WorldWideScience

Sample records for carriers by mode

  1. Distribution of carriers in gradient-doping transmission-mode GaAs photocathodes grown by molecular beam epitaxy

    Institute of Scientific and Technical Information of China (English)

    Zhang Yi-Jun; Chang Ben-Kang; Yang Zhi; Niu Jun; Zou Ji-Jun

    2009-01-01

    The gradient-doping structure is first applied to prepare the transmission-mode OaAs photocathode and the integral sensitivity of the sealed image tube achieves 1420μA/lm. This paper studies the inner carrier concentration distribution of the gradient-doping transmission-mode GaAs photocathode after molecular beam epitaxy (MBE) growth using the electrochemical capacitance-voltage profiling. The results show that an ideal gradient-doping structure can be obtained by using MBE growth. The total band-bending energy in the gradient-doping GaAs active-layer with doping concentration ranging from 1×10~(19) cm~(-3) to 1×10~(18) cm~(-3) is calculated to be 46.3 meV, which helps to improve the photoexcited electrons movement toward surface for the thin epilayer. In addition, by analysis of the band offsets, it is found that the worse carrier concentration discrepancy between GaAs and GaAlAs causes a lower back interface electron potential barrier which decreases the amount of high-energy photoelectrons and affects the short-wave response.

  2. 41 CFR 109-40.303-3 - Most fuel efficient carrier/mode.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Most fuel efficient...-3 Most fuel efficient carrier/mode. When more than one mode, or more than one carrier within a mode... cost, the carrier/mode determined to be the most fuel efficient will be selected. In determining...

  3. Photoionization of Trapped Carriers in Avalanche Photodiodes to Reduce Afterpulsing During Geiger-Mode Photon Counting

    Science.gov (United States)

    Krainak, Michael A.

    2005-01-01

    We reduced the afterpulsing probability by a factor of five in a Geiger-mode photon-counting InGaAs avalanche photodiode by using sub-band-gap (lambda = 1.95 micron) laser diode illumination, which we believe photoionizes the trapped carriers.

  4. Carrier diffusion and higher order transversal modes in spectral dynamics of the semiconductor laser

    DEFF Research Database (Denmark)

    Buus, Jens; Danielsen, Magnus

    1977-01-01

    The dynamic and spectral behavior of the semiconductor stripe laser has been investigated. For this purpose the rate equations have been generalized to include several longitudinal and transversal modes, spontaneous emission into the active modes, and position dependence of the electron density...... through a term describing the charge-carrier diffusion in the plane of the active layer. The parameters used for solving these equations are found by theoretical and experimental considerations. The results show a broadening of the spectrum together with a significant content of higher order transversal...

  5. Photo-excited charge carriers suppress sub-terahertz phonon mode in silicon at room temperature

    Science.gov (United States)

    Liao, Bolin; Maznev, A. A.; Nelson, Keith A.; Chen, Gang

    2016-01-01

    There is a growing interest in the mode-by-mode understanding of electron and phonon transport for improving energy conversion technologies, such as thermoelectrics and photovoltaics. Whereas remarkable progress has been made in probing phonon–phonon interactions, it has been a challenge to directly measure electron–phonon interactions at the single-mode level, especially their effect on phonon transport above cryogenic temperatures. Here we use three-pulse photoacoustic spectroscopy to investigate the damping of a single sub-terahertz coherent phonon mode by free charge carriers in silicon at room temperature. Building on conventional pump–probe photoacoustic spectroscopy, we introduce an additional laser pulse to optically generate charge carriers, and carefully design temporal sequence of the three pulses to unambiguously quantify the scattering rate of a single-phonon mode due to the electron–phonon interaction. Our results confirm predictions from first-principles simulations and indicate the importance of the often-neglected effect of electron–phonon interaction on phonon transport in doped semiconductors. PMID:27731406

  6. Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions

    Directory of Open Access Journals (Sweden)

    Morelli Michele

    2007-01-01

    Full Text Available This paper investigates the joint maximum likelihood (ML estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of affordable complexity that operates in a decoupled fashion. In particular, the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit.

  7. Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions

    Directory of Open Access Journals (Sweden)

    Michele Morelli

    2007-06-01

    Full Text Available This paper investigates the joint maximum likelihood (ML estimation of the carrier frequency offset, timing error, and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of affordable complexity that operates in a decoupled fashion. In particular, the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit.

  8. Supercontinuum generation and carrier envelope offset frequency measurement in a tapered single-mode fiber

    CERN Document Server

    Zhang, Long; Zhao, Yanying; Hou, Lei; Yu, Zijiao; Wei, Zhiyi

    2014-01-01

    We report supercontinuum generation by launching femtosecond Yb fiber laser pulses into a tapered single-mode fiber of 3 um core diameter. A spectrum of more than one octave, from 550 to 1400 nm, has been obtained with an output power of 1.3 W at a repetition rate of 250 MHz, corresponding to a coupling efficiency of up to 60%. By using a typical f-2f interferometer, the carrier envelope offset frequency was measured and found to have a signal-to-noise ratio of nearly 30 dB.

  9. Carriers by chemical vapor deposition

    Science.gov (United States)

    Mronga, Norbert; Adel, J.; Czech, Erwin

    1990-07-01

    Printed materials are affecting people's lives in a variety of ways and to a constantly increasing extent, both in the private and in the business spheres. In particular, the predicted reduction of printed materials resulting from electronic data processing - the so-called "paperless electronic office" - has not occured, indeed quite the reverse. In recent years electrophotographic reprography has established itself successfully as a competitor to conventional printing processes. In the office a photocopier is now a part of the standard equipment. Because of BASF's traditional intensive involvement with pigments and colored printing inks its interest in new technologies in these areas is especially great. BASF has therefore been engaged in research on carriers for some years now.

  10. Multi Carrier Modulator for Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment, in particular radio receivers. Lowering the EMI of swit...

  11. Carrier-Based Common Mode Voltage Control Techniques in Three-Level Diode-Clamped Inverter

    Directory of Open Access Journals (Sweden)

    Pradyumn Chaturvedi

    2012-01-01

    Full Text Available Switching converters are used in electric drive applications to produce variable voltage, variable frequency supply which generates harmful large dv/dt and high-frequency common mode voltages (CMV. Multilevel inverters generate lower CMV as compared to conventional two-level inverters. This paper presents simple carrier-based technique to control the common mode voltages in multilevel inverters using different structures of sine-triangle comparison method such as phase disposition (PD, phase opposition disposition (POD by adding common mode voltage offset signal to actual reference voltage signal. This paper also presented the method to optimize the magnitude of this offset signal to reduce CMV and total harmonic distortion in inverter output voltage. The presented techniques give comparable performance as obtained in complex space vector-based control strategy, in terms of number of commutations, magnitude, and rate of change of CMV and harmonic profile of inverter output voltage. Simulation and experimental results presented confirm the effectiveness of the proposed techniques to control the common mode voltages.

  12. Specific features of quasineutral carrier transport modes in semiconductors and semiconductor structures

    Science.gov (United States)

    Mnatsakanov, T. T.; Tandoev, A. G.; Yurkov, S. N.; Levinshtein, M. E.

    2009-07-01

    It has been demonstrated that the field dependence of the electron and hole mobility strongly affects the carrier distribution in semiconductor structures under quasineutral conditions. Taking into account this phenomenon, a new equation for quasineutral carrier transport in semiconductors and semiconductor structures has been suggested. The concept of the critical current density jcr has been introduced and validated. At j Lt jcr, the suggested equation transforms to the well-known 'classical' equation of quasineutral transport. By contrast, at j > jcr, novel solutions become apparent from the suggested equation. The performed analysis gives insight into what happens in regions in which the quasineutral drift and DSQD (diffusion stimulated by quasineutral drift) modes predominate. Analytical expressions have been derived for the dependences of the voltage drops across the quasineutral drift and DQSD regions on current. It has been shown that, at high current densities, the voltage drop across the DSQD region tends to decrease as the current density increases. The results obtained enable a qualitative interpretation of the negative differential conductivity region in the current-voltage characteristic of forward-biased semiconductor structures, which arises at high current densities.

  13. Ultrafast non-equilibrium carrier dynamics in semiconductor laser mode-locking

    Science.gov (United States)

    Hader, J.; Scheller, M.; Laurain, A.; Kilen, I.; Baker, C.; Moloney, J. V.; Koch, S. W.

    2017-01-01

    Experimental and theoretical results on the mode-locking dynamics in vertical-external-cavity surface-emitting lasers with semiconductor and graphene saturable absorber mirrors are reviewed with an emphasis on the role of nonequilibrium carrier effects. The systems are studied theoretically using a fully microscopic many-body model for the carrier distributions and polarizations, coupled to Maxwell’s equations for the field propagation. Pump-probe measurements are performed with (sub-) 100 fs resolution. The analysis shows that the non-equilibrium carrier dynamics in the gain quantum-wells and saturable absorber medium significantly influences the system’s response and the resulting mode-locked pulses. The microscopic model is used to study the pulse build up from spontaneous emission noise and to determine the dependence of achievable pulse lengths and fluences on the amounts of saturable and non-saturable losses and the optical gain. The change of the group delay dispersion (GDD) on the pump level is examined and the dependence of the pulse lengths on the total amount of GDD is demonstrated experimentally. Theory-experiment comparisons are used to demonstrate the highly quantitative accuracy of the fully microscopic modeling.

  14. Hardware Trojan by Hot Carrier Injection

    CERN Document Server

    Shiyanovskii, Y; Papachristou, C; Weyer, D; Clay, W

    2009-01-01

    This paper discusses how hot carrier injection (HCI) can be exploited to create a trojan that will cause hardware failures. The trojan is produced not via additional logic circuitry but by controlled scenarios that maximize and accelerate the HCI effect in transistors. These scenarios range from manipulating the manufacturing process to varying the internal voltage distribution. This new type of trojan is difficult to test due to its gradual hardware degradation mechanism. This paper describes the HCI effect, detection techniques and discusses the possibility for maliciously induced HCI trojans.

  15. 19 CFR 18.2 - Receipt by carrier; manifest.

    Science.gov (United States)

    2010-04-01

    ... TREASURY TRANSPORTATION IN BOND AND MERCHANDISE IN TRANSIT General Provisions § 18.2 Receipt by carrier... Carrier (or Exporter) Attorney-in-fact or Agent of Carrier (or Exporter) Date (3) Merchandise delivered... prescribed in subpart D of part 123 of this chapter, relating to merchandise in transit through the...

  16. Advanced two-way satellite frequency transfer by carrier-phase and carrier-frequency measurements

    Science.gov (United States)

    Fujieda, Miho; Gotoh, Tadahiro; Amagai, Jun

    2016-06-01

    Carrier-phase measurement is one of the ways to improve the measurement resolution of two-way satellite frequency transfer. We introduce two possible methods for carrier-phase measurement: direct carrier-phase detection identified by Two-Way Carrier-Phase (TWCP) and the use of carrier-frequency information identified by Two-Way Carrier Frequency (TWCF). We performed the former using an arbitrary waveform generator and an analog-to-digital sampler and the latter using a conventional modem. The TWCF measurement using the modem had a resolution of 10-13 and the result agreed with that obtained by GPS carrier-phase frequency transfer in a 1500 km baseline. The measurement accuracy may have been limited by the poor frequency resolution of the modem; however, the TWCF measurement was able to improve the stability of conventional two-way satellite frequency transfer. Additionally, we show that the TWCP measurement system has the potential to achieve a frequency stability of 10-17.

  17. A Silicon Micromachined Gyroscope Driven by the Rotating Carrier Self

    Institute of Scientific and Technical Information of China (English)

    Fuxue Zhang; Xu Mao; Yu Liu; Nan Zhang; Wei Zhang

    2006-01-01

    This paper reported a silicon micromachined gyroscope which is driven by the rotating carrier's angular velocity, the silicon was manufactured by anisotropy etching. The design, fabrication and packing of the sensing element were introduced in the paper. The imitation experimentation and performance test have certificated that the principle of the gyroscope is correct and the gyroscope can be used to sense yawing or pitching angular velocity of the rotating carrier, and the angular velocity of the rotating carrier itself.

  18. Depletion-mode carrier-plasma optical modulator in zero-change advanced CMOS.

    Science.gov (United States)

    Shainline, Jeffrey M; Orcutt, Jason S; Wade, Mark T; Nammari, Kareem; Moss, Benjamin; Georgas, Michael; Sun, Chen; Ram, Rajeev J; Stojanović, Vladimir; Popović, Miloš A

    2013-08-01

    We demonstrate the first (to the best of our knowledge) depletion-mode carrier-plasma optical modulator fabricated in a standard advanced complementary metal-oxide-semiconductor (CMOS) logic process (45 nm node SOI CMOS) with no process modifications. The zero-change CMOS photonics approach enables this device to be monolithically integrated into state-of-the-art microprocessors and advanced electronics. Because these processes support lateral p-n junctions but not efficient ridge waveguides, we accommodate these constraints with a new type of resonant modulator. It is based on a hybrid microring/disk cavity formed entirely in the sub-90 nm thick monocrystalline silicon transistor body layer. Electrical contact of both polarities is made along the inner radius of the multimode ring cavity via an array of silicon spokes. The spokes connect to p and n regions formed using transistor well implants, which form radially extending lateral junctions that provide index modulation. We show 5 Gbps data modulation at 1265 nm wavelength with 5.2 dB extinction ratio and an estimated 40 fJ/bit energy consumption. Broad thermal tuning is demonstrated across 3.2 THz (18 nm) with an efficiency of 291 GHz/mW. A single postprocessing step to remove the silicon handle wafer was necessary to support low-loss optical confinement in the device layer. This modulator is an important step toward monolithically integrated CMOS photonic interconnects.

  19. Nonlinear dynamics by mode superposition

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1976-01-01

    A mode superposition technique for approximately solving nonlinear initial-boundary-value problems of structural dynamics is discussed, and results for examples involving large deformation are compared to those obtained with implicit direct integration methods such as the Newmark generalized acceleration and Houbolt backward-difference operators. The initial natural frequencies and mode shapes are found by inverse power iteration with the trial vectors for successively higher modes being swept by Gram-Schmidt orthonormalization at each iteration. The subsequent modal spectrum for nonlinear states is based upon the tangent stiffness of the structure and is calculated by a subspace iteration procedure that involves matrix multiplication only, using the most recently computed spectrum as an initial estimate. Then, a precise time integration algorithm that has no artificial damping or phase velocity error for linear problems is applied to the uncoupled modal equations of motion. Squared-frequency extrapolation is examined for nonlinear problems as a means by which these qualities of accuracy and precision can be maintained when the state of the system (and, thus, the modal spectrum) is changing rapidly. The results indicate that a number of important advantages accrue to nonlinear mode superposition: (a) there is no significant difference in total solution time between mode superposition and implicit direct integration analyses for problems having narrow matric half-bandwidth (in fact, as bandwidth increases, mode superposition becomes more economical), (b) solution accuracy is under better control since the analyst has ready access to modal participation factors and the ratios of time step size to modal period, and (c) physical understanding of nonlinear dynamic response is improved since the analyst is able to observe the changes in the modal spectrum as deformation proceeds.

  20. Vibrational mode analysis of void induced coronene as a possible carrier of the astronomical aromatic infrared bands

    CERN Document Server

    Ota, Norio

    2015-01-01

    Void induced di-cation coronene C23H12++ is a possible carrier of the astronomically observed polycyclic aromatic hydrocarbon (PAH). Based on density functional theory, multiple spin state analysis was done for neutral void coronene C23H12. Singlet spin state was most stable (lowest total energy). By the Jahn-Teller effect, there occurs serious molecular deformation. Point group D6h of pure coronene transformed to C2 symmetry having carbon two pentagons. Advanced singlet stable molecules were di-cation C23H12++ and di-anion C23H12- -. Molecular configuration was almost similar with neutral C23H12. However, electric dipole moment of these two charged molecules show reversed direction with 1.19 and 2.63 Debey. Calculated infrared spectrum of C23H12++ show a very likeness to observed one of two astronomical sources of HD44179 and NGC7027. Harmonic vibrational mode analysis was done for C23H12++. At 3.2 micrometer, C-H stretching at pentagons was featured. From 6.4 to 8.7 micrometer, C-C stretching mode was obser...

  1. Carriers recombination processes in charge trapping memory cell by simulation

    Institute of Scientific and Technical Information of China (English)

    Song Yun-Cheng; Liu Xiao-Yan; Du Gang; Kang Jin-Feng; Han Ru-Qi

    2008-01-01

    We have evaluated the effects of recombination processes in a charge storage layer, either between trapped electrons and trapped holes or between trapped carriers and free carriers, on charge trapping memory cell's performances by numerical simulation. Recombination is an indispensable mechanism in charge trapping memory. It helps charge convert process between negative and positive charges in the charge storage layer during charge trapping memory programming/erasing operation. It can affect the speed of programming and erasing operations.

  2. Carrier doping by current injection into LaOFFeAs

    Energy Technology Data Exchange (ETDEWEB)

    Lazareva, Irina; Koval, Yury; Steiner, Christian; Mueller, Paul [Department of Physics, Universitaet Erlangen (Germany); Wurmehl, Sabine; Buechner, Bernd [IFW Dresden (Germany); Stuerzer, Tobias; Johrendt, Dirk [Department Chemie, LMU Muenchen (Germany)

    2013-07-01

    Recently, we were able to change the carrier concentration of hole-doped high-T{sub c} superconductors by injection of large currents along the c-axis. We extend this type of experiments to electron-doped pnictides. From our earlier interpretation we should expect that trapping of electrons caused by current injection would decrease the available carrier concentration. Indeed, by various experiments with superconductors from the LaO{sub 1-x}F{sub x}FeAs family we are able to show that trapped electrons caused by current injection perpendicular to the FeAs planes decrease the carrier concentration. We present a spectacular confirmation of this interpretation by the T{sub c} increase by more than 15 K in heavily overdoped La{sub 0.74}F{sub 0.26}FeAs. We performed similar experiments with the recently discovered 1048 layered pnictides of the composition Ca{sub 10}(FeAs){sub 10}(Pt{sub 4}As{sub 8}). The general tendency of carrier doping by trapped electrons was confirmed. A rather interesting discovery was the evolution of hysteretic c-axis IV-characteristics. This is a strong indication of intrinsic Josephson effects. We discuss these results in terms of a change of anisotropy by carrier doping.

  3. Mechanisms of Carrier Transport Induced by a Microswimmer Bath

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Andreas; Sokolov, Andrey; Aranson, Igor S.; Lowen, Hartmut

    2015-04-01

    Recently, it was found that a wedgelike microparticle (referred to as ”carrier”) which is only allowed to translate but not to rotate exhibits a directed translational motion along the wedge cusp if it is exposed to a bath of microswimmers. Here we model this effect in detail by resolving the microswimmers explicitly using interaction models with different degrees of mutual alignment. Using computer simulations we study the impact of these interactions on the transport efficiency of V-shaped carrier. We show that the transport mechanisms itself strongly depends on the degree of alignment embodied in the modelling of the individual swimmer dynamics. For weak alignment, optimal carrier transport occurs in the turbulent microswimmer state and is induced by swirl depletion inside the carrier. For strong aligning interactions, optimal transport occurs already in the dilute regime and is mediated by a polar cloud of swimmers in the carrier wake pushing the wedge-particle forward. We also demonstrate that the optimal shape of the carrier leading to maximal transport speed depends on the kind of interaction model used.

  4. Mode-by-mode hydrodynamics: Ideas and concepts

    Energy Technology Data Exchange (ETDEWEB)

    Floerchinger, Stefan

    2014-06-15

    The main ideas, technical concepts and perspectives for a mode resolved description of the hydrodynamical regime of relativistic heavy ion collisions are discussed. A background-fluctuation splitting and a Bessel–Fourier expansion for the fluctuating part of the hydrodynamical fields allows for a complete characterization of initial conditions, the fluid dynamical propagation of single modes, the study of interaction effects between modes, the determination of the associated particle spectra and the generalization of the whole program to event-by-event correlations and probability distributions.

  5. Line broadening caused by Coulomb carrier-carrier correlations and dynamics of carrier capture and emission in quantum dots

    DEFF Research Database (Denmark)

    Uskov, Alexander V; Magnúsdóttir, Ingibjörg; Tromborg, Bjarne;

    2001-01-01

    Mechanisms of pure dephasing in quantum dots due to Coulomb correlations and the dynamics of carrier capture and emission are suggested, and a phenomenological model for the dephasing is developed. It is shown that, if the rates of these capture and emission processes are sufficiently high...

  6. 49 CFR 1200.1 - Financial statements released by carriers.

    Science.gov (United States)

    2010-10-01

    ..., except in reports to this Board, based on generally accepted accounting principles for which there is... 49 Transportation 9 2010-10-01 2010-10-01 false Financial statements released by carriers. 1200.1... TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION (CONTINUED) ACCOUNTS, RECORDS AND REPORTS GENERAL...

  7. 77 FR 67613 - Patterns of Safety Violations by Motor Carrier Management

    Science.gov (United States)

    2012-11-13

    ... Federal Motor Carrier Safety Administration 49 CFR Parts 385 and 386 RIN 2126-AB42 Patterns of Safety Violations by Motor Carrier Management AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT... would enable the Agency to suspend or revoke the operating authority registration of motor carriers...

  8. Temperature dependence of carrier capture by defects in gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, William R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Modine, Normand A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    This report examines the temperature dependence of the capture rate of carriers by defects in gallium arsenide and compares two previously published theoretical treatments of this based on multi phonon emission (MPE). The objective is to reduce uncertainty in atomistic simulations of gain degradation in III-V HBTs from neutron irradiation. A major source of uncertainty in those simulations is poor knowledge of carrier capture rates, whose values can differ by several orders of magnitude between various defect types. Most of this variation is due to different dependence on temperature, which is closely related to the relaxation of the defect structure that occurs as a result of the change in charge state of the defect. The uncertainty in capture rate can therefore be greatly reduced by better knowledge of the defect relaxation.

  9. PAPR Reduction in OFDM Systems with Large Number of Sub-Carriers by Carrier Interferometry Approaches

    Institute of Scientific and Technical Information of China (English)

    HE Jian-hui; QUAN Zi-yi; MEN Ai-dong

    2004-01-01

    High Peak-to-Average Power Ratio (PAPR) is one of the major drawbacks of Orthogonal Frequency Division Multiplexing ( OFDM) systems. This paper presents the structures of the particular bit sequences leading to the maximum PAPR (PAPRmax) in Carrier-Interferometry OFDM (CI/OFDM) and Pseudo Orthogonal Carrier-Interferometry OFDM (PO-CI/OFDM) systems for Binary Phase Shift Keying (BPSK) modulation. Furthermore, the simulation and analysis of PAPRmax and PAPR cumulative distribution in CI/OFDM and PO-CI/OFDM systems with 2048 sub-carriers are presented in this paper. The results show that the PAPR of OFDM system with large number of sub-carriers reduced evidently via CI approaches.

  10. Surface Depletion Correction to Carrier Profiles by Hall Measurements.

    Science.gov (United States)

    1985-12-01

    electrically active carriers below the surface per unit surface area. Next, a thin layer of the implanted material is removed by a chemical etch. A...3Y 2 ) bo A’ 64 b -- (2j8 3 2 -6) 2 A where A = 10$ - 12)Y2 -18. Equation (3) may now be integrated to obtain an analitic V.-’.4 function, in terms of

  11. Improved charge carrier lifetime in planar perovskite solar cells by bromine doping

    OpenAIRE

    Kiermasch, David; Rieder, Philipp; Tvingstedt, Kristofer; Baumann, Andreas; Dyakonov, Vladimir

    2016-01-01

    The charge carrier lifetime is an important parameter in solar cells as it defines, together with the mobility, the diffusion length of the charge carriers, thus directly determining the optimal active layer thickness of a device. Herein, we report on charge carrier lifetime values in bromine doped planar methylammonium lead iodide (MAPbI3) solar cells determined by transient photovoltage. The corresponding charge carrier density has been derived from charge carrier extraction. We found incre...

  12. A 3.96 GHz phase-locked loop for mode-1 MB-OFDM UWB hopping carrier generation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Yongzheng; Li Weinan; Xia Lingli; Huang Yumei; Hong Zhiliang, E-mail: yumeihuang@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-07-15

    A fully integrated phase-locked loop (PLL) is presented for a single quadrature output frequency of 3.96 GHz. The proposed PLL can be applied to mode-1 MB-OFDM UWB hopping carrier generation. An adaptive frequency calibration loop is incorporated into the PLL. The capacitance area in the loop filter is largely reduced through a capacitor multiplier. Implemented in a CMOS process, this PLL draws 13.0 mA current from a single 1.2 V supply while occupying 0.55 mm{sup 2} die area. Measurement results show that the PLL achieves a phase noise of-70 dBc/Hz at 10 kHz offset and -113 dBc/Hz at 1 MHz offset. The integrated RMS jitter from 1 kHz to 10 MHz is 2.2 ps. The reference spur level is less than -68 dBc.

  13. 12-core x 3-mode Dense Space Division Multiplexed Transmission over 40 km Employing Multi-carrier Signals with Parallel MIMO Equalization

    DEFF Research Database (Denmark)

    Mizuno, T.; Kobayashi, T.; Takara, H.;

    2014-01-01

    We demonstrate dense SDM transmission of 20-WDM multi-carrier PDM-32QAM signals over a 40-km 12-core x 3-mode fiber with 247.9-b/s/Hz spectral efficiency. Parallel MIMO equalization enables 21-ns DMD compensation with 61 TDE taps per subcarrier.......We demonstrate dense SDM transmission of 20-WDM multi-carrier PDM-32QAM signals over a 40-km 12-core x 3-mode fiber with 247.9-b/s/Hz spectral efficiency. Parallel MIMO equalization enables 21-ns DMD compensation with 61 TDE taps per subcarrier....

  14. Vi serology in screening of typhoid carriers: improved specificity by detection of Vi antibodies by counterimmunoelectrophoresis.

    OpenAIRE

    Chau, P. Y.; Tsang, R S

    1982-01-01

    A purified soluble Vi antigen was used in counterimmunoelectrophoresis (CIE), passive haemagglutination (HA) and solid phase radio-immunoassay (SPRIA) for detection of serum Vi antibody. Serum Vi antibody was detected in 13 of 14 chronic typhoid carriers by both CIE and HA. SPRIA studies showed that Vi antibodies in sera of these carriers were mainly of the IgG class. Successful treatment with amoxycillin in one carrier, who initially showed a positive Vi test, resulted in a reversion in 6 mo...

  15. Interchange mode excited by trapped energetic ions

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Seiya, E-mail: n-seiya@kobe-kosen.ac.jp [Kobe City College of Technology, Kobe, Hyogo 651-2194 (Japan)

    2015-07-15

    The kinetic energy principle describing the interaction between ideal magnetohydrodynamic (MHD) modes with trapped energetic ions is revised. A model is proposed on the basis of the reduced ideal MHD equations for background plasmas and the bounce-averaged drift-kinetic equation for trapped energetic ions. The model is applicable to large-aspect-ratio toroidal devices. Specifically, the effect of trapped energetic ions on the interchange mode in helical systems is analyzed. Results show that the interchange mode is excited by trapped energetic ions, even if the equilibrium states are stable to the ideal interchange mode. The energetic-ion-induced branch of the interchange mode might be associated with the fishbone mode in helical systems.

  16. 14 CFR 399.12 - Negotiation by air carriers for landing rights in foreign countries.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Negotiation by air carriers for landing... Relating to Operating Authority § 399.12 Negotiation by air carriers for landing rights in foreign..., landing rights abroad for United States flag air carriers will be acquired through negotiation by the...

  17. Preparation of topological modes by Lyapunov control.

    Science.gov (United States)

    Shi, Z C; Zhao, X L; Yi, X X

    2015-09-08

    By Lyapunov control, we present a proposal to drive quasi-particles into a topological mode in quantum systems described by a quadratic Hamiltonian. The merit of this control is the individual manipulations on the boundary sites. We take the Kitaev's chain as an illustration for Fermi systems and show that an arbitrary excitation mode can be steered into the Majorana zero mode by manipulating the chemical potential of the boundary sites. For Bose systems, taking the noninteracting Su-Schrieffer-Heeger (SSH) model as an example, we illustrate how to drive the system into the edge mode. The sensitivity of the fidelity to perturbations and uncertainties in the control fields and initial modes is also examined. The experimental feasibility of the proposal and the possibility to replace the continuous control field with square wave pulses is finally discussed.

  18. 47 CFR 54.517 - Services provided by non-telecommunications carriers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Services provided by non-telecommunications carriers. 54.517 Section 54.517 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....517 Services provided by non-telecommunications carriers. (a) Non-telecommunications carriers shall...

  19. Even nanomechanical modes transduced by integrated photonics

    Energy Technology Data Exchange (ETDEWEB)

    Westwood-Bachman, J. N.; Diao, Z.; Sauer, V. T. K.; Hiebert, W. K., E-mail: wayne.hiebert@nrc-cnrc.gc.ca [Department of Physics, University of Alberta, Edmonton T6G 2E1 (Canada); National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada); Bachman, D. [Department of Electrical Engineering, University of Alberta, Edmonton T6G 2V4 (Canada)

    2016-02-08

    We demonstrate the actuation and detection of even flexural vibrational modes of a doubly clamped nanomechanical resonator using an integrated photonics transduction scheme. The doubly clamped beam is formed by releasing a straight section of an optical racetrack resonator from the underlying silicon dioxide layer, and a step is fabricated in the substrate beneath the beam. The step causes uneven force and responsivity distribution along the device length, permitting excitation and detection of even modes of vibration. This is achieved while retaining transduction capability for odd modes. The devices are actuated via optical force applied with a pump laser. The displacement sensitivities of the first through third modes, as obtained from the thermomechanical noise floor, are 228 fm Hz{sup −1/2}, 153 fm Hz{sup −1/2}, and 112 fm Hz{sup −1/2}, respectively. The excitation efficiency for these modes is compared and modeled based on integration of the uneven forces over the mode shapes. While the excitation efficiency for the first three modes is approximately the same when the step occurs at about 38% of the beam length, the ability to tune the modal efficiency of transduction by choosing the step position is discussed. The overall optical force on each mode is approximately 0.4 pN μm{sup −1} mW{sup −1}, for an applied optical power of 0.07 mW. We show a potential application that uses the resonant frequencies of the first two vibrational modes of a buckled beam to measure the stress in the silicon device layer, estimated to be 106 MPa. We anticipate that the observation of the second mode of vibration using our integrated photonics approach will be useful in future mass sensing experiments.

  20. 49 CFR 391.65 - Drivers furnished by other motor carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Drivers furnished by other motor carriers. 391.65 Section 391.65 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY...

  1. Spread Spectrum Modulation by Using Asymmetric-Carrier Random PWM

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Lungeanu, Florin; Sera, Dezso;

    2012-01-01

    This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on simulations and experimental measurements, it is shown that the spread effect of the discrete components from the motor current spectra and acoustic spectra i...

  2. Improvement of fluvastatin bioavailability by loading on nanostructured lipid carriers

    Directory of Open Access Journals (Sweden)

    El-Helw AR

    2015-09-01

    Full Text Available Abdel-Rahim M El-Helw, Usama A FahmyDepartment of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi ArabiaAbstract: The aim of this study is to prepare fluvastatin nanostructured lipid carriers (FLV-NLCs in order to find an innovative way to alleviate FLV-associated disadvantages. The limitations include poor solubility and extensive first-pass metabolism, resulting in low (30% bioavailability and short elimination half-life (1–3 hours. FLV-NLCs were prepared by hot emulsification–ultrasonication method. Ten runs were created by three-level factorial design (32 to optimize FLV-NLCs formulation process. In this study, two factors, four responses, and three-level factorial design were endorsed. The studied variables were lipid:oil ratio (X1 and sonication time (X2. However, the responses parameter determined the particle size (Y1, nm, entrapment efficiency percent (EE%, Y2, particles zeta potential (Y3, and 80% of the drug release after 24 hours (X4. Furthermore, stability and in vivo pharmacokinetics were studied in rats. The optimized consisted formula had an average particle size of 165 nm with 75.32% entrapment efficiency and 85.32% of drug released after 24 hours, demonstrating a sustaining drug release over 24 hours. An in vivo pharmacokinetic study revealed enhanced bioavailability by >2.64-fold, and the mean residence time was longer than that of FLV. We concluded that NLCs could be promising carriers for sustained/prolonged FLV release with enhanced oral bioavailability.Keywords: factorial design, nano-vesicles, hyperlipidemia, statins

  3. Thin layer Characterization by ZGV Lamb modes

    Energy Technology Data Exchange (ETDEWEB)

    Ces, Maximin; Clorennec, Dominique; Royer, Daniel; Prada, Claire, E-mail: maximin.ces@espci.fr [Laboratoire Ondes et Acoustique, ESPCI- Universite Paris 7- CNRS UMR 7587, 10 rue Vauquelin, 75231 Paris Cedex 05- France (France)

    2011-01-01

    Ultrasonic non-destructive testing of plates can be performed with Lamb modes guided by the structure. Non contact generation and detection of the elastic waves can be achieved with optical means such as a pulsed laser source and an interferometer. With this setup, we propose a method using zero group velocity (ZGV) Lamb modes rather than propagating modes. These ZGV modes have noteworthy properties, in particular their group velocity vanishes, whereas their phase velocity remains finite. Thus, a significant part of the energy deposited by the pulsed laser can be trapped in the source area. For example, in a homogeneous isotropic plate and at the minimum frequency of the S{sub 1}-Lamb mode a very sharp resonance can be observed, the frequency of which only depends on the plate thickness, for a given material. In fact, other ZGV modes exist and the set of ZGV resonance frequencies provide a local and absolute measurement of Poisson's ratio. These non-propagating modes can also be used to characterize multi-layered structures. Experimentally, we observed that a thin (500 nm) gold layer deposited on a thick (1.5 mm) Duralumin plate induces a sensitive down-shift of the set of ZGV resonance frequencies. This shift, which is typically 5 kHz for the S{sub 1}-Lamb mode at 1.924 MHz, can be approximated by a formula providing the layer thickness. Thickness down to 100 nm can be estimated by this method. Such a sensitivity with conventional ultrasound inspection by acoustic microscopy would require an operating frequency in the GHz range.

  4. Particle Distribution Modification by Low Amplitude Modes

    Energy Technology Data Exchange (ETDEWEB)

    White, R. B.; Gorelenkov, N.; Heidbrink, W. W.; Van Zeeland, M. A.

    2009-08-28

    Modification of a high energy particle distribution by a spectrum of low amplitude modes is investigated using a guiding center code. Only through resonance are modes effective in modifying the distribution. Diagnostics are used to illustrate the mode-particle interaction and to find which effects are relevant in producing significant resonance, including kinetic Poincare plots and plots showing those orbits with time averaged mode-particle energy transfer. Effects of pitch angle scattering and drag are studied, as well as plasma rotation and time dependence of the equilibrium and mode frequencies. A specific example of changes observed in a DIII-D deuterium beam distribution in the presence of low amplitude experimentally validated Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes is examined in detail. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam profile modification, and that the experimental amplitudes are only slightly above this threshold.

  5. Layer-by-layer microcapsules templated on erythrocyte ghost carriers.

    Science.gov (United States)

    Shaillender, Mutukumaraswamy; Luo, Rongcong; Venkatraman, Subbu S; Neu, Björn

    2011-08-30

    This work reports the fabrication of layer-by-layer (LbL) microcapsules that provide a simple mean for controlling the burst and subsequent release of bioactive agents. Red blood cell (RBC) ghosts were loaded with fluorescently labeled dextran and lysozyme as model compounds via hypotonic dialysis with an encapsulation efficiency of 27-31%. It is demonstrated that these vesicles maintain their shape and integrity and that a uniform distribution of the encapsulated agents within these carriers is achieved. The loaded vesicles were then successfully coated with the biocompatible polyelectrolytes, poly-L-arginine hydrochloride and dextran sulfate. It is demonstrated that the release profiles of the encapsulated molecules can be regulated over a wide range by adjusting the number of polyelectrolyte layers. In addition, the LbL shell also protects the RBC ghost from decomposition thereby potentially preserving the bioactivity of encapsulated drugs or proteins. These microcapsules, consisting of an RBC ghost coated with a polyelectrolyte multilayer, provide a simple mean for the preparation of loaded LbL microcapsules eliminating the core dissolution and post-loading of bioactive agents, which are required for conventional LbL microcapsules.

  6. Review on the delivery of steroids by carrier proteins.

    Science.gov (United States)

    Chanphai, P; Vesper, A R; Bariyanga, J; Bérubé, G; Tajmir-Riahi, H A

    2016-08-01

    Due to the poor solubility of steroids in aqueous solution, delivery of these biomaterials is of major biomedical importance. We have reviewed the conjugation of testosterone and it aliphatic dimer and aromatic dimer with several carrier proteins, human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. The results of multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were compared here. Steroid-protein bindings are via hydrophilic and H-bonding contacts. HSA forms more stable conjugate than BSA and b-LG. The stability of steroid-protein conjugates is testosterone>dimer-aromatic>dimer-aliphatic. Encapsulation of steroids by protein is shown by TEM images. Modeling showed the presence of H-bonding, which stabilized testosterone-protein complexes with the free binding energy of -12.95 for HSA and -11.55 for BSA and -8.92kcal/mol for b-LG conjugates. Steroid conjugation induced major perturbations of serum protein conformations. Serum proteins can transport steroids to the target molecules.

  7. Magnetohydrodynamic waves driven by p-modes

    CERN Document Server

    Khomenko, Elena

    2013-01-01

    Waves are observed at all layers of the solar atmosphere and the magnetic field plays a key role in their propagation. While deep down in the atmosphere the p-modes are almost entirely of acoustic nature, in the upper layers magnetic forces are dominating, leading to a large variety of new wave modes. Significant advances have been made recently in our understanding of the physics of waves interaction with magnetic structures, with the help of analytical theories, numerical simulations, as well as high-resolution observations. In this contribution, we review recent observational findings and current theoretical ideas in the field, with an emphasis on the following questions: (i) Peculiarities of the observed wave propagation in network, plage and facular regions; (ii) Role of the mode transformation and observational evidences of this process; (iii) Coupling of the photosphere, chromosphere, and above by means of waves propagating in magnetic structures.

  8. Carrier synchronization for STBC OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Cai Jueping; Song Wentao; Li Zan; Ge Jianhua

    2005-01-01

    All-digital carrier synchronization strategies and algorithms for space-time block coding (STBC) orthogonal frequency division multiplexing (OFDM) are proposed in this paper. In our scheme, the continuous pilots (CP) are saved, and the complexity of carrier synchronization is reduced significantly by dividing the process into three steps. The coarse carrier synchronization and the fine carrier synchronization algorithms are investigated and analyzed in detail. Simulations show that the carrier can be locked into tracking mode quickly, and the residual frequency error satisfies the system requirement in both stationary and mobile environments.

  9. Heating subsurface formations by oxidizing fuel on a fuel carrier

    Energy Technology Data Exchange (ETDEWEB)

    Costello, Michael; Vinegar, Harold J.

    2012-10-02

    A method of heating a portion of a subsurface formation includes drawing fuel on a fuel carrier through an opening formed in the formation. Oxidant is supplied to the fuel at one or more locations in the opening. The fuel is combusted with the oxidant to provide heat to the formation.

  10. Intrinsic carrier multiplication efficiency in bulk Si crystals evaluated by optical-pump/terahertz-probe spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, G.; Nagai, M., E-mail: mnagai@mp.es.osaka-u.ac.jp, E-mail: ashida@mp.es.osaka-u.ac.jp; Ashida, M., E-mail: mnagai@mp.es.osaka-u.ac.jp, E-mail: ashida@mp.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, Osaka 560-8531 (Japan); Matsubara, E. [Graduate School of Engineering Science, Osaka University, Osaka 560-8531 (Japan); Department of Physics, Osaka Dental University, Hirakata, Osaka 573-1121 (Japan); Kanemitsu, Y. [Institute for Chemical Research, Kyoto University, Kyoto 611-0011 (Japan)

    2014-12-08

    We estimated the carrier multiplication efficiency in the most common solar-cell material, Si, by using optical-pump/terahertz-probe spectroscopy. Through close analysis of time-resolved data, we extracted the exact number of photoexcited carriers from the sheet carrier density 10 ps after photoexcitation, excluding the influences of spatial diffusion and surface recombination in the time domain. For incident photon energies greater than 4.0 eV, we observed enhanced internal quantum efficiency due to carrier multiplication. The evaluated value of internal quantum efficiency agrees well with the results of photocurrent measurements. This optical method allows us to estimate the carrier multiplication and surface recombination of carriers quantitatively, which are crucial for the design of the solar cells.

  11. Large-amplitude chirped coherent phonons in tellurium mediated by ultrafast photoexcited carrier diffusion

    Science.gov (United States)

    Kamaraju, N.; Kumar, Sunil; Anija, M.; Sood, A. K.

    2010-11-01

    We report femtosecond time-resolved reflectivity measurements of coherent phonons in tellurium performed over a wide range of temperatures (3-296 K) and pump-laser intensities. A totally symmetric A1 coherent phonon at 3.6 THz responsible for the oscillations in the reflectivity data is observed to be strongly positively chirped (i.e., phonon time period decreases at longer pump-probe delay times) with increasing photoexcited carrier density, more so at lower temperatures. We show that the temperature dependence of the coherent phonon frequency is anomalous (i.e, increasing with increasing temperature) at high photoexcited carrier density due to electron-phonon interaction. At the highest photoexcited carrier density of ˜1.4×1021cm-3 and the sample temperature of 3 K, the lattice displacement of the coherent phonon mode is estimated to be as high as ˜0.24Å . Numerical simulations based on coupled effects of optical absorption and carrier diffusion reveal that the diffusion of carriers dominates the nonoscillatory electronic part of the time-resolved reflectivity. Finally, using the pump-probe experiments at low carrier density of 6×1018cm-3 , we separate the phonon anharmonicity to obtain the electron-phonon coupling contribution to the phonon frequency and linewidth.

  12. Charge carrier Density Imaging / IR lifetime mapping of Si wafers by Lock-In Thermography

    NARCIS (Netherlands)

    Van der Tempel, L.

    2012-01-01

    ABSTRACT Minority carrier lifetime imaging by lock-in thermography of passivated silicon wafers for photovoltaic cells has been developed for the public Pieken in de Delta project geZONd. CONCLUSIONS Minority carrier lifetime imaging by lock-in thermography of passivatedsilicon wafers is released t

  13. 47 CFR 54.501 - Eligibility for services provided by telecommunications carriers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Eligibility for services provided by telecommunications carriers. 54.501 Section 54.501 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... § 54.501 Eligibility for services provided by telecommunications carriers. (a)...

  14. 47 CFR 64.608 - Provision of hearing aid compatible telephones by exchange carriers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Provision of hearing aid compatible telephones... Provision of hearing aid compatible telephones by exchange carriers. In the absence of alternative suppliers in an exchange area, an exchange carrier must provide a hearing aid compatible telephone, as...

  15. 77 FR 55783 - Verification of Statements of Account Submitted by Cable Operators and Satellite Carriers

    Science.gov (United States)

    2012-09-11

    ... Satellite Carriers AGENCY: Copyright Office, Library of Congress. ACTION: Notice of proposed rulemaking... Account and royalty payments that are deposited with the Office by cable operators and satellite carriers... to audit the Statements of Account and royalty fees that cable operators and satellite...

  16. Carrier Noise Reduction in Speckle Correlation Interferometry by a Unique Averaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Pechersky, M.J.

    1999-01-20

    We present experimental result of carrier speckle noise averaging by a novel approach to generate numerous identical correlation fringes with randomly different speckles. The surface under study is sprayed with a new dry paint or a layer each time for the repetitive experiments to generate randomly different surfaces of the carrier speckle patterns.

  17. Improved charge carrier lifetime in planar perovskite solar cells by bromine doping

    Science.gov (United States)

    Kiermasch, David; Rieder, Philipp; Tvingstedt, Kristofer; Baumann, Andreas; Dyakonov, Vladimir

    2016-12-01

    The charge carrier lifetime is an important parameter in solar cells as it defines, together with the mobility, the diffusion length of the charge carriers, thus directly determining the optimal active layer thickness of a device. Herein, we report on charge carrier lifetime values in bromine doped planar methylammonium lead iodide (MAPbI3) solar cells determined by transient photovoltage. The corresponding charge carrier density has been derived from charge carrier extraction. We found increased lifetime values in solar cells incorporating bromine compared to pure MAPbI3 by a factor of ~2.75 at an illumination intensity corresponding to 1 sun. In the bromine containing solar cells we additionally observe an anomalously high value of extracted charge, which we deduce to originate from mobile ions.

  18. Carrier induced epitopic suppression of antibody responses induced by virus-like particles is a dynamic phenomenon caused by carrier-specific antibodies.

    Science.gov (United States)

    Jegerlehner, Andrea; Wiesel, Melanie; Dietmeier, Klaus; Zabel, Franziska; Gatto, Dominique; Saudan, Philippe; Bachmann, Martin F

    2010-07-26

    Pre-existing immunity against vaccine carrier proteins has been reported to inhibit the immune response against antigens conjugated to the same carrier by a process termed carrier induced epitopic suppression (CIES). Hence understanding the phenomenon of CIES is of major importance for the development of conjugate vaccines. Virus-like particles (VLPs) are a novel class of potent immunological carriers which have been successfully used to enhance the antibody response to virtually any conjugated antigen. In the present study we investigated the impact of a pre-existing VLP-specific immune response on the development of antibody responses against a conjugated model peptide after primary, secondary and tertiary immunization. Although VLP-specific immune responses led to reduced peptide-specific antibody titers, we showed that CIES against peptide-VLP conjugates could be overcome by high coupling densities, repeated injections and/or higher doses of conjugate vaccine. Furthermore we dissected VLP-specific immunity by adoptively transferring VLP-specific antibodies, B-cells or T(helper) cells separately into naïve mice and found that the observed CIES against peptide-VLP conjugates was mainly mediated by carrier-specific antibodies.

  19. Six-wave mixing induced by free-carrier plasma in silicon nanowire waveguides

    CERN Document Server

    Zhou, Heng; Huang, Shu-Wei; Zhou, Linjie; Qiu, Kun; Wong, Chee Wei

    2016-01-01

    Nonlinear wave mixing in mesoscopic silicon structures is a fundamental nonlinear process with broad impact and applications. Silicon nanowire waveguides, in particular, have large third-order Kerr nonlinearity, enabling salient and abundant four-wave-mixing dynamics and functionalities. Besides the Kerr effect, in silicon waveguides two-photon absorption generates high free-carrier densities, with corresponding fifth-order nonlinearity in the forms of free-carrier dispersion and free-carrier absorption. However, whether these fifth-order free-carrier nonlinear effects can lead to six-wave-mixing dynamics still remains an open question until now. Here we report the demonstration of free-carrier-induced six-wave mixing in silicon nanowires. Unique features, including inverse detuning dependence of six-wave-mixing efficiency and its higher sensitivity to pump power, are originally observed and verfied by analytical prediction and numerical modeling. Additionally, asymmetric sideband generation is observed for d...

  20. Nanowire Plasmon Excitation by Adiabatic Mode Transformation

    Science.gov (United States)

    Verhagen, Ewold; Spasenović, Marko; Polman, Albert; Kuipers, L. (Kobus)

    2009-05-01

    We show with both experiment and calculation that highly confined surface plasmon polaritons can be efficiently excited on metallic nanowires through the process of mode transformation. One specific mode in a metallic waveguide is identified that adiabatically transforms to the confined nanowire mode as the waveguide width is reduced. Phase- and polarization-sensitive near-field investigation reveals the characteristic antisymmetric polarization nature of the mode and explains the coupling mechanism.

  1. Seismic base isolation by nonlinear mode localization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [University of Illinois, Department of Civil and Environmental Engineering, Urbana, IL (United States); Washington University, Department of Civil and Environmental Engineering, St. Louis, MO (United States); McFarland, D.M. [University of Illinois, Department of Aerospace Engineering, Urbana, IL (United States); Vakakis, A.F. [National Technical University of Athens, Division of Mechanics (Greece); Bergman, L.A. [University of Illinois, Department of Mechanical and Industrial Engineering, Urbana, IL (United States)

    2005-03-01

    In this paper, the performance of a nonlinear base-isolation system, comprised of a nonlinearly sprung subfoundation tuned in a 1:1 internal resonance to a flexible mode of the linear primary structure to be isolated, is examined. The application of nonlinear localization to seismic isolation distinguishes this study from other base-isolation studies in the literature. Under the condition of third-order smooth stiffness nonlinearity, it is shown that a localized nonlinear normal mode (NNM) is induced in the system, which confines energy to the subfoundation and away from the primary or main structure. This is followed by a numerical analysis wherein the smooth nonlinearity is replaced by clearance nonlinearity, and the system is excited by ground motions representing near-field seismic events. The performance of the nonlinear system is compared with that of the corresponding linear system through simulation, and the sensitivity of the isolation system to several design parameters is analyzed. These simulations confirm the existence of the localized NNM, and show that the introduction of simple clearance nonlinearity significantly reduces the seismic energy transmitted to the main structure, resulting in significant attenuation in the response. (orig.)

  2. Enhanced cytotoxicity of anticancer drug delivered by novel nanoscale polymeric carrier

    Science.gov (United States)

    Stoika, R.; Boiko, N.; Senkiv, Y.; Shlyakhtina, Y.; Panchuk, R.; Finiuk, N.; Filyak, Y.; Bilyy, R.; Kit, Y.; Skorohyd, N.; Klyuchivska, O.; Zaichenko, A.; Mitina, N.; Ryabceva, A.

    2013-04-01

    We compared in vitro action of highly toxic anticancer drug doxorubicin under its delivery to the mammalian tumor cells in free form and after encapsulation in novel bio-functionalized nanoscale polymeric carrier. Such encapsulation was found to enhance significantly drug uptake by the targeted cells, as well as its cytotoxic action. 10 times higher cytotoxicity of the carrier-immobilized doxorubicin comparing to its free form was demonstrated by direct cell counting, and 5 times higher cytotoxicity of encapsulated doxorubicin was shown by FACS analysis. The polymeric carrier itself did not possess significant toxicity in vitro or in vivo (laboratory mice). The carrier protected against negative side effects of doxorubicin in mice with experimental NK/Ly lymphoma. The life duration of tumor-bearing animals treated with doxorubicin-carrier complex was significantly longer than life duration in animals treated with free doxorubicin. Besides, the effective treatment dose of the carrier-delivered doxorubicin in tumor-bearing mice was 10 times lower than such dose of free doxorubicin. Thus, novel nanoscale polymers possess high potential as drug carrier.

  3. Enhancing the carrier thermalization time in organometallic perovskites by halide mixing.

    Science.gov (United States)

    Madjet, Mohamed El-Amine; Akimov, Alexey V; El-Mellouhi, Fadwa; Berdiyorov, Golibjon R; Ashhab, Sahel; Tabet, Nouar; Kais, Sabre

    2016-02-21

    Hybrid metal-organic halide perovskites have recently attracted a great deal of attention because of their interesting electronic, optical and transport properties, which make them promising materials for high-performance, low-cost solar cells. Fundamental understanding of the formation mechanisms and dynamics of photoinduced charge carriers is essential for improving the performance of perovskite solar cell devices. For example, a significant amount of absorbed solar energy is lost as a result of carrier thermalization. This energy could be harnessed by extracting hot carriers before they cool down to the band edges. Although such hot carrier collection is experimentally challenging, theoretical investigations based on time-dependent methods can guide future experimental research by providing insights into the thermalization process. Here, we perform ab initio nonadiabatic molecular dynamics simulations to study non-radiative relaxation dynamics of charge carriers in hybrid halide perovskites. We find that the carrier relaxation time can be considerably increased by mixing halogen atoms in the perovskite materials. These findings show that simple approaches could be adopted to slow down the thermalization process of hot carriers in perovskite materials.

  4. Determining the flow regime in a biofilm carrier by means of magnetic resonance imaging.

    Science.gov (United States)

    Herrling, Maria P; Guthausen, Gisela; Wagner, Michael; Lackner, Susanne; Horn, Harald

    2015-05-01

    Biofilms on cylindrical carrier material originating from a lab-scale moving bed biofilm reactor (MBBR) were investigated by means of Magnetic Resonance Imaging (MRI). The aim of this study was to determine the local flow velocities at the inner face of the biofilm carrier. To get an insight into the mass transport processes, flow velocity maps of blank and with biofilm cultivated carriers were measured. A single carrier was placed in a tube in three different orientations and exposed to flow velocities of 0.21, 0.42, and 0.64 mm/s. The interplay of the biofilm morphology and the local flow pattern was then analyzed including the effect of the orientation of the carrier in relation to the upstream flow angle. Within this study, the biofilm carrier can be understood as an interconnected system of four sections in which the incoming fluid volume will be distributed depending on the biomass occupation and morphology. In sections with high biofilm occupation, the flow resistance is increased. Depending on the orientation of the carrier in the flow field, this effect leads to flow evasion through less covered sections showing higher flow velocities and consequently the risk of biofilm detachment. However, there was no clear correlation between biofilm coverage and flow ratio.

  5. Large-mode-area leaky optical fibre fabricated by MCVD

    OpenAIRE

    Dussardier, Bernard; Trzesien, Stanislaw; Ude, Michèle; Rastogi, Vipul; Kumar, Ajeet; Monnom, Gérard

    2008-01-01

    International audience; A large mode area single-mode optical fibre based on leaky mode filtering was prepared by MCVD. The cladding structure discriminates the fundamental mode from the higher order ones. A preliminary version has 25-µm core diameter and 0.11 numerical aperture. A Gaussian-like mode with 22-µm MFD is observed after 3-m propagation, in agreement with modeling.

  6. Enhancement of carrier mobility in thin Ge layer by Sn co-doping

    Science.gov (United States)

    Prucnal, S.; Liu, F.; Berencén, Y.; Vines, L.; Bischoff, L.; Grenzer, J.; Andric, S.; Tiagulskyi, S.; Pyszniak, K.; Turek, M.; Drozdziel, A.; Helm, M.; Zhou, S.; Skorupa, W.

    2016-10-01

    We present the development, optimization and fabrication of high carrier mobility materials based on GeOI wafers co-doped with Sn and P. The Ge thin films were fabricated using plasma-enhanced chemical vapour deposition followed by ion implantation and explosive solid phase epitaxy, which is induced by millisecond flash lamp annealing. The influence of the recrystallization mechanism and co-doping of Sn on the carrier distribution and carrier mobility both in n-type and p-type GeOI wafers is discussed in detail. This finding significantly contributes to the state-of-the-art of high carrier mobility-GeOI wafers since the results are comparable with GeOI commercial wafers fabricated by epitaxial layer transfer or SmartCut technology.

  7. Validating Inductive Hypotheses by Mode Inference

    Institute of Scientific and Technical Information of China (English)

    王志坚

    1993-01-01

    Sme criteria based on mode inference for validating inductive hypotheses are presented in this paper.Mode inference is caried out mechanically,thus such kind of validation can result in low overhead in consistency check and high efficiency in performance.

  8. Observation of resonant lattice modes by inelastic neutron scattering

    DEFF Research Database (Denmark)

    Bjerrum Møller, Hans; Mackintosh, A.R.

    1965-01-01

    Observation by inelastic neutron scattering of resonant lattice modes due to small concentration of W atoms in Cr host crystal; frequencies and lifetimes of phonons with frequencies near that of resonant mode are considerably affected by presence of defects....

  9. The Kinetics of Carrier Transport Inhibition

    DEFF Research Database (Denmark)

    Rosenberg, T.; Wilbrandt, Robert Walter

    1962-01-01

    The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing...... with the substrate for the enzyme or the carrier or for both, competing with the carrier for the enzyme, or non-competitive) and in the ability of penetrating the membrane. Experiments are reported on the inhibition of glucose and fructose transport across the human red cell membrane by phlorizine, phloretine...... the first order asymmetry severalfold (“second order asymmetry”). It was shown that a substrate competitive mode of action involving competition both for the enzyme and for the enzyme-bound carrier will result in a behaviour resembling the observed “second order asymmetry”. It is felt, therefore...

  10. PROMINENCE ACTIVATION BY CORONAL FAST MODE SHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takuya [Department of Astronomy, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Asai, Ayumi [Unit of Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Shibata, Kazunari, E-mail: takahashi@kwasan.kyoto-u.ac.jp [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

    2015-03-01

    An X5.4 class flare occurred in active region NOAA11429 on 2012 March 7. The flare was associated with a very fast coronal mass ejection (CME) with a velocity of over 2500 km s{sup −1}. In the images taken with the Solar Terrestrial Relations Observatory-B/COR1, a dome-like disturbance was seen to detach from an expanding CME bubble and propagated further. A Type-II radio burst was also observed at the same time. On the other hand, in extreme ultraviolet images obtained by the Solar Dynamic Observatory/Atmospheric Imaging Assembly (AIA), the expanding dome-like structure and its footprint propagating to the north were observed. The footprint propagated with an average speed of about 670 km s{sup −1} and hit a prominence located at the north pole and activated it. During the activation, the prominence was strongly brightened. On the basis of some observational evidence, we concluded that the footprint in AIA images and the ones in COR1 images are the same, that is, the MHD fast mode shock front. With the help of a linear theory, the fast mode Mach number of the coronal shock is estimated to be between 1.11 and 1.29 using the initial velocity of the activated prominence. Also, the plasma compression ratio of the shock is enhanced to be between 1.18 and 2.11 in the prominence material, which we consider to be the reason for the strong brightening of the activated prominence. The applicability of linear theory to the shock problem is tested with a nonlinear MHD simulation.

  11. Researches on active structural acoustic control by radiation modes

    Institute of Scientific and Technical Information of China (English)

    MAO Qibo; JIANG Zhe

    2001-01-01

    Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical meaning of the radiation modes are analyzed. The radiation efficiency of radiation mode falls off very rapidly with the increase of modes order at low frequency. A new control strategy is developed in which by canceling the adjoint coefficient of the first k radiation modes, the sound powers of the first k radiation modes is zero theoretically. The numerical calculation is made by using point force actuators as control forces.

  12. Microstructure of atmospheric particles revealed by TXM and a new mode of influenza virus transmission

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.M., E-mail: baoliangman@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhang, G.L., E-mail: zhangguilin@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Lei, Q.T.; Li, Y.; Li, X.L. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Hwu, Y.K. [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Yi, J.M. [Advanced Photon Source, Argonne National Laboratory, Argonne 60439 (United States)

    2015-09-15

    For control of influenza, firstly it is important to find the real virus transmission media. Atmospheric aerosol particles are presumably one of the media. In this study, three typical atmospheric inhaled particles in Shanghai were studied by the synchrotron based transmission X-ray microscopes (TXM). Three dimensional microstructure of the particles reveals that there are many pores contained in, particularly the coal combustion fly particles which may be possible virus carrier. The particles can transport over long distance and cause long-range infections due to its light weight. We suggest a mode which is droplet combining with aerosol mode. By this mode the transmission of global and pandemic influenzas and infection between inland avian far from population and poultry or human living in cities along coast may be explained.

  13. Beam Distribution Modification By Alfven Modes

    Energy Technology Data Exchange (ETDEWEB)

    White, R. B.; Gorelenkov, N.; Heidbrink, W. W.; Van Zeeland, M. A.

    2010-01-25

    Modification of a deuterium beam distribution in the presence of low amplitude Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes in a toroidal magnetic confinement device is examined. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam transport, and that the experimental amplitudes are only slightly above this threshold. The modes produce a substantial central flattening of the beam distribution.

  14. Beam Distribution Modification by Alfven Modes

    Energy Technology Data Exchange (ETDEWEB)

    White, R. B.; Gorelenkov, N.; Heidbrink, W. W.; Van Zeeland, M. A.

    2010-04-03

    Modification of a deuterium beam distribution in the presence of low amplitude Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes in a toroidal magnetic confinement device is examined. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam transport, and that the experimental amplitudes are only slightly above this threshold. The modes produce a substantial central flattening of the beam distribution.

  15. Carrier suppression in quadruple frequency modulation by cascaded optical external modulators for millimeter-wave generation

    Institute of Scientific and Technical Information of China (English)

    Xue Feng; Wei Zhang; Xiaoming Liu

    2009-01-01

    The optical carrier suppression in optical quadruple frequency modulation by cascaded external modulators is investigated theoretically and experimentally. Theoretical analysis demonstrates that the optical carrier suppression ratio is related with not only the initial phase difference of electrical signals applied on the two modulators, but also the optical phase shift between the two modulators. The maximum suppression ratio can be achieved when the total phase difference is equal to nπ+π/2(n=1,2…),which is verified by experiments. By properly controlling the total phase shift, 40-GHz millimeter-wave is generated by using a 10-GHz radio frequency (RF) source and the modulators.

  16. The influence of the carrier molecule on amoxicillin recognition by specific IgE in patients with immediate hypersensitivity reactions to betalactams.

    Science.gov (United States)

    Ariza, Adriana; Mayorga, Cristobalina; Salas, María; Doña, Inmaculada; Martín-Serrano, Ángela; Pérez-Inestrosa, Ezequiel; Pérez-Sala, Dolores; Guzmán, Antonio E; Montañez, María I; Torres, María J

    2016-10-12

    The optimal recognition of penicillin determinants, including amoxicillin (AX), by specific IgE antibodies is widely believed to require covalent binding to a carrier molecule. The nature of the carrier and its contribution to the antigenic determinant is not well known. Here we aimed to evaluate the specific-IgE recognition of different AX-derived structures. We studied patients with immediate hypersensitivity reactions to AX, classified as selective or cross-reactors to penicillins. Competitive immunoassays were performed using AX itself, amoxicilloic acid, AX bound to butylamine (AXO-BA) or to human serum albumin (AXO-HSA) in the fluid phase, as inhibitors, and amoxicilloyl-poli-L-lysine (AXO-PLL) in the solid-phase. Two distinct patterns of AX recognition by IgE were found: Group A showed a higher recognition of AX itself and AX-modified components of low molecular weights, whilst Group B showed similar recognition of both unconjugated and conjugated AX. Amoxicilloic acid was poorly recognized in both groups, which reinforces the need for AX conjugation to a carrier for optimal recognition. Remarkably, IgE recognition in Group A (selective responders to AX) is influenced by the mode of binding and/or the nature of the carrier; whereas IgE in Group B (cross-responders to penicillins) recognizes AX independently of the nature of the carrier.

  17. Carrier dynamics and terahertz photoconductivity of doped silicon measured by femtosecond pump-terahertz probe spectroscopy

    Institute of Scientific and Technical Information of China (English)

    ZHOU QingLi; SHI YuLei; LI Tong; JIN Bin; ZHAO DongMei; ZHANG CunLin

    2009-01-01

    The carrier dynamics and terahertz photoconductivity in the n-type silicon (n-Si) as well as in the p-type Silicon (pSi) have been investigated by using femtoaecond pump-terahertz probe technique. The measurements show that the relative change of terahertz transmission of p-Si at low pump power is slightly smaller than that of n-Si, due to the lower carrier density induced by the recombination of original holes in the p-type material and the photogenerated electrons. At high pump power, the bigger change of terahertz transmission of p-Si originates from the greater mobility of the carriers compared to n-Si. The transient photoconductivities are calculated and fit well with the Drude-Smith model, showing that the mobility of the photogenerated carriers decreases with the increasing pump power. The obtained results indicate that femtosecond pump-terahertz probe technique is a promising method to investigate the carrier dynamics of semiconductors.

  18. Carrier dynamics and terahertz photoconductivity of doped silicon measured by femtosecond pump-terahertz probe spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The carrier dynamics and terahertz photoconductivity in the n-type silicon (n-Si) as well as in the p-type Silicon (p-Si) have been investigated by using femtosecond pump-terahertz probe technique. The measurements show that the relative change of terahertz transmission of p-Si at low pump power is slightly smaller than that of n-Si,due to the lower carrier density induced by the recombination of original holes in the p-type material and the photogenerated electrons. At high pump power,the bigger change of terahertz transmission of p-Si originates from the greater mobility of the carriers compared to n-Si. The transient photoconductivities are calculated and fit well with the Drude-Smith model,showing that the mobility of the photogenerated carriers decreases with the increasing pump power. The obtained results indicate that femtosecond pump-terahertz probe technique is a promising method to investigate the carrier dynamics of semiconductors.

  19. Influence of carrier gas flow rate on carbon nanotubes growth by TCVD with Cu catalyst

    Directory of Open Access Journals (Sweden)

    S.A. Khorrami

    2016-07-01

    Full Text Available Carbon nanotubes (CNTs were grown on copper catalyst by thermal chemical vapor deposition (TCVD using H2 and N2 as carrier gases. CNTs with different morphologies were observed using different carrier gas flow rates. The influence of carrier gas flow rates on the structure of carbon nanotubes was compared. Catalyst nanolayer was sputtered on mirror polished silicon wafers. The catalyst film thickness was determined by using the Rutherford Back Scattering (RBS technique. Ethanol as carbon source has been used. The surface morphology and nanostructure were studied by Scanning Electron Microscopy (SEM, Raman Spectroscopy, Tunneling Electron Microscopy (TEM and Atomic Force Microscopy (AFM. Results indicated that the amounts of deposited carbon decrease with increasing flow rates. These results showed that CNTs’ length decreased with increasing flow rates. Results suggest that Cu nanolayer is suitable as catalyst due to the fact that CNTs are monotonous.

  20. The DSP-Carrier Board Used by the LEIR Low-Level RF System User's Manual

    CERN Document Server

    Angoletta, M E

    2007-01-01

    A new digital technology to implement beam control systems was tested in the PS Booster in 2004 and 2005 and commissioned in LEIR in 2006. The technology is based upon RF custom hardware that heavily exploits Digital Signal Processors (DSPs) and Field Programmable Gate Arrays (FPGAs) processing power. This architecture is extremely flexible in that it relies on a DSP-carrier board hosting one DSP and carrying different daughtercards. The LEIR beam control system deploys three DSP-carrier boards, which inter-communicate and exchange data continuously for the implementation of the various beam control loops. This user's manual for the DSP-carrier board, release 1.0 (EDA-00990-V1), was written in 2004 and has been used by CERN and BNL developers since then. It describes the DSP-carrier board hardware, user settings and FPGA software; hints on the DSP code used with the board are also given. An additional VME board, called Rear Transition Module, is described because it acts as a DSP-carrier board extension.

  1. Characterisation of spray dried soy sauce powders made by adding crystalline carbohydrates to drying carrier.

    Science.gov (United States)

    Wang, Wei; Zhou, Weibiao

    2015-02-01

    This study aimed to reduce stickiness and caking of spray dried soy sauce powders by introducing a new crystalline structure into powder particles. To perform this task, soy sauce powders were formulated by using mixtures of cellulose and maltodextrin or mixtures of waxy starch and maltodextrin as drying carriers, with a fixed carrier addition rate of 30% (w/v) in the feed solution. The microstructure, crystallinity, solubility as well as stickiness and caking strength of all the different powders were analysed and compared. Incorporating crystalline carbohydrates in the drying carrier could significantly reduce the stickiness and caking strength of the powders when the ratio of crystalline carbohydrates to maltodextrin was above 1:5 and 1:2, respectively. X-ray Diffraction (XRD) results showed that adding cellulose or waxy starch could induce the crystallinity of powders. Differential Scanning Calorimetry (DSC) results demonstrated that the native starch added to the soy sauce powders did not fully gelatinize during spray drying.

  2. Terahertz emission by diffusion of carriers and metal-mask dipole inhibition of radiation

    CERN Document Server

    Barnes, M E; Daniell, G J; Whitworth, G; Chung, A L; Quarterman, A H; Wilcox, K G; Beere, H E; Ritchie, D A; Apostolopoulos, V

    2011-01-01

    Terahertz (THz) radiation can be generated by ultrafast photo-excitation of carriers in a semiconductor partly masked by a gold surface. A simulation of the effect taking into account the diffusion of carriers and the electric field shows that the total net current is approximately zero and cannot account for the THz radiation. Finite element modelling and analytic calculations indicate that the THz emission arises because the metal inhibits the radiation from part of the dipole population, thus creating an asymmetry and therefore a net current. Experimental investigations confirm the simulations and show that metal-mask dipole inhibition can be used to create THz emitters.

  3. Optical security features by using information carrier digital screening

    Science.gov (United States)

    Koltai, Ferenc

    2002-04-01

    Jura is an Austrian-Hungarian company providing security printers with proprietary security printing design software, complete security printing pre=press systems (HW + SW), ultrahigh resolution image setters developed for security printing market, security features, developed by Jura for security printing in general, proprietary security features, destined for document personalization systems. In addition to supply such products Jura is providing its customers with full technical support, as integration, installation, training, hot-line remote and/or on-site support, service and maintenance worldwide. Research and development have always been in the focus of Jura's activity. Development and testing of new software, new security features are the most important parts of the work. Jura was the first on the world to release her Engraver Software enabling artist-engravers to create engraving-styled portraits digitally. This development, incompatibility with Jura's security design software package, enabled a full digital workflow for banknote origination. Jura made a lot of remarkable steps to develop security features also for Document Personalization. This development links the personal data with the photography of the document' holder by encoding personal data to the photography, invisibly for naked human eye, however, decodable by an appropriate decoding device. This feature exists also in machine-readable digital version. Experts of Jura started the research and development on digital screening 15 years ago for commercial printing and 10 years ago on special screens for security printing technologies. In very early stage of this development, when knowledge of creating each screen-dot individually in shape, form and position was acquired, the idea was born to use the screen dots as secondary data holder for encoded messages.

  4. 47 CFR 54.418 - Digital Television Transition Notices by Eligible Telecommunications Carriers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Digital Television Transition Notices by Eligible Telecommunications Carriers. 54.418 Section 54.418 Telecommunication FEDERAL COMMUNICATIONS... Low-Income Consumers § 54.418 Digital Television Transition Notices by Eligible...

  5. Stochastic resonance in a single-mode laser driven by frequency modulated signal and coloured noises

    Institute of Scientific and Technical Information of China (English)

    Jin Guo-Xiang; Zhang Liang-Ying; Cao Li

    2009-01-01

    By adding frequency modulated signals to the intensity equation of gain-noise model of the single-mode laser driven by two coloured noises which are correlated, this paper uses the linear approximation method to calculate the power spectrum and signal-to-noise ratio (SNR) of the laser intensity. The results show that the SNR appears typical stochastic resonance with the variation of intensity of the pump noise and quantum noise. As the amplitude of a modulated signal has effects on the SNR, it shows suppression, monotone increasing, stochastic resonance, and multiple stochastic resonance with the variation of the frequency of a carrier signal and modulated signal.

  6. Geoacoustic Inversion by Mode Amplitude Perturbation

    Science.gov (United States)

    2007-02-01

    Zee -" ", or AZn = -Z, (1- e -,r). For our purposes, it will often be best to look at the apparent change in the mode function over a small range...carried out in the Gulf of Mexico in February of 1999 [28], [29]. This experiment is somewhat different from the generic 47 version shown in figure 3.1...Development (LWAD) 99-1 SE Gulf of Mexico ." Naval Research Laboratory, (1998). [31] J. A. Goff and S. Nordtjord, "Interpolation of Fluvial Morphology

  7. 47 CFR 63.25 - Special provisions relating to temporary or emergency service by international carriers.

    Science.gov (United States)

    2010-10-01

    ... emergency service by international carriers. 63.25 Section 63.25 Telecommunication FEDERAL COMMUNICATIONS... apply: (1) Temporary service shall mean service for a period not exceeding 6 months; (2) Emergency... temporary service or emergency service must file their request with the Commission. Requests must set...

  8. Breast self-examination education for BRCA mutation carriers by clinical nurse specialists

    NARCIS (Netherlands)

    Visser, A.; Bos, W.C.; Prins, J.B.; Hoogerbrugge, N.; Laarhoven, H.W. van

    2015-01-01

    PURPOSE: Breast self-examination (BSE) may be beneficial for women with a BRCA1 or BRCA2 mutation. Therefore, these women are often advised to perform BSE. However, only 20% to 35% is performing BSE monthly, and proficiency levels are low. Recently diagnosed carriers are educated by a specially trai

  9. Increase of Carrier-to-Noise Ratio in GPS Receivers Caused by Continuous-Wave Interference

    Directory of Open Access Journals (Sweden)

    J. Li

    2016-09-01

    Full Text Available The increased use of personal private devices (PPDs is drawing greater attention to the effects of continuous-wave interference (CWI on the performance of global positioning system (GPS receivers. The effective carrier-to-noise density ratio (C/N0, an essential index of GNSS receiver performance, is studied in this paper. Receiver tracking performance deteriorates in the presence of interference. Hence, the effective C/N0, which measures tracking performance, decreases. However, simulations and bench tests have shown that the effective C/N0 may increase in the presence of CWI. The reason is that a sinusoidal signal is induced by the CWI in the correlator and may be tracked by the carrier tracking loop. Thus, the effective carrier power depends on the power of the signal induced by the CWI, and the effective C/N0 increases with the power of the CWI. The filtering of the CWI in the carrier tracking loop correlator and its effect on the phase locked loop (PLL tracking performance are analyzed. A mathematical model of the effect of the CWI on the effective C/N0 is derived. Simulation results show that the proposed model is more accurate than existing models, especially when the jam-to-signal ratio (JSR is greater than 30 dBc.

  10. Mode-by-mode fluid dynamics for relativistic heavy ion collisions

    CERN Document Server

    Floerchinger, Stefan

    2014-01-01

    We propose to study the fluid dynamic propagation of fluctuations in relativistic heavy ion collisions differentially with respect to their azimuthal, radial and longitudinal wavelength. To this end, we introduce a background-fluctuation splitting and a Bessel-Fourier decomposition of the fluctuating modes. We demonstrate how the fluid dynamic evolution of realistic events can be build up from the propagation of individual modes. We describe the main elements of this mode-by-mode fluid dynamics, and we discuss its use in the fluid dynamic analysis of heavy ion collisions. As a first illustration, we quantify to what extent only fluctuations of sufficiently large radial wave length contribute to harmonic flow coefficients. We find that fluctuations of short wave length are suppressed not only due to larger dissipative effects, but also due to a geometrical averaging over the freeze-out hyper surface. In this way, our study further substantiates the picture that harmonic flow coefficients give access to a coars...

  11. Charge Carrier Generation Followed by Triplet State Formation, Annihilation, and Carrier Recreation in PBDTTT-C:PC 60 BM Photovoltaic Blends

    KAUST Repository

    Gehrig, Dominik W.

    2015-05-22

    Triplet state formation after photoexcitation of low-bandgap polymer:fullerene blends has recently been demonstrated, however, the precise mechanism and its impact on solar cell performance is still under debate. Here, we study exciton dissociation, charge carrier generation and triplet state formation in low-bandgap polymer PBDTTT-C:PC60BM bulk heterojunction photovoltaic blends by a combination of fs-µs broadband Vis-NIR transient absorption (TA) pump-probe spectroscopy and multivariate curve resolution (MCR) data analysis. We found sub-ps exciton dissociation and charge generation followed by sub-ns triplet state creation. The carrier dynamics and triplet state dynamics exhibited a very pronounced intensity dependence indicating non-geminate recombination of free carriers is the origin of triplet formation in these blends. Triplets were found to be the dominant state present on the nanosecond timescale. Surprisingly, the carrier population increased again on the ns-µs timescale. We attribute this to triplet-triplet annihilation and the formation of higher energy excited states that subsequently underwent charge transfer. This unique dip and recovery of the charge population is a clear indication that triplets are formed by non-geminate recombination, as such a kinetic is incompatible with a monomolecular triplet state formation process.

  12. Multiple regimes of carrier cooling in photoexcited graphene probed by time-resolved terahertz spectroscopy

    Science.gov (United States)

    Frenzel, A. J.; Gabor, N. M.; Herring, P. K.; Fang, W.; Kong, J.; Jarillo-Herrero, P.; Gedik, N.

    2013-03-01

    Energy relaxation and cooling of photoexcited charge carriers in graphene has recently attracted significant attention due to possible hot carrier effects, large quantum efficiencies, and photovoltaic applications. However, the details of these processes remain poorly understood, with many conflicting interpretations reported. Here we use time-resolved terahertz spectroscopy to explore multiple relaxation and cooling regimes in graphene in order to elucidate the fundamental physical processes which occur upon photoexcitation of charge carriers. We observe a novel negative terahertz photoconductivity that results from the unique linear dispersion and allows us to measure the electron temperature with ultrafast time resolution. Additionally, we present measurements of the relaxation dynamics over a wide range of excitation fluence. By varying the pump photon energy, we demonstrate that cooling dynamics of photoexcited carriers depend on the amount of energy deposited in the graphene system by the pump pulse, not the number of absorbed photons. The data suggest that fundamentally different regimes are encountered for different excitation fluences. These results may provide a unifying framework for reconciling various measurements of energy relaxation and cooling in graphene.

  13. Antiviral activity produced by an IPNV-carrier EPC cell culture confers resistance to VHSV infection.

    Science.gov (United States)

    Jurado, María Teresa; García-Valtanen, Pablo; Estepa, Amparo; Perez, Luis

    2013-10-25

    Infectious pancreatic necrosis virus (IPNV), a fish birnavirus, can establish a persistent infection on epithelioma papulosum cyprinid (EPC) cells producing a carrier state where a small fraction of IPNV-infected cells is maintained in the culture after continuous subculture. The EPC(IPNV) cells are resistant to challenge with IPNV as well as to challenge with viral hemorrhagic septicemia virus (VHSV), a rhabdovirus. In this work, the antiviral effect of the IPNV carrier culture conditioned medium (EPC(IPNV)-CM) was tested and analyzed in detail. EPC cells treated with the carrier culture supernatant become protected against VHSV challenge. Size-fractionation by filtration and acid and heat treatment showed that the IPNV persistently infected cells release an acid-resistant soluble factor in the molecular weight fraction bellow 50 kDa. The capacity of the EPC(IPNV)-CM to induce cytokine genes in EPC cells was also determined by real-time RT-PCR. We found that there is a positive correlation between up-regulation of mx gene expression in EPC cells treated with EPC(IPNV)-CM and protection against VHSV challenge. Our findings indicate that the control of IPNV multiplication in the carrier culture as well as the interference with rhabdovirus replication are connected to the production and release of an antiviral (interferon-like) factor to the medium.

  14. Stellar evolution as seen by mixed modes

    Directory of Open Access Journals (Sweden)

    Mosser Benoît

    2015-01-01

    Full Text Available The detection of mixed modes in subgiants and red giants allows us to monitor stellar evolution from the main sequence to the asymptotic giant branch and draw seismic evolutionary tracks. Quantified asteroseismic definitions that characterize the change in the evolutionary stages have been defined. This seismic information can now be used for stellar modelling, especially for studying the energy transport in the helium burning core or for specifying the inner properties of stars all along their evolution. Modelling will also allow us to study stars identified in the helium subflash stage, high-mass stars either arriving or quitting the secondary clump, or stars that could be in the blue-loop stage.

  15. Role of free carriers excited by ultrafast Bessel beams for submicron structuring applications

    Science.gov (United States)

    Velpula, Praveen Kumar; Bhuyan, Manoj Kumar; Mauclair, Cyril; Colombier, Jean-Philippe; Stoian, Razvan

    2014-07-01

    Ultrafast Bessel beams are ideal sources for high aspect ratio submicron structuring applications because of their nondiffracting nature and higher stability in nonlinear propagation. We report here on the interaction of ultrafast Bessel beams at various laser energies and pulse durations with transparent materials (fused silica) and define their impact on photoinscription regimes, i.e., formation of positive and negative refractive index structures. The laser pulse duration was observed to be key in deciding the type of the structures via excitation efficiency. To understand the relevant mechanisms for forming these different structures, the free carrier behavior as a function of laser pulse duration and energy was studied by capturing instantaneous excitation profiles using time-resolved microscopy. Time-resolved imaging and simulation studies reveal that low carrier densities are generated for ultrashort pulses, leading to soft positive index alterations via presumably nonthermally induced structural transitions involving defects. On the other hand, the high free carrier density generation in the case of longer pulse durations leads to hydrodynamic expansion, resulting in high aspect ratio submicron-size wide voids. Delayed ionization, carrier defocusing, and lower nonlinear effects are responsible for the confinement of energy, resulting in efficient energy deposition on-axis.

  16. Carrier behavior of HgTe under high pressure revealed by Hall effect measurement

    Institute of Scientific and Technical Information of China (English)

    胡廷静; 崔晓岩; 李雪飞; 王婧姝; 吕秀梅; 王棱升; 杨景海; 高春晓

    2015-01-01

    We investigate the carrier behavior of HgTe under high pressures up to 23 GPa using in situ Hall effect measurements. As the phase transitions from zinc blende to cinnabar, then to rock salt, and finally to Cmcm occur, all the parameters change discontinuously. The conductivity variation under compression is described by the carrier parameters. For the zinc blende phase, both the decrease of carrier concentration and the increase of mobility indicate the overlapped valence band and conduction band separates with pressure. Pressure causes an increase in the hole concentration of HgTe in the cinnabar phase, which leads to the carrier-type inversion and the lowest mobility at 5.6 GPa. In the phase transition process from zinc blende to rock salt, Te atoms are the major ones in atomic movements in the pressure regions of 1.0–1.5 GPa and 1.8–3.1 GPa, whereas Hg atoms are the major ones in the pressure regions of 1.5–1.8 GPa and 3.1–7.7 GPa. The polar optical scattering of the rock salt phase decreases with pressure.

  17. Carrier dynamics in EuTiO3 films probed by femtosecond pump-probe spectroscopy

    Science.gov (United States)

    Li, Zhongguo; Zhao, Run; Li, Weiwei; Wang, Haiyan; Yang, Hao; Zhang, Xueru; Wang, Yuxiao; Wei, Tai-Huei; Song, Ying-Lin

    2015-03-01

    Recently, perovskite oxide EuTiO3 has attracted considerable attention due to its intriguing multiferroic properties. To gain a deeper understanding of its fascinating properties, it is essential to characterize the competing interactions between charge, lattice, spin, and orbital parameters. Here we present optical studies of the ultrafast carrier dynamics in EuTiO3 films grown on SrTiO3 substrates by probing photo-induced transient absorption (TA) in the weak excitation limit. All the signals were measured at room temperature. The transient curve of EuTiO3 exhibits a fast rise after photo excitation (approximately 2 ps) and a long decay component with time constant of several nanoseconds, which are attributed to carrier-phonon coupling and carrier recombination respectively. The absorption change of EuTiO3 near zero temporal delay is found to be quite different from the SrTiO3 substrates, implying carrier-phonon interactions differ distinctively between these two materials. Our results could be helpful to understand the microscopic interactions in perovskite oxide. The authors acknowledge the support of the National Natural Science Foundation of China.

  18. In vivo ectopic bone formation by devitalized mineralized stem cell carriers produced under mineralizing culture condition.

    Science.gov (United States)

    Chai, Yoke Chin; Geris, Liesbet; Bolander, Johanna; Pyka, Grzegorz; Van Bael, Simon; Luyten, Frank P; Schrooten, Jan

    2014-12-01

    Functionalization of tissue engineering scaffolds with in vitro-generated bone-like extracellular matrix (ECM) represents an effective biomimetic approach to promote osteogenic differentiation of stem cells in vitro. However, the bone-forming capacity of these constructs (seeded with or without cells) is so far not apparent. In this study, we aimed at developing a mineralizing culture condition to biofunctionalize three-dimensional (3D) porous scaffolds with highly mineralized ECM in order to produce devitalized, osteoinductive mineralized carriers for human periosteal-derived progenitors (hPDCs). For this, three medium formulations [i.e., growth medium only (BM1), with ascorbic acid (BM2), and with ascorbic acid and dexamethasone (BM3)] supplemented with calcium (Ca(2+)) and phosphate (PO4 (3-)) ions simultaneously as mineralizing source were investigated. The results showed that, besides the significant impacts on enhancing cell proliferation (the highest in BM3 condition), the formulated mineralizing media differentially regulated the osteochondro-related gene markers in a medium-dependent manner (e.g., significant upregulation of BMP2, bone sialoprotein, osteocalcin, and Wnt5a in BM2 condition). This has resulted in distinguished cell populations that were identifiable by specific gene signatures as demonstrated by the principle component analysis. Through devitalization, mineralized carriers with apatite crystal structures unique to each medium condition (by X-ray diffraction and SEM analysis) were obtained. Quantitatively, BM3 condition produced carriers with the highest mineral and collagen contents as well as human-specific VEGF proteins, followed by BM2 and BM1 conditions. Encouragingly, all mineralized carriers (after reseeded with hPDCs) induced bone formation after 8 weeks of subcutaneous implantation in nude mice models, with BM2-carriers inducing the highest bone volume, and the lowest in the BM3 condition (as quantitated by nano-computed tomography

  19. Carrier profiling of individual Si nanowires by scanning spreading resistance microscopy.

    Science.gov (United States)

    Ou, Xin; Kanungo, Pratyush Das; Kögler, Reinhard; Werner, Peter; Gösele, Ulrich; Skorupa, Wolfgang; Wang, Xi

    2010-01-01

    Individual silicon nanowires (NWs) doped either by ion implantation or by in situ dopant incorporation during NW growth were investigated by scanning spreading resistance microscopy (SSRM). The carrier profiles across the axial cross sections of the NWs are derived from the measured spreading resistance values and calibrated by the known carrier concentrations of the connected Si substrate or epi-layer. In the case of the phosphorus ion-implanted and subsequently annealed NWs, the SSRM profiles revealed a radial core-shell distribution of the activated dopants. The carrier concentration close to the surface of a phosphorus-doped NW is found to be by a factor of 6-7 higher than the value in the core and on average only 25% of the implanted phosphorus is electrically active. In contrast, for the in situ boron-doped NW the activation rate of the boron atoms is significantly higher than for phosphorus atoms. Some specific features of SSRM experiments of Si NWs are discussed including the possibility of three-dimensional measurements.

  20. Delivering DNA into Plant Cell by Gene Carriers of ZnS Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    FU Yu-qin; LI Lu-hua; WANG Pi-wu; QU Jing; FU Yong-ping; WANG Hui; SUN Jing-ran; L(U) Chang-li

    2012-01-01

    The development.of nanotechnology provides a new method for genetic engineering.However,the nanoparticles as gene carriers have been mainly used in the mammalian cells so far.We observed that ZnS nanoparticles modified with positively charged poly-L-lysine(PLL) successfully delivered GUS-encoding plasmid DNA into tobacco cells by means of ultrasound-assisted method.Polymerase chain reaction(PCR) detection,Southern blot analysis and GUS histochemical staining were carried out for the regenerated plants.The stable genetic modified plants mediated by ZnS nanoparticles can be obtained.This article demonstrates the great potential of nanoparticles as gene carrier in plant transformation and proves a novel approach for plant genetic decoration.

  1. Recombination of charge carriers on radiation-induced defects in silicon doped by transition metals impurities

    CERN Document Server

    Kazakevich, L A

    2003-01-01

    It has been studied the peculiarities of recombination of nonequilibrium charge carriers on radiation-induced defects in received according to Czochralski method p-silicon (p approx 3 - 20 Ohm centre dot cm), doped by one of the impurities of transition metals of the IV-th group of periodic table (titanium, zirconium, hafnium). Experimental results are obtained out of the analysis of temperature and injection dependence of the life time of charge carriers. The results are explained taking into consideration the influences of elastic stress fields created by the aggregates of transition metals atoms on space distribution over the crystal of oxygen and carbon background impurities as well as on the migration of movable radiation-induced defects during irradiation. (authors).

  2. Seismic diagnosis from gravity modes strongly affected by rotation

    CERN Document Server

    Prat, Vincent; Lignières, François; Ballot, Jérôme; Culpin, Pierre-Marie

    2016-01-01

    Most of the information we have about the internal rotation of stars comes from modes that are weakly affected by rotation, for example by using rotational splittings. In contrast, we present here a method, based on the asymptotic theory of Prat et al. (2016), which allows us to analyse the signature of rotation where its effect is the most important, that is in low-frequency gravity modes that are strongly affected by rotation. For such modes, we predict two spectral patterns that could be confronted to observed spectra and those computed using fully two-dimensional oscillation codes.

  3. Optimization of LDL targeted nanostructured lipid carriers of 5-FU by a full factorial design

    Directory of Open Access Journals (Sweden)

    Sare Andalib

    2012-01-01

    Full Text Available Background: Nanostructured lipid carriers (NLC are a mixture of solid and liquid lipids or oils as colloidal carrier systems that lead to an imperfect matrix structure with high ability for loading water soluble drugs. The aim of this study was to find the best proportion of liquid and solid lipids of different types for optimization of the production of LDL targeted NLCs used in carrying 5-Fu by the emulsification-solvent evaporation method. Materials and Methods: The influence of the lipid type, cholesterol or cholesteryl stearate for targeting LDL receptors, oil type (oleic acid or octanol, lipid and oil% on particle size, surface charge, drug loading efficiency, and drug released percent from the NLCs were studied by a full factorial design. Results: The NLCs prepared by 54.5% cholesterol and 25% of oleic acid, showed optimum results with particle size of 105.8 nm, relatively high zeta potential of −25 mV, drug loading efficiency of 38% and release efficiency of about 40%. Scanning electron microscopy of nanoparticles confirmed the results of dynamic light scattering method used in measuring the particle size of NLCs. Conclusions: The optimization method by a full factorial statistical design is a useful optimization method for production of nanostructured lipid carriers.

  4. Effects of Carrier Gas Conditions on Concentration of Alcohol Aqueous Solution by Ultrasonic Atomization

    Science.gov (United States)

    Yasuda, Keiji; Tanaka, Naofumi; Rong, Lei; Nakamura, Masaaki; Li, Li; Oda, Akiyoshi; Kawase, Yasuhito

    2003-05-01

    The effects of carrier gas conditions on the concentration of ethanol by ultrasonic atomization are examined. With increasing height from vessel bottom to gas inlet and outlet, the ethanol content in the accompanied liquid increases and the flow rate of alcohol decreases. The ethanol content in the accompanied liquid becomes lower as the gas velocity becomes higher. The attachment of a demister is effective for the increase of the content in the accompanied liquid.

  5. Assessment of the heat carrier movement in the primary coolant circuit by its own momentum

    Energy Technology Data Exchange (ETDEWEB)

    Kadalev, Stoyan, E-mail: kadalev@inrne.bas.bg

    2014-10-15

    Highlights: • We model the heat carrier flow alteration after the circulation pump(s) stop. • The general mathematical model used is described in details. • The model is adapted and applied to a particular example research reactor. • Assessment is presented in detail, step by step with references. • The information provided is enough to apply calculations to another facility. - Abstract: In the presented paper is considered the approach to an assessment of the heat carrier flow alteration in the primary water–water reactor coolant circuit after the circulation pump(s) stop. This topic is highly relevant trough advanced and increased nuclear safety requirements because such a process is observed in case of black-out accident or damaged pump(s). The general mathematical model used is described; enabling preparation of this evaluation adapted and applied to a particular example facility namely a pool type research reactor. The factors influencing to the heat carrier movement by its own momentum are examined. The evaluation measures and includes the factors influencing the heat carrier flow rate from the moment the pump(s) stops down to a negligible value. Assessment is presented in detail, step by step and where needed with references to specific data and/or formulae from reference books to allow repetition of the calculations and/or apply to another facility. The calculations are presented utilizing all necessary data according to the design and technological documentation. No account is given to the pressure of the natural circulation caused by the residual heat generation in the fuel after the reactor scram system extinction of the fission reaction.

  6. Quality of Obturation Achieved by an Endodontic Core-carrier System with Crosslinked Gutta-percha Carrier in Single-rooted Canals

    Science.gov (United States)

    Li, Guo-hua; Niu, Li-na; Selem, Lisa C.; Eid, Ashraf A.; Bergeron, Brian E.; Chen, Ji-hua; Pashley, David H.; Tay, Franklin R.

    2014-01-01

    Objectives The present study examined the quality of obturation in root canals obturated by GuttaCore, a gutta-percha-based core-carrier system with a cross-linked thermoset gutta-percha carrier, by comparing the incidence of gaps and voids identified from similar canals obturated by cold lateral compaction or warm vertical compaction. Methods Thirty single-rooted premolars with oval-shaped canals were shaped and cleaned, and obturated with one of the three obturation techniques (N=10): GuttaCore, warm vertical compaction or cold lateral compaction. Filled canals were scanned with micro-computed tomography (micro-CT); reconstructed images were analysed for the volumetric percentage of gaps and voids at 3 canal levels (0-4 mm, 4-8 mm and 8-12 mm from working length). The roots were subsequently sectioned at the 4-mm, 8-mm and 12-mm levels for analyses of the percentage of interfacial gaps, and area percentage of interfacial and intracanal voids, using scanning electron microscopy (SEM) to examine negative replicas of root sections. Data were analysed with parametric or non-parametric statistical methods at α=0.05. Results Both micro-CT and SEM data indicated that canals obturated with GuttaCore core-carriers had the lowest incidence of interfacial gaps and voids, although the results were not significantly different from canals obturated by warm vertical compaction. Both the GuttaCore and the warm vertical compaction groups, in turn, had significantly lower incidences of gaps and voids than the cold lateral compaction group. Conclusions Because of the similarity in obturation quality between GuttaCore and warm vertical compaction, practitioners may find the GuttaCore core-carrier technique a valuable alternative for obturation of oval-shaped canals. PMID:24769108

  7. The novel approach to Cd(II) extraction by polymer inclusion membrane using TIOA as carrier

    Science.gov (United States)

    Polat, Cüneyt; Eyüpoǧlu, Volkan; Sara, Osman Nuri

    2016-04-01

    In the present study, the novel approach for the extraction of Cd(II) from acidic iodide solutions was achieved by using PVC based polymer inclusion membrane (PIM) technique containing triisooctyl amine (TIOA) as a carrier. PIMs were prepared according to the literature (1) and characterized by in aspects of thickness and surface morphology and molecular characterization. PIM composition was varied to find optimum membrane formation on Cd(II) transport. The effective parameters like thickness, plasticizer type and rate and carrier rate were investigated. Also, as a useful parameter, the concentration in the feed phase was examined to assess the effect on optimized membrane compositions. It was found that the concentration was the most useful parameter in the aqueous phase of Cd(II) transport because the remained I- in the aqueous feed phase unreacted with Cd(II). We recognize that by the time free I- concentration in the feed, the accumulation of the membrane increases and loading capacity of the membrane with CdI42- decreases because of the limited amount of carrier molecules in the PIM. As a result, it is concluded that extraction and separation of Cd(II) from simulated Ni/Cd leach solutions was carried out with higher initial mass transfer and permeation coefficients as 9,07×10-7 mol/m2s and 1,02×10-5 m/s at the optimum conditions respectively.

  8. Resonance vector mode locking

    CERN Document Server

    Kolpakov, Stanislav A; Loika, Yuri; Tarasov, Nikita; Kalashnikov, Vladimir; Agrawal, Govind P

    2015-01-01

    A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy...

  9. Measuring long-range carrier diffusion across multiple grains in polycrystalline semiconductors by photoluminescence imaging

    Science.gov (United States)

    Alberi, K.; Fluegel, B.; Moutinho, H.; Dhere, R. G.; Li, J. V.; Mascarenhas, A.

    2013-10-01

    Thin-film polycrystalline semiconductors are currently at the forefront of inexpensive large-area solar cell and integrated circuit technologies because of their reduced processing and substrate selection constraints. Understanding the extent to which structural and electronic defects influence carrier transport in these materials is critical to controlling the optoelectronic properties, yet many measurement techniques are only capable of indirectly probing their effects. Here we apply a novel photoluminescence imaging technique to directly observe the low temperature diffusion of photocarriers through and across defect states in polycrystalline CdTe thin films. Our measurements show that an inhomogeneous distribution of localized defect states mediates long-range hole transport across multiple grain boundaries to locations exceeding 10 μm from the point of photogeneration. These results provide new insight into the key role deep trap states have in low temperature carrier transport in polycrystalline CdTe by revealing their propensity to act as networks for hopping conduction.

  10. [Improvement of PVC bio-carrier surface property by remote plasma].

    Science.gov (United States)

    Li, Ru; Chen, Jie-Rong; Chen, Jun; Yao, Xin

    2006-01-01

    The effects of various remote plasma, such as Ar, He, O2 and N2 on PVC bio-carrier surface modification were studied. The surface properties were characterized by the contact angle measurement and X-ray photoelectron spectroscopy (XPS). The role of all kinds of active species such as electrons, ions and free radicals involved in plasma surface modification were evaluated. Results show that the remote plasma treatments modify the PVC surface in both wettability and composition, the (O + N)/C of PVC surface increases from 7% to 22%, and the water contact angle decreases from 97 degrees to 15 degrees. The optimal results was achieved when plasma treatment parameters were set, that is treatment time 3 min, Ar flux at 20 cm3/s, power at 60W, sample position of 40 cm. The results show that the modified PVC Bio-carrier adhesion rate and capacity on the modified surface are greatly increased.

  11. Carrier emission of n-type gallium nitride illuminated by femtosecond laser pulses

    Science.gov (United States)

    Li, Runze; Zhu, Pengfei; Chen, Jie; Cao, Jianming; Rentzepis, Peter M.; Zhang, Jie

    2016-12-01

    The carrier emission efficiency of light emitting diodes is of fundamental importance for many technological applications, including the performance of GaN and other semiconductor photocathodes. We have measured the evolution of the emitted carriers and the associated transient electric field after femtosecond laser excitation of n-type GaN single crystals. These processes were studied using sub-picosecond, ultrashort, electron pulses and explained by means of a "three-layer" analytical model. We find that for pump laser intensities on the order of 1011 W/cm2, the electrons that escaped from the crystal surface have a charge of ˜2.7 pC and a velocity of ˜1.8 μm/ps. The associated transient electrical field evolves at intervals ranging from picoseconds to nanoseconds. These results provide a dynamic perspective on the photoemission properties of semiconductor photocathodes.

  12. Measuring long-range carrier diffusion across multiple grains in polycrystalline semiconductors by photoluminescence imaging.

    Science.gov (United States)

    Alberi, K; Fluegel, B; Moutinho, H; Dhere, R G; Li, J V; Mascarenhas, A

    2013-01-01

    Thin-film polycrystalline semiconductors are currently at the forefront of inexpensive large-area solar cell and integrated circuit technologies because of their reduced processing and substrate selection constraints. Understanding the extent to which structural and electronic defects influence carrier transport in these materials is critical to controlling the optoelectronic properties, yet many measurement techniques are only capable of indirectly probing their effects. Here we apply a novel photoluminescence imaging technique to directly observe the low temperature diffusion of photocarriers through and across defect states in polycrystalline CdTe thin films. Our measurements show that an inhomogeneous distribution of localized defect states mediates long-range hole transport across multiple grain boundaries to locations exceeding 10 μm from the point of photogeneration. These results provide new insight into the key role deep trap states have in low temperature carrier transport in polycrystalline CdTe by revealing their propensity to act as networks for hopping conduction.

  13. Optical waveguide mode control by nanoslit-enhanced terahertz field

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Zalkovskij, Maksim; Malureanu, Radu

    2012-01-01

    In this Letter we propose a scheme providing control over an optical waveguide mode by a terahertz (THz) wave. The scheme is based on an optimization of the overlap between the optical waveguide mode and the THz field, with the THz field strength enhanced by the presence of a metallic nanoslit...... surrounding the waveguide. We find an optimum balance between the optical mode attenuation and Kerr-induced change in the propagation constant. The criterion for a π/2-cumulative phase shift, for instance for application in a Mach–Zehnder interferometer configuration, requires 10  kV/cm THz field, which...

  14. Cardiac pathologies in female carriers of Duchenne muscular dystrophy assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schelhorn, Juliane; Schemuth, Haemi; Nensa, Felix; Nassenstein, Kai; Forsting, Michael; Schlosser, Thomas [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schoenecker, Anne; Neudorf, Ulrich [University Hospital Essen, Department of Pediatric Cardiology, Essen (Germany); Schara, Ulrike [University Hospital Essen, Department of Pediatric Neurology, Essen (Germany)

    2015-10-15

    Duchenne muscular dystrophy (DMD) is the most common and severe dystrophinopathy. DMD carriers rarely present with clinical symptoms, but may suffer from cardiac involvement. Because echocardiographic findings are inconsistent and cardiac magnetic resonance imaging (CMRI) data are limited, this study sought to investigate asymptomatic carriers for cardiac abnormalities using CMRI. Fifteen genetically confirmed DMD carriers (age, 32.3 ± 10.2 years) were prospectively examined on a 1.5T MR system. Cine, T2, and late-gadolinium-enhanced (LGE) images were acquired, and were evaluated in consensus by two experienced readers. Left ventricular (LV) parameters were analysed semiautomatically, normalized to BSA. Normalized LV end-diastolic volume was increased in 7 % (73.7 ± 16.8 ml/m{sup 2}; range, 48-116 ml/m{sup 2}) and normalized LV end-systolic volume in 20 % (31.5 ± 13.3 ml/m{sup 2}; range, 15-74 ml/m{sup 2}). EF was reduced in 33 % (58.4 ± 7.6 %; range, 37-69 %) and normalized LV myocardial mass in 80 % (40.5 ± 6.8 g/m{sup 2}; range, 31-55 g/m{sup 2}). In 80 %, regional myocardial thinning was detected in more than one segment. In 13 % and 40 %, apical-lateral accentuation of LV non-compaction was present. LGE was found in 60 % (midmyocardial inferolateral accentuation). Given the high frequency of cardiac pathologies detected by CMRI, regular cardiac risk assessment is advisable for DMD carriers. Besides clinical examination, CMRI is an excellent tool for this purpose. (orig.)

  15. Comparative evaluation of actinide ion uptake by polymer inclusion membranes containing TODGA as the carrier extractant.

    Science.gov (United States)

    Mahanty, B N; Raut, D R; Mohapatra, P K; Das, D K; Behere, P G; Afzal, Md

    2014-06-30

    Polymer inclusion membranes (PIM) containing TODGA (N,N,N',N'-tetra-n-octyl diglycolamide) were evaluated for the separation of actinide ions such as Am(3+), Pu(4+), UO2(2+) and Th(4+) from acidic feeds. The PIMs were prepared using cellulose triacetate (CTA) as the polymer matrix and 2-nitrophenyloctyl ether (NPOE) as the plasticizer along with the diglycolamide carrier extractants and were characterized by conventional techniques such as XRD, thermal analysis and AFM. The PIM composition was optimized by a series of studies which involved variation in the CTA, NPOE and carrier concentration which suggested 58% TODGA, 30% NPOE and 12% CTA to be optimum. The uptake studies were carried out using feed solutions containing varying concentrations of nitric acid and showed the trend: Am(3+)>Pu(4+)>Th(4+)>UO2(2+). Transport studies were carried out in a two-compartment cell where nitric acid concentration the feed was varied (1-3M) while the receiver compartment contained alpha-hydroxy-iso-butyric acid (AHIBA). The actinide ion transport efficiencies with TODGA containing PIMs followed the same trend as seen in the uptake studies. The AFM patterns of the PIMs changed when loaded with Eu(3+) carrier (used as a surrogate for Am(3+)) while the regenerated membranes have displayed comparable morphologies. Diffusion coefficient values were experimentally obtained from the transport studies and were found to be 8.89×10(-8) cm(2)/s for Am(3+) transport.

  16. Production of Solid sustainable Energy Carriers from biomass by means of TORrefaction (SECTOR)

    Energy Technology Data Exchange (ETDEWEB)

    Witt, Janet; Bienert, Kathrin [DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH, Leipzig (Germany). Bereich Bioenergiesysteme; Zwart, Robin; Kiel, Jaap; Englisch, Martin; Wojcik, Magdalena

    2012-07-01

    SECTOR is a large-scale European project with a strong consortium of over 20 partners from industry and science. The project is focussed on the further development of torrefaction-based technologies for the production of solid bioenergy carriers up to pilot-plant scale and beyond, and on supporting the market introduction of torrefaction-based bioenergy carriers as a commodity renewable solid fuel. The torrefaction of biomass materials is considered to be a very promising technology for the promotion of the large-scale implementation of bioenergy. During torrefaction biomass is heated up in the absence of oxygen to a temperature of 250-320 C. By combining torrefaction with pelletisation or briquetting, biomass materials can be converted into a high-energy-density commodity solid fuel or bioenergy carrier with improved behaviour in (long-distance) transport, handling and storage, and also with superior properties in many major end-use applications. Torrefaction has the potential to provide a significant contribution to an enlarged raw material portfolio for biomass fuel production inside Europe by including both agricultural and forestry biomass. In this way, the SECTOR project is expected to shorten the time-to-market of torrefaction technology and to promote market introduction within stringent sustainability boundary conditions. The European Union provides funding for this project within the Seventh Framework Programme. The project has a duration of 42 months and started in January 2012. (orig.)

  17. Performance evaluation for PCC-OFDM systems impaired by carrier frequency offset over AWGN channels

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; ZHAO ChunMing; SHI ZhiHua; GONG XiaoQun

    2008-01-01

    Orthogonal frequency division multiplexing (OFDM) is sensitive to carrier fre- quency offset (CFO), which destroys the orthogonality and causes inter-carrier interference (ICI). ICI self-cancellation schemes based on polynomial cancellation coding (PCC-OFDM) can evidently reduce the sensitivity to CFO. In this paper, we analyze the performance of PCC-OFDM systems impaired by CFO over additive white gaussian noise (AWGN) channels. Two criteria are used to evaluate the effect of CFO on performance degradations. Firstly, the closed-form expressions of the average carrier-to-interference power ratio (CIR) and the statistical average ICI power, both of which reflect the desired power loss, are presented. Simulation and analytical results show that the theoretlcel expressions depend crucially on the normalized frequency offset and are hardly relevant to the number of subcarriers. Secondly, by exploiting the properties of the Beaulieu series, the effect of CFO on symbol error rate (SER) and bit error rate (BER) performance for PCC-OFDM sys- tems are exactly expressed as the sum of an infinite series in terms of the charac- teristic function (CHF) of ICI. We consider the systems modulated with binary phase shift keying (BPSK), quadrature PSK (QPSK), 8-ary PSK (8-PSK), and 16-ary quadrature amplitude modulation (16-QAM), and all above modulation schemes are mapped with Gray codes for the evaluations of BER.

  18. Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy

    KAUST Repository

    Sun, Jingya

    2014-06-11

    We explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.

  19. Visualization of carrier dynamics in p(n)-type GaAs by scanning ultrafast electron microscopy.

    Science.gov (United States)

    Cho, Jongweon; Hwang, Taek Yong; Zewail, Ahmed H

    2014-02-11

    Four-dimensional scanning ultrafast electron microscopy is used to investigate doping- and carrier-concentration-dependent ultrafast carrier dynamics of the in situ cleaved single-crystalline GaAs(110) substrates. We observed marked changes in the measured time-resolved secondary electrons depending on the induced alterations in the electronic structure. The enhancement of secondary electrons at positive times, when the electron pulse follows the optical pulse, is primarily due to an energy gain involving the photoexcited charge carriers that are transiently populated in the conduction band and further promoted by the electron pulse, consistent with a band structure that is dependent on chemical doping and carrier concentration. When electrons undergo sufficient energy loss on their journey to the surface, dark contrast becomes dominant in the image. At negative times, however, when the electron pulse precedes the optical pulse (electron impact), the dynamical behavior of carriers manifests itself in a dark contrast which indicates the suppression of secondary electrons upon the arrival of the optical pulse. In this case, the loss of energy of material's electrons is by collisions with the excited carriers. These results for carrier dynamics in GaAs(110) suggest strong carrier-carrier scatterings which are mirrored in the energy of material's secondary electrons during their migration to the surface. The approach presented here provides a fundamental understanding of materials probed by four-dimensional scanning ultrafast electron microscopy, and offers possibilities for use of this imaging technique in the study of ultrafast charge carrier dynamics in heterogeneously patterned micro- and nanostructured material surfaces and interfaces.

  20. Three modes of spatiotemporal preprocessing by eyes

    NARCIS (Netherlands)

    Hateren, J.H. van

    1993-01-01

    Optimal spatiotemporal filters for early vision were computed as a function of signal-to-noise ratio (SNR) and α, a parameter defined as the ratio of the width of the probability distribution of velocities as perceived by the naturally behaving animal, and the characteristic velocity of the photorec

  1. Mode-by-mode fluid dynamics for relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Floerchinger, Stefan, E-mail: stefan.floerchinger@cern.ch; Wiedemann, Urs Achim, E-mail: urs.wiedemann@cern.ch

    2014-01-20

    We propose to study the fluid dynamic propagation of fluctuations in relativistic heavy ion collisions differentially with respect to their azimuthal, radial and longitudinal wavelength. To this end, we introduce a background-fluctuation splitting and a Bessel–Fourier decomposition of the fluctuating modes. We demonstrate how the fluid dynamic evolution of realistic events can be built up from the propagation of individual modes. We describe the main elements of this mode-by-mode fluid dynamics, and we discuss its use in the fluid dynamic analysis of heavy ion collisions. As a first illustration, we quantify to what extent only fluctuations of sufficiently large radial wave length contribute to harmonic flow coefficients. We find that fluctuations of short wave length are suppressed not only due to larger dissipative effects, but also due to a geometrical averaging over the freeze-out hyper-surface. In this way, our study further substantiates the picture that harmonic flow coefficients give access to a coarse-grained version of the initial conditions for heavy ion collisions, only.

  2. Mode-by-mode fluid dynamics for relativistic heavy ion collisions

    Science.gov (United States)

    Floerchinger, Stefan; Wiedemann, Urs Achim

    2014-01-01

    We propose to study the fluid dynamic propagation of fluctuations in relativistic heavy ion collisions differentially with respect to their azimuthal, radial and longitudinal wavelength. To this end, we introduce a background-fluctuation splitting and a Bessel-Fourier decomposition of the fluctuating modes. We demonstrate how the fluid dynamic evolution of realistic events can be built up from the propagation of individual modes. We describe the main elements of this mode-by-mode fluid dynamics, and we discuss its use in the fluid dynamic analysis of heavy ion collisions. As a first illustration, we quantify to what extent only fluctuations of sufficiently large radial wave length contribute to harmonic flow coefficients. We find that fluctuations of short wave length are suppressed not only due to larger dissipative effects, but also due to a geometrical averaging over the freeze-out hyper-surface. In this way, our study further substantiates the picture that harmonic flow coefficients give access to a coarse-grained version of the initial conditions for heavy ion collisions, only.

  3. 78 FR 27137 - Verification of Statements of Account Submitted by Cable Operators and Satellite Carriers

    Science.gov (United States)

    2013-05-09

    ... Satellite Carriers AGENCY: U.S. Copyright Office, Library of Congress. ACTION: Notice of proposed rulemaking... to audit the Statements of Account and royalty fees that cable operators and satellite carriers... received from copyright owners, cable operators, and satellite carriers. The Copyright Office...

  4. 77 FR 60333 - Verification of Statements of Account Submitted by Cable Operators and Satellite Carriers

    Science.gov (United States)

    2012-10-03

    ... Satellite Carriers AGENCY: Copyright Office, Library of Congress. ACTION: Notice of proposed rulemaking... satellite carriers. DATES: Reply comments on the proposed rule published at 77 FR 35643, June 14, 2012, must... of Account and royalty fees that cable operators and satellite carriers deposit with the...

  5. Carrier-mediated release of monoamines induced by the nicotinic acetylcholine receptor agonist DMPP.

    Science.gov (United States)

    Szász, Bernadett K; Mayer, Aliz; Zsilla, Gabriella; Lendvai, Balázs; Vizi, E Sylvester; Kiss, János P

    2005-09-01

    We have previously shown that dimethylphenylpiperazinium (DMPP) increases the release of noradrenaline (NA) from rat hippocampal slices via two distinct mechanisms: a nicotinic acetylcholine receptor (nAChR)-mediated exocytosis and a carrier-mediated release induced by the reversal of NA transporters. Our aim was to investigate whether other monoaminergic systems are also affected by the multiple actions of DMPP. In our experiments DMPP dose-dependently increased the release of dopamine (DA) and serotonin (5-HT) from rat striatal and hippocampal slices, respectively. The dual effect was observed, however, only in case of DA at a lower DMPP concentration (30 microM), where the response was partly inhibited by mecamylamine, TTX and Ca2+-free medium (nAChR-mediated exocytosis) while the other part of the response was blocked only by the DA uptake inhibitor nomifensine (carrier-mediated release). In contrast, the DMPP-evoked 5-HT release and the DA release induced by high concentration DMPP was not inhibited by nicotinic antagonists, TTX and Ca2+-free medium but only by selective uptake inhibitors. In addition, DMPP dose-dependently inhibited the [3H]DA and [3H]5-HT uptake in striatal and hippocampal synaptosome preparation with an IC50 of 3.18 and 0.49 microM, respectively. Our data show that DMPP interacts with monoamine transporters and induces a substantial carrier-mediated release of DA and 5-HT, therefore caution is needed for the interpretation of data, when this drug is used as a nAChR agonist.

  6. Kinetic freeze-out, particle spectra and harmonic flow coefficients from mode-by-mode hydrodynamics

    CERN Document Server

    Floerchinger, Stefan

    2014-01-01

    The kinetic freeze-out for the hydrodynamical description of relativistic heavy ion collisions is discussed using a background-fluctuation splitting of the hydrodynamical fields. For a single event, the particle spectrum, or its logarithm, can be written as the sum of background part that is symmetric with respect to azimuthal rotations and longitudinal boosts and a part containing the contribution of fluctuations or deviations from the background. Using a complete orthonormal basis to characterize the initial state allows one to write the double differential harmonic flow coefficients determined by the two-particle correlation method as matrix expressions involving the initial fluid correlations. We discuss the use of these expressions for a mode-by-mode analysis of fluctuating initial conditions in heavy ion collisions.

  7. Analysis of carrier transport and carrier trapping in organic diodes with polyimide-6,13-Bis(triisopropylsilylethynyl)pentacene double-layer by charge modulation spectroscopy and optical second harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Eunju, E-mail: elim@dankook.ac.kr, E-mail: taguchi.d.aa@m.titech.ac.jp, E-mail: iwamoto@pe.titech.ac.jp [Department of Applied Physics, Institute of Nanosensor and Biotechnology, Dankook University, Jukjeon-dong, Gyeonggi-do 448-701 (Korea, Republic of); Taguchi, Dai, E-mail: elim@dankook.ac.kr, E-mail: taguchi.d.aa@m.titech.ac.jp, E-mail: iwamoto@pe.titech.ac.jp; Iwamoto, Mitsumasa, E-mail: elim@dankook.ac.kr, E-mail: taguchi.d.aa@m.titech.ac.jp, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2014-08-18

    We studied the carrier transport and carrier trapping in indium tin oxide/polyimide (PI)/6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene)/Au diodes by using charge modulation spectroscopy (CMS) and time-resolved electric field induced optical second harmonic generation (TR-EFISHG) measurements. TR-EFISHG directly probes the spatial carrier behaviors in the diodes, and CMS is useful in explaining the carrier motion with respect to energy. The results clearly indicate that the injected carriers move across TIPS-pentacene thorough the molecular energy states of TIPS-pentacene and accumulate at the PI/TIPS-pentacene interface. However, some carriers are trapped in the PI layers. These findings take into account the capacitance-voltage and current-voltage characteristics of the diodes.

  8. Organic double layer element driven by triboelectric nanogenerator: Study of carrier behavior by non-contact optical method

    Science.gov (United States)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-02-01

    By using optical electric-field-induced second-harmonic generation (EFISHG) technique, we studied carrier behavior caused by contact electrification (CE) in an organic double-layer element. This double-layer sample was half suspended in the open air, where one electrode (anode or cathode) was connected with a Cu foil for electrification while the other electrode was floated. Results showed two distinct carrier behaviors, depending on the (anode or cathode) connections to the Cu foil, and these carrier behaviors were analyzed based on the Maxwell-Wagner model. The double-layer sample works as a simple solar cell device. The photovoltaic effect and CE process have been proved to be two paralleled effects without strong interaction with each other, while photoconductivity changing in the sample can enhance the relaxation of CE induced charges. By probing the carrier behavior in this half-suspended device, the EFISHG technique has been demonstrated to be an effective non-contact method for clarifying the CE effect on related energy harvesting devices and electronics devices. Meanwhile, the related physical analysis in this letter is also useful for elucidating the fundamental characteristic of hybrid energy system based on solar cell and triboelectric nanogenerator.

  9. Microwave oscillator with reduced phase noise by negative feedback incorporating microwave signals with suppressed carrier

    Science.gov (United States)

    Dick, G. J.; Saunders, J.

    1989-01-01

    Oscillator configurations which reduce the effect of 1/f noise sources for both direct feedback and stabilized local oscillator (STALO) circuits are developed and analyzed. By appropriate use of carrier suppression, a small signal is generated which suffers no loss of loop phase information or signal-to-noise ratio. This small signal can be amplified without degradation by multiplicative amplifier noise, and can be detected without saturation of the detector. Together with recent advances in microwave resonator Qs, these circuit improvements will make possible lower phase noise than can be presently achieved without the use of cryogenic devices.

  10. Ultrafast carrier dynamics and the role of grain boundaries in polycrystalline silicon thin films grown by molecular beam epitaxy

    Science.gov (United States)

    Titova, Lyubov V.; Cocker, Tyler L.; Xu, Sijia; Baribeau, Jean-Marc; Wu, Xiaohua; Lockwood, David J.; Hegmann, Frank A.

    2016-10-01

    We have used time-resolved terahertz spectroscopy to study microscopic photoconductivity and ultrafast photoexcited carrier dynamics in thin, pure, non-hydrogenated silicon films grown by molecular beam epitaxy on quartz substrates at temperatures ranging from 335 °C to 572 °C. By controlling the growth temperature, thin silicon films ranging from completely amorphous to polycrystalline with minimal amorphous phase can be achieved. Film morphology, in turn, determines its photoconductive properties: in the amorphous phase, carriers are trapped in bandtail states on sub-picosecond time scales, while the carriers excited in crystalline grains remain free for tens of picoseconds. We also find that in polycrystalline silicon the photoexcited carrier mobility is carrier-density-dependent, with higher carrier densities mitigating the effects of grain boundaries on inter-grain transport. In a film grown at the highest temperature of 572 °C, the morphology changes along the growth direction from polycrystalline with needles of single crystals in the bulk of the film to small crystallites interspersed with amorphous silicon at the top of the film. Depth profiling using different excitation wavelengths shows corresponding differences in the photoconductivity: the photoexcited carrier lifetime and mobility are higher in the first 100-150 nm from the substrate, suggesting that thinner, low-temperature grown polycrystalline silicon films are preferable for photovoltaic applications.

  11. Estimation of free carrier concentrations in high-quality heavily doped GaN:Si micro-rods by photoluminescence and Raman spectroscopy

    Science.gov (United States)

    Mohajerani, M. S.; Khachadorian, S.; Nenstiel, C.; Schimpke, T.; Avramescu, A.; Strassburg, M.; Hoffmann, A.; Waag, A.

    2016-03-01

    The controlled growth of highly n-doped GaN micro rods is one of the major challenges in the fabrication of recently developed three-dimensional (3D) core-shell light emitting diodes (LEDs). In such structures with a large active area, higher electrical conductivity is needed to achieve higher current density. In this contribution, we introduce high quality heavily-doped GaN:Si micro-rods which are key elements of the newly developed 3D core-shell LEDs. These structures were grown by metal-organic vapor phase epitaxy (MOVPE) using selective area growth (SAG). We employed spatially resolved micro-Raman and micro-photoluminescence (PL) in order to directly determine a free-carrier concentration profile in individual GaN micro-rods. By Raman spectroscopy, we analyze the low-frequency branch of the longitudinal optical (LO)-phonon-plasmon coupled modes and estimate free carrier concentrations from ≍ 2.4 × 1019 cm-3 up to ≍ 1.5 × 1020 cm-3. Furthermore, free carrier concentrations are determined by estimating Fermi energy level from the near band edge emission measured by low-temperature PL. The results from both methods reveal a good consistency.

  12. Reassessment of the carrier concentration in GeTe-based thermoelectric materials by ^125Te NMR

    Science.gov (United States)

    Levin, E. M.; Acton, J. D.; Schmidt-Rohr, K.

    2012-02-01

    Ge1-xAgx/2Sbx/2Te p-type thermoelectric materials (``TAGS-n'') were studied extensively in the 1970s and then again recently. They exhibit an unusual combination of large thermopower, S, and high hole concentration, p, reported based on the Hall effect data, which has not been explained. To solve this puzzle, we have synthesized GeTe, GeTe:Bi, and TAGS-n with n = 97, 94, 90, and 85 and studied XRD, thermopower, electrical resistivity, thermal conductivity, and ^125Te NMR. Most importantly, we have determined the carrier concentrations using ^125Te NMR spin-lattice relaxation and Knight shift. In GeTe and GeTe:Bi, we found that carrier concentrations generally agree with the values reported from Hall effect. In TAGS-n, they are much lower but agree better with the values expected from S vs. p for GeTe-based materials, solving the puzzle partially. The NMR vs. Hall effect discrepancy in TAGS-n can be due to the presence not only of holes but also electrons generated by Sb atoms, which results in artificially high hole concentration from Hall effect. Even though the true hole concentration is lower than reported, the thermopower of TAGS-n is still significantly larger than that of GeTe and GeTe:Bi at similar carrier concentration. This can be explained by energy filtering enhanced by potential barriers formed due to Ag-Sb pairs in the TAGS-n lattice.

  13. An atomic switch of electron propagation on Ge (001) by tunneling carrier injection

    Science.gov (United States)

    Komori, Fumio

    2008-03-01

    Reversible switching of electronic conduction through atom manipulation is one of the important subjects of nanoscience. However, different conducting pathways were not clearly observed with atomic resolution. We have demonstrated the correlation between the change of surface atomic position by tunneling carrier injection and that of the reflection of one-dimensional (1D) surface-state electrons on the Ge (001) surface with a low density of heterogeneous Sn-Ge dimers. [1] On the clean Ge(001) surface, two adjacent atoms form a buckled dimer, and the buckling orientation of the Ge dimer can be locally and reversibly controlled by carrier injection to the surface from the STM tip. [2] The unoccupied surface &*circ;-electron behaves like a 1D free electron along the Ge dimer row. When Sn atoms are deposited on the clean Ge(001) surface at room temperature, buckled dimers originating from the Sn atoms are formed at the Ge dimer position in the surface. [3] An atomic switch is realized for the &*circ; electrons in the Ge dimer- row direction by injection carriers to reversibly flip the buckling orientation of a single Sn-Ge dimer in the dimer row. When the Sn atom of the heterogeneous dimer is at the lower position, the 1D electrons are reflected and a standing wave of this state is observed. Whereas, when it is at the upper position, the 1D electrons pass through the heterogeneous dimer, and no standing wave is observed. In this state, the lower atom of the dimer is Ge, and the &*circ; state at the dimer is little different from that of the Ge-Ge dimers. [1] K. Tomatsu, K. Nakatsuji, T. Iimori, Y. Takagi, H. Kusuhara, A. Ishii, F. Komori; Science 315, 1696, 2007. [2] Y. Takagi, Y. Yoshimoto, K. Nakatsuji, F. Komori; Surf. Sci. 559, 1, 2004. [3] K. Tomatsu, K. Nakatsuji, T. Iimori, F. Komori; Surf. Sci. 601, 1736, 2007.

  14. Carrier Transfer between InGaAs/GaAs Quantum Wells Separated by Thick Barriers

    DEFF Research Database (Denmark)

    Borri, Paola; Gurioli, M.; Colocci, M.;

    1997-01-01

    We have studied the carrier transfer between two adjacent wells of different width separated by a 100 nm thick barrier. At low temperatures (T transfer has very little dependence (if any) on T. For T > 30 K: the transfer strongly increases, denoting that the thermal escape out of the QW...... becomes the main mechanism. Finally, a drastic quenching of the transfer is found for temperatures higher than 50 to 70 K, suggesting the activation of a further non-radiative channel different from the thermal escape....

  15. Towards high charge carrier mobilities by rational design of organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Andrienko, Denis; Ruehle, Victor; Baumeier, Bjoern; Vehoff, Thorsten; Lukyanov, Alexander; Kremer, Kurt [Max Planck Institute for Polymer Research, Mainz (Germany); Marcon, Valentina [Technische Universitaet Darmstadt (Germany); Kirkpatrick, James; Nelson, Jenny [Imperial College London (United Kingdom); Lennartz, Christian [BASF AG, Ludwigshafen (Germany)

    2010-07-01

    The role of material morphology on charge carrier mobility in partially disordered organic semiconductors is discussed for several classes of materials: derivatives of hexabenzocoronenens, perylenediimides, triangularly-shaped polyaromatic hydrocarbons, and Alq{sub 3}. Simulations are performed using a package developed by Imperial College, London and Max Planck Institute for Polymer Research, Mainz (votca.org). This package combines several techniques into one scheme: quantum chemical methods for the calculation of molecular electronic structures and reorganization energies; molecular dynamics and systematic coarse-graining approaches for simulation of self-assembly and relative positions and orientations of molecules on large scales; kinetic Monte Carlo and master equation for studies of charge transport.

  16. Minority carrier lifetimes in different doped LWIR HgCdTe grown by LPE

    Science.gov (United States)

    Qiu, GuangYin; Wei, YanFeng; Sun, QuanZhi; Yang, JianRong

    2012-10-01

    The carrier lifetimes of different types of p-type doped HgCdTe(x~0.23) long wavelength infrared (LWIR) epilayers were measured which were Hg-vacancy, Au and arsenic doped ones prepared by Te-rich Liquid-phase epitaxy (LPE). By comparing the lifetimes of Hg-vacancy and extrinsic doped HgCdTe, we focus on three primary mechanisms limiting the lifetimes in these different p-type HgCdTe samples: radiative recombination, Auger recombination and Schokley-Read- Hall (SRH) Recombination. The recombination mechanism in p-type HgCdTe is the SRH recombination at low temperatures and Auger and radiative recombination at high temperature. It is found that the lifetime of As-doped and Au-doped HgCdTe is far longer than that of Hg-vacancy-doped sample which is caused by the deep energy level of the Hg-vacancy acceptor that is considered as a recombination center in HgCdTe. Also we found lifetime in those p-type doped HgCdTe LWIR epilayers is limited by SRH by comparing the experimental lifetimes with the calculated data. Impurity doping was found to have a main effect on minority carrier lifetime.

  17. Charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene): Effects of carrier bimolecular recombination and trapping

    Science.gov (United States)

    Soci, Cesare; Moses, Daniel; Xu, Qing-Hua; Heeger, Alan J.

    2005-12-01

    We have studied the charge-carrier relaxation dynamics in highly ordered poly( p -phenylene vinylene) over a broad time range using fast (t>100ps) transient photoconductivity measurements. The carrier density was also monitored (t>100fs) by means of photoinduced absorption probed at the infrared active vibrational modes. We find that promptly upon charge-carrier photogeneration, the initial polaron dynamics is governed by bimolecular recombination, while later in the subnanosecond time regime carrier trapping gives rise to an exponential decay of the photocurrent. The more sensitive transient photocurrent measurements indicate that in the low excitation regime, when the density of photocarriers is comparable to that of the trapping states (˜1016cm-3) , carrier hopping between traps along with transport via extended states determines the carrier relaxation, a mechanism that is manifested by a long-lived photocurrent “tail.” This photocurrent tail is reduced by lowering the temperature and/or by increasing the excitation density. Based on these data, we develop a comprehensive kinetic model that takes into account the bipolar charge transport, the free-carrier bimolecular recombination, the carrier trapping, and the carrier recombination involving free and trapped carriers.

  18. Single-Mode WGM Resonators Fabricated by Diamond Turning

    Science.gov (United States)

    Grudinin, Ivan; Maleki, Lute; Savchenkov, Anatoliy; Matsko, Andrewy; Strekalov, Dmitry; Iltchenko, Vladimir

    2008-01-01

    A diamond turning process has made possible a significant advance in the art of whispering-gallery-mode (WGM) optical resonators. By use of this process, it is possible to fashion crystalline materials into WGM resonators that have ultrahigh resonance quality factors (high Q values), are compact (ranging in size from millimeters down to tens of microns), and support single electromagnetic modes. This development combines and extends the developments reported in "Few- Mode Whispering-Gallery-Mode Resonators" (NPO-41256), NASA Tech Briefs, Vol. 30, No. 1 (January 2006), page 16a and "Fabrication of Submillimeter Axisymmetric Optical Components" (NPO-42056), NASA Tech Briefs, Vol. 31, No. 5 (May 2007), page 10a. To recapitulate from the first cited prior article: A WGM resonator of this special type consists of a rod, made of a suitable transparent material, from which protrudes a thin circumferential belt of the same material. The belt is integral with the rest of the rod and acts as a circumferential waveguide. If the depth and width of the belt are made appropriately small, then the belt acts as though it were the core of a single-mode optical fiber: the belt and the rod material adjacent to it support a single, circumferentially propagating mode or family of modes. To recapitulate from the second cited prior article: A major step in the fabrication of a WGM resonator of this special type is diamond turning or computer numerically controlled machining of a rod of a suitable transparent crystalline material on an ultrahigh-precision lathe. During the rotation of a spindle in which the rod is mounted, a diamond tool is used to cut the rod. A computer program is used to control stepping motors that move the diamond tool, thereby controlling the shape cut by the tool. Because the shape can be controlled via software, it is possible to choose a shape designed to optimize a resonator spectrum, including, if desired, to limit the resonator to supporting a single mode

  19. Electron acceleration by Landau resonance with whistler mode wave packets

    Science.gov (United States)

    Gurnett, D. A.; Reinleitner, L. A.

    1983-01-01

    Recent observations of electrostatic waves associated with whistler mode chorus emissions provide evidence that electrons are being trapped by Landau resonance interactions with the chorus. In this paper, the trapping, acceleration and escape of electrons in Landau resonance with a whistler mode wave packet are discussed. It is shown that acceleration can occur by both inhomogeneous and dispersive effects. The maximum energy gained is controlled by the points where trapping and escape occur. Large energy changes are possible if the frequency of the wave packet or the magnetic field strength increase between the trapping and escape points. Various trapping and escape mechanisms are discussed.

  20. Photoinduced Transformation between Charge Carrier and Spin Carrier in Polymers

    Institute of Scientific and Technical Information of China (English)

    MEI Yuan; ZHAO Chang; SUN Xin

    2006-01-01

    By dynamical simulations, we show a transforming process between neutral soliton (spin carrier) and charged soliton (charge carrier) in polymers via photo-excitation, taking a polaron as the transitional bridge. It is photoinduced transformation between spin carrier and charge carrier. In this way, we demonstrate an access for polymers to be applied to spintronics.

  1. Optical Mode Control by Geometric Phase in Quasicrystal Metasurface

    CERN Document Server

    Yulevich, Igor; Shitrit, Nir; Veksler, Dekel; Kleiner, Vladimir; Hasman, Erez

    2015-01-01

    We report on the observation of optical spin-controlled modes from a quasicrystalline metasurface as a result of an aperiodic geometric phase induced by anisotropic subwavelength structure. When geometric phase defects are introduced in the aperiodic structured surface, the modes exhibit polarization helicity dependence resulting in the optical spin-Hall effect. The radiative thermal dispersion bands from a quasicrystal structure were studied where the observed bands arise from the optical spin-orbit interaction induced by the aperiodic space-variant orientations of anisotropic antennas. The optical spin-flip behavior of the revealed modes that arise from the geometric phase pickup was experimentally observed within the visible spectrum by measuring the spin-projected diffraction patterns. The introduced ability to manipulate the light-matter interaction of quasicrystals in a spin-dependent manner provides the route for molding light via spin-optical aperiodic artificial planar surfaces.

  2. Nutrient capture and recycling by periphyton attached to modified agrowaste carriers.

    Science.gov (United States)

    Wan, Juanjuan; Liu, Xuemei; Wu, Chenxi; Wu, Yonghong

    2016-04-01

    The reuse of periphytic biofilm from traditional wastewater treatment (i.e., active sludge process) is inefficient to recycle nutrients due to low accumulation of nutrients. Then, in this study, peanut shell (PS), rice husk (RH), decomposed peanut shell (DPS), acidified rice husks (ARH), and a commonly used carrier-ceramsite (C, as the control)-were used to support the growth of periphyton. Results showed that DPS and ARH supported significantly higher periphyton biomass and metabolic versatility than PS and RH, respectively, due to the increased presence of positive groups. The total nitrogen (TN) and total phosphorus (TP) captured by periphyton were enhanced by 600-657 and 833-3255 % for DPS, and 461-1808 and 21-308 % for ARH, respectively. The removal of nutrients from simulated eutrophic surface waters using periphyton attached to DPS was improved by 24-47 % for TP, 12-048 % for TN, and 15-78 % for nitrate compared to the control. The results indicate that the periphyton attached to modified agrowaste was capable of efficiently entrapping and storing N and P from eutrophic water. This study also implies that the mixture of periphyton and the modified agrowaste carriers are promising raw materials of biofertilizer.

  3. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; de Knegt, Martina Chantal;

    2016-01-01

    PURPOSE: To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining...... MPI (MPIConv), with established echocardiographic and invasive measures of systolic and diastolic function. METHODS: In a large community based population study (n = 974), where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic...... the MPITDI and MPIConv measured. RESULTS: IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (pcardiac function. MPITDI...

  4. Mean flow generation mechanism by inertial waves and normal modes

    Science.gov (United States)

    Will, Andreas; Ghasemi, Abouzar

    2016-04-01

    The mean flow generation mechanism by nonlinearity of the inertial normal modes and inertial wave beams in a rotating annular cavity with longitudinally librating walls in stable regime is discussed. Inertial normal modes (standing waves) are excited when libration frequency matches eigenfrequencies of the system. Inertial wave beams are produced by Ekman pumping and suction in a rotating cylinder and form periodic orbits or periodic ray trajectories at selected frequencies. Inertial wave beams emerge as concentrated shear layers in a librating annular cavity, while normal modes appear as global recirculation cells. Both (inertial wave beam and mode) are helical and thus intrinsically non-linear flow structures. No second mode or wave is necessary for non-linearity. We considered the low order normal modes (1,1), (2,1) and (2,2) which are expected to be excited in the planetary objects and investigate the mean flow generation mechanism using two independent solutions: 1) analytical solution (Borcia 2012) and 2) the wave component of the flow (ω0 component) obtained from the direct numerical simulation (DNS). It is well known that a retrograde bulk mean flow is generated by the Ekman boundary layer and E1/4-Stewartson layer close to the outer cylinder side wall due to libration. At and around the normal mode resonant frequencies we found additionally a prograde azimuthal mean flow (Inertial Normal Mode Mean Flow: INMMF) in the bulk of the fluid. The fluid in the bulk is in geostrophic balance in the absence of the inertial normal modes. However, when INMMF is excited, we found that the geostrophic balance does not hold in the region occupied by INMMF. We hypothesize that INMMF is generated by the nonlinearity of the normal modes or by second order effects. Expanding the velocity {V}(u_r,u_θ,u_z) and pressure (p) in a power series in ɛ (libration amplitude), the Navier-Stokes equations are segregated into the linear and nonlinear parts at orders ɛ1 and ɛ^2

  5. The value of energy carriers

    NARCIS (Netherlands)

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often r

  6. MHD MODES DESTABILIZED BY ENERGETIC IONS ON LHD

    Energy Technology Data Exchange (ETDEWEB)

    Toi, K. [National Institute for Fusion Science, Toki, Japan; Isobe, M. [National Institute for Fusion Science, Toki, Japan; Spong, Donald A [ORNL

    2010-01-01

    nergetic ion driven magnetohydrodynamic instabilities such as Alfven eigenmodes (AEs), energetic particle modes (EPMs), and their impacts on energetic ion confinement are being studied on the Large Helical Device (LHD). The magnetic configuration of this device is three dimensional and has negative magnetic shear over a whole radial region in the low-beta regime. Two types of toroidicity-induced Alfven eigenmodes (TAEs) are typically observed in LHD plasmas that are heated by tangential neutral beam injection: One is localized in the plasma core region near a central TAE gap and the other is a global TAE having a radially extended eigenfunction. Core-localized TAEs with even and odd radial mode parities are often observed. The global TAE is usually observed in medium- to high-beta plasmas where broad regions with low magnetic shear are present. Helicity-induced Alfven eigenmodes (HAEs), which exist in gaps unique to three-dimensional plasmas that have both toroidal and poloidal mode couplings, were detected for the first time. Recently, reversed magnetic shear Alfven eigenmodes (RSAEs) having characteristic frequency sweeping were discovered in reversed magnetic shear (RS) plasmas produced by intense counter-neutral beam current drive. In the RS plasma, the geodesic acoustic mode (GAM) excited by energetic ions, which is a global-type mode different from localized GAM excited by drift waves, was also detected for the first time in a helical plasma. Nonlinear couplings between RSAE and GAM modes and also between two TAEs were observed. Bursts of TAEs and EPMs often enhance radial transport and loss of energetic ions at low toroidal magnetic field (<0.75 T).

  7. AXISYMMETRIC SCATTERING OF p MODES BY THIN MAGNETIC TUBES

    Energy Technology Data Exchange (ETDEWEB)

    Hindman, Bradley W. [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309-0440 (United States); Jain, Rekha, E-mail: hindman@solarz.colorado.edu [Applied Mathematics Department, University of Sheffield, Sheffield S3 7RH (United Kingdom)

    2012-02-10

    We examine the scattering of acoustic p-mode waves from a thin magnetic fibril embedded in a gravitationally stratified atmosphere. The scattering is mediated through the excitation of slow sausage waves on the magnetic tube, and only the scattering of the monopole component of the wave field is considered. Since such tube waves are not confined by the acoustic cavity and may freely propagate along the field lines removing energy from the acoustic wave field, the excitation of fibril oscillations is a source of acoustic wave absorption as well as scattering. We compute the mode mixing that is achieved and the absorption coefficients and phase shifts. We find that for thin tubes the mode mixing is weak and the absorption coefficient is small and is a smooth function of frequency over the physically relevant band of observed frequencies. The prominent absorption resonances seen in previous studies of unstratified tubes are absent. Despite the relatively small absorption, the phase shift induced can be surprisingly large, reaching values as high as 15 Degree-Sign for f modes. Further, the phase shift can be positive or negative depending on the incident mode order and the frequency.

  8. Stratospheric Annular Modes Induced By Stationary Wave Forcing

    Science.gov (United States)

    Körnich, H.; Schmitz, G.

    The variability of the winter stratosphere shows distinguishable features in the north- ern and southern hemisphere. Since these differences are based on the different plan- etary waves of the underlying atmosphere, we explore the mechanism how stationary wave forcing in the troposphere can induce a stratospheric Annular Mode using a simple GCM. The model KMCM (Kühlungsborn Mechanistic Circulation Model) extends from the ground up to 60 km height and produces a reasonable winter climate. It takes into account the different large-scale wave forcings in the troposphere as prescribed pro- cesses. This allows us to examine the stratospheric Annular-Mode generation depend- ing on different wave forcings under perpetual January conditions. Principal com- ponent analysis is applied to identify the variability patterns of the geopotential and of the zonally averaged zonal wind. By this way, it is shown that the amplitude and composition of the orographic and thermal eddy forcing determines the stratospheric Annular Mode and the related downward propagation in the temperature field. Further model simplifications are introduced in order to understand the mechanism of the stratospheric AM-generation. Using a linear model version we illuminate the influence of the different wave forcing processes on the Annular Modes. Addition- ally, a constant-troposphere model is used to clarify the importance of transient and stationary waves. Finally, the Annular Mode is interpreted in terms of the dynamical coupling of the troposphere and stratosphere.

  9. Enhanced bioremediation of PAH-contaminated soil by immobilized bacteria with plant residue and biochar as carriers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baoliang; Yuan, Miaoxin; Qian, Linbo [Zhejiang Univ., Hangzhou (China). Dept. of Environmental Science; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou (China)

    2012-10-15

    Polycyclic aromatic hydrocarbons (PAHs) are largely accumulated in soils in China. The immobilized-microorganism technique (IMT) is a potential approach for abating soil contamination with PAHs. However, few studies about the application of IMT to contaminated soil remediation were reported. Due to recalcitrance to decomposition, biochar application to soil may enhance soil carbon sequestration, but few studies on the application of biochars to remediation of contaminated soil were reported. In this study, we illustrated enhanced bioremediation of soil having a long history of PAH contamination by IMT using plant residues and biochars as carriers. Two PAH-degrading bacteria, Pseudomonas putida and an unidentified indigenous bacterium, were selected for IMT. The extractability and biodegradation of 15 PAHs in solution and an actual PAH-contaminated soil amended with immobilized-bacteria materials were investigated under different incubation periods. The effects of carriers and the molecular weight of PAHs on bioremediation efficiency were determined to illustrate their different bio-dissipation mechanisms of PAHs in soil. The IMT can considerably enhance the removal of PAHs. Carriers impose different effects on PAH bio-dissipation by amended soil with immobilized-bacteria, which can directly degrade the carrier-associated PAHs. The removal of PAHs from soil depended on PAH molecular weight and carrier types. Enhanced bio-dissipation by IMT was much stronger for 4- and 5-ring PAHs than for 3- and 6-ring ones in soil. Only P400 biochar-immobilized bacteria enhanced bio-dissipation of all PAHs in contaminated soil after a 90-day incubation. Biochar can promote bioremediation of contaminated soil as microbial carriers of IMT. It is vital to select an appropriate biochar as an immobilized carrier to stimulate biodegradation. It is feasible to use adsorption carriers with high sorptive capabilities to concentrate PAHs as well as microorganisms and thereby enhance

  10. Two-mode clustering of genotype by trait and genotype by environment data

    NARCIS (Netherlands)

    Hageman, J.A.; Malosetti, M.; Eeuwijk, van F.A.

    2012-01-01

    In this paper, we demonstrate the use of two-mode clustering for genotype by trait and genotype by environment data. In contrast to two separate (one mode) clusterings on genotypes or traits/environments, two-mode clustering simultaneously produces homogeneous groups of genotypes and traits/environm

  11. Information report presented in application of article 145 of the regulation by the commission of national defense and armed forces about the propulsion system of the second aircraft carrier; Rapport d'information depose en application de l'article 145 du reglement par la commission de la defense nationale et des forces armees sur le mode de propulsion du second porte-avions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-11-01

    In the framework of the project of launching of a sister-ship to the Charles de Gaulle aircraft carrier, this report makes an objective analysis of the different possible propulsion systems that can be considered for this battle ship according to different criteria: 1 - two possible energy sources and four possible configurations of aircraft carrier considered: alternative between nuclear propulsion and conventional propulsion, the two nuclear ships eventualities, the hypothesis of an entirely French-made classical propulsion ship, the opportunity of a French-British cooperation for a conventional aircraft carrier project; 2 - decision criteria: operational need, cost, industrial and technological stakes, constraints linked with daily ship and crew life; 3 - propulsion systems alternative: conventional propulsion and reinforcement of the European defense policy, nuclear propulsion for an operational superiority and for a complementarity with the Charles de Gaulle. (J.S.)

  12. Kinetic energy dependence of carrier diffusion in a GaAs epilayer studied by wavelength selective PL imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.; Su, L. Q.; Kon, J.; Gfroerer, T.; Wanlass, M. W.; Zhang, Y.

    2017-05-01

    Photoluminescence (PL) imaging has been shown to be an efficient technique for investigating carrier diffusion in semiconductors. In the past, the measurement was typically carried out by measuring at one wavelength (e.g., at the band gap) or simply the whole emission band. At room temperature in a semiconductor like GaAs, the band-to-band PL emission may occur in a spectral range over 200 meV, vastly exceeding the average thermal energy of about 26 meV. To investigate the potential dependence of the carrier diffusion on the carrier kinetic energy, we performed wavelength selective PL imaging on a GaAs double hetero-structure in a spectral range from about 70 meV above to 50 meV below the bandgap, extracting the carrier diffusion lengths at different PL wavelengths by fitting the imaging data to a theoretical model. The results clearly show that the locally generated carriers of different kinetic energies mostly diffuse together, maintaining the same thermal distribution throughout the diffusion process. Potential effects related to carrier density, self-absorption, lateral wave-guiding, and local heating are also discussed.

  13. ANALYSIS OF MONOPOLE ANTENNA ON CIRCULAR DISC BY MODE MATCHING

    Institute of Scientific and Technical Information of China (English)

    Sun Baohua; Zhang Fushun; Liu Qizhong

    2001-01-01

    Mode matching is used for the analysis of monopole antenna on circular disc, which is achieved by developing a novel model consisting of two artificial ground planes above and bellow the monopole antenna. Using this model, the input impedance is computed and compared with measured data reported in literatures, and excellent agreement is observed.

  14. Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Orban, David E; Moretti, Alysha; Uhrich, Kathryn E

    2016-07-01

    A combination of nuclear magnetic resonance (NMR) techniques including, proton NMR, relaxation analysis, two-dimensional nuclear Overhauser effect spectroscopy, and diffusion-ordered spectroscopy, has been used to demonstrate the spatial location of indomethacin within a unimolecular micelle. Understanding the location of drugs within carrier molecules using such NMR techniques can facilitate rational carrier design. In addition, this information provides insight to encapsulation efficiency of different drugs to determine the most efficient system for a particular bioactive. This study demonstrates that drugs loaded by the unimolecular amphiphile under investigation are not necessarily encapsulated but reside or localize to the periphery or interfacial region of the carrier molecule. The results have further implications as to the features of the unimolecular carrier that contribute to drug loading. In addition, evidence of drug retention associated with the unimolecular surfactant is possible in organic media, as well as in an aqueous environment. Such findings have implications for rational carrier design to correlate the carrier features to the drug of interest and indicate the strong retention capabilities of the unimolecular micelle for delivery applications. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Improvement of dissolution and hypoglycemic efficacy of glimepiride by different carriers.

    Science.gov (United States)

    Mohamed, Elham A; Meshali, Mahasen M; Foda, Abdel Monem M; Borg, Thanaa M

    2012-09-01

    Effects of tromethamine (Tris), polyvinylpyrrolidone (PVP-K25), and low molecular weight chitosan (LM-CH) on dissolution and therapeutic efficacy of glimepiride (Gmp) were investigated using physical mixtures (PMs), coground mixtures, coprecipitates (Coppts) or kneaded mixtures (KMs), and compared with drug alone. Fourier transform infrared spectroscopy, differential scanning colorimetry, and X-ray diffractometry were performed to identify any physicochemical interaction with Gmp. Surface morphology was examined via scanning electron microscopy. The results of Gmp in vitro dissolution revealed that it was greatly enhanced by Coppt with Tris or PVP-K25 and KM with LM-CH at a drug to carrier ratio of 1:8. Gmp amorphization by PVP-K25 and LM-CH was a major factor in increasing Gmp dissolution. Being basic, Tris might increase the pH of the microdiffusion layer around Gmp particles improving its dissolution. Formation of water-soluble complexes suggested by solubility study may also explain the enhanced dissolution. Capsules were prepared from Coppts and KM 1:8 drug to carrier binary systems and also with Tris PMs. In vivo, the hypoglycemic efficacy of Gmp capsules in rabbits increased by 1.63-, 1.50-, and 1.46-fold for 1:8 Coppts with Tris or PVP-K25 and KM with LM-CH respectively, compared with Gmp alone. Surprisingly, the response to Tris PM 1:20 capsules was 1.52-fold revealing statistically insignificant difference to that of Tris Coppt 1:8 (1.63 fold). As a conclusion, dissolution enhancement and hypoglycemic potentiation by 1:20 PM of Gmp/Tris, being simple and easy to prepare, may enable development of a reduced-dose and fast-release oral dosage form of Gmp.

  16. 78 FR 78257 - Verification of Statements of Account Submitted by Cable Operators and Satellite Carriers

    Science.gov (United States)

    2013-12-26

    ... Satellite Carriers AGENCY: U.S. Copyright Office, Library of Congress. ACTION: Interim rule. SUMMARY: The U... Satellite Television Extension and Localism Act of 2010 (``STELA''). Cable operators and satellite carriers... regulations to allow copyright owners to audit the SOAs and royalty fees that cable operators and...

  17. Reduced folate carrier polymorphism determines methotrexate uptake by B cells and CD4+ T cells

    DEFF Research Database (Denmark)

    Baslund, B; Gregers, J; Nielsen, Claus Henrik

    2008-01-01

    To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells.......To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells....

  18. Alginate microspheres obtained by the spray drying technique as mucoadhesive carriers of ranitidine

    Directory of Open Access Journals (Sweden)

    Szekalska Marta

    2015-03-01

    Full Text Available The present study is aimed at formulation of alginate (ALG microspheres with ranitidine (RNT by the spray drying method. Obtained microspheres were characterized for particle size, surface morphology, entrapment efficiency, drug loading, in vitro drug release and zeta potential. Mucoadhesive properties were examined by a texture analyser and three types of adhesive layers - gelatine discs, mucin gel and porcine stomach mucosa. Microspheres showed a smooth surface with narrow particle size distribution and RNT loading of up to 70.9 %. All formulations possessed mucoadhesive properties and exhibited prolonged drug release according to the first-order kinetics. DSC reports showed that there was no interaction between RNT and ALG. Designed microspheres can be considered potential carriers of ranitidine with prolonged residence time in the stomach

  19. Alginate microspheres obtained by the spray drying technique as mucoadhesive carriers of ranitidine.

    Science.gov (United States)

    Szekalska, Marta; Amelian, Aleksandra; Winnicka, Katarzyna

    2015-03-01

    The present study is aimed at formulation of alginate (ALG) microspheres with ranitidine (RNT) by the spray drying method. Obtained microspheres were characterized for particle size, surface morphology, entrapment efficiency, drug loading, in vitro drug release and zeta potential. Mucoadhesive properties were examined by a texture analyser and three types of adhesive layers--gelatine discs, mucin gel and porcine stomach mucosa. Microspheres showed a smooth surface with narrow particle size distribution and RNT loading of up to 70.9%. All formulations possessed mucoadhesive properties and exhibited prolonged drug release according to the first-order kinetics. DSC reports showed that there was no interaction between RNT and ALG. Designed microspheres can be considered potential carriers of ranitidine with prolonged residence time in the stomach.

  20. Variability of bandgap and carrier mobility caused by edge defects in ultra-narrow graphene nanoribbons

    Science.gov (United States)

    Poljak, M.; Wang, K. L.; Suligoj, T.

    2015-06-01

    We report the results of multi-scale modeling of ultra-narrow graphene nanoribbons (GNRs) that combines atomistic non-equilibrium Green's function (NEGF) approach with semiclassical mobility modeling. The variability of the transport gap and carrier mobility caused by random edge defects is analyzed. We find that the variability increases as the GNR width is downscaled and that even the minimum variation of the total mobility reaches more than 100% compared to average mobility in edge-defected nanoribbons. It is shown that scattering by optical phonons exhibits significantly more variability than the acoustic, line-edge roughness and Coulomb scattering mechanisms. The simulation results demonstrate that sub-5 nm-wide nanoribbons offer no improvement over conventional bulk semiconductors, however, GNRs are comparable with sub-7 nm-thick silicon-on-insulator devices in terms of mobility-bandgap trade-off characteristics.

  1. AB-stacked multilayer graphene synthesized via chemical vapor deposition: a characterization by hot carrier transport.

    Science.gov (United States)

    Diaz-Pinto, Carlos; De, Debtanu; Hadjiev, Viktor G; Peng, Haibing

    2012-02-28

    We report the synthesis of AB-stacked multilayer graphene via ambient pressure chemical vapor deposition on Cu foils and demonstrate a method to construct suspended multilayer graphene devices. In four-terminal geometry, such devices were characterized by hot carrier transport at temperatures down to 240 mK and in magnetic fields up to 14 T. The differential conductance (dI/dV) shows a characteristic dip at longitudinal voltage bias V = 0 at low temperatures, indicating the presence of hot electron effect due to a weak electron-phonon coupling. Under magnetic fields, the magnitude of the dI/dV dip diminishes through the enhanced intra-Landau level cyclotron phonon scattering. Our results provide new perspectives in obtaining and understanding AB-stacked multilayer graphene, important for future graphene-based applications.

  2. Enhanced butanol production by immobilized Clostridium beijerinckii TISTR 1461 using zeolite 13X as a carrier.

    Science.gov (United States)

    Vichuviwat, Rapeephat; Boonsombuti, Akarin; Luengnaruemitchai, Apanee; Wongkasemjit, Sujitra

    2014-11-01

    Butanol production by cell immobilization onto porous materials-brick and zeolite 13X-was investigated using Clostridium beijerinckii TISTR 1461. Characterization results of two materials were completed to evaluate their potential as an immobilization carrier. Although zeolite has greater porosity than brick, it cannot be used for cell aggregation without treating with chemical. After immobilization, both materials can enhance butanol titers from 5.29 to 5.80g/L and 8.58g/L using brick and zeolite, respectively. Butanol to glucose yield also improved from 0.14 to 0.16g/g after immobilization. It was found that butanol production significantly increased due to an increase in buffering capacity, strong bonding between the zeolite surface and cell, and butanol tolerance. In addition, repeated batch fermentation was performed, demonstrating that cells immobilized onto zeolite 13X have high stability and potential for long-term use in continuous fermentation.

  3. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    DEFF Research Database (Denmark)

    Houen, G.; Olsen, D.T.; Hansen, P.R.;

    2003-01-01

    A solid-phase conjugation method utilizing carrier protein bound to an ion exchange matrix was developed. Ovalbumin was adsorbed to an anion exchange matrix using a batch procedure, and the immobilized protein was then derivatized with iodoacetic acid N-hydroxysuccinimid ester. The activated......, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates...... of ovalbumin and various peptides were prepared in a similar manner and used for production of peptide antisera by direct immunization with the conjugates bound to the ion exchanger. Advantages of the method are its solid-phase nature, allowing fast and efficient reactions and intermediate washings...

  4. Attenuating the size and molecular carrier capabilities of polyacrylate nanoparticles by a hydrophobic fluorine effect.

    Science.gov (United States)

    Labruère, Raphaël; Turos, Edward

    2012-08-15

    This study investigates the effect of introducing alkyl chain fluorination on the properties of polyacrylate nanoparticles prepared in aqueous solution by emulsion polymerization. For this, 2,2,3,3,4,4,4-heptafluorobutyl acrylate (1) and methyl trifluoroacrylate (2) were tested as monomers as a means to prepare fluorinated polyacrylate nanoparticles to evaluate how side chain fluorination may affect nanoparticle size and drug carrier properties. Our results show that as fluorine content within the polyacrylate matrix increases, the size of the nanoparticle systematically diminishes, from 45 nm (for nanoparticles containing no fluoroacrylate) to ~7 nm (for nanoparticles constructed solely of fluoroacrylate). We also observe that as fluoroacrylate content and hydrophobicity increases, the nanoparticles decrease their ability to incorporate lipophilic molecules during the process of emulsification. These findings have meaningful implications in the implementation of fluorinated nanoparticles in molecular delivery.

  5. Vibration of low amplitude imaged in amplitude and phase by sideband versus carrier correlation digital holography

    CERN Document Server

    Verrier, N; Gross, M

    2015-01-01

    Sideband holography can be used to get fields images (E0 and E1) of a vibrating object for both the carrier (E0) and the sideband (E1) frequency with respect to vibration. We propose here to record E0 and E1 sequentially, and to image the correlation E1E * 0 . We show that this correlation is insensitive the phase related to the object roughness and directly reflect the phase of the mechanical motion. The signal to noise can be improved by averaging the correlation over neighbor pixel. Experimental validation is made with vibrating cube of wood and with a clarinet reed. At 2 kHz, vibrations of amplitude down to 0.01 nm are detected.

  6. Defect Modes in Multiple-Constituent One-Dimensional Photonic Crystals Examined by an Analytic Bloch-Mode Approach

    Institute of Scientific and Technical Information of China (English)

    SANG Hong-Yi; LI Zhi-Yuan; GU Ben-Yuan

    2005-01-01

    @@ Defect modes in one-dimensional photonic crystals (PCs) can be readily detected from the solution of the transmission spectra via the standard transfer-matrix method. We adopt an analytic Bloch-mode approach to examine this problem in terms of eigenmode solutions and investigate the dispersion behaviour of localized defect modes supported by a defect layer sandwiched within two symmetric semi-infinite PCs that are made from multiple constituents. The results show that the number of defect modes grows when the dielectric constant and width of the defect layer increase.

  7. DNA stabilization by the upregulation of estrogen signaling in BRCA gene mutation carriers.

    Science.gov (United States)

    Suba, Zsuzsanna

    2015-01-01

    Currently available scientific evidence erroneously suggests that mutagenic weakness or loss of the BRCA1/2 genes may liberate the proliferative effects of estrogen signaling, which provokes DNA damage and genomic instability. Conversely, BRCA mutation seems to be an imbalanced defect, crudely inhibiting the upregulation of estrogen receptor expression and liganded transcriptional activity, whereas estrogen receptor-repressor functions become predominant. In BRCA-proficient cases, estrogen signaling orchestrates the activity of cell proliferation and differentiation with high safety, while upregulating the expression and DNA-stabilizing impact of BRCA genes. In turn, BRCA proteins promote estrogen signaling by proper estrogen synthesis via CYP19 gene regulation and by induction of the appropriate expression and transcriptional activity of estrogen receptors. In this exquisitely organized regulatory system, the dysfunction of each player may jeopardize genome stability and lead to severe chronic diseases, such as cancer development. Female organs, such as breast, endometrium, and ovary, exhibiting regular cyclic proliferative activity are particularly vulnerable in case of disturbances in either estrogen signaling or BRCA-mediated DNA repair. BRCA mutation carrier women may apparently be healthy or exhibit clinical signs of deficient estrogen signaling in spite of hyperestrogenism. Even women who enjoy sufficient compensatory DNA-defending activities are at risk of tumor development because many endogenous and environmental factors may jeopardize the mechanisms of extreme compensatory processes. Natural estrogens have numerous benefits in tumor prevention and therapy even in BRCA mutation carriers. There are no toxic effects even in sky-high doses and all physiologic cellular functions are strongly upregulated, while malignant tumor cells are recognized and killed in a Janus-faced manner.

  8. Improvement of oral bioavailability of lovastatin by using nanostructured lipid carriers

    Directory of Open Access Journals (Sweden)

    Zhou J

    2015-09-01

    Full Text Available Jun Zhou,1,2 Daxin Zhou3 1Department of Medicine, Clinical Medical College of Soochow University, 2Department of Medicine, Tongren Hospital, Shanghai Jiaotong University School of Medicine, 3Department of Cardiovascular Medicine, Zhongshan Hospital, Fudan University, Shanghai, People’s Republic of China Abstract: Nanostructured lipid carriers (NLCs have been one of the systems of choice for improving the oral bioavailability of drugs with poor water solubility. In the present study, lovastatin (LVT-loaded NLCs (LVT-NLCs were successfully prepared by hot high-pressure homogenization method with high entrapment efficiency, drug loading, and satisfactory particle size distribution. The particles had almost spherical and uniform shapes and were well dispersed with a particle size of <50 nm (23.5±1.6 nm and a low polydispersity index (0.17±0.05 mV. The result of stability showed that the LVT-NLCs dispersion maintained excellent stability without exhibiting any aggregation, precipitation, or phase separation at 4°C for 6 months of storage. The LVT release data from all developed solid lipid nanoparticles (SLNs and NLCs were best fitted to a Ritger–Peppas kinetic model (0.9832 and 0.9783 for NLCs and SLNs, respectively. This indicated that the release of LVT from the SLNs and NLCs was due to a combination of drug diffusion and erosion from the lipid matrix. The pharmacokinetic and pharmacodynamic results show that LVT-NLCs were better compared to free drug, which could be attributed to an increase in bioavailability. Keywords: nanostructured lipid carriers, lovastatin, in vitro release, pharmacokinetic, pharmacodynamic

  9. Monitoring Biological Modes in a Bioreactor Process by Computer Simulation

    Directory of Open Access Journals (Sweden)

    Samia Semcheddine

    2015-12-01

    Full Text Available This paper deals with the general framework of fermentation system modeling and monitoring, focusing on the fermentation of Escherichia coli. Our main objective is to develop an algorithm for the online detection of acetate production during the culture of recombinant proteins. The analysis the fermentation process shows that it behaves like a hybrid dynamic system with commutation (since it can be represented by 5 nonlinear models. We present a strategy of fault detection based on residual generation for detecting the different actual biological modes. The residual generation is based on nonlinear analytical redundancy relations. The simulation results show that the several modes that are occulted during the bacteria cultivation can be detected by residuals using a nonlinear dynamic model and a reduced instrumentation.

  10. Theoretic base of Edge Local Mode triggering by vertical displacements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z. T. [Southwestern Institute of Physics, Chengdu 610041 (China); College of Physics Science and Technology, Sichuan University, Chengdu 610065 (China); He, Z. X.; Wang, Z. H. [Southwestern Institute of Physics, Chengdu 610041 (China); Wu, N.; Tang, C. J. [College of Physics Science and Technology, Sichuan University, Chengdu 610065 (China)

    2015-05-15

    Vertical instability is studied with R-dependent displacement. For Solovev's configuration, the stability boundary of the vertical instability is calculated. The pressure gradient is a destabilizing factor which is contrary to Rebhan's result. Equilibrium parallel current density, j{sub //}, at plasma boundary is a drive of the vertical instability similar to Peeling-ballooning modes; however, the vertical instability cannot be stabilized by the magnetic shear which tends towards infinity near the separatrix. The induced current observed in the Edge Local Mode (ELM) triggering experiment by vertical modulation is derived. The theory provides some theoretic explanation for the mitigation of type-I ELMS on ASDEX Upgrade. The principle could be also used for ITER.

  11. Increased reliability of passive mode-locking a multi-atmosphere TE CO2 laser by injection mode-locking

    NARCIS (Netherlands)

    Goor, van F.A.

    1986-01-01

    By injection of manosecond pulses from an AM mode-locked TEA CO2 laser in a passive mode-locked multi-atmosphere TE CO2 laser the shot-to-shot reproducibility of the generated subnanosecond pulses was increased to almost 100%.

  12. Production of Heavy Ion Beams by Operating Serse in DC Mode and Afterglow Mode

    CERN Document Server

    Gammino, S; Celona, L; Girard, A; Hitz, D; Melin, G

    2000-01-01

    The superconducting ECR ion source SERSE is going to be coupled to a 28 GHz generator, in order to achieve higher current of intermediate and high charge states of heavy ions. Some preliminary tests have been carried out to $9 demonstrate the capability to produce currents of heavy ion beams in the order of hundreds emA in dc mode and afterglow mode. In particular, the latter tests in afterglow mode ùay play a relevant role in the design of the new source $9 for the LHC heavy ion injector.

  13. Digital wavelength switching by thermal and carrier injection effects in V-coupled cavity semiconductor laser

    Institute of Scientific and Technical Information of China (English)

    Jialiang Jin; Lei Wang; Jianjun He

    2012-01-01

    Consecutive wavelength switching characteristics of a simple,compact,and digitally wavelength-switchable laser based on V-coupled cavities are reported.Wavelength switching through thermal and carrier injection effects is examined.Without using band gap engineering for the tuning section,26- and 9-channel wavelength switching schemes are achieved via thermal and carrier injection effects,respectively.The performances of these two tuning schemes are then compared.

  14. Detection of Duchenne/Becker Muscular Dystrophy Carriers in a Group of Iranian Families by Linkage Analysis

    Directory of Open Access Journals (Sweden)

    Fardeen Ali Malayeri

    2011-03-01

    Full Text Available This study determines the value of linkage analysis using six RFLP markers for carrier detection and prenatal diagnosis in familial DMD/BMD cases and their family members for the first time in the Iranian population. We studied the dystrophin gene in 33 unrelated patients with clinical diagnosis of DMD or BMD. Subsequently, we determined the rate of heterozygosity for six intragenic RFLP markers in the mothers of patients with dystrophin gene deletions. Finally, we studied the efficiency of linkage analysis by using RFLP markers for carrier status detection of DMD/BMD. In 63.6% of the patients we found one or more deletions. The most common heterozygous RFLP marker with 57.1% heterozygosity was pERT87.15Taq1. More than 80% of mothers in two groups of familial or non-familial cases had at least two heterozygous markers. Family linkage analysis was informative in more than 80% of the cases, allowing for accurate carrier detection. We found that linkage analysis using these six RFLP markers for carrier detection and prenatal diagnosis is a rapid, easy, reliable, and inexpensive method, suitable for most routine diagnostic services. The heterozygosity frequency of these markers is high enough in the Iranian population to allow carrier detection and prenatal diagnosis of DMD/BMD in more than 80% of familial cases in Iran.

  15. Detection of Helicobacter pylori carriers by discriminant analysis of urea and pH levels in gastric juices.

    Science.gov (United States)

    Ameglio, F; Abbolito, M R; Giannarelli, D; Citarda, F; Grassi, A; Gandolfo, G M; Casale, V

    1991-08-01

    An alternative approach to the problems inherent in current methods for detecting Helicobacter pylori carriers--that of being generally time-consuming, expensive, and not sufficiently sensitive--was devised by using the urea concentration and pH levels of gastric juices. A linear discriminant analysis of these variables, measured in 54 patients submitted to digestive endoscopy for gastritis, provided a mathematical formula for assigning the subjects (previously classified by other standard methods) to groups of either positive or negative H pylori carriers. The results obtained showed a correct classification in 52 out of 54 cases with only one false negative and one false positive case.

  16. Identification of Leptospira spp. carriers among seroreactive goats and sheep by polymerase chain reaction.

    Science.gov (United States)

    Lilenbaum, W; Varges, R; Ristow, P; Cortez, A; Souza, S O; Richtzenhain, L J; Vasconcellos, S A

    2009-08-01

    Few studies were conducted on the diagnosis and control of small ruminants' leptospirosis. Thirteen goat herds and seven sheep flocks located in the state of Rio de Janeiro, Brazil, were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity by MAT (Microscopic Agglutination Test), 19 and 40 seropositive goats and sheep, respectively, were selected, and urine samples were collected for bacteriology and PCR. For both species of animals, the most prevalent reactions were due to serogroups Sejroe and Shermani. Although leptospires were observed by darkfield microscopy in eight samples, pure isolates were obtained by bacteriological culture from only two samples. However, twelve urine samples (six goats and six sheep) were positive by PCR. Based on these findings, we consider that the combined use of MAT as a screening test followed by urine PCR for the direct detection of Leptospira spp. DNA was adequate for the identification of carrier animals among goats and sheep. These are valuable tools for the control of leptospirosis in small ruminants.

  17. Axisymmetric Scattering of p Modes by Thin Magnetic Tubes

    CERN Document Server

    Hindman, Bradley W

    2011-01-01

    We examine the scattering of acoustic p-mode waves from a thin magnetic fibril embedded in a gravitationally stratified atmosphere. The scattering is mediated through the excitation of slow sausage waves on the magnetic tube, and only the scattering of the monopole component of the wavefield is considered. Since such tube waves are not confined by the acoustic cavity and may freely propagate along the field lines removing energy from the acoustic wavefield, the excitation of fibril oscillations is a source of acoustic wave absorption as well as scattering. We compute the mode mixing that is achieved and the absorption coefficients and phase shifts that would be measured in a Fourier-Hankel decomposition. We find that for thin tubes the mode mixing is weak and the absorption coefficient is small and is a smooth function of frequency over the physically relevant band of observed frequencies. The prominent absorption resonances seen in previous studies of unstratified tubes are absent. Despite the relatively sma...

  18. Transportation mode detection by using smartphone sensors and machine learning

    Directory of Open Access Journals (Sweden)

    Ensar Arif Sağbaş

    2016-10-01

    Full Text Available The aim of this study is to detect transportation modes of the users by using smartphone sensors. Therefore, GPS (Global Positioning System, accelerometer and gyroscope sensor data have been collected while walking, running, cycling and travelling by bus or by car from the smartphone of the user. Sensor data were tagged with 12 second interval and 2500 pattern were obtained. 14 features were acquired from the dataset. Machine learning methods were tested on the dataset. Best result was obtained from GPS, accelerometer and gyroscope sensor combination and Random Forest method with 99.4% accuracy rate.

  19. Neoclassical tearing mode seeding by coupling with infernal modes in low-shear tokamaks

    Science.gov (United States)

    Kleiner, A.; Graves, J. P.; Brunetti, D.; Cooper, W. A.; Halpern, F. D.; Luciani, J.-F.; Lütjens, H.

    2016-09-01

    A numerical and an analytical study of the triggering of resistive MHD modes in tokamak plasmas with low magnetic shear core is presented. Flat q profiles give rise to fast growing pressure driven MHD modes, such as infernal modes. It has been shown that infernal modes drive fast growing islands on neighbouring rational surfaces. Numerical simulations of such instabilities in a MAST-like configuration are performed with the initial value stability code XTOR-2F in the resistive frame. The evolution of magnetic islands are computed from XTOR-2F simulations and an analytical model is developed based on Rutherford’s theory in combination with a model of resistive infernal modes. The parameter {{Δ }\\prime} is extended from the linear phase to the non-linear phase. Additionally, the destabilising contribution due to a helically perturbed bootstrap current is considered. Comparing the numerical XTOR-2F simulations to the model, we find that coupling has a strong destabilising effect on (neoclassical) tearing modes and is able to seed 2/1 magnetic islands in situations when the standard NTM theory predicts stability.

  20. Enhancement of minority carrier lifetime of GaInP with lateral composition modulation structure grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Park, K. W.; Ravindran, Sooraj; Kang, S. J.; Hwang, H. Y.; Jho, Y. D. [School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Park, C. Y. [School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Jo, Y. R.; Kim, B. J. [School of Material Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Y. T., E-mail: ytlee@gist.ac.kr [School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-07-28

    We report the enhancement of the minority carrier lifetime of GaInP with a lateral composition modulated (LCM) structure grown using molecular beam epitaxy (MBE). The structural and optical properties of the grown samples are studied by transmission electron microscopy and photoluminescence, which reveal the formation of vertically aligned bright and dark slabs corresponding to Ga-rich and In-rich GaInP regions, respectively, with good crystal quality. With the decrease of V/III ratio during LCM GaInP growth, it is seen that the band gap of LCM GaInP is reduced, while the PL intensity remains high and is comparable to that of bulk GaInP. We also investigate the minority carrier lifetime of LCM structures made with different flux ratios. It is found that the minority carrier lifetime of LCM GaInP is ∼37 times larger than that of bulk GaInP material, due to the spatial separation of electrons and holes by In-rich and Ga-rich regions of the LCM GaInP, respectively. We further demonstrate that the minority carrier lifetime of the grown LCM GaInP structures can easily be tuned by simply adjusting the V/III flux ratio during MBE growth, providing a simple yet powerful technique to tailor the electrical and optical properties at will. The exceptionally high carrier lifetime and the reduced band gap of LCM GaInP make them a highly attractive candidate for forming the top cell of multi-junction solar cells and can enhance their efficiency, and also make them suitable for other optoelectronics devices, such as photodetectors, where longer carrier lifetime is beneficial.

  1. Hot Carrier Dynamics in the X Valley in Si and Ge Measured by Pump-IR-Probe Absorption Spectroscopy

    Science.gov (United States)

    Wang, W. B.; Cavicchia, M. A.; Alfano, R. R.

    1996-01-01

    Si is the semiconductor of choice for nanoelectronic roadmap into the next century for computer and other nanodevices. With growing interest in Si, Ge, and Si(sub m)Ge(sub n) strained superlattices, knowledge of the carrier relaxation processes in these materials and structures has become increasingly important. The limited time resolution for earlier studies of carrier dynamics in Ge and Si, performed using Nd:glass lasers, was not sufficient to observe the fast cooling processes. In this paper, we present a direct measurement of hot carrier dynamics in the satellite X valley in Si and Ge by time-resolved infrared(IR) absorption spectroscopy, and show the potential of our technique to identify whether the X valley is the lowest conduction valley in semiconductor materials and structures.

  2. Removal of odorous compounds from poultry manure by microorganisms on perlite--bentonite carrier.

    Science.gov (United States)

    Gutarowska, Beata; Matusiak, Katarzyna; Borowski, Sebastian; Rajkowska, Aleksandra; Brycki, Bogumił

    2014-08-01

    Laboratory-scale experiments were conducted using poultry manure (PM) from a laying hen farm. Six strains of bacteria and one strain of yeast, selected on the base of the previous study, were investigated to evaluate their activity in the removal of odorous compounds from poultry manure: pure cultures of Bacillus subtilis subsp. spizizenii LOCK 0272, Bacillus megaterium LOCK 0963, Pseudomonas sp. LOCK 0961, Psychrobacter faecalis LOCK 0965, Leuconostoc mesenteroides LOCK 0964, Streptomyces violaceoruber LOCK 0967, and Candida inconspicua LOCK 0272 were suspended in water solution and applied for PM deodorization. The most active strains in the removal of volatile odorous compounds (ammonia, hydrogen sulfide, dimethylamine, trimethylamine, isobutyric acid) belonged to B. subtilis subsp. spizizenii, L. mesenteroides, C. inconspicua, and P. faecalis. In the next series of experiments, a mixed culture of all tested strains was immobilized on a mineral carrier being a mixture of perlite and bentonite (20:80 by weight). That mixed culture applied for PM deodorization was particularly active against ammonia and hydrogen sulfide, which were removed from the exhaust gas by 20.8% and 17.5%, respectively. The experiments also showed that during deodorization the microorganisms could reduce the concentrations of proteins and amino acids in PM. In particular, the mixed culture was active against cysteine and methionine, which were removed from PM by around 45% within 24 h of deodorization.

  3. Attitudes of families affected by adrenoleukodystrophy toward prenatal diagnosis, presymptomatic and carrier testing, and newborn screening.

    Science.gov (United States)

    Schaller, Jean; Moser, Hugo; Begleiter, Michael L; Edwards, Janice

    2007-01-01

    Families affected by adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN) were surveyed to elicit attitudes toward prenatal, presymptomatic and carrier testing, and newborn screening in order to determine the level of support that these families have for current and future genetic testing protocols. Identifying attitudes toward genetic testing, including newborn screening, is especially important because of new data regarding therapeutic options and the possible addition of ALD to newborn screening regimens. The Kennedy Krieger Institute (KKI) database identified 327 prospective participants. Families that were willing to participate in the study received an anonymous questionnaire for completion. Frequencies were generated using SPSS software for Windows. Questionnaires were returned from 128 families for a response rate of 39%. Sons who were at risk for inheriting the ALD gene would be tested by 93% of respondents, and 89.3% would ideally have this testing performed prenatally or in the newborn period. Eighty-nine percent would test an at-risk daughter and 51.2% would ideally have this testing performed prenatally or shortly after birth. ALD newborn screening for males and females was supported by 90% of respondents. If newborn screening for ALD/AMN commences, or there is a new diagnosis of ALD, genetic professionals need to be prepared to have extensive conversations with families regarding the benefits and limitations of current therapeutic and genetic testing options.

  4. Characterization of chicken riboflavin carrier protein gene structure and promoter regulation by estrogen

    Indian Academy of Sciences (India)

    Nandini Vasudevan; Urvashi Bahadur; Paturu Kondaiah

    2001-03-01

    The chicken riboflavin carrier protein (RCP) is an estrogen induced egg yolk and white protein. Eggs from hens which have a splice mutation in RCP gene fail to hatch, indicating an absolute requirement of RCP for the transport of riboflavin to the oocyte. In order to understand the mechanism of regulation of this gene by estrogen, the chicken RCP gene including 1 kb of the 5′ flanking region has been isolated. Characterization of the gene structure shows that it contains six exons and five introns, including an intron in the 5′ untranslated region. Sequence analysis of the 5′ flanking region does not show the presence of any classical, palindromic estrogen response element (ERE). However, there are six half site ERE consensus elements. Four deletion constructs of the 5′ flanking region with varying number of ERE half sites were made in pGL3 basic vector upstream of the luciferase-coding region. Transient transfection of these RCP promoter deletion constructs into a chicken hepatoma cell line (LMH2A) showed 6-12-fold transcriptional induction by a stable estrogen analogue, moxesterol. This suggests that the RCP gene is induced by estrogen even in the absence of a classical ERE and the half sites of ERE in this promoter may be important for estrogen induction.

  5. Study of Mg Powder as Catalyst Carrier for the Carbon Nanotube Growth by CVD

    Directory of Open Access Journals (Sweden)

    Jianli Kang

    2011-01-01

    Full Text Available The possibility of using magnesium powder as catalyst carrier for carbon nanotube growth by chemical vapor deposition, which may pave a new way to in situ fabricate CNT/Mg composites with high CNT dispersion, was investigated for the first time. The fabrication process of the catalyst supported on Mg powder involves the preparation of colloid by a deposition-precipitation method, followed by calcination and reduction. The results show that the interaction between catalyst and support plays an important role for the catalytic property of the catalyst. Ni alloyed with Mg shows no activity for the decomposition of methane. The introduction of Y in Ni/Mg catalyst can promote the reaction temperature between Ni and Mg and thus enhance the activity of the catalyst. A large amount of carbon nanotubes (CNTs with an average diameter of 20 nm was obtained using Ni/Y/Mg catalyst at 450∘C, while only a few short CNTs were obtained using Ni/Mg catalyst due to the low activity of the catalyst at lower temperature.

  6. Minority Carrier Electron Traps in CZTSSe Solar Cells Characterized by DLTS and DLOS

    Energy Technology Data Exchange (ETDEWEB)

    Kheraj, V.; Lund, E. A.; Caruso, A. E.; Al-Ajmi, K.; Pruzan, D.; Miskin, C.; Agrawal, R.; Beall, Carolyn; Repins, Ingrid; Scarpulla, M. A.

    2016-11-21

    We report observations of minority carrier interactions with deep levels in 6-8% efficient Cu2ZnSn(S, Se)4 (CZTSSe) devices using conventional and minority deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS). Directly observing defect interactions with minority carriers is critical to understanding the recombination impact of deep levels. In devices with Cu2ZnSn(S, Se)4 nanoparticle ink absorber layers we identify a mid-gap state capturing and emitting minority electrons. It is 590+/-50 meV from the conduction band mobility edge, has a concentration near 1015/cm3, and has an apparent electron capture cross section ~10-14 cm2. We conclude that, while energetically positioned nearly-ideally to be a recombination center, these defects instead act as electron traps because of a smaller hole cross-section. In CZTSe devices produced using coevaporation, we used minority carrier DLTS on traditional samples as well as ones with transparent Ohmic back contacts. These experiments demonstrate methods for unambiguously probing minority carrier/defect interactions in solar cells in order to establish direct links between defect energy level observations and minority carrier lifetimes. Furthermore, we demonstrate the use of steady-state device simulation to aid in the interpretation of DLTS results e.g. to put bounds on the complimentary carrier cross section even in the absence its direct measurement. This combined experimental and theoretical approach establishes rigorous bounds on the impact on carrier lifetime and Voc of defects observed with DLTS as opposed to, for example, assuming that all deep states act as strong recombination centers.

  7. Thermal image filtering by bi-dimensional empirical mode decomposition

    Science.gov (United States)

    Gavriloaia, Bogdan-Mihai; Vizireanu, Constantin-Radu; Fratu, Octavian; Mara, Constantin; Vizireanu, Dragos-Nicolae; Preda, Radu; Gavriloaia, Gheorghe

    2015-02-01

    The abnormal function of cells can be detected by anatomic or physiological registrations. Most of modern approaches, as ultrasound, RMN or CT, show anatomic parametric modifications of tissues or organs. They highlight areas with a larger diameter 1 cm. In the case of skin or superficial cancers, local temperature is different, and it can be put out by thermal imager. Medical imaging is a leading role in modern diagnosis for abnormal or normal tissues or organs. Some information has to be improved for a better diagnosis by reducing or removing some unwanted information like noise affecting image texture. The traditional technologies for medical image enhancement use spatial or frequency domain methods, but whole image processing will hide both partial and specific information for human signals. A particular kind of medical images is represented by thermal imaging. Recently, these images were used for skin or superficial cancers diagnosis, but very clear outlines of certain alleged affected areas need to be shown. Histogram equalization cannot highlights the edges and control the effects of enhancement. A new filtering method was introduced by Huang by using the empirical mode decomposition, EMD. An improved filtering method for thermal images, based on EMD, is presented in this paper, and permits to analyze nonlinear and non-stationary data by the adaptive decomposition into intrinsic mode surfaces. The results, evaluated by SNR ratios, are compared with other filtering methods.

  8. Magnetohydrodynamic instability excited by interplay between a resistive wall mode and stable ideal magnetohydrodynamic modes in rotating tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Aiba, N. [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Hirota, M. [Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2015-08-15

    In a rotating toroidal plasma surrounded by a resistive wall, it is shown that linear magnetohydrodynamic (MHD) instabilities can be excited by interplay between the resistive wall mode (RWM) and stable ideal MHD modes, where the RWM can couple with not only a stable external kink mode but also various stable Alfvén eigenmodes that abound in a toroidal plasma. The RWM growth rate is shown to peak repeatedly as the rotation frequency reaches specific values for which the frequencies of the ideal MHD modes are Doppler-shifted to the small RWM frequency. Such destabilization can be observed even when the RWM in a static plasma is stable. A dispersion relation clarifies that the unstable mode changes from the RWM to the ideal MHD mode destabilized by wall resistivity when the rotation frequency passes through these specific values. The unstable mode is excited at these rotation frequencies even though plasma rotation also tends to stabilize the RWM from the combination of the continuum damping and the ion Landau damping.

  9. Ultrafast Carrier Dynamics Measured by the Transient Change in the Reflectance of InP and GaAs Film

    Energy Technology Data Exchange (ETDEWEB)

    Klopf, John [Helmholtz Association of German Research Centers, Dresden (Germany)

    2005-10-31

    Advancements in microfabrication techniques and thin film growth have led to complex integrated photonic devices, also known as optoelectronics. The performance of these devices relies upon precise control of the band gap and optical characteristics of the thin film structures, as well as a fundamental understanding of the photoexcited carrier thermalization, relaxation, and recombination processes. An optical pump-probe technique has been developed to measure the transient behavior of these processes on a sub-picosecond timescale. This method relies upon the generation of hot carriers by theabsorption of an intense ultrashort laser pulse (~ 135 fs). The transient changes in reflectance due to the pump pulse excitation are monitored using a weaker probe pulse. Control of the relative time delay between the pump and probe pulses allows for temporal measurements with resolution limited only by the pulse width. The transient change in reflectance is the result of a transient change in the carrier distribution. Observation of the reflectance response of indium phosphide (InP) and gallium arsenide (GaAs) films on a sub-picosecond timescale allows for detailed examination of thermalization and relaxation processes of the excited carriers. Longer timescales (> 100 ps) are useful for correlating the transient reflectance response to slower processes such as the diffusion and recombination of the photoexcited carriers. This research investigates the transient hot carrier processes in several InP and GaAs based films similar to those commonly used in optoelectronics. This technique is especially important as it provides a non-destructive means of evaluating these materials; whereas much of the research performed in this field has relied upon the measurement of transient changes in the transmission of transparent films. The process of preparing films that are transparent renders them unusable in functioning devices. This research should not only extend the understanding of

  10. 42 CFR 421.200 - Carrier functions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Carrier functions. 421.200 Section 421.200 Public...) MEDICARE PROGRAM MEDICARE CONTRACTING Carriers § 421.200 Carrier functions. A contract between CMS and a carrier specifies the functions to be performed by the carrier. The contract may include any or all of...

  11. HYDRODYNAMIC INTERACTION BETWEEN FLNG VESSEL AND LNG CARRIER IN SIDE BY SIDE CONFIGURATION

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-hua; YANG Jian-min; HU Zhi-qiang

    2012-01-01

    The Floating Liquefied Natural Gas (FLNG) is a new type of floating platform for the exploitation of stranded offshore oil/gas fields.The side by side configuration for the FLNG vessel and the LNG carrier arranged in parallel is one of the possible choices for the LNG offloading.During the offioading operations,the multiple floating bodies would have very complex responses due to their hydrodynamic interactions.In this study,numerical simulations of multiple floating bodies in close proximity in the side by side offioading configuration are carried out with the time domain coupled analysis code SIMO.Hydrodynamic interactions between the floating bodies and the mechanical coupling effects between the floating bodies and their connection systems are included in the coupled analysis model.To clarify the hydrodynamic effects of the two vessels,numerical simulations under the same environmental condition are also conducted without considering the hydrodynamic interactions,for comparison.It is shown that the hydrodynamic interactions play an important role in the low frequency motion responses of the two vessels,but have little effect on the wave frequency motion responses.In addition,the comparison results also show that the hydrodynamic interactions can affect the loads on the connection systems.

  12. Measuring the carrier lifetime by using a quasi-optical millimeter- and THz-wave system

    Science.gov (United States)

    Choe, Mun Seok; Sawant, Ashwini; Lee, Kyu-Sup; Yu, Nan Ei; Choi, EunMi

    2017-02-01

    The existing method for contactless measurement of the photoconductivity decay time is limited in terms of sample selection according to the injection level or doping density. To solve this problem and improve the measurement sensitivity, we developed a quasi-optical photoconductivity decay (QO-PCD) technique based on millimeter- and terahertz-wave technology. A semi-insulating silicon (Si) wafer was used in a proof-of-concept experiment with the proposed QO-PCD system to find the initial excess carrier density and carrier lifetime based on the Drude-Zener model with a single decay function. The initial excess carrier density and carrier lifetime were measured to be 1.5 × 1015 cm-3 and 30.6 μs, respectively, in semi-insulating Si wafer (460 μm thickness). A 2D areal measurement of the decay time of the Si wafer was experimentally obtained. The proposed QO-PCD technique can provide more reliable and sensitive carrier lifetime measurement data for semiconductor wafers, which may impact the fields of photovoltaic solar cells and power electronics.

  13. Carrier Density and Plasma Frequency of Aluminum Nanofilms

    Institute of Scientific and Technical Information of China (English)

    Hao DU; Jun GONG; Chao SUN; Rongfang HUANG; Lishi WEN; W.Y.Cheung; S.P.Wong

    2003-01-01

    In this work, the prerequisite and mode of electromagnetic response of Al nanofilms to electromagnetic wave field was suggested.Reflectance, transmittance in infrared region and carrier density of the films was measured. With the carrier density of the films, the dependence of their plasma frequencies on the film thickness was obtained. On the other hand, the dependence of absorptance on the frequency of electromagnetic wave field was set up by using the measured reflectance and transmittance,which provided plasma frequency-film thickness relation as well. Similarity of both plasma frequency-film thickness relations proved plasma resonance as a mode of electromagnetic response in Al nanofilms.

  14. Lysine and arginine biosyntheses mediated by a common carrier protein in Sulfolobus.

    Science.gov (United States)

    Ouchi, Takuya; Tomita, Takeo; Horie, Akira; Yoshida, Ayako; Takahashi, Kento; Nishida, Hiromi; Lassak, Kerstin; Taka, Hikari; Mineki, Reiko; Fujimura, Tsutomu; Kosono, Saori; Nishiyama, Chiharu; Masui, Ryoji; Kuramitsu, Seiki; Albers, Sonja-Verena; Kuzuyama, Tomohisa; Nishiyama, Makoto

    2013-04-01

    LysW has been identified as a carrier protein in the lysine biosynthetic pathway that is active through the conversion of α-aminoadipate (AAA) to lysine. In this study, we found that the hyperthermophilic archaeon, Sulfolobus acidocaldarius, not only biosynthesizes lysine through LysW-mediated protection of AAA but also uses LysW to protect the amino group of glutamate in arginine biosynthesis. In this archaeon, after LysW modification, AAA and glutamate are converted to lysine and ornithine, respectively, by a single set of enzymes with dual functions. The crystal structure of ArgX, the enzyme responsible for modification and protection of the amino moiety of glutamate with LysW, was determined in complex with LysW. Structural comparison and enzymatic characterization using Sulfolobus LysX, Sulfolobus ArgX and Thermus LysX identify the amino acid motif responsible for substrate discrimination between AAA and glutamate. Phylogenetic analysis reveals that gene duplication events at different stages of evolution led to ArgX and LysX.

  15. Lymph cancer chemotherapy: delivery of doxorubicin–gemcitabine prodrug and vincristine by nanostructured lipid carriers

    Science.gov (United States)

    Ni, Shuqin; Qiu, Lei; Zhang, Guodong; Zhou, Haiyan; Han, Yong

    2017-01-01

    Purpose Radiation and chemotherapy are the most common course of treatment for B-cell lymphoma. Doxorubicin (DOX), gemcitabine (GEM), and vincristine (VCR) are the commonly used antilymphoma chemotherapeutic drugs. The aim of this study is to construct a novel drug delivery system for the combination delivery of the three drugs on lymphoma. Materials and methods DOX–GEM prodrug was synthesized. Novel nanostructured lipid carriers (NLCs) containing DOX–GEM prodrug and VCR were prepared and used to treat B-cell lymphoma through in vivo treatment to a lymph cancer animal model. The systemic toxicity of the nanomedicine was also evaluated during the treatment. Results DOX–GEM prodrug and VCR-loaded NLCs (DOX–GEM VCR NLCs) exhibited the highest antitumor effect in B-cell lymphoma cells and lymphoma animal xenografts when compared with the single drug-loaded NLCs and the drug solutions. Conclusion It could be concluded that the highest antitumor effect can be achieved by the system due to the stable drug-loading capacity, attractive anticancer therapeutic effects, and reduced toxicities in human Burkitt’s lymphoma cell line and mice-bearing cancer model. The resulting DOX–GEM VCR NLCs could be an efficient antilymph cancer agent and could be developed further for the treatment of other tumors.

  16. Formulation of Indomethacin Colon Targeted Delivery Systems Using Polysaccharides as Carriers by Applying Liquisolid Technique

    Directory of Open Access Journals (Sweden)

    Kadria A. Elkhodairy

    2014-01-01

    Full Text Available The present study aimed at the formulation of matrix tablets for colon-specific drug delivery (CSDD system of indomethacin (IDM by applying liquisolid (LS technique. A CSDD system based on time-dependent polymethacrylates and enzyme degradable polysaccharides was established. Eudragit RL 100 (E-RL 100 was employed as time-dependent polymer, whereas bacterial degradable polysaccharides were presented as LS systems loaded with the drug. Indomethacin-loaded LS systems were prepared using different polysaccharides, namely, guar gum (GG, pectin (PEC, and chitosan (CH, as carriers separately or in mixtures of different ratios of 1 : 3, 1 : 1, and 3 : 1. Liquisolid systems that displayed promising results concerning drug release rate in both pH 1.2 and pH 6.8 were compressed into tablets after the addition of the calculated amount of E-RL 100 and lubrication with magnesium stearate and talc in the ratio of 1 : 9. It was found that E-RL 100 improved the flowability and compressibility of all LS formulations. The release data revealed that all formulations succeeded to sustain drug release over a period of 24 hours. Stability study indicated that PEC-based LS system as well as its matrix tablets was stable over the period of storage (one year and could provide a minimum shelf life of two years.

  17. Manipulation of charge carrier injection into organic field-effect transistors by self-assembled monolayers of alkanethiols

    NARCIS (Netherlands)

    Asadi, K.; Gholamrezaie, F.; Smits, E.C.P.; Blom, W.M.; Boer, B. de

    2007-01-01

    Charge carrier injection into two semiconducting polymers is investigated in field-effect transistors using gold source and drain electrodes that are modified by self-assembled monolayers of alkanethiols and perfluorinated alkanethiols. The presence of an interfacial dipole associated with the molec

  18. Engineering functionality gradients by dip coating process in acceleration mode.

    Science.gov (United States)

    Faustini, Marco; Ceratti, Davide R; Louis, Benjamin; Boudot, Mickael; Albouy, Pierre-Antoine; Boissière, Cédric; Grosso, David

    2014-10-08

    In this work, unique functional devices exhibiting controlled gradients of properties are fabricated by dip-coating process in acceleration mode. Through this new approach, thin films with "on-demand" thickness graded profiles at the submillimeter scale are prepared in an easy and versatile way, compatible for large-scale production. The technique is adapted to several relevant materials, including sol-gel dense and mesoporous metal oxides, block copolymers, metal-organic framework colloids, and commercial photoresists. In the first part of the Article, an investigation on the effect of the dip coating speed variation on the thickness profiles is reported together with the critical roles played by the evaporation rate and by the viscosity on the fluid draining-induced film formation. In the second part, dip-coating in acceleration mode is used to induce controlled variation of functionalities by playing on structural, chemical, or dimensional variations in nano- and microsystems. In order to demonstrate the full potentiality and versatility of the technique, original graded functional devices are made including optical interferometry mirrors with bidirectional gradients, one-dimensional photonic crystals with a stop-band gradient, graded microfluidic channels, and wetting gradient to induce droplet motion.

  19. Plasma undulator excited by high-order mode lasers

    Science.gov (United States)

    Wang, Jingwei; Rykovanov, Sergey

    2016-10-01

    A laser-created plasma undulator together with a laser-plasma accelerator makes it possible to construct an economical and extremely compact XFEL. However, the spectrum spread of the radiation from the current plasma undulators is too large for XFELs, because of the different values of strength parameters. The phase slippage between the electrons and the wakefield also limits the number of the electron oscillation cycles, thus reduces the performance of XFEL. Here we proposed a phase-locked plasma undulator created by high-order mode lasers. The modulating field is uniform along the transverse direction by choosing appropriate laser intensities of the modes, which enables all the electrons oscillate with the same strength parameter. The plasma density is tapered to lock the phase between the electrons and the wakefield, which signally increases the oscillation cycles. As a result, X-ray radiation with high brightness and narrow bandwidth is generated by injecting a high-energy electron beam into the novel plasma undulator. The beam loading limit indicates that the current of the electron beam could be hundreds of Ampere. These properties imply that such a plasma undulator may have great potential in compact XFELs. This work was supported by the Helmholtz Association (Young Investigator's Group No. VH-NG-1037).

  20. Instantaneous Respiratory Estimation from Thoracic Impedance by Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Fu-Tai Wang

    2015-07-01

    Full Text Available Impedance plethysmography provides a way to measure respiratory activity by sensing the change of thoracic impedance caused by inspiration and expiration. This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring. The empirical mode decomposition (EMD can decompose a signal into several intrinsic mode functions (IMFs that disclose nonstationary components as well as stationary components and, similarly, capture respiratory episodes from thoracic impedance. However, upper-body movements usually produce motion artifacts that are not easily removed by digital filtering. Moreover, large motion artifacts disable the EMD to decompose respiratory components. In this paper, motion artifacts are detected and replaced by the data mirrored from the prior and the posterior before EMD processing. A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation. Based on the experiments performing a series of static and dynamic physical activates, our results showed the proposed method had higher cross correlations between respiratory frequencies estimated from thoracic impedance and those from oronasal airflow based on small window size compared to the Fourier transform-based method.

  1. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    in Asia and will balance the carrier acquisitions of the United States, the United Kingdom, Russia and India. China’s current military strategy is predominantly defensive, its offensive elements being mainly focused on Taiwan. If China decides to acquire a large carrier with offensive capabilities......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...... catapult with which to launch the fi ghter aircraft, not to mention the possible development of a nuclear power plant for the ship. The Russian press has indicated that China is negotiating to buy SU-33 fi ghters, which Russia uses on the Kuznetsov carrier. The SU-33 is, in its modernized version...

  2. Investigation of field-dependent charge carrier generation and recombination in polymer based solar cells by transient extraction currents

    Energy Technology Data Exchange (ETDEWEB)

    Kniepert, Juliane; Blakesley, James; Neher, Dieter [University of Potsdam (Germany)

    2011-07-01

    There is an ongoing discussion as to whether photoinduced charge transfer in P3HT:PCBM solar cells leads to fully separated electrons and holes, independent of an electric field, or Coulombically bound interfacial charge pairs. While recent studies by R.A. Marsh et al. with transient absorption spectroscopy gave clear evidence for the formation and field-induced dissociation of bound polaron pairs, measurements by I.A. Howard et al. were in favour of hot exciton dissociation. Here, we present the results of bias-dependent Time Delayed Collection Field (TDCF) measurements to access directly the density of free charge carriers in P3HT:PCBM blends coated from dichlorobenzene. Solvent annealing was applied to yield a phase-separated morphology and the corresponding solar cells exhibit high values for the external quantum efficiency and fill factor. Our setup allowed us to follow the generation and recombination of photogenerated charges with a so far unattained time resolution of 40 ns. Our experiments show that the number of collected carriers is independent of the applied bias during pulsed illumination implying that extractable carriers in P3HT:PCBM blends are not generated by the field-assisted separation of bound polaron pairs. In addition, our experiments support the view that bimolecular recombination of free carriers is strongly suppressed in phase-separated P3HT:PBCM blends.

  3. Recycling Gene Carrier with High Efficiency and Low Toxicity Mediated by L-Cystine-Bridged Bis(β-cyclodextrin)s

    Science.gov (United States)

    Zhang, Yu-Hui; Chen, Yong; Zhang, Ying-Ming; Yang, Yang; Chen, Jia-Tong; Liu, Yu

    2014-12-01

    Constructing safe and effective gene delivery carriers is becoming highly desirable for gene therapy. Herein, a series of supramolecular crosslinking system were prepared through host-guest binding of adamantyl-modified low molecular weight of polyethyleneimine with L-cystine-bridged bis(β-cyclodextrin)s and characterized by 1H NMR titration, electron microscopy, zeta potential, dynamic light-scattering, gel electrophoresis, flow cytometry and confocal fluorescence microscopy. The results showed that these nanometersized supramolecular crosslinking systems exhibited higher DNA transfection efficiencies and lower cytotoxicity than the commercial DNA carrier gold standard (25 kDa bPEI) for both normal cells and cancer cells, giving a very high DNA transfection efficiency up to 54% for 293T cells. Significantly, this type of supramolecular crosslinking system possesses a number of enzyme-responsive disulfide bonds, which can be cleaved by reductive enzyme to promote the DNA release but recovered by oxidative enzyme to make the carrier renewable. These results demonstrate that these supramolecular crosslinking systems can be used as promising gene carriers.

  4. First ever ice oil product carrier built by China for foreign shipowner

    Institute of Scientific and Technical Information of China (English)

    Chen Jianan; Chen Hao

    2004-01-01

    @@ As energy supply becomes more and more intense in the world, Russia, whose Baltic regions are abundant of oil, is increasing its oil production and importation. With the prosperity of shipping industry, shipping companies along the Baltic coast increases every year its demand for oil tankers suitable for navigation in their ice sea. In 2004,Guangzhou Shipyard International was awarded a contract for construction of two52000 ton dwt ice oil product carriers. Now detailed design is under way. According to the contract, the two carriers shall be delivered respectively in December 2006 and in May 2007.

  5. Higgs mode excitation in superconductors by intense terahertz pulse

    Science.gov (United States)

    Matsunaga, Ryusuke; Shimano, Ryo

    2016-05-01

    Recent development of intense terahertz (THz) pulse generation technique has offered novel opportunities to reveal ultrafast phenomena in a variety of materials on tabletop experiments and provided a new pathway toward ultrafast control of quantum phases. Here we present our recent study of nonequilibrium dynamics in metallic superconductors NbN excited by intense THz pulse. Since the superconducting gap energy is located in the THz frequency range, the intense THz pulse excitation makes it possible to instantaneously excite high-density quasiparticles at the gap edge without injecting excess energies. It has also become possible to coherently drive the superconducting ground state without exciting incoherent quasiparticles by tuning the pump frequency below the gap energy. The ultrafast dynamics of the order parameter induced by such an intense low energy excitation is directly probed, and the nature of a collective excitation, namely the Higgs amplitude mode, is revealed. Efficient THz higher-harmonic generation from a superconductor is discovered, manifesting the nonlinear coupling between the THz wave and the Higgs mode. We also report the experimental results in a multi-gap superconductor MgB2.

  6. Laser Mode-Dependent Size of Plasma Zones Induced by Femtosecond Laser Pulses in Fused Silica

    Institute of Scientific and Technical Information of China (English)

    TANG Shan-Chun; JIANG Hong-Bing; LIU Yi; GONG Qi-Huang

    2008-01-01

    We carry out the numerical simulations of #emtosecond laser propagation with TEM00 mode, TEM10 mode and a beam combining both the modes in fused silica. It is found that the transverse size of plasma zones induced by laser pulses with the TEM10 mode is smaller than that induced by the TEMoo mode, while the longitudinal size is almost the same, and the saturated plasma density is higher. The transverse size, the longitudinal size and the ratio of the longitudinal to transverse size, for the beam combining both the modes, all could be reduced at the same time in comparison with the TEMoo mode under the same focusing conditions.

  7. Enhanced carrier mobility of multilayer MoS2 thin-film transistors by Al2O3 encapsulation

    Science.gov (United States)

    Kim, Seong Yeoul; Park, Seonyoung; Choi, Woong

    2016-10-01

    We report the effect of Al2O3 encapsulation on the carrier mobility and contact resistance of multilayer MoS2 thin-film transistors by statistically investigating 70 devices with SiO2 bottom-gate dielectric. After Al2O3 encapsulation by atomic layer deposition, calculation based on Y-function method indicates that the enhancement of carrier mobility from 24.3 cm2 V-1 s-1 to 41.2 cm2 V-1 s-1 occurs independently from the reduction of contact resistance from 276 kΩ.μm to 118 kΩ.μm. Furthermore, contrary to the previous literature, we observe a negligible effect of thermal annealing on contact resistance and carrier mobility during the atomic layer deposition of Al2O3. These results demonstrate that Al2O3 encapsulation is a useful method of improving the carrier mobility of multilayer MoS2 transistors, providing important implications on the application of MoS2 and other two-dimensional materials into high-performance transistors.

  8. Hot carrier injection degradation under dynamic stress

    Institute of Scientific and Technical Information of China (English)

    Ma Xiao-Hua; Cao Yan-Rong; Hao Yue; Zhang Yue

    2011-01-01

    In this paper, we have studied hot carrier injection (HCI) under alternant stress. Under different stress modes, different degradations are obtained from the experiment results. The different alternate stresses can reduce or enhance the HC effect, which mainly depends on the latter condition of the stress cycle. In the stress mode A (DC stress with electron injection), the degradation keeps increasing. In the stress modes B (DC stress and then stress with the smallest gate injection) and C (DC stress and then stress with hole injection under Vg=0V and Vd = 1.8 V), recovery appears in the second stress period. And in the stress mode D (DC stress and then stress with hole injection under Vg = -1.8 V and Vd = 1.8 V), as the traps filled in by holes can be smaller or greater than the generated interface states, the continued degradation or recovery in different stress periods can be obtained.

  9. Improved cytotoxicity of paclitaxel loaded in nanosized lipid carriers by intracellular delivery

    Science.gov (United States)

    Miao, Jing; Du, Yongzhong; Yuan, Hong; Zhang, Xingguo; Li, Qian; Rao, Yuefeng; Zhao, Mengdan; Hu, Fuqiang

    2015-01-01

    Nanosized lipid carriers (NLC) can improve the limited drug-loading (DL) capacity and drug expulsion during storage, and adjust the drug release profile of solid lipid nanoparticles (SLN). In this study, Paclitaxel (PTX)-loaded NLC were prepared by solvent diffusion method using monostearin as solid lipid and oleic acid (OA) as liquid lipid matrix. The blank NLC with different OA content (the size range was from 89.5 ± 7.4 to 160.2 ± 34.6 nm) showed smaller size than the blank SLN (the size was 272.7 ± 43.6 nm), while the PTX-loaded NLC (the size range was from 481.3 ± 29.8 to 561.7 ± 38.3 nm) showed little bigger size, higher DL capacity, and faster drug in vitro release rate comparing with SLN (the size was 437.3 ± 68.2 nm). The 50 % cellular growth inhibitions (IC50) of PTX-loaded NLC with 0, 5, 10, and 20 wt % OA were 0.92 ± 0.06, 0.69 ± 0.04, 0.25 ± 0.02, and 0.12 ± 0.02 µg mL-1, respectively, while the IC50 of TaxolTM was 1.72 ± 0.09 µg mL-1. For analyzing cellular drug effect, cellular uptakes of fluorescent NLC and intracellular drug concentration were investigated. As the incorporation of OA into solid lipid matrix could accelerate both the cellular uptake and the PTX delivery, loaded by NLC, the cytotoxicity of PTX could be enhanced, and further enhanced by increasing OA content in NLC.

  10. 14 CFR 249.20 - Preservation of records by certificated air carriers.

    Science.gov (United States)

    2010-01-01

    ... to explain, journal entries; entry numbers Do. 3. Voucher distribution registers or their equivalent... pilots' flight logs and passenger lists relevant to a determination of the validity of a carrier's...' reports; records of receipts and disbursements including bank statements, check registers and...

  11. Polaron hopping mediated by nuclear tunnelling in semiconducting polymers at high carrier density

    NARCIS (Netherlands)

    Asadi, Kamal; Kronemeijer, Auke J.; Cramer, Tobias; Koster, L. Jan Anton; Blom, Paul W. M.; de Leeuw, Dago M.

    2013-01-01

    The transition rate for a single hop of a charge carrier in a semiconducting polymer is assumed to be thermally activated. As the temperature approaches absolute zero, the predicted conductivity becomes infinitesimal in contrast to the measured finite conductivity. Here we present a uniform descript

  12. Discovery of superconductivity in KTaO₃ by electrostatic carrier doping.

    Science.gov (United States)

    Ueno, K; Nakamura, S; Shimotani, H; Yuan, H T; Kimura, N; Nojima, T; Aoki, H; Iwasa, Y; Kawasaki, M

    2011-05-22

    Superconductivity at interfaces has been investigated since the first demonstration of electric-field-tunable superconductivity in ultrathin films in 1960(1). So far, research on interface superconductivity has focused on materials that are known to be superconductors in bulk. Here, we show that electrostatic carrier doping can induce superconductivity in KTaO(3), a material in which superconductivity has not been observed before. Taking advantage of the large capacitance of the self-organized electric double layer that forms at the interface between an ionic liquid and KTaO(3) (ref. 12), we achieve a charge carrier density that is an order of magnitude larger than the density that can be achieved with conventional chemical doping. Superconductivity emerges in KTaO(3) at 50 mK for two-dimensional carrier densities in the range 2.3 × 10(14) to 3.7 × 10(14) cm(-2). The present result clearly shows that electrostatic carrier doping can lead to new states of matter at nanoscale interfaces.

  13. Lasing mode regulation and single-mode realization in ZnO whispering gallery microcavities by the Vernier effect.

    Science.gov (United States)

    Wang, Y Y; Xu, C X; Jiang, M M; Li, J T; Dai, J; Lu, J F; Li, P L

    2016-10-07

    The wide direct bandgap and strong exciton binding energy of ZnO have inspired examinations of ultraviolet lasing over the previous decades. However, regulation of the lasing mode, especially the realization of single mode lasing, is still a challenge. In this study, a ZnO comb-like structure with an array of microrods was selected to design coupled whispering-gallery-mode cavities, wherein the naturally varied air-gap between the adjacent microrods created a flexible condition for optical field coupling without any complicated micromanipulation. Spectral behaviour of lasing and coupling interaction between coupled ZnO microrods were systematically investigated. By regulating the nano-scale inter-space of dual coupled microrods, stable single-mode lasing with a higher Q factor and lower threshold was obtained successfully based on the Vernier effect. The formation conditions and the mechanism of single-mode lasing derived from the coupled ZnO microrods were discussed in detail. It also demonstrated an approach to construct high quality single-mode lasing by tuning the diameters of the coupled ZnO microrods.

  14. Immune Thrombocytopenia Resolved by Eltrombopag in a Carrier of Glucose-6-Phosphate Dehydrogenase Deficiency

    Directory of Open Access Journals (Sweden)

    Laura Scaramucci

    2016-03-01

    Full Text Available Eltrombopag, a thrombopoietin mimetic peptide, may provide excellent clinical efficacy in steroid-refractory patients with immune thrombocytopenic purpura (ITP [1,2]. Eltrombopag is generally well tolerated. However, its use in the particular setting of glucose-6-phosphate dehydrogenase (G6PD and history of acute hemolytic anemia (AHA has not been reported so far. A 51-year-old female was diagnosed as having ITP in September 2014. She was not taking any medication and her past history was negative, apart from having been diagnosed a carrier (heterozygous of G6PD deficiency (Mediterranean variant after a familial screening by molecular and biochemical methods. She presented with only slightly reduced (about 50% enzyme level, belonging to World Health Organization-defined class 3 [3,4]. In the following years, the patient experienced some episodes of AHA, which were managed at outside institutions; in particular, a severe episode of AHA, probably triggered by urinary infection and antibiotics [5], had complicated her second and last delivery. The hemolytic episodes were selflimiting and resolved without sequelae. No other causes of hemolysis were documented. When the case came to our attention, a diagnosis of ITP was made; hemolytic parameters were normal, although the G6PD enzyme concentration was not measured. Oral prednisone (1 mg/kg was given with only a transient benefit. The patient was then a candidate for elective splenectomy. However, given her extremely low platelet count, she was started in October 2014 on eltrombopag at 50 mg/day as a bridge to splenectomy. Given that, to the best of our knowledge, the use of this drug has never been reported in the particular setting of G6PD deficiency, the patient was constantly monitored. A prompt platelet increase (178x109/L was observed 1 week after the start of treatment. After she achieved the target platelet count, the dose of eltrombopag was tapered to the lowest effective dose. The patient

  15. MODAL ANALYSIS OF CARRIER SYSTEM FOR HEAVY HORIZONTAL MULTIFUNCTION MACHINING CENTER BY FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2014-01-01

    Full Text Available The aim of the paper is to reveal and analyze resonance modes of a large-scale milling-drilling-boring machine. The machine has a movable column with vertical slot occupied by a symmetrical carriage with horizontal ram. Static rigidity of the machine is relatively low due to its large dimensions. So it is necessary to assess possible vibration activity. Virtual and operational trials of the machine have been carried out simultaneously. Modeling has been executed with the help of a finite element method (FEM. The FEM-model takes into account not only rigidity of machine structures but also flexibility of bearings, feed drive systems and guides. Modal FEM-analysis has revealed eight resonance modes that embrace the whole machine tool. They form a frequency interval from 12 to 75 Hz which is undesirable for machining. Three closely located resonances (31-37 Hz are considered as the most dangerous ones. They represent various combinations of three simple motions: vertical oscillations of a carriage, horizontal vibrations of a ram and column torsion. Reliability of FEM- estimations has been proved by in-situ vibration measurements.An effect for stabilization of resonance modes has been detected while making variations in design parameters of the machine tool. For example, a virtual replacement of cast iron for steel in machine structures practically does not have any effect on resonance frequencies. Rigidity increase in some parts (e.g. a ram has also a small effect on a resonance pattern. On the other hand, resonance stability makes it possible to avoid them while selecting a spindle rotation frequency.It is recommended to set double feed drives for all axes. A pair of vertical screws prevents a “pecking” resonance of the carriage at frequency of 54 Hz. It is necessary to foresee an operation of a main drive of such heavy machine tool in the above resonance interval with the spindle frequency of more than 75 Hz. For this purpose it is necessary

  16. Inactivation of Listeria monocytogenes by disinfectants and bacteriophages in suspension and stainless steel carrier tests.

    Science.gov (United States)

    Chaitiemwong, N; Hazeleger, W C; Beumer, R R

    2014-12-01

    To simulate food contact surfaces with pits or cracks, stainless steel plates with grooves (depths between 0.2 and 5 mm) were constructed. These plates were artificially contaminated with Listeria monocytogenes in clean conditions, with organic soiling, or after 14 days of biofilm formation after which inactivation of the pathogen by Suma Tab D4 (sodium dichloroisocyanurate, 240 and 300 mg/liter), Suma Bac D10 (quaternary ammonium compound, 740 mg/liter), and bacteriophage suspension (Listex P100) was determined. Both chemical disinfectants performed well in suspension tests and in clean carrier tests according to the European standard with a reduction of more than 5 and 4 log units, respectively, of Listeria cells after 5 min of contact time. However, for the plates with grooves, the reduction could not meet the standard requirement, although a higher reduction of L. monocytogenes was observed in the shallow grooves compared with the deeper grooves. Furthermore, presence of food residues and biofilm reduced the effect of the disinfectants especially in the deep grooves, which was dependent on type of food substrate. Bacteriophages showed the best antimicrobial effect compared with the chemical disinfectants (sodium dichloroisocyanurate and quaternary ammonium compound) in most cases in the shallow grooves, but not in the deep grooves. The chlorine based disinfectants were usually less effective than quaternary ammonium compound. The results clearly demonstrate that surfaces with grooves influenced the antimicrobial effect of the chemical disinfectants and bacteriophages because the pathogen is protected in the deep grooves. The use of bacteriophages to inactivate pathogens on surfaces could be helpful in limited cases; however, use of large quantities in practice may be costly and phage-resistant strains may develop.

  17. The switching mechanism of the mitochondrial ADP/ATP carrier explored by free-energy landscapes.

    Science.gov (United States)

    Pietropaolo, Adriana; Pierri, Ciro Leonardo; Palmieri, Ferdinando; Klingenberg, Martin

    2016-06-01

    The ADP/ATP carrier (AAC) of mitochondria has been an early example for elucidating the transport mechanism alternating between the external (c-) and internal (m-) states (M. Klingenberg, Biochim. Biophys. Acta 1778 (2008) 1978-2021). An atomic resolution crystal structure of AAC is available only for the c-state featuring a three repeat transmembrane domain structure. Modeling of transport mechanism remained hypothetical for want of an atomic structure of the m-state. Previous molecular dynamics studies simulated the binding of ADP or ATP to the AAC remaining in the c-state. Here, a full description of the AAC switching from the c- to the m-state is reported using well-tempered metadynamics simulations. Free-energy landscapes of the entire translocation from the c- to the m-state, based on the gyration radii of the c- and m-gates and of the center of mass, were generated. The simulations revealed three free-energy basins attributed to the c-, intermediate- and m-states separated by activation barriers. These simulations were performed with the empty and with the ADP- and ATP-loaded AAC as well as with the poorly transported AMP and guanine nucleotides, showing in the free energy landscapes that ADP and ATP lowered the activation free-energy barriers more than the other substrates. Upon binding AMP and guanine nucleotides a deeper free-energy level stabilized the intermediate-state of the AAC2 hampering the transition to the m-state. The structures of the substrate binding sites in the different states are described producing a full picture of the translocation events in the AAC.

  18. Intrinsic rotation drive by collisionless trapped electron mode turbulence

    CERN Document Server

    Wang, Lu; Diamond, P H

    2016-01-01

    Both the parallel residual stress and parallel turbulent acceleration driven by electrostatic collisionsless trapped electron mode (CTEM) turbulence are calculated analytically using gyrokinetic theory. Quasilinear results show that the parallel residual stress contributes an outward flux of co-current rotation for normal magnetic shear and turbulence intensity profile increasing outward. This may induce intrinsic counter-current rotation or flattening of the co-current rotation profile. The parallel turbulent acceleration driven by CTEM turbulence vanishes, due to the absence of a phase shift between density fluctuation and ion pressure fluctuation. This is different from the case of ion temperature gradient (ITG) turbulence, for which the turbulent acceleration can provide co-current drive for normal magnetic shear and turbulence intensity profile increasing outward. Its order of magnitude is predicted to be the same as that of the divergence of the residual stress [Lu Wang and P.H. Diamond, Phys. Rev. Lett...

  19. Superresolution measurement of nanofiber diameter by modes beating

    Science.gov (United States)

    Fenton, E. F.; Solano, P.; Hoffman, J. E.; Orozco, L. A.; Rolston, S. L.; Fatemi, F. K.

    2016-05-01

    Nanofibers are becoming an important tool in quantum information technologies for coupling photonics systems to atomic systems. Nondestructive techniques for characterizing these nanofibers prior to integration into an apparatus are desirable. In this work, we probe the light propagating in a fused silica optical nanofiber (750-nm-diameter) by coupling it evanescently to a 6- μm-diameter microfiber that is scanned along the nanofiber length. This technique is capable of observing all possible beat lengths among different propagating modes. The beat lengths are strongly dependent on the nanofiber diameter and refractive index of the fiber. The steep dependence has enabled measurements of the fiber diameter with sub-Angstrom sensitivity. The diameter extracted from the beat length measurements agrees with a measurement made using scanning electron microscopy. Work supported by NSF.

  20. Carrier profiling in Si-implanted gallium nitride by Scanning Capacitance Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lamhamdi, M., E-mail: mohamed.lamhamdi@gmail.com [Universite Francois Rabelais de Tours, Laboratoire de Microelectronique de Puissance, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Cayrel, F. [Universite Francois Rabelais de Tours, Laboratoire de Microelectronique de Puissance, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Bazin, A.E. [Universite Francois Rabelais de Tours, Laboratoire de Microelectronique de Puissance, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); STMicroelectronics, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Collard, E. [STMicroelectronics, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Alquier, D. [Universite Francois Rabelais de Tours, Laboratoire de Microelectronique de Puissance, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France)

    2012-03-15

    To face silicon limits, gallium nitride (GaN) exhibits major interests for optoelectronics and power electronic devices. Nevertheless, several challenges have to be overcome, with local doping by ion implantation as a major one. It requires development of reliable characterization tools able to provide electrical information with nanoscale resolution. In this work, Atomic Force Microscopy (AFM) combined to its Scanning Capacitance Microscopy (SCM) mode was used for surface damages quantification and nanoscale dopant profiling. GaN samples have been implanted with Si in order to obtain a box-like profile and annealed above 1000 Degree-Sign C under nitrogen with AlN protective cap layer. SCM measurements have led to reliable and quantitative dopant electrical activity measurements thank to calibration sample. Moreover, a good agreement, in terms of depth and shape, has been obtained between SCM and SIMS profiles. This work has evidenced that a high activation rate of implanted Si can be achieved using rapid thermal annealing.

  1. Accelerated start-up of moving bed biofilm reactor by using a novel suspended carrier with porous surface.

    Science.gov (United States)

    Chen, Xin; Kong, Lingjun; Wang, Xingyu; Tian, Shuanghong; Xiong, Ya

    2015-02-01

    A novel suspended carrier with porous surface was firstly prepared by coating a sponge on the inside and outside of a hard polyethylene ring. Herein the effects of the sponge thickness (0, 2, 4, 6 mm) and pore size (17, 45, 85 pores per inch, ppi) on the performance of the start-up stage in moving bed biofilm reactor (MBBR) were investigated. The results indicated that the home-made carrier with the sponge thickness of 4 mm and the pore size of 45 ppi, defined as SC4-45, showed the best performance, which obtained high biomass concentration of 2,136.6 mg/L, oxygen uptake rate for COD of 150.1 mg O2/h and oxygen uptake rate for NH4(+)-N of 17.4 mg O2/h. The DGGE profiles of the biofilms obtained in SC4-45 and a commercial carrier showed a similar community as the Dice similarity coefficients between two samples was 0.72. Furthermore, 16S rRNA gene sequence analysis reveals dominance of Sphaerotilus sp. and Aeromonas sp. in the community of both samples. Moreover, for the MBBR based on SC4-45, COD and NH4(+)-N removal rates reached 99.5 ± 1.1 and 93.6 ± 2.3 % at the end of the start-up stage, much higher than those of the commercial carrier, 74.9 ± 2.7 and 40.0 ± 1.8 %, respectively. These indicated the novel carrier obtained a quick start-up.

  2. Hyaluronan microgel as a potential carrier for protein sustained delivery by tailoring the crosslink network

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chunhong [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Zhao, Jianhao, E-mail: jhzhao@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Tu, Mei; Zeng, Rong; Rong, Jianhua [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2014-03-01

    Hyaluronan (HA) microgels with different crosslink network, i.e. HGPs-1, HGPs-1.5, HGPs-3, HGPs-6 and HGPs-15, were synthesized using divinyl sulfone (DVS) as the crosslinker in an inverse microemulsion system for controlling the sustained delivery of bovine serum albumin (BSA). With increasing the crosslinker content, the average particle size slightly increased from 1.9 ± 0.3 μm to 3.6 ± 0.5 μm by dynamic laser scattering analysis. However, the crosslinker content had no significant effect on the morphology of HA microgels by scanning and transmission electron microscopes. Fourier transform infrared spectroscopy and elemental analysis proved more sulfur participated in the crosslink reaction when raising the crosslinker amount. The water swelling test confirmed the increasing crosslink density with the crosslinker content by calculating the average molecular weight between two crosslink points to be 8.25 ± 2.51 × 10{sup 5}, 1.26 ± 0.43 × 10{sup 5}, 0.96 ± 0.09 × 10{sup 5}, 0.64 ± 0.03 × 10{sup 5}, and 0.11 ± 0.01 × 10{sup 5} respectively. The degradation of HA microgels by hyaluronidase slowed down by enhancing the crosslink density, only about 5% of HGPs-15 was degraded as opposed to over 90% for HGPs-1. BSA loading had no obvious influence on the surface morphology of HA microgels but seemed to induce their aggregation. The increase of crosslink density decreased the BSA loading capacity but facilitated its long-term sustained delivery. When the molar ratio of DVS to repeating unit of HA reached 3 or higher, similar delivery profiles were obtained. Among all these HA microgels, HGPs-3 was the optimal carrier for BSA sustained delivery in this system because it possessed both high BSA loading capacity and long-term delivery profile simultaneously. - Highlights: • HA microgels with different crosslink densities were prepared. • The crosslinker content had little effect on the morphology and size of HA microgels. • The crosslink density

  3. Asymmetric excitation of surface plasmons by dark mode coupling

    KAUST Repository

    Zhang, X.

    2016-02-19

    Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

  4. Asymmetric excitation of surface plasmons by dark mode coupling.

    Science.gov (United States)

    Zhang, Xueqian; Xu, Quan; Li, Quan; Xu, Yuehong; Gu, Jianqiang; Tian, Zhen; Ouyang, Chunmei; Liu, Yongmin; Zhang, Shuang; Zhang, Xixiang; Han, Jiaguang; Zhang, Weili

    2016-02-01

    Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

  5. Characterizing delamination of fibre composites by mixed mode cohesive laws

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Jacobsen, Torben K.

    2009-01-01

    A novel method is used for the determination of mixed mode cohesive laws and bridging laws for the characterisation of crack bridging in composites. The approach is based on an application of the J integral. The obtained cohesive laws were found to possess high peak stress values. Mixed mode...

  6. Optimization of Sour Cherry Juice Spray Drying as
Affected by Carrier Material and Temperature

    Science.gov (United States)

    Zorić, Zoran; Pedisić, Sandra; Dragović-Uzelac, Verica

    2016-01-01

    Summary Response surface methodology was applied for optimization of the sour cherry Marasca juice spray drying process with 20, 30 and 40% of carriers maltodextrin with dextrose equivalent (DE) value of 4–7 and 13–17 and gum arabic, at three drying temperatures: 150, 175 and 200 °C. Increase in carrier mass per volume ratio resulted in lower moisture content and powder hygroscopicity, higher bulk density, solubility and product yield. Higher temperatures decreased the moisture content and bulk density of powders. Temperature of 200 °C and 27% of maltodextrin with 4–7 DE were found to be the most suitable for production of sour cherry Marasca powder. PMID:28115901

  7. Regulation of electron temperature gradient turbulence by zonal flows driven by trapped electron modes

    Energy Technology Data Exchange (ETDEWEB)

    Asahi, Y., E-mail: y.asahi@nr.titech.ac.jp; Tsutsui, H.; Tsuji-Iio, S. [Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ishizawa, A.; Watanabe, T.-H. [National Institute for Fusion Science, Gifu 509-5292 (Japan)

    2014-05-15

    Turbulent transport caused by electron temperature gradient (ETG) modes was investigated by means of gyrokinetic simulations. It was found that the ETG turbulence can be regulated by meso-scale zonal flows driven by trapped electron modes (TEMs), which are excited with much smaller growth rates than those of ETG modes. The zonal flows of which radial wavelengths are in between the ion and the electron banana widths are not shielded by trapped ions nor electrons, and hence they are effectively driven by the TEMs. It was also shown that an E × B shearing rate of the TEM-driven zonal flows is larger than or comparable to the growth rates of long-wavelength ETG modes and TEMs, which make a main contribution to the turbulent transport before excitation of the zonal flows.

  8. Switching the mode of sucrose utilization by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Miletti Luiz C

    2008-02-01

    Full Text Available Abstract Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by

  9. Measuring long-range carrier diffusion across multiple grains in polycrystalline semiconductors by photoluminescence imaging

    OpenAIRE

    K. Alberi; Fluegel, B.; Moutinho, H.; Dhere, R. G.; Li, J. V.; Mascarenhas, A

    2013-01-01

    Thin-film polycrystalline semiconductors are currently at the forefront of inexpensive large-area solar cell and integrated circuit technologies because of their reduced processing and substrate selection constraints. Understanding the extent to which structural and electronic defects influence carrier transport in these materials is critical to controlling the optoelectronic properties, yet many measurement techniques are only capable of indirectly probing their effects. Here we apply a nove...

  10. Effect of free-carrier concentration and optical injection on carrier lifetimes in undoped and iodine doped CdMgTe/CdSeTe double heterostructures grown by molecular beam epitaxy

    Science.gov (United States)

    Sohal, S.; Edirisooriya, M.; Ogedengbe, O. S.; Petersen, J. E.; Swartz, C. H.; LeBlanc, E. G.; Myers, T. H.; Li, J. V.; Holtz, M.

    2016-12-01

    Time-resolved and time integrated photoluminescence (PL) studies are reported for undoped and doped CdMgTe/CdSeTe double heterostructures (DHs) grown by molecular beam epitaxy. Undoped DHs are studied with absorber layer thickness varying from 0.5 to 2.5 µm. The n-type free-carrier concentration is varied ~7  ×  1015, 8.4  ×  1016, and 8.4  ×  1017 cm-3 using iodine as a dopant in different absorber layer thicknesses (0.25-2.0 µm). Optical injection is varied from 1  ×  1010 to 3  ×  1011 photons/pulse/cm2, corresponding to the initial injection of photo-carriers up to ~8  ×  1015 cm-3, to examine the effects of excess carrier concentration on the PL lifetimes. Undoped DHs exhibit an initial rapid decay followed by a slower dependence with carrier lifetimes up to ~485 ns. The dependence of carrier lifetimes on the thickness of the absorber layers (0.5-2.5 µm) suggests interface recombination velocities ({{v}\\operatorname{int}}~ ) ~ 1288 and 238 cm s-1 in the initial and later decay times, respectively, corresponding to high and low photo-carrier concentrations. The Shockley-Read-Hall model is used to describe the results in which variations are observed in {{v}\\operatorname{int}}~ for undoped DHs. The lifetimes of doped DHs show a consistent trend with thickness. The {{v}\\operatorname{int}}~ ~ 80-200 cm s-1 is estimated for doping n ~ 7  ×  1015 cm-3 and 240-410 cm s-1 for n ~ 8.4  ×  1016 cm-3. The observed decrease in carrier lifetimes with increasing n is consistent with growing importance of the radiative recombination rate due to the excess carrier concentration. The effect of carrier concentration on the PL spectrum is also discussed.

  11. Improved cytotoxicity of paclitaxel loaded in nanosized lipid carriers by intracellular delivery

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Jing, E-mail: joemj1005@163.com, E-mail: miaojing@zju.edu.cn [Zhejiang University, Department of Pharmacy, the First Affiliated Hospital, College of Medicine (China); Du, Yongzhong; Yuan, Hong [Zhejiang University, College of Pharmaceutical Sciences (China); Zhang, Xingguo; Li, Qian; Rao, Yuefeng [Zhejiang University, Department of Pharmacy, the First Affiliated Hospital, College of Medicine (China); Zhao, Mengdan [Zhejiang University, Women’s Hospital, College of Medicine (China); Hu, Fuqiang, E-mail: hufq@zju.edu.cn [Zhejiang University, College of Pharmaceutical Sciences (China)

    2015-01-15

    Nanosized lipid carriers (NLC) can improve the limited drug-loading (DL) capacity and drug expulsion during storage, and adjust the drug release profile of solid lipid nanoparticles (SLN). In this study, Paclitaxel (PTX)-loaded NLC were prepared by solvent diffusion method using monostearin as solid lipid and oleic acid (OA) as liquid lipid matrix. The blank NLC with different OA content (the size range was from 89.5 ± 7.4 to 160.2 ± 34.6 nm) showed smaller size than the blank SLN (the size was 272.7 ± 43.6 nm), while the PTX-loaded NLC (the size range was from 481.3 ± 29.8 to 561.7 ± 38.3 nm) showed little bigger size, higher DL capacity, and faster drug in vitro release rate comparing with SLN (the size was 437.3 ± 68.2 nm). The 50 % cellular growth inhibitions (IC{sub 50}) of PTX-loaded NLC with 0, 5, 10, and 20 wt % OA were 0.92 ± 0.06, 0.69 ± 0.04, 0.25 ± 0.02, and 0.12 ± 0.02 µg mL{sup −1}, respectively, while the IC{sub 50} of Taxol{sup TM} was 1.72 ± 0.09 µg mL{sup −1}. For analyzing cellular drug effect, cellular uptakes of fluorescent NLC and intracellular drug concentration were investigated. As the incorporation of OA into solid lipid matrix could accelerate both the cellular uptake and the PTX delivery, loaded by NLC, the cytotoxicity of PTX could be enhanced, and further enhanced by increasing OA content in NLC.

  12. Analysis of thermoelectric properties of amorphous InGaZnO thin film by controlling carrier concentration

    Directory of Open Access Journals (Sweden)

    Yuta Fujimoto

    2015-09-01

    Full Text Available We have investigated the thermoelectric properties of amorphous InGaZnO (a-IGZO thin films optimized by adjusting the carrier concentration. The a-IGZO films were produced under various oxygen flow ratios. The Seebeck coefficient and the electrical conductivity were measured from 100 to 400 K. We found that the power factor (PF at 300 K had a maximum value of 82 × 10−6 W/mK2, where the carrier density was 7.7 × 1019 cm−3. Moreover, the obtained data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level was located approximately above the potential barrier when the PF became maximal. The thermoelectric properties were controlled by the relationship between the position of Fermi level and the height of potential energy barriers.

  13. Study on diffusion and recombination of minority carriers by the method of photoconductive decay

    Science.gov (United States)

    Chow, R. H.

    1984-09-01

    This paper describes an experiment relating to the diffusion of charge carriers in homogeneous semiconductor material. Diffusion theory, as outlined in this paper, is applied to deduce from measurements a quantity called the bulk lifetime of excess minority carriers: a quantity which is independent of the size, shape, and surface condition of the semiconductor sample. Because of this independence, the bulk lifetime is used as one of the characterizing quantities of semiconductor material. In performing this experiment, the student will gain a working knowledge of diffusion theory as applied to semiconductor carriers, and at the same time become acquainted with an important technique for the characterization of semiconductor material. The actual duration of involvement will depend upon the amount of setting up of equipment, sample preparation, etc., that is expected of the student. An oscilloscope of fast rise time (200-MHz bandwidth), and a xenon flash tube with pulse duration of a few microseconds (General Radio 1542-B electronic stroboscope is a proven possibility), are the major items of equipment needed.

  14. Extended carrier lifetimes and diffusion in hybrid perovskites revealed by Hall effect and photoconductivity measurements

    Science.gov (United States)

    Chen, Y.; Yi, H. T.; Wu, X.; Haroldson, R.; Gartstein, Y. N.; Rodionov, Y. I.; Tikhonov, K. S.; Zakhidov, A.; Zhu, X.-Y.; Podzorov, V.

    2016-08-01

    Impressive performance of hybrid perovskite solar cells reported in recent years still awaits a comprehensive understanding of its microscopic origins. In this work, the intrinsic Hall mobility and photocarrier recombination coefficient are directly measured in these materials in steady-state transport studies. The results show that electron-hole recombination and carrier trapping rates in hybrid perovskites are very low. The bimolecular recombination coefficient (10-11 to 10-10 cm3 s-1) is found to be on par with that in the best direct-band inorganic semiconductors, even though the intrinsic Hall mobility in hybrid perovskites is considerably lower (up to 60 cm2 V-1 s-1). Measured here, steady-state carrier lifetimes (of up to 3 ms) and diffusion lengths (as long as 650 μm) are significantly longer than those in high-purity crystalline inorganic semiconductors. We suggest that these experimental findings are consistent with the polaronic nature of charge carriers, resulting from an interaction of charges with methylammonium dipoles.

  15. Quantitative vibro-acoustography of tissue-like objects by measurement of resonant modes

    Science.gov (United States)

    Mazumder, Dibbyan; Umesh, Sharath; Mohan Vasu, Ram; Roy, Debasish; Kanhirodan, Rajan; Asokan, Sundarrajan

    2017-01-01

    We demonstrate a simple and computationally efficient method to recover the shear modulus pertaining to the focal volume of an ultrasound transducer from the measured vibro-acoustic spectral peaks. A model that explains the transport of local deformation information with the acoustic wave acting as a carrier is put forth. It is also shown that the peaks correspond to the natural frequencies of vibration of the focal volume, which may be readily computed by solving an eigenvalue problem associated with the vibrating region. Having measured the first natural frequency with a fibre Bragg grating sensor, and armed with an expedient means of computing the same, we demonstrate a simple procedure, based on the method of bisection, to recover the average shear modulus of the object in the ultrasound focal volume. We demonstrate this recovery for four homogeneous agarose slabs of different stiffness and verify the accuracy of the recovery using independent rheometer-based measurements. Extension of the method to anisotropic samples through the measurement of a more complete set of resonant modes and the recovery of an elasticity tensor distribution, as is done in resonant ultrasound spectroscopy, is suggested.

  16. Study on the drift mobility of carriers in vitreous Se thin film by the voltage-pulse injection

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.J.; Kim, I.H.; Choi, K.W.; Choi, C.K. (Gyeonsang National Univ., Jinju (Republic of Korea))

    1982-05-01

    The drift mobility of carriers in the vitreous Se thin films were measured by the Haynes-Schokley method. It had been shown that the hole mobility was about 0.83 cm/sup 3//V-sec and the drift velocity showed no time dependence. It had also been shown that the value of Pool-Frenkel parameter was approximately 2 from the I-V curve.

  17. Fission of SNX-BAR-coated endosomal retrograde transport carriers is promoted by the dynamin-related protein Vps1.

    Science.gov (United States)

    Chi, Richard J; Liu, Jingxuan; West, Matthew; Wang, Jing; Odorizzi, Greg; Burd, Christopher G

    2014-03-03

    Retromer is an endosomal sorting device that orchestrates capture and packaging of cargo into transport carriers coated with sorting nexin BAR domain proteins (SNX-BARs). We report that fission of retromer SNX-BAR-coated tubules from yeast endosomes is promoted by Vps1, a dynamin-related protein that localizes to endosomes decorated by retromer SNX-BARs and Mvp1, a SNX-BAR that is homologous to human SNX8. Mvp1 exhibits potent membrane remodeling activity in vitro, and it promotes association of Vps1 with the endosome in vivo. Retrograde transport carriers bud from the endosome coated by retromer and Mvp1, and cargo export is deficient in mvp1- and vps1-null cells, but with distinct endpoints; cargo export is delayed in mvp1-null cells, but cargo export completely fails in vps1-null cells. The results indicate that Mvp1 promotes Vps1-mediated fission of retromer- and Mvp1-coated tubules that bud from the endosome, revealing a functional link between the endosomal sorting and fission machineries to produce retrograde transport carriers.

  18. Investigation of dominant spin wave modes by domain walls collision

    Energy Technology Data Exchange (ETDEWEB)

    Ramu, M.; Purnama, I.; Goolaup, S.; Chandra Sekhar, M.; Lew, W. S., E-mail: wensiang@ntu.edu.sg [School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)

    2014-06-28

    Spin wave emission due to field-driven domain wall (DW) collision has been investigated numerically and analytically in permalloy nanowires. The spin wave modes generated are diagonally symmetric with respect to the collision point. The non-propagating mode has the highest amplitude along the middle of the width. The frequency of this mode is strongly correlated to the nanowire geometrical dimensions and is independent of the strength of applied field within the range of 0.1 mT to 1 mT. For nanowire with film thickness below 5 nm, a second spin wave harmonic mode is observed. The decay coefficient of the spin wave power suggests that the DWs in a memory device should be at least 300 nm apart for them to be free of interference from the spin waves.

  19. Comprehensive study of CD compensation and carrier phase estimation in optical communication systems influenced by equalization enhanced phase noise

    CERN Document Server

    Xu, Tianhua; Popov, Sergei; Li, Jie; Sergeyev, Sergey; Friberg, Ari T; Liu, Tiegen; Zhang, Yimo

    2016-01-01

    The performance of long-haul coherent optical fiber transmission system is significantly affected by the equalization enhanced phase noise (EEPN), due to the interaction between the electronic dispersion compensation (EDC) and the laser phase noise. In this paper, we present a comprehensive study on different chromatic dispersion (CD) compensation and carrier phase recovery (CPR) approaches, in the n-level phase shift keying (n-PSK) and the n-level quadrature amplitude modulation (n-QAM) coherent optical transmission systems, considering the impacts of EEPN. Four CD compensation methods are considered: the time-domain equalization (TDE), the frequency-domain equalization (FDE), the least mean square (LMS) adaptive equalization are applied for EDC, and the dispersion compensating fiber (DCF) is employed for optical dispersion compensation (ODC). Meanwhile, three carrier phase recovery methods are also involved: a one-tap normalized least mean square (NLMS) algorithm, a block-wise average (BWA) algorithm, and a...

  20. Development of in situ diagnostics and tools handled by a light multipurpose carrier for tokamak in-vessel interventions

    Energy Technology Data Exchange (ETDEWEB)

    Houry, M., E-mail: michael.houry@cea.f [CEA, Institut de Recherche sur la Fusion par confinement Magnetique, F-13108 Saint-Paul-Lez-Durance (France); Bayetti, P. [CEA, Institut de Recherche sur la Fusion par confinement Magnetique, F-13108 Saint-Paul-Lez-Durance (France); Keller, D. [CEA, LIST, Service de Robotique Interactive, 18 route du Panorama, BP6, F-92265 Fontenay-aux-Roses (France); Gargiulo, L.; Bruno, V.; Hatchressian, J.C.; Hernandez, C.; Martins, J.P. [CEA, Institut de Recherche sur la Fusion par confinement Magnetique, F-13108 Saint-Paul-Lez-Durance (France); Measson, Y.; Perrot, Y.; Russotto, F.X. [CEA, LIST, Service de Robotique Interactive, 18 route du Panorama, BP6, F-92265 Fontenay-aux-Roses (France)

    2010-12-15

    A multipurpose carrier prototype called Articulated Inspection Arm (AIA) has been developed and demonstrated by CEA laboratories to operate embedded diagnostics or tools into a tokamak vacuum-vessel. The AIA robot with a vision diagnostic has been deployed inside the vacuum-vessel of Tore Supra tokamak and has realized closed inspections of plasma facing components' under relevant conditions (high vacuum and temperature). CEA is engaged in development of interchangeable diagnostics or tools to be plugged on the front head of the arm. This covers applications such as in-vessel inspections, water leak localization, Plasma Facing Components (PFCs) characterization and treatment. This paper describes R and D activities performed in CEA laboratories to develop diagnostics and tools for in-vessel interventions. The AIA multipurpose carrier to carry such devices is also presented. The first demonstration of a quick intervention for plasma facing components performed in the Tore Supra Facility is described as well.

  1. Thermodynamic evaluation of hydrogen production for fuel cells by using bio-ethanol steam reforming: Effect of carrier gas addition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Liliana; Kafarov, Viatcheslav [Universidad Industrial de Santander, Escuela de Ingenieria Quimica, Bucaramanga 678 (Colombia)

    2009-07-01

    Omitting the influence of the addition of carrier gas to the reaction system for hydrogen production by bio-ethanol steam reforming can lead to wrong conclusions, especially when it is going to be made to scale. The effect of carrier gas addition to produce hydrogen using bio-ethanol steam reforming to feed fuel cells was evaluated. Thermodynamic calculations in equilibrium conditions were made, however the analysis derived from them can also be applied to kinetic conditions. These calculations were made by using the Aspen-HYSYS software at atmospheric pressure and different values of temperature, water/ethanol molar ratios, and inert (argon)/(water/ethanol) molar ratios. The addition of inert carrier gas modifies the concentrations of the reaction products in comparison to those obtained without its presence. This behavior occurs because most of the reactions which take place in bio-ethanol steam reforming have a positive difference of moles. This fact enhances the system sensitivity to inert concentration at low and moderated temperatures (<700 C). At high values of temperature, the inert addition does not influence the composition of the reaction products because of the predominant effect of inverse WGS reaction. (author)

  2. Transient mobility in silicon as seen by a combination of free-carrier absorption and resonance-coupled photoconductive decay

    Science.gov (United States)

    Feldman, Ari; Ahrenkiel, Richard; Lehman, John

    2013-03-01

    The combination of the resonance-coupled photoconductive decay (RCPCD) apparatus and a pump-probe free carrier absorption experiment results in a method of viewing transient mobility. RCPCD uses an Nd:YAG laser operating at 1064 nm to pump the p-type silicon wafer, and a microwave coil antenna detects the transient excess-carrier concentration. The pump-probe experiment uses the same pump laser and a 10.6 μm CO2 laser with HgCdTe photodetector to measure the transient change in absorption. The change in conductivity detected by RCPCD is directly proportional to the excess-carrier concentration (Δn) and mobility (μ), whereas the pump-probe experiment has an inversely proportional relationship. By mathematically combining these signals at equivalent optical fluxes, a quantity proportional to the mobility emerges. The mobility is shown to vary both temporally and with respect to injection, countering the assumption that mobility is constant for photoconductive decay measurements. Theory and results are discussed within.

  3. Low-temperature carrier dynamics in high-mobility organic transistors of alkylated dinaphtho-thienothiophene as investigated by electron spin resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Yutaro; Tanaka, Hisaaki, E-mail: htanaka@nuap.nagoya-u.ac.jp; Kuroda, Shin-ichi [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Shimoi, Yukihiro [Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takimiya, Kazuo [Emergent Molecular Function Research Group, RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198 (Japan)

    2014-07-21

    Charge carriers in high-mobility organic thin-film transistors of alkylated dinaphtho-thienothiophene (C{sub 10}-DNTT) have been directly observed by field-induced electron spin resonance (FI-ESR) down to 4 K. FI-ESR spectra of π-electron hole carriers of C{sub 10}-DNTT exhibited clear anisotropy, indicating a highly organized end-on molecular orientation at the device interface. The intra-grain and inter-grain carrier motion were probed by the motional narrowing effect of the ESR spectra. The intra-grain motion was clearly observed even at 4 K, showing intrinsically high mobility of C{sub 10}-DNTT crystallites. On the other hand, significantly low activation energy of ∼10 meV for inter-grain carrier hopping, compared with pristine DNTT, was observed, which shows that the alkyl substitution drastically enhances the carrier mobility of DNTT system.

  4. Intermittent bursts induced by double tearing mode reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Lai; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    Reversed magnetic shear (RMS) configuration is assumed to be the steady-state operation scenario for the future advanced tokamaks like International Thermonuclear Experimental Reactor. In this work, we numerically discover a phenomenon of violent intermittent bursts induced by self-organized double tearing mode (DTM) reconnection in the RMS configuration during the very long evolution, which may continuously lead to annular sawtooth crashes and thus badly impact the desired steady-state operation of the future advanced RMS tokamaks. The key process of the intermittent bursts in the off-axis region is similar to that of the typical sawtooth relaxation oscillation in the positive magnetic shear configuration. It is interestingly found that in the decay phase of the DTM reconnection, the zonal field significantly counteracts equilibrium field to make the magnetic shear between the two rational surfaces so weak that the residual self-generated vortices of the previous DTM burst are able to trigger a reverse DTM reconnection by curling the field lines.

  5. Low-cost carriers fare competition effect

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2010-01-01

    This paper examines the effects that low-cost carriers (LCC’s) produce when entering new routes operated only by full-service carriers (FSC’s) and routes operated by low-cost carriers in competition with full-service carriers. A mathematical model has been developed to determine what routes should b

  6. Charge-carrier selective electrodes for organic bulk heterojunction solar cell by contact-printed siloxane oligomers

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Hyun-Sik; Khang, Dahl-Young, E-mail: dykhang@yonsei.ac.kr

    2015-08-31

    ‘Smart’ (or selective) electrode for charge carriers, both electrons and holes, in organic bulk-heterojunction (BHJ) solar cells using insertion layers made of hydrophobically-recovered and contact-printed siloxane oligomers between electrodes and active material has been demonstrated. The siloxane oligomer insertion layer has been formed at a given interface simply by conformally-contacting a cured slab of polydimethylsiloxane stamp for less than 100 s. All the devices, either siloxane oligomer printed at one interface only or printed at both interfaces, showed efficiency enhancement when compared to non-printed ones. The possible mechanism that is responsible for the observed efficiency enhancement has been discussed based on the point of optimum symmetry and photocurrent analysis. Besides its simplicity and large-area applicability, the demonstrated contact-printing technique does not involve any vacuum or wet processing steps and thus can be very useful for the roll-based, continuous production scheme for organic BHJ solar cells. - Highlights: • Carrier-selective insertion layer in organic bulk heterojunction solar cells • Simple contact-printing of siloxane oligomers improves cell efficiency. • Printed siloxane layer reduces carrier recombination at electrode surfaces. • Siloxane insertion layer works equally well at both electrode surfaces. • Patterned PDMS stamp shortens the printing time within 100 s.

  7. Reducing the content of carrier polymer in pectin nanofibers by electrospinning at low loading followed with selective washing.

    Science.gov (United States)

    Cui, Sisi; Yao, Bing; Sun, Xue; Hu, Junli; Zhou, Yifa; Liu, Yichun

    2016-02-01

    Nanofibers of natural polymers represent an essential class of materials in biomedicine. Pectin is a plant-sourced anionic polysaccharide widely used in food products and biomedicine owning to its abundance, biocompatibility and inherent bioactivity. However, current electrospun pectin nanofibers are suffered from high content of carrier polymer, which may lead to low integrity and mechanical strength as well as in vivo toxicity. We report here a strategy to reduce the content of carrier polymer, polyethylene oxide (PEO) in our study, in pectin nanofibers, via electrospinning at low loading followed with selective washing. With improved electrospinning condition, we first enabled electrospinning of pectin nanofibers at low PEO loading. Then the PEO was removed by washing with a selective solvent to give pectin nanofibers containing only 1.5% PEO. The strategy was versatile to pectins from various sources and of various degree of esterification. The pectin nanofibers exhibited Young's modulus as high as 358.5MPa. In view of their rich bioactivity, the pectin nanofibers of low content of carrier polymer are promising materials for a wide range of biomedical applications.

  8. Interference of spin-, charge- and orbital degrees of freedom in low-carrier rare earth compounds, investigated by NMR

    Science.gov (United States)

    Wada, S.

    2006-05-01

    In rare earth compounds, the concentration of charge carriers is known to strongly influence the nature, and the charge carriers caused by valence fluctuations result in a complete suppression of the magnetic state, as typically observed for YbInCu4. The notable exception has been reported for the cubic (NaCl structure) TmX and YbX families with low carrier, that exhibits antiferro-magnetic (AFM) order at low temperatures. Among these families, TmTe and YbSb with degenerate low-lying multiplets have an additional transition of antiferro-quadrupolar (AFQ) orderings. To elucidate the interplay between the electronic transport and magnetic and/or orbital phenomena close to a semiconductor-to-metal transition, we have carried NMR measurements of 63Cu in YbInCu4, 125Te in TmTe, and 121Sb in YbSb down to 1.2 K and the implication of NMR findings is discussed in terms of the CEF splitting.

  9. Boundary mode lubrication of articular cartilage by recombinant human lubricin.

    Science.gov (United States)

    Gleghorn, Jason P; Jones, Aled R C; Flannery, Carl R; Bonassar, Lawrence J

    2009-06-01

    Lubrication of cartilage involves a variety of physical and chemical factors, including lubricin, a synovial glycoprotein that has been shown to be a boundary lubricant. It is unclear how lubricin boundary lubricates a wide range of bearings from tissue to artificial surfaces, and if the mechanism is the same for both soluble and bound lubricin. In the current study, experiments were conducted to investigate the hypothesis that recombinant human lubricin (rh-lubricin) lubricates cartilage in a dose-dependent manner and that soluble and bound fractions of rh-lubricin both contribute to the lubrication process. An rh-lubricin dose response was observed with maximal lubrication achieved at concentrations of rh-lubricin greater than 50 microg/mL. A concentration-response variable-slope model was fit to the data, and indicated that rh-lubricin binding to cartilage was not first order. The pattern of decrease in equilibrium friction coefficient indicated that aggregation of rh-lubricin or steric arrangement may regulate boundary lubrication. rh-lubricin localized at the cartilage surface was found to lubricate a cartilage-glass interface in boundary mode, as did soluble rh-lubricin at high concentrations (150 microg/mL); however, the most effective lubrication occurred when both soluble and bound rh-lubricin were present at the interface. These findings point to two distinct mechanisms by which rh-lubricin lubricates, one mechanism involving lubricin bound to the tissue surface and the other involving lubricin in solution.

  10. Bimodal behaviour of charge carriers in graphene induced by electric double layer

    Science.gov (United States)

    Tsai, Sing-Jyun; Yang, Ruey-Jen

    2016-01-01

    A theoretical investigation is performed into the electronic properties of graphene in the presence of liquid as a function of the contact area ratio. It is shown that the electric double layer (EDL) formed at the interface of the graphene and the liquid causes an overlap of the conduction bands and valance bands and increases the density of state (DOS) at the Fermi energy (EF). In other words, a greater number of charge carriers are induced for transport and the graphene changes from a semiconductor to a semimetal. In addition, it is shown that the dependence of the DOS at EF on the contact area ratio has a bimodal distribution which responses to the experimental observation, a pinnacle curve. The maximum number of induced carriers is expected to occur at contact area ratios of 40% and 60%. In general, the present results indicate that modulating the EDL provides an effective means of tuning the electronic properties of graphene in the presence of liquid. PMID:27464986

  11. Detection of wild animals as carriers of Leptospira by PCR in the Pantanal biome, Brazil.

    Science.gov (United States)

    Vieira, Anahi S; Narduche, Lorena; Martins, Gabriel; Schabib Péres, Igor A H F; Zimmermann, Namor P; Juliano, Raquel S; Pellegrin, Aiesca O; Lilenbaum, Walter

    2016-11-01

    Leptospiral infection is widespread in wildlife. In this context, wild ecosystems in tropical countries hold a vast biodiversity, including several species that may act as potential reservoirs of leptospires. The Pantanal biome presents highly favorable environmental conditions for the occurrence of leptospirosis, such as high temperatures, constant flooding, and high biodiversity. The purpose of this study was to detect wild animals as carriers of Leptospira sp. using direct methods (PCR and culture) in the Pantanal biome, Brazil. A total of 35 animals were studied, namely Cerdocyon thous, Nasua nasua, Ozotoceros bezoarticus, and Sus scrofa species. Blood for serology (MAT) and urine for bacteriological culturing and PCR was sampled. The most prevalent serogroups were Javanica and Djasiman. Additionally, 40.6% of these animals presented PCR positive reactions. Seroreactivity associated with the high frequency of leptospiral carriers among the different studied species suggests a high level of exposure of the studied animals to pathogenic Leptospira strains. Our results are still limited and the actual role of the studied animals in the epidemiology of leptospirosis in the Pantanal region remains to be elucidated.

  12. On the generation of internal wave modes by surface waves

    Science.gov (United States)

    Harlander, Uwe; Kirschner, Ian; Maas, Christian; Zaussinger, Florian

    2016-04-01

    Internal gravity waves play an important role in the ocean since they transport energy and momentum and the can lead to mixing when they break. Surface waves and internal gravity waves can interact. On the one hand, long internal waves imply a slow varying shear current that modifies the propagation of surface waves. Surface waves generated by the atmosphere can, on the other hand, excite internal waves by nonlinear interaction. Thereby a surface wave packet consisting of two close frequencies can resonate with a low frequency internal wave (Phillips, 1966). From a theoretical point of view, the latter has been studied intensively by using a 2-layer model, i.e. a surface layer with a strong density contrast and an internal layer with a comparable weak density contrast (Ball, 1964; Craig et al., 2010). In the present work we analyse the wave coupling for a continuously stratified fluid using a fully non-linear 2D numerical model (OpenFoam) and compare this with laboratory experiments (see Lewis et al. 1974). Surface wave modes are used as initial condition and the time development of the dominant surface and internal waves are studied by spectral and harmonic analysis. For the simple geometry of a box, the results are compared with analytical spectra of surface and gravity waves. Ball, F.K. 1964: Energy transfer between external and internal gravity waves. J. Fluid Mech. 19, 465. Craig, W., Guyenne, P., Sulem, C. 2010: Coupling between internal and surface waves. Natural Hazards 57, 617-642. Lewis, J.E., Lake, B.M., Ko, D.R.S 1974: On the interaction of internal waves and surfacr gravity waves, J. Fluid Mech. 63, 773-800. Phillips, O.M. 1966: The dynamics of the upper ocean, Cambridge University Press, 336pp.

  13. Oscillation mode frequencies of 61 main-sequence and subgiant stars observed by Kepler

    DEFF Research Database (Denmark)

    Appourchaux, T.; Chaplin, W. J.; García, R. A.

    2012-01-01

    estimators and Bayesian estimators, providing individual mode characteristics such as frequencies, linewidths, and mode heights. We developed and describe a methodology for extracting a single set of mode frequencies from multiple sets derived by different methods and individual scientists. We report on how...

  14. Zonal Flows Driven by Small-Scale Drift-Alfven Modes

    Institute of Scientific and Technical Information of China (English)

    李德徽; 周登

    2011-01-01

    Generation of zonal flows by small-scale drift-Alfven modes is investigated by adopting the approach of parametric instability with the electron polarization drift included. The zonal mode can be excited by primary modes propagating at both electron and ion diamagnetic drift directions in contrast to the assertion in previous studies that only primary modes propagating in the ion diamagnetic drift directions can drive zonal instabilities. Generally, the growth rate of the driven zonal mode is in the same order as that in previous study. However, different from the previous work, the growth rate is no longer proportional to the difference between the diamagnetic drift frequencies of electrons and ions.

  15. Rate-equation model for multi-mode semiconductor lasers with spatial hole burning.

    Science.gov (United States)

    Lenstra, Daan; Yousefi, Mirvais

    2014-04-07

    We present a set of rate equations for the modal amplitudes and carrier-inversion moments that describe the deterministic multi-mode dynamics of a semiconductor laser due to spatial hole burning. Mutual interactions among the lasing modes, induced by high- frequency modulations of the carrier distribution, are included by carrier-inversion moments for which rate equations are given as well. We derive the Bogatov effect of asymmetric gain suppression in semiconductor lasers and illustrate the potential of the model for a two and three-mode laser by numerical and analytical methods.

  16. Acoustic one-way mode conversion and transmission by sonic crystal waveguides

    CERN Document Server

    Ouyang, Shiliang; He, Zhaojian; Deng, Ke; Zhao, Heping

    2016-01-01

    We proposed a scheme to achieve one-way acoustic propagation and even odd mode switching in two mutually perpendicular sonic crystal waveguides connected by a resonant cavity. The even mode in the entrance waveguide is able to switch to odd mode in the exit waveguide through a symmetry match between the cavity resonant modes and the waveguide modes. Conversely, the odd mode in the exit waveguide is unable to be converted into the even mode in the entrance waveguide as incident waves and eigenmodes are mismatched in their symmetries at the waveguide exit. This one way mechanism can be applied to design an acoustic diode for acoustic integration devices and can be used as a convertor of the acoustic waveguide modes.

  17. Inappropriate mode switching clarified by using a chest radiograph.

    Science.gov (United States)

    Marino, Brian; Jaiswal, Abhishek; Goldbarg, Seth

    2015-08-01

    An 80-year-old woman with a history of paroxysmal atrial fibrillation and atrioventricular node disease status post-dual chamber pacemaker placement was noted to have abnormal pacing episodes during a percutaneous coronary intervention. Pacemaker interrogation revealed a high number of short duration mode switching episodes. Representative electrograms demonstrated high frequency nonphysiologic recordings predominantly in the atrial lead. Intrinsic pacemaker malfunction was excluded. A chest radiograph showed excess atrial and ventricular lead slack in the right ventricular inflow. It was suspected that lead-lead interaction resulted in artifacts and oversensing, causing frequent short episodes of inappropriate mode switching.

  18. Observation of trapping and release of carriers in InGaAs/GaAs quantum dots by ultrafast THz spectroscopy

    DEFF Research Database (Denmark)

    Porte, Henrik; Jepsen, Peter Uhd; Daghestani, Nart;

    2009-01-01

    Depending on the photoexcitation wavelength, we either observe the trapping of the free carriers into quantum dots, or release of carriers from quantum dot ground state into conducting states of the quantum dot sample.......Depending on the photoexcitation wavelength, we either observe the trapping of the free carriers into quantum dots, or release of carriers from quantum dot ground state into conducting states of the quantum dot sample....

  19. Improvement of minority carrier life time in N-type monocrystalline Si by the Czochralski method

    Science.gov (United States)

    Baik, Sungsun; Pang, Ilsun; Kim, Jaemin; Kim, Kwanghun

    2016-07-01

    The installation amount of solar power plants increases every year. Multi-crystalline Si solar cells comprise a large share of the market of solar power plants. Multi-crystalline and single-crystalline Si solar cells are competing against one another in the market. Many single-crystalline companies are trying to develop and produce n-type solar cells with higher cell efficiency than that of p-type. In n-type wafers with high cell efficiency, wafer quality has become increasingly important. In order to make ingots with higher MCLT, the effects of both poly types related to metal impurities and pull speeds related to vacancy concentration on minority carrier life time were studied. In the final part of ingots, poly types related to the metal impurities are a dominant factor on MCLT. In the initial part of ingots, pull speeds related to vacancy concentration are a dominant factor on MCLT. [Figure not available: see fulltext.

  20. Hydrogen carriers

    Science.gov (United States)

    He, Teng; Pachfule, Pradip; Wu, Hui; Xu, Qiang; Chen, Ping

    2016-12-01

    Hydrogen has the potential to be a major energy vector in a renewable and sustainable future energy mix. The efficient production, storage and delivery of hydrogen are key technical issues that require improvement before its potential can be realized. In this Review, we focus on recent advances in materials development for on-board hydrogen storage. We highlight the strategic design and optimization of hydrides of light-weight elements (for example, boron, nitrogen and carbon) and physisorbents (for example, metal-organic and covalent organic frameworks). Furthermore, hydrogen carriers (for example, NH3, CH3OH-H2O and cycloalkanes) for large-scale distribution and for on-site hydrogen generation are discussed with an emphasis on dehydrogenation catalysts.

  1. Biotin uptake by mouse and human pancreatic beta cells/islets: a regulated, lipopolysaccharide-sensitive carrier-mediated process.

    Science.gov (United States)

    Ghosal, Abhisek; Sekar, Thillai V; Said, Hamid M

    2014-08-01

    Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors. We addressed these issues using the mouse-derived pancreatic beta-TC-6 cells and freshly isolated mouse and human primary pancreatic beta cells as models. The results showed biotin uptake by pancreatic beta-TC-6 cells occurs via a Na(+)-dependent, carrier-mediated process, that is sensitive to desthiobiotin, as well as to pantothenic acid and lipoate; the process is also saturable as a function of concentration (apparent Km = 22.24 ± 5.5 μM). These cells express the sodium-dependent multivitamin transporter (SMVT), whose knockdown (with doxycycline-inducible shRNA) led to a sever inhibition in biotin uptake. Similarly, uptake of biotin by mouse and human primary pancreatic islets is Na(+)-dependent and carrier-mediated, and both cell types express SMVT. Biotin uptake by pancreatic beta-TC-6 cells is also adaptively regulated (via transcriptional mechanism) by extracellular substrate level. Chronic treatment of pancreatic beta-TC-6 cells with bacterial lipopolysaccharides (LPS) leads to inhibition in biotin uptake. This inhibition is mediated via a Toll-Like receptor 4-mediated process and involves a decrease in membrane expression of SMVT. These findings show, for the first time, that pancreatic beta cells/islets take up biotin via a specific and regulated carrier-mediated process, and that the process is sensitive to the effect of LPS.

  2. Bases for time-resolved probing of transient carrier dynamics by optical pump-probe scanning tunneling microscopy.

    Science.gov (United States)

    Yokota, Munenori; Yoshida, Shoji; Mera, Yutaka; Takeuchi, Osamu; Oigawa, Haruhiro; Shigekawa, Hidemi

    2013-10-07

    The tangled mechanism that produces optical pump-probe scanning tunneling microscopy spectra from semiconductors was analyzed by comparing model simulation data with experimental data. The nonlinearities reflected in the spectra, namely, the excitations generated by paired laser pulses with a delay time, the logarithmic relationship between carrier density and surface photovoltage (SPV), and the effect of the change in tunneling barrier height depending on SPV, were examined along with the delay-time-dependent integration process used in measurement. The optimum conditions required to realize reliable measurement, as well as the validity of the microscopy technique, were demonstrated for the first time.

  3. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    Energy Technology Data Exchange (ETDEWEB)

    Hebishima, Takehisa [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tada, Seiichi [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Takeshima, Shin-nosuke [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501 (Japan); Ito, Yoshihiro [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aida, Yoko, E-mail: aida@riken.jp [Viral Infectious Diseases Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer To develop effective vaccine, we examined the effects of CO{sub 3}Ap as an antigen carrier. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap was taken up by BMDCs more effectively than free OVA. Black-Right-Pointing-Pointer OVA-immunized splenocytes was activated by OVA contained in CO{sub 3}Ap effectively. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap induced strong OVA-specific immune responses to C57BL/6 mice. Black-Right-Pointing-Pointer CO{sub 3}Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO{sub 3}Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO{sub 3}Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO{sub 3}Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO{sub 3}Ap induced the proliferation and antigen-specific production of IFN-{gamma} by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO{sub 3}Ap and OVA-containing alumina salt (Alum), suggesting that CO{sub 3}Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO{sub 3}Ap.

  4. Kinetic freeze-out, particle spectra, and harmonic-flow coefficients from mode-by-mode hydrodynamics

    Science.gov (United States)

    Floerchinger, Stefan; Wiedemann, Urs Achim

    2014-03-01

    The kinetic freeze-out for the hydrodynamical description of relativistic heavy-ion collisions is discussed using a background-fluctuation splitting of the hydrodynamical fields. For a single event, the particle spectrum, or its logarithm, can be written as the sum of the background part that is symmetric with respect to azimuthal rotations and longitudinal boosts and a part containing the contribution of fluctuations or deviations from the background. Using a complete orthonormal basis to characterize the initial state allows one to write the double differential harmonic-flow coefficients determined by the two-particle correlation method as matrix expressions involving the initial fluid correlations. We discuss the use of these expressions for a mode-by-mode analysis of fluctuating initial conditions in heavy-ion collisions.

  5. Molluscan mega-hemocyanin: an ancient oxygen carrier tuned by a ~550 kDa polypeptide

    Directory of Open Access Journals (Sweden)

    Harasewych Myroslaw G

    2010-05-01

    Full Text Available Abstract Background The allosteric respiratory protein hemocyanin occurs in gastropods as tubular di-, tri- and multimers of a 35 × 18 nm, ring-like decamer with a collar complex at one opening. The decamer comprises five subunit dimers. The subunit, a 400 kDa polypeptide, is a concatenation of eight paralogous functional units. Their exact topology within the quaternary structure has recently been solved by 3D electron microscopy, providing a molecular model of an entire didecamer (two conjoined decamers. Here we study keyhole limpet hemocyanin (KLH2 tridecamers to unravel the exact association mode of the third decamer. Moreover, we introduce and describe a more complex type of hemocyanin tridecamer discovered in fresh/brackish-water cerithioid snails (Leptoxis, Melanoides, Terebralia. Results The "typical" KLH2 tridecamer is partially hollow, whereas the cerithioid tridecamer is almost completely filled with material; it was therefore termed "mega-hemocyanin". In both types, the staggering angle between adjoining decamers is 36°. The cerithioid tridecamer comprises two typical decamers based on the canonical 400 kDa subunit, flanking a central "mega-decamer" composed of ten unique ~550 kDa subunits. The additional ~150 kDa per subunit substantially enlarge the internal collar complex. Preliminary oxygen binding measurements indicate a moderate hemocyanin oxygen affinity in Leptoxis (p50 ~9 mmHg, and a very high affinity in Melanoides (~3 mmHg and Terebralia (~2 mmHg. Species-specific and individual variation in the proportions of the two subunit types was also observed, leading to differences in the oligomeric states found in the hemolymph. Conclusions In cerithioid hemocyanin tridecamers ("mega-hemocyanin" the collar complex of the central decamer is substantially enlarged and modified. The preliminary O2 binding curves indicate that there are species-specific functional differences in the cerithioid mega-hemocyanins which might reflect

  6. Effect of Variation in the Burst Mode and Carrier Frequency of High Intensity Electrical Stimulation on Muscle Fatigue and Pain Perception of Healthy Subjects

    Science.gov (United States)

    1988-10-22

    work supports the "size principle’ espoused by Henneman (1965) and confirmed by electromyographic studies using fine wire electrodes (Hannez, 1974...q1adricepS 5:c~ ?s-c~e.azle e i-rmoilization. kmearican 3oarna of S or-s Mec.:lne, 13, 4D-45. Mosso, A. JI!15). Faigue (3rd ed.). Translated by Drnond

  7. Study on vibrational modes by group theory and infrared spectra by D FT for calcite crystal

    Institute of Scientific and Technical Information of China (English)

    Danhua Lou; Fengjiu Sun; Lijuan Li

    2007-01-01

    The factor group symmetry analysis (FSA) method and position symmetry analysis (PSA) method are used to analyze the vibrational modes of calcite (CaCO3) crystal, respectively. With the activated results of infrared and Raman spectra presented, strong points of each method are concluded. The infrared spectra are studied by using dynamics calculations based on density-functional theory (DFT) with the supercell model of calcite crystal. The frequencies of 27 normal modes are achieved, which are consistent with that by the group symmetry analysis very well, and fit with the experimental results better than the lattice dynamical methods.

  8. Dynamical instability induced by the zero mode under symmetry breaking external perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, J., E-mail: phyco-sevenface@asagi.waseda.jp; Nakamura, Y., E-mail: nakamura@aoni.waseda.jp; Yamanaka, Y., E-mail: yamanaka@waseda.jp

    2014-08-15

    A complex eigenvalue in the Bogoliubov–de Gennes equations for a stationary Bose-Einstein condensate in the ultracold atomic system indicates the dynamical instability of the system. We also have the modes with zero eigenvalues for the condensate, called the zero modes, which originate from the spontaneous breakdown of symmetries. Although the zero modes are suppressed in many theoretical analyses, we take account of them in this paper and argue that a zero mode can change into one with a pure imaginary eigenvalue by applying a symmetry breaking external perturbation potential. This emergence of a pure imaginary mode adds a new type of scenario of dynamical instability to that characterized by the complex eigenvalue of the usual excitation modes. For illustration, we deal with two one-dimensional homogeneous Bose–Einstein condensate systems with a single dark soliton under a respective perturbation potential, breaking the invariance under translation, to derive pure imaginary modes. - Highlights: • Zero modes are important but ignored in many theories for the cold atomic system. • We discuss the zero mode under symmetry breaking potential in this system. • We consider the zero mode of translational invariance for a single dark soliton. • We show that it turns into an anomalous or pure imaginary mode.

  9. Immunization of mice by Hollow Mesoporous Silica Nanoparticles as carriers of Porcine Circovirus Type 2 ORF2 Protein

    Directory of Open Access Journals (Sweden)

    Guo Hui-Chen

    2012-06-01

    Full Text Available Abstract Backgroud Porcine circovirus type 2 (PCV2 is a primary etiological agent of post-weaning multi-systemic wasting syndrome (PMWS, which is a disease of increasing importance to the pig industry worldwide. Hollow mesoporous silica nanoparticles (HMSNs have gained increasing interest for use in vaccines. Methods To study the potential of HMSNs for use as a protein delivery system or vaccine carriers. HMSNs were synthesized by a sol–gel/emulsion(oil-in-water/ethanol method, purified PCV2 GST-ORF2-E protein was loaded into HMSNs, and the resulting HMSN/protein mixture was injected into mice. The uptake and release profiles of protein by HMSNs in vitro were investigated. PCV2 GST-ORF2-E specific antibodies and secretion of IFN-γ were detected by enzyme-linked immunosorbent assays, spleen lymphocyte proliferation was measured by the MTS method, and the percentage of CD4+ and CD8+ were determined by flow cytometry. Results HMSNs were found to yield better binding capacities and delivery profiles of proteins; the specific immune response induced by PCV2 GST-ORF2-E was maintained for a relatively long period of time after immunization with the HMSN/protein complex. Conclusion The findings suggest that HMSNs are good protein carriers and have high potential for use in future applications in therapeutic drug delivery.

  10. Absorption of Light by Free Charge Carriers in the Crystalline CdS Under Intense Electron Irradiation

    Science.gov (United States)

    Kulikov, V. D.; Yakovlev, V. Yu.

    2016-09-01

    The process of light absorption by free electrons in the crystalline cadmium sulfide under irradiation by a nanosecond electron beam with the current density of 8-100 A/cm2 is studied. A superlinear increase in optical absorption is observed if the beam current density is increased from ~8 to 12 A/cm2. The nature of light absorption by thermalized electrons corresponds to the scattering on lattice defects. An increase in the exponent of the power dependence of light absorption on the wavelength with increasing beam current density is associated with the single and double ionization of donors and acceptors. It is concluded that accumulation of charge carriers occurs without capture by traps due to their impact ionization by secondary electrons, whose energy in the thermalization stage is comparable with the band gap of the crystal. According to the results of calculations, the capture cross section of electrons by holes at quadratic recombination is ~10-20 cm2, the Auger recombination coefficient is ~10-31 cm6•s-1, and the charge carrier concentration is ~1.3•1018-1.5•1019 cm-3.

  11. Characteristics of THz carrier dynamics in GaN thin film and ZnO nanowires by temperature dependent terahertz time domain spectroscopy measurement

    Science.gov (United States)

    Balci, Soner; Baughman, William; Wilbert, David S.; Shen, Gang; Kung, Patrick; Kim, Seongsin Margaret

    2012-12-01

    We present a comprehensive study of the characteristics of carrier dynamics using temperature dependent terahertz time domain spectroscopy. By utilizing this technique in combination with numerical calculations, the complex refractive index, dielectric function, and conductivity of n-GaN, undoped ZnO NWs, and Al-doped ZnO NWs were obtained. The unique temperature dependent behaviors of major material parameters were studied at THz frequencies, including plasma frequency, relaxation time, carrier concentration and mobility. Frequency and temperature dependent carrier dynamics were subsequently analyzed in these materials through the use of the Drude and the Drude-Smith models.

  12. Atomic nuclei decay modes by spontaneous emission of heavy ions

    OpenAIRE

    Poenaru, Dorin N.; Ivaşcu, Marin; Săndulescu, Aurel; Greiner, Walter

    2006-01-01

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead n...

  13. Protection and viability of fruit seeds oils by nanostructured lipid carrier (NLC) nanosuspensions.

    Science.gov (United States)

    Krasodomska, Olga; Paolicelli, Patrizia; Cesa, Stefania; Casadei, Maria Antonietta; Jungnickel, Christian

    2016-10-01

    In this paper, we focused on the development of nanostructured lipid carriers (NLCs) for dermal application. The NLC matrix was designed as a protective reservoir of biological active compounds that naturally occur in domestic fruit seed oils. Over the years, emulsions, as a popular physicochemical form of personal care products, were refined in order to obtain the best possible penetration into the skin of any bioactive compound introduced in the formulation, such as polyunsaturated fatty acids (PUFAs). In fact, the bioactive components are useful only if they are able to penetrate the skin unchanged. Therefore, an alternate way to deliver naturally occurring PUFAs is needed. NLCs present a novel delivery and protection system for the PUFAs. The cold pressed fruit seed oils obtained from waste material were used in this paper: blackcurrant, blackberry, raspberry, strawberry and plum. Thermodynamic (DSC) and structural techniques ((1)H NMR) were applied in order to characterize the obtained systems in terms of seed oil incorporation into the NLC, and oxidative stability tests were used to confirm the protective quality of the systems. During the formulation optimization process the most stable nanosuspension with the best seed oil incorporation was a mixture of 4% nonionic emulsifiers, 88% water and 6% lipids with a ratio of 6:2, wax:oil. The oxidative stability tests showed that the NLC was an effective method of protection of the PUFAs.

  14. Carrier Screening and Prenatal Gene Diagnosis of β-thalassemia by PCR-RDB Technique

    Institute of Scientific and Technical Information of China (English)

    张宏秀; 单可人; 惠春林; 何燕; 袁筑华; 窦友莲; 曾金琳; 谢渊; 修瑾

    2003-01-01

    In order to identify the distribution of gene types of β-thalassemia and reduce the birthrates of β-thalassemia major in Guiyang area, 1054 pregnant women and their spouses from Affiliated Hospital, Guiyang Medical College were screened. The positive samples were analyzed with polymerase chain reaction and reverse dot blot method (PCR-RDB). When both partners were heterozygous identified as carriers for β- thalassemia, the risk of having a fetus who was homozygous or compound heterozygous was 2.66 %; the ratio of male to female was 1/1.15. Seven types of mutation were identified. CD17 and CD41-42 were dominant among them. Among the 4 cases subject to prenatal gene diagnosis, one fetus was completely normal and 3 fetuses were diagnosed as having β-thalassemia major (1 homozygous and 2 compound heterozygous). The fetuses diagnosed as β-thalassemia major were selectively terminated within two weeks. It was concluded that the birthrate of β-thalassemia major in Guiyang area was reduced and the target of improving birth outcome and child development has been achieved.

  15. Carrier detection and early diagnosis of Wilson's disease by restriction fragment length polymorphism analysis.

    Science.gov (United States)

    Figus, A; Lampis, R; Devoto, M; Ristaldi, M S; Ideo, A; de Virgilis, S; Nurchi, A M; Corrias, A; Corda, R; Lai, M E

    1989-01-01

    Wilson's disease, a rare autosomal recessive disorder, has been recently mapped to the long arm of chromosome 13 (q14.1). In this study, we carried out linkage analysis between three chromosome 13 DNA markers, D13S1, D13S10, D13S2, the locus for the red cell enzyme esterase D (ESD), and the Wilson's disease locus (WND) in 17 Wilson's disease families of Italian descent, mostly from Sardinia. We confirmed a tight linkage [theta = 0.00, Z (theta) = 4.07] between the WND and ESD loci, and provided suggestive evidence for linkage [theta = 0.00, Z(theta) = 1.85] of the WND locus with D13S10. Multipoint linkage analysis indicated the following order: centromere-D13S1-D13S10-WND-ESD-D13S2. RFLP analysis at these two loci in our families allowed us either to define the carrier status (50%) or to exclude the homozygous state (25%) in the great majority of unaffected sibs. PMID:2563776

  16. Investigation of carriers of lustrous carbon at high temperatures by infrared spectroscopy (FTIR

    Directory of Open Access Journals (Sweden)

    S. Eichholz

    2010-10-01

    Full Text Available Lustrous carbon is very important in processes of iron casting in green sand. Lustrous carbon (pirografit is a microcrystalline carbon form, which evolves from a gaseous phase. In the case of applying additions, generating lustrous carbon, for sands with bentonite, there is always a danger of emitting – due to a high temperature of liquid cast iron and a humidity - compounds hazardous for a human health. There can be: CO, SO2, benzene, toluene, ethylbenzene, xylene (the so-called: BTEX as well as polycyclic aromatic hydrocarbons(PAHs. In order to asses the selected mixtures: bentonite – carrier of lustrous carbon, in which a coal dust fraction was limited, thethermogravimetric analysis and the analysis of evolving gases were performed. Examinations were carried out in the ApplictaionsLaboratory NITZSCH-Gerätebau GmbH ,Selb/Bavaria, Germany. The NETZSCH TG 209 F1 Iris® thermal analyzer coupled to the BRUKER Optics FTIR TENSOR(TM was used to measure.

  17. Enhanced discrimination of malignant from benign pancreatic disease by measuring the CA 19-9 antigen on specific protein carriers.

    Directory of Open Access Journals (Sweden)

    Tingting Yue

    Full Text Available The CA 19-9 assay detects a carbohydrate antigen on multiple protein carriers, some of which may be preferential carriers of the antigen in cancer. We tested the hypothesis that the measurement of the CA 19-9 antigen on individual proteins could improve performance over the standard CA 19-9 assay. We used antibody arrays to measure the levels of the CA 19-9 antigen on multiple proteins in serum or plasma samples from patients with pancreatic adenocarcinoma or pancreatitis. Sample sets from three different institutions were examined, comprising 531 individual samples. The measurement of the CA 19-9 antigen on any individual protein did not improve upon the performance of the standard CA 19-9 assay (82% sensitivity at 75% specificity for early-stage cancer, owing to diversity among patients in their CA 19-9 protein carriers. However, a subset of cancer patients with no elevation in the standard CA 19-9 assay showed elevations of the CA 19-9 antigen specifically on the proteins MUC5AC or MUC16 in all sample sets. By combining measurements of the standard CA 19-9 assay with detection of CA 19-9 on MUC5AC and MUC16, the sensitivity of cancer detection was improved relative to CA 19-9 alone in each sample set, achieving 67-80% sensitivity at 98% specificity. This finding demonstrates the value of measuring glycans on specific proteins for improving biomarker performance. Diagnostic tests with improved sensitivity for detecting pancreatic cancer could have important applications for improving the treatment and management of patients suffering from this disease.

  18. High-resolution wind and temperature observations from aircraft tracked by Mode-S air traffic control radar

    Science.gov (United States)

    de Haan, S.

    2011-05-01

    Wind, temperature, and humidity observations from radiosonde and aircraft are the main sources of upper air information for meteorology. For mesoscale meteorology, the horizontal coverage of radiosondes is too sparse. Aircraft observations through Aircraft Meteorological Data Relay (AMDAR) sample an atmospheric profile in the vicinity of airports. However, not all aircraft are equipped with AMDAR or have the system activated. Observations inferred from an enhanced tracking and ranging (TAR) air traffic control radar can fill this gap. These radars follows all aircraft in the airspace visible to the radar for air traffic management. The TAR radar at Schiphol airport in Netherlands has a range of 270 km. This Mode-S radar contacts each aircraft every 4 s on which the transponder in the aircraft responds with a message that contains information on flight level, direction, and speed. Combined with the ground track of an aircraft, meteorological information on temperature and wind can be inferred from this information. Because all aircraft are required to respond to the TAR radar, the data volume is extremely large, being around 1.5 million observations per day. Note that there are no extra costs for this data link. The quality of these observations is assessed by comparison to numerical weather prediction (NWP) model information, AMDAR observations, and radiosonde observations. A preprocessing step is applied to enhance the quality of wind and temperature observations, albeit with a reduced time frequency of one observation of horizontal wind vector and temperature per aircraft per minute. Nevertheless, the number of observations per day is still very large. In this paper it is shown that temperature observations from Mode-S, even after corrections, are not very good; an RMS which is twice as large as AMDAR is observed when compared to NWP. In contrast to the temperature observations, the quality found for wind after correction and calibration is good; it is comparable

  19. Determination of the carrier concentration in CdSe crystals from the effective infrared absorption coefficient measured by means of the photothermal infrared radiometry

    Energy Technology Data Exchange (ETDEWEB)

    Pawlak, M. [Nicolaus Copernicus University, Faculty of Physics, Astronomy and Informatics, Institute of Physics, Torun (Poland)

    2014-11-11

    In this paper, a non-contact method that allows to determine the carrier concentration in CdSe crystals is presented. The method relies on the measurement of the effective infrared absorption coefficient by means of the photothermal infrared radiometry (PTR). In order to obtain the effective infrared absorption coefficient and thermal diffusivity, the frequency characteristics of the PTR signal were analyzed in the frame of a one-dimensional heat transport model for infrared semitransparent crystals. The carrier concentrations were estimated using a theory introduced by Ruda and a recently proposed normalization procedure for the PTR signal. The deduced carrier concentrations of the investigated CdSe crystals are in reasonable agreement with those obtained using Hall measurements and infrared spectroscopy. The method presented in this paper can also be applied to other semiconductors with the carrier concentration in the range of 10{sup 14}-10{sup 17} cm{sup -3}. (orig.)

  20. Dual-mode operation of a twisted nematic liquid crystal cell by switching between dynamic and memory modes.

    Science.gov (United States)

    Song, Dong Han; Kim, Ki-Han; Kim, Jung-Wook; Kim, Jae Chang; Yoon, Tae-Hoon

    2011-06-01

    We propose a twisted nematic liquid crystal device that can be operated in dynamic or memory mode, based on the information content to be displayed at that time. +90°-twisted and -90°-twisted states are used as two stable states for operation in the memory mode. A vertical electric field is applied to realize gray levels for operation in the dynamic mode. The proposed device has a memory retention time of over a month for the memory mode and a response time of 12 ms for the dynamic mode. Contrast ratios of over 500∶1 can be obtained in both the dynamic and memory modes.

  1. Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod; Andersen, Michael A. E.

    2009-01-01

    and output is required, such as in audio power amplifiers or xDSL drivers. From an average-mode point of view, carrier distortion is shown to be caused by nonlinear variation of the hysteretic comparator input average voltage with the output average voltage. This easily causes total harmonic distortion.......03% THD from 100 Hz to 6.7 kHz. Carrier distortion is shown to account for this limitation in THD performance....

  2. Carrier recombination spatial transfer by reduced potential barrier causes blue/red switchable luminescence in C8 carbon quantum dots/organic hybrid light-emitting devices

    Directory of Open Access Journals (Sweden)

    Xifang Chen

    2016-04-01

    Full Text Available The underlying mechanism behind the blue/red color-switchable luminescence in the C8 carbon quantum dots (CQDs/organic hybrid light-emitting devices (LEDs is investigated. The study shows that the increasing bias alters the energy-level spatial distribution and reduces the carrier potential barrier at the CQDs/organic layer interface, resulting in transition of the carrier transport mechanism from quantum tunneling to direct injection. This causes spatial shift of carrier recombination from the organic layer to the CQDs layer with resultant transition of electroluminescence from blue to red. By contrast, the pure CQDs-based LED exhibits green–red electroluminescence stemming from recombination of injected carriers in the CQDs.

  3. Screening for JH1 genetic defect carriers in Jersey cattle by a polymerase chain reaction and restriction fragment length polymorphism assay.

    Science.gov (United States)

    Zhang, Yi; Guo, Gang; Huang, Hetian; Lu, Lu; Wang, Lijie; Fang, Lingzhao; Liu, Lin; Wang, Yachun; Zhang, Shengli

    2015-09-01

    An autosomal recessive genetic defect termed JH1 has been associated with early embryonic loss in the Jersey cattle breed. The genetic basis has been identified as a cytosine to thymine mutation in the CWC15 gene that changes an amino acid from arginine to a stop code. To screen for JH1 carriers in an imported Jersey population in China, a method based on a polymerase chain reaction amplification followed by a restriction fragment length polymorphism assay (PCR-RFLP) was developed for the accurate diagnosis of the JH1 allele. A total of 449 randomly chosen cows were examined with the PCR-RFLP assay, and 31 were identified as JH1 carriers, corresponding to a carrier frequency of 6.9%. The PCR-RFLP method was validated by DNA sequencing of 8 positive and 13 negative samples, with all 21 samples giving the expected DNA sequence. In addition, 3 negative and 3 positive samples were confirmed by a commercial microarray-based single nucleotide polymorphism assay. Finally, samples from 9 bulls in the United States of known status were correctly identified as carriers (5 bulls) or noncarriers (4 bulls). As the JH1 defect has most likely spread worldwide, implementing routine screening is necessary to avoid the risk of carrier-to-carrier matings and to gradually eradicate the deleterious gene.

  4. MS2 virus inactivation by atmospheric-pressure cold plasma using different gas carriers and power levels.

    Science.gov (United States)

    Wu, Yan; Liang, Yongdong; Wei, Kai; Li, Wei; Yao, Maosheng; Zhang, Jue; Grinshpun, Sergey A

    2015-02-01

    In this study, airborne MS2 bacteriophages were exposed for subsecond time intervals to atmospheric-pressure cold plasma (APCP) produced using different power levels (20, 24, and 28 W) and gas carriers (ambient air, Ar-O2 [2%, vol/vol], and He-O2 [2%, vol/vol]). In addition, waterborne MS2 viruses were directly subjected to the APCP treatment for up to 3 min. MS2 viruses with and without the APCP exposure were examined by scanning electron microscopy (SEM), reverse transcription-PCR (RT-PCR), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Viral inactivation was shown to exhibit linear relationships with the APCP generation power and exposure time (R(2) > 0.95 for all energy levels tested) up to 95% inactivation (1.3-log reduction) after a subsecond airborne exposure at 28 W; about the same inactivation level was achieved for waterborne viruses with an exposure time of less than 1 min. A larger amount of reactive oxygen species (ROS), such as atomic oxygen, in APCP was detected for a higher generation power with Ar-O2 and He-O2 gas carriers. SEM images, SDS-PAGE, and agarose gel analysis of exposed waterborne viruses showed various levels of damage to both surface proteins and their related RNA genes after the APCP exposure, thus leading to the loss of their viability and infectivity.

  5. Carrier separation and transport in perovskite solar cells studied by nanometre-scale profiling of electrical potential

    Science.gov (United States)

    Jiang, Chun-Sheng; Yang, Mengjin; Zhou, Yuanyuan; To, Bobby; Nanayakkara, Sanjini U.; Luther, Joseph M.; Zhou, Weilie; Berry, Joseph J.; van de Lagemaat, Jao; Padture, Nitin P.; Zhu, Kai; Al-Jassim, Mowafak M.

    2015-09-01

    Organometal-halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells--which are the fundamental mechanisms of device operation and critical factors for power output--by determining the junction structure across the device using the nanoelectrical characterization technique of Kelvin probe force microscopy. The distribution of electrical potential across both planar and porous devices demonstrates p-n junction structure at the TiO2/perovskite interfaces and minority-carrier diffusion/drift operation of the devices, rather than the operation mechanism of either an excitonic cell or a p-i-n structure. Combining the potential profiling results with solar cell performance parameters measured on optimized and thickened devices, we find that carrier mobility is a main factor that needs to be improved for further gains in efficiency of the perovskite solar cells.

  6. Characterization of naproxen-loaded solid SMEDDSs prepared by spray drying: the effect of the polysaccharide carrier and naproxen concentration.

    Science.gov (United States)

    Čerpnjak, Katja; Zvonar, Alenka; Vrečer, Franc; Gašperlin, Mirjana

    2015-05-15

    The purpose of this study was to prepare solid SMEDDS (sSMEDDS) particles produced by spray-drying using maltodextrin (MD), hypromellose (HPMC), and a combination of the two as a solid carrier. Naproxen (NPX) as the model drug was dissolved (at 6% concentration) or partially suspended (at 18% concentration) in a liquid SMEDDS composed of Miglyol(®) 812, Peceol™, Gelucire(®) 44/14, and Solutol(®) HS 15. Among the sSMEDDSs tested, the MD-based sSMEDDSs (with a granular, smooth-surfaced, microspherical appearance) preserved the self-microemulsifying properties of liquid SMEDDSs and exhibited dissolution profiles similar to those of liquid SMEDDSs, irrespective of the concentration of NPX. In contrast, HPMC-based sSMEDDSs (irregular-shaped microparticles) exhibited slightly prolonged release times due to the polymeric nature of the carrier. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), and Raman mapping analysis confirmed molecularly dissolved NPX (at 6% of drug loading), whereas at 18% NPX loading drug is partially molecularly dissolved and partially in the crystalline state.

  7. Carrier separation and transport in perovskite solar cells studied by nanometre-scale profiling of electrical potential.

    Science.gov (United States)

    Jiang, Chun-Sheng; Yang, Mengjin; Zhou, Yuanyuan; To, Bobby; Nanayakkara, Sanjini U; Luther, Joseph M; Zhou, Weilie; Berry, Joseph J; van de Lagemaat, Jao; Padture, Nitin P; Zhu, Kai; Al-Jassim, Mowafak M

    2015-09-28

    Organometal-halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells-which are the fundamental mechanisms of device operation and critical factors for power output-by determining the junction structure across the device using the nanoelectrical characterization technique of Kelvin probe force microscopy. The distribution of electrical potential across both planar and porous devices demonstrates p-n junction structure at the TiO2/perovskite interfaces and minority-carrier diffusion/drift operation of the devices, rather than the operation mechanism of either an excitonic cell or a p-i-n structure. Combining the potential profiling results with solar cell performance parameters measured on optimized and thickened devices, we find that carrier mobility is a main factor that needs to be improved for further gains in efficiency of the perovskite solar cells.

  8. Molecularly designed lipid microdomains for solid dispersions using a polymer/inorganic carrier matrix produced by hot-melt extrusion.

    Science.gov (United States)

    Adler, Camille; Schönenberger, Monica; Teleki, Alexandra; Kuentz, Martin

    2016-02-29

    Amorphous solid dispersions have for many years been a focus in oral formulations, especially in combination with a hot-melt extrusion process. The present work targets a novel approach with a system based on a fatty acid, a polymer and an inorganic carrier. It was intended to adsorb the acidic lipid by specific molecular interactions onto the solid carrier to design disorder in the alkyl chains of the lipid. Such designed lipid microdomains (DLM) were created as a new microstructure to accommodate a compound in a solid dispersion. Vibrational spectroscopy, X-ray powder diffraction, atomic force microscopy as well as electron microscopic imaging were employed to study a system of stearic acid, hydroxypropylcellulose and aluminum magnesium silicate. β-carotene was used as a poorly water-soluble model substance that is difficult to formulate with conventional solid dispersion formulations. The results indicated that the targeted molecular excipient interactions indeed led to DLMs for specific compositions. The different methods provided complementary aspects and important insights into the created microstructure. The novel delivery system appeared to be especially promising for the formulation of oral compounds that exhibit both high crystal energy and lipophilicity.

  9. Suppression of thermal carrier escape and efficient photo-carrier generation by two-step photon absorption in InAs quantum dot intermediate-band solar cells using a dot-in-well structure

    Energy Technology Data Exchange (ETDEWEB)

    Asahi, S.; Teranishi, H.; Kasamatsu, N.; Kada, T.; Kaizu, T.; Kita, T. [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-08-14

    We investigated the effects of an increase in the barrier height on the enhancement of the efficiency of two-step photo-excitation in InAs quantum dot (QD) solar cells with a dot-in-well structure. Thermal carrier escape of electrons pumped in QD states was drastically reduced by sandwiching InAs/GaAs QDs with a high potential barrier of Al{sub 0.3}Ga{sub 0.7}As. The thermal activation energy increased with the introduction of the barrier. The high potential barrier caused suppression of thermal carrier escape and helped realize a high electron density in the QD states. We observed efficient two-step photon absorption as a result of the high occupancy of the QD states at room temperature.

  10. Synchronization of Fractional-order Chaotic Systems with Gaussian fluctuation by Sliding Mode Control

    OpenAIRE

    Yong Xu; Hua Wang

    2013-01-01

    This paper is devoted to the problem of synchronization between fractional-order chaotic systems with Gaussian fluctuation by the method of fractional-order sliding mode control. A fractional integral (FI) sliding surface is proposed for synchronizing the uncertain fractional-order system, and then the sliding mode control technique is carried out to realize the synchronization of the given systems. One theorem about sliding mode controller is presented to prove the proposed controller can ma...

  11. Separation of proteins from human plasma by sample displacement chromatography in hydrophobic interaction mode

    OpenAIRE

    Josic, Djuro; Breen, Lucas; Clifton, James; Gajdosik, Martina Srajer; Gaso-Sokac, Dajana; Rucevic, Marijana; Müller, Egbert

    2012-01-01

    Sample displacement chromatography (SDC) in reversed-phase and ion-exchange modes was introduced approximately twenty years ago. This method was first used for the preparative purification of peptides and proteins. Recently, SDC in ion-exchange mode was also successfully used for enrichment of low abundance proteins from human plasma. In this paper, the use of SDC for the separation of plasma proteins in hydrophobic interaction mode is demonstrated. By use of two or more columns coupled in se...

  12. Aligned Structures of Fe3O4 Nanoparticles in a Curable Polymer Carrier Induced by a Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    FANG Wen-Xiao; HE Zhen-Hui; XU Xue-Qing; SHEN Hui

    2005-01-01

    @@ To understand the interaction in dipolar systems, it is necessary to investigate the structures formed by the interacting particles. We introduce a polymer acrylic resin carrier to fix the structures in the magnetic fluid(Fe3O4). An aligned structure is investigated, which is formed under a magnetic field, and fixed in the cured acrylic resin film by evaporating the solvent at room temperature. The aligned structure is confirmed with the help of optical microscopy and optical diffraction for the cured film. Furthermore, we find substructures by using a scanning electronic microscope. Based on the curable and observable structures, a platform can be developed for investigating the aligned structures and configurations dominant by dipolar interaction. This is also helpful for the development of magnetic devices with orderly aligned structures.

  13. Baseline projections of transportation energy consumption by mode: 1981 update

    Energy Technology Data Exchange (ETDEWEB)

    Millar, M; Bunch, J; Vyas, A; Kaplan, M; Knorr, R; Mendiratta, V; Saricks, C

    1982-04-01

    A comprehensive set of activity and energy-demand projections for each of the major transportation modes and submodes is presented. Projections are developed for a business-as-usual scenario, which provides a benchmark for assessing the effects of potential conservation strategies. This baseline scenario assumes a continuation of present trends, including fuel-efficiency improvements likely to result from current efforts of vehicle manufacturers. Because of anticipated changes in fuel efficiency, fuel price, modal shifts, and a lower-than-historic rate of economic growth, projected growth rates in transportation activity and energy consumption depart from historic patterns. The text discusses the factors responsible for this departure, documents the assumptions and methodologies used to develop the modal projections, and compares the projections with other efforts.

  14. Atomic nuclei decay modes by spontaneous emission of heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.

    1985-08-01

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

  15. Circumferential resonance modes of solid elastic cylinders excited by obliquely incident acoustic waves.

    Science.gov (United States)

    Fan, Ying; Honarvar, Farhang; Sinclair, Anthony N; Jafari, Mohammad-Reza

    2003-01-01

    When an immersed solid elastic cylinder is insonified by an obliquely incident plane acoustic wave, some of the resonance modes of the cylinder are excited. These modes are directly related to the incidence angle of the insonifying wave. In this paper, the circumferential resonance modes of such immersed elastic cylinders are studied over a large range of incidence angles and frequencies and physical explanations are presented for singular features of the frequency-incidence angle plots. These features include the pairing of one axially guided mode with each transverse whispering gallery mode, the appearance of an anomalous pseudo-Rayleigh in the cylinder at incidence angles greater than the Rayleigh angle, and distortional effects of the longitudinal whispering gallery modes on the entire resonance spectrum of the cylinder. The physical explanations are derived from Resonance Scattering Theory (RST), which is employed to determine the interior displacement field of the cylinder and its dependence on insonification angle.

  16. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  17. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaojin [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-12-21

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

  18. Nanoscale dielectric microscopy of non-planar samples by lift-mode electrostatic force microscopy.

    Science.gov (United States)

    Van Der Hofstadt, M; Fabregas, R; Biagi, M C; Fumagalli, L; Gomila, G

    2016-10-01

    Lift-mode electrostatic force microscopy (EFM) is one of the most convenient imaging modes to study the local dielectric properties of non-planar samples. Here we present the quantitative analysis of this imaging mode. We introduce a method to quantify and subtract the topographic crosstalk from the lift-mode EFM images, and a 3D numerical approach that allows for extracting the local dielectric constant with nanoscale spatial resolution free from topographic artifacts. We demonstrate this procedure by measuring the dielectric properties of micropatterned SiO2 pillars and of single bacteria cells, thus illustrating the wide applicability of our approach from materials science to biology.

  19. Nanoscale dielectric microscopy of non-planar samples by lift-mode electrostatic force microscopy

    Science.gov (United States)

    Van Der Hofstadt, M.; Fabregas, R.; Biagi, M. C.; Fumagalli, L.; Gomila, G.

    2016-10-01

    Lift-mode electrostatic force microscopy (EFM) is one of the most convenient imaging modes to study the local dielectric properties of non-planar samples. Here we present the quantitative analysis of this imaging mode. We introduce a method to quantify and subtract the topographic crosstalk from the lift-mode EFM images, and a 3D numerical approach that allows for extracting the local dielectric constant with nanoscale spatial resolution free from topographic artifacts. We demonstrate this procedure by measuring the dielectric properties of micropatterned SiO2 pillars and of single bacteria cells, thus illustrating the wide applicability of our approach from materials science to biology.

  20. Broadband robustly single-mode hollow-core PCF by resonant filtering of higher-order modes.

    Science.gov (United States)

    Uebel, Patrick; Günendi, Mehmet C; Frosz, Michael H; Ahmed, Goran; Edavalath, Nitin N; Ménard, Jean-Michel; Russell, Philip St J

    2016-05-01

    We report a hollow-core photonic crystal fiber that is engineered so as to strongly suppress higher-order modes, i.e., to provide robust LP01 single-mode guidance in all the wavelength ranges where the fiber guides with low loss. Encircling the core is a single ring of nontouching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes. We show that the resulting modal filtering effect depends on only one dimensionless shape parameter, akin to the well-known d/Λ parameter for endlessly single-mode solid-core PCF. Fabricated fibers show higher-order mode losses some ∼100 higher than for the LP01 mode, with LP01 losses 110  THz bandwidth.

  1. Molecular pathogenesis of EBV susceptibility in XLP as revealed by analysis of female carriers with heterozygous expression of SAP.

    Directory of Open Access Journals (Sweden)

    Umaimainthan Palendira

    2011-11-01

    Full Text Available X-linked lymphoproliferative disease (XLP is a primary immunodeficiency caused by mutations in SH2D1A which encodes SAP. SAP functions in signalling pathways elicited by the SLAM family of leukocyte receptors. A defining feature of XLP is exquisite sensitivity to infection with EBV, a B-lymphotropic virus, but not other viruses. Although previous studies have identified defects in lymphocytes from XLP patients, the unique role of SAP in controlling EBV infection remains unresolved. We describe a novel approach to this question using female XLP carriers who, due to random X-inactivation, contain both SAP(+ and SAP(- cells. This represents the human equivalent of a mixed bone marrow chimera in mice. While memory CD8(+ T cells specific for CMV and influenza were distributed across SAP(+ and SAP(- populations, EBV-specific cells were exclusively SAP(+. The preferential recruitment of SAP(+ cells by EBV reflected the tropism of EBV for B cells, and the requirement for SAP expression in CD8(+ T cells for them to respond to Ag-presentation by B cells, but not other cell types. The inability of SAP(- clones to respond to Ag-presenting B cells was overcome by blocking the SLAM receptors NTB-A and 2B4, while ectopic expression of NTB-A on fibroblasts inhibited cytotoxicity of SAP(- CD8(+ T cells, thereby demonstrating that SLAM receptors acquire inhibitory function in the absence of SAP. The innovative XLP carrier model allowed us to unravel the mechanisms underlying the unique susceptibility of XLP patients to EBV infection in the absence of a relevant animal model. We found that this reflected the nature of the Ag-presenting cell, rather than EBV itself. Our data also identified a pathological signalling pathway that could be targeted to treat patients with severe EBV infection. This system may allow the study of other human diseases where heterozygous gene expression from random X-chromosome inactivation can be exploited.

  2. Molecular pathogenesis of EBV susceptibility in XLP as revealed by analysis of female carriers with heterozygous expression of SAP.

    Science.gov (United States)

    Palendira, Umaimainthan; Low, Carol; Chan, Anna; Hislop, Andrew D; Ho, Edwin; Phan, Tri Giang; Deenick, Elissa; Cook, Matthew C; Riminton, D Sean; Choo, Sharon; Loh, Richard; Alvaro, Frank; Booth, Claire; Gaspar, H Bobby; Moretta, Alessandro; Khanna, Rajiv; Rickinson, Alan B; Tangye, Stuart G

    2011-11-01

    X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency caused by mutations in SH2D1A which encodes SAP. SAP functions in signalling pathways elicited by the SLAM family of leukocyte receptors. A defining feature of XLP is exquisite sensitivity to infection with EBV, a B-lymphotropic virus, but not other viruses. Although previous studies have identified defects in lymphocytes from XLP patients, the unique role of SAP in controlling EBV infection remains unresolved. We describe a novel approach to this question using female XLP carriers who, due to random X-inactivation, contain both SAP(+) and SAP(-) cells. This represents the human equivalent of a mixed bone marrow chimera in mice. While memory CD8(+) T cells specific for CMV and influenza were distributed across SAP(+) and SAP(-) populations, EBV-specific cells were exclusively SAP(+). The preferential recruitment of SAP(+) cells by EBV reflected the tropism of EBV for B cells, and the requirement for SAP expression in CD8(+) T cells for them to respond to Ag-presentation by B cells, but not other cell types. The inability of SAP(-) clones to respond to Ag-presenting B cells was overcome by blocking the SLAM receptors NTB-A and 2B4, while ectopic expression of NTB-A on fibroblasts inhibited cytotoxicity of SAP(-) CD8(+) T cells, thereby demonstrating that SLAM receptors acquire inhibitory function in the absence of SAP. The innovative XLP carrier model allowed us to unravel the mechanisms underlying the unique susceptibility of XLP patients to EBV infection in the absence of a relevant animal model. We found that this reflected the nature of the Ag-presenting cell, rather than EBV itself. Our data also identified a pathological signalling pathway that could be targeted to treat patients with severe EBV infection. This system may allow the study of other human diseases where heterozygous gene expression from random X-chromosome inactivation can be exploited.

  3. Gigabit close-proximity wireless connections supported by 60 GHz RoF links with low carrier suppression

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Pang, Xiaodan; Vegas Olmos, Juan José

    2013-01-01

    We present an experimental investigation of the 60 GHz optical carrier suppressed radio over fiber systems with less than 5 dB carrier suppression. As a case study, the 60 GHz RoF signal is generated using a 12.5 Gb/s commercially available Mach-Zehnder modulator biased at its minimum point. We...

  4. Improving urban freight transport sustainability by carriers - Best practices from The Netherlands and the EU project CityLog

    NARCIS (Netherlands)

    Quak, H.J.

    2012-01-01

    Carriers face serious challenges in making their urban freight transport efficient and sustainable. Local authorities claim that many carriers are not innovative and do not cooperate in improving their city logistics operations. There are three solution directions to make urban freight transport mor

  5. Free-carrier generation in aggregates of single-wall carbon nanotubes by photoexcitation in the ultraviolet regime.

    Science.gov (United States)

    Crochet, Jared J; Hoseinkhani, Sajjad; Lüer, Larry; Hertel, Tobias; Doorn, Stephen K; Lanzani, Guglielmo

    2011-12-16

    We present evidence for the generation of free carriers in aggregated single-wall carbon nanotubes by photoexcitation in the energetic range of the π→π(*) transition associated with the M saddle point of the graphene lattice. The underlying broad absorption culminating at 4.3 eV can be fit well with a Fano line shape that describes strong coupling of a saddle-point exciton to an underlying free electron-hole pair continuum. Moreover, it is demonstrated that transitions in this energetic region autoionize into the continuum by detecting features unique to the presence of free charges in the transient transmission spectra of the continuum-embedded second sub-band exciton, S(2).

  6. InGaAsP-based uni-travelling carrier photodiode structure grown by solid source molecular beam epitaxy.

    Science.gov (United States)

    Natrella, Michele; Rouvalis, Efthymios; Liu, Chin-Pang; Liu, Huiyun; Renaud, Cyril C; Seeds, Alwyn J

    2012-08-13

    We report the first InGaAsP-based uni-travelling carrier photodiode structure grown by Solid Source Molecular Beam Epitaxy; the material contains layers of InGaAsP as thick as 300 nm and a 120 nm thick InGaAs absorber. Large area vertically illuminated test devices have been fabricated and characterised; the devices exhibited 0.1 A/W responsivity at 1550 nm, 12.5 GHz -3 dB bandwidth and -5.8 dBm output power at 10 GHz for a photocurrent of 4.8 mA. The use of Solid Source Molecular Beam Epitaxy enables the major issue associated with the unintentional diffusion of zinc in Metal Organic Vapour Phase Epitaxy to be overcome and gives the benefit of the superior control provided by MBE growth techniques without the costs and the risks of handling toxic gases of Gas Source Molecular Beam Epitaxy.

  7. Correlation between Defect Concentration and Carrier Lifetime of GaAs Grown by Molecular Beam Epitaxy at Different Temperatures

    Science.gov (United States)

    Lin, Gong-Ru; Liu, Tze-An; Pan, Ci-Ling

    2001-11-01

    A pump-probe study of GaAs grown by molecular beam epitaxy at low temperatures (LT-GaAs) is performed. Ultrashort carrier lifetimes of the as-grown LT-GaAs increase from Schokley-Read-Hall model. The decreasing trend in the amplitudes of continuous-wave and transient reflectivities (Δ R/R) as a function of the growth temperature for the LT-GaAs is explained as an induced absorption caused by dense arsenic antisite defects. The sign of the transient Δ R/R reversed for LT-GaAs grown at 200°C. This is tentatively attributed to the band gap renormalization effect.

  8. Classifications within Molecular Subtypes Enables Identification of BRCA1/BRCA2 Mutation Carriers by RNA Tumor Profiling

    DEFF Research Database (Denmark)

    Larsen, Martin Jakob; Kruse, Torben A; Tan, Qihua;

    2013-01-01

    Pathogenic germline mutations in BRCA1 or BRCA2 are detected in less than one third of families with a strong history of breast cancer. It is therefore expected that mutations still remain undetected by currently used screening methods. In addition, a growing number of BRCA1/2 sequence variants...... of unclear pathogen significance are found in the families, constituting an increasing clinical challenge. New methods are therefore needed to improve the detection rate and aid the interpretation of the clinically uncertain variants. In this study we analyzed a series of 33 BRCA1, 22 BRCA2, and 128 sporadic...... tumors by RNA profiling to investigate the classification potential of RNA profiles to predict BRCA1/2 mutation status. We found that breast tumors from BRCA1 and BRCA2 mutation carriers display characteristic RNA expression patterns, allowing them to be distinguished from sporadic tumors. The majority...

  9. Tunable defect modes in 2D photonic crystals by means of external magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Soltani Vala, A., E-mail: asoltani@tabrizu.ac.i [Physics Department, University of Tabriz, Tabriz (Iran, Islamic Republic of); Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz (Iran, Islamic Republic of); Rezaei, B. [Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz (Iran, Islamic Republic of); Kalafi, M. [Physics Department, University of Tabriz, Tabriz (Iran, Islamic Republic of); Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2010-07-15

    We investigate the tunable defect modes in 2D photonic crystal of silicon rods in air background in which one of the rods is replaced by ferrite material and an external static magnetic field is applied in the ferrite rod direction. Using the supercell method, the dependence of E-polarized defect modes on the magnetic field has been reported.

  10. All-fiber passively mode-locked Ho-laser pumped by ytterbium fiber laser

    Science.gov (United States)

    Filatova, S. A.; Kamynin, V. A.; Zhluktova, I. V.; Trikshev, A. I.; Tsvetkov, V. B.

    2016-11-01

    We report an all-fiber mode-lock holmium-doped ring laser passively mode-locked by nonlinear polarization rotation without dispersion compensation. The laser produced picosecond pulses at 2.057 µm. The average output power was 4.5 mW.

  11. Mode suppression in the non-Markovian limit by time-gated stimulated photon echo

    NARCIS (Netherlands)

    de Boeij, W.P.; Pshenichnikov, M.S; Wiersma, D. A.

    1996-01-01

    It is demonstrated that enhanced mode suppression in stimulated photon echo experiments can be obtained by diagonal time gating of the echo. This technique is especially important when the optical dynamics of the system is non-Markovian. A two-mode Brownian oscillator model is used to analyze the ef

  12. Perceptual space induced by cochlear implant all-polar stimulation mode

    DEFF Research Database (Denmark)

    Marozeau, Jeremy; Mckay, Colette M.

    2015-01-01

    It has often been argued that a main limitation of the cochlear implant is the spread of current induced by each electrode, which activates an inappropriately large range of sensory neurons. In order to reduce this spread, a new stimulation mode, the all-polar mode, was tested with 5 participants...

  13. Passive mode locking of lasers by crossed-polarization gain modulation.

    Science.gov (United States)

    Javaloyes, Julien; Mulet, Josep; Balle, Salvador

    2006-10-20

    We report on a novel approach for inducing passive mode locking of lasers without using any saturable absorber but exploiting the polarization degree of freedom of light. In our scheme, passive mode locking is achieved by crossed-polarization gain modulation caused by the reinjection of a polarization-rotated replica of the laser output after a time delay. The reinjection time delay defines resonance tongues that correspond to mode-locking operation. Numerical continuation reveals that the cw solution is destabilized through a Hopf bifurcation that defines the onset of multimode operation which evolves sharply into a mode-locked solution. Our approach can be applied to a large variety of laser systems. For vertical-cavity surface-emitting lasers, we demonstrate stable mode-locked pulses at repetition rates in the GHz range and pulse widths of few tens of picoseconds.

  14. Simultaneous quantitative evaluation of in-plane and out-of-plane deformation by use of a carrier method of large image-shearing shearography

    Institute of Scientific and Technical Information of China (English)

    Ping Sun; Ruijin Liu; Qing Han; Xiaofeng Wang

    2006-01-01

    A carrier method for separating out-of-plane displacement from in-plane components based on large imageshearing shearography is presented. A reference surface is fixed on the side of a test object. They are illuminated by two expanded symmetric illuminations respectively. The carrier is introduced by rotating the reference surface to modulate the displacement of an object. By using Fourier transform to demodulate the modulated fringe pattern, two phase maps, which include out-of-plane and in-plane displacements, can be obtained. Then the out-of-plane displacement can be easily separated from in-plane displacement by subtraction and addition of the two unwrapped phase distributions. The principle of the method is presented and proved by a typical three-point-bending experiment. Experimental results show that the method enjoys high visibility of carrier fringes. The system does not need a special beam as a reference light and has simple optical setup.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, Richard [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712-1203 (United States)

    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.

  16. Is there any exposure from a mobile phone in stand-by mode?

    DEFF Research Database (Denmark)

    Mild, Kjell Hansson; Andersen, Jørgen Bach; Pedersen, Gert Frølund

    2012-01-01

    Several studies have been using a GSM mobile phone in stand-by mode as the source for exposure, and they claimed that this caused effects on for instance sleep and testicular function. In stand-by mode the phone is only active in periodic location updates, and this occurs with a frequency set...... by the net operator. Typical updates occur with 2-5 h in between, and between these updates the phone is to be considered as a passive radio receiver with no microwave emission. Thus, the exposure in stand-by mode can be considered negligible....

  17. TEM00 mode Nd:YAG solar laser by side-pumping a grooved rod

    Science.gov (United States)

    Vistas, Cláudia R.; Liang, Dawei; Almeida, Joana; Guillot, Emmanuel

    2016-05-01

    A simple TEM00 mode solar laser system with a grooved Nd:YAG rod pumped through a heliostat-parabolic mirror system is reported here. The radiation coupling capacity of a fused silica tube lens was combined with the multipass pumping ability of a 2 V-shaped cavity to provide efficient side-pumping along a 4.0 mm diameter grooved Nd:YAG single-crystal rod. TEM00 mode solar laser power of 3.4 W was measured by adopting an asymmetric large-mode laser resonant cavity. Record TEM00 mode solar laser collection efficiency of 3.4 W/m2and slope efficiency of 1.9% was achieved, which corresponds to 1.8 and 2.4 times more than the previous TEM00 mode Nd:YAG solar laser using the PROMES-CNRS heliostat-parabolic mirror system, respectively.

  18. Study of the Mode of Cost-sharing by Individuals for Higher Education in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In recent years, financial crises of higher education have become universal. The policy of cost-sharing by individuals was tried out in many countries. However, empirical studies have shown that the policy has, to a certain degree, negative effects for the poor in accepting higher education costs. This paper points out it is the mismatch between tuition fees and the ability to pay that causes the problem. Using two dimensions of group and time to pay, a mode system, including seven modes for the individual to share the cost of higher education, was constructed. It is suggested that only three modes of pay-immediately have been carried out in China and they all have same shortcomings. To try new modes and exercise different modes synthetically will be meaningful for solving the questions that exist in the current policy.

  19. Retarding viscous Rayleigh-Taylor mixing by an optimized additional mode

    Science.gov (United States)

    Xie, C. Y.; Tao, J. J.; Sun, Z. L.; Li, J.

    2017-02-01

    The Rayleigh-Taylor (RT) mixing induced by random interface disturbances between two incompressible viscous fluids is simulated numerically. The ensemble averaged spike velocity is found to be remarkably retarded when the random interface disturbances are superimposed with an optimized additional mode. The mode's wavenumber is selected to be large enough to avoid enhancing the dominance of long-wavelength modes, but not so large that its saturated spike and bubble velocities are too small to stimulate a growing effective density-gradient layer suppressing the long-wavelength modes. Such an optimized suppressing mode is expected to be found in the RT mixing including other diffusion processes, e.g., concentration diffusion and thermal diffusion.

  20. Suppression of quadrupole and octupole modes in red giants observed by Kepler

    CERN Document Server

    Stello, D; Fuller, J; Garcia, R A; Huber, D

    2016-01-01

    The asteroseismology of red giant stars has continued to yield surprises since the onset of high-precision photometry from space-based observations. An exciting new theoretical result shows that the previously observed suppression of dipole oscillation modes in red giants can be used to detect strong magnetic fields in the stellar cores. A fundamental facet of the theory is that nearly all the mode energy leaking into the core is trapped by the magnetic greenhouse effect. This results in clear predictions for how the mode visibility changes as a star evolves up the red giant branch, and how that depends on stellar mass, spherical degree, and mode lifetime. Here, we investigate the validity of these predictions with a focus on the visibility of different spherical degrees. We find that mode suppression weakens for higher degree modes with an average reduction in the quadrupole mode visibility of up to 49% for the least evolved stars in our sample, and no detectable suppression of octupole modes, in agreement w...

  1. Smooth and flat phase-locked Kerr frequency comb generation by higher order mode suppression.

    Science.gov (United States)

    Huang, S-W; Liu, H; Yang, J; Yu, M; Kwong, D-L; Wong, C W

    2016-05-16

    High-Q microresonator is perceived as a promising platform for optical frequency comb generation, via dissipative soliton formation. In order to achieve a higher quality factor and obtain the necessary anomalous dispersion, multi-mode waveguides were previously implemented in Si3N4 microresonators. However, coupling between different transverse mode families in multi-mode waveguides results in periodic disruption of dispersion and quality factor, and consequently causes perturbation to dissipative soliton formation and amplitude modulation to the corresponding spectrum. Careful choice of pump wavelength to avoid the mode crossing region is thus critical in conventional Si3N4 microresonators. Here, we report a novel design of Si3N4 microresonator in which single-mode operation, high quality factor, and anomalous dispersion are attained simultaneously. The novel microresonator is consisted of uniform single-mode waveguides in the semi-circle region, to eliminate bending induced mode coupling, and adiabatically tapered waveguides in the straight region, to avoid excitation of higher order modes. The intrinsic quality factor of the microresonator reaches 1.36 × 10(6) while the group velocity dispersion remains to be anomalous at -50 fs(2)/mm. With this novel microresonator, we demonstrate that broadband phase-locked Kerr frequency combs with flat and smooth spectra can be generated by pumping at any resonances in the optical C-band.

  2. Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

    Science.gov (United States)

    Abramov, Arnold; Kostikov, Alexander

    2017-03-01

    We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder.

  3. Prevalence of Haemophilus influenzae carriers in the Catalan preschool population. Working Group on Invasive Disease Caused by Haemophilus influenzae.

    Science.gov (United States)

    Fontanals, D; Bou, R; Pons, I; Sanfeliu, I; Domínguez, A; Pineda, V; Renau, J; Muñoz, C; Latorre, C; Sanchez, F

    2000-04-01

    This study was designed to determine the prevalence of healthy Haemophilus influenzae carriers in a random sample of the preschool population in Catalonia. Oropharyngeal swabs were collected and cultured on chocolate agar supplemented with 260 microg/ml of bacitracin. Four hundred two of the 734 (54.8%) children studied were detected as Haemophilus influenzae carriers: 7 (0.9%) carried serotype b, 14 (1.9%) serotype e, 6 (0.8%) serotype f, and 375 (51%) carried nontypable strains. The results show that, although the prevalence of Haemophilus influenzae carriers is similar to figures reported from other countries, the prevalence of Haemophillus influenzae serotype b carriers is lower and corresponds with the low incidence of invasive disease observed in the Catalan community.

  4. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    KAUST Repository

    Soury, Hamza

    2013-11-09

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  5. Realization of Arbitrary Inverse Unitary Transformation of Single Mode Fibre by Using Three Wave Plates

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-Kai; REN Ji-Gang; PENG Cheng-Zhi; JIANG Shuo; WANG Xiang-Bin

    2007-01-01

    We report a method to realize the arbitrary inverse unitary transformation imposed by a single-mode fibre on photon's polarization by the succession of two quarter-wave plates and a half-wave plate. The process of realization by polarization state vector. The method is meaningful in quantum communication experiment such as quantum teleportation, in which an unknown arbitrary quantum state should be kept to be unchanged in the case of using a single-mode fibre for time delay.

  6. Prevalence of Haemophilus influenzae pharyngeal carriers in the school population of Catalonia. Working Group on invasive disease caused by Haemophilus influenzae.

    Science.gov (United States)

    Bou, R; Domínguez, A; Fontanals, D; Sanfeliu, I; Pons, I; Renau, J; Pineda, V; Lobera, E; Latorre, C; Majó, M; Salleras, L

    2000-06-01

    The objective of this study was to determine the prevalence of healthy Haemophilus influenzae (Hi) pharyngeal carriers in a representative sample of the Catalonian school population, as well as the factors associated. A two-stage cluster sampling was carried out. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. A pharyngeal swab was performed on children when informed consent was given by parents, and was cultured on chocolate agar with 260 microg/ml bacitracin. Of the 1212 children studied, 316 (26%) H. influenzae carriers were detected: 5 (0.4%) serotype b, 1 (0.08%) serotype c, 6 (0.5%) serotype e, 5 (0.4%) serotype f, and 299 (24.7%) non-typable. Age, gender and geographical location were the only variables associated with H. influenzae carrier status. The prevalence of non-typable H. influenzae carriers was similar to that of studies carried out in other countries, while that of serotype b carriers was similar to the remainder of H. influenzae capsulates, and lower than that described in previous studies. These data are in accordance with the low incidence of the disease observed in our context, although the possibility that the vaccine coverage may have affected the results of this study cannot be dismissed.

  7. Determination of carrier concentration dependent electron effective mass and scattering time of n-ZnO thin film by terahertz time domain spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J.; Tay, C. B. [Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); NUSNNI-Nanocore, National University of Singapore, Singapore 117576 (Singapore); Deng, L. Y. [Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Zhang, X. H.; Chai, J. W. [Institute of Materials and Research Engineering, Agency for Science, Technology and Research, 3 Research Link, Singapore 117602 (Singapore); Qin, H. [Department of Chemical and Bioengineering, National University of Singapore, Singapore 117542 (Singapore); Liu, H. W. [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Venkatesan, T. [NUSNNI-Nanocore, National University of Singapore, Singapore 117576 (Singapore); Chua, S. J., E-mail: elecsj@nus.edu.sg [Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); NUSNNI-Nanocore, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials and Research Engineering, Agency for Science, Technology and Research, 3 Research Link, Singapore 117602 (Singapore)

    2014-01-21

    We demonstrated a novel and widely accessible method for determining the electron effective mass and scattering time of ZnO films with different carrier concentrations by combining terahertz time-domain spectroscopy with Hall measurement. The terahertz time domain spectroscopy (THz-TDS) transmission spectra (0.1–2THz) were well described by Drude model. It is found that electron effective mass varied from 0.23m{sub 0} to 0.26m{sub 0} as the electron concentration changes from 5.9 × 10{sup 17} cm{sup −3} to 4.0 × 10{sup 19} cm{sup −3}. The carrier concentration dependent characteristic is ascribed to the non-parabolicity of conduction band. Free carrier localization mechanism explained the discrepancy in mobilities obtained from THz-TDS and Hall measurements.

  8. NMR Studies of a New Binding Mode of the Amino Acid Esters by Porphyrinatozinc(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The binding mode of the amino acid ethyl esters(guest) by 5-(2-carboxylphenyl)-10,15,20-triphenylporphyrinatozinc(Ⅱ)(host 1) was studied by means of 1H NMR spectra. The binding mode is the hydrogen-bonding between the amino group of the guest and the carboxyl group of host 1 plus the coordination between the zinc atom of porphyrinatozinc(Ⅱ) and the carbonyl group of the guest. This is a novel binding mode of the metalloporphyrin to amino acid derivatives.

  9. A laboratory study of low-mode internal tide scattering by finite-amplitude topography

    CERN Document Server

    Peacock, Thomas; Didelle, Henri; Viboud, Samuel; Dauxois, Thierry

    2015-01-01

    We present the first laboratory experimental results concerning the scattering of a low-mode internal tide by a gaussian topography. Experiments performed at the Coriolis Platform in Grenoble used a recently-conceived internal wave generator as a means of producing a high-quality mode-1 wave field. The evolution of the wave field in the absence and presence of a supercritical Gaussian was studied by performing spatiotemporal modal decompositions of velocity field data obtained using Particle Image Velocimetry (PIV). The results support predictions that large-amplitude supercritical topography produces significant reflection of the internal tide and transfer of energy from low to high modes.

  10. Damage localization by statistical evaluation of signal-processed mode shapes

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Damkilde, Lars

    2015-01-01

    in the spatial mode shape signals, hereby potentially facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise....... The present article introduces a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise. The method is based on signal processing of spatial mode shapes by means of continuous wavelet transformation (CWT...

  11. Prediction of pressure induced by liquid sloshing for LNG carrier%LNG船液舱晃荡压强预报

    Institute of Scientific and Technical Information of China (English)

    朱仁庆; 马海潇; 缪泉明; 郑文涛

    2013-01-01

    A numerical technique to predict the pressure induced by liquid sloshing in a membrane tank is produced for LNG carrier based on CFD. The motion of incompressible fluid is described by Navier-Stokes equations and continuum equation. The governing equations are discretized by finite volume method and solved by Simple scheme. The profile of liquid surface is reconstructed by the volume of fluid (VOF) tech-nique. A reduced scale (1:55) tank model is used to perform the model test in China Ship Scientific Re-search Center. The numerical results including pressure and free surface profile are compared with the test ones, showing a good agreement. These comparisons show that the presented method is useful to predict the load induced by liquid sloshing for LNG carrier.%  基于CFD技术,提出了数值预报LNG船薄膜型液舱晃荡压强的方法。流体运动方程由不可压缩的连续方程和N-S动量方程描述,并采用有限体积法进行离散,通过Simple算法求解,其中液体自由表面运动采用VOF技术进行追踪并重构。在中国船舶科学研究中心,以1:55的液舱试验模型为研究对象,开展了试验研究。数值预报结果与试验结果进行了比较,结果显示测点处的压力时间历程与自由液面波形与试验值相当吻合,说明所建立的数值模型可以有效地预报LNG船液舱晃荡载荷。

  12. Controlling the efficiency of spin injection into graphene by carrier drift

    NARCIS (Netherlands)

    Jozsa, C.; Popinciuc, M.; Tombros, N.; Jonkman, H. T.; van Wees, B. J.

    2009-01-01

    Electrical spin injection from ferromagnetic metals into graphene is hindered by the impedance mismatch between the two materials. This problem can be reduced by the introduction of a thin tunnel barrier at the interface. We present room-temperature nonlocal spin valve measurements in cobalt/aluminu

  13. Structural damage localization by outlier analysis of signal-processed mode shapes - Analytical and experimental validation

    Science.gov (United States)

    Ulriksen, M. D.; Damkilde, L.

    2016-02-01

    Contrary to global modal parameters such as eigenfrequencies, mode shapes inherently provide structural information on a local level. Therefore, this particular modal parameter and its derivatives are utilized extensively for damage identification. Typically, more or less advanced mathematical methods are employed to identify damage-induced discontinuities in the spatial mode shape signals, hereby, potentially, facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise. In the present paper, a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise is proposed. The method is based on signal processing of a spatial mode shape by means of continuous wavelet transformation (CWT) and subsequent application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact damage-induced, outlier analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically and benchmarked with other mode shape-based damage localization approaches on the basis of a free-vibrating beam and validated experimentally in the context of a residential-sized wind turbine blade subjected to an impulse load.

  14. [Modification of DNA typing of blood stains by textile stain carriers].

    Science.gov (United States)

    Scheithauer, R; Weisser, H J

    1991-01-01

    Samples of 20 microliters blood were applicated von 55 different textiles, containing all usual materials for clothes, straight from the fabric and after thorough washing. DNA profiling was influenced only by blue jeans and blue terry towel straight from the fabric; in some of these samples there was an inhibition of the restriction enzyme digest that could not be prevented by an additional dialysis step.

  15. Low-cost carriers fare competition effect

    OpenAIRE

    Carmona Benitez, R.B.; Lodewijks, G.

    2010-01-01

    This paper examines the effects that low-cost carriers (LCC’s) produce when entering new routes operated only by full-service carriers (FSC’s) and routes operated by low-cost carriers in competition with full-service carriers. A mathematical model has been developed to determine what routes should be operated by a low-cost carrier with better possibilities to subsist. The proposed model in this paper was set up by analyzing The United States domestic air transport market 2005 year database fr...

  16. Demonstration of Shear Waves, Lamb Waves, and Rayleigh Waves by Mode Conversion.

    Science.gov (United States)

    Leung, W. P.

    1980-01-01

    Introduces an experiment that can be demonstrated in the classroom to show that shear waves, Rayleigh waves, and Lamb waves can be easily generated and observed by means of mode conversion. (Author/CS)

  17. Electrically Injected Single Transverse-Mode Coupled Waveguide Lasers by Parity-time (PT) Symmetry

    CERN Document Server

    Yao, Ruizhe; Podolskiy, Viktor; Guo, Wei

    2016-01-01

    In this report, we demonstrate the single transverse-mode operation of InAs quantum dot (QD) broad-area coupled waveguide lasers by parity-time (PT) symmetry. A novel waveguide design is adopted by adding gain and loss in the electrically injected coupled waveguide laser cavity. In such counterintuitive waveguide design, the single mode operation is achieved by harnessing notions from PT symmetry breaking and mode selections. By further varying the loss in the coupled waveguides, the coupled waveguide operation in different PT symmetry regions is experimentally demonstrated and agrees well with the numerical models. The demonstration of an electrically pumped single transverse-mode based on PT symmetry breaking paves a way to the next-generation optoelectronic devices and advanced laser science.

  18. Fundamental modes in waveguide pipe twisted by saturated double-well potential

    Science.gov (United States)

    Chen, Gui-Hua; Wang, Hong-Cheng; Chen, Zhao-Pin; Liu, Yan

    2017-02-01

    We study fundamental modes trapped in a rotating ring with a saturated nonlinear double-well potential. This model, which is based on the nonlinear Schrödinger equation, can be constructed in a twisted waveguide pipe in terms of light propagation, or in a Bose-Einstein condensate (BEC) loaded into a toroidal trap under a combination of a rotating π-out-of-phase linear potential and nonlinear pseudopotential induced by means of a rotating optical field and the Feshbach resonance. Three types of fundamental modes are identified in this model, one symmetric and the other two asymmetric. The shape and stability of the modes and the transitions between different modes are investigated in the first rotational Brillouin zone. A similar model used a Kerr medium to build its nonlinear potential, but we replace it with a saturated nonlinear medium. The model exhibits not only symmetry breaking, but also symmetry recovery. A specific type of unstable asymmetric mode is also found, and the evolution of the unstable asymmetric mode features Josephson oscillation between two linear wells. By considering the model as a configuration of a BEC system, the ground state mode is identified among these three types, which characterize a specific distribution of the BEC atoms around the trap.

  19. Vibration Mode Observation of Piezoelectric Disk-type Resonator by High Frequency Laser Doppler Vibrometer

    Science.gov (United States)

    Matsumura, Takeshi; Esashi, Masayoshi; Harada, Hiroshi; Tanaka, Shuji

    For future mobile phones based on cognitive radio technology, a compact multi-band RF front-end architecture is strongly required and an integrated multi-band RF filter bank is a key component in it. Contour-mode resonators are receiving increased attention for a multi-band filter solution, because its resonant frequency is mainly determined by its size and shape, which are defined by lithography. However, spurious responses including flexural vibration are also excited due to its thin structure. To improve resonator performance and suppress spurious modes, visual observation with a laser probe system is very effective. In this paper, we have prototyped a mechanically-coupled disk-array filter, which consists of a Si disk and 2 disk-type resonators of higher-order wine-glass mode, and observed its vibration modes using a high-frequency laser-Doppler vibrometer (UHF-120, Polytec, Inc.). As a result, it was confirmed that higher order wine-glass mode vibration included a compound displacement, and that its out-of-plane vibration amplitude was much smaller than other flexural spurious modes. The observed vibration modes were compared with FEM (Finite Element Method) simulation results. In addition, it was also confirmed that the fabrication error, e.g. miss-alignment, induced asymmetric vibration.

  20. Modeling one-mode projection of bipartite networks by tagging vertex information

    Science.gov (United States)

    Qiao, Jian; Meng, Ying-Ying; Chen, Hsinchun; Huang, Hong-Qiao; Li, Guo-Ying

    2016-09-01

    Traditional one-mode projection models are less informative than their original bipartite networks. Hence, using such models cannot control the projection's structure freely. We proposed a new method for modeling the one-mode projection of bipartite networks, which thoroughly breaks through the limitations of the available one-mode projecting methods by tagging the vertex information of bipartite networks in their one-mode projections. We designed a one-mode collaboration network model by using the method presented in this paper. The simulation results show that our model matches three real networks very well and outperforms the available collaboration network models significantly, which reflects the idea that our method is ideal for modeling one-mode projection models of bipartite graphs and that our one-mode collaboration network model captures the crucial mechanisms of the three real systems. Our study reveals that size growth, individual aging, random collaboration, preferential collaboration, transitivity collaboration and multi-round collaboration are the crucial mechanisms of collaboration networks, and the lack of some of the crucial mechanisms is the main reason that the other available models do not perform as well as ours.

  1. 77 FR 38747 - Reports by Air Carriers on Incidents Involving Animals During Air Transport

    Science.gov (United States)

    2012-06-29

    ... information provided. Privacy Act: Anyone is able to search the electronic form of all comments received in... household pets reported to DOT by airlines have involved cats and dogs. Second, the legislative history of... per year. This is based on our estimate of a Paralegal's salary discussed above. Various trade...

  2. Reducing dephasing in coupled quantum dot-cavity systems by engineering the carrier wavefunctions

    DEFF Research Database (Denmark)

    Nysteen, Anders; Nielsen, Per Kær; Mørk, Jesper

    2012-01-01

    We demonstrate theoretically how photon-assisted dephasing by the electron-phonon interaction in a coupled cavity-quantum dot system can be significantly reduced for specific QD-cavity detunings. Our starting point is a recently published theory,1 which considers longitudinal acoustic phonons, de...

  3. PCR-heteroduplex by grouping: Rapid screening carrier method for cystic fibrosis F508del mutation in Colombia.

    Directory of Open Access Journals (Sweden)

    Lina Manuela Jay

    2009-11-01

    Full Text Available Background: Cystic fibrosis (CF is the most frequent autosomal recessive disorder in the Caucasian population with an incidence of 1 in 2,500 newborns. More than 1,300 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR gene that causes CF have been described. However, mutation F508del is the most common mutation in different populations around the world. Objective: To develop a fast, reliable and low-cost technique to screen carriers and affected individuals for the F508del mutation. This kind of analysis will have an impact on genetic counselling to decrease the incidence of new cases, in the early diagnosis and instauration of appropriate treatment to decrease morbidity and mortality associated to CF in Colombia. Methods: The reliability of the PCR-heteroduplex by grouping technique by analysis of 400 blood spot samples from asymptomatic CF patients was defined. Results: Using PCR-heteroduplex by grouping technique 100% efficiency, reproducibility and specificity and 92%sensitivity were found. Conclusions: The sensitivity and reproducibility of the PCR-heteroduplex by grouping technique up to pooling of 10 samples were demonstrated. This kind of analysis could be used in heterozygotes and affected screening programs.

  4. Depth profiling of strain and carrier concentration by cleaved surface scanning of GaN Gunn-diode: confocal Raman microscopy

    Science.gov (United States)

    Belyaev, A. E.; Strelchuk, V. V.; Nikolenko, A. S.; Romanyuk, A. S.; Mazur, Yu I.; Ware, M. E.; DeCuir, E. A., Jr.; Salamo, G. J.

    2013-10-01

    Confocal micro-Raman spectroscopy was applied to study the cleaved surface of vertical GaN Gunn-diode structure grown by molecular-beam epitaxy. The analysis of lateral scanning along the cleaved edge reveals the depth profile of elastic strain, quality of the crystal structure, and the concentration of charge carriers. Results are compared with that of axial confocal Raman depth profiling normal to the structure's surface. Decrease of compressive strain near the cleaved edge in the direction from the substrate to the structure's surface and in the growth plane towards the cleaved edge is shown. The decrease in charge carrier concentration in the undoped n0-GaN channel region in comparison with the n+-GaN contact region is identified. Peculiarities of the resulting spatial profiles of free charge carriers and their correlation with the initial doping profile are discussed.

  5. Optical Properties and Carrier Dynamics of GaAs/GaInAs Multiple-Quantum-Well Shell Grown on GaAs Nanowire by Molecular Beam Epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwangwook; Ravindran, Sooraj; Ju, Gun Wu; Min, Jung-Wook; Kang, Seokjin; Myoung, NoSoung; Yim, Sang-Youp; Jo, Yong-Ryun; Kim, Bong-Joong; Lee, Yong Tak

    2016-12-01

    GaAs/GaInAs multiple-quantum-well (MQW) shells having different GaInAs shell width formed on the surface of self-catalyzed GaAs core nanowires (NWs) are grown on (100) Si substrate using molecular beam epitaxy. The photoluminescence emission from GaAs/GaInAs MQW shells and the carrier lifetime could be varied by changing the width of GaInAs shell. Time-resolved photoluminescence measurements showed that the carrier lifetime had a fast and slow decay owing to the mixing of wurtzite and zinc-blende structures of the NWs. Furthermore, strain relaxation caused the carrier lifetime to decrease beyond a certain thickness of GaInAs quantum well shells.

  6. Toward 3D MHD modeling of neoclassical tearing mode suppression by ECCD

    Directory of Open Access Journals (Sweden)

    Westerhof E.

    2012-09-01

    Full Text Available We propose a framework to extend the magnetohydrodynamic (MHD equations to include electron cyclotron current drive (ECCD and discuss previous models proposed by Giruzzi et al. [2] and by Hegna and Callen [3]. To model neoclassical tearing mode (NTM instabilities and study the growth of magnetic islands as NTMs evolve, we employ the nonlinear reduced-MHD simulation JOREK. We present tearing-mode growth-rate calculations from JOREK simulations.

  7. A possible mode of the specifi-crecognition of nucleic acids by proteins

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Seven sets of protein target sites, which occur in several gene promoters, have been analyzed. The results suggest that there is a possible mode of specific recognition of double-helical nucleic acids by proteins. This recognition mode is related to a special topological property of double-helical DNA, which is termed base spatial pattern (BSP) of DNA segment. BSP is the spatial topological property determined only by the spatial arrangement of the bases on double-helical DNA segment.

  8. Effect of carrier tunneling on the structure of Si nanowires fabricated by metal assisted etching

    Science.gov (United States)

    Rezvani, S. J.; Gunnella, R.; Neilson, D.; Boarino, L.; Croin, L.; Aprile, G.; Fretto, M.; Rizzi, P.; Antonioli, D.; Pinto, N.

    2016-08-01

    The metal assisted etching mechanism for Si nanowire fabrication, triggered by doping type and level and coupled with choice of metal catalyst, is still very poorly understood. We explain the different etching rates and porosities of wires we observe based on extensive experimental data, using a new empirical model we have developed. We establish as a key parameter, the tunneling through the space charge region (SCR) which is the result of the reduction of the SCR width by level of the Si wafer doping in the presence of the opposite biases of the p- and n-type wafers. This improved understanding should permit the fabrication of high quality wires with predesigned structural characteristics, which hitherto has not been possible.

  9. Surfactant-laden drop jellyfish-breakup mode induced by the Marangoni effect

    Science.gov (United States)

    Zhao, Hui; Zhang, Wen-Bin; Xu, Jian-Liang; Li, Wei-Feng; Liu, Hai-Feng

    2017-03-01

    Drop breakup is a familiar event in both nature and technology. In this study, we find that the bag breakup mode can be replaced by a new breakup mode: jellyfish breakup, when the surfactant concentration of a surfactant-laden drop is high. This new breakup mode has a morphology resembling a jellyfish with many long tentacles. This is due to the inhomogeneous distribution of surfactant in the process of drop deformation and breakup. The thin film of liquid can remain stable as a result of the Marangoni effect. Finally, we propose that the dimensionless surfactant concentration can serve as a criterion for breakup mechanisms.

  10. Improvement of out-of-band Behaviour in Switch-Mode Amplifiers and Power Supplies by their Modulation Topology

    DEFF Research Database (Denmark)

    Knott, Arnold

    2010-01-01

    problem where four different approaches: • Multi Carrier Modulation (MCM) • Active Electromagnetic Cancellation (AEC) • Current Driven Power Stages (CDP) • Radio Frequency Power Electronics (RF SMPS) Multi Carrier Modulation (chapter 4) is using more than one external carrier and generating multiple PWM...... signals. Those are combined by a logic circuit to one pulse coded information stream. The average of this stream is proportional to the modulated signal, while the spectral peaks of the switching frequencies are half compared to state-of-the art pulse width modulation (PWM). Active Electromagnetic...

  11. A strong diffusive ion mode in dense ionized matter predicted by Langevin dynamics.

    Science.gov (United States)

    Mabey, P; Richardson, S; White, T G; Fletcher, L B; Glenzer, S H; Hartley, N J; Vorberger, J; Gericke, D O; Gregori, G

    2017-01-30

    The state and evolution of planets, brown dwarfs and neutron star crusts is determined by the properties of dense and compressed matter. Due to the inherent difficulties in modelling strongly coupled plasmas, however, current predictions of transport coefficients differ by orders of magnitude. Collective modes are a prominent feature, whose spectra may serve as an important tool to validate theoretical predictions for dense matter. With recent advances in free electron laser technology, X-rays with small enough bandwidth have become available, allowing the investigation of the low-frequency ion modes in dense matter. Here, we present numerical predictions for these ion modes and demonstrate significant changes to their strength and dispersion if dissipative processes are included by Langevin dynamics. Notably, a strong diffusive mode around zero frequency arises, which is not present, or much weaker, in standard simulations. Our results have profound consequences in the interpretation of transport coefficients in dense plasmas.

  12. Prophylaxis and Treatment of Influenza A Virus Infection by Carrier-Mediated Passive Immunity

    Science.gov (United States)

    1991-01-01

    Fogler , W.E., Kirsh, R. and Poste, G., "Activation of Tumoricidal Properties in Macrophages by Liposome-encapsulated Lymphokines: In Vivo Studies", Tom...pp 124-128. 19. Fidler, I.J., Raz, A., Fogler , W.E., Kirsch, R., Bugelski, P., and Poste, G., "Design of Liposomes to Improve Delivery of Macrophage...Augmenting Agents to Alveolar Macrophages", Cancer Res., 40 (1980) pp. 4460-4466. 20. Post, G., Kirsch, R., Raz, A., Sone., S., Bucana, C., Fogler

  13. Inhibition of skin inflammation in mice by diclofenac in vesicular carriers: liposomes, ethosomes and PEVs.

    Science.gov (United States)

    Caddeo, Carla; Sales, Octavio Diez; Valenti, Donatella; Saurí, Amparo Ruiz; Fadda, Anna Maria; Manconi, Maria

    2013-02-25

    Diclofenac-loaded phospholipid vesicles, namely conventional liposomes, ethosomes and PEVs (penetration enhancer-containing vesicles) were developed and their efficacy in TPA (phorbol ester) induced skin inflammation was examined. Vesicles were made from a cheap and unpurified mixture of phospholipids and diclofenac sodium; Transcutol P and propylene glycol were added to obtain PEVs, and ethanol to produce ethosomes. The structure and lamellar organization of the vesicle bilayer were investigated by transmission electron microscopy and small and wide angle X-ray scattering, as well as the main physico-chemical features. The formulations, along with a diclofenac solution and commercial Voltaren Emulgel, were tested in a comparative trial for anti-inflammatory efficacy on TPA-treated mice dorsal skin. Vesicles were around 100 nm, negatively charged, able to encapsulate diclofenac in good yields, and disclosed different lamellarity, as a function of the formulation composition. Vesicular formulations promoted drug accumulation and reduced the permeation. Administration of vesicular diclofenac on TPA-inflamed skin resulted in marked attenuation of oedema and leucocyte infiltration, especially using PEVs. Histology confirmed the effectiveness of vesicles, since they provided an amelioration of the tissual damage induced by TPA. The proposed approach based on vesicular nanocarriers may hold promising therapeutic value for treating a variety of inflammatory skin disorders.

  14. Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Bang, G

    1992-01-01

    Host tissue response and heterotopic osteoinduction by composites of demineralized bone matrix and three different substances used as bioresorbable carriers implanted in the abdominal muscles were evaluated by strontium 85 uptake and histology 4 weeks postoperatively in 60 male Wistar rats. Both...

  15. Sterol carrier protein 2 regulates proximal tubule size in the Xenopus pronephric kidney by modulating lipid rafts.

    Science.gov (United States)

    Cerqueira, Débora M; Tran, Uyen; Romaker, Daniel; Abreu, José G; Wessely, Oliver

    2014-10-01

    The kidney is a homeostatic organ required for waste excretion and reabsorption of water, salts and other macromolecules. To this end, a complex series of developmental steps ensures the formation of a correctly patterned and properly proportioned organ. While previous studies have mainly focused on the individual signaling pathways, the formation of higher order receptor complexes in lipid rafts is an equally important aspect. These membrane platforms are characterized by differences in local lipid and protein compositions. Indeed, the cells in the Xenopus pronephric kidney were positive for the lipid raft markers ganglioside GM1 and Caveolin-1. To specifically interfere with lipid raft function in vivo, we focused on the Sterol Carrier Protein 2 (scp2), a multifunctional protein that is an important player in remodeling lipid raft composition. In Xenopus, scp2 mRNA was strongly expressed in differentiated epithelial structures of the pronephric kidney. Knockdown of scp2 did not interfere with the patterning of the kidney along its proximo-distal axis, but dramatically decreased the size of the kidney, in particular the proximal tubules. This phenotype was accompanied by a reduction of lipid rafts, but was independent of the peroxisomal or transcriptional activities of scp2. Finally, disrupting lipid micro-domains by inhibiting cholesterol synthesis using Mevinolin phenocopied the defects seen in scp2 morphants. Together these data underscore the importance for localized signaling platforms in the proper formation of the Xenopus kidney.

  16. The interaction between plasma rotation, stochastic fields and tearing mode excitation by external perturbation fields

    Science.gov (United States)

    DeBock, M. F. M.; Classen, I. G. J.; Busch, C.; Jaspers, R. J. E.; Koslowski, H. R.; Unterberg, B.; TEXTOR Team

    2008-01-01

    For fusion reactors, based on the principle of magnetic confinement, it is important to avoid so-called magnetic islands or tearing modes. They reduce confinement and can be the cause of major disruptions. One class of magnetic islands is that of the perturbation field driven modes. This perturbation field can, for example, be the intrinsic error field. Theoretical work predicts a strong relationship between plasma rotation and the excitation of perturbation field modes. Experimentally, the theory on mode excitation and plasma rotation has been confirmed on several tokamaks. In those experiments, however, the control over the plasma rotation velocity and direction, and over the externally applied perturbation field was limited. In this paper experiments are presented that were carried out at the TEXTOR tokamak. Two tangential neutral beam injectors and a set of helical perturbation coils, called the dynamic ergodic divertor (DED), provide control over both the plasma rotation and the external perturbation field in TEXTOR. This made it possible to set up a series of experiments to test the theory on mode excitation and plasma rotation in detail. The perturbation field induced by the DED not only excites magnetic islands, it also sets up a layer near the plasma boundary where the magnetic field is stochastic. It will be shown that this stochastic field alters both the rotational response of the plasma on the perturbation field and the threshold for mode excitation. It therefore has to be included in an extended theory on mode excitation.

  17. Ultrahigh sensitive MoTe2 phototransistors driven by carrier tunneling

    Science.gov (United States)

    Yin, Lei; Zhan, Xueying; Xu, Kai; Wang, Feng; Wang, Zhenxing; Huang, Yun; Wang, Qisheng; Jiang, Chao; He, Jun

    2016-01-01

    Transition metal dichalcogenides (TMDs) demonstrate great potential in electronic and optoelectronic applications. However, the device performance remains limited because of the poor metal contact. Herein, we fabricate a high-performance ultrathin MoTe2 phototransistor. By introducing an electron tunneling mechanism, electron injection from electrode to channel is strikingly enhanced. The electron mobility approaches 25.2 cm2 V-1 s-1, better than that of other back-gated MoTe2 FETs. Through electrical measurements at various temperatures, the electron tunneling mechanism is further confirmed. The MoTe2 phototransistor exhibits very high responsivity up to 2560 A/W which is higher than that of most other TMDs. This work may provide guidance to reduce the contact resistance at metal-semiconductor junction and pave a pathway to develop high-performance optoelectronic devices in the future.

  18. Ultrahigh sensitive MoTe{sub 2} phototransistors driven by carrier tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Lei; Zhan, Xueying; Xu, Kai; Wang, Feng; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn; Huang, Yun; Wang, Qisheng; Jiang, Chao; He, Jun, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn [CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China)

    2016-01-25

    Transition metal dichalcogenides (TMDs) demonstrate great potential in electronic and optoelectronic applications. However, the device performance remains limited because of the poor metal contact. Herein, we fabricate a high-performance ultrathin MoTe{sub 2} phototransistor. By introducing an electron tunneling mechanism, electron injection from electrode to channel is strikingly enhanced. The electron mobility approaches 25.2 cm{sup 2} V{sup −1} s{sup −1}, better than that of other back-gated MoTe{sub 2} FETs. Through electrical measurements at various temperatures, the electron tunneling mechanism is further confirmed. The MoTe{sub 2} phototransistor exhibits very high responsivity up to 2560 A/W which is higher than that of most other TMDs. This work may provide guidance to reduce the contact resistance at metal-semiconductor junction and pave a pathway to develop high-performance optoelectronic devices in the future.

  19. Increasing minority carrier lifetime in as-grown multicrystalline silicon by low temperature internal gettering

    Science.gov (United States)

    Al-Amin, M.; Murphy, J. D.

    2016-06-01

    We report a systematic study into the effects of long low temperature (≤500 °C) annealing on the lifetime and interstitial iron distributions in as-grown multicrystalline silicon (mc-Si) from different ingot height positions. Samples are characterised in terms of dislocation density, and lifetime and interstitial iron concentration measurements are made at every stage using a temporary room temperature iodine-ethanol surface passivation scheme. Our measurement procedure allows these properties to be monitored during processing in a pseudo in situ way. Sufficient annealing at 300 °C and 400 °C increases lifetime in all cases studied, and annealing at 500 °C was only found to improve relatively poor wafers from the top and bottom of the block. We demonstrate that lifetime in poor as-grown wafers can be improved substantially by a low cost process in the absence of any bulk passivation which might result from a dielectric surface film. Substantial improvements are found in bottom wafers, for which annealing at 400 °C for 35 h increases lifetime from 5.5 μs to 38.7 μs. The lifetime of top wafers is improved from 12.1 μs to 23.8 μs under the same conditions. A correlation between interstitial iron concentration reduction and lifetime improvement is found in these cases. Surprisingly, although the interstitial iron concentration exceeds the expected solubility values, low temperature annealing seems to result in an initial increase in interstitial iron concentration, and any subsequent decay is a complex process driven not only by diffusion of interstitial iron.

  20. Magnetic microparticles post-synthetically coated by hyaluronic acid as an enhanced carrier for microfluidic bioanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Holubova, Lucie [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Knotek, Petr [Joint Laboratory of Solid State Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Palarcik, Jiri [Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Cadkova, Michaela [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Belina, Petr [Department of Inorganic Technology, Faculty of Chemical Technology, University of Pardubice, Doubravice 41, 53210 Pardubice (Czech Republic); Vlcek, Milan [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho sq. 2, 16206 Prague (Czech Republic); Korecka, Lucie [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Bilkova, Zuzana, E-mail: Zuzana.Bilkova@upce.cz [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic)

    2014-11-01

    Iron oxide based particles functionalized by bioactive molecules have been utilized extensively in biotechnology and biomedicine. Despite their already proven advantages, instability under changing reaction conditions, non-specific sorption of biomolecules on the particles' surfaces, and iron oxide leakage from the naked particles can greatly limit their application. As confirmed many times, surface treatment with an appropriate stabilizer helps to minimize these disadvantages. In this work, we describe enhanced post-synthetic surface modification of superparamagnetic microparticles varying in materials and size using hyaluronic acid (HA) in various chain lengths. Scanning electron microscopy, atomic force microscopy, phase analysis light scattering and laser diffraction are the methods used for characterization of HA-coated particles. The zeta potential and thickness of HA-layer of HA-coated Dynabeads M270 Amine were − 50 mV and 85 nm, respectively, and of HA-coated p(GMA-MOEAA)-NH{sub 2} were − 38 mV and 140 nm, respectively. The electrochemical analysis confirmed the zero leakage of magnetic material and no reactivity of particles with hydrogen peroxide. The rate of non-specific sorption of bovine serum albumin was reduced up to 50% of the naked ones. The coating efficiency and suitability of biopolymer-based microparticles for magnetically active microfluidic devices were confirmed. - Highlights: • Post-synthetic surface modification of magnetic microparticles by hyaluronic acid • Hyaluronic acid — polymer of unique physicochemical and biological characteristics • Panel of particle characterization methods was introduced. • HA-coated microparticles gain characteristics suited for microfluidic bioanalysis.

  1. Control to Three-phase Inverter by Sliding Mode

    Directory of Open Access Journals (Sweden)

    Mouhamadou Thiam

    2014-03-01

    Full Text Available In this study, it is treated the modeling and the ordering of a three-phase inverter. The studied system is a load supplied with a three-phase inverter by means of a transformer. The ordering of the inverter is with PWM (pulse-width modulation/pulse-width Modulation and its regulation is made by the sliding method. This method is presented in this document with its various laws. The simulation of the unit is made and the results presented.

  2. Delivery of a foreign epitope by sharing amino acid residues with the carrier matrix.

    Science.gov (United States)

    Cheong, Wan-Shoo; Drummer, Heidi Edelgard; Netter, Hans-Jürgen

    2009-06-01

    A broad range of structural viral proteins has the ability to assemble into virus-like particles (VLPs). Under the condition that modified subunits are still competent to assemble into VLPs, they are epitope delivery platforms suitable for vaccination purposes. The insertion of foreign sequences can be detrimental for the formation of chimeric VLPs as a result of misfolded subunit proteins. Hence, a strategy was adopted to screen for locations allowing the use of shared residues between the wildtype subunit sequence and the foreign insert. The insertion of a cysteine-containing sequence of hepatitis C virus (HCV) envelope protein 2 (E2) without adding an additional cysteine residue retained the ability of recombinant small hepatitis B surface antigen (HBsAg-S) to form secretion competent VLPs. A cysteine residue shared by the insert and the template protein avoided the formation of non-native disulfide bonds, and allowed the formation of VLPs. The chimeric HBsAg-S VLPs were similar to wildtype VLPs in density exposing the inserted foreign epitope and being immunogenic. Overall, the use of shared sequences between the insert and the subunit will facilitate the design of chimeric VLPs carrying multiple epitopes.

  3. Broad-band robustly single-mode hollow-core PCF by resonant filtering of higher order modes

    CERN Document Server

    Günendi, Mehmet C; Frosz, Michael H; Russell, Philip St J

    2015-01-01

    We propose and theoretically analyse a novel hollow-core photonic crystal fibre (PCF) that is engineered so as to strongly suppress higher order modes, i.e., to provide robust LP$_{01}$ single-mode guidance in all the wavelength ranges where the fibre guides with low loss. Encircling the core is a single ring of non-touching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes, causing them to leak at a very high rate into the supporting solid glass sheath. Using a model based on coupled capillary waveguides, as well as full vectorial finite element modelling, we show that this modal filtering effect depends on only one dimensionless geometrical parameter, akin to the well-known $d/{\\Lambda}$ parameter for endlessly single-mode solid-core PCF. The design is scalable up to large core sizes and is predicted to deliver LP$_{01}$ mode losses of some $10$s of dB/km in multiple transmission windows, the broadest of which spans more than an octave. At the same ...

  4. Responsible implementation of expanded carrier screening

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-01-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines. PMID:26980105

  5. Responsible implementation of expanded carrier screening.

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-06-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.

  6. [Optimization and comparison of nitrogen and phosphorus removal by different aeration modes in oxidation ditch].

    Science.gov (United States)

    Guo, Chang-Zi; Peng, Dang-Cong; Cheng, Xue-Mei; Wang, Dan

    2012-03-01

    The oxidation ditch operation mode was simulated by sequencing batch reactor (SBR) system with alternate stirring and aeration. The nitrogen and phosphorus removal efficiencies were investigated in two different aeration modes: point aeration and step aeration. Experimental results show that oxygen is dissolved more efficiently in point aeration mode with a longer aerobic region in the same air supply capacity, but dissolved oxygen (DO) utilization efficiency for nitrogen and phosphorus removal is high in step aeration mode. Nitrification abilities of the two modes are equal with ammonia-nitrogen (NH4(+) -N) removal efficiency of 96.68% and 97.03%, respectively. Nitrifier activities are 4.65 and 4.66 mg x (g x h)(-1) respectively. When the ratio of anoxic zones and the aerobic zones were 1, the total nitrogen (TN) removal efficiency of point aeration mode in 2, 4 or 7 partitions was respectively 60.14%, 47.93% and 33.7%. The total phosphorus (TP) removal efficiency was respectively 28.96%, 23.75% and 24.31%. The less the partitions, the higher the nitrogen and phosphorus removal efficiencies, but it is in more favor of TN removal. As for step aeration mode with only one partitioning zone, the TN and TP removal efficiencies are respectively 64.21% and 49.09%, which is better than in point aeration mode, but more conducive to the improvement of TP removal efficiency. Under the condition of sufficient nitrification in step aeration mode, the nitrogen and phosphorus removal is better with the increase of anoxic zone. The removal efficiencies of TN and TP respectively rose to 73.94% and 54.18% when the ratio of anoxic zones and the aerobic zones was increased from 1 : 1 to 1. 8 : 1. As the proportion of anoxic zones was enlarged further, nitrification and operation stability were weakened so as to affect the nitrogen and phosphorus removal efficiencies.

  7. Resonant Acceleration of Magnetospheric Electrons Driven by the R-X Mode

    Institute of Scientific and Technical Information of China (English)

    XIAO Fu-Liang; ZHENG Hui-Nan; WANG Shui

    2005-01-01

    @@ An extended relativistic model is developed to evaluate the superluminous R-X-mode resonance especially the second-order and third-order resonances with electrons in the Earth's magnetosphere. The potential for stochastic electron acceleration driven by the R-X mode is determined by the dispersive properties of the R-X mode and specifically the resonant harmonic N. In contrast to the limited acceleration at the first harmonic (N = 1)resonance, for the higher harmonic (N > 1) resonances, the R-X mode is capable of accelerating electrons from ~10keV to ~ MeV energies, over a wide range of wave normal angles, in spatial regions extending from the auroral cavity to the latitude (>30°) outer radiation belt. This indicates that higher-order resonance is essentially important for the electron acceleration for the oblique wave propagation.

  8. Large modulation of carrier transport by grain-boundary molecular packing and microstructure in organic thin films

    KAUST Repository

    Rivnay, Jonathan

    2009-11-08

    Solution-processable organic semiconductors are central to developing viable printed electronics, and performance comparable to that of amorphous silicon has been reported for films grown from soluble semiconductors. However, the seemingly desirable formation of large crystalline domains introduces grain boundaries, resulting in substantial device-to-device performance variations. Indeed, for films where the grain-boundary structure is random, a few unfavourable grain boundaries may dominate device performance. Here we isolate the effects of molecular-level structure at grain boundaries by engineering the microstructure of the high-performance n-type perylenediimide semiconductor PDI8-CN 2 and analyse their consequences for charge transport. A combination of advanced X-ray scattering, first-principles computation and transistor characterization applied to PDI8-CN 2 films reveals that grain-boundary orientation modulates carrier mobility by approximately two orders of magnitude. For PDI8-CN 2 we show that the molecular packing motif (that is, herringbone versus slip-stacked) plays a decisive part in grain-boundary-induced transport anisotropy. The results of this study provide important guidelines for designing device-optimized molecular semiconductors. © 2009 Macmillan Publishers Limited. All rights reserved.

  9. Effects of Ge replacement in GeTe by Ag or Sb on the Seebeck coefficient and carrier concentration modified by local electron imbalance

    Science.gov (United States)

    Levin, E. M.; Howard, A.; Straszheim, W. E.

    2015-03-01

    XRD, SEM, EDS, 125Te NMR, Seebeck coefficient, and electrical resistivity of AgxGe50-xTe50 and SbxGe50-xTe50 alloys have been studied. Replacement of Ge in GeTe by Sb significantly increases the Seebeck coefficient, while replacement by Ag decreases it. These effects can be attributed to a change in carrier concentration observed via 125Te NMR spin-lattice relaxation measurements and NMR signal position, which mostly depends on the Knight shift. Variation in carrier concentration in AgxGe50-xTe50 and SbxGe50-xTe50 can be attributed to different electron configurations of valence electrons of Ag (4d105s1) and Sb (5s25p3) compared to that of Ge (4s24p2) resulting in local electron imbalances and changing the concentration of charge carrier (holes) generated by Ge vacancies. In contrast, our 125Te NMR and Seebeck coefficient data for Ag2Sb2Ge46Te50 are similar to those observed for GeTe. This shows that effects from Ag and Sb compensate each other and indicates the existence of [Ag +Sb] pairs. The effects of Ge replacement in GeTe by Ag, Sb, or [Ag +Sb] on rhombohedral lattice distortion also have been analyzed. Interplay between the Seebeck coefficient and electrical resistivity in these alloys results in variation of power factor; the value of 45 mW/cm K2, the highest among known tellurides, was found for Sb2Ge48Te50.

  10. Maximum modulation of plasmon-guided modes by graphene gating

    DEFF Research Database (Denmark)

    Radko, Ilya; Bozhevolnyi, Sergey I.; Grigorenko, Alexander N.

    2016-01-01

    The potential of graphene in plasmonic electro-optical waveguide modulators has been investigated in detail by finite-element method modelling of various widely used plasmonic waveguiding configurations. We estimated the maximum possible modulation depth values one can achieve with plasmonic...... devices operating at telecom wavelengths and exploiting the optical Pauli blocking effect in graphene. Conclusions and guidelines for optimization of modulation/intrinsic loss trade-off have been provided and generalized for any graphene-based plasmonic waveguide modulators, which should help...

  11. Dynamical modelling of neoclassical tearing mode suppression by ECCD

    Directory of Open Access Journals (Sweden)

    Westerhof Egbert

    2012-09-01

    Full Text Available The rotation of a magnetic island through the EC power deposition region in combination with a finite collisional time scale on which the EC power is converted into current are shown to affect the NTM stabilization by ECCD. In particular, the stabilizing term from localized ECCD in the generalized Rutherford equation oscillates at the island rotation frequency. As a consequence, also the island width oscillates at the rotation frequency. When the rotation frequency is reduced, these oscillations increase in amplitude and result in a net increase of the time averaged stabilizing effect of ECCD.

  12. Tunable defect mode realized by graphene-based photonic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiahui; Chen, Wan, E-mail: dhtyyobdc@126.com; Lv, Bo

    2016-04-29

    In this literature, we propose an active terahertz 1D photonic crystal, which consists of silicon layers and air layers. A graphene sheet is embedded at the interface between dielectric and air. Tunable photonic band gap is realized by changing the Fermi level of graphene. Transmission Matrix Method is utilized to explain the influence of the graphene layer. We also demonstrate that a dielectric slab attached with a thin sheet made of single-negative metamaterial acts like a pure dielectric slab with a thinner thickness. A tunable blue shift of the band gap can be realized by simply applying different chemical potentials on the graphene sheet. This feature can be utilized for the design of tunable high-gain antenna array and force generator in terahertz band. - Highlights: • A novel PhC embedded with grapheme sheets is presented, tunable defect is realized. • The mechanism of the tunable defect is explained using the change of equivalent thickness. • The electromagnetic force of a slab is calculated, which indicates the structure can serve as a tunable force generator.

  13. Content Distribution for Telecom Carriers

    Directory of Open Access Journals (Sweden)

    Ben Falchuk

    2006-08-01

    Full Text Available Distribution of digital content is a key revenue opportunity for telecommunications carriers. As media content moves from analog and physical media-based distribution to digital on-line distribution, a great opportunity exists for carriers to claim their role in the media value chain and grow revenue by enhancing their broadband “all you can eat” high speed Internet access offer to incorporate delivery of a variety of paid content. By offering a distributed peer to peer content delivery capability with authentication, personalization and payment functions, carriers can gain a larger portion of the revenue paid for content both within and beyond their traditional service domains. This paper describes an approach to digital content distribution that leverages existing Intelligent Network infrastructure that many carriers already possess, as well as Web Services.

  14. Nongrounded Common-Mode Equivalent Circuit for Brushless DC Motor Driven by PWM Inverter

    Science.gov (United States)

    Maetani, Tatsuo; Isomura, Yoshinori; Watanabe, Akihiko; Iimori, Kenichi; Morimoto, Shigeo

    This paper describes nongrounded common-mode equivalent circuit for a motor driven by a voltage-source PWM inverter. When the capacitance of the rotor was small, the phenomenon that polarity of the common mode voltage and shaft voltage reversed was observed. In order to model this phenomenon, the bridge type equivalent circuit is proposed. It is verified with the calculation and experiment that shaft voltage values and polarity are accurately calculated with the proposed equivalent circuit.

  15. Probabilistic teleportation scheme of two-mode entangled photon states by using linear optic element

    Institute of Scientific and Technical Information of China (English)

    XIANG Shao-hua

    2003-01-01

    A scheme for teleporting two-mode entangled photon states with the successful probability 33.3% is proposed. In the scheme, the teleporte d qubit is two-mode photon entangled states, and two pairs of EPR pair are used as quantum channel between a sender and a receiver. This procedure is achieved by using two 50/50 symmetric beam splitters and four photon number detectors wit h the help of classical information.

  16. Surface Integrity of Inconel 718 by Wire-EDM at Different Energy Modes

    Science.gov (United States)

    Li, L.; Wei, X. T.; Guo, Y. B.; Li, W.; Liu, J. F.

    2014-08-01

    Inconel alloys including IN 718 alloy are widely used in turbomachinery industry due to their superior mechanical properties. Inconel alloys are very difficult to machine using cutting and grinding. Wire electrical discharge machining (W-EDM) is an alternative process to manufacture complex Inconel parts. However, little research has been done on surface integrity by W-EDMed IN 718. This study focuses on surface integrity of IN 718 by W-EDM at different modes of discharge energy. The results show that the EDMed surface topography shows dominant coral reef microstructures at high energy mode, while random microvoids are dominant at low energy modes. The average roughness can be significantly reduced at low energy mode. A thick white layer is predominantly discontinuous and non-uniform at relative high energy modes. Microvoids are confined within the thick white layers and no microcracks were found in the subsurface. A thin white layer by trim cut at low energy mode becomes continuous, uniform, and is free of voids. Compared to the bulk, white layers have dramatic reduction in microhardness. In addition, surface alloying from wire electrode and water dielectric is obvious in main cut, but it can be minimized in trim cuts.

  17. Transport of platinum bonded nucleotides into proteoliposomes, mediated by Drosophila melanogaster thiamine pyrophosphate carrier protein (DmTpc1).

    Science.gov (United States)

    Carrisi, Chiara; Antonucci, Daniela; Lunetti, Paola; Migoni, Danilo; Girelli, Chiara R; Dolce, Vincenza; Fanizzi, Francesco P; Benedetti, Michele; Capobianco, Loredana

    2014-01-01

    The results of the present study suggest that DmTpc1 is actively implicated in the specific uptake of free cytoplasmic Pt bonded nucleotides, and therefore could be linked to the mechanism of action of some platinum-based antitumor drugs. Although DmTpc1 has a low affinity for model [Pt(dien)(N7-5'-dGTP)] and cis-[Pt(NH3)2(py)(N7-5'-dGTP)] compared to dATP it's well known that DNA platination level of few metal atoms per double-stranded molecule may account for the pharmacological activity of platinum based antitumor drugs. This is the first investigation where it has been demonstrated that a mitochondrial carrier is directly involved in the transport of metalated purines related with the cisplatin mechanism of action. Moreover it is shown as a lower hindrance of nucleotide bonded platinum complexes could strongly enhance mitochondrial uptake. Furthermore, a new application of ICP-AES addressed to measure the transport of metalated nucleobases, by using a recombinant protein reconstituted into liposomes, has been here, for the first time, developed and compared with a standard technique such as the liquid scintillation counting.

  18. ABA TRIBLOCK COPOLYMERS WITH PENDANT HYDROXYL GROUPS PREPARED BY CONTROLLED CATIONIC POLYMERIZATION AND THEIR USE AS DELIVERY CARRIER FOR PACLITAXEL

    Institute of Scientific and Technical Information of China (English)

    Ping Ren; Yi-bo Wu; Wen-li Guo; Shu-xin Li; Ying Chen

    2013-01-01

    To improve the hydrophilicity of poly(styrene-b-isobutylene-b-styrene) (SIBS),this study focuses on the synthesis of novel functional ABA triblock copolymer thermoplastic elastomers (TPEs) with polyisobutylene (PIB) as rubbery segments.The precursor poly{(styrene-co-4-[2-(tert-butyldimethylsiloxy) ethyl]styrene)-b-isobutylene-b-(styrene-co-4-[2-(tert-butyldimethylsiloxy)ethyl]styrene)}(P(St-co-TBDMES)-PIB-P(St-co-TBDMES)) triblock copolymer was first synthesized by living sequential cationic copolymerization of isobutylene (IB) with styrene (St) and 4-[2-(tert-butyldimethylsiloxy)ethyl]styrene (TBDMES) using 1,4-di(2-chloro-2-propyl)benzene (DiCumC1)/titanium tetrachloride (TiCl4)/2,6-di-tert-butylpyridine (DtBP) as the initiating system.Then,P(St-co-TBDMES)-PIB-P(St-co-TBDMES) was hydrolyzed in the presence of tetra-butylammonium fluoride to yield poly{[styrene-co-4-(2-hydroxyethyl)styrene]-b-isobutylene-b-[styrene-co-4-(2-hydroxyethyl)styrene]} (P(St-co-HOES)-PIB-P(St-co-HOES)) with pendant hydroxyl groups.P(St-co-HOES)-PIB-P(St-co-HOES) used as the paclitaxel carrier was also investigated in this study.Comparing with SIBS,P(St-co-HOES)-PIB-P(St-co-HOES) has exhibited better compatibility with paclitaxel and higher release rate.

  19. Synergistic extraction and separation of Co(II)/Ni(II) by solvent extraction technique using TIOA/TOPO as carriers

    Science.gov (United States)

    Okatan, Ahmet; Eyüpoǧlu, Volkan; Kumbasar, Recep Ali; Turgut, Halil Ibrahim

    2016-04-01

    Cobalt and its compounds have wide range applications in some industrial and technological fields. These metals show excellent resistance to oxidation and corrosion under extreme conditions. However, these metals found together within metal ores in nature. This situation makes their separation difficult from each other. They have very similar physical and chemical properties making them very hard to be purified with using traditional separation pathways. Moreover, increasing supply-demand gap between them and decreasing valuable ores because of limited deposit in earth crust have been limited the sources of them. Under the light of this knowledge, one of the practical solutions should be produced to recycle cobalt and nickel from solid and liquid waste containing trace amounts of them. In this study, we investigated the selective and the synergistic cobalt extraction from acidic aqueous solutions by solvent extraction using tri-iso-octylamine (TIOA) and Tri-n-octyl phosphine oxide (TOPO) as carriers. The effective parameters on the extraction and the stripping of the cobalt were investigated, and optimum synergistic extraction and stripping conditions were identified. The cobalt extraction from aqueous Co/Ni solutions in various molar concentrations was examined in the optimum conditions to determine the synergism between TIOA and TOPO.

  20. Production of no-carrier-added radiobromine. new nickel selenide target and optimized separation by dry distillation

    Energy Technology Data Exchange (ETDEWEB)

    Breunig, Katharina; Spahn, Ingo; Spellerberg, Stefan; Coenen, Heinz H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Neurowissenschaften und Medizin (INM), Nuklearchemie (INM-5)

    2015-07-01

    Nickel(II) selenide (NiSe) was investigated as a new high-current target material for cyclotron production of radiobromine, as it contains a higher amount of selenium and has a lower melting point than the widely used Cu{sub 2}Se. Using a slanted target system, NiSe was successfully tested up to beam currents of 16 μA so far. With regard to the isolation of no-carrier-added (n.c.a.) radiobromide from the target material, an improved dry distillation device with high yields of 76%-86% was developed. The implementation of a special custom-made quartz funnel decreased the dead volume of the apparatus and a quartz capillary for trapping the radiobromine allowed to concentrate the radioactivity in a small volume of less than 100 μL of 0.1 M NaOH, ready for immediate subsequent radiosyntheses. Thus, the new apparatus improves the handling of the isolation procedure and the radioactive product. The radiochemical purity of the resulting solution of n.c.a. [*Br]bromide was verified by radio-IC where no other species were detected.

  1. Charge carrier transport properties of methyl-ammonium-lead-trihalide perovskites investigated by the time-of-flight method

    Science.gov (United States)

    Lafalce, Evan; Zhang, Chuang; Vardeny, Z. Valy; University of Utah Team

    We studied the charge transport properties of methyl-ammonium-lead-trihalide perovskites using the photocurrent transient time-of-flight method. Various morphologies that include single-crystals and thin films with different crystalline grain sizes and surface roughness were investigated. The photocurrent transients were recorded as a function of excitation wavelength, intensity, and applied electric field as well as the sample temperature. We found that surface recombination leads to a photocurrent response that is sharply peaked at the band edge. While the carrier mobility depends on the sample preparation and sample temperature, typical values are on the order of 1cm2/Vs, consistent with previous reports using similar methods. This value is high compared to other solution-processed semiconductors such as pi-conjugated polymers and quantum dots; however it is relatively low compared to inorganic semiconductors. Therefore determining the mobility limiting factors in hybrid perovskite devices is important for progress in their optoelectronic device performance. This work was funded by ONR Grant N00014-15-1-2524 at the Un. of Utah.

  2. Improvement of isobutanol production in Saccharomyces cerevisiae by increasing mitochondrial import of pyruvate through mitochondrial pyruvate carrier.

    Science.gov (United States)

    Park, Seong-Hee; Kim, Sujin; Hahn, Ji-Sook

    2016-09-01

    Subcellular compartmentalization of the biosynthetic enzymes is one of the limiting factors for isobutanol production in Saccharomyces cerevisiae. Previously, it has been shown that mitochondrial compartmentalization of the biosynthetic pathway through re-locating cytosolic Ehrlich pathway enzymes into the mitochondria can increase isobutanol production. In this study, we improved mitochondrial isobutanol production by increasing mitochondrial pool of pyruvate, a key substrate for isobutanol production. Mitochondrial isobutanol biosynthetic pathway was introduced into bat1Δald6Δlpd1Δ strain, where genes involved in competing pathways were deleted, and MPC1, MPC2, and MPC3 genes encoding the subunits of mitochondrial pyruvate carrier (MPC) hetero-oligomeric complex were overexpressed with different combinations. Overexpression of Mpc1 and Mpc3 forming high-affinity MPCOX was more effective in improving isobutanol production than overexpression of Mpc1 and Mpc2 forming low-affinity MPCFERM. The final engineered strain overexpressing MPCOX produced 330.9 mg/L isobutanol from 20 g/L glucose, exhibiting about 22-fold increase in production compared to wild type.

  3. A novel method for measuring carrier lifetime and capture cross-section by using the negative resistance I-V characteristics of a barrier-type thyristor

    Energy Technology Data Exchange (ETDEWEB)

    Li Hairong; Li Siyuan, E-mail: hrli@lzu.edu.c [Institute of Microelectronics, Lanzhou University, Lanzhou 730000 (China)

    2010-08-15

    A brand new and feasible method for measuring the carrier lifetime and capture cross-section of a barrier by using the negative resistance segment of the I-V characteristics of a barrier-type thyristor (BTH) is put forward. The measuring principle and calculation method are given. The BTH samples are experimentally measured and the results are analyzed in detail. (semiconductor devices)

  4. 41 CFR 302-10.301 - May I receive an advance of funds when payment is made directly to the carrier by my agency?

    Science.gov (United States)

    2010-07-01

    ... of funds when payment is made directly to the carrier by my agency? 302-10.301 Section 302-10.301... TRANSPORTATION AND STORAGE OF PROPERTY 10-ALLOWANCES FOR TRANSPORTATION OF MOBILE HOMES AND BOATS USED AS A PRIMARY RESIDENCE Advance of Funds § 302-10.301 May I receive an advance of funds when payment is...

  5. Medium optimization for nuclease P1 production by Penicillium citrinum in solid-state fermentation using polyurethane foam as inert carrier

    NARCIS (Netherlands)

    Zhu, Y.; Knol, W.; Smits, J.P.; Bol, J.

    1996-01-01

    A solid-state fermentation system, using polyurethane foam as an inert carrier, was used for the production of nuclease P1 by Penicillium citrinum. Optimization of nuclease P1 production was carried out using a synthetic liquid medium. After a two-step medium optimization using a fractional factoria

  6. Damage Detection by the Mode-Selectable Magnetostrictive Transducer for Cylindrical Ferromagnetic Waveguides

    Science.gov (United States)

    Kim, Youngkyu; Kim, Ikkyu; Kim, Yoon Young

    2004-02-01

    In recent years, ultrasonic inspection techniques adopting magnetostrictive effects have received much attention, because they are non-destructive and require no direct physical contact with target systems. By selecting the desired wave mode and thus rejecting the unwanted modes amongst propagating waves in cylindrical ferromagnetic waveguides, we can effectively detect various types of flaws. However, a bending wave mode selecting technique, in particular, has not been fully developed yet. The purpose of this work is to present a technique to select either bending or longitudinal waves alone from compound waves propagating in ferromagnetic cylindrical waveguide. To achieve this goal, a new bias magnet configuration suitable for bending mode selection is suggested. The experimental results verify the effectiveness of the proposed method.

  7. Failure Modes of Lead Free Solder Bumps Formed by Induction Spontaneous Heating Reflow

    Institute of Scientific and Technical Information of China (English)

    Mingyu LI; Hongbo XU; Jongmyung KIM; Hongbae KIM

    2007-01-01

    The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves (shear force vs displacement). From the results of interfacial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle Ni3Sn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.

  8. Gain equalization of FM-EDFA by optimizing ring doping and mode content of the pump with a genetic algorithm

    Science.gov (United States)

    Qiu, Changren; Yang, Tianxin; Jia, Dong fang; Wang, Zhaoying; Ge, Chunfeng

    2015-03-01

    We investigate gain equalization of a four-mode-group and six-mode-group erbium-doped fiber amplifiers with a genetic algorithm for mode division multiplexing transmission systems by optimizing rare earth dopant profile and pump modes powers, respectively. The optimizing gains are calculated to be > 28 dB between 1520 nm - 1565 nm with a maximum differential modal gain of ~ 2 dB among the mode groups only by optimizing the rare earth ring doping profile in the few-mode erbium-doped fiber.

  9. Discovery of Highly Selective and Nanomolar Carbamate-Based Butyrylcholinesterase Inhibitors by Rational Investigation into Their Inhibition Mode.

    Science.gov (United States)

    Sawatzky, Edgar; Wehle, Sarah; Kling, Beata; Wendrich, Jan; Bringmann, Gerhard; Sotriffer, Christoph A; Heilmann, Jörg; Decker, Michael

    2016-03-10

    Butyrylcholinesterase (BChE) is a promising target for the treatment of later stage cognitive decline in Alzheimer's disease. A set of pseudo-irreversible BChE inhibitors with high selectivity over hAChE was synthesized based on carbamates attached to tetrahydroquinazoline scaffolds with the 2-thiophenyl compound 2p as the most potent inhibitor of eqBChE (KC = 14.3 nM) and also of hBChE (KC = 19.7 nM). The inhibitors transfer the carbamate moiety onto the active site under release of the phenolic tetrahydroquinazoline scaffolds that themselves act as neuroprotectants. By combination of kinetic data with molecular docking studies, a plausible binding model was probed describing how the tetrahydroquinazoline scaffold guides the carbamate into a close position to the active site. The model explains the influence of the carrier scaffold onto the affinity of an inhibitor just before carbamate transfer. This strategy can be used to utilize the binding mode of other carbamate-based inhibitors.

  10. Effects of field-aligned flows on standing kink and sausage modes supported by coronal loops

    CERN Document Server

    Chen, S -X; Xia, L -D; Chen, Y -J; Yu, H

    2013-01-01

    Fundamental standing modes and their overtones play an important role in coronal seismology. We examine how a significant field-aligned flow affects standing modes supported by coronal loops, modeled here as cold magnetic slabs. Of particular interest are the period ratios of the fundamental to its $(n-1)$-th overtone ($P_1/nP_n$) for both kink and sausage modes, and the threshold half-width-to-length ratio for sausage modes. For standing kink modes, the flow significantly reduces $P_1/nP_n$ in general, the effect being particularly strong for larger $n$ and when the density contrast $\\rho_0/\\rho_e$ between loops and their surroundings is weak. That said, even when $\\rho_0/\\rho_e$ approaches infinity, this effect is still substantial, reducing the minimal $P_1/nP_n$ by up to 13.7% (24.5%) for $n=2$ ($n=4$) relative to the static case, when the Alfv\\'en Mach number $M_A$ reaches 0.8 where $M_A$ measures the loop flow speed in units of the internal Alfv\\'en speed. For standing sausage modes, though not negligib...

  11. Incompressible Modes Excited by Supersonic Shear in Boundary Layers: Acoustic CFS Instability

    CERN Document Server

    Belyaev, Mikhail

    2016-01-01

    We present an instability for exciting incompressible modes (e.g. gravity or Rossby modes) at the surface of a star accreting through a boundary layer. The instability excites a stellar mode by sourcing an acoustic wave in the disk at the boundary layer, which carries a flux of energy and angular momentum with the opposite sign as the energy and angular momentum density of the stellar mode. We call this instability the acoustic CFS instability, because of the direct analogy to the Chandrasekhar-Friedman-Schutz instability for exciting modes on a rotating star by emission of energy in the form of gravitational waves. However, the acoustic CFS instability differs from its gravitational wave counterpart in that the fluid medium in which the acoustic wave propagates (i.e.\\ the accretion disk) typically rotates faster than the star in which the incompressible mode is sourced. For this reason, the instability can operate even for a non-rotating star in the presence of an accretion disk. We discuss applications of o...

  12. Incompressible Modes Excited by Supersonic Shear in Boundary Layers: Acoustic CFS Instability

    Science.gov (United States)

    Belyaev, Mikhail A.

    2017-02-01

    We present an instability for exciting incompressible modes (e.g., gravity or Rossby modes) at the surface of a star accreting through a boundary layer. The instability excites a stellar mode by sourcing an acoustic wave in the disk at the boundary layer, which carries a flux of energy and angular momentum with the opposite sign as the energy and angular momentum density of the stellar mode. We call this instability the acoustic Chandrasekhar–Friedman–Schutz (CFS) instability, because of the direct analogy to the CFS instability for exciting modes on a rotating star by emission of energy in the form of gravitational waves. However, the acoustic CFS instability differs from its gravitational wave counterpart in that the fluid medium in which the acoustic wave propagates (i.e., the accretion disk) typically rotates faster than the star in which the incompressible mode is sourced. For this reason, the instability can operate even for a non-rotating star in the presence of an accretion disk. We discuss applications of our results to high-frequency quasi-periodic oscillations in accreting black hole and neutron star systems and dwarf nova oscillations in cataclysmic variables.

  13. Anisotropic mobility and carrier dynamics in the β-type BEDT-TTF salts as studied by inter-layer transverse magnetoresistance

    Directory of Open Access Journals (Sweden)

    Shigeharu Sugawara and Masafumi Tamura

    2013-01-01

    Full Text Available A new method to estimate an in-plane conduction anisotropy in a quasi-two-dimensional (q2D layered conductor by measuring the inter-layer transverse magnetoresistance is proposed. We applied this method to layered organic conductors β-(BEDT-TTF2X (BEDT-TTF = bis(ethylenedithiotetrathiafulvalene, C10H8S8; X = IBr2, I2Br by applying magnetic field rotating within the basal plane at 4.2 K. We found the anisotropic behaviour of carrier mobility μ. From this, anomalous distribution of carrier lifetime τ on the Fermi surface is derived, by the use of Fermi surface data reported for the materials. Calculations of the non-uniform susceptibility χ0(q suggest that carrier scattering is enhanced at specific k-points related to partial nesting of the Fermi surface. The present method is thus demonstrated to be an efficient experimental tool to elucidate anisotropic carrier dynamics in q2D conductors.

  14. Probing alloy composition gradient and nanometer-scale carrier localization in single AlGaN nanowires by nanocathodoluminescence

    Science.gov (United States)

    Pierret, A.; Bougerol, C.; Gayral, B.; Kociak, M.; Daudin, B.

    2013-08-01

    The optical properties of single AlGaN nanowires grown by plasma-assisted molecular beam epitaxy have been studied by nanocathodoluminescence. Optical emission was found to be position-dependent and to occur in a wide wavelength range, a feature which has been assigned to a composition gradient along the nanowire growth axis, superimposed on local composition fluctuations at the nanometer scale. This behavior is associated with the growth mode of such AlGaN nanowires, which is governed by kinetics, leading to the successive formation of (i) a zone with strong local composition fluctuations followed by (ii) a zone with a marked composition gradient and, eventually, (iii) a zone corresponding to a steady state regime and the formation of a homogeneous alloy.

  15. Improving the visible light photocatalytic activity of TiO{sub 2} by combining sulfur doping and rectorite carrier

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Xianzhong, E-mail: buxianzhongsx@163.com [College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Wang, Yang [College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Li, Ji [Shaanxi Yanchang Petroleum Mining Industry Co., Ltd., Xi’an 710075 (China); Zhang, Chonghui [College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055 (China)

    2015-04-15

    Highlights: • Dimethyl sulfoxide was used as the sources of S to prepare sulfur-doped TiO{sub 2}. • Combination of S-doping and clay carrier enhanced the photocatalytic performance of TiO{sub 2}. • Sulfur-doped TiO{sub 2}/rectorite catalysts showed high performance for photocatalytic degradation of metronidazolein under visible light irradiation. • The photocatalytic activity improvement was ascribed to the increased specific surface area, the narrowed band gap and the reduced electron–hole recombination. - Abstract: Sulfur-doped TiO{sub 2}/rectorite (STC) was prepared by an intercalation method using tetra-n-butyl titanate and dimethyl sulfoxide as the sources of Ti and S, respectively. A number of characterization methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption measurements, X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV–vis DRS) and photoluminescence spectroscopy (PL) were used to understand the properties of STC. It was found that the layer structure of rectorite was partly destroyed by intercalation, and the STC showed a looser porous lamellar structure with a large specific surface area (187.5 m{sup 2}/g). By doping S into TiO{sub 2} lattice as Ti–O–S bond, the band gap of TiO{sub 2} was reduced from 3.2 to 2.8 eV. The removal of metronidazole by the STC under visible light irradiation for 240 min reached 93.8%, which was 71.8% higher than that of P25 TiO{sub 2}. The improved photocatalytic activity was ascribed to the increased specific surface area, the narrowed band gap and the reduced electron–hole recombination.

  16. Hole traps associated with high-concentration residual carriers in p-type GaAsN grown by chemical beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Elleuch, Omar, E-mail: mr.omar.elleuch@gmail.com; Wang, Li; Lee, Kan-Hua; Demizu, Koshiro; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2015-01-28

    The hole traps associated with high background doping in p-type GaAsN grown by chemical beam epitaxy are studied based on the changes of carrier concentration, junction capacitance, and hole traps properties due to the annealing. The carrier concentration was increased dramatically with annealing time, based on capacitance–voltage (C–V) measurement. In addition, the temperature dependence of the junction capacitance (C–T) was increased rapidly two times. Such behavior is explained by the thermal ionization of two acceptor states. These acceptors are the main cause of high background doping in the film, since the estimated carrier concentration from C–T results explains the measured carrier concentration at room temperature using C–V method. The acceptor states became shallower after annealing, and hence their structures are thermally unstable. Deep level transient spectroscopy (DLTS) showed that the HC2 hole trap was composed of two signals, labeled HC21 and HC22. These defects correspond to the acceptor levels, as their energy levels obtained from DLTS are similar to those deduced from C–T. The capture cross sections of HC21 and HC22 are larger than those of single acceptors. In addition, their energy levels and capture cross sections change in the same way due to the annealing. This tendency suggests that HC21 and HC22 signals originate from the same defect which acts as a double acceptor.

  17. Relationship Between Absorber Layer Properties and Device Operation Modes For High Efficiency Thin Film Solar Cells

    Science.gov (United States)

    Ravichandran, Ram; Kokenyesi, Robert; Wager, John; Keszler, Douglas; CenterInverse Design Team

    2014-03-01

    A thin film solar cell (TFSC) can be differentiated into two distinct operation modes based on the transport mechanism. Current TFSCs predominantly exploit diffusion to extract photogenerated minority carriers. For efficient extraction, the absorber layer requires high carrier mobilities and long minority carrier lifetimes. Materials exhibiting a strong optical absorption onset near the fundamental band gap allows reduction of the absorber layer thickness to significantly less than 1 μm. In such a TFSC, a strong intrinsic electric field drives minority carrier extraction, resulting in drift-based transport. The basic device configuration utilized in this simulation study is a heterojunction TFSC with a p-type absorber layer. The diffusion/drift device operation modes are simulated by varying the thickness and carrier concentration of the absorber layer, and device performance between the two modes is compared. In addition, the relationship between device operation mode and transport properties, including carrier mobility and minority carrier lifetime are explored. Finally, candidate absorber materials that enable the advantages of a drift-based TFSC developed within the Center for Inverse Design are presented. School of Electrical Engineering and Computer Science.

  18. Photocatalytic hydrogen generation enhanced by band gap narrowing and improved charge carrier mobility in AgTaO3 by compensated co-doping.

    Science.gov (United States)

    Li, Min; Zhang, Junying; Dang, Wenqiang; Cushing, Scott K; Guo, Dong; Wu, Nianqiang; Yin, Penggang

    2013-10-14

    The correlation of the electronic band structure with the photocatalytic activity of AgTaO3 has been studied by simulation and experiments. Doping wide band gap oxide semiconductors usually introduces discrete mid-gap states, which extends the light absorption but has limited benefit for photocatalytic activity. Density functional theory (DFT) calculations show that compensated co-doping in AgTaO3 can overcome this problem by increasing the light absorption and simultaneously improving the charge carrier mobility. N/H and N/F co-doping can delocalize the discrete mid-gap states created by sole N doping in AgTaO3, which increases the band curvature and the electron-to-hole effective mass ratio. In particular, N/F co-doping creates a continuum of states that extend the valence band of AgTaO3. N/F co-doping thus improves the light absorption without creating the mid-gap states, maintaining the necessary redox potentials for water splitting and preventing from charge carrier trapping. The experimental results have confirmed that the N/F-codoped AgTaO3 exhibits a red-shift of the absorption edge in comparison with the undoped AgTaO3, leading to remarkable enhancement of photocatalytic activity toward hydrogen generation from water.

  19. High carrier mobility of Sn-doped polycrystalline-Ge films on insulators by thickness-dependent low-temperature solid-phase crystallization

    Science.gov (United States)

    Sadoh, Taizoh; Kai, Yuki; Matsumura, Ryo; Moto, Kenta; Miyao, Masanobu

    2016-12-01

    To realize the advanced thin-film transistors (TFTs), high-carrier-mobility semiconductor films on insulator structures should be fabricated with low-temperature processing conditions (≤500 °C). To achieve this, we investigated the solid-phase crystallization of amorphous-GeSn films on insulating substrates under a wide range of Sn concentrations (0%-20%), film thicknesses (30-500 nm), and annealing temperatures (380-500 °C). Our results reveal that a Sn concentration close to the solid solubility of Sn in Ge (˜2%) is effective in increasing the grain-size of poly-GeSn. In addition, we discovered that the carrier mobility depends on the film thickness, where the mobilities are determined by the counterbalance between two different carrier scattering mechanisms. Here, vacancy-related defects dominate the carrier scattering near the insulating substrates (≤˜120 nm), and grain-size determined by bulk nucleation dominates the grain-boundary scattering of thick films (≥˜200 nm). Consequently, we obtained the maximum mobilities in samples with a Sn concentration of 2% and a film thickness of 200 nm. The effect of increasing the grain-size of poly-GeSn by lowering the annealing temperature was also clarified. By combining these results, a very high carrier mobility of 320 cm2/Vs was obtained at a low temperature of 380 °C. This mobility is about 2.5 times as high as previously reported data for Ge and GeSn films grown at low temperatures (≤500 °C). Our technique therefore opens up the possibility of high-speed TFTs for use in the next generation of electronics.

  20. Development of nanostructured lipid carriers containing salicyclic acid for dermal use based on the Quality by Design method.

    Science.gov (United States)

    Kovács, A; Berkó, Sz; Csányi, E; Csóka, I

    2017-03-01

    The aim of our present work was to evaluate the applicability of the Quality by Design (QbD) methodology in the development and optimalization of nanostructured lipid carriers containing salicyclic acid (NLC SA). Within the Quality by Design methology, special emphasis is layed on the adaptation of the initial risk assessment step in order to properly identify the critical material attributes and critical process parameters in formulation development. NLC SA products were formulated by the ultrasonication method using Compritol 888 ATO as solid lipid, Miglyol 812 as liquid lipid and Cremophor RH 60® as surfactant. LeanQbD Software and StatSoft. Inc. Statistica for Windows 11 were employed to indentify the risks. Three highly critical quality attributes (CQAs) for NLC SA were identified, namely particle size, particle size distribution and aggregation. Five attributes of medium influence were identified, including dissolution rate, dissolution efficiency, pH, lipid solubility of the active pharmaceutical ingredient (API) and entrapment efficiency. Three critical material attributes (CMA) and critical process parameters (CPP) were identified: surfactant concentration, solid lipid/liquid lipid ratio and ultrasonication time. The CMAs and CPPs are considered as independent variables and the CQAs are defined as dependent variables. The 2(3) factorial design was used to evaluate the role of the independent and dependent variables. Based on our experiments, an optimal formulation can be obtained when the surfactant concentration is set to 5%, the solid lipid/liquid lipid ratio is 7:3 and ultrasonication time is 20min. The optimal NLC SA showed narrow size distribution (0.857±0.014) with a mean particle size of 114±2.64nm. The NLC SA product showed a significantly higher in vitro drug release compared to the micro-particle reference preparation containing salicylic acid (MP SA).

  1. Formation and characterization of the vortices generated by a DBD plasma actuator in burst mode

    Science.gov (United States)

    Mishra, Bal Krishan; Panigrahi, P. K.

    2017-02-01

    The present study reports the formation and evolution characteristics of the continuously generated vortical structure and resulting flow field in quiescent air induced by a dielectric-barrier-discharge (DBD) plasma actuator in burst mode operation. A starting vortex is formed during the initial actuation period, which disappears after a small time interval for continuous mode operation of the DBD plasma actuator. A burst input signal to the actuator generates a train of self-similar vortices. The behaviour of vortices and the average flow field induced by the actuator has been studied using high speed schlieren visualization and particle image velocimetry technique for different actuation amplitude and duty cycle parameters. These repeating vortices travel faster than the starting vortex, and the vortex core velocity of these repeating vortices increases with increase in duty cycle parameter. Fuller u-velocity profile, higher v-velocity near the edge of the outer shear layer region, and higher growth of the wall jet thickness is observed due to enhanced entrainment by repeating vortices for burst mode operation. The repeating vortices travel at an angle of 21° relative to the wall surface for duty cycle parameter of 90.9% in comparison to 31° for the starting vortex. Self-similarity of the velocity profile is delayed in the streamwise direction for burst mode operation in comparison to that for the continuous mode of operation. This can be attributed to delay in attaining the maximum velocity of the wall jet profile and presence of coherent structures for the burst mode operation. The non-dimensional vortex core location and size for repeating vortices follow power law fit similar to the starting vortex with difference in value of the power law exponent. The phase difference between the input voltage and current drawn is in the range of π/12 to π/9 (in radians) for both continuous and burst mode operation indicating identical electrical behaviour of the

  2. 14 CFR 298.63 - Reporting of aircraft operating expenses and related statistics by small certificated air carriers.

    Science.gov (United States)

    2010-01-01

    ... into a single classification; therefore, carriers are not required to report the fourth digit of an... equipment, amortization of capitalized leases for flight equipment, provision for obsolescence and... to all salaries in this classification. (3) Line 13 “Departure Related (Station) Expense”...

  3. Improving Urban Freight Transport Sustainability by Carriers: Best Practices from The Netherlands and the EU Project CityLog

    NARCIS (Netherlands)

    Quak, H.J.

    2012-01-01

    ers face serious challenges in making their urban freight transport efficient and sustainable. Local authorities claim that many carriers are not innovative and do not cooperate in improving their city logistics operations. There are three solution directions to make urban freight transport more eff

  4. Perimeter Governed Minority Carrier Lifetimes in 4H-SiC p(+)-n Diodes Measured by Reverse Recovery Switching Transient Analysis

    Science.gov (United States)

    Neudeck, Philip G.

    1998-01-01

    Minority carrier lifetimes in epitaxial 4H-SiC p(+)-n junction diodes were measured via an analysis of reverse recovery switching characteristics. Behavior of reverse recovery storage time (t(s)) as a function of initial ON-state forward current (I(F)) and OFF-state reverse current (I(R)) followed well-documented trends which have been observed for decades in silicon p-n rectifiers. Average minority carrier (hole) lifetimes (tau(p)) calculated from plots of t(s) vs I(R)/I(F) strongly decreased with decreasing device area. Bulk and perimeter components of average hole lifetimes were separated by plotting 1/tau(p) as a function of device perimeter-to- area ratio (P/A). This plot reveals that perimeter recombination is dominant in these devices, whose areas are all less than 1 sq mm. The bulk minority carrier (hole) lifetime extracted from the 1/tau(p) vs P/A plot is approximately 0.7 micro-s, well above the 60 ns to 300 ns average iit'eptimes obtained when perimeter recombination effects are ignored in the analysis. Given the fact that there has been little previous investigation of bipolar diode and transistor performance as a function of perimeter-to-area ratio, this work raises the possibility that perimeter recombination may be partly responsible for poor effective minority carrier lifetimes and limited performance obtained in many previous SiC bipolar junction devices.

  5. STEM mode in the SEM for the analysis of cellular sections prepared by ultramicrotome sectioning

    Science.gov (United States)

    Hondow, N.; Harrington, J.; Brydson, R.; Brown, A.

    2012-07-01

    The use of the dual imaging capabilities of a scanning electron microscope fitted with a transmitted electron detector is highlighted in the analysis of samples with importance in the field of nanotoxicology. Cellular uptake of nanomaterials is often examined by transmission electron microscopy of thin sections prepared by ultramicrotome sectioning. Examination by SEM allows for the detection of artefacts caused by sample preparation (eg. nanomaterial pull-out) and the complementary STEM mode permits study of the interaction between nanomaterials and cells. Thin sections of two nanomaterials of importance in nanotoxicology (cadmium selenide quantum dots and single walled carbon nanotubes) are examined using STEM mode in the SEM.

  6. Single-molecule electronics: Cooling individual vibrational modes by the tunneling current

    Science.gov (United States)

    Lykkebo, Jacob; Romano, Giuseppe; Gagliardi, Alessio; Pecchia, Alessandro; Solomon, Gemma C.

    2016-03-01

    Electronic devices composed of single molecules constitute the ultimate limit in the continued downscaling of electronic components. A key challenge for single-molecule electronics is to control the temperature of these junctions. Controlling heating and cooling effects in individual vibrational modes can, in principle, be utilized to increase stability of single-molecule junctions under bias, to pump energy into particular vibrational modes to perform current-induced reactions, or to increase the resolution in inelastic electron tunneling spectroscopy by controlling the life-times of phonons in a molecule by suppressing absorption and external dissipation processes. Under bias the current and the molecule exchange energy, which typically results in heating of the molecule. However, the opposite process is also possible, where energy is extracted from the molecule by the tunneling current. Designing a molecular "heat sink" where a particular vibrational mode funnels heat out of the molecule and into the leads would be very desirable. It is even possible to imagine how the vibrational energy of the other vibrational modes could be funneled into the "cooling mode," given the right molecular design. Previous efforts to understand heating and cooling mechanisms in single molecule junctions have primarily been concerned with small models, where it is unclear which molecular systems they correspond to. In this paper, our focus is on suppressing heating and obtaining current-induced cooling in certain vibrational modes. Strategies for cooling vibrational modes in single-molecule junctions are presented, together with atomistic calculations based on those strategies. Cooling and reduced heating are observed for two different cooling schemes in calculations of atomistic single-molecule junctions.

  7. Period spacing of gravity modes strongly affected by rotation. Going beyond the traditional approximation

    Science.gov (United States)

    Prat, V.; Mathis, S.; Lignières, F.; Ballot, J.; Culpin, P.-M.

    2017-02-01

    Context. As of today, asteroseismology mainly allows us to probe the internal rotation of stars when modes are only weakly affected by rotation using perturbative methods. Such methods cannot be applied to rapidly rotating stars, which exhibit complex oscillation spectra. In this context, the so-called traditional approximation, which neglects the terms associated with the latitudinal component of the rotation vector, describes modes that are strongly affected by rotation. This approximation is sometimes used for interpreting asteroseismic data, however, its domain of validity is not established yet. Aims: We aim at deriving analytical prescriptions for period spacings of low-frequency gravity modes strongly affected by rotation through the full Coriolis acceleration (i.e. without neglecting any component of the rotation vector), which can be used to probe stellar internal structure and rotation. Methods: We approximated the asymptotic theory of gravito-inertial waves in uniformly rotating stars using ray theory described in a previous paper in the low-frequency regime, where waves are trapped near the equatorial plane. We put the equations of ray dynamics into a separable form and used the Einstein-Brillouin-Keller (EBK) quantisation method to compute modes frequencies from rays. Results: Two spectral patterns that depend on stratification and rotation are predicted within this new approximation: one for axisymmetric modes and one for non-axisymmetric modes. Conclusions: The detection of the predicted patterns in observed oscillation spectra would give constraints on internal rotation and chemical stratification of rapidly rotating stars exhibiting gravity modes, such as γ Doradus, SPB, or Be stars. The obtained results have a mathematical form that is similar to that of the traditional approximation, but the new approximation takes the full Coriolis, which allows for propagation near the centre, and centrifugal accelerations into account.

  8. Model for Quasinormal Mode Excitation by a Particle Plunging into a Black Hole

    Science.gov (United States)

    Mark, Zachary; Zimmerman, Aaron; Yang, Huan; Chen, Yanbei

    2016-03-01

    It is known that the late time gravitational waveform produced by a particle plunging into a Kerr black hole is well described by a sum of quasinormal modes. However it is not yet understood how the early part of the waveform gives way to the quasinormal mode description, which diverges at early times, nor how the inhomogenous part of the waveform contributes. Motivated by, we offer a model for quasinormal mode excitation by a particle plunging into a Schwarzschild black hole. To develop our model we study approximations to the Regge-Wheeler equation that allow for a closed-form expression for the frequency-domain Green's function, which we use to isolate the component of the waveform that should be identified with quasinormal ringing. Our description of quasinormal ringing does not diverge at early times and reveals that quasinormal ringing should be understood in analogy with a damped harmonic oscillator experiencing a transient driving source.

  9. Period spacing of gravity modes strongly affected by rotation. Going beyond the traditional approximation

    CERN Document Server

    Prat, Vincent; Lignières, François; Ballot, Jérôme; Culpin, Pierre-Marie

    2016-01-01

    Context. As of today, asteroseismology mainly allows us to probe internal rotation of stars when modes are only weakly affected by rotation using perturbative methods. Such methods cannot be applied to rapidly rotating stars, which exhibit complex oscillation spectra. In this context, the so-called traditional approximation, which neglects the terms associated with the latitudinal component of the rotation vector, describes modes that are strongly affected by rotation and is sometimes used for interpreting asteroseismic data. However, its domain of validity is not established yet. Aims. We aim at deriving analytical prescriptions for period spacings of low-frequency gravity modes strongly affected by rotation through the full Coriolis acceleration that can be used to probe stellar internal structure and rotation. Methods. The asymptotic theory of gravito-inertial waves in uniformly rotating stars using ray theory described by Prat et al. (2016, A&A, 587, A110) is approximated in the low-frequency regime, ...

  10. Scaling the Mode Shapes of a Building Model by Mass Changes

    DEFF Research Database (Denmark)

    Brincker, Rune; Rodrigues, J.; Andersen, P.

    2004-01-01

    It is well known, that when using natural input modal analysis, the loads are not known, and thus, the mode scaling factor that relates the magnitude of the loading to the magnitude of the response cannot be estimated. However It has been pointed out by several theoretical papers that mode shapes...... change technique can be used on a ¼ scale model of a 4-storey building. The uncertainties on the estimated scaling factors are illustrated by repeating the estimation using different mass changes....... can be scaled by performing  several natural input modal analysis tests with different mass changes, observe the frequency shift introduced by the mass changes and then follow an estimation scheme that allows the user to estimate the scaling factor modeby- mode, i.e. only information of the particular...

  11. Angular momentum redistribution by mixed modes in evolved low-mass stars. II. Spin-down of the core of red giants induced by mixed modes

    CERN Document Server

    Belkacem, K; Goupil, M J; Mosser, B; Sonoi, T; Ouazzani, R M; Dupret, M A; Mathis, S; Grosjean, M

    2015-01-01

    The detection of mixed modes in subgiants and red giants by the CoRoT and \\emph{Kepler} space-borne missions allows us to investigate the internal structure of evolved low-mass stars. In particular, the measurement of the mean core rotation rate as a function of the evolution places stringent constraints on the physical mechanisms responsible for the angular momentum redistribution in stars. It showed that the current stellar evolution codes including the modelling of rotation fail to reproduce the observations. An additional physical process that efficiently extracts angular momentum from the core is thus necessary. Our aim is to assess the ability of mixed modes to do this. To this end, we developed a formalism that provides a modelling of the wave fluxes in both the mean angular momentum and the mean energy equations in a companion paper. In this article, mode amplitudes are modelled based on recent asteroseismic observations, and a quantitative estimate of the angular momentum transfer is obtained. This i...

  12. Growth Related Carrier Mobility Enhancement of Pentacene Thin-Film Transistors with High-k Oxide Gate Dielectric

    Institute of Scientific and Technical Information of China (English)

    YU Ai-Fang; QI Qiong; JIANG Peng; JIANG Chao

    2009-01-01

    Carrier mobifity enhancement from 0.09 to 0.59cm2/Vs is achieved for pentacene-based thin-film transistors (TFTs) by modifying the HfO2 gate dielectric with a polystyrene (PS) thin film. The improvement of the transistor's performance is found to be strongly related to the initial film morphologies of pentacene on the dielectrics. In contrast to the three-dimensional island-like growth mode on the HfO2 surface, the Stranski-Krastanov growth mode on the smooth and nonpolar PS/HfO2 surface is believed to be the origin of the excellent carrier mobifity of the TFTs. A large well-connected first monolayer with fewer boundaries is formed via the Stranski-Krastanov growth mode, which facilitates a charge transport parallel to the substrate and promotes higher carrier mobility.

  13. Co-composted biochar can promote plant growth by serving as a nutrient carrier: first mechanistic insights

    Science.gov (United States)

    Kammann, Claudia; Haider, Ghulam; Messerschmidt, Nicole; Schmidt, Hans-Peter; Koyro, Hans-Werner; Steffens, Diedrich; Clough, Timothy; Müller, Christoph

    2014-05-01

    Pyrogenic carbon (biochar) offers considerable potential for carbon capture (CCSS) and soil storage and meta-analysis suggests that it can significantly reduce soil N2O emissions. Freshly produced biochars, however, do not always have yield-improving effects; pure, production-fresh biochar seems to 'claim' some nutrients initially from soil, particularly nitrogen, although the mechanisms are unclear to date. Hence, combining biochar with organic nutrient-rich materials and waste streams may be a promising strategy to enable CCSS by yield improvements, which may enable economically feasible biochar use in agriculture. We explored the potential of organically post-treated biochar to act as a nutrient carrier and thus to increase its socio-economic value as beneficial soil amendment with associated CCSS value. In a first proof-of-concept study the effects of untreated biochar were compared to those of co-composted biochar, combined with stepwise improved nutritional regimes (+/- compost; +/- mineral-N application). While the untreated biochar reduced plant growth under N-limiting conditions, or at best did not reduce it, the co-composted biochar always significantly stimulated plant growth. The relative stimulation was largest with the lowest nutrient additions (305% versus 61% of control with untreated biochar). Subsequent electro-ultra-filtration analyses revealed that the co-composted but not the untreated biochar carried considerable amounts of easily extractable as well as more strongly sorbed plant nutrients, in particular nitrate and phosphorus. Nevertheless the co-composted N-rich biochar still sorbed 15N labelled NH4+ or NO3- when present in the soil, and again released it to growing barley plants. We will report on the relationship between particle size, increased nutrient content, and plant accessibility of the nutrients associated with the co-composted biochar, and analyse the extent to which the strongly sorbed nutrients on the biochar may be 'invisible

  14. Rescuing compound bioactivity in a secondary cell-based screening by using γ-cyclodextrin as a molecular carrier

    Science.gov (United States)

    Claveria-Gimeno, Rafael; Vega, Sonia; Grazu, Valeria; de la Fuente, Jesús M; Lanas, Angel; Velazquez-Campoy, Adrian; Abian, Olga

    2015-01-01

    In vitro primary screening for identifying bioactive compounds (inhibitors, activators or pharmacological chaperones) against a protein target results in the discovery of lead compounds that must be tested in cell-based efficacy secondary screenings. Very often lead compounds do not succeed because of an apparent low potency in cell assays, despite an excellent performance in primary screening. Primary and secondary screenings differ significantly according to the conditions and challenges the compounds must overcome in order to interact with their intended target. Cellular internalization and intracellular metabolism are some of the difficulties the compounds must confront and different strategies can be envisaged for minimizing that problem. Using a novel screening procedure we have identified 15 compounds inhibiting the hepatitis C NS3 protease in an allosteric fashion. After characterizing biophysically the interaction with the target, some of the compounds were not able to inhibit viral replication in cell assays. In order to overcome this obstacle and potentially improve cellular internalization three of these compounds were complexed with γ-cyclodextrin. Two of them showed a five- and 16-fold activity increase, compared to their activity when delivered as free compounds in solution (while γ-cyclodextrin did not show antiviral activity by itself). The most remarkable result came from a third compound that showed no antiviral activity in cell assays when delivered free in solution, but its γ-cyclodextrin complex exhibited a 50% effective concentration of 5 μM. Thus, the antiviral activity of these compounds can be significantly improved, even completely rescued, using γ-cyclodextrin as carrier molecule. PMID:25834436

  15. Enhanced growth and recombinant protein production of Escherichia coli by a perfluorinated oxygen carrier in miniaturized fed-batch cultures

    Directory of Open Access Journals (Sweden)

    Neubauer Peter

    2011-06-01

    Full Text Available Abstract Background Liquid perfluorochemicals (PFCs are interesting oxygen carriers in medicine and biotechnology with a high solubility for oxygen. They have been repeatedly used for improving oxygen transfer into prokaryotic and eukaryotic cell cultures, however their application is still limited. Here we show the great benefit of air/oxygen saturated perfluorodecalin (PFD for high cell density cultivation of Escherichia coli in microwell plates and their positive effect on the soluble production of a correctly folded heterologously expressed alcohol dehydrogenase. Results In EnBase® cultivations the best effect was seen with PFD saturated with oxygen enriched air (appr. 10 μM oxygen per ml when PFD was added at the time of induction. In contrast the effect of PFD was negligible when it was added already at the time of inoculation. Optimisation of addition time and content of loaded oxygen into the PFD resulted in an increased the cell density by 40% compared to control cultures, and correspondingly also the product yield increased, demonstrated at the example of a recombinant alcohol dehydrogenase. Conclusions PFCs are a valuable additive in miniaturized cell culture formats. For production of recombinant proteins in low cell density shaken cultures the addition of oxygen-enriched PFD makes the process more robust, i.e. a high product yield is not any more limited to a very narrow cell density window during which the induction has to be done. The positive effect of PFD was even more obvious when it was added during high cell density cultures. The effect of the PFD phase depends on the amount of oxygen which is loaded into the PFD and which thus is a matter of optimisation.

  16. Dual mode cobaloxime crystals: Acceleration of trans-cis photochromic reaction rate by photoisomerization

    Science.gov (United States)

    Sekine, Akiko

    2016-08-01

    Our recent results on the photochromic reactions in dual mode cobaloxime crystals containing azobenzene derivatives are briefly reviewed. This work represents the first step toward the design of functional materials which can be controlled by two independent external stimuli, one by visible light and the other by UV radiation.

  17. The g-mode Excitation in the Proto Neutron Star by the Standing Accretion Shock Instability

    CERN Document Server

    Yoshida, S; Yamada, S; Yoshida, Shijun; Ohnishi, Naofumi; Yamada, Shoichi

    2007-01-01

    The so-called "acoustic revival mechanism" of core-collapse supernova proposed recently by the Arizona group is an interesting new possibility. Aiming to understand the elementary processes involved in the mechanism, we have calculated the eigen frequencies and eigen functions for the g-mode oscillations of a non-rotating proto neutron star. The possible excitation of these modes by the standing accretion shock instability, or SASI, is discussed based on these eigen functions. We have formulated the forced oscillations of $g$-modes by the external pressure perturbations exerted on the proto neutron star surface. The driving pressure fluctuations have been adopted from our previous computations of the axisymmetric SASI in the non-linear regime. We have paid particular attention to low l modes, since these are the modes that are dominant in SASI and that the Arizona group claimed played an important role in their acoustic revival scenario. Here l is the index of the spherical harmonic functions, $Y_l^m$. Althou...

  18. Design and experiments of a linear piezoelectric motor driven by a single mode

    Science.gov (United States)

    Liu, Zhen; Yao, Zhiyuan; Li, Xiang; Fu, Qianwei

    2016-11-01

    In this contribution, we propose a novel linear piezoelectric motor with a compact stator that is driven by a single mode. The linear piezoelectric motor can realize bidirectional motion by changing the vibration modes of the stator. Finite element analysis is performed to determine the required vibration mode of the stator and obtain the optimal stator structure and dimensions. Furthermore, the trajectories of the driving foot are analyzed with and without consideration of the mechanical contact with the slider. It is shown that the trajectory of the driving foot is an oblique line when disregarding the contact, and the trajectory becomes an oblique ellipse while taking into account the contact. Finally, a prototype of the motor is fabricated based on the results of finite element analysis. The optimization results show that the motor reaches its maximum thrust force of 4.0 kg, maximum thrust-weight ratio of 33.3, maximum unloaded velocity of 385 mm/s under the excitation of Mode-B, and maximum unloaded velocity of 315 mm/s under the excitation of Mode-L.

  19. Compressive sensing based spinning mode detections by in-duct microphone arrays

    Science.gov (United States)

    Yu, Wenjun; Huang, Xun

    2016-05-01

    This paper presents a compressive sensing based experimental method for detecting spinning modes of sound waves propagating inside a cylindrical duct system. This method requires fewer dynamic pressure sensors than the number required by the Shannon-Nyquist sampling theorem so long as the incident waves are sparse in spinning modes. In this work, the proposed new method is firstly validated by preparing some of the numerical simulations with representative set-ups. Then, a duct acoustic testing rig with a spinning mode synthesiser and an in-duct microphone array is built to experimentally demonstrate the new approach. Both the numerical simulations and the experiment results are satisfactory, even when the practical issue of the background noise pollution is taken into account. The approach is beneficial for sensory array tests of silent aeroengines in particular and some other engineering systems with duct acoustics in general.

  20. Dispersion peculiarities of hybrid modes in a uniaxial waveguide filled by a gyroelectromagnetic medium

    CERN Document Server

    Tuz, Vladimir R; Fesenko, Volodymyr I; Sun, Hong-Bo; Shulga, Valeriy M; Wei, Han

    2016-01-01

    Extraordinary dispersion features of a circular waveguide filled by a longitudinally magnetized composite gyroelectromagnetic medium are studied. The composite medium is considered to be constructed by juxtaposition together of magnetic and semiconductor layers providing all characteristic dimensions of the resulting multilayered system are much smaller than the wavelength in the corresponding part of the composite medium. The waveguide dispersion equation and its eigenmodes are derived. The mode classification is made in a standard manner so that the guided modes are sorted into a class of hybrid HE and EH waves in terms of their unique dispersion characteristics. The numerical results are obtained in the band near the frequencies of corresponding resonances in constitutive materials of the composite medium, and they show that the modes behaviors become to be quite diverse due to manifestation of a strong combined geometrical and material dispersion related to the waveguide parameters and gyroelectromagnetic...

  1. High Resolution Mode-Selective Excitation by Adaptive Femtosecond Pulse Shaping

    Institute of Scientific and Technical Information of China (English)

    LI Xia; ZHANG Hui; ZHANG Xiang-Yun; ZHANG Shi-An; CHEN Guo-Liang; WANG Zu-Geng; SUN Zhen-Rong

    2008-01-01

    High resolution mode-selective excitation in the mixture of C6H6(992cm-1)and C6D6(945cm-1)is experimentally achieved by adaptive femtosecond pulse shaping based on the genetic algorithm(GA),and second harmonic generation frequency-resolved optical gating(SHG-FROG)is adopted to characterize the original and optimal laser pulses,and its mechanism is experimentally validated by tailoring the frequency components of the pump pulses at the Fourier plane.It is indicated that two-pulse coherent mode-selective excitation of the Raman scattering mainly depends on the effective frequency components of the pump pulse related to specific molecular vibrational mode.The experimental results have attractive potential appfications in the complicated molecular system.

  2. High order sliding mode control of a DFIM supplied by two power inverters

    Directory of Open Access Journals (Sweden)

    Zinelaabidine Boudjema

    2015-06-01

    Full Text Available Traditional vector control structures which include proportional-integral (PI regulator for the speed of a doubly fed induction motor (DFIM driven have some disadvantages such as parameter tuning complications, mediocre dynamic performances and reduced robustness. Thus, based on the analysis of the mathematical model of a DFIM supplied by two indirect inverters, this paper addresses a nonlinear control algorithm based on high order sliding mode. The conventional sliding mode control has large chattering on the electromagnetic torque developed by the DFIM. In order to solve this problem, the second order sliding mode technique is used. The simulation results show the effectiveness of the proposed method especially in chattering-free behavior, response to sudden load torque variations and robustness against machine parameters variations.

  3. Detection of phonon and phason modes in intrinsic colloidal quasicrystals by reconstructing their structure in hyperspace

    Science.gov (United States)

    Hielscher, J.; Martinsons, M.; Schmiedeberg, M.; Kapfer, S. C.

    2017-03-01

    Phasons are additional degrees of freedom which occur in quasicrystals alongside the phonons known from conventional periodic crystals. The rearrangements of particles that are associated with a phason mode are hard to interpret in physical space. We reconstruct the quasicrystal structure by an embedding into extended higher-dimensional space, where phasons correspond to displacements perpendicular to the physical space. In dislocation-free decagonal colloidal quasicrystals annealed with Brownian dynamics simulations, we identify thermal phonon and phason modes. Finite phononic strain is pinned by phasonic excitations even after cooling down to zero temperature. For the phasonic displacements underlying the flip pattern, the reconstruction method gives an approximation within the limits of a multi-mode harmonic ansatz, and points to fundamental limitations of a harmonic picture for phasonic excitations in intrinsic colloidal quasicrystals.

  4. Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

    Science.gov (United States)

    Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

    2005-02-28

    Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

  5. Stochastic differential equations with variable structure driven by multiplicative Gaussian noise and sliding mode dynamic

    OpenAIRE

    Barbu, Viorel; Bonaccorsi, Stefano; Tubaro, Luciano

    2015-01-01

    This work is concerned with existence of weak solutions to discon- tinuous stochastic differential equations driven by multiplicative Gaus- sian noise and sliding mode control dynamics generated by stochastic differential equations with variable structure, that is with jump nonlin- earity. The treatment covers the finite dimensional stochastic systems and the stochastic diffusion equation with multiplicative noise.

  6. Observation of wedge waves and their mode transformation by laser ultrasonic technique

    Institute of Scientific and Technical Information of China (English)

    Jing Jia; Zhonghua Shen; Lijuan Wang; Ling Yuan

    2011-01-01

    Wedge waves (WWs) in wedges, including their dispersion characteristics and mode transformation, are investigated using the laser ultrasound technique. Pulsed laser excitation and optical deflection beam method for detection are used to record WWs. Numerous WWs are detected by scanning the excitation laser along the wedge tip. Dispersions of WWs are obtained by using the two-dimensional (2D) Fourier transformation method, and different WW orders are revealed on the wedges. Mode transformation is determined by fixing the distance between the excitation and detection position, as well as by scanning the samples along the normal direction of the wedge tip.%@@ Wedge waves (WWs) in wedges, including their dispersion characteristics and mode transformation, are investigated using the laser ultrasound technique. Pulsed laser excitation and optical deflection beam method for detection are used to record WWs. Numerous WWs are detected by scanning the excitation laser along the wedge tip. Dispersions of WWs are obtained by using the two-dimensional (2D) Fourier transformation method, and different WW orders are revealed on the wedges. Mode transformation is determined by fixing the distance between the excitation and detection position, as well as by scanning the samples along the normal direction of the wedge tip.

  7. Proton acceleration by RF TE{sub 11} mode in a cylindrical cavity

    Energy Technology Data Exchange (ETDEWEB)

    Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Masuda, Kai [Kyoto Univ., Uji (Japan). Inst. of Advanced Energy

    1997-03-01

    We found that protons are accelerated significantly by RF TE{sub 11} mode in a cylindrical cavity. In this method, protons get the perpendicular kinetic energy, so we thought it might be a compact accelerator, and studied the feasibility by numerical simulation. (author)

  8. 76 FR 32390 - Motor Carrier Safety Advisory Committee Public Meeting

    Science.gov (United States)

    2011-06-06

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of Motor Carrier Safety Advisory... MCSAC will complete action on Task 11-01, regarding Patterns of Safety Violations by Motor...

  9. Mode Modification of Plasmonic Gap Resonances induced by Strong Coupling with Molecular Excitons

    CERN Document Server

    Chen, Xingxing; Qin, Jian; Zhao, Ding; Ding, Boyang; Blaikie, Richard J; Qiu, Min

    2016-01-01

    Plasmonic cavities can be used to control the atom-photon coupling process at the nanoscale, since they provide ultrahigh density of optical states in an exceptionally small mode volume. Here we demonstrate strong coupling between molecular excitons and plasmonic resonances (so-called plexcitonic coupling) in a film-coupled nanocube cavity, which can induce profound and significant spectral and spatial modifications to the plasmonic gap modes. Within the spectral span of a single gap mode in the nanotube-film cavity with a 3-nm wide gap, the introduction of narrow-band J-aggregate dye molecules not only enables an anti-crossing behavior in the spectral response, but also splits the single spatial mode into two distinct modes that are easily identified by their far-field scattering profiles. Simulation results confirm the experimental findings and the sensitivity of the plexcitonic coupling is explored using digital control of the gap spacing. Our work opens up a new perspective to study the strong coupling pr...

  10. Laser ultrasonic analysis of normal modes generated by a voltage pulse on an AT quartz sensor.

    Science.gov (United States)

    Goossens, Jozefien; Martinez, Loïc; Glorieux, Christ; Wilkie-Chancellier, Nicolas; Ehssein, Chighali Ould; Serfaty, Stéphane

    2006-12-22

    Laser ultrasonic detection is a versatile and highly sensitive tool for the observation of surface waves. In the following study, laser ultrasonic detection is used for the experimental study of spurious normal vibration modes of a disk quartz sensor excited by a voltage pulse. The AT cut crystal (cut of the crystal relative to the the main crystallographic axis is 35.25 degrees) is optimal for generating mainly thickness-shear vibrations (central frequency 6 MHz) on the quartz surface. However, resulting from shear-to-longitudinal and shear-to-surface mode conversion, and from the weak coupling with the other crystallographic axes, other modes (thickness-compressional and bending modes) are always present in the plate response. Since the laser vibrometer is sensitive to normal displacements, the laser investigation shows waves that can be considered as unwanted for the AT quartz used as a shear sensor. The scanned three dimensional (3D) amplitude-space-time signals are carefully analysed using their representation in three dual Fourier domains (space-time, wave number-frequency). Results on the transient analysis of the waves, the normal bending modes and the dispersion curves are shown.

  11. Dynamical co-existence of excitons and free carriers in perovskite probed by density-resolved fluorescent spectroscopic method

    CERN Document Server

    Wang, Wei; Wang, Xiangyuan; Lv, Yanping; Wang, Shufeng; Wang, Kai; Shi, Yantao; Xiao, Lixin; Chen, Zhijian; Gong, Qihuang

    2016-01-01

    Using transient fluorescent spectra at time-zero, we develop a density-resolved fluorescent spectroscopic method for investigating photoproducts in CH3NH3PbI3 perovskite and related photophysics. The density dependent dynamical co-existence of excitons and free carriers over a wide density range is experimentally observed for the first time. The exciton binding energy (EB) and the effective mass of electron-hole pair can be estimated based on such co-existence. No ionic polarization is found contributing to photophysical behavior. It also solves the conflict between the large experimentally measured EB and the small predicted values. The spectroscopic method also helps to detect the true free carrier density under continuous illumination without the interference of ionic conductivity. Our methods and results profoundly enrich the study and understanding of the photophysics in perovskite materials for photovoltaic applications.

  12. The potential of sugar cane juice as the liquid supplement and phytase enzyme carrier for poultry by in vitro

    Directory of Open Access Journals (Sweden)

    Ermin Widjaja

    2011-12-01

    Full Text Available Most of the components of poultry feed (80% of grains and meal that contains phytic acid which has anti-nutritional factor because it can bind minerals and reduce its availability. Phytic acid can be hydrolyzed by the enzyme phytase. Phytase enzyme naturally found in sugar cane juice, but its use as poultry feed supplements have not been done. The study was conducted using sugar cane juice PS 851 from Jatiroto PTPN XI, Lumajang, East Java in order to get the information potential of sugar cane juice as a liquid supplement and phytase enzyme carrier for poultry viewed from the aspect of nutrient content of sugarcane juice and phytase activity in the release rate of phosphorus. Research conducted at the Faculty of Animal IPB for 10 months. The rate of hydrolysis of phytase on P was tested using rice bran as a substrate. Sugar cane juice is added to the 2.5% level, using 4-level incubation (1, 2, 3 and 4 hours, each level consisting of 37°C and 42°C; pH 2; pH 4.5 and pH 5 with three replications. Study using a Two Factors Experiments in Completely Randomized Design and it was continued by DMRT test. P release rate was measured by spectrophotometry. The results showed that the sugar cane juice has a phytase activity of 0.0766 U / ml, brix level of 22.15%, containing water 73.03%, protein 0.47%, crude fiber 6.43%, minerals Ca 0.03%, P 0,02%, Co 0.14 mg / l, Fe 1.8 mg/l, Mn 1.55 mg/l, Zn 1.37 mg/ l, Cu 0.19 mg/ l, Se 12.63 mcg/100 g, vitamins B3 5.26 mg/100 g, C 0.72 mg/100 g, E 0.08 mg/100 g, sucrose 32.42%, fructose 2.41%, galactose 2% and glucose 1.58%. Supplementation of 2.5% sugar cane juice can increase the P release rate of 112-235% at optimum conditions of pH 5, at 37°C with a long incubation period of 1-4 hours.

  13. Quantum dot based detections of propagating plasmonic modes excited by bowtie antennas

    Science.gov (United States)

    Wen, Jing; Wang, Kang; Feng, Hui; Lv, Yating; Chen, Jiannong; Zhang, Dawei

    2017-03-01

    Propagating plasmonic modes excited by bowtie apertures based on emissions from a layer of CdSe/ZnS quantum dots are experimentally detected. The mode distributions with a cladding of 20 nm thick Al2O3 film in between the silver and the quantum dot layers are more homogenous compared to the uncoated structure. The variation discipline of the effective indexes and the decay lengths of the plasmonic modes are discussed for various refractive indexes and thicknesses of the cladding. The three dimensional field distributions of the structure are simulated and the plasmonic fields are only excited in and around the cladding layer on top of the silver film. Such quantum dots based detection methods are promising tools for simultaneous imaging of near field optical distributions in integrated plasmonic nano-circuits.

  14. InAs nanowire growth modes on Si (111) by gas source molecular beam epitaxy

    Science.gov (United States)

    Robson, M. T.; LaPierre, R. R.

    2016-02-01

    InAs nanowires (NWs) were grown on silicon substrates by gas source molecular beam epitaxy using five different growth modes: (1) Au-assisted growth, (2) positioned (patterned) Au-assisted growth, (3) Au-free growth, (4) positioned Au-assisted growth using a patterned oxide mask, and (5) Au-free selective-area epitaxy (SAE) using a patterned oxide mask. Optimal growth conditions (temperature, V/III flux ratio) were identified for each growth mode for control of NW morphology and vertical NW yield. The highest yield (72%) was achieved with the SAE method at a growth temperature of 440 °C and a V/III flux ratio of 4. Growth mechanisms are discussed for each of the growth modes.

  15. FTO films deposited in transition and oxide modes by magnetron sputtering using tin metal target.

    Science.gov (United States)

    Liao, Bo-Huei; Chan, Shih-Hao; Lee, Cheng-Chung; Kuo, Chien-Cheng; Chen, Sheng-Hui; Chiang, Donyau

    2014-02-01

    Fluorine-doped tin oxide (FTO) films were prepared by pulsed DC magnetron sputtering with a metal Sn target. Two different modes were applied to deposit the FTO films, and their respective optical and electrical properties were evaluated. In the transition mode, the minimum resistivity of the FTO film was 1.63×10(-3)  Ω cm with average transmittance of 80.0% in the visible region. Furthermore, FTO films deposited in the oxide mode and mixed simultaneously with H2 could achieve even lower resistivity to 8.42×10(-4)  Ω cm and higher average transmittance up to 81.1% in the visible region.

  16. Slow Light by Modified Reservoir Induced Transparency with a Non-Singular Density of Modes

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bo; DU Chun-Guang; LI Shi-Qun

    2004-01-01

    @@ We investigate the dispersive property of a A-type atomic system embedded in photonic band gap structures.The atomic coherence is established by the structured reservoir which consists of a double-band photonic band gap (PBG) and defect modes. With an atomic density of 7 × 1015 atoms/cm3, the group velocity of a probe laser being detuned far away from the gap is shown to be reduced to 3 × 102 m/s near the transparency window associated with the PBG edges and 6 × 103 m/s at the transparency window associated with the defect modes, without using any deriving field. The influence of the smoothness of the density of modes and the decay rate of the second ground state of atoms are analysed.

  17. Image characterization by fractal descriptors in variational mode decomposition domain: Application to brain magnetic resonance

    Science.gov (United States)

    Lahmiri, Salim

    2016-08-01

    The main purpose of this work is to explore the usefulness of fractal descriptors estimated in multi-resolution domains to characterize biomedical digital image texture. In this regard, three multi-resolution techniques are considered: the well-known discrete wavelet transform (DWT) and the empirical mode decomposition (EMD), and; the newly introduced; variational mode decomposition mode (VMD). The original image is decomposed by the DWT, EMD, and VMD into different scales. Then, Fourier spectrum based fractal descriptors is estimated at specific scales and directions to characterize the image. The support vector machine (SVM) was used to perform supervised classification. The empirical study was applied to the problem of distinguishing between normal and abnormal brain magnetic resonance images (MRI) affected with Alzheimer disease (AD). Our results demonstrate that fractal descriptors estimated in VMD domain outperform those estimated in DWT and EMD domains; and also those directly estimated from the original image.

  18. Directional fluorescence emission by individual V-antennas explained by mode expansion.

    Science.gov (United States)

    Vercruysse, Dries; Zheng, Xuezhi; Sonnefraud, Yannick; Verellen, Niels; Di Martino, Giuliana; Lagae, Liesbet; Vandenbosch, Guy A E; Moshchalkov, Victor V; Maier, Stefan A; Van Dorpe, Pol

    2014-08-26

    Specially designed plasmonic antennas can, by far-field interference of different antenna elements or a combination of multipolar antenna modes, scatter light unidirectionally, allowing for directional light control at the nanoscale. One of the most basic and compact geometries for such antennas is a nanorod with broken rotational symmetry, in the shape of the letter V. In this article, we show that these V-antennas unidirectionally scatter the emission of a local dipole source in a direction opposite the undirectional side scattering of a plane wave. Moreover, we observe high directivity, up to 6 dB, only for certain well-defined positions of the emitter relative to the antenna. By employing a rigorous eigenmode expansion analysis of the V-antenna, we fully elucidate the fundamental origin of its directional behavior. All findings are experimentally verified by measuring the radiation patterns of a scattered plane wave and the emission pattern of fluorescently doped PMMA positioned in different regions around the antenna. The fundamental interference effects revealed in the eigenmode expansion can serve as guidelines in the understanding and further development of nanoscale directional scatterers.

  19. Factors Determining the Mode of Overseas R&D by Multinationals: Empirical Evidence

    OpenAIRE

    Ito, Banri; Wakasugi, Ryuhei

    2007-01-01

    The large expansion of MNCs' overseas R&D is noteworthy. This paper investigates the factors affecting the expansion of support-oriented R&D and knowledge sourcing R&D by using qualitative data which indicate the modes of R&D conducted at a plant site and a laboratory. The empirical results suggest that (1) the export propensity of affiliate firms, relative abundance of human resources for R&D, and accumulated technological knowledge have a positive effect on both the modes of R&D at a plant ...

  20. Enhanced detection limit by dark mode perturbation in 2D photonic crystal slab refractive index sensors.

    Science.gov (United States)

    Nicolaou, Costa; Lau, Wah Tung; Gad, Raanan; Akhavan, Hooman; Schilling, Ryan; Levi, Ofer

    2013-12-16

    We demonstrate for the first time a 300nm thick, 300μm × 300μm 2D dielectric photonic crystal slab membrane with a quality factor of 10,600 by coupling light to slightly perturbed dark modes through alternating nano-hole sizes. The newly created fundamental guided resonances greatly reduce nano-fabrication accuracy requirements. Moreover, we created a new layer architecture resulting in electric field enhancement at the interface between the slab and sensing regions, and spectral sensitivity of >800 nm/RIU, that is, >0.8 of the single-mode theoretical upper limit of spectral sensitivity.

  1. Polarization dynamics in dissipative soliton fiber lasers mode-locked by nonlinear polarization rotation.

    Science.gov (United States)

    Kong, Lingjie; Xiao, Xiaosheng; Yang, Changxi

    2011-09-12

    We numerically studied the polarization dynamics in dissipative soliton lasers mode-locked by nonlinear polarization rotation (NPR). It was found that the polarization states of the intracavity dissipative soliton vary with time across the pulse. Depending on output coupling ratios, the polarization states of the pulse peak before the polarizer can be either nearly circular or nearly linear polarizations. The polarization dependent component in NPR is found to play a role of spectral filter under high and medium output coupling. However, NPR may work as a weak optical limiter under low output coupling, when additional spectral filtering is necessary to maintain steady mode-locking state.

  2. Bounce-Averaged Acceleration of Energetic Electrons by Whistler Mode Chorus in the Magnetosphere

    Institute of Scientific and Technical Information of China (English)

    XIAO Fu-Liang; CHEN Liang-Xu; ZHOU Qing-Hua; HE Hui-Yong; WEN Yong-Jun

    2007-01-01

    @@ We construct the bounce-averaged diffusion coefficients and study the bounce-averaged acceleration for energetic electrons in gyroresonance with whistler mode chorus. Numerical calculations have been performed for a band of chorus frequency distributed over a standard Gaussian spectrum specifically in the region near L = 4.5, where peaks of the electron phase space density occur. It is found that whistler mode chorus can efficiently accelerate electrons and can increase the phase space density at energies of about 1 MeV by more than one order of magnitude about one day, in agreement with the satellite observations during the recovery phase of magnetic storms.

  3. Efficient mode conversion in an optical nanoantenna mediated by quantum emitters

    CERN Document Server

    Straubel, Jakob; Rockstuhl, Carsten; Slowik, Karolina

    2016-01-01

    Converting signals between different electromagnetic modes is an asset for future information technologies. In general, slightly asymmetric optical nanoantennas enable the coupling between bright and dark modes sustained by an optical nanoantenna. However, the conversion efficiency might be very low. Here, we show that the additional incorporation of a quantum emitter allows to tremendously enhance this efficiency. The enhanced local density of states cycles the quantum emitter between its upper and lower level at an extremely hight rate; hence converting the energy very efficient. The process is robust with respect to possible experimental tolerances and adds a new ingredient to be exploited while studying and applying coupling phenomena in optical nanosystems.

  4. Pulse shaping in mode-locked fiber lasers by in-cavity spectral filter.

    Science.gov (United States)

    Boscolo, Sonia; Finot, Christophe; Karakuzu, Huseyin; Petropoulos, Periklis

    2014-02-01

    We numerically show the possibility of pulse shaping in a passively mode-locked fiber laser by inclusion of a spectral filter into the laser cavity. Depending on the amplitude transfer function of the filter, we are able to achieve various regimes of advanced temporal waveform generation, including ones featuring bright and dark parabolic-, flat-top-, triangular- and saw-tooth-profiled pulses. The results demonstrate the strong potential of an in-cavity spectral pulse shaper for controlling the dynamics of mode-locked fiber lasers.

  5. Avoidance of Tearing Mode Locking and Disruption with Electro-Magnetic Torque Introduced by Feedback-based Mode Rotation Control in DIII-D and RFX-mod

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, M. [PPPL; Zanca, P. [Euratom-ENEA; Strait, E. J. [General Atomics

    2014-09-01

    Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a very promising scheme to avoid such disruptions by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque to the modes is created by a toroidal phase shift between the externally-applied field and the excited TM fields, compensating for the mode momentum loss due to the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two vastly different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high βN plasmas in a non-circular divertor tokamak. In RFX-mod, the plasma was ohmically-heated plasma with ultralow safety factor in a circular limiter discharge of active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited to this purpose.

  6. Ex-situ and in-situ investigations of thermal anti-oxidation treatments of stainless steels by reflection mode EXAFS

    Science.gov (United States)

    Lützenkirchen-Hecht, D.; Wulff, D.; Wagner, R.; Holländer, U.; Maier, HJ; Frahm, R.

    2016-05-01

    Different thermal treatments were performed for the anti-oxidation of steel surfaces, and the processes were investigated ex-situ and in-situ by surface sensitive reflection mode EXAFS experiments at the Cr and Fe K-edges. While the samples for the ex-situ studies were heat-treated in a conveyor belt furnace at temperatures between 600 and 900 °C in inert carrier gases (N2 or Ar) using different additives such as hydrogen (H2) and monosilane (SiH4), the in- situ anti-oxidation treatments have been performed in a high vacuum environment (p < 10-6 mbar). While the ex-situ experiments suggest that SiH4-additives are needed for the reduction of the steel to a metallic state, the in-vacuum treatments appear successful for temperatures above approx. 900 °C.

  7. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  8. Resonance modes in optical fibres

    Institute of Scientific and Technical Information of China (English)

    余寿绵; 余恬

    2002-01-01

    The weakly nonlinear boundary value problem of wave propagation in an optical fibre (for the transverse electric mode, for example) is formulated and a modified linear solution is obtained. It is shown that a self-consistent theory of fibre optics should be weakly nonlinear. The mode of critical refraction that does not exist in the linear theory is obtained, showing that it is a mode consisting of resonance modes. It is shown that the signal carriers in a long fibre are of resonance modes, not normal modes. Some experimental data are given for comparison with the theoretical predictions, and the agreement seems satisfactory.

  9. Tuning THz emission properties of Bi2Sr2CaCu2O8+δ intrinsic Josephson junction stacks by charge carrier injection

    Science.gov (United States)

    Kizilaslan, O.; Rudau, F.; Wieland, R.; Hampp, J. S.; Zhou, X. J.; Ji, M.; Kiselev, O.; Kinev, N.; Huang, Y.; Hao, L. Y.; Ishii, A.; Aksan, M. A.; Hatano, T.; Koshelets, V. P.; Wu, P. H.; Wang, H. B.; Koelle, D.; Kleiner, R.

    2017-03-01

    We report on doping and undoping experiments of terahertz (THz) emitting intrinsic Josephson junction stacks, where the change in charge carrier concentration is achieved by heavy current injection. The experiments were performed on stand-alone structures fabricated from a Bi2Sr2CaCu2O{}8+δ single crystal near optimal doping. The stacks contained about 930 intrinsic Josephson junctions. On purpose, the doping and undoping experiments were performed over only a modest range of charge carrier concentrations, changing the critical temperature of the stack by less than 1 K. We show that both undoping and doping is feasible also for the large intrinsic Josephson junction stacks used for THz generation. Even moderate changes in doping introduce large changes in the THz emission properties of the stacks. The highest emission power was achieved after doping a pristine sample.

  10. Simultaneous Infrared Dry-Blanching and Dehydration of apple slices Controlled by Intermittent Heating Mode

    Science.gov (United States)

    Infrared heating controlled by intermittent heating mode was found to be able to achieve simultaneous dry-blanching and dehydration of apple slices with a desirable quality. In order to better understand the performance of intermittent heating for simultaneous dry-blanching and dehydration (SIDBD),...

  11. Oscillation mode linewidths of main-sequence and subgiant stars observed by Kepler

    DEFF Research Database (Denmark)

    Appourchaux, T.; Benomar, O.; Gruberbauer, M.

    2012-01-01

    Solar-like oscillations have been observed by {{\\it Kepler}} and CoRoT in several solar-type stars. We study the variations of stellar p-mode linewidth as a function of effective temperature. Time series of 9 months of Kepler data have been used. The power spectra of 42 cool main-sequence stars...

  12. Mode-selective terahertz emission from rippled air irradiated by femtosecond laser pulses

    Science.gov (United States)

    Shin, Junghun; Zhidkov, Alexei; Jin, Zhan; Hosokai, Tomonao; Kodama, Ryosuke

    2014-04-01

    Terahertz (THz) emission from rippled air is studied in multidimensional particle-in-cell simulations that include optical field ionization. The ionization modulation in a plasma channel produced by a laser pulse propagating along a ripple and the pulse self-focusing result in THz mode selection with the generation of intense signals having quasi-monochromatic spectral distributions.

  13. Visual Working Memory in Deaf Children with Diverse Communication Modes: Improvement by Differential Outcomes

    Science.gov (United States)

    Lopez-Crespo, Ginesa; Daza, Maria Teresa; Mendez-Lopez, Magdalena

    2012-01-01

    Although visual functions have been proposed to be enhanced in deaf individuals, empirical studies have not yet established clear evidence on this issue. The present study aimed to determine whether deaf children with diverse communication modes had superior visual memory and whether their performance was improved by the use of differential…

  14. Structural Damage Localization by Outlier Analysis of Signal-processed Mode Shapes

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Damkilde, Lars

    2016-01-01

    analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically on the basis of a free-vibrating beam and experimentally in the context of a residential-sized wind turbine blade subjected...

  15. Evidence of DNA-Ligand Binding with Different Modes Studied by Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The binding behavior of several fluorescence dyes to calf thymus DNA has been studied by absorption, fluorescence and atomic force microscopy (AFM), which could provide direct evidence of formation modes and the corresponding nanostructural features of the ligand-DNA complexes.

  16. Evaluation of Lumicyano™ cyanoacrylate fuming process for the development of latent fingermarks on plastic carrier bags by means of a pseudo operational comparative trial.

    Science.gov (United States)

    Farrugia, Kevin J; Deacon, Paul; Fraser, Joanna

    2014-03-01

    There are a number of studies discussing recent developments of a one-step fluorescent cyanoacrylate process. This study is a pseudo operational trial to compare an example of a one-step fluorescent cyanoacrylate product, Lumicyano™, with the two recommended techniques for plastic carrier bags; cyanoacrylate fuming followed by basic yellow 40 (BY40) dyeing and powder suspensions. 100 plastic carrier bags were collected from the place of work and the items were treated as found without any additional fingermark deposition. The bags were split into three and after treatment with the three techniques a comparable number of fingermarks were detected by each technique (average of 300 fingermarks). The items treated with Lumicyano™ were sequentially processed with BY40 and an additional 43 new fingermarks were detected. Lumicyano™ appears to be a suitable technique for the development of fingermarks on plastic carrier bags and it can help save lab space and time as it does not require dyeing or drying procedures. Furthermore, contrary to other one-step cyanoacrylate products, existing cyanoacrylate cabinets do not require any modification for the treatment of articles with Lumicyano™. To date, there is little peer reviewed articles in the literature on trials related to Lumicyano™ and this study aims to contribute to fill this gap.

  17. CIE L*a*b*: comparison of digital images obtained photographically by manual and automatic modes

    Directory of Open Access Journals (Sweden)

    Fabiana Takatsui

    2012-12-01

    Full Text Available The aim of this study was to analyze the color alterations performed by the CIE L*a*b* system in the digital imaging of shade guide tabs, which were obtained photographically according to the automatic and manual modes. This study also sought to examine the observers' agreement in quantifying the coordinates. Four Vita Lumin Vaccum shade guide tabs were used: A3.5, B1, B3 and C4. An EOS Canon digital camera was used to record the digital images of the shade tabs, and the images were processed using Adobe Photoshop software. A total of 80 observations (five replicates of each shade according to two observers in two modes, specifically, automatic and manual were obtained, leading to color values of L*, a* and b*. The color difference (ΔE between the modes was calculated and classified as either clinically acceptable or unacceptable. The results indicated that there was agreement between the two observers in obtaining the L*, a* and b* values related to all guides. However, the B1, B3, and C4 shade tabs had ΔE values classified as clinically acceptable (ΔE = 0.44, ΔE = 2.04 and ΔE = 2.69, respectively. The A3.5 shade tab had a ΔE value classified as clinically unacceptable (ΔE = 4.17, as it presented higher values for luminosity in the automatic mode (L* = 54.0 than in the manual mode (L* = 50.6. It was concluded that the B1, B3 and C4 shade tabs can be used at any of the modes in digital camera (manual or automatic, which was a different finding from that observed for the A3.5 shade tab.

  18. Rayleigh-wave mode separation by high-resolution linear radon transform

    Science.gov (United States)

    Luo, Y.; Xia, J.; Miller, R.D.; Xu, Y.; Liu, J.; Liu, Q.

    2009-01-01

    Multichannel analysis of surface waves (MASW) method is an effective tool for obtaining vertical shear wave profiles from a single non-invasive measurement. One key step of the MASW method is generation of a dispersion image and extraction of a reliable dispersion curve from raw multichannel shot records. Because different Rayleigh-wave modes normally interfere with each other in the time and space domain, it is necessary to perform mode separation and reconstruction to increase the accuracy of phase velocities determined from a dispersion image. In this paper, we demonstrate the effectiveness of high-resolution linear Radon transform (LRT) as a means of separating and reconstructing multimode, dispersive Rayleigh-wave energy. We first introduce high-resolution LRT methods and Rayleigh-wave mode separation using high-resolution LRT. Next, we use synthetic data and a real-world example to demonstrate the effectiveness of Rayleigh-wave mode separation using high-resolution LRT. Our synthetic and real-world results demonstrate that (1) high-resolution LRT successfully separates and reconstructs multimode dispersive Rayleigh-wave energy with high resolution allowing the multimode energy to be more accurately determined. The horizontal resolution of the Rayleigh-wave method can be increased by extraction of dispersion curves from a pair of traces in the mode-separated shot gather and (2) multimode separation and reconstruction expand the usable frequency range of higher mode dispersive energy, which increases the depth of investigation and provides a means for accurately determining cut-off frequencies. ?? 2009 The Authors Journal compilation ?? 2009 RAS.

  19. Liver stiffness in the hepatitis B virus carrier: A non-invasive marker of liver disease influenced by the pattern of transaminases

    Institute of Scientific and Technical Information of China (English)

    Filippo Oliveri; Barbara Coco; Pietro Ciccorossi; Piero Colombatto; Veronica Romagnoli; Beatrice Cherubini; Ferruccio Bonino; Maurizia Rossana Brunetto

    2008-01-01

    AIM: To investigate the usefulness of transient elastography by Fibroscan (FS), a rapid non-invasive technique to evaluate liver fibrosis, in the management of chronic hepatitis B virus (HBV) carriers. METHODS: In 297 consecutive HBV carriers, we studied the correlation between liver stiffness (LS), stage of liver disease and other factors potentially influencing FS measurements. In 87 chronic hepatitis B (CHB) patients, we monitored the FS variations according to the spontaneous or treatment-induced variations of biochemical activity during follow-up. RESULTS: FS values were 12.3±3.3 kPa in acute hepatitis, 10.3±8.8 kPa in chronic hepatitis, 4.3 ±1.0 kPa in inactive carriers and 4.6±1.2 kPa in blood donors. We identified the cut-offs of 7.5 and 11.8 kPa for the diagnosis of fibrosis≥S3 and cirrhosis respectively, showing 93.9% and 86.5% sensitivity, 88.5% and 96.3% specificity, 76.7% and 86.7% positive predictive value (PPV), 97.3% and 96.3% negative predictive value (NPV) and 90.1% and 94.2% diagnostic accuracy. At multivariate analysis in 171 untreated carriers, fibrosis stage (t=13.187, P 10/18 vs≤ 10/18, P = 0.035) and All levels (t = 3.566, P = 0.001) were independently associated with LS in 83 untreated patients without cirrhosis and long-term biochemical remission (t = 4.662, P < 0.001) in 80 treated patients. During FS monitoring (mean follow-up 19.9±7.1 mo) FS values paralleled those of ALT in patients with hepatitis exacerbation (with 1.2 to 4.4-fold increases in CHB patients) and showed a progressive decrease during antiviral therapy. CONCLUSION: FS is a non-invasive tool to monitor liver disease in chronic HBV carriers, provided that the pattern of biochemical activity is taken into account. In the inactive carrier, it identifies non-HBV-related causes of liver damage and transient reactivations. In CHB patients, it may warrant a more appropriate timing of control liver biopsies.

  20. Liver stiffness in the hepatitis B virus carrier: A non-invasive marker of liver disease influenced by the pattern of transaminases

    Science.gov (United States)

    Oliveri, Filippo; Coco, Barbara; Ciccorossi, Pietro; Colombatto, Piero; Romagnoli, Veronica; Cherubini, Beatrice; Bonino, Ferruccio; Brunetto, Maurizia Rossana

    2008-01-01

    AIM: To investigate the usefulness of transient elastography by Fibroscan (FS), a rapid non-invasive technique to evaluate liver fibrosis, in the management of chronic hepatitis B virus (HBV) carriers. METHODS: In 297 consecutive HBV carriers, we studied the correlation between liver stiffness (LS), stage of liver disease and other factors potentially influencing FS measurements. In 87 chronic hepatitis B (CHB) patients, we monitored the FS variations according to the spontaneous or treatment-induced variations of biochemical activity during follow-up. RESULTS: FS values were 12.3 ± 3.3 kPa in acute hepatitis, 10.3 ± 8.8 kPa in chronic hepatitis, 4.3 ± 1.0 kPa in inactive carriers and 4.6 ± 1.2 kPa in blood donors. We identified the cut-offs of 7.5 and 11.8 kPa for the diagnosis of fibrosis ≥ S3 and cirrhosis respectively, showing 93.9% and 86.5% sensitivity, 88.5% and 96.3% specificity, 76.7% and 86.7% positive predictive value (PPV), 97.3% and 96.3% negative predictive value (NPV) and 90.1% and 94.2% diagnostic accuracy. At multivariate analysis in 171 untreated carriers, fibrosis stage (t = 13.187, P 10/18 vs ≤ 10/18, P = 0.035) and ALT levels (t = 3.566, P = 0.001) were independently associated with LS in 83 untreated patients without cirrhosis and long-term biochemical remission (t = 4.662, P < 0.001) in 80 treated patients. During FS monitoring (mean follow-up 19.9 ± 7.1 mo) FS values paralleled those of ALT in patients with hepatitis exacerbation (with 1.2 to 4.4-fold increases in CHB patients) and showed a progressive decrease during antiviral therapy. CONCLUSION: FS is a non-invasive tool to monitor liver disease in chronic HBV carriers, provided that the pattern of biochemical activity is taken into account. In the inactive carrier, it identifies non-HBV-related causes of liver damage and transient reactivations. In CHB patients, it may warrant a more appropriate timing of control liver biopsies. PMID:18985805

  1. A precise length etalon generator controlled by femtosecond mode-locked laser

    Science.gov (United States)

    Šmid, Radek; Čip, Ondřej; Lazar, Josef

    2007-09-01

    The progress in the field of optical frequency standards is oriented to femtosecond mode-locked lasers stabilized by technique of the optical frequency synthesis. Such a laser produces a supercontinuum light, which is composed of a cluster of coherent frequency components in certain interval of wavelengths. A value of the repetition rate of femtosecond pulses determines (in the frequency domain) spacing of these coherent components. If we control the mode-locked laser by means of i.e. atomic clocks we ensure frequency of these components very stable. With respect to definition of SI unit "one meter" on basis of speed of light the stabilized mode-locked laser can be used for implementation of this definition by non-traditional way. In the work we present our proposal of a system, which converts excellent frequency stability of components generated by the mode-locked laser to a net of discrete absolute lengths represented by a distance of two mirrors of an optical resonator. On basis of theory, the optical resonator with a cavity length has a periodic frequency spectrum Similarly the frequency of i-th comb component could be written as: f i = f ceo + i f rep, where f ceo is the comb offset frequency and f rep is the repetition rate. For the simplicity we presume the offset frequency f ceo equals to zero. If the supercontinuum beam of the mode-locked laser illuminates the resonator and at the same time the cavity length L is adjusted to length L p = c / (2 p f rep ) then both spectra fit. The symbol 'p' is an integer value. It produces intensity maximum in the output of the cavity, which is detected by a photodetector and locked in the servo-loop. For absolute discrete values of cavity lengths L p that well satisfy the condition above we obtain precise etalons of length.

  2. Locked mode unlocking by rotating resonant magnetic perturbations in J-TEXT tokamak

    Science.gov (United States)

    Jin, Hai; Hu, Qiming; Wang, Nengchao; Rao, Bo; Ding, Yonghua; Li, Da; Li, Mao; Xie, Shujia

    2015-10-01

    This study aimed to unlock the m/n = 2/1 locked mode (LM) performed in J-TEXT tokamak by using rotating resonant magnetic perturbations (RMPs), where m and n are the poloidal and toroidal mode numbers, respectively. In the experiments, to maintain the LM, mode locking occurs by using static RMPs generated by a set of saddle coils. After mode locking, another rotating RMP with frequency of several kilo-Hz is applied to drive the static LM to rotate. The unlocking of LM is realized by using rotating RMP with different frequency and amplitude. It is found that the unlocking process contains two stages, i.e. the oscillating stage and the unlocking stage. In the oscillating stage, the rotating RMP with amplitude that is not strong enough causes the LM to oscillate around its locked phase and produces magnetic fluctuation to behave as a standing wave-like structure in poloidal direction. When the amplitude of the rotating RMP is strong enough, it first causes the LM to oscillate and then transforms to mode unlocking quickly in less than 1 ms, namely the unlocking stage. Further analysis shows that the unlocking of LM is determined by the torque balance between the viscous torque and the electromagnetic torques exerted by both the static and the rotating RMP. In addition, the unlocking process is sensitive to both the amplitude and the frequency of the rotating RMP as well as the amplitude of static RMP. Nonlinear numerical modeling based on reduced MHD equations is also performed to understand the unlocking process, and numerical results qualitatively agree with the experimental ones.

  3. Ultrafast carriers dynamics in filled-skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Liang; Xu, Xianfan, E-mail: xxu@purdue.edu [School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Salvador, James R. [Chemical and Materials Systems Laboratory, GM Global R and D, Warren, Michigan 48090 (United States)

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  4. Ultrafast carriers dynamics in filled-skutterudites

    Science.gov (United States)

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-01

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4-0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  5. Carriers of the astronomical 2175 ? extinction feature

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J; Dai, Z; Ernie, R; Browning, N; Graham, G; Weber, P; Smith, J; Hutcheon, I; Ishii, H; Bajt, S; Floss, C; Stadermann, F

    2004-07-20

    The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere. The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.

  6. Theoretical analysis of the mode coupling induced by heat of large-pitch micro-structured fibers

    Institute of Scientific and Technical Information of China (English)

    张海涛; 陈丹; 郝杰; 闫平; 巩马理

    2015-01-01

    In this paper, a theoretical model to analyze the mode coupling induced by heat, when the fiber amplifier works at high power configuration, is proposed. The model mainly takes into consideration the mode field change due to the thermally induced refractive index change and the coupling between modes. Method to predict the largest average output power of fiber is also proposed according to the mode coupling theory. The largest average output power of a large pitch fiber with a core diameter of 190 µm and an available pulse energy of 100 mJ is predicted to be 540 W, which is the highest in large mode field fibers.

  7. Defect-free surface of quartz glass polished in elastic mode by chemical impact reaction

    Institute of Scientific and Technical Information of China (English)

    彭文强; 关朝亮; 李圣怡

    2014-01-01

    Removal of brittle materials in the brittle or ductile mode inevitably causes damaged or strained surface layers containing cracks, scratches or dislocations. Within elastic deformation, the arrangement of each atom can be recovered back to its original position without any defects introduced. Based on surface hydroxylation and chemisorption theory, material removal mechanism of quartz glass in the elastic mode is analyzed to obtain defect-free surface. Elastic contact condition between nanoparticle and quartz glass surface is confirmed from the Hertz contact theory model. Atoms on the quartz glass surface are removed by chemical bond generated by impact reaction in the elastic mode, so no defects are generated without mechanical process. Experiment was conducted on a numerically controlled system for nanoparticle jet polishing, and one flat quartz glass was polished in the elastic mode. Results show that scratches on the sample surface are completely removed away with no mechanical defects introduced, and micro-roughness (Ra) is decreased from 1.23 nm to 0.47 nm. Functional group Ce—O—Si on ceria nanoparticles after polishing was detected directly and indirectly by FTIR, XRD and XPS spectra analysis from which the chemical impact reaction is validated.

  8. Simple illustrations of range-dependence and 3-D effects by normal-mode sound propagation modelling

    CERN Document Server

    Ivansson, Sven

    2016-01-01

    As is well known, the sound-speed profile has significant effects on underwater acoustic sound propagation. These effects can be quantified by normal-mode models, for example. The basic case is a laterally homogeneous medium, for which the sound speed and the density depend on depth only and not on horizontal position. Effects of horizontal medium-parameter variation can be quantified by coupled-mode models, with coupling between mode expansions for laterally homogeneous parts of the medium. In the present paper, these effects are illustrated for media with a particularly simple horizontal parameter variation such that mode shapes do not vary with horizontal position. The modal wavenumbers depend on horizontal position, however. At a vertical interface between regions with laterally homogeneous medium parameters, each mode is reflected as well as transmitted. For the media considered, reflection and transmission coefficients can be computed separately for each mode without mode coupling, and this is done recu...

  9. Imparting carrier status results detected by universal newborn screening for sickle cell and cystic fibrosis in England: a qualitative study of current practice and policy challenges

    Directory of Open Access Journals (Sweden)

    Ulph Fiona

    2007-12-01

    Full Text Available Abstract Background Universal newborn screening for early detection of children affected by sickle cell disorders and cystic fibrosis is currently being implemented across England. Parents of infants identified as carriers of these disorders must also be informed of their baby's result. However there is a lack of evidence for most effective practice internationally when doing so. This study describes current or proposed models for imparting this information in practice and explores associated challenges for policy. Methods Thematic analysis of semi-structured interviews with Child Health Coordinators from all English Health Regions. Results Diverse methods for imparting carrier results, both within and between regions, and within and between conditions, were being implemented or planned. Models ranged from result by letter to in-person communication during a home visit. Non-specialists were considered the best placed professionals to give results and a similar approach for both conditions was emphasised. While national guidance has influenced choice of models, other factors contributed such as existing service structures and lack of funding. Challenges included uncertainty about guidance specifying face to face notification; how best to balance allaying parental anxiety by using familiar non-specialist health professionals with concerns about practitioner competence; and extent of information parents should be given. Inadequate consideration of resource and service workload was seen as the main policy obstacle. Clarification of existing guidance; more specific protocols to ensure consistent countrywide practice; integration of the two programmes; and 'normalising' carrier status were suggested as improvements. Conclusion Differing models for communicating carrier results raise concerns about equity and clinical governance. However, this variation provides opportunity for evaluation. Timely and more detailed guidance on protocols with

  10. Avoidance of tearing mode locking with electro-magnetic torque introduced by feedback-based mode rotation control in DIII-D and RFX-mod

    Science.gov (United States)

    Okabayashi, M.; Zanca, P.; Strait, E. J.; Garofalo, A. M.; Hanson, J. M.; In, Y.; La Haye, R. J.; Marrelli, L.; Martin, P.; Paccagnella, R.; Paz-Soldan, C.; Piovesan, P.; Piron, C.; Piron, L.; Shiraki, D.; Volpe, F. A.; DIII-D, The; RFX-mod Teams

    2017-01-01

    Disruptions caused by tearing modes (TMs) are considered to be one of the most critical roadblocks to achieving reliable, steady-state operation of tokamak fusion reactors. Here we have demonstrated a promising scheme to avoid mode locking by utilizing the electro-magnetic (EM) torque produced with 3D coils that are available in many tokamaks. In this scheme, the EM torque is delivered to the modes by a toroidal phase shift between the externally applied field and the excited TM fields, compensating for the mode momentum loss through the interaction with the resistive wall and uncorrected error fields. Fine control of torque balance is provided by a feedback scheme. We have explored this approach in two widely different devices and plasma conditions: DIII-D and RFX-mod operated in tokamak mode. In DIII-D, the plasma target was high β N in a non-circular divertor tokamak. Here β N is defined as β N  =  β/(I p /aB t) (%Tm/MA), where β, I p, a, B t are the total stored plasma pressure normalized by the magnetic pressure, plasma current, plasma minor radius and toroidal magnetic field at the plasma center, respectively. The RFX-mod plasma was ohmically-heated with ultra-low safety factor in a circular limiter discharge with active feedback coils outside the thick resistive shell. The DIII-D and RFX-mod experiments showed remarkable consistency with theoretical predictions of torque balance. The application to ignition-oriented devices such as the International Thermonuclear Experimental Reactor (ITER) would expand the horizon of its operational regime. The internal 3D coil set currently under consideration for edge localized mode suppression in ITER would be well suited for this purpose.

  11. Amplification of pico-scale DNA mediated by bacterial carrier DNA for small-cell-number transcription factor ChIP-seq

    DEFF Research Database (Denmark)

    Jakobsen, Janus S; Bagger, Frederik O; Hasemann, Marie S;

    2015-01-01

    BACKGROUND: Chromatin-Immunoprecipitation coupled with deep sequencing (ChIP-seq) is used to map transcription factor occupancy and generate epigenetic profiles genome-wide. The requirement of nano-scale ChIP DNA for generation of sequencing libraries has impeded ChIP-seq on in vivo tissues of low...... transcription factor (CEBPA) and histone mark (H3K4me3) ChIP. We further demonstrate that genomic profiles are highly resilient to changes in carrier DNA to ChIP DNA ratios. CONCLUSIONS: This represents a significant advance compared to existing technologies, which involve either complex steps of pre...... cell numbers. RESULTS: We describe a robust, simple and scalable methodology for ChIP-seq of low-abundant cell populations, verified down to 10,000 cells. By employing non-mammalian genome mapping bacterial carrier DNA during amplification, we reliably amplify down to 50 pg of ChIP DNA from...

  12. Tuning the carrier density of LaAlO3/SrTiO3 interfaces by capping La1-xSrxMnO3

    Science.gov (United States)

    Shi, Y. J.; Wang, S.; Zhou, Y.; Ding, H. F.; Wu, D.

    2013-02-01

    We present a systematical study on the electronic transport properties of the insulating LaAlO3 (3 unit cells)/SrTiO3 interfaces capping with thin layers of La1-xSrxMnO3, whose formal polarization is continually tuned by Sr doping. When the Sr doping is lower than 2/3, the LaAlO3/SrTiO3 interfaces show metallic behaviors. The carrier mobility is almost independent on the Sr doping for metallic interface, indicating that the capping layer does not change the density of the oxygen vacancies and the interface intermixing. However, the sheet carrier densities monotonically decrease as increasing Sr doping, which is ascribed to the decrease of the La1-xSrxMnO3 formal polarization. These results strongly support the intrinsic mechanism of the polar catastrophe model and provide a new approach to tailor the interface states of complex oxide heterostructures.

  13. The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method.

    Science.gov (United States)

    Wada, Takao; Ueda, Noriaki

    2013-04-21

    The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature.

  14. Carrier density driven lasing dynamics in ZnO nanowires

    CERN Document Server

    Wille, Marcel; Michalsky, Tom; Röder, Robert; Ronning, Carsten; Schmidt-Grund, Rüdiger; Grundmann, Marius

    2016-01-01

    We report on the temporal lasing dynamics of high quality ZnO nanowires using time-resolved micro-photoluminescence technique. The temperature dependence of the lasing characteristics and of the corresponding decay constants demonstrate the formation of an electron-hole plasma to be the underlying gain mechanism in the considered temperature range from 10 K to 300 K. We found that the temperature dependent emission onset-time ($t_{\\text{on}}$) strongly depends on the excitation power and becomes smallest in the lasing regime, with values below 5 ps. Furthermore, the observed red shift of the dominating lasing modes in time is qualitatively discussed in terms of the carrier density induced change of the refractive index dispersion after the excitation laser pulse. This theory is supported by extending an existing model for the calculation of the carrier density dependent complex refractive index for different temperatures. This model coincides with the experimental observations and reliably describes the evolu...

  15. Shear flow generation by Reynolds stress and suppression of resistive g-modes

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, H. [National Inst. for Fusion Science, Nagoya (Japan); Horton, W. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

    1993-08-01

    Suppression of resistive g-mode turbulence by background shear flow generated from a small external flow source and amplified by the fluctuation-induced Reynolds stress is demonstrated and analyzed. The model leads to a paradigm for the low-to-high (L-H) confinement mode transition. To demonstrate the L-H transition model, single-helicity nonlinear fluid simulations using the vorticity equation for the electrostatic potential, the pressure fluctuation equation and the background poloidal flow equation are used in the sheared slab configuration. The relative efficiency of the external flow and the Reynolds stress for producing shear flow depends on the poloidal flow damping parameter {nu} which is given by neoclassical theory. For large {nu}, the external flow is a dominant contribution to the total background poloidal shear flow and its strength predicted by the neoclassical theory is not enough to suppress the turbulence significantly. In contrast, for small {nu}, we show that the fluctuations drive a Reynolds stress that becomes large and suddenly, at some critical point in time, shear flow much larger than the external flow is generated and leads to an abrupt, order unity reduction of the turbulent transport just like that of the L-H transition in tokamak experiments. It is also found that, even in the case of no external flow, the shear flow generation due to the Reynolds stress occurs through the nonlinear interaction of the resistive g-modes and reduces the transport. To supplement the numerical solutions we derive the Landau equation for the mode amplitude of the resistive g-mode taking into account the fluctuation-induced shear flow and analyze the opposite action of the Reynolds stress in the resistive g turbulence compared with the classical shear flow Kelvin-Helmholtz (K-H) driven turbulence.

  16. Anomalous ion thermal transport in hot ion plasmas by the ion temperature gradient mode

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.Y.; Horton, W. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies); Coppi, B. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Research Lab. of Electronics)

    1992-01-01

    Experiments show that the observed radial profiles of the ion thermal conductivity {chi}{sub i} have the opposite shapes with those obtained from the ion temperature gradient mode ({eta}{sub i} mode) turbulence model by the traditional mixing length estimate. In this work, this radial profile problem is reconsidered with an electromagnetic study of the linear stability of the toroidal {eta}{sub i} mode and a new rule for choosing the mixing length. It is first shown that the electromagnetic effect gives a significant stabilizing effect on the toroidal {eta}{sub i} mode, and that the observed reduction of {chi}{sub i}(r) in the core region can be explained by this electromagnetic effect. Secondly, in view of earlier numerical simulations showing the transfer of fluctuation energy to larger scales that those for the fastest growth rate, as well as fluctuation measurements indicating longer radial correlation lengths, a new mixing length formula is proposed to explain the radial increase of the {chi}{sub i}. It is shown the new formula fits well the observed {chi}{sub i}(r) profiles in two TFTR supershot discharges and also gives the scaling law in the current and the magnetic field which agrees better with experiment than the conventional formula.

  17. Anomalous ion thermal transport in hot ion plasmas by the ion temperature gradient mode

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.Y.; Horton, W. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Coppi, B. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Research Lab. of Electronics

    1992-08-01

    Experiments show that the observed radial profiles of the ion thermal conductivity {chi}{sub i} have the opposite shapes with those obtained from the ion temperature gradient mode ({eta}{sub i} mode) turbulence model by the traditional mixing length estimate. In this work, this radial profile problem is reconsidered with an electromagnetic study of the linear stability of the toroidal {eta}{sub i} mode and a new rule for choosing the mixing length. It is first shown that the electromagnetic effect gives a significant stabilizing effect on the toroidal {eta}{sub i} mode, and that the observed reduction of {chi}{sub i}(r) in the core region can be explained by this electromagnetic effect. Secondly, in view of earlier numerical simulations showing the transfer of fluctuation energy to larger scales that those for the fastest growth rate, as well as fluctuation measurements indicating longer radial correlation lengths, a new mixing length formula is proposed to explain the radial increase of the {chi}{sub i}. It is shown the new formula fits well the observed {chi}{sub i}(r) profiles in two TFTR supershot discharges and also gives the scaling law in the current and the magnetic field which agrees better with experiment than the conventional formula.

  18. Model-Free Adaptive Fuzzy Sliding Mode Controller Optimized by Particle Swarm for Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Amin Jalali

    2013-05-01

    Full Text Available The main purpose of this paper is to design a suitable control scheme that confronts the uncertainties in a robot. Sliding mode controller (SMC is one of the most important and powerful nonlinear robust controllers which has been applied to many non-linear systems. However, this controller has some intrinsic drawbacks, namely, the chattering phenomenon, equivalent dynamic formulation, and sensitivity to the noise. This paper focuses on applying artificial intelligence integrated with the sliding mode control theory. Proposed adaptive fuzzy sliding mode controller optimized by Particle swarm algorithm (AFSMC-PSO is a Mamdani’s error based fuzzy logic controller (FLS with 7 rules integrated with sliding mode framework to provide the adaptation in order to eliminate the high frequency oscillation (chattering and adjust the linear sliding surface slope in presence of many different disturbances and the best coefficients for the sliding surface were found by offline tuning Particle Swarm Optimization (PSO. Utilizing another fuzzy logic controller as an impressive manner to replace it with the equivalent dynamic part is the main goal to make the model free controller which compensate the unknown system dynamics parameters and obtain the desired control performance without exact information about the mathematical formulation of model.

  19. A new instability index for unstable mode selection in squeal prediction by complex eigenvalue analysis

    Science.gov (United States)

    Brunetti, J.; Massi, F.; D`Ambrogio, W.; Berthier, Y.

    2016-09-01

    During these last decades the modal instability of systems, generated by frictional contact forces, has been the subject of a huge amount of works in friction induced vibration literature. Linear and nonlinear numerical analyses have been largely investigated to predict and reproduce squeal vibrations. While nonlinear transient analysis needs large computational efforts, results of Complex Eigenvalue Analysis (CEA) suffer from an over-prediction issue and it is not able to predict correctly the mode that will become effectively unstable in case of several unstable eigenvalues. Because the CEA has been adopted as an efficient tool for brake design, a more reliable index is here proposed, from the CEA outputs and energetic considerations, to identify the mode that will become effectively unstable. A modular lumped model is developed to reproduce friction induced vibrations. The use of the eigenvalue real part, as discriminant of the system instability, is here combined with information coming from the eigenvectors, projected on the equilibrium position, to account for the energy flows involved in the squeal phenomena. This approach allows to define a Modal Absorption Index (MAI). The MAI allows for comparing unstable modes of the same system and is applied in this paper to predict, by CEA outputs, the unstable mode that will effectively result in squeal vibrations.

  20. Pneumococcal DNA is not detectable in the blood of healthy carrier children by real-time PCR targeting the lytA gene.

    Science.gov (United States)

    Azzari, Chiara; Cortimiglia, Martina; Moriondo, Maria; Canessa, Clementina; Lippi, Francesca; Ghiori, Federica; Becciolini, Laura; de Martino, Maurizio; Resti, Massimo

    2011-06-01

    The diagnosis of invasive pneumococcal disease (IPD) is currently based on culture methods, which lack sensitivity, especially after antibiotic therapy. Molecular methods have improved sensitivity and do not require viable bacteria; however, their use is complicated by reports of low specificity with some assays. The present study investigated the specificity of a real-time PCR targeting lytA for the detection of IPD. A group of 147 healthy children, aged 6 months to 16 years (mean 6.4 years, median 4.9 years, interquartile range 6.4 years), who were in hospital for routine examinations, were tested for pneumococcal carrier status and for the presence of detectable pneumococcal DNA in their blood by real-time PCR targeting the pneumococcal lytA gene. In addition, 35 culture-positive biological samples were analysed. Urine was examined for the presence of pneumococcal DNA and C-polysaccharide antigen. Carriage was detected in 77 of the 147 subjects (52.4 %); however, regardless of carrier status, none of the subjects had a positive result from blood. Analysis of the culture-positive biological samples yielded positive results in 100 % (15/15) of cerebrospinal fluid samples and 95 % (19/20) of blood samples. All urine samples from healthy carriers were negative for DNA, whilst antigenuria was detected in 44/77 carriers (57.1 %). In conclusion, real-time PCR is both sensitive and specific and can be a useful tool in the routine diagnosis of IPD. Its sensitivity, which surpasses that of other methods for this purpose, does not come at the cost of reduced specificity.

  1. Efficient conversion of high concentration of glycerol to Monacolin K by solid-state fermentation of Monascus purpureus using bagasse as carrier.

    Science.gov (United States)

    Lu, Li-Ping; Zhang, Bo-Bo; Xu, Gan-Rong

    2013-03-01

    High concentration of glycerol was used as the sole carbon source for efficient production of Monacolin K (MK) by solid-state fermentation (SSF) of Monascus purpureus 9901 using agricultural residue (bagasse), as an inert carrier. A comparative study showed that MK production in SSF was about 5.5 times higher than that of submerged fermentation when 26 % of glycerol was used, which may be due to the formation of glycerol concentration gradients in the inert carrier and less catabolite repression in SSF. For enhancement of MK yield in SSF, the effects of different influential variables, such as glycerol concentration, nitrogen source and its concentration, initial moisture content, inoculum size and particle size of bagasse, were systematically examined. All the factors mentioned above had an effect on the MK production in SSF to some extent. The maximal yield of MK (12.9 mg/g) was achieved with 26 % glycerol, 5 % soybean meal, 51 % initial moisture content, 20 % inoculum size and 1 mm particle size of bagasse. The results in this study may expand our understanding on the application of SSF using agricultural residue as carrier for production of useful microbial metabolites, especially the efficient conversion of high concentration of glycerol to MK by Monascus purpureus.

  2. Impact of carriers in oral absorption

    DEFF Research Database (Denmark)

    Gram, Luise Kvisgaard; Rist, Gerda Marie; Lennernäs, Hans

    2009-01-01

    (APP) was not described by carrier kinetics. However, glipizide is affecting exsorption for ES, due to interactions on basolateral carrier. The study confirms that estrone-3-sulfate can be used to characterize anionic carrier kinetics. Furthermore it is suggested that estrone-3-sulfate may be used to identify compounds......Carriers may mediate the permeation across enterocytes for drug substances being organic anions. Carrier mediated permeation for the organic anions estrone-3-sulfate (ES) and glipizide across Caco-2 cells were investigated kinetically, and interactions on involved carriers evaluated. Initial...... uptakes (P(UP)) at apical and basolateral membranes, apparent permeabilities (P(APP)) and corresponding intracellular end-point accumulations (P(EPA)) of radioactive labeled compounds were studied. Possible effects of other anionic compounds were investigated. Apical P(UP) and absorptive P(APP) for ES...

  3. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  4. Perimeter Governed Minority Carrier Lifetimes in 4H-SiC p+n Diodes Measured by Reverse Recovery Switching Transient Analysis

    Science.gov (United States)

    Neudeck, Philip G.

    1998-01-01

    Minority carrier lifetimes in epitaxial 4H-SiC p-n junction diodes were measured via an analysis of reverse recovery switching characteristics. Behavior of reverse recovery storage time (t(sub s)) as a function of initial ON-state forward current (I(sub f)) and OFF-state reverse current (I(sub R)) followed well-documented trends which have been observed for decades in silicon p-n rectifiers. Average minority carrier (hole) lifetimes (tau(sub p)) calculated from plots of t(sub s) vs I(sub R)/I(sub F) strongly decreased with decreasing device area. Bulk and perimeter components of average hole lifetimes were separated by plotting tau(sub p) as a function of device perimeter-to-area ratio (P/A). This plot reveals that perimeter recombination is dominant in these devices, whose areas are all less than 1 square mm. The bulk minority carrier (hole) lifetime extracted from the 1/Tau(sub p) vs P/A plot is approximately 0.7 microns, well above the 60 ns to 300 ns average lifetimes obtained when perimeter recombination effects are ignored in the analysis. Given the fact that there has been little previous investigation of bipolar diode and transistor performance as a function of perimeter-to-area ratio, this work raises the possibility that perimeter recombination may be partly responsible for poor effective minority carrier lifetimes and limited performance obtained in many previous SiC bipolar junction devices.

  5. Application of Carrier Aggregation in TD-LTE Dual-Mode Evolution Station%T D-LT E双模演进基站载波聚合的应用

    Institute of Scientific and Technical Information of China (English)

    朱智俊; 岑曙炜; 曹晶; 张真桢

    2014-01-01

    In the evolution of LTE to LTE-Advanced system, the demand of wider spectrum will become one of the most important factors affecting the evolution. The problems about how to effectively use the scattered spectrum in the frequency domain and to achieve higher system bandwidth through resources integration must be addressed. Based on this, 3GPP proposes carrier aggregation technology. First the business process design of carrier aggregation(CA) in mobile communication network is presented. And then the DT test results, UE peak test results and high-rate link test results of CA are discussed and analyzed. Finally, the problems of carrier aggregation are pointed out.%在LTE到LTE-Advanced系统的演进过程中,更宽频谱的需求将会成为影响演进的最重要因素之一,如何有效利用频域上分散的频谱资源,通过资源整合以获得更高的系统带宽是必须解决的问题,为此3GPP提出了载波聚合技术。首先给出了载波聚合(CA)在移动通信网中的业务流程设计;然后讨论和分析了CA的拉网测试结果、UE峰值测试结果和高速率路段测试结果;最后指出了载波聚合待解决的问题。

  6. Regional brain metabolite abnormalities in inherited prion disease and asymptomatic gene carriers demonstrated in vivo by quantitative proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, A.D.; Cordery, R.J.; Godbolt, A.; Rossor, M.N. [University College London, Dementia Research Group, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom); Imperial College of Science, Technology and Medicine, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, London (United Kingdom); MacManus, D.G. [University College London, NMR Research Unit, Department of Clinical Neurology, Institute of Neurology, London (United Kingdom); Collinge, J. [University College London, MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom)

    2006-06-15

    Inherited prion diseases are caused by mutations in the gene which codes for prion protein (PrP), leading to proliferation of abnormal PrP isomers in the brain and neurodegeneration; they include Gerstmann-Straeussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). We studied two patients with symptomatic inherited prion disease (P102L) and two pre-symptomatic P102L gene carriers using quantitative magnetic resonance spectroscopy (MRS). Short echo time spectra were acquired from the thalamus, caudate region and frontal white matter, metabolite levels and ratios were measured and z-scores calculated for individual patients relative to age-matched normal controls. MRS data were compared with structural magnetic resonance imaging. One fCJD case had generalised atrophy and showed increased levels of myo-inositol (MI) in the thalamus (z=3.7). The other had decreased levels of N-acetylaspartate (z=4) and diffuse signal abnormality in the frontal white matter. Both asymptomatic gene carriers had normal imaging, but increased frontal white matter MI (z=4.3, 4.1), and one also had increased MI in the caudate (z=5.3). Isolated MI abnormalities in asymptomatic gene carriers are a novel finding and may reflect early glial proliferation, prior to significant neuronal damage. MRS provides potential non-invasive surrogate markers of early disease and progression in inherited prion disease. (orig.)

  7. Dielectric functions and carrier concentrations of Hg{sub 1−x}Cd{sub x}Se films determined by spectroscopic ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A. J.; Peiris, F. C., E-mail: peirisf@kenyon.edu [Department of Physics, Kenyon College, Gambier, Ohio 43022 (United States); Brill, G.; Doyle, K. [U.S. Army Research Laboratory, Adelphi, Maryland 20783-1197 (United States); Myers, T. H. [Department of Physics, Texas State University, San Marcos, Texas 78666 (United States)

    2015-08-17

    Spectroscopic ellipsometry, ranging from 35 meV to 6 eV, was used to determine the dielectric functions of a series of molecular beam epitaxy-grown Hg{sub 1−x}Cd{sub x}Se thin films deposited on both ZnTe/Si(112) and GaSb(112) substrates. The fundamental band gap as well as two higher-order electronic transitions blue-shift with increasing Cd composition in Hg{sub 1−x}Cd{sub x}Se, as expected. Representing the free carrier absorption with a Drude oscillator, we found that the effective masses of Hg{sub 1−x}Cd{sub x}Se (grown on ZnTe/Si) vary between 0.028 and 0.050 times the free electron mass, calculated using the values of carrier concentration and the mobility obtained through Hall measurements. Using these effective masses, we determined the carrier concentrations of Hg{sub 1−x}Cd{sub x}Se samples grown on GaSb, which is of significance as films grown on such doped-substrates posit ambiguous results when measured by conventional Hall experiments. These models can serve as a basis for monitoring Cd-composition during sample growth through in-situ spectroscopic ellipsometry.

  8. Use of hydrogen as a carrier gas for the analysis of steroids with anabolic activity by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Muñoz-Guerra, J A; Prado, P; García-Tenorio, S Vargas

    2011-10-14

    Due to the impact in the media and the requirements of sensitivity and robustness, the detection of the misuse of forbidden substances in sports is a really challenging area for analytical chemistry, where any study focused on enhancing the performance of the analytical methods will be of great interest. The aim of the present study was to evaluate the usefulness of using hydrogen instead of helium as a carrier gas for the analysis of anabolic steroids by gas chromatography-mass spectrometry with electron ionization. There are several drawbacks related with the use of helium as a carrier gas: it is expensive, is a non-renewable resource, and has limited availability in many parts of the world. In contrast, hydrogen is readily available using a hydrogen generator or high-pressure bottled gas, and allows a faster analysis without loss of efficiency; nevertheless it should not be forgotten that due to its explosiveness hydrogen must be handled with caution. Throughout the study the impact of the change of the carrier gas will be evaluated in terms of: performance of the chromatographic system, saving of time and money, impact on the high vacuum in the analyzer, changes in the fragmentation behaviour of the analytes, and finally consequences for the limits of detection achieved with the method.

  9. Free-charge carrier parameters of n-type, p-type and compensated InN:Mg determined by Infrared Spectroscopic Ellipsometry

    CERN Document Server

    Schöche, S; Darakchieva, V; Wang, X; Yoshikawa, A; Wang, K; Araki, T; Nanishi, Y; Schubert, M

    2013-01-01

    Infrared spectroscopic ellipsometry is applied to investigate the free-charge carrier properties of Mg-doped InN films. Two representative sets of In-polar InN grown by molecular beam epitaxy with Mg concentrations ranging from $1.2\\times10^{17}$ cm$^{-3}$ to $8\\times10^{20}$ cm$^{-3}$ are compared. P-type conductivity is indicated for the Mg concentration range of $1\\times10^{18}$ cm$^{-3}$ to $9\\times10^{19}$ cm$^{-3}$ from a systematic investigation of the longitudinal optical phonon plasmon broadening and the mobility parameter in dependence of the Mg concentration. A parameterized model that accounts for the phonon-plasmon coupling is applied to determine the free-charge carrier concentration and mobility parameters in the doped bulk InN layer as well as the GaN template and undoped InN buffer layer for each sample. The free-charge carrier properties in the second sample set are consistent with the results determined in a comprehensive analysis of the first sample set reported earlier [Sch\\"oche et al., ...

  10. Efficient charge-carrier extraction from Ag2S quantum dots prepared by the SILAR method for utilization of multiple exciton generation

    Science.gov (United States)

    Zhang, Xiaoliang; Liu, Jianhua; Johansson, Erik M. J.

    2015-01-01

    The utilization of electron-hole pairs (EHPs) generated from multiple excitons in quantum dots (QDs) is of great interest toward efficient photovoltaic devices and other optoelectronic devices; however, extraction of charge carriers remains difficult. Herein, we extract photocharges from Ag2S QDs and investigate the dependence of the electric field on the extraction of charges from multiple exciton generation (MEG). Low toxic Ag2S QDs are directly grown on TiO2 mesoporous substrates by employing the successive ionic layer adsorption and reaction (SILAR) method. The contact between QDs is important for the initial charge separation after MEG and for the carrier transport, and the space between neighbor QDs decreases with more SILAR cycles, resulting in better charge extraction. At the optimal electric field for extraction of photocharges, the results suggest that the threshold energy (hνth) for MEG is 2.41Eg. The results reveal that Ag2S QD is a promising material for efficient extraction of charges from MEG and that QDs prepared by SILAR have an advantageous electrical contact facilitating charge separation and extraction.The utilization of electron-hole pairs (EHPs) generated from multiple excitons in quantum dots (QDs) is of great interest toward efficient photovoltaic devices and other optoelectronic devices; however, extraction of charge carriers remains difficult. Herein, we extract photocharges from Ag2S QDs and investigate the dependence of the electric field on the extraction of charges from multiple exciton generation (MEG). Low toxic Ag2S QDs are directly grown on TiO2 mesoporous substrates by employing the successive ionic layer adsorption and reaction (SILAR) method. The contact between QDs is important for the initial charge separation after MEG and for the carrier transport, and the space between neighbor QDs decreases with more SILAR cycles, resulting in better charge extraction. At the optimal electric field for extraction of photocharges, the

  11. Diagnosis of Fault Modes Masked by Control Loops with an Application to Autonomous Hovercraft Systems

    Directory of Open Access Journals (Sweden)

    Ioannis A. Raptis

    2013-01-01

    Full Text Available This paper introduces a methodology for the design, testing and assessment of incipient failure detection techniques for failing components/systems of an autonomous vehicle masked or hidden by feedback control loops. It is recognized that the optimum operation of critical assets (aircraft, autonomous systems, etc. may be compromised by feedback control loops by masking severe fault modes while compensating for typical disturbances. Detrimental consequences of such occurrences include the inability to detect expeditiously and accurately incipient failures, loss of control and inefficient operation of assets in the form of fuel overconsumption and adverse environmental impact. We pursue a systems engineering process to design, construct and test an autonomous hovercraft instrumented appropriately for improved autonomy. Hidden fault modes are detected with performance guarantees by invoking a Bayesian estimation approach called particle filtering. Simulation and experimental studies are employed to demonstrate the efficacy of the proposed methods.

  12. Dynamic substructuring by the boundary flexibility vector method of component mode synthesis. Ph.D. Thesis

    Science.gov (United States)

    Abdallah, Ayman Ahmed

    1990-01-01

    Component mode synthesis (CMS) is a method of dynamic analysis, for structures having a large number of degrees of freedom (DOF). These structures often required lengthy computer CPU time and large computer memory resources, if solved directly by the finite-element method (FEM). In CMS, the structure is divided into independent components in which the DOF are defined by a set of generalized coordinates defined by displacement shapes. The number of the generalized coordinates are much less than the original number of physical DOF, in the component. The displacement shapes are used to transform the component property matrices and any applied external loads, to a reduced system of coordinates. Reduced system property matrices are assembled, and any type of dynamic analysis is carried out in the reduced coordinate system. Any obtained results are back transformed to the original component coordinate systems. In all conventional methods of CMS, the mode shapes used for components are dynamic mode shapes, supplemented by static deflected shapes. Historically, all the dynamic mode shapes used in conventional CMS are the natural modes (eigenvectors) of components. A new method of CMS, namely the boundary flexibility vector method of CMS, is presented. The method provides for the incorporation of a set of static Ritz vectors, referred to as boundary flexibility vectors, as a replacement and/or supplement to conventional eigenvectors, as displacement shapes for components. The generation of these vectors does not require the solution of a costly eigenvalue problem, as in the case of natural modes in conventional CMS, and hence a substantial saving in CPU time can be achieved. The boundary flexibility vectors are generated from flexibility (or stiffness) properties of components. The formulation presented is for both free and fixed-interface components, and for both the free and forced vibration problems. Free and forced vibration numerical examples are presented to verify

  13. Evaluation of travelling vortex speed by means of vortex tracking and dynamic mode decomposition

    Science.gov (United States)

    Hyhlík, Tomáš

    2016-06-01

    The article deals with the analysis of unsteady periodic flow field related to synthetic jet creation. The analyses are based on the data obtained using ANSYS Fluent solver. Numerical results are validated by hot wire anemometry data measured along the jet centerline. The speed of travelling vortex ring is evaluated by using vortex tracking method and by using dynamic mode decomposition method. Vortex identification is based on residual vorticity which allows identifying regions in the flow field where fluid particles perform the rotational motion. The regime of the synthetic jet with Re = 329 and S = 19.7 is chosen. Both the vortex tracking and the dynamic mode decomposition based vortex speed evaluation indicate an increase in the vortex speed close to the orifice and then decrease with maximum reaching almost one and half of orifice centerline velocity. The article contains extended version the article presented at the conference AEaNMiFMaE 2016.

  14. Color digital holography using speckle illumination by means of a multi-mode fiber

    Science.gov (United States)

    Funamizu, Hideki; Shimoma, Shohei; Aizu, Yoshihisa

    2014-02-01

    We present color digital holography using speckle illumination by means of a multi-mode fiber. In this technique, speckle fields emitted from the fiber are used as both a reference wave and a wavefront illuminating an object. For three wavelengths, the interference patterns of two coherent waves are recorded as digital holograms on a CCD camera. A speckle method is used for suppressing DC terms and reducing a twin image in an in-line color digital holography. The speckle fields are changed by vibrating the multi-mode fiber using a vibrator, and a number of holograms are acquired to average reconstructed images. The dependence of the averaged number of holograms on color quality of reconstructed images is evaluated by chromaticity coordinates and color differences in colorimetry.

  15. High-Q band edge mode of plasmonic crystals studied by cathodoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Masahiro; Yamamoto, Naoki, E-mail: nyamamot@phys.titech.ac.jp [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)

    2014-02-24

    We have investigated the quality factor (Q-factor) of the band edge modes in the plasmonic crystal by a cathodoluminescence technique. We have found that the Q-factor at the Γ point depends on the terrace width (D)/period (P) ratio of the plasmonic crystal. The finite-difference time-domain methods predict that the band edge mode at D/P = 3/4 has a high-Q-factor (Q ∼ 250 by Palik's permittivity data and Q ∼ 530 by Johnson and Christy's data). The beam-scan spectral images allowed us to visualize the standing surface plasmon polariton waves at the band edge energies, and a high-Q-factor of ∼200 was observed at D/P ∼ 3/4.

  16. High-Q band edge mode of plasmonic crystals studied by cathodoluminescence

    Science.gov (United States)

    Honda, Masahiro; Yamamoto, Naoki

    2014-02-01

    We have investigated the quality factor (Q-factor) of the band edge modes in the plasmonic crystal by a cathodoluminescence technique. We have found that the Q-factor at the Γ point depends on the terrace width (D)/period (P) ratio of the plasmonic crystal. The finite-difference time-domain methods predict that the band edge mode at D/P = 3/4 has a high-Q-factor (Q ˜ 250 by Palik's permittivity data and Q ˜ 530 by Johnson and Christy's data). The beam-scan spectral images allowed us to visualize the standing surface plasmon polariton waves at the band edge energies, and a high-Q-factor of ˜200 was observed at D/P ˜ 3/4.

  17. Geodesic mode instability driven by electron and ion fluxes in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Elfimov, A. G., E-mail: elfimov@if.usp.br; Camilo de Souza, F.; Galvão, R. M. O. [Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil)

    2015-11-15

    The effect of the parallel electron current and plasma flux on Geodesic Acoustic Modes (GAM) in a tokamak is analyzed by kinetic theory taking into the account the ion Landau damping and diamagnetic drifts. It is shown that the electron current and plasma flow, modeled by shifted Maxwell distributions of electrons and ions, may overcome the ion Landau damping generating the GAM instability when the parallel electron current velocity is larger than the effective parallel GAM phase velocity of sidebands, Rqω. The instability is driven by the electron current and the parallel ion flux cross term. Possible applications to tokamak experiments are discussed. The existence of the geodesic ion sound mode due to plasma flow is shown.

  18. Enhancing dominant modes in nonstationary time series by means of the symbolic resonance analysis

    Science.gov (United States)

    beim Graben, Peter; Drenhaus, Heiner; Brehm, Eva; Rhode, Bela; Saddy, Douglas; Frisch, Stefan

    2007-12-01

    We present the symbolic resonance analysis (SRA) as a viable method for addressing the problem of enhancing a weakly dominant mode in a mixture of impulse responses obtained from a nonlinear dynamical system. We demonstrate this using results from a numerical simulation with Duffing oscillators in different domains of their parameter space, and by analyzing event-related brain potentials (ERPs) from a language processing experiment in German as a representative application. In this paradigm, the averaged ERPs exhibit an N400 followed by a sentence final negativity. Contemporary sentence processing models predict a late positivity (P600) as well. We show that the SRA is able to unveil the P600 evoked by the critical stimuli as a weakly dominant mode from the covering sentence final negativity.

  19. Power coupling mode transitions induced by tailored voltage waveforms in capacitive oxygen discharges

    Science.gov (United States)

    Derzsi, Aranka; Bruneau, Bastien; Gibson, Andrew Robert; Johnson, Erik; O’Connell, Deborah; Gans, Timo; Booth, Jean-Paul; Donkó, Zoltán

    2017-03-01

    Low-pressure capacitively coupled radio frequency discharges operated in O2 and driven by tailored voltage waveforms are investigated experimentally and by means of kinetic simulations. Pulse-type (peaks/valleys) and sawtooth-type voltage waveforms that consist of up to four consecutive harmonics of the fundamental frequency are used to study the amplitude asymmetry effect as well as the slope asymmetry effect at different fundamental frequencies (5, 10, and 15 MHz) and at different pressures (50–700 mTorr). Values of the DC self-bias determined experimentally and spatio-temporal excitation rates derived from phase resolved optical emission spectroscopy measurements are compared with particle-in-cell/Monte Carlo collisions simulations. The spatio-temporal distributions of the excitation rate obtained from experiments are well reproduced by the simulations. Transitions of the discharge electron heating mode from the drift-ambipolar mode to the α-mode are induced by changing the number of consecutive harmonics included in the driving voltage waveform or by changing the gas pressure. Changing the number of harmonics in the waveform has a strong effect on the electronegativity of the discharge, on the generation of the DC self-bias and on the control of ion properties at the electrodes, both for pulse-type, as well as sawtooth-type driving voltage waveforms The effect of the surface quenching rate of oxygen singlet delta metastable molecules on the spatio-temporal excitation patterns is also investigated.

  20. Using Brillouin fiber-optic ring laser to provide base station with uplink optical carrier in a 10 GHz radio over fiber system

    Institute of Scientific and Technical Information of China (English)

    CHEN Hao-shuo; LIN Ru-jian; YE Jia-jun

    2009-01-01

    In this paper, a 10 GHz radio over fiber system is analyzed. The Brillouin fiber-optic ring laser is used in the center station (CS) to suppress the optical carrier for the modulation depth enhancement. Simultaneously, the Stockes waveinduced by the Brillouin amplification injects and locks the Fabry-Perot (FP) laser to output a signal-mode optical source,which works as the uplink optical carrier.