Sample records for ultra-stable oscillator uso

  1. Measurements of Ultra-Stable Oscillator (USO) Allan Deviations in Space

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, William M.; Wang, Rabi T.; Dunn, Charles E.

    2013-01-01

    Researchers have used data from the GRAIL mission to the Moon to make the first in-flight verification of ultra-stable oscillators (USOs) with Allan deviation below 10 13 for 1-to-100-second averaging times. USOs are flown in space to provide stable timing and/or navigation signals for a variety of different science and programmatic missions. The Gravity Recovery and Interior Laboratory (GRAIL) mission is flying twin spacecraft, each with its own USO and with a Ka-band crosslink used to measure range fluctuations. Data from this crosslink can be combined in such a way as to give the relative time offsets of the two spacecrafts USOs and to calculate the Allan deviation to describe the USOs combined performance while orbiting the Moon. Researchers find the first direct in-space Allan deviations below 10(exp -13) for 1-to-100-second averaging times comparable to pre-launch data, and better than measurements from ground tracking of an X-band carrier coherent with the USO. Fluctuations in Earth s atmosphere limit measurement performance in direct-to-Earth links. Inflight USO performance verification was also performed for GRAIL s parent mission, the Gravity Recovery and Climate Experiment (GRACE), using both Kband and Ka-band crosslinks.

  2. Ultra-Stable Oscillators for Probe Radio Science Investigations

    NASA Technical Reports Server (NTRS)

    Asmar, Sami

    2012-01-01

    An Ultra-Stable Oscillator (USO) is: A frequency reference, and A clock It is stable, small, and sensitive. It is a science and an art form. It is flown on spacecraft/probes. It]is utilized at ground stations alone or as a cleanup loop. It eliminates lock-up time on uplink for occultation egress & effect of media on uplink signal. It has enabled significant planetary science investigations.

  3. A low power cryocooled autonomous ultra-stable oscillator

    NASA Astrophysics Data System (ADS)

    Fluhr, C.; Dubois, B.; Grop, S.; Paris, J.; Le Tetû, G.; Giordano, V.

    2016-12-01

    We present the design and the preliminary evaluation of a cryostat equipped with a low power pulse-tube cryocooler intended to maintain near 5 K a high-Q factor sapphire microwave resonator. This cooled resonator constitutes the frequency reference of an ultra-stable oscillator presenting a short term fractional frequency stability of better than 1 ×10-15 . The proposed design enables to reach a state-of-the-art frequency stability with a cryogenic oscillator consuming only 3 kW of electrical power.

  4. Trends in Performance and Characteristics of Ultra-Stable Oscillators for Deep Space Radio Science Experiments

    NASA Technical Reports Server (NTRS)

    Asmar, Sami

    1997-01-01

    Telecommunication systems of spacecraft on deep space missions also function as instruments for Radio Science experiments. Radio scientists utilize the telecommunication links between spacecraft and Earth to examine very small changes in the phase/frequency, amplitude, and/or polarization of radio signals to investigate a host of physical phenomena in the solar system. Several missions augmented the radio communication system with an Ultra-Stable Oscillator (USO) in order to provide a highly stable reference signal for oneway downlink. This configuration is used in order to enable better investigations of the atmospheres of the planets occulting the line-of-sight to the spacecraft; one-way communication was required and the transponders' built-in auxiliary oscillators were neither sufficiently stable nor spectrally pure for the occultation experiments. Since Radio Science instrumentation is distributed between the spacecraft and the ground stations, the Deep Space Network (DSN) is also equipped to function as a world-class instrument for Radio Science research. For a detailed account of Radio Science experiments, methodology, key discoveries, and the DSN's historical contribution to the field, see Asmar and Renzetti (1993). The tools of Radio Science can be and have also been utilized in addressing several mission engineering challenges; e.g., characterization of spacecraft nutation and anomalous motion, antenna calibrations, and communications during surface landing phases. Since the first quartz USO was flown on Voyager, the technology has advanced significantly, affording future missions higher sensitivity in reconstructing the temperature pressure profiles of the atmospheres under study as well as other physical phenomena of interest to Radio Science. This paper surveys the trends in stability and spectral purity performance, design characteristics including size and mass, as well as cost and history of these clocks in space.

  5. Analysis of South Atlantic Anomaly perturbations on Sentinel-3A Ultra Stable Oscillator. Impact on DORIS phase measurement and DORIS station positioning

    NASA Astrophysics Data System (ADS)

    Jalabert, Eva; Mercier, Flavien

    2018-07-01

    DORIS measurements rely on the precise knowledge of the embedded oscillator which is called the Ultra Stable Oscillator (DORIS USO). The important radiations in the South Atlantic Anomaly (SAA) perturb the USO behavior by causing rapid frequency variations when the satellite is flying through the SAA. These variations are not taken into account in standard DORIS processing, since the USO is modelled as a third degree polynomial over 7-10 days. Therefore, there are systematic measurements errors when the satellite passes through SAA. In standard GNSS processing, the clock is directly estimated at each epoch. On Sentinel-3A, the GPS receiver and the DORIS receiver use the same USO. It is thus possible to estimate the behavior of the USO using GPS measurements. This estimated USO behavior can be used in the DORIS processing, instead of the third degree polynomial, hence allowing an estimation of the orbit sensitivity to these USO anomalies. This study shows two main results. First, the SAA effect on the DORIS USO is observed well using GPS measurements. Second, the USO behavior observed with GPS can be used to mitigate the SAA effect. Indeed, when used in Sentinel-3A processing, the resulting DORIS orbit shows improved phase measurements and station positioning for stations inside the SAA (Arequipa and Cachoeira). The phase measurements residuals are improved by up to 10 cm, and station vertical positioning (i.e. on the estimated Up component in the North-East-Up station frame) is improved by up to a few centimeters. However, the orbit itself is not sensitive to the correction because only two stations (out of almost 60) are SAA-sensitive on Sentinel-3A.

  6. Ultra-stable, low phase noise dielectric resonator stabilized oscillators for military and commercial systems

    NASA Technical Reports Server (NTRS)

    Mizan, Muhammad; Higgins, Thomas; Sturzebecher, Dana

    1993-01-01

    EPSD has designed, fabricated and tested, ultra-stable, low phase noise microwave dielectric resonator oscillators (DRO's) at S, X, Ku, and K-bands, for potential application to high dynamic range and low radar cross section target detection radar systems. The phase noise and the temperature stability surpass commercially available DROs. Low phase noise signals are critical for CW Doppler radars, at both very close-in and large offset frequencies from the carrier. The oscillators were built without any temperature compensation techniques and exhibited a temperature stability of 25 parts per million (ppm) over an extended temperature range. The oscillators are lightweight, small and low cost compared to BAW & SAW oscillators, and can impact commercial systems such as telecommunications, built-in-test equipment, cellular phone and satellite communications systems. The key to obtaining this performance was a high Q factor resonant structure (RS) and careful circuit design techniques. The high Q RS consists of a dielectric resonator (DR) supported by a low loss spacer inside a metal cavity. The S and the X-band resonant structures demonstrated loaded Q values of 20,300 and 12,700, respectively.

  7. Temperature, radiation and aging analysis of the DORIS Ultra Stable Oscillator by means of the Time Transfer by Laser Link experiment on Jason-2

    NASA Astrophysics Data System (ADS)

    Belli, Alexandre; Exertier, P.; Samain, E.; Courde, C.; Vernotte, F.; Jayles, C.; Auriol, A.

    2016-12-01

    The Time Transfer by Laser Link (T2L2) experiment on-board the Jason-2 satellite was launched in June 2008 at 1335 km altitude. It has been designed to use the Satellite Laser Ranging (SLR) space technique as an optical link between ground and space clocks. T2L2, as all the instruments aboard Jason-2, is referenced to the Ultra Stable Oscillator (USO) provided by the Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) system. A complex data processing has been developed in order to extract time & frequency products as the relative frequency bias of the USO from ground-to-space time transfer passages. The precision of these products was estimated of a few parts in 10-13 given the very good in-flight performance of T2L2 with a ground-to-space time stability of a few picoseconds (ps) over 100 s. Frequency bias from T2L2 were compared with results from operational orbit computation, notably with the DIODE (Détermination Immédiate d'Orbite par Doris Embarqué) outputs (see Jayles et al. (2016) same issue) at the level of 1 · 10-12. The present paper is focusing on the main physical effects which drive the frequency variations of the Jason-2 USO during its flight, notably over the South Atlantic Anomaly (SAA) area. In addition to the effects of radiation we studied the effect of the residual temperature variations, in the range 8-11 °C (measured on-board). A model was established to represent these effects on the short term with empirical coefficients (sensitivities of the USO) to be adjusted. The results of fitting the model over ∼200 10-day periods, from 2008 to 2014, show the sensitivities of the Jason-2 USO to temperature and radiation. The analysis of the 6-year output series of empirical coefficients allows us to conclude that: (i) the temperature to frequency dependence is very stable along time at the level of around -1.2 · 10-12 per °C, (ii) the radiation effects are much lower than those previously detected on the Jason-1 USO with

  8. Ultra-stable optical links for space and ground applications

    NASA Astrophysics Data System (ADS)

    Narbonneau, F.; Lours, M.; Daussy, C.; Lopez, O.; Clairon, A.; Santarelli, G.

    2017-11-01

    We have demonstrated the feasibility of a free-space ultra-stable optical link on a 3 meters test bench, operating at 100 MHz. With this type of link, it is possible to transfer a 100 MHz signal with a relative frequency stability of a few 10-14 at one second integration time, 10-16 at one day and a phase stability of a few picoseconds per day in presence of moderate mechanical vibrations and thermal fluctuations. The comparisons of modern clocks of distant (<100 km) Time and Frequency laboratories have a strong scientific interest. In this context we study a low noise frequency distribution via optical fibres. Some preliminary tests have been realized and the results are encouraging. We expect to transfer ultra stable oscillators with a relative frequency stability of a few 10-14 at one second integration time, 10-16 at one day.

  9. Ultra-stable microwave generation with a diode-pumped solid-state laser in the 1.5-μm range

    NASA Astrophysics Data System (ADS)

    Dolgovskiy, Vladimir; Schilt, Stéphane; Bucalovic, Nikola; Di Domenico, Gianni; Grop, Serge; Dubois, Benoît; Giordano, Vincent; Südmeyer, Thomas

    2014-09-01

    We demonstrate the first ultra-stable microwave generation based on a 1.5-μm diode-pumped solid-state laser (DPSSL) frequency comb. Our system relies on optical-to-microwave frequency division from a planar-waveguide external cavity laser referenced to an ultra-stable Fabry-Perot cavity. The evaluation of the microwave signal at ~10 GHz uses the transportable ultra-low-instability signal source ULISS®, which employs a cryo-cooled sapphire oscillator. With the DPSSL comb, we measured -125 dBc/Hz phase noise at 1 kHz offset frequency, likely limited by the photo-detection shot-noise or by the noise floor of the reference cryo-cooled sapphire oscillator. For comparison, we also generated low-noise microwave using a commercial Er:fiber comb stabilized in similar conditions and observed >20 dB lower phase noise in the microwave generated from the DPSSL comb. Our results confirm the high potential of the DPSSL technology for low-noise comb applications.

  10. Highly Stable Wideband Microwave Extraction by Synchronizing Widely Tunable Optoelectronic Oscillator with Optical Frequency Comb

    PubMed Central

    Hou, D.; Xie, X. P.; Zhang, Y. L.; Wu, J. T.; Chen, Z. Y.; Zhao, J. Y.

    2013-01-01

    Optical frequency combs (OFCs), based on mode-locked lasers (MLLs), have attracted considerable attention in many fields over recent years. Among the applications of OFCs, one of the most challenging works is the extraction of a highly stable microwave with low phase noise. Many synchronisation schemes have been exploited to synchronise an electronic oscillator with the pulse train from a MLL, helping to extract an ultra-stable microwave. Here, we demonstrate novel wideband microwave extraction from a stable OFC by synchronising a single widely tunable optoelectronic oscillator (OEO) with an OFC at different harmonic frequencies, using an optical phase detection technique. The tunable range of the proposed microwave extraction extends from 2 GHz to 4 GHz, and in a long-term synchronisation experiment over 12 hours, the proposed synchronisation scheme provided a rms timing drift of 18 fs and frequency instabilities at 1.2 × 10−15/1 s and 2.2 × 10−18/10000 s. PMID:24336459

  11. Highly Stable Wideband Microwave Extraction by Synchronizing Widely Tunable Optoelectronic Oscillator with Optical Frequency Comb

    NASA Astrophysics Data System (ADS)

    Hou, D.; Xie, X. P.; Zhang, Y. L.; Wu, J. T.; Chen, Z. Y.; Zhao, J. Y.

    2013-12-01

    Optical frequency combs (OFCs), based on mode-locked lasers (MLLs), have attracted considerable attention in many fields over recent years. Among the applications of OFCs, one of the most challenging works is the extraction of a highly stable microwave with low phase noise. Many synchronisation schemes have been exploited to synchronise an electronic oscillator with the pulse train from a MLL, helping to extract an ultra-stable microwave. Here, we demonstrate novel wideband microwave extraction from a stable OFC by synchronising a single widely tunable optoelectronic oscillator (OEO) with an OFC at different harmonic frequencies, using an optical phase detection technique. The tunable range of the proposed microwave extraction extends from 2 GHz to 4 GHz, and in a long-term synchronisation experiment over 12 hours, the proposed synchronisation scheme provided a rms timing drift of 18 fs and frequency instabilities at 1.2 × 10-15/1 s and 2.2 × 10-18/10000 s.

  12. Membrane Resonance Enables Stable and Robust Gamma Oscillations

    PubMed Central

    Moca, Vasile V.; Nikolić, Danko; Singer, Wolf; Mureşan, Raul C.

    2014-01-01

    Neuronal mechanisms underlying beta/gamma oscillations (20–80 Hz) are not completely understood. Here, we show that in vivo beta/gamma oscillations in the cat visual cortex sometimes exhibit remarkably stable frequency even when inputs fluctuate dramatically. Enhanced frequency stability is associated with stronger oscillations measured in individual units and larger power in the local field potential. Simulations of neuronal circuitry demonstrate that membrane properties of inhibitory interneurons strongly determine the characteristics of emergent oscillations. Exploration of networks containing either integrator or resonator inhibitory interneurons revealed that: (i) Resonance, as opposed to integration, promotes robust oscillations with large power and stable frequency via a mechanism called RING (Resonance INduced Gamma); resonance favors synchronization by reducing phase delays between interneurons and imposes bounds on oscillation cycle duration; (ii) Stability of frequency and robustness of the oscillation also depend on the relative timing of excitatory and inhibitory volleys within the oscillation cycle; (iii) RING can reproduce characteristics of both Pyramidal INterneuron Gamma (PING) and INterneuron Gamma (ING), transcending such classifications; (iv) In RING, robust gamma oscillations are promoted by slow but are impaired by fast inputs. Results suggest that interneuronal membrane resonance can be an important ingredient for generation of robust gamma oscillations having stable frequency. PMID:23042733

  13. Coupled opto-electronic oscillator

    NASA Technical Reports Server (NTRS)

    Yao, X. Steve (Inventor); Maleki, Lute (Inventor)

    1999-01-01

    A coupled opto-electronic oscillator that directly couples a laser oscillation with an electronic oscillation to simultaneously achieve a stable RF oscillation at a high frequency and ultra-short optical pulsation by mode locking with a high repetition rate and stability. Single-mode selection can be achieved even with a very long opto-electronic loop. A multimode laser can be used to pump the electronic oscillation, resulting in a high operation efficiency. The optical and the RF oscillations are correlated to each other.

  14. Modeling Bloch oscillations in ultra-small Josephson junctions

    NASA Astrophysics Data System (ADS)

    Vora, Heli; Kautz, Richard; Nam, Sae Woo; Aumentado, Jose

    In a seminal paper, Likharev et al. developed a theory for ultra-small Josephson junctions with Josephson coupling energy (Ej) less than the charging energy (Ec) and showed that such junctions demonstrate Bloch oscillations which could be used to make a fundamental current standard that is a dual of the Josephson volt standard. Here, based on the model of Geigenmüller and Schön, we numerically calculate the current-voltage relationship of such an ultra-small junction which includes various error processes present in a nanoscale Josephson junction such as random quasiparticle tunneling events and Zener tunneling between bands. This model allows us to explore the parameter space to see the effect of each process on the width and height of the Bloch step and serves as a guide to determine whether it is possible to build a quantum current standard of a metrological precision using Bloch oscillations.

  15. Design and progress report for compact cryocooled sapphire oscillator 'VCSO'

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Wang, Rabi T.; Tjoelker, Robert L.

    2005-01-01

    We report on the development of a compact cryocooled sapphiere oscillator 'VCSO', designed as a higher-performance replacement for ultra-stable quartz oscillators in local oscillator, cleanup, and flywheel applications in the frequency generation and distribution subsystems of NASA's Deep Space Network (DSN).

  16. Next Generation JPL Ultra-Stable Trapped Ion Atomic Clocks

    NASA Technical Reports Server (NTRS)

    Burt, Eric; Tucker, Blake; Larsen, Kameron; Hamell, Robert; Tjoelker, Robert

    2013-01-01

    Over the past decade, trapped ion atomic clock development at the Jet Propulsion Laboratory (JPL) has focused on two directions: 1) new atomic clock technology for space flight applications that require strict adherence to size, weight, and power requirements, and 2) ultra-stable atomic clocks, usually for terrestrial applications emphasizing ultimate performance. In this paper we present a new ultra-stable trapped ion clock designed, built, and tested in the second category. The first new standard, L10, will be delivered to the Naval Research Laboratory for use in characterizing DoD space clocks.

  17. Switchable genetic oscillator operating in quasi-stable mode

    PubMed Central

    Strelkowa, Natalja; Barahona, Mauricio

    2010-01-01

    Ring topologies of repressing genes have qualitatively different long-term dynamics if the number of genes is odd (they oscillate) or even (they exhibit bistability). However, these attractors may not fully explain the observed behaviour in transient and stochastic environments such as the cell. We show here that even repressilators possess quasi-stable, travelling wave periodic solutions that are reachable, long-lived and robust to parameter changes. These solutions underlie the sustained oscillations observed in even rings in the stochastic regime, even if these circuits are expected to behave as switches. The existence of such solutions can also be exploited for control purposes: operation of the system around the quasi-stable orbit allows us to turn on and off the oscillations reliably and on demand. We illustrate these ideas with a simple protocol based on optical interference that can induce oscillations robustly both in the stochastic and deterministic regimes. PMID:20097721

  18. Enhancing the Art of Space Operations - Progress in JHU/APL Ultra-Stable Oscillator Capabilities

    DTIC Science & Technology

    2008-12-01

    solution for robust extraterrestrial clocks with an operational life requirement greater than 10 years. Disciplined USO systems could be placed in very...USO) has been demonstrated in nearly 50 years of space applications to be a strategic asset to the space timekeeping and signal technologies of the...while also providing flight USO hardware to missions such as the NASA Gravity Recovery and Climate Experiment (GRACE) and JHU/APL’s New Horizons

  19. Stable amplitude chimera states in a network of locally coupled Stuart-Landau oscillators.

    PubMed

    Premalatha, K; Chandrasekar, V K; Senthilvelan, M; Lakshmanan, M

    2018-03-01

    We investigate the occurrence of collective dynamical states such as transient amplitude chimera, stable amplitude chimera, and imperfect breathing chimera states in a locally coupled network of Stuart-Landau oscillators. In an imperfect breathing chimera state, the synchronized group of oscillators exhibits oscillations with large amplitudes, while the desynchronized group of oscillators oscillates with small amplitudes, and this behavior of coexistence of synchronized and desynchronized oscillations fluctuates with time. Then, we analyze the stability of the amplitude chimera states under various circumstances, including variations in system parameters and coupling strength, and perturbations in the initial states of the oscillators. For an increase in the value of the system parameter, namely, the nonisochronicity parameter, the transient chimera state becomes a stable chimera state for a sufficiently large value of coupling strength. In addition, we also analyze the stability of these states by perturbing the initial states of the oscillators. We find that while a small perturbation allows one to perturb a large number of oscillators resulting in a stable amplitude chimera state, a large perturbation allows one to perturb a small number of oscillators to get a stable amplitude chimera state. We also find the stability of the transient and stable amplitude chimera states and traveling wave states for an appropriate number of oscillators using Floquet theory. In addition, we also find the stability of the incoherent oscillation death states.

  20. Stable amplitude chimera states in a network of locally coupled Stuart-Landau oscillators

    NASA Astrophysics Data System (ADS)

    Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2018-03-01

    We investigate the occurrence of collective dynamical states such as transient amplitude chimera, stable amplitude chimera, and imperfect breathing chimera states in a locally coupled network of Stuart-Landau oscillators. In an imperfect breathing chimera state, the synchronized group of oscillators exhibits oscillations with large amplitudes, while the desynchronized group of oscillators oscillates with small amplitudes, and this behavior of coexistence of synchronized and desynchronized oscillations fluctuates with time. Then, we analyze the stability of the amplitude chimera states under various circumstances, including variations in system parameters and coupling strength, and perturbations in the initial states of the oscillators. For an increase in the value of the system parameter, namely, the nonisochronicity parameter, the transient chimera state becomes a stable chimera state for a sufficiently large value of coupling strength. In addition, we also analyze the stability of these states by perturbing the initial states of the oscillators. We find that while a small perturbation allows one to perturb a large number of oscillators resulting in a stable amplitude chimera state, a large perturbation allows one to perturb a small number of oscillators to get a stable amplitude chimera state. We also find the stability of the transient and stable amplitude chimera states and traveling wave states for an appropriate number of oscillators using Floquet theory. In addition, we also find the stability of the incoherent oscillation death states.

  1. Coupled Optoelectronic Oscillators:. Application to Low-Jitter Pulse Generation

    NASA Astrophysics Data System (ADS)

    Yu, N.; Tu, M.; Maleki, L.

    2002-04-01

    Actively mode-locked Erbium-doped fiber lasers (EDFL) have been studied for generating stable ultra-fast pulses (< 2 ps) at high repetition rates (> 5 GHz) [1,2]. These devices can be compact and environmentally stable, quite suitable for fiber-based high-data-rate communications and optical ultra-fast analog-to-digital conversions (ADC) [3]. The pulse-to-pulse jitter of an EDFL-based pulse generator will be ultimately limited by the phase noise of the mode-locking microwave source (typically electronic frequency synthesizers). On the other hand, opto-electronic oscillators (OEO) using fibers have been demonstrated to generate ultra-low phase noise microwaves at 10 GHz and higher [4]. The overall phase noise of an OEO can be much lower than commercially available synthesizers at the offset-frequency range above 100 Hz. Clearly, ultra-low jitter pulses can be generated by taking advantage of the low phase noise of OEOs. In this paper, we report the progress in developing a new low-jitter pulse generator by combing the two technologies. In our approach, the optical oscillator (mode-locked EDFL) and the microwave oscillator (OEO) are coupled through a common Mach-Zehnder (MZ) modulator, thus named coupled opto-electronic oscillator (COEO) [5]. Based on the results of previous OEO study, we can expect a 10 GHz pulse train with jitters less than 10 fs.

  2. Ultra-stable high average power femtosecond laser system tunable from 1.33 to 20  μm.

    PubMed

    Steinle, Tobias; Mörz, Florian; Steinmann, Andy; Giessen, Harald

    2016-11-01

    A highly stable 350 fs laser system with a gap-free tunability from 1.33 to 2.0 μm and 2.13 to 20 μm is demonstrated. Nanojoule-level pulse energy is achieved in the mid-infrared at a 43 MHz repetition rate. The system utilizes a post-amplified fiber-feedback optical parametric oscillator followed by difference frequency generation between the signal and idler. No locking or synchronization electronics are required to achieve outstanding free-running output power and spectral stability of the whole system. Ultra-low intensity noise, close to the pump laser's noise figure, enables shot-noise limited measurements.

  3. Wideband tunable optoelectronic oscillator based on a microwave photonic filter with an ultra-narrow passband.

    PubMed

    Tang, Haitao; Yu, Yuan; Wang, Ziwei; Xu, Lu; Zhang, Xinliang

    2018-05-15

    A novel wideband tunable optoelectronic oscillator based on a microwave photonic filter (MPF) with an ultra-narrow passband is proposed and experimentally demonstrated. The single-passband MPF is realized by cascading an MPF based on stimulated Brillouin scattering and an infinite impulse response (IIR) MPF based on an active fiber recirculating delay loop. The measured full width at half-maximum bandwidth of the cascaded MPFs is 150 kHz. To the best of my knowledge, this is the first time realizing such a narrow passband in single-passband MPF. The oscillation frequency of the OEO can be tuned from 0 to 40 GHz owing to the wideband tunability of the MPF. Thanks to the ultrahigh mode selectivity of the IIR filter, the mode hopping is successfully suppressed. A stable microwave signal at 8.18 GHz is obtained with a phase noise of -113  dBc/Hz at 10 kHz, and the side mode noise is below -95  dBc/Hz. The signal-to-noise ratio exceeds 50 dB during the tuning process.

  4. Ultra-Broad-Band Optical Parametric Amplifier or Oscillator

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatolly; Maleki, Lute

    2009-01-01

    A concept for an ultra-broad-band optical parametric amplifier or oscillator has emerged as a by-product of a theoretical study in fundamental quantum optics. The study was originally intended to address the question of whether the two-photon temporal correlation function of light [in particular, light produced by spontaneous parametric down conversion (SPDC)] can be considerably narrower than the inverse of the spectral width (bandwidth) of the light. The answer to the question was found to be negative. More specifically, on the basis of the universal integral relations between the quantum two-photon temporal correlation and the classical spectrum of light, it was found that the lower limit of two-photon correlation time is set approximately by the inverse of the bandwidth. The mathematical solution for the minimum two-photon correlation time also provides the minimum relative frequency dispersion of the down-converted light components; in turn, the minimum relative frequency dispersion translates to the maximum bandwidth, which is important for the design of an ultra-broad-band optical parametric oscillator or amplifier. In the study, results of an analysis of the general integral relations were applied in the case of an optically nonlinear, frequency-dispersive crystal in which SPDC produces collinear photons. Equations were found for the crystal orientation and pump wavelength, specific for each parametric-down-converting crystal, that eliminate the relative frequency dispersion of collinear degenerate (equal-frequency) signal and idler components up to the fourth order in the frequency-detuning parameter

  5. Environmentally stable all-PM all-fiber giant chirp oscillator.

    PubMed

    Erkintalo, Miro; Aguergaray, Claude; Runge, Antoine; Broderick, Neil G R

    2012-09-24

    We report on an environmentally stable giant chirp oscillator operating at 1030 nm. Thanks to the use of a nonlinear amplifying loop mirror as the mode-locker, we are able to extract pulse energies in excess of 10 nJ from a robust all-PM cavity with no free-space elements. Extensive numerical simulations reveal that the output oscillator energy and duration can simply be up-scaled through the lengthening of the cavity with suitably positioned single-mode fiber. Experimentally, using different cavity lengths we have achieved environmentally stable mode-locking at 10, 3.7 and 1.7 MHz with corresponding pulse energies of 2.3, 10 and 16 nJ. In all cases external grating-pair compression below 400 fs has been demonstrated.

  6. Self-organisation of random oscillators with Lévy stable distributions

    NASA Astrophysics Data System (ADS)

    Moradi, Sara; Anderson, Johan

    2017-08-01

    A novel possibility of self-organized behaviour of stochastically driven oscillators is presented. It is shown that synchronization by Lévy stable processes is significantly more efficient than that by oscillators with Gaussian statistics. The impact of outlier events from the tail of the distribution function was examined by artificially introducing a few additional oscillators with very strong coupling strengths and it is found that remarkably even one such rare and extreme event may govern the long term behaviour of the coupled system. In addition to the multiplicative noise component, we have investigated the impact of an external additive Lévy distributed noise component on the synchronisation properties of the oscillators.

  7. Characterization of electrical noise limits in ultra-stable laser systems.

    PubMed

    Zhang, J; Shi, X H; Zeng, X Y; Lü, X L; Deng, K; Lu, Z H

    2016-12-01

    We demonstrate thermal noise limited and shot noise limited performance of ultra-stable diode laser systems. The measured heterodyne beat linewidth between such two independent diode lasers reaches 0.74 Hz. The frequency instability of one single laser approaches 1.0 × 10 -15 for averaging time between 0.3 s and 10 s, which is close to the thermal noise limit of the reference cavity. Taking advantage of these two ultra-stable laser systems, we systematically investigate the ultimate electrical noise contributions, and derive expressions for the closed-loop spectral density of laser frequency noise. The measured power spectral density of the beat frequency is compared with the theoretically calculated closed-loop spectral density of the laser frequency noise, and they agree very well. It illustrates the power and generality of the derived closed-loop spectral density formula of the laser frequency noise. Our result demonstrates that a 10 -17 level locking in a wide frequency range is feasible with careful design.

  8. Ultra-broadband tunable (0.67-2.57 µm) optical vortex parametric oscillator

    NASA Astrophysics Data System (ADS)

    Araki, Shungo; Suzuki, Kensuke; Nishida, Shigeki; Mamuti, Roukuya; Miyamoto, Katsuhiko; Omatsu, Takashige

    2017-10-01

    We demonstrate an ultra-broadband (>2-octave band) tunable optical vortex laser comprising an optical-vortex-pumped optical parametric oscillator by employing a nanosecond pulse (˜10 ns) green laser and cascaded non-critical phase-matching LiB3O5 crystals (45 mm long each). With this system, an optical vortex output was produced over an extremely wide wavelength range of 0.67-2.57 µm.

  9. Stable integrated hyper-parametric oscillator based on coupled optical microcavities.

    PubMed

    Armaroli, Andrea; Feron, Patrice; Dumeige, Yannick

    2015-12-01

    We propose a flexible scheme based on three coupled optical microcavities that permits us to achieve stable oscillations in the microwave range, the frequency of which depends only on the cavity coupling rates. We find that the different dynamical regimes (soft and hard excitation) affect the oscillation intensity, but not their periods. This configuration may permit us to implement compact hyper-parametric sources on an integrated optical circuit with interesting applications in communications, sensing, and metrology.

  10. The Performance of Ultra-stable Oscillators for the Gravity Recovery and Interior Laboratory (GRAIL)

    DTIC Science & Technology

    2010-11-01

    the mid-2000s for JHU/APL’s exploration mission of Pluto and the Kuiper belt . Fig. 1. Timeline of USO mission legacy with history of...determination at remote bodies far from Earth extends the possibility of measuring other moons, planets, and asteroids in future science mission concepts

  11. NICER Discovers mHz Oscillations and Marginally Stable Burning in GS 1826-24

    NASA Astrophysics Data System (ADS)

    Strohmayer, Tod E.; Gendreau, Keith C.; Keek, Laurens; Bult, Peter; Mahmoodifar, Simin; Chakrabarty, Deepto; Arzoumanian, Zaven; NICER Science Team

    2018-01-01

    To date, marginally stable thermonuclear burning, evidenced as mHz X-ray flux oscillations, has been observed in only five accreting neutron star binaries, 4U 1636-536, 4U 1608-52, Aql X-1, 4U 1323-619 and Terzan 5 X-2. Here we report the discovery with NASA's Neutron Star Interior Composition Explorer (NICER) of such oscillations from the well-known X-ray burster GS 1826-24. NICER observed GS 1826-24 on 9 September, 2017 for a total exposure of about 4 ksec. Timing analysis revealed highly significant oscillations at a frequency of 8.2 mHz in two successive pointings. The oscillations have a fractional modulation amplitude of approximately 3% for photon energies less than 6 keV. The observed frequency is consistent with the range observed in the other mHz QPO systems, and indeed is slightly higher than the frequency measured in 4U 1636-536 below which mHz oscillations ceased and unstable burning (X-ray bursts) resumed. We discuss the mass accretion rate dependence of the oscillations as well as the X-ray spectrum as a function of pulsation phase. We place the observations in the context of the current theory of marginally stable burning and briefly discuss the potential for constraining neutron star properties using mHz oscillations.

  12. Comparison of the frequency estimation of the DORIS/Jason2 oscillator thanks to the onboard DIODE and Time Transfer by Laser Link experiment

    NASA Astrophysics Data System (ADS)

    Jayles, C.; Exertier, P.; Martin, N.; Chauveau, J. P.; Samain, E.; Tourain, C.; Auriol, A.; Guillemot, P.

    2016-12-01

    The main applications for DORIS are precise orbit determination, and precise Geodesy. Onboard Jason-2 for instance, the DORIS tracking component is the French contribution to the precise orbit determination capability, a key capability for altimetry product scientific result accuracy. T2L2 is a time transfer technique based on the propagation of light pulses for synchronization between two clocks. Hosting T2L2 on-board Jason-2 was to allow for very fine DORIS USO (Ultra-Stable Oscillator) frequency monitoring, and for this purpose T2L2 was connected to the DORIS USO. Thanks to the continuous tracking of T2L2/Jason-2 by the Laser Ranging network it is possible to monitor the USO for several days, weeks, and even much longer, and thus to also compare with the DIODE (the DORIS on-board orbit determination software) frequency bias estimates. The DORIS USO frequency biases estimate comparison between two independent systems, T2L2 and DIODE, can be of benefit to both, allowing the accuracies of both systems to be better understood, and for improvements to be made to both systems. Such comparison is the central topic of the present paper. T2L2 monitors the DORIS on-board USO frequency with an accuracy of much better than 10-12 which is the specification for the Doppler instrumentation. The paper investigates the limits of the DORIS-DIODE frequency bias estimates using T2L2, showing that USO frequency compliance accuracy of 10-12 has been reached.

  13. Dynamics of glass-forming liquids. XV. Dynamical features of molecular liquids that form ultra-stable glasses by vapor deposition

    NASA Astrophysics Data System (ADS)

    Chen, Zhen; Richert, Ranko

    2011-09-01

    The dielectric relaxation behavior of ethylbenzene (EBZ) in its viscous regime is measured, and the glass transition temperature (Tg = 116 K) as well as fragility (m = 98) are determined. While the Tg of EBZ from this work is consistent with earlier results, the fragility is found much higher than what has been assumed previously. Literature data is supplemented by the present results on EBZ to compile the dynamic behavior of those glass formers that are known to form ultra-stable glasses by vapor deposition. These dynamics are contrasted with those of ethylcyclohexane, a glass former for which a comparable vapor deposition failed to produce an equally stable glassy state. In a graph that linearizes Vogel-Fulcher-Tammann behavior, i.e., the derivative of -logτ with respect to T/Tg raised to the power of -1/2 versus T/Tg, all ultra-stable glass formers fall onto one master curve in a wide temperature range, while ethylcyclohexane deviates for T ≫ Tg. This result suggests that ultra-stable glass formers share common behavior regarding the dynamics of their supercooled liquid state if scaled to their respective Tg values, and that fragility and related features are linked to the ability to form ultra-stable materials.

  14. An ultra-stable voltage source for precision Penning-trap experiments

    NASA Astrophysics Data System (ADS)

    Böhm, Ch.; Sturm, S.; Rischka, A.; Dörr, A.; Eliseev, S.; Goncharov, M.; Höcker, M.; Ketter, J.; Köhler, F.; Marschall, D.; Martin, J.; Obieglo, D.; Repp, J.; Roux, C.; Schüssler, R. X.; Steigleder, M.; Streubel, S.; Wagner, Th.; Westermann, J.; Wieder, V.; Zirpel, R.; Melcher, J.; Blaum, K.

    2016-08-01

    An ultra-stable and low-noise 25-channel voltage source providing 0 to -100 V has been developed. It will supply stable bias potentials for Penning-trap electrodes used in high-precision experiments. The voltage source generates all its supply voltages via a specially designed transformer. Each channel can be operated either in a precision mode or can be dynamically ramped. A reference module provides reference voltages for all the channels, each of which includes a low-noise amplifier to gain a factor of 10 in the output stage. A relative voltage stability of δV / V ≈ 2 ×10-8 has been demonstrated at -89 V within about 10 min.

  15. Optical distribution of local oscillators in future telecommunication satellite payloads

    NASA Astrophysics Data System (ADS)

    Benazet, Benoît; Sotom, Michel; Maignan, Michel; Berthon, Jacques

    2017-11-01

    The distribution of high spectral purity reference signals over optical fibre in future telecommunication satellite payloads is presented. Several types of applications are considered, including the distribution of a reference frequency at 10 MHz (Ultra-Stable Reference Oscillator) as well as the distribution of a radiofrequency oscillator around 800 MHz (Master Local Oscillator). The results of both experimental and theoretical studies are reported. In order to meet phase noise requirements for the USRO distribution, the use of an optimised receiver circuit based on an optically synchronised oscillator is investigated. Finally, the optical distribution of microwave local oscillators at frequencies exceeding 20 GHz is described. Such a scheme paves the way to more advanced sub-systems involving optical frequency-mixing and optical transmission of microwave signals, with applications to multiple-beam active antennas.

  16. An improved offset generator developed for Allan deviation measurement of ultra stable frequency standards

    NASA Technical Reports Server (NTRS)

    Hamell, Robert L.; Kuhnle, Paul F.; Sydnor, Richard L.

    1992-01-01

    Measuring the performance of ultra stable frequency standards such as the Superconducting Cavity Maser Oscillator (SCMO) necessitates improvement of some test instrumentation. The frequency stability test equipment used at JPL includes a 1 Hz Offset Generator to generate a beat frequency between a pair of 100 MHz signals that are being compared. The noise floor of the measurement system using the current Offset Generator is adequate to characterize stability of hydrogen masers, but it is not adequate for the SCMO. A new Offset Generator with improved stability was designed and tested at JPL. With this Offset Generator and a new Zero Crossing Detector, recently developed at JPL, the measurement flow was reduced by a factor of 5.5 at 1 second tau, 3.0 at 1000 seconds, and 9.4 at 10,000 seconds, compared against the previous design. In addition to the new circuit designs of the Offset Generator and Zero Crossing Detector, tighter control of the measurement equipment environment was required to achieve this improvement. The design of this new Offset Generator are described, along with details of the environment control methods used.

  17. Ultra-Stable Segmented Telescope Sensing and Control Architecture

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee; Bolcar, Matthew; Knight, Scott; Redding, David

    2017-01-01

    The LUVOIR team is conducting two full architecture studies Architecture A 15 meter telescope that folds up in an 8.4m SLS Block 2 shroud is nearly complete. Architecture B 9.2 meter that uses an existing fairing size will begin study this Fall. This talk will summarize the ultra-stable architecture of the 15m segmented telescope including the basic requirements, the basic rationale for the architecture, the technologies employed, and the expected performance. This work builds on several dynamics and thermal studies performed for ATLAST segmented telescope configurations. The most important new element was an approach to actively control segments for segment to segment motions which will be discussed later.

  18. Sensitivity of Magnetospheric Multi-Scale (MMS) Mission Navigation Accuracy to Major Error Sources

    NASA Technical Reports Server (NTRS)

    Olson, Corwin; Long, Anne; Car[emter. Russell

    2011-01-01

    The Magnetospheric Multiscale (MMS) mission consists of four satellites flying in formation in highly elliptical orbits about the Earth, with a primary objective of studying magnetic reconnection. The baseline navigation concept is independent estimation of each spacecraft state using GPS pseudorange measurements referenced to an Ultra Stable Oscillator (USO) with accelerometer measurements included during maneuvers. MMS state estimation is performed onboard each spacecraft using the Goddard Enhanced Onboard Navigation System (GEONS), which is embedded in the Navigator GPS receiver. This paper describes the sensitivity of MMS navigation performance to two major error sources: USO clock errors and thrust acceleration knowledge errors.

  19. Sensitivity of Magnetospheric Multi-Scale (MMS) Mission Naviation Accuracy to Major Error Sources

    NASA Technical Reports Server (NTRS)

    Olson, Corwin; Long, Anne; Carpenter, J. Russell

    2011-01-01

    The Magnetospheric Multiscale (MMS) mission consists of four satellites flying in formation in highly elliptical orbits about the Earth, with a primary objective of studying magnetic reconnection. The baseline navigation concept is independent estimation of each spacecraft state using GPS pseudorange measurements referenced to an Ultra Stable Oscillator (USO) with accelerometer measurements included during maneuvers. MMS state estimation is performed onboard each spacecraft using the Goddard Enhanced Onboard Navigation System (GEONS), which is embedded in the Navigator GPS receiver. This paper describes the sensitivity of MMS navigation performance to two major error sources: USO clock errors and thrust acceleration knowledge errors.

  20. Atomic fountain clock with very high frequency stability employing a pulse-tube-cryocooled sapphire oscillator.

    PubMed

    Takamizawa, Akifumi; Yanagimachi, Shinya; Tanabe, Takehiko; Hagimoto, Ken; Hirano, Iku; Watabe, Ken-ichi; Ikegami, Takeshi; Hartnett, John G

    2014-09-01

    The frequency stability of an atomic fountain clock was significantly improved by employing an ultra-stable local oscillator and increasing the number of atoms detected after the Ramsey interrogation, resulting in a measured Allan deviation of 8.3 × 10(-14)τ(-1/2)). A cryogenic sapphire oscillator using an ultra-low-vibration pulse-tube cryocooler and cryostat, without the need for refilling with liquid helium, was applied as a local oscillator and a frequency reference. High atom number was achieved by the high power of the cooling laser beams and optical pumping to the Zeeman sublevel m(F) = 0 employed for a frequency measurement, although vapor-loaded optical molasses with the simple (001) configuration was used for the atomic fountain clock. The resulting stability is not limited by the Dick effect as it is when a BVA quartz oscillator is used as the local oscillator. The stability reached the quantum projection noise limit to within 11%. Using a combination of a cryocooled sapphire oscillator and techniques to enhance the atom number, the frequency stability of any atomic fountain clock, already established as primary frequency standard, may be improved without opening its vacuum chamber.

  1. Stable And Oscillating Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  2. Thermal design and test results for SUNLITE ultra-stable reference cavity

    NASA Technical Reports Server (NTRS)

    Amundsen, Ruth M.

    1991-01-01

    SUNLITE (Stanford University-NASA Laser In-Space Technology Experiment) is a space-based experiment which uses a reference cavity to provide a stable frequency reference for a terahertz laser oscillator. Thermal stability of the cavity is a key factor in attaining a stable narrow-linewidth laser beam. The mount which is used to support and align the cavity will provide thermal isolation from the environment. The baseline requirement for thermal stability of the cavity is 0.025 C/min, but the design is directed toward achieving stability well beyond this requirement to improve the science data gained. A prototype of the cavity mount was fabricated and tested to characterize the thermal performance. The thermal vacuum test involved stable high-resolution temperature measurements and stable baseplate temperature control over long durations. Based on test data, the cavity mount design satisfies the severe requirement for the cavity thermal stability.

  3. Chaotic ultra-wideband radio generator based on an optoelectronic oscillator with a built-in microwave photonic filter.

    PubMed

    Wang, Li Xian; Zhu, Ning Hua; Zheng, Jian Yu; Liu, Jian Guo; Li, Wei

    2012-05-20

    We induce a microwave photonic bandpass filter into an optoelectronic oscillator to generate a chaotic ultra-wideband signal in both the optical and electrical domain. The theoretical analysis and numerical simulation indicate that this system is capable of generating band-limited high-dimensional chaos. Experimental results coincide well with the theoretical prediction and show that the power spectrum of the generated chaotic signal basically meets the Federal Communications Commission indoor mask. The generated chaotic carrier is further intensity modulated by a 10 MHz square wave, and the waveform of the output ultra-wideband signal is measured for demonstrating the chaotic on-off keying modulation.

  4. Ultra Small Aperture Terminal: System Design and Test Results

    NASA Technical Reports Server (NTRS)

    Sohn, Philip Y.; Reinhart, Richard C.

    1996-01-01

    The Ultra Small Aperture Terminal (USAT) has been developed to test and demonstrate remote and broadcast satcom applications via the Advanced Communications Technology Satellite (ACTS). The design of these ground stations emphasize small size, low power consumption, portable and rugged terminals. Each ground station includes several custom design parts such as 35 cm diameter antenna, 1/4 Watt transmitter with built-in upconverter, and 4.0 dB Noise Figure (NF) receiver with built-in downconverter. In addition, state-of-the-art commercial parts such as highly stable ovenized crystal oscillators and dielectric resonator oscillators are used in the ground station design. Presented in this paper are system level design description, performance, and sample applications.

  5. In-situ precipitation of ultra-stable nano-magnetite slurry

    NASA Astrophysics Data System (ADS)

    Ramimoghadam, Donya; Bagheri, Samira; Hamid, Sharifah Bee Abd

    2015-04-01

    In this contribution, we prepared water-based magnetic fluids of iron oxide nanoparticles using an in-situ precipitation method. The effect of dodecanoic acid addition as a surfactant on the physico-chemical and magnetic properties of iron oxide nanoparticles was investigated as well. The quantity of the surfactant was varied between 3 and 5 g. Raman spectroscopy and X-ray diffraction (XRD) were utilized to confirm the presence of spinel phase magnetites (Fe3O4). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to characterize the resulting magnetic nanoparticles' size and morphology. The results showed polydispersed hexagonal nanoparticles (average diameter of ca. 70 nm) as a result of the protocol. Moreover, the pH-dependent stability of the samples confirms that magnetite nanofluids were highly stable in the wide range of pH, from 4-12. The optimal amount of dodecanoic acid to produce ultra-stable nano-magnetite slurry with the highest saturation magnetization of 8.6 emu g-1 was determined to be 4.5 g.

  6. Functionalizable and ultra stable nanoparticles coated with zwitterionic poly(carboxybetaine) in undiluted blood serum.

    PubMed

    Yang, Wei; Zhang, Lei; Wang, Shanlin; White, Andrew D; Jiang, Shaoyi

    2009-10-01

    A new surface chemistry presenting an abundance of functional groups for ligand immobilization in an ultra-low fouling background all in one material for nanoparticles was introduced. This surface platform, as demonstrated by zwitterionic poly(carboxybetaine acrylamide) (polyCBAA) coated nanoparticles, is not only ultra stable in undiluted human blood serum, but also can be conjugated to biomolecules conveniently and effectively. Thus, this surface chemistry is ideal to create multi-functional nanoparticles for targeted delivery and diagnostics. In addition, this work clearly shows that 10% blood serum commonly used to evaluate the stability of nanoparticles is insufficient and a new evaluation criterion with undiluted blood serum is recommended.

  7. Neuronal oscillations on an ultra-slow timescale: daily rhythms in electrical activity and gene expression in the mammalian master circadian clockwork.

    PubMed

    Belle, Mino D C; Diekman, Casey O

    2018-02-03

    Neuronal oscillations of the brain, such as those observed in the cortices and hippocampi of behaving animals and humans, span across wide frequency bands, from slow delta waves (0.1 Hz) to ultra-fast ripples (600 Hz). Here, we focus on ultra-slow neuronal oscillators in the hypothalamic suprachiasmatic nuclei (SCN), the master daily clock that operates on interlocking transcription-translation feedback loops to produce circadian rhythms in clock gene expression with a period of near 24 h (< 0.001 Hz). This intracellular molecular clock interacts with the cell's membrane through poorly understood mechanisms to drive the daily pattern in the electrical excitability of SCN neurons, exhibiting an up-state during the day and a down-state at night. In turn, the membrane activity feeds back to regulate the oscillatory activity of clock gene programs. In this review, we emphasise the circadian processes that drive daily electrical oscillations in SCN neurons, and highlight how mathematical modelling contributes to our increasing understanding of circadian rhythm generation, synchronisation and communication within this hypothalamic region and across other brain circuits. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  8. Measurement of ultra-low power oscillators using adaptive drift cancellation with applications to nano-magnetic spin torque oscillators.

    PubMed

    Tamaru, S; Ricketts, D S

    2013-05-01

    This work presents a technique for measuring ultra-low power oscillator signals using an adaptive drift cancellation method. We demonstrate this technique through spectrum measurements of a sub-pW nano-magnet spin torque oscillator (STO). We first present a detailed noise analysis of the standard STO characterization apparatus to estimate the background noise level, then compare these results to the noise level of three measurement configurations. The first and second share the standard configuration but use different spectrum analyzers (SA), an older model and a state-of-the-art model, respectively. The third is the technique proposed in this work using the same old SA as for the first. Our results show that the first and second configurations suffer from a large drift that requires ~30 min to stabilize each time the SA changes the frequency band, even though the SA has been powered on for longer than 24 h. The third configuration introduced in this work, however, shows absolutely no drift as the SA changes frequency band, and nearly the same noise performance as with a state-of-the-art SA, thus providing a reliable method for measuring very low power signals for a wide variety of applications.

  9. Study of plasma-based stable and ultra-wideband electromagnetic wave absorption for stealth application

    NASA Astrophysics Data System (ADS)

    Xuyang, CHEN; Fangfang, SHEN; Yanming, LIU; Wei, AI; Xiaoping, LI

    2018-06-01

    A plasma-based stable, ultra-wideband electromagnetic (EM) wave absorber structure is studied in this paper for stealth applications. The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately. The plasma in each plasma layer is designed to be uniform, whereas it has a discrete nonuniform distribution from the overall view of the structure. The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption. A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers, by which the wave absorption range is extended to the ultra-wideband. Then, the scattering matrix method (SMM) is employed to analyze the electromagnetic reflection and absorption of the absorber structure. In the simulation, the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case. Then, the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail, verifying the EM wave absorption performance of the absorber. The proposed structure and model are expected to be superior in some realistic applications, such as supersonic aircraft.

  10. The In-Flight Frequency Behavior of Two Ultra-Stable Oscillators Onboard the New Horizons Spacecraft

    DTIC Science & Technology

    2007-11-01

    the other is maintained in a “warm-boot” backup mode. The implementation of the transceiver for noncoherent navigation provides the opportunity for...frequency reference for the REX (Radio science Experiment) instrument and the master oscillator for the communications transceiver and the noncoherent ...byproduct of noncoherent Doppler based 79 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information

  11. Breaking the limitation of mode building time in an optoelectronic oscillator.

    PubMed

    Hao, Tengfei; Cen, Qizhuang; Dai, Yitang; Tang, Jian; Li, Wei; Yao, Jianping; Zhu, Ninghua; Li, Ming

    2018-05-09

    An optoelectronic oscillator (OEO) is a microwave photonic system with a positive feedback loop used to create microwave oscillation with ultra-low phase noise thanks to the employment of a high-quality-factor energy storage element, such as a fiber delay line. For many applications, a frequency-tunable microwave signal or waveform, such as a linearly chirped microwave waveform (LCMW), is also needed. Due to the long characteristic time constant required for building up stable oscillation at an oscillation mode, it is impossible to generate an LCMW with a large chirp rate using a conventional frequency-tunable OEO. In this study, we propose and demonstrate a new scheme to generate a large chirp-rate LCMW based on Fourier domain mode locking technique to break the limitation of mode building time in an OEO. An LCMW with a high chirp rate of 0.34 GHz/μs and a large time-bandwidth product of 166,650 is demonstrated.

  12. Experimental demonstration of revival of oscillations from death in coupled nonlinear oscillators.

    PubMed

    Senthilkumar, D V; Suresh, K; Chandrasekar, V K; Zou, Wei; Dana, Syamal K; Kathamuthu, Thamilmaran; Kurths, Jürgen

    2016-04-01

    We experimentally demonstrate that a processing delay, a finite response time, in the coupling can revoke the stability of the stable steady states, thereby facilitating the revival of oscillations in the same parameter space where the coupled oscillators suffered the quenching of oscillation. This phenomenon of reviving of oscillations is demonstrated using two different prototype electronic circuits. Further, the analytical critical curves corroborate that the spread of the parameter space with stable steady state is diminished continuously by increasing the processing delay. Finally, the death state is completely wiped off above a threshold value by switching the stability of the stable steady state to retrieve sustained oscillations in the same parameter space. The underlying dynamical mechanism responsible for the decrease in the spread of the stable steady states and the eventual reviving of oscillation as a function of the processing delay is explained using analytical results.

  13. Experimental demonstration of revival of oscillations from death in coupled nonlinear oscillators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Senthilkumar, D. V., E-mail: skumarusnld@gmail.com; Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA University, Thanjavur 613 401; Suresh, K.

    We experimentally demonstrate that a processing delay, a finite response time, in the coupling can revoke the stability of the stable steady states, thereby facilitating the revival of oscillations in the same parameter space where the coupled oscillators suffered the quenching of oscillation. This phenomenon of reviving of oscillations is demonstrated using two different prototype electronic circuits. Further, the analytical critical curves corroborate that the spread of the parameter space with stable steady state is diminished continuously by increasing the processing delay. Finally, the death state is completely wiped off above a threshold value by switching the stability of themore » stable steady state to retrieve sustained oscillations in the same parameter space. The underlying dynamical mechanism responsible for the decrease in the spread of the stable steady states and the eventual reviving of oscillation as a function of the processing delay is explained using analytical results.« less

  14. High-energy green supercapacitor driven by ionic liquid electrolytes as an ultra-high stable next-generation energy storage device

    NASA Astrophysics Data System (ADS)

    Thangavel, Ranjith; Kannan, Aravindaraj G.; Ponraj, Rubha; Thangavel, Vigneysh; Kim, Dong-Won; Lee, Yun-Sung

    2018-04-01

    Development of supercapacitors with high energy density and long cycle life using sustainable materials for next-generation applications is of paramount importance. The ongoing challenge is to elevate the energy density of supercapacitors on par with batteries, while upholding the power and cyclability. In addition, attaining such superior performance with green and sustainable bio-mass derived compounds is very crucial to address the rising environmental concerns. Herein, we demonstrate the use of watermelon rind, a bio-waste from watermelons, towards high energy, and ultra-stable high temperature green supercapacitors with a high-voltage ionic liquid electrolyte. Supercapacitors assembled with ultra-high surface area, hierarchically porous carbon exhibits a remarkable performance both at room temperature and at high temperature (60 °C) with maximum energy densities of ∼174 Wh kg-1 (25 °C), and 177 Wh kg-1 (60 °C) - based on active mass of both electrodes. Furthermore, an ultra-high specific power of ∼20 kW kg-1 along with an ultra-stable cycling performance with 90% retention over 150,000 cycles has been achieved even at 60 °C, outperforming supercapacitors assembled with other carbon based materials. These results demonstrate the potential to develop high-performing, green energy storage devices using eco-friendly materials for next generation electric vehicles and other advanced energy storage systems.

  15. An ultra-stable iodine-based frequency reference for space applications

    NASA Astrophysics Data System (ADS)

    Schuldt, Thilo; Braxmaier, Claus; Doeringshoff, Klaus; Keetman, Anja; Reggentin, Matthias; Kovalchuk, Evgeny; Peters, Achim

    2012-07-01

    Future space missions require for ultra-stable optical frequency references. Examples are the gravitational wave detector LISA/eLISA (Laser Interferometer Space Antenna), the SpaceTime Asymmetry Research (STAR) program, the aperture-synthesis telescope Darwin and the GRACE (Gravity Recovery and Climate Experiment) follow on mission exploring Earth's gravity. As high long-term frequency stability is required, lasers stabilized to atomic or molecular transitions are preferred, also offering an absolute frequency reference. Frequency stabilities in the 10 ^{-15} domains at longer integration times (up to several hours) are demonstrated in laboratory experiments using setups based on Doppler-free spectroscopy. Such setups with a frequency stability comparable to the hydrogen maser in the microwave domain, have the potential to be developed space compatible on a relatively short time scale. Here, we present the development of ultra-stable optical frequency references based on modulation-transfer spectroscopy of molecular iodine. Noise levels of 2\\cdot10 ^{-14} at an integration time of 1 s and below 3\\cdot10 ^{-15} at integration times between 100 s and 1000 s are demonstrated with a laboratory setup using an 80 cm long iodine cell in single-pass configuration in combination with a frequency-doubled Nd:YAG laser and standard optical components and optomechanic mounts. The frequency stability at longer integration times is (amongst other things) limited by the dimensional stability of the optical setup, i.e. by th pointing stability of the two counter-propagating beams overlapped in the iodine cell. With the goal of a future space compatible setup, a compact frequency standard on EBB (elegant breadboard) level was realized. The spectroscopy unit utilizes a baseplate made of Clearceram-HS, a glass ceramics with an ultra-low coefficient of thermal expansion of 2\\cdot10 ^{-8} K ^{-1}. The optical components are joint to the baseplate using adhesive bonding technology

  16. AOM optimization with ultra stable high power CO2 lasers for fast laser engraving

    NASA Astrophysics Data System (ADS)

    Bohrer, Markus

    2015-05-01

    A new ultra stable CO2 laser in carbon fibre resonator technology with an average power of more than 600W has been developed especially as basis for the use with AOMs. Stability of linear polarisation and beam pointing stability are important issues as well as appropriate shaping of the incident beam. AOMs are tested close to the laser-induced damage threshold with pulses on demand close to one megahertz. Transversal and rotational optimization of the AOMs benefits from the parallel-kinematic principle of a hexapod used for this research.

  17. Ultra-stable clock laser system development towards space applications.

    PubMed

    Świerad, Dariusz; Häfner, Sebastian; Vogt, Stefan; Venon, Bertrand; Holleville, David; Bize, Sébastien; Kulosa, André; Bode, Sebastian; Singh, Yeshpal; Bongs, Kai; Rasel, Ernst Maria; Lodewyck, Jérôme; Le Targat, Rodolphe; Lisdat, Christian; Sterr, Uwe

    2016-09-26

    The increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10 -16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm 3 ; and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm 3 . The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10 -10 /g, 5.8 × 10 -10 /g and 3.1 × 10 -10 /g, where g ≈ 9.8 m/s 2 is the standard gravitational acceleration.

  18. The flight performance of the Galileo orbiter USO

    NASA Technical Reports Server (NTRS)

    Morabito, D. D.; Krisher, T. P.; Asmar, S. W.

    1993-01-01

    Results are presented from an analysis of radio metric data received by the DSN stations from the Galileo spacecraft using an Ultrastable Oscillator (USO) as a signal source. These results allow the health and performance of the Galileo USO to be evaluated, and are used to calibrate this Radio Science instrument and the data acquired for Radio Science experiments such as the Red-shift Observation, Solar Conjunction, and Jovian occultations. Estimates for the USO-referenced spacecraft-transmitted frequency and frequency stability were made for 82 data acquisition passes conducted between launch (October 1989) and November 1991. Analyses of the spacecraft-transmitted frequencies show that the USO is behaving as expected. The USO was powered off and then back on in August 1991 with no adverse effect on its performance. The frequency stabilities measured by Allan deviation are consistent with expected values due to thermal wideband noise and the USO itself at the appropriate time intervals. The Galileo USO appears to be healthy and functioning normally in a reasonable manner.

  19. The flight performance of the Galileo orbiter USO

    NASA Technical Reports Server (NTRS)

    Morabito, D. D.; Krisher, T. P.; Asmar, S. W.

    1993-01-01

    Results are presented in this article from an analysis of radio metric data received by the DSN stations from the Galileo spacecraft using an Ultrastable Oscillator (USO) as a signal source. These results allow the health and performance of the Galileo USO to be evaluated, and are used to calibrate this Radio Science instrument and the data acquired for Radio Science experiments such as the Redshift Observation, Solar Conjunction, and Jovian occultations. Estimates for the USO-referenced, spacecraft-transmitted frequency and frequency stability were made for 82 data acquisition passes conducted between launch (Oct. 1989) and Nov. 1991. Analyses of the spacecraft-transmitted frequencies show that the USO is behaving as expected. The USO was powered off and then back on in Aug. 1991 with no adverse effect on its performance. The frequency stabilities measured by Allan deviation are consistent with expected values due to thermal wideband noise and the USO itself at the appropriate time intervals. The Galileo USO appears to be healthy and functioning normally in a reasonable manner.

  20. Chip Scale Ultra-Stable Clocks: Miniaturized Phonon Trap Timing Units for PNT of CubeSats

    NASA Technical Reports Server (NTRS)

    Rais-Zadeh, Mina; Altunc, Serhat; Hunter, Roger C.; Petro, Andrew

    2016-01-01

    The Chip Scale Ultra-Stable Clocks (CSUSC) project aims to provide a superior alternative to current solutions for low size, weight, and power timing devices. Currently available quartz-based clocks have problems adjusting to the high temperature and extreme acceleration found in space applications, especially when scaled down to match small spacecraft size, weight, and power requirements. The CSUSC project aims to utilize dual-mode resonators on an ovenized platform to achieve the exceptional temperature stability required for these systems. The dual-mode architecture utilizes a temperature sensitive and temperature stable mode simultaneously driven on the same device volume to eliminate ovenization error while maintaining extremely high performance. Using this technology it is possible to achieve parts-per-billion (ppb) levels of temperature stability with multiple orders of magnitude smaller size, weight, and power.

  1. Characterization of an ultra-stable optical cavity developed in the industry for space applications

    NASA Astrophysics Data System (ADS)

    Argence, Berengere; Bize, S.; Lemonde, P.; Santarelli, G.; Prevost, E.; Le Goff, R.; Lévèque, T.

    2017-11-01

    We report the main characteristics and performances of the first - to our knowledge - prototype of an ultra-stable cavity designed and produced by industry with the aim of space missions. The cavity is a 100 mm long cylinder rigidly held at its midplane by an engineered mechanical interface providing an efficient decoupling from thermal and vibration perturbations. The spacer is made from Ultra-Low Expansion (ULE) glass and mirrors substrate from fused silica to reduce the thermal noise limit to 4x10-16. Finite element modeling was performed in order to minimize thermal and vibration sensitivities while getting a high fundamental resonance frequency. The system was designed to be transportable, acceleration tolerant (up to several g) and temperature range compliant [-33°C +73°C]. The axial vibration sensitivity was evaluated at 4x10-11 /(ms-2), while the transverse one is < 1x10-11 /(ms-2). The fractional frequency instability is < 1x10-15 from 0.1 to few seconds and reaches 5-6x10-16 at 1s.

  2. Oscillator metrology with software defined radio.

    PubMed

    Sherman, Jeff A; Jördens, Robert

    2016-05-01

    Analog electrical elements such as mixers, filters, transfer oscillators, isolating buffers, dividers, and even transmission lines contribute technical noise and unwanted environmental coupling in time and frequency measurements. Software defined radio (SDR) techniques replace many of these analog components with digital signal processing (DSP) on rapidly sampled signals. We demonstrate that, generically, commercially available multi-channel SDRs are capable of time and frequency metrology, outperforming purpose-built devices by as much as an order-of-magnitude. For example, for signals at 10 MHz and 6 GHz, we observe SDR time deviation noise floors of about 20 fs and 1 fs, respectively, in under 10 ms of averaging. Examining the other complex signal component, we find a relative amplitude measurement instability of 3 × 10(-7) at 5 MHz. We discuss the scalability of a SDR-based system for simultaneous measurement of many clocks. SDR's frequency agility allows for comparison of oscillators at widely different frequencies. We demonstrate a novel and extreme example with optical clock frequencies differing by many terahertz: using a femtosecond-laser frequency comb and SDR, we show femtosecond-level time comparisons of ultra-stable lasers with zero measurement dead-time.

  3. Activity patterns in networks stabilized by background oscillations.

    PubMed

    Hoppensteadt, Frank

    2009-07-01

    The brain operates in a highly oscillatory environment. We investigate here how such an oscillating background can create stable organized behavior in an array of neuro-oscillators that is not observable in the absence of oscillation, much like oscillating the support point of an inverted pendulum can stabilize its up position, which is unstable without the oscillation. We test this idea in an array of electronic circuits coming from neuroengineering: we show how the frequencies of the background oscillation create a partition of the state space into distinct basins of attraction. Thus, background signals can stabilize persistent activity that is otherwise not observable. This suggests that an image, represented as a stable firing pattern which is triggered by a voltage pulse and is sustained in synchrony or resonance with the background oscillation, can persist as a stable behavior long after the initial stimulus is removed. The background oscillations provide energy for organized behavior in the array, and these behaviors are categorized by the basins of attraction determined by the oscillation frequencies.

  4. Rotation-excited perfect oscillation of a tri-walled nanotube-based oscillator at ultralow temperature

    NASA Astrophysics Data System (ADS)

    Cai, Kun; Zhang, Xiaoni; Shi, Jiao; Qin, Qing H.

    2017-04-01

    In recent years, carbon-nanotube (CNT)-based gigahertz oscillators have been widely used in numerous areas of practical engineering such as high-speed digital, analog circuits, and memory cells. One of the major challenges to practical applications of the gigahertz oscillator is generating a stable oscillation process from the gigahertz oscillators and then maintaining the stable process for a specified period of time. To address this challenge, an oscillator from a triple-walled CNT-based rotary system is proposed and analyzed numerically in this paper, using a molecular dynamics approach. In this system, the outer tube is fixed partly as a stator. The middle tube, with a constant rotation, is named Rotor 2 and runs in the stator. The inner tube acts as Rotor 1, which can rotate freely in Rotor 2. Due to the friction between the two rotors when they have relative motion, the rotational frequency of Rotor 1 increases continuously and tends to converge with that of Rotor 2. During rotation, the oscillation of Rotor 1 may be excited owing to both a strong end barrier at Rotor 2 and thermal vibration of atoms in the tubes. From the discussion on the effects of length of Rotor 1, temperature, and input rotational frequency of Rotor 2 on the dynamic response of Rotor 1, an effective way to control the oscillation of Rotor 1 is found. Being much longer than Rotor 2, Rotor 1 will have perfect oscillation, i.e., with both stable (or nearly constant) period and amplitude—especially at relatively low temperature. This discovery can be taken as a useful guidance for the design of an oscillator from CNTs.

  5. Rotation-excited perfect oscillation of a tri-walled nanotube-based oscillator at ultralow temperature.

    PubMed

    Cai, Kun; Zhang, Xiaoni; Shi, Jiao; Qin, Qing H

    2017-04-18

    In recent years, carbon-nanotube (CNT)-based gigahertz oscillators have been widely used in numerous areas of practical engineering such as high-speed digital, analog circuits, and memory cells. One of the major challenges to practical applications of the gigahertz oscillator is generating a stable oscillation process from the gigahertz oscillators and then maintaining the stable process for a specified period of time. To address this challenge, an oscillator from a triple-walled CNT-based rotary system is proposed and analyzed numerically in this paper, using a molecular dynamics approach. In this system, the outer tube is fixed partly as a stator. The middle tube, with a constant rotation, is named Rotor 2 and runs in the stator. The inner tube acts as Rotor 1, which can rotate freely in Rotor 2. Due to the friction between the two rotors when they have relative motion, the rotational frequency of Rotor 1 increases continuously and tends to converge with that of Rotor 2. During rotation, the oscillation of Rotor 1 may be excited owing to both a strong end barrier at Rotor 2 and thermal vibration of atoms in the tubes. From the discussion on the effects of length of Rotor 1, temperature, and input rotational frequency of Rotor 2 on the dynamic response of Rotor 1, an effective way to control the oscillation of Rotor 1 is found. Being much longer than Rotor 2, Rotor 1 will have perfect oscillation, i.e., with both stable (or nearly constant) period and amplitude-especially at relatively low temperature. This discovery can be taken as a useful guidance for the design of an oscillator from CNTs.

  6. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gritschneder, Matthias; Heigl, Stefan; Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de

    2017-01-10

    We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidalmore » perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.« less

  7. Chip Scale Atomic Resonator Frequency Stabilization System With Ultra-Low Power Consumption for Optoelectronic Oscillators.

    PubMed

    Zhao, Jianye; Zhang, Yaolin; Lu, Haoyuan; Hou, Dong; Zhang, Shuangyou; Wang, Zhong

    2016-07-01

    We present a long-term chip scale stabilization scheme for optoelectronic oscillators (OEOs) based on a rubidium coherent population trapping (CPT) atomic resonator. By locking a single mode of an OEO to the (85)Rb 3.035-GHz CPT resonance utilizing an improved phase-locked loop (PLL) with a PID regulator, we achieved a chip scale frequency stabilization system for the OEO. The fractional frequency stability of the stabilized OEO by overlapping Allan deviation reaches 6.2 ×10(-11) (1 s) and  ∼ 1.45 ×10 (-11) (1000 s). This scheme avoids a decrease in the extra phase noise performance induced by the electronic connection between the OEO and the microwave reference in common injection locking schemes. The total physical package of the stabilization system is [Formula: see text] and the total power consumption is 400 mW, which provides a chip scale and portable frequency stabilization approach with ultra-low power consumption for OEOs.

  8. ``Stable'' Quasi-periodic Oscillations and Black Hole Properties from Diskoseismology

    NASA Astrophysics Data System (ADS)

    Wagoner, Robert V.; Silbergleit, Alexander S.; Ortega-Rodríguez, Manuel

    2001-09-01

    We compare our calculations of the frequencies of the fundamental g-, c-, and p-modes of relativistic thin accretion disks with recent observations of high-frequency quasi-periodic oscillations (QPOs) in X-ray binaries with black hole candidates. These classes of modes encompass all adiabatic perturbations of such disks. The frequencies of these modes depend mainly on the mass and angular momentum of the black hole; their weak dependence on disk luminosity is also explicitly indicated. Identifying the recently discovered, relatively stable QPO pairs with the fundamental g- and c-modes provides a determination of the mass and angular momentum of the black hole. For GRO J1655-40, M=5.9+/-1.0 Msolar and J=(0.917+/-0.024)GM2/c, in agreement with spectroscopic mass determinations. For GRS 1915+105, M=42.4+/-7.0 Msolar and J=(0.926+/-0.020)GM2/c or (less favored) M=18.2+/-3.1 Msolar and J=(0.701+/-0.043)GM2/c. We briefly address the issues of the amplitude, frequency width, and energy dependence of these QPOs.

  9. Self-oscillation in spin torque oscillator stabilized by field-like torque

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taniguchi, Tomohiro; Tsunegi, Sumito; Kubota, Hitoshi

    2014-04-14

    The effect of the field-like torque on the self-oscillation of the magnetization in spin torque oscillator with a perpendicularly magnetized free layer was studied theoretically. A stable self-oscillation at zero field is excited for negative β while the magnetization dynamics stops for β = 0 or β > 0, where β is the ratio between the spin torque and the field-like torque. The reason why only the negative β induces the self-oscillation was explained from the view point of the energy balance between the spin torque and the damping. The oscillation power and frequency for various β were also studied by numerical simulation.

  10. An ultra-stable optical frequency reference for space

    NASA Astrophysics Data System (ADS)

    Schuldt, T.; Döringshoff, K.; Kovalchuk, E.; Pahl, J.; Gohlke, M.; Weise, D.; Johann, U.; Peters, A.; Braxmaier, C.

    2017-11-01

    We realized ultra-stable optical frequency references on elegant breadboard (EBB) and engineering model (EM) level utilizing Doppler-free spectroscopy of molecular iodine near 532nm. A frequency stability of about 1•10-14 at an integration time of 1 s and below 5•10-15 at integration times between 10 s and 100 s was achieved. These values are comparable to the currently best laboratory setups. Both setups use a baseplate made of glass material where the optical components are joint using a specific assembly-integration technology. Compared to the EBB setup, the EM setup is further developed with respect to compactness and mechanical and thermal stability. The EM setup uses a baseplate made of fused silica with dimensions of 380 x 180 x 40 mm3 and a specifically designed 100 x 100 x 30 mm3 rectangular iodine cell in nine-pass configuration with a specific robust cold finger design. The EM setup was subjected to thermal cycling and vibrational testing. Applications of such an optical frequency reference in space can be found in fundamental physics, geoscience, Earth observation, and navigation & ranging. One example is the proposed mSTAR (mini SpaceTime Asymmetry Research) mission, dedicated to perform a Kennedy-Thorndike experiment on a satellite in a sunsynchronous low-Earth orbit. By comparing an iodine standard to a cavity-based frequency reference and integration over 2 year mission lifetime, the Kennedy-Thorndike coefficient will be determined with up to two orders of magnitude higher accuracy than the current best ground experiment. In a current study, the compatibility of the payload with the SaudiSat-4 host vehicle is investigated.

  11. Opto-electronic oscillator and its applications

    NASA Astrophysics Data System (ADS)

    Yao, X. S.; Maleki, Lute

    1997-04-01

    We review the properties of a new class of microwave oscillators called opto-electronic oscillators (OEO). We present theoretical and experimental results of a multi-loop technique for single mode selection. We then describe a new development called coupled OEO (COEO) in which the electrical oscillation is directly coupled with the optical oscillation, producing an OEO that generates stable optical pulses and single mode microwave oscillation simultaneously. Finally we discuss various applications of OEO.

  12. Ultra Stable Microwave Radiometers for Future Sea Surface Salinity Missions

    NASA Technical Reports Server (NTRS)

    Wilson, William J.; Tanner, Alan B.; Pellerano, Fernando A.; Horgan, Kevin A.

    2005-01-01

    The NASA Earth Science System Pathfinder (ESSP) mission Aquarius will measure global sea surface salinity with 100-km spatial resolution every 8 days with an average monthly salinity accuracy of 0.2 psu (parts per thousand). This requires an L-band low-noise radiometer with the long-term calibration stability of less than 0.1 K over 8 days. This three-year research program on ultra stable radiometers has addressed the radiometer requirements and configuration necessary to achieve this objective for Aquarius and future ocean salinity missions. The system configuration and component performance have been evaluated with radiometer testbeds at both JPL and GSFC. The research has addressed several areas including component characterization as a function of temperature, a procedure for the measurement and correction for radiometer system non-linearity, noise diode calibration versus temperature, low noise amplifier performance over voltage, and temperature control requirements to achieve the required stability. A breadboard radiometer, utilizing microstrip-based technologies, has been built to demonstrate this long-term stability. This report also presents the results of the radiometer test program, a detailed radiometer noise model, and details of the operational switching sequence optimization that can be used to achieve the low noise and stability requirements. Many of the results of this research have been incorporated into the Aquarius radiometer design and will allow this instrument to achieve its goals.

  13. New class of optoelectronic oscillators (OEO) for microwave signal generation and processing

    NASA Astrophysics Data System (ADS)

    Maleki, Lute; Yao, X. S.

    1996-11-01

    A new class of oscillators based on photonic devices is presented. These opto-electronic oscillators (OEO's) generate microwave oscillation by converting continuous energy from a light source using a feedback circuit which includes a delay element, an electro-optic switch, and a photodetector. Different configurations of OEO's are presented, each of which may be applied to a particular application requiring ultra-high performance, or low cost and small size.

  14. Synchronisation of networked Kuramoto oscillators under stable Lévy noise

    NASA Astrophysics Data System (ADS)

    Kalloniatis, Alexander C.; Roberts, Dale O.

    2017-01-01

    We study the Kuramoto model on several classes of network topologies examining the dynamics under the influence of Lévy noise. Such noise exhibits heavier tails than Gaussian and allows us to understand how 'shocks' influence the individual oscillator and collective system behaviour. Skewed α-stable Lévy noise, equivalent to fractional diffusion perturbations, are considered. We perform numerical simulations for Erdős-Rényi (ER) and Barabási-Albert (BA) scale free networks of size N = 1000 while varying the Lévy index α for the noise. We find that synchrony now assumes a surprising variety of forms, not seen for Gaussian-type noise, and changing with α: a noise-generated drift, a smooth α dependence of the point of cross-over of ER and BA networks in the degree of synchronisation, and a severe loss of synchronisation at low values of α. We also show that this robustness of the BA network across most values of α can also be understood as a consequence of the Laplacian of the graph working within the fractional Fokker-Planck equation of the linearised system, close to synchrony, with both eigenvalues and eigenvectors alternately contributing in different regimes of α.

  15. Generalizing the transition from amplitude to oscillation death in coupled oscillators.

    PubMed

    Zou, Wei; Senthilkumar, D V; Koseska, Aneta; Kurths, Jürgen

    2013-11-01

    Amplitude death (AD) and oscillation death (OD) are two structurally different oscillation quenching types in coupled nonlinear oscillators. The transition from AD to OD has been recently realized due to the interplay between heterogeneity and coupling strength [A. Koseska et al., Phys. Rev. Lett. 111, 024103 (2013)]. We identify here the transition from AD to OD in nonlinear oscillators with couplings of distinct natures. It is demonstrated that the presence of time delay in the coupling cannot induce such a transition in identical oscillators, but it can indeed facilitate its occurrence with a low degree of heterogeneity. Moreover, it is further shown that the AD to OD transition is reliably observed in identical oscillators with dynamic and conjugate couplings. The coexistence of AD and OD and rich stable OD configurations after the transition are revealed, which are of great significance for potential applications in physics, biology, and control studies.

  16. Prospects for Ultra-Stable Timekeeping with Sealed Vacuum Operation in Multi-Pole Linear Ion Trap Standards

    NASA Technical Reports Server (NTRS)

    Burt, Eric A.; Tjoelker, R. L.

    2007-01-01

    A recent long-term comparison between the compensated multi-pole Linear Ion Trap Standard (LITS) and the laser-cooled primary standards via GPS carrier phase time transfer showed a deviation of less than 2.7x10(exp -17)/day. A subsequent evaluation of potential drift contributors in the LITS showed that the leading candidates are fluctuations in background gases and the neon buffer gas. The current vacuum system employs a "flow-through" turbomolecular pump and a diaphragm fore pump. Here we consider the viability of a "sealed" vacuum system pumped by a non-evaporable getter for long-term ultra-stable clock operation. Initial tests suggests that both further stability improvement and longer mean-time-between-maintenance can be achieved using this approach

  17. Thermoelectric properties of an ultra-thin topological insulator.

    PubMed

    Islam, S K Firoz; Ghosh, T K

    2014-04-23

    Thermoelectric coefficients of an ultra-thin topological insulator are presented here. The hybridization between top and bottom surface states of a topological insulator plays a significant role. In the absence of a magnetic field, the thermopower increases and thermal conductivity decreases with an increase in the hybridization energy. In the presence of a magnetic field perpendicular to the ultra-thin topological insulator, thermoelectric coefficients exhibit quantum oscillations with inverse magnetic field, whose frequency is strongly modified by the Zeeman energy and whose phase factor is governed by the product of the Landé g-factor and the hybridization energy. In addition to the numerical results, the low-temperature approximate analytical results for the thermoelectric coefficients are also provided. It is also observed that for a given magnetic field these transport coefficients oscillate with hybridization energy, at a frequency that depends on the Landé g-factor.

  18. Cluster dynamics of pulse coupled oscillators

    NASA Astrophysics Data System (ADS)

    O'Keeffe, Kevin; Strogatz, Steven; Krapivsky, Paul

    2015-03-01

    We study the dynamics of networks of pulse coupled oscillators. Much attention has been devoted to the ultimate fate of the system: which conditions lead to a steady state in which all the oscillators are firing synchronously. But little is known about how synchrony builds up from an initially incoherent state. The current work addresses this question. Oscillators start to synchronize by forming clusters of different sizes that fire in unison. First pairs of oscillators, then triplets and so on. These clusters progressively grow by coalescing with others, eventually resulting in the fully synchronized state. We study the mean field model in which the coupling between oscillators is all to all. We use probabilistic arguments to derive a recursive set of evolution equations for these clusters. Using a generating function formalism, we derive simple equations for the moments of these clusters. Our results are in good agreement simulation. We then numerically explore the effects of non-trivial connectivity. Our results have potential application to ultra-low power ``impulse radio'' & sensor networks.

  19. Compact high-pulse-energy passively Q-switched Nd:YLF laser with an ultra-low-magnification unstable resonator: application for efficient optical parametric oscillator.

    PubMed

    Cho, C Y; Huang, Y P; Huang, Y J; Chen, Y C; Su, K W; Chen, Y F

    2013-01-28

    We exploit an ultra-low-magnification unstable resonator to develop a high-pulse-energy side-pumped passively Q-switched Nd:YLF/Cr⁴⁺:YAG laser with improving beam quality. A wedged laser crystal is employed in the cavity to control the emissions at 1047 nm and 1053 nm independently through the cavity alignment. The pulse energies at 1047 nm and 1053 nm are found to be 19 mJ and 23 mJ, respectively. The peak powers for both wavelengths are higher than 2 MW. Furthermore, the developed Nd:YLF lasers are employed to pump a monolithic optical parametric oscillator for confirming the applicability in nonlinear wavelength conversions.

  20. North-south asymmetry of ultra-low-frequency oscillations of Earth's electromagnetic field

    NASA Astrophysics Data System (ADS)

    Guglielmi, Anatol; Klain, Boris; Potapov, Alexander

    2017-12-01

    In the paper, we present the result of an experimental study of north-south asymmetry of ultralow-frequency electromagnetic oscillations IPCL. This study is based on observations made at Mirny Observatory (Antarctica). IPCLs are excited in the dayside sector of the auroral oval in the range 3-10 min periods and represent one of the most powerful types of oscillations of Earth's magnetosphere. These oscillations were discovered in the 1970s during IPhE AS USSR polar expeditions organized by Prof. V.A. Troitskaya. We have shown that IPCL activity in Mirny depends on the inclination (north-south asymmetry) of interplanetary magnetic field (IMF) lines to the plane of the geomagnetic equator before the front of the magnetosphere. The result suggests a controlling exposure of IMF on the magnetospheric oscillations and gives rise to the hypothesis that IPCLs are forced oscillations of a nonlinear dynamical system whose major structural elements are dayside polar cusps. The paper is dedicated to the memory of Professor V.A. Troitskaya (1917-2010).

  1. Weak Perturbations of Biochemical Oscillators

    NASA Astrophysics Data System (ADS)

    Gailey, Paul

    2001-03-01

    Biochemical oscillators may play important roles in gene regulation, circadian rhythms, physiological signaling, and sensory processes. These oscillations typically occur inside cells where the small numbers of reacting molecules result in fluctuations in the oscillation period. Some oscillation mechanisms have been reported that resist fluctuations and produce more stable oscillations. In this paper, we consider the use of biochemical oscillators as sensors by comparing inherent fluctuations with the effects of weak perturbations to one of the reactants. Such systems could be used to produce graded responses to weak stimuli. For example, a leading hypothesis to explain geomagnetic navigation in migrating birds and other animals is based on magnetochemical reactions. Because the magnitude of magnetochemical effects is small at geomagnetic field strengths, a sensitive, noise resistant detection scheme would be required.

  2. Realization of Ultra-High Spectral Purity with the Opto-Electronic Oscillator

    NASA Technical Reports Server (NTRS)

    Yao, Steve; Maleki, Lute; Ji, Yu; Dick, John

    2000-01-01

    Recent results with the Opto-Electronic Oscillator (OEO) have led to the realization of very high spectral purity. Experimental results have produced a performance characterized by a noise as low as by -50 dBc/Hz at 10 Hz for a 10 GHz OEO. The unit was built in a compact package containing an integrated DFB laser and the modulator. This performance is significant because the oscillator is free running, and since the noise in an OEO is independent of the oscillation frequency, the same result can also be obtained at higher frequencies. The result also demonstrates that high frequency, high performance, low cost, and miniature OEO can be realized with the integrated photonic technology. We have also developed a novel carrier suppression technique to reduce the 1/f phase noise of the oscillator even further. The technique is based on the use of a long fiber delay, in place of the high Q cavity, to implement carrier suppression. Our preliminary experimental results indicate an extra 10 to 20 dB phase noise reduction of the OEO with this novel technique. Further noise reduction beyond this value is expected with improved circuit design and longer reference fiber.

  3. Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

    NASA Astrophysics Data System (ADS)

    Saule, T.; Holzberger, S.; De Vries, O.; Plötner, M.; Limpert, J.; Tünnermann, A.; Pupeza, I.

    2017-01-01

    We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The µJ-level output is spectrally broadened in a solid-core fiber and compressed to 30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.

  4. Spin pumping driven auto-oscillator for phase-encoded logic—device design and material requirements

    NASA Astrophysics Data System (ADS)

    Rakheja, S.; Kani, N.

    2017-05-01

    In this work, we propose a spin nano-oscillator (SNO) device where information is encoded in the phase (time-shift) of the output oscillations. The spin current required to set up the oscillations in the device is generated through spin pumping from an input nanomagnet that is precessing at RF frequencies. We discuss the operation of the SNO device, in which either the in-plane (IP) or out-of-plane (OOP) magnetization oscillations are utilized toward implementing ultra-low-power circuits. Using physical models of the nanomagnet dynamics and the spin transport through non-magnetic channels, we quantify the reliability of the SNO device using a "scaling ratio". Material requirements for the nanomagnet and the channel to ensure correct logic functionality are identified using the scaling ratio metric. SNO devices consume (2-5)× lower energy compared to CMOS devices and other spin-based devices with similar device sizes and material parameters. The analytical models presented in this work can be used to optimize the performance and scaling of SNO devices in comparison to CMOS devices at ultra-scaled technology nodes.

  5. Effect of High-Frequency Oscillations on Cough Peak Flows Generated by Mechanical In-Exsufflation in Medically Stable Subjects With Amyotrophic Lateral Sclerosis.

    PubMed

    Sancho, Jesús; Bures, Enric; de La Asunción, Saray; Servera, Emilio

    2016-08-01

    Mechanically assisted coughing with mechanical in-exsufflation (MI-E) is recommended for noninvasive management of respiratory secretions in amyotrophic lateral sclerosis (ALS). To improve the effectiveness of the technique, a new device combining MI-E with high-frequency oscillations (HFO) has been developed. This work aimed to assess the effect of HFO on the cough peak flow generated by MI-E in medically stable subjects with ALS. This was a prospective study that included subjects with ALS in a medically stable condition. Cough peak flow generated by MI-E was measured in 4 situations: without HFO, with HFO during insufflation, with HFO during exsufflation, and with HFO in both cycles. The parameters used were: insufflation pressure of +40 cm H2O, exsufflation pressure of -40 cm H2O, insufflation time 2 s, exsufflation time 3 s, amplitude of oscillations 10 cm H2O, and frequency of oscillations 15 Hz. Forty-seven subjects with ALS were included: 66% males, 68.2 ± 9.2 y, 40% with bulbar onset, FVC = 1.7 ± 1.1 L, percent-of-predicted FVC = 54.4 ± 26.6%, cough peak flow = 3.8 ± 2.2 L/s, PImax = -39.4 ± 26.4 cm H2O, revised ALS scale = 28.5 ± 9.3, Norris bulbar subscore = 26.1 ± 10.4. No statistical differences were found in cough peak flow generated by MI-E in the 4 situations (without HFO = 4.0 ± 1.2 L/s, with insufflation HFO = 3.9 ± 1.2 L/s, with exsufflation HFO = 4.1 ± 1.2 L/s, with in-exsufflation HFO = 3.9 ± 1.1 L/s). The addition of HFO to mechanically assisted coughing with MI-E does not have an effect on the cough peak flow of medically stable subjects with ALS. Copyright © 2016 by Daedalus Enterprises.

  6. Chimera states for coupled oscillators.

    PubMed

    Abrams, Daniel M; Strogatz, Steven H

    2004-10-22

    Arrays of identical oscillators can display a remarkable spatiotemporal pattern in which phase-locked oscillators coexist with drifting ones. Discovered two years ago, such "chimera states" are believed to be impossible for locally or globally coupled systems; they are peculiar to the intermediate case of nonlocal coupling. Here we present an exact solution for this state, for a ring of phase oscillators coupled by a cosine kernel. We show that the stable chimera state bifurcates from a spatially modulated drift state, and dies in a saddle-node bifurcation with an unstable chimera state.

  7. Electronic sideband locking of a broadly tunable 318.6 nm ultraviolet laser to an ultra-stable optical cavity

    NASA Astrophysics Data System (ADS)

    Bai, Jiandong; Wang, Jieying; He, Jun; Wang, Junmin

    2017-04-01

    We demonstrate frequency stabilization of a tunable 318.6 nm ultraviolet (UV) laser system using electronic sideband locking. By indirectly changing the frequency of a broadband electro-optic phase modulator, the laser can be continuously tuned over 4 GHz, while a 637.2 nm laser is directly stabilized to a high-finesse ultra-stable optical cavity. The doubling cavity also remains locked to the 637.2 nm light. We show that the tuning range depends mainly on the gain-flattening region of the modulator and the piezo-tunable range of the seed laser. The frequency-stabilized tunable UV laser system is able to compensate for the offset between reference and target frequencies, and has potential applications in precision spectroscopy of cold atoms.

  8. Rayleigh-type parametric chemical oscillation.

    PubMed

    Ghosh, Shyamolina; Ray, Deb Shankar

    2015-09-28

    We consider a nonlinear chemical dynamical system of two phase space variables in a stable steady state. When the system is driven by a time-dependent sinusoidal forcing of a suitable scaling parameter at a frequency twice the output frequency and the strength of perturbation exceeds a threshold, the system undergoes sustained Rayleigh-type periodic oscillation, wellknown for parametric oscillation in pipe organs and distinct from the usual forced quasiperiodic oscillation of a damped nonlinear system where the system is oscillatory even in absence of any external forcing. Our theoretical analysis of the parametric chemical oscillation is corroborated by full numerical simulation of two well known models of chemical dynamics, chlorite-iodine-malonic acid and iodine-clock reactions.

  9. Self-Synchronized Phenomena Generated in Rotor-Type Oscillators: On the Influence of Coupling Condition between Oscillators

    NASA Astrophysics Data System (ADS)

    Bonkobara, Yasuhiro; Mori, Hiroki; Kondou, Takahiro; Ayabe, Takashi

    Self-synchronized phenomena generated in rotor-type oscillators mounted on a straight-line spring-mass system are investigated experimentally and analytically. In the present study, we examine the occurrence region and pattern of self-synchronization in two types of coupled oscillators: rigidly coupled oscillators and elastically coupled oscillators. It is clarified that the existence regions of stable solutions are governed mainly by the linear natural frequency of each spring-mass system. The results of numerical analysis confirm that the self-synchronized solutions of the elastically coupled oscillators correspond to those of the rigidly coupled oscillators. In addition, the results obtained in the present study are compared with the previously reported results for a metronome system and a moving apparatus and the different properties of the phenomena generated in the rotor-type oscillators and the pendulum-type oscillators are shown in terms of the construction of branches of self-synchronized solution and the stability.

  10. Heartbeat of the Southern Oscillation explains ENSO climatic resonances

    NASA Astrophysics Data System (ADS)

    Bruun, John T.; Allen, J. Icarus; Smyth, Timothy J.

    2017-08-01

    The El Niño-Southern Oscillation (ENSO) nonlinear oscillator phenomenon has a far reaching influence on the climate and human activities. The up to 10 year quasi-period cycle of the El Niño and subsequent La Niña is known to be dominated in the tropics by nonlinear physical interaction of wind with the equatorial waveguide in the Pacific. Long-term cyclic phenomena do not feature in the current theory of the ENSO process. We update the theory by assessing low (>10 years) and high (<10 years) frequency coupling using evidence across tropical, extratropical, and Pacific basin scales. We analyze observations and model simulations with a highly accurate method called Dominant Frequency State Analysis (DFSA) to provide evidence of stable ENSO features. The observational data sets of the Southern Oscillation Index (SOI), North Pacific Index Anomaly, and ENSO Sea Surface Temperature Anomaly, as well as a theoretical model all confirm the existence of long-term and short-term climatic cycles of the ENSO process with resonance frequencies of {2.5, 3.8, 5, 12-14, 61-75, 180} years. This fundamental result shows long-term and short-term signal coupling with mode locking across the dominant ENSO dynamics. These dominant oscillation frequency dynamics, defined as ENSO frequency states, contain a stable attractor with three frequencies in resonance allowing us to coin the term Heartbeat of the Southern Oscillation due to its characteristic shape. We predict future ENSO states based on a stable hysteresis scenario of short-term and long-term ENSO oscillations over the next century.Plain Language SummaryThe Pacific El Niño-Southern <span class="hlt">Oscillation</span> (ENSO) nonlinear <span class="hlt">oscillator</span> phenomenon has a far reaching influence on the climate and our human activities. This work can help predict both long-term and short-term future ENSO events and to assess the risk of future climate hysteresis changes: is the elastic band that regulates the ENSO</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983mico.conf..386R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983mico.conf..386R"><span>State of the art in crystal <span class="hlt">oscillators</span> - Present and future</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosati, V. J.; Filler, R. L.; Schodowski, S. S.; Vig, J. R.</p> <p></p> <p>It is pointed out that most military communication, navigation, surveillance and IFF systems which are currently under development require <span class="hlt">stable</span> <span class="hlt">oscillators</span> for frequency control and/or timing. Examples of such systems are the Single Channel Ground and Airborne Radio System (SINCGARS), MILSTAR, the Global Positioning System (GPS), the Combat Identification System (CIS), and several radar systems. In 1981, a survey and evaluation program was initiated with the aim to determine the state-of-the-art of both TCXOs (temperature compensated crystal <span class="hlt">oscillators</span>) and OCXOs (oven controlled crystal <span class="hlt">oscillators</span>). This program is continuing. The results obtained to date are considered because they can provide useful guidance to system users on the availability of <span class="hlt">stable</span> <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPS...360..434C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPS...360..434C"><span>Mesoporous orthorhombic Nb2O5 nanofibers as pseudocapacitive electrodes with <span class="hlt">ultra-stable</span> Li storage characteristics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheong, Jun Young; Jung, Ji-Won; Youn, Doo-Young; Kim, Chanhoon; Yu, Sunmoon; Cho, Su-Ho; Yoon, Ki Ro; Kim, Il-Doo</p> <p>2017-08-01</p> <p><span class="hlt">Ultra-stable</span> pseudocapacitive electrodes for lithium-ion batteries (LIBs) are increasing in demand as highly sustainable energy storage system with excellent charge transport is important. The establishment of facile, controllable, and scalable synthesis of pseudocapacitive electrode materials is an attractive solution to realize such objectives. Here, we have successfully fabricated mesoporous orthorhombic Nb2O5 nanofibers (m-T-Nb2O5 NFs) by simple single-spinneret electrospinning followed by calcination at 600 °C. As-formed m-T-Nb2O5 NFs exhibit high surface area (23.7 m2 g-1) and a number of mesopores in the vacant sites where organic polymer was once decomposed. Such rationally designed m-T-Nb2O5-NFs allow facile Li ion and electron transport, with pseudocapacitive behavior. Arising from the high surface area coupled with mesopores in-between the Nb2O5 nanograins, it exhibits <span class="hlt">ultra</span>-long cycle retention (a capacity of ∼160 mAh g-1 at 500 mA g-1 after 2000 cycles and ∼88 mAh g-1 at 3000 mA g-1 after 5000 cycles) and higher rate capability (∼70 mAh g-1 at 5000 mA g-1). Such cycle retention characteristics of m-T-Nb2O5-NFs are at least 100-fold slower capacity decay compared with previously reported one-dimensional (1D) Nb2O5 nanostructures and even superior or comparable to recently reported Nb2O5-graphene composite materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070031781&hterms=Miyake&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMiyake','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070031781&hterms=Miyake&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMiyake"><span>Preliminary Analysis of the 30-m <span class="hlt">Ultra</span>Boom Flight Test</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Agnes, Gregory S.; Abelson, Robert D.; Miyake, Robert; Lin, John K. H.; Welsh, Joe; Watson, Judith J.</p> <p>2005-01-01</p> <p>Future NASA missions require long, <span class="hlt">ultra</span>-lightweight booms to enable solar sails, large sunshields, and other gossamer-type spacecraft structures. The space experiment discussed in this paper will flight validate the non-traditional <span class="hlt">ultra</span> lightweight rigidizable, inflatable, isogrid structure utilizing graphite shape memory polymer (GR/SMP) called <span class="hlt">Ultra</span>Boom(TradeMark). The focus of this paper is the analysis of the 3-m ground test article. The primary objective of the mission is to show that a combination of ground testing and analysis can predict the on-orbit performance of an <span class="hlt">ultra</span> lightweight boom that is scalable, predictable, and thermomechanically <span class="hlt">stable</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23306425','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23306425"><span>Sustained and transient <span class="hlt">oscillations</span> and chaos induced by delayed antiviral immune response in an immunosuppressive infection model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shu, Hongying; Wang, Lin; Watmough, James</p> <p>2014-01-01</p> <p>Sustained and transient <span class="hlt">oscillations</span> are frequently observed in clinical data for immune responses in viral infections such as human immunodeficiency virus, hepatitis B virus, and hepatitis C virus. To account for these <span class="hlt">oscillations</span>, we incorporate the time lag needed for the expansion of immune cells into an immunosuppressive infection model. It is shown that the delayed antiviral immune response can induce sustained periodic <span class="hlt">oscillations</span>, transient <span class="hlt">oscillations</span> and even sustained aperiodic <span class="hlt">oscillations</span> (chaos). Both local and global Hopf bifurcation theorems are applied to show the existence of periodic solutions, which are illustrated by bifurcation diagrams and numerical simulations. Two types of bistability are shown to be possible: (i) a <span class="hlt">stable</span> equilibrium can coexist with another <span class="hlt">stable</span> equilibrium, and (ii) a <span class="hlt">stable</span> equilibrium can coexist with a <span class="hlt">stable</span> periodic solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29114035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29114035"><span>An <span class="hlt">ultra-stable</span> single-chain insulin analog resists thermal inactivation and exhibits biological signaling duration equivalent to the native protein.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glidden, Michael D; Aldabbagh, Khadijah; Phillips, Nelson B; Carr, Kelley; Chen, Yen-Shan; Whittaker, Jonathan; Phillips, Manijeh; Wickramasinghe, Nalinda P; Rege, Nischay; Swain, Mamuni; Peng, Yi; Yang, Yanwu; Lawrence, Michael C; Yee, Vivien C; Ismail-Beigi, Faramarz; Weiss, Michael A</p> <p>2018-01-05</p> <p>Thermal degradation of insulin complicates its delivery and use. Previous efforts to engineer <span class="hlt">ultra-stable</span> analogs were confounded by prolonged cellular signaling in vivo , of unclear safety and complicating mealtime therapy. We therefore sought an <span class="hlt">ultra-stable</span> analog whose potency and duration of action on intravenous bolus injection in diabetic rats are indistinguishable from wild-type (WT) insulin. Here, we describe the structure, function, and stability of such an analog, a 57-residue single-chain insulin (SCI) with multiple acidic substitutions. Cell-based studies revealed native-like signaling properties with negligible mitogenic activity. Its crystal structure, determined as a novel zinc-free hexamer at 2.8 Å, revealed a native insulin fold with incomplete or absent electron density in the C domain; complementary NMR studies are described in the accompanying article. The stability of the analog (Δ G U 5.0(±0.1) kcal/mol at 25 °C) was greater than that of WT insulin (3.3(±0.1) kcal/mol). On gentle agitation, the SCI retained full activity for >140 days at 45 °C and >48 h at 75 °C. These findings indicate that marked resistance to thermal inactivation in vitro is compatible with native duration of activity in vivo Further, whereas WT insulin forms large and heterogeneous aggregates above the standard 0.6 mm pharmaceutical strength, perturbing the pharmacokinetic properties of concentrated formulations, dynamic light scattering, and size-exclusion chromatography revealed only limited SCI self-assembly and aggregation in the concentration range 1-7 mm Such a combination of favorable biophysical and biological properties suggests that SCIs could provide a global therapeutic platform without a cold chain. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940020015','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940020015"><span>Progress toward <span class="hlt">ultra-stable</span> lasers for use in space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buoncristiani, A. M.; Sandford, S. P.; Amundsen, R. M.</p> <p>1992-01-01</p> <p>This is a summary of a research project that has come to be known as SUNLITE, initially standing for Stanford University - NASA laser in space technology experiment. It involves scientists from the NASA Langley Research Center (LaRC), Stanford University, the National Institute of Standards and Technology (NIST), and the Joint Institute for Laboratory Astrophysics (JILA), and a growing number of other institutions. The long range objective of the SUNLITE effort is to examine the fundamental linewidth and frequency stability limits of an actively stabilized laser <span class="hlt">oscillator</span> in the microgravity and vibration-free environment of space. The ground-based SUNLITE activities supporting that objective will develop a space-qualified, self-contained and completely automated terahertz <span class="hlt">oscillator</span> stabilized to a linewidth of less than 3 Hz, along with a measurement system capable of determining laser linewidth to one part in 10(exp 16). The purpose of this paper is to discuss the critical technologies needed to place stabilized lasers in space and to describe the progress made by the SUNLITE project to develop these technologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA485010','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA485010"><span>Developments in <span class="hlt">Ultra-Stable</span> Quartz <span class="hlt">Oscillators</span> for Deep Space Reliability</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2004-12-01</p> <p>langatate , and III-V compounds such as gallium orthophosphate) exhibit superior electromechanical coupling in a single material phase around room...higher figures of merit than quartz. Indeed, langatate , despite the infancy of its development, has already demonstrated a quality factor that is...Langasite, Langanite, and Langatate Bulk-Wave Y-cut Resonators,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, UFFC-47, 355-360.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26286485','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26286485"><span>Generation of entanglement in quantum parametric <span class="hlt">oscillators</span> using phase control.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gonzalez-Henao, J C; Pugliese, E; Euzzor, S; Abdalah, S F; Meucci, R; Roversi, J A</p> <p>2015-08-19</p> <p>The control of quantum entanglement in systems in contact with environment plays an important role in information processing, cryptography and quantum computing. However, interactions with the environment, even when very weak, entail decoherence in the system with consequent loss of entanglement. Here we consider a system of two coupled <span class="hlt">oscillators</span> in contact with a common heat bath and with a time dependent <span class="hlt">oscillation</span> frequency. The possibility to control the entanglement of the <span class="hlt">oscillators</span> by means of an external sinusoidal perturbation applied to the <span class="hlt">oscillation</span> frequency has been theoretically explored. We demonstrate that the <span class="hlt">oscillators</span> become entangled exactly in the region where the classical counterpart is unstable, otherwise when the classical system is <span class="hlt">stable</span>, entanglement is not possible. Therefore, we can control the entanglement swapping from <span class="hlt">stable</span> to unstable regions by adjusting amplitude and phase of our external controller. We also show that the entanglement rate is approximately proportional to the real part of the Floquet coefficient of the classical counterpart of the <span class="hlt">oscillators</span>. Our results have the intriguing peculiarity of manipulating quantum information operating on a classical system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Chaos..24d3103N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Chaos..24d3103N"><span>Transition from amplitude to <span class="hlt">oscillation</span> death in a network of <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nandan, Mauparna; Hens, C. R.; Pal, Pinaki; Dana, Syamal K.</p> <p>2014-12-01</p> <p>We report a transition from a homogeneous steady state (HSS) to inhomogeneous steady states (IHSSs) in a network of globally coupled identical <span class="hlt">oscillators</span>. We perturb a synchronized population of <span class="hlt">oscillators</span> in the network with a few local negative or repulsive mean field links. The whole population splits into two clusters for a certain number of repulsive mean field links and a range of coupling strength. For further increase of the strength of interaction, these clusters collapse into a HSS followed by a transition to IHSSs where all the <span class="hlt">oscillators</span> populate either of the two <span class="hlt">stable</span> steady states. We analytically determine the origin of HSS and its transition to IHSS in relation to the number of repulsive mean-field links and the strength of interaction using a reductionism approach to the model network. We verify the results with numerical examples of the paradigmatic Landau-Stuart limit cycle system and the chaotic Rössler <span class="hlt">oscillator</span> as dynamical nodes. During the transition from HSS to IHSSs, the network follows the Turing type symmetry breaking pitchfork or transcritical bifurcation depending upon the system dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28548088','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28548088"><span>Direct observation of coherent energy transfer in nonlinear micromechanical <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Changyao; Zanette, Damián H; Czaplewski, David A; Shaw, Steven; López, Daniel</p> <p>2017-05-26</p> <p>Energy dissipation is an unavoidable phenomenon of physical systems that are directly coupled to an external environmental bath. In an oscillatory system, it leads to the decay of the <span class="hlt">oscillation</span> amplitude. In situations where <span class="hlt">stable</span> <span class="hlt">oscillations</span> are required, the energy dissipated by the vibrations is usually compensated by replenishment from external energy sources. Consequently, if the external energy supply is removed, the amplitude of <span class="hlt">oscillations</span> start to decay immediately, since there is no means to restitute the energy dissipated. Here, we demonstrate a novel dissipation engineering strategy that can support <span class="hlt">stable</span> <span class="hlt">oscillations</span> without supplying external energy to compensate losses. The fundamental intrinsic mechanism of resonant mode coupling is used to redistribute and store mechanical energy among vibrational modes and coherently transfer it back to the principal mode when the external excitation is off. To experimentally demonstrate this phenomenon, we exploit the nonlinear dynamic response of microelectromechanical <span class="hlt">oscillators</span> to couple two different vibrational modes through an internal resonance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1364394-direct-observation-coherent-energy-transfer-nonlinear-micromechanical-oscillators','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1364394-direct-observation-coherent-energy-transfer-nonlinear-micromechanical-oscillators"><span>Direct observation of coherent energy transfer in nonlinear micromechanical <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Chen, Changyao; Zanette, Damian H.; Czaplewski, David A.; ...</p> <p>2017-05-26</p> <p>Energy dissipation is an unavoidable phenomenon of physical systems that are directly coupled to an external environmental bath. In an oscillatory system, it leads to the decay of the <span class="hlt">oscillation</span> amplitude. In situations where <span class="hlt">stable</span> <span class="hlt">oscillations</span> are required, the energy dissipated by the vibrations is usually compensated by replenishment from external energy sources. Consequently, if the external energy supply is removed, the amplitude of <span class="hlt">oscillations</span> start to decay immediately, since there is no means to restitute the energy dissipated. Here, we demonstrate a novel dissipation engineering strategy that can support <span class="hlt">stable</span> <span class="hlt">oscillations</span> without supplying external energy to compensate losses. Themore » fundamental intrinsic mechanism of resonant mode coupling is used to redistribute and store mechanical energy among vibrational modes and coherently transfer it back to the principal mode when the external excitation is off. To experimentally demonstrate this phenomenon, we exploit the nonlinear dynamic response of microelectromechanical <span class="hlt">oscillators</span> to couple two different vibrational modes through an internal resonance.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1364394','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1364394"><span>Direct observation of coherent energy transfer in nonlinear micromechanical <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chen, Changyao; Zanette, Damian H.; Czaplewski, David A.</p> <p></p> <p>Energy dissipation is an unavoidable phenomenon of physical systems that are directly coupled to an external environmental bath. In an oscillatory system, it leads to the decay of the <span class="hlt">oscillation</span> amplitude. In situations where <span class="hlt">stable</span> <span class="hlt">oscillations</span> are required, the energy dissipated by the vibrations is usually compensated by replenishment from external energy sources. Consequently, if the external energy supply is removed, the amplitude of <span class="hlt">oscillations</span> start to decay immediately, since there is no means to restitute the energy dissipated. Here, we demonstrate a novel dissipation engineering strategy that can support <span class="hlt">stable</span> <span class="hlt">oscillations</span> without supplying external energy to compensate losses. Themore » fundamental intrinsic mechanism of resonant mode coupling is used to redistribute and store mechanical energy among vibrational modes and coherently transfer it back to the principal mode when the external excitation is off. To experimentally demonstrate this phenomenon, we exploit the nonlinear dynamic response of microelectromechanical <span class="hlt">oscillators</span> to couple two different vibrational modes through an internal resonance.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3970317','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3970317"><span>Sustained Zero-Order Release of Intact <span class="hlt">Ultra-Stable</span> Drug-Loaded Liposomes from an Implantable Nanochannel Delivery System</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Celia, Christian; Ferrati, Silvia; Bansal, Shyam; van de Ven, Anne L.; Ruozi, Barbara; Zabre, Erika; Hosali, Sharath; Paolino, Donatella; Sarpietro, Maria Grazia; Fine, Daniel; Fresta, Massimo; Ferrari, Mauro</p> <p>2014-01-01</p> <p>Metronomic chemotherapy supports the idea that long-term, sustained, constant administration of chemotherapeutics, currently not achievable, could be effective against numerous cancers. Particularly appealing are liposomal formulations, used to solubilize hydrophobic therapeutics and minimize side effects, while extending drug circulation time and enabling passive targeting. As liposome alone cannot survive in circulation beyond 48 hrs, sustaining their constant plasma level for many days is a challenge. To address this, we developed, as a proof of concept, an implantable nanochannel delivery system and <span class="hlt">ultra-stable</span> PEGylated lapatinib loaded-liposomes, and we demonstrate the release of intact vesicles for over 18 days. Further, we investigate intravasation kinetics of subcutaneously delivered liposomes and verify their biological activity post nanochannel release on BT474 breast cancer cells. The key innovation of this work is the combination of two nanotechnologies to exploit the synergistic effect of liposomes, demonstrated as passive-targeting vectors and nanofluidics to maintain therapeutic constant plasma levels. In principle, this approach could maximize efficacy of metronomic treatments. PMID:23881575</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080004891','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080004891"><span>Generation of mechanical <span class="hlt">oscillation</span> applicable to vibratory rate gyroscopes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lemkin, Mark A. (Inventor); Juneau, Thor N. (Inventor); Clark, William A. (Inventor); Roessig, Allen W. (Inventor)</p> <p>2001-01-01</p> <p>To achieve a drive-axis <span class="hlt">oscillation</span> with improved frequency and amplitude stability, additional feedback loops are used to adjust force-feedback loop parameters. An amplitude-control loop measures <span class="hlt">oscillation</span> amplitude, compares this value to the desired level, and adjusts damping of the mechanical sense-element to grow or shrink <span class="hlt">oscillation</span> amplitude as appropriate. A frequency-tuning loop measures the <span class="hlt">oscillation</span> frequency, compares this value with a highly <span class="hlt">stable</span> reference, and adjusts the gain in the force-feedback loop to keep the drive-axis <span class="hlt">oscillation</span> frequency at the reference value. The combined topology simultaneously controls both amplitude and frequency. Advantages of the combined topology include improved stability, fast <span class="hlt">oscillation</span> start-up, low power consumption, and excellent shock rejection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22351001-transition-from-amplitude-oscillation-death-network-oscillators','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22351001-transition-from-amplitude-oscillation-death-network-oscillators"><span>Transition from amplitude to <span class="hlt">oscillation</span> death in a network of <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nandan, Mauparna; Department of Mathematics, National Institute of Technology, Durgapur 713209; Hens, C. R.</p> <p>2014-12-01</p> <p>We report a transition from a homogeneous steady state (HSS) to inhomogeneous steady states (IHSSs) in a network of globally coupled identical <span class="hlt">oscillators</span>. We perturb a synchronized population of <span class="hlt">oscillators</span> in the network with a few local negative or repulsive mean field links. The whole population splits into two clusters for a certain number of repulsive mean field links and a range of coupling strength. For further increase of the strength of interaction, these clusters collapse into a HSS followed by a transition to IHSSs where all the <span class="hlt">oscillators</span> populate either of the two <span class="hlt">stable</span> steady states. We analytically determinemore » the origin of HSS and its transition to IHSS in relation to the number of repulsive mean-field links and the strength of interaction using a reductionism approach to the model network. We verify the results with numerical examples of the paradigmatic Landau-Stuart limit cycle system and the chaotic Rössler <span class="hlt">oscillator</span> as dynamical nodes. During the transition from HSS to IHSSs, the network follows the Turing type symmetry breaking pitchfork or transcritical bifurcation depending upon the system dynamics.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJMPC..2750059Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPC..2750059Z"><span><span class="hlt">Oscillations</span> in interconnected complex networks under intentional attack</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Wen-Ping; Xia, Yongxiang; Tan, Fei</p> <p>2016-01-01</p> <p>Many real-world networks are interconnected with each other. In this paper, we study the traffic dynamics in interconnected complex networks under an intentional attack. We find that with the shortest time delay routing strategy, the traffic dynamics can show the <span class="hlt">stable</span> state, periodic, quasi-periodic and chaotic <span class="hlt">oscillations</span>, when the capacity redundancy parameter changes. Moreover, compared with isolated complex networks, <span class="hlt">oscillations</span> always take place in interconnected networks more easily. Thirdly, in interconnected networks, <span class="hlt">oscillations</span> are affected strongly by the coupling probability and coupling preference.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996OptPN...7...34Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996OptPN...7...34Y"><span>Opto-electronic microwave <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, X. Steve; Maleki, Lute</p> <p>1996-12-01</p> <p>Photonic applications are important in RF communication systems to enhance many functions including remote transfer of antenna signals, carrier frequency up or down conversion, antenna beam steering, and signal filtering. Many of these functions require reference frequency <span class="hlt">oscillators</span>. However, traditional microwave <span class="hlt">oscillators</span> cannot meet all the requirements of photonic communication systems that need high frequency and low phase noise signal generation. Because photonic systems involve signals in both optical and electrical domains, an ideal signal source should be able to provide electrical and optical signals. In addition, it should be possible to synchronize or control the signal source by both electrical and optical means. We present such a source1-2 that converts continuous light energy into <span class="hlt">stable</span> and spectrally pure microwave signals. This Opto-Electronic <span class="hlt">Oscillator</span>, OEO, consists of a pump laser and a feedback circuit including an intensity modulator, an optical fiber delay line, a photodetector, an amplifier, and a filter, as shown in Figure 1a. Its <span class="hlt">oscillation</span> frequency, limited only by the speed of the modulator, can be up to 75 GHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvE..97d2218B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvE..97d2218B"><span>Transition from homogeneous to inhomogeneous limit cycles: Effect of local filtering in coupled <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banerjee, Tanmoy; Biswas, Debabrata; Ghosh, Debarati; Bandyopadhyay, Biswabibek; Kurths, Jürgen</p> <p>2018-04-01</p> <p>We report an interesting symmetry-breaking transition in coupled identical <span class="hlt">oscillators</span>, namely, the continuous transition from homogeneous to inhomogeneous limit cycle <span class="hlt">oscillations</span>. The observed transition is the oscillatory analog of the Turing-type symmetry-breaking transition from amplitude death (i.e., <span class="hlt">stable</span> homogeneous steady state) to <span class="hlt">oscillation</span> death (i.e., <span class="hlt">stable</span> inhomogeneous steady state). This novel transition occurs in the parametric zone of occurrence of rhythmogenesis and <span class="hlt">oscillation</span> death as a consequence of the presence of local filtering in the coupling path. We consider paradigmatic <span class="hlt">oscillators</span>, such as Stuart-Landau and van der Pol <span class="hlt">oscillators</span>, under mean-field coupling with low-pass or all-pass filtered self-feedback and through a rigorous bifurcation analysis we explore the genesis of this transition. Further, we experimentally demonstrate the observed transition, which establishes its robustness in the presence of parameter fluctuations and noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1339556-self-sustained-micro-mechanical-oscillator-linear-feedback','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1339556-self-sustained-micro-mechanical-oscillator-linear-feedback"><span>Self-sustained micro mechanical <span class="hlt">oscillator</span> with linear feedback</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Chen, Changyao; Zanette, Damian H.; Guest, Jeffrey R.; ...</p> <p>2016-07-01</p> <p>Autonomous <span class="hlt">oscillators</span>, such as clocks and lasers, produce periodic signals without any external frequency reference. In order to sustain <span class="hlt">stable</span> periodic motions, there needs to be external energy supply as well as nonlinearity built into the <span class="hlt">oscillator</span> to regulate the amplitude. Usually, nonlinearity is provided by the sustaining feedback mechanism, which also supplies energy, whereas the constituent resonator that determines the output frequency stays linear. Here we propose a new self-sustaining scheme that relies on the nonlinearity originating from the resonator itself to limit the <span class="hlt">oscillation</span> amplitude, while the feedback remains linear. We introduce a model to describe the workingmore » principle of the self-sustained <span class="hlt">oscillations</span> and validate it with experiments performed on a nonlinear microelectromechanical (MEMS) based <span class="hlt">oscillator</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvF...1d0501S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvF...1d0501S"><span>Linear control of <span class="hlt">oscillator</span> and amplifier flows*</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmid, Peter J.; Sipp, Denis</p> <p>2016-08-01</p> <p>Linear control applied to fluid systems near an equilibrium point has important applications for many flows of industrial or fundamental interest. In this article we give an exposition of tools and approaches for the design of control strategies for globally <span class="hlt">stable</span> or unstable flows. For unstable <span class="hlt">oscillator</span> flows a feedback configuration and a model-based approach is proposed, while for <span class="hlt">stable</span> noise-amplifier flows a feedforward setup and an approach based on system identification is advocated. Model reduction and robustness issues are addressed for the <span class="hlt">oscillator</span> case; statistical learning techniques are emphasized for the amplifier case. Effective suppression of global and convective instabilities could be demonstrated for either case, even though the system-identification approach results in a superior robustness to off-design conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22470128-ultra-broadband-near-field-antenna-terahertz-plasmonic-applications','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22470128-ultra-broadband-near-field-antenna-terahertz-plasmonic-applications"><span><span class="hlt">Ultra</span>-broadband near-field antenna for terahertz plasmonic applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Polischuk, O. V., E-mail: polischuk.sfire@mail.ru; Popov, V. V., E-mail: popov-slava@yahoo.co.uk; Knap, W.</p> <p></p> <p>A new type of <span class="hlt">ultra</span>-broadband near-field antenna for terahertz frequencies is proposed. This antenna is a short-period planar metal array. It is theoretically shown that irradiation of the short-period array antenna by a plane homogeneous terahertz waves excite a highly inhomogeneous near electric field near the metal array. In this case, the amplitude of the excited inhomogeneous near electric field is almost independent of frequency in the entire terahertz frequency range. The excitation of plasma <span class="hlt">oscillations</span> in a two-dimensional electron system using the antenna under study is numerically simulated in the resonant and non-resonant plasmonic response modes. This type ofmore » antenna can be used for developing <span class="hlt">ultra</span>-broadband plasmonic detectors of terahertz radiation.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFD.G4008G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFD.G4008G"><span>Forced synchronization of thermoacoustic <span class="hlt">oscillations</span> in a ducted flame</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guan, Yu; Gupta, Vikrant; Kashinath, Karthik; Li, Larry K. B.</p> <p>2016-11-01</p> <p>Forced synchronization is a process in which a self-excited system subjected to external forcing starts to <span class="hlt">oscillate</span> at the forcing frequency ff in place of its own natural frequency fn. There are two motivations for studying this in thermoacoustics: (i) to determine how external forcing could be used to control thermoacoustic <span class="hlt">oscillations</span>, which are harmful to many combustors; and (ii) to better understand the nonlinear interactions between self-excited hydrodynamic and thermoacoustic <span class="hlt">oscillations</span>. In this experimental study, we examine the response of a ducted premixed flame to harmonic acoustic forcing, for two natural states of the system: (1) a state with periodic <span class="hlt">oscillations</span> at f1 and a marginally <span class="hlt">stable</span> mode at f2; and (2) a state with quasiperiodic <span class="hlt">oscillations</span> at two incommensurate frequencies f1 and f2. When forcing the periodic state, we find that the forcing amplitude required for lock-in increases linearly with | ff -f1 | and that the marginally <span class="hlt">stable</span> mode becomes excited when ff f2 . When forcing the quasiperiodic state, we find that the system locks into the forcing when ff f1 or f2 or 1 / 2 (f1 +f2) . These findings should lead to improved control of periodic and aperiodic thermoacoustic <span class="hlt">oscillations</span> in combustors. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3832478','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3832478"><span>Cholinergic Plasticity of <span class="hlt">Oscillating</span> Neuronal Assemblies in Mouse Hippocampal Slices</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zylla, Maura M.; Zhang, Xiaomin; Reichinnek, Susanne; Draguhn, Andreas; Both, Martin</p> <p>2013-01-01</p> <p>The mammalian hippocampus expresses several types of network <span class="hlt">oscillations</span> which entrain neurons into transiently <span class="hlt">stable</span> assemblies. These groups of co-active neurons are believed to support the formation, consolidation and recall of context-dependent memories. Formation of new assemblies occurs during theta- and gamma-<span class="hlt">oscillations</span> under conditions of high cholinergic activity. Memory consolidation is linked to sharp wave-ripple <span class="hlt">oscillations</span> (SPW-R) during decreased cholinergic tone. We hypothesized that increased cholinergic tone supports plastic changes of assemblies while low cholinergic tone favors their stability. Coherent spatiotemporal network patterns were measured during SPW-R activity in mouse hippocampal slices. We compared neuronal activity within the <span class="hlt">oscillating</span> assemblies before and after a transient phase of carbachol-induced gamma <span class="hlt">oscillations</span>. Single units maintained their coupling to SPW-R throughout the experiment and could be re-identified after the transient phase of gamma <span class="hlt">oscillations</span>. However, the frequency of SPW-R-related unit firing was enhanced after muscarinic stimulation. At the network level, these changes resulted in altered patterns of extracellularly recorded SPW-R waveforms. In contrast, recording of ongoing SPW-R activity without intermittent cholinergic stimulation revealed remarkably <span class="hlt">stable</span> repetitive activation of assemblies. These results show that activation of cholinergic receptors induces plasticity at the level of <span class="hlt">oscillating</span> hippocampal assemblies, in line with the different role of gamma- and SPW-R network activity for memory formation and –consolidation, respectively. PMID:24260462</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhyA..391.1900A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhyA..391.1900A"><span>Collective behavior of coupled nonuniform stochastic <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Assis, Vladimir R. V.; Copelli, Mauro</p> <p>2012-02-01</p> <p>Theoretical studies of synchronization are usually based on models of coupled phase <span class="hlt">oscillators</span> which, when isolated, have constant angular frequency. Stochastic discrete versions of these uniform <span class="hlt">oscillators</span> have also appeared in the literature, with equal transition rates among the states. Here we start from the model recently introduced by Wood et al. [K. Wood, C. Van den Broeck, R. Kawai, K. Lindenberg, Universality of synchrony: critical behavior in a discrete model of stochastic phase-coupled <span class="hlt">oscillators</span>, Phys. Rev. Lett. 96 (2006) 145701], which has a collectively synchronized phase, and parametrically modify the phase-coupled <span class="hlt">oscillators</span> to render them (stochastically) nonuniform. We show that, depending on the nonuniformity parameter 0≤α≤1, a mean field analysis predicts the occurrence of several phase transitions. In particular, the phase with collective <span class="hlt">oscillations</span> is <span class="hlt">stable</span> for the complete graph only for α≤α‧<1. At α=1 the <span class="hlt">oscillators</span> become excitable elements and the system has an absorbing state. In the excitable regime, no collective <span class="hlt">oscillations</span> were found in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3771827','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3771827"><span>An optical system for detecting 3D high-speed <span class="hlt">oscillation</span> of a single ultrasound microbubble</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Yuan; Yuan, Baohong</p> <p>2013-01-01</p> <p>As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble <span class="hlt">oscillation</span> is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble <span class="hlt">oscillation</span> is challenging and costly because of the bubble size—a few microns in diameter—and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble <span class="hlt">oscillation</span>. The capability of imaging microbubble high-speed <span class="hlt">oscillation</span> with much lower costs than with an <span class="hlt">ultra</span>-fast framing or streak camera system was demonstrated. In addition, microbubble <span class="hlt">oscillations</span> along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed <span class="hlt">oscillation</span>, especially when budgets are limited. PMID:24049677</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SuMi..113..600T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SuMi..113..600T"><span><span class="hlt">Ultra</span>-small (r<2 nm), <span class="hlt">stable</span> (>1 year) copper oxide quantum dots with wide band gap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Talluri, Bhusankar; Prasad, Edamana; Thomas, Tiju</p> <p>2018-01-01</p> <p>Practical use of quantum dots (QDs) will rely on processes that enable (i) monodispersity, (ii) scalability, (iii) green approaches to manufacturing them. We demonstrate, a green, rapid, soft chemical, and industrial viable approach for obtaining quasi-spherical, <span class="hlt">ultra</span>-small (size ∼2.4 ± 0.5 nm), <span class="hlt">stable</span> (>1 yr), and monodispersed copper oxide QDs (r < 2 nm) based on digestive ripening (DR). These QDs show wide band gap (Eg∼5.3 eV), this substantial band gap increase is currently inexplicable using Brus' equation, and is likely due to surface chemistry of these strongly confined QDs. Capping with triethanolamine (TEA) results in reduction in the average particle diameter from 9 ± 4 nm to 2.4 ± 0.5 nm and an increase of zeta potential (ξ) from +12 ± 2 mV to +31 ± 2 mV. XPS and electron diffraction studies indicate that capped copper oxide QDs which have TEA chemisorbed on its surface are expected to partly stabilize Cu (I) resulting in mixed phase in these QDs. This result is likely to inform efforts that involve achieving monodisperse microstructures and nano-structures, of oxides with a tendency for multivalency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7614150','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7614150"><span>Effects of developer exhaustion on Kodak EKTASPEED Plus, Ektaspeed, and <span class="hlt">Ultra</span>-speed dental films.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thunthy, K H; Weinberg, R</p> <p>1995-01-01</p> <p>In 1994, Eastman Kodak Co. (Rochester, N.Y.) replaced its Ektaspeed film with the EKTASPEED Plus film. The manufacturer claims that one of the advantages of the new film is that it is not strongly affected by exhausted (depleted plus aged) processing solutions. The objective of the experiment was to test this claim. In exhausted solutions, EKTASPEED Plus film lost its speed more rapidly than <span class="hlt">Ultra</span>-speed film but less rapidly than Ektaspeed film; that is, <span class="hlt">Ultra</span>-speed film had the most <span class="hlt">stable</span> speed. EKTASPEED Plus film lost contrast for 2 weeks before stabilizing, whereas <span class="hlt">Ultra</span>-speed and Ektaspeed films continued to lose contrast for 3 weeks. Overall, EKTASPEED Plus film held its contrast over the other two films. EKTASPEED Plus film stopped increasing its film latitude after 2 weeks, whereas <span class="hlt">Ultra</span>-speed and Ektaspeed films continued to increase film latitudes. In conclusion, for the three films studied, EKTASPEED Plus maintained the most constant levels of contrast and latitude in progressively exhausted solutions. All three films lost speed in exhausted solutions; EKTASPEED Plus film was the fastest but <span class="hlt">Ultra</span>-speed film had the most <span class="hlt">stable</span> speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Chaos..23c3142T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Chaos..23c3142T"><span>Dynamics in hybrid complex systems of switches and <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Dane; Fertig, Elana J.; Restrepo, Juan G.</p> <p>2013-09-01</p> <p>While considerable progress has been made in the analysis of large systems containing a single type of coupled dynamical component (e.g., coupled <span class="hlt">oscillators</span> or coupled switches), systems containing diverse components (e.g., both <span class="hlt">oscillators</span> and switches) have received much less attention. We analyze large, hybrid systems of interconnected Kuramoto <span class="hlt">oscillators</span> and Hopfield switches with positive feedback. In this system, <span class="hlt">oscillator</span> synchronization promotes switches to turn on. In turn, when switches turn on, they enhance the synchrony of the <span class="hlt">oscillators</span> to which they are coupled. Depending on the choice of parameters, we find theoretically coexisting <span class="hlt">stable</span> solutions with either (i) incoherent <span class="hlt">oscillators</span> and all switches permanently off, (ii) synchronized <span class="hlt">oscillators</span> and all switches permanently on, or (iii) synchronized <span class="hlt">oscillators</span> and switches that periodically alternate between the on and off states. Numerical experiments confirm these predictions. We discuss how transitions between these steady state solutions can be onset deterministically through dynamic bifurcations or spontaneously due to finite-size fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhyD..223..180T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhyD..223..180T"><span>Spontaneous switching among multiple spatio-temporal patterns in three-<span class="hlt">oscillator</span> systems constructed with oscillatory cells of true slime mold</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takamatsu, Atsuko</p> <p>2006-11-01</p> <p>Three-<span class="hlt">oscillator</span> systems with plasmodia of true slime mold, Physarum polycephalum, which is an oscillatory amoeba-like unicellular organism, were experimentally constructed and their spatio-temporal patterns were investigated. Three typical spatio-temporal patterns were found: rotation ( R), partial in-phase ( PI), and partial anti-phase with double frequency ( PA). In pattern R, phase differences between adjacent <span class="hlt">oscillators</span> were almost 120 ∘. In pattern PI, two <span class="hlt">oscillators</span> were in-phase and the third <span class="hlt">oscillator</span> showed anti-phase against the two <span class="hlt">oscillators</span>. In pattern PA, two <span class="hlt">oscillators</span> showed anti-phase and the third <span class="hlt">oscillator</span> showed frequency doubling <span class="hlt">oscillation</span> with small amplitude. Actually each pattern is not perfectly <span class="hlt">stable</span> but quasi-<span class="hlt">stable</span>. Interestingly, the system shows spontaneous switching among the multiple quasi-<span class="hlt">stable</span> patterns. Statistical analyses revealed a characteristic in the residence time of each pattern: the histograms seem to have Gamma-like distribution form but with a sharp peak and a tail on the side of long period. That suggests the attractor of this system has complex structure composed of at least three types of sub-attractors: a “Gamma attractor”-involved with several Poisson processes, a “deterministic attractor”-the residence time is deterministic, and a “<span class="hlt">stable</span> attractor”-each pattern is <span class="hlt">stable</span>. When the coupling strength was small, only the Gamma attractor was observed and switching behavior among patterns R, PI, and PA almost always via an asynchronous pattern named O. A conjecture is as follows: Internal/external noise exposes each pattern of R, PI, and PA coexisting around bifurcation points: That is observed as the Gamma attractor. As coupling strength increases, the deterministic attractor appears then followed by the <span class="hlt">stable</span> attractor, always accompanied with the Gamma attractor. Switching behavior could be caused by regular existence of the Gamma attractor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PThPS.161..356T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PThPS.161..356T"><span>Synchronization Properties of Slow Cortical <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takekawa, T.; Aoyagi, T.; Fukai, T.</p> <p></p> <p>During slow-wave sleep, the brain shows slow oscillatory activity with remarkable long-range synchrony. Intracellular recordings show that the slow <span class="hlt">oscillation</span> consists of two phases: an textit{up} state and a textit{down} state. Deriving the phase-response function of simplified neuronal systems, we examine the synchronization properties on slow <span class="hlt">oscillations</span> between the textit{up} state and the textit{down} state. As a result, the strange interaction functions are found in some parameter ranges. These functions indicate that the states with the smaller phase lag than a critical value are all <span class="hlt">stable</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26601231','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26601231"><span>Control of coupled <span class="hlt">oscillator</span> networks with application to microgrid technologies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Skardal, Per Sebastian; Arenas, Alex</p> <p>2015-08-01</p> <p>The control of complex systems and network-coupled dynamical systems is a topic of vital theoretical importance in mathematics and physics with a wide range of applications in engineering and various other sciences. Motivated by recent research into smart grid technologies, we study the control of synchronization and consider the important case of networks of coupled phase <span class="hlt">oscillators</span> with nonlinear interactions-a paradigmatic example that has guided our understanding of self-organization for decades. We develop a method for control based on identifying and stabilizing problematic <span class="hlt">oscillators</span>, resulting in a <span class="hlt">stable</span> spectrum of eigenvalues, and in turn a linearly <span class="hlt">stable</span> synchronized state. The amount of control, that is, number of <span class="hlt">oscillators</span>, required to stabilize the network is primarily dictated by the coupling strength, dynamical heterogeneity, and mean degree of the network, and depends little on the structural heterogeneity of the network itself.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MARF40004A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MARF40004A"><span>Control of coupled <span class="hlt">oscillator</span> networks with application to microgrid technologies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arenas, Alex</p> <p></p> <p>The control of complex systems and network-coupled dynamical systems is a topic of vital theoretical importance in mathematics and physics with a wide range of applications in engineering and various other sciences. Motivated by recent research into smart grid technologies, we study the control of synchronization and consider the important case of networks of coupled phase <span class="hlt">oscillators</span> with nonlinear interactions-a paradigmatic example that has guided our understanding of self-organization for decades. We develop a method for control based on identifying and stabilizing problematic <span class="hlt">oscillators</span>, resulting in a <span class="hlt">stable</span> spectrum of eigenvalues, and in turn a linearly <span class="hlt">stable</span> syn- chronized state. The amount of control, that is, number of <span class="hlt">oscillators</span>, required to stabilize the network is primarily dictated by the coupling strength, dynamical heterogeneity, and mean degree of the network, and depends little on the structural heterogeneity of the network itself.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29625687','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29625687"><span><span class="hlt">Ultra</span>-sensitive, <span class="hlt">stable</span> isotope assisted quantification of multiple urinary mycotoxin exposure biomarkers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Šarkanj, Bojan; Ezekiel, Chibundu N; Turner, Paul C; Abia, Wilfred A; Rychlik, Michael; Krska, Rudolf; Sulyok, Michael; Warth, Benedikt</p> <p>2018-08-17</p> <p>There is a critical need to better understand the patterns, levels and combinatory effects of exposures we are facing through our diet and environment. Mycotoxin mixtures are of particular concern due to chronic low dose exposures caused by naturally contaminated food. To facilitate new insights into their role in chronic disease, mycotoxins and their metabolites are quantified in bio-fluids as biomarkers of exposure. Here, we describe a highly sensitive urinary assay based on <span class="hlt">ultra</span>-high performance liquid chromatography - tandem mass spectrometer (UHPLC-MS/MS) and 13 C-labelled or deuterated internal standards covering the most relevant regulated and emerging mycotoxins. Utilizing enzymatic pre-treatment, solid phase extraction and UHPLC separation, the sensitivity of the method was significantly higher (10-160x lower LODs) than in a previously described method used for comparison purpose, and <span class="hlt">stable</span> isotopes provided compensation for challenging matrix effects. This method was in-house validated and applied to re-assess mycotoxin exposure in urine samples obtained from Nigerian children, adolescent and adults, naturally exposed through their regular diet. Owing to the methods high sensitivity, biomarkers were detected in all samples. The mycoestrogen zearalenone was the most frequently detected contaminant (82%) but also ochratoxin A (76%), aflatoxin M 1 (73%) and fumonisin B 1 (71%) were quantified in a large share of urines. Overall, 57% of 120 urines were contaminated with both, aflatoxin M 1 and fumonisin B 1 , and other co-exposures were frequent. These results clearly demonstrate the advanced performance of the method to assess lowest background exposures (pg mL -1 range) using a single, highly robust assay that will allow for the systematic investigation of low dose effects on human health. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27775529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27775529"><span>A Biochemical <span class="hlt">Oscillator</span> Using Excitatory Molecules for Nanonetworks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shitiri, Ethungshan; Cho, Ho-Shin</p> <p>2016-10-01</p> <p>For nanonetworks to be able to achieve large-scale functionality, such as to respond collectively to a trigger, synchrony between nanomachines is essential. However, to facilitate synchronization, some sort of physical clocking mechanism is required, such as the <span class="hlt">oscillators</span> driven by auto-inhibitory molecules or by auto-inducing molecules. In this study, taking inspiration from the widely studied biological oscillatory phenomena called Calcium (Ca 2+ ) <span class="hlt">oscillations</span>, we undertake a different approach to design an <span class="hlt">oscillator</span>. Our model employs three different types of excitatory molecules that work in tandem to generate oscillatory phenomenon in the concentration levels of the molecule of interest. The main objective of the study is to model a high frequency biochemical <span class="hlt">oscillator</span>, along with the investigations to identify and determine the parameters that affect the period of the <span class="hlt">oscillations</span>. The investigations entail and highlight the design of the reserve unit, a reservoir of the molecule of interest, as a key factor in realizing a high frequency <span class="hlt">stable</span> biochemical <span class="hlt">oscillator</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080017928&hterms=oscillator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Doscillator','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080017928&hterms=oscillator&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Doscillator"><span>All-optical Photonic <span class="hlt">Oscillator</span> with High-Q Whispering Gallery Mode Resonators</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Savchenkov, Anatoliy A.; Matsko, Andrey B.; Strekalov, Dmitry; Mohageg, Makan; Iltchenko, Vladimir S.; Maleki, Lute</p> <p>2004-01-01</p> <p>We demonstrated low threshold optical photonic hyper-parametric <span class="hlt">oscillator</span> in a high-Q 10(exp 10) CaF2 whispering gallery mode resonator which generates <span class="hlt">stable</span> 8.5 GHz signal. The <span class="hlt">oscillations</span> result from the resonantly enhanced four wave mixing occurring due to Kerr nonlinearity of the material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11477765','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11477765"><span>A programmable <span class="hlt">ultra</span>-low noise X-band exciter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>MacMullen, A; Hoover, L R; Justice, R D; Callahan, B S</p> <p>2001-07-01</p> <p>A programmable <span class="hlt">ultra</span>-low noise X-band exciter has been developed using commercial off-the-shelf components. Its phase noise is more than 10 dB below the best available microwave synthesizers. It covers a 7% frequency band with 0.1-Hz resolution. The X-band output at +23 dBm is a combination of signals from an X-band sapphire-loaded cavity <span class="hlt">oscillator</span> (SLCO), a low noise UHF frequency synthesizer, and special-purpose frequency translation and up-conversion circuitry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcAau.127..603O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcAau.127..603O"><span>Parametric study of combustion <span class="hlt">oscillation</span> in a single-side expansion scramjet combustor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ouyang, Hao; Liu, Weidong; Sun, Mingbo</p> <p>2016-10-01</p> <p>As a promising candidate for future air-breathing systems, the viability and efficiency of scramjet propulsion is challenged by a variety of factors including the combustion <span class="hlt">oscillation</span> in scramjet combustor. A series of comparative experiments focusing on the combustion <span class="hlt">oscillation</span> issue has been carried out in the present work. The obtained experimental results show that as the global equivalence ratio increases, the combustion <span class="hlt">oscillation</span> becomes more regular and frequent which is the most intensive in the vicinity of the fuel jet and the periodic combustion <span class="hlt">oscillation</span> is more possible when the injectors and flame-holding cavity are mounted on the expansion-side wall. In order to avoid the combustion <span class="hlt">oscillation</span> in scramjet combustor, distributed injection scheme is an effective method which can induce two parts interacting <span class="hlt">stable</span> flame. In addition, the results reveal that the varying fuel including hydrogen, ethylene and kerosene with different chemical kinetics has a significant effect on the reaction process in scramjet combustor, which can result in <span class="hlt">stable</span> combustion, periodic <span class="hlt">oscillation</span> and failed ignition respectively on the same operating condition of this paper. We believe that the present work is helpful to the designing of scramjet propulsion device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986MiJo...29..111L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986MiJo...29..111L"><span><span class="hlt">Stable</span>, low cost SAW microwave transmitter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lau, K. F.; Yen, K. H.</p> <p>1986-06-01</p> <p>The design flexibility and application possibilities of surface acoustic wave (SAW) technology is discussed. When a highly <span class="hlt">stable</span>, AM-modulated transmitter is required, a SAW resonator can provide an <span class="hlt">oscillator</span> Q of up to 20,000 at 1 GHz. When FM modulation is required, the SAW delay line can provide a lower <span class="hlt">oscillator</span> Q, which represents the optimum tradeoff between frequency stability and FM modulability. The capabilities of SAW <span class="hlt">oscillators</span> are reviewed, and two example transmitters are presented. One transmitter operates at 1680 MHz and provides an AM-modulated signal. The second operates at the 400 to 406 MHz range and provides an FM-modulated output at one of six frequencies. SAW transmitters are suitable for applications where moderately high stability and low cost are key factors. With direct generation of signals at microwave frequencies and the flexibility of SAW <span class="hlt">oscillator</span> design, a wide range of performance characteristics can be achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5993476','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5993476"><span>Parity-time–symmetric optoelectronic <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2018-01-01</p> <p>An optoelectronic <span class="hlt">oscillator</span> (OEO) is a hybrid microwave and photonic system incorporating an amplified positive feedback loop to enable microwave <span class="hlt">oscillation</span> to generate a high-frequency and low–phase noise microwave signal. The low phase noise is ensured by the high Q factor of the feedback loop enabled by the use of a long and low-loss optical fiber. However, an OEO with a long fiber loop would have a small free spectral range, leading to a large number of closely spaced <span class="hlt">oscillation</span> modes. To ensure single-mode <span class="hlt">oscillation</span>, an ultranarrowband optical filter must be used, but such an optical filter is hard to implement and the stability is poor. Here, we use a novel concept to achieve single-mode <span class="hlt">oscillation</span> without using an ultranarrowband optical filter. The single-mode operation is achieved based on parity-time (PT) symmetry by using two identical feedback loops, with one having a gain and the other having a loss of the same magnitude. The operation is analyzed theoretically and verified by an experiment. <span class="hlt">Stable</span> single-mode <span class="hlt">oscillation</span> at an ultralow phase noise is achieved without the use of an ultranarrowband optical filter. The use of PT symmetry in an OEO overcomes the long-existing mode-selection challenge that would greatly simplify the implementation of OEOs for ultralow–phase noise microwave generation. PMID:29888325</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2065893','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2065893"><span>Stochastic Noise and Synchronisation during Dictyostelium Aggregation Make cAMP <span class="hlt">Oscillations</span> Robust</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, Jongrae; Heslop-Harrison, Pat; Postlethwaite, Ian; Bates, Declan G</p> <p>2007-01-01</p> <p><span class="hlt">Stable</span> and robust <span class="hlt">oscillations</span> in the concentration of adenosine 3′, 5′-cyclic monophosphate (cAMP) are observed during the aggregation phase of starvation-induced development in Dictyostelium discoideum. In this paper we use mathematical modelling together with ideas from robust control theory to identify two factors which appear to make crucial contributions to ensuring the robustness of these <span class="hlt">oscillations</span>. Firstly, we show that stochastic fluctuations in the molecular interactions play an important role in preserving <span class="hlt">stable</span> <span class="hlt">oscillations</span> in the face of variations in the kinetics of the intracellular network. Secondly, we show that synchronisation of the aggregating cells through the diffusion of extracellular cAMP is a key factor in ensuring robustness of the oscillatory waves of cAMP observed in Dictyostelium cell cultures to cell-to-cell variations. A striking and quite general implication of the results is that the robustness analysis of models of <span class="hlt">oscillating</span> biomolecular networks (circadian clocks, Ca2+ <span class="hlt">oscillations</span>, etc.) can only be done reliably by using stochastic simulations, even in the case where molecular concentrations are very high. PMID:17997595</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100039400','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100039400"><span>Differential Resonant Ring YIG Tuned <span class="hlt">Oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parrott, Ronald A.</p> <p>2010-01-01</p> <p>A differential SiGe <span class="hlt">oscillator</span> circuit uses a resonant ring-<span class="hlt">oscillator</span> topology in order to electronically tune the <span class="hlt">oscillator</span> over multi-octave bandwidths. The <span class="hlt">oscillator</span> s tuning is extremely linear, because the <span class="hlt">oscillator</span> s frequency depends on the magnetic tuning of a YIG sphere, whose resonant frequency is equal to a fundamental constant times the DC magnetic field. This extremely simple circuit topology uses two coupling loops connecting a differential pair of SiGe bipolar transistors into a feedback configuration using a YIG tuned filter creating a closed-loop ring <span class="hlt">oscillator</span>. SiGe device technology is used for this <span class="hlt">oscillator</span> in order to keep the transistor s 1/f noise to an absolute minimum in order to achieve minimum RF phase noise. The single-end resonant ring <span class="hlt">oscillator</span> currently has an advantage in fewer parts, but when the <span class="hlt">oscillation</span> frequency is greater than 16 GHz, the package s parasitic behavior couples energy to the sphere and causes holes and poor phase noise performance. This is because the coupling to the YIG is extremely low, so that the <span class="hlt">oscillator</span> operates at near the unloaded Q. With the differential resonant ring <span class="hlt">oscillator</span>, the <span class="hlt">oscillation</span> currents are just in the YIG coupling mechanisms. The phase noise is even better, and the physical size can be reduced to permit monolithic microwave integrated circuit <span class="hlt">oscillators</span>. This invention is a YIG tuned <span class="hlt">oscillator</span> circuit making use of a differential topology to simultaneously achieve an extremely broadband electronic tuning range and <span class="hlt">ultra</span>-low phase noise. As a natural result of its differential circuit topology, all reactive elements, such as tuning stubs, which limit tuning bandwidth by contributing excessive open loop phase shift, have been eliminated. The differential <span class="hlt">oscillator</span> s open-loop phase shift is associated with completely non-dispersive circuit elements such as the physical angle of the coupling loops, a differential loop crossover, and the high-frequency phase shift of the n</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20180002076','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20180002076"><span>Temperature <span class="hlt">Oscillations</span> in Loop Heat Pipes - A Revisit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ku, Jentung</p> <p>2018-01-01</p> <p>Three types of temperature <span class="hlt">oscillation</span> have been observed in the loop heat pipes. The first type is an <span class="hlt">ultra</span>-high frequency temperature <span class="hlt">oscillation</span> with a period on the order of seconds or less. This type of temperature <span class="hlt">oscillation</span> is of little significance in spacecraft thermal control because the amplitude is in the noise level. The second type is a high frequency, low amplitude temperature <span class="hlt">oscillation</span> with a period on the order of seconds to minutes and an amplitude on the order of one Kelvin. It is caused by the back-and-forth movement of the vapor front near the inlet or outlet of the condenser. The third type is a low frequency, high amplitude <span class="hlt">oscillation</span> with a period on the order of hours and an amplitude on the order of tens of Kelvin. It is caused by the modulation of the net heat load into the evaporator by the attached large thermal mass which absorbs and releases energy alternately. Several papers on LHP temperature <span class="hlt">oscillation</span> have been published. This paper presents a further study on the underlying physical processes during the LHP temperature <span class="hlt">oscillation</span>, with an emphasis on the third type of temperature <span class="hlt">oscillation</span>. Specifically, equations governing the thermal and hydraulic behaviors of LHP operation will be used to describe interactions among LHP components, heat source, and heat sink. The following sequence of events and their interrelationship will also be explored: 1) maxima and minima of reservoir and thermal mass temperatures; 2) the range of the vapor front movement inside the condenser; 3) rates of change of the reservoir and thermal mass temperatures; 4) the rate of heat absorption and heat release by the thermal mass and the rate of vapor front movement; and 5) inflection points of the reservoir and thermal mass temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28468435','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28468435"><span>Longitudinal mode selection in a delay-line homogeneously broadened <span class="hlt">oscillator</span> with a fast saturable amplifier.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fleyer, Michael; Horowitz, Moshe</p> <p>2017-05-01</p> <p>Homogeneously broadened delay-line <span class="hlt">oscillators</span> such as lasers or optoelectronic <span class="hlt">oscillators</span> (OEOs) can potentially <span class="hlt">oscillate</span> in a large number of cavity modes that are supported by their amplifier bandwidth. In a continuous wave operating mode, the <span class="hlt">oscillating</span> mode is selected between one or few cavity modes that experience the highest small-signal gain. In this manuscript, we show that the <span class="hlt">oscillation</span> mode of a homogeneously broadened <span class="hlt">oscillator</span> can be selected from a large number of modes in a frequency region that can be broader than the full width at half maximum of the effective cavity filter. The mode is selected by a short-time injection of an external signal into the <span class="hlt">oscillator</span>. After the external signal is turned off, the <span class="hlt">oscillation</span> is maintained in the selected mode even if this mode has a significantly lower small-signal gain than that of other cavity modes. The stability of the <span class="hlt">oscillation</span> is obtained due to nonlinear saturation effect in the <span class="hlt">oscillator</span> amplifier. We demonstrate, experimentally and theoretically, mode selection in a long cavity OEO. We could select any desired mode between 400 cavity modes while maintaining <span class="hlt">ultra</span>-low phase noise in the selected mode and in the non-<span class="hlt">oscillating</span> modes. No mode-hopping was observed during our maximum measurement duration of about 24 hours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.G11B0708C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.G11B0708C"><span>Strategy to minimize the impact of the South Atlantic Anomaly effect on the DORIS station position estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Capdeville, H.; Moreaux, G.; Lemoine, J. M.</p> <p>2017-12-01</p> <p>All the <span class="hlt">Ultra</span> <span class="hlt">Stable</span> <span class="hlt">Oscillators</span> (<span class="hlt">USO</span>) of DORIS satellites are more or less sensitive to the South Atlantic Anomaly (SAA) effect. For Jason-1 and SPOT-5 satellites, a corrective model has been developed and used for the realization of the ITRF2014. However, Jason-2 is also impacted, not at the same level as Jason-1 but strong enough to worsen the multi-satellite solution provided for ITRF2014 for the SAA stations. The last DORIS satellites are also impacted by the SAA effect, in particular Jason-3. Thanks to the extremely precise time-tagging of the T2L2 experiment on-board Jason-2, A. Belli and the GEOAZUR team managed to draw up a model that accurately represents the variations of Jason-2 <span class="hlt">USO</span>'s frequency. This model will be evaluated by analyzing its impact on the position estimation of the SAA stations. While awaiting a DORIS data corrective model for the others satellites Jason-3 and Sentinel-3A, we propose here different strategies to minimize the SAA effect on the orbit and also and in particular on the station position estimation. We will compare the DORIS positions of the SAA stations with the GNSS positions collocated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4643801','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4643801"><span>Control of coupled <span class="hlt">oscillator</span> networks with application to microgrid technologies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Skardal, Per Sebastian; Arenas, Alex</p> <p>2015-01-01</p> <p>The control of complex systems and network-coupled dynamical systems is a topic of vital theoretical importance in mathematics and physics with a wide range of applications in engineering and various other sciences. Motivated by recent research into smart grid technologies, we study the control of synchronization and consider the important case of networks of coupled phase <span class="hlt">oscillators</span> with nonlinear interactions—a paradigmatic example that has guided our understanding of self-organization for decades. We develop a method for control based on identifying and stabilizing problematic <span class="hlt">oscillators</span>, resulting in a <span class="hlt">stable</span> spectrum of eigenvalues, and in turn a linearly <span class="hlt">stable</span> synchronized state. The amount of control, that is, number of <span class="hlt">oscillators</span>, required to stabilize the network is primarily dictated by the coupling strength, dynamical heterogeneity, and mean degree of the network, and depends little on the structural heterogeneity of the network itself. PMID:26601231</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18430413','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18430413"><span>Investigations on the heat transport capability of a cryogenic <span class="hlt">oscillating</span> heat pipe and its application in achieving <span class="hlt">ultra</span>-fast cooling rates for cell vitrification cryopreservation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Han, Xu; Ma, Hongbin; Jiao, Anjun; Critser, John K</p> <p>2008-06-01</p> <p>Theoretically, direct vitrification of cell suspensions with relatively low concentrations ( approximately 1 M) of permeating cryoprotective agents (CPA) is suitable for cryopreservation of almost all cell types and can be accomplished by <span class="hlt">ultra</span>-fast cooling rates that are on the order of 10(6-7) K/min. However, the methods and devices currently available for cell cryopreservation cannot achieve such high cooling rates. In this study, we constructed a novel cryogenic <span class="hlt">oscillating</span> heat pipe (COHP) using liquid nitrogen as its working fluid and investigated its heat transport capability to assess its application for achieving <span class="hlt">ultra</span>-fast cooling rates for cell cryopreservation. The experimental results showed that the apparent heat transfer coefficient of the COHP can reach 2 x 10(5) W/m(2).K, which is two orders of the magnitude higher than traditional heat pipes. Theoretical analyzes showed that the average local heat transfer coefficient in the thin film evaporation region of the COHP can reach 1.2 x 10(6) W/m(2).K, which is approximately 10(3) times higher than that achievable with standard pool-boiling approaches. Based on these results, a novel device design applying the COHP and microfabrication techniques is proposed and its efficiency for cell vitrification is demonstrated through numerical simulation. The estimated average cooling rates achieved through this approach is 10(6-7)K/min, which is much faster than the currently available methods and sufficient for achieving vitrification with relatively low concentrations of CPA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2888267','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2888267"><span>Investigations on the heat transport capability of a cryogenic <span class="hlt">oscillating</span> heat pipe and its application in achieving <span class="hlt">ultra</span>-fast cooling rates for cell vitrification cryopreservation☆</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Han, Xu; Ma, Hongbin; Jiao, Anjun; Critser, John K.</p> <p>2010-01-01</p> <p>Theoretically, direct vitrification of cell suspensions with relatively low concentrations (~1 M) of permeating cryoprotective agents (CPA) is suitable for cryopreservation of almost all cell types and can be accomplished by <span class="hlt">ultra</span>-fast cooling rates that are on the order of 106–7 K/min. However, the methods and devices currently available for cell cryopreservation cannot achieve such high cooling rates. In this study, we constructed a novel cryogenic <span class="hlt">oscillating</span> heat pipe (COHP) using liquid nitrogen as its working fluid and investigated its heat transport capability to assess its application for achieving <span class="hlt">ultra</span>-fast cooling rates for cell cryopreservation. The experimental results showed that the apparent heat transfer coefficient of the COHP can reach 2 × 105 W/m2·K, which is two orders of the magnitude higher than traditional heat pipes. Theoretical analyzes showed that the average local heat transfer coefficient in the thin film evaporation region of the COHP can reach 1.2 × 106 W/m2·K, which is approximately 103 times higher than that achievable with standard pool-boiling approaches. Based on these results, a novel device design applying the COHP and microfabrication techniques is proposed and its efficiency for cell vitrification is demonstrated through numerical simulation. The estimated average cooling rates achieved through this approach is 106–7 K/min, which is much faster than the currently available methods and sufficient for achieving vitrification with relatively low concentrations of CPA. PMID:18430413</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23455142','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23455142"><span>High-speed microwave photonic switch for millimeter-wave <span class="hlt">ultra</span>-wideband signal generation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Li Xian; Li, Wei; Zheng, Jian Yu; Wang, Hui; Liu, Jian Guo; Zhu, Ning Hua</p> <p>2013-02-15</p> <p>We propose a scheme for generating millimeter-wave (MMW) <span class="hlt">ultra</span>-wideband (UWB) signal that is free from low-frequency components and a residual local <span class="hlt">oscillator</span>. The system consists of two cascaded polarization modulators and is equivalent to a high-speed microwave photonic switch, which truncates a sinusoidal MMW into short pulses. The polarity switchability of the generated MMW-UWB pulse is also demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18764617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18764617"><span>Solvable model for chimera states of coupled <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abrams, Daniel M; Mirollo, Rennie; Strogatz, Steven H; Wiley, Daniel A</p> <p>2008-08-22</p> <p>Networks of identical, symmetrically coupled <span class="hlt">oscillators</span> can spontaneously split into synchronized and desynchronized subpopulations. Such chimera states were discovered in 2002, but are not well understood theoretically. Here we obtain the first exact results about the stability, dynamics, and bifurcations of chimera states by analyzing a minimal model consisting of two interacting populations of <span class="hlt">oscillators</span>. Along with a completely synchronous state, the system displays <span class="hlt">stable</span> chimeras, breathing chimeras, and saddle-node, Hopf, and homoclinic bifurcations of chimeras.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26193523','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26193523"><span>Wavelength-agile near-IR optical parametric <span class="hlt">oscillator</span> using a deposited silicon waveguide.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Ke-Yao; Foster, Mark A; Foster, Amy C</p> <p>2015-06-15</p> <p>Using a deposited hydrogenated amorphous silicon (a-Si:H) waveguide, we demonstrate <span class="hlt">ultra</span>-broad bandwidth (60 THz) parametric amplification via four-wave mixing (FWM), and subsequently achieve the first silicon optical parametric <span class="hlt">oscillator</span> (OPO) at near-IR wavelengths. Utilization of the time-dispersion-tuned technique provides an optical source with active wavelength tuning over 42 THz with a fixed pump wave.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2000380','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2000380"><span>In vivo mouse inferior olive neurons exhibit heterogeneous subthreshold <span class="hlt">oscillations</span> and spiking patterns</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Khosrovani, S.; Van Der Giessen, R. S.; De Zeeuw, C. I.; De Jeu, M. T. G.</p> <p>2007-01-01</p> <p>In vitro whole-cell recordings of the inferior olive have demonstrated that its neurons are electrotonically coupled and have a tendency to <span class="hlt">oscillate</span>. However, it remains to be shown to what extent subthreshold <span class="hlt">oscillations</span> do indeed occur in the inferior olive in vivo and whether its spatiotemporal firing pattern may be dynamically generated by including or excluding different types of oscillatory neurons. Here, we did whole-cell recordings of olivary neurons in vivo to investigate the relation between their subthreshold activities and their spiking behavior in an intact brain. The vast majority of neurons (85%) showed subthreshold oscillatory activities. The frequencies of these subthreshold <span class="hlt">oscillations</span> were used to distinguish four main olivary subtypes by statistical means. Type I showed both sinusoidal subthreshold <span class="hlt">oscillations</span> (SSTOs) and low-threshold Ca2+ <span class="hlt">oscillations</span> (LTOs) (16%); type II showed only sinusoidal subthreshold <span class="hlt">oscillations</span> (13%); type III showed only low-threshold Ca2+ <span class="hlt">oscillations</span> (56%); and type IV did not reveal any subthreshold <span class="hlt">oscillations</span> (15%). These subthreshold <span class="hlt">oscillation</span> frequencies were strongly correlated with the frequencies of preferred spiking. The frequency characteristics of the subthreshold <span class="hlt">oscillations</span> and spiking behavior of virtually all olivary neurons were <span class="hlt">stable</span> throughout the recordings. However, the occurrence of spontaneous or evoked action potentials modified the subthreshold <span class="hlt">oscillation</span> by resetting the phase of its peak toward 90°. Together, these findings indicate that the inferior olive in intact mammals offers a rich repertoire of different neurons with relatively <span class="hlt">stable</span> frequency settings, which can be used to generate and reset temporal firing patterns in a dynamically coupled ensemble. PMID:17895389</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9147E..7WB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9147E..7WB"><span><span class="hlt">Stable</span> Imaging for Astronomy (SIA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beaulieu, Mathilde; Ottogalli, Sebastien; Preis, Olivier; Bresson, Yves; Rivet, Jean-Pierre; Abe, Lyu; Vakili, Farrokh</p> <p>2014-07-01</p> <p>One of the most challenging fields of astronomical instrumentation is probably high-contrast imaging since it ultimately combines <span class="hlt">ultra</span>-high sensitivity at low flux and the ability to cope with photon flux contrasts of several hundreds of millions or even more. These two aspects implicitly require that high-contrast instruments should be highly <span class="hlt">stable</span> in the sense of the reproducibility of their measurements at different times, but also, continuously <span class="hlt">stable</span> over time. In most high contrast instruments or experiments, their sensitivity is broken after at most tens of minutes of operation due to uncontrolled and unknown behaviour of the whole experiment regarding the environmental conditions. In this paper, we introduce a general approach of an exhaustive stability study for high-contrast imaging that has been initiated at Lagrange Laboratory, Observatoire de la Côte d'Azur (OCA). On a practical ground, one of the fundamental issues of this study is the metrology, which is the basis of all reproducible measurements. We describe a small experiment designed to understand the behaviour of one of our <span class="hlt">ultra</span>-precise metrology tools (a commercial sub-nanometric 3-way interferometer) and derive the conditions under which its operation delivers reliable results. The approach will apply to the high-contrast imaging test-bench SPEED, under development at OCA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA604165','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA604165"><span>Probing Many-Body Interactions in an Optical Lattice Clock (Preprint)</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-10-23</p> <p>impressive potential gain over their microwave counterparts. Optical frequencies on the other hand are very difficult to measure, as the <span class="hlt">oscillations</span> ...source can be compared. Here, the laboratory radiation source is an <span class="hlt">ultra-stable</span> continuous-wave laser. It acts as the local <span class="hlt">oscillator</span> (or pendulum...where φ Z 0 is the ground longitudinal mode in a lattice site and φn are transverse harmonic <span class="hlt">oscillator</span> eigenmodes. ĉ†αn creates a fermion in mode n</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010Chaos..20d3104E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010Chaos..20d3104E"><span>Hyperbolic chaos in the klystron-type microwave vacuum tube <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emel'yanov, V. V.; Kuznetsov, S. P.; Ryskin, N. M.</p> <p>2010-12-01</p> <p>The ring-loop <span class="hlt">oscillator</span> consisting of two coupled klystrons which is capable of generating hyperbolic chaotic signal in the microwave band is considered. The system of delayed-differential equations describing the dynamics of the <span class="hlt">oscillator</span> is derived. This system is further reduced to the two-dimensional return map under the assumption of the instantaneous build-up of <span class="hlt">oscillations</span> in the cavities. The results of detailed numerical simulation for both models are presented showing that there exists large enough range of control parameters where the sustained regime corresponds to the structurally <span class="hlt">stable</span> hyperbolic chaos.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19126484','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19126484"><span>A compensated multi-pole linear ion trap mercury frequency standard for <span class="hlt">ultra-stable</span> timekeeping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Burt, Eric A; Diener, William A; Tjoelker, Robert L</p> <p>2008-12-01</p> <p>The multi-pole linear ion trap frequency standard (LITS) being developed at the Jet Propulsion Laboratory (JPL) has demonstrated excellent short- and long-term stability. The technology has now demonstrated long-term field operation providing a new capability for timekeeping standards. Recently implemented enhancements have resulted in a record line Q of 5 x 10(12) for a room temperature microwave atomic transition and a short-term fractional frequency stability of 5 x 10(-14)/tau(1/2). A scheme for compensating the second order Doppler shift has led to a reduction of the combined sensitivity to the primary LITS systematic effects below 5 x 10(-17) fractional frequency. Initial comparisons to JPL's cesium fountain clock show a systematic floor of less than 2 x 10(-16). The compensated multi-pole LITS at JPL was operated continuously and unattended for a 9-mo period from October 2006 to July 2007. During that time it was used as the frequency reference for the JPL geodetic receiver known as JPLT, enabling comparisons to any clock used as a reference for an International GNSS Service (IGS) site. Comparisons with the laser-cooled primary frequency standards that reported to the Bureau International des Poids et Mesures (BIPM) over this period show a frequency deviation less than 2.7 x 10(-17)/day. In the capacity of a stand-alone <span class="hlt">ultra-stable</span> flywheel, such a standard could be invaluable for long-term timekeeping applications in metrology labs while its methodology and robustness make it ideal for space applications as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080008631','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080008631"><span>Tone based command system for reception of very weak signals</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bokulic, Robert Steven (Inventor); Jensen, James Robert (Inventor)</p> <p>2006-01-01</p> <p>This disclosure presents a communication receiver system for spacecraft that includes an open loop receiver adapted to receive a communication signal. An ultrastable <span class="hlt">oscillator</span> (<span class="hlt">USO</span>) and a tone detector are connected to the open loop receiver. The open loop receiver translates the communication signal to an intermediate frequency signal using a highly <span class="hlt">stable</span> reference frequency from the <span class="hlt">USO</span>. The tone detector extracts commands from the communication signal by evaluating the difference between tones of the communication signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3089610','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3089610"><span>Emergent <span class="hlt">Oscillations</span> in Networks of Stochastic Spiking Neurons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Drongelen, Wim; Cowan, Jack D.</p> <p>2011-01-01</p> <p>Networks of neurons produce diverse patterns of <span class="hlt">oscillations</span>, arising from the network's global properties, the propensity of individual neurons to <span class="hlt">oscillate</span>, or a mixture of the two. Here we describe noisy limit cycles and quasi-cycles, two related mechanisms underlying emergent <span class="hlt">oscillations</span> in neuronal networks whose individual components, stochastic spiking neurons, do not themselves <span class="hlt">oscillate</span>. Both mechanisms are shown to produce gamma band <span class="hlt">oscillations</span> at the population level while individual neurons fire at a rate much lower than the population frequency. Spike trains in a network undergoing noisy limit cycles display a preferred period which is not found in the case of quasi-cycles, due to the even faster decay of phase information in quasi-cycles. These <span class="hlt">oscillations</span> persist in sparsely connected networks, and variation of the network's connectivity results in variation of the <span class="hlt">oscillation</span> frequency. A network of such neurons behaves as a stochastic perturbation of the deterministic Wilson-Cowan equations, and the network undergoes noisy limit cycles or quasi-cycles depending on whether these have limit cycles or a weakly <span class="hlt">stable</span> focus. These mechanisms provide a new perspective on the emergence of rhythmic firing in neural networks, showing the coexistence of population-level <span class="hlt">oscillations</span> with very irregular individual spike trains in a simple and general framework. PMID:21573105</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27080464','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27080464"><span>Sex Difference in Draft-Legal <span class="hlt">Ultra</span>-Distance Events - A Comparison between <span class="hlt">Ultra</span>-Swimming and <span class="hlt">Ultra</span>-Cycling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Salihu, Lejla; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat</p> <p>2016-04-30</p> <p>/h) were 32.1% faster (P < 0.05) than the three fastest female cyclists ever (34.7 km/h) (mean 34.70 ± 1.87 km/h). In summary, in draft-legal <span class="hlt">ultra</span>-distance events such as swimming and cycling, the sex difference in the annual top and annual top three swimmers and cyclists decreased (i.e. non-linearly in swimmers and linearly in cyclists) over the years. The sex difference of the fastest athletes ever was smaller in swimming (1.5%) than in cycling (26.4%). This finding is different from reports about races where drafting was not possible or even prohibited and where the sex difference remained <span class="hlt">stable</span> over years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatSR...745909R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatSR...745909R"><span>Basin stability measure of different steady states in coupled <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rakshit, Sarbendu; Bera, Bidesh K.; Majhi, Soumen; Hens, Chittaranjan; Ghosh, Dibakar</p> <p>2017-04-01</p> <p>In this report, we investigate the stabilization of saddle fixed points in coupled <span class="hlt">oscillators</span> where individual <span class="hlt">oscillators</span> exhibit the saddle fixed points. The coupled <span class="hlt">oscillators</span> may have two structurally different types of suppressed states, namely amplitude death and <span class="hlt">oscillation</span> death. The stabilization of saddle equilibrium point refers to the amplitude death state where <span class="hlt">oscillations</span> are ceased and all the <span class="hlt">oscillators</span> converge to the single <span class="hlt">stable</span> steady state via inverse pitchfork bifurcation. Due to multistability features of <span class="hlt">oscillation</span> death states, linear stability theory fails to analyze the stability of such states analytically, so we quantify all the states by basin stability measurement which is an universal nonlocal nonlinear concept and it interplays with the volume of basins of attractions. We also observe multi-clustered <span class="hlt">oscillation</span> death states in a random network and measure them using basin stability framework. To explore such phenomena we choose a network of coupled Duffing-Holmes and Lorenz <span class="hlt">oscillators</span> which are interacting through mean-field coupling. We investigate how basin stability for different steady states depends on mean-field density and coupling strength. We also analytically derive stability conditions for different steady states and confirm by rigorous bifurcation analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4588506','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4588506"><span>Proposal for a Domain Wall Nano-<span class="hlt">Oscillator</span> driven by Non-uniform Spin Currents</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sharma, Sanchar; Muralidharan, Bhaskaran; Tulapurkar, Ashwin</p> <p>2015-01-01</p> <p>We propose a new mechanism and a related device concept for a robust, magnetic field tunable radio-frequency (rf) <span class="hlt">oscillator</span> using the self <span class="hlt">oscillation</span> of a magnetic domain wall subject to a uniform static magnetic field and a spatially non-uniform vertical dc spin current. The self <span class="hlt">oscillation</span> of the domain wall is created as it translates periodically between two unstable positions, one being in the region where both the dc spin current and the magnetic field are present, and the other, being where only the magnetic field is present. The vertical dc spin current pushes it away from one unstable position while the magnetic field pushes it away from the other. We show that such <span class="hlt">oscillations</span> are <span class="hlt">stable</span> under noise and can exhibit a quality factor of over 1000. A domain wall under dynamic translation, not only being a source for rich physics, is also a promising candidate for advancements in nanoelectronics with the actively researched racetrack memory architecture, digital and analog switching paradigms as candidate examples. Devising a <span class="hlt">stable</span> rf <span class="hlt">oscillator</span> using a domain wall is hence another step towards the realization of an all domain wall logic scheme. PMID:26420544</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013113','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013113"><span>Microwave <span class="hlt">Oscillators</span> Based on Nonlinear WGM Resonators</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maleki, Lute; Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry</p> <p>2006-01-01</p> <p>Optical <span class="hlt">oscillators</span> that exploit resonantly enhanced four-wave mixing in nonlinear whispering-gallery-mode (WGM) resonators are under investigation for potential utility as low-power, <span class="hlt">ultra</span>-miniature sources of <span class="hlt">stable</span>, spectrally pure microwave signals. There are numerous potential uses for such <span class="hlt">oscillators</span> in radar systems, communication systems, and scientific instrumentation. The resonator in an <span class="hlt">oscillator</span> of this type is made of a crystalline material that exhibits cubic Kerr nonlinearity, which supports the four-photon parametric process also known as four-wave mixing. The <span class="hlt">oscillator</span> can be characterized as all-optical in the sense that the entire process of generation of the microwave signal takes place within the WGM resonator. The resonantly enhanced four-wave mixing yields coherent, phase-modulated optical signals at frequencies governed by the resonator structure. The frequency of the phase-modulation signal, which is in the microwave range, equals the difference between the frequencies of the optical signals; hence, this frequency is also governed by the resonator structure. Hence, further, the microwave signal is <span class="hlt">stable</span> and can be used as a reference signal. The figure schematically depicts the apparatus used in a proof-of-principle experiment. Linearly polarized pump light was generated by an yttrium aluminum garnet laser at a wavelength of 1.32 microns. By use of a 90:10 fiber-optic splitter and optical fibers, some of the laser light was sent into a delay line and some was transmitted to one face of glass coupling prism, that, in turn, coupled the laser light into a crystalline CaF2 WGM disk resonator that had a resonance quality factor (Q) of 6x10(exp 9). The output light of the resonator was collected via another face of the coupling prism and a single-mode optical fiber, which transmitted the light to a 50:50 fiber-optic splitter. One output of this splitter was sent to a slow photodiode to obtain a DC signal for locking the laser to a particular</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22913273','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22913273"><span>Induction of slow <span class="hlt">oscillations</span> by rhythmic acoustic stimulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ngo, Hong-Viet V; Claussen, Jens C; Born, Jan; Mölle, Matthias</p> <p>2013-02-01</p> <p>Slow <span class="hlt">oscillations</span> are electrical potential <span class="hlt">oscillations</span> with a spectral peak frequency of ∼0.8 Hz, and hallmark the electroencephalogram during slow-wave sleep. Recent studies have indicated a causal contribution of slow <span class="hlt">oscillations</span> to the consolidation of memories during slow-wave sleep, raising the question to what extent such <span class="hlt">oscillations</span> can be induced by external stimulation. Here, we examined whether slow <span class="hlt">oscillations</span> can be effectively induced by rhythmic acoustic stimulation. Human subjects were examined in three conditions: (i) with tones presented at a rate of 0.8 Hz ('0.8-Hz stimulation'); (ii) with tones presented at a random sequence ('random stimulation'); and (iii) with no tones presented in a control condition ('sham'). Stimulation started during wakefulness before sleep and continued for the first ∼90 min of sleep. Compared with the other two conditions, 0.8-Hz stimulation significantly delayed sleep onset. However, once sleep was established, 0.8-Hz stimulation significantly increased and entrained endogenous slow <span class="hlt">oscillation</span> activity. Sleep after the 90-min period of stimulation did not differ between the conditions. Our data show that rhythmic acoustic stimulation can be used to effectively enhance slow <span class="hlt">oscillation</span> activity. However, the effect depends on the brain state, requiring the presence of <span class="hlt">stable</span> non-rapid eye movement sleep. © 2012 European Sleep Research Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......390B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......390B"><span><span class="hlt">Ultra</span>-Low Loss Waveguides with Application to Photonic Integrated Circuits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauters, Jared F.</p> <p></p> <p>The integration of photonic components using a planar platform promises advantages in cost, size, weight, and power consumption for optoelectronic systems. Yet, the typical propagation loss of 5-10 dB/m in a planar silica waveguide is nearly five orders-of-magnitude larger than that in low loss optical fibers. For some applications, the miniaturization of the photonic system and resulting smaller propagation lengths from integration are enough to overcome the increase in propagation loss. For other more demanding systems or applications, such as those requiring long optical time delays or high-quality-factor (Q factor) resonators, the high propagation loss can degrade system performance to a degree that trumps the potential advantages offered by integration. Thus, the reduction of planar waveguide propagation loss in a Si3-N4 based waveguide platform is a primary focus of this dissertation. The <span class="hlt">ultra</span>-low loss stoichiometric Si3-N4 waveguide platform offers the additional advantages of fabrication process stability and repeatability. Yet, active devices such as lasers, amplifiers, and photodetectors have not been monolithically integrated with <span class="hlt">ultra</span>-low loss waveguides due to the incompatibility of the active and <span class="hlt">ultra</span>-low loss processing thermal budgets (<span class="hlt">ultra</span>-low loss waveguides are annealed at temperatures exceeding 1000 °C in order to drive out impurities). So a platform that enables the integration of active devices with the <span class="hlt">ultra</span>-low losses of the Si3- N4 waveguide platform is this dissertation's second focus. The work enables the future fabrication of sensor, gyroscope, true time delay, and low phase noise <span class="hlt">oscillator</span> photonic integrated circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800021182','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800021182"><span>Microwave tunable laser source: A <span class="hlt">stable</span>, precision tunable heterodyne local <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sachse, G. W.</p> <p>1980-01-01</p> <p>The development and capabilities of a tunable laser source utilizing a wideband electro-optic modulator and a CO2 laser are described. The precision tunability and high stability of the device are demonstrated with examples of laboratory spectroscopy. Heterodyne measurements are also presented to demonstrate the performance of the laser source as a heterodyne local <span class="hlt">oscillator</span>. With the use of five CO2 isotope lasers and the 8 to 18 GHz sideband offset tunability of the modulator, calculations indicate that 50 percent spectral coverage in the 9 to 12 micron region is achievable. The wavelength accuracy and stability of this laser source is limited by the CO2 laser and is more than adequate for the measurement of narrow Doppler-broadened line profiles. The room-temperature operating capability and the programmability of the microwave tunable laser source are attractive features for its in-the-field implementation. Although heterodyne measurements indicated some S/N degradation when using the device as a local <span class="hlt">oscillator</span>, there does not appear to be any fundamental limitation to the heterodyne efficiency of this laser source. Through the use of a lower noise-figure traveling wave tube amplifier and optical matching of the output beam with the photomixer, a substantial increase in the heterodyne S/N is expected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......242B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......242B"><span>Optically addressed <span class="hlt">ultra</span>-wideband phased antenna array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai, Jian</p> <p></p> <p>Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of <span class="hlt">ultra</span>-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled <span class="hlt">oscillators</span> (VCO) cannot provide a tunable range of several octaves, distribution of wideband local <span class="hlt">oscillator</span> signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides <span class="hlt">ultra</span>-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an <span class="hlt">ultra</span>-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23005797','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23005797"><span>Spin-<span class="hlt">oscillator</span> model for the unzipping of biomolecules by mechanical force.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prados, A; Carpio, A; Bonilla, L L</p> <p>2012-08-01</p> <p>A spin-<span class="hlt">oscillator</span> system models unzipping of biomolecules (such as DNA, RNA, or proteins) subject to an external force. The system comprises a macroscopic degree of freedom, represented by a one-dimensional <span class="hlt">oscillator</span>, and internal degrees of freedom, represented by Glauber spins with nearest-neighbor interaction and a coupling constant proportional to the <span class="hlt">oscillator</span> position. At a critical value F(c) of an applied external force F, the <span class="hlt">oscillator</span> rest position (order parameter) changes abruptly and the system undergoes a first-order phase transition. When the external force is cycled at different rates, the extension given by the <span class="hlt">oscillator</span> position exhibits a hysteresis cycle at high loading rates, whereas it moves reversibly over the equilibrium force-extension curve at very low loading rates. Under constant force, the logarithm of the residence time at the <span class="hlt">stable</span> and metastable <span class="hlt">oscillator</span> rest position is proportional to F-F(c) as in an Arrhenius law.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2294N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2294N"><span>Observations of decay-less low-amplitude kink <span class="hlt">oscillations</span> of EUV coronal loops</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nisticò, Giuseppe; Nakariakov, Valery; Anfinogentov, Sergey</p> <p></p> <p>The high spatial and temporal resolution observations at Extreme <span class="hlt">Ultra</span>-Violet (EUV) wavelengths from the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) reveal new features in kink <span class="hlt">oscillations</span> of coronal loops. We show that, in addition to the well-known rapidly decaying <span class="hlt">oscillations</span>, a new type of kink waves is present, characterized by low-amplitude and undamped <span class="hlt">oscillations</span>, that we define as decay-less. Typical periods range from 2.5 to 12 min in both regimes and are different for different loops, increasing with the loop length. Estimates of the loop lengths are supported by three dimensional reconstruction of the loop geometry. The amplitude for the decay-less regime is about 1 Mm, close to the spatial resolution of the AIA instruments. The <span class="hlt">oscillation</span> phase, measured by the cross-correlation method, is found to be constant along each analysed loop, and the spatial structure of the phase of the <span class="hlt">oscillations</span> corresponds to the fundamental standing kink mode. We show that the observed behaviours are consistent with the empirical model of a damped linear <span class="hlt">oscillator</span> excited by a continuous low-amplitude harmonic driver, in addition to an eventual impulsive high-amplitude driver. The observed life-time of the <span class="hlt">oscillations</span> is likely to be determined by the observational conditions rather than any physical damping. However, the balance between the driving and damping is a necessary ingredient of this model. The properties of this type of transverse <span class="hlt">oscillations</span> make them interesting object of study in the framework of resonant absorption theory and coronal heating process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23528158','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23528158"><span><span class="hlt">Ultra</span> low power consumption for self-<span class="hlt">oscillating</span> nanoelectromechanical systems constructed by contacting two nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barois, T; Ayari, A; Vincent, P; Perisanu, S; Poncharal, P; Purcell, S T</p> <p>2013-04-10</p> <p>We report here the observation of a new self-<span class="hlt">oscillation</span> mechanism in nanoelectromechanical systems (NEMS). A highly resistive nanowire was positioned to form a point-contact at a chosen vibration node of a silicon carbide nanowire resonator. Spontaneous and robust mechanical <span class="hlt">oscillations</span> arise when a sufficient DC voltage is applied between the two nanowires. An original model predicting the threshold voltage is used to estimate the piezoresistivity of the point-contact in agreement with the observations. The measured input power is in the pW-range which is the lowest reported value for such systems. The simplicity of the contacting procedure and the low power consumption open a new route for integrable and low-loss self-excited NEMS devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJWC.17702004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJWC.17702004M"><span>Possible Experiment for the Demonstration of Neutron Waves Interaction with Spatially <span class="hlt">Oscillating</span> Potential</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miloi, Mădălina Mihaela; Goryunov, Semyon; Kulin, German</p> <p>2018-04-01</p> <p>A wide range of problems in neutron optics is well described by a theory based on application of the effective potential model. It was assumed that the concept of the effective potential in neutron optics have a limited region of validity and ceases to be correct in the case of the giant acceleration of a matter. To test this hypothesis a new <span class="hlt">Ultra</span> Cold neutron experiment for the observation neutron interaction with potential structure <span class="hlt">oscillating</span> in space was proposed. The report is focused on the model calculations of the topography of sample surface that <span class="hlt">oscillate</span> in space. These calculations are necessary to find an optimal parameters and geometry of the planned experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LaPhy..28g5103H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LaPhy..28g5103H"><span>Stabilized single-longitudinal-mode erbium fibre laser employing silicon-micro-ring resonator and saturable absorber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Yung; Yeh, Chien-Hung; Chow, Chi-Wai; Chang, Yuan-Chia; Cheng, Hao-Yun</p> <p>2018-07-01</p> <p>In the paper, a wavelength-tunable erbium-doped fiber (EDF) ring laser with <span class="hlt">stable</span> single-longitudinal-mode (SLM) <span class="hlt">oscillation</span> is proposed and investigated. Here, a silicon-micro-ring-resonator can be applied in a laser cavity for tuning wavelength in the C-band range. To complete the SLM <span class="hlt">oscillation</span>, an unpumped EDF-based saturable absorber is used to act as <span class="hlt">ultra</span>-narrowband filter for suppressing other <span class="hlt">oscillation</span> modes. Additionally, the output stabilities of power and wavelength in the proposed EDF ring laser are also executed and discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26520826','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26520826"><span>Effect of vanadium contamination on the framework and micropore structure of <span class="hlt">ultra</span> <span class="hlt">stable</span> Y-zeolite.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Etim, U J; Xu, B; Ullah, Rooh; Yan, Z</p> <p>2016-02-01</p> <p>Y-zeolites are the main component of fluid catalytic cracking (FCC) catalyst for conversion of crude petroleum to products of high demand including transportation fuel. We investigated effects of vanadium which is present as one of the impurities in FCC feedstock on the framework and micropore structure of <span class="hlt">ultra-stable</span> (US) Y-zeolite. The zeolite samples were prepared and characterized using standard techniques including: (1) X-ray diffraction, (2) N2 adsorption employing non local density functional theory method, NLDFT, (3) Transmittance and Pyridine FTIR, (4) Transmittance electron microscopy (TEM), and (5) (27)Al and (29)Si MAS-NMR. Results revealed that in the presence of steam, vanadium caused excessive evolution of non inter-crystalline mesopores and structural damage. The evolved mesopore size averaged about 25.0nm at 0.5wt.% vanadium loading, far larger than mesopore size in zeolitic materials with improved hydrothermal stability and performance for FCC catalyst. A mechanism of mesopore formation based on accelerated dealumination has been proposed and discussed. Vanadium immobilization experiments conducted to mitigate vanadium migration into the framework clearly showed vanadium is mobile at reaction conditions. From the results, interaction of vanadium with the passivator limits and decreases mobility and activity of vanadium into inner cavities of the zeolite capable of causing huge structure breakdown and acid sites destruction. This study therefore deepens insight into the causes of alteration in activity and selectivity of vanadium contaminated catalyst and hints on a possible mechanism of passivation in vanadium passivated FCC catalyst. Copyright © 2015 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4330535','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4330535"><span>Delay-induced patterns in a two-dimensional lattice of coupled <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kantner, Markus; Schöll, Eckehard; Yanchuk, Serhiy</p> <p>2015-01-01</p> <p>We show how a variety of <span class="hlt">stable</span> spatio-temporal periodic patterns can be created in 2D-lattices of coupled <span class="hlt">oscillators</span> with non-homogeneous coupling delays. The results are illustrated using the FitzHugh-Nagumo coupled neurons as well as coupled limit cycle (Stuart-Landau) <span class="hlt">oscillators</span>. A “hybrid dispersion relation” is introduced, which describes the stability of the patterns in spatially extended systems with large time-delay. PMID:25687789</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23944538','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23944538"><span>Characterization of edge <span class="hlt">oscillation</span> in a traveling-wave field-effect transistor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Narahara, Koichi</p> <p>2013-07-01</p> <p>In this study, we characterize the <span class="hlt">oscillating</span> pulse edges developed in a traveling-wave field-effect transistor (TWFET). Recently, it has been found that a <span class="hlt">stable</span> shock front can develop on a TWFET, which can travel in one direction only. Once the reflected pulse edge at the far end is transmitted to the input, the shock front develops and begins to travel on the device again. This process establishes a permanent edge <span class="hlt">oscillation</span>. This paper discusses the device setup necessary to excite such <span class="hlt">oscillations</span> and how pulse edges <span class="hlt">oscillate</span> on a TWFET. By applying the phase reduction scheme to the transmission equations of a TWFET, we obtain phase sensitivity, which appropriately explains the measured spatial dependence of the locking range in frequency. Moreover, multiple <span class="hlt">oscillating</span> edges can develop simultaneously, which are mutually synchronized. The dynamics of these multiple edges are also described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4737961','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4737961"><span>Bright and <span class="hlt">ultra</span>-fast scintillation from a semiconductor?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Derenzo, Stephen E.; Bourret-Courshesne, Edith; Bizarri, Gregory; Canning, Andrew</p> <p>2015-01-01</p> <p>Semiconductor scintillators are worth studying because they include both the highest luminosities and shortest decay times of all known scintillators. Moreover, many semiconductors have the heaviest <span class="hlt">stable</span> elements (Tl, Hg, Pb, Bi) as a major constituent and a high ion pair yield that is proportional to the energy deposited. We review the scintillation properties of semiconductors activated by native defects, isoelectronic impurities, donors and acceptors with special emphasis on those that have exceptionally high luminosities (e.g. ZnO:Zn, ZnS:Ag,Cl, CdS:Ag,Cl) and those that have <span class="hlt">ultra</span>-fast decay times (e.g. ZnO:Ga; CdS:In). We discuss underlying mechanisms that are consistent with these properties and the possibilities for achieving (1) 200,000 photons/MeV and 1% fwhm energy resolution for 662 keV gamma rays, (2) <span class="hlt">ultra</span>-fast (ns) decay times and coincident resolving times of 30 ps fwhm for time-of-flight positron emission tomography, and (3) both a high luminosity and an <span class="hlt">ultra</span>-fast decay time from the same scintillator at cryogenic temperatures. PMID:26855462</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950020839','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950020839"><span>High-precision buffer circuit for suppression of regenerative <span class="hlt">oscillation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tripp, John S.; Hare, David A.; Tcheng, Ping</p> <p>1995-01-01</p> <p>Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, <span class="hlt">stable</span>, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative <span class="hlt">oscillation</span> and consequent rectification bias errors. <span class="hlt">Oscillation</span> suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior <span class="hlt">oscillation</span> suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative <span class="hlt">oscillation</span> occurring when typical shielded cable loads are driven.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PASJ...52.1067S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PASJ...52.1067S"><span><span class="hlt">Oscillations</span> of Static Discs around Schwarzschild Black Holes: Effect of Self-Gravitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Semerák, Oldřich; Žáček, Miroslav</p> <p>2000-12-01</p> <p>The <span class="hlt">oscillations</span> of accretion-disc matter about roughly circular motion may produce a quasi-periodic variation in the observed signal (Ipser 1996, AAA 65.067.047). They were studied theoretically on non-gravitating, test discs, in a pseudo-Newtonian manner as well as in general relativity, both in static and in stationary fields. The present paper shows how the radial profiles of <span class="hlt">oscillation</span> frequencies can be modified by the self-gravity of the disc. Exact superpositions of a Schwarzschild black hole with the Lemos and Letelier (1994, AAA 61.067.077) annular discs (static thin discs obtained by inversion of the first Morgan-Morgan solution) are considered to be simple (static) models of an accretion system. Both the epicyclic and perpendicular frequencies are plotted against the Schwarzschild radius, the circumferential radius, and the proper distance from the horizon. The curves indicate that in the innermost parts more massive discs are more <span class="hlt">stable</span> with respect to horizontal perturbations, whereas they are less <span class="hlt">stable</span> with respect to vertical perturbations. In the case of a sequence of discs interpretable as counter-rotating particles on <span class="hlt">stable</span> time-like circular geodesics and having their inner rims just on marginally <span class="hlt">stable</span> circular orbits, <span class="hlt">oscillations</span> of the inner parts get faster with increasing disc mass; the maximum of the epicyclic frequency, important for trapping of the low-frequency modes near the inner radius, moves to smaller radii and becomes somewhat higher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800035657&hterms=sea+ice+albedo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Bice%2Balbedo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800035657&hterms=sea+ice+albedo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Bice%2Balbedo"><span>Free <span class="hlt">oscillations</span> in a climate model with ice-sheet dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kallen, E.; Crafoord, C.; Ghil, M.</p> <p>1979-01-01</p> <p>A study of <span class="hlt">stable</span> periodic solutions to a simple nonlinear model of the ocean-atmosphere-ice system is presented. The model has two dependent variables: ocean-atmosphere temperature and latitudinal extent of the ice cover. No explicit dependence on latitude is considered in the model. Hence all variables depend only on time and the model consists of a coupled set of nonlinear ordinary differential equations. The globally averaged ocean-atmosphere temperature in the model is governed by the radiation balance. The reflectivity to incoming solar radiation, i.e., the planetary albedo, includes separate contributions from sea ice and from continental ice sheets. The major physical mechanisms active in the model are (1) albedo-temperature feedback, (2) continental ice-sheet dynamics and (3) precipitation-rate variations. The model has three-equilibrium solutions, two of which are linearly unstable, while one is linearly <span class="hlt">stable</span>. For some choices of parameters, the stability picture changes and sustained, finite-amplitude <span class="hlt">oscillations</span> obtain around the previously <span class="hlt">stable</span> equilibrium solution. The physical interpretation of these <span class="hlt">oscillations</span> points to the possibility of internal mechanisms playing a role in glaciation cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17014224','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17014224"><span><span class="hlt">Ultra</span>-high-frequency chaos in a time-delay electronic device with band-limited feedback.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Illing, Lucas; Gauthier, Daniel J</p> <p>2006-09-01</p> <p>We report an experimental study of <span class="hlt">ultra</span>-high-frequency chaotic dynamics generated in a delay-dynamical electronic device. It consists of a transistor-based nonlinearity, commercially-available amplifiers, and a transmission-line for feedback. The feedback is band-limited, allowing tuning of the characteristic time-scales of both the periodic and high-dimensional chaotic <span class="hlt">oscillations</span> that can be generated with the device. As an example, periodic <span class="hlt">oscillations</span> ranging from 48 to 913 MHz are demonstrated. We develop a model and use it to compare the experimentally observed Hopf bifurcation of the steady-state to existing theory [Illing and Gauthier, Physica D 210, 180 (2005)]. We find good quantitative agreement of the predicted and the measured bifurcation threshold, bifurcation type and <span class="hlt">oscillation</span> frequency. Numerical integration of the model yields quasiperiodic and high dimensional chaotic solutions (Lyapunov dimension approximately 13), which match qualitatively the observed device dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080048193','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080048193"><span><span class="hlt">Ultra-Stable</span> Beacon Source for Laboratory Testing of Optical Tracking</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Aso, Yoichi; Marka, Szabolcs; Kovalik, Joseph</p> <p>2008-01-01</p> <p>The <span class="hlt">ultra-stable</span> beacon source (USBS) provides a laser-beam output with a very low angular jitter and can be used as an absolute angular reference to simulate a beacon in the laboratory. The laser is mounted on the top of a very short (approximately equal to 1 m) inverted pendulum (IP) with its optical axis parallel to the carbon fiber pendulum leg. The 85-cm, carbon fiber rods making up the leg are very lightweight and rigid, and are supported by a flex-joint at the bottom (see figure). The gimbal-mounted laser is a weight-adjustable load of about 1.5 kg with its center of rotation co-located with the center of percussion of the inverted pendulum. This reduces the coupling of transverse motion at the base of the pendulum to angular motion of the laser at the top. The inverted pendulum is mounted on a gimbal with its center of rotation coinciding with the pivot position of the inverted pendulum flexure joint. This reduces coupling of ground tilt at the inverted pendulum base to motion of the laser mounted at the top. The mass of the top gimbal is adjusted to give the pendulum a very low resonant frequency (approximately equal to 10 mHz) that filters transverse seismic disturbances from the ground where the base is attached. The motion of the IP is monitored by an optical-lever sensor. The laser light is reflected by the mirror on the IP, and then is detected by a quadrant photo-detector (QPD). The position of the beam spot on the QPD corresponds to the tilt of the IP. Damping of this motion is provided by two coil and magnet pairs. The bottom gimbal mount consists of two plates. The IP is mounted on the second plate. The first plate is supported by two posts through needles and can be rotated about the axis connecting the tips of the needles. The second plate hangs from the first plate and can be rotated about the axis perpendicular to the first plate. As a result, the second plate acts as a two-axis rotation stage. Its center of rotation is located at the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10383E..0DG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10383E..0DG"><span>Complex delay dynamics of high power quantum cascade <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grillot, F.; Newell, T. C.; Gavrielides, A.; Carras, M.</p> <p>2017-08-01</p> <p>Quantum cascade lasers (QCL) have become the most suitable laser sources from the mid-infrared to the THz range. This work examines the effects of external feedback in different high power mid infrared QCL structures and shows that different conditions of the feedback wave can produce complex dynamics hence stabilization, destabilization into strong mode-competition or undamping nonlinear <span class="hlt">oscillations</span>. As a dynamical system, reinjection of light back into the cavity also can also provoke apparition of chaotic <span class="hlt">oscillations</span>, which must be avoided for a <span class="hlt">stable</span> operation both at mid-infrared and THz wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24125317','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24125317"><span>Robust synchronization of spin-torque <span class="hlt">oscillators</span> with an LCR load.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pikovsky, Arkady</p> <p>2013-09-01</p> <p>We study dynamics of a serial array of spin-torque <span class="hlt">oscillators</span> with a parallel inductor-capacitor-resistor (LCR) load. In a large range of parameters the fully synchronous regime, where all the <span class="hlt">oscillators</span> have the same state and the output field is maximal, is shown to be <span class="hlt">stable</span>. However, not always such a robust complete synchronization develops from a random initial state; in many cases nontrivial clustering is observed, with a partial synchronization resulting in a quasiperiodic or chaotic mean-field dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20180002925&hterms=Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20180002925&hterms=Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSolar"><span>Dawn- Dusk Auroral Oval <span class="hlt">Oscillations</span> Associated with High- Speed Solar Wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liou, Kan; Sibeck, David G.</p> <p>2018-01-01</p> <p>We report evidence of global-scale auroral oval <span class="hlt">oscillations</span> in the millihertz range, using global auroral images acquired from the Ultraviolet Imager on board the decommissioned Polar satellite and concurrent solar wind measurements. On the basis of two events (15 January 1999 and 6 January 2000) studied, it is found that (1) quasi-periodic auroral oval <span class="hlt">oscillations</span> (approximately 3 megahertz) can occur when solar wind speeds are high at northward or southward interplanetary magnetic field turning, (2) the <span class="hlt">oscillation</span> amplitudes range from a few to more than 10 degrees in latitudes, (3) the <span class="hlt">oscillation</span> frequency is the same for each event irrespective of local time and without any azimuthal phase shift (i.e., propagation), (4) the auroral <span class="hlt">oscillations</span> occur in phase within both the dawn and dusk sectors but 180 degrees out of phase between the dawn and dusk sectors, and (5) no micropulsations on the ground match the auroral <span class="hlt">oscillation</span> periods. While solar wind conditions favor the growth of the Kelvin-Helmholtz (K-H) instability on the magnetopause as often suggested, the observed wave characteristics are not consistent with predictions for K-H waves. The in-phase and out-of-phase features found in the dawn-dusk auroral oval <span class="hlt">oscillations</span> suggest that wiggling motions of the magnetotail associated with fast solar winds might be the direct cause of the global-scale millihertz auroral oval <span class="hlt">oscillations</span>. Plain Language Summary: We utilize global auroral image data to infer the motion of the magnetosphere and show, for the first time, the entire magnetospheric tail can move east-west in harmony like a windsock flapping in wind. The characteristic period of the flapping motion may be a major source of global long-period ULF (<span class="hlt">Ultra</span> Low Frequency) waves, adding an extra source of the global mode ULF waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhBio..10e6005D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhBio..10e6005D"><span>Analysis of precision in chemical <span class="hlt">oscillators</span>: implications for circadian clocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>d'Eysmond, Thomas; De Simone, Alessandro; Naef, Felix</p> <p>2013-10-01</p> <p>Biochemical reaction networks often exhibit spontaneous self-sustained <span class="hlt">oscillations</span>. An example is the circadian <span class="hlt">oscillator</span> that lies at the heart of daily rhythms in behavior and physiology in most organisms including humans. While the period of these <span class="hlt">oscillators</span> evolved so that it resonates with the 24 h daily environmental cycles, the precision of the <span class="hlt">oscillator</span> (quantified via the Q factor) is another relevant property of these cell-autonomous <span class="hlt">oscillators</span>. Since this quantity can be measured in individual cells, it is of interest to better understand how this property behaves across mathematical models of these <span class="hlt">oscillators</span>. Current theoretical schemes for computing the Q factors show limitations for both high-dimensional models and in the vicinity of Hopf bifurcations. Here, we derive low-noise approximations that lead to numerically <span class="hlt">stable</span> schemes also in high-dimensional models. In addition, we generalize normal form reductions that are appropriate near Hopf bifurcations. Applying our approximations to two models of circadian clocks, we show that while the low-noise regime is faithfully recapitulated, increasing the level of noise leads to species-dependent precision. We emphasize that subcomponents of the <span class="hlt">oscillator</span> gradually decouple from the core <span class="hlt">oscillator</span> as noise increases, which allows us to identify the subnetworks responsible for robust rhythms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.444..327S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.444..327S"><span>A <span class="hlt">stable</span> quasi-periodic 4.18-d <span class="hlt">oscillation</span> and mysterious occultations in the 2011 MOST light-curve of TW Hya</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siwak, Michal; Rucinski, Slavek M.; Matthews, Jaymie M.; Guenther, David B.; Kuschnig, Rainer; Moffat, Anthony F. J.; Rowe, Jason F.; Sasselov, Dimitar; Weiss, Werner W.</p> <p>2014-10-01</p> <p>We present an analysis of the 2011 photometric observations of TW Hya by the MOST satellite; this is the fourth continuous series of this type. The large-scale light variations are dominated by a strong, quasi-periodic 4.18-d <span class="hlt">oscillation</span> with superimposed, apparently chaotic flaring activity. The former is probably produced by stellar rotation with one large hotspot created by a <span class="hlt">stable</span> accretion funnel, while the latter may be produced by small hotspots, created at moderate latitudes by unstable accretion tongues. A new, previously unnoticed feature is a series of semiperiodic, well-defined brightness dips of unknown nature, of which 19 were observed during 43 d of our nearly continuous observations. Re-analysis of the 2009 MOST light-curve revealed the presence of three similar dips. On the basis of recent theoretical results, we tentatively conclude that the dips may represent occultations of the small hotspots created by unstable accretion tongues by hypothetical optically thick clumps of dust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16616118','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16616118"><span>Numerical investigations of transient heat transfer characteristics and vitrification tendencies in <span class="hlt">ultra</span>-fast cell cooling processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiao, Anjun; Han, Xu; Critser, John K; Ma, Hongbin</p> <p>2006-06-01</p> <p>During freezing, cells are often damaged directly or indirectly by ice formation. Vitrification is an alternative approach to cryopreservation that avoids ice formation. The common method to achieve vitrification is to use relatively high concentrations of cryoprotectant agents (CPA) in combination with a relatively slow cooling rate. However, high concentrations of CPAs have potentially damaging toxic and/or osmotic effects on cells. Therefore, establishing methods to achieve vitrification with lower concentrations of CPAs through <span class="hlt">ultra</span>-fast cooling rates would be advantageous in these aspects. These <span class="hlt">ultra</span>-fast cooling rates can be realized by a cooling system with an <span class="hlt">ultra</span>-high heat transfer coefficient (h) between the sample and coolant. The <span class="hlt">oscillating</span> motion heat pipe (OHP), a novel cooling device utilizing the pressure change to excite the <span class="hlt">oscillation</span> motion of the liquid plugs and vapor bubbles, can significantly increase h and may fulfill this aim. The current investigation was designed to numerically study the effects of different values of h on the transient heat transfer characteristics and vitrification tendencies of the cell suspension during the cooling processes in an <span class="hlt">ultra</span>-thin straw (100 microm in diameter). The transient temperature distribution, the cooling rate and the volume ratio (x) of the ice quantity to the maximum crystallizable ice of the suspension were calculated. From these numerical results, it is concluded that the <span class="hlt">ultra</span>-high h (>10(4) W/m2 K) obtained by OHPs could facilitate vitrification by efficiently decreasing x as well as the time to pass through the dangerous temperature region where the maximum ice formation happens. For comparison, OHPs can decrease both of the parameters to less than 20% of those from the widely used open pulled straw methods. Therefore, the OHP method will be a promising approach to improving vitrification tendencies of CPA solutions and could also decrease the required concentration of CPAs for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Ge%26Ae..57.1101S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Ge%26Ae..57.1101S"><span>Free <span class="hlt">Oscillations</span> of the Facula Node at the Stage of Slow Dissipation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Solov'ev, A. A.; Kirichek, E. A.; Efremov, V. I.</p> <p>2017-12-01</p> <p>A solar faculae having an appearance of quite long-lived magnetic nodes can perform (as well as sunspots, chromospheric filaments, coronal loops) free <span class="hlt">oscillations</span>, i.e., they can <span class="hlt">oscillate</span> about the <span class="hlt">stable</span> equilibrium position as a single whole, changing quasi-periodically magnetic field averaged over the section with periods from 1 to 4 hours. Kolotkov et al. (2017) described the case in which the average magnetic field strength of the facula node considerably decreased during observations of SDO magnetograms (13 hours), and, at the same time, its <span class="hlt">oscillations</span> acquired a specific character: the fundamental mode of free <span class="hlt">oscillations</span> of the facula considerably increased in amplitude (by approximately two times), while the period of <span class="hlt">oscillations</span> increased by three times. At the end of the process, the system dissipated. In this work, we present the exact solution of the equation of small-amplitude <span class="hlt">oscillations</span> of the system with a time-variable rigidity, describing the <span class="hlt">oscillation</span> behavior at which the elasticity of the system decreases with time, while the period and amplitude of <span class="hlt">oscillations</span> grow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSV...417...56P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSV...417...56P"><span>Multiple spatially localized dynamical states in friction-excited <span class="hlt">oscillator</span> chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Papangelo, A.; Hoffmann, N.; Grolet, A.; Stender, M.; Ciavarella, M.</p> <p>2018-03-01</p> <p>Friction-induced vibrations are known to affect many engineering applications. Here, we study a chain of friction-excited <span class="hlt">oscillators</span> with nearest neighbor elastic coupling. The excitation is provided by a moving belt which moves at a certain velocity vd while friction is modelled with an exponentially decaying friction law. It is shown that in a certain range of driving velocities, multiple <span class="hlt">stable</span> spatially localized solutions exist whose dynamical behavior (i.e. regular or irregular) depends on the number of <span class="hlt">oscillators</span> involved in the vibration. The classical non-repeatability of friction-induced vibration problems can be interpreted in light of those multiple <span class="hlt">stable</span> dynamical states. These states are found within a "snaking-like" bifurcation pattern. Contrary to the classical Anderson localization phenomenon, here the underlying linear system is perfectly homogeneous and localization is solely triggered by the friction nonlinearity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhFl...29c2005W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhFl...29c2005W"><span>Energy transfer and motion synchronization between mechanical <span class="hlt">oscillators</span> through microhydrodynamic coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wan, Yu; Jin, Kai; Ahmad, Talha J.; Black, Michael J.; Xu, Zhiping</p> <p>2017-03-01</p> <p>Fluidic environment is encountered for mechanical components in many circumstances, which not only damps the <span class="hlt">oscillation</span> but also modulates their dynamical behaviors through hydrodynamic interactions. In this study, we examine energy transfer and motion synchronization between two mechanical micro-<span class="hlt">oscillators</span> by performing thermal lattice-Boltzmann simulations. The coefficient of inter-<span class="hlt">oscillator</span> energy transfer is measured to quantify the strength of microhydrodynamic coupling, which depends on their distance and fluid properties such as density and viscosity. Synchronized motion of the <span class="hlt">oscillators</span> is observed in the simulations for typical parameter sets in relevant applications, with the formation and loss of <span class="hlt">stable</span> anti-phase synchronization controlled by the <span class="hlt">oscillating</span> frequency, amplitude, and hydrodynamic coupling strength. The critical ranges of key parameters to assure efficient energy transfer or highly synchronized motion are predicted. These findings could be used to advise mechanical design of passive and active devices that operate in fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112a3503P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112a3503P"><span>Synchronization of electrically coupled micromechanical <span class="hlt">oscillators</span> with a frequency ratio of 3:1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pu, Dong; Wei, Xueyong; Xu, Liu; Jiang, Zhuangde; Huan, Ronghua</p> <p>2018-01-01</p> <p>In this Letter, synchronization of micromechanical <span class="hlt">oscillators</span> with a frequency ratio of 3:1 is reported. Two electrically coupled piezoresistive micromechanical <span class="hlt">oscillators</span> are built for the study, and their <span class="hlt">oscillation</span> frequencies are tuned via the Joule heating effect to find out the synchronization region. Experimental results show that the larger coupling strength or bias driving voltage is applied and a wider synchronization region is obtained. Interestingly, however, the <span class="hlt">oscillator</span>'s frequency tunability is dramatically reduced from -809.1 Hz/V to -23.1 Hz/V when synchronization is reached. A nearly 10-fold improvement of frequency stability at 1 s is observed from one of the synchronized <span class="hlt">oscillators</span>, showing a comparable performance of the other. The <span class="hlt">stable</span> high order synchronization of micromechanical <span class="hlt">oscillators</span> is helpful to design high performance resonant sensors with a better frequency resolution and a larger scale factor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120000469','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120000469"><span><span class="hlt">Ultra</span>-Low-Dropout Linear Regulator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thornton, Trevor; Lepkowski, William; Wilk, Seth</p> <p>2011-01-01</p> <p>A radiation-tolerant, <span class="hlt">ultra</span>-low-dropout linear regulator can operate between -150 and 150 C. Prototype components were demonstrated to be performing well after a total ionizing dose of 1 Mrad (Si). Unlike existing components, the linear regulator developed during this activity is unconditionally <span class="hlt">stable</span> over all operating regimes without the need for an external compensation capacitor. The absence of an external capacitor reduces overall system mass/volume, increases reliability, and lowers cost. Linear regulators generate a precisely controlled voltage for electronic circuits regardless of fluctuations in the load current that the circuit draws from the regulator.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10102E..0XK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10102E..0XK"><span><span class="hlt">Ultra</span>-strong coupling with spin-split heavyhole cyclotron resonances in sGe QWs (Conference Presentation)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keller, Janine; Scalari, Giacomo; Maissen, Curdin; Paravicini-Bagliani, Gian Lorenzo; Haase, Johannes; Failla, Michele; Myronov, Maksym; Leadley, David R.; Lloyd-Hughes, James; Faist, Jérôme</p> <p>2017-02-01</p> <p>We study the <span class="hlt">ultra</span>-strong coupling (USC) of Landau level transitions in strained Germanium quantum wells (sGe QW) to THz metasurfaces. The spin-splitting of the heavy-hole cyclotron resonance in sGe QWs due to the Rashba spin-orbit interaction in magnetic field offers an excellent platform to investigate <span class="hlt">ultra</span>-strong coupling to a non-parabolic system. THz split ring resonators can be tuned to coincide with the single cyclotron transition (around 0.4 THz and a magnetic field of 1.5 T) or the spin-resolved transitions of the sGe QWs (at 1.3 THz and 4.5 T). Coupling to the single cyclotron yields a normalized USC rate of 25%, resulting from fitting with a Hopfield-like Hamiltonian model. Coupling to two or three cyclotron resonances in sGe QWs lead to the observation of multiple polaritons branches, one polariton branch for each <span class="hlt">oscillator</span> involved in the system. An adaption of the theory allows to also describe this multiple-<span class="hlt">oscillator</span> system and to determine the coupling strengths. The different Rabi-splittings for the multiple cyclotrons coupling to the same resonator mode relate to the underlying differences in the material. Furthermore, the visibility of an additional transition, possibly a light hole transition with very low carrier density, is strongly enhanced due to the coupling to the LC-resonance with a normalized strong coupling ratio of 4.7%. Future perspectives include controlling spin-flip transitions in USC and studying the impact of non-parabolicity on the <span class="hlt">ultra</span>-strong coupling physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25048985','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25048985"><span>Conjugated polymer dots for <span class="hlt">ultra-stable</span> full-color fluorescence patterning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Kaiwen; Liu, Zhihe; Chen, Haobin; Sheng, Lan; Zhang, Sean Xiao-An; Chiu, Daniel T; Yin, Shengyan; Wu, Changfeng; Qin, Weiping</p> <p>2014-11-12</p> <p><span class="hlt">Stable</span> full-color fluorescence patterning are achieved by multicolor polymer-dot inks. The fluorescent patterns show extraordinary stability upon various treatments, offering a superior combination of bright fluorescence, excellent photostability, chemical resistance, and eco-friendship. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ChA%26A..37....1X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ChA%26A..37....1X"><span>A Theoretical Probe for Excitation Mechanisms of Sun-like and Mira-like <span class="hlt">Oscillations</span> of Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Da-run; Deng, Li-cai</p> <p>2013-01-01</p> <p>The linear nonadiabatic <span class="hlt">oscillations</span> for evolutionary models of 0.6- 3M8 stars are calculated by using a nonlocal and time-dependent convection theory. The results show that in the HR diagram the pulsation-unstable low- temperature stars on the right side of instability strip can be divided into two groups. One group indicates the Sun-like <span class="hlt">oscillation</span> stars composed of the main- sequence dwarfs, sub-giants and red giants (RGs) of low and intermediate lu- minosities, which are unstable in the intermediate- and high-order (n ≥ 12) p- modes, and <span class="hlt">stable</span> in the low-order (n ≤ 5) p-modes. Another group indicates the Mira-like stars composed of the bright RGs and asymptotic giant branch (AGB) stars, which are just contrary to Sun-like stars, unstable in low-order (n ≤ 5) p-modes and <span class="hlt">stable</span> in the intermediate- and high-order (n ≥ 12) p-modes. The <span class="hlt">oscillations</span> for the red edge of Cepheid (δ Scuti) instability strip, Sun-like and Mira-like stars can be explained uniformly by the coupling between convection and <span class="hlt">oscillation</span> (CCO). For the low-temperature stars on the right side of in- stability strip, CCO is the dominant excitation and damping mechanism of the <span class="hlt">oscillations</span> of low- and intermediate-order p-modes, and the turbulent stochas- tic excitation becomes important only for the high-order p-modes of Sun-like <span class="hlt">oscillations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22596561-patterns-patterns-synchronization-noise-induced-attractor-switching-rings-coupled-nonlinear-oscillators','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22596561-patterns-patterns-synchronization-noise-induced-attractor-switching-rings-coupled-nonlinear-oscillators"><span>Patterns of patterns of synchronization: Noise induced attractor switching in rings of coupled nonlinear <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Emenheiser, Jeffrey; Department of Physics, University of California, Davis, California 95616; Chapman, Airlie</p> <p></p> <p>Following the long-lived qualitative-dynamics tradition of explaining behavior in complex systems via the architecture of their attractors and basins, we investigate the patterns of switching between distinct trajectories in a network of synchronized <span class="hlt">oscillators</span>. Our system, consisting of nonlinear amplitude-phase <span class="hlt">oscillators</span> arranged in a ring topology with reactive nearest-neighbor coupling, is simple and connects directly to experimental realizations. We seek to understand how the multiple <span class="hlt">stable</span> synchronized states connect to each other in state space by applying Gaussian white noise to each of the <span class="hlt">oscillators</span>' phases. To do this, we first analytically identify a set of locally <span class="hlt">stable</span> limit cyclesmore » at any given coupling strength. For each of these attracting states, we analyze the effect of weak noise via the covariance matrix of deviations around those attractors. We then explore the noise-induced attractor switching behavior via numerical investigations. For a ring of three <span class="hlt">oscillators</span>, we find that an attractor-switching event is always accompanied by the crossing of two adjacent <span class="hlt">oscillators</span>' phases. For larger numbers of <span class="hlt">oscillators</span>, we find that the distribution of times required to stochastically leave a given state falls off exponentially, and we build an attractor switching network out of the destination states as a coarse-grained description of the high-dimensional attractor-basin architecture.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009254','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009254"><span>Amplitude-Stabilized <span class="hlt">Oscillator</span> for a Capacitance-Probe Electrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blaes, Brent R.; Schaefer, Rembrandt T.</p> <p>2012-01-01</p> <p>A multichannel electrometer voltmeter that employs a mechanical resonator maintained in sustained amplitude-stabilized <span class="hlt">oscillation</span> has been developed for the space-based measurement of an Internal Electrostatic Discharge Monitor (IESDM) sensor. The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. Creating a <span class="hlt">stable</span> <span class="hlt">oscillator</span> from the mechanical resonator was achieved by employing magnetic induction for sensing the resonator s velocity, and forcing a current through a coil embedded in the resonator to produce a Lorentz actuation force that overcomes the resonator s dissipative losses. Control electronics employing an AGC loop provide conditions for stabilized, constant amplitude harmonic <span class="hlt">oscillation</span>. The prototype resonator was composed of insulating FR4 printed-wireboard (PWB) material containing a flat, embedded, rectangular coil connected through flexure springs to a base PWB, and immersed in a magnetic field having two regions of opposite field direction generated by four neodymium block magnets. In addition to maintaining the mechanical movement needed for the electrometer s capacitor-probe transducer, this <span class="hlt">oscillator</span> provides a reference signal for synchronous detection of the capacitor probe s output signal current so drift of <span class="hlt">oscillation</span> frequency due to environmental effects is inconsequential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARJ50015N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARJ50015N"><span>Janus nanoparticles for <span class="hlt">stable</span> microemulsions with <span class="hlt">ultra</span>-low IFT values</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nava, Ilse; Diaz, Agustin; Yu, Yi-Hsien; Cheng, Zhengdong</p> <p>2015-03-01</p> <p>Janus particles are an influential type of materials used in foams, detergents, surfactants and cosmetics. Due to their demonstrated flexibility and non-toxicity, they have the potential to replace molecular surfactants, and thanks to their amphiphilicity, they can stabilize immiscible biphasic systems. Disk-based Janus particles best perform this stabilization. Graphene has been used to manufacture this class of particles; however, their fabrication in high yield by short and atomically economic syntheses remains a challenge. In this project we report the first synthesis of monolayer disks by a one pot reaction under microwave energy. Using a scalable method, these disks were synthesized, emulsified (in an oil/water system), and chemically reacted to obtain the Janus nanodisks with an efficient method. Our nanosheets production technique is a promising approach for the fabrication of Janus nanodisks via emulsification as it produces IFT (interfacial tension) values in a lower range than that of the molecular surfactants. These <span class="hlt">ultra</span>-low values, in conjunction with the sheets' salt resistance, temperature resistance, and non-toxicity position Janus particles as the next generation of nanosurfactants.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26113805','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26113805"><span>Rhabdomyolysis and exercise-associated hyponatremia in <span class="hlt">ultra</span>-bikers and <span class="hlt">ultra</span>-runners.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chlíbková, Daniela; Knechtle, Beat; Rosemann, Thomas; Tomášková, Ivana; Novotný, Jan; Žákovská, Alena; Uher, Tomáš</p> <p>2015-01-01</p> <p>Exercise-associated hyponatremia (EAH), rhabdomyolysis and renal failure appear to be a unique problem in <span class="hlt">ultra</span>-endurance racers. We investigated the combined occurrence of EAH and rhabdomyolysis in seven different <span class="hlt">ultra</span>-endurance races and disciplines (i.e. multi-stage mountain biking, 24-h mountain biking, 24-h <span class="hlt">ultra</span>-running and 100-km <span class="hlt">ultra</span>-running). Two (15.4%) <span class="hlt">ultra</span>-runners (man and woman) from hyponatremic <span class="hlt">ultra</span>-athletes (n = 13) and four (4%) <span class="hlt">ultra</span>-runners (four men) from the normonatremic group (n = 100) showed rhabdomyolysis following elevated blood creatine kinase (CK) levels > 10,000 U/L without the development of renal failure and the necessity of a medical treatment. Post-race creatine kinase, plasma and urine creatinine significantly increased, while plasma [Na(+)] and creatine clearance decreased in hyponatremic and normonatremic athletes, respectively. The percentage increase of CK was higher in the hyponatremic compared to the normonatremic group (P < 0.05). Post-race CK levels were higher in <span class="hlt">ultra</span>-runners compared to mountain bikers (P < 0.01), in faster normonatremic (P < 0.05) and older and more experienced hyponatremic <span class="hlt">ultra</span>-athletes (P < 0.05). In all finishers, pre-race plasma [K(+)] was related to post-race CK (P < 0.05). Hyponatremic <span class="hlt">ultra</span>-athletes tended to develop exercise-induced rhabdomyolysis more frequently than normonatremic <span class="hlt">ultra</span>-athletes. <span class="hlt">Ultra</span>-runners tended to develop rhabdomyolysis more frequently than mountain bikers. We found no association between post-race plasma [Na(+)] and CK concentration in both hypo- and normonatremic <span class="hlt">ultra</span>-athletes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820043852&hterms=fossils&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dfossils','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820043852&hterms=fossils&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dfossils"><span><span class="hlt">Oscillating</span> dynamo in the presence of a fossil magnetic field - The solar cycle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Levy, E. H.; Boyer, D.</p> <p>1982-01-01</p> <p>Hydromagnetic dynamo generation of <span class="hlt">oscillating</span> magnetic fields in the presence of an external, ambient magnetic field introduces a marked polarity asymmetry between the two halves of the magnetic cycle. The principle of <span class="hlt">oscillating</span> dynamo interaction with external fields is developed, and a tentative application to the sun is described. In the sun a dipole moment associated with the <span class="hlt">stable</span> fluid beneath the convection zone would produce an asymmetrical solar cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870015048','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870015048"><span>Low-cost FM <span class="hlt">oscillator</span> for capacitance type of blade tip clearance measurement system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barranger, John P.</p> <p>1987-01-01</p> <p>The frequency-modulated (FM) <span class="hlt">oscillator</span> described is part of a blade tip clearance measurement system that meets the needs of a wide class of fans, compressors, and turbines. As a result of advancements in the technology of <span class="hlt">ultra</span>-high-frequency operational amplifiers, the FM <span class="hlt">oscillator</span> requires only a single low-cost integrated circuit. Its carrier frequency is 42.8 MHz when it is used with an integrated probe and connecting cable assembly consisting of a 0.81 cm diameter engine-mounted capacitance probe and a 61 cm long hermetically sealed coaxial cable. A complete circuit analysis is given, including amplifier negative resistance characteristics. An error analysis of environmentally induced effects is also derived, and an error-correcting technique is proposed. The <span class="hlt">oscillator</span> can be calibrated in the static mode and has a negative peak frequency deviation of 400 kHz for a rotor blade thickness of 1.2 mm. High-temperature performance tests of the probe and 13 cm of the adjacent cable show good accuracy up to 600 C, the maximum permissible seal temperature. The major source of error is the residual FM <span class="hlt">oscillator</span> noise, which produces a clearance error of + or - 10 microns at a clearance of 0.5 mm. The <span class="hlt">oscillator</span> electronics accommodates the high rotor speeds associated with small engines, the signals from which may have frequency components as high as 1 MHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MAR.E9006M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MAR.E9006M"><span><span class="hlt">Ultras-stable</span> Physical Vapor Deposited Amorphous Teflon Films with Extreme Fictive Temperature Reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenna, Gregory; Yoon, Heedong; Koh, Yung; Simon, Sindee</p> <p></p> <p>In the present work, we have produced highly <span class="hlt">stable</span> amorphous fluoropolymer (Teflon AF® 1600) films to study the calorimetric and relaxation behavior in the deep in the glassy regime. Physical vapor deposition (PVD) was used to produce 110 to 700 nm PVD films with substrate temperature ranging from 0.70 Tg to 0.90 Tg. Fictive temperature (Tf) was measured using Flash DSC with 600 K/s heating and cooling rates. Consistent with prior observations for small molecular weight glasses, large enthalpy overshoots were observed in the <span class="hlt">stable</span> amorphous Teflon films. The Tf reduction for the <span class="hlt">stable</span> Teflon films deposited in the vicinity of 0.85 Tg was approximately 70 K compared to the Tgof the rejuvenated system. The relaxation behavior of <span class="hlt">stable</span> Teflon films was measured using the TTU bubble inflation technique and following Struik's protocol in the temperature range from Tf to Tg. The results show that the relaxation time decreases with increasing aging time implying that devitrification is occurring in this regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.172...40K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.172...40K"><span>Finite amplitude transverse <span class="hlt">oscillations</span> of a magnetic rope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolotkov, Dmitrii Y.; Nisticò, Giuseppe; Rowlands, George; Nakariakov, Valery M.</p> <p>2018-07-01</p> <p>The effects of finite amplitudes on the transverse <span class="hlt">oscillations</span> of a quiescent prominence represented by a magnetic rope are investigated in terms of the model proposed by Kolotkov et al. (2016). We consider a weakly nonlinear case governed by a quadratic nonlinearity, and also analyse the fully nonlinear equations of motion. We treat the prominence as a massive line current located above the photosphere and interacting with the magnetised dipped environment via the Lorentz force. In this concept the magnetic dip is produced by two external current sources located at the photosphere. Finite amplitude horizontal and vertical <span class="hlt">oscillations</span> are found to be strongly coupled between each other. The coupling is more efficient for larger amplitudes and smaller attack angles between the direction of the driver and the horizontal axis. Spatial structure of <span class="hlt">oscillations</span> is represented by Lissajous-like curves with the limit cycle of a hourglass shape, appearing in the resonant case, when the frequency of the vertical mode is twice the horizontal mode frequency. A metastable equilibrium of the prominence is revealed, which is <span class="hlt">stable</span> for small amplitude displacements, and becomes horizontally unstable, when the amplitude exceeds a threshold value. The maximum <span class="hlt">oscillation</span> amplitudes are also analytically derived and analysed. Typical <span class="hlt">oscillation</span> periods are determined by the <span class="hlt">oscillation</span> amplitude, prominence current, its mass and position above the photosphere, and the parameters of the magnetic dip. The main new effects of the finite amplitude are the coupling of the horizontally and vertically polarised transverse <span class="hlt">oscillations</span> (i.e. the lack of a simple, elliptically polarised regime) and the presence of metastable equilibria of prominences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HMT....53.3059R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HMT....53.3059R"><span>Experimental investigation on the thermal performance of a closed <span class="hlt">oscillating</span> heat pipe in thermal management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, Zhonghao; Wang, Qingchao; Zhao, Jiateng; Huang, Congliang</p> <p>2017-10-01</p> <p>To investigate the thermal performance of the closed <span class="hlt">oscillating</span> heat pipe (OHP) as a passive heat transfer device in thermal management system, the gravitation force, surface tension, cooling section position and inclination angle were discussed with applied heating power ranging from 5 to 65 W. The deionized water was chosen as the working fluid and liquid-filling ratio was 50 ± 5%. The operation of the OHP mainly depends on the phase change of the working fluid. The working fluid within the OHP was constantly evaporated and cooled. The results show that the movement of the working fluid was similar to the forced damped mechanical vibration, it has to overcome the capillary resistance force and the <span class="hlt">stable</span> <span class="hlt">oscillation</span> should be that the OHP could successful startup. The <span class="hlt">oscillation</span> frequency slowed and <span class="hlt">oscillation</span> amplitude decreased when the inclination angle of the OHP increased. However, the thermal resistance increased. With the increment of the heating power, the average temperature of the evaporation and condensation section would be close. If the heating power was further increased, dry-out phenomenon within the OHP would appeared. With the decrement of the L, the start-up heating power also decreased and <span class="hlt">stable</span> <span class="hlt">oscillation</span> would be formed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29769556','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29769556"><span>Optimal Design of Miniaturized Reflecting Metasurfaces for <span class="hlt">Ultra</span>-Wideband and Angularly <span class="hlt">Stable</span> Polarization Conversion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Borgese, Michele; Costa, Filippo; Genovesi, Simone; Monorchio, Agostino; Manara, Giuliano</p> <p>2018-05-16</p> <p>An <span class="hlt">ultra</span>-wideband linear polarization converter based on a reflecting metasurface is presented. The polarizer is composed by a periodic arrangement of miniaturized metallic elements printed on a grounded dielectric substrate. In order to achieve broadband polarization converting properties, the metasurface is optimized by employing a genetic algorithm (GA) which imposes the minimization of the amplitude of the co-polar reflection coefficient over a wide frequency band. The enhanced angular stability of the polarization converter is due to the miniaturized unit cell which is obtained by imposing the maximum periodicity of the metasurface in the GA optimization process. The pixelated polarization converter obtained by the GA exhibits a relative bandwidth of 102% working from 8.12 GHz to 25.16 GHz. The analysis of the surface current distribution of the metasurface led to a methodology for refining the optimized GA solution based on the sequential removal of pixels of the unit cell on which surface currents are not excited. The relative bandwidth of the refined polarizer is extended up to 117.8% with a unit cell periodicity of 0.46 mm, corresponding to λ/20 at the maximum operating frequency. The performance of the proposed <span class="hlt">ultra</span>-wideband polarization metasurface has been confirmed through full-wave simulations and measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4714991','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4714991"><span>Individual lipid encapsulated microbubble radial <span class="hlt">oscillations</span>: Effects of fluid viscosity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Helfield, Brandon; Chen, Xucai; Qin, Bin; Villanueva, Flordeliza S.</p> <p>2016-01-01</p> <p>Ultrasound-stimulated microbubble dynamics have been shown to be dependent on intrinsic bubble properties, including size and shell characteristics. The effect of the surrounding environment on microbubble response, however, has been less investigated. In particular, microbubble optimization studies are generally conducted in water/saline, characterized by a 1 cP viscosity, for application in the vasculature (i.e., 4 cP). In this study, <span class="hlt">ultra</span>-high speed microscopy was employed to investigate fluid viscosity effects on phospholipid encapsulated microbubble <span class="hlt">oscillations</span> at 1 MHz, using a single, eight-cycle pulse at peak negative pressures of 100 and 250 kPa. Microbubble <span class="hlt">oscillations</span> were shown to be affected by fluid viscosity in a size- and pressure-dependent manner. In general, the <span class="hlt">oscillation</span> amplitudes exhibited by microbubbles between 3 and 6 μm in 1 cP fluid were larger than in 4 cP fluid, reaching a maximum of 1.7-fold at 100 kPa for microbubbles 3.8 μm in diameter and 1.35-fold at 250 kPa for microbubbles 4.8 μm in diameter. Simulation results were in broad agreement at 250 kPa, however generally underestimated the effect of fluid viscosity at 100 kPa. This is the first experimental demonstration documenting the effects of surrounding fluid viscosity on microbubble <span class="hlt">oscillations</span>, resulting in behavior not entirely predicted by current microbubble models. PMID:26827018</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JApMa..63..199K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JApMa..63..199K"><span>On the persistence of spatiotemporal <span class="hlt">oscillations</span> generated by invasion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kay, A. L.; Sherratt, J. A.</p> <p>1999-10-01</p> <p>Many systems in biology and chemistry are oscillatory, with a <span class="hlt">stable</span>, spatially homogeneous steady state which consists of periodic temporal <span class="hlt">oscillations</span> in the interacting species, and such systems have been extensively studied on infinite or semi-infinite spatial domains. We consider the effect of a finite domain, with zero-flux boundary conditions, on the behaviour of solutions to oscillatory reaction-diffusion equations after invasion. We begin by considering numerical simulations of various oscillatory predatory-prey systems. We conclude that when regular spatiotemporal <span class="hlt">oscillations</span> are left in the wake of invasion, these die out, beginning with a decrease in the spatial frequency of the <span class="hlt">oscillations</span> at one boundary, which then propagates across the domain. The long-time solution in this case is purely temporal <span class="hlt">oscillations</span>, corresponding to the limit cycle of the kinetics. Contrastingly, when irregular spatiotemporal <span class="hlt">oscillations</span> are left in the wake of invasion, they persist, even in very long time simulations. To study this phenomenon in more detail, we consider the {lambda}-{omega} class of reaction-diffusion systems. Numerical simulations show that these systems also exhibit die-out of regular spatiotemporal <span class="hlt">oscillations</span> and persistence of irregular spatiotemporal <span class="hlt">oscillations</span>. Exploiting the mathematical simplicity of the {lambda}-{omega} form, we derive analytically an approximation to the transition fronts in r and {theta}x which occur during the die-out of the regular <span class="hlt">oscillations</span>. We then use this approximation to describe how the die-out occurs, and to derive a measure of its rate, as a function of parameter values. We discuss applications of our results to ecology, calcium signalling and chemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22210503-new-type-synchronization-oscillators-hard-excitation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22210503-new-type-synchronization-oscillators-hard-excitation"><span>New type of synchronization of <span class="hlt">oscillators</span> with hard excitation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kovaleva, M. A., E-mail: margo.kovaleva@gmail.com; Manevich, L. I., E-mail: manevichleonid3@gmail.com; Pilipchuk, V. N.</p> <p>2013-08-15</p> <p>It is shown that <span class="hlt">stable</span> limiting cycles corresponding to nonlinear beats with complete energy exchange between <span class="hlt">oscillators</span> can exist in a system of two weakly coupled active <span class="hlt">oscillators</span> (generators). The oscillatory regime of this type, which implements a new type of synchronization in an active system, is an alternative to the well-studied synchronization in a regime close to a nonlinear normal mode. In this case, the ranges of dissipative parameters corresponding to different types of synchronization do not intersect. The analytic description of attractors revealed in analysis is based on the concept of limiting phase trajectories, which was developed earliermore » by one of the authors for conservative systems. A transition (in the parametric space) from the complete energy exchange between <span class="hlt">oscillators</span> to predominant localization of energy in one of the <span class="hlt">oscillators</span> can be naturally described using this concept. The localized normal mode is an attractor in the range of parameters in which neither the limiting phase trajectory nor any of the collective normal modes is an attractor.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95e2403P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95e2403P"><span>Robustness of synthetic <span class="hlt">oscillators</span> in growing and dividing cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paijmans, Joris; Lubensky, David K.; Rein ten Wolde, Pieter</p> <p>2017-05-01</p> <p>Synthetic biology sets out to implement new functions in cells, and to develop a deeper understanding of biological design principles. Elowitz and Leibler [Nature (London) 403, 335 (2000), 10.1038/35002125] showed that by rational design of the reaction network, and using existing biological components, they could create a network that exhibits periodic gene expression, dubbed the repressilator. More recently, Stricker et al. [Nature (London) 456, 516 (2008), 10.1038/nature07389] presented another synthetic <span class="hlt">oscillator</span>, called the dual-feedback <span class="hlt">oscillator</span>, which is more <span class="hlt">stable</span>. Detailed studies have been carried out to determine how the stability of these <span class="hlt">oscillators</span> is affected by the intrinsic noise of the interactions between the components and the stochastic expression of their genes. However, as all biological <span class="hlt">oscillators</span> reside in growing and dividing cells, an important question is how these <span class="hlt">oscillators</span> are perturbed by the cell cycle. In previous work we showed that the periodic doubling of the gene copy numbers due to DNA replication can couple not only natural, circadian <span class="hlt">oscillators</span> to the cell cycle [Paijmans et al., Proc. Natl. Acad. Sci. (USA) 113, 4063 (2016), 10.1073/pnas.1507291113], but also these synthetic <span class="hlt">oscillators</span>. Here we expand this study. We find that the strength of the locking between <span class="hlt">oscillators</span> depends not only on the positions of the genes on the chromosome, but also on the noise in the timing of gene replication: noise tends to weaken the coupling. Yet, even in the limit of high levels of noise in the replication times of the genes, both synthetic <span class="hlt">oscillators</span> show clear signatures of locking to the cell cycle. This work enhances our understanding of the design of robust biological <span class="hlt">oscillators</span> inside growing and diving cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100028873','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100028873"><span>Ionization-Assisted Getter Pumping for <span class="hlt">Ultra-Stable</span> Trapped Ion Frequency Standards</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tjoelker, Robert L.; Burt, Eric A.</p> <p>2010-01-01</p> <p>A method eliminates (or recovers from) residual methane buildup in getter-pumped atomic frequency standard systems by applying ionizing assistance. <span class="hlt">Ultra</span>-high stability trapped ion frequency standards for applications requiring very high reliability, and/or low power and mass (both for ground-based and space-based platforms) benefit from using sealed vacuum systems. These systems require careful material selection and system processing (cleaning and high-temperature bake-out). Even under the most careful preparation, residual hydrogen outgassing from vacuum chamber walls typically limits the base pressure. Non-evaporable getter pumps (NEGs) provide a convenient pumping option for sealed systems because of low mass and volume, and no power once activated. An ion gauge in conjunction with a NEG can be used to provide a low mass, low-power method for avoiding the deleterious effects of methane buildup in high-performance frequency standard vacuum systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Freq...71..449C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Freq...71..449C"><span>Efficient <span class="hlt">Ultra</span>-High Speed Communication with Simultaneous Phase and Amplitude Regenerative Sampling (SPARS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlowitz, Christian; Girg, Thomas; Ghaleb, Hatem; Du, Xuan-Quang</p> <p>2017-09-01</p> <p>For <span class="hlt">ultra</span>-high speed communication systems at high center frequencies above 100 GHz, we propose a disruptive change in system architecture to address major issues regarding amplifier chains with a large number of amplifier stages. They cause a high noise figure and high power consumption when operating close to the frequency limits of the underlying semiconductor technologies. Instead of scaling a classic homodyne transceiver system, we employ repeated amplification in single-stage amplifiers through positive feedback as well as synthesizer-free self-mixing demodulation at the receiver to simplify the system architecture notably. Since the amplitude and phase information for the emerging <span class="hlt">oscillation</span> is defined by the input signal and the <span class="hlt">oscillator</span> is only turned on for a very short time, it can be left unstabilized and thus come without a PLL. As soon as gain is no longer the most prominent issue, relaxed requirements for all the other major components allow reconsidering their implementation concepts to achieve further improvements compared to classic systems. This paper provides the first comprehensive overview of all major design aspects that need to be addressed upon realizing a SPARS-based transceiver. At system level, we show how to achieve high data rates and a noise performance comparable to classic systems, backed by scaled demonstrator experiments. Regarding the transmitter, design considerations for efficient quadrature modulation are discussed. For the frontend components that replace PA and LNA amplifier chains, implementation techniques for regenerative sampling circuits based on super-regenerative <span class="hlt">oscillators</span> are presented. Finally, an analog-to-digital converter with outstanding performance and complete interfaces both to the analog baseband as well as to the digital side completes the set of building blocks for efficient <span class="hlt">ultra</span>-high speed communication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26831958','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26831958"><span><span class="hlt">Ultra</span>-compact Watt-level flat supercontinuum source pumped by noise-like pulse from an all-fiber <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, He; Zhou, Xuanfeng; Chen, Sheng-Ping; Jiang, Zong-Fu; Hou, Jing</p> <p>2015-12-28</p> <p>We demonstrate Watt-level flat visible supercontinuum (SC) generation in photonic crystal fibers, which is directly pumped by broadband noise-like pulses from an Yb-doped all-fiber <span class="hlt">oscillator</span>. The novel SC generator is featured with elegant all-fiber-integrated architecture, high spectral flatness and high efficiency. Wide optical spectrum spanning from 500 nm to 2300 nm with 1.02 W optical power is obtained under the pump of 1.4 W noise-like pulse. The flatness of the spectrum in the range of 700 nm~1600 nm is less than 5 dB (including the pump residue). The exceptional simplicity, economical efficiency and the comparable performances make the noise-like pulse <span class="hlt">oscillator</span> a competitive candidate to the widely used cascade amplified coherent pulse as the pump source of broadband SC. To the best of our knowledge, this is the first demonstration of SC generation which is directly pumped by an all-fiber noise-like pulse <span class="hlt">oscillator</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18654523','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18654523"><span>Bit storage and bit flip operations in an electromechanical <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mahboob, I; Yamaguchi, H</p> <p>2008-05-01</p> <p>The Parametron was first proposed as a logic-processing system almost 50 years ago. In this approach the two <span class="hlt">stable</span> phases of an excited harmonic <span class="hlt">oscillator</span> provide the basis for logic operations. Computer architectures based on LC <span class="hlt">oscillators</span> were developed for this approach, but high power consumption and difficulties with integration meant that the Parametron was rendered obsolete by the transistor. Here we propose an approach to mechanical logic based on nanoelectromechanical systems that is a variation on the Parametron architecture and, as a first step towards a possible nanomechanical computer, we demonstrate both bit storage and bit flip operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912345I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912345I"><span>Decadal variability of drought conditions over the southern part of Europe based on Principal <span class="hlt">Oscillation</span> Pattern Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ionita-Scholz, Monica; Tallaksen, Lena M.; Scholz, Patrick</p> <p>2017-04-01</p> <p>This study introduces a novel method of estimating the decay time, mean period and forcing statistics of drought conditions over large spatial domains, demonstrated here for southern part of Europe (10°E - 40°E, 35°N - 50°N). It uses a two-dimensional stochastically forced damped linear <span class="hlt">oscillator</span> model with the model parameters estimated from a Principal <span class="hlt">Oscillation</span> Pattern (POP) analysis and associated observed power spectra. POP is a diagnostic technique that aims to derive the space-time characteristics of a data set objectively. This analysis is performed on an extended observational time series of 114 years (1902 - 2015) of the Standardized Precipitation Evapotranspiration Index for an accumulation period of 12 months (SPEI12), based on the Climate Research Unit (CRU TS v. 3.24) data set. The POP analysis reveals four exceptionally <span class="hlt">stable</span> modes of variability, which together explain more than 62% of the total explained variance. The most <span class="hlt">stable</span> POP mode, which explains 16.3% of the total explained variance, is characterized by a period of <span class="hlt">oscillation</span> of 14 years and a decay time of 31 years. The real part of POP1 is characterized by a monopole-like structure with the highest loadings over Portugal, western part of Spain and Turkey. The second <span class="hlt">stable</span> mode, which explains 15.9% of the total explained variance, is characterized by a period of <span class="hlt">oscillation</span> of 20 years and a decay time of 26.4 years. The spatial structure of the real part of POP2 has a dipole-like structure with the highest positive loadings over France, southern Germany and Romania and negative loadings over southern part of Spain. The third POP mode, in terms of stability, explains 14.0% of the total variance and is characterized by a period of <span class="hlt">oscillation</span> of 33 years and a decay time of 43.5 years. The real part of POP3 is characterized by negative loadings over the eastern part of Europe and positive loadings over Turkey. The fourth <span class="hlt">stable</span> POP mode, explaining 15.5% of the total variance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112t1601A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112t1601A"><span>Low cost and thin metasurface for <span class="hlt">ultra</span> wide band and wide angle polarization insensitive radar cross section reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ameri, Edris; Esmaeli, Seyed Hassan; Sedighy, Seyed Hassan</p> <p>2018-05-01</p> <p>A planar low cost and thin metasurface is proposed to achieve <span class="hlt">ultra</span>-wideband radar cross section (RCS) reduction with <span class="hlt">stable</span> performance with respect to polarization and incident angles. This metasurface is composed of two different artificial magnetic conductor unit cells arranged in a chessboard like configuration. These unit cells have a Jerusalem cross pattern with different thicknesses, which results in wideband out-phase reflection and RCS reduction, consequently. The designed metasurface reduces RCS more than 10-dB from 13.6 GHz to 45.5 GHz (108% bandwidth) and more than 20-dB RCS from 15.2 GHz to 43.6 GHz (96.6%). Moreover, the 10-dB RCS reduction bandwidth is very <span class="hlt">stable</span> (more than 107%) for both TE and TM polarizations. The good agreement between simulations and measurement results proves the design, properly. The <span class="hlt">ultra</span>-wide bandwidth, low cost, low profile, and <span class="hlt">stable</span> performance of this metasurface prove its high capability compared with the state-of-the-art references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..93c2209G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..93c2209G"><span>Parametric spatiotemporal <span class="hlt">oscillation</span> in reaction-diffusion systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghosh, Shyamolina; Ray, Deb Shankar</p> <p>2016-03-01</p> <p>We consider a reaction-diffusion system in a homogeneous <span class="hlt">stable</span> steady state. On perturbation by a time-dependent sinusoidal forcing of a suitable scaling parameter the system exhibits parametric spatiotemporal instability beyond a critical threshold frequency. We have formulated a general scheme to calculate the threshold condition for <span class="hlt">oscillation</span> and the range of unstable spatial modes lying within a V-shaped region reminiscent of Arnold's tongue. Full numerical simulations show that depending on the specificity of nonlinearity of the models, the instability may result in time-periodic stationary patterns in the form of standing clusters or spatially localized breathing patterns with characteristic wavelengths. Our theoretical analysis of the parametric <span class="hlt">oscillation</span> in reaction-diffusion system is corroborated by full numerical simulation of two well-known chemical dynamical models: chlorite-iodine-malonic acid and Briggs-Rauscher reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27078346','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27078346"><span>Parametric spatiotemporal <span class="hlt">oscillation</span> in reaction-diffusion systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghosh, Shyamolina; Ray, Deb Shankar</p> <p>2016-03-01</p> <p>We consider a reaction-diffusion system in a homogeneous <span class="hlt">stable</span> steady state. On perturbation by a time-dependent sinusoidal forcing of a suitable scaling parameter the system exhibits parametric spatiotemporal instability beyond a critical threshold frequency. We have formulated a general scheme to calculate the threshold condition for <span class="hlt">oscillation</span> and the range of unstable spatial modes lying within a V-shaped region reminiscent of Arnold's tongue. Full numerical simulations show that depending on the specificity of nonlinearity of the models, the instability may result in time-periodic stationary patterns in the form of standing clusters or spatially localized breathing patterns with characteristic wavelengths. Our theoretical analysis of the parametric <span class="hlt">oscillation</span> in reaction-diffusion system is corroborated by full numerical simulation of two well-known chemical dynamical models: chlorite-iodine-malonic acid and Briggs-Rauscher reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApSS..427..830L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApSS..427..830L"><span>Template-free synthesis of porous ZnO/Ag microspheres as recyclable and <span class="hlt">ultra</span>-sensitive SERS substrates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yanjun; Xu, Chunxiang; Lu, Junfeng; Zhu, Zhu; Zhu, Qiuxiang; Manohari, A. Gowri; Shi, Zengliang</p> <p>2018-01-01</p> <p>The porous structured zinc oxide (ZnO) microspheres decorated with silver nanoparticles (Ag NPs) have been fabricated as surface-enhanced Raman scattering (SERS) substrate for <span class="hlt">ultra</span>-sensitive, highly reproducible and <span class="hlt">stable</span> biological/chemical sensing of various organic molecules. The ZnO microspheres were hydrothermally synthesized without any template, and the Ag NPs decorated on microspheres via photochemical reaction in situ, which provided <span class="hlt">stable</span> Ag/ZnO contact to achieve a sensitive SERS response. It demonstrates a higher enhancement factor (EF) of 2.44 × 1011 and a lower detection limit of 10-11 M-10-12 M. This porous SERS substrate could also be self-cleaned through a photocatalytic process and then further recycled for the detection of same or different molecules, such as phenol red (PhR), dopamine (DA) and glucose (GLU) with <span class="hlt">ultra</span>-low concentration and it possessed a sensitive response. The excellent performances are attributed to morphology of porous microspheres, hybrid structure of semiconductor/metal and corresponding localized field enhancement of surface plasmons. Therefore, it is expected to design the recyclable <span class="hlt">ultra</span>-sensitive SERS sensors for the detection of biological molecules and organic pollutant monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22489655-sustained-magnetization-oscillations-polyaniline-fe-sub-sub-nanocomposites','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22489655-sustained-magnetization-oscillations-polyaniline-fe-sub-sub-nanocomposites"><span>Sustained magnetization <span class="hlt">oscillations</span> in polyaniline-Fe{sub 3}O{sub 4} nanocomposites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Araújo, A. C. V. de; Rodrigues, A. R., E-mail: ricalde@df.ufpe.br; Machado, F. L. A.</p> <p>2015-09-28</p> <p>We report experiments with polyaniline-Fe{sub 3}O{sub 4} (PANI-Fe{sub 3}O{sub 4}) nanocomposites synthesized under several different conditions. With a reaction carried out at room temperature and assisted by intense <span class="hlt">ultra</span>-violet (UV) irradiation, we observe sustained <span class="hlt">oscillations</span> in the magnetization with a period of about 25 min. The <span class="hlt">oscillations</span> are interpreted as the result of an oscillatory chemical reaction in which part of the Fe{sup +2} ions of magnetite, Fe{sub 3}O{sub 4}, are oxidized by the UV irradiation to form Fe{sup +3} so that a fraction of the magnetite content transforms into maghemite, γ-Fe{sub 2}O{sub 3}. Then, Fe{sup +3} ions at themore » nanoparticle surfaces are reduced and transformed back into Fe{sup +2}, when acting as an oxidizing agent for polyaniline in the polymerization process. Since maghemite has smaller magnetization than magnetite, the <span class="hlt">oscillating</span> chemical reaction results in the oscillatory magnetization. The observations are interpreted with the Lotka-Volterra nonlinear coupled equations with parameters that can be adjusted to fit very well the experimental data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012A%26A...548A.112T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012A%26A...548A.112T"><span>Transverse kink <span class="hlt">oscillations</span> in the presence of twist</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Terradas, J.; Goossens, M.</p> <p>2012-12-01</p> <p>Context. Magnetic twist is thought to play an important role in coronal loops. The effects of magnetic twist on <span class="hlt">stable</span> magnetohydrodynamic (MHD) waves is poorly understood because they are seldom studied for relevant cases. Aims: The goal of this work is to study the fingerprints of magnetic twist on <span class="hlt">stable</span> transverse kink <span class="hlt">oscillations</span>. Methods: We numerically calculated the eigenmodes of propagating and standing MHD waves for a model of a loop with magnetic twist. The azimuthal component of the magnetic field was assumed to be small in comparison to the longitudinal component. We did not consider resonantly damped modes or kink instabilities in our analysis. Results: For a nonconstant twist the frequencies of the MHD wave modes are split, which has important consequences for standing waves. This is different from the degenerated situation for equilibrium models with constant twist, which are characterised by an azimuthal component of the magnetic field that linearly increases with the radial coordinate. Conclusions: In the presence of twist standing kink solutions are characterised by a change in polarisation of the transverse displacement along the tube. For weak twist, and in the thin tube approximation, the frequency of standing modes is unaltered and the tube <span class="hlt">oscillates</span> at the kink speed of the corresponding straight tube. The change in polarisation is linearly proportional to the degree of twist. This has implications with regard to observations of kink modes, since the detection of this variation in polarisation can be used as an indirect method to estimate the twist in <span class="hlt">oscillating</span> loops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23863001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23863001"><span>Reviving <span class="hlt">oscillations</span> in coupled nonlinear <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zou, Wei; Senthilkumar, D V; Zhan, Meng; Kurths, Jürgen</p> <p>2013-07-05</p> <p>By introducing a processing delay in the coupling, we find that it can effectively annihilate the quenching of <span class="hlt">oscillation</span>, amplitude death (AD), in a network of coupled <span class="hlt">oscillators</span> by switching the stability of AD. It revives the <span class="hlt">oscillation</span> in the AD regime to retain sustained rhythmic functioning of the networks, which is in sharp contrast to the propagation delay with the tendency to induce AD. This processing delay-induced phenomenon occurs both with and without the propagation delay. Further this effect is rather general from two coupled to networks of <span class="hlt">oscillators</span> in all known scenarios that can exhibit AD, and it has a wide range of applications where sustained <span class="hlt">oscillations</span> should be retained for proper functioning of the systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3902486','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3902486"><span>Sensitivity to external signals and synchronization properties of a non-isochronous auto-<span class="hlt">oscillator</span> with delayed feedback</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tiberkevich, Vasil S.; Khymyn, Roman S.; Tang, Hong X.; Slavin, Andrei N.</p> <p>2014-01-01</p> <p>For auto-<span class="hlt">oscillators</span> of different nature (e.g. active cells in a human heart under the action of a pacemaker, neurons in brain, spin-torque nano-<span class="hlt">oscillators</span>, micro and nano-mechanical <span class="hlt">oscillators</span>, or generating Josephson junctions) a critically important property is their ability to synchronize with each other. The synchronization properties of an auto <span class="hlt">oscillator</span> are directly related to its sensitivity to external signals. Here we demonstrate that a non-isochronous (having generation frequency dependent on the amplitude) auto-<span class="hlt">oscillator</span> with delayed feedback can have an extremely high sensitivity to external signals and unusually large width of the phase-locking band near the boundary of the <span class="hlt">stable</span> auto-<span class="hlt">oscillation</span> regime. This property could be used for the development of synchronized arrays of non-isochronous auto-<span class="hlt">oscillators</span> in physics and engineering, and, for instance, might bring a better fundamental understanding of ways to control a heart arrythmia in medicine. PMID:24464086</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23062377','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23062377"><span>Dynamic electrical characteristics of low-power ring <span class="hlt">oscillators</span> constructed with inorganic nanoparticles on flexible plastics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yun, Junggwon; Cho, Kyoungah; Kim, Sangsig</p> <p>2012-11-01</p> <p>In this study, we demonstrate for the first time the low-power and <span class="hlt">stable</span> performance of a ring <span class="hlt">oscillator</span> constructed on a flexible plastic with solution-processable inorganic nanoparticles (NPs). Our flexible ring <span class="hlt">oscillator</span> is composed of three inverters based on n- and p-type inorganic NP thin-film transistors. Each of the component inverters exhibits a gain of ∼80 at a voltage of 5 V. For the ring <span class="hlt">oscillator</span>, the sine waves are generated with a frequency of up to 12 kHz. The waveforms are undistorted under strained conditions and maintained even after 5000 bending cycles. The frequency and waveform of the output waves obtained from our flexible ring <span class="hlt">oscillator</span> are analyzed and discussed in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015597','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015597"><span>Lattice Thermal Conductivity of <span class="hlt">Ultra</span> High Temperature Ceramics ZrB2 and HfB2 from Atomistic Simulations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lawson, John W.; Murray, Daw S.; Bauschlicher, Charles W., Jr.</p> <p>2011-01-01</p> <p>Atomistic Green-Kubo simulations are performed to evaluate the lattice thermal conductivity for single crystals of the <span class="hlt">ultra</span> high temperature ceramics ZrB2 and HfB2 for a range of temperatures. Recently developed interatomic potentials are used for these simulations. Heat current correlation functions show rapid <span class="hlt">oscillations</span> which can be identified with mixed metal-Boron optical phonon modes. Agreement with available experimental data is good.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJB...89...12A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJB...89...12A"><span>Duffing revisited: phase-shift control and internal resonance in self-sustained <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arroyo, Sebastián I.; Zanette, Damián H.</p> <p>2016-01-01</p> <p>We address two aspects of the dynamics of the forced Duffing <span class="hlt">oscillator</span> which are relevant to the technology of micromechanical devices and, at the same time, have intrinsic significance to the field of nonlinear <span class="hlt">oscillating</span> systems. First, we study the stability of periodic motion when the phase shift between the external force and the <span class="hlt">oscillation</span> is controlled - contrary to the standard case, where the control parameter is the frequency of the force. Phase-shift control is the operational configuration under which self-sustained <span class="hlt">oscillators</span> - and, in particular, micromechanical <span class="hlt">oscillators</span> - provide a frequency reference useful for time keeping. We show that, contrary to the standard forced Duffing <span class="hlt">oscillator</span>, under phase-shift control <span class="hlt">oscillations</span> are <span class="hlt">stable</span> over the whole resonance curve, and provide analytical approximate expressions for the time dependence of the <span class="hlt">oscillation</span> amplitude and frequency during transients. Second, we analyze a model for the internal resonance between the main Duffing <span class="hlt">oscillation</span> mode and a higher-harmonic mode of a vibrating solid bar clamped at its two ends. We focus on the stabilization of the <span class="hlt">oscillation</span> frequency when the resonance takes place, and present preliminary experimental results that illustrate the phenomenon. This synchronization process has been proposed to counteract the undesirable frequency-amplitude interdependence in nonlinear time-keeping micromechanical devices. Supplementary material in the form of one pdf file and one gif file available from the Journal web page at http://dx.doi.org/10.1140/epjb/e2015-60517-3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720014220','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720014220"><span>Planetary resonances, bi-<span class="hlt">stable</span> <span class="hlt">oscillation</span> modes, and solar activity cycles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sleeper, H. P., Jr.</p> <p>1972-01-01</p> <p>The natural resonance structure of the planets in the solar system yields resonance periods of 11.08 and 180 years. The 11.08 year period is due to resonance of the sidereal periods of the three inner planets. The 180-year period is due to synodic resonances of the four major planets. These periods are also observed in the sunspot time series. The 11-year sunspot cycles from 1 to 19 are separated into categories of positive and negative cycles, Mode 1 and Mode 2 cycles, and typical and anomalous cycles. Each category has a characteristic shape, magnitude, or duration, so that statistical prediction techniques are improved when a cycle can be classified in a given category. These categories provide evidence for bistable modes of solar <span class="hlt">oscillation</span>. The next minimum is expected in 1977 and the next maximum in 1981 or later. These epoch values are 2.5 years later than those based on typical cycle characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..MAR.M1256W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..MAR.M1256W"><span><span class="hlt">Oscillations</span> contribute to memory consolidation by changing criticality and stability in the brain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Jiaxing; Skilling, Quinton; Ognjanovski, Nicolette; Aton, Sara; Zochowski, Michal</p> <p></p> <p><span class="hlt">Oscillations</span> are a universal feature of every level of brain dynamics and have been shown to contribute to many brain functions. To investigate the fundamental mechanism underpinning oscillatory activity, the properties of heterogeneous networks are compared in situations with and without <span class="hlt">oscillations</span>. Our results show that both network criticality and stability are changed in the presence of <span class="hlt">oscillations</span>. Criticality describes the network state of neuronal avalanche, a cascade of bursts of action potential firing in neural network. Stability measures how <span class="hlt">stable</span> the spike timing relationship between neuron pairs is over time. Using a detailed spiking model, we found that the branching parameter σ changes relative to <span class="hlt">oscillation</span> and structural network properties, corresponding to transmission among different critical states. Also, analysis of functional network structures shows that the <span class="hlt">oscillation</span> helps to stabilize neuronal representation of memory. Further, quantitatively similar results are observed in biological data recorded in vivo. In summary, we have observed that, by regulating the neuronal firing pattern, <span class="hlt">oscillations</span> affect both criticality and stability properties of the network, and thus contribute to memory formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97g5151Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97g5151Z"><span>Dynamical Friedel <span class="hlt">oscillations</span> of a Fermi sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, J. M.; Liu, Y.</p> <p>2018-02-01</p> <p>We study the scenario of quenching an interaction-free Fermi sea on a one-dimensional lattice ring by suddenly changing the potential of a site. From the point-of-view of the conventional Friedel <span class="hlt">oscillation</span>, which is a static or equilibrium problem, it is of interest what temporal and spatial <span class="hlt">oscillations</span> the local sudden quench will induce. Numerically, the primary observation is that for a generic site, the local particle density switches between two plateaus periodically in time. Making use of the proximity of the realistic model to an exactly solvable model and employing the Abel regularization to assign a definite value to a divergent series, we obtain an analytical formula for the heights of the plateaus, which turns out to be very accurate for sites not too close to the quench site. The unexpect relevance and the incredible accuracy of the Abel regularization are yet to be understood. Eventually, when the contribution of the defect mode is also taken into account, the plateaus for those sites close to or on the quench site can also be accurately predicted. We have also studied the infinite lattice case. In this case, ensuing the quench, the out-going wave fronts leave behind a <span class="hlt">stable</span> density <span class="hlt">oscillation</span> pattern. Because of some interesting single-particle property, this dynamically generated Friedel <span class="hlt">oscillation</span> differs from its conventional static counterpart only by the defect mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/481955','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/481955"><span>Proxy Records of the Indonesian Low and the El Ni{tilde n}o-Southern <span class="hlt">Oscillation</span> (ENSO) from <span class="hlt">Stable</span> Isotope Measurements of Indonesian Reef Corals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Moore, M.D.</p> <p>1995-12-31</p> <p>The Earth`s largest atmospheric convective center is the Indonesian Low. It generates the Australasian monsoon, drives the zonal tropospheric Walker Circulation, and is implicated in the genesis of the El Nino-Southern <span class="hlt">Oscillation</span> (ENSO). The long-term variability of the Indonesian Low is poorly characterized, yet such information is crucial for evaluating whether changes in the strength and frequency of ENSO events are a possible manifestation of global warming. <span class="hlt">Stable</span> oxygen isotope ratios ({delta}{sup 18}O) in shallow-water reef coral skeletons track topical convective activity over hundreds of years because the input of isotopically-depleted rainwater dilutes seawater {delta}{sup 18}O. Corals also impose amore » temperature-dependent fractionation on {delta}{sup 18}O, but where annual rainfall is high and sea surface temperature (SST) variability is low the freshwater flux effect dominates.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1890d0026W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1890d0026W"><span>Research and preparation of <span class="hlt">ultra</span> purity silicon tetrachloride</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wan, Ye; Zhao, Xiong; Yan, Dazhou; Yang, Dian; Li, Yunhao; Guo, Shuhu</p> <p>2017-10-01</p> <p>This article demonstrated a technology for producing <span class="hlt">ultra</span>-purity silicon tetrachloride, which using the high purity SiCl4 as raw material through the method of combination ray reaction with purification. This technology could remove metal impurities and compounds impurities contained hydrogen effectively. The purity of product prepared by this technology can reach at 99.9999%, content of metal impurities can be low at 0.3PPb, meeting the requirement of industry easily. This technology has the advantages of simple process, continuous operation, and <span class="hlt">stable</span> performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17930809','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17930809"><span>Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chan, H B; Stambaugh, C</p> <p>2007-08-10</p> <p>We explore fluctuation-induced switching in parametrically driven micromechanical torsional <span class="hlt">oscillators</span>. The <span class="hlt">oscillators</span> possess one, two, or three <span class="hlt">stable</span> attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970000444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970000444"><span>Forced <span class="hlt">Oscillations</span> of Supported Drops</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilkes, Edward D.; Basaran, Osman A.</p> <p>1996-01-01</p> <p><span class="hlt">Oscillations</span> of supported liquid drops are the subject of wide scientific interest, with applications in areas as diverse as liquid-liquid extraction, synthesis of ceramic powders, growing of pure crystals in low gravity, and measurement of dynamic surface tension. In this research, axisymmetric forced <span class="hlt">oscillations</span> of arbitrary amplitude of viscous liquid drops of fixed volume which are pendant from or sessile on a rod with a fixed or moving contact line and surrounded by an inviscid ambient gas are induced by moving the rod in the vertical direction sinusiodally in time. In this paper, a preliminary report is made on the computational analysis of the <span class="hlt">oscillations</span> of supported drops that have 'clean' interfaces and whose contact lines remain fixed throughout their motions. The relative importance of forcing to damping can be increased by either increasing the amplitude of rod motion A or Reynolds number Re. It is shown that as the ratio of forcing to damping rises, for drops starting from an initial rest state a sharp increase in deformation can occur when they are forced to <span class="hlt">oscillate</span> in the vicinity of their resonance frequencies, indicating the incipience of hysteresis. However, it is also shown that the existence of a second <span class="hlt">stable</span> limit cycle and the occurrence of hysteresis can be observed if the drop is subjected to a so-called frequency sweep, where the forcing frequency is first increased and then decreased over a suitable range. Because the change in drop deformation response is abrupt in the vicinity of the forcing frequencies where hysteresis occurs, it should be possible to exploit the phenomenon to accurately measure the viscosity and surface tension of the drop liquid.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJB...91..111P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJB...91..111P"><span>Cessation of <span class="hlt">oscillations</span> in a chemo-mechanical <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phogat, Richa; Tiwari, Ishant; Kumar, Pawan; Rivera, Marco; Parmananda, Punit</p> <p>2018-06-01</p> <p>In this paper, different methods for cessation of <span class="hlt">oscillations</span> in a chemo-mechanical <span class="hlt">oscillator</span> [mercury beating heart (MBH)] are presented. The first set of experiments were carried out on a single MBH <span class="hlt">oscillator</span>. To achieve cessation of <span class="hlt">oscillations</span>, two protocols, namely, inverted feedback and delayed feedback were employed. In the second set of experiments, two quasi-identical MBH <span class="hlt">oscillators</span> are considered. They are first synchronized via a bidirectional attractive coupling. These two synchronized <span class="hlt">oscillators</span> are thereafter coupled with a unidirectional repulsive coupling and the system dynamics were observed. Subsequently, in the next protocol, the effect of a unidirectional delay coupling on the two synchronized <span class="hlt">oscillators</span> was explored. The cessation of <span class="hlt">oscillations</span> in all the above experimental setups was observed as the feedback/coupling was switched on at a suitable strength. Oscillatory dynamics of the system were restored when the feedback/coupling was switched off.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982vomo.proc...82L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982vomo.proc...82L"><span>Analogies between <span class="hlt">oscillation</span> and rotation of bodies induced or influenced by vortex shedding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lugt, H. J.</p> <p></p> <p>Vortex-induced or vortex-influenced rotation and <span class="hlt">oscillation</span> of bodies in a parallel flow are discussed. A steady flow occurs if the body axis is parallel to the flow or if the axis of rotation is perpendicular to the flow. Flows around an <span class="hlt">oscillating</span> body are quasi-steady only if the Strougal number is much smaller than unity. The connection between rotation and <span class="hlt">oscillation</span> is demonstrated in terms of the autorotation of a Lanchester propeller, and conditions for <span class="hlt">stable</span> autorotation are defined. The Riabouchinsky curve is shown to be typical of forces and torques on bodies with vortical wakes, including situations with fixed body axes perpendicular to the flow. A differential equation is formulated for rotational and <span class="hlt">oscillating</span> bodies that shed vortices by extending the pendulum equation to include vortical effects expressed as a fifth-order polynomial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20040430','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20040430"><span>1.05-GHz CMOS <span class="hlt">oscillator</span> based on lateral- field-excited piezoelectric AlN contour- mode MEMS resonators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zuo, Chengjie; Van der Spiegel, Jan; Piazza, Gianluca</p> <p>2010-01-01</p> <p>This paper reports on the first demonstration of a 1.05-GHz microelectromechanical (MEMS) <span class="hlt">oscillator</span> based on lateral-field-excited (LFE) piezoelectric AlN contourmode resonators. The <span class="hlt">oscillator</span> shows a phase noise level of -81 dBc/Hz at 1-kHz offset frequency and a phase noise floor of -146 dBc/Hz, which satisfies the global system for mobile communications (GSM) requirements for <span class="hlt">ultra</span>-high frequency (UHF) local <span class="hlt">oscillators</span> (LO). The circuit was fabricated in the AMI semiconductor (AMIS) 0.5-microm complementary metaloxide- semiconductor (CMOS) process, with the <span class="hlt">oscillator</span> core consuming only 3.5 mW DC power. The device overall performance has the best figure-of-merit (FoM) when compared with other gigahertz <span class="hlt">oscillators</span> that are based on film bulk acoustic resonator (FBAR), surface acoustic wave (SAW), and CMOS on-chip inductor and capacitor (CMOS LC) technologies. A simple 2-mask process was used to fabricate the LFE AlN resonators operating between 843 MHz and 1.64 GHz with simultaneously high Q (up to 2,200) and kt 2 (up to 1.2%). This process further relaxes manufacturing tolerances and improves yield. All these advantages make these devices suitable for post-CMOS integrated on-chip direct gigahertz frequency synthesis in reconfigurable multiband wireless communications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22726241','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22726241"><span><span class="hlt">Ultra</span>-long-acting insulin degludec has a flat and <span class="hlt">stable</span> glucose-lowering effect in type 2 diabetes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heise, T; Nosek, L; Bøttcher, S G; Hastrup, H; Haahr, H</p> <p>2012-10-01</p> <p>Insulin degludec (IDeg) is a new-generation, <span class="hlt">ultra</span>-long-acting basal insulin that forms soluble multihexamers upon subcutaneous injection, resulting in a depot from which IDeg is absorbed slowly and continuously into circulation. This double-blind, two-period, incomplete block cross-over trial investigated the pharmacodynamic and pharmacokinetic properties of IDeg at steady state (SS) in people with type 2 diabetes. Forty-nine subjects treated with insulin without concomitant oral anti-diabetic drugs were given IDeg (0.4, 0.6 and/or 0.8 U/kg) once daily for two 6-day periods, separated by an interval of 13-21 days. Following dosing on Day 6, subjects underwent a 26-h euglycaemic glucose clamp (Biostator®; clamp blood glucose level: 90 mg/dl; 5.0 mmol/l). Pharmacokinetic samples were taken until 120 h after last dosing. For all dose levels, the mean glucose infusion rate (GIR) profiles were flat and <span class="hlt">stable</span>. The glucose-lowering effect of IDeg was evenly distributed over the dosing interval τ, with area under the curve (AUC) for each of the four 6-h intervals being approximately 25% of the total AUC (AUC(GIR) (,τ,) (SS) ). Total glucose-lowering effect increased linearly with increasing dose. The blood glucose levels of all subjects stayed very close to the clamp target until end of clamp. The terminal half-life of IDeg was approximately 25 h at steady state. IDeg was well tolerated and no safety concerns were identified. No injection site reactions were reported. IDeg has a flat and consistent glucose-lowering effect in people with type 2 diabetes. © 2012 Blackwell Publishing Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/461127','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/461127"><span>Future prospects of baryon istability search in p-decay and n n(bar) <span class="hlt">oscillation</span> experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ball, S.J.; Kamyshkov, Y.A.</p> <p>1996-11-01</p> <p>These proceedings contain thirty-one papers which review both the theoretical and the experimental status and near future of baryon instability research. Baryon instability is investigated from the vantage point of supersymmetric and unified theories. The interplay between baryogenesis and antimatter is examined. Double beta decay experiments are discussed. The huge Icarus experiment is described with its proton decay capabilities. Neutron-antineutron <span class="hlt">oscillations</span> investigations are presented, especially efforts with <span class="hlt">ultra</span>-cold neutrons. Individual papers are indexed separately on the Energy Data Base.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2610326','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2610326"><span>Dynamic mechanical <span class="hlt">oscillations</span> during metamorphosis of the monarch butterfly</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pelling, Andrew E; Wilkinson, Paul R; Stringer, Richard; Gimzewski, James K</p> <p>2008-01-01</p> <p>The mechanical <span class="hlt">oscillation</span> of the heart is fundamental during insect metamorphosis, but it is unclear how morphological changes affect its mechanical dynamics. Here, the micromechanical heartbeat with the monarch chrysalis (Danaus plexippus) during metamorphosis is compared with the structural changes observed through in vivo magnetic resonance imaging (MRI). We employ a novel <span class="hlt">ultra</span>-sensitive detection approach, optical beam deflection, in order to measure the microscale motions of the pupae during the course of metamorphosis. We observed very distinct mechanical contractions occurring at regular intervals, which we ascribe to the mechanical function of the heart organ. Motion was observed to occur in approximately 15 min bursts of activity with frequencies in the 0.4–1.0 Hz range separated by periods of quiescence during the first 83 per cent of development. In the final stages, the beating was found to be uninterrupted until the adult monarch butterfly emerged. Distinct stages of development were characterized by changes in frequency, amplitude, mechanical quality factor and de/repolarization times of the mechanical pulsing. The MRI revealed that the heart organ remains functionally intact throughout metamorphosis but undergoes morphological changes that are reflected in the mechanical <span class="hlt">oscillation</span>. PMID:18682363</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941800','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2941800"><span>Propagating wave and irregular dynamics: Spatiotemporal patterns of cholinergic theta <span class="hlt">oscillations</span> in neocortex, in vitro</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bao, Weili; Wu, Jian-young</p> <p>2010-01-01</p> <p>Neocortical “theta” <span class="hlt">oscillation</span> (5- 12 Hz) has been observed in animals and human subjects but little is known about how the <span class="hlt">oscillation</span> is organized in the cortical intrinsic networks. Here we use voltage-sensitive dye and optical imaging to study a carbachol/bicuculline induced theta (~8 Hz) <span class="hlt">oscillation</span> in rat neocortical slices. The imaging has large signal-to-noise ratio, allowing us to map the phase distribution over the neocortical tissue during the <span class="hlt">oscillation</span>. The <span class="hlt">oscillation</span> was organized as spontaneous epochs and each epoch was composed of a “first spike”, a “regular” period (with relatively <span class="hlt">stable</span> frequency and amplitude) and an “irregular” period (with variable frequency and amplitude) of <span class="hlt">oscillations</span>. During each cycle of the regular <span class="hlt">oscillation</span> one wave of activation propagated horizontally (parallel to the cortical lamina) across the cortical section at a velocity of ~50 mm/sec. Vertically the activity was synchronized through all cortical layers. This pattern of one propagating wave associated with one <span class="hlt">oscillation</span> cycle was seen during all the regular cycles. The <span class="hlt">oscillation</span> frequency varied noticeably at two neighboring horizontal locations (330 μm apart), suggesting that the <span class="hlt">oscillation</span> is locally organized and each local <span class="hlt">oscillator</span> is about equal or less than 300 μm wide horizontally. During irregular <span class="hlt">oscillations</span> the spatiotemporal patterns were complex and sometimes the vertical synchronization decomposed, suggesting a de-coupling among local <span class="hlt">oscillators</span>. Our data suggested that neocortical theta <span class="hlt">oscillation</span> is sustained by multiple local <span class="hlt">oscillators</span>. The coupling regime among the <span class="hlt">oscillators</span> may determine the spatiotemporal pattern and switching between propagating waves and irregular patterns. PMID:12612003</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18019233','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18019233"><span>Design considerations of Miller <span class="hlt">oscillators</span> for high-sensitivity QCM sensors in damping media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rodriguez-Pardo, Loreto; Fariña, Jose; Gabrielli, Claude; Perrot, Hubert; Brendel, Remi</p> <p>2007-10-01</p> <p>In this paper, a new contribution to the design of quartz crystal <span class="hlt">oscillators</span> for high-sensitivity microbalance sensors used in liquid media is presented. The <span class="hlt">oscillation</span> condition for a Miller configuration was studied to work in a wide dynamic range of the resonator losses. The equations relating the values of the active and passive components with the maximum supported damping and mass were obtained. Also, the conditions to obtain a <span class="hlt">stable</span> frequency according to the resonator damping (R(Q)), the static capacity (Cp) and the filter frequency (f(F)) were found. Under these conditions, the circuit <span class="hlt">oscillation</span> frequency will be proportional to the resonant series frequency and does not depend on the previous parameters (R(Q), f(F), and Cp). If these conditions cannot be satisfied, the expression of the <span class="hlt">oscillation</span> frequency is given and the discrimination of these effects is obtained through resonator frequency measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhR...525..167J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhR...525..167J"><span>Self-<span class="hlt">oscillation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jenkins, Alejandro</p> <p>2013-04-01</p> <p>Physicists are very familiar with forced and parametric resonance, but usually not with self-<span class="hlt">oscillation</span>, a property of certain dynamical systems that gives rise to a great variety of vibrations, both useful and destructive. In a self-<span class="hlt">oscillator</span>, the driving force is controlled by the <span class="hlt">oscillation</span> itself so that it acts in phase with the velocity, causing a negative damping that feeds energy into the vibration: no external rate needs to be adjusted to the resonant frequency. The famous collapse of the Tacoma Narrows bridge in 1940, often attributed by introductory physics texts to forced resonance, was actually a self-<span class="hlt">oscillation</span>, as was the swaying of the London Millennium Footbridge in 2000. Clocks are self-<span class="hlt">oscillators</span>, as are bowed and wind musical instruments. The heart is a “relaxation oscillator”, i.e., a non-sinusoidal self-<span class="hlt">oscillator</span> whose period is determined by sudden, nonlinear switching at thresholds. We review the general criterion that determines whether a linear system can self-<span class="hlt">oscillate</span>. We then describe the limiting cycles of the simplest nonlinear self-<span class="hlt">oscillators</span>, as well as the ability of two or more coupled self-<span class="hlt">oscillators</span> to become spontaneously synchronized (“entrained”). We characterize the operation of motors as self-<span class="hlt">oscillation</span> and prove a theorem about their limit efficiency, of which Carnot’s theorem for heat engines appears as a special case. We briefly discuss how self-<span class="hlt">oscillation</span> applies to servomechanisms, Cepheid variable stars, lasers, and the macroeconomic business cycle, among other applications. Our emphasis throughout is on the energetics of self-<span class="hlt">oscillation</span>, often neglected by the literature on nonlinear dynamical systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCo...710788Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCo...710788Z"><span>Phase-selective entrainment of nonlinear <span class="hlt">oscillator</span> ensembles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z.; Li-Shin, Jr.</p> <p>2016-03-01</p> <p>The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological <span class="hlt">oscillator</span> ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create <span class="hlt">stable</span> phase patterns in ensembles of heterogeneous nonlinear <span class="hlt">oscillators</span> without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/36652','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/36652"><span>Low temperature processing of <span class="hlt">ultra</span>-pure cellulose fibers into nylon 6 and other thermoplastics</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Rod Jacobson; Dan Caulfield; Karl Sears; John Underwood</p> <p>2002-01-01</p> <p>The objective of this research was to develop a <span class="hlt">stable</span> process for compound <span class="hlt">ultra</span>-pure cellulose fibers into polyamides. This has been a difficult procedure and has taken years of trial and error to understand the viscosity shear heating effects associated with compounding cellulose into high-melting point engineering thermoplastics. The evolution of the low...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19770939','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19770939"><span>Tunable multiwavelength SOA fiber laser with <span class="hlt">ultra</span>-narrow wavelength spacing based on nonlinear polarization rotation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Zuxing; Wu, Jian; Xu, Kun; Hong, Xiaobin; Lin, Jintong</p> <p>2009-09-14</p> <p>A tunable multiwavelength fiber laser with <span class="hlt">ultra</span>-narrow wavelength spacing and large wavelength number using a semiconductor optical amplifier (SOA) has been demonstrated. Intensity-dependent transmission induced by nonlinear polarization rotation in the SOA accounts for <span class="hlt">stable</span> multiwavelength operation with wavelength spacing less than the homogenous broadening linewidth of the SOA. <span class="hlt">Stable</span> multiwavelength lasing with wavelength spacing as small as 0.08 nm and wavelength number up to 126 is achieved at room temperature. Moreover, wavelength tuning of 20.2 nm is implemented via polarization tuning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130009790','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130009790"><span>NASA Tech Briefs, Februrary 2013</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2013-01-01</p> <p>Topics covered include: Measurements of <span class="hlt">Ultra-Stable</span> <span class="hlt">Oscillator</span> (<span class="hlt">USO</span>) Allan Deviations in Space; Gaseous Nitrogen Orifice Mass Flow Calculator; Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards; Rover Low Gain Antenna Qualification for Deep Space Thermal Environments; Automated, <span class="hlt">Ultra</span>-Sterile Solid Sample Handling and Analysis on a Chip; Measuring and Estimating Normalized Contrast in Infrared Flash Thermography; Spectrally and Radiometrically <span class="hlt">Stable</span>, Wideband, Onboard Calibration Source; High-Reliability Waveguide Vacuum/Pressure Window; Methods of Fabricating Scintillators With Radioisotopes for Beta Battery Applications; Magnetic Shield for Adiabatic Demagnetization Refrigerators (ADR); CMOS-Compatible SOI MESFETS for Radiation-Hardened DC-to-DC Converters; Silicon Heat Pipe Array; Adaptive Phase Delay Generator; High-Temperature, Lightweight, Self-Healing Ceramic Composites for Aircraft Engine Applications; Treatment to Control Adhesion of Silicone-Based Elastomers; High-Temperature Adhesives for Thermally <span class="hlt">Stable</span> Aero-Assist Technologies; Rockballer Sample Acquisition Tool; Rock Gripper for Sampling, Mobility, Anchoring, and Manipulation; Advanced Magnetic Materials Methods and Numerical Models for Fluidization in Microgravity and Hypogravity; Data Transfer for Multiple Sensor Networks Over a Broad Temperature Range; Using Combustion Synthesis to Reinforce Berms and Other Regolith Structures; Visible-Infrared Hyperspectral Image Projector; Three-Axis Attitude Estimation With a High-Bandwidth Angular Rate Sensor Change_Detection.m; AGATE: Adversarial Game Analysis for Tactical Evaluation; Ionospheric Simulation System for Satellite Observations and Global Assimilative; Modeling Experiments (ISOGAME); An Extensible, User- Modifiable Framework for Planning Activities; Mission Operations Center (MOC) - Precipitation Processing System (PPS) Interface Software System (MPISS); Automated 3D Damaged Cavity Model Builder for Lower</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014sptz.prop11016C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014sptz.prop11016C"><span>SMUVS: Spitzer Matching survey of the <span class="hlt">Ultra</span>VISTA <span class="hlt">ultra</span>-deep Stripes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caputi, Karina; Ashby, Matthew; Fazio, Giovanni; Huang, Jiasheng; Dunlop, James; Franx, Marijn; Le Fevre, Olivier; Fynbo, Johan; McCracken, Henry; Milvang-Jensen, Bo; Muzzin, Adam; Ilbert, Olivier; Somerville, Rachel; Wechsler, Risa; Behroozi, Peter; Lu, Yu</p> <p>2014-12-01</p> <p>We request 2026.5 hours to homogenize the matching <span class="hlt">ultra</span>-deep IRAC data of the <span class="hlt">Ultra</span>VISTA <span class="hlt">ultra</span>-deep stripes, producing a final area of ~0.6 square degrees with the deepest near- and mid-IR coverage existing in any such large area of the sky (H, Ks, [3.6], [4.5] ~ 25.3-26.1 AB mag; 5 sigma). The <span class="hlt">Ultra</span>VISTA <span class="hlt">ultra</span>-deep stripes are contained within the larger COSMOS field, which has a rich collection of multi-wavelength, ancillary data, making it ideal to study different aspects of galaxy evolution with high statistical significance and excellent redshift accuracy. The <span class="hlt">Ultra</span>VISTA <span class="hlt">ultra</span>-deep stripes are the region of the COSMOS field where these studies can be pushed to the highest redshifts, but securely identifying high-z galaxies, and determining their stellar masses, will only be possible if <span class="hlt">ultra</span>-deep mid-IR data are available. Our IRAC observations will allow us to: 1) extend the galaxy stellar mass function at redshifts z=3 to z=5 to the intermediate mass regime (M~5x10^9-10^10 Msun), which is critical to constrain galaxy formation models; 2) gain a factor of six in the area where it is possible to effectively search for z>=6 galaxies and study their properties; 3) measure, for the first time, the large-scale structure traced by an unbiased galaxy sample at z=5 to z=7, and make the link to their host dark matter haloes. This cannot be done in any other field of the sky, as the <span class="hlt">Ultra</span>VISTA <span class="hlt">ultra</span>-deep stripes form a quasi-contiguous, regular-shape field, which has a unique combination of large area and photometric depth. 4) provide a unique resource for the selection of secure z>5 targets for JWST and ALMA follow up. Our observations will have an enormous legacy value which amply justifies this new observing-time investment in the COSMOS field. Spitzer cannot miss this unique opportunity to open up a large 0.6 square-degree window to the early Universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...630535M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...630535M"><span>Controlling the phase locking of stochastic magnetic bits for <span class="hlt">ultra</span>-low power computation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mizrahi, Alice; Locatelli, Nicolas; Lebrun, Romain; Cros, Vincent; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Querlioz, Damien; Grollier, Julie</p> <p>2016-07-01</p> <p>When fabricating magnetic memories, one of the main challenges is to maintain the bit stability while downscaling. Indeed, for magnetic volumes of a few thousand nm3, the energy barrier between magnetic configurations becomes comparable to the thermal energy at room temperature. Then, switches of the magnetization spontaneously occur. These volatile, superparamagnetic nanomagnets are generally considered useless. But what if we could use them as low power computational building blocks? Remarkably, they can <span class="hlt">oscillate</span> without the need of any external dc drive, and despite their stochastic nature, they can beat in unison with an external periodic signal. Here we show that the phase locking of superparamagnetic tunnel junctions can be induced and suppressed by electrical noise injection. We develop a comprehensive model giving the conditions for synchronization, and predict that it can be achieved with a total energy cost lower than 10-13 J. Our results open the path to <span class="hlt">ultra</span>-low power computation based on the controlled synchronization of <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27457034','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27457034"><span>Controlling the phase locking of stochastic magnetic bits for <span class="hlt">ultra</span>-low power computation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mizrahi, Alice; Locatelli, Nicolas; Lebrun, Romain; Cros, Vincent; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Querlioz, Damien; Grollier, Julie</p> <p>2016-07-26</p> <p>When fabricating magnetic memories, one of the main challenges is to maintain the bit stability while downscaling. Indeed, for magnetic volumes of a few thousand nm(3), the energy barrier between magnetic configurations becomes comparable to the thermal energy at room temperature. Then, switches of the magnetization spontaneously occur. These volatile, superparamagnetic nanomagnets are generally considered useless. But what if we could use them as low power computational building blocks? Remarkably, they can <span class="hlt">oscillate</span> without the need of any external dc drive, and despite their stochastic nature, they can beat in unison with an external periodic signal. Here we show that the phase locking of superparamagnetic tunnel junctions can be induced and suppressed by electrical noise injection. We develop a comprehensive model giving the conditions for synchronization, and predict that it can be achieved with a total energy cost lower than 10(-13) J. Our results open the path to <span class="hlt">ultra</span>-low power computation based on the controlled synchronization of <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24139920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24139920"><span>New insights into mechanisms of sonothrombolysis using <span class="hlt">ultra</span>-high-speed imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Xucai; Leeman, Jonathan E; Wang, Jianjun; Pacella, John J; Villanueva, Flordeliza S</p> <p>2014-01-01</p> <p>Thrombotic arterial occlusion is the principal etiology for acute cardiovascular syndromes such as stroke, myocardial infarction and unstable angina. Exposing the thrombus to ultrasound and microbubbles facilitates thrombus disruption, making "sonothrombolysis" a potentially powerful therapeutic strategy for thromboembolic diseases. However, optimization of such a strategy, and hence clinical translation, is constrained by an incomplete understanding of mechanisms by which ultrasound-induced microbubble vibrations disrupt blood clots. We posit that previously reported sonothrombolytic efficacy using inertial cavitation regimes was due, at least in part, to mechanical clot disruption by <span class="hlt">oscillating</span> microbubbles. To test this hypothesis, we optically characterized lipid microbubble interactions with thrombus in the presence of ultrasound using a recently developed <span class="hlt">ultra</span>-high-speed microscopy imaging system to visualize microbubble acoustic behaviors at megahertz frame rates. A microscope/acoustic stage designed for the system allowed an experimentally created thrombus and microbubbles to be insonified at a co-localized acoustic and optical focus during synchronized high-speed imaging. Under inertial cavitation conditions, large-amplitude microbubble <span class="hlt">oscillations</span> caused thrombus deformation and pitting. Acoustic radiation forces (Bjerknes forces) further augmented microbubble-thrombus interaction. These observations suggest that a direct mechanical effect of <span class="hlt">oscillating</span> lipid microbubbles on an adjacent thrombus may play a role in mediating clot disruption in the presence of specific ultrasound conditions. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvE..83c6206P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvE..83c6206P"><span>Adaptive <span class="hlt">oscillator</span> networks with conserved overall coupling: Sequential firing and near-synchronized states</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Picallo, Clara B.; Riecke, Hermann</p> <p>2011-03-01</p> <p>Motivated by recent observations in neuronal systems we investigate all-to-all networks of nonidentical <span class="hlt">oscillators</span> with adaptive coupling. The adaptation models spike-timing-dependent plasticity in which the sum of the weights of all incoming links is conserved. We find multiple phase-locked states that fall into two classes: near-synchronized states and splay states. Among the near-synchronized states are states that <span class="hlt">oscillate</span> with a frequency that depends only very weakly on the coupling strength and is essentially given by the frequency of one of the <span class="hlt">oscillators</span>, which is, however, neither the fastest nor the slowest <span class="hlt">oscillator</span>. In sufficiently large networks the adaptive coupling is found to develop effective network topologies dominated by one or two loops. This results in a multitude of <span class="hlt">stable</span> splay states, which differ in their firing sequences. With increasing coupling strength their frequency increases linearly and the <span class="hlt">oscillators</span> become less synchronized. The essential features of the two classes of states are captured analytically in perturbation analyses of the extended Kuramoto model used in the simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28835352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28835352"><span>Dendrites fragmentation induced by <span class="hlt">oscillating</span> cavitation bubbles in ultrasound field.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, S; Kang, J; Zhang, X; Guo, Z</p> <p>2018-02-01</p> <p>The fragmentation of the dendrites of succinonitrile (SCN)-2-wt.% acetone organic transparent alloy caused by ultrasound-induced cavitation bubbles was studied by using <span class="hlt">ultra</span>-high-speed digital camera with a rate of 40,000fps. Real-time imaging reveals that the vibrating cavitation bubbles can fragment not only secondary arms but also the primary ones under high ultrasound power. The secondary arms always broke at their roots as a result of stress concentration induced by <span class="hlt">oscillated</span> cavitation bubble and then ripped off from their primary arms. Generally the fragment process takes tens of milliseconds from bending to breaking, while the break always occurs immediately in less than 25μs. Copyright © 2017. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000057031','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000057031"><span>High-Q Microsphere Cavity for Laser Stabilization and Optoelectronic Microwave <span class="hlt">Oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ilchenko, Vladimir S.; Yao, X. Steve; Maleki, Lute</p> <p>2000-01-01</p> <p>With submillimeter size and optical Q up to approximately 10 (exp 10), microspheres with whispering-gallery (WG) modes are attractive new component for fiber-optics/photonics applications and a potential core in <span class="hlt">ultra</span>-compact high-spectral-purity optical and microwave <span class="hlt">oscillators</span>. In addition to earlier demonstrated optical locking of diode laser to WG mode in a microsphere, we report on microsphere application in the microwave optoelectronic <span class="hlt">oscillator</span>, OEO. In OEO, a steady-state microwave modulation of optical carrier is obtained in a closed loop including electro-optical modulator, fiber-optic delay, detector and microwave amplifier. OEO demonstrates exceptionally low phase noise (-140 dBc/Hz at l0kHz from approximately 10GHz carrier) with a fiber length approximately 2km. Current technology allows to put all parts of the OEO, except the fiber, on the same chip. Microspheres, with their demonstrated Q equivalent to a kilometer fiber storage, can replace fiber delays in a truly integrated device. We have obtained microwave <span class="hlt">oscillation</span> in microsphere-based OEO at 5 to 18 GHz, with 1310nm and 1550nm optical carrier, in two configurations: 1) with external DFB pump laser, and 2) with a ring laser including microsphere and a fiber optic amplifier. Also reported is a simple and efficient fiber coupler for microspheres facilitating their integration with existing fiber optics devices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CNSNS..43..330G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CNSNS..43..330G"><span>Nonlinear <span class="hlt">oscillations</span> in a muscle pacemaker cell model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González-Miranda, J. M.</p> <p>2017-02-01</p> <p>This article presents a numerical simulation study of the nonlinear <span class="hlt">oscillations</span> displayed by the Morris-Lecar model [Biophys. J. 35 (1981) 193] for the <span class="hlt">oscillations</span> experimentally observed in the transmembrane potential of a muscle fiber subject to an external electrical stimulus. We consider the model in the case when there is no external stimulation, aiming to establish the ability of the model to display biophysically reasonable pacemaker dynamics. We obtain 2D bifurcation diagrams showing that indeed the model presents oscillatory dynamics, displaying the two main types of action potentials that are observed in muscle fibers. The results obtained are shown to be structurally <span class="hlt">stable</span>; that is, robust against changes in the values of system parameters. Moreover, it is demonstrated how the model is appropriate to analyze the action potentials observed in terms of the transmembrane currents creating them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Chaos..28c3109S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Chaos..28c3109S"><span>Quenching <span class="hlt">oscillating</span> behaviors in fractional coupled Stuart-Landau <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Zhongkui; Xiao, Rui; Yang, Xiaoli; Xu, Wei</p> <p>2018-03-01</p> <p><span class="hlt">Oscillation</span> quenching has been widely studied during the past several decades in fields ranging from natural sciences to engineering, but investigations have so far been restricted to <span class="hlt">oscillators</span> with an integer-order derivative. Here, we report the first study of amplitude death (AD) in fractional coupled Stuart-Landau <span class="hlt">oscillators</span> with partial and/or complete conjugate couplings to explore <span class="hlt">oscillation</span> quenching patterns and dynamics. It has been found that the fractional-order derivative impacts the AD state crucially. The area of the AD state increases along with the decrease of the fractional-order derivative. Furthermore, by introducing and adjusting a limiting feedback factor in coupling links, the AD state can be well tamed in fractional coupled <span class="hlt">oscillators</span>. Hence, it provides one an effective approach to analyze and control the <span class="hlt">oscillating</span> behaviors in fractional coupled <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://archive.defense.gov/home/features/2012/0412_uso','SCIGOVWS'); return false;" href="http://archive.defense.gov/home/features/2012/0412_uso"><span>Defense.gov Special Report: Travels with Winnefeld: <span class="hlt">USO</span> Tour</span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>: <em><span class="hlt">USO</span></em> April 2012 Top Stories <em><span class="hlt">USO</span></em> Tour Brings Ramstein Troops, Families Together Service members and <em><span class="hlt">USO</span></em> celebrities paid a surprise visit to wounded warriors at an aeromedical staging facility on Ramstein Air Base in Germany. Story <em><span class="hlt">USO</span></em> Spring Tour Entertains Troops in Afghanistan Nearly 400 excited</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanos...814411D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanos...814411D"><span><span class="hlt">Ultra</span>-small lipid-polymer hybrid nanoparticles for tumor-penetrating drug delivery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dehaini, Diana; Fang, Ronnie H.; Luk, Brian T.; Pang, Zhiqing; Hu, Che-Ming J.; Kroll, Ashley V.; Yu, Chun Lai; Gao, Weiwei; Zhang, Liangfang</p> <p>2016-07-01</p> <p>Lipid-polymer hybrid nanoparticles, consisting of a polymeric core coated by a layer of lipids, are a class of highly scalable, biodegradable nanocarriers that have shown great promise in drug delivery applications. Here, we demonstrate the facile synthesis of <span class="hlt">ultra</span>-small, sub-25 nm lipid-polymer hybrid nanoparticles using an adapted nanoprecipitation approach and explore their utility for targeted delivery of a model chemotherapeutic. The fabrication process is first optimized to produce a monodisperse population of particles that are <span class="hlt">stable</span> under physiological conditions. It is shown that these <span class="hlt">ultra</span>-small hybrid nanoparticles can be functionalized with a targeting ligand on the surface and loaded with drug inside the polymeric matrix. Further, the in vivo fate of the nanoparticles after intravenous injection is characterized by examining the blood circulation and biodistribution. In a final proof-of-concept study, targeted <span class="hlt">ultra</span>-small hybrid nanoparticles loaded with the cancer drug docetaxel are used to treat a mouse tumor model and demonstrate improved efficacy compared to a clinically available formulation of the drug. The ability to synthesize a significantly smaller version of the established lipid-polymer hybrid platform can ultimately enhance its applicability across a wider range of applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950016570','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950016570"><span>Neurodynamic <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Espinosa, Ismael; Gonzalez, Hortensia; Quiza, Jorge; Gonazalez, J. Jesus; Arroyo, Ruben; Lara, Ritaluz</p> <p>1995-01-01</p> <p><span class="hlt">Oscillation</span> of electrical activity has been found in many nervous systems, from invertebrates to vertebrates including man. There exists experimental evidence of very simple circuits with the capability of <span class="hlt">oscillation</span>. Neurons with intrinsic <span class="hlt">oscillation</span> have been found and also neural circuits where <span class="hlt">oscillation</span> is a property of the network. These two types of <span class="hlt">oscillations</span> coexist in many instances. It is nowadays hypothesized that behind synchronization and <span class="hlt">oscillation</span> there is a system of coupled <span class="hlt">oscillators</span> responsible for activities that range from locomotion and feature binding in vision to control of sleep and circadian rhythms. The huge knowledge that has been acquired on <span class="hlt">oscillators</span> from the times of Lord Rayleigh has made the simulation of neural <span class="hlt">oscillators</span> a very active endeavor. This has been enhanced with more recent physiological findings about small neural circuits by means of intracellular and extracellular recordings as well as imaging methods. The future of this interdisciplinary field looks very promising; some researchers are going into quantum mechanics with the idea of trying to provide a quantum description of the brain. In this work we describe some simulations using neuron models by means of which we form simple neural networks that have the capability of <span class="hlt">oscillation</span>. We analyze the oscillatory activity with root locus method, cross-correlation histograms, and phase planes. In the more complicated neural network models there is the possibility of chaotic oscillatory activity and we study that by means of Lyapunov exponents. The companion paper shows an example of that kind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1291228-phase-selective-entrainment-nonlinear-oscillator-ensembles','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1291228-phase-selective-entrainment-nonlinear-oscillator-ensembles"><span>Phase-selective entrainment of nonlinear <span class="hlt">oscillator</span> ensembles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Zlotnik, Anatoly V.; Nagao, Raphael; Kiss, Istvan Z.; ...</p> <p>2016-03-18</p> <p>The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological <span class="hlt">oscillator</span> ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create <span class="hlt">stable</span> phase patterns in ensembles of heterogeneous nonlinear <span class="hlt">oscillators</span> without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups intomore » spatiotemporal patterns with multiple phase clusters. As a result, the experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1291228','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1291228"><span>Phase-selective entrainment of nonlinear <span class="hlt">oscillator</span> ensembles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zlotnik, Anatoly V.; Nagao, Raphael; Kiss, Istvan Z.</p> <p></p> <p>The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological <span class="hlt">oscillator</span> ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create <span class="hlt">stable</span> phase patterns in ensembles of heterogeneous nonlinear <span class="hlt">oscillators</span> without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups intomore » spatiotemporal patterns with multiple phase clusters. As a result, the experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5706731','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5706731"><span>A coupled-<span class="hlt">oscillator</span> model of olfactory bulb gamma <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2017-01-01</p> <p>The olfactory bulb transforms not only the information content of the primary sensory representation, but also its underlying coding metric. High-variance, slow-timescale primary odor representations are transformed by bulbar circuitry into secondary representations based on principal neuron spike patterns that are tightly regulated in time. This emergent fast timescale for signaling is reflected in gamma-band local field potentials, presumably serving to efficiently integrate olfactory sensory information into the temporally regulated information networks of the central nervous system. To understand this transformation and its integration with interareal coordination mechanisms requires that we understand its fundamental dynamical principles. Using a biophysically explicit, multiscale model of olfactory bulb circuitry, we here demonstrate that an inhibition-coupled intrinsic <span class="hlt">oscillator</span> framework, pyramidal resonance interneuron network gamma (PRING), best captures the diversity of physiological properties exhibited by the olfactory bulb. Most importantly, these properties include global zero-phase synchronization in the gamma band, the phase-restriction of informative spikes in principal neurons with respect to this common clock, and the robustness of this synchronous oscillatory regime to multiple challenging conditions observed in the biological system. These conditions include substantial heterogeneities in afferent activation levels and excitatory synaptic weights, high levels of uncorrelated background activity among principal neurons, and spike frequencies in both principal neurons and interneurons that are irregular in time and much lower than the gamma frequency. This coupled cellular <span class="hlt">oscillator</span> architecture permits <span class="hlt">stable</span> and replicable ensemble responses to diverse sensory stimuli under various external conditions as well as to changes in network parameters arising from learning-dependent synaptic plasticity. PMID:29140973</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29292364','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29292364"><span><span class="hlt">Ultra</span>-thin MoS<sub>2</sub> coated Ag@Si nanosphere arrays as efficient and <span class="hlt">stable</span> photocathode for solar-driven hydrogen production.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Qingwei; Su, Shaoqiang; Hu, Die; Lin, Lin; Yan, Zhibo; Gao, Xingsen; Zhang, Zhang; Liu, Junming</p> <p>2018-01-02</p> <p>Solar-driven photoelectrochemical (PEC) water splitting has recently attracted much attention. Silicon (Si) is an ideal light absorber for solar energy conversion. However, the poor stability and inefficient surface catalysis of Si photocathode for hydrogen evolution reaction (HER) have been remained as the key challenges. Alternatively, MoS2 has been reported to exhibit the excellent catalysis performance if sufficient active sites for the HER are available. Here, <span class="hlt">ultra</span>-thin MoS2 nanoflakes are directly synthesized to coat on the arrays of Ag-core Si-shell nanospheres (Ag@Si NSs) using the chemical vapor deposition (CVD). Due to the high surface area ratio and large curvature of these NSs, the as-grown MoS2 nanoflakes can accommodate more active sites. Meanwhile, the high-quality coating of MoS2 nanoflakes on the Ag@Si NSs protects the photocathode from damage during the PEC reaction. A high efficiency with a photocurrent of 33.3 mA cm-2 at a voltage of -0.4 V vs. the reversible hydrogen electrode is obtained. The as-prepared nanostructure as hydrogen photocathode is evidenced to have high stability over 12 hour PEC performance. This work opens opportunities for composite photocathode with high activity and stability using cheap and <span class="hlt">stable</span> co-catalysts. © 2017 IOP Publishing Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23188314','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23188314"><span><span class="hlt">Ultra-stable</span> long distance optical frequency distribution using the Internet fiber network.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lopez, Olivier; Haboucha, Adil; Chanteau, Bruno; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Giorgio</p> <p>2012-10-08</p> <p>We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The <span class="hlt">stable</span> frequency optical signal is processed enabling uninterrupted propagation on both directions. The robustness and the performance of the link are enhanced by a cost effective fully automated optoelectronic station. This device is able to coherently regenerate the return optical signal with a heterodyne optical phase locking of a low noise laser diode. Moreover the incoming signal polarization variation are tracked and processed in order to maintain beat note amplitudes within the operation range. <span class="hlt">Stable</span> fibered optical interferometer enables optical detection of the link round trip phase signal. The phase-noise compensated link shows a fractional frequency instability in 10 Hz bandwidth of 5 × 10(-15) at one second measurement time and 2 × 10(-19) at 30,000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RJPCA..91.2525B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RJPCA..91.2525B"><span>Intermittent Chaos in the Bray-Liebhafsky <span class="hlt">Oscillator</span>. Dependence of Dynamic States on the Iodate Concentration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bubanja, I. N.; Ivanović-Šašić, A.; Čupić, Ž.; Anić, S.; Kolar-Anić, Lj.</p> <p>2017-12-01</p> <p>Chaotic dynamic states with intermittent <span class="hlt">oscillations</span> were generated in a Bray-Liebhafsky (BL) oscillatory reaction in an isothermal open reactor i.e., in the continuously-fed well-stirred tank reactor (CSTR) when the inflow concentration of potassium iodate was the control parameter. They are found between periodic <span class="hlt">oscillations</span> obtained when [KIO3]0 < 3.00 × 10-2 M and <span class="hlt">stable</span> steady states when [KIO3]0 > 4.10 × 10-2 M. It was shown that the most chaotic states obtained experimentally somewhere in the middle of this region are in high correlation with results obtained by means of largest Lyapunov exponents and phenomenological analysis based on the quantitative characteristics of intermittent <span class="hlt">oscillations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhyA..392.3755D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhyA..392.3755D"><span>Optimality and <span class="hlt">oscillations</span> near the edge of stability in the dynamics of autonomous vehicle platoons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, L. C.</p> <p>2013-09-01</p> <p>A model that includes the mechanical response of a vehicle to a demanded change in acceleration is analyzed to determine the string stability of a platoon of autonomous vehicles. The response is characterized by a first-order time constant τ and an explicit delay td. The minimum value of the acceleration feedback control gain is found from calculations of the velocity of vehicles following a lead vehicle that decelerates sharply from high speed to low speed. Larger values of ξ (in the <span class="hlt">stable</span> range) give larger values of deceleration for vehicles in the platoon. Optimal operation is attained close to the minimum value of ξ for stability. Small <span class="hlt">oscillations</span> are found after the main peak in deceleration for ξ in the <span class="hlt">stable</span> region but near the transition to instability. A theory for predicting the frequency and amplitude of the <span class="hlt">oscillations</span> is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012594','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012594"><span>Early <span class="hlt">Oscillation</span> Detection Technique for Hybrid DC/DC Converters</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Bright L.</p> <p>2011-01-01</p> <p><span class="hlt">Oscillation</span> or instability is a situation that must be avoided for reliable hybrid DC/DC converters. A real-time electronics measurement technique was developed to detect catastrophic <span class="hlt">oscillations</span> at early stages for hybrid DC/DC converters. It is capable of identifying low-level <span class="hlt">oscillation</span> and determining the degree of the <span class="hlt">oscillation</span> at a unique frequency for every individual model of the converters without disturbing their normal operations. This technique is specially developed for space-used hybrid DC/DC converters, but it is also suitable for most of commercial and military switching-mode power supplies. This is a weak-electronic-signal detection technique to detect hybrid DC/DC converter <span class="hlt">oscillation</span> presented as a specific noise signal at power input pins. It is based on principles of feedback control loop <span class="hlt">oscillation</span> and RF signal modulations, and is realized by using signal power spectral analysis. On the power spectrum, a channel power amplitude at characteristic frequency (CPcf) and a channel power amplitude at switching frequency (CPsw) are chosen as <span class="hlt">oscillation</span> level indicators. If the converter is <span class="hlt">stable</span>, the CPcf is a very small pulse and the CPsw is a larger, clear, single pulse. At early stage of <span class="hlt">oscillation</span>, the CPcf increases to a certain level and the CPsw shows a small pair of sideband pulses around it. If the converter <span class="hlt">oscillates</span>, the CPcf reaches to a higher level and the CPsw shows more high-level sideband pulses. A comprehensive stability index (CSI) is adopted as a quantitative measure to accurately assign a degree of stability to a specific DC/DC converter. The CSI is a ratio of normal and abnormal power spectral density, and can be calculated using specified and measured CPcf and CPsw data. The novel and unique feature of this technique is the use of power channel amplitudes at characteristic frequency and switching frequency to evaluate stability and identify <span class="hlt">oscillations</span> at an early stage without interfering with a DC/DC converter s</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.111y1603G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.111y1603G"><span>Experimental study of a flexible and environmentally <span class="hlt">stable</span> electroadhesive device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, J.; Bamber, T.; Singh, J.; Manby, D.; Bingham, P. A.; Justham, L.; Petzing, J.; Penders, J.; Jackson, M.</p> <p>2017-12-01</p> <p>Electroadhesion is a promising adhesion mechanism for robotics and material handling applications due to several distinctive advantages it has over existing technologies. These advantages include enhanced adaptability, gentle/flexible handling, reduced complexity, and <span class="hlt">ultra</span>-low energy consumption. Unstable electroadhesive forces, however, can arise in ambient environments. Electroadhesive devices that can produce <span class="hlt">stable</span> forces in changing environments are thus desirable. In this study, a flexible and environmentally <span class="hlt">stable</span> electroadhesive device was designed and manufactured by conformally coating a layer of barium titanate dielectric on a chemically etched thin copper laminate. The results, obtained from an advanced electroadhesive "normal force" testing platform, show that only a relative difference of 5.94% in the normal force direction was observed. This was achieved when the relative humidity changed from 25% to 53%, temperature from 13.7 °C to 32.8 °C, and atmospheric pressure from 999 hPa to 1016.9 hPa. This environmentally <span class="hlt">stable</span> electroadhesive device may promote the application of the electroadhesion technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.410..799W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.410..799W"><span><span class="hlt">Ultra</span>-wideband microwave photonic frequency downconverter based on carrier-suppressed single-sideband modulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yunxin; Li, Jingnan; Wang, Dayong; Zhou, Tao; Xu, Jiahao; Zhong, Xin; Yang, Dengcai; Rong, Lu</p> <p>2018-03-01</p> <p>An <span class="hlt">ultra</span>-wideband microwave photonic frequency downconverter is proposed based on carrier-suppressed single-sideband (CS-SSB) modulation. A radio frequency (RF) signal and a local <span class="hlt">oscillator</span> (LO) signal are combined to drive a dual-parallel Mach-Zehnder modulator (DPMZM) through the electrical 90°hybrid coupler. To break through the bandwidth limit, an optical bandpass filter (OBPF) is applied simultaneously. Then a photodetector (PD) after OBPF is used to obtain intermediate frequency (IF) signal. Experimental results demonstrate that the proposed frequency downconverter can generate the CS-SSB modulation signal from 2 to 40 GHz in optical spectrum. All the mixing spurs are completely suppressed under the noise floor in electrical spectrum, and the output IF signal possesses high purity with a suppression ratio of the undesired signals (≥40 dB). Furthermore, the multi-octave downconversion can also be implemented to satisfy the bandwidth requirement of multi-channel communication. The proposed frequency downconverter supplies an <span class="hlt">ultra</span>-wideband and high-purity alternative for the signal processing in microwave photonic applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AIPC..566..211E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AIPC..566..211E"><span>Neutrinos, <span class="hlt">ultra</span>-high-energy cosmic rays and fundamental physics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ellis, John</p> <p>2001-05-01</p> <p>In the first lecture, aspects of neutrino physics beyond the Standard Model are emphasized, including the emerging default options for atmospheric and solar neutrino <span class="hlt">oscillations</span>, namely νμ-->ντ and νe-->νμ,τ respectively, and the need to check them, the prospects opened up by the successful starts of SNO and K2K and the opportunities for future long-baseline neutrino experiments. In the second lecture, it is discussed how cosmic rays may provide opportunities for probing fundamental physics. For example, <span class="hlt">ultra</span>-high-energy cosmic rays might originate from the decays of metastable heavy particles, and astrophysical γ rays can be used to test models of quantum gravity. Both scenarios offer ways to avoid the GZK cut-off, and might best be probed using high-energy astrophysical neutrinos. .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAESc.134...29S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAESc.134...29S"><span><span class="hlt">Oscillations</span> in the Indian summer monsoon during the Holocene inferred from a <span class="hlt">stable</span> isotope record from pyrogenic carbon from Lake Chenghai, southwest China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Weiwei; Zhang, Enlou; Liu, Enfeng; Ji, Ming; Chen, Rong; Zhao, Cheng; Shen, Ji; Li, Yanling</p> <p>2017-02-01</p> <p>A robust, well-dated record of centennial-scale abrupt changes in the Asian summer monsoon is crucial for understanding the potential forcing factors and their environmental effects. In this study, we analyzed the <span class="hlt">stable</span> carbon isotopes of pyrogenic carbon (δ13CPC) in a 556-cm long sediment core retrieved from Lake Chenghai in the Yunnan Plateau, China. The results provide a continuous 7660-year precipitation record of the Indian summer monsoon (ISM). They indicate that from ∼7600 cal yr BP precipitation in the Lake Chenghai catchment gradually increased until 5030 cal yr BP, and then subsequently decreased in the second half of the Holocene. In addition, at least six centennial-scale droughts occurred at about 7300, 6300, 5500, 3400, 2500 and 500 cal yr BP. Our findings suggest that ISM intensity is primary controlled by variations in solar irradiance on a centennial time scale. This external forcing may be amplified by North Atlantic cooling events and El Niño-Southern <span class="hlt">Oscillation</span> activity in the eastern tropical Pacific, which shift the intertropical convergence zone further southwards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28375242','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28375242"><span><span class="hlt">Stable</span> L-band multi-wavelength SOA fiber laser based on polarization rotation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Tonghui; Jia, Dongfang; Yang, Tianxin; Wang, Zhaoying; Liu, Ying</p> <p>2017-04-01</p> <p>We propose and experimentally demonstrate a <span class="hlt">stable</span> multi-wavelength fiber ring laser operating in the L-band with wavelength spacing of 25 GHz. The mechanism is induced by a polarization rotation intensity equalizer consisting of a semiconductor optical amplifier and polarization devices. A Fabry-Perot filter is inserted into the cavity to serve as a multi-wavelength selection device. <span class="hlt">Stable</span> L-band multi-wavelength lasing with 3 dB uniformity of 21.2 nm, and simultaneous <span class="hlt">oscillation</span> of 101 lines with wavelength spacing of 25 GHz, is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=331273','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=331273"><span>Generation and stabilization of whey-based monodisperse naoemulsions using <span class="hlt">ultra</span>-high pressure homogenization and small amphipathic co-emulsifier combinations</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p><span class="hlt">Ultra</span>-high-pressure homogenization (UHPH) was used to generate monodisperse <span class="hlt">stable</span> peanut oil nanoemulsions within a desired nanosize range (<100 nm) (DNR) stabilized using combinations of whey protein concentrate (WPC), sodium dodecyl sulfate, Triton X-100 (X100), and zwitterionic sulfobetaine-base...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850052525&hterms=pollen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpollen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850052525&hterms=pollen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpollen"><span>Does the ocean-atmosphere system have more than one <span class="hlt">stable</span> mode of operation?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Broecker, W. S.; Peteet, D. M.; Rind, D.</p> <p>1985-01-01</p> <p>The climate record obtained from two long Greenland ice cores reveals several brief climate <span class="hlt">oscillations</span> during glacial time. The most recent of these <span class="hlt">oscillations</span>, also found in continental pollen records, has greatest impact in the area under the meteorological influence of the northern Atlantic, but none in the United States. This suggests that these <span class="hlt">oscillations</span> are caused by fluctuations in the formation rate of deep water in the northern Atlantic. As the present production of deep water in this area is driven by an excess of evaporation over precipitation and continental runoff, atmospheric water transport may be an important element in climate change. Changes in the production rate of deep water in this sector of the ocean may push the climate system from one quasi-<span class="hlt">stable</span> mode of operation to another.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJB...90..132B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJB...90..132B"><span>Resurgence of <span class="hlt">oscillation</span> in coupled <span class="hlt">oscillators</span> under delayed cyclic interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bera, Bidesh K.; Majhi, Soumen; Ghosh, Dibakar</p> <p>2017-07-01</p> <p>This paper investigates the emergence of amplitude death and revival of <span class="hlt">oscillations</span> from the suppression states in a system of coupled dynamical units interacting through delayed cyclic mode. In order to resurrect the <span class="hlt">oscillation</span> from amplitude death state, we introduce asymmetry and feedback parameter in the cyclic coupling forms as a result of which the death region shrinks due to higher asymmetry and lower feedback parameter values for coupled oscillatory systems. Some analytical conditions are derived for amplitude death and revival of <span class="hlt">oscillations</span> in two coupled limit cycle <span class="hlt">oscillators</span> and corresponding numerical simulations confirm the obtained theoretical results. We also report that the death state and revival of <span class="hlt">oscillations</span> from quenched state are possible in the network of identical coupled <span class="hlt">oscillators</span>. The proposed mechanism has also been examined using chaotic Lorenz <span class="hlt">oscillator</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998A%26A...339..225V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998A%26A...339..225V"><span>The effect of delays on filament <span class="hlt">oscillations</span> and stability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van den Oord, G. H. J.; Schutgens, N. A. J.; Kuperus, M.</p> <p>1998-11-01</p> <p>We discuss the linear response of a filament to perturbations, taking the finite communication time between the filament and the photosphere into account. The finite communication time introduces delays in the system. Recently Schutgens (1997ab) investigated the solutions of the delay equation for vertical perturbations. In this paper we expand his analysis by considering also horizontal and coupled <span class="hlt">oscillations</span>. The latter occur in asymmetric coronal fields. We also discuss the effect of Alfven wave emission on filament <span class="hlt">oscillations</span> and show that wave emission is important for stabilizing filaments. We introduce a fairly straightforward method to study the solutions of delay equations as a function of the filament-photosphere communication time. A solution can be described by a linear combination of damped harmonic <span class="hlt">oscillations</span> each characterized by a frequency, a damping/growth time and, accordingly, a quality factor. As a secondary result of our analysis we show that, within the context of line current models, Kippenhahn/Schlüter-type filament equilibria can never be <span class="hlt">stable</span> in the horizontal and the vertical direction at the same time but we also demonstrate that Kuperus/Raadu-type equilibria can account for both an inverse or a normal polarity signature. The diagnostic value of our analysis for determining, e.g., the filament current from observations of <span class="hlt">oscillating</span> filaments is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JaJAP..46.5865O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JaJAP..46.5865O"><span>Linearly Polarized Single-Frequency <span class="hlt">Oscillations</span> of Laser-Diode-Pumped Microchip Ceramic Nd:YAG Lasers with Forced Ince-Gaussian Mode Operations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Otsuka, Kenju; Nemoto, Kana; Kamikariya, Koji; Miyasaka, Yoshihiko; Chu, Shu-Chun</p> <p>2007-09-01</p> <p>Detailed <span class="hlt">oscillation</span> spectra and polarization properties have been examined in laser-diode-pumped (LD-pumped) microchip ceramic (i.e., polycrystalline) Nd:YAG lasers and the inherent segregation of lasing patterns into local modes possessing different polarization states was observed. Single-frequency linearly-polarized <span class="hlt">stable</span> <span class="hlt">oscillations</span> were realized by forcing the laser to Ince-Gaussian mode operations by adjusting azimuthal cavity symmetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AIPC..676..230T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AIPC..676..230T"><span>Control of <span class="hlt">Oscillation</span> Patterns in a Symmetric Coupled Biological <span class="hlt">Oscillator</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takamatsu, Atsuko; Tanaka, Reiko; Yamamoto, Takatoki; Fujii, Teruo</p> <p>2003-08-01</p> <p>A chain of three-<span class="hlt">oscillator</span> system was constructed with living biological <span class="hlt">oscillators</span> of phasmodial slime mold, Physarum polycehalum and the <span class="hlt">oscillation</span> patterns were analyzed by the symmetric Hopf bifurcation theory using group theory. Multi-stability of <span class="hlt">oscillation</span> patterns was observed, even when the coupling strength was fixed. This suggests that the coupling strength is not an effective parameter to obtain a desired <span class="hlt">oscillation</span> pattern among the multiple patterns. Here we propose a method to control <span class="hlt">oscillation</span> patterns using resonance to external stimulus and demonstrate pattern switching induced by frequency resonance given to only one of <span class="hlt">oscillators</span> in the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JChPh.148c4901M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JChPh.148c4901M"><span><span class="hlt">Ultra</span>-fast relaxation, decoherence, and localization of photoexcited states in π-conjugated polymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mannouch, Jonathan R.; Barford, William; Al-Assam, Sarah</p> <p>2018-01-01</p> <p>The exciton relaxation dynamics of photoexcited electronic states in poly(p-phenylenevinylene) are theoretically investigated within a coarse-grained model, in which both the exciton and nuclear degrees of freedom are treated quantum mechanically. The Frenkel-Holstein Hamiltonian is used to describe the strong exciton-phonon coupling present in the system, while external damping of the internal nuclear degrees of freedom is accounted for by a Lindblad master equation. Numerically, the dynamics are computed using the time evolving block decimation and quantum jump trajectory techniques. The values of the model parameters physically relevant to polymer systems naturally lead to a separation of time scales, with the <span class="hlt">ultra</span>-fast dynamics corresponding to energy transfer from the exciton to the internal phonon modes (i.e., the C-C bond <span class="hlt">oscillations</span>), while the longer time dynamics correspond to damping of these phonon modes by the external dissipation. Associated with these time scales, we investigate the following processes that are indicative of the system relaxing onto the emissive chromophores of the polymer: (1) Exciton-polaron formation occurs on an <span class="hlt">ultra</span>-fast time scale, with the associated exciton-phonon correlations present within half a vibrational time period of the C-C bond <span class="hlt">oscillations</span>. (2) Exciton decoherence is driven by the decay in the vibrational overlaps associated with exciton-polaron formation, occurring on the same time scale. (3) Exciton density localization is driven by the external dissipation, arising from "wavefunction collapse" occurring as a result of the system-environment interactions. Finally, we show how fluorescence anisotropy measurements can be used to investigate the exciton decoherence process during the relaxation dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..333B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..333B"><span>Heat transfer nanofluid based on curly <span class="hlt">ultra</span>-long multi-wall carbon nanotubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boncel, Sławomir; Zniszczoł, Aurelia; Pawlyta, Mirosława; Labisz, Krzysztof; Dzido, Grzegorz</p> <p>2018-02-01</p> <p>The main challenge in the use of multi-wall carbon nanotube (MWCNT) as key components of nanofluids is to transfer excellent thermal properties from individual nanotubes into the bulk systems. We present studies on the performance of heat transfer nanofluids based on <span class="hlt">ultra</span>-long ( 2 mm), curly MWCNTs - in the background of various other nanoC-sp2, i.e. oxidized MWCNTs, commercially available Nanocyl™ MWCNTs and spherical carbon nanoparticles (SCNs). The nanofluids prepared via ultrasonication from water and propylene glycol were studied in terms of heat conductivity and heat transfer in a scaled up thermal circuit containing a copper helical heat exchanger. <span class="hlt">Ultra</span>-long curly MWCNT (1 wt.%) nanofluids (stabilized with Gum Arabic in water) emerged as the most thermally conducting ones with a 23-30%- and 39%-enhancement as compared to the base-fluids for water and propylene glycol, respectively. For turbulent flows ( Re = 8000-11,000), the increase of heat transfer coefficient for the over-months <span class="hlt">stable</span> 1 wt.% <span class="hlt">ultra</span>-long MWCNT nanofluid was found as high as >100%. The findings allow to confirm that longer MWCNTs are promising solid components in nanofluids and hence to predict their broader application in heat transfer media.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22596390-synchronization-mobile-chaotic-oscillator-networks','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22596390-synchronization-mobile-chaotic-oscillator-networks"><span>Synchronization of mobile chaotic <span class="hlt">oscillator</span> networks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Fujiwara, Naoya, E-mail: fujiwara@csis.u-tokyo.ac.jp; Kurths, Jürgen; Díaz-Guilera, Albert</p> <p></p> <p>We study synchronization of systems in which agents holding chaotic <span class="hlt">oscillators</span> move in a two-dimensional plane and interact with nearby ones forming a time dependent network. Due to the uncertainty in observing other agents' states, we assume that the interaction contains a certain amount of noise that turns out to be relevant for chaotic dynamics. We find that a synchronization transition takes place by changing a control parameter. But this transition depends on the relative dynamic scale of motion and interaction. When the topology change is slow, we observe an intermittent switching between laminar and burst states close to themore » transition due to small noise. This novel type of synchronization transition and intermittency can happen even when complete synchronization is linearly <span class="hlt">stable</span> in the absence of noise. We show that the linear stability of the synchronized state is not a sufficient condition for its stability due to strong fluctuations of the transverse Lyapunov exponent associated with a slow network topology change. Since this effect can be observed within the linearized dynamics, we can expect such an effect in the temporal networks with noisy chaotic <span class="hlt">oscillators</span>, irrespective of the details of the <span class="hlt">oscillator</span> dynamics. When the topology change is fast, a linearized approximation describes well the dynamics towards synchrony. These results imply that the fluctuations of the finite-time transverse Lyapunov exponent should also be taken into account to estimate synchronization of the mobile contact networks.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10013E..14E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10013E..14E"><span><span class="hlt">Ultra</span>-bright emission from hexagonal boron nitride defects as a new platform for bio-imaging and bio-labelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elbadawi, Christopher; Tran, Trong Toan; Shimoni, Olga; Totonjian, Daniel; Lobo, Charlene J.; Grosso, Gabriele; Moon, Hyowan; Englund, Dirk R.; Ford, Michael J.; Aharonovich, Igor; Toth, Milos</p> <p>2016-12-01</p> <p>Bio-imaging requires robust <span class="hlt">ultra</span>-bright probes without causing any toxicity to the cellular environment, maintain their stability and are chemically inert. In this work we present hexagonal boron nitride (hBN) nanoflakes which exhibit narrowband <span class="hlt">ultra</span>-bright single photon emitters1. The emitters are optically <span class="hlt">stable</span> at room temperature and under ambient environment. hBN has also been noted to be noncytotoxic and seen significant advances in functionalization with biomolecules2,3. We further demonstrate two methods of engineering this new range of extremely robust multicolour emitters across the visible and near infrared spectral ranges for large scale sensing and biolabeling applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24182009','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24182009"><span>Chemical <span class="hlt">oscillator</span> as a generalized Rayleigh <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghosh, Shyamolina; Ray, Deb Shankar</p> <p>2013-10-28</p> <p>We derive the conditions under which a set of arbitrary two dimensional autonomous kinetic equations can be reduced to the form of a generalized Rayleigh <span class="hlt">oscillator</span> which admits of limit cycle solution. This is based on a linear transformation of field variables which can be found by inspection of the kinetic equations. We illustrate the scheme with the help of several chemical and bio-chemical <span class="hlt">oscillator</span> models to show how they can be cast as a generalized Rayleigh <span class="hlt">oscillator</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29339832','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29339832"><span>CLOCKΔ19 mutation modifies the manner of synchrony among <span class="hlt">oscillation</span> neurons in the suprachiasmatic nucleus.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sujino, Mitsugu; Asakawa, Takeshi; Nagano, Mamoru; Koinuma, Satoshi; Masumoto, Koh-Hei; Shigeyoshi, Yasufumi</p> <p>2018-01-16</p> <p>In mammals, the principal circadian <span class="hlt">oscillator</span> exists in the hypothalamic suprachiasmatic nucleus (SCN). In the SCN, CLOCK works as an essential component of molecular circadian <span class="hlt">oscillation</span>, and ClockΔ19 mutant mice show unique characteristics of circadian rhythms such as extended free running periods, amplitude attenuation, and high-magnitude phase-resetting responses. Here we investigated what modifications occur in the spatiotemporal organization of clock gene expression in the SCN of ClockΔ19 mutants. The cultured SCN, sampled from neonatal homozygous ClockΔ19 mice on an ICR strain comprising PERIOD2::LUCIFERASE, demonstrated that the Clock gene mutation not only extends the circadian period, but also affects the spatial phase and period distribution of circadian <span class="hlt">oscillations</span> in the SCN. In addition, disruption of the synchronization among neurons markedly attenuated the amplitude of the circadian rhythm of individual <span class="hlt">oscillating</span> neurons in the mutant SCN. Further, with numerical simulations based on the present studies, the findings suggested that, in the SCN of the ClockΔ19 mutant mice, <span class="hlt">stable</span> <span class="hlt">oscillation</span> was preserved by the interaction among <span class="hlt">oscillating</span> neurons, and that the orderly phase and period distribution that makes a phase wave are dependent on the functionality of CLOCK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009861','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009861"><span>Nature's Autonomous <span class="hlt">Oscillators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.</p> <p>2012-01-01</p> <p>Nonlinearity is required to produce autonomous <span class="hlt">oscillations</span> without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum <span class="hlt">oscillating</span> at the resonance frequency. Among nature's observed autonomous <span class="hlt">oscillators</span>, examples are the quasi-biennial <span class="hlt">oscillation</span> and bimonthly <span class="hlt">oscillation</span> of the Earth atmosphere, and the 22-year solar <span class="hlt">oscillation</span>. The <span class="hlt">oscillations</span> have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the <span class="hlt">oscillations</span>, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency <span class="hlt">oscillation</span> of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear <span class="hlt">oscillator</span>. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical <span class="hlt">oscillators</span> and the human heart physiology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3695550','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3695550"><span>A Self-Synchronized Optoelectronic <span class="hlt">Oscillator</span> based on an RTD Photo-Detector and a Laser Diode</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Romeira, Bruno; Seunarine, Kris; Ironside, Charles N.; Kelly, Anthony E.; Figueiredo, José M. L.</p> <p>2013-01-01</p> <p>We propose and demonstrate a simple and <span class="hlt">stable</span> low-phase noise optoelectronic <span class="hlt">oscillator</span> (OEO) that uses a laser diode, an optical fiber delay line and a resonant tunneling diode (RTD) free-running <span class="hlt">oscillator</span> that is monolithic integrated with a waveguide photo-detector. The RTD-OEO exhibits single-side band phase noise power below −100 dBc/Hz with more than 30 dB noise suppression at 10 kHz from the center free-running frequency for fiber loop lengths around 1.2 km. The <span class="hlt">oscillator</span> power consumption is below 0.55 W, and can be controlled either by the injected optical power or the fiber delay line. The RTD-OEO stability is achieved without using other high-speed optical/optoelectronic components and amplification. PMID:23814452</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/992944','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/992944"><span>Thermometric- and Acoustic-Based Beam Power Monitor for <span class="hlt">Ultra</span>-Bright X-Rays</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bentsen, Gregory; /Rochester U. /SLAC</p> <p>2010-08-25</p> <p>A design for an average beam power monitor for <span class="hlt">ultra</span>-bright X-ray sources is proposed that makes simultaneous use of calorimetry and radiation acoustics. Radiation incident on a solid target will induce heating and ultrasonic vibrations, both of which may be measured to give a fairly precise value of the beam power. The monitor is intended for measuring <span class="hlt">ultra</span>-bright Free-Electron Laser (FEL) X-ray beams, for which traditional monitoring technologies such as photo-diodes or scintillators are unsuitable. The monitor consists of a Boron Carbide (B{sub 4}C) target designed to absorb most of the incident beam's energy. Resistance temperature detectors (RTD) and piezoelectricmore » actuators are mounted on the outward faces of the target to measure the temperature changes and ultrasonic vibrations induced by the incident beam. The design was tested using an optical pulsed beam (780 nm, 120 and 360 Hz) from a Ti:sapphire <span class="hlt">oscillator</span> at several energies between 0.8 and 2.6 mJ. The RTDs measured an increase in temperature of about 10 K over a period of several minutes. The piezoelectric sensors recorded ringing acoustic <span class="hlt">oscillations</span> at 580 {+-} 40 kHz. Most importantly, the amplitude of the acoustic signals was observed to scale linearly with beam power up to 2 mJ of pulse energy. Above this pulse energy, the vibrational signals became nonlinear. Several causes for this nonlinearity are discussed, including amplifier saturation and piezoelectric saturation. Despite this nonlinearity, these measurements demonstrate the feasibility of such a beam power measurement device. The advantage of two distinct measurements (acoustic and thermometric) provides a useful method of calibration that is unavailable to current LCLS diagnostics tools.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NatPh...8..190T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NatPh...8..190T"><span>Sculpting <span class="hlt">oscillators</span> with light within a nonlinear quantum fluid</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tosi, G.; Christmann, G.; Berloff, N. G.; Tsotsis, P.; Gao, T.; Hatzopoulos, Z.; Savvidis, P. G.; Baumberg, J. J.</p> <p>2012-03-01</p> <p>Seeing macroscopic quantum states directly remains an elusive goal. Particles with boson symmetry can condense into quantum fluids, producing rich physical phenomena as well as proven potential for interferometric devices. However, direct imaging of such quantum states is only fleetingly possible in high-vacuum ultracold atomic condensates, and not in superconductors. Recent condensation of solid-state polariton quasiparticles, built from mixing semiconductor excitons with microcavity photons, offers monolithic devices capable of supporting room-temperature quantum states that exhibit superfluid behaviour. Here we use microcavities on a semiconductor chip supporting two-dimensional polariton condensates to directly visualize the formation of a spontaneously <span class="hlt">oscillating</span> quantum fluid. This system is created on the fly by injecting polaritons at two or more spatially separated pump spots. Although <span class="hlt">oscillating</span> at tunable THz frequencies, a simple optical microscope can be used to directly image their <span class="hlt">stable</span> archetypal quantum <span class="hlt">oscillator</span> wavefunctions in real space. The self-repulsion of polaritons provides a solid-state quasiparticle that is so nonlinear as to modify its own potential. Interference in time and space reveals the condensate wavepackets arise from non-equilibrium solitons. Control of such polariton-condensate wavepackets demonstrates great potential for integrated semiconductor-based condensate devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27003466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27003466"><span><span class="hlt">Ultra</span>-flexible nanocarriers for enhanced topical delivery of a highly lipophilic antioxidative molecule for skin cancer chemoprevention.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boakye, Cedar H A; Patel, Ketan; Doddapaneni, Ravi; Bagde, Arvind; Behl, Gautam; Chowdhury, Nusrat; Safe, Stephen; Singh, Mandip</p> <p>2016-07-01</p> <p>In this study, we developed cationic <span class="hlt">ultra</span>-flexible nanocarriers (<span class="hlt">Ultra</span>FLEX-Nano) to surmount the skin barrier structure and to potentiate the topical delivery of a highly lipophilic antioxidative diindolylmethane derivative (DIM-D) for the inhibition of UV-induced DNA damage and skin carcinogenesis. <span class="hlt">Ultra</span>FLEX-Nano was prepared with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dioleoyl-3-trimethylammonium-propane, cholesterol and tween-80 by ethanolic injection method; was characterized by Differential Scanning Calorimetric (DSC), Fourier Transform Infrared (FT-IR) and Atomic Force Microscopic (phase-imaging) analyses and permeation studies were performed in dermatomed human skin. The efficacy of DIM-D-<span class="hlt">Ultra</span>FLEX-Nano for skin cancer chemoprevention was evaluated in UVB-induced skin cancer model in vivo. DIM-D-<span class="hlt">Ultra</span>FLEX-Nano formed a <span class="hlt">stable</span> mono-dispersion (110.50±0.71nm) with >90% encapsulation of DIM-D that was supported by HPLC, DSC, FT-IR and AFM phase imaging. The blank formulation was non-toxic to human embryonic kidney cells. <span class="hlt">Ultra</span>FLEX-Nano was vastly deformable and highly permeable across the stratum corneum; there was significant (p<0.01) skin deposition of DIM-D for <span class="hlt">Ultra</span>FLEX-Nano that was superior to PEG solution (13.83-fold). DIM-D-<span class="hlt">Ultra</span>FLEX-Nano pretreatment delayed the onset of UVB-induced tumorigenesis (2 weeks) and reduced (p<0.05) the number of tumors observed in SKH-1 mice (3.33-fold), which was comparable to pretreatment with sunscreen (SPF30). Also, DIM-D-<span class="hlt">Ultra</span>FLEX-Nano caused decrease (p<0.05) in UV-induced DNA damage (8-hydroxydeoxyguanosine), skin inflammation (PCNA), epidermal hyperplasia (c-myc, CyclinD1), immunosuppression (IL10), cell survival (AKT), metastasis (Vimentin, MMP-9, TIMP1) but increase in apoptosis (p53 and p21). <span class="hlt">Ultra</span>FLEX-Nano was efficient in enhancing the topical delivery of DIM-D. DIM-D-<span class="hlt">Ultra</span>FLEX-Nano was efficacious in delaying skin tumor incidence and multiplicity in SKH mice comparable to sunscreen (SPF30</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptCo.332..187L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptCo.332..187L"><span>980 nm all-fiber NPR mode-locking Yb-doped phosphate fiber <span class="hlt">oscillator</span> and its amplifier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Pingxue; Yao, Yifei; Chi, Junjie; Hu, Haowei; Yang, Chun; Zhao, Ziqiang; Zhang, Guangju</p> <p>2014-12-01</p> <p>We report on a 980 nm all-fiber passively mode-locking Yb-doped phosphate fiber <span class="hlt">oscillator</span> with the nonlinear polarization rotation (NPR) technique and its amplifier. In order to obtaining the <span class="hlt">stable</span> self-starting mode-locking <span class="hlt">oscillator</span> at 980 nm, a bandpass filter with 30 nm transmission bandwidth around 980 nm is inserted into the cavity. The <span class="hlt">oscillator</span> generates the average output power of 26.1 mW with the repetition rate of 20.38 MHz, corresponding to the single pulse energy of 1.28 nJ. The pulse width is 159.48 ps. The output spectrum of the pulses is centered at 977 nm with a full width half maximum (FWHM) of 10 nm and has the characteristic steep spectral edges of dissipative soliton. No undesired ASE and harmful <span class="hlt">oscillation</span> around 1030 nm is observed. Moreover, through two stage all-fiber-integrated amplifier by using the 980 nm <span class="hlt">oscillator</span> as seed source, an amplified output power of 205 mW at 980 nm and pulse duration of 178.10 ps is achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29632301','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29632301"><span>Designable <span class="hlt">ultra</span>-smooth <span class="hlt">ultra</span>-thin solid-electrolyte interphases of three alkali metal anodes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gu, Yu; Wang, Wei-Wei; Li, Yi-Juan; Wu, Qi-Hui; Tang, Shuai; Yan, Jia-Wei; Zheng, Ming-Sen; Wu, De-Yin; Fan, Chun-Hai; Hu, Wei-Qiang; Chen, Zhao-Bin; Fang, Yuan; Zhang, Qing-Hong; Dong, Quan-Feng; Mao, Bing-Wei</p> <p>2018-04-09</p> <p>Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates <span class="hlt">ultra</span>-smooth <span class="hlt">ultra</span>-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the <span class="hlt">ultra</span>-smooth <span class="hlt">ultra</span>-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm -2 with 100% depth of discharge. Our work illustrates that an <span class="hlt">ultra</span>-smooth <span class="hlt">ultra</span>-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...815684G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...815684G"><span>One-Year <span class="hlt">stable</span> perovskite solar cells by 2D/3D interface engineering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; de Angelis, F.; Graetzel, M.; Nazeeruddin, Mohammad Khaja</p> <p>2017-06-01</p> <p>Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly <span class="hlt">stable</span> under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year <span class="hlt">stable</span> perovskite devices by engineering an <span class="hlt">ultra-stable</span> 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency <span class="hlt">stable</span> for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative <span class="hlt">stable</span> and low-cost architecture will enable the timely commercialization of perovskite solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5461484','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5461484"><span>One-Year <span class="hlt">stable</span> perovskite solar cells by 2D/3D interface engineering</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; De Angelis, F.; Graetzel, M.; Nazeeruddin, Mohammad Khaja</p> <p>2017-01-01</p> <p>Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly <span class="hlt">stable</span> under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year <span class="hlt">stable</span> perovskite devices by engineering an <span class="hlt">ultra-stable</span> 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency <span class="hlt">stable</span> for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative <span class="hlt">stable</span> and low-cost architecture will enable the timely commercialization of perovskite solar cells. PMID:28569749</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28569749','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28569749"><span>One-Year <span class="hlt">stable</span> perovskite solar cells by 2D/3D interface engineering.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grancini, G; Roldán-Carmona, C; Zimmermann, I; Mosconi, E; Lee, X; Martineau, D; Narbey, S; Oswald, F; De Angelis, F; Graetzel, M; Nazeeruddin, Mohammad Khaja</p> <p>2017-06-01</p> <p>Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly <span class="hlt">stable</span> under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year <span class="hlt">stable</span> perovskite devices by engineering an <span class="hlt">ultra-stable</span> 2D/3D (HOOC(CH 2 ) 4 NH 3 ) 2 PbI 4 /CH 3 NH 3 PbI 3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm 2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency <span class="hlt">stable</span> for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative <span class="hlt">stable</span> and low-cost architecture will enable the timely commercialization of perovskite solar cells.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3722033','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3722033"><span><span class="hlt">Ultra</span>-pure, water-dispersed Au nanoparticles produced by femtosecond laser ablation and fragmentation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kubiliūtė, Reda; Maximova, Ksenia A; Lajevardipour, Alireza; Yong, Jiawey; Hartley, Jennifer S; Mohsin, Abu SM; Blandin, Pierre; Chon, James WM; Sentis, Marc; Stoddart, Paul R; Kabashin, Andrei; Rotomskis, Ričardas; Clayton, Andrew HA; Juodkazis, Saulius</p> <p>2013-01-01</p> <p>Aqueous solutions of <span class="hlt">ultra</span>-pure gold nanoparticles have been prepared by methods of femtosecond laser ablation from a solid target and fragmentation from already formed colloids. Despite the absence of protecting ligands, the solutions could be (1) fairly <span class="hlt">stable</span> and poly size-dispersed; or (2) very <span class="hlt">stable</span> and monodispersed, for the two fabrication modalities, respectively. Fluorescence quenching behavior and its intricacies were revealed by fluorescence lifetime imaging microscopy in rhodamine 6G water solution. We show that surface-enhanced Raman scattering of rhodamine 6G on gold nanoparticles can be detected with high fidelity down to micromolar concentrations using the nanoparticles. Application potential of pure gold nanoparticles with polydispersed and nearly monodispersed size distributions are discussed. PMID:23888114</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112j3101E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112j3101E"><span>Room temperature microwave <span class="hlt">oscillations</span> in GaN/AlN resonant tunneling diodes with peak current densities up to 220 kA/cm2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Encomendero, Jimy; Yan, Rusen; Verma, Amit; Islam, S. M.; Protasenko, Vladimir; Rouvimov, Sergei; Fay, Patrick; Jena, Debdeep; Xing, Huili Grace</p> <p>2018-03-01</p> <p>We report the generation of room temperature microwave <span class="hlt">oscillations</span> from GaN/AlN resonant tunneling diodes, which exhibit record-high peak current densities. The tunneling heterostructure grown by molecular beam epitaxy on freestanding GaN substrates comprises a thin GaN quantum well embedded between two AlN tunneling barriers. The room temperature current-voltage characteristics exhibit a record-high maximum peak current density of ˜220 kA/cm2. When biased within the negative differential conductance region, microwave <span class="hlt">oscillations</span> are measured with a fundamental frequency of ˜0.94 GHz, generating an output power of ˜3.0 μW. Both the fundamental frequency and the output power of the <span class="hlt">oscillator</span> are limited by the external biasing circuit. Using a small-signal equivalent circuit model, the maximum intrinsic frequency of <span class="hlt">oscillation</span> for these diodes is predicted to be ˜200 GHz. This work represents a significant step towards microwave power generation enabled by resonant tunneling transport, an <span class="hlt">ultra</span>-fast process that goes beyond the limitations of current III-Nitride high electron mobility transistors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20875980','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20875980"><span>An <span class="hlt">ultra</span>-compact and low-power oven-controlled crystal <span class="hlt">oscillator</span> design for precision timing applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lim, Jaehyun; Kim, Hyunsoo; Jackson, Thomas; Choi, Kyusun; Kenny, David</p> <p>2010-09-01</p> <p>A novel design for a chip-scale miniature oven-controlled crystal <span class="hlt">oscillator</span> (OCXO) is presented. In this design, all the main components of an OCXO--consisting of an <span class="hlt">oscillator</span>, a temperature sensor, a heater, and temperature-control circuitry--are integrated on a single CMOS chip. The OCXO package size can be reduced significantly with this design, because the resonator does not require a separate package and most of the circuitry is integrated on a single CMOS chip. Other characteristics such as power consumption and warm-up time are also improved. Two different types of quartz resonators, an AT-cut tab mesa-type quartz crystal and a frame enclosed resonator, allow miniaturization of the OCXO structure. Neither of these quartz resonator types requires a separate package inside the oven structure; therefore, they can each be directly integrated with the custom-designed CMOS chip. The miniature OCXO achieves a frequency stability of +/- 0.35 ppm with an AT-cut tab mesa-type quartz crystal in the temperature range of 0 °C to 60 °C. The maximum power consumption of this miniature OCXO is 1.2 W at start-up and 303 mW at steady state. The warm-up time to reach the steady state is 190 s. These results using the proposed design are better than or the same as high-frequency commercial OCXOs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27136667','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27136667"><span>Interplay between non-NMDA and NMDA receptor activation during oscillatory wave propagation: Analyses of caffeine-induced <span class="hlt">oscillations</span> in the visual cortex of rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoshimura, Hiroshi; Sugai, Tokio; Kato, Nobuo; Tominaga, Takashi; Tominaga, Yoko; Hasegawa, Takahiro; Yao, Chenjuan; Akamatsu, Tetsuya</p> <p>2016-07-01</p> <p>Generation and propagation of oscillatory activities in cortical networks are important features of the brain. However, many issues related to oscillatory phenomena are unclear. We previously reported neocortical <span class="hlt">oscillation</span> following caffeine treatment of rat brain slices. Input to the primary visual cortex (Oc1) generates N-methyl-d-aspartate (NMDA) receptor-dependent <span class="hlt">oscillations</span>, and we proposed that the oscillatory signals originate in the secondary visual cortex (Oc2). Because non-NMDA and NMDA receptors cooperate in synaptic transmission, non-NMDA receptors may also play an important role in oscillatory activities. Here we investigated how non-NMDA receptor activities contribute to NMDA receptor-dependent <span class="hlt">oscillations</span> by using optical recording methods. After induction of <span class="hlt">stable</span> <span class="hlt">oscillations</span> with caffeine application, blockade of NMDA receptors abolished the late <span class="hlt">stable</span> oscillatory phase, but elicited 'hidden' non-NMDA receptor-dependent <span class="hlt">oscillation</span> during the early depolarizing phase. An interesting finding is that the origin of the non-NMDA receptor-dependent <span class="hlt">oscillation</span> moved from the Oc1, during the early phase, toward the origin of the NMDA receptor-dependent <span class="hlt">oscillation</span> that is fixed in the Oc2. In addition, the frequency of the non-NMDA receptor-dependent <span class="hlt">oscillation</span> was higher than that of the NMDA receptor-dependent <span class="hlt">oscillation</span>. Thus, in one course of spatiotemporal oscillatory activities, the relative balance in receptor activities between non-NMDA and NMDA receptors gradually changes, and this may be due to the different kinetics of the two receptor types. These results suggest that interplay between the two receptor types in the areas of Oc1 and Oc2 may play an important role in oscillatory signal communication. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5477489','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5477489"><span>Mesoscopic chaos mediated by Drude electron-hole plasma in silicon optomechanical <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Jiagui; Huang, Shu-Wei; Huang, Yongjun; Zhou, Hao; Yang, Jinghui; Liu, Jia-Ming; Yu, Mingbin; Lo, Guoqiang; Kwong, Dim-Lee; Duan, Shukai; Wei Wong, Chee</p> <p>2017-01-01</p> <p>Chaos has revolutionized the field of nonlinear science and stimulated foundational studies from neural networks, extreme event statistics, to physics of electron transport. Recent studies in cavity optomechanics provide a new platform to uncover quintessential architectures of chaos generation and the underlying physics. Here, we report the generation of dynamical chaos in silicon-based monolithic optomechanical <span class="hlt">oscillators</span>, enabled by the strong and coupled nonlinearities of two-photon absorption induced Drude electron–hole plasma. Deterministic chaotic <span class="hlt">oscillation</span> is achieved, and statistical and entropic characterization quantifies the chaos complexity at 60 fJ intracavity energies. The correlation dimension D2 is determined at 1.67 for the chaotic attractor, along with a maximal Lyapunov exponent rate of about 2.94 times the fundamental optomechanical <span class="hlt">oscillation</span> for fast adjacent trajectory divergence. Nonlinear dynamical maps demonstrate the subharmonics, bifurcations and <span class="hlt">stable</span> regimes, along with distinct transitional routes into chaos. This provides a CMOS-compatible and scalable architecture for understanding complex dynamics on the mesoscopic scale. PMID:28598426</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090004675','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090004675"><span>Performance of MEMS Silicon <span class="hlt">Oscillator</span>, ASFLM1, under Wide Operating Temperature Range</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patterson, Richard L.; Hammoud, Ahmad</p> <p>2008-01-01</p> <p>Over the last few years, MEMS (Micro-Electro-Mechanical Systems) resonator-based <span class="hlt">oscillators</span> began to be offered as commercial-off-the-shelf (COTS) parts by a few companies [1-2]. These quartz-free, miniature silicon devices could compete with the traditional crystal <span class="hlt">oscillators</span> in providing the timing (clock function) for many digital and analog electronic circuits. They provide <span class="hlt">stable</span> output frequency, offer great tolerance to shock and vibration, and are immune to electro-static discharge [1-2]. In addition, they are encapsulated in compact lead-free packages, cover a wide frequency range (1 MHz to 125 MHz), and are specified, depending on the grade, for extended temperature operation from -40 C to +85 C. The small size of the MEMS <span class="hlt">oscillators</span> along with their reliability and thermal stability make them candidates for use in space exploration missions. Limited data, however, exist on the performance and reliability of these devices under operation in applications where extreme temperatures or thermal cycling swings, which are typical of space missions, are encountered. This report presents the results of the work obtained on the evaluation of an ABRACON Corporation MEMS silicon <span class="hlt">oscillator</span> chip, type ASFLM1, under extreme temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4333530','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4333530"><span>SHOCK-EXCITED <span class="hlt">OSCILLATOR</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Creveling, R.</p> <p>1957-12-17</p> <p>S> A shock-excited quartz crystal <span class="hlt">oscillator</span> is described. The circuit was specifically designed for application in micro-time measuring work to provide an <span class="hlt">oscillator</span> which immediately goes into <span class="hlt">oscillation</span> upon receipt of a trigger pulse and abruptly ceases <span class="hlt">oscillation</span> when a second pulse is received. To achieve the instant action, the crystal has a prestressing voltage applied across it. A monostable multivibrator receives the on and off trigger pulses and discharges a pulse through the crystal to initiate or terminate <span class="hlt">oscillation</span> instantly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Chaos..28c3606S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Chaos..28c3606S"><span>Stochastic mixed-mode <span class="hlt">oscillations</span> in a three-species predator-prey model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sadhu, Susmita; Kuehn, Christian</p> <p>2018-03-01</p> <p>The effect of demographic stochasticity, in the form of Gaussian white noise, in a predator-prey model with one fast and two slow variables is studied. We derive the stochastic differential equations (SDEs) from a discrete model. For suitable parameter values, the deterministic drift part of the model admits a folded node singularity and exhibits a singular Hopf bifurcation. We focus on the parameter regime near the Hopf bifurcation, where small amplitude <span class="hlt">oscillations</span> exist as <span class="hlt">stable</span> dynamics in the absence of noise. In this regime, the stochastic model admits noise-driven mixed-mode <span class="hlt">oscillations</span> (MMOs), which capture the intermediate dynamics between two cycles of population outbreaks. We perform numerical simulations to calculate the distribution of the random number of small <span class="hlt">oscillations</span> between successive spikes for varying noise intensities and distance to the Hopf bifurcation. We also study the effect of noise on a suitable Poincaré map. Finally, we prove that the stochastic model can be transformed into a normal form near the folded node, which can be linked to recent results on the interplay between deterministic and stochastic small amplitude <span class="hlt">oscillations</span>. The normal form can also be used to study the parameter influence on the noise level near folded singularities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090042581','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090042581"><span>Assessment of Operation of EMK21 MEMS Silicon <span class="hlt">Oscillator</span> Over Wide Temperature Range</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patterson, Richard L.; Hammoud, Ahmad</p> <p>2009-01-01</p> <p>Electronic control systems, data-acquisition instrumentation, and microprocessors require accurate timing signals for proper operation. Traditionally, ceramic resonators and crystal <span class="hlt">oscillators</span> provided this clock function for the majority of these systems. Over the last few years, MEMS (Micro-Electro-Mechanical Systems) resonator-based <span class="hlt">oscillators</span> began to surface as commercial-off-the-shelf (COTS) parts by a few companies. These quartz-free, miniature silicon devices could easily replace the traditional crystal <span class="hlt">oscillators</span> in providing the timing/clock function for many digital and analog circuits. They are reported to provide <span class="hlt">stable</span> output frequency, offer great tolerance to shock and vibration, and are immune to electro-static discharge [ 1-2]. In addition, they are encapsulated in compact lead-free packages and cover a wide frequency range (1 MHz to 125 MHz). The small size of the MEMS <span class="hlt">oscillators</span> along with their thermal stability make them ideal candidates for use in space exploration missions. Limited data, however, exist on the performance and reliability of these devices under operation in applications where extreme temperatures or thermal cycling swings, which are typical of space missions, are encountered. This report presents the results of the work obtained on the evaluation of an Ecliptek Corporation MEMS silicon <span class="hlt">oscillator</span> chip under extreme temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869654','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3869654"><span>Behaviour of a Premixed Flame Subjected to Acoustic <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qureshi, Shafiq R.; Khan, Waqar A.; Prosser, Robert</p> <p>2013-01-01</p> <p>In this paper, a one dimensional premixed laminar methane flame is subjected to acoustic <span class="hlt">oscillations</span> and studied. The purpose of this analysis is to investigate the effects of acoustic perturbations on the reaction rates of different species, with a view to their respective contribution to thermoacoustic instabilities. Acoustically transparent non reflecting boundary conditions are employed. The flame response has been studied with acoustic waves of different frequencies and amplitudes. The integral values of the reaction rates, the burning velocities and the heat release of the acoustically perturbed flame are compared with the unperturbed case. We found that the flame's sensitivity to acoustic perturbations is greatest when the wavelength is comparable to the flame thickness. Even in this case, the perturbations are <span class="hlt">stable</span> with time. We conclude that acoustic fields acting on the chemistry do not contribute significantly to the emergence of large amplitude pressure <span class="hlt">oscillations</span>. PMID:24376501</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28029621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28029621"><span>Drifts and Environmental Disturbances in Atomic Clock Subsystems: Quantifying Local <span class="hlt">Oscillator</span>, Control Loop, and Ion Resonance Interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Enzer, Daphna G; Diener, William A; Murphy, David W; Rao, Shanti R; Tjoelker, Robert L</p> <p>2017-03-01</p> <p>Linear ion trap frequency standards are among the most <span class="hlt">stable</span> continuously operating frequency references and clocks. Depending on the application, they have been operated with a variety of local <span class="hlt">oscillators</span> (LOs), including quartz ultrastable <span class="hlt">oscillators</span>, hydrogen-masers, and cryogenic sapphire <span class="hlt">oscillators</span>. The short-, intermediate-, and long-term stability of the frequency output is a complicated function of the fundamental performances, the time dependence of environmental disturbances, the atomic interrogation algorithm, the implemented control loop, and the environmental sensitivity of the LO and the atomic system components. For applications that require moving these references out of controlled lab spaces and into less <span class="hlt">stable</span> environments, such as fieldwork or spaceflight, a deeper understanding is needed of how disturbances at different timescales impact the various subsystems of the clock and ultimately the output stability. In this paper, we analyze which perturbations have an impact and to what degree. We also report on a computational model of a control loop, which keeps the microwave source locked to the ion resonance. This model is shown to agree with laboratory measurements of how well the feedback removes various disturbances and also with a useful analytic approach we developed for predicting these impacts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJB...88..106A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJB...88..106A"><span>How a small noise generates large-amplitude <span class="hlt">oscillations</span> of volcanic plug and provides high seismicity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexandrov, Dmitri V.; Bashkirtseva, Irina A.; Ryashko, Lev B.</p> <p>2015-04-01</p> <p>A non-linear behavior of dynamic model of the magma-plug system under the action of N-shaped friction force and stochastic disturbances is studied. It is shown that the deterministic dynamics essentially depends on the mutual arrangement of an equilibrium point and the friction force branches. Variations of this arrangement imply bifurcations, birth and disappearance of <span class="hlt">stable</span> limit cycles, changes of the stability of equilibria, system transformations between mono- and bistable regimes. A slope of the right increasing branch of the friction function is responsible for the formation of such regimes. In a bistable zone, the noise generates transitions between small and large amplitude stochastic <span class="hlt">oscillations</span>. In a monostable zone with single <span class="hlt">stable</span> equilibrium, a new dynamic phenomenon of noise-induced generation of large amplitude stochastic <span class="hlt">oscillations</span> in the plug rate and pressure is revealed. A beat-type dynamics of the plug displacement under the influence of stochastic forcing is studied as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19980009733&hterms=superconducting+gravity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsuperconducting%2Bgravity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19980009733&hterms=superconducting+gravity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsuperconducting%2Bgravity"><span>The Superconducting Cavity Stabilized <span class="hlt">Oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Turneaure, J. P.; Buchman, Saps; Lipa, John</p> <p>1997-01-01</p> <p>Superconducting Cavity Stabilized <span class="hlt">Oscillators</span> (SCSOs) have produced the most <span class="hlt">stable</span> clocks to date for integration times between 10(exp 2) and 10(exp 3) seconds, achieving a fractional frequency stability of 2 x 10(exp -16) for a sampling time of 100 s. The principal contributors to cavity frequency variations are: (1) acceleration effects due to gravity and vibrations; (2) temperature variations; (3) variations in the energy stored in the cavity; and (4) noise introduced by the frequency stabilization circuit. We discuss the prospects for improvements in all these areas for both ground-based and space-based SCSOs, which may lead to SCSOs with fractional frequency stabilities below 10(exp -17). SCSOs of this frequency stability will be useful for testing fundamental physical principles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJC...76..544N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJC...76..544N"><span>From <span class="hlt">stable</span> to unstable anomaly-induced inflation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Netto, Tibério de Paula; Pelinson, Ana M.; Shapiro, Ilya L.; Starobinsky, Alexei A.</p> <p>2016-10-01</p> <p>Quantum effects derived through conformal anomaly lead to an inflationary model that can be either <span class="hlt">stable</span> or unstable. The unstable version requires a large dimensionless coefficient of about 5× {10}^8 in front of the {R}^2 term that results in the inflationary regime in the R+{R}^2 ("Starobinsky") model being a generic intermediate attractor. In this case the non-local terms in the effective action are practically irrelevant, and there is a `graceful exit' to a low curvature matter-like dominated stage driven by high-frequency <span class="hlt">oscillations</span> of R - scalarons, which later decay to pairs of all particles and antiparticles, with the amount of primordial scalar (density) perturbations required by observations. The <span class="hlt">stable</span> version is a genuine generic attractor, so there is no exit from it. We discuss a possible transition from <span class="hlt">stable</span> to unstable phases of inflation. It is shown that this transition is automatic if the sharp cut-off approximation is assumed for quantum corrections in the period of transition. Furthermore, we describe two different quantum mechanisms that may provide a required large {R}^2-term in the transition period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25623139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25623139"><span>Comparative analysis of monoclonal antibody N-glycosylation using <span class="hlt">stable</span> isotope labelling and UPLC-fluorescence-MS.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Millán Martín, Silvia; Delporte, Cédric; Farrell, Amy; Navas Iglesias, Natalia; McLoughlin, Niaobh; Bones, Jonathan</p> <p>2015-03-07</p> <p>A twoplex method using (12)C6 and (13)C6 <span class="hlt">stable</span> isotope analogues (Δmass = 6 Da) of 2-aminobenzoic acid (2-AA) is described for quantitative analysis of N-glycans present on monoclonal antibodies and other glycoproteins using <span class="hlt">ultra</span> performance liquid chromatography with sequential fluorescence and accurate mass tandem quadrupole time of flight (QToF) mass spectrometric detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JIMTW..38.1477O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JIMTW..38.1477O"><span>Spectral Narrowing of a Varactor-Integrated Resonant-Tunneling-Diode Terahertz <span class="hlt">Oscillator</span> by Phase-Locked Loop</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogino, Kota; Suzuki, Safumi; Asada, Masahiro</p> <p>2017-12-01</p> <p>Spectral narrowing of a resonant-tunneling-diode (RTD) terahertz <span class="hlt">oscillator</span>, which is useful for various applications of terahertz frequency range, such as an accurate gas spectroscopy, a frequency reference in various communication systems, etc., was achieved with a phase-locked loop system. The <span class="hlt">oscillator</span> is composed of an RTD, a slot antenna, and a varactor diode for electrical frequency tuning. The output of the RTD <span class="hlt">oscillating</span> at 610 GHz was down-converted to 400 MHz by a heterodyne detection. The phase noise was transformed to amplitude noise by a balanced mixer and fed back into the varactor diode. The loop filter for a <span class="hlt">stable</span> operation is discussed. The spectral linewidth of 18.6 MHz in free-running operation was reduced to less than 1 Hz by the feedback.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19068295','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19068295"><span>Compliance of <span class="hlt">Ultra</span>-Orthodox and secular pedestrians with traffic lights in <span class="hlt">Ultra</span>-Orthodox and secular locations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosenbloom, Tova; Shahar, Amit; Perlman, Amotz</p> <p>2008-11-01</p> <p>Following a previous study that revealed the disobedience of <span class="hlt">Ultra</span>-Orthodox citizens, as compared to secular citizens, of traffic lights at crosswalks, the present study examined the road habits of 995 <span class="hlt">Ultra</span>-Orthodox and secular pedestrians in neighboring <span class="hlt">Ultra</span>-Orthodox and secular cities. Using an observation grid designed specially for this study, the pedestrians were observed at two crosswalks--one in an <span class="hlt">Ultra</span>-Orthodox city and one in a secular city--as far as similar traffic parameters, using a logistic regression. The tendency to cross on a red light was assessed as a function of estimated age, gender, religiosity, location (religious/secular), the duration of the red light, the number of vehicles crossing and the number of pedestrians waiting at the curb. <span class="hlt">Ultra</span>-Orthodox pedestrians committed more violations than secular pedestrians did, and there were more road violations in the <span class="hlt">Ultra</span>-Orthodox location than there were in the secular location. Fewer traffic violations were committed by "local" pedestrians (<span class="hlt">Ultra</span>-Orthodox pedestrians in the <span class="hlt">Ultra</span>-Orthodox location and secular pedestrians in the secular location) than by "foreigners" (<span class="hlt">Ultra</span>-Orthodox pedestrians in the secular location and secular pedestrians in the <span class="hlt">Ultra</span>-Orthodox location). The odds of crossing on a red light decreased as a function of both the number of people waiting at the curb and the number of vehicles. Consistent with previous research, males crossed on red much more than females did, regardless of religiosity and location. Our discussion focuses on theoretical and practical explanations of the findings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PThPS.194..111I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PThPS.194..111I"><span>Coupled <span class="hlt">Oscillator</span> Model of the Business Cycle withFluctuating Goods Markets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ikeda, Y.; Aoyama, H.; Fujiwara, Y.; Iyetomi, H.; Ogimoto, K.; Souma, W.; Yoshikawa, H.</p> <p></p> <p>The sectoral synchronization observed for the Japanese business cycle in the Indices of Industrial Production data is an example of synchronization. The stability of this synchronization under a shock, e.g., fluctuation of supply or demand, is a matter of interest in physics and economics. We consider an economic system made up of industry sectors and goods markets in order to analyze the sectoral synchronization observed for the Japanese business cycle. A coupled <span class="hlt">oscillator</span> model that exhibits synchronization is developed based on the Kuramoto model with inertia by adding goods markets, and analytic solutions of the stationary state and the coupling strength are obtained. We simulate the effects on synchronization of a sectoral shock for systems with different price elasticities and the coupling strengths. Synchronization is reproduced as an equilibrium solution in a nearest neighbor graph. Analysis of the order parameters shows that the synchronization is <span class="hlt">stable</span> for a finite elasticity, whereas the synchronization is broken and the <span class="hlt">oscillators</span> behave like a giant <span class="hlt">oscillator</span> with a certain frequency additional to the common frequency for zero elasticity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1404724','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1404724"><span>AN <span class="hlt">OSCILLATOR</span> CONFIGURATION FOR FULL REALIZATION OF HARD X-RAY FREE ELECTRON LASER*</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kim, K.-J.; Kolodziej, T.; Lindberg, R. R.</p> <p>2017-06-01</p> <p>An x-ray free electron laser <span class="hlt">oscillator</span> (XFELO) is feasible by employing an X-ray cavity with Bragg mirrors such as diamond crystals. An XFELO at the 5th harmonic frequency may be implemented at the LCLS II using its 4 GeV superconducting linac, producing <span class="hlt">stable</span>, fully coherent, high-spectral-purity hard x-rays. In addition, its output can be a coherent seed to the LCLS amplifier for <span class="hlt">stable</span>, high-power, femto-second x-ray pulses. We summarize the recent progress in various R&D efforts addressing critical issues for realizing an XFELO at LCLS II.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7579E..1BL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7579E..1BL"><span>High-Q optical resonators: characterization and application to stabilization of lasers and high spectral purity microwave <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Llopis, O.; Merrer, P. H.; Bouchier, A.; Saleh, K.; Cibiel, G.</p> <p>2010-02-01</p> <p>Microwave optical systems for frequency generation are described in this paper. The goal is to reach high spectral purity in the microwave frequency range using <span class="hlt">ultra</span> high Q optical resonators. The resonators investigated are of two types : resonant (passive) fiber rings and WGM tridimensional resonators. They all feature <span class="hlt">ultra</span> high optical Q factors, in excess of 108 or 109 near 1550 nm. These resonators also sustain a large number of optical resonances, and the microwave signal is stabilized on two (or more) resonances of this optical comb. Different problems have to be overcome in order to reach a functional system, such as : resonator design and coupling, laser stabilization on a resonance, overall system design, noise optimization... This paper gives an overlook on these problems, and on some solutions we found to work towards a compact and efficient microwave opto-electronic <span class="hlt">oscillator</span> (OEO). A first result is presented on a 10 GHz OEO based on a resonant fiber ring.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740018619','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740018619"><span>LC-<span class="hlt">oscillator</span> with automatic stabilized amplitude via bias current control. [power supply circuit for transducers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hamlet, J. F. (Inventor)</p> <p>1974-01-01</p> <p>A <span class="hlt">stable</span> excitation supply for measurement transducers is described. It consists of a single-transistor <span class="hlt">oscillator</span> with a coil connected to the collector and a capacitor connected from the collector to the emitter. The output of the <span class="hlt">oscillator</span> is rectified and the rectified signal acts as one input to a differential amplifier; the other input being a reference potential. The output of the amplifier is connected at a point between the emitter of the transistor and ground. When the rectified signal is greater than the reference signal, the differential amplifier produces a signal of polarity to reduce bias current and, consequently, amplification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SMaS...26c5045P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SMaS...26c5045P"><span>Experimental investigation of broadband energy harvesting of a bi-<span class="hlt">stable</span> composite piezoelectric plate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, Diankun; Ma, Benbiao; Dai, Fuhong</p> <p>2017-03-01</p> <p>In this work, a bi-<span class="hlt">stable</span> vibration energy harvester is presented to scavenge energy from ambient vibrations over a wide frequency range. This bi-<span class="hlt">stable</span> harvester consists of a bi-<span class="hlt">stable</span> hybrid composite plate as host structure and several pieces of piezoelectric ceramics. Three linear harvesters with the same geometry were employed as the control samples to illustrate the advantages of this bi-<span class="hlt">stable</span> harvester. The voltage-frequency responses were measured with different g-level excitations, and the output powers across various resistances were measured at different frequencies and accelerations. Unlike the linear harvesters which are effective only near their natural frequencies, the obvious nonlinearities of this bi-<span class="hlt">stable</span> harvester broaden its working bandwidth. Additionally, the characteristics of this bi-<span class="hlt">stable</span> host structure contribute to the output power. Under the same condition, when this bi-<span class="hlt">stable</span> harvester is under cross-well <span class="hlt">oscillation</span> pattern the maximum output powers are several times higher than those of the linear harvesters. The measured highest output power of this bi-<span class="hlt">stable</span> harvester is 36.2 mW with 38 Hz frequency and 5g acceleration (g = 9.8 m s-2).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3707100','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3707100"><span>Age-related changes in <span class="hlt">ultra</span>-triathlon performances</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background The age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in <span class="hlt">ultra</span>-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron <span class="hlt">ultra</span>-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron <span class="hlt">ultra</span>-triathlon (38-km swimming, 1,800-km cycling and 420-km running). Methods The age and performances of 423 male Triple Iron <span class="hlt">ultra</span>-triathletes and 119 male Deca Iron <span class="hlt">ultra</span>-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA. Results The mean age of the finishers was significantly higher for Deca Iron <span class="hlt">ultra</span>-triathletes (41.3 ± 3.1 years) compared to a Triple Iron <span class="hlt">ultra</span>-triathletes (38.5 ± 3.3 years) (P < 0.05). For both <span class="hlt">ultra</span>-distances, the fastest overall race times were achieved between the ages of 25 and 44 years. Deca Iron <span class="hlt">ultra</span>-triathletes achieved the same level of performance in swimming and cycling between 25 and 54 years of age. Conclusions The magnitudes of age-related declines in performance in the three disciplines of <span class="hlt">ultra</span>-triathlon differ slightly between Triple and Deca Iron <span class="hlt">ultra</span>-triathlon. Although the ages of Triple Iron <span class="hlt">ultra</span>-triathletes were on average younger compared to Deca Iron <span class="hlt">ultra</span>-triathletes, the fastest race times were achieved between 25 and 44 years for both distances. Further studies should investigate the motivation and training of <span class="hlt">ultra</span>-triathletes to gain better insights in <span class="hlt">ultra</span>-triathlon performance. PMID:23849327</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Chaos..23c3126J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Chaos..23c3126J"><span>Phase locking route behind complex periodic windows in a forced <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jan, Hengtai; Tsai, Kuo-Ting; Kuo, Li-wei</p> <p>2013-09-01</p> <p>Chaotic systems have complex reactions against an external driving force; even in cases with low-dimension <span class="hlt">oscillators</span>, the routes to synchronization are diverse. We proposed a stroboscope-based method for analyzing driven chaotic systems in their phase space. According to two statistic quantities generated from time series, we could realize the system state and the driving behavior simultaneously. We demonstrated our method in a driven bi-<span class="hlt">stable</span> system, which showed complex period windows under a proper driving force. With increasing periodic driving force, a route from interior periodic <span class="hlt">oscillation</span> to phase synchronization through the chaos state could be found. Periodic windows could also be identified and the circumstances under which they occurred distinguished. Statistical results were supported by conditional Lyapunov exponent analysis to show the power in analyzing the unknown time series.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5082885','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5082885"><span>Glucose <span class="hlt">Oscillations</span> Can Activate an Endogenous <span class="hlt">Oscillator</span> in Pancreatic Islets</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mukhitov, Nikita; Roper, Michael G.; Bertram, Richard</p> <p>2016-01-01</p> <p>Pancreatic islets manage elevations in blood glucose level by secreting insulin into the bloodstream in a pulsatile manner. Pulsatile insulin secretion is governed by islet <span class="hlt">oscillations</span> such as bursting electrical activity and periodic Ca2+ entry in β-cells. In this report, we demonstrate that although islet <span class="hlt">oscillations</span> are lost by fixing a glucose stimulus at a high concentration, they may be recovered by subsequently converting the glucose stimulus to a sinusoidal wave. We predict with mathematical modeling that the sinusoidal glucose signal’s ability to recover islet <span class="hlt">oscillations</span> depends on its amplitude and period, and we confirm our predictions by conducting experiments with islets using a microfluidics platform. Our results suggest a mechanism whereby oscillatory blood glucose levels recruit non-<span class="hlt">oscillating</span> islets to enhance pulsatile insulin output from the pancreas. Our results also provide support for the main hypothesis of the Dual <span class="hlt">Oscillator</span> Model, that a glycolytic <span class="hlt">oscillator</span> endogenous to islet β-cells drives pulsatile insulin secretion. PMID:27788129</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JAP....97b3904H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JAP....97b3904H"><span>Theory of the Bloch <span class="hlt">oscillating</span> transistor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hassel, J.; Seppä, H.</p> <p>2005-01-01</p> <p>The Bloch <span class="hlt">oscillating</span> transistor (BOT) is a device in which single electron current through a normal tunnel junction enhances Cooper pair current in a mesoscopic Josephson junction, leading to signal amplification. In this article we develop a theory in which the BOT dynamics is described as a two-level system. The theory is used to predict current-voltage characteristics and small-signal response. The transition from <span class="hlt">stable</span> operation into the hysteretic regime is studied. By identifying the two-level switching noise as the main source of fluctuations, the expressions for equivalent noise sources and the noise temperature are derived. The validity of the model is tested by comparing the results with simulations and experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJST.225.2635D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJST.225.2635D"><span>Nonlinear resonance and synchronization in the ring of unidirectionally coupled Toda <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dvorak, Anton; Astakhov, Vladimir; Perlikowski, Przemyslaw; Kapitaniak, Tomasz</p> <p>2016-11-01</p> <p>In the ring of unidirectionally coupled Toda <span class="hlt">oscillators</span> the nonlinear resonance and the synchronization are investigated. It is shown how the nonlinear resonance affects the structure of the main synchronization region. As a result of nonlinear resonance we observe the coexistence of two <span class="hlt">stable</span> limit cycles near the resonant frequency, which leads to coexistence of periodic and quasi-periodic regimes within the synchronization region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23214738','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23214738"><span>Heating and thermal squeezing in parametrically driven <span class="hlt">oscillators</span> with added noise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Batista, Adriano A</p> <p>2012-11-01</p> <p>In this paper we report a theoretical model based on Green's functions, Floquet theory, and averaging techniques up to second order that describes the dynamics of parametrically driven <span class="hlt">oscillators</span> with added thermal noise. Quantitative estimates for heating and quadrature thermal noise squeezing near and below the transition line of the first parametric instability zone of the <span class="hlt">oscillator</span> are given. Furthermore, we give an intuitive explanation as to why heating and thermal squeezing occur. For small amplitudes of the parametric pump the Floquet multipliers are complex conjugate of each other with a constant magnitude. As the pump amplitude is increased past a threshold value in the <span class="hlt">stable</span> zone near the first parametric instability, the two Floquet multipliers become real and have different magnitudes. This creates two different effective dissipation rates (one smaller and the other larger than the real dissipation rate) along the <span class="hlt">stable</span> manifolds of the first-return Poincaré map. We also show that the statistical average of the input power due to thermal noise is constant and independent of the pump amplitude and frequency. The combination of these effects causes most of heating and thermal squeezing. Very good agreement between analytical and numerical estimates of the thermal fluctuations is achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhB...49g5502C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhB...49g5502C"><span>Evolution of a hybrid micro-macro entangled state of the qubit-<span class="hlt">oscillator</span> system via the generalized rotating wave approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chakrabarti, R.; Yogesh, V.</p> <p>2016-04-01</p> <p>We study the evolution of the hybrid entangled states in a bipartite (<span class="hlt">ultra</span>) strongly coupled qubit-<span class="hlt">oscillator</span> system. Using the generalized rotating wave approximation the reduced density matrices of the qubit and the <span class="hlt">oscillator</span> are obtained. The reduced density matrix of the <span class="hlt">oscillator</span> yields the phase space quasi probability distributions such as the diagonal P-representation, the Wigner W-distribution and the Husimi Q-function. In the strong coupling regime the Q-function evolves to uniformly separated macroscopically distinct Gaussian peaks representing ‘kitten’ states at certain specified times that depend on multiple time scales present in the interacting system. The ultrastrong coupling strength of the interaction triggers appearance of a large number of modes that quickly develop a randomization of their phase relationships. A stochastic averaging of the dynamical quantities sets in, and leads to the decoherence of the system. The delocalization in the phase space of the <span class="hlt">oscillator</span> is studied by using the Wehrl entropy. The negativity of the W-distribution reflects the departure of the <span class="hlt">oscillator</span> from the classical states, and allows us to study the underlying differences between various information-theoretic measures such as the Wehrl entropy and the Wigner entropy. Other features of nonclassicality such as the existence of the squeezed states and appearance of negative values of the Mandel parameter are realized during the course of evolution of the bipartite system. In the parametric regime studied here these properties do not survive in the time-averaged limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDL14004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDL14004M"><span>Self-sustained <span class="hlt">oscillations</span> of a sinusoidally-deformed plate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muriel, Diego F.; Cowen, Edwin A.</p> <p>2015-11-01</p> <p>Motivated by energy harvesting, the oscillatory motion of a deformed elastic material with aspect ratio Length/Width=2, immerse in an incompressible flow is studied experimentally. To induce the wave-like deformation a polycarbonate sheet is placed under longitudinal compression with external forcing provided by equispaced tension lines anchored in a frame. No additional constrains are placed in the material. Based on quantitative image-based edge detection, ADV, and PIV measurements, we document the existence of three natural states of motion. Bellow a critical velocity, a <span class="hlt">stable</span> state presents a sinusoidal-like deformation with weak small perturbations. Above a critical velocity, instability appears in the form of a traveling wave with predictable dominant frequency accompanied by higher-order harmonics. As the flow velocity increases the instability converges faster to its limit cycle in the phase plane (e.g., vertical velocity and position), until the <span class="hlt">stable</span> oscillatory mode transitions to chaos showing a broad energy spectrum and unstable limit cycle. The underlying objective is to induce the onset of the instability at lower critical velocities for higher bending rigidities, promoting possible energy extraction and increasing the range at which <span class="hlt">stable</span> <span class="hlt">oscillations</span> appear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4445872','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4445872"><span>What predicts performance in <span class="hlt">ultra</span>-triathlon races? – a comparison between Ironman distance triathlon and <span class="hlt">ultra</span>-triathlon</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Knechtle, Beat; Zingg, Matthias Alexander; Rosemann, Thomas; Stiefel, Michael; Rüst, Christoph Alexander</p> <p>2015-01-01</p> <p>Objective This narrative review summarizes recent intentions to find potential predictor variables for <span class="hlt">ultra</span>-triathlon race performance (ie, triathlon races longer than the Ironman distance covering 3.8 km swimming, 180 km cycling, and 42.195 km running). Results from studies on <span class="hlt">ultra</span>-triathletes were compared to results on studies on Ironman triathletes. Methods A literature search was performed in PubMed using the terms “ultra”, “triathlon”, and “performance” for the aspects of “<span class="hlt">ultra</span>-triathlon”, and “Ironman”, “triathlon”, and “performance” for the aspects of “Ironman triathlon”. All resulting papers were searched for related citations. Results for <span class="hlt">ultra</span>-triathlons were compared to results for Ironman-distance triathlons to find potential differences. Results Athletes competing in Ironman and <span class="hlt">ultra</span>-triathlon differed in anthropometric and training characteristics, where both Ironmen and <span class="hlt">ultra</span>-triathletes profited from low body fat, but <span class="hlt">ultra</span>-triathletes relied more on training volume, whereas speed during training was related to Ironman race time. The most important predictive variables for a fast race time in an <span class="hlt">ultra</span>-triathlon from Double Iron (ie, 7.6 km swimming, 360 km cycling, and 84.4 km running) and longer were male sex, low body fat, age of 35–40 years, extensive previous experience, a fast time in cycling and running but not in swimming, and origins in Central Europe. Conclusion Any athlete intending to compete in an <span class="hlt">ultra</span>-triathlon should be aware that low body fat and high training volumes are highly predictive for overall race time. Little is known about the physiological characteristics of these athletes and about female <span class="hlt">ultra</span>-triathletes. Future studies need to investigate anthropometric and training characteristics of female <span class="hlt">ultra</span>-triathletes and what motivates women to compete in these races. Future studies need to correlate physiological characteristics such as maximum oxygen uptake (VO2max) with <span class="hlt">ultra</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5992463','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5992463"><span>Physiology and Pathophysiology in <span class="hlt">Ultra</span>-Marathon Running</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Knechtle, Beat; Nikolaidis, Pantelis T.</p> <p>2018-01-01</p> <p>In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of <span class="hlt">ultra</span>-marathon running. The number of <span class="hlt">ultra</span>-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical <span class="hlt">ultra</span>-marathoner is male, married, well-educated, and ~45 years old. Female <span class="hlt">ultra</span>-marathoners account for ~20% of the total number of finishers. <span class="hlt">Ultra</span>-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in <span class="hlt">ultra</span>-marathon races and personal best marathon time) is the most important predictor variable for a successful <span class="hlt">ultra</span>-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the <span class="hlt">ultra</span>-marathon. The fastest <span class="hlt">ultra</span>-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An <span class="hlt">ultra</span>-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An <span class="hlt">ultra</span>-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An <span class="hlt">ultra</span>-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer <span class="hlt">ultra</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29910741','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29910741"><span>Physiology and Pathophysiology in <span class="hlt">Ultra</span>-Marathon Running.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knechtle, Beat; Nikolaidis, Pantelis T</p> <p>2018-01-01</p> <p>In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of <span class="hlt">ultra</span>-marathon running. The number of <span class="hlt">ultra</span>-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical <span class="hlt">ultra</span>-marathoner is male, married, well-educated, and ~45 years old. Female <span class="hlt">ultra</span>-marathoners account for ~20% of the total number of finishers. <span class="hlt">Ultra</span>-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in <span class="hlt">ultra</span>-marathon races and personal best marathon time) is the most important predictor variable for a successful <span class="hlt">ultra</span>-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10-20% depending upon the length of the <span class="hlt">ultra</span>-marathon. The fastest <span class="hlt">ultra</span>-marathon race times are generally achieved at the age of 35-45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An <span class="hlt">ultra</span>-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An <span class="hlt">ultra</span>-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An <span class="hlt">ultra</span>-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer <span class="hlt">ultra</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JEMat..44.4628L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JEMat..44.4628L"><span>Nanofiber Anisotropic Conductive Films (ACF) for <span class="hlt">Ultra</span>-Fine-Pitch Chip-on-Glass (COG) Interconnections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Sang-Hoon; Kim, Tae-Wan; Suk, Kyung-Lim; Paik, Kyung-Wook</p> <p>2015-11-01</p> <p>Nanofiber anisotropic conductive films (ACF) were invented, by adapting nanofiber technology to ACF materials, to overcome the limitations of <span class="hlt">ultra</span>-fine-pitch interconnection packaging, i.e. shorts and open circuits as a result of the narrow space between bumps and electrodes. For nanofiber ACF, poly(vinylidene fluoride) (PVDF) and poly(butylene succinate) (PBS) polymers were used as nanofiber polymer materials. For PVDF and PBS nanofiber ACF, conductive particles of diameter 3.5 μm were incorporated into nanofibers by electrospinning. In <span class="hlt">ultra</span>-fine-pitch chip-on-glass assembly, insulation was significantly improved by using nanofiber ACF, because nanofibers inside the ACF suppressed the mobility of conductive particles, preventing them from flowing out during the bonding process. Capture of conductive particles was increased from 31% (conventional ACF) to 65%, and <span class="hlt">stable</span> electrical properties and reliability were achieved by use of nanofiber ACF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873705','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873705"><span>Power <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gitsevich, Aleksandr</p> <p>2001-01-01</p> <p>An <span class="hlt">oscillator</span> includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an <span class="hlt">oscillating</span> condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the <span class="hlt">oscillator</span> is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the <span class="hlt">oscillator</span> to a plurality of tuning states of the lamp.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28652000','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28652000"><span>Modeling coexistence of <span class="hlt">oscillation</span> and Delta/Notch-mediated lateral inhibition in pancreas development and neurogenesis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tiedemann, Hendrik B; Schneltzer, Elida; Beckers, Johannes; Przemeck, Gerhard K H; Hrabě de Angelis, Martin</p> <p>2017-10-07</p> <p>During pancreas development, Neurog3 positive endocrine progenitors are specified by Delta/Notch (D/N) mediated lateral inhibition in the growing ducts. During neurogenesis, genes that determine the transition from the proneural state to neuronal or glial lineages are <span class="hlt">oscillating</span> before their expression is sustained. Although the basic gene regulatory network is very similar, cycling gene expression in pancreatic development was not investigated yet, and previous simulations of lateral inhibition in pancreas development excluded by design the possibility of <span class="hlt">oscillations</span>. To explore this possibility, we developed a dynamic model of a growing duct that results in an oscillatory phase before the determination of endocrine progenitors by lateral inhibition. The basic network (D/N + Hes1 + Neurog3) shows scattered, <span class="hlt">stable</span> Neurog3 expression after displaying transient expression. Furthermore, we included the Hes1 negative feedback as previously discussed in neurogenesis and show the consequences for Neurog3 expression in pancreatic duct development. Interestingly, a weakened HES1 action on the Hes1 promoter allows the coexistence of <span class="hlt">stable</span> patterning and <span class="hlt">oscillations</span>. In conclusion, cycling gene expression and lateral inhibition are not mutually exclusive. In this way, we argue for a unified mode of D/N mediated lateral inhibition in neurogenic and pancreatic progenitor specification. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9760A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9760A"><span>First Rosetta Radio Science Bistatic Radar Observations of 67P/Churyumov-Gerasimenko</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andert, Thomas P.; Remus, Stefan; Simpson, Richard A.; Pätzold, Martin; Asmar, Sami W.; Kahan, Daniel S.; Bird, Mike K.; Häusler, Bernd; Tellmann, Silvia</p> <p>2015-04-01</p> <p>The Rosetta spacecraft was successfully inserted on 6th August 2014 into orbit around comet 67P/Churyumov-Gerasimenko. In September Rosetta was placed into bound orbits with an initial distance of 30 km and a decreasing distance until the end October. After lander delivery, bound orbits were maintained again at 20 km and 30 km. One of the objectives of the Rosetta Radio Science Investigations (RSI) is to address the dielectric properties, small-scale roughness, and rotational state of the nucleus of the comet, which can be determined by means of a surface scattering experiment, also known as Bistatic Radar. The radio subsystem transmitter located on board the Rosetta spacecraft beams right circularly polarized radio signals at two wavelengths -3.6 cm (X-Band) and 13 cm (S-Band) - toward the nucleus surface. Part of the impinging radiation is then scattered toward a receiver at a ground station on Earth and recorded. On September 29th, 2014 the first Bistatic Radar experiment ever at a comet was successfully conducted. The distance between 67P/Churyumov-Gerasimenko and Rosetta was 20 km and both right circularly polarized (RCP) and left circularly polarized (LCP) reflected signals from the comet's surface in X-Band were detected during the experiment at the Goldstone complex of the NASA Deep Space Network. The <span class="hlt">ultra-stable</span> <span class="hlt">oscillator</span> (<span class="hlt">USO</span>) on board Rosetta served during the experiment as a very <span class="hlt">stable</span> reference frequency source. The direct and reflected signal were separated during the experiment by only a fraction of 1 Hz. The extreme stability of the <span class="hlt">USO</span> allowed a detection and separation of the weak signals even on the required long integration times. Five additional Bistatic Radar experiments were conducted successfully between mid-October and mid-December 2014 with the 70-m DSN ground stations in Goldstone and Canberra at different distances to the comet (10 km, 20 km and 30 km) and reflected signals were observed in each case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/40203324-stochastic-dynamics-two-dimensional-oscillator-near-saddle-node-bifurcation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/40203324-stochastic-dynamics-two-dimensional-oscillator-near-saddle-node-bifurcation"><span>Stochastic dynamics in a two-dimensional <span class="hlt">oscillator</span> near a saddle-node bifurcation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Inchiosa, M. E.; In, V.; Bulsara, A. R.</p> <p></p> <p>We study the <span class="hlt">oscillator</span> equations describing a particular class of nonlinear amplifier, exemplified in this work by a two-junction superconducting quantum interference device. This class of dynamic system is described by a potential energy function that can admit minima (corresponding to <span class="hlt">stable</span> solutions of the dynamic equations), or {open_quotes}running states{close_quotes} wherein the system is biased so that the potential minima disappear and the solutions display spontaneous <span class="hlt">oscillations</span>. Just beyond the onset of the spontaneous <span class="hlt">oscillations</span>, the system is known to show significantly enhanced sensitivity to very weak magnetic signals. The global phase space structure allows us to apply a centermore » manifold technique to approximate analytically the oscillatory behavior just past the (saddle-node) bifurcation and compute the <span class="hlt">oscillation</span> period, which obeys standard scaling laws. In this regime, the dynamics can be represented by an {open_quotes}integrate-fire{close_quotes} model drawn from the computational neuroscience repertoire; in fact, we obtain an {open_quotes}interspike interval{close_quotes} probability density function and an associated power spectral density (computed via Renewal theory) that agree very well with the results obtained via numerical simulations. Notably, driving the system with one or more time sinusoids produces a noise-lowering injection locking effect and/or heterodyning.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3781891','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3781891"><span>Analysis of <span class="hlt">ultra</span>-triathlon performances</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lepers, Romuald; Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas</p> <p>2011-01-01</p> <p>Despite increased interest in <span class="hlt">ultra</span>-endurance events, little research has examined <span class="hlt">ultra</span>-triathlon performance. The aims of this study were: (i) to compare swimming, cycling, running, and overall performances in three <span class="hlt">ultra</span>-distance triathlons, double Ironman distance triathlon (2IMT) (7.6 km swimming, 360 km cycling, and 84.4 km running), triple Ironman distance triathlon (3IMT) (11.4 km, 540 km, and 126.6 km), and deca Ironman distance triathlon (10IMT) (38 km, 1800 km, and 420 km) and (ii) to examine the relationships between the 2IMT, 3IMT, and 10IMT performances to create predicted equations of the 10IMT performances. Race results from 1985 through 2009 were examined to identify triathletes who performed the three considered <span class="hlt">ultra</span>-distances. In total, 73 triathletes (68 men and 5 women) were identified. The contribution of swimming to overall <span class="hlt">ultra</span>-triathlon performance was lower than for cycling and running. Running performance was more important to overall performance for 2IMT and 3IMT compared with 10IMT The 2IMT and 3IMT performances were significantly correlated with 10IMT performances for swimming and cycling, but not for running. 10IMT total time performance might be predicted by the following equation: 10IMT race time (minutes) = 5885 + 3.69 × 3IMT race time (minutes). This analysis of human performance during <span class="hlt">ultra</span>-distance triathlons represents a unique data set in the field of <span class="hlt">ultra</span>-endurance events. Additional studies are required to determine the physiological and psychological factors associated with <span class="hlt">ultra</span>-triathlon performance. PMID:24198579</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22280520-micromagnetic-study-auto-oscillation-modes-spin-hall-nano-oscillators','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22280520-micromagnetic-study-auto-oscillation-modes-spin-hall-nano-oscillators"><span>Micromagnetic study of auto-<span class="hlt">oscillation</span> modes in spin-Hall nano-<span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ulrichs, H., E-mail: henning.ulrichs@uni-muenster.de; Demidov, V. E.; Demokritov, S. O.</p> <p>2014-01-27</p> <p>We present a numerical study of magnetization dynamics in a recently introduced spin torque nano-<span class="hlt">oscillator</span>, whose operational principle relies on the spin-Hall effect—spin-Hall nano-<span class="hlt">oscillators</span>. Our numerical results show good agreement with the experimentally observed behaviors and provide detailed information about the features of the primary auto-<span class="hlt">oscillation</span> mode observed in the experiments. They also clarify the physical nature of the secondary auto-<span class="hlt">oscillation</span> mode, which was experimentally observed under certain conditions only.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29167515','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29167515"><span>Symmetry breaking, Josephson <span class="hlt">oscillation</span> and self-trapping in a self-bound three-dimensional quantum ball.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Adhikari, S K</p> <p>2017-11-22</p> <p>We study spontaneous symmetry breaking (SSB), Josephson <span class="hlt">oscillation</span>, and self-trapping in a <span class="hlt">stable</span>, mobile, three-dimensional matter-wave spherical quantum ball self-bound by attractive two-body and repulsive three-body interactions. The SSB is realized by a parity-symmetric (a) one-dimensional (1D) double-well potential or (b) a 1D Gaussian potential, both along the z axis and no potential along the x and y axes. In the presence of each of these potentials, the symmetric ground state dynamically evolves into a doubly-degenerate SSB ground state. If the SSB ground state in the double well, predominantly located in the first well (z > 0), is given a small displacement, the quantum ball <span class="hlt">oscillates</span> with a self-trapping in the first well. For a medium displacement one encounters an asymmetric Josephson <span class="hlt">oscillation</span>. The asymmetric <span class="hlt">oscillation</span> is a consequence of SSB. The study is performed by a variational and a numerical solution of a non-linear mean-field model with 1D parity-symmetric perturbations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...590A.120K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...590A.120K"><span>Transverse <span class="hlt">oscillations</span> and stability of prominences in a magnetic field dip</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolotkov, D. Y.; Nisticò, G.; Nakariakov, V. M.</p> <p>2016-05-01</p> <p>Aims: We developed an analytical model of the global transverse <span class="hlt">oscillations</span> and mechanical stability of a quiescent prominence in the magnetised environment with a magnetic field dip that accounts for the mirror current effect. Methods: The model is based on the interaction of line currents through the Lorentz force. Within this concept the prominence is treated as a straight current-carrying wire, and the magnetic dip is provided by two photospheric current sources. Results: Properties of both vertical and horizontal <span class="hlt">oscillations</span> are determined by the value of the prominence current, its density and height above the photosphere, and the parameters of the magnetic dip. The prominence can be <span class="hlt">stable</span> in both horizontal and vertical directions simultaneously when the prominence current dominates in the system and its height is less than the half-distance between the photospheric sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060046119','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060046119"><span><span class="hlt">Oscillation</span> Amplitude Growth for a Decelerating Object with Constant Pitch Damping</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schoenenberger, Mark; Queen, Eric M.; Litton, Daniel</p> <p>2006-01-01</p> <p>The equations governing the deceleration and <span class="hlt">oscillation</span> of a blunt body moving along a planar trajectory are re-expressed in the form of the Euler-Cauchy equation. An analytic solution of this equation describes the <span class="hlt">oscillation</span> amplitude growth and frequency dilation with time for a statically <span class="hlt">stable</span> decelerating body with constant pitch damping. The <span class="hlt">oscillation</span> histories for several constant pitch damping values, predicted by the solution of the Euler-Cauchy equation are compared to POST six degree-of-freedom (6-DoF) trajectory simulations. The simulations use simplified aerodynamic coefficients matching the Euler-Cauchy approximations. Agreement between the model predictions and simulation results are excellent. Euler-Cauchy curves are also fit through nonlinear 6-DoF simulations and ballistic range data to identify static stability and pitch damping coefficients. The model os shown to closely fit through the data points and capture the behavior of the blunt body observed in simulation and experiment. The extracted coefficients are in reasonable agreement with higher fidelity, nonlinear parameter identification results. Finally, a nondimensional version of the Euler-Cauchy equation is presented and shown to be a simple and effective tool for designing dynamically scaled experiments for decelerating blunt capsule flight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JMiMi..15.1369W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JMiMi..15.1369W"><span>Droplet-based micro <span class="hlt">oscillating</span>-flow PCR chip</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Wei; Li, Zhi-Xin; Luo, Rong; Lü, Shu-Hai; Xu, Ai-Dong; Yang, Yong-Jun</p> <p>2005-08-01</p> <p>Polymerase chain reactions (PCR), thermally activated chemical reactions which are widely used for nucleic acid amplification, have recently received much attention in microelectromechanical systems and micro total analysis systems because a wide variety of DNA/RNA molecules can be enriched by PCR for further analyses. In the present work, a droplet-based micro <span class="hlt">oscillating</span>-flow PCR chip was designed and fabricated by the silicon microfabrication technique. Three different temperature zones, which were <span class="hlt">stable</span> at denaturation, extension and annealing temperatures and isolated from each other by a thin-wall linkage, were integrated with a single, simple and straight microchannel to form the chip's basic functional structure. The PCR mixture was injected into the chip as a single droplet and flowed through the three temperature zones in the main microchannel in an <span class="hlt">oscillating</span> manner to achieve the temperature maintenance and transitions. The chip's thermal performance was theoretically analyzed and numerically simulated. The results indicated that the time needed for the temperature of the droplet to change to the target value is less than 1 s, and the root mean square error of temperature is less than 0.2 °C. A droplet of 1 µl PCR mixture with standard HPV (Human Papilloma Virus)-DNA sample inside was amplified by the present chip and the results were analyzed by slab gel electrophoresis with separation of DNA markers in parallel. The electrophoresis results demonstrated that the micro <span class="hlt">oscillating</span>-flow PCR chip successfully amplified the HPV-DNA, with a processing time of about 15 min which is significantly reduced compared to that for the conventional PCR instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24977210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24977210"><span>Comparative study of popular objective functions for damping power system <span class="hlt">oscillations</span> in multimachine system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Islam, Naz Niamul; Hannan, M A; Shareef, Hussain; Mohamed, Azah; Salam, M A</p> <p>2014-01-01</p> <p>Power <span class="hlt">oscillation</span> damping controller is designed in linearized model with heuristic optimization techniques. Selection of the objective function is very crucial for damping controller design by optimization algorithms. In this research, comparative analysis has been carried out to evaluate the effectiveness of popular objective functions used in power system <span class="hlt">oscillation</span> damping. Two-stage lead-lag damping controller by means of power system stabilizers is optimized using differential search algorithm for different objective functions. Linearized model simulations are performed to compare the dominant mode's performance and then the nonlinear model is continued to evaluate the damping performance over power system <span class="hlt">oscillations</span>. All the simulations are conducted in two-area four-machine power system to bring a detailed analysis. Investigated results proved that multiobjective D-shaped function is an effective objective function in terms of moving unstable and lightly damped electromechanical modes into <span class="hlt">stable</span> region. Thus, D-shape function ultimately improves overall system damping and concurrently enhances power system reliability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AIPC..780..499D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AIPC..780..499D"><span><span class="hlt">Oscillator</span> Noise Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demir, Alper</p> <p>2005-08-01</p> <p><span class="hlt">Oscillators</span> are key components of many kinds of systems, particularly electronic and opto-electronic systems. Undesired perturbations, i.e. noise, that exist in practical systems adversely affect the spectral and timing properties of the signals generated by <span class="hlt">oscillators</span> resulting in phase noise and timing jitter. These are key performance limiting factors, being major contributors to bit-error-rate (BER) of RF and optical communication systems, and creating synchronization problems in clocked and sampled-data electronic systems. In noise analysis for <span class="hlt">oscillators</span>, the key is figuring out how the various disturbances and noise sources in the <span class="hlt">oscillator</span> end up as phase fluctuations. In doing so, one first computes transfer functions from the noise sources to the <span class="hlt">oscillator</span> phase, or the sensitivity of the <span class="hlt">oscillator</span> phase to these noise sources. In this paper, we first provide a discussion explaining the origins and the proper definition of this transfer or sensitivity function, followed by a critical review of the various numerical techniques for its computation that have been proposed by various authors over the past fifteen years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740020367','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740020367"><span>A finite difference method for the solution of the transonic flow around harmonically <span class="hlt">oscillating</span> wings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ehlers, E. F.</p> <p>1974-01-01</p> <p>A finite difference method for the solution of the transonic flow about a harmonically <span class="hlt">oscillating</span> wing is presented. The partial differential equation for the unsteady transonic flow was linearized by dividing the flow into separate steady and unsteady perturbation velocity potentials and by assuming small amplitudes of harmonic <span class="hlt">oscillation</span>. The resulting linear differential equation is of mixed type, being elliptic or hyperbolic whereever the steady flow equation is elliptic or hyperbolic. Central differences were used for all derivatives except at supersonic points where backward differencing was used for the streamwise direction. Detailed formulas and procedures are described in sufficient detail for programming on high speed computers. To test the method, the problem of the <span class="hlt">oscillating</span> flap on a NACA 64A006 airfoil was programmed. The numerical procedure was found to be <span class="hlt">stable</span> and convergent even in regions of local supersonic flow with shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27349706','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27349706"><span>Consumers' conceptualization of <span class="hlt">ultra</span>-processed foods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ares, Gastón; Vidal, Leticia; Allegue, Gimena; Giménez, Ana; Bandeira, Elisa; Moratorio, Ximena; Molina, Verónika; Curutchet, María Rosa</p> <p>2016-10-01</p> <p>Consumption of <span class="hlt">ultra</span>-processed foods has been associated with low diet quality, obesity and other non-communicable diseases. This situation makes it necessary to develop educational campaigns to discourage consumers from substituting meals based on unprocessed or minimally processed foods by <span class="hlt">ultra</span>-processed foods. In this context, the aim of the present work was to investigate how consumers conceptualize the term <span class="hlt">ultra</span>-processed foods and to evaluate if the foods they perceive as <span class="hlt">ultra</span>-processed are in concordance with the products included in the NOVA classification system. An online study was carried out with 2381 participants. They were asked to explain what they understood by <span class="hlt">ultra</span>-processed foods and to list foods that can be considered <span class="hlt">ultra</span>-processed. Responses were analysed using inductive coding. The great majority of the participants was able to provide an explanation of what <span class="hlt">ultra</span>-processed foods are, which was similar to the definition described in the literature. Most of the participants described <span class="hlt">ultra</span>-processed foods as highly processed products that usually contain additives and other artificial ingredients, stressing that they have low nutritional quality and are unhealthful. The most relevant products for consumers' conceptualization of the term were in agreement with the NOVA classification system and included processed meats, soft drinks, snacks, burgers, powdered and packaged soups and noodles. However, some of the participants perceived processed foods, culinary ingredients and even some minimally processed foods as <span class="hlt">ultra</span>-processed. This suggests that in order to accurately convey their message, educational campaigns aimed at discouraging consumers from consuming <span class="hlt">ultra</span>-processed foods should include a clear definition of the term and describe some of their specific characteristics, such as the type of ingredients included in their formulation and their nutritional composition. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5093558','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5093558"><span><span class="hlt">Ultra</span>-Smooth, Fully Solution-Processed Large-Area Transparent Conducting Electrodes for Organic Devices</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jin, Won-Yong; Ginting, Riski Titian; Ko, Keum-Jin; Kang, Jae-Wook</p> <p>2016-01-01</p> <p>A novel approach for the fabrication of <span class="hlt">ultra</span>-smooth and highly bendable substrates consisting of metal grid-conducting polymers that are fully embedded into transparent substrates (ME-TCEs) was successfully demonstrated. The fully printed ME-TCEs exhibited <span class="hlt">ultra</span>-smooth surfaces (surface roughness ~1.0 nm), were highly transparent (~90% transmittance at a wavelength of 550 nm), highly conductive (sheet resistance ~4 Ω ◻−1), and relatively <span class="hlt">stable</span> under ambient air (retaining ~96% initial resistance up to 30 days). The ME-TCE substrates were used to fabricate flexible organic solar cells and organic light-emitting diodes exhibiting devices efficiencies comparable to devices fabricated on ITO/glass substrates. Additionally, the flexibility of the organic devices did not degrade their performance even after being bent to a bending radius of ~1 mm. Our findings suggest that ME-TCEs are a promising alternative to indium tin oxide and show potential for application toward large-area optoelectronic devices via fully printing processes. PMID:27808221</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...636475J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...636475J"><span><span class="hlt">Ultra</span>-Smooth, Fully Solution-Processed Large-Area Transparent Conducting Electrodes for Organic Devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Won-Yong; Ginting, Riski Titian; Ko, Keum-Jin; Kang, Jae-Wook</p> <p>2016-11-01</p> <p>A novel approach for the fabrication of <span class="hlt">ultra</span>-smooth and highly bendable substrates consisting of metal grid-conducting polymers that are fully embedded into transparent substrates (ME-TCEs) was successfully demonstrated. The fully printed ME-TCEs exhibited <span class="hlt">ultra</span>-smooth surfaces (surface roughness ~1.0 nm), were highly transparent (~90% transmittance at a wavelength of 550 nm), highly conductive (sheet resistance ~4 Ω ◻-1), and relatively <span class="hlt">stable</span> under ambient air (retaining ~96% initial resistance up to 30 days). The ME-TCE substrates were used to fabricate flexible organic solar cells and organic light-emitting diodes exhibiting devices efficiencies comparable to devices fabricated on ITO/glass substrates. Additionally, the flexibility of the organic devices did not degrade their performance even after being bent to a bending radius of ~1 mm. Our findings suggest that ME-TCEs are a promising alternative to indium tin oxide and show potential for application toward large-area optoelectronic devices via fully printing processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27808221','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27808221"><span><span class="hlt">Ultra</span>-Smooth, Fully Solution-Processed Large-Area Transparent Conducting Electrodes for Organic Devices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Won-Yong; Ginting, Riski Titian; Ko, Keum-Jin; Kang, Jae-Wook</p> <p>2016-11-03</p> <p>A novel approach for the fabrication of <span class="hlt">ultra</span>-smooth and highly bendable substrates consisting of metal grid-conducting polymers that are fully embedded into transparent substrates (ME-TCEs) was successfully demonstrated. The fully printed ME-TCEs exhibited <span class="hlt">ultra</span>-smooth surfaces (surface roughness ~1.0 nm), were highly transparent (~90% transmittance at a wavelength of 550 nm), highly conductive (sheet resistance ~4 Ω ◻ -1 ), and relatively <span class="hlt">stable</span> under ambient air (retaining ~96% initial resistance up to 30 days). The ME-TCE substrates were used to fabricate flexible organic solar cells and organic light-emitting diodes exhibiting devices efficiencies comparable to devices fabricated on ITO/glass substrates. Additionally, the flexibility of the organic devices did not degrade their performance even after being bent to a bending radius of ~1 mm. Our findings suggest that ME-TCEs are a promising alternative to indium tin oxide and show potential for application toward large-area optoelectronic devices via fully printing processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25362426','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25362426"><span><span class="hlt">Ultra</span>-low frequency vertical vibration isolator based on LaCoste spring linkage.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, G; Hu, H; Wu, K; Wang, G; Wang, L J</p> <p>2014-10-01</p> <p>For the applications in precision measurement such as absolute gravimeter, we have designed and built an <span class="hlt">ultra</span>-low frequency vertical vibration isolator based on LaCoste spring linkage. In the system, an arm with test mass is suspended by a mechanical extension spring, and one end of the arm is connected to the frame with flexible pivots. The displacement of the arm is detected by an optical reflection method. With the displacement signal, a feedback control force is exerted on the arm to keep it at the balance position. This method can also correct the systematic drift caused by temperature change. In order to study the vibration isolation performance of the system, we analyze the dynamic characteristics of the spring linkage in the general case, and present key methods to adjust the natural <span class="hlt">oscillating</span> period of the system. With careful adjustment, the system can achieve a steady <span class="hlt">oscillation</span> with a natural period up to 32 s. This isolator has been tested based on the T-1 absolute gravimeter. A statistical uncertainty of 2 μGal has been achieved within a typical 12 h measurement. The experimental results verify that the isolator has significant vibration isolation performance, and it is very suitable for applications in high precision absolute gravity measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RScI...85j4502L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RScI...85j4502L"><span><span class="hlt">Ultra</span>-low frequency vertical vibration isolator based on LaCoste spring linkage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, G.; Hu, H.; Wu, K.; Wang, G.; Wang, L. J.</p> <p>2014-10-01</p> <p>For the applications in precision measurement such as absolute gravimeter, we have designed and built an <span class="hlt">ultra</span>-low frequency vertical vibration isolator based on LaCoste spring linkage. In the system, an arm with test mass is suspended by a mechanical extension spring, and one end of the arm is connected to the frame with flexible pivots. The displacement of the arm is detected by an optical reflection method. With the displacement signal, a feedback control force is exerted on the arm to keep it at the balance position. This method can also correct the systematic drift caused by temperature change. In order to study the vibration isolation performance of the system, we analyze the dynamic characteristics of the spring linkage in the general case, and present key methods to adjust the natural <span class="hlt">oscillating</span> period of the system. With careful adjustment, the system can achieve a steady <span class="hlt">oscillation</span> with a natural period up to 32 s. This isolator has been tested based on the T-1 absolute gravimeter. A statistical uncertainty of 2 μGal has been achieved within a typical 12 h measurement. The experimental results verify that the isolator has significant vibration isolation performance, and it is very suitable for applications in high precision absolute gravity measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150016313','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150016313"><span>Evaluation of Start Transient <span class="hlt">Oscillations</span> with the J-2X Engine Gas Generator Assembly</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hulka, J. R.; Morgan, C. J.; Casiano, M. J.</p> <p>2015-01-01</p> <p>During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure <span class="hlt">oscillations</span> and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These <span class="hlt">oscillations</span> appeared whether the steady-state conditions exhibited <span class="hlt">stable</span> behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of <span class="hlt">oscillations</span> occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the <span class="hlt">oscillations</span> were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency <span class="hlt">oscillation</span> usually related to the second longitudinal acoustic mode and the later and lower frequency <span class="hlt">oscillation</span> usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient <span class="hlt">oscillations</span> are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate <span class="hlt">oscillations</span> and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RCD....22..210J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RCD....22..210J"><span>Autonomous strange nonchaotic <span class="hlt">oscillations</span> in a system of mechanical rotators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jalnine, Alexey Yu.; Kuznetsov, Sergey P.</p> <p>2017-05-01</p> <p>We investigate strange nonchaotic self-<span class="hlt">oscillations</span> in a dissipative system consisting of three mechanical rotators driven by a constant torque applied to one of them. The external driving is nonoscillatory; the incommensurable frequency ratio in vibrational-rotational dynamics arises due to an irrational ratio of diameters of the rotating elements involved. It is shown that, when losing <span class="hlt">stable</span> equilibrium, the system can demonstrate two- or three-frequency quasi-periodic, chaotic and strange nonchaotic self-<span class="hlt">oscillations</span>. The conclusions of the work are confirmed by numerical calculations of Lyapunov exponents, fractal dimensions, spectral analysis, and by special methods of detection of a strange nonchaotic attractor (SNA): phase sensitivity and analysis using rational approximation for the frequency ratio. In particular, SNA possesses a zero value of the largest Lyapunov exponent (and negative values of the other exponents), a capacitive dimension close to 2 and a singular continuous power spectrum. In general, the results of this work shed a new light on the occurrence of strange nonchaotic dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29857671','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29857671"><span>Tuning the synchronization of a network of weakly coupled self-<span class="hlt">oscillating</span> gels via capacitors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fang, Yan; Yashin, Victor V; Dickerson, Samuel J; Balazs, Anna C</p> <p>2018-05-01</p> <p>We consider a network of coupled <span class="hlt">oscillating</span> units, where each unit comprises a self-<span class="hlt">oscillating</span> polymer gel undergoing the Belousov-Zhabotinsky (BZ) reaction and an overlaying piezoelectric (PZ) cantilever. Through chemo-mechano-electrical coupling, the <span class="hlt">oscillations</span> of the networked BZ-PZ units achieve in-phase or anti-phase synchronization, enabling, for example, the storage of information within the system. Herein, we develop numerical and computational models to show that the introduction of capacitors into the BZ-PZ system enhances the dynamical behavior of the <span class="hlt">oscillating</span> network by yielding additional <span class="hlt">stable</span> synchronization modes. We specifically show that the capacitors lead to a redistribution of charge in the system and alteration of the force that the PZ cantilevers apply to the underlying gel. Hence, the capacitors modify the strength of the coupling between the <span class="hlt">oscillators</span> in the network. We utilize a linear stability analysis to determine the phase behavior of BZ-PZ networks encompassing different capacitances, force polarities, and number of units and then verify our findings with numerical simulations. Thus, through analytical calculations and numerical simulations, we determine the impact of the capacitors on the existence of the synchronization modes, their stability, and the rate of synchronization within these complex dynamical systems. The findings from our study can be used to design robotic materials that harness the materials' intrinsic, responsive properties to perform such functions as sensing, actuation, and information storage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Chaos..28e3106F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Chaos..28e3106F"><span>Tuning the synchronization of a network of weakly coupled self-<span class="hlt">oscillating</span> gels via capacitors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fang, Yan; Yashin, Victor V.; Dickerson, Samuel J.; Balazs, Anna C.</p> <p>2018-05-01</p> <p>We consider a network of coupled <span class="hlt">oscillating</span> units, where each unit comprises a self-<span class="hlt">oscillating</span> polymer gel undergoing the Belousov-Zhabotinsky (BZ) reaction and an overlaying piezoelectric (PZ) cantilever. Through chemo-mechano-electrical coupling, the <span class="hlt">oscillations</span> of the networked BZ-PZ units achieve in-phase or anti-phase synchronization, enabling, for example, the storage of information within the system. Herein, we develop numerical and computational models to show that the introduction of capacitors into the BZ-PZ system enhances the dynamical behavior of the <span class="hlt">oscillating</span> network by yielding additional <span class="hlt">stable</span> synchronization modes. We specifically show that the capacitors lead to a redistribution of charge in the system and alteration of the force that the PZ cantilevers apply to the underlying gel. Hence, the capacitors modify the strength of the coupling between the <span class="hlt">oscillators</span> in the network. We utilize a linear stability analysis to determine the phase behavior of BZ-PZ networks encompassing different capacitances, force polarities, and number of units and then verify our findings with numerical simulations. Thus, through analytical calculations and numerical simulations, we determine the impact of the capacitors on the existence of the synchronization modes, their stability, and the rate of synchronization within these complex dynamical systems. The findings from our study can be used to design robotic materials that harness the materials' intrinsic, responsive properties to perform such functions as sensing, actuation, and information storage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA123373','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA123373"><span>Automatic <span class="hlt">Oscillating</span> Turret.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1981-03-01</p> <p>Final Report: February 1978 ZAUTOMATIC <span class="hlt">OSCILLATING</span> TURRET SYSTEM September 1980 * 6. PERFORMING 01G. REPORT NUMBER .J7. AUTHOR(S) S. CONTRACT OR GRANT...o....e.... *24 APPENDIX P-4 <span class="hlt">OSCILLATING</span> BUMPER TURRET ...................... 25 A. DESCRIPTION 1. Turret Controls ...Other criteria requirements were: 1. Turret controls inside cab. 2. Automatic <span class="hlt">oscillation</span> with fixed elevation to range from 20* below the horizontal to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28147493','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28147493"><span>Effect of parameter mismatch on the dynamics of strongly coupled self sustained <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chakrabarty, Nilaj; Jain, Aditya; Lal, Nijil; Das Gupta, Kantimay; Parmananda, Punit</p> <p>2017-01-01</p> <p>In this paper, we present an experimental setup and an associated mathematical model to study the synchronization of two self-sustained, strongly coupled, mechanical <span class="hlt">oscillators</span> (metronomes). The effects of a small detuning in the internal parameters, namely, damping and frequency, have been studied. Our experimental system is a pair of spring wound mechanical metronomes; coupled by placing them on a common base, free to move along a horizontal direction. We designed a photodiode array based non-contact, non-magnetic position detection system driven by a microcontroller to record the instantaneous angular displacement of each <span class="hlt">oscillator</span> and the small linear displacement of the base, coupling the two. In our system, the mass of the <span class="hlt">oscillating</span> pendula forms a significant fraction of the total mass of the system, leading to strong coupling of the <span class="hlt">oscillators</span>. We modified the internal mechanism of the spring-wound "clockwork" slightly, such that the natural frequency and the internal damping could be independently tuned. <span class="hlt">Stable</span> synchronized and anti-synchronized states were observed as the difference in the parameters was varied in the experiments. The simulation results showed a rapid increase in the phase difference between the two <span class="hlt">oscillators</span> beyond a certain threshold of parameter mismatch. Our simple model of the escapement mechanism did not reproduce a complete 180° out of phase state. However, the numerical simulations show that increased mismatch in parameters leads to a synchronized state with a large phase difference.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22402553-partial-synchronization-networks-non-linearly-coupled-oscillators-deserter-hubs-model','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22402553-partial-synchronization-networks-non-linearly-coupled-oscillators-deserter-hubs-model"><span>Partial synchronization in networks of non-linearly coupled <span class="hlt">oscillators</span>: The Deserter Hubs Model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Freitas, Celso, E-mail: cbnfreitas@gmail.com; Macau, Elbert, E-mail: elbert.macau@inpe.br; Pikovsky, Arkady, E-mail: pikovsky@uni-potsdam.de</p> <p>2015-04-15</p> <p>We study the Deserter Hubs Model: a Kuramoto-like model of coupled identical phase <span class="hlt">oscillators</span> on a network, where attractive and repulsive couplings are balanced dynamically due to nonlinearity of interactions. Under weak force, an <span class="hlt">oscillator</span> tends to follow the phase of its neighbors, but if an <span class="hlt">oscillator</span> is compelled to follow its peers by a sufficient large number of cohesive neighbors, then it actually starts to act in the opposite manner, i.e., in anti-phase with the majority. Analytic results yield that if the repulsion parameter is small enough in comparison with the degree of the maximum hub, then the fullmore » synchronization state is locally <span class="hlt">stable</span>. Numerical experiments are performed to explore the model beyond this threshold, where the overall cohesion is lost. We report in detail partially synchronous dynamical regimes, like stationary phase-locking, multistability, periodic and chaotic states. Via statistical analysis of different network organizations like tree, scale-free, and random ones, we found a measure allowing one to predict relative abundance of partially synchronous stationary states in comparison to time-dependent ones.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19813091','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19813091"><span>A servo-controlled canine model of <span class="hlt">stable</span> severe ischemic left ventricular failure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wagner, Richard L; Hood, William B; Howland, Peter A</p> <p>2009-12-01</p> <p>Reversible left ventricular failure was produced in conscious dogs by compromise of the coronary circulation. In animals with prior left anterior descending coronary artery occlusion, mean left atrial pressure (LAP) was incorporated into an automatic feedback control system used to inflate a balloon cuff on the circumflex (Cfx) coronary artery. The system could produce <span class="hlt">stable</span> increases in LAP to 15-20 mm Hg. The dominating system transfer function was the ratio of LAP to balloon volume (BV), which was characterized by a fixed delay (5 s), with LAP/BV = (8e(-jomegatau ))/(0.02 + jomega). The system was stabilized by a phase lead network to reduce <span class="hlt">oscillations</span> of LAP. A total of seven experiments were conducted in three dogs, and testing of inotropic agents was possible in three experiments under <span class="hlt">stable</span> conditions with the pump off after an hour or more of operation. Problems encountered were 0.003-0.008 Hz <span class="hlt">oscillations</span> in LAP in three experiments, which could usually be controlled by reducing the system gain. Late stage ventricular fibrillation occurred in all three animals, but defibrillation was easily accomplished after deflating the Cfx balloon. This system produces reversible left ventricular failure solely due to ischemia, thus closely simulating clinical heart failure due to coronary insufficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EJPh...31..433D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EJPh...31..433D"><span>Magnetically coupled magnet-spring <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donoso, G.; Ladera, C. L.; Martín, P.</p> <p>2010-05-01</p> <p>A system of two magnets hung from two vertical springs and <span class="hlt">oscillating</span> in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled <span class="hlt">oscillators</span>. The electromagnetically coupled <span class="hlt">oscillations</span> of these <span class="hlt">oscillators</span> are experimentally and theoretically studied. Its coupling is electromagnetic instead of mechanical, and easily adjustable by the experimenter. The coupling of this new coupled <span class="hlt">oscillator</span> system is determined by the currents that the magnets induce in two coils connected in series, one to each magnet. It is an interesting case of mechanical <span class="hlt">oscillators</span> with field-driven coupling, instead of mechanical coupling. Moreover, it is both a coupled and a damped <span class="hlt">oscillating</span> system that lends itself to a detailed study and presentation of many properties and phenomena of such a system of <span class="hlt">oscillators</span>. A set of experiments that validates the theoretical model of the <span class="hlt">oscillators</span> is presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001fmce.conf...37M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001fmce.conf...37M"><span>Ultrastable Cryogenic Microwave <span class="hlt">Oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mann, Anthony G.</p> <p></p> <p>Ultrastable cryogenic microwave <span class="hlt">oscillators</span> are secondary frequency standards in the microwave domain. The best of these <span class="hlt">oscillators</span> have demonstrated a short term frequency stability in the range 10-14 to a few times 10-16. The main application for these <span class="hlt">oscillators</span> is as flywheel <span class="hlt">oscillators</span> for the next generation of passive atomic frequency standards, and as local <span class="hlt">oscillators</span> in space telemetry ground stations to clean up the transmitter close in phase noise. Fractional frequency stabilities of passive atomic frequency standards are now approaching <!- MATH ensuremath{3 x 10(-14) /sqrt{tau}} -> 3 x10^-14 /τ where τ is the measurement time, limited only by the number of atoms that are being interrogated. This requires an interrogation <span class="hlt">oscillator</span> whose short-term stability is of the order of 10-14 or better, which cannot be provided by present-day quartz technology. Ultrastable cryogenic microwave <span class="hlt">oscillators</span> are based on resonators which have very high electrical Q-factors. The resolution of the resonator's linewidth is typically limited by electronics noise to about 1ppm and hence Q-factors in excess of 108 are required. As these are only attained in superconducting cavities or sapphire resonators at low temperatures, use of liquid helium cooling is mandatory, which has so far restricted these <span class="hlt">oscillators</span> to the research or metrology laboratory. Recently, there has been an effort to dispense with the need for liquid helium and make compact flywheel <span class="hlt">oscillators</span> for the new generation of primary frequency standards. Work is under way to achieve this goal in space-borne and mobile liquid-nitrogen-cooled systems. The best cryogenic <span class="hlt">oscillators</span> developed to date are the ``whispering gallery'' (WG) mode sapphire resonator-<span class="hlt">oscillators</span> of NASA's Jet Propulsion Laboratory (JPL) and the University of Western Australia (UWA), as well as Stanford University's superconducting cavity stabilized <span class="hlt">oscillator</span> (SCSO). All of these <span class="hlt">oscillators</span> have demonstrated frequency</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23055390','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23055390"><span>Large enhancement of <span class="hlt">oscillating</span> chemiluminescence with [Ru(bpy)3 ](2+) -catalyzed Belousov-Zhabotinsky reaction in the presence of tri-n-propylamine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lan, Xiaolan; Zheng, Baozhan; Zhao, Yan; Yuan, Hongyan; Du, Juan; Xiao, Dan</p> <p>2013-01-01</p> <p><span class="hlt">Oscillating</span> chemiluminescence enhanced by the addition of tri-n-propylamine (TPrA) to the typical Belousov-Zhabotinsky (BZ) reaction system catalyzed by ruthenium(II)tris(2.2'-bipyridine)(Ru(bpy)3 (2+) ) was investigated using a luminometry method. The [Ru(bpy)3 ](2+) /TPrA system was first used as the catalyst for a BZ <span class="hlt">oscillator</span> in a closed system, which exhibited a shorter induction period, higher amplitude and much more <span class="hlt">stable</span> chemiluminescence (CL) <span class="hlt">oscillation</span>. The effects of various concentrations of TPrA, oxygen and nitrogen flow rate on the <span class="hlt">oscillating</span> behavior of this system were examined. In addition, the CL intensity of the [Ru(bpy)3 ](2+) /TPrA-BZ system was found to be inhibited by phenol, thus providing a way for use of the BZ system in the determination of phenolic compounds. Moreover, the possible mechanism of the <span class="hlt">oscillating</span> CL reaction catalyzed by [Ru(bpy)3 ](2+) /TPrA and the inhibition effects of oxygen and phenol on this <span class="hlt">oscillating</span> CL system were considered. Copyright © 2012 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.P44A..03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.P44A..03K"><span>Periodical <span class="hlt">oscillation</span> of zonal wind velocities at the cloud top of Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kouyama, T.; Imamura, T.; Nakamura, M.; Satoh, T.; Futaana, Y.</p> <p>2010-12-01</p> <p>Zonal wind velocity of Venus increases with height and reaches about 100 m s-1 at the cloud top level (~70km). The speed is approximately 60 times faster than the rotation speed of the solid body of Venus (~1.6 m s-1, at the equator) and this phenomenon is called a "super-rotation". From previous observations, it is known that the super-rotation changes on a long timescale. At the cloud top level, it was suggested that the super-rotation has a few years period <span class="hlt">oscillation</span> based on observations made by Pioneer Venus orbiter of USA from 1979 to 1985 (Del Genio et al.,1990). However, the period, the amplitude, the spatial structure and the mechanism of the long period <span class="hlt">oscillation</span> have not been understood well. Venus Express (VEX) of European Space Agency has been observing Venus since its orbital insertion in April 2006. Venus Monitoring Camera (VMC) onboard VEX has an <span class="hlt">ultra</span> violet (UV) filter (365 nm), and VMC has taken day-side cloud images at the cloud top level with this filter. Such images exhibit various cloud features made by unknown UV absorber in the atmosphere. For investigating the characteristics of long-timescale variations of the super-rotation, we analyzed zonal velocity fields derived from UV cloud images from May 2006 to January 2010 using a cloud tracking method. UV imaging of VMC is done when the spacecraft is in the ascending portion of its elongated polar orbit. Since the orbital plane is nearly fixed in the inertial space, the local time of VMC/UV observation changes with a periodicity of one Venus year. As a result, periods when VMC observation covered day-side areas of Venus, large enough for cloud trackings, are not continuous. For deriving wind velocities we were able to use cloud images taken in 280 orbits during this period. The derived zonal wind velocity from 10°S to 40°S latitude shows a prominent year-to-year variation, and the variation is well fitted by a periodical <span class="hlt">oscillation</span> with a period of about 260 Earth days, although not all</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22488575-oscillation-characteristics-zero-field-spin-transfer-oscillators-field-like-torque','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22488575-oscillation-characteristics-zero-field-spin-transfer-oscillators-field-like-torque"><span><span class="hlt">Oscillation</span> characteristics of zero-field spin transfer <span class="hlt">oscillators</span> with field-like torque</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Guo, Yuan-Yuan; Xue, Hai-Bin, E-mail: xuehaibin@tyut.edu.cn; Department of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024</p> <p>2015-05-15</p> <p>We theoretically investigate the influence of the field-like spin torque term on the <span class="hlt">oscillation</span> characteristics of spin transfer <span class="hlt">oscillators</span>, which are based on MgO magnetic tunnel junctions (MTJs) consisting of a perpendicular magnetized free layer and an in-plane magnetized pinned layer. It is demonstrated that the field-like torque has a strong impact on the steady-state precession current region and the <span class="hlt">oscillation</span> frequency. In particular, the steady-state precession can occur at zero applied magnetic field when the ratio between the field-like torque and the spin transfer torque takes up a negative value. In addition, the dependence of the <span class="hlt">oscillation</span> properties onmore » the junction sizes has also been analyzed. The results indicate that this compact structure of spin transfer <span class="hlt">oscillator</span> without the applied magnetic field is practicable under certain conditions, and it may be a promising configuration for the new generation of on-chip <span class="hlt">oscillators</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..114a2012C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..114a2012C"><span>Design of c-band telecontrol transmitter local <span class="hlt">oscillator</span> for UAV data link</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Hui; Qu, Yu; Song, Zuxun</p> <p>2018-01-01</p> <p>A C-band local <span class="hlt">oscillator</span> of an Unmanned Aerial Vehicle (UAV) data link radio frequency (RF) transmitter unit with high-stability, high-precision and lightweight was designed in this paper. Based on the highly integrated broadband phase-locked loop (PLL) chip HMC834LP6GE, the system performed fractional-N control by internal modules programming to achieve low phase noise and small frequency resolution. The simulation and testing methods were combined to optimize and select the loop filter parameters to ensure the high precision and stability of the frequency synthesis output. The theoretical analysis and engineering prototype measurement results showed that the local <span class="hlt">oscillator</span> had <span class="hlt">stable</span> output frequency, accurate frequency step, high spurious suppression and low phase noise, and met the design requirements. The proposed design idea and research method have theoretical guiding significance for engineering practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=permanent+AND+magnet&pg=2&id=EJ407497','ERIC'); return false;" href="https://eric.ed.gov/?q=permanent+AND+magnet&pg=2&id=EJ407497"><span><span class="hlt">Oscillating</span> Permanent Magnets.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Michaelis, M. M.; Haines, C. M.</p> <p>1989-01-01</p> <p>Describes several ways to partially levitate permanent magnets. Computes field line geometries and <span class="hlt">oscillation</span> frequencies. Provides several diagrams illustrating the mechanism of the <span class="hlt">oscillation</span>. (YP)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030106474&hterms=tesla&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtesla','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030106474&hterms=tesla&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtesla"><span>Developing Antimatter Containment Technology: Modeling Charged Particle <span class="hlt">Oscillations</span> in a Penning-Malmberg Trap</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chakrabarti, S.; Martin, J. J.; Pearson, J. B.; Lewis, R. A.</p> <p>2003-01-01</p> <p>The NASA MSFC Propulsion Research Center (PRC) is conducting a research activity examining the storage of low energy antiprotons. The High Performance Antiproton Trap (HiPAT) is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage confinement electrode system, and an <span class="hlt">ultra</span> high vacuum test section; designed with an ultimate goal of maintaining charged particles with a half-life of 18 days. Currently, this system is being experimentally evaluated using normal matter ions which are cheap to produce and relatively easy to handle and provide a good indication of overall trap behavior, with the exception of assessing annihilation losses. Computational particle-in-cell plasma modeling using the XOOPIC code is supplementing the experiments. Differing electrode voltage configurations are employed to contain charged particles, typically using flat, modified flat and harmonic potential wells. Ion cloud <span class="hlt">oscillation</span> frequencies are obtained experimentally by amplification of signals induced on the electrodes by the particle motions. XOOPIC simulations show that for given electrode voltage configurations, the calculated charged particle <span class="hlt">oscillation</span> frequencies are close to experimental measurements. As a two-dimensional axisymmetric code, XOOPIC cannot model azimuthal plasma variations, such as those induced by radio-frequency (RF) modulation of the central quadrupole electrode in experiments designed to enhance ion cloud containment. However, XOOPIC can model analytically varying electric potential boundary conditions and particle velocity initial conditions. Application of these conditions produces ion cloud axial and radial <span class="hlt">oscillation</span> frequency modes of interest in achieving the goal of optimizing HiPAT for reliable containment of antiprotons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BoLMe.166..269A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BoLMe.166..269A"><span>Gravity Waves and Wind-Farm Efficiency in Neutral and <span class="hlt">Stable</span> Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allaerts, Dries; Meyers, Johan</p> <p>2018-02-01</p> <p>We use large-eddy simulations (LES) to investigate the impact of <span class="hlt">stable</span> stratification on gravity-wave excitation and energy extraction in a large wind farm. To this end, the development of an equilibrium conventionally neutral boundary layer into a <span class="hlt">stable</span> boundary layer over a period of 8 h is considered, using two different cooling rates. We find that turbulence decay has considerable influence on the energy extraction at the beginning of the boundary-layer transition, but afterwards, energy extraction is dominated by geometrical and jet effects induced by an inertial <span class="hlt">oscillation</span>. It is further shown that the inertial <span class="hlt">oscillation</span> enhances gravity-wave excitation. By comparing LES results with a simple one-dimensional model, we show that this is related to an interplay between wind-farm drag, variations in the Froude number and the dispersive effects of vertically-propagating gravity waves. We further find that the pressure gradients induced by gravity waves lead to significant upstream flow deceleration, reducing the average turbine output compared to a turbine in isolated operation. This leads us to the definition of a non-local wind-farm efficiency, next to a more standard wind-farm wake efficiency, and we show that both can be of the same order of magnitude. Finally, an energy flux analysis is performed to further elucidate the effect of gravity waves on the flow in the wind farm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1349026','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1349026"><span><span class="hlt">Oscillation</span> Baselining and Analysis Tool</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p></p> <p></p> <p>PNNL developed a new tool for <span class="hlt">oscillation</span> analysis and baselining. This tool has been developed under a new DOE Grid Modernization Laboratory Consortium (GMLC) Project (GM0072 - “Suite of open-source applications and models for advanced synchrophasor analysis”) and it is based on the open platform for PMU analysis. The <span class="hlt">Oscillation</span> Baselining and Analysis Tool (OBAT) performs the <span class="hlt">oscillation</span> analysis and identifies modes of <span class="hlt">oscillations</span> (frequency, damping, energy, and shape). The tool also does <span class="hlt">oscillation</span> event baselining (fining correlation between <span class="hlt">oscillations</span> characteristics and system operating conditions).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012921','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012921"><span>Characterization of the Vectron PX-570 Crystal <span class="hlt">Oscillator</span> for Use in Harsh Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Li, Jacob; Patterson, Richard L.; Hammoud, Ahmad</p> <p>2012-01-01</p> <p>Computing hardware, data-acquisition systems, communications systems, and many electronic control systems require well-controlled timing signals for proper and accurate operation. These signals are, in most cases, provided by circuits that employ crystal <span class="hlt">oscillators</span> due to availability, cost, ease of operation, and accuracy. In some cases, the electronic systems are expected to survive and operate under harsh conditions that include exposure to extreme temperatures. These applications exist in terrestrial systems as well as in aerospace products. Well-logging, geothermal systems, and industrial process control are examples of ground-based applications, while distributed jet engine control in aircraft, space-based observatories (such as the James Webb Space Telescope), satellites, and lunar and planetary landers are typical environments where electronics are exposed to harsh operating conditions. To ensure these devices produce reliable results, the digital heartbeat from the <span class="hlt">oscillator</span> must deliver a <span class="hlt">stable</span> signal that is not affected by external temperature or other conditions. One such solution is a recently introduced commercial-off-the-shelf (COTS) <span class="hlt">oscillator</span>, the PX-570 series from Vectron International. The <span class="hlt">oscillator</span> was designed for high-temperature applications and as proof, the crystal <span class="hlt">oscillator</span> was subjected to a wide suite of tests to determine its ruggedness for operation in harsh environments. The tests performed by Vectron included electrical characterization under wide range of temperature, accelerated life test/aging, shock and vibration, internal moisture analysis, ESD threshold, and latch-up testing. The parametric evaluation was performed on the <span class="hlt">oscillator</span>'s frequency, output signal rise and fall times, duty cycle, and supply current over the temperature range of -125 C to +230 C. The evaluations also determined the effects of thermal cycling and the <span class="hlt">oscillator</span>'s re-start capability at extreme hot and cold temperatures. These thermal cycling</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012246','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012246"><span>MMIC Replacement for Gunn Diode <span class="hlt">Oscillators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crowe, Thomas W.; Porterfield, David</p> <p>2011-01-01</p> <p>An all-solid-state replacement for high-frequency Gunn diode <span class="hlt">oscillators</span> (GDOs) has been proposed for use in NASA s millimeter- and submillimeter-wave sensing instruments. Highly developed microwave <span class="hlt">oscillators</span> are used to achieve a low-noise and highly <span class="hlt">stable</span> reference signal in the 10-40-GHz band. Compact amplifiers and high-power frequency multipliers extend the signal to the 100-500-GHz band with minimal added phase noise and output power sufficient for NASA missions. This technology can achieve improved output power and frequency agility, while maintaining phase noise and stability comparable to other GDOs. Additional developments of the technology include: a frequency quadrupler to 145 GHz with 18 percent efficiency and 15 percent fixed tuned bandwidth; frequency doublers featuring 124, 240, and 480 GHz; an integrated 874-GHz subharmonic mixer with a mixer noise temperature of 3,000 K DSB (double sideband) and mixer conversion loss of 11.8 dB DSB; a high-efficiency frequency tripler design with peak output power of 23 mW and 14 mW, and efficiency of 16 and 13 percent, respectively; millimeter-wave integrated circuit (MMIC) power amplifiers to the 30-40 GHz band with high DC power efficiency; and an 874-GHz radiometer suitable for airborne observation with state-of-the-art sensitivity at room temperature and less than 5 W of total power consumption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nonli..29..257W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nonli..29..257W"><span>Turbulence in the Ott-Antonsen equation for arrays of coupled phase <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolfrum, M.; Gurevich, S. V.; Omel'chenko, O. E.</p> <p>2016-02-01</p> <p>In this paper we study the transition to synchrony in an one-dimensional array of <span class="hlt">oscillators</span> with non-local coupling. For its description in the continuum limit of a large number of phase <span class="hlt">oscillators</span>, we use a corresponding Ott-Antonsen equation, which is an integro-differential equation for the evolution of the macroscopic profiles of the local mean field. Recently, it was reported that in the spatially extended case at the synchronisation threshold there appear partially coherent plane waves with different wave numbers, which are organised in the well-known Eckhaus scenario. In this paper, we show that for Kuramoto-Sakaguchi phase <span class="hlt">oscillators</span> the phase lag parameter in the interaction function can induce a Benjamin-Feir-type instability of the partially coherent plane waves. The emerging collective macroscopic chaos appears as an intermediate stage between complete incoherence and <span class="hlt">stable</span> partially coherent plane waves. We give an analytic treatment of the Benjamin-Feir instability and its onset in a codimension-two bifurcation in the Ott-Antonsen equation as well as a numerical study of the transition from phase turbulence to amplitude turbulence inside the Benjamin-Feir unstable region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25050794','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25050794"><span>Relationship between exploitation, <span class="hlt">oscillation</span>, MSY and extinction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghosh, Bapan; Kar, T K; Legovic, T</p> <p>2014-10-01</p> <p>We give answers to two important problems arising in current fisheries: (i) how maximum sustainable yield (MSY) policy is influenced by the initial population level, and (ii) how harvesting, <span class="hlt">oscillation</span> and MSY are related to each other in prey-predator systems. To examine the impact of initial population on exploitation, we analyze a single species model with strong Allee effect. It is found that even when the MSY exists, the dynamic solution may not converge to the equilibrium stock if the initial population level is higher but near the critical threshold level. In a prey-predator system with Allee effect in the prey species, the initial population does not have such important impact neither on MSY nor on maximum sustainable total yield (MSTY). However, harvesting the top predator may cause extinction of all species if odd number of trophic levels exist in the ecosystem. With regard to the second problem, we study two prey-predator models and establish that increasing harvesting effort either on prey, predator or both prey and predator destroys previously existing <span class="hlt">oscillation</span>. Moreover, equilibrium stock both at MSY and MSTY level is <span class="hlt">stable</span>. We also discuss the validity of found results to other prey-predator systems. Copyright © 2014 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20173961','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20173961"><span>Relaxation <span class="hlt">oscillation</span> suppression in continuous-wave intracavity optical parametric <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stothard, David J M; Dunn, Malcolm H</p> <p>2010-01-18</p> <p>We report a solution to the long standing problem of the occurrence of spontaneous and long-lived bursts of relaxation <span class="hlt">oscillations</span> which occur when a continuous-wave optical parametric <span class="hlt">oscillator</span> is operated within the cavity of the parent pump-laser. By placing a second nonlinear crystal within the pump-wave cavity for the purpose of second-harmonic-generation of the pump-wave the additional nonlinear loss thereby arising due to up-conversion effectively suppresses the relaxation <span class="hlt">oscillations</span> with very little reduction in down-converted power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28875402','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28875402"><span><span class="hlt">Stable</span> Scalp EEG Spatiospectral Patterns Across Paradigms Estimated by Group ICA.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Labounek, René; Bridwell, David A; Mareček, Radek; Lamoš, Martin; Mikl, Michal; Slavíček, Tomáš; Bednařík, Petr; Baštinec, Jaromír; Hluštík, Petr; Brázdil, Milan; Jan, Jiří</p> <p>2018-01-01</p> <p>Electroencephalography (EEG) <span class="hlt">oscillations</span> reflect the superposition of different cortical sources with potentially different frequencies. Various blind source separation (BSS) approaches have been developed and implemented in order to decompose these <span class="hlt">oscillations</span>, and a subset of approaches have been developed for decomposition of multi-subject data. Group independent component analysis (Group ICA) is one such approach, revealing spatiospectral maps at the group level with distinct frequency and spatial characteristics. The reproducibility of these distinct maps across subjects and paradigms is relatively unexplored domain, and the topic of the present study. To address this, we conducted separate group ICA decompositions of EEG spatiospectral patterns on data collected during three different paradigms or tasks (resting-state, semantic decision task and visual oddball task). K-means clustering analysis of back-reconstructed individual subject maps demonstrates that fourteen different independent spatiospectral maps are present across the different paradigms/tasks, i.e. they are generally <span class="hlt">stable</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nonli..29.3897B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nonli..29.3897B"><span>Impulsive perturbations to differential equations: <span class="hlt">stable</span>/unstable pseudo-manifolds, heteroclinic connections, and flux</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balasuriya, Sanjeeva</p> <p>2016-12-01</p> <p>State-dependent time-impulsive perturbations to a two-dimensional autonomous flow with <span class="hlt">stable</span> and unstable manifolds are analysed by posing in terms of an integral equation which is valid in both forwards- and backwards-time. The impulses destroy the smooth invariant manifolds, necessitating new definitions for <span class="hlt">stable</span> and unstable pseudo-manifolds. Their time-evolution is characterised by solving a Volterra integral equation of the second kind with discontinuous inhomogeniety. A criteria for heteroclinic trajectory persistence in this impulsive context is developed, as is a quantification of an instantaneous flux across broken heteroclinic manifolds. Several examples, including a kicked Duffing <span class="hlt">oscillator</span> and an underwater explosion in the vicinity of an eddy, are used to illustrate the theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21854958','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21854958"><span>Slow <span class="hlt">oscillations</span> orchestrating fast <span class="hlt">oscillations</span> and memory consolidation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mölle, Matthias; Born, Jan</p> <p>2011-01-01</p> <p>Slow-wave sleep (SWS) facilitates the consolidation of hippocampus-dependent declarative memory. Based on the standard two-stage memory model, we propose that memory consolidation during SWS represents a process of system consolidation which is orchestrated by the neocortical <1Hz electroencephalogram (EEG) slow <span class="hlt">oscillation</span> and involves the reactivation of newly encoded representations and their subsequent redistribution from temporary hippocampal to neocortical long-term storage sites. Indeed, experimental induction of slow <span class="hlt">oscillations</span> during non-rapid eye movement (non-REM) sleep by slowly alternating transcranial current stimulation distinctly improves consolidation of declarative memory. The slow <span class="hlt">oscillations</span> temporally group neuronal activity into up-states of strongly enhanced neuronal activity and down-states of neuronal silence. In a feed-forward efferent action, this grouping is induced not only in the neocortex but also in other structures relevant to consolidation, namely the thalamus generating 10-15Hz spindles, and the hippocampus generating sharp wave-ripples, with the latter well known to accompany a replay of newly encoded memories taking place in hippocampal circuitries. The feed-forward synchronizing effect of the slow <span class="hlt">oscillation</span> enables the formation of spindle-ripple events where ripples and accompanying reactivated hippocampal memory information become nested into the single troughs of spindles. Spindle-ripple events thus enable reactivated memory-related hippocampal information to be fed back to neocortical networks in the excitable slow <span class="hlt">oscillation</span> up-state where they can induce enduring plastic synaptic changes underlying the effective formation of long-term memories. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22279905-implications-pseudo-dirac-scenario-ultra-high-energy-neutrinos-from-grbs','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22279905-implications-pseudo-dirac-scenario-ultra-high-energy-neutrinos-from-grbs"><span>Implications of the pseudo-Dirac scenario for <span class="hlt">ultra</span> high energy neutrinos from GRBs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Esmaili, Arman; Farzan, Yasaman, E-mail: aesmaili@ifi.unicamp.br, E-mail: yasaman@theory.ipm.ac.ir</p> <p>2012-12-01</p> <p>The source of <span class="hlt">Ultra</span> High Energy Cosmic Rays (UHECR) is still an unresolved mystery. Up until recently, sources of Gamma Ray Bursts (GRBs) had been considered as a suitable source for UHECR. Within the fireball model, the UHECR produced at GRBs should be accompanied with a neutrino flux detectable at the neutrino telescope such as IceCube. Recently, IceCube has set an upper bound on the neutrino flux accompanied by GRBs about 3.7 times below the prediction. We investigate whether this deficit can be explained by the <span class="hlt">oscillation</span> of the active neutrinos to sterile neutrinos en route from the source tomore » the detectors within the pseudo-Dirac scenario. We then discuss the implication of this scenario for diffuse supernova relic neutrinos.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20703303','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20703303"><span>Precipitation-generated <span class="hlt">oscillations</span> in open cellular cloud fields.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feingold, Graham; Koren, Ilan; Wang, Hailong; Xue, Huiwen; Brewer, Wm Alan</p> <p>2010-08-12</p> <p>Cloud fields adopt many different patterns that can have a profound effect on the amount of sunlight reflected back to space, with important implications for the Earth's climate. These cloud patterns can be observed in satellite images of the Earth and often exhibit distinct cell-like structures associated with organized convection at scales of tens of kilometres. Recent evidence has shown that atmospheric aerosol particles-through their influence on precipitation formation-help to determine whether cloud fields take on closed (more reflective) or open (less reflective) cellular patterns. The physical mechanisms controlling the formation and evolution of these cells, however, are still poorly understood, limiting our ability to simulate realistically the effects of clouds on global reflectance. Here we use satellite imagery and numerical models to show how precipitating clouds produce an open cellular cloud pattern that <span class="hlt">oscillates</span> between different, weakly <span class="hlt">stable</span> states. The <span class="hlt">oscillations</span> are a result of precipitation causing downward motion and outflow from clouds that were previously positively buoyant. The evaporating precipitation drives air down to the Earth's surface, where it diverges and collides with the outflows of neighbouring precipitating cells. These colliding outflows form surface convergence zones and new cloud formation. In turn, the newly formed clouds produce precipitation and new colliding outflow patterns that are displaced from the previous ones. As successive cycles of this kind unfold, convergence zones alternate with divergence zones and new cloud patterns emerge to replace old ones. The result is an <span class="hlt">oscillating</span>, self-organized system with a characteristic cell size and precipitation frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25314503','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25314503"><span>Emergence of amplitude and <span class="hlt">oscillation</span> death in identical coupled <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zou, Wei; Senthilkumar, D V; Duan, Jinqiao; Kurths, Jürgen</p> <p>2014-09-01</p> <p>We deduce rigorous conditions for the onset of amplitude death (AD) and <span class="hlt">oscillation</span> death (OD) in a system of identical coupled paradigmatic Stuart-Landau <span class="hlt">oscillators</span>. A nonscalar coupling and high frequency are beneficial for the onset of AD. In strong contrast, scalar diffusive coupling and low intrinsic frequency are in favor of the emergence of OD. Our finding contributes to clearly distinguish intrinsic geneses for AD and OD, and further substantially corroborates that AD and OD are indeed two dynamically distinct <span class="hlt">oscillation</span> quenching phenomena due to distinctly different mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JSemi..32f5008Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JSemi..32f5008Q"><span>An <span class="hlt">ultra</span>-low-power RF transceiver for WBANs in medical applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qi, Zhang; Xiaofei, Kuang; Nanjian, Wu</p> <p>2011-06-01</p> <p>A 2.4 GHz <span class="hlt">ultra</span>-low-power RF transceiver with a 900 MHz auxiliary wake-up link for wireless body area networks (WBANs) in medical applications is presented. The RF transceiver with an asymmetric architecture is proposed to achieve high energy efficiency according to the asymmetric communication in WBANs. The transceiver consists of a main receiver (RX) with an <span class="hlt">ultra</span>-low-power free-running ring <span class="hlt">oscillator</span> and a high speed main transmitter (TX) with fast lock-in PLL. A passive wake-up receiver (WuRx) for wake-up function with a high power conversion efficiency (PCE) CMOS rectifier is designed to offer the sensor node the capability of work-on-demand with zero standby power. The chip is implemented in a 0.18 μm CMOS process. Its core area is 1.6 mm2. The main RX achieves a sensitivity of -55 dBm at a 100 kbps OOK data rate while consuming just 210 μA current from the 1 V power supply. The main TX achieves +3 dBm output power with a 4 Mbps/500 kbps/200 kbps data rate for OOK/4 FSK/2 FSK modulation and dissipates 3.25 mA/6.5 mA/6.5 mA current from a 1.8 V power supply. The minimum detectable RF input energy for the wake-up RX is -15 dBm and the PCE is more than 25%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090035884','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090035884"><span><span class="hlt">Ultra</span>-Large Solar Sail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burton, Rodney; Coverstone, Victoria</p> <p>2009-01-01</p> <p><span class="hlt">Ultra</span>Sail is a next-generation <span class="hlt">ultra</span>-large (km2 class) sail system. Analysis of the launch, deployment, stabilization, and control of these sails shows that high-payload-mass fractions for interplanetary and deep-space missions are possible. <span class="hlt">Ultra</span>Sail combines propulsion and control systems developed for formation-flying microsatellites with a solar sail architecture to achieve controllable sail areas approaching 1 km2. Electrically conductive CP-1 polyimide film results in sail subsystem area densities as low as 5 g/m2. <span class="hlt">Ultra</span>Sail produces thrust levels many times those of ion thrusters used for comparable deep-space missions. The primary innovation involves the near-elimination of sail-supporting structures by attaching each blade tip to a formation- flying microsatellite, which deploys the sail and then articulates the sail to provide attitude control, including spin stabilization and precession of the spin axis. These microsatellite tips are controlled by microthrusters for sail-film deployment and mission operations. <span class="hlt">Ultra</span>Sail also avoids the problems inherent in folded sail film, namely stressing, yielding, or perforating, by storing the film in a roll for launch and deployment. A 5-km long by 2 micrometer thick film roll on a mandrel with a 1 m circumference (32 cm diameter) has a stored thickness of 5 cm. A 5 m-long mandrel can store a film area of 25,000 m2, and a four-blade system has an area of 0.1 sq km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhRvE..80b1908T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhRvE..80b1908T"><span>Predicting synchrony in heterogeneous pulse coupled <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Talathi, Sachin S.; Hwang, Dong-Uk; Miliotis, Abraham; Carney, Paul R.; Ditto, William L.</p> <p>2009-08-01</p> <p>Pulse coupled <span class="hlt">oscillators</span> (PCOs) represent an ubiquitous model for a number of physical and biological systems. Phase response curves (PRCs) provide a general mathematical framework to analyze patterns of synchrony generated within these models. A general theoretical approach to account for the nonlinear contributions from higher-order PRCs in the generation of synchronous patterns by the PCOs is still lacking. Here, by considering a prototypical example of a PCO network, i.e., two synaptically coupled neurons, we present a general theory that extends beyond the weak-coupling approximation, to account for higher-order PRC corrections in the derivation of an approximate discrete map, the <span class="hlt">stable</span> fixed point of which can predict the domain of 1:1 phase locked synchronous states generated by the PCO network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.211.1254Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.211.1254Z"><span>Matrix eigenvalue method for free-<span class="hlt">oscillations</span> modelling of spherical elastic bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zábranová, E.; Hanyk, L.; Matyska, C.</p> <p>2017-11-01</p> <p>Deformations and changes of the gravitational potential of pre-stressed self-gravitating elastic bodies caused by free <span class="hlt">oscillations</span> are described by means of the momentum and Poisson equations and the constitutive relation. For spherically symmetric bodies, the equations and boundary conditions are transformed into ordinary differential equations of the second order by the spherical harmonic decomposition and further discretized by highly accurate pseudospectral difference schemes on Chebyshev grids; we pay special attention to the conditions at the centre of the models. We thus obtain a series of matrix eigenvalue problems for eigenfrequencies and eigenfunctions of the free <span class="hlt">oscillations</span>. Accuracy of the presented numerical approach is tested by means of the Rayleigh quotients calculated for the eigenfrequencies up to 500 mHz. Both the modal frequencies and eigenfunctions are benchmarked against the output from the Mineos software package based on shooting methods. The presented technique is a promising alternative to widely used methods because it is <span class="hlt">stable</span> and with a good capability up to high frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApSS..427.1092W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApSS..427.1092W"><span>Structurally <span class="hlt">stable</span> graphene oxide-based nanofiltration membranes with bioadhesive polydopamine coating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chongbin; Li, Zhiyuan; Chen, Jianxin; Yin, Yongheng; Wu, Hong</p> <p>2018-01-01</p> <p>Graphene oxide (GO)-based membranes possess promising potential in liquid separation for its high flux. The state-of-art GO-based membranes need to be supported by a substrate to ensure that the <span class="hlt">ultra</span>-thin GO layer can withstand transmembrane pressure in practical applications. The interfacial compatibility of this kind of composite membrane remains a great challenge due to the intrinsic difference in chemical/physical properties between the GO sheets and the substrate. In this paper, a structurally <span class="hlt">stable</span> GO-based composite nanofiltration membrane was fabricated by coupling the mussel-inspired adhesive platform and filtration-assisted assembly of GO laminates. The water flux for the prepared GO-based nanofiltration membrane reached up to 85 L m-2 h-1 bar-1 with a high retention above 95% and 100% for Orange G and Congo Red, respectively. The membrane exhibited highly <span class="hlt">stable</span> structure owing to the covalent and noncovalent interactions between GO separation layer and dopamine adhesive platform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110022592','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110022592"><span>Nonlinear <span class="hlt">Oscillators</span> in Space Physics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lester,Daniel; Thronson, Harley</p> <p>2011-01-01</p> <p>We discuss dynamical systems that produce an <span class="hlt">oscillation</span> without an external time dependent source. Numerical results are presented for nonlinear <span class="hlt">oscillators</span> in the Em1h's atmosphere, foremost the quasi-biennial <span class="hlt">oscillation</span> (QBOl. These fluid dynamical <span class="hlt">oscillators</span>, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has particular form. of 3rd or odd power. It is shown that this form of nonlinearity can produce the fundamental li'equency of the internal <span class="hlt">oscillation</span>. which has a period that is favored by the dynamical condition of the fluid. The fundamental frequency maintains the <span class="hlt">oscillation</span>, with no energy input to the system at that particular frequency. Nonlinearities of 2nd or even power could not maintain the <span class="hlt">oscillation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11367776','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11367776"><span>A microwave exciter for Cs frequency standards based on a sapphire-loaded cavity <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koga, Y; McNeilage, C; Searls, J H; Ohshima, S</p> <p>2001-01-01</p> <p>A low noise and highly <span class="hlt">stable</span> microwave exciter system has been built for Cs atomic frequency standards using a tunable sapphire-loaded cavity <span class="hlt">oscillator</span> (SLCO), which works at room temperature. This paper discusses the successful implementation of a control system for locking the SLCO to a long-term reference signal and reports an upper limit of the achieved frequency tracking error 6 x 10(-15) at tau = 1 s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-09-26/pdf/2012-23701.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-09-26/pdf/2012-23701.pdf"><span>77 FR 59182 - <span class="hlt">Ultra</span>-Deepwater Advisory Committee</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-09-26</p> <p>... DEPARTMENT OF ENERGY <span class="hlt">Ultra</span>-Deepwater Advisory Committee AGENCY: Office of Fossil Energy... of the <span class="hlt">Ultra</span>-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to <span class="hlt">ultra</span>-deepwater architecture and technology to the Secretary of Energy and provide...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26950828','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26950828"><span>Where Is the Electronic <span class="hlt">Oscillator</span> Strength? Mapping <span class="hlt">Oscillator</span> Strength across Molecular Absorption Spectra.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Lianjun; Polizzi, Nicholas F; Dave, Adarsh R; Migliore, Agostino; Beratan, David N</p> <p>2016-03-24</p> <p>The effectiveness of solar energy capture and conversion materials derives from their ability to absorb light and to transform the excitation energy into energy stored in free carriers or chemical bonds. The Thomas-Reiche-Kuhn (TRK) sum rule mandates that the integrated (electronic) <span class="hlt">oscillator</span> strength of an absorber equals the total number of electrons in the structure. Typical molecular chromophores place only about 1% of their <span class="hlt">oscillator</span> strength in the UV-vis window, so individual chromophores operate at about 1% of their theoretical limit. We explore the distribution of <span class="hlt">oscillator</span> strength as a function of excitation energy to understand this circumstance. To this aim, we use familiar independent-electron model Hamiltonians as well as first-principles electronic structure methods. While model Hamiltonians capture the qualitative electronic spectra associated with π electron chromophores, these Hamiltonians mistakenly focus the <span class="hlt">oscillator</span> strength in the fewest low-energy transitions. Advanced electronic structure methods, in contrast, spread the <span class="hlt">oscillator</span> strength over a very wide excitation energy range, including transitions to Rydberg and continuum states, consistent with experiment. Our analysis rationalizes the low <span class="hlt">oscillator</span> strength in the UV-vis spectral region in molecules, a step toward the goal of <span class="hlt">oscillator</span> strength manipulation and focusing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950016581','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950016581"><span>The Duffin-Kemmer-Petiau <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nedjadi, Youcef; Barrett, Roger</p> <p>1995-01-01</p> <p>In view of current interest in relativistic spin-one systems and the recent work on the Dirac <span class="hlt">Oscillator</span>, we introduce the Duffin-Kemmer-Petiau (DKP) equation obtained by using an external potential linear in r. Since, in the non-relativistic limit, the spin 1 representation leads to a harmonic <span class="hlt">oscillator</span> with a spin-orbit coupling of the Thomas form, we call the equation the DKP <span class="hlt">oscillator</span>. This <span class="hlt">oscillator</span> is a relativistic generalization of the quantum harmonic <span class="hlt">oscillator</span> for scalar and vector bosons. We show that it conserves total angular momentum and that it is exactly solvable. We calculate and discuss the eigenspectrum of the DKP <span class="hlt">oscillator</span> in the spin 1 representation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=mechanical+AND+properties&pg=3&id=EJ880913','ERIC'); return false;" href="https://eric.ed.gov/?q=mechanical+AND+properties&pg=3&id=EJ880913"><span>Magnetically Coupled Magnet-Spring <span class="hlt">Oscillators</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Donoso, G.; Ladera, C. L.; Martin, P.</p> <p>2010-01-01</p> <p>A system of two magnets hung from two vertical springs and <span class="hlt">oscillating</span> in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled <span class="hlt">oscillators</span>. The electromagnetically coupled <span class="hlt">oscillations</span> of these <span class="hlt">oscillators</span> are experimentally and theoretically studied. Its coupling is electromagnetic instead of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-08-10/pdf/2010-19710.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-08-10/pdf/2010-19710.pdf"><span>75 FR 48319 - <span class="hlt">Ultra</span>-Deepwater Advisory Committee</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-08-10</p> <p>... DEPARTMENT OF ENERGY <span class="hlt">Ultra</span>-Deepwater Advisory Committee AGENCY: Department of Energy, Office of...: Purpose of the Committee: The purpose of the <span class="hlt">Ultra</span>-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to <span class="hlt">ultra</span>-deepwater architecture and technology to the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-12-15/pdf/2011-32160.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-12-15/pdf/2011-32160.pdf"><span>76 FR 77990 - <span class="hlt">Ultra</span>-Deepwater Advisory Committee</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-12-15</p> <p>... DEPARTMENT OF ENERGY <span class="hlt">Ultra</span>-Deepwater Advisory Committee AGENCY: Office of Fossil Energy... Committee: The purpose of the <span class="hlt">Ultra</span>-Deepwater Advisory Committee is to provide advice to the Secretary of Energy on development and implementation of programs related to <span class="hlt">ultra</span>-deepwater natural gas and other...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-02-08/pdf/2011-2762.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-02-08/pdf/2011-2762.pdf"><span>76 FR 6775 - <span class="hlt">Ultra</span>-Deepwater Advisory Committee</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-02-08</p> <p>... DEPARTMENT OF ENERGY <span class="hlt">Ultra</span>-Deepwater Advisory Committee AGENCY: Department of Energy, Office of... Committee: The purpose of the <span class="hlt">Ultra</span>-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to <span class="hlt">ultra</span>-deepwater architecture and technology to the Secretary of Energy and...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-09-09/pdf/2010-22540.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-09-09/pdf/2010-22540.pdf"><span>75 FR 54860 - <span class="hlt">Ultra</span> Deepwater Advisory Committee</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-09-09</p> <p>... DEPARTMENT OF ENERGY <span class="hlt">Ultra</span> Deepwater Advisory Committee AGENCY: Department of Energy, Office of... of an open meeting of the <span class="hlt">Ultra</span> Deepwater Advisory Committee. The Committee was organized pursuant to.../advisorycommittees/<span class="hlt">Ultra</span>Deepwater.html . Issued in Washington, DC, on September 3, 2010. Carol A. Matthews, Committee...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20059200','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20059200"><span>Identical phase <span class="hlt">oscillators</span> with global sinusoidal coupling evolve by Mobius group action.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marvel, Seth A; Mirollo, Renato E; Strogatz, Steven H</p> <p>2009-12-01</p> <p>Systems of N identical phase <span class="hlt">oscillators</span> with global sinusoidal coupling are known to display low-dimensional dynamics. Although this phenomenon was first observed about 20 years ago, its underlying cause has remained a puzzle. Here we expose the structure working behind the scenes of these systems by proving that the governing equations are generated by the action of the Mobius group, a three-parameter subgroup of fractional linear transformations that map the unit disk to itself. When there are no auxiliary state variables, the group action partitions the N-dimensional state space into three-dimensional invariant manifolds (the group orbits). The N-3 constants of motion associated with this foliation are the N-3 functionally independent cross ratios of the <span class="hlt">oscillator</span> phases. No further reduction is possible, in general; numerical experiments on models of Josephson junction arrays suggest that the invariant manifolds often contain three-dimensional regions of neutrally <span class="hlt">stable</span> chaos.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920024122&hterms=computer+applications&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcomputer%2Bapplications','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920024122&hterms=computer+applications&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcomputer%2Bapplications"><span>Universal, computer facilitated, steady state <span class="hlt">oscillator</span>, closed loop analysis theory and some applications to precision <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parzen, Benjamin</p> <p>1992-01-01</p> <p>The theory of <span class="hlt">oscillator</span> analysis in the immittance domain should be read in conjunction with the additional theory presented here. The combined theory enables the computer simulation of the steady state <span class="hlt">oscillator</span>. The simulation makes the calculation of the <span class="hlt">oscillator</span> total steady state performance practical, including noise at all <span class="hlt">oscillator</span> locations. Some specific precision <span class="hlt">oscillators</span> are analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28681947','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28681947"><span>Speech-like orofacial <span class="hlt">oscillations</span> in stump-tailed macaque (Macaca arctoides) facial and vocal signals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toyoda, Aru; Maruhashi, Tamaki; Malaivijitnond, Suchinda; Koda, Hiroki</p> <p>2017-10-01</p> <p>Speech is unique to humans and characterized by facial actions of ∼5 Hz <span class="hlt">oscillations</span> of lip, mouth or jaw movements. Lip-smacking, a facial display of primates characterized by oscillatory actions involving the vertical opening and closing of the jaw and lips, exhibits <span class="hlt">stable</span> 5-Hz <span class="hlt">oscillation</span> patterns, matching that of speech, suggesting that lip-smacking is a precursor of speech. We tested if facial or vocal actions exhibiting the same rate of <span class="hlt">oscillation</span> are found in wide forms of facial or vocal displays in various social contexts, exhibiting diversity among species. We observed facial and vocal actions of wild stump-tailed macaques (Macaca arctoides), and selected video clips including facial displays (teeth chattering; TC), panting calls, and feeding. Ten open-to-open mouth durations during TC and feeding and five amplitude peak-to-peak durations in panting were analyzed. Facial display (TC) and vocalization (panting) <span class="hlt">oscillated</span> within 5.74 ± 1.19 and 6.71 ± 2.91 Hz, respectively, similar to the reported lip-smacking of long-tailed macaques and the speech of humans. These results indicated a common mechanism for the central pattern generator underlying orofacial movements, which would evolve to speech. Similar <span class="hlt">oscillations</span> in panting, which evolved from different muscular control than the orofacial action, suggested the sensory foundations for perceptual saliency particular to 5-Hz rhythms in macaques. This supports the pre-adaptation hypothesis of speech evolution, which states a central pattern generator for 5-Hz facial <span class="hlt">oscillation</span> and perceptual background tuned to 5-Hz actions existed in common ancestors of macaques and humans, before the emergence of speech. © 2017 Wiley Periodicals, Inc.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010114147&hterms=personality&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpersonality','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010114147&hterms=personality&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpersonality"><span><span class="hlt">Ultra</span>Net Target Parameters. Chapter 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kislitzin, Katherine T.; Blaylock, Bruce T. (Technical Monitor)</p> <p>1992-01-01</p> <p>The <span class="hlt">Ultra</span>Net is a high speed network capable of rates up to one gigabit per second. It is a hub based network with four optical fiber links connecting each hub. Each link can carry up to 256 megabits of data, and the hub backplane is capable of one gigabit aggregate throughput. Host connections to the hub may be fiber, coax, or channel based. Bus based machines have adapter boards that connect to transceivers in the hub, while channel based machines use a personality module in the hub. One way that the <span class="hlt">Ultra</span>Net achieves its high transfer rates is by off-loading the protocol processing from the hosts to special purpose protocol engines in the <span class="hlt">Ultra</span>Net hubs. In addition, every hub has a PC connected to it by StarLAN for network management purposes. Although there is hub resident and PC resident <span class="hlt">Ultra</span>Net software, this document treats only the host resident <span class="hlt">Ultra</span>Net software.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28734908','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28734908"><span>Why transition risk to psychosis is not declining at the OASIS <span class="hlt">ultra</span> high risk service: The hidden role of <span class="hlt">stable</span> pretest risk enrichment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fusar-Poli, P; Palombini, E; Davies, C; Oliver, D; Bonoldi, I; Ramella-Cravaro, V; McGuire, P</p> <p>2018-02-01</p> <p>The reason for declining risk to psychosis across individuals assessed and meeting <span class="hlt">Ultra</span> High Risk (UHR) criteria is still unclear. No studies have investigated the potential substantial role of the underlying risk enrichment across all the individuals undergoing an UHR assessment. Cohort study including all non-psychotic subjects who were assessed on suspicion of psychosis risk by the OASIS UHR service in the period 2001 to 2015. Posttest (after UHR assessment) and pretest risk (before UHR assessment) of psychosis were stratified and compared across three time periods (2001-2005, 2006-2010, 2011-2015) with Cox analysis and modulating factors were investigated. The posttest risk of psychosis at the OASIS service has increased from the initial pilot years of the service (2001-2005) and then stabilised and not declined over the following decade (2006-2010 and 2011-2015). This was paralleled by a similar course of pretest risk for psychosis. Stability of pretest risk for psychosis over the past decade was associated with a lack of change in ethnicity and to counterweighting changes in the type of referral sources over different time periods. The time course of transition risk to psychosis in UHR services is strictly associated with the time course of pretest risk enrichment. If the latter remains <span class="hlt">stable</span> over time, as for the OASIS service, no declining transition risk is observed over the most recent years. Pretest risk enrichment is determined by recruitment and sampling strategies. This study confirms the need to control these factors in the UHR field. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhLB..776....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhLB..776....1H"><span>On the number of light rings in curved spacetimes of <span class="hlt">ultra</span>-compact objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hod, Shahar</p> <p>2018-01-01</p> <p>In a very interesting paper, Cunha, Berti, and Herdeiro have recently claimed that <span class="hlt">ultra</span>-compact objects, self-gravitating horizonless solutions of the Einstein field equations which have a light ring, must possess at least two (and, in general, an even number of) light rings, of which the inner one is <span class="hlt">stable</span>. In the present compact paper we explicitly prove that, while this intriguing theorem is generally true, there is an important exception in the presence of degenerate light rings which, in the spherically symmetric static case, are characterized by the simple dimensionless relation 8 πrγ2 (ρ +pT) = 1 [here rγ is the radius of the light ring and { ρ ,pT } are respectively the energy density and tangential pressure of the matter fields]. <span class="hlt">Ultra</span>-compact objects which belong to this unique family can have an odd number of light rings. As a concrete example, we show that spherically symmetric constant density stars with dimensionless compactness M / R = 1 / 3 possess only one light ring which, interestingly, is shown to be unstable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......229M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......229M"><span>Investigation of combustion control in a dump combustor using the feedback free fluidic <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meier, Eric J.</p> <p></p> <p> mechanism by which the fluidic <span class="hlt">oscillators</span> were able to suppress the combustion instability. Results for steady jet secondary injection, showed a strong coupling between the jet injection and the combustion instability pressure pulse. The computational results were able to closely match the experimental results and previous CFD data. The model with the <span class="hlt">oscillating</span> fluidic <span class="hlt">oscillator</span> injection was unable to match the <span class="hlt">stable</span> combustion seen in the experimental data. Further investigation is needed to determine the role higher order chemistry kinetics play in the process and the role of manifolds on the un-choked fuel and fluidic <span class="hlt">oscillator</span> inlets. This research demonstrates the ability to modulate propellant injection and suppress combustion instabilities using fluidic devices that require no electrical power or moving parts. The advent of advanced manufacturing technologies such as direct metal laser sintering will allow for integration of fluidic devices into combustors to provide open loop active control with a high degree of reliability. Additionally, 2-D CFD analysis is demonstrated to be a valid tool for predicting the feedback free fluidic <span class="hlt">oscillator</span> <span class="hlt">oscillation</span> mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21110009','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21110009"><span>Use of recombinantly produced 15N3-labelled nicotianamine for fast and sensitive <span class="hlt">stable</span> isotope dilution <span class="hlt">ultra</span>-performance liquid chromatography/electrospray ionization time-of-flight mass spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmidt, Holger; Böttcher, Christoph; Trampczynska, Aleksandra; Clemens, Stephan</p> <p>2011-01-01</p> <p>Nicotianamine (NA) is an important metal chelator, implicated in the intra- and intercellular trafficking of several transition metal ions in plants. To decipher its roles in physiological processes such as micronutrient acquisition, distribution or storage, fast and sensitive analytical techniques for quantification of this non-proteinogenic amino acid will be required. The use of a recombinant Schizosaccharomyces pombe strain expressing a nicotianamine synthase (NAS) gene allowed for the production of [(15)N(3)]-NA, which was enriched from cell extracts through cation exchange and used for <span class="hlt">stable</span> isotope dilution analysis of NA. Such an approach should be widely applicable to important bioanalytes that are difficult to synthesize. The analytical procedure comprises mild aqueous extraction and rapid Fmoc derivatization, followed by fast separation using <span class="hlt">ultra</span>-performance liquid chromatography (UPLC) and sensitive detection by positive ion electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) with a chromatographic cycle time of only 8 min. Derivatization was optimized with respect to incubation time and species suitable for quantification. The limit of detection was 0.14 to 0.23 pmol in biological matrices with the response being linear up to 42 pmol. Recovery rates were between 83% and 104% in various biological matrices including fission yeast cells, fungal mycelium, plant leaves and roots.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1044932','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1044932"><span>Neutrino <span class="hlt">Oscillation</span> Physics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kayser, Boris</p> <p>2012-06-01</p> <p>To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino <span class="hlt">oscillation</span>. This description is centered on a new way of deriving the <span class="hlt">oscillation</span> probability. We also provide a brief guide to references relevant to topics other than neutrino <span class="hlt">oscillation</span> that were covered in the lectures. Neutrinos and photons are by far themore » most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino <span class="hlt">oscillation</span>. We shall explain the physics of neutrino <span class="hlt">oscillation</span>, deriving the probability of <span class="hlt">oscillation</span> in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino <span class="hlt">oscillation</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.nrel.gov/grid/virtual-oscillator-controls.html','SCIGOVWS'); return false;" href="https://www.nrel.gov/grid/virtual-oscillator-controls.html"><span>Virtual <span class="hlt">Oscillator</span> Controls | Grid Modernization | NREL</span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p><em>Virtual</em> <span class="hlt">Oscillator</span> Controls <em>Virtual</em> <span class="hlt">Oscillator</span> Controls NREL is developing <em>virtual</em> <span class="hlt">oscillator</span> Santa-Barbara, and SunPower. Publications Synthesizing <em>Virtual</em> <span class="hlt">Oscillators</span> To Control Islanded Inverters Synchronization of Parallel Single-Phase Inverters Using <em>Virtual</em> <span class="hlt">Oscillator</span> Control, IEEE Transactions on Power</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22308585-novel-femtosecond-gated-high-resolution-frequency-shifted-shearing-interferometry-technique-probing-pre-plasma-expansion-ultra-intense-laser-experiments','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22308585-novel-femtosecond-gated-high-resolution-frequency-shifted-shearing-interferometry-technique-probing-pre-plasma-expansion-ultra-intense-laser-experiments"><span>A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in <span class="hlt">ultra</span>-intense laser experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Feister, S., E-mail: feister.7@osu.edu; Orban, C.; Innovative Scientific Solutions, Inc., Dayton, Ohio 45459</p> <p></p> <p><span class="hlt">Ultra</span>-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main <span class="hlt">ultra</span>-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an <span class="hlt">ultra</span>-intense laser experiment that uses two short-pulse amplifiersmore » synchronized by one <span class="hlt">ultra</span>-fast seed <span class="hlt">oscillator</span> to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the <span class="hlt">ultra</span>-intense pulse arrives. Such measurements are indispensable for correlating laser pre</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA127519','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA127519"><span><span class="hlt">Ultra-Stable</span> Laser Clock.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1983-03-01</p> <p>43. L circumference of ring laser cavity 44. LF pathlength through Faraday rotator 45. 1 distance between resonator mirrors of linear laser 46. M...limited clock stability 68. q mode number 69. Ri reflectivity of mirror i 70. eF angle between magnetic field and direction of light propagation 71...containing low pressure methane. The light reflects off a mirror and passes back through the cell. Then the light reflects from the beam splitter into</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4312358','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4312358"><span>HIGH POWER PULSED <span class="hlt">OSCILLATOR</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Singer, S.; Neher, L.K.</p> <p>1957-09-24</p> <p>A high powered, radio frequency pulse <span class="hlt">oscillator</span> is described for generating trains of <span class="hlt">oscillations</span> at the instant an input direct voltage is impressed, or immediately upon application of a light pulse. In one embodiment, the pulse <span class="hlt">oscillator</span> comprises a photo-multiplier tube with the cathode connected to the first dynode by means of a resistor, and adjacent dynodes are connected to each other through adjustable resistors. The ohmage of the resistors progressively increases from a very low value for resistors adjacent the cathode to a high value adjacent the plate, the last dynode. <span class="hlt">Oscillation</span> occurs with this circuit when a high negative voltage pulse is applied to the cathode and the photo cathode is bombarded. Another embodiment adds capacitors at the resistor connection points of the above circuit to increase the duration of the <span class="hlt">oscillator</span> train.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LRSP...15....3A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LRSP...15....3A"><span>Prominence <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arregui, Iñigo; Oliver, Ramón; Ballester, José Luis</p> <p>2018-04-01</p> <p>Prominences are intriguing, but poorly understood, magnetic structures of the solar corona. The dynamics of solar prominences has been the subject of a large number of studies, and of particular interest is the study of prominence <span class="hlt">oscillations</span>. Ground- and space-based observations have confirmed the presence of oscillatory motions in prominences and they have been interpreted in terms of magnetohydrodynamic waves. This interpretation opens the door to perform prominence seismology, whose main aim is to determine physical parameters in magnetic and plasma structures (prominences) that are difficult to measure by direct means. Here, we review the observational information gathered about prominence <span class="hlt">oscillations</span> as well as the theoretical models developed to interpret small and large amplitude <span class="hlt">oscillations</span> and their temporal and spatial attenuation. Finally, several prominence seismology applications are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.111u3901U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.111u3901U"><span>Sustaining high-energy orbits of bi-<span class="hlt">stable</span> energy harvesters by attractor selection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Udani, Janav P.; Arrieta, Andres F.</p> <p>2017-11-01</p> <p>Nonlinear energy harvesters have the potential to efficiently convert energy over a wide frequency range; however, difficulties in attaining and sustaining high-energy <span class="hlt">oscillations</span> restrict their applicability in practical scenarios. In this letter, we propose an actuation methodology to switch the state of bi-<span class="hlt">stable</span> harvesters from the low-energy intra-well configuration to the coexisting high-energy inter-well configuration by controlled phase shift perturbations. The strategy is designed to introduce a change in the system state without creating distinct metastable attractors by exploiting the basins of attraction of the coexisting <span class="hlt">stable</span> attractors. Experimental results indicate that the proposed switching strategy yields a significant improvement in energy transduction capabilities, is highly economical, enabling the rapid recovery of energy spent in the disturbance, and can be practically implemented with widely used low-strain piezoelectric transducers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19466195','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19466195"><span>Pattern formation without diffraction matching in optical parametric <span class="hlt">oscillators</span> with a metamaterial.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tassin, Philippe; Van der Sande, Guy; Veretennicoff, Irina; Kockaert, Pascal; Tlidi, Mustapha</p> <p>2009-05-25</p> <p>We consider a degenerate optical parametric <span class="hlt">oscillator</span> containing a left-handed material. We show that the inclusion of a left-handed material layer allows for controlling the strength and sign of the diffraction coefficient at either the pump or the signal frequency. Subsequently, we demonstrate the existence of <span class="hlt">stable</span> dissipative structures without diffraction matching, i.e., without the usual relationship between the diffraction coefficients of the signal and pump fields. Finally, we investigate the size scaling of these light structures with decreasing diffraction strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22156816-stable-bounded-excursion-gravastars-black-holes-einstein-theory-gravity','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22156816-stable-bounded-excursion-gravastars-black-holes-einstein-theory-gravity"><span><span class="hlt">Stable</span> and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rocha, P; Da Silva, M F A; Wang, Anzhong</p> <p>2008-11-15</p> <p>Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent <span class="hlt">stable</span> gravastars, and in some cases they represent 'bounded excursion' <span class="hlt">stable</span> gravastars, where the thin shell is <span class="hlt">oscillating</span> between two finite radii, while in some other cases they collapse until themore » formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both <span class="hlt">stable</span> gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AAS...205.4802T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AAS...205.4802T"><span>The <span class="hlt">Ultra</span>Lightweight Technology for Research in Astronomy (<span class="hlt">ULTRA</span>) Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Twarog, B. A.; Anthony-Twarog, B. J.; Shawl, S. J.; Hale, R.; Taghavi, R.; Fesen, R.; Etzel, P. B.; Martin, R.; Romeo, R.</p> <p>2004-12-01</p> <p>The collaborative focus of four academic departments (Univ. of Kansas Aerospace Engineering, Univ. of Kansas Physics & Astronomy, San Diego State University Astronomy and Dartmouth College Astronomy) and a private industry partner (Composite Mirror Applications, Inc.-CMA, Inc.) is a three-year plan to develop and test <span class="hlt">Ultra</span>Lightweight Technology for Research in Astronomy (<span class="hlt">ULTRA</span>). The <span class="hlt">ULTRA</span> technology, using graphite fiber composites to fabricate mirrors and telescope structures, offers a versatile and cost-effective tool for optical astronomy, including the economical fabrication and operation of telescopes ranging from small (1m or smaller) aperture for education and research to extremely large (30m+) segmented telescopes (ELTs). The specific goal of this NSF-funded three-year Major Research Instrumentation project is to design, build, and test a 1m-class optical tube assembly (OTA) and mirrors constructed entirely from composites. In the first year of the project, the team has built and is field-testing two 0.4m prototypes to validate the optical surfaces and figures of the mirrors and to test and refine the structural dynamics of the OTA. Preparation for design and construction of the 1m telescope is underway. When completed in late 2005, the <span class="hlt">ULTRA</span> telescope will be operated remotely from Mt. Laguna Observatory east of San Diego, where it will undergo a period of intensive optical and imaging tests. A 0.4m prototype OTA with mirrors (12 kg total weight) will be on display at the meeting. Support of this work by NSF through grants AST-0320784 and AST-0321247, NASA grant NCC5-600, the University of Kansas, and San Diego State University is gratefully acknowledged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...121l3103H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...121l3103H"><span>Analogue of <span class="hlt">ultra</span>-broadband and polarization-independent electromagnetically induced transparency using planar metamaterial</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Sen; Liu, Dan; Lin, Hai; Chen, Jiao; Yi, Yuanyuan; Yang, Helin</p> <p>2017-03-01</p> <p>In this paper, a classical analogue of electromagnetically induced transparency (EIT) metamaterial is numerically and experimentally demonstrated. The unit cell of our proposed structure is composed of two identical and orthogonal double-end fork (DEF) metallic resonators. Under the excitation of the normally incident waves, each of the two DEFs exhibits different frequency of electric dipole response, which leads to the <span class="hlt">ultra</span>-broadband and polarization-independent EIT-like effect. The resonant feature of the EIT-like effect has been qualitatively analyzed from the surface current distributions and quantitatively by the "two-<span class="hlt">oscillator</span>" coupling model. In addition, the large group index is extracted to verify the slow light property within the transmission window. The EIT metamaterial structure with the above-mentioned characteristics may have potential applications in some areas, such as sensing, slow light, and filtering devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020092093','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020092093"><span>Rocket Engine <span class="hlt">Oscillation</span> Diagnostics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nesman, Tom; Turner, James E. (Technical Monitor)</p> <p>2002-01-01</p> <p>Rocket engine <span class="hlt">oscillating</span> data can reveal many physical phenomena ranging from unsteady flow and acoustics to rotordynamics and structural dynamics. Because of this, engine diagnostics based on <span class="hlt">oscillation</span> data should employ both signal analysis and physical modeling. This paper describes an approach to rocket engine <span class="hlt">oscillation</span> diagnostics, types of problems encountered, and example problems solved. Determination of design guidelines and environments (or loads) from <span class="hlt">oscillating</span> phenomena is required during initial stages of rocket engine design, while the additional tasks of health monitoring, incipient failure detection, and anomaly diagnostics occur during engine development and operation. <span class="hlt">Oscillations</span> in rocket engines are typically related to flow driven acoustics, flow excited structures, or rotational forces. Additional sources of oscillatory energy are combustion and cavitation. Included in the example problems is a sampling of signal analysis tools employed in diagnostics. The rocket engine hardware includes combustion devices, valves, turbopumps, and ducts. Simple models of an <span class="hlt">oscillating</span> fluid system or structure can be constructed to estimate pertinent dynamic parameters governing the unsteady behavior of engine systems or components. In the example problems it is shown that simple physical modeling when combined with signal analysis can be successfully employed to diagnose complex rocket engine oscillatory phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25833734','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25833734"><span>Grapheme-color synesthesia subtypes: <span class="hlt">Stable</span> individual differences reflected in posterior alpha-band <span class="hlt">oscillations</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cohen, Michael X; Weidacker, Kathrin; Tankink, Judith; Scholte, H Steven; Rouw, Romke</p> <p>2015-01-01</p> <p>Grapheme-color synesthesia is a condition in which seeing letters and numbers produces sensations of colors (e.g., the letter R may elicit a sky-blue percept). Recent evidence implicates posterior parietal areas, in addition to lower-level sensory processing regions, in the neurobiological mechanisms involved in synesthesia. Furthermore, these mechanisms seem to differ for "projectors" (synesthetes who report seeing the color "out there in the real world") versus "associators" (synesthetes who report the color to be only an internal experience). Relatively little is known about possible electrophysiological characteristics of grapheme-color synesthesia. Here we used EEG to investigate functional oscillatory differences among associators, projectors, and non-synesthetes. Projectors had stronger stimulus-related alpha-band (~10 Hz) power over posterior parietal electrodes, compared to both associators and non-synesthetes. Posterior alpha activity was not statistically significantly different between associators from non-synesthetes. We also performed a test-retest assessment of the projector-associator score and found strong retest reliability, as evidenced by a correlation coefficient of .85. These findings demonstrate that the projector-associator distinction is highly reliable over time and is related to neural <span class="hlt">oscillations</span> in the alpha band.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhPl...17a4505B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhPl...17a4505B"><span>Ionization <span class="hlt">oscillations</span> in Hall accelerators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barral, S.; Peradzyński, Z.</p> <p>2010-01-01</p> <p>The underlying mechanism of low-frequency <span class="hlt">oscillations</span> in Hall accelerators is investigated theoretically. It is shown that relaxation <span class="hlt">oscillations</span> arise from a competition between avalanche ionization and the advective transport of the working gas. The model derived recovers the slow progression and fast recession of the ionization front. Analytical approximations of the shape of current pulses and of the <span class="hlt">oscillation</span> frequency are provided for the case of large amplitude <span class="hlt">oscillations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10085E..0SS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10085E..0SS"><span>Environmentally <span class="hlt">stable</span> seed source for high power ultrafast laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samartsev, Igor; Bordenyuk, Andrey; Gapontsev, Valentin</p> <p>2017-02-01</p> <p>We present an environmentally <span class="hlt">stable</span> Yb ultrafast ring <span class="hlt">oscillator</span> utilizing a new method of passive mode-locking. The laser is using all-fiber architecture which makes it insensitive to environmental factors, like temperature, humidity, vibrations, and shocks. The new method of mode-locking is utilizing crossed bandpass transmittance filters in ring architecture to discriminate against CW lasing. Broadband pulse evolves from cavity noise under amplification, after passing each filter, causing strong spectral broadening. The laser is self-starting. It generates transform limited spectrally flat pulses of 1 - 50 nm width at 6 - 15 MHz repetition rate and pulse energy 0.2 - 15 nJ at 1010 - 1080 nm CWL.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3910121','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3910121"><span>The Effect of Inhibitory Neuron on the Evolution Model of Higher-Order Coupling Neural <span class="hlt">Oscillator</span> Population</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qi, Yi; Wang, Rubin; Jiao, Xianfa; Du, Ying</p> <p>2014-01-01</p> <p>We proposed a higher-order coupling neural network model including the inhibitory neurons and examined the dynamical evolution of average number density and phase-neural coding under the spontaneous activity and external stimulating condition. The results indicated that increase of inhibitory coupling strength will cause decrease of average number density, whereas increase of excitatory coupling strength will cause increase of <span class="hlt">stable</span> amplitude of average number density. Whether the neural <span class="hlt">oscillator</span> population is able to enter the new synchronous <span class="hlt">oscillation</span> or not is determined by excitatory and inhibitory coupling strength. In the presence of external stimulation, the evolution of the average number density is dependent upon the external stimulation and the coupling term in which the dominator will determine the final evolution. PMID:24516505</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070011688&hterms=number+websites&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnumber%2Bwebsites','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070011688&hterms=number+websites&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnumber%2Bwebsites"><span><span class="hlt">Ultra</span> Reliability Workshop Introduction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shapiro, Andrew A.</p> <p>2006-01-01</p> <p>This plan is the accumulation of substantial work by a large number of individuals. The <span class="hlt">Ultra</span>-Reliability team consists of representatives from each center who have agreed to champion the program and be the focal point for their center. A number of individuals from NASA, government agencies (including the military), universities, industry and non-governmental organizations also contributed significantly to this effort. Most of their names may be found on the <span class="hlt">Ultra</span>-Reliability PBMA website.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22402570-self-oscillating-ab-diblock-copolymer-developed-post-modification-strategy','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22402570-self-oscillating-ab-diblock-copolymer-developed-post-modification-strategy"><span>Self-<span class="hlt">oscillating</span> AB diblock copolymer developed by post modification strategy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ueki, Takeshi, E-mail: ueki@cross.t.u-tokyo.ac.jp, E-mail: ryo@cross.t.u-tokyo.ac.jp; Onoda, Michika; Tamate, Ryota</p> <p></p> <p>We prepared AB diblock copolymer composed of hydrophilic poly(ethylene oxide) segment and self-<span class="hlt">oscillating</span> polymer segment. In the latter segment, ruthenium tris(2,2′-bipyridine) (Ru(bpy){sub 3}), a catalyst of the Belousov-Zhabotinsky reaction, is introduced into the polymer architecture based on N-isopropylacrylamide (NIPAAm). The Ru(bpy){sub 3} was introduced into the polymer segment by two methods; (i) direct random copolymerization (DP) of NIPAAm and Ru(bpy){sub 3} vinyl monomer and (ii) post modification (PM) of Ru(bpy){sub 3} with random copolymer of NIPAAm and N-3-aminopropylmethacrylamide. For both the diblock copolymers, a bistable temperature region (the temperature range; ΔT{sub m}), where the block copolymer self-assembles into micelle atmore » reduced Ru(bpy){sub 3}{sup 2+} state whereas it breaks-up into individual polymer chain at oxidized Ru(bpy){sub 3}{sup 3+} state, monotonically extends as the composition of the Ru(bpy){sub 3} increases. The ΔT{sub m} of the block copolymer prepared by PM is larger than that by DP. The difference in ΔT{sub m} is rationalized from the statistical analysis of the arrangement of the Ru(bpy){sub 3} moiety along the self-<span class="hlt">oscillating</span> segments. By using the PM method, the well-defined AB diblock copolymer having ΔT{sub m} (ca. 25 °C) large enough to cause <span class="hlt">stable</span> self-<span class="hlt">oscillation</span> can be prepared. The periodic structural transition of the diblock copolymer in a dilute solution ([Polymer] = 0.1 wt. %) is closely investigated in terms of the time-resolved dynamic light scattering technique at constant temperature in the bistable region. A macroscopic viscosity <span class="hlt">oscillation</span> of a concentrated polymer solution (15 wt. %) coupled with the periodic microphase separation is also demonstrated.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25928684','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25928684"><span>Brain <span class="hlt">Oscillations</span>, Hypnosis, and Hypnotizability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin</p> <p>2015-01-01</p> <p>This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain <span class="hlt">oscillations</span>. Brain <span class="hlt">oscillations</span> represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) <span class="hlt">oscillations</span>. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These <span class="hlt">oscillations</span> are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) <span class="hlt">oscillations</span> and hypnosis, specifically, that the increases in theta <span class="hlt">oscillations</span> and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CoTPh..64..507W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CoTPh..64..507W"><span>Analysis on Patterns of Globally Coupled Phase <span class="hlt">Oscillators</span> with Attractive and Repulsive Interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Peng-Fei; Ruan, Xiao-Dong; Xu, Zhong-Bin; Fu, Xin</p> <p>2015-11-01</p> <p>The Hong-Strogatz (HS) model of globally coupled phase <span class="hlt">oscillators</span> with attractive and repulsive interactions reflects the fact that each individual (<span class="hlt">oscillator</span>) has its own attitude (attractive or repulsive) to the same environment (mean field). Previous studies on HS model focused mainly on the <span class="hlt">stable</span> states on Ott-Antonsen (OA) manifold. In this paper, the eigenvalues of the Jacobi matrix of each fixed point in HS model are explicitly derived, with the aim to understand the local dynamics around each fixed point. Phase transitions are described according to relative population and coupling strength. Besides, the dynamics off OA manifold is studied. Supported by the National Basic Research Program of China under Grant No. 2015CB057301, the Applied Research Project of Public Welfare Technology of Zhejiang Province under Grant No. 201SC31109 and China Postdoctoral Science Foundation under Grant No. 2014M560483</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28426993','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28426993"><span>A new combined method of <span class="hlt">stable</span> isotope-labeling derivatization-ultrasound-assisted dispersive liquid-liquid microextraction for the determination of neurotransmitters in rat brain microdialysates by <span class="hlt">ultra</span> high performance liquid chromatography tandem mass spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Longfang; Zhao, Xian-En; Zhu, Shuyun; Tao, Yanduo; Ji, Wenhua; Geng, Yanling; Wang, Xiao; Chen, Guang; You, Jinmao</p> <p>2017-06-01</p> <p>In this work, for the first time, a new hyphenated technique of <span class="hlt">stable</span> isotope-labeling derivatization-ultrasound-assisted dispersive liquid-liquid microextraction has been developed for the simultaneous determination of monoamine neurotransmitters (MANTs) and their biosynthesis precursors and metabolites. The developed method was based on <span class="hlt">ultra</span> high performance liquid chromatography tandem mass spectrometry detection using multiple-reaction monitoring mode. A pair of mass spectrometry sensitizing reagents, d 0 -10-methyl-acridone-2-sulfonyl chloride and d 3 -10-methyl-acridone-2-sulfonyl chloride, as <span class="hlt">stable</span> isotope probes was utilized to facilely label neurotransmitters, respectively. The heavy labeled MANTs standards were prepared and used as internal standards for quantification to minimize the matrix effects in mass spectrometry analysis. Low toxic bromobenzene (extractant) and acetonitrile (dispersant) were utilized in microextraction procedure. Under the optimized conditions, good linearity was observed with the limits of detection (S/N>3) and limits of quantification (S/N>10) in the range of 0.002-0.010 and 0.015-0.040nmol/L, respectively. Meanwhile, it also brought acceptable precision (4.2-8.8%, peak area RSDs %) and accuracy (recovery, 96.9-104.1%) results. This method was successfully applied to the simultaneous determination of monoamine neurotransmitters and their biosynthesis precursors and metabolites in rat brain microdialysates of Parkinson's disease and normal rats. This provided a new method for the neurotransmitters related studies in the future. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97c5121C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97c5121C"><span>Direct observation of surface-state thermal <span class="hlt">oscillations</span> in SmB6 <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Casas, Brian; Stern, Alex; Efimkin, Dmitry K.; Fisk, Zachary; Xia, Jing</p> <p>2018-01-01</p> <p>SmB6 is a mixed valence Kondo insulator that exhibits a sharp increase in resistance following an activated behavior that levels off and saturates below 4 K. This behavior can be explained by the proposal of SmB6 representing a new state of matter, a topological Kondo insulator, in which a Kondo gap is developed, and topologically protected surface conduction dominates low-temperature transport. Exploiting its nonlinear dynamics, a tunable SmB6 <span class="hlt">oscillator</span> device was recently demonstrated, where a small dc current generates large <span class="hlt">oscillating</span> voltages at frequencies from a few Hz to hundreds of MHz. This behavior was explained by a theoretical model describing the thermal and electronic dynamics of coupled surface and bulk states. However, a crucial aspect of this model, the predicted temperature <span class="hlt">oscillation</span> in the surface state, has not been experimentally observed to date. This is largely due to the technical difficulty of detecting an <span class="hlt">oscillating</span> temperature of the very thin surface state. Here we report direct measurements of the time-dependent surface-state temperature in SmB6 with a RuO2 microthermometer. Our results agree quantitatively with the theoretically simulated temperature waveform, and hence support the validity of the <span class="hlt">oscillator</span> model, which will provide accurate theoretical guidance for developing future SmB6 <span class="hlt">oscillators</span> at higher frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16290608','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16290608"><span>Mass transfer from an <span class="hlt">oscillating</span> microsphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Jiahua; Zheng, Feng; Laucks, Mary L; Davis, E James</p> <p>2002-05-15</p> <p>The enhancement of mass transfer from single <span class="hlt">oscillating</span> aerocolloidal droplets having initial diameters approximately 40 microm has been measured using electrodynamic levitation to trap and <span class="hlt">oscillate</span> a droplet evaporating in nitrogen gas. The frequency and amplitude of the <span class="hlt">oscillation</span> were controlled by means of ac and dc fields applied to the ring electrodes of the electrodynamic balance (EDB). Elastic light scattering was used to size the droplet. It is shown that the mass transfer process for a colloidal or aerocolloidal particle <span class="hlt">oscillating</span> in the Stokes flow regime is governed by a Peclet number for <span class="hlt">oscillation</span> and a dimensionless <span class="hlt">oscillation</span> parameter that represents the ratio of the diffusion time scale to the <span class="hlt">oscillation</span> time scale. Evaporation rates are reported for stably <span class="hlt">oscillating</span> droplets that are as much as five times the rate for evaporation in a stagnant gas. The enhancement is substantially larger than that predicted by quasi-steady-flow mass transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.446..240M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.446..240M"><span>Viscous driving of global <span class="hlt">oscillations</span> in accretion discs around black holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miranda, Ryan; Horák, Jiří; Lai, Dong</p> <p>2015-01-01</p> <p>We examine the role played by viscosity in the excitation of global <span class="hlt">oscillation</span> modes (both axisymmetric and non-axisymmetric) in accretion discs around black holes using two-dimensional hydrodynamic simulations. The turbulent viscosity is modelled by the α-ansatz, with different equations of state. We consider both discs with transonic radial inflows across the innermost <span class="hlt">stable</span> circular orbit, and stationary discs truncated by a reflecting wall at their inner edge, representing a magnetosphere. In transonic discs, viscosity can excite several types of global <span class="hlt">oscillation</span> modes. These modes are either axisymmetric with frequencies close to multiples of the maximum radial epicyclic frequency κmax, non-axisymmetric with frequencies close to multiples of the innermost <span class="hlt">stable</span> orbit frequency ΩISCO, or hybrid modes whose frequencies are linear combinations of these two frequencies. Small values of the viscosity parameter α primarily produce non-axisymmetric modes, while axisymmetric modes become dominant for large α. The excitation of these modes may be related to an instability of the sonic point, at which the radial infall speed is equal to the sound speed of the gas. In discs with a reflective inner boundary, we explore the effect of viscosity on trapped p modes which are intrinsically overstable due to the corotation resonance effect. The effect of viscosity is either to reduce the growth rates of these modes, or to completely suppress them and excite a new class of higher frequency modes. The latter requires that the dynamic viscosity scales positively with the disc surface density, indicating that it is a result of the classic viscous overstability effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930094609','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930094609"><span>The Question of Spontaneous Wing <span class="hlt">Oscillations</span> : Determination of Critical Velocity Through Flight-<span class="hlt">oscillation</span> Tests</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schlippe, B V</p> <p>1936-01-01</p> <p>Determination of the spontaneous <span class="hlt">oscillations</span> of a wing or tail unit entail many difficulties, both the mathematical determination and the determination by static wing <span class="hlt">oscillation</span> tests being far from successful and flight tests involving very great risks. The present paper gives a method developed at the Junkers Airplane Company by which the critical velocity with respect to spontaneous <span class="hlt">oscillations</span> of increasing amplitude can be ascertained in flight tests without undue risks, the <span class="hlt">oscillation</span> of the surface being obtained in the tests by the application of an external force.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22772313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22772313"><span>Persistent lung <span class="hlt">oscillator</span> response to CO2 after buccal <span class="hlt">oscillator</span> inhibition in the adult frog.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leclère, Renaud; Straus, Christian; Similowski, Thomas; Bodineau, Laurence; Fiamma, Marie-Noëlle</p> <p>2012-08-15</p> <p>The automatic ventilatory drive in amphibians depends on two <span class="hlt">oscillators</span> interacting with each other, the gill/buccal and lung <span class="hlt">oscillators</span>. The lung <span class="hlt">oscillator</span> would be homologous to the mammalian pre-Bötzinger complex and the gill/buccal <span class="hlt">oscillator</span> homologous to the mammalian parafacial respiratory group/retrotrapezoid nucleus (pFRG/RTN). Dysfunction of the pFRG/RTN has been involved in the development of respiratory diseases associated to the loss of CO(2) chemosensitivity such as the congenital central hypoventilation syndrome. Here, on adult in vitro isolated frog brainstem, consequences of the buccal <span class="hlt">oscillator</span> inhibition (by reducing Cl(-)) were evaluated on the respiratory rhythm developed by the lung <span class="hlt">oscillator</span> under hypercapnic challenges. Our results show that under low Cl(-) concentration (i) the buccal <span class="hlt">oscillator</span> is strongly inhibited and the lung burst frequency and amplitude decreased and (ii) it persists a powerful CO(2) chemosensitivity. In conclusion, in frog, the CO(2) chemosensitivity depends on cellular contingent(s) whose the functioning is independent of the concentration of Cl(-) and origin remains unknown. Copyright © 2012 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..93a0501M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..93a0501M"><span>Large deformation of self-<span class="hlt">oscillating</span> polymer gel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maeda, Shingo; Kato, Terukazu; Otsuka, Yuji; Hosoya, Naoki; Cianchetti, Matteo; Laschi, Cecilia</p> <p>2016-01-01</p> <p>A self-<span class="hlt">oscillating</span> gel is a system that generates an autonomous volume <span class="hlt">oscillation</span>. This <span class="hlt">oscillation</span> is powered by the chemical energy of the Belousov-Zhabotinsky (BZ) reaction, which demonstrates metal ion redox <span class="hlt">oscillation</span>. A self-<span class="hlt">oscillating</span> gel is composed of Poly-N -isopropylacrylamide (PNIPAAm) with a metal ion. In this study, we found that the displacement of the volume <span class="hlt">oscillation</span> in a self-<span class="hlt">oscillating</span> gel could be controlled by its being subjected to a prestraining process. We also revealed the driving mechanism of the self-<span class="hlt">oscillating</span> gel from the point of view of thermodynamics. We observed that the polymer-solvent interaction parameter χ is altered by the redox changes to the metal ion incorporated in the self-<span class="hlt">oscillating</span> gel. The prestraining process leads to changes in χ and changes in enthalpy and entropy when the self-<span class="hlt">oscillating</span> gel is in a reduced and oxidized state. We found that nonprestrained gel samples <span class="hlt">oscillate</span> in a poor solution (χ >0.5 ) and prestrained gel samples <span class="hlt">oscillate</span> in a good solution (χ <0.5 ).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4361031','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4361031"><span>Brain <span class="hlt">Oscillations</span>, Hypnosis, and Hypnotizability</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jensen, Mark P.; Adachi, Tomonori; Hakimian, Shahin</p> <p>2014-01-01</p> <p>In this article, we summarize the state-of-science knowledge regarding the associations between hypnosis and brain <span class="hlt">oscillations</span>. Brain <span class="hlt">oscillations</span> represent the combined electrical activity of neuronal assemblies, and are usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) <span class="hlt">oscillations</span>. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These <span class="hlt">oscillations</span> are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. Here we propose that it is this role that may be the mechanistic link between theta (and perhaps gamma) <span class="hlt">oscillations</span> and hypnosis; specifically that theta <span class="hlt">oscillations</span> may facilitate, and that changes in gamma activity observed with hypnosis may underlie, some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis, and for enhancing response to hypnotic treatments. PMID:25792761</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867691','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867691"><span>Ignitor with <span class="hlt">stable</span> low-energy thermite igniting system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kelly, Michael D.; Munger, Alan C.</p> <p>1991-02-05</p> <p>A <span class="hlt">stable</span> compact low-energy igniting system in an ignitor utilizes two components, an initiating charge and an output charge. The initiating charge is a thermite in <span class="hlt">ultra</span>-fine powder form compacted to 50-70% of theoretical maximum density and disposed in a cavity of a header of the ignitor adjacent to an electrical ignition device, or bridgewire, mounted in the header cavity. The initiating charge is ignitable by operation of the ignition device in a hot-wire mode. The output charge is a thermite in high-density consoladated form compacted to 90-99% of theoretical maximum density and disposed adjacent to the initiating charge on an opposite end thereof from the electrical ignition device and ignitable by the initiating charge. A sleeve is provided for mounting the output charge to the ignitor header with the initiating charge confined therebetween in the cavity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930018122','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930018122"><span>Workshop on Harmonic <span class="hlt">Oscillators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Han, D. (Editor); Kim, Y. S. (Editor); Zachary, W. W. (Editor)</p> <p>1993-01-01</p> <p>Proceedings of a workshop on Harmonic <span class="hlt">Oscillators</span> held at the College Park Campus of the University of Maryland on March 25 - 28, 1992 are presented. The harmonic <span class="hlt">oscillator</span> formalism is playing an important role in many branches of physics. This is the simplest mathematical device which can connect the basic principle of physics with what is observed in the real world. The harmonic <span class="hlt">oscillator</span> is the bridge between pure and applied physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21074502','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21074502"><span>Quantification of acetylcholine, choline, betaine, and dimethylglycine in human plasma and urine using <span class="hlt">stable</span>-isotope dilution <span class="hlt">ultra</span> performance liquid chromatography-tandem mass spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kirsch, Susanne H; Herrmann, Wolfgang; Rabagny, Yannick; Obeid, Rima</p> <p>2010-12-15</p> <p>Disorders in choline metabolism are related to disease conditions. We developed a <span class="hlt">stable</span>-isotope dilution <span class="hlt">ultra</span> performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of acetylcholine (ACh), betaine, choline, and dimethylglycine (DMG). We used this method to measure concentrations of the analytes in plasma and urine in addition to other biological fluids after a protein precipitation by acetonitrile. The detection limits were between 0.35 nmol/L (for ACh in urine) and 0.34 μmol/L (for betaine in urine). ACh concentrations were not detectable in plasma. Intraassay and interassay coefficient of variation (CVs) were all <10.0% in biological fluids, except for DMG in cerebrospinal fluid (CV=12.44%). Mean recoveries in urine pool samples were between 99.2% and 103.9%. The urinary excretion of betaine, choline, and DMG was low, with approximately 50.0% higher excretion of choline in females compared to males. Median urinary excretion of ACh were 3.44 and 3.92 μmol/mol creatinine in males and females, respectively (p=0.689). Plasma betaine concentrations correlated significantly with urinary excretions of betaine (r=0.495, p=0.027) and choline (r=0.502, p=0.024) in females. Plasma choline concentrations correlated significantly with urinary excretion of ACh in males (r=0.419, p=0.041) and females (r=0.621, p=0.003). The new method for the simultaneous determination of ACh, betaine, choline, and DMG is sensitive, precise, and fast enough to be used in clinical investigations related to the methylation pathway. Copyright © 2010 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24601942','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24601942"><span>Characterisation of baroreflex sensitivity of recreational <span class="hlt">ultra</span>-endurance athletes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Foulds, Heather J A; Cote, Anita T; Phillips, Aaron A; Charlesworth, Sarah A; Bredin, Shannon S D; Burr, Jamie F; Drury, Chipman Taylor; Ngai, Shirley; Fougere, Renee J; Ivey, Adam C; Warburton, Darren E R</p> <p>2014-01-01</p> <p>Altered autonomic function has been identified following <span class="hlt">ultra</span>-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these <span class="hlt">ultra</span>-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following <span class="hlt">ultra</span>-endurance race participation. Further, we sought to compare baseline measures among <span class="hlt">ultra</span>-endurance athletes and recreationally active controls not participating in the <span class="hlt">ultra</span>-endurance race. Recreational <span class="hlt">ultra</span>-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational <span class="hlt">ultra</span>-endurance athletes and at baseline, for recreationally active controls. Post-race, <span class="hlt">ultra</span>-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p < 0.001] and BRS. Baseline measurements BRS (spectral: 13.96 ± 10.82 ms·mmHg(-1) vs. 11.39 ± 5.33 ms·mmHg(-1)) were similar among recreational <span class="hlt">ultra</span>-endurance athletes and recreationally active controls, though recreational <span class="hlt">ultra</span>-endurance athletes demonstrated greater parasympathetic modulation of some HRV and BPV measures. Recreational <span class="hlt">ultra</span>-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class <span class="hlt">ultra</span>-endurance athletes, though still within normal population ranges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22089655-activation-thermal-stability-ultra-shallow-sup-implants-ge','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22089655-activation-thermal-stability-ultra-shallow-sup-implants-ge"><span>Activation and thermal stability of <span class="hlt">ultra</span>-shallow B{sup +}-implants in Ge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yates, B. R.; Darby, B. L.; Jones, K. S.</p> <p>2012-12-15</p> <p>The activation and thermal stability of <span class="hlt">ultra</span>-shallow B{sup +} implants in crystalline (c-Ge) and preamorphized Ge (PA-Ge) following rapid thermal annealing was investigated using micro Hall effect and ion beam analysis techniques. The residual implanted dose of <span class="hlt">ultra</span>-shallow B{sup +} implants in Ge was characterized using elastic recoil detection and was determined to correlate well with simulations with a dose loss of 23.2%, 21.4%, and 17.6% due to ion backscattering for 2, 4, and 6 keV implants in Ge, respectively. The electrical activation of <span class="hlt">ultra</span>-shallow B{sup +} implants at 2, 4, and 6 keV to fluences ranging from 5.0 Multiplication-Signmore » 10{sup 13} to 5.0 Multiplication-Sign 10{sup 15} cm{sup -2} was studied using micro Hall effect measurements after annealing at 400-600 Degree-Sign C for 60 s. For both c-Ge and PA-Ge, a large fraction of the implanted dose is rendered inactive due to the formation of a presumable B-Ge cluster. The B lattice location in samples annealed at 400 Degree-Sign C for 60 s was characterized by channeling analysis with a 650 keV H{sup +} beam by utilizing the {sup 11}B(p, {alpha})2{alpha} nuclear reaction and confirmed the large fraction of off-lattice B for both c-Ge and PA-Ge. Within the investigated annealing range, no significant change in activation was observed. An increase in the fraction of activated dopant was observed with increasing energy which suggests that the surface proximity and the local point defect environment has a strong impact on B activation in Ge. The results suggest the presence of an inactive B-Ge cluster for <span class="hlt">ultra</span>-shallow implants in both c-Ge and PA-Ge that remains <span class="hlt">stable</span> upon annealing for temperatures up to 600 Degree-Sign C.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25004537','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25004537"><span>Modeling nonlinearities in MEMS <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Agrawal, Deepak K; Woodhouse, Jim; Seshia, Ashwin A</p> <p>2013-08-01</p> <p>We present a mathematical model of a microelectromechanical system (MEMS) <span class="hlt">oscillator</span> that integrates the nonlinearities of the MEMS resonator and the <span class="hlt">oscillator</span> circuitry in a single numerical modeling environment. This is achieved by transforming the conventional nonlinear mechanical model into the electrical domain while simultaneously considering the prominent nonlinearities of the resonator. The proposed nonlinear electrical model is validated by comparing the simulated amplitude-frequency response with measurements on an open-loop electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. Next, the essential nonlinearities in the <span class="hlt">oscillator</span> circuit are investigated and a mathematical model of a MEMS <span class="hlt">oscillator</span> is proposed that integrates the nonlinearities of the resonator. The concept is illustrated for MEMS transimpedance-amplifier- based square-wave and sine-wave <span class="hlt">oscillators</span>. Closed-form expressions of steady-state output power and output frequency are derived for both <span class="hlt">oscillator</span> models and compared with experimental and simulation results, with a good match in the predicted trends in all three cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4068350','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4068350"><span>BLOCKING <span class="hlt">OSCILLATOR</span> DOUBLE PULSE GENERATOR CIRCUIT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Haase, J.A.</p> <p>1961-01-24</p> <p>A double-pulse generator, particuiarly a double-pulse generator comprising a blocking <span class="hlt">oscillator</span> utilizing a feedback circuit to provide means for producing a second pulse within the recovery time of the blocking <span class="hlt">oscillator</span>, is described. The invention utilized a passive network which permits adjustment of the spacing between the original pulses derived from the blocking <span class="hlt">oscillator</span> and further utilizes the original pulses to trigger a circuit from which other pulses are initiated. These other pulses are delayed and then applied to the input of the blocking <span class="hlt">oscillator</span>, with the result that the output from the <span class="hlt">oscillator</span> circuit contains twice the number of pulses originally initiated by the blocking <span class="hlt">oscillator</span> itself.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990028208','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990028208"><span>[Low-Frequency Flow <span class="hlt">Oscillation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bragg, Michael B.</p> <p>1997-01-01</p> <p>The results of the research conducted under this grant are presented in detail in three Master theses, by Heinrich, Balow, and Broeren. Additional analysis of the experimental data can be found in two AIAA Journal articles and two conference papers. Citations for all of the studies' publications can be found in the bibliography which is attached. The objective of Heinrich's study was to document the low-frequency flow <span class="hlt">oscillation</span> on the LRN-1007 airfoil, which had been previously observed at low Reynolds number, to determine its origin, and explore the phenomenon at higher Reynolds number. Heinrich performed detailed flow visualization on the airfoil using surface fluorescent oil and laser-sheet off-body visualization. A large leading-edge separation bubble and trailing-edge separation was identified on the airfoil just prior to the onset of the unsteady stall flow <span class="hlt">oscillation</span>. From the laser-sheet data, the unsteady flow appeared as a massive boundary-layer separation followed by flow reattachment. Hot-wire data were taken in the wake to identify the presence of the flow <span class="hlt">oscillation</span> and the dominant frequency. The <span class="hlt">oscillation</span> was found in the flow from a Reynolds number of 0.3 to 1.3 x 10 exp 6. The Strouhal number based on airfoil projected height was nominally 0.02 and increased slightly with increasing Reynolds number and significantly with increasing airfoil angle of attack. Balow focused his research on the leading-edge separation bubble which was hypothesized to be the origin of the low-frequency <span class="hlt">oscillation</span>. Initially, experimental measurements in the bubble at the onset of the low-frequency <span class="hlt">oscillation</span> were attempted to study the characteristics of the bubble and explain possible relationships to the shear-layer-flapping phenomena. Unfortunately, the bubble proved to be extremely sensitive to the probe interference and it drastically reduced the size of the bubble. These detailed measurements were then abandoned by Balow. However, this led to a series of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.106j3505N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.106j3505N"><span>Highly <span class="hlt">stable</span> thin film transistors using multilayer channel structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nayak, Pradipta K.; Wang, Zhenwei; Anjum, D. H.; Hedhili, M. N.; Alshareef, H. N.</p> <p>2015-03-01</p> <p>We report highly <span class="hlt">stable</span> gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured at room temperature and at 60 °C. A tremendous improvement in gate-bias stress stability was obtained in case of the TFT with multiple layers of ZnO embedded between HfO2 layers compared to the TFT with a single layer of ZnO as the semiconductor. The <span class="hlt">ultra</span>-thin HfO2 layers act as passivation layers, which prevent the adsorption of oxygen and water molecules in the ZnO layer and hence significantly improve the gate-bias stress stability of ZnO TFTs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26764787','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26764787"><span>Chimeralike states in a network of <span class="hlt">oscillators</span> under attractive and repulsive global coupling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mishra, Arindam; Hens, Chittaranjan; Bose, Mridul; Roy, Prodyot K; Dana, Syamal K</p> <p>2015-12-01</p> <p>We report chimeralike states in an ensemble of <span class="hlt">oscillators</span> using a type of global coupling consisting of two components: attractive and repulsive mean-field feedback. We identify the existence of two types of chimeralike states in a bistable Liénard system; in one type, both the coherent and the incoherent populations are in chaotic states (which we refer to as chaos-chaos chimeralike states) and, in another type, the incoherent population is in periodic state while the coherent population has irregular small <span class="hlt">oscillation</span>. We find a metastable state in a parameter regime of the Liénard system where the coherent and noncoherent states migrate in time from one to another subpopulation. The relative size of the incoherent subpopulation, in the chimeralike states, remains almost <span class="hlt">stable</span> with increasing size of the network. The generality of the coupling configuration in the origin of the chimeralike states is tested, using a second example of bistable system, the van der Pol-Duffing <span class="hlt">oscillator</span> where the chimeralike states emerge as weakly chaotic in the coherent subpopulation and chaotic in the incoherent subpopulation. Furthermore, we apply the coupling, in a simplified form, to form a network of the chaotic Rössler system where both the noncoherent and the coherent subpopulations show chaotic dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol3/pdf/CFR-2010-title7-vol3-sec58-144.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol3/pdf/CFR-2010-title7-vol3-sec58-144.pdf"><span>7 CFR 58.144 - Pasteurization or <span class="hlt">ultra</span>-pasteurization.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 7 Agriculture 3 2010-01-01 2010-01-01 false Pasteurization or <span class="hlt">ultra</span>-pasteurization. 58.144 Section... Service 1 Operations and Operating Procedures § 58.144 Pasteurization or <span class="hlt">ultra</span>-pasteurization. When pasteurization or <span class="hlt">ultra</span>-pasteurization is intended or required, or when a product is designated “pasteurized” or...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120006532','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120006532"><span>Programmable <span class="hlt">Oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Quirk, Kevin J.; Patawaran, Ferze D.; Nguyen, Danh H.; Lee, Clement G.; Nguyen, Huy</p> <p>2011-01-01</p> <p>A programmable <span class="hlt">oscillator</span> is a frequency synthesizer with an output phase that tracks an arbitrary function. An offset, phase-locked loop circuit is used in combination with an error control feedback loop to precisely control the output phase of the <span class="hlt">oscillator</span>. To down-convert the received signal, several stages of mixing may be employed with the compensation for the time-base distortion of the carrier occurring at any one of those stages. In the Goldstone Solar System Radar (GSSR), the compensation occurs in the mixing from an intermediate frequency (IF), whose value is dependent on the station and band, to a common IF used in the final stage of down-conversion to baseband. The programmable <span class="hlt">oscillator</span> (PO) is used in the final stage of down-conversion to generate the IF, along with a time-varying phase component that matches the time-base distortion of the carrier, thus removing it from the final down-converted signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.2138W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.2138W"><span>Surface <span class="hlt">oscillation</span> of levitated liquid droplets under microgravity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watanabe, Masahito; Hibiya, Taketoshi; Ozawa, Shumpei; Mizuno, Akitoshi</p> <p>2012-07-01</p> <p>Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the <span class="hlt">oscillating</span> drop method with an electromagnetic levitation (EML) device. Thus, we are now planning the thermophysical properties, the surface tension, viscosity, density and etc., measurements of liquid alloys using the electromagnetic levitator named MSL-EML (Materials Science Laboratory Electromagnetic Levitator), which ahs been developed by the European Space Agency (ESA), installed in the International Space Station (ISS). The surface tension and the viscosity of liquid samples by the <span class="hlt">oscillating</span> drop method are obtained from the surface <span class="hlt">oscillation</span> frequency and damping time of surface <span class="hlt">oscillation</span> respectively. However, analysis of <span class="hlt">oscillating</span> drop method in EML must be improved even in the microgravity conditions, because on the EML conditions the electromagnetic force (EMF) cannot generate the surface <span class="hlt">oscillation</span> with discretely <span class="hlt">oscillation</span> mode. Since under microgravity the levitated droplet shape is completely spherical, the surface <span class="hlt">oscillation</span> frequency with different <span class="hlt">oscillation</span> modes degenerates into the single frequency. Therefore, surface tension will be not affected the EML condition under microgravity, but viscosity will be affected on the different <span class="hlt">oscillation</span> mode of surface <span class="hlt">oscillations</span>. Because dumping time of surface <span class="hlt">oscillation</span> of liquid droplets depends on the <span class="hlt">oscillation</span> modes, the case of surface <span class="hlt">oscillation</span> including multi <span class="hlt">oscillation</span> modes the viscosity values obtained from dumping time will be modified from the correct viscosity. Therefore, we investigate the dumping time of surface <span class="hlt">oscillation</span> of levitated droplets with different <span class="hlt">oscillation</span> modes and also with including multi <span class="hlt">oscillation</span> modes using the electrostatic levitation (ESL) on ground and EML under microgravity conditions by the parabolic flight of airplane. The ESL can discretely generate the surface <span class="hlt">oscillation</span> with different <span class="hlt">oscillation</span> modes by the change of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Chaos..27j4602A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Chaos..27j4602A"><span>Primordial <span class="hlt">oscillations</span> in life: Direct observation of glycolytic <span class="hlt">oscillations</span> in individual HeLa cervical cancer cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amemiya, Takashi; Shibata, Kenichi; Itoh, Yoshihiro; Itoh, Kiminori; Watanabe, Masatoshi; Yamaguchi, Tomohiko</p> <p>2017-10-01</p> <p>We report the first direct observation of glycolytic <span class="hlt">oscillations</span> in HeLa cervical cancer cells, which we regard as primordial <span class="hlt">oscillations</span> preserved in living cells. HeLa cells starved of glucose or both glucose and serum exhibited glycolytic <span class="hlt">oscillations</span> in nicotinamide adenine dinucleotide (NADH), exhibiting asynchronous intercellular behaviors. Also found were spatially homogeneous and inhomogeneous intracellular NADH <span class="hlt">oscillations</span> in the individual cells. Our results demonstrate that starved HeLa cells may be induced to exhibit glycolytic <span class="hlt">oscillations</span> by either high-uptake of glucose or the enhancement of a glycolytic pathway (Crabtree effect or the Warburg effect), or both. Their asynchronous collective behaviors in the <span class="hlt">oscillations</span> were probably due to a weak intercellular coupling. Elucidation of the relationship between the mechanism of glycolytic dynamics in cancer cells and their pathophysiological characteristics remains a challenge in future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060044322&hterms=Photonics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPhotonics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060044322&hterms=Photonics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPhotonics"><span>Recent progress in opto-electronic <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maleki, Lute</p> <p>2005-01-01</p> <p>The optoelectronic <span class="hlt">oscillator</span> (OEO) is a unique device based on photonics techniques to generate highly spectrally pure microwave signals [1]. The development of the OEO was motivated by the need for high performance <span class="hlt">oscillators</span> in the frequency range larger than 10 GHz, where conventional electronic <span class="hlt">oscillators</span> have a number of limitations. These limitations typically stem from the product of fQ, where f is the <span class="hlt">oscillator</span> frequency and Q is the quality factor of the resonator in the <span class="hlt">oscillator</span>. In conventional resonators, whether electromagnetic or piezoelectric, this product is usually a constant. Thus, as the <span class="hlt">oscillator</span> frequency is pushed higher, the quality factor degrades, resulting in degradation of the phase noise of the <span class="hlt">oscillator</span>. An approach to mitigate the problem is to start with a very high quality signal in the 5 to 100 MHz range generated by a quartz <span class="hlt">oscillator</span> and multiply the frequency to achieve the desired microwave signal. Here again, frequency multiplication also results in an increase of the phase noise by a factor of 2010gN, where N is the multiplication factor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6152..700V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6152..700V"><span>Compensating measured intra-wafer ring <span class="hlt">oscillator</span> stage delay with intra-wafer exposure dose corrections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verhaegen, Staf; Nackaerts, Axel; Dusa, Mircea; Carpaij, Rene; Vandenberghe, Geert; Finders, Jo</p> <p>2006-03-01</p> <p>The purpose of this paper is to use measurements on real working devices to derive more information than typically measured by the classic line-width measurement techniques. The first part of the paper will discuss the principle of the measurements with a ring <span class="hlt">oscillator</span>, a circuit used to measure the speed of elementary logic gates. These measurements contribute to the understanding of the exact timing dependencies in circuits, which is of utmost importance for the design and simulation of these circuits. When connecting an odd number of digital inverting stages in a ring, the circuit has no <span class="hlt">stable</span> digital state but acts as an analog <span class="hlt">oscillator</span> with the <span class="hlt">oscillation</span> frequency dependent on the analog propagation delay of the signals through the stages. By varying some conditions during a litho step, the delay change caused by the process condition change can be measured very accurately. The response of the ring <span class="hlt">oscillator</span> delay to exposure dose is measured and presented in this paper together with a comparison of measured line-width values of the poly gate lines. The second part of the paper will focus on improving the intra-wafer variation of the stage delay. A number of ring <span class="hlt">oscillators</span> are put in a design at different slit and scan locations. 200mm wafers are processed with 48 full dies present. From the intra-wafer delay fingerprint and the dose sensitivity of the delay an intra-wafer dose correction, also called a dose recipe, is calculated. This dose recipe is used on the scanner to compensate for effects that are the root cause for the delay profile; including reticle and processing such as track, etch and annealing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27304302','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27304302"><span>Frequency-locked chaotic opto-RF <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thorette, Aurélien; Romanelli, Marco; Brunel, Marc; Vallet, Marc</p> <p>2016-06-15</p> <p>A driven opto-RF <span class="hlt">oscillator</span>, consisting of a dual-frequency laser (DFL) submitted to frequency-shifted feedback, is experimentally and numerically studied in a chaotic regime. Precise control of the reinjection strength and detuning permits isolation of a parameter region of bounded-phase chaos, where the opto-RF <span class="hlt">oscillator</span> is frequency-locked to the master <span class="hlt">oscillator</span>, in spite of chaotic phase and intensity <span class="hlt">oscillations</span>. Robust experimental evidence of this synchronization regime is found, and phase noise spectra allow us to compare phase-locking and bounded-phase chaos regimes. In particular, it is found that the long-term phase stability of the master <span class="hlt">oscillator</span> is well transferred to the opto-RF <span class="hlt">oscillator</span>, even in the chaotic regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873478','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873478"><span>Active-bridge <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wessendorf, Kurt O.</p> <p>2001-01-01</p> <p>An active bridge <span class="hlt">oscillator</span> is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920019509','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920019509"><span>Heat exchanger with <span class="hlt">oscillating</span> flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)</p> <p>1992-01-01</p> <p>Various heat exchange apparatuses are described in which an <span class="hlt">oscillating</span> flow of primary coolant is used to dissipate an incident heat flux. The <span class="hlt">oscillating</span> flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic <span class="hlt">oscillators</span>, or electromagnetic pumps. The <span class="hlt">oscillating</span> fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940016022','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940016022"><span>Heat exchanger with <span class="hlt">oscillating</span> flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)</p> <p>1993-01-01</p> <p>Various heat exchange apparatuses are described in which an <span class="hlt">oscillating</span> flow of primary coolant is used to dissipate an incident heat flux. The <span class="hlt">oscillating</span> flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic <span class="hlt">oscillators</span> or electromagnetic pumps. The <span class="hlt">oscillating</span> fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MART43013R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MART43013R"><span>Polymerization and <span class="hlt">oscillation</span> stuttering in a filamentous model of the subcellular Min <span class="hlt">oscillation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rutenberg, Andrew; Sengupta, Supratim; Sain, Anirban; Derr, Julien</p> <p>2011-03-01</p> <p>We present a computational model of the E. coli Min <span class="hlt">oscillation</span> that involves polymerization of MinD filaments followed by depolymerization stimulated by filament-end zones of MinE. Our stochastic model is fully three-dimensional, and tracks the diffusion and interactions of every MinD and MinE molecule. We recover self-organized Min <span class="hlt">oscillations</span>. We investigate the experimental phenomenon of <span class="hlt">oscillation</span> stuttering, which we relate to the disruption of MinE tip-binding at the filament scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890048882&hterms=astronomia+espacio&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dastronomia%2By%2Bespacio','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890048882&hterms=astronomia+espacio&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dastronomia%2By%2Bespacio"><span><span class="hlt">Oscillations</span> in stellar atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Costa, A.; Ringuelet, A. E.; Fontenla, J. M.</p> <p>1989-01-01</p> <p>Atmospheric excitation and propagation of <span class="hlt">oscillations</span> are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of <span class="hlt">oscillations</span>, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the <span class="hlt">oscillations</span>. The role of the atmosphere in the globar stellar pulsations is thus emphasized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1188...35E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1188...35E"><span>Laser Radiation Pressure Acceleration of Monoenergetic Protons in an <span class="hlt">Ultra</span>-Thin Foil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eliasson, Bengt; Liu, Chuan S.; Shao, Xi; Sagdeev, Roald Z.; Shukla, Padma K.</p> <p>2009-11-01</p> <p>We present theoretical and numerical studies of the acceleration of monoenergetic protons in a double layer formed by the laser irradiation of an <span class="hlt">ultra</span>-thin film. The stability of the foil is investigated by direct Vlasov-Maxwell simulations for different sets of laser-plasma parameters. It is found that the foil is <span class="hlt">stable</span>, due to the trapping of both electrons and ions in the thin laser-plasma interaction region, where the electrons are trapped in a potential well composed of the ponderomo-tive potential of the laser light and the electrostatic potential due to the ions, and the ions are trapped in a potential well composed of the inertial potential in an accelerated frame and the electrostatic potential due to the electrons. The result is a <span class="hlt">stable</span> double layer, where the trapped ions are accelerated to monoenergetic energies up to 100 MeV and beyond, which makes them suitable for medical applications cancer treatment. The underlying physics of trapped and untapped ions in a double layer is also investigated theoretically and numerically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28748930','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28748930"><span>Neuromorphic computing with nanoscale spintronic <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie</p> <p>2017-07-26</p> <p>Neurons in the brain behave as nonlinear <span class="hlt">oscillators</span>, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear <span class="hlt">oscillators</span>. A simple estimation indicates that to fit 10 8 <span class="hlt">oscillators</span> organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each <span class="hlt">oscillator</span> must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting <span class="hlt">oscillators</span>, a proof of concept of neuromorphic computing using nanoscale <span class="hlt">oscillators</span> has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic <span class="hlt">oscillator</span> (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic <span class="hlt">oscillators</span> to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17500780','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17500780"><span>Singular unlocking transition in the Winfree model of coupled <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Quinn, D Dane; Rand, Richard H; Strogatz, Steven H</p> <p>2007-03-01</p> <p>The Winfree model consists of a population of globally coupled phase <span class="hlt">oscillators</span> with randomly distributed natural frequencies. As the coupling strength and the spread of natural frequencies are varied, the various <span class="hlt">stable</span> states of the model can undergo bifurcations, nearly all of which have been characterized previously. The one exception is the unlocking transition, in which the frequency-locked state disappears abruptly as the spread of natural frequencies exceeds a critical width. Viewed as a function of the coupling strength, this critical width defines a bifurcation curve in parameter space. For the special case where the frequency distribution is uniform, earlier work had uncovered a puzzling singularity in this bifurcation curve. Here we seek to understand what causes the singularity. Using the Poincaré-Lindstedt method of perturbation theory, we analyze the locked state and its associated unlocking transition, first for an arbitrary distribution of natural frequencies, and then for discrete systems of N <span class="hlt">oscillators</span>. We confirm that the bifurcation curve becomes singular for a continuum uniform distribution, yet find that it remains well behaved for any finite N , suggesting that the continuum limit is responsible for the singularity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005Natur.437..995B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005Natur.437..995B"><span>Coherent signal amplification in bistable nanomechanical <span class="hlt">oscillators</span> by stochastic resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badzey, Robert L.; Mohanty, Pritiraj</p> <p>2005-10-01</p> <p>Stochastic resonance is a counterintuitive concept: the addition of noise to a noisy system induces coherent amplification of its response. First suggested as a mechanism for the cyclic recurrence of ice ages, stochastic resonance has been seen in a wide variety of macroscopic physical systems: bistable ring lasers, superconducting quantum interference devices (SQUIDs), magnetoelastic ribbons and neurophysiological systems such as the receptors in crickets and crayfish. Although fundamentally important as a mechanism of coherent signal amplification, stochastic resonance has yet to be observed in nanoscale systems. Here we report the observation of stochastic resonance in bistable nanomechanical silicon <span class="hlt">oscillators</span>. Our nanomechanical systems consist of beams that are clamped at each end and driven into transverse <span class="hlt">oscillation</span> with the use of a radiofrequency source. Modulation of the source induces controllable switching of the beams between two <span class="hlt">stable</span>, distinct states. We observe that the addition of white noise causes a marked amplification of the signal strength. Stochastic resonance in nanomechanical systems could have a function in the realization of controllable high-speed nanomechanical memory cells, and paves the way for exploring macroscopic quantum coherence and tunnelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Chaos..26j3112S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Chaos..26j3112S"><span>Discrete breathers in an array of self-excited <span class="hlt">oscillators</span>: Exact solutions and stability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiroky, I. B.; Gendelman, O. V.</p> <p>2016-10-01</p> <p>We consider dynamics of array of coupled self-excited <span class="hlt">oscillators</span>. The model of Franklin bell is adopted as a mechanism for the self-excitation. The model allows derivation of exact analytic solutions for discrete breathers (DBs) and exploration of their stability in the space of parameters. The DB solutions exist for all frequencies in the attenuation zone but lose stability via Neimark-Sacker bifurcation in the vicinity of the bandgap boundary. Besides the well-known DBs with exponential localization, the considered system possesses novel type of solutions—discrete breathers with main frequency in the propagation zone of the chain. In these regimes, the energy irradiation into the chain is balanced by the self-excitation. The amplitude of <span class="hlt">oscillations</span> is maximal at the localization site and then exponentially approaches constant value at infinity. We also derive these solutions in the closed analytic form. They are <span class="hlt">stable</span> in a narrow region of system parameters bounded by Neimark-Sacker and pitchfork bifurcations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27802668','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27802668"><span>Discrete breathers in an array of self-excited <span class="hlt">oscillators</span>: Exact solutions and stability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shiroky, I B; Gendelman, O V</p> <p>2016-10-01</p> <p>We consider dynamics of array of coupled self-excited <span class="hlt">oscillators</span>. The model of Franklin bell is adopted as a mechanism for the self-excitation. The model allows derivation of exact analytic solutions for discrete breathers (DBs) and exploration of their stability in the space of parameters. The DB solutions exist for all frequencies in the attenuation zone but lose stability via Neimark-Sacker bifurcation in the vicinity of the bandgap boundary. Besides the well-known DBs with exponential localization, the considered system possesses novel type of solutions-discrete breathers with main frequency in the propagation zone of the chain. In these regimes, the energy irradiation into the chain is balanced by the self-excitation. The amplitude of <span class="hlt">oscillations</span> is maximal at the localization site and then exponentially approaches constant value at infinity. We also derive these solutions in the closed analytic form. They are <span class="hlt">stable</span> in a narrow region of system parameters bounded by Neimark-Sacker and pitchfork bifurcations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18393486','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18393486"><span><span class="hlt">Ultra</span>-high vacuum surface analysis study of rhodopsin incorporation into supported lipid bilayers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Michel, Roger; Subramaniam, Varuni; McArthur, Sally L; Bondurant, Bruce; D'Ambruoso, Gemma D; Hall, Henry K; Brown, Michael F; Ross, Eric E; Saavedra, S Scott; Castner, David G</p> <p>2008-05-06</p> <p>Planar supported lipid bilayers that are <span class="hlt">stable</span> under ambient atmospheric and <span class="hlt">ultra</span>-high-vacuum conditions were prepared by cross-linking polymerization of bis-sorbylphosphatidylcholine (bis-SorbPC). X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to investigate bilayers that were cross-linked using either redox-initiated radical polymerization or ultraviolet photopolymerization. The redox method yields a more structurally intact bilayer; however, the UV method is more compatible with incorporation of transmembrane proteins. UV polymerization was therefore used to prepare cross-linked bilayers with incorporated bovine rhodopsin, a light-activated, G-protein-coupled receptor (GPCR). A previous study (Subramaniam, V.; Alves, I. D.; Salgado, G. F. J.; Lau, P. W.; Wysocki, R. J.; Salamon, Z.; Tollin, G.; Hruby, V. J.; Brown, M. F.; Saavedra, S. S. J. Am. Chem. Soc. 2005, 127, 5320-5321) showed that rhodopsin retains photoactivity after incorporation into UV-polymerized bis-SorbPC, but did not address how the protein is associated with the bilayer. In this study, we show that rhodopsin is retained in supported bilayers of poly(bis-SorbPC) under <span class="hlt">ultra</span>-high-vacuum conditions, on the basis of the increase in the XPS nitrogen concentration and the presence of characteristic amino acid peaks in the ToF-SIMS data. Angle-resolved XPS data show that the protein is inserted into the bilayer, rather than adsorbed on the bilayer surface. This is the first study to demonstrate the use of <span class="hlt">ultra</span>-high-vacuum techniques for structural studies of supported proteolipid bilayers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PMB....58..127B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PMB....58..127B"><span>Gauging the likelihood of <span class="hlt">stable</span> cavitation from ultrasound contrast agents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bader, Kenneth B.; Holland, Christy K.</p> <p>2013-01-01</p> <p>The mechanical index (MI) was formulated to gauge the likelihood of adverse bioeffects from inertial cavitation. However, the MI formulation did not consider bubble activity from <span class="hlt">stable</span> cavitation. This type of bubble activity can be readily nucleated from ultrasound contrast agents (UCAs) and has the potential to promote beneficial bioeffects. Here, the presence of <span class="hlt">stable</span> cavitation is determined numerically by tracking the onset of subharmonic <span class="hlt">oscillations</span> within a population of bubbles for frequencies up to 7 MHz and peak rarefactional pressures up to 3 MPa. In addition, the acoustic pressure rupture threshold of an UCA population was determined using the Marmottant model. The threshold for subharmonic emissions of optimally sized bubbles was found to be lower than the inertial cavitation threshold for all frequencies studied. The rupture thresholds of optimally sized UCAs were found to be lower than the threshold for subharmonic emissions for either single cycle or steady state acoustic excitations. Because the thresholds of both subharmonic emissions and UCA rupture are linearly dependent on frequency, an index of the form ICAV = Pr/f (where Pr is the peak rarefactional pressure in MPa and f is the frequency in MHz) was derived to gauge the likelihood of subharmonic emissions due to <span class="hlt">stable</span> cavitation activity nucleated from UCAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23221109','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23221109"><span>Gauging the likelihood of <span class="hlt">stable</span> cavitation from ultrasound contrast agents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bader, Kenneth B; Holland, Christy K</p> <p>2013-01-07</p> <p>The mechanical index (MI) was formulated to gauge the likelihood of adverse bioeffects from inertial cavitation. However, the MI formulation did not consider bubble activity from <span class="hlt">stable</span> cavitation. This type of bubble activity can be readily nucleated from ultrasound contrast agents (UCAs) and has the potential to promote beneficial bioeffects. Here, the presence of <span class="hlt">stable</span> cavitation is determined numerically by tracking the onset of subharmonic <span class="hlt">oscillations</span> within a population of bubbles for frequencies up to 7 MHz and peak rarefactional pressures up to 3 MPa. In addition, the acoustic pressure rupture threshold of an UCA population was determined using the Marmottant model. The threshold for subharmonic emissions of optimally sized bubbles was found to be lower than the inertial cavitation threshold for all frequencies studied. The rupture thresholds of optimally sized UCAs were found to be lower than the threshold for subharmonic emissions for either single cycle or steady state acoustic excitations. Because the thresholds of both subharmonic emissions and UCA rupture are linearly dependent on frequency, an index of the form I(CAV) = P(r)/f (where P(r) is the peak rarefactional pressure in MPa and f is the frequency in MHz) was derived to gauge the likelihood of subharmonic emissions due to <span class="hlt">stable</span> cavitation activity nucleated from UCAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467591','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4467591"><span>Gauging the likelihood of <span class="hlt">stable</span> cavitation from ultrasound contrast agents</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bader, Kenneth B; Holland, Christy K</p> <p>2015-01-01</p> <p>The mechanical index (MI) was formulated to gauge the likelihood of adverse bioeffects from inertial cavitation. However, the MI formulation did not consider bubble activity from <span class="hlt">stable</span> cavitation. This type of bubble activity can be readily nucleated from ultrasound contrast agents (UCAs) and has the potential to promote beneficial bioeffects. Here, the presence of <span class="hlt">stable</span> cavitation is determined numerically by tracking the onset of subharmonic <span class="hlt">oscillations</span> within a population of bubbles for frequencies up to 7 MHz and peak rarefactional pressures up to 3 MPa. In addition, the acoustic pressure rupture threshold of an UCA population was determined using the Marmottant model. The threshold for subharmonic emissions of optimally sized bubbles was found to be lower than the inertial cavitation threshold for all frequencies studied. The rupture thresholds of optimally sized UCAs were found to be lower than the threshold for subharmonic emissions for either single cycle or steady state acoustic excitations. Because the thresholds of both subharmonic emissions and UCA rupture are linearly dependent on frequency, an index of the form ICAV = Pr/f (where Pr is the peak rarefactional pressure in MPa and f is the frequency in MHz) was derived to gauge the likelihood of subharmonic emissions due to <span class="hlt">stable</span> cavitation activity nucleated from UCAs. PMID:23221109</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CNSNS..18.2107F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CNSNS..18.2107F"><span>A limit cycle <span class="hlt">oscillator</span> model for cycling mood variations of bipolar disorder patients derived from cellular biochemical reaction equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frank, T. D.</p> <p>2013-08-01</p> <p>We derive a nonlinear limit cycle model for oscillatory mood variations as observed in patients with cycling bipolar disorder. To this end, we consider two signaling pathways leading to the activation of two enzymes that play a key role for cellular and neural processes. We model pathway cross-talk in terms of an inhibitory impact of the first pathway on the second and an excitatory impact of the second on the first. The model also involves a negative feedback loop (inhibitory self-regulation) for the first pathway and a positive feedback loop (excitatory self-regulation) for the second pathway. We demonstrate that due to the cross-talk the biochemical dynamics is described by an <span class="hlt">oscillator</span> equation. Under disease-free conditions the oscillatory system exhibits a <span class="hlt">stable</span> fixed point. The breakdown of the self-inhibition of the first pathway at higher concentration levels is studied by means of a scalar control parameter ξ, where ξ equal to zero refers to intact self-inhibition at all concentration levels. Under certain conditions, <span class="hlt">stable</span> limit cycle solutions emerge at critical parameter values of ξ larger than zero. These <span class="hlt">oscillations</span> mimic pathological cycling mood variations that emerge due to a disease-induced bifurcation. Consequently, our modeling analysis supports the notion of bipolar disorder as a dynamical disease. In addition, our study establishes a connection between mechanistic biochemical modeling of bipolar disorder and phenomenological nonlinear <span class="hlt">oscillator</span> approaches to bipolar disorder suggested in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22586372','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22586372"><span>Divisive normalization and neuronal <span class="hlt">oscillations</span> in a single hierarchical framework of selective visual attention.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montijn, Jorrit Steven; Klink, P Christaan; van Wezel, Richard J A</p> <p>2012-01-01</p> <p>Divisive normalization models of covert attention commonly use spike rate modulations as indicators of the effect of top-down attention. In addition, an increasing number of studies have shown that top-down attention increases the synchronization of neuronal <span class="hlt">oscillations</span> as well, particularly in gamma-band frequencies (25-100 Hz). Although modulations of spike rate and synchronous <span class="hlt">oscillations</span> are not mutually exclusive as mechanisms of attention, there has thus far been little effort to integrate these concepts into a single framework of attention. Here, we aim to provide such a unified framework by expanding the normalization model of attention with a multi-level hierarchical structure and a time dimension; allowing the simulation of a recently reported backward progression of attentional effects along the visual cortical hierarchy. A simple cascade of normalization models simulating different cortical areas is shown to cause signal degradation and a loss of stimulus discriminability over time. To negate this degradation and ensure <span class="hlt">stable</span> neuronal stimulus representations, we incorporate a kind of oscillatory phase entrainment into our model that has previously been proposed as the "communication-through-coherence" (CTC) hypothesis. Our analysis shows that divisive normalization and <span class="hlt">oscillation</span> models can complement each other in a unified account of the neural mechanisms of selective visual attention. The resulting hierarchical normalization and <span class="hlt">oscillation</span> (HNO) model reproduces several additional spatial and temporal aspects of attentional modulation and predicts a latency effect on neuronal responses as a result of cued attention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3343306','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3343306"><span>Divisive Normalization and Neuronal <span class="hlt">Oscillations</span> in a Single Hierarchical Framework of Selective Visual Attention</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Montijn, Jorrit Steven; Klink, P. Christaan; van Wezel, Richard J. A.</p> <p>2012-01-01</p> <p>Divisive normalization models of covert attention commonly use spike rate modulations as indicators of the effect of top-down attention. In addition, an increasing number of studies have shown that top-down attention increases the synchronization of neuronal <span class="hlt">oscillations</span> as well, particularly in gamma-band frequencies (25–100 Hz). Although modulations of spike rate and synchronous <span class="hlt">oscillations</span> are not mutually exclusive as mechanisms of attention, there has thus far been little effort to integrate these concepts into a single framework of attention. Here, we aim to provide such a unified framework by expanding the normalization model of attention with a multi-level hierarchical structure and a time dimension; allowing the simulation of a recently reported backward progression of attentional effects along the visual cortical hierarchy. A simple cascade of normalization models simulating different cortical areas is shown to cause signal degradation and a loss of stimulus discriminability over time. To negate this degradation and ensure <span class="hlt">stable</span> neuronal stimulus representations, we incorporate a kind of oscillatory phase entrainment into our model that has previously been proposed as the “communication-through-coherence” (CTC) hypothesis. Our analysis shows that divisive normalization and <span class="hlt">oscillation</span> models can complement each other in a unified account of the neural mechanisms of selective visual attention. The resulting hierarchical normalization and <span class="hlt">oscillation</span> (HNO) model reproduces several additional spatial and temporal aspects of attentional modulation and predicts a latency effect on neuronal responses as a result of cued attention. PMID:22586372</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9233E..17L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9233E..17L"><span>Multi-beam laser heterodyne measurement with <span class="hlt">ultra</span>-precision for Young modulus based on <span class="hlt">oscillating</span> mirror modulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Y. Chao; Ding, Q.; Gao, Y.; Ran, L. Ling; Yang, J. Ru; Liu, C. Yu; Wang, C. Hui; Sun, J. Feng</p> <p>2014-07-01</p> <p>This paper proposes a novel method of multi-beam laser heterodyne measurement for Young modulus. Based on Doppler effect and heterodyne technology, loaded the information of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the <span class="hlt">oscillating</span> mirror, this method can obtain many values of length variation caused by mass variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain value of Young modulus of the sample by the calculation. This novel method is used to simulate measurement for Young modulus of wire under different mass by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.3%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SSRv..149..199R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SSRv..149..199R"><span>Transverse <span class="hlt">Oscillations</span> of Coronal Loops</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruderman, Michael S.; Erdélyi, Robert</p> <p>2009-12-01</p> <p>On 14 July 1998 TRACE observed transverse <span class="hlt">oscillations</span> of a coronal loop generated by an external disturbance most probably caused by a solar flare. These <span class="hlt">oscillations</span> were interpreted as standing fast kink waves in a magnetic flux tube. Firstly, in this review we embark on the discussion of the theory of waves and <span class="hlt">oscillations</span> in a homogeneous straight magnetic cylinder with the particular emphasis on fast kink waves. Next, we consider the effects of stratification, loop expansion, loop curvature, non-circular cross-section, loop shape and magnetic twist. An important property of observed transverse coronal loop <span class="hlt">oscillations</span> is their fast damping. We briefly review the different mechanisms suggested for explaining the rapid damping phenomenon. After that we concentrate on damping due to resonant absorption. We describe the latest analytical results obtained with the use of thin transition layer approximation, and then compare these results with numerical findings obtained for arbitrary density variation inside the flux tube. Very often collective <span class="hlt">oscillations</span> of an array of coronal magnetic loops are observed. It is natural to start studying this phenomenon from the system of two coronal loops. We describe very recent analytical and numerical results of studying collective <span class="hlt">oscillations</span> of two parallel homogeneous coronal loops. The implication of the theoretical results for coronal seismology is briefly discussed. We describe the estimates of magnetic field magnitude obtained from the observed fundamental frequency of <span class="hlt">oscillations</span>, and the estimates of the coronal scale height obtained using the simultaneous observations of the fundamental frequency and the frequency of the first overtone of kink <span class="hlt">oscillations</span>. In the last part of the review we summarise the most outstanding and acute problems in the theory of the coronal loop transverse <span class="hlt">oscillations</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/673724','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/673724"><span>Combustor <span class="hlt">oscillating</span> pressure stabilization and method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gemmen, R.S.; Richards, G.A.; Yip, M.T.J.; Robey, E.H.; Cully, S.R.; Addis, R.E.</p> <p>1998-08-11</p> <p>High dynamic pressure <span class="hlt">oscillations</span> in hydrocarbon-fueled combustors typically occur when the transport time of the fuel to the flame front is at some fraction of the acoustic period. These <span class="hlt">oscillations</span> are reduced to acceptably lower levels by restructuring or repositioning the flame front in the combustor to increase the transport time. A pilot flame front located upstream of the <span class="hlt">oscillating</span> flame and pulsed at a selected frequency and duration effectively restructures and repositions the <span class="hlt">oscillating</span> flame in the combustor to alter the <span class="hlt">oscillation</span>-causing transport time. 7 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27626226','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27626226"><span>Rhythmic Activity and Individual Variability in Recognition Memory: Theta <span class="hlt">Oscillations</span> Correlate with Performance whereas Alpha <span class="hlt">Oscillations</span> Correlate with ERPs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Yvonne Y; Caplan, Jeremy B</p> <p>2017-01-01</p> <p>During study trials of a recognition memory task, alpha (∼10 Hz) <span class="hlt">oscillations</span> decrease, and concurrently, theta (4-8 Hz) <span class="hlt">oscillations</span> increase when later memory is successful versus unsuccessful (subsequent memory effect). Likewise, at test, reduced alpha and increased theta activity are associated with successful memory (retrieval success effect). Here we take an individual-differences approach to test three hypotheses about theta and alpha <span class="hlt">oscillations</span> in verbal, old/new recognition, measuring the difference in <span class="hlt">oscillations</span> between hit trials and miss trials. First, we test the hypothesis that theta and alpha <span class="hlt">oscillations</span> have a moderately mutually exclusive relationship; but no support for this hypothesis was found. Second, we test the hypothesis that theta <span class="hlt">oscillations</span> explain not only memory effects within participants, but also individual differences. Supporting this prediction, durations of theta (but not alpha) <span class="hlt">oscillations</span> at study and at test correlated significantly with d' across participants. Third, we test the hypothesis that theta and alpha <span class="hlt">oscillations</span> reflect familiarity and recollection processes by comparing <span class="hlt">oscillation</span> measures to ERPs that are implicated in familiarity and recollection. The alpha-<span class="hlt">oscillation</span> effects correlated with some ERP measures, but inversely, suggesting that the actions of alpha <span class="hlt">oscillations</span> on memory processes are distinct from the roles of familiarity- and recollection-linked ERP signals. The theta-<span class="hlt">oscillation</span> measures, despite differentiating hits from misses, did not correlate with any ERP measure; thus, theta <span class="hlt">oscillations</span> may reflect elaborative processes not tapped by recollection-related ERPs. Our findings are consistent with alpha <span class="hlt">oscillations</span> reflecting visual inattention, which can modulate memory, and with theta <span class="hlt">oscillations</span> supporting recognition memory in ways that complement the most commonly studied ERPs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27331147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27331147"><span><span class="hlt">Ultra</span>-wide-field imaging in diabetic retinopathy; an overview.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghasemi Falavarjani, Khalil; Wang, Kang; Khadamy, Joobin; Sadda, Srinivas R</p> <p>2016-06-01</p> <p>To present an overview on <span class="hlt">ultra</span>-wide-field imaging in diabetic retinopathy. A comprehensive search of the pubmed database was performed using the search terms of "<span class="hlt">ultra</span>-wide-field imaging", "<span class="hlt">ultra</span>-wide-field fluorescein angiography" and "diabetic retinopathy". The relevant original articles were reviewed. New advances in <span class="hlt">ultra</span>-wide-field imaging allow for precise measurements of the peripheral retinal lesions. A consistent finding amongst these articles was that <span class="hlt">ultra</span>-wide-field imaging improved detection of peripheral lesion. There was discordance among the studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema. Visualization of the peripheral retina using <span class="hlt">ultra</span>-wide-field imaging improves diagnosis and classification of diabetic retinopathy. Additional studies are needed to better define the association of peripheral diabetic lesions with diabetic macular edema.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.2157R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.2157R"><span>Seasonal Changes in diurnal in-Stream Nitrate Concentration <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rusjan, Simon; Mikoš, Matjaž; Mitja, Brilly; Vidmar, Andrej</p> <p>2010-05-01</p> <p>A variability of seasonal changes in the diurnal in-stream NO3-N concentration <span class="hlt">oscillations</span> was studied through high-frequency measurements of the stream-water's physical, chemical parameters (in-stream NO3-N concentration, water temperature, dissolved oxygen, pH) and hydrometeorological variables (stream discharge, solar radiation) under hydrologically <span class="hlt">stable</span> conditions. The study was carried out in 2006, within the 42 km2 forested Padež stream watershed in the southwestern part of Slovenia, which is characterized by distinctive hydrogeological settings (flysch) and climate conditions (transitional area between the Mediterranean and continental climate). Fine temporal resolution of the data measured at 15 minute intervals enabled the identification of the main driving factors responsible for the seasonal variability in the diurnal pattern of the streamwater NO3-N concentrations vs. seasonal and diurnal behavior of meteorological and other water chemistry constituents. Seasonal variability of the shifts in daily maximum (up to 6 hours) and minimum NO3-N concentrations (between 1 and 3 hours) and changes in the amplitude of the daily NO3-N concentration <span class="hlt">oscillations</span> (in order of 0.1-0.3 mg/l-N) offer supplementary evidence of the in-stream NO3-N processing by photoautotrophs. A wavelet analysis was further used to acquire clear, de-noised NO3-N concentration signals on which models in the form of Fourier series were build, reaching R2 values between 0.73 and 0.94. The models can be used to simulate the in-stream NO3-N <span class="hlt">oscillating</span> signal in order to obtain more accurate assessment of the NO3-N exports from the forested watershed in different seasonal settings, undisturbed by the changing hydrological conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4281653','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4281653"><span>VOLTAGE-CONTROLLED TRANSISTOR <span class="hlt">OSCILLATOR</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Scheele, P.F.</p> <p>1958-09-16</p> <p>This patent relates to transistor <span class="hlt">oscillators</span> and in particular to those transistor <span class="hlt">oscillators</span> whose frequencies vary according to controlling voltages. A principal feature of the disclosed transistor <span class="hlt">oscillator</span> circuit resides in the temperature compensation of the frequency modulating stage by the use of a resistorthermistor network. The resistor-thermistor network components are selected to have the network resistance, which is in series with the modulator transistor emitter circuit, vary with temperature to compensate for variation in the parameters of the transistor due to temperature change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5419332-relationship-between-stratospheric-quasi-biennial-oscillation-tropospheric-southern-oscillation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5419332-relationship-between-stratospheric-quasi-biennial-oscillation-tropospheric-southern-oscillation"><span>On the relationship between the stratospheric quasi-biennial <span class="hlt">oscillation</span> and the tropospheric Southern <span class="hlt">oscillation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Xu, J.S.</p> <p>1992-05-01</p> <p>Two quasi-periodic <span class="hlt">oscillations</span> in the tropical atmosphere with similar <span class="hlt">oscillation</span> period-the stratospheric quasi-biennial and the Southern <span class="hlt">oscillations</span>-and the relationship between these two <span class="hlt">oscillations</span> are examined using the Principal <span class="hlt">Oscillation</span> Pattern (POP) analysis technique. The POP analysis of the equatorial stratospheric dataset provides a compact description of the QBO. The <span class="hlt">oscillation</span> features identified by the POP analysis, namely, the spatial structure, the characteristic times of the <span class="hlt">oscillation</span>, and the asymmetry in downward propagation, are almost identical to those found by earlier studies using more conventional analyses. The simultaneous POP analysis of the equatorial zonal surface wind and sea surface temperature indicatesmore » a well-defined cyclic behavior of the SO. In contrast to the very regular QBO, the SO appears to be much more noisy with intermittent quiet phases. A spectral analysis of the complex POP coefficient time series and the SO index reveals a negligible correlation between the two processes. A POP analysis of the combined equatorial dataset of stratospheric wind, zonal surface wind, and SST also indicates no relation between the QBO and the SO. Two independent modes are identified, one of them completely describing the QBO and the other representing the entire SO. No linear relationship is found between the two modes either in space or in time. It is concluded that the SO and the QBO are two independent processes in the tropical atmosphere with similar time scales. 26 refs., 17 figs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3487384','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3487384"><span>From quiescence to proliferation: Cdk <span class="hlt">oscillations</span> drive the mammalian cell cycle</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gérard, Claude; Goldbeter, Albert</p> <p>2012-01-01</p> <p>We recently proposed a detailed model describing the dynamics of the network of cyclin-dependent kinases (Cdks) driving the mammalian cell cycle (Gérard and Goldbeter, 2009). The model contains four modules, each centered around one cyclin/Cdk complex. Cyclin D/Cdk4–6 and cyclin E/Cdk2 promote progression in G1 and elicit the G1/S transition, respectively; cyclin A/Cdk2 ensures progression in S and the transition S/G2, while the activity of cyclin B/Cdk1 brings about the G2/M transition. This model shows that in the presence of sufficient amounts of growth factor the Cdk network is capable of temporal self-organization in the form of sustained <span class="hlt">oscillations</span>, which correspond to the ordered, sequential activation of the various cyclin/Cdk complexes that control the successive phases of the cell cycle. The results suggest that the switch from cellular quiescence to cell proliferation corresponds to the transition from a <span class="hlt">stable</span> steady state to sustained <span class="hlt">oscillations</span> in the Cdk network. The transition depends on a finely tuned balance between factors that promote or hinder progression in the cell cycle. We show that the transition from quiescence to proliferation can occur in multiple ways that alter this balance. By resorting to bifurcation diagrams, we analyze the mechanism of <span class="hlt">oscillations</span> in the Cdk network. Finally, we show that the complexity of the detailed model can be greatly reduced, without losing its key dynamical properties, by considering a skeleton model for the Cdk network. Using such a skeleton model for the mammalian cell cycle we show that positive feedback (PF) loops enhance the amplitude and the robustness of Cdk <span class="hlt">oscillations</span> with respect to molecular noise. We compare the relative merits of the detailed and skeleton versions of the model for the Cdk network driving the mammalian cell cycle. PMID:23130001</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1022832','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1022832"><span>Analysis of biochemical phase shift <span class="hlt">oscillators</span> by a harmonic balancing technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rapp, P</p> <p>1976-11-25</p> <p>The use of harmonic balancing techniques for theoretically investigating a large class of biochemical phase shift <span class="hlt">oscillators</span> is outlined and the accuracy of this approximate technique for large dimension nonlinear chemical systems is considered. It is concluded that for the equations under study these techniques can be successfully employed to both find periodic solutions and to indicate those cases which can not <span class="hlt">oscillate</span>. The technique is a general one and it is possible to state a step by step procedure for its application. It has a substantial advantage in producing results which are immediately valid for arbitrary dimension. As the accuracy of the method increases with dimension, it complements classical small dimension methods. The results obtained by harmonic balancing analysis are compared with those obtained by studying the local stability properties of the singular points of the differential equation. A general theorem is derived which identifies those special cases where the results of first order harmonic balancing are identical to those of local stability analysis, and a necessary condition for this equivalence is derived. As a concrete example, the n-dimensional Goodwin <span class="hlt">oscillator</span> is considered where p, the Hill coefficient of the feedback metabolite, is equal to three and four. It is shown that for p = 3 or 4 and n less than or equal to 4 the approximation indicates that it is impossible to construct a set of physically permissible reaction constants such that the system possesses a periodic solution. However for n greater than or equal to 5 it is always possible to find a large domain in the reaction constant space giving <span class="hlt">stable</span> <span class="hlt">oscillations</span>. A means of constructing such a parameter set is given. The results obtained here are compared with previously derived results for p = 1 and p = 2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175620','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175620"><span><span class="hlt">Ultra</span>-short ion and neutron pulse production</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Leung, Ka-Ngo; Barletta, William A.; Kwan, Joe W.</p> <p>2006-01-10</p> <p>An ion source has an extraction system configured to produce <span class="hlt">ultra</span>-short ion pulses, i.e. pulses with pulse width of about 1 .mu.s or less, and a neutron source based on the ion source produces correspondingly <span class="hlt">ultra</span>-short neutron pulses. To form a neutron source, a neutron generating target is positioned to receive an accelerated extracted ion beam from the ion source. To produce the <span class="hlt">ultra</span>-short ion or neutron pulses, the apertures in the extraction system of the ion source are suitably sized to prevent ion leakage, the electrodes are suitably spaced, and the extraction voltage is controlled. The ion beam current leaving the source is regulated by applying <span class="hlt">ultra</span>-short voltage pulses of a suitable voltage on the extraction electrode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27857397','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27857397"><span>Record power, <span class="hlt">ultra</span>-broadband supercontinuum source based on highly GeO<sub>2</sub> doped silica fiber.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jain, D; Sidharthan, R; Moselund, P M; Yoo, S; Ho, D; Bang, O</p> <p>2016-11-14</p> <p>We demonstrate highly germania doped fibers for mid-infrared supercontinuum generation. Experiments ensure a highest output power of 1.44 W for a broadest spectrum from 700 nm to 3200 nm and 6.4 W for 800 nm to 2700 nm from these fibers, while being pumped by a broadband Erbium-Ytterbium doped fiber based master <span class="hlt">oscillator</span> power amplifier. The effect of repetition frequency of pump source and length of germania-doped fiber has also been investigated. Further, germania doped fiber has been pumped by conventional supercontinuum source based on silica photonic crystal fiber supercontinuum source. At low power, a considerable broadening of 200-300 nm was observed. Further broadening of spectrum was limited due to limited power of pump source. Our investigations reveal the unexploited potential of germania doped fiber for mid-infrared supercontinuum generation. These measurements ensure the potential of germania based photonic crystal fiber or a step-index fiber supercontinuum source for high power <span class="hlt">ultra</span>-broad band emission being by pumped a 1060 nm or a 1550 nm laser source. To the best of our knowledge, this is the record power, <span class="hlt">ultra</span>-broadband, and all-fiberized supercontinuum light source based on silica and germania fiber ever demonstrated to the date.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27828092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27828092"><span><span class="hlt">Stable</span> multi-wavelength fiber lasers for temperature measurements using an optical loop mirror.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Diaz, Silvia; Socorro, Abian Bentor; Martínez Manuel, Rodolfo; Fernandez, Ruben; Monasterio, Ioseba</p> <p>2016-10-10</p> <p>In this work, two novel <span class="hlt">stable</span> multi-wavelength fiber laser configurations are proposed and demonstrated by using a spool of a single-mode fiber as an optical loop mirror and one or two fiber ring cavities, respectively. The lasers are comprised of fiber Bragg grating reflectors as the <span class="hlt">oscillation</span> wavelength selecting filters. The influence of the length of the spool of fiber on the laser stability both in terms of wavelength and laser output power was investigated. An application for temperature measurement is also shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1260387-baryogenesis-via-particle-antiparticle-oscillations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1260387-baryogenesis-via-particle-antiparticle-oscillations"><span>Baryogenesis via particle-antiparticle <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ipek, Seyda; March-Russell, John</p> <p>2016-06-29</p> <p>CP violation, which is crucial for producing the baryon asymmetry of the Universe, is enhanced in particle-antiparticle <span class="hlt">oscillations</span>. We study particle-antiparticle <span class="hlt">oscillations</span> [of a particle with mass O(100GeV)] with CP violation in the early Universe in the presence of interactions with O(ab-fb) cross sections. We show that if baryon-number-violating interactions exist, a baryon asymmetry can be produced via out-of-equilibrium decays of <span class="hlt">oscillating</span> particles. As a concrete example we study a U(1)R-symmetric, R-parity-violating supersymmetry model with pseudo-Dirac gauginos, which undergo particle-antiparticle <span class="hlt">oscillations</span>. Hence, taking bino to be the lightest U(1) R-symmetric particle, and assuming it decays via baryon-number-violating interactions, we showmore » that bino-antibino <span class="hlt">oscillations</span> can produce the baryon asymmetry of the Universe.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9802K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9802K"><span>Geodynamic environments of <span class="hlt">ultra</span>-slow spreading</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kokhan, Andrey; Dubinin, Evgeny</p> <p>2015-04-01</p> <p><span class="hlt">Ultra</span>-slow spreading is clearly distinguished as an outstanding type of crustal accretion by recent studies. Spreading ridges with <span class="hlt">ultra</span>-slow velocities of extension are studied rather well. But <span class="hlt">ultra</span>-slow spreading is characteristic feature of not only spreading ridges, it can be observed also on convergent and transform plate boundaries. <span class="hlt">Ultra</span>-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on divergent plate boundaries: 1. On spreading ridges with <span class="hlt">ultra</span>-slow spreading, both modern (f.e. Gakkel, South-West Indian, Aden spreading center) and ceased (Labrador spreading center, Aegir ridge); 2. During transition from continental rifting to early stages of oceanic spreading (all spreading ridges during incipient stages of their formation); 3. During incipient stages of formation of spreading ridges on oceanic crust as a result of ridge jumps and reorganization of plate boundaries (f.e. Mathematicians rise and East Pacific rise); 4. During propagation of spreading ridge into the continental crust under influence of hotspot (Aden spreading center and Afar triple junction), under presence of strike-slip faults preceding propagation (possibly, rift zone of California Bay). <span class="hlt">Ultra</span>-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on transform plate boundaries: 1. In transit zones between two "typical" spreading ridges (f.e. Knipovich ridge); 2. In semi strike-slip/extension zones on the oceanic crust (f.e. American-Antarctic ridge); 3. In the zones of local extension in regional strike-slip areas in pull-apart basins along transform boundaries (Cayman trough, pull-apart basins of the southern border of Scotia plate). <span class="hlt">Ultra</span>-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on convergent plate boundaries: 1. During back-arc rifting on the stage of transition into back-arc spreading (central</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25520912','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25520912"><span>Age and <span class="hlt">ultra</span>-marathon performance - 50 to 1,000 km distances from 1969 - 2012.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Romer, Tobias; Rüst, Christoph Alexander; Zingg, Matthias Alexander; Rosemann, Thomas; Knechtle, Beat</p> <p>2014-01-01</p> <p>We investigated age and performance in distance-limited <span class="hlt">ultra</span>-marathons held from 50 km to 1,000 km. Age of peak running speed and running speed of the fastest competitors from 1969 to 2012 in 50 km, 100 km, 200 km and 1,000 km <span class="hlt">ultra</span>-marathons were analyzed using analysis of variance and multi-level regression analyses. The ages of the ten fastest women ever were 40 ± 4 yrs (50 km), 34 ± 7 yrs (100 km), 42 ± 6 yrs (200 km), and 41 ± 5 yrs (1,000 km). The ages were significantly different between 100 km and 200 km and between 100 km and 1,000 km. For men, the ages of the ten fastest ever were 34 ± 6 yrs (50 km), 32 ± 4 yrs (100 km), 44 ± 4 yrs (200 km), and 47 ± 9 yrs (1,000 km). The ages were significantly younger in 50 km compared to 100 km and 200 km and also significantly younger in 100 km compared to 200 km and 1,000 km. The age of the annual ten fastest women decreased in 50 km from 39 ± 8 yrs (1988) to 32 ± 4 yrs (2012) and in men from 35 ± 5 yrs (1977) to 33 ± 5 yrs (2012). In 100 km events, the age of peak running speed of the annual ten fastest women and men remained <span class="hlt">stable</span> at 34.9 ± 3.2 and 34.5 ± 2.5 yrs, respectively. Peak running speed of top ten runners increased in 50 km and 100 km in women (10.6 ± 1.0 to 15.3 ± 0.7 km/h and 7.3 ± 1.5 to 13.0 ± 0.2 km/h, respectively) and men (14.3 ± 1.2 to 17.5 ± 0.6 km/h and 10.2 ± 1.2 to 15.1 ± 0.2 km/h, respectively). In 200 km and 1,000 km, running speed remained unchanged. In summary, the best male 1,000 km <span class="hlt">ultra</span>-marathoners were ~15 yrs older than the best male 100 km <span class="hlt">ultra</span>-marathoners and the best female 1,000 km <span class="hlt">ultra</span>-marathoners were ~7 yrs older than the best female 100 km <span class="hlt">ultra</span>-marathoners. The age of the fastest 50 km <span class="hlt">ultra</span>-marathoners decreased across years whereas it remained unchanged in 100 km <span class="hlt">ultra</span>-marathoners. These findings may help</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013A%26A...560A.107A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013A%26A...560A.107A"><span>Decay-less kink <span class="hlt">oscillations</span> in coronal loops</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anfinogentov, S.; Nisticò, G.; Nakariakov, V. M.</p> <p>2013-12-01</p> <p>Context. Kink <span class="hlt">oscillations</span> of coronal loops in an off-limb active region are detected with the Imaging Assembly Array (AIA) instruments of the Solar Dynamics Observatory (SDO) at 171 Å. Aims: We aim to measure periods and amplitudes of kink <span class="hlt">oscillations</span> of different loops and to determinate the evolution of the <span class="hlt">oscillation</span> phase along the <span class="hlt">oscillating</span> loop. Methods: <span class="hlt">Oscillating</span> coronal loops were visually identified in the field of view of SDO/AIA and STEREO/EUVI-A: the loop length was derived by three-dimensional analysis. Several slits were taken along the loops to assemble time-distance maps. We identified oscillatory patterns and retrieved periods and amplitudes of the <span class="hlt">oscillations</span>. We applied the cross-correlation technique to estimate the phase shift between <span class="hlt">oscillations</span> at different segments of <span class="hlt">oscillating</span> loops. Results: We found that all analysed loops show low-amplitude undamped transverse <span class="hlt">oscillations</span>. <span class="hlt">Oscillation</span> periods of loops in the same active region range from 2.5 to 11 min, and are different for different loops. The displacement amplitude is lower than 1 Mm. The <span class="hlt">oscillation</span> phase is constant along each analysed loop. The spatial structure of the phase of the <span class="hlt">oscillations</span> corresponds to the fundamental standing kink mode. We conclude that the observed behaviour is consistent with the empirical model in terms of a damped harmonic resonator affected by a non-resonant continuously operating external force. A movie is available in electronic form at http://www.aanda.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910075S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910075S"><span>On the astronomical origin of the Hallstatt <span class="hlt">oscillation</span> found in radiocarbon and climate records throughout the Holocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scafetta, Nicola; Milani, Franco; Bianchini, Antonio; Ortolani, Sergio</p> <p>2017-04-01</p> <p>An <span class="hlt">oscillation</span> with a period of about 2100-2500 years, the Hallstatt cycle, is found in cosmogenic radioisotopes (14C and 10Be) and in paleoclimate records throughout the Holocene. This <span class="hlt">oscillation</span> is typically associated with solar variations, but its primary physical origin remains uncertain. Herein we show strong evidences for an astronomical origin of this cycle. Namely, this <span class="hlt">oscillation</span> is coherent to a repeating pattern in the periodic revolution of the planets around the Sun: the major <span class="hlt">stable</span> resonance involving the four Jovian planets - Jupiter, Saturn, Uranus and Neptune - which has a period of about p=2318 yr. Inspired by the Milanković's theory of an astronomical origin of the glacial cycles, we test whether the Hallstatt cycle could derive from the rhythmic variation of the circularity of the solar system disk assuming that this dynamics could eventually modulate the solar wind and, consequently, the incoming cosmic ray flux and/or the interplanetary/cosmic dust concentration around the Earth-Moon system. The orbit of the planetary mass center (PMC) relative to the Sun is used as a proxy. We analyzed how the instantaneous eccentricity vector of this virtual orbit varies from 13,000 B. C. to 17,000 A. D.. We found that it undergoes a kind of pulsations and clearly presents rhythmic contraction and expansion patterns with a 2318 yr period together with a number of already known faster <span class="hlt">oscillations</span> associated to the planetary orbital <span class="hlt">stable</span> resonances. There exists a quasi π/2 phase shift between the 2100-2500 yr <span class="hlt">oscillation</span> found in the 14C record and that of the calculated eccentricity function. Namely, at the Hallstatt-cycle time scale, a larger production of radionucleotide particles occurs while the Sun-PMC orbit evolves from more elliptical shapes (e≈0.598) to more circular ones (e≈0.590), that is while the orbital system is slowly imploding or bursting inward; a smaller production of radionucleotide particles occurs while the Sun-PMC orbit</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3591750','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3591750"><span>Effects of constant immigration on the dynamics and persistence of <span class="hlt">stable</span> and unstable Drosophila populations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dey, Snigdhadip; Joshi, Amitabh</p> <p>2013-01-01</p> <p>Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively <span class="hlt">stable</span> or unstable dynamics. In unstable populations with <span class="hlt">oscillations</span> of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively <span class="hlt">stable</span> populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of <span class="hlt">stable</span> versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Nanot..27t5501M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanot..27t5501M"><span>Sustaining GHz <span class="hlt">oscillation</span> of carbon nanotube based <span class="hlt">oscillators</span> via a MHz frequency excitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Motevalli, Benyamin; Taherifar, Neda; Zhe Liu, Jefferson</p> <p>2016-05-01</p> <p>There have been intensive studies to investigate the properties of gigahertz nano-<span class="hlt">oscillators</span> based on multi-walled carbon nanotubes (MWCNTs). Many of these studies, however, revealed that the unique telescopic translational <span class="hlt">oscillations</span> in such devices would damp quickly due to various energy dissipation mechanisms. This challenge remains the primary obstacle against its practical applications. Herein, we propose a design concept in which a GHz <span class="hlt">oscillation</span> could be re-excited by a MHz mechanical motion. This design involves a triple-walled CNT, in which sliding of the longer inner tube at a MHz frequency can re-excite and sustain a GHz <span class="hlt">oscillation</span> of the shorter middle tube. Our molecular dynamics (MD) simulations prove this design concept at ˜10 nm scale. A mathematical model is developed to explore the feasibility at a larger size scale. As an example, in an oscillatory system with the CNT’s length above 100 nm, the high oscillatory frequency range of 1.8-3.3 GHz could be excited by moving the inner tube at a much lower frequency of 53.4 MHz. This design concept together with the mechanical model could energize the development of GHz nano-<span class="hlt">oscillators</span> in miniaturized electro-mechanical devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvX...8b1005T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvX...8b1005T"><span>Coherent <span class="hlt">Oscillations</span> inside a Quantum Manifold Stabilized by Dissipation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Touzard, S.; Grimm, A.; Leghtas, Z.; Mundhada, S. O.; Reinhold, P.; Axline, C.; Reagor, M.; Chou, K.; Blumoff, J.; Sliwa, K. M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Mirrahimi, M.; Devoret, M. H.</p> <p>2018-04-01</p> <p>Manipulating the state of a logical quantum bit (qubit) usually comes at the expense of exposing it to decoherence. Fault-tolerant quantum computing tackles this problem by manipulating quantum information within a <span class="hlt">stable</span> manifold of a larger Hilbert space, whose symmetries restrict the number of independent errors. The remaining errors do not affect the quantum computation and are correctable after the fact. Here we implement the autonomous stabilization of an encoding manifold spanned by Schrödinger cat states in a superconducting cavity. We show Zeno-driven coherent <span class="hlt">oscillations</span> between these states analogous to the Rabi rotation of a qubit protected against phase flips. Such gates are compatible with quantum error correction and hence are crucial for fault-tolerant logical qubits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SeScT..22...49W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SeScT..22...49W"><span>A method to monitor the quality of <span class="hlt">ultra</span>-thin nitride for trench DRAM with a buried strap structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yung-Hsien; Wang, Chun-Yao; Chang, Ian; Kao, Chien-Kang; Kuo, Chia-Ming; Ku, Alex</p> <p>2007-02-01</p> <p>A new approach to monitor the quality of an <span class="hlt">ultra</span>-thin nitride film has been proposed. The nitride quality is monitored by observing the oxide thickness for the nitride film after wet oxidation since the resistance to oxidation strongly depends on its quality. To obtain a <span class="hlt">stable</span> oxide thickness without interference from extrinsic factors for process monitoring, monitor wafers without dilute HF solution clean are suggested because the native-oxide containing surface is less sensitive to oxygen and therefore forms the nitride film with <span class="hlt">stable</span> quality. In addition, the correlation between variable retention time (VRT) performance of a real dynamic random access memory (DRAM) product and oxide thickness from different nitride process temperatures can be successfully explained and this correlation can also be used to establish the appropriate oxide thickness range for process monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25705810','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25705810"><span>pH-regulated chemical <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Orbán, Miklós; Kurin-Csörgei, Krisztina; Epstein, Irving R</p> <p>2015-03-17</p> <p>The hydrogen ion is arguably the most ubiquitous and important species in chemistry. It also plays a key role in nearly every biological process. In this Account, we discuss systems whose behavior is governed by <span class="hlt">oscillations</span> in the concentration of hydrogen ion. The first chemical <span class="hlt">oscillators</span> driven by changes in pH were developed a quarter century ago. Since then, about two dozen new pH <span class="hlt">oscillators</span>, systems in which the periodic variation in pH is not just an indicator but an essential prerequisite of the oscillatory behavior, have been discovered. Mechanistic understanding of their behavior has grown, and new ideas for their practical application have been proposed and, in some cases, tested. Here we present a catalog of the known pH <span class="hlt">oscillators</span>, divide them into mechanistically based categories based on whether they involve a single oxidant and reductant or an oxidant and a pair of reductants, and describe general mechanisms for these two major classes of systems. We also describe in detail the chemistry of one example from each class, hydrogen peroxide-sulfide and ferricyanide-iodate-sulfite. Finally, we consider actual and potential applications. These include using pH <span class="hlt">oscillators</span> to induce <span class="hlt">oscillation</span> in species that would otherwise be nonoscillatory, creating novel spatial patterns, generating periodic transitions between vesicle and micelle states, stimulating switching between folded and random coil states of DNA, building molecular motors, and designing pulsating drug delivery systems. We point out the importance for future applications of finding a batch pH <span class="hlt">oscillator</span>, one that <span class="hlt">oscillates</span> in a closed system for an extended period of time, and comment on the progress that has been made toward that goal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1234254-impurity-induced-divertor-plasma-oscillations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1234254-impurity-induced-divertor-plasma-oscillations"><span>Impurity-induced divertor plasma <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Smirnov, R. D.; Kukushkin, A. S.; Krasheninnikov, S. I.; ...</p> <p>2016-01-07</p> <p>Two different oscillatory plasma regimes induced by seeding the plasma with high- and low-Z impurities are found for ITER-like divertor plasmas, using computer modeling with the DUSTT/UEDGE and SOLPS4.3 plasma-impurity transport codes. The <span class="hlt">oscillations</span> are characterized by significant variations of the impurity-radiated power and of the peak heat load on the divertor targets. Qualitative analysis of the divertor plasma <span class="hlt">oscillations</span> reveals different mechanisms driving the <span class="hlt">oscillations</span> in the cases of high- and low-Z impurity seeding. The <span class="hlt">oscillations</span> caused by the high-Z impurities are excited near the X-point by an impurity-related instability of the radiation-condensation type, accompanied by parallel impurity ionmore » transport affected by the thermal and plasma friction forces. The driving mechanism of the <span class="hlt">oscillations</span> induced by the low-Z impurities is related to the cross-field transport of the impurity atoms, causing alteration between the high and low plasma temperature regimes in the plasma recycling region near the divertor targets. As a result, the implications of the impurity-induced plasma <span class="hlt">oscillations</span> for divertor operation in the next generation tokamaks are also discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21974653','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21974653"><span>Synchronization in counter-rotating <span class="hlt">oscillators</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bhowmick, Sourav K; Ghosh, Dibakar; Dana, Syamal K</p> <p>2011-09-01</p> <p>An oscillatory system can have opposite senses of rotation, clockwise or anticlockwise. We present a general mathematical description of how to obtain counter-rotating <span class="hlt">oscillators</span> from the definition of a dynamical system. A type of mixed synchronization emerges in counter-rotating <span class="hlt">oscillators</span> under diffusive scalar coupling when complete synchronization and antisynchronization coexist in different state variables. We present numerical examples of limit cycle van der Pol <span class="hlt">oscillator</span> and chaotic Rössler and Lorenz systems. Stability conditions of mixed synchronization are analytically obtained for both Rössler and Lorenz systems. Experimental evidences of counter-rotating limit cycle and chaotic <span class="hlt">oscillators</span> and mixed synchronization are given in electronic circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22757520','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22757520"><span>Exact folded-band chaotic <span class="hlt">oscillator</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Corron, Ned J; Blakely, Jonathan N</p> <p>2012-06-01</p> <p>An exactly solvable chaotic <span class="hlt">oscillator</span> with folded-band dynamics is shown. The <span class="hlt">oscillator</span> is a hybrid dynamical system containing a linear ordinary differential equation and a nonlinear switching condition. Bounded <span class="hlt">oscillations</span> are provably chaotic, and successive waveform maxima yield a one-dimensional piecewise-linear return map with segments of both positive and negative slopes. Continuous-time dynamics exhibit a folded-band topology similar to Rössler's <span class="hlt">oscillator</span>. An exact solution is written as a linear convolution of a fixed basis pulse and a discrete binary sequence, from which an equivalent symbolic dynamics is obtained. The folded-band topology is shown to be dependent on the symbol grammar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800016759','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800016759"><span>Theories of white dwarf <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vanhorn, H. M.</p> <p>1980-01-01</p> <p>The current status of theoretical understanding of the <span class="hlt">oscillations</span> observed in the ZZ Ceti stars and cataclysmic variables is briefly reviewed. Nonradial g-mode <span class="hlt">oscillations</span> appear to provide a satisfactory explanation for the low amplitude variables such as R548, with periods in the range of approximately 200 to 300 seconds, but for the longer period (800 to 1000 seconds) <span class="hlt">oscillators</span>, the situation is still unclear. Rotation may play an important role in this problem, and the effects of both slow and fast rotation upon the mode structure are discussed. In the cataclysmic variables, both accretion and thermonuclear burning may act to excite <span class="hlt">oscillations</span> of the white dwarf.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5575904','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5575904"><span>Neuromorphic computing with nanoscale spintronic <span class="hlt">oscillators</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, M. D.; Grollier, Julie</p> <p>2017-01-01</p> <p>Neurons in the brain behave as non-linear <span class="hlt">oscillators</span>, which develop rhythmic activity and interact to process information1. Taking inspiration from this behavior to realize high density, low power neuromorphic computing will require huge numbers of nanoscale non-linear <span class="hlt">oscillators</span>. Indeed, a simple estimation indicates that, in order to fit a hundred million <span class="hlt">oscillators</span> organized in a two-dimensional array inside a chip the size of a thumb, their lateral dimensions must be smaller than one micrometer. However, despite multiple theoretical proposals2–5, and several candidates such as memristive6 or superconducting7 <span class="hlt">oscillators</span>, there is no proof of concept today of neuromorphic computing with nano-<span class="hlt">oscillators</span>. Indeed, nanoscale devices tend to be noisy and to lack the stability required to process data in a reliable way. Here, we show experimentally that a nanoscale spintronic <span class="hlt">oscillator</span>8,9 can achieve spoken digit recognition with accuracies similar to state of the art neural networks. We pinpoint the regime of magnetization dynamics leading to highest performance. These results, combined with the exceptional ability of these spintronic <span class="hlt">oscillators</span> to interact together, their long lifetime, and low energy consumption, open the path to fast, parallel, on-chip computation based on networks of <span class="hlt">oscillators</span>. PMID:28748930</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1126496','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1126496"><span><span class="hlt">Oscillating</span> fluid power generator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Morris, David C</p> <p>2014-02-25</p> <p>A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure <span class="hlt">oscillates</span> back and forth, generating lift first in one direction then in the opposite direction. This <span class="hlt">oscillating</span> movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other <span class="hlt">oscillating</span> devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given <span class="hlt">oscillation</span> cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960009475','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960009475"><span>A novel photonic <span class="hlt">oscillator</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yao, X. S.; Maleki, L.</p> <p>1995-01-01</p> <p>We report a novel <span class="hlt">oscillator</span> for photonic RF systems. This <span class="hlt">oscillator</span> is capable of generating high-frequency signals up to 70 GHz in both electrical and optical domains and is a special voltage-controlled <span class="hlt">oscillator</span> with an optical output port. It can be used to make a phase-locked loop (PLL) and perform all functions that a PLL is capable of for photonic systems. It can be synchronized to a reference source by means of optical injection locking, electrical injection locking, and PLL. It can also be self-phase locked and self-injection locked to generate a high-stability photonic RF reference. Its applications include high-frequency reference regeneration and distribution, high-gain frequency multiplication, comb-frequecy and square-wave generation, carrier recovery, and clock recovery. We anticipate that such photonic voltage-controlled <span class="hlt">oscillators</span> (VCOs) will be as important to photonic RF systems as electrical VCOs are to electrical RF systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3604044','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3604044"><span>Microfluidic <span class="hlt">oscillators</span> with widely tunable periods</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kim, Sung-Jin; Yokokawa, Ryuji; Takayama, Shuichi</p> <p>2013-01-01</p> <p>We present experiments and theory of a constant flow-driven microfluidic <span class="hlt">oscillator</span> with widely tunable <span class="hlt">oscillation</span> periods. This <span class="hlt">oscillator</span> converts two constant input-flows from a syringe pump into an alternating, periodic output-flow with <span class="hlt">oscillation</span> periods that can be adjusted to between 0.3 s to 4.1 h by tuning an external membrane capacitor. This capacitor allows multiple adjustable periods at a given input flow-rate, thus providing great flexibility in device operation. Also, we show that a sufficiently large external capacitance, relative to the internal capacitance of the microfluidic valve itself, is a critical requirement for <span class="hlt">oscillation</span>. These widely tunable microfluidic <span class="hlt">oscillators</span> are envisioned to be broadly useful for the study of biological rhythms, as on-chip timing sources for microfluidic logic circuits, and other applications that require variation in timed flow switching. PMID:23429765</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034440','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034440"><span>An Unconditionally <span class="hlt">Stable</span>, Positivity-Preserving Splitting Scheme for Nonlinear Black-Scholes Equation with Transaction Costs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guo, Jianqiang; Wang, Wansheng</p> <p>2014-01-01</p> <p>This paper deals with the numerical analysis of nonlinear Black-Scholes equation with transaction costs. An unconditionally <span class="hlt">stable</span> and monotone splitting method, ensuring positive numerical solution and avoiding unstable <span class="hlt">oscillations</span>, is proposed. This numerical method is based on the LOD-Backward Euler method which allows us to solve the discrete equation explicitly. The numerical results for vanilla call option and for European butterfly spread are provided. It turns out that the proposed scheme is efficient and reliable. PMID:24895653</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24895653','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24895653"><span>An unconditionally <span class="hlt">stable</span>, positivity-preserving splitting scheme for nonlinear Black-Scholes equation with transaction costs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Jianqiang; Wang, Wansheng</p> <p>2014-01-01</p> <p>This paper deals with the numerical analysis of nonlinear Black-Scholes equation with transaction costs. An unconditionally <span class="hlt">stable</span> and monotone splitting method, ensuring positive numerical solution and avoiding unstable <span class="hlt">oscillations</span>, is proposed. This numerical method is based on the LOD-Backward Euler method which allows us to solve the discrete equation explicitly. The numerical results for vanilla call option and for European butterfly spread are provided. It turns out that the proposed scheme is efficient and reliable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NaPho...8..119S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NaPho...8..119S"><span>Sub-cycle control of terahertz high-harmonic generation by dynamical Bloch <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schubert, O.; Hohenleutner, M.; Langer, F.; Urbanek, B.; Lange, C.; Huttner, U.; Golde, D.; Meier, T.; Kira, M.; Koch, S. W.; Huber, R.</p> <p>2014-02-01</p> <p>Ultrafast charge transport in strongly biased semiconductors is at the heart of high-speed electronics, electro-optics and fundamental solid-state physics. Intense light pulses in the terahertz spectral range have opened fascinating vistas. Because terahertz photon energies are far below typical electronic interband resonances, a <span class="hlt">stable</span> electromagnetic waveform may serve as a precisely adjustable bias. Novel quantum phenomena have been anticipated for terahertz amplitudes, reaching atomic field strengths. We exploit controlled (multi-)terahertz waveforms with peak fields of 72 MV cm-1 to drive coherent interband polarization combined with dynamical Bloch <span class="hlt">oscillations</span> in semiconducting gallium selenide. These dynamics entail the emission of phase-<span class="hlt">stable</span> high-harmonic transients, covering the entire terahertz-to-visible spectral domain between 0.1 and 675 THz. Quantum interference of different ionization paths of accelerated charge carriers is controlled via the waveform of the driving field and explained by a quantum theory of inter- and intraband dynamics. Our results pave the way towards all-coherent terahertz-rate electronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Nanot..22v5703W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Nanot..22v5703W"><span><span class="hlt">Ultra</span>-small particles of iron oxide as peroxidase for immunohistochemical detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yihang; Song, Mengjie; Xin, Zhuang; Zhang, Xiaoqing; Zhang, Yu; Wang, Chunyu; Li, Suyi; Gu, Ning</p> <p>2011-06-01</p> <p>Dimercaptosuccinic acid (DMSA) modified <span class="hlt">ultra</span>-small particles of iron oxide (USPIO) were synthesized through a two-step process. The first step: oleic acid (OA) capped Fe3O4 (OA-USPIO) were synthesized by a novel oxidation coprecipitation method in H2O/DMSO mixing system, where DMSO acts as an oxidant simultaneously. The second step: OA was replaced by DMSA to obtain water-soluble nanoparticles. The as-synthesized nanoparticles were characterized by TEM, FTIR, TGA, VSM, DLS, EDS and UV-vis. Hydrodynamic sizes and Peroxidase-like catalytic activity of the nanoparticles were investigated. The hydrodynamic sizes of the nanoparticles (around 24.4 nm) were well suited to developing <span class="hlt">stable</span> nanoprobes for bio-detection. The kinetic studies were performed to quantitatively evaluate the catalytic ability of the peroxidase-like nanoparticles. The calculated kinetic parameters indicated that the DMSA-USPIO possesses high catalytic activity. Based on the high activity, immunohistochemical experiments were established: using low-cost nanoparticles as the enzyme instead of expensive HRP, Nimotuzumab was conjugated onto the surface of the nanoparticles to construct a kind of <span class="hlt">ultra</span>-small nanoprobe which was employed to detect epidermal growth factor receptor (EGFR) over-expressed on the membrane of esophageal cancer cell. The proper sizes of the probes and the result of membranous immunohistochemical staining suggest that the probes can be served as a useful diagnostic reagent for bio-detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29063112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29063112"><span>[The mechanism and function of hippocampal neural <span class="hlt">oscillation</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Ning; Xing, Dan-Qin; Sheng, Tao; Lu, Wei</p> <p>2017-10-25</p> <p>Neural <span class="hlt">oscillation</span> is rhythmic or repetitive neural activity in the central nervous system that is usually generated by oscillatory activity of neuronal ensembles, reflecting regular and synchronized activities within these cell populations. According to several oscillatory bands covering frequencies from approximately 0.5 Hz to >100 Hz, neural <span class="hlt">oscillations</span> are usually classified as delta <span class="hlt">oscillation</span> (0.5-3 Hz), theta <span class="hlt">oscillation</span> (4-12 Hz), beta <span class="hlt">oscillation</span> (12-30 Hz), gamma <span class="hlt">oscillation</span> (30-100 Hz) and sharp-wave ripples (>100 Hz ripples superimposed on 0.01-3 Hz sharp waves). Neural <span class="hlt">oscillation</span> in different frequencies can be detected in different brain regions of human and animal during perception, motion and sleep, and plays an essential role in cognition, learning and memory process. In this review, we summarize recent findings on neural <span class="hlt">oscillations</span> in hippocampus, as well as the mechanism and function of hippocampal theta <span class="hlt">oscillation</span>, gamma <span class="hlt">oscillation</span> and sharp-wave ripples. This review may yield new insights into the functions of neural <span class="hlt">oscillation</span> in general.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1374385-observation-quasichanneling-oscillations','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1374385-observation-quasichanneling-oscillations"><span>Observation of Quasichanneling <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wistisen, T. N.; Mikkelsen, R. E.; Uggerhoj, U. I.</p> <p>2017-07-13</p> <p>Here, we report on the first experimental observations of quasichanneling <span class="hlt">oscillations</span>, recently seen in simulations and described theoretically. Although above-barrier particles penetrating a single crystal are generally seen as behaving almost as in an amorphous substance, distinct <span class="hlt">oscillation</span> peaks nevertheless appear for particles in that category. The quasichanneling <span class="hlt">oscillations</span> were observed at SLAC National Accelerator Laboratory by aiming 20.35 GeV positrons and electrons at a thin silicon crystal bent to a radius of R = 0.15 m, exploiting the quasimosaic effect. For electrons, two relatively faint quasichanneling peaks were observed, while for positrons, seven quasichanneling peaks were clearly identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.119b4801W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.119b4801W"><span>Observation of Quasichanneling <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wistisen, T. N.; Mikkelsen, R. E.; Uggerhøj, U. I.; Wienands, U.; Markiewicz, T. W.; Gessner, S.; Hogan, M. J.; Noble, R. J.; Holtzapple, R.; Tucker, S.; Guidi, V.; Mazzolari, A.; Bagli, E.; Bandiera, L.; Sytov, A.; SLAC E-212 Collaboration</p> <p>2017-07-01</p> <p>We report on the first experimental observations of quasichanneling <span class="hlt">oscillations</span>, recently seen in simulations and described theoretically. Although above-barrier particles penetrating a single crystal are generally seen as behaving almost as in an amorphous substance, distinct <span class="hlt">oscillation</span> peaks nevertheless appear for particles in that category. The quasichanneling <span class="hlt">oscillations</span> were observed at SLAC National Accelerator Laboratory by aiming 20.35 GeV positrons and electrons at a thin silicon crystal bent to a radius of R =0.15 m , exploiting the quasimosaic effect. For electrons, two relatively faint quasichanneling peaks were observed, while for positrons, seven quasichanneling peaks were clearly identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvE..85b7201B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvE..85b7201B"><span>Enhancing synchrony in chaotic <span class="hlt">oscillators</span> by dynamic relaying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banerjee, Ranjib; Ghosh, Dibakar; Padmanaban, E.; Ramaswamy, R.; Pecora, L. M.; Dana, Syamal K.</p> <p>2012-02-01</p> <p>In a chain of mutually coupled <span class="hlt">oscillators</span>, the coupling threshold for synchronization between the outermost identical <span class="hlt">oscillators</span> decreases when a type of impurity (in terms of parameter mismatch) is introduced in the inner <span class="hlt">oscillator(s</span>). The outer <span class="hlt">oscillators</span> interact indirectly via dynamic relaying, mediated by the inner <span class="hlt">oscillator(s</span>). We confirm this enhancing of critical coupling in the chaotic regimes of the Lorenz system, in the Rössler system in the absence of coupling delay, and in the Mackey-Glass system with delay coupling. The enhancing effect is experimentally verified in the electronic circuit of Rössler <span class="hlt">oscillators</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930016047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930016047"><span>Calculations of combustion response profiles and <span class="hlt">oscillations</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Priem, Richard J.; Breisacher, Kevin J.</p> <p>1993-01-01</p> <p>The theory and procedures for determining the characteristics of pressure <span class="hlt">oscillations</span> in rocket engines with prescribed burning rate <span class="hlt">oscillations</span> are presented. Pressure and velocity <span class="hlt">oscillations</span> calculated using this procedure are presented for the Space Shuttle Main Engine (SSME) to show the influence of baffles and absorbers on the burning rate <span class="hlt">oscillations</span> required to achieve neutral stability. Results of calculations to determine local combustion responses using detailed physical models for injection, atomization, and vaporization with gas phase <span class="hlt">oscillations</span> in baffled and unbaffled SSME combustors are presented. The contributions of the various physical phenomena occurring in a combustor to <span class="hlt">oscillations</span> in combustion response were determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28380750','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28380750"><span><span class="hlt">Ultra</span>-flat wideband single-pump Raman-enhanced parametric amplification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gordienko, V; Stephens, M F C; El-Taher, A E; Doran, N J</p> <p>2017-03-06</p> <p>We experimentally optimize a single pump fiber optical parametric amplifier in terms of gain spectral bandwidth and gain variation (GV). We find that optimal performance is achieved with the pump tuned to the zero-dispersion wavelength of dispersion <span class="hlt">stable</span> highly nonlinear fiber (HNLF). We demonstrate further improvement of parametric gain bandwidth and GV by decreasing the HNLF length. We discover that Raman and parametric gain spectra produced by the same pump may be merged together to enhance overall gain bandwidth, while keeping GV low. Consequently, we report an <span class="hlt">ultra</span>-flat gain of 9.6 ± 0.5 dB over a range of 111 nm (12.8 THz) on one side of the pump. Additionally, we demonstrate amplification of a 60 Gbit/s QPSK signal tuned over a portion of the available bandwidth with OSNR penalty less than 1 dB for Q<sup>2</sup> below 14 dB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1021484','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1021484"><span>A New Neutrino <span class="hlt">Oscillation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Parke, Stephen J.; /Fermilab</p> <p>2011-07-01</p> <p>Starting in the late 1960s, neutrino detectors began to see signs that neutrinos, now known to come in the flavors electron ({nu}{sub e}), muon ({nu}{sub {mu}}), and tau ({nu}{sub {tau}}), could transform from one flavor to another. The findings implied that neutrinos must have mass, since massless particles travel at the speed of light and their clocks, so to speak, don't tick, thus they cannot change. What has since been discovered is that neutrinos <span class="hlt">oscillate</span> at two distinct scales, 500 km/GeV and 15,000 km/GeV, which are defined by the baseline (L) of the experiment (the distance the neutrino travels) dividedmore » by the neutrino energy (E). Neutrinos of one flavor can <span class="hlt">oscillate</span> into neutrinos of another flavor at both L/E scales, but the amplitude of these <span class="hlt">oscillations</span> is different for the two scales and depends on the initial and final flavor of the neutrinos. The neutrino states that propogate unchanged in time, the mass eigenstates {nu}1, {nu}2, {nu}3, are quantum mechanical mixtures of the electron, muon, and tau neutrino flavors, and the fraction of each flavor in a given mass eigenstate is controlled by three mixing angles and a complex phase. Two of these mixing angles are known with reasonable precision. An upper bound exists for the third angle, called {theta}{sub 13}, which controls the size of the muon neutrino to electron neutrino <span class="hlt">oscillation</span> at an L/E of 500 km/GeV. The phase is completely unknown. The existence of this phase has important implications for the asymmetry between matter and antimatter we observe in the universe today. Experiments around the world have steadily assembled this picture of neutrino <span class="hlt">oscillation</span>, but evidence of muon neutrino to electron neutrino <span class="hlt">oscillation</span> at 500 km/GeV has remained elusive. Now, a paper from the T2K (Tokai to Kamioka) experiment in Japan, reports the first possible observation of muon neutrinos <span class="hlt">oscillating</span> into electron neutrinos at 500 km/GeV. They see 6 candidate signal events, above an expected</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006883','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006883"><span>Multimode and multistate ladder <span class="hlt">oscillator</span> and frequency recognition device</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Aumann, Herbert M. (Inventor)</p> <p>1976-01-01</p> <p>A ladder <span class="hlt">oscillator</span> composed of capacitive and inductive impedances connected together to form a ladder network which has a chosen number N <span class="hlt">oscillation</span> modes at N different frequencies. Each <span class="hlt">oscillation</span> mode is characterized by a unique standing wave voltage pattern along the nodes of the ladder <span class="hlt">oscillator</span>, with the mode in which the ladder <span class="hlt">oscillator</span> is <span class="hlt">oscillating</span> being determinable from the amplitudes or phase of the <span class="hlt">oscillations</span> at the nodes. A logic circuit may be connected to the nodes of the <span class="hlt">oscillator</span> to compare the phases of selected nodes and thereby determine which mode the <span class="hlt">oscillator</span> is <span class="hlt">oscillating</span> in. A ladder <span class="hlt">oscillator</span> composed of passive capacitive and inductive impedances can be utilized as a frequency recognition device, since the passive ladder <span class="hlt">oscillator</span> will display the characteristic standing wave patterns if an input signal impressed upon the ladder <span class="hlt">oscillator</span> is close to one of the mode frequencies of the <span class="hlt">oscillator</span>. A CL ladder <span class="hlt">oscillator</span> having series capacitive impedances and shunt inductive impedances can exhibit sustained and autonomous <span class="hlt">oscillations</span> if active nonlinear devices are connected in parallel with the shunt inductive impedances. The active CL ladder <span class="hlt">oscillator</span> can be synchronized to input frequencies impressed upon the <span class="hlt">oscillator</span>, and will continue to <span class="hlt">oscillate</span> after the input signal has been removed at a mode frequency which is, in general, nearest to the input signal frequency. Autonomous <span class="hlt">oscillations</span> may also be obtained as desired from the active CL ladder <span class="hlt">oscillator</span> at the mode frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...792...41Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...792...41Y"><span><span class="hlt">Oscillations</span> in a Sunspot with Light Bridges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Ding; Nakariakov, Valery M.; Huang, Zhenghua; Li, Bo; Su, Jiangtao; Yan, Yihua; Tan, Baolin</p> <p>2014-09-01</p> <p>The Solar Optical Telescope on board Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 2013 August 31. We analyzed a two-hour Ca II H emission intensity data set and detected strong five-minute <span class="hlt">oscillation</span> power on both LBs and in the inner penumbra. The time-distance plot reveals that the five-minute <span class="hlt">oscillation</span> phase does not vary significantly along the thin bridge, indicating that the <span class="hlt">oscillations</span> are likely to originate from underneath it. The slit taken along the central axis of the wide LB exhibits a standing wave feature. However, at the center of the wide bridge, the five-minute <span class="hlt">oscillation</span> power is found to be stronger than at its sides. Moreover, the time-distance plot across the wide bridge exhibits a herringbone pattern that indicates a counter-stream of two running waves, which originated at the bridge's sides. Thus, the five-minute <span class="hlt">oscillations</span> on the wide bridge also resemble the properties of running penumbral waves. The five-minute <span class="hlt">oscillations</span> are suppressed in the umbra, while the three-minute <span class="hlt">oscillations</span> occupy all three cores of the sunspot's umbra, separated by the LBs. The three-minute <span class="hlt">oscillations</span> were found to be in phase at both sides of the LBs. This may indicate that either LBs do not affect umbral <span class="hlt">oscillations</span>, or that umbral <span class="hlt">oscillations</span> at different umbral cores share the same source. It also indicates that LBs are rather shallow objects situated in the upper part of the umbra. We found that umbral flashes (UFs) follow the life cycles of umbral <span class="hlt">oscillations</span> with much larger amplitudes. They cannot propagate across LBs. UFs dominate the three-minute <span class="hlt">oscillation</span> power within each core; however, they do not disrupt the phase of umbral <span class="hlt">oscillation</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22365204-oscillations-sunspot-light-bridges','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22365204-oscillations-sunspot-light-bridges"><span><span class="hlt">Oscillations</span> in a sunspot with light bridges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yuan, Ding; Su, Jiangtao; Yan, Yihua</p> <p>2014-09-01</p> <p>The Solar Optical Telescope on board Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 2013 August 31. We analyzed a two-hour Ca II H emission intensity data set and detected strong five-minute <span class="hlt">oscillation</span> power on both LBs and in the inner penumbra. The time-distance plot reveals that the five-minute <span class="hlt">oscillation</span> phase does not vary significantly along the thin bridge, indicating that the <span class="hlt">oscillations</span> are likely to originate from underneath it. The slit taken along the central axis of the wide LB exhibits a standing wave feature. However, at the center of the wide bridge, the five-minutemore » <span class="hlt">oscillation</span> power is found to be stronger than at its sides. Moreover, the time-distance plot across the wide bridge exhibits a herringbone pattern that indicates a counter-stream of two running waves, which originated at the bridge's sides. Thus, the five-minute <span class="hlt">oscillations</span> on the wide bridge also resemble the properties of running penumbral waves. The five-minute <span class="hlt">oscillations</span> are suppressed in the umbra, while the three-minute <span class="hlt">oscillations</span> occupy all three cores of the sunspot's umbra, separated by the LBs. The three-minute <span class="hlt">oscillations</span> were found to be in phase at both sides of the LBs. This may indicate that either LBs do not affect umbral <span class="hlt">oscillations</span>, or that umbral <span class="hlt">oscillations</span> at different umbral cores share the same source. It also indicates that LBs are rather shallow objects situated in the upper part of the umbra. We found that umbral flashes (UFs) follow the life cycles of umbral <span class="hlt">oscillations</span> with much larger amplitudes. They cannot propagate across LBs. UFs dominate the three-minute <span class="hlt">oscillation</span> power within each core; however, they do not disrupt the phase of umbral <span class="hlt">oscillation</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1389889','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1389889"><span>Study on <span class="hlt">US/O</span>3 mechanism in p-chlorophenol decomposition</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Xian-wen; Xu, Xin-hua; Shi, Hui-xiang; Wang, Da-hui</p> <p>2005-01-01</p> <p>Study on the effects of sonolysis, ozonolysis and <span class="hlt">US/O</span>3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of <span class="hlt">US/O</span>3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its CODcr under <span class="hlt">US/O</span>3 system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed. PMID:15909343</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AIPC..642...11M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AIPC..642...11M"><span>Neutrino <span class="hlt">Oscillations</span> at Proton Accelerators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michael, Douglas</p> <p>2002-12-01</p> <p>Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino <span class="hlt">oscillations</span>. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex <span class="hlt">oscillation</span> phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino <span class="hlt">oscillations</span> could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of <span class="hlt">oscillation</span> phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino <span class="hlt">oscillation</span> experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1131938','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1131938"><span><span class="hlt">Ultra</span>-Deep Drilling Cost Reduction; Design and Fabrication of an <span class="hlt">Ultra</span>-Deep Drilling Simulator (UDS)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lindstrom, Jason</p> <p>2010-01-31</p> <p><span class="hlt">Ultra</span>-deep drilling, below about 20,000 ft (6,096 m), is extremely expensive and limits the recovery of hydrocarbons at these depths. Unfortunately, rock breakage and cuttings removal under these conditions is not understood. To better understand and thus reduce cost at these conditions an <span class="hlt">ultra</span>-deep single cutter drilling simulator (UDS) capable of drill cutter and mud tests to sustained pressure and temperature of 30,000 psi (207 MPa) and 482 °F (250 °C), respectively, was designed and manufactured at TerraTek, a Schlumberger company, in cooperation with the Department of Energy’s National Energy Technology Laboratory. UDS testing under <span class="hlt">ultra</span>-deep drilling conditions offers anmore » economical alternative to high day rates and can prove or disprove the viability of a particular drilling technique or fluid to provide opportunity for future domestic energy needs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.487...67L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.487...67L"><span>New evidence for "far-field" Holocene sea level <span class="hlt">oscillations</span> and links to global climate records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leonard, N. D.; Welsh, K. J.; Clark, T. R.; Feng, Y.-x.; Pandolfi, J. M.; Zhao, J.-x.</p> <p>2018-04-01</p> <p>Rising sea level in the coming century is of significant concern, yet predicting relative sea level change in response to eustatic sea level variability is complex. Potential analogues are provided by the recent geological past but, until recently, many sea level reconstructions have been limited to millennial scale interpretations due to age uncertainties and paucity in proxy derived records. Here we present a sea level history for the tectonically <span class="hlt">stable</span> "far-field" Great Barrier Reef, Australia, derived from 94 high precision uranium-thorium dates of sub-fossil coral microatolls. Our results provide evidence for at least two periods of relative sea level instability during the Holocene. These sea level <span class="hlt">oscillations</span> are broadly synchronous with Indo-Pacific negative sea surface temperature anomalies, rapid global cooling events and glacial advances. We propose that the pace and magnitude of these <span class="hlt">oscillations</span> are suggestive of eustatic/thermosteric processes operating in conjunction with regional climatic controls.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23834497','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23834497"><span>Development and <span class="hlt">ultra</span>-structure of an <span class="hlt">ultra</span>-thin silicone epidermis of bioengineered alternative tissue.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wessels, Quenton; Pretorius, Etheresia</p> <p>2015-08-01</p> <p>Burn wound care today has a primary objective of temporary or permanent wound closure. Commercially available engineered alternative tissues have become a valuable adjunct to the treatment of burn injuries. Their constituents can be biological, alloplastic or a combination of both. Here the authors describe the aspects of the development of a siloxane epidermis for a collagen-glycosaminoglycan and for nylon-based artificial skin replacement products. A method to fabricate an <span class="hlt">ultra</span>-thin epidermal equivalent is described. Pores, to allow the escape of wound exudate, were punched and a tri-filament nylon mesh or collagen scaffold was imbedded and silicone polymerisation followed at 120°C for 5 minutes. The <span class="hlt">ultra</span>-structure of these bilaminates was assessed through scanning electron microscopy. An <span class="hlt">ultra</span>-thin biomedical grade siloxane film was reliably created through precision coating on a pre-treated polyethylene terephthalate carrier. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MeScT..29b5201G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MeScT..29b5201G"><span>A low-cost, <span class="hlt">ultra</span>-fast and <span class="hlt">ultra</span>-low noise preamplifier for silicon avalanche photodiodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gasmi, Khaled</p> <p>2018-02-01</p> <p>An <span class="hlt">ultra</span>-fast and <span class="hlt">ultra</span>-low noise preamplifier for amplifying the fast and weak electrical signals generated by silicon avalanche photodiodes has been designed and developed. It is characterized by its simplicity, compactness, reliability and low cost of construction. A very wide bandwidth of 300 MHz, a very good linearity from 1 kHz to 280 MHz, an <span class="hlt">ultra</span>-low noise level at the input of only 1.7 nV Hz-1/2 and a very good stability are its key features. The compact size (70 mm  ×  90 mm) and light weight (45 g), as well as its excellent characteristics, make this preamplifier very competitive compared to any commercial preamplifier. The preamplifier, which is a main part of the detection system of a homemade laser remote sensing system, has been successfully tested. In addition, it is versatile and can be used in any optical detection system requiring high speed and very low noise electronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP33C1251V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP33C1251V"><span>Evidence from the Seychelles of Last Interglacial Sea Level <span class="hlt">Oscillations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vyverberg, K.; Dutton, A.; Dechnik, B.; Webster, J.; Zwartz, D.</p> <p>2014-12-01</p> <p>Several studies indicate that sea level <span class="hlt">oscillated</span> during Marine Isotope Stage (MIS) 5e, but the details of these scenarios, including the number of sea level <span class="hlt">oscillations</span>, are still debated. We lack a detailed understanding of the sensitivity of the large polar ice sheets to changes in temperature that could result in eustatic sea level <span class="hlt">oscillations</span>. Because the Seychelles are located far from the margins of the Last Glacial Maximum northern hemisphere ice sheets, they have not been subjected to glacial isostatic adjustment, and have been tectonically <span class="hlt">stable</span> since the Last Interglacial period; therefore, they provide a robust record of eustatic sea level during MIS 5e. All of the outcrops we examined contain unconformities and/or sharp transitions between facies, though the nature of these boundaries varies between sites. In some outcrops we observed a hardground comprising fine-grained, mollusc-rich sediment layer between distinct generations of in situ coralgal framework. In one outcrop, this succession was observed twice, where two generations of reef growth were each capped by a strongly indurated fine-grained, mollusc-rich sediment layer. At the site with the greatest vertical extent of outcrop, there is a marked difference in the taxonomic composition of the coral community above and below an unconformable surface, but the indurated fine-grained, sediment layer observed elsewhere was absent. Most of the other outcrops we studied contained a common succession of facies from in situ reef units overlain by cemented coral rubble. In two dated outcrops, the age of corals above and below the rubble layer are the same age. The hardgrounds and rubble layers may represent ephemeral exposure of the reef units during two drops in sea level. The inference of multiple meter-scale <span class="hlt">oscillations</span> during the MIS 5e highstand indicates a more dynamic cryosphere than the present interglacial, although the climatic threshold for more volatile polar ice sheets is not yet clear.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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