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Sample records for coherent cancellation effect

  1. New coherent cancellation effect involving four-photon excitation and the related ionization

    International Nuclear Information System (INIS)

    Payne, M.G.; Garrett, W.R.; Judish, J.P.; McCann, M.P.

    1988-11-01

    We describe here an effect which occurs when a first laser is tuned near a dipole allowed three-photon resonance and a second laser is used to complete a dipole allowed four-photon resonance between the ground state 0 > and an excited state 2 >. In this process three photons are absorbed from the first laser and one photon from the second; so that if the 0 >--2 > transition is two-photon allowed the transition is also pumped resonantly by the third harmonic field due to the first laser and the second laser field. When the second laser is strong enough to cause strong absorption of the third harmonic light, and the phase mismatch, /DELTA/κ is large and dominated by the nearby resonance, a destructive interference occurs between the pumping of the 0 >--2 > transition by two- and four-photon process. 7 refs

  2. Cancellation Effects in CSR Induced Bunch Transverse Dynamics in Bends

    International Nuclear Information System (INIS)

    Li, R.

    2002-01-01

    The partial cancellation between the effect of centrifugal space charge force on transverse bunch dynamics and the potential energy effect has been a long-standing controversial issue in the study of coherent synchrotron radiation (CSR) induced bunch dynamics in bends. In this paper, we clarify our definition of the ''centrifugal space charge force,'' and discuss the meaning of the ''cancellation effect'' and its general application. We further use simulation to demonstrate the cancellation in both steady state and transient regimes, and show the behavior of the effective transverse force

  3. Effect of the coherent cancellation of the two-photon resonance on the generation of vacuum ultraviolet light by two-photon reasonantly enhanced four-wave mixing

    International Nuclear Information System (INIS)

    Payne, M.G.; Garrett, W.R.; Judish, J.P.; Wunderlich, R.

    1988-11-01

    Many of the most impressive demonstrations of the efficient generation of vacuum ultraviolet (VUV) light have made use of two- photon resonantly enhanced four-wave mixing to generate light at ω/sub VUV/ = 2ω/sub L1/ +- ω/sub L2/. The two-photon resonance state is coupled to the ground state both by two photons from the first laser, or by a photon from the second laser and one from the generated VUV beam. We show here that these two coherent pathways destructively interfere once the second laser is made sufficiently intense, thereby leading to an important limiting effect on the achievable conversion efficiency. 4 refs

  4. 20 CFR 217.27 - Effect of cancellation.

    Science.gov (United States)

    2010-04-01

    ... ANNUITY OR LUMP SUM Cancellation of Application § 217.27 Effect of cancellation. When a person cancels an application the effect is the same as though an application was never filed. When an employee cancels his or her application, any application filed by the employee's spouse is also cancelled. However, a request...

  5. Practical implementation of spectral-intensity dispersion-canceled optical coherence tomography with artifact suppression

    Science.gov (United States)

    Shirai, Tomohiro; Friberg, Ari T.

    2018-04-01

    Dispersion-canceled optical coherence tomography (OCT) based on spectral intensity interferometry was devised as a classical counterpart of quantum OCT to enhance the basic performance of conventional OCT. In this paper, we demonstrate experimentally that an alternative method of realizing this kind of OCT by means of two optical fiber couplers and a single spectrometer is a more practical and reliable option than the existing methods proposed previously. Furthermore, we develop a recipe for reducing multiple artifacts simultaneously on the basis of simple averaging and verify experimentally that it works successfully in the sense that all the artifacts are mitigated effectively and only the true signals carrying structural information about the sample survive.

  6. Force sensing based on coherent quantum noise cancellation in a hybrid optomechanical cavity with squeezed-vacuum injection

    International Nuclear Information System (INIS)

    Motazedifard, Ali; Bemani, F; Naderi, M H; Roknizadeh, R; Vitali, D

    2016-01-01

    We propose and analyse a feasible experimental scheme for a quantum force sensor based on the elimination of backaction noise through coherent quantum noise cancellation (CQNC) in a hybrid atom-cavity optomechanical setup assisted with squeezed vacuum injection. The force detector, which allows for a continuous, broadband detection of weak forces well below the standard quantum limit (SQL), is formed by a single optical cavity simultaneously coupled to a mechanical oscillator and to an ensemble of ultracold atoms. The latter acts as a negative-mass oscillator so that atomic noise exactly cancels the backaction noise from the mechanical oscillator due to destructive quantum interference. Squeezed vacuum injection enforces this cancellation and allows sub-SQL sensitivity to be reached in a very wide frequency band, and at much lower input laser powers. (paper)

  7. Force sensing based on coherent quantum noise cancellation in a hybrid optomechanical cavity with squeezed-vacuum injection

    Science.gov (United States)

    Motazedifard, Ali; Bemani, F.; Naderi, M. H.; Roknizadeh, R.; Vitali, D.

    2016-07-01

    We propose and analyse a feasible experimental scheme for a quantum force sensor based on the elimination of backaction noise through coherent quantum noise cancellation (CQNC) in a hybrid atom-cavity optomechanical setup assisted with squeezed vacuum injection. The force detector, which allows for a continuous, broadband detection of weak forces well below the standard quantum limit (SQL), is formed by a single optical cavity simultaneously coupled to a mechanical oscillator and to an ensemble of ultracold atoms. The latter acts as a negative-mass oscillator so that atomic noise exactly cancels the backaction noise from the mechanical oscillator due to destructive quantum interference. Squeezed vacuum injection enforces this cancellation and allows sub-SQL sensitivity to be reached in a very wide frequency band, and at much lower input laser powers.

  8. PMD compensation in multilevel coded-modulation schemes with coherent detection using BLAST algorithm and iterative polarization cancellation.

    Science.gov (United States)

    Djordjevic, Ivan B; Xu, Lei; Wang, Ting

    2008-09-15

    We present two PMD compensation schemes suitable for use in multilevel (M>or=2) block-coded modulation schemes with coherent detection. The first scheme is based on a BLAST-type polarization-interference cancellation scheme, and the second scheme is based on iterative polarization cancellation. Both schemes use the LDPC codes as channel codes. The proposed PMD compensations schemes are evaluated by employing coded-OFDM and coherent detection. When used in combination with girth-10 LDPC codes those schemes outperform polarization-time coding based OFDM by 1 dB at BER of 10(-9), and provide two times higher spectral efficiency. The proposed schemes perform comparable and are able to compensate even 1200 ps of differential group delay with negligible penalty.

  9. SAR image effects on coherence and coherence estimation.

    Energy Technology Data Exchange (ETDEWEB)

    Bickel, Douglas Lloyd

    2014-01-01

    Radar coherence is an important concept for imaging radar systems such as synthetic aperture radar (SAR). This document quantifies some of the effects in SAR which modify the coherence. Although these effects can disrupt the coherence within a single SAR image, this report will focus on the coherence between separate images, such as for coherent change detection (CCD) processing. There have been other presentations on aspects of this material in the past. The intent of this report is to bring various issues that affect the coherence together in a single report to support radar engineers in making decisions about these matters.

  10. Adaptive cancellation of geomagnetic background noise for magnetic anomaly detection using coherence

    International Nuclear Information System (INIS)

    Liu, Dunge; Xu, Xin; Huang, Chao; Zhu, Wanhua; Liu, Xiaojun; Fang, Guangyou; Yu, Gang

    2015-01-01

    Magnetic anomaly detection (MAD) is an effective method for the detection of ferromagnetic targets against background magnetic fields. Currently, the performance of MAD systems is mainly limited by the background geomagnetic noise. Several techniques have been developed to detect target signatures, such as the synchronous reference subtraction (SRS) method. In this paper, we propose an adaptive coherent noise suppression (ACNS) method. The proposed method is capable of evaluating and detecting weak anomaly signals buried in background geomagnetic noise. Tests with real-world recorded magnetic signals show that the ACNS method can excellently remove the background geomagnetic noise by about 21 dB or more in high background geomagnetic field environments. Additionally, as a general form of the SRS method, the ACNS method offers appreciable advantages over the existing algorithms. Compared to the SRS method, the ACNS algorithm can eliminate the false target signals and represents a noise suppressing capability improvement of 6.4 dB. The positive outcomes in terms of intelligibility make this method a potential candidate for application in MAD systems. (paper)

  11. Coherent beam-beam effect

    International Nuclear Information System (INIS)

    Chao, A.W.; Keil, E.

    1979-06-01

    The stability of the coherent beam-beam effect between rigid bunches is studied analytically and numerically for a linear force by evaluating eigenvalues. For a realistic force, the stability is investigated by following the bunches for many revolutions. 4 refs., 13 figs., 2 tabs

  12. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  13. Coherent cancellation of geometric phase for the OH molecule in external fields

    Science.gov (United States)

    Bhattacharya, M.; Marin, S.; Kleinert, M.

    2014-05-01

    The OH molecule in its ground state presents a versatile platform for precision measurement and quantum information processing. These applications vitally depend on the accurate measurement of transition energies between the OH levels. Significant sources of systematic errors in these measurements are shifts based on the geometric phase arising from the magnetic and electric fields used for manipulating OH. In this article, we present these geometric phases for fields that vary harmonically in time, as in the Ramsey technique. Our calculation of the phases is exact within the description provided by our recent analytic solution of an effective Stark-Zeeman Hamiltonian for the OH ground state. This Hamiltonian has been shown to model experimental data accurately. We find that the OH geometric phases exhibit rich structure as a function of the field rotation rate. Remarkably, we find rotation rates where the geometric phase accumulated by a specific state is zero, or where the relative geometric phase between two states vanishes. We expect these findings to be of importance to precision experiments on OH involving time-varying fields. More specifically, our analysis quantitatively characterizes an important item in the error budget for precision spectroscopy of ground-state OH.

  14. Canceling effect leads temperature insensitivity of hydrolytic enzymes in soil

    Science.gov (United States)

    Razavi, Bahar S.; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    Extracellular enzymes are important for decomposition of many macromolecules abundant in soil such as cellulose, hemicelluloses and proteins (Allison et al., 2010; Chen et al., 2012). The temperature sensitivity of enzymes responsible for organic matter decomposition is the most crucial parameter for prediction of the effects of global warming on carbon cycle. Temperature responses of biological systems are often expressed as a Q10 functions; The Q10 describes how the rate of a chemical reaction changes with a temperature increase for 10 °C The aim of this study was to test how the canceling effect will change with variation in temperature interval, during short-term incubation. We additionally investigated, whether canceling effect occurs in a broad range of concentrations (low to high) and whether it is similar for the set of hydrolytic enzymes within broad range of temperatures. To this end, we performed soil incubation over a temperature range of 0-40°C (with 5°C steps). We determined the activities of three enzymes involved in plant residue decomposition: β-glucosidase and cellobiohydrolase, which are commonly measured as enzymes responsible for degrading cellulose (Chen et al., 2012), and xylanase, which degrades xylooligosaccharides (short xylene chain) in to xylose, thus being responsible for breaking down hemicelluloses (German et al., 2011). Michaelis-Menten kinetics measured at each temperature allowed to calculate Q10 values not only for the whole reaction rates, but specifically for maximal reaction rate (Vmax) and substrate affinity (Km). Subsequently, the canceling effect - simultaneous increase of Vmax and Km with temperature was analyzed within 10 and 5 degree of temperature increase. Three temperature ranges (below 10, between 15 and 25, and above 30 °C) clearly showed non-linear but stepwise increase of temperature sensitivity of all three enzymes and allowed to conclude for predominance of psychrophilic, mesophilic and thermophilic

  15. Strong expectations cancel locality effects: evidence from Hindi.

    Directory of Open Access Journals (Sweden)

    Samar Husain

    Full Text Available Expectation-driven facilitation (Hale, 2001; Levy, 2008 and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005 are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

  16. Strong expectations cancel locality effects: evidence from Hindi.

    Science.gov (United States)

    Husain, Samar; Vasishth, Shravan; Srinivasan, Narayanan

    2014-01-01

    Expectation-driven facilitation (Hale, 2001; Levy, 2008) and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005) are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

  17. Effect of six sigma program on the number of surgeries cancellation.

    Science.gov (United States)

    Gheysari, Esmat; Yousefi, Hojatollah; Soleymani, Hossain; Mojdeh, Soheila

    2016-01-01

    Today, the rate of surgeries is increasing, but surgeries are canceled due to various reasons. Unexpected cancellation of surgeries not only results in disorder in the operating room schedule, but also causes stress for patients and their family and increases costs. We determined the number and causes of surgery cancellations and areas for improvement. This outcome evaluation of Six Sigma program was conducted on 850 cases after the implementation of the program and compared to that of 850 cases which received routine care before the program. Cases were selected through easy sampling during the study. Before the implementation, the number of cancellations was recorded daily and their reasons were investigated. Then, Six Sigma program was implemented in accordance with the reasons for each category and necessary steps were taken to prevent the cancellation of surgeries. Data were collected for 3 months using a three-section data collection form. For data analysis, distribution and relative frequency and chi-square test were used. The three categories of patient, physician, and hospital system were identified as the main causes. The highest rate of cancellation was related to ENT surgeries (74.19%). No cancellations were made in orology surgeries. The implementation of the Six Sigma program caused a significant difference in surgery cancellation (P = 0.003); 31 (3.6%) cases of cancellation were reduced to 12 (1.4%) cases. The results showed that Six Sigma program is a pre-surgery care quality improvement program. Patient education and the implementation of the 6 sigma program can be effective in reducing the rate of cancellation of operations.

  18. Effects of quantum coherence on work statistics

    Science.gov (United States)

    Xu, Bao-Ming; Zou, Jian; Guo, Li-Sha; Kong, Xiang-Mu

    2018-05-01

    In the conventional two-point measurement scheme of quantum thermodynamics, quantum coherence is destroyed by the first measurement. But as we know the coherence really plays an important role in the quantum thermodynamics process, and how to describe the work statistics for a quantum coherent process is still an open question. In this paper, we use the full counting statistics method to investigate the effects of quantum coherence on work statistics. First, we give a general discussion and show that for a quantum coherent process, work statistics is very different from that of the two-point measurement scheme, specifically the average work is increased or decreased and the work fluctuation can be decreased by quantum coherence, which strongly depends on the relative phase, the energy level structure, and the external protocol. Then, we concretely consider a quenched one-dimensional transverse Ising model and show that quantum coherence has a more significant influence on work statistics in the ferromagnetism regime compared with that in the paramagnetism regime, so that due to the presence of quantum coherence the work statistics can exhibit the critical phenomenon even at high temperature.

  19. Canceling effect: a natural mechanism to reduce the effects of global warming

    Science.gov (United States)

    Razavi, Bahar S.; Blagodatskaya, Evgenia; kuzyakov, Yakov

    2016-04-01

    The temperature sensitivity of enzymes responsible for organic matter decomposition in soil is crucial for predicting the effects of global warming on the carbon cycle and sequestration. We tested the hypothesis that differences in temperature sensitivity of enzyme kinetic parameters Vmax and Km will lead to a canceling effect: strong reduction of temperature response of catalytic reactions. Short-term temperature response of Vmax and Km of three hydrolytic enzymes responsible for decomposition of cellulose (β-glucosidase, cellobiohydrolase) and hemicelluloses (xylanase) were analyzed in situ from 0 to 40 °C. The apparent activation energy varied between enzymes from 20.7 to 35.2 kJ mol-1 corresponding to the Q10 values of the enzyme activities of 1.4-1.9 (with Vmax-Q10 1.0-2.5 and Km-Q10 0.94-2.3). Temperature response of all tested enzymes fitted well to the Arrhenius equation. Despite that,the fitting of Arrhenius model revealed the non-linear increase of two cellulolytic enzymes activities with two distinct thresholds at 10-15 °C and 25-30 °C, which were less pronounced for xylanase. The nonlinearity between 10 and 15 °C was explained by 30-80% increase in Vmax. At 25-30 °C, however, the abrupt decrease of enzyme-substrate affinity was responsible for non-linear increase of enzyme activities. Our study is the first demonstrating nonlinear response of Vmax and Km to temperature causing canceling effect, which was most strongly pronounced at low substrate concentrations and at temperatures above 15 °C. Under cold climate, however, the regulation of hydrolytic activity by canceling in response to warming is negligible because canceling was never observed below 10 °C. The canceling, therefore, can be considered as natural mechanism reducing the effects of global warming on decomposition of soil organics at moderate temperatures. The non-linearity of enzyme responses to warming and the respective thresholds should therefore be investigated for other enzymes

  20. Overlapped optics induced perfect coherent effects

    Science.gov (United States)

    Li, Jian Jie; Zang, Xiao Fei; Mao, Jun Fa; Tang, Min; Zhu, Yi Ming; Zhuang, Song Lin

    2013-12-01

    For traditional coherent effects, two separated identical point sources can be interfered with each other only when the optical path difference is integer number of wavelengths, leading to alternate dark and bright fringes for different optical path difference. For hundreds of years, such a perfect coherent condition seems insurmountable. However, in this paper, based on transformation optics, two separated in-phase identical point sources can induce perfect interference with each other without satisfying the traditional coherent condition. This shifting illusion media is realized by inductor-capacitor transmission line network. Theoretical analysis, numerical simulations and experimental results are performed to confirm such a kind of perfect coherent effect and it is found that the total radiation power of multiple elements system can be greatly enhanced. Our investigation may be applicable to National Ignition Facility (NIF), Inertial Confined Fusion (ICF) of China, LED lighting technology, terahertz communication, and so on.

  1. Coherence effects in radiative scattering

    International Nuclear Information System (INIS)

    Knoll, J.; Lenk, R.

    1993-03-01

    The bremsstrahl-production of photons in dense matter is reinvestigated using the example of an exactly solvable quantum mechanical model in one space dimension. Coherence phenomena between successive radiative scatterings among the constituents lead to a modification of the production cross section in the medium relative to the incoherent quasi-free prescription used in kinetic models. Analytic expressions for the correction factor have been derived comparing the quantum rates with the corresponding incoherent quasi-free rates. The result has implications for the kinetic description of all kinds of radiative processes in nucleus-nucleus collisions, both on the level of hadron and parton dynamics. (orig.)

  2. 49 CFR 40.207 - What is the effect of a cancelled drug test?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What is the effect of a cancelled drug test? 40.207 Section 40.207 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Problems in Drug Tests § 40.207 What is the effect of...

  3. Coherence effects in parton showers

    International Nuclear Information System (INIS)

    Pettersson, U.

    1988-10-01

    A model for gluon emission based on the colour dipole approximation is presented. Gluons are radiated from dipoles that are stretched from one colour charge to the corresponding anti-charge, with probability distribution given by generalizations of the Altarelli-Parisi equations. The model agrees very well with experimental data on e + e - annihilation. For the reaction e + e - -> W + W - -> qq ' QQ ' it is pointed out how to extract information about the QCD vacuum and the confinement mechanism by varying the CM energy. Finally the model is applied to deep inelastic lepton scattering. When a quark is kicked out in the lepton-proton interaction, separation of the colour charges leads to gluon emission. Since the proton remnant is not a pointlike object, coherence conditions lead to an asymmetry between gluons emitted in the forward and in the backward region. The asymmetry is controlled by the energy distribution in the force field. Experimental data are reproduced with a linear energy distribution, which is consistent with the proton behaving as a vortex line in a type II superconductor. (author)

  4. 49 CFR 40.273 - What is the effect of a cancelled alcohol test?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What is the effect of a cancelled alcohol test? 40.273 Section 40.273 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Problems in Alcohol Testing § 40.273 What is the...

  5. Partial Cancellation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Partial Cancellation. Full Cancellation is desirable. But complexity requirements are enormous. 4000 tones, 100 Users billions of flops !!! Main Idea: Challenge: To determine which cross-talker to cancel on what “tone” for a given victim. Constraint: Total complexity is ...

  6. Coherence effects in deep inelastic scattering

    International Nuclear Information System (INIS)

    Andersson, B.; Gustafson, G.; Loennblad, L.; Pettersson, U.

    1988-09-01

    We present a framework for deep inelastic scattering, with bound state properties in accordance with a QCD force field acting like a vortex line in a colour superconducting vacuum, which implies some simple coherence effects. Within this scheme one may describe the results of present energies very well, but one obtains an appreciable depletion of gluon radiation in the HERA energy regime. (authors)

  7. The effect of nonlinear forces on coherently oscillating space-charge-dominated beams

    International Nuclear Information System (INIS)

    Celata, C.M.

    1987-03-01

    A particle-in-cell computer simulation code has been used to study the transverse dynamics of nonrelativistic misaligned space-charge-dominated coasting beams in an alternating gradient focusing channel. In the presence of nonlinear forces due to dodecapole or octupole imperfections of the focusing fields or to image forces, the transverse rms emittance grows in a beat pattern. Analysis indicates that this emittance dilution is due to the driving of coherent modes of the beam near their resonant frequencies by the nonlinear force. The effects of the dodecapole and images forces can be made to effectively cancel for some boundary conditions, but the mechanism is not understood at this time

  8. Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect

    International Nuclear Information System (INIS)

    Zhang Fan; Tian Yuan; Zhang Yi; Gu Si-Hong

    2016-01-01

    A pocket coherent population trapping (CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated. Using the differential detecting magneto–optic rotation effect, a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained. The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order, and the ability to detect weak magnetic fields is extended one-fold. Therefore, the proposed scheme is suited to realize a pocket-size CPT magnetometer. (paper)

  9. Compacted cancellous bone has a spring-back effect

    DEFF Research Database (Denmark)

    Kold, S; Bechtold, JE; Ding, Ming

    2003-01-01

    A new surgical technique, compaction, has been shown to improve implant fixation. It has been speculated that the enhanced implant fixation with compaction could be due to a spring-back effect of compacted bone. However, such an effect has yet to be shown. Therefore we investigated in a canine mo....... Thus we found a spring-back effect of compacted bone, which may be important for increasing implant fixation by reducing initial gaps between the implant and bone....

  10. 49 CFR 40.275 - What is the effect of procedural problems that are not sufficient to cancel an alcohol test?

    Science.gov (United States)

    2010-10-01

    ... not sufficient to cancel an alcohol test? 40.275 Section 40.275 Transportation Office of the Secretary... cancel an alcohol test? (a) As an STT, BAT, employer, or a service agent administering the testing... cancelled based on a mistake in the process that does not have a significant adverse effect on the right of...

  11. Cancellation of renormalon ambiguities in the heavy quark effective theory

    International Nuclear Information System (INIS)

    Neubert, M.; Sachrajda, C.T.

    1995-01-01

    Recently, it has been shown that the concept of the pole mass of a heavy quark becomes ambiguous beyond perturbation theory, because of the presence of infrared renormalons. We argue that the predictions of the heavy quark effective theory, whose construction is based on the pole mass, are free of such ambiguities. In the 1/m Q expansion of physical quantities, infrared and ultraviolet renormalons compensate each other between coefficient functions and matrix elements. We trace the appearance of these compensations for current-induced exclusive heavy-to-heavy and heavy-to-light transitions, and for inclusive decays of heavy hadrons. In particular, we show that the structure of the heavy quark expansion is not obscured by renormalons, and none of the predictions of the heavy quark effective theory are invalidated. ((orig.))

  12. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    International Nuclear Information System (INIS)

    Hoffmeister, Brent K; Holt, Andrew P; Kaste, Sue C

    2011-01-01

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  13. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, Brent K; Holt, Andrew P [Department of Physics, Rhodes College, Memphis, TN (United States); Kaste, Sue C, E-mail: hoffmeister@rhodes.edu [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN (United States)

    2011-10-07

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  14. A Novel Hall Effect Sensor Using Elaborate Offset Cancellation Method

    Directory of Open Access Journals (Sweden)

    Vlassis N. Petoussis

    2009-01-01

    Full Text Available The Hall effect is caused by a traverse force that is formed in the electrons or holes of metal element or semiconductor when are polarized by current source and simultaneously all the system it is found vertical in external magnetic field. Result is finally the production of difference of potential (Hall voltage in address vertical in that of current and magnetic field directions. In the present work is presented a new Hall sensor exploiting the former operation. In combination with his pioneering form and using dynamic spinning current technique with an elaborate sequence, it leads to satisfactory results of produced Hall voltage with small noise in a presence of external magnetic field. Anyone can see both the spinning current and anti-Hall technique in the same sensor simultaneously.

  15. Coherence and spin effects in quantum dots

    International Nuclear Information System (INIS)

    Katsumoto, S

    2007-01-01

    This review focuses on experiments on coherent transport through quantum dot systems. The most important quantity obtained in coherent transport is the phase shift through the dots, which gives complementary information to the scattering amplitude (i.e. the conductance). However, two-terminal devices have a particular difficulty, called 'phase rigidity', in obtaining the phase shift. There are two representative ways to avoid this problem: one is to adopt a multi-terminal configuration and another is to use resonance in the interferometer. This review mainly reviews the latter approaches. Such resonance in the whole interferometer often joins with local resonance inside the interferometer and appears as the Fano effect, which is a powerful tool for investigating the phase shift problem with the aid of theories. In addition to such resonances of single-electron states, electron spin causes a kind of many-body resonance, that is, the Kondo effect. Combination of these resonances is the Fano-Kondo effect. Experiments on the Fano-Kondo effect, which unveil the nature of the Kondo resonance, are also reviewed. (topical review)

  16. Combined Effect of Random Transmit Power Control and Inter-Path Interference Cancellation on DS-CDMA Packet Mobile Communications

    Science.gov (United States)

    Kudoh, Eisuke; Ito, Haruki; Wang, Zhisen; Adachi, Fumiyuki

    In mobile communication systems, high speed packet data services are demanded. In the high speed data transmission, throughput degrades severely due to severe inter-path interference (IPI). Recently, we proposed a random transmit power control (TPC) to increase the uplink throughput of DS-CDMA packet mobile communications. In this paper, we apply IPI cancellation in addition to the random TPC. We derive the numerical expression of the received signal-to-interference plus noise power ratio (SINR) and introduce IPI cancellation factor. We also derive the numerical expression of system throughput when IPI is cancelled ideally to compare with the Monte Carlo numerically evaluated system throughput. Then we evaluate, by Monte-Carlo numerical computation method, the combined effect of random TPC and IPI cancellation on the uplink throughput of DS-CDMA packet mobile communications.

  17. The Effective Coherence Length in Anisotropic Superconductors

    International Nuclear Information System (INIS)

    Polturak, E.; Koren, G.; Nesher, O

    1999-01-01

    If electrons are transmitted from a normal conductor(N) into a superconductor(S), common wisdom has it that the electrons are converted into Cooper pairs within a coherence length from the interface. This is true in conventional superconductors with an isotropic order parameter. We have established experimentally that the situation is rather different in high Tc superconductors having an anisotropic order parameter. We used epitaxial thin film S/N bilayers having different interface orientations in order to inject carriers from S into N along different directions. The distance to which these carriers penetrate were determined through their effect on the Tc of the bilayers. We found that the effective coherence length is 20A only along the a or b directions, while in other directions we find a length of 250dr20A out of plane, and an even larger value for in-plane, off high symmetry directions. These observations can be explained using the Blonder-Tinkham-Klapwijk model adapted to anisotropic superconductivity. Several implications of our results on outstanding problems with high Tc junctions will be discussed

  18. Coherent interference effects in SIEM and CBED

    International Nuclear Information System (INIS)

    Cowley, J.M.

    1981-01-01

    The coherent convergent incident beam produced by the field emission gun of a STEM instrument allows the observation of a number of unusual interference effects in the shadow images (SIEM) and convergent beam diffraction (CBED) patterns visible on the detector plane. Shadow images of thin crystals display the electron Ronchigrams having a form sensitive to the defocus and aberrations of the objective lens. For large crystal lattice spacings the Ronchigrams show characteristic ellipses of low contrast. CBED patterns of thin crystal show symmetries and intensities which vary with the position of the incident beam within the unit cell. Discontinuities in the specimen such as the edges of crystals show striking Fresnel diffraction effects in SIEM. In CBED patterns they give rise to the splitting of diffraction spots. If the incident beam is parallel to a smooth face of a small crystal the potential field outside the crystal gives rise to strong refraction effects. (orig.)

  19. The effects of greenbelt cancellation on land value - The case of Wirye New town, South Korea

    Science.gov (United States)

    Lee, S. G.; Yoon, H.

    2017-12-01

    In 1971, South Korean government began designating urban growth boundary around the major cities (total 4,294 in 7 metropolitan areas, and total 809 in 7 small and medium sized urban areas) to control the urban sprawl, spurred by the rapid industrialization and urbanization from the 1960s. However, due to the heated development pressure within the cities, and the recognition of its inefficiency for the original purpose, the growth limit, so-called greenbelt, has been gradually canceled since the late 1990s. In response to this change, real estate market around the greenbelt has been also changed. Extant researches suggest that designating greenbelt causes land scarcity and adds amenity value, driving up land and property price within and approaching to the boundary. On the other hand, cancellation of greenbelt consequently increases developable land and eases the land scarcity, thus can be expected to decrease land value. However, when the canceled greenbelt is to be developed, the price again increases within the boundary, while generating externalities outward. Wirye New Town is one of the government-driven housing developments on repealed greenbelt, to meet the great housing demand of the southern part of Seoul. The site area is 6.8km2 , containing 42,947 housing units, and supplementary infrastructures such as new subway lines and transit malls. Its plan was announced in 2005, and the expected completion is 2017. In 2013, after partial completion, 2,949 apartments began to be occupied. 20,810 housing units have been supplied as of 2015, and 22,137 additional units are going to be provided by 2019. This change has increased average land and housing price of the vicinity by the real demand as well as the real estate speculation. While this alteration of greenbelt has affected adjacent real estate market substantially, study has not been conducted to quantify the impact. In this backdrop, this study aims to analyze the changing externalities effect of greenbelt on

  20. Chiral pair of Fermi arcs, anomaly cancellation, and spin or valley Hall effects in Weyl metals with broken inversion symmetry

    Science.gov (United States)

    Jang, Iksu; Kim, Ki-Seok

    2018-04-01

    Anomaly cancellation has been shown to occur in broken time-reversal symmetry Weyl metals, which explains the existence of a Fermi arc. We extend this result in the case of broken inversion symmetry Weyl metals. Constructing a minimal model that takes a double pair of Weyl points, we demonstrate the anomaly cancellation explicitly. This demonstration explains why a chiral pair of Fermi arcs appear in broken inversion symmetry Weyl metals. In particular, we find that this pair of Fermi arcs gives rise to either "quantized" spin Hall or valley Hall effects, which corresponds to the "quantized" version of the charge Hall effect in broken time-reversal symmetry Weyl metals.

  1. Alien Noise Cancellation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Full FEXT Cancellation. Expectation Maximization based Algorithms. Partial Cancellation. Optimal Choice of what to Cancel and what not to! Alien Noise Cancellation. Efficient Crosstalk channel estimation. In addition:

  2. Anomaly cancellation in effective supergravity theories from the heterotic string: Two simple examples

    Directory of Open Access Journals (Sweden)

    Mary K. Gaillard

    2018-02-01

    Full Text Available We use Pauli–Villars regularization to evaluate the conformal and chiral anomalies in the effective field theories from Z3 and Z7 compactifications of the heterotic string without Wilson lines. We show that parameters for Pauli–Villars chiral multiplets can be chosen in such a way that the anomaly is universal in the sense that its coefficient depends only on a single holomorphic function of the three diagonal moduli. It is therefore possible to cancel the anomaly by a generalization of the four-dimensional Green–Schwarz mechanism. In particular we are able to reproduce the results of a string calculation of the four-dimensional chiral anomaly for these two models.

  3. Anomaly cancellation in effective supergravity theories from the heterotic string: Two simple examples

    Science.gov (United States)

    Gaillard, Mary K.; Leedom, Jacob

    2018-02-01

    We use Pauli-Villars regularization to evaluate the conformal and chiral anomalies in the effective field theories from Z3 and Z7 compactifications of the heterotic string without Wilson lines. We show that parameters for Pauli-Villars chiral multiplets can be chosen in such a way that the anomaly is universal in the sense that its coefficient depends only on a single holomorphic function of the three diagonal moduli. It is therefore possible to cancel the anomaly by a generalization of the four-dimensional Green-Schwarz mechanism. In particular we are able to reproduce the results of a string calculation of the four-dimensional chiral anomaly for these two models.

  4. Pair q-coherent states and their antibunching effects

    International Nuclear Information System (INIS)

    Wang Zhongqing; Li Junhong; An Guanglei; Chongqing Univ. of Posts and Telecommunications, Chongqing

    2005-01-01

    Using the properties of the q-deformed boson creation and annihilation operators and their inverse operators, two kind of q-deformed pair coherent states are introduced. Antibunching effects and correlation properties between two modes in the states are investigated. It is shown that q-deformed pair coherent states exhibit antibunching effects and the photons of the two modes are correlated. These nonclassical effects are influenced by the parameter q. These effects increase when |lnq| increases. (authors)

  5. Coherence effects in atomic impact processes

    International Nuclear Information System (INIS)

    Blum, K.

    1980-01-01

    The author considers excitation of target atoms by projectile particles and the coincident detection of the scattered projectiles and the photons emitted in the subsequent decay by the target atoms. The observation is restricted to radiation emitted by those atoms only which 'scattered' the projectiles with a given energy in a given direction defined by the particle detector. Thus, a certain subensemble of atoms is selected in the experiment. The author reviews the theoretical scheme used for the description of the excited subensemble with the emphasis on the coherence properties. The author reviews developments of the Fano-Macek theory concerning the description of coherently excited states with different angular momenta and parities. A comprehensive expression for the angular distribution of the emitted radiation, including all possible interference terms is given. (Auth.)

  6. Nematodes, exotic earthworms and nitrogen addition: interactions between global change factors lead to cancellation effects.

    Science.gov (United States)

    De Long, Jonathan R

    2017-07-01

    Photos from the experiment described in Shao et al. (): (a) the endogeic (i.e. earthworms that typically live in the soil, burrowing horizontally to acquire nutrients) earthworm Pontoscolex corethrurus that was added to the plots; (b) P. corethrurus in a quiescence state in response to drought; (c) set-up of the control plots (i.e. no earthworms, ambient nitrogen) used in this experiment. [Colour figure can be viewed at wileyonlinelibrary.com] In Focus: Shao, Y., Zhang, W., Eisenhauer, N., Liu, T., Xiong, Y., Liang, C. & Fu, S. (2017) Nitrogen deposition cancels out exotic earthworm effects on plant-feeding nematode communities. Journal of Animal Ecology, 86, 708-717. In this issue of Journal of Animal Ecology, Shao et al. () explored how N addition and exotic earthworms interacted to impact on the plant-feeding nematode community. They demonstrate that exotic earthworm presence alone increased the abundance of less harmful plant-feeding nematodes and decreased the abundance of the more harmful plant-feeding nematodes. However, in plots receiving both exotic earthworms and N addition, such earthworm effects on the nematode community were negated. These findings pull focus on the need to simultaneously consider multiple global change factors (e.g. exotic species invasions and N deposition) when making predictions about how such factors might affect above- and below-ground interactions and thereby alter ecosystem function. © 2017 The Author. Journal of Animal Ecology © 2017 British Ecological Society.

  7. Coherent Synchrotron Radiation effect in damping rings

    International Nuclear Information System (INIS)

    Raubenheimer, T

    2004-01-01

    Coherent Synchrotron Radiation (CSR) can play an important role by not only increasing the energy spread and emittance of a beam, but also leading to a potential instability. Previous studies of the CSR induced longitudinal instability were carried out for the CSR impedance due to dipole magnets. In this paper, the instability due to the CSR impedance from a wiggler is studied assuming a large wiggler parameter K. The primary consideration is a low frequency microwave-like instability in the damping rings of several linear collider projects. The threshold is determined by the instability with the longest possible wavelength

  8. Can the uncertainty appraisal associated with emotion cancel the effect of the hunch period in the Iowa Gambling Task?

    Science.gov (United States)

    Bollon, Thierry; Bagneux, Virginie

    2013-01-01

    Research has given little attention to the influence of incidental emotions on the Iowa Gambling Task (IGT), in which processing of the emotional cues associated with each decision is necessary to make advantageous decisions. Drawing on cognitive theories of emotions, we tested whether uncertainty-associated emotion can cancel the positive effect of the hunch period, by preventing participants from developing a tendency towards advantageous decisions. Our explanation is that uncertainty appraisals initiate deliberative processing that is irrelevant to process emotional cues, contrary to intuitive processing (Kahneman, 2003; Tiedens & Linton, 2001). As expected, uncertainty-associated emotion cancelled the positive effect of the hunch period in the IGT compared to certainty-associated emotion: disgusted participants (certainty-associated emotion) and sad participants induced to feel certainty developed a stronger tendency towards advantageous decisions than sad participants induced to feel uncertainty. We discuss the importance of the core components that trigger incidental emotions to predict decision making.

  9. The role of an effective isotropic tissue modulus in the elastic properties of cancellous bone

    NARCIS (Netherlands)

    Kabel, J.; Rietbergen, van B.; Dalstra, M.; Odgaard, A.; Huiskes, H.W.J.

    1999-01-01

    Conceptually, the elastic characteristics of cancellous bone could be predicted directly from the trabecular morphology-or architecture-and by the elastic properties of the tissue itself. Although hardly any experimental evidence exists, it is often implicitly assumed that tissue anisotropy has a

  10. HUD Initiated Activity Cancellation Reports

    Data.gov (United States)

    Department of Housing and Urban Development — This monthly report displays all HOME activities automatically cancelled by IDIS. Effective January 1, 2011, and the beginning of every month thereafter, committed...

  11. Photovoltaic concepts inspired by coherence effects in photosynthetic systems

    KAUST Repository

    Bredas, Jean-Luc

    2016-12-20

    The past decade has seen rapid advances in our understanding of how coherent and vibronic phenomena in biological photosynthetic systems aid in the efficient transport of energy from light-harvesting antennas to photosynthetic reaction centres. Such coherence effects suggest strategies to increase transport lengths even in the presence of structural disorder. Here we explore how these principles could be exploited in making improved solar cells. We investigate in depth the case of organic materials, systems in which energy and charge transport stand to be improved by overcoming challenges that arise from the effects of static and dynamic disorder-structural and energetic-and from inherently strong electron-vibration couplings. We discuss how solar-cell device architectures can evolve to use coherence-exploiting materials, and we speculate as to the prospects for a coherent energy conversion system. We conclude with a survey of the impacts of coherence and bioinspiration on diverse solar-energy harvesting solutions, including artificial photosynthetic systems.

  12. Modal study of refractive effects on x-ray laser coherence

    International Nuclear Information System (INIS)

    Amendt, P.; London, R.A.; Strauss, M.

    1991-01-01

    The role of smoothly varying transverse gain and refraction profiles on x-ray laser intensity and coherence is analyzed by modally expanding the electric field within the paraxial approximation. Comparison with a square transverse profile reveals that smooth-edged profiles lead to: (1) a greatly reduced number of guided modes, (2) the continued cancellation of local intensity from a loosely guided mode by resonant free modes, (3) and the absence of extraneous (or anomalous) free mode resonances. These generic spectral properties should enable a considerable simplification in analyzing and optimizing the coherence properties of laboratory soft x-ray lasers. 6 refs., 3 figs

  13. Effects of gas produced by degradation of Mg–Zn–Zr Alloy on cancellous bone tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingbo; Jiang, Hongfeng [Tianjin Hospital, 300211 Tianjin (China); Bi, Yanze; Sun, Jin e; Chen, Minfang; Liu, Debao [School of Materials Science and Engineering, Tianjin University of Technology, 300384 Tianjin (China)

    2015-10-01

    Mg–Zn–Zr alloy cylinders were implanted into the femoral condyles of Japanese big-ear white rabbits. X-ray showed that by 12 weeks following implantation the implant became obscure, around which the low-density area appeared and enlarged. By 24 weeks, the implant was more obscure and the density of the surrounding cancellous bone increased. Scanning electron microscopy examination showed bone tissue on the surface of the alloy attached by living fibers at 12 weeks. Micro-CT confirmed that new bone tissue on the surface of the residual alloy implant increased from 12 weeks to 24 weeks. By 12 weeks, many cavities in the cancellous bone tissue around the implant were noted with a CT value, similar to gas value, and increasing by 24 weeks (P < 0.01). Histological examination of hard tissue slices showed that bone tissue was visibly attached to the alloy in the femoral condyle at 12 weeks. The trabecular bone tissues became more intact and dense, and the cavities were filled with soft tissue at 24 weeks. In general, gas produced by the degradation of the Mg–Zn–Zr alloy can cause cavitation within cancellous bone, which does not affect osteogenesis of Mg alloy. - Highlights: • The degradation of Mg alloy in cancellous bone causes cavitation around the alloy. • At first, the CT value of the cavities is similar to the gas value. • The area of the cavities enlarges gradually by 12 weeks. • The cavities are filled with bone tissue and soft tissue gradually.

  14. Narrow coherent effects in πNN-dynamics

    International Nuclear Information System (INIS)

    Kudryavtsev, A.E.; Obrant, G.Z.

    1990-01-01

    Coherent effect production is considered in πNN-dynamics with resonant pion-nucleon interaction via Brueckner theory and Faddev equations. It is shown that the narrow energy and final momentum dependence can arise in the inelastic S-wave πd-scattering. The energy dependence peculiarities can have a width an order magnitude less than πN-resonance one

  15. Effect of yogic breathing on accommodate braille version of six-letter cancellation test in students with visual impairment

    Directory of Open Access Journals (Sweden)

    Balaram Pradhan

    2018-01-01

    Full Text Available Context: Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT was used for students with visual impairment (VI. Aim: This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr and breath awareness (BA on students with VI. Methods: This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females, with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari; on the 2nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. Results: The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days (P < 0.001. BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA (P < 0.05, but the increase in the score after Bhramari was not significant. Conclusions: Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied.

  16. Effect of Yogic Breathing on Accommodate Braille Version of Six-letter Cancellation Test in Students with Visual Impairment.

    Science.gov (United States)

    Pradhan, Balaram; Mohanty, Soubhagyalaxmi; Hankey, Alex

    2018-01-01

    Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT) was used for students with visual impairment (VI). This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr) and breath awareness (BA) on students with VI. This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females), with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1 st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari ; on the 2 nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days ( P < 0.001). BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA ( P < 0.05), but the increase in the score after Bhramari was not significant. Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied.

  17. EFFECTS OF LIGHT WAVELENGTHS AND COHERENCE ON BASIDIOSPORES GERMINATION

    Directory of Open Access Journals (Sweden)

    Natalia Poyedinok

    2015-02-01

    Full Text Available The effects of light wavelengths and coherence on basidiospore germination of Agaricus bisporus, Flammulina velutipes, Ganoderma applanatum, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes and Pleurotus ostreatus have been studied. Short-term low-intensity irradiation by coherent (laser light wavelength 488.0 nm and 632.8 nm at doses 45 and 230 mJ/cm2 has significantly increased the number of germinated basidiospores. It has established that there are differences in the photosensitivity not only between species but also between strains. Spores irradiation by 514.5 nm light has been either neutral or inhibitory. A comparative analysis of basidiospores sensitivity to laser and LED light has also been conducted. To stimulate germination of basidiospores and growth of monokaryons the most suitable solution was to use red coherent and incoherent light of 632.8 nm and 660,0 nm for A. bisporus, G. applanatum and P. ostreatus, red and blue coherent light of 632.8 nm and 488,0 nm for F. velutipes, and both red and blue laser and LED light G. lucidum and H. erinaceus and for L. edodes. No essential difference of a continuous wave mode and intermittent mode light effect at the same doses and wavelength on spore germination were revealed. Light influence has reduced germination time and formation of aerial mycelium on agar medium as compared to the original value and increased the growth rate of monosporous isolates. Characterization of basidiospores photosensitivity and development of environmentally friendly stimulating methods of their germination is important for creating highly effective technologies of mushrooms selection and cultivation.

  18. Channeling and coherent bremsstrahlung effects for relativistic positrons and electrons

    International Nuclear Information System (INIS)

    Walker, R.L.

    1976-01-01

    Channeling of positrons in single crystals of silicon was observed in transmission and scattering measurements for incident energies from 16 to 28 MeV. In addition, the spectral dependence upon crystal orientation of the forward coherent bremsstrahlung produced by beams of 28-MeV positrons and electrons incident upon a 5 μm thick single crystal of silicon was measured with a NaI photon spectrometer. Effects of channeling and perhaps of the nonvalidity of the first Born approximation were observed for beam directions near the [111] axis of the crystal, and coherent peaks near 0.5 MeV were observed for a compound interference direction, in agreement with first-order theoretical calculations. 32 fig

  19. Effects of Coherence and Relevance on Shallow and Deep Text Processing.

    Science.gov (United States)

    Lehman, Stephen; Schraw, Gregory

    2002-01-01

    Examines the effects of coherence and relevance on shallow and deeper text processing, testing the hypothesis that enhancing the relevance of text segments compensates for breaks in local and global coherence. Results reveal that breaks in local coherence had no effect on any outcome measures, whereas relevance enhanced deeper processing.…

  20. The effect of losses on the quantum-noise cancellation in the SU(1,1) interferometer

    International Nuclear Information System (INIS)

    Xin, Jun; Wang, Hailong; Jing, Jietai

    2016-01-01

    Quantum-noise cancellation (QNC) is an effective method to control the noise of the quantum system, which reduces or even eliminates the noise of the quantum systems by utilizing destructive interference in the quantum system. However, QNC can be extremely dependent on the losses inside the system. In this letter, we experimentally and theoretically study how the losses can affect the QNC in the SU(1,1) interferometer. We find that losses in the different arms inside the SU(1,1) interferometer can have different effects on the QNC in the output fields from the SU(1,1) interferometer. And the QNC in the SU(1,1) interferometer can almost be insensitive to the losses in some cases. Our findings may find its potential applications in the quantum noise control.

  1. The effect of losses on the quantum-noise cancellation in the SU(1,1) interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Jun; Wang, Hailong [State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200062 (China); Jing, Jietai, E-mail: jtjing@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200062 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2016-08-01

    Quantum-noise cancellation (QNC) is an effective method to control the noise of the quantum system, which reduces or even eliminates the noise of the quantum systems by utilizing destructive interference in the quantum system. However, QNC can be extremely dependent on the losses inside the system. In this letter, we experimentally and theoretically study how the losses can affect the QNC in the SU(1,1) interferometer. We find that losses in the different arms inside the SU(1,1) interferometer can have different effects on the QNC in the output fields from the SU(1,1) interferometer. And the QNC in the SU(1,1) interferometer can almost be insensitive to the losses in some cases. Our findings may find its potential applications in the quantum noise control.

  2. Charge carrier coherence and Hall effect in organic semiconductors

    Science.gov (United States)

    Yi, H. T.; Gartstein, Y. N.; Podzorov, V.

    2016-01-01

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor. PMID:27025354

  3. Charge carrier coherence and Hall effect in organic semiconductors.

    Science.gov (United States)

    Yi, H T; Gartstein, Y N; Podzorov, V

    2016-03-30

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force acting on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.

  4. Effects of Coupling Distance on Synchronization and Coherence in Chaotic Neural Networks

    International Nuclear Information System (INIS)

    Wang Maosheng

    2009-01-01

    Effects of coupling distance on synchronization and coherence of chaotic neurons in complex networks are numerically investigated. We find that it is not beneficial to neurons synchronization if confining the coupling distance of random edges to a limit d max , but help to improve their coherence. Moreover, there is an optimal value of d max at which the coherence is maximum.

  5. The size effect of the quantum coherence in the transverse-field XY chain

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu; Yang, Cui-hong; Wang, Jun-feng [Department of Physics, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Lei, Shu-guo, E-mail: sglei@njtech.edu.cn [College of Science, Nanjing Tech University, Nanjing, 211816 (China)

    2016-12-15

    Based on the Wigner–Yanase skew information, the size effect of the quantum coherence in the ground state of the finite transverse-field spin-1/2 XY chain is explored. It is found that the first-order derivatives of the single-spin coherence and the two-spin local coherence both have scaling behaviors in the vicinity of the critical point. A simplified version of coherence is also studied and the same characteristics with its counterpart are found.

  6. Imperfect generalized transmit beamforming with co-channel interference cancelation

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

    2010-01-01

    of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact

  7. Effects of vitamin K2 on cortical and cancellous bone mass, cortical osteocyte and lacunar system, and porosity in sciatic neurectomized rats.

    Science.gov (United States)

    Iwamoto, Jun; Matsumoto, Hideo; Takeda, Tsuyoshi; Sato, Yoshihiro; Yeh, James K

    2010-09-01

    The purpose of the present study was to examine the effects of vitamin K2 on cortical and cancellous bone mass, cortical osteocyte and lacunar system, and porosity in sciatic neurectomized rats. Thirty-four female Sprague-Dawley retired breeder rats were randomized into three groups: age-matched control, sciatic neurectomy (NX), and NX + vitamin K2 administration (menatetrenone, 30 mg/kg/day p.o., three times a week). At the end of the 8-week experiment, bone histomorphometric analysis was performed on cortical and cancellous bone of the tibial diaphysis and proximal metaphysis, respectively, and osteocyte lacunar system and porosity were evaluated on cortical bone of the tibial diaphysis. NX decreased cortical and cancellous bone mass compared with age-matched controls as a result of increased endocortical and trabecular bone erosion and decreased trabecular mineral apposition rate (MAR). Vitamin K2 ameliorated the NX-induced increase in bone erosion, prevented the NX-induced decrease in MAR, and increased bone formation rate (BFR/bone surface) in cancellous bone, resulting in an attenuation of NX-induced cancellous bone loss. However, vitamin K2 did not significantly influence cortical bone mass. NX also decreased osteocyte density and lacunar occupancy and increased porosity in cortical bone compared with age-matched controls. Vitamin K2 ameliorated the NX-induced decrease in lacunar occupancy by viable osteocytes and the NX-induced increase in porosity. The present study showed the efficacy of vitamin K2 for cancellous bone mass and cortical lacunar occupancy by viable osteocytes and porosity in sciatic NX rats.

  8. Array-Enhanced Coherence Resonance: Nontrivial Effects of Heterogeneity and Spatial Independence of Noise

    International Nuclear Information System (INIS)

    Zhou, Changsong; Kurths, Juergen; Hu, Bambi

    2001-01-01

    We demonstrate the effect of coherence resonance in a heterogeneous array of coupled Fitz Hugh--Nagumo neurons. It is shown that coupling of such elements leads to a significantly stronger coherence compared to that of a single element. We report nontrivial effects of parameter heterogeneity and spatial independence of noise on array-enhanced coherence resonance; especially, we find that (i) the coherence increases as spatial correlation of the noise decreases, and (ii) inhomogeneity in the parameters of the array enhances the coherence. Our results have the implication that generic heterogeneity and background noise can play a constructive role to enhance the time precision of firing in neural systems

  9. Low-frequency stimulation cancels the high-frequency-induced long-lasting effects in the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Pettorossi, V E; Zampolini, M

    1996-05-15

    In rat brainstem slices, we investigated the effects of low-frequency stimulation (LFS) of the primary vestibular afferents on the amplitude of the field potentials evoked in the medial vestibular nuclei (MVN). LFS induced long-term effects, the sign of which depended on whether the vestibular neurons were previously conditioned by HFS. In unconditioned slices, LFS evoked modifications of the responses that were similar to those observed after HFS but had a smaller extension. In fact, LFS caused long-lasting potentiation of the N1 wave in the MVN ventral portion (Vp) and long-lasting depression of the N2 wave in the MVN dorsal portion (Dp), whereas it provoked small and variable effects on the N1 wave. By contrast, when the synaptic transmission was already conditioned, LFS influenced the synaptic responses oppositely, reducing or annulling the HFS long-term effects. This phenomenon was specifically induced by LFS, because HFS was not able to cause it. The involvement of NMDA receptors in mediating the LFS long-term effects was supported by the fact that AP-5 prevented their induction. In addition, the annulment of HFS long-term effects by LFS was also demonstrated by the shift in the latency of the evoked unitary potentials after LFS. In conclusion, we suggest that the reduction of the previously induced conditioning could represent a cancellation mechanism, useful to quickly adapt the vestibular system to continuous different needs and to avoid saturation.

  10. Late Effects of Heavy Ion Irradiation on Ex Vivo Osteoblastogenesis and Cancellous Bone Microarchitecture

    Science.gov (United States)

    Tran, Luan Hoang; Alwood, Joshua; Kumar, Akhilesh; Limoli, C. L.; Globus, Ruth

    2012-01-01

    . Thus, both low and high doses of heavy ion irradiation cause time dependent, adaptive changes in redox state within marrow cells but only high doses (50, 200cGy) inhibit osteoblastogenesis and cause cancellous bone loss. We conclude space radiation has the potential to cause persistent damage to bone marrow derived stem and progenitor cells for osteoblasts despite adaptive changes in cellular redox state.

  11. Nuclear plant cancellations: causes, costs, and consequences

    International Nuclear Information System (INIS)

    1983-04-01

    This study was commissioned in order to help quantify the effects of nuclear plant cancellations on the Nation's electricity prices. This report presents a historical overview of nuclear plant cancellations through 1982, the costs associated with those cancellations, and the reasons that the projects were terminated. A survey is presented of the precedents for regulatory treatment of the costs, the specific methods of cost recovery that were adopted, and the impacts of these decisions upon ratepayers, utility stockholders, and taxpayers. Finally, the report identifies a series of other nuclear plants that remain at risk of canellation in the future, principally as a result of similar demand, finance, or regulatory problems cited as causes of cancellation in the past. The costs associated with these potential cancellations are estimated, along with their regional distributions, and likely methods of cost recovery are suggested

  12. Electron bunch compression and coherent effects at the SDL

    International Nuclear Information System (INIS)

    Loos, Henrik; Carr, G. Lawrence; Doyuran, Adnan; Graves, William S.; Johnson, Eric D.; Krinsky, Samuel; Rose, James; Sheehy, Brian; Shaftan, Timur V.; Skaritka, John; Yu Lihua

    2002-01-01

    The DUVFEL accelerator in the Source Development Lab of NSLS/BNL generates a high brightness electron beam from a laser driven electron source and a magnetic bunch compressor. This beam is used for different FEL experiments in SASE and future HGHG configurations. The compression of the electron beam to high peak current while preserving the transverse properties is of great importance to the performance goals of these FELs. In this paper we report on the experimental methods to characterize the longitudinal properties of the electron beam and the measured results for various settings of the DUVFEL accelerator. The observed effects on the electron beam spectra and time profiles during compression are most likely due to coherent effects while their exact origin is still subject of ongoing investigation

  13. The effect on recognition memory of noise cancelling headphones in a noisy environment with native and nonnative speakers

    Directory of Open Access Journals (Sweden)

    Brett R C Molesworth

    2014-01-01

    Full Text Available Noise has the potential to impair cognitive performance. For nonnative speakers, the effect of noise on performance is more severe than their native counterparts. What remains unknown is the effectiveness of countermeasures such as noise attenuating devices in such circumstances. Therefore, the main aim of the present research was to examine the effectiveness of active noise attenuating countermeasures in the presence of simulated aircraft noise for both native and nonnative English speakers. Thirty-two participants, half native English speakers and half native German speakers completed four recognition (cued recall tasks presented in English under four different audio conditions, all in the presence of simulated aircraft noise. The results of the research indicated that in simulated aircraft noise at 65 dB(A, performance of nonnative English speakers was poorer than for native English speakers. The beneficial effects of noise cancelling headphones in improving the signal to noise ratio led to an improved performance for nonnative speakers. These results have particular importance for organizations operating in a safety-critical environment such as aviation.

  14. Compensating effect of the coherent synchrotron radiation in bunch compressors

    Science.gov (United States)

    Jing, Yichao; Hao, Yue; Litvinenko, Vladimir N.

    2013-06-01

    Typical bunch compression for a high-gain free-electron laser (FEL) requires a large compression ratio. Frequently, this compression is distributed in multiple stages along the beam transport line. However, for a high-gain FEL driven by an energy recovery linac (ERL), compression must be accomplished in a single strong compressor located at the beam line’s end; otherwise the electron beam would be affected severely by coherent synchrotron radiation (CSR) in the ERL’s arcs. In such a scheme, the CSR originating from the strong compressors could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressor that will limit the effect of CSR on the e-beam’s quality. We discuss our findings from a study of such a compressor, and detail its potential for an FEL driven by a multipass ERL developed for the electron-Relativistic Heavy Ion Collider.

  15. Relativity effects for space-based coherent lidar experiments

    Science.gov (United States)

    Gudimetla, V. S. Rao

    1996-01-01

    An effort was initiated last year in the Astrionics Laboratory at Marshall Space Flight Center to examine and incorporate, if necessary, the effects of relativity in the design of space-based lidar systems. A space-based lidar system, named AEOLUS, is under development at Marshall Space Flight Center and it will be used to accurately measure atmospheric wind profiles. Effects of relativity were also observed in the performance of space-based systems, for example in case of global positioning systems, and corrections were incorporated into the design of instruments. During the last summer, the effects of special relativity on the design of space-based lidar systems were studied in detail, by analyzing the problem of laser scattering off a fixed target when the source and a co-located receiver are moving on a spacecraft. Since the proposed lidar system uses a coherent detection system, errors even in the order of a few microradians must be corrected to achieve a good signal-to-noise ratio. Previous analysis assumed that the ground is flat and the spacecraft is moving parallel to the ground, and developed analytical expressions for the location, direction and Doppler shift of the returning radiation. Because of the assumptions used in that analysis, only special relativity effects were involved. In this report, that analysis is extended to include general relativity and calculate its effects on the design.

  16. Effect of light assisted collisions on matter wave coherence in superradiant Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Kampel, Nir Shlomo; Griesmaier, Axel Rudolf; Steenstrup, Mads Peter Hornbak

    2012-01-01

    We investigate experimentally the effects of light assisted collisions on the coherence between momentum states in Bose-Einstein condensates. The onset of superradiant Rayleigh scattering serves as a sensitive monitor for matter-wave coherence. A subtle interplay of binary and collective effects...

  17. Scientific journal cancellations

    CERN Multimedia

    The Library

    2001-01-01

    Earlier this year the Scientific Information Policy Board (SIPB) requested the Library and the Working Group for Acquisitions to revise the current printed journal collection in order to cancel those titles that are less required. Savings could then be used for the development of other collections and particularly electronic resources needed to support CERN current research activities. A list of proposed cancellations was drawn and posted on the Library web pages: http://library.cern.ch/library_general/cancel.html The SIPB invites every one to check if any of the titles are of importance to their work, in which case you are invited to inform the Library before the 25th of September by sending an e-mail to: eliane.chaney@cern.ch Titles not reconsidered by the users will be cancelled by the end of the year. Thank you, The Library

  18. Copper interacts with nonylphenol to cancel the effect of nonylphenol on fish chemosensory behaviour.

    Science.gov (United States)

    Ward, Ashley J W; Thistle, Maria; Ghandi, Khashayar; Currie, Suzanne

    2013-10-15

    The majority of ecotoxicological studies have been concerned with responses of organisms to a single contaminant. While this approach remains valid, the challenge now is to understand the way in which multiple contaminants and stressors interact to produce effects in study organisms. Here we take an integrated biological and physico-chemical approach to understand the effects of 4-nonylphenol and copper on fish (white perch, Morone americana) chemosensory behaviour. We show that a one hour exposure to 2 μg L(-1) nonylphenol removes chemosensory attraction to conspecific chemical cues, while exposure to 5 μg L(-1) copper for one hour had no significant effect on the fish's attraction to these cues. Further, we show that simultaneous exposure to both contaminants at the stated dosage and for the same duration has no significant effect on the chemosensory attraction of white perch to conspecific chemical cues suggesting that copper mediates the effect of nonylphenol on fish in this respect. Physico-chemical data show that copper ions bind to nonylphenol in water, providing a mechanistic explanation for this change in the effect of nonylphenol. Furthermore, the finding that the copper ions bind to the lone pair of O on the nonylphenol molecule offers the tantalising possibility that it is this region of the nonylphenol molecule that plays the key role in disrupting fish chemical communication. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Summation and Cancellation Effects on QRS and ST-Segment Changes Induced by Simultaneous Regional Myocardial Ischemia.

    Science.gov (United States)

    Vives-Borrás, Miquel; Jorge, Esther; Amorós-Figueras, Gerard; Millán, Xavier; Arzamendi, Dabit; Cinca, Juan

    2018-01-01

    Simultaneous ischemia in two myocardial regions is a potentially lethal clinical condition often unrecognized whose corresponding electrocardiographic (ECG) patterns have not yet been characterized. Thus, this study aimed to determine the QRS complex and ST-segment changes induced by concurrent ischemia in different myocardial regions elicited by combined double occlusion of the three main coronary arteries. For this purpose, 12 swine were randomized to combination of 5-min single and double coronary artery occlusion: Group 1: left Circumflex (LCX) and right (RCA) coronary arteries ( n = 4); Group 2: left anterior descending artery (LAD) and LCX ( n = 4) and; Group 3: LAD and RCA ( n = 4). QRS duration and ST-segment displacement were measured in 15-lead ECG. As compared with single occlusion, double LCX+RCA blockade induced significant QRS widening of about 40 ms in nearly all ECG leads and magnification of the ST-segment depression in leads V1-V3 (maximal 228% in lead V3, p ST-segment elevation in precordial leads (maximal attenuation of 60% in lead V3 in LAD+LCX and 86% in lead V5 in LAD+RCA, p ST-segment elevation in leads V7-V9 was a specific sign of single LCX occlusion. In conclusion, concurrent infero-lateral ischemia was associated with a marked summation effect of the ECG changes previously elicited by each single ischemic region. By contrast, a cancellation effect on ST-segment changes with no QRS widening was observed when the left anterior descending artery was involved.

  20. Credit cycle coherence in the eurozone : Was there a euro effect?

    NARCIS (Netherlands)

    Samarina, Anna; Zhang, Lu; Bezemer, Dirk

    2017-01-01

    This paper examines effects of the euro introduction on credit cycle coherence in the euro-zone through six channels. We construct and describe credit cycles for total bank credit, household mortgages and non-financial business loans for 16 EMU economies over 1990-2015. Credit cycle coherence is

  1. Current source enhancements in Electrical Impedance Spectroscopy (EIS) to cancel unwanted capacitive effects

    Science.gov (United States)

    Zarafshani, Ali; Bach, Thomas; Chatwin, Chris; Xiang, Liangzhong; Zheng, Bin

    2017-03-01

    Electrical Impedance Spectroscopy (EIS) has emerged as a non-invasive imaging modality to detect and quantify functional or electrical properties related to the suspicious tumors in cancer screening, diagnosis and prognosis assessment. A constraint on EIS systems is that the current excitation system suffers from the effects of stray capacitance having a major impact on the hardware subsystem as the EIS is an ill-posed inverse problem which depends on the noise level in EIS measured data and regularization parameter in the reconstruction algorithm. There is high complexity in the design of stable current sources, with stray capacitance reducing the output impedance and bandwidth of the system. To confront this, we have designed an EIS current source which eliminates the effect of stray capacitance and other impacts of the capacitance via a variable inductance. In this paper, we present a combination of operational CCII based on a generalized impedance converter (OCCII-GIC) with a current source. The aim of this study is to use the EIS system as a biomedical imaging technique, which is effective in the early detection of breast cancer. This article begins with the theoretical description of the EIS structure, current source topologies and proposes a current conveyor in application of a Gyrator to eliminate the current source limitations and its development followed by simulation and experimental results. We demonstrated that the new design could achieve a high output impedance over a 3MHz frequency bandwidth when compared to other types of GIC circuits combined with an improved Howland topology.

  2. Adapting to an initial self-regulatory task cancels the ego depletion effect.

    Science.gov (United States)

    Dang, Junhua; Dewitte, Siegfried; Mao, Lihua; Xiao, Shanshan; Shi, Yucai

    2013-09-01

    The resource-based model of self-regulation provides a pessimistic view of self-regulation that people are destined to lose their self-control after having engaged in any act of self-regulation because these acts deplete the limited resource that people need for successful self-regulation. The cognitive control theory, however, offers an alternative explanation and suggests that the depletion effect reflects switch costs between different cognitive control processes recruited to deal with demanding tasks. This account implies that the depletion effect will not occur once people have had the opportunity to adapt to the self-regulatory task initially engaged in. Consistent with this idea, the present study showed that engaging in a demanding task led to performance deficits on a subsequent self-regulatory task (i.e. the depletion effect) only when the initial demanding task was relatively short but not when it was long enough for participants to adapt. Our results were unrelated to self-efficacy, mood, and motivation. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Coordinate and Kaehler σ-model anomalies and their cancellation in string effective field theories

    International Nuclear Information System (INIS)

    Lopes Cardoso, G.; Ovrut, B.A.

    1993-01-01

    We discuss the complete set of one-loop triangle graphs involving the Yang-Mills gauge connection, the Kaehler connection and the σ-model coordinate connection in the effective field theory of (2, 2) symmetric Z N orbifolds. That is, we discuss pure gauge, pure Kaehler and pure σ-model coordinate anomalies as well as the mixed anomalies, such as Kaehler-gauge, some of which have been discussed elsewhere. We propose a mechanism for restoring both Kaehler and σ-model coordinate symmetry based upon the introduction of two types of counterterms. Finally, we enlarge σ-model generalization of the Green-Schwarz mechanism to allow the removal of the universal parts of a wider class of anomalies than those previously discussed. (orig.)

  4. 75 FR 54147 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2010-09-03

    ... cancellation is effective September 3, 2010. FOR FURTHER INFORMATION CONTACT: Leonard Cole, Biopesticides and... 23, 2010. W. Michael McDavit. Acting Director, Biopesticides and Pollution Prevention Division...

  5. Effect of quantum lattice fluctuations on quantum coherent oscillations in a coherently driven quantum dot-cavity system

    International Nuclear Information System (INIS)

    Zhu, Ka-Di; Li, Wai-Sang

    2003-01-01

    The quantum coherent oscillations in a coherently driven quantum dot-cavity system with the presence of strong exciton-phonon interactions are investigated theoretically in a fully quantum treatment. It is shown that even at zero temperature, the strong exciton-phonon interactions still affect the quantum coherent oscillations significantly

  6. Coherence and interlimb force control: Effects of visual gain.

    Science.gov (United States)

    Kang, Nyeonju; Cauraugh, James H

    2018-03-06

    Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. A proof of the cancellation of the redistribution tidal potential effects on the rotation of an elastic Earth model

    Science.gov (United States)

    Baenas, Tomás; Escapa, Alberto; Ferrándiz, Jose Manuel

    2014-05-01

    The gravitational action of the Moon and the Sun on the elastic Earth originates a redistribution of its mass. In turn, this redistribution is responsible of an additional term in the gravitational potential energy of the system, commonly referred to as tidal potential of redistribution. Its effects on the Earth rotation were previously discussed in Escapa et al. (2004) and Lambert & Mathews (2006). A numerical approach was followed in those works to show that for an elastic Earth model, assumed to be spherical and non-rotating in the undeformed state, there is no net contribution to the motion of the figure axis. This result is consistent with the corresponding one deduced from the torque approach, where one can derive analytically that the redistribution torque for that elastic Earth model vanishes (e.g., Krasinsky 1999). However, it is far from being a trivial question to recover the same result when working directly with the tidal potential of redistribution, as in Escapa et al. (2004) or Lambert & Mathews (2006). In this investigation we revisit the issue, enhancing and completing former results by Escapa et al. (2004). In particular, we aim at proving, by analytical means, that the redistribution tidal potential of the former elastic Earth model does not affect its rotational motion. To this end we expand that potential in terms of an Andoyer-like set of canonical variables, and then compute the torque associated to it. This choice was motivated by the suitability of this set of variables to extend our calculations to the nutations of other different elastic or anelastic Earth models, through the Hamiltonian framework (e.g., Ferrándiz et al. 2012). We show the exact cancellation of the derived expressions as a consequence of certain properties fulfilled by the expansions of the orbital motion of the perturbing bodies. Acknowledgement. - This work has been partially supported by the Spanish government trhough the MINECO projects I+D+I AYA201022039-C02-01, AYA

  8. Dose and dose rate effects on coherent-to-incoherent transition of precipitates upon irradiation

    Institute of Scientific and Technical Information of China (English)

    LI Zhengchao

    2006-01-01

    A typical precipitation hardened alloy, Cu-Co dilute alloy was selected to study the precipitation behavior and irradiation effect on precipitates. It is found that the principal effect of ion irradiation on the coherent precipitates is loss of coherency, and TEM cross-section observations show that the fraction of the incoherent precipitates is dependent on dose but not on dose rate during heavy ion irradiation.

  9. Self-consistency and coherent effects in nonlinear resonances

    International Nuclear Information System (INIS)

    Hofmann, I.; Franchetti, G.; Qiang, J.; Ryne, R. D.

    2003-01-01

    The influence of space charge on emittance growth is studied in simulations of a coasting beam exposed to a strong octupolar perturbation in an otherwise linear lattice, and under stationary parameters. We explore the importance of self-consistency by comparing results with a non-self-consistent model, where the space charge electric field is kept 'frozen-in' to its initial values. For Gaussian distribution functions we find that the 'frozen-in' model results in a good approximation of the self-consistent model, hence coherent response is practically absent and the emittance growth is self-limiting due to space charge de-tuning. For KV or waterbag distributions, instead, strong coherent response is found, which we explain in terms of absence of Landau damping

  10. Laser excitation of SF6: spectroscopy and coherent pulse propagation effects

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Makarov, A.A.; Louisell, W.H.

    1978-01-01

    Recent theoretical studies of coherent propagation effects in SF 6 and other polyatomic molecules are summarized beginning with an account of relevant aspects of the high-resolution spectroscopy of the ν 3 band of SF 6 . A laser pulse propagating in a molecular gas can acquire new frequencies which were not initially present in the pulse, and, in fact, a wave is coherently generated at the frequency of every molecular transition accessible from the initial molecular energy levels. The possible consequences of coherent generation of sidebands for the multiple-photon excitation of SF 6 and other polyatomic molecules are discussed

  11. Coherent detectors

    International Nuclear Information System (INIS)

    Lawrence, C R; Church, S; Gaier, T; Lai, R; Ruf, C; Wollack, E

    2009-01-01

    Coherent systems offer significant advantages in simplicity, testability, control of systematics, and cost. Although quantum noise sets the fundamental limit to their performance at high frequencies, recent breakthroughs suggest that near-quantum-limited noise up to 150 or even 200 GHz could be realized within a few years. If the demands of component separation can be met with frequencies below 200 GHz, coherent systems will be strong competitors for a space CMB polarization mission. The rapid development of digital correlator capability now makes space interferometers with many hundreds of elements possible. Given the advantages of coherent interferometers in suppressing systematic effects, such systems deserve serious study.

  12. Coherent detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, C R [M/C 169-327, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Church, S [Room 324 Varian Physics Bldg, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States); Gaier, T [M/C 168-314, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Lai, R [Northrop Grumman Corporation, Redondo Beach, CA 90278 (United States); Ruf, C [1533 Space Research Building, The University of Michigan, Ann Arbor, MI 48109-2143 (United States); Wollack, E, E-mail: charles.lawrence@jpl.nasa.go [NASA/GSFC, Code 665, Observational Cosmology Laboratory, Greenbelt, MD 20771 (United States)

    2009-03-01

    Coherent systems offer significant advantages in simplicity, testability, control of systematics, and cost. Although quantum noise sets the fundamental limit to their performance at high frequencies, recent breakthroughs suggest that near-quantum-limited noise up to 150 or even 200 GHz could be realized within a few years. If the demands of component separation can be met with frequencies below 200 GHz, coherent systems will be strong competitors for a space CMB polarization mission. The rapid development of digital correlator capability now makes space interferometers with many hundreds of elements possible. Given the advantages of coherent interferometers in suppressing systematic effects, such systems deserve serious study.

  13. Effects of channel noise on firing coherence of small-world Hodgkin-Huxley neuronal networks

    Science.gov (United States)

    Sun, X. J.; Lei, J. Z.; Perc, M.; Lu, Q. S.; Lv, S. J.

    2011-01-01

    We investigate the effects of channel noise on firing coherence of Watts-Strogatz small-world networks consisting of biophysically realistic HH neurons having a fraction of blocked voltage-gated sodium and potassium ion channels embedded in their neuronal membranes. The intensity of channel noise is determined by the number of non-blocked ion channels, which depends on the fraction of working ion channels and the membrane patch size with the assumption of homogeneous ion channel density. We find that firing coherence of the neuronal network can be either enhanced or reduced depending on the source of channel noise. As shown in this paper, sodium channel noise reduces firing coherence of neuronal networks; in contrast, potassium channel noise enhances it. Furthermore, compared with potassium channel noise, sodium channel noise plays a dominant role in affecting firing coherence of the neuronal network. Moreover, we declare that the observed phenomena are independent of the rewiring probability.

  14. Computer simulation for the effect of coherent strain on the precipitation progress of binary alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the microscopic elasticity theory and microscopic diffusion equation, the precipitation progress of the binary alloys including coherent strain energy was studied. The results show that coherent strain has obvious effect on the coherent two-phase morphology and precipitation mechanism. With the increase of coherent strain energy, the particles shape changes from the randomly distributed equiaxed particels to elliptical precipitate shapes, their arrangement orientation increases; in the late stage of precipitation, the particle arrangement presents obvious directionality along the [10] and [01] directions, and the precipitation mechanism of alloy changes from typical spinodal decomposition mechanism to the mixture process which possesses the characteristics of both non-classical nucleation growth and spinodal decomposition mechanisms.

  15. Adaptive noise cancellation

    International Nuclear Information System (INIS)

    Akram, N.

    1999-01-01

    In this report we describe the concept of adaptive noise canceling, an alternative method of estimating signals corrupted by additive noise of interference. The method uses 'primary' input containing the corrupted signal and a 'reference' input containing noise correlated in some unknown way with the primary noise, the reference input is adaptively filtered and subtracted from the primary input to obtain the signal estimate. Adaptive filtering before subtraction allows the treatment of inputs that are deterministic or stochastic, stationary or time variable. When the reference input is free of signal and certain other conditions are met then noise in the primary input can be essentially eliminated without signal distortion. It is further shown that the adaptive filter also acts as notch filter. Simulated results illustrate the usefulness of the adaptive noise canceling technique. (author)

  16. Geneva University - Cancelled

    CERN Multimedia

    Université de Genève

    2010-01-01

    École de physique - Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 - Fax: (022) 379 69 92 Monday 19 April 2010 17h00 - Stückelberg Auditorium Into the darkness: Simulating the distribution of dark matter in our Universe Prof. Volker Springel - Heidelberg Institute for Theoretical Studies   THE COLLOQUIUM IS CANCELLED. Prof. Markus Büttiker

  17. Generating cancelable fingerprint templates.

    Science.gov (United States)

    Ratha, Nalini K; Chikkerur, Sharat; Connell, Jonathan H; Bolle, Ruud M

    2007-04-01

    Biometrics-based authentication systems offer obvious usability advantages over traditional password and token-based authentication schemes. However, biometrics raises several privacy concerns. A biometric is permanently associated with a user and cannot be changed. Hence, if a biometric identifier is compromised, it is lost forever and possibly for every application where the biometric is used. Moreover, if the same biometric is used in multiple applications, a user can potentially be tracked from one application to the next by cross-matching biometric databases. In this paper, we demonstrate several methods to generate multiple cancelable identifiers from fingerprint images to overcome these problems. In essence, a user can be given as many biometric identifiers as needed by issuing a new transformation "key." The identifiers can be cancelled and replaced when compromised. We empirically compare the performance of several algorithms such as Cartesian, polar, and surface folding transformations of the minutiae positions. It is demonstrated through multiple experiments that we can achieve revocability and prevent cross-matching of biometric databases. It is also shown that the transforms are noninvertible by demonstrating that it is computationally as hard to recover the original biometric identifier from a transformed version as by randomly guessing. Based on these empirical results and a theoretical analysis we conclude that feature-level cancelable biometric construction is practicable in large biometric deployments.

  18. Coherent synchrotron radiation experiments for the LCLS

    International Nuclear Information System (INIS)

    Carlsten, B.E.; Russell, S.J.

    1998-01-01

    The authors describe a coherent synchrotron radiation experiment planned at Los Alamos to support the design of the Linac Coherent Light Source (LCLS) x-ray FEL. Preliminary simulations of the LCLS compressors show that a clever tuning strategy can be used to minimize the electron's beam emittance growth due to noninertial space-charge forces by employing a delicate cancellation of these forces. The purpose of the Los Alamos experiment, using a sub-picosecond chicane compressor, is to benchmark these simulations tools. In this paper, the authors present detailed numerical simulations of the experiment, and point out unique signatures of this effect that are measurable. As predicted previously, the largest emittance growths and induced energy spreads result from the nonradiative components of this space-charge force

  19. The application of cost-effective lasers in coherent UDWDM-OFDM-PON aided by effective phase noise suppression methods.

    Science.gov (United States)

    Liu, Yue; Yang, Chuanchuan; Yang, Feng; Li, Hongbin

    2014-03-24

    Digital coherent passive optical network (PON), especially the coherent orthogonal frequency division multiplexing PON (OFDM-PON), is a strong candidate for the 2nd-stage-next-generation PON (NG-PON2). As is known, OFDM is very sensitive to the laser phase noise which severely limits the application of the cost-effective distributed feedback (DFB) lasers and more energy-efficient vertical cavity surface emitting lasers (VCSEL) in the coherent OFDM-PON. The current long-reach coherent OFDM-PON experiments always choose the expensive external cavity laser (ECL) as the optical source for its narrow linewidth (usuallyOFDM-PON and study the possibility of the application of the DFB lasers and VCSEL in coherent OFDM-PON. A typical long-reach coherent ultra dense wavelength division multiplexing (UDWDM) OFDM-PON has been set up. The numerical results prove that the OBE method can stand severe phase noise of the lasers in this architecture and the DFB lasers as well as VCSEL can be used in coherent OFDM-PON. In this paper, we have also analyzed the performance of the RF-pilot-aided (RFP) phase noise suppression method in coherent OFDM-PON.

  20. Effect of semantic coherence on episodic memory processes in schizophrenia.

    Science.gov (United States)

    Battal Merlet, Lâle; Morel, Shasha; Blanchet, Alain; Lockman, Hazlin; Kostova, Milena

    2014-12-30

    Schizophrenia is associated with severe episodic retrieval impairment. The aim of this study was to investigate the possibility that schizophrenia patients could improve their familiarity and/or recollection processes by manipulating the semantic coherence of to-be-learned stimuli and using deep encoding. Twelve schizophrenia patients and 12 healthy controls of comparable age, gender, and educational level undertook an associative recognition memory task. The stimuli consisted of pairs of words that were either related or unrelated to a given semantic category. The process dissociation procedure was used to calculate the estimates of familiarity and recollection processes. Both groups showed enhanced memory performances for semantically related words. However, in healthy controls, semantic relatedness led to enhanced recollection, while in schizophrenia patients, it induced enhanced familiarity. The familiarity estimates for related words were comparable in both groups, indicating that familiarity could be used as a compensatory mechanism in schizophrenia patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Measurement and analysis of coherent synchrotron radiation effects at FLASH

    International Nuclear Information System (INIS)

    Beutner, B.

    2007-12-01

    The vacuum-ultra-violet Free Electron Laser in Hamburg (FLASH) is a linac driven SASE-FEL. High peak currents are produced using magnetic bunch compression chicanes. In these magnetic chicanes, the energy distribution along an electron bunch is changed by eff ects of Coherent Synchrotron Radiation (CSR). Energy changes in dispersive bunch compressor chicanes lead to transverse displacements along the bunch. These CSR induced displacements are studied using a transverse deflecting RF-structure. Experiments and simulations concerning the charge dependence of such transverse displacements are presented and analysed. In these experiments an over-compression scheme is used which reduces the peak current downstream the bunch compressor chicanes. Therefore other self interactions like space charge forces which might complicate the measurements are suppressed. Numerical simulations are used to analyse the beam dynamics under the influence of CSR forces. The results of these numerical simulations are compared with the data obtained in the over-compression experiments at FLASH. (orig.)

  2. Measurement and analysis of coherent synchrotron radiation effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Beutner, B.

    2007-12-15

    The vacuum-ultra-violet Free Electron Laser in Hamburg (FLASH) is a linac driven SASE-FEL. High peak currents are produced using magnetic bunch compression chicanes. In these magnetic chicanes, the energy distribution along an electron bunch is changed by eff ects of Coherent Synchrotron Radiation (CSR). Energy changes in dispersive bunch compressor chicanes lead to transverse displacements along the bunch. These CSR induced displacements are studied using a transverse deflecting RF-structure. Experiments and simulations concerning the charge dependence of such transverse displacements are presented and analysed. In these experiments an over-compression scheme is used which reduces the peak current downstream the bunch compressor chicanes. Therefore other self interactions like space charge forces which might complicate the measurements are suppressed. Numerical simulations are used to analyse the beam dynamics under the influence of CSR forces. The results of these numerical simulations are compared with the data obtained in the over-compression experiments at FLASH. (orig.)

  3. Chromatic dispersion effects in ultra-low coherence interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Lychagov, V V; Ryabukho, V P [N.G.Chernyshevsky Saratov State University (Russian Federation)

    2015-06-30

    We consider the properties of an interference signal shift from zero-path-difference position in the presence of an uncompensated dispersive layer in one of the interferometer arms. It is experimentally shown that in using an ultra-low coherence light source, the formation of the interference signal is also determined by the group velocity dispersion, which results in a nonlinear dependence of the position of the interference signal on the geometrical thickness of the dispersive layer. The discrepancy in the dispersive layer and compensator refractive indices in the third decimal place is experimentally shown to lead to an interference signal shift that is an order of magnitude greater than the pulse width. (interferometry)

  4. Does anti-androgen, flutamide cancel out the in vivo effects of the androgen, dihydrotestosterone on sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis)?

    Science.gov (United States)

    Bhatia, Harpreet; Kumar, Anupama

    2016-01-01

    The aim of the present study was to investigate if the effects of the androgen, dihydrotestosterone (DHT) on the sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis) are canceled out by the anti-androgen, flutamide. Fish (60 days post hatch) were exposed to 250ng/L of DHT, 25μg/L of flutamide (Flu-low), 250μg/L of flutamide (Flu-high), DHT+Flu low and DHT+Flu high. After 35 days of exposure, lengths and weights of the fish were measured and the condition factor (CF) calculated; vitellogenin (VTG) concentrations were measured in tail tissue; sex steroid hormones (17β-estradiol [E2] and 11-keto testosterone [11-KT]) were measured in the head tissue and abdominal regions were used in histological investigation of the gonads. Treatment with DHT reduced the body-length of both male and female fish, an effect which was canceled out by low and high concentrations of flutamide. However, flutamide (low or high) could not nullify the DHT-induced reduction in the CF in either sex. The E2 levels were reduced only in female fish after exposure to DHT but returned to normal after treatment with Flu-high. DHT increased the levels of 11-KT and decreased the E2/11-KT ratio in both sexes. Flu-high, but not Flu-low, could nullify these effects. Both DHT and flutamide (low or high) induced VTG production and this effect persisted when both chemicals were co-administered. Treatment with DHT did not affect gonadal cell development in the testes. However, the female fish treated with DHT contained ovaries in early-vitellogenic stage in comparison to the pre-vitellogenic ovaries in control fish. Co-treatment with flutamide (low or high) resulted in oocyte atresia. The results from the present study suggest that treatment with Flu-high could cancel out DHT-induced effects only on the hormonal profile and body-length in both male and female fish. Juvenile fish co-treated with DHT and flutamide (low or high) had high VTG levels and low CF. In addition, the ovaries

  5. Interpixel crosstalk cancellation on holographic memory

    Science.gov (United States)

    Ishii, Toshiki; Fujimura, Ryushi

    2017-09-01

    In holographic memory systems, there have been no practical techniques to minimize interpixel crosstalk thus far. We developed an interpixel crosstalk cancellation technique using a checkerboard phase pattern with a phase difference of π/2, which can decrease the size of the spatial filter along the Fourier plane with the signal-to-noise ratio (SNR) kept high. This interpixel crosstalk cancellation technique is simple because it requires only one phase plate in the signal beam path. We verified the effect of such a cancellation technique by simulation. The improvement of SNR is maximized to 6.5 dB when the filter size specified in the Nyquist areal ratio is approximately 1.05 in ideal optical systems with no other fixed noise. The proposed technique can improve SNR by 0.85 in an assumed monocular architecture at an actual noise intensity. This improvement of SNR is very useful for realizing high-density recording or enhancing system robustness.

  6. Special relativity effects for space-based coherent lidar experiments

    Science.gov (United States)

    Raogudimetla, V. S.

    1994-01-01

    There is a great need to develop a system that can measure accurately atmospheric wind profiles because an accurate data of wind profiles in the atmosphere constitutes single most input for reliable simulations of global climate numerical methods. Also such data helps us understand atmospheric circulation and climate dynamics better. Because of this need for accurate wind measurements, a space-based Laser Atmospheric Winds Sounder (LAWS) is being designed at MSFC to measure wind profiles in the lower atmosphere of the earth with an accuracy of 1 m/s at lower altitudes to 5m/s at higher altitudes. This system uses an orbiting spacecraft with a pulsed laser source and measures the Doppler shift between the transmitted and received frequencies to estimate the atmospheric wind velocities. If a significant return from the ground (sea) is possible, the spacecraft speed and height are estimated from it and these results and the Doppler shift are then used to estimate the wind velocities in the atmosphere. It is expected that at the proposed wavelengths, there will be enough backscatter from the aerosols but there may no be significant return from the ground. So a coherent (heterodyne) detection system is being proposed for signal processing because it can provide high signal to noise ratio and sensitivity and thus make the best use of low ground return. However, for a heterodyne detection scheme to provide the best results, it is important that the receiving aperture be aligned properly for the proposed wind sounder, this amounts to only a few microradians tolerance in alignment. It is suspected that the satellite motion relative to the ground may introduce errors in the order of a few microradians because of special relativity. Hence, the problem of laser scattering off a moving fixed target when the source and receiver are moving, which was not treated in the past in the literature, was analyzed in the following, using relativistic electrodynamics and applied to the

  7. Energy loss and (de)coherence effects beyond eikonal approximation

    CERN Document Server

    Apolinário, Liliana; Milhano, Guilherme; Salgado, Carlos A.

    2014-01-01

    The parton branching process is known to be modified in the presence of a medium. Colour decoherence processes are known to determine the process of energy loss when the density of the medium is large enough to break the correlations between partons emitted from the same parent. In order to improve existing calculations that consider eikonal trajectories for both the emitter and the hardest emitted parton, we provide in this work, the calculation of all finite energy corrections for the gluon radiation off a quark in a QCD medium that exist in the small angle approximation and for static scattering centres. Using the path integral formalism, all particles are allowed to undergo Brownian motion in the transverse plane and the offspring allowed to carry an arbitrary fraction of the initial energy. The result is a general expression that contains both coherence and decoherence regimes that are controlled by the density of the medium and by the amount of broadening that each parton acquires independently.

  8. An Event Related Potentials Study of Semantic Coherence Effect during Episodic Encoding in Schizophrenia Patients

    Directory of Open Access Journals (Sweden)

    Lâle Battal Merlet

    2018-01-01

    Full Text Available The objective of this electrophysiological study was to investigate the processing of semantic coherence during encoding in relation to episodic memory processes promoted at test, in schizophrenia patients, by using the N400 paradigm. Eighteen schizophrenia patients and 15 healthy participants undertook a recognition memory task. The stimuli consisted of pairs of words either semantically related or unrelated to a given category name (context. During encoding, both groups exhibited an N400 external semantic coherence effect. Healthy controls also showed an N400 internal semantic coherence effect, but this effect was not present in patients. At test, related stimuli were accompanied by an FN400 old/new effect in both groups and by a parietal old/new effect in the control group alone. In the patient group, external semantic coherence effect was associated with FN400, while, in the control group, it was correlated to the parietal old/new effect. Our results indicate that schizophrenia patients can process the contextual information at encoding to enhance familiarity process for related stimuli at test. Therefore, cognitive rehabilitation therapies targeting the implementation of semantic encoding strategies can mobilize familiarity which in turn can overcome the recollection deficit, promoting successful episodic memory performance in schizophrenia patients.

  9. Coherent optical effect on time-resolved vibrational SFG spectrum of adsorbates

    Science.gov (United States)

    Ueba, H.; Sawabu, T.; Mii, T.

    2002-04-01

    We present a theory to study the influence of the coherent mixing between pump-infrared and probe-visible pulse on a time-resolved sum-frequency generation (TR-SFG) spectrum for vibrations at surfaces. The general formula of the time-dependent and its Fourier transform of the SFG polarization and its Fourier transform allows us to calculate the time-resolved vibrational SFG spectrum and the transient characteristics of the SFG intensity as a function of the delay time td between the pump-infrared and probe-visible pulse. It is found the coherent optical effect manifests itself in the broadening and narrowing of the SFG spectrum with the intrinsic width of T2 at negative and positive td, respectively, being in qualitative agreement with recent experimental results. The influence of the coherent mixing on the transient behavior of the SFG intensity is also discussed in conjunction to the T2 determination.

  10. 48 CFR 552.238-73 - Cancellation.

    Science.gov (United States)

    2010-10-01

    ... may cancel this contract in whole or in part by providing written notice. The cancellation will take... elects to cancel this contract, the Government will not reimburse the minimum guarantee. (End of clause) ...

  11. Coherence effects and average multiplicity in deep inelastic scattering at small χ

    International Nuclear Information System (INIS)

    Kisselev, A.V.; Petrov, V.A.

    1988-01-01

    The average hadron multiplicity in deep inelastic scattering at small χ is calculated in this paper. Its relationship with the average multiplicity in e + e - annihilation is established. As shown the results do not depend on a choice of the gauge vector. The important role of coherence effects in both space-like and time-like jet evolution is clarified. (orig.)

  12. Coherently enhanced radiation reaction effects in laser-vacuum acceleration of electron bunches

    NARCIS (Netherlands)

    Smorenburg, P.W.; Kamp, L.P.J.; Geloni, G.; Luiten, O.J.

    2010-01-01

    The effects of coherently enhanced radiation reaction on the motion of subwavelength electron bunches in interaction with intense laser pulses are analyzed. The radiation reaction force behaves as a radiation pressure in the laser beam direction, combined with a viscous force in the perpendicular

  13. Effect of ovariectomy on BMD, micro-architecture and biomechanics of cortical and cancellous bones in a sheep model.

    Science.gov (United States)

    Wu, Zi-xiang; Lei, Wei; Hu, Yun-yu; Wang, Hai-qiang; Wan, Shi-yong; Ma, Zhen-sheng; Sang, Hong-xun; Fu, Suo-chao; Han, Yi-sheng

    2008-11-01

    Osteoporotic/osteopenia fractures occur most frequently in trabeculae-rich skeletal sites. The purpose of this study was to use a high-resolution micro-computed tomography (micro-CT) and dual energy X-ray absorptionmeter (DEXA) to investigate the changes in micro-architecture and bone mineral density (BMD) in a sheep model resulted from ovariectomy (OVX). Biomechanical tests were performed to evaluate the strength of the trabecular bone. Twenty adult sheeps were randomly divided into three groups: sham group (n=8), group 1 (n=4) and group 2 (n=8). In groups 1 and 2, all sheep were ovariectomized (OVX); in the sham group, the ovaries were located and the oviducts were ligated. In all animals, BMD for lumbar spine was obtained during the surgical procedure. BMD at the spine, femoral neck and femoral condyle was determined 6 months (group 1) and 12 months (group 2) post-OVX. Lumbar spines and femora were obtained and underwent BMD scan, micro-CT analysis. Compressive mechanical properties were determined from biopsies of vertebral bodies and femoral condyles. BMD, micro-architectural parameters and mechanical properties of cancellous bone did not decrease significantly at 6 months post-OVX. Twelve months after OVX, BMD, micro-architectural parameters and mechanical properties decreased significantly. The results of linear regression analyses showed that trabecular thickness (Tb.Th) (r=0.945, R2=0.886) and bone volume fraction (BV/TV) (r=0.783, R2=0.586) had strong (R2>0.5) correlation to compression stress. In OVX sheep, changes in the structural parameters of trabecular bone are comparable to the human situation during osteoporosis was induced. The sheep model presented seems to meet the criteria for an osteopenia model for fracture treatment with respect to morphometric and mechanical properties. But the duration of OVX must be longer than 12 months to ensure the animal model can be established successfully.

  14. The effect of n- and p-type doping on coherent phonons in GaN.

    Science.gov (United States)

    Ishioka, Kunie; Kato, Keiko; Ohashi, Naoki; Haneda, Hajime; Kitajima, Masahiro; Petek, Hrvoje

    2013-05-22

    The effect of doping on the carrier-phonon interaction in wurtzite GaN is investigated by pump-probe reflectivity measurements using 3.1 eV light in near resonance with the fundamental band gap of 3.39 eV. Coherent modulations of the reflectivity due to the E2 and A1(LO) modes, as well as the 2A1(LO) overtone are observed. Doping of acceptor and donor atoms enhances the dephasing of the polar A1(LO) phonon via coupling with plasmons, with the effect of donors being stronger. Doping also enhances the relative amplitude of the coherent A1(LO) phonon with respect to that of the high-frequency E2 phonon, though it does not affect the relative intensity in Raman spectroscopic measurements. We attribute this enhanced coherent amplitude to the transient depletion field screening (TDFS) excitation mechanism, which, in addition to impulsive stimulated Raman scattering (ISRS), contributes to the generation of coherent polar phonons even for sub-band gap excitation. Because the TDFS mechanism requires photoexcitation of carriers, we argue that the interband transition is made possible at a surface with photon energies below the bulk band gap through the Franz-Keldysh effect.

  15. Coherent charge fluctuations in Josephson junctions and the oscillations of the effective capacitance

    International Nuclear Information System (INIS)

    Krive, I.V.; Rozhavsky, A.S.

    1990-07-01

    We predict novel voltage oscillations of the effective capacitance of small Josephson junctions. This macroscopic effect involves coherent charge fluctuations with charge 2e, leading to a period of oscillations, V c = 2e/C, where C is the junction capacitance. The amplitude of the effect decreases with temperature as exp(-π 2 T/ε c ), where ε c = (2e) 2 /C. (author). 6 refs

  16. Characterization of a clock based on coherent population trapping in a thermal cesium vapor. Main effects that may affect its mid- and long-term frequency stability

    International Nuclear Information System (INIS)

    Kozlova, Olga

    2013-01-01

    This thesis describes a Cs - buffer gas vapor cell atomic clock based on coherent population trapping (CPT), and the main frequency shifts affecting its mid- and long-term stability. The developed atomic clock based on CPT uses two original techniques: a so-called double-Λ scheme for the CPT-resonance excitation and a temporal Ramsey interrogation technique, which produce a high contrast and narrow resonances with reduced light shift dependence. Generally, the mid and long term stability of the vapor cell atomic clock is limited by the collisional shift induced by alkali-buffer gas collisions and the light shift (or the effects depending on the laser intensity). We report on the study of the collisional shift of Cs clock frequency in the presence of Ne, N 2 or Ar buffer gas, and its temperature dependence. The coefficient values of this dependence for these three buffer gases were revealed (some of them for the first time), allowing us to realise a cell with optimal combination of buffer gases to cancel the temperature dependence around the working temperature. Following the study of the signal amplitude and the coherence relaxation rate the optimal values for such parameters as interrogation cycle, magnetic field, cell temperature, pressure of the buffer gas mixture, etc. were found for the chosen cell. The investigation on the light shift and the effects depending on the laser intensity allowed us to determine the most sensitive parameters (laser intensity ratio, temperature) and to implement the required stabilizations in order to better control them. Finally, the mid- and long-term clock frequency stability was improved by a factor 40, reaching 2.5 10 -14 at 1 hour. (author)

  17. Effective Linewidth of Semiconductor Lasers for Coherent Optical Data Links

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Pang, Xiaodan; Schatz, Richard

    2016-01-01

    name “Effective Linewidth”. We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28 Gbaud DP-16QAM over an optical link. Our investigations cover the use of semiconductor lasers both in the transmitter side...... and as a local oscillator at the receiver. The obtained results show that our proposed “effective linewidth” is easy to measure and accounts for frequency noise more accurately, and hence the penalties associated to phase noise in the received signal....

  18. Color coherent effects in (e,e{prime}N) and (e,e{prime}N,N(h)) processes at CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Frankfurt, L.L.; Sargsyan, M.M. [Tel Aviv Univ. (Israel); Strikman, M.I. [Pennsylvania State Univ., University Park, PA (United States)]|[St. Petersburg Nuclear Physics Inst. (Russian Federation)

    1994-04-01

    The options for investigating color coherent effects and competing nuclear effects of nucleon-nucleon correlations in nuclei, nuclear shell effects in (e, e{prime}N) and (e, e{prime}NN(h)) reactions are considered. They argue that extension of CEBAF energies to reach Q{sup 2} = 10 GeV{sup 2} will allow systematical investigations of color coherent effects in nonperturbative regime of QCD and their interplay with nuclear effects.

  19. Color coherent effects in (e,e'N) and (e,e'N,N(h)) processes at CEBAF

    International Nuclear Information System (INIS)

    Frankfurt, L.L.; Sargsyan, M.M.; Strikman, M.I.

    1994-01-01

    The options for investigating color coherent effects and competing nuclear effects of nucleon-nucleon correlations in nuclei, nuclear shell effects in (e, e'N) and (e, e'NN(h)) reactions are considered. They argue that extension of CEBAF energies to reach Q 2 = 10 GeV 2 will allow systematical investigations of color coherent effects in nonperturbative regime of QCD and their interplay with nuclear effects

  20. Finite life time effects in the coherent exciton transfer

    International Nuclear Information System (INIS)

    Barvik, I.; Herman, P.

    1992-04-01

    The paper addresses a specific problem in the exciton transfer in molecular aggregates, namely the influence of the finite life time effects, on the memory functions entering the Generalized Master Equation (GME) which connect different sites of the system. 7 refs, 2 figs

  1. Defocusing effects of lensless ghost imaging and ghost diffraction with partially coherent sources

    Science.gov (United States)

    Zhou, Shuang-Xi; Sheng, Wei; Bi, Yu-Bo; Luo, Chun-Ling

    2018-04-01

    The defocusing effect is inevitable and degrades the image quality in the conventional optical imaging process significantly due to the close confinement of the imaging lens. Based on classical optical coherent theory and linear algebra, we develop a unified formula to describe the defocusing effects of both lensless ghost imaging (LGI) and lensless ghost diffraction (LGD) systems with a partially coherent source. Numerical examples are given to illustrate the influence of defocusing length on the quality of LGI and LGD. We find that the defocusing effects of the test and reference paths in the LGI or LGD systems are entirely different, while the LGD system is more robust against defocusing than the LGI system. Specifically, we find that the imaging process for LGD systems can be viewed as pinhole imaging, which may find applications in ultra-short-wave band imaging without imaging lenses, e.g. x-ray diffraction and γ-ray imaging.

  2. Non-linear signal response functions and their effects on the statistical and noise cancellation properties of isotope ratio measurements by multi-collector plasma mass spectrometry

    International Nuclear Information System (INIS)

    Doherty, W.

    2013-01-01

    A nebulizer-centric response function model of the analytical inductively coupled argon plasma ion source was used to investigate the statistical frequency distributions and noise reduction factors of simultaneously measured flicker noise limited isotope ion signals and their ratios. The response function model was extended by assuming i) a single gaussian distributed random noise source (nebulizer gas pressure fluctuations) and ii) the isotope ion signal response is a parabolic function of the nebulizer gas pressure. Model calculations of ion signal and signal ratio histograms were obtained by applying the statistical method of translation to the non-linear response function model of the plasma. Histograms of Ni, Cu, Pr, Tl and Pb isotope ion signals measured using a multi-collector plasma mass spectrometer were, without exception, negative skew. Histograms of the corresponding isotope ratios of Ni, Cu, Tl and Pb were either positive or negative skew. There was a complete agreement between the measured and model calculated histogram skew properties. The nebulizer-centric response function model was also used to investigate the effect of non-linear response functions on the effectiveness of noise cancellation by signal division. An alternative noise correction procedure suitable for parabolic signal response functions was derived and applied to measurements of isotope ratios of Cu, Ni, Pb and Tl. The largest noise reduction factors were always obtained when the non-linearity of the response functions was taken into account by the isotope ratio calculation. Possible applications of the nebulizer-centric response function model to other types of analytical instrumentation, large amplitude signal noise sources (e.g., lasers, pumped nebulizers) and analytical error in isotope ratio measurements by multi-collector plasma mass spectrometry are discussed. - Highlights: ► Isotope ion signal noise is modelled as a parabolic transform of a gaussian variable. ► Flicker

  3. Coherent interference effects and squeezed light generation in optomechanical systems

    Science.gov (United States)

    Qu, Kenan

    My Ph.D. dissertation is on the fundamental effects in optomechanical systems (OMS) and their important applications. The OMS are based on the possibility of the mechanical motion produced by few photons incident on the mechanical device. This dissertation presents several applications of the OMS in the area of storage of light in long-lived phonons, single mode optomechanical Ramsey interferometry, and generation of large amount of squeezing in the output radiation. The long-lived phonons can be monitored and controlled via optical means as was experimentally demonstrated. To show this, I develop the theory of transient electromagnetically induced transparency (EIT). For further applications like state transfer, especially over very different frequency regimes, I consider double-cavity OMS, where the two cavities can correspond to different spectral domains, yet the state transfer is possible via phonons. The state transfer is based on a new effect, electromagnetically induced absorption (EIA), where one uses a second control field from the other cavity to produce an absorption peak inside the EIT window. All these involve the interference of various path ways via which a final state is reached. The following chapter shows how Fano-like interference can arise in OMS. A Fano asymmetry parameter for OMS was defined. The last two chapters deal with the question if OMS can be efficient generators of squeezed light. I show by blue and red tuning the two cavities in a double-cavity OMS, one can generate effectively a two-mode parametric interaction which yields two-mode squeezed output with the squeezing magnitude of the order of 10dB. This requires a bath temperature of 10mK. Such temperatures obtained by using Helium dilution refrigerator are routinely used with superconducting OMS. The major part of this dissertation is devoted to the dispersive optomechanical interaction. However, the interaction can also be dissipative, where the mechanical displacement modulates

  4. An interface energy density-based theory considering the coherent interface effect in nanomaterials

    Science.gov (United States)

    Yao, Yin; Chen, Shaohua; Fang, Daining

    2017-02-01

    To characterize the coherent interface effect conveniently and feasibly in nanomaterials, a continuum theory is proposed that is based on the concept of the interface free energy density, which is a dominant factor affecting the mechanical properties of the coherent interface in materials of all scales. The effect of the residual strain caused by self-relaxation and the lattice misfit of nanomaterials, as well as that due to the interface deformation induced by an external load on the interface free energy density is considered. In contrast to the existing theories, the stress discontinuity at the interface is characterized by the interface free energy density through an interface-induced traction. As a result, the interface elastic constant introduced in previous theories, which is not easy to determine precisely, is avoided in the present theory. Only the surface energy density of the bulk materials forming the interface, the relaxation parameter induced by surface relaxation, and the mismatch parameter for forming a coherent interface between the two surfaces are involved. All the related parameters are far easier to determine than the interface elastic constants. The effective bulk and shear moduli of a nanoparticle-reinforced nanocomposite are predicted using the proposed theory. Closed-form solutions are achieved, demonstrating the feasibility and convenience of the proposed model for predicting the interface effect in nanomaterials.

  5. Effect of pressure fluctuations on Richtmyer-Meshkov coherent structures

    Science.gov (United States)

    Bhowmick, Aklant K.; Abarzhi, Snezhana

    2016-11-01

    We investigate the formation and evolution of Richtmyer Meshkov bubbles after the passage of a shock wave across a two fluid interface in the presence of pressure fluctuations. The fluids are ideal and incompressible and the pressure fluctuations are scale invariant in space and time, and are modeled by a power law time dependent acceleration field with exponent -2. Solutions indicate sensitivity to pressure fluctuations. In the linear regime, the growth of curvature and bubble velocity is linear. The growth rate is dominated by the initial velocity for weak pressure fluctuations, and by the acceleration term for strong pressure fluctuations. In the non-linear regime, the bubble curvature is constant and the solutions form a one parameter family (parametrized by the bubble curvature). The solutions are shown to be convergent and asymptotically stable. The physical solution (stable fastest growing) is a flat bubble for small pressure fluctuations and a curved bubble for large pressure fluctuations. The velocity field (in the frame of references accounting for the background motion) involves intense motion of the fluids in a vicinity of the interface, effectively no motion of the fluids away from the interfaces, and formation of vortical structures at the interface. The work is supported by the US National Science Foundation.

  6. Addition of a Nitric Oxide Donor to an Angiotensin II Type 1 Receptor Blocker May Cancel Its Blood Pressure-Lowering Effects.

    Science.gov (United States)

    Yahiro, Eiji; Miura, Shin-Ichiro; Suematsu, Yasunori; Matsuo, Yoshino; Arimura, Tadaaki; Kuwano, Takashi; Imaizumi, Satoshi; Iwata, Atsushi; Uehara, Yoshinari; Saku, Keijiro

    2015-01-01

    While physiological levels of nitric oxide (NO) protect the endothelium and have vasodilatory effects, excessive NO has adverse effects on the cardiovascular system. Recently, new NO-releasing pharmacodynamic hybrids of angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) have been developed.We analyzed whether olmesartan with NO-donor side chains (Olm-NO) was superior to olmesartan (Olm) for the control of blood pressure (BP). Although there was no significant difference in binding affinity to AT1 wild-type (WT) receptor between Olm and Olm-NO in a cell-based binding assay, the suppressive effect of Olm-NO on Ang II-induced inositol phosphate (IP) production was significantly weaker than that of Olm in AT1 WT receptor-expressing cells. While Olm had a strong inverse agonistic effect on IP production, Olm-NO did not. Next, we divided 18 C57BL mice into 3 groups: Ang II (infusion using an osmotic mini-pump) as a control group, Ang II (n = 6) + Olm, and Ang II (n = 6) + Olm-NO groups (n = 6). Olm-NO did not block Ang II-induced high BP after 10 days, whereas Olm significantly decreased BP. In addition, Olm, but not Olm-NO, significantly reduced the ratio of heart weight to body weight (HW/BW) with downregulation of the mRNA levels of atrial natriuretic peptide.An ARB with a NO-donor may cancel BP-lowering effects probably due to excessive NO and a weak blocking effect by Olm-NO toward AT1 receptor activation.

  7. An improved probe noise approach for acoustic feedback cancellation

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    The perhaps most challenging problem in acoustic feedback cancellation using adaptive filters is the bias problem. It is well-known that a probe noise approach can effectively prevent this problem. However, when the probe noise must be inaudible and the steady-state error of the adaptive filter...... expressions for its system behavior, and through a simulation experiment in an acoustic feedback cancellation system....

  8. Coherence Effects in L-Band Active and Passive Remote Sensing of Quasi-Periodic Corn Canopies

    Science.gov (United States)

    Utku, Cuneyt; Lang, Roger H.

    2011-01-01

    Due to their highly random nature, vegetation canopies can be modeled using the incoherent transport theory for active and passive remote sensing applications. Agricultural vegetation canopies however are generally more structured than natural vegetation. The inherent row structure in agricultural canopies induces coherence effects disregarded by the transport theory. The objective of this study is to demonstrate, via Monte-Carlo simulations, these coherence effects on L-band scattering and thermal emission from corn canopies consisting of only stalks.

  9. The effects of Tai Chi practice on intermuscular beta coherence and the rubber hand illusion

    Directory of Open Access Journals (Sweden)

    Catherine eKerr

    2016-02-01

    Full Text Available Tai Chi (TC is a slow-motion contemplative exercise that is associated with improvements in sensorimotor measures, including decreased force variability, enhanced tactile acuity, and improved proprioception, especially in elderly populations. Here, we carried out two studies evaluating the effect of TC practice on measures associated with sensorimotor processing. In study 1, we evaluated TC’s effects on an oscillatory parameter associated with motor function, beta rhythm (15-30 Hz coherence, focusing specifically on beta rhythm intermuscular coherence (IMC, which is tightly coupled to beta corticomuscular coherence (CMC. We utilized electromyography (EMG to compare beta IMC in older TC practitioners with age-matched controls, as well as novices with advanced TC practitioners. Given previous findings of elevated, maladaptive beta coherence in older subjects, we hypothesized that increased TC practice would be associated with a monotonic decrease in beta IMC, but rather discovered that novice practitioners manifested higher beta IMC than both controls and advanced practitioners, forming an inverted U-shaped practice curve. This finding suggests that TC practice elicits complex changes in sensory and motor processes over the developmental lifespan of TC training. In study 2, we focused on somatosensory (e.g., tactile and proprioceptive responses to the Rubber Hand Illusion (RHI in a middle-aged TC group, assessing whether responses to the illusion became dampened with greater cumulative practice. As hypothesized, TC practice was associated with decreased likelihood to misattribute tactile stimulation during the RHI to the rubber hand, although there was no effect of TC practice on measures of proprioception or on subjective reports of ownership. These studies provide preliminary evidence that TC practice modulates beta network coherence in a non-linear fashion, perhaps as a result of the focus on not only efferent motor but also afferent sensory

  10. The effect of the precipitation of coherent and incoherent precipitates on the ductility and toughness of high-strength steel

    International Nuclear Information System (INIS)

    Hamano, R.

    1993-01-01

    The effect of the coexistence of coherent and incoherent precipitates, such as M 2 C and NiAl, on the ductility and plane strain fracture toughness of 5 wt pct Ni-2 wt pct Al-based high-strength steels was studied. In order to disperse coherent and incoherent precipitates, the heat treatments were carried out as follows: (a) austenitizing at 1373 K, (b) tempering at 1023 or 923 K for dispersing the incoherent precipitates of M 2 C and NiAl, and then (c) aging at 843 K for 2.4 ks to disperse the coherent precipitate of NiAl into the matrix, which contains incoherent precipitates, such as M 2 C and NiAl. The results were obtained as follows: (a) when the strengthening precipitates consist of coherent ones, such as M 2 C and/or NiAl, the ductility and toughness are extremely low, and (b) when the strengthening precipitates consist of coherent and incoherent precipitates, such as M 2 C and NiAl, the ductility and fracture toughness significantly increase with no loss in strength. It is shown that the coexistence of coherent and incoherent precipitates increases homogeneous deformation, thus preventing local strain concentration and early cleavage cracking. Accordingly, the actions of coherent precipitates in strengthening the matrix and of incoherent precipitates in promoting, homogeneous deformation can be expected to increase both the strength and toughness of the material

  11. Reducing the Effects of Background Noise during Auditory Functional Magnetic Resonance Imaging of Speech Processing: Qualitative and Quantitative Comparisons between Two Image Acquisition Schemes and Noise Cancellation

    Science.gov (United States)

    Blackman, Graham A.; Hall, Deborah A.

    2011-01-01

    Purpose: The intense sound generated during functional magnetic resonance imaging (fMRI) complicates studies of speech and hearing. This experiment evaluated the benefits of using active noise cancellation (ANC), which attenuates the level of the scanner sound at the participant's ear by up to 35 dB around the peak at 600 Hz. Method: Speech and…

  12. Effect of magnet sorting using a simple resonance cancellation method on the RMS orbit distortion at the APS injector synchrotron

    International Nuclear Information System (INIS)

    Lopez, F.; Koul, R.; Mills, F.E.

    1993-01-01

    The Advanced Photon Source injector synchrotron is a 7-GeV positron machine with a standard alternating gradient lattice. The calculated effect of dipole magnet strength errors on the orbit distortion, simulated by Monte Carlo, was reduced by sorting pairs of magnets having the closest simulated measured strengths to reduce the driving the term of the integer resonance nearest the operating point. This method resulted in a factor of four average reduction in the rms orbit distortion when all 68 magnets were sorted at once. The simulated effect of magnet measurement experimental resolution was found to limit the actual improvement. The Β-beat factors were similarly reduced by sorting the quadrupole magnets according to their gradients

  13. Effects of young-coconut juice on increasing mandibular cancellous bone in orchidectomized rats: Preliminary novel findings

    Directory of Open Access Journals (Sweden)

    Pranee Suwanpal

    2011-12-01

    Full Text Available Androgens play a very important role in building the skeleton in young adults and help to prevent bone loss andosteoporosis in aging men. In addition, in hypogonadism or elderly men, bone mass has been related to estrogen levels ratherthan to testosterone. Estrogen replacement therapy has therefore been proposed to prevent bone loss in males as well as infemales. Estrogen, however, has been considered to be one of the hormonal risk factors for benign prostatic hyperplasia andprostate cancer and also has other side effects. Young coconut juice (YCJ presumably containing phytoestrogen was investigatedin the present study for its possible beneficial effects on delaying osteoporosis using a male rat model, and by this totest the possibility that it might be able to replace estrogen replacement therapy without side effects. In this study, mandibularcancellous bone was used as the osteoporotic model. Using the same model, we have previously found that total cartilagethickness particularly the hypertrophic zone of mandibular condylar cartilage was thicker in the sham-operated rats receivingYCJ orally fed for a 14 day period, compared with sham, orchidectomized animal, orchidectomized rats receiving estradiolbenzoate, and orchidectomized rats receiving YCJ. The present study confirmed our former study that mandibular cancellousbone in the sham-operated rats and in the orchidectomized rats receiving YCJ orally fed for a 14–day period were thicker thanthose of the sham and orchidectomized rat groups. This study results are novel and they indicate that YCJ may have beneficialeffects in the treatment of osteoporosis in andropause men.

  14. Coherence effects in three- and four-level laser-cooled rubidium systems

    International Nuclear Information System (INIS)

    De Echaniz, Sebastian R.

    2002-01-01

    This thesis presents developmental work on the existing magneto-optical trap (MOT) system and novel studies of coherence effects. The developmental work was carried out on the experimental apparatus used previously in this laboratory in order to perform experiments to study coherence effects in three- and four-level rubidium systems in the MOT. This developmental work includes the upgrading and installation of new laser systems, the improvement of the MOT, the installation of data acquisition hardware and software, and the commissioning of a new 'second generation' MOT. As part of our studies of coherence effects, we present a wide-ranging theoretical and experimental study of non-adiabatic transient phenomena in a Λ system which exhibits electromagnetically induced transparency when a strong coupling field is rapidly switched on or off using a Pockels cell. The theoretical treatment uses a Laplace transform approach as well as standard numerical methods to solve the time-dependent density matrix equation. The results show clear Rabi oscillations and transient gain without population inversion of a weak probe in parameter regions not previously studied, and provide insight into the transition dynamics between bare a dressed states. Experimental studies of a doubly driven V system are also reported, together with a theoretical dressed-state analysis of such systems. The expected three-peak spectrum is explored for various coupling field strengths and detunings. In all this work we have found good agreement between the theory and the experimental spectra once light shifts and uncoupled absorption in the rubidium system are taken into account. (author)

  15. Effect of spatially correlated noise on coherence resonance in a network of excitable cells

    International Nuclear Information System (INIS)

    Kwon, Okyu; Jo, Hang-Hyun; Moon, Hie-Tae

    2005-01-01

    We study the effect of spatially correlated noise on coherence resonance (CR) in a Watts-Strogatz small-world network of Fitz Hugh-Nagumo neurons, where the noise correlation decays exponentially with distance between neurons. It is found that CR is considerably improved just by a small fraction of long-range connections for an intermediate coupling strength. For other coupling strengths, an abrupt change in CR occurs following the drastic fracture of the clustered structures in the network. Our study shows that spatially correlated noise plays a significant role in the phenomenon of CR reinforcing the role of the clustered structure of the system

  16. Effects of spontaneously generated coherence on the group velocity in a V system

    International Nuclear Information System (INIS)

    Bai Yanfeng; Guo Hong; Han, Dingan; Sun Hui

    2005-01-01

    We show how the application of an incoherent pumping can produce a variety of effects on the propagation of a weak electromagnetic pulse in a V system with spontaneously generated coherence (SGC). There exists an incoherent pumping rate which makes the group velocity reach the extremum near the region of two-photon resonant excitation. The existence of SGC is just the cause for the occurrence of the extremum, and it may also be regarded as a knob which can be used to manipulate light propagation from subluminal to superluminal

  17. Off-shell effects in the coherent π0 photoproduction off nuclei

    International Nuclear Information System (INIS)

    Chumbalov, A.A.; Kamalov, S.S.

    1987-01-01

    A strong sensitivity of coherent π 0 -meson photoproduction on nuclei to different ω reaction energy change in elementary amplitude t πγ (ω) is demonstrated. Various assumptions concerning ω behaviour in the extraenergy area can change differential cross sections 1.5-2 times. The best agreement of the DWIA-results with experimental data is obtained at ω being equal to its own value of pion-nucleon system free relativistic Hamiltonian. Such a result agrees with relativistic potential theory effects

  18. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    Science.gov (United States)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  19. A Polarimetric First-Order Model of Soil Moisture Effects on the DInSAR Coherence

    Directory of Open Access Journals (Sweden)

    Simon Zwieback

    2015-06-01

    Full Text Available Changes in soil moisture between two radar acquisitions can impact the observed coherence in differential interferometry: both coherence magnitude |Υ| and phase Φ are affected. The influence on the latter potentially biases the estimation of deformations. These effects have been found to be variable in magnitude and sign, as well as dependent on polarization, as opposed to predictions by existing models. Such diversity can be explained when the soil is modelled as a half-space with spatially varying dielectric properties and a rough interface. The first-order perturbative solution achieves–upon calibration with airborne L band data–median correlations ρ at HH polarization of 0.77 for the phase Φ, of 0.50 for |Υ|, and for the phase triplets ≡ of 0.56. The predictions are sensitive to the choice of dielectric mixing model, in particular the absorptive properties; the differences between the mixing models are found to be partially compensatable by varying the relative importance of surface and volume scattering. However, for half of the agricultural fields the Hallikainen mixing model cannot reproduce the observed sensitivities of the phase to soil moisture. In addition, the first-order expansion does not predict any impact on the HV coherence, which is however empirically found to display similar sensitivities to soil moisture as the co-pol channels HH and VV. These results indicate that the first-order solution, while not able to reproduce all observed phenomena, can capture some of the more salient patterns of the effect of soil moisture changes on the HH and VV DInSAR signals. Hence it may prove useful in separating the deformations from the moisture signals, thus yielding improved displacement estimates or new ways for inferring soil moisture.

  20. The effect of jitter on the performance of space coherent optical communication system with Costas loop

    Science.gov (United States)

    Li, Xin; Hong, Yifeng; Wang, Jinfang; Liu, Yang; Sun, Xun; Li, Mi

    2018-01-01

    Numerous communication techniques and optical devices successfully applied in space optical communication system indicates a good portability of it. With this good portability, typical coherent demodulation technique of Costas loop can be easily adopted in space optical communication system. As one of the components of pointing error, the effect of jitter plays an important role in the communication quality of such system. Here, we obtain the probability density functions (PDF) of different jitter degrees and explain their essential effect on the bit error rate (BER) space optical communication system. Also, under the effect of jitter, we research the bit error rate of space coherent optical communication system using Costas loop with different system parameters of transmission power, divergence angle, receiving diameter, avalanche photodiode (APD) gain, and phase deviation caused by Costas loop. Through a numerical simulation of this kind of communication system, we demonstrate the relationship between the BER and these system parameters, and some corresponding methods of system optimization are presented to enhance the communication quality.

  1. Coherent synchrotron radiation transient effects in the energy-dependent region

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Botman, Jan; Goloviznin, Vladimir; Wiel, Marnix van der

    2002-01-01

    Coherent synchrotron radiation (CSR) is a well known phenomenon that originates from coherent superposition of electromagnetic waves by ultrarelativistic electrons. CSR longitudinal effects during the passage of a Gaussian beam from a straight to a circular path have often been studied in a regime in which they are energy independent. Nevertheless, the approximations used in such a regime may fail in several practical situations, as in the case of low-energy injectors or for small-wavelength structures within the bunch distribution in CSR-related instability problems. These situations demand a deeper investigation of longitudinal transient effects in the region where the approximations above are no longer valid: a strong γ dependence is found, and described in this paper, in the rate of energy change induced by CSR during the transient of a Gaussian bunch between a straight and a circular path, which was studied with the help of the authors' previous work. Results show that the overall CSR longitudinal effects, in this case, are reduced. One of the outcomes of previous work by Saldin et al. was extended to this situation and very good agreement between the two studies was found

  2. 77 FR 19747 - Proposed Cancelation

    Science.gov (United States)

    2012-04-02

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Order 2012-3-7; Docket DOT-OST-2012-0022] Proposed Cancelation of the Air Taxi Authority Of VIH Cougar Helicopters, Inc. AGENCY: Department of... order finding that VIH Cougar Helicopters, Inc. is not a U.S. citizen as defined in 49 U.S.C. 40102(a...

  3. Effects of energetic coherent motions on the power and wake of an axial-flow turbine

    Science.gov (United States)

    Chamorro, L. P.; Hill, C.; Neary, V. S.; Gunawan, B.; Arndt, R. E. A.; Sotiropoulos, F.

    2015-05-01

    A laboratory experiment examined the effects of energetic coherent motions on the structure of the wake and power fluctuations generated by a model axial-flow hydrokinetic turbine. The model turbine was placed in an open-channel flow and operated under subcritical conditions. The incoming flow was locally perturbed with vertically oriented cylinders of various diameters. An array of three acoustic Doppler velocimeters aligned in the cross-stream direction and a torque transducer were used to collect high-resolution and synchronous measurements of the three-velocity components of the incoming and wake flow as well as the turbine power. A strong scale-to-scale interaction between the large-scale and broadband turbulence shed by the cylinders and the turbine power revealed how the turbulence structure modulates the turbine behavior. In particular, the response of the turbine to the distinctive von Kármán-type vortices shed from the cylinders highlighted this phenomenon. The mean and fluctuating characteristics of the turbine wake are shown to be very sensitive to the energetic motions present in the flow. Tip vortices were substantially dampened and the near-field mean wake recovery accelerated in the presence of energetic motions in the flow. Strong coherent motions are shown to be more effective than turbulence levels for triggering the break-up of the spiral structure of the tip-vortices.

  4. Emotion Regulation and Emotion Coherence: Evidence for Strategy-Specific Effects

    Science.gov (United States)

    Dan-Glauser, Elise S.; Gross, James J.

    2014-01-01

    One of the central tenets of emotion theory is that emotions involve coordinated changes across experiential, behavioral, and physiological response domains. Surprisingly little is known, however, on how the strength of this emotion coherence is altered when people try to regulate their emotions. To address this issue, we recorded experiential, behavioral, and physiological responses while participants watched negative and positive pictures. Cross-correlations were used to quantify emotion coherence. Study 1 tested how two types of suppression (expressive and physiological) influence coherence. Results showed that both strategies decreased the response coherence measured in negative and positive contexts. Study 2 tested how multi-channel suppression (simultaneously targeting expressive and physiological responses) and acceptance influence emotion coherence. Results again showed that suppression decreased coherence. By contrast, acceptance was not significantly different from the unregulated condition. These findings help to clarify the nature of emotion response coherence by showing how different forms of emotion regulation may differentially affect it. PMID:23731438

  5. Emotion regulation and emotion coherence: evidence for strategy-specific effects.

    Science.gov (United States)

    Dan-Glauser, Elise S; Gross, James J

    2013-10-01

    One of the central tenets of emotion theory is that emotions involve coordinated changes across experiential, behavioral, and physiological response domains. Surprisingly little is known, however, about how the strength of this emotion coherence is altered when people try to regulate their emotions. To address this issue, we recorded experiential, behavioral, and physiological responses while participants watched negative and positive pictures. Cross-correlations were used to quantify emotion coherence. Study 1 tested how two types of suppression (expressive and physiological) influence coherence. Results showed that both strategies decreased the response coherence measured in negative and positive contexts. Study 2 tested how multichannel suppression (simultaneously targeting expressive and physiological responses) and acceptance influence emotion coherence. Results again showed that suppression decreased coherence. By contrast, acceptance was not significantly different from the unregulated condition. These findings help to clarify the nature of emotion response coherence by showing how different forms of emotion regulation may differentially affect it.

  6. Effect of decoherence on fidelity in teleportation using entangled coherent states

    International Nuclear Information System (INIS)

    Prakash, H; Chandra, N; Prakash, R; Shivani

    2007-01-01

    A scheme of teleporting a superposition of coherent states (α) and ( - α) using a beam splitter and two phase shifters was proposed by van Enk and Hirota (2001 Phys. Rev. A 64 022313). The authors concluded that the probability for successful teleportation is 1/2. In this paper, it is shown that the authors' scheme can be altered slightly so as to obtain an almost perfect teleportation for an appreciable value of (α) 2 . For (α) 2 = 5, the minimum of average fidelity, which is the minimum of the sum of the product of probability of occurrence of any case, and the corresponding fidelity is less than 1 by a quantity ∼10 -4 . We also discuss the effect of decoherence on teleportation fidelity. We find that if no photons are counted in both final outputs, the minimum assured fidelity is still non-zero except when there is no decoherence and the information is an even coherent state. For non-zero photon counts, minimum assured fidelity decreases with an increase in (α) 2 for low noise. For high noise, however, it increases, attains a maximum value and then decreases with (α) 2 . The average fidelity depends appreciably on the information for low values of (α) 2 only

  7. Sense of coherence moderates late effects of early childhood Holocaust exposure.

    Science.gov (United States)

    van der Hal-van Raalte, Elisheva A M; van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J

    2008-12-01

    This study evaluated child Holocaust survivors with an emphasis on potential protective factors facilitating participants' adaptation to post-Holocaust life. We examined Antonovsky's (1979, 1987) salutogenic paradigm, testing the mediating and moderating effect of participants' sense of coherence (SOC) on the association between early childhood deprivation due to Holocaust persecution and posttraumatic stress later in life. The nonclinical sample, composed of 203 child Holocaust survivors born between 1935 and 1944 completed questionnaires on Holocaust survival exposure, inventories on current health, posttraumatic stress, and SOC. The results indicated that SOC moderates the association between traumatic experiences during the war and posttraumatic stress, and SOC acts as a protective factor, buffering the impact of traumatic Holocaust experiences on child survivors in old age. Survivors with a less coherent perspective on the meaning of their life showed greater vulnerability for posttraumatic complaints. The moderating role of the SOC may suggest promising avenues of therapeutic interventions for child Holocaust survivors and other adults with early childhood trauma. (c) 2008 Wiley Periodicals, Inc.

  8. Interband coherence response to electric fields in crystals: Berry-phase contributions and disorder effects

    Science.gov (United States)

    Culcer, Dimitrie; Sekine, Akihiko; MacDonald, Allan H.

    2017-07-01

    In solid state conductors, linear response to a steady electric field is normally dominated by Bloch state occupation number changes that are correlated with group velocity and lead to a steady state current. Recently it has been realized that, for a number of important physical observables, the most important response even in conductors can be electric-field induced coherence between Bloch states in different bands, such as that responsible for screening in dielectrics. Examples include the anomalous and spin-Hall effects, spin torques in magnetic conductors, and the minimum conductivity and chiral anomaly in Weyl and Dirac semimetals. In this paper we present a general quantum kinetic theory of linear response to an electric field which can be applied to solids with arbitrarily complicated band structures and includes the interband coherence response and the Bloch-state repopulation responses on an equal footing. One of the principal aims of our work is to enable extensive transport theory applications using computational packages constructed in terms of maximally localized Wannier functions. To this end we provide a complete correspondence between the Bloch and Wannier formulations of our theory. The formalism is based on density-matrix equations of motion, on a Born approximation treatment of disorder, and on an expansion in scattering rate to leading nontrivial order. Our use of a Born approximation omits some physical effects and represents a compromise between comprehensiveness and practicality. The quasiparticle bands are treated in a completely general manner that allows for arbitrary forms of the spin-orbit interaction and for the broken time reversal symmetry of magnetic conductors. We demonstrate that the interband response in conductors consists primarily of two terms: an intrinsic contribution due to the entire Fermi sea that captures, among other effects, the Berry curvature contribution to wave-packet dynamics, and an anomalous contribution caused

  9. CERN Library - Scientific journal cancellations

    CERN Multimedia

    2004-01-01

    Due to the constant increase of the subscription costs of scientific journals and the current budget restrictions, the Scientific Information Policy Board has mandated the Working Group for Acquisitions (WGA) together with the Library to propose a list of titles to be cancelled at the end of 2004. As a first step, the WGA has identified the scientific journals listed at the web site below as candidates for cancellation. The choice has been guided by the personal experience of the WGA members, consultation of other expert CERN staff for highly specialized titles, and by criteria such as subscription price, impact factor, and - where available - access statistics for electronic journals. The list also accounts for the fact that many titles are subscribed to in 'packages' such that a cancellation of individual titles would not lead to any cost savings. We invite users to carefully check the list on the Library homepage (http://library.cern.ch/). If you find any title that you consider critically important for y...

  10. Coherent Cooper pair tunneling in systems of Josephson junctions: effects of quasiparticle tunneling and of the electromagnetic environment

    NARCIS (Netherlands)

    Maassen van den Brink, A.; Odintsov, A.A.; Bobbert, P.A.; Schön, G.

    1991-01-01

    Small capacitance tunnel junctions show single electron effects and, in the superconducting state, the coherent tunneling of Cooper pairs. We study these effects in a system of two Josephson junctions, driven by a voltage source with a finite impedance. Novel features show up in theI–V

  11. Coherence Effects on the Power and Tower Loads of a 7 × 2 MW Multi-Rotor Wind Turbine System

    Directory of Open Access Journals (Sweden)

    Shigeo Yoshida

    2016-09-01

    Full Text Available A multi-rotor system (MRS, in which multiple wind turbines are placed on one tower, is a promising concept for super-large wind turbines at over 10 MW due to the cost and weight advantages. The coherence effects on an MRS were investigated in this study. Although a wide range of coherences were measured so far, a decay constant of C = 12 is recommended in the IEC61400-1 standard. Dynamic simulations were performed for a 14-MW MRS, which consists of seven 2-MW turbines and includes wind models with three different coherences. Although the results show that a larger coherence increases the output power and the collective loads due to tower base fore-aft bending, it reduces the differential loads due to tower-base torque and tower-top nodding. The most significant case is the fatigue damage due to tower base fore-aft bending, which was more than doubled between the decay constants of C = 6 and C = 12. The present results indicate that the coherence should be defined carefully in the design of large-scale MRSs because its effect on them is not straightforward.

  12. Coherent light scattering of heterogeneous randomly rough films and effective medium in the theory of electromagnetic wave multiple scattering

    Energy Technology Data Exchange (ETDEWEB)

    Berginc, G [THALES, 2 avenue Gay-Lussac 78995 ELANCOURT (France)

    2013-11-30

    We have developed a general formalism based on Green's functions to calculate the coherent electromagnetic field scattered by a random medium with rough boundaries. The approximate expression derived makes it possible to determine the effective permittivity, which is generalised for a layer of an inhomogeneous random medium with different types of particles and bounded with randomly rough interfaces. This effective permittivity describes the coherent propagation of an electromagnetic wave in a random medium with randomly rough boundaries. We have obtained an expression, which contains the Maxwell – Garnett formula at the low-frequency limit, and the Keller formula; the latter has been proved to be in good agreement with experiments for particles whose dimensions are larger than a wavelength. (coherent light scattering)

  13. Cancelable Biometrics - A Survey

    OpenAIRE

    Indira Chakravarthy; VVSSS. Balaram; B. Eswara Reddy

    2011-01-01

    In recent times Biometrics has emerged as a reliable, convenient and effective method of user authentication. However, with the increasing use of biometrics in several diverse applications, concerns about the privacy and security of biometric data contained in the database systems has increased. It is therefore imperative that Biometric systems instill confidence in the general public, by demonstrating that, these systems are robust, have low error rates and are tamper proof. In this context,...

  14. Extending the Effective Ranging Depth of Spectral Domain Optical Coherence Tomography by Spatial Frequency Domain Multiplexing

    Directory of Open Access Journals (Sweden)

    Tong Wu

    2016-11-01

    Full Text Available We present a spatial frequency domain multiplexing method for extending the imaging depth range of a spectral domain optical coherence tomography (SDOCT system without any expensive device. This method uses two galvo scanners with different pivot-offset distances in two independent reference arms for spatial frequency modulation and multiplexing. The spatial frequency contents corresponding to different depth regions of the sample can be shifted to different frequency bands. The spatial frequency domain multiplexing SDOCT system provides an approximately 1.9-fold increase in the effective ranging depth compared with that of a conventional full-range SDOCT system. The reconstructed images of phantom and biological tissue demonstrate the expected increase in ranging depth. The parameters choice criterion for this method is discussed.

  15. Numerical Calculation of Coherent Synchrotron Radiation Effects Using TraFiC4

    International Nuclear Information System (INIS)

    Kabel, Andreas C.

    2000-01-01

    Coherent synchrotron radiation (CSR) occurs when short bunches travel on strongly bent trajectories. Its effects on high-quality beams can be severe and are well understood qualitatively. For quantitative results, however, one has to rely on numerical methods. There exist several simulation codes utilizing different approaches. The authors describe in some detail the code TraFiC 4 developed at DESY for design and analysis purposes, which approaches the problem from first principles and solves the equations of motion either perturbatively or self-consistently. They present some calculational results and comparison with experimental data. Also, they give examples of how the code can be used to design beamlines with minimal emittance growth due to CSR

  16. Skyrmion formation and optical spin-Hall effect in an expanding coherent cloud of indirect excitons.

    Science.gov (United States)

    Vishnevsky, D V; Flayac, H; Nalitov, A V; Solnyshkov, D D; Gippius, N A; Malpuech, G

    2013-06-14

    We provide a theoretical description of the polarization pattern and phase singularities experimentally evidenced recently in a condensate of indirect excitons [H. High et al., Nature 483, 584 (2012)]. We show that the averaging of the electron and hole orbital motion leads to a comparable spin-orbit interaction for both types of carriers. We demonstrate that the interplay between a radial coherent flux of bright indirect excitons and the Dresselhaus spin-orbit interaction results in the formation of spin domains and of topological defects similar to Skyrmions. We reproduce qualitatively all the features of the experimental data and obtain a polarization pattern as in the optical spin-Hall effect despite the different symmetry of the spin-orbit interactions.

  17. Adaptive noise cancellation

    International Nuclear Information System (INIS)

    Rizwan, N.

    1999-01-01

    Wavelet analysis consists of decomposing a signal or an image into a hierarchical set of approximations and details. The levels in the hierarchy correspond to those in a dyadic scale. Wavelet provide an alternative to classical Short Time Fourier Transforms for the analysis of non-stationary signals. Wavelets are defined in continuous time and discrete time. Recently Discrete Wavelet Transform (DWT) had emerged as a popular technique in Image Compression. DWT has high decorrelation and energy compaction efficiency. In this report, the effect of level of decomposition on image compression was studied and results are compared with DCT based image compression. DWT proved better in compression as there was high energy compaction and compressed image was free from blocking artifacts. (author)

  18. Adaptive Feedforward Cancellation of Sinusoidal Disturbances in Superconducting RF Cavities

    CERN Document Server

    Kandil, T H; Hartung, W; Khalil, H; Popielarski, J; Vincent, J; York, R C

    2004-01-01

    A control method, known as adaptive feedforward cancellation (AFC) is applied to damp sinusoidal disturbances due to microphonics in superconducting RF (SRF) cavities. AFC provides a method for damping internal, and external sinusoidal disturbances with known frequencies. It is preferred over other schemes because it uses rudimentary information about the frequency response at the disturbance frequencies, without the necessity of knowing an analytic model (transfer function) of the system. It estimates the magnitude and phase of the sinusoidal disturbance inputs and generates a control signal to cancel their effect. AFC, along with a frequency estimation process, is shown to be very successful in the cancellation of sinusoidal signals from different sources. The results of this research may significantly reduce the power requirements and increase the stability for lightly loaded continuous-wave SRF systems.

  19. Measurement of observables sensitive to coherence effects in hadronic Z decays with the OPAL detector at LEP

    CERN Document Server

    Fischer, Nadine; Kluth, Stefan; Plätzer, Simon; Skands, Peter

    2015-01-01

    A study of QCD coherence is presented based on a sample of about 397000 $e^+e^-$ hadronic annihilation events collected at $\\sqrt{s}=91$ GeV with the OPAL detector at LEP. The study is based on four recently proposed observables that are sensitive to coherence effects in the perturbative regime. The measurement of these observables is presented, along with a comparison with the predictions of different parton shower models. The models include both conventional parton shower models and dipole antenna models. Different ordering variables are used to investigate their influence on the predictions.

  20. Coherent effects on two-photon correlation and directional emission of two two-level atoms

    International Nuclear Information System (INIS)

    Ooi, C. H. Raymond; Kim, Byung-Gyu; Lee, Hai-Woong

    2007-01-01

    Sub- and superradiant dynamics of spontaneously decaying atoms are manifestations of collective many-body systems. We study the internal dynamics and the radiation properties of two atoms in free space. Interesting results are obtained when the atoms are separated by less than half a wavelength of the atomic transition, where the dipole-dipole interaction gives rise to new coherent effects, such as (a) coherence between two intermediate collective states, (b) oscillations in the two-photon correlation G (2) , (c) emission of two photons by one atom, and (d) the loss of directional correlation. We compare the population dynamics during the two-photon emission process with the dynamics of single-photon emission in the cases of a Λ and a V scheme. We compute the temporal correlation and angular correlation of two successively emitted photons using the G (2) for different values of atomic separation. We find antibunching when the atomic separation is a quarter wavelength λ/4. Oscillations in the temporal correlation provide a useful feature for measuring subwavelength atomic separation. Strong directional correlation between two emitted photons is found for atomic separation larger than a wavelength. We also compare the directionality of a photon spontaneously emitted by the two atoms prepared in phased-symmetric and phased-antisymmetric entangled states vertical bar ±> k 0 =e ik 0 ·r 1 vertical bar a 1 ,b 2 >±e ik 0 ·r 2 vertical bar b 1 ,a 2 > by a laser pulse with wave vector k 0 . Photon emission is directionally suppressed along k 0 for the phased-antisymmetric state. The directionality ceases for interatomic distances less than λ/2

  1. Effects of moderate pump and Stokes chirp on chirped-probe pulse femtosecond coherent anti-Stokes Raman scattering thermometry

    KAUST Repository

    Gu, Mingming; Satija, Aman; Lucht, Robert P.

    2018-01-01

    The effects of moderate levels of chirp in the pump and Stokes pulses on chirped-probe-pulse femtosecond coherent anti-Stokes Raman scattering (CPP fs CARS) were investigated. The frequency chirp in the pump and Stokes pulses was introduced

  2. Study of Cancelled Elective Surgical Operations

    Directory of Open Access Journals (Sweden)

    M Amrollahi

    2004-07-01

    Full Text Available Introduction: Cancellation of an elective operation is a very important problem, which is the cause for different types of stresses for patients and their families and results in loss of significant amount of time, money and hospital resources. Therefore, finding the main causes of operation postponement may help us to understand and reduce these problems. Material & Method: A special questionnaire was designed to gather information about different causes of operation cancellation and filled from October 23rd (Aban 1st till November 21st (Azar 30 th, 2001 (1380 in all of the teaching hospitals of Yazd university. (S.Dr Rahnemoon, Afshar, Rah Ahan, Bahman and Savaneg Sukhteghy Results were statistically evaluated.. Results: 180 of the 31437 scheduled operations had been cancelled (12.52% Majority of cases (33.3% had been cancelled due to the absence of the surgeons. This group ((Surgeons absent was the most common cause for the postponement of operations (36.7%. The secondary cause of cancellations was related to anesthetic team and operating room problems (25%, the patient’s reasons for cancellation was 16.2% and the most minimal cause of cancellation was insufficient hospital revenue (0.5%. The basis of disease or high risk patients for operation were the main causes of dysfunction of the anesthetic team (68.9% and also the first cause of cancellation. The rate of cancellation was the most in the "older than 60 years" age group. (15.4% The cancellation in women was 12.6% and in males 12.5%. Conclusion: Surgeons schedule more patients keeping in mind cancellations which occur regularly due to patients, hospital, anesthesia, and operating room problems. This over scheduling is a problem itself, so preadmission evaluation clinics are recommended to decrease the rate of cancellations thereby saving the socioeconomic resources and decreasing patient’s stress.

  3. Using Comics to Communicate Legal Contract Cancellation

    OpenAIRE

    Marietjie Botes

    2017-01-01

    This article investigates how comics can be used to adequately communicate the correct process of contract cancellation and whether comics can enhance understanding of the legal process. A survey of pre-owned vehicle buyers of various levels of education in Pretoria, South Africa found that when comics are used to communicate contract cancellation, a significant increase in the comprehension of the legal cancellation process occurs. The results may influence how contracting parties may choose...

  4. Misconceptions regarding the cancellation of self-forces in the transverse equation of motion for an electron in a bunch

    International Nuclear Information System (INIS)

    Geloni, G.; Yurkov, M.V.

    2003-10-01

    As a consequence of motions driven by external forces, self-fields originate within an electron bunch, which are different from the static case. In the case of magnetic external forces acting on an ultrarelativistic beam, the longitudinal self-interactions are responsible for CSR (coherent synchrotron radiation)-related phenomena, which have been studied extensively. On the other hand, transverse self-interactions are present too. At the time being, several existing theoretical analysis of transverse dynamics rely on the so-called cancellation effect, which has been around for more than ten years. In this paper we explain why in our view such an effect is not of practical nor of theoretical importance. (orig.)

  5. Bullying victimization prevalence and its effects on psychosomatic complaints: can sense of coherence make a difference?

    Science.gov (United States)

    García-Moya, Irene; Suominen, Sakari; Moreno, Carmen

    2014-10-01

    The aim of this study was to examine the prevalence of bullying victimization and its impact on physical and psychological complaints in a representative sample of adolescents and to explore the role of sense of coherence (SOC) in victimization prevalence and consequences. A representative sample of Spanish adolescents (N = 7580, mean age = 15.41) was selected as part of the Health Behaviour in School-aged Children study. Bullying victimization, physical and psychological symptoms, and SOC were measured, and comparisons were made between strong- and weak-SOC adolescents regarding their likelihood of being a victim of bullying and the negative effects of bullying victimization on their health. Weak-SOC adolescents were significantly more likely to suffer from bullying victimization regardless of type (nonphysical vs physical and nonphysical) or means (traditional vs cyberbullying). In addition, bullying victimization showed significant increasing effects on weak-SOC adolescents' physical and psychological symptoms whereas in strong-SOC adolescents it was not significantly associated with increases in physical complaints and its effects on psychological complaints seemed to be weaker. Weak-SOC adolescents seem to be at higher risk of becoming bullying victims and victimization experiences appear to have increased negative effects on them when compared to strong-SOC students. © 2014, American School Health Association.

  6. Vocal Noise Cancellation From Respiratory Sounds

    National Research Council Canada - National Science Library

    Moussavi, Zahra

    2001-01-01

    Although background noise cancellation for speech or electrocardiographic recording is well established, however when the background noise contains vocal noises and the main signal is a breath sound...

  7. 34 CFR 674.59 - Cancellation for military service.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Cancellation for military service. 674.59 Section 674... Cancellation for military service. (a) Cancellation on a Defense loan. (1) An institution must cancel up to 50... cancellation rate is 121/2 percent of the original loan principal, plus the interest on the unpaid balance...

  8. Towards an understanding of the mechanisms of weak central coherence effects: experiments in visual configural learning and auditory perception.

    Science.gov (United States)

    Plaisted, Kate; Saksida, Lisa; Alcántara, José; Weisblatt, Emma

    2003-01-01

    The weak central coherence hypothesis of Frith is one of the most prominent theories concerning the abnormal performance of individuals with autism on tasks that involve local and global processing. Individuals with autism often outperform matched nonautistic individuals on tasks in which success depends upon processing of local features, and underperform on tasks that require global processing. We review those studies that have been unable to identify the locus of the mechanisms that may be responsible for weak central coherence effects and those that show that local processing is enhanced in autism but not at the expense of global processing. In the light of these studies, we propose that the mechanisms which can give rise to 'weak central coherence' effects may be perceptual. More specifically, we propose that perception operates to enhance the representation of individual perceptual features but that this does not impact adversely on representations that involve integration of features. This proposal was supported in the two experiments we report on configural and feature discrimination learning in high-functioning children with autism. We also examined processes of perception directly, in an auditory filtering task which measured the width of auditory filters in individuals with autism and found that the width of auditory filters in autism were abnormally broad. We consider the implications of these findings for perceptual theories of the mechanisms underpinning weak central coherence effects. PMID:12639334

  9. Sense of coherence modifies the effect of overtime work on mental health.

    Science.gov (United States)

    Ohta, Masanori; Higuchi, Yoshiyuki; Yamato, Hiroshi; Kumashiro, Masaharu; Sugimura, Hisamichi

    2015-01-01

    In the occupational health field, it is important to know how workload influences mental health. Overtime work and job strain appear to affect the mental health status of workers. Sense of coherence (SOC) may mediate the relationship between work stress and mental health. Since SOC represents a personal ability to manage psychological stressors, we hypothesized that a strong SOC would modify the adverse effect of an objective measure of overtime work on mental health. A total of 1,558 Japanese workers employed in an information technology company were asked to complete a 3-item SOC Questionnaire and 28-item General Health Questionnaire (GHQ) to assess mental health status. Workload was assessed by the actual amount of overtime work hours recorded by the company. Multiple regression analysis revealed a main effect of overtime work (β=0.08, p=0.0003) and SOC scores (β=0.41, p work and SOC scores (β=0.05, p=0.051). Simple slope analysis supported this association (-1 SD below the mean, simple slope=0.04, SE=0.01, p health impacts of workload as measured by an objective index of overtime work, and should be considered when assessing the effects of workload on mental health.

  10. Newtonian-noise cancellation in large-scale interferometric GW detectors using seismic tiltmeters

    International Nuclear Information System (INIS)

    Harms, Jan; Venkateswara, Krishna

    2016-01-01

    The mitigation of terrestrial gravity noise, also known as Newtonian noise (NN), is one of the foremost challenges to improve low-frequency sensitivity of ground-based gravitational-wave detectors. At frequencies above 1 Hz, it is predicted that gravity noise from seismic surface Rayleigh waves is the dominant contribution to NN in surface detectors, and may still contribute significantly in future underground detectors. Noise cancellation based on a coherent estimate of NN using data from a seismometer array was proposed in the past. In this article, we propose an alternative scheme to cancel NN using a seismic tiltmeter. It is shown that even under pessimistic assumptions concerning the complexity of the seismic field, a single tiltmeter under each test mass of the detector is sufficient to achieve substantial noise cancellation. A technical tiltmeter design is presented to achieve the required sensitivity in the Newtonian-noise frequency band. (paper)

  11. Multiple Interference Cancellation Performance for GPS Receivers with Dual-Polarized Antenna Arrays

    Directory of Open Access Journals (Sweden)

    Moeness G. Amin

    2008-11-01

    Full Text Available This paper examines the interference cancellation performance in global positioning system (GPS receivers equipped with dual-polarized antenna arrays. In dense jamming environment, different types of interferers can be mitigated by the dual-polarized antennas, either acting individually or in conjunction with other receiver antennas. We apply minimum variance distorntionless response (MVDR method to a uniform circular dual-polarized antenna array. The MVDR beamformer is constructed for each satellite. Analysis of the eigenstructures of the covariance matrix and the corresponding weight vector polarization characteristics are provided. Depending on the number of jammers and jammer polarizations, the array chooses to expend its degrees of freedom to counter the jammer polarization or/and use phase coherence to form jammer spatial nulls. Results of interference cancellations demonstrate that applying multiple MVDR beamformers, each for one satellite, has a superior cancellation performance compared to using only one MVDR beamformer for all satellites in the field of view.

  12. Reasons for cancellation of elective surgery in Ilorin | Kolawole ...

    African Journals Online (AJOL)

    Background: The rising cost of health care and dwindling economic resources necessitate the need to encourage cost-effectiveness in patient care. Cancellation of cases on the scheduled day of surgery leads to inefficient utilization of theatre space, waste of valuable manpower and scarce resources for patients and ...

  13. Cosserat moduli of anisotropic cancellous bone : A micromechanical analysis

    NARCIS (Netherlands)

    Fatemi, J.; Onck, P.R.; Poort, G.; Van Keulen, F.

    A micromechanical-based approach is proposed to quantify the effective (in the macroscopic sense) elastic constants of Cosserat materials. The material under investigation (cancellous bone) is cellular and classically elastic at the microscopic level and assumed to be dense Cosserat elastic at the

  14. 30 CFR 250.181 - When may the Secretary cancel my lease and when am I compensated for cancellation?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may the Secretary cancel my lease and when... may the Secretary cancel my lease and when am I compensated for cancellation? If the Secretary cancels.... Section 250.185 states conditions under which you will receive no compensation. The Secretary may cancel a...

  15. The effect of an accretion disk on coherent pulsed emission from weakly magnetized neutron stars

    International Nuclear Information System (INIS)

    Asaoka, Ikuko; Hoshi, Reiun.

    1989-01-01

    Using a simple model for hot spots formed on the magnetic polar regions we calculate the X-ray pulse profiles expected from bright low-mass X-ray binaries. We assume that neutron stars in close binary systems are surrounded by accretion disks extending down in the vicinity of their surfaces. Even partial eclipses of a hot spot by the accretion disk change the coherent pulsed fraction and, in some cases, the phase of pulsations by almost 180deg. Coherent pulsations are clearly seen even for sufficiently compact model neutron stars, if the hot spots emit isotropic or fan-beam radiation. In the case of pencil-beam radiation, coherent pulsations are also seen if the cap-opening angle is less than ∼60deg, while the inclination angle is larger than 68deg. Gravitational lensing alone does not smear coherent pulsations in moderately weak magnetized neutron stars in the presence of an absorbing accretion disk. (author)

  16. Individual differences in processing coherence markers: the effect of metacognitive knowledge

    NARCIS (Netherlands)

    Vlaar, M.A.J.|info:eu-repo/dai/nl/412585669; Sanders, T.J.M.|info:eu-repo/dai/nl/075243911; Welie, Camille

    2017-01-01

    Coherence markers such as connectives positively influence the reading process and reading comprehension for most, but not all, readers. Metacognitive knowledge, concerning strategies to regulate the reading process, may explain these individual differences. We investigated how metacognitive

  17. The effectiveness of optical coherence tomography for evaluating peri-omplant tissue: A pilot study

    International Nuclear Information System (INIS)

    Sanda, Minoru; Shiota, Makoto; Imakita, Chiharu; Kasugai, Shohei; Sakuyama, Aoi; Sumi, Yasunori

    2016-01-01

    Optical coherence tomography (OCT) has been investigated as a novel diagnostic imaging tool. The utilisation of this equipment has been evaluated through several studies in the field of dentistry. The aim of this preliminary study was to determine through basic experiments the effectiveness of OCT in implant dentistry. To assess detection ability, we captured OCT images of implants in each of the following situations: (1) implants covered with mucosae of various thicknesses that were harvested from the mandibles of pigs; (2) implants installed in the mandibles of pigs; and (3) implants with abutments and crowns fixed with temporary cement. The OCT images were captured before cementation, after cementation, and after removing the excess submucosal cement. If the thickness of the mucosa covering the implant body was less than 1 mm, the images of the implants were clearly detected by OCT. In the implants were installed in pigs' mandibles, it was difficult to capture clear images of the implant and alveolar bone in most of the samples. Remnants of excess cement around the implants were visible in most samples that had a mucosa thickness of less than 3 mm. Currently, OCT imaging of implants is limited. Cement remnants at the submucosal area can be detected in some cases, which can be helpful in preventing peri-implant diseases. Still, though there are some restrictions to its application, OCT could have potential as an effective diagnostic instrument in the field of implant dentistry as well

  18. The effectiveness of optical coherence tomography for evaluating peri-omplant tissue: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Sanda, Minoru; Shiota, Makoto; Imakita, Chiharu; Kasugai, Shohei [Dept. of Oral Implantology and Regenerative Dental Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Sakuyama, Aoi [Dept. of Oral Surgery, Jichii Medical University Hospital, Tochigi (Japan); Sumi, Yasunori [Div. of Oral and Dental Surgery, Dept. of Advanced Medicine, National Hospital for Geriatric Medicine, National Center for Geriatrics and Gerontology, Obu (Japan)

    2016-09-15

    Optical coherence tomography (OCT) has been investigated as a novel diagnostic imaging tool. The utilisation of this equipment has been evaluated through several studies in the field of dentistry. The aim of this preliminary study was to determine through basic experiments the effectiveness of OCT in implant dentistry. To assess detection ability, we captured OCT images of implants in each of the following situations: (1) implants covered with mucosae of various thicknesses that were harvested from the mandibles of pigs; (2) implants installed in the mandibles of pigs; and (3) implants with abutments and crowns fixed with temporary cement. The OCT images were captured before cementation, after cementation, and after removing the excess submucosal cement. If the thickness of the mucosa covering the implant body was less than 1 mm, the images of the implants were clearly detected by OCT. In the implants were installed in pigs' mandibles, it was difficult to capture clear images of the implant and alveolar bone in most of the samples. Remnants of excess cement around the implants were visible in most samples that had a mucosa thickness of less than 3 mm. Currently, OCT imaging of implants is limited. Cement remnants at the submucosal area can be detected in some cases, which can be helpful in preventing peri-implant diseases. Still, though there are some restrictions to its application, OCT could have potential as an effective diagnostic instrument in the field of implant dentistry as well.

  19. Modeled and Measured Partially Coherent Illumination Speckle Effects from Sloped Surfaces for Tactical Tracking

    Science.gov (United States)

    2015-03-26

    the number of speckle samples obtained, laser power and coherence length, spot size, target reflectance, speckle size, and pixels per speckle width...gated imaging systems,” Proc. SPIE, 6542: 654218, April 2007. 90 St. Pierre, Randall J. and others. “Active Tracker Laser (ATLAS),” IEEE J. Sel...numerical model developed here and existing theory developed by Hu. A 671 nm diode laser source with coherence length of 259 +/- 7 µm is reflected

  20. A computer simulation of an adaptive noise canceler with a single input

    Science.gov (United States)

    Albert, Stuart D.

    1991-06-01

    A description of an adaptive noise canceler using Widrows' LMS algorithm is presented. A computer simulation of canceler performance (adaptive convergence time and frequency transfer function) was written for use as a design tool. The simulations, assumptions, and input parameters are described in detail. The simulation is used in a design example to predict the performance of an adaptive noise canceler in the simultaneous presence of both strong and weak narrow-band signals (a cosited frequency hopping radio scenario). On the basis of the simulation results, it is concluded that the simulation is suitable for use as an adaptive noise canceler design tool; i.e., it can be used to evaluate the effect of design parameter changes on canceler performance.

  1. A Dual Decomposition Approach to Partial Crosstalk Cancelation in a Multiuser DMT-xDSL Environment

    Directory of Open Access Journals (Sweden)

    Verlinden Jan

    2007-01-01

    Full Text Available In modern DSL systems, far-end crosstalk is a major source of performance degradation. Crosstalk cancelation schemes have been proposed to mitigate the effect of crosstalk. However, the complexity of crosstalk cancelation grows with the square of the number of lines in the binder. Fortunately, most of the crosstalk originates from a limited number of lines and, for DMT-based xDSL systems, on a limited number of tones. As a result, a fraction of the complexity of full crosstalk cancelation suffices to cancel most of the crosstalk. The challenge is then to determine which crosstalk to cancel on which tones, given a complexity constraint. This paper presents an algorithm based on a dual decomposition to optimally solve this problem. The proposed algorithm naturally incorporates rate constraints and the complexity of the algorithm compares favorably to a known resource allocation algorithm, where a multiuser extension is made to incorporate the rate constraints.

  2. Evaluation of State-of-the-Art Acoustic Feedback Cancellation Systems for Hearing Aids

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2013-01-01

    This research evaluates four state-of-the-art acoustic feedback cancellation systems in hearing aids in terms of the cancellation performance, sound quality degradation, and computational complexity. The authors compared a traditional full-band system to a system with a prediction error method...... in a full band, a subband system, a subband system with frequency shifting, and a recently proposed subband system with a novel probe noise deployment. All systems outperformed the traditional full-band system in cancellation performance, especially the subband system with probe noise is most effective...... for cancellation. However, in all cases there was a trade-off between performance and computational cost. With a 3-times increase in computation load, the probe noise based cancellation system can be realized that functions even in the most challenging feedback situation....

  3. Noise canceling in-situ detection

    Science.gov (United States)

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  4. Surgery cancellations at a public hospital

    Directory of Open Access Journals (Sweden)

    Erika Pittelkow

    2008-12-01

    Full Text Available Objective: To determine the frequency of cancellation of scheduledsurgeries at a public hospital in the city of São Paulo, and to identifythe reasons of cancellation. Methods: A descriptive, exploratory,retrospective study, with quantitative analysis, of records ofprocedures cancelled and medical charts of patients whose surgerieswere cancelled, between January 2006 and July 2007. Results: Ofthe 6,149 (100% surgeries scheduled for the period surveyed, 701(11.4% were canceled and 5,448 (88.6% conducted; among thesurgeries cancelled, most were general surgeries (237/33.8% andorthopedic surgery (200/28.5%; surgeons or assistant surgeons(518/73.9% and anesthesiologists (183/26.1% were responsible forcancellations. The primary reasons for cancellation were unfavorableclinical status of patients (225/32.1%, no show up of patients(119/17.0%, change in medical management (79/11.3%, patientnot appropriately prepared (53/7.5% and lack of material (52/7.4%.Conclusions: This study enabled identifying the frequency and causesof surgical cancellations at a public hospital, so as to contribute toimproving professional performance in this area.

  5. Effects of food web structure and resource subsidies on the patterns and mechanisms of temporal coherence in a tropical coastal lagoon: an experimental mesocosm approach

    Directory of Open Access Journals (Sweden)

    Luciana Silva Carneiro

    Full Text Available AIM: The study of the patterns and mechanisms of temporal coherence of ecological variables among lakes has become an important area of limnology. However, no study to date has experimentally tested whether and how resource subsidies and food web configuration affect the patterns and mechanisms of temporal coherence of limnological variables. We conducted a field mesocosm experiment to test the following hypotheses: (i nutrient enrichment would reduce the temporal coherence of system variables; (ii fish predation would enhance the temporal coherence of system variables; and (iii the strength of temporal coherence decreases from physical (water transparency, to chemical (dissolved oxygen concentration [DO] to biological variables (total zooplankton biomass. METHODS: For 11 weeks, we manipulated fish presence and nutrient (N and P concentration in a 2 × 2 factorial design in sixteen within-lake enclosures installed in a tropical coastal lagoon. Coherence was estimated by pair-to-pair Pearson's moment correlations of the temporal trajectories of each response variable among enclosures of the same treatment. RESULTS: Fish presence only enhanced the temporal coherence of zooplankton biomass, whereas contrary to our expectations, nutrient addition enhanced the temporal coherence of [DO]. The strength of the individual effects of fish and nutrients on temporal coherence was affected by variable identity, but this variation did not occur in a consistent pattern across variables. However, the interactive effects of fish and nutrients on the temporal coherence of the three variables monitored were not statistically significant. CONCLUSIONS: Our results indicate that local factors, such as fish presence and nutrient availability, may affect the temporal coherence of several system variables, but these effects are better predicted by the strength of direct interactions between the local factor and the variable than by the identity of the variable itself

  6. Analysis of photodynamic cream effect in dental caries using optical coherence tomography

    Science.gov (United States)

    Barbosa, P. S.; Freitas, A. Z.; de Sant´Anna, G. R.

    2015-06-01

    The aim of this study was to assess the effect in the enamel demineralization of low-intensity infrared laser (λ=810 nm, 100 mW/cm2, 90 sec, 4.47 J/cm2, 9 J) with or without photodynamic cream fluorinated or not fluorinated, using Optical Coherence Tomography (OCT). Background data: Lasers can be used as tools for the prevention of tooth enamel demineralization. All enamel specimens (n= 105) were analyzed using OCT at baseline, and randomly assigned into seven groups (n=15): C (+), laser application; C(-), no treatment; (F), acid fluoride gel; cream (IV); cream and neutral fluoride (IVF); cream and laser (IVL); and cream with neutral fluoride+ laser (IVFL). The specimens were submitted to all kind of treatments before demineralizing pH cycling challenge and were reanalyzed. ANOVA and Tukey's multiple comparative analysis (p <0.01) demonstrated a greater delta attenuation between baseline and post challenge for C + (0.034 +/- 0.011) compared to IVF (0.016 +/- 0.007) F (0.018 +/- 0.010) IVFL (0.019 +/- 0.008), and IVL (0.014 +/- 0.010). The cream laser group (IVL) also showed lower delta (0.014 +/- 0.010) compared to C - (0.025 +/- 0.008). The OCT technique demonstrated that cream associated with laser showed the lowest quantitative enamel mineral looses after cariogenic challenge.

  7. Optical coherence tomography of the effects of stromal hydration on clear corneal incision architecture.

    Science.gov (United States)

    Calladine, Daniel; Tanner, Vaughan

    2009-08-01

    To evaluate the effects of stromal hydration on clear corneal incision (CCI) architecture immediately after surgery using anterior segment optical coherence tomography (AS-OCT). Department of Ophthalmology, Royal Berkshire Hospital, Reading, United Kingdom. Clear corneal incisions in adult eyes were examined using a Visante AS-OCT imaging system within 1 hour of surgery. Half the CCIs had stromal hydration with a balanced salt solution and half did not. Incisions were made with a 2.75 mm steel keratome. Intraocular pressure (IOP) was measured within 90 minutes after surgery. The CCI length and corneal thickness at the CCI site were measured using software built into the AS-OCT system. Thirty CCIs were evaluated. Stromal hydration significantly increased the measured CCI length (Pthe result of a trend toward increased corneal thickness at the CCI site with hydration (PThe mean CCI length was 1.69 mm +/- 0.27 (SD) (range 1.31 to 2.32 mm) with hydration and 1.51 +/- 0.23 mm (range 1.30 to 1.95 mm) without hydration. The mean IOP was 20.9 +/- 8.18 mm Hg and 15.8 +/- 8.20 mm Hg, respectively. The IOP tended to be higher with hydration (Pthe eye with a higher early postoperative IOP, showing the importance of taking stromal hydration into account when designing similar OCT studies of CCI architecture.

  8. Compressibility effect on thermal coherent structures in spatially-developing turbulent boundary layers via DNS

    Science.gov (United States)

    Araya, Guillermo; Jansen, Kenneth

    2017-11-01

    DNS of compressible spatially-developing turbulent boundary layers is performed at a Mach number of 2.5 over an isothermal flat plate. Turbulent inflow information is generated by following the concept of the rescaling-recycling approach introduced by Lund et al. (J. Comp. Phys. 140, 233-258, 1998); although, the proposed methodology is extended to compressible flows. Furthermore, a dynamic approach is employed to connect the friction velocities at the inlet and recycle stations (i.e., there is no need of an empirical correlation as in Lund et al.). Additionally, the Morkovin's Strong Reynolds Analogy (SRA) is used in the rescaling process of the thermal fluctuations from the recycle plane. Low/high order flow statistics is compared with direct simulations of an incompressible isothermal ZPG boundary layer at similar Reynolds numbers and temperature regarded as a passive scalar. Focus is given to the effect assessment of flow compressibility on the dynamics of thermal coherent structures. AFOSR #FA9550-17-1-0051.

  9. Effect of dielectric medium on the nonclassical properties of nonlinear sphere coherent states

    Directory of Open Access Journals (Sweden)

    E Amooghorban

    2014-04-01

    Full Text Available In order to investigate the effect of a medium with dissipation and dispersion and also the curvature of the physical space on the properties of the incident quantum states, we use the quantization of electromagnetic field based on phenomenological approach to obtain input-output relations between radiations on both sides of dielectric slab. By using these relations the fidelity, the Wigner function, and also the quantum correlation of the outgoing state through dielectric slab are obtained for a situation in which the rightward incident state is a nonlinear coherent state on a sphere and the leftward incident state is a vacuum state. Here, the incident states are considered monochromatic and the modeling of the medium is given by the Lorentz' model. Accordingly, we study nonclassical properties of the output states such as the quantum entanglement. It will be observed that the nonclassical properties of the outgoing states depend strongly on the optical property of the medium and also on the curvature of the physical state.

  10. Effect of fibrinogen on blood coagulation detected by optical coherence tomography

    International Nuclear Information System (INIS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-01-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d 1/e ) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d 1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0–8 g L −1 ); and 2) native plasma with commercial Fbg added (0–8 g L −1 ). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels. (paper)

  11. Optical Coherence and Quantum Optics

    CERN Document Server

    Mandel, Leonard

    1995-01-01

    This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topi

  12. Coherent Structure Dynamics and Turbulent Effects of Horizontal Axis Marine Energy Devices

    Science.gov (United States)

    Gajardo, D. I.; Escauriaza, C. R.; Ingram, D.

    2016-12-01

    Harnessing the energy available in the oceans constitutes one of the most promising alternatives for generating clean electricity. There are vast amounts of energy present both in waves and tidal currents so it is anticipated that marine energy will have a major role in non-conventional renewable energy generation in the near to mid future. Nevertheless, before marine hydrokinetic (MHK) devices can be installed in large numbers a better understanding of the physical, social and environmental implications of their operation is needed. This includes understanding the: hydrodynamic processes, interaction with bathymetry, and the local flow characteristics. This study is focused on the effects horizontal axis MHK devices have on flow turbulence and coherent structures. This is especially relevant considering that sites with favourable conditions for MHK devices are tidal channels where a delicate balance exists between the strong tidal currents and the ecosystems. Understanding how MHK devices influence flow conditions, turbulence and energy flux is essential for predicting and assessing the environmental implications of deploying MHK technologies. We couple a Blade Element Momentum Actuator Disk (BEM-AD) model to a Detached Eddy Simulation (DES) flow solver in order to study flow conditions for different configurations of horizontal axis MHK turbines. In this study, we contribute to the understanding of the hydrodynamic behaviour of MHK technologies, and give insights into the effects devices will have on their environment, with emphasis in ambient turbulence and flow characteristics, while keeping in mind that these effects can alter electricity quality and device performance. Work supported by CONICYT grant 80160084, Fondecyt grant 1130940, Chile's Marine Energy Research & Innovation Center (MERIC) CORFO project 14CEI2-28228, and the collaboration between the Pontificia Universidad Católica de Chile and the University of Edinburgh, UK, partially supported by the RC

  13. Influence of temporal–spectral effects on ultrafast fiber coherent polarization beam combining system

    International Nuclear Information System (INIS)

    Yu, H L; Ma, P F; Wang, X L; Su, R T; Zhou, P; Chen, J B

    2015-01-01

    The active coherent polarization beam combining (CPBC) technique has been experimentally proved to be a promising approach for the energy and power scaling of ultrashort laser pulses, despite the tremendous challenge in temporal synchronization, dispersion management and nonlinearity control. In order to develop a comprehensive theoretical model to investigate the influence of temporal–spectral effects on ultrafast fiber active CPBC systems, a generalized nonlinear Schrödinger equation carrying spectral factors is used to depict the propagation of ultrashort pulses in fiber amplifier channels and ultrashort-pulsed Gaussian beams (PGBs) carrying temporal–spatial factors are utilized to picture the propagation of ultrashort pulses in the free space. To the best of our knowledge, the influence of different temporal–spectral effects has been segregated for the first time and corresponding analytical equations have been strictly derived to link the combining efficiency with specific factors. Based on our analysis, the optical path difference (OPD) has the most detrimental impact on the combining efficiency because of the high controlling accuracy and anti-interference requirements. For instance, the OPD must be controlled in ∼  ±14 μm to achieve a combining efficiency of above 95% for combining ultrashort laser pulses with a 3 dB spectral bandwidth of 13 nm centered at 1064 nm. Besides, the analytical expression also demonstrates that the impact of self-phase modulation on the combining efficiency has no dependence on spectral bandwidth and only depends on the B integral difference if neglecting the direct influence of the peak power difference. Our analysis also indicates that the group velocity dispersion has relatively small influence on the combining efficiency. These formulas can be used to diagnose the influence of temporal–spectral effects and provide useful guidelines for the design or optimization of the active CPBC system of ultrafast

  14. Imperfect generalized transmit beamforming with co-channel interference cancelation

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2010-10-01

    The performance of a generalized single-stream transmit beamforming scheme employing receive co-channel interference -steering algorithms in slowly varying and flat fading channels is analyzed. The impact of imperfect prediction of channel state information (CSI) for the desired user spatially uncorrelated transmit channels is considered. Both dominant interference cancelation and adaptive arbitrary interference cancelation algorithms for closely spaced receive antennas are used. The impact of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact formulas for the statistics of combined signal-to-interference-plus-noise ratio (SINR) are derived, from which results for conventional maximum ratio transmission (MRT) and best transmit channel selection schemes can be deduced as limiting cases. The results presented herein can be used to obtain quantitative measure for various performance metrics, and in addition to investigate the performance-complexity tradeoff for different multiple-antenna system models. © 2010 IEEE.

  15. Putting a face and context on pediatric surgery cancelations: The development of parent personas to guide equitable surgical care.

    Science.gov (United States)

    Vaughn, Lisa M; DeJonckheere, Melissa; Pratap, Jayant Nick

    2016-06-09

    Last-minute cancelation of planned surgery can have substantial psychological, social, and economic effects for patients/families and also leads to wastage of expensive health-care resources. In order to have a deeper understanding of the contextual, psychological, practical, and behavioral factors that potentially impact pediatric surgery cancelation, we conducted a qualitative study to create 'personas' or fictional portraits of parents who are likely to cancel surgery. We conducted in-depth qualitative interviews with 21 parents of children who were considered 'at risk' for surgical cancelation and whose scheduled surgery was canceled at late notice. From the themes, patterns, and associated descriptive phrases in the data, we developed and validated five different personas of typical scenarios reflecting parent experiences with surgery and surgery cancelations. The personas are being employed to guide contextualized development of interventions tailored to prototypical families as they prepare and attend for surgery. © The Author(s) 2016.

  16. On the construction of coherent states of position dependent mass Schroedinger equation endowed with effective potential

    International Nuclear Information System (INIS)

    Chithiika Ruby, V.; Senthilvelan, M.

    2010-01-01

    In this paper, we propose an algorithm to construct coherent states for an exactly solvable position dependent mass Schroedinger equation. We use point canonical transformation method and obtain ground state eigenfunction of the position dependent mass Schroedinger equation. We fix the ladder operators in the deformed form and obtain explicit expression of the deformed superpotential in terms of mass distribution and its derivative. We also prove that these deformed operators lead to minimum uncertainty relations. Further, we illustrate our algorithm with two examples, in which the coherent states given for the second example are new.

  17. Effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Mohana Kuppuswamy Parthasarathy

    2015-01-01

    Full Text Available Aim: The aim of the present study was to study the effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography (OCT. Materials and Methods: One hundred and fifty-one subjects were included from the normative study of foveal morphology carried out at our hospital. Subjects underwent comprehensive eye examination and macular scanning using Cirrus high-definition OCT and axial length (AXL measurement. Macular cube 512 × 128 scan protocol was used for scanning the macula. Automated measurements of the fovea namely foveal diameter, foveal slope (lateral measurements and foveal depth (axial measurement were taken. A correction factor for ocular magnification was done using the formula t = p × q × s, where "t0" is the corrected measurement, "p" is the magnification of OCT, "q0" is the ocular magnification, and "s" is the measurement on OCT without correction. The difference between corrected and uncorrected measurements was evaluated for statistical significance. Results: Mean AXL was 22.95 ± 0.78 mm. Refractive error ranged from −3D to +4D. Mean difference between measured and corrected foveal diameter, slope and depth was 166.05 ± 95.37 ΅m (P < 0.001, 0.81° ± 0.53° (P < 0.001 and 0.05 ± 0.49 ΅m (P = 0.178 respectively. AXL lesser than the OCT calibrated value of 24.46 mm showed an increased foveal diameter (r = 0.961, P < 0.001 and a reduced foveal slope (r = −0.863, P < 0.001 than the corrected value. Conclusion: Lateral measurements made on OCT varied with AXL s other than the OCT calibrated value of 24.46 mm. Therefore, to estimate the actual dimensions of a retinal lesion using OCT, especially lateral dimensions, we recommend correction for the ocular magnification factor.

  18. Visualization of Radial Peripapillary Capillaries Using Optical Coherence Tomography Angiography: The Effect of Image Averaging.

    Directory of Open Access Journals (Sweden)

    Shelley Mo

    Full Text Available To assess the effect of image registration and averaging on the visualization and quantification of the radial peripapillary capillary (RPC network on optical coherence tomography angiography (OCTA.Twenty-two healthy controls were imaged with a commercial OCTA system (AngioVue, Optovue, Inc.. Ten 10x10° scans of the optic disc were obtained, and the most superficial layer (50-μm slab extending from the inner limiting membrane was extracted for analysis. Rigid registration was achieved using ImageJ, and averaging of each 2 to 10 frames was performed in five ~2x2° regions of interest (ROI located 1° from the optic disc margin. The ROI were automatically skeletonized. Signal-to-noise ratio (SNR, number of endpoints and mean capillary length from the skeleton, capillary density, and mean intercapillary distance (ICD were measured for the reference and each averaged ROI. Repeated measures analysis of variance was used to assess statistical significance. Three patients with primary open angle glaucoma were also imaged to compare RPC density to controls.Qualitatively, vessels appeared smoother and closer to histologic descriptions with increasing number of averaged frames. Quantitatively, number of endpoints decreased by 51%, and SNR, mean capillary length, capillary density, and ICD increased by 44%, 91%, 11%, and 4.5% from single frame to 10-frame averaged, respectively. The 10-frame averaged images from the glaucomatous eyes revealed decreased density correlating to visual field defects and retinal nerve fiber layer thinning.OCTA image registration and averaging is a viable and accessible method to enhance the visualization of RPCs, with significant improvements in image quality and RPC quantitative parameters. With this technique, we will be able to non-invasively and reliably study RPC involvement in diseases such as glaucoma.

  19. Spatial coherence of electron beams from field emitters and its effect on the resolution of imaged objects

    Energy Technology Data Exchange (ETDEWEB)

    Latychevskaia, Tatiana, E-mail: tatiana@physik.uzh.ch

    2017-04-15

    Sub-nanometer and nanometer-sized tips provide high coherence electron sources. Conventionally, the effective source size is estimated from the extent of the experimental biprism interference pattern created on the detector by applying the van Cittert Zernike theorem. Previously reported experimental intensity distributions on the detector exhibit Gaussian distribution and our simulations show that this is an indication that such electron sources must be at least partially coherent. This, in turn means that strictly speaking the Van Cittert Zernike theorem cannot be applied, since it assumes an incoherent source. The approach of applying the van Cittert Zernike theorem is examined in more detail by performing simulations of interference patterns for the electron sources of different size and different coherence length, evaluating the effective source size from the extent of the simulated interference pattern and comparing the obtained result with the pre-defined value. The intensity distribution of the source is assumed to be Gaussian distributed, as it is observed in experiments. The visibility or the contrast in the simulated holograms is found to be always less than 1 which agrees well with previously reported experimental results and thus can be explained solely by the Gaussian intensity distribution of the source. The effective source size estimated from the extent of the interference pattern turns out to be of about 2–3 times larger than the pre-defined size, but it is approximately equal to the intrinsic resolution of the imaging system. A simple formula for estimating the intrinsic resolution, which could be useful when employing nano-tips in in-line Gabor holography or point-projection microscopy, is provided. - Highlights: • van Cittert Zernike theorem for nano- and sub-nano electron emitting tips is revised. • Simulations show that nano- and sub-nano electron emitting tips are at least partially coherent. • A simple formula for evaluating

  20. Effect of spatial coherence of LED sources on image resolution in holographic displays

    NARCIS (Netherlands)

    Pourreza Ghoushchi, Vahid; Aas, Mehdi; Ulusoy, Erdem; Ürey, Hakan

    2017-01-01

    Holographic Displays (HDs) provide 3D images with all natural depth cues via computer generated holograms (CGHs) implemented on spatial light modulators (SLMs). HDs are coherent light processing systems based on interference and diffraction, thus they generally use laser light. However, laser

  1. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, A. L.; Steenbergen, W.; van Leeuwen, T. G.; de Mul, F. F. M.

    2002-01-01

    A low coherence Mach-Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scattered photons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  2. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, Anna; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.

    2002-01-01

    A low coherence Mach–Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scatteredphotons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  3. Bullying Victimization Prevalence and Its Effects on Psychosomatic Complaints: Can Sense of Coherence Make a Difference?

    Science.gov (United States)

    García-Moya, Irene; Suominen, Sakari; Moreno, Carmen

    2014-01-01

    Background: The aim of this study was to examine the prevalence of bullying victimization and its impact on physical and psychological complaints in a representative sample of adolescents and to explore the role of sense of coherence (SOC) in victimization prevalence and consequences. Methods: A representative sample of Spanish adolescents (N =…

  4. A novel feedforward compensation canceling input filter-regulator interaction

    Science.gov (United States)

    Kelkar, S. S.; Lee, F. C.

    1983-01-01

    The interaction between the input and the control loop of switching regulators often results in deterimental effects, such as loop instability, degradation of transient response, and audiosusceptibility, etc. The concept of pole-zero cancelation is employed to mitigate some of these detrimental effects and is implemented using a novel feedforward loop, in addition to existing feedback loops of a buck regulator. Experimental results are presented which show excellent correlation with theory.

  5. Theory of coherent Stark nonlinear spectroscopy in a three-level system

    International Nuclear Information System (INIS)

    Loiko, Yurii; Serrat, Carles

    2007-01-01

    Coherent Stark nonlinear spectroscopy (CSNS) is a spectroscopic tool based on the cancellation of the phase sensitivity at frequency 5ω in the ultrafast four-wave mixing (FWM) of two-color pulses with frequencies ω and 3ω. We develop a theory for CSNS in three-level V-type systems, and reveal that the mechanism for the phase sensitivity at 5ω is the quantum interference between the two primary paths in the FWM of the ω and 3ω fields. We find that the cancellation phenomenon occurs when the probability amplitude of one of these two primary pathways becomes equal to zero due to the competition effect between the two allowed transitions in the V-type system. The analytical expressions that describe the phase-sensitivity phenomenon and the conditions for its cancellation have been derived on the basis of perturbation theory, and are confirmed by numerical integration of the density matrix and Maxwell equations. We argue that CSNS can be utilized, in particular, for the investigation of optically dense media

  6. 20 CFR 217.25 - Who may cancel an application.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Who may cancel an application. 217.25 Section... APPLICATION FOR ANNUITY OR LUMP SUM Cancellation of Application § 217.25 Who may cancel an application. An application may be cancelled by the claimant or a person described in § 217.17. If the claimant is deceased...

  7. 20 CFR 217.26 - How to cancel an application.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How to cancel an application. 217.26 Section... APPLICATION FOR ANNUITY OR LUMP SUM Cancellation of Application § 217.26 How to cancel an application. An application may be cancelled under the following conditions: (a) Before an annuity is awarded. The application...

  8. Active noise cancellation in hearing devices

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a hearing device system comprising at least one hearing aid circuitry and at least one active noise cancellation unit, the at least one hearing aid circuitry comprises at least one input transducer adapted to convert a first audio signal to an electric audio signal; a signal processor...... connected to the at least one input transducer and adapted to process said electric audio signal by at least partially correcting for a hearing loss of a user; an output transducer adapted to generate from at least said processed electric audio signal a sound pressure in an ear canal of the user, whereby...... the generated sound pressure is at least partially corrected for the hearing loss of the user; ; the at least one active noise cancellation unit being adapted to provide an active noise cancellation signal adapted to perform active noise cancellation of an acoustical signal entering the ear canal in addition...

  9. Optimal Reinsertion of Cancelled Train Lines

    DEFF Research Database (Denmark)

    Groth, Julie Jespersen; Clausen, Jens

    2006-01-01

    One recovery strategy in case of a major disruption in rail network is to cancel all trains on a specific line of the network. When the disturbance has ended, the cancelled line must be reinserted as soon as possible. In this article we present a mixed integer programming (MIP) model for calculat....... The model finds the optimal solution in an average of 0.5 CPU seconds in each test case....

  10. Dispersion cancellation in a triple Laue interferometer

    International Nuclear Information System (INIS)

    Lemmel, Hartmut

    2014-01-01

    The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

  11. FLUX CANCELLATION AND THE EVOLUTION OF THE ERUPTIVE FILAMENT OF 2011 JUNE 7

    Energy Technology Data Exchange (ETDEWEB)

    Yardley, S. L.; Green, L. M.; Williams, D. R.; Van Driel-Gesztelyi, L.; Valori, G.; Dacie, S., E-mail: stephanie.yardley.13@ucl.ac.uk [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom)

    2016-08-20

    We investigate whether flux cancellation is responsible for the formation of a very massive filament resulting in the spectacular eruption on 2011 June 7. We analyze and quantify the amount of flux cancellation that occurs in NOAA AR 11226 and its two neighboring active regions (ARs 11227 and 11233) using line-of-sight magnetograms from the Heliospheric Magnetic Imager. During a 3.6 day period building up to the eruption of the filament, 1.7 × 10{sup 21} Mx, 21% of AR 11226's maximum magnetic flux, was canceled along the polarity inversion line (PIL) where the filament formed. If the flux cancellation continued at the same rate up until the eruption then up to 2.8 × 10{sup 21} Mx (34% of the AR flux) may have been built into the magnetic configuration that contains the filament plasma. The large flux cancellation rate is due to an unusual motion of the positive-polarity sunspot, which splits, with the largest section moving rapidly toward the PIL. This motion compresses the negative polarity and leads to the formation of an orphan penumbra where one end of the filament is rooted. Dense plasma threads above the orphan penumbra build into the filament, extending its length, and presumably injecting material into it. We conclude that the exceptionally strong flux cancellation in AR 11226 played a significant role in the formation of its unusually massive filament. In addition, the presence and coherent evolution of bald patches in the vector magnetic field along the PIL suggest that the magnetic field configuration supporting the filament material is that of a flux rope.

  12. Coherent Destruction of Tunneling of Bosons with Effective Three-Body Interactions

    International Nuclear Information System (INIS)

    Niu Zhen-Xia; Yu Zi-Fa; Xue Ju-Kui

    2015-01-01

    The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerically. In our findings, when the system is with only repulsive two-body interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling (CDT). The quasi-energy of the system as the function of the periodically driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system. (paper)

  13. Patient experiences with interventions to reduce surgery cancellations

    DEFF Research Database (Denmark)

    Hovlid, Einar; von Plessen, Christian; Haug, Kjell

    2013-01-01

    The cancellation of planned surgery harms patients, increases waiting times and wastes scarce health resources. Previous studies have evaluated interventions to reduce cancellations from medical and management perspectives; these have focused on cost, length of stay, improved efficiency......, and reduced post-operative complications. In our case a hospital had experienced high cancellation rates and therefore redesigned their pathway for elective surgery to reduce cancelations. We studied how patients experienced interventions to reduce cancellations....

  14. Shielded coherent synchrotron radiation and its possible effect in the next linear collider

    International Nuclear Information System (INIS)

    Warnock, R.L.

    1991-05-01

    Shielded coherent synchrotron radiation is discussed in two cases: (1) a beam following a curved path in a plane midway between two parallel, perfectly conducting plates, and (2) a beam circulating in a toroidal chamber with resistive walls. Wake fields and the radiated energy are computed with parameters for the high-energy bunch compressor of the Next Linear Collider. 5 refs., 4 figs., 1 tab

  15. On The Use of A Phase Modulation Method for Decorrelation in Acoustic Feedback Cancellation

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    A major problem in using an adaptive filter in acoustic feedback cancellation systems is that the loudspeaker signal is correlated with the signals entering the microphones of the audio system, leading to biased filter estimates. One possible solution for reducing this problem is by means...... of decorrelation. In this work, we study a subband phase modulation method, which was originally proposed for decorrelation in multichannel acoustic echo cancellation systems. We determine if this method is effective for decorrelation in acoustic feedback cancellation systems by comparing it to a structurally...... similar frequency shifting decorrelation method. We show that the phase modulation method is suitable for decorrelation in a hearing aid acoustic feedback cancellation system, although the frequency shifting method is in general slightly more effective....

  16. Effect of Nonlinearity by the Amplitude Variation in coherent transmission in Laser Heterodyne Interferometric

    International Nuclear Information System (INIS)

    Chen, H F; Ding, X M; Zhong, Z; Xie, Z L; Yue, H

    2006-01-01

    To reduce the nonlinearity of nanometer measurement in laser heterodyne interferometric, the influence mechanics of the amplitude variation in coherent transmission upon nonlinearity must be confirmed. Based on the mechanics of nonlinearity, the models about how first-harmonic and second-harmonic nonlinearity caused by the amplitude variation in coherent transmission are proposed. The emulation result shows that different amplitude between measurement arm and reference arm increases the first-harmonic nonlinearity when laser beams nonorthogonality errors exist, but it doesn't change the relationship between nonlinearity and half wavelength. When the rotation angle error β of polarizing beam splitter (PBS) exists, amplitude variation only affects the first-harmonic nonlinearity. With a constant rotation angle of PBS β = 4 0 , when the amplitude factor of measurement arm reduces from 1 to 0.6, the nonlinearity increases from 0.25 nm to 3.81 nm, and the nonlinearity is simple superposition of first-harmonic and second-harmonic. Theoretic analysis and emulation show that the reduction of amplitude variation in coherent transmission can reduce influence on nonlinearity

  17. High Dynamic Range Nonlinear Measurement using Analog Cancellation

    Science.gov (United States)

    2012-10-01

    shield around sensitive areas. The target may also be sensitive to radiated coupling from the system and will benefit from a shield box or Faraday ... cage , if it is not already enclosed. On the shared measurement path and through the target, cross-channel coupling cannot be prevented, so low-PIM...testing is desired, traditional filtering is recommended, as the primary benefits of the analog canceller are effectively nullified. 2.4 Wideband

  18. Understanding Performance Decrements in a Letter-Canceling Task: Overcoming Habits or Inhibition of Reading.

    Science.gov (United States)

    Myers, Larry; Downie, Steven; Taylor, Grant; Marrington, Jessica; Tehan, Gerald; Ireland, Michael J

    2018-01-01

    The importance of self-regulation in human behavior is readily apparent and diverse theoretical accounts for explaining self-regulation failures have been proposed. Typically, these accounts are based on a sequential task methodology where an initial task is presented to deplete self-regulatory resources, and carryover effects are then examined on a second outcome task. In the aftermath of high profile replication failures using a popular letter-crossing task as a means of depleting self-regulatory resources and subsequent criticisms of that task, current research into self-control is currently at an impasse. This is largely due to the lack of empirical research that tests explicit assumptions regarding the initial task. One such untested assumption is that for resource depletion to occur, the initial task must first establish an habitual response and then this habitual response must be inhibited, with behavioral inhibition being the causal factor in inducing depletion. This study reports on four experiments exploring performance on a letter-canceling task, where the rules for target identification remained constant but the method of responding differed (Experiment 1) and the coherence of the text was manipulated (Experiments 1-4). Experiment 1 established that habit forming and behavioral inhibition did not produce any performance decrement when the targets were embedded in random letter strings. Experiments 2-4 established that target detection was sensitive to language characteristics and the coherence of the background text, suggesting that participants' automatic reading processes is a key driver of performance in the letter-e task.

  19. Active cancellation of probing in linear dipole phased array

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2015-01-01

    In this book, a modified improved LMS algorithm is employed for weight adaptation of dipole array for the generation of beam pattern in multiple signal environments. In phased arrays, the generation of adapted pattern according to the signal scenario requires an efficient adaptive algorithm. The antenna array is expected to maintain sufficient gain towards each of the desired source while at the same time suppress the probing sources. This cancels the signal transmission towards each of the hostile probing sources leading to active cancellation. In the book, the performance of dipole phased array is demonstrated in terms of fast convergence, output noise power and output signal-to-interference-and noise ratio. The mutual coupling effect and role of edge elements are taken into account. It is established that dipole array along with an efficient algorithm is able to maintain multilobe beamforming with accurate and deep nulls towards each probing source. This work has application to the active radar cross secti...

  20. Coherence and Sense of Coherence

    DEFF Research Database (Denmark)

    Dau, Susanne

    2014-01-01

    Constraints in the implementation of models of blended learning can be explained by several causes, but in this paper, it is illustrated that lack of sense of coherence is a major factor of these constraints along with the referential whole of the perceived learning environments. The question exa...

  1. Coherent tunneling of Bose-Einstein condensates: Exact solutions for Josephson effects and macroscopic quantum self-trapping

    International Nuclear Information System (INIS)

    Raghavan, S.; Fantoni, S.; Shenoy, S.R.; Smerzi, A.

    1997-07-01

    We consider coherent atomic tunneling between two weakly coupled Bose-Einstein condensates (BEC) at T = 0 in (possibly asymmetric) double-well trap. The condensate dynamics of the macroscopic amplitudes in the two wells is modeled by two Gross-Pitaevskii equations (GPE) coupled by a tunneling matrix element. The evolution of the inter-well fractional population imbalance (related to the condensate phase difference) is obtained in terms of elliptic functions, generalizing well-known Josephson effects such as the 'ac' effect, the 'plasma oscillations', and the resonant Shapiro effect, to the nonsiusoidal regimes. We also present exact solutions for a novel 'macroscopic quantum self-trapping' effect arising from nonlinear atomic self-interaction in the GPE. The coherent BEC tunneling signatures are obtained in terms of the oscillations periods and the Fourier spectrum of the imbalance oscillations, as a function of the initial values of GPE parameters. Experimental procedures are suggested to make contact with theoretical predictions. (author). 44 refs, 8 figs

  2. Finding of synergistic and cancel effects on the aroxyl radical-scavenging rate and suppression of prooxidant effect for coexistence of α-tocopherol with β-, γ-, and δ-tocopherols (or -tocotrienols).

    Science.gov (United States)

    Ouchi, Aya; Nagaoka, Shin-ichi; Suzuki, Tomomi; Izumisawa, Katsuhiro; Koike, Taisuke; Mukai, Kazuo

    2014-08-13

    Measurements of aroxyl radical (ArO•)-scavenging rate constants (k(s)(AOH)) of antioxidants (AOHs) [α-, β-, γ-, and δ-tocopherols (TocHs) and -tocotrienols (Toc-3Hs)] were performed in ethanol solution via stopped-flow spectrophotometry. k(s)(AOH) values of α-, β-, γ-, and δ-Toc-3Hs showed good agreement with those of the corresponding α-, β-, γ-, and δ- TocHs. k(s)(AOH) values were measured not only for each antioxidant but also for mixtures of two antioxidants: (i) α-TocH with β-, γ-, or δ-TocH and (ii) α-TocH with α-, β-, γ-, or δ-Toc-3H. A synergistic effect in which the k(s)(AOH) value increases by 12% for γ-TocH (or by 12% for γ-Toc-3H) was observed for solutions including α-TocH and γ-TocH (or γ-Toc-3H). On the other hand, a cancel effect in which the k(s)(AOH) value decreases (a) by 7% for β-TocH (or 11% for β-Toc-3H) and (b) by 24% for δ-TocH (or 25% for δ-Toc-3H) was observed for solutions including two kinds of antioxidants. However, only a synergistic effect may function in edible oils, because contents of β- and δ-TocHs (and β- and δ-Toc-3Hs) are much less than those of α- and γ-TocHs (and α- and γ-Toc-3Hs) in many edible oils. UV-vis absorption of α-Toc•, which was produced by reaction of α-TocH with ArO•, decreased remarkably for coexistence of α-TocH with β-, γ-, or δ-TocH (or β-, γ-, or δ-Toc-3H), indicating that the prooxidant effect of α-Toc• is suppressed by the coexistence of other TocHs and Toc-3Hs.

  3. Bench-marking beam-beam simulations using coherent quadrupole effects

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Chin, Y.H.

    1992-06-01

    Computer simulations are used extensively in the study of the beam-beam interaction. The proliferation of such codes raises the important question of their reliability, and motivates the development of a dependable set of bench-marks. We argue that rather than detailed quantitative comparisons, the ability of different codes to predict the same qualitative physics should be used as a criterion for such bench-marks. We use the striking phenomenon of coherent quadrupole oscillations as one such bench-mark, and demonstrate that our codes do indeed observe this behaviour. We also suggest some other tests that could be used as bench-marks

  4. Bench-marking beam-beam simulations using coherent quadrupole effects

    International Nuclear Information System (INIS)

    Krishnagopal, S.; Chin, Y.H.

    1992-01-01

    Computer simulations are used extensively in the study of the beam-beam interaction. The proliferation of such codes raises the important question of their reliability, and motivates the development of a dependable set of bench-marks. We argue that rather than detailed quantitative comparisons, the ability of different codes to predict the same qualitative physics should be used as a criterion for such bench-marks. We use the striking phenomenon of coherent quadrupole oscillations as one such bench-mark, and demonstrate that our codes do indeed observe this behavior. We also suggest some other tests that could be used as bench-marks

  5. Atomic-scale studies on the effect of boundary coherency on stability in twinned Cu

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Rongmei; Han, Ke, E-mail: han@magnet.fsu.edu; Su, Yi-Feng; Salters, Vincent J. [National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310 (United States)

    2014-01-06

    The stored energy and hardness of nanotwinned (NT) Cu are related to interaction between dislocations and (111)-twin boundaries (TBs) studied at atomic scales by high-angle annular dark-field scanning transmission electron microscope. Lack of mobile dislocations at coherent TBs (CTBs) provides as-deposited NT Cu a rare combination of stability and hardness. The introduction of numerous incoherent TBs (ITBs) reduces both the stability and hardness. While storing more energy in their ITBs than in the CTBs, deformed NT Cu also exhibits high dislocation density and TB mobility and therefore has increased the driving force for recovery, coarsening, and recrystallization.

  6. Atomic-scale studies on the effect of boundary coherency on stability in twinned Cu

    Science.gov (United States)

    Niu, Rongmei; Han, Ke; Su, Yi-Feng; Salters, Vincent J.

    2014-01-01

    The stored energy and hardness of nanotwinned (NT) Cu are related to interaction between dislocations and {111}-twin boundaries (TBs) studied at atomic scales by high-angle annular dark-field scanning transmission electron microscope. Lack of mobile dislocations at coherent TBs (CTBs) provides as-deposited NT Cu a rare combination of stability and hardness. The introduction of numerous incoherent TBs (ITBs) reduces both the stability and hardness. While storing more energy in their ITBs than in the CTBs, deformed NT Cu also exhibits high dislocation density and TB mobility and therefore has increased the driving force for recovery, coarsening, and recrystallization.

  7. Effect of trapping on transport coherence III: Dissipation in the stochastic Liouville equation approach

    Energy Technology Data Exchange (ETDEWEB)

    Barvik, I [International Centre for Theoretical Physics, Trieste (Italy); Polasek, M [Charles Univ., Prague (Czech Republic). Inst. of Physics; Herman, P [Pedagogical Univ., Hradec Kralove (Czech Republic)

    1995-08-01

    We used the formal stochastic Liouville equations within Haken-Strobl-Reineker parametrization for the description of the influence of the bath on the memory functions entering the GME for a dimer and a linear trimer with a trap (here modeled as a sink). The often used inclusion of the noncoherent regime in the MF by an exponentially damped prefactor (after Kenkre`s prescription) does not hold for finite systems. The analytical form of the MF is changed more pronouncely and the influence of the sink in the center of the trimer runs parallel with the influence of the bath in destroying the coherence. (author). 60 refs.

  8. Phase-conjugate optical coherence tomography

    International Nuclear Information System (INIS)

    Erkmen, Baris I.; Shapiro, Jeffrey H.

    2006-01-01

    Quantum optical coherence tomography (Q-OCT) offers a factor-of-2 improvement in axial resolution and the advantage of even-order dispersion cancellation when it is compared to conventional OCT (C-OCT). These features have been ascribed to the nonclassical nature of the biphoton state employed in the former, as opposed to the classical state used in the latter. Phase-conjugate OCT (PC-OCT) shows that nonclassical light is not necessary to reap Q-OCT's advantages. PC-OCT uses classical-state signal and reference beams, which have a phase-sensitive cross correlation, together with phase conjugation to achieve the axial resolution and even-order dispersion cancellation of Q-OCT with a signal-to-noise ratio that can be comparable to that of C-OCT

  9. IMPORTANT NOTICE: Cancellation of shuttle Circuit 3

    CERN Multimedia

    2013-01-01

    Circuit 3 of the CERN Shuttle Service (Point 5), which has served CMS since the start of LS1, will be cancelled with effect from Tuesday 16 April. This decision has been taken in consultation with CMS, as the circuit was seldom used.   In response to increasing demand for Circuit 1 - Meyrin and feedback from passengers, the two Circuit 3 journeys will be switched to Circuit 1 – Meyrin (see new timetable below): Mornings: Four journeys instead of three. Circuit 1 now starts at 8:10 (instead of 8:19 a.m.) and runs until 9:27 a.m. (instead of 9:16 a.m.). Lunchtimes: Five journeys in place between 12:10 p.m. and 1:47 p.m. Evenings: Circuit starts at 5:23 p.m. (instead of 5:03 p.m.) and ends at 6:20 p.m. at Building 33. Please note that the circuit will depart from Building 13 instead of Building 33.  

  10. Collinearity, convergence and cancelling infrared divergences

    International Nuclear Information System (INIS)

    Lavelle, Martin; McMullan, David

    2006-01-01

    The Lee-Nauenberg theorem is a fundamental quantum mechanical result which provides the standard theoretical response to the problem of collinear and infrared divergences. Its argument, that the divergences due to massless charged particles can be removed by summing over degenerate states, has been successfully applied to systems with final state degeneracies such as LEP processes. If there are massless particles in both the initial and final states, as will be the case at the LHC, the theorem requires the incorporation of disconnected diagrams which produce connected interference effects at the level of the cross-section. However, this aspect of the theory has never been fully tested in the calculation of a cross-section. We show through explicit examples that in such cases the theorem introduces a divergent series of diagrams and hence fails to cancel the infrared divergences. It is also demonstrated that the widespread practice of treating soft infrared divergences by the Bloch-Nordsieck method and handling collinear divergences by the Lee-Nauenberg method is not consistent in such cases

  11. Cancelable remote quantum fingerprint templates protection scheme

    International Nuclear Information System (INIS)

    Liao Qin; Guo Ying; Huang Duan

    2017-01-01

    With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit (qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantm mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users’ information for the fingerprint identification. (paper)

  12. Flux Cancellation Leading to CME Filament Eruptions

    Science.gov (United States)

    Popescu, Roxana M.; Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    Solar filaments are strands of relatively cool, dense plasma magnetically suspended in the lower density hotter solar corona. They trace magnetic polarity inversion lines (PILs) in the photosphere below, and are supported against gravity at heights of up to approx.100 Mm above the chromosphere by the magnetic field in and around them. This field erupts when it is rendered unstable, often by magnetic flux cancellation or emergence at or near the PIL. We have studied the evolution of photospheric magnetic flux leading to ten observed filament eruptions. Specifically, we look for gradual magnetic changes in the neighborhood of the PIL prior to and during eruption. We use Extreme Ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA), and magnetograms from the Helioseismic and Magnetic Imager (HMI), both on board the Solar Dynamics Observatory (SDO), to study filament eruptions and their photospheric magnetic fields. We examine whether flux cancellation or/and emergence leads to filament eruptions. We find that continuous flux cancellation was present at the PIL for many hours prior to each eruption. We present two CME-producing eruptions in detail and find the following: (a) the pre-eruption filament-holding core field is highly sheared and appears in the shape of a sigmoid above the PIL; (b) at the start of the eruption the opposite arms of the sigmoid reconnect in the middle above the site of (tether-cutting) flux cancellation at the PIL; (c) the filaments first show a slow-rise, followed by a fast-rise as they erupt. We conclude that these two filament eruptions result from flux cancellation in the middle of the sheared field, and thereafter evolve in agreement with the standard model for a CME/flare filament eruption from a closed bipolar magnetic field [flux cancellation (van Ballegooijen and Martens 1989 and Moore and Roumelrotis 1992) and runaway tether-cutting (Moore et. al 2001)].

  13. Probing Nuclear Spin Effects on Electronic Spin Coherence via EPR Measurements of Vanadium(IV) Complexes.

    Science.gov (United States)

    Graham, Michael J; Krzyaniak, Matthew D; Wasielewski, Michael R; Freedman, Danna E

    2017-07-17

    Quantum information processing (QIP) has the potential to transform numerous fields from cryptography, to finance, to the simulation of quantum systems. A promising implementation of QIP employs unpaired electronic spins as qubits, the fundamental units of information. Though molecular electronic spins offer many advantages, including chemical tunability and facile addressability, the development of design principles for the synthesis of complexes that exhibit long qubit superposition lifetimes (also known as coherence times, or T 2 ) remains a challenge. As nuclear spins in the local qubit environment are a primary cause of shortened superposition lifetimes, we recently conducted a study which employed a modular spin-free ligand scaffold to place a spin-laden propyl moiety at a series of fixed distances from an S = 1 / 2 vanadium(IV) ion in a series of vanadyl complexes. We found that, within a radius of 4.0(4)-6.6(6) Å from the metal center, nuclei did not contribute to decoherence. To assess the generality of this important design principle and test its efficacy in a different coordination geometry, we synthesized and investigated three vanadium tris(dithiolene) complexes with the same ligand set employed in our previous study: K 2 [V(C 5 H 6 S 4 ) 3 ] (1), K 2 [V(C 7 H 6 S 6 ) 3 ] (2), and K 2 [V(C 9 H 6 S 8 ) 3 ] (3). We specifically interrogated solutions of these complexes in DMF-d 7 /toluene-d 8 with pulsed electron paramagnetic resonance spectroscopy and electron nuclear double resonance spectroscopy and found that the distance dependence present in the previously synthesized vanadyl complexes holds true in this series. We further examined the coherence properties of the series in a different solvent, MeCN-d 3 /toluene-d 8 , and found that an additional property, the charge density of the complex, also affects decoherence across the series. These results highlight a previously unknown design principle for augmenting T 2 and open new pathways for the

  14. Macroscopic quantum interference in the conventional and coherent quantum 1/F effect with negative quantum entropy states

    International Nuclear Information System (INIS)

    Handel, P.H.

    1998-01-01

    The author's recent application of the new Quantum Information Theory Approach (QIT) to Infra Quantum Physics (IQP) explains for the first time the apparent lack of unitarity caused by the entropy increase in the Quantum 1/f Effect (Q1/fE). This allows for a better understanding of the quantum 1/f effect in this paper, showing no resultant entropy increase and therefore no violation of unitarity. This new interpretation involves the concept of von Neumann Quantum Entropy, including the new negative conditional entropy concept for quantum entangled states introduced by QIT. The Q1/fE was applied to many high-tech systems, in particular to ultra small electronic devices. The present paper explains how the additional entropy implied by the Q1/fE arises in spite of the entropy-conserving evolution of the system. On this basis, a general derivation of the conventional and coherent quantum 1/f effect is given. (author)

  15. Coherent Baryogenesis

    CERN Document Server

    Garbrecht, B; Schmidt, M G; Garbrecht, Bjorn; Prokopec, Tomislav; Schmidt, Michael G.

    2004-01-01

    We propose a new baryogenesis scenario based on coherent production and mixing of different fermionic species. The mechanism is operative during phase transitions, at which the fermions acquire masses via Yukawa couplings to scalar fields. Baryon production is efficient when the mass matrix is nonadiabatically varying, nonsymmetric and when it violates CP and B-L directly, or some other charges that are eventually converted to B-L. We first consider a toy model, which involves two mixing fermionic species, and then a hybrid inflationary scenario embedded in a supersymmetric Pati-Salam GUT. We show that, quite generically, a baryon excess in accordance with observation can result.

  16. Theory of the cancellation of 4-photon resonances by an off-resonance 3-photon cancellation

    DEFF Research Database (Denmark)

    Elk, M.; Lambropoulos, P.; Tang, X.

    1992-01-01

    We present a complete account of our recent work [Phys. Rev. A 44, 31 (1991)] in which we investigate the theory of cancellation by interference between the absorption of three fundamental laser photons and one third-harmonic photon. The theory is formulated in terms of the density matrix so...... as to take detunings, dephasing, and laser bandwidth into account. The result is a theory of cancellation for finite detuning that explains how four-photon resonances can be canceled by a three-photon mechanism if there is an atomic level at near-three-photon resonance. The treatment is extended to focused...

  17. Maintaining Web Cache Coherency

    Directory of Open Access Journals (Sweden)

    2000-01-01

    Full Text Available Document coherency is a challenging problem for Web caching. Once the documents are cached throughout the Internet, it is often difficult to keep them coherent with the origin document without generating a new traffic that could increase the traffic on the international backbone and overload the popular servers. Several solutions have been proposed to solve this problem, among them two categories have been widely discussed: the strong document coherency and the weak document coherency. The cost and the efficiency of the two categories are still a controversial issue, while in some studies the strong coherency is far too expensive to be used in the Web context, in other studies it could be maintained at a low cost. The accuracy of these analysis is depending very much on how the document updating process is approximated. In this study, we compare some of the coherence methods proposed for Web caching. Among other points, we study the side effects of these methods on the Internet traffic. The ultimate goal is to study the cache behavior under several conditions, which will cover some of the factors that play an important role in the Web cache performance evaluation and quantify their impact on the simulation accuracy. The results presented in this study show indeed some differences in the outcome of the simulation of a Web cache depending on the workload being used, and the probability distribution used to approximate updates on the cached documents. Each experiment shows two case studies that outline the impact of the considered parameter on the performance of the cache.

  18. Quantifying the effect of disruptions to temporal coherence on the intelligibility of compressed American Sign Language video

    Science.gov (United States)

    Ciaramello, Frank M.; Hemami, Sheila S.

    2009-02-01

    Communication of American Sign Language (ASL) over mobile phones would be very beneficial to the Deaf community. ASL video encoded to achieve the rates provided by current cellular networks must be heavily compressed and appropriate assessment techniques are required to analyze the intelligibility of the compressed video. As an extension to a purely spatial measure of intelligibility, this paper quantifies the effect of temporal compression artifacts on sign language intelligibility. These artifacts can be the result of motion-compensation errors that distract the observer or frame rate reductions. They reduce the the perception of smooth motion and disrupt the temporal coherence of the video. Motion-compensation errors that affect temporal coherence are identified by measuring the block-level correlation between co-located macroblocks in adjacent frames. The impact of frame rate reductions was quantified through experimental testing. A subjective study was performed in which fluent ASL participants rated the intelligibility of sequences encoded at a range of 5 different frame rates and with 3 different levels of distortion. The subjective data is used to parameterize an objective intelligibility measure which is highly correlated with subjective ratings at multiple frame rates.

  19. On Radar Resolution in Coherent Change Detection.

    Energy Technology Data Exchange (ETDEWEB)

    Bickel, Douglas L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    It is commonly observed that resolution plays a role in coherent change detection. Although this is the case, the relationship of the resolution in coherent change detection is not yet defined . In this document, we present an analytical method of evaluating this relationship using detection theory. Specifically we examine the effect of resolution on receiver operating characteristic curves for coherent change detection.

  20. Polarization effects in coherent and incoherent photon scattering: survey of measurements and theory relevant to radiation transport calculations

    International Nuclear Information System (INIS)

    Hubbell, J.H.

    1993-01-01

    This report reviews available information on polarization effects arising when photons in the X-ray and gamma-ray energy regime undergo coherent (Rayleigh) scattering and incoherent (Compton) scattering by atomic electrons. In addition to descriptions and discussions of these effects, including estimates of their magnitudes as they apply to radiation transport calculations, an annotated bibliography of 102 selected works covering the period 1905-1991 is provided, with particularly relevant works for the purpose of this report flagged with asterisks (*). A major resource for this report is a 1948 unpublished informal report by L.V. Spencer which has been quoted here almost in its entirety, since, of all the works cited in the annotated bibliography, it appears to be the only one which explicitly and directly addresses the purpose of this report. Hence this valuable material should be re-introduced into the available and current literature. (author). 119 refs., 7 figs

  1. Theory of coherent resonance energy transfer

    International Nuclear Information System (INIS)

    Jang, Seogjoo; Cheng, Y.-C.; Reichman, David R.; Eaves, Joel D.

    2008-01-01

    A theory of coherent resonance energy transfer is developed combining the polaron transformation and a time-local quantum master equation formulation, which is valid for arbitrary spectral densities including common modes. The theory contains inhomogeneous terms accounting for nonequilibrium initial preparation effects and elucidates how quantum coherence and nonequilibrium effects manifest themselves in the coherent energy transfer dynamics beyond the weak resonance coupling limit of the Foerster and Dexter (FD) theory. Numerical tests show that quantum coherence can cause significant changes in steady state donor/acceptor populations from those predicted by the FD theory and illustrate delicate cooperation of nonequilibrium and quantum coherence effects on the transient population dynamics.

  2. Distortion Cancellation via Polyphase Multipath Circuits

    NARCIS (Netherlands)

    Mensink, E.; Klumperink, Eric A.M.; Nauta, Bram

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits with the help of polyphase multipath circuits. Polyphase multipath circuits are circuits with two or more paths that exploit phase differences between the paths to cancel unwanted signals. It turns out

  3. 75 FR 28543 - Sunshine Act Meeting: Canceled

    Science.gov (United States)

    2010-05-21

    ... BROADCASTING BOARD OF GOVERNORS Sunshine Act Meeting: Canceled Date and Time: Tuesday, May 18, 2010, 11 a.m.-12:15 p.m. Place: Cohen Building, Room 3321, 330 Independence Ave., SW., Washington, DC 20237. Closed Meeting: The members of the Broadcasting Board of Governors (BBG) will meet in closed...

  4. Measurement of drag and its cancellation

    Energy Technology Data Exchange (ETDEWEB)

    DeBra, D B; Conklin, J W, E-mail: johnwc@stanford.edu [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305-4035 (United States)

    2011-05-07

    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  5. Measurement of drag and its cancellation

    International Nuclear Information System (INIS)

    DeBra, D B; Conklin, J W

    2011-01-01

    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  6. 78 FR 52513 - Sunshine Act Meeting; Cancellation

    Science.gov (United States)

    2013-08-23

    ..., August 21, 2013, page 51713. ANNOUNCED TIME AND DATE OF MEETING: Wednesday, August 21, 2013, 10 a.m.-11 a.m. MEETING CANCELED. For a recorded message containing the latest agenda information, call (301) 504... West Highway, Bethesda, MD 20814 (301) 504- 7923. Dated: August 21, 2013. Todd A. Stevenson, Secretary...

  7. Thermal Noise Canceling in LNAs : A Review

    NARCIS (Netherlands)

    Nauta, Bram; Klumperink, Eric A.M.; Bruccoleri, Frederico

    2004-01-01

    Most wide-band amplifiers suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the

  8. Amplifiers Exploiting Thermal Noise Canceling: A Review

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Bruccoleri, F.; Stroet, P.M.; Stroet, Peter; Nauta, Bram

    2004-01-01

    Wide-band LNAs suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and

  9. Multi moment cancellation of participant fluctuations

    OpenAIRE

    Begun, Viktor; Mackowiak-Pawlowska, Maja

    2017-01-01

    We summarize the new method for the correction of participant fluctuations in high energy nucleus-nucleus collisions. It allows to estimate a fluctuation baseline in comparison to a useful signal. In particular cases of a weak signal compared to baseline, it allows to cancel the baseline contribution from participants.

  10. Database Cancellation: The "Hows" and "Whys"

    Science.gov (United States)

    Shapiro, Steven

    2012-01-01

    Database cancellation is one of the most difficult tasks performed by a librarian. This may seem counter-intuitive but, psychologically, it is certainly true. When a librarian or a team of librarians has invested a great deal of time doing research, talking to potential users, and conducting trials before deciding to subscribe to a database, they…

  11. 40 CFR 152.99 - Petitions to cancel registration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Petitions to cancel registration. 152... Submitters' Rights § 152.99 Petitions to cancel registration. An original data submitter may petition the Agency to deny or cancel the registration of a product in accordance with this section if he has...

  12. Case review analysis of operating room decisions to cancel surgery.

    Science.gov (United States)

    Chang, Ju-Hsin; Chen, Ke-Wei; Chen, Kuen-Bao; Poon, Kin-Shing; Liu, Shih-Kai

    2014-07-23

    Cancellation of surgery close to scheduled time causes a waste of healthcare resources. The current study analyzes surgery cancellations occurring after the patient has been prepared for the operating room, in order to see whether improvements in the surgery planning process may reduce the number of cancellations. In a retrospective chart review of operating room surgery cancellations during the period from 2006 to 2011, cancellations were divided into the following categories: inadequate NPO; medical; surgical; system; airway; incomplete evaluation. The relative use of these reasons in relation to patient age and surgical department was then evaluated. Forty-one percent of cancellations were for other than medical reasons. Among these, 17.7% were due to incomplete evaluation, and 8.2% were due to family issues. Sixty seven percent of cancelled cases eventually received surgery. The relative use of individual reasons for cancellation varied with patient age and surgical department. The difference between cancellations before and after anesthesia was dependent on the causes of cancellation, but not age, sex, ASA status, or follow-up procedures required. Almost half of the cancellations were not due to medical reasons, and these cancellations could be reduced by better administrative and surgical planning and better communication with the patient and/or his family.

  13. Voluntary Cancellation of a Pesticide Product or Use

    Science.gov (United States)

    A registrant can cancel the registration of a pesticide product or cancel a use from the product’s label at any time as stated in Section 6(f) of FIFRA. Learn how to request a voluntary cancellation or use deletion.

  14. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    enhanced in quantum confined lower-dimensional systems, where exciton and biexciton effects dominate the spectra even at room temperature. The coherent dynamics of excitons are at modest densities well described by the optical Bloch equations and a number of the dynamical effects known from atomic......Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  15. Effect of low-energy coherent radiation with lambda=6328 A on the survival rate of Saccharomyces cerevisial of strain 14

    International Nuclear Information System (INIS)

    Abramova, N.V.

    1978-01-01

    The effect of the continuous monochromatic coherent laser radiation on the survival rate of Saccharomyces cerevisiae of strain 14 is studied. The effect of laser radiation is judged by the change in the survival rate of the yeast culture before and after the irradiation. The decrease of the number of the yeast cells in the initial moments of the irradiation was observed as a result of the laser irradiation. Then the rapid decrease of the number of cells with time changes into their constant number. It is established that the low-energy coherent radiation decreases the survival rate by 30-40%

  16. Effect of the Gouy phase on the coherent phase control of chemical reactions.

    Science.gov (United States)

    Gordon, Robert J; Barge, Vishal J

    2007-11-28

    We show how the spatial phase of a focused laser beam may be used as a tool for controlling the branching ratio of a chemical reaction. Guoy discovered [Acad. Sci., Paris, C. R. 110, 1250 (1890)] that when an electromagnetic wave passes through a focus its phase increases by pi. In a coherent control scheme involving the absorption of n photons of frequency omega(m) and m photons of frequency omega(n), the overall phase shift produced by the Gouy phase is (n-m)pi. At any given point in space, this phase shift is identical for all reaction products. Nevertheless, if the yields for different reaction channels have different intensity dependencies, the Gouy phase produces a net phase lag between the products that varies with the axial coordinate of the laser focus. We obtain here analytical and numerical values of this phase as the laser focus is scanned across the diameter of the molecular beam, taking into account the Rayleigh range and astigmatism of the laser beam and saturation of the transition. We also show that the modulation depth of the interference pattern may be increased by optimizing the relative intensities of the two fields.

  17. Effect of atomic-state coherence and spontaneous emission on three-level dynamics

    International Nuclear Information System (INIS)

    Cardimona, D.A.

    1990-01-01

    For a three-level atom in the ssV configuration (i.e., having two excited states each dipole-coupled to a common ground state), we have found a particular linear combination of bare-atom states in which Rabi oscillations and their associated collapses and revivals do not occur. Moving to a dressed-state picture, we discover that this particular linear combination state is just that dressed state which is decoupled from all the field modes. It is a dressed state for which the transition dipole moments with the other dressed states are zero. The existence of this decoupled dressed state depends on the tuning of the dressing laser field, which in turn depends on the bare-atom excited-state dipole moments and energy-level separation. When we include spontaneous emission, the population decays from the other dressed states into this decoupled state and remains coherently trapped there, producing a system that experiences no dynamical behavior. This is exact for δ-function photon statistics (i.e., if there is no intensity uncertainty). The trapping becomes less perfect as the photon statistics are allowed to have a greater bandwidth. Also, if the applied field is tuned incorrectly, the spontaneous realignment of the atomic state amplitudes does not result in a totally decoupled dressed state, and the dynamics proceed normally

  18. Effect of red blood cell aggregation and sedimentation on optical coherence tomography signals from blood samples

    International Nuclear Information System (INIS)

    Kirillin, M Yu; Priezzhev, A V; Tuchin, V V; Wang, R K; Myllylae, R

    2005-01-01

    In this work, Monte Carlo simulation is used to obtain model optical coherence tomography (OCT) signals from a horizontally orientated blood layer at different stages of red blood cell (RBC) aggregation and sedimentation processes. The parameters for aggregating and sedimenting blood cells were chosen based on the data available from the literature and our earlier experimental studies. We consider two different cases: a suspension of washed RBCs in physiological solution (where aggregation does not take place) and RBCs in blood plasma (which provides necessary conditions for aggregation). Good agreement of the simulation results with the available experimental data shows that the chosen optical parameters are reasonable. The dependence of the numbers of photons contributing to the OCT signal on the number of experienced scattering events was analysed for each simulated signal. It was shown that the maxima of these dependences correspond to the peaks in the OCT signals related to the interfaces between the layers of blood plasma and blood cells. Their positions can be calculated from the optical thicknesses of the layers, and the absorption and scattering coefficients of the media

  19. Coherence in quantum estimation

    Science.gov (United States)

    Giorda, Paolo; Allegra, Michele

    2018-01-01

    The geometry of quantum states provides a unifying framework for estimation processes based on quantum probes, and it establishes the ultimate bounds of the achievable precision. We show a relation between the statistical distance between infinitesimally close quantum states and the second order variation of the coherence of the optimal measurement basis with respect to the state of the probe. In quantum phase estimation protocols, this leads to propose coherence as the relevant resource that one has to engineer and control to optimize the estimation precision. Furthermore, the main object of the theory i.e. the symmetric logarithmic derivative, in many cases allows one to identify a proper factorization of the whole Hilbert space in two subsystems. The factorization allows one to discuss the role of coherence versus correlations in estimation protocols; to show how certain estimation processes can be completely or effectively described within a single-qubit subsystem; and to derive lower bounds for the scaling of the estimation precision with the number of probes used. We illustrate how the framework works for both noiseless and noisy estimation procedures, in particular those based on multi-qubit GHZ-states. Finally we succinctly analyze estimation protocols based on zero-temperature critical behavior. We identify the coherence that is at the heart of their efficiency, and we show how it exhibits the non-analyticities and scaling behavior proper of a large class of quantum phase transitions.

  20. Assessment of laser-induced acceleration effects in optical clearing of in vivo human skin by optical coherence tomography

    International Nuclear Information System (INIS)

    Zhan, Zhigang; Wei, Huajiang; Jin, Ying

    2015-01-01

    Laser irradiation is considered to be a promising innovative technology which has been developed in an attempt to increase transdermal drug delivery. In this study, a near-infrared CW diode laser (785 nm) was applied to increase permeability of glycerol solutions in human skin in vivo and improve the optical clearing efficacy. Results show that for both 15%v/v and 30%v/v glycerol, the permeability coefficient increased significantly if the detected area of the skin tissue was treated with laser irradiation before optical clearing agents (OCAs) were applied. This study based on optical coherence tomography imaging technique and optical clearing effect finds laser irradiation a new approach for enhancing the penetration of OCAs and accelerating the rate of transdermal drug delivery. (paper)

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

    International Nuclear Information System (INIS)

    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)

  2. Assessment of laser-induced acceleration effects in optical clearing of in vivo human skin by optical coherence tomography

    Science.gov (United States)

    Zhan, Zhigang; Wei, Huajiang; Jin, Ying

    2015-02-01

    Laser irradiation is considered to be a promising innovative technology which has been developed in an attempt to increase transdermal drug delivery. In this study, a near-infrared CW diode laser (785 nm) was applied to increase permeability of glycerol solutions in human skin in vivo and improve the optical clearing efficacy. Results show that for both 15%v/v and 30%v/v glycerol, the permeability coefficient increased significantly if the detected area of the skin tissue was treated with laser irradiation before optical clearing agents (OCAs) were applied. This study based on optical coherence tomography imaging technique and optical clearing effect finds laser irradiation a new approach for enhancing the penetration of OCAs and accelerating the rate of transdermal drug delivery.

  3. Optical polarization modulation by competing atomic coherence effects in a degenerate four-level Yb atomic system

    International Nuclear Information System (INIS)

    Park, Sung Jong; Park, Chang Yong; Yoon, Tai Hyun

    2005-01-01

    A scheme of optical polarization modulation of a linearly polarized infrared probe field is studied in a degenerate four-level Yb atomic system. We have observed an anomalous transmission spectra of two circular polarization components of the probe field exhibiting an enhanced two-photon absorption and a three-photon gain with comparable magnitude, leading to the lossless transmission and enhanced circular dichroism. We carried out a proof-of-principle experiment of fast optical polarization modulation in such a system by modulating the polarization state of the coupling field. The observed enhanced two-photon absorption and three-photon gain of the probe field are due to the result of competing atomic coherence effects

  4. Performance comparison of optical interference cancellation system architectures.

    Science.gov (United States)

    Lu, Maddie; Chang, Matt; Deng, Yanhua; Prucnal, Paul R

    2013-04-10

    The performance of three optics-based interference cancellation systems are compared and contrasted with each other, and with traditional electronic techniques for interference cancellation. The comparison is based on a set of common performance metrics that we have developed for this purpose. It is shown that thorough evaluation of our optical approaches takes into account the traditional notions of depth of cancellation and dynamic range, along with notions of link loss and uniformity of cancellation. Our evaluation shows that our use of optical components affords performance that surpasses traditional electronic approaches, and that the optimal choice for an optical interference canceller requires taking into account the performance metrics discussed in this paper.

  5. Study of ionizing radiation effects in human costal cartilage by thermogravimetry and optical coherence tomography

    International Nuclear Information System (INIS)

    Martinho Junior, Antonio Carlos

    2012-01-01

    Tissue Banks around the world have stored human cartilages obtained from post mortem donors for use in several kinds of reconstructive surgeries. To ensure that such tissues are not contaminated, they have been sterilized with ionizing radiation. However, high doses of gamma radiation may cause undesirable changes in the tissues. In this work, we evaluated the possibility of use Optical Coherence Tomography (OCT) and Thermogravimetric Analysis (TGA) to identify possible structural modifications caused by both preservation methods of cartilage and gamma irradiation doses. Cartilages were obtained from cadaveric donors and were frozen at -70 deg C or preserved in glycerol. Irradiation was performed by 60 Co source with doses of 15, 25 and 50 kGy. Our TGA results showed that glycerolized cartilages irradiated with different doses of radiation does not presented statistical differences when compared to the control group for the dehydration rate. However, the same was not observed for deep-frozen cartilages irradiated with 15 kGy. The results of OCT associated to total optical attenuation coefficient showed that doses of 15 kGy promote cross-link between collagen fibrils, corroborating the results obtained from TGA. Moreover, total optical attenuation coefficient values are proportional to stress at break of cartilages, what will be very useful in a near future to predict the quality of the allografts, without unnecessary loss of biological tissue, once OCT is a nondestructive technique. By PS-OCT images, we found that high doses of ionizing radiation does not promote sufficient impairments to promote complete loss of tissue birefringence. Thus, TGA and OCT are techniques that can be used for tissue banks to verify tissue quality before its transplant. (author)

  6. dq-Frame Cascaded Delayed Signal Cancellation-Based PLL

    DEFF Research Database (Denmark)

    Golestan, Saeed; Ramezani, Malek; Guerrero, Josep M.

    2015-01-01

    on their position in the PLL structure. Inspired from the concept of delayed signal cancellation (DSC), the idea of cascaded DSC (CDSC) has recently been introduced as an effective solution to improve the performance of the PLL under adverse grid conditions. However, the focus has been on the application of CDSC...... operator as the pre-filtering stage of PLL, and little work has been conducted on its application as the in-loop filtering stage of PLL. This paper provides a detailed analysis and design of dqCDSC-PLL (PLL with in-loop dq-frame CDSC operator). The study is started with an overview of this PLL...

  7. Time evolution of multiple quantum coherences in NMR

    International Nuclear Information System (INIS)

    Sanchez, Claudia M.; Pastawski, Horacio M.; Levstein, Patricia R.

    2007-01-01

    In multiple quantum NMR, individual spins become correlated with one another over time through their dipolar couplings. In this way, the usual Zeeman selection rule can be overcome and forbidden transitions can be excited. Experimentally, these multiple quantum coherences (MQC) are formed by the application of appropriate sequences of radio frequency pulses that force the spins to act collectively. 1 H spin coherences of even order up to 16 were excited in a polycrystalline sample of ferrocene (C 5 H 5 ) 2 Fe and up to 32 in adamantane (C 10 H 16 ) and their evolutions studied in different conditions: (a) under the natural dipolar Hamiltonian, H ZZ (free evolution) and with H ZZ canceled out by (b) time reversion or (c) with the MREV8 sequence. The results show that when canceling H ZZ the coherences decay with characteristic times (τ c ∼200 μs), which are more than one order of magnitude longer than those under free evolution (τ c ∼10 μs). In addition, it is observed that with both MREV8 and time reversion sequences, the higher the order of the coherence (larger number of correlated spins) the faster the speed of degradation, as it happens during the evolution with H ZZ . In both systems, it is observed that the sequence of time reversion of the dipolar Hamiltonian preserves coherences for longer times than MREV8

  8. High levels of comorbidity and disability cancel out the dementia effect in predictions of long-term mortality after discharge in the very old.

    Science.gov (United States)

    Zekry, Dina; Herrmann, François R; Graf, Christophe E; Giannelli, Sandra; Michel, Jean-Pierre; Gold, Gabriel; Krause, Karl-Heinz

    2011-01-01

    The relative weight of various etiologies of dementia as predictors of long-term mortality after other risk factors have been taken into account remains unclear. We investigated the 5-year mortality risk associated with dementia in elderly people after discharge from acute care, taking into account comorbid conditions and functionality. A prospective cohort study of 444 patients (mean age: 85 years; 74% female) discharged from the acute geriatric unit of Geneva University Hospitals. On admission, each subject underwent a standardized diagnostic evaluation: demographic variables, cognitive, comorbid medical conditions and functional assessment. Patients were followed yearly by the same team. Predictors of survival at 5 years were evaluated by Cox proportional hazards models. The univariate model showed that being older and male, and having vascular and severe dementia, comorbidity and functional disability, were predictive of shorter survival. However, in the full multivariate model adjusted for age and sex, the effect of dementia type or severity completely disappeared when all the variables were added. In multivariate analysis, the best predictor was higher comorbidity score, followed by functional status (R(2) = 23%). The identification of comorbidity and functional impairment effects as predictive factors for long-term mortality independent of cognitive status may increase the accuracy of long-term discharge planning. Copyright © 2011 S. Karger AG, Basel.

  9. Elective surgery cancelation on day of surgery: An endless dilemma

    Directory of Open Access Journals (Sweden)

    A Fayed

    2016-01-01

    Full Text Available Background: Cancelation of surgery is a constant agonizing dilemma for nearly all healthcare services that has been intensively investigated to find out its roots, consequences, and possible solutions. The rates of cancelation of surgery vary between centers and more so among surgical specialties with numerous reasons standing behind this phenomenon. Patients and Methods: In the current study, analysis of monthly cancelation rates from January 2009 to December 2012, and assessment of establishing new operating rooms (ORs using statistical process control charts was conducted. A detailed review of a total of 1813 cases canceled on the day of surgery from January to December 2012, to examine the various reasons of cancelation among surgical specialties. Results: The average cancelation rate was 11.1%, which dropped to 9.0% after launching of new theaters. Four reasons explained about 80% of cancelations; Patients "no show" was the leading cause of cancelation (27%. One-fourth of cancelations (24.3% were due to the need for further optimization, and the third most prominent cause of cancelation was a lack of OR time (19.5%. Unavailability of staff/equipment/implants accounted for only 0.7% of cancelations. The "no show" was the most common cause of cancelation among all surgical specialties ranging from 21% for plastic surgery to 32% in ophthalmic surgeries. Conclusion: It was confirmed that there is a unique profile of cancelation of surgery problem for every institute, an extension of infrastructure may not be the only solution. Control charts helped to enhance the general picture and are functional in monitoring and evaluating changes in the cancelation of surgery.

  10. Cloaking through cancellation of diffusive wave scattering

    KAUST Repository

    Farhat, Mohamed

    2016-08-10

    A new cloaking mechanism, which makes enclosed objects invisible to diffusive photon density waves, is proposed. First, diffusive scattering from a basic core-shell geometry, which represents the cloaked structure, is studied. The conditions of scattering cancellation in a quasi-static scattering regime are derived. These allow for tailoring the diffusivity constant of the shell enclosing the object so that the fields scattered from the shell and the object cancel each other. This means that the photon flow outside the cloak behaves as if the cloaked object were not present. Diffusive light invisibility may have potential applications in hiding hot spots in infrared thermography or tissue imaging. © 2016 The Author(s) Published by the Royal Society. All rights reserved.

  11. Active microphonic noise cancellation in radiation detectors

    International Nuclear Information System (INIS)

    Zimmermann, Sergio

    2013-01-01

    A new adaptive filtering technique to reduce microphonic noise in radiation detectors is presented. The technique is based on system identification that actively cancels the microphonic noise. A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly, and the digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. The noise then can be subtracted from the actual detector measurement. In this paper the technique is presented and simulations are used to support this approach. -- Highlights: •A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly. •Digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. •The noise is then subtracted from the actual detector measurement. •We use simulations to demonstrate the performance of this approach. •After cancellation, we recover most of the original energy resolution

  12. Coherence in electron energy loss spectrometry

    International Nuclear Information System (INIS)

    Schattschneider, P.; Werner, W.S.M.

    2005-01-01

    Coherence effects in electron energy loss spectrometry (EELS) and in energy filtering are largely neglected although they occur frequently due to Bragg scattering in crystals. We discuss how coherence in the inelastically scattered wave field can be described by the mixed dynamic form factor (MDFF), and how it relates to the density matrix of the scattered electrons. Among the many aspects of 'inelastic coherence' are filtered high-resolution images, dipole-forbidden transitions, coherence in plasma excitations, errors in chemical microanalysis, coherent double plasmons, and circular dichroism

  13. Amplifiers Exploiting Thermal Noise Canceling: A Review

    OpenAIRE

    Klumperink, Eric A.M.; Bruccoleri, Federico; Stroet, Peter; Nauta, Bram

    2004-01-01

    Wide-band LNAs suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and its key properties. Although the technique has been applied to wideband CMOS LNAs, it can just as well be implemented exploiting transconductance elements realized with oth...

  14. Using Comics to Communicate Legal Contract Cancellation

    Directory of Open Access Journals (Sweden)

    Marietjie Botes

    2017-10-01

    Full Text Available This article investigates how comics can be used to adequately communicate the correct process of contract cancellation and whether comics can enhance understanding of the legal process. A survey of pre-owned vehicle buyers of various levels of education in Pretoria, South Africa found that when comics are used to communicate contract cancellation, a significant increase in the comprehension of the legal cancellation process occurs. The results may influence how contracting parties may choose to communicate complex legal issues in future, specifically to consumers with little formal education or when parties are confronted with severe language barriers, which is highly relevant in a country such as South Africa with eleven official languages and generally low levels of education. The article argues that representatives tasked with explaining contractual content to contracting parties should consider making use of comics to aid them in their communication process to ensure proper understanding and execution of terms and conditions, which in turn may lead to fewer disputes and avoid expensive litigation.

  15. Susceptibility cancellation of a microcoil wound with a paramagnetic-liquid-filled copper capillary

    Science.gov (United States)

    Takeda, Kazuyuki; Takasaki, Tomoya; Takegoshi, K.

    2015-09-01

    Even though microcoils improve the sensitivity of NMR measurement of tiny samples, magnetic-field inhomogeneity due to the bulk susceptibility effect of the coil material can cause serious resonance-line broadening. Here, we propose to fabricate the microcoil using a thin, hollow copper capillary instead of a wire and fill paramagnetic liquid inside the capillary, so as to cancel the diamagnetic contribution of the copper. Susceptibility cancellation is demonstrated using aqueous solution of NiSO4. In addition, the paramagnetic liquid serves as coolant when it is circulated through the copper capillary, effectively transferring the heat generated by radiofrequency pulses.

  16. Impact of coherent synchrotron radiation on beam qualities in a Chicane

    International Nuclear Information System (INIS)

    Xiang Dao; Huang Wenhui; He Xiaozhong

    2004-01-01

    When the bunch goes through a Chicane, the energy will be redistributed within the bunch due to CSR (coherent synchrotron radiation), which would cause nonlinearity. Present theory states that this nonlinearity would add a huge amount to emittance growth. Based on simulation results, this paper would point out that the theory is only valid under an ideal condition that the bunch initially has no nonlinearity and under some given parameters there could be a cancellation between the nonlinearity caused by CSR and the initial nonlinearity. So under these circumstances authors can expect CSR to improve the beam quality. This paper provides a brief information about CSR and a full estimation of effects of CSR on beam qualities

  17. Octopus-inspired drag cancelation by added mass pumping

    Science.gov (United States)

    Weymouth, Gabriel; Giorgio-Serchi, Francesco

    2016-11-01

    Recent work has shown that when an immersed body suddenly changes its size, such as a deflating octopus during rapid escape jetting, the body experiences large forces due to the variation of added-mass energy. We extend this line of research by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. This system isolates the ability of the added-mass thrust to cancel the bluff body resistance (having no jet flow to confuse the analysis) and moves closer to studying how these effects would work in a sustained propulsion case by studying periodic shape-change instead of a "one-shot" escape maneuver. With a combination of analytical, numerical, and experimental results, we show that the recovery of added-mass kinetic energy can be used to completely cancel the drag of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius. Moreover, these results are fairly independent of the details of the shape-change kinematics as long as the Stokes number and shape-change number are large. In addition, the effective pumping frequency range based on parametric oscillator analysis is shown to predict large amplitude response region observed in the numerics and experiments.

  18. Cancellation of RF Coupler-Induced Emittance Due to Astigmatism

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, David H.; /SLAC

    2016-12-11

    It is well-known that the electron beam quality required for applications such as FEL’s and ultra-fast electron diffraction can be degraded by the asymmetric fields introduced by the RF couplers of superconducting linacs. This effect is especially troublesome in the injector where the low energy beam from the gun is captured into the first high gradient accelerator section. Unfortunately modifying the established cavity design is expensive and time consuming, especially considering that only one or two sections are needed for an injector. Instead, it is important to analyze the coupler fields to understand their characteristics and help find less costly solutions for their cancellation and mitigation. This paper finds the RF coupler-induced emittance for short bunches is mostly due to the transverse spatial sloping or tilt of the field, rather than the field’s time-dependence. It is shown that the distorting effects of the coupler can be canceled with a static (DC) quadrupole lens rotated about the z-axis.

  19. Flux canceling in three-dimensional radiative magnetohydrodynamic simulations

    Science.gov (United States)

    Thaler, Irina; Spruit, H. C.

    2017-05-01

    We aim to study the processes involved in the disappearance of magnetic flux between regions of opposite polarity on the solar surface using realistic three-dimensional (3D) magnetohydrodynamic (MHD) simulations. "Retraction" below the surface driven by magnetic forces is found to be a very effective mechanism of flux canceling of opposite polarities. The speed at which flux disappears increases strongly with initial mean flux density. In agreement with existing inferences from observations we suggest that this is a key process of flux disappearance within active complexes. Intrinsic kG strength concentrations connect the surface to deeper layers by magnetic forces, and therefore the influence of deeper layers on the flux canceling process is studied. We do this by comparing simulations extending to different depths. For average flux densities of 50 G, and on length scales on the order of 3 Mm in the horizontal and 10 Mm in depth, deeper layers appear to have only a mild influence on the effective rate of diffusion.

  20. Destruction of coherence in nondemolition monitoring: quantum 'watchdog effect' in gravity wave detectors

    International Nuclear Information System (INIS)

    Zurek, W.H.

    1984-01-01

    The author shows that nondemolition monitoring of a Weber bar may prevent changes of the number of phonons, and thus influence the sensitivity of quantum-counting gravity wave detectors. This effect is similar to the Watchdog Effect which is predicted to delay decays of the monitored, unstable quantum system. Relations between watchdog effect and Environment-Induced Superselection Rules as well as its connections to the fundamental questions of the quantum theory of measurement are briefly considered. (Auth.)

  1. Analysis, Design, and Evaluation of Acoustic Feedback Cancellation Systems for Hearing Aids

    DEFF Research Database (Denmark)

    Guo, Meng

    2013-01-01

    Acoustic feedback problems occur when the output loudspeaker signal of an audio system is partly returned to the input microphone via an acoustic coupling through the air. This problem often causes significant performance degradations in applications such as public address systems and hearing aids....... In the worst case, the audio system becomes unstable and howling occurs. In this work, first we analyze a general multiple microphone audio processing system, where a cancellation system using adaptive filters is used to cancel the effect of acoustic feedback. We introduce and derive an accurate approximation...... in acoustic feedback cancellation for hearing aids. It utilizes a probe noise signal which is generated with a specific characteristic so that it can facilitate an unbiased adaptive filter estimation with fast tracking of feedback path variations/changes despite its low signal level. We show in a hearing aid...

  2. Mutual associations among microstructural, physical and mechanical properties of human cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Danielsen, CC

    2002-01-01

    structure and mechanical properties. In this study, 160 cancellous bone specimens were produced from 40 normal human tibiae aged from 16 to 85 years at post-mortem. The specimens underwent micro-CT and the microstructural properties were calculated using unbiased three-dimensional methods. The specimens...... were tested to determine the mechanical properties and the physical/compositional properties were evaluated. The type of structure together with anisotropy correlated well with Young's modulus of human tibial cancellous bone. The plate-like structure reflected high mechanical stress and the rod......-like structure low mechanical stress. There was a strong correlation between the type of trabecular structure and the bone-volume fraction. The most effective microstructural properties for predicting the mechanical properties of cancellous bone seem to differ with age....

  3. Performance of Turbo Interference Cancellation Receivers in Space-Time Block Coded DS-CDMA Systems

    Directory of Open Access Journals (Sweden)

    Emmanuel Oluremi Bejide

    2008-07-01

    Full Text Available We investigate the performance of turbo interference cancellation receivers in the space time block coded (STBC direct-sequence code division multiple access (DS-CDMA system. Depending on the concatenation scheme used, we divide these receivers into the partitioned approach (PA and the iterative approach (IA receivers. The performance of both the PA and IA receivers is evaluated in Rayleigh fading channels for the uplink scenario. Numerical results show that the MMSE front-end turbo space-time iterative approach receiver (IA effectively combats the mixture of MAI and intersymbol interference (ISI. To further investigate the possible achievable data rates in the turbo interference cancellation receivers, we introduce the puncturing of the turbo code through the use of rate compatible punctured turbo codes (RCPTCs. Simulation results suggest that combining interference cancellation, turbo decoding, STBC, and RCPTC can significantly improve the achievable data rates for a synchronous DS-CDMA system for the uplink in Rayleigh flat fading channels.

  4. Analysis of Acoustic Feedback/Echo Cancellation in Multiple-Microphone and Single-Loudspeaker Systems Using a Power Transfer Function Method

    DEFF Research Database (Denmark)

    Guo, Meng; Bo Elmedyb, Thomas; Jensen, Søren Holdt

    2011-01-01

    In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate...

  5. Effects of background noise on inter-trial phase coherence and auditory N1-P2 responses to speech stimuli.

    Science.gov (United States)

    Koerner, Tess K; Zhang, Yang

    2015-10-01

    This study investigated the effects of a speech-babble background noise on inter-trial phase coherence (ITPC, also referred to as phase locking value (PLV)) and auditory event-related responses (AERP) to speech sounds. Specifically, we analyzed EEG data from 11 normal hearing subjects to examine whether ITPC can predict noise-induced variations in the obligatory N1-P2 complex response. N1-P2 amplitude and latency data were obtained for the /bu/syllable in quiet and noise listening conditions. ITPC data in delta, theta, and alpha frequency bands were calculated for the N1-P2 responses in the two passive listening conditions. Consistent with previous studies, background noise produced significant amplitude reduction and latency increase in N1 and P2, which were accompanied by significant ITPC decreases in all the three frequency bands. Correlation analyses further revealed that variations in ITPC were able to predict the amplitude and latency variations in N1-P2. The results suggest that trial-by-trial analysis of cortical neural synchrony is a valuable tool in understanding the modulatory effects of background noise on AERP measures. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Cancellation of a wind farm project in an area covered by the Mountain law

    International Nuclear Information System (INIS)

    Roux, Gilles

    2017-01-01

    In April 2017 the court of appeal of Marseille (South-East France) had to deal with the cancellation request of a prefectorial order authorizing the building of 9 wind turbines. The court, after appraisal of the quality of the area in concern and of the landscape impacts this project should generate, considered that the project would effectively strongly impact the natural areas and thus has ordered the cancellation of the prefectorial order. This paper presents the explanatory statement and the conclusions of the judgement

  7. Improved delayed signal cancellation-based SRF-PLL for unbalanced grid

    DEFF Research Database (Denmark)

    Messo, Tuomas; Sihvo, Jussi; Yang, Dongsheng

    2017-01-01

    Problems with power quality in the grid have gained a lot of attention recently due to rapid increase in the amount of grid-connected power converters. The converter should produce sinusoidal currents also during abnormal conditions, such as unbalanced grid voltages. Several methods, like...... the delayed signal cancellation-based method (DSC), have been proposed to alleviate the detrimental effect of unbalance. This paper proposes an improvement to a delayed signal cancellation based synchronization algorithm for unbalanced grids. The proposed PLL structure employs only half of the delay required...

  8. Notch Filter Analysis and Its Application in Passive Coherent Location Radar (in English

    Directory of Open Access Journals (Sweden)

    Li Ji-chuan

    2015-01-01

    Full Text Available The Normalized Least-Mean-Squares (NLMS algorithm is widely used to cancel the direct and multiple path interferences in Passive Coherent Location (PCL radar systems. This study proposes that the interference cancelation using the NLMS algorithm and the calculation of the radar Cross Ambiguity Function (CAF can be modeled as a notch filter, with the notch located at zero Doppler frequency in the surface of the radar CAF. The analysis shows that the notch’s width and depth are closely related to the step size of the NLMS algorithm. Subsequently, the effect of the notch in PCL radar target detection is analyzed. The results suggest that the detection performance of the PCL radar deteriorates because of the wide notch. Furthermore, the Nonuniform NLMS (NNLMS algorithm is proposed for removing the clutter with the Doppler frequency by using notch filtering. A step-size matrix is adopted to mitigate the low Doppler frequency clutter and lower the floor of the radar CAF. With the step-size matrix, can be obtained notches of different depths and widths in different range units of the CAF, which can filter the low Doppler frequency clutter. In addition, the convergence rate of the NNLMS algorithm is better than that of the traditional NLMS algorithm. The validity of the NNLMS algorithm is verified by experimental results.

  9. Coherent radiation from pulsars

    International Nuclear Information System (INIS)

    Cox, J.L. Jr.

    1979-01-01

    Interaction between a relativistic electrom stream and a plasma under conditions believed to exist in pulsar magnetospheres is shown to result in the simultaneous emission of coherent curvature radiation at radio wavelengths and incoherent curvature radiation at X-ray wavelengths from the same spatial volume. It is found that such a stream can propagate through a plasma parallel to a very strong magnetic field only if its length is less than a critical length L/sub asterisk/ic. Charge induced in the plasma by the stream co-moves with the stream and has the same limitation in longitudinal extent. The resultant charge bunching is sufficient to cause the relatively low energy plasma particles to radiate at radio wavelengths coherently while the relatively high energy stream particles radiate at X-ray wavelengths incoherently as the stream-plasma system moves along curved magnetic field lines. The effective number of coherently radiating particles per bunch is estimated to be approx.10 14 --10 15 for a tupical pulsar

  10. Effects of diffraction and target finite size on coherent transition radiation spectra in bunch length measurements

    Energy Technology Data Exchange (ETDEWEB)

    Castellano, M.; Cianchi, A.; Verzilov, V.A. [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati; Orlandi, G. [Istituto Nazionale di Fisica Nucleare, Rome (Italy)]|[Rome Univ., Tor Vergata, Rome (Italy)

    1999-07-01

    Effects of diffraction and the size of the target on TR in the context of CTR-based bunch length measurements are studied on the basis of Kirchhoff diffraction theory. Spectra of TR from the finite-size target for several schemes of measurements are calculated in the far-infrared region showing strong distortion at low frequencies. Influence of the effect on the accuracy of bunch length measurements is estimated.

  11. Intelligent coil drum with electromagnetic force cancellation for MRI equipment

    International Nuclear Information System (INIS)

    Qiu, Jinhao; Tani, Junji; Ohtomo, Kikuo

    1995-01-01

    High-level noise induced in MRI equipment has been a main obstacle for their wide application in medical diagnosis. The noise is caused by the vibration of the cylindrical shell used to support the gradient magnetic field coils in MRI. In this study, a reduced-size model of the coil drum is constructed using polymer films and piezoelectric films. The piezoelectric films are divided into several patches and two patches of them are used as integrated bending actuators in the control of the shell vibration so that no external actuators are needed. The disturbance cancellation method is used since the shell is excited by predetermined forces. The relationships between the size, position and output magnitude of the actuators and control effect are also discussed. Experiment and simulation were carried out for the cases where the shell was excited at resonance frequencies of three main modes. The results show that the disturbance cancellation method in combination with the piezoelectric film actuators can successfully suppress the forced vibration of the shell and that the minimum amplitude of controlled vibration varies with the resonance mode. (author)

  12. Optical coherence tomography assessment of the mechanistic effects of rotational and orbital atherectomy in severely calcified coronary lesions.

    Science.gov (United States)

    Kini, Annapoorna S; Vengrenyuk, Yuliya; Pena, Jacobo; Motoyama, Sadako; Feig, Jonathan E; Meelu, Omar A; Rajamanickam, Anitha; Bhat, Arjun M; Panwar, Sadik; Baber, Usman; Sharma, Samin K

    2015-11-15

    This study sought to assess the mechanistic effect of rotational atherectomy (RA) and orbital atherectomy (OA) on heavily calcified coronary lesions and subsequent stent placement using optical coherence tomography (OCT). RA and OA are two main approaches to ablate coronary calcium. While small case reports have described the mechanistic effect of RA in calcified coronary lesions, there has been no imaging study to assess the effect of OA on coronary artery architecture and/or compare the effects of two atherectomy devices. This study analyzed 20 consecutive patients with OCT imaging performed after atherectomy and after stent implantation, RA (n = 10) and OA (n = 10). Postatherectomy OCT analysis identified tissue modification with deep dissections in around a third of lesions after RA and OA; however, post OA dissections ("lacunae") were significantly deeper (1.14 vs. 0.82 mm, P = 0.048). Post OA/RA lesions with dissections had significantly higher percentage of lipid rich plaques and smaller calcification arcs as compared to plaques without dissections. Stents after OA were associated with a significantly lower percent of stent strut malapposition than post RA stents (4.36 vs. 8.02%, P = 0.038). Although the incidence of dissections was comparable between RA and OA cases, OA resulted in deeper tissue modifications (lacunae) as shown by OCT imaging. The finding might provide an explanation for a better stent apposition after OA as compared to RA. Their impact on long-term outcome needs to be determined. © 2015 Wiley Periodicals, Inc.

  13. Effect of Hydroxychloroquine on the Retinal Layers: A Quantitative Evaluation with Spectral-Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hasim Uslu

    2016-01-01

    Full Text Available Purpose. To evaluate the effect of hydroxychloroquine on retinal pigment epithelium- (RPE- Bruch’s membrane complex, photoreceptor outer segment, and macular ganglion cell-inner plexiform layer (GCIPL thicknesses using spectral-domain optical coherence tomography (SD-OCT. Methods. In this prospective case-control study, 51 eyes of 51 hydroxychloroquine patients and 30 eyes of 30 healthy subjects were included. High-quality images were obtained using a Cirrus HD-OCT with 5-line raster mode; the photoreceptor inner segment (IS and outer segment (OS, sum of the segments (IS + OS, and RPE-Bruch’s membrane complex were analyzed. Results. The thicknesses of the IS + OS and OS layers were significantly lower in the hydroxychloroquine subjects compared to the control subjects (P<0.05. RPE-Bruch’s membrane complex thicknesses were significantly higher in the hydroxychloroquine subjects than for those of the control subjects (P<0.05. The minimum and temporal-inferior macular GCIPL thicknesses were significantly different between the patients with hydroxychloroquine use and the control subjects (P=0.04 and P=0.03, resp.. Conclusions. The foveal photoreceptor OS thinning, loss of GCIPL, and RPE-Bruch’s membrane thickening were detected in patients with hydroxychloroquine therapy. This quantitative approach using SD-OCT images may have important implications to use as an early indicator of retinal toxicity without any visible signs of hydroxychloroquine retinopathy.

  14. Coherent oscillations between two weakly coupled Bose-Einstein condensates: Josephson effects, π oscillations, and macroscopic quantum self-trapping

    International Nuclear Information System (INIS)

    Raghavan, S.; Smerzi, A.; Fantoni, S.; Shenoy, S.R.

    2001-03-01

    We discuss the coherent atomic oscillations between two weakly coupled Bose-Einstein condensates. The weak link is provided by a laser barrier in a (possibly asymmetric) double-well trap or by Raman coupling between two condensates in different hyperfine levels. The boson Josephson junction (BJJ) dynamics is described by the two-mode nonlinear Gross-Pitaevskii equation that is solved analytically in terms of elliptic functions. The BJJ, being a neutral, isolated system, allows the investigations of dynamical regimes for the phase difference across the junction and for the population imbalance that are not accessible with superconductor Josephson junctions (SJJ's). These include oscillations with either or both of the following properties: (i) the time-averaged value of the phase is equal to π (π-phase oscillations); (ii) the average population imbalance is nonzero, in states with macroscopic quantum self-trapping. The (nonsinusoidal) generalization of the SJJ ac and plasma oscillations and the Shapiro resonance can also be observed. We predict the collapse of experimental data (corresponding to different trap geometries and the total number of condensate atoms) onto a single universal curve for the inverse period of oscillations. Analogies with Josephson oscillations between two weakly coupled reservoirs of 3 He-B and the internal Josephson effect in 3 He-A are also discussed. (author)

  15. Performance evaluation of coherent WDM PS-QPSK (HEXA) accounting for non-linear fiber propagation effects.

    Science.gov (United States)

    Poggiolini, P; Bosco, G; Carena, A; Curri, V; Forghieri, F

    2010-05-24

    Coherent-detection (CoD) permits to fully exploit the four-dimensional (4D) signal space consisting of the in-phase and quadrature components of the two fiber polarizations. A well-known and successful format exploiting such 4D space is Polarization-multiplexed QPSK (PM-QPSK). Recently, new signal constellations specifically designed and optimized in 4D space have been proposed, among which polarization-switched QPSK (PS-QPSK), consisting of a 8-point constellation at the vertices of a 4D polychoron called hexadecachoron. We call it HEXA because of its geometrical features and to avoid acronym mix-up with PM-QPSK, as well as with other similar acronyms. In this paper we investigate the performance of HEXA in direct comparison with PM-QPSK, addressing non-linear propagation over realistic links made up of 20 spans of either standard single mode fiber (SSMF) or non-zero dispersion-shifted fiber (NZDSF). We show that HEXA not only confirms its theoretical sensitivity advantage over PM-QPSK in back-to-back, but also shows a greater resilience to non-linear effects, allowing for substantially increased span loss margins. As a consequence, HEXA appears as an interesting option for dual-format transceivers capable to switch on-the-fly between PM-QPSK and HEXA when channel propagation degrades. It also appears as a possible direct competitor of PM-QPSK, especially over NZDSF fiber and uncompensated links.

  16. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging

    Science.gov (United States)

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  17. Effects of virtual speaker density and room reverberation on spatiotemporal thresholds of audio-visual motion coherence.

    Directory of Open Access Journals (Sweden)

    Narayan Sankaran

    Full Text Available The present study examined the effects of spatial sound-source density and reverberation on the spatiotemporal window for audio-visual motion coherence. Three different acoustic stimuli were generated in Virtual Auditory Space: two acoustically "dry" stimuli via the measurement of anechoic head-related impulse responses recorded at either 1° or 5° spatial intervals (Experiment 1, and a reverberant stimulus rendered from binaural room impulse responses recorded at 5° intervals in situ in order to capture reverberant acoustics in addition to head-related cues (Experiment 2. A moving visual stimulus with invariant localization cues was generated by sequentially activating LED's along the same radial path as the virtual auditory motion. Stimuli were presented at 25°/s, 50°/s and 100°/s with a random spatial offset between audition and vision. In a 2AFC task, subjects made a judgment of the leading modality (auditory or visual. No significant differences were observed in the spatial threshold based on the point of subjective equivalence (PSE or the slope of psychometric functions (β across all three acoustic conditions. Additionally, both the PSE and β did not significantly differ across velocity, suggesting a fixed spatial window of audio-visual separation. Findings suggest that there was no loss in spatial information accompanying the reduction in spatial cues and reverberation levels tested, and establish a perceptual measure for assessing the veracity of motion generated from discrete locations and in echoic environments.

  18. Effects of moderate pump and Stokes chirp on chirped-probe pulse femtosecond coherent anti-Stokes Raman scattering thermometry

    KAUST Repository

    Gu, Mingming

    2018-01-08

    The effects of moderate levels of chirp in the pump and Stokes pulses on chirped-probe-pulse femtosecond coherent anti-Stokes Raman scattering (CPP fs CARS) were investigated. The frequency chirp in the pump and Stokes pulses was introduced by placing SF11 glass disks with thicknesses of 10 mm or 20 mm in the optical path for these beams. The magnitude of the chirp in the probe beam was much greater and was induced by placing a 30-cm rod of SF10 glass in the beam path. The temperature measurements were performed in hydrogen/air non-premixed flames stabilized on a Hencken burner at equivalence ratios of 0.3, 0.5, 0.7, and 1.0. We performed measurements with no disks in pump and Stokes beam paths, and then with disks of 10 mm and 20 mm placed in both beam paths. The spectrum of the nonresonant background four-wave mixing signal narrowed considerably with increasing pump and Stokes chirp, while the resonant CARS signal was relatively unaffected. Consequently, the interference of the nonresonant background with the resonant CARS signal in the frequency-spread dephasing region of the spectrum was minimized. The increased rate of decay of the resonant CARS signal with increasing temperature was thus readily apparent. We have started to analyze the CPP fs CARS thermometry data and initial results indicate improved accuracy and precision are obtained due to moderate chirp in the pump and Stokes laser pulses.

  19. Thermal Noise Canceling in LNAs: A Review

    OpenAIRE

    Nauta, Bram; Klumperink, Eric A.M.; Bruccoleri, Frederico

    2004-01-01

    Most wide-band amplifiers suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and its key properties. Although the technique has been applied to wideband CMOS LNAs, it can just as well be implemented exploiting transconductance elements realized with other types of t...

  20. Sparse adaptive filters for echo cancellation

    CERN Document Server

    Paleologu, Constantin

    2011-01-01

    Adaptive filters with a large number of coefficients are usually involved in both network and acoustic echo cancellation. Consequently, it is important to improve the convergence rate and tracking of the conventional algorithms used for these applications. This can be achieved by exploiting the sparseness character of the echo paths. Identification of sparse impulse responses was addressed mainly in the last decade with the development of the so-called ``proportionate''-type algorithms. The goal of this book is to present the most important sparse adaptive filters developed for echo cancellati

  1. Anomaly cancellation for super-W-gravity

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, P. (Dept. of Theoretical Physics, Univ. of Oxford (United Kingdom)); Spence, B. (Dept. of Physics, Univ. of Southampton (United Kingdom))

    1991-08-08

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super-W-gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N=1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. (orig.).

  2. Anomaly cancellation for super- W -gravity

    Science.gov (United States)

    Mansfield, P.; Spence, B.

    1991-08-01

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super- W -gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N = 1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. Address from 1 October 1991: Physics Department, Imperial College, London SW7 2BZ, UK.

  3. Anomaly cancellation for super-W-gravity

    International Nuclear Information System (INIS)

    Mansfield, P.; Spence, B.

    1991-01-01

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super-W-gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N=1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. (orig.)

  4. The role of socio-demographic variables and their interaction effect on sense of coherence

    Directory of Open Access Journals (Sweden)

    Antoni Barnard

    2013-10-01

    Research purpose: To explore whether and how socio-demographic variables and their interactive effect determine a distinctively high or low SOC. Motivation for the study: Various studies include an exploration of the role of socio-demographic attributes on SOC, yet do not investigate the interactive effect of these socio-demographics on high or low SOC. Research design, approach and method: Quantitative, cross-sectional survey design. The chi-square interaction detection method (CHAID was applied to a large-scale employee sample (n = 7185. Confirmatory analysis was done by exploring predictor effects on two possible permutations of high or low SOC classifications. Main findings: Results indicated a statistically significant four-factor interactive effect of demographic variables on SOC. Level of income most strongly partitioned high to low SOC ratio groups. Marital status and number of dependants, with level of income, further distinguished statistically distinct high to low SOC ratio groups. Race indicated distinct high to low SOC ratio groups in the higher income group. No statistically significant effects were found for age and gender. Practical/managerial implications: Companies should provide lower income employees with financial counselling and special support for single or divorced employees and employees who are married but the sole household earner. In the middle to high income category employee assistance should cater for employees with dependants and especially for the sole household earners. Contribution/value-add: Establishing whether and how demographic variables predict high to low SOC ratios broadens the theoretical knowledge base of SOC. The study contributes methodologically in its application of CHAID analysis.

  5. 5 CFR 894.602 - May I cancel my enrollment at any time?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false May I cancel my enrollment at any time... Cancellation of Coverage § 894.602 May I cancel my enrollment at any time? No. You may only cancel your enrollment during an open season. Exceptions: You may cancel your dental and/or vision enrollment if you...

  6. 5 CFR 837.803 - Cancellation of retirement by judicial or administrative authority.

    Science.gov (United States)

    2010-01-01

    ... Canceled Retirements § 837.803 Cancellation of retirement by judicial or administrative authority. (a... may only be canceled by the former employing agency in response to a direct and final order of a... requiring cancellation of the annuitant's separation or after the annuitant and the agency agree to cancel...

  7. CRYSTAL simulation code and modeling of coherent effects in a bent crystal at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Sytov, A.I., E-mail: alex_sytov@mail.ru [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya str., 11, 220030 Minsk (Belarus); INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Tikhomirov, V.V., E-mail: vvtikh@mail.ru [Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya str., 11, 220030 Minsk (Belarus)

    2015-07-15

    A CRYSTAL simulation code for particle tracking in crystals is introduced. Its essence consists in both adequate and fast sampling of proton trajectories in crystals which is crucial for both correct description of experiments and quantitative prediction of new effects. The H8 single-pass experiment at the CERN SPS as well as 7 TeV proton deflection by a bent crystal at the LHC are simulated. We predict the existence of dechanneling peaks corresponding to the planar channeling oscillations as well as describe the possibility of their observation at high energies, specifically at the LHC energy. An effect of excess over the amorphous level of ionization losses in the channeling mode was also found at 7 TeV.

  8. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    Science.gov (United States)

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  9. Geometric phase effects in the coherent control of the branching ratio of photodissociation products of phenol

    International Nuclear Information System (INIS)

    Abe, Mayumi; Ohtsuki, Yukiyoshi; Fujimura, Yuichi; Lan, Zhenggang; Domcke, Wolfgang

    2006-01-01

    Optimal control simulation is used to examine the control mechanisms in the photodissociation of phenol within a two-dimensional, three-electronic-state model with two conical intersections. This model has two channels for H-atom elimination, which correspond to the 2 π and 2 σ states of the phenoxyl radical. The optimal pulse that enhances 2 σ dissociation initially generates a wave packet on the S 1 potential-energy surface of phenol. This wave packet is bifurcated at the S 2 -S 1 conical intersection into two components with opposite phases because of the geometric phase effect. The destructive interference caused by the geometric phase effect reduces the population around the S 1 -S 0 conical intersection, which in turn suppresses nonadiabatic transitions and thus enhances dissociation to the 2 σ limit. The optimal pulse that enhances S 0 dissociation, on the other hand, creates a wave packet on the S 2 potential-energy surface of phenol via an intensity borrowing mechanism, thus avoiding geometric phase effects at the S 2 -S 1 conical intersection. This wave packet hits the S 1 -S 0 conical intersection directly, resulting in preferred dissociation to the 2 π limit. The optimal pulse that initially prepares the wave packet on the S 1 potential-energy surface (PES) has a higher carrier frequency than the pulse that prepares the wave packet on the S 2 PES. This counterintuitive effect is explained by the energy-level structure and the S 2 -S 1 vibronic coupling mechanism

  10. Effects of optical attenuation, heat diffusion, and acoustic coherence in photoacoustic signals produced by nanoparticles

    Science.gov (United States)

    Alba-Rosales, J. E.; Ramos-Ortiz, G.; Escamilla-Herrera, L. F.; Reyes-Ramírez, B.; Polo-Parada, L.; Gutiérrez-Juárez, G.

    2018-04-01

    The behavior of the photoacoustic signal produced by nanoparticles as a function of their concentration was studied in detail. As the concentration of nanoparticles is increased in a sample, the peak-to-peak photoacoustic amplitude increases linearly up to a certain value, after which an asymptotic saturated behavior is observed. To elucidate the mechanisms responsible for these observations, we evaluate the effects of nanoparticles concentration, the optical attenuation, and the effects of heat propagation from nano-sources to their surroundings. We found that the saturation effect of the photoacoustic signal as a function of the concentration of nanoparticles is explained by a combination of two different mechanisms. As has been suggested previously, but not modeled correctly, the most important mechanism is attributed to optical attenuation. The second mechanism is due to an interference destructive process attributed to the superimposition of the photoacoustic amplitudes generated for each nanoparticle, and this explanation is reinforced through our experimental and simulations results; based on this, it is found that the linear behavior of the photoacoustic amplitude could be restricted to optical densities ≤0.5.

  11. 77 FR 75157 - Notice of Receipt of a Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2012-12-19

    ... existing stocks: No sale or distribution of allethrins technical products by any person, other than for... period that would merit its further review of the request, or unless the registrants withdraw their request. The cancellation for the allethrins technical products will be effective September 30, 2015, and...

  12. A simulation experiment and analysis on the effects of in-coherence in fuel coolant interaction

    International Nuclear Information System (INIS)

    Kondo, S.; Togo, Y.; Iwamura, T.

    1976-01-01

    Experimental and analytical studies were conducted to investigate effects of incoherence (space time behavior of molten fuel) on molten fuel coolant interaction. In experiments, a 2 mm diameter molten tin jet was injected upward into the water in a slender tank. The results were analyzed based on the pressure records and high speed photographs. The pressure records indicated that there were two types of interaction between molten jet and water, intermittent explosion mode and continuous one. The explosion mode appeared when the temperature of molten tin was above 350 0 C or so and that of water was below 70 0 C or so. The high speed photograph indicated that an establishment of a stable jet column was necessary for an explosive interaction and that a bubble like region grew and collapsed at the root of the jet in accordance with the generation of pressure pulse. It was found that the mass of metal which contributed to the vapor explosion was only a small part of the injected metal in the case of jet injection type contact mode and this was the reason why the gross thermal to mechanical energy conversion ratio was around 0.03% in this type of contact mode, though this ratio was around 2% if only the part of record around the pressure pulse was taken into consideration. In the analysis part, a multi-channel FCI model was developed to evaluate the spatial incoherence effect on pressure at subassembly exit. The calculated pressure trace indicated that the spatial incoherence has considerable effects for an evaluation of structure response under FCI pressure loading. (auth.)

  13. Cohering power of quantum operations

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Kaifeng, E-mail: bkf@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China); Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Zhang, Lin, E-mail: linyz@zju.edu.cn [Institute of Mathematics, Hangzhou Dianzi University, Hangzhou 310018 (China); Wu, Junde, E-mail: wjd@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China)

    2017-05-18

    Highlights: • Quantum coherence. • Cohering power: production of quantum coherence by quantum operations. • Study of cohering power and generalized cohering power, and their comparison for differentmeasures of quantum coherence. • Operational interpretation of cohering power. • Bound on cohering power of a generic quantum operation. - Abstract: Quantum coherence and entanglement, which play a crucial role in quantum information processing tasks, are usually fragile under decoherence. Therefore, the production of quantum coherence by quantum operations is important to preserve quantum correlations including entanglement. In this paper, we study cohering power–the ability of quantum operations to produce coherence. First, we provide an operational interpretation of cohering power. Then, we decompose a generic quantum operation into three basic operations, namely, unitary, appending and dismissal operations, and show that the cohering power of any quantum operation is upper bounded by the corresponding unitary operation. Furthermore, we compare cohering power and generalized cohering power of quantum operations for different measures of coherence.

  14. Effect of the depolarization field on coherent optical properties in semiconductor quantum dots

    Science.gov (United States)

    Mitsumori, Yasuyoshi; Watanabe, Shunta; Asakura, Kenta; Seki, Keisuke; Edamatsu, Keiichi; Akahane, Kouichi; Yamamoto, Naokatsu

    2018-06-01

    We study the photon echo spectrum of self-assembled semiconductor quantum dots using femtosecond light pulses. The spectrum shape changes from a single-peaked to a double-peaked structure as the time delay between the two excitation pulses is increased. The spectrum change is reproduced by numerical calculations, which include the depolarization field induced by the biexciton-exciton transition as well as the conventional local-field effect for the exciton-ground-state transition in a quantum dot. Our findings suggest that various optical transitions in tightly localized systems generate a depolarization field, which renormalizes the resonant frequency with a change in the polarization itself, leading to unique optical properties.

  15. Partially coherent imaging and spatial coherence wavelets

    International Nuclear Information System (INIS)

    Castaneda, Roman

    2003-03-01

    A description of spatially partially coherent imaging based on the propagation of second order spatial coherence wavelets and marginal power spectra (Wigner distribution functions) is presented. In this dynamics, the spatial coherence wavelets will be affected by the system through its elementary transfer function. The consistency of the model with the both extreme cases of full coherent and incoherent imaging was proved. In the last case we obtained the classical concept of optical transfer function as a simple integral of the elementary transfer function. Furthermore, the elementary incoherent response function was introduced as the Fourier transform of the elementary transfer function. It describes the propagation of spatial coherence wavelets form each object point to each image point through a specific point on the pupil planes. The point spread function of the system was obtained by a simple integral of the elementary incoherent response function. (author)

  16. Cancellation of the centrifugal space-charge force

    International Nuclear Information System (INIS)

    Lee, E.P.

    1990-01-01

    The transverse dynamics of high-energy electrons confined in curved geometry are examined, including the effects of space-charge-induced fields. Attention is restricted to the centrifugal-space-charge force, which is the result of noncancellation of beam-induced transverse electric and magnetic fields in the curved geometry. This force is shown to be nearly cancelled in the evaluation of the horizontal tune and chromaticity by another, often overlooked term in the equation of motion. The additional term is the consequence of oscillations of the kinetic energy, which accompany betatron oscillations in the beam-induced electric potential. In curved geometry this term is of first order in the amplitude of the radial oscillation. A highly simplified system model is employed so that physical effects appear in as clear a form as possible. We assume azimuthal and median plane symmetry, static fields, and ultrarelativistic particle velocity (1/γ 2 ->0). (author) 9 refs

  17. The coherence lifetime-borrowing effect in vibronically coupled molecular aggregates under non-perturbative system-environment interactions.

    Science.gov (United States)

    Yeh, Shu-Hao; Engel, Gregory S.; Kais, Sabre

    Recently it has been suggested that the long-lived coherences in some photosynthetic pigment-protein systems, such as the Fenna-Matthews-Olson complex, could be attributed to the mixing of the pigments' electronic and vibrational degrees of freedom. In order to verify whether this is the case and to understand its underlying mechanism, a theoretical model capable of including both the electronic excitations and intramolecular vibrational modes of the pigments is necessary. Our model simultaneously considers the electronic and vibrational degrees of freedom, treating the system-environment interactions non-perturbatively by implementing the hierarchical equations of motion approach. Here we report the simulated two-dimensional electronic spectra of vibronically coupled molecular dimers to demonstrate how the electronic coherence lifetimes can be extended by borrowing the lifetime from the vibrational coherences. Funded by Qatar National Research Fund and Qatar Environment and Energy Research Institute.

  18. Laser diode technology for coherent communications

    Science.gov (United States)

    Channin, D. J.; Palfrey, S. L.; Toda, M.

    1989-01-01

    The effect of diode laser characteristics on the overall performance capabilities of coherent communication systems is discussed. In particular, attention is given to optical performance issues for diode lasers in coherent systems, measurements of key performance parameters, and optical requirements for coherent single-channel and multichannel communication systems. The discussion also covers limitations imposed by diode laser optical performance on multichannel system capabilities and implications for future developments.

  19. Characteristics of noise-canceling headphones to reduce the hearing hazard for MP3 users.

    Science.gov (United States)

    Liang, Maojin; Zhao, Fei; French, David; Zheng, Yiqing

    2012-06-01

    Three pairs of headphones [standard iPod ear buds and two noise-canceling headphones (NCHs)] were chosen to investigate frequency characteristics of noise reduction, together with their attenuation effects on preferred listening levels (PLLs) in the presence of various types of background noise. Twenty-six subjects with normal hearing chose their PLLs in quiet, street noise, and subway noise using the three headphones and with the noise-canceling system on/off. Both sets of NCHs reduced noise levels at mid- and high-frequencies. Further noise reductions occurred in low frequencies with the noise canceling system switched on. In street noise, both NCHs had similar noise reduction effects. In subway noise, better noise reduction effects were found in the expensive NCH and with noise-canceling on. A two way repeated measures analysis of variance showed that both listening conditions and headphone styles were significant influencing factors on the PLLs. Subjects tended to increase their PLLs as the background noise level increased. Compared with ear buds, PLLs obtained from NCHs-on in the presence of background noise were reduced up to 4 dB. Therefore, proper selection and use of NCHs appears beneficial in reducing the risk of hearing damage caused by high music listening levels in the presence of background noise.

  20. Coherent coupling between radio frequency, optical, and acoustic waves in piezo-optomechanical circuits

    Science.gov (United States)

    Balram, Krishna C.; Davanço, Marcelo I.; Song, Jin Dong; Srinivasan, Kartik

    2016-01-01

    Optomechanical cavities have been studied for applications ranging from sensing to quantum information science. Here, we develop a platform for nanoscale cavity optomechanical circuits in which optomechanical cavities supporting co-localized 1550 nm photons and 2.4 GHz phonons are combined with photonic and phononic waveguides. Working in GaAs facilitates manipulation of the localized mechanical mode either with a radio frequency (RF) field through the piezo-electric effect, which produces acoustic waves that are routed and coupled to the optomechanical cavity by phononic crystal waveguides, or optically through the strong photoelastic effect. Along with mechanical state preparation and sensitive readout, we use this to demonstrate an acoustic wave interference effect, similar to atomic coherent population trapping, in which RF-driven coherent mechanical motion is cancelled by optically-driven motion. Manipulating cavity optomechanical systems with equal facility through both photonic and phononic channels enables new architectures for signal transduction between the optical, electrical, and mechanical domains. PMID:27446234

  1. Photons and dileptons production in a quark gluon plasma: infrared structure and coherent scattering effects; Production de photons et de dileptons dans un plasma de quarks et de gluons: structure infrarouge et effets coherents

    Energy Technology Data Exchange (ETDEWEB)

    Zaraket, H

    2000-06-01

    This work is devoted to photon and dilepton production in a quark gluon plasma. The theoretical framework in which the study is carried out is Thermal Field Theory, more precisely the hard thermal loop effective theory. Several features of the observables preclude a straightforward application of the effective theory and new tools had to be developed such as the counter term method to avoid double counting. The first part of my study concerns static virtual photon production where I show that important physical contributions are missing in the effective theory at one loop level and hence a two loop calculation is indispensable. Furthermore I give an analytic leading logarithmic estimate of this two loop result showing clearly the insufficiency of the effective theory. The second part of the work focuses on real and quasi real photon production. Again, important contributions arise at two loop level due to collinear divergences. For high mass dilepton the two loop calculation is sufficient. On the other hand, near the light cone photon production rate is non perturbative. Getting closer to the light cone coherent scattering effects (Landau-Pomeranchuk-Migdal effect) arise, which imply the resummation of an infinite series of diagrams. Still nearer the light cone we found a dependence on the non perturbative magnetic mass due to infrared singularities. (author)

  2. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    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. Second-order Monte Carlo wave-function approach to the relaxation effects on ringing revivals in a molecular system interacting with a strongly squeezed coherent field

    International Nuclear Information System (INIS)

    Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Yamaguchi, Kizashi

    2004-01-01

    We investigate the relaxation effects on the quantum dynamics in a two-state molecular system interacting with a single-mode strongly amplitude-squeezed coherent field using the second-order Monte Carlo wave-function method. The molecular population inversion (collapse-revival behavior of Rabi oscillations) is known to show the echoes after each revival, which are referred to as ringing revivals, in the case of strongly squeezed coherent fields with oscillatory photon-number distributions due to the phase-space interference effect. Two types of relaxation effects, i.e., cavity relaxation (the dissipation of an internal single mode to outer mode) and molecular coherent (phase) relaxation caused by nuclear vibrations on ringing revivals are investigated from the viewpoint of the quantum-phase dynamics using the quasiprobability (Q function) distribution of a single-mode field and the off-diagonal molecular density matrix ρ elec1,2 (t). It turns out that the molecular phase relaxation attenuates both the entire revival-collapse behavior and the increase in ρ elec1,2 (t) during the quiescent region, whereas a very slight cavity relaxation particularly suppresses the echoes in ringing revivals more significantly than the first revival but hardly changes a primary variation in envelope of ρ elec1,2 (t) in the nonrelaxation case

  4. 75 FR 51053 - Propetamphos; Notice of Receipt of Requests to Voluntarily Cancel Pesticide Registrations

    Science.gov (United States)

    2010-08-18

    ... of Requests to Voluntarily Cancel Pesticide Registrations AGENCY: Environmental Protection Agency... registrant, Wellmark International, to voluntarily cancel its registrations of products containing the... registrations have been canceled only if such sale, distribution, or use is consistent with the terms as...

  5. 75 FR 51048 - Notice of Receipt of Request to Voluntarily Cancel a Pesticide Registration

    Science.gov (United States)

    2010-08-18

    ... Voluntarily Cancel a Pesticide Registration AGENCY: Environmental Protection Agency (EPA). ACTION: Notice... cancel a pesticide registration. DATES: Comments must be received on or before September 17, 2010... the registrant to cancel a technical grade active ingredient pesticide product registered under...

  6. 75 FR 70256 - Tralomethrin; Notice of Receipt of Request To Voluntarily Cancel Pesticide Registrations

    Science.gov (United States)

    2010-11-17

    ... of Request To Voluntarily Cancel Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel their registrations of products containing the pesticide tralomethrin. The request would... will cancel the sole technical product registration for tralomethrin. EPA intends to grant this request...

  7. 75 FR 5318 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-02-02

    ... to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel certain pesticide registrations. DATES: Unless a request is withdrawn by or March 4, 2010... will be issued canceling these registrations. The Agency will consider withdrawal requests postmarked...

  8. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  9. 50 CFR 228.13 - Determination to cancel the hearing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Determination to cancel the hearing. 228.13 Section 228.13 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND...) REGULATIONS § 228.13 Determination to cancel the hearing. (a) If the presiding officer concludes that no...

  10. Outage Performance in Cognitive Radio Systems with Opportunistic Interference Cancelation

    DEFF Research Database (Denmark)

    Di Taranto, Rocco; Popovski, Petar

    2011-01-01

    , respectively. The secondary receiver applies Opportunistic Interference Cancelation (OIC) and Suboptimal Opportunistic Interference Cancelation (S-OIC) thus decoding the primary signal when such an opportunity is created by the rate selected at the primary transmitter and the power received from the primary...

  11. Revenue management under customer choice behaviour with cancellations and overbooking

    NARCIS (Netherlands)

    Sierag, D.D.; Koole, G.M.; Mei, van der R.D.; Zwart, B.; Rest, van der J.I.

    2015-01-01

    In many application areas such as airlines and hotels a large number of bookings are typically cancelled. Explicitly taking into account cancellations creates an opportunity for increasing revenue. Motivated by this we propose a revenue management model based on Talluri and van Ryzin (2004) that

  12. 42 CFR 57.313a - Loan cancellation reimbursement.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Loan cancellation reimbursement. 57.313a Section 57.313a Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR... Loans § 57.313a Loan cancellation reimbursement. In the event that insufficient funds are available to...

  13. 42 CFR 57.213a - Loan cancellation reimbursement.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Loan cancellation reimbursement. 57.213a Section 57... Professions Student Loans § 57.213a Loan cancellation reimbursement. (a) For loans made prior to October 22... credited to this insurance fund), and used only to reimburse the school for the institutional share of any...

  14. 27 CFR 479.87 - Cancellation of stamp.

    Science.gov (United States)

    2010-04-01

    ... OTHER FIREARMS Transfer Tax Application and Order for Transfer of Firearm § 479.87 Cancellation of stamp. The method of cancellation of the stamp required by this subpart as prescribed in § 479.67 shall be used. Exemptions Relating to Transfers of Firearms ...

  15. A new pathway for elective surgery to reduce cancellation rates

    DEFF Research Database (Denmark)

    Hovlid, Einar; Bukve, Oddbjørn; Haug, Kjell

    2012-01-01

    The cancellation of planned surgeries causes prolonged wait times, harm to patients, and is a waste of scarce resources. To reduce high cancellation rates in a Norwegian general hospital, the pathway for elective surgery was redesigned. The changes included earlier clinical assessment of patients...

  16. 78 FR 48456 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2013-08-08

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: Customs broker license cancellations. SUMMARY: Notice is hereby given that the customs broker...

  17. 76 FR 16843 - Order Cancelling Registrations of Certain Transfer Agents

    Science.gov (United States)

    2011-03-25

    ... existence or has ceased to do business as a transfer agent, the Commission shall by order cancel that... name appears in the attached Appendix either is no longer in existence or has ceased doing business as... cancel the registration of certain transfer agents whom it believed were no longer in existence or had...

  18. RATES OF PHOTOSPHERIC MAGNETIC FLUX CANCELLATION MEASURED WITH HINODE

    International Nuclear Information System (INIS)

    Park, Soyoung; Chae, Jongchul; Litvinenko, Yuri E.

    2009-01-01

    Photospheric magnetic flux cancellation on the Sun is generally believed to be caused by magnetic reconnection occurring in the low solar atmosphere. Individual canceling magnetic features are observationally characterized by the rate of flux cancellation. The specific cancellation rate, defined as the rate of flux cancellation divided by the interface length, gives an accurate estimate of the electric field in the reconnecting current sheet. We have determined the specific cancellation rate using the magnetograms taken by the Solar Optical Telescope (SOT) aboard the Hinode satellite. The specific rates determined with SOT turned out to be systematically higher than those based on the data taken by the Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory. The median value of the specific cancellation rate was found to be 8 x 10 6 G cm s -1 -a value four times that obtained from the MDI data. This big difference is mainly due to a higher angular resolution and better sensitivity of the SOT, resulting in magnetic fluxes up to five times larger than those obtained from the MDI. The higher rates of flux cancellation correspond to either faster inflows or stronger magnetic fields of the reconnection inflow region, which may have important consequences for the physics of photospheric magnetic reconnection.

  19. 19 CFR 113.55 - Cancellation of export bonds.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Cancellation of export bonds. 113.55 Section 113... export bonds. (a) Manner of cancellation. A bond to assure exportation as defined in § 101.1 of this... shall be signed by a revenue officer of the foreign country to which the merchandise is exported, unless...

  20. Adaptive Feedback Cancellation With Band-Limited LPC Vocoder in Digital Hearing Aids

    DEFF Research Database (Denmark)

    Ma, Guilin; Gran, Fredrik; Jacobsen, Finn

    2011-01-01

    Feedback oscillation is one of the major issues with hearing aids. An effective way of feedback suppression is adaptive feedback cancellation, which uses an adaptive filter to estimate the feedback path. However, when the external input signal is correlated with the receiver input signal, the est......Feedback oscillation is one of the major issues with hearing aids. An effective way of feedback suppression is adaptive feedback cancellation, which uses an adaptive filter to estimate the feedback path. However, when the external input signal is correlated with the receiver input signal......, the estimate of the feedback path is biased. This so-called “bias problem” results in a large modeling error and a cancellation of the desired signal. This paper proposes a band-limited linear predictive coding based approach to reduce the bias. The idea is to replace the hearing-aid output with a synthesized...... and the misalignment between the real and the estimated feedback path. When combined with filtered-X adaptation in the feedback canceller, this approach reduces the misalignment even further....

  1. Two-dimensional spectroscopy of a molecular dimer unveils the effects of vibronic coupling on exciton coherences

    NARCIS (Netherlands)

    Halpin, Alexei; Johnson, Philip J. M.; Tempelaar, Roel; Murphy, R. Scott; Knoester, Jasper; Jansen, Thomas L. C.; Miller, R. J. Dwayne

    The observation of persistent oscillatory signals in multidimensional spectra of protein-pigment complexes has spurred a debate on the role of coherence-assisted electronic energy transfer as a key operating principle in photosynthesis. Vibronic coupling has recently been proposed as an explanation

  2. Effects of phase and coupling between the vibrational modes on selective excitation in coherent anti-Stokes Raman scattering microscopy

    International Nuclear Information System (INIS)

    Patel, Vishesha; Malinovsky, Vladimir S.; Malinovskaya, Svetlana

    2010-01-01

    Coherent anti-Stokes Raman scattering (CARS) microscopy has been a major tool of investigation of biological structures as it contains the vibrational signature of molecules. A quantum control method based on chirped pulse adiabatic passage was recently proposed for selective excitation of a predetermined vibrational mode in CARS microscopy [Malinovskaya and Malinovsky, Opt. Lett. 32, 707 (2007)]. The method utilizes the chirp sign variation at the peak pulse amplitude and gives a robust adiabatic excitation of the desired vibrational mode. Using this method, we investigate the impact of coupling between vibrational modes in molecules on controllability of excitation of the CARS signal. We analyze two models of two coupled two-level systems (TLSs) having slightly different transitional frequencies. The first model, featuring degenerate ground states of the TLSs, gives robust adiabatic excitation and maximum coherence in the resonant TLS for positive value of the chirp. In the second model, implying nondegenerate ground states in the TLSs, a population distribution is observed in both TLSs, resulting in a lack of selectivity of excitation and low coherence. It is shown that the relative phase and coupling between the TLSs play an important role in optimizing coherence in the desired vibrational mode and suppressing unwanted transitions in CARS microscopy.

  3. A Nonlinear Adaptive Filter for Gyro Thermal Bias Error Cancellation

    Science.gov (United States)

    Galante, Joseph M.; Sanner, Robert M.

    2012-01-01

    Deterministic errors in angular rate gyros, such as thermal biases, can have a significant impact on spacecraft attitude knowledge. In particular, thermal biases are often the dominant error source in MEMS gyros after calibration. Filters, such as J\\,fEKFs, are commonly used to mitigate the impact of gyro errors and gyro noise on spacecraft closed loop pointing accuracy, but often have difficulty in rapidly changing thermal environments and can be computationally expensive. In this report an existing nonlinear adaptive filter is used as the basis for a new nonlinear adaptive filter designed to estimate and cancel thermal bias effects. A description of the filter is presented along with an implementation suitable for discrete-time applications. A simulation analysis demonstrates the performance of the filter in the presence of noisy measurements and provides a comparison with existing techniques.

  4. Superradiance from an ultrathin film of three-level V-type atoms: interplay between splitting, quantum coherence and local-field effects

    International Nuclear Information System (INIS)

    Malyshev, V A; Carreno, F; Anton, M A; Calderon, Oscar G; Dominguez-Adame, F

    2003-01-01

    We carry out a theoretical study of the collective spontaneous emission (superradiance) from an ultrathin film comprised of three-level atoms with V configuration of the operating transitions. As the thickness of the system is small compared to the emission wavelength inside the film, the local-field correction to the averaged Maxwell field is relevant. We show that the interplay between the low-frequency quantum coherence within the subspace of the upper doublet states and the local-field correction may drastically affect the branching ratio of the operating transitions. This effect may be used for controlling the emission process by varying the doublet splitting and the amount of low-frequency coherence

  5. Effect of angular-momentum dissipation and fluctuation on energy coherence lengths and time evolution in the dissipative collision 28Si+48Ti

    International Nuclear Information System (INIS)

    Kun, S.Yu.; WITS Univ., Johannesburg; Noerenberg, W.; TH Darmstadt; Papa, M.

    1992-09-01

    We analyze the energy autocorrelation functions and the energy coherence lengths in the strongly dissipative collision 28 Si(E lab = 130 MeV) + 4 8Ti for Z=11 and 12 reaction fragments. It is found that in order to obtain a good fit of both the energy averaged angular distributions and the angular dependence of the energy coherence lengths one has to take into account (i) the dissipation and fluctuation of the relative angular momentum of the dinucleus and (ii) the contribution from direct (fast) reactions in addition to the statistical (relatively slow) interaction processes. The established angular dependence is a direct consequence of the angular-momentum dissipation-fluctuation effects on the time-space evolution of the intermediate dinucleus. (orig.)

  6. Coherent effects in relativistic electron beams radiation in the presence of beat waves; Kogerentnye ehffekty v izluchenii relyativistskogo ehlektronnogo sgustka pri nalichii voln bienij

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgyan, L A; Shamamian, A N

    1992-12-31

    The problem of relativistic electron beam-laser beat waves interaction is considered. Due to interaction the electron density is changed as opposed to the case, when it interacts with still electron plasma, the change of density gets less. But it is interesting to research the coherent spontaneous radiation of the electron beam interacting with. It is shown that this interaction brings to an increase of the partial coherent effect. The radiation efficiency depends essentially on the beam parameters, i.e. on the radio of the distinctive longitudinal dimension density. The maximum amplification takes place when the beam length makes room for an odd number of wave length quarters. Since the gain factor decreases with the radiation wave length, we offer to use high-current relativistic electron beams to generate micro radio waves. 4 refs.

  7. Coherent hole burning and Mollow absorption effects in the cycling transition Fe=0↔Fg=1 subject to a magnetic field

    International Nuclear Information System (INIS)

    Gu Ying; Sun Qingqing; Gong Qihuang

    2004-01-01

    With saturation and probing by circularly polarized fields, quantum coherence effects are investigated for the cycling transition F e =0↔F g =1, which is subject to a linearly polarized field and a magnetic field. The saturation field is applied to the case of maximum coherence between the drive Rabi frequency and magnetic field, corresponding to the electromagnetically induced absorption (EIA) with negative dispersion found by Gu et al. For a small saturation Rabi frequency, holes are burned in two Autler-Towns peaks outside two symmetric electromagnetically induced transparency windows due to the two-photon resonance. However, when the saturation Rabi frequency is comparable with the drive Rabi frequency, holes caused by the coherent population oscillation appear in the EIA spectrum. Finally, when the saturation Rabi frequency is large enough, several emission peaks are observed due to the Mollow absorption effects. Furthermore, the dispersion at the pump-probe detuning center is kept negative with an increase in saturation field, which is a precursor of superluminal light propagation

  8. 脱蛋白松质骨作为异种骨移植材料的修复作用%Repair effect of deproteinised cancellous bone as xenogeneic bone graft material

    Institute of Scientific and Technical Information of China (English)

    高春阳; 姜宏春; 金春明

    2011-01-01

    BACKGROUND: Unequal size, mutual communication, and open pore network structure can be seen in cancellous bone treated with deproteinization. Its inorganic component is hydroxyapatite, and the organic component is collagen, which has a good mechanical property and biocompatibility. It may be a new type of bone graft material.OBJECTIVE: To study the properties of xenogeneic deproteinised cancellous bone being carrier of bone tissue engineering in bone fusion.METHODS: Taking “xenogeneic deproteinised cancellous bone, bone fusion, carrier” in Chinese as search terms, the articles from January 1998 to December 2009 in VIP database, CNKI database, Pubmed database were retrieved by computer. The relevant literatures were included, the literature of irrelevant purpose and repetitive content were excluded, and 33 of them were involved for further analysis.RESULTS AND CONCLUSION: Compared with synthetic bone material, animal bones have similar biomaterial structure, modeling, excellent cell attachment, and cell growth and proliferation environment. However, the compatibility of bone tissue is poor, because of the differences in species when xenogeneic deproteinised cancellous bone transplantation, and gravis immune rejection, the key question is implantation of immune problems. How to overcome immunogenicity, xenogeneic deproteinised cancellous bone is a good carrier of bone tissue engineering, which can provide a stable environment for revascularization and differentiation of osteoblasts.%背景:采用脱蛋白处理后的松质骨可见大小不等、相互交通、开放孔隙的网架结构,其无机成分为羟基磷灰石,有机成分为胶原,力学性能保存良好,有良好的细胞相容性,可能是一种新型骨移植材料.目的:介绍异种脱蛋白松质骨作为骨组织工程载体的性能,以及其用于骨融合的作用.方法:分别以"异种脱蛋白松质骨、骨融合、载体",为检索词,应用计算机检索重庆

  9. CERN Library - Journal cancellations in 2008

    CERN Multimedia

    2007-01-01

    In 2007, the CERN Library has been allocated a smaller budget than in 2006. Since subscriptions must be paid in advance, the current budget is being used to pay the journal collection for the year 2008 and is unfortunately not sufficient to maintain the information resources at the 2007 level. Consequently, the Working Group for Acquisitions (WGA) was obliged to identify candidates for cancellation for 2008. The list of candidates is shown here. As in the past, readers will be able to order articles from journals not available in the CERN Library through the Interlibrary Loan (ILL) service; generally articles are sent within 24h. Library users are invited to send comments on this proposal not later than 4 August 2007 to the WGA Chairman, Rudiger Voss, with a copy to the Head Librarian, Jens Vigen.

  10. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  11. Nuclear cancellations follow-on study

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-29

    The serious reduction in the aggregate commitment to nuclear power by US utilities over the past few years, as well as the serious stretchout of the completion schedules for many ongoing projects, has continued. A 1980 study which studied the factors causing this retrenchment is discussed. In this 1982 study, utilities were interviewed in an attempt to identify possible remedies which the Federal government might take to induce utilities to postpone rather than cancel units less than 10% complete, and to complete expeditiously units in the 10 to 60% completion range. The quality of the reserve margin is examined. The actions of state regulators are considered. Regulatory reform emerges as the key action the Federal government can take. (DLC)

  12. Use of active noise cancellation devices in caregivers in the intensive care unit.

    Science.gov (United States)

    Akhtar, S; Weigle, C G; Cheng, E Y; Toohill, R; Berens, R J

    2000-04-01

    Recent development of noise cancellation devices may offer relief from noise in the intensive care unit environment. This study was conducted to evaluate the effect of noise cancellation devices on subjective hearing assessment by caregivers in the intensive care units. Randomized, double-blind. Adult medical intensive care unit and pediatric intensive care unit of a teaching hospital. Caregivers of patients, including nurses, parents, respiratory therapists, and nursing assistants from a medical intensive care unit and pediatric intensive care, were enrolled in the study. Each participant was asked to wear the headphones, functional or nonfunctional noise cancellation devices, for a minimum of 30 mins. Subjective ambient noise level was assessed on a 10-point visual analog scale (VAS) before and during headphone use by each participant. Headphone comfort and the preference of the caregiver to wear the headphone were also evaluated on a 10-point VAS. Simultaneously, objective measurement of noise was done with a sound level meter using the decibel-A scale and at each of nine octave bands at each bedspace. The functional headphones significantly reduced the subjective assessment of noise by 2 (out of 10) VAS points (p noise profiles, based on decibel-A and octave band assessments. Noise cancellation devices improve subjective assessment of noise in caretakers. The benefit of these devices on hearing loss needs further evaluation in caregivers and critically ill patients.

  13. Coherent time-stretch transformation for real-time capture of wideband signals.

    Science.gov (United States)

    Buckley, Brandon W; Madni, Asad M; Jalali, Bahram

    2013-09-09

    Time stretch transformation of wideband waveforms boosts the performance of analog-to-digital converters and digital signal processors by slowing down analog electrical signals before digitization. The transform is based on dispersive Fourier transformation implemented in the optical domain. A coherent receiver would be ideal for capturing the time-stretched optical signal. Coherent receivers offer improved sensitivity, allow for digital cancellation of dispersion-induced impairments and optical nonlinearities, and enable decoding of phase-modulated optical data formats. Because time-stretch uses a chirped broadband (>1 THz) optical carrier, a new coherent detection technique is required. In this paper, we introduce and demonstrate coherent time stretch transformation; a technique that combines dispersive Fourier transform with optically broadband coherent detection.

  14. Abstract ID: 176 Geant4 implementation of inter-atomic interference effect in small-angle coherent X-ray scattering for materials of medical interest.

    Science.gov (United States)

    Paternò, Gianfranco; Cardarelli, Paolo; Contillo, Adriano; Gambaccini, Mauro; Taibi, Angelo

    2018-01-01

    Advanced applications of digital mammography such as dual-energy and tomosynthesis require multiple exposures and thus deliver higher dose compared to standard mammograms. A straightforward manner to reduce patient dose without affecting image quality would be removal of the anti-scatter grid, provided that the involved reconstruction algorithms are able to take the scatter figure into account [1]. Monte Carlo simulations are very well suited for the calculation of X-ray scatter distribution and can be used to integrate such information within the reconstruction software. Geant4 is an open source C++ particle tracking code widely used in several physical fields, including medical physics [2,3]. However, the coherent scattering cross section used by the standard Geant4 code does not take into account the influence of molecular interference. According to the independent atomic scattering approximation (the so-called free-atom model), coherent radiation is indistinguishable from primary radiation because its angular distribution is peaked in the forward direction. Since interference effects occur between x-rays scattered by neighbouring atoms in matter, it was shown experimentally that the scatter distribution is affected by the molecular structure of the target, even in amorphous materials. The most important consequence is that the coherent scatter distribution is not peaked in the forward direction, and the position of the maximum is strongly material-dependent [4]. In this contribution, we present the implementation of a method to take into account inter-atomic interference in small-angle coherent scattering in Geant4, including a dedicated data set of suitable molecular form factor values for several materials of clinical interest. Furthermore, we present scatter images of simple geometric phantoms in which the Rayleigh contribution is rigorously evaluated. Copyright © 2017.

  15. A journal cancellation survey and resulting impact on interlibrary loan.

    Science.gov (United States)

    Nash, Jacob L; McElfresh, Karen R

    2016-10-01

    The research describes an extensible method of evaluating and cancelling electronic journals during a budget shortfall and evaluates implications for interlibrary loan (ILL) and user satisfaction. We calculated cost per use for cancellable electronic journal subscriptions (n=533) from the 2013 calendar year and the first half of 2014, cancelling titles with cost per use greater than $20 and less than 100 yearly uses. For remaining titles, we issued an online survey asking respondents to rank the importance of journals to their work. Finally, we gathered ILL requests and COUNTER JR2 turnaway reports for calendar year 2015. Three hundred fifty-four respondents completed the survey. Because of the level of heterogeneity of titles in the survey as well as respondents' backgrounds, most titles were reported to be never used. We developed criteria based on average response across journals to determine which to cancel. Based on this methodology, we cancelled eight journals. Examination of ILL data revealed that none of the cancelled titles were requested with any frequency. Free-text responses indicated, however, that many value free ILL as a suitable substitute for immediate full-text access to biomedical journal literature. Soliciting user feedback through an electronic survey can assist collections librarians to make electronic journal cancellation decisions during slim budgetary years. This methodology can be adapted and improved upon at other health sciences libraries.

  16. Effects of Sleep Deprivation on Phase Synchronization as Assessed by Wavelet Phase Coherence Analysis of Prefrontal Tissue Oxyhemoglobin Signals.

    Science.gov (United States)

    Bu, Lingguo; Zhang, Ming; Li, Jianfeng; Li, Fangyi; Liu, Heshan; Li, Zengyong

    2017-01-01

    To reveal the physiological mechanism of the decline in cognitive function after sleep deprivation, a within-subject study was performed to assess sleep deprivation effects on phase synchronization, as revealed by wavelet phase coherence (WPCO) analysis of prefrontal tissue oxyhemoglobin signals. Twenty subjects (10 male and 10 female, 25.5 ± 3.5 years old) were recruited to participate in two tests: one without sleep deprivation (group A) and the other with 24 h of sleep deprivation (group B). Before the test, each subject underwent a subjective evaluation using visual analog scales. A cognitive task was performed by judging three random numbers. Continuous recordings of the near-infrared spectroscopy (NIRS) signals were obtained from both the left and right prefrontal lobes during rest, task, and post-task periods. The WPCO of cerebral Delta [HbO2] signals were analyzed for these three periods for both groups A and B. Six frequency intervals were defined: I: 0.6-2 Hz (cardiac activity), II: 0.145-0.6 Hz (respiratory activity), III: 0.052-0.145 Hz (myogenic activity), IV: 0.021-0.052 Hz (neurogenic activity), V: 0.0095-0.021 Hz (nitric oxide related endothelial activity) and VI: 0.005-0.0095 Hz (non-nitric oxide related endothelial activity). WPCO in intervals III (F = 5.955, p = 0.02) and V (F = 4.7, p = 0.037) was significantly lower in group B than in group A at rest. During the task period, WPCO in intervals III (F = 5.175, p = 0.029) and IV (F = 4.585, p = 0.039) was significantly lower in group B compared with group A. In the post-task recovery period, the WPCO in interval III (F = 6.125, p = 0.02) was significantly lower in group B compared with group A. Reaction time was significantly prolonged, and the accuracy rate and F1 score both declined after sleep deprivation. The decline in WPCO after sleep deprivation indicates reduced phase synchronization between left and right prefrontal oxyhemoglobin oscillations, which may contribute to the diminished

  17. Ground clutter cancellation in incoherent radars: solutions for EISCAT Svalbard radar

    Directory of Open Access Journals (Sweden)

    T. Turunen

    2000-09-01

    Full Text Available Incoherent scatter radars measure ionosphere parameters using modified Thomson scatter from free electrons in the target (see e.g. Hagfors, 1997. The integrated cross section of the ionospheric scatterers is extremely small and the measurements can easily be disturbed by signals returned by unwanted targets. Ground clutter signals, entering via the antenna side lobes, can render measurements at the nearest target ranges totally impossible. The EISCAT Svalbard Radar (ESR, which started measurements in 1996, suffers from severe ground clutter and the ionosphere cannot be measured in any simple manner at ranges less than about 120–150 km, depending on the modulation employed. If the target and clutter signals have different, and clearly identifiable, properties then, in principle, there are always ways to eliminate the clutter. In incoherent scatter measurements, differences in the coherence times of the wanted and unwanted signals can be used for clutter cancellation. The clutter cancellation must be applied to all modulations, usually alternating codes in modern experiments, used for shorter ranges. Excellent results have been obtained at the ESR using a simple pulse-to-pulse clutter subtraction method, but there are also other possibilities.Key words: Radio science (ionospheric physics; signal processing; instruments and techniques

  18. Background Noise Reduction Using Adaptive Noise Cancellation Determined by the Cross-Correlation

    Science.gov (United States)

    Spalt, Taylor B.; Brooks, Thomas F.; Fuller, Christopher R.

    2012-01-01

    Background noise due to flow in wind tunnels contaminates desired data by decreasing the Signal-to-Noise Ratio. The use of Adaptive Noise Cancellation to remove background noise at measurement microphones is compromised when the reference sensor measures both background and desired noise. The technique proposed modifies the classical processing configuration based on the cross-correlation between the reference and primary microphone. Background noise attenuation is achieved using a cross-correlation sample width that encompasses only the background noise and a matched delay for the adaptive processing. A present limitation of the method is that a minimum time delay between the background noise and desired signal must exist in order for the correlated parts of the desired signal to be separated from the background noise in the crosscorrelation. A simulation yields primary signal recovery which can be predicted from the coherence of the background noise between the channels. Results are compared with two existing methods.

  19. Reaction mechanisms in coherent nuclear photoproduction

    International Nuclear Information System (INIS)

    Lazard, C.

    Nuclear coherent pion photoproduction is studied. Pion rescattering and propagation effects inside nucleus and mesic exchange current effects are discussed. Influence of nuclear wave functions and Fermi motion is presented [fr

  20. Design of Cancelable Palmprint Templates Based on Look Up Table

    Science.gov (United States)

    Qiu, Jian; Li, Hengjian; Dong, Jiwen

    2018-03-01

    A novel cancelable palmprint templates generation scheme is proposed in this paper. Firstly, the Gabor filter and chaotic matrix are used to extract palmprint features. It is then arranged into a row vector and divided into equal size blocks. These blocks are converted to corresponding decimals and mapped to look up tables, forming final cancelable palmprint features based on the selected check bits. Finally, collaborative representation based classification with regularized least square is used for classification. Experimental results on the Hong Kong PolyU Palmprint Database verify that the proposed cancelable templates can achieve very high performance and security levels. Meanwhile, it can also satisfy the needs of real-time applications.

  1. Crosstalk cancellation on linearly and circularly polarized communications satellite links

    Science.gov (United States)

    Overstreet, W. P.; Bostian, C. W.

    1979-01-01

    The paper discusses the cancellation network approach for reducing crosstalk caused by depolarization on a dual-polarized communications satellite link. If the characteristics of rain depolarization are sufficiently well known, the cancellation network can be designed in a way that reduces system complexity, the most important parameter being the phase of the cross-polarized signal. Relevant theoretical calculations and experimental data are presented. The simplicity of the cancellation system proposed makes it ideal for use with small domestic or private earth terminals.

  2. Three-dimensional microarchitecture of adolescent cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Hvid, Ivan

    2012-01-01

    , the adolescent cancellous bone had similar bone volume fraction (BV/TV), structure type (plate, rod or mixtures), and connectivity (3-D trabecular networks) as the adult cancellous bone. The adolescent cancellous bone had significantly lower bone surface density (bone surface per total volume of specimen...... and lateral condyle. These samples were micro-CT scanned (vivaCT 40, Scanco Medical AG, Switzerland) resulting in cubic voxel sizes of 10.5⁎10.5⁎10.5μm(3). Microarchitectural properties were calculated. The samples were then tested in compression followed by collagen and mineral determination. Interestingly...

  3. Infrared divergence cancellation in pure Yang-Mills theory

    International Nuclear Information System (INIS)

    Alvarez, A.G.

    1977-01-01

    Virtual and real corrections to massless external lines in pure Yang-Mills theory are considered in order to look for general features of the infrared divergence cancellation. Use of the Ward identities and sums over transverse polarization states give rise to terms formally corresponding to real ghost emission, cancelling ghost loop singularities, and to a factorisation of the hard narrow single gauge boson emission. Other virtual corrections are examined in the soft region and a graph by graph cancellation is also found. An illustrative explicit calculation of scattering of a gauge particle in an external scalar potential, including hard narrow angle emission is presented. (Auth.)

  4. Cancellation of soft and collinear divergences in noncommutative QED

    International Nuclear Information System (INIS)

    Mirza, B.; Zarei, M.

    2006-01-01

    In this paper, we investigate the behavior of noncommutative IR divergences and will also discuss their cancellation in the physical cross sections. The commutative IR (soft) divergences existing in the nonplanar diagrams will be examined in order to prove an all-order cancellation of these divergences using the Weinberg's method. In noncommutative QED, collinear divergences due to triple photon splitting vertex, were encountered, which are shown to be canceled out by the noncommutative version of KLN theorem. This guarantees that there is no mixing between the Collinear, soft divergences and noncommutative IR divergences

  5. Journal cancellations in university libraries in South Africa

    Directory of Open Access Journals (Sweden)

    Ruth Hoskins

    2010-01-01

    Full Text Available This article is based on part of a survey that investigated journal cancellations in university libraries in South Africa. A study population consisting of 17 university libraries in South Africa was surveyed by means of an online questionnaire to establish the factors that influenced journal cancellations. Interpretation of the results revealed that South African university libraries, like most academic and research libraries world wide, have been adversely affected by high priced journal subscriptions and many libraries have simply cancelled subscriptions to pay for ongoing subscriptions. Recommendations are made about enhancing library budgets and access to usage statistics, supporting consortia and avoiding restrictive journal packages.

  6. Group study of an "undercover" test for visuospatial neglect: invisible cancellation can reveal more neglect than standard cancellation.

    Science.gov (United States)

    Wojciulik, E; Rorden, C; Clarke, K; Husain, M; Driver, J

    2004-09-01

    Visual neglect is a relatively common deficit after brain damage, particularly strokes. Cancellation tests provide standard clinical measures of neglect severity and deficits in daily life. A recent single-case study introduced a new variation on standard cancellation. Instead of making a visible mark on each target found, the patient made invisible marks (recorded with carbon paper underneath, for later scoring). Such invisible cancellation was found to reveal more neglect than cancellation with visible marks. Here we test the generality of this. Twenty three successive cases with suspected neglect each performed cancellation with visible or invisible marks. Neglect of contralesional targets was more pronounced with invisible marks. Indeed, about half of the patients only showed neglect in this version. For cases showing more neglect with invisible marks, stronger neglect of contralesional targets correlated with more revisits to ipsilesional targets for making additional invisible marks upon them. These results indicate that cancellation with invisible marks can reveal more neglect than standard cancellation with visible marks, while still providing a practical bedside test. Our observations may be consistent with recent proposals that demands on spatial working memory (required to keep track of previously found items only when marked invisibly) can exacerbate spatial neglect.

  7. Multiple soliton self-frequency shift cancellations in a temporally tailored photonic crystal fiber

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lai; Kang, Zhe; Li, Qing; Gao, Xuejian; Qin, Guanshi, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn; Qin, Weiping, E-mail: qings@jlu.edu.cn, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Liao, Meisong; Hu, Lili [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Ohishi, Yasutake [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2014-11-03

    We report the generation of multiple soliton self-frequency shift cancellations in a temporally tailored tellurite photonic crystal fiber (PCF). The temporally regulated group velocity dispersion (GVD) is generated in the fiber by soliton induced optical Kerr effect. Two red-shifted dispersive waves spring up when two Raman solitons meet their own second zero-dispersion-wavelengths in the PCF. These results show how, through temporally tailored GVD, nonlinearities can be harnessed to generate unexpected effects.

  8. Electromagnetic spatial coherence wavelets

    International Nuclear Information System (INIS)

    Castaneda, R.; Garcia-Sucerquia, J.

    2005-10-01

    The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)

  9. 30 CFR 280.27 - When may MMS cancel my permit?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may MMS cancel my permit? 280.27 Section... Part Interrupted Activities § 280.27 When may MMS cancel my permit? The RD may cancel a permit at any time. (a) If we cancel your permit, the RD will advise you by certified or registered mail 30 days...

  10. 30 CFR 285.437 - When can my lease or grant be canceled?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When can my lease or grant be canceled? 285.437... Administration Lease Or Grant Cancellation § 285.437 When can my lease or grant be canceled? (a) The Secretary will cancel any lease or grant issued under this part upon proof that it was obtained by fraud or...

  11. 21 CFR 1.235 - How and when do you cancel your facility's registration information?

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false How and when do you cancel your facility's... for Registration of Food Facilities § 1.235 How and when do you cancel your facility's registration information? (a) Notification of registration cancellation. A facility canceling its registration must do so...

  12. 49 CFR 40.267 - What problems always cause an alcohol test to be cancelled?

    Science.gov (United States)

    2010-10-01

    ... cancelled? 40.267 Section 40.267 Transportation Office of the Secretary of Transportation PROCEDURES FOR... always cause an alcohol test to be cancelled? As an employer, a BAT, or an STT, you must cancel an... the test was cancelled and must be treated as if the test never occurred. These problems are: (a) In...

  13. 30 CFR 250.182 - When may the Secretary cancel a lease at the exploration stage?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may the Secretary cancel a lease at the... Requirements, Lease Term Extensions, and Lease Cancellations § 250.182 When may the Secretary cancel a lease at... be modified to avoid the condition(s). The Secretary may cancel the lease if: (a) The primary lease...

  14. Cancell/Cantron/Protocel (PDQ®)—Health Professional Version

    Science.gov (United States)

    Expert-reviewed information summary about the use of Cancell/Cantron/Protocel as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  15. 78 FR 40138 - Chlorpyrifos; Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-07-03

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2005-0057; FRL-9389-6] Chlorpyrifos; Cancellation... and accepted by the Agency, of products containing chlorpyrifos, pursuant to the Federal Insecticide... 40139

  16. Vacuum Energy Cancellation in a Non-supersymmetric String

    International Nuclear Information System (INIS)

    Kachru, Shamit; Kumar, Jason; Silverstein, Eva

    1998-01-01

    We present a nonsupersymmetric orbifold of type II string theory and show that it has vanishing cosmological constant at the one and two loop level. We argue heuristically that the cancellation may persist at higher loops

  17. Vacuum energy cancellation in a non-supersymmetric string

    Energy Technology Data Exchange (ETDEWEB)

    Kachru, S. [Univ. of California, Berkeley, CA (US). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (US); Kumar, J.; Silverstein, E. [Stanford Univ., CA (US)

    1998-08-01

    The authors present a nonsupersymmetric orbifold of type 2 string theory and show that it has vanishing cosmological constant at the one and two loop level. They argue heuristically that the cancellation persists at higher loops.

  18. MAGNETIC FLUX CANCELLATION IN ELLERMAN BOMBS

    Energy Technology Data Exchange (ETDEWEB)

    Reid, A.; Mathioudakis, M.; Nelson, C. J.; Henriques, V. [Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, BT7 1NN, Northern Ireland (United Kingdom); Doyle, J. G. [Armagh Observatory, College Hill, Armagh, BT61 9DG (United Kingdom); Scullion, E. [Trinity College Dublin, College Green, Dublin 2 (Ireland); Ray, T., E-mail: areid29@qub.ac.uk [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2016-06-01

    Ellerman Bombs (EBs) are often found to be co-spatial with bipolar photospheric magnetic fields. We use H α imaging spectroscopy along with Fe i 6302.5 Å spectropolarimetry from the Swedish 1 m Solar Telescope (SST), combined with data from the Solar Dynamic Observatory , to study EBs and the evolution of the local magnetic fields at EB locations. EBs are found via an EB detection and tracking algorithm. Using NICOLE inversions of the spectropolarimetric data, we find that, on average, (3.43 ± 0.49) × 10{sup 24} erg of stored magnetic energy disappears from the bipolar region during EB burning. The inversions also show flux cancellation rates of 10{sup 14}–10{sup 15} Mx s{sup −1} and temperature enhancements of 200 K at the detection footpoints. We investigate the near-simultaneous flaring of EBs due to co-temporal flux emergence from a sunspot, which shows a decrease in transverse velocity when interacting with an existing, stationary area of opposite polarity magnetic flux, resulting in the formation of the EBs. We also show that these EBs can be fueled further by additional, faster moving, negative magnetic flux regions.

  19. The effect of coherent phase control in (e, 2e) process of a hydrogenic ion in presence of a two colour laser field

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, C; Chattopadhyay, A; Deb, S Ghosh, E-mail: chand_sin@hotmail.co, E-mail: arpita.chattopadhyay@gmail.co, E-mail: srabanti.ghosh@gmail.co [Theoretical Physics Department, Indian Association for the Cultivation of Science, Kolkata - 700032 (India)

    2009-11-01

    We study the coherent phase control (CPC) of ionization (TDCS) of a hydrogenic ion under the action of a bichromatic laser field consisting of a fundamental frequency and one of its harmonics by varying the phase difference between the two components. A significant reduction is noted particularly in the recoil peak (dominant for the ionic target) with the two color field as compared to the monochromatic one, while the modification of the binary peak is comparatively less. The CPC is found to be more effective for the odd harmonics than the even one.

  20. Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states

    International Nuclear Information System (INIS)

    Yuan Hong-Chun; Xiao Jin; Xiong Chao; Zhu Xi-Fang; Xu Xue-Xiang

    2016-01-01

    We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilation-then-creation (AC) and creation-then-annihilation (CA) on the coherent state, respectively, such as higher-order sub-Poissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m . By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. (paper)

  1. Coherent Coupled Qubits for Quantum Annealing

    Science.gov (United States)

    Weber, Steven J.; Samach, Gabriel O.; Hover, David; Gustavsson, Simon; Kim, David K.; Melville, Alexander; Rosenberg, Danna; Sears, Adam P.; Yan, Fei; Yoder, Jonilyn L.; Oliver, William D.; Kerman, Andrew J.

    2017-07-01

    Quantum annealing is an optimization technique which potentially leverages quantum tunneling to enhance computational performance. Existing quantum annealers use superconducting flux qubits with short coherence times limited primarily by the use of large persistent currents Ip. Here, we examine an alternative approach using qubits with smaller Ip and longer coherence times. We demonstrate tunable coupling, a basic building block for quantum annealing, between two flux qubits with small (approximately 50-nA) persistent currents. Furthermore, we characterize qubit coherence as a function of coupler setting and investigate the effect of flux noise in the coupler loop on qubit coherence. Our results provide insight into the available design space for next-generation quantum annealers with improved coherence.

  2. Task-related modulation of visual neglect in cancellation tasks

    OpenAIRE

    Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Driver, Jon

    2008-01-01

    Unilateral neglect involves deficits of spatial exploration and awareness that do not always affect a fixed portion of extrapersonal space, but may vary with current stimulation and possibly with task demands. Here, we assessed any ‘top-down’, task-related influences on visual neglect, with novel experimental variants of the cancellation test. Many different versions of the cancellation test are used clinically, and can differ in the extent of neglect revealed, though the exact factors determ...

  3. An inductorless wideband LNA with a new noise canceling technique

    OpenAIRE

    MOGHADAM, POURIA PAZHOUHESH; ABRISHAMIFAR, ADIB

    2017-01-01

    An inductorless wideband low-noise amplifier (LNA) employing a new noise canceling technique for multistandard applications is presented. The main amplifier has a cascode common gate structure, which provides good input impedance matching and isolation. The proposed noise canceling technique not only improves the noise figure and power gain but also embeds a g$_{m}$-boosting technique in itself, which reduces the power consumption of the main amplifier. Using current-steering and ...

  4. Noise cancellation properties of displacement noise free interferometer

    International Nuclear Information System (INIS)

    Sato, Shuichi; Kawamura, Seiji; Nishizawa, Atsushi; Chen Yanbei

    2010-01-01

    We have demonstrated the practical feasibility of a displacement- and frequency-noise-free laser interferometer (DFI) by partially implementing a recently proposed optical configuration using bi-directional Mach-Zehnder interferometers (MZIs). The noise cancellation efficiency was evaluated by comparing the displacement noise spectrum of the MZIs and the DFI, demonstrating up to 50 dB of noise cancellation. In addition, the possible extension of DFI as QND device is explored.

  5. Active noise control in a duct to cancel broadband noise

    Science.gov (United States)

    Chen, Kuan-Chun; Chang, Cheng-Yuan; Kuo, Sen M.

    2017-09-01

    The paper presents cancelling duct noises by using the active noise control (ANC) techniques. We use the single channel feed forward algorithm with feedback neutralization to realize ANC. Several kinds of ducts noises including tonal noises, sweep tonal signals, and white noise had investigated. Experimental results show that the proposed ANC system can cancel these noises in a PVC duct very well. The noise reduction of white noise can be up to 20 dB.

  6. On a possible mechanism of cosmological term cancellation

    International Nuclear Information System (INIS)

    Dolgov, A.D.

    1982-01-01

    A model is proposed in which cosmological constant is cancelled automatically because of the back reaction on it of a scalar field PHI. The cancellation takes place if two conditions are imposed on the theory, namely vanishing of mass selfinteraction of field PHI. The vacuum energy in the framework of the model considered does not dissapear completely. This leads to some modification of the standard universe expansion scheme

  7. Adaptive cancellation of motion artifact in wearable biosensors.

    Science.gov (United States)

    Yousefi, Rasoul; Nourani, Mehrdad; Panahi, Issa

    2012-01-01

    The performance of wearable biosensors is highly influenced by motion artifact. In this paper, a model is proposed for analysis of motion artifact in wearable photoplethysmography (PPG) sensors. Using this model, we proposed a robust real-time technique to estimate fundamental frequency and generate a noise reference signal. A Least Mean Square (LMS) adaptive noise canceler is then designed and validated using our synthetic noise generator. The analysis and results on proposed technique for noise cancellation shows promising performance.

  8. Multimodal biometric approach for cancelable face template generation

    Science.gov (United States)

    Paul, Padma Polash; Gavrilova, Marina

    2012-06-01

    Due to the rapid growth of biometric technology, template protection becomes crucial to secure integrity of the biometric security system and prevent unauthorized access. Cancelable biometrics is emerging as one of the best solutions to secure the biometric identification and verification system. We present a novel technique for robust cancelable template generation algorithm that takes advantage of the multimodal biometric using feature level fusion. Feature level fusion of different facial features is applied to generate the cancelable template. A proposed algorithm based on the multi-fold random projection and fuzzy communication scheme is used for this purpose. In cancelable template generation, one of the main difficulties is keeping interclass variance of the feature. We have found that interclass variations of the features that are lost during multi fold random projection can be recovered using fusion of different feature subsets and projecting in a new feature domain. Applying the multimodal technique in feature level, we enhance the interclass variability hence improving the performance of the system. We have tested the system for classifier fusion for different feature subset and different cancelable template fusion. Experiments have shown that cancelable template improves the performance of the biometric system compared with the original template.

  9. Combination of Adaptive Feedback Cancellation and Binaural Adaptive Filtering in Hearing Aids

    Directory of Open Access Journals (Sweden)

    Anthony Lombard

    2009-01-01

    Full Text Available We study a system combining adaptive feedback cancellation and adaptive filtering connecting inputs from both ears for signal enhancement in hearing aids. For the first time, such a binaural system is analyzed in terms of system stability, convergence of the algorithms, and possible interaction effects. As major outcomes of this study, a new stability condition adapted to the considered binaural scenario is presented, some already existing and commonly used feedback cancellation performance measures for the unilateral case are adapted to the binaural case, and possible interaction effects between the algorithms are identified. For illustration purposes, a blind source separation algorithm has been chosen as an example for adaptive binaural spatial filtering. Experimental results for binaural hearing aids confirm the theoretical findings and the validity of the new measures.

  10. Text Coherence in Translation

    Science.gov (United States)

    Zheng, Yanping

    2009-01-01

    In the thesis a coherent text is defined as a continuity of senses of the outcome of combining concepts and relations into a network composed of knowledge space centered around main topics. And the author maintains that in order to obtain the coherence of a target language text from a source text during the process of translation, a translator can…

  11. Coherent Multistatic ISAR Imaging

    NARCIS (Netherlands)

    Dorp, Ph. van; Otten, M.P.G.; Verzeilberg, J.M.M.

    2012-01-01

    This paper presents methods for Coherent Multistatic Radar Imaging for Non Cooperative Target Recognition (NCTR) with a network of radar sensors. Coherent Multistatic Radar Imaging is based on an extension of existing monostatic ISAR algorithms to the multistatic environment. The paper describes the

  12. VCSEL Based Coherent PONs

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Rodes, Roberto; Caballero Jambrina, Antonio

    2014-01-01

    We present a review of research performed in the area of coherent access technologies employing vertical cavity surface emitting lasers (VCSELs). Experimental demonstrations of optical transmission over a passive fiber link with coherent detection using VCSEL local oscillators and directly modula...

  13. Scalable coherent interface

    International Nuclear Information System (INIS)

    Alnaes, K.; Kristiansen, E.H.; Gustavson, D.B.; James, D.V.

    1990-01-01

    The Scalable Coherent Interface (IEEE P1596) is establishing an interface standard for very high performance multiprocessors, supporting a cache-coherent-memory model scalable to systems with up to 64K nodes. This Scalable Coherent Interface (SCI) will supply a peak bandwidth per node of 1 GigaByte/second. The SCI standard should facilitate assembly of processor, memory, I/O and bus bridge cards from multiple vendors into massively parallel systems with throughput far above what is possible today. The SCI standard encompasses two levels of interface, a physical level and a logical level. The physical level specifies electrical, mechanical and thermal characteristics of connectors and cards that meet the standard. The logical level describes the address space, data transfer protocols, cache coherence mechanisms, synchronization primitives and error recovery. In this paper we address logical level issues such as packet formats, packet transmission, transaction handshake, flow control, and cache coherence. 11 refs., 10 figs

  14. Spatial coherence resonance and spatial pattern transition induced by the decrease of inhibitory effect in a neuronal network

    Science.gov (United States)

    Tao, Ye; Gu, Huaguang; Ding, Xueli

    2017-10-01

    Spiral waves were observed in the biological experiment on rat brain cortex with the application of carbachol and bicuculline which can block inhibitory coupling from interneurons to pyramidal neurons. To simulate the experimental spiral waves, a two-dimensional neuronal network composed of pyramidal neurons and inhibitory interneurons was built. By decreasing the percentage of active inhibitory interneurons, the random-like spatial patterns change to spiral waves and to random-like spatial patterns or nearly synchronous behaviors. The spiral waves appear at a low percentage of inhibitory interneurons, which matches the experimental condition that inhibitory couplings of the interneurons were blocked. The spiral waves exhibit a higher order or signal-to-noise ratio (SNR) characterized by spatial structure function than both random-like spatial patterns and nearly synchronous behaviors, which shows that changes of the percentage of active inhibitory interneurons can induce spatial coherence resonance-like behaviors. In addition, the relationship between the coherence degree and the spatial structures of the spiral waves is identified. The results not only present a possible and reasonable interpretation to the spiral waves observed in the biological experiment on the brain cortex with disinhibition, but also reveal that the spiral waves exhibit more ordered degree in spatial patterns.

  15. Measuring coherence with entanglement concurrence

    Science.gov (United States)

    Qi, Xianfei; Gao, Ting; Yan, Fengli

    2017-07-01

    Quantum coherence is a fundamental manifestation of the quantum superposition principle. Recently, Baumgratz et al (2014 Phys. Rev. Lett. 113 140401) presented a rigorous framework to quantify coherence from the view of theory of physical resource. Here we propose a new valid quantum coherence measure which is a convex roof measure, for a quantum system of arbitrary dimension, essentially using the generalized Gell-Mann matrices. Rigorous proof shows that the proposed coherence measure, coherence concurrence, fulfills all the requirements dictated by the resource theory of quantum coherence measures. Moreover, strong links between the resource frameworks of coherence concurrence and entanglement concurrence is derived, which shows that any degree of coherence with respect to some reference basis can be converted to entanglement via incoherent operations. Our work provides a clear quantitative and operational connection between coherence and entanglement based on two kinds of concurrence. This new coherence measure, coherence concurrence, may also be beneficial to the study of quantum coherence.

  16. Wavelength and coherence effects on the growth mechanism of silicon nanopillars and their use in the modification of spontaneous lifetime emission of BODIPY dye molecules

    Energy Technology Data Exchange (ETDEWEB)

    Acikgoz, Sabriye [Bogazici University, Department of Physics, Istanbul (Turkey); Karamanoglu Mehmetbey University, Department of Material Science and Engineering, Karaman (Turkey); Bilen, Bukem; Saygili, Asli C.; Aktas, Gulen; Inci, Mehmet Naci [Bogazici University, Department of Physics, Istanbul (Turkey); Sanyal, Amitav [Bogazici University, Department of Chemistry, Istanbul (Turkey)

    2012-09-15

    Silicon nanopillars are grown by an electrochemical anodization of p-type silicon wafers at low current densities in a hydrofluoric acid solution. CW, white light, and various UV pulsed lasers are employed as illumination sources in sample preparation to study wavelength and coherence effects on the growth mechanism of the nanopillars. Coherence is observed to be the foundation of regularity in obtaining conical shapes. The pillar size is found to be almost linearly proportional to the employed illumination wavelength during their growth. BODIPY dye molecules are chemically attached to these silicon nanopillars and the radiative decay rates are investigated by means of a time-resolved fluorescence experiment. The decay rate of the dye molecules embedded in the vicinity of various size pillar tips is significantly affected due to different apex angles of the conical nature. It is demonstrated that the pillar size and the separation between pillars can be adjusted if one uses a coherent light source with an appropriate wavelength during the course of fabrication process. Since change in the decay rate is due to tips of the pillars only, separation of a few micrometers between pillar tips allows one to directly monitor a dye, which is embedded to the tip of a single nanopillar, via a confocal microscopic method for the spontaneous lifetime measurements, without having needed to any extra efforts for an in situ imaging process. It is observed that as the pillar size gets smaller, the inhibition in the spontaneous lifetime of BODIPY is more pronounced. In addition, a more regular pillar structure yields nonvarying decay rates of the dye molecules throughout the silicon sample. (orig.)

  17. Coherent control and storage of a microwave pulse in a one-dimensional array of artificial atoms using the Autler-Townes effect and electromagnetically induced transparency

    Science.gov (United States)

    Ayaz, M. Q.; Waqas, Mohsin; Qamar, Sajid; Qamar, Shahid

    2018-02-01

    In this paper we propose a scheme for coherent control and storage of a microwave pulse in superconducting circuits exploiting the idea of electromagnetically induced transparency (EIT) and the Aulter-Townes (AT) effect. We show that superconducting artificial atoms in a four-level tripod configuration act as EIT based coherent microwave (μ w ) memories with gain features, when they are attached to a one-dimensional transmission line. These atoms are allowed to interact with three microwave fields, such that there are two control fields and one probe field. Our proposed system works in such a way that one control field with large Rabi frequency when interacting with atoms, produces the AT effect. While the second control field with relatively small Rabi frequency produces EIT in one of the absorption windows produced due to the AT splitting for the weak probe field. The group velocity of the probe pulse reduces significantly through this EIT window. Interestingly, the output intensity of the probe pulse increases as we increase the number of artificial atoms. Our results show that the probe microwave pulse can be stored and retrieved with high fidelity.

  18. Comparison of effects of Cyriax physiotherapy, a supervised exercise programme and polarized polychromatic non-coherent light (Bioptron light) for the treatment of lateral epicondylitis.

    Science.gov (United States)

    Stasinopoulos, Dimitrios; Stasinopoulos, Ioannis

    2006-01-01

    To compare the effectiveness of Cyriax physiotherapy, a supervised exercise programme, and polarized polychromatic non-coherent light (Bioptron light) in the treatment of lateral epicondylitis. Controlled clinical trial. Rheumatology and rehabilitation centre. This study was carried out with 75 patients who had lateral epicondylitis. They were allocated to three groups by sequential allocation. Group A (n = 25) was treated with Cyriax physiotherapy. A supervised exercise programme was given to group B (n = 25). Group C (n = 25) received polarized polychromatic non-coherent light (Bioptron light). All patients received three treatments per week for four weeks. Pain was evaluated using a visual analogue scale and function using a visual analogue scale and pain-free grip strength at the end of the four-week course of treatment (week 4), one month (week 8), three months (week 16) and six months (week 28) after the end of treatment. The supervised exercise programme produced the largest effect in the reduction of pain and in the improvement of function at the end of the treatment (PBioptron light) may be suitable.

  19. Critical Point Cancellation in 3D Vector Fields: Robustness and Discussion.

    Science.gov (United States)

    Skraba, Primoz; Rosen, Paul; Wang, Bei; Chen, Guoning; Bhatia, Harsh; Pascucci, Valerio

    2016-02-29

    Vector field topology has been successfully applied to represent the structure of steady vector fields. Critical points, one of the essential components of vector field topology, play an important role in describing the complexity of the extracted structure. Simplifying vector fields via critical point cancellation has practical merit for interpreting the behaviors of complex vector fields such as turbulence. However, there is no effective technique that allows direct cancellation of critical points in 3D. This work fills this gap and introduces the first framework to directly cancel pairs or groups of 3D critical points in a hierarchical manner with a guaranteed minimum amount of perturbation based on their robustness, a quantitative measure of their stability. In addition, our framework does not require the extraction of the entire 3D topology, which contains non-trivial separation structures, and thus is computationally effective. Furthermore, our algorithm can remove critical points in any subregion of the domain whose degree is zero and handle complex boundary configurations, making it capable of addressing challenging scenarios that may not be resolved otherwise. We apply our method to synthetic and simulation datasets to demonstrate its effectiveness.

  20. Evidence for color coherence in jet events

    Energy Technology Data Exchange (ETDEWEB)

    CDF Collaboration

    1994-06-01

    Color coherence effects in p{bar p} collisions are observed and studied with CDF, the Collider Detector at the Fermilab Tevatron collider. We demonstrate these effects by measuring spatial correlations between soft and leading jets in multi jet events. Variables sensitive to interference are identified by comparing the data to the predictions of various shower Monte Carlos that are substantially different with respect to the implementation of coherence.

  1. Performance Limitations Analysis of Imperfect Attenuators for Adaptive Self-Interference Cancellation System

    Directory of Open Access Journals (Sweden)

    J. Liu

    2016-09-01

    Full Text Available Radio frequency (RF adaptive self-interference cancellation system (RFAICS is extensively used to suppress the self-interference of radios operating in the same platform, such as military command vehicles, airplanes and navy vessels. RFAICS is generally consisted of couplers, attenuators, delay units, amplifiers, and filters and so on. However, RFAICS usually suffers severely from the imperfect attenuators. This paper firstly explores the RFAICS operation process in theory, and then thoroughly investigates and analyzes the negative effects of non-ideal attenuators on performance of RFAICS. The closed-form expressions fully describing the influences of attenuation bias and response-time respectively on the interference cancellation ratio (ICR and system convergence time (SCT are developed with this aim. Simulations are provided for the validity of the limitation analysis and obtained expressions. Results of simulations are in agreement with theoretical analysis, which is significant for component configuration in taking RFAICS into practice.

  2. Hawking radiation via anomaly cancellation for the black holes of five-dimensional minimal gauged supergravity

    International Nuclear Information System (INIS)

    Porfyriadis, Achilleas P.

    2009-01-01

    The anomaly cancellation method proposed by Wilczek et al. is applied to the general charged rotating black holes in five-dimensional minimal gauged supergravity. Thus Hawking temperature and fluxes are found. The Hawking temperature obtained agrees with the surface gravity formula. The black holes have charge and two unequal angular momenta, and these give rise to appropriate terms in the effective U(1) gauge field of the reduced (1+1)-dimensional theory. In particular, it is found that the terms in this U(1) gauge field correspond exactly to the correct electrostatic potential and the two angular velocities on the horizon of the black holes, and so the results for the Hawking fluxes derived here from the anomaly cancellation method are in complete agreement with the ones obtained from integrating the Planck distribution.

  3. A single antenna interference cancellation and adaptive technique based on ALOE

    Directory of Open Access Journals (Sweden)

    Xu Han

    2017-02-01

    Full Text Available A new type of single antenna interference cancellation (SAIC algorithm based on ALOE filtering module is introduced for co-channel interference cancellation in GSM/GPRS/EDGE downlink without changing the link structure of traditional receiver.Meanwhile,an adjacent frequency adaptive detection based on power spectrum estimation method is introduced to solve adjacent frequency interference and complex interference.Compared with traditional energy noise estimation method,the new method has simpler structure,less complexity,and can effectively improve the adaptability for various scenarios.The simulation results show that it can raise the resistance to co-channel frequency interference and adjacent frequency interference in multimode chips with low complexity,which improves the quality of 2G voice communication.

  4. Reasons for Cancellation of Cases on the Day of Surgery-A Prospective Study

    Directory of Open Access Journals (Sweden)

    Rakesh Garg

    2009-01-01

    We believe that many of the on-the-day surgery cancellations of elective surgery were potentially avoidable. We observed that cancellations due to lack of theatre time were not only a scheduling problem but were mainly caused by surgeons underestimating the timeneeded for the operation. The requirement of the instruments necessary for scheduled surgical listshould be discussed a day prior to planned OR list and arranged. The non-availability of the surgeon should be informed in time so that another case is substituted in that slot. All patients who have met PACU discharge criteria must be discharged promptly to prevent delay in shifting out of the operated patient. Day care patients should be counseled adequately to report on time. Computerized scheduling should be utilized to create a realistic elective schedule. Audit should be carried out at regular intervals to find out the effective functioning of the operation theatre.

  5. A Microwave Photonic Interference Canceller: Architectures, Systems, and Integration

    Science.gov (United States)

    Chang, Matthew P.

    This thesis is a comprehensive portfolio of work on a Microwave Photonic Self-Interference Canceller (MPC), a specialized optical system designed to eliminate interference from radio-frequency (RF) receivers. The novelty and value of the microwave photonic system lies in its ability to operate over bandwidths and frequencies that are orders of magnitude larger than what is possible using existing RF technology. The work begins, in 2012, with a discrete fiber-optic microwave photonic canceller, which prior work had demonstrated as a proof-of-concept, and culminates, in 2017, with the first ever monolithically integrated microwave photonic canceller. With an eye towards practical implementation, the thesis establishes novelty through three major project thrusts. (Fig. 1): (1) Extensive RF and system analysis to develop a full understanding of how, and through what mechanisms, MPCs affect an RF receiver. The first investigations of how a microwave photonic canceller performs in an actual wireless environment and a digital radio are also presented. (2) New architectures to improve the performance and functionality of MPCs, based on the analysis performed in Thrust 1. A novel balanced microwave photonic canceller architecture is developed and experimentally demonstrated. The balanced architecture shows significant improvements in link gain, noise figure, and dynamic range. Its main advantage is its ability to suppress common-mode noise and reduce noise figure by increasing the optical power. (3) Monolithic integration of the microwave photonic canceller into a photonic integrated circuit. This thrust presents the progression of integrating individual discrete devices into their semiconductor equivalent, as well as a full functional and RF analysis of the first ever integrated microwave photonic canceller.

  6. Vibronic effects and destruction of exciton coherence in optical spectra of J-aggregates: A variational polaron transformation approach

    Energy Technology Data Exchange (ETDEWEB)

    Bloemsma, E.A.; Silvis, M.H.; Stradomska, A.; Knoester, J., E-mail: j.knoester@rug.nl

    2016-12-20

    Using a symmetry adapted polaron transformation of the Holstein Hamiltonian, we study the interplay of electronic excitation-vibration couplings, resonance excitation transfer interactions, and temperature in the linear absorption spectra of molecular J-aggregates. Semi-analytical expressions for the spectra are derived and compared with results obtained from direct numerical diagonalization of the Hamiltonian in the two-particle basis set representation. At zero temperature, we show that our polaron transformation reproduces both the collective (exciton) and single-molecule (vibrational) optical response associated with the appropriate standard perturbation limits. Specifically, for the molecular dimer excellent agreement with the spectra from the two-particle approach for the entire range of model parameters is obtained. This is in marked contrast to commonly used polaron transformations. Upon increasing the temperature, the spectra show a transition from the collective to the individual molecular features, which results from the thermal destruction of the exciton coherence.

  7. Coherence Phenomena in Coupled Optical Resonators

    Science.gov (United States)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  8. Spectral domain optical coherence tomography as an effective screening test for hydroxychloroquine retinopathy (the “flying saucer” sign

    Directory of Open Access Journals (Sweden)

    Eric Chen

    2010-10-01

    Full Text Available Eric Chen, David M Brown, Matthew S Benz, Richard H Fish, Tien P Wong, Rosa Y Kim, James C MajorRetina Consultants of Houston, The Methodist Hospital, Houston, Texas, USAPurpose: While the long-term incidence of hydroxychloroquine (HCQ retinopathy is low, there remains no definitive clinical screening test to recognize HCQ toxicity before ophthalmoscopic fundus changes or visual symptoms. Patients receiving HCQ were evaluated with spectral domain optical coherence tomography (SD OCT to assess the feasibility of identifying HCQ retinopathy at an early stage.Methods: Twenty-five patients referred for the evaluation of hydroxychloroquine toxicity underwent a comprehensive ocular examination, Humphrey visual field (HVF perimetry, time domain OCT, and SD OCT. Some patients with screening abnormalities also underwent further diagnostic testing at the discretion of the treating providers.Results: Five patients were found to have SD OCT findings corresponding to HCQ toxicity and retinal damage as seen by clinical exam and/or HVF perimetry. Two patients with advanced toxicity were found to have significant outer retina disruption in the macula on SD OCT. Three patients with early HCQ toxicity and HVF 10-2 perifoveal defects were found to have loss of the perifoveal photoreceptor inner segment/outer segment (IS/OS junction with intact outer retina directly under the fovea, creating the “flying saucer” sign. While two of these three patients had early ophthalmoscopic fundus changes, one had none.Conclusion: Outer retinal abnormalities including perifoveal photoreceptor IS/OS junction disruption can be identified by SD OCT in early HCQ toxicity, sometimes even before ophthalmoscopic fundus changes are apparent. SD OCT may have a potential complementary role in screening for HCQ retinopathy due to its quick acquisition and because it is more objective than automated perimetry.Keywords: drug toxicity, hydroxychloroquine, photoreceptors, screening test

  9. A Review on Successive Interference Cancellation-Based Optical PPM-CDMA Signaling

    Science.gov (United States)

    Alsowaidi, Naif; Eltaif, Tawfig; Mokhtar, Mohd Ridzuan

    2017-06-01

    This paper presents a comprehensive review of successive interference cancellation (SIC) scheme using pulse position modulation (PPM) for optical code division multiple access (OCDMA) systems. SIC scheme focuses on high-intensity signal, which will be selected after all users were detected, and then it will be subtracted from the overall received signal, hence, generating a new received signal. This process continues till all users eliminated one by one have been detected. It is shown that the random location of the sequences due to PPM encoding can reduce the probability of concentrated buildup of the pulse overlap in any one-slot time, and support SIC to easily remove the effect of the strongest signal at each stage of the cancellation process. The system bit error rate (BER) performance with modified quadratic congruence (MQC) codes used as signature sequence has been investigated. A detailed theoretical analysis of proposed system taking into account the impact of imperfect interference cancellation, the loss produced from the splitting during encoding and decoding, the channel loss and multiple access interference is presented. Results show that under average effective power constraint optical CDMA system using SIC scheme with M-ary PPM modulation outperforms conventional correlator detector and SIC scheme with on-off keying (OOK) modulation.

  10. Laser imprint reduction with a shaping pulse, oscillatory Richtmyer-Meshkov to Rayleigh-Taylor transition and other coherent effects in plastic-foam targets

    International Nuclear Information System (INIS)

    Metzler, N.; Velikovich, A.L.; Schmitt, A.J.; Karasik, M.; Serlin, V.; Mostovych, A.N.; Obenschain, S.P.; Gardner, J.H.; Aglitskiy, Y.

    2003-01-01

    A substantial reduction of the laser imprint with a short, low-energy 'shaping' laser pulse incident upon a foam-plastic sandwich target prior to the main laser pulse has been demonstrated to be possible [Metzler et al., Phys. Plasmas 9, 5050 (2002)]. Nonuniformity of this shaping pulse, however, produces standing sonic waves in the target. Laser-imprinted seeds for the Rayleigh-Taylor (RT) instability growth then emerge from the interaction of these waves with the strong shock wave launched by the drive laser pulse. Such coherent interaction between different waves and modes perturbed at the same wavelength is shown to be important in a variety of situations relevant to the inertial confinement fusion studies. As an example, an oscillatory transition from the classical Richtmyer-Meshkov shock-interface instability development to the RT growth exhibiting a characteristic phase reversal in a target of finite thickness is described. Another example refers to the feedout mechanism of seeding the perturbations that come from the nonuniformities of the rear (inner) surface of the laser target. The coherent interaction between the strong shock wave from the main laser pulse and the rippled rarefaction wave produced by a low-intensity foot of the pulse produces observable effects, such as an extra phase reversal compared to the case of no foot. Some of these predictions are shown to be consistent with our new experimental results obtained in the feedout geometry on the Nike laser facility [S. P. Obenschain et al. Phys. Plasmas 3, 2098 (1996)

  11. Simulation for noise cancellation using LMS adaptive filter

    Science.gov (United States)

    Lee, Jia-Haw; Ooi, Lu-Ean; Ko, Ying-Hao; Teoh, Choe-Yung

    2017-06-01

    In this paper, the fundamental algorithm of noise cancellation, Least Mean Square (LMS) algorithm is studied and enhanced with adaptive filter. The simulation of the noise cancellation using LMS adaptive filter algorithm is developed. The noise corrupted speech signal and the engine noise signal are used as inputs for LMS adaptive filter algorithm. The filtered signal is compared to the original noise-free speech signal in order to highlight the level of attenuation of the noise signal. The result shows that the noise signal is successfully canceled by the developed adaptive filter. The difference of the noise-free speech signal and filtered signal are calculated and the outcome implies that the filtered signal is approaching the noise-free speech signal upon the adaptive filtering. The frequency range of the successfully canceled noise by the LMS adaptive filter algorithm is determined by performing Fast Fourier Transform (FFT) on the signals. The LMS adaptive filter algorithm shows significant noise cancellation at lower frequency range.

  12. Wavelet-LMS algorithm-based echo cancellers

    Science.gov (United States)

    Seetharaman, Lalith K.; Rao, Sathyanarayana S.

    2002-12-01

    This paper presents Echo Cancellers based on the Wavelet-LMS Algorithm. The performance of the Least Mean Square Algorithm in Wavelet transform domain is observed and its application in Echo cancellation is analyzed. The Widrow-Hoff Least Mean Square Algorithm is most widely used algorithm for Adaptive filters that function as Echo Cancellers. The present day communication signals are widely non-stationary in nature and some errors crop up when Least Mean Square Algorithm is used for the Echo Cancellers handling such signals. The analysis of non-stationary signals often involves a compromise between how well transitions or discontinuities can be located. The multi-scale or multi-resolution of signal analysis, which is the essence of wavelet transform, makes Wavelets popular in non-stationary signal analysis. In this paper, we present a Wavelet-LMS algorithm wherein the wavelet coefficients of a signal are modified adaptively using the Least Mean Square Algorithm and then reconstructed to give an Echo-free signal. The Echo Canceller based on this Algorithm is found to have a better convergence and a comparatively lesser MSE (Mean Square error).

  13. Full-duplex wireless communications systems self-interference cancellation

    CERN Document Server

    Le-Ngoc, Tho

    2017-01-01

    This book introduces the development of self-interference (SI)-cancellation techniques for full-duplex wireless communication systems. The authors rely on estimation theory and signal processing to develop SI-cancellation algorithms by generating an estimate of the received SI and subtracting it from the received signal. The authors also cover two new SI-cancellation methods using the new concept of active signal injection (ASI) for full-duplex MIMO-OFDM systems. The ASI approach adds an appropriate cancelling signal to each transmitted signal such that the combined signals from transmit antennas attenuate the SI at the receive antennas. The authors illustrate that the SI-pre-cancelling signal does not affect the data-bearing signal. This book is for researchers and professionals working in wireless communications and engineers willing to understand the challenges of deploying full-duplex and practical solutions to implement a full-duplex system. Advanced-level students in electrical engineering and computer ...

  14. Intracoronary optical coherence tomography

    DEFF Research Database (Denmark)

    Tenekecioglu, Erhan; Albuquerque, Felipe N; Sotomi, Yohei

    2017-01-01

    By providing valuable information about the coronary artery wall and lumen, intravascular imaging may aid in optimizing interventional procedure results and thereby could improve clinical outcomes following percutaneous coronary intervention (PCI). Intravascular optical coherence tomography (OCT...

  15. Coherence in Industrial Transformation

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik; Lauridsen, Erik Hagelskjær

    2003-01-01

    The notion of coherence is used to illustrate the general finding, that the impact of environmental management systems and environmental policy is highly dependent of the context and interrelatedness of the systems, procedures and regimes established in society....

  16. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Fercher, A.F.; Andersen, Peter E.

    2017-01-01

    Optical coherence tomography (OCT) is a technique that is used to peer inside a body noninvasively. Tissue structure defined by tissue absorption and scattering coefficients, and the speed of blood flow, are derived from the characteristics of light remitted by the body. Singly backscattered light...... detected by partial coherence interferometry (PCI) is used to synthesize the tomographic image coded in false colors. A prerequisite of this technique is a low time-coherent but high space-coherent light source, for example, a superluminescent diode or a supercontinuum source. Alternatively, the imaging...... technique can be realized by using ultrafast wavelength scanning light sources. For tissue imaging, the light source wavelengths are restricted to the red and near-infrared (NIR) region from about 600 to 1300 nm, the so-called therapeutic window, where absorption (μa ≈ 0.01 mm−1) is small enough. Transverse...

  17. Coherent imaging at FLASH

    International Nuclear Information System (INIS)

    Chapman, H N; Bajt, S; Duesterer, S; Treusch, R; Barty, A; Benner, W H; Bogan, M J; Frank, M; Hau-Riege, S P; Woods, B W; Boutet, S; Cavalleri, A; Hajdu, J; Iwan, B; Seibert, M M; Timneanu, N; Marchesini, S; Sakdinawat, A; Sokolowski-Tinten, K

    2009-01-01

    We have carried out high-resolution single-pulse coherent diffractive imaging at the FLASH free-electron laser. The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. In particular we are developing imaging of biological specimens beyond conventional radiation damage resolution limits, developing imaging of ultrafast processes, and testing methods to characterize and perform single-particle imaging.

  18. Shot-noise-limited optical Faraday polarimetry with enhanced laser noise cancelling

    International Nuclear Information System (INIS)

    Li, Jiaming; Luo, Le; Carvell, Jeff; Cheng, Ruihua; Lai, Tianshu; Wang, Zixin

    2014-01-01

    We present a shot-noise-limited measurement of optical Faraday rotations with sub-ten-nanoradian angular sensitivity. This extremely high sensitivity is achieved by using electronic laser noise cancelling and phase sensitive detection. Specially, an electronic laser noise canceller with a common mode rejection ratio of over 100 dB was designed and built for enhanced laser noise cancelling. By measuring the Faraday rotation of ambient air, we demonstrate an angular sensitivity of up to 9.0×10 −9  rad/√(Hz), which is limited only by the shot-noise of the photocurrent of the detector. To date, this is the highest angular sensitivity ever reported for Faraday polarimeters in the absence of cavity enhancement. The measured Verdet constant of ambient air, 1.93(3)×10 −9 rad/(G cm) at 633 nm wavelength, agrees extremely well with the earlier experiments using high finesse optical cavities. Further, we demonstrate the applications of this sensitive technique in materials science by measuring the Faraday effect of an ultrathin iron film

  19. How soon is too soon? When to cancel a warning after a damaging tsunami

    Science.gov (United States)

    Fryer, G. J.; Becker, N. C.; Wang, D.; Weinstein, S.; Richards, K.

    2012-12-01

    following morning just as waves reflected from South America started to arrive (36 hours after the earthquake), and prudently chose to keep the bay closed for two further days. The Tohoku tsunami showed that resonances and trapped waves in shallow water can last for many hours and that energy reflected from distant shorelines can rejuvenate them. PTWC's real-time simulation of the tsunami, including animation of its propagation, now helps to identify which reflections will be most troublesome and should permit the Center to specify in advance how long a Warning should remain in effect. The current open-ended warnings, which specify when the tsunami will arrive but not how long the Warning should last, should be replaced with warnings active for a specified time ("until 3 a.m. tomorrow"), with PTWC adjusting the projected cancellation time based on coastal sea-level observations. Such warnings should greatly reduce public misconceptions and state and local government expectations about how long the hazard will last. The National Weather Service, parent agency of the US TWCs, already issues weather Warnings and Advisories active for specific durations, so this message format is already familiar to both the public and emergency managers.

  20. Suppression of the emittance growth induced by coherent synchrotron radiation in triple-bend achromats

    International Nuclear Information System (INIS)

    Huang Xiyang; Jiao Yi; Xu Gang; Cui Xiaohao

    2015-01-01

    The coherent synchrotron radiation (CSR) effect in a bending path plays an important role in transverse emittance dilution in high-brightness light sources and linear colliders, where the electron beams are of short bunch length and high peak current. Suppression of the emittance growth induced by CSR is critical to preserve the beam quality and help improve the machine performance. It has been shown that the CSR effect in a double-bend achromat (DBA) can be analyzed with the two-dimensional point-kick analysis method. In this paper, this method is applied to analyze the CSR effect in a triple-bend achromat (TBA) with symmetric layout, which is commonly used in the optics designs of energy recovery linacs (ERLs). A condition of cancelling the CSR linear effect in such a TBA is obtained, and is verified through numerical simulations. It is demonstrated that emittance preservation can be achieved with this condition, and to a large extent, has a high tolerance to the fluctuation of the initial transverse phase space distribution of the beam. (authors)

  1. Three-dimensional Microarchitecture of Adolescent Cancellous Bone

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I; Overgaard, Søren

    regarding three-dimensional (3-D) microarchitecture of normal adolescent cancellous bone. The objective of this study was to investigate 3-D microarchitecture of normal adolescent cancellous bone, and compared them with adult cancellous bone, thus seeking more insight into the subchondral bone adaptations...... of lateral condyle in the young adult. There were no statistical significances in the mechanical properties apart from the Young’s modulus of adolescent in anterior-posterior direction was significantly lower than the other groups. DISCUSSION: This is the first study on the 3-D microarchitecture of human......, Switzerland) resulting in cubic voxel sizes of 10*10*10 m3. Microarchitectural properties were calculated, and the mean values for either tibia, medial or lateral condyle were used in analyses. Furthermore, the samples were first tested non-destructively in compression in antero-posterior (AP) and medial...

  2. Analysis of Intercarrier Interference Cancellation Scheme in OFDM Systems

    Directory of Open Access Journals (Sweden)

    Nasir Salh Almisbah

    2012-06-01

    Full Text Available Abstract: Orthogonal Frequency Division Multiplexing (OFDM is an emerging multi-carrier modulation scheme, which has been adopted for several wireless standards such as IEEE 802.11a and HiperLAN2. In OFDM systems, the performance is very sensitive to subcarrier frequency errors (offset. This paper shows the analysis and derivations of intercarrier interference (ICI complex gain that used in self-cancellation scheme and its dependence on subcarrier frequency offset. Simulation shows that better improvement in performance is achieved for systems that use this cancellation scheme. Moreover, analysis and simulation show that theoretical carrier-to-interference ratio (CIR for OFDM with cancellation scheme is greater than conventional one by more than 14dB.

  3. Development of a Voice Activity Controlled Noise Canceller

    Science.gov (United States)

    Abid Noor, Ali O.; Samad, Salina Abdul; Hussain, Aini

    2012-01-01

    In this paper, a variable threshold voice activity detector (VAD) is developed to control the operation of a two-sensor adaptive noise canceller (ANC). The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE) convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods. PMID:22778667

  4. Beamforming design with proactive interference cancelation in MISO interference channels

    Science.gov (United States)

    Li, Yang; Tian, Yafei; Yang, Chenyang

    2015-12-01

    In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

  5. Development of a Voice Activity Controlled Noise Canceller

    Directory of Open Access Journals (Sweden)

    Aini Hussain

    2012-05-01

    Full Text Available In this paper, a variable threshold voice activity detector (VAD is developed to control the operation of a two-sensor adaptive noise canceller (ANC. The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods.

  6. Interference Cancellation Using Space-Time Processing and Precoding Design

    CERN Document Server

    Li, Feng

    2013-01-01

    Interference Cancellation Using Space-Time Processing and Precoding Design introduces original design methods to achieve interference cancellation, low-complexity decoding and full diversity for a series of multi-user systems. In multi-user environments, co-channel interference will diminish the performance of wireless communications systems. In this book, we investigate how to design robust space-time codes and pre-coders to suppress the co-channel interference when multiple antennas are available.   This book offers a valuable reference work for graduate students, academic researchers and engineers who are interested in interference cancellation in wireless communications. Rigorous performance analysis and various simulation illustrations are included for each design method.   Dr. Feng Li is a scientific researcher at Cornell University.

  7. The Effects of High Frequency ULF Wave Activity on the Spectral Characteristics of Coherent HF Radar Returns

    Science.gov (United States)

    Wright, D. M.; Yeoman, T. K.; Woodfield, E. E.

    2003-12-01

    It is now a common practice to employ ground-based radars in order to distinguish between those regions of the Earth's upper atmosphere which are magnetically conjugate to open and closed field lines. Radar returns from ionospheric irregularities inside the polar cap and cusp regions generally exhibit large spectral widths in contrast to those which exist on closed field lines at lower latitudes. It has been suggested that the so-called Spectral Width Boundary (SWB) might act as a proxy for the open-closed field line boundary (OCFLB), which would then be an invaluable tool for investigating reconnection rates in the magnetosphere. The exact cause of the increased spectral widths observed at very high latitudes is still subject to considerable debate. Several mechanisms have been proposed. This paper compares a dusk-sector interval of coherent HF radar data with measurements made by an induction coil magnetometer located at Tromso, Norway (66° N geomagnetic). On this occasion, a series of transient regions of radar backscatter exhibiting large spectral widths are accompanied by increases in spectral power of ULF waves in the Pc1-2 frequency band. These observations would then, seem to support the possibility that high frequency magnetospheric wave activity at least contribute to the observed spectral characteristics and that such wave activity might play a significant role in the cusp and polar cap ionospheres.

  8. PARMELA-B A new version of PARMELA with coherent synchrotron radiation effects and a finite difference space charge routine

    CERN Document Server

    Koltenbah, B E C; Greegor, R B; Dowell, D H

    2002-01-01

    Recent interest in advanced laser light sources has stimulated development of accelerator systems of intermediate beam energy, 100-200 MeV, and high charge, 1-10 nC, for high power FEL applications and high energy, 1-2 GeV, high charge, SASE-FEL applications. The current generation of beam transport codes which were developed for high-energy, low-charge beams with low self-fields are inadequate to address this energy and charge regime, and better computational tools are required to accurately calculate self-fields. To that end, we have developed a new version of PARMELA, named PARMELA_B and written in Fortran 95, which includes a coherent synchrotron radiation (CSR) routine and an improved, generalized space charge (SC) routine. An electron bunch is simulated by a collection of macro-particles, which traverses a series of beam line elements. At each time step through the calculation, the momentum of each particle is updated due to the presence of external and self- fields. The self-fields are due to CSR and S...

  9. PARMELA sub B a new version of PARMELA with coherent synchrotron radiation effects and a finite difference space charge routine

    CERN Document Server

    Koltenbah, B E C; Greegor, R B; Dowell, D H

    2002-01-01

    Recent interest in advanced laser light sources has stimulated development of accelerator systems of intermediate beam energy, 100-200 MeV, and high charge, 1-10 nC, for high power FEL applications and high energy, 1-2 GeV, high charge, SASE-FEL applications. The current generation of beam transport codes which were developed for high-energy, low-charge beams with low self-fields are inadequate to address this energy and charge regime, and better computational tools are required to accurately calculate self-fields. To that end, we have developed a new version of PARMELA, named PARMELA sub B and written in Fortran 95, which includes a coherent synchrotron radiation (CSR) routine and an improved, generalized space charge (SC) routine. An electron bunch is simulated by a collection of macro-particles, which traverses a series of beam line elements. At each time step through the calculation, the momentum of each particle is updated due to the presence of external and self-fields. The self-fields are due to CSR an...

  10. Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

    Science.gov (United States)

    Gross, Christian; Lebedev, Oleg; Toma, Takashi

    2017-11-10

    We consider a simple Higgs portal dark-matter model, where the standard model is supplemented with a complex scalar whose imaginary part plays the role of weakly interacting massive particle dark matter (DM). We show that the direct DM detection cross section vanishes at the tree level and zero momentum transfer due to a cancellation by virtue of a softly broken symmetry. This cancellation is operative for any mediator masses. As a result, our electroweak-scale dark matter satisfies all of the phenomenological constraints quite naturally.

  11. Interference Cancelation Schemes for Uplink Transmission in Femtocells

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar

    2010-01-01

    We present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. We introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high......-rate link between the macrocell base station (BS) and the femtocell BS. In such a way, the interference from macrocell transmitters is completely cancelled when uplink transmission is used in the femtocell. Therefore, the allocation of time slots for uplink/downlink in a femtocell can be done by trying only...

  12. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual......-polarized patch antennas operating at 2.4 GHz is described. The measurement results show an average of 60 dB self-interference cancellation over 200 MHz bandwidth. Moreover, a decoupling level of up to 22 dB is achieved for MIMO multiplexing using antenna polarization diversity. The performance evaluation...

  13. Diagrammatic cancellations and the gauge dependence of QED

    Energy Technology Data Exchange (ETDEWEB)

    Kißler, Henry, E-mail: kissler@physik.hu-berlin.de [Department of Mathematical Sciences, University of Liverpool, L69 7ZL, Liverpool (United Kingdom); Department of Mathematics, Humboldt-Universität zu Berlin, Rudower Chaussee 25, D-12489 Berlin (Germany); Kreimer, Dirk, E-mail: kreimer@math.hu-berlin.de [Department of Mathematics, Humboldt-Universität zu Berlin, Rudower Chaussee 25, D-12489 Berlin (Germany)

    2017-01-10

    This letter examines diagrammatic cancellations for Quantum Electrodynamics (QED) in the general linear gauge. These cancellations combine Feynman graphs of various topologies and provide a method to reconstruct the gauge dependence of the electron propagator from the result of a particular gauge by means of a linear Dyson–Schwinger equation. We use this method in combination with dimensional regularization to demonstrate how the 3-loop ε-expansion in the Feynman gauge determines the ε-expansions for all gauge parameter dependent terms to 4 loops.

  14. Successive approximation algorithm for cancellation of artifacts in DSA images

    International Nuclear Information System (INIS)

    Funakami, Raiko; Hiroshima, Kyoichi; Nishino, Junji

    2000-01-01

    In this paper, we propose an algorithm for cancellation of artifacts in DSA images. We have already proposed an automatic registration method based on the detection of local movements. When motion of the object is large, it is difficult to estimate the exact movement, and the cancellation of artifacts may therefore fail. The algorithm we propose here is based on a simple rigid model. We present the results of applying the proposed method to a series of experimental X-ray images, as well as the results of applying the algorithm as preprocessing for a registration method based on local movement. (author)

  15. Noninvadability implies noncoexistence for a class of cancellative systems

    Czech Academy of Sciences Publication Activity Database

    Swart, Jan M.

    2013-01-01

    Roč. 18, č. 38 (2013), s. 1-12 ISSN 1083-589X R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : cancellative system * interface tightness * duality * coexistence * Neuhauser-Pacala model * affine voter model * rebellious voter model * balancing selection * branching * annihilation * parity preservation Subject RIV: BA - General Mathematics Impact factor: 0.627, year: 2013 http://library.utia.cas.cz/separaty/2013/SI/swart-noninvadability implies noncoexistence for a class of cancellative systems.pdf

  16. Stimulated coherent transition radiation

    International Nuclear Information System (INIS)

    Hung-chi Lihn.

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  17. Investigating the Role of Coherence Effects on Jet Quenching in Pb-Pb Collisions at √{sNN} = 2.76 TeV using Jet Substructure

    Science.gov (United States)

    Zardoshti, Nima; Alice Collaboration

    2017-11-01

    We report measurements of two jet shapes, the ratio of 2-Subjettiness to 1-Subjettiness (τ2 /τ1) and the opening angle between the two axes of the 2-Subjettiness jet shape, which is obtained by reclustering the jet with the exclusive-kT algorithm [S.D.Ellis and D.E.Soper, Phys.Rev.B 48, 3160] and undoing the final clustering step. The aim of this measurement is to explore a possible change in the rate of 2-pronged objects in Pb-Pb compared to pp due to colour coherence. Coherence effects [Y.Mehtar-Tani, C.A.Salgado and K.Tywoniuk Phys. Rev. Lett. 106:122002, 2011] relate to the ability of the medium to resolve a jet's substructure, which has an impact on the energy loss magnitude and mechanism of the traversing jet. In both collision systems charged jets are found with the anti-kT algorithm [M.Cacciari, G.P.Salam and G.Soyez JHEP 0804:063, 2008], a resolution parameter of R = 0.4 and a constituent cut off of 0.15 GeV. This analysis uses hadron-jet coincidence techniques in Pb-Pb collisions to reject the combinatorial background and corrects further for background effects by employing various jet shape subtraction techniques and two dimensional unfolding. Measurements of the Nsubjettiness for jet momenta of 40-60 GeV/c in Pb-Pb collisions at √{sNN} = 2.76 TeV and pp collisions at √{ s} = 7 TeV will be presented and compared to PYTHIA simulations.

  18. An assessment of core wide coherency effects in the multichannel modeling of the initiating phase of a severe accident in a sodium fast reactor

    International Nuclear Information System (INIS)

    Guyot, M.; Gubernatis, P.; Suteau, C.; Le Tellier, R.; Lecerf, J.

    2014-01-01

    To consolidate the safety assessment for liquid-metal fast breeder reactors (LMFBRs), hypothetical core disruptive accident (HCDA) sequences have been extensively studied over the past decades. Numerous analyses of the so called initiating phase (or primary phase) of a HCDA have been made with the safety analysis system code SAS4A. The SAS4A accident analysis code requires that subassemblies or groups of subassemblies be represented together as independent channels. For simulating a severe accident sequence, a subassembly-to-channel assignment procedure has to be implemented to produce the consistent SAS4A input decks. Generally, one uses imposed criteria over relevant reactor parameters to determine the subassembly to- channel arrangement. The multiple-assembly-per-channel approach introduces core wide coherency effects, which can affect the reactivity balance and therefore the overall accident development. In this paper, a subassembly-to channel assignment procedure based on the subassembly power-to-flow ratio is presented and implemented to generate the SAS4A input decks over a range of parameter values. The corresponding SAS4A calculations have been performed on a large LMFBR. The purpose of the present series of calculations is to investigate the magnitude of errors encountered in the analysis of the initiating phase related to the subassembly-to-channel arrangement selection, by comparison with a one-subassembly-per-channel reference solution. It appears that a refinement in the channel arrangement substantially reduces core wide coherency effects. Analysis of the calculations also suggests that an accurate representation of the scenario requires the number of channels to be on approximately the same order of magnitude as the total number of subassemblies. Numerical results are examined to provide the reader with quantitative measurements of bias related to subassembly to- channel arrangement. (authors)

  19. Comparison between optical coherence tomography technique and mechanical compression assay to evaluate ionizing radiation effects in frozen and lyophilized bone Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Santin, Stefany Plumeri; Freitas, Anderson Zanardi de; Martinho Junior, Antonio Carlos; Dias, Djalma Batista; Soares, Fernando Augusto Neves; Pino, Eddy Segura; Veloso, Marcelo Noronha; Mathor, Monica B., E-mail: spsantin@usp.br, E-mail: mathor@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Santos, Luiz Augusto Ubirajara, E-mail: augustosantos@terra.com.br [Universidade de Sao Paulo (IOT/HCFUSP), Sao Paulo, SP (Brazil). Fac. de Medicina. Instituto de Ortopedia e Traumatologia

    2013-07-01

    Currently tissue banks have utilized ionizing radiation to sterilize bone tissues to be used as allograft. This method is advantageous when compared with other techniques, because the tissue is sterilized in its final packaging avoiding later contaminations, another advantage is due to the fact occur only a minimal increase in temperature, in addition to provide a Sterility Assurance Level (SAL) of 10{sup -6}, as recommended by national and international standards. However, there are several studies investigating the modifications that this method of sterilization may cause to the bone matrix, for example, alterations in the resistance to compression force. The compressive mechanical tests are highly used to evaluate the decrease in the mechanical strength; however it is a destructive assay. In this study, we used Optical Coherence Tomography to evaluate these possible changes. This technique is advantageous, for do not destroy the sample and enable the performing of other assays with the same sample. In literature, it is possible to find several studies about mechanical changes occasioned by destructive tests. Therefore, this study aims to compare the results of both techniques. It was selected four donors to obtain eight samples of fibula, through a partnership with the Tissue Bank (Instituto de Traumatologia do Hospital das Clinicas da Universidade de Sao Paulo). From each donor were separated twelve samples for preservation by freezing and twelve samples for preservation by lyophilization. The samples were analyzed by Optical Coherence Tomography (OCT) after irradiation at different doses (15, 25 and 50 kGy), in addition to non-irradiated control. After the samples were analyzed by Optical Coherence Tomography the same were subjected to mechanical testing. The data were analyzed by software developed by Dr. Anderson Zanardi de Freitas to calculate the total attenuation coefficient of photons. Nevertheless, only the preservation method may induce to alterations

  20. Comparison between optical coherence tomography technique and mechanical compression assay to evaluate ionizing radiation effects in frozen and lyophilized bone Tissue

    International Nuclear Information System (INIS)

    Santin, Stefany Plumeri; Freitas, Anderson Zanardi de; Martinho Junior, Antonio Carlos; Dias, Djalma Batista; Soares, Fernando Augusto Neves; Pino, Eddy Segura; Veloso, Marcelo Noronha; Mathor, Monica B.; Santos, Luiz Augusto Ubirajara

    2013-01-01

    Currently tissue banks have utilized ionizing radiation to sterilize bone tissues to be used as allograft. This method is advantageous when compared with other techniques, because the tissue is sterilized in its final packaging avoiding later contaminations, another advantage is due to the fact occur only a minimal increase in temperature, in addition to provide a Sterility Assurance Level (SAL) of 10 -6 , as recommended by national and international standards. However, there are several studies investigating the modifications that this method of sterilization may cause to the bone matrix, for example, alterations in the resistance to compression force. The compressive mechanical tests are highly used to evaluate the decrease in the mechanical strength; however it is a destructive assay. In this study, we used Optical Coherence Tomography to evaluate these possible changes. This technique is advantageous, for do not destroy the sample and enable the performing of other assays with the same sample. In literature, it is possible to find several studies about mechanical changes occasioned by destructive tests. Therefore, this study aims to compare the results of both techniques. It was selected four donors to obtain eight samples of fibula, through a partnership with the Tissue Bank (Instituto de Traumatologia do Hospital das Clinicas da Universidade de Sao Paulo). From each donor were separated twelve samples for preservation by freezing and twelve samples for preservation by lyophilization. The samples were analyzed by Optical Coherence Tomography (OCT) after irradiation at different doses (15, 25 and 50 kGy), in addition to non-irradiated control. After the samples were analyzed by Optical Coherence Tomography the same were subjected to mechanical testing. The data were analyzed by software developed by Dr. Anderson Zanardi de Freitas to calculate the total attenuation coefficient of photons. Nevertheless, only the preservation method may induce to alterations in

  1. Spectral domain optical coherence tomography as an effective screening test for hydroxychloroquine retinopathy (the "flying saucer" sign).

    Science.gov (United States)

    Chen, Eric; Brown, David M; Benz, Matthew S; Fish, Richard H; Wong, Tien P; Kim, Rosa Y; Major, James C

    2010-10-21

    While the long-term incidence of hydroxychloroquine (HCQ) retinopathy is low, there remains no definitive clinical screening test to recognize HCQ toxicity before ophthalmoscopic fundus changes or visual symptoms. Patients receiving HCQ were evaluated with spectral domain optical coherence tomography (SD OCT) to assess the feasibility of identifying HCQ retinopathy at an early stage. Twenty-five patients referred for the evaluation of hydroxychloroquine toxicity underwent a comprehensive ocular examination, Humphrey visual field (HVF) perimetry, time domain OCT, and SD OCT. Some patients with screening abnormalities also underwent further diagnostic testing at the discretion of the treating providers. Five patients were found to have SD OCT findings corresponding to HCQ toxicity and retinal damage as seen by clinical exam and/or HVF perimetry. Two patients with advanced toxicity were found to have significant outer retina disruption in the macula on SD OCT. Three patients with early HCQ toxicity and HVF 10-2 perifoveal defects were found to have loss of the perifoveal photoreceptor inner segment/outer segment (IS/OS) junction with intact outer retina directly under the fovea, creating the "flying saucer" sign. While two of these three patients had early ophthalmoscopic fundus changes, one had none. Outer retinal abnormalities including perifoveal photoreceptor IS/OS junction disruption can be identified by SD OCT in early HCQ toxicity, sometimes even before ophthalmoscopic fundus changes are apparent. SD OCT may have a potential complementary role in screening for HCQ retinopathy due to its quick acquisition and because it is more objective than automated perimetry.

  2. Multi-jet correlations and colour coherence phenomena

    Directory of Open Access Journals (Sweden)

    Lee Jason S.H.

    2017-01-01

    Full Text Available In multi-jet events, colour coherence was shown to play a important role in the topology of these events. In modern Monte Carlo generators, the colour coherence effect has become an inherent feature, such that the colour coherence effect can no longer be disentangled in a simple manner. This study looks at the multi-jet correlations by comparing Monte Carlo generators in Parton Shower dominant and Matrix Element dominant regions.

  3. 77 FR 64794 - Cancellation of the National Agricultural Research, Extension, Education, and Economics Advisory...

    Science.gov (United States)

    2012-10-23

    ... Cancellation of the National Agricultural Research, Extension, Education, and Economics Advisory Board Meeting AGENCY: Research, Education, and Economics, USDA. ACTION: Notice of intent to cancel meeting. SUMMARY: The meeting of the National Agricultural Research, Extension, Education, and Economics Advisory Board...

  4. 77 FR 69840 - Iodomethane; Notice of Receipt of Request to Voluntarily Cancel Iodomethane Pesticide...

    Science.gov (United States)

    2012-11-21

    ... of Request to Voluntarily Cancel Iodomethane Pesticide Registrations and Amend a Registration AGENCY... voluntarily cancel the registrations of products containing the pesticide iodomethane. In addition, the... deadline identified. [[Page 69841

  5. Different phase delays of peripheral input to primate motor cortex and spinal cord promote cancellation at physiological tremor frequencies.

    Science.gov (United States)

    Koželj, Saša; Baker, Stuart N

    2014-05-01

    Neurons in the spinal cord and motor cortex (M1) are partially phase-locked to cycles of physiological tremor, but with opposite phases. Convergence of spinal and cortical activity onto motoneurons may thus produce phase cancellation and a reduction in tremor amplitude. The mechanisms underlying this phase difference are unknown. We investigated coherence between spinal and M1 activity with sensory input. In two anesthetized monkeys, we electrically stimulated the medial, ulnar, deep radial, and superficial radial nerves; stimuli were timed as independent Poisson processes (rate 10 Hz). Single units were recorded from M1 (147 cells) or cervical spinal cord (61 cells). Ninety M1 cells were antidromically identified as pyramidal tract neurons (PTNs); M1 neurons were additionally classified according to M1 subdivision (rostral/caudal, M1r/c). Spike-stimulus coherence analysis revealed significant coupling over a broad range of frequencies, with the strongest coherence at <50 Hz. Delays implied by the slope of the coherence phase-frequency relationship were greater than the response onset latency, reflecting the importance of late response components for the transmission of oscillatory inputs. The spike-stimulus coherence phase over the 6-13 Hz physiological tremor band differed significantly between M1 and spinal cells (phase differences relative to the cord of 2.72 ± 0.29 and 1.72 ± 0.37 radians for PTNs from M1c and M1r, respectively). We conclude that different phases of the response to peripheral input could partially underlie antiphase M1 and spinal cord activity during motor behavior. The coordinated action of spinal and cortical feedback will act to reduce tremulous oscillations, possibly improving the overall stability and precision of motor control. Copyright © 2014 the American Physiological Society.

  6. Kit W-sh Mutation Prevents Cancellous Bone Loss during Calcium Deprivation.

    Science.gov (United States)

    Lotinun, Sutada; Suwanwela, Jaijam; Poolthong, Suchit; Baron, Roland

    2018-01-01

    Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit W /Kit W-v /J (W/W v ) mice with c-Kit point mutation, Kit W-sh /HNihrJaeBsmJ (W sh /W sh ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W v and W sh /W sh mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W v mice. In contrast, W sh /W sh cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W sh /W sh mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W sh mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W sh /W sh mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.

  7. Photonic-Enabled RF Canceller with Tunable Time-Delay Taps

    Science.gov (United States)

    2016-12-05

    Photonic -Enabled RF Canceller with Tunable Time-Delay Taps Kenneth E. Kolodziej, Sivasubramaniam Yegnanarayanan, Bradley T. Perry MIT Lincoln...canceller design that uses photonics and a vector modulator architecture to provide a high number of canceller taps with tunable time-delays, which allow...microwave photonics , RF cancellation. I. INTRODUCTION In-Band Full-Duplex (IBFD) technologies are being consid- ered for 5th generation (5G) wireless

  8. COHERENT Experiment: current status

    International Nuclear Information System (INIS)

    Akimov, D; Belov, V; Bolozdynya, A; Burenkov, A; Albert, J B; Del Valle Coello, M; D’Onofrio, M; Awe, C; Barbeau, P S; Cervantes, M; Becker, B; Cabrera-Palmer, B; Collar, J I; Cooper, R J; Cooper, R L; Cuesta, C; Detwiler, J; Eberhardt, A; Dean, D; Dolgolenko, A G

    2017-01-01

    The COHERENT Collaboration is realizing a long term neutrino physics research program. The main goals of the program are to detect and study elastic neutrino-nucleus scattering (CEνNS). This process is predicted by Standard Model but it has never been observed experimentally because of the very low energy of the recoil nucleus. COHERENT is using different detector technologies: CsI[Na] and NaI scintillator crystals, a single-phase liquid Ar and a Ge detectors. The placement of all the detector setups is in the basement of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The current status of the COHERENT experimental program is presented. (paper)

  9. Dynamic coherent backscattering mirror

    Energy Technology Data Exchange (ETDEWEB)

    Zeylikovich, I.; Xu, M., E-mail: mxu@fairfield.edu [Physics Department, Fairfield University, Fairfield, CT 06824 (United States)

    2016-02-15

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

  10. Chromospheric Heating due to Cancellation of Quiet Sun Internetwork Fields

    Science.gov (United States)

    Gošić, M.; de la Cruz Rodríguez, J.; De Pontieu, B.; Bellot Rubio, L. R.; Carlsson, M.; Esteban Pozuelo, S.; Ortiz, A.; Polito, V.

    2018-04-01

    The heating of the solar chromosphere remains one of the most important questions in solar physics. Our current understanding is that small-scale internetwork (IN) magnetic fields play an important role as a heating agent. Indeed, cancellations of IN magnetic elements in the photosphere can produce transient brightenings in the chromosphere and transition region. These bright structures might be the signature of energy release and plasma heating, probably driven by the magnetic reconnection of IN field lines. Although single events are not expected to release large amounts of energy, their global contribution to the chromosphere may be significant due to their ubiquitous presence in quiet Sun regions. In this paper, we study cancellations of IN elements and analyze their impact on the energetics and dynamics of the quiet Sun atmosphere. We use high-resolution, multiwavelength, coordinated observations obtained with the Interface Region Imaging Spectrograph and the Swedish 1 m Solar Telescope (SST) to identify cancellations of IN magnetic flux patches and follow their evolution. We find that, on average, these events live for ∼3 minutes in the photosphere and ∼12 minutes in the chromosphere and/or transition region. Employing multi-line inversions of the Mg II h and k lines, we show that cancellations produce clear signatures of heating in the upper atmospheric layers. However, at the resolution and sensitivity accessible to the SST, their number density still seems to be one order of magnitude too low to explain the global chromospheric heating.

  11. Canceling Some d-CON Mouse and Rat Control Products

    Science.gov (United States)

    EPA has reached agreement with the manufacturer, to cancel 12 d-CON products that do not meet our testing protocols that better protect children, pets and non-target wildlife from accidental exposure to the pesticide. These products will be phased out.

  12. 76 FR 16415 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2011-03-23

    ...-00050 1% Rotenone Garden Dust Rotenone Cube Resins other than rotenone. 028293-00042 Unicorn Ear Mite... registrants of the products in Table 1 of this unit, in sequence by EPA company number. This number.... Table 2--Registrants of Canceled Products EPA company No. Company name and address 4 Bonide Products...

  13. 76 FR 10587 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2011-02-25

    ...-00160 Unicorn House and Phenothrin Carpet Spray 11. Tetramethrin 028293-00215 Unicorn IGR Phenothrin... company number. This number corresponds to the first part of the EPA registration numbers of the products listed in this unit. Table 4 --Registrants of Cancelled Products Company No. Company name and address 192...

  14. 77 FR 50702 - Cardiovascular and Renal Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2012-08-22

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001] Cardiovascular and Renal Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Cardiovascular and Renal Drugs Advisory Committee scheduled for...

  15. 78 FR 68779 - Controlled Group Regulation Examples; Hearing Cancellation

    Science.gov (United States)

    2013-11-15

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [REG-114122-12] RIN 1545-BK96 Controlled Group Regulation Examples; Hearing Cancellation AGENCY: Internal Revenue Service (IRS), Treasury... controlled group rules related to regulated investment companies. DATES: The public hearing originally...

  16. Incidence, causes and pattern of cancellation of Elective surgical ...

    African Journals Online (AJOL)

    This study was carried out to assess the incidence, causes and pattern of cancellation of elective surgical operations in our setting and to find the appropriate solutions for better patient management. Methods: This was a prospective hospital-based study which was conducted in a teaching hospital at Bugando medical ...

  17. Revenue Management under Customer Choice Behaviour with Cancellations and Overbooking

    NARCIS (Netherlands)

    D.D. Sierag (Dirk); G.M. Koole (Ger); R.D. van der Mei (Rob); JP.I. van der Rest (Jean-Pierre); A.P. Zwart (Bert)

    2015-01-01

    htmlabstractRevenue management is the practice of pricing perishable goods to optimise revenue. A realistic revenue management model allows overbooking and incorporates customer buying behaviour and cancellations. The latter is motivated by our research using real data, which shows that for a

  18. 19 CFR 10.39 - Cancellation of bond charges.

    Science.gov (United States)

    2010-04-01

    ... covering articles entered under other provisions of law shall not be canceled upon proof of destruction... entered temporarily free of duty under bond are destroyed within the bond period by death, accidental fire... (including any lawful extension), the Fines, Penalties, and Forfeitures Officer shall make a demand in...

  19. Laboratory Investigation of Noise-Canceling Headphones Utilizing "Mr. Blockhead"

    Science.gov (United States)

    Koser, John

    2013-01-01

    While I was co-teaching an introductory course in musical acoustics a few years ago, our class investigated several pieces of equipment designed for audio purposes. One piece of such equipment was a pair of noise-canceling headphones. Our students were curious as to how these devices were in eliminating background noise and whether they indeed…

  20. Economic impact of surgery cancellation in a general hospital, Iran

    African Journals Online (AJOL)

    unhcc

    cause of inefficient use of operating room (OR) time and a drain on finite .... of total hospitalizations. In this hospital (270 beds ... Preoperative instructions not followed or patient not instructed. Change in .... concrete possibilities of reducing the level of surgical cancellations by .... room case-mix problem under uncertainty and.

  1. 41 CFR 101-27.303-1 - Cancellation or transfer.

    Science.gov (United States)

    2010-07-01

    ..., including quantities due in from procurement, is greater than 10 percent of the total stock of that item... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Cancellation or transfer. 101-27.303-1 Section 101-27.303-1 Public Contracts and Property Management Federal Property Management...

  2. 75 FR 30824 - Methidathion; Cancellation Order for Pesticide Registrations

    Science.gov (United States)

    2010-06-02

    ... distribution, sale, or use of existing stocks of the products identified in Unit II., Table 1, in a manner..., 2010, Federal Register notice of receipt of requests from the registrants listed in Unit II., Table 2... Table 1 of this unit. Table 1.--Methidathion Product Cancellations Registration Number Product Name...

  3. 78 FR 59019 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-09-25

    ... distribution, sale, or use of existing stocks of the products identified in Table 1 of Unit II. in a manner... accepted by the Agency, of the products listed in Table 1 of Unit II., pursuant to the Federal Insecticide... Notice of Receipt of Requests from the registrants listed in Table 2 of Unit II. to voluntarily cancel...

  4. 78 FR 57850 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-09-20

    ... identified in Table 1 of Unit II., in a manner inconsistent with any of the provisions for disposition of... accepted by the Agency, of the products listed in Table 1 of Unit II., pursuant to the Federal Insecticide... Notice of Receipt of Requests from the registrants listed in Table 2 of Unit II. to voluntarily cancel...

  5. 75 FR 40825 - Clofencet; Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2010-07-14

    ... existing stocks of the products identified in Table 1 of Unit II. in a manner inconsistent with any of the... number in Table 1 of this unit. Table 1.--Clofencet Product Cancellations EPA Registration Number Product... Manufacturing Use Product Table 2 of this unit includes the name and address of record for the registrant of the...

  6. 75 FR 11898 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641), and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  7. 76 FR 22912 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-04-25

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, DHS. ACTION: General Notice. SUMMARY: Pursuant to section 641 of the Tariff Act of 1930, as amended (19 U.S.C. 1641), and the U.S. Customs and...

  8. 77 FR 5819 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2012-02-06

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  9. 75 FR 5618 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-02-03

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  10. 76 FR 7873 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2011-02-11

    ... DEPARTMENT OF HOMELAND SECURITY Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security. ACTION...), and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  11. 77 FR 43609 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2012-07-25

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.53), the following Customs...

  12. 76 FR 44032 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-07-22

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  13. 75 FR 47825 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-08-09

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  14. 75 FR 76998 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-12-10

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  15. 77 FR 74022 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2012-12-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION...) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs broker...

  16. 76 FR 2918 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-01-18

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  17. 75 FR 11899 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  18. 76 FR 13205 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-03-10

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.45), the following Customs...

  19. 75 FR 75691 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-12-06

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.45), the following Customs...

  20. 75 FR 47825 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-08-09

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  1. Cut cancellation in the planar integral equation for the Reggeon

    International Nuclear Information System (INIS)

    Bishari, M.; Veneziano, G.

    1975-01-01

    Planar unitarity for the Reggeon, analyticity and the multi-Regge assumption with cluster production lead to integral equations of the Chew-Goldberger-Low type with separable self-consistent kernel. Contrary to common prejudice, the authors show the existence of solutions exhibiting moving poles and exact, non-perturbative cancellation of the cut. Previously studied consistency conditions are rederived. (Auth.)

  2. 78 FR 22846 - Smart Grid Advisory Committee Meeting Cancellation

    Science.gov (United States)

    2013-04-17

    ...The meeting of the Smart Grid Advisory Committee (SGAC or Committee) scheduled for Friday, April 19, 2013 from 8:30 a.m. to 5:00 p.m. Eastern Time is cancelled. Notice of this meeting was published in the Federal Register on March 26, 2013.

  3. Clinical Utility of Cancellation on the WISC-IV

    Science.gov (United States)

    Zhu, Jianjun; Chen, Hsinyi

    2013-01-01

    This study examined empirical evidence for clinical utility of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) cancellation subtest by comparing data from 597 clinical and 597 matched control children. The results of dependent t and sequential logistic regression analyses demonstrated that (a) children with intellectual…

  4. 78 FR 64211 - FIFRA Scientific Advisory Panel; Notice of Cancellation

    Science.gov (United States)

    2013-10-28

    ..., Office of Science Coordination and Policy (7201M), Environmental Protection Agency, 1200 Pennsylvania Ave... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2013-0490; FRL-9902-06] FIFRA Scientific Advisory Panel; Notice of Cancellation AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY...

  5. 75 FR 81283 - Oncologic Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2010-12-27

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0001] Oncologic Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Oncologic Drugs Advisory Committee scheduled for February 9, 2011, is...

  6. 77 FR 63839 - Oncologic Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2012-10-17

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001] Oncologic Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Oncologic Drugs Advisory Committee Meeting scheduled for November 8, 2012, is...

  7. A deconvolution method for deriving the transit time spectrum for ultrasound propagation through cancellous bone replica models.

    Science.gov (United States)

    Langton, Christian M; Wille, Marie-Luise; Flegg, Mark B

    2014-04-01

    The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound.

  8. PARMELAB: a new version of PARMELA with coherent synchrotron radiation effects and a finite difference space charge routine

    International Nuclear Information System (INIS)

    Koltenbah, B.E.C.; Parazzoli, Claudio G.; Greegor, Robert B.; Dowell, David H.

    2002-01-01

    Recent interest in advanced laser light sources has stimulated development of accelerator systems of intermediate beam energy, 100-200 MeV, and high charge, 1-10 nC, for high power FEL applications and high energy, 1-2 GeV, high charge, SASE-FEL applications. The current generation of beam transport codes which were developed for high-energy, low-charge beams with low self-fields are inadequate to address this energy and charge regime, and better computational tools are required to accurately calculate self-fields. To that end, we have developed a new version of PARMELA, named PARMELA B and written in Fortran 95, which includes a coherent synchrotron radiation (CSR) routine and an improved, generalized space charge (SC) routine. An electron bunch is simulated by a collection of macro-particles, which traverses a series of beam line elements. At each time step through the calculation, the momentum of each particle is updated due to the presence of external and self-fields. The self-fields are due to CSR and SC. For the CSR calculations, the macro-particles are further combined into macro-particle-bins that follow the central trajectory of the bend. The energy change through the time step is calculated from expressions derived from the Lienard-Wiechart formulae, and from this energy change the particle's momentum is updated. For the SC calculations, we maintain the same rest-frame-electrostatic approach of the original PARMELA; however, we employ a finite difference Poisson equation solver instead of the symmetrical ring algorithm of the original code. In this way, we relax the symmetry assumptions in the original code. This method is based upon standard numerical procedures and conserves momentum to first order. The SC computational grid is adaptive and conforms to the size of the pulse as it evolves through the calculation. We provide descriptions of these two algorithms, validation comparisons with other CSR and SC methods, and a limited comparison with

  9. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Themstrup, Lotte; Banzhaf, Christina

    2014-01-01

    Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described as the o......Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described...

  10. Coherent light microscopy

    CERN Document Server

    Ferraro, Pietro; Zalevsky, Zeev

    2011-01-01

    This book deals with the latest achievements in the field of optical coherent microscopy. While many other books exist on microscopy and imaging, this book provides a unique resource dedicated solely to this subject. Similarly, many books describe applications of holography, interferometry and speckle to metrology but do not focus on their use for microscopy. The coherent light microscopy reference provided here does not focus on the experimental mechanics of such techniques but instead is meant to provide a users manual to illustrate the strengths and capabilities of developing techniques. Th

  11. 21 CFR 1305.19 - Cancellation and voiding of DEA Forms 222.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Cancellation and voiding of DEA Forms 222. 1305.19... I AND II CONTROLLED SUBSTANCES DEA Form 222 § 1305.19 Cancellation and voiding of DEA Forms 222. (a) A purchaser may cancel part or all of an order on a DEA Form 222 by notifying the supplier in...

  12. 77 FR 59190 - Halofenozide; Notice of Receipt of Requests To Voluntarily Cancel Pesticide Registrations and...

    Science.gov (United States)

    2012-09-26

    ... of Requests To Voluntarily Cancel Pesticide Registrations and Terminate All Uses AGENCY... voluntarily cancel pesticide registrations of all products containing the pesticide halofenozide. The requests would cancel all technical and end-use registrations and delete all halofenozide uses. The requests...

  13. 78 FR 15949 - Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2013-03-13

    ... Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA). ACTION... is issuing a notice of receipt of requests by a registrant to voluntarily cancel certain pesticide... in this notice will be permitted after the registration has been canceled only if such sale...

  14. 75 FR 68012 - Notice of Intention To Cancel Registrations of Certain Transfer Agents

    Science.gov (United States)

    2010-11-04

    ... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-63211] Notice of Intention To Cancel... Securities Exchange Act of 1934 (``Act''),\\1\\ cancelling the registrations of the transfer agents whose names... 20549-7010 or by e- mail at [email protected] with the phrase ``Notice of Intention To Cancel...

  15. 75 FR 22404 - Clofencet; Notice of Receipt of Request to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-04-28

    ... Request to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel their registrations of certain products containing the pesticide clofencet. The request... cancelled only if such sale, distribution, or use is consistent with the terms as described in the final...

  16. 75 FR 52340 - Fenoxycarb; Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-08-25

    ... of Request To Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection... registrants to voluntarily cancel registrations of products containing the pesticide fenoxycarb. The request... listed in this notice will be permitted after the registrations have been canceled only if such sale...

  17. 41 CFR 102-74.500 - Can Federal agencies disapprove permit applications or cancel issued permits?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Can Federal agencies disapprove permit applications or cancel issued permits? 102-74.500 Section 102-74.500 Public Contracts and... cancel issued permits? Yes, Federal agencies may disapprove any permit application or cancel an issued...

  18. 76 FR 36535 - Dicofol; Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2011-06-22

    ... Request To Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... registrants to voluntarily cancel their registrations of all products containing the pesticide dicofol. The... the registrations have been cancelled only if such sale, distribution, or use is consistent with the...

  19. 75 FR 28019 - Resmethrin; Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-05-19

    ... of Requests to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection... registrants to voluntarily cancel their registrations of certain products containing the pesticide resmethrin... after the registration has been cancelled only if such sale, distribution, or use is consistent with the...

  20. 75 FR 32766 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-06-09

    ... to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... or Mosquitoes, LLC., to voluntarily cancel the pesticide registration for the product, Biter Fighter... registrant requested a waiver of the 180-day comment period, orders will be issued canceling this...