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Sample records for continuous conduction mode

  1. Continuous scanning mode for ptychography

    SciTech Connect

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross J.; Robinson, Ian K.

    2014-01-01

    Here, we outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. Furthermore, the impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  2. Continuous scanning mode for ptychography

    SciTech Connect

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross; Robinson, Ian K.

    2014-10-15

    We outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. The impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  3. Normal modes and continuous spectra

    SciTech Connect

    Balmforth, N.J.; Morrison, P.J.

    1994-12-01

    The authors consider stability problems arising in fluids, plasmas and stellar systems that contain singularities resulting from wave-mean flow or wave-particle resonances. Such resonances lead to singularities in the differential equations determining the normal modes at the so-called critical points or layers. The locations of the singularities are determined by the eigenvalue of the problem, and as a result, the spectrum of eigenvalues forms a continuum. They outline a method to construct the singular eigenfunctions comprising the continuum for a variety of problems.

  4. Dark current studies on a normal-conducting high-brightness very-high-frequency electron gun operating in continuous wave mode

    NASA Astrophysics Data System (ADS)

    Huang, R.; Filippetto, D.; Papadopoulos, C. F.; Qian, H.; Sannibale, F.; Zolotorev, M.

    2015-01-01

    We report on measurements and analysis of a field-emitted electron current in the very-high-frequency (VHF) gun, a room temperature rf gun operating at high field and continuous wave (CW) mode at the Lawrence Berkeley National Laboratory (LBNL). The VHF gun is the core of the Advanced Photo-injector Experiment (APEX) at LBNL, geared toward the development of an injector for driving the next generation of high average power x-ray free electron lasers. High accelerating fields at the cathode are necessary for the high-brightness performance of an electron gun. When coupled with CW operation, such fields can generate a significant amount of field-emitted electrons that can be transported downstream the accelerator forming the so-called "dark current." Elevated levels of a dark current can cause radiation damage, increase the heat load in the downstream cryogenic systems, and ultimately limit the overall performance and reliability of the facility. We performed systematic measurements that allowed us to characterize the field emission from the VHF gun, determine the location of the main emitters, and define an effective strategy to reduce and control the level of dark current at APEX. Furthermore, the energy spectra of isolated sources have been measured. A simple model for energy data analysis was developed that allows one to extract information on the emitter from a single energy distribution measurement.

  5. Phase modulation mode of scanning ion conductance microscopy

    SciTech Connect

    Li, Peng; Zhang, Changlin; Liu, Lianqing E-mail: gli@engr.pitt.edu; Wang, Yuechao; Yang, Yang; Li, Guangyong E-mail: gli@engr.pitt.edu

    2014-08-04

    This Letter reports a phase modulation (PM) mode of scanning ion conductance microscopy. In this mode, an AC current is directly generated by an AC voltage between the electrodes. The portion of the AC current in phase with the AC voltage, which is the current through the resistance path, is modulated by the tip-sample distance. It can be used as the input of feedback control to drive the scanner in Z direction. The PM mode, taking the advantages of both DC mode and traditional AC mode, is less prone to electronic noise and DC drift but maintains high scanning speed. The effectiveness of the PM mode has been proven by experiments.

  6. Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation

    NASA Astrophysics Data System (ADS)

    Firmansyah, Eka; Tomioka, Satoshi; Abe, Seiya; Shoyama, Masahito; Ninomiya, Tamotsu

    This paper proposes a new power-factor-correction (PFC) topology, and explains its operation principle, its control mechanism, related application problems followed by experimental results. In this proposed topology, critical-conduction-mode (CRM) interleaved technique is applied to a bridgeless PFC in order to achieve high efficiency by combining benefits of each topology. This application is targeted toward low to middle power applications that normally employs continuous-conduction-mode boost converter.

  7. Mode dependent lattice thermal conductivity of single layer graphene

    SciTech Connect

    Wei, Zhiyong; Yang, Juekuan; Bi, Kedong; Chen, Yunfei

    2014-10-21

    Molecular dynamics simulation is performed to extract the phonon dispersion and phonon lifetime of single layer graphene. The mode dependent thermal conductivity is calculated from the phonon kinetic theory. The predicted thermal conductivity at room temperature exhibits important quantum effects due to the high Debye temperature of graphene. But the quantum effects are reduced significantly when the simulated temperature is as high as 1000 K. Our calculations show that out-of-plane modes contribute about 41.1% to the total thermal conductivity at room temperature. The relative contribution of out-of-plane modes has a little decrease with the increase of temperature. Contact with substrate can reduce both the total thermal conductivity of graphene and the relative contribution of out-of-plane modes, in agreement with previous experiments and theories. Increasing the coupling strength between graphene and substrate can further reduce the relative contribution of out-of-plane modes. The present investigations also show that the relative contribution of different mode phonons is not sensitive to the grain size of graphene. The obtained phonon relaxation time provides useful insight for understanding the phonon mean free path and the size effects in graphene.

  8. Exercise-induced hypoalgesia - interval versus continuous mode.

    PubMed

    Kodesh, Einat; Weissman-Fogel, Irit

    2014-07-01

    Aerobic exercise at approximately 70% of maximal aerobic capacity moderately reduces pain sensitivity and attenuates pain, even after a single session. If the analgesic effects depend on exercise intensity, then high-intensity interval exercise at 85% of maximal aerobic capacity should further reduce pain. The aim of this study was to explore the exercise-induced analgesic effects of high-intensity interval aerobic exercise and to compare them with the analgesic effects of moderate continuous aerobic exercise. Twenty-nine young untrained healthy males were randomly assigned to aerobic-continuous (70% heart rate reserve (HRR)) and interval (4 × 4 min at 85% HRR and 2 min at 60% HRR between cycles) exercise modes, each lasting 30 min. Psychophysical pain tests, pressure and heat pain thresholds (HPT), and tonic heat pain (THP) were conducted before and after exercise sessions. Repeated measures ANOVA was used for data analysis. HPT increased (p = 0.056) and THP decreased (p = 0.013) following exercise unrelated to exercise type. However, the main time effect (pre-/postexercise) was a trend of increased HPT (45.6 ± 1.9 °C to 46.2 ± 1.8 °C; p = 0.082) and a significant reduction in THP (from 50.7 ± 25 to 45.9 ± 25.4 numeric pain scale; p = 0.043) following interval exercise. No significant change was found for the pressure pain threshold following either exercise type. In conclusion, interval exercise (85% HRR) has analgesic effects on experimental pain perception. This, in addition to its cardiovascular, muscular, and metabolic advantages may promote its inclusion in pain management programs. PMID:24773287

  9. Amplitude Modulation Mode of Scanning Ion Conductance Microscopy.

    PubMed

    Li, Peng; Liu, Lianqing; Yang, Yang; Zhou, Lei; Wang, Dong; Wang, Yuechao; Li, Guangyong

    2015-08-01

    Live-cell imaging at the nanoscale resolution is a hot research topic in the field of life sciences for the direct observation of cellular biological activity. Scanning ion conductance microscopy (SICM) is one of the few effective imaging tools for live-cell imaging at the nanoscale resolution. However, there are various problems in existing scanning modes. The hopping and AC modes suffer from low speed, whereas the DC mode is prone to instability because of the DC drift and external electrical interference. In this article, we propose an amplitude modulation (AM) mode of SICM, which employs an AC voltage to enhance the stability and improve the scanning speed. In this AM mode, we introduce a capacitance compensation method to eliminate capacitance effect and use the amplitude of the AC current component to control the tip movement. Experimental results on polydimethylsiloxane samples verify the validity of the AM mode and demonstrate an improved performance of both speed and stability of this new mode. PMID:25759185

  10. Probe-localized modes in continuous YIG thin films

    NASA Astrophysics Data System (ADS)

    Adur, Rohan; Du, Chunhui; Manuilov, Sergey A.; Zhang, Chi; Pelekhov, Denis V.; Wang, Hailong; Yang, Fengyuan; Hammel, P. Chris

    2014-03-01

    The measurement of damping in precessing ferromagnets is obscured by the excitation of spin waves of different wavelengths due to defects and inhomogeneities in the ferromagnetic material. In order to reduce this parasitic broadening the magnetic mode can be confined to small volumes (nm to μm) either by external fields or by patterning. While nanostructures have shown size-dependent effects such as suppression of inhomogeneity when the size of the nanostructure is sufficiently small, it has been vital to consider the effect of imperfections in lithography that can cause edge damage and hence extrinsic linewidth broadening. In contrast, the dipolar field from a micron-sized probe magnet can be used to localize a mode in a continuous thin film without lithographic modification to the film. This technique of localized mode ferromagnetic resonance force microscopy (FMRFM) has been demonstrated in permalloy at liquid helium temperature. In the present study we demonstrate probe-localized modes in a YIG thin film (t=25nm) measured at room temperature. Using FMRFM we explore the spatial and size dependence of inhomogeneity and damping of a localized mode within a continuous film.

  11. A continuous-mode model of the mode locking in a pump-modulated laser

    NASA Astrophysics Data System (ADS)

    Ogawa, T.; Ema, K.

    1990-12-01

    The active mode-locking process of the multimode laser with an external pump modulation is theoretically investigated in the frequency domain within the framework of the continuous-mode approximation. Intermode interaction and mode-coupling effects, including both AM and FM modulations, are naturally considered in a hierarchical equation of the mode components derived from the multimode Maxwell-Bloch equations. It is reduced to a continuous-mode equation that can be solved analytically in a stationary case, and used to discuss the spectral line shape and the phase dynamics of mode-components as a function of modulation amplitude and detuning of the modulation frequency. We predict a novel oscillation existing below the threshold of the ordinary complete mode-locking: The intensity of the total electric field yields a stable pulse train but its phase varies irregularly in time. This semi-locked state is characterized by a nonlinear chirping, an asymmetric spectrum, and drifting phases of the field mode-components.

  12. Continuous-mode operation of a noiseless linear amplifier

    NASA Astrophysics Data System (ADS)

    Li, Yi; Carvalho, André R. R.; James, Matthew R.

    2016-05-01

    We develop a dynamical model to describe the operation of the nondeterministic noiseless linear amplifier (NLA) in the regime of continuous-mode inputs. We analyze the dynamics conditioned on the detection of photons and show that the amplification gain depends on detection times and on the temporal profile of the input state and the auxiliary single-photon state required by the NLA. We also show that the output amplified state inherits the pulse shape of the ancilla photon.

  13. Tissue lesion created by HIFU in continuous scanning mode

    NASA Astrophysics Data System (ADS)

    Fan, Tingbo; Liu, Zhenbo; Zhang, Dong

    2012-09-01

    The lesion formation was numerically and experimentally investigated by the continuous scanning mode. Simulations were presented based on the combination of Khokhlov-Zabolotskaya-Kuznetov (KZK) equation and bio-heat equation. Measurements were performed on porcine liver tissues using a 1.01 MHz single-element focused transducer at various acoustic powers, confirmed the predicted results. Controlling of the peak temperature and lesion by the scanning speed may be exploited for improvement of efficiency in HIFU therapy.

  14. Continuous spectrum of modes for optical micro-sphere resonators

    NASA Astrophysics Data System (ADS)

    Nooramin, Amir Saman; Shahabadi, Mahmoud

    2016-09-01

    This paper presents an improved modal analysis for the spherical dielectric resonator. This is commonly carried out by assuming an outgoing spherical Hankel function for the region surrounding the dielectric sphere. It will be shown that this assumption is incomplete and cannot lead to the entire spectrum of resonance frequencies. Following an analytical formulation, we prove that, like cylindrical resonators, the only choice for the outer region of the dielectric sphere can be a proper linear combination of an inward and an outward traveling wave. Starting from this formulation, we determine the complete spectrum of the resonance frequencies and the associated mode fields. In this analysis, the continuous spectrum of resonance frequencies is introduced and the properties of radiation modes are studied in detail. The proposed analytical formulation is thereafter employed to calculate the quality factor of the resonator due to radiation and dielectric loss.

  15. Higher Order Mode Coupler Heating in Continuous Wave Operation

    NASA Astrophysics Data System (ADS)

    Solyak, N.; Awida, M.; Hocker, A.; Khabibobulline, T.; Lunin, A.

    Electromagnetic heating due to higher order modes (HOM) propagation is particularly a concern for continuous wave (CW) particle accelerator machines. Power on the order of several watts could flow out of the cavity's HOM ports in CW operations. The upgrade of the Linac Coherent Light Source (LCLS-II) at SLAC requires a major modification of the design of the higher order mode (HOM) antenna and feed through of the conventional ILC elliptical 9-cell cavity in order to utilize it for LCLS-II. The HOM antenna is required to bear higher RF losses, while relatively maintaining the coupling level of the higher order modes. In this paper, we present a detailed analysis of the heating expected in the HOM coupler with a thorough thermal quench study in comparison with the conventional ILC design. We discuss also how the heat will be removed from the cavity through RF cables with specially designed cooling straps. Finally, we report on the latest experimental results of cavity testing in vertical and horizontal cryostats.

  16. Conductance and Absolutely Continuous Spectrum of 1D Samples

    NASA Astrophysics Data System (ADS)

    Bruneau, L.; Jakšić, V.; Last, Y.; Pillet, C.-A.

    2016-06-01

    We characterize the absolutely continuous spectrum of the one-dimensional Schrödinger operators {h = -Δ + v} acting on {ℓ^2(mathbb{Z}_+)} in terms of the limiting behaviour of the Landauer-Büttiker and Thouless conductances of the associated finite samples. The finite sample is defined by restricting h to a finite interval {[1, L] \\cap mathbb{Z}_+} and the conductance refers to the charge current across the sample in the open quantum system obtained by attaching independent electronic reservoirs to the sample ends. Our main result is that the conductances associated to an energy interval {I} are non-vanishing in the limit {L to infty} iff {sp_ac(h) \\cap I neq emptyset}. We also discuss the relationship between this result and the Schrödinger Conjecture (Avila, J Am Math Soc 28:579-616, 2015; Bruneau et al., Commun Math Phys 319:501-513, 2013).

  17. Investigation of continuously traversing microphone system for mode measurement

    NASA Technical Reports Server (NTRS)

    Cicon, D. E.; Sofrin, T. G.; Mathews, D. C.

    1982-01-01

    The continuously Traversing Microphone System consists of a data acquisition and processing method for obtaining the modal coefficients of the discrete, coherent acoustic field in a fan inlet duct. The system would be used in fan rigs or full scale engine installations where present measurement methods, because of the excessive number of microphones and long test times required, are not feasible. The purpose of the investigation reported here was to develop a method for defining modal structure by means of a continuously traversing microphone system and to perform an evaluation of the method, based upon analytical studies and computer simulated tests. A variety of system parameters were examined, and the effects of deviations from ideal were explored. Effects of traverse speed, digitizing rate, run time, roundoff error, calibration errors, and random noise background level were determined. For constant fan operating speed, the sensitivity of the method to normal errors and deviations was determined to be acceptable. Good recovery of mode coefficients was attainable. Fluctuating fan speed conditions received special attention, and it was concluded that by employing suitable time delay procedures, satisfactory information on mode coefficients can be obtained under realistic conditions. A plan for further development involving fan rig tests was prepared.

  18. Modeling and performance analysis of the fractional order quadratic Boost converter in discontinuous conduction mode-discontinuous conduction mode

    NASA Astrophysics Data System (ADS)

    Tan, Cheng; Liang, Zhi-Shan

    2016-03-01

    In this paper, based on the fact that the inductors and capacitors are of fractional order in nature, the four-order mathematical model of the fractional order quadratic Boost converter in type I and type II discontinuous conduction mode (DCM) — DCM is established by using fractional calculus theory. Direct current (DC) analysis is conducted by using the DC equivalent model and the transfer functions are derived from the corresponding alternating current (AC) equivalent model. The DCM-DCM regions of type I and type II are obtained and the relations between the regions and the orders are found. The influence of the orders on the performance of the quadratic Boost converter in DCM-DCM is verified by numerical and circuit simulations. Simulation results demonstrate the correctness of the fractional order model and the efficiency of the proposed theoretical analysis.

  19. Current Source Converters in Discontinuous Conduction Modes of Operation

    NASA Astrophysics Data System (ADS)

    Cuzner, Robert M.

    This work demonstrates that Current Source Rectifier (CSR) pulse-width modulation (PWM) can be successfully modified for discontinuous conduction mode (DCM). DCM is characterized by input current distortion and non-linear input to output voltage ratio. A Dead-Beat Current Injection (DBCI) PWM method is developed that ensures sinusoidal input currents and linear input to output voltage control while in DCM. A method for control analysis is proposed that enables design of the CSR closed loop voltage controller. The proposed method is simulated to show that the desired objectives are achieved at no load and very light load, where the CSR operates in an extreme DCM condition. Experimental results verify performance of the DBCI-PWM method and validate both simulation and analytical tools used to explore the capabilities of the approach. Index Terms---Active buck rectifier, Current source rectifier (CSR), current source PWM rectifier, power conversion, power converter design, power converter analysis, input power quality

  20. Simulation of operation modes of a centrifugal conductive magnetohydrodynamic pump

    NASA Astrophysics Data System (ADS)

    Katsnelson, S. S.; Pozdnyakov, G. A.

    2013-09-01

    A mathematical model of a centrifugal conductive magnetohydrodynamic (MHD) pump that calculates the distributions of velocity, current density, and pressure along the channel is developed. The viscous forces in the original system of MHD equations are taken into account on the basis of the known square law of the drag for a turbulent flow in a pipe, generalized for the case of plane flows in a channel. Dependences of the drag coefficient on the main governing parameters (metal flow rate, current intensity, and intensity of magnetic induction), which provide the agreement of the calculated and experimental data on the pressure at the pump outlet for different operation modes, are obtained. It is shown that these dependences have a universal character and the proposed model can be used to design pumps of this type and to manage their operation in production industry.

  1. New Edge Coherent Mode Providing Continuous Transport in Long-Pulse H-mode Plasmas

    NASA Astrophysics Data System (ADS)

    Wang, H. Q.; Xu, G. S.; Wan, B. N.; Ding, S. Y.; Guo, H. Y.; Shao, L. M.; Liu, S. C.; Xu, X. Q.; Wang, E.; Yan, N.; Naulin, V.; Nielsen, A. H.; Rasmussen, J. Juul; Candy, J.; Bravenec, R.; Sun, Y. W.; Shi, T. H.; Liang, Y. F.; Chen, R.; Zhang, W.; Wang, L.; Chen, L.; Zhao, N.; Li, Y. L.; Liu, Y. L.; Hu, G. H.; Gong, X. Z.

    2014-05-01

    An electrostatic coherent mode near the electron diamagnetic frequency (20-90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Superconducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciprocating probes. The mode propagates in the electron diamagnetic direction in the plasma frame with poloidal wavelength of ˜8 cm. The mode drives a significant outflow of particles and heat as measured directly with the probes, thus greatly facilitating long pulse H-mode sustainment. This mode shows the nature of dissipative trapped electron mode, as evidenced by gyrokinetic turbulence simulations.

  2. Thermal conductance associated with six types of vibration modes in quantum wire modulated with quantum dot

    NASA Astrophysics Data System (ADS)

    Peng, Xiao-Fang; Wang, Xin-Jun; Chen, Li-Qun; Li, Jian-Bo; Zhou, Wu-Xing; Zhang, Gui; Chen, Ke-Qiu

    2014-06-01

    We study the ballistic phonon transport and thermal conductance of six low-lying vibration modes in quantum wire modulated with quantum dot at low temperatures. A comparative analysis is made among the six vibrational modes. The results show that the transmission rates of the six vibrational modes relative to reduced frequency display periodic or quasi-periodic oscillatory behavior. Among the four acoustic modes, the thermal conductance contributed by the torsional mode is the smallest, and the thermal conductances of other acoustic modes have adjacent values. It is also found that the thermal conductance of the optical mode increases from zero monotonously. Moreover, the total thermal conductance in concavity-shaped quantum structure is lower than that in convexity-shaped quantum structure. These thermal conductance values can be adjusted by changing the structural parameters of the quantum dot.

  3. Robust sliding mode continuous control of an IM drive

    SciTech Connect

    Jezernik, K.; Hren, A.; Drevensek, D.

    1995-12-31

    A control approach for robust trajectory tracking of IM servodrive based on the variable structure systems (VSS) is described. A new discrete-time control algorithm has been developed by combining VSS and Lyapunov design. It possesses all the good properties of the sliding mode and avoids the unnecessary discontinuity of the control input, thus eliminating chattering which has been considering as serious obstacles for applications of VSS. A unified control approach for current, torque and motion control based on the discrete-time sliding mode for application in indirect vector control of an IM drive is developed. The sliding mode approach can be applied to the control of an Im drive due to the replacement of the hysteresis controller with widely used PWM technique. All the theoretical issues are verified by experiment. The experimental system consists of a transputer and a microcontroller, thus allowing parallel processing.

  4. The role of thermal conduction in tearing mode theory

    NASA Astrophysics Data System (ADS)

    Connor, J. W.; Ham, C. J.; Hastie, R. J.; Liu, Y. Q.

    2015-06-01

    The role of anisotropic thermal diffusivity in tearing mode stability is analysed in general toroidal geometry following similar techniques to Glasser et al (1975 Phys. Fluids 18 875), although a stronger ordering of the plasma compressibility is required. Resistive layer equations are obtained for a resistive magnetohydrodynamic (MHD) model with anisotropic transport of pressure. A dispersion relation linking the growth rate to the tearing mode stability parameter, Δ‧, characterising the external ideal MHD region, is derived. By using a resistive MHD code modified to include such thermal transport to calculate tearing mode growth rates, this dispersion relation is employed to determine Δ‧ in situations with finite plasma pressure that are stabilised by favourable average curvature when using a simple resistive MHD code. We also demonstrate that the same code can be used to obtain the basis-functions (Ham et al 2012 Plasma Phys. Control. Fusion 54 105014) needed for an alternative approach to calculating Δ‧.

  5. Frequency Management for Electromagnetic Continuous Wave Conductivity Meters.

    PubMed

    Mazurek, Przemyslaw; Putynkowski, Grzegorz

    2016-01-01

    Ground conductivity meters use electromagnetic fields for the mapping of geological variations, like the determination of water amount, depending on ground layers, which is important for the state analysis of embankments. The VLF band is contaminated by numerous natural and artificial electromagnetic interference signals. Prior to the determination of ground conductivity, the meter's working frequency is not possible, due to the variable frequency of the interferences. Frequency management based on the analysis of the selected band using track-before-detect (TBD) algorithms, which allows dynamical frequency changes of the conductivity of the meter transmitting part, is proposed in the paper. Naive maximum value search, spatio-temporal TBD (ST-TBD), Viterbi TBD and a new algorithm that uses combined ST-TBD and Viterbi TBD are compared. Monte Carlo tests are provided for the numerical analysis of the properties for a single interference signal in the considered band, and a new approach based on combined ST-TBD and Viterbi algorithms shows the best performance. The considered algorithms process spectrogram data for the selected band, so DFT (Discrete Fourier Transform) could be applied for the computation of the spectrogram. Real-time properties, related to the latency, are discussed also, and it is shown that TBD algorithms are feasible for real applications. PMID:27070608

  6. Frequency Management for Electromagnetic Continuous Wave Conductivity Meters

    PubMed Central

    Mazurek, Przemyslaw; Putynkowski, Grzegorz

    2016-01-01

    Ground conductivity meters use electromagnetic fields for the mapping of geological variations, like the determination of water amount, depending on ground layers, which is important for the state analysis of embankments. The VLF band is contaminated by numerous natural and artificial electromagnetic interference signals. Prior to the determination of ground conductivity, the meter’s working frequency is not possible, due to the variable frequency of the interferences. Frequency management based on the analysis of the selected band using track-before-detect (TBD) algorithms, which allows dynamical frequency changes of the conductivity of the meter transmitting part, is proposed in the paper. Naive maximum value search, spatio-temporal TBD (ST-TBD), Viterbi TBD and a new algorithm that uses combined ST-TBD and Viterbi TBD are compared. Monte Carlo tests are provided for the numerical analysis of the properties for a single interference signal in the considered band, and a new approach based on combined ST-TBD and Viterbi algorithms shows the best performance. The considered algorithms process spectrogram data for the selected band, so DFT (Discrete Fourier Transform) could be applied for the computation of the spectrogram. Real–time properties, related to the latency, are discussed also, and it is shown that TBD algorithms are feasible for real applications. PMID:27070608

  7. Excitation of Continuous and Discrete Modes in Incompressible Boundary Layers

    NASA Technical Reports Server (NTRS)

    Ashpis, David E.; Reshotko, Eli

    1998-01-01

    This report documents the full details of the condensed journal article by Ashpis & Reshotko (JFM, 1990) entitled "The Vibrating Ribbon Problem Revisited." A revised formal solution of the vibrating ribbon problem of hydrodynamic stability is presented. The initial formulation of Gaster (JFM, 1965) is modified by application of the Briggs method and a careful treatment of the complex double Fourier transform inversions. Expressions are obtained in a natural way for the discrete spectrum as well as for the four branches of the continuous spectra. These correspond to discrete and branch-cut singularities in the complex wave-number plane. The solutions from the continuous spectra decay both upstream and downstream of the ribbon, with the decay in the upstream direction being much more rapid than that in the downstream direction. Comments and clarification of related prior work are made.

  8. Confinement-induced differences between dielectric normal modes and segmental modes of an ion-conducting polymer.

    PubMed

    Kojio, K; Jeon, S; Granick, S

    2002-05-01

    Dielectric measurement in the range 0.1 Hz to 1 MHz were used to study the motions of polymers and ions in an ion-conducting polymer, polypropylene oxide containing small quantities (on the order of 1%) of lithium ions (LiClO(4)), confined as a sandwich of uniform thickness between parallel insulating mica surfaces. In the dielectric loss spectrum, we observed three peaks; they originated from the normal mode of the polymer, segmental mode of the polymer, and ion motions. With decreasing film thickness, the peak frequencies corresponding to the normal mode and ion motion shifted to lower frequencies, indicating retardation due to confinement above 30 nm. This was accompanied by diminished intensity of the dielectric normal-mode relaxation, suggesting that confinement diminished the fluctuations of the end-to-end vector of the chain dipole in the direction between the confining surfaces. On the contrary, the segmental mode was not affected at that thickness. Finally, significant retardation of the segmental mode was observed only for the thinnest film (14 nm). The different dynamical modes of the polymer (segmental and slowest normal modes) respond with different thickness and temperature dependence to confinement. PMID:15010966

  9. Multiple continuous-wave and pulsed modes of a figure-of-eight fibre laser

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Martinez-Rios, A.; Monzon-Hernandez, D.; Salceda-Delgado, G.; Hernandez-Garcia, J. C.; Ibarra-Escamilla, B.; Kuzin, E. A.

    2013-03-01

    We study experimentally a figure-of-eight fibre laser including a polarization-imbalanced nonlinear optical loop mirror and a Mach-Zehnder optical filter formed by two fibre tapers placed in series. Depending on the adjustments of two wave retarders included in the setup, different modes of operation of the laser are found. In continuous-wave mode, tunable single-wavelength operation as well as multiwavelength lasing are observed. For some adjustments, self-pulsing also takes place, although the pulses are very unstable. Finally, for some adjustments a mechanical stimulation (a kick) leads to the onset of passive mode locking. Measurements reveal that the mode-locked pulses actually are noise-like pulses. Both stable fundamental mode locking and second-harmonic mode locking with particular dynamics were obtained. In this work, we analyse how simple wave plate adjustments can lead to such a variety of operational modes of the fibre laser.

  10. Predicting substrate resonance mode frequency shifts using conductive, through-substrate vias

    NASA Astrophysics Data System (ADS)

    Murray, Conal E.; Abraham, D. W.

    2016-02-01

    Through-substrate-vias (TSVs) provide conduction paths to allow for three-dimensional integration of microelectronic structures. It is also known that metallic TSVs can be used to suppress resonance modes within dielectric substrates by altering the propagation of electromagnetic waves. Numerical analyses of transmission through substrates containing metallic TSVs revealed that although resonance modes of the composite structure are shifted to higher frequencies, these frequencies are not solely dictated by the TSV periodicity. Simulations show that hybrid modes are formed through a convolution of the original substrate modes and a long-wavelength mode analogous to that found in a two-dimensional photonic crystal. An analytical formula is proposed that provides a simple relation between the intrinsic substrate mode frequencies and the long-wavelength mode that scales with the ratio of TSV radius to its periodicity.

  11. Braking of tearing mode rotation by ferromagnetic conducting walls in tokamaks

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Richard

    2015-09-01

    An in-depth investigation of the braking of tearing mode rotation in tokamak plasmas via eddy currents induced in external ferromagnetic conducting structures is performed. In general, there is a "forbidden band" of tearing mode rotation frequencies that separates a branch of high-frequency solutions from a branch of low-frequency solutions. When a high-frequency solution crosses the upper boundary of the forbidden band, there is a bifurcation to a low-frequency solution, and vice versa. The bifurcation thresholds predicted by simple torque-balance theory (which takes into account the electromagnetic braking torque acting on the plasma, as well as the plasma viscous restoring torque, but neglects plasma inertia) are found to be essentially the same as those predicted by more complicated time-dependent mode braking theory (which takes inertia into account). Significant ferromagnetism causes otherwise electromagnetically thin conducting structures to become electromagnetically thick and also markedly decreases the critical tearing mode amplitude above which the mode "locks" to the conducting structures (i.e., the high-frequency to low-frequency bifurcation is triggered). On the other hand, if the ferromagnetism becomes too large, then the forbidden band of mode rotation frequencies is suppressed, and the mode frequency consequently varies smoothly and reversibly with the mode amplitude.

  12. Braking of tearing mode rotation by ferromagnetic conducting walls in tokamaks

    SciTech Connect

    Fitzpatrick, Richard

    2015-09-15

    An in-depth investigation of the braking of tearing mode rotation in tokamak plasmas via eddy currents induced in external ferromagnetic conducting structures is performed. In general, there is a “forbidden band” of tearing mode rotation frequencies that separates a branch of high-frequency solutions from a branch of low-frequency solutions. When a high-frequency solution crosses the upper boundary of the forbidden band, there is a bifurcation to a low-frequency solution, and vice versa. The bifurcation thresholds predicted by simple torque-balance theory (which takes into account the electromagnetic braking torque acting on the plasma, as well as the plasma viscous restoring torque, but neglects plasma inertia) are found to be essentially the same as those predicted by more complicated time-dependent mode braking theory (which takes inertia into account). Significant ferromagnetism causes otherwise electromagnetically thin conducting structures to become electromagnetically thick and also markedly decreases the critical tearing mode amplitude above which the mode “locks” to the conducting structures (i.e., the high-frequency to low-frequency bifurcation is triggered). On the other hand, if the ferromagnetism becomes too large, then the forbidden band of mode rotation frequencies is suppressed, and the mode frequency consequently varies smoothly and reversibly with the mode amplitude.

  13. Continuous Locomotion-Mode Identification for Prosthetic Legs Based on Neuromuscular–Mechanical Fusion

    PubMed Central

    Zhang, Fan; Hargrove, Levi J.; Dou, Zhi; Rogers, Daniel R.; Englehart, Kevin B.

    2011-01-01

    In this study, we developed an algorithm based on neuromuscular–mechanical fusion to continuously recognize a variety of locomotion modes performed by patients with transfemoral (TF) amputations. Electromyographic (EMG) signals recorded from gluteal and residual thigh muscles and ground reaction forces/moments measured from the prosthetic pylon were used as inputs to a phase-dependent pattern classifier for continuous locomotion-mode identification. The algorithm was evaluated using data collected from five patients with TF amputations. The results showed that neuromuscular–mechanical fusion outperformed methods that used only EMG signals or mechanical information. For continuous performance of one walking mode (i.e., static state), the interface based on neuromuscular–mechanical fusion and a support vector machine (SVM) algorithm produced 99% or higher accuracy in the stance phase and 95% accuracy in the swing phase for locomotion-mode recognition. During mode transitions, the fusion-based SVM method correctly recognized all transitions with a sufficient predication time. These promising results demonstrate the potential of the continuous locomotion-mode classifier based on neuromuscular–mechanical fusion for neural control of prosthetic legs. PMID:21768042

  14. 20 CFR 416.990 - When and how often we will conduct a continuing disability review.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.990 When and how often we will conduct a continuing... continue to meet the disability or blindness requirements of the law. Payment ends if the medical or...

  15. 20 CFR 416.990 - When and how often we will conduct a continuing disability review.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.990 When and how often we will conduct a continuing... continue to meet the disability or blindness requirements of the law. Payment ends if the medical or...

  16. 20 CFR 416.990 - When and how often we will conduct a continuing disability review.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.990 When and how often we will conduct a continuing... continue to meet the disability or blindness requirements of the law. Payment ends if the medical or...

  17. 20 CFR 416.990 - When and how often we will conduct a continuing disability review.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.990 When and how often we will conduct a continuing... continue to meet the disability or blindness requirements of the law. Payment ends if the medical or...

  18. 20 CFR 416.990 - When and how often we will conduct a continuing disability review.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.990 When and how often we will conduct a continuing... continue to meet the disability or blindness requirements of the law. Payment ends if the medical or...

  19. Kink and Sausage Modes in Nonuniform Magnetic Slabs with Continuous Transverse Density Distributions

    NASA Astrophysics Data System (ADS)

    Yu, Hui; Li, Bo; Chen, Shao-Xia; Guo, Ming-Zhe

    2015-11-01

    We examine the influence of a continuous density structuring transverse to coronal slabs on the dispersive properties of fundamental standing kink and sausage modes supported therein. We derive generic dispersion relations (DRs) governing linear fast waves in pressureless straight slabs with general transverse density distributions, and focus on cases where the density inhomogeneity takes place in a layer of arbitrary width and in arbitrary form. The physical relevance of the solutions to the DRs is demonstrated by the corresponding time-dependent computations. For all profiles examined, the lowest order kink modes are trapped regardless of longitudinal wavenumber k. A continuous density distribution introduces a difference to their periods of ≲13% when k is the observed range relative to the case where the density profile takes a step function form. Sausage modes and other branches of kink modes are leaky at small k, and their periods and damping times are heavily influenced by how the transverse density profile is prescribed, in particular the length scale. These modes have sufficiently high quality to be observable only for physical parameters representative of flare loops. We conclude that while the simpler DR pertinent to a step function profile can be used for the lowest order kink modes, the detailed information on the transverse density structuring needs to be incorporated into studies of sausage modes and higher order kink modes.

  20. A general unified approach to modelling switching dc-to-dc converters in discontinuous conduction mode

    NASA Technical Reports Server (NTRS)

    Cuk, S.; Middlebrook, R. D.

    1977-01-01

    A method for modelling switching converters in the discontinuous conduction mode is developed, whose starting point is the unified state-space representation, and whose end result is a complete linear circuit model which correctly represents all essential features, namely, the input, output, and transfer properties (static dc as well as dynamic ac small signal). While the method is generally applicable to any switching converter operating in the discontinuous conduction mode, it is extensively illustrated for the three common power stages (buck, boost, and buck-boost). The results for these converters are then easily tabulated owing to the fixed equivalent circuit topology of their canonical circuit model.

  1. Prediction of vibration modes and thermal conductivity for amorphous ZnO-based materials

    NASA Astrophysics Data System (ADS)

    Cheng, Yu-Ting; Roy, Anindya; Falk, Michael L.

    2015-03-01

    Amorphous materials, due to their distinct physical and chemical properties, have been widely used in photovoltaics, thermoelectrics and integrated circuits. Because the thermal conductivity is critical to the performance of such devices, the thermal transport in amorphous materials has received considerable attention in the last decade. So far, a number of experimental studies and theoretical models have reported the vibration modes and thermal conductivities for amorphous Si and SiO2. However, the applicability of these vibration mode analyses and thermal conductivity models for other amorphous materials has not been studied. In this work, we employ the molecular dynamics (MD) simulations and Allen-Feldman (AF) theory to investigate the vibration modes and thermal conductivity of amorphous ZnO-based materials. ZnO is basis of a promising class of n-type semiconductors for thermoelectric application. Additionally, from this work, the contribution of individual vibrational modes to the thermal conductivity can be characterized. These results are expected to guide the interpretation of thermal transport in amorphous ZnO-based materials and the optimization for their performance with different applications.

  2. Resonantly pumped continuous-wave mode-locked Ho:YAP laser

    NASA Astrophysics Data System (ADS)

    Duan, X. M.; Lin, W. M.; Cui, Z.; Yao, B. Q.; Li, H.; Dai, T. Y.

    2016-04-01

    In this paper, we report a continuous-wave mode-locked Ho:YAP laser for the first time to our knowledge. Mode-locked pulse was produced by using an acousto-optic modulator. A 1.91-μm Tm-fiber laser as the pump source, at incident pump power of 25.9 W, the maximum output power of 2.87 W at 2117.8 nm was achieved in continuous-wave mode-locked regime. Pulse as short as 254.8 ps was obtained at repetition frequency of 81.52 MHz. In addition, the beam quality factor M 2 value of 1.6 was obtained.

  3. Modes of Continuing Professional Education: A Test of Houle's Typology with Business Education Instructors.

    ERIC Educational Resources Information Center

    Powlette, Nina M.; Young, Darius R.

    1989-01-01

    The accuracy of Houle's typology in providing an accurate conceptual description of systematic structural forms of continuing professional education and business education instructors was tested via a survey of 98 (of 129) business educators. Results of rotation factor analysis added inquiry/reinforcement to Houle's 3 learning modes of…

  4. Braking of Tearing Mode Rotation by Ferromagnetic Conducting Walls in Tokamaks

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Richard

    2015-11-01

    An in-depth investigation of the braking of tearing mode rotation in tokamak plasmas via eddy currents induced in external ferromagnetic conducting structures is performed. In general, there is a ``forbidden band'' of tearing mode rotation frequencies that separates a branch of high-frequency solutions from a branch of low-frequency solutions. When a high-frequency solution crosses the upper boundary of the forbidden band there is a bifurcation to a low-frequency solution, and vice versa. The bifurcation thresholds predicted by simple torque-balance theory (which takes into account the electromagnetic braking torque acting on the plasma, as well as the plasma viscous restoring torque, but neglects plasma inertia) are found to be essentially the same as those predicted by more complicated time-dependent mode braking theory (which takes inertia into account). Significant ferromagnetism causes otherwise electromagnetically thin conducting structures to become electromagnetically thick, and also markedly decreases the critical tearing mode amplitude above which the mode ``locks'' to the conducting structures (i.e., the high-frequency to low-frequency bifurcation is triggered). This research was funded by the U.S. Department of Energy under contract DE-FG02-04ER-54742.

  5. Phonon Heat Conduction In Nanostructures: Ballistic, Coherent, Localized, Hydrodynamic, and Divergent Modes

    NASA Astrophysics Data System (ADS)

    Chen, Gang

    In this talk, we will discuss different modes of heat conduction in nanostructures. Ballistic transport happens when phonon mean free path is longer than the characteristic size of the structure. We will discuss how we compute phonon mean free path distributions based on first-principles and measure the distributions with optical pump-probe techniques by exploring ballistic phonon transport processes. In superlattice structures, ballistic phonon transport across the whole thickness of the superlattices implies phase coherence. We observed this coherent transport in GaAs/AlAs superlattices with fixed periodic thickness and varying number of periods. Simulations show that although high frequency phonons are scattering by roughness, remaining long wavelength phonons maintain their phase and traverse the superlattices ballistically. Accessing the coherent heat conduction regime opens a new venue for phonon engineering. We show further that phonon heat conduction localization happens in GaAs/AlAs superlattice by placing ErAs nanodots at interfaces. This heat-conduction localization phenomenon is confirmed by nonequilibrium atomic Green's function simulation. These ballistic and localization effects can be exploited to improve thermoelectric energy conversion materials via reducing their thermal conductivity. In another opposite, we will discuss phonon hydrodynamic transport mode in graphene via first-principle simulations. In this mode, phonons drift with an average velocity under a temperature gradient, similar to fluid flow in a pipe. Conditions for observing such phonon hydrodynamic modes will be discussed. Finally, we will talk about the one-dimensional nature of heat conduction in polymer chains. Such 1D nature can lead to divergent thermal conductivity. Inspired by simulation, we have experimentally demonstrated high thermal conductivity in ultra-drawn polyethylene nanofibers and sheets. Work supported by DOE Office of Basic Energy Sciences under Award Number: DE

  6. Effects Of Three-Dimensional Conducting Structures On Resistive Wall Modes

    SciTech Connect

    Villone, Fabio

    2008-11-01

    This paper illustrates the effect of three-dimensional conducting structures on the evolution of Resistive Wall Modes (RWM) occurring in toroidal fusion devices. The CarMa code is used to derive the model, which then is used to design a feedback controller of RWMs. Some examples of application to the ITER geometry are reported.

  7. Continuous distributions of ventilation and gas conductance to perfusion in the lungs.

    PubMed

    Yamaguchi, K; Kawai, A; Mori, M; Asano, K; Takasugi, T; Umeda, A; Yokoyama, T

    1990-01-01

    Theoretical analysis and experimental observations were conducted to establish a method allowing to demonstrate the characteristics of distribution of ventilation (VA) as well as of diffusive conductance (G) to perfusion (Q) in the lungs. O2, CO2 and CO binding to hemoglobin molecules within the erythrocyte together with six inert gases including SF6, ethane, cyclopropane, halothane, diethyl ether and acetone, of varied solubility in blood and different diffusivity in lung tissue, were used as indicator gases. 15 patients with interstitial pneumonia of unknown etiology, placed in the supine position, were given a mixture of 21% O2 and 0.1% CO in N2 as the inspired gas and saline containing appropriate amount of the six inert gases was infused via an antecubital vein. After a steady state was established, the expired gas was collected and the samples of both arterial and mixed venous blood were simultaneously taken through catheters inserted into the femoral and pulmonary artery. The concentrations of the indicator gases in the samples were measured by gas chromatography, with electrodes or with the Scholander gas analyzer. Assuming that the mass transfer efficiency of a given indicator gas at each gas exchange unit would be limited by VA/Q and G/Q ratios, the data obtained from the human subjects were analyzed in terms of a lung model having 20 units along the VA/Q and G/Q axes, respectively. The numerical analysis including the procedure of simultaneous Bohr integration for O2, CO2 and CO in a pulmonary capillary and the method of weighted least-squares combined with constrained optimization permitted the data to be transformed into a virtually continuous distribution of Q against VA/Q and G/Q axes. The numerical procedure was strictly tested using various artificial distributions of VA/Q and G/Q ratios, showing that it could characterize the distributions containing up to at least two modes on VA/Q-G/Q field with a substantial accuracy. Analytical results

  8. Screw dislocation-induced influence of transverse modes on Hall conductivity

    NASA Astrophysics Data System (ADS)

    de Lima, André G.; Poux, Armelle; Assafrão, Denise; Filgueiras, Cleverson

    2013-11-01

    The Hall conductivity of an electron gas on an interface showing a topological defect called screw dislocation is investigated. This kind of defect induces a singular torsion on the medium which in turn induces transverse modes in the quantum Hall effect. It is shown that this topology decreases the plateaus' widths and shifts the steps in the Hall conductivity to lower magnetic fields. The Hall conductivity is neither enhanced nor diminished by the presence of this kind of defect alone. We also consider the presence of two defects on a sample, a screw dislocation together with a disclination. For a specific value of deficit angle, there is a reduction in the Hall conductivity. For an excess of angle, the steps shift to higher magnetic fields and the Hall conductivity is enhanced. Our work could be tested only in common semiconductors but we think it opens a road to the investigation on how topological defects can influence other classes of Hall effect.

  9. Second-order interference of two independent and tunable single-mode continuous-wave lasers

    NASA Astrophysics Data System (ADS)

    Jianbin, Liu; Dong, Wei; Hui, Chen; Yu, Zhou; Huaibin, Zheng; Hong, Gao; Fu-Li, Li; Zhuo, Xu

    2016-03-01

    The second-order temporal interference of two independent single-mode continuous-wave lasers is discussed by employing two-photon interference in Feynman’s path integral theory. It is concluded that whether the second-order temporal interference pattern can or cannot be retrieved via two-photon coincidence counting rate is dependent on the resolution time of the detection system and the frequency difference between these two lasers. Two identical and tunable single-mode continuous-wave diode lasers are employed to verify the predictions. These studies are helpful to understand the physics of two-photon interference with photons of different spectra. Project supported by the National Natural Science Foundation of China (Grant No. 11404255) and the Doctor Foundation of Education Ministry of China (Grant No. 20130201120013).

  10. Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

    NASA Astrophysics Data System (ADS)

    Parsapour, Amir; Dehkordi, Behzad Mirzaeian; Moallem, Mehdi

    2015-03-01

    In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared.

  11. Conduction Threshold in Accumulation-Mode InGaZnO Thin Film Transistors

    PubMed Central

    Lee, Sungsik; Nathan, Arokia

    2016-01-01

    The onset of inversion in the metal-oxide-semiconductor field-effect transistor (MOSFET) takes place when the surface potential is approximately twice the bulk potential. In contrast, the conduction threshold in accumulation mode transistors, such as the oxide thin film transistor (TFT), has remained ambiguous in view of the complex density of states distribution in the mobility gap. This paper quantitatively describes the conduction threshold of accumulation-mode InGaZnO TFTs as the transition of the Fermi level from deep to tail states, which can be defined as the juxtaposition of linear and exponential dependencies of the accumulated carrier density on energy. Indeed, this permits direct extraction and visualization of the threshold voltage in terms of the second derivative of the drain current with respect to gate voltage. PMID:26932790

  12. Conduction Threshold in Accumulation-Mode InGaZnO Thin Film Transistors.

    PubMed

    Lee, Sungsik; Nathan, Arokia

    2016-01-01

    The onset of inversion in the metal-oxide-semiconductor field-effect transistor (MOSFET) takes place when the surface potential is approximately twice the bulk potential. In contrast, the conduction threshold in accumulation mode transistors, such as the oxide thin film transistor (TFT), has remained ambiguous in view of the complex density of states distribution in the mobility gap. This paper quantitatively describes the conduction threshold of accumulation-mode InGaZnO TFTs as the transition of the Fermi level from deep to tail states, which can be defined as the juxtaposition of linear and exponential dependencies of the accumulated carrier density on energy. Indeed, this permits direct extraction and visualization of the threshold voltage in terms of the second derivative of the drain current with respect to gate voltage. PMID:26932790

  13. Conduction Threshold in Accumulation-Mode InGaZnO Thin Film Transistors

    NASA Astrophysics Data System (ADS)

    Lee, Sungsik; Nathan, Arokia

    2016-03-01

    The onset of inversion in the metal-oxide-semiconductor field-effect transistor (MOSFET) takes place when the surface potential is approximately twice the bulk potential. In contrast, the conduction threshold in accumulation mode transistors, such as the oxide thin film transistor (TFT), has remained ambiguous in view of the complex density of states distribution in the mobility gap. This paper quantitatively describes the conduction threshold of accumulation-mode InGaZnO TFTs as the transition of the Fermi level from deep to tail states, which can be defined as the juxtaposition of linear and exponential dependencies of the accumulated carrier density on energy. Indeed, this permits direct extraction and visualization of the threshold voltage in terms of the second derivative of the drain current with respect to gate voltage.

  14. Mode coupling in superconducting parallel plate resonator in a cavity with outer conductive enclosure

    SciTech Connect

    Gao, F.; Klein, M.V.; Kruse, J.; Feng, M.

    1996-06-01

    The authors have carefully studied the mode coupling effect from analysis of the measured microwave scattering parameters of superconducting films using a parallel-plate-resonator technique. Due to its high resolution and simplicity, this technique has been widely employed to identify the quality of high-{Tc} superconducting films by measuring the resonance bandwidth, from which the microwave surface resistance is directly derived. To minimize the radiation loss, the resonator is usually housed in a conductive cavity. Using this method, they observe that a number of strong ``cavity`` modes due to the test enclosure fall around the lowest TM mode of the superconducting resonator and that a strong interaction between these two types of resonant modes occurs when their eigenfrequencies are close, causing a significant distortion or a strong antiresonance for the resonator mode. To describe this effect, a coupled harmonic-oscillator model is proposed. They suggest that the interaction arises from a phase interference or a linear coupling among the individual oscillators. The model fits very well the observed Fano-type asymmetric or antiresonant features, and thus can be used to extract the intrinsic Q of the superconducting resonator.

  15. A fast technique applied to the analysis of Resistive Wall Modes with 3D conducting structures

    SciTech Connect

    Rubinacci, Guglielmo Liu, Yueqiang

    2009-03-20

    This paper illustrates the development of a 'fast' technique for the analysis of Resistive Wall Modes (RWMs) in fusion devices with three-dimensional conducting structures, by means of the recently developed CarMa code. Thanks to its peculiar features, the computational cost scales almost linearly with the number of discrete unknowns. Some large scale problems are solved in configurations of interest for the International Thermonuclear Experimental Reactor (ITER)

  16. Different photodynamic effect between continuous wave and pulsed laser irradiation modes in k562 cells in vitro

    NASA Astrophysics Data System (ADS)

    Klimenko, V. V.; Bogdanov, A. A.; Knyazev, N. A.; Rusanov, A. A.; Dubina, M. V.

    2014-10-01

    Photodynamic therapy is a cancer treatment method is used primarily continuous mode laser radiation. At high power density irradiation occurs intense consumption of molecular oxygen and this caused hypoxic tumor tissue, which leads to inefficiency PDT. In this paper, pulsed and continuous irradiation modes during PDT photosensitizer Radachlorin were compared. A mathematical model for the generation of singlet oxygen 1O2 in tumor cells during photodynamic therapy with tissue oxygenation was developed. Our study theoretically and experimentally demonstrates the increased singlet oxygen generation efficiency in a pulsed irradiation mode compared to continuous wave mode with the same power density 20mW/cm2. Experimental in vitro showed that pulsed irradiation mode mostly induces apoptosis k562 tumor cells at irradiation doses of k562 1.25 - 2.5J/cm2 while the continuous mode induced necrosis.

  17. Kelvin Modes with Nonlinear Critical Layers on a Vortex with a Continuous Velocity Profile

    NASA Astrophysics Data System (ADS)

    Maslowe, Sherwin

    2005-11-01

    The short wave cooperative instability mechanism is of interest both scientifically and because of its pertinence to the aircraft trailing vortex problem. In the first quantitative investigation of this mechanism [Tsai & Widnall (1976)], the discontinuous Rankine vortex was employed. Recently, Sipp & Jacquin [Phys. Fluids (2003)] have shown, however, that for a continuous velocity profile the modes required for the ``Widnall instabilities'' would be damped. The damping is a consequence of viscosity being used to deal with the singular critical point that occurs in the linear, inviscid theory. An alternative approach that is, in fact, more appropriate at high Reynolds numbers is to restore nonlinear terms in a thin critical layer centered on the singular point. With such a nonlinear critical layer, we show that neutral modes exist that would be damped in the linear viscous theory. These modes are non-axisymmetric and the theory is similar mathematically to that for stratified shear flows, where it has been shown that nonlinear modes, not permitted in linear theory, can occur at Richardson numbers larger than 1/4.

  18. Suppression of thermal conductivity by rattling modes in thermoelectric sodium cobaltate.

    PubMed

    Voneshen, D J; Refson, K; Borissenko, E; Krisch, M; Bosak, A; Piovano, A; Cemal, E; Enderle, M; Gutmann, M J; Hoesch, M; Roger, M; Gannon, L; Boothroyd, A T; Uthayakumar, S; Porter, D G; Goff, J P

    2013-11-01

    The need for both high electrical conductivity and low thermal conductivity creates a design conflict for thermoelectric systems, leading to the consideration of materials with complicated crystal structures. Rattling of ions in cages results in low thermal conductivity, but understanding the mechanism through studies of the phonon dispersion using momentum-resolved spectroscopy is made difficult by the complexity of the unit cells. We have performed inelastic X-ray and neutron scattering experiments that are in remarkable agreement with our first-principles density-functional calculations of the phonon dispersion for thermoelectric Na(0.8)CoO2, which has a large-period superstructure. We have directly observed an Einstein-like rattling mode at low energy, involving large anharmonic displacements of the sodium ions inside multi-vacancy clusters. These rattling modes suppress the thermal conductivity by a factor of six compared with vacancy-free NaCoO2. Our results will guide the design of the next generation of materials for applications in solid-state refrigerators and power recovery. PMID:23975057

  19. Creating Opal Templated Continuous Conducting Polymer Films with Ultralow Percolation Thresholds Using Thermally Stable Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kang, D. J.; Kwon, T.; Kim, M. P.; Kim, B. J.; Jung, H.; Bang, J.

    2012-02-01

    We propose a novel and robust strategy for creating continuous conducting polymer films with ultralow percolation thresholds using polymer-coated gold nanoparticles (Au NPs) as surfactant. Continuous poly(triphenylamine) (PTPA) films of high internal phase polymeric emulsions were fabricated using an assembly of crosslinked polystyrene (PS) colloidal particles as template. Polymer-coated Au NPs localize at the PS/PTPA interface and function as surfactant to efficiently produce a continuous conducting PTPA polymer film with very low percolation thresholds. The volume fraction threshold for percolation of the PTPA phase with insulating PS colloids was found to be 0.20. In contrast, with the addition of an extremely low volume fraction of surfactant Au NPs, the volume fraction threshold for percolation of the PTPA phase was dramatically reduced to 0.05. The SEM and TEM measurements clearly demonstrated the formation of a continuous PTPA phase within the polyhedral phase of PS colloids. To elucidate the influence of the nanoparticle surfactant on the blend films, the morphology and conductivity of the blends at different PS colloid/PTPA volume ratios were carefully characterized as a function of the Au NP concentration.

  20. Passive mode locking of an energy transfer continuous-wave dye laser

    SciTech Connect

    French, P.M.W.; Taylor, J.R.

    1986-08-01

    The first passive mode locking of a continuous-wave energy transfer dye laser is reported. Using an argon ion laser-pumped mixture of rhodamine 6G and sulphur rhodamine 101 as the active medium, pulses of less than 500 fs duration have been generated over the spectral range 652-694 nm using two different saturable absorbers in a simple linear cavity without dispersion optimization. Pulses as short as 120 fs have been measured using standard second-harmonic generation autocorrelation techniques.

  1. Continuous production of flexible carbon nanotube-based transparent conductive films

    NASA Astrophysics Data System (ADS)

    Fraser, I. Stuart; Motta, Marcelo S.; Schmidt, Ron K.; Windle, Alan H.

    2010-08-01

    This work shows a simple, single-stage, scalable method for the continuous production of high-quality carbon nanotube-polymer transparent conductive films from carbon feedstock. Besides the ease of scalability, a particular advantage of this process is that the concentration of nanotubes in the films, and thus transparency and conductivity, can be adjusted by changing simple process parameters. Therefore, films can be readily prepared for any application desired, ranging from solar cells to flat panel displays. Our best results show a surface resistivity of the order of 300 Ω square-1 for a film with 80% transparency, which is promising at this early stage of process development.

  2. Continuous-flow electrophoresis: Membrane-associated deviations of buffer pH and conductivity

    NASA Technical Reports Server (NTRS)

    Smolka, A. J. K.; Mcguire, J. K.

    1978-01-01

    The deviations in buffer pH and conductivity which occur near the electrode membranes in continuous-flow electrophoresis were studied in the Beckman charged particle electrophoresis system and the Hanning FF-5 preparative electrophoresis instrument. The nature of the membranes separating the electrode compartments from the electrophoresis chamber, the electric field strength, and the flow rate of electrophoresis buffer were all found to influence the formation of the pH and conductivity gradients. Variations in electrode buffer flow rate and the time of electrophoresis were less important. The results obtained supported the hypothesis that a combination of Donnan membrane effects and the differing ionic mobilities in the electrophoresis buffer was responsible for the formation of the gradients. The significance of the results for the design and stable operation of continuous-flow electrophoresis apparatus was discussed.

  3. Studies with sample conductivity, insertion rates, and particle deflection in a continuous flow electrophoresis system

    NASA Technical Reports Server (NTRS)

    Williams, G., Jr.

    1982-01-01

    The continuous flow electrophoresis system makes electrophoresis possible in a free-flowing film of aqueous electrolyte medium. The sample continuously enters the electrolyte at the top of the chamber and is subjected to the action of a lateral dc field. This divides the sample into fractions since each component has a distinctive electrophoretic mobility. Tests were made using monodisperse polystyrene latex microspheres to determine optimum sample conductivity, insertion rates and optimum electric field applications as baseline data for future STS flight experiments. Optimum sample flow rates for the selected samples were determined to be approximately 26 micro-liters/min. Experiments with samples in deionized water yielded best results and voltages in the 20 V/cm to 30 V/cm range were optimum. Deflections of formaldehyde fixed turkey and bovine erythrocytes were determined using the continuous flow electrophoresis system. The effects of particle interactions on sample resolution and migration in the chamber was also evaluated.

  4. Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb

    SciTech Connect

    Pooser, Raphael C.; Jing, Jietai

    2014-10-20

    One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexing in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.

  5. Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb

    DOE PAGESBeta

    Pooser, Raphael C.; Jing, Jietai

    2014-10-20

    One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexingmore » in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.« less

  6. Scaling of Electron Thermal Conductivity during the Transition between Slab and Mixed Slab-Toroidal ETG Mode

    NASA Astrophysics Data System (ADS)

    Sokolov, Vladimir; Balbaky, Abed; Sen, Amiya K.

    2015-11-01

    Transition from the slab to the toroidal branch of the electron temperature gradient (ETG) mode has been successfully achieved in a basic experiment in Columbia Linear Machine CLM. We found a modest increase in saturated ETG potential fluctuations (~ 2 ×) and a substantial increase in the power density of individual mode peaks (~ 4 - 5 ×) with increased levels of curvature. We have obtained a set of experimental scalings for electron thermal conductivity χ⊥e as a function of the inverse radius of curvature Rc-1 for different fluctuation levels of the initial slab ETG mode. We found that thermal conductivity for pure slab modes is larger than it is for mixed slab-toroidal ETG modes with the same level of mode fluctuation. This effective reduction in diffusive transport can be partly explained by the flute nature of the toroidal ETG mode. This research was supported by the Department of Electrical Engineering of Columbia University.

  7. Efficient continuous wave and passively mode-locked Tm-doped crystalline silicate laser.

    PubMed

    Yang, K J; Bromberger, H; Heinecke, D; Kölbl, C; Schäfer, H; Dekorsy, T; Zhao, S Z; Zheng, L H; Xu, J; Zhao, G J

    2012-08-13

    An efficient continuous wave and passively mode-locked thulium-doped oxyorthosilicate Tm:LuYSiO5 laser is demonstrated. A maximum slope efficiency of 56.3% is obtained at 2057.4 nm in continuous wave operation regime. With an InGaAs quantum well SESAM, self-starting passively mode-locked Tm:LuYSiO5 laser is realized in the 1929 nm to 2065 nm spectral region. A maximum average output power of 130.2 mW with a pulse duration of 33.1 ps and a repetition rate of about 100 MHz is generated at 1984.1 nm. Pulses as short as 24.2 ps with an average output power of 100 mW are obtained with silicon prisms where used to manage the intracavity dispersion. The shortest pulse duration of about 19.6 ps is obtained with an average output power of 64.5 mW at 1944.3 nm. PMID:23038503

  8. Real-Time Quadrature Measurement of a Single-Photon Wave Packet with Continuous Temporal-Mode Matching

    NASA Astrophysics Data System (ADS)

    Ogawa, Hisashi; Ohdan, Hideaki; Miyata, Kazunori; Taguchi, Masahiro; Makino, Kenzo; Yonezawa, Hidehiro; Yoshikawa, Jun-ichi; Furusawa, Akira

    2016-06-01

    Real-time controls based on quantum measurements are powerful tools for various quantum protocols. However, their experimental realization has been limited by mode mismatch between the temporal mode of quadrature measurement and that heralded by photon detection. Here, we demonstrate real-time quadrature measurement of a single-photon wave packet induced by photon detection by utilizing continuous temporal-mode matching between homodyne detection and an exponentially rising temporal mode. Single photons in exponentially rising modes are also expected to be useful resources for interactions with other quantum systems.

  9. Continuity in different care modes and its relationship to quality of life: a randomised controlled trial in patients with COPD

    PubMed Central

    Uijen, Annemarie A; Bischoff, Erik WMA; Schellevis, Francois G; Bor, Hans HJ; van den Bosch, Wil JHM; Schers, Henk J

    2012-01-01

    Background New care modes in primary care may affect patients’ experienced continuity of care. Aim To analyse whether experienced continuity for patients with chronic obstructive pulmonary disease (COPD) changes after different care modes are introduced, and to analyse the relationship between continuity of care and patients’ quality of life. Design and setting Randomised controlled trial with 2-year follow-up in general practice in the Netherlands. Method A total of 180 patients with COPD were randomly assigned to three different care modes: self-management, regular monitoring by a practice nurse, and care provided by the GP at the patient's own initiative (usual care). Experienced continuity of care as personal continuity (proportion of visits with patient's own GP) and team continuity (continuity by the primary healthcare team) was measured using a self-administered patient questionnaire. Quality of life was measured using the Chronic Respiratory Questionnaire. Results Of the final sample (n = 148), those patients receiving usual care experienced the highest personal continuity, although the chance of not contacting any care provider was also highest in this group (29% versus 2% receiving self-management, and 5% receiving regular monitoring). There were no differences in experienced team continuity in the three care modes. No relationship was found between continuity and changes in quality of life. Conclusion Although personal continuity decreases when new care modes are introduced, no evidence that this affects patients’ experienced team continuity or patients’ quality of life was found. Patients still experienced smooth, ongoing care, and considered care to be connected. Overall, no evidence was found indicating that the introduction of new care modes in primary care for patients with COPD should be discouraged. PMID:22687235

  10. Continuous Patterning of Copper Nanowire-Based Transparent Conducting Electrodes for Use in Flexible Electronic Applications.

    PubMed

    Zhong, Zhaoyang; Lee, Hyungjin; Kang, Dongwoo; Kwon, Sin; Choi, Young-Man; Kim, Inhyuk; Kim, Kwang-Young; Lee, Youngu; Woo, Kyoohee; Moon, Jooho

    2016-08-23

    Simple, low-cost and scalable patterning methods for Cu nanowire (NW)-based flexible transparent conducting electrodes (FTCEs) are essential for the widespread use of Cu NW FTCEs in numerous flexible optoelectronic devices, wearable devices, and electronic skins. In this paper, continuous patterning for Cu NW FTCEs via a combination of selective intense pulsed light (IPL) and roll-to-roll (R2R) wiping process was explored. The development of continuous R2R patterning could be achieved because there was significant difference in adhesion properties between NWs and substrates depending on whether Cu NW coated area was irradiated by IPL or not. Using a custom-built, R2R-based wiping apparatus, it was confirmed that nonirradiated NWs could be clearly removed out without any damage on irradiated NWs strongly adhered to the substrate, resulting in continuous production of low-cost Cu NW FTCE patterns. In addition, the variations in microscale pattern size by varying IPL process parameters/the mask aperture sizes were investigated, and possible factors affecting on developed pattern size were meticulously examined. Finally, the successful implementation of the patterned Cu NW FTCEs into a phosphorescent organic light-emitting diode (PhOLED) and a flexible transparent conductive heater (TCH) were demonstrated, verifying the applicability of the patterned FTCEs. It is believed that our study is the key step toward realizing the practical use of NW FTCEs in various flexible electronic devices. PMID:27434639

  11. 2.1 kW single mode continuous wave monolithic fiber laser

    NASA Astrophysics Data System (ADS)

    Rosales-Garcia, Andrea; Tobioka, Hideaki; Abedin, Kazi; Dong, Hao; Várallyay, Zoltán.; Szabó, Áron; Taunay, Thierry; Sullivan, Sean; Headley, Clifford

    2015-03-01

    A robust, alignment-free monolithic 2.1 kW single-mode continuous wave fiber laser, operating at 1083 nm is demonstrated. The laser is pumped with commercial fiber pigtailed multimode diodes through all-fiber pump-signal power combiners in a MOPA architecture. The oscillator was formed with high reflector and output coupler fiber Bragg gratings written in 11/200 μm (mode field/cladding diameter) single-mode fiber. The gain medium was a 19m OFS commercial 11/200 μm double clad Yb-doped fiber (DCY). Pump light was coupled to the oscillator using two 11/200 μm pump-signal power combiners (PSC). A total of 20 commercially available 58W pump diodes at 915 nm were used to generate 800W of signal, as measured before the amplifier. The Raman power after the oscillator was more than 60 dB below the signal power. The amplifier was built using 13 m of 14/200 µm DCY and two (18+1)x1 PSC combiners with more than 95% pump and signal light transmission. A total of 2 kW of power was used to bi-directionally pump the amplifier. The output was measured after 3 m 14/200 μm fiber, and 10 m 100/360 μm delivery cable. Total signal output power was 2.1 kW, corresponding to an amplifier slope efficiency of 77%. The Raman power is more than 30 dB below the signal power. At maximum power, no modal instabilities, thermal effects, nor power rollover were observed. With higher power pumps, it is predicted that a power level of 2.6 kW can be achieved with the Raman level below 20 dB.

  12. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    PubMed

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies. PMID:24534328

  13. Propagating mode-I fracture in amorphous materials using the continuous random network model

    NASA Astrophysics Data System (ADS)

    Heizler, Shay I.; Kessler, David A.; Levine, Herbert

    2011-08-01

    We study propagating mode-I fracture in two-dimensional amorphous materials using atomistic simulations. We use the continuous random network model of an amorphous material, creating samples using a two-dimensional analog of the Wooten-Winer-Weaire Monte Carlo algorithm. For modeling fracture, molecular-dynamics simulations were run on the resulting samples. The results of our simulations reproduce the main experimental features. In addition to achieving a steady-state crack under a constant driving displacement (which has not yet been achieved by other atomistic models for amorphous materials), the runs show microbranching, which increases with driving, transitioning to macrobranching for the largest drivings. In addition to the qualitative visual similarity of the simulated cracks to experiment, the simulation also succeeds in reproducing qualitatively the experimentally observed oscillations of the crack velocity.

  14. Continuous monitoring of bacterial biofilm growth using uncoated Thickness-Shear Mode resonators

    NASA Astrophysics Data System (ADS)

    Castro, P.; Resa, P.; Durán, C.; Maestre, J. R.; Mateo, M.; Elvira, L.

    2012-12-01

    Quartz Crystal Microbalances (QCM) were used to nondestructively monitor in real time the microbial growth of the bacteria Staphylococcus epidermidis (S. epidermidis) in a liquid broth. QCM, sometimes referred to as Thickness-Shear Mode (TSM) resonators, are highly sensitive sensors not only able to measure very small mass, but also non-gravimetric contributions of viscoelastic media. These devices can be used as biosensors for bacterial detection and are employed in many applications including their use in the food industry, water and environment monitoring, pharmaceutical sciences and clinical diagnosis. In this work, three strains of S. epidermidis (which differ in the ability to produce biofilm) have been continuously monitored using an array of piezoelectric TSM resonators, at 37 °C in a selective culturing media. Microbial growth was followed by measuring the changes in the crystal resonant frequency and bandwidth at several harmonics. It was shown that microbial growth can be monitored in real time using multichannel and multiparametric QCM sensors.

  15. Continuous electrodeposition for lightweight, highly conducting and strong carbon nanotube-copper composite fibers.

    PubMed

    Xu, Geng; Zhao, Jingna; Li, Shan; Zhang, Xiaohua; Yong, Zhenzhong; Li, Qingwen

    2011-10-01

    Carbon nanotube (CNT) fiber is a promising candidate for lightweight cables. The introduction of metal particles on a CNT fiber can effectively improve its electrical conductivity. However, the decrease in strength is observed in CNT-metal composite fibers. Here we demonstrate a continuous process, which combines fiber spinning, CNT anodization and metal deposition, to fabricate lightweight and high-strength CNT-Cu fibers with metal-like conductivities. The composite fiber with anodized CNTs exhibits a conductivity of 4.08 × 10(4)-1.84 × 10(5) S cm(-1) and a mass density of 1.87-3.08 g cm(-3), as the Cu thickness is changed from 1 to 3 μm. It can be 600-811 MPa in strength, as strong as the un-anodized pure CNT fiber (656 MPa). We also find that during the tensile tests there are slips between the inner CNTs and the outer Cu layer, leading to the drops in electrical conductivity. Therefore, there is an effective fiber strength before which the Cu layer is robust. Due to the improved interfacial bonding between the Cu layer and the anodized CNT surfaces, such effective strength is still high, up to 490-570 MPa. PMID:21879118

  16. Survival of Listeria monocytogenes and Salmonella spp. on catfish exposed to microwave heating in a continuous mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave (MW) heating using continuous output may provide better and consistent cooking for foods. Currently, household units with a build-in inverter device are available in which the output is continuous vs. the traditional on-off mode. With an inverter, these MW ovens may provide consistent he...

  17. Efficient polyhydroxyalkanoate (PHA) accumulation by a new continuous feeding mode in three-stage mixed microbial culture (MMC) PHA production process.

    PubMed

    Chen, Zhiqiang; Huang, Long; Wen, Qinxue; Guo, Zirui

    2015-09-10

    A new continuous feeding mode was developed to optimize the polyhydroxyalkanoates (PHAs) accumulation step in the three-stage PHAs production process by mixed microbial cultures (MMCs) using mixed volatile fatty acids (VFAs) as substrate. The continuous feeding assays under low biomass loading rate (BLR) (in the range of 3.5-5.5Cmol VFA/Cmol X/d) can be directly fed with feedstock with pH from 5.0 to 10.0 without any pH regulation. The maximum intracellular PHA content of 70.4% and system PHA yield (YPHA/S(sys)) of 0.81Cmol PHA/Cmol VFA were achieved under the continuous feeding mode at BLR of 3.86Cmol VFA/Cmol X/d when directly fed with substrate at pH 5. These values were higher than those under the pulse wise feeding mode with the same substrate and active biomass concentration. The results indicated that a self-balanced pH state was formed in the continuous feeding system. Further studies on the reaction pH and kinetics of the MMCs in the continuous feeding reactor were conducted to understand the pH variation mechanism and accumulation process. The optimal BLR to get high PHA content and YPHA/S(sys) was 3.5-5.5Cmol VFA/Cmol X/d. PMID:26073996

  18. Enhanced method to reconstruct mode shapes of continuous scanning measurements using the Hilbert Huang transform and the modal analysis method

    SciTech Connect

    Lee, Jongsuh; Hussain, Syed Hassaan; Wang, Semyung Park, Kyihwan

    2014-09-15

    Generally, it is time consuming to experimentally identify the operating deflection shape or mode shape of a structure. To overcome this problem, the Hilbert Huang transform (HHT) technique has been recently proposed. This technique is used to extract the mode shape from measurements that continuously measure the vibration of a region of interest within a structure using a non-contact laser sensor. In previous research regarding the HHT, two technical processes were needed to obtain the mode shape for each mode. The purpose of this study is to improve and complement our previous research, and for this purpose, a modal analysis approach is adapted without using the two technical processes to obtain an accurate un-damped impulse response of each mode for continuous scanning measurements. In addition, frequency response functions for each type of beam are derived, making it possible to make continuously scanned measurements along a straight profile. In this paper, the technical limitations and drawbacks of the damping compensation technique used in previous research are identified. In addition, the separation of resonant frequency (the Doppler effect) that occurs in continuous scanning measurements and the separation of damping phenomenon are also observed. The proposed method is quantitatively verified by comparing it with the results obtained from a conventional approach to estimate the mode shape with an impulse response.

  19. Enhanced method to reconstruct mode shapes of continuous scanning measurements using the Hilbert Huang transform and the modal analysis method.

    PubMed

    Lee, Jongsuh; Hussain, Syed Hassaan; Wang, Semyung; Park, Kyihwan

    2014-09-01

    Generally, it is time consuming to experimentally identify the operating deflection shape or mode shape of a structure. To overcome this problem, the Hilbert Huang transform (HHT) technique has been recently proposed. This technique is used to extract the mode shape from measurements that continuously measure the vibration of a region of interest within a structure using a non-contact laser sensor. In previous research regarding the HHT, two technical processes were needed to obtain the mode shape for each mode. The purpose of this study is to improve and complement our previous research, and for this purpose, a modal analysis approach is adapted without using the two technical processes to obtain an accurate un-damped impulse response of each mode for continuous scanning measurements. In addition, frequency response functions for each type of beam are derived, making it possible to make continuously scanned measurements along a straight profile. In this paper, the technical limitations and drawbacks of the damping compensation technique used in previous research are identified. In addition, the separation of resonant frequency (the Doppler effect) that occurs in continuous scanning measurements and the separation of damping phenomenon are also observed. The proposed method is quantitatively verified by comparing it with the results obtained from a conventional approach to estimate the mode shape with an impulse response. PMID:25273766

  20. The effects of continuous and intermittent reduced speed modes on renal and intestinal perfusion in an ovine model.

    PubMed

    Tuzun, Egemen; Chorpenning, Katherine; Liu, Maxine Qun; Bonugli, Katherine; Tamez, Dan; Lenox, Mark; Miller, Matthew W; Fossum, Theresa W

    2014-01-01

    The effects of the continuous-flow output on renal and intestinal microcirculation have not been extensively studied. To address this, the Heartware HVAD pump loaded with continuous and intermittent reduced speed (IRS) modes was implanted in four sheep and then operated at low and high speeds to mimic partial and complete unloading of the left ventricle. Then microsphere and positron emission tomography/computed tomography (PET/CT) studies were used to assess renal and intestinal tissue perfusion at various pump speeds and flow modes as compared with baseline (pump off). Arterial and venous oxygen (T02) and carbon dioxide (TCO2) contents were measured to assess changes in intestinal metabolism. Renal and intestinal regional blood flows did not produce any significant changes compared with baseline values in either continuous or IRS modes and speeds. The venous TO2 and TCO2 significantly increased in continuous and IRS modes and speeds compared with baseline. Our data suggested that renal and intestinal tissue perfusions were not adversely affected by continuous and IRS modes either in partial or complete unloading. Intestinal venous hyperoxia and increased TCO2 may be the evidence of intestinal arteriovenous shunting along with increased intestinal tissue metabolism. Longer-term studies are warranted in chronic heart failure models. PMID:24299973

  1. Continuous operation of monolithic dynamic-single-mode coupled-cavity lasers

    SciTech Connect

    Coldren, L.A.; Ebeling, K.J.; Rentschler, J.A.; Burrus, C.A.; Wilt, D.P.

    1984-02-15

    The first cw monolithic two-section lasers were fabricated using reactive-ion-etched grooves in buried-crescent wafers. Tunable single-mode selection with spurious mode levels down approx.20 dB was demonstrated under modulation.

  2. General Boundary-Value Problems for the Heat Conduction Equation with Piecewise-Continuous Coefficients

    NASA Astrophysics Data System (ADS)

    Tatsii, R. M.; Pazen, O. Yu.

    2016-03-01

    A constructive scheme for the construction of a solution of a mixed problem for the heat conduction equation with piecewise-continuous coefficients coordinate-dependent in the final interval is suggested and validated in the present work. The boundary conditions are assumed to be most general. The scheme is based on: the reduction method, the concept of quasi-derivatives, the currently accepted theory of the systems of linear differential equations, the Fourier method, and the modified method of eigenfunctions. The method based on this scheme should be related to direct exact methods of solving mixed problems that do not employ the procedures of constructing Green's functions or integral transformations. Here the theorem of eigenfunction expansion is adapted for the case of coefficients that have discontinuity points of the 1st kind. The results obtained can be used, for example, in investigating the process of heat transfer in a multilayer slab under conditions of ideal thermal contact between the layers. A particular case of piecewise-continuous coefficients is considered. A numerical example of calculation of a temperature field in a real four-layer building slab under boundary conditions of the 3rd kind (conditions of convective heat transfer) that model the phenomenon of fire near one of the external surfaces is given.

  3. 14-W continuous-wave mode-locked Nd:YAG laser

    SciTech Connect

    De Silvestri, S.; Laporta, P.; Magni, V.

    1986-12-01

    A new design procedure for solid-state laser resonators operating in the fundamental mode is applied to the optimization of the mode volume and stability of a cw Nd:YAG laser. The optimized laser provides the highest power in the mode-locking regime reported to date.

  4. Sliding mode control of continuous time systems with reaching law based on exponential function

    NASA Astrophysics Data System (ADS)

    Gamorski, Piotr

    2015-11-01

    In this paper a pseudo-sliding mode control is proposed by introducing a continuous and smooth input signal in order to guarantee both chattering elimination and boundedness of sliding variable derivative in the presence of non-zero external disturbance. For this purpose, having fixed a suitable sliding manifold, a homogeneous differential equation describing the sliding variable evolution is considered. It is discussed later in this paper that the input signal formed on the basis of this equation provides asymptotic convergence of the sliding variable and its derivative to zero as well as the asymptotic stability of the non-linear system in the absence of external disturbance. The dynamics of the system affected by non-zero external disturbance make the state vector converge to domains in a vicinity of the origin at the exponential rate, as the norm of arbitrary trajectory is limited to decreasing exponential function. In order to expand the variety of controllers based on a reaching law and providing the above-mentioned properties, a certain class of functions is presented.

  5. Picosecond pulses from wavelength-swept continuous-wave Fourier domain mode-locked lasers

    NASA Astrophysics Data System (ADS)

    Eigenwillig, Christoph M.; Wieser, Wolfgang; Todor, Sebastian; Biedermann, Benjamin R.; Klein, Thomas; Jirauschek, Christian; Huber, Robert

    2013-05-01

    Ultrafast lasers have a crucial function in many fields of science; however, up to now, high-energy pulses directly from compact, efficient and low-power semiconductor lasers are not available. Therefore, we introduce a new approach based on temporal compression of the continuous-wave, wavelength-swept output of Fourier domain mode-locked lasers, where a narrowband optical filter is tuned synchronously to the round-trip time of light in a kilometre-long laser cavity. So far, these rapidly swept lasers enabled orders-of-magnitude speed increase in optical coherence tomography. Here we report on the generation of ~60-70 ps pulses at 390 kHz repetition rate. As energy is stored optically in the long-fibre delay line and not as population inversion in the laser-gain medium, high-energy pulses can now be generated directly from a low-power, compact semiconductor-based oscillator. Our theory predicts subpicosecond pulses with this new technique in the future.

  6. Carotid wall stress calculated with continuous intima-media thickness assessment using B-mode ultrasound

    NASA Astrophysics Data System (ADS)

    Pascaner, A. F.; Craiem, D.; Casciaro, M. E.; Danielo, R.; Graf, S.; Guevara, E.

    2016-04-01

    Cardiovascular risk is normally assessed using clinical risk factors but it can be refined using non-invasive infra-clinical markers. Intima-Media Thickness (IMT) is recognized as an early indicator of cardiovascular disease. Carotid Wall Stress (CWS) can be calculated using arterial pressure and carotid size (diameter and IMT). Generally, IMT is measured during diastole when it reaches its maximum value. However, it changes during the cardiac cycle and a time-dependant waveform can be obtained using B-mode ultrasound images. In this work we calculated CWS considering three different approaches for IMT assessment: (i) constant IMT (standard diastolic value), (ii) estimated IMT from diameter waveform (assuming a constant cross-sectional wall area) and (iii) continuously measured IMT. Our results showed that maximum wall stress depends on the IMT estimation method. Systolic CWS progressively increased using the three approaches (p<0.024). We conclude that maximum CWS is highly dependent on wall thickness and accurate IMT measures during systole should be encouraged.

  7. Improved dichotomous search frequency offset estimator for burst-mode continuous phase modulation

    NASA Astrophysics Data System (ADS)

    Zhai, Wen-Chao; Li, Zan; Si, Jiang-Bo; Bai, Jun

    2015-11-01

    A data-aided technique for carrier frequency offset estimation with continuous phase modulation (CPM) in burst-mode transmission is presented. The proposed technique first exploits a special pilot sequence, or training sequence, to form a sinusoidal waveform. Then, an improved dichotomous search frequency offset estimator is introduced to determine the frequency offset using the sinusoid. Theoretical analysis and simulation results indicate that our estimator is noteworthy in the following aspects. First, the estimator can operate independently of timing recovery. Second, it has relatively low outlier, i.e., the minimum signal-to-noise ratio (SNR) required to guarantee estimation accuracy. Finally, the most important property is that our estimator is complexity-reduced compared to the existing dichotomous search methods: it eliminates the need for fast Fourier transform (FFT) and modulation removal, and exhibits faster convergence rate without accuracy degradation. Project supported by the National Natural Science Foundation of China (Grant No. 61301179), the Doctorial Programs Foundation of the Ministry of Education, China (Grant No. 20110203110011), and the Programme of Introducing Talents of Discipline to Universities, China (Grant No. B08038).

  8. Polarization-dependent continuous change in the propagation direction of Dirac-cone modes in photonic-crystal slabs

    NASA Astrophysics Data System (ADS)

    Sakoda, Kazuaki

    2014-07-01

    We show that the propagation direction of the Dirac-cone modes of photonic-crystal slabs can be continuously controlled by the polarization of the incident wave. This property is realized by their isotropic dispersion relation and anisotropic mixture of two dipolar wave functions. To clarify these features, we formulate a Green-function method to describe the excitation process of the Dirac-cone modes and analyze the coupling strength with the incident wave by group theory. This angular dependence of the intensity distribution of the excited wave can be used for experimentally detecting the Dirac cones and distinguishing their mode symmetry.

  9. Regularization of singular eigenfunctions of an operator with continuous spectra: With applications for ballooning modes in toroidally rotating tokamaks

    NASA Astrophysics Data System (ADS)

    Furukawa, M.; Yoshida, Z.; Tokuda, S.

    2005-07-01

    Eigenfunction expansions of fields encounter practical difficulty when the generating operator has continuous spectra (as is common in magnetohydrodynamics theories). An appropriate "weight function" may remove the singularity of the eigenfunctions belonging to the continuous spectrum and the complete set of regularized (square-integrable) eigenfunctions can be obtained. As an example, this method has been applied for ballooning modes in toroidally rotating tokamaks. While the weight function truncates the long-term behavior of modes, the regularized eigenfunctions can describe transient behavior within a finite time.

  10. Doped SnO₂ transparent conductive multilayer thin films explored by continuous composition spread.

    PubMed

    Lee, Jin Ju; Ha, Jong-Yoon; Choi, Won-Kook; Cho, Yong Soo; Choi, Ji-Won

    2015-04-13

    Mn-doped SnO₂ thin films were fabricated by a continuous composition spread (CCS) method on a glass substrate at room temperature to find optimized compositions. The fabricated materials were found to have a lower resistivity than pure SnO₂ thin films because of oxygen vacancies generated by Mn doping. As Mn content was increased, resistivity was found to decrease for limited doping concentrations. The minimum thin film resistivity was 0.29 Ω-cm for a composition of 2.59 wt % Mn-doped SnO₂. The Sn-O vibrational stretching frequency in FT-IR showed a blue shift, consistent with oxygen deficiency. Mn-doped SnO₂/Ag/Mn-doped SnO₂ multilayer structures were fabricated using this optimized composition deposited by an on-axis radio frequency (RF) sputter. The multilayer transparent conducting oxide film had a resistivity of 7.35 × 10⁻⁵ Ω-cm and an average transmittance above 86% in the 550 nm wavelength region. PMID:25761303

  11. Toward integrated multi-scale pedestal simulations including edge-localized-mode dynamics, evolution of edge-localized-mode cycles, and continuous fluctuations

    NASA Astrophysics Data System (ADS)

    Xu, X. Q.; Xia, T. Y.; Yan, N.; Liu, Z. X.; Kong, D. F.; Diallo, A.; Groebner, R. J.; Hubbard, A. E.; Hughes, J. W.

    2016-05-01

    The high-fidelity BOUT++ two-fluid code suite has demonstrated significant recent progress toward integrated multi-scale simulations of tokamak pedestal, including Edge-Localized-Mode (ELM) dynamics, evolution of ELM cycles, and continuous fluctuations, as observed in experiments. Nonlinear ELM simulations show three stages of an ELM event: (1) a linear growing phase; (2) a fast crash phase; and (3) a slow inward turbulence spreading phase lasting until the core heating flux balances the ELM energy loss and the ELM is terminated. A new coupling/splitting model has been developed to perform simulations of multi-scale ELM dynamics. Simulation tracks five ELM cycles for 10 000 Alfvén times for small ELMs. The temporal evolution of the pedestal pressure is similar to that of experimental measurements for the pedestal pressure profile collapses and recovers to a steep gradient during ELM cycles. To validate BOUT++ simulations against experimental data and develop physics understanding of the fluctuation characteristics for different tokamak operation regimes, both quasi-coherent fluctuations (QCFs) in ELMy H-modes and Weakly Coherent Modes in I-modes have been simulated using three dimensional 6-field 2-fluid electromagnetic model. The H-mode simulation results show that (1) QCFs are localized in the pedestal region having a predominant frequency at f ≃300 -400 kHz and poloidal wavenumber at kθ≃0.7 cm-1 , and propagate in the electron diamagnetic direction in the laboratory frame. The overall signatures of simulation results for QCFs show good agreement with C-Mod and DIII-D measurements. (2) The pedestal profiles giving rise to QCFs are near the marginal instability threshold for ideal peeling-ballooning modes for both C-Mod and DIII-D, while the collisional electromagnetic drift-Alfvén wave appears to be dominant for DIII-D. (3) Particle diffusivity is either smaller than the heat diffusivity for DIII-D or similar to the heat diffusivity for C-Mod. Key I-mode

  12. 20 CFR 220.186 - When and how often the Board will conduct a continuing disability review.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true When and how often the Board will conduct a continuing disability review. 220.186 Section 220.186 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT DETERMINING DISABILITY Continuing or Stopping Disability Due to Substantial Gainful Activity or...

  13. 20 CFR 220.186 - When and how often the Board will conduct a continuing disability review.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false When and how often the Board will conduct a continuing disability review. 220.186 Section 220.186 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT DETERMINING DISABILITY Continuing or Stopping Disability Due to Substantial Gainful Activity or...

  14. Effects of carbon brush anode size and loading on microbial fuel cell performance in batch and continuous mode

    NASA Astrophysics Data System (ADS)

    Lanas, Vanessa; Ahn, Yongtae; Logan, Bruce E.

    2014-02-01

    Larger scale microbial fuel cells (MFCs) require compact architectures to efficiently treat wastewater. We examined how anode-brush diameter, number of anodes, and electrode spacing affected the performance of the MFCs operated in fed-batch and continuous flow mode. All anodes were initially tested with the brush core set at the same distance from the cathode. In fed-batch mode, the configuration with three larger brushes (25 mm diameter) produced 80% more power (1240 mW m-2) than reactors with eight smaller brushes (8 mm) (690 mW m-2). The higher power production by the larger brushes was due to more negative and stable anode potentials than the smaller brushes. The same general result was obtained in continuous flow operation, although power densities were reduced. However, by moving the center of the smaller brushes closer to the cathode (from 16.5 to 8 mm), power substantially increased from 690 to 1030 mW m-2 in fed batch mode. In continuous flow mode, power increased from 280 to 1020 mW m-2, resulting in more power production from the smaller brushes than the larger brushes (540 mW m-2). These results show that multi-electrode MFCs can be optimized by selecting smaller anodes, placed as close as possible to the cathode.

  15. Multipartite entanglement in three-mode Gaussian states of continuous-variable systems: Quantification, sharing structure, and decoherence

    SciTech Connect

    Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

    2006-03-15

    We present a complete analysis of the multipartite entanglement of three-mode Gaussian states of continuous-variable systems. We derive standard forms which characterize the covariance matrix of pure and mixed three-mode Gaussian states up to local unitary operations, showing that the local entropies of pure Gaussian states are bound to fulfill a relationship which is stricter than the general Araki-Lieb inequality. Quantum correlations can be quantified by a proper convex roof extension of the squared logarithmic negativity, the continuous-variable tangle, or contangle. We review and elucidate in detail the proof that in multimode Gaussian states the contangle satisfies a monogamy inequality constraint [G. Adesso and F. Illuminati, New J. Phys8, 15 (2006)]. The residual contangle, emerging from the monogamy inequality, is an entanglement monotone under Gaussian local operations and classical communications and defines a measure of genuine tripartite entanglements. We determine the analytical expression of the residual contangle for arbitrary pure three-mode Gaussian states and study in detail the distribution of quantum correlations in such states. This analysis yields that pure, symmetric states allow for a promiscuous entanglement sharing, having both maximum tripartite entanglement and maximum couplewise entanglement between any pair of modes. We thus name these states GHZ/W states of continuous-variable systems because they are simultaneous continuous-variable counterparts of both the GHZ and the W states of three qubits. We finally consider the effect of decoherence on three-mode Gaussian states, studying the decay of the residual contangle. The GHZ/W states are shown to be maximally robust against losses and thermal noise.

  16. Multipartite entanglement in three-mode Gaussian states of continuous-variable systems: Quantification, sharing structure, and decoherence

    NASA Astrophysics Data System (ADS)

    Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

    2006-03-01

    We present a complete analysis of the multipartite entanglement of three-mode Gaussian states of continuous-variable systems. We derive standard forms which characterize the covariance matrix of pure and mixed three-mode Gaussian states up to local unitary operations, showing that the local entropies of pure Gaussian states are bound to fulfill a relationship which is stricter than the general Araki-Lieb inequality. Quantum correlations can be quantified by a proper convex roof extension of the squared logarithmic negativity, the continuous-variable tangle, or contangle. We review and elucidate in detail the proof that in multimode Gaussian states the contangle satisfies a monogamy inequality constraint [G. Adesso and F. Illuminati, New J. Phys8, 15 (2006)]. The residual contangle, emerging from the monogamy inequality, is an entanglement monotone under Gaussian local operations and classical communications and defines a measure of genuine tripartite entanglements. We determine the analytical expression of the residual contangle for arbitrary pure three-mode Gaussian states and study in detail the distribution of quantum correlations in such states. This analysis yields that pure, symmetric states allow for a promiscuous entanglement sharing, having both maximum tripartite entanglement and maximum couplewise entanglement between any pair of modes. We thus name these states GHZ/W states of continuous-variable systems because they are simultaneous continuous-variable counterparts of both the GHZ and the W states of three qubits. We finally consider the effect of decoherence on three-mode Gaussian states, studying the decay of the residual contangle. The GHZ/W states are shown to be maximally robust against losses and thermal noise.

  17. Modes of high-latitude auroral conductance variability derived from DMSP energetic electron precipitation observations: Empirical orthogonal function analysis

    NASA Astrophysics Data System (ADS)

    McGranaghan, Ryan; Knipp, Delores J.; Matsuo, Tomoko; Godinez, Humberto; Redmon, Robert J.; Solomon, Stanley C.; Morley, Steven K.

    2015-12-01

    We provide the first ever characterization of the primary modes of ionospheric Hall and Pedersen conductance variability as empirical orthogonal functions (EOFs). These are derived from six satellite years of Defense Meteorological Satellite Program (DMSP) particle data acquired during the rise of solar cycles 22 and 24. The 60 million DMSP spectra were each processed through the Global Airlglow Model. Ours is the first large-scale analysis of ionospheric conductances completely free of assumption of the incident electron energy spectra. We show that the mean patterns and first four EOFs capture ˜50.1 and 52.9% of the total Pedersen and Hall conductance variabilities, respectively. The mean patterns and first EOFs are consistent with typical diffuse auroral oval structures and quiet time strengthening/weakening of the mean pattern. The second and third EOFs show major disturbance features of magnetosphere-ionosphere (MI) interactions: geomagnetically induced auroral zone expansion in EOF2 and the auroral substorm current wedge in EOF3. The fourth EOFs suggest diminished conductance associated with ionospheric substorm recovery mode. We identify the most important modes of ionospheric conductance variability. Our results will allow improved modeling of the background error covariance needed for ionospheric assimilative procedures and improved understanding of MI coupling processes.

  18. How I Learned to Design and Conduct Semi-Structured Interviews: An Ongoing and Continuous Journey

    ERIC Educational Resources Information Center

    Rabionet, Silvia E.

    2011-01-01

    Qualitative interviewing is a flexible and powerful tool to capture the voices and the ways people make meaning of their experience Learning to conduct semi-structure interviews requires the following six stages: (a) selecting the type of interview; (b) establishing ethical guidelines, (c) crafting the interview protocol; (d) conducting and…

  19. Continuity and Change in Middle Class Fatherhood, 1925-1939: The Culture-Conduct Connection.

    ERIC Educational Resources Information Center

    LaRossa, Ralph; Reitzes, Donald C.

    1993-01-01

    Conducted content analysis of advice-seeking letters penned between 1925 and 1939 by fathers and mothers concerned with childrearing. Findings support proposition that culture of fatherhood and conduct of fatherhood in Depression-era America were at odds. Found connection between culture of fatherhood and attitudes of mothers toward fathers.…

  20. Operation of Terahertz Quantum-cascade Lasers at 164 K in Pulsed Mode and at 117 K in Continuous-wave Mode

    NASA Technical Reports Server (NTRS)

    Williams, Benjamin S.; Kumar, Sushil; Hu, Qing; Reno, John L.

    2005-01-01

    We report the demonstration of a terahertz quantum-cascade laser that operates up to 164 K in pulsed mode and 117 K in continuous-wave mod e at approximately 3.0 THz. The active region was based on a resonant -phonon depopulation scheme and a metal-metal waveguide was used for modal confinement. Copper to copper thermocompression wafer bonding w as used to fabricate the waveguide, which displayed improved thermal properties compared to a previous indium-gold bonding method.

  1. Continuous-variable quantum cloning of coherent states with phase-conjugate input modes using linear optics

    SciTech Connect

    Chen, Haixia; Zhang, Jing

    2007-02-15

    We propose a scheme for continuous-variable quantum cloning of coherent states with phase-conjugate input modes using linear optics. The quantum cloning machine yields M identical optimal clones from N replicas of a coherent state and N replicas of its phase conjugate. This scheme can be straightforwardly implemented with the setups accessible at present since its optical implementation only employs simple linear optical elements and homodyne detection. Compared with the original scheme for continuous-variable quantum cloning with phase-conjugate input modes proposed by Cerf and Iblisdir [Phys. Rev. Lett. 87, 247903 (2001)], which utilized a nondegenerate optical parametric amplifier, our scheme loses the output of phase-conjugate clones and is regarded as irreversible quantum cloning.

  2. High-power terahertz quantum cascade lasers with ˜0.23 W in continuous wave mode

    NASA Astrophysics Data System (ADS)

    Wang, Xuemin; Shen, Changle; Jiang, Tao; Zhan, Zhiqiang; Deng, Qinghua; Li, Weihua; Wu, Weidong; Yang, Ning; Chu, Weidong; Duan, Suqing

    2016-07-01

    Terahertz quantum cascade lasers with a record output power up to ˜0.23 W in continuous wave mode were obtained. We show that the optimal 2.9-mm-long device operating at 3.11 THz has a low threshold current density of 270 A/cm2 at ˜15 K. The maximum operating temperature arrived at ˜65 K in continuous wave mode and the internal quantum efficiencies decreased from 0.53 to 0.19 for the devices with different cavity lengths. By using one convex lens with the effective focal length of 13 mm, the beam profile was collimated to be a quasi Gaussian distribution.

  3. Cycling Versus Continuous Mode In Neuromodulator Programming: A Crossover, Randomized, Controlled Trial.

    PubMed

    Beer, Gwendolyn M; Gurule, Margaret M; Komesu, Yuko M; Qualls, Clifford R; Rogers, Rebecca G

    2016-01-01

    This is a randomized, controlled, blind, crossover trial comparing cycling versus continuous programming of a sacral neuromodulator in women diagnosed with overactive bladder (OAB). At 6 months, treatment order significantly affected Overactive Bladder Questionnaire - Short Form (OABq-SF) symptom scores. The cycling followed by continuous stimulation group had superior OABq-SF scores (p > 0.02). PMID:27501593

  4. A One Year Study of Mode Deactivation Therapy: Adolescent Residential Patients with Conduct and Personality Disorders

    ERIC Educational Resources Information Center

    Murphy, Christopher J.; Siv, Alexander M.

    2011-01-01

    This case study is to evaluate the effectiveness of Mode Deactivation Therapy (MDT) implementation in a child and adolescent residential treatment unit and provide preliminary effectiveness data on MDT versus treatment as usual (TAU). This case study compared the efficacy of two treatment methodologies for adolescent males in residential treatment…

  5. Continuous glucose monitoring microsensor with a nanoscale conducting matrix and redox mediator

    NASA Astrophysics Data System (ADS)

    Pesantez, Daniel

    The major limiting factor in kidney clinical transplantation is the shortage of transplantable organs. The current inability to distinguish viability from non-viability on a prospective basis represents a major obstacle in any attempt to expand organ donor criteria. Consequently, a way to measure and monitor a relevant analyte to assess kidney viability is needed. For the first time, the initial development and characterization of a metabolic microsensor to assess kidney viability is presented. The rate of glucose consumption appears to serve as an indicator of kidney metabolism that may distinguish reversible from irreversible kidney damage. The proposed MetaSense (Metabolic Sensor) microdevice would replace periodic laboratory diagnosis tests with a continuous monitor that provides real-time data on organ viability. Amperometry, a technique that correlates an electrical signal with analyte concentration, is used as a method to detect glucose concentrations. A novel two-electrode electrochemical sensing cell design is presented. It uses a modified metallic working electrode (WE) and a bare metallic reference electrode (RE) that acts as a pseudo-reference/counter electrode as well. The proposed microsensor has the potential to be used as a minimally invasive sensor for its reduced number of probes and very small dimensions achieved by micromachining and lithography. In order to improve selectivity of the microdevice, two electron transfer mechanisms or generations were explored. A first generation microsensor uses molecular oxygen as the electron acceptor in the enzymatic reaction and oxidizes hydrogen peroxide (H2O2) to get the electrical signal. The microsensor's modified WE with conductive polymer polypyrrole (PPy) and corresponding enzyme glucose oxidase (GOx) immobilized into its matrix, constitutes the electrochemical detection mechanism. Photoluminescence spectroscopic analysis confirmed and quantified enzyme immobilized concentrations within the matrix. In

  6. Thermal conductivity measurements of high and low thermal conductivity films using a scanning hot probe method in the 3ω mode and novel calibration strategies.

    PubMed

    Wilson, Adam A; Muñoz Rojo, Miguel; Abad, Begoña; Perez, Jaime Andrés; Maiz, Jon; Schomacker, Jason; Martín-Gonzalez, Marisol; Borca-Tasciuc, Diana-Andra; Borca-Tasciuc, Theodorian

    2015-10-01

    This work discusses measurement of thermal conductivity (k) of films using a scanning hot probe method in the 3ω mode and investigates the calibration of thermal contact parameters, specifically the thermal contact resistance (R(th)C) and thermal exchange radius (b) using reference samples with different thermal conductivities. R(th)C and b were found to have constant values (with b = 2.8 ± 0.3 μm and R(th)C = 44,927 ± 7820 K W(-1)) for samples with thermal conductivity values ranging from 0.36 W K(-1) m(-1) to 1.1 W K(-1) m(-1). An independent strategy for the calibration of contact parameters was developed and validated for samples in this range of thermal conductivity, using a reference sample with a previously measured Seebeck coefficient and thermal conductivity. The results were found to agree with the calibration performed using multiple samples of known thermal conductivity between 0.36 and 1.1 W K(-1) m(-1). However, for samples in the range between 16.2 W K(-1) m(-1) and 53.7 W K(-1) m(-1), calibration experiments showed the contact parameters to have considerably different values: R(th)C = 40,191 ± 1532 K W(-1) and b = 428 ± 24 nm. Finally, this work demonstrates that using these calibration procedures, measurements of both highly conductive and thermally insulating films on substrates can be performed, as the measured values obtained were within 1-20% (for low k) and 5-31% (for high k) of independent measurements and/or literature reports. Thermal conductivity results are presented for a SiGe film on a glass substrate, Te film on a glass substrate, polymer films (doped with Fe nano-particles and undoped) on a glass substrate, and Au film on a Si substrate. PMID:26335503

  7. Dual-Mode Combustion of Hydrogen in a Mach 5, Continuous-Flow Facility

    NASA Technical Reports Server (NTRS)

    Goyne, C. P.; McDaniel, J. C.; Quagliaroli, T. M.; Krauss, R. H.; Day, S. W.; Reubush, D. E. (Technical Monitor); McClinton, C. R. (Technical Monitor); Reubush, D. E.

    2001-01-01

    Results of an experimental and numerical study of a dual-mode scramjet combustor are reported. The experiment consisted of a direct-connect test of a Mach 2 hydrogen-air combustor with a single unswept-ramp fuel injector. The flow stagnation enthalpy simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and a particle-imaging laser diagnostic technique. The particle imaging was enabled through the development of a new apparatus for seeding fine silicon dioxide particles into the combustor fuel stream. Numerical simulations of the combustor were performed using the GASP code. The modeling, and much of the experimental work, focused on the supersonic combustion mode. Reasonable agreement was observed between experimental and numerical wall pressure distributions. However, the numerical model was unable to predict accurately the effects of combustion on the fuel plume size, penetration, shape, and axial growth.

  8. An intercomparison of continuous flow, and automatically segmenting rainwater collection methods for determining precipitation conductivity and pH

    NASA Astrophysics Data System (ADS)

    Laquer, Frederic C.

    This report compares two precipitation intensity or volume weighted rainwater collection methods. A continuous flow measurement of conductivity and pH is compared to the corresponding data for samples collected by a fraction collection system. Conductivity data from summer thunderstorms in Omaha, Nebraska, collected by the two systems are comparable to each other and with integrated collection by a wet-only, event collector. The flow system pH measurement exhibits bias with respect to the fraction collection system due to insufficient electrode equilibration time, especially when the precipitation conductivity is low, < 10 μS cm -1.

  9. Conductivity of styrene-butadiene block copolymers upon continuous irradiation with fast electrons

    SciTech Connect

    Khatipov, S.A.; Edrisov, A.T.; Bol`bit, N.M.; Milinchuk, V.K.

    1995-03-01

    The time dependences of the density of radiation-induced current in polystyrene, polybutadiene, and styrene-butadiene block copolymers of various composition were studied upon varying the electric field strength and radiation dose rate. Significant deviations of the values of the radiation-induced conductivity constant A{sub m} and dispersion parameter {alpha} from those expected for additive contributions of each component into the radiation-induced conductivity were revealed. Conclusions on the charge carriers generated during irradiation transfer from polybutadiene to polystyrene microdomains were drawn.

  10. 20 CFR 416.989 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989 We may conduct a review to find out...(s) from time to time to determine if you are still eligible for payments based on disability....

  11. 20 CFR 416.989 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989 We may conduct a review to find out...(s) from time to time to determine if you are still eligible for payments based on disability....

  12. 20 CFR 416.989 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989 We may conduct a review to find out...(s) from time to time to determine if you are still eligible for payments based on disability....

  13. 20 CFR 416.989 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989 We may conduct a review to find out...(s) from time to time to determine if you are still eligible for payments based on disability....

  14. 20 CFR 416.989 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989 We may conduct a review to find out...(s) from time to time to determine if you are still eligible for payments based on disability....

  15. 20 CFR 416.989a - We may conduct a review to find out whether you continue to be blind.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989a We may conduct a review to find out whether you... time to determine if you are still eligible for payments based on blindness. We call this evaluation...

  16. 20 CFR 416.989a - We may conduct a review to find out whether you continue to be blind.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989a We may conduct a review to find out whether you... time to determine if you are still eligible for payments based on blindness. We call this evaluation...

  17. 20 CFR 416.989a - We may conduct a review to find out whether you continue to be blind.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989a We may conduct a review to find out whether you... time to determine if you are still eligible for payments based on blindness. We call this evaluation...

  18. 20 CFR 416.989a - We may conduct a review to find out whether you continue to be blind.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989a We may conduct a review to find out whether you... time to determine if you are still eligible for payments based on blindness. We call this evaluation...

  19. 20 CFR 416.989a - We may conduct a review to find out whether you continue to be blind.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Continuing Or Stopping Disability Or Blindness § 416.989a We may conduct a review to find out whether you... time to determine if you are still eligible for payments based on blindness. We call this evaluation...

  20. USING CONTINUOUS MONITORS FOR CONDUCTING TRACER STUDIES IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The use of online monitors for conducting a distribution system tracer study is proving to be an essential tool to accurately understand the flow dynamics in a distribution system. In a series of field testing sponsored by U. S. Environmental Protection Agency (EPA) and Greater ...

  1. Influence of water conductivity on particular electrospray modes with dc corona discharge — optical visualization approach

    NASA Astrophysics Data System (ADS)

    Pongrác, Branislav; Kim, Hyun-Ha; Negishi, Nobuaki; Machala, Zdenko

    2014-08-01

    The effect of water conductivity on electrospraying of water was studied in combination with positive DC corona discharge generated in air. We used a point-to-plane geometry of electrodes with a hollow syringe needle anode opposite to the metal mesh cathode. We employed total average current measurements and high-speed camera fast time-resolved imaging. We visualized the formation of a water jet (filament) and investigated corona discharge behavior for various water conductivities. Depending on the conductivity, various jet properties were observed: pointy, prolonged, and fast spreading water filaments for lower conductivity; in contrast to rounder, broader, and shorter quickly disintegrating filaments for higher conductivity. The large acceleration values (4060 m/s2 and 520 m/s2 for 2 μS/cm and 400 μS/cm, respectively) indicate that the process is mainly governed by the electrostatic force. In addition, with increasing conductivity, the breakdown voltage for corona-to-spark transition was decreasing.

  2. Entanglement transfer from two-mode anti-correlated continuous-variable systems to a pair of localized discrete systems

    NASA Astrophysics Data System (ADS)

    Ran, Du; Yang, Zhen-Biao

    2016-04-01

    We address the entanglement transfer from a bipartite continuous-variable(CV) system to a pair of localized discrete systems. The dynamics behavior can be implemented by two two-level atoms flying through spatially separated identical cavities where two quantized modes are injected. We assume each CV mode couples to one atom via the resonant Jaynes-Cummings interaction. The CV systems are initially prepared in a two-mode anti-correlated SU(2) coherent state, while with the initial atomic states of the cases: |g⟩1|g⟩2, |e⟩1|e⟩2 and |g⟩1|e⟩2, respectively. We find that the entanglement transfer for single-photon excitation case is more efficient than that for multi-photon excitation case. Under same conditions, we also note that the entanglement transfer is more efficient for SU(2) coherent state than for twin-bean (TWB) and pair-coherent (TMC) state. Besides, we show that, for a given total photon number of the initial SU(2) coherent state, the efficiency of entanglement transfer depends upon the distribution of photons in the two CV modes. We also consider the influences of the dissipation and the white noise on the entanglement transfer.

  3. Application for continuation of mixed ionic and electronic conductivity in polymers

    SciTech Connect

    Shiver, D.F.; Ratner, M.A.

    1990-01-01

    The aim in this portion of the research is to prepare new electroactive films with high ion mobility, and to characterize the transport properties of these materials. The classic conducting polymers, polyacetylene, polythiophene, and polypyrrole have dense structures that prevent rapid redox switching because of the low diffusivity of ions. The objective is to modify the last two polymers with pendant polyethers, which should greatly improve ion transport.

  4. Anisotropy of conductivity in carbon fiber-reinforced plastics with continuous fibers

    NASA Astrophysics Data System (ADS)

    Ponomarenko, Anatoliy T.; Shevchenko, Vitaliy G.; Letyagin, Sergey V.; Klason, Carl

    1995-05-01

    Carbon fiber-reinforced plastics (CFRP), as high strength advanced materials are often used as media for embedding sensors and actuators. Due to the properties of components and processing conditions they are electrically anisotropic, with coefficient of anisotropy sometimes exceeding several thousands. This may prevent elimination of static electricity and cause erosion of material due to micro discharges at contacts with fastenings and embedded sensors and actuators, causing their malfunction. For this reason, the investigation of electrical properties of CFRP may provide the solution to this problem. Distribution of electric current field in CFRP and related with it possible errors in measurements of longitudinal conductivity and anisotropy are analyzed. CFRP have been prepared from PAN or cellulose fibers with different heat treatment temperatures and conductivity anisotropy was measured as a function of filler volume fraction and processing conditions. With increasing loading coefficient of anisotropy (alpha) decreases. Lower values of (alpha) were observed when curing agents containing ionic complexes of metals were used. Modifications of fiber surface with hydrophobic agents results in increased anisotropy. Composites prepared with carbon fabrics are isotropic in the fabric plane. Coefficient of anisotropy decreases with increasing molding pressure and depends on the type of weaving of fabric. In hybrid composites with alternating layers of carbon fabric and complex fiber fabric anisotropy is higher due to partial decomposition of conducting layer on top of complex fibers. A method for reducing anisotropy by introducing conducting `jumpers', shorting individual fibers or layers of fabric is proposed. The change of anisotropy in the process of fabrication of carbon-carbon composite by passing electric current through fibers has been investigated. In conclusion, alternative uses of CFRP with reduced anisotropy for contact elements of electric current through

  5. Anisotropic charge and heat conduction through arrays of parallel elliptic cylinders in a continuous medium

    NASA Astrophysics Data System (ADS)

    Martin, James E.; Ribaudo, Troy

    2013-04-01

    Arrays of circular pores in silicon can exhibit a phononic bandgap when the lattice constant is smaller than the phonon scattering length, and so have become of interest for use as thermoelectric materials, due to the large reduction in thermal conductivity that this bandgap can cause. The reduction in electrical conductivity is expected to be less, because the lattice constant of these arrays is engineered to be much larger than the electron scattering length. As a result, electron transport through the effective medium is well described by the diffusion equation, and the Seebeck coefficient is expected to increase. In this paper, we develop an expression for the purely diffusive thermal (or electrical) conductivity of a composite comprised of square or hexagonal arrays of parallel circular or elliptic cylinders of one material in a continuum of a second material. The transport parallel to the cylinders is straightforward, so we consider the transport in the two principal directions normal to the cylinders, using a self-consistent local field calculation based on the point dipole approximation. There are two limiting cases: large negative contrast (e.g., pores in a conductor) and large positive contrast (conducting pillars in air). In the large negative contrast case, the transport is only slightly affected parallel to the major axis of the elliptic cylinders but can be significantly affected parallel to the minor axis, even in the limit of zero volume fraction of pores. The positive contrast case is just the opposite: the transport is only slightly affected parallel to the minor axis of the pillars but can be significantly affected parallel to the major axis, even in the limit of zero volume fraction of pillars. The analytical results are compared to extensive FEA calculations obtained using Comsol™ and the agreement is generally very good, provided the cylinders are sufficiently small compared to the lattice constant.

  6. Optical and ionospheric phenomena at EISCAT under continuous X-mode HF pumping

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskaya, N. F.; Borisova, T. D.; Kosch, M.; Sergienko, T.; Brändström, U.; Yeoman, T. K.; Häggström, I.

    2014-12-01

    We present experimental results from multiinstrument observations in the high-latitude ionospheric F2 layer at the EISCAT (European Incoherent Scatter Scientific Association) heating facility. The results come from a set of experiments, when an X-polarized HF pump wave at high heater frequencies (fH > 6.0 MHz) was injected into the F region of the ionosphere toward the magnetic zenith. Experiments were carried out under quiet magnetic conditions with an effective radiated power of 458-548 MW. HF pumping was produced at different heater frequencies, away from electron gyroharmonic frequencies, and different durations of heater pulses. We show the first experimental evidence of the excitation of artificial optical emissions at red (630 nm) and green (557.7 nm) lines in the high-latitude ionospheric F2 layer induced by an X-polarized HF pump wave. Intensities at red and green lines varied in the range 110-950 R and 50-350 R, respectively, with a ratio of green to red line of 0.35-0.5. The results of optical observations are compared with behaviors of the HF-enhanced ion and plasma lines from EISCAT UHF incoherent scatter radar data and small-scale field-aligned artificial irregularities from Cooperative UK Twin Located Auroral Sounding System observations. It was found that the X-mode radio-induced optical emissions coexisted with HF-enhanced ion and plasma lines and strong artificial field-aligned irregularities throughout the whole heater pulse. It is indicative that parametric decay or oscillating two-stream instabilities were not quenched by fully established small-scale field-aligned artificial irregularities excited by an X-mode HF pump wave.

  7. Qualitative multiple-fault diagnosis of continuous dynamic systems using behavioral modes

    SciTech Connect

    Subramanian, S.; Mooney, R.J.

    1996-12-31

    Most model-based diagnosis systems, such as GDE and Sherlock, have concerned discrete, static systems such as logic circuits and use simple constraint propagation to detect inconsistencies. However, sophisticated systems such as QSIM and QPE have been developed for qualitative modeling and simulation of continuous dynamic systems. We present an integration of these two lines of research as implemented in a system called QDOCS for multiple-fault diagnosis of continuous dynamic systems using QSIM models. The main contributions of the algorithm include a method for propagating dependencies while solving a general constraint satisfaction problem and a method for verifying the consistency of a behavior with a model across time. Through systematic experiments on two realistic engineering systems, we demonstrate that QDOCS demonstrates a better balance of generality, accuracy, and efficiency than competing methods.

  8. The role of molar conductivity in electrospray cone-jet mode current scaling

    NASA Astrophysics Data System (ADS)

    Smith, Katharine L.; Alexander, Matthew S.; Stark, John P. W.

    2006-07-01

    A high accuracy online flow rate measurement system has been used to determine the current flow rate scaling relationships for solutions of organic solvents doped with sodium iodide and for the ionic liquid 1-ethyl-3-methyl imidazolium tetrafluoroborate over a range of conductivities from 0.0025-1.3S/m. The current flow rate trends for these solutions were found to exhibit a power law relationship similar to that described by previous researchers, where I (the electrospray current) is proportional to Q (the volumetric flow rate) to some power n. However, the exponent n of the current flow rate trends was found to differ from the theoretical predictions reported in the literature. A study including data from literature revealed the exponent of the current flow rate trends to be sensitive to the molar conductivity of the sprayed solution.

  9. Continuous Improvement of H-Mode Discharge Performance with Progressively Increasing Lithium Coatings in the National Spherical Torus Experiment

    SciTech Connect

    Maingi, Rajesh; Kaye, S.; Skinner, C. H.; Boyle, D. P.; Canik, John; Bell, M. G.; Bell, R. E.; Gray, Travis K; Jaworski, M. A.; Kaita, R.; Kugel, H. W.; LaBlanc, B. P.; Mansfield, D.K.; Osborne, T. H.; Sabbagh, S. A.; Soukhanovskii, V. A.

    2011-01-01

    Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on the amount of predischarge lithium evaporation.We observed a nearly monotonic reduction in recycling, decrease in electron transport, and modification of the edge profiles and stability with increasing lithium. These correlations challenge basic expectations, given that even the smallest coatings exceeded that needed for a nominal thickness of the order of the implantation range.

  10. Continuously phase-matched terahertz difference frequency generation in an embedded-waveguide structure supporting only fundamental modes.

    PubMed

    Staus, Chad; Kuech, Thomas; McCaughan, Leon

    2008-08-18

    We demonstrate an all-single mode structure which enables continuous phase matching of difference frequency generated THz light from the near-IR. This structure provides a long interaction length by way of well-confined collinear propagation of pumps and product without diffraction, resulting in high conversion efficiency. A LiNbO(3) version of this structure achieved a power-normalized conversion efficiency of 1.3 x 10(-7) W(-1)--some 23 times larger than the largest previously reported results. PMID:18711566

  11. Analytical model and new structure of the enhancement-mode polarization-junction HEMT with vertical conduction channel

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Xiong, Jiayun; Wei, Jie; Wu, Junfeng; Peng, Fu; Deng, Siyu; Zhang, Bo; Luo, Xiaorong

    2016-04-01

    A novel enhancement-mode (E-mode) polarization-junction HEMT with vertical conduction channel (PVC-HEMT) is proposed, and its analytical model for threshold voltage (Vth) is presented. It has two features: one is GaN/AlGaN/GaN double hetero-structure, the other is that source and drain locate at the same side of trench-type MOS gate (T-gate), and the source contacts with the T-gate, which forms vertical conduction channel (VC). The 2-D hole gas (2-DHG) and 2-D electron gas (2-DEG) are formed at the GaN-top/AlGaN and AlGaN/GaN-buffer interface, respectively, forming the polarization-junction. First, the E-mode operation is realized because 2-DHG under the source prevents the electrons injecting from source to 2-DEG, breaking through the conventional E-mode method by depleting 2-DEG under the gate. Second, a uniform electric field (E-field) distribution is achieved due to the assisted depletion effect by polarization-junction. Third, the source reduces the E-field peak at the T-gate side and modulates the E-field distribution. The breakdown voltage (BV) of PVC-HEMT is 705 V and specific ON-resistance (RON,sp) is 1.18 mΩ cm2. Compared with conventional HEMT (C-HEMT), PVC-HEMT has a smaller size due to the special location of the source and T-gate. An analytic threshold voltage model is presented and the analytical results agree well with the simulated results.

  12. Thermal conductivity measurements of high and low thermal conductivity films using a scanning hot probe method in the 3ω mode and novel calibration strategies

    NASA Astrophysics Data System (ADS)

    Wilson, Adam A.; Muñoz Rojo, Miguel; Abad, Begoña; Perez, Jaime Andrés; Maiz, Jon; Schomacker, Jason; Martín-Gonzalez, Marisol; Borca-Tasciuc, Diana-Andra; Borca-Tasciuc, Theodorian

    2015-09-01

    This work discusses measurement of thermal conductivity (k) of films using a scanning hot probe method in the 3ω mode and investigates the calibration of thermal contact parameters, specifically the thermal contact resistance (RthC) and thermal exchange radius (b) using reference samples with different thermal conductivities. RthC and b were found to have constant values (with b = 2.8 +/- 0.3 μm and Rthc = 44 927 +/- 7820 K W-1) for samples with thermal conductivity values ranging from 0.36 W K-1 m-1 to 1.1 W K-1 m-1. An independent strategy for the calibration of contact parameters was developed and validated for samples in this range of thermal conductivity, using a reference sample with a previously measured Seebeck coefficient and thermal conductivity. The results were found to agree with the calibration performed using multiple samples of known thermal conductivity between 0.36 and 1.1 W K-1 m-1. However, for samples in the range between 16.2 W K-1 m-1 and 53.7 W K-1 m-1, calibration experiments showed the contact parameters to have considerably different values: Rthc = 40 191 +/- 1532 K W-1 and b = 428 +/- 24 nm. Finally, this work demonstrates that using these calibration procedures, measurements of both highly conductive and thermally insulating films on substrates can be performed, as the measured values obtained were within 1-20% (for low k) and 5-31% (for high k) of independent measurements and/or literature reports. Thermal conductivity results are presented for a SiGe film on a glass substrate, Te film on a glass substrate, polymer films (doped with Fe nano-particles and undoped) on a glass substrate, and Au film on a Si substrate.This work discusses measurement of thermal conductivity (k) of films using a scanning hot probe method in the 3ω mode and investigates the calibration of thermal contact parameters, specifically the thermal contact resistance (RthC) and thermal exchange radius (b) using reference samples with different thermal

  13. Dual-mode ion switching conducting polymer films as high energy supercapacitor materials

    SciTech Connect

    Naoi, Katsuhiko; Oura, Yasushi

    1995-12-31

    The electropolymerized polypyrrole films formed from micellar solution of anionic surfactants, viz., Dodecylbenzene sulfonate (DBS), showed potential-dependent anion and cation ion switching behavior and the peculiar columnar structure. The formation process and the redox of the polypyrrole was studied with the in situ atomic force microscopy (AFM) and electrochemical quartz crystal microbalance (EQCM) methods. In-situ AFM observation clearly indicated that such a columnar structure started to form around critical charge densities of 60--100 mC cm{sup {minus}2}. The cyclic voltammogram for the PPy doped with DBS{sup {minus}} film showed two redox couples, each of which corresponds to a cation and an anion exchange process. Thus, the film behaves as a dual-mode ion doping/undoping exchanger. As the PPy film was prepared in higher concentration of the surfactant dopant, where the micelles are formed in solution, the resulting film showed a considerably higher (ca. three orders of magnitude) diffusion coefficient compared to ordinary PPy films so far reported. Such an enhanced diffusivity of ions could be attributed to a peculiar structure of the polymer formed. The feasibility of such polypyrrole in use of supercapacitor material was discussed.

  14. Strength and conductivity of unidirectional copper composites reinforced by continuous SiC fibers

    NASA Astrophysics Data System (ADS)

    Kimmig, S.; Allen, I.; You, J. H.

    2013-09-01

    A SiC long fiber-reinforced copper composite offers a beneficial combination of high strength and high thermal conductivity at elevated temperatures. Both properties make the composite a promising material for the heat sink of high-heat-flux components. In this work, we developed a novel Cu/SiCf composite using the Sigma fiber. Based on HIP technique, a metallurgical process was established for fabricating high quality specimens using a TiC interface coating. Extensive tensile tests were conducted on the unidirectionally reinforced composite at 20 °C and 300 °C for a wide range of fiber volume fraction (Vf). In this paper, a large amount of test data is presented. The transversal thermal conductivity varies from 260 to 130 W/mK at 500 °C as Vf is increased from 13% to 37%. The tensile strength reached up to 1246 MPa at 20 °C for Vf = 37.6%, where the fracture strain was limited to 0.8%. The data of both elastic modulus and ultimate strength exhibited a good agreement with the rule-of-mixture predictions indicating a high quality of the materials. The strength of the composite with the Sigma fibers turned out to be superior to those of the SCS6 fibers at 300 °C, although the SCS6 fiber actually has a higher strength than the Sigma fiber. The fractographic pictures of tension test and fiber push-out test manifested a sufficient interfacial bonding. Unidirectional copper composite reinforced by long SiC fibers was fabricated using the Sigma SM1140+ fiber for a wide range of fiber volume fraction from 14% to 40%. Extensive tensile tests were carried out at RT and 300 °C. The data of ultimate strength as well as elastic modulus exhibited a good agreement with the rule-of-mixture predictions indicating a high quality of the materials. In terms of the tensile strength, the Cu/Sigma composite turned out to be superior to the previous Cu/SCS6 composite at 300 °C, while comparable at RT, although the SCS6 fiber has a higher strength than the Sigma fiber. Such a

  15. Linewidth narrowing of a tunable mode-locked pumped continuous-wave Ce:LiCAF laser.

    PubMed

    Wellmann, Barbara; Kitzler, Ondrej; Spence, David J; Coutts, David W

    2015-07-01

    We report birefringent tuning using single and multiple magnesium fluoride (MgF(2)) Brewster tuning plates in a mode-locked pumped continuous-wave Ce:LiCAF laser. Depending on the thickness of the MgF(2) plates used, continuous tuning over a range of up to 13 nm from 284.5 to 297.5 nm with a full width at half-maximum linewidth of 14 pm (50 GHz) was achieved. By combining MgF(2) plates with etalons, the linewidth of the laser was narrowed down to 0.75 pm (2.7 GHz). This generated narrowband output is suitable for many applications in spectroscopy, cold-atom manipulation, and sensing. PMID:26125368

  16. Computation of the eddy-current modes of three-dimensional conducting bodies

    NASA Astrophysics Data System (ADS)

    Gabbay, Jonathan E.; Scott, Waymond R.

    2016-05-01

    Low-frequency electromagnetic induction (EMI) sensors are commonly used in subsurface detection applications because of their efficacy at detecting even small fragments of metal when they are buried near the surface. This efficacy can become a shortcoming when the detector is expected to locate specific classes of targets that are buried among metallic clutter. For these applications, broadband EMI sensors have shown considerable promise at being able to detect, classify and locate targets such as land mines, and discriminate between them and the clutter with low false-alarm rates. In such cases, where differentiating targets from clutter is a significant obstacle, detection strategies based on the discrete spectrum of relaxation frequencies (DSRF) have been shown to be highly effective. For such purposes, a dictionary of DSRF of targets of interest must be computed a priori. Several classes of targets such as sphere and rings have DSRF that can be derived analytically, however, in general, the DSRF must be computed numerically. Previously, numerical strategies have been presented for thin conducting shells and rotationaly symmetric targets. In this paper, we will present a strategy to compute the DSRF of arbitrary conducting targets using a null space free Jacobi Davidson iteration (NFJD).

  17. Continuous sensors for mode selective actuation and reception of waves for structural health monitoring of woven composite laminates

    NASA Astrophysics Data System (ADS)

    Kirikera, Goutham R.; Petculescu, Gabriela; Krishnaswamy, Sridhar; Achenbach, Jan D.

    2007-04-01

    The quantitative evaluation of damage in woven composites using mode selective excitation of Lamb waves is reported in this paper. PVDF (polyvinylidene fluoride) comb sensors are used to generate and detect a single plate mode. The top electrode is a single set of equidistant fingers connected in parallel to the same potential while the bottom electrode is kept at ground. First, a pair of such sensors is used to generate and detect a single plate mode. Group velocity changes of a wave packet traveling through the damaged area are used for quantitative damage estimation. Second, a new electrode configuration is used in order to improve the receiver signal. The proposed configuration referred to as continuous sensors, is used in structural health monitoring (SHM) for detection of growing cracks. Theoretical and experimental results are presented. In addition, an analog circuitry to actuate the structure at high frequency (~1MHz) based on energy tapped from a vibrating cantilever beam (~20Hz) is developed, towards a high-frequency energy-harvested SHM.

  18. Distributed computing strategies for processing of FT-ICR MS imaging datasets for continuous mode data visualization.

    PubMed

    Smith, Donald F; Schulz, Carl; Konijnenburg, Marco; Kilic, Mehmet; Heeren, Ron M A

    2015-03-01

    High-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry imaging enables the spatial mapping and identification of biomolecules from complex surfaces. The need for long time-domain transients, and thus large raw file sizes, results in a large amount of raw data ("big data") that must be processed efficiently and rapidly. This can be compounded by large-area imaging and/or high spatial resolution imaging. For FT-ICR, data processing and data reduction must not compromise the high mass resolution afforded by the mass spectrometer. The continuous mode "Mosaic Datacube" approach allows high mass resolution visualization (0.001 Da) of mass spectrometry imaging data, but requires additional processing as compared to feature-based processing. We describe the use of distributed computing for processing of FT-ICR MS imaging datasets with generation of continuous mode Mosaic Datacubes for high mass resolution visualization. An eight-fold improvement in processing time is demonstrated using a Dutch nationally available cloud service. PMID:25273594

  19. Butanol production by immobilised Clostridium acetobutylicum in repeated batch, fed-batch, and continuous modes of fermentation.

    PubMed

    Dolejš, Igor; Krasňan, Vladimír; Stloukal, Radek; Rosenberg, Michal; Rebroš, Martin

    2014-10-01

    Clostridium acetobutylicum immobilised in polyvinylalcohol, lens-shaped hydrogel capsules (LentiKats(®)) was studied for production of butanol and other products of acetone-butanol-ethanol fermentation. After optimising the immobilisation protocol for anaerobic bacteria, continuous, repeated batch, and fed-batch fermentations in repeated batch mode were performed. Using glucose as a substrate, butanol productivity of 0.41 g/L/h and solvent productivity of 0.63 g/L/h were observed at a dilution rate of 0.05 h(-1) during continuous fermentation with a concentrated substrate (60 g/L). Through the process of repeated batch fermentation, the duration of fermentation was reduced from 27.8h (free-cell fermentation) to 3.3h (immobilised cells) with a solvent productivity of 0.77 g/L/h (butanol 0.57 g/L/h). The highest butanol and solvent productivities of 1.21 and 1.91 g/L/h were observed during fed-batch fermentation operated in repeated batch mode with yields of butanol (0.15 g/g) and solvents (0.24 g/g), respectively, produced per gram of glucose. PMID:25108474

  20. Distributed computing strategies for processing of FT-ICR MS imaging datasets for continuous mode data visualization

    SciTech Connect

    Smith, Donald F.; Schulz, Carl; Konijnenburg, Marco; Kilic, Mehmet; Heeren, Ronald M.

    2015-03-01

    High-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry imaging enables the spatial mapping and identification of biomolecules from complex surfaces. The need for long time-domain transients, and thus large raw file sizes, results in a large amount of raw data (“big data”) that must be processed efficiently and rapidly. This can be compounded by largearea imaging and/or high spatial resolution imaging. For FT-ICR, data processing and data reduction must not compromise the high mass resolution afforded by the mass spectrometer. The continuous mode “Mosaic Datacube” approach allows high mass resolution visualization (0.001 Da) of mass spectrometry imaging data, but requires additional processing as compared to featurebased processing. We describe the use of distributed computing for processing of FT-ICR MS imaging datasets with generation of continuous mode Mosaic Datacubes for high mass resolution visualization. An eight-fold improvement in processing time is demonstrated using a Dutch nationally available cloud service.

  1. Continuous Carbon Nanotube-Ultrathin Graphite Hybrid Foams for Increased Thermal Conductivity and Suppressed Subcooling in Composite Phase Change Materials.

    PubMed

    Kholmanov, Iskandar; Kim, Jaehyun; Ou, Eric; Ruoff, Rodney S; Shi, Li

    2015-12-22

    Continuous ultrathin graphite foams (UGFs) have been actively researched recently to obtain composite materials with increased thermal conductivities. However, the large pore size of these graphitic foams has resulted in large thermal resistance values for heat conduction from inside the pore to the high thermal conductivity graphitic struts. Here, we demonstrate that the effective thermal conductivity of these UGF composites can be increased further by growing long CNT networks directly from the graphite struts of UGFs into the pore space. When erythritol, a phase change material for thermal energy storage, is used to fill the pores of UGF-CNT hybrids, the thermal conductivity of the UGF-CNT/erythritol composite was found to increase by as much as a factor of 1.8 compared to that of a UGF/erythritol composite, whereas breaking the UGF-CNT bonding in the hybrid composite resulted in a drop in the effective room-temperature thermal conductivity from about 4.1 ± 0.3 W m(-1) K(-1) to about 2.9 ± 0.2 W m(-1) K(-1) for the same UGF and CNT loadings of about 1.8 and 0.8 wt %, respectively. Moreover, we discovered that the hybrid structure strongly suppresses subcooling of erythritol due to the heterogeneous nucleation of erythritol at interfaces with the graphitic structures. PMID:26529570

  2. Closed-loop ARS mode for scanning ion conductance microscopy with improved speed and stability for live cell imaging applications

    NASA Astrophysics Data System (ADS)

    Jung, Goo-Eun; Noh, Hanaul; Shin, Yong Kyun; Kahng, Se-Jong; Baik, Ku Youn; Kim, Hong-Bae; Cho, Nam-Joon; Cho, Sang-Joon

    2015-06-01

    Scanning ion conductance microscopy (SICM) is an increasingly useful nanotechnology tool for non-contact, high resolution imaging of live biological specimens such as cellular membranes. In particular, approach-retract-scanning (ARS) mode enables fast probing of delicate biological structures by rapid and repeated approach/retraction of a nano-pipette tip. For optimal performance, accurate control of the tip position is a critical issue. Herein, we present a novel closed-loop control strategy for the ARS mode that achieves higher operating speeds with increased stability. The algorithm differs from that of most conventional (i.e., constant velocity) approach schemes as it includes a deceleration phase near the sample surface, which is intended to minimize the possibility of contact with the surface. Analysis of the ion current and tip position demonstrates that the new mode is able to operate at approach speeds of up to 250 μm s-1. As a result of the improved stability, SICM imaging with the new approach scheme enables significantly improved, high resolution imaging of subtle features of fixed and live cells (e.g., filamentous structures & membrane edges). Taken together, the results suggest that optimization of the tip approach speed can substantially improve SICM imaging performance, further enabling SICM to become widely adopted as a general and versatile research tool for biological studies at the nanoscale level.

  3. Electrically continuous graphene from single crystal copper verified by terahertz conductance spectroscopy and micro four-point probe.

    PubMed

    Buron, Jonas D; Pizzocchero, Filippo; Jessen, Bjarke S; Booth, Timothy J; Nielsen, Peter F; Hansen, Ole; Hilke, Michael; Whiteway, Eric; Jepsen, Peter U; Bøggild, Peter; Petersen, Dirch H

    2014-11-12

    The electrical performance of graphene synthesized by chemical vapor deposition and transferred to insulating surfaces may be compromised by extended defects, including for instance grain boundaries, cracks, wrinkles, and tears. In this study, we experimentally investigate and compare the nano- and microscale electrical continuity of single layer graphene grown on centimeter-sized single crystal copper with that of previously studied graphene films, grown on commercially available copper foil, after transfer to SiO2 surfaces. The electrical continuity of the graphene films is analyzed using two noninvasive conductance characterization methods: ultrabroadband terahertz time-domain spectroscopy and micro four-point probe, which probe the electrical properties of the graphene film on different length scales, 100 nm and 10 μm, respectively. Ultrabroadband terahertz time-domain spectroscopy allows for measurement of the complex conductance response in the frequency range 1-15 terahertz, covering the entire intraband conductance spectrum, and reveals that the conductance response for the graphene grown on single crystalline copper intimately follows the Drude model for a barrier-free conductor. In contrast, the graphene grown on commercial copper foil shows a distinctly non-Drude conductance spectrum that is better described by the Drude-Smith model, which incorporates the effect of preferential carrier backscattering associated with extended, electronic barriers with a typical separation on the order of 100 nm. Micro four-point probe resistance values measured on graphene grown on single crystalline copper in two different voltage-current configurations show close agreement with the expected distributions for a continuous 2D conductor, in contrast with previous observations on graphene grown on commercial copper foil. The terahertz and micro four-point probe conductance values of the graphene grown on single crystalline copper shows a close to unity correlation, in

  4. Dual-wavelength operation of continuous-wave and mode-locked erbium-doped fiber lasers

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Martinez-Rios, A.; Monzon-Hernandez, D.; Ibarra-Escamilla, B.; Kuzin, E. A.; Hernandez-Garcia, J. C.

    2012-06-01

    We study numerically and experimentally multiple-wavelength operation of an erbium-doped figure-eight fiber laser including a multiple-bandpass optical filter formed by two concatenated fiber tapers. Both continuous-wave and pulsed operations are considered. In the continuous-wave regime, stable long-term operation at multiple closely spaced wavelengths is only obtained if fine adjustments of the cavity losses are performed. Under these conditions, simultaneous lasing at up to four wavelengths separated by 1.5 nm was observed experimentally. Tunable single-wavelength operation over more than 20 nm is also observed in the continuous-wave regime. In the passive mode locking regime, numerical simulations indicate that mechanisms involving the filter losses and the nonlinear transmission characteristic of the NOLM contribute in principle to stabilize dual-wavelength operation, allowing less demanding cavity loss adjustments. In this regime, the problem of synchronization between the pulse trains generated at each wavelength adds an additional dimension to the problem. In presence of cavity dispersion, the pulses at each wavelength tend to be asynchronous if the wavelength separation is large, however they can be synchronous in the case of closely spaced wavelengths, if cross-phase modulation is able to compensate for the dispersion-induced walkoff. Experimentally, fundamental and 2nd-order harmonic mode locking was observed, characterized by the generation of noise-like pulses. Finally, a regime of multi-wavelength passive Q-switching was also observed. We believe that this work will be helpful to guide the design of multiple-wavelength fiber laser sources, which are attractive for a wide range of applications including Wavelength Division Multiplexing transmissions, signal processing and sensing.

  5. Ubiquitination switches EphA2 vesicular traffic from a continuous safeguard to a finite signalling mode

    PubMed Central

    Sabet, Ola; Stockert, Rabea; Xouri, Georgia; Brüggemann, Yannick; Stanoev, Angel; Bastiaens, Philippe I. H.

    2015-01-01

    Autocatalytic phosphorylation of receptor tyrosine kinases (RTKs) enables diverse, context-dependent responses to extracellular signals but comes at the price of autonomous, ligand-independent activation. Using a conformational biosensor that reports on the kinase activity of the cell guidance ephrin receptor type-A (EphA2) in living cells, we observe that autonomous EphA2 activation is suppressed by vesicular recycling and dephosphorylation by protein tyrosine phosphatases 1B (PTP1B) near the pericentriolar recycling endosome. This spatial segregation of catalytically superior PTPs from RTKs at the plasma membrane is essential to preserve ligand responsiveness. Ligand-induced clustering, on the other hand, promotes phosphorylation of a c-Cbl docking site and ubiquitination of the receptor, thereby redirecting it to the late endosome/lysosome. We show that this switch from cyclic to unidirectional receptor trafficking converts a continuous suppressive safeguard mechanism into a transient ligand-responsive signalling mode. PMID:26292967

  6. Comparison of High Rate Laser Ablation and Resulting Structures Using Continuous and Pulsed Single Mode Fiber Lasers

    NASA Astrophysics Data System (ADS)

    Knebel, T.; Streek, A.; Exner, H.

    This paper compares high rate laser ablation and resulting structures of aluminum by using both a continuous wave and a ns-pulsed single mode fiber laser of high average laser power. Two different scan technologies were applied for fast deflection of the laser beams. In this work, 2.5D laser processing was studied by using a high aperture galvanometer scanner with a maximum scan speed of 18 m/s. By contrast, considerably higher scan speeds up to 1,000 m/s were achieved by using the in-house developed polygon scanner system. The ablation rates and the processing rates per unit area were analyzed by means of the depths of line-scan ablation tracks and laser processed cavities. In addition, SEM photograph of the machining samples will be presented in order to evaluate the machining quality. Finally the feasibility of this high rate technology for industrial application is demonstrated by machining examples.

  7. Ubiquitination switches EphA2 vesicular traffic from a continuous safeguard to a finite signalling mode.

    PubMed

    Sabet, Ola; Stockert, Rabea; Xouri, Georgia; Brüggemann, Yannick; Stanoev, Angel; Bastiaens, Philippe I H

    2015-01-01

    Autocatalytic phosphorylation of receptor tyrosine kinases (RTKs) enables diverse, context-dependent responses to extracellular signals but comes at the price of autonomous, ligand-independent activation. Using a conformational biosensor that reports on the kinase activity of the cell guidance ephrin receptor type-A (EphA2) in living cells, we observe that autonomous EphA2 activation is suppressed by vesicular recycling and dephosphorylation by protein tyrosine phosphatases 1B (PTP1B) near the pericentriolar recycling endosome. This spatial segregation of catalytically superior PTPs from RTKs at the plasma membrane is essential to preserve ligand responsiveness. Ligand-induced clustering, on the other hand, promotes phosphorylation of a c-Cbl docking site and ubiquitination of the receptor, thereby redirecting it to the late endosome/lysosome. We show that this switch from cyclic to unidirectional receptor trafficking converts a continuous suppressive safeguard mechanism into a transient ligand-responsive signalling mode. PMID:26292967

  8. Continuous higher-order sliding mode control with time-varying gain for a class of uncertain nonlinear systems.

    PubMed

    Han, Yaozhen; Liu, Xiangjie

    2016-05-01

    This paper presents a continuous higher-order sliding mode (HOSM) control scheme with time-varying gain for a class of uncertain nonlinear systems. The proposed controller is derived from the concept of geometric homogeneity and super-twisting algorithm, and includes two parts, the first part of which achieves smooth finite time stabilization of pure integrator chains. The second part conquers the twice differentiable uncertainty and realizes system robustness by employing super-twisting algorithm. Particularly, time-varying switching control gain is constructed to reduce the switching control action magnitude to the minimum possible value while keeping the property of finite time convergence. Examples concerning the perturbed triple integrator chains and excitation control for single-machine infinite bus power system are simulated respectively to demonstrate the effectiveness and applicability of the proposed approach. PMID:26920085

  9. Continuous scanning of a time-reversed ultrasonically encoded optical focus by reflection-mode digital phase conjugation

    PubMed Central

    Suzuki, Yuta; Tay, Jian Wei; Yang, Qiang; Wang, Lihong V.

    2014-01-01

    Time-reversed ultrasonically encoded (TRUE) optical focusing in turbid media was previously implemented using both analog and digital phase conjugation. The digital approach, in addition to its large energy gain, can improve the focal intensity and resolution by iterative focusing. However, performing iterative focusing at each focal position can be time-consuming. Here, we show that by gradually moving the focal position, the TRUE focal intensity is improved, as in iterative focusing at a fixed position, and can be continuously scanned to image fluorescent targets in a shorter time. Also, our setup is the first demonstration of TRUE focusing using a digital phase conjugate mirror in reflection mode, which is more suitable for practical applications. PMID:24978506

  10. Negative ion rich plasmas in continuous and pulsed wave modes in a minimum-B magnetic field

    NASA Astrophysics Data System (ADS)

    Sahu, Debaprasad; Pandey, Shail; Aneja, Jyoti; Bhattacharjee, Sudeep

    2012-12-01

    Generation of hydrogen negative ion rich plasmas is investigated in continuous wave (CW) and pulse modulated (PM) wave modes of 2.45 GHz in a minimum-B magnetic field. The waves are launched directly into the plasma device and utilize wave particle resonances for high density plasma generation. In CW operation, the chamber is divided into two sections, namely, the source and downstream region, separated by a transverse magnetic field that allows only cold electrons (˜1 eV) into the downstream region helpful for the generation of negative ions. The H- density is measured by the second derivative beat method and is compared with the values obtained from a steady state model and the extracted current density. In the pulsed mode, temporal filtering generates negative ion rich plasmas in the afterglow phase. The H- density in the afterglow is estimated using saturation current ratio method and the results are compared with a time dependent model using particle balance equations. The essential idea in both the filtering techniques is to assist generation of negative ions and prevent its destruction by hot electrons.

  11. Adjoint sensitivity method for the downward continuation of the Earth's geomagnetic field through an electrically conducting mantle

    NASA Astrophysics Data System (ADS)

    Hagedoorn, J. M.; Martinec, Z.

    2012-12-01

    Recent models of the Earth's geomagnetic field at the core-mantle boundary (CMB) are based on satellite measurements and/or observatory data, which are mostly harmonically downward continued to the CMB. One aim of the upcoming satellite mission Swarm is to determine the three-dimensional distribution of electric conductivity of the Earth's mantle. On this background, we developed an adjoint sensitivity downward continuation approach that is capable to consider three-dimensional electric conductivity distributions. Martinec (Geophys. J. Int., 136, 1999) developed a time-domain spectral-finite element approach for the forward modelling of vector electromagnetic induction data as measured on ground-based magnetic observatory or by satellites. We design a new method to compute the sensitivity of the magnetic induction data to a magnetic field prescribed at the core-mantle boundary, which we term the adjoint sensitivity method. The forward and adjoint initial boundary-value problems, both solved in the time domain, are identical, except for the specification of prescribed boundary conditions. The respective boundary-value data are the measured X magnetic component for the forward method and the difference between the measured and predicted Z magnetic component for the adjoint method. The squares of the differences in Z magnetic component summed up over the time of observation and all spatial positions of observations determine the misfit. Then the sensitivities of observed data, i.e. the partial derivatives of the misfit with respect to the parameters characterizing the magnetic field at the core-mantle boundary, are obtained by the surface integral over the core-mantle boundary of the product of the adjoint solution multiplied by the time-dependent functions describing the time variability of magnetic field at the core-mantle boundary, and integrated over the time of observation. The time variability of boundary data is represented in terms of locally supported B

  12. Synchronized growth and neutral lipid accumulation in Chlorella sorokiniana FC6 IITG under continuous mode of operation.

    PubMed

    Kumar, Vikram; Muthuraj, Muthusivaramapandian; Palabhanvi, Basavaraj; Das, Debasish

    2016-01-01

    Synchronized growth and neutral lipid accumulation with high lipid productivity under mixotrophic growth of the strain Chlorella sorokiniana FC6 IITG was achieved via manipulation of substrates feeding mode and supplementation of lipid elicitors in the growth medium. Screening and optimization of lipid elicitors resulted in lipid productivity of 110.59mgL(-1)day(-1) under the combined effect of lipid inducers sodium acetate and sodium chloride. Fed-batch cultivation of the strain in bioreactor with intermittent feeding of limiting nutrients and lipid inducer resulted in maximum biomass and lipid productivity of 2.08 and 0.97gL(-1)day(-1) respectively. Further, continuous production of biomass with concomitant lipid accumulation was demonstrated via continuous feeding of BG11 media supplemented with lipid inducers sodium acetate and sodium chloride. The improved biomass and lipid productivity in chemostat was found to be 2.81 and 1.27gL(-1)day(-1) respectively operated at a dilution rate of 0.54day(-1). PMID:26575619

  13. Pressurised hot water extraction in continuous flow mode for thermolabile compounds: extraction of polyphenols in red onions.

    PubMed

    Liu, Jiayin; Sandahl, Margareta; Sjöberg, Per J R; Turner, Charlotta

    2014-01-01

    Extraction and analysis of labile compounds in complex sample matrices, such as plants, is often a big analytical challenge. In this work, the use of a "green and clean" pressurised hot water extraction (PHWE) approach performed in continuous flow mode is explored. Experimental data for extraction and degradation kinetics of selected compounds were utilised to develop a continuous flow extraction (CFE) method targeting thermolabile polyphenols in red onions, with detection by high-performance liquid chromatography (HPLC)-diode array detection (DAD)-mass spectrometry (MS). Water containing ethanol and formic acid was used as extraction solvent. Method performance was focused on extraction yield with minimal analyte degradation. By adjusting the flow rate of the extraction solvent, degradation effects were minimised, and complete extraction could be achieved within 60 min. The CFE extraction yields of the polyphenols investigated were 80-90 % of the theoretically calculated quantitative yields and were significantly higher than the yields obtained by conventional methanol extraction and static batch extraction (70-79 and 58-67 % of the theoretical yields, respectively). The precision of the developed method was lower than 8 % expressed as relative standard deviation. PMID:24091739

  14. Transport properties of dense fluid mixtures using nonequilibrium molecular dynamics. [Viscosity and thermal conductivity of continuous, or polydisperse mixtures

    SciTech Connect

    Murad, S.

    1990-09-01

    This progress report covers research carried out during the period September 15, 1987--September 15, 1990. The main emphasis of the work was on dense fluid mixtures, although in some cases work had to be done on pure fluids before we could study mixtures in a meaningful way. A summary of our results is given. (1) An algorithm was developed and used to calculate the viscosity and thermal conductivity of continuous, or polydisperse mixtures with various distributions (e.g. linear, several gaussian distributions including unsymmetric, etc.) using nonequilibrium molecular dynamics (NEMD). (2) A method was developed to calculate the thermal conductivity of nonspherical (rigid) molecules using NEMD. (3) The NEMD method for thermal conductivity of nonspherical molecules was used to have a careful look at the contributions due to internal rotational degrees of freedom in linear compounds such as chlorine, nitrogen, etc. (4) It has long been speculated that polar fluids exhibit heat induced birefringence, i.e., the molecules will tend to align themselves along the direction of an external heat field. Using nonequilibrium molecular dynamics we were able to conclusively confirm this. (5) We completed a preliminary study of the viscosity of homonuclear diatomics and their mixtures (e.g. N{sub 2}, Cl{sub 2}, etc.). (6) We completed a study of the various flexibility (vibrational) effects, such as bond bending, bond stretching etc., on linear and nonlinear model triatomics. To examine these effects in our preliminary study, we looked at the pressure second virial coefficients.

  15. Atomistic simulations of ammonium-based protic ionic liquids: steric effects on structure, low frequency vibrational modes and electrical conductivity.

    PubMed

    Sunda, Anurag Prakash; Mondal, Anirban; Balasubramanian, Sundaram

    2015-02-14

    Protic ionic liquids (PILs) are of great interest as electrolytes in various energy applications. Molecular dynamics simulations of trialkylammonium (with varying alkyl group such as methyl, ethyl, and n-propyl) triflate PILs are performed to characterize the influence of the alkyl group on the acidic site (N-H) of the ammonium cation. Spatial distribution function of anions over this site on the cation reveals significant influence of the length of alkyl tail on intermolecular structure. Vibrational density of states and normal modes are calculated for bulk liquids to probe atomic displacements in the far infrared region. The observed N-H···O hydrogen bond stretching vibration in 155-165 cm(-1) frequency region agrees well with experiments. Trends in electrical conductivity calculated using Nernst-Einstein and Green-Kubo relation are in qualitative agreement with experiments. The self-diffusion coefficient and the electrical conductivity is highest for N,N-dimethyl-N-ethylammonium triflate ([N112][TfO]) and is lowest for N,N-di-n-propyl-N-methylammonium triflate ([N133][TfO]) IL. PMID:25585541

  16. Lower Energy Endovenous Laser Ablation of the Great Saphenous Vein with 980 nm Diode Laser in Continuous Mode

    SciTech Connect

    Kim, Hyun S. Nwankwo, Ikechi J.; Hong, Kelvin; McElgunn, Patrick S.J.

    2006-02-15

    Purpose. To assess clinical outcomes, complication rates, and unit energy applied using 980 nm diode endovenous laser treatment at 11 watts for symptomatic great saphenous vein (GSV) incompetence and reflux disease. Methods. Thirty-four consecutive ablation therapies with a 980 nm diode endovenous laser at 11 watts were studied. The diagnosis of GSV incompetence with reflux was made by clinical evaluation and duplex Doppler examinations. The treated GSVs had a mean diameter of 1.19 cm (range 0.5-2.2 cm). The patients were followed with clinical evaluation and color flow duplex studies up to 18.5 months (mean 12.19 months {+-} 4.18). Results. Using 980 nm diode endovenous laser ablation in continuous mode, 100% technical success was noted. The mean length of GSVs treated was 33.82 cm (range 15-45 cm). The mean energy applied during the treatment was 1,155.81 joules (J) {+-} 239.50 (range 545.40-1620 J) for a mean treatment duration of 90.77 sec {+-} 21.77. The average laser fiber withdrawal speed was 0.35 cm/sec {+-} 0.054. The mean energy applied per length of GSV was 35.16 J/cm {+-} 8.43. Energy fluence, calculated separately for each patient, averaged 9.82 J/cm{sup 2} {+-} 4.97. At up to 18.5 months follow-up (mean 12.19 months), 0% recanalization was noted; 92% clinical improvement was achieved. There was no major complication. Minor complications included 1 patient with hematoma at the percutaneous venotomy site, 1 patient with thrombophlebitis on superficial tributary varices of the treated GSV, 24% ecchymoses, and 32% self-limiting hypersensitivity/tenderness/'pulling' sensation along the treatment area. One patient developed temporary paresthesia. Four endovenous laser ablation treatments (12%) were followed by adjunctive sclerotherapies for improved cosmetic results. Conclusion. Endovenous laser ablation treatment of GSV using a 980 nm diode laser at 11 watts in continuous mode appears safe and effective. Mean energy applied per treated GSV length of 35

  17. Effect of conductivity and concentration on the sample stream in the transverse axis of a continuous flow electrophoresis chamber

    NASA Technical Reports Server (NTRS)

    Miller, Teresa Y.; Williams, George O.; Snyder, Robert S.

    1985-01-01

    The resolution of continuous flow electrophoresis systems is generally measured by the spread of the sample bands in the direction of the electrophoretic migration. This paper evaluates the cross section of the sample bands in the plane perpendicular to the flow and shows that the spread in the direction perpendicular to the migration increased significantly with the applied electric field. Concentrated samples of monodisperse latex particles and vinyltoluene T-butylstyrene particles in sample buffers of different electrical conductivities were used to map the shape of the sample bands relative to the zero electric field case. As the electric field was applied, the sample band spread from an initial diameter of only one-third the chamber thickness until it approached the chamber walls where electroosmosis significantly reduced the resolution of separation. It can be shown, however, that it is possible to minimize these distortions by careful sample preparation and experiment design.

  18. Evidence of Thermal Conduction Suppression in a Solar Flaring Loop by Coronal Seismology of Slow-mode Waves

    NASA Astrophysics Data System (ADS)

    Wang, Tongjiang; Ofman, Leon; Sun, Xudong; Provornikova, Elena; Davila, Joseph M.

    2015-09-01

    Analysis of a longitudinal wave event observed by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory is presented. A time sequence of 131 Å images reveals that a C-class flare occurred at one footpoint of a large loop and triggered an intensity disturbance (enhancement) propagating along it. The spatial features and temporal evolution suggest that a fundamental standing slow-mode wave could be set up quickly after meeting of two initial disturbances from the opposite footpoints. The oscillations have a period of ˜12 minutes and a decay time of ˜9 minutes. The measured phase speed of 500 ± 50 km s‑1 matches the sound speed in the heated loop of ˜10 MK, confirming that the observed waves are of slow mode. We derive the time-dependent temperature and electron density wave signals from six AIA extreme-ultraviolet channels, and find that they are nearly in phase. The measured polytropic index from the temperature and density perturbations is 1.64 ± 0.08 close to the adiabatic index of 5/3 for an ideal monatomic gas. The interpretation based on a 1D linear MHD model suggests that the thermal conductivity is suppressed by at least a factor of 3 in the hot flare loop at 9 MK and above. The viscosity coefficient is determined by coronal seismology from the observed wave when only considering the compressive viscosity dissipation. We find that to interpret the rapid wave damping, the classical compressive viscosity coefficient needs to be enhanced by a factor of 15 as the upper limit.

  19. A new mode of community continuing care service for COPD patients in China: participation of respiratory nurse specialists

    PubMed Central

    Li, Pingdong; Gong, Yucui; Zeng, Guangqiao; Ruan, Liang; Li, Guifen

    2015-01-01

    Objective: This study explored a community nursing service mode in which respiratory nurse specialists cared for patients with chronic obstructive pulmonary disease (COPD) in a 12-week period after hospital discharge, with the aim of better preventing acute exacerbations, improving health-related quality of life (HRQOL) and reducing medical expenses in these patients. Methods: We carried out a prospective randomized controlled study in which 68 COPD patients discharged were recruited from a general hospital in Guangzhou, China, were randomized divided into two groups. The control group underwent conventional nursing care, and the intervention group received community continuing care by respiratory nurse specialists. The observation period was 12 weeks. The results of intervention were evaluated using the Seattle Obstructive Lung Disease Questionnaire (SOLDQ) and the COPD Self-Efficacy Scale (CSES). In addition, the frequency of acute exacerbations, emergency treatments or hospitalizations, and medical expenses were recorded in the 12-week observation period. Results: After six weeks, the total and subscale scores (P < 0.05) of SOLDQ and CSES significantly improved compared to the baseline ones in the intervention group. The control group had significantly higher scores in the treatment satisfaction (TS) of SOLDQ, the total score, and the weather/environment and behavioral risk factors of CSES. After 12 weeks, the total and subscale scores of SOLDQ and CSES showed a sustained and significant growth in the intervention group (P < 0.05). The control group had significantly higher scores only in the weather/environment risk factor of CSES. During the 12-week observation, the intervention group had significantly fewer acute exacerbations, emergency treatments or re-hospitalizations and significantly lower average medical expenses than the control group (P < 0.05). Conclusions: Community continuing care by respiratory nurse specialists may improve HRQOL, increase self

  20. A diode-end-pumped continuous-wave single-longitudinal-mode Nd:GdV O4-LBO red laser at 670 nm

    NASA Astrophysics Data System (ADS)

    Wang, Y. T.; Zhang, R. H.; Li, J. H.; Li, W. J.; Tan, C.; Zhang, B. L.

    2014-03-01

    A diode-end-pumped continuous-wave single-longitudinal-mode intracavity frequency-doubling Nd:GdV O4-LBO (lithium triborate) red laser at 670 nm is reported. A ring cavity was designed to enable single-longitudinal-mode operation of the laser. By optimizing the mode-to-pump ratio taking account of the influence of the laser beam radius inside the frequency-doubling crystal LBO on the frequency-doubling efficiency for the special cavity, a maximum output power of 1.3 W for a continuous-wave single-longitudinal-mode red laser at 670 nm was obtained, and the measured power stability was better than ±1.2% in 2 h. The experimental results are in good agreement with the theoretical calculation.

  1. Extracting the regional common-mode component of GPS station position time series from dense continuous network

    NASA Astrophysics Data System (ADS)

    Tian, Yunfeng; Shen, Zheng-Kang

    2016-02-01

    We develop a spatial filtering method to remove random noise and extract the spatially correlated transients (i.e., common-mode component (CMC)) that deviate from zero mean over the span of detrended position time series of a continuous Global Positioning System (CGPS) network. The technique utilizes a weighting scheme that incorporates two factors—distances between neighboring sites and their correlations of long-term residual position time series. We use a grid search algorithm to find the optimal thresholds for deriving the CMC that minimizes the root-mean-square (RMS) of the filtered residual position time series. Comparing to the principal component analysis technique, our method achieves better (>13% on average) reduction of residual position scatters for the CGPS stations in western North America, eliminating regional transients of all spatial scales. It also has advantages in data manipulation: less intervention and applicable to a dense network of any spatial extent. Our method can also be used to detect CMC irrespective of its origins (i.e., tectonic or nontectonic), if such signals are of particular interests for further study. By varying the filtering distance range, the long-range CMC related to atmospheric disturbance can be filtered out, uncovering CMC associated with transient tectonic deformation. A correlation-based clustering algorithm is adopted to identify stations cluster that share the common regional transient characteristics.

  2. Towards cooperative guidance and control of highly automated vehicles: H-Mode and Conduct-by-Wire.

    PubMed

    Flemisch, Frank Ole; Bengler, Klaus; Bubb, Heiner; Winner, Hermann; Bruder, Ralph

    2014-01-01

    This article provides a general ergonomic framework of cooperative guidance and control for vehicles with an emphasis on the cooperation between a human and a highly automated vehicle. In the twenty-first century, mobility and automation technologies are increasingly fused. In the sky, highly automated aircraft are flying with a high safety record. On the ground, a variety of driver assistance systems are being developed, and highly automated vehicles with increasingly autonomous capabilities are becoming possible. Human-centred automation has paved the way for a better cooperation between automation and humans. How can these highly automated systems be structured so that they can be easily understood, how will they cooperate with the human? The presented research was conducted using the methods of iterative build-up and refinement of framework by triangulation, i.e. by instantiating and testing the framework with at least two derived concepts and prototypes. This article sketches a general, conceptual ergonomic framework of cooperative guidance and control of highly automated vehicles, two concepts derived from the framework, prototypes and pilot data. Cooperation is exemplified in a list of aspects and related to levels of the driving task. With the concept 'Conduct-by-Wire', cooperation happens mainly on the guidance level, where the driver can delegate manoeuvres to the automation with a specialised manoeuvre interface. With H-Mode, a haptic-multimodal interaction with highly automated vehicles based on the H(orse)-Metaphor, cooperation is mainly done on guidance and control with a haptically active interface. Cooperativeness should be a key aspect for future human-automation systems. Especially for highly automated vehicles, cooperative guidance and control is a research direction with already promising concepts and prototypes that should be further explored. The application of the presented approach is every human-machine system that moves and includes high

  3. Entanglement transfer from two-mode continuous variable SU(2) cat states to discrete qubits systems in Jaynes-Cummings Dimers

    PubMed Central

    Ran, Du; Hu, Chang-Sheng; Yang, Zhen-Biao

    2016-01-01

    We study the entanglement transfer from a two-mode continuous variable system (initially in the two-mode SU(2) cat states) to a couple of discrete two-state systems (initially in an arbitrary mixed state), by use of the resonant Jaynes-Cummings (JC) interaction. We first quantitatively connect the entanglement transfer to non-Gaussianity of the two-mode SU(2) cat states and find a positive correlation between them. We then investigate the behaviors of the entanglement transfer and find that it is dependent on the initial state of the discrete systems. We also find that the largest possible value of the transferred entanglement exhibits a variety of behaviors for different photon number as well as for the phase angle of the two-mode SU(2) cat states. We finally consider the influences of the noise on the transferred entanglement. PMID:27553881

  4. Entanglement transfer from two-mode continuous variable SU(2) cat states to discrete qubits systems in Jaynes-Cummings Dimers.

    PubMed

    Ran, Du; Hu, Chang-Sheng; Yang, Zhen-Biao

    2016-01-01

    We study the entanglement transfer from a two-mode continuous variable system (initially in the two-mode SU(2) cat states) to a couple of discrete two-state systems (initially in an arbitrary mixed state), by use of the resonant Jaynes-Cummings (JC) interaction. We first quantitatively connect the entanglement transfer to non-Gaussianity of the two-mode SU(2) cat states and find a positive correlation between them. We then investigate the behaviors of the entanglement transfer and find that it is dependent on the initial state of the discrete systems. We also find that the largest possible value of the transferred entanglement exhibits a variety of behaviors for different photon number as well as for the phase angle of the two-mode SU(2) cat states. We finally consider the influences of the noise on the transferred entanglement. PMID:27553881

  5. Ohio State Continuing Education: Shaping Its Future. 1992 Student Study Conducted by the Department of Credit Programs, Office of Continuing Education.

    ERIC Educational Resources Information Center

    Hanniford, Barbara E.; Ventresca, Carol A.

    A random sample of 700 current and former continuing education (CE) students were surveyed by mail in May 1992 to identify ways to improve programs and services. Responses from 333 confirmed that CE enrolled a diverse group of students. They chose Ohio State University primarily for its location and program availability. Almost 40 percent of the…

  6. Splitting of the zero-bias conductance peak as smoking gun evidence for the existence of the Majorana mode in a superconductor-semiconductor nanowire

    NASA Astrophysics Data System (ADS)

    Das Sarma, S.; Sau, Jay D.; Stanescu, Tudor D.

    2012-12-01

    Recent observations of a zero-bias conductance peak in tunneling transport measurements in superconductor-semiconductor nanowire devices provide evidence for the predicted zero-energy Majorana modes, but not the conclusive proof of their existence. We establish that direct observation of a splitting of the zero-bias conductance peak can serve as the smoking gun evidence for the existence of the Majorana mode. We show that the splitting has an oscillatory dependence on the Zeeman field (chemical potential) at fixed chemical potential (Zeeman field). By contrast, when the density is constant rather than the chemical potential—the likely situation in the current experimental setups—the splitting oscillations are generically suppressed. Our theory predicts the conditions under which the splitting oscillations can serve as the smoking gun for the experimental confirmation of the elusive Majorana mode.

  7. Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake: Data collection/analysis techniques

    NASA Technical Reports Server (NTRS)

    Hall, David G.; Heidelberg, Laurence; Konno, Kevin

    1993-01-01

    The rotating microphone measurement technique and data analysis procedures are documented which are used to determine circumferential and radial acoustic mode content in the inlet of the Advanced Ducted Propeller (ADP) model. Circumferential acoustic mode levels were measured at a series of radial locations using the Doppler frequency shift produced by a rotating inlet microphone probe. Radial mode content was then computed using a least squares curve fit with the measured radial distribution for each circumferential mode. The rotating microphone technique is superior to fixed-probe techniques because it results in minimal interference with the acoustic modes generated by rotor-stator interaction. This effort represents the first experimental implementation of a measuring technique developed by T. G. Sofrin. Testing was performed in the NASA Lewis Low Speed Anechoic Wind Tunnel at a simulated takeoff condition of Mach 0.2. The design is included of the data analysis software and the performance of the rotating rake apparatus. The effect of experiment errors is also discussed.

  8. Continuous wave ultraviolet light-induced fiber Bragg gratings in few- and single-mode microstructured polymer optical fibers.

    PubMed

    Dobb, Helen; Webb, David J; Kalli, Kyriacos; Argyros, Alexander; Large, Maryanne C J; van Eijkelenborg, Martijn A

    2005-12-15

    We report observations and measurements of the inscription of fiber Bragg gratings (FBGs) in two different types of microstructured polymer optical fiber: few-mode and an endlessly single mode. Contrary to the FBG inscription in silica microstructured fiber, where high-energy laser pulses are a prerequisite, we have successfully used a low-power cw laser source operating at 325 nm to produce 1 cm long gratings with a reflection peak at 1570 nm. Peak reflectivities of more than 10% have been observed. PMID:16389810

  9. A 15.1 W continuous wave TEM00 mode laser using a YVO4/Nd:YVO4 composite crystal

    NASA Astrophysics Data System (ADS)

    Zhao, Z.; Dong, Y.; Liu, C.; Hu, M.; Xiang, Z.; Ge, J.; Chen, J.

    2009-11-01

    A effective continuous-wave (CW), high power laser generated using a YVO4/Nd:YVO4 composite crystal is presented. 18.8 W output power in multi-mode has been achieved with a maximum absorbed pump power of 31.2 W, corresponding to an optical-to-optical efficiency of 60.26%. In TEM00 mode operation, 15.1 W output power also has been achieved with the maximum absorbed pump power of 31.2 W, corresponding to an optical-to-optical efficiency of 47.69%. With a 200 mm focal-length positive lens and using the moving knife-edge method, the beam quality factor is measured to be M2 = 1.2 for TEM00 mode beam.

  10. 20 CFR 404.1589 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... you continue to be disabled. 404.1589 Section 404.1589 Employees' Benefits SOCIAL SECURITY... disabled. After we find that you are disabled, we must evaluate your impairment(s) from time to time to... disabled....

  11. 20 CFR 404.1589 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... you continue to be disabled. 404.1589 Section 404.1589 Employees' Benefits SOCIAL SECURITY... disabled. After we find that you are disabled, we must evaluate your impairment(s) from time to time to... disabled....

  12. 20 CFR 404.1589 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... you continue to be disabled. 404.1589 Section 404.1589 Employees' Benefits SOCIAL SECURITY... disabled. After we find that you are disabled, we must evaluate your impairment(s) from time to time to... disabled....

  13. 20 CFR 404.1589 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... you continue to be disabled. 404.1589 Section 404.1589 Employees' Benefits SOCIAL SECURITY... disabled. After we find that you are disabled, we must evaluate your impairment(s) from time to time to... disabled....

  14. 20 CFR 404.1589 - We may conduct a review to find out whether you continue to be disabled.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... you continue to be disabled. 404.1589 Section 404.1589 Employees' Benefits SOCIAL SECURITY... disabled. After we find that you are disabled, we must evaluate your impairment(s) from time to time to... disabled....

  15. Mode-locking operation of quasi-continuous diode pumped TGT-grown Nd,Y-codoped:SrF2 crystal

    NASA Astrophysics Data System (ADS)

    Jelínek, Michal; Kubeček, Václav; Su, Liangbi; Jiang, Dapeng; Ma, Fengkai; Zhang, Qian; Cao, Yuexin; Xu, Jun

    2015-01-01

    Fluoride-type crystals (CaF2, SrF2) doped with neodymium Nd3+ present interesting alternative as a laser active media for the diode-pumped mode-locked laser systems mainly because of their broad emission spectra as well as longer fluorescence lifetime in comparison with well-known materials as Nd:YAG or Nd:YVO4. In comparison with Nd:glass active material, SrF2 and CaF2 have better thermal conductivity. In spite of the thermal conductivity decreases with doping concentration, these crystal might be interesting alternative for the Nd:glass mode-locked laser systems. In this contribution we present the first results of the Nd,Y:SrF2 mode-locked laser diode-pumped at 796nm. Mode-locking operation using SESAM was successfully achieved in the pulsed pumping regime (pulse-duration 1.5 ms, frequency 10 Hz) with the overall average output power of 2.3 mW (corresponding to the power amplitude of 153 mW) in one output beam at the wavelength of ~1055 nm. The actual pulse-duration was 87 ps.

  16. Continuous variable methods in relativistic quantum information: characterization of quantum and classical correlations of scalar field modes in noninertial frames

    NASA Astrophysics Data System (ADS)

    Adesso, Gerardo; Ragy, Sammy; Girolami, Davide

    2012-11-01

    We review a recently introduced unified approach to the analytical quantification of correlations in Gaussian states of bosonic scalar fields by means of Rényi-2 entropy. This allows us to obtain handy formulae for classical, quantum, total correlations, as well as bipartite and multipartite entanglement. We apply our techniques to the study of correlations between two modes of a scalar field as described by observers in different states of motion. When one or both observers are in uniform acceleration, the quantum and classical correlations are degraded differently by the Unruh effect, depending on which mode is detected. Residual quantum correlations, in the form of quantum discord without entanglement, may survive in the limit of an infinitely accelerated observer Rob, provided they are revealed in a measurement performed by the inertial Alice.

  17. Readout circuitry for continuous high-rate photon detection with arrays of InP Geiger-mode avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Frechette, Jonathan; Grossmann, Peter J.; Busacker, David E.; Jordy, George J.; Duerr, Erik K.; McIntosh, K. Alexander; Oakley, Douglas C.; Bailey, Robert J.; Ruff, Albert C.; Brattain, Michael A.; Funk, Joseph E.; MacDonald, Jason G.; Verghese, Simon

    2012-06-01

    An asynchronous readout integrated circuit (ROIC) has been developed for hybridization to a 32x32 array of single-photon sensitive avalanche photodiodes (APDs). The asynchronous ROIC is capable of simultaneous detection and readout of photon times of arrival, with no array blind time. Each pixel in the array is independently operated by a finite state machine that actively quenches an APD upon a photon detection event, and re-biases the device into Geiger mode after a programmable hold-off time. While an individual APD is in hold-off mode, other elements in the array are biased and available to detect photons. This approach enables high pixel refresh frequency (PRF), making the device suitable for applications including optical communications and frequency-agile ladar. A built-in electronic shutter that de-biases the whole array allows the detector to operate in a gated mode or allows for detection to be temporarily disabled. On-chip data reduction reduces the high bandwidth requirements of simultaneous detection and readout. Additional features include programmable single-pixel disable, region of interest processing, and programmable output data rates. State-based on-chip clock gating reduces overall power draw. ROIC operation has been demonstrated with hybridized InP APDs sensitive to 1.06-μm and 1.55-μm wavelength, and fully packaged focal plane arrays (FPAs) have been assembled and characterized.

  18. Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

    NASA Astrophysics Data System (ADS)

    Vecchiola, Aymeric; Chrétien, Pascal; Delprat, Sophie; Bouzehouane, Karim; Schneegans, Olivier; Seneor, Pierre; Mattana, Richard; Tatay, Sergio; Geffroy, Bernard; Bonnassieux, Yvan; Mencaraglia, Denis; Houzé, Frédéric

    2016-06-01

    An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10 decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes.

  19. 20 CFR 220.186 - When and how often the Board will conduct a continuing disability review.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Substantial Gainful Activity or Medical Improvement § 220.186 When and how often the Board will conduct a... benefits or a period of disability ends if the medical or other evidence shows that the annuitant is not... disability review will be started if— (1) The annuitant has been scheduled for a medical improvement...

  20. 20 CFR 220.186 - When and how often the Board will conduct a continuing disability review.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Substantial Gainful Activity or Medical Improvement § 220.186 When and how often the Board will conduct a... benefits or a period of disability ends if the medical or other evidence shows that the annuitant is not... disability review will be started if— (1) The annuitant has been scheduled for a medical improvement...

  1. 20 CFR 220.186 - When and how often the Board will conduct a continuing disability review.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Substantial Gainful Activity or Medical Improvement § 220.186 When and how often the Board will conduct a... benefits or a period of disability ends if the medical or other evidence shows that the annuitant is not... disability review will be started if— (1) The annuitant has been scheduled for a medical improvement...

  2. Detection of two-mode compression and degree of entanglement in continuous variables in parametric scattering of light

    SciTech Connect

    Rytikov, G. O.; Chekhova, M. V.

    2008-12-15

    Generation of 'twin beams' (of light with two-mode compression) in single-pass optical parametric amplifier (a crystal with a nonzero quadratic susceptibility) is considered. Radiation at the output of the nonlinear crystal is essentially multimode, which raises the question about the effect of the detection volume on the extent of suppression of noise from the difference photocurrent of the detectors. In addition, the longitudinal as well as transverse size of the region in which parametric transformation takes place is of fundamental importance. It is shown that maximal suppression of noise from difference photocurrent requires a high degree of entanglement of two-photon light at the outlet of the parametric amplifier, which is defined by Federov et al. [Phys. Rev. A 77, 032336 (2008)] as the ratio of the intensity distribution width to the correlation function width. The detection volume should be chosen taking into account both these quantities. Various modes of single-pass generation of twin beams (noncollinear frequency-degenerate and collinear frequency-nondegenerate synchronism of type I, as well as collinear frequency-degenerate synchronism of type II) are considered in connection with the degree of entanglement.

  3. Study of collective radial breathing-like modes in double-walled carbon nanotubes: combination of continuous two-dimensional membrane theory and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Levshov, Dmitry I.; Avramenko, Marina V.; Than, Xuan-Tinh; Michel, Thierry; Arenal, Raul; Paillet, Matthieu; Rybkovskiy, Dmitry V.; Osadchy, Alexander V.; Rochal, Sergei B.; Yuzyuk, Yuri I.; Sauvajol, Jean-Louis

    2016-01-01

    Radial breathing modes (RBMs) are widely used for the atomic structure characterization and index assignment of single-walled carbon nanotubes (SWNTs) from resonant Raman spectroscopy. However, for double-walled carbon nanotubes (DWNTs), the use of conventional ωRBM(d) formulas is complicated due to the van der Waals interaction between the layers, which strongly affects the frequencies of radial modes and leads to new collective vibrations. This paper presents an alternative way to theoretically study the collective radial breathing-like modes (RBLMs) of DWNTs and to account for interlayer interaction, namely the continuous two-dimensional membrane theory. We obtain an analytical ωRBLM(do,di) relation, being the equivalent of the conventional ωRBM(d) expressions, established for SWNTs. We compare our theoretical predictions with Raman data, measured on individual index-identified suspended DWNTs, and find a good agreement between experiment and theory. Moreover, we show that the interlayer coupling in individual DWNTs strongly depends on the interlayer distance, which is manifested in the frequency shifts of the RBLMs with respect to the RBMs of the individual inner and outer tubes. In terms of characterization, this means that the combination of Raman spectroscopy data and predictions of continuous membrane theory may give additional criteria for the index identification of DWNTs, namely the interlayer distance.

  4. Effect of fed-batch vs. continuous mode of operation on microbial fuel cell performance treating biorefinery wastewater

    DOE PAGESBeta

    Pannell, Tyler C.; Goud, R. Kannaiah; Schell, Daniel J.; Borole, Abhijeet P.

    2016-05-01

    Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8±0.06 A/m2 and an ACE of 39%±4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m2 and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stable achieving anmore » ACE of 30% ± 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7±0.1 A/m2 and an ACE of 57% ± 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of Firmicutes and Proteobacteria and lower abundance of Bacteriodetes and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.« less

  5. Wet spinning of continuous polymer-free carbon-nanotube fibers with high electrical conductivity and strength

    NASA Astrophysics Data System (ADS)

    Mukai, Ken; Asaka, Kinji; Wu, Xueli; Morimoto, Takahiro; Okazaki, Toshiya; Saito, Takeshi; Yumura, Motoo

    2016-05-01

    We report on the fabrication of polymer-free carbon nanotube (CNT) fibers by a novel wet spinning method combined with a very easy and straightforward fabrication process. These fibers exhibited high electrical conductivity (14,284 ± 169 S·cm‑1) and tensile strength (887 ± 37 MPa). Such high performance was made possible by the preparation of free-standing CNT fibers from a surfactant solution containing uniformly dispersed CNTs, despite the use of an organic coagulating solvent and subsequent stretching to align the CNTs in the fiber.

  6. Modes of high-latitude conductance variability derived from DMSP F6-F8 and F16-F18 energetic electron precipitation observations: Empirical Orthogonal Function (EOF) analysis

    NASA Astrophysics Data System (ADS)

    McGranaghan, Ryan Michael; Knipp, Delores J.; Matsuo, Tomoko; Godinez, Humberto; Redmon, Robert; Morley, Steve; Solomon, Stanley

    2015-04-01

    Energy redistribution in the magnetosphere-ionosphere-thermosphere (MIT) system is largely controlled by a complex system of field-aligned, Hall, and Pedersen currents, and the electrodynamics underlying their distributions. According to Ohm’s law, the electrodynamics relationships rely on knowledge of the ionospheric conductivity. We present the results of an empirical orthogonal function (EOF) analysis of the horizontal (Pedersen and Hall) ionospheric conductances, using multiple years of Defense Meteorological Satellite (DMSP) data. Our results represent the dominant modes of variability of the Pedersen and Hall conductivities.We show that the mean patterns together with the first four EOFs represent ~70 and 68% of the total Pedersen and Hall conductance variabilities, respectively. We find each of the first four EOFs for both conductances represent clear and distinguishable geophysical phenomena. The first EOF represents variation in the quasi-permanent aurora associated with diffuse electron precipitation. The second and third EOFs, in varying order for each horizontal conductance, show features of an expanded auroral zone due to geomagnetic activity and distinct MLT `hot spots' associated with northward IMF conditions. The fourth EOF shows a signature of the substorm current wedge in the post-dusk to pre-midnight sector.Finally, we compare the results of EOFs estimated from DMSP satellite data with those obtained using electron precipitation data from the Fast Auroral SnapshoT Explorer (FAST) satellite.

  7. A monitor for continuous measurement of temperature, pH, and conductance of wet precipitation: Preliminary results from the Adirondack Mountains, New York

    USGS Publications Warehouse

    Johnsson, P.A.; Reddy, M.M.

    1990-01-01

    This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.

  8. Enhanced cofermentation of glucose and xylose by recombinant Saccharomyces yeast strains in batch and continuous operating modes

    SciTech Connect

    Toon, S.T.; Riley, C.J.; Ho, N.W.Y.; Chen, ZhengDao

    1997-12-31

    Agricultural residues, such as grain by-products, are rich in the hydrolyzable carbohydrate polymers hemicellulose and cellulose; hence, they represent a readily available source of the fermentable sugars xylose and glucose. The biomass-to-ethanol technology is now a step closer to commercialization because a stable recombinant yeast strain has been developed that can efficiently ferment glucose and xylose simultaneously (coferment) to ethanol. This strain, LNH-ST, is a derivative of Saccharomyces yeast strain 1400 that carries the xylose-catabolism encoding genes of Pichia stipitis in its chromosome. Continuous pure sugar cofermentation studies with this organism resulted in promising steady-state ethanol yields (70.4% of theoretical based on available sugars) at a residence time of 48 h. 17 refs., 4 figs., 3 tabs.

  9. Tunable diode laser-pumped Tm,Ho:YLF laser operated in continuous-wave and Q-switched modes

    NASA Technical Reports Server (NTRS)

    Mcguckin, B. T.; Hemmati, H.; Menzies, R. T.

    1992-01-01

    Tunable continuous-wave and pulsed laser output was obtained from a Tm-sensitized Ho:YLiF4 crystal at subambient temperatures when longitudinally pumped with a diode laser array. A conversion efficiency of 42 percent and slope efficiency of approximately 60 percent relative to the absorbed pumped power have been achieved at a crystal temperature of 275 K. The emission spectrum was etalon tunable over a range of 16/cm centered at 2067 nm with fine tuning capability of the transition frequency with crystal temperature at measured rate of -0.03/cm/K. Output energies of 0.22 mJ per pulse and 22 ns pulse duration were recorded at Q-switch frequencies that correspond to an effective upper laser level lifetime of 6 ms, and a pulse energy extraction efficiency of 64 percent.

  10. Continuous-wave optical stimulation of the rat prostate nerves using an all-single-mode 1455 nm diode laser and fiber system

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2011-03-01

    Optical nerve stimulation (ONS) has recently been reported as a potential alternative to electrical nerve stimulation. Continuous-wave (CW) laser stimulation of the prostate cavernous nerves (CN) in a rat model, in vivo, has also been demonstrated in our previous studies. The objective of this study is to present a new all-single-mode-fiber configuration for ONS with the laser operating in CW mode for potential diagnostic applications. An infrared pigtailed single-mode diode laser (λ = 1455 nm) was used in this study for noncontact ONS. This new all-fiber approach introduces several advantages including: (1) a less expensive and more compact ONS system, (2) elimination of alignment of optical components, and (3) an improved spatial beam profile. Successful optical stimulation of the rat CN using this new design was observed after the CN reached a threshold temperature of ~ 41 °C with response times as short as 3 s. Upon further study, this configuration may be useful for identification and preservation of the cavernous nerves during prostate cancer surgery.

  11. Liquid-phase epitaxy grown PbSnTe distributed feedback laser diodes with broad continuous single-mode tuning range

    NASA Technical Reports Server (NTRS)

    Hsieh, H.-H.; Fonstad, C. G.

    1980-01-01

    Distributed feedback (DFB) pulsed laser operation has been demonstrated in stripe geometry Pb(1-x)Sn(x)Te double-heterostructures grown by liquid-phase epitaxy. The grating structure of 0.79 micron periodicity operates in first order near 12.8 microns and was fabricated prior to the liquid-phase epitaxial growth using holographic exposure techniques. These DFB lasers had moderate thresholds, 3.6 kA/sq cm, and the output power versus current curves exhibited a sharp turn-on free of kinks. Clean, single-mode emission spectra, continuously tunable over a range in excess of 20 per cm, centered about 780 per cm (12.8 microns), and at an average rate of 1.2 per cm-K from 9 to 26 K, were observed. While weaker modes could at times be seen in the spectrum, substantially single-mode operation was obtained over the entire operating range and to over 10 times threshold.

  12. In-situ measurement of thermal conductivity using the continuous-heating line-source method and WHOI outrigged probe. Technical report

    SciTech Connect

    Jemsek, J.; Von Herzen, R.; Andrew, P.

    1985-08-01

    The outrigged thermal probes of a 'pogo' marine geothermal probe have been adapted to measure thermal conductivity in-situ by the continuous-heating line source technique. The instrumental uncertainty in applying the analytical theory to a single-probe and double-probe configuration is found to be 3 and 6 percent, respectively. The in-situ outrigged single probe (.32 cm dia.) is essentially a scaled-up version of the needle probe (.08 cm dia.). The main advantage of the outrigged probe over a larger radius probe (e.g., violin-bow probe) is that for short-time temperatures (<2 min.), simple approximations to the exact solution for a perfectly conducting cylindrical probe are achieved. The continuous-heating compares favorably with the pulse-heating technique, the latter being more energy efficient. The continuous-heating method applied to the thin outrigged probe allows for accurate equilibrium in-situ temperature and thermal conductivity estimates in less than 15 minutes of recording time. The technique has been applied to several hundred marine heat flow stations. Comparison of in-situ measurements to needle probe measurements made on nearby piston cores indicate agreement to within 5%.

  13. Engineering non-linear resonator mode interactions in circuit QED by continuous driving: Manipulation of a photonic quantum memory

    NASA Astrophysics Data System (ADS)

    Reagor, Matthew; Pfaff, Wolfgang; Heeres, Reinier; Ofek, Nissim; Chou, Kevin; Blumoff, Jacob; Leghtas, Zaki; Touzard, Steven; Sliwa, Katrina; Holland, Eric; Albert, Victor V.; Frunzio, Luigi; Devoret, Michel H.; Jiang, Liang; Schoelkopf, Robert J.

    2015-03-01

    Recent advances in circuit QED have shown great potential for using microwave resonators as quantum memories. In particular, it is possible to encode the state of a quantum bit in non-classical photonic states inside a high-Q linear resonator. An outstanding challenge is to perform controlled operations on such a photonic state. We demonstrate experimentally how a continuous drive on a transmon qubit coupled to a high-Q storage resonator can be used to induce non-linear dynamics of the resonator. Tailoring the drive properties allows us to cancel or enhance non-linearities in the system such that we can manipulate the state stored in the cavity. This approach can be used to either counteract undesirable evolution due to the bare Hamiltonian of the system or, ultimately, to perform logical operations on the state encoded in the cavity field. Our method provides a promising pathway towards performing universal control for quantum states stored in high-coherence resonators in the circuit QED platform.

  14. ZnO-PLLA Nanofiber Nanocomposite for Continuous Flow Mode Purification of Water from Cr(VI)

    PubMed Central

    Burks, T.; Akthar, F.; Saleemi, M.; Avila, M.; Kiros, Y.

    2015-01-01

    Nanomaterials of ZnO-PLLA nanofibers have been used for the adsorption of Cr(VI) as a prime step for the purification of water. The fabrication and application of the flexible ZnO-PLLA nanofiber nanocomposite as functional materials in this well-developed architecture have been achieved by growing ZnO nanorod arrays by chemical bath deposition on synthesized electrospun poly-L-lactide nanofibers. The nanocomposite material has been tested for the removal and regeneration of Cr(IV) in aqueous solution under a “continuous flow mode” by studying the effects of pH, contact time, and desorption steps. The adsorption of Cr(VI) species in solution was greatly dependent upon pH. SEM micrographs confirmed the successful fabrication of the ZnO-PLLA nanofiber nanocomposite. The adsorption and desorption of Cr(VI) species were more likely due to the electrostatic interaction between ZnO and Cr(VI) ions as a function of pH. The adsorption and desorption experiments utilizing the ZnO-PLLA nanofiber nanocomposite have appeared to be an effective nanocomposite in the removal and regeneration of Cr(VI) species. PMID:26681961

  15. All-fiber quasi-continuous wave supercontinuum generation in single-mode high-nonlinear fiber pumped by submicrosecond pulse with low peak power.

    PubMed

    Gao, Weiqing; Liao, Meisong; Yan, Xin; Suzuki, Takenobu; Ohishi, Yasutake

    2012-05-01

    We demonstrate quasi-continuous wave supercontinuum generation in a single-mode high-nonlinear fiber (HNLF) in 1.55 μm band, which is pumped by the amplified passively Q-switched submicrosecond pulse. The pump wavelength is in the normal dispersion region of HNLF and near to the zero-dispersion wavelength. The broad SC spectral range from 1200 to 2260 nm is obtained with the low pump peak power of 17.8 W. The 20 dB bandwidth of 922 nm from 1285 to 2207 nm is obtained with the assumption that the peak near 1560 nm is filtered. The spectrum density for the 20 dB bandwidth is from -27.5 to -7.5 dbm/nm. PMID:22614410

  16. High power, widely tunable, mode-hop free, continuous wave external cavity quantum cascade laser for multi-species trace gas detection

    SciTech Connect

    Centeno, R.; Marchenko, D.; Mandon, J.; Cristescu, S. M.; Harren, F. J. M.; Wulterkens, G.

    2014-12-29

    We present a high power, widely tunable, continuous wave external cavity quantum cascade laser designed for infrared vibrational spectroscopy of molecules exhibiting broadband and single line absorption features. The laser source exhibits single mode operation with a tunability up to 303 cm{sup −1} (∼24% of the center wavelength) at 8 μm, with a maximum optical output power of 200 mW. In combination with off-axis integrated output spectroscopy, trace-gas detection of broadband absorption gases such as acetone was performed and a noise equivalent absorption sensitivity of 3.7 × 10{sup −8 }cm{sup −1 }Hz{sup −1/2} was obtained.

  17. Scale effect of anaerobic digestion tests in fed-batch and semi-continuous mode for the technical and economic feasibility of a full scale digester.

    PubMed

    Ruffino, Barbara; Fiore, Silvia; Roati, Chiara; Campo, Giuseppe; Novarino, Daniel; Zanetti, Mariachiara

    2015-04-01

    Methane production capacity in mesophilic conditions of waste from two food industry plants was assessed in a semi-pilot (6L, fed-batch) and pilot (300 L, semi-continuous) scale. This was carried out in order to evaluate the convenience of producing heat and electricity in a full scale anaerobic digester. The pilot test was performed in order to obtain more reliable results for the design of the digester. Methane yield, returned from the pilot scale test, was approximately 80% of that from the smaller scale test. This outcome was in line with those from other studies performed in different scales and modes and indicates the success of the pilot scale test. The net electricity produced from the digester accounted for 30-50% of the food industry plants' consumption. The available thermal energy could cover from 10% to 100% of the plant requirements, depending on the energy demand of the processes performed. PMID:25710569

  18. 1.9 W continuous-wave single transverse mode emission from 1060 nm edge-emitting lasers with vertically extended lasing area

    SciTech Connect

    Miah, M. J. Posilovic, K.; Kalosha, V. P.; Rosales, R.; Bimberg, D.; Kettler, T.; Skoczowsky, D.; Pohl, J.; Weyers, M.

    2014-10-13

    High-brightness edge-emitting semiconductor lasers having a vertically extended waveguide structure emitting in the 1060 nm range are investigated. Ridge waveguide (RW) lasers with 9 μm stripe width and 2.64 mm cavity length yield highest to date single transverse mode output power for RW lasers in the 1060 nm range. The lasers provide 1.9 W single transverse mode optical power under continuous-wave (cw) operation with narrow beam divergences of 9° in lateral and 14° (full width at half maximum) in vertical direction. The beam quality factor M{sup 2} is less than 1.9 up to 1.9 W optical power. A maximum brightness of 72 MWcm{sup −2}sr{sup −1} is obtained. 100 μm wide and 3 mm long unpassivated broad area lasers provide more than 9 W optical power in cw operation.

  19. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part III. Optimization of the chromatographic efficiency.

    PubMed

    Al-Massaedh, Ayat Allah; Pyell, Ute

    2014-01-17

    In a previous article we described the synthesis of amphiphilic monolithic stationary phases by in situ free radical copolymerization of cyclodextrin-solubilized N-adamantyl acrylamide, piperazinediacrylamide, methacrylamide and vinylsulfonic acid in aqueous medium in pre-treated fused silica capillaries of 100μ.m I.D. In this work, a series of N-adamantyl-group containing acrylamide-based continuous beds is synthesized under variation of different synthesis parameters. The studied synthesis parameters are (i) concentration of the lyotropic salt ammonium sulfate, (ii) concentration of the initiator ammonium persulfate, and (iii) concentration of the negatively charged monomer vinylsulfonic acid in the polymerization mixture. The influence of the synthesis parameters on the chromatographic efficiency is studied under isocratic conditions for a homologues series of alkylphenones in the reversed-phase mode at constant composition of the mobile phase via capillary electrochromatography with varied electric field strength. With varied concentration of the lyotropic salt ammonium sulfate or varied concentration of the initiator ammonium persulfate in the polymerization mixture, a strong impact on the chromatographic efficiency is observed, while there is only a minor influence when varying the molar fraction of the charged monomer VSA. The absence of a significant influence of extra-column band broadening effects on the determined efficiency is confirmed. There is a good repeatability (with respect to capillary-to-capillary variation and run-to-run variation) reached for the theoretical plate heights obtained for DMF and selected alkylphenones in the reversed-phase mode. PMID:24296296

  20. Continuous Measurements of Electrical Conductivity and Viscosity of Lherzorite Analogue Samples during Slow Increases and Decreases in Temperature: Melting and Pre-melting Effects

    NASA Astrophysics Data System (ADS)

    Sueyoshi, K.; Hiraga, T.

    2014-12-01

    It has been considered that transport properties of the mantle (ex. electrical conductivity, viscosity, seismic attenuation) changes dramatically during ascend of the mantle especially at around the mantle solidus. To understand the mechanism of such changes, we measured the electrical conductivity and viscosity of the lherzorite analogues during slow increases and decreases in temperature reproducing the mantle crossing its solidus. Two types of samples, one was forsterite plus 20% diopside and the other was 50% forsterite, 40% enstatite and 10% diopside with addition of 0.5% spinel, were synthesized from Mg(OH)2, SiO2, CaCO3 and MgAl2O4 (spinel) powders with particle size of <50 nm. Samples were expected to exhibit different manners in initiation of partial melt and amount of melt during the temperature change. We continuously measured electrical conductivity of these samples at every temperature during gradual temperature change, which crosses the sample solidus (~1380℃ and 1230℃ for forsterite + diopside sample and spinel-added samples, respectively). Sample viscosity were also measured under constant loads of 0.5~50 MPa. The electrical conductivity and viscosity at well below (>150℃) the sample solidus exhibited linear distributions in their Arrhenius plots indicating that a single mechanism controls for each transport property within the experimental temperature ranges. Such linear relationship especially in the electrical conductivity was no longer observed at higher temperature regime exhibiting its exponential increase until the temperature reached the sample solidus. Such dramatic change with changing temperature has not been detected for the sample viscosity. Monotonic increase of electrical conductivity in accordance with increasing melt fraction was observed above the sample solidus.

  1. Electric field variations measured continuously in free air over a conductive thin zone in the tilted Lias-epsilon black shales near Osnabrück, Northwest Germany

    NASA Astrophysics Data System (ADS)

    Gurk, M.; Bosch, F. P.; Tougiannidis, N.

    2013-04-01

    Common studies on the static electric field distribution over a conductivity anomaly use the self-potential method. However, this method is time consuming and requires nonpolarizable electrodes to be placed in the ground. Moreover, the information gained by this method is restricted to the horizontal variations of the electric field. To overcome the limitation in the self-potential technique, we conducted a field experiment using a non conventional technique to assess the static electric field over a conductivity anomaly. We use two metallic potential probes arranged on an insulated boom with a separation of 126 cm. When placed into the electric field of the free air, a surface charge will be induced on each probe trying to equalize with the potential of the surrounding atmosphere. The use of a plasma source at both probes facilitated continuous and quicker measurement of the electric field in the air. The present study shows first experimental measurements with a modified potential probe technique (MPP) along a 600-meter-long transect to demonstrate the general feasibility of this method for studying the static electric field distribution over shallow conductivity anomalies. Field measurements were carried out on a test site on top of the Bramsche Massif near Osnabrück (Northwest Germany) to benefit from a variety of available near surface data over an almost vertical conductivity anomaly. High resolution self-potential data served in a numerical analysis to estimate the expected individual components of the electric field vector. During the experiment we found more anomalies in the vertical and horizontal components of the electric field than self-potential anomalies. These contrasting findings are successfully cross-validated with conventional near surface geophysical methods. Among these methods, we used self-potential, radiomagnetotelluric, electric resistivity tomography and induced polarization data to derive 2D conductivity models of the subsurface in

  2. Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source.

    PubMed

    Wells, R P; Ghiorso, W; Staples, J; Huang, T M; Sannibale, F; Kramasz, T D

    2016-02-01

    A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described. PMID:26931840

  3. Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source

    NASA Astrophysics Data System (ADS)

    Wells, R. P.; Ghiorso, W.; Staples, J.; Huang, T. M.; Sannibale, F.; Kramasz, T. D.

    2016-02-01

    A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described.

  4. Continuous tidal streamflow, water level, and specific conductance data for Union Creek and the Little Back, Middle, and Front Rivers, Savannah River Estuary, November 2008 to March 2009

    USGS Publications Warehouse

    Lanier, Timothy H.; Conrads, Paul A.

    2010-01-01

    In the Water Resource Development Act of 1999, the U.S. Congress authorized the deepening of the Savannah Harbor. Additional studies were then identified by the Georgia Ports Authority and other local and regional stakeholders to determine and fully describe the potential environmental effects of deepening the channel. One need that was identified was the validation of a three-dimensional hydrodynamic model developed to evaluate mitigation scenarios for a potential harbor deepening and the effects on the Savannah River estuary. The streamflow in the estuary is very complex due to reversing tidal flows, interconnections of streams and tidal creeks, and the daily flooding and draining of the marshes. The model was calibrated using very limited streamflow data and no continuous streamflow measurements. To better characterize the streamflow dynamics and mass transport of the estuary, two index-velocity sites were instrumented with continuous acoustic velocity, water level, and specific conductance sensors on the Little Back and Middle Rivers for the 5-month period of November 2008 through March 2009. During the same period, a third acoustic velocity meter was installed on the Front River just downstream from U.S. Geological Survey streamgaging station 02198920 (Savannah River at GA 25, at Port Wentworth, Georgia) where water level and specific conductance data were being collected. A fourth index-velocity site was instrumented with continuous acoustic velocity, water level, and specific conductance sensors on Union Creek for a 2-month period starting in November 2008. In addition to monitoring the tidal cycles, streamflow measurements were made at the four index-velocity sites to develop ratings to compute continuous discharge for each site. The maximum flood (incoming) and ebb (outgoing) tides measured on Little Back River were –4,570 and 7,990 cubic feet per second, respectively. On Middle River, the maximum flood and ebb tides measured were –9,630 and 13

  5. Heat conduction in conducting polyaniline nanofibers

    NASA Astrophysics Data System (ADS)

    Nath, Chandrani; Kumar, A.; Syu, K.-Z.; Kuo, Y.-K.

    2013-09-01

    Thermal conductivity and specific heat of conducting polyaniline nanofibers are measured to identify the nature of heat carrying modes combined with their inhomogeneous structure. The low temperature thermal conductivity results reveal crystalline nature while the high temperature data confirm the amorphous nature of the material suggesting heterogeneous model for conducting polyaniline. Extended acoustic phonons dominate the low temperature (<100 K) heat conduction, while localized optical phonons hopping, assisted by the extended acoustic modes, account for the high temperature (>100 K) heat conduction.

  6. Microstructure correlation in high-strength steels with continuous stiffness mode nanoindentation results. High-resolution vs. low-resolution nanoindentation

    NASA Astrophysics Data System (ADS)

    Hackney, Stephen A.; Bradley, John R.; Wood, Thomas D.; Miskioglu, Ibrahim

    2013-04-01

    This study utilizes instrumented nanoindentation to compare the mechanical response of a transformation-induced plasticity (TRIP) steel to that of a quench and partition steel (QP). The nanoindenter was operated using continuous stiffness mode, and the microstructure under the indent revealed by chemical etching was examined. Examination of the microstructure in the indents by scanning electron microscopy allows a direct correlation with nanoindentation properties. It is found that the hardness measured at an indentation depth of 1.1 μm is, on average, significantly greater in the QP steel than in the TRIP steel. The continuous hardness measurement also allows the microstructure observed at the center of the indent to be correlated with the hardness values when indentation depths are <0.1 μm. This high-resolution hardness measurement allows for a direct comparison of mechanical response for the individual retained austenite phase particles in the TRIP steel with the strengthening microconstituent in the QP steel. With this methodology, the surprising result is that the TRIP retained austenite particles have a higher hardness than the QP hardening microconstituent. It is proposed that the resolution of the apparent disagreement between the hardness measurements obtained at 1.1 μm depth (QP has the higher hardness) and the 0.1-μm depth hardness measurements of the microconstituents containing retained austenite (TRIP has the higher hardness) lies in the volume fraction of the microconstituent as the QP has a two- to threefold higher volume fraction of hardening phase as compared to TRIP.

  7. Continuous mode of carbon dioxide sequestration by C. sorokiniana and subsequent use of its biomass for hydrogen production by E. cloacae IIT-BT 08.

    PubMed

    Kumar, Kanhaiya; Roy, Shantonu; Das, Debabrata

    2013-10-01

    The present study investigated to find out the suitability of the CO2 sequestered algal biomass of Chlorella sorokiniana as substrate for the hydrogen production by Enterobacter cloacae IIT-BT 08. The maximum biomass productivity in continuous mode of operation in autotrophic condition was enhanced from 0.05 g L(-1) h(-1) in air to 0.11 g L(-1) h(-1) in 5% air-CO2 (v/v) gas mixture at an optimum dilution rate of 0.05 h(-1). Decrease in steady state biomass and productivity was less sensitive at higher dilution and found fitting with the model proposed by Eppley and Dyer (1965). Pretreated algal biomass of 10 g L(-1) with 2% (v/v) HCl-heat was found most suitable for hydrogen production yielding 9±2 mol H2 (kg COD reduced)(-1) and was found fitting with modified Gompertz equation. Further, hydrogen energy recovery in dark fermentation was significantly enhanced compared to earlier report of hydrogen production by biophotolysis of algae. PMID:23453984

  8. Safety Management of a Clinical Process Using Failure Mode and Effect Analysis: Continuous Renal Replacement Therapies in Intensive Care Unit Patients.

    PubMed

    Sanchez-Izquierdo-Riera, Jose Angel; Molano-Alvarez, Esteban; Saez-de la Fuente, Ignacio; Maynar-Moliner, Javier; Marín-Mateos, Helena; Chacón-Alves, Silvia

    2016-01-01

    The failure mode and effect analysis (FMEA) may improve the safety of the continuous renal replacement therapies (CRRT) in the intensive care unit. We use this tool in three phases: 1) Retrospective observational study. 2) A process FMEA, with implementation of the improvement measures identified. 3) Cohort study after FMEA. We included 54 patients in the pre-FMEA group and 72 patients in the post-FMEA group. Comparing the risks frequencies per patient in both groups, we got less cases of under 24 hours of filter survival time in the post-FMEA group (31 patients 57.4% vs. 21 patients 29.6%; p < 0.05); less patients suffered circuit coagulation with inability to return the blood to the patient (25 patients [46.3%] vs. 16 patients [22.2%]; p < 0.05); 54 patients (100%) versus 5 (6.94%) did not get phosphorus levels monitoring (p < 0.05); in 14 patients (25.9%) versus 0 (0%), the CRRT prescription did not appear on medical orders. As a measure of improvement, we adopt a dynamic dosage management. After the process FMEA, there were several improvements in the management of intensive care unit patients receiving CRRT, and we consider it a useful tool for improving the safety of critically ill patients. PMID:26418206

  9. Assessing acute toxicity of effluent from a textile industry and nearby river waters using sulfur-oxidizing bacteria in continuous mode.

    PubMed

    Gurung, Anup; Hassan, Sedky H A; Oh, Sang-Eun

    2011-10-01

    Bioassays are becoming an important tool for assessing the toxicity of complex mixtures of substances in aquatic environments in which Daphnia magna is routinely used as a test organism. Bioassays outweigh physicochemical analyses and are valuable in the decision-making process pertaining to the final discharge of effluents from wastewater treatment plants as they measure the total effect of the discharge which is ecologically relevant. In this study, the aquatic toxicity of a textile plant effluent and river water downstream from the plant were evaluated with sulfur-oxidizing bacterial biosensors in continuous mode. Collected samples were analysed for different physicochemical parameters and 1,4-dioxane was detected in the effluent. The effluent contained a relatively high chemical oxygen demand of 60 mg L(-1), which exceeded the limit set by the Korean government for industrial effluent discharges. Results showed that both the effluent and river waters were toxic to sulfur-oxidizing bacteria. These results show the importance of incorporating bioassays to detect toxicity in wastewater effluents for the sustainable management of water resources. PMID:22329151

  10. Reduction of Common-Mode Conducted Noise Emissions in PWM Inverter-fed AC Motor Drive Systems using Optimized Passive EMI Filter

    NASA Astrophysics Data System (ADS)

    Jettanasen, C.; Ngaopitakkul, A.

    2010-10-01

    Conducted electromagnetic interference (EMI) generated by PWM inverter-fed induction motor drive systems, which are currently widely used in many industrial and/or avionic applications, causes severe parasitic current problems, especially at high frequencies (HF). These restrict power electronic drive's evolution. In order to reduce or minimize these EMI problems, several techniques can be applied. In this paper, insertion of an optimized passive EMI filter is proposed. This filter is optimized by taking into account real impedances of each part of a considered AC motor drive system contrarily to commercial EMI filters designed by considering internal impedance of disturbance source and load, equal to 50Ω. Employing the latter EMI filter would make EMI minimization less effective. The proposed EMI filter optimization is mainly dedicated to minimize common mode (CM) currents due to its most dominant effects in this kind of system. The efficiency of the proposed optimization method using two-port network approach is deduced by comparing the minimized CM current spectra to an applied normative level (ex. DO-160D in aeronautics).

  11. Groundwater discharge to wetlands driven by storm and flood events: Quantification using continuous Radon-222 and electrical conductivity measurements and dynamic mass-balance modelling

    NASA Astrophysics Data System (ADS)

    Gilfedder, B. S.; Frei, S.; Hofmann, H.; Cartwright, I.

    2015-09-01

    The dynamic response of groundwater discharge to external influences such as rainfall is an often neglected part of water and solute balances in wetlands. Here we develop a new field platform for long-term continuous 222Rn and electrical conductivity (EC) measurements at Sale Wetland, Australia to study the response of groundwater discharge to storm and flood events. The field measurements, combined with dynamic mass-balance modelling, demonstrate that the groundwater flux can increase from 3 to ∼20 mm d-1 following storms and up to 5 mm d-1 on the receding limb of floods. The groundwater pulses are likely produced by activation of local groundwater flow paths by water ponding on the surrounding flood plains. While 222Rn is a sensitive tracer for quantifying transient groundwater discharge, the mass-balance used to estimate fluxes is sensitive to parameterisation of gas exchange (k) with the atmosphere. Comparison of six equations for calculating k showed that, based on parameterisation of k alone, the groundwater flux estimate could vary by 58%. This work shows that neglecting transient processes will lead to errors in water and solute flux estimates based on infrequent point measurements. This could be particularly important for surface waters connected to contaminated or saline groundwater systems.

  12. Oscillations in the reduction of permanganate by hydrogen peroxide or by ninhydrin in a batch reactor and mixed-mode oscillations in a continuous-flow stirred tank reactor

    NASA Astrophysics Data System (ADS)

    Tóthová, Mária; Nagy, Arpád; Treindl, Ľudovít.

    1999-01-01

    The periodical reduction of permanganate by hydrogen peroxide or by ninhydrin with transient oscillations in a closed system has been observed and discussed in relation to the first two permanganate oscillators described earlier. The mixed-mode oscillations of the permanganate-H 2O 2 oscillating system in a continuous-flow stirred tank reactor have been described.

  13. 20 CFR 220.185 - The Board may conduct a review to find out whether the annuitant continues to be disabled.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... whether the annuitant continues to be disabled. 220.185 Section 220.185 Employees' Benefits RAILROAD... review to find out whether the annuitant continues to be disabled. After the Board finds that the annuitant is disabled, the Board must evaluate the annuitant's impairment(s) from time to time to...

  14. 20 CFR 220.185 - The Board may conduct a review to find out whether the annuitant continues to be disabled.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... whether the annuitant continues to be disabled. 220.185 Section 220.185 Employees' Benefits RAILROAD... review to find out whether the annuitant continues to be disabled. After the Board finds that the annuitant is disabled, the Board must evaluate the annuitant's impairment(s) from time to time to...

  15. 20 CFR 220.185 - The Board may conduct a review to find out whether the annuitant continues to be disabled.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... whether the annuitant continues to be disabled. 220.185 Section 220.185 Employees' Benefits RAILROAD... review to find out whether the annuitant continues to be disabled. After the Board finds that the annuitant is disabled, the Board must evaluate the annuitant's impairment(s) from time to time to...

  16. 20 CFR 220.185 - The Board may conduct a review to find out whether the annuitant continues to be disabled.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... whether the annuitant continues to be disabled. 220.185 Section 220.185 Employees' Benefits RAILROAD... review to find out whether the annuitant continues to be disabled. After the Board finds that the annuitant is disabled, the Board must evaluate the annuitant's impairment(s) from time to time to...

  17. 20 CFR 220.185 - The Board may conduct a review to find out whether the annuitant continues to be disabled.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... whether the annuitant continues to be disabled. 220.185 Section 220.185 Employees' Benefits RAILROAD... review to find out whether the annuitant continues to be disabled. After the Board finds that the annuitant is disabled, the Board must evaluate the annuitant's impairment(s) from time to time to...

  18. A Review and Empirical Comparison of Three Treatments for Adolescent Males with Conduct and Personality Disorder: Mode Deactivation Therapy, Cognitive Behavior Therapy and Social Skills Training

    ERIC Educational Resources Information Center

    Apsche, Jack A.; Bass, Christopher K.; Siv, Alexander M.

    2005-01-01

    This treatment research study extended the results of Apsche, Bass, Jennings, Murphy, Hunter, and Siv (2005), from behavioral data to standard measures of psychological distress. In Apsche, et. al. (2005) results suggest that Mode Deactivation Therapy (MDT) was more effective than Cognitive Behavior Therapy (CBT) and Social Skills Therapy (SST) in…

  19. Optimization of passively mode-locked quasi-continuously diode-pumped Nd:GdVO4 laser in bounce geometry

    NASA Astrophysics Data System (ADS)

    Frank, Milan; Jelínek, Michal; Kubeček, Václav

    2015-01-01

    In this paper the operation of pulsed diode-pumped Nd:GdVO4 laser oscillator in bounce geometry passively modelocked using semiconductor saturable absorber mirror (SAM), generating microjoule level picosecond pulses at wavelength of 1063 nm, is reported. Optimization of the output coupling for generation either Q-switched mode locked pulse trains or cavity dumped single pulses with maximum energy was performed, which resulted in extraction of single pulses as short as 10 ps and energy of 20 uJ. In comparison with the previous results obtained with this Nd:GdVO4 oscillator and saturable absorber in transmission mode, the achieved pulse duration is five times shorter. Using different absorbers and parameters of single pulse extraction enables generation of the pulses with duration up to 100 ps with the energy in the range from 10 to 20 μJ.

  20. CONTINUOUS-MODE PHOTOCATALYTIC DEGRADATION OF CHLORINATED PHENOLS AND PESTICIDES IN WATER USING A BENCH-SCALE TIO2 ROTATING DISK REACTOR

    EPA Science Inventory

    Photocatalytic degradation of phenol, chlorinated phenols, and lindane was evaluated in a continuous flow TiOz rotating disk photocatalytic reactor (RDPR). The RDPR operated at a hydraulic residence time of 0.25 day and at a disk angular velocity of 12 rpm. At low molar feed conc...

  1. Batch vs continuous-feeding operational mode for the removal of pesticides from agricultural run-off by microalgae systems: A laboratory scale study.

    PubMed

    Matamoros, Víctor; Rodríguez, Yolanda

    2016-05-15

    Microalgae-based water treatment technologies have been used in recent years to treat different water effluents, but their effectiveness for removing pesticides from agricultural run-off has not yet been addressed. This paper assesses the effect of microalgae in pesticide removal, as well as the influence of different operation strategies (continuous vs batch feeding). The following pesticides were studied: mecoprop, atrazine, simazine, diazinone, alachlor, chlorfenvinphos, lindane, malathion, pentachlorobenzene, chlorpyrifos, endosulfan and clofibric acid (tracer). 2L batch reactors and 5L continuous reactors were spiked to 10 μg L(-1) of each pesticide. Additionally, three different hydraulic retention times (HRTs) were assessed (2, 4 and 8 days) in the continuous feeding reactors. The batch-feeding experiments demonstrated that the presence of microalgae increased the efficiency of lindane, alachlor and chlorpyrifos by 50%. The continuous feeding reactors had higher removal efficiencies than the batch reactors for pentachlorobenzene, chlorpyrifos and lindane. Whilst longer HRTs increased the technology's effectiveness, a low HRT of 2 days was capable of removing malathion, pentachlorobenzene, chlorpyrifos, and endosulfan by up to 70%. This study suggests that microalgae-based treatment technologies can be an effective alternative for removing pesticides from agricultural run-off. PMID:26882523

  2. Survival of Listeria monocytogenes, E.coli 0157:H7 and Salmonella spp. on catfish fillets exposed to microwave heating in a continuous mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave (MW) heating using continuous power output with feedback control and a modified ingredient formulation, may provide better and consistent cooking of foods. Currently, household units with build-in inverter power supply units are available. These new generation microwave ovens provide con...

  3. Changes in morphology and local conductance of GeTe-Sb2Te3 superlattice films on silicon observed by scanning probe microscopy in a lithography mode

    NASA Astrophysics Data System (ADS)

    Bolotov, Leonid; Tada, Tetsuya; Saito, Yuta; Tominaga, Junji

    2016-04-01

    Changes in the morphology and conductance state of [(GeTe)2(Sb2Te3)] superlattice (SL) films on Si(100) caused by external voltage were investigated by multimode scanning probe microscopy (MSPM) and scanning probe lithography (SPL) at room temperature in vacuum. After SPL patterning at a write voltage exceeding a threshold value, grain-dependent changes in transverse film conductance appeared in the MSPM current maps at a low voltage. Specific details of the conductance state switching were dependent on the film growth process. In uniform films grown in a two-step process, a threshold voltage of 1.6 V and a minimum switching power of ˜15 pW were obtained for conductance switching activated by high-energy electrons injected from the probe. Above 3.0 V, thermally driven regrowth of the SL films was observed. The results demonstrate a simple and appropriate method of optimizing topological SL films as recording media without device fabrication.

  4. Improved continuity of reduced graphene oxide on polyester fabric by use of polypyrrole to achieve a highly electro-conductive and flexible substrate

    NASA Astrophysics Data System (ADS)

    Berendjchi, Amirhosein; Khajavi, Ramin; Yousefi, Ali Akbar; Yazdanshenas, Mohammad Esmail

    2016-02-01

    A flexible and highly conductive fabric can be applied for wearable electronics and as a pliable counter electrode for photovoltaics. Methods such as surface coating of fabrics with conductive polymers and materials have been developed, but the roughness of fabric is a challenge because it creates discontinuity in the coated layer. The present study first coated polyethylene terephthalate (PET) fabric with reduced graphene oxide sheets; RGO and then filled the gaps with polypyrrole (PPy). The samples were first dipped in graphene oxide (GO) and then reduced to RGO. They were next coated with PPy by in situ polymerization. The results showed that the presence of oxidative agent during synthesis of PPy oxidized the RGO to some extent on the previously RGO-coated samples. PPy was more uniform on samples pre-coated with RGO in comparison those coated with raw PET. The RGO-PPy coated samples exhibited 53% and 263% lower surface resistivity values than samples coated only with PPy and RGO, respectively. There was no significant difference between the tenacity of samples but the bending rigidity of samples increased. The RGO-PPy coated fabric displayed properties, such as excellent UV blocking (UPF = 73), antibacterial activity, improved electrochemical behavior and thermal stability which make it a multifunctional fabric.

  5. The Tamiflu saga continues: will our conduct change after the publication of the latest systematic review on benefits and harms of oseltamivir?

    PubMed

    Bachelet, Vivienne C

    2014-01-01

    In 2013, we wrote about the harm, waste and deception stemming from conducts adopted by the pharmaceutical industry, by concealing raw data and Clinical Study Reports (CSRs) from the regulator’s view when requesting the marketing patent. We described the case of Tamiflu (Roche), a drug that has been widely used in our population and profusely prescribed by physicians. Health authorities, entailing a great cost for the countries in the region, have also purchased it. In this editorial, we will show how the idea of using antivirals for prophylaxis and treatment of influenza took hold, starting from the first enthusiastic recommendations up to the systematic review published last month in the BMJ. PMID:25383799

  6. Comment on 'Continuum modes in rotating plasmas: General equations and continuous spectra for large aspect ratio tokamaks'[Phys. Plasmas 18, 092103 (2011)

    SciTech Connect

    Goedbloed, J. P.

    2012-06-15

    It is shown that some of the main results of the recent paper by Lakhin and Ilgisonis [Phys. Plasmas 18, 092103 (2011)], viz. the derivation of the equations for the continuous spectra of poloidally and toroidally rotating plasmas and their special solution for large aspect ratio tokamaks with large parallel flows were obtained before by Goedbloed, Belieen, van der Holst, and Keppens [Phys. Plasmas 11, 28 (2004)]. A further rearrangement of the system of equations for the coupled Alfven and slow continuous spectra clearly exhibits: (a) coupling through a single tangential derivative, which is a generalization of the geodesic curvature; (b) the 'transonic' transitions of the equilibrium, which need to be carefully examined in order to avoid entering hyperbolic flow regimes where the stability formalism breaks down. A critical discussion is devoted to the implications of this failure, which is generally missed in the tokamak literature, possibly as a result of the wide-spread use of the sonic Mach number of gas dynamics, which is an irrelevant and misleading parameter in 'transonic' magnetohydrodynamics. Once this obstacle in understanding is removed, further application of the theory of trans-slow Alfven continuum instabilities to both tokamaks, with possible implications for the L-H transition, and astrophysical objects like 'fat' accretion disks, with a possible new route to magnetohydrodynamic turbulence, becomes feasible.

  7. Capacitively coupled contactless conductivity detection as an alternative detection mode in CE for the analysis of kanamycin sulphate and its related substances.

    PubMed

    El-Attug, Mohamed N; Adams, Erwin; Hoogmartens, Jos; Van Schepdael, Ann

    2011-09-01

    A method was developed to determine simultaneously kanamycin, its related substances and sulphate in kanamycin sulphate using capacitively coupled contactless conductivity detection. Kanamycin is an aminoglycoside antibiotic that lacks a strong UV-absorbing chromophore. Due to its physicochemical properties, CE in combination with capacitively coupled contactless conductivity detection was chosen. The separation method uses a BGE composed of 40 mM 2-(N-morpholino)ethanesulphonic acid monohydrate and 40 mM L-histidine, pH 6.35. A 0.6 mM N-cetyltrimethyl ammonium bromide (CTAB) solution was added as electroosmotic flow modifier in a concentration below the critical micellar concentration (CMC). Ammonium acetate 50 mg/L was used as internal standard. In total, 30 kV was applied in reverse polarity on a fused-silica capillary (65/41 cm; 75 μm id). The optimized separation was obtained in less than 6 min with good linearity (R(2)=0.9999) for kanamycin. It shows a good precision expressed as RSD on the relative peak areas equal to 0.3 and 1.1% for intra-day and inter-day precision, respectively. The LOD and LOQ are 0.7 and 2.3 mg/L, respectively. Similarly, for sulphate, a good linearity (R(2)=0.9996) and precision (RSD 0.4 and 0.6% for intra-day and inter-day, respectively) were obtained. PMID:21796785

  8. Avalanche mode of high-voltage overloaded p{sup +}–i–n{sup +} diode switching to the conductive state by pulsed illumination

    SciTech Connect

    Kyuregyan, A. S.

    2015-07-15

    A simple analytical theory of the picosecond switching of high-voltage overloaded p{sup +}–i–n{sup +} photodiodes to the conductive state by pulsed illumination is presented. The relations between the parameters of structure, light pulse, external circuit, and main process characteristics, i.e., the amplitude of the active load current pulse, delay time, and switching duration, are derived and confirmed by numerical simulation. It is shown that the picosecond light pulse energy required for efficient switching can be decreased by 6–7 orders of magnitude due to the intense avalanche multiplication of electrons and holes. This offers the possibility of using pulsed semiconductor lasers as a control element of optron pairs.

  9. A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas.

    PubMed

    Chen, Dong-Zhi; Sun, Yi-Ming; Han, Li-Mei; Chen, Jing; Ye, Jie-Xu; Chen, Jian-Meng

    2016-01-25

    Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria-Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10-0.19 h(-1); this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S(0), SO4(2-), and CO2. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200-400 mg/m(3) PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m(3) isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s. PMID:26476310

  10. Effect of various colors of light-emitting diodes (LEDs) on the biomass composition of Arthrospira platensis cultivated in semi-continuous mode.

    PubMed

    Markou, Giorgos

    2014-03-01

    In the present study, semi-continuous cultivation of Arthrospira platensis using various colors of light-emitting diodes (LEDs) as artificial lighting was performed in order to study their effects on the biomass composition of A. platensis. The lowest biomass productivity was obtained with blue LED (4.68 mg l(-1) day(-1)), while the highest was obtained with pink and red LEDs (30.89 and 30.69 mg l(-1) day(-1), respectively). All biomass compound contents were affected by the different colors studied, except that of total carotenoids. The lowest phycocyanin content was observed in pink LED (8.2%) while the maximum in blue LED (17.6 ± 2.4%). Chlorophyll content was lowest in red LED (1.04%) and highest in blue LED (1.42%). The highest protein content was obtained with white and green LEDs (50.1 and 49.8%, respectively), while the lowest was obtained with blue LED (42.1%). Carbohydrate content was contrarily affected as that of proteins. The highest carbohydrate content was obtained in blue LED (11.3%) and the lowest under white and pink LEDs (8.8 and 8.8%, respectively). Lipid content seems to follow the same trend as that of carbohydrates; the highest lipid content was obtained in blue LED (6.0%), and the lowest was obtained under pink LED (3.8%). PMID:24435766

  11. Room temperature plasmonic lasing in a continuous wave operation mode from an InGaN/GaN single nanorod with a low threshold

    PubMed Central

    Hou, Y.; Renwick, P.; Liu, B.; Bai, J.; Wang, T.

    2014-01-01

    It is crucial to fabricate nano photonic devices such as nanolasers in order to meet the requirements for the integration of photonic and electronic circuits on the nanometre scale. The great difficulty is to break down a bottleneck as a result of the diffraction limit of light. Nanolasers on a subwavelength scale could potentially be fabricated based on the principle of surface plasmon amplification by stimulated emission of radiation (SPASER). However, a number of technological challenges will have to be overcome in order to achieve a SPASER with a low threshold, allowing for a continuous wave (cw) operation at room temperature. We report a nano-SPASER with a record low threshold at room temperature, optically pumped by using a cw diode laser. Our nano-SPASER consists of a single InGaN/GaN nanorod on a thin SiO2 spacer layer on a silver film. The nanorod containing InGaN/GaN multi-quantum-wells is fabricated by means of a cost-effective post-growth fabrication approach. The geometry of the nanorod/dielectric spacer/plasmonic metal composite allows us to have accurate control of the surface plasmon coupling, offering an opportunity to determine the optimal thickness of the dielectric spacer. This approach will open up a route for further fabrication of electrically injected plasmonic lasers. PMID:24852881

  12. Investigating MALDI MSI parameters (Part 1) - A systematic survey of the effects of repetition rates up to 20kHz in continuous raster mode.

    PubMed

    Steven, Rory T; Dexter, Alex; Bunch, Josephine

    2016-07-15

    Recent developments in laser performance, combined with the desire for increases in detected ion intensity and throughput, have led to the adoption of high repetition-rate diode-pumped solid-state (DPSS) lasers in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI). Previous studies have demonstrated a more complex relationship between detected ion intensity, stage raster speed and laser pulse repetition rate than the simple linear relationship between number of pulses and detected ion intensity that might be expected. Here we report, for the first time, the interrelated influence of varying laser energy, repetition rate and stage raster speed on detected ion intensity. Thin films of PC 34:1 lipid standard and murine brain tissue with CHCA are analysed by continuous stage raster MALDI MSI. Contrary to previous reports, the optimum laser repetition rate is found to be dependent on both laser energy and stage raster speed and is found to be as high as 20kHz under some conditions. The effects of different repetition rates and raster speeds are also found to vary for different ion species within MALDI MSI of tissue and so may be significant when either targeting specific molecules or seeking to minimize bias. A clear dependence on time between laser pulses is also observed indicating the underlying mechanisms may be related to on-plate hysteresis-exhibiting processes such as matrix chemical modification. PMID:27080810

  13. Dual-Mode Combustion

    NASA Technical Reports Server (NTRS)

    Goyne, Christopher P.; McDaniel, James C.

    2002-01-01

    The Department of Mechanical and Aerospace Engineering at the University of Virginia has conducted an investigation of the mixing and combustion processes in a hydrogen fueled dual-mode scramjet combustor. The experiment essentially consisted of the "direct connect" continuous operation of a Mach 2 rectangular combustor with a single unswept ramp fuel injector. The stagnation enthalpy of the test flow simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and laser based diagnostics. These diagnostics included, pressure and wall temperature measurements, Fuel Plume Imaging (FPI) and Particle Image Velocimetry (PIV). A schematic of the combustor configuration and a summary of the measurements obtained are presented. The experimental work at UVa was parallel by Computational Fluid Dynamics (CFD) work at NASA Langley. The numerical and experiment results are compared in this document.

  14. Interface Conductance Modal Analysis

    NASA Astrophysics Data System (ADS)

    Gordiz, Kiarash; Henry, Asegun

    2015-03-01

    Reliably and quantitatively calculating the conductance of phonons across an interface between two materials has been one of the major unresolved questions in thermal transport physics for the last century. Theories have been presented in this regard, but their predictive power is limited. A new formalism to extract the modal contributions to thermal interface conductance with full inclusion of temperature dependent anharmonicity and all of the atom level topography is presented. The results indicate that when two materials are joined a new set of vibrational modes are required to correctly describe the transport across the interface. The new set of vibrational modes is inconsistent with the physical picture described by phonon gas model (PGM), because some of the most important modes are localized and non-propagating and therefore do not have a well-defined velocity nor do they impinge on the interface. Among these new modes, certain classifications emerge, as most modes extend at least partially into the other material. Localized interfacial modes are also present and exhibit a high conductance contribution on a per mode basis by strongly coupling to other types of vibrational modes. We apply our formalism to different interfaces and present thermal interface conductance accumulation functions, two-dimensional cross-correlation matrices, and a quantitative determination of the contributions arising from inelastic effects. The provided new perspective on interface thermal transport can open new gates towards deeper understanding of phonon-phonon and electron-phonon interactions around interfaces.

  15. Complete degradation of the azo dye Acid Orange-7 and bioelectricity generation in an integrated microbial fuel cell, aerobic two-stage bioreactor system in continuous flow mode at ambient temperature.

    PubMed

    Fernando, Eustace; Keshavarz, Taj; Kyazze, Godfrey

    2014-03-01

    In this study, the commercially used model azo dye Acid Orange-7 (AO-7) was fully degraded into less toxic intermediates using an integrated microbial fuel cell (MFC) and aerobic bioreactor system. The integrated bioreactor system was operated at ambient temperature and continuous-flow mode. AO-7 loading rate was varied during experiments from 70gm(-3)day(-1) to 210gm(-3)day(-1). Colour and soluble COD removal rates reached>90% under all AO-7 loading rates. The MFC treatment stage prompted AO-7 to undergo reductive degradation into its constituent aromatic amines. HPLC-MS analysis of metabolite extracts from the aerobic stage of the bioreactor system indicated further oxidative degradation of the resulting aromatic amines into simpler compounds. Bioluminescence based Vibrio fischeri ecotoxicity testing demonstrated that aerobic stage effluent exhibited toxicity reductions of approximately fivefold and ten-fold respectively compared to the dye wastewater influent and MFC-stage effluent. PMID:24495541

  16. Electrodeless conductivity.

    PubMed

    Light, T S; McHale, E J; Fletcher, K S

    1989-01-01

    Electrodeless conductivity is a technique for measuring the concentration of electrolytes in solution and utilizes a probe consisting of two toroids in close proximity, both of which are immersed in the solution. In special cases, the toroids may be mounted externally on insulated pipes carrying the solution. One toroid radiates an alternating electric field in the audiofrequency range and the other acts as a receiver to pick up the small current induced by the ions moving in a conducting loop of solution. Coatings which would foul contacting electrodes, such as suspensions, precipitates or oil, have little or no effect. Applications are chiefly to continuous measurement in the chemical processing industries, including pulp and paper, mining and heavy chemical production. The principles and practical details of the method are reviewed and cell-diameter, wall, and temperature effects are discussed. PMID:18964695

  17. Continuous Liquid Interface Production (CLIP)

    NASA Astrophysics Data System (ADS)

    Tumbleston, John

    Continuous liquid interface production (CLIP) can rapidly produce 3D parts using a range of polymeric materials. A DLP-based form of additive manufacturing, CLIP proceeds via projecting a sequence of UV images through an oxygen-permeable, UV-transparent window below a liquid resin bath. A thin uncured liquid layer, or dead zone, is created above the window and maintains a liquid interface below the advancing part. Above the dead zone, the curing part is drawn out of the resin bath creating suction forces that renew reactive liquid resin. The dead zone is created due to oxygen inhibition of photopolymerization, a process that is traditionally a nuisance in other photopolymerization applications. However, for CLIP oxygen inhibition and creation of the dead zone allows for a continuous mode of printing where UV exposure, resin renewal, and part elevation are conducted simultaneously. This continual process is fundamentally different from traditional bottom-up stereolithography printers where these steps must be conducted in separate and discrete steps. Furthermore, the relatively gentle nature of CLIP due to the established dead zone enables the use of unique materials with a wide range of mechanical properties. This presentation will showcase the CLIP technology and provide a detailed picture of interactions between different resin and process parameters. New applications for 3D printing that span the micro- to macro-scale enabled by CLIP's combination of unique materials and part production speed will also be presented.

  18. Conductance of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Datta, Supriyo; Anatram, M. P.

    1998-01-01

    The recent report of quantized conductance in a 4 m long multiwalled nanotube (MWNT) raises the exciting possibility of ballistic transport at room temperature over relatively long distances. We argue that this is made possible by the special symmetry of the eigenstates of the lowest propagating modes in metallic nanotubes which suppresses backscattering. This unusual effect is absent for the higher propagating modes so that transport is not ballistic once the bias exceeds the cut-off energy for the higher modes, which is estimated to be approximately 75 meV for nanotubes of diameter approximately 15 nm. Also, we show that the symmetry of the eigenstates can significantly affect their coupling to the reservoir and hence the contact resistance. A simple model is presented that can be used to understand the observed conductance-voltage characteristics.

  19. Section 1. Method of determining mode shapes and natural frequencies of the NASA unmodified test structure. Section 2. Continuous beam closed from solution to the NASA-LSS astromast torsional vibration, appendix E

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The methods used to determine the lower natural frequencies and their corresponding mode shapes of the NASA-LSS Astromast (Unmodified Test Structure), and the mass integrals associated with the mode shapes are illustrated. The test structure is modeled as a cantilever beam with 91 lumped masses and without the tip mass on the free end of the bram. This uncouples the torsion and bending modes and allows for them to be determined separately. The frequency range was limited to an upper bound of 100 rad/sec (15.92 Hz.). In this range from 0.-100. rad/sec, three bending frequencies and one torsion frequency was found.

  20. Continuous Problem of Function Continuity

    ERIC Educational Resources Information Center

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  1. Electrical Conductivity.

    ERIC Educational Resources Information Center

    Allen, Philip B.

    1979-01-01

    Examines Drude's classical (1900) theory of electrical conduction, details the objections to and successes of the 1900 theory, and investigates the Quantum (1928) theory of conduction, reviewing its successes and limitations. (BT)

  2. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part I: study of a synthesis procedure including solubilization of N-adamantyl-acrylamide via complex formation with a water-soluble cyclodextrin.

    PubMed

    Al-Massaedh, Ayat Allah; Pyell, Ute

    2013-04-19

    A new synthesis procedure for highly crosslinked macroporous amphiphilic N-adamantyl-functionalized mixed-mode acrylamide-based monolithic stationary phases for capillary electrochromatography (CEC) is investigated employing solubilization of the hydrophobic monomer by complexation with a cyclodextrin. N-(1-adamantyl)acrylamide is synthesized and characterized as a hydrophobic monomer forming a water soluble-inclusion complex with statistically methylated-β-cyclodextrin. The stoichiometry, the complex formation constant and the spatial arrangement of the formed complex are determined. Mixed-mode monolithic stationary phases are synthesized by in situ free radical copolymerization of cyclodextrin-solubilized N-adamantyl acrylamide, a water soluble crosslinker (piperazinediacrylamide), a hydrophilic monomer (methacrylamide), and a negatively charged monomer (vinylsulfonic acid) in aqueous medium in bind silane-pretreated fused silica capillaries. The synthesized monolithic stationary phases are amphiphilic and can be employed in the reversed- and in the normal-phase mode (depending on the composition of the mobile phase), which is demonstrated with polar and non-polar analytes. Observations made with polar analytes and polar mobile phase can only be explained by a mixed-mode retention mechanism. The influence of the total monomer concentration (%T) on the chromatographic properties, the electroosmotic mobility, and on the specific permeability is investigated. With a homologues series of alkylphenones it is confirmed that the hydrophobicity (methylene selectivity) of the stationary phase increases with increasing mass fraction of N-(1-adamantyl)acrylamide in the synthesis mixture. PMID:23489493

  3. Multi-mode horn

    NASA Technical Reports Server (NTRS)

    Neilson, Jeffrey M. (Inventor)

    2002-01-01

    A horn has an input aperture and an output aperture, and comprises a conductive inner surface formed by rotating a curve about a central axis. The curve comprises a first arc having an input aperture end and a transition end, and a second arc having a transition end and an output aperture end. When rotated about the central axis, the first arc input aperture end forms an input aperture, and the second arc output aperture end forms an output aperture. The curve is then optimized to provide a mode conversion which maximizes the power transfer of input energy to the Gaussian mode at the output aperture.

  4. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors. PMID:25618046

  5. STUDY OF A 10-MW CONTINUOUS SPALLATION NEUTRON SOURCE.

    SciTech Connect

    RUGGIERO,A.G.LUDEWIG,H.SHAPIRO,S.

    2003-05-12

    This paper reports on the feasibility study of a proton Super-Conducting Linac as the driver for an Accelerator-based Continuous Neutron Source (ACNS) [1] to be located at Brookhaven National Laboratory (BNL). The Linac is to be operated in the Continuous Wave (CW) mode to produce an average 10 MW of beam power. The Linac beam energy is taken to be 1.25 GeV. The required average proton beam intensity in exit is then 8 mA.

  6. Conduct disorder

    MedlinePlus

    Disruptive behavior - child; Impulse control problem - child ... Conduct disorder has been linked to: Child abuse Drug or alcohol abuse in the parents Family conflicts Genetic defects Poverty The diagnosis is more common among boys. It is ...

  7. Electrical Conductivity.

    ERIC Educational Resources Information Center

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  8. Calculus Student Understanding of Continuity

    ERIC Educational Resources Information Center

    Wangle, Jayleen Lillian

    2013-01-01

    Continuity is a central concept in calculus. Yet very few students seem to understand the nature of continuity. The research described was conducted in two stages. Students were asked questions in multiple choice and true/false format regarding function, limit and continuity. These results were used to identify participants as strong, weak or…

  9. Continuing Education Survey.

    ERIC Educational Resources Information Center

    Bird, K. A.; Fenwick, P. R.

    In 1978, a national survey was conducted in New Zealand to determine the extent of participation in continuing education and the level of unmet need for these activities. A questionnaire was developed dealing with respondent characteristics, spare time and interests, agency-directed learning activities (ADLAS), and unmet needs, and administered to…

  10. Preventing Fire Death and Injury, Conducting a Fire Drill in a Group Home [and] When You Need a Fire Safety Expert. National Fire Safety Certification System. Continuing Education Program. Volume 1, Numbers 1-3.

    ERIC Educational Resources Information Center

    Walker, Bonnie

    Three booklets provide fire safety information for staff of residential facilities serving people with developmental disabilities. Booklets focus on: (1) preventing fire death and injury, (2) conducting a fire drill in a group home, and (3) the role of fire safety experts. The first booklet stresses the elimination of the following dangers:…