 superfamily. Furthermore, ChrT was shown to have a 85.6% similarity to the three-dimensional structure of Escherichia coli ChrR, sharing four common enzyme active sites for chromate reduction. Therefore, ChrT gene cloning and protein structure determination demonstrated the ability of the gene for chromate reduction. The results of the present study provide a basis for further studies on ChrT gene expression and protein function.

  6. Cloning and sequence analysis demonstrate the chromate reduction ability of a novel chromate reductase gene from Serratia sp

    Science.gov (United States)

    DENG, PENG; TAN, XIAOQING; WU, YING; BAI, QUNHUA; JIA, YAN; XIAO, HONG

    2015-01-01

    The ChrT gene encodes a chromate reductase enzyme which catalyzes the reduction of Cr(VI). The chromate reductase is also known as flavin mononucleotide (FMN) reductase (FMN_red). The aim of the present study was to clone the full-length ChrT DNA from Serratia sp. CQMUS2 and analyze the deduced amino acid sequence and three-dimensional structure. The putative ChrT gene fragment of Serratia sp. CQMUS2 was isolated by polymerase chain reaction (PCR), according to the known FMN_red gene sequence from Serratia sp. AS13. The flanking sequences of the ChrT gene were obtained by high efficiency TAIL-PCR, while the full-length gene of ChrT was cloned in Escherichia coli for subsequent sequencing. The nucleotide sequence of ChrT was submitted onto GenBank under the accession number, KF211434. Sequence analysis of the gene and amino acids was conducted using the Basic Local Alignment Search Tool, and open reading frame (ORF) analysis was performed using ORF Finder software. The ChrT gene was found to be an ORF of 567 bp that encodes a 188-amino acid enzyme with a calculated molecular weight of 20.4 kDa. In addition, the ChrT protein was hypothesized to be an NADPH-dependent FMN_red and a member of the flavodoxin-2 superfamily. The amino acid sequence of ChrT showed high sequence similarity to the FMN reductase genes of Klebsiella pneumonia and Raoultella ornithinolytica, which belong to the flavodoxin-2 superfamily. Furthermore, ChrT was shown to have a 85.6% similarity to the three-dimensional structure of Escherichia coli ChrR, sharing four common enzyme active sites for chromate reduction. Therefore, ChrT gene cloning and protein structure determination demonstrated the ability of the gene for chromate reduction. The results of the present study provide a basis for further studies on ChrT gene expression and protein function. PMID:25667630

  7. Robust on-line monitoring of biogas processes; Robusta maettekniker on-line foer optimerad biogasproduktion

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Aake; Hansson, Mikael; Kanerot, Mija; Krozer, Anatol; Loefving, Bjoern; Sahlin, Eskil

    2010-03-15

    Although demand for biomethane in Sweden is higher than ever, many Swedish codigestion plants are presently operated below their designed capacity. Efforts must be taken to increase the loading rate and guarantee stable operation and high availability of the plants. There are currently no commercial systems for on-line monitoring, and due to the characteristics of the material, including corrosion and tearing, robust applications have to be developed. The objective of this project was to identify and study different monitoring technologies with potential for on-line monitoring of both substrate mixtures and anaerobic digester content. Based on the prerequisites and demands at Boraas Energi och Miljoe AB's (BEMAB, the municipal energy and waste utility in the city of Boraas, Sweden) biogas plant, the extent of the problems, measurement variables and possible ways of managing these issues have been identified and prioritized. The substrate mixtures in question have a high viscosity and are inhomogeneous with variation in composition, which calls for further homogenization, dilution and filtration to achieve high precision in the necessary analyses. Studies of using different mixers and mills showed that the particle size (800 mum) needed for on-line COD measurement could not be achieved. The problem of homogenization can be avoided if indirect measurement methods are used. Laboratory tests with NIR (near-infra red spectroscopy) showed that VS can be predicted (R2=0,78) in the interval of 2-9% VS. Furthermore, impedance can give a measurement of soluble components. However, impedance is not sensitive enough to give a good measurement of total TS. Microwave technology was installed at the production plant and showed a faster response to changes in TS than the existing TS-sensor. However, due to technical problems, the evaluation only could be done during a limited period of ten days. BEMAB will continue the measurements and evaluation of the instrument. The

  8. Chromatic discrimination: differential contributions from two adapting fields

    Science.gov (United States)

    Cao, Dingcai; Lu, Yolanda H.

    2012-01-01

    To test whether a retinal or cortical mechanism sums contributions from two adapting fields to chromatic discrimination, L/M discrimination was measured with a test annulus surrounded by an inner circular field and an outer rectangular field. A retinal summation mechanism predicted that the discrimination pattern would not change with a change in the fixation location. Therefore, the fixation was set either in the inner or the outer field in two experiments. When one of the adapting fields was “red” and the other was “green,” the adapting field where the observer fixated always had a stronger influence on chromatic discrimination. However, when one adapting field was “white” and the other was red or green, the white field always weighted more heavily than the other adapting field in determining discrimination thresholds, whether the white field or the fixation was in the inner or outer adapting field. These results suggest that a cortical mechanism determines the relative contributions from different adapting fields. PMID:22330364

  9. Chromatic aberration, accommodation, and color preference in asthenopia.

    Science.gov (United States)

    Drew, Stefanie A; Borsting, Eric; Stark, Lawrence R; Chase, Chris

    2012-07-01

    Asthenopia is a common problem associated with near work and reports suggest that colored lenses or overlays may be applied to reduce symptoms. In this study, we examine the relationship between eyestrain, color preferences, and function of the accommodation and vergence system. Specifically, we examine whether symptomatic observers select colors that reduce accommodative demand based on longitudinal chromatic aberration (LCA). Forty-seven undergraduate students participated in this study. Visual discomfort symptoms were assessed using the Conlon survey. A Mark 2 Intuitive Colorimeter was used to obtain optimal colored light preferences. LCA was modeled using the Chromatic Eye and spectral power density data. A comprehensive evaluation of accommodation and vergence was performed following standard procedures. A significant negative correlation (r = -0.51) was found between eyestrain symptoms and the International Commission on Illumination (CIE) v' axis of colors preferences. Additionally, a significant negative correlation (r = -0.31) was found between eyestrain symptoms and LCA accommodation. Two thirds of the participants in the high discomfort group chose colors that decreased accommodative demand. Accommodative amplitude and vergence facility also correlated with LCA, accounting for 25% of the variance. The color preferences of individuals are systematically influenced by the functioning of their accommodation and vergence systems with increased symptomatology resulting in color selections that reduce LCA accommodative stimulus demand.

  10. Monitoring of Optical Emission from High Temperature Plasma Based on Chromatic Modulation

    International Nuclear Information System (INIS)

    Dimitrios, Tomtsis

    2009-01-01

    An integrated experimental approach is presented for processing the optical emission produced from electric arc plasma. The method is based on chromatic modulation techniques to provide a holistic measurement of the persistence of particle decays within the environment of high power circuit breakers. Chromaticity changes in a number of chromatic parameters are related to changes in physical electric arc plasma environment (e.g. particle concentration). The results are in the form of chromatic maps which show how the overall electric arc plasma and its environment behave and respond. Such maps show the totality of information which can be accessed about the arcing event and the level of monitoring discrimination which is achievable with the chromatic methodology in a simple and easy to understand manner. The suggested method provides easier data analysis and high levels of data compression.

  11. Construction of special eye models for investigation of chromatic and higher-order aberrations of eyes.

    Science.gov (United States)

    Zhai, Yi; Wang, Yan; Wang, Zhaoqi; Liu, Yongji; Zhang, Lin; He, Yuanqing; Chang, Shengjiang

    2014-01-01

    An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists.

  12. Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance.

    Science.gov (United States)

    Cooper, Bonnie; Lee, Barry B

    2014-04-01

    Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment of luminance and chromatic gratings matched or mismatched in contrast polarity or grating type. Thresholds with matched gratings were low while all mismatched pairs were elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of constant contrast components of the other type. For in-phase components, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions, which suggested that luminance can override chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.

  13. Chromatic-achromatic perimetry in four clinic cases: Glaucoma and diabetes.

    Science.gov (United States)

    Cabezos, Inmaculada; Luque, Maria Jos; de Fez, Dolores; Moncho, Vicenta; Camps, Vicente

    2015-02-01

    Some diseases that affect the visual system may show loss of chromatic-achromatic sensitivity before obvious physical signs appear in the usual examination of the eye's posterior segment. A perimetric study has been conducted with four typical patients with glaucoma and diabetes, at different stages of the disease. In addition to the standard white-on-white (standard automated perimetry [SAP]), a test battery has been used to study patient's contrast sensitivity, using stimuli with different chromatic, spatial, and temporal content (multichannel perimetry). The choice of stimuli tries to maximize the response of different visual mechanisms: Achromatic (parvocellular and magnocellular origin); chromatic red-green (parvocellular origin); and chromatic blue-yellow (koniocellular origin). The results seem to indicate losses in the achromatic-parvocellular perimetry and both chromatic perimetry tests, undetected by conventional SAP. Our results illustrate that our patients without visible retinal alterations show signs of suspicion in multichannel perimetry.

  14. Nonlinear Science

    CERN Document Server

    Yoshida, Zensho

    2010-01-01

    This book gives a general, basic understanding of the mathematical structure "nonlinearity" that lies in the depths of complex systems. Analyzing the heterogeneity that the prefix "non" represents with respect to notions such as the linear space, integrability and scale hierarchy, "nonlinear science" is explained as a challenge of deconstruction of the modern sciences. This book is not a technical guide to teach mathematical tools of nonlinear analysis, nor a zoology of so-called nonlinear phenomena. By critically analyzing the structure of linear theories, and cl

  15. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  16. Color-motion feature-binding errors are mediated by a higher-order chromatic representation.

    Science.gov (United States)

    Shevell, Steven K; Wang, Wei

    2016-03-01

    Peripheral and central moving objects of the same color may be perceived to move in the same direction even though peripheral objects have a different true direction of motion [Nature429, 262 (2004)10.1038/429262a]. The perceived, illusory direction of peripheral motion is a color-motion feature-binding error. Recent work shows that such binding errors occur even without an exact color match between central and peripheral objects, and, moreover, the frequency of the binding errors in the periphery declines as the chromatic difference increases between the central and peripheral objects [J. Opt. Soc. Am. A31, A60 (2014)JOAOD60740-323210.1364/JOSAA.31.000A60]. This change in the frequency of binding errors with the chromatic difference raises the general question of the chromatic representation from which the difference is determined. Here, basic properties of the chromatic representation are tested to discover whether it depends on independent chromatic differences on the l and the s cardinal axes or, alternatively, on a more specific higher-order chromatic representation. Experimental tests compared the rate of feature-binding errors when the central and peripheral colors had the identical s chromaticity (so zero difference in s) and a fixed magnitude of l difference, while varying the identical s level in center and periphery (thus always keeping the s difference at zero). A chromatic representation based on independent l and s differences would result in the same frequency of color-motion binding errors at everyslevel. The results are contrary to this prediction, thus showing that the chromatic representation at the level of color-motion feature binding depends on a higher-order chromatic mechanism.

  17. On-line estimator/detector design for a plutonium nitrate concentrator unit

    International Nuclear Information System (INIS)

    Candy, J.V.; Rozsa, R.B.

    1979-04-01

    In this report we consider the design of a nonlinear estimator to be used in conjunction with on-line detectors for a plutonium/concentrator. Using a complex state-of-the-art process model to simulate realistic data, we show that the estimator performance using a simplified process model is adequate over a wide range of operation. The estimator is used to simulate and characterize some on-line diversion detectors, i.e., detectors designed to indicate if some of the critical special nuclear material in process is stolen or diverted from the unit. Several different diversion scenarios are presented. Simulation results indicate that the estimators and detectors yielded reasonable performance for the scenarios investigated

  18. On-Line Tracking Controller for Brushless DC Motor Drives Using Artificial Neural Networks

    Science.gov (United States)

    Rubaai, Ahmed

    1996-01-01

    A real-time control architecture is developed for time-varying nonlinear brushless dc motors operating in a high performance drives environment. The developed control architecture possesses the capabilities of simultaneous on-line identification and control. The dynamics of the motor are modeled on-line and controlled using an artificial neural network, as the system runs. The control architecture combines the experience and dependability of adaptive tracking systems with potential and promise of the neural computing technology. The sensitivity of real-time controller to parametric changes that occur during training is investigated. Such changes are usually manifested by rapid changes in the load of the brushless motor drives. This sudden change in the external load is simulated for the sigmoidal and sinusoidal reference tracks. The ability of the neuro-controller to maintain reasonable tracking accuracy in the presence of external noise is also verified for a number of desired reference trajectories.

  19. DOE-EPRI On-Line Monitoring Implementation Guidelines

    International Nuclear Information System (INIS)

    E. Davis, R. Bickford

    2003-01-01

    Industry and EPRI experience at several plants has shown on-line monitoring to be very effective in identifying out-of-calibration instrument channels or indications of equipment-degradation problems. The EPRI implementation project for on-line monitoring has demonstrated the feasibility of on-line monitoring at several participating nuclear plants. The results have been very encouraging, and substantial progress is anticipated in the coming years

  20. Nonlinear systems

    CERN Document Server

    Palmero, Faustino; Lemos, M; Sánchez-Rey, Bernardo; Casado-Pascual, Jesús

    2018-01-01

    This book presents an overview of the most recent advances in nonlinear science. It provides a unified view of nonlinear properties in many different systems and highlights many  new developments. While volume 1 concentrates on mathematical theory and computational techniques and challenges, which are essential for the study of nonlinear science, this second volume deals with nonlinear excitations in several fields. These excitations can be localized and transport energy and matter in the form of breathers, solitons, kinks or quodons with very different characteristics, which are discussed in the book. They can also transport electric charge, in which case they are known as polarobreathers or solectrons. Nonlinear excitations can influence function and structure in biology, as for example, protein folding. In crystals and other condensed matter, they can modify transport properties, reaction kinetics and interact with defects. There are also engineering applications in electric lattices, Josephson junction a...

  1. Chromatic Modulator for a High-Resolution CCD or APS

    Science.gov (United States)

    Hartley, Frank; Hull, Anthony

    2008-01-01

    A chromatic modulator has been proposed to enable the separate detection of the red, green, and blue (RGB) color components of the same scene by a single charge-coupled device (CCD), active-pixel sensor (APS), or similar electronic image detector. Traditionally, the RGB color-separation problem in an electronic camera has been solved by use of either (1) fixed color filters over three separate image detectors; (2) a filter wheel that repeatedly imposes a red, then a green, then a blue filter over a single image detector; or (3) different fixed color filters over adjacent pixels. The use of separate image detectors necessitates precise registration of the detectors and the use of complicated optics; filter wheels are expensive and add considerably to the bulk of the camera; and fixed pixelated color filters reduce spatial resolution and introduce color-aliasing effects. The proposed chromatic modulator would not exhibit any of these shortcomings. The proposed chromatic modulator would be an electromechanical device fabricated by micromachining. It would include a filter having a spatially periodic pattern of RGB strips at a pitch equal to that of the pixels of the image detector. The filter would be placed in front of the image detector, supported at its periphery by a spring suspension and electrostatic comb drive. The spring suspension would bias the filter toward a middle position in which each filter strip would be registered with a row of pixels of the image detector. Hard stops would limit the excursion of the spring suspension to precisely one pixel row above and one pixel row below the middle position. In operation, the electrostatic comb drive would be actuated to repeatedly snap the filter to the upper extreme, middle, and lower extreme positions. This action would repeatedly place a succession of the differently colored filter strips in front of each pixel of the image detector. To simplify the processing, it would be desirable to encode information on

  2. On-line control of a liquid-liquid extraction column by the modal control method

    International Nuclear Information System (INIS)

    Bonnefoi, P.; Poujol, A.; Zwingelstein, G.; Dargier, C.; Rouyer, H.

    1977-02-01

    The application of modal analysis to the on-line control of a liquid-liquid extraction column is presented. This process is used in reprocessing for U purification. U in the aqueous acid phase is extracted by a solvent flowing at counter-current. The process is described by 4 nonlinear equations and gives the U and acid concentrations in the two phases. An approximative model is established adapted to the control of the column. Some results of a numerical simulation are given when a single mode is controled. They show that a single sensor allows a good control [fr

  3. Measurement and correction of transverse chromatic offsets for multi-wavelength retinal microscopy in the living eye.

    Science.gov (United States)

    Harmening, Wolf M; Tiruveedhula, Pavan; Roorda, Austin; Sincich, Lawrence C

    2012-09-01

    A special challenge arises when pursuing multi-wavelength imaging of retinal tissue in vivo, because the eye's optics must be used as the main focusing elements, and they introduce significant chromatic dispersion. Here we present an image-based method to measure and correct for the eye's transverse chromatic aberrations rapidly, non-invasively, and with high precision. We validate the technique against hyperacute psychophysical performance and the standard chromatic human eye model. In vivo correction of chromatic dispersion will enable confocal multi-wavelength images of the living retina to be aligned, and allow targeted chromatic stimulation of the photoreceptor mosaic to be performed accurately with sub-cellular resolution.

  4. Efficient removal of chromate and arsenate from individual and mixed system by malachite nanoparticles.

    Science.gov (United States)

    Saikia, Jiban; Saha, Bedabrata; Das, Gopal

    2011-02-15

    Malachite nanoparticles of 100-150 nm have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate. We report a high adsorption capacity for chromate and arsenate on malachite nanoparticle from both individual and mixed solution in pH ∼4-5. However, the adsorption efficiency decreases with the increase of solution pH. Batch studies revealed that initial pH, temperature, malachite nanoparticles dose and initial concentration of chromate and arsenate were important parameters for the adsorption process. Thermodynamic analysis showed that adsorption of chromate and arsenate on malachite nanoparticles is endothermic and spontaneous. The adsorption of these anions has also been investigated quantitatively with the help of adsorption kinetics, isotherm, and selectivity coefficient (K) analysis. The adsorption data for both chromate and arsenate were fitted well in Langmuir isotherm and preferentially followed the second order kinetics. The binding affinity of chromate is found to be slightly higher than arsenate in a competitive adsorption process which leads to the comparatively higher adsorption of chromate on malachite nanoparticles surface. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Luminance and chromatic contributions to a hyperacuity task: isolation by contrast polarity and target separation.

    Science.gov (United States)

    Sun, Hao; Cooper, Bonnie; Lee, Barry B

    2012-03-01

    Vernier thresholds are known to be elevated when a target pair has opposite contrast polarity. Polarity reversal is used to assess the role of luminance and chromatic pathways in hyperacuity performance. Psychophysical hyperacuity thresholds were measured for pairs of gratings of various combinations of luminance (Lum) and chromatic (Chr) contrast polarities, at different ratios of luminance to chromatic contrast. With two red-green gratings of matched luminance and chromatic polarity (+Lum+Chr), there was an elevation of threshold at isoluminance. When both luminance and chromatic polarity were mismatched (-Lum-Chr), thresholds were substantially elevated under all conditions. With the same luminance contrast polarity and opposite chromatic polarity (+Lum-Chr) thresholds were only elevated close to isoluminance; in the reverse condition (-Lum+Chr), thresholds were elevated as in the -Lum-Chr condition except close to equiluminance. Similar data were obtained for gratings isolating the short-wavelength cone mechanism. Further psychophysical measurements assessed the role of target separation with matched or mismatched contrast polarity; similar results were found for luminance and chromatic gratings. Comparison physiological data were collected from parafoveal ganglion cells of the macaque retina. Positional precision of ganglion cell signals was assessed under conditions related to the psychophysical measurements. On the basis of these combined observations, it is argued that both magnocellular, parvocellular, and koniocellular pathways have access to cortical positional mechanisms associated with vernier acuity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Pupillometer-based objective chromatic perimetry in normal eyes and patients with retinal photoreceptor dystrophies.

    Science.gov (United States)

    Skaat, Alon; Sher, Ifat; Kolker, Andrew; Elyasiv, Sivan; Rosenfeld, Elkana; Mhajna, Mohamad; Melamed, Shlomo; Belkin, Michael; Rotenstreich, Ygal

    2013-04-17

    To evaluate a novel objective perimetry using multifocal chromatic pupil light reflex in normal participants and patients with photoreceptor dysfunction, and to relate this new technique with subjective dark-adapted chromatic Goldmann perimetry. Thirty-two eyes of 17 retinitis pigmentosa (RP) or cone-rod dystrophy patients and 20 eyes of 12 healthy individuals were tested. A computerized infrared video pupillometer was used to record changes in pupil diameter in response to short- and long-wavelength stimuli (peak 485 and 640 nm, respectively; light intensity 40 cd/m(2)) at 13 different points of the 30° visual field (VF), under background illumination of 2.7 cd/m(2). The pupillary response (PR) of patients was compared with PR obtained from normal control participants. In 11 patients, the pupillary responses were also compared with their findings on dark-adapted chromatic Goldmann perimetry. Significantly reduced pupillary responses were obtained in RP patients in response to the short-wavelength stimulus in nearly all perimetric locations (P chromatic Goldmann perimetry. In all patients that were tested by the chromatic Goldmann, minimal PR was recorded in areas that were nondetected in the chromatic Goldmann perimetry. This study demonstrates the potential feasibility of using pupillometer-based chromatic perimetry for objectively assessing VF defects and retinal function in patients with retinal dystrophies. (ClinicalTrials.gov number, NCT01021982.).

  7. Toward the identification of DSLR lenses by chromatic aberration

    Science.gov (United States)

    Yu, Jun; Craver, Scott; Li, Enping

    2011-02-01

    While previous work on lens identification by chromatic aberration succeeded in distinguishing lenses of different model, the CA patterns obtained were not stable enough to support distinguishing different copies of the same lens. This paper discusses on how to eliminate two major hurdles in the way of obtaining a stable lens CA pattern. The first hurdle was overcome by using a white noise pattern as shooting target to supplant the conventional but misalignment-prone checkerboard pattern. The second hurdle was removed by the introduction of the lens focal distance, which had not received the attention it deserves. Consequently, we were able to obtain a stable enough CA pattern distinguishing different copies of the same lens. Finally, with a complete view of the lens CA pattern feature space, it is possible to fulfil lens identification among a large lens database.

  8. Some relations between rank, chromatic number and energy of graphs

    International Nuclear Information System (INIS)

    Akbari, S.; Ghorbani, E.; Zare, S.

    2006-08-01

    The energy of a graph G is defined as the sum of the absolute values of all eigenvalues of G and denoted by E(G). Let G be a graph and rank(G) be the rank of the adjacency matrix of G. In this paper we characterize all the graphs with E(G) = rank(G). Among other results we show that apart from a few families of graphs, E(G) ≥ 2max(χ(G), n - χ(G--bar)), where G-bar and χ(G) are the complement and the chromatic number of G, respectively. Moreover some new lower bounds for E(G) in terms of rank(G) are given. (author)

  9. Correction of chromatic and geometric aberrations using sextupoles and octupoles

    International Nuclear Information System (INIS)

    Colton, E.

    1978-01-01

    The procedure for applying some chromatic corrections to a final transport line, neglecting space charge, utilizing the method suggested by Brown is described. The possibility of including octupoles into a point-to-point triplet system, as outlined by Fenster is studied. Positive results were obtained in both cases: (i) using 2 + I correcting sections with two pairs of non-interlaced sextupoles increased the fraction of beam with ΔP/P = 1% onto a 0.1 cm radius target by more than a factor of 1.75; (ii) six octupoles placed into a point-to-point triplet system increased the fraction of a full emittance ΔP/P = 0% beam striking a 0.1 cm radius target by a factor of 2.5

  10. Chromatic perturbation and resonance analysis for the AGS-Booster

    International Nuclear Information System (INIS)

    Parsa, Z.

    1987-01-01

    The authors investigated the nonlinear effects with the emphasis on nonlinear resonances. They present some of their findings, (e.g. the structure resonances; stop-bandwidths, etc.) for the AGS-Booster Lattice using program HARMON. Comparison with the results obtained from the algorithm ''NONLIN'' is presented

  11. Sorption mechanisms of chromate with coprecipitated ferrihydrite in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Mamun, Abdullah Al, E-mail: mamun@toki.waseda.jp [Graduate School of Creative Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Morita, Masao, E-mail: masao.swimer@akane.waseda.jp [Graduate School of Creative Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Matsuoka, Mitsuaki, E-mail: m-matsuoka@aoni.waseda.jp [Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Tokoro, Chiharu, E-mail: tokoro@waseda.jp [Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2017-07-15

    Highlights: • Coprecipitation showed twice the sorption density of simple adsorption at pH 5. • Mechanism shift from outer- to inner-sphere surface complexation at high Cr/Fe. • In coprecipitation the mechanism shift occurs at lower Cr/Fe ratios than adsorption. • Higher-molar-ratio bidentate binuclear Cr−Fe bonds; yielded ferrihydrite expansion. - Abstract: Hexavalent chromium (Cr(VI)) attracted researchers’ interest for its toxicity, natural availability and removal difficulty. Nevertheless, its sorption mechanism is not clearly understood yet. In this work, we elucidated the sorption mechanism of the co-precipitation of chromates with ferrihydrite through quantitative analysis. The influence of Cr/Fe molar ratio on sorption was investigated by zeta potential measurements, X-ray diffraction (XRD) and X-ray adsorption fine-structure analysis (XAFS). Coprecipitation at pH 5 showed almost twice the sorption density of adsorption at pH 5. In co-precipitation, a shift of the XRD peak due to inner-sphere sorption of chromate was observed at Cr/Fe molar ratio 0.5. For adsorption, the same peak shift was confirmed at Cr/Fe molar ratio of 1. Zeta potential at pH 5 suggested that the sorption mechanism changed at Cr/Fe molar ratio 0.25 for coprecipitation and at Cr/Fe molar ratio of 1 for adsorption. Fitting of Cr and Fe K-edge extended X-ray adsorption fine-structure suggested that ferrihydrite immobilized Cr(VI) via outer sphere surface complexation for lower Cr/Fe ratios and via inner-sphere surface complexation for higher molar ratios. At higher molar ratios, bidentate binuclear Cr−Fe bonds were well established, thus resulting in the expansion of the ferrihydrite structure.

  12. Pupillary response to direct and consensual chromatic light stimuli.

    Science.gov (United States)

    Traustason, Sindri; Brondsted, Adam Elias; Sander, Birgit; Lund-Andersen, Henrik

    2016-02-01

    To assess whether the direct and consensual postillumination (ipRGC-driven) pupil light responses to chromatic light stimuli are equal in healthy subjects. Pupil responses in healthy volunteers were recorded using a prototype binocular chromatic pupillometer (IdeaMedical, Copenhagen), which is capable of both direct and consensual pupillometry measurements. The device uses a pair of dual monochromatic narrow bandwidth LED light sources, red (660 nm) and blue (470 nm). Pupil light responses were recorded with infrared video cameras and analysed using custom-made circuitry and software. Subjects were randomized to receive light stimuli at either the right or left eye after 5 min of dark adaptation. Pupil light responses were recorded in both eyes for 10 seconds before illumination, during illumination and 50 seconds after illumination with red and blue light. Three variables were defined for the recorded pupil responses: the maximal constriction amplitude (CAmax ), the pupil response during illumination and postillumination pupil response (PIPR). No difference was found in the pupil response to blue light. With red light, the pupil response during illumination was slightly larger during consensual illumination compared to direct illumination (0.54 and 0.52, respectively, p = 0.027, paired Wilcoxon's test, n = 12), while no differences were found for CAmax or the PIPR. No difference was found between direct and consensual pupil response to either red or blue light in the postillumination period. Direct and consensual responses can readily be compared when examining the postillumination pupil response to blue light as estimation of photosensitive retinal ganglion cell activation. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  13. Chromate reduction and heavy metal fixation in soil

    International Nuclear Information System (INIS)

    Schwitzgebel, K.

    1992-06-01

    In situ reduction of chromates and the fixation of the metals Cr, Pb, Zn, Cu, Cd and Ni in soil was investigated using Fe II and soluble silica. Fe II fulfills two functions. It reduces chromates (CrVI) at soil pH to CrIII and the reaction products, Fe(OH) 3 and Cr(OH) 3 , coprecipitate/adsorb heavy metals. In the absence of CrVI iron is added as FeIII. Destabilized silica also fulfills two functions. It reacts with the metal and metal hydroxides and reduces the soil permeability. The leaching rate (mg/m 2 s) of a metal is the product of leachate flow rate (ell/M 2 s) and the leachate concentration (mg/ell). The leachate flow rate is directly proportional to the hydraulic coefficient (Darcy's Law). Treatment with destabilized silica reduces the hydraulic coefficient of virgin soil (K h = 10 -2 ...10 -4 ) to K h =10 -7 (cm/s) resulting in a flow rate reduction of 3--5 orders of magnitude. Iron plus silica treatment results in a leachate concentration reduction of up to 2 orders of magnitude (Cr:95--99%;Pb:99%;Zn 95--99%; Cd:93--99%; Ni:75--94%). Combined effect of flow rate reduction and leachate concentration reduction results in a potential leaching rate reduction of five to seven orders of magnitude. Iron-silica treatment may be developed into an efficient containment technology, provided the silica gel integrity does not change with time

  14. On-line dynamic extraction and automated determination of readily bioavailable hexavalent chromium in solid substrates using micro-sequential injection bead-injection lab-on-valve hyphenated with electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2006-01-01

    A novel and miniaturized micro-sequential injection bead injection lab-on-valve (μSI-BI-LOV) fractionation system was developed for in-line microcolumn soil extraction under simulated environmental scenarios and accurate monitoring of the content of easily mobilisable hexavalent chromium in soil...... environments at the sub-low parts-per-million level. The flow system integrates dynamic leaching of hexavalent chromium using deionized water as recommended by the German Standard DIN 38414-S4 method; on-line pH adjustment of the extract by a 0.01 mol L-1 Tris-HNO3 buffer solution; isolation of the chromate...... polluted agricultural soil material (San Joaquin Soil-Baseline Trace Element Concentrations) with water-soluble Cr(VI) salts at different concentration levels. The potential of the μSI-BI-LOV set-up with renewable surfaces for flame-AAS determination of high levels of readily bioavailable chromate...

  15. The structure of chromatic polynomials of planar triangulations and implications for chromatic zeros and asymptotic limiting quantities

    International Nuclear Information System (INIS)

    Shrock, Robert; Xu Yan

    2012-01-01

    We present an analysis of the structure and properties of chromatic polynomials P(G pt,m-vector, q) of one-parameter and multi-parameter families of planar triangulation graphs G pt,m-vector , where m-vector = (m 1 ,…,m p ) is a vector of integer parameters. We use these to study the ratio of |P(G pt,m-vector, τ+1)| to the Tutte upper bound (τ − 1) n−5 , where τ=(1+√5)/2 and n is the number of vertices in G pt,m-vector . In particular, we calculate limiting values of this ratio as n → ∞ for various families of planar triangulations. We also use our calculations to analyze zeros of these chromatic polynomials. We study a large class of families G pt,m-vector with p = 1 and p = 2 and show that these have a structure of the form P(G pt,m ,q) = c G pt ,1 λ 1 m + c G pt ,2 λ 2 m + c G pt ,3 λ 3 m for p = 1, where λ 1 = q − 2, λ 2 = q − 3, and λ 3 = −1, and P(G pt,m-vector ,q) =Σ i 1 =1 3 Σ i 2 =1 3 c G pt ,i 1 i 2 λ i 1 m 1 λ i 2 m 2 for p = 2. We derive properties of the coefficients c G pt ,i-vector and show that P(G pt,m-vector ,q) has a real chromatic zero that approaches (1/2)(3+√5) as one or more of the m i → ∞. The generalization to p ⩾ 3 is given. Further, we present a one-parameter family of planar triangulations with real zeros that approach 3 from below as m → ∞. Implications for the ground-state entropy of the Potts antiferromagnet are discussed. (paper)

  16. Nonlinear optics

    CERN Document Server

    Boyd, Robert W

    2013-01-01

    Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

  17. Algorithms for the on-line travelling salesman

    NARCIS (Netherlands)

    Ausiello, G.; Feuerstein, E.; Leonardi, S.; Stougie, L.; Talamo, M.

    1999-01-01

    In this paper the problem of efficiently serving a sequence of requests presented in an on-line fashion located at points of a metric space is considered. We call this problem the On-Line Travelling Salesman Problem (OLTSP). It has a variety of relevant applications in logistics and robotics. We

  18. An algorithm for on-line price discrimination

    NARCIS (Netherlands)

    D.D.B. van Bragt; D.J.A. Somefun (Koye); E. Kutschinski; J.A. La Poutré (Han)

    2002-01-01

    textabstractThe combination of on-line dynamic pricing with price discrimination can be very beneficial for firms operating on the Internet. We therefore develop an on-line dynamic pricing algorithm that can adjust the price schedule for a good or service on behalf of a firm. This algorithm (a

  19. On-Line Voltage Stability Assessment based on PMU Measurements

    DEFF Research Database (Denmark)

    Garcia-Valle, Rodrigo; P. Da Silva, Luiz C.; Nielsen, Arne Hejde

    2009-01-01

    This paper presents a method for on-line monitoring of risk voltage collapse based on synchronised phasor measurement. As there is no room for intensive computation and analysis in real-time, the method is based on the combination of off-line computation and on-line monitoring, which are correlat...

  20. From Off-line to On-line Handwriting Recognition

    NARCIS (Netherlands)

    Lallican, P.; Viard-Gaudin, C.; Knerr, S.

    2004-01-01

    On-line handwriting includes more information on time order of the writing signal and on the dynamics of the writing process than off-line handwriting. Therefore, on-line recognition systems achieve higher recognition rates. This can be concluded from results reported in the literature, and has been

  1. On-line Learning of Prototypes and Principal Components

    NARCIS (Netherlands)

    Biehl, M.; Freking, A.; Hölzer, M.; Reents, G.; Schlösser, E.; Saad, David

    1998-01-01

    We review our recent investigation of on-line unsupervised learning from high-dimensional structured data. First, on-line competitive learning is studied as a method for the identification of prototype vectors from overlapping clusters of examples. Specifically, we analyse the dynamics of the

  2. Chromate-reducing activity of Hansenula polymorpha recombinant cells over-producing flavocytochrome b₂.

    Science.gov (United States)

    Smutok, Oleh; Broda, Daniel; Smutok, Halyna; Dmytruk, Kostyantyn; Gonchar, Mykhailo

    2011-04-01

    In spite of the great interest to studies of the biological roles of chromium, as well as the toxic influence of Cr(VI)-species on living organisms, the molecular mechanisms of chromate bioremediation remain vague. A reductive pathway resulting in formation of less toxic Cr(III)-species is suggested to be the most important among possible mechanisms for chromate biodetoxification. The yeast l-lactate:cytochrome c-oxidoreductase (flavocytochrome b(2), FC b(2)) has absolute specificity for l-lactate, yet is non-selective with respect to its electron acceptor. These properties allow us to consider the enzyme as a potential candidate for chromate reduction by living cells in the presence of l-lactate. A recombinant strain of thermotolerant, methylotrophic yeast Hansenula polymorpha with sixfold increased FC b(2) enzyme activity (up to 3μmolmin(-1)mg(-1) protein in cell-free extract) compared to the parental strain was used for approval our suggestion. The recombinant cells, stored in dried state, as well as living yeast cells were tested for chromate-reducing activity in vitro in the presence of l-lactate (as an electron donor for chromate reduction) and different low molecular weight, redox-active mediators facilitating electron transfer from the reduced form of the enzyme to chromate (as a final electron acceptor): dichlorophenolindophenol (DCPIP), Methylene blue, Meldola blue, and Nile blue. It was shown that the highest chromate-reducing activity of the cells was achieved in the presence of DCPIP. The ability of chromate to catch electrons from the reduced flavocytochrome b(2) was confirmed using purified enzyme immobilized on the surface of a platinum electrode. The increasing concentration of Cr(VI) resulted in a decrease of enzyme-mediated current generated on the electrode during l-lactate oxidation. The shift and drop in amplitude of the peak in the cyclic voltammogram are indicative of Cr(VI)-dependent competition between reaction of chromate with reduced FC

  3. Corrosion of chromatic conversion coatings on Aluminium Alloys in electrical and electronic equipment

    International Nuclear Information System (INIS)

    Razavi, R.Sh.; Shahrabi, T.; Mozafarnia, R.

    2002-01-01

    Chromate conversion coating is applied on aluminum 6061. The optimum conditions for chromate bath composition and immersion time are also obtained for standard requirements provision such as corrosion resistance in salt spray test, electrical resistance and coating quality. The applied coatings are electrochemically tested in sea and distilled water. According to Tafel and cyclic polarization curves, the protection mechanism are evaluated in said environments. This evaluation has shown the formation of passive film layer, contains chromate and alumina on the base. The proper behavior of corrosion and electrical conductivity is probably due to this mechanism

  4. Comparison of various clustered interaction regions with regard to chromatic and dynamic behavior

    International Nuclear Information System (INIS)

    Leemann, B.; Wrulich, A.

    1986-05-01

    Clustered interaction regions for the SSC may be preferable from the viewpoint of costs and operation. In going from distributed to clustered IR's the superperiodicity of the machine is reduced and therefore the number of resonances induced by chromaticity correcting sextupoles is increased. This break in symmetry may cause a reduction in dynamic stability. The chromatic and dynamic behavior of the bare lattice is investigated for various cluster configurations. That means only chromaticity correcting sextupoles have been included and no magnetic imperfection errors have been considered. Then, the dynamic apertures of lattices with various IR clustering schemes are compared when random magnetic imperfections are included

  5. Effect of Kombucha tea on chromate(VI)-induced oxidative stress in albino rats.

    Science.gov (United States)

    Sai Ram, M; Anju, B; Pauline, T; Dipti, P; Kain, A K; Mongia, S S; Sharma, S K; Singh, B; Singh, R; Ilavazhagan, G; Kumar, D; Selvamurthy, W

    2000-07-01

    The effect of Kombucha tea (KT) on oxidative stress induced changes in rats subjected to chromate treatment are reported. KT feeding alone did not show any significant change in malondialdehyde (MDA) and reduced glutathione (GSH) levels, but did enhance humoral response and delayed type of hypersensitivity (DTH) response appreciably over control animals. Chromate treatment significantly enhanced plasma and tissue MDA levels, decreased DTH response considerably, enhanced glutathione peroxidase and catalase activities; however, no change in GSH, superoxide dismutase and antibody titres was noticed. KT feeding completely reversed the chromate-induced changes. These results show that Kombucha tea has potent anti-oxidant and immunopotentiating activities.

  6. On-line and bulk analysis for the resource industries

    International Nuclear Information System (INIS)

    Lim, C.S.; Sowerby, B.D.; Tickner, J.R.; Madsen, I.C.

    2001-01-01

    Nuclear techniques are the basis of many CSIRO on-line and bulk analysis systems that are now widely used in the mineral and energy industries. The continuous analysis and rapid response of these systems have led to improved control of mining, processing and blending operations. This paper reviews recent developments in neutron, gamma-ray and X-ray techniques for on-line and bulk analysis by CSIRO Minerals including neutron techniques for the on-conveyor belt determination of the composition of cement raw meal, the on-line analysis of composition in pyrometallurgical applications, the on-conveyor belt determination of ash in coal, and the rapid and accurate determination of gold in bulk laboratory samples. The paper also discusses a new gamma-ray technique for the on-line determination of ash in coal and the application of X-ray diffraction techniques for the on-line determination of mineralogy in the cement industry

  7. Nonlinear systems

    National Research Council Canada - National Science Library

    Drazin, P. G

    1992-01-01

    This book is an introduction to the theories of bifurcation and chaos. It treats the solution of nonlinear equations, especially difference and ordinary differential equations, as a parameter varies...

  8. Nonlinear analysis

    CERN Document Server

    Gasinski, Leszek

    2005-01-01

    Hausdorff Measures and Capacity. Lebesgue-Bochner and Sobolev Spaces. Nonlinear Operators and Young Measures. Smooth and Nonsmooth Analysis and Variational Principles. Critical Point Theory. Eigenvalue Problems and Maximum Principles. Fixed Point Theory.

  9. Measurement uncertainty associated with chromatic confocal profilometry for 3D surface texture characterization of natural human enamel.

    Science.gov (United States)

    Mullan, F; Bartlett, D; Austin, R S

    2017-06-01

    To investigate the measurement performance of a chromatic confocal profilometer for quantification of surface texture of natural human enamel in vitro. Contributions to the measurement uncertainty from all potential sources of measurement error using a chromatic confocal profilometer and surface metrology software were quantified using a series of surface metrology calibration artifacts and pre-worn enamel samples. The 3D surface texture analysis protocol was optimized across 0.04mm 2 of natural and unpolished enamel undergoing dietary acid erosion (pH 3.2, titratable acidity 41.3mmolOH/L). Flatness deviations due to the x, y stage mechanical movement were the major contribution to the measurement uncertainty; with maximum Sz flatness errors of 0.49μm. Whereas measurement noise; non-linearity's in x, y, z and enamel sample dimensional instability contributed minimal errors. The measurement errors were propagated into an uncertainty budget following a Type B uncertainty evaluation in order to calculate the Standard Combined Uncertainty (u c ), which was ±0.28μm. Statistically significant increases in the median (IQR) roughness (Sa) of the polished samples occurred after 15 (+0.17 (0.13)μm), 30 (+0.12 (0.09)μm) and 45 (+0.18 (0.15)μm) min of erosion (Pchromatic confocal profilometry was from flatness deviations however by optimizing measurement protocols the profilometer successfully characterized surface texture changes in enamel from erosive wear in vitro. Copyright © 2017 The Academy of Dental Materials. All rights reserved.

  10. Chromate Adsorption on Selected Soil Minerals: Surface Complexation Modeling Coupled with Spectroscopic Investigation.

    Czech Academy of Sciences Publication Activity Database

    Veselská, V.; Fajgar, Radek; Číhalová, S.; Bolanz, R.M.; Göttlicher, J.; Steininger, R.; Siddique, J.A.; Komárek, M.

    2016-01-01

    Roč. 318, NOV 15 (2016), s. 433-442 ISSN 0304-3894 Institutional support: RVO:67985858 Keywords : surface complexation modeling * chromate * soil minerals Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.065, year: 2016

  11. Achromatic-chromatic colorimetric sensors for on-off type detection of analytes.

    Science.gov (United States)

    Heo, Jun Hyuk; Cho, Hui Hun; Lee, Jin Woong; Lee, Jung Heon

    2014-12-21

    We report the development of achromatic colorimetric sensors; sensors changing their colors from achromatic black to other chromatic colors. An achromatic colorimetric sensor was prepared by mixing a general colorimetric indicator, whose color changes between chromatic colors, and a complementary colored dye with no reaction to the targeted analyte. As the color of an achromatic colorimetric sensor changes from black to a chromatic color, the color change could be much easily recognized than general colorimetric sensors with naked eyes. More importantly, the achromatic colorimetric sensors enable on-off type recognition of the presence of analytes, which have not been achieved from most colorimetric sensors. In addition, the color changes from some achromatic colorimetric sensors (achromatic Eriochrome Black T and achromatic Benedict's solution) could be recognized with naked eyes at much lower concentration ranges than normal chromatic colorimetric sensors. These results provide new opportunities in the use of colorimetric sensors for diverse applications, such as harsh industrial, environmental, and biological detection.

  12. On the r-dynamic chromatic number of the corronation by complete graph

    Science.gov (United States)

    Indah Kristiana, Arika; Imam Utoyo, M.; Dafik

    2018-04-01

    In this paper we will study the r-dynamic chromatic number of the coronation by complete graph. A proper k-coloring of graph G such that the neighbors of any vertex v receive at least min{r, d(v)} different colors. The r-dynamic chromatic number, χ r (G) is the minimum k such that graph G has an r-dynamic k-coloring. We will obtain lower bound of the r-dynamic chromatic number of {χ }r({K}nȯ H), and {χ }r(Hȯ {K}m) We also study the exact value of the r-dynamic chromatic number of {χ }r({K}nȯ {S}m),{χ }r({K}nȯ {F}m),{χ }r({S}nȯ {K}m),{χ }r({F}nȯ {K}m) and {χ }r({K}nȯ {K}m) for m, n > 3.

  13. Characterization of the main error sources of chromatic confocal probes for dimensional measurement

    International Nuclear Information System (INIS)

    Nouira, H; El-Hayek, N; Yuan, X; Anwer, N

    2014-01-01

    Chromatic confocal probes are increasingly used in high-precision dimensional metrology applications such as roughness, form, thickness and surface profile measurements; however, their measurement behaviour is not well understood and must be characterized at a nanometre level. This paper provides a calibration bench for the characterization of two chromatic confocal probes of 20 and 350 µm travel ranges. The metrology loop that includes the chromatic confocal probe is stable and enables measurement repeatability at the nanometer level. With the proposed system, the major error sources, such as the relative axial and radial motions of the probe with respect to the sample, the material, colour and roughness of the measured sample, the relative deviation/tilt of the probe and the scanning speed are identified. Experimental test results show that the chromatic confocal probes are sensitive to these errors and that their measurement behaviour is highly dependent on them. (paper)

  14. ASSESSING CHILDREN'S EXPOSURES TO THE WOOD PRESERVATIVE CCA (CHROMATED COPPER ARSENATE) ON TREATED PLAYSETS AND DECKS

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for re...

  15. Understanding on-line community: the affordances of virtual space

    Directory of Open Access Journals (Sweden)

    Karen Ruhleder

    2002-01-01

    Full Text Available Increasing numbers of on-line venues for learning are emerging as virtual communities become more accessible and commonplace. This paper looks at one particular virtual community, an on-line degree programme at the University of Illinois, Urbana-Champaign, which offers an M.S. in Library and Information Science (called LEEP. It draws on a framework presented by Mynatt, et al. (1998, which provides a lens for talking about on-line community as a set of affordances. This framework is applied to illustrate the interactions, artefacts, and expectations that shape this community.

  16. An Approach to On-line Risk Assessment in NPP

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; O'Brien, J.

    1996-01-01

    Probabilistic Risk Assessment (PRA) can provide safety status information for a plant during different configurations; additional effort is needed to do this in real time for on-line operation. This paper describes an approach to use PRA to achieve these goals. A Risk Assessment On-Line (RAOL) application was developed to monitor maintenance (on-line and planned) activities. RAOL is based on the results from a full-scope PRA, engineering/operational judgment and incorporates a user friendly program interface approach. Results from RAOL can be used by planners or operations to effectively manage the level of risk by controlling the actual plant configuration. (author)

  17. On-line spectroscopy with thermal atomic beams

    International Nuclear Information System (INIS)

    Thibault, C.; Guimbal, P.; Klapisch, R.; Saint Simon, M. de; Serre, J.M.; Touchard, F.; Duong, H.T.; Jacquinot, P.; Juncar, P.

    1981-01-01

    On-line high resolution laser spectroscopy experiments have been performed in which the light from a cw tunable dye laser interacts at right angles with a thermal atomic beam. sup(76-98)Rb, sup(118-145)Cs and sup(208-213)Fr have been studied using the ionic beam delivered by the ISOLDE on-line mass separator at CERN while sup(20-31)Na and sup(38-47)K have been studied by setting the apparaturs directly on-line with the PS 20 GeV proton beam. The principle of the method is briefly explained and some results concerning nuclear structure are given. (orig.)

  18. Comparison of On-Line Maintenance Support Tools

    International Nuclear Information System (INIS)

    Simic, Z.; Follen, S. M.; Mikulicic, V.

    1998-01-01

    Modeling approach to on-line risk monitoring is today in a rapid developing phase. For that reason number of different solutions are available. This paper will attempt to present existing approaches to address on-line risk modeling problem Starting with description of on-line risk monitoring issues in general, then following by presentation of existing software tools (EPRI's Safety Monitor, Equipment Out of Service Monitor, and ORAM-SENTINEL) the current state of the art in this area will be demonstrated. Finally, conclusions and ideas will be outlined. (author)

  19. On-line analysis of reactor noise using time-series analysis

    International Nuclear Information System (INIS)

    McGevna, V.G.

    1981-10-01

    A method to allow use of time series analysis for on-line noise analysis has been developed. On-line analysis of noise in nuclear power reactors has been limited primarily to spectral analysis and related frequency domain techniques. Time series analysis has many distinct advantages over spectral analysis in the automated processing of reactor noise. However, fitting an autoregressive-moving average (ARMA) model to time series data involves non-linear least squares estimation. Unless a high speed, general purpose computer is available, the calculations become too time consuming for on-line applications. To eliminate this problem, a special purpose algorithm was developed for fitting ARMA models. While it is based on a combination of steepest descent and Taylor series linearization, properties of the ARMA model are used so that the auto- and cross-correlation functions can be used to eliminate the need for estimating derivatives. The number of calculations, per iteration varies lineegardless of the mee 0.2% yield strength displayed anisotropy, with axial and circumferential values being greater than radial. For CF8-CPF8 and CF8M-CPF8M castings to meet current ASME Code S acid fuel cells

  20. On-line monitoring of the crystallization process: relationship between crystal size and electrical impedance spectra

    International Nuclear Information System (INIS)

    Zhao, Yanlin; Yao, Jun; Wang, Mi

    2016-01-01

    On-line monitoring of crystal size in the crystallization process is crucial to many pharmaceutical and fine-chemical industrial applications. In this paper, a novel method is proposed for the on-line monitoring of the cooling crystallization process of L-glutamic acid (LGA) using electrical impedance spectroscopy (EIS). The EIS method can be used to monitor the growth of crystal particles relying on the presence of an electrical double layer on the charged particle surface and the polarization of double layer under the excitation of alternating electrical field. The electrical impedance spectra and crystal size were measured on-line simultaneously by an impedance analyzer and focused beam reflectance measurement (FBRM), respectively. The impedance spectra were analyzed using the equivalent circuit model and the equivalent circuit elements in the model can be obtained by fitting the experimental data. Two equivalent circuit elements, including capacitance ( C 2 ) and resistance ( R 2 ) from the dielectric polarization of the LGA solution and crystal particle/solution interface, are in relation with the crystal size. The mathematical relationship between the crystal size and the equivalent circuit elements can be obtained by a non-linear fitting method. The function can be used to predict the change of crystal size during the crystallization process. (paper)

  1. Characterisation of Vranec, Cabernet sauvignon and Merlot wines based on their chromatic and anthocyanin profiles

    OpenAIRE

    Dimitrovska Maja; Tomovska Elena; Bocevska Mirjana

    2013-01-01

    Wines of three different grape varieties, Vranec, Cabernet Sauvignon and Merlot were examined for their characterisation in terms of anthocyanin and chromatic profiles, total polyphenols and antioxidant potential. Total, monomeric, polymeric and copigmented anthocyanins were determined by spectrophotometry and the individual anthocyanin compounds were quantified using HPLC-DAD. Chromatic profile was evaluated according to colour density, hue, % red, % blue, % yellow and brilliance (% dA...

  2. Chelation in metal intoxication. VIII. Removal of chromium from organs of potassium chromate administered rats.

    Science.gov (United States)

    Behari, J R; Tandon, S K

    1980-03-01

    Some polyaminocarboxylic acids were examined for their ability to mobilize chromium from certain vital organs, their subcellular fractions, and blood cells of potassium chromate administered rats. Hexamethylene 1,6-diamino tetraacetic acid (TDTA), triethylene tetramine hexaacetic acid (TTHA), and ethylene diamine di (O-hydroxylphenyl acetic acid) (EDDHA) may be useful in preventing or reducing chromate toxicity. No definite relationship could be observed between the structure of the chelating agents and their chromium-removing capacity.

  3. Removal of chromate in a permeable reactive barrier using zero-valent iron

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Locht, T

    2002-01-01

    Chromate is a commonly found groundwater contaminant. Permeable reactive barriers containing zero-valent iron as iron filings are able to remove the chromate by a combined reduction/precipitation reaction. However, due to the passivation of the reduction capability of the iron surfaces by the pre......). Mixing in sand had no significant enhancing effect on the removal capacity, in contrast to a pH adjustment of the groundwater to pH 4, which significantly increased the removal capacity....

  4. Joint IQ Skew and Chromatic Dispersion Estimation for Coherent Optical Communication Receivers

    DEFF Research Database (Denmark)

    Medeiros Diniz, Júlio César; Porto da Silva, Edson; Piels, Molly

    2016-01-01

    A low-complexity scanning method for joint estimation of receiver IQ skew and chromatic dispersion is proposed. This method shows less than 1 ps skew error for a 1200-km 32-GBd DP-16QAM optical transmission experiment.......A low-complexity scanning method for joint estimation of receiver IQ skew and chromatic dispersion is proposed. This method shows less than 1 ps skew error for a 1200-km 32-GBd DP-16QAM optical transmission experiment....

  5. CHROMATE INHIBITION OF THE LOCALIZED CORROSION OF ALUMINUM: MEASUREMENTS OF ELECTROCHEMICAL TRANSIENTS

    International Nuclear Information System (INIS)

    SASAKI, K.; ISAACS, H.S.

    2001-01-01

    We investigated the inhibition by chromate ions of the localized corrosion of aluminum by electrochemical transient measurements. In agreement with other work, the measurements demonstrated that chromate is a cathodic inhibitor for aluminum in open circuit. The reduction of hexavalent chromium to trivalent chromium is assumed to take place on catalyzed sites of the surface. The resulting products inhibit oxygen reduction reactions at these sites, thereby retarding pitting corrosion

  6. Chromatic aberration compensation in numerical reconstruction of digital holograms by Fresnel-Bluestein propagation.

    Science.gov (United States)

    Hincapie, Diego; Velasquez, Daniel; Garcia-Sucerquia, Jorge

    2017-12-15

    In this Letter, we present a method for chromatic compensation in numerical reconstruction of digitally recorded holograms based on Fresnel-Bluestein propagation. The proposed technique is applied to correct the chromatic aberration that arises in the reconstruction of RGB holograms of both millimeter- and micrometer-sized objects. The results show the feasibility of this strategy to remove the wavelength dependence of the size of the numerically propagated wavefields.

  7. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models

    OpenAIRE

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-01

    Background In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared. Methods A Liou-Brennan-based IOL eye model was constructed using ZEMAX optical design software. Spherical IOLs with different diopters (AR40e, AMO Company, USA) were implanted; modulation transfer function (MTF) values at 3?mm of pupil diameter and...

  8. The sandstone's chromatic alteration of the florentine cultural heritage

    Science.gov (United States)

    Vettori, S.; Pecchioni, E.; Cantisani, E.; Ricci, M.; Fratini, F.; Garzonio, C. A.

    2012-04-01

    Pietra Serena is one of the materials more used in Florentine architecture. It is a sandstone that outcrops in the hills north of the city in the municipality of Fiesole and it has been employed mainly for ornamental purposes. This litotype belongs to the the Macigno Formation (Oligocene Upper- Miocene Lower) which consists of beds of turbiditic sandstones separated by pelitic levels which are the finest components of each single turbidity layer. Petrographically, Pietra Serena can be defined as a medium-coarse-grained greywacke made of quartz, feldspars, micas, fragments of metamorphic and magmatic rocks. The clayey matrix is quite abundant, mainly composed by illite, kaolinite and chlorite-vermiculite (present only in some quarries). It is well known that the processes of decay of the sandstones are related to the type of matrix, the amount of cement, the kind of clay minerals and to the pore size distribution, which lead to water infiltrations, swelling of the clay minerals, separation of the clayey matrix, with resulting exfoliation and peeling of the stone artefacts. Pietra Serena has a bluish-grey colour in fresh cut, but many times it is easily oxidized acquiring an ochraceous-reddish brown colour on buildings. Such changes in colour, appear to be due in part to the oxidation of iron, proceeding very quickly from the surface to the inside, though the cohesion is not affected. It is possible to hypothesize that the chromatic changes not necessarily involve a progressive state of alteration of the artefact, but they may often to represents a natural patina acquired with the time. Nevertheless it is necessary to remember that the oxidized layer and its hardness could also be the result of treatments performed in the past. In Florence, several monuments and buildings are affected by such phenomenon, in particular it is possible to note an intense and diffuse reddish colouring on the Pietra Serena utilized for columns and for façade's decorations. In this work

  9. The effects of luminance contribution from large fields to chromatic visual evoked potentials.

    Science.gov (United States)

    Skiba, Rafal M; Duncan, Chad S; Crognale, Michael A

    2014-02-01

    Though useful from a clinical and practical standpoint uniform, large-field chromatic stimuli are likely to contain luminance contributions from retinal inhomogeneities. Such contribution can significantly influence psychophysical thresholds. However, the degree to which small luminance artifacts influence the chromatic VEP has been debated. In particular, claims have been made that band-pass tuning observed in chromatic VEPs result from luminance intrusion. However, there has been no direct evidence presented to support these claims. Recently, large-field isoluminant stimuli have been developed to control for intrusion from retinal inhomogeneities with particular regard to the influence of macular pigment. We report here the application of an improved version of these full-field stimuli to directly test the influence of luminance intrusion on the temporal tuning of the chromatic VEP. Our results show that band-pass tuning persists even when isoluminance is achieved throughout the extent of the stimulus. In addition, small amounts of luminance intrusion affect neither the shape of the temporal tuning function nor the major components of the VEP. These results support the conclusion that the chromatic VEP can depart substantially from threshold psychophysics with regard to temporal tuning and that obtaining a low-pass function is not requisite evidence of selective chromatic activation in the VEP. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Influence of storage duration and processing on chromatic attributes and flavonoid content of moxa floss.

    Science.gov (United States)

    Lim, Min Yee; Huang, Jian; Zhao, Bai-xiao; Zou, Hui-qin; Yan, Yong-hong

    2016-01-01

    Moxibustion is an important traditional Chinese medicine therapy using heat from ignited moxa floss for disease treatment. The purpose of the present study is to establish a reproducible method to assess the color of moxa floss, discriminate the samples based on chromatic coordinates and explore the relationship between chromatic coordinates and total flavonoid content (TFC). Moxa floss samples of different storage years and production ratios were obtained from a moxa production factory in Henan Province, China. Chromatic coordinates (L*, a* and b*) were analyzed with an ultraviolet-visible spectrophotometer and the chroma (C*) and hue angle (h°) values were calculated. TFC was determined by a colorimetric method. Data were analyzed with correlation, principal component analysis (PCA). Significant differences in the chromatic values and TFC were observed among samples of different storage years and production ratios. Samples of higher production ratio displayed higher chromatic characteristics and lower TFC. Samples of longer storage years contained higher TFC. Preliminary separation of moxa floss production ratio was obtained by means of color feature maps developed using L*-a* or L*-b* as coordinates. PCA allowed the separation of the samples from their storage years and production ratios based on their chromatic characteristics and TFC. The use of a colorimetric technique and CIELAB coordinates coupled with chemometrics can be practical and objective for discriminating moxa floss of different storage years and production ratios. The development of color feature maps could be used as a model for classifying the color grading of moxa floss.

  11. Very-long-term and short-term chromatic adaptation: are their influences cumulative?

    Science.gov (United States)

    Belmore, Suzanne C; Shevell, Steven K

    2011-02-09

    Very-long-term (VLT) chromatic adaptation results from exposure to an altered chromatic environment for days or weeks. Color shifts from VLT adaptation are observed hours or days after leaving the altered environment. Short-term chromatic adaptation, on the other hand, results from exposure for a few minutes or less, with color shifts measured within seconds or a few minutes after the adapting light is extinguished; recovery to the pre-adapted state is complete in less than an hour. Here, both types of adaptation were combined. All adaptation was to reddish-appearing long-wavelength light. Shifts in unique yellow were measured following adaptation. Previous studies demonstrate shifts in unique yellow due to VLT chromatic adaptation, but shifts from short-term chromatic adaptation to comparable adapting light can be far greater than from VLT adaptation. The question considered here is whether the color shifts from VLT adaptation are cumulative with large shifts from short-term adaptation or, alternatively, does simultaneous short-term adaptation eliminate color shifts caused by VLT adaptation. The results show the color shifts from VLT and short-term adaptation together are cumulative, which indicates that both short-term and very-long-term chromatic adaptation affect color perception during natural viewing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. On-line methanol sensor system development for recombinant ...

    African Journals Online (AJOL)

    On-line methanol sensor system development for recombinant human serum ... of the methanol sensor system was done in a medium environment with yeast cells ... induction at a low temperature and a pH where protease does not function.

  13. On-line control systems in power plants

    International Nuclear Information System (INIS)

    Freymeyer, P.

    1981-01-01

    This report is a review of on-line control systems as a complex system connected with all problems like, development, planning, degree of automation, economics, service, quality and documentation. (orig.) [de

  14. Why do People Stop Playing On-Line Games?

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    2012-01-01

    The recent initial public offering of shares of Zynga, probably the most important on-line game provider, drew interest of potential investors but also of general public to their business model. What the most interested people learned so far is that if Zynga had not changed their accounting...... practice, they would be in red numbers for several months already. This is most likely caused by people stopping to play their games. This paper provides an estimate of what proportion of people, who played on-line games, already stopped playing them. Additionally, it analyzed the reasons why people...... stopped playing on-line games. It also compares Facebook and other on-line games....

  15. The Daresbury On-Line Isotope Separator (DOLIS)

    International Nuclear Information System (INIS)

    Grant, I.S.; Eastham, D.A.; Groves, J.; Tolfree, D.W.L.; Walker, P.M.; Green, V.R.; Rikovska, J.; Stone, N.J.; Hamilton, W.D.

    1987-01-01

    The isotope separator DOLIS, which is on-line to the Daresbury Laboratory's 20-MV tandem accelerator, is used to measure nuclear moments and decay schemes. Separated beams may be collected on a tape and transported to a counting station, implanted directly into a host lattice at on-line temperatures down to less than 10 mK, or allowed to interact with a collinear laser beam. The present status of DOLIS and its ancillary equipment is described

  16. The Daresbury on-line isotope separator (DOLIS)

    International Nuclear Information System (INIS)

    Grant, I.S.; Eastham, D.A.; Groves, J.; Tolfree, D.W.L.; Walker, P.M.; Green, V.R.; Rikovska, J.; Stone, N.J.; Hamilton, W.D.

    1987-01-01

    The isotope separator DOLIS, which is on-line to the Daresbury Laboratory's 20-MV tandem accelerator, is used to measure nuclear moments and decay schemes. Separated beams may be collected on a tape and transported to a counting station, implanted directly into a host lattice at on-line temperatures down to less than 10 mK, or allowed to interact with a collinear laser beam. The present status of DOLIS and its ancillary equipment is described. (orig.)

  17. Considerations in applying on-line IC techniques to BWR's

    International Nuclear Information System (INIS)

    Kaleda, R.J.

    1992-01-01

    Ion-Chromatography (IC) has moved from its traditional role as a laboratory analytical tool to a real time, dynamic, on-line measurement device to follow ppb and sub-ppb concentrations of deleterious impurities in nuclear power plants. Electric Power Research Institute (EPRI), individual utilities, and industry all have played significant roles in effecting the transition. This paper highlights considerations and the evolution in current on-line Ion Chromatography systems. The first applications of on-line techniques were demonstrated by General Electric (GE) under EPRI sponsorship at Rancho Seco (1980), Calvert Cliffs, and McGuire nuclear units. The primary use was for diagnostic purposes. Today the on-line IC applications have been expanded to include process control and routine plant monitoring. Current on-line IC's are innovative in design, promote operational simplicity, are modular for simplified maintenance and repair, and use field-proven components which enhance reliability. Conductivity detection with electronic or chemical suppression and spectrometric detection techniques are intermixed in applications. Remote multi-point sample systems have addressed memory effects. Early applications measured ionic species in the part per billion range. Today reliable part per trillion measurements are common for on-line systems. Current systems are meeting the challenge of EPRI guideline requirements. Today's on-line IC's, with programmed sampling systems, monitor fluid streams throughout a power plant, supplying data that can be trended, stored and retrieved easily. The on-line IC has come of age. Many technical challenges were overcome to achieve today's IC

  18. On-line mixture-based alternative to logistic regression

    Czech Academy of Sciences Publication Activity Database

    Nagy, Ivan; Suzdaleva, Evgenia

    2016-01-01

    Roč. 26, č. 5 (2016), s. 417-437 ISSN 1210-0552 R&D Projects: GA ČR GA15-03564S Institutional support: RVO:67985556 Keywords : on-line modeling * on-line logistic regression * recursive mixture estimation * data dependent pointer Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.394, year: 2016 http://library.utia.cas.cz/separaty/2016/ZS/suzdaleva-0464463.pdf

  19. Nonlinear optimization

    CERN Document Server

    Ruszczynski, Andrzej

    2011-01-01

    Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates the theory and the methods of nonlinear optimization in a unified, clear, and mathematically rigorous fashion, with detailed and easy-to-follow proofs illustrated by numerous examples and figures. The book covers convex analysis, the theory of optimality conditions, duality theory, and numerical methods for solving unconstrained and constrained optimization problems. It addresses not only classical material but also modern top...

  20. Microporous uranyl chromates successively formed by evaporation from acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Siidra, Oleg I.; Nazarchuk, Evgeny V.; Bocharov, Sergey N.; Kayukov, Roman A. [St. Petersburg State Univ. (Russian Federation). Dept. of Crystallography; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften

    2018-04-01

    The first microporous framework structures containing uranium and chromium have been synthesized and characterized. Rb{sub 2}[(UO{sub 2}){sub 2}(CrO{sub 4}){sub 3}(H{sub 2}O){sub 2}](H{sub 2}O){sub 3} (1) was crystallized from uranyl chromate solution by evaporation. Further evaporation led to increased viscosity of the solution and overgrowing of Rb{sub 2}[(UO{sub 2}){sub 2}(CrO{sub 4}){sub 3}(H{sub 2}O)](H{sub 2}O) (2) on the crystals of 1. With respect to 1, the framework of 2 is partially dehydrated. Both frameworks differ compositionally by only one water molecule, but this seemingly small difference affects significantly the pore size and overall structural topology of the frameworks, which present very different flexibility of the U-O-Cr links. These are rigid in the pillared framework of 1, in contrast to 2 where the U-O-Cr angles range from 126.3 to 168.2 , reflecting the substantial flexibility of Cr-O-U connections which make them comparable to the corresponding Mo-O-U links in uranyl molybdates.

  1. Crystalline lens thickness determines the perceived chromatic difference in magnification.

    Science.gov (United States)

    Chen, Yun; Schaeffel, Frank

    2014-03-01

    Since the origin of the high interindividual variability of the chromatic difference in retinal image magnification (CDM) in the human eye is not well understood, optical parameters that might determine its magnitude were studied in 21 healthy subjects with ages ranging from 21 to 58 years. Two psychophysical procedures were used to quantify CDM. They produced highly correlated results. First, a red and a blue square, presented on a black screen, had to be matched in size by the subjects with their right eyes. Second, a filled red and blue square, flickering on top of each other at 2 Hz, had to be adjusted in perceived brightness and then in size to minimize the impression of flicker. CDM varied widely among subjects from 0.0% to 3.6%. Biometric ocular parameters were measured with low coherence interferometry and crystalline lens tilt and decentration with a custom-built Purkinjemeter. Correlations were studied between CDM and corneal power, anterior chamber depth, lens thickness, lens tilt and lens decentration, and vitreous chamber depths. Lens thickness was found significantly correlated with CDM and accounted for 64% of its variance. Vertical lens tilt and decentration were also significantly correlated. It was also found that CDM increased by 3.5% per year, and part of this change can be attributed to the age-related increase in lens thickness.

  2. Selection of Optical Glasses Using Buchdahl's Chromatic Coordinate

    Science.gov (United States)

    Griffin, DeVon W.

    1999-01-01

    This investigation attempted to extend the method of reducing the size of glass catalogs to a global glass selection technique with the hope of guiding glass catalog offerings. Buchdahl's development of optical aberration coefficients included a transformation of the variable in the dispersion equation from wavelength to a chromatic coordinate omega defined as omega = (lambda - lambda(sub 0))/ 1 + 2.5(lambda - lambda(sub 0)) where lambda is the wavelength at which the wavelength is calculated and lambda(sub 0) is a base wavelength about which the expansion is performed. The advantage of this approach is that the dispersion equation may be written in terms of a simple power series and permits direct calculation of dispersion coefficients. While several promising examples were given, a systematic application of the technique to an entire glass catalog and analysis of the subsequent predictions was not performed. The goal of this work was to apply the technique in a systematic fashion to glasses in the Schoft catalog and assess the quality of the predictions.

  3. Gravity Chromatic Imaging of the Eta Car's Core

    Science.gov (United States)

    Sanchez-Bermudez, Joel

    2018-04-01

    Eta Car is one of the most massive, and intriguing, Luminous Blue Variables known. In its core resides a binary with a 5.54 years orbital period. Visible, infrared, and X-raobservations suggest that the primary star exhibits a very dense wind with a terminal velocity of about 420 km/s, while the secondary shows a much faster and less dense wind with a terminal velocity of 3000 km/s. The wind-wind collision zone at the core of Eta Car is thus a complex region that deserves a detailed study to understand the effect of the binary interaction in the evolution of the system. Here, we will present a unique imaging campaign with GRAVITY/VLTI of the Eta Car's core. The superb quality of our interferometric data, together with state-of-the-art image reconstruction techniques, allowed us to obtain, with milliarcsecond resolution, continuum and chromatic images cross the BrG and HeI lines in the Eta Car K-band spectrum (R 4000). These new data together with models of the primary wind of Eta Car has letting us to characterize the spatial distribution of the dust and gas in the inner 40 AU wind-wind collision zone of the target.

  4. Refractive and diffractive neutron optics with reduced chromatic aberration

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, S.O., E-mail: stefan.poulsen@northwestern.edu [NEXMAP, Department of Physics, Technical University of Denmark, Anker Engelunds Vej 1, 2800 Kgs. Lyngby (Denmark); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Poulsen, H.F. [NEXMAP, Department of Physics, Technical University of Denmark, Anker Engelunds Vej 1, 2800 Kgs. Lyngby (Denmark); Bentley, P.M. [European Spallation Source ESS AB, Box 176, 221 00 Lund (Sweden)

    2014-12-11

    Thermal neutron beams are an indispensable tool in physics research. The spatial and the temporal resolution attainable in experiments are dependent on the flux and collimation of the neutron beam which remain relatively poor, even for modern neutron sources. These difficulties may be mitigated by the use of optics for focusing and imaging. Refractive and diffractive optical elements, e.g. compound refractive lenses and Fresnel zone plates, are attractive due to their low cost, and simple alignment. These optical elements, however, suffer from chromatic aberration, which limit their effectiveness to highly monochromatic beams. This paper presents two novel concepts for focusing and imaging non-monochromatic thermal neutron beams with well-known optical elements: (1) a fast mechanical transfocator based on a compound refractive lens, which actively varies the number of individual lenses in the beam path to focus and image a time-of-flight beam, and (2) a passive optical element consisting of a compound refractive lens, and a Fresnel zone plate, which may focus and image both continuous and pulsed neutron beams.

  5. Pigment chromatic adaptation in Cyclotella caspia Grunow (Bacillariophyta

    Directory of Open Access Journals (Sweden)

    Donato Seiji Abe

    1991-01-01

    Full Text Available The diatom Cyclotella caspia Grunow, isolated from surface waters of the Ubatuba region (São Paulo State, Brazil was submitted to different light spectral distributions for examination of its adaptative response. Growth rate and the photosynthetic pigments chlorophyll a, chlorophyll c, carotenoids and phaeopigments were measured under white, blue and red light of the same intensity (8 and 20 µE.cm-2.s-1. Growth rate increased under blue light while red light increased chl a concentration. The relative proportion of chl a and carotenoids did not change, demonstrating the absence of complementary chromatic adaptation.A diatomácea Cyclotella caspia Grunow, isolada de águas superficiais da região de Ubatuba (Estado de São Paulo, Brasil, foi submetida a diferentes intervalos espectrais de luz com a finalidade de se examinar sua resposta adaptativa. Foram medidos a taxa de crescimento e os pigmentos fotossintéticos clorofila a, clorofila c, carotenóides e feopigmentos, sob luz branca, azul e vermelha de mesmas intensidades (8 e 20 µE.cm-2.s-1. A taxa de crescimento aumentou sob luz azul, sendo que a concentração de clorofila a aumentar sob luz vermelha. A proporção relativa de clα e carotenóides não variou, demonstrando a ausência de adapatação cromática complementar.

  6. Processing of chromatic information in a deep convolutional neural network.

    Science.gov (United States)

    Flachot, Alban; Gegenfurtner, Karl R

    2018-04-01

    Deep convolutional neural networks are a class of machine-learning algorithms capable of solving non-trivial tasks, such as object recognition, with human-like performance. Little is known about the exact computations that deep neural networks learn, and to what extent these computations are similar to the ones performed by the primate brain. Here, we investigate how color information is processed in the different layers of the AlexNet deep neural network, originally trained on object classification of over 1.2M images of objects in their natural contexts. We found that the color-responsive units in the first layer of AlexNet learned linear features and were broadly tuned to two directions in color space, analogously to what is known of color responsive cells in the primate thalamus. Moreover, these directions are decorrelated and lead to statistically efficient representations, similar to the cardinal directions of the second-stage color mechanisms in primates. We also found, in analogy to the early stages of the primate visual system, that chromatic and achromatic information were segregated in the early layers of the network. Units in the higher layers of AlexNet exhibit on average a lower responsivity for color than units at earlier stages.

  7. Effect of the gamma radiation in hydrotalcite with chromates

    International Nuclear Information System (INIS)

    Martinez G, S.; Bulbulian, S.

    2004-01-01

    At the moment the generation of radioactive wastes is topic of numerous studies. In this work was retained anionic material, chromates, in hydrotalcite that are anionic exchangers. It was proposed to warm the HT at different temperatures of 600 C up to 1200 C with the purpose of immobilizing the chromium inside the hydrotalcite. To high temperatures (1000 and 1200 C) it was formed one spinel (MgCr 2 O 4 ) that is a very stable compound. It was found that when increasing the heating temperature, the anions are retained strongly. The immobilization of the Cr was determined through the chromium lixiviation with solutions 1N and 5N of NaCl. Also it was studied the effect of the radiation on the heated materials. The radiation dose used for it was of 1000 and 6000 kGy. The results show that for the calcined samples at 1000 and 1200 C irradiated or no irradiated, the chromium is strongly retained in form of spinels that is the structure formed after the calcination of the material. (Author)

  8. TREATMENT TESTS FOR EX SITU REMOVAL OF CHROMATE & NITRATE & URANIUM (VI) FROM HANFORD (100-HR-3) GROUNDWATER FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    BECK MA; DUNCAN JB

    1994-01-03

    This report describes batch and ion exchange column laboratory scale studies investigating ex situ methods to remove chromate (chromium [VI]), nitrate (NO{sub 3}{sup -}) and uranium (present as uranium [VI]) from contaminated Hanford site groundwaters. The technologies investigated include: chemical precipitation or coprecipitation to remove chromate and uranium; and anion exchange to remove chromate, uranium and nitrate. The technologies investigated were specified in the 100-HR-3 Groundwater Treatability Test Plan. The method suggested for future study is anion exchange.

  9. Fluctuations in the prevalence of chromate allergy in Denmark and exposure to chrome-tanned leather.

    Science.gov (United States)

    Carøe, Caroline; Andersen, Klaus E; Thyssen, Jacob P; Mortz, Charlotte G

    2010-12-01

    A recent Danish study showed a significant increase in the prevalence of chromate contact allergy after the mid-1990s, probably as a result of exposure to leather products. To reproduce the results by analysing data from the period 1992-2009 at Odense University Hospital, Denmark. The temporal development in the occurrence of chromate contact allergy and assumed causative exposures were investigated. A retrospective analysis of patch test data was performed (n = 8483), and medical charts from patients with chromate allergy (n = 231) were reviewed. Comparisons were made using the χ(2) -test. A test of the reproducibility of the TRUE Test® was also performed. Logistic regression analyses were used to test for associations. No significant changes in the prevalence or exposure sources of chromate allergy during 1992-2009 were identified. Leather shoes (24.4%) were the most frequent exposure sources in chromate allergy, and were mainly registered in women, although the difference between men and women was not significant (P = 0.07). Cement and leather glove exposure occurred significantly more often in men than in women (P = 0.002). Foot dermatitis (40.3%) was the most frequent anatomical location, apart from hand eczema (60.6%). The reproducibility of the TRUE Test® was 93.3%. Apart from hand eczema, the most frequent clinical picture of chromate allergy was foot dermatitis caused by leather shoe exposure. A tendency for an increasing prevalence of chromate contact allergy from 1997 was shown, but no significant change was detectable. © 2010 John Wiley & Sons A/S.

  10. On-line maintenance PSA support at NPP Krsko

    International Nuclear Information System (INIS)

    Prosen, R.; Vrbanic, I.; Kastelan, M.

    2000-01-01

    In 1997 Krsko NPP initiated the on-line maintenance (OLM) practice. On-line maintenance constitutes of corrective activities, preventive activities, surveillance activities, tests and inspections, as well as calibrations and modifications, taking place during the normal power operations. The on-line maintenance is a multidisciplinary process consisting of activity specification, planning, and preparation and performing of the OLM activity of interest. The primary role of the PSA group is to assess from the r isk perspective , using the plant-specific NEK PSA model, system unavailability and the impact to the plant operational risk. The intent is to support planning of the on-line maintenance activities from the risk perspective. The risk evaluation of the OLM activities is based on the probability of core damage evaluation for the defined discrete plant configuration states, determined by the OLM activities. Within this application, the optimized, plant-specific PSA model is used on Risk Spectrum platform. To perform the risk assessment of the on-line maintenance activities, first the systems to be affected are defined based on the planned OLM activities. The next important step is the assessment of the planned work schedule. To define the final schedule, the co-ordination and optimizing the planned OLM activities needs activation of all participating departments, supported also from PSA group. The P3 (i.e. Primavera) planning tool system windows are defined for different systems and groups of systems, and the activities are sorted in particular weeks according to these windows. (author)

  11. OLDASS: On-line data acquisition system at SF cyclotron

    International Nuclear Information System (INIS)

    Omata, Kazuo; Yasue, Masaharu; Hamagaki, Hideki

    1982-01-01

    The on-line data acquisition system in the Institute for Nuclear Study, the University of Tokyo, is composed of 2 systems of Fujitsu mini-computer PFU-400 for data processing at the high energy synchrotron and one system of that computer for low energy cyclotron as terminals, the host computer being M 180 II AD of the same company. This system has been developed to have the features of being the on-line system capable of following the improvement of host computer performance, being capable of developing the on-line programmes of other experimenting groups in parallel with batch jobs or the operation of the on-line system, and capable of developing programmes using FORTRAN. The result of about 220 KB/s was obtained for the data transfer rate between the programmes of the host computer and terminals, and this fulfilled the aimed performance. The terminal system on the low energy side is provided with an ADC interface and a display interface specified particularly in addition to the miniature computer PFU400 and standard I/O devices of the manufacture. The accumulating type graphic display of the I/O devices can be switched to be connected to the host computer, and immediately displays the results transferred to the host computer and analyzed. Hard copy is also available. The above hardware and software are explained. The on-line system insures 80 K bytes of the total memory of 224 K bytes for data area. (Wakatsuki, Y.)

  12. Sport Management Taught On-Line: A Discussion

    Directory of Open Access Journals (Sweden)

    William F. Stier Jr

    2009-01-01

    Full Text Available An introduction to the world of on-line courses (distance education/learning is presented. In addition, the world of on-line learning, as it pertains to sport management, is examined within the framework of (a pedagogy, (b finances,(c assessment, and (d choosing to transition from the traditional classroom to on-line learning. Pertinent points relative to each of the four categories are presented from the literature. In an effort to stimulate thought and discussion to the subject of on-line learning for sport management programs/courses the authors provide their reactions to the literature points by presenting their comments/reactions from a sport management perspective. Sport management professors and administrators are encouraged to critically examine the feasibility of such on-line courses (distance education/learning within their own curricula while maintaining an appropriate framework revolving around sound theoretical instructional strategies, methods as well as appropriate use of instructional tools, including but not limited to, computersand the WWW.

  13. Tune-shift with amplitude due to nonlinear kinematic effect

    CERN Document Server

    Wan, W

    1999-01-01

    Tracking studies of the Muon Collider 50 on 50 GeV collider ring show that the on-momentum dynamic aperture is limited to around 10 sigma even with the chromaticity sextupoles turned off. Numerical results from the normal form algorithm show that the tune-shift with amplitude is surprisingly large. Both analytical and numerical results are presented to show that nonlinear kinematic effect originated from the large angles of particles in the interaction region is responsible for the large tune-shift which in turn limits the dynamic aperture. A comparative study of the LHC collider ring is also presented to demonstrate the difference between the two machines. (14 refs).

  14. Impact of chromated copper arsenate (CCA) in wood mulch.

    Science.gov (United States)

    Townsend, Timothy G; Solo-Gabriele, Helena; Tolaymat, Thabet; Stook, Kristin

    2003-06-20

    The production of landscape mulch is a major market for the recycling of yard trash and waste wood. When wood recovered from construction and demolition (C&D) debris is used as mulch, it sometimes contains chromated copper arsenate (CCA)-treated wood. The presence of CCA-treated wood may cause some potential environmental problems as a result of the chromium, copper, and arsenic present. Research was performed to examine the leachability of the three metals from a variety of processed wood mixtures in Florida. The mixtures tested included mixed wood from C&D debris recycling facilities and mulch purchased from retail outlets. The synthetic precipitation leaching procedure (SPLP) was performed to examine the leaching of chromium, copper and arsenic. Results were compared to Florida's groundwater cleanup target levels (GWCTLs). Eighteen of the 22 samples collected from C&D debris processing facilities leached arsenic at concentrations greater than Florida's GWCTL of 50 microg/l. The mean leachable arsenic concentration for the C&D debris samples was 153 microg/l with a maximum of 558 microg/l. One of the colored mulch samples purchased from a retail outlet leached arsenic above 50 microg/l, while purchased mulch samples derived from virgin materials did not leach detectable arsenic (<5 microg/l). A mass balance approach was used to compute the potential metal concentrations (mg/kg) that would result from CCA-treated wood being present in wood mulch. Less than 0.1% CCA-treated wood would cause a mulch to exceed Florida's residential clean soil guideline for arsenic (0.8 mg/kg).

  15. Accelerated redox reaction between chromate and phenolic pollutants during freezing.

    Science.gov (United States)

    Ju, Jinjung; Kim, Jaesung; Vetráková, Ľubica; Seo, Jiwon; Heger, Dominik; Lee, Changha; Yoon, Ho-Il; Kim, Kitae; Kim, Jungwon

    2017-05-05

    The redox reaction between 4-chlorophenol (4-CP) and chromate (Cr(VI)) (i.e., the simultaneous oxidation of 4-CP by Cr(VI) and reduction of Cr(VI) by 4-CP) in ice (i.e., at -20°C) was compared with the corresponding reaction in water (i.e., at 25°C). The redox conversion of 4-CP/Cr(VI), which was negligible in water, was significantly accelerated in ice. This accelerated redox conversion of 4-CP/Cr(VI) in ice is ascribed to the freeze concentration effect occurring during freezing, which excludes solutes (i.e., 4-CP and Cr(VI)) and protons from the ice crystals and subsequently concentrates them in the liquid brine. The concentrations of Cr(VI) and protons in the liquid brine were confirmed by measuring the optical image and the UV-vis absorption spectra of cresol red (CR) as a pH indicator of frozen solution. The redox conversion of 4-CP/Cr(VI) was observed in water when the concentrations of 4-CP/protons or Cr(VI)/protons increased by 100/1000-fold. These results corroborate the freeze concentration effect as the reason for the accelerated redox conversion of 4-CP/Cr(VI) in ice. The redox conversion of various phenolic pollutants/Cr(VI) and 4-CP/Cr(VI) in real wastewater was successfully achieved in ice, which verifies the environmental relevance and importance of freezing-accelerated redox conversion of phenolic pollutants/Cr(VI) in cold regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Initiating Events Modeling for On-Line Risk Monitoring Application

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.

    1998-01-01

    In order to make on-line risk monitoring application of Probabilistic Risk Assessment more complete and realistic, a special attention need to be dedicated to initiating events modeling. Two different issues are of special importance: one is how to model initiating events frequency according to current plant configuration (equipment alignment and out of service status) and operating condition (weather and various activities), and the second is how to preserve dependencies between initiating events model and rest of PRA model. First, the paper will discuss how initiating events can be treated in on-line risk monitoring application. Second, practical example of initiating events modeling in EPRI's Equipment Out of Service on-line monitoring tool will be presented. Gains from application and possible improvements will be discussed in conclusion. (author)

  17. Strengthening weak ties through on-line gaming

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana Virginia; Kirchner, Kathrin

    On-line gaming became widespread in the last couple of years. The aim of the research presented in the paper is to figure out to what extent does game playing helps to strengthen weak ties and what additional factors influence this process. The approach is rather exploratory – some factors...... are grounded in theory, some are new. These factors are age, gender, place of origin, number of their Facebook connections (friends in Facebook terminology), the amount of time they are on Facebook, the amount of time they keep the Facebook site open, the amount of time they play on-line games, and the reasons...... for starting to play on-line games. Regarding the latter, we chose to focus only on escapist reasons....

  18. Thermographic Sensing For On-Line Industrial Control

    Science.gov (United States)

    Holmsten, Dag

    1986-10-01

    It is today's emergence of thermoelectrically cooled, highly accurate infrared linescanners and imaging systems that has definitely made on-line Infraread Thermography (IRT) possible. Specifically designed for continuous use, these scanners are equipped with dedicated software capable of monitoring and controlling highly complex thermodynamic situations. This paper will outline some possible implications of using IRT on-line by describing some uses of this technology in the steel-making (hot rolling) and automotive industries (machine-vision). A warning is also expressed that IRT technology not originally designed for automated applications e.g. high resolution, imaging systems, should not be directly applied to an on-line measurement situation without having its measurement resolution, accuracy and especially its repeatability, reliably proven. Some suitable testing procedures are briefly outlined at the end of the paper.

  19. An on-line monitoring system for navigation equipment

    Science.gov (United States)

    Wang, Bo; Yang, Ping; Liu, Jing; Yang, Zhengbo; Liang, Fei

    2017-10-01

    Civil air navigation equipment is the most important infrastructure of Civil Aviation, which is closely related to flight safety. In addition to regular flight inspection, navigation equipment's patrol measuring, maintenance measuring, running measuring under special weather conditions are the important means of ensuring aviation flight safety. According to the safety maintenance requirements of Civil Aviation Air Traffic Control navigation equipment, this paper developed one on-line monitoring system with independent intellectual property rights for navigation equipment, the system breakthroughs the key technologies of measuring navigation equipment on-line including Instrument Landing System (ILS) and VHF Omni-directional Range (VOR), which also meets the requirements of navigation equipment ground measurement set by the ICAO DOC 8071, it provides technical means of the ground on-line measurement for navigation equipment, improves the safety of navigation equipment operation, and reduces the impact of measuring navigation equipment on airport operation.

  20. On-line calculation of 3-D power distribution

    International Nuclear Information System (INIS)

    Park, Y. H.; In, W. K.; Park, J. R.; Lee, C. C.; Auh, G. S.

    1996-01-01

    The 3-D power distribution synthesis scheme was implemented in Totally Integrated Core Operation Monitoring System (TICOMS), which is under development as the next generation core monitoring system. The on-line 3-D core power distribution obtained from the measured fixed incore detector readings is used to construct the hot pin power as well as the core average axial power distribution. The core average axial power distribution and the hot pin power of TICOMS were compared with those of the current digital on-line core monitoring system, COLSS, which construct the core average axial power distribution and the pseudo hot pin power. The comparison shows that TICOMS results in the slightly more accurate core average axial power distribution and the less conservative hot pin power. Therefore, these results increased the core operating margins. In addition, the on-line 3-D power distribution is expected to be very useful for the core operation in the future

  1. Approaches for on-line coupling of extraction and chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Hyoetylaeinen, Tuulia; Riekkola, Marja-Liisa [Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014, Helsinki (Finland)

    2004-04-01

    This review provides an overview of the approaches available in order to perform on-line coupling of various extraction techniques with liquid and gas chromatography, for the analysis of semivolatile and nonvolatile analytes in liquid and solid samples. The main focus is on the instrumental set-up of these techniques. Selected real applications are described by way of illustration. The extraction methods suitable for on-line coupling covered in this review are: liquid-liquid extraction, solid-phase extraction, membrane-based techniques, pressurised liquid extraction, supercritical fluid extraction, and microwave- and sonication-assisted extractions. The following systems are not covered in this review: on-line coupled solid-phase extraction-liquid chromatography, purge-and-trap-GC, and membrane extraction with a sorbent interface-GC. (orig.)

  2. UNISOR on-line nuclear orientation facility (UNISOR/NOF)

    International Nuclear Information System (INIS)

    Girit, I.C.; Alton, G.D.; Bingham, C.R.; Carter, H.K.; Simpson, M.L.; Cole, J.D.; Croft, W.L.; Hamilton, J.H.; Jones, E.F.; Gore, P.M.; Kormicki, J.; Xie, H.; Kern, B.D.; Krane, K.S.; Xu, Y.S.; Mantica, P.F. Jr.; Zimmermann, B.E.; Nettles, W.G.; Zganjar, E.F.; Kortelahti, M.O.; Newbolt, W.B.

    1988-01-01

    The UNISOR on-line nuclear orientation facility (UNISOR/NOF) consists of a 3 He- 4 He dilution refrigerator on line to the isotope separator. Nuclei are implanted directly into a target foil which is soldered to the bottom accessed cold finger of the refrigerator. A 1.5 T superconducting magnet polarizes the ferromagnetic target foils and determines the axis of symmetry. Up to eight gamma detectors can be positioned around the refrigerator, each 9 cm from the target. A unique feature of this system is that the k=4 term in the directional distribution function can be directly and unambigously deduced so that a single solution for the mixing ratio can be found. The first on-line experiment at this facility reported here was a study of the decay of the 191 Hg and 193 Hg isotopes. (orig.)

  3. Making the most of on-line recruiting.

    Science.gov (United States)

    Cappelli, P

    2001-03-01

    Ninety percent of large U.S. companies are already recruiting via the Internet. By simply logging on to the Web, company recruiters can locate vast numbers of qualified candidates for jobs at every level, screen them in minutes, and contact the most promising ones immediately. The payoffs can be enormous: it costs substantially less to hire someone on-line, and the time saved is equally great. In this article, Peter Cappelli examines some of the emerging service providers and technologies--matchmakers, job boards, hiring management systems software, and applicant-screening mechanisms that test skills and record interests. He also looks at some of the strategies companies are adopting as they enter on-line labor markets. Recruiting needs to be refashioned to resemble marketing, he stresses. Accordingly, smart companies are designing Web pages, and even product ads, with potential recruits in mind. They're giving line managers authority to hire so that candidates in cyberspace aren't lost. They're building internal on-line job networks to retain talent. Integrating recruiting efforts with overall marketing campaigns, especially through coordination and identification with the company's brand, is the most important thing companies can do to ensure success in on-line hiring. Along the way, Cappelli sounds two cautionary notes. First, a human touch, not electronic contact, is vital in the last steps of a successful hiring process. Second, companies must make sure that on-line testing and hiring criteria do not discriminate against women, disabled people, workers over 40, or members of minority groups. When competition for talent is fierce, companies that master the art and science of on-line recruiting will be the ones that attract and keep the best people.

  4. The User-friendly On-Line Diffusion Chamber

    CERN Document Server

    Aviles Acosta, Jaime

    2015-01-01

    The On-Line Diffusion Chamber is a stand-alone apparatus built to carry out short-live radiotracer diffusion studies. The availability of the on-demand production of isotopes in the ISOLDE facility, and the design of the apparatus to streamline the implantation process, annealing treatment, ion gun ablation with a tape transport system, and radiation intensity measurement with a Ge gamma detector all in the same apparatus, gives the On-Line Diffusion Chamber a unique ability to studies with short-lived radioisotopes or isomer states that are not possible in any other facility in the world.

  5. The rationalization of desulfurization by on-line analysis

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y; Kohmura, S; Taketomi, H; Matsumura, S; Sasaki, Y

    1986-01-01

    Nippon Kokan uses the Takahax and Sulfiban processes for the desulfurization of coke oven gas. The authors outline the Sulfiban Process and describe a recently developed system for the on-line determination of H/sub 2/S in coke oven gas, and of CO/sub 2/ and monoethanolamine (MEA) in the wash oil. This new on-line analysis system has proved effective in rationalizing the Sulfiban Process via lower MEA production costs and decreased power consumption. The introduction of a computerized control system is now being studied. 7 figs., 4 tabs.

  6. 5th Computer Science On-line Conference

    CERN Document Server

    Senkerik, Roman; Oplatkova, Zuzana; Silhavy, Petr; Prokopova, Zdenka

    2016-01-01

    This volume is based on the research papers presented in the 5th Computer Science On-line Conference. The volume Artificial Intelligence Perspectives in Intelligent Systems presents modern trends and methods to real-world problems, and in particular, exploratory research that describes novel approaches in the field of artificial intelligence. New algorithms in a variety of fields are also presented. The Computer Science On-line Conference (CSOC 2016) is intended to provide an international forum for discussions on the latest research results in all areas related to Computer Science. The addressed topics are the theoretical aspects and applications of Computer Science, Artificial Intelligences, Cybernetics, Automation Control Theory and Software Engineering.

  7. Comparison of Current On-line Payment Technologies

    OpenAIRE

    Mandadi, Ravi

    2006-01-01

    The purpose of this thesis work was to make a survey of current on-line payment technologies and find out which are they and how do they work? Compare and analyze them from a security point of view, as well as a usability point of view. What is good? What is bad? What is lacking? To achieve this purpose, an overview of the current on-line payment technologies was acquired through academic books and papers, Internet sites, magazines. Basic cryptographic and security related techniques were stu...

  8. An on-line adaptive core monitoring system

    International Nuclear Information System (INIS)

    Verspeek, J.A.; Bruggink, J.C.; Karuza, J.

    1997-01-01

    An on-line core monitoring system has been in operation for three years in the Dodewaard Nuclear Power Plant. The core monitor uses the on-line measured reactor data as an input for a power distribution calculation. The measurements are frequently performed. The system is used for monitoring as well as for predicting purposes. The limiting thermal hydraulic parameters are monitored as well as the pellet-clad interaction limits. The data are added to a history file used for cycle burn-up calculations and trending of parameters. The reactor states are presented through a convenient graphical user interface. (authors)

  9. On-Line Generation of 3D-Waves

    DEFF Research Database (Denmark)

    Frigaard, Peter

    1992-01-01

    The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg.......The paper describes the technique of filtering white noise for on-line generation of 3D-waves on a small computer in the laboratory. The wave generation package is implemented and tested in the 3D-wave basin at the University of Aalborg....

  10. Chromatic-achromatic perimetry in four clinic cases: Glaucoma and diabetes

    Directory of Open Access Journals (Sweden)

    Inmaculada Cabezos

    2015-01-01

    Full Text Available Background: Some diseases that affect the visual system may show loss of chromatic-achromatic sensitivity before obvious physical signs appear in the usual examination of the eye′s posterior segment. A perimetric study has been conducted with four typical patients with glaucoma and diabetes, at different stages of the disease. Materials and Methods: In addition to the standard white-on-white (standard automated perimetry [SAP], a test battery has been used to study patient′s contrast sensitivity, using stimuli with different chromatic, spatial, and temporal content (multichannel perimetry. The choice of stimuli tries to maximize the response of different visual mechanisms: Achromatic (parvocellular and magnocellular origin; chromatic red-green (parvocellular origin; and chromatic blue-yellow (koniocellular origin. Results: The results seem to indicate losses in the achromatic-parvocellular perimetry and both chromatic perimetry tests, undetected by conventional SAP. Conclusions: Our results illustrate that our patients without visible retinal alterations show signs of suspicion in multichannel perimetry.

  11. The main injector chromaticity correction sextupole magnets: Measurements and operating schemes

    International Nuclear Information System (INIS)

    Bhat, C.M.; Bogacz, A.; Brown, B.C.; Harding, D.J.; Fang, S.J.; Martin, P.S.; Glass, H.D.; Sim, J.

    1995-05-01

    The Fermilab Main Injector (FMI) is a high intensity proton synchrotron which will be used to accelerate protons and antiprotons from 8.9 GeV/c to 150 GeV/c. The natural chromaticities of the machine for the horizontal and the vertical Planes are -33.6 and -33.9 respectively. The Δp/p of the beam at injection is about 0.002. The chromaticity requirements of the FMI, are primarily decided by the Δp/p = 0.002 of the beam at injection. This limits the final chromaticity of the FMI to be ±5 units. To correct the chromaticity in the FMI two families of sextupole magnets will be installed in the lattice, one for each plane. A sextupole magnet suitable for the FMI needs has been designed and a number of them are being built. New chromaticity compensation schemes have been worked out in the light of recently proposed faster acceleration ramps. On an R/D sextupole magnet the low current measurements have been carried out to determine the electrical properties. Also, using a Morgan coil, measurements have been performed to determine the higher ordered multipole components up to 18-poles. An overview of these result are presented here

  12. Mixing of Chromatic and Luminance Retinal Signals in Primate Area V1.

    Science.gov (United States)

    Li, Xiaobing; Chen, Yao; Lashgari, Reza; Bereshpolova, Yulia; Swadlow, Harvey A; Lee, Barry B; Alonso, Jose Manuel

    2015-07-01

    Vision emerges from activation of chromatic and achromatic retinal channels whose interaction in visual cortex is still poorly understood. To investigate this interaction, we recorded neuronal activity from retinal ganglion cells and V1 cortical cells in macaques and measured their visual responses to grating stimuli that had either luminance contrast (luminance grating), chromatic contrast (chromatic grating), or a combination of the two (compound grating). As with parvocellular or koniocellular retinal ganglion cells, some V1 cells responded mostly to the chromatic contrast of the compound grating. As with magnocellular retinal ganglion cells, other V1 cells responded mostly to the luminance contrast and generated a frequency-doubled response to equiluminant chromatic gratings. Unlike magnocellular and parvocellular retinal ganglion cells, V1 cells formed a unimodal distribution for luminance/color preference with a 2- to 4-fold bias toward luminance. V1 cells associated with positive local field potentials in deep layers showed the strongest combined responses to color and luminance and, as a population, V1 cells encoded a diverse combination of luminance/color edges that matched edge distributions of natural scenes. Taken together, these results suggest that the primary visual cortex combines magnocellular and parvocellular retinal inputs to increase cortical receptive field diversity and to optimize visual processing of our natural environment. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Localized chromaticity correction of low-beta insertions in storage rings

    International Nuclear Information System (INIS)

    Donald, M.; Helm, R.; Irwin, J.; Moshammer, H.; Sullivan, M.; Forest, E.; Robin, D.; Zholents, A.

    1993-01-01

    The correction of the chromaticity of low-beta insertions in the storage rings is usually made with sextupole lenses in the ring's arcs. When decreasing the beta functions at the insertion point (IP), this technique becomes fairly ineffective, since it fails to properly correct the higher order chromatic aberrations. Here the authors consider the approach where the chromatic effects of the quadrupole lenses generating low beta functions at the IP are corrected locally with two families of sextupoles, one family for each plane. Each family has two pairs of sextupoles which are located symmetrically on both sides of the IP. The sextupole-like aberrations of individual sextupoles are eliminated by utilizing optics forming a -I transformation between sextupoles in the pair. The optics also includes bending magnets which preserve equal dispersion functions at the two sextupoles in each pair. At sextupoles in one family, the vertical beta function is made large and the horizontal is made small. The situation is reversed in the sextupoles of the other family. The betatron phase advances from the IP to the sextupoles are chosen to eliminate a second order chromatic aberration. The application of the localized chromatic correction is demonstrated using as an example the lattice design for the Low Energy Ring of the SLAC/LBL/LLNL PEP-II B Factory

  14. Spectral discrimination in color blind animals via chromatic aberration and pupil shape.

    Science.gov (United States)

    Stubbs, Alexander L; Stubbs, Christopher W

    2016-07-19

    We present a mechanism by which organisms with only a single photoreceptor, which have a monochromatic view of the world, can achieve color discrimination. An off-axis pupil and the principle of chromatic aberration (where different wavelengths come to focus at different distances behind a lens) can combine to provide "color-blind" animals with a way to distinguish colors. As a specific example, we constructed a computer model of the visual system of cephalopods (octopus, squid, and cuttlefish) that have a single unfiltered photoreceptor type. We compute a quantitative image quality budget for this visual system and show how chromatic blurring dominates the visual acuity in these animals in shallow water. We quantitatively show, through numerical simulations, how chromatic aberration can be exploited to obtain spectral information, especially through nonaxial pupils that are characteristic of coleoid cephalopods. We have also assessed the inherent ambiguity between range and color that is a consequence of the chromatic variation of best focus with wavelength. This proposed mechanism is consistent with the extensive suite of visual/behavioral and physiological data that has been obtained from cephalopod studies and offers a possible solution to the apparent paradox of vivid chromatic behaviors in color blind animals. Moreover, this proposed mechanism has potential applicability in organisms with limited photoreceptor complements, such as spiders and dolphins.

  15. Chromatic aberration correction: an enhancement to the calibration of low-cost digital dermoscopes.

    Science.gov (United States)

    Wighton, Paul; Lee, Tim K; Lui, Harvey; McLean, David; Atkins, M Stella

    2011-08-01

    We present a method for calibrating low-cost digital dermoscopes that corrects for color and inconsistent lighting and also corrects for chromatic aberration. Chromatic aberration is a form of radial distortion that often occurs in inexpensive digital dermoscopes and creates red and blue halo-like effects on edges. Being radial in nature, distortions due to chromatic aberration are not constant across the image, but rather vary in both magnitude and direction. As a result, distortions are not only visually distracting but could also mislead automated characterization techniques. Two low-cost dermoscopes, based on different consumer-grade cameras, were tested. Color is corrected by imaging a reference and applying singular value decomposition to determine the transformation required to ensure accurate color reproduction. Lighting is corrected by imaging a uniform surface and creating lighting correction maps. Chromatic aberration is corrected using a second-order radial distortion model. Our results for color and lighting calibration are consistent with previously published results, while distortions due to chromatic aberration can be reduced by 42-47% in the two systems considered. The disadvantages of inexpensive dermoscopy can be quickly substantially mitigated with a suitable calibration procedure. © 2011 John Wiley & Sons A/S.

  16. Localized chromaticity correction of low-beta insertions in storage rings

    International Nuclear Information System (INIS)

    Donald, M.; Helm, R.; Irwin, J.; Moshammer, H.; Sullivan, M.; Forest, E.; Robin, D.; Zholents, A.

    1993-04-01

    The correction of the chromaticity of low-beta insertions in the storage rings is usually made with sextupole lenses in the ring's arcs. When decreasing the beta functions at the insertion point (IP), this technique becomes fairly ineffective, since it fails to properly correct the higher order chromatic aberrations. Here we consider the approach where the chromatic effects of the quadrupole lenses generating low beta functions at the IP are corrected locally with two families of sextupoles, one family for each plane. Each family has two pairs of sextupoles which are located symmetrically on both sides of the IP. The sextupole-like aberrations of individual sextupoles are eliminated by utilizing optics forming a -I transformation between sextupoles in the pair. The optics also includes bending magnets which preserve equal dispersion functions at the two sextupoles in each pair. At sextupoles in one family, the vertical beta function is made large and the horizontal is made small. The situation is reversed in the sextupoles of the other family. The betatron phase advances from the IP to the sextupoles are chosen to eliminate a second order chromatic aberration. The application of the localized chromatic correction is demonstrated using as an example the lattice design for the Low Energy Ring of the SLAC/LBL/LLNL PEP-II B Factory

  17. Optimization Of Chromaticity Compensation And Dynamic Aperture In MEIC Collider Rings

    International Nuclear Information System (INIS)

    Lin, Fanglei; Derbenev, Yaroslav; Morozov, Vasiliy; Zhang, Yuhong; Beard, Kevin

    2012-01-01

    The conceptual design of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab relies on an ultra-small beta-star to achieve high luminosities of up to 10 34 cm -2 s -1 . A low-beta insertion for interaction regions unavoidably induces large chromatic effects that demand a proper compensation. The present approach of chromatic compensation in the MEIC collider rings is based on a local correction scheme using two symmetric chromatic compensation blocks that includes families of sextupoles, and are placed in a beam extension area on both sides of a collision point. It can simultaneously compensate the first order chromaticity and chromatic beam smear at the IP without inducing significant second order aberrations. In this paper, we investigate both the momentum acceptance and dynamic aperture in the MEIC ion collider ring by considering the aberration effects up to the third order, such as amplitude dependent tune shift. We also explore the compensation of the third order effects by introducing families of octupoles in the extended beam area.

  18. Bounds for the b-Chromatic Number of Subgraphs and Edge-Deleted Subgraphs

    Directory of Open Access Journals (Sweden)

    Francis P.

    2016-11-01

    Full Text Available A b-coloring of a graph G with k colors is a proper coloring of G using k colors in which each color class contains a color dominating vertex, that is, a vertex which has a neighbor in each of the other color classes. The largest positive integer k for which G has a b-coloring using k colors is the b-chromatic number b(G of G. In this paper, we obtain bounds for the b- chromatic number of induced subgraphs in terms of the b-chromatic number of the original graph. This turns out to be a generalization of the result due to R. Balakrishnan et al. [Bounds for the b-chromatic number of G−v, Discrete Appl. Math. 161 (2013 1173-1179]. Also we show that for any connected graph G and any e ∈ E(G, b(G - e ≤ b(G + -2. Further, we determine all graphs which attain the upper bound. Finally, we conclude by finding bound for the b-chromatic number of any subgraph.

  19. Second Harmonic Generation, Sum Frequency Generation, and χ(3): Dissecting Environmental Interfaces with a Nonlinear Optical Swiss Army Knife

    Science.gov (United States)

    Geiger, Franz M.

    2009-05-01

    This review discusses recent advances in the nonlinear optics of environmental interfaces. We discuss the quantitative aspects of the label-free approaches presented here and demonstrate that nonlinear optics has now assumed the role of a Swiss Army knife that can be used to dissect, with molecular detail, the fundamental and practical aspects of environmental interfaces and heterogeneous geochemical environments. In this work, nonlinear optical methods are applied to complex organic molecules, such as veterinary antibiotics, and to small inorganic anions and cations, such as nitrate and chromate, or cadmium, zinc, and manganese. The environmental implications of the thermodynamic, kinetic, spectroscopic, structural, and electrochemical data are discussed.

  20. Integrated sensor array for on-line monitoring micro bioreactors

    NARCIS (Netherlands)

    Krommenhoek, E.E.

    2007-01-01

    The “Fed��?batch on a chip��?��?project, which was carried out in close cooperation with the Technical University of Delft, aims to miniaturize and parallelize micro bioreactors suitable for on-line screening of micro-organisms. This thesis describes an electrochemical sensor array which has been

  1. On-Line Pesticide Training with Narrated Powerpoint Presentations

    Science.gov (United States)

    Johnson, Steven B.

    2015-01-01

    UMaine Cooperative Extension is the primary educational delivery organization for pesticide recertification credits in Maine. Shrinking budgets and staff numbers are making traditional face-to-face delivery increasingly difficult to maintain. To address this issue, on-line pesticide applicator recertification training credits were developed. The…

  2. Personality Interactions and Scaffolding in On-Line Discussions

    Science.gov (United States)

    Nussbaum, E. Michael; Hartley, Kendall; Sinatra, Gale M.; Reynolds, Ralph E.; Bendixen, Lisa D.

    2004-01-01

    The potential of on-line discussions to prompt greater reflection of course material is often stymied by a tendency of students to agree with one another rather than to formulate counter-arguments. This article describes an experiment using note starters and elaborated cases to encourage counter-argumentation and examines interactions with…

  3. A new electrostatic on-line collection-system

    International Nuclear Information System (INIS)

    Dufour, J.P.; Del Moral, R.; Fleury, A.; Hubert, F.; Llabador, Y.; Mauhourat, M.B.; Bimbot, R.; Gardes, D.; Rivet, M.F.

    1981-01-01

    The working conditions of a new on-line electrostatic collection system are presented. The main characteristics are high efficiency (reaching 20%) and short delay time (down to the millisecond). The salient features of specific devices for measurements of absolute cross sections, recoil range distributions and angular distributions are given. (orig.)

  4. Specialization processes in on-line unsupervised learning

    NARCIS (Netherlands)

    Biehl, M.; Freking, A.; Reents, G.; Schlösser, E.

    1998-01-01

    From the recent analysis of supervised learning by on-line gradient descent in multilayered neural networks it is known that the necessary process of student specialization can be delayed significantly. We demonstrate that this phenomenon also occurs in various models of unsupervised learning. A

  5. A simulation of the SDC on-line processing farm

    International Nuclear Information System (INIS)

    Wang, C.; Chen, Y.; Dorenbosch, J.; Lee, J.; Sayle, R.

    1993-10-01

    In the Solenoidal Detector Collaboration (SDC) data acquisition system (DAQ), an enormous amount of data flows into a processor farm for extraction of interesting physics events. To design an efficient on-line filter, the operations in the farm must be carefully modeled. The authors present a simulation model developed at the Superconducting Super Collider Laboratory which efficiently allocates physics events to the farm

  6. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  7. An optimal algorithm for preemptive on-line scheduling

    NARCIS (Netherlands)

    Chen, B.; Vliet, van A.; Woeginger, G.J.

    1995-01-01

    We investigate the problem of on-line scheduling jobs on m identical parallel machines where preemption is allowed. The goal is to minimize the makespan. We derive an approximation algorithm with worst-case guarantee mm/(mm - (m - 1)m) for every m 2, which increasingly tends to e/(e - 1) ˜ 1.58 as m

  8. Comparison between constant methanol feed and on-line ...

    African Journals Online (AJOL)

    Two methanol feeding methods, namely constant methanol feed and on-line monitoring feed control by methanol sensor were investigated to improve the production of recombinant human growth hormone (rhGH) in high cell density cultivation of Pichia pastoris KM71 in 2 L bioreactor. The yeast utilized glycerol as a carbon ...

  9. Children's On-Line Processing of Scrambling in Japanese

    Science.gov (United States)

    Suzuki, Takaaki

    2013-01-01

    This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in…

  10. AAEC INIS - a large, new, on-line information source

    International Nuclear Information System (INIS)

    Rugg, T.J.; Wong, S.C.

    1984-01-01

    The Australian Atomic Energy Commission's INIS database is available for on-line searching by non-AAEC personnel from all parts of Australia. An introduction to the International Nuclear Information System is followed by information on searching AAEC INIS, AAEC INIS retrieval software and accessing AAEC INIS

  11. ORION-the Omega Remote Interactive On-line System

    CERN Document Server

    Russell, R D; Levratt, B; Lipps, H; Sparrman, P

    1974-01-01

    ORION is a system which permits the manipulation of files, records and characters, remote job submittal and retrieval of output files including the direct loading of remote on-line computers. The system uses the computer hardware of the OMEGA project at CERN and is designed to assist researchers in development and debugging of their programs. (10 refs).

  12. ORION - the OMEGA Remote Interactive On-line System

    CERN Document Server

    Russell, R D; Krieger, M

    1973-01-01

    ORION is a system which permits the manipulation of files, records and characters, remote job submittal and retrieval of output files including the direct loading of remote on-line computers. The system uses the computer hardware of the OMEGA project at CERN, and is designed to assist researchers in development and debugging of their programs.

  13. Booth Library On-Line Circulation System (BLOC

    Directory of Open Access Journals (Sweden)

    Paladugu V. Rao

    1971-06-01

    Full Text Available An on-line circulation system developed at a relatively small university library demonstrates that academic libraries with limited funds can develop automated systems utilizing parent institution's computer facilities in a time-sharing mode. In operation since September 1968, using an IBM 360/50 computer and associated peripheral equipment, it provides control over all stack books.

  14. On-line learning from clustered input examples

    NARCIS (Netherlands)

    Riegler, Peter; Biehl, Michael; Solla, Sara A.; Marangi, Carmela; Marinaro, Maria; Tagliaferri, Roberto

    1996-01-01

    We analyse on-line learning of a linearly separable rule with a simple perceptron. Example inputs are taken from two overlapping clusters of data and the rule is defined through a teacher vector which is in general not aligned with the connection line of the cluster centers. We find that the Hebb

  15. Investigating on-line pornography at the University of Johannesburg

    Directory of Open Access Journals (Sweden)

    P. Laughton

    2008-01-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with a total of 49,4% male participants and 50,6% female, with the largest grouping of respondents (61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  16. On-line sample treatment - Capillary gas chromatography

    NARCIS (Netherlands)

    Goosens, EC; de Jong, D; de Jong, GJ; Brinkman, UAT

    Sample pretreatment is often the bottleneck of a trace level analytical procedure. In order to increase performance, increasing attention is therefore being devoted to combining sample pretreatment on-line with the separation technique that has to be used. In the present review, a variety of

  17. A new electrostatic on-line collection-system

    International Nuclear Information System (INIS)

    Dufour, J.P.; Del Moral, R.; Fleury, A.

    1981-06-01

    The working conditions of a new on-line electrostatic collection system are presented. The main charactersitics are high efficiency (reaching 20%) and short delay time (down to the millisecond). The salient features of specific devices for measurements of absolute cross sections, recoil range distributions and angular distributions are given

  18. Summary remarks and prospects for on-line nuclear orientation

    International Nuclear Information System (INIS)

    Krane, K.S.; Hamilton, J.H.

    1984-01-01

    This paper reviews the use of on-line nuclear orientations as a method for determining hyperfine structure. Historical developments and future prospects for the technique are presented. The role that this technique can play in nuclear spectroscopy and the study of nuclei far from the beta stability are outlined

  19. WMI2, the Student's On-Line Symbolic Calculator

    Science.gov (United States)

    Kovacs, Zoltan

    2011-01-01

    Student activities focused on discovering mathematics play an important role in the teaching and learning process. WebMathematics Interactive (WMI2) was developed to offer a fast and user-friendly on-line web interface to enhance the quality of both theoretical and applied mathematics courses. For the teacher, in the classroom, it provides…

  20. ADAPTIVE CONTEXT PROCESSING IN ON-LINE HANDWRITTEN CHARACTER RECOGNITION

    NARCIS (Netherlands)

    Iwayama, N.; Ishigaki, K.

    2004-01-01

    We propose a new approach to context processing in on-line handwritten character recognition (OLCR). Based on the observation that writers often repeat the strings that they input, we take the approach of adaptive context processing. (ACP). In ACP, the strings input by a writer are automatically

  1. Microcomputers as on-line catalogs in special libraries.

    Science.gov (United States)

    Faust, J B

    1986-01-01

    This article discusses the rationale for the conversion of a card catalog to an on-line system in a special library owning approximately 4000 titles. Equipment, software, and procedures are described. Pros and cons of the use of a microcomputer for such a project, as well as costs and personnel needs, are outlined.

  2. Efficient and secure comparison for on-line auctions

    NARCIS (Netherlands)

    Damgard, Ivan; Geisler, M.; Kroigaard, M.; Pieprzyk, J.; Ghodosi, H.; Dawson, E.

    2007-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both with

  3. The on-line asymmetric traveling salesman problem

    NARCIS (Netherlands)

    Ausiello, G.; Bonifaci, V.; Laura, L.

    2008-01-01

    We consider two on-line versions of the asymmetric traveling salesman problem with triangle inequality. For the homing version, in which the salesman is required to return in the city where it started from, we give a -competitive algorithm and prove that this is best possible. For the nomadic

  4. Facing regulatory challenges of on-line hemodiafiltration.

    Science.gov (United States)

    Kümmerle, Wolfgang

    2011-01-01

    On-line hemodiafiltration (on-line HDF) is the result of a vision that triggered multifarious changes in very different areas. Driven by the idea to offer better medical treatment for renal patients, technological innovations were developed and established that also constituted new challenges in the field of regulatory affairs. The existing regulations predominantly addressed the quality and safety of those products needed to perform dialysis treatment which were supplied by industrial manufacturers. However, the complexity of treatment system required for the provision of on-line fluids demanded a holistic approach encompassing all components involved. Hence, focus was placed not only on single products, but much more on their interfacing, and the clinical infrastructure, in particular, had to undergo substantial changes. The overall understanding of the interaction between such factors, quite different in their nature, was crucial to overcome the arising regulatory obstacles. This essay describes the evolution of the on-line HDF procedure from the regulatory point of view. A simplified diagram demonstrates the path taken from the former regulatory understanding to the realization of necessary changes. That achievement was only possible through 'management of preview' and consequent promotion of technical and medical innovations as well as regulatory re-evaluations. Copyright © 2011 S. Karger AG, Basel.

  5. Project development and commercialization of on-line analysis systems

    International Nuclear Information System (INIS)

    Watt, J.S.

    1997-01-01

    A project team first in the Australian Atomic Energy Commission (AAEC) and since 1982 in CSIRO has developed many on-line analysis systems for the mineral and energy industries. The development of these projects has followed a common pattern of laboratory R and D, field trials, commercialisation and technology transfer. This successful pattern is illustrated using examples of the development of systems for the on-line analysis of mineral slurries, for determination of the ash content of coal on conveyors, and for determination of the flow rates of oil, water and gas in pipelines. The first two systems are licensed to Australian companies, Amdel Ltd and Mineral Control Instrumentation Ltd. Both systems are used by industry worldwide, and are the market leaders for radioisotope gauges in their application field. The third system, the multiphase flow meter, was licensed in 1997 to Kvaerner FSSL Ltd of Aberdeen. This meter has even greater potential than the other two systems for economic benefit from its used and for numbers of installations. The on-line analysis systems have been developed to increase the productivity of the Australian mineral and energy industries, and to provide economic benefit to Australia. The economic benefit sought is predominantly improved process control based on use of the instrument, rather than from its sale. Sales of instruments are significant, however, with about A$80 million from the analysis systems and their derivatives since the 1970s. Some of the issues associated with the development of the on-line analysis system are outlined

  6. Chromate adsorption mechanism on nanodiamond-derived onion-like carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Young-Jin [Center for Electronic Materials, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Choi, Keunsu [Computational Science Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Lee, Soonjae [Department of Earth and Environmental Sciences, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea (Korea, Republic of); Cho, Jung-Min [Center for Electronic Materials, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul 120-749, Republic of Korea (Korea, Republic of); Choi, Heon-Jin [Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul 120-749, Republic of Korea (Korea, Republic of); Hong, Seok Won [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Choi, Jae-Woo, E-mail: plead36@kist.re.kr [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Department of Energy and Environmental Engineering, University of Science and Technology (UST), Daejeon 305-350, Republic of Korea (Korea, Republic of); Mizuseki, Hiroshi, E-mail: mizuseki@kist.re.kr [Computational Science Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of); Lee, Wook-Seong, E-mail: wsleemk@gmail.com [Center for Electronic Materials, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea (Korea, Republic of)

    2016-12-15

    The onion-like carbon (OLC) was prepared as adsorbent and tested for the removal of chromate ions from aqueous solutions. The OLC was thermally derived from nanodiamond by vacuum annealing at 1000-2000 °C. An investigation was conducted the chromate adsorption mechanism of OLC, by analysing the temperature-dependent evolution of the various oxygen-carbon bonds and the chemisorbed water by X-ray photo electron spectroscopy, as well as by the first principle calculation of the bond energies for relevant bond configurations. The present work demonstrated the importance of the carbon-oxygen bond type and carbon dangling bonds for chromate adsorption, as well as for other anionic heavy metals adsorbed from wastewater and sewage.

  7. Measurement of chromatic dispersion of microstructured polymer fibers by white-light spectral interferometry

    DEFF Research Database (Denmark)

    Hlubina, Petr; Ciprian, Dalibor; Frosz, Michael Henoch

    2009-01-01

    We present a white-light spectral interferometric method for measuring the chromatic dispersion of microstructured fibers made of polymethyl methacrylate (PMMA). The method uses an unbalanced Mach-Zehnder interferometer with the fiber of known length placed in one of the interferometer arms...... of the method by measuring the wavelength dependence of the differential group refractive index of a pure silica fiber. We apply a five-term power series fit to the measured data and confirm by its differentiation that the chromatic dispersion of pure silica glass agrees well with theory. Second, we measure...... the chromatic dispersion for the fundamental mode supported by two different PMMA microstructured fibers, the multimode fiber and the large-mode area one....

  8. Contradictory effect of chromate inhibitor on corrosive wear of aluminium alloy

    International Nuclear Information System (INIS)

    Pokhmurskii, V.I.; Zin, I.M.; Vynar, V.A.; Bily, L.M.

    2011-01-01

    Research highlights: → Corrosive wear of aluminium alloy in inhibited artificial acid rain was studied. → Tribometer with linear reciprocating ball-on-flat geometry was used.→ Corrosion potential, polarization current and friction coefficient were measured. → Chromate decreases corrosion of aluminium alloy under wear conditions. → Chromate in general accelerates corrosive wear of the alloy in acid rain. - Abstract: The corrosive wear of D16T aluminium alloy in artificial acid rain was studied. A special tribometer with the linear reciprocating ball-on-flat geometry was used. The setup allows to measure simultaneously an open circuit potential, to carry out potentiostatic and potentiodynamic polarization studies of the alloy corrosion and to record the friction coefficient. It was established that the addition of strontium chromate inhibitor to the working environment decreases an electrochemical corrosion of the aluminium alloy under wear conditions, but in general accelerates its destruction due to insufficient wear resistance of a formed surface film.

  9. Tune and Chromaticity Control During Snapback and Ramp in 2015 LHC Operation

    CERN Document Server

    Schaumann, Michaela; Lamont, Mike; Solfaroli Camillocci, Matteo; Todesco, Ezio; Wenninger, Jorg

    2016-01-01

    Because of current redistribution on the superconducting cables, the harmonic components of the magnetic fields of the superconducting magnets in the Large Hadron Collider (LHC) show decay during the low field injection plateau. This results in tune and chromaticity variations for the beams. In the first few seconds of the ramp the original hysteresis state of the magnetic field is restored - the field snaps back. These fast dynamic field changes lead to strong tune and chromaticity excursions that, if not properly controlled, induce beam losses and potentially trigger a beam dump. A feed-forward system applies predicted corrections during the injection plateau and to the first part of the ramp to avoid violent changes of beam conditions. This paper discusses the snapback of tune and chromaticity as observed in 2015, as well as the control of beam parameters during the ramp. It also evaluates the quality of the applied feed-forward corrections and their reproducibility.

  10. Chromatic-free spatially resolved optical emission spectroscopy diagnostics for microplasma

    International Nuclear Information System (INIS)

    Zhu Liguo; Chen Wencong; Zhu Ximing; Pu Yikang; Li Zeren

    2009-01-01

    A chromatic-free spatially resolved diagnostic system for microplasma measurement is proposed and demonstrated, which consists of an optical chromatic-free microscope mirror system, an electron multiplying charge coupled device (EMCCD), and bandpass filters. The diagnostic system free of chromatic aberrations with a spatial resolution of about 6 μm is achieved. The factors that limit the resolution of this diagnostic system have been analyzed, which are optical diffraction, the pixel size of the EMCCD, and the thickness of the microplasma. In this paper, the optimal condition for achieving a maximum resolution power has been analyzed. With this diagnostic system, we revealed the spatial nonuniformity of a microwave atmospheric-pressure argon microplasma. Furthermore, the spatial distribution of the time-averaged effective electron temperature has been estimated from the intensity distributions of 750.4 and 415.8 nm emissions.

  11. Amino-functionalized MCM-41 and MCM-48 for the removal of chromate and arsenate.

    Science.gov (United States)

    Benhamou, A; Basly, J P; Baudu, M; Derriche, Z; Hamacha, R

    2013-08-15

    The aim of the present work was to investigate the efficiency of three amino-functionalized (hexadecylamine, dodecylamine, and dimethyldodecylamine) mesoporous silicas (MCM-41 and MCM-48) toward the adsorption of arsenate and chromate. Hexadecylamine-functionalized materials were characterized; BET surface areas, pore volumes, and sizes decreased with the functionalization, whereas XRD patterns show that the hexagonal structure of MCM-41 and the cubic structure of MCM-48 were not modified. The zeta potential decreases with pH and the highest arsenate and chromate removal was observed at the lowest pHs. Adsorption of chromium and arsenate was significantly enhanced after functionalization and amino-functionalized MCM-41 adsorb larger amounts of arsenate when compared to expanded MCM-48 materials. Chromate sorption capacities increased with the chain length and the larger capacities were obtained with hexadecylamine-functionalized mesoporous silicas. Mesoporous silicas modified by dimethyldodecylamine exhibited the higher arsenate sorption capacities. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Determination of aluminium and beryllium by diffuse reflectance spectrometry with the use of chromaticity functions

    International Nuclear Information System (INIS)

    Ivanov, V.M.; Ershova, N.I.

    2001-01-01

    Immobilized Eriochrome Cyanine R was used for the direct trace determination of aluminium and beryllium by diffuse reflectance spectrometry. Anion exchanger AV-17, silica gel Silochrom C-120, Chromaton N-Super, silica gel C 18 , and cellulose were examined as supports. Optimal sorption conditions were found. The dependence of chromaticity functions (chromaticity coordinates, lightness, color saturation, yellowness, and whiteness) on different factors was studied. Advantages of the use of chromaticity functions rather than the diffuse reflectance coefficient were demonstrated. A method is developed for the separate determination of aluminium and beryllium using cellulose as the support; the method was used for the analysis of real samples and tested with standard samples. When solution samples of 50 and 100 ml were used, the determination limit was 0.004 μg/ml for aluminium and 0.0002 μg/ml for beryllium, respectively [ru

  13. Obstructions to the realization of distance graphs with large chromatic numbers on spheres of small radii

    Energy Technology Data Exchange (ETDEWEB)

    Kupavskii, A B; Raigorodskii, A M [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

    2013-10-31

    We investigate in detail some properties of distance graphs constructed on the integer lattice. Such graphs find wide applications in problems of combinatorial geometry, in particular, such graphs were employed to answer Borsuk's question in the negative and to obtain exponential estimates for the chromatic number of the space. This work is devoted to the study of the number of cliques and the chromatic number of such graphs under certain conditions. Constructions of sequences of distance graphs are given, in which the graphs have unit length edges and contain a large number of triangles that lie on a sphere of radius 1/√3 (which is the minimum possible). At the same time, the chromatic numbers of the graphs depend exponentially on their dimension. The results of this work strengthen and generalize some of the results obtained in a series of papers devoted to related issues. Bibliography: 29 titles.

  14. Nonlinear Elliptic Differential Equations with Multivalued Nonlinearities

    Indian Academy of Sciences (India)

    In this paper we study nonlinear elliptic boundary value problems with monotone and nonmonotone multivalued nonlinearities. First we consider the case of monotone nonlinearities. In the first result we assume that the multivalued nonlinearity is defined on all R R . Assuming the existence of an upper and of a lower ...

  15. Adaptive on-line prediction of the available power of lithium-ion batteries

    Science.gov (United States)

    Waag, Wladislaw; Fleischer, Christian; Sauer, Dirk Uwe

    2013-11-01

    In this paper a new approach for prediction of the available power of a lithium-ion battery pack is presented. It is based on a nonlinear battery model that includes current dependency of the battery resistance. It results in an accurate power prediction not only at room temperature, but also at lower temperatures at which the current dependency is substantial. The used model parameters are fully adaptable on-line to the given state of the battery (state of charge, state of health, temperature). This on-line adaption in combination with an explicit consideration of differences between characteristics of individual cells in a battery pack ensures an accurate power prediction under all possible conditions. The proposed trade-off between the number of used cell parameters and the total accuracy as well as the optimized algorithm results in a real-time capability of the method, which is demonstrated on a low-cost 16 bit microcontroller. The verification tests performed on a software-in-the-loop test bench system with four 40 Ah lithium-ion cells show promising results.

  16. An adaptive observer for on-line tool wear estimation in turning, Part I: Theory

    Science.gov (United States)

    Danai, Kourosh; Ulsoy, A. Galip

    1987-04-01

    On-line sensing of tool wear has been a long-standing goal of the manufacturing engineering community. In the absence of any reliable on-line tool wear sensors, a new model-based approach for tool wear estimation has been proposed. This approach is an adaptive observer, based on force measurement, which uses both parameter and state estimation techniques. The design of the adaptive observer is based upon a dynamic state model of tool wear in turning. This paper (Part I) presents the model, and explains its use as the basis for the adaptive observer design. This model uses flank wear and crater wear as state variables, feed as the input, and the cutting force as the output. The suitability of the model as the basis for adaptive observation is also verified. The implementation of the adaptive observer requires the design of a state observer and a parameter estimator. To obtain the model parameters for tuning the adaptive observer procedures for linearisation of the non-linear model are specified. The implementation of the adaptive observer in turning and experimental results are presented in a companion paper (Part II).

  17. Virtual sensors for on-line wheel wear and part roughness measurement in the grinding process.

    Science.gov (United States)

    Arriandiaga, Ander; Portillo, Eva; Sánchez, Jose A; Cabanes, Itziar; Pombo, Iñigo

    2014-05-19

    Grinding is an advanced machining process for the manufacturing of valuable complex and accurate parts for high added value sectors such as aerospace, wind generation, etc. Due to the extremely severe conditions inside grinding machines, critical process variables such as part surface finish or grinding wheel wear cannot be easily and cheaply measured on-line. In this paper a virtual sensor for on-line monitoring of those variables is presented. The sensor is based on the modelling ability of Artificial Neural Networks (ANNs) for stochastic and non-linear processes such as grinding; the selected architecture is the Layer-Recurrent neural network. The sensor makes use of the relation between the variables to be measured and power consumption in the wheel spindle, which can be easily measured. A sensor calibration methodology is presented, and the levels of error that can be expected are discussed. Validation of the new sensor is carried out by comparing the sensor's results with actual measurements carried out in an industrial grinding machine. Results show excellent estimation performance for both wheel wear and surface roughness. In the case of wheel wear, the absolute error is within the range of microns (average value 32 μm). In the case of surface finish, the absolute error is well below Ra 1 μm (average value 0.32 μm). The present approach can be easily generalized to other grinding operations.

  18. IOOS Data Portals and Uniform On-line Browse Capabilities

    Science.gov (United States)

    Howard, M.; Currier, R. D.; Kobara, S.; Gayanilo, F.

    2015-12-01

    The Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA) is one of eleven Regional Associations organized under the NOAA-led U.S. Integrated Ocean Observing System (IOOS) Program Office. Each of the RAs operate standards-based regional data portals designed to aggregate near real-time and historical observed data and modeled outputs from distributed providers and to offer these and derived products in standardized ways to a diverse set of users. The RA's portals are based on the IOOS Data and Communications Plan which describes the functional elements needed for an interoperable system. One of these elements is called "Uniform On-line Browse" which is an informational service designed primarily to visualize the inventory of a portal. An on-line browse service supports the end user's need to discover what parameters are available, to learn the spatial and temporal extend of the holdings, and to examine the character of the data (e.g, variability, gappiness, etc). These pieces of information help the end user decide if the data are fit for his/her purpose and to construct valid data requests. Note that on-line browse is a distinctly different activity than data analysis because it seeks to yield knowledge about the inventory and not about what the data mean. "Uniform" on-line browse is a service that takes advantage of the standardization of the data portal's data access points. Most portals represent station locations on a map. This is a view of the data inventory but these plots are rarely generated by pulling data through the standards-based services offered to the end users but through methods only available to the portal programmers. This work will present results of Uniform On-line browse tools developed within GCOOS-RA and their applicability to other RA portals.

  19. Mentoring Narratives ON-LINE:Teaching the Principalship

    Directory of Open Access Journals (Sweden)

    Allison I. Griffith

    2002-05-01

    Full Text Available The need to develop new models for preparation of school administrators has been a prominent concern in educational discourse in the last decade. Having been criticized for the inadequate preparation of the school leadership cadre, academic departments responsible for training future school administrators have had to revisit their approaches and to reframe their teaching philosophies to ensure the readiness of their graduates for the challenges and complexities of school leadership. This article reports on the new model of principals' training that has been used in York University's Principals' Qualification Program (PQP from the late 1990s onward. One component of the program brings traditional case methodology into a computer-mediated/on-line environment. The on-line cases are narratives from the everyday lives of the Ontario school administrators who serve as mentors in the on-line environment. Situating our discussion within the context of the rapidly changing educational landscape of Ontario, we focus on the PQP model to explore experientially generated case narratives as one method for teaching and learning the work of the local school administrator. We focus particularly on the teaching and learning embedded in computer-mediated or on-line case narratives used in training teachers for school leadership. We argue that the complexities of school leadership—the social, cultural, relational, ethical and moral context of school leadership—can be taught effectively through the reflective processes of on-line case narratives. We seek to contribute to the ongoing dialogue on the potential of new pedagogies and new technologies to help prepare the competent and responsible leaders for tomorrow's schools.

  20. [Chromaticity and optical spectrum colorimetry of the tongue color in different syndromes of primary hepatic carcinoma].

    Science.gov (United States)

    Xu, Ying; Zeng, Chang-chun; Cai, Xiu-yu; Guo, Rong-ping; Nie, Guang; Jin, Ying

    2012-11-01

    In this study, the optical data of tongue color of different syndromes in primary hepatic carcinoma (PHC) were detected by optical spectrum colorimetry, and the chromaticity of tongue color was compared and analyzed. The tongue color characteristics of different syndromes in PHC and the relationship between different syndromes and tongue color were also investigated. Tongue color data from 133 eligible PHC patients were collected by optical spectrum colorimetry and the patients were divided into 4 syndrome groups according to their clinical features. The syndrome groups were liver depression and spleen deficiency (LDSD), accumulation of damp-heat (ADH), deficiency of liver and kidney yin (DLKY), and qi stagnation and blood stasis (QSBS). The variation characteristics of chromaticity coordinates, dominant wavelength, excitation purity and the distribution in the International Commission on Illumination (CIE) LAB uniform color space were measured. At the same time, the differences of overall chromatism, clarity, chroma, saturation and hue were also calculated and analyzed. PHC patients in different syndrome groups exhibited differences in chromaticity coordinates. The dominant wavelength of QSBS was distinctly different from that of the other 3 syndromes. Excitation purity in the syndromes of LDSD, ADH and DLKY showed gradual increases (Pcolorimetry technology. Different syndromes in PHC exhibit distinct chromatisms of tongue color through the calculation and analysis of chromaticity parameters of CIE, combined with colorimetric system and CIE LAB color space, and these are consistent with the characteristics of clinical tongue color. Applying optical spectrum colorimetry technology to tongue color differentiation has the potential to serve as a reference point in standardizing traditional Chinese medicine syndrome classification in PHC.

  1. Chromatic signals control proboscis movements during hovering flight in the hummingbird hawkmoth Macroglossum stellatarum.

    Science.gov (United States)

    Goyret, Joaquín; Kelber, Almut

    2012-01-01

    Most visual systems are more sensitive to luminance than to colour signals. Animals resolve finer spatial detail and temporal changes through achromatic signals than through chromatic ones. Probably, this explains that detection of small, distant, or moving objects is typically mediated through achromatic signals. Macroglossum stellatarum are fast flying nectarivorous hawkmoths that inspect flowers with their long proboscis while hovering. They can visually control this behaviour using floral markings known as nectar guides. Here, we investigate whether this is mediated by chromatic or achromatic cues. We evaluated proboscis placement, foraging efficiency, and inspection learning of naïve moths foraging on flower models with coloured markings that offered either chromatic, achromatic or both contrasts. Hummingbird hawkmoths could use either achromatic or chromatic signals to inspect models while hovering. We identified three, apparently independent, components controlling proboscis placement: After initial contact, 1) moths directed their probing towards the yellow colour irrespectively of luminance signals, suggesting a dominant role of chromatic signals; and 2) moths tended to probe mainly on the brighter areas of models that offered only achromatic signals. 3) During the establishment of the first contact, naïve moths showed a tendency to direct their proboscis towards the small floral marks independent of their colour or luminance. Moths learned to find nectar faster, but their foraging efficiency depended on the flower model they foraged on. Our results imply that M. stellatarum can perceive small patterns through colour vision. We discuss how the different informational contents of chromatic and luminance signals can be significant for the control of flower inspection, and visually guided behaviours in general.

  2. Structure determination and functional analysis of a chromate reductase from Gluconacetobacter hansenii.

    Directory of Open Access Journals (Sweden)

    Hongjun Jin

    Full Text Available Environmental protection through biological mechanisms that aid in the reductive immobilization of toxic metals (e.g., chromate and uranyl has been identified to involve specific NADH-dependent flavoproteins that promote cell viability. To understand the enzyme mechanisms responsible for metal reduction, the enzyme kinetics of a putative chromate reductase from Gluconacetobacter hansenii (Gh-ChrR was measured and the crystal structure of the protein determined at 2.25 Å resolution. Gh-ChrR catalyzes the NADH-dependent reduction of chromate, ferricyanide, and uranyl anions under aerobic conditions. Kinetic measurements indicate that NADH acts as a substrate inhibitor; catalysis requires chromate binding prior to NADH association. The crystal structure of Gh-ChrR shows the protein is a homotetramer with one bound flavin mononucleotide (FMN per subunit. A bound anion is visualized proximal to the FMN at the interface between adjacent subunits within a cationic pocket, which is positioned at an optimal distance for hydride transfer. Site-directed substitutions of residues proposed to involve in both NADH and metal anion binding (N85A or R101A result in 90-95% reductions in enzyme efficiencies for NADH-dependent chromate reduction. In comparison site-directed substitution of a residue (S118A participating in the coordination of FMN in the active site results in only modest (50% reductions in catalytic efficiencies, consistent with the presence of a multitude of side chains that position the FMN in the active site. The proposed proximity relationships between metal anion binding site and enzyme cofactors is discussed in terms of rational design principles for the use of enzymes in chromate and uranyl bioremediation.

  3. Accelerated redox reaction between chromate and phenolic pollutants during freezing

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Jinjung; Kim, Jaesung [Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon, Gangwon-do 24252 (Korea, Republic of); Vetráková, Ľubica [Department of Chemistry and Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Seo, Jiwon [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919 (Korea, Republic of); Heger, Dominik [Department of Chemistry and Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Lee, Changha [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919 (Korea, Republic of); Yoon, Ho-Il [Korea Polar Research Institute (KOPRI), Incheon 21990 (Korea, Republic of); Kim, Kitae, E-mail: ktkim@kopri.re.kr [Korea Polar Research Institute (KOPRI), Incheon 21990 (Korea, Republic of); Kim, Jungwon, E-mail: jwk@hallym.ac.kr [Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon, Gangwon-do 24252 (Korea, Republic of)

    2017-05-05

    Highlights: • Redox conversion of 4-CP/Cr(VI) was significantly accelerated during freezing. • Accelerated redox conversion in ice is ascribed to the freeze concentration effect. • 4-CP, Cr(VI), and protons are concentrated in the liquid brine by freezing. • Redox conversions of various phenolic pollutants/Cr(VI) were significant in ice. • Freezing-accelerated redox conversion was observed in real polluted water. - Abstract: The redox reaction between 4-chlorophenol (4-CP) and chromate (Cr(VI)) (i.e., the simultaneous oxidation of 4-CP by Cr(VI) and reduction of Cr(VI) by 4-CP) in ice (i.e., at −20 °C) was compared with the corresponding reaction in water (i.e., at 25 °C). The redox conversion of 4-CP/Cr(VI), which was negligible in water, was significantly accelerated in ice. This accelerated redox conversion of 4-CP/Cr(VI) in ice is ascribed to the freeze concentration effect occurring during freezing, which excludes solutes (i.e., 4-CP and Cr(VI)) and protons from the ice crystals and subsequently concentrates them in the liquid brine. The concentrations of Cr(VI) and protons in the liquid brine were confirmed by measuring the optical image and the UV–vis absorption spectra of cresol red (CR) as a pH indicator of frozen solution. The redox conversion of 4-CP/Cr(VI) was observed in water when the concentrations of 4-CP/protons or Cr(VI)/protons increased by 100/1000-fold. These results corroborate the freeze concentration effect as the reason for the accelerated redox conversion of 4-CP/Cr(VI) in ice. The redox conversion of various phenolic pollutants/Cr(VI) and 4-CP/Cr(VI) in real wastewater was successfully achieved in ice, which verifies the environmental relevance and importance of freezing-accelerated redox conversion of phenolic pollutants/Cr(VI) in cold regions.

  4. Cardinal and anti-cardinal points, equalities and chromatic dependence.

    Science.gov (United States)

    Evans, Tanya; Harris, William F

    2017-05-01

    Cardinal points are used for ray tracing through Gaussian systems. Anti-principal and anti-nodal points (which we shall refer to as the anti-cardinal points), along with the six familiar cardinal points, belong to a much larger set of special points. The purpose of this paper is to obtain a set of relationships and resulting equalities among the cardinal and anti-cardinal points and to illustrate them using Pascal's ring. The methodology used relies on Gaussian optics and the transference T. We make use of two equations, obtained via the transference, which give the locations of the six cardinal and four anti-cardinal points with respect to the system. We obtain equalities among the cardinal and anti-cardinal points. We utilise Pascal's ring to illustrate which points depend on frequency and their displacement with change in frequency. Pascal described a memory schema in the shape of a hexagon for remembering equalities among the points and illustrating shifts in these points when an aspect of the system changes. We modify and extend Pascal's ring to include the anti-cardinal points. We make use of Pascal's ring extended to illustrate which points are dependent on the frequency of light and the direction of shift of the equalities with change in frequency. For the reduced eye the principal and nodal points are independent of frequency, but the focal points and the anti-cardinal points depend on frequency. For Le Grand's four-surface model eye all six cardinal and four anti-cardinal points depend on frequency. This has implications for definitions, particularly of chromatic aberrations of the eye, that make use of cardinal points and that themselves depend on frequency. Pascal's ring and Pascal's ring extended are novel memory schema for remembering the equalities among the cardinal and anti-cardinal points. The rings are useful for illustrating changes among the equalities and direction of shift of points when an aspect of a system changes. Care should be taken

  5. Accelerated redox reaction between chromate and phenolic pollutants during freezing

    International Nuclear Information System (INIS)

    Ju, Jinjung; Kim, Jaesung; Vetráková, Ľubica; Seo, Jiwon; Heger, Dominik; Lee, Changha; Yoon, Ho-Il; Kim, Kitae; Kim, Jungwon

    2017-01-01

    Highlights: • Redox conversion of 4-CP/Cr(VI) was significantly accelerated during freezing. • Accelerated redox conversion in ice is ascribed to the freeze concentration effect. • 4-CP, Cr(VI), and protons are concentrated in the liquid brine by freezing. • Redox conversions of various phenolic pollutants/Cr(VI) were significant in ice. • Freezing-accelerated redox conversion was observed in real polluted water. - Abstract: The redox reaction between 4-chlorophenol (4-CP) and chromate (Cr(VI)) (i.e., the simultaneous oxidation of 4-CP by Cr(VI) and reduction of Cr(VI) by 4-CP) in ice (i.e., at −20 °C) was compared with the corresponding reaction in water (i.e., at 25 °C). The redox conversion of 4-CP/Cr(VI), which was negligible in water, was significantly accelerated in ice. This accelerated redox conversion of 4-CP/Cr(VI) in ice is ascribed to the freeze concentration effect occurring during freezing, which excludes solutes (i.e., 4-CP and Cr(VI)) and protons from the ice crystals and subsequently concentrates them in the liquid brine. The concentrations of Cr(VI) and protons in the liquid brine were confirmed by measuring the optical image and the UV–vis absorption spectra of cresol red (CR) as a pH indicator of frozen solution. The redox conversion of 4-CP/Cr(VI) was observed in water when the concentrations of 4-CP/protons or Cr(VI)/protons increased by 100/1000-fold. These results corroborate the freeze concentration effect as the reason for the accelerated redox conversion of 4-CP/Cr(VI) in ice. The redox conversion of various phenolic pollutants/Cr(VI) and 4-CP/Cr(VI) in real wastewater was successfully achieved in ice, which verifies the environmental relevance and importance of freezing-accelerated redox conversion of phenolic pollutants/Cr(VI) in cold regions.

  6. UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology.

    Science.gov (United States)

    Wang, Xiaohua; Li, Xi; Rong, Mingzhe; Xie, Dingli; Ding, Dan; Wang, Zhixiang

    2017-01-18

    The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space ( H , L , and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved.

  7. Methods and optical fibers that decrease pulse degradation resulting from random chromatic dispersion

    Science.gov (United States)

    Chertkov, Michael; Gabitov, Ildar

    2004-03-02

    The present invention provides methods and optical fibers for periodically pinning an actual (random) accumulated chromatic dispersion of an optical fiber to a predicted accumulated dispersion of the fiber through relatively simple modifications of fiber-optic manufacturing methods or retrofitting of existing fibers. If the pinning occurs with sufficient frequency (at a distance less than or are equal to a correlation scale), pulse degradation resulting from random chromatic dispersion is minimized. Alternatively, pinning may occur quasi-periodically, i.e., the pinning distance is distributed between approximately zero and approximately two to three times the correlation scale.

  8. On the chromatic number of triangle-free graphs of large minimum degree

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2002-01-01

    We prove that, for each. fixed real number c > 1/3, the triangle-free graphs of minimum degree at least cn (where n is the number of vertices) have bounded chromatic number. This problem was raised by Erdos and Simonovits in 1973 who pointed out that there is no such result for c <1/3.......We prove that, for each. fixed real number c > 1/3, the triangle-free graphs of minimum degree at least cn (where n is the number of vertices) have bounded chromatic number. This problem was raised by Erdos and Simonovits in 1973 who pointed out that there is no such result for c

  9. On Chromatic no. of 3K1-free graphs and R(3, k)

    OpenAIRE

    Dhurandhar, Medha S.

    2012-01-01

    Here we prove that if G has independence no. 2 and clique size omega with omega less than or equal to 11, then (1) chromatic no. is less than or equal to (omega2+12omega-13)/8, if omega is odd, and (2) chromatic no. is less than or equal to (omega2+10omega)/8, if omega is even. We further conjecture that the results are true in general for all omega. We also conjecture that (A) if omega is odd and R(3, omega) is even, then R(3, omega) = (omega2+8omega-9)/4, (B) if omega and R(3, omega) are bo...

  10. Coded-subcarrier-aided chromatic dispersion monitoring scheme for flexible optical OFDM networks.

    Science.gov (United States)

    Tse, Kam-Hon; Chan, Chun-Kit

    2014-08-11

    A simple coded-subcarrier aided scheme is proposed to perform chromatic dispersion monitoring in flexible optical OFDM networks. A pair of coded label subcarriers is added to both edges of the optical OFDM signal spectrum at the edge transmitter node. Upon reception at any intermediate or the receiver node, chromatic dispersion estimation is performed, via simple direct detection, followed by electronic correlation procedures with the designated code sequences. The feasibility and the performance of the proposed scheme have been experimentally characterized. It provides a cost-effective monitoring solution for the optical OFDM signals across intermediate nodes in flexible OFDM networks.

  11. Differential algebraic method for arbitrary order curvilinear-axis combined geometric-chromatic aberration analysis

    International Nuclear Information System (INIS)

    Cheng Min; Tang Tiantong; Lu Yilong; Yao Zhenhua

    2003-01-01

    The principle of differential algebra is applied to analyse and calculate arbitrary order curvilinear-axis combined geometric-chromatic aberrations of electron optical systems. Expressions of differential algebraic form of high order combined aberrations are obtained and arbitrary order combined aberrations can be calculated numerically. As an example, a typical wide electron beam focusing system with curved optical axes named magnetic immersion lens has been studied. All the second-order and third-order combined geometric-chromatic aberrations of the lens have been calculated, and the patterns of the corresponding geometric aberrations and combined aberrations have been given as well

  12. New chromaticity compensation approach and dynamic aperture increase in the SSRF storage ring

    International Nuclear Information System (INIS)

    Tian Shunqiang; Hou Jie; Chen Guangling; Chinese Academy of Sciences, Beijing; Liu Guimin

    2008-01-01

    Strong chromatic sextupoles used to compensate natural chromaticities in the third generation light source storage ring usually reduce dynamic aperture drastically. Many optimization methods can be used to find solutions that provide large dynamic apertures. This paper discusses a new optimization approach of sextupole strengths with step-by-step procedure, which is applied in the SSRF storage ring, and a better solution is obtained. Investigating driving terms generated by the sextupoles in every step can analyze their convergences and guide the weight setting among different terms in object function of the single resonance approach based on the perturbation theory. (authors)

  13. On-line analysis of water contamination by organic compounds; On-line-Analytik der Wasserverschmutzung durch organische Substanzen

    Energy Technology Data Exchange (ETDEWEB)

    Wagt, R. van der; Vos, F. de [Skalar Analytical (Netherlands); Babichenko, S.; Poryvkina, L. [Institute of Ecology, Tallinn (Estonia)

    1999-08-01

    In many environmental applications decomposing the mixture of substances in the water into its various chemical ingredients, for subsequent analysis, is a very complicated task. The most productive approach to on-line diagnosis is to treat the object as an integral spectroscopic sample, characterized by certain specific Spectral Fluorescent Signatures (SFS). The SFS are recorded as a matrix of fluorescent intensity of organic compounds in water, in co-ordinates of excitation and emission spectra, providing a three-dimensional spectrum. Spectral windows of SFS are defined by fluorescent characteristics of basic groups of organic substances in the water sample. The novel Skalar Fluo Imager, based on this principle, is intended for the analysis of organic compounds in natural, domestic, and technological waters in an on-line mode. (orig.) [German] In vielen Umweltschutzanwendungen stellt die Auftrennung eines Substanzgemisches zum Zweck der Analyse eine sehr komplizierte Aufgabe dar. Ein erfolgversprechender Ansatz fuer eine on-line-Diagnostik besteht darin, das Objekt als integrale Spektroskopieprobe zu betrachten, die durch bestimmte spezifische Spektral-Fluoreszenz-Signaturen (SFS) charakterisiert wird. Diese werden als Fluoreszenz-Intensitaets-Matrix organischer Verbindungen in Wasser dargestellt, mit Anregungs- und Emissionsspektren als weiteren Koordinaten, wodurch ein dreidimensionales Spektrum entsteht. Spektrale Fenster der SFS sind definiert als Fluoreszenzcharakteristika von Funktionsgruppen organischer Substanzen in der Wasserprobe. Der auf diesem Prinzip basierende Skalar Fluo Imager ist fuer die on-line-Analyse organischer Bestandteile in natuerlichen, Haus- und technischen Waessern gedacht. (orig.)

  14. Automatic Delineation of On-Line Head-And-Neck Computed Tomography Images: Toward On-Line Adaptive Radiotherapy

    International Nuclear Information System (INIS)

    Zhang Tiezhi; Chi Yuwei; Meldolesi, Elisa; Yan Di

    2007-01-01

    Purpose: To develop and validate a fully automatic region-of-interest (ROI) delineation method for on-line adaptive radiotherapy. Methods and Materials: On-line adaptive radiotherapy requires a robust and automatic image segmentation method to delineate ROIs in on-line volumetric images. We have implemented an atlas-based image segmentation method to automatically delineate ROIs of head-and-neck helical computed tomography images. A total of 32 daily computed tomography images from 7 head-and-neck patients were delineated using this automatic image segmentation method. Manually drawn contours on the daily images were used as references in the evaluation of automatically delineated ROIs. Two methods were used in quantitative validation: (1) the dice similarity coefficient index, which indicates the overlapping ratio between the manually and automatically delineated ROIs; and (2) the distance transformation, which yields the distances between the manually and automatically delineated ROI surfaces. Results: Automatic segmentation showed agreement with manual contouring. For most ROIs, the dice similarity coefficient indexes were approximately 0.8. Similarly, the distance transformation evaluation results showed that the distances between the manually and automatically delineated ROI surfaces were mostly within 3 mm. The distances between two surfaces had a mean of 1 mm and standard deviation of <2 mm in most ROIs. Conclusion: With atlas-based image segmentation, it is feasible to automatically delineate ROIs on the head-and-neck helical computed tomography images in on-line adaptive treatments

  15. On-line soft sensing in upstream bioprocessing.

    Science.gov (United States)

    Randek, Judit; Mandenius, Carl-Fredrik

    2018-02-01

    This review provides an overview and a critical discussion of novel possibilities of applying soft sensors for on-line monitoring and control of industrial bioprocesses. Focus is on bio-product formation in the upstream process but also the integration with other parts of the process is addressed. The term soft sensor is used for the combination of analytical hardware data (from sensors, analytical devices, instruments and actuators) with mathematical models that create new real-time information about the process. In particular, the review assesses these possibilities from an industrial perspective, including sensor performance, information value and production economy. The capabilities of existing analytical on-line techniques are scrutinized in view of their usefulness in soft sensor setups and in relation to typical needs in bioprocessing in general. The review concludes with specific recommendations for further development of soft sensors for the monitoring and control of upstream bioprocessing.

  16. On-line corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2004-01-01

    ), Electrochemical Noise (EN) and Zero Resistance Ammetry (ZRA). Electrochemical Resistance (ER) has also been used to measure corrosion. The method traditionally only measures corrosion off-line but with newly developed high-sensitive ER technique developed by MetriCorr in Denmark, on-line monitoring is possible...... complicates the chemistry of the environment. Hydrogen sulphide is present in geothermal systems and can be formed as a by-product of sulphate-reducing-bacteria (SRB). The application of electrochemical methods makes on-line monitoring possible. These methods include: Linear Polarization Resistance (LPR....... In order to assess both general corrosion and localized corrosion, it is necessary to apply more than one monitoring technique simultaneously, ZRA or EN for measuring localized corrosion and LPR or ER for measuring general corrosion rate. The advantage of monitoring localized corrosion is indisputable...

  17. On-line sources of toxicological information in Canada

    International Nuclear Information System (INIS)

    Racz, William J.; Ecobichon, Donald J.; Baril, Marc

    2003-01-01

    This paper will provide an overview of the on-line resources available in toxicology in Canada. It will describe a brief history of The Society of Toxicology of Canada, with reference to other societies and also provide information on education, research and other resources related to toxicology. Toxicology in Canada emerged as a distinct and vibrant discipline following the thalidomide tragedy of the 1960s. In the pharmaceutical industry and government, toxicology was readily established as an essential component of drug development and safety, and as the need for toxicologists expanded, training programs were established, usually in collaboration with departments of pharmacology. In the last two to three decades other disciplines, environmental biology, analytical chemistry and epidemiology joined the ranks of toxicology. The on-line sources of toxicology information are rapidly expanding. This article describes those sources considered by the authors to be important from a national and international perspective. The majority of these sources are professional organizations and government agencies

  18. On-line chemistry monitoring for the secondary side

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Babcock and Wilcox (B and W) has developed a computerized water chemistry data acquisition and management system for nuclear plant secondary coolant systems. The Integrated Water Chemistry Monitoring System (IWCMS) provides on-line monitoring of conditions and rapid trend analysis of sampled data. So far it has been installed at GPU Three Mile Island unit 1 and at Toledo Edison Davis-Besse. The IWCMS meets the following utility needs for monitoring power plant chemistry: control of chemistry conditions to minimize corrosion and extend component/system life; continuous analysis of data from on-line detectors and grab samples; expediting of transient recovery actions with trend, alarm and evaluation capability; provision for rapid sharing of useful operational chemistry information; concentration of attention on evaluation instead of data manipulation. The system is composed of three functional parts: data acquisition hardware; PC-based computer system and customised system software. (author)

  19. On-line application of the PANTHER advanced nodal code

    International Nuclear Information System (INIS)

    Hutt, P.K.; Knight, M.P.

    1992-01-01

    Over the last few years, Nuclear Electric has developed an integrated core performance code package for both light water reactors (LWRs) and advanced gas-cooled reactors (AGRs) that can perform a comprehensive range of calculations for fuel cycle design, safety analysis, and on-line operational support for such plants. The package consists of the following codes: WIMS for lattice physics, PANTHER whole reactor nodal flux and AGR thermal hydraulics, VIPRE for LWR thermal hydraulics, and ENIGMA for fuel performance. These codes are integrated within a UNIX-based interactive system called the Reactor Physics Workbench (RPW), which provides an interactive graphic user interface and quality assurance records/data management. The RPW can also control calculational sequences and data flows. The package has been designed to run both off-line and on-line accessing plant data through the RPW

  20. UniFlex - Collaborative on-line learning environment tool

    Directory of Open Access Journals (Sweden)

    Ole Borch

    2004-05-01

    Full Text Available

    Første gang publiceret i UNEV nr. 2: E-læringsplatforme - muligheder og potentialer, januar - marts 2004, red. Tom Nyvand og Michael Pedersen. ISSN 1603-5518.

    Increasing demands for remote on-line education are changing the way teaching and learning is performed. New behavior in using pedagogy and supporting technology is needed to drive the learning process. To facilitate the use of services for selected activities to participants in distance education, a web site named UniFlex (University Flexible learning has been developed and brought into use. The site is a comprehensive set of bookmarks including course taking, upload/download, and - of special significance - collaborative on-line project work. UniFlex has been developed to meet the requirement for a simple and cheap personalized interactive site, supporting problem oriented and project organized study form, which has characterized Aalborg University for more than 27 years.

  1. UniFlex - Collaborative on-line learning environment tool

    Directory of Open Access Journals (Sweden)

    Ole Borch

    2004-03-01

    Full Text Available Første gang publiceret i UNEV nr. 2: E-læringsplatforme - muligheder og potentialer, januar - marts 2004, red. Tom Nyvand og Michael Pedersen. ISSN 1603-5518. Increasing demands for remote on-line education are changing the way teaching and learning is performed. New behavior in using pedagogy and supporting technology is needed to drive the learning process. To facilitate the use of services for selected activities to participants in distance education, a web site named UniFlex (University Flexible learning has been developed and brought into use. The site is a comprehensive set of bookmarks including course taking, upload/download, and - of special significance - collaborative on-line project work. UniFlex has been developed to meet the requirement for a simple and cheap personalized interactive site, supporting problem oriented and project organized study form, which has characterized Aalborg University for more than 27 years.

  2. On-line analyzers to distributed control system linking

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, S.F.; Buchanan, B.R.; Sanders, M.A.

    1990-01-01

    The Analytical Development Section (ADS) of the Savannah River Laboratory is developing on-line analyzers to monitor various site processes. Data from some of the on-line analyzers (OLA's) will be used for process control by distributed control systems (DCS's) such as the Fisher PRoVOX. A problem in the past has been an efficient and cost effective way to get analyzer data onto the DCS data highway. ADS is developing a system to accomplish the linking of OLA's to PRoVOX DCS's. The system will be described, and results of operation in a research and development environment given. Plans for the installation in the production environment will be discussed.

  3. On-line Ramsey Numbers for Paths and Stars

    Directory of Open Access Journals (Sweden)

    Jaroslaw Grytczuk

    2008-08-01

    Full Text Available We study on-line version of size-Ramsey numbers of graphs defined via a game played between Builder and Painter: in one round Builder joins two vertices by an edge and Painter paints it red or blue. The goal of Builder is to force Painter to create a monochromatic copy of a fixed graph H in as few rounds as possible. The minimum number of rounds (assuming both players play perfectly is the on-line Ramsey number r(H of the graph H. We determine exact values of r(H for a few short paths and obtain a general upper bound r(Pn ≤ 4n-7. We also study asymmetric version of this parameter when one of the target graphs is a star Sn with n edges. We prove that r(Sn,H≤n ·e(H when H is any tree, cycle or clique.

  4. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  5. On-Line Metrology with Conoscopic Holography: Beyond Triangulation

    Directory of Open Access Journals (Sweden)

    Ignacio Álvarez

    2009-09-01

    Full Text Available On-line non-contact surface inspection with high precision is still an open problem. Laser triangulation techniques are the most common solution for this kind of systems, but there exist fundamental limitations to their applicability when high precisions, long standoffs or large apertures are needed, and when there are difficult operating conditions. Other methods are, in general, not applicable in hostile environments or inadequate for on-line measurement. In this paper we review the latest research in Conoscopic Holography, an interferometric technique that has been applied successfully in this kind of applications, ranging from submicrometric roughness measurements, to long standoff sensors for surface defect detection in steel at high temperatures.

  6. The Bochum on-line data acquisition system

    International Nuclear Information System (INIS)

    Paul, H.J.; Freiesleben, H.

    1986-01-01

    We describe an on-line data acquisition system based on a PDP 11 computer with CAMAC hardware. The software fully exploits the real-time features of the RSX-11M operating system. The basic characteristics of the program package, mainly written in FORTRAN 77, are: multitasking, shared common blocks, dynamical access to CAMAC hardware and data, and command orientated user interface. The system is particularly tailored for data acquisition in list mode of up to 64 parameters. (orig.)

  7. Recovery Strategies in On-Line Service Failure

    OpenAIRE

    Ozuem, Wilson; Lancaster, Geoff

    2013-01-01

    Despite a proliferation of a number of studies on service failures and recovery in e-service settings, there is a paucity of knowledge of ways in which service failures and recovery practices are implemented in the fashion industry. Drawing on constructivist perspective, this study offers a new perspective on an effective relational mechanism that would bridge the rupture between consumers and companies particularly in the on-line fashion sector. The analysis adds to studies on service failur...

  8. Understanding Cognitive Load Using On-line Dictionaries

    OpenAIRE

    Robert F. , Dilenschneider

    2017-01-01

    Cognitive Load Theory may useful for language instructors to understand how the look up conditions ofusing an on-line dictionary might influence learning. This paper first reviews previous studies that haveinvestigated dictionary use for vocabulary acquisition and reading comprehension Second, it explainsthe various elements of Cognitive Load Theory. Third, it describes how Cognitive Load Theory appliesto language learners' to learn unknown words and comprehend texts Last, it discusses the pe...

  9. On-line diagnostics for a real time system

    International Nuclear Information System (INIS)

    Sreenivasan, P.

    1976-01-01

    The purpose of an on-line diagnostics is to infuse the ability of self diagnosing in an online computer to enhance its dependability in a real time system. Such a diagnostics evolved for the CDPS of the Fast Breeder Test Reactor at Kalpakkam is reported. The two phases of the diagnostics, i.e., the malfunction detection and post detection action are described in some detail. (A.K.)

  10. Isocele I, the Orsay synchrocyclotron on-line separator

    International Nuclear Information System (INIS)

    Caruette, A.; Ferro, A.; Foucher, R.

    1976-01-01

    The main characteristics of the isotope separator Isocele 1 are described. This medium current separator was on line with the Orsay synchrocyclotron (155 MeV p, or 210 MeV 3 He) from March 1974 up to May 1975. Results obtained with different targets (Au, Bi, Er, Pt, Sn, Th) are summarized. They confirm the efficiency of medium current separators of this type [fr

  11. A decision support system for on-line leakage localization

    OpenAIRE

    Meseguer, Jordi; Mirats-Tur, Josep M.; Cembrano, Gabriela; Puig, Vicenç; Quevedo, Joseba; Pérez, Ramon; Sanz, Gerard; Ibarra, David

    2014-01-01

    This paper describes a model-driven decision-support system (software tool) implementing a model-based methodology for on-line leakage detection and localization which is useful for a large class of water distribution networks. Since these methods present a certain degree of complexity which limits their use to experts, the proposed software tool focuses on the integration of a method emphasizing its use by water network managers as a decision support system. The proposed software tool integr...

  12. On-line learning in radial basis functions networks

    OpenAIRE

    Freeman, Jason; Saad, David

    1997-01-01

    An analytic investigation of the average case learning and generalization properties of Radial Basis Function Networks (RBFs) is presented, utilising on-line gradient descent as the learning rule. The analytic method employed allows both the calculation of generalization error and the examination of the internal dynamics of the network. The generalization error and internal dynamics are then used to examine the role of the learning rate and the specialization of the hidden units, which gives ...

  13. On-line production of [11C]cyanogen bromide

    International Nuclear Information System (INIS)

    Westerberg, G.; Laangstroem, B.

    1997-01-01

    The electrophilic labelling precursor [ 11 C]cyanogen bromide was produced in 95% radiochemical yield (decay-corrected) from hydrogen [ 11 C]cyanide within 3 min from the end of bombardment using a simple and convenient solid-phase on-line procedure. The [ 11 C]cyanogen bromide has been used in the synthesis of a number of labelled compounds for use in positron emission tomography. (author)

  14. On-line Monitoring System for Power Transformers

    Directory of Open Access Journals (Sweden)

    Alexandru HOTEA

    2016-12-01

    Full Text Available Power transformers are the most important and expensive equipment from the electricity transmission system, so it is very important to know the real state of health of such equipment in every moment. De-energizing the power transformer accidentally due to internal defects can generate high costs. Annual maintenance proved to be ineffective in many cases to determine the internal condition of the equipment degradation due to faults rapidly evolving. An On-line Monitoring System for Power Transformers help real-time condition assessment and to detect errors early enough to take action to eliminate or minimize them. After abnormality detected, it is still important to perform full diagnostic tests to determine the exact condition of the equipment. On-line monitoring systems can help increase the level of availability and reliability of power transformers and lower costs of accidental interruption. This paper presents cases studies on several power transformers equipped with on-line monitoring systems from Transelectrica substation.

  15. On-Line Fringe Tracking and Prediction at IOTA

    Science.gov (United States)

    Wilson, Edward; Mah, Robert; Lau, Sonie (Technical Monitor)

    1999-01-01

    The Infrared/Optical Telescope Array (IOTA) is a multi-aperture Michelson interferometer located on Mt. Hopkins near Tucson, Arizona. To enable viewing of fainter targets, an on-line fringe tracking system is presently under development at NASA Ames Research Center. The system has been developed off-line using actual data from IOTA, and is presently undergoing on-line implementation at IOTA. The system has two parts: (1) a fringe tracking system that identifies the center of a fringe packet by fitting a parametric model to the data; and (2) a fringe packet motion prediction system that uses characteristics of past fringe packets to predict fringe packet motion. Combined, this information will be used to optimize on-line the scanning trajectory, resulting in improved visibility of faint targets. Fringe packet identification is highly accurate and robust (99% of the 4000 fringe packets were identified correctly, the remaining 1% were either out of the scan range or too noisy to be seen) and is performed in 30-90 milliseconds on a Pentium II-based computer. Fringe packet prediction, currently performed using an adaptive linear predictor, delivers a 10% improvement over the baseline of predicting no motion.

  16. Review of trigger and on-line processors at SLAC

    International Nuclear Information System (INIS)

    Lankford, A.J.

    1984-07-01

    The role of trigger and on-line processors in reducing data rates to manageable proportions in e + e - physics experiments is defined not by high physics or background rates, but by the large event sizes of the general-purpose detectors employed. The rate of e + e - annihilation is low, and backgrounds are not high; yet the number of physics processes which can be studied is vast and varied. This paper begins by briefly describing the role of trigger processors in the e + e - context. The usual flow of the trigger decision process is illustrated with selected examples of SLAC trigger processing. The features are mentioned of triggering at the SLC and the trigger processing plans of the two SLC detectors: The Mark II and the SLD. The most common on-line processors at SLAC, the BADC, the SLAC Scanner Processor, the SLAC FASTBUS Controller, and the VAX CAMAC Channel, are discussed. Uses of the 168/E, 3081/E, and FASTBUS VAX processors are mentioned. The manner in which these processors are interfaced and the function they serve on line is described. Finally, the accelerator control system for the SLC is outlined. This paper is a survey in nature, and hence, relies heavily upon references to previous publications for detailed description of work mentioned here. 27 references, 9 figures, 1 table

  17. On-line plant-wide monitoring using neural networks

    International Nuclear Information System (INIS)

    Turkcan, E.; Ciftcioglu, O.; Eryurek, E.; Upadhyaya, B.R.

    1992-06-01

    The on-line signal analysis system designed for a multi-level mode operation using neural networks is described. The system is capable of monitoring the plant states by tracking different number of signals up to 32 simultaneously. The data used for this study were acquired from the Borssele Nuclear Power Plant (PWR type), and using the on-line monitoring system. An on-line plant-wide monitoring study using a multilayer neural network model is discussed in this paper. The back-propagation neural network algorithm is used for training the network. The technique assumes that each physical state of the power plant can be represented by a unique pattern of instrument readings which can be related to the condition of the plant. When disturbance occurs, the sensor readings undergo a transient, and form a different set of patterns which represent the new operational status. Diagnosing these patterns can be helpful in identifying this new state of the power plant. To this end, plant-wide monitoring with neutral networks is one of the new techniques in real-time applications. (author). 9 refs.; 5 figs

  18. Designing effective on-line continuing medical education.

    Science.gov (United States)

    Zimitat, Craig

    2001-03-01

    The Internet, and new information and communication technologies available through the Internet, provides medical educators with an opportunity to develop unique on-line learning environments with real potential to improve physicians' knowledge and effect change in their clinical practice. There are approximately 100 websites offering on-line CME courses in the USA alone. However, few of these CME courses appear to be based on sound educational principles or CME research and may have little chance of achieving the broader goals of CME. The majority of these courses closely resemble their traditional counterparts (e.g. paper-based books are now electronic books) and appear to be mere substitutions for old-technology CME resources. Whilst some CME providers add unique features of the Internet to enrich their websites, they do not employ strategies to optimize the learning opportunities afforded by this new technology. The adoption of adult learning principles, reflective practice and problem-based approaches can be used as a foundation for sound CME course design. In addition, knowledge of Internet technology and the learning opportunities it affords, together with strategies to maintain participation and new assessment paradigms, are all needed for developing online CME. We argue for an evidence-based and strategic approach to the development of on-line CME courses designed to enhance physician learning and facilitate change in clinical behaviour.

  19. On-line radiation teaching materials using IT technology

    International Nuclear Information System (INIS)

    Inoue, Hiroyoshi

    2005-01-01

    We developed the on-line radiation teaching materials using the Internet, in order to provide the teaching support materials of atomic power and radiation educations in on-school study, as well as to create the complementary study system in off-school study. The themes of teaching materials were selected from requests by teachers. In the case of an elementary school, the teaching material 'an environmental problem and atomic power' was created as the aggregate of each content for study without boundary between subjects. The teaching material 'medical treatment and radiation' was created for junior high school students to raise the individual knowledge. In the case of a high school, the teaching material nucleus and radiation' was prepared to supplement the physical study of students. The on-line teaching materials were tried to 300 junior high school and high school students, 68% of students answered that the teaching material is effective to understand atomic power and radiation, though 17% answered they were not effective. Although there are problems to prepare IT learning equipments and learning follow-up system in the material, it is suggested that the on-line teaching materials will provide the novel learning system including debates for the study. This method has no limitation of time and place. (author)

  20. On-line fouling monitor for heat exchangers

    International Nuclear Information System (INIS)

    Tsou, J.L.

    1995-01-01

    Biological and/or chemical fouling in utility service water system heat exchangers adversely affects operation and maintenance costs, and reduced heat transfer capability can force a power deaerating or even a plant shut down. In addition, service water heat exchanger performance is a safety issue for nuclear power plants, and the issue was highlighted by NRC in Generic Letter 89-13. Heat transfer losses due to fouling are difficult to measure and, usually, quantitative assessment of the impact of fouling is impossible. Plant operators typically measure inlet and outlet water temperatures and flow rates and then perform complex calculations for heat exchanger fouling resistance or ''cleanliness''. These direct estimates are often imprecise due to inadequate instrumentation. Electric Power Research Institute developed and patented an on-line condenser fouling monitor. This monitor may be installed in any location within the condenser; does not interfere with routine plant operations, including on-line mechanical and chemical treatment methods; and provides continuous, real-time readings of the heat transfer efficiency of the instrumented tube. This instrument can be modified to perform on-line monitoring of service water heat exchangers. This paper discusses the design, construction of the new monitor, and algorithm used to calculate service water heat exchanger fouling

  1. Denmark's on - line early warning radiation monitoring network

    International Nuclear Information System (INIS)

    Walmod-Larsen, O.; Lippert, J.

    1990-01-01

    In Denmark an emergency response coordination committee was set up to cope with the problems after the Chernobyl accident with participation of all relevant authorities. For help in an emergency situation the ARGOS (Accident Reporting and Guiding Operational System), system will be put into use. The ARGOS emergency evaluation computer system, which has been developed in cooperation with the Danish Environmental Protection Agency, is in operation in connection with the emergency planning for the east region of Denmark with regard to the Swedish nuclear power plant operating at Barseback. Inputs of measurement data are on-line available on data screens for evaluation in the emergency coordination centers, presented on suitable geographical maps, showing iso-contours calculated from the input. In case of an alert situation other systems can be put in operation, f.ex. mobile measuring units from the CDEPA's local, operational emergency centers. Their readings can then be put into the computing system parallel to the on-line stations and be presented by the ARGOS-system for evaluation in the emergency command centers. If another national authority in an alert situation requests a transfer of measurement data, and if this is agreed upon by the competent Danish authority, then the transfer can be arranged from the ARGOS-system, through agreed transmission channels. At present the ARGOS system is being improved and expanded by RNL to cover the whole Danish region and to present measurements from the on-line warning system

  2. Nonlinear Elasticity

    Science.gov (United States)

    Fu, Y. B.; Ogden, R. W.

    2001-05-01

    This collection of papers by leading researchers in the field of finite, nonlinear elasticity concerns itself with the behavior of objects that deform when external forces or temperature gradients are applied. This process is extremely important in many industrial settings, such as aerospace and rubber industries. This book covers the various aspects of the subject comprehensively with careful explanations of the basic theories and individual chapters each covering a different research direction. The authors discuss the use of symbolic manipulation software as well as computer algorithm issues. The emphasis is placed firmly on covering modern, recent developments, rather than the very theoretical approach often found. The book will be an excellent reference for both beginners and specialists in engineering, applied mathematics and physics.

  3. Nonlinear resonances

    CERN Document Server

    Rajasekar, Shanmuganathan

    2016-01-01

    This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

  4. Effects of iron stress on chromatic adaptation by natural phytoplankton communities in the Southern Ocean

    NARCIS (Netherlands)

    van Leeuwe, M.A.; Timmermans, K.R.; Witte, H.J.; Kraay, G.W.; Veldhuis, M.J.W.; de Baar, H.J.W.

    1998-01-01

    Effects of iron stress on chromatic adaptation were studied in natural phytoplankton communities collected in the Pacific region of the Southern Ocean. Iron enrichment experiments (48 to 72 h) were performed, incubating plankton communities under white, green and blue light respectively, with and

  5. Segmentation of color images by chromaticity features using self-organizing maps

    Directory of Open Access Journals (Sweden)

    Farid García-Lamont

    2016-05-01

    Full Text Available Usually, the segmentation of color images is performed using cluster-based methods and the RGB space to represent the colors. The drawback with these methods is the a priori knowledge of the number of groups, or colors, in the image; besides, the RGB space issensitive to the intensity of the colors. Humans can identify different sections within a scene by the chromaticity of its colors of, as this is the feature humans employ to tell them apart. In this paper, we propose to emulate the human perception of color by training a self-organizing map (SOM with samples of chromaticity of different colors. The image to process is mapped to the HSV space because in this space the chromaticity is decoupled from the intensity, while in the RGB space this is not possible. Our proposal does not require knowing a priori the number of colors within a scene, and non-uniform illumination does not significantly affect the image segmentation. We present experimental results using some images from the Berkeley segmentation database by employing SOMs with different sizes, which are segmented successfully using only chromaticity features.

  6. Informational primacy of visual dimensions: specialized roles for luminance and chromaticity in figure-ground perception.

    Science.gov (United States)

    Yamagishi, N; Melara, R D

    2001-07-01

    Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.

  7. Photographic simulation of off-axis blurring due to chromatic aberration in spectacle lenses.

    Science.gov (United States)

    Doroslovački, Pavle; Guyton, David L

    2015-02-01

    Spectacle lens materials of high refractive index (nd) tend to have high chromatic dispersion (low Abbé number [V]), which may contribute to visual blurring with oblique viewing. A patient who noted off-axis blurring with new high-refractive-index spectacle lenses prompted us to do a photographic simulation of the off-axis aberrations in 3 readily available spectacle lens materials, CR-39 (nd = 1.50), polyurethane (nd = 1.60), and polycarbonate (nd = 1.59). Both chromatic and monochromatic aberrations were found to cause off-axis image degradation. Chromatic aberration was more prominent in the higher-index materials (especially polycarbonate), whereas the lower-index CR-39 had more astigmatism of oblique incidence. It is important to consider off-axis aberrations when a patient complains of otherwise unexplained blurred vision with a new pair of spectacle lenses, especially given the increasing promotion of high-refractive-index materials with high chromatic dispersion. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Hexavalent chromate reduction during growth and by immobilized cells of arthrobacter sp. suk 1205

    International Nuclear Information System (INIS)

    Dey, S.; Paul, A.K.

    2017-01-01

    The chromate reducing actinomycetes, Arthrobacter sp. SUK 1205, isolated from chromite mine overburden of Odisha, India exhibited significant chromate reduction during growth with characteristic formation of pale green insoluble precipitate. Reduction of chromate increased with increase in inoculum density but the reduction potential declined as and when Cr(VI) concentration in the medium was increased. Chromate reducing efficiency was promoted when glycerol and glucose were used as electron donors and pH and temperature were maintained at 7.0 and 35 degree C, respectively. The reduction process was inhibited by several metal ions and metabolic inhibitors but not by Cu(II), Mn(II) and DNP. Among the matrices tested for whole cell immobilization, Ca-alginate immobilized whole cells were found to be most effective and were comparable with non-immobilized cells. Minimal salts (MS) medium was the most effective base for Cr(VI) reduction studies with immobilized cells. Under such conditions, the immobilized cells retained their enzymatic activity at least for 4 consecutive cycles indicating the potential of Arthrobacter sp. SUK 1205 in bioremediation of environmental chromium pollution. (author)

  9. Experimental demonstration of the maximum likelihood-based chromatic dispersion estimator for coherent receivers

    DEFF Research Database (Denmark)

    Borkowski, Robert; Johannisson, Pontus; Wymeersch, Henk

    2014-01-01

    We perform an experimental investigation of a maximum likelihood-based (ML-based) algorithm for bulk chromatic dispersion estimation for digital coherent receivers operating in uncompensated optical networks. We demonstrate the robustness of the method at low optical signal-to-noise ratio (OSNR...

  10. Chromatic response of polydiacetylene vesicle induced by the permeation of methotrexate.

    Science.gov (United States)

    Shin, Min Jae; Kim, Ye Jin; Kim, Jong-Duk

    2015-07-07

    The noble vesicular system of polydiacetylene showed a red shift using two types of detecting systems. One of the systems involves the absorption of target materials from the outer side of the vesicle, and the other system involves the permeation through the vesicular layers from within the vesicle. The chromatic mixed vesicles of N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA) and dimethyldioctadecylammonium chloride (DODAC) were fabricated by sonication, followed by polymerization by UV irradiation. The stability of monomeric vesicles was observed to increase with the polymerization of the vesicles. Methotrexate was used as a target material. The polymerized mixed vesicles having a blue color were exposed to a concentration gradient of methotrexate, and a red shift was observed indicating the adsorption of methotrexate on the polydiacetylene bilayer. In order to check the chromatic change by the permeation of methotrexate, we separated the vesicle portion, which contained methotrexate inside the vesicle, and checked chromatic change during the permeation of methotrexate through the vesicle. The red shift apparently indicates the disturbance in the bilayer induced by the permeation of methotrexate. The maximum contrast of color appeared at the equal molar ratio of AEPCDA and DODAC, indicating that the formation of flexible and deformable vesicular layers is important for red shift. Therefore, it is hypothesized that the system can be applicable for the chromatic detection of the permeation of methotrexate through the polydiacetylene layer.

  11. Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm.

    Science.gov (United States)

    Barkan, Yuval; Spitzer, Hedva

    2018-01-01

    The human visual system faces many challenges, among them the need to overcome the imperfections of its optics, which degrade the retinal image. One of the most dominant limitations is longitudinal chromatic aberration (LCA), which causes short wavelengths (blue light) to be focused in front of the retina with consequent blurring of the retinal chromatic image. The perceived visual appearance, however, does not display such chromatic distortions. The intriguing question, therefore, is how the perceived visual appearance of a sharp and clear chromatic image is achieved despite the imperfections of the ocular optics. To address this issue, we propose a neural mechanism and computational model, based on the unique properties of the S -cone pathway. The model suggests that the visual system overcomes LCA through two known properties of the S channel: (1) omitting the contribution of the S channel from the high-spatial resolution pathway (utilizing only the L and M channels). (b) Having large and coextensive receptive fields that correspond to the small bistratified cells. Here, we use computational simulations of our model on real images to show how integrating these two basic principles can provide a significant compensation for LCA. Further support for the proposed neuronal mechanism is given by the ability of the model to predict an enigmatic visual phenomenon of large color shifts as part of the assimilation effect.

  12. Self-referenced axial chromatic dispersion measurement in multiphoton microscopy through 2-color THG imaging.

    Science.gov (United States)

    Du, Yu; Zhuang, Ziwei; He, Jiexing; Liu, Hongji; Qiu, Ping; Wang, Ke

    2018-05-16

    With tunable excitation light, multiphoton microscopy (MPM) is widely used for imaging biological structures at subcellular resolution. Axial chromatic dispersion, present in virtually every transmissive optical system including the multiphoton microscope, leads to focal (and the resultant image) plane separation. Here we demonstrate experimentally a technique to measure the axial chromatic dispersion in a multiphoton microscope, using simultaneous 2-color third-harmonic generation (THG) imaging excited by a 2-color soliton source with tunable wavelength separation. Our technique is self-referenced, eliminating potential measurement error when 1-color tunable excitation light is used which necessitates reciprocating motion of the mechanical translation stage. Using this technique, we demonstrate measured axial chromatic dispersion with 2 different objective lenses in a multiphoton microscope. Further measurement in a biological sample also indicates that this axial chromatic dispersion, in combination with 2-color imaging, may open up opportunity for simultaneous imaging of two different axial planes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Chromatic and Achromatic Spatial Resolution of Local Field Potentials in Awake Cortex.

    Science.gov (United States)

    Jansen, Michael; Li, Xiaobing; Lashgari, Reza; Kremkow, Jens; Bereshpolova, Yulia; Swadlow, Harvey A; Zaidi, Qasim; Alonso, Jose-Manuel

    2015-10-01

    Local field potentials (LFPs) have become an important measure of neuronal population activity in the brain and could provide robust signals to guide the implant of visual cortical prosthesis in the future. However, it remains unclear whether LFPs can detect weak cortical responses (e.g., cortical responses to equiluminant color) and whether they have enough visual spatial resolution to distinguish different chromatic and achromatic stimulus patterns. By recording from awake behaving macaques in primary visual cortex, here we demonstrate that LFPs respond robustly to pure chromatic stimuli and exhibit ∼2.5 times lower spatial resolution for chromatic than achromatic stimulus patterns, a value that resembles the ratio of achromatic/chromatic resolution measured with psychophysical experiments in humans. We also show that, although the spatial resolution of LFP decays with visual eccentricity as is also the case for single neurons, LFPs have higher spatial resolution and show weaker response suppression to low spatial frequencies than spiking multiunit activity. These results indicate that LFP recordings are an excellent approach to measure spatial resolution from local populations of neurons in visual cortex including those responsive to color. © The Author 2014. Published by Oxford University Press.

  14. Reversible Chromatic Response of Polydiacetylene Derivative Vesicles in D2O Solvent.

    Science.gov (United States)

    Shin, Min Jae; Kim, Jong-Duk

    2016-01-26

    The thermal chromatic sensitivity of polydiacetylenes (PDAs) with 10,12-pentacosadiynoic acid (PCDA) derivatives, which have a hydroxyl group (HEEPCDA) and an amine group (APPCDA), were investigated using D2O and H2O as solvents. The vesicle solution with polymerized HEEPCDA exhibited a reversible chromatic response during the heating and cooling cycle in D2O, but not in H2O. On the other hand, the vesicle solution with the polymerized APPCDA exhibited a reversible chromatic response in H2O during the heating and cooling cycle, but the color of the solution did not change much in D2O. The critical vesicle concentration of HEEPCDA was lower in D2O than in H2O, and the chromatic sensitivity of the polymerized vesicles to temperature was slower in D2O than in H2O. We think that it is due to D2O being a more highly structured solvent than H2O with the hydrogen bonding in D2O stronger than that in H2O.

  15. Spatial and temporal aspects of chromatic adaptation and their functional significance for colour constancy.

    Science.gov (United States)

    Werner, Annette

    2014-11-01

    Illumination in natural scenes changes at multiple temporal and spatial scales: slow changes in global illumination occur in the course of a day, and we encounter fast and localised illumination changes when visually exploring the non-uniform light field of three-dimensional scenes; in addition, very long-term chromatic variations may come from the environment, like for example seasonal changes. In this context, I consider the temporal and spatial properties of chromatic adaptation and discuss their functional significance for colour constancy in three-dimensional scenes. A process of fast spatial tuning in chromatic adaptation is proposed as a possible sensory mechanism for linking colour constancy to the spatial structure of a scene. The observed middlewavelength selectivity of this process is particularly suitable for adaptation to the mean chromaticity and the compensation of interreflections in natural scenes. Two types of sensory colour constancy are distinguished, based on the functional differences of their temporal and spatial scales: a slow type, operating at a global scale for the compensation of the ambient illumination; and a fast colour constancy, which is locally restricted and well suited to compensate region-specific variations in the light field of three dimensional scenes. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Neurochemical responses to chromatic and achromatic stimuli in the human visual cortex.

    Science.gov (United States)

    Bednařík, Petr; Tkáč, Ivan; Giove, Federico; Eberly, Lynn E; Deelchand, Dinesh K; Barreto, Felipe R; Mangia, Silvia

    2018-02-01

    In the present study, we aimed at determining the metabolic responses of the human visual cortex during the presentation of chromatic and achromatic stimuli, known to preferentially activate two separate clusters of neuronal populations (called "blobs" and "interblobs") with distinct sensitivity to color or luminance features. Since blobs and interblobs have different cytochrome-oxidase (COX) content and micro-vascularization level (i.e., different capacities for glucose oxidation), different functional metabolic responses during chromatic vs. achromatic stimuli may be expected. The stimuli were optimized to evoke a similar load of neuronal activation as measured by the bold oxygenation level dependent (BOLD) contrast. Metabolic responses were assessed using functional 1 H MRS at 7 T in 12 subjects. During both chromatic and achromatic stimuli, we observed the typical increases in glutamate and lactate concentration, and decreases in aspartate and glucose concentration, that are indicative of increased glucose oxidation. However, within the detection sensitivity limits, we did not observe any difference between metabolic responses elicited by chromatic and achromatic stimuli. We conclude that the higher energy demands of activated blobs and interblobs are supported by similar increases in oxidative metabolism despite the different capacities of these neuronal populations.

  17. Chromatic confocal microscopy for multi-depth imaging of epithelial tissue

    Science.gov (United States)

    Olsovsky, Cory; Shelton, Ryan; Carrasco-Zevallos, Oscar; Applegate, Brian E.; Maitland, Kristen C.

    2013-01-01

    We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue. PMID:23667789

  18. New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

    Science.gov (United States)

    Todd F. Shupe; Chung Y. Hse; Hui Pan

    2012-01-01

    Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the...

  19. The role of hexafluorozirconate in the formation of chromate conversion coatings on aluminum alloys

    International Nuclear Information System (INIS)

    Chidambaram, Devicharan; Clayton, Clive R.; Halada, Gary P.

    2006-01-01

    Aluminum based surfaces are routinely coated with a chromate based layer that provides unparalleled corrosion protection. Widely used conversion coating treatment formulations contain hexafluorozirconate as a major constituent besides chromate, ferricyanide, fluoride, and fluoborate. The function of hexafluorozirconate is the subject of this study as its function is still largely unknown. Hydrophobicity, surface morphology, and the chemistry of the surface, resulting from treatment with hexafluorozirconate, were studied using contact angle measurements, scanning electron microscopy, and energy dispersive spectroscopy, respectively. X-ray photoelectron spectroscopy was extensively utilized to determine the chemistry of the surface resulting from the hexafluorozirconate pretreatment. Our results indicate that fluoride ion containing hexafluorozirconate complex does not attack the oxide film in a manner that uncomplexed simple fluoride ion does. Hexafluorozirconate is involved in the formation of an Al-Zr-O-F based hydrated layer that increases the hydrophilicity of the surface, activates the surface, and lowers the corrosion resistance. These factors enhance the interaction of chromate with the alloy surface to result in the formation of a uniform conversion coating. Based on these results, a new model has been proposed for the formation of chromate conversion coatings

  20. On the chromatic number of a space with forbidden equilateral triangle

    International Nuclear Information System (INIS)

    Zvonarev, A E; Raigorodskii, A M; Kharlamova, A A; Samirov, D V

    2014-01-01

    We improve the Frankl-Rödl estimate for the product of the numbers of edges in uniform hypergraphs with forbidden cardinalities of the intersection of edges. By using this estimate, we obtain explicit bounds for the chromatic number of a space with forbidden monochromatic equilateral triangles. Bibliography: 31 titles

  1. Orbit, optics and chromaticity correction for PS2 negative momentum compaction lattices

    Energy Technology Data Exchange (ETDEWEB)

    Papaphilippou,Y.; Barranco, J.; Bartmann, W.; Benedikt, M.; Carli, C.; de Maria, R.; Peggs, S.; Trbojevic, D.

    2009-05-04

    The effect of magnet misalignments in the beam orbit and linear optics functions are reviewed and correction schemes are applied to the negative momentum compaction lattice of PS2. Chromaticity correction schemes are also proposed and tested with respect to off-momentum optics properties. The impact of the correction schemes in the dynamic aperture of the lattice is finally evaluated.

  2. Molybdate based Alternatives to Chromating as a Passivation Treatment for Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.; Møller, Per

    1994-01-01

    been developed that can be used to replace chromates in a wide range of applications. The process has been tested in a project set up by the Danish Government in 1989, at the Centre of Advanced Electroplating (CAG)in Denmark. Procedures used for the alternative process are similar to those used...

  3. Coding gaze tracking data with chromatic gradients for VR Exposure Therapy

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Grillon, Helena; De Heras Ciechomski, Pablo

    2007-01-01

    This article presents a simple and intuitive way to represent the eye-tracking data gathered during immersive virtual reality exposure therapy sessions. Eye-tracking technology is used to observe gaze movements during vir- tual reality sessions and the gaze-map chromatic gradient coding allows to...... is fully compatible with different VR exposure systems and provides clinically meaningful data....

  4. On the chromatic number of pentagon-free graphs of large minimum degree

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2007-01-01

    We prove that, for each fixed real number c > 0, the pentagon-free graphs of minimum degree at least cn (where n is the number of vertices) have bounded chromatic number. This problem was raised by Erdős and Simonovits in 1973. A similar result holds for any other fixed odd cycle, except the tria...

  5. SIMULTANEOUS DTERMINATION OF CHROMATE AND AROMATIC HYDROCARBONS IN ENVIRONMENTAL SAMPLES BY CAPILLARY ELECTROPHORESIS

    Science.gov (United States)

    An analytical method was developed to determine simultaneously, the inorganic anion CrO2-4, and organic aromatic compounds including benzoate, 2-Cl-benzoate, phenol, m-cresol and o-/p-cresol by capillary electrophoresis (CE). Chromate and the aromatics were separated in a relativ...

  6. Experimental verification of the minimum number of diffractive zones for effective chromatic correction in the LWIR

    Science.gov (United States)

    Ramsey, J. L.; Walsh, K. F.; Smith, M.; Deegan, J.

    2016-05-01

    With the move to smaller pixel sizes in the longwave IR region there has been a push for shorter focal length lenses that are smaller, cheaper and lighter and that resolve lower spatial frequencies. As a result lenses must have better correction for both chromatic and monochromatic aberrations. This leads to the increased use of aspheres and diffractive optical elements (kinoforms). With recent developments in the molding of chalcogenide materials these aspheres and kinoforms are more cost effective to manufacture. Without kinoforms the axial color can be on the order of 15 μm which degrades the performance of the lens at the Nyquist frequency. The kinoforms are now on smaller elements and are correcting chromatic aberration which is on the order of the design wavelength. This leads to kinoform structures that do not require large phase changes and therefore have 1.5 to just over 2 zones. The question becomes how many zones are required to correct small amounts of chromatic aberration in the system and are they functioning as predicted by the lens design software? We investigate both the design performance and the as-built performance of two designs that incorporate kinoforms for the correction of axial chromatic aberration.

  7. Chromaticity correction in the TRISTAN phase I main ring version 11

    International Nuclear Information System (INIS)

    Wu, Yingzhi.

    1984-05-01

    This report deals with chromaticity correction in the TRISTAN phase I main ring version 11. The program PATRICIA is used to track the trajectories of test particles over 2000 turns. The results show that particles with transverse initial amplitudes of at least 11 σ in both planes and with a synchrotron oscillation amplitude of 7 σsub(e) remain stable. (author)

  8. Effects of dispersion and longitudinal chromatic aberration on the focusing of isodiffracting pulsed Gaussian light beam

    International Nuclear Information System (INIS)

    Deng Dongmei; Guo Hong; Han Dingan; Liu Mingwei; Li Changfu

    2005-01-01

    Taking into account the dispersion and the longitudinal chromatic aberration (LCA) of the material of the lens, focusing of isodiffracting pulsed Gaussian light beam through single lens is analyzed. The smaller the cycle number of the isodiffracting pulsed Gaussian light beam is, the higher the order of the material dispersion should be considered

  9. Implementation of fluidized granulated iron reactors in a chromate remediation process

    International Nuclear Information System (INIS)

    Müller, P.; Lorber, K.E.; Mischitz, R.; Weiß, C.

    2014-01-01

    A new approach concerning in-situ remediation on source (‘hot-spot’) decontamination of a chromate damage in connection with an innovative pump-and-treat-technique has been developed. Iron granulates show significant higher reduction rates, using fluidized bed conditions, than a literature study with a fixed bed installation of small-sized iron granules. First results from an abandoned tannery site concerning injections of sodium dithionite as a chromate reductant for the vadose zone in combination with a pump-and-treat-method, allying the advantages of granulated zero valent iron (ZVI), are reported. Reduction amounts of chromate have been found up to 88% compared with initial values in the soil after a soil water exchange of 8 pore volumes within 2.5 months. Chromate concentrations in the pumped effluent have been reduced to under the detection limit of 0.005 mg/L by treatment with ZVI in the pilot plant. - Highlights: • Fe-granules show high Cr(VI)-reduction rates using fluidized bed conditions. • No respective negligible passivation effects on the surface of the iron granulates. • P and T-method by using ZVI in a FBR is very effective for Cr(VI) remediation. • The process provides no increase in salinity of the treated effluent

  10. Bäcklund transformation, analytic soliton solutions and numerical simulation for a (2+1)-dimensional complex Ginzburg-Landau equation in a nonlinear fiber

    Science.gov (United States)

    Yu, Ming-Xiao; Tian, Bo; Chai, Jun; Yin, Hui-Min; Du, Zhong

    2017-10-01

    In this paper, we investigate a nonlinear fiber described by a (2+1)-dimensional complex Ginzburg-Landau equation with the chromatic dispersion, optical filtering, nonlinear and linear gain. Bäcklund transformation in the bilinear form is constructed. With the modified bilinear method, analytic soliton solutions are obtained. For the soliton, the amplitude can decrease or increase when the absolute value of the nonlinear or linear gain is enlarged, and the width can be compressed or amplified when the absolute value of the chromatic dispersion or optical filtering is enhanced. We study the stability of the numerical solutions numerically by applying the increasing amplitude, embedding the white noise and adding the Gaussian pulse to the initial values based on the analytic solutions, which shows that the numerical solutions are stable, not influenced by the finite initial perturbations.

  11. Explicit Nonlinear Model Predictive Control Theory and Applications

    CERN Document Server

    Grancharova, Alexandra

    2012-01-01

    Nonlinear Model Predictive Control (NMPC) has become the accepted methodology to solve complex control problems related to process industries. The main motivation behind explicit NMPC is that an explicit state feedback law avoids the need for executing a numerical optimization algorithm in real time. The benefits of an explicit solution, in addition to the efficient on-line computations, include also verifiability of the implementation and the possibility to design embedded control systems with low software and hardware complexity. This book considers the multi-parametric Nonlinear Programming (mp-NLP) approaches to explicit approximate NMPC of constrained nonlinear systems, developed by the authors, as well as their applications to various NMPC problem formulations and several case studies. The following types of nonlinear systems are considered, resulting in different NMPC problem formulations: Ø  Nonlinear systems described by first-principles models and nonlinear systems described by black-box models; �...

  12. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models.

    Science.gov (United States)

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-11

    In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared. A Liou-Brennan-based IOL eye model was constructed using ZEMAX optical design software. Spherical IOLs with different diopters (AR40e, AMO Company, USA) were implanted; modulation transfer function (MTF) values at 3 mm of pupil diameter and from 0 to out-of-focus blur were collected and graphed. MTF values, measured at 555 nm of monochromatic light under each spatial frequency, were significantly higher than the values measured at 470 to 650 nm of polychromatic light. The influences of chromatic aberration on MTF values decreased with the increase in IOL diopter when the spatial frequency was ≤12 c/d, while increased effects were observed when the spatial frequency was ≥15 c/d. The MTF values of each IOL eye model were significantly lower than the MTF values of the Liou-Brennan eye models when measured at 555 nm of monochromatic light and at 470 to 650 nm of polychromatic light. The MTF values were also found to be increased with the increase in IOL diopter. With higher diopters of IOLs, the central thickness increased accordingly, which could have created increased chromatic aberration and decreased the retinal image quality. To improve the postoperative visual quality, IOLs with lower chromatic aberration should be selected for patients with short axial lengths.

  13. Chromatic detection from cone photoreceptors to V1 neurons to behavior in rhesus monkeys.

    Science.gov (United States)

    Hass, Charles A; Angueyra, Juan M; Lindbloom-Brown, Zachary; Rieke, Fred; Horwitz, Gregory D

    2015-01-01

    Chromatic sensitivity cannot exceed limits set by noise in the cone photoreceptors. To determine how close neurophysiological and psychophysical chromatic sensitivity come to these limits, we developed a parameter-free model of stimulus encoding in the cone outer segments, and we compared the sensitivity of the model to the psychophysical sensitivity of monkeys performing a detection task and to the sensitivity of individual V1 neurons. Modeled cones had a temporal impulse response and a noise power spectrum that were derived from in vitro recordings of macaque cones, and V1 recordings were made during performance of the detection task. The sensitivity of the simulated cone mosaic, the V1 neurons, and the monkeys were tightly yoked for low-spatiotemporal-frequency isoluminant modulations, indicating high-fidelity signal transmission for this class of stimuli. Under the conditions of our experiments and the assumptions for our model, the signal-to-noise ratio for these stimuli dropped by a factor of ∼3 between the cones and perception. Populations of weakly correlated V1 neurons narrowly exceeded the monkeys' chromatic sensitivity but fell well short of the cones' chromatic sensitivity, suggesting that most of the behavior-limiting noise lies between the cone outer segments and the output of V1. The sensitivity gap between the cones and behavior for achromatic stimuli was larger than for chromatic stimuli, indicating greater postreceptoral noise. The cone mosaic model provides a means to compare visual sensitivity across disparate stimuli and to identify sources of noise that limit visual sensitivity.

  14. 100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Mark D.; Vermeul, Vincent R.; Szecsody, James E.; Fruchter, Jonathan S.

    2000-10-12

    A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the 100 D Area of the U. S. Department of Energy's Hanford Site. The target contaminant was dissolved chromate in groundwater. The ISRM technology creates a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron to ferrous iron within the aquifer sediments, which is accomplished by injecting aqueous sodium dithionite into the aquifer and then withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in spring 1997; the first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998. The remaining four dithionite injections were carried out in May through July of 1998.These five injections created a reduced zone in the Hanford unconfined aquifer approximately 150 feet in length (perpendicular to groundwater flow) and 50 feet wide. The reduced zone extended over the thickness of the unconfined zone. Analysis of post-emplacement groundwater samples showed concentrations of chromate, in the reduced zone decreased from approximately 1.0 mg/L before the tests to below analytical detection limits (<0.007 mg/L). Chromate concentrations also declined in downgradient monitoring wells to as low as 0.020 mg/L. These data, in addition to results from pre-test reducible iron characterization, indicate the barrier should be effective for 20 to 25 years. The 100-D Area ISRM barrier is being expanded to a length of up to 2,300 ft to capture a larger portion of the chromate plume.

  15. Visual sensitivity for luminance and chromatic stimuli during the execution of smooth pursuit and saccadic eye movements.

    Science.gov (United States)

    Braun, Doris I; Schütz, Alexander C; Gegenfurtner, Karl R

    2017-07-01

    Visual sensitivity is dynamically modulated by eye movements. During saccadic eye movements, sensitivity is reduced selectively for low-spatial frequency luminance stimuli and largely unaffected for high-spatial frequency luminance and chromatic stimuli (Nature 371 (1994), 511-513). During smooth pursuit eye movements, sensitivity for low-spatial frequency luminance stimuli is moderately reduced while sensitivity for chromatic and high-spatial frequency luminance stimuli is even increased (Nature Neuroscience, 11 (2008), 1211-1216). Since these effects are at least partly of different polarity, we investigated the combined effects of saccades and smooth pursuit on visual sensitivity. For the time course of chromatic sensitivity, we found that detection rates increased slightly around pursuit onset. During saccades to static and moving targets, detection rates dropped briefly before the saccade and reached a minimum at saccade onset. This reduction of chromatic sensitivity was present whenever a saccade was executed and it was not modified by subsequent pursuit. We also measured contrast sensitivity for flashed high- and low-spatial frequency luminance and chromatic stimuli during saccades and pursuit. During saccades, the reduction of contrast sensitivity was strongest for low-spatial frequency luminance stimuli (about 90%). However, a significant reduction was also present for chromatic stimuli (about 58%). Chromatic sensitivity was increased during smooth pursuit (about 12%). These results suggest that the modulation of visual sensitivity during saccades and smooth pursuit is more complex than previously assumed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Accurate and fiducial-marker-free correction for three-dimensional chromatic shift in biological fluorescence microscopy.

    Science.gov (United States)

    Matsuda, Atsushi; Schermelleh, Lothar; Hirano, Yasuhiro; Haraguchi, Tokuko; Hiraoka, Yasushi

    2018-05-15

    Correction of chromatic shift is necessary for precise registration of multicolor fluorescence images of biological specimens. New emerging technologies in fluorescence microscopy with increasing spatial resolution and penetration depth have prompted the need for more accurate methods to correct chromatic aberration. However, the amount of chromatic shift of the region of interest in biological samples often deviates from the theoretical prediction because of unknown dispersion in the biological samples. To measure and correct chromatic shift in biological samples, we developed a quadrisection phase correlation approach to computationally calculate translation, rotation, and magnification from reference images. Furthermore, to account for local chromatic shifts, images are split into smaller elements, for which the phase correlation between channels is measured individually and corrected accordingly. We implemented this method in an easy-to-use open-source software package, called Chromagnon, that is able to correct shifts with a 3D accuracy of approximately 15 nm. Applying this software, we quantified the level of uncertainty in chromatic shift correction, depending on the imaging modality used, and for different existing calibration methods, along with the proposed one. Finally, we provide guidelines to choose the optimal chromatic shift registration method for any given situation.

  17. Chromatic dispersion effects in ultra-low coherence interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Lychagov, V V; Ryabukho, V P [N.G.Chernyshevsky Saratov State University (Russian Federation)

    2015-06-30

    We consider the properties of an interference signal shift from zero-path-difference position in the presence of an uncompensated dispersive layer in one of the interferometer arms. It is experimentally shown that in using an ultra-low coherence light source, the formation of the interference signal is also determined by the group velocity dispersion, which results in a nonlinear dependence of the position of the interference signal on the geometrical thickness of the dispersive layer. The discrepancy in the dispersive layer and compensator refractive indices in the third decimal place is experimentally shown to lead to an interference signal shift that is an order of magnitude greater than the pulse width. (interferometry)

  18. In the Jungle of Astronomical On--line Data Services

    Science.gov (United States)

    Egret, D.

    The author tried to survive in the jungle of astronomical on--line data services. In order to find efficient answers to common scientific data retrieval requests, he had to collect many pieces of information, in order to formulate typical user scenarios, and try them against a number of different data bases, catalogue services, or information systems. He discovered soon how frustrating treasure coffers may be when their keys are not available, but he realized also that nice widgets and gadgets are of no help when the information is not there. And, before long, he knew he would have to navigate through several systems because no one was yet offering a general answer to all his questions. I will present examples of common user scenarios and show how they were tested against a number of services. I will propose some elements of classification which should help the end-user to evaluate how adequate the different services may be for providing satisfying answers to specific queries. For that, many aspects of the user interaction will be considered: documentation, access, query formulation, functionalities, qualification of the data, overall efficiency, etc. I will also suggest possible improvements to the present situation: the first of them being to encourage system managers to increase collaboration between one another, for the benefit of the whole astronomical community. The subjective review I will present, is based on publicly available astronomical on--line services from the U.S. and from Europe, most of which (excepting the newcomers) were described in ``Databases and On-Line Data in Astronomy", (Albrecht & Egret, eds, 1991): this includes databases (such as NED and Simbad ), catalog services ( StarCat , DIRA , XCatScan , etc.), and information systems ( ADS and ESIS ).

  19. On-line implant reconstruction in HDR brachytherapy

    International Nuclear Information System (INIS)

    Kolkman-Deurloo, Inger-Karine K.; Kruijf, Wilhelmus J.M. de; Levendag, Peter C.

    2006-01-01

    Background and purpose: To evaluate the accuracy of on-line planning in an Integrated Brachytherapy Unit (IBU) using dedicated image distortion correction algorithms, correcting the geometric distortion and magnetic distortion separately, and to determine the effect of the reconstruction accuracy on clinical treatment plans in terms of deviations in treatment time and dose. Patients and methods: The reconstruction accuracy has been measured using 20 markers, positioned at well known locations in a QA phantom. Treatment plans of two phantoms representing clinical implant geometries, have been compared with reference plans to determine the effect of the reconstruction accuracy on the treatment plan. Before clinical introduction, treatment plans of three representative patients, based on on-line reconstruction, have been compared with reference plans. Results: The average reconstruction error for 10 in. images reduces from -0.6 mm (range -2.6 to +1.0 mm) to -0.2 mm (range -1.2 to +0.6 mm) after image distortion correction and for 15 in. images from 0.8 mm (range -0.5 to +3.0 mm) to 0.0 mm (range -0.8 to +0.8 mm). The error in case of eccentric positioning of the phantom, i.e. 0.8 mm (range -1.0 to +3.3 mm), reduces to 0.1 mm (range -0.5 to +0.9 mm). Correction of the image distortions reduces the deviation in the calculated treatment time of maximally 2.7% to less than 0.8% in case of eccentrically positioned clinical phantoms. The deviation in the treatment time or reference dose in the plans based on on-line reconstruction with image distortion correction of the three patient examples is smaller than 0.3%. Conclusions: Accurate on-line implant reconstruction using the IBU localiser and dedicated correction algorithms separating the geometric distortion and the magnetic distortion is possible. The results fulfill the minimum requirements as imposed by the Netherlands Commission on Radiation Dosimetry (NCS) without limitations regarding the usable range of the field

  20. On-line data processing for scintillation camera

    International Nuclear Information System (INIS)

    Ueyanagi, Hideo

    1974-01-01

    To process on-line the information from scintillation cameras, the computing/processing device of wired program type, with a specialized mini-computer for the processing, is generally used; and by this method, the data processing is done by the users of scintillation cameras. In the device with a mini-computer with processing programming by software, the almost all items in processing can be executed; but the operation requires some skill. With mini-computer operation, on the other hand, there are the problems of data-point number, process-time reduction, and image storage for both long and short terms. (Mori, K.)