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Sample records for shifting spectral position

  1. Mechanical spectral shift reactor

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1981-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drivemechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displayer rods through the reactor vessel

  2. Mechanical spectral shift reactor

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1982-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drive mechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displacer rods through the reactor vessel. (author)

  3. Mechanical spectral shift reactor

    Wilson, J.F.; Sherwood, D.G.

    1982-01-01

    A mechanical spectral shift reactor comprises a reactive core having fuel assemblies accommodating both water displacer elements and neutron absorbing control rods for selectively changing the volume of water-moderator in the core. The fuel assemblies with displacer and control rods are arranged in alternating fashion so that one displacer element drive mechanism may move displacer elements in more than one fuel assembly without interfering with the movement of control rods of a corresponding control rod drive mechanisms. (author)

  4. Mechanical spectral shift reactor

    Doshi, P.K.; George, R.A.; Dollard, W.J.

    1982-01-01

    A mechanical spectral shift arrangement for controlling a nuclear reactor includes a plurality of reactor coolant displacer members which are inserted into a reactor core at the beginning of the core life to reduce the volume of reactor coolant-moderator in the core at start-up. However, as the reactivity of the core declines with fuel depletion, selected displacer members are withdrawn from the core at selected time intervals to increase core moderation at a time when fuel reactivity is declining. (author)

  5. Spectral shift reactor

    Carlson, W.R.; Piplica, E.J.

    1982-01-01

    A spectral shift pressurized water reactor comprising apparatus for inserting and withdrawing water displacer elements having differing neutron absorbing capabilities for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The displacer elements comprise substantially hollow cylindrical low neutron absorbing rods and substantially hollow cylindrical thick walled stainless rods. Since the stainless steel displacer rods have greater neutron absorbing capability, they can effect greater reactivity change per rod. However, by arranging fewer stainless steel displacer rods in a cluster, the reactivity worth of the stainless steel displacer rod cluster can be less than a low neutron absorbing displacer rod cluster. (author)

  6. Variational study of spectral shifts. II

    Peton, A.

    1979-01-01

    In a static gravitational field the paths of light are curved. This property can be a priori stated for a V 3 Riemannian manifold: through any two points of V 3 it is possible to draw two families of curves, the straight lines of Euclidean geometry and the photon trajectories z. A fibration of the Galilean space-time can be performed in an original way, by taking the z-trajectories of the photons as the base, the isochronic surfaces as fibres, and 'the equal length time on a z trajectory to reach a given point' as the equivalence relation. The straight lines of Euclidean geometry can then carry the classical mechanics time t, and the z trajectories can carry the optics time (T). These times are related by d(T)=F(x,t)dt. If the Universe is classed as a pseudo-Riemannian manifold of normal hyperbolic type Csup(infinity), the time (T) determined above can be taken as the time coordinate in V 4 . Under these conditions d(S) 2 =F 2 ds 2 , where d(S) 2 is the metric of the Riemannian manifold, conforming to the metric ds 2 and allowing (T) as the cosmic time. The results previously achieved by the author (Peton, 1979) can be used to find 1+zsub(G)=F(Asub(s), tsub(s))/F(Asub(O),tsub(O)) where zsub(G) denotes the shift of the spectral lines due to the metric. In the case of relative motion between O and S, 1+z'=(1+zsub(G))(1+βsub(r))(1-β 2 )sup(-1/2)). The Doppler-Fizeau effect therefore appears as a result of the application of the Fermat principle. (Auth.)

  7. Perceptual Adaptation of Voice Gender Discrimination with Spectrally Shifted Vowels

    Li, Tianhao; Fu, Qian-Jie

    2011-01-01

    Purpose: To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Method: Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the…

  8. Spectral Shifting in Nondestructive Assay Instrumentation

    Trellue, Holly Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nettleton, Anthony Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tutt, James Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); LaFleur, Adrienne Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tobin, Stephen Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-17

    This project involves spectrum tailoring research that endeavors to better distinguish energies of gamma rays using different spectral material thicknesses and determine neutron energies by coating detectors with various materials.

  9. Integrated optics refractometry: sensitivity in relation to spectral shifts

    Hoekstra, Hugo; Hammer, M.

    2013-01-01

    A new variant of the Vernier-effect based sensor reported in ref. 1 is introduced. Both sensor types may show a huge index induced spectral shift. It will be shown in a poster presentation that with such sensors, as well as with surface plasmon based sensors, the constraints on the spectral

  10. Spectral stability of shifted states on star graphs

    Kairzhan, Adilbek; Pelinovsky, Dmitry E.

    2018-03-01

    We consider the nonlinear Schrödinger (NLS) equation with the subcritical power nonlinearity on a star graph consisting of N edges and a single vertex under generalized Kirchhoff boundary conditions. The stationary NLS equation may admit a family of solitary waves parameterized by a translational parameter, which we call the shifted states. The two main examples include (i) the star graph with even N under the classical Kirchhoff boundary conditions and (ii) the star graph with one incoming edge and N  -  1 outgoing edges under a single constraint on coefficients of the generalized Kirchhoff boundary conditions. We obtain the general counting results on the Morse index of the shifted states and apply them to the two examples. In the case of (i), we prove that the shifted states with even N ≥slant 4 are saddle points of the action functional which are spectrally unstable under the NLS flow. In the case of (ii), we prove that the shifted states with the monotone profiles in the N  -  1 edges are spectrally stable, whereas the shifted states with non-monotone profiles in the N  -  1 edges are spectrally unstable, the two families intersect at the half-soliton states which are spectrally stable but nonlinearly unstable under the NLS flow. Since the NLS equation on a star graph with shifted states can be reduced to the homogeneous NLS equation on an infinite line, the spectral instability of shifted states is due to the perturbations breaking this reduction. We give a simple argument suggesting that the spectrally stable shifted states in the case of (ii) are nonlinearly unstable under the NLS flow due to the perturbations breaking the reduction to the homogeneous NLS equation.

  11. Spectral shift rod for the boiling water reactor

    Yokomizo, O.; Kashiwai, S.; Nishida, K.; Orii, A.; Yamashita, J.; Mochida, T.

    1993-01-01

    A Boiling Water Reactor core concept has been proposed using a new fuel component called spectral shift rod (SSR). The SSR is a new type of water rod in which a water level is formed during core operation. The water level can be controlled by the core recirculation flow rate. By using SSRs, the reactor can be operated with all control rods withdrawn through the operation cycle as well as that a much larger natural uranium saving is possible due to spectral shift operation than in current BWRs. The steady state and transient characteristics of the SSRs have been examined by experiments and analyses to certify the feasibility. In a reference design, a four times larger spectral shift width as for the current BWR has been obtained. (orig.)

  12. Perceptual adaptation of voice gender discrimination with spectrally shifted vowels.

    Li, Tianhao; Fu, Qian-Jie

    2011-08-01

    To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the speech of 5 male and 5 female talkers with 16-channel sine-wave vocoders. The subjects were randomly divided into 2 groups; one subjected to 50-Hz, and the other to 200-Hz, temporal envelope cutoff frequencies. No preview or feedback was provided. There was significant adaptation in voice gender discrimination with the 200-Hz cutoff frequency, but significant improvement was observed only for 3 female talkers with F(0) > 180 Hz and 3 male talkers with F(0) gender discrimination under spectral shift conditions with perceptual adaptation, but spectral shift may limit the exclusive use of spectral information and/or the use of formant structure on voice gender discrimination. The results have implications for cochlear implant users and for understanding voice gender discrimination.

  13. Extension of Newton's Dynamical Spectral Shift for Photons in ...

    Extension of Newton's Dynamical Spectral Shift for Photons in Gravitational Fields of Static Homogeneous Spherical Massive Bodies. ... is perfectly in agreement with the physical fact that gravitational scalar potential is negative and increase in recession leads to decrease in kinetic energy and hence decrease in frequency.

  14. Ontogenetic shifts of heart position in snakes.

    Lillywhite, Harvey B; Lillywhite, Steven M

    2017-08-01

    Heart position relative to total body length (TL) varies among snakes, with anterior hearts in arboreal species and more centrally located hearts in aquatic or ground-dwelling species. Anterior hearts decrease the cardiac work associated with cranial blood flow and minimize drops in cranial pressure and flow during head-up climbing. Here, we investigate whether heart position shifts intraspecifically during ontogenetic increases in TL. Insular Florida cottonmouth snakes, Agkistrodon conanti, are entirely ground-dwelling and have a mean heart position that is 33.32% TL from the head. In contrast, arboreal rat snakes, Pantherophis obsoleta, of similar lengths have a mean heart position that is 17.35% TL from the head. In both species, relative heart position shifts craniad during ontogeny, with negative slopes = -.035 and -.021% TL/cm TL in Agkistrodon and Pantherophis, respectively. Using a large morphometric data set available for Agkistrodon (N = 192 individuals, 23-140 cm TL), we demonstrate there is an anterior ontogenetic shift of the heart position within the trunk (= 4.56% trunk length from base of head to cloacal vent), independent of head and tail allometry which are both negative. However, in longer snakes > 100 cm, the heart position reverses and shifts caudally in longer Agkistrodon but continues toward the head in longer individuals of Pantherophis. Examination of data sets for two independent lineages of fully marine snakes (Acrochordus granulatus and Hydrophis platurus), which do not naturally experience postural gravity stress, demonstrate both ontogenetic patterns for heart position that are seen in the terrestrial snakes. The anterior migration of the heart is greater in the terrestrial species, even if TL is standardized to that of the longer P. obsoleta, and compensates for about 5 mmHg gravitational pressure head if they are fully upright. © 2017 Wiley Periodicals, Inc.

  15. Spectral Envelope Transformation in Singing Voice for Advanced Pitch Shifting

    José L. Santacruz

    2016-11-01

    Full Text Available The aim of the present work is to perform a step towards more natural pitch shifting techniques in singing voice for its application in music production and entertainment systems. In this paper, we present an advanced method to achieve natural modifications when applying a pitch shifting process to singing voice by modifying the spectral envelope of the audio excerpt. To this end, an all-pole model has been selected to model the spectral envelope, which is estimated using a constrained non-linear optimization. The analysis of the global variations of the spectral envelope was carried out by identifying changes of the parameters of the model along with the changes of the pitch. With the obtained spectral envelope transformation functions, we applied our pitch shifting scheme to some sustained vowels in order to compare results with the same transformation made by using the Flex Pitch plugin of Logic Pro X and pitch synchronous overlap and add technique (PSOLA. This comparison has been carried out by means of both an objective and a subjective evaluation. The latter was done with a survey open to volunteers on our website.

  16. The slightly-enriched spectral shift control reactor

    Martin, W.R.; Lee, J.C.; Larsen, E.W. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering); Edlund, M.C. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical and Nuclear Engineering)

    1991-11-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile {sup 238}U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC.

  17. The slightly-enriched spectral shift control reactor

    Martin, W.R.; Lee, J.C.; Larsen, E.W.; Edlund, M.C.

    1991-11-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile 238 U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC

  18. Experience with the shift technical advisor position

    Melber, B.D.; Olson, J.; Schreiber, R.E.; Winges, L.

    1984-03-01

    The provision of engineering expertise on shift at commercial nuclear power plants has mainly taken the form of the Shift Technical Advisor (STA). This person, acting in a capacity that is part engineer and part operator, is expected to advise the operations crew in the event of an emergency and review plant operating experience during normal circumstances. The position was mandated by the Nuclear Regulatory Commission following the incident at Three Mile Island. This report expands on a growing body of knowledge regarding the effectiveness of the STA. The new data presented here come from interviews with plant personnel and utility officials from nine sites. Researchers from the Pacific Northwest Laboratory (PNL) interviewed plant personnel, including the STA and immediate management, the shift supervisor and management, the training department, and ancillary staff, all of whom affect the intended performance of the STA. The conclusions of the report are that the design of the STA position results in limited contribution during emergencies; more comprehensive ways should be sought to provide the variety and specificity of engineering expertise needed during such times

  19. Experience with the shift technical advisor position

    Melber, B.D.; Olson, J.; Schreiber, R.E.; Winges, L.

    1984-03-01

    The provision of engineering expertise on shift at commercial nuclear power plants has mainly taken the form of the Shift Technical Advisor (STA). This person, acting in a capacity that is part engineer and part operator, is expected to advise the operations crew in the event of an emergency and review plant operating experience during normal circumstances. The position was mandated by the Nuclear Regulatory Commission following the incident at Three Mile Island. This report expands on a growing body of knowledge regarding the effectiveness of the STA. The new data presented here come from interviews with plant personnel and utility officials from nine sites. Researchers from the Pacific Northwest Laboratory (PNL) interviewed plant personnel, including the STA and immediate management, the shift supervisor and management, the training department, and ancillary staff, all of whom affect the intended performance of the STA. The conclusions of the report are that the design of the STA position results in limited contribution during emergencies; more comprehensive ways should be sought to provide the variety and specificity of engineering expertise needed during such times.

  20. Spectral reconstruction for shifted-excitation Raman difference spectroscopy (SERDS).

    Guo, Shuxia; Chernavskaia, Olga; Popp, Jürgen; Bocklitz, Thomas

    2018-08-15

    Fluorescence emission is one of the major obstacles to apply Raman spectroscopy in biological investigations. It is usually several orders more intense than Raman scattering and hampers further analysis. In cases where the fluorescence emission is too intense to be efficiently removed via routine mathematical baseline correction algorithms, an alternative approach is needed. One alternative approach is shifted-excitation Raman difference spectroscopy (SERDS), where two Raman spectra are recorded with two slightly different excitation wavelengths. Ideally, the fluorescence emission at the two excitations does not change while the Raman spectrum shifts according to the excitation wavelength. Hence the fluorescence is removed in the difference of the two recorded Raman spectra. For better interpretability a spectral reconstruction procedure is necessary to recover the fluorescence-free Raman spectrum. This is challenging due to the intensity variations between the two recorded Raman spectra caused by unavoidable experimental changes as well as the presence of noise. Existent approaches suffer from drawbacks like spectral resolution loss, fluorescence residual, and artefacts. In this contribution, we proposed a reconstruction method based on non-negative least squares (NNLS), where the intensity variations between the two measurements are utilized in the reconstruction model. The method achieved fluorescence-free reconstruction on three real-world SERDS datasets without significant information loss. Thereafter, we quantified the performance of the reconstruction based on artificial datasets from four aspects: reconstructed spectral resolution, precision of reconstruction, signal-to-noise-ratio (SNR), and fluorescence residual. The artificial datasets were constructed with varied Raman to fluorescence intensity ratio (RFIR), SNR, full-width at half-maximum (FWHM), excitation wavelength shift, and fluorescence variation between the two spectra. It was demonstrated that

  1. Plutonium fuel cycles in the spectral shift controlled reactor

    Sider, F.M.; Matzie, R.A.

    1980-01-01

    The spectral shift controlled reactor (SSCR) controls excess core reactivity during an operating cycle through the use of variable heavy water concentrations in the moderator. With heavy water in the coolant, the neutron spectrum is shifted to higher energy levels, thus increasing fertile conversion. In addition, since heavy water obviates the need for soluble boron, neutron losses to control poison are eliminated. As a result, better resource utilization is obtained in the SSCR employing plutonium fuel cycles compared to similarly fueled pressurized water reactors (PWRs). The SSCR, however, is not competitive with the PWR due to higher capital costs, operation and maintenance costs, and the heavy water costs, which outweigh the fuel cycle cost savings. The SSCR may become an attractive alternative to the PWR if uranium prices increase substantially

  2. The slightly-enriched spectral shift control reactor

    Martin, W.R.; Lee, J.C.; Edlund, M.C.

    1990-06-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in larger neutron captures in fertile 238 U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 show that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies have been carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, effort will focus on performing the final design calculations and continuing the research to develop improved methods for tight lattice analysis

  3. Scheduling Aircraft Landings under Constrained Position Shifting

    Balakrishnan, Hamsa; Chandran, Bala

    2006-01-01

    Optimal scheduling of airport runway operations can play an important role in improving the safety and efficiency of the National Airspace System (NAS). Methods that compute the optimal landing sequence and landing times of aircraft must accommodate practical issues that affect the implementation of the schedule. One such practical consideration, known as Constrained Position Shifting (CPS), is the restriction that each aircraft must land within a pre-specified number of positions of its place in the First-Come-First-Served (FCFS) sequence. We consider the problem of scheduling landings of aircraft in a CPS environment in order to maximize runway throughput (minimize the completion time of the landing sequence), subject to operational constraints such as FAA-specified minimum inter-arrival spacing restrictions, precedence relationships among aircraft that arise either from airline preferences or air traffic control procedures that prevent overtaking, and time windows (representing possible control actions) during which each aircraft landing can occur. We present a Dynamic Programming-based approach that scales linearly in the number of aircraft, and describe our computational experience with a prototype implementation on realistic data for Denver International Airport.

  4. Nuclear fuel assembly with improved spectral shift-producing rods

    Ferrari, H.M.

    1987-01-01

    This patent describes a nuclear reactor having fuel assemblies and a moderator-coolant liquid flowing through the fuel assemblies, each fuel assembly including an organized array of nuclear fuel rods wherein the moderator-coolant liquid flows along the fuel rods, at least one improved spectral shift-producing rod disposed among the fuel rods. The spectra shift-producing rod consists of: (a) an elongated hollow hermetically-sealed tubular member; (b) a weakened region formed in a portion of the member, the portion being subject to rupture at a given level of internal pressure; and (c) burnable poison material contained in the member which generates gas in the member as operation of the reactor proceeds normally, the material being soluble in the moderator-coolant liquid when brought into contact therewith; (d) the given level of internal pressure being less than the maximum level of internal pressure normally expected to be generated within the member by the poison material by normal operation of the reactor

  5. Graphite-moderated and heavy water-moderated spectral shift controlled reactors

    Alcala Ruiz, F.

    1984-01-01

    It has been studied the physical mechanisms related with the spectral shift control method and their general positive effects on economical and non-proliferant aspects (extension of the fuel cycle length and low proliferation index). This methods has been extended to non-hydrogenous fuel cells of high moderator/fuel ratio: heavy water cells have been con- trolled by graphite rods graphite-moderated and gas-cooled cells have been controlled by berylium rods and graphite-moderated and water-cooled cells have been controlled by a changing mixture of heavy and light water. It has been carried out neutron and thermal analysis on a pre design of these types of fuel cells. We have studied its neutron optimization and their fuel cycles, temperature coefficients and proliferation indices. Finally, we have carried out a comparative analysis of the fuel cycles of conventionally controlled PWRs and graphite-moderated, water-cooled and spectral shift controlled reactors. (Author) 71 refs

  6. Conceptual design of a large Spectral Shift Controlled Reactor

    Matzie, R.A.; Menzel, G.P.

    1979-08-01

    Within the framework of the Nonproliferation Alternative Systems Assessment Program (NASAP), the US Department of Energy (DOE) has sponsored the development of a conceptual design of a large Spectral Shift Controlled Reactor (SSCR). This report describes the results of the development program and assesses the performance of the conceptual SSCR on the basis of fuel resource utilization and total power costs. The point of departure of the design study was a 1270 MW(e) PWR using Combustion Engineering's System 80/sup TM/ reactor and Stone and Webster's Reference Plant Design. The initial phase of the study consisted of establishing an optimal core design for both the once-through uranium cycle and the denatured U-235/thorium cycle with uranium recycle. The performance of the SSCR was then also assessed for the denatured U-233/thorium cycle with uranium recycle and for the plutonium/thorium cycle with plutonium recycle. After the optimal core design was established, the design of the NSSS and balance of plant was developed

  7. Conceptual design of a large Spectral Shift Controlled Reactor

    Matzie, R.A.; Menzel, G.P.

    1979-08-01

    Within the framework of the Nonproliferation Alternative Systems Assessment Program (NASAP), the US Department of Energy (DOE) has sponsored the development of a conceptual design of a large Spectral Shift Controlled Reactor (SSCR). The results are presented of the development program, and the performance of the conceptual SSCR is assessed on the basis of fuel resource utilization and total power costs. The point of departure of the design study was a 1270 MW(e) PWR using Combustion Engineering's System 80 reactor and Stone and Webster's Reference Plant Design. The initial phase of the study consisted of establishing an optimal core design for both the once-through uranium cycle and the denatured U-235/thorium cycle with uranium recycle. The performance of the SSCR was then also assessed for the denatured U-233/thorium cycle with uranium recycle and for the plutonium/thorium cycle with plutonium recycle. After the optimal core design was established, the design of the NSSS and balance of plant was developed

  8. Positional shifting of HRCT findings in patients with pulmonary edema

    Kim, Young Sun; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Seo, Heung Suk; Lee, Seung Rho; Hahm, Chang Kok

    2001-01-01

    To assess the value of positional shifting to a gravity-dependent area, as revealed by HRCT, in differentiating pulmonary edema (PE) from other conditions. Sixteen consecutive patients in whom plain radiographs suggested the presence of pulmonary edema but the clinical findings were indefinite underwent HRCT of the lung. For initial scanning they were in the supine position, and then in the prone position. Findings of ground-glass opacity, interlobular septal thickening and peribronchovascular interistitial thickening were analyzed in terms of the presence and degree of shifting to a gravity-dependent area, a grade of high, intermediate or low being assigned. PE was diagnosed in 8 of 16 cases, the remainder being designated as non-pulmonary edema (NPE). Ground-glass opacity was observed in all 16, while the degree of positional shifting was found to be high in ten (PE:NPE=6:4), intermediate in four (PE:NPE=2:2), and low in two (PE:NPE=0:2). There was no significant difference between the two groups (ρ > 0.05). Interlobular septal thickening was observed in all but two NPE cases; the degree of shifting was high in six (PE:NPE=6:0), intermediate in one (PE), and low in seven (PE:NPE=1:6). Shifting was significantly more prominent in PE than in NPE case (ρ <0.05). Peribronchovascular interstitial thickening was positive in all PE cases and one NPE case, with no positional shifting. Positional shifting of interlobular septal thickening to a gravity-dependent area, as demonstrated by HRCT, is the most specific indicator of pulmonary edema

  9. Fluorescence spectral shift of QD films with electron injection: Dependence on counterion proximity

    Lu, Meilin; Li, Bo; Zhang, Yaxin; Liu, Weilong; Yang, Yanqiang; Wang, Yuxiao; Yang, Qingxin

    2017-05-01

    Due to the promising application of quantum dot (QD) films in solar cells, LEDs and environmental detectors, the fluorescence of charged QD films has achieved much attention during recent years. In this work, we observe the spectral shift of photoluminescence (PL) in charged CdSe/ZnS QD films controlled by electrochemical potential. The spectral center under negative bias changes from red-shift to blue-shift while introducing smaller inorganic counterions (potassium ions) into the electrolyte. This repeatable effect is attributed to the enhanced electron injection with smaller cations and the electronic perturbations of QD luminescence by these excess charges.

  10. Transformation of Image Positions, Rotations, and Sizes into Shift Parameters

    Skov Jensen, A.; Lindvold, L.; Rasmussen, E.

    1987-01-01

    An optical image processing system is described that converts orientation and size to shift properties and simultaneously preserves the positional information as a shift. The system is described analytically and experimentally. The transformed image can be processed further with a classical...... correlator working with a rotational and size-invariant. multiplexed match filter. An optical robot vision system designed on this concept would be able to look at several objects simultaneously and determine their shape, size, orientation, and position with two measurements on the input scene at different...

  11. ABWR-II Core Design with Spectral Shift Rods for Operation with All Control Rods Withdrawn

    Moriwaki, Masanao; Aoyama, Motoo; Anegawa, Takafumi; Okada, Hiroyuki; Sakurada, Koichi; Tanabe, Akira

    2004-01-01

    An innovative reactor core concept applying spectral shift rods (SSRs) is proposed to improve the plant economy and the operability of the 1700-MW(electric) Advanced Boiling Water Reactor II (ABWR-II). The SSR is a new type of water rod in which a water level is naturally developed during operation and changed according to the coolant flow rate through the channel. By taking advantage of the large size of the ABWR-II bundle, the enhanced spectral shift operation by eight SSRs allows operation of the ABWR-II with all control rods withdrawn. In addition, the uranium-saving factor of 6 to 7% relative to the reference ABWR-II core with conventional water rods can be expected due to the greater effect of spectral shift. The combination of these advantages means the ABWR-II with SSRs should be an attractive alternative for the next-generation nuclear reactor

  12. Graphite-moderated and heavy water-moderated spectral shift controlled reactors; Reactores de moderador solido controlados por desplazamiento espectral

    Alcala Ruiz, F

    1984-07-01

    It has been studied the physical mechanisms related with the spectral shift control method and their general positive effects on economical and non-proliferant aspects (extension of the fuel cycle length and low proliferation index). This methods has been extended to non-hydrogenous fuel cells of high moderator/fuel ratio: heavy water cells have been con- trolled by graphite rods graphite-moderated and gas-cooled cells have been controlled by berylium rods and graphite-moderated and water-cooled cells have been controlled by a changing mixture of heavy and light water. It has been carried out neutron and thermal analysis on a pre design of these types of fuel cells. We have studied its neutron optimization and their fuel cycles, temperature coefficients and proliferation indices. Finally, we have carried out a comparative analysis of the fuel cycles of conventionally controlled PWRs and graphite-moderated, water-cooled and spectral shift controlled reactors. (Author) 71 refs.

  13. Ontogenetic shifts and spatial associations in organ positions for snakes.

    Anderson, Gretchen E; Secor, Stephen M

    2015-12-01

    Snakes possess an elongated body form and serial placement of organs which provides the opportunity to explore historic and adaptive mechanisms of organ position. We examined the influence of body size and sex on the position of, and spatial associations between, the heart, liver, small intestine, and right kidney for ten phylogenetically diverse species of snakes that vary in body shape and habitat. Snake snout-vent length explained much of the variation in the position of these four organs. For all ten species, the position of the heart and liver relative to snout-vent length decreased as a function of size. As body size increased from neonate to adult, these two organs shifted anteriorly an average of 4.7% and 5.7% of snout-vent length, respectively. Similarly, the small intestine and right kidney shifted anteriorly with an increase in snout-vent length for seven and five of the species, respectively. The absolute and relative positioning of these organs did not differ between male and female Burmese pythons (Python molurus). However, for diamondback water snakes (Nerodia rhombifer), the liver and small intestine were more anteriorly positioned in females as compared to males, whereas the right kidney was positioned more anteriorly for males. Correlations of residuals of organ position (deviation from predicted position) demonstrated significant spatial associations between organs for nine of the ten species. For seven species, individuals with hearts more anterior (or posterior) than predicted also tended to possess livers that were similarly anteriorly (or posteriorly) placed. Positive associations between liver and small intestine positions and between small intestine and right kidney positions were observed for six species, while spatial associations between the heart and small intestine, heart and right kidney, and liver and right kidney were observed in three or four species. This study demonstrates that size, sex, and spatial associations may have

  14. Stark shift measurements of Xe II and Xe III spectral lines

    Cirisan, M; Pelaez, R J; Djurovic, S; Aparicio, J A; Mar, S

    2007-01-01

    Stark shift measurements of singly and doubly ionized Xe spectral lines are presented in this paper. Shifts of 110 Xe II lines and 42 Xe III lines are reported, including a significant number of new results. A low-pressure-pulsed arc with 95% of He and 5% of Xe was used as a plasma source. All measurements were performed under the following plasma conditions: electron density (0.2-1.4) x 10 23 m -3 and electron temperature 18 000-23 000 K. The measured Stark shifts are compared with other experimental and theoretical data

  15. Neutronics equations: Positiveness; compactness; spectral theory; time asymptotic behavior

    Mokhtar-Kharroubi, M.

    1987-12-01

    Neutronics equations are studied: the continuous model (with and without delayed neutrons) and the multigroup model. Asymptotic descriptions of these equations (t→+∞) are obtained, either by the Dunford method or by using semigroup perturbation techniques, after deriving the spectral theory for the equations. Compactness problems are reviewed, and a general theory of compact injection in neutronic functional space is derived. The effects of positiveness in neutronics are analyzed: the irreducibility of the transport semigroup, and the properties of the main eigenvalue (existence, nonexistence, frame, strict dominance, strict monotony in relation to all the parameters). A class of transport operators whose real spectrum can be completely described is shown [fr

  16. Impact of Vertical Canopy Position on Leaf Spectral Properties and Traits across Multiple Species

    Tawanda W. Gara

    2018-02-01

    Full Text Available Understanding the vertical pattern of leaf traits across plant canopies provide critical information on plant physiology, ecosystem functioning and structure and vegetation response to climate change. However, the impact of vertical canopy position on leaf spectral properties and subsequently leaf traits across the entire spectrum for multiple species is poorly understood. In this study, we examined the ability of leaf optical properties to track variability in leaf traits across the vertical canopy profile using Partial Least Square Discriminatory Analysis (PLS-DA. Leaf spectral measurements together with leaf traits (nitrogen, carbon, chlorophyll, equivalent water thickness and specific leaf area were studied at three vertical canopy positions along the plant stem: lower, middle and upper. We observed that foliar nitrogen (N, chlorophyll (Cab, carbon (C, and equivalent water thickness (EWT were higher in the upper canopy leaves compared with lower shaded leaves, while specific leaf area (SLA increased from upper to lower canopy leaves. We found that leaf spectral reflectance significantly (P ≤ 0.05 shifted to longer wavelengths in the ‘red edge’ spectrum (685–701 nm in the order of lower > middle > upper for the pooled dataset. We report that spectral bands that are influential in the discrimination of leaf samples into the three groups of canopy position, based on the PLS-DA variable importance projection (VIP score, match with wavelength regions of foliar traits observed to vary across the canopy vertical profile. This observation demonstrated that both leaf traits and leaf reflectance co-vary across the vertical canopy profile in multiple species. We conclude that canopy vertical position has a significant impact on leaf spectral properties of an individual plant’s traits, and this finding holds for multiple species. These findings have important implications on field sampling protocols, upscaling leaf traits to canopy level

  17. Perturbation method utilization in the analysis of the Convertible Spectral Shift Reactor (RCVS)

    Bruna, G.B; Legendre, J.F.; Porta, J.; Doriath, J.Y.

    1988-01-01

    In the framework of the preliminary faisability studies on a new core concept, techniques derived from perturbation theory show-up very useful in the calculation and physical analysis of project parameters. We show, in the present work, some applications of these methods to the RCVS (Reacteur Convertible a Variation de Spectre - Convertible Spectral Shift Reactor) Concept studies. Actually, we present here the search of a few group project type energy structure and the splitting of reactivity effects into individual components [fr

  18. The slightly-enriched spectral shift control reactor. Final report, September 30, 1988--September 30, 1991

    Martin, W.R.; Lee, J.C.; Larsen, E.W. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering; Edlund, M.C. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical and Nuclear Engineering

    1991-11-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile {sup 238}U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC.

  19. Complementary shifts in photoreceptor spectral tuning unlock the full adaptive potential of ultraviolet vision in birds.

    Toomey, Matthew B; Lind, Olle; Frederiksen, Rikard; Curley, Robert W; Riedl, Ken M; Wilby, David; Schwartz, Steven J; Witt, Christopher C; Harrison, Earl H; Roberts, Nicholas W; Vorobyev, Misha; McGraw, Kevin J; Cornwall, M Carter; Kelber, Almut; Corbo, Joseph C

    2016-07-12

    Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11’,12’-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination.

  20. Spectral phase shift and residual angular dispersion of an accousto-optic programme dispersive filter

    Boerzsoenyi, A.; Meroe, M.

    2010-01-01

    Complete text of publication follows. There is an increasing demand for active and precise dispersion control of ultrashort laser pulses. In chirped pulse amplification (CPA) laser systems, the dispersion of the optical elements of the laser has to be compensated at least to the fourth order to obtain high temporal contrast compressed pulses. Nowadays the most convenient device for active and programmable control of spectral phase and amplitude of broadband laser pulses is the acousto-optic programmable dispersive filter (AOPDF), claimed to be able to adjust the spectral phase up to the fourth order. Although it has been widely used, surprisingly enough there has been only a single, low resolution measurement reported on the accuracy of the induced spectral phase shift of the device. In our paper we report on the first systematic experiment aiming at the precise characterization of an AOPDF device. In the experiment the spectral phase shift of the AOPDF device was measured by spectrally and spatially resolved interferometry, which is especially powerful tool to determine small dispersion values with high accuracy. Besides the spectral phase dispersion, we measured both the propagation direction angular dispersion (PDAD) and the phase front angular dispersion (PhFAD). Although the two quantities are equal for plane waves, there may be noticeable difference for Gaussian pulses. PDAD was determined simply by focusing the beam on the slit of an imaging spectrograph, while PhFAD was measured by the use of an inverted Mach-Zehnder interferometer and an imaging spectrograph. In the measurements, the spectral phase shift and both types of angular dispersion have been recorded upon the systematic change of all the accessible functions of the acousto-optic programmable dispersive filter. The measured values of group delay dispersion (GDD) and third order dispersion (TOD) have been found to agree with the preset values within the error of the measurement (1 fs 2 and 10 fs 3

  1. Statistical learning of music- and language-like sequences and tolerance for spectral shifts.

    Daikoku, Tatsuya; Yatomi, Yutaka; Yumoto, Masato

    2015-02-01

    In our previous study (Daikoku, Yatomi, & Yumoto, 2014), we demonstrated that the N1m response could be a marker for the statistical learning process of pitch sequence, in which each tone was ordered by a Markov stochastic model. The aim of the present study was to investigate how the statistical learning of music- and language-like auditory sequences is reflected in the N1m responses based on the assumption that both language and music share domain generality. By using vowel sounds generated by a formant synthesizer, we devised music- and language-like auditory sequences in which higher-ordered transitional rules were embedded according to a Markov stochastic model by controlling fundamental (F0) and/or formant frequencies (F1-F2). In each sequence, F0 and/or F1-F2 were spectrally shifted in the last one-third of the tone sequence. Neuromagnetic responses to the tone sequences were recorded from 14 right-handed normal volunteers. In the music- and language-like sequences with pitch change, the N1m responses to the tones that appeared with higher transitional probability were significantly decreased compared with the responses to the tones that appeared with lower transitional probability within the first two-thirds of each sequence. Moreover, the amplitude difference was even retained within the last one-third of the sequence after the spectral shifts. However, in the language-like sequence without pitch change, no significant difference could be detected. The pitch change may facilitate the statistical learning in language and music. Statistically acquired knowledge may be appropriated to process altered auditory sequences with spectral shifts. The relative processing of spectral sequences may be a domain-general auditory mechanism that is innate to humans. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The effect of spectral width on Goos–Hanchen and Imbert–Fedorov shifts

    Prajapati, Chandravati; Ranganathan, D

    2013-01-01

    We study the Goos–Hanchen and Imbert–Fedorov shifts for quasi-monochromatic Gaussian beams near the Brewster angle, when the reflection is from a denser to a rarer medium. This is the case of interest in the usual experiments on reflectometry, etc. We have incorporated the effects of the finite linewidth of the quasi-monochromatic light and treated the cases of a Lorentzian and a Gaussian lineshape of the input light spectrum. This study of light with a finite spectral width was carried out for the more frequently studied case, namely reflection from a dense to a rare medium. We found that the shift is increased as compared to the monochromatic Gaussian beam, and is zero at the Brewster angle for a p polarized beam. The shift variation with angle of incidence near the Brewster and critical angles at different values of refractive index ratios is found. We also studied the shift variation for Hermite–Gauss beams around the Brewster angle when the reflection is from a rarer to a denser medium and compare this with our earlier results for the case when the reflection was from a denser to a rarer medium. (paper)

  3. Frequency position modulation using multi-spectral projections

    Goodman, Joel; Bertoncini, Crystal; Moore, Michael; Nousain, Bryan; Cowart, Gregory

    2012-10-01

    In this paper we present an approach to harness multi-spectral projections (MSPs) to carefully shape and locate tones in the spectrum, enabling a new and robust modulation in which a signal's discrete frequency support is used to represent symbols. This method, called Frequency Position Modulation (FPM), is an innovative extension to MT-FSK and OFDM and can be non-uniformly spread over many GHz of instantaneous bandwidth (IBW), resulting in a communications system that is difficult to intercept and jam. The FPM symbols are recovered using adaptive projections that in part employ an analog polynomial nonlinearity paired with an analog-to-digital converter (ADC) sampling at a rate at that is only a fraction of the IBW of the signal. MSPs also facilitate using commercial of-the-shelf (COTS) ADCs with uniform-sampling, standing in sharp contrast to random linear projections by random sampling, which requires a full Nyquist rate sample-and-hold. Our novel communication system concept provides an order of magnitude improvement in processing gain over conventional LPI/LPD communications (e.g., FH- or DS-CDMA) and facilitates the ability to operate in interference laden environments where conventional compressed sensing receivers would fail. We quantitatively analyze the bit error rate (BER) and processing gain (PG) for a maximum likelihood based FPM demodulator and demonstrate its performance in interference laden conditions.

  4. A differential detection scheme of spectral shifts in long-period fiber gratings

    Zhelyazkova, Katerina; Eftimov, Tinko; Smietana, Mateusz; Bock, Wojtek

    2010-10-01

    In this work we present an analysis of the response of a compact, simple and inexpensive optoelectronic sensor system intended to detect spectral shifts of a long-period fiber grating (LPG). The system makes use of a diffraction grating and a couple of receiving optical fibers that pick up signals at two different wavelengths. This differential detection system provides the same useful information from an LPG-based sensor as with a conventional laboratory system using optical spectrum analyzers for monitoring the minimum offset of LPG. The design of the fiber detection pair as a function of the parameters of the dispersion grating, the pick-up fiber and the LPG parameters, is presented in detail. Simulation of the detection system responses is presented using real from spectral shifts in nano-coated LPGs caused by the evaporation of various liquids such as water, ethanol and acetone, which are examples of corrosive, flammable and hazardous substances. Fiber optic sensors with similar detection can find applications in structural health monitoring for moisture detection, monitoring the spillage of toxic and flammable substances in industry etc.

  5. Nonlocal electron kinetics and spectral line emission in the positive column of an argon glow discharge

    Golubovskii, Yu; Kalanov, D; Gorchakov, S; Uhrlandt, D

    2015-01-01

    Modern non-local electron kinetics theory predicts several interesting effects connected with spectral line emission from the positive column in the range of low and medium pressures and currents. Some theoretical works describe non-monotonic behavior of the radial profiles of line emission at intermediate pressures and currents between the validity ranges of the non-local and local approximation of the electron kinetics. Despite a great number of publications, there have been no systematic measurements attempting to confirm these theoretical predictions through experiments. In this work the radial profiles of the line emission from the positive column of an argon glow discharge have been measured with high spatial resolution and new effects caused by the narrowing and broadening of the spatial emission profiles with dependence on discharge conditions have been discovered. The effect of intensity maximum shift predicted by theory using a self-consistent model was not found in the experiment. The properties of the spectral line radiation are influenced by the peculiarities of the formation of the high-energy tail of the electron energy distribution function. An interpretation of the observed effects based on the non-local character of the electron kinetics in radially inhomogeneous fields is given. The obtained experimental data are compared with the results of calculations. (paper)

  6. Optimization of the fuel cell of a spectral shift controlled reactor

    Alcala, F.

    1984-01-01

    Some low enriched uranium-graphite watercooled cells are analyzed from the point of view of both neutronic and thermal behavior. Such cells are of greater interest if their reactivity control is carried out by means of spectral shifting. This may be achieved by changing the relative concentration of a mixture of heavy and light water used as a coolant that flows through a system of tubes arranged in the graphite blocks. The increase of the relative fraction of light water during the burnup cycle extends the length of the cycle and makes it less proliferative. Performance of a cell of this kind is compared with that of a typical pressurized water reactor cell having the same type of fuel, degree of enrichment, specific power, and total power output

  7. Power shifts track serial position and modulate encoding in human episodic memory.

    Serruya, Mijail D; Sederberg, Per B; Kahana, Michael J

    2014-02-01

    The first events in a series exert a powerful influence on cognition and behavior in both humans and animals. This is known as the law of primacy. Here, we analyze the neural correlates of primacy in humans by analyzing electrocorticographic recordings in 84 neurosurgical patients as they studied and subsequently recalled lists of common words. We found that spectral power in the gamma frequency band (28-100 Hz) was elevated at the start of the list and gradually subsided, whereas lower frequency (2-8 Hz) delta and theta band power exhibited the opposite trend. This gradual shift in the power spectrum was found across a widespread network of brain regions. The degree to which the subsequent memory effect was modulated by list (serial) position was most pronounced in medial temporal lobe structures. These results suggest that globally increased gamma and decreased delta-theta spectral powers reflect a brain state that predisposes medial temporal lobe structures to enhance the encoding and maintenance of early list items.

  8. Improving fuel utilization in SmAHTR with spectral shift control design: Proof of concept

    Kotlyar, D.; Lindley, B.A.; Mohamed, H.

    2017-01-01

    Highlights: • Improving the fuel utilization in a graphite moderated reactor by adopting the ‘spectral shift’ concept. • The feasibility of this concept was tested in the Small Advanced High-Temperature Reactor. • At BOL, the reactor is under-moderated, with excess neutrons being primarily breeding 239 Pu. • Graphite is continuously inserted thermalizing the neutron spectrum and increasing reactivity. • The extra 239 Pu bred during the cycle is then burned, allowing the cycle to be extended. - Abstract: This paper presents a spectral shift design based approach to improve the fuel utilization factor or alternatively to increase the cycle length in a graphite moderated reactor. The feasibility of this concept was tested in the Small Advanced High-Temperature Reactor (SmAHTR). This is a small sized Fluoride-salt-cooled high-temperature reactor (FHR) that uses tri-isotropic (TRISO)-coated particle fuels and graphite moderator materials. A major benefit of the TRISO particles is the ability to mitigate fission product release in the case of an accident. However, the fabrication costs associated with TRISO particles are expected to be significantly higher than the traditional UO 2 fuel. The preliminary studies presented in the paper are focused on extending the achievable irradiation period without increasing the value of the enrichment. In order to increase the discharge burnup, the design includes graphite structures that are initially removed from the core. This imposes a harder spectrum, which enhances the breeding of 239 Pu. Then, the graphite structures are gradually and continuously inserted into the core to sustain criticality. This procedure shifts the hard spectrum into a more thermal one and enables a more efficient utilization of 239 Pu. The preliminary results indicate that this design achieves considerably longer irradiation periods and hence lower fuel cycle costs than the reference design.

  9. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  10. Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings.

    Ferrero, Alejandro; Rabal, Ana; Campos, Joaquín; Martínez-Verdú, Francisco; Chorro, Elísabet; Perales, Esther; Pons, Alicia; Hernanz, María Luisa

    2013-02-01

    A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.

  11. Positive attitudinal shifts with the Physics by Inquiry curriculum across multiple implementations

    Beth A. Lindsey

    2012-01-01

    Full Text Available Recent publications have documented positive attitudinal shifts on the Colorado Learning Attitudes about Science Survey (CLASS among students enrolled in courses with an explicit epistemological focus. We now report positive attitudinal shifts in classes using the Physics by Inquiry (PbI curriculum, which has only an implicit focus on student epistemologies and nature of science issues. These positive shifts have occurred in several different implementations of the curriculum, across multiple institutions and multiple semesters. In many classes, students experienced significant attitudinal shifts in the problem-solving categories of the CLASS, despite the conceptual focus of most PbI courses.

  12. Apparent wavelength shifts of H-like ions caused by the spectral fine structure observed in CHS plasmas

    Nishimura, Shin; Ida, Katsumi

    1998-01-01

    A new charge exchange spectroscopy (CXS) system viewing the plasma from the upside and the downside simultaneously was installed on the Compact Helical System (CHS) to detect the absolute value of Doppler shift due to poloidal rotation velocity ( i ∼ 100 eV) and in the after-glow recombining phase (T i ∼ 30 eV). The apparent Doppler shift is always red-shift regardless the direction of plasma rotation and is explained as the effect of the spectral fine structure of hydrogen-like ions. (author)

  13. Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

    Caraveo-Frescas, J. A.; Hedhili, Mohamed N.; Wang, H.; Schwingenschlö gl, Udo; Alshareef, Husam N.

    2012-01-01

    measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which

  14. Evaluation of spectral shift controlled reactors operating on the uranium fuel cycle. Final report

    Matzie, R.A.; Sider, F.M.

    1979-08-01

    The performance of the spectral shift controlled reactor (SSCR) operating on uranium fuel cycles was evaluated and compared with the conventional pressurized water reactor (PWR). In order to analyze the SSCR, the PSR design methodology was extended to include systems moderated by mixtures of light water and heavy water and these methods were validated by comparison with experimental results. Once the design methods had been formulated, the resouce requirements and power costs were determined for the uranium-fueled SSCR. The ore requirements of the UO 2 once-through fuel cycle and the UO 2 fuel cycle with self-generated recycle (SGR) of plutonium were found to be 10% and 19% less than those of similarly fueled PWRs, respectively. A fuel cycle optimization study was performed for the UO 2 once-through SSCR and the SGR SSCR. By individually altering lattice parameters, discharge exposure or number of in-core batches, savings of less than 8% in resource requirements and less than 1% in power costs were obtained

  15. Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

    Colas, Florent; Cottat, Maximilien; Gillibert, Raymond; Guillot, Nicolas; Djaker, Nadia; Lidgi-Guigui, Nathalie; Toury, Timothé e; Barchiesi, Dominique; Toma, Andrea; Di Fabrizio, Enzo M.; Gucciardi, Pietro Giuseppe; de la Chapelle, Marc Lamy

    2016-01-01

    Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

  16. Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

    Colas, Florent

    2016-06-06

    Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

  17. IRPHE/B and W-SS-LATTICE, Spectral Shift Reactor Lattice Experiments

    2003-01-01

    Description: B and W has performed and analysed a series of physics experiments basically concerned with the technology of heterogeneous reactors moderated and cooled by a variable mixture of heavy and light water. A reactor so moderated is termed Spectral Shift Control Reactor (S SCR). In the practical application of this concept, the moderator mixture is rich in heavy water at the beginning of core life, so a relatively large fraction of the neutrons are epithermal and are absorbed in the fertile material. As fuel is consumed, the moderator is diluted with light water. In this way the neutron spectrum is shifted, thereby increasing the proportion of thermal neutrons and the reactivity of the system. The general objective of the S SCR Basic Physics Program was to study the nuclear properties of rod lattices moderated by D 2 O-H 2 O mixtures. The volume ratio of moderator to non-moderator in all lattices was approximately 1.0, and the fuel was either 4%-enriched UO 2 clad in stainless steel or 93%-enriched UO 2 -ThO 2 (Nth/N 15) pellets clad in aluminum. The D 2 O concentration in the moderator ranged from zero to about 90 mole %. The experimental program includes critical experiments with both types of fuel, exponential experiments at room temperature with both types of fuel, exponential experiments at elevated temperatures with the 4%-enriched UO 2 fuel, and neutron age measurements in ThO 2 lattices. The theoretical program included the development of calculation methods applicable to these systems, and the analysis and correlation of the experimental data. A first report provides the results of critical experiments performed under the Spectral Shift Control Reactor Basic Physics Program. A second report documents experimental results and theoretical interpretation of a series of twenty uniform lattice critical experiments in which the neutron spectrum is varied over a fairly broad range. A third report addresses issues that bear on the problems associated with

  18. Spectral nudging to eliminate the effects of domain position and geometry in regional climate model simulations

    Miguez-Macho, Gonzalo; Stenchikov, Georgiy L.; Robock, Alan

    2004-07-01

    It is well known that regional climate simulations are sensitive to the size and position of the domain chosen for calculations. Here we study the physical mechanisms of this sensitivity. We conducted simulations with the Regional Atmospheric Modeling System (RAMS) for June 2000 over North America at 50 km horizontal resolution using a 7500 km × 5400 km grid and NCEP/NCAR reanalysis as boundary conditions. The position of the domain was displaced in several directions, always maintaining the U.S. in the interior, out of the buffer zone along the lateral boundaries. Circulation biases developed a large scale structure, organized by the Rocky Mountains, resulting from a systematic shifting of the synoptic wave trains that crossed the domain. The distortion of the large-scale circulation was produced by interaction of the modeled flow with the lateral boundaries of the nested domain and varied when the position of the grid was altered. This changed the large-scale environment among the different simulations and translated into diverse conditions for the development of the mesoscale processes that produce most of precipitation for the Great Plains in the summer season. As a consequence, precipitation results varied, sometimes greatly, among the experiments with the different grid positions. To eliminate the dependence of results on the position of the domain, we used spectral nudging of waves longer than 2500 km above the boundary layer. Moisture was not nudged at any level. This constrained the synoptic scales to follow reanalysis while allowing the model to develop the small-scale dynamics responsible for the rainfall. Nudging of the large scales successfully eliminated the variation of precipitation results when the grid was moved. We suggest that this technique is necessary for all downscaling studies with regional models with domain sizes of a few thousand kilometers and larger embedded in global models.

  19. Measurement of the spectral shift of the 3d→4p transitions in Ar+, Cl+ and S+ by means of collinear fast-beam laser spectroscopy

    Eichhorn, A.

    1981-01-01

    The spectral shift of the 3d→4p transitions in Ar + ( 36 Ar + and 40 Ar + ) Cl + ( 35 Cl + and 37 Cl + ) and S + ( 32 S + + 34 S + ) were measured by means of collinear fast-beam laser spectroscopy. Since the volume effect is neglectible only the normal and specific mass effect give contributions to the spectral shift. (BEF)

  20. Nuclear power plant shift technical advisor. Recommendations for position description, qualifications, education and training

    1981-01-01

    The purpose of this document is to describe the position and identify specific areas of formal education, plant-specific training and experience necessary to assure an advanced level of analytical ability on shift. These recommendations will provide a level of technical ability that is essential to improved operational safety and are consistent with regulatory requirements. This position was developed in conjunction with representatives of utilities, equipment vendors and engineering educators, giving consideration to specific contributions the function must make to shift operations

  1. Large Positive and Negative Lateral Shifts from an Anisotropic Metamaterial Slab Backed by a Metal

    Min, Cheng; Rong, Chen

    2009-01-01

    The lateral shift of a light beam at the surface of an anisotropic metamaterial (AMM) slab backed by a metal is investigated. Analytical expressions of the lateral shifts are derived using the stationary-phase method, in the case that total refection does and does not occur at the first interface. The sign of the lateral shift in two situations is discussed, and the necessary conditions for the lateral shift to be positive or negative are given. It is shown that the thickness and physical parameters of the AMM slab and the incident angle of the light beam strongly affect the properties of the lateral shift. Numerical results validate these conclusions. The lossy effect of the metamaterial on the lateral shift is also investigated

  2. Using AVIRIS for in-flight calibration of the spectral shifts of SPOT-HRV and of AVHRR?

    Willart-Soufflet, Veronique; Santer, Richard

    1993-01-01

    The response of a satellite sensor varies during its lifetime; internal calibration devices can be used to follow the sensor degradation or in-flight calibrations are conducted from estimates of the radiance at satellite level for well predictable situations. Changes in gain are evaluated assuming that the spectral response of the sensor is stable with time; i.e., that the filter response as well as the optics or the electronics are not modified since the prelaunch determinations. Nevertheless, there is some evidence that the SPOT interferometer filters are affected by outgassing effects during the launch. Tests in vacuum chambers indicated a narrowing of the filters with a shift of the upper side towards the blue of about 10 nm which is more over consistant with the loss of gain observed during the launch. Also, during the lifetime of SPOT, the relationship between the loss of sensitivity and the filter bandwidth may correspond to this effect. On the other hand, the inconsistancy of the NOAA7 calibration between two methods (desert and ocean) having a different spectral sensitivity may indicate a spectral problem with a shift of the central wavelength of -20 nm. The basic idea here is to take advantage of the good spectral definition of AVIRIS to monitor these potential spectral degradations with an experimental opportunity provided by a field campaign held in La Crau (S.E. of France) in June 1991 which associated ground-based measurements and AVIRIS, SPOT2, NOAA-11 overpasses over both the calibration site of La Crau and an agricultural area.

  3. The impact of shifting vantage perspective when recalling and imagining positive events.

    Vella, Nicholas C; Moulds, Michelle L

    2014-01-01

    The vantage perspective from which memories are recalled influences their emotional impact. To date, however, the impact of vantage perspective on the emotions elicited by positive memories and images of positive future events has been minimally explored. We experimentally manipulated the vantage perspective from which a sample of undergraduate students (n =80) recalled positive memories and imagined positive future events. Participants who naturally recalled their positive memories from a field perspective reported decreased vividness and positive affect (i.e., happiness, optimism, hopefulness) when they were instructed to shift to an observer perspective. The same pattern of emotionality ratings was observed when participants' vantage perspective of imagined future events was manipulated. In contrast, shifting participants from observer to field perspective recall of positive memories did not result in changes in ratings of memory-related emotion, although we found an unexpected trend towards reduced vividness. For positive future events, shifting from an observer to a field perspective resulted in decreased vividness but did not lead to any changes in positive emotion. Our findings confirm that vantage perspective plays a key role in determining the emotional impact of positive memories, and demonstrate that this relationship is also evident for images of future positive events.

  4. Development of new two-dimensional spectral/spatial code based on dynamic cyclic shift code for OCDMA system

    Jellali, Nabiha; Najjar, Monia; Ferchichi, Moez; Rezig, Houria

    2017-07-01

    In this paper, a new two-dimensional spectral/spatial codes family, named two dimensional dynamic cyclic shift codes (2D-DCS) is introduced. The 2D-DCS codes are derived from the dynamic cyclic shift code for the spectral and spatial coding. The proposed system can fully eliminate the multiple access interference (MAI) by using the MAI cancellation property. The effect of shot noise, phase-induced intensity noise and thermal noise are used to analyze the code performance. In comparison with existing two dimensional (2D) codes, such as 2D perfect difference (2D-PD), 2D Extended Enhanced Double Weight (2D-Extended-EDW) and 2D hybrid (2D-FCC/MDW) codes, the numerical results show that our proposed codes have the best performance. By keeping the same code length and increasing the spatial code, the performance of our 2D-DCS system is enhanced: it provides higher data rates while using lower transmitted power and a smaller spectral width.

  5. Body position-dependent shift in odor percept present only for perithreshold odors.

    Lundström, Johan N; Boyle, Julie A; Jones-Gotman, Marilyn

    2008-01-01

    We recently demonstrated that a supine position causes a decrease in olfactory sensitivity compared with an upright position. We pursued that initial finding in 3 separate experiments in which we explored the extent of, and mechanism underlying, this phenomenon. In Experiment 1, we replicated the decrease in olfactory sensitivity when in a supine compared with an upright position. In Experiment 2, we measured body position-dependent shifts in physiological variables and sniff measures while smelling suprathreshold odorants and performing a perithreshold odor intensity discrimination task. Olfactory performances were reduced while supine. However, no relationships between the shift in olfactory performances and either the physiological variables or sniff measures were found. In Experiment 3, we determined that there were no position-dependent shifts in ability to discriminate or identify suprathreshold odors or rate them for pleasantness, intensity, or familiarity. However, a drop in scores was observed, and performance was slowed, on a cognitive skill while supine. These results demonstrate a body position-dependent shift in olfactory sensitivity only for perithreshold odors that appears to be mediated by cognitive rather than physiological factors. Implications for olfactory imaging studies are discussed.

  6. Shifting the Sun: Solar Spectral Conversion and Extrinsic Sensitization in Natural and Artificial Photosynthesis.

    Wondraczek, Lothar; Tyystjärvi, Esa; Méndez-Ramos, Jorge; Müller, Frank A; Zhang, Qinyuan

    2015-12-01

    Solar energy harvesting is largely limited by the spectral sensitivity of the employed energy conversion system, where usually large parts of the solar spectrum do not contribute to the harvesting scheme, and where, of the contributing fraction, the full potential of each photon is not efficiently used in the generation of electrical or chemical energy. Extrinsic sensitization through photoluminescent spectral conversion has been proposed as a route to at least partially overcome this problem. Here, we discuss this approach in the emerging context of photochemical energy harvesting and storage through natural or artificial photosynthesis. Clearly contrary to application in photovoltaic energy conversion, implementation of solar spectral conversion for extrinsic sensitization of a photosynthetic machinery is very straightforward, and-when compared to intrinsic sensitization-less-strict limitations with regard to quantum coherence are seen. We now argue the ways in which extrinsic sensitization through photoluminescent spectral converters will-and will not-play its role in the area of ultra-efficient photosynthesis, and also illustrate how such extrinsic sensitization requires dedicated selection of specific conversion schemes and design strategies on system scale.

  7. Non-stationarity and power spectral shifts in EMG activity reflect motor unit recruitment in rat diaphragm muscle.

    Seven, Yasin B; Mantilla, Carlos B; Zhan, Wen-Zhi; Sieck, Gary C

    2013-01-15

    We hypothesized that a shift in diaphragm muscle (DIAm) EMG power spectral density (PSD) to higher frequencies reflects recruitment of more fatigable fast-twitch motor units and motor unit recruitment is reflected by EMG non-stationarity. DIAm EMG was recorded in anesthetized rats during eupnea, hypoxia-hypercapnia (10% O(2)-5% CO(2)), airway occlusion, and sneezing (maximal DIAm force). Although power in all frequency bands increased progressively across motor behaviors, PSD centroid frequency increased only during sneezing (pmotor units were recruited during different motor behaviors. Motor units augmented their discharge frequencies progressively beyond the non-stationary period; yet, EMG signal became stationary. In conclusion, non-stationarity of DIAm EMG reflects the period of motor unit recruitment, while a shift in the PSD towards higher frequencies reflects recruitment of more fatigable fast-twitch motor units. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Low-to-High Confinement Transition Mediated by Turbulence Radial Wave Number Spectral Shift in a Fusion Plasma.

    Xu, G S; Wan, B N; Wang, H Q; Guo, H Y; Naulin, V; Rasmussen, J Juul; Nielsen, A H; Wu, X Q; Yan, N; Chen, L; Shao, L M; Chen, R; Wang, L; Zhang, W

    2016-03-04

    A new model for the low-to-high (L-H) confinement transition has been developed based on a new paradigm for turbulence suppression by velocity shear [G. M. Staebler et al., Phys. Rev. Lett. 110, 055003 (2013)]. The model indicates that the L-H transition can be mediated by a shift in the radial wave number spectrum of turbulence, as evidenced here, for the first time, by the direct observation of a turbulence radial wave number spectral shift and turbulence structure tilting prior to the L-H transition at tokamak edge by direct probing. This new mechanism does not require a pretransition overshoot in the turbulent Reynolds stress, shunting turbulence energy to zonal flows for turbulence suppression as demonstrated in the experiment.

  9. Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

    Caraveo-Frescas, J. A.

    2012-03-09

    It is shown that the well-known negative flatband voltage (VFB) shift, induced by rare-earth oxide capping in metal gate stacks, can be completely reversed in the absence of the silicon overlayer. Using TaN metal gates and Gd2O3-doped dielectric, we measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which originates from an interfacial dipole. The dipole is created by the replacement of interfacial oxygen atoms in the HfO2 lattice with nitrogen atoms from TaN.

  10. Diagrammatic expansion for positive spectral functions beyond GW: Application to vertex corrections in the electron gas

    Stefanucci, G.; Pavlyukh, Y.; Uimonen, A.-M.; van Leeuwen, R.

    2014-09-01

    We present a diagrammatic approach to construct self-energy approximations within many-body perturbation theory with positive spectral properties. The method cures the problem of negative spectral functions which arises from a straightforward inclusion of vertex diagrams beyond the GW approximation. Our approach consists of a two-step procedure: We first express the approximate many-body self-energy as a product of half-diagrams and then identify the minimal number of half-diagrams to add in order to form a perfect square. The resulting self-energy is an unconventional sum of self-energy diagrams in which the internal lines of half a diagram are time-ordered Green's functions, whereas those of the other half are anti-time-ordered Green's functions, and the lines joining the two halves are either lesser or greater Green's functions. The theory is developed using noninteracting Green's functions and subsequently extended to self-consistent Green's functions. Issues related to the conserving properties of diagrammatic approximations with positive spectral functions are also addressed. As a major application of the formalism we derive the minimal set of additional diagrams to make positive the spectral function of the GW approximation with lowest-order vertex corrections and screened interactions. The method is then applied to vertex corrections in the three-dimensional homogeneous electron gas by using a combination of analytical frequency integrations and numerical Monte Carlo momentum integrations to evaluate the diagrams.

  11. Artificial light pollution: Shifting spectral wavelengths to mitigate physiological and health consequences in a nocturnal marsupial mammal.

    Dimovski, Alicia M; Robert, Kylie A

    2018-05-02

    The focus of sustainable lighting tends to be on reduced CO 2 emissions and cost savings, but not on the wider environmental effects. Ironically, the introduction of energy-efficient lighting, such as light emitting diodes (LEDs), may be having a great impact on the health of wildlife. These white LEDs are generated with a high content of short-wavelength 'blue' light. While light of any kind can suppress melatonin and the physiological processes it regulates, these short wavelengths are potent suppressors of melatonin. Here, we manipulated the spectral composition of LED lights and tested their capacity to mitigate the physiological and health consequences associated with their use. We experimentally investigated the impact of white LEDs (peak wavelength 448 nm; mean irradiance 2.87 W/m 2 ), long-wavelength shifted amber LEDs (peak wavelength 605 nm; mean irradiance 2.00 W/m 2 ), and no lighting (irradiance from sky glow light treatments. White LED exposed wallabies had significantly suppressed nocturnal melatonin compared to no light and amber LED exposed wallabies, while there was no difference in lipid peroxidation. Antioxidant capacity declined from baseline to week 10 under all treatments. These results provide further evidence that short-wavelength light at night is a potent suppressor of nocturnal melatonin. Importantly, we also illustrate that shifting the spectral output to longer wavelengths could mitigate these negative physiological impacts. © 2018 Wiley Periodicals, Inc.

  12. Methane spectral line widths and shifts, and dependences on physical parameters

    Fox, K.; Quillen, D. T.; Jennings, D. E.; Wagner, J.; Plymate, C.

    1991-01-01

    A detailed report of the recent high-resolution spectroscopic research on widths and shifts measured for a strong infrared-active fundamental of methane is presented. They were measured in collision with several rare gases and diatomic molecules, in the vibrational-rotational fundamental near 3000/cm. These measurements were made at an ambient temperature of 294 K over a range of pressures from 100 to 700 torr. The measurements are discussed in a preliminary but detailed and quantitative manner with reference to masses, polarizabilities, and quadrupole moments. Some functional dependences on these physical parameters are considered. The present data are useful for studies of corresponding planetary spectra.

  13. Researcher-researched relationship in qualitative research: Shifts in positions and researcher vulnerability.

    Råheim, Målfrid; Magnussen, Liv Heide; Sekse, Ragnhild Johanne Tveit; Lunde, Åshild; Jacobsen, Torild; Blystad, Astrid

    2016-01-01

    The researcher role is highly debated in qualitative research. This article concerns the researcher-researched relationship. A group of health science researchers anchored in various qualitative research traditions gathered in reflective group discussions over a period of two years. Efforts to establish an anti-authoritarian relationship between researcher and researched, negotiation of who actually "rules" the research agenda, and experiences of shifts in "inferior" and "superior" knowledge positions emerged as central and intertwined themes throughout the discussions. The dual role as both insider and outsider, characteristic of qualitative approaches, seemed to lead to power relations and researcher vulnerability which manifested in tangible ways. Shifting positions and vulnerability surfaced in various ways in the projects. They nonetheless indicated a number of similar experiences which can shed light on the researcher-researched relationship. These issues could benefit from further discussion in the qualitative health research literature.

  14. Determination of the positions and residues of the. delta. /sup + +/ and. delta. /sup 0/ poles. [Phase shifts,coulomb corrections

    Vasan, S S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1976-04-19

    The poles and the associated residues in the ..pi..N P/sub 33/ amplitude corresponding to the resonances ..delta../sup + +/ and ..delta../sup 0/ are determined by fitting the ..pi../sup +/p and ..pi../sup -/p hadronic phase shifts from the Carter 73 analysis. The ..delta../sup + +/ and ..delta../sup 0/ pole positions are determined also from the nuclear phase shifts, these being the phase shifts made up of the hadronic phase shifts plus the Coulomb corrections. The pole positions obtained from the two sets of phase shifts are different, the differences being larger in the case of the ..delta../sup + +/.

  15. [Spectral navigation technology and its application in positioning the fruits of fruit trees].

    Yu, Xiao-Lei; Zhao, Zhi-Min

    2010-03-01

    An innovative technology of spectral navigation is presented in the present paper. This new method adopts reflectance spectra of fruits, leaves and branches as one of the key navigation parameters and positions the fruits of fruit trees relying on the diversity of spectral characteristics. The research results show that the distinct smoothness as effect is available in the spectrum of leaves of fruit trees. On the other hand, gradual increasing as the trend is an important feature in the spectrum of branches of fruit trees while the spectrum of fruit fluctuates. In addition, the peak diversity of reflectance rate between fruits and leaves of fruit trees is reached at 850 nm of wavelength. So the limit value can be designed at this wavelength in order to distinguish fruits and leaves. The method introduced here can not only quickly distinguish fruits, leaves and branches, but also avoid the effects of surroundings. Compared with the traditional navigation systems based on machine vision, there are still some special and unique features in the field of positioning the fruits of fruit trees using spectral navigation technology.

  16. Indicating pressure and environmental effects by means of the spectral shift with rhodamine B and fluorescein

    R. M. Johann

    2015-07-01

    Full Text Available Fluorescence absorption and emission wavelengths can be influenced by environmental conditions, such as pressure, temperature and concentration. Here those effects are explored with an emphasis on determining the potential of rhodamine B and fluorescein as high-pressure indicators. The red shift of the emission peak maxima of rhodamine B and fluorescein are investigated in dependence of pressure up to 200 MPa using as the solvents water, ethanol and poly(dimethylsiloxane (PDMS with rhodamine B and water, polystyrene beads and melamine resin beads with fluorescein. Emission spectra recording and peak fitting is done automatically at time intervals of down to a second and with 0.3 nm wavelength resolution. The wavenumber-pressure relation for rhodamine B reveals increasing divergence from linear behavior in the sequence of the solvents water, ethanol and silicone rubber. Graphical correlation of the data diverging only slightly from linearity with a selection of polarity functions is enabled using the concept of ‘deviation from linearity (DL’ plots. Using the example of rhodamine B dissolved in PDMS elastomer it is shown that there is a temperature induced irreversible molecular reordering, when scanning between 3 and ∼50°C, and a polarity change in the proximity of the embedded dye molecule. Swelling studies are performed with PDMS containing rhodamine B, where the elastomer is first put in water, then in ethanol and again in water. There a complex solvent exchange process is revealed in the elastomer demonstrating the feasibility of fluorescence spectroscopy, when observing variations in wavelength, to indicate and enlighten molecular rearrangements and swelling dynamics in the polymer, and polarity changes and solvent exchange processes in the dye solvation shell.

  17. Emotional bias of sleep-dependent processing shifts from negative to positive with aging.

    Jones, Bethany J; Schultz, Kurt S; Adams, Sydney; Baran, Bengi; Spencer, Rebecca M C

    2016-09-01

    Age-related memory decline has been proposed to result partially from impairments in memory consolidation over sleep. However, such decline may reflect a shift toward selective processing of positive information with age rather than impaired sleep-related mechanisms. In the present study, young and older adults viewed negative and neutral pictures or positive and neutral pictures and underwent a recognition test after sleep or wake. Subjective emotional reactivity and affect were also measured. Compared with waking, sleep preserved valence ratings and memory for positive but not negative pictures in older adults and negative but not positive pictures in young adults. In older adults, memory for positive pictures was associated with slow wave sleep. Furthermore, slow wave sleep predicted positive affect in older adults but was inversely related to positive affect in young adults. These relationships were strongest for older adults with high memory for positive pictures and young adults with high memory for negative pictures. Collectively, these results indicate preserved but selective sleep-dependent memory processing with healthy aging that may be biased to enhance emotional well-being. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Motivational intensity modulates the effects of positive emotions on set shifting after controlling physiological arousal.

    Zhou, Ya; Siu, Angela F Y

    2015-12-01

    Recent research on the construct of emotion suggests the integration of a motivational dimension into the traditional two-dimension (subjective valence and physiological arousal) model. The motivational intensity of an emotional state should be taken into account while investigating the emotion-cognition relationship. This study examined how positive emotional states varying in motivational intensity influenced set shifting, after controlling the potential confounding impacts of physiological arousal. In Experiment 1, 155 volunteers performed a set-shifting task after being randomly assigned to five states: high- vs. low-motivating positive affect (interest vs. serenity), high- vs. low-motivating negative affect (disgust vs. anxiety), and neutral state. Eighty-five volunteers participated in Experiment 2, which further examined the effects of higher vs. lower degree of interest. Both experiments measured and compared participants' physiological arousal (blood pressure and pulse rate) under the normal and experimental conditions as the covariate. Results showed no difference in switching performance between the neutral and serenity groups. As compared with the neutral state, the high-motivating positive affect significantly increased set-switching reaction time costs, but reduced error rate costs; the higher the motivational intensity, the greater the time-costs impairment. This indicates a role of the high-motivating positive affect in regulating the balance between the flexible and stable cognitive control. Motivational intensity also modulated the effects of negative emotional states, i.e., disgust caused a larger increase in time costs than anxiety. Further exploration into neurobiological mechanisms that may mediate the emotional effects on set shifting is warranted. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  19. Positive XPS binding energy shift of supported Cu{sub N}-clusters governed by initial state effects

    Peters, S.; Peredkov, S. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); Al-Hada, M. [Department of Physics, College of Education and Linguistics, University of Amran (Yemen); Neeb, M., E-mail: matthias.neeb@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Wilhelm-Conrad-Röntgen-Campus Adlershof, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin (Germany); Eberhardt, W. [Technische Universität Berlin, IOAP, Strasse des 17. Juni 135, 10623 Berlin (Germany); DESY, Center for Free Electron Laser Science (CFEL), Notkestr. 85, 22607 Hamburg (Germany)

    2014-01-01

    Highlights: • Size dependent initial and final state effects of mass-selected deposited clusters. • Initial state effect dominates positive XPS shift in supported Cu-clusters. • Size dependent Coulomb correlation shift in the Auger final state of Cu cluster. • Size-dependent Auger parameter analysis. • Positive XPS shift differs from negative surface core level shift in crystalline copper. - Abstract: An initial state effect is established as origin for the positive 2p core electron binding energy shift found for Cu{sub N}-clusters supported by a thin silica layer of a p-doped Si(1 0 0) wafer. Using the concept of the Auger parameter and taking into account the usually neglected Coulomb correlation shift in the Auger final state (M{sub 4,5}M{sub 4,5}) it is shown that the initial state shift is comparable to the measured XPS shift while the final state relaxation shift contributes only marginally to the binding energy shift. The cluster results differ from the negative surface core-level shift of crystalline copper which has been explained in terms of a final state relaxation effect.

  20. Methodology to reduce 6D patient positional shifts into a 3D linear shift and its verification in frameless stereotactic radiotherapy

    Sarkar, Biplab; Ray, Jyotirmoy; Ganesh, Tharmarnadar; Manikandan, Arjunan; Munshi, Anusheel; Rathinamuthu, Sasikumar; Kaur, Harpreet; Anbazhagan, Satheeshkumar; Giri, Upendra K.; Roy, Soumya; Jassal, Kanan; Kalyan Mohanti, Bidhu

    2018-04-01

    The aim of this article is to derive and verify a mathematical formulation for the reduction of the six-dimensional (6D) positional inaccuracies of patients (lateral, longitudinal, vertical, pitch, roll and yaw) to three-dimensional (3D) linear shifts. The formulation was mathematically and experimentally tested and verified for 169 stereotactic radiotherapy patients. The mathematical verification involves the comparison of any (one) of the calculated rotational coordinates with the corresponding value from the 6D shifts obtained by cone beam computed tomography (CBCT). The experimental verification involves three sets of measurements using an ArcCHECK phantom, when (i) the phantom was not moved (neutral position: 0MES), (ii) the position of the phantom shifted by 6D shifts obtained from CBCT (6DMES) from neutral position and (iii) the phantom shifted from its neutral position by 3D shifts reduced from 6D shifts (3DMES). Dose volume histogram and statistical comparisons were made between ≤ft and ≤ft . The mathematical verification was performed by a comparison of the calculated and measured yaw (γ°) rotation values, which gave a straight line, Y  =  1X with a goodness of fit as R 2  =  0.9982. The verification, based on measurements, gave a planning target volume receiving 100% of the dose (V100%) as 99.1  ±  1.9%, 96.3  ±  1.8%, 74.3  ±  1.9% and 72.6  ±  2.8% for the calculated treatment planning system values TPSCAL, 0MES, 3DMES and 6DMES, respectively. The statistical significance (p-values: paired sample t-test) of V100% were found to be 0.03 for the paired sample ≤ft and 0.01 for ≤ft . In this paper, a mathematical method to reduce 6D shifts to 3D shifts is presented. The mathematical method is verified by using well-matched values between the measured and calculated γ°. Measurements done on the ArcCHECK phantom also proved that the proposed methodology is correct. The post-correction of the

  1. Spectral radiance of strong lines in positive column mercury discharges with argon carrier gas

    Sansonetti, Craig J; Reader, Joseph

    2006-01-01

    The spectral radiance of the 185 and 254 nm lines in two positive column mercury discharge lamps was measured over a wide range of operating conditions. The lamps had internal diameters of 5 and 23 mm. Argon was used as a carrier gas. The lamps were operated with cold spot temperatures of 20, 40 and 60 0 C. At each of these temperatures, results were obtained for five currents ranging from 20 to 100 mA for the 5 mm lamp and from 200 to 1000 mA for the 23 mm lamp. For each current studied, results were determined for argon pressures ranging from 66.6 to 666 Pa (0.5 to 5.0 Torr) in the 5 mm lamp and 26.6 to 666 Pa (0.2 to 5.0 Torr) in the 23 mm lamp. An argon miniarc was used as the radiometric standard. By calibrating the spectral response of the optical system with a well-characterized mercury pencil lamp, results were obtained for 12 additional Hg lines from 289 to 579 nm. For the 23 mm lamp the electric field in the positive column was measured. For this lamp the radiated power as a percentage of input power was also determined. The results provide an experimental basis for validating computer models of Hg fluorescent lamp discharges

  2. Lattice gauge fixing as quenching and the violation of spectral positivity

    Aubin, C.; Ogilvie, Michael C.

    2004-01-01

    Lattice Landau gauge and other related lattice gauge-fixing schemes are known to violate spectral positivity. The most direct sign of the violation is the rise of the effective mass as a function of distance. The origin of this phenomenon lies in the quenched character of the auxiliary field g used to implement lattice gauge-fixing, and is similar to quenched QCD in this respect. This is best studied using the Parrinello Jona-Lasinio Zwanziger formalism, leading to a class of covariant gauges similar to the one-parameter class of covariant gauges commonly used in continuum gauge theories. Soluble models are used to illustrate the origin of the violation of spectral positivity. The phase diagram of the lattice theory, as a function of the gauge coupling β and the gauge-fixing parameter α, is similar to that of the unquenched theory, a Higgs model of a type first studied by Fradkin and Shenker. The gluon propagator is interpreted as yielding bound states in the confined phase, and a mixture of fundamental particles in the Higgs phase, but lattice simulation shows the two phases are connected. Gauge-field propagators from the simulation of an SU(2) lattice gauge theory on a 20 4 lattice are well described by a quenched mass-mixing model. The mass of the lightest state, which we interpret as the gluon mass, appears to be independent of α for sufficiently large α

  3. Economic assessment of energy storage for load shifting in Positive Energy Building

    Dumont, Olivier; Carmo, Carolina; Georges, Emeline

    2016-01-01

    Net Zero Energy Buildings (NZEB) and Positive Energy Buildings (PEB) are gaining more and more interest. In this paper, the impact of the integration of a battery in a positive energy building is assessed in order to increase its self-consumption of electricity. Parametric studies are carried out......-in tariff and a 5 kWh battery. Finally, simple correlations (based on the feed-in tariff, the annual electrical consumption and production) to predict the optimal size of battery and the lowest payback period are proposed.......Net Zero Energy Buildings (NZEB) and Positive Energy Buildings (PEB) are gaining more and more interest. In this paper, the impact of the integration of a battery in a positive energy building is assessed in order to increase its self-consumption of electricity. Parametric studies are carried out...... by varying the building envelope characteristics, the power supply system, the climate, the lightning and appliances profiles, the roof tilt, the battery size and the electricity tariffs, leading to 3200 cases. The analysis is performed on an annual basis in terms of self-consumption rate, shifted energy...

  4. The Spectral Shift Control Reactor as an option for much improved uranium utilisation in single-batch SMRs

    Lindley, B.A., E-mail: bal29@cam.ac.uk; Parks, G.T.

    2016-12-01

    Highlights: • A PWR with mixed D{sub 2}O/H{sub 2}O moderator/coolant is investigated for SMR applications. • Heavy water concentration varied over the cycle to give ‘spectral shift’ operation. • Much wetter lattice than normal is neutronically favourable. • Taller fuel stack is thus needed to ensure acceptable MDNBR. • 35–43% increase in uranium utilisation for single batch reactor is possible. - Abstract: The Spectral Shift Control Reactor (SSCR) uses a mix of D{sub 2}O and H{sub 2}O to moderate and cool the reactor. Initially, a high proportion of D{sub 2}O is used, such that the reactor is substantially under-moderated, with excess neutrons being primarily captured in {sup 238}U, breeding {sup 239}Pu. Towards the end of the cycle (EOC), the coolant is predominantly H{sub 2}O, thermalising the neutron spectrum and increasing reactivity. Recently, small modular reactors (SMRs) have gained significant interest as a means of providing a power source that requires little maintenance and refuelling. This motivates long cycles and reduced batch operation. For a single-batch reactor, there is typically a 33% penalty to uranium utilisation compared to a 3-batch reactor. Lattice calculations demonstrate the potential of the SSCR to greatly improve uranium utilisation in single-batch reactors over a range of enrichments. A relatively ‘wet’ lattice is employed which further improves uranium utilisation. Cases with 5% and 15% fissile loading are considered, for which it is respectively possible to achieve 47% and 39% increases in natural uranium utilisation using the SSCR relative to a ‘reference’ light water reactor. In the latter case, if 25% thorium is mixed into the fuel, the improvement in uranium utilisation increases to a total of 49%. Hence, in both cases, it is possible to in effect eliminate the penalty of using a single fuel batch. The ‘wet’ lattice introduces substantial thermal-hydraulic challenges due to the significantly higher fuel

  5. Results of neutron measurements in the spectral position of the Juelich FKS steel irradiation capsules

    Schneider, W.

    1986-10-01

    This is a report on the planning and results of neutron monitoring in the capsules of the Juelich steel irradiation for the research project on component safety (FKS). The table of results and their discussion is provided specifically for the spectral positions (for characterising the neutron spectrum) in each of the types of irradiation capsules used. The results are given for the reaction rates of the neutron measurement reactions used (activation or fission reactions), for the neutron flux densities and fluxes derived from them related to the actual or at least plausible neutron spectra and finally for the radiation damage (or exposure) of the irradiated material calculated from them, expressed as the atomic displacement figure (dpa) and its percentage in sections of the neutron spectrum. (orig.) [de

  6. Simulation and optimisation of a position sensitive scintillation detector with wavelength shifting fibers for thermal neutrons

    Herzkamp, Matthias; Engels, Ralf; Kemmerling, Guenter [ZEA-2, Forschungszentrum Juelich (Germany); Brueckel, Thomas [JCNS, Forschungszentrum Juelich (Germany); Stahl, Achim [III. Physikalisches Institut B, RWTH Aachen (Germany); Waasen, Stefan van [ZEA-2, Forschungszentrum Juelich (Germany); Faculty of Engineering, University of Duisburg-Essen (Germany)

    2015-07-01

    In neutron scattering experiments it is important to have position sensitive large scale detectors for thermal neutrons. A detector based on a neutron scintillator with wave length shifting fibers is a new kind of such a detector. We present the simulation of the detector based on the microscopic structure of the scintillation material of the mentioned detector. It consists of a converter and a scintillation powder bound in a matrix. The converter in our case is lithium fluoride with enriched lithium 6, to convert thermal neutrons into high energetic alpha and triton particles. The scintillation material is silver doped zinc sulfide. We show that pulse height spectra obtained by these scintillators can be be explained by the simple model of randomly distributed spheres of zinc sulfide and lithium fluoride. With this model, it is possible to optimise the mass ratio of zinc sulfide to lithium fluoride with respect to detection efficiency and/or energy deposition in zinc sulfide.

  7. A Developmental Shift from Positive to Negative Connectivity in Human Amygdala-Prefrontal Circuitry

    Gee, Dylan G.; Humphreys, Kathryn L.; Flannery, Jessica; Goff, Bonnie; Telzer, Eva H.; Shapiro, Mor; Hare, Todd A.; Bookheimer, Susan Y.; Tottenham, Nim

    2013-01-01

    Recent human imaging and animal studies highlight the importance of frontoamygdala circuitry in the regulation of emotional behavior and its disruption in anxiety-related disorders. While tracing studies have suggested changes in amygdala-cortical connectivity through the adolescent period in rodents, less is known about the reciprocal connections within this circuitry across human development, when these circuits are being fine-tuned and substantial changes in emotional control are observed. The present study examined developmental changes in amygdala-prefrontal circuitry across the ages of 4 to 22 years using task-based functional magnetic resonance imaging (fMRI). Results suggest positive amygdala-prefrontal connectivity in early childhood that switches to negative functional connectivity during the transition to adolescence. Amygdala-mPFC functional connectivity was significantly positive (greater than zero) among participants younger than ten, whereas functional connectivity was significantly negative (less than zero) among participants ten years and older, over and above the effect of amygdala reactivity. The developmental switch in functional connectivity was paralleled by a steady decline in amygdala reactivity. Moreover, the valence switch might explain age-related improvement in task performance and a developmentally normative decline in anxiety. Initial positive connectivity followed by a valence shift to negative connectivity provides a neurobiological basis for regulatory development and may present novel insight into a more general process of developing regulatory connections. PMID:23467374

  8. Development of advanced BWR fuel bundle with spectral shift rod (3) -transient analysis of ABWR core with SSR

    Ikegawa, T.; Chaki, M.; Ohga, Y.; Abe, M.

    2010-01-01

    The spectral shift rod (SSR) is a new type of water rod, utilized instead of the conventional water rod, in which a water level develops during core operation. The water level can be changed according to the fuel channel flow rate. In this study, ABWR plant performance with SSR fuel bundles under transient conditions has been evaluated using the TRACG code. The TRACG code, which can treat three-dimensional hydrodynamic calculations in a reactor pressure vessel, is well suited for evaluating the reactor transient performance with the SSR fuel bundles because it can calculate the water levels in the SSR at each channel grouping and therefore evaluate the core reactivity according to the water level changes in the SSR. 'Generator load rejection with total turbine bypass failure' and 'Recirculation flow control failure with increasing flow' were selected as cases which may increase the reactivity with the increasing water level in the SSR. It was found that the absolute value of the void reactivity coefficient in the SSR core was larger than that in the conventional water rod core because the core averaged void fraction in the SSR core, which has the vapor region above the water level in the SSR, was larger than that in the conventional water rod core. Therefore, AMCPR for the SSR core was a little larger than that for the conventional water rod core; however, the difference was smaller than 0.02 because the inlet of the SSR ascending path was designed to be small enough to prevent the rapid water level increase in the SSR. (authors)

  9. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method

    Weifang Sun

    2017-08-01

    Full Text Available Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  10. Health State Monitoring of Bladed Machinery with Crack Growth Detection in BFG Power Plant Using an Active Frequency Shift Spectral Correction Method.

    Sun, Weifang; Yao, Bin; He, Yuchao; Chen, Binqiang; Zeng, Nianyin; He, Wangpeng

    2017-08-09

    Power generation using waste-gas is an effective and green way to reduce the emission of the harmful blast furnace gas (BFG) in pig-iron producing industry. Condition monitoring of mechanical structures in the BFG power plant is of vital importance to guarantee their safety and efficient operations. In this paper, we describe the detection of crack growth of bladed machinery in the BFG power plant via vibration measurement combined with an enhanced spectral correction technique. This technique enables high-precision identification of amplitude, frequency, and phase information (the harmonic information) belonging to deterministic harmonic components within the vibration signals. Rather than deriving all harmonic information using neighboring spectral bins in the fast Fourier transform spectrum, this proposed active frequency shift spectral correction method makes use of some interpolated Fourier spectral bins and has a better noise-resisting capacity. We demonstrate that the identified harmonic information via the proposed method is of suppressed numerical error when the same level of noises is presented in the vibration signal, even in comparison with a Hanning-window-based correction method. With the proposed method, we investigated vibration signals collected from a centrifugal compressor. Spectral information of harmonic tones, related to the fundamental working frequency of the centrifugal compressor, is corrected. The extracted spectral information indicates the ongoing development of an impeller blade crack that occurred in the centrifugal compressor. This method proves to be a promising alternative to identify blade cracks at early stages.

  11. Cumulative-Phase-Alteration of Galactic-Light Passing Through the Cosmic-Microwave-Background: A New Mechanism for Some Observed Spectral-Shifts

    Tank H. K.

    2012-07-01

    Full Text Available Currently, whole of the measured “cosmological-red-shift ” is interpreted as due to the “metric-expansion-of-space”; so for the required “closer -density” of the universe, we need twenty times more mass-energy than the visible baryonic-matter contained in the universe. This paper proposes a new mechanism, which can account for good per- centage of the red-shift in the extra-galactic-light, greatly reducing the requirement of dark matter-energy. Also, this mechanism can cause a new kin d of blue-shift reported here, and their observational evidences. These spectral-s hifts are proposed to result due to cumulative phase-alteration of extra-galactic-light b ecause of vector-addition of: (i electric-field of extra-galactic-light and (ii that of the cosmic-microwave-background (CMB. Since the center-frequency of CMB is much lower than extra-galactic-light, the cumulative-phase-alteration results in red -shift, observed as an additional contribu- tor to the measured “cosmological red-shift”; and since the center-frequency of CMB is higher than the radio-frequency-signals used to measure velocity of space-probes like: Pioneer-10, Pioneer-11, Galileo and Ulysses, the cum ulative-phase-alteration re- sulted in blue-shift, leading to the interpretation of deceleration of these space-probes. While the galactic-light experiences the red-shift, and th e ranging-signals of the space- probes experience blue -shift, they are comparable in magnitude, providing a supportive- evidence for the new mechanism proposed here. More confirmative-experiments for this new mechanism are also proposed.

  12. Efficiency enhancement of ZnO nanostructure assisted Si solar cell based on fill factor enlargement and UV-blue spectral down-shifting

    Gholizadeh, A; Reyhani, A; Mortazavi, S Z; Parvin, P

    2017-01-01

    ZnO nanostructures (including nano-plates and nano-rods (NRs)) are grown in various temperatures and Ar/O 2 flow rates using thermal chemical vapor deposition, which affect the structure, nano-plate/NR population, and the quality of ZnO nanostructures. X-ray diffraction (XRD) attests that the peak intensity of the crystallographic plane (1 0 0) is correlated to nano-plate abundance. Moreover, optical properties elucidate that the population of nano-plates in samples strongly affect the band gap, binding energy of the exciton, and UV–visible (UV–vis) absorption and spectral luminescence emissions. In fact, the exciton binding energy reduces from ∼100 to 80 meV when the population of nano-plates increases in samples. Photovoltaic characteristics based on the drop-casting on Si solar cells reveals three dominant factors, namely, the equivalent series resistance, decreasing reflectance, and down-shifting, in order to scale up the absolute efficiency by 3%. As a consequence, the oxygen vacancies in ZnO nanostructures give rise to the down-shifting and increase of free-carriers, leading to a reduction in the equivalent series resistance and an enlargement of fill factor. To obtain a larger I sc , reduction of spectral reflectance is essential; however, the down-shifting process is shown to be dominant by lessening the surface electron-hole recombination rate over the UV–blue spectral range. (paper)

  13. Efficiency enhancement of ZnO nanostructure assisted Si solar cell based on fill factor enlargement and UV-blue spectral down-shifting

    Gholizadeh, A.; Reyhani, A.; Parvin, P.; Mortazavi, S. Z.

    2017-05-01

    ZnO nanostructures (including nano-plates and nano-rods (NRs)) are grown in various temperatures and Ar/O2 flow rates using thermal chemical vapor deposition, which affect the structure, nano-plate/NR population, and the quality of ZnO nanostructures. X-ray diffraction (XRD) attests that the peak intensity of the crystallographic plane (1 0 0) is correlated to nano-plate abundance. Moreover, optical properties elucidate that the population of nano-plates in samples strongly affect the band gap, binding energy of the exciton, and UV-visible (UV-vis) absorption and spectral luminescence emissions. In fact, the exciton binding energy reduces from ~100 to 80 meV when the population of nano-plates increases in samples. Photovoltaic characteristics based on the drop-casting on Si solar cells reveals three dominant factors, namely, the equivalent series resistance, decreasing reflectance, and down-shifting, in order to scale up the absolute efficiency by 3%. As a consequence, the oxygen vacancies in ZnO nanostructures give rise to the down-shifting and increase of free-carriers, leading to a reduction in the equivalent series resistance and an enlargement of fill factor. To obtain a larger I sc, reduction of spectral reflectance is essential; however, the down-shifting process is shown to be dominant by lessening the surface electron-hole recombination rate over the UV-blue spectral range.

  14. Thermal hydraulic test of advanced fuel bundle with spectral shift rod (SSR) for BWR. Effect of thermal hydraulic parameters on steady state characteristics

    Kondo, Takao; Kitou, Kazuaki; Chaki, Masao; Ohga, Yukiharu; Makigami, Takeshi

    2011-01-01

    Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR's merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test results of the base geometry case in SSR thermal hydraulic test, which was conducted under the national project of next generation LWR. In the test, thermal hydraulic parameters, such as flow rate, pressure, inlet subcooling and heater rod power are changed to evaluate these effects on SSR water level and other SSR characteristics. In the test results, SSR water level rose as flow rate rose, which showed controllability of SSR water level by flow rate. The sensitivities of other thermal hydraulic parameters on SSR water level were also evaluated. The obtained data of parameter's sensitivities is various enough for the further analytical evaluation. The fluctuation of SSR water level was also measured to be small enough. As a result, it was confirmed that SSR's steady state performance was as planned and that SSR design concept is feasible. (author)

  15. Anticipating regime shifts in gene expression: The case of an autoactivating positive feedback loop

    Sharma, Yogita; Dutta, Partha Sharathi; Gupta, A. K.

    2016-03-01

    Considerable evidence suggests that anticipating sudden shifts from one state to another in bistable dynamical systems is a challenging task; examples include ecosystems, financial markets, and complex diseases. In this paper, we investigate the effects of additive, multiplicative, and cross-correlated stochastic perturbations on determining the regime shifts in a bistable gene regulatory system, which gives rise to two distinct states of low and high concentrations of protein. We obtain the stationary probability density and mean first-passage time of the system. We show that increasing the additive (multiplicative) noise intensity induces a regime shift from a low (high) to a high (low) protein concentration state. However, an increase in the cross-correlation intensity always induces regime shifts from a high to a low protein concentration state. For both bifurcation-induced (often called the tipping point) and noise-induced (called stochastic switching) regime shifts, we further explore the robustness of recently developed critical-down-based early warning signal (EWS) indicators (e.g., rising variance and lag-1 autocorrelation) on our simulated time-series data. We identify that using EWS indicators, prediction of an impending bifurcation-induced regime shift is relatively easier than that of a noise-induced regime shift in the considered system. Moreover, the success of EWS indicators also strongly depends upon the nature of the noise.

  16. High-resolution quantization based on soliton self-frequency shift and spectral compression in a bi-directional comb-fiber architecture

    Zhang, Xuyan; Zhang, Zhiyao; Wang, Shubing; Liang, Dong; Li, Heping; Liu, Yong

    2018-03-01

    We propose and demonstrate an approach that can achieve high-resolution quantization by employing soliton self-frequency shift and spectral compression. Our approach is based on a bi-directional comb-fiber architecture which is composed of a Sagnac-loop-based mirror and a comb-like combination of N sections of interleaved single-mode fibers and high nonlinear fibers. The Sagnac-loop-based mirror placed at the terminal of a bus line reflects the optical pulses back to the bus line to achieve additional N-stage spectral compression, thus single-stage soliton self-frequency shift (SSFS) and (2 N - 1)-stage spectral compression are realized in the bi-directional scheme. The fiber length in the architecture is numerically optimized, and the proposed quantization scheme is evaluated by both simulation and experiment in the case of N = 2. In the experiment, a quantization resolution of 6.2 bits is obtained, which is 1.2-bit higher than that of its uni-directional counterpart.

  17. Bloodstain detection and discrimination impacted by spectral shift when using an interference filter-based visible and near-infrared multispectral crime scene imaging system

    Yang, Jie; Messinger, David W.; Dube, Roger R.

    2018-03-01

    Bloodstain detection and discrimination from nonblood substances on various substrates are critical in forensic science as bloodstains are a critical source for confirmatory DNA tests. Conventional bloodstain detection methods often involve time-consuming sample preparation, a chance of harm to investigators, the possibility of destruction of blood samples, and acquisition of too little data at crime scenes either in the field or in the laboratory. An imaging method has the advantages of being nondestructive, noncontact, real-time, and covering a large field-of-view. The abundant spectral information provided by multispectral imaging makes it a potential presumptive bloodstain detection and discrimination method. This article proposes an interference filter (IF) based area scanning three-spectral-band crime scene imaging system used for forensic bloodstain detection and discrimination. The impact of large angle of views on the spectral shift of calibrated IFs is determined, for both detecting and discriminating bloodstains from visually similar substances on multiple substrates. Spectral features in the visible and near-infrared portion employed by the relative band depth method are used. This study shows that 1 ml bloodstain on black felt, gray felt, red felt, white cotton, white polyester, and raw wood can be detected. Bloodstains on the above substrates can be discriminated from cola, coffee, ketchup, orange juice, red wine, and green tea.

  18. Low-to-high confinement transition mediated by turbulence radial wave number spectral shift in a fusion plasma

    Xu, G. S.; Wan, B. N.; Wang, H. Q.

    2016-01-01

    A new model for the low-to-high (L-H) confinement transition has been developed based on a new paradigm for turbulence suppression by velocity shear [G. M. Staebler et al., Phys. Rev. Lett.110, 055003 (2013)]. The model indicates that the L-H transition can be mediated by a shift in the radial wa...

  19. Effect of asymmetric actuator and detector position on Coriolis flowmeter and measured phase shift

    Enz, Stephanie

    2010-01-01

    Coriolis flowmeters (CFM) are forced to vibrate by a periodic excitation usually applied midpipe through an electromagnetic actuator. From hands-on experience with industrial CFMs it appears, that the electromagnetic actuator has to be located as symmetric as possible. For CFM design and trouble...... perturbation analysis. The result is a simple analytical expression for the approximated phase shift, which offers a direct insight into how the location of the actuator influences the phase shift. It appears, that asymmetrical forcing combined with fluctuating pipe damping could be a factor contributing...... zero-point stability. The validity of the hypotheses, which are assumed to be basically similar for more complicated geometries, e.g. bended and/or dual pipe CFMs, with or without multiple actuators, is suggested to be tested using laboratory experiments with purpose built non-ideal CFMs....

  20. Narrative perspective shift at retrieval: The psychological-distance-mediated-effect on emotional intensity of positive and negative autobiographical memory.

    Gu, Xuan; Tse, Chi-Shing

    2016-10-01

    The present study manipulated participants' narrative perspectives (1st-personal pronoun "I" and 3rd-personal pronoun "He/She") to vary their field and observer visual perspectives that they took to retrieve autobiographical events and examine how the shifts in narrative perspective could influence the self-rated emotional intensity of autobiographical memory. Results showed that when narrative perspectives effectively shifted participants' visual perspectives from field to observer, they felt attenuated emotional intensities of positive and negative autobiographical memories. However, this did not occur when narrative perspectives effectively shifted the visual perspectives from observer to field. Multiple mediator models further showed that the changes in psychological distance and imagery vividness (a distance-related construct) of autobiographical memory mediated the relationship between the narrative perspective shift from the 1st- to 3rd-person and the reduction in the intensities of negative and positive emotion. This provides support for the role of psychological distancing in reducing the emotional intensity of autobiographical memory. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach

    Jiajie Fan

    2017-07-01

    Full Text Available With the expanding application of light-emitting diodes (LEDs, the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD, defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED’s optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1 the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2 the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs, and color rendering indexes (CRIs of phosphor-converted (pc-white LEDs, and also can estimate the residual color life.

  2. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach.

    Fan, Jiajie; Mohamed, Moumouni Guero; Qian, Cheng; Fan, Xuejun; Zhang, Guoqi; Pecht, Michael

    2017-07-18

    With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life.

  3. SU-F-J-47: Inherent Uncertainty in the Positional Shifts Determined by a Volumetric Cone Beam Imaging System

    Giri, U; Ganesh, T; Saini, V; Munshi, A; Sarkar, B; Mohanti, B

    2016-01-01

    Purpose: To quantify inherent uncertainty associated with a volumetric imaging system in its determination of positional shifts. Methods: The study was performed on an Elekta Axesse™ linac’s XVI cone beam computed tomography (CBCT) system. A CT image data set of a Penta- Guide phantom was used as reference image by placing isocenter at the center of the phantom.The phantom was placed arbitrarily on the couch close to isocenter and CBCT images were obtained. The CBCT dataset was matched with the reference image using XVI software and the shifts were determined in 6-dimensions. Without moving the phantom, this process was repeated 20 times consecutively within 30 minutes on a single day. Mean shifts and their standard deviations in all 6-dimensions were determined for all the 20 instances of imaging. For any given day, the first set of shifts obtained was kept as reference and the deviations of the subsequent 19 sets from the reference set were scored. Mean differences and their standard deviations were determined. In this way, data were obtained for 30 consecutive working days. Results: Tabulating the mean deviations and their standard deviations observed on each day for the 30 measurement days, systematic and random errors in the determination of shifts by XVI software were calculated. The systematic errors were found to be 0.03, 0.04 and 0.03 mm while random errors were 0.05, 0.06 and 0.06 mm in lateral, craniocaudal and anterio-posterior directions respectively. For rotational shifts, the systematic errors were 0.02°, 0.03° and 0.03° and random errors were 0.06°, 0.05° and 0.05° in pitch, roll and yaw directions respectively. Conclusion: The inherent uncertainties in every image guidance system should be assessed and baseline values established at the time of its commissioning. These shall be periodically tested as part of the QA protocol.

  4. Spectral fitting for signal assignment and structural analysis of uniformly {sup 13}C-labeled solid proteins by simulated annealing based on chemical shifts and spin dynamics

    Matsuki, Yoh; Akutsu, Hideo; Fujiwara, Toshimichi [Osaka University, Institute for Protein Research (Japan)], E-mail: tfjwr@protein.osaka-u.ac.jp

    2007-08-15

    We describe an approach for the signal assignment and structural analysis with a suite of two-dimensional {sup 13}C-{sup 13}C magic-angle-spinning solid-state NMR spectra of uniformly {sup 13}C-labeled peptides and proteins. We directly fit the calculated spectra to experimental ones by simulated annealing in restrained molecular dynamics program CNS as a function of atomic coordinates. The spectra are calculated from the conformation dependent chemical shift obtained with SHIFTX and the cross-peak intensities computed for recoupled dipolar interactions. This method was applied to a membrane-bound 14-residue peptide, mastoparan-X. The obtained C', C{sup {alpha}} and C{sup {beta}} chemical shifts agreed with those reported previously at the precisions of 0.2, 0.7 and 0.4 ppm, respectively. This spectral fitting program also provides backbone dihedral angles with a precision of about 50 deg. from the spectra even with resonance overlaps. The restraints on the angles were improved by applying protein database program TALOS to the obtained chemical shifts. The peptide structure provided by these restraints was consistent with the reported structure at the backbone RMSD of about 1 A.

  5. Final results of the cadmium and spectral ratios obtained inside of the fuel rod positioned in the central position of the IPEN/MB-01 nuclear reactor

    Bitelli, Ulysses d' Utra; Mura, Luiz Ernesto C.; Santos, Diogo Feliciano dos, E-mail: ubitelli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Lambiasi, Beatriz G.N. [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil)

    2015-07-01

    The spectral ratios are very important to determine some nuclear reactors parameters such as reaction rates, fuel lifetime, etc and some safety operational conditions. This study aims to determine the spectral ratios in 2 (two) spatial positions located inside the core of the Nuclear Reactor IPEN/MB-01. These places are at the central position of the nuclear reactor core in an asymptotic neutron flux region. The experiment consists in inserting different activation foil detectors inside an experimental fuel rod. The experimental rod is assembled at the central position of the reactor core. Activation neutron foil detectors of different elements such as {sup 197}Au, {sup 238}U, {sup 45}Sc, {sup 58}Ni, {sup 24}Mg, {sup 47}Ti and {sup 115m}In were used to cover a large range of neutron spectrum. Saturation activity per target nucleus was obtained by gamma spectrometry using a HPGe system. The experimental cadmium ratios compared with values computed by MCNP-4C code show good agreement. (author)

  6. A new method for determination of cocamidopropyl betaine synthesized from coconut oil through spectral shift of Eriochrome Black T

    Gholami, Ali; Golestaneh, Mahshid; Andalib, Zeinab

    2018-03-01

    Cocamidopropyl betaine (CAPB) is a zwitterionic surfactant that is synthesized using coconut oil and usually supplied in form of an aqueous solution with 25-37% w/w. In this study, a novel method based on UV-visible spectroscopy is developed for an accurate determination of CAPB synthesized from coconut oil. Eriochrome Black T (EBT) as a specific color indicator was added to CAPB and a red shift and color change were observed. This shift leads in increasing wavelength selectivity of the method. The change in the color intensity depends on the concentration of CAPB. By measuring the absorbance of a solution containing CAPB, its concentration was measured. After optimizing all the effective parameters, CAPB was detected in commercial real samples. Using the proposed approach, limit of quantification (LOQ) and relative standard deviation (RSD) were obtained about 4.30 × 10- 5 M and 4.8% respectively. None of unreacted materials or by-products, which were produced in the synthesis of CAPB, showed any interference in the determination of CAPB. This shows that the proposed method is specific and accurate, and can potentially be used for quantitative determination of CAPB in commercial samples with satisfactory results.

  7. 49 CFR 571.102 - Standard No. 102; Transmission shift position sequence, starter interlock, and transmission...

    2010-10-01

    ... position. S3.1.2Transmission braking effect. In vehicles having more than one forward transmission gear... driver has activated the vehicle's propulsion system: (a) The engine may stop and restart automatically... activated the vehicle's propulsion system if the vehicle can meet the requirements specified in paragraphs...

  8. Economic assessment of electric energy storage for load shifting in positive energy building

    Dumont, Olivier; Do Carmo, Carolina Madeira Ramos; Georges, Emeline

    2017-01-01

    Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the buildin...... and a 3.7 kWh battery. Finally, simple correlations (based on the feed-in tariff, the annual electrical consumption and production) to predict the optimal size of battery and the lowest payback period are proposed.......Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the building...... envelope characteristics, the power supply system, the climate, the lighting and appliances profiles, the roof tilt angle, the battery size and the electricity tariffs, leading to 3200 cases. The analysis is performed on an annual basis in terms of self-consumption and self-production rate and payback...

  9. English Learners' Participation in Mathematical Discussion: Shifting Positionings and Dynamic Identities

    Turner, Erin; Dominguez, Higinio; Maldonado, Luz; Empson, Susan

    2013-01-01

    This study investigated discursive positioning moves that facilitated Latino/a English learners' (ELs) opportunities to take on agentive problem-solving roles in group mathematical discussion. A focus on mechanisms that support students' agentive participation is consistent with the authors' view that recurrent experiences participating and being…

  10. Elevational Shifts in the Topographic Position of Polylepis Forest Stands in the Andes of Southern Peru

    Johanna M. Toivonen

    2017-12-01

    Full Text Available The patchy distribution of high-Andean treeline forests has provoked discussion about the relative importance of anthropogenic and climatic causes of this pattern, both of which vary with topography. We aimed to understand the topographic controls on the distribution of Polylepis subsericans treeline forests in the Andes of southern Peru, and the changes in these controls along an elevational gradient. We mapped Polylepis forests in the Cordillera Urubamba, Cusco, using high-resolution aerial images and related forest cover to topographic variables extracted from a digital terrain model (30-m resolution. The variables were selected based on their expected biological relevance for tree growth at high elevations. We constructed logistic regression models of forest cover, separately for each of five 100-m elevational belts. To deal with spatial autocorrelation, models were based on randomized 10% subsampling of the data with 1000 repetitions. The results suggest a consistent shift in topographic preference with elevation, with forests at lower elevations showing a preference for topographically protected sites near rivers and forests at higher elevations being increasingly restricted to north-facing and well-drained sites. Our study offers the first indication of the ability of Andean treeline forests to benefit from the topographic heterogeneity of the high-Andes. Providing that dispersal and establishment are possible, local relocation between microsites could help these forests to persist regionally in spite of changing climatic conditions.

  11. Calculus of the Power Spectral Density of Ultra Wide Band Pulse Position Modulation Signals Coded with Totally Flipped Code

    DURNEA, T. N.

    2009-02-01

    Full Text Available UWB-PPM systems were noted to have a power spectral density (p.s.d. consisting of a continuous portion and a line spectrum, which is composed of energy components placed at discrete frequencies. These components are the major source of interference to narrowband systems operating in the same frequency interval and deny harmless coexistence of UWB-PPM and narrowband systems. A new code denoted as Totally Flipped Code (TFC is applied to them in order to eliminate these discrete spectral components. The coded signal transports the information inside pulse position and will have the amplitude coded to generate a continuous p.s.d. We have designed the code and calculated the power spectral density of the coded signals. The power spectrum has no discrete components and its envelope is largely flat inside the bandwidth with a maximum at its center and a null at D.C. These characteristics make this code suited for implementation in the UWB systems based on PPM-type modulation as it assures a continuous spectrum and keeps PPM modulation performances.

  12. Modern Prejudice and Same-Sex Parenting: Shifting Judgments in Positive and Negative Parenting Situations

    MASSEY, SEAN G.; MERRIWETHER, ANN M.; GARCIA, JUSTIN R.

    2013-01-01

    The current study compares the effects of traditional and modern anti-homosexual prejudice on evaluations of parenting practices of same-sex and opposite-sex couples. Undergraduate university student participants (N = 436) completed measures of traditional and modern anti-homosexual prejudice and responded to a vignette describing a restaurant scene in which parents react to their child’s undesirable behavior. The parents’ sexual orientation and the quality of their parenting (positive or neg...

  13. Theoretical Stark widths and shifts of spectral lines of 2p5nf and 2p55g configurations of Mg III

    Moreno-Díaz, Cristina; Alonso-Medina, Aurelia; Colón, Cristóbal

    2014-01-01

    In this paper, we report theoretical Stark widths and shifts calculated using the Griem semi-empirical approach, which corresponds to 111 spectral lines of Mg III. The values of these Stark broadening parameters of spectral lines that arise from levels of 2p 5 nf and 2p 5 5g configurations of Mg III are presented in the literature for the first time. The aim of this work is to provide values to estimate the electron density of plasma Mg III in astrophysics and industrial applications. The data are presented for the temperatures T = 0.5–10.0 (10 4 K) and for an electron density of 10 17 cm −3 . The matrix of elements used in these calculations has been determined from 23 configurations of Mg III: 2s 2 2p 6 , 2s 2 2p 5 3p, 2s 2 2p 5 4p, 2s 2 2p 5 4f and 2s 2 2p 5 5f for the even parity and 2s 2 2p 5 ns (n = 3–6), 2s 2 2p 5 nd (n = 3–9), 2s 2 2p 5 5g and 2s2p 6 np (n = 3–8) for the odd parity. For the intermediate coupling calculations, we use the standard method of least square fitting from experimental energy levels by means of Cowan’s computer code. Lines with wavelengths of 134.6460, 135.2800, 189.0380, 190.0043, 192.8424, 408.2939 and 409.4375 nm have high probabilities and also have high values of broadening. Therefore, these lines can be used in some applications. A common regularity for the Stark width of the 189.038 nm spectral line of Mg III is discussed. (paper)

  14. Influence of ligand spin-orbit coupling to the sign of the zero-field splitting and pressure-induced spectral shift for ZnS:Mn2+ (bulk/nanocrystal)

    Zhao, M.G.; Lei, Y.

    2004-01-01

    Serious difficulties exist in explaining the zero-field splitting (ZFS) of 3d 5 ions in crystal, with the current crystal-field theory. The calculated cubic ZFS a-value of 3d 5 ion is positive identically. However, K.A. Mueller and W. Low found experimentally that a is negative for some ZnS:Mn 2+ crystals. In this work, an unified explanation is developed for the ZFS, optical spectra and pressure-induced spectral shift for the ZnS:Mn 2+ (bulk/nanocrystal) by considering the influence of the spin-orbit coupling to the ZFS and spectral bands. The excellent agreement between calculation and experiments shows that the above-mentioned difficulties can be removed based on the calculation model proposed by authors. Calculation result shows that there are two kinds of stable electron states with (λ π , λ σ , λ s ) = (0.2713448, -0.1619936, -0.08) and (0.2713448, 0.346885, -0.220), respectively, where (λ π , λ σ , λ s ) denote the mixing coefficients of Mn 2+ - 4S 2- anti-bonding in ZnS:Mn 2+

  15. Application of the finite-element method and the eigenmode expansion method to investigate the periodic and spectral characteristic of discrete phase-shift fiber Bragg grating

    He, Yue-Jing; Hung, Wei-Chih; Syu, Cheng-Jyun

    2017-12-01

    The finite-element method (FEM) and eigenmode expansion method (EEM) were adopted to analyze the guided modes and spectrum of phase-shift fiber Bragg grating at five phase-shift degrees (including zero, 1/4π, 1/2π, 3/4π, and π). In previous studies on optical fiber grating, conventional coupled-mode theory was crucial. This theory contains abstruse knowledge about physics and complex computational processes, and thus is challenging for users. Therefore, a numerical simulation method was coupled with a simple and rigorous design procedure to help beginners and users to overcome difficulty in entering the field; in addition, graphical simulation results were presented. To reduce the difference between the simulated context and the actual context, a perfectly matched layer and perfectly reflecting boundary were added to the FEM and the EEM. When the FEM was used for grid cutting, the object meshing method and the boundary meshing method proposed in this study were used to effectively enhance computational accuracy and substantially reduce the time required for simulation. In summary, users can use the simulation results in this study to easily and rapidly design an optical fiber communication system and optical sensors with spectral characteristics.

  16. Calculation of spectral shifts in UV–visible region and photoresponsive behaviour of fluorinated liquid crystals: Effect of solvent and substituent

    Lakshmi Praveen, P.; Ojha, Durga P.

    2012-01-01

    The photoresponsive behaviour of fluorinated liquid crystals p-phenylene-4-methoxy benzoate-4-trifluoromethylbenzoate (FLUORO1), and 4-propyloxyphenyl-4-(4-trifluoromethylbenzoyloxy) benzoate (FLUORO2) has been systematically investigated using the CNDO/S + CI and INDO/S + CI methods. These methods have been employed to calculate/analyze the spectral shifts, and absorbance measurements in UV–visible region of the systems. The electronic transitions, absorption wavelength, HOMO (highest occupied molecular orbital), and LUMO (lowest unoccupied molecular orbital) energies have been calculated. Further, ultraviolet (UV) stability of the molecules has been discussed in the light of absorption wavelength and electronic transition oscillator strength (f). The effect of different solvent media and substituents on transition energies, oscillator strength, and other absorption parameters have also been reported. The present article provides valuable information regarding enhancing the UV stability of molecules by marinating their conductivity. Highlights: ► The strongest bands of FLUORO molecules can be assigned as π → π ∗ transitions. ► A small red-shift indicates a weak exciton coupling of chromophores. ► No n → π ∗ transition occurs due to the rigidity of the ring system of the molecules. ► The HOMO, LUMO, and E g values have been found to be independent of solvent effect.

  17. Calculation of spectral shifts in UV-visible region and photoresponsive behaviour of fluorinated liquid crystals: Effect of solvent and substituent

    Lakshmi Praveen, P. [Liquid Crystal Research Laboratory, Post-Graduate Department of Physics, Andhra Loyola College, Vijayawada 520 008, A.P. (India); Ojha, Durga P., E-mail: durga_ojha@hotmail.com [Liquid Crystal Research Laboratory, Post-Graduate Department of Physics, Andhra Loyola College, Vijayawada 520 008, A.P. (India)

    2012-08-15

    The photoresponsive behaviour of fluorinated liquid crystals p-phenylene-4-methoxy benzoate-4-trifluoromethylbenzoate (FLUORO1), and 4-propyloxyphenyl-4-(4-trifluoromethylbenzoyloxy) benzoate (FLUORO2) has been systematically investigated using the CNDO/S + CI and INDO/S + CI methods. These methods have been employed to calculate/analyze the spectral shifts, and absorbance measurements in UV-visible region of the systems. The electronic transitions, absorption wavelength, HOMO (highest occupied molecular orbital), and LUMO (lowest unoccupied molecular orbital) energies have been calculated. Further, ultraviolet (UV) stability of the molecules has been discussed in the light of absorption wavelength and electronic transition oscillator strength (f). The effect of different solvent media and substituents on transition energies, oscillator strength, and other absorption parameters have also been reported. The present article provides valuable information regarding enhancing the UV stability of molecules by marinating their conductivity. Highlights: Black-Right-Pointing-Pointer The strongest bands of FLUORO molecules can be assigned as {pi} {yields} {pi}{sup Asterisk-Operator} transitions. Black-Right-Pointing-Pointer A small red-shift indicates a weak exciton coupling of chromophores. Black-Right-Pointing-Pointer No n {yields} {pi}{sup Asterisk-Operator} transition occurs due to the rigidity of the ring system of the molecules. Black-Right-Pointing-Pointer The HOMO, LUMO, and E{sub g} values have been found to be independent of solvent effect.

  18. Unraveling mysteries of personal performance style; biomechanics of left-hand position changes (shifting) in violin performance.

    Visentin, Peter; Li, Shiming; Tardif, Guillaume; Shan, Gongbing

    2015-01-01

    Instrumental music performance ranks among the most complex of learned human behaviors, requiring development of highly nuanced powers of sensory and neural discrimination, intricate motor skills, and adaptive abilities in a temporal activity. Teaching, learning and performing on the violin generally occur within musico-cultural parameters most often transmitted through aural traditions that include both verbal instruction and performance modeling. In most parts of the world, violin is taught in a manner virtually indistinguishable from that used 200 years ago. The current study uses methods from movement science to examine the "how" and "what" of left-hand position changes (shifting), a movement skill essential during violin performance. In doing so, it begins a discussion of artistic individualization in terms of anthropometry, the performer-instrument interface, and the strategic use of motor behaviors. Results based on 540 shifting samples, a case series of 6 professional-level violinists, showed that some elements of the skill were individualized in surprising ways while others were explainable by anthropometry, ergonomics and entrainment. Remarkably, results demonstrated each violinist to have developed an individualized pacing for shifts, a feature that should influence timing effects and prove foundational to aesthetic outcomes during performance. Such results underpin the potential for scientific methodologies to unravel mysteries of performance that are associated with a performer's personal artistic style.

  19. Unraveling mysteries of personal performance style; biomechanics of left-hand position changes (shifting in violin performance

    Peter Visentin

    2015-10-01

    Full Text Available Instrumental music performance ranks among the most complex of learned human behaviors, requiring development of highly nuanced powers of sensory and neural discrimination, intricate motor skills, and adaptive abilities in a temporal activity. Teaching, learning and performing on the violin generally occur within musico-cultural parameters most often transmitted through aural traditions that include both verbal instruction and performance modeling. In most parts of the world, violin is taught in a manner virtually indistinguishable from that used 200 years ago. The current study uses methods from movement science to examine the “how” and “what” of left-hand position changes (shifting, a movement skill essential during violin performance. In doing so, it begins a discussion of artistic individualization in terms of anthropometry, the performer-instrument interface, and the strategic use of motor behaviors. Results based on 540 shifting samples, a case series of 6 professional-level violinists, showed that some elements of the skill were individualized in surprising ways while others were explainable by anthropometry, ergonomics and entrainment. Remarkably, results demonstrated each violinist to have developed an individualized pacing for shifts, a feature that should influence timing effects and prove foundational to aesthetic outcomes during performance. Such results underpin the potential for scientific methodologies to unravel mysteries of performance that are associated with a performer’s personal artistic style.

  20. The spectral positioning algorithm of new spectrum vehicle based on convex programming in wireless sensor network

    Zhang, Yongjun; Lu, Zhixin

    2017-10-01

    Spectrum resources are very precious, so it is increasingly important to locate interference signals rapidly. Convex programming algorithms in wireless sensor networks are often used as localization algorithms. But in view of the traditional convex programming algorithm is too much overlap of wireless sensor nodes that bring low positioning accuracy, the paper proposed a new algorithm. Which is mainly based on the traditional convex programming algorithm, the spectrum car sends unmanned aerial vehicles (uses) that can be used to record data periodically along different trajectories. According to the probability density distribution, the positioning area is segmented to further reduce the location area. Because the algorithm only increases the communication process of the power value of the unknown node and the sensor node, the advantages of the convex programming algorithm are basically preserved to realize the simple and real-time performance. The experimental results show that the improved algorithm has a better positioning accuracy than the original convex programming algorithm.

  1. Changes in the MEG background activity in patients with positive symptoms of schizophrenia: spectral analysis and impact of age

    Escudero, Javier; Ifeachor, Emmanuel; Fernández, Alberto; López-Ibor, Juan José; Hornero, Roberto

    2013-01-01

    The frequency spectrum of the magnetoencephalogram (MEG) background activity was analysed in 15 schizophrenia (SCH) patients with predominant positive symptoms and 17 age-matched healthy control subjects using the following variables: median frequency (MF), spectral entropy (SpecEn) and relative power in delta (RPδ), theta (RPθ), lower alpha (RPα1), upper alpha (RPα2), beta (RPβ) and gamma (RPγ) bands. We found significant differences between the two subject groups in the average level of MF and RPγ in some regions of the scalp. Additionally, the MF, SpecEn, RPβ and RPγ values of SCH patients with positive symptoms had a different dependence on age as compared with the results of control subjects, suggesting that SCH affects the way in which the brain activity evolves with age. Moreover, we also classified the MEG signals by means of a cross-validated feature selection process followed by a logistic regression. The subjects were classified with 71.3% accuracy and an area under the ROC curve of 0.741. Thus, the spectral and classification analysis of the MEG in SCH may provide insights into how this condition affects the brain activity and may help in its early detection. (paper)

  2. Modern Prejudice and Same-Sex Parenting: Shifting Judgments in Positive and Negative Parenting Situations

    MASSEY, SEAN G.; MERRIWETHER, ANN M.; GARCIA, JUSTIN R.

    2013-01-01

    The current study compares the effects of traditional and modern anti-homosexual prejudice on evaluations of parenting practices of same-sex and opposite-sex couples. Undergraduate university student participants (N = 436) completed measures of traditional and modern anti-homosexual prejudice and responded to a vignette describing a restaurant scene in which parents react to their child’s undesirable behavior. The parents’ sexual orientation and the quality of their parenting (positive or negative quality) were varied randomly. It was predicted that participants who score higher in modern prejudice would rate the negative parenting behaviors of same-sex parents more negatively than similar behaviors in opposite-sex parents. It was also predicted that this modern prejudice effect would be most pronounced for male participants. Both hypotheses were supported. PMID:23667347

  3. New SU(1,1) position-dependent effective mass coherent states for a generalized shifted harmonic oscillator

    Yahiaoui, Sid-Ahmed; Bentaiba, Mustapha

    2014-01-01

    A new SU(1,1) position-dependent effective mass coherent states (PDEM CS) related to the shifted harmonic oscillator (SHO) are deduced. This is accomplished by applying a similarity transformation to the generally deformed oscillator algebra (GDOA) generators for PDEM systems and a new set of operators that close the su(1,1) Lie algebra are constructed, being the PDEM CS of the basis for its unitary irreducible representation. From the Lie algebra generators, we evaluate the uncertainty relationship for a position and momentum-like operators in the PDEM CS and show that it is minimized in the sense of Barut–Girardello CS. We prove that the deduced PDEM CS preserve the same analytical form than those of Glauber states. As an illustration of our procedure, we depicted the 2D-probability density in the PDEM CS for SHO with the explicit form of the mass distribution with no singularities. (paper)

  4. Spectral Imaging by Upconversion

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    We present a method to obtain spectrally resolved images using upconversion. By this method an image is spectrally shifted from one spectral region to another wavelength. Since the process is spectrally sensitive it allows for a tailored spectral response. We believe this will allow standard...... silicon based cameras designed for visible/near infrared radiation to be used for spectral images in the mid infrared. This can lead to much lower costs for such imaging devices, and a better performance....

  5. Monte Carlo modelling of a-Si EPID response: The effect of spectral variations with field size and position

    Parent, Laure; Seco, Joao; Evans, Phil M.; Fielding, Andrew; Dance, David R.

    2006-01-01

    This study focused on predicting the electronic portal imaging device (EPID) image of intensity modulated radiation treatment (IMRT) fields in the absence of attenuation material in the beam with Monte Carlo methods. As IMRT treatments consist of a series of segments of various sizes that are not always delivered on the central axis, large spectral variations may be observed between the segments. The effect of these spectral variations on the EPID response was studied with fields of various sizes and off-axis positions. A detailed description of the EPID was implemented in a Monte Carlo model. The EPID model was validated by comparing the EPID output factors for field sizes between 1x1 and 26x26 cm 2 at the isocenter. The Monte Carlo simulations agreed with the measurements to within 1.5%. The Monte Carlo model succeeded in predicting the EPID response at the center of the fields of various sizes and offsets to within 1% of the measurements. Large variations (up to 29%) of the EPID response were observed between the various offsets. The EPID response increased with field size and with field offset for most cases. The Monte Carlo model was then used to predict the image of a simple test IMRT field delivered on the beam axis and with an offset. A variation of EPID response up to 28% was found between the on- and off-axis delivery. Finally, two clinical IMRT fields were simulated and compared to the measurements. For all IMRT fields, simulations and measurements agreed within 3%--0.2 cm for 98% of the pixels. The spectral variations were quantified by extracting from the spectra at the center of the fields the total photon yield (Y total ), the photon yield below 1 MeV (Y low ), and the percentage of photons below 1 MeV (P low ). For the studied cases, a correlation was shown between the EPID response variation and Y total , Y low , and P low

  6. Time-dependent density functional theory for open systems with a positivity-preserving decomposition scheme for environment spectral functions

    Wang, RuLin; Zheng, Xiao; Kwok, YanHo; Xie, Hang; Chen, GuanHua; Yam, ChiYung

    2015-01-01

    Understanding electronic dynamics on material surfaces is fundamentally important for applications including nanoelectronics, inhomogeneous catalysis, and photovoltaics. Practical approaches based on time-dependent density functional theory for open systems have been developed to characterize the dissipative dynamics of electrons in bulk materials. The accuracy and reliability of such approaches depend critically on how the electronic structure and memory effects of surrounding material environment are accounted for. In this work, we develop a novel squared-Lorentzian decomposition scheme, which preserves the positive semi-definiteness of the environment spectral matrix. The resulting electronic dynamics is guaranteed to be both accurate and convergent even in the long-time limit. The long-time stability of electronic dynamics simulation is thus greatly improved within the current decomposition scheme. The validity and usefulness of our new approach are exemplified via two prototypical model systems: quasi-one-dimensional atomic chains and two-dimensional bilayer graphene

  7. Time-dependent density functional theory for open systems with a positivity-preserving decomposition scheme for environment spectral functions.

    Wang, RuLin; Zheng, Xiao; Kwok, YanHo; Xie, Hang; Chen, GuanHua; Yam, ChiYung

    2015-04-14

    Understanding electronic dynamics on material surfaces is fundamentally important for applications including nanoelectronics, inhomogeneous catalysis, and photovoltaics. Practical approaches based on time-dependent density functional theory for open systems have been developed to characterize the dissipative dynamics of electrons in bulk materials. The accuracy and reliability of such approaches depend critically on how the electronic structure and memory effects of surrounding material environment are accounted for. In this work, we develop a novel squared-Lorentzian decomposition scheme, which preserves the positive semi-definiteness of the environment spectral matrix. The resulting electronic dynamics is guaranteed to be both accurate and convergent even in the long-time limit. The long-time stability of electronic dynamics simulation is thus greatly improved within the current decomposition scheme. The validity and usefulness of our new approach are exemplified via two prototypical model systems: quasi-one-dimensional atomic chains and two-dimensional bilayer graphene.

  8. Red light-induced shift of the fluence-response curve for first positive curvature of maize [Zea mays] coleoptiles

    Hofmann, E.; Schäfer, E.

    1987-01-01

    The fluence-response curve for first positive phototropic curvture of dark-grown maize coleoptiles is shifted to ten-fold higher fluences if the coieoptiles are irradiated with red light 2 h prior to the phototropic induction with blue light. Fluence-response curves for this red-induced shift were obtained with unilateral red irradiations 2 h prior to inductive blue pulses of different fluences. They differ significantly depending on whether the red light was given from the same side as or the opposite side to the respective inductive blue pulse, thus demonstrating that the red light effect is a local response of the coleoptile. The fluence-response curves for an inductive blue pulse in the ascending part were compared with those for an inductive blue pulse in the descending part of the fluence-response curve for blue light induced phototropism. They are quite different in threshold of red light sensitivity and shape for irradiations from both the same and the opposite sides. This offers evidence for the hypothesis that at least two different photosystems are involved in phototropism, and that they are modulated differently by a red light preirradiation. All these fluence-response curves indicate that it is possible to increase the response in the coleoptile, if the red light preirradiation is given opposite to the inductive blue pulse. This is supported by blue light fluence-response curves obtained after a weak unilateral red preirradiation. (author)

  9. Spectral shift reactor control method

    Impink, A.J. Jr.

    1981-01-01

    A method of operating a nuclear reactor having a core and coolant displacer elements arranged in the core wherein is established a reator coolant temperature set point at which it is desired to operate said reactor and first reactor coolant temperature band limits are provided within which said set point is located and it is desired to operate said reactor charactrized in that said reactor coolant displacer elements are moved relative to the reactor core for adjusting the volume of reactor coolant in said core as said reactor coolant temperature approaches said first band limits thereby to maintain said reactor coolant temperature near said set point and within said first band limits

  10. Spectral shift reactor control method

    Impink, A.J.

    1982-01-01

    A method of operating a nuclear reactor having a core and coolant displacer elements arranged in the core where there is established a reactor coolant temperature set point at which it is desired to operate the reactor and first reactor coolant temperature band limits within which the set point is characterized. The reactor coolant displacer elements are moved relative to the reactor core for adjusting the volume of reactor coolant in the core as the reactor coolant temperature approaches the first band limits to maintain the reactor coolant temperature near the set point and within the first band limits. The reactivity charges associated with movement of respective coolant displacer element clusters is calculated and compared with a calculated derived reactivity charge in order to select the cluster to be moved. (author)

  11. Did a brief nap break have positive benefits on information processing among nurses working on the first 8-h night shift?

    Chang, Yu-San; Wu, Yu-Hsuan; Lu, Mei Rou; Hsu, Chung-Yao; Liu, Ching-Kuan; Hsu, Chin

    2015-05-01

    Shift workers frequently experience acute sleep deprivation on first night shift. This study compared the efficacy of 30-min nap (between 2 and 3 a.m.) on the visual attention ability of the nurses working at first 8-h night shift at the time of maximum fatigue (between 3 and 4 a.m.). In addition, we measured cognitive function (between 9 and 10 a.m.) in nurses working on daytime shift, which we defined as baseline wakefulness. The results showed that working on the night shift groups was associated with sleep loss, leading to a decrease in visual attention performance compared to the daytime shift group. There was no statistically significant difference in the visual attention performance between those taking and not taking a nap during the night shift, however the effect size was medium in the information process. It was still needed increase sample size to draw the conclusion regarding a 30-min nap break have positive benefits on perceptual speed during the first night shift. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. Pressure-induced basilar membrane position shifts and the stimulus-evoked potentials in the low-frequency region of the guinea pig cochlea

    Fridberger, A; vanMaarseveen, JTPW; Scarfone, E; Ulfendahl, M; Flock, B; Flock, A

    1997-01-01

    We have used the guinea pig isolated temporal bone preparation to investigate changes in the nonlinear properties of the tone-evoked cochlear potentials during reversible step displacements of the basilar membrane towards either the scala tympani or the scala vestibuli. The position shifts were

  13. Position-dependent energy-level shifts of an accelerated atom in the presence of a boundary

    Zhu Zhiying; Yu Hongwei

    2010-01-01

    We consider a uniformly accelerated atom interacting with a vacuum electromagnetic field in the presence of an infinite conducting plane boundary and calculate separately the contributions of vacuum fluctuations and radiation reaction to the atomic energy-level shift. We analyze in detail the behavior of the total energy shift in three different regimes of the distance in both the low-acceleration and high-acceleration limits. Our results show that, in general, an accelerated atom does not behave as if immersed in a thermal bath at the Unruh temperature in terms of the atomic energy-level shifts, and the effect of the acceleration on the atomic energy-level shifts may in principle become appreciable in certain circumstances, although it may not be realistic for actual experimental measurements. We also examine the effects of the acceleration on the level shifts when the acceleration is of the order of the transition frequency of the atom and we find some features which differ from what was obtained in the existing literature.

  14. Effect of input spectrum on the spectral switch characteristics in a white-light Michelson interferometer.

    Brundavanam, Maruthi M; Viswanathan, Nirmal K; Rao, D Narayana

    2009-12-01

    We report here a detailed experimental study to demonstrate the effect of source spectral characteristics such as spectral bandwidth (Deltalambda), peak wavelength (lambda(0)), and shape of the spectrum on the spectral shifts and spectral switches measured due to temporal correlation in a white-light Michelson interferometer operated in the spectral domain. Behavior of the spectral switch characteristics such as the switch position, switch amplitude, and switch symmetry are discussed in detail as a function of optical path difference between the interfering beams. The experimental results are compared with numerical calculations carried out using interference law in the spectral domain with modified source spectral characteristics. On the basis of our results we feel that our study is of critical importance in the selection of source spectral characteristics to further improve the longitudinal resolution or the measurement sensitivity in spectral-domain optical coherence tomography and microscopy.

  15. A unified calculation of the optical spectral band positions and electron paramagnetic resonance spectral data for Yb3+ in InP semiconductor

    Feng Wenlin; Zheng Wenchen; Liu Honggang; Li, X.M.

    2011-01-01

    Highlights: → We found a energy matrix of 4f 13 ion in cubic crystals and external magnetic field. → Optical and EPR data of Yb 3+ : InP are explained by diagonalizing the energy matrix. → Signs of hyperfine structure constants A( 171 Yb 3+ ) and A( 173 Yb 3+ ) are determined. - Abstract: The complete energy matrix for a 4f 13 ion in cubic crystals and under an external magnetic field is established by means of the irreducible tensor operator and/or equivalent operator methods. By diagonalizing the energy matrix, four optical spectrum band positions and three spin-Hamiltonian parameters [g factor and hyperfine structure constants A( 171 Yb 3+ ) and A( 173 Yb 3+ )] for Yb 3+ in InP semiconductor are calculated together. The calculated results are in good agreement with the experimental values. The signs of hyperfine structure constants A( 171 Yb 3+ ) and A( 173 Yb 3+ ) are determined from the calculations. The results are discussed.

  16. Influence of dust particles on the neon spectral line intensities at the uniform positive column of dc discharge at the space apparatus “Plasma Kristall-4”

    Usachev, A. D.; Zobnin, A. V.; Shonenkov, A. V.; Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Fortov, V. E.; Pustyl'nik, M. Y.; Fink, M. A.; Thoma, M. A.; Thomas, H. M.; Padalka, G. I.

    2018-01-01

    Influence of the elongated dust cloud on the intensities of different neon spectral lines in visible and near ir spectral ranges in the uniform positive column has been experimentally investigated using the Russian-European space apparatus “Plasma Kristall-4” (SA PK-4) on board of the International Space Station (ISS). The investigation was performed in the low pressure (0.5 mbar) direct current (dc, 1 mA) gas discharge in neon. Microgravity allowed us to perform experiments with a large dust cloud in the steady-state regime. To avoid the dust cloud drift in the dc electric field a switching dc polarity discharge mode has been applied. During the experiment a dust cloud of 9 mm in diameter in the discharge tube of 30 mm in diameter with the length of about 100 mm has been observed in the steady-state regime. In this regard, the intensities of neon spectral lines corresponding to 3p → 3s electronic transitions have increased by a factor of 1.4 times, while the intensities of neon spectral lines corresponding to 3d → 3p electronic transitions have increased by a factor of 1.6 times. The observed phenomenon is explained on the basis of the Schottky approach by a self-consistent rising dc electric field in the dusty plasma cloud resulting in an increase of the electron temperature.

  17. Efficiency enhancement calculations of state-of-the-art solar cells by luminescent layers with spectral shifting, quantum cutting, and quantum tripling function

    Ten Kate, O.M.; De Jong, M.; Hintzen, H.T.; Van der Kolk, E.

    2013-01-01

    Solar cells of which the efficiency is not limited by the Shockley-Queisser limit can be obtained by integrating a luminescent spectral conversion layer into the cell structure. We have calculated the maximum efficiency of state-of-the-art c-Si, pc-Si, a-Si, CdTe, GaAs, CIS, CIGS, CGS, GaSb, and Ge

  18. A thermalization energy analysis of the threshold voltage shift in amorphous indium gallium zinc oxide thin film transistors under positive gate bias stress

    Niang, K. M.; Flewitt, A. J., E-mail: ajf@eng.cam.ac.uk [Electrical Engineering Division, Cambridge University, J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Barquinha, P. M. C.; Martins, R. F. P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal); Cobb, B. [Holst Centre/TNO, High Tech Campus 31, 5656AE Eindhoven (Netherlands); Powell, M. J. [252, Valley Drive, Kendal LA9 7SL (United Kingdom)

    2016-02-29

    Thin film transistors (TFTs) employing an amorphous indium gallium zinc oxide (a-IGZO) channel layer exhibit a positive shift in the threshold voltage under the application of positive gate bias stress (PBS). The time and temperature dependence of the threshold voltage shift was measured and analysed using the thermalization energy concept. The peak energy barrier to defect conversion is extracted to be 0.75 eV and the attempt-to-escape frequency is extracted to be 10{sup 7} s{sup −1}. These values are in remarkable agreement with measurements in a-IGZO TFTs under negative gate bias illumination stress (NBIS) reported recently (Flewitt and Powell, J. Appl. Phys. 115, 134501 (2014)). This suggests that the same physical process is responsible for both PBS and NBIS, and supports the oxygen vacancy defect migration model that the authors have previously proposed.

  19. Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C

    Stefanikova, E.; Frassinetti, L.; Saarelma, S.; Loarte, A.; Nunes, I.; Garzotti, L.; Lomas, P.; Rimini, F.; Drewelow, P.; Kruezi, U.; Lomanowski, B.; de la Luna, E.; Meneses, L.; Peterka, M.; Viola, B.; Giroud, C.; Maggi, C.; contributors, JET

    2018-05-01

    The electron temperature and density pedestals tend to vary in their relative radial positions, as observed in DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) and ASDEX Upgrade (Dunne et al 2017 Plasma Phys. Control. Fusion 59 14017). This so-called relative shift has an impact on the pedestal magnetohydrodynamic (MHD) stability and hence on the pedestal height (Osborne et al 2015 Nucl. Fusion 55 063018). The present work studies the effect of the relative shift on pedestal stability of JET ITER-like wall (JET-ILW) baseline low triangularity (δ) unseeded plasmas, and similar JET-C discharges. As shown in this paper, the increase of the pedestal relative shift is correlated with the reduction of the normalized pressure gradient, therefore playing a strong role in pedestal stability. Furthermore, JET-ILW tends to have a larger relative shift compared to JET carbon wall (JET-C), suggesting a possible role of the plasma facing materials in affecting the density profile location. Experimental results are then compared with stability analysis performed in terms of the peeling-ballooning model and with pedestal predictive model EUROPED (Saarelma et al 2017 Plasma Phys. Control. Fusion). Stability analysis is consistent with the experimental findings, showing an improvement of the pedestal stability, when the relative shift is reduced. This has been ascribed mainly to the increase of the edge bootstrap current, and to minor effects related to the increase of the pedestal pressure gradient and narrowing of the pedestal pressure width. Pedestal predictive model EUROPED shows a qualitative agreement with experiment, especially for low values of the relative shift.

  20. Infrastructure and automobile shifts: positioning transit to reduce life-cycle environmental impacts for urban sustainability goals

    Chester, Mikhail; Pincetl, Stephanie; Elizabeth, Zoe; Eisenstein, William; Matute, Juan

    2013-01-01

    Public transportation systems are often part of strategies to reduce urban environmental impacts from passenger transportation, yet comprehensive energy and environmental life-cycle measures, including upfront infrastructure effects and indirect and supply chain processes, are rarely considered. Using the new bus rapid transit and light rail lines in Los Angeles, near-term and long-term life-cycle impact assessments are developed, including consideration of reduced automobile travel. Energy consumption and emissions of greenhouse gases and criteria pollutants are assessed, as well the potential for smog and respiratory impacts. Results show that life-cycle infrastructure, vehicle, and energy production components significantly increase the footprint of each mode (by 48–100% for energy and greenhouse gases, and up to 6200% for environmental impacts), and emerging technologies and renewable electricity standards will significantly reduce impacts. Life-cycle results are identified as either local (in Los Angeles) or remote, and show how the decision to build and operate a transit system in a city produces environmental impacts far outside of geopolitical boundaries. Ensuring shifts of between 20–30% of transit riders from automobiles will result in passenger transportation greenhouse gas reductions for the city, and the larger the shift, the quicker the payback, which should be considered for time-specific environmental goals. (letter)

  1. Infrastructure and automobile shifts: positioning transit to reduce life-cycle environmental impacts for urban sustainability goals

    Chester, Mikhail; Pincetl, Stephanie; Elizabeth, Zoe; Eisenstein, William; Matute, Juan

    2013-03-01

    Public transportation systems are often part of strategies to reduce urban environmental impacts from passenger transportation, yet comprehensive energy and environmental life-cycle measures, including upfront infrastructure effects and indirect and supply chain processes, are rarely considered. Using the new bus rapid transit and light rail lines in Los Angeles, near-term and long-term life-cycle impact assessments are developed, including consideration of reduced automobile travel. Energy consumption and emissions of greenhouse gases and criteria pollutants are assessed, as well the potential for smog and respiratory impacts. Results show that life-cycle infrastructure, vehicle, and energy production components significantly increase the footprint of each mode (by 48-100% for energy and greenhouse gases, and up to 6200% for environmental impacts), and emerging technologies and renewable electricity standards will significantly reduce impacts. Life-cycle results are identified as either local (in Los Angeles) or remote, and show how the decision to build and operate a transit system in a city produces environmental impacts far outside of geopolitical boundaries. Ensuring shifts of between 20-30% of transit riders from automobiles will result in passenger transportation greenhouse gas reductions for the city, and the larger the shift, the quicker the payback, which should be considered for time-specific environmental goals.

  2. Application of MCD spectroscopy and TD-DFT to a highly non-planar porphyrinoid ring system. New insights on red-shifted porphyrinoid spectral bands.

    Mack, John; Asano, Yoshiaki; Kobayashi, Nagao; Stillman, Martin J

    2005-12-21

    The first magnetic circular dichroism (MCD) spectra are reported for tetraphenyltetraacenaphthoporphyrin (TPTANP). The impact on the electronic structure of steric interactions between the fused acenaphthalene rings and the meso-tetraphenyl substituents is explored based on an analysis of the optical spectra of the Zn(II) complex (ZnTPTANP) and the free base dication species ([H4TPTANP]2+). In the case of ZnTPTANP, significant folding of the porphyrinoid ligand induces a highly unusual MCD-sign reversal providing the first direct spectroscopic evidence of ligand nonplanarity. Density functional theory (DFT) geometry optimizations for a wide range of Zn(II) porphyrinoids based on the B3LYP functional and TD-DFT calculations of the associated UV-visible absorption spectra are reported, allowing a complete assessment of the MCD data. TPTANP complexes are found to fall into a class of cyclic polyenes, termed as soft MCD chromophores by Michl (J. Pure Appl. Chem. 1980, 52, 1549.), since the signs of the Faraday A1 terms observed in the MCD spectrum are highly sensitive to slight structural changes. The origin of an unusually large red shift of the main B (or Soret) band of MTPTANP (the most red shifted ever reported for fused-ring-expanded metal porphines) and of similar red shifts observed in the spectra of other peripherally crowded porphyrinoid complexes is also explored and explained on this basis.

  3. Measurement of position dependence of spectral distribution in primary X-ray beam of CT system using compton spectroscopy

    Matsumoto, Masao; Maeda, Koji; Maeda, Koji

    2005-01-01

    Our purpose is to acquire the diagnostic x-ray spectra of the CT system easily under clinical conditions by Compton scatter spectroscopy using a high resolution Schottky CdTe detector recently developed and to estimate the quality and quantity of these spectra compared the relative exposure measured using an ionization chamber with curves measured by the reconstructed spectra. Although the spectral broadening and the fluctuation were slightly shown, the errors of the relative exposure were under 10%. Though the experimental arrangement of this method is so easy and reconstructed algorithm is simple, these results suggested that this method is little influenced by the variation of dose rates or property of the incident x rays. We therefore propose that the Compton scatter spectroscopy with the newly developed Schottky CdTe detector is suitable for measuring the diagnostic x-ray spectra of the CT system under the clinical conditions and useful for quality assurance and quality control of the clinical x-ray CT system. (author)

  4. Signal Processing of Ground Penetrating Radar Using Spectral Estimation Techniques to Estimate the Position of Buried Targets

    Shanker Man Shrestha

    2003-11-01

    Full Text Available Super-resolution is very important for the signal processing of GPR (ground penetration radar to resolve closely buried targets. However, it is not easy to get high resolution as GPR signals are very weak and enveloped by the noise. The MUSIC (multiple signal classification algorithm, which is well known for its super-resolution capacity, has been implemented for signal and image processing of GPR. In addition, conventional spectral estimation technique, FFT (fast Fourier transform, has also been implemented for high-precision receiving signal level. In this paper, we propose CPM (combined processing method, which combines time domain response of MUSIC algorithm and conventional IFFT (inverse fast Fourier transform to obtain a super-resolution and high-precision signal level. In order to support the proposal, detailed simulation was performed analyzing SNR (signal-to-noise ratio. Moreover, a field experiment at a research field and a laboratory experiment at the University of Electro-Communications, Tokyo, were also performed for thorough investigation and supported the proposed method. All the simulation and experimental results are presented.

  5. A Spectral Active Material Interference in the Electrical Conductivity of the Internal Electrolyte and the Potential Shift of the Ag/AgCl Electrode

    Yun, Myung Hee; Yeon, Jei Won; Hwang, Jae Sik; Song, Kyu Seok

    2009-01-01

    The Ag/AgCl electrode is a type of reference electrode, commonly used in electrochemical measurements, because it is simple and stable. For these reasons, the Ag/AgCl electrode has long been used to provide a reliable potential monitoring of ions in a solution. However, when a reference electrode is used in an aqueous solution containing a very low electrolyte for a long period of time, this could cause a considerable potential shift of the reference electrode due to a dilution of the internal electrolyte. If the potential of the reference electrode shifts, undesirable conditions may occur. Therefore, many studies have been applied to improve the long-term performance of the reference electrode. However, these attempts have not completely resolved the problem of an electrolyte dilution by the test solution. In the present study, we developed a creative technique to correct the concentration change of the internal electrolyte by a long-term exposure of the Ag/AgCl electrode in very dilute solutions. We measured the electrical conductivity and UV/VIS absorbance of the internal electrolyte. From these measurements, we observed the linear relationship between KCl concentration and the potential of the Ag/AgCl electrode. In order to accelerate the diffusion of the internal electrolyte into the test solution, an Ag/AgCl electrode with a tiny perforation was used. We confirmed the feasibility of the creative calibration technique

  6. Spectral detection of near-surface moisture content and water-table position in northern peatland ecosystems

    Karl M. Meingast; Michael J. Falkowski; Evan S. Kane; Lynette R. Potvin; Brian W. Benscoter; Alistair M.S. Smith; Laura L. Bourgeau-Chavez; Mary Ellen. Miller

    2014-01-01

    Wildland fire occurrence has been increasing in peatland ecosystems during recent decades. As such, there is a need for broadly applicable tools to detect and monitor controls on combustion such as surface peat moisture and water-table position. A field portable spectroradiometer was used to measure surface reflectance of two Sphagnum moss-dominated...

  7. Is gingival recession a consequence of an orthodontic tooth size and/or tooth position discrepancy? "A paradigm shift".

    Richman, Colin

    2011-01-01

    Gingival recession (GR) is a commonly observed dental lesion. The underlying etiology has not been clearly identified, although several theories have been suggested. Tooth crowding or tooth malalignment is also frequently observed, with both conditions appearing to be more prevalent in developed countries with heterogeneous populations. A total of 25 consecutively treated patients representing 72 teeth and demonstrating facial clinical GR of > 3 mm were examined clinically, photographically, and with 3-dimensional radiology using conebeam computed tomography. All examined teeth presented with normal interproximal probing depths and attachment levels (teeth demonstrating > 3 mm of GR presented with significantly prominent facial tooth contours and associated alveolar bone dehiscences. Most involved teeth presented with their root structures extending beyond the facial alveolar bony housing (fenestrations). This represents a discrepancy between tooth size and alveolar bone dimensions in the buccolingual, axial, and sagittal orientation. Fewer involved teeth were malpositioned toward the buccal aspect. Both conditions were associated with facial alveolar bone dehiscences and associated GR. This study suggests tooth volume and/or tooth position within the alveolar bony housing strongly correlate with GR. All nonperiodontitis-involved teeth with GR were associated with either wider teeth or facially aligned teeth. However, it is emphasized that all facially aligned teeth, or "larger" teeth, do not necessarily present with GR. Based on these findings, the radiographic-supporting bone index is proposed. This index should facilitate appropriate evaluation of the alveolar bone supporting the mucogingival complex, both on the facial and lingual aspect of teeth. Further investigations are needed to support these preliminary data.

  8. A Tree-Ring Based Reconstruction (1725-present) of the Position of the Summer North Atlantic Jet Shows a 20th Century Northward Shift

    Trouet, V.; Babst, F.

    2014-12-01

    The position and strength of the Northern Hemisphere polar jet are important modulators of mid-latitude weather extremes and the societal, ecosystem, and economic damage related to them. The position of the North Atlantic jet (NAJ) controls the location of the Atlantic storm track and anomalies in the NAJ position have been related to temperature and precipitation extremes over Europe. In summer, a southern NAJ regime can result in floods in the British Isles (BRIT) and increasing odds of heat waves in the northeastern Mediterranean (NEMED). Variability in the amplitude and speed of the Northern Hemisphere jet stream is hotly debated as a potential mechanism linking recent mid-latitude weather extremes to anthropogenic warming. However, the hypothesis of jet stream variability as a possible mechanism linking Arctic amplification to mid-latitude weather extremes is largely based on data sets with limited temporal extent that do not warrant robust results from a statistical significance perspective. Here, we combined two summer temperature-sensitive tree-ring records from BRIT and NEMED to reconstruct interannual variability in the latitudinal position of the summer NAJ back to 1725. The two well-replicated temperature proxies counter-correlate significantly over the full period and thus illustrate the temperature dipole generated by anomalous NAJ positions. Positive extremes in the NAJ reconstruction correspond to heatwaves recorded in the historical Central England temperature record and negative extremes correspond to reconstructed fire years in Greece. The reconstruction shows a northward shift in the latitudinal NAJ position since the 1930s that is most pronounced in the northern NAJ extremes, suggesting a more frequent occurrence of BRIT hot summers in the 20th century compared to previous centuries.

  9. Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelength-sensitive opsin 1) are associated with eye length and photic niche evolution.

    Emerling, Christopher A; Huynh, Hieu T; Nguyen, Minh A; Meredith, Robert W; Springer, Mark S

    2015-11-22

    Retinal opsin photopigments initiate mammalian vision when stimulated by light. Most mammals possess a short wavelength-sensitive opsin 1 (SWS1) pigment that is primarily sensitive to either ultraviolet or violet light, leading to variation in colour perception across species. Despite knowledge of both ultraviolet- and violet-sensitive SWS1 classes in mammals for 25 years, the adaptive significance of this variation has not been subjected to hypothesis testing, resulting in minimal understanding of the basis for mammalian SWS1 spectral tuning evolution. Here, we gathered data on SWS1 for 403 mammal species, including novel SWS1 sequences for 97 species. Ancestral sequence reconstructions suggest that the most recent common ancestor of Theria possessed an ultraviolet SWS1 pigment, and that violet-sensitive pigments evolved at least 12 times in mammalian history. We also observed that ultraviolet pigments, previously considered to be a rarity, are common in mammals. We then used phylogenetic comparative methods to test the hypotheses that the evolution of violet-sensitive SWS1 is associated with increased light exposure, extended longevity and longer eye length. We discovered that diurnal mammals and species with longer eyes are more likely to have violet-sensitive pigments and less likely to possess UV-sensitive pigments. We hypothesize that (i) as mammals evolved larger body sizes, they evolved longer eyes, which limited transmittance of ultraviolet light to the retina due to an increase in Rayleigh scattering, and (ii) as mammals began to invade diurnal temporal niches, they evolved lenses with low UV transmittance to reduce chromatic aberration and/or photo-oxidative damage. © 2015 The Author(s).

  10. Simultaneous resolution of spectral and temporal properties of UV and visible fluorescence using single-photon counting with a position-sensitive detector

    Kelly, L.A.; Trunk, J.G.; Polewski, K.; Sutherland, J.C.

    1995-01-01

    A new fluorescence spectrometer has been assembled at the U9B beamline of the National Synchrotron Light Source to allow simultaneous multiwavelength and time-resolved fluorescence detection, as well as spatial imaging of the sample fluorescence. The spectrometer employs monochromatized, tunable UV and visible excitation light from a synchrotron bending magnet and an imaging spectrograph equipped with a single-photon sensitive emission detector. The detector is comprised of microchannel plates in series, with a resistive anode for encoding the position of the photon-derived current. The centroid position of the photon-induced electron cascade is derived in a position analyzer from the four signals measured at the corners of the resistive anode. Spectral information is obtained by dispersing the fluorescence spectrum across one dimension of the detector photocathode. Timing information is obtained by monitoring the voltage divider circuit at the last MCP detector. The signal from the MCP is used as a ''start'' signal to perform a time-correlated single photon counting experiment. The analog signal representing the position, and hence wavelength, is digitized concomitantly with the start/stop time difference and stored in the two-dimensional histogramming memory of a multiparameter analyzer

  11. Structural origin of Si-2p core-level shifts from Si(100)-c[4x2] surface: A spectral x-ray photoelectron diffraction study

    Chen, X.; Tonner, B.P. [Univ. of Wisconsin, Milwaukee, WI (United States); Denlinger, J. [Univ. of Wisconsin, Milwaukee, WI (United States)][Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    The authors have performed angle-resolved x-ray photoelectron diffraction (XPD) from a Si(100)-c(4x2) surface to study the structural origin of Si-2p core-level shifts. In the experiment, the highly resolved surface Si-2p core-level spectra were measured as a fine grid of hemisphere and photon energies, using the SpectroMicroscopy Facility {open_quotes}ultraESCA{close_quotes} instrument. By carefully decomposing the spectra into several surface peaks, the authors are able to obtain surface-atom resolved XPD patterns. Using a multiple scattering analysis, they derived a detailed atomic model for the Si(100)-c(4x2) surface. In this model, the asymmetric dimers were found tilted by 11.5 plus/minus 2.0 degrees with bond length of 2.32 plus/minus 0.05{angstrom}. By matching model XPD patterns to experiment, the authors can identify which atoms in the reconstructed surface are responsible for specific photoemission lines in the 2p spectrum.

  12. ESCADT: a FORTRAN code for computing the positions and areas of x-ray photoelectron spectral peaks

    Cox, L.E.

    1979-09-01

    Program ESCADT uses least-squares-derived convoluting numbers to smooth and differentiate x-ray photoelectron spectra. Peak maxima are located by finding zero crossings of the first derivative and refined using a cubic polynomial fitting procedure. Background points are located using the product of the absolute value of the first derivative and the smoothed ordinate value. Peak areas, using both linear and scattered electron backgrounds, are computed. Spectra are corrected for changes in instrument sensitivity and energy calibration with gold-standard data retrieved from a disk file. Five determinations of the gold 4f peak positions yielded standard deviations of 0.011 and 0.031 eV for the 4f/sub 7/2/ and 4f/sub 5/2/ peaks, respectively. The relative standard deviation for the computed areas was 0.85%

  13. The STARK-B database VAMDC node: a repository for spectral line broadening and shifts due to collisions with charged particles

    Sahal-Bréchot, S.; Dimitrijević, M. S.; Moreau, N.; Ben Nessib, N.

    2015-05-01

    Accurate spectroscopic diagnostics and modeling require the knowledge of numerous collisional line profiles. Access to such data via an online database has become indispensable. The STARK-B database is aimed at meeting these needs for widths and shifts of isolated lines of neutral and ionized elements due to electron and ion impacts. This database of the Paris Observatory is a result of scientific cooperation between S Sahal-Bréchot (LERMA) and M S Dimitrijević (AOB). Access to it is free, and it was opened online at the end of 2008. STARK-B is a node of the Virtual Atomic and Molecular Data Centre (VAMDC) and thus complies with VAMDC and Virtual Observatory standards. VAMDC is a European Union-funded collaboration among groups involved in the generation and use of interoperable atomic and molecular data. STARK-B now contains all our semiclassical-perturbation (SCP) calculated data for more than 123 neutral or ionized elements as published in international refereed journals. It is devoted to modeling and spectroscopic diagnostics of stellar atmospheres and envelopes, laboratory plasmas, laser equipment, and technological plasmas. Hence, the range of temperatures and densities covered by the tables is broad and depends on the ionization degree of the radiating atom. The modified semiempirical (MSE) results of calculations have begun to be implemented. In this paper, we highlight the key points of the method and the assumptions used in the calculations, which have lately been revisited. Then we present the database and its recent developments, as well as our ongoing work and our plans for the future.

  14. The STARK-B database VAMDC node: a repository for spectral line broadening and shifts due to collisions with charged particles

    Sahal-Bréchot, S; Moreau, N; Dimitrijević, M S; Nessib, N Ben

    2015-01-01

    Accurate spectroscopic diagnostics and modeling require the knowledge of numerous collisional line profiles. Access to such data via an online database has become indispensable. The STARK-B database is aimed at meeting these needs for widths and shifts of isolated lines of neutral and ionized elements due to electron and ion impacts. This database of the Paris Observatory is a result of scientific cooperation between S Sahal-Bréchot (LERMA) and M S Dimitrijević (AOB). Access to it is free, and it was opened online at the end of 2008. STARK-B is a node of the Virtual Atomic and Molecular Data Centre (VAMDC) and thus complies with VAMDC and Virtual Observatory standards. VAMDC is a European Union-funded collaboration among groups involved in the generation and use of interoperable atomic and molecular data. STARK-B now contains all our semiclassical-perturbation (SCP) calculated data for more than 123 neutral or ionized elements as published in international refereed journals. It is devoted to modeling and spectroscopic diagnostics of stellar atmospheres and envelopes, laboratory plasmas, laser equipment, and technological plasmas. Hence, the range of temperatures and densities covered by the tables is broad and depends on the ionization degree of the radiating atom. The modified semiempirical (MSE) results of calculations have begun to be implemented. In this paper, we highlight the key points of the method and the assumptions used in the calculations, which have lately been revisited. Then we present the database and its recent developments, as well as our ongoing work and our plans for the future. (paper)

  15. SHIFTING POSITIONS ON HOPE VALUE

    Grzesik Chris

    2017-09-01

    Full Text Available The aim of this article is to shed some light on the difficulty, and at the same time, the unavoidable change towards the embracing by valuers in Poland, of one of the most fundamental principles of property valuation, being “highest and best use” and “hope value”. Both are inherently linked to the interpretation of “market value”. The article offers a detailed analysis of international practice and the most important developments concerning professional standards for property valuers in Poland. The considerations presented herein focus mostly on issues arising out of the interpretation of “market value”. While the legal wording of its Polish definition could be considered similar to the one presented in internationally recognised valuation standards, Polish practice concerning assumptions about the use of a property at the date of valuation is very different.

  16. Shift Colors

    Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

  17. Quantum-mechanical vs. semi-classical spectral-line widths and shifts from the line core in the non-impact region for the Ar-perturbed/ K-radiator system

    Kreye, W.C.

    2007-01-01

    New quantum-mechanical (QM) and semi-classical (SC) shifts (d's) and widths (HWHM's, w's) were measured from the line core of computed full spectral-line shapes for the Ar-perturbed/K-radiator system (K/Ar). The initial state of our model was based on a 4p 2 P 3/2,1/2 pseudo-potential for the K/Ar system, and the final state on a zero potential. The Fourier transform of the line shape formed the basis for the computations. Excellent agreement was found between the QM and SC values of d and of w in a high-pressure (P) non-impact region, which was characterized by a √P dependence of w and a P dependence of d. These agreements were shown to be another example of a correspondence between classical (SC) quantities and QM quantities in the limit of large quantum numbers. Typically at P=1x10 6 Torr and T=400 K, w QM =448 cm -1 and w SC =479 cm -1 , where the deviation from the mean is ±3.3%. Also, d QM =-3815 cm -1 and d SC =-3716 cm -1 , where the deviation from the mean is ±1.3%. A new general method was formulated which yielded a definite pressure P 0 , which was defined as an upper limit to the low-pressure impact approximation and a lower limit to the non-impact region

  18. Impact of Compression Stockings vs. Continuous Positive Airway Pressure on Overnight Fluid Shift and Obstructive Sleep Apnea among Patients on Hemodialysis

    Bruno C. Silva

    2017-05-01

    Full Text Available IntroductionObstructive sleep apnea (OSA is common in edematous states, notably in hemodialysis patients. In this population, overnight fluid shift can play an important role on the pathogenesis of OSA. The effect of compression stockings (CS and continuous positive airway pressure (CPAP on fluid shift is barely known. We compared the effects of CS and CPAP on fluid dynamics in a sample of patients with OSA in hemodialysis, through a randomized crossover study.MethodsEach participant performed polysomnography (PSG at baseline, during CPAP titration, and after 1 week of wearing CS. Neck circumference (NC and segmental bioelectrical impedance were done before and after PSG.ResultsFourteen patients were studied (53 ± 9 years; 57% men; body mass index 29.7 ± 6.8 kg/m2. Apnea–hypopnea index (AHI decreased from 20.8 (14.2; 39.6 at baseline to 7.9 (2.8; 25.4 during CPAP titration and to 16.7 (3.5; 28.9 events/h after wearing CS (CPAP vs. baseline, p = 0.004; CS vs. baseline, p = 0.017; and CPAP vs. CS, p = 0.017. Nocturnal intracellular trunk water was higher after wearing CS in comparison to baseline and CPAP (p = 0.03. CS reduced the fluid accumulated in lower limbs during the day, although not significantly. Overnight fluid shift at baseline, CPAP, and CS was −183 ± 72, −343 ± 220, and −290 ± 213 ml, respectively (p = 0.006. Overnight NC increased at baseline (0.7 ± 0.4 cm, decreased after CPAP (−1.0 ± 0.4 cm, and while wearing CS (−0.4 ± 0.8 cm (CPAP vs. baseline, p < 0.0001; CS vs. baseline, p = 0.001; CPAP vs. CS, p = 0.01.ConclusionCS reduced AHI by avoiding fluid retention in the legs, favoring accumulation of water in the intracellular component of the trunk, thus avoiding fluid shift to reach the neck. CPAP improved OSA by exerting local pressure on upper airway, with no impact on fluid redistribution. CPAP performed significantly better than CS

  19. Spectral signatures of chirality

    Pedersen, Jesper Goor; Mortensen, Asger

    2009-01-01

    We present a new way of measuring chirality, via the spectral shift of photonic band gaps in one-dimensional structures. We derive an explicit mapping of the problem of oblique incidence of circularly polarized light on a chiral one-dimensional photonic crystal with negligible index contrast...... to the formally equivalent problem of linearly polarized light incident on-axis on a non-chiral structure with index contrast. We derive analytical expressions for the first-order shifts of the band gaps for negligible index contrast. These are modified to give good approximations to the band gap shifts also...

  20. Diffractive centrosymmetric 3D-transmission phase gratings positioned at the image plane of optical systems transform lightlike 4D-WORLD as tunable resonators into spectral metrics...

    Lauinger, Norbert

    1999-08-01

    Diffractive 3D phase gratings of spherical scatterers dense in hexagonal packing geometry represent adaptively tunable 4D-spatiotemporal filters with trichromatic resonance in visible spectrum. They are described in the (lambda) - chromatic and the reciprocal (nu) -aspects by reciprocal geometric translations of the lightlike Pythagoras theorem, and by the direction cosine for double cones. The most elementary resonance condition in the lightlike Pythagoras theorem is given by the transformation of the grating constants gx, gy, gz of the hexagonal 3D grating to (lambda) h1h2h3 equals (lambda) 111 with cos (alpha) equals 0.5. Through normalization of the chromaticity in the von Laue-interferences to (lambda) 111, the (nu) (lambda) equals (lambda) h1h2h3/(lambda) 111-factor of phase velocity becomes the crucial resonance factor, the 'regulating device' of the spatiotemporal interaction between 3D grating and light, space and time. In the reciprocal space equal/unequal weights and times in spectral metrics result at positions of interference maxima defined by hyperbolas and circles. A database becomes built up by optical interference for trichromatic image preprocessing, motion detection in vector space, multiple range data analysis, patchwide multiple correlations in the spatial frequency spectrum, etc.

  1. Bidirectional soliton spectral tunneling effects in the regime of optical event horizon

    Gu, Jie; Guo, Hairun; Wang, Shaofei

    2015-01-01

    We study the cross-phase-modulation-induced soliton spectral shifting in the regime of the optical event horizon. The perturbed soliton to either red-shifting or blue-shifting is controllable, which could evoke bidirectional soliton spectral tunneling effects.......We study the cross-phase-modulation-induced soliton spectral shifting in the regime of the optical event horizon. The perturbed soliton to either red-shifting or blue-shifting is controllable, which could evoke bidirectional soliton spectral tunneling effects....

  2. Reconstruction of precipitation variability in the Strait of Yucatan associated with latitudinal shifts in the position of the Intertropical Convergence Zone since the Last Glacial Maximum

    Staines-Urías, Francisca; Seidenkrantz, Marit-Solveig; Fischel, Andrea; Kuijpers, Antoon

    2017-04-01

    . Notably, records of sea-surface temperature from the Caribbean indicate similar variability, with among others, colder than present conditions in the early Holocene indicating a more northerly mean ITCZ position, followed by warmer surface waters and a weaker tradewind associated with a southward displacement of the ITCZ, further illustrating the strong link between precipitation variability and oceanographic conditions in the region. After 5 cal ka BP, Ti and Fe values remain fairly stable at an intermediate level until shortly after 2 cal ka BP, when a sudden increase in Fe content is observed. At this time, a significant increase in precipitation has also been inferred from the δ18O signal of ostracods and gastropods in lake sediments from the Yucatan Peninsula and a stalagmite δ18O monsoon reconstruction from mainland Mexico. The drastic increment in Fe content also marks the beginning of a shift towards rapidly decreasing Ti and Fe values, suggesting an increasingly drier climate. Decrease inland runoff/precipitation during the late Holocene has also been observed in stalagmite and lacustrine δ18O signals from nearby locations, altogether indicating a southward displacement of the ITCZ.

  3. Determination of accurate 1H positions of an alanine tripeptide with anti-parallel and parallel β-sheet structures by high resolution 1H solid state NMR and GIPAW chemical shift calculation.

    Yazawa, Koji; Suzuki, Furitsu; Nishiyama, Yusuke; Ohata, Takuya; Aoki, Akihiro; Nishimura, Katsuyuki; Kaji, Hironori; Shimizu, Tadashi; Asakura, Tetsuo

    2012-11-25

    The accurate (1)H positions of alanine tripeptide, A(3), with anti-parallel and parallel β-sheet structures could be determined by highly resolved (1)H DQMAS solid-state NMR spectra and (1)H chemical shift calculation with gauge-including projector augmented wave calculations.

  4. GOSAT-2014 methane spectral line list

    Nikitin, A.V.; Lyulin, O.M.; Mikhailenko, S.N.; Perevalov, V.I.; Filippov, N.N.; Grigoriev, I.M.; Morino, I.; Yoshida, Y.; Matsunaga, T.

    2015-01-01

    The updated methane spectral line list GOSAT-2014 for the 5550–6240 cm −1 region with the intensity cutoff of 5×10 –25 cm/molecule at 296 K is presented. The line list is based on the extensive measurements of the methane spectral line parameters performed at different temperatures and pressures of methane without and with buffer gases N 2 , O 2 and air. It contains the following spectral line parameters of about 12150 transitions: line position, line intensity, energy of lower state, air-induced and self-pressure-induced broadening and shift coefficients and temperature exponent of air-broadening coefficient. The accuracy of the line positions and intensities are considerably improved in comparison with the previous version GOSAT-2009. The improvement of the line list is done mainly due to the involving to the line position and intensity retrieval of six new spectra recorded with short path way (8.75 cm). The air-broadening and air-shift coefficients for the J-manifolds of the 2ν 3 (F 2 ) band are refitted using the new more precise values of the line positions and intensities. The line assignment is considerably extended. The lower state J-value was assigned to 6397 lines representing 94.4% of integrated intensity of the considering wavenumber region. The complete assignment was done for 2750 lines. - Highlights: • The upgrade of the GOSAT methane line list in the 5550–6240 cm −1 region is done. • 12,146 experimental methane line positions and intensities are retrieved. • 6376 lower energy levels for methane lines are determined

  5. Shifting Attention

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  6. Magnitude of shift of tumor position as a function of moderated deep inspiration breath-hold: An analysis of pooled data of lung patients with active breath control in image-guided radiotherapy

    Muralidhar K

    2008-01-01

    Full Text Available The purpose of this study was to evaluate the reproducibility and magnitude of shift of tumor position by using active breathing control and iView-GT for patients with lung cancer with moderate deep-inspiration breath-hold (mDIBH technique. Eight patients with 10 lung tumors were studied. CT scans were performed in the breath-holding phase. Moderate deep-inspiration breath-hold under spirometer-based monitoring system was used. Few important bony anatomic details were delineated by the radiation oncologist. To evaluate the interbreath-hold reproducibility of the tumor position, we compared the digital reconstruction radiographs (DRRs from planning system with the DRRs from the iView-GT in the machine room. We measured the shift in x, y, and z directions. The reproducibility was defined as the difference between the bony landmarks from the DRR of the planning system and those from the DRR of the iView-GT. The maximum shift of the tumor position was 3.2 mm, 3.0 mm, and 2.9 mm in the longitudinal, lateral, and vertical directions. In conclusion, the moderated deep-inspiration breath-hold method using a spirometer is feasible, with relatively good reproducibility of the tumor position for image-guided radiotherapy in lung cancers.

  7. Spectral stratigraphy

    Lang, Harold R.

    1991-01-01

    A new approach to stratigraphic analysis is described which uses photogeologic and spectral interpretation of multispectral remote sensing data combined with topographic information to determine the attitude, thickness, and lithology of strata exposed at the surface. The new stratigraphic procedure is illustrated by examples in the literature. The published results demonstrate the potential of spectral stratigraphy for mapping strata, determining dip and strike, measuring and correlating stratigraphic sequences, defining lithofacies, mapping biofacies, and interpreting geological structures.

  8. Chemical shift imaging: a review

    Brateman, L.

    1986-01-01

    Chemical shift is the phenomenon that is seen when an isotope possessing a nuclear magnetic dipole moment resonates at a spectrum of resonance frequencies in a given magnetic field. These resonance frequencies, or chemical shifts, depend on the chemical environments of particular nuclei. Mapping the spatial distribution of nuclei associated with a particular chemical shift (e.g., hydrogen nuclei associated with water molecules or with lipid groups) is called chemical shift imaging. Several techniques of proton chemical shift imaging that have been applied in vivo are presented, and their clinical findings are reported and summarized. Acquiring high-resolution spectra for large numbers of volume elements in two or three dimensions may be prohibitive because of time constraints, but other methods of imaging lipid of water distributions (i.e., selective excitation, selective saturation, or variations in conventional magnetic resonance imaging pulse sequences) can provide chemical shift information. These techniques require less time, but they lack spectral information. Since fat deposition seen by chemical shift imaging may not be demonstrated by conventional magnetic resonance imaging, certain applications of chemical shift imaging, such as in the determination of fatty liver disease, have greater diagnostic utility than conventional magnetic resonance imaging. Furthermore, edge artifacts caused by chemical shift effects can be eliminated by certain selective methods of data acquisition employed in chemical shift imaging

  9. Effects of the fullerene (C{sub 60}) potential and position of the atom (A) on spectral characteristics of endohedral atoms A and C{sub 60}

    Baltenkov, A S [Arifov Institute of Electronics, 100125 Tashkent (Uzbekistan); Becker, U [Fritz-Haber-Institute der Max-Planck-Gesellschaft, D-14195 Berlin (Germany); Manson, S T [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Msezane, A Z, E-mail: arkbalt@mail.r, E-mail: becker@fhi-berlin.mpg.d, E-mail: manson@phy-astr.gsu.ed, E-mail: amsezane@cau.ed [Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States)

    2010-06-14

    Within the framework of a model representing the potential of a C{sub 60} cage as a spherical electro-neutral layer U(r) formed by smeared carbon atoms, the effect of the details of the potential on spectral characteristics of atoms localized inside the fullerene shell has been studied. Using examples of encapsulated H and He atoms, it is shown that for potential shell thickness not exceeding 1.3-1.5 au, confinement resonance oscillations in the photoionization cross section weakly depend on the shape of the function U(r). With increasing width of the potential well, the confinement resonances in the energy dependence of the photoionization cross section disappear. In addition, it is demonstrated that displacing the doped atom from the centre of the cavity also diminishes the amplitude of the confinement resonance.

  10. Market shifting

    Forst, Michael

    2013-11-01

    After years of oversupply and artificially low module pricing, market analysts believe that the solar industry will begin to stabilize by 2017. While the market activities are shifting from Europe to the Asia Pacific region and the United States, the solar shakeout continues to be in full swing including solar cell and module manufacturing. (orig.)

  11. Tough Shift

    Brewer, Robert S.; Verdezoto, Nervo; Holst, Thomas

    2015-01-01

    people to change their behavior at home. Leveraging prior research on encouraging reductions in residential energy use through game play, we introduce ShareBuddy: a casual mobile game intended to encourage players not only to reduce, but also to shift their electricity use. We conducted two field studies...... real-world resource use into a game....

  12. Mapping sound intensities by seating position in a university concert band: A risk of hearing loss, temporary threshold shifts, and comparisons with standards of OSHA and NIOSH

    Holland, Nicholas Vedder, III

    Exposure to loud sounds is one of the leading causes of hearing loss in the United States. The purpose of the current research was to measure the sound pressure levels generated within a university concert band and determine if those levels exceeded permissible sound limits for exposure according to criteria set by the Occupational Safety and Health Administration (OSHA) and the National Institute of Occupational Safety and Health (NIOSH). Time-weighted averages (TWA) were obtained via a dosimeter during six rehearsals for nine members of the ensemble (plus the conductor), who were seated in frontal proximity to "instruments of power" (trumpets, trombones, and percussion; (Backus, 1977). Subjects received audiometer tests prior to and after each rehearsal to determine any temporary threshold shifts (TTS). Single sample t tests were calculated to compare TWA means and the maximum sound intensity exposures set by OSHA and NIOSH. Correlations were calculated between TWAs and TTSs, as well as TTSs and the number of semesters subjects reported being seated in proximity to instruments of power. The TWA-OSHA mean of 90.2 dBA was not significantly greater than the specified OSHA maximum standard of 90.0 dBA (p > .05). The TWA-NIOSH mean of 93.1 dBA was, however, significantly greater than the NIOSH specified maximum standard of 85.0 dBA (p OSHA, r = .20 for NIOSH); the correlation between TTSs and semesters of proximity to instruments of power was also considered weak (r = .13). TWAs cumulatively exceeded both association's sound exposure limits at 11 specified locations (nine subjects and both ears of the conductor) throughout the concert band's rehearsals. In addition, hearing acuity, as determined by TTSs, was substantially affected negatively by the intensities produced in the concert band. The researcher concluded that conductors, as well as their performers, must be aware of possible damaging sound intensities in rehearsals or performances.

  13. Determining the Pressure Shift of Helium I Lines Using White Dwarf Stars

    Camarota, Lawrence

    This dissertation explores the non-Doppler shifting of Helium lines in the high pressure conditions of a white dwarf photosphere. In particular, this dissertation seeks to mathematically quantify the shift in a way that is simple to reproduce and account for in future studies without requiring prior knowledge of the star's bulk properties (mass, radius, temperature, etc.). Two main methods will be used in this analysis. First, the spectral line will be quantified with a continuous wavelet transformation, and the components will be used in a chi2 minimizing linear regression to predict the shift. Second, the position of the lines will be calculated using a best-fit Levy-alpha line function. These techniques stand in contrast to traditional methods of quantifying the center of often broad spectral lines, which usually assume symmetry on the parts of the lines.

  14. Mars analog minerals' spectral reflectance characteristics under Martian surface conditions

    Poitras, J. T.; Cloutis, E. A.; Salvatore, M. R.; Mertzman, S. A.; Applin, D. M.; Mann, P.

    2018-05-01

    We investigated the spectral reflectance properties of minerals under a simulated Martian environment. Twenty-eight different hydrated or hydroxylated phases of carbonates, sulfates, and silica minerals were selected based on past detection on Mars through spectral remote sensing data. Samples were ground and dry sieved to <45 μm grain size and characterized by XRD before and after 133 days inside a simulated Martian surface environment (pressure 5 Torr and CO2 fed). Reflectance spectra from 0.35 to 4 μm were taken periodically through a sapphire (0.35-2.5 μm) and zinc selenide (2.5-4 μm) window over a 133-day period. Mineral stability on the Martian surface was assessed through changes in spectral characteristics. Results indicate that the hydrated carbonates studied would be stable on the surface of Mars, only losing adsorbed H2O while maintaining their diagnostic spectral features. Sulfates were less stable, often with shifts in the band position of the SO, Fe, and OH absorption features. Silicas displayed spectral shifts related to SiOH and hydration state of the mineral surface, while diagnostic bands for quartz were stable. Previous detection of carbonate minerals based on 2.3-2.5 μm and 3.4-3.9 μm features appears to be consistent with our results. Sulfate mineral detection is more questionable since there can be shifts in band position related to SO4. The loss of the 0.43 μm Fe3+ band in many of the sulfates indicate that there are fewer potential candidates for Fe3+ sulfates to permanently exist on the Martian surface based on this band. The gypsum sample changed phase to basanite during desiccation as demonstrated by both reflectance and XRD. Silica on Mars has been detected using band depth ratio at 1.91 and 1.96 μm and band minimum position of the 1.4 μm feature, and the properties are also used to determine their age. This technique continues to be useful for positive silica identifications, however, silica age appears to be less consistent

  15. Core shift effect in blazars

    Agarwal, A.; Mohan, P.; Gupta, Alok C.; Mangalam, A.; Volvach, A. E.; Aller, M. F.; Aller, H. D.; Gu, M. F.; Lähteenmäki, A.; Tornikoski, M.; Volvach, L. N.

    2017-07-01

    We studied the pc-scale core shift effect using radio light curves for three blazars, S5 0716+714, 3C 279 and BL Lacertae, which were monitored at five frequencies (ν) between 4.8 and 36.8 GHz using the University of Michigan Radio Astronomical Observatory (UMRAO), the Crimean Astrophysical Observatory (CrAO) and Metsähovi Radio Observatory for over 40 yr. Flares were Gaussian fitted to derive time delays between observed frequencies for each flare (Δt), peak amplitude (A) and their half width. Using A ∝ να, we infer α in the range of -16.67-2.41 and using Δ t ∝ ν ^{1/k_r}, we infer kr ∼ 1, employed in the context of equipartition between magnetic and kinetic energy density for parameter estimation. From the estimated core position offset (Ωrν) and the core radius (rcore), we infer that opacity model may not be valid in all cases. The mean magnetic field strengths at 1 pc (B1) and at the core (Bcore) are in agreement with previous estimates. We apply the magnetically arrested disc model to estimate black hole spins in the range of 0.15-0.9 for these blazars, indicating that the model is consistent with expected accretion mode in such sources. The power-law-shaped power spectral density has slopes -1.3 to -2.3 and is interpreted in terms of multiple shocks or magnetic instabilities.

  16. Fluid Shifts

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; hide

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  17. A rotated transmission grating spectrometer for detecting spectral separation of doublet Na

    Santosa, Ignatius Edi [Department of Physics Education, Sanata Dharma University, Paingan Maguwohardjo Depok Sleman, Yogyakarta 55281, Indonesia edi@usd.ac.id (Indonesia)

    2015-04-16

    Transmission gratings are usually used in a spectrometer for measuring the wavelength of light. In the common design, the position of the grating is perpendicular to the incident light. In order to increase the angular dispersion, in contrary to the common design, in this experiment the transmission grating was rotated. Due to the non-zero incident angle, the diffracted light was shifted. This rotated transmission grating spectrometer has been used to determine the separation of doublet Na. In this experiment, the diffraction angle was measured at various incident angles. The spectral separation of doublet Na was identified from the difference in the diffraction angle of two spectral lines. This spectral separation depends on the incident angle, the grating constant and the order of diffraction. As the effect of increasing the incident angle, a significant increase of the spectral separation can be achieved up to three fold.

  18. A rotated transmission grating spectrometer for detecting spectral separation of doublet Na

    Santosa, Ignatius Edi

    2015-01-01

    Transmission gratings are usually used in a spectrometer for measuring the wavelength of light. In the common design, the position of the grating is perpendicular to the incident light. In order to increase the angular dispersion, in contrary to the common design, in this experiment the transmission grating was rotated. Due to the non-zero incident angle, the diffracted light was shifted. This rotated transmission grating spectrometer has been used to determine the separation of doublet Na. In this experiment, the diffraction angle was measured at various incident angles. The spectral separation of doublet Na was identified from the difference in the diffraction angle of two spectral lines. This spectral separation depends on the incident angle, the grating constant and the order of diffraction. As the effect of increasing the incident angle, a significant increase of the spectral separation can be achieved up to three fold

  19. Spectral changes in stochastic anisotropic electromagnetic beams propagating through turbulent ocean

    Tang, Miaomiao; Zhao, Daomu

    2014-02-01

    Based on the extended Huygens-Fresnel principle and the unified theory of coherence and polarization of light, the spectral changes of stochastic anisotropic electromagnetic beams propagating through oceanic turbulence are revealed. As an example, some numerical calculations are illustrated for an anisotropic electromagnetic Gaussian Schell-model beam propagating in a homogeneous and isotropic turbulent ocean. It is shown that, under the influence of oceanic turbulence, the on-axis spectrum is always blue-shifted along with the propagation distance, however, for the off-axis positions, red-blue spectral switch can be found.

  20. mGluR5 positive allosteric modulation and its effects on MK-801 induced set-shifting impairments in a rat operant delayed matching/non-matching-to-sample task

    LaCrosse, Amber L.; Burrows, Brian T.; Angulo, Rachel M.; Conrad, Phoebe R.; Himes, Sarah M.; Mathews, Nordia; Wegner, Scott A.; Taylor, Sara B.; Olive, M. Foster

    2014-01-01

    Rationale Positive allosteric modulators (PAMs) of type 5 metabotropic glutamate receptors (mGluR5) exert pro-cognitive effects in animal models of various neuropsychiatric diseases. However, few studies to date have examined ability of mGluR5 PAMs to reverse cognitive deficits in operant delayed matching/non-matching-to-sample (DMS/DNMS) tasks. Objectives To determine the ability of the mGluR5 PAM 3-cyano-N-1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) to reverse set-shifting deficits induced by the NMDA receptor antagonist MK-801. Methods Male Sprague-Dawley rats were initially trained to lever press for sucrose reinforcement under either DMS or DNMS conditions. Following successful acquisition of the task, reinforcement conditions were reversed (DNMS→DMS or DMS→DNMS). In Experiment 1, rats were treated daily prior to each session with either vehicle/vehicle, vehicle/MK-801 (0.06 mg/kg) simultaneously, CDPPB (20 mg/kg)/MK-801 simultaneously, or CDPPB 30 min prior to MK-801. In Experiment 2, rats were treated with either vehicle/vehicle, vehicle/MK-801, or CDPPB 30 min prior to MK-801 only prior to sessions that followed task reversal. Results In Experiment 1, no group differences in initial task acquisition were observed. Rats treated with vehicle+MK−801 showed significant set-shifting impairments following task reversal, which were partially attenuated by simultaneous administration of CDPPB/MK-801, and completely precluded by administration of CDPPB 30 min prior to MK-801. In Experiment 2, MK-801 did not impair reversal learning and no other group differences were observed. Conclusions MK-801 induced deficits in operant set-shifting ability were prevented by pretreatment with CDPPB. MK-801 did not produce deficits in initial task learning or when treatment was initiated following task reversal. PMID:24973895

  1. Shifting Sugars and Shifting Paradigms

    Siegal, Mark L.

    2015-01-01

    No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face. PMID:25688600

  2. Shifting sugars and shifting paradigms.

    Mark L Siegal

    2015-02-01

    Full Text Available No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face.

  3. Engineering of a calcium-ion binding site into the RC-LH1-PufX complex of Rhodobacter sphaeroides to enable ion-dependent spectral red-shifting.

    Swainsbury, David J K; Martin, Elizabeth C; Vasilev, Cvetelin; Parkes-Loach, Pamela S; Loach, Paul A; Neil Hunter, C

    2017-11-01

    The reaction centre-light harvesting 1 (RC-LH1) complex of Thermochromatium (Tch.) tepidum has a unique calcium-ion binding site that enhances thermal stability and red-shifts the absorption of LH1 from 880nm to 915nm in the presence of calcium-ions. The LH1 antenna of mesophilic species of phototrophic bacteria such as Rhodobacter (Rba.) sphaeroides does not possess such properties. We have engineered calcium-ion binding into the LH1 antenna of Rba. sphaeroides by progressively modifying the native LH1 polypeptides with sequences from Tch. tepidum. We show that acquisition of the C-terminal domains from LH1 α and β of Tch. tepidum is sufficient to activate calcium-ion binding and the extent of red-shifting increases with the proportion of Tch. tepidum sequence incorporated. However, full exchange of the LH1 polypeptides with those of Tch. tepidum results in misassembled core complexes. Isolated α and β polypeptides from our most successful mutant were reconstituted in vitro with BChl a to form an LH1-type complex, which was stabilised 3-fold by calcium-ions. Additionally, carotenoid specificity was changed from spheroidene found in Rba. sphaeroides to spirilloxanthin found in Tch. tepidum, with the latter enhancing in vitro formation of LH1. These data show that the C-terminal LH1 α/β domains of Tch. tepidum behave autonomously, and are able to transmit calcium-ion induced conformational changes to BChls bound to the rest of a foreign antenna complex. Thus, elements of foreign antenna complexes, such as calcium-ion binding and blue/red switching of absorption, can be ported into Rhodobacter sphaeroides using careful design processes. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  4. Two-stage unified stretched-exponential model for time-dependence of threshold voltage shift under positive-bias-stresses in amorphous indium-gallium-zinc oxide thin-film transistors

    Jeong, Chan-Yong; Kim, Hee-Joong; Hong, Sae-Young; Song, Sang-Hun; Kwon, Hyuck-In

    2017-08-01

    In this study, we show that the two-stage unified stretched-exponential model can more exactly describe the time-dependence of threshold voltage shift (ΔV TH) under long-term positive-bias-stresses compared to the traditional stretched-exponential model in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). ΔV TH is mainly dominated by electron trapping at short stress times, and the contribution of trap state generation becomes significant with an increase in the stress time. The two-stage unified stretched-exponential model can provide useful information not only for evaluating the long-term electrical stability and lifetime of the a-IGZO TFT but also for understanding the stress-induced degradation mechanism in a-IGZO TFTs.

  5. Spectral evolution of GRBs with negative spectral lag using Fermi GBM observations

    Chakrabarti, Arundhati; Chaudhury, Kishor; Sarkar, Samir K.; Bhadra, Arunava

    2018-06-01

    The positive spectral lag of Gamma Ray Bursts (GRBs) is often explained in terms of hard-to-soft spectral evolution of GRB pulses. While positive lags of GRBs is very common, there are few GRB pulses that exhibits negative spectral lags. In the present work we examine whether negative lags of GRBs also can be interpreted in terms of spectral evolution of GRB pulses or not. Using Fermi-GBM data, we identify two GRBs, GRB 090426C and GRB 150213A, with clean pulses that exhibit negative spectral lag. An indication of soft to hard transition has been noticed for the negative spectral lag events from the spectral evolution study. The implication of the present findings on the models of GRB spectral lags are discussed.

  6. PSYCHE Pure Shift NMR Spectroscopy.

    Foroozandeh, Mohammadali; Morris, Gareth; Nilsson, Mathias

    2018-03-13

    Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. [Spectral features analysis of Pinus massoniana with pest of Dendrolimus punctatus Walker and levels detection].

    Xu, Zhang-Hua; Liu, Jian; Yu, Kun-Yong; Gong, Cong-Hong; Xie, Wan-Jun; Tang, Meng-Ya; Lai, Ri-Wen; Li, Zeng-Lu

    2013-02-01

    Taking 51 field measured hyperspectral data with different pest levels in Yanping, Fujian Province as objects, the spectral reflectance and first derivative features of 4 levels of healthy, mild, moderate and severe insect pest were analyzed. On the basis of 7 detecting parameters construction, the pest level detecting models were built. The results showed that (1) the spectral reflectance of Pinus massoniana with pests were significantly lower than that of healthy state, and the higher the pest level, the lower the reflectance; (2) with the increase in pest level, the spectral reflectance curves' "green peak" and "red valley" of Pinus massoniana gradually disappeared, and the red edge was leveleds (3) the pest led to spectral "green peak" red shift, red edge position blue shift, but the changes in "red valley" and near-infrared position were complicated; (4) CARI, RES, REA and REDVI were highly relevant to pest levels, and the correlations between REP, RERVI, RENDVI and pest level were weak; (5) the multiple linear regression model with the variables of the 7 detection parameters could effectively detect the pest levels of Dendrolimus punctatus Walker, with both the estimation rate and accuracy above 0.85.

  8. Spectral Decomposition Algorithm (SDA)

    National Aeronautics and Space Administration — Spectral Decomposition Algorithm (SDA) is an unsupervised feature extraction technique similar to PCA that was developed to better distinguish spectral features in...

  9. Selective lesion of septal cholinergic neurons in rats impairs acquisition of a delayed matching to position T-maze task by delaying the shift from a response to a place strategy.

    Fitz, Nicholas F; Gibbs, Robert B; Johnson, David A

    2008-12-16

    This study tested the hypothesis that septal cholinergic lesions impair acquisition of a delayed matching to position (DMP) T-maze task in male rats by affecting learning strategy. Rats received either the selective cholinergic immunotoxin, 192 IgG-saporin (SAP) or artificial cerebrospinal fluid directly into the medial septum. Two weeks later, animals were trained to acquire the DMP task. SAP-treated rats took significantly longer to acquire the task than corresponding controls. Both SAP-treated and control rats adopted a persistent turn and utilized a response strategy during early periods of training. By the time rats reached criterion the persistent turn was no longer evident, and all rats had shifted to an allocentric strategy, i.e., were relying on extramaze cues to a significant degree. During the acquisition period, SAP-treated rats spent significantly more days showing a persistent turn and using a response strategy than corresponding controls. The added time spent using a response strategy accounted entirely for the added days required to reach criterion among the SAP-treated rats. This suggests that the principal mechanism by which septal cholinergic lesions impair DMP acquisition in male rats is by increasing the predisposition to use a response vs. a place strategy, thereby affecting the ability to switch from one strategy to another.

  10. A spectral route to determining chirality

    Pedersen, Jesper Goor; Mortensen, Asger

    2009-01-01

    We show how one-dimensional structured media can be used to measure chirality, via the spectral shift of the photonic band gap edges. Analytically, we show that a chiral contrast can, in some cases, be mapped unto an index contrast, thereby greatly simplifying the analysis of such structures. Using...... this mapping, we derive a first-order shift of the band gap edges with chirality. Potentially, this effect could be used for measuring enantiomeric excess....

  11. Search for Higgs shifts in white dwarfs

    Onofrio, Roberto [Dipartimento di Fisica e Astronomia " Galileo Galilei," Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Wegner, Gary A., E-mail: onofrior@gmail.com, E-mail: gary.a.wegner@dartmouth.edu [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States)

    2014-08-20

    We report on a search for differential shifts between electronic and vibronic transitions in carbon-rich white dwarfs BPM 27606 and Procyon B. The absence of differential shifts within the spectral resolution and taking into account systematic effects such as space motion and pressure shifts allows us to set the first upper bound of astrophysical origin on the coupling between the Higgs field and the Kreschmann curvature invariant. Our analysis provides the basis for a more general methodology to derive bounds to the coupling of long-range scalar fields to curvature invariants in an astrophysical setting complementary to the ones available from high-energy physics or table-top experiments.

  12. Visual attention shifting in autism spectrum disorders.

    Richard, Annette E; Lajiness-O'Neill, Renee

    2015-01-01

    Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be

  13. Intensity Conserving Spectral Fitting

    Klimchuk, J. A.; Patsourakos, S.; Tripathi, D.

    2015-01-01

    The detailed shapes of spectral line profiles provide valuable information about the emitting plasma, especially when the plasma contains an unresolved mixture of velocities, temperatures, and densities. As a result of finite spectral resolution, the intensity measured by a spectrometer is the average intensity across a wavelength bin of non-zero size. It is assigned to the wavelength position at the center of the bin. However, the actual intensity at that discrete position will be different if the profile is curved, as it invariably is. Standard fitting routines (spline, Gaussian, etc.) do not account for this difference, and this can result in significant errors when making sensitive measurements. Detection of asymmetries in solar coronal emission lines is one example. Removal of line blends is another. We have developed an iterative procedure that corrects for this effect. It can be used with any fitting function, but we employ a cubic spline in a new analysis routine called Intensity Conserving Spline Interpolation (ICSI). As the name implies, it conserves the observed intensity within each wavelength bin, which ordinary fits do not. Given the rapid convergence, speed of computation, and ease of use, we suggest that ICSI be made a standard component of the processing pipeline for spectroscopic data.

  14. SPECTRAL SMILE CORRECTION IN CRISM HYPERSPECTRAL IMAGES

    Ceamanos, X.; Doute, S.

    2009-12-01

    The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is affected by a common artifact in "push-broom" sensors, the so-called "spectral smile". As a consequence, both central wavelength and spectral width of the spectral response vary along the across-track dimension, thus giving rise to a shifting and smoothing of spectra (see Fig. 1 (left)). In fact, both effects are greater for spectra on the edges, while they are minimum for data acquired by central detectors, the so-called "sweet spot". The prior artifacts become particularly critical for Martian observations which contain steep spectra such as CO2 ice-rich polar images. Fig. 1 (right) shows the horizontal brightness gradient which appears in every band corresponding to a steep portion of spectra. The correction of CRISM spectral smile is addressed using a two-step method which aims at modifying data sensibly in order to mimic the optimal CRISM response. First, all spectra, which are previously interpolated by cubic splines, are resampled to the "sweet spot" wavelengths in order to overcome the spectra shift. Secondly, the non-uniform spectral width is overcome by mimicking an increase of spectral resolution thanks to a spectral sharpening. In order to minimize noise, only bands particularly suffering from smile are selected. First, bands corresponding to the outliers of the Minimum Noise Transformation (MNF) eigenvector, which corresponds to the MNF band related to smile (MNF-smile), are selected. Then, a spectral neighborhood Θi, which takes into account the local spectral convexity or concavity, is defined for every selected band in order to maximize spectral shape preservation. The proposed sharpening technique takes into account both the instrument parameters and the observed spectra. First, every reflectance value belonging to a Θi is reevaluated by a sharpening which depends on a ratio of the spectral width of the current detector and the "sweet spot" one. Then, the optimal degree of

  15. Shift of the spectrum in the non-inertial reference frame

    Kudykina, T. A.; Pervak, A. I.

    2012-01-01

    We propose a new natural explanation of the spectral redshift (blue shift) arguing that the rotatory non-inertial reference frame of cosmological objects is the main reason of the shift of the frequency of emitting light. (Author)

  16. Fourier coefficients of Eisenstein series formed with modular symbols and their spectral decomposition

    Bruggeman, R.W.; Diamantis, N.

    2016-01-01

    The Fourier coefficient of a second order Eisenstein series is described as a shifted convolution sum. This description is used to obtain the spectral decomposition of and estimates for the shifted convolution sum.

  17. Spectral shift controlled reactors, denatured U-233/thorium cycle

    1978-05-01

    This paper presents technical and economic data on the SSCR which may be of use in the International Fuel Cycle Evaluation Program to intercompare alternative nuclear systems. Included in this paper are data on the denatured U-233/thorium cycle. This cycle shows a proliferation advantage over more classical thorium fuel cycle (e.g., highly-enriched U-235/thorium or plutonium/thorium) due to the elimination of chemically-separable, concentrated fissile material from unirradiated nuclear fuel. The U-233 is denatured by mixing with depleted uranium to a concentration no greater than 12 w/o. An exogenous source of U-233 is assumed in this paper, since U-233 does not occur in nature and only a limited supply has been produced to date for research and development work

  18. SPECTRAL SETS AND TILES IN CARTESIAN PRODUCTS OVER ...

    41

    Spectral set conjecture: A Borel set Ω ⊂ Rd of positive and finite. Lebesgue measure is a spectral set if and only if it ... Ω ⊂ G of positive and finite Haar measure is a spectral set if and only if it is a translational tile. ... Key words and phrases. p-adic number field, Cartesian product, tile, spectral set. This work was supported by ...

  19. Audiovisual Cues and Perceptual Learning of Spectrally Distorted Speech

    Pilling, Michael; Thomas, Sharon

    2011-01-01

    Two experiments investigate the effectiveness of audiovisual (AV) speech cues (cues derived from both seeing and hearing a talker speak) in facilitating perceptual learning of spectrally distorted speech. Speech was distorted through an eight channel noise-vocoder which shifted the spectral envelope of the speech signal to simulate the properties…

  20. Spectral gamuts and spectral gamut mapping

    Rosen, Mitchell R.; Derhak, Maxim W.

    2006-01-01

    All imaging devices have two gamuts: the stimulus gamut and the response gamut. The response gamut of a print engine is typically described in CIE colorimetry units, a system derived to quantify human color response. More fundamental than colorimetric gamuts are spectral gamuts, based on radiance, reflectance or transmittance units. Spectral gamuts depend on the physics of light or on how materials interact with light and do not involve the human's photoreceptor integration or brain processing. Methods for visualizing a spectral gamut raise challenges as do considerations of how to utilize such a data-set for producing superior color reproductions. Recent work has described a transformation of spectra reduced to 6-dimensions called LabPQR. LabPQR was designed as a hybrid space with three explicit colorimetric axes and three additional spectral reconstruction axes. In this paper spectral gamuts are discussed making use of LabPQR. Also, spectral gamut mapping is considered in light of the colorimetric-spectral duality of the LabPQR space.

  1. Spectral image reconstruction using an edge preserving spatio-spectral Wiener estimation.

    Urban, Philipp; Rosen, Mitchell R; Berns, Roy S

    2009-08-01

    Reconstruction of spectral images from camera responses is investigated using an edge preserving spatio-spectral Wiener estimation. A Wiener denoising filter and a spectral reconstruction Wiener filter are combined into a single spatio-spectral filter using local propagation of the noise covariance matrix. To preserve edges the local mean and covariance matrix of camera responses is estimated by bilateral weighting of neighboring pixels. We derive the edge-preserving spatio-spectral Wiener estimation by means of Bayesian inference and show that it fades into the standard Wiener reflectance estimation shifted by a constant reflectance in case of vanishing noise. Simulation experiments conducted on a six-channel camera system and on multispectral test images show the performance of the filter, especially for edge regions. A test implementation of the method is provided as a MATLAB script at the first author's website.

  2. Micropatch Antenna Phase Shifting

    Thursby, Michael

    2000-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element with the goal of being able to remove the phase shifting devices from the antenna and replace...

  3. Micropatch Antenna Phase Shifting

    Thursby, Michael

    1999-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element wit the goal of being able to remove the phase shifting devices from the antenna and replace...

  4. OpenShift Workshop

    CERN. Geneva; Rodriguez Peon, Alberto

    2017-01-01

    Workshop to introduce developers to the OpenShift platform available at CERN. Several use cases will be shown, including deploying an existing application into OpenShift. We expect attendees to realize about OpenShift features and general architecture of the service.

  5. Spectral properties of the temporal evolution of brain network structure.

    Wang, Rong; Zhang, Zhen-Zhen; Ma, Jun; Yang, Yong; Lin, Pan; Wu, Ying

    2015-12-01

    The temporal evolution properties of the brain network are crucial for complex brain processes. In this paper, we investigate the differences in the dynamic brain network during resting and visual stimulation states in a task-positive subnetwork, task-negative subnetwork, and whole-brain network. The dynamic brain network is first constructed from human functional magnetic resonance imaging data based on the sliding window method, and then the eigenvalues corresponding to the network are calculated. We use eigenvalue analysis to analyze the global properties of eigenvalues and the random matrix theory (RMT) method to measure the local properties. For global properties, the shifting of the eigenvalue distribution and the decrease in the largest eigenvalue are linked to visual stimulation in all networks. For local properties, the short-range correlation in eigenvalues as measured by the nearest neighbor spacing distribution is not always sensitive to visual stimulation. However, the long-range correlation in eigenvalues as evaluated by spectral rigidity and number variance not only predicts the universal behavior of the dynamic brain network but also suggests non-consistent changes in different networks. These results demonstrate that the dynamic brain network is more random for the task-positive subnetwork and whole-brain network under visual stimulation but is more regular for the task-negative subnetwork. Our findings provide deeper insight into the importance of spectral properties in the functional brain network, especially the incomparable role of RMT in revealing the intrinsic properties of complex systems.

  6. The affective shift model of work engagement.

    Bledow, Ronald; Schmitt, Antje; Frese, Michael; Kühnel, Jana

    2011-11-01

    On the basis of self-regulation theories, the authors develop an affective shift model of work engagement according to which work engagement emerges from the dynamic interplay of positive and negative affect. The affective shift model posits that negative affect is positively related to work engagement if negative affect is followed by positive affect. The authors applied experience sampling methodology to test the model. Data on affective events, mood, and work engagement was collected twice a day over 9 working days among 55 software developers. In support of the affective shift model, negative mood and negative events experienced in the morning of a working day were positively related to work engagement in the afternoon if positive mood in the time interval between morning and afternoon was high. Individual differences in positive affectivity moderated within-person relationships. The authors discuss how work engagement can be fostered through affect regulation. (c) 2011 APA, all rights reserved.

  7. BODIPY associates in organic matrices: Spectral properties, photostability and evaluation as OLED emitters

    Merkushev, D.A.; Usoltsev, S.D. [Ivanovo State University of Chemistry and Technology, Sheremetevskiy Avenue 7, 153000 Ivanovo (Russian Federation); Marfin, Yu.S., E-mail: marfin@isuct.ru [Ivanovo State University of Chemistry and Technology, Sheremetevskiy Avenue 7, 153000 Ivanovo (Russian Federation); Pushkarev, A.P., E-mail: pushkarev@iomc.ras.ru [G.A. Razuvaev Institute of Organometallic Chemistry RAS, Tropinina 49, 603950 Nizhny Novgorod (Russian Federation); Volyniuk, D.; Grazulevicius, J.V. [Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu pl. 19, LT-50254 Kaunas (Lithuania); Rumyantsev, E.V. [Ivanovo State University of Chemistry and Technology, Sheremetevskiy Avenue 7, 153000 Ivanovo (Russian Federation)

    2017-02-01

    In the present study four BODIPY (boron dipyrromethene: 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes with π-extended substituents in C-8 position were investigated in solvents and polymer mediums. High aggregation degree was observed for the dyes in the solid state. Association and twisted intramolecular charge transfer processes were found to affect the spectral properties of the compounds causing bathochromic shifts in absorption and fluorescence spectra. The extension of substituent π-conjugation gains molecular association evoked presumably by π-π interaction between the substituents of the adjacent molecules. Photostability of the complexes in different forms was analyzed and the distorted form stabilized by polymer matrix was found to be the most stable. The substituent nature did not affect strongly the photostability of dyes. Displacement of monomer-associate equilibrium in hybrid materials with polymethylmethacrylate and poly(9-vinylcarbazole) was exploited for tuning spectral characteristics of the materials. Two dyes readily forming aggregates at the lowest concentrations were applied for the fabrication of organic light-emitting diodes. The fabricated devices exhibited electroluminescence in the appropriate spectral ranges with moderate efficiency. - Highlights: • Four BODIPY dyes with π-extended substituents in 8-position were investigated in solvents and polymers. • Substituent influence on photophysical properties and photostability of the compounds are discussed. • Aggregation induced spectral changes were observed. • Displacement of monomer-aggregate equilibrium was exploited for tuning electroluminescent characteristics of OLED devices.

  8. Isotopically varying spectral features of silicon-vacancy in diamond

    Dietrich, Andreas; Jahnke, Kay D; Binder, Jan M; Rogers, Lachlan J; Jelezko, Fedor; Teraji, Tokuyuki; Isoya, Junichi

    2014-01-01

    The silicon-vacancy centre (SiV − ) in diamond has exceptional spectral properties for single-emitter quantum information applications. Most of the fluorescence is concentrated in a strong zero phonon line (ZPL), with a weak phonon sideband extending for 100 nm that contains several clear features. We demonstrate that the ZPL position can be used to reliably identify the silicon isotope present in a single SiV − centre. This is of interest for quantum information applications since only the 29 Si isotope has nuclear spin. In addition, we show that the sharp 64 meV phonon peak is due to a local vibrational mode of the silicon atom. The presence of a local mode suggests a plausible origin of the measured isotopic shift of the ZPL. (paper)

  9. SAT in shift manager training

    Lecuyer, F.

    1995-01-01

    EDF has improved the organization of the operation shift teams with the replacement of shift supervisor in shift manager function. The shift manager is not only responsible for tasks associated to plant operation (production), but he is also responsible for safety of these tasks and for management of shift team members. A job analysis of this new job position has been performed in order to design the training programme. It resulted in a 10-month training programme that includes 8 weeks in safety-related topics and 12 weeks in soft-skills related topics. The safety related training courses are mandatory, the other courses are optional courses depending on individual trainee needs. The training also includes the development of management competencies. During the 10 month period, each trainee develops an individual project that is evaluated by NPP manager. As well, as group project is undertaken by the trainees and overseen by a steering committee. The steering committee participates in the evaluation process and provides operational experience feedback to the trainee groups and to the overall programme

  10. Adaptive Spectral Doppler Estimation

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt

    2009-01-01

    . The methods can also provide better quality of the estimated power spectral density (PSD) of the blood signal. Adaptive spectral estimation techniques are known to pro- vide good spectral resolution and contrast even when the ob- servation window is very short. The 2 adaptive techniques are tested......In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence...... and compared with the averaged periodogram (Welch’s method). The blood power spectral capon (BPC) method is based on a standard minimum variance technique adapted to account for both averaging over slow-time and depth. The blood amplitude and phase estimation technique (BAPES) is based on finding a set...

  11. Effects of extended work shifts and shift work on patient safety, productivity, and employee health.

    Keller, Simone M

    2009-12-01

    It is estimated 1.3 million health care errors occur each year and of those errors 48,000 to 98,000 result in the deaths of patients (Barger et al., 2006). Errors occur for a variety of reasons, including the effects of extended work hours and shift work. The need for around-the-clock staff coverage has resulted in creative ways to maintain quality patient care, keep health care errors or adverse events to a minimum, and still meet the needs of the organization. One way organizations have attempted to alleviate staff shortages is to create extended work shifts. Instead of the standard 8-hour shift, workers are now working 10, 12, 16, or more hours to provide continuous patient care. Although literature does support these staffing patterns, it cannot be denied that shifts beyond the traditional 8 hours increase staff fatigue, health care errors, and adverse events and outcomes and decrease alertness and productivity. This article includes a review of current literature on shift work, the definition of shift work, error rates and adverse outcomes related to shift work, health effects on shift workers, shift work effects on older workers, recommended optimal shift length, positive and negative effects of shift work on the shift worker, hazards associated with driving after extended shifts, and implications for occupational health nurses. Copyright 2009, SLACK Incorporated.

  12. Spectral Line Shapes in Plasmas and Gases

    Oks, E.; Dalimier, D.; Stamm, R.; Stehle, CH.; Gonzalez, M.A.

    2011-01-01

    The subject of spectral line shapes (SLS), a.k.a. spectral line broadening, which embraces both shapes and shifts of spectral lines, is of both fundamental and practical importance. On the fundamental side, the study of the spectral line profiles reveals the underlying atomic and molecular interactions. On the practical side, the spectral line profiles are employed as powerful diagnostic tools for various media, such as neutral gases, technological gas discharges, magnetically confined plasmas for fusion, laser- and Z-pinch-produced plasmas (for fusion and other purposes), astrophysical plasmas (most importantly, solar plasmas), and planetary atmospheres. The research area covered by this special issue includes both the SLS dominated by various electric fields (including electron and ion micro fields in strongly ionized plasmas) and the SLS controlled by neutral particles. In the physical slang, the former is called plasma broadening while the latter is called neutral broadening (of course, the results of neutral broadening apply also to the spectral line broadening in neutral gases)

  13. Introduction to spectral theory

    Levitan, B M

    1975-01-01

    This monograph is devoted to the spectral theory of the Sturm- Liouville operator and to the spectral theory of the Dirac system. In addition, some results are given for nth order ordinary differential operators. Those parts of this book which concern nth order operators can serve as simply an introduction to this domain, which at the present time has already had time to become very broad. For the convenience of the reader who is not familar with abstract spectral theory, the authors have inserted a chapter (Chapter 13) in which they discuss this theory, concisely and in the main without proofs, and indicate various connections with the spectral theory of differential operators.

  14. Detection of Earth-rotation Doppler shift from Suomi National Polar-Orbiting Partnership Cross-Track Infrared Sounder.

    Chen, Yong; Han, Yong; Weng, Fuzhong

    2013-09-01

    The Cross-Track Infrared Sounder (CrIS) on the Suomi National Polar-Orbiting Partnership Satellite is a Fourier transform spectrometer and provides a total of 1305 channels for sounding the atmosphere. Quantifying the CrIS spectral accuracy, which is directly related to radiometric accuracy, is crucial for improving its data assimilation in numerical weather prediction. In this study, a cross-correlation method is used for detecting the effect of Earth-rotation Doppler shift (ERDS) on CrIS observations. Based on a theoretical calculation, the ERDS can be as large as about 1.3 parts in 10(6) (ppm) near Earth's equator and at the satellite scan edge for a field of regard (FOR) of 1 or 30. The CrIS observations exhibit a relative Doppler shift as large as 2.6 ppm for a FOR pair of 1 and 30 near the equator. The variation of the ERDS with latitude and scan position detected from CrIS observations is similar to that derived theoretically, which indicates that the spectral stability of the CrIS instrument is very high. To accurately calibrate CrIS spectral accuracy, the ERDS effect should be removed. Since the ERDS is easily predictable, the Doppler shift is correctable in the CrIS spectra.

  15. Digital staining for histopathology multispectral images by the combined application of spectral enhancement and spectral transformation.

    Bautista, Pinky A; Yagi, Yukako

    2011-01-01

    In this paper we introduced a digital staining method for histopathology images captured with an n-band multispectral camera. The method consisted of two major processes: enhancement of the original spectral transmittance and the transformation of the enhanced transmittance to its target spectral configuration. Enhancement is accomplished by shifting the original transmittance with the scaled difference between the original transmittance and the transmittance estimated with m dominant principal component (PC) vectors;the m-PC vectors were determined from the transmittance samples of the background image. Transformation of the enhanced transmittance to the target spectral configuration was done using an nxn transformation matrix, which was derived by applying a least square method to the enhanced and target spectral training data samples of the different tissue components. Experimental results on the digital conversion of a hematoxylin and eosin (H&E) stained multispectral image to its Masson's trichrome stained (MT) equivalent shows the viability of the method.

  16. Choice Shifts in Groups

    Kfir Eliaz; Debraj Ray

    2004-01-01

    The phenomenon of "choice shifts" in group decision-making is fairly ubiquitous in the social psychology literature. Faced with a choice between a ``safe" and ``risky" decision, group members appear to move to one extreme or the other, relative to the choices each member might have made on her own. Both risky and cautious shifts have been identified in different situations. This paper demonstrates that from an individual decision-making perspective, choice shifts may be viewed as a systematic...

  17. Algorithms for spectral calibration of energy-resolving small-pixel detectors

    Scuffham, J; Veale, M C; Wilson, M D; Seller, P

    2013-01-01

    Small pixel Cd(Zn)Te detectors often suffer from inter-pixel variations in gain, resulting in shifts in the individual energy spectra. These gain variations are mainly caused by inclusions and defects within the crystal structure, which affect the charge transport within the material causing a decrease in the signal pulse height. In imaging applications, spectra are commonly integrated over a particular peak of interest. This means that the individual pixels must be accurately calibrated to ensure that the same portion of the spectrum is integrated in every pixel. The development of large-area detectors with fine pixel pitch necessitates automated algorithms for this spectral calibration, due to the very large number of pixels. Algorithms for automatic spectral calibration require accurate determination of characteristic x-ray or photopeak positions on a pixelwise basis. In this study, we compare two peak searching spectral calibration algorithms for a small-pixel CdTe detector in gamma spectroscopic imaging. The first algorithm uses rigid search ranges to identify peaks in each pixel spectrum, based on the average peak positions across all pixels. The second algorithm scales the search ranges on the basis of the position of the highest-energy peak relative to the average across all pixels. In test spectra acquired with Tc-99m, we found that the rigid search algorithm failed to correctly identify the target calibraton peaks in up to 4% of pixels. In contrast, the scaled search algorithm failed in only 0.16% of pixels. Failures in the scaled search algorithm were attributed to the presence of noise events above the main photopeak, and possible non-linearities in the spectral response in a small number of pixels. We conclude that a peak searching algorithm based on scaling known peak spacings is simple to implement and performs well for the spectral calibration of pixellated radiation detectors

  18. Implementing OpenShift

    Miller, Adam

    2013-01-01

    A standard tutorial-based approach to using OpenShift and deploying custom or pre-built web applications to the OpenShift Online cloud.This book is for software developers and DevOps alike who are interested in learning how to use the OpenShift Platform-as-a-Service for developing and deploying applications, how the environment works on the back end, and how to deploy their very own open source Platform-as-a-Service based on the upstream OpenShift Origin project.

  19. Insomnia in shift work.

    Vallières, Annie; Azaiez, Aïda; Moreau, Vincent; LeBlanc, Mélanie; Morin, Charles M

    2014-12-01

    Shift work disorder involves insomnia and/or excessive sleepiness associated with the work schedule. The present study examined the impact of insomnia on the perceived physical and psychological health of adults working on night and rotating shift schedules compared to day workers. A total of 418 adults (51% women, mean age 41.4 years), including 51 night workers, 158 rotating shift workers, and 209 day workers were selected from an epidemiological study. An algorithm was used to classify each participant of the two groups (working night or rotating shifts) according to the presence or absence of insomnia symptoms. Each of these individuals was paired with a day worker according to gender, age, and income. Participants completed several questionnaires measuring sleep, health, and psychological variables. Night and rotating shift workers with insomnia presented a sleep profile similar to that of day workers with insomnia. Sleep time was more strongly related to insomnia than to shift work per se. Participants with insomnia in the three groups complained of anxiety, depression, and fatigue, and reported consuming equal amounts of sleep-aid medication. Insomnia also contributed to chronic pain and otorhinolaryngology problems, especially among rotating shift workers. Work productivity and absenteeism were more strongly related to insomnia. The present study highlights insomnia as an important component of the sleep difficulties experienced by shift workers. Insomnia may exacerbate certain physical and mental health problems of shift workers, and impair their quality of life. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Characterization of the titanium Kβ spectral profile

    Chantler, C T; Smale, L F; Kinnane, M N; Illig, A J; Kimpton, J A; Crosby, D N

    2013-01-01

    Transition metals have Kα and Kβ characteristic radiation possessing complex asymmetric spectral profiles. Instrumental broadening normally encountered in x-ray experiments shifts features of profiles used for calibration, such as peak energy, by many times the quoted accuracies. We measure and characterize the titanium Kβ spectral profile. The peak energy of the titanium Kβ spectral profile is found to be 4931.966 ± 0.022 eV prior to instrumental broadening. This 4.5 ppm result decreases the uncertainty over the past literature by a factor of 2.6 and is 2.4 standard deviations from the previous standard. The spectrum is analysed and the resolution-free lineshape is extracted and listed for use in other experiments. We also incorporate improvement in analysis applied to earlier results for V Kβ. (paper)

  1. Spectral properties of 441 radio pulsars

    Jankowski, F.; van Straten, W.; Keane, E. F.; Bailes, M.; Barr, E. D.; Johnston, S.; Kerr, M.

    2018-02-01

    We present a study of the spectral properties of 441 pulsars observed with the Parkes radio telescope near the centre frequencies of 728, 1382 and 3100 MHz. The observations at 728 and 3100 MHz were conducted simultaneously using the dual-band 10-50 cm receiver. These high-sensitivity, multifrequency observations provide a systematic and uniform sample of pulsar flux densities. We combine our measurements with spectral data from the literature in order to derive the spectral properties of these pulsars. Using techniques from robust regression and information theory, we classify the observed spectra in an objective, robust and unbiased way into five morphological classes: simple or broken power law, power law with either low- or high-frequency cut-off and log-parabolic spectrum. While about 79 per cent of the pulsars that could be classified have simple power-law spectra, we find significant deviations in 73 pulsars, 35 of which have curved spectra, 25 with a spectral break and 10 with a low-frequency turn-over. We identify 11 gigahertz-peaked spectrum (GPS) pulsars, with 3 newly identified in this work and 8 confirmations of known GPS pulsars; 3 others show tentative evidence of GPS, but require further low-frequency measurements to support this classification. The weighted mean spectral index of all pulsars with simple power-law spectra is -1.60 ± 0.03. The observed spectral indices are well described by a shifted log-normal distribution. The strongest correlations of spectral index are with spin-down luminosity, magnetic field at the light-cylinder and spin-down rate. We also investigate the physical origin of the observed spectral features and determine emission altitudes for three pulsars.

  2. On Longitudinal Spectral Coherence

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between ...... observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed....

  3. Hexa pyranoside homologation: use of spectral width narrowing, and the chemical shift homonuclear correlation for characterization of the 4,6-0-benzylidene-2,3-di des oxy-3-C-hydroxymethyl-{alpha}-D-methyl ribopyranoside; Homologacao de hexopiranosideos: utilizacao de reducao da largura espectral e de correlacao homonuclear de deslocamentos quimicos para a caracterizacao do 4,6-O-benzilideno-2,3-didesoxi-3-C-hidroximetil-{alpha}-D- ribopiranosideo de metila (7)

    Souza Filho, J D; Silva, L.G. Fonseca e; Oliveira, A Braga de; Alves, R Jose [Minas Gerais Univ., Belo Horizonte, MG (Brazil); Lukacs, G [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France). Inst. de Chimie des Substances Naturelles

    1992-12-31

    The discovery of ramified sugars as various antibiotics constituents, leads to the development of various preparation technologies. In the framework of hexapiranose analogues synthesis, the alcohol-7 was the intermediary on which functional group interconversion reactions were performed. The carbonyl group reduction with Na B H{sub 4} in MeOH{sup 5} was performed, for obtaining the ethyl alcohol-6 a (99%). Later on, the reaction of stereoselective reduction of the double binding between C-2 and C-3 was conducted in presence of Ni-Ra in Ac O Et, allowing to obtain the two epimer 7 and 7 a alcohols, with 86.9 and 7.5% yield respectively. The 7 {sup 1} H NMR signals were easily assigned by analysing the extended spectrum obtained by narrowing the spectral line. In accordance with predictable multiplicity and H-6{alpha} (Triplet at 3.7 ppm) patterns, the triple doublet H-5, at 4.1 ppm has been assigned. The assignments were confirmed by a chemical shift homonuclear correlation experiment (COSY H-H). H-7, H-7{sup `} and H-4 have been assigned through the H-3. The use of hydroxyl proton as reference (d d, 2.72 ppm) allowed the confirmation of the chemical shift assigned to H-7 and H-7{sup `} 5 refs., 6 figs.

  4. Shifted Independent Component Analysis

    Mørup, Morten; Madsen, Kristoffer Hougaard; Hansen, Lars Kai

    2007-01-01

    Delayed mixing is a problem of theoretical interest and practical importance, e.g., in speech processing, bio-medical signal analysis and financial data modelling. Most previous analyses have been based on models with integer shifts, i.e., shifts by a number of samples, and have often been carried...

  5. Homogeneous bilateral block shifts

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  6. OpenShift cookbook

    Gulati, Shekhar

    2014-01-01

    If you are a web application developer who wants to use the OpenShift platform to host your next big idea but are looking for guidance on how to achieve this, then this book is the first step you need to take. This is a very accessible cookbook where no previous knowledge of OpenShift is needed.

  7. Josephson shift registers

    Przybysz, J.X.

    1989-01-01

    This paper gives a review of Josephson shift register circuits that were designed, fabricated, or tested, with emphasis on work in the 1980s. Operating speed is most important, since it often limits system performance. Older designs used square-wave clocks, but most modern designs use offset sine waves, with either two or three phases. Operating margins and gate bias uniformity are key concerns. The fastest measured Josephson shift register operated at 2.3 GHz, which compares well with a GaAs shift register that consumes 250 times more power. The difficulties of high-speed testing have prevented many Josephson shift registers from being operated at their highest speeds. Computer simulations suggest that 30-GHz operation is possible with current Nb/Al 2 O 3 /Nb technology. Junctions with critical current densities near 10 kA/cm 2 would make 100-GHz shift registers feasible

  8. Towards red-edge positions less sensitive to canopy biophysical parameters for leaf chlorophyll estimation using properties optique spectrales des feuilles (PROSPECT) and scattering by arbitrarily inclined leaves (SAILH) simulated data

    Cho, M.A.; Skidmore, A.K.; Atzberger, C.

    2008-01-01

    Several methods for extracting the chlorophyll sensitive red-edge position (REP) from hyperspectral data are reported in literature. This study is a continuation of a recent paper published as 'A new technique for extracting the red edge position from hyperspectral data: the linear extrapolation

  9. Estimation of spectral kurtosis

    Sutawanir

    2017-03-01

    Rolling bearings are the most important elements in rotating machinery. Bearing frequently fall out of service for various reasons: heavy loads, unsuitable lubrications, ineffective sealing. Bearing faults may cause a decrease in performance. Analysis of bearing vibration signals has attracted attention in the field of monitoring and fault diagnosis. Bearing vibration signals give rich information for early detection of bearing failures. Spectral kurtosis, SK, is a parameter in frequency domain indicating how the impulsiveness of a signal varies with frequency. Faults in rolling bearings give rise to a series of short impulse responses as the rolling elements strike faults, SK potentially useful for determining frequency bands dominated by bearing fault signals. SK can provide a measure of the distance of the analyzed bearings from a healthy one. SK provides additional information given by the power spectral density (psd). This paper aims to explore the estimation of spectral kurtosis using short time Fourier transform known as spectrogram. The estimation of SK is similar to the estimation of psd. The estimation falls in model-free estimation and plug-in estimator. Some numerical studies using simulations are discussed to support the methodology. Spectral kurtosis of some stationary signals are analytically obtained and used in simulation study. Kurtosis of time domain has been a popular tool for detecting non-normality. Spectral kurtosis is an extension of kurtosis in frequency domain. The relationship between time domain and frequency domain analysis is establish through power spectrum-autocovariance Fourier transform. Fourier transform is the main tool for estimation in frequency domain. The power spectral density is estimated through periodogram. In this paper, the short time Fourier transform of the spectral kurtosis is reviewed, a bearing fault (inner ring and outer ring) is simulated. The bearing response, power spectrum, and spectral kurtosis are plotted to

  10. Education and training of the shift technical advisor

    Thomas, E.L.

    1981-01-01

    This paper discusses the background and current approaches for qualifying the required position of Shift Technical Advisor (STA). Industry positions regarding the regulation are given. Problems associated with meeting the requirement are identified, along with a discussion of other alternatives for upgrading the education level of shift management. Inherent in the discussion is the conclusion that voluntary improvements in the training and education of shift management personnel are more effective than mandatory positions or degree requirements

  11. Spectrally accurate contour dynamics

    Van Buskirk, R.D.; Marcus, P.S.

    1994-01-01

    We present an exponentially accurate boundary integral method for calculation the equilibria and dynamics of piece-wise constant distributions of potential vorticity. The method represents contours of potential vorticity as a spectral sum and solves the Biot-Savart equation for the velocity by spectrally evaluating a desingularized contour integral. We use the technique in both an initial-value code and a newton continuation method. Our methods are tested by comparing the numerical solutions with known analytic results, and it is shown that for the same amount of computational work our spectral methods are more accurate than other contour dynamics methods currently in use

  12. Spectral radius of graphs

    Stevanovic, Dragan

    2015-01-01

    Spectral Radius of Graphs provides a thorough overview of important results on the spectral radius of adjacency matrix of graphs that have appeared in the literature in the preceding ten years, most of them with proofs, and including some previously unpublished results of the author. The primer begins with a brief classical review, in order to provide the reader with a foundation for the subsequent chapters. Topics covered include spectral decomposition, the Perron-Frobenius theorem, the Rayleigh quotient, the Weyl inequalities, and the Interlacing theorem. From this introduction, the

  13. Night shift work and modifiable lifestyle factors.

    Pepłońska, Beata; Burdelak, Weronika; Krysicka, Jolanta; Bukowska, Agnieszka; Marcinkiewicz, Andrzej; Sobala, Wojciech; Klimecka-Muszyńska, Dorota; Rybacki, Marcin

    2014-10-01

    Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more) - 434 individuals currently working night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI), number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Recreational inactivity (defined here as less than one hour per week of recreational physical activity) was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22) among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029). This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

  14. Night shift work and modifiable lifestyle factors

    Beata Pepłońska

    2014-10-01

    Full Text Available Objectives: Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. Material and Methods: The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more - 434 individuals currently wor­king night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI, number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Results: Recreational inactivity (defined here as less than one hour per week of recreational physical activity was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22 among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029. Conclusions: This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

  15. Spectral quality requirements for effluent identification

    Czerwinski, R. N.; Seeley, J. A.; Wack, E. C.

    2005-11-01

    We consider the problem of remotely identifying gaseous materials using passive sensing of long-wave infrared (LWIR) spectral features at hyperspectral resolution. Gaseous materials are distinguishable in the LWIR because of their unique spectral fingerprints. A sensor degraded in capability by noise or limited spectral resolution, however, may be unable to positively identify contaminants, especially if they are present in low concentrations or if the spectral library used for comparisons includes materials with similar spectral signatures. This paper will quantify the relative importance of these parameters and express the relationships between them in a functional form which can be used as a rule of thumb in sensor design or in assessing sensor capability for a specific task. This paper describes the simulation of remote sensing datacontaining a gas cloud.In each simulation, the spectra are degraded in spectral resolution and through the addition of noise to simulate spectra collected by sensors of varying design and capability. We form a trade space by systematically varying the number of sensor spectral channels and signal-to-noise ratio over a range of values. For each scenario, we evaluate the capability of the sensor for gas identification by computing the ratio of the F-statistic for the truth gas tothe same statistic computed over the rest of the library.The effect of the scope of the library is investigated as well, by computing statistics on the variability of the identification capability as the library composition is varied randomly.

  16. Spectral unmixing: estimating partial abundances

    Debba, Pravesh

    2009-01-01

    Full Text Available techniques is complicated when considering very similar spectral signatures. Iron-bearing oxide/hydroxide/sulfate minerals have similar spectral signatures. The study focuses on how could estimates of abundances of spectrally similar iron-bearing oxide...

  17. Rectangular spectral collocation

    Driscoll, Tobin A.; Hale, Nicholas

    2015-01-01

    Boundary conditions in spectral collocation methods are typically imposed by removing some rows of the discretized differential operator and replacing them with others that enforce the required conditions at the boundary. A new approach based upon

  18. Vowel Inherent Spectral Change

    Assmann, Peter

    2013-01-01

    It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel Inherent Spectral Change has been observed in speakers’ productions, and has also been found to have a substantial effect on listeners’ perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. This book includes chapters addressing various aspects of vowel inherent spectral change (VISC), including theoretical and experimental studies of the perceptually relevant aspects of VISC, the relationship between ar...

  19. Nurses' shift reports

    Buus, Niels; Hoeck, Bente; Hamilton, Bridget Elizabeth

    2017-01-01

    AIMS AND OBJECTIVES: To identify reporting practices that feature in studies of nurses' shift reports across diverse nursing specialities. The objectives were to perform an exhaustive systematic literature search and to critically review the quality and findings of qualitative field studies...... of nurses' shift reports. BACKGROUND: Nurses' shift reports are routine occurrences in healthcare organisations that are viewed as crucial for patient outcomes, patient safety and continuity of care. Studies of communication between nurses attend primarily to 1:1 communication and analyse the adequacy...... and accuracy of patient information and feature handovers at the bedside. Still, verbal reports between groups of nurses about patients are commonplace. Shift reports are obvious sites for studying the situated accomplishment of professional nursing at the group level. This review is focused exclusively...

  20. Shift Verification and Validation

    Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-07

    This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

  1. Spectrally selective glazings

    NONE

    1998-08-01

    Spectrally selective glazing is window glass that permits some portions of the solar spectrum to enter a building while blocking others. This high-performance glazing admits as much daylight as possible while preventing transmission of as much solar heat as possible. By controlling solar heat gains in summer, preventing loss of interior heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of daylight, spectrally selective glazing significantly reduces building energy consumption and peak demand. Because new spectrally selective glazings can have a virtually clear appearance, they admit more daylight and permit much brighter, more open views to the outside while still providing the solar control of the dark, reflective energy-efficient glass of the past. This Federal Technology Alert provides detailed information and procedures for Federal energy managers to consider spectrally selective glazings. The principle of spectrally selective glazings is explained. Benefits related to energy efficiency and other architectural criteria are delineated. Guidelines are provided for appropriate application of spectrally selective glazing, and step-by-step instructions are given for estimating energy savings. Case studies are also presented to illustrate actual costs and energy savings. Current manufacturers, technology users, and references for further reading are included for users who have questions not fully addressed here.

  2. Molecular Electronic Shift Registers

    Beratan, David N.; Onuchic, Jose N.

    1990-01-01

    Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

  3. Spectral lines of methane measured up to 2.6 THz at sub-MHz accuracy with a CW-THz photomixing spectrometer: Line positions of rotational transitions induced by centrifugal distortion

    Bray, C.; Cuisset, A.; Hindle, F.; Mouret, G.; Bocquet, R.; Boudon, V.

    2017-12-01

    Several Doppler-limited rotational transitions of methane induced by centrifugal distortion have been measured with an unprecedented frequency accuracy using a THz photomixing synthesizer based on a frequency comb. Compared to previous synchrotron based FT-Far-IR measurements of Boudon et al. (Ref. [1]), the accuracy of the line frequency measurements is improved by one order of magnitude; this yields a corresponding increase of two orders of magnitude to the weighting of these transitions in the global fit. The rotational transitions in the ν4 ←ν4 hot band are measured for the first time by the broad spectral coverage of the photomixing CW-THz spectrometer providing access up to R(5) transitions at 2.6 THz. The new global fit including the present lines has been used to update the methane line list of the HITRAN database. Some small, but significant variations of the parameter values are observed and are accompanied by a reduction of the 1-σ uncertainties on the rotational (B0) and centrifugal distortion (D0) constants.

  4. Giant Lamb shift in photonic crystals

    Wang Xuehua; Kivshar, Yuri S.; Gu Benyuan

    2004-01-01

    We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases

  5. Information-efficient spectral imaging sensor

    Sweatt, William C.; Gentry, Stephen M.; Boye, Clinton A.; Grotbeck, Carter L.; Stallard, Brian R.; Descour, Michael R.

    2003-01-01

    A programmable optical filter for use in multispectral and hyperspectral imaging. The filter splits the light collected by an optical telescope into two channels for each of the pixels in a row in a scanned image, one channel to handle the positive elements of a spectral basis filter and one for the negative elements of the spectral basis filter. Each channel for each pixel disperses its light into n spectral bins, with the light in each bin being attenuated in accordance with the value of the associated positive or negative element of the spectral basis vector. The spectral basis vector is constructed so that its positive elements emphasize the presence of a target and its negative elements emphasize the presence of the constituents of the background of the imaged scene. The attenuated light in the channels is re-imaged onto separate detectors for each pixel and then the signals from the detectors are combined to give an indication of the presence or not of the target in each pixel of the scanned scene. This system provides for a very efficient optical determination of the presence of the target, as opposed to the very data intensive data manipulations that are required in conventional hyperspectral imaging systems.

  6. Stokes shift spectroscopy for breast cancer diagnosis

    Jeyasingh, Ebenezar; Prakashrao, Aruna; Singaravelu, Ganesan

    2010-02-01

    The objective of this study is to assess the diagnostic potential of stokes shift (SS) spectroscopy (SSS) for normal and different pathological breast tissues such as fibroadenoma and infiltrating ductal carcinoma. The SS spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological breast tissues were observed. The SS spectra of normal and different pathological breast tissues shows the distinct peaks around 300, 350, 450, 500 and 600 nm may be attributed to tryptophan, collagen, NADH, flavin and porphyrin respectively. Using SSS technique one can obtain all the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological breast tissues are verified by different ratio parameters.

  7. Shifted excitation Raman difference spectroscopy for authentication of cheese and cheese analogues

    Sowoidnich, Kay; Kronfeldt, Heinz-Detlef

    2016-04-01

    Food authentication and the detection of adulterated products are recent major issues in the food industry as these topics are of global importance for quality control and food safety. To effectively address this challenge requires fast, reliable and non-destructive analytical techniques. Shifted Excitation Raman Difference Spectroscopy (SERDS) is well suited for identification purposes as it combines the chemically specific information obtained by Raman spectroscopy with the ability for efficient fluorescence rejection. The two slightly shifted excitation wavelengths necessary for SERDS are realized by specially designed microsystem diode lasers. At 671 nm the laser (optical power: 50 mW, spectral shift: 0.7 nm) is based on an external cavity configuration whereas an emission at 783 nm (optical power: 110 mW, spectral shift: 0.5 nm) is achieved by a distributed feedback laser. To investigate the feasibility of SERDS for rapid and nondestructive authentication purposes four types of cheese and three different cheese analogues were selected. Each sample was probed at 8 different positions using integration times of 3-10 seconds and 10 spectra were recorded at each spot. Principal components analysis was applied to the SERDS spectra revealing variations in fat and protein signals as primary distinction criterion between cheese and cheese analogues for both excitation wavelengths. Furthermore, to some extent, minor compositional differences could be identified to discriminate between individual species of cheese and cheese analogues. These findings highlight the potential of SERDS for rapid food authentication potentially paving the way for future applications of portable SERDS systems for non-invasive in situ analysis.

  8. Some threshold spectral problems of Schroedinger operators

    Jia, X.

    2009-01-01

    This Ph.D. thesis deals with some spectral problems of the Schroedinger operators. We first consider the semi-classical limit of the number of bound states of unique two-cluster N-body Schroedinger operator. Then we use Dirichlet-Neumann bracket to get semi-classical limit of Riesz means of the discrete eigenvalues of N-body Schroedinger operator. The effective potential of N-body Schroedinger operator with Coulomb potential is also considered and we find that the effective potential has critical decay at infinity. Thus, the Schroedinger operator with critical potential is studied in this thesis. We study the coupling constant threshold of Schroedinger operator with critical potential and the asymptotic expansion of resolvent of Schroedinger operator with critical potential. We use that expansion to study low-energy asymptotics of derivative of spectral shift function for perturbation with critical decay. After that, we use this result and the known result for high-energy asymptotic expansion of spectral shift function to obtain the Levinson theorem. (author)

  9. Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

    Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

    2012-07-30

    A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

  10. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy

    Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy

    2015-01-01

    Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), 1 H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong 1 H– 1 H homonuclear dipolar couplings and narrow 1 H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) 1 H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about 1 H– 1 H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical

  11. Measuring Velocity and Acceleration Using Doppler Shift of a ...

    to be used to measure its velocity and acceleration. We also apply this method, as an example here, to spectral lines of the blue-shifted jet in micro-quasar SS433 and discuss the intricacies of these measurements. Key words. Doppler effect—measuring velocity and acceleration of the source— jet in SS433. 1. Introduction.

  12. CRISS power spectral density

    Vaeth, W.

    1979-04-01

    The correlation of signal components at different frequencies like higher harmonics cannot be detected by a normal power spectral density measurement, since this technique correlates only components at the same frequency. This paper describes a special method for measuring the correlation of two signal components at different frequencies: the CRISS power spectral density. From this new function in frequency analysis, the correlation of two components can be determined quantitatively either they stem from one signal or from two diverse signals. The principle of the method, suitable for the higher harmonics of a signal as well as for any other frequency combinations is shown for the digital frequency analysis technique. Two examples of CRISS power spectral densities demonstrates the operation of the new method. (orig.) [de

  13. Parametric Explosion Spectral Model

    Ford, S R; Walter, W R

    2012-01-19

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  14. Photovoltaic spectral responsivity measurements

    Emery, K.; Dunlavy, D.; Field, H.; Moriarty, T. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    This paper discusses the various elemental random and nonrandom error sources in typical spectral responsivity measurement systems. The authors focus specifically on the filter and grating monochrometer-based spectral responsivity measurement systems used by the Photovoltaic (PV) performance characterization team at NREL. A variety of subtle measurement errors can occur that arise from a finite photo-current response time, bandwidth of the monochromatic light, waveform of the monochromatic light, and spatial uniformity of the monochromatic and bias lights; the errors depend on the light source, PV technology, and measurement system. The quantum efficiency can be a function of he voltage bias, light bias level, and, for some structures, the spectral content of the bias light or location on the PV device. This paper compares the advantages and problems associated with semiconductor-detector-based calibrations and pyroelectric-detector-based calibrations. Different current-to-voltage conversion and ac photo-current detection strategies employed at NREL are compared and contrasted.

  15. Spectral analysis by correlation

    Fauque, J.M.; Berthier, D.; Max, J.; Bonnet, G.

    1969-01-01

    The spectral density of a signal, which represents its power distribution along the frequency axis, is a function which is of great importance, finding many uses in all fields concerned with the processing of the signal (process identification, vibrational analysis, etc...). Amongst all the possible methods for calculating this function, the correlation method (correlation function calculation + Fourier transformation) is the most promising, mainly because of its simplicity and of the results it yields. The study carried out here will lead to the construction of an apparatus which, coupled with a correlator, will constitute a set of equipment for spectral analysis in real time covering the frequency range 0 to 5 MHz. (author) [fr

  16. Spectral backward radiation profile

    Kwon, Sung Duck; Lee, Keun Hyun; Kim, Bo Ra; Yoon, Suk Soo

    2004-01-01

    Ultrasonic backward radiation profile is frequency-dependent when incident region has deptional gradient of acoustical properties or multi-layers. Until now, we have measured the profiles of principal frequencies of used transducers so that it was not easy to understand the change of the frequency component and spectrum of backward radiation from the profile. We tried to measure the spectral backward radiation profiles using DFP(digital filer package) Lecroy DSO. The very big changes in the shape and pattern of spectral backward radiation profiles leads to the conclusion that this new try could be very effective tool to evaluate frequency dependent surface area.

  17. Spectral Properties and Orientation of Voltage-Sensitive Dyes in Lipid Membranes

    Matson, Maria; Carlsson, Nils; Beke-Somfai, Tamá s; Nordé n, Bengt

    2012-01-01

    Voltage-sensitive dyes are frequently used for probing variations in the electric potential across cell membranes. The dyes respond by changing their spectral properties: measured as shifts of wavelength of absorption or emission maxima

  18. Spectral Ensemble Kalman Filters

    Mandel, Jan; Kasanický, Ivan; Vejmelka, Martin; Fuglík, Viktor; Turčičová, Marie; Eben, Kryštof; Resler, Jaroslav; Juruš, Pavel

    2014-01-01

    Roč. 11, - (2014), EMS2014-446 [EMS Annual Meeting /14./ & European Conference on Applied Climatology (ECAC) /10./. 06.10.2014-10.10.2014, Prague] R&D Projects: GA ČR GA13-34856S Grant - others:NSF DMS-1216481 Institutional support: RVO:67985807 Keywords : data assimilation * spectral filter Subject RIV: DG - Athmosphere Sciences, Meteorology

  19. Natural and artificial spectral edges in exoplanets

    Lingam, Manasvi; Loeb, Abraham

    2017-09-01

    Technological civilizations may rely upon large-scale photovoltaic arrays to harness energy from their host star. Photovoltaic materials, such as silicon, possess distinctive spectral features, including an 'artificial edge' that is characteristically shifted in wavelength shortwards of the 'red edge' of vegetation. Future observations of reflected light from exoplanets would be able to detect both natural and artificial edges photometrically, if a significant fraction of the planet's surface is covered by vegetation or photovoltaic arrays, respectively. The stellar energy thus tapped can be utilized for terraforming activities by transferring heat and light from the day side to the night side on tidally locked exoplanets, thereby producing detectable artefacts.

  20. X-ray spectral decomposition imaging system

    1977-07-27

    Projection measurements are made of the transmitted X-ray beam in low and high energy regions. These are combined in a non-linear processor to produce atomic-number-dependent and density-dependent projection information. This information is used to provide cross-sectional images which are free of spectral-shift artifacts and completely define the specific material properties. The invention described herein was made in the course of work under a grant from the Department of Health, Education, and Welfare.

  1. A Simple Spectral Observer

    Lizeth Torres

    2018-05-01

    Full Text Available The principal aim of a spectral observer is twofold: the reconstruction of a signal of time via state estimation and the decomposition of such a signal into the frequencies that make it up. A spectral observer can be catalogued as an online algorithm for time-frequency analysis because is a method that can compute on the fly the Fourier transform (FT of a signal, without having the entire signal available from the start. In this regard, this paper presents a novel spectral observer with an adjustable constant gain for reconstructing a given signal by means of the recursive identification of the coefficients of a Fourier series. The reconstruction or estimation of a signal in the context of this work means to find the coefficients of a linear combination of sines a cosines that fits a signal such that it can be reproduced. The design procedure of the spectral observer is presented along with the following applications: (1 the reconstruction of a simple periodical signal, (2 the approximation of both a square and a triangular signal, (3 the edge detection in signals by using the Fourier coefficients, (4 the fitting of the historical Bitcoin market data from 1 December 2014 to 8 January 2018 and (5 the estimation of a input force acting upon a Duffing oscillator. To round out this paper, we present a detailed discussion about the results of the applications as well as a comparative analysis of the proposed spectral observer vis-à-vis the Short Time Fourier Transform (STFT, which is a well-known method for time-frequency analysis.

  2. Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort

    Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P. C.; Tse, Gary; Wong, Martin C. S.; Tang, Jin-ling; Wong, Samuel Y. S.; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

    2018-01-01

    Aims This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. Methods A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants’ demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Results Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97–1.41) and 1.27 (95% CI, 0.74–2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01–1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40–11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19–9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13–2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94–1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Conclusion Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies. PMID:29763461

  3. Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort.

    Sun, Miaomiao; Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P C; Tse, Gary; Wong, Martin C S; Tang, Jin-Ling; Wong, Samuel Y S; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

    2018-01-01

    This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants' demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97-1.41) and 1.27 (95% CI, 0.74-2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01-1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40-11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19-9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13-2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94-1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies.

  4. Change from an 8-hour shift to a 12-hour shift, attitudes, sleep, sleepiness and performance.

    Lowden, A; Kecklund, G; Axelsson, J; Akerstedt, T

    1998-01-01

    The present study sought to evaluate the effect of a change from a rotating 3-shift (8-hour) to a 2-shift shift (12 hour) schedule on sleep, sleepiness, performance, perceived health, and well-being. Thirty-two shift workers at a chemical plant (control room operators) responded to a questionnaire a few months before a change was made in their shift schedule and 10 months after the change. Fourteen workers also filled out a diary, carried activity loggers, and carried out reaction-time tests (beginning and end of shift). Fourteen day workers served as a reference group for the questionnaires and 9 were intensively studied during a week with workdays and a free weekend. The questionnaire data showed that the shift change increased satisfaction with workhours, sleep, and time for social activities. Health, perceived accident risk, and reaction-time performance were not negatively affected. Alertness improved and subjective recovery time after night work decreased. The quick changes in the 8-hour schedule greatly increased sleep problems and fatigue. Sleepiness integrated across the entire shift cycle showed that the shift workers were less alert than the day workers, across workdays and days off (although alertness increased with the 12-hour shift). The change from 8-hour to 12-hour shifts was positive in most respects, possibly due to the shorter sequences of the workdays, the longer sequences of consecutive days off, the fewer types of shifts (easier planning), and the elimination of quick changes. The results may differ in groups with a higher work load.

  5. Lateral shifting in one dimensional chiral photonic crystal

    You Yuan; Chen Changyuan

    2012-01-01

    We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

  6. Lateral shifting in one dimensional chiral photonic crystal

    You Yuan, E-mail: yctcyouyuan@163.com [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China); Chen Changyuan [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China)

    2012-07-01

    We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

  7. Nanoengineering of photonic crystal fibers for supercontinuum spectral shaping

    Frosz, Michael Henoch; Sørensen, Thorkild; Bang, Ole

    2006-01-01

    ) on the location of the Stokes and anti-Stokes bands and gain bandwidth. An analysis shows that the Raman effect is responsible for reducing the four-wave mixing gain and a slight reduction in the corresponding frequency shift from the pump, when the frequency shift is much larger than the Raman shift. Using......Supercontinuum generation using picosecond pulses pumped into cobweb photonic crystal fibers is investigated. Dispersion profiles are calculated for several fiber designs and used to analytically investigate the influence of the fiber structural parameters (core size and wall thickness...... numerical simulations we find that four-wave mixing is the dominant physical mechanism for the pumping scheme considered, and that there is a trade-off between the spectral width and the spectral flatness of the supercontinuum. The balance of this trade-off is determined by nanometer-scale design...

  8. Lateral shift in one-dimensional quasiperiodic chiral photonic crystal

    Da, Jian, E-mail: dajian521@sina.com [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Mo, Qi, E-mail: moqiyueyang@163.com [School of Software, Yunnan University, Cuihu Bai Road, Kunming City, Yunnan Province 650091 (China); Cheng, Yaokun [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Liu, Taixiang [Taishan Vocational College of Nursing, Shandong Province 271000 (China)

    2015-02-01

    We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.

  9. Robust balance shift control with posture optimization

    Kavafoglu, Z.; Kavafoglu, Ersan; Egges, J.

    2015-01-01

    In this paper we present a control framework which creates robust and natural balance shifting behaviours during standing. Given high-level features such as the position of the center of mass projection and the foot configurations, a kinematic posture satisfying these features is synthesized using

  10. Hybrid spectral CT reconstruction.

    Darin P Clark

    Full Text Available Current photon counting x-ray detector (PCD technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID. In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM. Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with

  11. Hybrid spectral CT reconstruction

    Clark, Darin P.

    2017-01-01

    Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

  12. Noncommutativity from spectral flow

    Heinzl, Thomas; Ilderton, Anton [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2007-07-27

    We investigate the transition from second- to first-order systems. Quantum mechanically, this transforms configuration space into phase space and hence introduces noncommutativity in the former. This transition may be described in terms of spectral flow. Gaps in the energy or mass spectrum may become large which effectively truncates the available state space. Using both operator and path integral languages we explicitly discuss examples in quantum mechanics (light-front) quantum field theory and string theory.

  13. Speech recognition from spectral dynamics

    Carrier nature of speech; modulation spectrum; spectral dynamics ... the relationships between phonetic values of sounds and their short-term spectral envelopes .... the number of free parameters that need to be estimated from training data.

  14. Understanding Soliton Spectral Tunneling as a Spectral Coupling Effect

    Guo, Hairun; Wang, Shaofei; Zeng, Xianglong

    2013-01-01

    Soliton eigenstate is found corresponding to a dispersive phase profile under which the soliton phase changes induced by the dispersion and nonlinearity are instantaneously counterbalanced. Much like a waveguide coupler relying on a spatial refractive index profile that supports mode coupling...... between channels, here we suggest that the soliton spectral tunneling effect can be understood supported by a spectral phase coupler. The dispersive wave number in the spectral domain must have a coupler-like symmetric profile for soliton spectral tunneling to occur. We show that such a spectral coupler...

  15. Integral membrane protein structure determination using pseudocontact shifts

    Crick, Duncan J.; Wang, Jue X. [University of Cambridge, Department of Biochemistry (United Kingdom); Graham, Bim; Swarbrick, James D. [Monash University, Monash Institute of Pharmaceutical Sciences (Australia); Mott, Helen R.; Nietlispach, Daniel, E-mail: dn206@cam.ac.uk [University of Cambridge, Department of Biochemistry (United Kingdom)

    2015-04-15

    Obtaining enough experimental restraints can be a limiting factor in the NMR structure determination of larger proteins. This is particularly the case for large assemblies such as membrane proteins that have been solubilized in a membrane-mimicking environment. Whilst in such cases extensive deuteration strategies are regularly utilised with the aim to improve the spectral quality, these schemes often limit the number of NOEs obtainable, making complementary strategies highly beneficial for successful structure elucidation. Recently, lanthanide-induced pseudocontact shifts (PCSs) have been established as a structural tool for globular proteins. Here, we demonstrate that a PCS-based approach can be successfully applied for the structure determination of integral membrane proteins. Using the 7TM α-helical microbial receptor pSRII, we show that PCS-derived restraints from lanthanide binding tags attached to four different positions of the protein facilitate the backbone structure determination when combined with a limited set of NOEs. In contrast, the same set of NOEs fails to determine the correct 3D fold. The latter situation is frequently encountered in polytopical α-helical membrane proteins and a PCS approach is thus suitable even for this particularly challenging class of membrane proteins. The ease of measuring PCSs makes this an attractive route for structure determination of large membrane proteins in general.

  16. The shifting beverage landscape.

    Storey, Maureen

    2010-04-26

    STOREY, M.L. The shifting beverage landscape. PHYSIOL BEHAV, 2010. - Simultaneous lifestyle changes have occurred in the last few decades, creating an imbalance in energy intake and energy expenditure that has led to overweight and obesity. Trends in the food supply show that total daily calories available per capita increased 28% since 1970. Total energy intake among men and women has also increased dramatically since that time. Some have suggested that intake of beverages has had a disproportional impact on obesity. Data collected by the Beverage Marketing Corporation between 1988-2008 demonstrate that, in reality, fewer calories per ounce are being produced by the beverage industry. Moreover, data from the National Cancer Institute show that soft drink intake represents 5.5% of daily calories. Data from NHANES 1999-2003 vs. 2003-06 may demonstrate a shift in beverage consumption for age/gender groups, ages 6 to>60years. The beverages provided in schools have significantly changed since 2006 when the beverage industry implemented School Beverage Guidelines. This voluntary action has removed full-calorie soft drinks from participating schools across the country. This shift to lower-calorie and smaller-portion beverages in school has led to a significant decrease in total beverage calories in schools. These data support the concept that to prevent and treat obesity, public health efforts should focus on energy balance and that a narrow focus on sweetened beverages is unlikely to have any meaningful impact on this complex problem. Copyright 2010 Elsevier Inc. All rights reserved.

  17. Photoreceptor spectral sensitivity in the bumblebee, Bombus impatiens (Hymenoptera: Apidae.

    Peter Skorupski

    Full Text Available The bumblebee Bombus impatiens is increasingly used as a model in comparative studies of colour vision, or in behavioural studies relying on perceptual discrimination of colour. However, full spectral sensitivity data on the photoreceptor inputs underlying colour vision are not available for B. impatiens. Since most known bee species are trichromatic, with photoreceptor spectral sensitivity peaks in the UV, blue and green regions of the spectrum, data from a related species, where spectral sensitivity measurements have been made, are often applied to B impatiens. Nevertheless, species differences in spectral tuning of equivalent photoreceptor classes may result in peaks that differ by several nm, which may have small but significant effects on colour discrimination ability. We therefore used intracellular recording to measure photoreceptor spectral sensitivity in B. impatiens. Spectral peaks were estimated at 347, 424 and 539 nm for UV, blue and green receptors, respectively, suggesting that this species is a UV-blue-green trichromat. Photoreceptor spectral sensitivity peaks are similar to previous measurements from Bombus terrestris, although there is a significant difference in the peak sensitivity of the blue receptor, which is shifted in the short wave direction by 12-13 nm in B. impatiens compared to B. terrestris.

  18. Optimization of compressive 4D-spatio-spectral snapshot imaging

    Zhao, Xia; Feng, Weiyi; Lin, Lihua; Su, Wu; Xu, Guoqing

    2017-10-01

    In this paper, a modified 3D computational reconstruction method in the compressive 4D-spectro-volumetric snapshot imaging system is proposed for better sensing spectral information of 3D objects. In the design of the imaging system, a microlens array (MLA) is used to obtain a set of multi-view elemental images (EIs) of the 3D scenes. Then, these elemental images with one dimensional spectral information and different perspectives are captured by the coded aperture snapshot spectral imager (CASSI) which can sense the spectral data cube onto a compressive 2D measurement image. Finally, the depth images of 3D objects at arbitrary depths, like a focal stack, are computed by inversely mapping the elemental images according to geometrical optics. With the spectral estimation algorithm, the spectral information of 3D objects is also reconstructed. Using a shifted translation matrix, the contrast of the reconstruction result is further enhanced. Numerical simulation results verify the performance of the proposed method. The system can obtain both 3D spatial information and spectral data on 3D objects using only one single snapshot, which is valuable in the agricultural harvesting robots and other 3D dynamic scenes.

  19. PROBING THE SOLAR ATMOSPHERE USING OSCILLATIONS OF INFRARED CO SPECTRAL LINES

    Penn, M. J.; Schad, T.; Cox, E.

    2011-01-01

    Oscillations were observed across the whole solar disk using the Doppler shift and line center intensity of spectral lines from the CO molecule near 4666 nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and phase spectra were examined, and diagnostic diagrams reveal power ridges at the solar global mode frequencies to show that these oscillations are solar p-modes. The phase was used to determine the height of formation of the CO lines by comparison with the IR continuum intensity phase shifts as measured in Kopp et al.; we find that the CO line formation height varies from 425 km μ > 0.5. The velocity power spectra show that while the sum of the background and p-mode power increases with height in the solar atmosphere as seen in previous work, the power in the p-modes only (background subtracted) decreases with height. The CO line center intensity weakens in regions of stronger magnetic fields, as does the p-mode oscillation power. Across most of the solar surface the phase shift is larger than the expected value of 90 0 for an adiabatic atmosphere. We fit the phase spectra at different disk positions with a simple atmospheric model to determine that the acoustic cutoff frequency is about 4.5 mHz with only small variations, but that the thermal relaxation frequency drops significantly from 2.7 to 0 mHz at these heights in the solar atmosphere.

  20. Repetition and Translation Shifts

    Simon Zupan

    2006-06-01

    Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

  1. Spectral Properties of Dyes with Interfragmental Charge Transfer: Solvatochromism and Solvatofluorochromism of 2-(3-Coumaroyl-benzopyrylium Perchlorates

    Edward V. Sanin

    2014-01-01

    Full Text Available The paper deals with the spectral properties of dyes with interfragmental charge transfer, in particular, derivatives of 2-(3-coumaroylbenzopyrylium (CBP perchlorates. The positions of long-wavelength absorption and emission bands, quantum yields, and lifetimes of fluorescence were measured, mostly in aprotic solvents. Regression analysis of the relationship between the spectral characteristics of CBP and the main solvent parameters (polarity, polarisability, nucleophilicity, and electrophilicity was carried out. It was found that the characteristics of CBP depend mainly on two solvent parameters—polarity and/or nucleophilicity. An increase in these parameters results in a hypsochromic shift of absorption bands and a decrease of lifetimes and fluorescence intensity. The positions of the emission bands can demonstrate either hypsochromism or bathochromism, depending on the nature of the substituents. The solvatofluorochromic effects are not as strong as the solvatochromic ones. We believe that the spectral behaviour of CBP can be explained by cation depolarisation and by a decrease in the stability of nucleophilic complexes with solvent molecules that is associated with interfragmental charge transfer following excitation, relaxation, and radiative deactivation of the excited state.

  2. Shift Work: Improving Daytime Sleep

    ... night. Good daytime sleep is possible, though, if shift work is a necessary part of your work life. ... mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/shift-work/faq-20057991 . Mayo Clinic Footer Legal Conditions and ...

  3. On spectral pollution

    Llobet, X.; Appert, K.; Bondeson, A.; Vaclavik, J.

    1990-01-01

    Finite difference and finite element approximations of eigenvalue problems, under certain circumstances exhibit spectral pollution, i.e. the appearance of eigenvalues that do not converge to the correct value when the mesh density is increased. In the present paper this phenomenon is investigated in a homogeneous case by means of discrete dispersion relations: the polluting modes belong to a branch of the dispersion relation that is strongly distorted by the discretization method employed, or to a new, spurious branch. The analysis is applied to finite difference methods and to finite element methods, and some indications about how to avoiding polluting schemes are given. (author) 5 figs., 10 refs

  4. Spectral integration in speech and non-speech sounds

    Jacewicz, Ewa

    2005-04-01

    Spectral integration (or formant averaging) was proposed in vowel perception research to account for the observation that a reduction of the intensity of one of two closely spaced formants (as in /u/) produced a predictable shift in vowel quality [Delattre et al., Word 8, 195-210 (1952)]. A related observation was reported in psychoacoustics, indicating that when the components of a two-tone periodic complex differ in amplitude and frequency, its perceived pitch is shifted toward that of the more intense tone [Helmholtz, App. XIV (1875/1948)]. Subsequent research in both fields focused on the frequency interval that separates these two spectral components, in an attempt to determine the size of the bandwidth for spectral integration to occur. This talk will review the accumulated evidence for and against spectral integration within the hypothesized limit of 3.5 Bark for static and dynamic signals in speech perception and psychoacoustics. Based on similarities in the processing of speech and non-speech sounds, it is suggested that spectral integration may reflect a general property of the auditory system. A larger frequency bandwidth, possibly close to 3.5 Bark, may be utilized in integrating acoustic information, including speech, complex signals, or sound quality of a violin.

  5. Using chemical shift perturbation to characterise ligand binding.

    Williamson, Mike P

    2013-08-01

    Chemical shift perturbation (CSP, chemical shift mapping or complexation-induced changes in chemical shift, CIS) follows changes in the chemical shifts of a protein when a ligand is added, and uses these to determine the location of the binding site, the affinity of the ligand, and/or possibly the structure of the complex. A key factor in determining the appearance of spectra during a titration is the exchange rate between free and bound, or more specifically the off-rate koff. When koff is greater than the chemical shift difference between free and bound, which typically equates to an affinity Kd weaker than about 3μM, then exchange is fast on the chemical shift timescale. Under these circumstances, the observed shift is the population-weighted average of free and bound, which allows Kd to be determined from measurement of peak positions, provided the measurements are made appropriately. (1)H shifts are influenced to a large extent by through-space interactions, whereas (13)Cα and (13)Cβ shifts are influenced more by through-bond effects. (15)N and (13)C' shifts are influenced both by through-bond and by through-space (hydrogen bonding) interactions. For determining the location of a bound ligand on the basis of shift change, the most appropriate method is therefore usually to measure (15)N HSQC spectra, calculate the geometrical distance moved by the peak, weighting (15)N shifts by a factor of about 0.14 compared to (1)H shifts, and select those residues for which the weighted shift change is larger than the standard deviation of the shift for all residues. Other methods are discussed, in particular the measurement of (13)CH3 signals. Slow to intermediate exchange rates lead to line broadening, and make Kd values very difficult to obtain. There is no good way to distinguish changes in chemical shift due to direct binding of the ligand from changes in chemical shift due to allosteric change. Ligand binding at multiple sites can often be characterised, by

  6. Lanthanide shift reagents, binding, shift mechanisms and exchange

    Boer, J.W.M. de

    1977-01-01

    Paramagnetic lanthanide shift reagents, when added to a solution of a substrate, induce shifts in the nuclear magnetic resonance (NMR) spectrum of the substrate molecules. The induced shifts contain information about the structure of the shift reagent substrate complex. The structural information, however, may be difficult to extract because of the following effects: (1) different complexes between shift reagent and substrate may be present in solution, e.g. 1:1 and 1:2 complexes, and the shift observed is a weighed average of the shifts of the substrate nuclei in the different complexes; (2) the Fermi contact interaction, arising from the spin density at the nucleus, contributes to the induced shift; (3) chemical exchange effects may complicate the NMR spectrum. In this thesis, the results of an investigation into the influence of these effects on the NMR spectra of solutions containing a substrate and LSR are presented. The equations describing the pseudo contact and the Fermi contact shift are derived. In addition, it is shown how the modified Bloch equations describing the effect of the chemical exchange processes occurring in the systems studied can be reduced to the familiar equations for a two-site exchange case. The binding of mono- and bifunctional ethers to the shift reagent are reported. An analysis of the induced shifts is given. Finally, the results of the experiments performed to study the exchange behavior of dimethoxyethane and heptafluorodimethyloctanedionato ligands are presented

  7. Faktor Dan Penjadualan Shift Kerja

    Maurits, Lientje Setyawati; Widodo, Imam Djati

    2008-01-01

    Work shift has negative effect in physical and mental health, work performance and job accident. Disturbance of circadian rhythms is indicated as source of the problems. This article explores some researches related to the impacts of work shift and establishes basic principles of work shift scheduling that considers human need and limitation.

  8. Isotope shifting capacity of rock

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  9. New Spectral Features from Bound Dark Matter

    Catena, Riccardo; Kouvaris, Chris

    2016-01-01

    We demonstrate that dark matter particles gravitationally bound to the Earth can induce a characteristic nuclear recoil signal at low energies in direct detection experiments. The new spectral feature we predict can provide the ultimate smoking gun for dark matter discovery for experiments...... with positive signal but unclear background. The new feature is universal, in that the ratio of bound over halo dark matter event rates at detectors is independent of the dark matter-nucleon cross section....

  10. The shift in windpower

    Gipe, P.

    1992-01-01

    Despite new production records, the near-term market for new windpower projects in the US remains bleak. Congressional incentives and project proposals in the mid-1990s offer promise, but for now most development has shifted to Europe. During 1992 and 1993 the largest wind projects developed by US companies will not be in the US, but in the United Kingdom and Spain. Indeed, most of the US's windpower industry is going abroad, establishing offices overseas. This move toward Europe comes as little surprise. New project development for US firms has faltered at home while the European market has burgeoned. The topics of the article include the move to Europe, a reduction in California's share of producing wind power plants, a rise in Europe's share of producing wind power plants, the future market for wind power in the US, and reawakening California's market

  11. Dynamics of spectral components of heart rate variability during changes in autonomic balance

    Højgaard, M V; Holstein-Rathlou, N H; Agner, E

    1998-01-01

    Frequency domain analysis of heart rate variability (HRV) has been proposed as a semiquantitative method for assessing activities in the autonomic nervous system. We examined whether absolute powers, normalized powers, and the low frequency-to-high frequency ratio (LF/HF) derived from the HRV power...... spectrum could detect shifts in autonomic balance in a setting with low sympathetic nervous tone. Healthy subjects were examined for 3 h in the supine position during 1) control conditions (n = 12), 2) acute beta-blockade (n = 11), and 3) chronic beta-blockade (n = 10). Heart rate fell during the first 40...... min of the control session (72 +/- 2 to 64 +/- 2 beats/min; P powers of all spectral areas rose during the first 60 min in all three settings, more so with beta-blockade (P

  12. Noninvasive diagnosis of oral cancer by Stokes shift spectroscopy

    Ebenezar, Jeyasingh; Ganesan, Singaravelu; Aruna, Prakasrao; Muralinaidu, Radhakrishnan

    2014-03-01

    The objective of this study is to evaluate the diagnostic potential of stokes shift (SS) spectroscopy (S3) for normal, precancer and cancerous oral lesions in vivo. The SS spectra were recorded in the 250 - 650 nm spectral range by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological oral lesions observed around 300, 355, 395, and 420 nm which are attributed to tryptophan, collagen, and NADH respectively. Using S3 technique one can obtain the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological oral lesions are verified by different ratio parameters.

  13. Rectangular spectral collocation

    Driscoll, Tobin A.

    2015-02-06

    Boundary conditions in spectral collocation methods are typically imposed by removing some rows of the discretized differential operator and replacing them with others that enforce the required conditions at the boundary. A new approach based upon resampling differentiated polynomials into a lower-degree subspace makes differentiation matrices, and operators built from them, rectangular without any row deletions. Then, boundary and interface conditions can be adjoined to yield a square system. The resulting method is both flexible and robust, and avoids ambiguities that arise when applying the classical row deletion method outside of two-point scalar boundary-value problems. The new method is the basis for ordinary differential equation solutions in Chebfun software, and is demonstrated for a variety of boundary-value, eigenvalue and time-dependent problems.

  14. Spectral evolution of galaxies

    Rocca-Volmerange, B.

    1989-01-01

    A recent striking event in Observational Cosmology is the discovery of a large population of galaxies at extreme cosmological distances (extended from spectral redshifts ≅ 1 to ≥ 3) corresponding to a lookback time of 80% of the Universe's age. However when galaxies are observed at such remote epochs, their appearances are affected by at least two simultaneous effects which are respectively a cosmological effect and the intrinsic evolution of their stellar populations which appear younger than in our nearby galaxies. The fundamental problem is first to disentangle the respective contributions of these two effects to apparent magnitudes and colors of distant galaxies. Other effects which are likely to modify the appearance of galaxies are amplification by gravitational lensing and interaction with environment will also be considered. (author)

  15. Spectral Line Shapes. Proceedings

    Zoppi, M.; Ulivi, L.

    1997-01-01

    These proceedings represent papers presented at the 13th International Conference on Spectral Line Shapes which was held in Firenze,Italy from June 16-21, 1996. The topics covered a wide range of subjects emphasizing the physical processes associated with the formation of line profiles: high and low density plasma; atoms and molecules in strong laser fields, Dopple-free and ultra-fine spectroscopy; the line shapes generated by the interaction of neutrals, atoms and molecules, where the relavant quantities are single particle properties, and the interaction-induced spectroscopy. There were 131 papers presented at the conference, out of these, 6 have been abstracted for the Energy Science and Technology database

  16. ATR neutron spectral characterization

    Rogers, J.W.; Anderl, R.A.

    1995-11-01

    The Advanced Test Reactor (ATR) at INEL provides intense neutron fields for irradiation-effects testing of reactor material samples, for production of radionuclides used in industrial and medical applications, and for scientific research. Characterization of the neutron environments in the irradiation locations of the ATR has been done by means of neutronics calculations and by means of neutron dosimetry based on the use of neutron activation monitors that are placed in the various irradiation locations. The primary purpose of this report is to present the results of an extensive characterization of several ATR irradiation locations based on neutron dosimetry measurements and on least-squares-adjustment analyses that utilize both neutron dosimetry measurements and neutronics calculations. This report builds upon the previous publications, especially the reference 4 paper. Section 2 provides a brief description of the ATR and it tabulates neutron spectral information for typical irradiation locations, as derived from the more historical neutron dosimetry measurements. Relevant details that pertain to the multigroup neutron spectral characterization are covered in section 3. This discussion includes a presentation on the dosimeter irradiation and analyses and a development of the least-squares adjustment methodology, along with a summary of the results of these analyses. Spectrum-averaged cross sections for neutron monitoring and for displacement-damage prediction in Fe, Cr, and Ni are given in section 4. In addition, section4 includes estimates of damage generation rates for these materials in selected ATR irradiation locations. In section 5, the authors present a brief discussion of the most significant conclusions of this work and comment on its relevance to the present ATR core configuration. Finally, detailed numerical and graphical results for the spectrum-characterization analyses in each irradiation location are provided in the Appendix.

  17. Spectral Theory of Chemical Bonding

    Langhoff, P. W; Boatz, J. A; Hinde, R. J; Sheehy, J. A

    2004-01-01

    .... Wave function antisymmetry in the aggregate atomic spectral-product basis is enforced by unitary transformation performed subsequent to formation of the Hamiltonian matrix, greatly simplifying its construction...

  18. [Review of digital ground object spectral library].

    Zhou, Xiao-Hu; Zhou, Ding-Wu

    2009-06-01

    A higher spectral resolution is the main direction of developing remote sensing technology, and it is quite important to set up the digital ground object reflectance spectral database library, one of fundamental research fields in remote sensing application. Remote sensing application has been increasingly relying on ground object spectral characteristics, and quantitative analysis has been developed to a new stage. The present article summarized and systematically introduced the research status quo and development trend of digital ground object reflectance spectral libraries at home and in the world in recent years. Introducing the spectral libraries has been established, including desertification spectral database library, plants spectral database library, geological spectral database library, soil spectral database library, minerals spectral database library, cloud spectral database library, snow spectral database library, the atmosphere spectral database library, rocks spectral database library, water spectral database library, meteorites spectral database library, moon rock spectral database library, and man-made materials spectral database library, mixture spectral database library, volatile compounds spectral database library, and liquids spectral database library. In the process of establishing spectral database libraries, there have been some problems, such as the lack of uniform national spectral database standard and uniform standards for the ground object features as well as the comparability between different databases. In addition, data sharing mechanism can not be carried out, etc. This article also put forward some suggestions on those problems.

  19. Two hierarchies of integrable lattice equations associated with a discrete matrix spectral problem

    Li Xinyue; Xu Xixiang; Zhao Qiulan

    2008-01-01

    Two hierarchies of nonlinear integrable positive and negative lattice models are derived from a discrete spectral problem. The two lattice hierarchies are proved to have discrete zero curvature representations associated with a discrete spectral problem, which also shows that the positive and negative hierarchies correspond to positive and negative power expansions of Lax operators with respect to the spectral parameter, respectively. Moreover, the integrable lattice models in the positive hierarchy are of polynomial type, and the integrable lattice models in the negative hierarchy are of rational type. Further, we construct infinite conservation laws of the positive hierarchy, then, the integrable coupling systems of the positive hierarchy are derived from enlarging Lax pair

  20. Effects of asynchrony and ear of presentation on the pitch of mistuned partials in harmonic and frequency-shifted complex tones.

    Brunstrom, J M; Roberts, B

    2001-07-01

    When a partial of a periodic complex is mistuned, its change in pitch is greater than expected. Two experiments examined whether these partial-pitch shifts are related to the computation of global pitch. In experiment 1, stimuli were either harmonic or frequency-shifted (25% of F0) complexes. One partial was mistuned by +/- 4% and played with leading and lagging portions of 500 ms each, relative to the other components (1 s), in both monaural and dichotic contexts. Subjects indicated whether the mistuned partial was higher or lower in pitch when concurrent with the other components. Responses were positively correlated with the direction of mistuning in all conditions. In experiment 2, stimuli from each condition were compared with synchronous equivalents. Subjects matched a pure tone to the pitch of the mistuned partial (component 4). The results showed that partial-pitch shifts are not reduced in size by asynchrony. Similar asynchronies are known to produce a near-exclusion of a mistuned partial from the global-pitch computation. This mismatch indicates that global and partial pitch are derived from different processes. The similarity of the partial-pitch shifts observed for harmonic and frequency-shifted stimuli suggests that they arise from a grouping mechanism that is sensitive to spectral regularity.

  1. Spatial variability of oceanic phycoerythrin spectral types derived from airborne laser-induced fluorescence emissions

    Hoge, Frank E.; Wright, C. Wayne; Kana, Todd M.; Swift, Robert N.; Yungel, James K.

    1998-07-01

    We report spatial variability of oceanic phycoerythrin spectral types detected by means of a blue spectral shift in airborne laser-induced fluorescence emission. The blue shift of the phycoerythrobilin fluorescence is known from laboratory studies to be induced by phycourobilin chromophore substitution at phycoerythrobilin chromophore sites in some strains of phycoerythrin-containing marine cyanobacteria. The airborne 532-nm laser-induced phycoerythrin fluorescence of the upper oceanic volume showed distinct segregation of cyanobacterial chromophore types in a flight transect from coastal water to the Sargasso Sea in the western North Atlantic. High phycourobilin levels were restricted to the oceanic (oligotrophic) end of the flight transect, in agreement with historical ship findings. These remotely observed phycoerythrin spectral fluorescence shifts have the potential to permit rapid, wide-area studies of the spatial variability of spectrally distinct cyanobacteria, especially across interfacial regions of coastal and oceanic water masses. Airborne laser-induced phytoplankton spectral fluorescence observations also further the development of satellite algorithms for passive detection of phytoplankton pigments. Optical modifications to the NASA Airborne Oceanographic Lidar are briefly described that permitted observation of the fluorescence spectral shifts.

  2. Variational principles for the spectral radius of functional operators

    Antonevich, A B; Zajkowski, K

    2006-01-01

    The spectral radius of a functional operator with positive coefficients generated by a set of maps (a dynamical system) is shown to be a logarithmically convex functional of the logarithms of the coefficients. This yields the following variational principle: the logarithm of the spectral radius is the Legendre transform of a convex functional T defined on a set of vector-valued probability measures and depending only on the original dynamical system. A combinatorial construction of the functional T by means of the random walk process corresponding to the dynamical system is presented in the subexponential case. Examples of the explicit calculation of the functional T and the spectral radius are presented.

  3. Chemical shift homology in proteins

    Potts, Barbara C.M.; Chazin, Walter J.

    1998-01-01

    The degree of chemical shift similarity for homologous proteins has been determined from a chemical shift database of over 50 proteins representing a variety of families and folds, and spanning a wide range of sequence homologies. After sequence alignment, the similarity of the secondary chemical shifts of C α protons was examined as a function of amino acid sequence identity for 37 pairs of structurally homologous proteins. A correlation between sequence identity and secondary chemical shift rmsd was observed. Important insights are provided by examining the sequence identity of homologous proteins versus percentage of secondary chemical shifts that fall within 0.1 and 0.3 ppm thresholds. These results begin to establish practical guidelines for the extent of chemical shift similarity to expect among structurally homologous proteins

  4. Reflectionless discrete Schr\\"odinger operators are spectrally atypical

    VandenBoom, Tom

    2017-01-01

    We prove that, if an isospectral torus contains a discrete Schr\\"odinger operator with nonconstant potential, the shift dynamics on that torus cannot be minimal. Consequently, we specify a generic sense in which finite unions of nondegenerate closed intervals having capacity one are not the spectrum of any reflectionless discrete Schr\\"odinger operator. We also show that the only reflectionless discrete Schr\\"odinger operators having zero, one, or two spectral gaps are periodic.

  5. Reflectionless Discrete Schrödinger Operators are Spectrally Atypical

    VandenBoom, Tom

    2017-12-01

    We prove that, if an isospectral torus contains a discrete Schrödinger operator with nonconstant potential, the shift dynamics on that torus cannot be minimal. Consequently, we specify a generic sense in which finite unions of nondegenerate closed intervals having capacity one are not the spectrum of any reflectionless discrete Schrödinger operator. We also show that the only reflectionless discrete Schrödinger operators having zero, one, or two spectral gaps are periodic.

  6. A strontium lattice clock with reduced blackbody radiation shift

    Al-Masoudi, Ali Khalas Anfoos

    2016-09-30

    Optical clocks have been quickly moving to the forefront of the frequency standards field due to their high spectral resolution, and therefore the potential high stability and accuracy. The accuracy and stability of the optical clocks are nowadays two orders of magnitude better than microwave Cs clocks, which realize the SI second. Envisioned applications of highly accurate optical clocks are to perform tests of fundamental physics, for example, searching for temporal drifts of the fine structure constant α, violations of the Local Position Invariance (LPI), dark matter and dark energy, or to performance relativistic geodesy. In this work, the uncertainty of a strontium lattice clock, based on the {sup 1}S{sub 0}-{sup 3}P{sub 0} transition in {sup 87}Sr, due to the blackbody radiation (BBR) shift has been reduced to less than 1 x 10{sup -18} by more than one order of magnitude compared to the previous evaluation of the BBR shift uncertainty in this clock. The BBR shift has been reduced by interrogating the atoms in a cryogenic environment. The systematic uncertainty of the cryogenic lattice clock is evaluated to be 1.3 x 10{sup -17} which is dominated by the uncertainty of the AC Stark shift of the lattice laser and the uncertainty contribution of the BBR shift is negligible. Concerning the instability of the clock, the detection noise of the clock has been measured, and a model linking noise and clock instability has been developed. This noise model shows that, in our lattice clock, quantum projection noise is reached if more than 130 atoms are interrogated. By combining the noise model with the degradation due to the Dick effect reflecting the frequency noise of the interrogation laser, the instability of the clock is estimated to be 1.6 x 10{sup -16}/√(τ/s) in regular operation. During this work, several high-accuracy comparisons to other atomic clocks have been performed, including several absolute frequency measurements. The Sr clock transition frequency

  7. Shifted-modified Chebyshev filters

    ŞENGÜL, Metin

    2013-01-01

    This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain, group dela...

  8. On spectral subspaces and their applications to automorphism groups

    Olesen, Dorte

    1974-03-01

    An attempt is made to give a survey of the theory of spectra and spectral subspaces of group representations in an abstract Banach space setting. The theory is applied to the groups of automorphisms of operator algebras (mostly C*-algebras) and some important results of interest for mathematical physicists are proved (restrictions of the bitransposed action, spectral subspaces for the transposed action on a C*-algebra, and positive states and representations of Rsup(n)) [fr

  9. An implicit spectral formula for generalized linear Schroedinger equations

    Schulze-Halberg, A.; Garcia-Ravelo, J.; Pena Gil, Jose Juan

    2009-01-01

    We generalize the semiclassical Bohr–Sommerfeld quantization rule to an exact, implicit spectral formula for linear, generalized Schroedinger equations admitting a discrete spectrum. Special cases include the position-dependent mass Schroedinger equation or the Schroedinger equation for weighted energy. Requiring knowledge of the potential and the solution associated with the lowest spectral value, our formula predicts the complete spectrum in its exact form. (author)

  10. Portable shift register

    Halbig, J.K.; Bourret, S.C.; Hansen, W.J.; Hicks, D.V.; Klosterbuer, S.F.; Krick, M.S.

    1994-01-01

    An electronics package for a small, battery-operated, self-contained, neutron coincidence counter based on a portable shift-register (PSR) has been developed. The counter was developed for applications not adequately addressed by commercial packages, including in-plant measurements to demonstrate compliance with regulations (domestic and international), in-plant process control, and in-field measurements (environmental monitoring or safeguards). Our package's features, which address these applications, include the following: Small size for portability and ease of installation;battery or mains operation; a built-in battery to power the unit and a typical detector such as a small sample counter, for over 6 h if power lines are bad or noisy, if there is a temporary absence of power, or if portability is desired; complete support, including bias, for standard neutron detectors; a powerful communications package to easily facilitate robust external control over a serial port; and a C-library to simplify creating external control programs in computers or other controllers. Whereas the PSR specifically addresses the applications mentioned above, it also performs all the measurements made by previous electronics packages for neutron coincidence counters developed at Los Alamos and commercialized. The PSR electronics package, exclusive of carrying handle, is 8 by 10 by 20 cm; it contains the circuit boards, battery, and bias supply and weighs less than 2 kg. This instrument package is the second in an emerging family of portable measurement instruments being developed; the first was the Miniature and Modular Multichannel Analyzer (M 3 CA). The PSR makes extensive use of hardware and software developed for the M 3 CA; like the M 3 CA, it is intended primarily for use with an external controller interfaced over a serial channel

  11. Luminosity and Redshift dependence of quasar spectral properties

    Daniel E. Vanden Berk et al.

    2004-03-09

    Using a large sample of quasar spectra from the SDSS, we examine the composite spectral trends of quasars as functions of both redshift and luminosity, independently of one another. Aside from the well known Baldwin effect (BE)--the decrease of line equivalent width with luminosity--the average spectral properties are remarkably similar. Host galaxy contamination and the BE are the primary causes for apparent changes in the average spectral slope of the quasars. The BE is detected for most emission lines, including the Balmer lines, but with several exceptions including NV1240A. Emission line shifts of several lines are associated with the BE. The BE is mainly a function of luminosity, but also partly a function of redshift in that line equivalent widths become stronger with redshift. Some of the complex iron features change with redshift, particularly near the small blue bump region.

  12. Spectral density and a family of Dirac operators

    Niemi, A.J.

    1985-01-01

    The spectral density for a class Dirac operators is investigated by relating its even and odd parts to the Riemann zeta-function and to the eta-invariant by Atiyah, Padoti and Singer. Asymptotic expansions are studied and a 'hidden' supersymmetry is revealed and used to relate the Dirac operator to a supersymmetric quantum mechanics. A general method for the computation of the odd spectral density is developed, and various applications are discussed. In particular the connection to the fermion number and a relation between the odd spectral density and some ratios of Jost functions and relative phase shifts are pointed out. Chiral symmetry breaking is investigated using methods analogous to those applied in the investigation of the fermion number, and related to supersymmetry breaking in the corresponding quantum mechanical model. (orig.)

  13. Metabolic syndrome in fixed-shift workers.

    Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status), socioeconomic (educational level, income and work shift), and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration) of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2). The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2), followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64), workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93) and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24). On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73). CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  14. Metabolic syndrome in fixed-shift workers

    Raquel Canuto

    2015-01-01

    Full Text Available OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status, socioeconomic (educational level, income and work shift, and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2. The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2, followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64, workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93 and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24. On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73. CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  15. PHOTOMETRIC AND SPECTRAL SIGNATURES OF THREE-DIMENSIONAL MODELS OF TRANSITING GIANT EXOPLANETS

    Burrows, A.; Spiegel, D. S.; Rauscher, E.; Menou, K.

    2010-01-01

    Using a three-dimensional general circulation model, we create dynamical model atmospheres of a representative transiting giant exoplanet, HD 209458b. We post-process these atmospheres with an opacity code to obtain transit radius spectra during the primary transit. Using a spectral atmosphere code, we integrate over the face of the planet seen by an observer at various orbital phases and calculate light curves as a function of wavelength and for different photometric bands. The products of this study are generic predictions for the phase variations of a zero-eccentricity giant planet's transit spectrum and of its light curves. We find that for these models the temporal variations in all quantities and the ingress/egress contrasts in the transit radii are small (<1.0%). Moreover, we determine that the day/night contrasts and phase shifts of the brightness peaks relative to the ephemeris are functions of photometric band. The J, H, and K bands are shifted most, while the IRAC bands are shifted least. Therefore, we verify that the magnitude of the downwind shift in the planetary 'hot spot' due to equatorial winds is strongly wavelength dependent. The phase and wavelength dependence of light curves, as well as the associated day/night contrasts, can be used to constrain the circulation regime of irradiated giant planets and to probe different pressure levels of a hot Jupiter atmosphere. We posit that though our calculations focus on models of HD 209458b, similar calculations for other transiting hot Jupiters in low-eccentricity orbits should yield transit spectra and light curves of a similar character.

  16. Quantized beam shifts in graphene

    de Melo Kort-Kamp, Wilton Junior [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinitsyn, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalvit, Diego Alejandro Roberto [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-08

    We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant α, while the Goos-Hanchen ones in multiples of α2. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  17. Chemical shift-dependent apparent scalar couplings: An alternative concept of chemical shift monitoring in multi-dimensional NMR experiments

    Kwiatkowski, Witek; Riek, Roland

    2003-01-01

    The paper presents an alternative technique for chemical shift monitoring in a multi-dimensional NMR experiment. The monitored chemical shift is coded in the line-shape of a cross-peak through an apparent residual scalar coupling active during an established evolution period or acquisition. The size of the apparent scalar coupling is manipulated with an off-resonance radio-frequency pulse in order to correlate the size of the coupling with the position of the additional chemical shift. The strength of this concept is that chemical shift information is added without an additional evolution period and accompanying polarization transfer periods. This concept was incorporated into the three-dimensional triple-resonance experiment HNCA, adding the information of 1 H α chemical shifts. The experiment is called HNCA coded HA, since the chemical shift of 1 H α is coded in the line-shape of the cross-peak along the 13 C α dimension

  18. SPECTRAL ANALYSIS OF EXCHANGE RATES

    ALEŠA LOTRIČ DOLINAR

    2013-06-01

    Full Text Available Using spectral analysis is very common in technical areas but rather unusual in economics and finance, where ARIMA and GARCH modeling are much more in use. To show that spectral analysis can be useful in determining hidden periodic components for high-frequency finance data as well, we use the example of foreign exchange rates

  19. ULTRAVIOLET RAMAN SPECTRAL SIGNATURE ACQUISITION: UV RAMAN SPECTRAL FINGERPRINTS.

    SEDLACEK,III, A.J.FINFROCK,C.

    2002-09-01

    As a member of the science-support part of the ITT-lead LISA development program, BNL is tasked with the acquisition of UV Raman spectral fingerprints and associated scattering cross-sections for those chemicals-of-interest to the program's sponsor. In support of this role, the present report contains the first installment of UV Raman spectral fingerprint data on the initial subset of chemicals. Because of the unique nature associated with the acquisition of spectral fingerprints for use in spectral pattern matching algorithms (i.e., CLS, PLS, ANN) great care has been undertaken to maximize the signal-to-noise and to minimize unnecessary spectral subtractions, in an effort to provide the highest quality spectral fingerprints. This report is divided into 4 sections. The first is an Experimental section that outlines how the Raman spectra are performed. This is then followed by a section on Sample Handling. Following this, the spectral fingerprints are presented in the Results section where the data reduction process is outlined. Finally, a Photographs section is included.

  20. The effect of silver on the optical, spectral-luminescent, and crystallization properties of bromide photo-thermo-refractive glasses

    Oreshkina, K. V.; Dubrovin, V. D.; Ignat'ev, A. I.; Nikonorov, N. V.

    2017-10-01

    The effect of silver on the optical, spectral-luminescent, and crystallization properties of bromide photo-thermo-refractive glasses is studied. Multicomponent photosensitive glasses of the Na2O-ZnO-Al2O3-SiO2 system with photosensitizing agents (cerium, antimony, silver) and halogenides (fluorine and bromine) are synthesized. Ultraviolet irradiation and thermal treatment below the glass-transition temperature of the glasses cause the formation of silver molecular clusters, which exhibit luminescence in the visible and infrared regions. UV irradiation and thermal treatment of glasses above the glass-transition temperature lead to the growth of silver nanoparticles with plasmon resonance peak in the region of 420 nm. Further thermal treatment of glasses above the glass-transition temperature shifts the plasmon-resonance maximum by 70 nm to longer wavelengths, which is related to the growth of a crystalline shell consisting of mixed silver and sodium bromides on nanoparticles. This formation of a crystalline phase on colloidal centers results in a local increase in the refractive index of the irradiated region by +Δ n 900 ppm compared to the nonirradiated region. Photo-thermo-refractive glasses with increased silver concentration are promising photosensitive materials for creating holographic optical elements and devices for line narrowing and stabilizing filters, spectral beam combiners, and filters for increasing the spectral brightness of laser diodes. A positive change in the refractive index of Photo-thermo-refractive glasses provides the possibility of recording in them 3D waveguide and integrated-optical structures.

  1. Discrepancy and Disliking Do Not Induce Negative Opinion Shifts

    Flache, Andreas; Mäs, Michael

    2016-01-01

    Both classical social psychological theories and recent formal models of opinion differentiation and bi-polarization assign a prominent role to negative social influence. Negative influence is defined as shifts away from the opinion of others and hypothesized to be induced by discrepancy with or disliking of the source of influence. There is strong empirical support for the presence of positive social influence (a shift towards the opinion of others), but evidence that large opinion differences or disliking could trigger negative shifts is mixed. We examine positive and negative influence with controlled exposure to opinions of other individuals in one experiment and with opinion exchange in another study. Results confirm that similarities induce attraction, but results do not support that discrepancy or disliking entails negative influence. Instead, our findings suggest a robust positive linear relationship between opinion distance and opinion shifts. PMID:27333160

  2. EXOPLANETARY DETECTION BY MULTIFRACTAL SPECTRAL ANALYSIS

    Agarwal, Sahil; Wettlaufer, John S. [Program in Applied Mathematics, Yale University, New Haven, CT (United States); Sordo, Fabio Del [Department of Astronomy, Yale University, New Haven, CT (United States)

    2017-01-01

    Owing to technological advances, the number of exoplanets discovered has risen dramatically in the last few years. However, when trying to observe Earth analogs, it is often difficult to test the veracity of detection. We have developed a new approach to the analysis of exoplanetary spectral observations based on temporal multifractality, which identifies timescales that characterize planetary orbital motion around the host star and those that arise from stellar features such as spots. Without fitting stellar models to spectral data, we show how the planetary signal can be robustly detected from noisy data using noise amplitude as a source of information. For observation of transiting planets, combining this method with simple geometry allows us to relate the timescales obtained to primary and secondary eclipse of the exoplanets. Making use of data obtained with ground-based and space-based observations we have tested our approach on HD 189733b. Moreover, we have investigated the use of this technique in measuring planetary orbital motion via Doppler shift detection. Finally, we have analyzed synthetic spectra obtained using the SOAP 2.0 tool, which simulates a stellar spectrum and the influence of the presence of a planet or a spot on that spectrum over one orbital period. We have demonstrated that, so long as the signal-to-noise-ratio ≥ 75, our approach reconstructs the planetary orbital period, as well as the rotation period of a spot on the stellar surface.

  3. Gap timing and the spectral timing model.

    Hopson, J W

    1999-04-01

    A hypothesized mechanism underlying gap timing was implemented in the Spectral Timing Model [Grossberg, S., Schmajuk, N., 1989. Neural dynamics of adaptive timing and temporal discrimination during associative learning. Neural Netw. 2, 79-102] , a neural network timing model. The activation of the network nodes was made to decay in the absence of the timed signal, causing the model to shift its peak response time in a fashion similar to that shown in animal subjects. The model was then able to accurately simulate a parametric study of gap timing [Cabeza de Vaca, S., Brown, B., Hemmes, N., 1994. Internal clock and memory processes in aminal timing. J. Exp. Psychol.: Anim. Behav. Process. 20 (2), 184-198]. The addition of a memory decay process appears to produce the correct pattern of results in both Scalar Expectancy Theory models and in the Spectral Timing Model, and the fact that the same process should be effective in two such disparate models argues strongly that process reflects a true aspect of animal cognition.

  4. Spectral Hounsfield units: a new radiological concept

    Hurrell, Michael Anthony; Butler, Anthony Philip Howard; Cook, Nicholas James; Butler, Philip Howard; Ronaldson, J.P.; Zainon, Rafidah

    2012-01-01

    Computed tomography (CT) uses radiographical density to depict different materials; although different elements have different absorption fingerprints across the range of diagnostic X-ray energies, this spectral absorption information is lost in conventional CT. The recent development of dual energy CT (DECT) allows extraction of this information to a useful but limited extent. However, the advent of new photon counting chips that have energy resolution capabilities has put multi-energy or spectral CT (SCT) on the clinical horizon. This paper uses a prototype SCT system to demonstrate how CT density measurements vary with kilovoltage. While radiologists learn about linear attenuation curves during radiology training, they do not usually need a detailed understanding of this phenomenon in their clinical practice. However SCT requires a paradigm shift in how radiologists think about CT density. Because radiologists are already familiar with the Hounsfield Unit (HU), it is proposed that a modified HU be used that includes the mean energy used to obtain the image, as a conceptual bridge between conventional CT and SCT. A suggested format would be: HU keV . (orig.)

  5. Work shifts in Emergency Medicine

    Roberto Recupero

    2007-06-01

    Full Text Available Emergency Medicine is known as a high stress specialty. The adverse effect of constantly rotating shifts is the single most important reason given for premature attrition from the field. In this work problems tied with night shift work will be taken into account and some solutions to reduce the impact of night work on the emergency physicians will be proposed.

  6. Flexible Schedules and Shift Work.

    Beers, Thomas M.

    2000-01-01

    Flexible work hours have gained prominence, as more than 25 million workers (27.6% of all full-time workers) can now vary their schedules. However, there has been little change since the mid-1980s in the proportion who work a shift other than a regular daytime shift. (JOW)

  7. Spectral Characteristics of Salinized Soils during Microbial Remediation Processes.

    Ma, Chuang; Shen, Guang-rong; Zhi, Yue-e; Wang, Zi-jun; Zhu, Yun; Li, Xian-hua

    2015-09-01

    In this study, the spectral reflectance of saline soils, the associated soil salt content (SSC) and the concentrations of salt ions were measured and analysed by tracing the container microbial remediation experiments for saline soil (main salt is sodium chloride) of Dongying City, Shandong Province. The sensitive spectral reflectance bands of saline soils to SSC, Cl- and Na+ in the process of microbial remediation were analysed. The average-dimension reduction of these bands was conducted by using a combination of correlation coefficient and decision coefficient, and by gradually narrowing the sampling interval method. Results showed that the tendency and magnitude of the average spectral reflectance in all bands of saline soils during the total remediation processes were nearly consistent with SSC and with Cl- coocentration, respectively. The degree of salinity of the soil, including SSC and salt ion concentrations, had a significant positive correlation with the spectral reflectance of all bands, particularly in the near-infrared band. The optimal spectral bands of SSC were 1370 to 1445 nm and 1447 to 1608 nm, whereas the optimal spectral bands of Cl- and Na+ were 1336 to 1461 nm and 1471 to 1561 nm, respectively. The relationship model among SSC, soil salt ion concentrations (Cl- and Na+) and soil spectral reflectance of the corresponding optimal spectral band was established. The largest R2 of relationship model between SSC and the average reflectance of associated optimal band reached to 0.95, and RMSEC and RMSEP were 1.076 and 0.591, respectively. Significant statistical analysis of salt factors and soil reflectance for different microbial remediation processes indicated that the spectral response characteristics and sensitivity of SSC to soil reflectance, which implied the feasibility of high spectrum test on soil microbial remediation monitoring, also provided the basis for quick nondestructive monitoring soil bioremediation process by soil spectral

  8. SOSPEX, an interactive tool to explore SOFIA spectral cubes

    Fadda, Dario; Chambers, Edward T.

    2018-01-01

    We present SOSPEX (SOFIA SPectral EXplorer), an interactive tool to visualize and analyze spectral cubes obtained with the FIFI-LS and GREAT instruments onboard the SOFIA Infrared Observatory. This software package is written in Python 3 and it is available either through Github or Anaconda.Through this GUI it is possible to explore directly the spectral cubes produced by the SOFIA pipeline and archived in the SOFIA Science Archive. Spectral cubes are visualized showing their spatial and spectral dimensions in two different windows. By selecting a part of the spectrum, the flux from the corresponding slice of the cube is visualized in the spatial window. On the other hand, it is possible to define apertures on the spatial window to show the corresponding spectral energy distribution in the spectral window.Flux isocontours can be overlapped to external images in the spatial window while line names, atmospheric transmission, or external spectra can be overplotted on the spectral window. Atmospheric models with specific parameters can be retrieved, compared to the spectra and applied to the uncorrected FIFI-LS cubes in the cases where the standard values give unsatisfactory results. Subcubes can be selected and saved as FITS files by cropping or cutting the original cubes. Lines and continuum can be fitted in the spectral window saving the results in Jyson files which can be reloaded later. Finally, in the case of spatially extended observations, it is possible to compute spectral momenta as a function of the position to obtain velocity dispersion maps or velocity diagrams.

  9. Shift schedule, work–family relationships, marital communication, job satisfaction and health among transport service shift workers

    Irena Iskra-Golec

    2017-02-01

    Full Text Available Objectives: Existing research has documented that shiftwork consequences may depend on the shift system parameters. Fast rotating systems (1–3 shifts of the same kind in a row and day work have been found to be less disruptive biologically and socially than slower rotating systems and afternoon and night work. The aim of this study was to compare day workers and shift workers of different systems in terms of rotation speed and shifts worked with regard to work–family and family–work positive and negative spillover, marital communication style, job satisfaction and health. Material and Methods: Employees (N = 168 of the maintenance workshops of transportation service working different shift systems (day shift, weekly rotating 2 and 3‑shift system, and fast rotating 3-shift system participated in the study. They completed the Work– Family Spillover Questionnaire, Marital Communication Questionnaire, Minnesota Job Satisfaction Questionnaire and the Physical Health Questionnaire (a part of the Standard Shiftwork Index. Results: The workers of quicker rotating 3-shift systems reported significantly higher scores of family-to-work facilitation (F(3, 165 = 4.175, p = 0.007 and a higher level of constructive style of marital communication (Engagement F(3, 165 = 2.761, p = 0.044 than the workers of slower rotating 2-shift systems. There were no differences between the groups of workers with regard to health and job satisfaction. Conclusions: A higher level of work–family facilitation and a more constructive style of marital communication were found among the workers of faster rotating 3-shift system when compared to the workers of a slower rotating 2-shift system (afternoon, night. This may indicate that the fast rotating shift system in contrary to the slower rotating one is more friendly for the work and family domains and for the relationship between them. Int J Occup Med Environ Health 2017;30(1:121–131

  10. Clinical Positioning Space

    Williams, Lars Peter Hedegaard; Christensen, Mette Krogh; Rytter, Carsten

    2014-01-01

    In this article, we present a case study of residents’ clinical experiences and communication in outpatient oncology consultations. We apply positioning theory, a dynamic alternative to role theory, to investigate how oncology residents and patients situate themselves as persons with rights...... and duties. Drawing from seven qualitative interviews and six days of observation, we investigate the residents’ social positioning and their conversations with patients or supervisors. Our focus is on how (a) relational shifts in authority depend on each situation and its participants; (b) storylines...... establish acts and positions and narratively frame what participants can expect from a medical consultation viewed as a social episode; and (c) the positioning of rights and duties can lead to misunderstandings and frustrations. We conclude that residents and patients locate themselves in outpatient...

  11. Association between rotating night shift work and metabolic syndrome in Korean workers: differences between 8-hour and 12-hour rotating shift work.

    Oh, Jae-Il; Yim, Hyeon Woo

    2018-02-07

    This study aimed to analyze the association between the shift work schedule and metabolic syndrome (MetS). This is a retrospective longitudinal study based on the 2015 health checkup data of 2,090 workers evaluated for MetS in 2010 at a general hospital in Korea. The participants were divided according to their shift work schedule into daytime, three-shift (8-h rotation), and two-shift (12-h rotation) workers. The index that indicates the association between the shift work schedule and MetS is the odds ratio (OR) calculated using multivariate logistic regression. The analysis for the entire group of workers indicated that there was positive association between two-shift rotation and MetS (OR=1.58, 95% confidence interval [CI]: 1.09, 2.29). In the analysis of rotating night-shift workers, the years of rotating night shifts, frequency of night-shift work, and sleep disturbance were added to the confounding variables, and two-shift work remained positively associated with MetS (OR=1.72, 95% CI: 1.10, 2.70). The risk of MetS differs based on the shift work schedules they engage in. Hence, structural changes to the shift work schedules are required to prevent MetS in night-shift workers.

  12. Position Information

    Social Security Administration — The Position Information Data Asset provides the ability to search for active SSA position descriptions using various search criteria. An individual may search by PD...

  13. Hadronic spectral functions in nuclear matter

    Post, M.; Leupold, S.; Mosel, U.

    2004-01-01

    We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small

  14. Positive Psychology

    Peterson, Christopher

    2009-01-01

    Positive psychology is a deliberate correction to the focus of psychology on problems. Positive psychology does not deny the difficulties that people may experience but does suggest that sole attention to disorder leads to an incomplete view of the human condition. Positive psychologists concern themselves with four major topics: (1) positive…

  15. Spectral Ripple Discrimination in Normal Hearing Infants

    Horn, David L.; Won, Jong Ho; Rubinstein, Jay T.; Werner, Lynne A.

    2016-01-01

    Objectives Spectral resolution is a correlate of open-set speech understanding in post-lingually deaf adults as well as pre-lingually deaf children who use cochlear implants (CIs). In order to apply measures of spectral resolution to assess device efficacy in younger CI users, it is necessary to understand how spectral resolution develops in NH children. In this study, spectral ripple discrimination (SRD) was used to measure listeners’ sensitivity to a shift in phase of the spectral envelope of a broadband noise. Both resolution of peak to peak location (frequency resolution) and peak to trough intensity (across-channel intensity resolution) are required for SRD. Design SRD was measured as the highest ripple density (in ripples per octave) for which a listener could discriminate a 90 degree shift in phase of the sinusoidally-modulated amplitude spectrum. A 2X3 between subjects design was used to assess the effects of age (7-month-old infants versus adults) and ripple peak/trough “depth” (10, 13, and 20 dB) on SRD in normal hearing listeners (Experiment 1). In Experiment 2, SRD thresholds in the same age groups were compared using a task in which ripple starting phases were randomized across trials to obscure within-channel intensity cues. In Experiment 3, the randomized starting phase method was used to measure SRD as a function of age (3-month-old infants, 7-month-old infants, and young adults) and ripple depth (10 and 20 dB in repeated measures design). Results In Experiment 1, there was a significant interaction between age and ripple depth. The Infant SRDs were significantly poorer than the adult SRDs at 10 and 13 dB ripple depths but adult-like at 20 dB depth. This result is consistent with immature across-channel intensity resolution. In contrast, the trajectory of SRD as a function of depth was steeper for infants than adults suggesting that frequency resolution was better in infants than adults. However, in Experiment 2 infant performance was

  16. A multi-object spectral imaging instrument

    Gibson, G.M.; Dienerowitz, M.; Kelleher, P.A.; Harvey, A.R.; Padgett, M.J.

    2013-01-01

    We have developed a snapshot spectral imaging system which fits onto the side camera port of a commercial inverted microscope. The system provides spectra, in real time, from multiple points randomly selected on the microscope image. Light from the selected points in the sample is directed from the side port imaging arm using a digital micromirror device to a spectrometer arm based on a dispersing prism and CCD camera. A multi-line laser source is used to calibrate the pixel positions on the ...

  17. Spectral tunneling of lattice nonlocal solitons

    Kartashov, Yaroslav V.; Torner, Lluis; Vysloukh, Victor A.

    2010-01-01

    We address spectral tunneling of walking spatial solitons in photorefractive media with nonlocal diffusion component of the nonlinear response and an imprinted shallow optical lattice. In contrast to materials with local nonlinearities, where solitons traveling across the lattice close to the Bragg angle suffer large radiative losses, in photorefractive media with diffusion nonlinearity resulting in self-bending, solitons survive when their propagation angle approaches and even exceeds the Bragg angle. In the spatial frequency domain this effect can be considered as tunneling through the band of spatial frequencies centered around the Bragg frequency where the spatial group velocity dispersion is positive.

  18. Substitution dynamical systems spectral analysis

    Queffélec, Martine

    2010-01-01

    This volume mainly deals with the dynamics of finitely valued sequences, and more specifically, of sequences generated by substitutions and automata. Those sequences demonstrate fairly simple combinatorical and arithmetical properties and naturally appear in various domains. As the title suggests, the aim of the initial version of this book was the spectral study of the associated dynamical systems: the first chapters consisted in a detailed introduction to the mathematical notions involved, and the description of the spectral invariants followed in the closing chapters. This approach, combined with new material added to the new edition, results in a nearly self-contained book on the subject. New tools - which have also proven helpful in other contexts - had to be developed for this study. Moreover, its findings can be concretely applied, the method providing an algorithm to exhibit the spectral measures and the spectral multiplicity, as is demonstrated in several examples. Beyond this advanced analysis, many...

  19. Spectral characterization of natural backgrounds

    Winkelmann, Max

    2017-10-01

    As the distribution and use of hyperspectral sensors is constantly increasing, the exploitation of spectral features is a threat for camouflaged objects. To improve camouflage materials at first the spectral behavior of backgrounds has to be known to adjust and optimize the spectral reflectance of camouflage materials. In an international effort, the NATO CSO working group SCI-295 "Development of Methods for Measurements and Evaluation of Natural Background EO Signatures" is developing a method how this characterization of backgrounds has to be done. It is obvious that the spectral characterization of a background will be quite an effort. To compare and exchange data internationally the measurements will have to be done in a similar way. To test and further improve this method an international field trial has been performed in Storkow, Germany. In the following we present first impressions and lessons learned from this field campaign and describe the data that has been measured.

  20. Ubiquitous positioning

    Mannings, Robin

    2008-01-01

    This groundbreaking resource offers a practical, in-depth understanding of Ubiquitous Positioning - positioning systems that identify the location and position of people, vehicles and objects in time and space in the digitized networked economy. The future and growth of ubiquitous positioning will be fueled by the convergence of many other areas of technology, from mobile telematics, Internet technology, and location systems, to sensing systems, geographic information systems, and the semantic web. This first-of-its-kind volume explores ubiquitous positioning from a convergence perspective, of

  1. Adiabatic theorem and spectral concentration

    Nenciu, G.

    1981-01-01

    The spectral concentration of arbitrary order, for the Stark effect is proved to exist for a large class of Hamiltonians appearing in nonrelativistic and relativistic quantum mechanics. The results are consequences of an abstract theorem about the spectral concentration for self-ad oint operators. A general form of the adiabatic theorem of quantum mechanics, generalizing an earlier result of the author as well as some results of Lenard, is also proved [ru

  2. Interpretation of UV radiometric measurements of spectrally non-uniform sources

    Murphy, P.J.; Gardner, D.G.

    1988-01-01

    Narrow bandpass UV radiometers are used in a variety of high-temperature measurement applications. Significant systematic errors, in the form of an apparent wavelength shift in the system response curve, may be introduced when interpreting data obtained from spectrally nonuniform sources. Theoretical calculations, using transmission curves from commercially available narrow bandpass filters, show that the apparent shift in the system spectral response is a function of temperature for a blackbody source. A brief comparison between the theoretical analysis and experimentaal data is presented

  3. Ultraviolet spectral reflectance of carbonaceous materials

    Applin, Daniel M.; Izawa, Matthew R. M.; Cloutis, Edward A.; Gillis-Davis, Jeffrey J.; Pitman, Karly M.; Roush, Ted L.; Hendrix, Amanda R.; Lucey, Paul G.

    2018-06-01

    A number of planetary spacecraft missions have carried instruments with sensors covering the ultraviolet (UV) wavelength range. However, there exists a general lack of relevant UV reflectance laboratory data to compare against these planetary surface remote sensing observations in order to make confident material identifications. To address this need, we have systematically analyzed reflectance spectra of carbonaceous materials in the 200-500 nm spectral range, and found spectral-compositional-structural relationships that suggest this wavelength region could distinguish between otherwise difficult-to-identify carbon phases. In particular (and by analogy with the infrared spectral region), large changes over short wavelength intervals in the refractive indices associated with the trigonal sp2π-π* transition of carbon can lead to Fresnel peaks and Christiansen-like features in reflectance. Previous studies extending to shorter wavelengths also show that anomalous dispersion caused by the σ-σ* transition associated with both the trigonal sp2 and tetrahedral sp3 sites causes these features below λ = 200 nm. The peak wavelength positions and shapes of π-π* and σ-σ* features contain information on sp3/sp2, structure, crystallinity, and powder grain size. A brief comparison with existing observational data indicates that the carbon fraction of the surface of Mercury is likely amorphous and submicroscopic, as is that on the surface of the martian satellites Phobos and Deimos, and possibly comet 67P/Churyumov-Gerasimenko, while further coordinated observations and laboratory experiments should refine these feature assignments and compositional hypotheses. The new laboratory diffuse reflectance data reported here provide an important new resource for interpreting UV reflectance measurements from planetary surfaces throughout the solar system, and confirm that the UV can be rich in important spectral information.

  4. Positioning consumption

    Halkier, Bente; Keller, Margit

    2014-01-01

    positionings emerges based on empirical examples of research in parent–children consumption. Positionings are flexible discursive fixations of the relationship between the performances of the practitioner, other practitioners, media discourse and consumption activities. The basic positioning types...... are the practice maintenance and the practice change position, with different sorts of adapting in between. Media discourse can become a resource for a resistant position against social control or for an appropriating position in favour of space for action. Regardless of the current relation to a particular media......This article analyses the ways in which media discourses become a part of contested consumption activities. We apply a positioning perspective with practice theory to focus on how practitioners relate to media discourse as a symbolic resource in their everyday practices. A typology of performance...

  5. Observation of a hole-size-dependent energy shift of the surface-plasmon resonance in Ni antidot thin films

    Fang, H.; Akinoglu, E. M.; Fumagalli, P., E-mail: paul.fumagalli@fu-berlin.de [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Caballero, B.; García-Martín, A. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid (Spain); Papaioannou, E. Th. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany); Cuevas, J. C. [Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Giersig, M. [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Helmholtz Zentrum Berlin, Institute of Nanoarchitectures for Energy Conversion, 14195 Berlin (Germany)

    2015-04-13

    A combined experimental and theoretical study of the magneto-optic properties of a series of nickel antidot thin films is presented. The hole diameter varies from 869 down to 636 nm, while the lattice periodicity is fixed at 920 nm. This results in an overall increase of the polar Kerr rotation with decreasing hole diameter due to the increasing surface coverage with nickel. In addition, at photon energies of 2.7 and 3.3 eV, where surface-plasmon excitations are expected, we observe distinct features in the polar Kerr rotation not present in continuous nickel films. The spectral position of the peaks exhibits a red shift with decreasing hole size. This is explained within the context of an effective medium theory by a change in the effective dielectric function of the Ni thin films.

  6. Soil classification basing on the spectral characteristics of topsoil samples

    Liu, Huanjun; Zhang, Xiaokang; Zhang, Xinle

    2016-04-01

    Soil taxonomy plays an important role in soil utility and management, but China has only course soil map created based on 1980s data. New technology, e.g. spectroscopy, could simplify soil classification. The study try to classify soils basing on the spectral characteristics of topsoil samples. 148 topsoil samples of typical soils, including Black soil, Chernozem, Blown soil and Meadow soil, were collected from Songnen plain, Northeast China, and the room spectral reflectance in the visible and near infrared region (400-2500 nm) were processed with weighted moving average, resampling technique, and continuum removal. Spectral indices were extracted from soil spectral characteristics, including the second absorption positions of spectral curve, the first absorption vale's area, and slope of spectral curve at 500-600 nm and 1340-1360 nm. Then K-means clustering and decision tree were used respectively to build soil classification model. The results indicated that 1) the second absorption positions of Black soil and Chernozem were located at 610 nm and 650 nm respectively; 2) the spectral curve of the meadow is similar to its adjacent soil, which could be due to soil erosion; 3) decision tree model showed higher classification accuracy, and accuracy of Black soil, Chernozem, Blown soil and Meadow are 100%, 88%, 97%, 50% respectively, and the accuracy of Blown soil could be increased to 100% by adding one more spectral index (the first two vole's area) to the model, which showed that the model could be used for soil classification and soil map in near future.

  7. Phase extracting algorithms analysis in the white-light spectral interferometry

    Guo, Tong; Li, Bingtong; Li, Minghui; Chen, Jinping; Fu, Xing; Hu, Xiaotang

    2018-01-01

    As an optical testing method, white-light spectral interferometry has the characteristics of non-contact, high precision. The phase information can be obtained by analyzing the spectral interference signal of the tested sample, and then the absolute distance is calculated. Fourier transform method, temporal phase-shifting method, spatial phase-shifting method and envelope method can be used to extract the phase information of the spectral interference signal. In this paper, the performance of four methods to extract phase information is simulated and analyzed by using the ideal spectral interference signal. It turns out that temporal phase-shifting method has the performance of high precision, the results of Fourier transform method and envelop method are distorted at the edge of the signal, and spatial phase-shifting method has the worst precision. Adding different levels of white noise to the ideal signal, temporal phase-shifting method is most accurate, while Fourier transform method and envelope method are relatively poor. Finally, the absolute distance measurement experiment is carried out on the constructed test system, and the results are consistent with the simulation ones.

  8. Inequalities for scattering phase shifts

    Baumgartner, B.; Grosse, H.

    1985-01-01

    A recently developed method, which was used to derive bounds on energy levels, is applied to continuous spectra and gives relations between scattering phase shifts of various angular momenta. (Author)

  9. Isotope shifts in unstable nuclei

    Rebel, H.

    1980-05-01

    Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

  10. SPECTRAL FILTRATION OF IMAGES BY MEANS OF DISPERSIVE SYSTEMS

    I. M. Gulis

    2016-01-01

    Full Text Available Instruments for spectral filtration of images are an important element of the systems used in remote sensing, medical diagnostics, in-process measurements. The aim of this study is analysis of the functional features and characteristics of the proposed two image monochromator versions which are based on dispersive spectral filtering. The first is based on the use of a dispersive monochromator, where collimating and camera lenses form a telescopic system, the dispersive element of which is within the intermediate image plane. The second version is based on an imaging double monochromator with dispersion subtraction by back propagation. For the telescopic system version, the spectral and spatial resolutions are estimated, the latter being limited by aberrations and diffraction from the entrance slit. The device has been numerically simulated and prototyped. It is shown that for the spectral bandwidth 10 nm (visible spectral range, the aberration-limited spot size is from 10–20 μm at the image center to about 30 μm at the image periphery for the image size 23–27 mm. The monochromator with dispersion subtraction enables one to vary the spectral resolution (up to 1 nm and higher by changing the intermediate slit width. But the distinctive feature is a significant change in the selected central wavelength over the image field. The considered designs of dispersive image monochromators look very promising due to the particular advantages over the systems based on tunable filters as regards the spectral resolution, fast tuning, and the spectral contrast. The monochromator based on a telescopic system has a simple design and a rather large image field but it also has a limited light throughput due to small aperture size. The monochromator with dispersion subtraction has higher light throughput, can provide high spectral resolution when recording a full data cube in a series of measuring acts for different dispersive element positions

  11. The Improvement of Automated Spectral Identification Tool ASERA

    Yuan, Hailong; zhang, Yanxia

    2015-08-01

    The regular survey of Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has acquired over four millions spectra of celestial objects by the summer of 2014, covering about a third of the whole sky area. More spectra will be obtained as the survey projects (eg. LAMOST, SDSS) keeps going on. To effectively make use of the massive spectral data, various advanced data analysis methods and technologies are in great requirement. ASERA, A Spectrum Eye Recognition Assistant, provides a simple convenient solution for the user to access spectra from LAMOST and SDSS, identify their types (QSO, galaxy, and various types of stars) and estimate their redshifts in an interactive graphic interface. The toolkit is at first especially designed for quasar identification. By shifting the quasar template overlaping the target spectrum interactively, one can easily find out the best broad emission line position and the redshift value. Now, besides the quasar template, various templates for different types of galaxies (early type, later type, starburst, bulge, elliptical and luminous red galaxies) and stars (O, B, A, F, G, K, M, WD, CV, Double Stars and Emission-Line-Objects) are added. We also have developed many new useful functionalities for inspecting and analyzing spectra, such as zooming, line fitting, smoothing and automatic result saving. The target information from input catalogues and data processing result from the pipeline as well as fitting parameters for various types of templates, can be presented at the same time. Several volume processing components are developed to support the cooperation with MySQL database, internet resources and SSAP services. ASERA will be a strong helper for astronomers to recognize spectra.

  12. Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data

    Barrett, K.; Kasischke, E. S.; McGuire, A. D.; Turetsky, M. R.; Kane, E. S.

    2010-01-01

    Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface

  13. SDP_mharwit_1: Demonstration of HIFI Linear Polarization Analysis of Spectral Features

    Harwit, M.

    2010-03-01

    We propose to observe the polarization of the 621 GHz water vapor maser in VY Canis Majoris to demonstrate the capability of HIFI to make polarization observations of Far-Infrared/Submillimeter spectral lines. The proposed Demonstration Phase would: - Show that HIFI is capable of interesting linear polarization measurements of spectral lines; - Test out the highest spectral resolving power to sort out closely spaced Doppler components; - Determine whether the relative intensities predicted by Neufeld and Melnick are correct; - Record the degree and direction of linear polarization for the closely-Doppler shifted peaks.

  14. Spectral Method with the Tensor-Product Nodal Basis for the Steklov Eigenvalue Problem

    Xuqing Zhang

    2013-01-01

    Full Text Available This paper discusses spectral method with the tensor-product nodal basis at the Legendre-Gauss-Lobatto points for solving the Steklov eigenvalue problem. A priori error estimates of spectral method are discussed, and based on the work of Melenk and Wohlmuth (2001, a posterior error estimator of the residual type is given and analyzed. In addition, this paper combines the shifted-inverse iterative method and spectral method to establish an efficient scheme. Finally, numerical experiments with MATLAB program are reported.

  15. Characterizing CDOM Spectral Variability Across Diverse Regions and Spectral Ranges

    Grunert, Brice K.; Mouw, Colleen B.; Ciochetto, Audrey B.

    2018-01-01

    Satellite remote sensing of colored dissolved organic matter (CDOM) has focused on CDOM absorption (aCDOM) at a reference wavelength, as its magnitude provides insight into the underwater light field and large-scale biogeochemical processes. CDOM spectral slope, SCDOM, has been treated as a constant or semiconstant parameter in satellite retrievals of aCDOM despite significant regional and temporal variabilities. SCDOM and other optical metrics provide insights into CDOM composition, processing, food web dynamics, and carbon cycling. To date, much of this work relies on fluorescence techniques or aCDOM in spectral ranges unavailable to current and planned satellite sensors (e.g., global variability in SCDOM and fit deviations in the aCDOM spectra using the recently proposed Gaussian decomposition method. From this, we investigate if global variability in retrieved SCDOM and Gaussian components is significant and regionally distinct. We iteratively decreased the spectral range considered and analyzed the number, location, and magnitude of fitted Gaussian components to understand if a reduced spectral range impacts information obtained within a common spectral window. We compared the fitted slope from the Gaussian decomposition method to absorption-based indices that indicate CDOM composition to determine the ability of satellite-derived slope to inform the analysis and modeling of large-scale biogeochemical processes. Finally, we present implications of the observed variability for remote sensing of CDOM characteristics via SCDOM.

  16. Anisotropic shift of the irreversibility line by neutron irradiation

    Sauerzopf, F.M.; Wiesinger, H.P.; Weber, H.W.; Crabtree, G.W.; Frischherz, M.C.; Kirk, M.A.

    1991-09-01

    The irreversibility line of high-T c superconductors is shifted considerably by irradiating the material with fast neutrons. The anisotropic and non-monotonous shift is qualitatively explained by a simple model based on an interaction between three pinning mechanisms, the intrinsic pinning by the ab-planes, the weak pinning by the pre-irradiation defect structure, and strong pinning by neutron induced defect cascades. A correlation between the cascade density and the position of the irreversibility line is observed

  17. Commonwealth Edison's approach to enhanced on-shift technical capability

    Toscas, J.G.

    1981-01-01

    A long-term plan was formulated that called for the integration of accident assessment and operational supervisory functions into a new operating position called the Station Control Room Engineer (SCRE). Pending implementation of the long-term plan, an alternative to the Shift Technical Advisor concept was selected as an interim plan. This alternative, called the SRO Augmentation program, involved giving five modules of specialized training to shift Senior Operators

  18. Relativistic theory of the Lamb shift based on self energy

    Barut, A.O.; Salamin, Y.I.

    1987-07-01

    A study is made to evaluate the Lamb shift to all orders in (Zα) using relativistic Dirac Coulomb wavefunctions and without resorting to the dipole approximation. Use is made of the angular integrals and spins sums performed elsewhere exactly. A regularization procedure is given that makes the sum over the positive and negative energy states finite. Finally, the energy shift ΔE n LS is given in terms of an integral that may be done numerically. (author). 19 refs

  19. Chemical Shift Imaging (CSI) by precise object displacement

    Leclerc, Sebastien; Trausch, Gregory; Cordier, Benoit; Grandclaude, Denis; Retournard, Alain; Fraissard, Jacques; Canet, Daniel

    2006-01-01

    International audience; A mechanical device (NMR lift) has been built for displacing vertically an object (typically a NMR sample tube) inside the NMR probe with an accuracy of 1 Μm. A series of single pulse experiments are performed for incremented vertical positions of the sample. With a sufficiently spatially selective rf field, one obtains chemical shift information along the displacement direction (one dimensional Chemical Shift Imaging – CSI). Knowing the vertical radio-frequency (rf) f...

  20. The spectral induced polarisation method and its application to hydrogeological problems

    Hoerdt, A.

    2007-01-01

    The spectral induced polarisation (SIP) method is an extension of the DC resistivity technique, where an alternating current is injected and the phase shift between voltage and current is measured in addition to the amplitude. In unconsolidated sediments, the phase shift includes complementary information on the structure of the pore space, and thus it should be possible to estimate hydraulic parameters from SIP measurements. Here, I describe some recent developments and give one example where hydraulic conductivity was estimated at the field scale

  1. A classification of spectral populations observed in HF radar backscatter from the E region auroral electrojets

    S. E. Milan

    2001-02-01

    Full Text Available Observations of HF radar backscatter from the auroral electrojet E region indicate the presence of five major spectral populations, as opposed to the two predominant spectral populations, types I and II, observed in the VHF regime. The Doppler shift, spectral width, backscatter power, and flow angle dependencies of these five populations are investigated and described. Two of these populations are identified with type I and type II spectral classes, and hence, are thought to be generated by the two-stream and gradient drift instabilities, respectively. The remaining three populations occur over a range of velocities which can greatly exceed the ion acoustic speed, the usual limiting velocity in VHF radar observations of the E region. The generation of these spectral populations is discussed in terms of electron density gradients in the electrojet region and recent non-linear theories of E region irregularity generation.Key words. Ionosphere (ionospheric irregularities

  2. A classification of spectral populations observed in HF radar backscatter from the E region auroral electrojets

    S. E. Milan

    Full Text Available Observations of HF radar backscatter from the auroral electrojet E region indicate the presence of five major spectral populations, as opposed to the two predominant spectral populations, types I and II, observed in the VHF regime. The Doppler shift, spectral width, backscatter power, and flow angle dependencies of these five populations are investigated and described. Two of these populations are identified with type I and type II spectral classes, and hence, are thought to be generated by the two-stream and gradient drift instabilities, respectively. The remaining three populations occur over a range of velocities which can greatly exceed the ion acoustic speed, the usual limiting velocity in VHF radar observations of the E region. The generation of these spectral populations is discussed in terms of electron density gradients in the electrojet region and recent non-linear theories of E region irregularity generation.

    Key words. Ionosphere (ionospheric irregularities

  3. Pendulum Shifts, Context, Error, and Personal Accountability

    Harold Blackman; Oren Hester

    2011-09-01

    This paper describes a series of tools that were developed to achieve a balance in under-standing LOWs and the human component of events (including accountability) as the INL continues its shift to a learning culture where people report, are accountable and interested in making a positive difference - and want to report because information is handled correctly and the result benefits both the reporting individual and the organization. We present our model for understanding these interrelationships; the initiatives that were undertaken to improve overall performance.

  4. Effects of NMR spectral resolution on protein structure calculation.

    Suhas Tikole

    Full Text Available Adequate digital resolution and signal sensitivity are two critical factors for protein structure determinations by solution NMR spectroscopy. The prime objective for obtaining high digital resolution is to resolve peak overlap, especially in NOESY spectra with thousands of signals where the signal analysis needs to be performed on a large scale. Achieving maximum digital resolution is usually limited by the practically available measurement time. We developed a method utilizing non-uniform sampling for balancing digital resolution and signal sensitivity, and performed a large-scale analysis of the effect of the digital resolution on the accuracy of the resulting protein structures. Structure calculations were performed as a function of digital resolution for about 400 proteins with molecular sizes ranging between 5 and 33 kDa. The structural accuracy was assessed by atomic coordinate RMSD values from the reference structures of the proteins. In addition, we monitored also the number of assigned NOESY cross peaks, the average signal sensitivity, and the chemical shift spectral overlap. We show that high resolution is equally important for proteins of every molecular size. The chemical shift spectral overlap depends strongly on the corresponding spectral digital resolution. Thus, knowing the extent of overlap can be a predictor of the resulting structural accuracy. Our results show that for every molecular size a minimal digital resolution, corresponding to the natural linewidth, needs to be achieved for obtaining the highest accuracy possible for the given protein size using state-of-the-art automated NOESY assignment and structure calculation methods.

  5. Energy efficiency improvement by gear shifting optimization

    Blagojevic Ivan A.

    2013-01-01

    Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.

  6. A phenomenological view of language shift.

    Tsitsipis, Lukas D

    2004-01-01

    Sociolinguistic studies of language shift have in their majority framed their research object in a horizon of theoretically received variables such as class, ethnicity, locality, attitudes etc. In spite of a limited usefulness of such conceptual variables, and of a recently emerging focus on agency, negotiation, and praxis the best results we obtain have not questioned in a coherent and theoretically sound manner the continuing hegemony of mechanistic-metaphorical models (language death, language suicide). In this paper I propose to examine language shift as a multifaceted phenomenon, joining in this respect work by other linguistic anthropologists researching similar areas. I specifically argue that by replacing vertical concepts such as age and generation, and dichotomous logics such as center and periphery with phenomenologically inspired concepts such as typifications, consociateship, contemporariness, and stream of consciousness we are in a better position to generalize about language shift dynamics. Data for this work is derived primarily from the Albanian speech communities of modern Greece, but also from other communities for comparative purposes.

  7. Analysis of spectral methods for the homogeneous Boltzmann equation

    Filbet, Francis

    2011-04-01

    The development of accurate and fast algorithms for the Boltzmann collision integral and their analysis represent a challenging problem in scientific computing and numerical analysis. Recently, several works were devoted to the derivation of spectrally accurate schemes for the Boltzmann equation, but very few of them were concerned with the stability analysis of the method. In particular there was no result of stability except when the method was modified in order to enforce the positivity preservation, which destroys the spectral accuracy. In this paper we propose a new method to study the stability of homogeneous Boltzmann equations perturbed by smoothed balanced operators which do not preserve positivity of the distribution. This method takes advantage of the "spreading" property of the collision, together with estimates on regularity and entropy production. As an application we prove stability and convergence of spectral methods for the Boltzmann equation, when the discretization parameter is large enough (with explicit bound). © 2010 American Mathematical Society.

  8. Analysis of spectral methods for the homogeneous Boltzmann equation

    Filbet, Francis; Mouhot, Clé ment

    2011-01-01

    The development of accurate and fast algorithms for the Boltzmann collision integral and their analysis represent a challenging problem in scientific computing and numerical analysis. Recently, several works were devoted to the derivation of spectrally accurate schemes for the Boltzmann equation, but very few of them were concerned with the stability analysis of the method. In particular there was no result of stability except when the method was modified in order to enforce the positivity preservation, which destroys the spectral accuracy. In this paper we propose a new method to study the stability of homogeneous Boltzmann equations perturbed by smoothed balanced operators which do not preserve positivity of the distribution. This method takes advantage of the "spreading" property of the collision, together with estimates on regularity and entropy production. As an application we prove stability and convergence of spectral methods for the Boltzmann equation, when the discretization parameter is large enough (with explicit bound). © 2010 American Mathematical Society.

  9. Shifting schedules: the health effects of reorganizing shift work.

    Bambra, Clare L; Whitehead, Margaret M; Sowden, Amanda J; Akers, Joanne; Petticrew, Mark P

    2008-05-01

    Approximately one fifth of workers are engaged in some kind of shift work. The harmful effects of shift work on the health and work-life balance of employees are well known. A range of organizational interventions has been suggested to address these negative effects. This study undertook the systematic review (following Quality Of Reporting Of Meta [QUORUM] analyses guidelines) of experimental and quasi-experimental studies, from any country (in any language) that evaluated the effects on health and work-life balance of organizational-level interventions that redesign shift work schedules. Twenty-seven electronic databases (medical, social science, economic) were searched. Data extraction and quality appraisal were carried out by two independent reviewers. Narrative synthesis was performed. The review was conducted between October 2005 and November 2006. Twenty-six studies were found relating to a variety of organizational interventions. No one type of intervention was found to be consistently harmful to workers. However, three types were found to have beneficial effects on health and work-life balance: (1) switching from slow to fast rotation, (2) changing from backward to forward rotation, and (3) self-scheduling of shifts. Improvements were usually at little or no direct organizational cost. However, there were concerns about the generalizability of the evidence, and no studies reported on impacts on health inequalities. This review reinforces the findings of epidemiologic and laboratory-based research by suggesting that certain organizational-level interventions can improve the health of shift workers, their work-life balance, or both. This evidence could be useful when designing interventions to improve the experience of shift work.

  10. Onboard spectral imager data processor

    Otten, Leonard J.; Meigs, Andrew D.; Franklin, Abraham J.; Sears, Robert D.; Robison, Mark W.; Rafert, J. Bruce; Fronterhouse, Donald C.; Grotbeck, Ronald L.

    1999-10-01

    Previous papers have described the concept behind the MightySat II.1 program, the satellite's Fourier Transform imaging spectrometer's optical design, the design for the spectral imaging payload, and its initial qualification testing. This paper discusses the on board data processing designed to reduce the amount of downloaded data by an order of magnitude and provide a demonstration of a smart spaceborne spectral imaging sensor. Two custom components, a spectral imager interface 6U VME card that moves data at over 30 MByte/sec, and four TI C-40 processors mounted to a second 6U VME and daughter card, are used to adapt the sensor to the spacecraft and provide the necessary high speed processing. A system architecture that offers both on board real time image processing and high-speed post data collection analysis of the spectral data has been developed. In addition to the on board processing of the raw data into a usable spectral data volume, one feature extraction technique has been incorporated. This algorithm operates on the basic interferometric data. The algorithm is integrated within the data compression process to search for uploadable feature descriptions.

  11. Intersection numbers of spectral curves

    Eynard, B.

    2011-01-01

    We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined by the laplace transform of the spectral curve. This is a hint to the key role of Laplace transform in mirror symmetry. When the spectral curve is y=\\sqrt{x}, the formula gives Kontsevich--Witten intersection numbers, when the spectral curve is chosen to be the Lambert function \\exp{x}=y\\exp{-y}, the formula gives the ELSV formula for Hurwitz numbers, and when one chooses the mirror of C^3 with framing f, i.e. \\exp{-x}=\\exp{-yf}(1-\\exp{-y}), the formula gives the Marino-Vafa formula, i.e. the generating function of Gromov-Witten invariants of C^3. In some sense this formula generalizes ELSV, Marino-Vafa formula, and Mumford formula.

  12. Spectral filtering for plant production

    Young, R.E.; McMahon, M.J.; Rajapakse, N.C.; Becoteau, D.R.

    1994-12-31

    Research to date suggests that spectral filtering can be an effective alternative to chemical growth regulators for altering plant development. If properly implemented, it can be nonchemical and environmentally friendly. The aqueous CuSO{sub 4}, and CuCl{sub 2} solutions in channelled plastic panels have been shown to be effective filters, but they can be highly toxic if the solutions contact plants. Some studies suggest that spectral filtration limited to short EOD intervals can also alter plant development. Future research should be directed toward confirmation of the influence of spectral filters and exposure times on a broader range of plant species and cultivars. Efforts should also be made to identify non-noxious alternatives to aqueous copper solutions and/or to incorporate these chemicals permanently into plastic films and panels that can be used in greenhouse construction. It would also be informative to study the impacts of spectral filters on insect and microbal populations in plant growth facilities. The economic impacts of spectral filtering techniques should be assessed for each delivery methodology.

  13. Spectral dimension of quantum geometries

    Calcagni, Gianluca; Oriti, Daniele; Thürigen, Johannes

    2014-01-01

    The spectral dimension is an indicator of geometry and topology of spacetime and a tool to compare the description of quantum geometry in various approaches to quantum gravity. This is possible because it can be defined not only on smooth geometries but also on discrete (e.g., simplicial) ones. In this paper, we consider the spectral dimension of quantum states of spatial geometry defined on combinatorial complexes endowed with additional algebraic data: the kinematical quantum states of loop quantum gravity (LQG). Preliminarily, the effects of topology and discreteness of classical discrete geometries are studied in a systematic manner. We look for states reproducing the spectral dimension of a classical space in the appropriate regime. We also test the hypothesis that in LQG, as in other approaches, there is a scale dependence of the spectral dimension, which runs from the topological dimension at large scales to a smaller one at short distances. While our results do not give any strong support to this hypothesis, we can however pinpoint when the topological dimension is reproduced by LQG quantum states. Overall, by exploring the interplay of combinatorial, topological and geometrical effects, and by considering various kinds of quantum states such as coherent states and their superpositions, we find that the spectral dimension of discrete quantum geometries is more sensitive to the underlying combinatorial structures than to the details of the additional data associated with them. (paper)

  14. Spectral Imaging of Portolan Charts

    France, Fenella G.; Wilson, Meghan A.; Ghez, Anita

    2018-05-01

    Spectral imaging of Portolan Charts, early nautical charts, provided extensive new information about their construction and creation. The origins of the portolan chart style have been a continual source of perplexity to numerous generations of cartographic historians. The spectral imaging system utilized incorporates a 50 megapixel mono-chrome camera with light emitting diode (LED) illumination panels that cover the range from 365 nm to 1050 nm to capture visible and non-visible information. There is little known about how portolan charts evolved, and what influenced their creation. These early nautical charts began as working navigational tools of medieval mariners, initially made in the 1300s in Italy, Portugal and Spain; however the origin and development of the portolan chart remained shrouded in mystery. Questions about these early navigational charts included whether colorants were commensurate with the time period and geographical location, and if different, did that give insight into trade routes, or possible later additions to the charts? For example; spectral data showed the red pigment on both the 1320 portolan chart and the 1565 Galapagos Islands matched vermillion, an opaque red pigment used since antiquity. The construction of these charts was also of great interest. Spectral imaging with a range of illumination modes revealed the presence of a "hidden circle" often referred to in relation to their construction. This paper will present in-depth analysis of how spectral imaging of the Portolans revealed similarities and differences, new hidden information and shed new light on construction and composition.

  15. Towards a Perron--Frobenius Theory for Eventually Positive Operators

    Glück, Jochen

    2016-01-01

    This article is a contribution to the spectral theory of so-called eventually positive operators, i.e.\\ operators $T$ which may not be positive but whose powers $T^n$ become positive for large enough $n$. While the spectral theory of such operators is well understood in finite dimensions, the infinite dimensional case has received much less attention in the literature. We show that several sensible notions of "eventual positivity" can be defined in the infinite dimensional setting, and in con...

  16. Calculation of the density shift and broadening of the transition lines in pionic helium: Computational problems

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [Bulgarian Academy of Sciences, INRNE (Bulgaria)

    2015-08-15

    The potential energy surface and the computational codes, developed for the evaluation of the density shift and broadening of the spectral lines of laser-induced transitions from metastable states of antiprotonic helium, fail to produce convergent results in the case of pionic helium. We briefly analyze the encountered computational problems and outline possible solutions of the problems.

  17. Tapered amplifier laser with frequency-shifted feedback

    A. Bayerle, S. Tzanova, P. Vlaar, B. Pasquiou, F. Schreck

    2016-10-01

    Full Text Available We present a frequency-shifted feedback (FSF laser based on a tapered amplifier. The laser operates as a coherent broadband source with up to 370GHz spectral width and 2.3us coherence time. If the FSF laser is seeded by a continuous-wave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. The laser has an output power of 280mW and a center wavelength of 780nm. The ease and flexibility of use of tapered amplifiers makes our FSF laser attractive for a wide range of applications, especially in metrology.

  18. Absolute vibrational numbering from isotope shifts in fragmentary spectroscopic data

    Pashov, A.; Kowalczyk, P.; Jastrzebski, W.

    2018-05-01

    We discuss application of the isotope effect to establish the absolute vibrational numbering in electronic states of diatomic molecules. This is illustrated by examples of states with potential energy curves of both regular and irregular shape, with one or two potential minima. The minimum number of spectroscopic data (either term values or spectral line positions) necessary to provide a unique numbering is considered. We show that at favourable conditions just four term energies (or spectral lines) in one isotopologue and one term energy in the other suffice.

  19. Researcher positioning

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...

  20. Quasiparticles and phonon satellites in spectral functions of semiconductors and insulators: Cumulants applied to the full first-principles theory and the Fröhlich polaron

    Nery, Jean Paul; Allen, Philip B.; Antonius, Gabriel; Reining, Lucia; Miglio, Anna; Gonze, Xavier

    2018-03-01

    The electron-phonon interaction causes thermal and zero-point motion shifts of electron quasiparticle (QP) energies ɛk(T ) . Other consequences of interactions, visible in angle-resolved photoemission spectroscopy (ARPES) experiments, are broadening of QP peaks and appearance of sidebands, contained in the electron spectral function A (k ,ω ) =-ℑ m GR(k ,ω ) /π , where GR is the retarded Green's function. Electronic structure codes (e.g., using density-functional theory) are now available that compute the shifts and start to address broadening and sidebands. Here we consider MgO and LiF, and determine their nonadiabatic Migdal self-energy. The spectral function obtained from the Dyson equation makes errors in the weight and energy of the QP peak and the position and weight of the phonon-induced sidebands. Only one phonon satellite appears, with an unphysically large energy difference (larger than the highest phonon energy) with respect to the QP peak. By contrast, the spectral function from a cumulant treatment of the same self-energy is physically better, giving a quite accurate QP energy and several satellites approximately spaced by the LO phonon energy. In particular, the positions of the QP peak and first satellite agree closely with those found for the Fröhlich Hamiltonian by Mishchenko et al. [Phys. Rev. B 62, 6317 (2000), 10.1103/PhysRevB.62.6317] using diagrammatic Monte Carlo. We provide a detailed comparison between the first-principles MgO and LiF results and those of the Fröhlich Hamiltonian. Such an analysis applies widely to materials with infrared(IR)-active phonons.

  1. Does the ARFIMA really shift?

    Monache, Davide Delle; Grassi, Stefano; Santucci de Magistris, Paolo

    Short memory models contaminated by level shifts have long-memory features similar to those associated to processes generated under fractional integration. In this paper, we propose a robust testing procedure, based on an encompassing parametric specification, that allows to disentangle the level...... the highest power compared to other existing tests for spurious long-memory. Finally, we illustrate the usefulness of the proposed approach on the daily series of bipower variation and share turnover and on the monthly inflation series of G7 countries....... shift term from the ARFIMA component. The estimation is carried out via a state-space methodology and it leads to a robust estimate of the fractional integration parameter also in presence of level shifts.The Monte Carlo simulations show that this approach produces unbiased estimates of the fractional...

  2. Mass shift of charmonium states in p bar A collision

    Wolf, György; Balassa, Gábor; Kovács, Péter; Zétényi, Miklós; Lee, Su Houng

    2018-05-01

    The masses of the low lying charmonium states, namely, the J / Ψ, Ψ (3686), and Ψ (3770) are shifted downwards due to the second order Stark effect. In p bar +Au collisions at 6-10 GeV we study their in-medium propagation. The time evolution of the spectral functions of these charmonium states is studied with a Boltzmann-Uehling-Uhlenbeck (BUU) type transport model. We show that their in-medium mass shift can be observed in the dilepton spectrum. Therefore, by observing the dileptonic decay channel of these low lying charmonium states, especially for Ψ (3686), we can gain information about the magnitude of the gluon condensate in nuclear matter. This measurement could be performed at the upcoming PANDA experiment at FAIR.

  3. Examination of Spectral Transformations on Spectral Mixture Analysis

    Deng, Y.; Wu, C.

    2018-04-01

    While many spectral transformation techniques have been applied on spectral mixture analysis (SMA), few study examined their necessity and applicability. This paper focused on exploring the difference between spectrally transformed schemes and untransformed scheme to find out which transformed scheme performed better in SMA. In particular, nine spectrally transformed schemes as well as untransformed scheme were examined in two study areas. Each transformed scheme was tested 100 times using different endmember classes' spectra under the endmember model of vegetation- high albedo impervious surface area-low albedo impervious surface area-soil (V-ISAh-ISAl-S). Performance of each scheme was assessed based on mean absolute error (MAE). Statistical analysis technique, Paired-Samples T test, was applied to test the significance of mean MAEs' difference between transformed and untransformed schemes. Results demonstrated that only NSMA could exceed the untransformed scheme in all study areas. Some transformed schemes showed unstable performance since they outperformed the untransformed scheme in one area but weakened the SMA result in another region.

  4. Berlin Reflectance Spectral Library (BRSL)

    Henckel, D.; Arnold, G.; Kappel, D.; Moroz, L. V.; Markus, K.

    2017-09-01

    The Berlin Reflectance Spectral Library (BRSL) provides a collection of reflectance spectra between 0.3 and 17 µm. It was originally dedicated to support space missions to small solar system bodies. Meanwhile the library includes selections of biconical reflectance spectra for spectral data analysis of other planetary bodies as well. The library provides reference spectra of well-characterized terrestrial analogue materials and meteorites for interpretation of remote sensing reflectance spectra of planetary surfaces. We introduce the BRSL, summarize the data available, and access to use them for further relevant applications.

  5. Spectral ellipsometry of nanodiamond composite

    Yastrebov, S.G.; Ivanov-Omskij, V.I.; Gordeev, S.K.; Garriga, M.; Alonso, I.A.

    2006-01-01

    Methods of spectral ellipsometry were applied for analysis of optical properties of nanodiamond based composite in spectral region 1.4-5 eV. The nanocomposite was synthesized by molding of ultradispersed nanodiamond powder in the course of heterogeneous chemical reaction of decomposition of methane, forming pyrocarbon interconnecting nanodiamond grains. The energy of σ + π plasmon of pyrocarbon component of nanodiamond composite was restored which proves to be ∼ 24 eV; using this value, an estimation was done of pyrocarbon matrix density, which occurs to be 2 g/cm 3 [ru

  6. Paradigm Shifts in Ophthalmic Diagnostics.

    Sebag, J; Sadun, Alfredo A; Pierce, Eric A

    2016-08-01

    Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

  7. Morphisms Between Sofic Shift Spaces

    Nielsen, Jan Agentoft

    The lower entropy factor problem asks for necessary and sufficient conditions for the existence of a factor map from a (mixing) sofic shift space onto another (mixing) sofic subshift of lower entropy. The problem was posed by Mike Boyle in 1984. It remains an open problem, but the present thesis...... gives a re-formulation which can be used to effectively decide the question for a larger class of sofic shifts than all previous results. In addition, the methods are used to make progress on the corresponding embedding problem which asks for necessary and sufficient conditions for the existence...

  8. Shift-Variant Multidimensional Systems.

    1985-05-29

    x,y;u,v) is the system response at (x,y) to an unit impulse applied at (u,v). The presence of additive noise in the preceding input-output model of a...space model developed works very effi- ciently to deblur images affected by 2-D linear shift- varying blurs, its use, in presence of noise needs to be...causal linear shift-variant (LSV) system, whose impulse res- ponse is a K-th order degenerate sequence, a K-th order state-space model was obtained

  9. Explaining (Missing) Regulator Paradigm Shifts

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    The global financial and economic crisis has prompted some scholars to suggest that a fundamental regulatory shift away from neoliberalism will take place – both in general and in the field of EU competition regulation. This paper shows that so far no radical break with the neoliberal type...... regulation after the crisis in the 1970s, the paper argues that the preconditions for a fundamental shift in this issue area are not present this time around. Several reasons account for this: the current crisis has been construed by economic and political elites as a crisis within and not of neoliberal...

  10. Radiographic positioning

    Eisenberg, R.L.; Dennis, C.A.; May, C.

    1989-01-01

    This book concentrates on the routine radiographic examinations commonly performed. It details the wide variety of examinations possible and their place in initial learning and in the radiology department as references for those occasions when an unusual examination is requested. This book provides information ranging from basic terminology to skeletal positioning to special procedures. Positions are discussed and supplemented with a picture of a patient, the resulting radiograph, and a labeled diagram. Immobilization and proper shielding of the patient are also shown

  11. Position encoder

    Goursky, Vsevolod

    1975-01-01

    A circuitry for deriving the quotient of signal delivered by position-sensitive detectors is described. Digital output is obtained in the form of 10- to 12-bit words. Impact position may be determined with 0.25% accuracy when the dynamic range of the energy signal is less 1:10, and 0.5% accuracy when the dynamic range is 1:20. The division requires an average time of 5μs for 10-bit words

  12. Position encoder

    Goursky, V.

    1975-05-01

    This paper describes circuitry for deriving the quotient of signals delivered by position-sensitive detectors. Digital output is obtained in the form of 10 to 12 bit words. Impact position may be determined with 0.25% accuracy when the dynamic range of the energy signal is less than 1:10, and 0.5% accuracy when the dynamic range is 1:20. The division requires an average time of 5μs for 10-bit words [fr

  13. The Underlying Social Dynamics of Paradigm Shifts.

    Rodriguez-Sickert, Carlos; Cosmelli, Diego; Claro, Francisco; Fuentes, Miguel Angel

    2015-01-01

    We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution) within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i) marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm); and ii) radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology) that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  14. The Underlying Social Dynamics of Paradigm Shifts.

    Carlos Rodriguez-Sickert

    Full Text Available We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm; and ii radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  15. Electrostatic Origin of the Red Solvatochromic Shift of DFHBDI in RNA Spinach.

    Bose, Samik; Chakrabarty, Suman; Ghosh, Debashree

    2017-05-11

    Interactions with the environment tune the spectral properties of biological chromophores, e.g., fluorescent proteins. Understanding the relative contribution of the various types of noncovalent interactions in the spectral shifts can provide rational design principles toward developing new fluorescent probes. In this work, we investigate the origin of the red shift in the absorption spectra of the difluoro hydroxybenzylidene dimethyl imidazolinone (DFHBDI) chromophore in RNA spinach as compared to the aqueous solution. We systematically decompose the effects of various components of interactions, namely, stacking, hydrogen bonding, and long-range electrostatics, in order to elucidate the relative role of these interactions in the observed spectral behavior. We find that the absorption peak of DFHBDI is red-shifted by ∼0.35 eV in RNA relative to the aqueous solution. Earlier proposals from Huang and co-workers have implicated the stacking interactions between DFHBDI and nucleic acid bases to be the driving force behind the observed red shift. In contrast, our findings reveal that the long-range electrostatic interactions between DFHBDI and negatively charged RNA make the most significant contribution. Moreover, we notice that the opposing electrostatic fields due to the RNA backbone and the polarized water molecules around the RNA give rise to the resultant red shift. Our results emphasize the effect of strong heterogeneity in the various environmental factors that might be competing with each other.

  16. Spectral conversion for thin film solar cells and luminescent solar concentrators

    Sark, van W.G.J.H.M.; Wild, de J.; Krumer, Z.; Mello Donegá, de C.; Schropp, R.E.I.; Nozik, A.J.; Beard, M.C.; Conibeer, G.

    2014-01-01

    Full spectrum absorption combined with effective generation and collection of charge carriers is a prerequisite for attaining high efficiency solar cells. Two examples of spectral conversion are treated in this chapter, i.e., up-conversion and down-shifting. Up-conversion is applied to thin film

  17. Observed spectral features of dust

    Willner, S.P.

    1984-01-01

    The author concentrates on the observed properties of dust spectral features. Identifications, based on laboratory data, are given whenever plausible ones exist. There are a very large number of papers in the literature of even such a young field as infrared spectroscopy, and therefore the author refers only to the most recent paper on a topic or to another review. (Auth.)

  18. Rayleigh imaging in spectral mammography

    Berggren, Karl; Danielsson, Mats; Fredenberg, Erik

    2016-03-01

    Spectral imaging is the acquisition of multiple images of an object at different energy spectra. In mammography, dual-energy imaging (spectral imaging with two energy levels) has been investigated for several applications, in particular material decomposition, which allows for quantitative analysis of breast composition and quantitative contrast-enhanced imaging. Material decomposition with dual-energy imaging is based on the assumption that there are two dominant photon interaction effects that determine linear attenuation: the photoelectric effect and Compton scattering. This assumption limits the number of basis materials, i.e. the number of materials that are possible to differentiate between, to two. However, Rayleigh scattering may account for more than 10% of the linear attenuation in the mammography energy range. In this work, we show that a modified version of a scanning multi-slit spectral photon-counting mammography system is able to acquire three images at different spectra and can be used for triple-energy imaging. We further show that triple-energy imaging in combination with the efficient scatter rejection of the system enables measurement of Rayleigh scattering, which adds an additional energy dependency to the linear attenuation and enables material decomposition with three basis materials. Three available basis materials have the potential to improve virtually all applications of spectral imaging.

  19. Speech recognition from spectral dynamics

    Some of the history of gradual infusion of the modulation spectrum concept into Automatic recognition of speech (ASR) comes next, pointing to the relationship of modulation spectrum processing to wellaccepted ASR techniques such as dynamic speech features or RelAtive SpecTrAl (RASTA) filtering. Next, the frequency ...

  20. Spectral ansatz in quantum electrodynamics

    Atkinson, D.; Slim, H.A.

    1979-01-01

    An ansatz of Delbourgo and Salam for the spectral representation of the vertex function in quantum electrodynamics. The Ward-Takahashi identity is respected, and the electron propagator does not have a ghost. The infra-red and ultraviolet behaviours of the electron propagator in this theory are considered, and a rigorous existence theorem for the propagator in the Yennie gauge is presented

  1. Spectral Diagonal Ensemble Kalman Filters

    Kasanický, Ivan; Mandel, Jan; Vejmelka, Martin

    2015-01-01

    Roč. 22, č. 4 (2015), s. 485-497 ISSN 1023-5809 R&D Projects: GA ČR GA13-34856S Grant - others:NSF(US) DMS-1216481 Institutional support: RVO:67985807 Keywords : data assimilation * ensemble Kalman filter * spectral representation Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.321, year: 2015

  2. Biomarkers and Biological Spectral Imaging

    2001-01-23

    G. Sowa, H. H. Mantsch, National Research Council Canada; S. L. Zhang, Unilever Research (USA) 85 Brain tissue charcterization using spectral imaging...image registration and of the expert staff of Hill Top Research in Winnipeg for hosting the hydration study. Financial assistance from Unilever Research

  3. Leadership Shifts in Changing Field

    Zubrzycki, Jaclyn

    2013-01-01

    As groups representing local and state education players struggle to remain relevant in a policy conversation often dominated by foundations, think tanks, new advocacy groups, and political and business figures, a shift in leadership has been under way at major associations. Most of the changes have come as part of the natural churn; former…

  4. Crichton's phase-shift ambiguity

    Atkinson, D.; Johnson, P.W.; Mehta, N.; Roo, M. de

    1973-01-01

    A re-examination of the SPD phase-shift ambiguity is made with a view to understanding certain singular features of the elastic unitarity constraint. An explicit solution of Crichton's equations is presented, and certain features of this solution are displayed graphically. In particular, it is shown

  5. Environmental Protection: a shifting focus

    Dr. ir. Jan Venselaar

    2004-01-01

    The last two decades have seen a fundamental change in the way chemistry handles environmental issues. A shift in focus has occurred from 'end-of-pipe' to prevention and process integration. Presently an even more fundamental change is brought about by the need for sustainable development. It is

  6. Anthropometric changes and fluid shifts

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  7. Spectral decomposition of MR spectroscopy signatures with use of eigenanalysis

    Hearshen, D.O.; Windham, J.P.; Roebuck, J.R.; Helpern, J.A.

    1989-01-01

    Partial-volume contamination and overlapping resonances are common problems in whole-body MR spectroscopy and can affect absolute or relative intensity and chemical-shift measurements. One technique, based on solution of constrained eigenvalue problems, treats spectra as N-dimensional signatures and minimizes contributions of undesired signatures while maximizing contributions of desired signatures in compromised spectra. Computer simulations and both high-resolution (400-MHz) and whole-body (63.8-MHz) phantom studies tested accuracy and reproducibility of spectral decomposition. Results demonstrated excellent decomposition and good reproducibility within certain constraints. The authors conclude that eigenanalysis may improve quantitation of spectra without introducing operator bias

  8. Positional games

    Hefetz, Dan; Stojaković, Miloš; Szabó, Tibor

    2014-01-01

    This text serves as a thorough introduction to the rapidly developing field of positional games. This area constitutes an important branch of combinatorics, whose aim it is to systematically develop an extensive mathematical basis for a variety of two-player perfect information games. These range from such popular games as Tic-Tac-Toe and Hex to purely abstract games played on graphs and hypergraphs. The subject of positional games is strongly related to several other branches of combinatorics such as Ramsey theory, extremal graph and set theory, and the probabilistic method. These notes cover a variety of topics in positional games, including both classical results and recent important developments. They are presented in an accessible way and are accompanied by exercises of varying difficulty, helping the reader to better understand the theory. The text will benefit both researchers and graduate students in combinatorics and adjacent fields.

  9. Spectral shifts and structures of phenol center dot center dot center dot Ar-n clusters

    Armentano, A.; Černý, Jiří; Riese, M.; Taherkhani, M.; Ben Yezzar, M.; Muller-Dethlefs, K.

    2011-01-01

    Roč. 13, č. 13 (2011), s. 6077-6084 ISSN 1463-9076 Institutional research plan: CEZ:AV0Z50520701 Keywords : VAN-DER-WAALS * BENZENE-ARGON CLUSTERS * INFRARED-SPECTRA Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.573, year: 2011

  10. Spectral shifting strongly constrains molecular cloud disruption by radiation pressure on dust

    Reissl, Stefan; Klessen, Ralf S.; Mac Low, Mordecai-Mark; Pellegrini, Eric W.

    2018-03-01

    Aim. We aim to test the hypothesis that radiation pressure from young star clusters acting on dust is the dominant feedback agent disrupting the largest star-forming molecular clouds and thus regulating the star-formation process. Methods: We performed multi-frequency, 3D, radiative transfer calculations including both scattering and absorption and re-emission to longer wavelengths for model clouds with masses of 104-107 M⊙, containing embedded clusters with star formation efficiencies of 0.009-91%, and varying maximum grain sizes up to 200 μm. We calculated the ratio between radiative and gravitational forces to determine whether radiation pressure can disrupt clouds. Results: We find that radiation pressure acting on dust almost never disrupts star-forming clouds. Ultraviolet and optical photons from young stars to which the cloud is optically thick do not scatter much. Instead, they quickly get absorbed and re-emitted by the dust at thermal wavelengths. As the cloud is typically optically thin to far-infrared radiation, it promptly escapes, depositing little momentum in the cloud. The resulting spectrum is more narrowly peaked than the corresponding Planck function, and exhibits an extended tail at longer wavelengths. As the opacity drops significantly across the sub-mm and mm wavelength regime, the resulting radiative force is even smaller than for the corresponding single-temperature blackbody. We find that the force from radiation pressure falls below the strength of gravitational attraction by an order of magnitude or more for either Milky Way or moderate starbust conditions. Only for unrealistically large maximum grain sizes, and star formation efficiencies far exceeding 50% do we find that the strength of radiation pressure can exceed gravity. Conclusions: We conclude that radiation pressure acting on dust does not disrupt star-forming molecular clouds in any Local Group galaxies. Radiation pressure thus appears unlikely to regulate the star-formation process on either local or global scales.

  11. Spectral shift controlled reactor, UO2 once-through cycle optimized

    1978-05-01

    This paper presents technical and economic data on the SSCR which may be of use in the International Fuel Cycle Evaluation Program to intercompare alternative nuclear systems. Included in this data is information on the optimized UO 2 once-through fuel cycle. The ''optimized'' cycle refers to a UO 2 once-through cycle which has better fuel resource utilization than the conventional UO 2 cycle employed in current design PWRs. This fuel cycle uses more in-core batches and a higher discharge exposure than current PWR fuel management schemes. The proposed cycle is not optimal in a mathematical sense, however, since additional resource savings can be obtained if the discharge exposure is extended to even higher values and the number of in-core fuel batches is increased further. The present cycle was selected as ''optimal'' based on the assumption that it can be achieved with only an extension of fuel design technology and can therefore be deployed in a relatively short time frame. In the longer term, modification to reactor geometry as well as further extensions of discharge burnup might be considered to realize additional reduction in uranium resource requirements. The data contained in this paper has been developed by an ongoing program which at the present time is only 50% complete. The data presented here should therefore be considered preliminary and will be updated in the future as required

  12. Asymmetry and the shift of the Compton profile

    Chatterjee, B.K.; Roy, S.C.; Suric, T.; LaJohn, L.A.; Pratt, R.H.

    2007-01-01

    We show that the conventionally defined asymmetry of the Compton profile (CP) is, to a large extent, simply a shift of CP. Compton scattering is widely used in studying the electron momentum distribution (EMD) of complex systems. Extraction of information about the EMD is based on an impulse approximation (IA) description of the process. In IA the scattering from bound electrons is described as scattering from the EMD of free electrons. Most often the angular and energy distributions of scattered photons (doubly differential cross sections (DDCS)) is measured and presented in terms of CP, which is just the DDCS normalized by a kinematical factor. The deviations of measured CP from the IA results are conventionally described as an asymmetry of CP about the IA peak position. IA predicts CP to be symmetric. We have examined the discrepancy between IA predictions (and the corresponding relativistic version of IA, RIA) and more rigorous approaches (A 2 and S-matrix), using independent particle approximations for the description of the bound state of electrons. In the nonrelativistic region (in which many measurements of CP are performed) we find that the conventional asymmetry can largely be understood as the shift of the peak position. The true asymmetry with respect to the shifted peak position is in fact much smaller. RIA has similar properties to IA, except that for atoms with high nuclear charge the p → .A → interaction may modify the shift and limit the utility of description as a shift

  13. Updated Status and Performance at the Fourth HST COS FUV Lifetime Position

    Taylor, Joanna M.; De Rosa, Gisella; Fix, Mees B.; Fox, Andrew; Indriolo, Nick; James, Bethan; Jedrzejewski, Robert I.; Oliveira, Cristina M.; Penton, Steven V.; Plesha, Rachel; Proffitt, Charles R.; Rafelski, Marc; Roman-Duval, Julia; Sahnow, David J.; Snyder, Elaine M.; Sonnentrucker, Paule; White, James

    2017-06-01

    To mitigate the adverse effects of gain sag on the spectral quality and accuracy of Hubble Space Telescope’s Cosmic Origins Spectrograph FUV observations, COS FUV spectra will be moved from Lifetime Position 3 (LP3) to a new pristine location on the detectors at LP4 in July 2017. To achieve maximal spectral resolution while preserving detector area, the spectra will be shifted in the cross-dispersion (XD) direction by -2.5" (about -31 pixels) from LP3 or -5” (about 62 pixels) from the original LP1. At LP4, the wavelength calibration lamp spectrum can overlap with the previously gain-sagged LP2 PSA spectrum location. If lamp lines fall in the gain sag holes from LP2, it can cause line ratios to change and the wavelength calibration to fail. As a result, we have updated the Wavecal Parameters Reference Table and CalCOS to address this issue. Additionally, it was necessary to extend the current geometric correction in order to encompass the entire LP4 location. Here we present 2-D template profiles and 1-D spectral trace centroids derived at LP4 as well as LP4-related updates to the wavelength calibration, and geometric correction.

  14. On the energy shift the ECC cusp. Does the shift really exist?

    Sarkadi, L.; Barrachina, R.O.

    2004-01-01

    The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions are generally thought to be a divergence. Recently Shah et al., however, claimed that 'the ECC cusp is indeed a cusp, and not a divergence smoothed by the experiment'. These authors measured the ECC cusp for collisions of 10- and 20-keV protons with H 2 and He, and found that the peak was shifted to lower velocity than its expected position. We also carried out CTMC calculations (for the case of 20-keV protons on He) by which we demonstrated that the shift really exists but its value depends on the angular window of the electron detection. (K.A.)

  15. Researcher Positioning

    Khawaja, Iram; Mørck, Line Lerche

    2009-01-01

    involvement by the researcher, which challenges traditional perspectives onresearch and researcher positioning. A key point in this regard is the importance ofconstant awareness of and reflection on the multiple ways in which one's positioningas a researcher influences the research process. Studying the other...

  16. Position detector

    Hayakawa, Toshifumi.

    1985-01-01

    Purpose: To enable to detect the position of an moving object in a control rod position detector, stably in a digital manner at a high accuracy and free from the undesired effects of circumstantial conditions such as the reactor temperature. Constitution: Coils connected in parallel with each other are disposed along the passage of a moving object and variable resistors and relays are connected in series with each of the coils respectively. Light emitting diodes is connected in series with the contacts of the respective relays. The resistance value of the variable resistors are adjusted depending on the changes in the circumstantial conditions and temperature distribution upon carrying out the positional detection. When the object is inserted into a coils, the relevant relay is deenergized, by which the relay contacts are closed to light up the diode. In the same manner, as the object is successively inserted into the coils, the diodes are lighted-up successively thereby enabling highly accurate and stable positional detection in a digital manner, free from the undesired effects of the circumstantial conditions. (Horiuchi, T.)

  17. Accuracy in mineral identification: image spectral and spatial resolutions and mineral spectral properties

    L. Pompilio

    2006-06-01

    Full Text Available Problems related to airborne hyperspectral image data are reviewed and the requirements for data analysis applied to mineralogical (rocks and soils interpretation are discussed. The variability of mineral spectral features, including absorption position, shape and depth is considered and interpreted as due to chemical composition, grain size effects and mineral association. It is also shown how this variability can be related to well defined geologic processes. The influence of sensor noise and diffuse atmospheric radiance in classification accuracy is also analyzed.

  18. The perceptual enhancement of tones by frequency shifts.

    Demany, Laurent; Carcagno, Samuele; Semal, Catherine

    2013-04-01

    In a chord of pure tones with a flat spectral profile, one tone can be perceptually enhanced relative to the other tones by the previous presentation of a slightly different chord. "Intensity enhancement" (IE) is obtained when the component tones of the two chords have the same frequencies, but in the first chord the target of enhancement is attenuated relative to the other tones. "Frequency enhancement" (FE) is obtained when both chords have a flat spectral profile, but the target of enhancement shifts in frequency from the first to the second chord. We report here an experiment in which IE and FE were measured using a task requiring the listener to indicate whether or not the second chord included a tone identical to a subsequent probe tone. The results showed that a global attenuation of the first chord relative to the second chord disrupted IE more than FE. This suggests that the mechanisms of IE and FE are not the same. In accordance with this suggestion, computations of the auditory excitation patterns produced by the chords indicate that the mechanism of IE is not sufficient to explain FE for small frequency shifts. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Insights on the Spectral Signatures of Stellar Activity and Planets from PCA

    Davis, Allen B.; Fischer, Debra A. [Department of Astronomy, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511 (United States); Cisewski, Jessi [Department of Statistics, Yale University, 24 Hillhouse Avenue, New Haven, CT 06511 (United States); Dumusque, Xavier [Observatoire de Genève, Université de Genève, 51 ch. des Maillettes, 1290 Versoix (Switzerland); Ford, Eric B., E-mail: allen.b.davis@yale.edu [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States)

    2017-09-01

    Photospheric velocities and stellar activity features such as spots and faculae produce measurable radial velocity signals that currently obscure the detection of sub-meter-per-second planetary signals. However, photospheric velocities are imprinted differently in a high-resolution spectrum than are Keplerian Doppler shifts. Photospheric activity produces subtle differences in the shapes of absorption lines due to differences in how temperature or pressure affects the atomic transitions. In contrast, Keplerian Doppler shifts affect every spectral line in the same way. With a high enough signal-to-noise (S/N) and resolution, statistical techniques can exploit differences in spectra to disentangle the photospheric velocities and detect lower-amplitude exoplanet signals. We use simulated disk-integrated time-series spectra and principal component analysis (PCA) to show that photospheric signals introduce spectral line variability that is distinct from that of Doppler shifts. We quantify the impact of instrumental resolution and S/N for this work.

  20. [Burden and health effects of shift work].

    Heitmann, Jörg

    2010-10-01

    In Germany aprox. 15% of all employees have irregular or flexible working hours. Disturbed sleep and/or hypersomnia are direct consequences of shift work and therefore described as shift work disorder. Beyond this, shift work can also be associated with specific pathological disorders. There are individual differences in tolerance to shift work. Optimization of both shift schedules and sleep to "non-physiological" times of the day are measures to counteract the negative effects of shift work. There is still not enough evidence to recommend drugs for routine use in shift workers. © Georg Thieme Verlag Stuttgart · New York.

  1. ON THE ANTI-CORRELATION BETWEEN SPECTRAL LINE BROADENING AND INTENSITY IN CORONAL STRUCTURES OBSERVED WITH EIS

    Scott, J. T.; Martens, P. C. H.

    2011-01-01

    The advance in spectral resolution of the Extreme Ultraviolet Imaging (EIS) spectrometer on board Hinode has allowed for more detailed analysis of coronal spectral lines. Large line broadening and blueshifted velocities have been found in the periphery of active region (AR) cores and near the footpoints of coronal loops. This line broadening is yet to be understood. We study the correlation of intensity and line width for entire ARs and sub-regions selected to include coronal features. The results show that although a slight positive correlation can be found when considering whole images, many sub-regions have a negative correlation between intensity and line width. Sections of a coronal loop display some of the largest anti-correlations found for this study with the increased line broadening occurring directly adjacent to the footpoint section of the loop structure, not at the footpoint itself. The broadened lines may be due to a second Doppler-shifted component that is separate from the main emitting feature such as a coronal loop, but related in their excitation. The small size of these features forces the considerations of investigator and instrumental effects. Preliminary analyses are shown that indicate the possibility of a point-spread function that is not azimuthally symmetric and may affect velocity and line profile measurements.

  2. Relationship of night and shift work with weight change and lifestyle behaviors.

    Bekkers, Marga B M; Koppes, Lando L J; Rodenburg, Wendy; van Steeg, Harry; Proper, Karin I

    2015-04-01

    To prospectively study the association of night and shift work with weight change and lifestyle behaviors. Workers participating in the Netherlands Working Conditions Cohort Study (2008 and 2009) (N = 5951) reported night and shift work, weight and height. Groups included stable night or shift work, from day work to night or shift work, from night or shift work to day work, and no night or shift work in 2008 and 2009. Regression analyses were used to study association changes in night and shift work with weight change and changes in lifestyle behaviors. A larger weight change was seen in normal-weight workers changing from day to shift work (β = 0.93%; 95% confidence interval, 0.01 to 1.85) compared with stable no shift workers. No further associations of night and shift work with weight change were observed, neither in normal-weight, overweight, and obese workers. Despite the fact that starting night or shift work is associated with some unhealthy lifestyle habits, this study did not confirm a positive association of night and shift work with weight change over 1 year, except for normal-weight workers moving from day to shift work.

  3. Special training of shift personnel

    Martin, H.D.

    1981-01-01

    The first step of on-the-job training is practical observation phase in an operating Nuclear Plant, where the participants are assigned to shift work. The simulator training for operating personnel, for key personnel and, to some extent, also for maintenance personnel and specialists give the practical feeling for Nuclear Power Plant behaviour during normal and abnormal conditions. During the commissioning phase of the own Nuclear Power Plant, which is the most important practical training, the participants are integrated into the commissioning staff and assisted during their process of practical learning by special instructors. The preparation for the licensing exams is vitally important for shift personnel and special courses are provided after the first non-nuclear trial operation of the plant. Personnel training also includes performance of programmes and material for retraining, training of instructors and assistance in building up special training programmes and material as well as training centers. (orig./RW)

  4. Shift work as an oxidative stressor

    Pasalar Parvin; Farahani Saeed; Sharifian Akbar; Gharavi Marjan; Aminian Omid

    2005-01-01

    Abstract Background Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. Methods Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worke...

  5. A multi-object spectral imaging instrument

    Gibson, G M; Dienerowitz, M; Kelleher, P A; Harvey, A R; Padgett, M J

    2013-01-01

    We have developed a snapshot spectral imaging system which fits onto the side camera port of a commercial inverted microscope. The system provides spectra, in real time, from multiple points randomly selected on the microscope image. Light from the selected points in the sample is directed from the side port imaging arm using a digital micromirror device to a spectrometer arm based on a dispersing prism and CCD camera. A multi-line laser source is used to calibrate the pixel positions on the CCD for wavelength. A CMOS camera on the front port of the microscope allows the full image of the sample to be displayed and can also be used for particle tracking, providing spectra of multiple particles moving in the sample. We demonstrate the system by recording the spectra of multiple fluorescent beads in aqueous solution and from multiple points along a microscope sample channel containing a mixture of red and blue dye. (paper)

  6. CONTRAST ENHANCED SPECTRAL MAMMOGRAPHY (CESM (REVIEW

    N. I. Rozhkova

    2015-01-01

    Full Text Available The problem of early diagnosis of a breast cancer is extremely actual. Growth of incidence at women from 19 to 39 years increased for 34% over the last 10 years. It defines need of acceleration of development and deployment of the latest technologies of identification of the earliest symptoms of diseases. The x-ray mammography is the conducting method among of all radiological methods of diagnostics. Nevertheless a number of restrictions of method reduces its efficiency. The technologies increasing informational content of x-ray mammography – the leading method of screening – due to use of artificial contrasting and advantages of digital technologies are constantly developed. In this review it is described works, in which the authors having clinical experience of application of CESM – contrastenhanced spectral mammography on representative group of women. Positive sides and restrictions of new technology in comparison with mammography, ultrasonography and MRT are shown in this article.

  7. Shift schedule, work-family relationships, marital communication, job satisfaction and health among transport service shift workers.

    Iskra-Golec, Irena; Smith, Lawrence; Wilczek-Rużyczka, Ewa; Siemiginowska, Patrycja; Wątroba, Joanna

    2017-02-21

    Existing research has documented that shiftwork consequences may depend on the shift system parameters. Fast rotating systems (1-3 shifts of the same kind in a row) and day work have been found to be less disruptive biologically and socially than slower rotating systems and afternoon and night work. The aim of this study was to compare day workers and shift workers of different systems in terms of rotation speed and shifts worked with regard to work-family and family-work positive and negative spillover, marital communication style, job satisfaction and health. Employees (N = 168) of the maintenance workshops of transportation service working different shift systems (day shift, weekly rotating 2 and 3‑shift system, and fast rotating 3-shift system) participated in the study. They completed the Work- Family Spillover Questionnaire, Marital Communication Questionnaire, Minnesota Job Satisfaction Questionnaire and the Physical Health Questionnaire (a part of the Standard Shiftwork Index). The workers of quicker rotating 3-shift systems reported significantly higher scores of family-to-work facilitation (F(3, 165) = 4.175, p = 0.007) and a higher level of constructive style of marital communication (Engagement F(3, 165) = 2.761, p = 0.044) than the workers of slower rotating 2-shift systems. There were no differences between the groups of workers with regard to health and job satisfaction. A higher level of work-family facilitation and a more constructive style of marital communication were found among the workers of faster rotating 3-shift system when compared to the workers of a slower rotating 2-shift system (afternoon, night). This may indicate that the fast rotating shift system in contrary to the slower rotating one is more friendly for the work and family domains and for the relationship between them. Int J Occup Med Environ Health 2017;30(1):121-131. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  8. Maintaining positive

    Gheorghe Gh. IONESCU; Adina Letitia NEGRUSA

    2004-01-01

    Maintaining positive work-force relationships includes in effective labor-management relations and making appropriate responses to current employee issues. Among the major current employee issues are protection from arbitrary dismissal, drug and alcohol abuse, privacy rights and family maters and they impact work. In our paper we discus two problems: first, the meanings of industrial democracy; second, the three principal operational concepts of industrial democracy (1) industrial democracy t...

  9. Perihelium shifts in central potentials

    Amorim, A.E.A.; Ferreira, P.L.

    1987-01-01

    Motivated by the rigorous results on level ordering for arbitrary central potentials recently derived in the literature a classical treatment of the perihelium shifts is presented, based on the consideration of those orbits which lie in the vicinity of a circular orbit. The role played by the Laplacian of the potential is emphasized. By the same approach Bertrand's theorem is also discussed, in connection with Arnold's proof. (Author) [pt

  10. Multicolor Holography With Phase Shifting

    Vikram, Chandra S.

    1996-01-01

    Prototype apparatus constructed to test feasibility of two-color holographic interferometric scheme in which data for reconstructing holographic wavefront obtained with help of phase-shifting technique. Provides two sets of data needed to solve equations for effects of temperature and concentration. Concept extended to holography at three or more wavelengths to measure three or more phenomena associated with significant variations in index of refraction

  11. Spectral synchronicity in brain signals

    de Jesus Euan Campos, Carolina; Ombao, Hernando; Ortega, Joaquí n

    2018-01-01

    This paper addresses the problem of identifying brain regions with similar oscillatory patterns detected from electroencephalograms. We introduce the hierarchical spectral merger (HSM) clustering method where the feature of interest is the spectral curve and the similarity metric used is the total variance distance. The HSM method is compared with clustering using features derived from independent-component analysis. Moreover, the HSM method is applied to 2 different electroencephalogram datasets. The first was recorded at resting state where the participant was not engaged in any cognitive task; the second was recorded during a spontaneous epileptic seizure. The results of the analyses using the HSM method demonstrate that clustering could evolve over the duration of the resting state and during epileptic seizure.

  12. Spectral synchronicity in brain signals

    de Jesus Euan Campos, Carolina

    2018-05-04

    This paper addresses the problem of identifying brain regions with similar oscillatory patterns detected from electroencephalograms. We introduce the hierarchical spectral merger (HSM) clustering method where the feature of interest is the spectral curve and the similarity metric used is the total variance distance. The HSM method is compared with clustering using features derived from independent-component analysis. Moreover, the HSM method is applied to 2 different electroencephalogram datasets. The first was recorded at resting state where the participant was not engaged in any cognitive task; the second was recorded during a spontaneous epileptic seizure. The results of the analyses using the HSM method demonstrate that clustering could evolve over the duration of the resting state and during epileptic seizure.

  13. Spectral computations for bounded operators

    Ahues, Mario; Limaye, Balmohan

    2001-01-01

    Exact eigenvalues, eigenvectors, and principal vectors of operators with infinite dimensional ranges can rarely be found. Therefore, one must approximate such operators by finite rank operators, then solve the original eigenvalue problem approximately. Serving as both an outstanding text for graduate students and as a source of current results for research scientists, Spectral Computations for Bounded Operators addresses the issue of solving eigenvalue problems for operators on infinite dimensional spaces. From a review of classical spectral theory through concrete approximation techniques to finite dimensional situations that can be implemented on a computer, this volume illustrates the marriage of pure and applied mathematics. It contains a variety of recent developments, including a new type of approximation that encompasses a variety of approximation methods but is simple to verify in practice. It also suggests a new stopping criterion for the QR Method and outlines advances in both the iterative refineme...

  14. Shift Work and Endocrine Disorders

    M. A. Ulhôa

    2015-01-01

    Full Text Available The objective of this review was to investigate the impact of shift and night work on metabolic processes and the role of alterations in the sleep-wake cycle and feeding times and environmental changes in the occurrence of metabolic disorders. The literature review was performed by searching three electronic databases for relevant studies published in the last 10 years. The methodological quality of each study was assessed, and best-evidence synthesis was applied to draw conclusions. The literature has shown changes in concentrations of melatonin, cortisol, ghrelin, and leptin among shift workers. Melatonin has been implicated for its role in the synthesis and action of insulin. The action of this hormone also regulates the expression of transporter glucose type 4 or triggers phosphorylation of the insulin receptor. Therefore, a reduction in melatonin can be associated with an increase in insulin resistance and a propensity for the development of diabetes. Moreover, shift work can negatively affect sleep and contribute to sedentarism, unhealthy eating habits, and stress. Recent studies on metabolic processes have increasingly revealed their complexity. Physiological changes induced in workers who invert their activity-rest cycle to fulfill work hours include disruptions in metabolic processes.

  15. Shift in genomic RNA patterns of human rotaviruses isolated from ...

    Rotalvirus-positive specimens from 322 infants and young children submitted to private patl1ology laboratories were analysed by polyacrylamide-gel electrophoresis of the viral RNA. A predominance of long RNA profiles occurred and a temporal shift in the genomic patterns was identified. An epidemic of the classic shorter ...

  16. Modal planes are spectral triples

    Gayral, Victor; Iochum, Bruno; Schuecker, Thomas; Gracia-Bondia, Jose M.; Varilly, Joseph C.

    2003-09-01

    Axioms for nonunital spectral triples, extending those introduced in the unital case by Connes, are proposed. As a guide, and for the sake of their importance in noncommutative quantum field theory, the spaces R 2N endowed with Moyal products are intensively investigated. Some physical applications, such as the construction of noncommutative Wick monomials and the computation of the Connes-Lott functional action, are given for these noncommutative hyperplanes. (author)

  17. Chebyshev and Fourier spectral methods

    Boyd, John P

    2001-01-01

    Completely revised text focuses on use of spectral methods to solve boundary value, eigenvalue, and time-dependent problems, but also covers Hermite, Laguerre, rational Chebyshev, sinc, and spherical harmonic functions, as well as cardinal functions, linear eigenvalue problems, matrix-solving methods, coordinate transformations, methods for unbounded intervals, spherical and cylindrical geometry, and much more. 7 Appendices. Glossary. Bibliography. Index. Over 160 text figures.

  18. Application of Rader transforms to the analysis of nuclear spectral data

    Kekre, H.B.; Madan, V.K.; Bairi, B.R.

    1988-01-01

    This paper describes a Rader transform method using a special arithmetic for the processing of nuclear spectral data. Rader transforms offer impressive computational savings vis-a-vis Fourier transform methods. Rader transforms require only integer additions and word shifts but no multiplications while Fourier transforms require complex arithmetic operations. Moreover, use of Rader transforms gives exact computations without any roundoff errors and does not require storage of basis functions. They are 'the best transforms' for computer processing of nuclear spectral data. Rader transforms using a Fermat prime 65 537 have been applied to deconvolve observed spectral data using a special filter function. A uniform improvement in resolution of 45% has been observed both in single and double spectrallines. A FORTRAN program GAMRAD is written to deconvolve spectral data using the special filter function. (orig.)

  19. Abundance estimation of spectrally similar minerals

    Debba, Pravesh

    2009-07-01

    Full Text Available This paper evaluates a spectral unmixing method for estimating the partial abundance of spectrally similar minerals in complex mixtures. The method requires formulation of a linear function of individual spectra of individual minerals. The first...

  20. DFT/TDDFT study on the electronic structure and spectral properties in annulated analogue of phenyl heteroazulene derivative

    Gasiorski, P.; Danel, K.S.; Matusiewicz, M.; Uchacz, T.; Kuźnik, W.; Piatek, Ł.; Kityk, A.V.

    2012-01-01

    Highlights: ► Cyclic voltammetry study of heteroazulene derivative PTNA. ► DFT/TDDFT/PCM calculations of molecular geometry and electronic states in PTNA. ► TDDFT/PCM calculations of the absorption and fluorescence spectra in PTNA. ► Comparison between TDDFT/PCM calculated and measured optical spectra. - Abstract: Paper reports the DFT/TDDFT study on the electronic structure and spectral properties of the seven-membered annulated heteroazulene derivative 6-phenyl-6H-5,6,7-triazadibenzo[f,h]naphtho[3,2,1-cd]azulene (PTNA) by means of polarizable continuum model (PCM) and Lippert–Mataga–Onsager reaction field (LM-ORF) model at the B3LYP/6-31+G(d,p) level of theory. The results of calculations are compared with the measured optical absorption and fluorescence spectra as well as with the cyclic voltammetry data. The DFT/TDDFT methods exhibit rather good quantitative agreement regarding the spectral position of the first absorption band; the discrepancy between the experiment and theory is less than 0.1 eV. As for the fluorescence emission the TDDFT calculations underestimate the transition energy of about 0.45 eV. The discrepancy should be attributed to insufficient accuracy of the TDDFT optimization in the excited state. In the polar solvent environment, all the TDDFT/PCM approaches give the bathochromic (red) shift for the fluorescence emission and the hypsochromic (blue) shift for the optical absorption in accordance with the experimental observation. As for the fluorescence emission fairly good agreement with the experiment provides the hybrid approach being the combination of the TDDFT/PCM optimization with the semiempirical electronic structure calculations by PM3 method and solvation LM-ORF model predicting the emission energy in different solvents with the accuracy better than 0.06 eV.

  1. Enormous periodic doppler shifts in SS 433

    Margon, B.; Ford, H.C.; Grandi, S.A.; Stone, R.P.S.

    1979-01-01

    We have previously reported prominent ''moving' emission lines in the visible spectrum of Stephenson-Sanduleak 433, the optical counterpart of a variable radio and X-ray source. Further observations show that despite the implausible velocities and changes in velocities implied if the moving features are interpreted as Doppler-shifted Balmer lines, this explanation is indeed correct. Spectroscopy of SS 433 on 51 mights in 1978--1979 reveals that the unidentified features are two sets of Balmer and He I lines, one with large and changing redshift, and the other with large and changing blueshift. Combining our data with published earlier observations, we obtain Doppler shifts on 80 nights in the period 1978 June to 1979 June. These data indicate that the velocity variations are cyclical, repeating in both the blueshift and redshift systems with a period of 164 +- 3 days. The two systems have thus far been observed to reach maximum positive and negative radial velocities of +50,000 and -35,000 km s -1 , respectively, are always symmetric about redshift z=0.04, and follow roughly sinusoidal velocity curves. We discuss in addition a variety of interesting short-term spectroscopic details, including minor but highly significant deviations of the radial velocity from the sinusoid, and nightly line profile changes, sometimes appearing as mirror-image events in the redshift and blueshift systems. The behavior of SS 433 is unprecedented

  2. Calibration with near-continuous spectral measurements

    Nielsen, Henrik Aalborg; Rasmussen, Michael; Madsen, Henrik

    2001-01-01

    In chemometrics traditional calibration in case of spectral measurements express a quantity of interest (e.g. a concentration) as a linear combination of the spectral measurements at a number of wavelengths. Often the spectral measurements are performed at a large number of wavelengths and in thi...... by an example in which the octane number of gasoline is related to near infrared spectral measurements. The performance is found to be much better that for the traditional calibration methods....

  3. Heart rate variability changes in business process outsourcing employees working in shifts.

    Kunikullaya, Kirthana U; Kirthi, Suresh K; Venkatesh, D; Goturu, Jaisri

    2010-10-31

    Irregular and poor quality sleep is common in business process outsourcing (BPO) employees due to continuous shift working. The influence of this on the cardiac autonomic activity was investigated by the spectral analysis of heart rate variability (HRV). 36 night shift BPO employees (working from 22:00 to 06:00h) and 36 age and sex matched day shift BPO employees (working from 08:00 to 16:00h) were recruited for the study. Five minute electrocardiogram (ECG) was recorded in all the subjects. Heart rate variability was analyzed by fast Fourier transformation using RMS Vagus HRV software. The results were analyzed using Mann Whitney U test, Student t-test, Wilcoxon signed rank test and were expressed as mean ± SD. Sleepiness was significantly higher among night shift workers as measured by Epworth Sleepiness Scale (p<0.001). Night shift BPO employees were found to have a trend towards lower values of vagal parameters - HF power (ms(2)), and higher values of sympathovagal parameters like LF Power (ms(2)) and the LF/HF power (%) suggesting decreased vagal activity and sympathetic over activity, when compared to day shift employees. However, HRV parameters did not vary significantly between the day shift employees and night shift workers baseline values, and also within the night shift group. Night shift working increased the heart rate and shifted the sympathovagal balance towards sympathetic dominance and decreased vagal parameters of HRV. This is an indicator of unfavorable change in the myocardial system, and thus shows increased risk of cardiovascular disease among the night shift employees.

  4. USGS Spectral Library Version 7

    Kokaly, Raymond F.; Clark, Roger N.; Swayze, Gregg A.; Livo, K. Eric; Hoefen, Todd M.; Pearson, Neil C.; Wise, Richard A.; Benzel, William M.; Lowers, Heather A.; Driscoll, Rhonda L.; Klein, Anna J.

    2017-04-10

    We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified, so that unique spectral features of a material can be related to its chemical structure. These spectro-chemical links are important for interpreting remotely sensed data collected in the field or from an aircraft or spacecraft. This library also contains physically constructed as well as mathematically computed mixtures. Four different spectrometer types were used to measure spectra in the library: (1) Beckman™ 5270 covering the spectral range 0.2 to 3 µm, (2) standard, high resolution (hi-res), and high-resolution Next Generation (hi-resNG) models of Analytical Spectral Devices (ASD) field portable spectrometers covering the range from 0.35 to 2.5 µm, (3) Nicolet™ Fourier Transform Infra-Red (FTIR) interferometer spectrometers covering the range from about 1.12 to 216 µm, and (4) the NASA Airborne Visible/Infra-Red Imaging Spectrometer AVIRIS, covering the range 0.37 to 2.5 µm. Measurements of rocks, soils, and natural mixtures of minerals were made in laboratory and field settings. Spectra of plant components and vegetation plots, comprising many plant types and species with varying backgrounds, are also in this library. Measurements by airborne spectrometers are included for forested vegetation plots, in which the trees are too tall for measurement by a field spectrometer. This report describes the instruments used, the organization of materials into chapters, metadata descriptions of spectra and samples, and possible artifacts in the spectral measurements. To facilitate greater application of the spectra, the library has also been convolved to selected spectrometer and imaging spectrometers sampling and

  5. Spectral properties of generalized eigenparameter dependent ...

    Jost function, spectrum, the spectral singularities, and the properties of the principal vectors corresponding to the spectral singularities of L, if. ∞Σn=1 n(∣1 - an∣ + ∣bnl) < ∞. Mathematics Subject Classication (2010): 34L05, 34L40, 39A70, 47A10, 47A75. Key words: Discrete equations, eigenparameter, spectral analysis, ...

  6. Calibrating spectral images using penalized likelihood

    Heijden, van der G.W.A.M.; Glasbey, C.

    2003-01-01

    A new method is presented for automatic correction of distortions and for spectral calibration (which band corresponds to which wavelength) of spectral images recorded by means of a spectrograph. The method consists of recording a bar-like pattern with an illumination source with spectral bands

  7. Adinkras, Dessins, Origami, and Supersymmetry Spectral Triples

    Marcolli, Matilde; Zolman, Nick

    2016-01-01

    We investigate the spectral geometry and spectral action functionals associated to 1D Supersymmetry Algebras, using the classification of these superalgebras in terms of Adinkra graphs and the construction of associated dessin d'enfant and origami curves. The resulting spectral action functionals are computed in terms of the Selberg (super) trace formula.

  8. Socioeconomic Development and Shifts in Mate Preferences

    Emily A. Stone

    2008-07-01

    Full Text Available Mate preferences shift according to contexts such as temporal duration of mateship sought and ecological prevalence of parasites. One important cross-cultural context that has not been explored is a country's socioeconomic development. Because individuals in less developed countries are generally less healthy and possess fewer resources than those in more developed countries, displays of health and resources in a prospective long-term partner were hypothesized to be valued more in populations in which they are rare than in populations in which they are more common. We also predicted negative correlations between development and preferences for similar religious background and a desire for children. We found strong support for the health hypothesis and modest support for the resource acquisition potential hypothesis. We also found an unpredicted positive correlation between development and importance ratings for love. Discussion addresses limitations of the current research and highlights directions for future cross-cultural research on mating psychology.

  9. Shift work and its association with metabolic disorders.

    Brum, Maria Carlota Borba; Filho, Fábio Fernandes Dantas; Schnorr, Claudia Carolina; Bottega, Gustavo Borchardt; Rodrigues, Ticiana C

    2015-01-01

    Although the health burden of shift work has not been extensively studied, evidence suggests that it may affect the metabolic balance and cause obesity and other metabolic disorders. Sleep deprivation, circadian desynchronization and behavioral changes in diet and physical activity are among the most commonly mentioned factors in studies of the association between night work and metabolic disorders. Individual adaptation to night work depends greatly on personal factors such as family and social life, but occupational interventions may also make a positive contribution to the transition to shift work, such as exposure to bright lights during the night shift, melatonin use, shift regularity and clockwise rotation, and dietary adaptations for the metabolic needs of night workers. The evaluation of the impact of night work on health and of the mechanisms underlying this relationship can serve as a basis for intervention strategies to minimize the health burden of shift work. This review aimed to identify highlights regarding therapeutic implications following the association between night and shift work and metabolic disorders, as well as the mechanisms and pathways responsible for these relationships.

  10. Alternative approaches to providing engineering expertise on shift

    Olson, J.; Schreiber, R.E.; Melber, B.D.

    1984-05-01

    This report represents the conclusions of a project studying the role of engineering expertise on shift in nuclear power plants. Using the present shift technical advisor (STA) position as the base case, several alternatives are analyzed. On-shift alternatives included the STA, the SS (shift supervisor), and the SE (shift engineer). The SE is degreed, experienced, trained, and licensed as a Senior Reactor Operator. Some non-shift alternatives were also studied. These included a cadre of on-call engineers and specialists within continual contact and easy reach of the plant; a technical system of phone and data lines linking the plant with a facility similar to an on-site technical support center; and finally, an SPDS (safety parameter display system) to agument technical upgrading of operator aids presently available. Potential problems considered in the analysis of implementation of these alternatives included job content constraints, problems of crew acceptance, and problems of labor supply and retention. Of the considered alternatives, the SE and SS options appear superior to the current STA approach. The SE approach appears the easiest to implement and the most effective under varied plant conditions. The SE may also serve as liaison to off-site support facilities

  11. PARAssign-paramagnetic NMR assignments of protein nuclei on the basis of pseudocontact shifts

    Skinner, Simon P., E-mail: skinnersp@chem.leidenuniv.nl [Leiden University, Gorlaeus Laboratories, Leiden Institute of Chemistry (Netherlands); Moshev, Mois, E-mail: mois@monomon.me [Leiden University, Leiden Institute of Advanced Computer Science (Netherlands); Hass, Mathias A. S., E-mail: hassmas@chem.leidenuniv.nl; Ubbink, Marcellus, E-mail: m.ubbink@chem.leidenuniv.nl [Leiden University, Gorlaeus Laboratories, Leiden Institute of Chemistry (Netherlands)

    2013-04-15

    The use of paramagnetic NMR data for the refinement of structures of proteins and protein complexes is widespread. However, the power of paramagnetism for protein assignment has not yet been fully exploited. PARAssign is software that uses pseudocontact shift data derived from several paramagnetic centers attached to the protein to obtain amide and methyl assignments. The ability of PARAssign to perform assignment when the positions of the paramagnetic centers are known and unknown is demonstrated. PARAssign has been tested using synthetic data for methyl assignment of a 47 kDa protein, and using both synthetic and experimental data for amide assignment of a 14 kDa protein. The complex fitting space involved in such an assignment procedure necessitates that good starting conditions are found, both regarding placement and strength of paramagnetic centers. These starting conditions are obtained through automated tensor placement and user-defined tensor parameters. The results presented herein demonstrate that PARAssign is able to successfully perform resonance assignment in large systems with a high degree of reliability. This software provides a method for obtaining the assignments of large systems, which may previously have been unassignable, by using 2D NMR spectral data and a known protein structure.

  12. Spectral multitude and spectral dynamics reflect changing conjugation length in single molecules of oligophenylenevinylenes

    Kobayashi, Hiroyuki; Tsuchiya, Kousuke; Ogino, Kenji; Vacha, Martin

    2012-01-01

    Single-molecule study of phenylenevinylene oligomers revealed distinct spectral forms due to different conjugation lengths which are determined by torsional defects. Large spectral jumps between different spectral forms were ascribed to torsional flips of a single phenylene ring. These spectral changes reflect the dynamic nature of electron delocalization in oligophenylenevinylenes and enable estimation of the phenylene torsional barriers. © 2012 The Owner Societies.

  13. Spectral BRDF measurements of metallic samples for laser processing applications

    Vitali, L; Fustinoni, D; Gramazio, P; Niro, A

    2015-01-01

    The spectral bidirectional reflectance distribution function (BRDF) of metals plays an important role in industrial processing involving laser-surface interaction. In particular, in laser metal machining, absorbance is strongly dependent on the radiation incidence angle as well as on finishing and contamination grade of the surface, and in turn it can considerably affect processing results. Very recently, laser radiation is also used to structure metallic surfaces, in order to produce many particular optical effects, ranging from a high level polishing to angular color shifting. Of course, full knowledge of the spectral BRDF of these structured layers makes it possible to infer reflectance or color for any irradiation and viewing angles. In this paper, we present Vis-NIR spectral BRDF measurements of laser-polished metallic, opaque, flat samples commonly employed in such applications. The resulting optical properties seem to be dependent on the atmospheric composition during the polishing process in addition to the roughness. The measurements are carried out with a Perkin Elmer Lambda 950 double-beam spectrophotometer, equipped with the Absolute Reflectance/Transmittance Analyzer (ARTA) motorized goniometer. (paper)

  14. Spectral methods. Fundamentals in single domains

    Canuto, C.

    2006-01-01

    Since the publication of ''Spectral Methods in Fluid Dynamics'' 1988, spectral methods have become firmly established as a mainstream tool for scientific and engineering computation. The authors of that book have incorporated into this new edition the many improvements in the algorithms and the theory of spectral methods that have been made since then. This latest book retains the tight integration between the theoretical and practical aspects of spectral methods, and the chapters are enhanced with material on the Galerkin with numerical integration version of spectral methods. The discussion of direct and iterative solution methods is also greatly expanded. (orig.)

  15. Gastrointestinal complaints in shift-working and day-working nurses in Iran

    Moravveji Ali

    2010-10-01

    Full Text Available Abstract Background There is evidence in the scientific literature of the adverse physiological and psychological effects of shift work. The work of nurses in hospitals is connected with shift and night work. Several publications have described gastrointestinal disturbances in shift workers. The aim of this study was to compare the frequency of gastrointestinal (GI complaints of nurses on a rotating shift with that of nurses on a regular day shift. Methods The study involved 160 nurses (133 working in shifts and at night and 27 working on day shifts in the Shahid Beheshti Hospital in Kashan, Iran. These nurses answered a Gastrointestinal Symptom Questionnaire regarding the presence of gastrointestinal symptoms (including heartburn, regurgitation, constipation, diarrhea and bloating. Positive responses required frequent symptom occurrence in the past 4 weeks. Significance of group differences was assessed by chi-square and Fisher-exact tests. Results Prevalence of GI symptoms was significantly higher (p = 0.009 in rotating-shift nurses (81.9% than in day-shift nurses (59.2%. Irregular meal consumption (p = 0.01 and GI medications (p = 0.002 were all significantly higher among the rotating shift nurses. In both groups, regurgitation was the most common symptom. Conclusion Nurses on rotating shifts in Iran experience more GI disturbances than do nurses on day shifts.

  16. Origin of the blue shift of the CH stretching band for 2-butoxyethanol in water.

    Katsumoto, Yukiteru; Komatsu, Hiroyuki; Ohno, Keiichi

    2006-07-26

    The blue shift of the isolated CD stretching band of 2-butoxyethanol (C4E1), which is observed for the aqueous solution during the dilution process, has been investigated by infrared (IR) spectroscopy and quantum chemical calculations. Mono-deuterium-labeled C4E1's were employed to remove the severe overlapping among the CH stretching bands. The isolated CD stretching mode of the alpha-methylene in the butoxy group shows a large blue shift, while those of the beta-methylene and methyl groups are not largely shifted. The spectral simulation results for the C4E1/H2O complexes indicate that the large blue shift of the CD stretching band of the butoxy group arises mainly from the hydration of the ether oxygen atom.

  17. Algorithms for image recovery calculation in extended single-shot phase-shifting digital holography

    Hasegawa, Shin-ya; Hirata, Ryo

    2018-04-01

    The single-shot phase-shifting method of image recovery using an inclined reference wave has the advantages of reducing the effects of vibration, being capable of operating in real time, and affording low-cost sensing. In this method, relatively low reference angles compared with that in the conventional method using phase shift between three or four pixels has been required. We propose an extended single-shot phase-shifting technique which uses the multiple-step phase-shifting algorithm and the corresponding multiple pixels which are the same as that of the period of an interference fringe. We have verified the theory underlying this recovery method by means of Fourier spectral analysis and its effectiveness by evaluating the visibility of the image using a high-resolution pattern. Finally, we have demonstrated high-contrast image recovery experimentally using a resolution chart. This method can be used in a variety of applications such as color holographic interferometry.

  18. The Comparison between Spectral and Entropic Measures Following Fatigue in Erector Spinae Muscles

    Saeed Talebian

    2016-03-01

    Full Text Available Background: Surface electromyography (sEMG of muscles is a non-invasive tool that can be helpful in the assessment of muscle function and some motor control evaluations. A loss of force, known as muscle fatigue is accompanied by changes in muscle electrical activity. One of the most commonly used surface EMG parameters which reflects paraspinal muscle fatigue during different tasks and positions is median frequency. Although it is widely known that the electromyography power spectrum shifts to lower frequencies during fatiguing contraction, an opinion exists that the validity of spectral shifts in assessment of fatigue is questionable. Some researchers have examined whether other quantities derived from sEMG signals are better indicators for muscle fatigue. Following cyclic flexion/extension and consequence fatigue, variation in sEMG signals may be complex for study. The aim of this study was to determine which of the median frequency (MF or entropic (ENTR is more sensitive for measuring muscular fatigue in erector spinae muscles during cyclic flexion/extension. Methods: Surface electromyography of erector spine muscles was recorded in 25 healthy subjects during cyclic dynamic contractions. The experimental session consisted of two parts: measurement of Maximal Voluntary Contraction (MVC, and performing the fatigue test. All subjects performed rhythmic flexion/extension with 50% MVC loading against B-200 Isostation, about 4-6 minutes. The MF and ENTR of the muscle activities were computed to assess muscular fatigue. Results: Paired sample t-tests showed that MF and ENTR changes after fatigue test were significant (P<0.001. Percentage changes of both MF and ENTR were reduced, this reduction for ENTR was more than 40% (P<0.001. Conclusion: It seems that the changes of ENTR in muscle activities have the ability to measure muscular fatigue and is more sensitive in comparison to MF.

  19. Spectrally edited 2D 13Csbnd 13C NMR spectra without diagonal ridge for characterizing 13C-enriched low-temperature carbon materials

    Johnson, Robert L.; Anderson, Jason M.; Shanks, Brent H.; Fang, Xiaowen; Hong, Mei; Schmidt-Rohr, Klaus

    2013-09-01

    Two robust combinations of spectral editing techniques with 2D 13Csbnd 13C NMR have been developed for characterizing the aromatic components of 13C-enriched low-temperature carbon materials. One method (exchange with protonated and nonprotonated spectral editing, EXPANSE) selects cross peaks of protonated and nearby nonprotonated carbons, while the other technique, dipolar-dephased double-quantum/single-quantum (DQ/SQ) NMR, selects signals of bonded nonprotonated carbons. Both spectra are free of a diagonal ridge, which has many advantages: Cross peaks on the diagonal or of small intensity can be detected, and residual spinning sidebands or truncation artifacts associated with the diagonal ridge are avoided. In the DQ/SQ experiment, dipolar dephasing of the double-quantum coherence removes protonated-carbon signals; this approach also eliminates the need for high-power proton decoupling. The initial magnetization is generated with minimal fluctuation by combining direct polarization, cross polarization, and equilibration by 13C spin diffusion. The dipolar dephased DQ/SQ spectrum shows signals from all linkages between aromatic rings, including a distinctive peak from polycondensed aromatics. In EXPANSE NMR, signals of protonated carbons are selected in the first spectral dimension by short cross polarization combined with dipolar dephasing difference. This removes ambiguities of peak assignment to overlapping signals of nonprotonated and protonated aromatic carbons, e.g. near 125 ppm. Spin diffusion is enhanced by dipolar-assisted rotational resonance. Before detection, Csbnd H dipolar dephasing by gated decoupling is applied, which selects signals of nonprotonated carbons. Thus, only cross peaks due to magnetization originating from protonated C and ending on nearby nonprotonated C are retained. Combined with the chemical shifts deduced from the cross-peak position, this double spectral editing defines the bonding environment of aromatic, COO, and Cdbnd O carbons

  20. Limitation of Piston Centre Shift in Free Piston Stirling Engines

    Van der Woude, R.R. [ECN Energy in the Built Environment and Networks, Petten (Netherlands)

    2006-09-15

    Piston centre shift is one of the phenomena setting Free Piston engines apart from traditional kinematic engines. In kinematic engines the piston centre position is determined by the design of the engine's internal mechanisms. In Free Piston engines however, the piston's mid-stroke position is determined by the balance of forces acting on the piston, in particular flexure and gas pressure forces. As a result, a mean pressure difference across the piston emerging during engine operation will cause the piston mid-stroke position to shift away from the geometrical centre. This process will continue until a new balance is reached with the flexure forces counteracting the new mean pressure balance. Yet, before the new equilibrium is reached, the resulting piston centre shift may have grown to such an extent that piston overstrokes have become inevitable. In order to limit piston centre shift and prevent piston overstrokes, several solutions have been proposed in the past. Popular solutions include ingenious mechanisms to vent gas between the spaces separated by the piston, in an attempt to limit the pressure difference. Enatec however has adopted a different approach by applying a precisely determined clearance between the piston and cylinder. With the right shape the clearance effectively limits the mean pressure difference across the piston and therefore limits the extent of the piston centre drift. Taking benefit of tightly controlled tolerances of both piston and cylinder, Enatec has demonstrated the effectiveness of this simple concept in series produced engines.

  1. ISSP Position Stand

    Ryba, Tatiana; Stambulova, Natalia; Si, Gangyan

    2013-01-01

    The multicultural landscape of contemporary sport sets a challenge to rethink sport and exercise psychology research and practice through a culturally re␣exive lens. This ISSP Position Stand provides a rigorous synthesis and engagement with existing scholarship to outline a roadmap for future work...... in the ␣eld. The shift to culturally competent sport and exercise psychology implies: (a) recognizing hidden ethnocentric philosophical assumptions permeating much of the current theory, research, and practice; (b) transitioning to professional ethics in which difference is seen as not inherent and ␣xed...... but as relational and ␣uid; and (c) focusing on meaning (instead of cause) in cross-cultural and cultural research projects, and cultural praxis work. In the paper, we ␣rst provide an overview of the concepts of cultural competence and ethics of difference. Second, we present a step-by-step approach for developing...

  2. An approach to estimate spatial distribution of analyte within cells using spectrally-resolved fluorescence microscopy

    Sharma, Dharmendar Kumar; Irfanullah, Mir; Basu, Santanu Kumar; Madhu, Sheri; De, Suman; Jadhav, Sameer; Ravikanth, Mangalampalli; Chowdhury, Arindam

    2017-03-01

    While fluorescence microscopy has become an essential tool amongst chemists and biologists for the detection of various analyte within cellular environments, non-uniform spatial distribution of sensors within cells often restricts extraction of reliable information on relative abundance of analytes in different subcellular regions. As an alternative to existing sensing methodologies such as ratiometric or FRET imaging, where relative proportion of analyte with respect to the sensor can be obtained within cells, we propose a methodology using spectrally-resolved fluorescence microscopy, via which both the relative abundance of sensor as well as their relative proportion with respect to the analyte can be simultaneously extracted for local subcellular regions. This method is exemplified using a BODIPY sensor, capable of detecting mercury ions within cellular environments, characterized by spectral blue-shift and concurrent enhancement of emission intensity. Spectral emission envelopes collected from sub-microscopic regions allowed us to compare the shift in transition energies as well as integrated emission intensities within various intracellular regions. Construction of a 2D scatter plot using spectral shifts and emission intensities, which depend on the relative amount of analyte with respect to sensor and the approximate local amounts of the probe, respectively, enabled qualitative extraction of relative abundance of analyte in various local regions within a single cell as well as amongst different cells. Although the comparisons remain semi-quantitative, this approach involving analysis of multiple spectral parameters opens up an alternative way to extract spatial distribution of analyte in heterogeneous systems. The proposed method would be especially relevant for fluorescent probes that undergo relatively nominal shift in transition energies compared to their emission bandwidths, which often restricts their usage for quantitative ratiometric imaging in

  3. Planck 2013 results. IX. HFI spectral response

    Ade, P A R; Armitage-Caplan, C; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bobin, J; Bock, J J; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Bridges, M; Bucher, M; Burigana, C; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chen, X; Chiang, L -Y; Chiang, H C; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Comis, B; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Falgarone, E; Finelli, F; Forni, O; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Giard, M; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Hansen, F K; Hanson, D; Harrison, D; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Hurier, G; Jaffe, T R; Jaffe, A H; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leahy, J P; Leonardi, R; Leroy, C; Lesgourgues, J; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Matthai, F; Mazzotta, P; McGehee, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; North, C; Noviello, F; Novikov, D; Novikov, I; Osborne, S; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rusholme, B; Santos, D; Savini, G; Shellard, E P S; Spencer, L D; Starck, J -L; Stolyarov, V; Stompor, R; Sudiwala, R; Sureau, F; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Tomasi, M; Tristram, M; Tucci, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    The Planck High Frequency Instrument (HFI) spectral response was determined through a series of ground based tests conducted with the HFI focal plane in a cryogenic environment prior to launch. The main goal of the spectral transmission tests was to measure the relative spectral response (including out-of-band signal rejection) of all HFI detectors. This was determined by measuring the output of a continuously scanned Fourier transform spectrometer coupled with all HFI detectors. As there is no on-board spectrometer within HFI, the ground-based spectral response experiments provide the definitive data set for the relative spectral calibration of the HFI. The spectral response of the HFI is used in Planck data analysis and component separation, this includes extraction of CO emission observed within Planck bands, dust emission, Sunyaev-Zeldovich sources, and intensity to polarization leakage. The HFI spectral response data have also been used to provide unit conversion and colour correction analysis tools. Ver...

  4. Nonlocal optical effects on the Goos–Hänchen shifts at multilayered hyperbolic metamaterials

    Chen, Chih-Wei; Bian, Tingting; Chiang, Hai-Pang; Leung, P T

    2016-01-01

    The lateral beam shift of light incident on a multilayered hyperbolic metamaterial (HMM) is investigated using a theoretical model which emphasizes the nonlocal optical response of the indefinite material. By applying an effective local response theory formulated recently in the literature, it is found that nonlocal effects only affect p polarized light in this Goos–Hänchen (GH) shift of the incident beam; leading to a blue-shifted peak for positive shifts at high frequencies and red-shifted dip for negative shifts at low frequencies in the GH shift spectrum. An account for the observed phenomenon is given by referring to the ‘Brewster condition’ for the reflected wave from the HMM. This observation thus provides a relatively direct probe for the nonlocal response of the HMM. (paper)

  5. A hypothesis-testing framework for studies investigating ontogenetic niche shifts using stable isotope ratios.

    Caroline M Hammerschlag-Peyer

    Full Text Available Ontogenetic niche shifts occur across diverse taxonomic groups, and can have critical implications for population dynamics, community structure, and ecosystem function. In this study, we provide a hypothesis-testing framework combining univariate and multivariate analyses to examine ontogenetic niche shifts using stable isotope ratios. This framework is based on three distinct ontogenetic niche shift scenarios, i.e., (1 no niche shift, (2 niche expansion/reduction, and (3 discrete niche shift between size classes. We developed criteria for identifying each scenario, as based on three important resource use characteristics, i.e., niche width, niche position, and niche overlap. We provide an empirical example for each ontogenetic niche shift scenario, illustrating differences in resource use characteristics among different organisms. The present framework provides a foundation for future studies on ontogenetic niche shifts, and also can be applied to examine resource variability among other population sub-groupings (e.g., by sex or phenotype.

  6. Spectral representation in stochastic quantization

    Nakazato, Hiromichi.

    1988-10-01

    A spectral representation of stationary 2-point functions is investigated based on the operator formalism in stochastic quantization. Assuming the existence of asymptotic non-interacting fields, we can diagonalize the total Hamiltonian in terms of asymptotic fields and show that the correlation length along the fictious time is proportional to the physical mass expected in the usual field theory. A relation between renormalization factors in the operator formalism is derived as a byproduct and its validity is checked with the perturbative results calculated in this formalism. (orig.)

  7. Spectral Tensor-Train Decomposition

    Bigoni, Daniele; Engsig-Karup, Allan Peter; Marzouk, Youssef M.

    2016-01-01

    The accurate approximation of high-dimensional functions is an essential task in uncertainty quantification and many other fields. We propose a new function approximation scheme based on a spectral extension of the tensor-train (TT) decomposition. We first define a functional version of the TT...... adaptive Smolyak approach. The method is also used to approximate the solution of an elliptic PDE with random input data. The open source software and examples presented in this work are available online (http://pypi.python.org/pypi/TensorToolbox/)....

  8. Cortisol shifts financial risk preferences.

    Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S; Fletcher, Paul C; Gurnell, Mark; Coates, John

    2014-03-04

    Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability.

  9. Cortisol shifts financial risk preferences

    Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S.; Fletcher, Paul C.; Gurnell, Mark; Coates, John

    2014-01-01

    Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability. PMID:24550472

  10. On the counting rate-dependent amplitude shifts in proportional counters

    Mahesh, K.

    1976-01-01

    The presence of a positive ion cloud near the anode wire, which has been believed to be the cause of the observed counting rate-dependent peak shifts in proportional counters, does not explain various exhibited features of these shifts. The possibility of other mechanisms involved is, therefore, examined. The columnar recombination of primary ions in the counter is considered to explain the origin of the shifts and their observed features. (Auth.)

  11. Broadband Spectral Investigations of Magnetar Bursts

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin

    2017-09-01

    We present our broadband (2-250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550-5418, SGR 1900+14, and SGR 1806-20 detected with the Rossi X-ray Timing Explorer (RXTE) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  12. Broadband Spectral Investigations of Magnetar Bursts

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin, E-mail: demetk@sabanciuniv.edu [Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı Tuzla, Istanbul 34956 (Turkey)

    2017-09-01

    We present our broadband (2–250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550−5418, SGR 1900+14, and SGR 1806−20 detected with the Rossi X-ray Timing Explorer ( RXTE ) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  13. Rotating shift work associated with obesity in men from northeastern Ontario.

    Grundy, Anne; Cotterchio, Michelle; Kirsh, Victoria A; Nadalin, Victoria; Lightfoot, Nancy; Kreiger, Nancy

    2017-08-01

    While some studies have suggested associations between shift work and obesity, few have been population-based or considered multiple shift schedules. Since obesity is linked with several chronic health conditions, understanding which types of shift work influence obesity is important and additional work with more detailed exposure assessment of shift work is warranted. Using multivariate polytomous logistic regression, we investigated the associations between shift work (evening/night, rotating and other shift schedules) and overweight and obesity as measured by body mass index cross-sectionally among 1561 men. These men had previously participated as population controls in a prostate cancer case-control study conducted in northeastern Ontario from 1995 to 1999. We obtained information on work history (including shift work), height and weight from the existing self-reported questionnaire data. We observed an association for ever (vs. never) having been employed in rotating shift work for both the overweight (OR [odds ratio] = 1.34; 95% CI [confidence interval]: 1.05-1.73) and obese (OR = 1.57; 95% CI: 1.12-2.21) groups. We also observed nonsignificant associations for ever (vs. never) having been employed in permanent evening/night shifts. In addition, we found a significant trend of increased risk for both overweight and obesity with increasing duration of rotating shift work. Both the positive association between rotating shift work and obesity and the suggested positive association for permanent evening/night shift work in this study are consistent with previous findings. Future population-based research that is able to build on our results while examining additional shift work characteristics will further clarify whether some shift patterns have a greater impact on obesity than others.

  14. Rotating shift work associated with obesity in men from northeastern Ontario

    Anne Grundy

    2017-08-01

    Full Text Available Introduction: While some studies have suggested associations between shift work and obesity, few have been population-based or considered multiple shift schedules. Since obesity is linked with several chronic health conditions, understanding which types of shift work influence obesity is important and additional work with more detailed exposure assessment of shift work is warranted. Methods: Using multivariate polytomous logistic regression, we investigated the associations between shift work (evening/night, rotating and other shift schedules and overweight and obesity as measured by body mass index cross-sectionally among 1561 men. These men had previously participated as population controls in a prostate cancer case-control study conducted in northeastern Ontario from 1995 to 1999. We obtained information on work history (including shift work, height and weight from the existing self-reported questionnaire data. Results: We observed an association for ever (vs. never having been employed in rotating shift work for both the overweight (OR [odds ratio] = 1.34; 95% CI [confidence interval]: 1.05–1.73 and obese (OR = 1.57; 95% CI: 1.12–2.21 groups. We also observed nonsignificant associations for ever (vs. never having been employed in permanent evening/night shifts. In addition, we found a significant trend of increased risk for both overweight and obesity with increasing duration of rotating shift work. Conclusion: Both the positive association between rotating shift work and obesity and the suggested positive association for permanent evening/night shift work in this study are consistent with previous findings. Future population-based research that is able to build on our results while examining additional shift work characteristics will further clarify whether some shift patterns have a greater impact on obesity than others.

  15. Sensitivity of peak positions to flight-path parameters in a deep-inelastic scattering neutron TOF spectrometer

    Gray, E.MacA.; Chatzidimitriou-Dreismann, C.A.; Blach, T.P.

    2012-01-01

    The effects of small changes in flight-path parameters (primary and secondary flight paths, detector angles), and of displacement of the sample along the beam axis away from its ideal position, are examined for an inelastic time-of-flight (TOF) neutron spectrometer, emphasising the deep-inelastic regime. The aim was to develop a rational basis for deciding what measured shifts in the positions of spectral peaks could be regarded as reliable in the light of the uncertainties in the calibrated flight-path parameters. Uncertainty in the length of the primary or secondary flight path has the least effect on the positions of the peaks of H, D and He, which are dominated by the accuracy of the calibration of the detector angles. This aspect of the calibration of a TOF spectrometer therefore demands close attention to achieve reliable outcomes where the position of the peaks is of significant scientific interest and is discussed in detail. The corresponding sensitivities of the position of peak of the Compton profile, J(y), to flight-path parameters and sample position are also examined, focusing on the comparability across experiments of results for H, D and He. We show that positioning the sample to within a few mm of the ideal position is required to ensure good comparability between experiments if data from detectors at high forward angles are to be reliably interpreted.

  16. Spectral-Domain Measurement of Strain Sensitivity of a Two-Mode Birefringent Side-Hole Fiber

    Waclaw Urbanczyk

    2012-09-01

    Full Text Available The strain sensitivity of a two-mode birefringent side-hole fiber is measured in the spectral domain. In a simple experimental setup comprising a broadband source, a polarizer, a two-mode birefringent side-hole fiber under varied elongations, an analyzer and a compact spectrometer, the spectral interferograms are resolved. These are characterized by the equalization wavelength at which spectral interference fringes have the highest visibility (the largest period due to the zero group optical path difference between the fundamental, the LP01 mode and the higher-order, the LP11 mode. The spectral interferograms with the equalization wavelength are processed to retrieve the phase as a function of the wavelength. From the retrieved phase functions corresponding to different elongations of a two-mode birefringent side-hole fiber under test, the spectral strain sensitivity is obtained. Using this approach, the intermodal spectral strain sensitivity was measured for both x and y polarizations. Moreover, the spectral polarimetric sensitivity to strain was measured for the fundamental mode when a birefringent delay line was used in tandem with the fiber. Its spectral dependence was also compared with that obtained from a shift of the spectral interferograms not including the equalization wavelength, and good agreement was confirmed.

  17. In Situ Raman Spectral Characteristics of Carbon Dioxide in a Deep-Sea Simulator of Extreme Environments Reaching 300 ℃ and 30 MPa.

    Li, Lianfu; Du, Zengfeng; Zhang, Xin; Xi, Shichuan; Wang, Bing; Luan, Zhendong; Lian, Chao; Yan, Jun

    2018-01-01

    Deep-sea carbon dioxide (CO 2 ) plays a significant role in the global carbon cycle and directly affects the living environment of marine organisms. In situ Raman detection technology is an effective approach to study the behavior of deep-sea CO 2 . However, the Raman spectral characteristics of CO 2 can be affected by the environment, thus restricting the phase identification and quantitative analysis of CO 2 . In order to study the Raman spectral characteristics of CO 2 in extreme environments (up to 300 ℃ and 30 MPa), which cover most regions of hydrothermal vents and cold seeps around the world, a deep-sea extreme environment simulator was developed. The Raman spectra of CO 2 in different phases were obtained with Raman insertion probe (RiP) system, which was also used in in situ Raman detection in the deep sea carried by remotely operated vehicle (ROV) "Faxian". The Raman frequency shifts and bandwidths of gaseous, liquid, solid, and supercritical CO 2 and the CO 2 -H 2 O system were determined with the simulator. In our experiments (0-300 ℃ and 0-30 MPa), the peak positions of the symmetric stretching modes of gaseous CO 2, liquid CO 2 , and supercritical CO 2 shift approximately 0.6 cm -1 (1387.8-1388.4 cm -1 ), 0.7 cm -1 (1385.5-1386.2 cm -1 ), and 2.5 cm -1 (1385.7-1388.2 cm -1 ), and those of the bending modes shift about 1.0 cm -1 (1284.7-1285.7 cm -1 ), 1.9 cm -1 (1280.1-1282.0 cm -1 ), and 4.4 cm -1 (1281.0-1285.4 cm -1 ), respectively. The Raman spectral characteristics of the CO 2 -H 2 O system were also studied under the same conditions. The peak positions of dissolved CO 2 varied approximately 4.5 cm -1 (1282.5-1287.0 cm -1 ) and 2.4 cm -1 (1274.4-1276.8 cm -1 ) for each peak. In comparison with our experiment results, the phases of CO 2 in extreme conditions (0-3000 m and 0-300 ℃) can be identified with the Raman spectra collected in situ. This qualitative research on CO 2 can also support the

  18. Wavelength dependence of the Brillouin spectral width of boron doped germanosilicate optical fibers.

    Law, Pi-Cheng; Dragic, Peter D

    2010-08-30

    Boron co-doped germanosilicate fibers are investigated via the Brillouin light scattering technique using two wavelengths, 1534 nm and 1064 nm. Several fibers are investigated, including four drawn from the same preform but at different draw temperatures. The Stokes' shifts and the Brillouin spectral widths are found to increase with increasing fiber draw temperature. A frequency-squared law has adequately described the wavelength dependence of the Brillouin spectral width of conventional Ge-doped fibers. However, it is found that unlike conventional Ge-doped fibers these fibers do not follow the frequency-squared law. This is explained through a frequency-dependent dynamic viscosity that modifies this law.

  19. Curvature Effect and the Spectral Softening Phenomenon Detected ...

    soft spectral evolution, indicating that this spectral softening is not a rare phenomenon .... of time, there exists a temporal steep decay phase accompanied by spectral softening. (d) In most cases, the temporal power law index α and the spectral.

  20. Individual differences in shift work tolerance

    Lammers-van der Holst, H.M.

    2016-01-01

    Shift work is a key feature of our contemporary 24/7 society, employing several successive work teams to sustain around-the-clock operations. However, numerous studies imply that frequently shifting the periods of sleep and wakefulness poses a serious threat to the shift worker’s physical, mental

  1. Shifting Cultivation : Promoting Innovative Policy and Development ...

    Shifting Cultivation : Promoting Innovative Policy and Development Options in the Eastern Himalayas. Shifting ... pressure and market forces. The idea is to share good policies and practices related to shifting cultivation and alternative options through regional exchange. ... Les chaînes de valeur comme leviers stratégiques.

  2. Why victimology should stay positive: The ongoing need for positive victimology

    Ronel Natti

    2015-01-01

    Full Text Available This paper presents the need for positive victimology and its unique contribution to victimology. Victimology presented a shift in attention and awareness in practice, research and theory, by focusing on victims of crime and of abuse of power, and on victims’ rights and victims’ services. Positive victimology indicates a more specified shift in attention and awareness, within the larger shift of victimology. This shift stands in line with positive psychology, positive criminology and the idea of victims’ victimology. It denotes an approach to provide the following, as much as possible: 1. A wide range of social responses to the victims and their victimization that victims can experience as positive, 2. Positive outcomes of healing and recovery for victims, and 3. Positive integration of victims. Within each of those, positive victimology suggests a pragmatic coordinated system that ranges from definitions of negative poles to those of positive ones. When moving towards the positive pole at any given coordinate, a sense of justice is an important factor that might reduce the impact of the harm. Support is also a crucial factor and at the very positive pole, stands human, inter-personal love.

  3. Exogenous and endogenous shifts of attention in perihand space.

    Le Bigot, Nathalie; Grosjean, Marc

    2016-07-01

    While some studies have found that attentional orienting is altered in perihand space, most have not. One reason for such discrepancies may be related to the types of cues (uninformative and informative) that have been used, as they are known to induce different types of shifts of attention (exogenous and endogenous, respectively). To systematically address this question, two experiments were performed in which an uninformative peripheral cue (Experiment 1) or an informative central cue (Experiment 2) preceded a peripheral target with a short (100-150 ms) stimulus-onset asynchrony. Participants performed the task with their left hand, right hand, both hands, or no hands near the display. Cueing effects were obtained in both experiments, but they were only modulated by hand position in Experiment 1, with larger effects observed in the right- and both-hand conditions. These findings suggest that exogenous attention shifts are affected by hand proximity, while endogenous shifts are not.

  4. Tilt shift determinations with spatial-carrier phase-shift method in temporal phase-shift interferometry

    Liu, Qian; Wang, Yang; He, Jianguo; Ji, Fang; Wang, Baorui

    2014-01-01

    An algorithm is proposed to deal with tilt-shift errors in temporal phase-shift interferometry (PSI). In the algorithm, the tilt shifts are detected with the spatial-carrier phase-shift (SCPS) method and then the tilt shifts are applied as priori information to the least-squares fittings of phase retrieval. The algorithm combines the best features of the SCPS and the temporal PSI. The algorithm could be applied to interferograms of arbitrary aperture without data extrapolation for the Fourier transform is not involved. Simulations and experiments demonstrate the effectiveness of the algorithm. The statistics of simulation results show a satisfied accuracy in detecting tilt-shift errors. Comparisons of the measurements with and without environmental vibration show that the proposed algorithm could compensate tilt-shift errors and retrieve wavefront phase accurately. The algorithm provides an approach to retrieve wavefront phase for the temporal PSI in vibrating environment. (paper)

  5. Steady State Shift Damage Localization

    Sekjær, Claus; Bull, Thomas; Markvart, Morten Kusk

    2017-01-01

    The steady state shift damage localization (S3DL) method localizes structural deterioration, manifested as either a mass or stiffness perturbation, by interrogating the damage-induced change in the steady state vibration response with damage patterns cast from a theoretical model. Damage is, thus...... the required accuracy when examining complex structures, an extensive amount of degrees of freedom (DOF) must often be utilized. Since the interrogation matrix for each damage pattern depends on the size of the system matrices constituting the FE-model, the computational time quickly becomes of first......-order importance. The present paper investigates two sub-structuring approaches, in which the idea is to employ Craig-Bampton super-elements to reduce the amount of interrogation distributions while still providing an acceptable localization resolution. The first approach operates on a strict super-element level...

  6. Identical and shifted identical bands

    Dodder, R.S; Jones, E.F.; Hamilton, J.H.

    1997-01-01

    Spontaneous fission of 252 Cm was studied with 72 large Compton suppressed Ge detectors in Gamma sphere. New isotopes 160 Sm and 162 Gd were identified. Through X-ray-γ and γ-γ-γ) coincidence measurements, level energies were established to spins 14 + to 20 + in 152 , 154 156 60 Nd 92 94 96 , 156 , 158 , 160 62 Sm 94 , 96 , 98 , and 160 , 162 64 Gd 96 , 98 . These nuclei exhibit a remarkable variety of identical bands and bands where the energies and moments of inertia are shifted by the same constant amount for every spin state from 2 + to 12 + for various combinations of nuclei differing by 2n, 4n, 2p, 4p, and α

  7. In-flight spectral performance monitoring of the Airborne Prism Experiment.

    D'Odorico, Petra; Alberti, Edoardo; Schaepman, Michael E

    2010-06-01

    Spectral performance of an airborne dispersive pushbroom imaging spectrometer cannot be assumed to be stable over a whole flight season given the environmental stresses present during flight. Spectral performance monitoring during flight is commonly accomplished by looking at selected absorption features present in the Sun, atmosphere, or ground, and their stability. The assessment of instrument performance in two different environments, e.g., laboratory and airborne, using precisely the same calibration reference, has not been possible so far. The Airborne Prism Experiment (APEX), an airborne dispersive pushbroom imaging spectrometer, uses an onboard in-flight characterization (IFC) facility, which makes it possible to monitor the sensor's performance in terms of spectral, radiometric, and geometric stability in flight and in the laboratory. We discuss in detail a new method for the monitoring of spectral instrument performance. The method relies on the monitoring of spectral shifts by comparing instrument-induced movements of absorption features on ground and in flight. Absorption lines originate from spectral filters, which intercept the full field of view (FOV) illuminated using an internal light source. A feature-fitting algorithm is used for the shift estimation based on Pearson's correlation coefficient. Environmental parameter monitoring, coregistered on board with the image and calibration data, revealed that differential pressure and temperature in the baffle compartment are the main driving parameters explaining the trend in spectral performance deviations in the time and the space (across-track) domains, respectively. The results presented in this paper show that the system in its current setup needs further improvements to reach a stable performance. Findings provided useful guidelines for the instrument revision currently under way. The main aim of the revision is the stabilization of the instrument for a range of temperature and pressure conditions

  8. Temperature shift effect on the Chlorobaculum tepidum chlorosomes.

    Tang, Joseph Kuo-Hsiang; Xu, Ying; Muhlmann, Guillermo M; Zare, Farrokh; Khin, Yadana; Tam, Sun W

    2013-05-01

    Chlorobaculum [Cba.] tepidum is known to grow optimally at 48-52 °C and can also be cultured at ambient temperatures. In this paper, we prepared constant temperature, temperature shift, and temperature shift followed by backshift cultures and investigated the intrinsic properties and spectral features of chlorosomes from those cultures using various approaches, including temperature-dependent measurements on circular dichroism (CD), UV-visible, and dynamic light scattering. Our studies indicate that (1) chlorosomes from constant temperature cultures at 50 and 30 °C exhibited more resistance to heat relative to temperature shift cultures; (2) as temperature increases bacteriochlorophyll c (BChl c) in chlorosomes is prone to demetalation, which forms bacteriopheophytin c, and degradation under aerobic conditions. Some BChl c aggregates inside reduced chlorosomes prepared in low-oxygen environments can reform after heat treatments; (3) temperature shift cultures synthesize and incorporate more BChl c homologs with a smaller substituent at C-8 on the chlorin ring and less BChl c homologs with a larger long-chain alcohol at C-17(3) versus constant-temperature cultures. We hypothesize that the long-chain alcohol at C-17(3) (and perhaps together with the substituent at C-8) may account for thermal stability of chlorosomes and the substituent at C-8 may assist self-assembling BChls; and (4) while almost identical absorption spectra are detected, chlorosomes from different growth conditions exhibited differences in the rotational length of the CD signal, and aerobic and reduced chlorosomes also display different Qy CD intensities. Further, chlorosomes exhibited changes of CD features in response to temperature increases. Additionally, we compare temperature-dependent studies for the Cba. tepidum chlorosomes and previous studies for the Chloroflexus aurantiacus chlorosomes. Together, our work provides useful and novel insights on the properties and organization of

  9. Numerical analysis of the shifting slabs applied in a wireless power transfer system to enhance magnetic coupling

    Yayun Dong

    2017-05-01

    Full Text Available Shifting medium is a kind of metamaterial, which can optically shift a space or an object a certain distance away from its original position. Based on the shifting medium, we propose a concise pair of shifting slabs covering the transmitting or receiving coil in a two-coil wireless power transfer system to decrease the equivalent distance between the coils. The electromagnetic parameters of the shifting slabs are calculated by transformation optics. Numerical simulations validate that the shifting slabs can approximately shift the electromagnetic fields generated by the covered coil; thus, the magnetic coupling and the efficiency of the system are enhanced while remaining the physical transmission distance unchanged. We also verify the advantages of the shifting slabs over the magnetic superlens. Finally, we provide two methods to fabricate shifting slabs based on split-ring resonators.

  10. Numerical analysis of the shifting slabs applied in a wireless power transfer system to enhance magnetic coupling

    Dong, Yayun; Yang, Xijun; Jin, Nan; Li, Wenwen; Yao, Chen; Tang, Houjun

    2017-05-01

    Shifting medium is a kind of metamaterial, which can optically shift a space or an object a certain distance away from its original position. Based on the shifting medium, we propose a concise pair of shifting slabs covering the transmitting or receiving coil in a two-coil wireless power transfer system to decrease the equivalent distance between the coils. The electromagnetic parameters of the shifting slabs are calculated by transformation optics. Numerical simulations validate that the shifting slabs can approximately shift the electromagnetic fields generated by the covered coil; thus, the magnetic coupling and the efficiency of the system are enhanced while remaining the physical transmission distance unchanged. We also verify the advantages of the shifting slabs over the magnetic superlens. Finally, we provide two methods to fabricate shifting slabs based on split-ring resonators.

  11. Evaluating amber force fields using computed NMR chemical shifts.

    Koes, David R; Vries, John K

    2017-10-01

    NMR chemical shifts can be computed from molecular dynamics (MD) simulations using a template matching approach and a library of conformers containing chemical shifts generated from ab initio quantum calculations. This approach has potential utility for evaluating the force fields that underlie these simulations. Imperfections in force fields generate flawed atomic coordinates. Chemical shifts obtained from flawed coordinates have errors that can be traced back to these imperfections. We use this approach to evaluate a series of AMBER force fields that have been refined over the course of two decades (ff94, ff96, ff99SB, ff14SB, ff14ipq, and ff15ipq). For each force field a series of MD simulations are carried out for eight model proteins. The calculated chemical shifts for the 1 H, 15 N, and 13 C a atoms are compared with experimental values. Initial evaluations are based on root mean squared (RMS) errors at the protein level. These results are further refined based on secondary structure and the types of atoms involved in nonbonded interactions. The best chemical shift for identifying force field differences is the shift associated with peptide protons. Examination of the model proteins on a residue by residue basis reveals that force field performance is highly dependent on residue position. Examination of the time course of nonbonded interactions at these sites provides explanations for chemical shift differences at the atomic coordinate level. Results show that the newer ff14ipq and ff15ipq force fields developed with the implicitly polarized charge method perform better than the older force fields. © 2017 Wiley Periodicals, Inc.

  12. Study on the Control Strategy of Shifting Time Involving Multigroup Clutches

    Zhen Zhu

    2016-01-01

    Full Text Available This paper focuses on the control strategy of shifting time involving multigroup clutches for a hydromechanical continuously variable transmission (HMCVT. The dynamic analyses of mathematical models are presented in this paper, and the simulation models are used to study the control strategy of HMCVT. Simulations are performed in Simulation X platform to investigate the shifting time of clutches under different operating conditions. On this basis, simulation analysis and test verification of two typical conditions, which play the decisive roles for the shifting quality, are carried out. The results show that there are differences in the shifting time of the two typical conditions. In the shifting process from the negative transmission of hydromechanical ranges to the positive transmission of hydromechanical ranges, the control strategy based on the shifting time is switching the clutches of shifting mechanism firstly and then disengaging a group of clutches of planetary gear mechanism and engaging another group of the clutches of planetary gear mechanism lastly. In the shifting process from the hydraulic range to the hydromechanical range, the control strategy based on the shifting time is switching the clutches of hydraulic shifting mechanism and planetary gear mechanism at first and then engaging the clutch of shifting mechanism.

  13. The Spectral Web of stationary plasma equilibria. II. Internal modes

    Goedbloed, J. P.

    2018-03-01

    The new method of the Spectral Web to calculate the spectrum of waves and instabilities of plasma equilibria with sizeable flows, developed in the preceding Paper I [Goedbloed, Phys. Plasmas 25, 032109 (2018)], is applied to a collection of classical magnetohydrodynamic instabilities operating in cylindrical plasmas with shear flow or rotation. After a review of the basic concepts of the complementary energy giving the solution path and the conjugate path, which together constitute the Spectral Web, the cylindrical model is presented and the spectral equations are derived. The first example concerns the internal kink instabilities of a cylindrical force-free magnetic field of constant α subjected to a parabolic shear flow profile. The old stability diagram and the associated growth rate calculations for static equilibria are replaced by a new intricate stability diagram and associated complex growth rates for the stationary model. The power of the Spectral Web method is demonstrated by showing that the two associated paths in the complex ω-plane nearly automatically guide to the new class of global Alfvén instabilities of the force-free configuration that would have been very hard to predict by other methods. The second example concerns the Rayleigh-Taylor instability of a rotating theta-pinch. The old literature is revisited and shown to suffer from inconsistencies that are remedied. The most global n = 1 instability and a cluster sequence of more local but much more unstable n =2 ,3 ,…∞ modes are located on separate solution paths in the hydrodynamic (HD) version of the instability, whereas they merge in the MHD version. The Spectral Web offers visual demonstration of the central position the HD flow continuum and of the MHD Alfvén and slow magneto-sonic continua in the respective spectra by connecting the discrete modes in the complex plane by physically meaningful curves towards the continua. The third example concerns the magneto-rotational instability

  14. Magnetic phase shift reconstruction for uniformly magnetized nanowires

    Akhtari-Zavareh, Azadeh [Department of Physics, Simon Fraser University, Burnaby, British Columbia (Canada); De Graef, Marc [Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA (United States); Kavanagh, Karen L. [Department of Physics, Simon Fraser University, Burnaby, British Columbia (Canada)

    2017-01-15

    A new analytical model is developed for the magnetic phase shift of uniformly magnetized nanowires with ideal cylindrical geometry. The model is applied to experimental data from off-axis electron holography measurements of the phase shift of CoFeB nanowires, and the saturation induction of a selected wire, as well as its radius, aspect ratio, position and orientation, is determined by fitting the model parameters. The saturation induction value of 1.7 T of the CoFeB nanowire is found to be similar, to be within the measurement error, to values reported in the literature. - Highlights: • We describe a mathematical model for the magnetic phase shift of a cylindrical nanowire. • We discuss electron holography experiments on magnetic nanowires. • We obtain an accurate fit of the measured magnetic phase shift profile. • We extract the magnetic induction of the nanowire from the phase shift model. • The magnetic induction of 1.7 T agrees well with literature results.

  15. Effect of Shift Work on Nocturia.

    Kim, Jin Wook

    2016-01-01

    To identify the circadian sensitive component of nocturia by comparing nocturia in patients who voluntarily choose a disrupted circadian rhythm, that is, shift workers, with those who maintain normal day-night cycles. Between 2011 and 2013, a total of 1741 untreated patients, 1376 nonshift workers and 365 shift workers, were compared for nocturia indices based on frequency volume charts (FVCs). General linear model of 8-hour interval urine production and frequency were compared between FVCs of nonshift workers, FVCs of night-shift workers, and FVCs of day-shift workers. Nocturia frequency was increased in the night-shift workers (2.38 ± 1.44) compared with nonshift workers (2.18 ± 1.04) (P night-shift workers, 0.34 ± 0.13 for nonshift workers, P = .24), nocturnal bladder capacity index increased significantly (1.41 ± 1.06 for night-shift workers, 1.26 ± 0.92 for nonshift workers, P shift (P shift changes (P = .35). Patients in alternating work shifts showed increased nocturia, especially during their night shift. These changes tended to be more associated with decreased nocturnal bladder capacity than increased nocturnal polyuria. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Berkeley SuperNova Ia Program (BSNIP): Initial Spectral Analysis

    Silverman, Jeffrey; Kong, J.; Ganeshalingam, M.; Li, W.; Filippenko, A. V.

    2011-01-01

    The Berkeley SuperNova Ia Program (BSNIP) has been observing nearby (z analysis of this dataset consists of accurately and robustly measuring the strength and position of various spectral features near maximum brightness. We determine the endpoints, pseudo-continuum, expansion velocity, equivalent width, and depth of each major feature observed in our wavelength range. For objects with multiple spectra near maximum brightness we investigate how these values change with time. From these measurements we also calculate velocity gradients and various flux ratios within a given spectrum which will allow us to explore correlations between spectral and photometric observables. Some possible correlations have been studied previously, but our dataset is unique in how self-consistent the data reduction and spectral feature measurements have been, and it is a factor of a few larger than most earlier studies. We will briefly summarize the contents of the full dataset as an introduction to our initial analysis. Some of our measurements of SN Ia spectral features, along with a few initial results from those measurements, will be presented. Finally, we will comment on our current progress and planned future work. We gratefully acknowledge the financial support of NSF grant AST-0908886, the TABASGO Foundation, and the Marc J. Staley Graduate Fellowship in Astronomy.

  17. Real life working shift assignment problem

    Sze, San-Nah; Kwek, Yeek-Ling; Tiong, Wei-King; Chiew, Kang-Leng

    2017-07-01

    This study concerns about the working shift assignment in an outlet of Supermarket X in Eastern Mall, Kuching. The working shift assignment needs to be solved at least once in every month. Current approval process of working shifts is too troublesome and time-consuming. Furthermore, the management staff cannot have an overview of manpower and working shift schedule. Thus, the aim of this study is to develop working shift assignment simulation and propose a working shift assignment solution. The main objective for this study is to fulfill manpower demand at minimum operation cost. Besides, the day off and meal break policy should be fulfilled accordingly. Demand based heuristic is proposed to assign working shift and the quality of the solution is evaluated by using the real data.

  18. Dynamics and computation in functional shifts

    Namikawa, Jun; Hashimoto, Takashi

    2004-07-01

    We introduce a new type of shift dynamics as an extended model of symbolic dynamics, and investigate the characteristics of shift spaces from the viewpoints of both dynamics and computation. This shift dynamics is called a functional shift, which is defined by a set of bi-infinite sequences of some functions on a set of symbols. To analyse the complexity of functional shifts, we measure them in terms of topological entropy, and locate their languages in the Chomsky hierarchy. Through this study, we argue that considering functional shifts from the viewpoints of both dynamics and computation gives us opposite results about the complexity of systems. We also describe a new class of shift spaces whose languages are not recursively enumerable.

  19. Spectral dimension in causal set quantum gravity

    Eichhorn, Astrid; Mizera, Sebastian

    2014-01-01

    We evaluate the spectral dimension in causal set quantum gravity by simulating random walks on causal sets. In contrast to other approaches to quantum gravity, we find an increasing spectral dimension at small scales. This observation can be connected to the nonlocality of causal set theory that is deeply rooted in its fundamentally Lorentzian nature. Based on its large-scale behaviour, we conjecture that the spectral dimension can serve as a tool to distinguish causal sets that approximate manifolds from those that do not. As a new tool to probe quantum spacetime in different quantum gravity approaches, we introduce a novel dimensional estimator, the causal spectral dimension, based on the meeting probability of two random walkers, which respect the causal structure of the quantum spacetime. We discuss a causal-set example, where the spectral dimension and the causal spectral dimension differ, due to the existence of a preferred foliation. (paper)

  20. Tendon shift in hallux valgus: observations at MR imaging

    Eustace, S. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Williamson, D. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Wilson, M. [Department of Orthopedics, Brigham and Womens Hospital, Boston, Massachusetts (United States); O`Byrne, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Bussolari, L. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Thomas, M. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Stephens, M. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Stack, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Weissman, B. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States)

    1996-08-01

    Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. Results. There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. Conclusion. Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity. (orig.). With 4 figs., 1 tab.